Classification of Pesticides Based on Origin and Pest Control

September 25, 2012, 10:24 pm

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Pesticide is a chemical or biological substance that is intended to prevent or repel or destroy the pests that may damage or disturb the growth or health of living organisms which may be plants or animals. These pests include insects, rodents, fungi, weeds, nematodes, algae, etc.

These pesticides are classified on the basis their origin or structure or pests they control or the mode/ site of action.

Classification based on their origin-
There are two types – chemical pesticides and bio pesticides.

Chemical pesticides are further divided into four types based on their origin -

Organophosphate pesticides - These are the chemical substances which are produced due to reaction between phosphoric acid and alcohols. This affects the nervous system by inhibiting the action of enzyme acetyl cholinesterase (AChE). This causes irreversible blockage leading to accumulation of the enzyme which results in overstimulation of muscles. These mainly include insecticides, nerve gases, herbicides, etc.

Carbamate - These are esters of carbamic acids. The mode of action is inhibiting acetyl cholinesterase similar to that of the organophosphates but the bond formed for inhibition is less durable and thus reversible. These also include mainly of insecticides.

Organ chlorine pesticides- These are the derived from chlorinated hydrocarbons. These are endocrine disrupting agents which effect on the hormonal systems of the body, act as duplicates of the normal hormones and thus causing adverse health problems. They remain in environment for a long time by breaking down slowly and accumulating in the fat tissues of animals. A well-known example is DDT (dichloro diphenyl trichloroethane).

Pyrethroid pesticides- These are potent nuero poisons, endocrine disruptors and cause paralysis. Pyrethroids are synthetic version of pyrethrin a natural insecticide. They have similar chemical structure and similar mode of action as of pyrethrin which is obtained from chrysanthemum. These are derivatives of ketoalcoholic esters of chrysanthemic and pyrethroic acids and are more stable in sunlight than pyrethrins. These are most popular insecticides as they can easily pass through the exoskeleton of the insect. Few examples are- deltamethrin, cypermethrin, etc.

Biopesticides:
These are naturally occurring materials or derived naturally from living organisms or their metabolites, like bacteria, fungi, plants, etc. These are classified into three major groups-

Microbial pesticides- This has microorganisms acting as pest controllers like bacteria, fungi or viruses. Each of it contains specific target. Widely used are strains of Bacillus Thuringenesis or Bt and its subspecies. The mode of action generally is producing a protein that binds to the larval gut receptor which starves the larvae.

Biochemical pesticides- They are naturally occurring, nontoxic pest controllers. These include pheromones, natural plant and insect regulators, enzymes, bio repellents or attractants.

Plant incorporated protectants (PIPs) - These substances are produced by plants naturally but the gene necessary for production of pesticide is introduced into the plant through genetic engineering. The substance produced by the plant and the genetic material introduced are together defined as plant incorporated protectants (PIPs).

Classification based on their pests they control-

Insecticides- These act especially on insects.
Algaecides- control or kill growth of algae.
Herbicides – controls or kills weeds.
Bactericides - acts against bacteria.
Fungicides- acts against fungi.
Rodenticides- kills or prevents rodents i.e. rats or mice.
Larvicides – inhibits growth of larvae.
Repellents – they tend to repel pests by its taste or smell.
Desiccants- they act on plants by drying their tissues.
Ovicides – they inhibits the growth of eggs of insects and mites.
Virucides- acts against viruses.
Molluscicides – they inhibit or kill mollusc’s i. e snail’s usually disturbing growth of plants or crops.
Acaricides – they kill arachnids like mites.
Nematicides – they are tend to kill nematodes that act as parasites of plants.
Avicides – these are used to kill birds.
Moth balls- these are used to stop any damage to cloths by moth larvae or molds.
Lampricides – these are designed to target larvae of lampreys which are jawless fish like vertebrates in the river.
Piscicides – they are substances that act against fishes.

Though pesticides are designed to kill or inhibit organisms that cause damage to the crops or animals, they have harmful effects on other organisms that must not be effected and tend to pollute the environment. If used in high quantities they can be lethal sometimes. Biopesticides are used instead of chemical pesticides as the negative effects are low compared to chemical pesticides.

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Genetic Engineering - An Easy Explanation

September 26, 2012, 3:11 am

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Modern human (Homo sapiens) are present on the Earth for around 200,000 years. We weren't the only hominids on the planet, but we were certainly the cleverest ones. One organ played a vital role in our successful adaptation to a hostile environment – it was a human brain. Thanks to the brain, we were able to create all kind of tools that could simplify our everyday life and facilitate battle for food and warm shelter. It all began with various weapons, followed with the discovery of fire, wheel, electricity….and now, even though we are living in a relatively safe and controlled environment, modern technology is progressing to the aspects of life we couldn't imagine 100 years ago and it’s not just omnipresent but it’s necessary.

Being curious by nature, throughout the centuries we discovered how different organisms are built, how they are working, what triggers the illness and how we can hill ourselves and/or other creatures, what are the basics of reproduction…. Today, we are combining all that knowledge with modern technology to change who we are.

Genetic engineering is one of the most investigated scientific fields with endless possibilities. Fact that all living creatures are built and are functioning thanks to the information written in their DNA (or RNA when it comes to some viruses) is what makes genetic engineering that popular. Deoxyribonucleic acid (DNA) is a main constituent of the chromosomes; it contains genetic information and ability to replicate when cell is dividing. Genes are sequences of DNA, hereditary units specifically located on chromosomes, present in two copies (one copy from each of our parents) that will determine our individual characteristic after expressing. Genome is a set of all known genes within the species. What makes us so different from each other is actually a minimal redistribution of DNA nucleotides that makes us unique and unrepeatable. 99,9% of human genome is universal to all people and just 0,10% differences in our DNA will lead to distinctive characteristics each person have. We are not that different from other species as well - most biochemical processes inside living organisms are universal or at least similar. That simple fact triggered first genetic experiments, and once they started – there was no way back.

Genes are in charge for much more than just the color of our eyes. Few enzymes and couple of RNA molecules are most important participants in the complicated and jet fascinating machinery that is controlling genetic expression. Final product of genetic expression is protein. Proteins are essential for all the biochemical processes inside the organism. Most of those processes can be described as cascade where one molecule affects other and it’s a chain reaction leading at the end to a normal breading, hormone production, neurotransmitters release – in one word – having one normal and functional organism. If gene undergoes unwanted mutation and become dysfunctional – complete process will be affected and disease will develop. That’s where genetic engineering is more than useful. For example, insulin is polypeptide essential for sugar and fat metabolism. Without insulin blood sugar level can’t be regulated and result is diabetes. People with diabetes need insulin in regular daily doses but since insulin is natural protein – its production isn’t that simple. Solution comes with recombinant DNA technique. Bacterial cells contain single DNA and one or more plasmids (a circular and chromosomally independent DNA chain inside the cell) that could incorporate foreign genes and start producing the protein we want during the genetic expression phase that is happening normally in the bacterial cell. Since the genes from different species share same chemical structure, we can easily slice plasmid’s DNA at certain spot and incorporate gene that we need to multiply using specific enzymes and create expanded DNA chain that will produce one more protein in the next genetic expression round. This technique is used for multiplying a lot of proteins where most popular examples are production of the growth hormone, clothing factor VIII, recombinant hepatitis B vaccine….

Beside bacteria, plants can also be enriched with couple of foreign genes that could either enhance their endurance and tolerance toward pests and environmental conditions or increase vitamin/protein amount…

Not all genetic engineering experiments turned to be successful and useful for human kind. As with all other experiments, finding the right balance is always the key to success, but as I mention before with genetic engineering – possibilities are endless.

Lysosomal Storage Disorder and its Treatment

September 26, 2012, 6:57 am

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Lysosomal storage disorder (LSD), the very rare inherited disorder is a condition due to lysosomal dysfunction of the cell. Lysosome, the organelle of a body cell, acts as the recycling centre of the cell by breaking down the waste substances (substrates) generated in the cell into useful product which in turn is utilized by the cell. Also, any foreign body entering the cell is evaded by lysosome. Lysosome also digests dead cells and thus its role in short can be explained as cellular substrate management and cellular digestion.

