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Biomedical subjects

S H Lim

Publications and source records attributed to S H Lim.

At least 55 records · Page 3Linked to original sources
PubMed2001

Mass cardiopulmonary resuscitation 99--survey results of a multi-organisational effort in public education in cardiopulmonary resuscitation.

Mass cardiopulmonary resuscitation (CPR) 99 in Singapore was a large-scale multi-organisational effort to increase awareness and impart basic cardiac life support skills to the lay public. Mass CPR demonstrations followed by small group manikin practice with instructor guidance was conducted simultaneously in three centres, four times a day. The exercise enlisted 15 community organisations and received the support of 19 other organisations. Three hundred and ninety-eight manikins and 500 instructors ('I's) were mobilised to teach an audience of 6000 participants ('P's). Two surveys, for 'I's and 'P's were conducted with respondent rates of 65.8% and 50%, respectively. 73.6% of the P-respondents ('P-R's) indicated that they attended the event to increase their knowledge. 66.9% were willing to attend a more comprehensive CPR course. Concerns and perceptions in performing bystander CPR were assessed.

Advertising↗
PubMed2001

No protective role of Helicobacter pylori in the pathogenesis of reflux esophagitis in patients with duodenal or benign gastric ulcer in Korea.

Little is known about the relationship between H. pylori infection and reflux esophagitis. To evaluate whether or not H. pylori plays a protective role in the pathogenesis of reflux esophagitis, the prevalence rates of reflux esophagitis depending on H. pylori status in consecutively diagnosed duodenal ulcer or benign gastric ulcer patients were evaluated. In addition, the incidence rates of reflux esophagitis depending on H. pylori status were evaluated for those patients who received follow-up endoscopy at least 6 months after eradication treatment. The prevalence rates of reflux esophagitis were 8.0% (2 patients) in the 25 H. pylori-negative duodenal ulcer group patients and 6.5% (36 patients) in the 555 H. pylori-positive duodenal ulcer group patients, and there was no statistical difference. Similarly, that of gastric ulcer patients was 9.4% (32 patients) in the 340 H. pylori-positive group patients, slightly higher than that in the 41 H. pylori-negative group patients 4.9% (2 patients), but without statistical significance. After eradication treatment the reflux esophagitis incidence rates were 2.5% (2 patients) in the 81 H. pylori-eradicated duodenal ulcer group patients and 7.7% (3 patients) in the 39 noneradicated duodenal ulcer group patients, and there was no statistical difference. Similarly, those of gastric ulcer patients were 6.8% (3 patients) in the 44 H. pylori-eradicated and 8.7% (2 patients) in the 23 noneradicated group patients again without statistical difference. These results suggest that H. pylori does not play a protective role in the pathogenesis of reflux esophagitis in patients with duodenal or gastric ulcer in Korea.

Adult↗
PubMed2001

Attenuation of inhibitory effect of CNP on the secretion of ANP from hypertrophied atria.

It has been shown that atrial natriuretic peptide (ANP) influences proliferation of cardiac cells. To define the possible role of C-type natriuretic peptide (CNP) in cardiac hypertrophy, the influence of CNP on the secretion of ANP was studied with the use of perfused nonbeating atria from monocrotaline-treated rats. Increases in atrial volume caused proportional increases in ANP secretion that were markedly suppressed by CNP (10(-6) M) in nonhypertrophied left atria and control right atria but not in hypertrophied right atria. However, increases in atrial volume and mechanically stimulated extracellular fluid (ECF) translocation by CNP were similar to those in the control group. Therefore, the secretion of ANP in terms of ECF translocation was decreased by CNP in nonhypertrophied left and control right atria but not in hypertrophied atria. However, the inhibitory effect of 8-bromo-cGMP on the secretion of ANP was observed in both atria. The cGMP productions from perfused hypertrophied atria and their membranes exposed to CNP were significantly lower than those from nonhypertrophied atria. No significant difference in natriuretic peptide receptor-B transcript was found. Therefore, attenuation of the inhibitory effect of CNP on the ANP secretion in hypertrophied atria may be due to lack of cGMP production. The results showing the relief of CNP-induced negative inhibition of ANP secretion by atrial hypertrophy suggest that CNP may be a contributing factor to delay the development of cardiac hypertrophy.

