Biomedical subjects
C Gray
Publications and source records attributed to C Gray.
UK family practice is fighting for its future.
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Metabolic effects of radiation induced rat insulinoma at pancreatic, hepatic and subscapular transplantation sites.
Metabolic effects of 3 different sites of transplantation of cultured tumour cells from a radiation induced insulinoma (28 X 10(6) viable cells per rat) were examined in 15-18 weeks old male NEDH rats. Subscapular implantation consistently produced a highly vascularised encapsulated tumour associated with hyperinsulinaemia, hyperphagia and hypoglycaemia by 21 days, which progressed to fatal neuroglycopaenic coma at 37 +/- 3 days (mean +/- SEM). Implantation of tumour cells into the hepatic portal vein resulted in a multilobular hepatic tumour in two out of nine rats, with hyperinsulinaemia and fatal hypoglycaemia by 49-54 days. Irregularities of glucose homeostasis were observed in a further three rats by 62 days. Intrapancreatic implantation consistently produced a similar tumour to that observed at the subscapular site. Implantation into the pancreas produced the most rapid onset of hyperinsulinaemia, hyperphagia and hypoglycaemia, with survival for only 28 +/- 3 days. The results demonstrate an important effect of transplantation site on the function and metabolic consequences of the NEDH rat insulinoma.
Expression of low molecular weight cytokeratins in the neoplastic vocal cord.
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Aberrent expression of low molecular weight cytokeratins in primary and secondary squamous carcinoma of the head and neck.
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Immunohistological demonstration of factors XIIIa and XIIIs in reactive and neoplastic fibroblastic and fibro-histiocytic lesions.
Factor XIII sub-units a and s (XIIIa and XIIIb) have been localized previously in fibroblasts of the liver and in other tissues. An immunoperoxidase technique was used to localize these factors in benign and malignant fibroblastic and fibro-histiocytic lesions. Positive staining was present in cells in almost all of the benign and fibro-histiocytic lesions but was reduced in the malignant group. However, the pattern of staining was not sufficiently consistent to justify the use of the factors XIII as diagnostic markers in soft tissue neoplasia.
Animal rights versus university research.
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Characterisation of monoclonal antibodies to adrenocorticotrophin.
We have produced 8 monoclonal antibodies to adrenocorticotrophin (ACTH) derived from immunisation with ACTH (1-24) conjugated to bovine serum albumin or ACTH (1-39) linked to chicken immunoglobulin by a novel method. Antibody specificity was assessed by studying the binding of purified human ACTH, synthetic ACTH (1-24), fragments of ACTH and peptides from the ACTH precursor molecule which have sequence homology. A wide range of specificities was demonstrated. Thus antibody 3H9 recognises the extreme N-terminal sequence (ACTH 4-10), antibody 1A12 is specific for residues 10-18 including alpha MSH, antibody 1D1 is specific for the mid N-terminal sequence but not alpha MSH, and antibody 2A3 is specific for the C-terminal portion (ACTH 18-39). These monoclonal antibodies can be easily purified and labelled and their defined specificities make it possible to select antibody combinations which provide the basis for 2-site immunometric assays for ACTH.
Hong Kong physicians prepare for the future.
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Hong Kong: highrise hospitals and powdered rhino horn.
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Doctors and health insurance: the British experience.
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Salmonella infection in hairy cell leukemia: report of a case.
A patient with hairy cell leukemia who developed mediastinal mass and fever is described. A CT-guided aspiration of the mass yielded Salmonella tiphymurium. Granulocyte response to infection was intact and could explain the favorable course of this unusual Salmonella infection. Although several reports deal with salmonellosis as a complication of immunodeficiency states, this type of infection is of rare occurrence in hairy cell leukemia.
Monoclonal antibodies to testosterone: the effect of immunogen structure on specificity.
A 15 beta-thioalkyl derivative of testosterone conjugated to bovine serum albumin (BSA) was synthesised and used to produce monoclonal antibodies. These antibodies were evaluated using 15 beta-(2-carboxyphenylthio)-testosterone [125I]histamine as radioligand. Out of 1368 hybrids, 5 secreted anti-testosterone antibodies. These were compared with monoclonal antibodies derived from immunisation with testosterone-3-carboxymethyloxime-BSA. The first group of monoclonal antibodies all showed very low cross-reactivity with 5 alpha-dihydrotestosterone (less than 2.8%) indicating that this site of linkage is a good choice for discriminating between differences at the 4-5 position in the A-ring on the testosterone molecule. However they generally showed much higher cross-reactivity with progesterone and androstenedione than monoclonal antibodies raised to the 3-linked immunogen. Nevertheless within each fusion there were monoclonal antibodies with markedly different specificities. None of these antibodies could be considered suitable for use in a testosterone immunoassay, but it does suggest that an antibody with an improved specificity profile could be found using the monoclonal antibody approach.
Multiple hormone secretion by a human pancreatic glucagonoma in culture.
A patient presenting clinically with the glucagonoma syndrome had high plasma glucagon levels (1920 ng/l) and at laparotomy, a pancreatic islet cell tumour was removed. The tumour was dispersed and placed in culture where it remained viable for 63 days. The tumour cells secreted immunoreactive (IR) glucagon at levels up to 2400 ng/l as detected by a C-terminal glucagon specific antibody and 85 400 ngequiv./l as measured by an N-terminal glucagon specific antibody. The difference between these two levels was attributed to the presence of different molecular forms of glucagon measured with the N-terminal specific antibody. IR insulin (up to 302 mU/l) and IR somatostatin (up to 2500 ng/l) were also detected. There was no direct or inverse correlation between different hormone levels. Small but significant levels of N-terminal and C-terminal vasoactive intestinal peptide (VIP) were detected in some cultures but there was no evidence of gastrin or ACTH. Glucagon and somatostatin secretion persisted for the duration of the culture (63 days) but insulin concentrations declined. Incubation of cultures with somatostatin (1 ng/ml) caused a 75% decrease in glucagon levels, while insulin (1000 mU/l) produced a 70% inhibition of somatostatin.
Malignant epithelioid schwannoma of superficial soft tissue? A case report with immunohistology and electron microscopy.
Malignant epithelioid schwannoma is a well-defined entity. However epithelioid tumours arising other than in a nerve trunk, in a benign nerve sheath tumour or in neurofibromatosis are problematical. We describe a case of a nodular tumour of the cheek which recurred twice without metastasis. Light microscopy showed an amelanotic epithelioid tumour. Immunohistology showed positive staining for vimentin and S100 protein and electron microscopy showed distinctive appearances suggestive of schwannoma. We discuss the differential diagnosis of the tumour, compare it with reported tumours resembling both melanoma and schwannoma and conclude that this may be a further example of the distinctive tumour reported as "malignant epithelioid schwannoma of superficial soft tissues'.
Heal the children: just one approach.
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