Search PubMed⌕ Search

Biomedical subjects

S M Chong

Publications and source records attributed to S M Chong.

At least 37 records · Page 2Linked to original sources
PubMed1997

Splenic lymphoma with villus lymphocytes--an uncommon cause for lymphocytosis.

We describe the clinical and laboratory features of four patients who presented with mild to moderate lymphocytosis but with no peripheral lymphadenopathy. These patients in the past, would have been classified as chronic lymphocytic leukaemia (CLL). However, it is now realised that chronic lymphoproliferative disorders are very heterogeneous and the clinical and laboratory features of our patients would support a diagnosis of splenic lymphoma with villus lymphocytes (SLVL) with characteristic morphological features. SLVL usually runs a benign clinical course but symptoms related a benign clinical course but symptoms related to splenomegaly or hypersplenism may be a problem. Splenectomy is considered the treatment of choice in these patients. Two of our patients had splenectomy and the other two patients are on regular follow-up without any specific treatment. It is therefore important to recognise this uncommon condition and also to differentiate it from CLL.

Diagnosis, Differential↗
PubMed1994

An interesting case of intersex: case report.

Intersex is a rare problem. Ambiguous genitalia, a frequent presentation of intersex, is seldom due to true hermaphroditism. This case report describes the findings in such a rare case.

Adolescent↗
PubMed1991

Fetal pig pancreas--a preliminary assessment of tissue for transplantation.

Porcine fetal pancreases (PFP) obtained from 4 pregnant sows were pooled, minced into 1 mm3 fragments and studied in organ culture for up to 30 days to determine tissue viability and insulin production in vitro. After 7-9 days in culture, some of these explants were transplanted into euglycemic, N:NIH-nu(s) nude recipient mice, and studied histologically over 69 days following grafting. Using RPMI 1640 supplemented with 5% fetal calf serum as the culture medium in 90% air/10% CO2, it was found that explants were viable with insulin production detected in vitro, which was maximal at day 7 (197 +/- 18.9 mU/L, n = 11), and gradually declined thereafter. By 22 days, insulin levels were less than 60.1 +/- 28.5 mU/L (n = 6). Histology of the explants showed viable tissue with evidence of mitoses present in insulin-positive cells at day 16 in vitro. Beyond this time, tissue viability diminished. Explants transplanted into euglycemic nude mice did not undergo rejection during the observation period of 69 days. Grafts remained viable with evidence of an increase in mitotic activity in the endocrine tissue on immunoperoxidase staining. These preliminary investigations confirm that pancreatic explants from porcine fetuses can be maintained in culture for up to 16 days. Such explants, when transplanted under the kidney capsule of euglycemic, nude mice, did not undergo necrosis, but remained viable, with evidence of mitoses in the islet tissue.

Animals↗
PubMed1991

A study of the xenogeneic response in an isolated liver perfusion circuit--preliminary observations.

An isolated liver perfusion circuit was developed to study the xenogeneic reaction of human blood to porcine liver, and investigate the feasibility of using such a system for liver dialysis in fulminant hepatic failure. Three experimental groups were studied: a control group where pooled porcine blood was perfused through pig liver (n = 12), a xenogeneic group where banked human blood was perfused through porcine liver (n = 23), and a modified xenogeneic group where decomplemented human blood was perfused through porcine liver (n = 4). The following parameters of liver function were assessed: liver function tests, serum electrolytes, bile and ascites production. In addition, liver histology was assessed at the start and completion of each perfusion experiment. Control experiments established that the use of low perfusion pressures (mean inlet pressure of 29.5 +/- 7.4 mmHg), and low haematocrit of 20.5 +/- 8.9% (n = 14), enabled five hour perfusions to be consistently achieved with maintenance of normal acid base and electrolyte balance. Bile production over 5 hours was 18.8 +/- 8.0 ml in controls (n = 5) and 17.0 +/- 6.7 ml in the xenogeneic (human-pig) circuit (n = 11) (NS). Ascites production was 235.8 +/- 157.3 ml/hr in controls (n = 5) and 205 +/- 142.0 ml/hr in the xenogeneic circuit (n = 7) (NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Pathology of the 5 most common cancers in Singapore.

Cancers in Singapore are on the rise in recent years. The five most frequent cancers in Singapore are lung, stomach, liver, colo-rectum and nasopharynx in males, and breast, uterine cervix, stomach, lung and colo-rectum in females. This article briefly reviews the pathology of these common cancers with emphasis on local patterns and recent developments.

Breast Neoplasms↗
PubMed1986

Inhibition of phospholipase A2 by protein I.

The 36 kDa substrate of several tyrosine protein kinases has been shown to exist in monomeric and oligomeric (362102) forms. Partial sequence data has suggested that the oligomer, referred to as protein I, is homologous to a group of phospholipase A2 inhibitory proteins, collectively called lipocortins. In the present communication we demonstrate that protein I inhibits bovine pancreas phospholipase A2 with similar potency to that of lipocortin. Approximately 44 pmol protein I was required to produce 50% inhibition of 7.2 pmol of phospholipase A2. Inhibition of phospholipase A2 activity by calmodulin, S-100, calregulin, parvalbumin, troponin-C, or CAB-48 was not observed. These results indicate that protein I is a potent and specific inhibitor of phospholipase A2 activity, and thus shares functional homology with the lipocortin proteins. We therefore propose that this protein be named lipocortin-85.

Amino Acid Sequence↗
PubMed1986

Phosphorylation of p36 in vitro by protein kinase C.

The 36kDa subunit of protein I (p36) is a major substrate of several tyrosine protein kinases. Here we demonstrate that protein kinase C catalyzes the incorporation of 1.7 moles of phosphate per mole of protein I. Phosphorylation is absolutely dependent on the presence of both calcium and phospholipid, and is specific for serine and threonine residues. Phosphorylation of protein I by the c-AMP dependent protein kinase, phosphorylase kinase, casein kinase I, and casein kinase II was not observed. The in vivo significance of protein kinase C dependent phosphorylation of p36 is discussed.

Animals↗