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Monthly Archives: August 2016

Lap band surgery benefits

Lap band surgery has significant benefits for severely obese teenagers and, despite its controversial nature, should still be considered as a first option to manage obesity during adolescence, a new study has found.

Led by University of Adelaide researchers, in collaboration with Flinders Medical Centre, and published in the journal Obesity Surgery, the study is the first to show medium to long-term follow-up (3-5 years) of lap band surgery in Australian adolescents.

The research followed 21 severely obese teenagers between 14 and 18 years who had Laparoscopic Adjustable Gastric Banding (lap band surgery) in the South Australian Health Service.

Severe obesity is associated with serious physical and psychological conditions affecting quality of life. Australian revised National Health and Medical Research Council guidelines for obesity management say that lap band surgery should be considered in adolescents with severe obesity — that is with a body mass index (BMI) over 40 kg/m2 or over 35 kg/m2 (weight/height2) with the presence of obesity-related diseases and who don’t respond to medical treatment. However there is no data available in Australian adolescents beyond 24 months post-surgery.

“We are talking about a group of adolescents with severe obesity and significant health and psychological problems related to their increased weight — this is not for everyone,” says corresponding author and Paediatric Endocrinologist Dr Alexia Peña, who is a Senior Lecturer with the University of Adelaide’s Robinson Research Institute.

The study found that weight and BMI improved significantly at all follow-up times following surgery from three months through to 45 months and, in some cases, as long as five years. BMI loss was between 7.1 and 14.7 kg/m2.

“The median BMI reduction of 10 kg/m2 with the lap band is a good result when compared to BMI reduction using the few medications available or lifestyle measures, which is around 1-3 kg/m2,” says Dr Peña. “Lap band surgery is reversible and allows time for adolescents to mature to make a more informed decision on a permanent surgical procedure if required later on in life. This is not the case for other surgeries currently offered for obesity management.

“It is also important that teenagers undergoing this surgery have access to an experienced surgeon as part of a multidisciplinary paediatric team of doctors and Health professionals to ensure there is long-term regular follow-up.”

Paediatric surgeon Mr Sanjeev Khurana, who did all the lap band surgeries between 2009 and 2013, says lap band surgery is a reversible surgical procedure that can be safely used in teens with severe obesity.

“Although gastric banding has been controversial and is currently less used in adults with severe obesity, lap band surgery is one of the most studied surgeries for obesity management, has a high safety record and can be a temporary option to manage severe obesity during adolescence,” says Mr Khurana, who is also a Senior Lecturer in the University of Adelaide’s Discipline of Paediatrics.

“Our findings support lap band surgery as a safe and effective option for management of adolescents with severe obesity — provided it is performed by an experienced surgeon and managed afterwards in a paediatric multidisciplinary environment with regular follow-up until adulthood.”

Person-to-person contact may cause most drug-resistant TB

 The worst form of drug-resistant tuberculosis isn’t just arising from inadequate treatment, it’s mostly being spread from person to person, according to a new study of hundreds of cases in South Africa that has important implications for how the deadly disease is treated.

Researchers tracked TB that is resistant to at least four key drugs and found that 69 percent of the victims had never received treatment, an indication that they had acquired it from others with extensively drug-resistant TB.

TB develops resistance to drugs when it is attacked with lackluster therapy, allowing the slow-growing bacterium to become insensitive to well-established therapies. Strains that are simultaneously resistant to at least four drugs have been reported in 105 countries.

“For many years, there was this thought that maybe drug-resistant TB strains might not be able to be transmitted as efficiently a regular TB strains,” coauthor Dr.. Neel R. Gandhi of Emory University’s Rollins School of Public Health in Atlanta told Reuters Health by phone.

The results published in the New England Journal of Medicine “turn this idea on its head,” said Dr. William Schaffner, professor of infectious disease at Vanderbilt University Medical Center in Atlanta who was not involved in the research.

The study team’s estimate that two thirds of the cases are surfacing because the disease is spreading by person-to-person contact “is mostly likely a minimum estimate,” Gandhi said.

“This is an epidemic we’ve known about for 10 years and we don’t seem to be making a dent in it,” he said. “And that may be because the driver isn’t what we thought it was.”

