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Biomedical subjects

M S Lau

Publications and source records attributed to M S Lau.

13 recordsLinked to original sources
PubMed2003

Idiopathic chronic fetomaternal haemorrhage resulting in hydrops--a case report.

INTRODUCTION: We report a case of idiopathic chronic fetomaternal haemorrhage (FMH) that developed in the late trimester. CLINICAL PRESENTATION: The patient presented with decreased fetal movement at 38 weeks gestation. Antenatal follow-up was uneventful with normal serial ultrasound performed at 22 and 35 weeks. Prior to delivery, the cardiotocography (CTG) was abnormal with decreased baseline variability and late deceleration. Emergency lower segment caesarean section was performed. Upon delivery, a hydropic neonate with a haemoglobin level of 3.9 g/dL was noted. The Kleihauer-Betke test was positive, confirming FMH. OUTCOME: The neonate later developed intraventricular haemorrhage (IVH) and spastic cerebral palsy on follow-up. DISCUSSION: It is possible for FMH to occur late at the third trimester leading to detrimental effect. The fact that FMH can occur without antecedent risk factors underscores the importance of further research, and a high index of suspicion.

Adult↗
PubMed1999

Plasma insulin, growth hormone, cortisol, and central obesity among young Chinese type 2 diabetic patients.

OBJECTIVE: To examine the relationships between central obesity, insulin resistance index, plasma insulin, growth hormone (GH), and cortisol concentrations in 90 young Chinese type 2 diabetic patients (aged 33+/-5 years) and 104 age- and sex-matched control subjects (aged 32+/-9 years). RESEARCH DESIGN AND METHODS: Young Chinese diabetic patients (aged <40 years) were recruited from the Prince of Wales Hospital. Blood pressure, height, weight, and waist and hip circumferences were determined. Venous blood was sampled for measurements of fasting plasma glucose, HbA1c, lipids, creatinine, insulin, GH, and cortisol. A 24-h urine was assayed for urinary albumin excretion (UAE). General and central obesity was represented by BMI and waist circumference, respectively. Insulin resistance index was estimated as a product of fasting plasma insulin and glucose concentrations. RESULTS: Compared with control subjects, diabetic patients were more obese, hyperglycemic, and had worse lipid profile, higher blood pressures, UAE, insulin resistance index, plasma insulin, and cortisol concentrations (all P < 0.001) but lower GH concentrations (P < 0.05). When analyzed as a whole group (n = 194), increasing quartiles of waist circumference were associated with increasing trends of insulin resistance index, plasma insulin, and cortisol concentrations (all P < 0.01) but a decreasing trend of plasma GH concentration (P < 0.05). Using stepwise multiple regression analysis, waist circumference was only associated with sex variable (being higher in men) in the control subjects. In the diabetic group, 51% of waist circumference was independently related to male sex and increased plasma insulin and cortisol concentrations as well as reduced plasma GH levels. CONCLUSIONS: In young Chinese type 2 diabetic patients, hyperinsulinemia, hypercortisolemia, and reduced plasma GH levels were closely associated with central obesity. Based on these findings, we postulate that maladaptive hormonal responses to rapid changes in lifestyle may have led to obesity and type 2 diabetes in these young patients. Alternatively, lifestyle-related obesity may have given rise to these hormonal changes. More studies are required to delineate the nature of these relationships.

Adolescent↗
PubMed1998

Antibodies to glutamic acid decarboxylase in young Chinese diabetic patients.