The history of Lysosomal storage disorder dates back to 1880’s even before the discovery of lysosome in 1960s. About 40 different hydrolytic enzymes (proteins) are essential for proper functioning of the lysosome. Each of these enzymes is responsible for reduction of particular substrate and deficit or absence of any of these enzymes result in substrate accumulation in the cell causing various diseases categorized under LSD. To name a few, they are Tay-Sachs disease, Gaucher disease, pompe disease, Niemann-pick disease, Farber disease, Krabbe disease, Sandhoff disease, Schindller disease, salla disease and Wolman disease. The most affected age group is children, once inherited the disease, they die even before 15 years of age. Various researches on LSD have proved the average ratio of prevalence of this disorder is 1 in 5000 live births.

The various signs and symptoms of LSD depend on the type of enzyme deficient and the particular type of cell (liver cell, brain cell and so on) which is affected due to Lysosomal dysfunction. Some of the symptoms are reduced motor skills, growth retardation, enlarged organs and rare facial features. Based on the symptoms, the adversity of the disorder is diagnosed by various techniques like enzyme assay and mutation analysis.

In enzyme assay technique, the enzyme levels in patients with LSD are assessed and compared to the desirable level. This technique is even applicable to testing fetus suspected to have inherited LSD, where the sample is collected through amniocentesis. Whereas mutation analysis is carried out for patients suspected to have inherited the disease from carriers in their family.

Treating LSD patient is a challenging task due to restriction in treatment methods and also the symptoms of LSD have adverse effects on overall body system. Most of the LSD patients are treated by managing symptoms. The few treatment methods available for specific Lysosomal storage disorder are Bone marrow transplantation, enzyme replacement therapy, substrate reduction therapy, Umbilical cord blood transplant, Gene therapy and chaperone therapy.

Bone marrow transplant involves transplanting stem cells from a healthy donor to the patient to stimulate the production of the deficient enzyme. In enzyme replacement therapy, the genetically engineered copy of the deficient enzyme is given to the patient intravenously. The rate of production of substrate responsible for the disorder is slowed by administering drugs in substrate reduction therapy. Though these methods prove to be considered treatment methods for LSD each of it has its own limitations which led to the development of research in the field of various treatment methods.

As a result the developed methods are enzyme enhancement therapy, substrate synthesis inhibition therapy, gene therapy and chaperone therapy. In enzyme enhancement therapy, the defective enzymes in LSD are stabilized and in substrate synthesis inhibition therapy applies the principle of blocking a step in substrate production thus reducing the accumulation. Gene therapy, as the name indicates the normal copy of gene replaces the mutated gene responsible for deficit enzyme, thus inducing the normal production and function of the enzyme.

Inspite of the availability of various treatment methods and diverse research to derive suitable treatment methods, the success of it depends on the condition of the patient. While treating a patient for LSD, all the other ailments, past history etc has to be taken into consideration. A complete clinical history of the patient has to be maintained and it also involves care from multidisciplinaries to treat a patient for Lysosomal storage disorder because of its complexity.

Thus the cause, symptom, diagnosis and available treatment methods for LSD is discussed. All the available treatment methods are costly and hence the earlier the diagnosis of the disease increases the maximum chances of survival from the available treatment methods. The knowledge on LSD is significant for individual and medical specialist to diagnose the disease early and treat it.

Nanotechnology Applications in Medical Science

September 27, 2012, 2:49 am

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Nanotechnology has become a vastly explored area of research in the present times mainly in the biomedical research. Nanoparticles have found importance in the drug delivery, disease diagnosis, as well as therapeutic applications. Nanotechnology deals with the particles having length in the nanometer scales i.e one billionth of a meter. At such small sizes, the particles have high ratio of size to volume, which influences their reactivity and their properties as a whole changes from that of their native element.

In the biological system, drug delivery to the target system or organ has become a major issue. For instance, drug delivery through the BBB is a tough challenge. Though many drugs have proved effective potent drugs for the CNS, but due to improper drug delivery system through the BBB to the brain, successful treatment of brain-related diseases has not made much progress. It is here that nanotechnology has made a mark because of its size, surface functionalization, and other factors.

Many varieties of nanoparticles are available which have created impact in different ways such as nanotubes, liposomes, polymer of nanoparticles, dendrimer, quantum dots, micelles, etc. Nanotubes are carbon rods with diameter half as that of a DNA molecule. They are studied extensively for successful gene delivery, as well as delivering plasmid DNA, proteins, synthetic enzymes, etc. into the living system. A number of vectors like fungi, bacteria are available for gene delivery into the cells but many factors like toxicity, biodegradability, evoking immune response, etc while using those vectors have opened research in this field. Hence, nanotubes have gained much importance in this area. The nanotubes are hollow tubes with either both sides open or one side closed with a cap made of nanoparticles known as nanocap. The bioactive agent is attached to the nanotubes and then it is delivered to the target cell in the animal body or the target site in the plant by different routes such as intra-dermal, intravenous, trans-mucosal sites, etc., within the body (human or animal) or by application on the plants mechanically. The nanotubes are made with biodegradable material, which degrades after reaching the target site with time thereby releasing the bioactive agent within the body. The biodegradable material with which the nanotubes are made, are carefully selected such that it helps in the proper delivery of the bioactive agent to the target site and the nanotubes are degraded only after reaching the site of action thus releasing the bioactive agent. The nanotubes have also found application in the detection of mutations within the DNA whereby the mutated regions of the DNA are tagged using bulky molecule with tags specific for the mutated sequence. The needle-like tip of the nanotubes is then used to trace the mutated DNA, which has been tagged, and to identify alteration in the shape of the specific DNA. Thus, nanotubes play a very important part in detecting different diseases like cancer and this uniqueness of the nanotubes have made them have different applications in various fields of research like biomedicine, agriculture, industry, environmental science, etc.

Gold nanoparticles (GNPs) or Colloidal Gold has been widely used as drug delivery agents and in targeting of cancer cells due to their minimal reactivity within the biological system. Colloidal gold refers to the suspension of the nanoparticles in fluid, mainly water. Colloidal gold has been proved effective in the treatment of Rheumatoid arthritis and in the destruction of the beta amyloid plaques in the Alzheimer’s disease. Detection of the tumors in-vivo has been possible due to the GNPs with the help of SERS, Surface Enhanced Raman Spectroscopy. Other radiative applications of the colloidal gold are yet to be explored. The GNPs have also been used in many sensitive assays for diagnosis, radiotherapy, etc.

Two other nanotechnological products: Quantum dots and Nanoshells are used in diagnosis and therapy of cancer respectively. The quantum dots glow under UV light stimulation. Hence, specifically designed quantum dots can be used that bind to mutated DNA and the site of this mutated DNA can be identified in-vivo when the bound quantum dots glow under the stimulation of UV light, thus exposing the regions of localisation of mutated DNA specific for causing cancer. The nanoshells have the property of absorbing near-infrared light resulting in heat resulting in cell death. The nanoshells can be made to reach the tumor region by linking them with antibodies specific to the tumor cells and destroy the cancer cells, without affecting the neighbouring cells. Thus, nanotechnology has made great advancement in medical science.

Importance of Drug Metabolism in Drug Discovery

September 27, 2012, 2:57 am

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In drug discovery process, drug metabolism plays a major role and determines the fate of the prospective drugs. Drug metabolism must take place only after the drugs reach their specific target site and produce the desired effects. In addition, the nature of the metabolites produced from the drug, must be thoroughly studied; otherwise, the drugs would be rejected during the screening process. Hence, drug metabolism is a major criterion in the high-throughput screening of prospective drugs.

Drug metabolism mainly takes place in the liver, where along with metabolism of the drugs, the excretion and thus the clearance of the drugs takes place. Drug metabolism mainly takes place in two phases – Phase I and Phase II. The Phase I reactions mainly result in functionalization of the drugs whereas the Phase II reactions result in the increased polarity of the drugs due to the conjugation of a polar group on the drug, thereby increasing their solubility which helps in their excretion from the body. The Phase I reactions mainly involve the action of Cytochrome P450 enzymes, Flavin Monoxygenases, etc, while the Phase II reactions mainly involve the action of UDP glucuronyl transferases (UGTs, sulfotransferases, etc.).

