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Biomedical subjects

Y C Ko

Publications and source records attributed to Y C Ko.

At least 91 records · Page 5Linked to original sources
PubMed1993

Induction of inflammatory cytokines in the pleural effusion of cancer patients after the administration of an immunomodulator, OK-432: role of IL-8 for neutrophil infiltration.

When OK-432, a well-known streptococcal preparation for an anti-tumour drug, was administered into the pleural cavity of patients with malignant pleurisy, a rapid and prominent leukocytosis, predominantly consisting of neutrophils, was observed in the cavity. Neutrophil infiltration usually peaked 6-9 h after OK-432 administration, and levelled down after 24 h. Prior to the neutrophil accumulation, transient but marked elevation of various inflammatory cytokine levels including IL-1 beta, TNF-alpha, IL-8 and G-CSF was observed. In particular, IL-8 levels increased more than 10-fold, while GM-CSF did not change significantly. A good correlation between IL-8 levels and neutrophil chemotactic response was observed particularly during 0-3 h. Specific neutralization or removal of IL-8 by antibody column abrogated half of the neutrophil chemotaxis, while neutralization of C5a removed around 40%. Sequential removal of IL-8 and C5a abrogated totally 80% of chemotaxis, confirming that these two factors are mostly responsible for the neutrophil chemotaxis in the pleural fluids. These results have suggested that rapid neutrophil infiltration induced by OK-432 in vivo is ascribable largely to IL-8 and in part to C5a.

Adult↗
PubMed1993

Prevalence and characteristics of areca nut chewers among junior high school students in Changhua county, Taiwan.

Some studies indicate that betel quid and its ingredients chewing can produce cell mutagenicity and tumorigenicity. In Taiwan studies, betel quid chewing is the main cause of submucous fibrosis and oral cancer. Understanding the distribution and characteristics of the areca nut chewing population is one of the first steps in the effort to prevent these oral diseases. A stratified cluster random sample of 2442 junior high school students in Changhua county, Taiwan, were surveyed for the habit of areca nut chewing. Significantly more male students chewed areca nut than female students (9.2% vs 0.9%). The proportion of students who were chewing areca nuts increased with increasing (seventh to ninth) grades. Areca nut was used by junior high school students at a higher rate in village (rural) areas as compared to town (semi-urban) and city (urban) areas (6.4%, 3.7% and 3.0%, respectively). More students in the ordinary achievement classes were chewing areca nuts than those in the high achievement classes (8.4% vs 1.6%). Areca nut chewing students tended to have users in their families. Cigarette smoking and alcohol drinking were positively associated with areca nut chewing. More than half (53.6%) of the areca nut chewing students first experimented with this habit with a family member, most often the father or grandfather.

Adolescent↗
PubMed1993

Elevated interleukin-8 levels in the urine of patients with urinary tract infections.

Pyuria is one of the main features of urinary tract infections (UTI). Nevertheless, the mechanism of polymorphonuclear leukocyte (PMN) recruitment into the urine remains to be investigated. We examined whether interleukin-8 (IL-8), a potent neutrophil chemoattractant and activator, was involved in pyuria seen in UTI. Of 113 patients, 112 had elevated levels of IL-8 in their urine (1,078.0 +/- 181.5 pg/ml), regardless of whether they had an upper or lower UTI; this was in contrast to undetectable levels (less than 16 pg/ml) in the urine of all of the 20 normal individuals and 74 control patients without UTI. A concomitant study revealed increases in urine IL-6, but not IL-1 beta, and tumor necrosis factor alpha levels in patients with UTI. In addition to gram-negative bacteria, a wide spectrum of microorganisms was capable of inducing IL-8 production in urine. Local production of IL-8 in the urinary tract was suggested by a urine IL-8 level that was higher than the paired serum IL-8 level. The urine IL-8 level correlated with the number of PMN in the urine, and an average of half of the chemotactic activity in urine from patients with UTI could be abrogated by anti-IL-8 antibody treatment in vitro. Furthermore, urine IL-8 purified from patients was bioactive and showed multiple forms on immunoblotting analysis. This is the first documentation of IL-8 in the urine of patients with UTI, and these results imply that IL-8 is involved in inducing PMN migration into the urinary tract.

