quarta-feira, 26 de maio de 2010

Se contaminar com micobacteria é bom para a memória!!!!!

Bactéria poderia ajudar na inteligência


SÃO PAULO – A exposição a uma determinada bactéria poderia ajudar a tornar as pessoas mais inteligentes.

Essa é a dúvida levantada por Dorothy Matthews e Susan Jenks, do The Sage Colleges in Troy, Nova York, ao apresentarem os resultados de suas pesquisas.

Leia também:
Caminho da coceira é identificado (10/08/2009)
Cafeína pode ajudar na cura do Alzheimer (08/07/2009)
O trabalho apresentado hoje no 110º Encontro Geral da Sociedade Americana de Microbiologia, em San Diego, usa como base um organismo que, acredita-se, já tenha propriedades antidepressivas.

A Mycobacterium vaccae é uma bactéria natural do solo, que as pessoas normalmente ingerem ou inalam.

Estudos anteriores mostraram que injetar bactérias mortas em ratos estimulava o crescimento de neurônios que, por sua vez, aumentavam o nível de serotonina e diminuíam a ansiedade nos animais.

Como a serotonina tem papel no aprendizado, os pesquisadores começaram a se perguntar se a bactéria viva poderia aumentar essa capacidade em ratos.

Eles alimentaram os roedores com espécimes vivos da M. vaccae e checaram sua habilidade ao atravessar um labirinto – os resultados foram comparados a ratos não alimentando com elas.

Aqueles que receberam bactérias na dieta atravessaram o labirinto duas vezes mais rápido e com menos ansiedade demonstrada que os outros.

Em um segundo experimento, as bactérias foram removidas da dieta e eles foram re-testados. Apesar de mais lentos do que antes, eles ainda estavam mais rápidos do que o grupo controle. Um teste final foi feito após 3 semanas. Apesar de ainda mais rápidos, os resultados dos ratos que comeram bactérias não foram estatisticamente satisfatório, provando que o efeito é temporário.

A pesquisa não é definitiva e apenas sugere que a M. vaccae pode ter influência na ansiedade e na capacidade de aprendizado dos mamíferos. Mas os pesquisadores declararam que isso pode sugerir que, em escolas, passar mais tempo ao ar livre pode ser bastante benéfico para as crianças – diminuindo sua ansiedade e ajudando no aprendizado.

terça-feira, 25 de maio de 2010

Como avaliar espacialmente uma infecção por micobacteriia

Detection of spatial and temporal spread of Mycobacterium avium subsp. paratuberculosis in the environment of a cattle farm through bio-aerosols

S.W.F. Eisenberga, , , M. Nielena, W. Santemaa, b, D.J. Houwersc, D. Heederikd and A.P. Koetsa, b
a Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 7, 3584 CN Utrecht, The Netherlands
b Division of Immunology, Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, The Netherlands
c Division of Clinical Infectiology, Dept of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, The Netherlands
d Institute for Risk Assessment Sciences, Utrecht University, The Netherlands
Received 27 April 2009; revised 12 November 2009; accepted 17 November 2009. Available online 3 December 2009.
Abstract
Environmental samples were collected to investigate the spatial and temporal spread of Mycobacterium avium subsp. paratuberculosis (MAP) in a dairy cattle barn before and after the introduction of two groups of MAP-shedding animals. Samples collected off the floor of the barn reflected the moment of sampling whereas samples collected by microfiber wipes at a minimal of 3 m height contained the accumulated settled dust over a 3-week period. Samples were analysed by IS900 qPCR for the presence of MAP DNA and by culture for viable MAP bacteria. MAP DNA was detected in a large number of sites both before and after introduction cattle. MAP DNA was detected inside the barn in floor and dust samples from cubicles and slatted floors and in settled dust samples located above the slatted floors and in the ventilation ridge opening. Outside the barn MAP DNA was detected by PCR in samples reflecting the walking path of the farmer despite hygiene measures. No viable MAP was detected before the introduction of shedder cattle. Three weeks later viable MAP was found inside the barn at 7/49 locations but not outside. Fifteen weeks later viable MAP was also detected in environmental samples outside the barn. In conclusion, introduction of MAP shedding cattle lead to widespread contamination of the internal and external environment of a dairy barn, including the presence of viable MAP in settled dust particles suggesting potential transmission of MAP infection through bio-aerosols.