Animals↗
PubMed2001

Surgical treatment of digital ischemia occurred after radial artery catheterization.

Permanent ischemic injury of the hand after radial artery cannulation is rare, but several cases of thromboembolism after the cannulation leading to amputation of affected limb or digits have been reported. A 48-yr-old man undergoing spine surgery showed normal modified Allen's test and had no preoperative vascular disease. We inserted 20-G radial artery catheter for the continuous monitoring of the blood flow and serial blood sampling. There was no specific event during the operation and the catheter was removed immediately after the operation. The signs and symptoms of the circulatory impairment of the radial artery developed four days after the operation and aggravated thereafter. Through the angiographic study, we found the total occlusion of the radial artery and some of its branches. After an emergent surgical exploration of the radial artery for removal of the thrombus and vein graft for the defect of the artery on the 8th postoperative day, the ischemic signs and symptoms disappeared and the radial pulse was restored.

Catheterization, Peripheral↗
PubMed2001

Temporary tattooing followed by Q-switched alexandrite laser for treatment of syringomas.

BACKGROUND: Syringomas usually develop in women as multiple skin-colored papules primarily seen on the periocular regions and cheeks. They can cause cosmetic problems and lead to poor self-esteem. Though several treatment modalities have been established, such as excision, electro/cryosurgery, chemical peeling, and CO2 laser surgery, none of them are satisfactory due to their limitations and side effects, for example, pain, prolonged healing time, postoperative erythema/pigmentary changes, and scarring. OBJECTIVE: The objective of this study was to develop a new treatment method for syringoma and to minimize the side effects through selective destruction of the tumor. METHODS: Six patients with multiple periorbital syringomas were enrolled in this study. The surface epithelium of the syringomas was vaporized by CO2 laser, and black ink was introduced in order to allow penetration to the dermis using iontophoresis. Subsequently the artificial tattoos were removed by Q-switched alexandrite laser. The results were evaluated clinically by both physicians and patients at 1, 2, 4, and 8 weeks after treatment. RESULTS: The majority of syringoma in the six patients disappeared by the first follow-up 1 week after treatment. There were no cases of prolonged erythema persisting beyond 2 weeks. Additional treatment was repeated in the same manner in order to remove the remaining syringomas in one patient. There were no recurrences during the 8-week follow-up period. CONCLUSION: Our new treatment was safer, less painful, nonscarring, and there was a quicker recovery period and less of a burden to repeat treatment when necessary.

Adult↗
PubMed2001

Long-term results with St. Jude Medical and CarboMedics prosthetic heart valves.

BACKGROUND AND AIM OF THE STUDY: The clinical evaluation and comparison of St. Jude Medical (SJM) and CarboMedics (CM) prosthetic heart valves implanted between 1988 and 1997 is presented. METHODS: In total, 648 SJM valves were implanted in 641 patients, and 601 CM valves in 591 patients. There were 684 mitral valve replacements, 256 aortic valve replacements, 252 mitral and aortic (double) valve replacements, 16 triple valve replacements, and 41 other tricuspid-related valve replacements. Total follow up was 98%. The overall incidence of valve-related events was compared before and after establishment of a 'valve clinic' in 1993. RESULTS: The overall hospital mortality was 3.4%; late mortality was 8.2%. The five- and ten-year survival for all patients was 92.1% and 86.2%, respectively. There were 31 episodes of thromboembolism in 27 patients (including valve thrombosis in three), 21 episodes of bleeding events in 20 patients, and 18 re-replacements of implanted valves. No structural valve deterioration was observed. Freedom from thromboembolism was 97.8% at five years and 96.3% at ten years; freedom from bleeding episodes was 98.1% and 97.6%, respectively. In terms of hospital and late mortality, and incidence of thromboembolism, hemorrhagic episodes and structural valve failure, no statistically significant differences were found between the SJM and CarboMedics patient groups. Freedom from thromboembolism was 96.7% at five years before initiation of an intensive follow up program, and 99.0% thereafter (p = 0.031). In contrast, freedom from bleeding episodes fell from 99.3% to 96.1% during the same time period (p = 0.0004). CONCLUSION: Both the SJM and CM prosthetic heart valves performed well in our study, and no discernible differences in clinical performance of the two valves were detected. The intensive follow up program resulted in a reduced incidence of thromboembolism, but an increased number of bleeding complications. An optimum anticoagulation regimen to manage these two conflicting problems has yet to be elucidated.