The Cytochrome P450s play a very important role in drug metabolism as they help in the addition or unmasking of functional groups so that the Phase II enzymes act upon them. Cytochrome P450s are heme- containing isoenzymes present in the lipid bilayer of the endoplasmic reticulum of the hepatocytes. Since, they have a colored pigment, which absorbs light of wavelength 450nm, hence the name. Many isoenzymes of cytochrome P450s are expressed within the human body, which act upon different substrates, and of them, some play important roles in drug metabolism. The main metabolic reaction that takes place is the mixed oxidation function whereby the drug undergoes oxidation reaction with the formation of NADP in the reaction. The metabolic studies of the prospective drugs is carried out using in-vitro models like: a) microsomes (human, rat, mouse, etc) derived from the SER (Smooth Endoplasmic reticulum) of the cells; b) S9 fraction obtained from the differential centrifugation of the liver homogenate; c) fresh and cryo preserved hepatocytes; d) tissue slices; e) recombinant expressed enzymes. During the metabolic studies, cytochrome P450s have been extensively studied as Phase I reactions are greatly affected during co-administration of more than one drug. This phenomenon is known as drug – drug interaction. In the co-administration of more than one drug, either inhibition or induction of the cytochrome P450s takes place due to which the metabolism of the drugs is affected. When the metabolism of the drugs is affected, it hinders the proper action of the drugs as the drugs are either easily eliminated from the body due to faster metabolism or they remain in the cells for longer period due to inhibited metabolism producing toxic effects. Hence, drug-drug interaction study has become a part of the metabolic stability study of a prospective drug.

Drug metabolism has an important role in the determination of the pharmacokinetic (PK) parameters like oral bioavailability, clearance and the half-life of the entity within the cell. The drug metabolic studies help to screen the compounds based on their metabolic rate and thereby help to proceed with the in-vivo studies using rat, mouse, etc. The determination of the metabolite structure with the help of LC/MS-MS and the metabolic phenotyping i.e. the particular enzyme responsible for the metabolism of the prospective drug, which can be done using recombinant enzymes, gives a much clearer idea about the metabolism of the compounds and the information derived can be used for further drug-drug interaction studies. However, the metabolic phenotyping of a prospective drug is quite difficult, long-drawn and expensive process. High-throughput screening of the prospective drugs based on their metabolic stability is carried out mainly using liver microsomes in a drug research lab.

Drug metabolism is very essential in the toxicity studies too. The persistence of the compounds in the systemic circulation for long period causes toxicity and the nature of the metabolites and the reaction of the metabolites within the body, must be studied thoroughly before the compounds progress to the next stage of screening in drug discovery process. In this way, it is seen that drug metabolic studies form an integral part in drug discovery.

Surface Functionalization of Nanoparticles in Drug Delivery

September 27, 2012, 4:13 am

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Nanotechnology has opened up a new area of research for the disease diagnosis as well as therapeutics. Though drug discovery is very essential for the proper treatment of the diseases, drug delivery remains a major concern. The agents used for drug delivery have been found to possess their own properties of cell toxicity, low persistence in the microenvironment of the body as well as impermeability across the cell membranes, which result in inefficient drug delivery within the body. Nanoparticles have emerged, as a better alternative for drug delivery in recent times though further in-depth research is essential to provide concrete evidence for the same.

Nanoparticles are usually made of elements, which are biologically less reactive and hence used for different diagnostic assays as well as therapies. The nanoparticles due to their extreme small size, zeta potential and other favourable factors have added advantage in being used as drug delivery agents. Adsorption of the proteins like antibodies or other bioactive moieties on the surface of the nanoparticles is a method by which the bioactive agents are transported to the target site in-vivo, but this method has some disadvantages because of which surface functionalization has gained importance. The adsorption on the surface technique causes the denaturation of the protein adsorbed in most of the cases and the presence of steric hindrance is one more drawback. Moreover, the nanoparticles must have to be present in the systemic circulation for a longer period. All these factors have initialized the study of surface functionalization of nanoparticles, which has become a greatly researched topic.

Surface functionalization means the introduction of chemical functional groups on the surface of the nanoparticles. The chemical groups are not directly attached to the nanoparticles but are attached using spacer arms or other lipophilic agents. Many studies have been conducted whereby PEG (Polyethylene glycol) has been used for the surface functionalization of the nanoparticles. The surface functionalized nanoparticles become capable of crossing the lipid bio layer of the membranes of the cell and thereby help in the delivery of the drugs and other bioactive agents to the target site in-vivo. The PEG spacer allows the GNPs (Gold nanoparticles) to persist in the systemic circulation within the body protected from the macrophage attack while providing flexibility also to the molecule for proper interaction with the target. Research with other surfactants apart from PEG, which can provide the same advantages as PEG in the drug delivery through nanoparticles is going on.

Surface functionalization is possible for carbon nanotubes (CNTs) also apart from GNPs. The CNTs have two ends and two surfaces (inner and outer). Hence, it provides wide possibility for functionalization on its surface thereby providing a possibility of delivery of bioactive agents within the body. The functionalization of the CNTs occurs usually by the physical adsorption of the surfactants by weakening of the van der Waals interaction within the bundle of CNTs, which may lead to the exfoliation of the CNTs. The exact mechanism of the adsorption and the nature of interaction between the CNTs and the surfactant remain unknown, though, it is suggested that in some cases the polymer coils itself around the CNTs in a helical fashion.

The surface functionalization of the nanoparticles has made tremendous progress in drug delivery through BBB. The potential drugs used for the therapy of the CNS related diseases face an enormous challenge of crossing the BBB due to which much progress in the successful treatment of the CNS related diseases has not been made. This problem has been resolved largely with the use of functionalized nanoparticles. Many possible mechanisms have been reported for the delivery of the drugs through the BBB with the use of nanoparticles. Endocytosis or transcytosis of the endothelial cell layer, dissolution of the membrane lipids of BBB due to surfactant effect, loosening of tight junctions of BBB due to the nanoparticle effect or the modification of the efflux protein in BBB thereby preventing efflux , may be some of the mechanisms by which the drug-coated nanoparticles move across BBB. Many other mechanisms have been suggested, which need proper concrete evidence as proof for the same. In this way, it is seen that surface functionalization of the nanoparticles has broadened the research related to drug delivery.

Biotechnology in Food Processing Industry

September 27, 2012, 5:12 am

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Biotechnology has played a diverse role in the application of science in different spheres of life. Gene transfer, Recombinant DNA technology, development of vaccines including DNA-vaccines, development of hybrid plants, genetic modifications, etc are some of the areas where biotechnology has played a major role. Biotechnology also has an important role in food processing whereby it helps in targeting the microorganisms in the bio-processed foods thereby improving the quality and safety regarding the consumption of such products.

Food processing is a process by which non-palatable and easily perishable raw materials are converted to edible and potable foods and beverages, which have a longer shelf life. The method, by which the microbial organisms and their derivatives are used to increase the edibility and the shelf life of foods, is known as fermentation. Almost one-third of the diet in the whole world consists of fermented food. Hence the process of fermentation must be carefully monitored especially in rural areas as improper method of fermentation may cause contamination of food thereby, affecting the health of the people. Fermentation is also used in preparing microbial cultures, food additives, preservatives, etc.

Biotechnology has a major application in the food sector. It helps in improving the edibility, texture, and storage of the food; in preventing the attack of the food, mainly dairy, by the virus like bacteriophage; producing antimicrobial effect to destroy the unwanted microorganisms in food that cause toxicity; to prevent the formation of mycotoxins; and degradation of other toxins and anti-nutritional elements present naturally in food. The advance in application of biotechnology in food processing mainly concerns with the traditional approach of improving the strains of microorganisms and development of further improved micro-organic derivatives like enzymes, etc. Before application of various techniques, the characterization of the genetics of the microorganisms is very essential as it gives a clear idea about the favourable and non-favourable factors that affect the growth of the microorganisms. Improved strains of microorganisms can be produced by a variety of techniques like genetic modification by mutagenesis by exposure to various chemicals, gene transfer mediated conjugation by using plasmid DNA, or by genetic recombination by hybridisation with better yielding microorganism (E.g. Yeast). Recombinant DNA technology also plays an important role in modification of the genetics of the microorganisms favourably by accelerating the expression of favourable genes and hindering that of non-favourable ones by the introduction of plasmid vectors, which are food grade. In all the cases, genomic study of the microorganisms related to food is essential as it acts as a guide in identifying the metabolic process as well as the genetic mechanisms. From this, the genes responsible for the production of favourable enzymes and sugars for fermentation are identified and the application of proteomics for the identification of the proteins responsible and the interactions between proteins for the improved fermentation process is possible.

Biotechnology also plays a very important role in protein engineering. In this, favourable enzymes of the microorganisms, which are responsible for the improved fermentation, are produced commercially at a large scale by culturing the microorganisms in tanks, etc. From the industrial culture of the bacteria, the enzymes produced as metabolites can be isolated and used in food industry. This production of enzymes at such large scale makes the availability of the enzymes at reduced cost with good quality possible. Moreover, modified enzymes with improved efficiency have also been made possible by the genetic modification of the microorganisms. These modified enzymes have better thermo stability as well as novel protein structure that make them more desirable having activity on different pHs other than the usual pH of the enzyme as well as act on different substrates.