Antibodies to glutamic acid decarboxylase (GAD) are a useful autoimmune marker for type 1 diabetes mellitus in Caucasians. We examined antibodies to GAD and their relationships with clinical features and pancreatic beta cell function in 140 young Chinese diabetic patients. Over an 18-month period beginning in 1995, 140 young Chinese diabetic subjects with age of onset of disease < or = 35 years and age < 40 years were recruited consecutively, irrespective of their modes of presentation. Clinical features, antibodies to GAD and pancreatic beta cell function (using a glucagon stimulation test) were examined. Increased levels of antibodies to GAD (> 18 units) were detected in 12.1% (n = 17) of these subjects. Forty-three (31%) patients had a classical type 1 presentation and 65 (46%) patients were insulin-deficient based on post-glucagon plasma C-peptide levels. Patients who were insulin-deficient and had a type 1 presentation had the highest prevalence of antibodies to GAD (29.0%) compared with patients who had a type 2 presentation and were non-insulin deficient (6.4%, P = 0.003). Patients who had antibodies to GAD had lower body mass index and waist-hip ratio, earlier onset of disease, lower blood pressure, plasma triglyceride and C-peptide, and higher concentrations of plasma high-density lipoprotein cholesterol and glycated haemoglobin, and were more likely to require drug treatment, compared with those without antibodies to GAD. In conclusion, there was a low prevalence of antibodies to GAD in Chinese young diabetic patients although such antibodies remained a relatively specific marker for insulin deficiency and acute presentation. Causes other than autoimmunity should be sought to explain the high prevalence of insulin deficiency in these young Chinese patients.

Antibodies↗
PubMed1996

The short insulin tolerance test: feasibility study using venous sampling.

The short insulin tolerance test (ITT) is both a simple and valid method of quantifying insulin sensitivity although arterialization of samples and the risk of hypoglycaemia remain as potential difficulties. We examined the safety and reproducibility of using venous sampling with insulin doses of 0.1 U kg-1 and 0.05 U kg-1 in healthy subjects. Whole blood glucose concentrations were measured contemporaneously and the rate of plasma glucose decline (mmol l-1 min-1) for each test was estimated from unlogged venous plasma glucose concentrations measured at 1 min intervals. The mean rates of plasma glucose decline for the 0.1 U kg-1 and 0.05 U kg-1 insulin doses were 0.26 mmol l-1 min-1 (n = 11, range = 0.17-0.41, intrasubject coefficient of variation (CV) = 9.4%) and 0.25 mmol l-1 min-1 (n = 6, range 0.19-0.46, intrasubject CV = 15.9%), respectively. Reversal of significant hypoglycaemia was necessary in one subject before 15 min post-insulin. We found that: (1) venous sampling provides a reproducible measure of glucose uptake after insulin, (2) contemporaneous bedside glucose sampling identifies those at risk of significant hypoglycaemia during the ITT, and (3) the 0.1 U kg-1 dose response is more reproducible and no less safe than the half dose response. We conclude that the current ITT protocol would be made safer and simpler with the above modifications although further studies comparing venous with arterialized sampling are needed.

Adult↗
PubMed1995

The effect of transcutaneous electrical nerve stimulation (TENS) on autonomic cardiovascular reflexes.

Transcutaneous electrical nerve stimulation (TENS) has been shown to have an anti-ischaemic effect in patients with angina and peripheral vascular disease that appears to be additional to any analgesic action. The mechanism for this anti-ischaemic effect is not known but it is possible that TENS interferes with the autonomic responses to ischaemia. To determine if TENS has any direct action on autonomic reflexes we have assessed the effect of high frequency TENS on a variety of standard tests of autonomic cardiovascular reflexes in 10 normal subjects. Tests were done on four consecutive days at the same time and TENS therapy or placebo was randomly allocated on 2 days each. Results of the tests were assessed by one person 'blinded' to the randomization order. These showed that TENS was associated with a significant reduction in the rise of the diastolic blood pressure (21.8 +/- 2.3 v. 17.6 +/- 17 mmHg; p < 0.05) during isometric exercise, using sustained Handgrip. There was no significant effect discernible on the changes of heart rate and blood pressure during the Valsalva manoeuvre, cold face stimulus or head-up tilt. Transcutaneous electrical nerve stimulation appears, therefore, to have a mild inhibitory action on those reflexes mediated predominantly by the sympathetic nervous system and this is more apparent when the stimulation may be greater, as during isometric exercise.

Adult↗
PubMed1993

Isotype-specific regulation of human lymphocyte production of immunoglobulins by sustained exposure to vasoactive intestinal peptide.

