New study suggests ALS could be caused by a retrovirus
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A retrovirus that inserted itself into the human genome thousands of years ago may be responsible for some cases of the neurodegenerative disease amyotrophic lateral sclerosis (ALS), also known as Lou Gherig’s disease. The finding, made by Johns Hopkins scientists, may eventually give researchers a new way to attack this universally fatal condition.
While roughly 20 percent of ALS cases appear to have a genetic cause, the vast majority of cases appear to arise sporadically, with no known trigger. Research groups searching for a cause of this so-called sporadic form had previously spotted a protein known as reverse transcriptase, a product of retroviruses such as HIV, in ALS patients’ serum samples, suggesting that a retrovirus might play a role in the disease. However, these groups weren’t able to trace this reverse transcriptase to a specific retrovirus, leaving some scientists in doubt whether retroviruses are involved in ALS.
Seeking to verify whether a culprit retrovirus indeed exists, Avindra Nath, M.D., a professor of neurology at the Johns Hopkins University School of Medicine, and colleagues examined brain samples from 62 people: 28 who died from ALS, 12 who died from chronic, systemic diseases such as cancer, 10 who died from accidental causes and 12 who had another neurodegenerative disease, Parkinson’s disease, at the time of their deaths. Using a technique known as polymerase chain reaction, the researchers searched for messenger RNA (mRNA) transcripts from retroviruses, a chemical signature that retroviruses were active in these patients.
Cancer breakthrough to prevent heart failure and increase survival rates
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A breakthrough by scientists at Queen’s could help reduce heart failure in cancer patients around the world, and ultimately increase survival rates.
Scientists at Queen’s Centre for Vision and Vascular Science have discovered the role of an enzyme which, when a patient receives chemotherapy, can cause life-threatening damage to the heart. This has, until now, restricted the amount of chemotherapy doses a patient can receive; but while protecting the heart, this dilutes the chemotherapy’s effectiveness in destroying cancerous tumours.
By identifying the role of the enzyme - NADPH oxidase - work can now go ahead into making chemotherapy treatments more effective and reduce the toxic effects of cancer treatment on the heart.
University of Miami scientists track great hammerhead shark migration
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A study led by scientists at the University of Miami (UM) Rosenstiel School of Marine & Atmospheric Science details the first scientific research to successfully track a great hammerhead shark using satellite tag technology.
Rosenstiel Schhol Research Assistant Professor Neil Hammershlag and colleagues tracked one of the nomadic sharks for 62 days to uncover its northeast journey from the coast of South Florida to the middle of the Atlantic off the coast of New Jersey. The straight line point-to-point distance of 1,200 kilometers (745 miles) represents a range extension for this species. The data also revealed the shark entering the Gulf Stream current and open-ocean waters of the northwestern Atlantic Ocean.
“This animal made an extraordinary large movement in a short amount of time,” said Hammerschlag, director of the R.J. Dunlap Marine Conservation Program at the UM Rosenstiel School. “This single observation is a starting point, it shows we need to expand our efforts to learn more about them.”
Rare HIV-positive individuals shed light on how body could effectively handle infection
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Although untreated HIV infection eventually results in immunodeficiency (AIDS), a small group of people infected with the virus, called elite suppressors (0.5 percent of all HIV-infected individuals), are naturally able to control infection in the absence of antiretroviral therapy, or HAART. Elite suppressors and HIV- infected individuals treated with HAART have similar levels of virus in the blood stream. However, levels of HIV integrated into immune cells are much lower in elite suppressors compared to levels in cells from HIV-infected individuals on HAART, according to a study by University of Pennsylvania School of Medicine researchers published in PLoS Pathogens.
Elite suppressors are thought to have a more effective immune response to HIV; specifically, more effective killer T cells, the subgroup of white blood cells that kill cells infected with viruses. HIV is an RNA virus that converts its RNA genome into DNA intermediates in order to replicate. One important step in the HIV life cycle is integration - where HIV DNA inserts into the chromosomes of human helper T cells. Cells that contain the integrated form of HIV DNA and are metabolically less active appear to be resistant to antiretroviral therapy and persist in the host, forming a latent reservoir.