Various amino acids, food-flavouring agents, food additives, and preservatives are all different derivatives obtained from different microorganisms. Biotechnology helps in understanding the metabolic pathways of the microorganisms thereby helping in isolating the required derivatives. The technology also helps in the identification of the pathogens, pesticides, as well as anti-nutritional factors present in the food. It helps identifying various contaminants like mycotoxins, which cause decrease in shelf life of the foods as well as cause toxicity of foods, by different tests like ELISA, microarray, etc. Although, Biotechnology plays a very important role in the food processing industry, much advance has not been made in this area mainly in developing countries due to socio-economic factors of the population. Research in this area is possible only if the government of the developing countries gives support and makes improvement in the development policies regarding the food sector.

Bioplastic - As Green as Possible!

September 27, 2012, 6:12 am

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Modern society is growing exponentially. Wave of industrialization at the beginning of the 19th century accelerated the life style. That period is most famous for a rapid development of a numerous machines that speeded up production of consumer goods and brought us couple of new materials that were fast to produce, ease to use and applicable in so many aspects of our life. Plastic (beside the rubber developed at the same time) and all kind of items made of plastic soon became inevitable and very important part of our lifestyle.

Parkesine is the first known plastic patented by Alexander Parks in 1856th year. It consisted of cellulose treated with nitric acid. The obtained material was not particularly strong and didn't last for a long period of time, but it paved a path for further plastic development. First synthetic plastic called bakelite emerged in the early 20th century when Baekeland start experimenting with phenol and formaldehyde. He mixed them and ended up with non-conductive and heat resistant material that served perfectly as electric insulator. Even thought at the beginning plastic was made out of natural materials its future development was more focused on synthetic polymers where polystyrene, polyvinyl, nylon...were the most famous ones. Today’s plastic is made out of fossil fuels (petroleum) almost exclusively.

Bags, containers of different size and shape, bottles, phones, remote controls, handles on refrigerators, garbage cans, watering cans, light switches, chairs.... plastic is all over the place! Manufacturing process is relatively simple and inexpensive and plastic is available everywhere on the planet to be used for numerous purposes. But plastic has a dark side. Huge amount of CO2 is released during production of plastic which directly increases greenhouse effect and plastic waste contribute greatly to the overall pollution of the planet. Plastic can’t be degraded by microorganisms as it is artificial material and microorganisms don’t have enzymes necessary to digest it. Roughly estimated, lifespan of the plastic bag is between 500 and 1000 years. I have read somewhere that Chinese people spend three billion plastic bags a day! I bet that 2.9 billion end up in the nature.

Bags and other items made of plastic are considered one of the biggest natural pollutants and besides "decorating" plants in cities they can be fatal to wildlife. Birds can easily tangle their beaks or wings in a plastic bag; sea animals could swallow plastic waste because they could easily mix it with something that is normally found in their environment.... Sad story of that kind are endless.

Modern society are trying to solve the problem of excess plastic waste by sorting and recycling it, by stimulating eco-consciousness in humans and by penalties for improper disposal of garbage ...

What truly can solve the problem and save the planet is creation of biodegradable plastics.

Unlike "classic plastic", biodegradable plastics are made of natural materials: corn starch, pea starch, vegetable oil... Like conventional plastics, biodegradable plastic have very diverse applications: it’s used for packaging (various types of food and drink containers), for insulation, medical implants (that will be broken down within the body after a while), for compostable mulch films that protect crops from weeds and conserve moisture (there’s no need to collected them later since they are biodegradable and will break down on their own after a while)… Most biodegradable plastic items are disposable instead to be used multiple times.

50% of biodegradable plastics in the world are made out of starch. The addition of sorbitol and glycerin are providing typical "plastic" structure. Remaining 50% of bioplastics are generated by treating cellulose, or our of polylactic acid (cane sugar and glucose are starting points in this technology), out of poly-3-hydroxybutyrate (after treating sugar, starch, waste water with certain kind of bacteria), polyhydroxyalkanoates (using bacteria that ferment sugar and fat)....

Although today's bioplastics manufacturing techniques are expensive, demand for that particular type of plastic and its widespread use will inevitably reduce their price. We should start working on our eco awareness and we should reduce unnecessary plastic consumption to a minimum. Looking in the long term, that way we could improve the health of our planet along with its inhabitant. We should all go green as much as possible!

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USA: Looking for partnerships in Immunology, Inflammation and Neurology?

September 27, 2012, 2:17 pm

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If so, we are organizing a B2B business event and bring in California a delegation of French Innovative Biotech companies.

Called the "French Biotech Tour", the event will be held on Oct16th in San Francisco & on Oct18th in San Diego

If you are a company or an academic and you want to explore new partnerships, feel free to contact me !


To have an idea of What is a French Biotech Tour, check this video: http://www.youtube.com/watch?v=2vojPBiNI...ature=plcp

Need Biotech Business Idea

September 27, 2012, 5:26 pm

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I need to come up with an idea for a biotech product or service that I can turn into a business for my college course. Finding it very hard to come up with a novel workable idea without ripping someone off. Came up with ideas like home bioreacter for turning food waste into methane, a protein water, an insulin reader thing, I dunno. Any simple ideas would be greatly appreciated

Bio-Artificial Liver in the treatment of Acute Liver Failure

September 28, 2012, 12:45 am

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Liver is a multitasking organ in the body being able to synthesise several plasma proteins, immune factors as well as several metabolising enzymes and factors helping in digestion and excretion within the body. Hence, on liver failure several severe complications are noticed in the body affecting several other organs like kidney, brain, and even causing ultimate death. Although, liver transplantation remains the ultimate solution in case of Acute Liver Failure (ALF) but due to shortage in the availability of donors, other methods to support the liver functions are being devised. Doctors have made progress in the replacement of the different damaged organs within the body with artificial devices when transplantation becomes an issue due to unavailability of the donors or organs. In case of ALF also, Artificial Liver Support Devices (ALSDs) have been developed, which provide a temporary solution between the ALF and liver transplantation or liver regeneration from the donor liver hepatocytes, which have the capacity to regenerate the whole liver and restore its function by continuous proliferation.

ALSDs are based on the idea of removal of toxic substances from the blood. These may be of two types: Non-Biological LSDs and Biological LSDs. The Non-biological LSDs mainly remove the excretory wastes from the body based on the dialysis and filtration principle. It was found that they provide temporary solution and are not much efficient as they are unable to restore other important functions of liver because of which the patients could not survive for long. This led to the idea of development of LSDs, which are biological in nature and could provide long-lasting solution for the survival of the ALF patients. The synthetic, metabolic as well as excretion functions of the liver are being restored largely by the biological LSDs, hence research on bio artificial liver devices is making progress.

The Bio artificial livers are support devices connected to the patients’ plasma circulation outside the body. They are liver cells charged bioreactors, which help in restoring almost all the main functions of the liver. The bioreactors mainly consist of porcine or human hepatocytes, which are parenchymal in nature. However, for the optimum function of the bioreactors, they must contain mixed differentiated cells whereby the liver cells possess 3D configuration. The bioreactors are of four types: hollow fiber types; suspension or encapsulation; monolayer and scaffolds. The bioreactors are mainly used for the improvement in the cell oxygenation as well as mass- exchange. In most of the cases, it is seen that the bioreactors do not consist of the biliary system, which aids in the excretion of conjugated bilirubin. Hence, for proper excretion of this bilirubin, an artificial mode is attached to the bioreactors, which help in the removal of this bilirubin, thereby preventing toxicity.

The bio artificial livers consist mainly of the freshly isolated or cryopreserved porcine hepatocytes as they are easily available. Though, they may provide reliable data regarding the restoration of function of the liver function due to similar biologic properties like human hepatocytes, but there are a number of disadvantages regarding their use. The xenozoonosis i.e xeno transplantation effect due to using cells of different species causes unreliability in the data observed by using porcine hepatocytes in the bioreactors. The transmission of the pathogens like porcine retrovirus also is another added disadvantage in their use. Hence, freshly isolated human hepatocytes must be used as cryopreservation of the same causes the loss of the enzyme function largely. The research carried out using human-origin hepatocytes provides reliable data regarding the advantages in using bioreactors in the treatment of ALF. Immortal hepatocytes developed from hepatoblastoma cell line or other tumor cells have also been developed for the study of bioreactors, though the possible toxicity resulting from using such cells cannot be ignored. Hepatocytes have also been developed from the tissues slices of the discarded donor livers, though their availability at the required time cannot be guaranteed.

