From: matthew@ooc.uva.nl (Matthew Lewis)
Subject: Conference newspaper - Friday 24 July - part 1
Note: non-commercial reproduction.
Archive-Number: 5784
Organization: Center for Innovation and Cooperative Technology, University of Amsterdam
Date: 26 Jul 92 17:15:49 GMT

Hello all,

My apologies for the lateness of this one.  We were all suffering 
from post-conference collapse (with a small measure of post-Act Up 
party collapse :-)  So......

Here is the conference newspaper, Friday 24 July.  This paper 
comes to you courtesy of HIVNET, a Dutch organisation that has set 
up a network of BBS systems to spread information about HIV and 
AIDS.  The paper is available due to the kind cooperation of the 
Aids Congress Foundation.

*********************************************************
CDC will check new 'virus'
By Janis Kelly

Reports of odd immunodeficiencies in patients not infected with 
either HIV-1 or HIV-2 have led Dr James Curran of the Centers for 
Disease Control in Atlanta to ask all doctors with such cases to 
report them to the CDC. Along with Dr Michael Merson, head of the 
WHO Global Programme on AIDS, Curran wants an international 
meeting of all those who have worked on such cases. According to 
Curran, these cases need to be explored thoroughly, including 
investigating "the patient, the family, and the whole 
neighbourhood" to rule out other causes of the immuno-deficiency. 
Curran says several questions remain to be answered, including 
whether the supposed new virus is real, whether it causes disease 
and whether it can be transmitted. 
Retrovirus
Curran's move was in response      to descriptions of 11 cases by       
Dr David Ho of the Aaron Diamond AIDS Research Center in the US 
and to a forthcoming article in the Proceedings of the National 
Academy of Sciences, USA  by       Dr Sudhir Gupta of the University 
of California at Irvine. 
Gupta's team claims to have identified a new retrovirus in a woman 
with severely weakened immunity and opportunistic infections. 
Tests on her cells showed that reverse transcriptase was present, 
as in 4 of the 11 cases Ho has described.
However, Dr Max Essex of the Harvard School of Public Health in 
the US and Dr Gerald Myers, of Los Alamos National Laboratory in 
the US, both questioned Gupta's conclusions. Essex said that what 
Gupta described should be called a "virus-like particle". It has not 
been proven to be a virus, he said. 
Essex added that similar particles have been reported in several 
dozen cases over the past 20 years and that no such particle has 
ever been shown to cause disease. Myers said that the particle 
might be only a "retroid" - a fragment produced by a bit of a normal 
human gene that resembles a virus gene sequence. Many different 
events can trigger cells to make them.  
Such fragments are quite common in ordinary human cells. Myers 
said that most people carry around "hundreds of thousands" of such 
retroids; they are the main "junk" interfering with the international 
project to sequence the human genome.
*********************************************************
   
Apoptosis: cause of CD4 loss?
By Wim Zeijlemaker

Apoptosis, or programmed cell death, may be responsible for the 
massive loss of CD4 cells during the progression of HIV infection, 
scientists said at Wednesday's session on the mechanisms of 
immunopathology. Apoptosis is a complex and regulated process in 
which a cell destructs by its own mechanisms.
A longitudinal study of HIV seropositives showed that CD4 cell 
function decreased before large numbers of them were lost, said 
Linde Meyaard and Frank Miedema of the Netherlands. During 
treatment with AZT a significantly lower proportion of both CD4 
and CD8 cells showed apoptosis, they said. The exact mechanism 
leading to the apoptosis associated with HIV infection is yet to be 
determined.
*********************************************************
Low tech solutions for poor countries
By Cindy Patton

Developing countries spend about US$5 per capita on health care, 
leaving little money for diagnostic tests for STDs, said Peter Wayaiki 
of the Kenya Medical Research Institute yesterday. Tests are either 
too expensive or require heavy investment in machinery in order to 
complete them, Wayaiki said. In addition, it is difficult for 
commercial firms to market cheap tests - even when they exist - in 
developing countries.
To help solve this problem, the American consulting firm PATH 
created the STD diagnostic network. Milton Tam, from PATH, said 
the project collaborates with the WHO's Global Programme on AIDS 
to develop bulk buying of tests and identify novel tech-nologies 
which can be developed into extremely cheap tests for use in poor 
countries. The network aims for tests which cost less than US$1 
each. 

