понедельник, 22 октября 2012 г.
Scientists study "garbage DNA" the person
The most part of a human genome is presented so-called to "garbage DNA" - free scraps of a genetic code. The last researches of the international scientific group showed that the essential part of this material is formed by DNA of various viruses.
Under the direction of the professor of biology of Cedric Feskotta from the Texas university the group of scientists of the USA and Japan found out that in a genome of the person and some mammals of a chain of DNA contain inserts of a virus of Born, replication and which transmission can occur in cellular kernels. Together with the Japanese colleague professor Keyzi Tomonaga from University of Osaka, Feskott assumes that similar impregnations are at the bottom of schizophrenia and other mental diseases of the person.
Born's virus received the name on the German city where in 1885 epidemic caused by it was fixed. This form энцефаломиелита almost completely exterminated horses of Prussian army, having turned its cavalry into infantry. Carriers of a virus of Born (BDV) are birds and house mammals, however long time was considered that this infection isn't dangerous to the person.
Only in 1996 the American physicians proved that Born's illness affects also people. Suffering this disease are subject to a constant depression, have memory problems, and also violation of perception of the outside world. Born's virus is in own way unique - his RNA sequence strikes only brain neurons, creating the permanent center of an infection in the carrier head.
Then the Taiwan geneticists showed that in families of the people struck with a virus of Born, the percent of patients with schizophrenia and other mental disorders is great. Now new research allowed to establish that the dangerous disease leaves the trace in a genome of the person, as provokes emergence of mental deviations in the subsequent generations.
Having investigated 234 enkriotichesky genomes (that is a genome which managed to be deciphered completely), Feskott and his colleagues found BDV signs in many mammals. Besides, geneticists found the mechanism allowing these RNA elements of a virus of Born to take root into chromosomes of the person, transferred this disease that conducts to the subsequent mutations of a nervous cage.
EKO increases risk of developmental anomalies at a fruit
Children conceived as a result of ekstrakorporalny fertilisation (EKO), have considerably bigger risk to be born with congenital defects in comparison with conceived by a natural way. In particular it concerns organs of vision, cardiovascular and urinogenital systems.
Such data, ScienceDaily reports, are provided in work of experts from university of the State of California (Los Angeles), presented on October 20 at national conference of the American academy of pediatrics (AAP) passing in New Orleans. Authors of research made the conclusions on the basis of data on 50 820 children who were born in California - the state of the USA where EKO application - in 2006-2007 is especially widespread. 46 025 from them were conceived by a natural way, and 4795 - by means of EKO. At collection of information the age and racial accessory of mother, total of childbirth at it, use of various auxiliary reproductive techniques by it, including medicinal stimulation of an ovulation, and also date of birth and a sex of the child, a way of its conception and presence of developmental anomalies were considered. For research children with approximately close parent demographic data were selected.
As a result it was established that with various congenital defects 3 463 children were born. The comparative statistical analysis showed that among conceived by means of EKO developmental anomalies meet considerably more often than at conceived in the usual way - 9 percent against 6,6 percent. And in particular this overweight concerns organs of vision - 0,3 percent against 0,2 percent, hearts - 5 percent against 3 percent and urinogenital system - 1,5 percent against 1 percent. In total the probability of congenital developmental anomalies at "children from a test tube" appeared in 1,25 times higher, than at "heteros".
As it is noted in the report, so obvious interrelation between congenital defects and application of reproductive technologies is revealed only for EKO, for other techniques promoting a fertilnost some appreciable results weren't received. The reasons of such phenomenon aren't studied yet.
According to the data sounded in July, 2012 on the 28th annual congress of ESHRE (The European society on problems of a reproduction of the person and an embriologiya), since July, 1978 in the world, at least, five million "children from a test tube" were born. Among world regions in which reproductive technologies are actively applied, Europe, and among the countries - the USA and Japan is in the lead.
The experimental technique of treatment of infertility - ekstrakorporalny fertilisation - was developed by the British doctors Robert Edwards (Robert Edwards) and Patrick Steptou (Patric Steptoe). Louise Brown who was born on July 25, 1978 became the first child, born thanks to this procedure. Now procedures of auxiliary reproductive technologies include, besides EKO, an intratsitoplazmatichesky injection of a spermatozoon in an oocyte (IKSI), and also some other techniques.
