Biomedical subjects

S K Tse

Publications and source records attributed to S K Tse.

10 recordsLinked to original sources

PubMed1999

How good are accident and emergency doctors in the evaluation of psychiatric patients?

The aim of this study was to find out the agreement between psychiatrists and emergency department (ED) doctors in the diagnosis and treatment of psychiatric emergencies. All patients presenting with a psychiatric complaint and who were subsequently referred to the psychiatrist were included. A standard form was used to collect demographic data, provisional diagnoses and initial treatment by ED doctors, diagnoses by psychiatrists, and compatibility of ED diagnoses and treatment as judged by consulting psychiatrists. The mean age of the 223 patients enrolled was 36.5 years and the distribution between males and females was roughly equal. The most frequent presentations were aggressive behaviour (27.9%), depressive mood (13.5%) and suicidal idea (12.1%). Schizophrenia (39%) was the most common diagnosis followed by depression (20%) and adjustment disorders (9.5%). The agreements between psychiatrists and ED doctors in diagnosis and treatment were 61.4% and 89.5% respectively. Schizophrenia and bipolar disorders were least likely to be mis-classified. It is concluded that ED doctors were deficient in the diagnosis of psychiatric conditions especially in the less common diagnostic categories.

Adult↗

PubMed1998

In vitro bovine ciliary body/epithelium in a small continuously perfused Ussing type chamber.

Our goal is to assess the viability of an in vitro preparation of bovine ciliary body/epithelium (CBE) in a small volume Ussing-type chamber. A new small volume Ussing-type chamber with continuous perfusion was developed for bovine CBE. The trans-CBE electrical parameters were monitored and the electrical responses of the CBE to ouabain (1 and 0.01 mM) were recorded. The trans-CBE fluxes of [14C]-L-ascorbate and [3H]-L-glucose were also studied. The bovine CBE preparation was stable inside the chamber in terms of its potential difference (PD), short circuit current (SCC) and trans-CBE resistance. They were -0.51+/-0.05 mV (aqueous side negative), -5.43+/-0.04 microAcm-2 and 94+/-2 Q.cm2 (mean s.e.m., n=35), respectively. The preparation hyperpolarised when 0.01 mM ouabain was administered to the aqueous side, depolarised when ouabain was applied to the stromal side. [3H]-L-glucose diffusion was about 74 nEq h(-1)cm(-2) in either direction (n=12). Taking the area magnification factor of the CBE into consideration, the diffusional L-glucose flux across the bovine CBE was comparable to other tight epithelia. A significant net ascorbate flux (0.26+/-0.05 nEq h(-1)cm(-2), n=4, p<0.01) was found in the stroma to aqueous direction. We have developed a viable in vitro bovine CBE preparation which was (1) electrically stable, (2) responsive to ouabain, (3) tight to L-glucose diffusion, and (4) capable of actively secreting ascorbate. A net trans-CBE chloride transport (0.81+/-0.30 microEq h(-1)cm(-2), n=12, p=0.01) from stromal to aqueous side was found in the present in vitro model under short-circuited conditions.

Animals↗

PubMed1995

On model selection for standard curve in assay development.

This paper discusses the selection of an appropriate statistical model for representing standard curve in assay development. This is an important issue in assay validation because the accuracy and reliability of the assay result depend on the selected standard curve. In this study, we propose a selection procedure, which is based on the R2 and the mean squared error of the estimation sample, to determine the "best" model. An example concerning an assay validation study is used to illustrate the application of the proposed procedure to discriminate among the five commonly used statistical models.

Calibration↗

PubMed1993

Fine-needle aspiration of cutaneous malakoplakia.

A 99-yr-old Chinese woman with cutaneous malakoplakia and concomitant urinary tract infection was reported. The patient presented with an ulcerated right lower quadrant mass and computerized tomography showed that it was limited to the skin and subcutaneous tissue with no extension to the pelvic or abdominal structures. The patient also suffered from urinary tract infection and was treated with oral norfloxacin. The ulcerated subcutaneous mass disappeared on follow-up visit 6 months after presentation. The cytologic (fine-needle aspiration), histologic (trucut biopsy) and ultrastructural features of cutaneous malakoplakia were described. The possible usefulness of fine-needle aspiration in the diagnosis of this condition was discussed.

Abdomen↗

PubMed1992

Biochemical characterization of rat colonic mucins secreted in response to Entamoeba histolytica.

