PolygenicBlog

Pesticides Decimate Biodiversity | The Scientist Magazine®

noreply@blogger.com (Chris Carter) — Wed, 19 Jun 2013 12:47:44 PDT

"Pesticide use is reducing the diversity of aquatic insects and other invertebrates at an alarming rate, according to a study published this week in Proceedings of the National Academy of Sciences. Specifically, researchers studying the loss of biodiversity in Europe and Australia found large differences in the number of species in regions contaminated with insecticides and fungicides and regions that were pesticide-free."

Exposure to high pollution levels during pregnancy may increase risk of having child with autism

noreply@blogger.com (Chris Carter) — Wed, 19 Jun 2013 02:43:58 PDT

"Women in the U.S. exposed to high levels of air pollution while pregnant were up to twice as likely to have a child with autism as women who lived in areas with low pollution, according to a new study from Harvard School of Public Health . It is the first large national study to examine links between autism and air pollution across the U.S."

Marketing Unhealthy Foods To Children Is "Disastrous"

noreply@blogger.com (Chris Carter) — Wed, 19 Jun 2013 00:57:30 PDT

MNT "The marketing of unhealthy food to children has been disastrously effective and is only making childhood obesity even more of a problem, says The World Health Organization (WHO).

WHO is calling for more control on marketing unhealthy foods high in sugars, salt, and trans fats. These types of foods are only contributing to the ever-increasing childhood obesity pandemic."

Chip Identifies Bacterial Infection In Minutes, Not Days

noreply@blogger.com (Chris Carter) — Tue, 18 Jun 2013 23:16:17 PDT

"Bacterial infections kill tens of thousands every year. The fact it can take days to find out which bacteria are behind the infections and even longer to establish exactly which drugs will work, doesn't help. Now according to a new study, a chip that identifies bacteria in minutes promises to slash those timescales. And not only does the chip identify the specific pathogen, it can also tell which drugs it is resistant to, say researchers from the University of Toronto in Canada."

The secret of DNA methylation

noreply@blogger.com (Chris Carter) — Tue, 18 Jun 2013 23:02:12 PDT

Methylation refers to a chemical modification of DNA and this modification can occur in millions of positions in the DNA sequence. Until now, scientists believed that this epigenetic phenomenon actively reduced the expression of certain genes. Today, a team of researchers from the University of Geneva (UNIGE), Switzerland, led by Emmanouil Dermitzakis, Louis-Jeantet Professor at the Faculty of Medicine, reveals that this is not always the case and that DNA methylation may play both a passive and active role in gene regulation. The mechanistic relationships between DNA sequence variability and gene expression therefore prove to be more complex and variable than originally assumed.

Fibromyalgia is not all in your head, new research confirms

noreply@blogger.com (Chris Carter) — Tue, 18 Jun 2013 22:59:39 PDT

"Fibromyalgia, a painful condition affecting approximately 10 million people in the U.S., is not imaginary after all, as some doctors have believed. A discovery, published this month in Pain Medicine (the journal of the American Academy of Pain Medicine), clearly now demonstrates that fibromyalgia may have a rational biological basis located in the skin."

Expelled DNA that traps toxins may backfire in obese

noreply@blogger.com (Chris Carter) — Tue, 18 Jun 2013 22:57:37 PDT

The body's most powerful immune cells may have a radical way of catching their prey that could backfire on people who are overweight and others at risk for cancer, diabetes and chronic inflammation, suggests a new Cornell study.The study is the first to show that the DNA of macrophages, the biggest immune cells, can unravel and move outside the cell to snag invading pathogens. Called extracellular traps, these sticky DNA remnants can occur anywhere, but the study found a troubling number inside rafts of macrophages surrounding dead fat cells in obese mice.
In that extracellular environment, the traps feed a vicious cycle of inflammation, increasing risk of several major diseases, the scientists predict. Uncovering what causes macrophage DNA to unravel, the study included a description indicating new preventative therapies for these diseases may be near at hand.

Treating One Infection May Worsen Another

noreply@blogger.com (Chris Carter) — Tue, 18 Jun 2013 08:25:28 PDT

MNT "A study of wild mice, which typically carry several parasitic infections at a time, finds treating one infection may worsen another. Led by the University of Edinburgh, the study is the first of its kind to suggest multiple infections may compete with each other and attempts to eliminate one could give another a foothold that results in poorer health."

Infections increase risk of mood disorders, study suggests

noreply@blogger.com (Chris Carter) — Tue, 18 Jun 2013 04:13:46 PDT

"New research shows that every third person who is diagnosed for the first time with a mood disorder has been admitted to hospital with an infection prior to the diagnosis. The study is the largest of its kind to date to show a clear correlation between infection levels and the risk of developing mood disorders."