“It raises the possibility of turning the clock back to the 1930s and 1940s” and requiring infected people to live in sanitariums so patients can’t inadvertently spread the disease, Schaffner said. “You also have to do better at diagnosing them earlier. We’re going to have to be a lot more aggressive in finding the infected people early. These are substantial public health challenges.”

Drug resistance has gotten so bad, the rate of successful treatment can be less than 40 percent if a person acquires an extensively drug-resistant strain. It can be particularly deadly in people who also harbor HIV, the AIDS virus. In South Africa, where the new study was done, there has been a 10-fold increase in the number of extensively drug-resistant cases in the past decade. One in 36,000 are now infected.

The team of researchers used contact tracing to find where the TB patients were spending at least two hours per week, trying to uncover any links.

They found 31 clusters of the disease, the largest of which accounted for 84 percent of the 404 patients they studied.

Living with someone with TB accounted for most of the acquired cases, although the disease was also spread in the workplace (representing 13 percent of cases) or in other community settings such as a church, bar, beauty salon or prison (accounting for 8 percent of cases).

“Certain networks spanned multiple homes, family generations, and community settings,” the study team writes.

Complicating control is that people can be infectious before they know they have drug-resistant TB.

“We know people transmit (the disease) for weeks or months before they come for a diagnosis,” said Gandi, an associate professor of epidemiology, global health and infectious diseases at Emory.

“You have to focus on stopping the chain of transmission,” he said. “You have to identify early and intervene early. When you diagnose, drug susceptibility should be part of that diagnosis. And we have to do a better job creating facilities where transmission doesn’t take place, particularly in healthcare settings, hospitals, homeless shelters in the United States and in schools and workplaces.”

The other researchers involved in the study were from the U.S. Centers for Disease Control and Prevention in Atlanta, the Albert Einstein College of Medicine in New York and the University of KwaZulu-Natal in South Africa, the province of 10.3 million people where the study was done.

Bed Bugs Can Bypass Pitfalls of Inbreeding

Bed Bugs Cincinnati

 Bed bugs appear to breed with their close relatives, an adaptation that not only ups their “yuck” factor but also enhances the tiny bloodsuckers’ ability to thrive, two new studies find.

Entomologists from North Carolina State University did a genetic analysis of bed bugs taken from infested apartment buildings in North Carolina and New Jersey. Their analysis showed the bugs had low genetic diversity, meaning that close relatives had mated with one another.

In most species, breeding with close relatives means genetic mutations accumulate, and offspring are more likely to be sickly or infertile, which hurts the species over time, explained study author Coby Schal, a professor of entomology. Yet, inbreeding doesn’t seem to bother bed bugs.

Just one “mated” female could be enough to start a nasty infestation, because her offspring will mate with each other, and so on. In the North Carolina building, for example, about one-quarter of about 90 apartments had bed bugs.

“Infestations are generally founded by just one female, and the fact is that theinfestation can sweep through a building because the bed bugs are able to withstand inbreeding,” Schal said. “We don’t understand the genetic mechanism that allows them to do that, but it’s not uncommon among insects associated with humans, especially those that don’t fly, such as cockroaches.”

In a second study, the researchers analyzed the genetic make up of bugs from 21 infestations in households from Maine to Florida, and also found evidence of inbreeding.

The research was to be presented Tuesday at the American Society of Tropical Medicine and Hygiene (ASTMH) annual meeting in Philadelphia.

After nearly vanishing by the 1950s, bed bugs now show up in homes, hotels and dorm rooms throughout the United States and the world, experts said. The explanation for their re-emergence isn’t fully understood, but it’s suspected that the bugs have developed a resistance to the pesticides used to kill them. Those pesticides include pyrethroids, commonly found in cans of insect spray, and DDT, which is banned in the United States but still used in other countries, Schal said.

A third study to be presented at the meeting, by researchers from University of Kentucky, found that killing resistant bed bugs takes 10,000 times more pyrethroid insecticide than destroying a strain of bed bugs never exposed to the insecticide.

The good news is bed bugs are not known to carry disease, although some people can have allergic reactions, said Dr. Peter Hotez, president of ASTMH. “While it’s an annoyance, there shouldn’t be cause for alarm,” he said.

