Biomedical subjects
Publications and source records attributed to A Qureshi.
An elderly gentleman with adenocarcinoma of the rectum who had abdominoperineal resection presented with scrotal skin and penile metastasis. Adenocarcinoma of the rectum metastasizing to the groin and penis is very rare and few cases have been reported.
A new 4-methylene sterol, 7alpha-hydroxytheonellasterol (3), was isolated from the Philippines sponge Theonella swinhoei, along with the known compounds theonellasterol (1) and bistheonellide A. The structure of 3 was elucidated by interpretation of its spectroscopic data, which were compared with those of 1.
Colonoscopy is an integral part of the clinician armamentarium in the diagnosis of colorectal cancer and its precursor, the adenoma. Polypoid lesions when identified can be excised at colonoscopy and in turn reduce the risk of colorectal cancer. We prospectively evaluated the yield of colorectal cancer and adenomatous polyps by indication for colonoscopy over a one-year period. A total of 375 colonoscopies were carried out. The more common indications of colonoscopy were rectal bleeding, abdominal pain, surveillance of colorectal cancer and altered bowel habit. The highest yield for cancer was for rectal bleeding with 12.5% while surveillance of patients with a history of polyps yielded the highest percentage of new polyps. We conclude that rectal bleeding as an indication for colonoscopy yielded the highest number of cancers.
Intrahepatic stones remain a major source of morbidity and mortality. With improving techniques in hepatobiliary surgery, the management and the outcome of intrahepatic calculi is reviewed. Forty-nine cases referred from all over Malaysia between January 1993 to June 1996 were analyzed retrospectively. There were thirty-two females and seventeen males. The median age was 46 years. Biliary diseases encountered in association with intrahepatic calculi included benign strictures (n = 14), ascariasis (n = 3), cholangiocarcinoma (n = 1), Caroli's disease (n = 1), and thalassaemia, (n = 1), fifty-six percent of stones were located in both the intrahepatic ducts while 34% were found in the left intrahepatic duct. Thirty-one patients underwent common bile duct exploration either alone or in combination with liver resection or bilioenteric anastomosis. Despite the various combinations of surgical and non-surgical intervention 28 (57.1%) patients had residual stones. Despite the availability of newer techniques in hepatobiliary surgery, residual stones were common, resulting in higher treatment costs.
The human immunodeficiency virus-1 (HIV-1) utilises CD4 and certain beta-chemokine receptors, mainly CCR-5 and CXCR4, for attachment and virus entry into T-lymphocytes and monocytes/macrophages. CD4 and beta-chemokine receptors participate in intracellular signalling via protein tyrosine kinases and G-protein-coupled signalling. The factors which influence HIV-1 replication and the intracellular signalling mechanisms elicited by the virus are not well understood. In this study, it was demonstrated that exposure of peripheral blood lymphocytes (PBLs) to a T-cell tropic strain of HIV-1 evokes signal(s) which results in downregulation of intracellular cAMP. In addition, pre-incubation of PBLs with the Gi-protein inhibitor Pertussis toxin mediated a significant inhibition of HIV-1 replication. These data strongly suggest that HIV-1 employs CD4 receptors and Gi-coupled proteins for entry into target cells and that productive HIV-1 infection is dependent on an active signalling event.
AIMS/HYPOTHESIS: Linkage between markers close to the uncoupling protein 2 and 3 genes (11q13) and resting metabolic rate and a pre-diabetic phenotype have been found. The syntenic region in mouse has been found to be linked to quantitative traits associated with obesity and diabetes. UCP2 and UCP3 could therefore have an important role in body weight regulation and susceptibility to diabetes. We investigated a recently identified variant of the UCP2 gene in exon 8 as a marker for glucose and weight homeostasis. METHODS: Length variation of the UCP2 exon 8 variant was studied by the polymerase chain reaction and agarose gel electrophoresis. Sequence variants of the UCP3 gene were sought by semi-automated DNA sequencing. RESULTS: In 453 South Indian subjects, we found an association in women between the UCP2 exon variant and body mass index (p = 0.018). These findings were replicated in a separate group of South Indian subjects (n = 143, p < 0.001) irrespective of sex. Although no association was found between the UCP2 exon 8 variant and overt obesity in British subjects, the UCP2 genotype of obese women (n = 83) correlated with fasting serum leptin concentration (p = 0.006) in the presence of extreme obesity. These observations could not be explained by tight linkage disequilibrium with a coding region variant in the region of the UCP3 gene of biological significance. Lastly, no association was found between UCP2 and Type II (non-insulin-dependent) diabetes using either a family based design (85 families) or case control study (normal glucose tolerance n = 335, impaired glucose tolerance n = 42, Type II diabetes n = 76). CONCLUSION/INTERPRETATION: We have described a UCP2 gene exon 8 variant that may affect susceptibility to weight gain by influencing regulation of leptin.
