Biomedical subjects

K E Lee

Publications and source records attributed to K E Lee.

At least 37 records · Page 2Linked to original sources

PubMed1999

Outbreak of Nipah-virus infection among abattoir workers in Singapore.

BACKGROUND: In March 1999, an outbreak of encephalitis and pneumonia occurred in workers at an abattoir in Singapore. We describe the clinical presentation and the results of investigations in these patients. METHODS: Clinical and laboratory data were collected by systemic review of the case records. Serum and cerebrospinal fluid (CSF) samples were tested for IgM antibodies to Nipah virus with an IgM capture ELISA. Reverse-transcriptase PCR was done on the CSF and tissue samples from one patient who died. FINDINGS: Eleven patients were confirmed to have acute Nipah-virus infection based on raised IgM in serum. Nipah virus was identified by reverse transcriptase PCR in the CSF and tissue of the patient who died. The patients were all men, with a median age of 44 years. The commonest presenting symptoms were fever, headache, and drowsiness. Eight patients presented with signs of encephalitis (decreased level of consciousness or focal neurological signs). Three patients presented with atypical pneumonia, but one later developed hallucinations and had evidence of encephalitis on CSF examination. Abnormal laboratory findings included a low lymphocyte count (nine patients), low platelet count, low serum sodium, and high aspartate aminostransferase concentration (each observed in five patients). The CSF protein was high in eight patients and white-blood-cell count was high in seven. Chest radiography showed mild interstitial shadowing in eight patients. Magnetic resonance imaging (MRI) showed focal areas of increased signal intensity in the cortical white marker in all eight patients who were scanned. The nine patients with encephalitis received empirical treatment with intravenous aciclovir and eight survived. INTERPRETATION: Infection with Nipah virus caused an encephalitis illness with characteristic focal areas of increased intensity seen on MRI. Lung involvement was also common, and the disease may present as an atypical pneumonia.

Abattoirs↗

PubMed1999

Associations of performance-based and self-reported measures of visual function. The Beaver Dam Eye Study.

OBJECTIVE: To describe and compare performance-based and self-reported measures of visual function and to evaluate how each varied with age and how the performance-based measures were associated with the responses to self-reported questions about visual function. DESIGN: Population-based epidemiologic study. PARTICIPANTS: Adults participating in the first follow-up of the Beaver Dam Eye Study (n = 3,722). MAIN OUTCOME MEASURES: Performance-based measures of vision including current binocular, best-corrected and near visual acuities, sensitivity to light as measured by an automated perimeter, contrast sensitivity, and self-reported measures from a standardized interview. RESULTS: All performance-based and self-reported visual functions decreased with increasing age (p < 0.0001 for each). On average, women did more poorly than men on all the performance-based measures (p < 0.0001 for each), and on some of the self-reported measures. For both genders, correlations among the performance-based measures ranged from 0.38 to 0.67. In general, individuals reporting good visual function or little difficulty with visual tasks scored better on performance-based measures compared to individuals whose questionnaire responses reflected limited visual function. Overall, about 39% of drivers reported that their vision caused them to limit their night driving. Correlations of performance-based with self-reported measures of visual function were greater for best-corrected, binocular and near visual acuity compared to correlations of visual sensitivity to light and contrast sensitivity. There were 1,285 persons whose best-corrected acuity was better than their current binocular acuity and there were 97 people with visual impairment considering only current binocular acuity whose vision improved to better than 20/40 after refraction. CONCLUSIONS: Performance-based and self-reported measures of visual function were consistently and inversely related to age. Performance-based measures were, in general, more highly correlated between themselves than were self-reported measures. Self-reported visual functions were significantly positively correlated with all performance-based measures, but correlations were moderate. While high contrast measures are usually used in clinical settings and in many studies, the data suggest that in assessing function it is appropriate to measure several different aspects of vision, both performance-based and self-assessed. Our data give some indication of the impact these visual functions have on daily life as reflected by night driving and on near and distant visual acuity. New refractive corrections would likely improve the visual acuity in many older adults.

Adult↗

PubMed1999

Incident cataract after a five-year interval and lifestyle factors: the Beaver Dam eye study.

