Gel Electrophoresis

Gel electrophoresis is a laboratory technique used to separate water soluble macro molecules like DNA, RNA, Proteins depending on their molecular weight and charge. For DNA molecules, the main factors determining the separation is molecular weight. But for protein molecules, iso-electric point and charge is also important.

The samples are placed inside wells created in the gel and electric field is applied across the gel matrix. The samples will then move in either direction or towards one direction depending on the above factors. What ever the type of electrophoresis, the mechanism and the basis is the same.

There are mainly two types of electrophoresis techniques.

Agarose Gel Electrophoresis

Most frequently used technique is Agarose Gel Electrophoresis. The Gel matrix is made using Agarose, which is a purified form of agar. Agar is extracted from seaweed or by human waste. A buffer is used when making the gel, and the gel is embedded in this buffer at the time of electrophoresis. This will enable the electric current to pass through the solution in the form of ions.

There are three commonly used buffers,

1. Tris - EDTA

2. Tris - Acetate

3. Tris - Borate

Below is a Electrophoresis machine with a casted gel. There are wells created inside the gel. In this example the wells are created near the (-) electrode, because we are using DNA as our samples. But if you are using Proteins, the wells should be created at the center of the gel, because net charge can be either (-) or (+).

Then when loading the samples, our samples have to be mixed with a dye, so that we can observe the movement of samples through the gel. The dye that is been used here moves through the gel equivalent to a nucleotide strand of 200bp.

Then as seen in the picture a voltage should be given to create an electric field, which will enable the samples to move towards the (+) electrode.

This can be used to separate nucleotide strands of 100bp to 20,000bp. It has a limited resolution. (resolution is the ability of the gel to separate nucleotide strands of different lengths clearly). To gain a higher resolution, we can increase the agarose concentration, which will increase the Resistance through the gel. But since the resistance will also increase, the time taken to run the gel will also be increased from hours to days.

After running the gel, we can see the separation under UV light.

For tasks that require higher resolution (greater separation), PAGE (poly acrylamide gel eletrophoresis) is used. PAGE can clearly separate nucleotide fragments to show one base pair (1bp) difference. It is used in tasks like DNA, RNA sequencing.

BiotechPracticals

DNA Extraction

DNA extraction is one of the basic steps in genetic engineering or modern biotechnology. Biotechnology in anyway is not a new science. Our anscesters have been using biotechnology for thousands of years. Biotechnolgy is any technology involving living organisms or biological products made by those organism. When humans manupulate biological processes within these organisms we call it biotechnology. So this is a very broad area. It has branches in Medicine, Agriculture, Industry and Environment.

Biotechnology over the years have evolved into more sophisticated science and is one of the most talked subjects in the world. No matter what field of biotechnolgy you are involved DNA extraction has same basic principles.

There can be many sources for DNA.

ex:

plant sources: grains, rice germs, plant leafs, any other suitable plant product.

if you want a bulky extract it will be nice to use some thing like strawberry, which gives a high yield.

animal sources: Blood cells (WBC), any other animal tussue.

WBC is taken because it is easy to obtain.

note: When you take a blood sample, there are RBC:WBC in the ratio of approximately 300:1. So first we will have to remove RBC from the sample. To do that RBC are lysed by a freez shock. Then only cells to be remained in the sample are WBCs. But if you are using avian blood samples, there's no need for freeze shock as the RBC of avian blood contain nuclei.

Once we obtained the sample form the source, following have to be done.

1. Remove the cell membranes of the cells and get the intra cellular constituents in to the solution.
2. Degrade the Proteins and cell debris to release DNA
3. Separate DNA from other bio molecules (proteins, AA, ex..)
4. Purify DNA sample

There are many ways to achieve these goals with varying degree of purity to our DNA sample. You can even complete these steps using some of the house hold chemicals. But the purity of the sample will be far less than when you do it in the lab under proper protocols.

Today the theory and the procedures behind DNA extraction, Visualisation of DNA, Electrophoresis of DNA and quantification of DNA sample is done. Tomorrow we will be doing the DNA extraction practical followed by the Electrophoresis of DNA.

How did people find out that DNA is the genetic material

Genetic material is the core factor that determine the character of an organism. So to prove that DNA is the genetic material, it should be proved that DNA is responsible for the changes in an organism.

In 1928 Griffith did a simple experiment with pneumococci bacteria to prove the above. He selected a smooth strain (virulent) and a rough strain (non-virulent).

First He injected smooth strain to mice and all the mice died.

Then he injected rough strain to mice and all the mice tolerated it well.

Then he heat killed smooth strain and injected it to mice. Mice lived fine. When treated with heat, proteins get denatured and they loose their three dimensional shape and function. This step proves that the factor immediately responsible for virulency of the smooth strain is proteins.

Then he mixed heat killed smooth strain and live rough strain and cultured it in a new medium.

Then he extracted a sample from the culture and injected it to the mice. mice died. This Step shows that the core factor that was responsible for the virulency of smooth strain has some how transferred to the rough strain.
Now the character of rough strain or the virulency of rough strain has changed. Griffith termed this phenomenon as TRANSFORMATION.

When the DNA is extracted from the heat killed smooth strain and injected to mice, mice died. When extracted DNA is mixed with rough strain, the virulency of rough strain increased. This results proves that DNA is the component responsible for characteristics (in this case, virulency).

Hershay and Chase helped to establish the fact. They proved that only when phage DNA enter the host bacterial cells, new phage particles are formed.

Number 42

Today one of my friends asked me to google for,

"the answer to life, the universe, and everything"

See for your self, google calculator gives "42". Isn't it great.

haha it seems that google has unlocked the mistry of universe.

i searched for this some more and found some interesting facts.

• The number 42 is The Answer to the Ultimate Question of Life, the Universe, and Everything, according to Douglas Adams' series The Hitchhiker's Guide to the Galaxy. According to the fifth Hitchhiker volume, Mostly Harmless, 42 is the location of Stavromula Beta. Thus, 42 may be the world's longest written riddle, since the riddle of the question to the answer was raised in the first volume, and not answered until the final page of the fifth, and then passes unnoticed by the story's ever-bumbling characters.

It took "deep thought" 7.5 million years to compute the answer, but google does it in 0.03 seconds!!

keep it up google!

