infections

Toothed whales have survived millions of years without key antiviral proteins

Researchers at the Stanford University School of Medicine have determined that toothed whales lack functional Mx genes — a surprising discovery, since all 56 other sequenced mammals in the study possess these genes to fight off viruses like HIV, measles and flu.

Modern toothed whales, including dolphins, orcas and sperm whales, have inherited defunct copies of the Mx1 and Mx2 genes, profoundly altering their immune systems. The basic role of theseMx genes is to make proteins that fight viral infections. The researchers hope that understanding this newly discovered mysterious genetic anomaly will help preserve these cetaceans as they face extensive die-offs.


Link

“The Infected Brain”, a Haiku
(Part of the “Windows into the Mind” series)

The Infected Brain
Poisoned with all it has learned
You’ll never be cured.

Posted 10/22/2012

Wanna appear in your very own Daily Doodle?  CLICK HERE!
FAQ  TWITTER  FACEBOOK
  SOCIETY6

Kids' urinary infections usually not a kidney risk


“If there is no structural abnormalities in the kidney ultrasound after the first UTI, the parents should not be worried at all” about the risk of chronic kidney disease, said lead researcher Dr. Jarmo Salo of the University of Oulu in Finland.Recurrent UTIs in young children have been seen as a possible risk factor for chronic kidney disease later in life. That’s especially true if a child has what’s called vesicoureteral reflux, or VUR.About 1 percent of children have VUR, where some urine backs up from the bladder into the kidneys. The reflux itself does not damage the kidneys, but because bacteria in the urine can get into the kidneys, these children are more prone to kidney infections that can lead to scarring.But the idea that repeat UTIs and VUR are risk factors for chronic kidney disease later in life is not universally accepted – nor is the practice of testing children for VUR when they have a urinary tract infection.So for the new study, reported in the journal Pediatrics, researchers in Finland combed the medical literature to look for evidence that childhood UTIs are a risk factor for chronic kidney disease.They also reviewed the records of all 366 patients who were treated for chronic kidney disease at their hospital over one year.The team found 10 published reports that either looked at the history of childhood UTIs in people with chronic kidney disease, or that followed children with UTIs to see how their kidney health fared.Among the 1,576 patients in those studies, there was no evidence that childhood UTIs – even along with VUR – were the main cause of chronic kidney disease, according to the researchers.And of the kidney disease patients who did have a history of childhood UTIs, all also had structural abnormalities in their kidneys. Similarly, of the 366 patients at their center, the researchers found that only three had repeat childhood UTIs that might have contributed to their chronic kidney disease – and all had structural abnormalities in the kidneys.Such structural abnormalities – problems like an obstruction in the kidneys – can be picked up by an ultrasound when a young child is diagnosed with a UTI.But Salo told Reuters Health in an email that the findings suggest that kids with VUR are at no increased risk of kidney disease, as long as there are no structural abnormalities in the kidneys.NO LONGER LOOKING IN FINLANDWhen VUR is diagnosed, it is usually because doctors specifically look for it in a young child with a UTI. That takes a special test called a cystogram, where a catheter is placed in the bladder and the bladder is filled with fluid. X-rays allow the doctor to see if the fluids back up into the kidneys.Salo said doctors in Finland no longer “actively” look for VUR because there’s evidence that it is a “normal phenomenon,” and that treating it does not prevent long-term kidney damage.“We suggest that the (x-ray) imaging studies are not necessary if the child has structurally normal kidneys in ultrasound,” Salo said.But a pediatric urologist not involved in the study cautioned against making a “sweeping” recommendation against VUR testing.“The good news for parents is yes, the chances of your child developing kidney disease will be very low,” said Dr. Hiep T. Nguyen of Children’s Hospital Boston.However, he told Reuters Health, repeat UTIs in young children (generally younger than 5) are not the same as those in older kids or adults. And some of those children are at increased risk for kidney damage – particularly if they have more-severe, “high-grade” VUR.What’s more, Nguyen said, there is evidence that finding and treating high-grade VUR may prevent kidney damage. Treatment involves low doses of antibiotics to prevent repeat UTIs and periodic testing to see if the reflux has gone away. Some children with severe VUR end up having surgery to correct the problem if they keep getting infections.Mild reflux typically goes away on its own – though, in North American, doctors still prescribe low-dose antibiotics to prevent the UTIs.Nguyen said that a young child with a UTI should have an ultrasound “at a minimum” to look for structural abnormalities in the kidneys. Salo agreed.SHOULD DOCTORS TEST?But the area of controversy is in testing for VUR. Essentially, Nguyen said, pediatricians are increasingly moving away from recommending VUR testing for children with urinary tract infections.Pediatricians, he noted, see a lot of children with UTIs, and most of those kids will have no long-term kidney disease as a result. But urology specialists see the people with chronic kidney disease, and they are apt to see the value in testing for VUR so that kids with reflux can be treated.“We are looking from two different viewpoints,” Nguyen said.VUR has a strong genetic component, and researchers are working on gene tests – where a child will just have to “spit in a cup,” Nguyen said – that could help pinpoint the kids with UTIs who would be the best candidates for VUR testing.For now, the decision to do VUR testing is basically case-by-case.Dr. John Gearhart, director of pediatric urology at Johns Hopkins Children’s Center in Baltimore, said the current findings “should reassure mothers and fathers."But he agreed that there are cases where testing for VUR is appropriate: if there’s a family history of the condition, for example, or if a young child has more than one urinary infection that includes fever.Testing for VUR does involve radiation, albeit as low a dose as possible, Gearhart noted in an interview. So limiting the number of children who have it is important.There can also be side effects from the low-dose antibiotics given to children with VUR – such as stomach upset, diarrhea and yeast infections.There is an ongoing North American clinical trial looking at whether giving antibiotics to young children with mild to moderate VUR prevents kidney scarring (which, down the line, might contribute to chronic kidney disease).That, according to Gearhart, should give more insights into whether it is helpful to give all children with VUR preventive antibiotics.