Adolescent↗
PubMed1993

Killing effect of gamma irradiation on Angiostrongylus cantonensis in snails.

Cobalt-60 gamma irradiation was used to kill the larvae of Angiostrongylus cantonensis in four groups of snails that were irradiated at a rate of 15.4 Gy/min for 16.23 min (0.25 kGy), 32.47 min (0.50 kGy), 48.70 min (0.75 kGy), and 64.94 min (1.00 kGy), respectively. Third-stage (infected stage) larvae were isolated from these snails and 50 were administered to each experimental animal via an esophageal tube. At a dosage of 0.25 kGy, the mean +/- SD number of worms recovered from 30 rats and 30 mice was 15.6 +/- 6.5 and 11.3 +/- 6.2, respectively. These were significantly different from the number of worms recovered from the nonirradiated (control) groups, which were 28.9 +/- 9.6 (P < 0.05) and 16.6 +/- 10.3 (P < 0.05) for rats and mice respectively. Worms and cellular infiltrations in lung tissue of rats were histopathologically identified in the 0.25-kGy-irradiated group as well as in the control group. Worms and eosinophilic meningitis were also noted in the brain tissue of mice in control groups. No worms or pathologic findings were observed in the heart, lung, or brain tissue of rats or mice infected with larvae irradiated at or exceeding 0.50 kGy. It is therefore concluded that a dosage of 0.50 kGy is sufficient to prevent successful infection in mice and rats.

Angiostrongylus cantonensis↗
PubMed1993

Prevalence of shoulder and upper-limb disorders among workers in the fish-processing industry.

A cross-sectional study was conducted among fish-processing workers to evaluate the prevalence of shoulder and upper-limb discomforts and to assess the associated ergonomic risk factors. A prestructured interview, a medical check-up, and job analyses were performed to determine musculoskeletal disorders among 207 workers in eight factories. The results showed shoulder girdle pain (30.9%), epicondylitis (14.5%), and carpal tunnel syndrome (15.0%) as the three most common soft-tissue disorders. The odds ratio of shoulder girdle pain was 1.6 (95% CI 1.1-2.5) among the workers who performed tasks with repetitive movement of their upper limbs, while it was 1.8 (95% CI 1.2-2.5) for the workers who sustained forceful movement of their upper limbs during work. Women taking oral contraceptives had a 2.0 times higher odds ratio for carpal tunnel syndrome than did other women. It would appear that untrained or unskilled workers were prone to suffer from musculoskeletal disorders.

Adult↗
PubMed1993

Analysis of a new subtype of HIV-1 gag sequence from a case of vertical transmission in Taiwan.

A Taiwanese woman who lived with a presumably bisexual man of German nationality, and her infant daughter were found to be seropositive for HIV-1. From DNA preparations of peripheral blood mononuclear cells of the mother-infant pair, we amplified a segment, about 560 base pairs (bp), of gag portion of HIV-1 provirus by using polymerase chain reaction (PCR). The high degree of homology (94.7-97.5%) among clones (TM-1 and TM-2 from the mother, and TC-1 and TC-2 from the infant) of gag sequence provided a molecular epidemiological evidence for vertical transmission. However, these sequences exhibited lower degrees of homology (85.1-87.0%) with the corresponding gag segment of a North American HIV-1 subtype (HXB2), and that of a Zairean HIV-1 subtype (Z2Z6). The disparity of sequences between these Taiwanese clones and those of HXB2 and Z2Z6 was particularly prominent in the first (5' proximal) 200 bp, as shown by the low degree of homology (74.8-79.6%) when sequences of TM and TC clones which represented the first 200 bp were compared with those of HXB2 and Z2Z6. The sequence dissimilarity of these clones as compared with HXB2 manifested as transitions more frequently than transversions. Transitions involving G/A to A/G changes were more frequent than those involving T/C to C/T. Transversions involving G/A to T/C changes were slightly more frequent than those involving T/C to G/A changes for all clones except for TM-2 which showed an equal frequency. Presence of stop codons in each of the reading frames of these clones suggests that these may represent defective viral quasispecies. The deduced amino acid sequences from available open reading frames of these clones showed also distinct dissimilarities to HXB2 or Z2Z6. These findings indicate the presence of a gag subtype of HIV-1 which, according to the phylogenetic tree analysis, would represent a new subtype distinct from other known subtypes.