Lack of health insurance limits hepatitis C patients’ access to latest antiviral therapy
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New research has determined that patients in the U.S. with hepatitis C virus (HCV) are twice as likely to not have health insurance coverage compared with those without the disease. In fact researchers found only a third of HCV infected Americans have access to antiviral therapy; the remaining are either uninsured or not candidates for therapy due to treatment contraindications. Details of this study are published in the March issue of Hepatology, a peer-reviewed journal of the American Association for the Study of Liver Diseases (AASLD).
HCV is the most common cause of chronic liver disease, hepatocellular (liver) cancer, and liver transplantation in the U.S., with up to 85% of HCV-positive individuals (3.5 million) developing chronic HCV infection. Symptoms of chronic HCV are non-specific which can inhibit diagnosis and as many as 75% of patients are unaware of their HCV infection (Hagan et al., 2006). Furthermore, the Centers for Disease Control and Prevention (CDC) estimates that HCV causes 12,000 deaths in the U.S. each year.
“Successful treatment with antiviral therapy improves health-related quality of life in patients with HCV and could potentially reduce morbidity and mortality in patients,” said Zobair Younossi, MD, MPH, from the Center of Liver Diseases at Inova Fairfax Hospital in Virginia and lead author of the study. “A significant number of HCV patients, however, may not even have access to antiviral therapy due to lack of adequate health insurance coverage.” It is estimated to cost up to $48,000 per year for monitoring and treatment of HCV.
Study examines effectiveness of mammography screening for women with prior breast cancer
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Mammography screening in women with a personal history of breast cancer detects second breast cancers at an early stage, but has lower accuracy, compared to screening in women without prior breast cancer, according to a study in the February 23 issue of JAMA.
“The high prevalence of breast cancer survivors is due to general gains in life expectancy and to improved survival in women with a personal history of breast cancer (PHBC), attributable to improvements in local and systemic treatments and early detection,” the authors write. Women with PHBC are at risk of developing second breast cancers and are recommended for annual screening mammography, but few high-quality data exist on screening accuracy in PHBC women, according to background information in the article. The authors add that valid estimates of the accuracy of screening mammography are needed to guide clinical practice and policy and to inform clinicians and PHBC women of expected screening outcomes.
Nehmat Houssami, M.B.B.S., Ph.D., of the University of Sydney, Australia, and colleagues from the Breast Cancer Surveillance Consortium and Group Health Research Institute, Seattle, conducted a study to examine the accuracy and outcomes of screening mammography and factors associated with screening outcomes in women with a PHBC, who were matched to non-PHBC women and screened (1996-2007) through facilities affiliated with the Breast Cancer Surveillance Consortium. There were 58,870 screening mammograms in 19,078 women with a history of early-stage (in situ or stage I-II invasive) breast cancer and 58,870 matched (breast density, age group, mammography year, and registry) screening mammograms in 55,315 non-PHBC women.
Anti-Clotting Agent Does Not Improve Outcomes of Patients with Severe Pneumonia
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Use of the blood clot-inhibiting medication tifacogin does not appear to improve outcomes of patients with severe community-acquired pneumonia (sCAP), according to a study conducted by researchers from North and South America, Europe, Asia and Africa. The drug had shown some potential benefit in the sCAP subgroup of an earlier trial involving sepsis patients.
The findings were published online ahead of the print edition of the American Thoracic Society’s American Journal of Respiratory and Critical Care Medicine.
“Administration of tifacogin showed no treatment benefit in this large population of patients with severe CAP,”said Richard Wunderink, MD, professor of pulmonary and critical care medicine at Northwestern University’s Feinberg School of Medicine. “This result was consistent across a range of disease severity indices.”
