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Zeng L, Kong XT, Su JW, Xia TL, Na YQ, Guo YL. Evaluation of germ-cell kinetics in infertile patients with proliferating cell nuclear antigen proliferating index. Asian J Androl 2001; 3:63-6. [PMID: 11250796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023] Open
Abstract
AIM To explore the usefulness of proliferating cell nuclear antigen proliferating index (PCNA PI) in the pathological diagnosis and treatment of male infertility. METHODS Testicular biopsy specimen obtained from 48 cases of male infertility and 2 normal controls were fixed and embedded. The sections were stained with anti-PCNA monoclonal antibodies or haematoxylin/eosin. Proliferating index (PI), expressed as the percentage of germ-cell nuclei positively stained with PCNA antibody, was assessed from more than 20 seminiferous tubules or 600 germ-cells. RESULTS The infertile patients were divided into 4 groups: Group 1, normal spermatogenesis (14 cases); Group 2, hypospermatogenesis (16 cases); Group 3, germinal arrest (10 cases); Group 4, Sertoli cell only syndrome (8 cases). The PCNA PI of normal control testis was 86.5% (mean value). Group 3 had a significantly lower PCNA PI (29.8%) than normal testis; Group 1 and 2 had similar PIs (82.3% and 82.3%, respectively) as the control testis. PI of the negative control (Group 4) was 0 as no germ-cells were found. CONCLUSION PCNA PI is useful for assessing germ-cell kinetics, especially for pathological diagnosis of germinal arrest which is difficult to differentiate by routine HE staining technique. In germinal arrest, there is a significantly lowered PCNA PI, which is an indication of DNA synthesis deterioration, suggesting the use of therapies be different from those for hypospermatogenesis.
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Yue S, Zhang W, Li FL, Guo YL, Liu TL, Huang H. Identification and genetic mapping of four novel genes that regulate leaf development in Arabidopsis. Cell Res 2000; 10:325-35. [PMID: 11271002 DOI: 10.1038/sj.cr.7290059] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Molecular and genetic characterizations of mutants have led to a better understanding of many developmental processes in the model system Arabidopsis thaliana. However, the leaf development that is specific to plants has been little studied. With the aim of contributing to the genetic dissection of leaf development, we have performed a large-scare screening for mutants with abnormal leaves. Among a great number of leaf mutants we have generated by T-DNA and transposon tagging and ethyl-methae sulfonate (EMS) mutagenesis, four independent mutant lines have been identified and studied genetically. Phenotypes of these mutant lines represent the defects of four novel nuclear genes designated LL1 (LOTUS LEAF 1), LL2 (LOTUS LEAF 2), URO (UPRIGHT ROSETTE). and EIL (ENVIRONMENT CONDITION INDUCED LESION). The phenotypic analysis indicates that these genes play important roles during leaf development. For the further genetic analysis of these genes and the map-based cloning of LL1 and LL2, we have mapped these genes to chromosome regions with an efficient and rapid mapping method.
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Yu CT, Guo YL, Zhang ZJ, Xiang BR, An DK. [Effect of solution pH value on the chelation structure of zinc acexamate by electrospray ionization mass spectrometry]. YAO XUE XUE BAO = ACTA PHARMACEUTICA SINICA 2000; 35:913-5. [PMID: 12567914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
AIM To study the effect of solution pH value on the chelation structure of zinc acexamate. METHODS A series of samples at different solution pH values were prepared by 10% HCl or 1 mol.L-1 NH3.H2O. Then API/TOFMS with electrospray ion source was applied to assay the samples. The nitrogen curtain gas and nebulizer gas were adjusted to a constant flow rate of 0.6 microL.min-1 and 2 microL.min-1 respectively. Samples were infused into the electrospray interface using a 500 microL syringe pump at a flow rate of 5 microL.min-1. Mass spectra were acquired in positive ion modes by scanning over the range of m/z 100-1,000. RESULTS The chelation structure of zinc acexamate is stable at pH 2.54 and it can be easy to form the ion (M + ZnY)+ (Y = CH3CONH(CH2)5COO-) and (2M + Na)+ in this condition. CONCLUSION The drug is an effective antiulcer agent. It may decrease the acidity of stomach juice, and form a polymer to protect the ulcer.
