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Biomedical subjects

Y L Guo

Publications and source records attributed to Y L Guo.

At least 91 records · Page 5Linked to original sources
PubMed1994

Blood serum levels of PCDFs and PCBs in Yu-Cheng children peri-natally exposed to a toxic rice oil.

Children secondarily exposed through their mothers to a toxic rice oil containing PCDFs and PCBs in the Yu-cheng incident have shown developmental delay even a decade after the incident. Forty-five serum samples were collected from these children in February 1991 ad small amounts analyzed for their contaminant content using sample enrichment and isotope dilution mass spectrometry. In about one-half the samples, detectable levels of PCDFs and PCBs could still be determined with average values for 2, 3, 4, 7, 8-PnCDF and 1, 2, 3, 4, 7, 8-HxCDF of 300 and 620 ng/kg serum lipid, respectively. The mean of the total PCBs on a whole weight basis was 7.5 micrograms/kg. These concentrations of PCDFs and PCBs are still 10 to 25 times higher than those from a matched control population. Although the serum levels did not correlate with developmental delays, those for the two PCDFs but not the total PCBs correlated with duration of breast feeding indicative of postnatal exposure. The results of this study suggest that estimation of past prenatal exposure of children to PCDFs is best carried out using current mother and not current child blood concentrations.

Adult↗
PubMed1994

Musculoskeletal changes in children prenatally exposed to polychlorinated biphenyls and related compounds (Yu-Cheng children).

Fifty-five Yu-Cheng (oil-disease) children born between 1978 and 1985 to mothers who ate PCB-contaminated rice oil in 1978-1979 were studied and compared to age- and sex-matched control subjects in 1991. The children's growth profiles, bone mineral density and soft tissue composition, joint laxity, and serum parathyroid hormone, vitamin D, calcium, alkaline phosphatase, and phosphate were compared. The Yu-Cheng children were 3.1 cm (p < .05) smaller and had less total lean mass and soft tissue mass as compared to the matched control subjects. All other parameters studied were similar in both groups. The shorter height and decreased total lean mass and soft tissue content were only seen in the Yu-Cheng children who were the first born after the ingestion, but not in subsequent children. This was most likely due to decreased body burdens of the PCBs and related contaminants over time in the mothers.

Birth Order↗
PubMed1994

Occupational hand dermatoses of hairdressers in Tainan City.

OBJECTIVES: To determine the prevalence, clinical features, and patterns of hand dermatosis in hairdressers in Tainan, Taiwan, and to examine the associations between patterns of dermatosis and risk factors such as job description, work exposure, and sensitisation to common allergens. METHODS: Interviews, examinations, and patch tests of the hairdressers from nine hairdressing stores randomly selected from Tainan City. Patch test agents included 41 substances with common allergens, shampoo preservatives, hair dyes, permanent waving and bleaching agents. RESULTS: 98 hairdressers finished the examination, 83% of them had occupational dermatosis and 32% had scissor induced scars or wounds. Most of the dermatoses belonged to either dry metacarpophalangeal dermatitis or eczema of the fingers. 44% of the hairdressers showed positive skin reaction to one or more patch test agents. The patch test results were different from previous reports in that the most common allergens were nickel, thimerosal, Captan, Kathon CG, and fragrance mix, and that the sensitivity to hair dye and permanent wave ingredients were low. The dry metacarpophalangeal dermatitis was associated with exposure to shampoo, and the eczema of the fingers with skin sensitivity to patch test agents. CONCLUSION: Hairdressers in Tainan City had a high prevalence of dermatoses including traumatic wounds, and allergic and irritant contact dermatitis. The rates of sensitivity to some of the common sensitising agents were different from previous reports.

Adolescent↗
PubMed1992

Cognitive development of Yu-Cheng ("oil disease") children prenatally exposed to heat-degraded PCBs.

OBJECTIVE: To compare the cognitive development in Taiwanese children who had been exposed prenatally to high levels of heat-degraded polychlorinated biphenyls (PCBs) with control children who were exposed to background levels. The disorder was called Yu-Cheng, "oil disease," in Taiwan. DESIGN: Matched-pair cohort study. SETTING: Communities in central Taiwan in which there had been a cooking-oil contamination and mass poisoning by heat-degraded PCBs in 1978 through 1979. PARTICIPANTS: One hundred eighteen children born between June 1978 and March 1985 during or after their mothers' consumption of contaminated rice oil; 118 children matched for age, sex, neighborhood, maternal age, and parental education and occupational class; and 15 older siblings of exposed children, born before the poisoning. MAIN OUTCOME MEASURES: Cognitive development measured from 1985 through 1990 using the Chinese versions of the Stanford-Binet test and the Wechsler Intelligence Scale for Children, Revised, RESULTS: The exposed children scored approximately 5 points lower on the Stanford-Binet test at the ages of 4 and 5 years and approximately 5 points lower on the Wechsler Intelligence Scale for Children, Revised, at the ages of 6 and 7 years. Children born up to 6 years after their mothers' exposure were as affected as children born within a year or two after exposure when examined at 6 and 7 years of age. Older siblings resembled the control children. CONCLUSION: Children prenatally exposed to heat-degraded PCBs had poorer cognitive development than their matched controls. The effect persisted in the children up to the age of 7 years, and children born long after the exposure were still affected.