Adult↗
PubMed1993

[The 1991 dengue epidemic in Kaohsiung City].

In Kaohsiung City, dengue fever subsided for two years after the 1987-1988 epidemic. The main reason that it recurred was due to late diagnoses of the dengue fever in patients because of mild or atypical clinical presentations. The first patient contracted dengue fever from Thailand in mid-May, 1991. The disease then spread among his co-workers. Dengue fever was not suspected until the 9th patient contracted it in early July 1991. Through chain transmission, the epidemic spread in the community and even to other parts of Taiwan. There were 113 confirmed dengue cases in Kaohsiung City, and a total of 175 cases on the whole island during the 1991 epidemic. The clinical manifestations were mainly fever, body pain, dizziness, general weakness, and a skin rash. No instances of severe bleeding, shock or dengue hemorrhagic fever were found. Seven dengue 1 and three dengue 3 viruses were isolated from the sera of patients. We found that the clinical severity of the 1991 dengue epidemic was milder, and the viral isolation rate was lower, compared with the 1987-1988 epidemic, although these two outbreaks of dengue fever were both mostly due to dengue type 1. Genetic variation in the dengue virus may be the explanation. Clinically, about 35% of the patients were missed or not reported, although they were finally demonstrated to be dengue fever patients during a patient survey in the epidemic area. For early detection, viral surveys should be performed in new epidemic regions in addition to fixed-spot surveillance.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

[Workplace risk factors associated with eye syndrome in office workers].

Four large sealed office buildings were investigated to determine the relationship between the prevalence of sick building syndrome and the indoor air quality. Questionnaires were distributed to all building occupants. Respondents suffered from upper airway, eye, lower airway and many less specific complaints. Multivariate logistic regression analyses were conducted to assess workplace risk factors associated with eye syndrome. Working with visual display terminals, glare, use of desk lamp, fabric-covered partitions, new carpet, too dim, too bright and lack of openable windows correlated significantly with the prevalence of eye syndrome.

Adult↗
PubMed1993

An in-service education program as a means to improve nurses' knowledge and attitude about AIDS and to increase their willingness to care for AIDS patients.

This study evaluates changes in nurses' knowledge and attitudes about AIDS and changes in their willingness to care for AIDS patients following a 2 hour educational program. The nursing staff of Kaohsiung Medical College Hospital was divided into two groups: an experimental group (n = 280) and a control group (n = 119). Scores were obtained from a pre-test and from a post-test. The questionnaire that was given to both groups. The results were analyzed by 2-way ANOVA with repeated measures. The experimental group's overall pre-test score on their knowledge of AIDS was 25.9 +/- 4.5 (66.4% of the maximal score of 39) and the post-test score showed an improvement to 28.7 +/- 4.2 (73.6% of the maximal score). The difference between the pre-test and post-test scores of the experimental group was statistically significant (P < 0.01). The difference in the post-test scores between the experimental group and the control group (26.0 +/- 4.0) was also statistically significant (P < 0.01). Pertaining to attitudes towards AIDS, the experimental group had a pre-test score of 47.2 +/- 5.2 and a post-test score of 47.3 +/- 5.5, and there was neither a significant difference between the pre-test score and the post-test score of the experimental group nor in the post-test scores between the experimental group and the control group (47.6 +/- 4.3). The post-test score of willingness to care for AIDS patients was slightly higher than the pre-test score in both groups, but the difference was not significant. Nurses who originally were willing to care for AIDS patients had a more positive attitude toward AIDS than did nurses who had originally refused to care for AIDS patients in the pre-test and post-test (p < 0.01). In conclusion, the in-service education apparently enhanced the knowledge of AIDS, however, no statistical difference was established for changes in nurses' attitudes or in their willingness to care for AIDS patients. In order to provide better nursing care, we believe, AIDS knowledge needs to be further promoted.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Pulmonary function and respiratory symptoms of Portland cement workers in southern Taiwan.

