[The study of renal safety in elderly patients with benign prostatic hyperplasia treated with α receptor blockers].

Objective: To investigate the renal safety in patients with benign prostatic hyperplasia treated with tamsulosin hydrochloride. Methods: A retrospective analysis of 10 cases of patients, who had renal dysfunction after treatment with long-term tamsulosin hydrochloride. Results: The average duration of oral medicine was 2 to 24 months with an average of 7.2 months. The serum creatinine after discontinuation of tamsulosin hydrochloride decreased from 132.5 µmol/L (100-208 µmol/L, normal 59-104 µmol/L) to 95.7 µmol/L (73-122 µmol/L, normal: 59-104 µmol/L) (F=10.385, P=0.000). Conclusion: Preliminary results show that taking tamsulosin hydrochloride might lead to renal damage in old patients with benign prostatic hyperplasia. Safety is the premise, and the right medicine should be chosen for different side effects in order to protect the safety of patient.

Ecology and prevention of a shellfish-associated hepatitis A epidemic in Shanghai, China.

During a shellfish-borne hepatitis A outbreak in Shanghai during the first quarter of 1988, 300,000 cases were reported in two months. Using cell culture and experimental infection of marmosets, hepatitis A virus (HAV) was isolated from clams collected from the market and the sea bed during the epidemic. A dose-response curve correlating the quantity of clams consumed to the attack rate of hepatitis A was well documented. The occurrence of the epidemic was associated with a good harvest of clams in a new area, serious pollution of this area with sewage and importation of the clams in large quantities into Shanghai where most young adults were susceptible. Clams can apparently be decontaminated by using a continuous water flow. In this way, HAV titres can be reduced by 90% in one day and by 99.9% in two weeks. An attenuated live HAV vaccine which has been developed in China has been shown to be safe and immunogenic and may be used for prevention of such epidemics in the future.

Primary study of attenuated live hepatitis A vaccine (H2 strain) in humans.

Strain H2, an attenuated live hepatitis A virus (HAV), was derived from the fecal specimen of a patient with hepatitis A in Hangzhou, China. After isolation and passage in a culture of newborn monkey kidney cells, adaptation to grow in human lung diploid cells (KMB17), and serial passage at a low temperature (32 degrees C) in KMB17 cells, this strain became the master seed virus for H2-strain vaccine. Twelve human volunteers received the experimental vaccine subcutaneously and were closely observed for 20 w. None of the subjects developed any local or systemic reactions, and there were no elevations of serum glutamic-pyruvic transaminase, type 5 isoenzyme of lactate dehydrogenase, or isocitrate dehydrogenase. Seroconversion occurred in all subjects at a mean time of 3 w after inoculation. ELISA competitive test for titer of antibody to HAV showed values ranging from 1:2 to 1:8 with a geometric mean titer of 1:3.48 at 20 w after inoculation. No marked decrease in titer of HAV antibody was found in the subjects tested at 1 y. These antibodies were proved to be neutralizing antibodies.

[The trial preparation of attenuated live hepatitis A vaccine].

The experimental attenuated live hepatitis A vaccine has been prepared in KMB17 human fetal lung diploid cells with the HAV variant H2M20K5 (32 degrees C). No extraneous agent was detected in the vaccine, which had a titer of 10(6.5) TCID50/ml. Twelve monkeys vaccinated intravenously or subcutaneously were found to have no significant clinical hepatitis but with anti-HAV antibody in all cases. Thus the safety and immunogenicity of the vaccine were evidenced in monkeys and it is necessary to investigate the trial vaccination further in a few susceptible individuals.

Studies in monkeys of attenuated hepatitis A variants.

Three HAV variants, H2M20(35 degrees C), H2M20(35 degrees C) and H2M20K5(32 degrees C), were developed by passage in different tissue culture cells and at different temperatures. Virulence for monkeys was assessed by inoculating each of the variants into four monkeys. Weekly bleeding through 16 weeks post-inoculation was assayed for anti-HAV titers and SGPT as well as LDH5 activities. And in some monkeys liver biopsies were also studied. Seroconversion was induced in all of the inoculated monkeys. The anti-HAV titers tested at 16 weeks post-inoculation were: 40-640 with H2M20(35 degrees C), 40-160 with H2M20(32 degrees C) and 20-40 with H2M20K5(32 degrees C). These variants showed different levels of virulence/attenuation for monkeys. Variant H2M20(35 degrees C) showed no evidence of attenuation, variant H2M20(32 degrees C) retained slight virulence and variant H2M20K5(32 degrees C) showed no evidence of virulence for monkeys. Criteria are proposed for assay of HAV virulence tested in monkeys.

Immunization of neonates with trivalent oral poliomyelitis vaccine (Sabin).

A study was carried out between November 1981 and April 1982 on the immunological effect of administering trivalent live, oral polio vaccine to 200 mature healthy neonates from Henan Province, China. The initial dose of vaccine was given at 3 days of age, and 2 months thereafter antibodies to poliovirus types 1, 2, and 3, respectively, were detected in 46.7%, 60.7% and 48.6% of the neonates; after the second dose, the levels were 86.9%, 95.3%, and 97.2%, with geometric mean titres of 1:106.2, 1:349.8, and 1:232.5. Almost 100% of neonates exhibited antibodies after the fourth dose of vaccine. Eighty-two percent of the neonates excreted poliovirus for at least a week after the initial dose of vaccine, and this increased to 99% after the second dose. Seroconversion at 4 months of age was similar to that of a group of controls who received their initial dose of vaccine at 2 months of age; however, immunization of neonates induced immunity to poliovirus at the earliest possible age.

Immunization with oral poliovirus vaccine in China.

China began to produce oral, live poliovirus vaccine ( OPV ) in 1960. During 1960-1964, OPV was introduced in major cities only and subsequently was used throughout the country. Since that time the incidence of poliomyelitis has dropped dramatically, and the percentage of the healthy population with antibody has clearly risen. Data from many observations showed a high rate of isolation of other enteroviruses in the healthy population and in individuals with poliomyelitis. These findings indicate that some paralytic cases may be caused by other enteroviruses. Localized outbreaks of poliomyelitis still occur, however, and their elimination will require a campaign to ensure that greater than 90% of susceptible individuals are immunized.

PIP: Available only in major cities in China during 1960-64, oral, poliovirus vaccine (OPV) now is used throughout the country. Prior to the vaccination program in 1960-64, the average annual incidence of poliomyelitis was 3.18 cases/100,000 population. The incidence dropped to 0.80/100,000 population in 1976-80 and to 0.47/100,000 population in 1981. The incidence of poliomyelitis was reduced markedly in those areas where an expanded immunization program was well administered. The data from a large investigation of poliovirus neutralizing antibody in health populations in Shanghai, Hunan, Henan, and other cities and provinces showed clear elevation of antibody levels as well as good immunologic effectiveness for OPV. The high rate of isolation of other enteroviruses in the health population (16.1% compared with 3.2% for poliovirus) and in persons with poliomyelitis (rate of isolation of poliovirus, 29.5%; other enteroviruses, 13.9%) indicates that some paralytic cases may be caused by other enteroviruses. The eradication of poliomyelitis has not yet been realized in China. Outbreaks in local areas, reported on occasion, influence the national incidence rates. Investigations conducted in several such areas showed that 93% of the affected individuals had not been vaccinated previously. An expanded immunization program is needed.