RNA Virus

RNA Virus

During the process of DNA replication, errors occasionally occur in the polymerization of the second strand. These errors, called mutations, can have an impact on the phenotype of an organism, especially if they occur within the protein coding sequence of a gene. Error rates are usually very low 1 error in every 10–100 million bases—due to the "proofreading" ability of DNA polymerases.(Without proofreading error rates are a thousand-fold higher; because many viruses rely on DNA and RNA polymerases that lack proofreading ability, they experience higher mutation rates.) Processes that increase the rate of changes in DNA are called mutagenic: mutagenic chemicals promote errors in DNA replication, often by interfering with the structure of base-pairing, while UV radiation induces mutations by causing damage to the DNA structure.Chemical damage to DNA occurs naturally as well, and cells use DNA repair mechanisms to repair mismatches and breaks in DNA—nevertheless, the repair sometimes fails to return the DNA to its original sequence.

In organisms that use chromosomal crossover to exchange DNA and recombine genes, errors in alignment during meiosis can also cause mutations. Errors in crossover are especially likely when similar sequences cause partner chromosomes to adopt a mistaken alignment; this makes some regions in genomes more prone to mutating in this way. These errors create large structural changes in DNA sequence—duplications, inversions or deletions of entire regions, or the accidental exchanging of whole parts between different chromosomes (called translocation).

Treatment for Brain Tumour

Treatment for Brain Tumour



The treatment of human brain tumors rarely. By type and stage of cancer, patients can be treated with surgery, radiation therapy or chemotherapy. Some patients receiving combination therapy.

No version "at any stage of disease, patients may receive treatment to control pain and other symptoms of cancer, reduce the side effects of treatment, and any emotional problems. Thats kind of treatment is called symptom management, supportive care, or palliative treatment.

Doctor is the best person to describe treatment options and discuss the expected results.

Patient may want to talk about the doctors involved in clinical trials, it is a study, to learn a new way of treatment. The Department of "commitment to research Zell" for more information about clinical tryals.

Surgery is the most common treatment for brain tumors. Surgery to open the skull is known as kranyotomi. This is done under general anesthesia. Before the surgery began, the scalp shaved.Then the surgeon makes an pitche open and use a special kind of discovery, removal of a skull bone. Removal of some or all of the tumor, the surgeon James's opening in the skull bone plates or a metal or cloth. Surgeon and then close the incision in the scalp.
Radiotherapy

Radiation therapy (also known as radyotherapi) using high - high-energy rays to kill tumor cells.Radiation can be from X - rays, gamma rays, or protons. A huge machine Ames Radiation Oncology and organizations close to it. When it direkted of radiation in the brain or spinal cord.

Radiation therapy usually follows surgery. Of radiation to kill cancer cells can remain in place. In the past, patients did not have radiation therapy instead of surgery.

Patients in hospital or clinic for radiation therapy. The plan of treatment depends on the type and size of tumor and age of the patient. Each treatment lasted just minutes.

Doctor to make the step to protect surrounding healthy tissue tumors of the brain:

Fraktyonatyon - radyatyon usually to determine the treatment five days a week for several weeks. To provide a total dose of radiation over an extended time by half, to protect healthy tissue tumors in the region.

Hiperfraktyonatyon - Davis radiation small idol of patients two or three times a day, rather than a larger amount of time.

Stereotaktik radiotherapy - a narrow-beam radiation direkted lungs from different angles.Technique, patients wear the top of the strict structure. A wrong card or scan images to create the exact location of the tumor. Doctors use a computer to determine the necessary dose of radiation, as well as south and the angle of radiation beam. During the treatment, we can identify a single visit, or a few visits.

3 - Three-dimensional radiation therapy konformal - a computer creates a 3 - three-dimensional images, lungs and surrounding brain tissue. A type of medical purpose of the exact shape of the beam of radiation oncology. To accurately focus radiation beams defensive in normal brain tissue.

Proton beam radiation therapy - the source of the proton radiation, instead of X - ray. Dr. Ames proton beam cancer. Protons through healthy tissue without compromising it.
Tshemotherapi

Tshemotherapi, using drugs to kill cancer cells, is sometimes used to treat brain tumors. Drugs will decide either orally or through the injection. Either way, the drugs enter the blood circulation and the passage of the body. The drug is usually to return to the moon is as follows for each hour of treatment.