воскресенье, 23 сентября 2012 г.
Stem cells don't restore heart at adults
These researches of scientists from Kornelsky university and university of Bonn say that stem cells and in the truth can replace dead fabrics of heart after heart attack at early age, but the same cages lose this regenerative ability at adults.
Research which led on mice, showed that not differentiated cages predecessors promote creation of new cells of heart at two-day mice, but not at adult individuals, having settled long-term dispute that stem cells can play a part in restoration of heart of an adult mammal after a heart attack in which because of blocking of an artery heart fabrics perish.
«But existence of these cages at adults remains disputable if adults have quite capable stem cells why after a heart attack there are no new cages? Whether it in the absence of stem cells or something special in a heart attack which ингибирует stem cells in formation of new cells of heart, remains a question in which we decided to be engaged, using that newborn mice have same cages», the leading author of work Michael Kotlikoff declared.
Kotlikoff and his colleagues found out that at two-day mice new cells of heart were created and almost completely recovered from a heart attack, proving that the trauma doesn't interfere with stem cells in creation of new cells of heart. The same procedure was carried out on adult mice, but there any new cells of heart wasn't formed, confirming that adult individuals have no necessary stem cells for creation of new cells of heart which are called миоцитами while new cages of blood vessels continued to be formed.
The stem cells found in heart of adult individuals «lost possibility to become cells of heart, and are capable to form only new vessels», Kotlikoff speaks. Unary stem cells are differentiated in all fabrics at the beginning of life, but eventually these cages become "intellectually limited" or specializes in formation of only a certain fabric.
Scientists confirmed existence of cancer stem cells
Three independent groups of scientists at the same time reported about detection of so-called cancer stem cells - small groups of cages on which growth of cancer tumors depends, transfers to Lenta. Ru. Allocation of such cages changes not only idea of the mechanism of development of malignant new growths, but also an approach to their treatment. On August 1 three works devoted to this subject, are published in Nature and Science magazines.
Thus, the hypothesis is confirmed that at the heart of ability of cancer tumors to renew the growth after long remission existence of small group of cages lies, which can "wait" in a sleeping condition action and chemotherapy, and beam therapy to begin then active division and to start the same process at other types of cancer cages, having initiated repeated development of a disease.
The first assumptions of existence of such catalyst and, respectively, to the hierarchical nature of growth of cancer cages appeared in the 1990th years during research of development of leukemia at mice, but they still weren't confirmed on an example of the malignant tumors developing in various fabrics of an organism.
All groups of the researchers who have reported about the opening to trace processes occurring in tumors and how various types of cages are involved in them, used methods of genetic marking. Thus each of groups had objects of studying the.
So, the team under the direction of biologist Luis Parada (Luis Parada) from the Southwest Medical center at university of the State of Texas in Dallas, whose work is published in Nature, concentrated on глиобластоме - one of types of cancer tumors of a brain. They assumed that the genetic markers inherent in healthy adult neural stem cells, can be similar to markers of stem cells глиобластомы. Being based on this assumption, authors really found tumors some cages with such markers, thus, that other cages of a tumor didn't contain them.
Further researches showed that under the influence of standard chemotherapy all cages, except marked then growth of a tumor renews perish, thus marked cages generate all the others. When authors managed to suppress process of division of marked cages, the tumor actually broke up to fragments which didn't become a basis for development new glioblasty.
The group under the direction of Cedric Blanpen (Cedric Blanpain) from the Belgian Free university of Brussels, whose work is also published in Nature, was engaged in studying of a cancer of skin, and all cages of a tumor became objects of research. They managed to find out that cancer cages differ according to the division scenario - the part from them can share limited number of times, and a part, and these are those stem cells - infinitely. It appeared that in that case when the cancer becomes aggressive, in a tumor stem cells capable to unlimited division, instead of cages of other type are formed generally. According to Blanpen, this opening can become a key to new strategy of a cancer therapy at early stages - instead of removal of stem cells, their transformation by means of therapeutic influence in other type of cages with limited ability to division.
Scientists grew up a human liver from stem cells
At the International conference on research of stem cells in Yokohama Japanese scientists presented results of development of innovative technology on creation of an artificial liver.