PURPOSE: Intravascular ultrasound (IVUS) was used to assess in vitro the morphologic and quantitative effects of balloon angioplasty (PTA) of the iliac artery. METHODS: Forty human iliac arteries (>/= 30% area stenosis) were studied with IVUS in vitro before and after PTA and the findings were validated with histology. RESULTS: The sensitivity of IVUS for dissection was 74% and for media rupture 59%. The incidence of vascular damage was higher when the whole segment was analyzed rather than the target site alone. Dissections occurred at the thinnest region of the plaque, unrelated to plaque calcification. Following PTA, quantitative changes at the target site were greater compared with the overall data derived from all cross-sections. The increase in lumen area was caused solely by an increase in vessel area. CONCLUSIONS: IVUS is sensitive in detecting dissections, which occurred irrespective of calcification at the thinnest region of the plaque. The increase in lumen area after PTA was caused by stretching of the vessel.
BACKGROUND & AIMS: Circulating levels of Ca2+ can influence secretory functions and myoelectrical properties of the stomach. A Ca2+-sensing receptor (CaR) has recently been identified in tissues that regulate systemic Ca2+ homeostasis. The aim of this study was to evaluate expression of CaR in the stomach of the rat. METHODS: In forestomach and glandular stomach, reverse-transcription polymerase chain reaction was used to amplify a 380-base pair product, which is 99% homologous with transcripts obtained in parathyroid and kidney. RESULTS: Northern analysis of gastric mucosal polyA+ RNA revealed 7. 5- and 4.1-kilobase transcripts, similar to those obtained in rat parathyroid and kidney. Immunohistochemistry revealed CaR expression in regions of the submucosal plexus and myenteric neurons. In sections of intact tissue, preparations of primary culture surface cells and surgically dissected gastric glands, staining was observed consistently in epithelial cells of the gastric glands and in gastric surface cells. In parietal cells in isolated gastric glands, intracellular levels of Ca2+ responded to conditions that are known to activate CaR. CONCLUSIONS: These are the first reported observations that CaR is expressed in different epithelial cells of mammalian gastric mucosa and its enteric nerve regions. The effects of extracellular Ca2+ on gastric function may be attributable to activation of CaR.
A specimen of Plakortis lita from Palau yielded the new carboxylic acids, homo-plakotenin (2a), the sodium salt of homo-plakotenin (2b), the sodium salt of nor-plakotenin (3), the sodium salt of plakotenin (1b), and the known compound plakotenin (1a). The structures of the new acids were elucidated by interpretation of spectral data and by comparison with the known compound. Compounds 1a, 1b, and 2a were found to significantly reduce proliferation of rheumatoid synovial fibroblasts.
1. Mibefradil was compared with (+/-)-verapamil for effects on ischaemia- and reperfusion-induced ventricular fibrillation (VF), and the role of ischaemia-selective L-channel block was examined. Langendorff perfused rat hearts (n=12/group) were used. 2. Neither drug at up to 100 nM reduced the incidence of VF during 30 min regional ischaemia. 300 and 600 nM (+/-)-verapamil abolished VF (P<0. 05); mibefradil was effective only at 600 nM (P<0.05). Reperfusion-induced VF incidence was reduced only by 600 nM (+/-)-verapamil (P<0.05). Both drugs at >/=100 nM increased coronary flow (P<0.05) with a similar potency and maximum effectiveness. 3. In separate hearts perfused with Krebs' solution containing 3 mM K+ (the same as that used for arrhythmia studies) neither drug at up to 600 nM affected ventricular contractility. With K+ raised to 6 mM, (+/-)-verapamil >/=30 nM reduced developed pressure (P<0.05); mibefradil did so only at 600 nM (P<0.05). With K+ raised to 10 mM the effects of (+/-)-verapamil were further increased (P<0.05) and mibefradil became active at >/=100 nM (P<0.05). Likewise both drugs impaired diastolic relaxation, with raised K+ exacerbating the effects and (+/-)-verapamil being more potent and its effects more greatly exacerbated by K+. In contrast, when K+ was normal (3 mM), coronary flow was increased by each drug at >/=30 nM (P<0.05) indicating a marked vascular : myocardial selectivity. 4. In conclusion, mibefradil differed from (+/-)-verapamil in its myocardial effects only in terms of its lower potency. As mibefradil is the more potent T-channel blocker, the T-channel is unlikely to represent the molecular target for these effects. The K+ elevations that occur in the ischaemic milieu determine the ability of both drugs to block myocardial L-channels; this is sufficient to account for the drugs' actions on VF. Neither drug possesses sufficient selectivity for ischaemic myocardium versus blood vessels to permit efficacy (VF suppression without marked vasodilatation) and so inappropriate hypotension is likely to preclude the safe use of mibefradil (or similar analogue) in VF suppression, and explains the lack of clinical effectiveness of (+/-)-verapamil.