Gravity
Instead of using high-technology solutions, plasma separation 
techniques use good old gravity. One such device, which the US 
Army wants to purchase, uses heparin and salts on a card which is 
folded and left to stand for 10 minutes while the plasma "trickles 
down". There is also a hand-held centrifuge which works like a 
child's toy with a disc on strings which can be spun round. This 
produces good results in about five minutes. In addition, the 
network is developing better tests for Chlamydia and gonorrhoea 
since even those used in developed countries are not as effective as 
they could be. 
*********************************************************
Circumcision protects against HIV

A study of Kenyan truck drivers suggests that circumcision protects 
against HIV transmission. Job Bwayo from the University of Nairobi 
in Kenya, who conducted the study, said neonatal circum-cision 
should be promoted in countries where this procedure is culturally 
acceptable. A survey of a group of almost 1,000 truck drivers found 
that 37% of those who were HIV-positive were not circumcised, 
compared to 12% of those who were HIV-negative. Uncircumcised 
status was associated with a five-fold increased risk of HIV 
infection, Bwayo said. The absence of circumcision was, among 
other factors, the strongest predictor of HIV-positivity.
The truck drivers were interviewed on the main highway from the 
port of Mombasa to Nairobi between June 1989 and February 1992. 
Half of them came from Kenya, the rest from Uganda, Rwanda or 
other African countries. Blood was drawn to establish their 
serostatus; 27% were HIV-positive. This figure corresponds with 
other African studies on truck drivers, Bwayo said.
Truck drivers are often thought to play an important role in the 
African epidemic because of their mobility and high number of 
sexual partners. The interviews showed that 75% of the truck 
drivers had regular sex with prostitutes, on average twice a month. 
HIV-positive drivers had sex with prostitutes more frequently than 
those who were HIV-negative. Only 40% of the truck drivers used 
condoms, despite the fact that 93% believed they prevented HIV. 

*********************************************************
Breast feeding is more risky just after birth 
By Janis Kelly and Cindy Patton

HIV can be transmitted via breast milk, studies presented at this 
week's meeting have confirmed. But because the risk of 
transmission to the child is greatest during the first few weeks 
after birth, delaying breastfeeding for a few weeks may help to 
reduce transmission. 
HIV-1 DNA was detected in breast milk more frequently during the 
first 14 days after birth than in subsequent weeks, and the risk of 
transmission was highest when the DNA level was high, according 
to Dr Marc Bulterys of the University of Rwanda in Butare. Work by       
Dr Andrea Ruff from an AIDS project in Haiti showed that one in 
four children become infected if there is viral DNA in the breast 
milk but only one in 10 if there is no viral DNA in the breast milk 
when it is tested with the polymerase chain reaction.  
Dr Philippe Van de Perre of the National AIDS Control Programme 
in Kigali, Rwanda, said that the risk of infection decreases when 
the levels of anti-HIV IgM antibodies in the breast milk rise. Van de 
Perre suggested that this might be either a direct effect on viral 
transmission or a marker for a related event. 

Mystery
The recent recommendations from the WHO that HIV-positive 
women in areas where infectious diseases are a primary cause of 
infant death should continue to breast feed, while those who live 
elsewhere should not breast feed, has caused a great deal of 
concern among maternal and child health workers. 
Transmission of HIV from mother to child can also happen in 
utero, or during labour and delivery. The question of exactly how 
the virus infects a foetus in utero is still something of a mystery, but 
Dr Eva Maria Fenyo of Sweden's Karolinska Institute said studies 
had shown that HIV-infected women with low CD4 counts, HIV 
antigenaemia, antibody responses to specific HIV peptides, and 
neutralization antibody responses are at greater risk of having an 
infected child than those who do not. Dr Arye Rubinstein from 
Albert Einstein College of Medicine in New York, US, believes that 
many of the children ostensibly infected during labour and delivery 
are, in fact, cases of infection in utero. In previously unpublished 
data, Rubinstein showed cases in which peripheral blood (cord 
blood) samples were negative for HIV by every known laboratory 
test, but virus could be isolated from foetal tissues.  Rubinstein said: 
"Lack of culturability or PCR positivity at birth does not necessarily 
mean that transmission occurred perinatally or at birth."  