Adolescent↗
PubMed2000

Long-term effects of Helicobacter pylori eradication on intestinal metaplasia in patients with duodenal and benign gastric ulcers.

This study was conducted to investigate whether or not the eradication of H. pylori could lead to the regression of intestinal metaplasia (IM) in patients with either duodenal ulcer (DU) or benign gastric ulcer (BGU). The initial antral IM grade was 0.21 in the 72 patients of the H. pylori-eradicated DU group, this decreased to 0.17, 0.14, 0.13, and 0.09 after periods of four weeks, one year, two years, and four years, respectively, but without statistical significance. In the corpus of the DU group, where IM grade was low (0.02), there was no detectable change in IM. The initial antral IM grade of 0.69 in the 41 patients of the H. pylori-eradicated BGU group decreased substantially to 0.61, 0.44, and 0.39 after periods of four weeks and one and two years, respectively, but again without statistical significance. The initial corporal IM grade of the BGU group of 0.27 decreased to 0.20, 0.15, and 0.06 after periods of four weeks and one and two years, again without statistical significance. In contrast, the IM grades of the noneradicated DU group (N = 20) and the BGU group (N = 16) showed nearly no change in the antrum and corpus. Gastritis grades of antrum and corpus in the H. pylori-eradicated DU or BGU group significantly decreased with respect to time (P = 0.0001), but there were no significant changes in the corresponding noneradicated groups. Although there was no statistical significance, IM decreased in the antrum and corpus of the stomach with BGU and in antrum of those with DU over a two to four-year period after H. pylori eradication, suggesting the possible reversibility of IM.

Adolescent↗
PubMed2000

Evaluation of the allergenicity of tropical pollen and airborne spores in Singapore.

BACKGROUND: Sensitization to pollen and spores of the Southeast Asian tropical region is not well documented. This study evaluated the allergenicity of the tropical airspora in Singapore. METHODS: On the basis of the results of an aerobiologic survey of the airspora profile of Singapore, crude extracts of 23 main spore (fungal and fern) and pollen types were prepared. A total of 231 patients with asthma and/or allergic rhinitis and 76 healthy controls were evaluated by skin prick test (SPT). Total and specific IgE levels were also quantified by the fluorescence allergosorbent test (FAST). RESULTS: All 23 allergenic extracts tested elicited positive SPT responses. Among the patients with atopic diseases, extracts of oil-palm pollen (Elaeis guineensis) were observed to have the highest frequency of positive reactions (40%), followed by extracts of resam-fern spores (Dicranopteris linearis) (34%) and sea-teak pollen (Podocarpus polystachyus) (33.8%). Fungal spores with the highest SPT responses were Curvularia spp. (26-32%) and Drechslera-like spores (31%). Positive responses to these extracts correlated with total serum IgE levels of the subjects and were significantly associated with the presence of atopic disease. CONCLUSIONS: We have documented sensitization to tropical pollen and spores in our population. Its association with atopy suggests that it has a role in allergic diseases in the tropics.

Adolescent↗
PubMed2000

Changes in chest electrode impedance.

