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Biomedical subjects

W K Ng

Publications and source records attributed to W K Ng.

At least 55 records · Page 3Linked to original sources
PubMed1994

Different guises of plasmacytoma--from skin to bone.

A case is reported of a patient with plasmacytoma which assumed different clinicopathological features over seven years. The tumour first presented as a subcutaneous mass which was misdiagnosed as anaplastic carcinoma. Complete response to radiotherapy ensued but recurrence took the form of an intracerebral tumour. Further complete response to "palliative" corticosteroids was followed by osseous lesions three years later, when the diagnosis of plasmacytoma was confirmed. This report illustrates the highly variable clinicopathological presentations of plasmacytoma, including the rare primary cutaneous manifestation.

Bone Neoplasms↗
PubMed1990

Neonatal hypothyroidism: comparison of radioisotope and ultrasound imaging in 54 cases.

Fifty-four neonates with congenital hypothyroidism identified by the North East and North West Thames Regional hypothyroid screening programme between January 1985 and December 1987 were investigated with radioisotope (Tc99m) and ultrasound scans of the thyroid before treatment with 1-thyroxine was commenced. Compared with the radioisotope scans, ultrasound identified normally sited thyroid tissue in only 7 out of 10 cases, and ectopic thyroid tissue in only 5 out of 26 cases. Three out of 18 cases with no isotope uptake in the neck appeared to have normally sited tissue on ultrasound scan. We conclude that in our hands ultrasound of the neck is of only limited value in the assessment of young infants with congenital hypothyroidism.

Congenital Hypothyroidism↗
PubMed1990

5 alpha-reductase deficiency without hypospadias.

A boy aged 4 with penoscrotal hypospadias and his brother aged 12 with micropenis had typical changes of homozygous 5 alpha-reductase deficiency. After three injections of chorionic gonadotrophin there was a trivial rise in plasma dihydrotestosterone with a normal increase in plasma testosterone. Urine steroid chromatography showed abnormally high 5 beta: 5 alpha ratios and 5 alpha-reductase activity was appreciably reduced in genital skin fibroblasts. The results indicate that 5 alpha-reductase deficiency is not invariably associated with genital ambiguity.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed1990

Relationship between maternal antithrombin III and protein C/protein S levels before, during and after delivery.

The relationship between plasma levels of protein C, protein S and antithrombin III was examined in a group of normal pregnant Chinese women with singleton pregnancies to study the changes in the anticoagulant system in relation to pregnancy, labour and the puerperium. A significant correlation was found between protein C and antithrombin III both before labour and postpartum, and the ratio was close to unity. When the two groups are combined, a highly significant correlation was found (r = 0.758; p less than 0.001). The correlation is not observed at delivery when the ratio becomes very variable and in general greater than unity. The correlation between protein S and antithrombin III was 0.592 before labour and -0.532 at delivery, but both failed to reach statistical significance because of the small numbers. When postpartum concentration of protein C, protein S and antithrombin III is related to interval between sampling and delivery, significant correlation was found only with protein S. The results of this study suggest that the plasma level of protein C and probably protein S is correlated with that of antithrombin III during pregnancy, labour and the puerperium.

Antithrombin III↗
PubMed1989

Early post-natal growth of large-for-dates babies of non-diabetic mothers is influenced by maternal glucose metabolism.

Growth of weight, length, head circumference and skinfold thickness (subscapular and triceps) from birth to 6 months in 53 large-for-dates (LFD) Chinese babies weighing greater than 4.0 kg at term and born to non-diabetic mothers was investigated and correlated with biochemical indices of maternal glucose tolerance at birth: glycosylated haemoglobin (HbA1), serum corrected fructosamine and the area under the oral glucose (50 g) tolerance (OGTT) curve. Growth in all physical dimensions, especially weight, showed a downward shift towards a reference mean. These changes in relative size were caused by slower growth velocities. None of the mothers had abnormally high concentrations of HbA1 or fructosamine nor an abnormal OGTT. However, weight velocities did show small but significant correlations with fructosamine (r = -0.42), and OGTT area units (r = 0.39) but not with HbA1. For some macrosomic babies born to apparently normal mothers, birth is seen to interrupt a process operating in prenatal life that accelerates growth. Covert abnormalities of maternal glucose homeostasis could explain this. Abnormal glucose tolerance during pregnancy might therefore be viewed as a continuum extending from (i) its maximum expression, the frankly diabetic state, through (ii) gestational diabetes to (iii) the mother who has no biochemically evident abnormality of glucose homeostasis but who has sufficient alteration to modify fetal growth. Post-natal growth of LFD babies is additional information which, when taken along with other markers of maternal glucose tolerance, might help to identify the mother at later perinatal risk.