We analyzed the characteristics of patients presenting with acute pancreatitis to our unit. A total of 71 patients were admitted to the Surgical Department at University Kebangsaan Malaysia (UKM) over a period of seven years, between January 1990 to December 1996 with acute pancreatitis. There was a fourfold increase in incidence of acute pancreatitis in our hospital from January 1990 to December 1996. The commonest identifiable aetiology was gallstones followed by alcohol. There were two deaths. We conclude that acute pancreatitis is increasingly being diagnosed in our local population. This may be due to either greater awareness or changes in lifestyle of the population.
Colorectal cancer is currently the third most common cancer in Malaysia. Elevated expression of COX-2, an induced cyclooxygenase isoenzyme, has been seen in colonic adenomas and colorectal carcinoma. There is evidence that inhibition of this COX-2 can decrease the risk of colorectal cancer. Selective COX-2 inhibitors may have a role in reducing the risk of colorectal cancer in high-risk individuals.
Non-steriodal anti-inflammatory drugs (NSAID) are not only associated with bleeding in the stomach and duodenum, but can also complicate pre-existing diverticular disease of the colon. Here, a 58 year-old male with severe per rectal bleeding is presented and the role of NSAID as a causative factor of his problem is discussed.
Rats drinking taurine and hypertonic saline (T + S) develop severe hypernatremia, but rats drinking either T or S alone do not. One hypothesis for this disruption of homeostasis is that the T + S combination interferes with the actions of antidiuretic hormone (ADH). Rats drinking T + S developed severe hypernatremia (170 mmol/L) by day 8 when infused with distilled water by osmotic minipumps, but maintained plasma sodium below 150 mmol/L when infused with ADH. Cumulative water balance in T + S drinkers receiving ADH was consistently higher than in those not receiving ADH. However the ratio of cumulative sodium balance to cumulative water balance suggests little uniform advantage to rats receiving ADH nor does comparison of urine osmolality in the two groups. Precisely how ADH administration reduces hypernatremia in T + S drinking rats remains unclear, but the hypothesis that T + S interferes with the action of ADH in its regulation of extracellular fluid volume and osmolality remains viable.
OBJECTIVES: This study was designed to assess the discrepancy in stent deployment seen on intravascular ultrasound and its relation to the balloon size selected for stent delivery. DESIGN: Prospective study. MATERIALS AND METHODS: The study group comprised 27 patients treated using a stent (n = 18) or stent-graft combination (n = 9). Following angiographically optimal stent deployment (< 10% residual stenosis) intravascular ultrasound was used to compare the smallest intra-stent lumen area with measurements at both stent edges and the lumen area of the proximal and distal reference sites. RESULTS: In 14 of the 27 stents the intra-stent dimension was the same as the dimension of the stent edge (difference < or = +/- 10%). Of the remaining stents the intra-stent dimension was smaller (difference > 10%) than the proximal stent edge in seven stents (range 11-39%), smaller than the distal stent edge in three stents (range 11-20%) and smaller than both stent edges in three stents (range 12-37%). Both in patients treated with a stent or stent-graft combination, the resulting smallest intra-stent lumen area was smaller than the balloon size used (mean difference 32% and 42%, respectively) and smaller than the mean lumen area of the reference sites (mean difference 25% and 23%, respectively). CONCLUSION: This intravascular ultrasound study shows a discrepancy between intra-stent lumen area, the area of the stent edges and the balloon size used.
Three new cyclic peroxides 5-7 and a new carboxylic acid ester 8 were isolated as minor metabolites from the hexane extract of a Plakinastrella species from the Philippines. The structures of compounds 5-8 were elucidated by interpretation of spectral data and by chemical interconversion, and the absolute stereochemistry of peroxide 6 was determined by application of Mosher's method to a derivative. Although the major compounds in the sponge showed activity against Candida albicans prior to decomposition, the minor metabolites 5-8 are essentially inactive.
Over 10 years one senior consultant surgeon performed 114 standard plication darn herniorraphies on 92 patients with primary inguinal hernias. These patients were contacted and were reviewed if there was any suspicion of recurrence. Four recurrences were detected, giving an overall recurrence rate of about 3.5%. According to actuarial life-table analysis the risks of recurrence at 1 year, 5 years and 10 years were 0.94%, 3.02% and 9%. This level of recurrence is unacceptable in modern practice and, as a result of the audit, the surgeon changed his technique of primary inguinal hernia repair.
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