Biometrics: Unlocking Doors With Your Eyes

Research by Ms Phang, from QUT's Faculty of Built Environment and Engineering, is helping to remove one of the final obstacles to the everyday application of iris scanning technology.

Ms Phang said the pattern of an iris was like a fingerprint in that every iris was unique. "Every individual iris is unique and even the iris pattern of the left eye is different from the right. The iris pattern is fixed throughout a person's lifetime" she said.

"By using iris recognition it is possible to confirm the identity of a person based on who the person is rather than what the person possesses, such as an ID card or password.

"It is already being used around the world and it is possible that within the next 10 to 20 years it will be part of our everyday lives."

Ms Phang said although iris recognition systems were being used in a number of civilian applications, the system was not perfect. "Changes in lighting conditions change a person's pupil size and distort the iris pattern," she said.

"If the pupil size is very different, the distortion of the iris pattern can be significant, and makes it hard for the iris recognition system to work properly."

To overcome this flaw, Ms Phang has developed the technology to estimate the effect of the change in the iris pattern as a result of changes in surrounding lighting conditions. "It is possible for a pupil to change in size from 0.8mm to 8mm, depending on lighting conditions," she said.

Ms Phang said by using a high-speed camera which could capture up to 1200 images per second it was possible to track the iris surface's movements to study how the iris pattern changed depending on the variation of pupil sizes caused by the light. "The study showed that everyone's iris surface movement is different."

She said results of tests conducted using iris images showed it was possible to estimate the change on the surface of the iris and account for the way the iris features changed due to different lighting conditions.

"Preliminary image similarity comparisons between the actual iris image and the estimated iris image based on this study suggest that this can possibly improve iris verification performance."

Adapted from materials provided by Queensland University of Technology

Genetic Engineering - Intro

Biotechnology is technology based on biology, especially when used in agriculture, food science, and medicine. The United Nations Convention on Biological Diversity has come up with one of many definitions of biotechnology.

Biotechnology is often used to refer to genetic engineering technology of the 21st century, however the term encompasses a wider range and history of procedures for modifying biological organisms according to the needs of humanity, going back to the initial modifications of native plants into improved food crops through artificial selection and hybridization. Bioengineering is the science upon which all Biotechnological applications are based. With the development of new approaches and modern techniques, traditional biotechnology industries are also acquiring new horizons enabling them to improve the quality of their products and increase the productivity of their systems.

Before 1971, the term, biotechnology, was primarily used in the food processing and agriculture industries. Since the 1970s, it began to be used by the Western scientific establishment to refer to laboratory-based techniques being developed in biological research, such as recombinant DNA or tissue culture-based processes, or horizontal gene transfer in living plants, using vectors such as the Agrobacterium bacteria to transfer DNA into a host organism. In fact, the term should be used in a much broader sense to describe the whole range of methods, both ancient and modern, used to manipulate organic materials to reach the demands of food production. So the term could be defined as, "The application of indigenous and/or scientific knowledge to the management of (parts of) microorganisms, or of cells and tissues of higher organisms, so that these supply goods and services of use to the food industry and its consumers.

Closest Look Ever At Native Human Tissue

"This is a real breakthrough in two respects," says Achilleas Frangakis, group leader at EMBL. "Never before has it been possible to look in three dimensions at a tissue so close to its native state at such a high resolution. We can now see details at the scale of a few millionths of a millimetre. In this way we have gained a new view on the interactions of molecules that underlie cell adhesion in tissues -- a mechanism that has been disputed over decades."

So far, the only information available about a protein's position and interactions in a cell was based on either light microscopy images at poor resolution or techniques that remove proteins from their natural context. Frangakis and his group have been developing a technique called cryo-electron tomography, with which a cell or tissue is instantly frozen in its natural state and then examined with an electron micro-scope.

Electron microscopy normally requires tissue to be treated with chemicals or coated in metal, a procedure that disturbs the natural state of a sample. With cyro-electron tomography, images are taken of the untreated sample from different directions and assembled into an accurate 3D image by a computer.

The researchers applied this technique to observe proteins that are crucial for the integrity of tissues and organs like the skin and the heart, but also play an important role in cell proliferation. These proteins, called cadherins, are anchored in cell membranes and interact with each other to bring cells close together and interlink them tightly.

"We could see the interaction between two cadherins directly, and this revealed where the strength of human skin comes from," says Ashraf Al-Amoudi, who carried out the work in Frangakis' lab. "The trick is that each cadherin binds twice: once to a molecule from the juxtaposed cell, and once to its next-door neighbour. The system works a bit like specialised Velcro and establishes very tight contacts between cells."

The new insights into the cadherin system broadens the understanding of structural aspects of cell adhesion and shed light on other crucial processes such as cell proliferation. The technical advances achieved in cryo-electron tomography of frozen sections open up new possibilities to study more systems at native conditions with molecular resolution.

Adapted from materials provided by European Molecular Biology Laboratory

Global Climate Change: The Impact Of El Niño On Galápagos Marine Iguanas

According to the authors, recurring El Niño events provide an ideal system to study the impact of human-mediated climate change on ecosystems worldwide, by allowing observation of changes in populations associated with individual events.

"Since global warming is expected to cause an increase in the strength and frequency of El Niño events, it is important to evaluate the impact of El Niño on natural populations and their capacity to respond to environmental stresses," said Gisella Caccone, senior research scientist in ecology and evolutionary biology at Yale, and senior author of the paper published recently in the Public Library of Science One.

In this study, the researchers investigated the effect of sea surface warming associated with the single, intense El Niño event of 1997 to 1998 on genetic diversity in Galápagos marine iguana populations. They found that populations within the same species responded very differently.

Collaboration between German scientists who fortuitously collected and archived samples between 1991 and 1993 and Yale researchers who sampled the iguanas in 2004 enabled these unique before-and after comparisons. More than 800 samples from 11 Galápagos marine iguana populations were evaluated.

The researchers looked for changes in levels of genetic variation in nuclear microsatellite DNA and mitochondrial DNA markers of samples collected before and after this El Nino event. Changes in microsatellite frequency are sensitive enough to detect low population sizes before there is a significant loss of diversity in a population, whereas mitochondrial markers only show losses of diversity.

Caccone said that although some populations had mortality rates of up to 90%, only one population from a single island showed strong evidence of a "genetic bottleneck," suggesting that the El Niño-induced disturbance affected populations very differently even within the same species.