The Prehospital Defibrillation Program in Singapore has in some cases shown a lower amplitude of ventricular fibrillation (VF) than considered the norm. The electrode skin impedance (ESI) refers to the skin impedance determined between two electrodes placed at specific positions on the body surface. The objective of this prospective study was to measure the ESI of patients at 5 Hz and 2 kHz frequencies, and assess its change with time from the application of electrodes, the difference between the ESI at two different sets of electrode placement positions, and correlation with patient factors. Patients who were 25 years or older and not critically ill had their ESI measured with a modified Heart-Save 911 defibrillator, using signal frequencies at 5 Hz and 2 kHz, at 10 seconds, 1 and 2 minutes after electrodes application. Two sets of positions were used; position 1 where an electrode is placed in the right subclavicular region and another just lateral to the apex beat on the left and position 2, which represents the mirror-image of position 1. Thirty-six each of men and women patients were studied. The mean age and weight were 59.9 +/- 13.5 years and 56.8 +/- 24.1 kg respectively. There was no significant correlation between the ESI and patients' body weight or sex. However, there was a significant decrease in the ESI with time from application of electrodes at both positions (P < .05) with the two different frequencies. The ESI was lower when measured at lower frequencies and higher when taken at higher frequencies, but there was no statistically significant difference between the two mirror-image positions used. Thus, with lower frequency, the electrocardiogram amplitude of VF recorded on the automated external defibrillator could be enhanced.

Adult↗
PubMed2000

Prediction of the clinical course of Behçet's colitis according to macroscopic classification by colonoscopy.

BACKGROUND AND STUDY AIMS: The lesions in Behçet's colitis show aphthoid or punched-out ulceration, but the macroscopic types of lesion found have not been defined. To predict the clinical outcome in patients with Behçet's colitis according to the colonoscopic findings, we classified the characteristic colonic ulcers, evaluated the efficacy of medical treatment on colonoscopic lesions, and calculated the operation rates and recurrence rates relative to the macroscopic types. PATIENTS AND METHODS: The medical records and colonoscopic photographs of 50 patients with Behçet's colitis were reviewed. The colonic lesions were examined by colonoscopy in patients with Behçet's disease and gastrointestinal symptoms. The colonoscopic findings were categorized into three types of ulceration: volcano-like, geographic, and aphthous. The efficacy of medical treatment was assessed by follow-up colonoscopy or double-contrast barium enema four to eight weeks after treatment, and recurrence of the lesions was evaluated during the follow-up periods. Cumulative surgery rates were obtained using the Kaplan-Meier method. RESULTS: The macroscopic classification of colonic ulcers identified 25 of 50 patients (50%) with volcano-type lesions, 11 (22%) with the geographic type, and 14 (28%) with the aphthous type. The rates of complete remission after medical treatment and surgery, respectively, were six of 25 (24%) and 13 of 25 (52%) with volcano-type ulcerations; eight of 11 (73%) and one of 11 (9%) with the geographic type; and nine of 14 (64%) and two of 14 (14%) with the aphthous type. The endoscopic and clinical recurrence rates were nine of 19 (47%) in volcano-type ulcerations, one of nine (11%) in the geographic type, and one of 11 (9%) in the aphthous type. CONCLUSION: Volcano-type ulcerations in Behçet's colitis showed a less favorable response to medical treatment, a more frequent requirement for surgery, and more frequent recurrences than the geographic and aphthous types of ulcerations.

Adult↗
PubMed2000

Difference in the distribution pattern of Helicobacter pylori and grade of gastritis in the antrum and in the body between duodenal ulcer and benign gastric ulcer patients.

