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Biomedical subjects

Y T Lim

Publications and source records attributed to Y T Lim.

50 records · Page 3Linked to original sources
PubMed1994

Diagnosis of pelvic endometriosis: fat-suppressed T1-weighted vs conventional MR images.

OBJECTIVE: The purpose of this study was to compare fat-suppressed T1-weighted with conventional MR images for the diagnosis of endometriosis, focusing on the detectability of peritoneal implants, and to evaluate the usefulness of MR imaging in predicting the severity of disease. SUBJECTS AND METHODS: We analyzed the MR images of 31 patients with clinically suspected endometriosis. Laparoscopy confirmed no evidence of disease in two and endometriosis in 29. Conventional T1- and T2-weighted images and supplementary axial fat-suppressed images were obtained in all patients. In both groups, detection of endometriotic lesions with MR imaging was compared with detection at laparoscopy. Only the findings on fat-suppressed images were used to evaluate the usefulness of MR imaging in predicting the severity of disease. Early stages of disease included stages I and II; advanced stages of disease included stages III and IV. RESULTS: Diagnostic accuracy was higher with fat-suppressed imaging (77%) than with conventional imaging (55%) (p = .06). The overall sensitivity in detecting peritoneal implants was significantly higher with fat-suppressed imaging (61%) than with conventional imaging (27%) (p < .01). The disease was likely to be at an early stage when MR images showed peritoneal implants that were 5 mm or less in maximum diameter. The disease was likely to be at an advanced stage when MR images showed an endometrial cyst that was larger than 1.5 cm. CONCLUSION: Our results show that fat-suppressed MR imaging is more accurate in the diagnosis of pelvic endometriosis and is better for predicting the severity of disease than conventional MR imaging is.

Adult↗
PubMed1994

Severe aortic regurgitation due to Neisseria mucosa endocarditis.

A rare occurrence of Neisseria mucosa endocarditis on a native aortic valve not known to be diseased is reported. Despite vigorous antibiotic therapy, severe aortic regurgitation developed necessitating aortic valve replacement. At operation, the right coronary cusp was retracted with two small nodules attached to its edge and the non-coronary cusp was perforated. Neisseria mucosa endocarditis is very rare, and involves abnormal mitral or prosthetic valves predominantly. Infection of a native aortic valve, with no known history of disease, is exceptional.

Adult↗
PubMed1994

Analysis methods to improve the diagnostic power of treadmill exercise stress testing in patients with suspected angina pectoris.

To assess the ability of 3 established analysis methods in exercise stress electrocardiography to non-invasively detect the presence of coronary artery disease (CAD), 67 consecutive patients who had typical angina, positive exercise stress electrocardiography (ST segment depression > or = 1 mm) and coronary arteriography were studied. Thirty-three patients had significant CAD, and 34 had normal coronary arteriograms. The results showed that the Treadmill Score Method, utilising both ST and non-ST segment variables, had the highest accuracy in predicting disease. The predictive power of all 3 methods was lower in females.

Adult↗
PubMed1993

Effects of some non-steroidal anti-inflammatory drugs (NSAIDS) on steroidogenesis in rat and porcine testis.

Using the rapid gas chromatographic steroid profiling technique, a number of metabolites of pregnenolone have been separated and quantified after incubation of this steroid with adult rat and neonatal porcine testicular homogenates. It was shown that the 5-ene-3 beta-hydroxy- and the 4-en-3-oxosteroid pathways for androgen biosynthesis were operating in both species, although the former pathway appeared to be more important in porcine testis. This tissue was characterised by the formation of several odorous, and pheromonal, 16-androstenes, which were quantitatively more important than the androgens. Three non-steroidal anti-inflammatory drugs (NSAIDS) caused dose-related inhibition of androgen and 16-androstene biosynthesis when co-incubated with pregnenolone. The order of potency was flurbiprofen > indomethacin > > > aspirin. The possibility that the NSAIDS may interfere with cytochrome P-450 is discussed, since several steroid-transforming enzymes, known to be dependent on this cytochrome for their activity, were markedly inhibited.

Animals↗
PubMed1993

Review of patients with infective endocarditis of native valves over a five-year period.