Tshemotherapi may determine the out-patient of the hospital, doctor's office or home. Rareli, patients may need to stay in hospital.

Children more likely than adults to chemotherapy. However, the elderly can have post-operative chemotherapy and radiotherapy.

For some patients with brain cancer, surgeons remove some chip implanted and tumors containing chemotherapy. Each woman is about the size of a dime. In the past few weeks, the chip is dissolved, the release of drugs to the brain. The drug can kill cancer cells.

Transgenic plants

Transgenic plants 

 

Transgenic plants plants created by introducing genes from other species through genetic engineering. These systems are usually developed to produce certain desirable characteristics such as resistance to disease, parasites and resistance to herbicides and resistance to certain environmental conditions. To know the transgenic plants and the risks and benefits, read on.
A transgenic organism is the term used to describe a type of genetically modified organism whose genetic material is manipulated to produce changes in the body with the leg you want. To achieve this objective, the genetic material or DNA of an organism is injected in the nucleus of cells play another agency in the same or different, in order to produce or transport suddenly desirable. This technique of creating transgenic organisms is called recombinant DNA. In other words, transgenic organisms are organisms with a single gene or genes transferred from another organism of the same or different species in the laboratory using the technology of recombinant DNA. This technique can be done in both plants and animals to create transgenic plants and animals.

Transgenic plants Appointment

Transgenic plants are plants that are created by introducing genetic material from a different species, using genetic engineering to produce plants with specific characteristics. The genes of different species can be introduced into a plant in several ways. In general, it is easier to produce transgenic plants compared with transgenic animals. In plants, there is no difference between somatic and germ cells and therefore the genes can be introduced into somatic cells and tissues to produce transgenic plants.

In the past, new plant varieties containing genes from two species generated through hybridization or cross. However, the breeding took place between two closely related species. However, modern biotechnology and genetic engineering, integration of genetic material not only connected but also of exotic species to create transgenic plants and genetically modified. Bt corn, Bt cotton and golden rice are just some of the most common examples of transgenic plants created in this way.

Pros and cons of transgenic plants

Production of transgenic plants and the introduction of foreign genetic material is extremely doubtful. A range of benefits and risks of production of these plants have been identified by scientific studies. One of the main advantages of transgenic plants and crops by the introduction of some parts as you want, resistance to diseases, pests and herbicides. This in turn can increase crop yields to meet rising demand for food. Another advantage is that with the help of genetic engineering, it is possible to produce plants that can tolerate adverse environmental conditions such as drought and cold. Even the floor laden with large quantities of salt can be made with the production of genetically modified crops that can grow in saline soils.

All these advantages will ultimately benefit the agricultural sector. With the growing concern about the environmental impacts of using large-scale insecticides and pesticides is very important to reduce the use of these substances. Transgenic plants resistant to pesticides may play an important role in reducing the use of these chemicals. Plant varieties resistant to herbicides can reduce the negative effects of herbicides and the development of transgenic plants resistant to insects can help reduce the total amount of pesticides used. This, in turn, can improve environmental quality. Besides this, some transgenic plants can produce higher levels of nutrients that can improve the nutritional quality of food.

Despite these advantages, the development of genetically modified or altered are widely criticized, particularly by the fact that these plants have a negative impact on the environment, ecosystem and biodiversity. Many also expressed concern that the genetic material of transgenic plants can be transferred to non-GM plant varieties. Although herbicide-resistant transgenic plants, the same quality, if transferred to weeds can make it very difficult to control weeds. Apart from these, it was found that some genetically modified foods, developed by the animals to cause allergic reactions in some individuals. However, no incidence of these severe allergies have been reported in case of manufacture of food for human consumption.

Another issue raised by critics of GM crops is that these plants can release genes of antibiotic resistance in soil, which can cause soil micro-organisms resistant to antibiotics. Apart from these, laboratory studies have suggested that the introduction of genetically modified crops may affect other organisms. How, for example, Bt corn pollen can affect the larvae of monarch butterflies and moths, if they feed on the leaves of the plant milkweed, covered with pollen from maize Bt, but the supporters of GM and GM crops have refuted the claim this and claims that Bt corn pollen on milkweed leaves can reach a high level of concentration to produce such effects. Learn more about

* The investigation of DNA
* Genetically Modified Foods: Benefits and Risks

Briefly, transgenic plants, risks to human health and ecosystems is a controversial issue. Therefore, further detailed studies and investigations to resolve disputes related to transgenic plants, so that consumers can discover the truth about these plants and genetically modified foods. Apart from these, there are many ethical issues are also associated with transgenesis, which must also be adequately addressed.