Birth Weight↗
PubMed1989

Radionuclide contents in building materials used in Hong Kong.

The radionuclide contents of conventional natural raw building materials, coal ash and slag, and finished building products have been determined using gamma-ray spectrometry. Results of brick measurements in their original geometry and in crushed form are compared. The radioactive concentrations in cement and sand, mostly imported from China, are among the lowest measured. However, due to the high radioactivity of aggregates, composed of granite mainly extracted locally, the mean Ra equivalent activity of concrete is high compared with that in some countries. The radioactivity levels of coal ash and slag in Hong Kong are about the average values in other countries. The incorporation of coal ash and slag in ordinary concrete does not alter the radioactivity significantly.

Construction Materials↗
PubMed1989

Ectopic thyroid: residual function after withdrawal of treatment in infancy and later childhood.

Plasma thyroxine (T4) and thyrotrophin (TSH) were estimated in 34 children identified by neonatal hypothyroid screening and subsequently found to have ectopic thyroid tissue on isotope scan. Before treatment plasma T4 ranged from 8-143 nmol/l and TSH from 39-1,230 mU/l. After one week off treatment during their second year, repeat T4 in 26 of these cases showed a significant correlation with the pre-treatment values (r = 0.57). However, only 3 of the 5 children with pre-treatment T4 levels over 100 nmol/l at diagnosis had normal T4 values when retested. Similarly, when 10 children with pre-treatment T4 values over 65 nmol/l were retested off treatment at the ages of 5.8-8.2 years, only 4 had plasma T4 levels in the normal range. These results illustrate the wide range of thyroid function which can occur in children with ectopic thyroid tissue and indicate that some continue to have near-normal thyroid function for considerable periods. However, pre-treatment T4 results do not allow accurate identification of these latter cases.

Child↗
PubMed1984

The role of Chinese traditional medical practice as a form of health care in Singapore--III. Conditions, illness behaviour and medical preferences of patients of institutional clinics.

Both the modern scientific and the Chinese traditional forms of health care are within easy geographical, economical and quantitative accessibility to the people in Singapore. The fourth component of accessibility, socio-cultural component encompasses the social milieu surrounding the individual, and the values and beliefs attached to diseases and health care services. This paper reveals the findings of a survey of a quota sample of patients in institutional clinics providing Chinese traditional medical consultations. The survey aimed to look at the types of illness conditions presented in these clinics, the multi-usage of both modern and traditional health care by these patients, and the inter-relationship between illness behaviour and differential preferences of treatment methods for various disease conditions.

Adolescent↗
PubMed1984

The toxic effects of triorganotin(IV) compounds on the culicine mosquito, Aedes aegypti (L).

The structure-activity relationships of 25 triorganotin(IV) compounds were studied using the 4th instar A. aegypti larvae of the susceptible Liverpool Red-eye strain. The LC50 values of these compounds were compared with those of Malathion, DDT and Temephos. Maximal activities were obtained with tritolyltin chloride and its complexes with triphenyl-phosphine oxide and pyridine N-oxide, dimethyloctyltin- and diethyloctyltin acetates and tributyltin sucrose phthalate. A limited number of the triorganotin compounds was also tested with observed high activity against the 4th instar larvae of a local DDT-tolerant strain and against the 2nd instar larvae and adults of the susceptible strain. Delayed effect studies with both 2nd and 4th instar larvae showed high post-treatment mortality for the latter and, among the range of active compounds, the methyl- and aryltin compounds, in particular, were also found to exhibit high residual activities (100% kill) in laboratory tests conducted up to 10 weeks.

Aedes↗