Paper Urges Physicians to Assess Practices for Care of LGBT Patients
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Noting that a patient’s level of comfort and trust significantly impacts the type of medical care provided and received, a newly published paper outlines ways that physicians can examine how their own beliefs and practice habits affect their ability to treat lesbian, gay, bisexual and transgender (LGBT) patients. The paper, which appears in the current issue of The Health Care Manager, outlines several minor but effective changes physicians can make to establish an office environment that is comfortable to all patients.
“LGBT patients can disproportionately experience social and behavioral risk factors that can affect health,” said lead author Dr. Joshua Coren, a family physician at the UMDNJ-School of Osteopathic Medicine. “When evaluating these risk factors, physicians need to ask questions nonjudgmentally to avoid causing their LGBT patients to feel scrutinized or even stigmatized.”
Among the authors’ recommendations are changing background information forms by expanding gender identification and relationship preference categories, noting that when only two options are available transgendered patients may struggle to identify their gender or bisexual patients may not be able to accurately describe their polyamorous relationship with men and women.
Study shows rapamycin reverses myocardial defects in mouse model of LEOPARD syndrome
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Congenital heart diseases affect approximately one in 100 patients, making them the most common type of birth defect and the number-one cause of pediatric deaths.
Now a new study showing that the mTOR inhibitor drug rapamycin can reverse cardiac muscle damage in a mouse model of the congenital disease LEOPARD syndrome not only identifies the first possible medical treatment for this rare condition, but also demonstrates the importance of targeted therapies in managing congenital diseases.
The research, led by investigators at Beth Israel Deaconess Medical Center (BIDMC), is published in the March issue of the Journal of Clinical Investigation (JCI), which appears on-line today.
Common birth control pill not tied to heart attacks
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Contrary to earlier signs that women on the Pill have a higher risk of heart disease, a new look at the medical literature found no link between heart attacks and the so-called mini-pills.
Such pills, including brands like Micronor and Ovrette, contain the hormone progestin, but not the estrogen of traditional birth control pills. The results also held for other progestin-only birth control products, such as implants and shots.
“I think this is very reassuring that there is no increased risk of heart attack,” said Chrisandra Shufelt of the Women’s Heart Center at Cedars-Sinai Medical Center, who was not involved in the review.
Fiber intake associated with reduced risk of death
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Dietary fiber may be associated with a reduced risk of death from cardiovascular, infectious and respiratory diseases, as well as a reduced risk of death from any cause over a nine-year period, according to a report posted online today that will be published in the June 14 print issue of Archives of Internal Medicine, one of the JAMA/Archives journals.
Fiber, the edible part of plants that resist digestion, has been hypothesized to lower risks of heart disease, some cancers, diabetes and obesity, according to background information in the article. It is known to assist with bowel movements, reduce blood cholesterol levels, improve blood glucose levels, lower blood pressure, promote weight loss and reduce inflammation and bind to potential cancer-causing agents to increase the likelihood they will be excreted by the body.
Yikyung Park, Sc.D., of the National Cancer Institute, Rockville, Md., and colleagues analyzed data from 219,123 men and 168,999 women in the National Institutes of Health-AARP Diet and Health Study. Participants completed a food frequency questionnaire at the beginning of the study in 1995 and 1996. Causes of death were determined by linking study records to national registries.
Gonorrhea acquires a piece of human DNA
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If a human cell and a bacterial cell met at a speed-dating event, they would never be expected to exchange phone numbers, much less genetic material. In more scientific terms, a direct transfer of DNA has never been recorded from humans to bacteria.
Until now. Northwestern Medicine researchers have discovered the first evidence of a human DNA fragment in a bacterial genome – in this case, Neisseria gonorrhoeae, the bacterium that causes gonorrhea. Further research showed the gene transfer appears to be a recent evolutionary event.