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Abstract
Large-scale poisoning occurred in central Taiwan in 1979 from ingestion of cooking oil contaminated by polychlorinated biphenyls (PCBs) and polychlorinated dibenzofurans. To determine whether in-utero exposure to these chemicals alters reproductive function, all prenatally exposed boys and appropriate controls were contacted for medical examination in 1998. Sperm of exposed children have increased abnormal morphology, reduced motility, and reduced capacity to penetrate hamster oocytes. Whether this will cause reduced fecundity, and how these effects can be extrapolated to the general population exposed to background levels of PCBs and dioxin-like chemicals, warrants further investigation.
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Yu ML, Guo YL, Hsu CC, Rogan WJ. Menstruation and reproduction in women with polychlorinated biphenyl (PCB) poisoning: long-term follow-up interviews of the women from the Taiwan Yucheng cohort. Int J Epidemiol 2000; 29:672-7. [PMID: 10922344 DOI: 10.1093/ije/29.4.672] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND In 1979 in Taiwan, about 2000 people were poisoned by cooking oil contaminated with heat-degraded polychlorinated biphenyls (PCBs). Victims developed chloracne and other symptoms; the illness is called Yucheng (oil disease). The chemicals persist in the victims' bodies and some are toxic to the female reproductive system in experimental animals. METHODS In 1993-1994, we identified the living Yucheng women and neighbourhood controls and interviewed them about their reproductive experience. Of the 596 living Yucheng women aged 30-59 years, we found 368, and interviewed 356. We identified 329 controls, and interviewed 312. RESULTS Of the Yucheng women, 16% reported abnormal menstrual bleeding compared to 8% (P < 0.05) of control women; 4.2% versus 1.7% reported a stillbirth since 1979 (P = 0.068). Other characteristics of the menses, fertility, frequency of intercourse, and age at menopause appeared unaffected. More of the Yucheng women reported that one of their offspring had died during childhood (10.2% versus 6.1%, P < 0. 05), and that they had decided to limit childbearing because of health problems (7% versus 2%, P = 0.01). CONCLUSIONS These findings suggest that high level PCB/polychlorinated dibenzofuran (PCDF) exposure has some effect on female endocrine and reproductive function.
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Guo YL, Dai BQ, Li QR, Zhong NC. [The clinical value of click stimuli on the measurement of ipsilateral acoustic reflex thresholds]. LIN CHUANG ER BI YAN HOU KE ZA ZHI = JOURNAL OF CLINICAL OTORHINOLARYNGOLOGY 2000; 14:301-2. [PMID: 12563879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
OBJECTIVE To define that click can substitute for pure tone as a stimulus to measure ipsilateral acoustic reflex thresholds, and to find out the effect of probe frequency on acoustic reflex thresholds. METHOD Using middle ear analyzer (GSI 33, version 2), we measured 23 normal voluntary participants (46 ears) for getting the pure-tone generated ipsilateral acoustic reflex thresholds at different probe frequency and the click evoked ipsilateral acoustic reflex thresholds at click rate 100/s and 180/s for every ear. RESULT For pure tone, the ipsilateral acoustic reflex thresholds at 500 Hz, 1000 Hz, 2000 Hz, were (84.35 +/- 6.96) dB, (84.65 +/- 5.93) dB, (87.96 +/- 6.36) dB by using 226 Hz probe; (93.13 +/- 6.54) dB, (92.70 +/- 6.33) dB, (93.35 +/- 5.99) dB by using 678 Hz probe; (86.52 +/- 4.72) dB, (87.48 +/- 5.00) dB, (88.30 +/- 6.16) dB by using 1000 Hz probe. For click, the ipsilateral acoustic reflex thresholds at click rate 100/s and 180/s were (89.78 +/- 6.83) dB, (92.07 +/- 7.42) dB by using 226 Hz probe; (90.44 +/- 6.76) dB, (90.65 +/- 6.38) dB by using 678 Hz probe; (88.04 +/- 6.87) dB, (88.69 +/- 7.42) dB by using 1000 Hz probe. The acoustic reflex thresholds for 678 Hz probe were higher than those obtained with 226 Hz and 1000 Hz probes. CONCLUSION There were no artifact appearance while stimulus had been click at low rate, so click can be used for the measurement of ipsilateral acoustic reflex thresholds.