"Our study points out that there was a low population size on the island of Marchena during the same period in which there was serious volcanic activity as well as the El Nino," said Yale graduate student Scott Glaberman, a principal author of the study. "Since both of these forces could have acted on the population, it shows the importance of knowing the major forces influencing survival and reproduction to best interpret the results of genetic tests.

"The most striking result of our study is that although marine iguanas on some islands had a rather high mortality due to El Niño, the genetic consequences were mostly absent," said author Sebastian Steinfartz a postdoctoral fellow. "This unique study shows that natural populations may be able to balance even severe short term climatic disturbances, and that such fluctuations will not necessarily have long-term negative consequences on the population structure."

"Basic surveys and ecology of organisms are not the most glamorous aspects of research, but if used together with the exciting genetic approach in our study, they make for a very powerful approach," said Glaberman.

"This underscores the importance of having baseline studies for any population of interest, and the value of archiving samples for the use of future research," Caccone said. "It sets the basis for future research to determine which environmental and biological factors make specific populations more vulnerable than others."

Other authors on the study are Deborah Lanterbecq at Yale, Cruz Marquez at the Charles Darwin Research Station, Santa Cruz, Galápagos, Ecuador and Kornelia Rassmann in Germany. Granting from the National Geographic Society, the German Research Community, the Belgian American Educational Foundation, and the Yale Institute for Biospheric Studies supported the research.

Citation: Public Library of Science (PLoS): December 12, 2007.

Adapted from materials provided by Yale University

Using Carbon Nanotubes To Seek And Destroy Anthrax Toxin And Other Harmful Proteins

Scientists have long been interested in wrapping proteins around carbon nanotubes, and the process is used for various applications in imaging, biosensing, and cellular delivery. But this new study at Rensselaer is the first to remotely control the activity of these conjugated nanotubes.

A team of Rensselaer researchers led by Ravi S. Kane, professor of chemical and biological engineering, has worked for nearly a year to develop a means to remotely deactivate protein-wrapped carbon nanotubes by exposing them to invisible and near-infrared light. The group demonstrated this method by successfully deactivating anthrax toxin and other proteins.

"By attaching peptides to carbon nanotubes, we gave them the ability to selectively recognize a protein of interest -- in this case anthrax toxin -- from a mixture of different proteins," Kane said. "Then, by exposing the mixture to light, we could selectively deactivate this protein without disturbing the other proteins in the mixture."

By conjugating carbon nanotubes with different peptides, this process can be easily tailored to work on other harmful proteins, Kane said. Also, employing different wavelengths of light that can pass harmlessly through the human body, the remote control process will also be able to target and deactivate specific proteins or toxins in the human body. Shining light on the conjugated carbon nanotubes creates free radicals, called reactive oxygen species. It was the presence of radicals, Kane said, that deactivated the proteins.

Kane's new method for selective nanotube-assisted protein deactivation could be used in defense, homeland security, and laboratory settings to destroy harmful toxins and pathogens. The method could also offer a new method for the targeted destruction of tumor cells. By conjugating carbon nanotubes with peptides engineered to seek out specific cancer cells, and then releasing those nanotubes into a patient, doctors may be able to use this remote protein deactivation technology as a powerful tool to prevent the spread of cancer.

Kane's team also developed a thin, clear film made of carbon nanotubes that employs this technology. This self-cleaning film may be fashioned into a coating that -- at the flip of a light switch -- could help prevent the spread of harmful bacteria, toxins, and microbes.

"The ability of these coatings to generate reactive oxygen species upon exposure to light might allow these coatings to kill any bacteria that have attached to them," Kane said. "You could use these transparent coatings on countertops, doorknobs, in hospitals or airplanes -- essentially any surface, inside or outside, that might be exposed to harmful contaminants."

Kane said he and his team will continue to hone this new technology and further explore its potential applications.

Details of the project are outlined in the article "Nanotube-Assisted Protein Deactivation" in the December issue of Nature Nanotechnology.

Co-authors of the paper include Department of Chemical and Biological Engineering graduate students Amit Joshi and Shyam Sundhar Bale; postdoctoral researcher Supriya Punyani; Rensselaer Nanotechnology Center Laboratory Manager Hoichang Yang; and professor Theodorian Borca-Tasciuc of the Department of Mechanical, Aerospace, and Nuclear Engineering.

The group has filed a patent disclosure for their new selective nanotube-assisted protein deactivation technology. The research project was funded by the U.S. National Institutes of Health and the National Science Foundation.

Adapted from materials provided by Rensselaer Polytechnic Institute.

Bio Technology

I selected to do Bio Technology for my electives, So i'll have to learn something on biotech. Ok, let's start with some definitions.

According to Oxford medical dictionary it is,

"the development of techniques for the application of biological processes to the production of materials of use in medicine and industry"

NIH gives following definition,

"A set of biological techniques developed through basic research and now applied to research and product development."



So it's all about finding new solutions to old problems. that's cool isn't it.

Official Gmail Blog: 5 little-known Gmail features you may not yet know about

Official Gmail Blog: 5 little-known Gmail features you may not yet know about

Android

Android™ will deliver a complete set of software for mobile devices: an operating system, middleware and key mobile applications. An early look at the Android Software Development Kit (SDK) is now available.

Android was built from the ground-up to enable developers to create compelling mobile applications that take full advantage of all a handset has to offer. It is built to be truly open. For example, an application could call upon any of the phone's core functionality such as making calls, sending text messages, or using the camera, allowing developers to create richer and more cohesive experiences for users. Android is built on the open Linux Kernel. Furthermore, it utilizes a custom virtual machine that has been designed to optimize memory and hardware resources in a mobile environment. Android will be open source; it can be liberally extended to incorporate new cutting edge technologies as they emerge. The platform will continue to evolve as the developer community works together to build innovative mobile applications.

Cancer Staging

When cancer is diagnosed, the doctor will want to determine the stage, or extent, of the disease. Knowing a patient's stage helps the surgeon or oncologist (cancer specialist) make recommendations about the best course of treatment. Doctors will consider the chances of being cured by surgery alone, type of surgery that is likely to give the best possible outcome, and whether additional treatments (radiation, hormone, or chemotherapy) will be helpful. At the same time, the doctor will consider other factors, such as a patient's general health and treatment preference.

