PubMed Health⌕ Search

Biomedical subjects

S K Yap

Publications and source records attributed to S K Yap.

7 recordsLinked to original sources
PubMed1996

Spasmus nutans.

Spasmus nutans is classically described as a triad of nystagmus, head nodding and torticollis. It occurs in children, beginning in infancy and usually disappears in childhood. It is uncommon but its prompt recognition by ophthalmologists, paediatricians and neurologists can provide reassurance to the family of its benign nature. It is important to distinguish it from more serious conditions like gliomas which may present with signs mimicking spasmus nutans. We describe a case of a 3-year-old boy with acquired horizontal pendular nystagmus associated with head nodding and torticollis. The diagnosis of spasmus nutans, its implications and its management are discussed.

Child, Preschool↗
PubMed1992

Post-menopausal smear patterns--a review of vaginal smears in 480 women.

Cytohormonal evaluation was done on the vaginal smears of 480 normal, asymptomatic, post-menopausal women whose ages ranged from 36 to 74 years. About 50% showed atrophic smears consistent with total oestrogen lack. 41% had mild to moderately proliferative smears compatible with sub-optimal oestrogen stimulus. 9% showed a highly proliferative pattern typical of unopposed oestrogen effect and in this group two women had atypical endometrial cells in their smears, which subsequently were found to come from an atypical endometrial hyperplasia and an endometrial adenocarcinoma-in-situ. The clinical relevance of cytohormonal studies in post-menopausal women is briefly discussed.

Adult↗
PubMed1976

Development of a stable sublingual nitroglycerin tablet II: formulation and evaluation of tablets containing povidone.

Stable and pharmaceutically elegant sublingual nitroglycerin tablets were formulated using povidone to retard volatilization of the drug. Formulation and processing variables were investigated to produce an acceptable product. A blend of two grades of povidone, of different degrees of cross-linkage and water solubility, provided stable tablets which exhibited rapid disintegration. Directly compressed sublingual tablets made in this study retained over 80% of the initial nitroglycerin when exposed to the atmosphere at room temperature for 2 months. The direct compression tablets are of good appearance and low friability, and the formulation is readily compressed without problems. An interesting relationship among the hardness, disintegration time, and compaction pressure is described.

Drug Compounding↗
PubMed1975

Factors affecting the kinetic assay of nitroglycerin in dosage forms.

Parameters affecting the spectrophotometric kinetic assay for nitroglycerin are described. It is shown that the assay is highly specific; results are not significantly affected by many of the tablet diluents found in commercially-available nitroglycerin tablets. Further, the assay is insensitive to glycerol, nitrate, nitrite and glyceryl dinitrates. This simple, precise and specific nitroglycerin assay is well suited for routine analysis of the drug in commercial tablets and parenteral solutions in hospital pharmacies.

Chemistry, Pharmaceutical↗