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Biomedical subjects

C J Liu

Publications and source records attributed to C J Liu.

At least 109 records · Page 6Linked to original sources
PubMed1989

Treatment of severe aplastic anemia: comparison of bone marrow transplantation to immunotherapy.

Between February 1985 and May 1988, sixteen patients with severe aplastic anemia (SAA) post multitransfusion were treated with either allogeneic bone marrow transplantation (BMT) (9) or immunosuppression (7). The latter group was further divided into two subgroups: horse anti-human thymocyte-lymphocyte globulin (ATG-ALG) (2) and high dose methylprednisolone (HDMP) (5). There were 8 males and 8 females, age ranged from 10 to 35 years for the BMT group and 19 to 56 for the immunosuppression group. As of analysis, 9 patients in the BMT group had been followed from 1 to 31 months after transplant (median,24). Graft rejection was noted in 2, both had positive mixed lymphocyte culture (MLC) index. Seven had full recovery of hematopoiesis. Of these 7 survivals, none developed acute graft-versus-host disease (GVHD), whereas 2 had chronic GVHD which resolved completely after a 9-month treatment with azathioprine and prednisolone. Kaplan-Meier survival probability at 31 month was 75%. In the immunosuppressive therapy group 2, who received ATG-ALG both failed the treatment, died 7 and 29 months later, respectively. There were 3 responders in the HDMP subgroup, 1 complete, 2 partial. The 1-year survival probability for this group was 42.9% compared with 75% in the BMT group (p greater than 0.10). However, the hematologic reconstitution and Karnofsky performance were complete in all 7 transplant survivals vs one of 3 in the immunosuppression group (p less than 0.01). This experience supports that for patients with SAA under the age of 40, BMT is the treatment of choice if an HLA-identical MLC-nonreactive marrow donor is available, if not, immunosuppression is an alternative approach.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Studies in monkeys of attenuated hepatitis A variants.

Three HAV variants, H2M20(35 degrees C), H2M20(35 degrees C) and H2M20K5(32 degrees C), were developed by passage in different tissue culture cells and at different temperatures. Virulence for monkeys was assessed by inoculating each of the variants into four monkeys. Weekly bleeding through 16 weeks post-inoculation was assayed for anti-HAV titers and SGPT as well as LDH5 activities. And in some monkeys liver biopsies were also studied. Seroconversion was induced in all of the inoculated monkeys. The anti-HAV titers tested at 16 weeks post-inoculation were: 40-640 with H2M20(35 degrees C), 40-160 with H2M20(32 degrees C) and 20-40 with H2M20K5(32 degrees C). These variants showed different levels of virulence/attenuation for monkeys. Variant H2M20(35 degrees C) showed no evidence of attenuation, variant H2M20(32 degrees C) retained slight virulence and variant H2M20K5(32 degrees C) showed no evidence of virulence for monkeys. Criteria are proposed for assay of HAV virulence tested in monkeys.

Alanine Transaminase↗
PubMed1987

Characterization and structure of genes for proteases A and B from Streptomyces griseus.

Protease A and protease B are extracellular proteins which are secreted by Streptomyces griseus. The genes encoding protease A (sprA) and protease B (sprB) were isolated from an S. griseus genomic library by using a synthetic oligonucleotide probe. Fragments containing sprA and sprB were characterized by hybridization and demonstration of proteolytic activity in Streptomyces lividans. Each DNA sequence contains a large open reading frame with the coding region of the mature protease situated at its carboxy terminus. The amino terminus of each reading frame appears to encode a 38-amino-acid signal peptide followed by a 76- or 78-amino-acid polypeptide, a propeptide, which is joined to the mature protease. Strong homology between the coding regions of the protease genes suggests that sprA and sprB originated by gene duplication.

Amino Acid Sequence↗
PubMed1987

[Establishment of epithelial cell line TBC-27 from a human bladder transitional cell carcinoma and its biological characteristics].

The cell line TBC-27, from a human bladder transitional cell carcinoma Grade II, was established and maintained for 8 months through 27 passages. TBC-27 cells have the epithelioid cell morphology during culture. The population doubling time of the 14th generation cells was 27 hours by growth curve. The chromosome karyotype of the 12th generation cells consisted mainly of hypodiploid (mode 40-45). Ultrastructurally, there was a great deal of freeribosome and vesicle in the cytoplasm and a great number of atypical microvilli on the surface of the 21st generation cells. The heterotransplantation test revealed that the xenografted tumor in the immunosuppressed suckling rats was similar to the initial bladder carcinoma in histology.

Animals↗
PubMed1986

[Cultivation of urologic and male genital tumor cells].

Thirty specimens from 30 patients with urologic and male genital system tumors were cultured. Eighteen (60%) showed initial cell growth. Four (13%) were successful in primary culture. In a renal cell carcinoma and a bladder transitional cell carcinoma, the subcultures were successful after the primary culture. In eight months, having transferred the former for twelve generations and the latter for twenty-seven generations, these two cell lines are established. The morphological characters of the cultured cells, eradication of fibroblasts, conditions of culture and prevention of contamination are discussed.

Carcinoma, Renal Cell↗
PubMed1984

The route of incorporation of nitrogen atom into rifamycin during its biosynthesis.

In this paper, it was first shown that under various conditions of nitrogen supply the rifamycin yield was positively correlated with the mycelial specific activity of glutamine synthetase (GS), then the enhancing effect of glutamine, the product of GS, on rifamycin biosynthesis was demonstrated with resting cell system. The stimulatory effect of glutamine was more pronounced than that of glutamate, and not reduced by a GS specific inhibitor, DON. However, the increase in yield brought about by glutamate, and by asparagine was strongly inhibited by this inhibitor. Glutamine-CO15NH2 amd glutamate-alpha-15NH2 were synthesized and compared for the incorporation of 15N into rifamycin. It was found that the amide nitrogen was incorporated to a much greater extent than the alpha-amino nitrogen, showing that glutamine was a direct precursor of the nitrogen atom in rifamycin. In addition, synthesis of A-32 (C7N), an intermediate secreted by an inactive mutant rif 1, was also greatly stimulated by glutamine, and the synthetic C7N was found to be able to stimulate the biosynthesis of rifamycin. Based upon the above results, the route of incorporation of nitrogen atom into rifamycin is summarized as follows: (Formula: see text).

Ammonium Sulfate↗