The clinical characteristics, echocardiographic features, bacteriologic data, morbidity and mortality of patients who were admitted to our hospital with infective endocarditis of their native valves over a five-year period were reviewed. There were 32 patients with a mean age of 38.2 +/- 16.2 years (range: 17 to 71 years) in our study population; 24 patients had underlying valvular abnormalities, six patients had congenital heart disease and two patients had no structural cardiac abnormality. Echocardiography was performed for all patients. Vegetations were absent in three (9.4%) patients, single in 19 (59.4%) patients and multiple in ten (31.3%) patients. Of the 24 (75%) patients who had left-sided endocarditis, mitral valve disease was the commonest valvular abnormality (16 patients). Ventricular septal defect was the commonest underlying abnormality in patients with right-sided endocarditis. Blood cultures were positive in 26 (81.3%) patients; the commonest organism was streptococcal (16 or 50% patients). Complications were present in 13 (40.6%) patients, of which eight patients had evidence of embolism, four patients had cardiac failure and one patient had a paravalvular abscess. Four (12.5%) patients died, two as a result of refractory heart failure and two as a consequence of septic embolism. Advances in medicine have resulted in a better outcome for patients with infective endocarditis, however, it remains an important disease with significant morbidity and mortality.

Adolescent↗
PubMed1993

Interleukin-6 in experimental endometriosis.

OBJECTIVE: To measure the concentration of interleukin-6 (IL-6) in peripheral serum and conditioned media (CM) of macrophages collected from the peritoneal cavity in rats before and after surgically inducing endometriosis. DESIGN: Adult female rats (n = 50) underwent autotransplantation of adipose tissue or uterine squares. Peritoneal cavity macrophages were collected at the initial laparotomy. Rats were killed 4 or 8 weeks later, and peripheral serum and peritoneal cavity macrophages were collected. Macrophages were cultured for 48 hours, and the IL-6 concentrations in CM and serum were measured using the B9 hybridoma cell line bioassay. RESULTS: Serum IL-6 levels were significantly increased at 4 weeks but not at 8 weeks in rats receiving endometrial implants. Interleukin-6 production by macrophages from rats with endometrial implants at 4 or 8 weeks was not significantly different from baseline or from rats receiving adipose tissue implants. CONCLUSION: The increased serum IL-6 levels at 4 but not 8 weeks after surgical induction of endometriosis suggest that IL-6 may be involved in the initial development of endometriosis in this experimental model.

Animals↗
PubMed1992

Echocardiographic diagnosis of quadricuspid aortic valve.

Isolated quadricuspid aortic valve is a rare congenital anomaly. We present a case diagnosed on cross-sectional echocardiography. To the best of our knowledge, this is the first case report on echocardiographically diagnosed quadricuspid aortic valve in Singapore.

Aortic Valve↗
PubMed1992

A review of patients with a 'normal' coronary angiogram over a 3-year period.

Over a period of 36 months, we detected 54 patients with normal coronary arteries or non-critical coronary artery stenosis within our study series of coronary angiography. We studied these patients to determine their clinical, electrocardiographic, stress testing and angiocardiographic characteristics. We detected among them a preponderance of female sex and a higher incidence of ethnic Indians. The majority of the patients studied had one or more coronary risk factors. 52% had a normal resting ECG. In those with a positive stress test and reports available for review, there is a near equal distribution of horizontal and J-type ST depression. Those patients with a positive treadmill tend to have a higher left ventricular end diastolic pressure (LVEDP) at cardiac catheterization. We also noted in this group of patients a higher proportion with a small distal left anterior descending artery. These patients also tend to have higher LVEDP even in the presence of normal left ventriculogram. Our current series suggests the possibility of raised left ventricular end-diastolic pressure and the presence of a "small distal left anterior descending artery" syndrome in association with patients with a 'false positive' treadmill test.

Adult↗
PubMed1991

Spontaneous coronary artery dissection in a young man with anterior myocardial infarction.

A case of spontaneous coronary artery dissection in a young male with subsequent myocardial infarction is reported. In addition, distal vessel occlusion is noted, presumably from embolization of thrombotic material originating from the site of dissection. Postulated mechanisms of this uncommon cause of myocardial infarction and subsequent therapeutic options are reviewed.

Adult↗
PubMed1980

Comparison of three benzodiazepines for oral premedication in minor gynaecological surgery.

Diazepam 10 and 20 mg, lorazepam 2.5 and 5.0 mg, flunitrazepam 1 and 2 mg, and a placebo, were compared in a randomized double-blind controlled trial as oral premedication for 210 patients undergoing minor gynaecological surgery. Flunitrazepam 1 mg and lorazepam 2.5 mg were superior to placebo (P less than 0.001 and P less than 0.05 respectively) in relieving patient anxiety when assessed by a trained observer 60 min after premedication. Flunitrazepam 1 mg also produced more drowsiness (P less than 0.01) than the placebo. Comparisons of other low-dose benzodiazepine groups with the placebo, and of the large dose with the small dose of each drug revealed no significant changes in anxiolysis or drowsiness. Dizziness and prolonged drowsiness were not apparent with low-dose flunitrazepam. The data suggests that flunitrazepam 1 mg offers advantages over placebo, diazepam 10 mg and lorazepam 2.5 mg for routine oral premedication in minor gynaecological surgery.

Adolescent↗