Biomedical subjects

M K Cho

Publications and source records attributed to M K Cho.

44 records · Page 3Linked to original sources

PubMed1996

The quality of drug studies published in symposium proceedings.

OBJECTIVE: To compare the quality, relevance, and structure of drug studies published in symposium proceedings that are sponsored by drug companies with 1) articles from symposia with other sponsors and 2) articles in the peer-reviewed parent journals of symposium proceedings; and to study the relation between drug company sponsorship and study outcome. DESIGN: Cross-sectional studies of clinical drug studies published in symposium proceedings or their parent medical journals. MEASUREMENTS: The proportion of articles with no methods sections (which are necessary to assess quality); methodologic quality and clinical relevance scores; and the proportion of articles with outcomes favoring the drug of interest. RESULTS: Symposia sponsored by single drug companies had more articles without methods sections (10%; 108 of 1064) than did symposia that had other sponsors (3%; 58 of 2314) or symposia that had no mentioned sponsor (2%; 29 of 1663) (P < 0.001). The mean methodologic quality and relevance scores of articles were similar both by type of sponsorship and between articles published in symposia sponsored by single drug companies and articles from the parent journals. Significantly more articles with drug company support (98%; 39 of 40) than without drug company support (79%; 89 of 112) had outcomes favoring the drug of interest (P = 0.01). CONCLUSIONS: Articles in symposia sponsored by single drug companies were similar in quality and clinical relevance to articles with other sponsors and to articles published in the parent journals. Articles with drug company support are more likely than articles without drug company support to have outcomes favoring the drug of interest.

Congresses as Topic↗

PubMed1996

Genetic analysis of Borrelia burgdorferi sensu lato in Korea using genomic hybridization and 16S rRNA gene sequence determination.

Nine Borrelia burgdorferi sensu lato isolated in Korea were subjected to genomic hybridization using 16S rRNA gene probe and specific restriction patterns (HindIII and EcoRV) led these nine Borrelia into five subtypes. The evolutionary relationships of the five isolates corresponding to five RFLP groups were measured through the sequence determination of 16S rRNA gene and phylogenetic analysis. The isolates 935T (group I), 934U and 17Y (Group IIa, IIb) were well clustered with B. garinii and B. afzelii. 5MT and 9MT strains (Group IIIa and Group IIIb) formed a common branch shared with B. afzelii cluster although the evolutionary distance was rather long. So, most of B. burgdorferi sensu lato in Korea was B. afzelii or B. afzelii-related group and some minor group such as B. garinii also existed.

Borrelia burgdorferi Group↗

PubMed1995

Extensive colonic stricture due to pelvic actinomycosis.

A 36-year-old woman presented with a palpable tender mass at the left lower quadrant of the abdomen. She had suffered from constipation for five years and had a previous history of intrauterine device-use for one year. Preoperative barium enema and abdominopelvic CT showed a compatible finding of rectosigmoid colon cancer or left ovary cancer. She underwent segmental resection of the sigmoid colon along with the removal of left distal ureter, left ovary and salpinx. Pathologic examination revealed actinomycotic abscesses containing sulfur granules. Thereafter, she took parenteral ampicillin (50mg/kg/day) for one month and oral amoxicillin (250mg, tid) for 2 months consecutively. The patient has no specific problems for 6 months after surgical resection and long-term antibiotic therapy. This report may be the first of intrauterine device-associated pelvic actinomycosis involving both sigmoid colon and rectum extensively.

Actinomycosis↗

PubMed1995

Comparative epidemiological studies on vector/reservoir animals of tsutsugamushi disease between high and low endemic areas in Korea.

Comparative epidemiological studies on vector reservoir animals of tsutsugamushi disease were carried out in between south coast (the highest endemic) areas and east coast (low endemic) areas in October 1993. Fauna of field rodents and their population densities were not different between two areas. Antibody positive rate of Apodemus agrarius sera was higher in east coast (43.2% in south coast and 63.6% in east coast). High correlation (r = 0.87) was shown between antibody positive rate of A. agrarius sera and population density of the vector mites (Leptotrombidium scutellare and L. pallidum). L. scutellare was predominant in south coast, showing 110.6 chigger index (74.9% of the total chiggers), whereas L. pallidum was predominant in east coast, showing 126.3 chigger index (60.4% of the total). As higher population density of L. scutellare was found in south coast where the prevalence rate of tsutsugamushi disease is the highest, it is believed that L. scutellare is more important vector species than L. pallidum, which may result from more frequent vector-human contact.

Animals↗

PubMed1994

Instruments for assessing the quality of drug studies published in the medical literature.

