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This mother chimp is SIV positive
The origin of HIV has been found in wild chimpanzees living in southern Cameroon, researchers report.
A virus called SIVcpz (Simian Immunodeficiency Virus from chimps) was thought to be the source, but had only been found in a few captive animals.
Now, an international team of scientists has identified a natural reservoir of SIVcpz in animals living in the wild.
The findings are to be published in Science magazine.
All discoveries which relate to the history and origins of HIV could be of value to the vital work being carried out by scientists in developing a HIV vaccine
Yusef Azad, National Aids Trust
It is thought that people hunting chimpanzees first contracted the virus - and that cases were first seen in Kinshasa, in the Democratic Republic of Congo - the nearest urban area - in 1930.
Scientists believe the rareness of cases - and the fact that symptoms of Aids differ significantly between individuals - explains why it was another 50 years before the virus was named.
This team of researchers, including experts from the universities of Nottingham, Montpellier and Alabama, have been working for a decade to identify the source of HIV.
While SIVcpz was only identified in captive animals, the possibility remained that yet another species could be the natural reservoir of both HIV and SIVcpz.
Gene tests
It had only been possible to detect SIVcpz using blood test - which meant that only captive animals could be studied.
This study, carried out alongside experts from the Project Prevention du Sida au Cameroun (PRESICA) in Cameroon, involved analysing chimpanzee faeces, collected from the forest floor in remote jungle areas.
The researchers went into the jungles of Cameroon
This was useful because University of Alabama at Birmingham researchers had been able to determine the genetic sequences of the chimpanzee viruses - which could then be searched for in the faecal samples.
Lab tests detected SIVcpz specific antibodies and genetic information linked to the virus in up to 35% of chimpanzees in some groups.
All of the data were then sent to the University of Nottingham for analysis, which revealed the extremely close genetic relationship between some of the samples and strains of HIV.
Chimpanzees in south-east Cameroon were found to have the viruses most similar to the form of HIV that has spread throughout the world.
The researchers say that, as well as solving the mystery about the origin of the virus, the findings open up avenues for future research.
But SIVcpz has not been found to cause any Aids-like illnesses in chimpanzees, so researchers are investigating why the animals do not suffer any symptoms, when humans - who are so genetically similar - do.
Close relation
Paul Sharp, professor of genetics at the University of Nottingham said: "It is likely that the jump between chimps and humans occurred in south-east Cameroon - and that virus then spread across the world.
"When you consider that HIV probably originated more than 75 years ago, it is most unlikely that there are any viruses out there that will prove to be more closely related to the human virus."
He said the team were currently working to understand if the genetic differences between SIVcpz and HIV evolved as a response to the species jump.
Keith Alcorn of Aidsmap said: "The researchers have pinned down a very specific location where they believe the precursor of HIV came from.
"But there are vast areas of west Africa where other forms of SIVcpz lineages exist, and the possibility remains for human infection.
Yusef Azad, policy director of the National Aids Trust said: "This research is interesting as all discoveries which relate to the history and origins of HIV could be of value to the vital work being carried out by scientists in developing a HIV vaccine."
Cognitive therapy improves irritable bowel syndrome
Last Updated: 2006-05-25 16:40:49 -0400 (Reuters Health)
By Martha Kerr
LOS ANGELES (Reuters Health) - Four sessions of cognitive behavioral therapy, combined with a take-home workbook, result in a greater than 70 percent improvement in symptoms of irritable bowel syndrome (IBS) compared with patients relegated to a waiting list, according to a study presented at Digestive Disease Week 2006 here this week.
Dr. Jeffrey M. Lackner, of the State University of New York at Buffalo , and colleagues randomly assigned 59 patients with irritable bowel syndrome to one of three treatments.
Patients in the first group received 10 sessions of standard cognitive behavioral therapy. Patients in the second group received 4 sessions of minimal contact cognitive therapy but with minimal contact, and were given a self-help workbook to take home. Patients in the third group were placed on a waiting list.
The researchers conducted follow-up visits to evaluate symptoms after 4 and 10 weeks.
In general, cognitive behavioral therapy emphasizes the patient's thought process and how it influences feelings and actions. The therapy is usually short-term, focusing on the development of coping skills using a structured, goal-oriented and individualized approach.
In the study, patients were taught how to manage fear, worry and anxiety, stressors that aggravate symptoms. "We're not shrinking heads here," Lackner told meeting attendees. "We gave patients practical tips on how to manage their symptoms, just as is done in cardiac rehab."
At the end of the study period, symptoms of irritable bowel syndrome had improved by approximately 73 percent in patients who received cognitive therapy, while patients on the wait list had no improvements.
Pain relief was also reported in approximately 73 percent of patients in both cognitive therapy groups compared with 11.8 percent in wait-listed patients. Gastrointestinal symptoms improved by 63.6 percent and 68.4 percent in those on the 4-week and 10-week sessions, respectively.
Patients in the minimal contact cognitive therapy group reported significant improvements in quality of life, and unlike those who received 10 weeks of therapy, "they are continuing to improve," Lackner said. Those who received the 10-week course have merely maintained their gains.
Minimal contact cognitive therapy was 2.5 times more efficient than the 10-week standard course and placed a 60-percent lower demand on therapists. Short-course therapy was also about 5.0 times as efficient in a cost-effectiveness analysis.
Lackner attributes the continued improvement to ongoing practice of the techniques the patients learned, assisted by the workbook.
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