To determine the stage of a cancer, doctors use results from the physical exam, diagnostic tests including X-rays, ultrasound, biopsies, computerized tomography scans, magnetic resonance imaging, positron emission tomography, blood tests and other tests combined to create a picture of where the cancer is located, how large a tumor is (if a tumor is present), whether the cancer has spread, and what subtype of cancer it is.

Cancer staging applies to almost all cancers except for most forms of leukemia. Since leukemia involve the entire body, not a localized area like other cancers, staging doesn't make as much sense. A few forms of leukemia do have staging systems, though, which reflect how advanced the disease is.

Each type of cancer is staged according to specific characteristics. "In situ" cancers are cancers that have been diagnosed at the earliest possible stage.

There are two related cancer-staging systems: an overall stage grouping that uses Roman numerals, and the TNM system created by the American Joint Committee on Cancer.

Roman numeral staging

Stage I or "local" cancers have been diagnosed early and have not spread

Stage II cancer has spread into surrounding tissues, but not beyond the location of origin

Stage III or "regional" cancer has spread to nearby lymph nodes

Stage IV or "distant" cancers have metastasized - spread - to other parts of the body and are the most difficult to treat

The TNM staging system

The TNM Staging System is based on characteristics of the Tumor, Lymph Nodes, and Metastasis. Each of these is categorized separately and classified with a number to give the total stage. Basically, the larger the number, the greater the cancer involvement.

T: Tumor

T classifies the extent of the primary tumor, and is normally given as T0 through T4, with T0 representing a tumor that hasn't even started to invade the local tissues (in situ), to T4 representing a large primary tumor that has probably invaded other organs.

N: Lymph Nodes

N classifies regional lymph node involvement. Regional lymph nodes are those draining the area around the primary tumor. (Involvement of distant lymph nodes means the cancer has metastasized, or spread.) N0 means no lymph node involvement, while N4 means extensive involvement.

M: Metastasis

M is either M0 if there are no metastases, or M1 if there are metastases.

Translation - greatest choreography of all time!!

take a look at all the vids in the playlist. it's gr8

translation

ReGenesis

A science TV show

download intimate strangers teaser clip:

http://media.libsyn.com/media/flpradio/IS_teaser.mp4

A video documentary by the American Society for Microbiology

How Do Bacteria, Animals and Plants Adapts to Stress?

Both prokaryotic and eukaryotic cell quickly responds to stress or damaging atimuli. In response to a range of different stress , including heat shock , nutrients deprivation, and metabolic disruption, cells synthesize about two dozen different proteins (called stress proteins) .The most thoroughly studied stress is heat shock, in which a sudden increase in temperature includes the synthesis of a group of proteins. Genes that are responsible for the synthesis of heat shock proteins are among the most evolutionarily conserved genetics system s known. They are very similar in amino acid sequence in both prokaryotes and eukaryotes. Heat shock proteins accumulate to very high level in stress cells, accounting for as much as 15% of the total protein in E.coli.

The function of several of the heat shock protein is beginning to be understood. Most of these proteins are synthesized at low levels under normal growth conditions and play a vital role in protecting the cell from the damaging effects of heat and other stresses. The heat shock proteins hsp70 and hsp60 (the number refers to the molecular weight of the protein times 1000) are involved in assembly or disassembly of protein complexes.

Hsp70 is involved in translocating certain proteins trough intracellular membranes and binds to DNA replication complexes. Hsp60 has been found to interact with steroid hormone receptors. In plats hsps60 interacts with what may be the most abundant protein in the biosphere, ribulose-1,5-bisphosphate carboxylase-oxygenase, an enzyme that fixes CO2 in chloroplasts.

An amazing example of the use of heat shock proteins for protection in found in the desert- dwelling ant Cataglyphis bombycina , which is perfectly suited for life in the Sahara desert. Cataglyphis bombycina anticipates the high temperature of up to 1400 F found in the desert sand by producing heat shock proteins in abundance, even when in underground nests. These proteins seem to protect them to their natural conditions, grinding them up , and finding copious quantities of the heat shock proteins : a primitive strike against the searing temperatures.

Invading organisms also can produce stress proteins in the host. This can be detrimental because some of these proteins in the host. This can be deter mental because some of these proteins are very similar to the host’s stress proteins and create an autoimmune disease in the host’s organism. For example, researchers have shown that the hsp60 proteins from tuberculosis bacterial and human cells are sufficiently similar that they are they both recognized by antibodies from a tuberculosis patient.. Thus , a bacterial invasion may induce the body’s immune system to make antibodies to the stress protein of the bacteria, and these antibodies to the stress proteins of the bacteria, and these antibodies may also attack some of the body’s own vital proteins. It is believed that this may be the development process of some forms of chronic rheumatoid arthritis, which is an inflammation of the synovial membranes of joints.

Many Natural Product Are Mutagenic

In recent years, we have heard more and more about how our diet affect our health , especially in relation to the production of cancers. Research has shown that our diet contains an enormous variety of natural mutagens and carcinogens. It is also apparent that we are ingesting vastly greater qualities of these substances than was previously suspected. Perhaps this natural chemical product should be primary concern rather than the mutagenicity of industrial chemicals, food additives and pollutants in our environment. For example, in 1989 the United States had a big publicity –generated scare concerning the plant growth regulator Alar, which is used to delay ripening of apples so that they do not drop prematurely. Alar was said to be carcinogenic, but when put in perspective with chemicals in our daily diets , it does not to be so bad. For instance, the hydrazines in a helping of mushrooms are 60 times more carcinogenic than the Alar consumed in a glass of apple juice or 20 times greater than a daily peanut butter sandwich, which frequently contains aflatoxin B. Our diets contain literally millions of natural chemicals; intact it is not practical to test them all for carcinogenicity.

Animal tests and the and the Ames test have been used to evaluate cooked foods for their potential for inducing cancers; and it has been found that browed sugars or breads contains a variety of mutagens. In addition, caffeine and its close relative theobromine found in coffee, tea, cocoa, and some soft drinks may increase the risk of tumors by inhibiting DNA repair enzymes. Plants synthesize many carcinogenic or teratogenic chemicals as delense mechanism to ward off the animals that want to consume them. Examples of plants plant carcinogens include psoralen and its derivatives, which are widespread in plants and have been used as sunscreen in France; solanine and chaconine are teratogens and are found in greened potatoes. Other food that contains natural cicargens includes banana, basil, broccoli, cabbage, cauliflower, celery, horseradish, mustard turnips, and black pepper. In addition, red wines are believed to be responsible for the high incidence of stomach cancers among the French people, although red wine also seems to decrease the incidence of coronary heart disease. It seems that nothing can be consumed that does not contain mutagen!

