PubMed Health⌕ Search

Biomedical subjects

S F Cheng

Publications and source records attributed to S F Cheng.

32 records · Page 2Linked to original sources
PubMed1995

Roquinimex-induced graft-versus-host reaction after autologous bone marrow transplantation.

BACKGROUND: Roquinimex is being used for posttransplantation immunotherapy of autologous bone marrow transplantation for acute and chronic myelogenous leukemia. This immunotherapeutic agent is a cytokine inducer and may induce an autologous graft-versus-host (GVH) and graft-versus-tumor reactions. OBJECTIVE: Our purpose was to examine patients undergoing this immunotherapy for clinical signs and symptoms of acute GVH reactions and to correlate these symptoms with their clinical outcome. METHODS: We studied eight patients receiving requinimex therapy. RESULTS: We found autologous GVH reactions in three of eight patients (38%) treated with this immunotherapy. Their disease was manifested by localized or widespread violaceous papules that on histologic evaluation were compatible with a grade II GVH reaction. The acute cutaneous GVH reaction was associated with eccrine sweat gland necrosis, a dermatologic toxicity usually associated with chemotherapy. CONCLUSION: Long-term studies of larger numbers of patients treated with this immunotherapy will determine whether these GVH reactions confer significant, sustained, antitumor effects.

Acute Disease↗
PubMed1991

Molecular cloning of cDNA of hepatitis C virus (HCV) genome from a healthy carrier in an aboriginal community in Taiwan with high prevalence of HCV infection.

We analyzed hepatitis C virus (HCV) obtained from a healthy HCV carrier in an aboriginal community with high prevalence of HCV infection. By use of random primers and specific oligonucleotide primers, a cDNA fragment of putative non-structural 3 (NS3) region of the HCV genome was cloned by reverse transcription-polymerase chain reaction (RT-PCR) using RNA extracted from a serum sample of a healthy HCV carrier in Taur-Yuan village. The nucleotide and deduced amino acid sequences from the 583 nucleotides long cDNA were compared with those of equivalent region of HCV of other previously reported clones: [J1, HCV-J (regarded as major type of HCV in Japan) and US prototype]. They had 93.7% (546/583), 93.1% (543/583) and 80.4% (469/583) homology at the nucleotide level and 96.9% (188/194), 96.9% (188/194) and 91.8% (178/194) homology at the amino acid level, respectively. These results showed that HCV prevalent in an aboriginal community in Taiwan is more similar to Japanese type than to the US prototype.

Amino Acid Sequence↗
PubMed1987

Impaired natural killer cytotoxicity during recrudescence of recurrent herpes simplex virus type 1 infection.

We investigated natural killer (NK) cytotoxicity in patients with recurrent herpes infection by using K562 cells infected with Herpes simplex virus type 1 (HSV-1) as target. The NK cytotoxicity was lower than during convalescence and in controls during recrudescence (0 to 3 days postonset of clinical symptoms; P less than 0.001). In the convalescent phase (4 to 14 days postonset of symptoms) the NK cytotoxicity was significantly higher than in controls (P less than 0.05). These results suggest that low NK cytotoxicity is related to the recurrence of herpes.

Cell Line↗
PubMed1986

Characterization of T cell receptor gamma chain expression in a subset of murine thymocytes.

While much information exists about the structure and function of the clonally distributed T cell receptor (TCR) alpha beta heterodimer, little is known about the gamma protein, the product of a third rearranging TCR gene. An antiserum to a carboxyl-terminal peptide common to several of the murine gamma chain constant regions and a monoclonal antibody to the murine T3 complex were used to identify products of this TCR gene family in a subpopulation of Lyt2-, L3T4- thymocytes. This subpopulation does not express TCR alpha or full-length TCR beta messenger RNA. The gamma chain is a 35-kilodalton (kD) protein that is disulfide-bonded to a 45-kD partner and is associated with the T3 complex. Analysis of the glycosylation pattern of this thymic gamma chain revealed that the major variable region gamma (V gamma) gene transcribed in activated peripheral T cells is absent from this subpopulation. The cells that bear this second T cell receptor may therefore represent a distinct lineage differentiating within the thymus.

Amino Acid Sequence↗
PubMed1986

Studies of natural killer cell activity. I. Normal range of a natural killer cell activity in the healthy Chinese.

This study was undertaken to establish a normal distribution curve for natural killer (NK) cell activity in healthy Chinese. NK cell activity was detected in 123 persons of different age groups, from the newborn to 84 years of age. None had any reported infection. The mononuclear cells were obtained from peripheral blood and cord blood for NK test; K562 cells were used as target cells to assay NK cell activity. The results indicated that cord blood had the lower NK cell activity. Increasing NK cell activity was seen with increasing age. In the 20 year to 49 year range, the NK cell activity reached maximal value. The NK cell activity gradually decreased when the age was greater than 50 years.

Adolescent↗
PubMedDate not supplied

Solution structure studies of the cobalt complex of a bleomycin functional model bound to d(CGCAATTGCG)2 by two-dimensional nuclear magnetic resonance methods and restrained molecular dynamics simulation.

The interaction between the cobalt(III) complex of a bleomycin functional model (AMPHIS-NET) and the oligonucleotide d(CGCAATTGCG)2 and the structural features of the 1:1 ligand-DNA complex have been determined by high-resolution two-dimensional nuclear magnetic resonance methods and restrained molecular dynamics calculations. The intermolecular nuclear Overhauser effect (NOE) cross-peaks between ligand protons and the DNA minor groove protons suggest that the cobalt(III) complex of AMPHIS-NET binds in the minor groove of DNA at the central AATT site. The NOE connectivities also clearly indicate that the H8 pyridine proton and the H2 imidazole proton in the metal-binding domain interact with the H4' sugar proton of C19 and the H4' sugar proton of A5, respectively, which defines a structure where the metal binding moiety of Co(III).AMPHIS-NET participates in binding to the DNA and extends into the region two base pairs beyond the central AATT site in the minor groove. This binding model is in accord with the consistently observed nondiffusion DNA cleavage in locations two to three residues beyond the end of AT-rich binding sites induced by the corresponding iron(II) complexes of AMPHIS-NET and other AMPHIS-lexitropsin hybrids of the bleomycin functional model compounds.

Antiviral Agents↗
PubMedDate not supplied

Comparison of polymerase chain reaction, monoclonal antibody based enzyme immunoassay, and cell culture for detection of Chlamydia trachomatis in genital specimens.

An enzyme immunoassay (EIA; AntigEnz Chlamydia; Northumbria Biologicals, Northumberland, United Kingdom) and a polymerase chain reaction (PCR) assay (Genemed Biotechnologies, San Francisco, CA) were evaluated for the detection of Chlamydia trachomatis in urogenital specimens. Of 324 specimens, 23 were positive by cycloheximide-treated McCoy's cell culture method. Of 23 culture-positive specimens, 20 and 22 were found to be positive by EIA and PCR, respectively. Among 301 culture-negative samples, 4 were found to be positive by both PCR and EIA, 2 were PCR-positive and EIA-negative, and 3 PCR-negative and culture-negative specimens were found to be positive by EIA. In comparing nonculture methods with cell culture technique, combined sensitivities of 87.0% (90.9% in men and 83.3% in women) and 95.6% (90.9% in men and 100% in women), and specificities of 97.7% (99.4% in men and 95.7% in women) and 98.0% (99.4% in men and 96.5% in women) are achieved by EIA and PCR, respectively. The PCR proved to be the more sensitive of these two nonculture methods, and it can be used for the rapid diagnosis of C. trachomatis urogenital infection.

Antibodies, Monoclonal↗