sexta-feira, 21 de maio de 2010

tuberculose em animal silvestre e tb bovina


21 May 2010


Bovine TB found in wild boar for first time in UK


Photograph: Wildwood Trust/PA
TB has been found in feral wild boar for the first time in the UK. Photograph: Wildwood Trust/PA
James Meikle
guardian.co.uk News Fri 21 May 2010 09:40 BST
Scientists discover TB in wild boar, raising fears among farmers that boars and badgers could be contributing to disease in cattle

Scientists have found bovine TB in a feral wild boar for the first time in the UK. The discovery may raise fears among farmers that boars, along with badgers, could be contributing to bovine TB in cattle – but the researchers say the porcine species poses a low risk of spreading the disease to livestock or humans.
Tests on a 60kg female boar believed to be 7-9 months old revealed tissue lesions consistent with the disease.
The wild boar joins the growing list of wildlife hosts for TB. The threat from badgers is now judged so great that the new coalition government is preparing for England to follow Wales in culling the animals, despite conflicting scientific advice on whether the measure would be effective.
The boar died while under anaesthesia as part of an ongoing study of the animals in Herefordshire, an area where there is a high prevalence of TB on farms.
The study is being conducted for the Department for Environment, Food and Rural Affairs (Defra) by the Food and Environment Research Agency.
Boar in the wild probably became extinct in England about 300 years ago but a series of escapes and deliberate releases from farms since the 1980s have meant small feral populations have become re-established.
A letter in today's Veterinary Record says any potential role wild boar may have in spreading bovine TB in the UK remains unclear, although the disease has been found in farmed wild boar twice.
In parts of Spain and Portugal the disease in boar is already at a level that is self-sustaining but in Italy they are "spillover" hosts.
The government already encourages landowners to increase routine culling of wild deer when there are high levels of TB and confirmation of the disease in cats, dogs, pigs and camelids, although still very low, appears to be increasing.
Fewer than 1% of human TB cases are thought to be linked to bovine TB infections.
Defra said last night: "'This finding does not change our risk assessment of the roles of other wildlife at present and we continue to monitor confirmed cases of TB in all animals, including wildlife, as part of our ongoing TB surveillance."
The spokesman added: "The main risk of human M. bovis [bovine TB] infection arising from wild boar is probably occupational, for those handling live infected animals or their carcasses in the field.
"We continue to advise basic personal hygiene practices, including wearing protective equipment to prevent cuts in the skin and to prevent exposure to infectious aerosols."

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Prêmio Nobel de Fisiologia e Medicina visita o CPqGM



Veja o texto para leitura com explicação pelo Prof ao receber o prêmio

Cellular Immune Recognition and the Biological Role of Major Transplantation Antigens

http://nobelprize.org/nobel_prizes/medicine/laureates/1996/zinkernagel-lecture.html


veja video com entrevista em 2007

http://nobelprize.org/mediaplayer/index.php?id=982

Algumas drogas conseguem inibir crescimento de células cancerosas por mais tempo


Mieloma


Study Finds Certain Drugs Can Keep Some Forms of Cancer in Remission Longer

Using certain anticancer drugs for years at a time can help keep some types of cancer in remission longer, doctors reported Thursday.

In another finding, researchers said they had made progress on a long-sought goal — developing a way to screen healthy women for ovarian cancer, potentially catching tumors before they become virtually incurable.

The research findings were among more than 4,000 that will be presented next month at the annual meeting of the American Society of Clinical Oncology. Among the others: a randomized trial showing that twice-a-week yoga sessions can help cancer survivors sleep better and reduce their fatigue.

The studies on longer cancer treatment involve what is called maintenance therapy. It is a strategy for making cancer into a chronic disease like diabetes or hypertension, held in check by continuous use of medicines.

Typically, cancer patients stop taking antitumor drugs once their tumors have shrunk or the disease goes into remission. They do not resume taking drugs until the tumor starts growing again.

In one study of about 600 patients that was made public on Thursday, use of the drug lenalidomide after stem-cell transplant sharply cut the recurrence of multiple myeloma, a cancer of the bone marrow. After three years, 68 percent of the patients who took the drug were free of disease progression, compared with 35 percent of those who got the placebo. “This is of major clinical importance for patients,” Michel Attal of Purpan Hospital in Toulouse, France, the lead author of the study, said in a telephone news conference.

Another study found that two years of maintenance therapy with the drug rituximab cut the risk of cancer recurrence in half among patients with follicular lymphoma, a type of non-Hodgkin’s lymphoma.

The trial involved about 1,000 patients who responded to initial treatment with rituximab plus chemotherapy. Those who continued to get an infusion of rituximab every eight weeks had a relapse rate of 18 percent after about two years. Those who stopped taking the drug after the initial response had a relapse rate of 34 percent.