Exposure to BPA in developing prostate increases risk of later cancer: Ubiquitous plasticizers may have long-term health effects

noreply@blogger.com (Chris Carter) — Tue, 18 Jun 2013 04:11:39 PDT

"Early exposure to BPA (bisphenol A) -- an additive commonly found in plastic water bottles and soup can liners -- causes an increased cancer risk in an animal model of human prostate cancer, according to University of Illinois at Chicago researcher Gail Prins."

Chemical in antibacterial soap fed to nursing rats harms offspring, study finds

noreply@blogger.com (Chris Carter) — Tue, 18 Jun 2013 04:10:09 PDT

A mother's exposure to triclocarban, a common antibacterial chemical, while nursing her babies shortens the life of her female offspring, a new study in rats finds."

'via Blog this'

Obesity leads to brain inflammation, and low testosterone makes it worse

noreply@blogger.com (Chris Carter) — Tue, 18 Jun 2013 04:08:47 PDT

The findings suggest that low testosterone and obesity interact to regulate inflammation of the nervous system, which may increase the risk of disorders such as type 2 diabetes and Alzheimer's disease"

Blocking overactive receptor in Alzheimer's mice recovers memory loss and more

noreply@blogger.com (Chris Carter) — Mon, 17 Jun 2013 23:04:19 PDT

"The researchers found an increased level of a receptor known as bradykinin B1 receptor (B1R) in the brain of mice with AD, a receptor involved in inflammation. "By administering a molecule that selectively blocks the action of this receptor, we observed important improvements in both cognitive and cerebrovascular function," says Dr. Baptiste Lacoste, research fellow who conducted the study at The Neuro and now pursuing his training at Harvard Medical School in Boston. "Alzheimer's disease destroys nerve cells and also compromises the function of blood vessels in the brain. Not only were there improvements in learning and memory, but also marked recovery in blood flow and vascular reactivity, i.e. the ability of cerebral vessels to dilate or constrict when necessary." Proper functioning of blood vessels in the brain is vital to providing nutrients and oxygen to nerve cells, and vascular diseases represent important risk factors for developing AD at an advanced age."

Exposure to BPA in developing prostate increases risk of later cancer

noreply@blogger.com (Chris Carter) — Mon, 17 Jun 2013 23:00:36 PDT

"Early exposure to BPA (bisphenol A) – an additive commonly found in plastic water bottles and soup can liners – causes an increased cancer risk in an animal model of human prostate cancer, according to University of Illinois at Chicago researcher Gail Prins. Prins presented her findings at the ENDO 2013 meeting in San Francisco June 17."

Opinion: Toxicants and the Brain | The Scientist Magazine®

noreply@blogger.com (Chris Carter) — Mon, 17 Jun 2013 12:08:47 PDT

The recent US and European BRAIN initiative do not identify brain development as a key area of research, nor the possible effects of environmental toxicants on brain health.

This is a shame. A wealth of research shows that metals, pesticides, solvents, and other chemicals can seriously impede brain development in children. So far, we have identified about a dozen chemicals that can harm brain development in children and result in lasting deficits and disease, and there are more than 200 additional substances, the majority commonly present in the environment, that are known to be neurotoxic in adults, but for which we have little or no evidence for the effects on brain development. Furthermore, animal models suggest that brain toxicity during early development may lead to degenerative brain disease, such as Parkinson’s and autism, later in life. We need to understand better the causation and emergence of brain diseases as a result of toxic chemicals.

Platelets Help Tackle Bacteria | The Scientist Magazine®

noreply@blogger.com (Chris Carter) — Mon, 17 Jun 2013 12:00:35 PDT

Platelets may contribute to protection against bacterial infection, according to new research published today (June 16) in Nature Immunology. Scientists found that in the livers of mice, platelets collaborated with specialized white blood cells to capture and engulf blood-borne bacteria, and this interaction helped protect the animals from bacterial infection.