The clinical proofs regarding the use of bio artificial livers are not much favourable in the present scenario. The hepatocytes used in the bioreactors may not always be completely differentiated ensuring proper function nor are they always present in 3D conformation. Moreover, the patients used for clinical trials are diverse in nature; hence, the resulting statistical data may not provide concrete positive result. The bioartificial livers may provide bridge in the treatment of the patients until the availability of the liver to be transplanted, but the lasting effect of the use of bioartificial livers on the patients after transplantation has not yet been proved completely. The clinical trials with the human hepatocytes are going on and much research is needed before the bio artificial livers can be successfully used in the treatment of the ALF patients.

Toxicity Predictive in Silico Tools

September 28, 2012, 2:44 am

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Whenever we get sick we are instinctively swallowing various pills in order to help our organism win the battle with microorganisms that are disturbing our normal functioning or to soothe inner biochemical reactions that are responsible for the pain we are feeling. Traditional healing using the herbs is probably as old as mankind is, but discovery of penicillin and synthetic compounds (that could accelerate healing process or help regenerate our vital functions) started an avalanche in pharmaceutical industry.

Every drug that ends up on the shelf in the pharmacy is taking a long way to get there. Drug development and following safety assessment phases are lasting between 10 and 15 years and whole process is very expensive (roughly estimated: > billion dollars). First, potential molecule needs to be selected and chemically approved as one that has specific type of activity that will reduce or completely diminish biological process responsible for illness. Animal safety comes next. Time is important factor in this phase as adverse affects can be reflected in the offspring also. Finally, after years of testing on various animals, drug is entering clinical phases. Healthy volunteers are used in the first phase where doctors are monitoring drug’s effects on the healthy organism. Healing effects of the drug are tested on a small group of a sick people in the phase 2, followed by the tests on a bigger group of sick individuals in the phase 3 where statistically significant data will be gathered and final judgment on drug’s pluses and minuses will be given. Thousands of molecules are thrown away after just a couple of experiments at the beginning of the drug discovery process. Couple potential compounds are entering preclinical study stage where their safety, toxicity, pharmacokinetics… will be tested. In vitro experiments with cultivated cells derived from different organs or organisms are used during certain experimental phases, but most experiments are focused and held on live animals (mice, rats, dogs, chimpanzees…) called in vivo experiments. In vivo tests are causing a lot of suffering to the animals considering that numerous experiments are taking place all over the globe and the high number of the (often aggressive) chemicals are applying at the highest dose in order to check all kinds of adverse effects. Sad but true: every marketed drug is stamped with a blood of a large number of innocent animals. Most people said that we shouldn’t care or be concerned for experimental animals as they are sacrificed for human’s well-being. I couldn’t agree less! Luckily, good news for all animals and animal lovers are just around the corner. According to the latest medical laws, number of animal experiments will be restricted in the near future and replaced with computerized simulations.

Main characteristic of each drug (besides being relatively safe for consumer’s health) is that it can “locate” and “combat” altered biological process that is triggering the illness. Biochemistry of the biological processes inside of our bodies is well known to the scientists. If you can recognize the pathology – you’ll be able to find the solution (destroying cancer cells by affecting tumor vasculogenesis, for example). Chemical properties of either natural or synthetic compounds are tightly related to their structures. Whenever you have two compounds with similar structures – you can count on the similarity in their “chemical behavior”. One can be less toxic or metabolized easier than the other and those small but important differences can be crucial during drug development process. In silico (computer based) methods are very handy, helpful and cost & time reductive options that are often used both for chemical analysis as well as for toxicity prediction. Basically, those are specifically designed software that are using integrated algorithms to compare chemical structure of the compound of interest with the compound that is well known, well explored and already in the system. Higher similarity – higher possibility to express similar behavior within organism (possible side effects, effectiveness against illness…).

Industry of in silico tool is growing and developing rapidly. By using some of those tools drug development process could be accelerated for sure. Millions of dollars could be saved by shortening the preselecting phase where less potential compounds could be eliminated instantly. Not to mention keeping animals safe and sound!

Ways to produce Monoclonal Antibodies

October 8, 2012, 6:33 am

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Our immune system acts as the protective shield of our body against various infections by bacteria and virus causing various diseases. White blood cells, the army of immune system is composed of neutrophils, eosinophil, basophil, lymphocyte and monocyte each carrying out its unique function in fighting against the foreigner entering the body. The B cells of the lymphocytes are the intelligent soldiers which recognize the type of foreign object (antigen) entering the body and releases a weapon called antibody to track the foreigner and destroy them. The two novel traits of an antibody are its specificity to the antigen and once induced its assurance to the body to provide continual resistance to the particular type of disease acquired. Baffled by these two unique features of an antibody, scientists decided to use them for the welfare of the human kind and developed techniques to produce antibodies in vitro. The result is the production of ‘Monoclonal Antibody’.




Monoclonal antibody is the term used for the antibody produced in vitro by multiplying a single hybrid cell, obtained by cloning selected cells from a single source. Monoclonal antibodies are known for its purity and specificity. The conventional method of monoclonal antibody production was done by injecting the test animal with a particular type of antigen. After few days of the dose of the antigen, blood is drawn from the test animal and the antibodies were extracted from the serum of the blood. This method was failure both qualitatively and quantitatively. The antibodies obtained were found to be impure (mixed variants) and the amount obtained was also significantly less. Hence adoption of cloning technique was identified as the optional method to produce antibodies in vitro.

In this method, scientists selected tumor cells for its ability to multiply intensively and the antibody producing mammalian cells and fused these two under in vitro conditions. On the onset of the production, the test animal usually a mice is injected with an antigen to stimulate the antibody production. The antibody producing cells are identified and extracted from the spleen of the mice and it is fused with the myeloma cells which were extracted from the mice earlier and cultured in vitro. The resulting hybrid cell or hybridoma is observed for the presence of the desired antibody and once satisfied, the hybrids are subjected to grow in culture to produce splendid quantity of monoclonal antibodies. Again, the extraction and purification of the monoclonal antibody from the hybridoma is done by sequence of processes like centrifugation, filtration, ultra filtration or dialysis and ion exchange chromatography. Later the ion exchange chromatography was replaced by size exclusion chromatography which was found to be more effective in purifying. Also a procedure called affinity purification was employed to obtain the maximum purity. After undergoing the steps of purification, the final product, the monoclonal antibody is checked for the level of purity by using either chromatogram or gel electrophoresis or capillary electrophoresis.

The first test animal used for the production of monoclonal antibody is mice and a consequence reaction like allergy was observed in humans when supplemented with the monoclonal antibodies produced from mouse cell. Also, humans responded only to the initial dose and developed resistance to further doses. This posed as a bigger problem in obtaining the benefits of the monoclonal antibody and as a result evolved the chimeric antibody. The chimeric antibody is developed by inserting some human amino acid sequence into the animal developed monoclonal antibody.

The novel idea of developing fully human monoclonal antibody is a major breakthrough in the production of monoclonal antibody. In this method, blood sample is collected from an individual (donor) recovered from a particular type of infection and the antibody specific cells are extracted and immortalized. These cells are then subjected to micro well assay technique and the antigen specific antibodies are identified by fluorescence method and isolated. These cells are expanded and characterized before passing to other cell types for large scale production. The difficulty in identifying a donor is eluded by extracting cell from a healthy person and activating the cell for specific antibody production in vitro. The advancement in genetic engineering technology serves the human monoclonal antibody production by using transgenic mice.

The wide therapeutic application of monoclonal antibodies states the significance of the production of the monoclonal antibody.

Stem cells in Type I Diabetes treatment

October 9, 2012, 1:08 am

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Type I Diabetes is an epidemic disease of the modern times, which is non-infectious. In this disease, the beta cells in the pancreas are diseased or lost thereby affecting the insulin production, leading to abnormal blood sugar levels in the blood. The frequent dose of insulin injections can help the patients to maintain the blood sugar level in blood, but it does not provide any permanent solution. The curative treatment for the disease is the replacement of the lost beta cells with functional beta cells by pancreas or islet cell transplant. However, the shortage of donors has initiated for the study of alternative treatments for the same. The stem cell therapy has proved to be a very potent solution for the diabetes treatment compared to other treatments as the disease is characterized by the loss of a single type of cells in the disease and hence could be treated successfully if the cells could be replaced or replenished within the body.