Neither study has shown yet that maintenance therapy allows people to live longer. For both multiple myeloma and lymphoma, people can live a decade or more after diagnosis. Long-term use of the drugs could cause side effects and is expensive. Two years of maintenance therapy with rituximab, which is sold by Genentech as Rituxan, costs about $50,000. Lenalidomide, sold by Celgene as Revlimid, costs more than $6,000 a month.

Regarding ovarian cancer, doctors have long been searching for the ovarian cancer equivalent of mammography — a way to catch tumors early enough that they are treatable. A big challenge is that ovarian cancer is very rare. That raises the risk of false positives, which would subject many women to needless surgery.

Researchers at the University of Texas MD Anderson Cancer Center say the answer might lie not in some new test but an old one — a test that measures the amount of a protein called CA-125 in the blood. That test is now used to detect recurrence of ovarian cancer but has not been a reliable marker for detecting an initial occurrence of the disease. But the researchers tried to overcome this by following changes in CA-125 over time.

The study involved more than 3,200 healthy, postmenopausal women, who were given a risk score calculated from the CA-125 result and their age.

Those with low risk scores were told to come back a year later for another CA-125 test, and those with intermediate scores were told to come back in three months. Those with the highest risk were referred for transvaginal ultrasound, with possible surgery after that. Over a nine-year period, only eight women underwent surgery. Three were found to have invasive cancers that were caught early enough to treat. Two had borderline cancers, and three did not have cancer.

The researchers said this was encouraging in terms of avoiding unnecessary surgeries. The screening failed to detect two borderline cancers but did not miss any invasive ones.

Still, Dr. Karen Lu, lead author of the study, said the results were “not practice-changing at this time” because it is not known whether the screening strategy would save lives. A study involving more than 200,000 women to answer that question is now under way in Britain, with results expected around 2015.

One of the authors of the study, Dr. Robert Bast, is a co-inventor of the CA-125 test and receives royalties on its use.

The yoga trial, led by researchers at the University of Rochester, randomized 410 survivors of early-stage cancers who reported problems with sleep after their treatment had finished. Half the patients went to a yoga session twice a week for four weeks, and the rest did not. Based on questionnaires, those who did yoga had a bigger improvement in sleep and a reduction in fatigue.

segunda-feira, 17 de maio de 2010

Sobre uso de celular e câncer de cérebro

No proof of mobile cancer risk, major study concludes

By Clare Murphy
Health reporter, BBC News


Mobile phone use remains a cause of concern for some
Using a mobile phone does not appear to increase the risk of developing certain types of brain cancer, the largest study of its kind has concluded.
Analysis of more than 10,000 people by the International Agency for Research on Cancer (IARC) found no relationship between years of use and risk.
There is no known biological mechanism by which mobiles could cause cancer, but there has been public concern.
It is hoped this study will allay some anxieties, as research continues.
The overall rate of brain cancer has not risen in countries where use has long been prevalent - like Sweden, and studies have mostly found no evidence of an increased risk. This latest research is consistent with this.
The 20m euro (£17m) Interphone study, which received some funding from the mobile industry, involved more than 5,000 men and women from 13 countries who had been diagnosed with one of two types of brain cancer - glioma and meningioma - between 2000 and 2004.
These cancers, both rare, were judged to be among the most likely to be influenced by phone use.
The patients were asked to record their mobile phone usage, and then the results were compared with adults of similar age, sex and background who did not have the disease.
Some had been using their phones for more than a decade, making this one of the longest-ranging studies to date.
Extreme results
In fact, most regular users - defined as people who made use of their phone at least once a week - appeared to have a lower risk of brain cancer than those who rarely used a phone. The report authors stressed however this was unlikely to be down to any protective effect of phone use, and more a quirk of the study.

