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Biomedical subjects

J Shao

Publications and source records attributed to J Shao.

At least 19 recordsLinked to original sources
PubMed1992

Retinoic acid inhibition of serum-induced c-fos transcription in a fibrosarcoma cell line.

We investigated the mechanism by which retinoic acid causes growth arrest and flat reversion of SSV-NRK, simian sarcoma virus-transformed normal rat kidney cells. Northern analysis revealed that both chronic (7 days) and acute (6 h) retinoic acid treatment of serum-stimulated SSV-NRK cells caused a 6-fold decrease in c-fos mRNA levels. In addition, nuclear run-on experiments showed that retinoic acid regulated c-fos expression in SSV-NRK cells at the transcriptional initiation level. Attenuation of c-fos transcription was equal in both retinoic acid-treated and control cells, and no increased c-fos mRNA turnover was detected in retinoic acid-treated cells. Furthermore, there was no observed change in the c-fos mRNA levels after only 30 min of retinoic acid treatment, suggesting that a mechanism involving the interruption of the signal transduction mechanism at the membrane level is unlikely. Because it has been shown that c-fos expression plays a pivotal role in mitogenesis of quiescent fibroblasts, we conclude that the retinoic acid-mediated down-regulation of c-fos expression is a mechanism for growth inhibition in SSV-NRK cells.

Animals↗
PubMed1992

The AIDS epidemic in Tanzania: rate of spread of HIV in blood donors and pregnant women in Dar es Salaam.

The prevalence of antibodies to HIV in population groups in Dar es Salaam, Tanzania has been monitored from late 1984 through 1991. In the pregnant women and blood donors the doubling time was about 2 years. If, however, the doubling time is calculated from reported cases of AIDS of the whole country, an average doubling time of 10 months is obtained. We point out factors that may bias calculations of the rate of spread of the virus and thus give rise to erroneous projections for the nearest years, especially the so-called transient effect. It is recommended that serosurveys of representative population groups are carried out at regular intervals.

Acquired Immunodeficiency Syndrome↗
PubMed1992

[Preparation of sucking tablet of shengmei] off.

The Sucking Tablet of Shengmei is made from eight Chinese traditional drugs including Radix Adenophorae, Fructus Mume, etc. The effective rate of the tablet in treating chronic pharyngitis reaches up to 96 percent. The working mechanism related to the fact that the tablet is bacteria-resistant and helps to strengthen the body function. This paper presents the preparation process of the Sucking Tablet along with solutions for some problems encountered in the process and appropriate standards for quality control.

Animals↗
PubMed1992

[Studies on the dissolution and bioavailability of trimethoprim-sulfadiazine-sulfamethoxazole tablets].

A reverse-phase high performance liquid chromatographic method was established for the simultaneous determination of trimethoprim (TMP), sulfadiazine (SD) and sulfamethoxazole (SMZ) in dissolution media. Meanwhile, another reverse-phase high performance liquid chromatographic method was developed for the simultaneous determination of the three drugs mentioned above and their metabolites, N4-acetyl-SD and N4-acetyl-SMZ in serum. The in vitro dissolution and in vivo bioavailability of two commercial trimethoprim-sulfadiazine-sulfamethoxazole tablets (A and B) were studied. Drugs were released far more rapidly from A than from B. Significant difference (P less than 0.001) was observed between the T50 s of the same active principles released from A and B. The in vivo processes of all three active principles in 8 healthy subjects taking two tablets each could be described by one-compartment model with first-order absorption and elimination. Compared with A, the relative bioavailabilities of B were 0.83, 0.73 and 0.78 for TMP, SD and SMZ, respectively. Drugs were absorbed more rapidly from A than from B.

Adult↗
PubMed1991

Seroepidemiological correlations of antibodies to human herpesviruses and human immunodeficiency virus type 1 in African patients.

A seroepidemiological evaluation of the humoral immune response against human herpes viruses was carried out in patients with and without HIV infection in Tanzania to study the role of these viruses as a cofactor in AIDS. Serum specimens were obtained from 321 outpatients and 100 healthy schoolchildren of a rural population in the Kagera Region, Tanzania, and from 149 inpatients of an urban population in Dar-es-Salaam, Tanzania. The data were analysed by logistic models taking into account demographic variables. The data obtained revealed no differences in the prevalence of antibodies to human herpes viruses between the different groups. Therefore, our study under the present conditions and the observed stages of AIDS does not suggest an influence of HIV infection on human herpesvirus infection or serologic response.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Assessment of bioequivalence using a multiplicative model.

In many bioavailability/bioequivalence studies, the distributions of responses such as AUC and Cmax are often positively skewed and exhibit a lack of homogeneity of variances. In this situation, a logarithmic transformation is usually considered for reduction of skewness and achievement of an additive model with relatively homogeneous variance. In this paper, consideration is given to a multiplicative model based on empirical evidence. A method is proposed using individual subject ratios for assessing the bioequivalence of two different formulations. This method is then subsequently extended to several commonly used crossover experiments.

Biological Availability↗
PubMed1991

Estimating drug shelf-life with random batches.

The problem of assessing the shelf-lives of drug products in the market is considered. We focus on the situation where the drug characteristic of interest has a linear relationship over time and batch-to-batch variation is present. Two methods for assessing shelf-lives are proposed based on the weighted least squares method under a regression model with random coefficients. An application to some stability data from the pharmaceutical industry is presented.

