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Biomedical subjects

H O Kim

Publications and source records attributed to H O Kim.

7 recordsLinked to original sources

Asymmetric synthesis of 1,3-dioxolane-pyrimidine nucleosides and their anti-HIV activity.

In order to study the structure-activity relationships of dioxolane nucleosides as potential anti-HIV agents, various enantiomerically pure dioxolane-pyrimidine nucleosides have been synthesized and evaluated against HIV-1 in human peripheral blood mononuclear cells. The enantiomerically pure key intermediate 8 has been synthesized in nine steps from 1,6-anhydro-D-mannose (1), which was condensed with 5-substituted pyrimidines to obtain various dioxolane-pyrimidine nucleosides. Upon evaluation of these compounds, cytosine derivative 19 was found to exhibit the most potent anti-HIV agent although it is the most toxic. The order of anti-HIV potency was as follows: cytosine (beta-isomer) greater than thymine greater than cytosine (alpha-isomer) greater than 5-chlorouracil greater than 5-bromouracil greater than 5-fluorouracil derivatives. Uracil, 5-methylcytosine, and 5-iodouracil derivatives were found to be inactive. Interestingly, alpha-isomer 20 showed good anti-HIV activity without cytotoxicity. As expected, other alpha-isomers did not exhibit any significant antiviral activity. (-)-Dioxolane-T was 5-fold less effective against AZT-resistant virus than AZT-sensitive virus.

Antiviral Agents

Demonstration of estrogen receptor by immunohistochemical staining in paraffin sections of breast carcinoma.

Paraffin embedded sections of 64 breast carcinomas were stained immunohistochemically using a commercially available monoclonal antibody to estrogen receptor. To improve the sensitivity of the staining, the authors used a Pronase enzyme pretreatment, biotinylated antibody to rat IgG as secondary antibody, streptavidin-alkaline phosphatase as tertiary reagent and fast red as chromogen. When compared to the results of estrogen receptor enzyme immunoassay, this method yielded an 85.9% concordance rate, 86.2% specificity and 85.7% sensitivity. When compared to estrogen receptor immunocytochemistry(ER-ICA) in frozen section and considering the inherent advantages of immunohistochemical staining over biochemical assay, the major advantages of this method are good morphology, suitability for retrospective study and reduced cost of staining due to dilution of expensive primary antibody. Thus, this method offers an alternative to ER assay using fresh tissue and should provide additional valuable information about estrogen receptor.

Adult

[A study on the effect of waiting time for operations in the operating room on preoperative patients].

This study was attempted to provide us with basic information on how to improve understanding with patients for operation, and to offer them better nursing and treatment. This kind of study will help scientific application to nursing practice and operating room. The data was collected by interviewing 29 patients who underwent the elective surgery under the general anesthesia at Y hospital in Seoul. The interview ran from October 15 to December 15, 1989. The research instrument was a anxiety measurement device (SAAI) originally developed by Spielberger, et al and modified by Jung-Tack Kim. 1. Hypothesis Testing Hypothesis one was that there would be a difference in state anxiety level according to a time difference in waiting for operation. This hypothesis was rejected (state anxiety level one hour before operation P greater than .05, r = .747, State anxiety level half an hour before operation P greater than .05, r = .1550, state anxiety level just before operation, P greater than .05, r = .1099). However, state anxiety level appeared to be associated with a longer waiting period, like one day before operation (P less than .05, r = .4628). Hypothesis two was that there would be a difference according to state anxiety level of patients for operation. This was rejected. (Change of blood pressure in systolic P greater than .05, r = -.1082. Change of blood pressure in diastolic P greater than .05, r = -.088, Change of pulse rate, P less than .05, r = 1.909) 2. Examining trait anxiety and state anxiety levels, the average level of trait anxiety was 42.034, and the average level of state anxiety one day before operation was 43,000. The average level of state anxiety was averaged 42.356 in a waiting room for operation. 3. Examining the state anxiety level by time period, the level one hour before was 42.379, the level half an hour before 42.276, and the level just before operation 42.414. The low level of state anxiety was due to the fact that premedication was not eliminated. 4. Age and time period like one day before operation was related to state anxiety level (F = 5.271, P less than .001) and blood pressure in waiting room for operation. That is, state anxiety level and blood pressure of patients one day before operation appeared high. Sex was related to changes of blood pressure; the blood pressure of male patients appeared higher than that of female patients.(ABSTRACT TRUNCATED AT 400 WORDS)

Anxiety

Hepatitis C infection in hemodialysis units.

We performed an epidemiological study of the hepatitis C infection on 112 patients of 3 urban hemodialysis units using a recently developed anti-HCV recombinant based assay. Eleven patients (9.8%) were positive for anti-HCV. Among them, 8 (72.7%) were positive for anti-HBc, one of whom was HBsAg positive and 6 of whom were also anti-HBs positive. Surprisingly, all of the anti-HCV (+) patients were normal alanine aminotransferase. The mean age of the anti-HCV (+) patients was 50.7 +/- 3.3 (mean +/- SE) and that of the anti-HCV (-) was 47.6 +/- 1.3. The mean duration (month) of hemodialysis of the anti-HCV (+) and anti-HCV (-)groups were 52.7 +/- 7.2 (mean +/- SE) and 60.9 +/- 9.7, respectively. The prevalence of anti-HCV among anti-HBc positive subjects was 9.5% and that among anti-HBc negative subjects was 17.6%. This didn't have any statistical significance according to the criteria of the study (p = 0.308). The prevalence of anti-HCV among the transfusion positive group was 11.0% and that of the transfusion negative group was 7.7%. This data showed the tendency for a higher prevalence of anti-HCV among the transfusion positive group, but this also didn't reach statistical significance (p = 0.424). Of the 40 normal controls, none were anti-HCV positive. The prevalence of HBsAg in our hemodialysis units was 12.5%. This rate was not so much higher than the average population in Korea. The prevalence of anti-HCV and previous hepatitis B virus infection also had no significant relationship.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

Skin absorption from patch test systems.

The development of topical drug products requires testing for skin toxicology reactions. A variety of patch test systems are available with which chemicals are applied to skin. The purpose of this study was to determine the skin absorption of paraphenylenediamine (PPDA) from a variety of such systems. [14C]-PPDA (1% pet., USP) was placed in a variety of patch test systems at a concentration normalized to equal surface area (2 mg/mm2). Skin absorption was determined in the guinea pig by urinary excretion of 14C. There was a six-fold difference in the range of skin absorption (p less than 0.02). In decreasing order, % skin absorption from the systems were Hill Top Chamber (53.4 +/- 20.6) greater than Teflon Control patch (48.6 +/- 9.3) greater than Small Finn Chamber with paper disc insert (34.1 +/- 19.8) greater than Small Finn Chamber (29.8 +/- 9.0) greater than Large Finn Chamber (23.1 +/- 7.3) greater than AL-Test Chamber (8.0 +/- 0.8). Thus, the choice of patch system could produce a false negative error if the system inhibits skin absorption, with a subsequent skin toxicology reaction.

Administration, Cutaneous