The use of stem cells in the therapy involves at first the thorough study of the signalling mechanisms in the formation of the pancreatic beta cells from the embryonic stem cells, mainly the Notch signalling mechanism, which stimulates the creation of the beta cells in the developing foetus after inhibiting the same at first. With the study of the various signalling processes within the body, the scientists have succeeded in the formation of functional beta cells in pancreas, which secrete insulin, from the embryonic stem cells. Stem cells could also provide an alternate treatment by helping in the pancreatic recovery, thereby helping in the replenishment of the beta cells secreting insulin. It has been proved by the successful study in mouse models that when the gene for the vascular endothelial growth factor (VEGF) is expressed in the modified bone marrow stem cells, the pancreatic recovery is sustained with the formation of new beta cells, thereby helping in insulin production. The modified stem cells help in the formation of new blood vessels and activate the genes responsible for insulin production.

Type I diabetes results due to autoimmune disorder, in which the immune cells affect and destroy the pancreatic beta cells, thereby affecting insulin production. Research studies have shown that the aggression of the immune system can be treated with the combination of stem cell therapy and immune suppression drugs. In this treatment, the abnormal immune system cells are suppressed and destroyed by the drugs and are then, replaced by the immature stem cells, which differentiates into normal immune system cells, thereby preventing the destruction of beta cells and help cure Type I diabetes. Cord blood stem cells have also been used for the treatment of the autoimmune disorder of Diabetes, which follows the ‘Stem cell education therapy’. In this procedure, the cord blood stem cells of the healthy donor secreted the Autoimmune regulator (AIRE) that effected changes in the lymphocytes of the patient when they are co-incubated, thereby preventing the autoimmune attack on the pancreatic beta cells and helping in their recovery.





Research studies have shown that neural stem cells from the hippocampus and olfactory bulb were successful in differentiating into pancreatic beta cells when transplanted into the pancreas of diabetic rats and could secrete insulin, thereby helping in the diabetes treatment. This could provide a solution for the non-availability of donors of stem cells or pancreas as the patient himself could be the donor of neural stem cells essential for the treatment. However, in-depth research is essential for translating the studies on rodents to that on human patients.

In the treatment of diabetes, the stem cell therapy is indicated in almost all the stages of the diseases. However, it is most effective when applied in the initial onset of the disease; in case of renal failure in the diabetes patients; immunodeficiency disorders; development of Diabetes mellitus Type II, etc. Although, the stem cell therapy may prove to give beneficial results on the sufferers, but the scientists need to study thoroughly the possible side effects on the other mechanisms within the body, which is possible only by carrying out further scientific investigation on the subject. The pathways of the differentiation processes must be elucidated properly for the translational studies on higher animals as the research has been carried out mainly on rodent models. A revolution in the world of therapeutics can be expected in future, keeping the vast scope of stem cell research in mind.

What is DNA Nanotechnology and its types?

October 9, 2012, 2:02 am

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DNA nanotechnology is broadly divided into two branches - Structural and Dynamic DNA nanotechnology.

What is Nanotechnology?
Nanotechnology is the field of science and technology which is concerned with studies of substances and systems at the atomic and molecular level which is generally 100 nanometers or smaller. It is a rapidly developing field, the societal implications of which are already evident. And DNA nanotechnology is branch which aims to create novel, controllable nanostructures out of DNA by using its unique molecular recognition properties and to achieve molecular self-assembly through the manipulation of DNA. It is a technology in which molecular components spontaneously organize into stable structures; this form of structures is induced by the physical and chemical properties of the components selected by the designers. These components have strands of nucleic acids such as DNA, which are constructed in nanoscale as a nucleic acid double helix has a diameter of 2 nm and a helical repeat length of 3.5 nm. The most important property of nucleic acids is that the binding between two nucleic acid strands depends on simple base pairing rule which helps in assembly of nucleic acid structures easy to control through nucleic acid design. This technology is used in manufacturing of various nanomedicine which is used for various treatments of various diseases. It is helping scientists and researchers in creating synthetic vaccines that could one day help treat and prevent many potentially fatal diseases like cancer, AIDS, Hepatitis, influenza, etc.

DNA nanotechnology has two broadly divided branches-

One is Structural DNA nanotechnology (SDN) which focuses on synthesizing and characterizing nucleic acid complexes and materials that assemble into a static, equilibrium end state. It uses unusual DNA motifs to build target shapes and arrangements and these are generated by reciprocal exchange of DNA backbones, leading to branched systems with many strands and multiple helical domains. The motifs may be combined by sticky ended cohesion, involving hydrogen bonding or covalent interactions and other forms of cohesion involves edge-sharing or paranemic interactions of double helices. Some of these motifs are simple branched junctions, but other motifs represent more complex strand topologies, with greater structural integrity. Other than this double crossover (DX), triple crossover (TX), paranemic crossover (PX) and parallelogram motifs are of great use. The sequences of these unusual motifs are designed by an algorithm that attempts to minimize sequence symmetry. A core goal of DNA nanotechnology is the self-assembly of periodic arrays. Micron-sized 2-dimensional DNA arrays from DX, TX and parallelogram motifs can be constructed. Patterns can be changed by changing and modifying the components after assembly. DNA molecules have been used successfully in DNA-based computation as molecular representations of Wang tiles, who’s self-assembly can be programmed to perform a calculation.

The other is Dynamic DNA nanotechnology which focuses on creating nucleic acid systems with designed dynamic functionalities related to their overall structures, such as computation and mechanical motion. Some complexes have a combination of both the subfields such as nucleic acid nanomechanical devices. DNA complexes change their structure with change in some stimulus, making them one form of nanorobotics which is designed to have a dynamic reconfiguration after the initial assembly. Various devices like circuits, catalytic amplifiers, autonomous molecular motors and reconfigurable nanostructures have been designed to use DNA strand-displacement reactions where two strands with partial or full complementarity hybridized by displacing one or more pre-hybridized strands. This mechanism allows for the kinetic control of reaction pathways and buffer is required. Some systems can change with the change in control strands thus forming multiple devices which independently operate in buffer solution. Cascades of strand displacement reactions can be used for either computational or structural purposes and are energetically favorable through the formation of new base pairs, and the entropy gain from disassembly reactions. These cascades are conducted under isothermal conditions for the assembly or computational process. They can also support catalytic functionality of the initiator species, where less than one equivalent of the initiator can cause the reaction to go to completion. These strand displacement complexes are used to form molecular logic gates capable of complex computation and these molecular computers use the concentrations of specific chemical species as signals. In nucleic acid strand displacement circuits the signal is the presence of nucleic acid strands that are released or consumed by binding and unbinding events to other strands in displacement complexes.

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Careers in Biotechnology - List of various options

October 9, 2012, 11:23 am

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Various biotechnology careers include forensic DNA analyst, scientist, clinical research associate job, laboratory assistant, microbiologist, greenhouse and field technician, bioinformatics specialist, animal caretaker and many more.

CareerBliss.com conducted a survey to find out what are 10 happiest professions in America. Conclusions were made after 200.000 people working 70.000 different jobs were interviewed. A lot of things were taken under consideration: how much people appreciate their daily tasks, bosses, co-workers, salary, company culture and reputation…All examined subjects ranked how investigated factors correlate with their overall satisfaction. Salary wasn't most important factor for employee’s happiness. Type of a daily jobs, control over work done and relationship with colleagues were considered most important. Career that combines all necessary factors to make people enjoy time spent in their offices (laboratories) – is career in biotechnology!

Biotechnology is combining knowledge about life and living organisms with modern technology to create new systems, devices, materials, food…that could improve human life and help preserve environment. Most biotechnology products are associated with agriculture, food industry and medicine, and logically - careers in those fields are most popular.

A list of careers in biotech is long; here are few that sound really interesting:

Laboratory Assistant

Scientific laboratory could perform different kind of research, but as a laboratory assistant your main duties will be sampling, measuring, collecting and analyzing investigated data… Maintenance of laboratory equipment such as centrifuges, titrators, pipetting machines…is also one of the tasks. Laboratory tests and strict methodology are very important especially when hazardous material is under investigation. Besides using typical lab equipment in work – computational analysis of given data is also important. High quality laboratory work is necessary for later research and development stages.

Greenhouse and Field Technician

Modern agricultural research is dealing with new, genetically modified plants. As a greenhouse and field technician, you’ll be in charge for planting seeds, pollinating plants, applying fertilizers and pesticides. Special attention to the problems that may arise (pest, disease…) is extremely important as those are genetically modified organisms. Basic knowledge of equipment used in everyday work as well as computer knowledge is also very important for this position.