Respiratory symptoms and pulmonary function were studied in a cross-sectional survey of Portland cement workers in southern Taiwan. The study cohort consisted of 661 cement workers who were classified into low, medium, and high exposure groups with mean exposure values of 0.22, 0.55 and 1.24 mg/m3 of respirable dust concentrations, respectively. The prevalence of respiratory symptoms was not found to be significantly related to exposure, with the exception of a higher prevalence of coughing found among the heavy exposure group (OR = 1.55, P < 0.05). Both non-smoking and smoking cement workers showed no significant differences in the pulmonary function indices among the three exposure groups.

Adult↗
PubMed1993

[Strategics of medical centers and regional hospitals in response to new labour insurance fee schedule].

The purpose of this paper is to evaluate the medical centers and regional hospitals, strategic response to the implementation of new labour insurance fee schedule. This survey selects fifty-one medical centers and regional hospitals, with the response rate of 92.73%. This questionnaire was developed and evaluated by the authors and mailed to the questionnaire response by hospital's director or relative department director. We have selected Shortell et al. (1985) theory as the framework for evaluating and explaining hospital response to regulation environment (ex: change in the reimbursement system) at institutional-level response (ex: hospital association activity aimed at influencing regulation), managerial-level response (ex: increased physician participation in hospital-wide decision making; starting or expanding a planning department) and technical-level response (ex: shared clinical services such as lab., X-ray, pharmacy). The result found that hospitals with the characteristics as non-public ownership, medical centers, bigger size, and more administrative staff are more inclined to adopt institutional-level response. And a technical-level response occurs to hospital when market competibility becomes more intense which leads to higher reimbursement resource dependency.

Fee Schedules↗
PubMed1992

The predisposing and protective factors against dengue virus transmission by mosquito vector.

An outbreak of dengue fever occurred in Taiwan between 1987 and 1988. The highest attack rate among adults was estimated at 5.6% in the city of Kao-hsiung. A case-control study was carried out to determine the risks of contracting dengue infection and to identify protective factors against the infection. One hundred dengue patients of the authors' hospital who were diagnosed by virologic or serologic tests constituted the case group. Each dengue patient was matched to a control patient of the same age and sex who had been diagnosed as suffering from a non-vector-borne disease on the same day as the dengue patient. Of the household protective measures against dengue infection prior to the occurrence of illness, the adjusted odds ratio, estimated by stratified analysis, was lower for people who lived in screened houses (odds ratio = 0.58, 95% confidence interval 0.36-0.92) as compared with inhabitants of unscreened houses. The odds ratio was as low as 0.18 (95% confidence interval 0.06-0.56) for people whose homes were fully screened with door screens opening outwardly. Patients who lived near markets and/or open sewers or ditches were running a risk of dengue infection 1.8 (95% confidence interval 1.3-2.4) times higher than those who lived elsewhere. To control dengue outbreaks, the authors recommend that special attention should be devoted to the reduction of outdoor vector sources. Full screening, especially outwardly opening screen doors, seems to be an individual's best protection against dengue fever.

Adolescent↗
PubMed1992

Tattooing as a risk of hepatitis C virus infection.

The association of hepatitis C virus (HCV) infection and tattooing was studied in 87 tattooed and 126 tattoo free healthy young men who did not engage in intravenous drug use or multiple sexual activity. Antibody against HCV (anti-HCV) was tested in serum specimens by enzyme immunoassay with C100-3, NS3, and core antigens; 11 of the 87 (12.6%) tattooed and 3 of the 126 (2.4%) tattoo free subjects were positive for anti-HCV (odds ratio = 5.9, 95% CI = 1.6-22.0). A relationship was demonstrated by an increased risk for HCV infection with an increasing number of tattooed site (P(trend) = 0.002). All but one of the 87 tattooed subjects had been infected by hepatitis B virus (HBV) and 25 were carriers of hepatitis B surface antigen (HBsAg). None of the 25 HBsAg carriers was positive for anti-HCV whereas 11 of the 62 HBsAg non-carriers had anti-HCV, suggesting a negative association between the HBsAg carriage and the long lasting anti-HCV (P = 0.02, Fisher's exact). The status of the tattooer was also an important determinant for HCV infection; the risk was higher if tattooing was done by a non-professional friend than by a professional tattooist. Tattooing, probably with improperly sterilized needles, can clearly pose an increased risk for HCV infection in Taiwan. This study indicates the need for legal standards for hygienic tattooing as part of preventive measures for the control of parenterally transmitted infections.