Another big problem with American diet is the consumption of excess quantities of fats. The average American consumes 40% of her/ his calories in the form of fat. Comparisons of cancer death rates in different national populations have provided important clues to the nutrational causes of cancer. Very different types of cancers appear in the United States than appear in Japan. In United States, colon, breast, and prostate cancer are most prevalent, whereas stomach cancers are in excess in Japan. When the amount of dietary fat intake is plotted against the number of death by breast cancer, the results are striking; the more fat in the diet, the more higher the rate of breast cancer. How might fat intake cause cancer? It may be caused by rancid fat because it represents a sizable percentage of the fat are very prone to oxidation, which produces a variety of carcinogenic compounds. Another likely explanation is that may carcinogens are soluble in fats and accumulate in the fat of the animals we eat.

Not all Enzymatic Reactions Are Catalyzed by Protein

It had been a firmly established belief in biology that catalysis is reserved for proteins. However in 1989 the Nobel Prize was presented to Sidney Altman and Tomas Cech for discovering that RNA can catalyze a reaction. In respect, catalytic RNA make s a lot of sense. This is based on the old question regarding the origin of life, which comes first, enzyme that do the work of the cell or nucleic acids that carry the information required to produce the enzymes ? Nucleic acids as catalysts circumvents this problem.

Research leading to the discovery that RNA can act as a catalyst started in the 1970’s. Thomas Cech , at the university of Colorado at Boulder, was studying the excision of introns in a ribosomal RNA gene in Tetrahymena thermophila. In attempting to purify the enzyme responsible for splicing reaction, he instead found , much of his amazement , that intron could be spliced –out in the absence of any added cell extract. Much as they tried, Cech and his colleagues could not identify any protein associated with the splicing reaction,. After much work , Cech proposed that the intron sequence portion of the RNA had properties of an enzyme enabling it to break and reform phosphodiester bonds. At about the same time, Sidney Altman, who is a Professor at Yale university was studying the way tRNA molecules are processed in the cell when he and his colleagues isolated a enzymes called RNase-P, which is responsible for conversion of a precursor tRNA into the active tRNA. Much of their surprise, they found that RNase-P contained RNA in addition to protein and that RNA was an essential component of the active enzyme. This was such a foreign idea that they had difficulty publishing their findings. The following year, Altman Demonstrated the final bit of evidence establishing that RNA can act as a catalyst by showing that the RNase-P RNA submit could catalyze the cleavage of precursor tRNA into active tRNA in the absence of the protein component.

Since Cech’s and Altman’s discovery, other investigators have discovered other example of self-cleaving RNA sot catalytic RNA molecules dubbed ribozymes have either a hairpin – or hammerhead – shaped active center and a unique secondary structure allowing them to cleave other RNA molecules at specific sequences. It is possible to produce in the laboratory ribozymes that will specifically cleave my RNA molecule. These RNA catalysts may have pharmaceuticals applications. For example , a ribozyme has been designed to cleave the RNA of HIV. By placing a ribozyme in the cell all incoming virus particles that express this particular gene will have the RNA product cleaved by the ribozyme, which ,in the end would kill all invading virus particles.

Introducing DNA Safeguarding

The most recent statistics available tell a terrible story. More than 58,000 children are abducted by non-family members annually. While no one can fully guarantee your child's safety, DNA Safeguarding for children will keep you prepared should such a tragedy strike. DNA Safeguarding, in addition to traditional methods of identifying a child, is a superior way to identify and locate your child using their DNA sample. Unlike photos, your child's DNA will remain consistent throughout their lifetime.

With DNA Safeguarding, you are guaranteed that your child's DNA is properly stored under ideal conditions. Our staff is well trained in the proper storage and security of your child's DNA, ensuring the sample will be usable should an emergency occur.

For your investment of $95, you will receive the Peace of Mind that comes with protecting your child. You will also receive a handy identification card to keep in your wallet, providing you with quick and easy access to IDENTIGENE's toll-free number should an emergency arise. In addition, you will also receive a customized DNA Safeguarding certificate with your child's name and safeguarding number, ideal for storing with your child's important documents. You will receive the identification card and certificate within four weeks of sending your child's sample to Identigene.

How DNA Safeguarding works:

- Collect your child's DNA sample in the privacy of your home using the simple cotton cheek swab provided.

- Mail your DNA sample to IDENTIGENE in the envelope provided.

- Your child's DNA sample will be preserved in a secure, climate-controlled facility.

- You will receive an identification card with IDENTIGENE's toll-free number should an emergency arise.

- You will also receive a DNA Safeguarding certificate with your child's name and safeguarding number, as well as our full contact information.

DNA Safeguarding can allow your child's DNA sample to be compared against evidence samples to assist in tracking your child's location, possibly aiding in the safe return of your child.

Human Behavior : Genetics & Environment

Most individuals readily accepts that physical human characteristics such as hair color, skin color and height are controlled by genes. How ever the question of the importance of the genetic and environment all factor in the control of human psychological characteristics, such as behavior and intelligence, is more controversial. This question has a long history and is often referred to as the Nature vs Nature controversy. The question I s not whether the genotype has any effect; clearly genotype and environment both influence personality and behavior . The questions are how largely a contribution each make and which is the dominant influence. In Western society, the prevailing opinion has long been that behavior is most strongly influenced by environment. This implies that personality disorder has its cause in childhood experience. And societal influences, not in the genome. This controversy is hard to test scientifically because doing quantities genetics studies of human behavior is difficult. Large scale experiment involving controlled human mating cannot be made, nor is it possible to control the environment of human population. It is possible, however to study cases in which humans with identical genotypes are exposed to different environment by studying cases of monozygotic twins who have the same genotype in principle, all difference in behavior characteristics is for environmental influences, whereas similarities may result from genetic influences.