This is consistent with published biological studies, which have not established any effect of exposure to radiation from mobile phones at a cellular level nor found a mechanism by which cancer could be caused
Professor Patricia McKinney
Interphone researcher
University of Leeds
But they also dismissed as problematic the finding that at the other extreme end of the spectrum those using the phone for the longest cumulative periods, more than 1,640 hours, appeared to have a higher risk, regardless of over what period of time this was spread. This was as much as 40% higher for glioma, and 15% higher for meningioma.
Nearly 50 cancer patients reported using their phone more than five hours every day of the week, with 10 recalling that they had used it for 12 hours each day.
"It's not impossible that people were using their phones for this long, but it is highly unlikely," said Professor Anthony Swerdlow of the Institute of Cancer Research, which carried out one of the two UK arms of the study.
The report noted that people with brain tumours were more likely to overestimate the role of a potential risk factor, and that the disease interferes with memory and cognition, undermining the accuracy of the recollections of such extreme use.
Unlike lung cancer, where the risk rises the more cigarettes are smoked, this mobile phone data shows no increased risk until the very heaviest use begins. This was also seen as casting doubt on the reliability of the reports.
"This study cannot answer whether there are long-term risks beyond fifteen years, nor would it have been able to pick up much, much smaller risks," says Professor Swerdlow. "But if there was a large and immediate risk we would have seen it.
"Whether it is worth doing more research, that is a question for society. These are expensive studies, and there are many other things in the world that should be investigated.
"It is society which has to answer the question of how long you continue to investigate something that does not have a biological basis."
There were however reports of some differences within the research team as to how best to interpret the data, and the authors do say that further analysis of long-term, heavy use is in order.
A prospective study was in fact launched last month to examine the long term effects of mobile phone use. Cosmos, the cohort study on mobile communications, will recruit 250,000 and follow them for as long as 30 years.
The lobby group Mast was not assuaged by the Interphone findings, arguing that it wanted to see results for other cancers including salivary gland tumours and acoustic neuromas.


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quarta-feira, 12 de maio de 2010

Jornal cientifico só com vídeos

Divulgado no blog da SBI

Você conhece o periódico científico JOVE (Journal of Visualized Experiments)? Lá você encontra papers em um formato diferente: vídeos-artigos dissecando técnicas de diferentes áreas da biologia.
A novidade é que eles atingiram ontem a marca de 500 vídeos publicados, e em alto estilo: técnica para estudar a arquitetura tridimensional de genomas, do grupo do aclamado Eric Lander.
Vale a pena conferir!

www.jove.com


terça-feira, 11 de maio de 2010

Sessão Cientifica - migração linfocitária no HTLV HAM-TSP



Nesta quinta o aluno de Doutorado do IOC FIOCRUZ, Dr. Eduaro Samo Gudo apresentará resultados do seu projto de tese intitutado

Lymphocyte migration in the ontext of HAM-TST Pathogenesis

domingo, 9 de maio de 2010

pesquisa total do genoma por gens de sobrevivência da micobacteria


Summary

We performed a genome-wide siRNA screen to identify host factors that regulated pathogen load in human macrophages infected with a virulent strain of Mycobacterium tuberculosis. Iterative rounds of confirmation, followed by validation, identified 275 such molecules that were all found to functionally associate with each other through a dense network of interactions. This network then yielded to a molecular description of the host cell functional modules that were both engaged and perturbed by the pathogen. Importantly, a subscreen against a panel of field isolates revealed that the molecular composition of the host interface varied with both genotype and the phenotypic properties of the pathogen. An analysis of these differences, however, permitted identification of those host factors that were invariantly involved, regardless of the diversification in adaptive mechanisms employed by the pathogen. Interestingly, these factors were found to predominantly function through the regulation of autophagy.


Acesse Cell
http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6WSN-4YHS59K-M-7&_cdi=7051&_user=686342&_pii=S0092867410001273&_coverDate=03%2F05%2F2010&_sk=%23TOC%237051%232010%23998599994%231776090%23FLA%23display%23Volume_140,_Issue_5,_Pages_591-754_(5_March_2010)%23tagged%23Volume%23first%3D140%23Issue%23first%3D5%23date%23(5_March_2010)%23&view=c&_gw=y&wchp=dGLbVlW-zSkWb&md5=be5712f33aeec652f74638d9be8feec7&ie=/sdarticle.pdf

Identificação de moléculas envolvidas na invasão de membranas


In Vivo Identification of Regulators of Cell Invasion Across Basement Membranes
David Q. Matus,1 Xiao-Yan Li,2,3 Sarah Durbin,1 Daniel Agarwal,1* Qiuyi Chi,1
Stephen J. Weiss,2,3 David R. Sherwood1†