CONTEXT: A population-based study to investigate risk factors for age-related eye disease was begun in 1987 in a representative American community. Incidence of cataract was subsequently evaluated. SPECIFIC OBJECTIVES: To examine the relationships of cigarette smoking, alcohol, and caffeine intakes to incidence of age-related cataracts five years later. DESIGN: Observational epidemiologic incidence study of an adult population. PARTICIPANTS AND INTERVENTION: Adults 43-84 years of age were identified during a census in 1987-1988, and examined at baseline (1988-1990) and after a five-year interval (1993-1995). MAIN OUTCOME MEASURE: Standardized protocols were used at the baseline and follow-up evaluations for exposures and for objective identification of cataracts. RESULTS: Cumulative incidence of nuclear cataract in right eyes was about 12%, cortical cataract about 8%, and posterior subcapsular cataract about 3%. In multivariable analyses of the general estimating equations type, there were significant associations between nuclear cataract and: pack-years smoked (odds ratio [OR] 1.05, 95% confidence interval [CI] 1.01, 1.09 per 10 pack-years); and current alcohol intake (OR 1.01, 95% CI 1.00, 1.02 per 10 grams ethanol/week). Cigarette smokers were more likely to have had cataract surgery in the interval between baseline and follow-up examinations. CONCLUSIONS: Cigarette smoking and alcohol consumption were associated with modestly increased risks of incident nuclear cataract over a five-year interval.

Adult↗

PubMed1999

Correlates of urinary symptom scores in men.

OBJECTIVES: This study determined the prevalence of urinary symptoms and their relationship to characteristics of a cohort of men in Beaver Dam, Wis, from 1993 to 1995. METHODS: A standardized questionnaire concerning urinary symptoms (the American Urological Association Urinary Symptom Questionnaire) was administered. RESULTS: All outcomes were associated with age and history of enlarged prostate. Urinary frequency (57%) and nocturia (65%) were the most common individual symptoms. Diuretic usage, diabetes, history of cardiovascular disease, and smoking were related to specific symptoms. CONCLUSIONS: While urinary symptoms are associated with age and history of enlarged prostate, symptoms may also be attributable to other diseases and exposures.

Age Factors↗

PubMed1999

[Elevation of serum and urine tumor necrosis factor levels after transurethral resection of the prostate].

BACKGROUND: Recent studies have suggested that inflammatory cytokines are major mediator of the acute phase protein response after surgery. The aim of the present study is to investigate the relationship between the degree of surgical trauma and the change of serum and urine cytokine levels after transurethral resection of the prostate (TUR-P). METHOD: Serum and urine concentrations of tumor necrosis factor-alpha (TNF), interleukin-6 (IL 6), and interleukin-1 (IL 1) were evaluated in 55 patients who underwent TUR-P and in 23 patients who underwent abdominal surgery. The samples were collected periodically before and after an intervention, and the concentrations of cytokines were measured by enzyme-linked immunosorbent assay. RESULTS: The concentration of serum TNF was significantly increased 6 hours after TUR-P. Since serum TNF level was not increased after abdominal surgery, serum TNF level was significantly higher after TUR-P than after abdominal surgery. Serum IL 6 and IL 1 levels were not increased after TUR-P. Urine levels of TNF, IL 6 and IL 1 were significantly increased after TUR-P, meanwhile no significant elevation of urine cytokine levels was recognized in the patients who underwent abdominal surgery. The elevation of urine cytokine levels was thought to be caused by the increased production of cytokines at the surgically resected sites. The urine TNF level after TUR-P was increased related to the resected tissue volume and irrigation fluid volume. The preoperative urinary tract infection caused excessive elevation of the urine TNF level after TUR-P. The urine TNF level after TUR-P also tended to be increased depending on the degree of postoperative pyrexia. CONCLUSION: These results indicate the unique response of TNF to TUR-P. Measurement of serum and urine TNF levels after TUR-P can be a useful index for evaluating the perioperative condition of the patients undergoing TUR-P.

Adult↗

PubMed1999

Changes in refractive error over a 5-year interval in the Beaver Dam Eye Study.