OBJECTIVES: To develop valid and reliable instruments to assess the methodologic quality and clinical relevance of drug studies. DESIGN: We developed an instrument to assess the methodologic quality of articles reporting clinical research and an instrument to measure nonmethodologic measures of quality, such as clinical relevance, generalizability, and adherence to ethical standards. Each instrument was pretested by seven independent, masked reviewers and modified based on interrater agreement and content validity of individual items. We determined correlational validity of the final methodologic quality instrument by comparing quality scores assigned to 10 articles by means of our instrument and a previously published one. PARTICIPANTS: Clinical drug studies published in symposium proceedings and peer reviewed biomedical literature. MAIN OUTCOME MEASURES: Interrater reliability of overall quality scores, measured by intraclass correlation (r) and Kendall's coefficient of concordance (W), and interrater reliability of individual items, by percentage agreement. MAIN RESULTS: The interrater reliability of the pretest methodologic quality instrument was high (r = .89 [95% confidence interval, .73 to .96]; W = 0.64). Correlational validity of the final instrument was suggested by the high degree of concordance with another previously published one (W = 0.74). The interrater reliability of the pretest clinical relevance instrument was moderate (r = .41 [95% confidence interval, .18 to .64]; W = 0.47). Reviewers confirmed the content validity of both instruments. CONCLUSIONS: The two instruments we developed, one measuring methodologic quality and one measuring clinical relevance of articles reporting clinical research, are reliable, valid, and applicable to a variety of research designs.

Drug Evaluation↗

PubMed1992

Study on vector mites of tsutsugamushi disease in Cheju Island, Korea.

Because no reference on trombiculid mites (Acarina: Trombiculidae) in Cheju Island where tsutsugamushi disease is highly endemic had been available, studies on trombiculid mites in Cheju Island were implemented during the period of August 1991-April 1992, and the results obtained are summarized as follows: (1) The species and numbers of the field rodents collected were 143 Apodemus agrarius chejuensis (92.3%), 11 Crocidura lasiura (7.1%) and 1 Micromys minutus (0.6%). From total 12,075 chiggers harvested, 9 species of 4 genera in Trombiculidae were identified. (2) The predominant species through all seasons was L. zetum (43.3%), followed by L. orientale (27.4%) and L. scutellare (26.6%). However, in autumn when the most cases of tsutsugamushi disease occur, L. scutellare was prominently predominant, having 79.8% of the collected chiggers. (3) Among 1,142 L. scutellare examined for Rickettsia tsutsugamushi by means of IFA test, 6 individuals were found positive showing 0.5% of infection rate. This is the first finding that L. scutellare is the second vector species of tsutsugamushi disease in Korea. (4) Antibody positive rate of A. agrarius chejuensis sera were 31.2% (44/139), and 1 M. minutus serum was also found positive. The seropositive rates by season were not so significantly different.

Animals↗

PubMed1991

Determination of the vector species of tsutsugamushi disease in Korea.

In order to determine the vector species of tsutsugamushi disease in Korea, chiggers were individually dissected, and internal contents were tested for Rickettsia tsutsugamushi organisms by means of indirect FA test, and each exoskeleton was mounted on slide for identification. Among 4,142 chiggers collected from 48 Apodemus agrarius at nine different localities during the period of July-November, 1989, 990 chiggers of 10 species of Trombiculidae were dissected and tested. Rickettsiae were confirmed in two Leptotrombidium pallidum larvae out of 447 tested, giving 0.4% of the infection rate. The chiggers of the other species tested were found negative.

Animals↗

PubMedDate not supplied

Effects of cysteine on the pharmacokinetics of intravenous adriamycin in rats with protein-calorie malnutrition.

In rats with protein-calorie malnutrition (PCM, 5% caseine diet for 4 weeks), hepatic cytochrome P450 levels suppressed markedly and cytochrome P450 mRNAs decreased significantly compared with those in control rats (23% caseine diet for 4 weeks), however, the values completely (or partially) returned to control levels by a week (from fourth week) of cysteine supplementation (rats with PCMC) (Cho, Kim et al., Arch. Biochem. Biophys. 1999, 372: 150-158). The formation of aglycone metabolites of adriamycin and adriamycinol, M3 and M4, respectively, seemed to be induced (Lee and Lee, Res. Commun. Mol. Pathol. Pharmacol. 1999, 105: 87-96) by pretreatment with dexamethasone (possibly by hepatic cytochrome P450 RL 33/cDEX, Komori and Oda, J. Biochem. 1994, 116: 114-120) in rats. Adriamycin, 16 mg/kg, was administered intravenously in 1-min to control rats and rats with PCM and PCMC. In rats with PCM, the plasma concentrations of adriamycin was higher (the area under the plasma concentration-time curve from time zero to 12 hr, AUC(0-12 hr), tended to be higher) and 24-hr urinary excretion of M3 (including its 'conjugates') seemed to increase than those in control rats, suggested that the formation of M3 was inhibited in rats with PCM. In rats with PCMC, the plasma concentrations of adriamycin were lower (the AUC(0-12 hr) was significantly smaller) and 24-hr urinary excretion of M3 (including its 'conjugates') were significantly greater than those in rats with PCM, suggested that the formation of M3 increased significantly by cysteine supplementation by restoring the enzyme system(s) that metabolize adriamycin to M3. The altered pharmacokinetic parameters of adriamycin mentioned above in rats with PCM returned to greater than those of control rats after cysteine supplementation (rats with PCMC). Above data suggested that other hepatic cytochrome P450 isozyme(s) which catalyze(s) the formation of M3 from adriamycin could be induced by cysteine supplementation.

Animals↗