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Guo YL, Kurz U, Schultz JE, Lim CC, Wiederanders B, Schilling K. The alpha1/2 helical backbone of the prodomains defines the intrinsic inhibitory specificity in the cathepsin L-like cysteine protease subfamily. FEBS Lett 2000; 469:203-7. [PMID: 10713271 DOI: 10.1016/s0014-5793(00)01281-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Proregions of papain-like cysteine proteases are potent and often highly selective inhibitors of their parental enzymes. The molecular basis of their selectivity is poorly understood. For two closely related members of the cathepsin L-like subfamily we established strong selectivity differences. The propeptide of cathepsin S was observed to inhibit cathepsin L with a K(i) of 0.08 nM, yet cathepsin L propeptide inhibited cathepsin S only poorly. To identify the respective structural correlates we engineered chimeric propeptides and compared their inhibitory specificity with the wild-types. Specificity resided in the N-terminal part, strongly suggesting that the backbone of the prodomain was the underlying structure.
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Guo YL, Lin YC, Sung FC, Huang SL, Ko YC, Lai JS, Su HJ, Shaw CK, Lin RS, Dockery DW. Climate, traffic-related air pollutants, and asthma prevalence in middle-school children in taiwan. ENVIRONMENTAL HEALTH PERSPECTIVES 1999; 107:1001-6. [PMID: 10585904 PMCID: PMC1566819 DOI: 10.1289/ehp.991071001] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
This study compared the prevalence of asthma with climate and air pollutant data to determine the relationship between asthma prevalence and these factors. We conducted a nationwide survey of respiratory illness and symptoms in middle-school students in Taiwan. Lifetime prevalences of physician-diagnosed asthma and of typical symptoms of asthma were compared to air monitoring station data for temperature, relative humidity, sulfur dioxide, nitrogen oxides, ozone, carbon monoxide, and particulate matter with aerodynamic diameter [less than/equal to] 10 microm (PM(10)). A total of 331,686 nonsmoking children attended schools located within 2 km of 55 stations. Asthma prevalence rates adjusted for age, history of atopic eczema, and parental education were associated with nonsummer (June-August) temperature, winter (January-March) humidity, and traffic-related air pollution, especially carbon monoxide and nitrogen oxides, for both girls and boys. Nonsummer temperature, winter humidity, and traffic-related air pollution, especially carbon monoxide and nitrogen oxides, were positively associated with the prevalence of asthma in middle-school students in Taiwan.
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Hsu PC, Hsu CC, Guo YL. Hydrogen peroxide induces premature acrosome reaction in rat sperm and reduces their penetration of the zona pellucida. Toxicology 1999; 139:93-101. [PMID: 10614690 DOI: 10.1016/s0300-483x(99)00107-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Recent studies have demonstrated that mammalian sperm are capable of generating reactive oxygen species (ROS) and that this activity is significantly accelerated in subfertile subjects. The observed decrease in penetration of zona-intact oocyte might be explained by chemical-induced ROS-related early onset of capacitation and premature acrosome reaction, but the mechanism is not clear. We determine whether zona-intact oocyte penetration capability in rat epididymal sperm was affected by premature acrosome reaction in rat sperm treated with hydrogen peroxide (H2O2) and calcium ionophore A23187 or H2O2 and lysophosphatidyl choline. Chlortetracycline fluorescence assay was used to study the status of acrosome reaction on epididymal sperm. The sperm-oocyte binding and penetration assay was used to evaluate the capability for zona pellucida penetration. There was a positive linear correlation between the frequency of acrosome-reacted sperm and capability of sperm-oocyte binding and penetration in zona-free oocytes. In the zona-intact oocytes, the sperm-oocyte penetration rate was suppressed as the proportions of acrosome-reacted sperm increased. In summary, this study showed that premature acrosome reaction reduced rat sperm's capability of penetrating zona-intact oocytes. However, this reduction is not seen in zona-free oocytes. These findings may provide a basis for understanding the effects of sperm ROS generation on zona pellucida penetration in male reproductive toxicology.