PURPOSE: To examine changes in spherical equivalent over a 5-year period in persons 43 to 84 years of age. METHODS: All people 43 to 84 years of age and living in Beaver Dam, Wisconsin, in 1988 were invited for a baseline examination (1988-1990) and a 5-year follow-up examination (1993-1995). Refractions were determined according to the same protocol at both examinations. Aphakic and pseudophakic eyes were excluded as well as eyes with best corrected Snellen visual acuity of 20/40 and worse. After exclusions, refraction was obtained on 3007 right eyes and 3012 left eyes of the 3684 people participating in both examinations. RESULTS: Right and left eyes behaved similarly. Spherical equivalent became more positive in the youngest subjects and more negative in older subjects. After adjusting for other factors, the 5-year change in spherical equivalent of those 45, 55, 65, and 75 years of age was +0.15, +0.18, +0.10, and -0.07D, respectively. Severity of nuclear sclerosis was related to the amount of change. Those with mild nuclear sclerosis at baseline had a change of +0.2 D, whereas those with severe nuclear sclerosis had a change of -0.5 D. The amount of change was also related to gender, diabetes, and age at onset of myopia. It was unrelated to education and baseline spherical equivalent. CONCLUSIONS: Changes in spherical equivalent over a 5-year period were small. Before the age of 70, people became more hyperopic. After the age of 70, people became more myopic. Much of the myopic change may be related to increasing nuclear sclerosis.

Adult↗

PubMed1999

The neurological manifestations of Nipah virus encephalitis, a novel paramyxovirus.

A novel Hendra-like paramyxovirus named Nipah virus (NiV) was the cause of an outbreak among workers from one abattoir who had contact with pigs. Two patients had only respiratory symptoms, while 9 patients had encephalitis, 7 of whom are described in this report. Neurological involvement was diverse and multifocal, including aseptic meningitis, diffuse encephalitis, and focal brainstem involvement. Cerebellar signs were relatively common. Magnetic resonance imaging scans of the brain showed scattered lesions. IgM antibodies against Hendra virus (HeV) were present in the serum of all patients. Two patients recovered completely. Five had residual deficits 8 weeks later.

Adult↗

PubMed1999

Meningoencephalitis caused by a novel paramyxovirus: an advanced MRI case report in an emerging disease.

Eleven abattoir workers in Singapore were infected in March 1999 by an outbreak caused by the Nipah virus. This newly discovered, Hendra-like paramyxovirus causes acute infection of the CNS. We present the magnetic resonance imaging (MRI) and proton magnetic resonance spectroscopy (MRS) findings in a patient suffering from acute meningoencephalitis. Multiple small white matter lesions were detected on diffusion-weighted imaging (DWI) and T2-weighted images. There were no abnormalities detected on MRS. We believe this to be the first reported MRI findings in this novel zoonotic viral disease.

Abattoirs↗

PubMed1999

Comparison of the grade of CIN in colposcopically directed biopsies with that in outpatient loop electrosurgical excision procedure (LEEP) specimens--a retrospective review.

BACKGROUND: It has been suggested that LEEP should be the standard for the diagnosis of cervical dysplasia, rather than colposcopically directed biopsy as traditionally so, since it is both diagnostic and therapeutic. PATIENTS: Seventy-eight patients who underwent LEEP at the Gynaecological Cancer Centre, KK Hospital from 1 January 1995 to 31 December 1997 for cervical dysplasia diagnosed by colposcopically directed biopsy were retrospectively reviewed. The mean age of the patients was 40.3 years (SD 8.4), with 78.2% of them with CIN I or CIN II. The mean operating time was 11.8 minutes (SD 4.9) and 53.8% (42/78) were given prophylactic antibiotics, with the only complication being moderate postoperative haemorrhage in 3.8% (3/78). The mean follow-up period was 19.1 months (SD 9.3) with the cure rate being 97.4% (76/78). RESULTS: Only half of the patients had corresponding histologies on biopsy and LEEP, with 28.2% (22/78) undergraded and 21.8% (17/78) overgraded. CONCLUSION: Significant discrepancies may be found between the results of colposcopically directed biopsy and loop excision, and LEEP, which is safe and effective may be the choice procedure for the diagnosis of cervical dysplasia.

Adult↗

PubMed1999

Outpatient procedures for cervical dysplasia: a 3 year review of laser vaporisation and LEEP.