(Published 4 May 2010; Volume 3 Issue 120 ra35)
Cell invasion through basement membranes during development, immune surveillance, and metastasis remains poorly understood. To gain further insight into this key cellular behavior, we performed an in vivo screen for regulators of cell invasion through basement membranes, using the simple model of Caenorhabditis elegans anchor cell invasion, and identified 99 genes that promote invasion, including the genes encoding the chaperonin complex cct. Notably, most of these genes have not been previously implicated in invasive cell behavior. We characterized members of the cct complex and 11 other gene products, determining the distinct aspects of the invasive cascade that they regulate, including formation of a specialized invasive cell membrane and its ability to breach the basement membrane. RNA interference–mediated knockdown of the human orthologs of cct-5 and lit-1, which had not previously been implicated in cell invasion, reduced the invasiveness of metastatic carcinoma cells, suggesting that a conserved genetic program underlies cell invasion. These results increase our understanding of the genetic underpinnings of cell invasion and also provide new potential therapeutic targets to limit this behavior
Acesse Science
http://stke.sciencemag.org/cgi/reprint/sigtrans;3/120/ra35.pdf

sábado, 8 de maio de 2010

htlv - tb e mortalidade

OBJECTIVES: To investigate the effect of human T-lymphotropic virus type 1 (HTLV-1) on CD4 counts and mortality in tuberculosis (TB) patients with or without human immunodeficiency virus (HIV). METHODS: A prospective study on 280 hospitalized patients with pulmonary TB was performed in Guinea-Bissau, 1994-1997, including HIV, CD4 counts and clinical outcome. We compared the CD4 count levels at the time of inclusion between HIV-negative and HIV-positive patients, with or without HTLV-1. Mortality was determined while patients were on treatment for TB. RESULTS: Median CD4% was significantly higher in HIV-positive subjects co-infected with HTLV-1 compared to HTLV-1-negative patients. Two hundred thirty-three individuals were included in the analysis of mortality, and among HIV-negative subjects the mortality was 18.6/100 person-years . In HIV-2-positive HTLV-1-negative subjects the mortality was 39.5/100 person-years and in HIV-2/HTLV-1 co-infected patients it was 113.6/100 person-years (adjusted mortality rate ratio 4.7, 95% CI 1.5-14.4; p < 0.01). When all HIV-positive patients were analyzed together, corresponding mortality rates were 53.5/100 person-years and 104.8/100 person-years , respectively (not significant). CONCLUSIONS: HIV/HTLV-1 co-infected patients hospitalized for pulmonary TB had a high mortality and had significantly higher CD4% compared to only HIV-positive subjects. This may imply that HTLV-1 has an adverse effect on the immune system in HIV-infected subjects, independently of the CD4 count, that makes co-infected subjects more vulnerable to TB.

terça-feira, 4 de maio de 2010

Projeto para avaliar terapia contra câncer

Cancer project could limit need for animal testing

The study will look at developmental cancer drugs
A project to improve the effectiveness of tests into cancer treatments could limit the need for animal testing, researchers have claimed.
Scientists at the University of Dundee, who will lead the £10m Europe-wide project, said it may also boost safety for those involved in clinical trials.
They want to isolate at an earlier stage those drugs most likely to produce cancerous effects themselves.
Doing so could cut the amount of time and money spent on ineffective drugs.
Researchers said that one of the key drivers behind the plan was the "3 R" issue - the reduction, refinement and replacement of experimental animal use.
The study, known as the MARCAR project and involving 12 organisations from business and academia, will explore the use of non-invasive imaging techniques such as MRI scanning to study the effects of developmental treatments.

Predictions regarding safety of drug compounds can be imprecise and sometimes incorrect
Prof Roland Wolf
As such techniques are non-invasive, long-term studies can be carried out on the same animal over weeks or months.
The method also has the potential to detect pre-cancerous lesions and tumours sooner without sacrificing the animals, meaning smaller numbers of subjects could be used.
Prof Roland Wolf, from the university's biomedical research institute, said: "This would potentially markedly reduce the numbers of animals needed for this kind of research and provide a much more reliable prediction of the rates of toxicity of drugs in development in man."
'Improved safety'
The researchers will focus on a group of drugs known as non-genotoxic carcinogens (NGCs).
These are drugs which when tested are shown to promote biochemical processes which lead to cancer.
At present such potential cancer-causing compounds only tend to be identified following prolonged biological trials.
Prof Wolf said the research would also improve safety for those taking part in drug trials.
He added: "The development of new drugs is a very costly process, partly because of the large number of drugs which never make it to market due to the discovery of cancerous effects during drug development.
"Predictions regarding safety of drug compounds can be imprecise and sometimes incorrect.
"If we could make better predictions at an early stage of drug development it would save a lot of time and money and make the whole process more efficient.
"To achieve that we need to identify early biological indicators, known as 'biomarkers', that can be used to predict the effects of drugs and reliably and robustly predict later cancer developments."