Forensic DNA Analyst

This position is usually associated with crime laboratories where DNA analysis is performed to solve legal issues. Urine, saliva, blood, semen, hair…those are the samples that could be used for DNA analysis. After sample collection, DNA is extracted and analyzed using couple methods (PCR, electrophoresis). Final results are further compared with the already known DNA profiles. Methodology is strict: properly collected and stored evidence, documentation on technical laboratory details and well written final reports are essential for successful prosecution. Depending on the laboratory size, employees could be more or less specialized.

Clinical Research Associate

Clinical research associate (CRA) is monitoring clinical trials on a new drug. After preclinical studies (when tested on animals) are finished, drug is entering clinical trials where (depending on the study phase) smaller or larger group of people will be evaluated for possible adverse effects. CRA is included both in study design and in writing reports using given results. Close monitoring is especially important to make sure that protocol is not violated. Clinical data is collected, summarized and analyzed to help made final conclusion on a drug effect.

Bioinformatics Specialist

Bioinformatics is combining biology and computers. Data derived from various studies (DNA associated experiments, for example) is gathered in the computers. Software is in charge for data organization, manipulation and final analysis. Data mining is useful way to collect lot of publically available and jet relevant data that could be used in different experimental stages (for comparison or quick information extraction) or to help merge data from different sources. Programming skills are necessary for software and database manufacture and maintenance.

Animal Caretaker

Animal caretaker is nurturing animals used in biotech research. List of species used is long: all the way from mice and rats to cows and chimps. Water and food supplies, cage cleaning, animal health monitoring, relocation, milking, artificial insemination… a lot of duties need to be performed and not all tasks are representative. If you put aside that animals have specific odor (and different bodily fluids and excretions) keep in mind that watching animal suffer during experiments isn’t easy or nice thing to do.

Number of people working in biotech industry in USA is exciding 180.000. List of possible occupations is long and will expand as biotech is growing and moving in various directions with each new day. You just need to figure out what part of it you like the most.

Development of Drosophila

October 9, 2012, 6:47 pm

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Drosophila, known as fruit fly is widely used as a model organism in genetic studies for studying mutations, inheritance patterns etc. Drosophila melanogaster is a holometabolous insect. An adult fly has three basic body parts; head, thorax and abdomen. Thorax consists of three segments with legs, winds and halters. Abdomen has 11 segments. Large number of mutations in the fruit fly influences all aspects of their development and there mutations have been subjected to molecular analysis to find how the genes control early development in Drosophila.

When a Drosophila egg has been fertilized, its diploid nucleus immediately divides nine times without division of the cytoplasm creating a single multinucleating cell. After 8th division, nuclei get scattered in the cytoplasm followed by formation of 4 polar nuclei in 10th division. In the 13th division, nuclei divides and numerous nuclei are found in the periphery. This is called syncytial blastoderm. Each of these nuclei proved to have their own cytoplasmic environment rich in microtubules. Plasma membrane invaginates and each nuclei are surrounded by a membrane which are called as cellular blastoderms. This has about 6000 cells. Polar cells give rise to germ cells and embryo undergoes further development. Three important genes are involved in the development of Drosophila; maternal effector genes/ egg polarity genes, segmentation genes, homeotic genes.

Egg polarity genes function in axis specification. These genes act by setting up a concentration gradient of morphogens in the developing embryo. A morphogen is a protein whose concentration gradient affects the developmental fate of the surrounding region. The egg polarity genes are transcribed into mRNA in the course of egg formation in the maternal parent and this maternal mRNA are incorporated in the cytoplasm of the egg. Proteins encoded by these mRNA play an important role in axis determination. These proteins are examples of maternal inheritance as the offspring will have similar phenotype.

Like in all other insects, fruit fly has a segmented body. When axis specification has taken place, segmentation genes control the differentiation of the embryo into individual segments. About 25 genes are included in segmentation genes. They are zygotic genes whose expression is controlled by bicoid and nanos protein gradients. Gap genes in segmentation genes are involved in defining large segments of embryo. Pair rule genes define regional sections of the embryo. Segment polarity genes are involved in organization of segments. Mutations in these genes lead to absence of certain segments.

Gap genes, which are regulated by maternal genes, are involved in dividing the embryo into broad regions each containing parasegment primodia. Hunchback proteins are expressed at the anterior end. Transcription of anterior gap genes are initiated by the different concentrations of hunchback and bicoid proteins. Higher concentration of hunchback proteins results in expression of giant proteins and prevents transcription of posterior gap genes in the anterior part whereas lower hunchback concentrations result in expression of kruppel proteins. Giant gene has two methods of activation; one for anterior expression band and one for posterior expression band. After this, gap genes become stabilized and maintained by interactions between different gap gene products. Protein products of gap genes interact with neighbouring gap gene proteins to activate transcription of pair rule genes. These proteins divide the embryo into areas that are precursors of segmented body plan. Expression of these genes results in zebra stripe pattern along the anterior posterior axis, dividing the embryo into 15 subunits. Eight pair rule genes are known which include hairy, even skipped, runt etc. Mutations in these genes results in deletion of particular stripe. Pair rule proteins activate the segment polarity genes.

Segment polarity genes are responsible for organization of the segments. Mutations in segment polarity genes lead to deletion of part of the segment and replaced by a mirror image of the adjacent segment. Gene products of segment polarity genes play an important role in cell to cell signaling. They encode proteins that are involved in signal transduction pathways.

Homeotic genes are involved in determining the identity of individual segments. Homeotic gene products activate genes that encode segment specific characters. Mutations lead to specific body parts to appear in wrong segments. Homeotic genes create addresses for the cells of particular segments indicating the cells where they are within the region defined by segmentation genes.

Microbial contributions to Molecular Biology: Enzymes, plasmids, cosmids

October 9, 2012, 8:16 pm

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Molecular Biological methods are dealing with isolation, amplification, modification, identification of genetic material. These procedures make use of biological tools such as enzymes, primers, plasmids etc. Most of these are isolated from microbes which are of great importance. Ability of these enzymes and other compounds to withstand different in-vitro conditions is the reason why they are used for experimental purpose.

DNA polymerase is the master blaster enzyme used in molecular methods such as Polymerase Chain Reaction (PCR). This enzyme catalyzes synthesis of DNA. This enzyme has 5’ exonuclease activity, proofreading activity additional to DNA synthesis. DNA polymerase used in vitro conditions is isolated from the bacterium Thermus aquaticus which is highly thermostable and functions optimatimally at the temperature range of 750C-800C.

Restriction enzymes are widely used biological tools in Molecular biology. These are known as Molecular scissors. These enzymes have the ability to cut DNA recognizing a specific sequence. There are 4 types of restriction enzymes. Type II and Type IV are used in recombinant DNA technology. Restriction enzymes are named with the bacterium of which it has been isolated and corresponding number of the restriction site. Some recognition enzymes have a separate recognition site and a cleavage site while in some both are the same. Restriction enzymes with same cleavage and restriction site are called as Isochizomers. Type II enzymes are very stable which requires Mg2+ as cofactor and shows star activity ( change in specificity). Few examples for restriction enzymes are E co RI, Pvul I, Hae III, Alu I, Hpa I.

DNA ligases have the ability to join two DNA fragments which is called as ligation of DNA. Ligation depends on the type of ends to be joined whether sticky or blunt. This enzyme is usually isolated from E. coli cultures which are infected with T4 phage for genetic engineering. T4 ligase is capable of carrying out ligation invitro conditions. DNA ligase functions optimally at 370C.

Alkaline phosphatases are another group of enzymes used in Recombinant Technology. When plasmid vector for joining a foreign DNA fragment is treated with restriction enzymes, the cohesive ends of the broken plasmids instead of joining with foreign DNA join the cohesive end of the same DNA molecules and get re-circularized. To overcome this problem, restricted plasmid is treated with alkaline phosphatase which digests the 5’ phosphoryl group so that 5’ end of foreign DNA can covalently join to 3’ end of the plasmid. This enzyme is a diametric glycoprotein made up of two identical units and isolated from E.coli.

Reverse transcriptase enzyme is isolated from Avian Myeloblastosis virus which requires Mg or Mn for initiation of reverse transcription. To obtain DNA to clone a eukaryotic gene is more complicated because these contain regions called as introns that are non-coding regions. This enzyme cut introns out of mRNA and produce intron free DNA which is called c DNA.