T.J Bouchard at the University of Minnesota performed an important twin study . Science 1979, Bouchrd has studied over 1000 pairs of monozygotic twins raised together(MZT) or raised apart (MZA). Twins participating in the study undergo over 50 hours of intelligence and psychological testing, the result suggest that genetics has large influences on intelligence and behavior. Calculation of H2 for IQ, for example suggest that more than 70% of the variance in IQ can be traced to genetics. Comparing MZA with MZT suggest that being reared together actually has only a minor effect on IQ . The together ness factor was more pronounced in childhood and early adolescence but declined greatly during adulthood.

Some of the most interesting result came from test measuring personality and behavior characteristics. For Characteristics such as aptitude , leisure time activities and vocational interest the twins showed a strong genetic influence, as largely as for IQ. No aspect of behavior was unaffected . Overall ,the genetics influence on all behavioral characteristics was been 50 and 70%. Major personality disorder (manic depression) also have significant genetic basis.

Individual study cases cannot be the basis for a strong conclusion. But taken together , the many cases suggest that genotypic differences may account for many, or even a majority of, the difference in behavior between individuals in human populations, including behaviors normally assumes to be under conscious control. It is becoming clear that the brain ,like other organs of the body , is strongly influenced by the genotype, and these influences may shape our behavior to a much greater extent than was previously believed.

Virtual Colonoscopy

Virtual Colonoscopy is a new method that permits doctors to look at the bowel (colon) to detect polyps and cancers. Polyps are small abnormal growths in the colon that can become cancerous if they are not removed. Virtual Colonoscopy is a recently developed method that uses a CT scanner and computer virtual reality software to examine inside the body without having to insert a long tube (Conventional Colonoscopy) into the colon or without having to fill the colon with liquid barium (Barium Enema).

• Procedure
  

While preparations for virtual colonoscopy, the patient will usually be asked to take laxatives or other oral agents at home the day before the procedure to clear the colon.

VC is done in the radiology department of medical center. The examination takes place within 10 minutes and does not require sedatives. During the procedure,

• The patient is placed in a supine position on the table
• A thin tube is inserted into the rectum, so that air can be pumped through the tube in order to inflate the colon for better vision.
• The table moves into the scanner to produce a series of two-dimensional cross-sections along the length of the colon. A computer puts these images together to create a three-dimensional picture that can be viewed on the screen.
• The patient is told to hold his/her breath during the scan to avoid distortion on the images.
• The scan is then repeated with the patient in a prone position.

After the examination, the images produced by the scanner must be converted into a 3D image. A radiologist sorts the results to identify any disorder.

The patient may get back to normal activity after the procedure, but if abnormalities are found and the patient needs conventional colonoscopy.

• Advantages
  

VC is comfortable than conventional colonoscopy for some patients because there is no use of a colonoscope. Consequently, no sedation is needed, and the patient can return to his/her usual activities or go home after the procedure without any aid. VC provides more detailed images than an x-ray using a barium enema, sometimes called a lower gastrointestinal (GI) series. Also it takes less time than either a conventional colonoscopy.

• Disadvantages

The main disadvantage to VC is cost. Another disadvantage is that a radiologist cannot take tissue samples or remove polyps during this process, so a conventional colonoscopy must be performed if lesions are found. In addition, VC does not show as much detail as a conventional colonoscopy, so cancerous cells smaller than 2 millimeters in diameter may not show up on the images. Virtual Colonoscopy done with CT exposes the patient to ionizing radiation; however some research has demonstrated that low dose VC can also be as effective in demonstrating colon and bowel disease due to the great difference in x-ray absorption between air and the tissue making the inner wall of the colon.

• People who should be screened for colorectal cancer
  
  Currently, it's suggested that people of 50 years and older should be screened for colorectal cancer. If there's a tendency towards colon cancer in the family, it's advised to start 10 years earlier than 50 and to use a more sensitive and specific technique. But for the general population, this limit is 50 years and older.

• People over the age of 50 who get screened by this processes
  
  The unfortunate thing is colorectal cancer should largely be a preventable illness, but in the United States at this time only 30 to 40 percent of people who ought to be screened have actually been screened. That gives us a lot of foundations to make up.

• Available screening methods for detection of colon cancer
  
  While there is always new for technological improvements, we need to improve the current screening technologies. Despite their drawbacks, they have been proven effective in reducing the burden of disease. There are five regimens that are currently suggested, providing practitioners and patients with a menu of options. They include annual fecal occult blood testing (FOBT) - that is, looking for blood in the stool; sigmoidoscopy every five years; colonoscopy every 10 years; air-contrast barium enema every five years; and a combination of FOBT with flexible sigmoidoscopy, each at their usual intervals.

Each of these tests have various advantages and disadvantages; for instance, they differ in sensitivity and specificity -- that is, how well they detect colon cancer or polyps when they're present and reassure us when they're absent. Colon cancer is the end-result of a prolonged process during which changes in genes in the cells lining the intestine accumulate, resulting in abnormal growth of cells. If polyps gather additional genetic changes, a part of them may become cancerous. We are worry about polyps becoming cancerous as they grow; for instance, polyps greater than one centimeter in diameter are usually removed because they present a high cancer risk.

• Reasons that prevent people to be screened
  
  There are many reasons why people aren't screened. Many people don’t recognize whether they should be screened or not. Do they know the current screening guidelines? If not, has colorectal cancer screening been recommended to them by their health care centers? Unfortunately, some recent surveys suggest that colorectal cancer screening is not usually recommended by health care centers, despite evidence of its benefit. Luckily, colon cancer screening and colonoscopy is now paid by Medicare, so cost is not as big a deal as it has been in the past.

• Optical colonoscopy considered the "gold standard" for colorectal cancer screening
  
  Colonoscopy is taken as the gold standard for colorectal cancer screening by some groups but not by others. Some radiologists recommend colonoscopy as a preferred approach to colorectal screening. However, optical colonoscopy is considered the gold standard by some professionals because it permits complete visualization of the entire colon, hence providing the opportunity to identify precancerous polyps and cancer, and then to do diagnostic biopsies or therapeutic removal of these lesions, as soon as possible.

Cancer?

Cancer is a Latin word meaning crab or creeping ulcer.

The human body consists of about 3 trillion cells, the body’s tiny building blocks seen only under a microscope. In the middle of each cell is a structure, the nucleus, which is full of deoxyribonucleic acid (DNA), and contains about 100,000 genes which control every activity of the cell. Damage to DNA, for example by tobacco or other harmful substances, can lead to a normal cell becoming cancerous. The cells are bound together by connective tissue to form a variety of organs, such as the skin, heart, lung or liver, together making up the body. Each tissue and organ has cells which have their individual shapes, structures and functions to fulfill. Every cell has a regular lifespan in every organ; it then dies and is replaced by the division of young cells. The body controls the death of old cells and the birth of new cells.