Adolescent↗
PubMed1992

Isotypic and allotypic analysis with monoclonal antibodies and jacalin of 309 serum monoclonal IgA from French and Japanese myeloma patients.

The subclass and allotype distribution of serum monoclonal IgA from myeloma patients was determined by ELISA with monoclonal antibodies in two French and one Japanese laboratory. In addition, the French sera were tested for their reactivity with the lectin jacalin. No significant difference in the isotypic distribution between French and Japanese series could be demonstrated: kappa/lambda ratios were 0.99 and 1.17, and the IgA1 subclass accounted for 93.9% and 91% of cases in the French and Japanese studies, respectively. Five out of 7 myeloma IgA2 from Japan and only one of the 12 IgA2 from France belonged to the A2m(2) allotype (P less than 0.01). All 219 IgA1 tested reacted with jacalin by immunoelectrophoresis (IEP), although with variable intensities. Among IgA2 proteins, only one (of the A2m(1) allotype) yielded a precipitating line with jacalin by IEP. Molecular analysis demonstrated that this protein was an IgA1-IgA2 hybrid bearing most of the A2m(1) epitopes.

Antibodies, Monoclonal↗
PubMed1992

Beyond simple pooling for HIV screening.

We discuss some theoretical features underlying the successful uses of pooling in testing HIV seroprevalence. In particular it is shown that there is a scaling relation for the distribution of positive sera among the pools. A multi-stage pooling method consisting of repeatedly halving the positive pools is proposed. Concentrating on the number of tests required for screening all positive individuals the method is shown to be highly efficient in low prevalence situations.

Biometry↗
PubMed1992

Prevalence of betel quid chewing habit in Taiwan and related sociodemographic factors.

The prevalence of betel quid chewing habit in Taiwan was surveyed in a group of Chinese people from Kaohsiung city and in a second group from the aboriginal inhabitants of South Taiwan. In all 1299 participants constituted Group 1 (85.2% response rate) and 827 Group 2 (70.1% response rate). People were interviewed in their homes in house-to-house survey, according to a structured questionnaire developed and evaluated by the authors. Of the Kaohsiung inhabitants covering all ages and both sexes, 6% was a current betel chewer and 4% was an ex-chewer, whereas 42% of the aborigines aged over 15 yr was a current chewer and 1% an ex-chewer. Lifetime prevalence was 10%. Betel chewing enjoys islandwide popularity among the 20 million inhabitants of Taiwan; the number of current and ex-users was estimated at 2.0 million (95% CI 1.6-2.4 million). The betel quid was prepared in two different ways. In one, used mainly by aborigines, fresh areca nut was simply wrapped with betel leaf and in another, popular mainly among Chinese, a lengthwise piece of betel fruit and lime paste was sandwiched between two halves of an areca nut. A high proportion of chewers was also a smoker and drinker, but tobacco was not found to be chewed together with betel quid. Consumption varied between 14 to 23 portions per day, with individual frequencies ranging widely from 1 to over 200 portions a day. A statistical analysis of sociodemographic factors showed that lesser educated older men, blue collar workers, smokers and drinkers were the likeliest betel chewers.

Adolescent↗
PubMed1992

Strategies for blood screening for the hepatitis C virus and for the human immunodeficiency virus in high risk groups.

For many infectious agents, seroprevalence rate is low but has serious consequences and must therefore be kept out of donated blood supplies. However, screening to ensure the safety of blood supplies has an associated very high cost. For example, in blood banks, detection of all the harmful items in a large number of samples is an expensive and tedious process. The laboratory and statistical approaches to obtain significant savings by the pooling method were discussed from 1943, recently, there have been further discussions of pooling sera as a means to determining the HIV seroprevalence rate in the general population or the weed out all HIV-positive individuals in blood screening. Here we describe a simple mathematical method to weed out all HIV, and HCV seropositive units. The method is designed to maximize possible savings. Two examples illustrate the application of this method in determining the number to be pooled in each stage, and the resulting savings. When the prevalence rate is lower than 2 percent. our method offers savings of over 80 percent.

Blood Donors↗