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Biomedical subjects

L C Yong

Publications and source records attributed to L C Yong.

36 records · Page 2Linked to original sources
PubMed1987

Cardiovascular lesions in experimental acute and chronic renal failure in the rat.

Adult Wistar rats were subjected to partial or total nephrectomy or injected with mercuric chloride to induce a state of acute or chronic renal failure. They developed sequential pathological changes in the cardiovascular system characterized by fibrin deposition in the pericardium and fibrinoid changes in many systemic arteries and arterioles. Focal myocardial necrosis and interstitial fibrosis were a feature of long term chronic renal failure. Increased vascular permeability was evident in the pericardium of rats with chronic renal failure especially when autologous blood was also injected into the pericardial sac of previously nephrectomized rats.

Acute Kidney Injury↗
PubMed1986

Pathological changes in streptozotocin induced diabetes mellitus in the rat.

The structural changes in kidneys of diabetic rats induced by streptozotocin were compared with those of age-matched control animals. Degenerative changes were found in the distal tubules of diabetic rats as early as 2 weeks following the onset of diabetes and by one month the entire distal tubule was severely affected. Fibrinoid lesions were also found in diabetic rats after 4 weeks of the disease and became more frequent subsequently. IgG, albumin but not C3 were also found in the glomerular basement membrane of diabetic rats. Diabetic glomerulosclerosis was present only after several weeks, affected glomeruli showed diffuse mesangial sclerosis and only occasionally nodular sclerosis. Diabetic animals developed renal cortical adenomas and mesenchymal tumours after several months.

Animals↗
PubMed1984

Pathological changes in the heterologous phase of antibasement membrane antibody mediated disease in the rat.

The immunological and structural changes during the heterologous phase of experimental antibasement membrane antibody mediated disease was sequentially studied in the rat following single i.v. injections of rabbit antibodies to basement membrane antigens prepared from kidney, lung and salivary gland tissues. Although each of the anti-bodies bound strongly to GBM, structural changes were initially subtle accompanied by proteinuria and hematuria. More severe structural changes related to dose and duration of the disease did not appear for several weeks.

Animals↗
PubMed1984

A model of bile duct hyperplasia in the rat induced by diethylnitrosamine and selective cytotoxicity.

Adult Wistar rats were subjected to a chemical carcinogenesis regimen involving initiation with diethylnitrosamine (DEN) and cytotoxic selection of initiated cells following partial hepatectomy. The livers of treated rats exhibited sequential changes of vacuolar degeneration and hepatocellular nodular hyperplasia up to 5 mth after completion of the experimental regimen. The hyperplastic nodules regressed slowly at that time. Cystic bile duct hyperplasia emerged with high frequency between 5 and 15 mth after completion of the regimen. The nitrosamine-initiated nodular and biliary hyperplasias could not be unequivocally accepted as preneoplastic lesions since frankly neoplastic transformation under these conditions was a relatively rare occurrence.

Animals↗
PubMed1982

Streptozotocin induced diabetic nephropathy and renal tumors in the rat.

Adult Wistar rats rendered diabetic by a single dose of streptozotocin develop renal morphological changes which show subtle differences compared to those seen in human diabetic renal disease. The early tubular degeneration is sited in the distal rather than the proximal convoluted tubule and subsequent glomerular lesion shows linear deposits of IgG and albumin in the basement membrane rather than in the mesangium. The carcinogenicity of streptozotocin in the rat is reconfirmed.

Adenoma↗
PubMed1980

A combined histochemical and autoradiographic study of the distribution and maturation of peritoneal mast cells in the rat.

The relationship of mitotic activity and degree of cytological differentiation for mast cells of the peritoneal cavity of the rat was studied using combined autoradiographic and histochemical techniques. A mitotic pool of mast cells can be differentiated from a non-mitotic pool, the former containing cells with immature cytoplasmic differentiation and the latter with fully developed cytoplasmic histochemical properties.

Aging↗
PubMed1980

Regeneration of lymphatic vessels in the ear of the guinea pig.

