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Biomedical subjects

S H Tan

Publications and source records attributed to S H Tan.

126 records · Page 7Linked to original sources
PubMed1979

[Enzyme histochemical study of the brain of Chthonerpeton indistinctum (Gymnophiona, Amphibia)].

In the brain of the Caecilian species Chthonerpeton indistinctum the following enzymes have been demonstrated by means of histochemical techniques: acid phosphatase, alpha-naphthylacetate esterase, acetylcholin esterase. Acid phosphatase occurs in the cytoplasm of the neurons in 4 different types of localization. Its activity in the ventral parts of the brain is markedly higher than in the dorsal ones. Of particularly high activity are: the motor neurons in the tegmentum, the nucleus mesencephali trigemini, individual large neurons in the marginal zone of the grey matter of the telencephalon, which seems to be a special character of the Caecilians among the Amphibia. The ependyma exhibits local differences in respect of acid phosphatase activity. alpha-Naphthylacetate esterase marks in particular the secretory neurons of the hypothalamus, the large perikarya of the nucleus mesencephali trigemini and the motor neurons of the tegmentum. In the telencephalon the alpha-naphthylacetate esterase activity corresponds to that of acid phosphatase. Acetylcholin esterase marks--with certain restrictions--cholinergic neurons. These predominate in Chthonerpeton in the caudal parts of the brain. In the telencephalon amygdala, septal area striatum and the mitral cells are of comparatively high activity. The neurosecretory neurons of the hypothalamus are particularly rich in this enzyme. As an anurans the cholinergic fasciculus retroflexus as asymmetric. The tectum opticum is of secondary simplicity and does not exhibit a clearly recognizable stratification.

Acetylcholinesterase↗
PubMed1977

Pathogenicity of nonpigmented cultures of Chromobacterium violaceum.

Nonpigmented cultures of Chromobacterium violaceum have been found to be similar to pigmented cultures in their virulence for mice and the pathology of their infections. Clinicians and microbiologists should be prepared to consider nonpigmented C. violaceum in their differential diagnoses of infections caused by gram-negative bacteria. The laboratorian who is not aware of this possibility is likely to erroneously identify nonpigmented strains of C. violaceum as members of closely associated genera, particularly Aeromonas. It is known that violet pigmentation is not an essential feature or an exclusive character of the genus Chromobacterium. This study has also shown that pigmentation of C. violaceum is not related to its pathogenicity or to the pathology of its infections.

Aeromonas↗
PubMed1976

Histological and histochemical observations on the neurosecretory cells in the diencephalon of Chthonerpeton indistinctum and Ichthyophis paucisulcus (Gymnophiona, Amphibia).

In the diencephalon of two species of Gymnophiona (Amphibia) two neurosecretory nuclei were examined with histological (Alcian Blue, Aldehyde Fuchsin, Brookes Trichrome stain) and enzyme histochemical techniques (acid phosphatase, alpha-naphthyl acetate esterase, acetylcholinesterase (AChE)). In the preoptic nucleus two categories of secretory neurons were distinguished: large and medium sized neurons. The perikarya of both cell types contain very little neurosecretory material. The Alcian Blue method stained the medium sized neurons faintly but selectively. The tractus praeopticohypophyseus is marked by the presence of Herring bodies, which, however, are relatively scarce. The neurohypophysis, in contrast, contains large amounts of neurosecretory material. Both cell types of the preoptic nucleus are characterized by their very strong AChE and alpha-naphthylacetate esterase activity. The AChE also marks the tractus praeoptico-hypophyseus. In the large neurons acid phosphatase is present around the nucleus; in the medium sized neurons this enzyme is concentrated close to the origin of the axon. In the dorso-caudal hypothalamus a small group of neurons is stained with Alcian-Blue. These neurons, which also contain AChE, are located immediately under the ependyma which seems to be specialized in this region.

Acetylcholinesterase↗
PubMedDate not supplied

Monitoring of diabetes in children.

There is increasing evidence to show that a high degree of metabolic control in diabetes mellitus delays and reduces the severity and incidence of the microvascular complications of diabetes. The goals of appropriate therapy for diabetes should hence include an all-out effort to achieve as near normal metabolism as possible but it should be individualized accordingly. In actual practice it is difficult to achieve "good" control especially in diabetic children without attendant hypoglycaemia and its sequelae. Diabetic control is difficult to define in clinical terms, and the maintenance of metabolic control in diabetes involves a complex interaction of pathological, physiological, psychological, familial, social and environmental variables. The aims in insulin-dependent diabetic children is to ensure optimal emotional and physical health of the child or adolescent. The various modalities available for monitoring or assessment of diabetic control shall be discussed.

Adolescent↗
PubMedDate not supplied

Once-daily intraperitoneal gentamicin is effective therapy for gram-negative CAPD peritonitis.

OBJECTIVE: To report our 3-year experience with the use of once-daily intraperitoneal (IP) gentamicin in the treatment of gram-negative continuous ambulatory peritoneal dialysis (CAPD) peritonitis. DESIGN: A prospective cohort study in prevalent CAPD patients. SETTING: A tertiary care institution. PATIENTS: All CAPD patients who presented with new episodes of peritonitis were studied. At presentation with peritonitis, IP vancomycin and gentamicin were administered as empirical therapy. IP gentamicin was given at a single daily dose of 40 mg/2 L in the overnight bag. The antimicrobial agents were reviewed when the culture results became available. Intraperitoneal ceftazidime was added for the treatment of pseudomonas peritonitis. MAIN OUTCOME MEASURES: Results of microbiological cultures and clinical outcomes of peritonitis were analyzed. RESULTS: Over a 36-month period, 190 episodes of peritonitis were recorded, of which 62/190 episodes (32.6%) isolated gram-negative organisms. The gram-negative organisms isolated were Escherichia coli, 15/62 episodes (24.1%); Pseudomonas aeruginosa, 12/62 episodes (19.4%); Acinetobacter spp, 12/62 episodes (19.4%); Klebsiella spp, 10/62 episodes (16.1%); and others, 13/62 episodes (21.0%). The overall treatment success rate was 66.1%. The treatment success rates were 74.0% if pseudomonas infections were excluded, 76.1% if gentamicin-resistant pathogens were excluded, and 80.5% if both pseudomonas infections and gentamicin-resistant pathogens were excluded. CONCLUSIONS: Once-daily IP gentamicin appears to be effective in the treatment of gram-negative CAPD peritonitis.

Anti-Bacterial Agents↗