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Biomedical subjects

G Tan

Publications and source records attributed to G Tan.

At least 19 recordsLinked to original sources
PubMed1995

Diagnostic difficulties caused by a nonclamped Schizophyllum commune isolate in a case of fungus ball of the lung.

The presence of clamp connections on hyphae and the development of fruiting bodies in culture are primary characters which allow identification of the basidiomycete Schizophyllum commune in cases of human infection. The diagnostic problems presented by a nonclamped, nonfruiting isolate from a dense mass in the right upper lobe of the lung in a female with a past history of pulmonary tuberculosis and diabetes are described. Several features of the isolated fungus, including rapid growth rate and white, dense, cottony colonies, tolerance to the fungicide benomyl at a concentration of 10 micrograms/ml, and susceptibility to cycloheximide at 400 micrograms/ml, suggested that it might be a basidiomycete. Transmission electron microscopy showed the presence of a dolipore septum with perforate pore cap characteristic of fungi in the class Holobasidiomycetes. However, species identification remained elusive until compatibility tests with known single-basidiospore isolates confirmed the identification of the sterile lung isolate as S. commune. Sequence analysis of the 5' internal transcribed spacer region of ribosomal DNA further supported conspecificity.

Base Sequence↗
PubMed1991

Comparison of monoclonal antibody and calcofluor white stains for the detection of Pneumocystis carinii from respiratory specimens.

Three monoclonal antibody staining kits, from Genetic Systems, Disease Detection International, and Meridian Diagnostics, were compared with calcofluor white for the direct detection of Pneumocystis carinii in respiratory specimens. Of the 150 specimens tested, 23 were found positive for P. carinii by any of the four stains; 13 were bronchoalveolar lavage, 7 were induced sputum and 3 were expectorated sputum specimens. All stains detected the positive bronchoalveolar lavage specimens, the Genetic Systems stain detected six induced sputum specimens, and the other stains each detected four induced sputum specimens. The monoclonal antibody stains detected all three expectorated specimens, while the calcofluor stain detected only one. Overall, the sensitivities of the stains were 96% for Genetic Systems, 87% for both Disease Detection International and Meridian Diagnostics, and 78% for calcofluor.

Antibodies, Fungal↗
PubMed1989

A case-control study of cervix cancer in Singapore.

Cervix cancer is about twice as common in Asia as in the Western world and its incidence varies among different Asian ethnic groups. A study based in Singapore, the population of which comprises Chinese, Indians and Malaysians, offers the opportunity to evaluate whether the same risk factors are important in this part of the world as in the West. A total of 135 cases and an equal number of controls were interviewed and details concerning reproductive and sexual history, smoking, hygiene, socio-economic status and education were collected. Seventy-three cases had invasive cancer while 62 had micro-invasive disease or CIN III. The most important risk factors were parity and number of sexual partners. Smoking was rare in cases and controls and did not appear to be an important determinant of risk. Of the socio-economic factors, education appeared most predictive and lowered the risk. Age at first intercourse was strongly correlated with education (positively) and parity (negatively), but not with number of sexual partners. Biopsies were available for HPV DNA analysis in 38 cases and 37% were positive, mostly for HPV type 16. All these factors gave similar risks in invasive and preinvasive disease.

Adult↗
PubMed1989

[Antibacterial sensitivity of Staphylococcus aureus isolated from clinical specimens].

In this study we evaluated the susceptibility of Staph. aureus to antibacterials in vitro by disk diffusion technique. 393 staph. aureus strains isolated from various clinical samples at the Bacteriology laboratory of Ankara University Medical Faculty Microbiology Department. As a result, the most effectual antibacterials are in order: Cefotaxime, Cefuroxime, Cephalothin, Ceftazidime, Sulbactam, Erythromycin, Kanamycin, Tetracycline, Clindamycin, Vancomycin, Thiamphenicol, Methicillin, Penicillin G.

Anti-Bacterial Agents↗
PubMed1989

[Isolation of beta-hemolytic streptococci from throat and nasal swabs and their antibiotic susceptibility].

1218 throat and 888 nasal swabs were collected from non hospitalized patients were examined for beta haemolytic streptococci. The samples were cultured on blood agar. To facilitate the isolation of beta haemolytic streptococci the samples were also cultured on biologically anaerobic sheep blood agar. From throat swabs and nasal swabs 174 and 13 beta haemolytic streptococci were isolated respectively. 113 beta haemolytic streptococci were identified as a group A (60%). In this study we evaluated the antibiotic susceptibility of streptococci. As a result the most effective antibiotics are in order Cefuroxime, Cefotaxime, Cephalothin, Thiamphenicol, Erythromycin.