Causes of cancer

There are numerous causes of cancer a few are listed below

• Growing older
• Tobacco
• Sunlight
• Ionizing radiation
• Certain chemicals & other substances
• Some viruses & bacteria
• Certain hormones
• Family history of cancer
• Alcohol
• Poor diet, lack of physical activity or being overweight


• Growing older

The most important risk factor for cancer is growing older. Most cancers occur in people over age of 65. but people of all ages, including children, can get cancer, too.

• Tobacco

Tobacco use is the most preventable cause of death. Each year, more than 180,000 Americans die from cancer that is related to tobacco use.

Using tobacco products or regularly being around tobacco smoke (environmental or secondhand smoke) increases the risk of cancer.

Smokers are more likely than nonsmokers to develop cancer of lung, larynx (voice box), mouth, esophagus, bladder, kidney, throat, stomach, pancreas, or cervix. They also are more likely to develop acute myeloid leukemia (cancer that starts in blood cells).

People who use smokeless tobacco (sniff or chewing tobacco) are at increased risk of cancer of mouth.

• Sunlight

Ultraviolet (UV) radiation comes from the sun, sunlamps, and tanning booths. It causes early aging of the skin and skin damage that can lead to skin cancer.

• Ionizing radiation

Ionizing radiation can cause cell damage that leads to cancer. This kind of radiation comes from rays that enter the earth’s atmosphere from outer space, radioactive fallout, radon gas, x-rays, and other sources.

Radioactive fallout can come from accidents at nuclear power plants or from the production, testing, or use of atomic weapons. People exposed to fallout may have an increased risk of cancer, especially leukemia and cancers of the thyroid, breast, lung, and stomach

Radon is a radioactive gas that you cannot see, smell, or taste. It forms in soil and rocks. People who work in mines may be exposed to radon. In some parts of the country, radon is found in houses. People exposed to radon are at increased risk of lung cancer.

• Certain chemicals & other substances

People who have certain jobs (such as painters, construction workers, in chemical industry) have an increased risk of cancer. Many studies have shown that exposure to asbestos, benzene, benzidine, cadmium, nickel, or vinyl chloride in the work place can cause cancer.

• Some viruses and bacteria

Being infected with certain viruses or bacteria may cause the risk of developing cancer.
HUMAN PAPILLOMAVIRUSE (HPVs)
HEPATITIS B & HEPATITIS C VIRUSES
HUMAN T-CELL LEUKEMIA/LYMPHOMA VIRUS (HTLV-1)
EPSTEIN-BARR VIRUS
HELICOBACTER PYLORI
HIV
HHV8

• Certain hormones

Doctors may recommend hormones (estrogen alone or estrogen along with progestin) to help control problems (such as hot flashes, vaginal dryness, and thinning bones) that may occur during menopause. However studies show that menopausal hormone therapy can cause serious side effects. Hormones may increase the risk of breast cancer, heart attack, stroke, or blood clots

• Family history of cancer

Most cancers develop because of changes (mutations) in genes. A normal cell may become a cancer cell after series of gene changes occur. Tobacco use, certain viruses, or other factors in a person’s lifestyle of environment can cause such changes in certain types of cells.

Some gene changes that increase the risk of cancer are passed from parent to child. These changes are present at birth in all cells of the body.

It is uncommon for cancer to run in a family. However, certain types of cancer do occur more often in some families than in the rest of the population. For example melanoma and cancers of the breast. Most of the time, multiple cases of cancer in a family are just a matter of chance.

• Alcohol

Having more than two drinks each day for many years may increase the chance of developing cancers of the mouth, throat, esophagus, larynx, liver, and breast. The risk increases with the amount of alcohol that a person drinks. For most of these cancers, the risk is higher for a drinker who uses tobacco.

• Poor diet, lack of physical activity, or being overweight

People who have poor diet, do not have enough physical activity, or are overweight may be at increased risk of several types of cancer. For example, studies suggest that people whose diet is high in fat have an increased risk of cancers of colon, uterus, and prostate. Lack of physical activity and being overweight are risk factors for cancers of the breast, colon, esophagus, kidney, and uterus

Cancer prevention

Prevention is defined as the reduction of cancer mortality via reduction in the incidence of cancer. This can be accomplished by avoiding a carcinogen or altering its metabolism; pursuing lifestyle or dietary practices that modify cancer causing factors or genetic predispositions; and/or medical intervention (chemoprevention) to successfully reverse preneoplastic changes.
What you eat and drink, how you live, where you work….all these factors can affect your risk for cancer. Some factors related to cancer prevention are

• Tobacco and cancer
• Sun safety
• Food and fitness
• Environmental carcinogens
• School health
• Prevention & Detection Programs

• Smoking is preventable cause of cancer in our society. We can make people aware of its disadvantages by public services or individual efforts.

• The sun’s UV rays cause the vast majority of skin cancer including melanoma, which can be life threatening. The sun burn will fade, but damage to deeper layers of skin remains and can eventually cause cancer. That’s why sun-safe habits should begin in childhood and a lifetime.

• Your diet can affect your risk for cancer. Eating right, being active, and maintaining a healthy weight are important ways to reduce your risk of cancer-as well as heart disease and diabetes. You should cook smart, take control of your weight, and should have fruits and vegetables in your diet.

• Environmental factors can include smoking, diet, sun exposure, and infectious diseases, as well as chemicals and radiation in our homes and work places. Environmental carcinogens include air pollutants, medical treatments, radiations, chemicals, and consumer products.

• School health isn’t just about what’s taught in the classroom. It’s about creating policies and programs that promote a healthy school environment, thereby reinforcing healthful living. It’s about reinforcing healthy habits every day and every year that kids are in school.

• Prevention and detection programs like ACS (American Cancer Society) help educate you about cancer risks, early detection methods, and prevention.