Exposure of lymphocytes to nanomolar to micromolar concentrations of vasoactive intestinal peptide (VIP) for 1 to 3 days only modestly suppressed or enhanced the production of IgA and IgM, but not IgG. The effects of twice daily additions of 10(-12) to 10(-7) mol/L VIP for up to 18 days on pokeweed mitogen-stimulated peripheral blood mononuclear cells (PBMCs) from normal human subjects was examined by quantifying the production of IgG, IgM, and IgA. The maximum suppression of IgG by 10(-9) mol/L VIP was 79% +/- 33% (mean +/- SD) (range, 41% to 97%; p < 0.015) on day 9 and 84% +/- 1% (range, 74% to 96%; p < 0.0001) on day 14 and was significant at 6 x 10(-10) to 4 x 10(-9) mol/L VIP. Suppression of IgM production by 10(-9) mol/L VIP was significant and was observed first on day 5 and persisted through day 14. VIP did not alter IgA production or affect the proliferation or viability of PBMCs. The production of IgE by interleukin-4 stimulated PBMCs was enhanced consistently in two subjects but not in two other subjects. The duration of exposure to nanomolar concentrations of VIP is thus a critical determinant of its immunoregulatory effect, as manifested by late suppression of production of IgG and IgM and concurrent enhancement of production of IgE in some subjects.

B-Lymphocyte Subsets↗
PubMed1993

Serious complications associated with Dettol poisoning.

Dettol is involved in 10% of self-poisoning-related hospital admissions in Hong Kong. Although serious poisonings and even deaths after ingesting this common household disinfectant have been reported, the frequency with which these complications may occur is not known. In a retrospective study of 67 cases of Dettol poisoning, we found that serious complications were relatively common (8%) and these included aspiration of Dettol with gastric contents resulting in pneumonia, cardiopulmonary arrest, bronchospasm, adult respiratory distress syndrome, and severe laryngeal oedema with upper airways obstruction. It is particularly important that the airways are adequately protected before the patient is lavaged following Dettol poisoning, and the immediate recognition of any upper airway obstruction requiring intubation will then be life-saving.

Adolescent↗
PubMed1990

The role of alternating air and Silicore overlays in preventing decubitus ulcers.

Patients with chronic neurological diseases who were at high risk of decubitus ulcers were randomly assigned to alternating air on silicore mattress overlays for a period of 3 months. Of 148 subjects who completed the trial, more than 50% in each group developed one or more ulcers. No statistically significant differences between groups were found in the incidence, severity, healing duration or the location of the ulcers; with the exception of a significant difference (p less than 0.001) in the categorical location of the trochanters.

Adolescent↗
PubMed1990

Eosinophilic pleural effusions.

We present 2 cases of eosinophilic pleural effusion (EPE) seen recently at Straub Hospital. One occurred in a patient with pneumococcal empyema; the 2nd patient had 2 episodes of EPE secondary to malignant histiocytic lymphoma. Eosinophilic pleural effusion (EPE) is defined as having eosinophils exceeding 10% of the pleural fluid WBC differential. EPE is usually exudative, typically accounting for 1% to 8% of all pleural effusions. Up to 30% to 35% of EPE are idiopathic, while other frequent causes include air in the pleural space (30%), and pulmonary infections (10%). Collagen vascular diseases, tuberculosis and malignancies are common causes of EPE. Although spontaneous resolution and a favorable prognosis predominates in this entity, prudent clinical follow-up is advised. Since the first documented case of eosinophilic pleural effusion in 1984 by Harmsen, clinicians have attempted to determine its significance. This condition is defined as pleural effusion with greater than 10% of the WBC differential eosinophils. We saw 2 cases of EPE at Straub Hospital during 1988.

Eosinophilia↗
PubMedDate not supplied

Costs and acceptability of two special overlays for the prevention of pressure sores.

In a randomized clinical trial, 187 adult patients with chronic neurologic conditions who were at a high risk of developing pressure sores were assigned for 3 months to either an alternating air (AA) mattress overlay or a silicore (S) mattress overlay. Costs associated with each overlay were calculated and compared by adding depreciation and yearly expenses related to maintenance, operation, and repair for 148 patients who completed the trial. Acceptability was measured by questionnaires and interviews involving 45 of the patients' primary nurses and a sample of 40 patients (20 from each overlay group). The annual cost of the AA overlay was 54% more than that of the S overlay. Although most nurses (more than 74%) believed that both overlays helped prevent pressure sores and deter their progression, many (more than 56%) would not recommend either type to other facilities or to patients at home due to specific negative features. Implications for manufacturers, investigators, clinicians, and administrators are identified.

Adolescent↗