An important breakthrough has been made in the research of
anti-SARS medicine in south China's Guangdong
Province. About 20,000 ml. of horse serum comprising an
idiosyncratic SARS neutralization antibody were successfully
extracted on July 20, according to relative departments in
Guangdong Province.
The curative effect of the horse serum is 100 times the serum
from convalescent SARS patients. Relative experts said the horse
serum will be gradually applied on animal and human experiments
after being purified and refined. If everything goes well, it will
be used in clinical treatment next February.
Medical departments in Guangdong advocated that people donated
their blood in order to save severe SARS patients, after serum from
convalescent SARS patients had been proved to contain
neutralization antibodies which could directly kill the SARS virus.
Medical workers in No. 8 People's Hospital of Guangzhou, the No.3
Hospital attached to Sun Yat-sen University
who had contracted SARS took the lead in donating blood, which had
successfully saved many patients in Beijing, Changchun and
Guangzhou. Although the serum from convalescent SARS patients had
special curative effect on the SARS virus, its resources were very
limited and blood recipients may have the risk of contracting other
diseases which are spread through blood, such as Hepatitis B,
Hepatitis C and AIDS.
Curative effect of horse serum is 100 times of human
serum
The Inactivated Vaccine Subject Team on SARS of Guangdong spent
three months on the research. They successively neutralized and
then killed the SARS virus from SARS patients five times since May
20 and then injected it into nine horses from Changchun and
Guangdong. The neutralization antibody of the SARS virus had been
developed in these horses. Its titer reached 5,120, 100 times the
titer of the serum from convalescent SARS patients, that is to say,
the curative effect of the extracted 20,000 ml. horse serum was
equal to 2 million ml human serum. If 100 ml. human serum can save
one SARS patient, then the currently developed horse serum can save
20,000 SARS patients.
Three steps for the application of horse
serum??
Led by Sun Yat-sen University, the Inactivate Vaccine Subject
Team was composed of the Military Necessity University of PLA
(People's Liberation Army), NO.1 Military Hospital of PLA, the
Biological Medicine Research Base of Jinan
University and Guangdong Provincial Center for Disease Control
and Prevention.
The subject team will first purify and refine this batch of
horse serum. Direct injection of the horse serum into the human
body will cause an allergy and repellent effect. If splitting the
SARS antibody in the horse serum with papain and pepsin and cutting
the "allergic part" and saving the "effective part", patients will
not be allergic to it. The whole procedure will need 10 days.
The second step, to conduct analysis and appraisal on the
curative effect of the horse serum, which can be confirmed through
two channels: one to inject the horse serum into animals, such as
monkeys, and then infect the animal with the SARS virus; second, to
treat SARS infected animals with the horse serum. The results on
the neutralization reaction of the cells level carried out in the
lab had approved that under the microscope, the number of cells in
the cultivation solution of kidney cells from the African green
monkey which was attacked by the SARS virus, was reducing,
deforming, destroyed, dissolving and even totally dead. If adding
the horse serum first and then attacking it with SARS virus later,
the shape of kidney cells are the same as normal cells. Doctor Lu
Jiahai disclosed that this step could be achieved within a month if
qualified animal models were available.
Finally, the horse serum will be applied on a human test. After
appraisal of its curative effect and safety, it will be widely used
as emergent injections on medical workers who may have contracted
SARS or suspicious cases as well as treatment on confirmed SARS
patients.
Opposite voice
Wang Jingxing, expert from the Anti-SARS Task Team of the Ministry of Science
and Technology and vice director of China's Blood Transfusion
Association, said the horse serum was extracted from the horse
whose protein structure was different from the human body. It is
very likely to cause repellent and allergic reaction if it is used
in the treatment of humans, and it may endanger people's life. For
clinical diseases, the horse serum is only adopted in
emergency.
Wang said that his subject team has made research on this before
and the effect was not so satisfactory. He also showed his doubts
on the saying that "the curative effect of horse serum is 100 times
of human serum". According to Wang, the calculation method and
result made in lab are not totally identical to the clinical
practice. Therefore, it is too early to make such a conclusion.
(China.org.cn by Wang Qian July 28, 2003)
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