OBJECTIVES: To investigate the relationship between the Helicobacter pylori (H. pylori) colonization and the grade of gastritis in the antrum and in the body of patients with duodenal ulcer (DU) or benign gastric ulcer (BGU). METHODS: This study was performed in H. pylori-positive 220 DU patients and 180 BGU patients. H. pylori density was evaluated by modified Giemsa staining and CLO test, and gastritis grade was graded by H&E staining in the antrum and in the body. RESULTS: H. pylori grade by Giemsa staining was 1.24 in the antrum and 0.82 in the body for DU group (p < 0.01), and those of BGU group were slightly reversed, 0.83 and 0.87, respectively, but without statistical significance. Similarly H. pylori grade by CLO test was 3.1 in the antrum and 2.8 in the body for DU group (p < 0.01), and those of BGU group 2.3 and 2.6 (p < 0.05), respectively. In contrast, gastritis grade was 1.7 in the antrum and 1.2 in the body for DU group (p < 0.01), and those of BGU group 1.6 and 1.3 (p < 0.01), respectively, similar to those of DU. However, there was a correlation between H. pylori grade and gastritis grade in the antrum and in the body, not only in DU but also in BGU group (p < 0.01). CONCLUSION: In spite of different distribution patterns of H. pylori between DU group and BGU group, gastritis grade of the antrum was significantly higher than that of the body in both DU and BGU. However, gastritis is correlated with H. pylori density not only in DU but also in BGU patients. It looks like the inflammatory reaction to H. pylori is stronger in the antrum than in the body.

Adult↗
PubMed2000

Helicobacter pylori in dental plaque and saliva.

BACKGROUND: About half of the world population is infected with H. pylori, but the transmission and the source of this infection are still unclear. Recently, dental plaque (DP) and saliva have been implicated as possible sources of H. pylori infection. This study was done to investigate the detection rates of H. pylori in the DP and saliva by use of PCR depending on H. pylori infection state of gastric mucosa. METHODS: In 46 subjects, gastric H. pylori colonization was evaluated with CLO test, microscopy of Gram stained mucosal smear, culture and histology after modified Giemsa staining in the antrum and body, respectively. A patient was regarded as H. pylori positive if one or more of the four aforementioned test methods demonstrated H. pylori colonization of the gastric mucosa. For detection of H. pylori in the DP and saliva, PCR assay was done with ET4-U and ET4-L primers. To estimate the sensitivity and specificity of this PCR, H. pylori positivity was evaluated in the antrum and body, separately. RESULTS: The sensitivity of mucosal PCR was 50.0% (27/54) and the specificity 86.8% (33/38). When a subject was regarded as H. pyloi positive, if either antrum or body mucosal H. pylori was is positive, the positive rate of mucosal PCR was 62.1% (18 subjects) in the 29 H. pylori-positive and 17.6% (3 subjects) in the 17 H. pylori-negative subjects. DP PCR was positive in 2 of 29 H. pylori-positive subjects (6.9%) and none in the 17 H. pylori-negative (0%). Saliva PCR was positive in 4 of 14 H. pylori-positive subjects (28.6%) and none of 6 H. pylori-negative (0%). CONCLUSION: The detection rates of H. pylori in DP and saliva by PCR were rather low, 6.9% and 28.6%, respectively, and these rates might have been underestimated by low sensitivity of the PCR method used in this study. However, the results that H. pylori was found in the DP and saliva suggest that the oral cavity can perform a role as a reservoir of H. pylori in Korea.

Dental Plaque↗
PubMed2000

Effects of different concentrations and volumes of formalin on pain response in rats.

BACKGROUND: Formalin test is commonly used in animal model to assess injury-produced pain response. If the total amount of formaldehyde is fixed, its concentration and volume can be easily adjusted. We evaluated the effect of two sets of three solutions of formalin (one set of same dose of formaldehyde at different concentration and volume, i.e. 2.5%--100 microL, 5%--50 microL, 10%--25 microL, and another set of same volume but at different concentrations, i.e. 2.5%--100 microL, 5%--100 microL, and 10%--100 microL) on the injury-produced pain response in rat. METHODS: Male Sprague-Dawley rats weighing 250-300 g were used. Following injection of formalin (n = 8 in each group) or saline (n = 6, control), the flinching frequencies and time spent in licking or biting the injected hind-paw in the early phase 1 (0-5 min after injection) and the late phase 2 (20-60 min after injection) were recorded. Sham-injection rats (n = 5) underwent subcutaneous insertion of the needle, but no substance was injected. RESULTS: Flinching in phase 1 and 2 was more frequent in the 2.5%--100 microL and 5%--50 microL groups than in the control group (P < 0.05). Licking (or biting) time in phase 2 in all these three groups was longer than the control group (P < 0.05). In the groups of another set of three different solutions (2.5%--100 microL, 5%--100 microL, and 10%--100 microL), flinching in phase 1 and phase 2 was also more frequent than the control group (P < 0.05). Regarding lick behavior of another set, it occurred more frequently in 2.5%--100 microL group in phase 1 and in 2.5%--100 microL group as well as 5%--100 microL group in phase 2 than the control group (P < 0.05). CONCLUSIONS: The 10%--25 microL formalin produces fewer flinching responses than other concentrations. Flinching was a biphasic behavior which was more spontaneous and active than was licking. The volume of formalin was a more important factor than the concentration of formalin in the generation of the active biphasic flinching response in the rat model.

