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Biomedical subjects

G Tan

Publications and source records attributed to G Tan.

At least 55 records · Page 3Linked to original sources
PubMed1996

[Endoscopic sinus surgery, clinical aspect with 69 cases].

Sixty-nine patients (121 sides) received endoscopic sinus surgery between May, 1993 and October, 1994. All of the patients exhibited following clinical signs: bilateral or unilateral nasal polyps and paranasal sinusitis. There were 43 men and 26 women, ranging in age from 14 to 68 years. Among the patients, 14 (25 sides) were treated with functional ethmoidectomy; 33 (59 sides) with total ethmoidectomy; and 21 (36 sides) with sphenoethmoidectomy. 23 patients (36 sides) were treated simultaneously with radical maxillary sinus surgery. According to the data of postoperative follow-up, nasal obstruction disappeared completely in 57 cases (57/59); headache remitted in 51 (51/56); and 35 (35/54) were free of purulent nasal discharge. No severe complications were observed. The incidence of residual and recurrent polyp were 12.39% (15/121 sides). The curative effect of endoscopic sinus surgery was analysed. The indications of operation, the preoperative CT scan of paranasal sinuses, and the endoscopic techniques were discussed.

Adolescent↗
PubMed1996

[Nasal polyps of olfactory sulcus].

To explore the origin of olfactory sulcus polyp (OSP) and observe the recovery of olfaction after functional endoscopic sinus surgery, fifty-nine olfactory sulcus polyps in 31 patients were reviewed. The origin of OSP was carefully observed. In these patients 69.5% (41 sides) originated from the mucosa of posterior ethmoid sinus, including the superior meatus (23 sides) and ethmoid cells near the ostia (18 sides). OSP originated from middle turbinate (8 sides) and superior turbinate (4 sides). Six OSP originated from the mucosa of both ethmoid and sphenoid sinus. Olfactory changes were dynamically observed after endoscopic sinus surgery in 26 patients. The smell improved significantly in 26 sides (52.0%) within three months. The olfaction improved slowly in those patients with recurrent polyps and polysinusitis associated with polyps. We suggest that minimal endoscopic sinus surgery is the treatment of choice for OSP.

Adolescent↗
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↗
PubMed1994

Evaluation of patients' knowledge about anticoagulant treatment.

OBJECTIVE: To develop a questionnaire to evaluate patients' knowledge of anticoagulation. DESIGN: Anonymous self completed questionnaire study based on hospital anticoagulant guidelines. SETTING: Anticoagulant clinic in a 580 bed district general hospital in London. SUBJECTS: 70 consecutive patients newly referred to the anticoagulant clinic over six months. MAIN MEASURES: Information received by patients on six items of anticoagulation counselling (mode of action of warfarin, adverse effects of over or under anticoagulation, drugs to avoid, action if bleeding or bruising occurs, and alcohol consumption), the source of such information, and patients' knowledge about anticoagulation. RESULTS: Of the recruits, 36 (51%) were male; 38(54%) were aged below 46 years, 22(31%) 46-60, and 10(14%) over 75. 50 (71%) questionnaires were returned. In all, 40 respondents spoke English at home and six another language. Most patients reported being clearly advised on five of the six items, but knowledge about anticoagulation was poor. Few patients could correctly identify adverse conditions associated with poor control of anticoagulation: bleeding was identified by only 30(60%), bruising by 23(56%), and thrombosis by 18(36%). Only 26(52%) patients could identify an excessive level of alcohol consumption, and only seven (14%) could identify three or more self prescribed agents which may interfere with warfarin. CONCLUSION: The questionnaire provided a simple method of determining patients' knowledge of anticoagulation, and its results indicated that this requires improvement. IMPLICATIONS: Patients' responses suggested that advice was not always given by medical staff, and use of counselling checklists is recommended. Reinforcement of advice by non-medical counsellors and with educational guides such as posters or leaflets should be considered. Such initiatives are currently being evaluated in a repeat survey.

Aged↗
PubMed1993

Disseminated atypical blastomycosis in two patients with AIDS.

Two men with AIDS developed fungal infections and subsequently died as a result of dissemination of the fungal infection. Findings obtained by histologic examination, serological studies, and cultures suggested that the infections were caused by Blastomyces dermatitidis. Tissue sections showed polymorphic yeast-like cells 5-20 microns in diameter (some with broad and others with narrow single- or multiple-based buds), small yeasts, and hyphal elements. The exoantigen K positivity and exoantigen A negativity of one of the isolates indicated that the fungus was more like an African than a North American serotype.

AIDS-Related Opportunistic Infections↗
PubMed1993

Audit of start of anticoagulation treatment in inpatients.

AIMS: To develop a method for evaluating the start of anticoagulation treatment in inpatients. METHODS: One hundred case notes were audited using a proforma based on local guidelines in accordance with British Society for Haematology recommendations. RESULTS: Confirmatory investigations were done in 93% and 79% of patients with symptomatic deep venous thrombosis and pulmonary embolism, respectively. Identification of patients' risk factors for anticoagulation by history taking and laboratory tests was often inadequate: baseline coagulation screen, platelet count, liver function and renal function tests were done in 52%, 95%, 70% and 87% of cases, respectively. There was a tendency to undertreat patients: 33% of the activated partial thromboplastin times (APTT) and 58% of the International Normalised Ratios (INR) were subtherapeutic. The heparin-warfarin crossover period was particularly problematic: 37% stopped heparin without an INR that day, or had an INR of less than 2. Microscopic haematuria was monitored occasionally. Of the 62 patients continuing anticoagulation, 72% were discharged with the final INR in the therapeutic range. At discharge, only 74% of patients had documented appointments for the anticoagulant Clinic, the period between discharge and appointment ranging from 0 to 12 days. Of the 25 cases with an appointment exceeding four days after discharge, only six (24%) had arrangements for an interim INR check. CONCLUSIONS: The experience allowed the proforma to become streamlined to a more practical, reliable, and valid tool for use elsewhere. Findings will be fed back to the hospital staff to promote practice improvements before closing the audit loop by re-evaluating practice. Further studies are in progress to identify barriers experienced by doctors in implementing the guidelines and problems in the process of referral to the anticoagulant clinic.

Adult↗
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↗