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Biomedical subjects

H J Yang

Publications and source records attributed to H J Yang.

At least 91 records · Page 5Linked to original sources
PubMed1975

Effect of carbamylation of lysine epsilon-amino groups on the activity of blood group specific glycoproteins.

Carbamylation of epsilon-amino groups of lysine of human blood group MM glycoprotein, some of its precursors and the blood group A B antigens gave products with 41% - 91% epsilon-amino group substitution. Even the most extensive carbamylation led to only marginal changes in the circular dichroic (CD) spectra of these substances and none in sedimentation coefficients studied. Nevertheless, carbamylation resulted in either increased or unchanged or decreased inhibitory activity of all blood group antigens tested depending solely on the source of the hemagglutinin used. Carbamylation of epsilon-amino groups of these blood group glycoproteins therefore leads to minor conformational changes, not involved with the primary blood group specificity, which is recognized by a large proportion but not by all corresponding antibodies and lectins.

ABO Blood-Group System↗
PubMed1968

Hemoglobin variant common to Chinese and North American Indians: alpha-2-beta-22 Glu-Ala.

An electrophoretically slow hemoglobin variant, in which the structural change involves the replacement of a glutamyl residue by alanyl at position beta-22, was reported in two groups of North American Indians: hemoglobin-G Coushatta, in Alabama-Coushatta Indians in Texas; and hemoglobin-G Saskatoon, in descendants of Santee Indians living in Canada. Hemoglobin-G Hsin-Chu, found in Taiwan in a Chinese from the northern Chinese province of Liaoning, is now shown to have the same structural anomaly.

Alanine↗
PubMedDate not supplied

Xenotransplantation of human decay accelerating factor transgenic porcine kidney to non-human primates: 4 years experience at a Canadian center.

From July 1999 to December 2002, a total of 27 baboons underwent transplantation with human decay accelerating factor (hDAF) transgenic porcine kidneys. The immunosuppressive protocol included combinations of 1 or more of the following immunosuppressive agents: cyclosporine, TPC, cyclosphophamide, methylprednisolone, GAS914 (a polymeric alpha-Gal), rabbit antithymocyte serum (RATS), and rapamycin derivative (RAD). The animals were followed up clinically with monitoring of renal function based on daily creatinine and urinary output. Histopathological examination of the tissue samples was performed after paraffin embedding. Electron microscopy was performed on occasion. All pathology was read blindly with a semiquantitative scoring method to assess the presence or absence of histological features of xenotransplant rejection. Mean survival time was 20.7 days (range, 4-75 days) with 15 animals dying of classic humoral rejection and 12 dying of complications unrelated to rejection. The most frequent complications were as follows: chronic diarrhea with malabsorption, bleeding diathesis, infections, and drug toxicity. Irrespective of the immunosuppressive regimen, a significant number of baboons (10) developed untreatable diarrhea and gastrointestinal bleeding. Samples of their gastrointestinal tracts showed evidence of varying degrees of necrotizing vasculitis with immunoglobulin (Ig)G,IgM, and fibrin deposition. The survival in pig-to-baboon kidney xenotransplantation continues to be limited by acute xenograft rejection and complications of immunosuppression. Although significantly increased survivals have been obtained, an ideal protocol has not yet been achieved. Efforts will continue in an attempt to develop a protocol with minimal complications and long-term survival beyond 90 days.

Animals↗
PubMedDate not supplied

Quantification of human papillomavirus DNA in the plasma of patients with cervical cancer.

Plasma human papillomavirus (HPV)-DNA level was measured to evaluate the clinical usefulness of circulating DNA for cervical cancer management. DNA extracted from pretreatment plasma of 50 cervical cancer patients and from serial longitudinal plasma of 21 patients was quantified for HPV16/HPV18 by means of quantitative polymerase chain reaction. Another 15 patients with low-grade lesion (LG), 18 patients with high-grade lesion (HG), and 96 normal individuals were studied as controls. Plasma HPV16-DNA was detectable in 50% of cancer patients. The incidence and median level were statistically higher than those in LG patients and normal, but similar to HG patients. Plasma HPV18-DNA was only detected in 6% of cancer patients and 1% of normal. Same type of HPV present in plasma was also detected in its primary tumor; and the level of plasma HPV16-DNA was dependent on the viral load in primary tumor. Plasma HPV-DNA was not detected in 16 of 21 patients after treatment, and those patients had complete response to therapy. HPV-DNA persisted or reappeared in five patients after treatment (one had persistent disease and another had recurrence). Plasma HPV-DNA might be a valuable marker for monitoring therapeutic response and disease progression in cervical cancer.

Adult↗