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Biomedical subjects

W T Ching

Publications and source records attributed to W T Ching.

7 recordsLinked to original sources
PubMed1993

Quantitation of zidovudine-resistant human immunodeficiency virus type 1 in the blood of treated and untreated patients.

A nonselective ex vivo assay was used to directly detect and quantify zidovudine (AZT)-resistant human immunodeficiency virus type 1 (HIV-1) in the blood of treated and untreated patients. In contrast to previous reports, drug-resistant virus was detected in peripheral blood mononuclear cells of a few of the patients who had never received AZT. The AZT resistance of HIV-1 isolates from one untreated individual was confirmed by further susceptibility studies in vitro and by the finding of a characteristic mutation (Lys-->Arg at codon 70) in the reverse transcriptase. In patients who were clinically stable while on AZT, HIV-1 titers in plasma and mononuclear cells were generally low but resistant viruses already predominated. In those individuals who were deteriorating despite AZT administration, high levels of viremia were observed, and the resistance phenotype was nearly universal. These findings serve to emphasize the magnitude of the AZT-resistance problem in patients on drug treatment.

AIDS-Related Complex↗
PubMed1992

Human T lymphotropic virus types I- and II-specific antibody-dependent cellular cytotoxicity: strain specificity and epitope mapping.

Antibody-dependent cellular cytotoxicity (ADCC) against human T lymphotropic virus (HTLV) types I and II was investigated using sera obtained from infected individuals or from rabbits immunized with HTLV-I or -II envelope peptides. Target cells included an HTLV-I-transformed cell line (C91/PL), an HTLV-II-transformed cell line (729pH6neo), and Epstein Barr virus (EBV)-transformed B lymphocytes expressing HTLV-I or -II env or gag gene products after infection with vaccinia/HTLV recombinants. ADCC activity was directed at HTLV-I and -II envelope glycoproteins but not against core (gag) components. In contrast to the human immunodeficiency virus system, significant cross-reactivity between HTLV-I- and -II-directed ADCC activity was observed. Epitope mapping studies using sera from rabbits that had been immunized with HTLV-I or -II envelope peptides suggested that the critical epitopes for ADCC activity are located primarily in hydrophilic regions of the exterior (gp46) part of the envelope glycoprotein.

Animals↗
PubMed1989

Intravenous/oral ciprofloxacin therapy versus intravenous ceftazidime therapy for selected bacterial infections.

The efficacy and toxicity of sequential intravenous and oral ciprofloxacin therapy was compared with intravenously administered ceftazidime in a prospective, randomized, controlled, non-blinded trial. Thirty-two patients (16 patients receiving ciprofloxacin and 16 patients receiving ceftazidime) with 38 infections caused by susceptible Pseudomonas aeruginosa, enteric gram-negative rods, Salmonella group B, Serratia marcescens, Pseudomonas cepacia, and Xanthomonas maltophilia at various sites were evaluable for determination of efficacy. Length of therapy varied from seven to 25 days. Concomitant antimicrobials included intravenously administered beta-lactams for gram-positive organisms, intravenous/oral metronidazole and clindamycin for anaerobes, and intravenous/local amphotericin B for Candida albicans. Intravenous administration of 200 mg ciprofloxacin every 12 hours to 11 patients produced peak serum levels between 1.15 and 3.12 micrograms/ml; trough levels ranged between 0.08 and 0.86 micrograms/ml. Overall response rates were similar for patients receiving ciprofloxacin and ceftazidime. Emergence of resistance was similar in both groups--one Enterobacter cloacae and two P. aeruginosa became resistant after ciprofloxacin therapy and two P. aeruginosa became resistant after ceftazidime therapy. The frequency of superinfection with a variety of organisms was also similar in both groups. Adverse events related to ciprofloxacin included transient pruritus at the infusion site and generalized rash leading to drug discontinuation (one patient each), and with ceftazidime adverse effects included pain at the site of infusion and the development of allergic interstitial nephritis (one patient each). Overall, intravenous/oral ciprofloxin therapy appears to be as safe and effective as intravenous ceftazidime therapy in the treatment of a variety of infections due to susceptible aerobic gram-negative organisms.

Administration, Oral↗
PubMed1987

Legionella infections.

Legionnaires' disease is a distinct clinical entity caused by Legionella pneumophila. Following an epidemic of pneumonia in Philadelphia in 1976, it was found that the bacterium had in fact been first isolated in 1947. Other species of Legionella have been identified, many of which are indistinguishable from L. pneumophila infection. Legionella species also cause extrapulmonary infections and a mild nonpneumonic form of disease known in its epidemic form as Pontiac Fever.

Diagnosis, Differential↗
PubMedDate not supplied

Disseminated Phialophora parasitica infection in humans: case report and review.

A case of recurrent systemic infection caused by Phialophora parasitica occurred in an elderly woman and over a 4-year period was documented (either clinically or at autopsy) to involve two sites on the chest wall, the hip, the vertebral body, and the aorta. The infection was treated with intravenous amphotericin B and a subsequent course of terbinafine. To our knowledge, this is the first reported case of disseminated infection by P. parasitica with systemic involvement as well as of its treatment with terbinafine. The literature on human infection caused by P. parasitica, which is rare and has occurred in both normal and compromised hosts and with and without antecedent trauma, was reviewed; problems encountered both in the laboratory identification of P. parasitica and in therapy were assessed.

Aged↗