Child Development↗
PubMed1992

[The inhibitory effect of high energy shock waves on bladder tumor cell line BIU-87 in vitro].

The cytotoxic effect of high energy shock waves (HESW) on bladder tumor cell line BIU-87 in vitro was evaluated by using the lithotripter Dornier HM3 with voltage 15 kV, impulsation 0, 400 and 800 respectively, water bath 35-37 degrees C and impulse rate 60/min. Cell viability and clonogenicity were decreased, but the cell doubling times were prolonged with the increasing number of HESW impulsation. Both cell growth curves and 3H-thymidine incorporation assay showed the temporary inhibition on the growth of tumor cells, which were viable after HESW. After a period of time, these tumor cells would recover their normal growth ability. For the group received 800 HESW impulses, the first passage of cell growth curve decreased temporarily 24 hours after HESW impulsation. These results indicate that HESW do show a cytotoxic effect on tumor cells in vitro, including acute and chronic lethal effect and temporary growth inhibition. The cytotoxic effect of HESW is positively proportional to the number of impulsation at the condition of definite working voltage.

Animals↗
PubMed1992

Cognitive development of children prenatally exposed to polychlorinated biphenyls (Yu-Cheng children) and their siblings.

An intoxication episode resulting from rice-bran oil (Yu-Cheng) contaminated with polychlorinated biphenyls (PCBs) occurred in Taiwan from 1978 to 1979. After that episode, the authors found 15 Yu-Cheng children who were born to intoxicated mothers after their documented consumption of PCB-contaminated oil; these children had older siblings, born before PCB exposure, without prenatal PCB exposure. The cognitive development of these Yu-Cheng children and the youngest of their elder siblings were assessed annually from 1985 to 1990 using the Chinese version of the Wechsler Intelligence Scale for Children, Revised Version (WISC-R) for those over six years of age. Compared with their elder siblings, the Yu-Cheng children scored significantly lower (p < 0.05) on the verbal intelligence quotient, by 6.8-16.1 points; on performance IQ by 10.2-18.4 points; and on full-scale IQ by 8.9-18.5 points, during the six measurements performed from 1985 to 1990. The differences in WISC-R IQ scores between the two groups have remained unchanged during these six years of follow-up.

Child↗
PubMed1992

[Production and characterization of a group of monoclonal antibodies to human transitional cell carcinoma].

A panel of specific mouse monoclonal antibodies, BIU-H4, BIU-H6, BIU-H9, was obtained by immunization with BIU-87 cells (a transitional cell carcinoma cell line of the bladder), which was blocked by the serum of mouse anti-human lymphocyte. Detailed descriptions were given concerning their reactivity patterns by ABC-ELISA and IIF assays against various cells. They showed positive reactions with transitional cell carcinoma of the bladder and negative with normal bladder. BIU-H6 did not react with any of the other normal or malignant tissues. The subclass of immunoglobulin for BIU-H4,6 was IgG1, for BIU-H9 is IgG2 alpha. The molecular weight of the antigen recognized by BIU-H6,9 is 102 KD.

Animals↗
PubMed1991

[Determination of compound preparation containing unknown absorptive background by UV spectrophotometry].

A novel algorithm of target factor analysis has been developed for detection and correction of unknown absorptive background in multicomponent analysis. The algorithm is based on the property that the estimated spectra can gradually approach the true ones by iterative refinements. Paracetamol and antipyrine contained in compound injection of paracetamol were determined by this method without any preliminary chemical separation. The average recoveries were both 100.0% and the coefficients of variation were 1.1% and 1.0% respectively. The results clearly indicate that the proposed method may also provide a new approach to the analysis of traditional Chinese medicine containing some unknown absorptive components.

Acetaminophen↗
PubMed1990

Mechanism of phosgene-induced lung toxicity: role of arachidonate mediators.

We have previously shown that phosgene markedly increases lung weight gain and pulmonary vascular permeability in rabbits. The current experiments were designed to determine whether cyclooxygenase- and lipoxygenase-derived mediators contribute to the phosgene induced lung injury. We exposed rabbits to phosgene (1,500 ppm/min), killed the animals 30 min later, and then perfused the lungs with a saline buffer for 90 min. Phosgene markedly increased lung weight gain, did not appear to increase the synthesis of cyclooxygenase metabolites, but increased 10-fold the synthesis of lipoxygenase products. Pre- or posttreatment with indomethacin decreased thromboxane and prostacyclin levels without affecting leukotriene synthesis and partially reduced the lung weight gain caused by phosgene. Methylprednisolone pretreatment completely blocked the increase in leukotriene synthesis and lung weight gain. Posttreatment with 5,8,11,14-eicosatetraynoic acid (ETYA), a nonmetabolized competitive inhibitor of arachidonic acid metabolism, or the leukotriene receptor blockers, FPL 55712 and LY 171883, also dramatically reduced the lung weight gain caused by phosgene. These results suggest that lipoxygenase products contribute to the phosgene-induced lung damage. Because phosgene exposure did not increase cyclooxygenase synthesis or pulmonary arterial pressure, we tested whether phosgene affects the lung's ability to generate or to react to thromboxane. Infusing arachidonic acid increased thromboxane synthesis to the same extent in phosgene-exposed lungs as in control lungs; however, phosgene exposure significantly reduced pulmonary vascular reactivity to thromboxane but not to angiotension II and KCl.