Scientists from university of Yokohama (Yokohama City University) grew up a human liver from stem cells. However, to replace it to the patient yet it will not be possible. First, the received structure too small – only about five millimeters in diameter, and secondly, it was grown up in the head of an experimental mouse.
Besides, the body which has been grown up by Hideki of Taniguti and Takanori Takebe, still it is necessary to check on "professional suitability", that is, whether it carries out necessary functions. Nevertheless, already now many experts call work of Japanese as break in transplantology.
In the work scientists used the induced plyuripotentny stem cells which were programmed" on transformation into cells of a liver. In addition scientists added cages germinal connecting a fabric — mesenchymas and cages from umbilical cord blood.
«We mixed some types of cages, and they independently gathered to structures almost identical to fabrics of a human liver. Ourselves were surprised!. Later researchers replaced the received structures in a skull of live mice with a heavy immunodeficiency. Plentiful inflow of blood to a brain of small animals promoted the strengthened growth of new body, and the weakened immunity couldn't cause rejection brought from the outside of fabrics» — Takebe told.
In 48 hours of a cage began to be formed in a tiny liver. The quantity and structure of a glycogen and amino acids completely corresponded to human body.
«The liver received by us still is far from ideal — scientists speak. – We still should find a way of a reconstruction of bilious channels and increase in the sizes of body».
Japanese presented results of work at the International conference on research of stem cells in Yokohama (ISSCR 2012). For this reason the detailed description isn't published yet in reviewed magazines. Now researchers of the Country of a rising sun carry out the careful analysis of the received body to understand true value of the work.
воскресенье, 2 сентября 2012 г.
Ischemic heart trouble: prophylaxis
Ischemic heart trouble: prophylaxis
Prophylaxis of ischemic heart trouble is needed for active life and maintenance of health on long years. The prophylaxis of ИБС helps to protect Your heart. A healthy heart is a necessary condition of good feel, physical activity and valuable life.
The prophylaxis of ischemic heart trouble on the face of it is simple, but supposes constancy in Your optimization of own character of life. It be possible to say, a prophylaxis of ИБС is a regular prosecution of itself, including the revision of row of priorities and habits.
The prophylaxis of ИБС in large part is assisted by minimization of pernicious habits(in an ideal is the realized refuse). Smoking and overconsumption of alcohol negatively influence on passableness of vessels. The damaged bottled vessels are principal reason of development of ИБС.
Consumable food is an important aspect in the prophylaxis of ischemic heart trouble. Predominance of foods rich in vitamins(especially groups In and С), decline of consumption of culinary
Prophylaxis of ischemic heart trouble is needed for active life and maintenance of health on long years. The prophylaxis of ИБС helps to protect Your heart. A healthy heart is a necessary condition of good feel, physical activity and valuable life.
The prophylaxis of ИБС in large part is assisted by minimization of pernicious habits(in an ideal is the realized refuse). Smoking and overconsumption of alcohol negatively influence on passableness of vessels. The damaged bottled vessels are principal reason of development of ИБС.
Consumable food is an important aspect in the prophylaxis of ischemic heart trouble. Predominance of foods rich in vitamins(especially groups In and С), decline of consumption of culinary
Specialists taught barrel mews independently to form a retina
From the barrel mews of mise the Japanese scientists succeeded to create a retina in a laboratory, BBC reports. During an experiment specialists appealed to the barrel mews, because they are able to grow into many tissues of body. At addition of correct mixture of nutritives of mew changed and began raise, forming a retina.
Scientists hope to use this method, in order to create the inexhaustible supply of mews of retina or even valuable retinas for subsequent transplantation. An ultimate goal is constructing of separate eye. For example, it will allow to save hundreds of people from the loss of eyesight because of age-dependent макулярной
Striking, that during the work the Japanese specialists showed, as the grown barrel mews itself it was organized spontaneous character in a difficult form that reminded the developing eye of embryo. A three-dimensional, stratified structure ascended to an eye bowl - part of eyecup extended as a bowl, a retina develops from the walls of that.
Scientists hope to use this method, in order to create the inexhaustible supply of mews of retina or even valuable retinas for subsequent transplantation. An ultimate goal is constructing of separate eye. For example, it will allow to save hundreds of people from the loss of eyesight because of age-dependent макулярной
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