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Na YJ, Guo YL, Gu FL. Clinical comparison of selective and non-selective alpha 1A-adrenoceptor antagonists for bladder outlet obstruction associated with benign prostatic hyperplasia: studies on tamsulosin and terazosin in Chinese patients. The Chinese Tamsulosin Study Group. JOURNAL OF MEDICINE 1999; 29:289-304. [PMID: 10503165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
To examine the clinical usefulness of selective and non-selective alpha 1-adrenoceptor antagonists, we compared a selective (tamsulosin) and non-selective (terazosin) alpha 1-adrenoceptor antagonists in the treatment of Chinese patients with benign prostatic hyperplasia (BPH). The study was a single-blind, randomized, multicenter design to compare a fixed dose of tamsulosin (0.2 mg) or terazosin (2 mg) given once daily after breakfast for four weeks. A total of 212 patients were enrolled with 201 patients included in the analysis. The primary variables assessed were changes in total International Prostatic Symptom Score (IPSS), maximum urinary flow rate (Qmax), and average urinary flow rate (AFR) four weeks after dosing. Adverse events were recorded through the treatment period. Both tamsulosin and terazosin produced significant improvements in total IPSS (total score of 11.8 +/- 4.5; decrease in 45.1% and total score of 13.3 +/- 5.3; decrease in 39.0%, respectively) (p < 0.001), Qmax (13.2 +/- 4.1 mL/s, 37.5% increase and 13.6 +/- 3.6 mL/s, 30.8% increase, respectively) (p < 0.001) and AFR (7.7 +/- 3.3 mL/s, 37.5% increase and 7.8 +/- 3.1 mL/s, 25.8% increase, respectively) (p < 0.001) at endpoint. Tamsulosin was superior to terazosin in improvement of total IPSS (p < 0.05) and AFR (p < 0.05). The incidence of adverse events by administration of tamsulosin was less than that by terazosin (13 and 50, respectively; p < 0.01). Among the adverse event, incidence of dizziness (p < 0.001) and hypotension (p < 0.01) by administration of terazosin were significantly greater than that by tamsulosin. Both systolic and diastolic blood pressure of sitting position decreased significantly in patients treated with terazosin (p < 0.01). These results suggest that tamsulosin, a selective alpha 1A-adrenoceptor antagonist, was superior to terazosin, a non-selective alpha 1-adrenoceptor antagonist, in efficacy and adverse events in patients with symptomatic BPH.
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Guo YL, Yu ML, Hsu CC, Rogan WJ. Chloracne, goiter, arthritis, and anemia after polychlorinated biphenyl poisoning: 14-year follow-Up of the Taiwan Yucheng cohort. ENVIRONMENTAL HEALTH PERSPECTIVES 1999. [PMID: 10464071 DOI: 10.2307/3434656] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
In 1979, a mass poisoning involving 2,000 people occurred in central Taiwan from ingestion of cooking oil contaminated by polychlorinated biphenyls (PCBs) and polychlorinated dibenzofurans (PCDFs). We studied the prevalence of medical conditions in the exposed individuals and in a neighborhood control group. Starting with a registry of the exposed individuals from 1983, we updated the addresses of exposed individuals and identified a control group matched for age, sex, and neighborhood in 1979. In 1993, individuals 30 years of age or older were interviewed by telephone. We obtained usable information from 795 exposed subjects and 693 control subjects. Lifetime prevalence of chloracne, abnormal nails, hyperkeratosis, skin allergy, goiter, headache, gum pigmentation, and broken teeth were observed more frequently in the PCB/PCDF-exposed men and women. The exposed women reported anemia 2. 3 times more frequently than controls. The exposed men reported arthritis and herniated intervertebral disks 4.1 and 2.9 times, respectively, more frequently than controls. There was no difference in reported prevalences of other medical conditions. We conclude that Taiwanese people exposed to high levels of PCBs and PCDFs reported more frequent medical problems, including skin diseases, goiter, anemia, and joint and spine diseases.