The discovery offers insight into evolution as well as gonorrhea’s nimble ability to continually adapt and survive in its human hosts. Gonorrhea, which is transmitted through sexual contact, is one of the oldest recorded diseases and one of a few exclusive to humans.
Study finds that folate does not offer protection against preterm delivery
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In a study to be presented today at the Society for Maternal-Fetal Medicine’s (SMFM) annual meeting, The Pregnancy Meeting ™, in San Francisco, researchers will present findings that show that folate intake before and during pregnancy does not protect Norwegian women against spontaneous preterm delivery.
“Sufficient folate intake has been studied as a possible protecting factor against spontaneous preterm delivery with conflicting results,” said Verena Senpiel, M.D., one of the study’s authors. “Preterm delivery is the major cause of perinatal mortality and morbidity worldwide and still difficult to predict and prevent. So when a recent American study found that preconceptional folate supplementation could reduce the risk for early spontaneous preterm delivery 50-70% we hoped to confirm these findings in another big cohort study.”
The study selected controls and cases from the Norwegian Mother and Child Cohort Study (http://www.fhi.no/) that included 72,989 children. Cases were defined as singleton live births with spontaneous onset of preterm delivery between 22 and 36 gestational weeks and after pregnancies without medical or obstetric complications. Controls were chosen according to the same criteria, except spontaneous onset of term delivery between gestational weeks 39 and 40. Folate data was obtained from questionnaires completed at gestational week 17, 22 and 30, including a semi-quantitative food frequency questionnaire in the second trimester (week 22).
Common insecticide used in homes associated with delayed mental development of young children
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When the EPA phased out the widespread residential use of chlorpyrifos and other organophosphorus (OP) insecticides in 2000-2001 because of risks to child neurodevelopment, these compounds were largely replaced with pyrethroid insecticides. But the safety of these replacement insecticides remained unclear, as they had never been evaluated for long-term neurotoxic effects after low-level exposure. In the first study to examine the effects of these compounds on humans and the first evaluation of their potential toxicity to the developing fetal brain, scientists of the Columbia Center for Children’s Environmental Health at Columbia University’s Mailman School of Public Health found a significant association between piperonyl butoxide (PBO), a common additive in pyrethroid formulations, measured in personal air collected during the third trimester of pregnancy, and delayed mental development at 36 months. Findings from the study are online in the journal, Pediatrics.
The study was conducted with a subset of 725 pregnant women participating in a prospective longitudinal study of black and Dominican women living in upper Manhattan and the South Bronx underway at the Columbia Center for Children’s Environmental Health (CCCEH). The insecticide permethrin was selected for the evaluation because it is one of the most common pyrethroid insecticides used in U.S. homes, as well as the most commonly sold pesticide, according to a nationally representative sample. PBO, a chemical that is added to insecticides to increase efficacy was also selected for evaluation. Any detection of PBO in air is a marker of a pyrethroid insecticide application.
In all, 342 women were studied for permethrin exposure in personal air during pregnancy; 272 for permethrin in maternal and umbilical cord plasma; and 230 were evaluated for exposure to PBO. To collect the air samples, mothers from the CCCEH Mothers and Newborns cohort wore a small backpack holding a personal ambient air monitor for 48 hours during the third trimester of pregnancy.
CHEO opens new “active living” clinic for children to fight diabetes
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Severely obese children and those at high risk of type 2 diabetes will have a place to get counselling and treatment with the opening of a new outpatient clinic run by the Children’s Hospital of Eastern Ontario.
Among other things, the Centre for Healthy Active Living will provide early screening to children who have at least one parent with type 2 diabetes, commonly linked to sedentary lifestyles and diets loaded with fat and sugar. Research suggests children of parents with type 2 diabetes have a higher risk of developing the disease themselves.
Diabetes, which disrupts sugar uptake in the blood, is the leading cause of blindness, amputations and kidney failure; over a lifetime, it can triple a person’s risk for heart attack, stroke and Alzheimer’s disease.