Drug Stability↗
PubMed1991

Oral yeast flora of a population in an area of Tanzania bordering an AIDS endemic zone.

Mouth swabs from 1,288 individuals in the North Mara region of Tanzania were cultured for yeasts. Subjects were randomly selected from rural and urban areas, and a group of food handlers were also studied. Yeasts were cultured from 407 (31.6%) and Candida albicans from 141 (10.9%) subjects. A wide variety of other yeast species were also identified.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Induction of antitumor activity and experimental expansion of human lung cancer-infiltrating lymphocytes.

In order to look for effector cells which are more efficient and less toxic than LAK cells induced from PBL for use in adoptive immunotherapy, we studied the antitumor activity and in vitro expansion of tumor infiltrating lymphocytes (TIL) from human lung cancers and compared their cytological properties with those of autologous PBL. The results showed: 1) Large numbers of TIL could be obtained from lung cancer tissue, approximately 1-5 x 10(8)/g tumor tissue, with an average TIL to tumor cell ratio of 2.3:1 (21 samples). 2) Fresh TIL were not cytotoxic against either NK-sensitive or -resistant tumor targets. After culturing for 6 to 8 d in the presence of rIL-2, TIL showed significant cytotoxicity and were able to kill autologous and allogeneic tumor targets and fresh solid tumor targets. 3) When maintained in the presence of rIL-2, TIL were able to continue proliferating and expanding for more than 2 mon, with expansion indices of 4-512. TIL stopped proliferating following the disappearance of autologous tumor cells in the culture. 4) Chronological studies revealed that the cytotoxicity appeared after 4 days in culture and reached a peak on the 14th day, and cultured TIL remained cytotoxic for at least 4 wk.

Adenocarcinoma↗
PubMed1991

[An approach to the preparation of digestive enzyme-drug for oral administration: complex lactase microcapsules].

Complex microcapsules which could protect enzyme drugs from inactivation in both the stomach and intestine were prepared. In the process, semipermeable microcapsules were first formed by enveloping the enzymes within spherical, ultrathin semipermeable membranes. To resist gastric juice, the semipermeable microcapsules were further encapsulated by enteric-soluble materials to form complex microcapsules. When the preparations were taken into the intestine, the semipermeable microcapsules were released and small molecular substrates could then equilibrate rapidly across the semipermeable membrane to be acted on by the enveloped enzymes, while alimentary proteases remained outside. This complex microcapsulated lactase could retain over 65% of its activity after simulation in gastric juice for 2 h, and over 60% of its activity was retained after 6 h in pancreatin-containing simulated intestinal juice. On the contrary, unencapsulated lactase lost all activities immediately under the same conditions.

Capsules↗
PubMed1991

A cross-sectional study of a program for HIV infection control among public house workers.

We report results of a cross-sectional study of a program for human immunodeficiency virus (HIV) infection control among public house workers in Dar es Salaam. Forty percent of the 605 workers sampled had been part of this program, which included behavioral counseling and provision of condoms, for 1 year. The remaining 60% were new recruits. Program participation was associated with both enhanced condom use (p less than 0.001) and behavioral modification (p less than 0.001). Females, and specifically barmaids, were more likely to be condom users but were less likely to have changed their behavior in other respects. Seropositivity to both HIV and Treponema pallidum tended to be higher among females, especially the barmaids. Since barmaids and waitresses in public houses in Dar es Salaam often engage in prostitution, it is felt that to effect a reduction of numbers of their sexual partners, there is a need to address the social and economic factors underlying high-risk sexual behavior.

Adult↗
PubMed1990

Acid-labile anchoring linkages for solid phase synthesis of C-terminal asparagine peptides using the Fmoc strategy.

Two acid-labile substituted benzylamine type anchoring linkages, 4-benzoxy-2,6-dimethoxybenzylamine and 2-benzoxy-4,6-dimethoxybenzylamine, for solid phase synthesis of peptide amides were prepared. The Na-9-fluorenylmethyloxycarbonyl (Fmoc) amino acids could be easily attached to the resins with DCC/HOBt (loading 0.5-0.6 mmol/g resin). After final removal of the Na-protecting groups, treatment with TFA (50-95%) yielded amino acid and peptide amides in high purity. As we could show for the synthesis of thymulin (FTS, pGlu-Ala-Lys-Ser-Gln-Gly-Gly-Ser-Asn), these two resins with anchoring linkages are well suited for the synthesis of C-terminal Asn peptides using protected aspartic acid derivative as starting material.

Amino Acid Sequence↗
PubMed1990

Evaluation of simple tests for detection of HIV antibodies: analysis of interobserver variation in Tanzania.

200 sera were tested for HIV antibodies with different tests in Tanzania. The results were interpreted by 5 different observers with different laboratory experience. There was considerable variation between observers and between testing methods. HIV-Chek was easiest to perform with little interobserver variation, but a few probably false negative readings were seen. Serodia gave many false positives. Western Blots gave more diverging results due to indeterminate sera and lack of training. HIV-Chek seems best when time, facilities, and training are limited and if combined with Serodia false negative results can be excluded.

Blotting, Western↗
PubMed1989

Test for batch-to-batch variation in stability analysis.

We propose several statistical tests for batch-to-batch variation in the stability analysis of a drug product and present applications with data from new drug application stability and marketing stability analyses.

Drug Industry↗