Anti-Bacterial Agents↗
PubMed1989

Suicide trends in Australia, 1901-1985: an analysis of sex differentials.

This paper analyzes trends in the male-female suicide ratio in Australia, using data for the period 1901-1985. The main finding of the paper is that modernization, as measured by an index composed of the female participation rate in the labor force and the urbanization rate, is positively related to the male-female suicide ratio. This is contrary to an earlier finding by Stack and Danigelis (1985), who reported an inverse relationship between these two variables. This finding is shown to be due to the fact that no correction was made for trend. When the data series are corrected for trend, a significant positive relationship is found between modernization and the male-female suicide ratio in Australia. Another finding of the paper is that the female suicide rate in Australia has been falling significantly since the mid-1960s. This is also at variance with Stack and Danigelis's hypothesis that as modernization proceeds, the female suicide rate rises. We discuss reasons for this in the Australian context.

Adolescent↗
PubMed1980

Fibroblastic cultures from the diabetic db/db mouse. Demonstration of decreased insulin receptors and impaired responses to insulin.

Binding of 125I-insulin to cells cultured from the skin of nondiabetic and diabetic (db/db) mice was 80 to 90% specific, time- and temperature-dependent, and maximal at pH 8.0. Porcine insulin and desalanine insulin competed equally for 125I-insulin binding, while proinsulin and desoctapeptide insulin were 35% and 20% as potent, respectively. 125I-Insulin dissociated from both types of fibroblasts with a T 1/2 of 7.5 min. Analysis of the dissociation data resolved two rate constants of 3.0 and 1.0 X 10(-4) s-1 for nondiabetic, and 2.0 and 0.8 X 10(-4) s-1 for diabetic fibroblasts. Binding of 125I-insulin to diabetic fibroblasts was 35 to 50% of that to nondiabetic fibroblasts during at least 17 passages. Scatchard analysis of the binding data resolved high (K1 = 2 X 10(10( M-1) and low affinity K2 = 2 X 10(9) M-1) sites. Nondiabetic fibroblasts possessed 7.7 X 10(4) sites/cell, while diabetic fibroblasts possessed 2.9 X 10(4)/cell. Incubation of nondiabetic fibroblasts with insulin resulted in a time- and concentration-dependent decrease in the binding of 125I-insulin. Binding activity returned to normal when insulin was removed and it was prevented by cycloheximide. In contrast, diabetic fibroblasts did not exhibit down-regulation of receptors. A half-maximal and maximum (85%) stimulation of 2 deoxy-D-glucose uptake was observed with 0.75 nM and 16.7 nM insulin in nondiabetic fibroblasts. In contrast, diabetic cultures required 3.5 nM insulin for half-maximal stimulation of 2 deoxy-D-glucose uptake, and maximum stimulation was 32% with 16.7 nM insulin. Similarly, diabetic fibroblasts required higher concentrations of insulin (20 nM) to stimulate ornithine decarboxylase activity to 42% of nondiabetic cells. These results indicate that in comparison with fibroblastic cultures from nondiabetic animals, those from diabetic animals expressed differences in insulin receptor numbers which are maintained in culture over many generations and are accompanied by diminished insulin responses.

Animals↗
PubMed1980

Cells cultured from the diabetic (DB/DB) mouse have a permanent decrease in insulin receptors.

Investigation of mechanisms responsible for the decreased numbers of insulin receptors observed in obesity and diabetes has been facilitated by the development of cell culture systems permitting study of cellular events independent of fluctuating hormone levels and multiple endocrine interactions present in the whole organism. With such a system, we have found that cells cultured from the skin of diabetic mice have 45-48% fewer receptors for insulin than those from nondiabetic littermates. This difference is maintained in culture over many generations, suggesting that the decreased expression of insulin receptors in these cells is related to the genetic trait for diabetes.

Animals↗
PubMed1976

Treatment of gastroenteritis in children.

Mortality and morbidity in gastroenteritis in children is the result of fluid loss, acid-base and electrolyte imbalance. Hence therapy should be aimed at preventing or correcting this imbalance. The use of intestinal antibiotics to treat the condition should not be a routine, but parenteral antibiotic therapy in the presence of septicaemia is mandatory.

Anti-Bacterial Agents↗