More research is needed to confirm the inbreeding findings and the theory that pesticide resistance is to blame for the resurgence, Hotez said. But, “if you have insecticide resistance and inbreeding, those two findings suggest we could be looking at larger bed bug problem in the coming months and years,” Hotez said.

Though often associated with unsanitary conditions, bed bugs aren’t attracted to dirt, experts said. They are more likely to be found in poorer buildings, but that’s likely because of lack of resources to pay for expensive extermination, Schal said.

Fumigation with pesticides can eradicate bed bugs from a building, but it may take multiple efforts because of resistance, Schal said. Another technique involves sealing off a building and heating the interior to between 120 and 130 degrees, which kills the bugs and their eggs. But that can be costly and requires specialized equipment, he said.

Adult bed bugs are reddish-brown and oval-shaped. Before feeding, the adult bed bug is relatively flat. After feeding, it becomes a darker red.

During the day, they hide in cracks and crevices, box springs and mattress seams. At night, they come out to feed. “If they’re hungry, they will bite pets, but they much prefer humans,” Schal said.

Bed bug mating — known as “traumatic insemination” — is “quite an amazing story,” Schal said. Males pierce the body of a female and insert sperm into her bloodstream, where it seeks out a sperm storage organ. She can keep it there for weeks before using it to fertilize her eggs, which she’ll lay at a rate of about one a day.

“It doesn’t matter if they are brother and sister, or mother and son, they can mate and start a whole new population,” he said.

In other research to be presented at the meeting, researchers said they’re learning more about bed bugs’ “alarm pheromones,” which, when sensed by the bugs, cause them to run away. Presumably, alarm pheromones could be used to send bed bugs scurrying toward insecticides, researchers said.

Because the research was presented at a medical meeting, the conclusions should be viewed as preliminary until published in a peer-reviewed journal.

A new approach to medical implants

 Medical implants like stents, catheters and tubing introduce risk for blood clotting and infection — a perpetual problem for many patients.

Colorado State University engineers offer a potential solution: A specially grown, “superhemophobic” titanium surface that’s extremely repellent to blood. The material could form the basis for surgical implants with lower risk of rejection by the body.

It’s an outside-the-box innovation achieved at the intersection of two disciplines: biomedical engineering and materials science. The work, recently published in Advanced Healthcare Materials, is a collaboration between the labs of Arun Kota, assistant professor of mechanical engineering and biomedical engineering; and Ketul Popat, associate professor in the same departments.

Kota, an expert in novel, “superomniphobic” materials that repel virtually any liquid, joined forces with Popat, an innovator in tissue engineering and bio-compatible materials. Starting with sheets of titanium, commonly used for medical devices, their labs grew chemically altered surfaces that act as perfect barriers between the titanium and blood. Their teams conducted experiments showing very low levels of platelet adhesion, a biological process that leads to blood clotting and eventual rejection of a foreign material.

A material “phobic” (repellent) to blood might seem counterintuitive, the researchers say, as often biomedical scientists use materials “philic” (with affinity) to blood to make them biologically compatible. “What we are doing is the exact opposite,” Kota said. “We are taking a material that blood hates to come in contact with, in order to make it compatible with blood.” The key innovation is that the surface is so repellent, that blood is tricked into believing there’s virtually no foreign material there at all.

The undesirable interaction of blood with foreign materials is an ongoing problem in medical research, Popat said. Over time, stents can form clots, obstructions, and lead to heart attacks or embolisms. Often patients need blood-thinning medications for the rest of their lives — and the drugs aren’t foolproof.

“The reason blood clots is because it finds cells in the blood to go to and attach,” Popat said. “Normally, blood flows in vessels. If we can design materials where blood barely contacts the surface, there is virtually no chance of clotting, which is a coordinated set of events. Here, we’re targeting the prevention of the first set of events.”

The researchers analyzed variations of titanium surfaces, including different textures and chemistries, and they compared the extent of platelet adhesion and activation. Fluorinated nanotubes offered the best protection against clotting, and they plan to conduct follow-up experiments.

Growing a surface and testing it in the lab is only the beginning, the researchers say. They want to continue examining other clotting factors, and eventually, to test real medical devices.