A 3 year retrospective review (1995 to 1997) of 127 patients with cervical dysplasia who underwent Laser Vaporisation of the cervix and LEEP at the Gynaecological Cancer Centre, KK Women's & Children's Hospital, Singapore, was undertaken. Amongst the patients in the Laser Vaporisation group, the mean age was 37.7 years (SD 8.8), the mean operating time was 14.8 minutes (SD 8.5), 63.6% were given prophylactic antibiotics and the mean follow up period was 15.3 months (SD 12.0), whilst in the LEEP group, mean age was 40.3 years (SD 8.4), mean operating time, 11.8 minutes (SD 4.9), prophylactic antibiotic rate, 53.8% and mean follow up period was 19.1 months (SD 9.3). Mild and moderate haemorrhage post procedure were the only complications encountered, 10.2% (5/49) in the Laser group and 3.8% (3/78) in the LEEP group. 98% (48/49) and 97.4% (76/78) of the Laser and LEEP groups, respectively, were free of disease on follow up. None of the 3 patients with persistent or recurrent disease were diagnosed as having invasive cancer. Overall, there were no significant differences in the patient characteristics, histopathology, operating times, follow up period, the use of prophylactic antibiotics, and complications in the 2 groups. The low complication rate, high disease-free rate and the relatively short operating time of Laser Vaporisation and LEEP in our study suggests that, indeed, both the procedures can be done safely and efficiently in the outpatient setting. However the discrepancy between the histology of colposcopically directed biopsy and that of LEEP specimens suggests that colposcopically directed biopsy may not be as accurate as one might believe, and further studies analysing the concordance between colposcopically directed biopsy and LEEP biopsy histologies are needed.

Adult↗

PubMed1998

Incidence of age-related cataract: the Beaver Dam Eye Study.

OBJECTIVE: To estimate the incidence of nuclear, cortical, and posterior subcapsular cataract in the Beaver Dam Eye Study cohort. DESIGN: A population-based study of the prevalence of age-related eye diseases was conducted between 1988 and 1990 (n=4926), and a follow-up study was conducted between 1993 and 1995 (n=3684). The evaluations included photographic documentation of the lens. Slitlamp photographs were taken to assess nuclear opacity, and retroillumination photographs were taken to assess cortical and posterior subcapsular cataract. The grading of photographs was done in a masked manner by trained graders using the same protocols for baseline and follow-up photographs. The graders were the same for both evaluations. PARTICIPANTS: Persons aged 43 to 86 years who were identified through a private census conducted from 1987 to 1988 of the population of Beaver Dam, Wis, were invited for a baseline examination held between 1988-1990 and again for a follow-up examination held between 1993-1995. RESULTS: Incident nuclear cataract occurred in 13.1%, cortical cataract in 8.0%, and posterior subcapsular cataract in 3.4% of right eyes. The cumulative incidence of nuclear cataract in right eyes increased from 2.9% in persons aged 43 to 54 years at baseline to 40.0% in those aged 75 years or older. For cortical and posterior subcapsular cataract, the corresponding values were 1.9% and 21.8% and 1.4% and 7.3%, respectively. Women were more likely than men to have nuclear cataract even after adjusting for age. CONCLUSIONS: Incident cataracts are common age-related problems, and incidence increases with increasing age at baseline. These data will help in planning for future care (eg, cataract surgery and change in spectacle correction) and in investigating the importance of risk factors.

Adult↗

PubMed1998

Diabetes, cardiovascular disease, selected cardiovascular disease risk factors, and the 5-year incidence of age-related cataract and progression of lens opacities: the Beaver Dam Eye Study.