Plasma total homocysteine is associated with DNA methylation in patients with schizophrenia

noreply@blogger.com (Chris Carter) — Sun, 16 Jun 2013 13:28:15 PDT

Schizophrenia (SCZ) is a devastating psychiatric disorder with a median lifetime prevalence rate of 0.7–0.8%. Elevated plasma total homocysteine has been suggested as a risk factor for SCZ, and various biological effects of hyperhomocysteinemia have been proposed to be relevant to the pathophysiology of SCZ. As increased attention is paid to aberrant DNA methylation in SCZ, homocysteine is attracting additional interest as a potential key substance. Homocysteine is formed in the methionine cycle, which is involved in one-carbon methyl group-transfer metabolism, and it acts as a methyl donor when it is converted to S-adenosyl-methionine. To date, no studies have examined the relationship between homocysteine and genome-wide DNA methylation in SCZ. We examined the relationship between plasma total homocysteine and DNA methylation patterns in the peripheral leukocytes of patients with SCZ (n = 42) using a quantitative high-resolution DNA methylation array (485,764 CpG sites). Significant homocysteine-related changes in DNA methylation were observed at 1,338 CpG sites that were located across whole gene regions, including promoters, gene bodies and 3′-untranslated regions. Of the 1,338 sites, 758 sites (56.6%) were located in the CpG islands (CGIs) and in the regions flanking CGIs (CGI: 15.8%; CGI shore: 28.2%; CGI shelf: 12.6%), and positive correlations between plasma total homocysteine and DNA methylation were observed predominantly at CpG sites in the CGIs. Our results suggest that homocysteine might play a role in the pathogenesis of SCZ via a molecular mechanism that involves alterations to DNA methylation.

Antibiotic treatment expands the resistance reservoir and ecological network of the phage metagenome : Nature : Nature Publishing Group

noreply@blogger.com (Chris Carter) — Sun, 16 Jun 2013 13:27:16 PDT

The mammalian gut ecosystem has considerable influence on host physiology, but the mechanisms that sustain this complex environment in the face of different stresses remain obscure. Perturbations to the gut ecosystem, such as through antibiotic treatment or diet, are at present interpreted at the level of bacterial phylogeny. Less is known about the contributions of the abundant population of phages to this ecological network. Here we explore the phageome as a potential genetic reservoir for bacterial adaptation by sequencing murine faecal phage populations following antibiotic perturbation. We show that antibiotic treatment leads to the enrichment of phage-encoded genes that confer resistance via disparate mechanisms to the administered drug, as well as genes that confer resistance to antibiotics unrelated to the administered drug, and we demonstrate experimentally that phages from treated mice provide aerobically cultured naive microbiota with increased resistance. Systems-wide analyses uncovered post-treatment phage-encoded processes related to host colonization and growth adaptation, indicating that the phageome becomes broadly enriched for functionally beneficial genes under stress-related conditions. We also show that antibiotic treatment expands the interactions between phage and bacterial species, leading to a more highly connected phage–bacterial network for gene exchange. Our work implicates the phageome in the emergence of multidrug resistance, and indicates that the adaptive capacity of the phageome may represent a community-based mechanism for protecting the gut microflora, preserving its functional robustness during antibiotic stress.

Children help reveal infectious diabetes trigger

noreply@blogger.com (Chris Carter) — Fri, 14 Jun 2013 14:09:40 PDT

Comparing cases of Type 1 diabetes in North East children with those of flu, the researchers found similar distribution patterns. This suggests that like flu or chicken pox, type 1 diabetes may in part be infectious and display similar "mini-epidemics".

Over a six year cycle, they found that cases not only varied in frequency but also peaked at certain times of the year. This pattern, of both short and long-term cycles, could be caused by an infection carried by a wild animal, which then triggers diabetes Type 1 in those already genetically predisposed to the disease.

Antibodies bound to Aβ oligomers potentiate the neurotoxicity of Aβ by activating microglia

noreply@blogger.com (Chris Carter) — Fri, 14 Jun 2013 01:27:25 PDT

Beta amyloid (Aβ) oligomers are thought to contribute to the pathogenesis of Alzheimer's disease. However, clinical trials using Aβ immunization were unsuccessful due to strong brain inflammation, the mechanisms of which are poorly understood. In this study we tested whether monoclonal antibodies to oligomeric Aβ would prevent the neurotoxicity of Aβ oligomers in primary neuronal-glial cultures. However, surprisingly, the antibodies dramatically increased the neurotoxicity of Aβ. Antibodies bound to monomeric Aβ fragments were non-toxic to cultured neurons, while antibodies to other oligomeric proteins: hamster polyomavirus major capsid protein, human metapneumovirus nucleocapsid protein and measles virus nucleocapsid protein, strongly potentiated the neurotoxicity of their antigens. The neurotoxicity of antibody-oligomeric antigen complexes was abolished by removal of the Fc region from the antibodies or by removal of microglia from cultures, and was accompanied by inflammatory activation and proliferation of the microglia in culture. In conclusion, we find that immune complexes formed by Aβ oligomers or other oligomeric/multimeric antigens and their specific antibodies can cause death and loss of neurons in primary neuronal-glial cultures via Fc-dependent microglial activation. The results suggest that therapies resulting in antibodies to oligomeric Aβ or oligomeric brain virus proteins should be used with caution or with suppression of microglial activation.