Invasion of the colonic mucosa by Entamoeba histolytica trophozoites is preceded by colonic mucus depletion. The aim of our studies was to determine whether E. histolytica caused a differential secretion of mucin species in a rat colonic loop model. Mucus secretion in response to amoebae was followed by release of acid-precipitable 3H-glucosamine metabolically labelled glycoproteins and in vitro labelling of glycoprotein secretion with NaB3H4. The secretory response consisted of high-Mr goblet cell mucins and an increase in the secretion of low-Mr nonmucin glycoproteins as determined by Sepharose 4B column chromatography. High-Mr mucins subfractionated by Cellex-E (ECTEOLA) ion-exchange chromatography demonstrated a minor neutral and a major acidic mucin (greater than 98%) species. Marked differences between the neutral and acidic mucin species were indicated by immunogenicity and amino acid compositions. Thin-section histochemistry of rat colons confirmed secretion of neutral and acidic mucins in response to E. histolytica and demonstrated secretory activity from goblet cells from both the crypts and interglandular epithelium. E. histolytica mucus secretagogue activity was generalized and may function to deplete the host's protective mucus layer, facilitating invasion by the parasites.

Amino Acids↗

PubMed1992

T'ai chi and postural control in the well elderly.

In this study, we investigated the potential value of t'ai chi in promoting postural control of the well elderly. T'ai chi, a traditional Chinese exercise, is a series of individual dancelike movements linked together in a continuous, smooth-flowing sequence. Performance on five balance tests of 9 t'ai chi practitioners was compared to that of 9 nonpractitioners. An analysis of variance demonstrated that in three of the tests, the t'ai chi practitioners had significantly better postural control than the sedentary nonpractitioners (p less than .05). It was also found that men performed significantly better than women in both the practitioner and non-practitioner groups on the same three tests (p less than .01).

Aged↗

PubMed1991

On the estimation of total variability in assay validation.

In the pharmaceutical industry, an assay method is considered validated if the accuracy and precision for an assay meet some acceptable limits. This paper discusses the assessment of assay precision in terms of the estimation of total variability of an assay from a one-way random effects model which is often considered in assay validation. We propose a general class of estimators that includes the analysis of variance estimator and the maximum likelihood estimator. We derive the optimal estimator, in terms of smallest mean squared error, within this class and consider an approximate version of this optimal estimator. We report on a Monte Carlo simulation to study its finite sample performance. We also present two examples to illustrate the use of the proposed methodology.

Analysis of Variance↗

PubMed1991

The interaction between intestinal mucus glycoproteins and enteric infections.

Adherence of pathogenic enteric organisms to specific receptors on mucosal surfaces is widely recognized as an important first step in the initiation of infectious diseases. The specific interactions whereby parasites and bacteria exploit mucus substrates for colonization, and the host uses them as a nonimmunological defense mechanism, is only now being unravelled. In this review, Sil-King Tse and Kris Chadee discuss various hypothetical models for interaction, including the role of the immune system in the regulation of mucus secretion.

Journal Article↗

PubMed1990

Outlier detection in bioavailability/bioequivalence studies.

This paper concerns techniques for detection of a potential outlier or extreme observation in a bioavailability/bioequivalence study. A bioavailability analysis that includes possible outlying values may affect the decision on bioequivalence. We consider a general crossover model that takes into account period and formulation effects. We derive two test procedures, the likelihood distance and the estimates distance, to detect potential outliers. We show that the two procedures relate to a chi-square distribution with three degrees of freedom. The main purpose of this paper is to exhibit and discuss these two general approaches of outliers detection in the context of a bioavailability/bioequivalence study. To illustrate these approaches, we use data from three-way crossover experiment in the pharmaceutical industry that concerned the comparison of the bioavailability of two test formulations and a standard (reference) formulation of a drug. This example demonstrates the influence of an outlying value in the study of bioequivalence.

Analysis of Variance↗

PubMed1986

Effects of exercise-training on the thermic effect of food and body fatness of adult women.

Resting metabolic rate (RMR), thermic effect of food (TEF), aerobic capacity (VO2max), body fat, and food intake were measured in 10 healthy women before and after a 10 week graded exercise program of jogging. Pretraining TEF was a linear function of VO2max. Following exercise training, the women showed a significant increase (20%) in VO2max and loss (10.4%) of body fat; body weight did not change. Fat loss was directly related to changes in VO2max and RMR. The women showed a wide variation of changes in RMR (-21 to +2%) and TEF (-32 to +66%) from their pretraining levels. The changes in RMR and TEF were significantly positively correlated with improvements in VO2max. Analyses using multiple regression techniques, indicated that the changes in RMR and TEF accounted for 96.2% of the total variation in the changes of VO2max. Analyses of food intake indicated that diet composition (but not caloric intake) was highly related to the changes in VO2max, RMR, TEF and body fatness. Present results support further our hypothesis, that VO2max is an important physiological index of dietary thermogenesis and fat loss of individuals of normal body weight and fatness. Possible nutritional and physiological factors that may explain the wide variation in RMR and TEF of the women are discussed.

Adipose Tissue↗