Biomedical subjects
Publications and source records attributed to T Mathew.
A Sertoli cell tumour that occurred in a true hermaphrodite with a 46, XX chromosome constitution is described. Removal of the tumour was followed by an immediate fall in plasma FSH and LH concentrations. It is suggested that the tumour possessed the capacity for ectopic production of the gonadotrophins.
Formalin-fixed tissues from 37 cases of primary liver malignancies were investigated by the technique of Specific Red Cell Adherence (SRCA) for studying the presence or absence of blood group isoantigens A, B and H. These tumours comprised 15 cases of hepatocellular carcinomas, 5 hepatoblastomas, and 17 cholangiocarcinomas. Results of the SRCA were consistently negative in all hepatocellular carcinomas and hepatoblastomas. Fifteen of 17 (88%) cholangiocarcinomas gave a positive SRCA, but no correlation could be obtained between the intensity of the reaction and their histological grading or metastatic potential. Reasons are given for the negative reactions in hepatocellular carcinomas and hepatoblastomas, an possible explanations are offered for the high rate of positivity in cholangiocarcinomas. It is concluded that the inherent properties of these 3 tumours limit the application of the SRCA procedure as a potential gauge of prognosis.
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We studied a unique case of osteosarcoma of the testis. The tumor either originated from indifferent mesenchymal cells, or it represents a one-sided monomorphic development of a teratoma.
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Hematoxylin and eosin-stained sections representing ten cases of hepatocellular carcinoma showed many tumor cells with ground-glass cytoplasm identical to that found in hepatocytes containing hepatitis B surface antigen (HBsAg). However, the aldehyde fuchsin stain was negative, as were the were the immunoperoxisidase stains for HBsAg and core antigen (HBcAg). Electron microscopically, the ground-glass appearance corresponded to the presence of non-membrane-bound amorphous or fibrillar inclusions. Immunohistochemically, the ground-glass material reacted with antiserum to human fibrinogen, suggesting synthesis of this protein by the carcinoma cells. Although the ground-glass appearance in hepatocellular carcinomas may sometimes be associated with HBsAg, special stains or technics are necessary to confirm its presence.
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Albino rats were each treated with a single intraperitoneal injection of dimethylformamide (DMF) or dimethysulfoxide (DMSO). The doses of DMF administered were 0.6, 0.9, and 1.2 ml. per kg. and those of DMSO were 1.2, 2.4, 3.6, and 4.8 ml. per kg. The animals were sacrificed at 24, 48, 72, and 120 hours following administration of each dose. The liver was investigated in all cases. Treatment with DMF at 0.6 ml. per kg. indicated some histologic lesions of the liver which became well defined at 0.9 and 1.2 ml. per kg. causing severe central phlebitis with centrilobular coagulative necrosis of the cells associated with a heavy inflammatory infiltrate. Maximal liver lesions occurred at 48 hours and started to regress after 72 hours. However, cellular atypism became a consistent finding after this inflammatory phase. DMSO-treated animals showed minimal histologic lesions of the liver at 1.2 and 2.4 ml. per kg. Higher doses caused fatty infiltration with a predominatly periportal distribution. It tended to produce its maximal effect in 12 hours which then regressed rapidly after 24 hours. The development of histologic lesions in the liver even at 0.6 ml. per kg. suggests that DMF is not a suitable solvent for aflatoxin studies, and hence the results obtained from such studies need cautious interpretation. DMSO appears to be an ideal alternative for toxicologic studies at a much higher dose level compared to DMF.
During the period between January 1975 and August 1976, 203 liver biopsies were received at the Singapore General Hospital from patients with a variety of liver diseases. A histological diagnosis of chronic hepatitis was made in 29 patients: 13 cases of Chronic Aggressive Hepatitis (C.A.H.). 10 cases Chronic Persistent Hepatitis (C.P.H.) and 6 of Chronic Lobular Hepatitis (C.L.H.). C.P.H. and C.L.H. were found mainly in the third and fourth decades. C.A.H. was more common in the fifth to seventh decades and occurred principally in females. Hepatitis B antigenaemia was detected in 48.3% of these cases using the immunoelectroosmophoresis (EOP) technique and showed an even scatter in all histological sub-types. Using the reverse passive haemagglutination (rPHA) method for detection by HBs antigen and the radioelectrocomplexing (REC) method for anti-HBs, an immune sub-group (HBs Ag+/anti-HBs+) was identified in greater proportions in C.A.H. and C.P.H. compared to normal controls. This was interpreted to mean that these patients suffered from a primary immunodeficiency characterized by failure of production of high avidity anti-HBs with resulting failure to clear HBsAg leading to perpetuation of liver damage due to circulating immune complexes. It is also suggested that patients with C.P.H. belonging to this immune sub-group may progress to C.A.H. with its more ominous prognosis.
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The effects of a number of growth substances on the absorption and translocation of iron were studied in bean plants. Gibberellic acid application to the trifoliate leaf enhanced absorption of Fe applied to the primary leaf. 2-Chloroethyltrimethylammonium chloride increased absorption by the primary leaf while 6-furfurylaminopurine (kinetin) increased the transport of Fe from the primary leaf to other parts. When the roots were pretreated with gibberellic acid, the absorption of Fe by the primary leaf and subsequent transport to the trifoliate leaves were increased. Triiodobenzoic acid reduced the absorption and transport of Fe.Absorption of Fe by roots and transport to other parts were increased by pretreatment of the roots with gibberellic acid, 2-chloroethyltrimethylammonium chloride or N,N-dimethylaminosuccinamic acid for 3 days. An increase in the transport to other parts of Fe absorbed by roots was obtained when roots were exposed to the growth substances following Fe absorption.Absorption and transport of Fe in corn plants were much less than those of Rb and phosphate. Absorption and transport of Fe were greater in plants with decorticated roots than in those with intact roots. N,N-Dimethylaminosuccinamic acid significantly promoted the transport of root-absorbed Fe to the shoots of corn plants.