Testing infants
Recent advances in HIV detection in infants may change ethical 
considerations about testing newborns, participants heard 
yesterday at a session on women and reproductive rights. Until 
recently, clinicians and parents had to wait for up to two years 
before they could determine whether a positive antibody test result 
represented true infection or merely the presence of maternal 
antibody. 
Polly Thomas of the New York City Department of Public Health, 
said newer techniques now enable clinicians to determine an 
infant's true serostatus within six months. 
Improved survival rates linked to early prophylactic administration 
of Bactrim and intravenous penta-midine in infants means that early 
testing gives infants additional advantages, at least in badly hit 
urban centres like New York City, Thomas said. 
Ronald Bayer, an ethicist from Columbia University in the US, said 
these two medical advances mean that clinicans now have to 
reconsider policies on routine testing of infants. 

Psychological pressure
The original decision to discourage routine testing had been taken 
because it avoided the extreme psychological pressure on the 
mother while waiting to find out if the child really was infected, 
and to avoid discrimination towards the child. Children waiting for 
adoption are frequently kept in hospital until they can be shown to 
be HIV-negative. 
*********************************************************
Protease inhibitors are on the way
By Wim Zeijlemaker

Protease inhibitors are attracting intense interest as potential drugs 
for the treatment of AIDS. Several laboratories have shown recently 
that inhibiting the activity of the HIV protease enzyme can prevent 
the production of infectious virus by cells in vitro. The enzyme 
cleaves large precursor proteins into smaller molecules which form 
the mature virus. Inhibiting  the enzyme therefore prevents the 
assembly of new viral particles.
The clinical evaluation of protease inhibitors has been hampered by 
their poor bioavailability and the difficulty of producing 
preparations that maintain their activity in the blood stream. 
At yesterday's session on Protease Inhibitors, scientists from five 
pharmaceutical companies pre-sented their latest data on this 
topic. Chemicals called C2-symmetrical diols appear to be 
particularly useful. 
Daniel Norbeck, of Abbott Laboratories in the US, successfully 
tackled the bioavailability problem by systematic chemical modi-
fication of the diol compounds; in rats, dogs and monkeys, plasma 
levels were reached that were well above the concentration that 
could inhibit the virus in vitro. Dr Sven Danner is starting a clinical 
trial of one new compound, designated      A-80987, which can be 
given by mouth, at the Academic Medical Centre in Amsterdam. 
As with any new antiviral agent, a serious concern is the 
development of viral resistance to the compound. Michael Otto, of 
DuPont in the US, showed that viral variants resistant to protease 
inhibitors do occur. Catherine Patterson, also from DuPont, 
reported that this loss of susceptibility is caused by a single point-
mutation. 
Dr Janus Lazdins, of Ciba-Geigy, Switzerland, made a plea in his 
summing-up of the session, for pharmaceutical companies to be 
more open. This may have been the cause of the slow progress in 
this area, he said. He emphasized that protease inhibitors will 
undoubtedly be used in combination with drugs such as zidovudine, 
which will make the development of resistant variants less likely.  
Although it will be several years before we will know the effect of 
these compounds on the viral load in AIDS patients, Lazdins 
expressed optimism: protease inhibitors look like an important 
new opening, he said.  
*********************************************************

-- 
Matthew Lewis, University of Amsterdam		Grote Bickersstraat 72
+31-20-52 51 220				1013 KS  Amsterdam
Internet: matthew@ooc.uva.nl			The Netherlands
Newsgroups: sci.med.aids