The regenerative capacity of injured lymphatic trunks was compared to that of lymphatic capillaries following physical and chemical injuries using the techniques of micro-injection. Some transected lymphatic trunks regenerate whereas lymphatic trunks having 2 mm segments excised did not regenerate. Flow of lymph was diverted to collateral vessels. In contrast to lymphatic trunks, lymphatic capillaries showed remarkable regenerative capacity following both physical and chemical injuries.

Animals↗
PubMed1979

The mast cell: III. Distribution and maturation in various organs of the young rat.

The changing population-density of mast cells in various organs was plotted for rats aged 1/2 to 90 days and correlated with histochemical studies on the stage of maturation of cells. Mast cells are present at birth in liver and spleen and are particularly associated with foci of haemopoiesis. In bone marrow mast cells are absent at birth but become progressively more numerous with increasing age of the animal. The association of mast cells firstly with foci of extramedullary haemopoiesis and secondly with medullary foci coupled with their detection in peripheral blood strongly suggests that mastopoiesis may be analogous with granulopoiesis. In thymus mast cells are usually associated with interlobular connective tissue stroma, but in the parenchyma they are found toward the medullary side of the cortico-medullary junction. Such a distribution suggests the possible origin of mast cells from lymphocyte or thymocyte. In other tissues examined mast cells are frequently associated with connective tissue stroma and blood vessels.

Age Factors↗
PubMed1977

The mast cell: II. Distribution and maturaiton in the peritoneal cavity of the young rat.

In rats aged 1/2 to 60 days, the development of the mesentery and omentum involves a substantial modification of the inital lymphatic supply of these membranes and the postnatal development of 'milk spots' of the omentum. In both membranes, mast cells are scarce at birth but progressively increase in number and maturation with increasing age of the rat. In the paravascular zones of the mesentery, mast cells are particularly associated with lymphatic vessels, rather than with blood vessels. Mast cells are also scarce at birth in the free peritoneal fluid, but increase progressively in number with increasing age of the rat. The initial population consists of about 90% stage 1 cells and 10% stage 2. Progressive maturation results in successive waves of stage 2 cells during the 2nd week, of stage 3 cells during the 2nd and 3rd weeks, and of stage 4 cells during the 3rd and 4th weeks. These and other results are interpreted to indicate that mast cells in free peritoneal fluid probably arise from free precursor cells rather than by migration from the peritoneal membranes.

Adipose Tissue↗
PubMed1975

The mast cell: distribution and maturation in the peritoneal cavity of the adult rat.

In the peritoneal cavity of the adult rat mast cells at the four stages of progressive maturation (and corresponding increase of sulphation of granules) are best demonstrated in free peritoneal fluid. Of the 0.1-0.2x10(6) cells in the free fluid, 26% are at stage 1 of maturation (all granules are stained by Alcian blue). 24% at stage 2 (majority of granules are stained by Alcian blue, minority by safranin), 20% at stage 3 (majority of granules are safranin-positive), and 30% at stage 4 (all granules are safranin-positive). Peritoneal washings yield a mean of about 1.3-1.8x10(6) mast cells of which 16% are at stage 1, 24% at stage 2, 34% at stage 3 and 26% at stage 4. The greater number recovered by washing, compared with the number in free peritoneal fluid, suggests that a substantial number of mast cells lie on the surface of the peritoneal membranes.

Adipose Tissue↗
PubMedDate not supplied

The regeneration and maturation of mast cells following peritoneal lavage in the rat.

Adult rats subjected to repeated peritoneal saline lavage show a rapid depletion of mast cells in the peritoneal fluid, but the mast cells in mesentery and omentum are not significantly reduced. The residual mast cells are predominantly young elements, histochemically belonging to stages 1 and 2 of maturation. Regeneration of mast cells is rapid with return to the normal density and distribution accomplished within 3 -- 4 weeks after cessation of lavage. The origin, nature and factors influencing the regeneration of mast cells is to be further investigated.

Animals↗