What are the symptoms of brain tumor?

 What are the symptoms of brain tumor?
Symptoms of brain tumors depend on tumor size, type and location. Symptoms can cause nerve damage or certain parts of the tumor presses on the brain. May they also lead to brain swelling or fluid in the skull when.

This is the most common symptoms of brain tumors:

Headaches (usually worse in the morning)
Nausea or vomiting

Change, language, vision or hearing
Or on foot balance

Changes in mood, personality or ability to concentrate

Memory Problems

Muscle twitching or seizures (epilepsy or convulsions)

Numbness or tingling in hands and feet
These symptoms are a sure sign of brain tumor. Other conditions can also cause these problems. People experiencing these symptoms occur, it should be noted that the treatment as soon as possible. Only doctors can diagnose and treat the problem.

Origin Of Life In RNA? Study Suggests Genetic Molecules May Have Self-Assembled

Origin Of Life In RNA? Study Suggests Genetic Molecules May Have Self-Assembled

 A pair of RNA-like molecules can spontaneously assemble into gene-length chains, chemists in the United States and Spain report. Billions of years ago, related molecules may have created a rudimentary form of genetic information that eventually led to the evolution of RNA and life itself, the researchers say. Although it's likely to be difficult, if not impossible, to prove whether similar proto-RNAs were present at the dawn of life, the researchers are working to see if the proto-RNAs can indeed faithfully encode information and evolve toward RNA.

Origin of life researchers have long thought that RNA, the molecular cousin of the DNA that encodes our genes, may have played a starring role in the initial evolution of life from a soup of organic molecules. RNA has a simpler structure than DNA and is a more adept chemical catalyst. So it would seem that RNA-based life might arise more readily than DNA-based life.

But there are problems with this so-called RNA World hypothesis. For starters, in water, the four chemical components of RNA—the nucleotides abbreviated A, G, C, and U—don't spontaneously assemble to create sizable molecules. So it remains a mystery how the first long gene-length chains of RNA could have taken shape in Earth's ancient oceans. This and other conundrums have led many to believe that RNA may itself be the product of early molecular evolution, and that proto-RNAs arose first and eventually gave way to RNA. "RNA is so perfect today that it has to be the product of evolution," says Nicholas Hud, a chemist at the Georgia Institute of Technology (Georgia Tech) in Atlanta.

rna lifeChemicals known as TAPAS and CA (left) assemble together forming rosettes (middle) that then stack into genelike chains (right).

Researchers have toyed with the idea of proto-RNA for decades and even come up with potential chemical candidates. One such set of proto-RNAs involves two chemicals called cyanuric acid (CA) and triaminopyrimidine (TAP). TAP comes from a family of compounds known as pyrimidines, as do the RNA bases C and U. CA, meanwhile, is a close pyrimidine relative. Previous research had shown that when CA and TAP were put in an organic solvent, groups of three CAs and three TAPs would spontaneously form ringlike structures called rosettes. These rosettes would then stack atop one another to form long chains.

Unfortunately, in water CA and TAP clump together in large ribbons and sheets and quickly fall out of solution, making it hard to conceive of how these proto-RNAs could have stored genetic information in the earliest stages of life.

Now, however, Hud and his colleagues at Georgia Tech and the Institute for Research in Biomedicine in Barcelona, Spain, have solved this solvent problem. The researchers gave TAP a short chemical tail, transforming it into a chemical they call TAPAS, as they reported on Friday in the Journal of the American Chemical Society. And that one change encourages it to assemble with CA to form rosettes in water. What is more, the rosettes stack atop one another, forming long genelike chains made up of as many as 18,000 individual TAPAS and CA components—quite a stack of small plates.

"The nice thing [about the current study] is this is a demonstration of self-assembly in water," says Ramanarayanan Krishnamurthy, an origin of life chemist at the Scripps Research Institute in San Diego, California. "That is a step in the right direction."

The next step, Hud says, will be to see whether this two-component assembly can be made to encode information like a primitive gene and to evolve toward the structure of RNA. If so, that still won't settle the debate as to whether CA and TAPAS gave life its start. But it will suggest one plausible chemical route to life's origin.