PURPOSE: To describe the relationships of diabetes mellitus, cardiovascular disease, and selected cardiovascular disease risk factors to cumulative incidence of age-related cataract and to progression of lens opacities over a 5-year interval. METHODS: A follow-up examination of the Beaver Dam Eye Study cohort was performed 5 years after the baseline evaluation. Ages at the census prior to baseline ranged from 43 to 84 years of age. Protocols for examination, lens photography, and grading were the same for both examinations. RESULTS: Age at baseline was the most significant characteristic associated with incidence of nuclear, cortical, and posterior subcapsular cataract in those without diabetes (P < .001) for all cataracts. The positive association of age with cataract was found for nuclear and cortical cataract in the worse eye (P < or = .04) but not posterior subcapsular cataract in those with diabetes. Progression of nuclear sclerosis was common, occurring in about 70% of subjects when considering either eye. Incident cortical and posterior subcapsular cataracts (P < or = .001 for worse eye for each lesion) and progression of cortical and posterior subcapsular opacities were more common in those with diabetes (P < or = .001 for either eye for each lesion). Increased glycated hemoglobin level was associated with increased risk of nuclear and cortical cataracts in those with diabetes. Relationships of risk factors to posterior subcapsular cataracts, especially among those with diabetes, were often in the expected direction but lacked significance possibly due to small samples. CONCLUSIONS: Diabetes mellitus is associated with incidence over 5 years of cortical and posterior subcapsular cataract and with progression of more minor cortical and posterior subcapsular lens opacities. These changes may be related to level of glycemia. Cardiovascular disease and its risk factors have little effect on incidence of any age-related cataract.

Adult↗

PubMed1998

Performance-based and self-assessed measures of visual function as related to history of falls, hip fractures, and measured gait time. The Beaver Dam Eye Study.

OBJECTIVE: The purpose of the study is to report relationships between visual function parameters and falls, hip fractures, and gait time in adults. DESIGN: Population-based study. PARTICIPANTS: The 3722 persons who participated in the 5-year follow-up of the Beaver Dam Eye Study cohort. MAIN OUTCOME MEASURES: The visual functions measured at the examination were best-corrected visual acuity, current binocular acuity, near acuity, contrast sensitivity, and visual threshold to light. Information on falls and hip fractures was obtained by structured interview. Gait time was measured by standardized protocol. RESULTS: History of falls and hip fractures increased with age, as did time to walk a measured course. Falls were more commonly reported for all persons who had poorer visual function, although not all relationships were significant in persons less than 60 years of age. In persons 60 years of age and older, hip fractures after the age of 40 were significantly related to all measures of visual function. Time to walk a measured course was significantly related to all measures of visual function. CONCLUSIONS: These data indicate a consistent relationship between falls, fractures, gait time, and visual functions. Longitudinal data are necessary to accurately determine temporal relationships and to determine the likelihood of a causal association. In the interim, these data suggest that improving visual function may have benefits such as decreased traumatic events and improved mobility.

Accidental Falls↗

PubMed1998

Creutzfeldt-Jakob disease presenting with visual blurring, diplopia and visual loss: Heidenhain's variant.

Focal electroencephalographic abnormalities as described in Heidenhain's variant of Creutzfeldt-Jakob disease are uncommon. We report a 73-year-old male presenting with visual symptoms, right hemianopia and rapidly progressive dementia. Myoclonus was synchronous with generalised periodic epileptiform discharges on electroencephalography (EEG). In addition, there were periodic focal sharp waves at the left occipital region. Diffusion-weighted magnetic resonance brain images showed slightly increased signal intensity in the occipital parasagittal area, left more than right. 14-3-3 protein was detected in the cerebrospinal fluid. The patient died within 5 months of presentation.

Aged↗

PubMed1998

Renal function abnormalities and incident cataract after a five-year interval: The Beaver Dam Eye Study.

PURPOSE: To evaluate the relationship between renal function abnormalities and incidence of age-related cataract. METHODS: In a population-based epidemiologic study of age-related eye disease, cataract was classified based on lens photographs. Standard methods of grading were used. Blood urea nitrogen, serum creatinine, and gross proteinuria were measured using standard protocols. RESULTS: Cortical cataract was associated with increased BUN, but after controlling for age, this relationship was no longer significant. In those with diabetes, elevated BUN or elevated creatinine was associated with increased odds of posterior subcapsular cataract, but these relationships were not significant. CONCLUSION: Renal function abnormalities were not significantly associated with incidence of cataract after controlling for age and gender. However, the power to test these associations was limited. Further longitudinal follow-up of this cohort as well as other studies designed to evaluate these associations are needed.

Adult↗

PubMed1997

Cardiovascular disease, selected cardiovascular disease risk factors, and age-related cataracts: the Beaver Dam Eye Study.