Cancer therapies

Animal studies have already contributed to the development of a drug that has been described by some as “the vanguard in a new generation of cancer drugs.” Gleevec, a chemotherapy that works by inhibiting a protein that contributes to cancer cell growth, is the first effective treatment for people with chronic myeloid leukemia, Gleevec was developed using cell cultures and mouse studies. Like the research programs devoted to developing a malaria vaccine and treatments for epilepsy and heart disease, cancer research requires the use of many different models. Cell and tissue culture, whole animal models, and clinical (human) studies help scientists better understand both the cause of various diseases and better ways to prevent, treat and possibly cure them. All of these methods were used
in the development of Gleevec. In order to develop a new drug to treat a disease, it is necessary to make use of all of these models. Culture, animal, and human studies each play an important role in the struggle to understand disease and develop cures.

GLEEVEC - A drug that is highly effective in treating chronic myeloid leukemia. Although it took more than a decade of laboratory work to develop Gleevec, the drug gained FDA approval in less than 3 years. Typically, it takes 14 years to win FDA approval by proving that a new drug is safe and effective through clinical trials.

CHEMOTHERAPY-Treatment of a disease with a chemical that has a toxic effect on cancerous tissue (anticancer therapy) or on a disease-producing germ (antibiotic)

A Reader's Toolbox

Women should take a lot of care of the sensitive parts of their body like eyes, perfect breasts and teeth etc. As the health of the child depends on the health of the mother so extra care must be taken to improve it. Women should always take healthy foods to ensure perfect nutrition. Women should go for routine checkup of their complete body so that they can find out any internal changes like breast cancer symptoms or any other malfunctioning of the body as well.

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Science2Day forum

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Effective Learning!

learning essentially has 3 steps. encoding, storing and decoding or retrieving.

Encoding - understanding information that you receive and transform them in to understandable format.

Storing - Most of the information we come across everyday doesn't get into our long term memory. But those information we use consciously for some time will leak into our long term memory.

Initially all information that we come across is stored in our short term memory. Then depending on the significance of the information, how long the information was used consciously and other factors, the information will be stored or will left over. Those factors will also decide how easy those memories can be retrieved.

Retrieve / Decode - Retrieving memory form where we stored.

I just wanted to give a brief overview of the processes involved in learning. Now we'll discuss, how you can use these theories practically to improve your learning.

You can use these easy to use methods. There are two methods that i recommend you to use.

1. SQ3R
2. MURDER

• SQ3R

Survey - Before you start studying a particular section, go through it on the surface and try to get a picture of what you are going to learn

Questions - Try to make some question that you expect to get answered by studying that particular section.

Read - Read the section carefully (This should be a very cognitive process) and try to understand the concepts.

Recite - Try to read out what you have read with out looking at the text. Even if the theory suggest this step, i don't recommend this for science and math students. But you can use this to test your memory on certain formulas and so on.

Review - Although all the steps are important, i find this step very very important. This is the step which require lot of concentration. In this step you have to re memorise and check your understanding of certain principals and concepts. Also you can apply what you just learnt to real world examples and check your understanding. Doing problems from the lesson will fall into this category.

MURDER is a very similar technique. It also use the same principals as SQ3R.

Microscopic Urine Analysis!

In this test, urine is centrifuged at relatively low speed (about 2-3,000 rpm) for 5-10 minutes so the solid materials sediment at the bottom. The sediment is spread on a slide and looked at under a microscope.

Red or white blood cells.

Blood cells are not found in urine normally. Inflammation, disease, or injury to the kidneys, ureters, bladder, or urethra can cause blood in urine. Strenuous exercise, such as running a marathon, can also cause blood in the urine. White blood cells may be a sign of infection or kidney disease.

Casts.

Some types of kidney disease can cause plugs of material (called casts) to form in kidneys (in the distal convoluted tubule (DCT) or the collecting duct ). The casts then get flushed out in the urine. Casts can be made of red or white blood cells, waxy or fatty substances (mucus), or protein. The type of cast in the urine can help show what type of kidney disease may be present.

Hyaline Cast

Red Cell Casts

Crystals.

Healthy people often have only a few crystals in their urine. A large number of crystals, or certain types of crystals, may mean kidney stones are present or there is a problem with body metabolism.

Oxalate Crystals

Bacteria, yeast cells, or parasites.

There are no bacteria, yeast cells, or parasites in urine normally.

wow!!

Medical Ethics

Two theories used to decide the rightness of an actions (whether the action is morally correct)  

Teleological theory

• rightness of action is determined by the consequence of the action.

• so we have to wait until the consequences are apparent.

• but there are problems in determining whether the consequences are good or bad (in some situations). So people have proposed various theories to measure the goodness and the badness of actual consequence.

• the end justify the means

Deontological theory

• rightness of action is determined by the action it self.

• don't have to wait until the consequences are apparent.

• Persons action should confirm to the specific moral duty of that person at the given moment. But there can be disputes of what is the actual moral duty of a person.

• since this theory doesn't take in to consideration the consequences, the consequences of a moral act defined by this theory can be suffering or painful.

• the end does not justify the means

Common European Language

The European Commission has just announced an agreement whereby English

will be the official language of the European Union rather than German,
which was the other possibility.

As part of the negotiations, the British Government conceded that
English spelling had some room for improvement and has accepted a 5-
year phase-in plan that would become known as "Euro-English" .

In the first year, "s" will replace the soft "c". Sertainly, this will
make the sivil servants jump with joy. The hard "c" will be dropped in
favour of "k". This should klear up konfusion, and keyboards kanhave one
less letter.
There will be growing publik enthusiasm in the sekond year when the
troublesome "ph" will be replaced with "f". This will make words like
fotograf 20% shorter.

In the 3rd year, publik akseptanse of the new spelling kan be expekted
to reach the stage where! more komplikated changes are possible.

Governments will enkourage the removal of double letters which have
always ben a deterent to akurate speling.

Also, al wil agre that the horibl mes of the silent "e" in the languag
is disgrasful and it should go away.

By the 4th yer people wil be reseptiv to steps such as replasing "th"
with "z" and "w" with "v".

During ze fifz yer, ze unesesary "o" kan be dropd from vords kontaining
"ou" and after ziz fifz yer, ve vil hav a reil sensi bl riten styl.

Zer vil be no mor trubl or difikultis and evrivun vil find it ezi tu
understand ech oza. Ze drem of a united urop vil finali kum tru.

Und efter ze fifz yer, ve vil al be speking German like zey vunted in ze
forst plas.

If zis mad you smil, pleas pas on to oza pepl.

Amazing !!!!!