Biomedical subjects
Publications and source records attributed to H L Choong.
A case of primary tuberculous chancre of the vulva is reported. Although a tuberculous infection in an immunocompromised patient is not uncommon, this is the first report of a primary tuberculous infection on the external genitalia in such a patient. The source of infection in this patient could not be determined.
Arginine vasopressin (AVP) and oxytocin (OXT) induced contraction in cultured vascular smooth muscle cells (VSMC) and glomerular mesangial cells (GMC). The contractile response of AVP and OXT was paralleled by Ca2+ mobilization as assessed by 45Ca2+ efflux in a dose-dependent manner. The effects of AVP were blocked by pretreating VSMC and GMC with a V1 antagonist. OXT-stimulated effects, however, were not affected by preexposure of VSMC and GMC to an OXT antagonist but were inhibited by the V1 antagonist. Competition studies demonstrated displacement of [3H]AVP from its receptors by unlabeled AVP, the V1 antagonist, and high doses of OXT. The OXT antagonist was the least effective in displacing [3H]AVP. Thus occupancy of the V1 receptor by OXT may initiate signal transduction and contraction in VSMC and GMC in a manner qualitatively similar to that of the AVP agonist. Cultured myometrium cells (MMC) also contracted in response to AVP and OXT. Moreover, 45Ca2+ efflux increased in response to both hormones in a dose-dependent manner. AVP-stimulated contraction and 45Ca2+ efflux were blocked in MMC by pretreatment with V1 antagonist. OXT-induced effects were inhibited by the OXT antagonist but not by the V1 antagonist. Binding experiments showed that [3H]AVP was displaced equally by unlabeled AVP and V1 antagonist. Very high concentrations of OXT antagonist also demonstrated displacement.(ABSTRACT TRUNCATED AT 250 WORDS)
The chronic haemodialysis programme of the Singapore General Hospital started in 1968 as a hospital-based fully nurse-assisted programme. This has since expanded to include Self Dialysis and Home Dialysis programmes. Data of 425 patients who entered the dialysis programmes was analysed retrospectively. The major cause of end stage renal failure was chronic glomerulonephritis (52%). Almost half of the patients in the haemodialysis programme were patients on self-dialysis (49%). There were 157 withdrawals and 116 deaths. Survival has improved tremendously with the use of treated water for dialysis from 1981. The 5 year survival in an earlier group of patients dialysed with untreated water was 48% compared with 81% in a late group dialysed with treated water (p less than 0.001). The pattern of complications has also changed with a lower incidence of dialysis osteomalacia, hypertension, hepatitis and eradication of dialysis dementia.
This study aimed to determine the prevalence of endoscopic and histological gastroduodenitis as well as helicobacter-like organisms in patients with end stage renal failure undergoing maintenance dialysis treatment. A total of 322 out of 422 patients in our dialysis programme underwent endoscopy and gastroduodenal biopsy specimens were taken from 260. Endoscopic gastroduodenitis occurred in 158 (49%). Histological gastritis occurred in the gastric body or antrum in 134 patients (52%) and duodenitis in 52 (21%). There was no correlation between endoscopic and histological gastritis in contrast to a significant correlation for duodenitis. Helicobacter-like organisms occurred in the body or antrum in 81 (31%). Their presence was associated with gastritis--in particular acute and acute on chronic gastritis rather than chronic gastritis. Patients with gastritis were significantly older than those without (p less than 0.001) and had lower basal and peak acid outputs.
We endoscoped 322 of 422 patients with end-stage renal failure undergoing maintenance dialysis treatment to determine the prevalence of erosive prepyloric changes (EPC) in uraemia. EPC grade 1 was found in 79 patients (25%), grade 2 in 16 (5%), and grade 3 in 43 (13%). EPC grades 2 and 3 were commoner among uraemic patients than among non-uraemic patients presenting for gastroduodenoscopy (13 of 198 = 6%; p less than 0.001). Patients with EPC grades 2 and 3 were older, had been receiving dialysis longer, and were more likely to be receiving haemodialysis rather than peritoneal dialysis when compared with patients without EPC. Histologic gastritis of the body and antrum was less common among patients with EPC grades 2 and 3 than among patients without EPC. The prevalence of Campylobacter-like organisms was similar in patients with and without EPC.
Thirty-two patients with end stage renal failure who were on haemodialysis and who had no previous exposure to hepatitis B virus were given four intramuscular injections of 40 micrograms (twice the recommended dose) recombinant DNA hepatitis B vaccine (Engerix B, Smith Kline Biologicals) at 0, 1, 2 and 6 months to determine the immunogenicity of this increased vaccine dose. The ages of these patients ranged from 23-54 years with a mean age of 40 years. There were 11 males and 21 females. Three patients underwent renal transplantation during the course of the study and were assessed separately. Antibody levels above 10 IU/L were noticed in 83% of the remaining 29 patients two months after the final dose with an anti-HBs geometric mean titre (GMT) of 2551 IU/L. The antibody response was 82% four months later although the GMT has fallen to 664 IU/L. Renal transplantation did not appear to affect the anti-HBs response to the above vaccination regime. None of the volunteers developed hepatitis B during the study. Our results were much better than results obtained in studies using twice the recommended doses given three times.