PURPOSE: To examine the associations of cardiovascular disease and selected cardiovascular disease risk factors with the prevalence of age-related cataract. METHODS: We conducted a population-based prevalence study of adults aged 43 to 86 years (n = 4,926) in Beaver Dam, Wisconsin. An ocular examination including lens photographs, medical history, height and weight measurement, blood testing, and photograph grading was performed according to standard protocols. RESULTS: Age and sex influenced most of the relationships between risk variables and cataract. Many relationships apparent in univariate analyses were not significant when controlling for confounders. In multivariate models, higher glycated hemoglobin was significantly and consistently associated with increased risk of nuclear cataract in women. For cortical cataract, higher serum high density lipoprotein cholesterol was associated with decreased risk in women. For posterior subcapsular cataract, men with higher ratios of total to high-density lipoprotein cholesterol were at increased risk. History of cardiovascular disease was not associated with cataracts in persons with or without diabetes after controlling for additional risk indicators. CONCLUSIONS: Some risk factors for cardiovascular disease were associated with increased frequency of age-related lens opacities. Age and sex influenced these relationships but did not entirely explain them. Longitudinal follow-up is necessary to determine antecedent-consequent relationships that may suggest causal associations.

Adult↗

PubMed1997

A two-component system in Ralstonia (Pseudomonas) solanacearum modulates production of PhcA-regulated virulence factors in response to 3-hydroxypalmitic acid methyl ester.

Expression of virulence factors in Ralstonia solanacearum is controlled by a complex regulatory network, at the center of which is PhcA, a LysR family transcriptional regulator. We report here that expression of phcA and production of PhcA-regulated virulence factors are affected by products of the putative operon phcBSR(Q). phcB is required for production of an extracellular factor (EF), tentatively identified as the fatty acid derivative 3-hydroxypalmitic acid methyl ester (3-OH PAME), but a biochemical function for PhcB could not be deduced from DNA sequence analysis. The other genes in the putative operon are predicted to encode proteins homologous to members of two-component signal transduction systems: PhcS has amino acid similarity to histidine kinase sensors, whereas PhcR and OrfQ are similar to response regulators. PhcR is quite unusual because its putative output domain strongly resembles the histidine kinase domain of a sensor protein. Production of the PhcA-regulated factors exopolysaccharide I, endoglucanase, and pectin methyl esterase was reduced 10- to 100-fold only in mutants with a nonpolar insertion in phcB [which express phcSR(Q) in the absence of the EF]; simultaneously, expression of phcA was reduced fivefold. Both a wild-type phenotype and phcA expression were restored by addition of 3-OH PAME to growing cultures. Mutants with polar insertions in phcB or lacking the entire phcBSR(Q) region produced wild-type levels of PhcA-regulated virulence factors. The genetic data suggest that PhcS and PhcR function together to regulate expression of phcA, but the biochemical mechanism for this is unclear. At low levels of the EF, it is likely that PhcS phosphorylates PhcR, and then PhcR interacts either with PhcA (which is required for full expression of phcA) or an unknown component of the signal cascade to inhibit expression of phcA. When the EF reaches a threshold concentration, we suggest that it reduces the ability of PhcS to phosphorylate PhcR, resulting in increased expression of phcA and production of PhcA-regulated factors.

Amino Acid Sequence↗

PubMed1997

[A case of spontaneous repair of the ureteral rupture caused by ureteral carcinoma].

We report a 47-year-old male patient with a spontaneous ureteral rupture caused by ureteral carcinoma. Drip infusion pyelography (DIP) and computerized tomography (CT) demonstrated the extravasation of contrast medium around the dilated upper ureter. Nephrostography showed the extinction of extravasation 4 days after the DIP. A total nephroureterectomy with the excision of a cuff of bladder was performed for the transitional cell carcinoma of the right lower ureter. Meticulous pathological examination of the specimen revealed discontinuity of the muscle layer, edema and fibrin deposition in the submucosal layers in the upper ureter indicating the site of the rupture. These findings suggest that the spontaneous rupture of the ureter caused by the ureteral carcinoma could be spontaneously repaired in a short period.

Carcinoma, Transitional Cell↗