Plasmid vectors are closed circular double stranded extra chromosomal units and widely used in recombinant DNA technology for carrying specific genes into an organism. Plasmids are used as they have the ability to self-replication. Plasmids used in genetic engineering carry specific genes called as marker genes which enable the selection of recombinant organisms in later stages. These marker genes include antibiotic resistant genes, genes for toxin production etc. These contain restriction sites which can be cleaved with restriction enzymes and can be replaced by gene of interest. Size of a plasmid ranges from 1-200kb. Example for plasmids is Ti plasmid isolated from Agrobacterium tumefaciens.

Apart from plasmids isolated from bacteria, viruses are also used as cloning vectors due to its ability of infection. Mostly, they are used as plant vectors. Cauliflower mosaic viruses, Gemini virus, Tobacco Mosaic Virus are some viruses used. As most of the viruses contain RNA as the genetic material, gene regulation functions through production of c DNA by reverse transcription. In contrast to plasmids, viral vectors can incorporate only a small fragment of DNA. Simian Virus, Vaccinia Virus and Retro Virus are some animal vectors. Vaccinia virus is used in vaccines to produce immunogenicity.

Cosmid is a hybrid between a plasmid and a bacteriophage DNA. These contain cos sequences of bacteriophages which directs insertion of DNA. Bacteriophages are viruses that infect bacteria. Cosmid is almost similar to a plasmid which has a origin of replication, restriction sites and marker genes.

A New Discovery for Migraine Treatment - TRESK Channels

October 9, 2012, 10:06 pm

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The TRESK channels have paved way for the development of potential treatments for migraine.

Migraine is a chronic neurovascular disorder characterized by severe, episodic headaches often accompanied by other symptoms like nausea, phonophobia or sensitivity to sound, photophobia or sensitivity to light, vomiting, etc. A symptom usually precedes the migraine headache, which is a transient, focal, neurological phenomenon, known as aura, which is actually loss of vision or flashes of light. The differences between the causes for the migraine with aura (MA) and the migraine without aura (MO) are not clearly known and some patients experience the symptoms of both the types of migraine.

The exact cause of the migraine was not known until few years back, but successful genetic studies have shown that MA is a genetic disorder and results from some faulty genes, which makes some people predisposed to the migraine condition. The cortical spreading depression (CSD) results in the migraine aura, which is a wave of the depolarization in the pain neurons and the glial cells followed by inactivity and spreads over the entire cortical region. The trigeminal system (TGVS) is activated by the CSD initiating headache. This projects to the brain stem, which in turn projects to the other pain centres in the brain. However, the presence of a link between CSD in MO is not known yet. It has been seen that in some cases migraine like symptoms result due to severe stress or hormonal imbalance, etc, though there is no concrete evidence to prove it.

In case of the genetic disorders, it is often seen that a combination of mutations in several genes result in the disease. However, in the study of Migraine, a genetic disease, it is seen that a defect in a single gene may result in the formation of the disease. MA is also known as Familial hemiplegic migraine. Recent studies have shown that defect in the ion channels and its transporters may be responsible for the formation of the disease. As it is known that ion channels play an important part in the excitability of a nerve, hence a defect in the ion transporters which transport ions in and out of the nerve cells may affect the excitability of the nerve. It is seen that in the migraine sufferers, the excitability of the nerves increases, thereby hinting the presence of fault in the ion channels and its transporters.

While studying the ion transporters and its genes, the latest discovery in relation to the disease has been the identification of a mutation in the TRESK gene in the family of DNA sufferers, by DNA sequencing method. The TRESK gene is responsible for the formation of the protein TWIK related spinal cord potassium channel (TRESK). The TRESK is responsible for the transmission of signals between the nerve cells. It is a potassium channel, which causes the efflux of the potassium ions from the nerve cells. It is mainly associated with the pain pathways because on stimulation, it numbs the pain and prevents the passage of pain signal between the nerve cells. Hence, it plays an important role in the action of the anaesthetics. A mutation in this gene thereby causes increased sensitivity of the nerve cells. Moreover, the TRESK is abundantly present in the trigeminal ganglion region of the brain, which is the major part associated with the transmission of the pain stimuli in the brain. The presence of mutation in this gene was noted in only one large family of migraine sufferers, while the majority of other migraine sufferers showed absence of the same. Hence, it remains to be studied if other less severe defects in the TRESK gene or defects in the genes or proteins associated with it could be a possible mechanism for migraine formation.

The discovery of drugs stimulating the TRESK channel may prove to be an effective treatment, though they may not be potent in case of complete loss of the function of the channel. Moreover, gene therapy for defective TRESK channels may also be a potential ground for research. The ongoing research on the subject may initiate better forms of treatment for the prevalent disease, though extensive, in-depth study is essential for knowing the underlying molecular mechanisms behind the formation of the disease.

Identity to Organisms: DNA Sequencing

October 9, 2012, 10:52 pm

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DNA, our genetic material provides identity to our characters. Being the universal genetic material for higher organisms, it is almost similar in one organism. This method of identification is known as DNA sequencing which is widely used in taxonomic studies etc. DNA sequencing is different from DNA fingerprinting as it involves determining base sequence rather than comparing DNA fragments.

DNA is made up of thousands of nucleotides which in triplet codons encode specific proteins. Order of nucleotides in DNA is called the DNA sequence which is commoner in one organism. There are specific regions common to one type of organism. As the total sequence is huge, only the specific region required to identify one type of organism is sequenced for example, ITS region for fungi, 16s r RNA region for bacteria etc. These regions are amplified by using specific primers prior to sequencing. Species specific primers which are part of these regions corresponding to unique products of different species can be used to generate more accurate results.

Prior to DNA sequencing, DNA of interest is isolated, purified and amplified by Polymerase Chain Reaction (PCR). PCR results in millions of copies of the DNA fragment to be sequenced. Two methods are used in DNA sequencing; Chain termination method/Sanger Coulson Method and Chemical Degradation Method/ Maxam-Gillbert method.

Sanger Coulson method requires the DNA to be sequenced to be cloned into a vector (M13). In Chain termination method, strand synthesis is done with the help of modified DNA polymerase which is called as kleno fragment with polymerase activity. This strand synthesis involves PCR reactions and different from usual DNA synthesis as this makes use of di-deoxynucleotides which lacks 3’ Hydroxyl group. When this special type of nucleotides is used, after this nucleotide other nucleotides cannot be added which results in chain termination. Fragments of different length can be obtained. Four vials corresponding to four types of nucleotides consisting of Adenine, Guanine, Cytosine and Uracil. Only one type of dideoxy nucleotide is added to one vial. Out of the four deoxynucleotides one should be radiolabelled with P32 or S35 isotopes. In each vial, stand synthesis and amplification takes place by PCR. After the reaction, the DNA fragments are separated by gel electrophoresis. This gel is incorporated with urea which makes double stranded DNA into single stranded DNA. Since the difference in length between two fragments can be small as a nucleotide, the electrophoresis process should be well controlled. The amplified products in four vials are run separately and based on the position of the band the sequence can be determined.

In chemical degradation method, primers are not required as it doesn’t involve DNA synthesis. And this method does not require the DNA to be cloned into a vector. It involves chemicals to degrade DNA. The double stranded DNA to be sequenced is labeled with a radioactive phosphorous group at 5’ end using the enzyme polynucleotide kinase. Dimethyl sulphate is added to the labeled DNA and heated to obtain single stranded DNA. Generally assuming that one template strand contains more purines and is heavier, the other strand will move faster in a gel during separation. The amplified DNA samples are taken in four vials.
In the first vial, Dimethyl sulphate brings about a chemical modification of a specific nucleotide. It acts on Guanine and makes a nucleophillic attack 7th Nitrogen and it becomes unstable. This instability leads to breakage of DNA strand at that point. By adding piperidine, unstable Guanine is removed. Dimethyl sulphate in acidic medium is used for the second tube. This will attack purines; Adenine and Guanine, and chemically modify the bases. In the third tube, hydrazine is added along with piperidine. Hydrazine interacts with Cytosine and brings about a chemical change. Hydrazine in an alkaline medium is used for the fourth tube followed by piperidine which react with pyrimidines. Only a single break is made in one strand. These tubes treated with different chemicals are subjected to gel electrophoresis.

DNA fingerprinting, in contrast compare the variable number of tandem repeats (VNTR) in human DNA for identification. These are non-coding sequences of which number of repetitions is unique to a person. This is widely used in forensic investigations and paternity testing.