Animals↗
PubMed2000

Chest impedance: characteristics of local patients.

The Pre-hospital Defibrillation Program in Singapore has in some cases demonstrated a lower amplitude of Ventricular Fibrillation (VF) than considered the norm. The Electrode Skin Impedance (ESI) refers to the skin impedance determined between two electrodes placed at specific positions on the body surface. The objective of this prospective study was to measure the ESI of patients at 5 Hz and 2 kHz frequencies, and assess its change with time from the application of electrodes, the difference between the ESI at two different sets of electrode placement positions and correlation with patient factors. Patients who were 25 years or older and not critically ill had their ESI measured with a modified Heart-Save 911 defibrillator, using signal frequencies at 5 Hz and 2 kHz, at 10 seconds, 1 and 2 minutes after electrodes application. Two sets of positions were used; Position 1 where an electrode is placed in the right infra-clavicular region and another just lateral to the apex beat on the left and Position 2, which represents the mirror image of Position 1. 36 each of male and female patients were studied. The mean age and weight were 59.9 +/- 13.5 years and 56.8 +/- 24.1 kg respectively. There was no significant correlation between the ESI and patients' body weight or sex. However, there was a significant decrease in the ESI with time from application of electrodes at both Positions (p < 0.05) with the two different frequencies. The ESI was lower when measured at lower frequencies and higher when taken at higher frequencies, but there was no statistically significant difference between the two mirror-image positions used. Thus, with lower frequency, the ECG amplitude of VF recorded on the automated external defibrillator could be enhanced.

Adult↗
PubMed2000

Prophylactic esmolol infusion for the control of cardiovascular responses to extubation after intracranial surgery.

INTRODUCTION: Emergence from general anaesthesia and extubation are often accompanied by significant surges in heart rate and blood pressure. To document these changes and the efficacy of low-dose beta-blocker infusions in ameliorating these rises, we undertook a descriptive dose-ranging study comparing the use of esmolol to placebo in patients emerging from neuro-anaesthesia. MATERIALS AND METHODS: Thirty-six patients undergoing intracranial surgery were randomised to receive saline, esmolol 100 micrograms/kg/min or 200 micrograms/kg/min infusions. The number of patients developing severe hypertension or tachycardia in each group was compared using Fisher's exact test. RESULTS: Systolic blood pressure (SBP) and heart rate (HR) increased in all 3 groups during emergence and peaked at extubation. The proportion of patients with severe tachycardia or hypertension was reduced from 92% in the placebo group to 40% (P = 0.02) and 8% (P = 0.001) in the low and intermediate dose esmolol groups, respectively. Results were better in the intermediate dose group but the difference was not statistically significant. Two patients from the esmolol infusion groups required supplemental medication for bradycardia. CONCLUSION: Severe hypertension or tachycardia occurs in 92% of patients during extubation following neuro-anaesthesia and warrants the consideration of routine prophylaxis. Prophylactic esmolol infusion for the control of haemodynamic disturbances during extubation is feasible and safe. A modest level of obtundation is evident at 100 micrograms/kg/min but a rate of 200 micrograms/kg/min may prove to be more effective.

Adrenergic beta-Antagonists↗