5,8,11,14-Eicosatetraynoic Acid↗
PubMed1990

Vicissitude of management of ureteral stones.

Following the use of rigid ureteroscopic lithotripsy (URS) in 1984 and extracorporeal shock wave lithotripsy (ESWL) in 1987, the treatment for ureteral stones has undergone significant changes. Our experience showed that the successful rate of URS for 132 patients was 89.4% and for the upper third was rather low, percutaneous antegrade URS should be considered. 376 patients treated with ESWL in prone position with a successful rate of 96.8%. The applicability of open surgery was reduced to 17.8% in 1987 and 14.5% in 1988.

Adolescent↗
PubMed1989

[The vicissitudes of managing ureteral stones].

Beginning with the use of rigid ureteroscopic lithotripsy (URS) in 1984 and extracorporeal shock wave lithotripsy (ESWL) in 1987, the methods of treatment for ureteral stones have undergone significant changes. The successful rate of URS for 132 cases was 89.4%. The successful rate for the upper third was rather low, so that percutaneous antegrade URS should be considered. For the 376 patients treated with ESWL in prone position, the successful rate was 96.8%. The need of open surgery was further reduced, 17.8% in 1987 and 14.5% in 1988.

Adult↗
PubMed1989

[Extracorporeal shock wave lithotripsy of staghorn stones].

One hundred forty-seven cases of staghorn calculi were treated with HM-3 Dornier lithotripter. The stone located at the right tract in 71, the left 65 and 11 bilaterally. Fifteen cases had stones larger than 6 cm in length, the biggest size was 11 cm in diameter. Majority of the patients in this group underwent multiple ESWL treatment. PCN was needed in only 4 cases. For safety reason, The interval between two ESWL treatment should be more than 1 week. All stones were completely fragmented and discharged no longer than 4 months. The overall procedural complications were relatively low and not severe. Hematuria occurred in all the patients, fever in 8.8% and pain in 12.2%. The results of this study indicate that the majority of staghorn stone could be treated satisfactory with ESWL.

Adolescent↗
PubMed1987

Influence of serum cholesterol and albumin on partitioning of PCB congeners between human serum and adipose tissue.

The influence of serum lipids and proteins on partitioning of individual polychlorinated biphenyl (PCB) congener peaks between human serum and adipose tissue lipid was assessed using regression analysis. Subjects were 55 repair workers who were either currently or previously exposed, and 56 comparison workers without occupational exposure to PCBs. Seven congeners (2,4,5,4'-tetra CB, 2,3,5,2',3',6'-hexa CB, 2,3,4,2',3',6'-hexa CB, 2,3,4,2',4',5'-hexa CB, 3,4,5,3',4'-penta CB, 2,3,4,5,2',3',4'-hepta CB, and 2,3,4,5,2',3',4',5'-octa CB) which had been quantified in both serum and adipose tissue in at least one-third of the total study population were selected for evaluation. Initially the crude correlations between the serum PCB and certain candidate variables were assessed; more than one congener was correlated with serum cholesterol, albumin, triglycerides, low-density lipoproteins, very low-density lipoproteins, age, body fat content, and average servings of fish per day. Stepwise regression of log serum congener concentration on log adipose congener concentration and these variables was performed. Only cholesterol, albumin, and average servings of fish per day were significant for at least one congener peak. Congeners behaved in two groups, depending on their order of chromatographic elution. For 2,4,5,4'-tetra CB, 2,3,5,2',3',6'-hexa CB, and 2,3,4,2',3',6'-hexa CB, log serum concentration was not significantly correlated with log adipose congener concentration, and there was no consistent pattern for significant candidate variables. For congeners 2,3,4,2',4',5'-hexa CB, 3,4,5,3',4'-penta CB, 2,3,4,5,2',3',4'-hepta CB, and 2,3,4,5,2',3',4',5'-octa CB, log serum congener concentration was consistently significantly correlated with log adipose congener concentration and serum cholesterol positively, and with serum albumin negatively. For these four congeners the explanations of variation (R2) in serum congener concentration using adipose congener concentration alone were 3, 23, 20, and 30%, respectively, and after adding cholesterol and albumin were 13, 56, 43, and 46%. Thus we conclude that serum cholesterol and albumin can influence the distribution or partition of PCBs between serum and adipose tissue.

Adipose Tissue↗