Mann was due to leave the WHO on 14 June, after resigning over differences
with the director-general, Hiroshi Nakajima (This Week, 24 March). Last
week, Nakajima’s staff told Mann to clear his office. Nakajima must decide
soon whether the WHO will continue to support the conference despite American
restrictions on visas for travellers infected with HIV. In 1987, Congress
voted to include carriers of HIV on a list of people with communicable diseases
who may be refused US visas.

Members of the WHO, including the US, have condemned such restrictions.
They say they would not protect public health, and undermine human rights.
Mann called for the WHO to withdraw support for the conference if the rule
was not changed.

The US Attorney General this year granted 30-day waivers of the exclusion
to travellers who admit that they are infected when they apply to officials
for a visa. Waivers are granted if people want to visit immediate family,
participate in research, do business, or attend either the conference in
San Francisco or the World Haemophilia Congress in August in Washington
DC. The waiver of a health restriction was coded on the visa with a number
six, a mark invariably interpreted, says Terry Mooney of the WHO, as meaning
the holder had AIDS.

Mervyn Silverman, president of the American Foundation for AIDS Research,
says the number is like putting ‘a pink triangle on people’. (These marked
out homosexuals in concentration camps of the Second World War.) Recently
the US has issued visas, and waivers, on separate paper. The US will do
this if the HIV-positive traveller asks.

Last November the International Committee of the Red Cross withdrew
from the conference pending changes to the restrictions. This week its head,
Pars Stenback, maintained that position because the revisions in US policy
are temporary.

The European Parliament called in January for Community scientists and
governments to boycott the San Francisco conference unless the US restrictions
changed. France has backed the calls. Last month, the executive board of
the International AIDS Society (IAS), which includes leading AIDS researchers,
‘strongly condemned’ the restrictions and said it would support the San
Francisco conference only if changes are made. Lars Kallings, IAS president,
says he ‘would find it sufficiently positive’ if President Bush strongly
recommended that Congress change the law.

Last week President Bush publicly condemned discrimination against carriers
of HIV, but made no mention of the law. Silverman called this the ‘biggest
disappointment’ in the speech. Officials at the US State Department and
public health service say no change can be made without the approval of
Congress.

Since December, the US Justice Department has been working to arrange
binding arbitration between the National Institutes of Health (NIH) and
the animal rights group, People for the Ethical Treatment of Animals (PETA),
over the fate of the monkeys. According to people involved in the negotiations,
PETA is offering to give up objections to experimentation on the animals
at the end of their lives if the monkeys are transferred out of NIH control.
A panel of vets picked by both groups would arbitrate.

ÐÓ°ÉÔ­´´s had cut nerves to the monkeys’ arms in 1979 during an experiment
designed to help them investigate methods for accelerating recovery from
strokes. The six monkeys, and one normal monkey, are the remaining members
of a group of nine that became known as the ‘Silver Spring monkeys’ after
the city near Washington DC where the experiments were carried out.

The Silver Spring monkeys became a cause celebre among animal rights
groups after activists collected information that led to a police raid on
the laboratory in 1981. Some of the animals have been in pain for years
as a result of the original nerve damage, and the NIH has long argued that
the animals were never intended to live so long and should have been put
down long ago. Activists at PETA have blocked such an action in a case that
is due to be decided in the near future in federal court.

Ironically, the nine years that the Silver Spring monkeys have been
kept in legal limbo has made possible an important and ‘completely unexpected’
discovery, according to NIH scientists. One monkey, Billy, was in such pain
and so close to dying that the courts allowed euthanasia.

During euthanasia, after Billy was under anaesthesia, Timothy Pons,
a scientist working at the NIH, probed the area of the brain that should
be used to sense touching on Billy’s arms, while brushing different parts
of the monkey’s body.

Pons found that the 8- to 10-millimetre area of the brain under study
had been completely reorganised to receive input from the face. ‘We always
thought such reorganisation was limited, but this finding seems to say that
isn’t so,’ Pons says.

David Hubel, a neurophysiologist at Harvard University who won a Nobel
prize for medicine, agreed that the finding ‘seems quite significant’. When
experiments of this sort have proceeded for a year or so scientists usually
find some regions of the brain that have become unresponsive, and limited
traces of neural reorganisation, he said. ‘This huge reorganisation has
great implications for neurological rehabilitation in humans,’ Hubel said.
‘It suggests more rehabilitation is possible than previously thought.’

Hubel pointed out that it was a fluke that such an experiment was possible,
because none of the committees that approves experiments would ever have
allowed the animals to live in pain for 10 years. ‘Not to have done the
experiment would have been a real waste,’ he says.

Alex Pacheco, the head of PETA disagreed: ‘We’re convinced this is a
fraudulent fabrication of an experiment and a face-saving device for this
whole mess,’ he says.

Some officials at the NIH feel that now the monkeys have proven scientifically
valuable, the NIH ought to take a tougher stand on letting the animals out
of their control. If so, the decision to try arbitration or not may become
a battle between those in the government who think keeping the issue alive
can only hurt the NIH and those NIH scientists who doubt whether arbitration
will allow them to do the experiments they want.

‘How can you force animal rights groups to honour their end of the bargain?’
Pons asks. ‘They’ve bargained in bad faith time after time.’

Last month, CDF put the value at 90.9 GeV plus or minus 0.35 GeV, ‘six
times more precise than any previous measurement’. CDF had produced 500
particles by the beginning of July.

More recently, the SLC has produced an even more accurate number for
the mass of the Z. Gary Feldman, who did the analysis, found that the mass
of the Z is 91.17 GeV plus or minus 0.18 GeV, a 20 per cent improvement
on the SLC’s own previous figure.

The team unveiled its new measurement of the mass of the Z at an international
conference on high-energy physics at Stanford University in Palo Alto, California.
At the same meeting, the scientists released preliminary results indicating
that only three generations of quarks exist in the Universe and, therefore,
that there are no more unsuspected quarks waiting to be discovered.

The scientists at Stanford have been racing with physicists at CERN,
the European Laboratory for Particle Physics, to find out how quickly Z
particles decay, which indicates how many kinds of quarks there are in existence.

Physicists have long wondered if there are more generations of quarks
waiting to be discovered. But since each generation was heavier than the
last, and heavier particles demand higher energies to create them, it would
be impossible to create and detect particles made up of such quarks in any
existing particle accelerator. Even one ‘known’ quark, the massive, so-called
‘top’ quark, remains undetected, but physicists expect to show its existence
soon, as accelerators move to higher energies.

Confirmation of the discovery will have to wait until researchers can
create more Z particles. The results from Stanford were based on a survey
of 250 Z particles, although the scientists there say they need to produce
thousands of Zs to be sure of the result. Stanford’s scientists are inching
towards that goal, producing 15 Z particles a day.

The existence of only three families of quark does not rule out the
existence of other particles entirely, however. If we can ever look for
non-quark particles at extremely high energies, says one physicist at the
conference, we may find how little we know about particles that make up
the Universe.