Monozygotic twins affected with major depressive disorder have greater variance in methylation than their unaffected co-twin.

noreply@blogger.com (Chris Carter) — Thu, 13 Jun 2013 10:21:44 PDT

Our understanding of major depressive disorder (MDD) has focused on the influence of genetic variation and environmental risk factors. Growing evidence suggests the additional role of epigenetic mechanisms influencing susceptibility for complex traits. DNA sequence within discordant monozygotic twin (MZT) pairs is virtually identical; thus, they represent a powerful design for studying the contribution of epigenetic factors to disease liability. The aim of this study was to investigate whether specific methylation profiles in white blood cells could contribute to the aetiology of MDD. Participants were drawn from the Queensland Twin Registry and comprised 12 MZT pairs discordant for MDD and 12 MZT pairs concordant for no MDD and low neuroticism. Bisulphite treatment and genome-wide interrogation of differentially methylated CpG sites using the Illumina Human Methylation 450 BeadChip were performed in WBC-derived DNA. No overall difference in mean global methylation between cases and their unaffected co-twins was found; however, the differences in females was significant (P=0.005). The difference in variance across all probes between affected and unaffected twins was highly significant (P<2.2 × 10(-16)), with 52.4% of probes having higher variance in cases (binomial P-value<2.2 × 10(-16)). No significant differences in methylation were observed between discordant MZT pairs and their matched concordant MZT (permutation minimum P=0.11) at any individual probe. Larger samples are likely to be needed to identify true associations between methylation differences at specific CpG sites.

BPA linked to obesity risk in puberty-age girls

noreply@blogger.com (Chris Carter) — Thu, 13 Jun 2013 03:29:17 PDT

BPA linked to obesity risk in puberty-age girls: "Girls between 9 and 12 years of age with higher-than-average levels of bisphenol-A (BPA) in their urine had double the risk of being obese than girls with lower levels of BPA, according to a Kaiser Permanente study published today in the journal PLOS ONE."

Fetal neuromaturation associated with mother's exposure to DDT and other environmental contaminants

noreply@blogger.com (Chris Carter) — Wed, 12 Jun 2013 23:38:17 PDT

Fetal neuromaturation associated with mother's exposure to DDT and other environmental contaminants: " study led by researchers at the Johns Hopkins Bloomberg School of Public Health has for the first time found that a mother's higher exposure to some common environmental contaminants was associated with more frequent and vigorous fetal motor activity. Some chemicals were also associated with fewer changes in fetal heart rate, which normally parallel fetal movements. The study of 50 pregnant women found detectable levels of organochlorines in all of the women participating in the study -- including DDT, PCBs and other pesticides that have been banned from use for more than 30 years."

Valacyclovir improves cognition in bipolar patients : Clinical Psychiatry News

noreply@blogger.com (Chris Carter) — Wed, 12 Jun 2013 23:00:03 PDT

A 4-month course of the oral antiviral agent valacyclovir boosted cognition in herpes simplex virus-1–seropositive patients with bipolar disorder and cognitive impairment in a randomized, double-blind placebo-controlled clinical trial.

In this 60-patient study, 53% of participants assigned to valacyclovir (Valtrex) exhibited a clinically meaningful improvement in cognitive function, defined as at least a 10-point gain over baseline on the Repeatable Battery for the Assessment of Neurological Status (RBANS), compared with 14% in the placebo arm, Dr. Jennifer L. Payne reported at a meeting of the New Clinical Drug Evaluation Unit sponsored by the National Institute of Mental Health."

Genetic studies lead to clinical trial of new treatment for type 1 diabetes | BreakThrough Digest Medical News

noreply@blogger.com (Chris Carter) — Tue, 11 Jun 2013 23:04:24 PDT

Type 1 diabetes is known to be a genetically complex disease ? there is no single gene that causes the disease, but rather dozens of genes that increase the risk of developing the disease. However, genetic studies have identified variants of one particular gene ? known as interleukin-2, or IL2 ? which appears to play a prominent role. IL-2 is important in helping regulate the immune system.

Now, for the first time, researchers at Addenbrooke’s Hospital and the Wellcome Trust funded Cambridge Institute for Medical Research (CIMR) at the University of Cambridge are investigating whether interleukin-2 in the form of a drug called aldesleukin (Proleukin) could be used to halt the damage to the pancreas in people with newly diagnosed type 1 diabetes and, if so, what dose of the drug is required for the best results.