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Biomedical subjects

S S Yang

Publications and source records attributed to S S Yang.

12 recordsLinked to original sources
PubMed1979

Primary Crohn's disease of the appendix: report of 14 cases and review of the literature.

Fourteen patients with primary Crohn's disease of the appendix have been seen in a 12 year period. These patients represent 12.8% of the total number undergoing surgical resection because of Crohn's disease. Twenty-three cases of appendiceal Crohn's disease have been previously reported in the literature. A correct preoperative diagnosis is rarely made; the usual diagnosis is that of acute appendicitis or appendiceal abscess. The removed appendix in twelve of our 14 cases had marked thickening of the wall with transmural fibrosis and often with granulomatous inflammation. The enlarged appendix had an external appearance similar to that of ileal Crohn's disease, and we consider a correct surgical diagnosis might be possible with better awareness of its existence. The diagnosis might be suspected earlier when the clinical course of apparent appendicitis is protracted or atypical. Contrary to the previous estimation of high recurrence rate, this series and the cumulative evidence in the literature show a relatively low rate at 14%. The feared fistula formation following the removal of the appendix has not been seen in either our series or the literature. These patients, however, merit long-term follow-up.

Adolescent↗
PubMed1978

Properties of a transforming virus, KiMSV(RHHV), isolated from a co-culture of rat HTC-H1 cells with K-NRK cells.

Some morphological, biological, immunological and biochemical characterizations of a virus, rat helper virus pseudotype Kirsten sarcoma virus, KiMSV(RHHV), have been presented here. KiMSV(RHHV) has a type C virus ultrastructure. It is strictly rat tropic and is able to transform rat cells in vitro. The possibility of its being a xenotropic mouse virus has been carefully ruled out by exhaustive analyses of host range and immunological studies. Antigenically KiMSV(RHHV) demonstrates cross reactivity with an antiserum specific against rat leukaemia virus, no cross reactivity with antiserum against Moloney leukaemia virus, and only minor cross reactivity with antiserum against cat leukaemia virus. Analysis of virus proteins and glycoproteins by equilibrium acrylamide gradient gel electrophoresis showed that the virus complex possesses both a gp70 fraction and a p30 fraction. KiMSV(RHHV) sediments isopycnically in a linear sucrose gradient at 1.145 to 1.155 g/ml and possesses RNA and reverse transcriptase activity.

Animals↗
PubMed1976

Physicochemical analysis of the deoxyribonucleic acid product of murine intracisternal A particle RNA-directed DNA polymerase.

The nascent DNA transcript of intracisternal A particle RNA-directed DNA polymerase appeared to be covalently linked to an RNA primer. Fidelity of transcription is evident since the DNA transcript hybridized specifically back to 35-70 S RNA of intracisternal A particles but not with heterologous RNAs. This DNA transcript has an approximate molecular weight of 145 000, estimating 350 polynucleotides and base ratios with an excess of dGMP.

Binding Sites↗
PubMed1976

Murine neuroblastoma clones with varying degrees of C-type virus expression.

Three tissue culture clones of neuroblastoma cells derived from the C-1300 tumor in strain A/J mice were found to contain type-C virus-specific gas antigen. None of the clones spontaneously released mouse-tropic type-C viruses although one clone, N-4, spontaneously released a xenotropic virus. Two clones, NB-2A and N-4, could be induced by treatment with 5-iododeoxyuridine and dexamethasone phosphate to produce B-tropic type-C virus, but clone N-18 failed to release either ecotropic or xenotropic virus under several different induction conditions. Karyotype analysis did not reveal specific chromosome deletions in clone N-18.

Animals↗
PubMed1976

Wilms' tumor in adolescence.

Two cases of Wilms' tumor in adolescent males are presented. The clinical and radiographic findings were unusual and both presented atypical gross and microscopic features that could be correlated with the radiographic findings. Histologic examination of both tumors showed evidence of tubular and glomerular maturation, a feature usually associated with Wilms' tumors of early infancy. One of the tumors contained a large amount of cartilage and bone. The other was grossly cystic and incorporated some features of multilocular cystadenoma, a benign metanephric tumor.

Adolescent↗
PubMed1976

Intracytoplasmic inclusion bodies in the chondrocytes of type I lethal achondrogenesis.

Lethal achondrogenesis in the past has been frequently confused with achondroplasia. Clinical and radiologic advances in the last decade have led to clear differentiation of this condition from other types of bone dysplasia. It is further separated into two types on the basis of radiographic and pathologic findings. Re-evaluation of the histologic features has led to the recognition of heretofore unrecognized intracytoplasmic inclusion bodies in the chondrocytes of type 1 achondrogenesis. The finding of inclusions strengthens the differentiation of the two types and may have implications for the pathogenesis of the form of chondrodystrophy.

Bone and Bones↗
PubMed1976

Rescue of a rat tropic rat hepatoma virus pseudotype Kirsten sarcoma virus by co-cultivation of hepatoma tissue culture cells with K-NRK cells.

A rat tropic rat hepatoma virus pseudotype Kirsten sarcoma virus has been rescued from a co-culture of rat hepatoma tissue culture cells, HTC-HI, with Kirsten murine sarcoma transformed non-producer rat kidney cells (K-NRK). The virus complex, RHHV-KiMSV, released from the co-culture exhibited cell transformation ability on normal rat kidney (NRK) cells and showed a restricted host range limited to rat embryo fibroblasts and other normal rat cell lines. Evidence derived from indirect immunofluorescence assays demonstrated the association of rat helper virus specific gs-I and gs-3 antigens with RHHV-KiMSV transformed cells. RHHVKiMSV is currently being cultured at a titre as high as 10(4) f.f.u./ml in tissue culture, and thus offering opportunity for biochemical studies of rat viruses.

Animals↗
PubMedDate not supplied

Ataxia-telangiectasia and hepatocellular carcinoma.

Ataxia-telangiectasia (AT) is a multi-system disease involving the cerebellum, cutaneous blood vessels and the immune system including both cellular and humoral components. It also involves hematological, endocrine and peripheral nervous systems. This disease is often associated with abnormal liver function tests, such as, raised alkaline phosphatase and various nonspecific histological changes in the liver. High incidence of various malignancies involving lymphoreticular, gastrointestinal and mesenchymal organs have reported in ataxia-telangiectasia. Elevated levels of alpha fetoprotein have been noted commonly in this disorder. In spite of the hepatic histological and biochemical changes associated with elevated alpha fetoprotein, to our knowledge, development of hepatocellular carcinoma has not been reported in patients with ataxia-telangiectasia. A case of a young white female with AT who developed hepatocellular carcinoma along with significantly elevated levels of alpha fetoprotein is presented.

Adult↗