Infections damage our ability to form spatial memories

Increased inflammation following an infection impairs the brain’s ability to form spatial memories – according to new research. The impairment results from a decrease in glucose metabolism in the brain’s memory centre, disrupting the neural circuits involved in learning and memory.

Inflammation has long been linked to disorders of memory like Alzheimer’s disease. Severe infections can also impair cognitive function in healthy elderly individuals. The new findings published in the journal Biological Psychiatry help explain why inflammation impairs memory and could spur the development of new drugs targeting the immune system to treat dementia.

In the first trial to image how inflammation impairs human memory, the team at Brighton and Sussex Medical School scanned 20 participants before and after either a benign salty water injection or typhoid vaccination, used to induce inflammation. Positron emission tomography (PET) was used to measure the effects of inflammation on the consumption of glucose in the brain and after each scan participants tested their spatial memory by performing a series of tasks in a virtual reality.

A reduction in glucose metabolism within the brain’s memory centre, known as the Medial Temporal Lobe (MTL), was seen following inflammation. Participants also performed less well in spatial memory tasks, an effect that appeared to be directly mediated by the change in MTL metabolism.

“We have known for some time that severe infections can lead to long-term cognitive impairment in the elderly. Infections are also a common trigger for acute decline in function in patients with dementia and Alzheimer’s disease,” explains Dr Neil Harrison, a Wellcome Trust Intermediate Clinical Fellow at BSMS who led the study. “This study suggests that catching a cold or the flu, which leads to inflammation in the brain, could impair our memory.”

Infections are unlikely to cause long-term detrimental impact in the young and healthy but the findings are of great significance in the elderly. The team now plan to investigate the role of inflammation in dementia, including insight into how acute infections such as influenza influence the rate of progression and decline.

“Our findings suggest that the brain’s memory circuits are particularly sensitive to inflammation and help clarify the association between inflammation and decline in dementia,” says Dr Harrison. “If we can control levels of inflammation, we may be able to reduce the rate of decline in patients’ cognition.”

A Map for U.S. Travelers Who Want to Avoid Infections

Despite the progress we’ve made in vaccines, drugs, and sanitation, infectious diseases—a category that includes everything from the run-of-the-mill flu to antibiotic-resistant “superbugs"—still kill some 170,00 Americans each year.

But most states—33, to be exact—have taken fewer than half of the recommended steps to prevent the spread of things like whooping cough, HIV, and hospital infections, according to a new report the Trust for America’s Health, a nonprofit that works to prevent outbreaks, and the Robert Wood Johnson Foundation, a public health philanthropy.

Read more.

Rats of New York and the diseases they carry

In the first study to look at would-be diseases carried by New York City rats, scientists at the Center for Infection and Immunity at Columbia University’s Mailman School of Public Health identified bacterial pathogens, including E. coli, Salmonella, and C. difficile, that cause mild to life-threatening gastroenteritis in people; Seoul hantavirus, which causes Ebola-like hemorrhagic fever and kidney failure in humans; and the closest relative to human hepatitis C. Results appear in the journal mBio.

The researchers trapped 133 Norway rats at 5 sites in New York City, focusing on rats trapped inside residential buildings. In the lab, targeted molecular assays confirmed the presence of 15 of the 20 bacterial and protozoan pathogens they looked for and one virus: Seoul hantavirus was present in eight rats. It is the first time the virus has been documented in New York City, and genetic clues suggest that it may be a recent arrival. Human infection has been associated with multiple cases of hemorrhagic fever with renal syndrome, and chronic renal disease in Maryland and Los Angeles. The virus has also been implicated in cases of hypertension.

“New Yorkers are constantly exposed to rats and the pathogens they carry, perhaps more than any other animal,” explains Dr. Firth, who conducted the study as a research scientist at Columbia’s Center for Infection and Immunity. “Despite this, we know very little about the impact they have on human health. ”

My worst module this year is definately infection and immunity.

Ugh.

There is just so much of it. It takes me hours and hours to go through the lectures and by the time I’ve finished all the work for the week, monday rolls around again and we get more lectures and work. Fun :p

Anyway- The picture above is of  the HIV virus. HIV infects CD4+ T cells (T helper cells) and leads to low levels of them which means that cell mediated immunity is impaired and people with the virus are susceptible to infections.

HIV Treatment Lags In U.S., Guaranteeing More Infections : Shots

The CDC director outlined a cascade of shortcomings that explain why the vast majority of HIV-positive Americans are untreated or under-treated:

  • Twenty percent of them have not been tested, so their HIV infection is unknown to themselves or their doctors.
  • Nearly 40 percent of the total — and half of those who’ve been diagnosed as HIV-positive — have not been linked up with HIV care.
  • Sixty percent of those who enter care drop out.
  • Only a third of all HIV-infected people get anti-retroviral therapy.
  • Some people who get the drugs don’t achieve control of the virus.