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Guo YL, Yu ML, Hsu CC, Rogan WJ. Chloracne, goiter, arthritis, and anemia after polychlorinated biphenyl poisoning: 14-year follow-Up of the Taiwan Yucheng cohort. ENVIRONMENTAL HEALTH PERSPECTIVES 1999; 107:715-9. [PMID: 10464071 PMCID: PMC1566448 DOI: 10.1289/ehp.99107715] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
In 1979, a mass poisoning involving 2,000 people occurred in central Taiwan from ingestion of cooking oil contaminated by polychlorinated biphenyls (PCBs) and polychlorinated dibenzofurans (PCDFs). We studied the prevalence of medical conditions in the exposed individuals and in a neighborhood control group. Starting with a registry of the exposed individuals from 1983, we updated the addresses of exposed individuals and identified a control group matched for age, sex, and neighborhood in 1979. In 1993, individuals 30 years of age or older were interviewed by telephone. We obtained usable information from 795 exposed subjects and 693 control subjects. Lifetime prevalence of chloracne, abnormal nails, hyperkeratosis, skin allergy, goiter, headache, gum pigmentation, and broken teeth were observed more frequently in the PCB/PCDF-exposed men and women. The exposed women reported anemia 2. 3 times more frequently than controls. The exposed men reported arthritis and herniated intervertebral disks 4.1 and 2.9 times, respectively, more frequently than controls. There was no difference in reported prevalences of other medical conditions. We conclude that Taiwanese people exposed to high levels of PCBs and PCDFs reported more frequent medical problems, including skin diseases, goiter, anemia, and joint and spine diseases.
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Shiao JS, McLaws ML, Huang KY, Ko WC, Guo YL. Prevalence of nonreporting behavior of sharps injuries in Taiwanese health care workers. Am J Infect Control 1999; 27:254-7. [PMID: 10358228 DOI: 10.1053/ic.1999.v27.a97006] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BACKGROUND Health care workers (HCWs) were surveyed to identify factors associated with nonreporting behavior of sharps injuries (SIs) in Taiwan. METHODS We surveyed 10,469 full-time medical, nursing, technical, and supporting personnel employed at 16 randomly selected hospitals from 132 available accredited teaching hospitals in Taiwan. Information about the most recent injury and reporting behavior after an SI were collected from July 1996 to June 1997 by using a pretested structured questionnaire. Eleven categories, including an open-ended option, were provided for participants to explain their nonreporting behavior. RESULTS Questionnaires were completed by 82.6% (8645) of our sample, of whom 87.3% reported to have experienced a recent SI. A used item was the most commonly (P <. 001) involved item in an SI, and SIs with a used item were significantly more likely (odds ratio 3.6; CI 95%, 3.03-4.26; P <. 001) to be reported compared with an SI that involved unused items. A total of 81.8% of injuries were not reported, with job category significantly affecting reporting behavior (P <.001). Medical staff had the highest nonreporting rate (85.2%). Although attendees of a prevention program were statistically more likely (P <.001) to report an injury compared with nonattendees, the level of reporting in both groups was not encouraging (21.3% and 17.2%, respectively). All reasons given for nonreporting were disconcerting, but none more so than the use of subjective assessment of risk by 21.7% of HCWs who did not report their injuries. Other reasons for not reporting SIs included that the item was unused (34%) and that the HCW was too busy to report the SI (14.9%), unaware of reporting requirements (14. 4%), or immune to hepatitis B virus (12.4%). CONCLUSIONS With 82% of SIs in Taiwanese HCWs going unreported, the expected national incidence will be seriously underestimated and impact the appropriateness of prevention programs. The very low rate of reporting suggests that the current reporting system requires simplification. Because most injuries involved used items, the reporting systems also should include a more responsive management component. The results also suggest that the current prevention programs, currently provided by the general nursing department, require expert content knowledge in infection control if nonreporting and SIs are to be reduced.
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Guo YL, Shiao J, Chuang YC, Huang KY. Needlestick and sharps injuries among health-care workers in Taiwan. Epidemiol Infect 1999; 122:259-65. [PMID: 10355790 PMCID: PMC2809614 DOI: 10.1017/s0950268899002186] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Sharps injuries are a major cause of transmission of hepatitis B and C viruses and human immunodeficiency virus in health-care workers. To determine the yearly incidence and causes of sharps injuries in health-care workers in Taiwan, we conducted a questionnaire survey in a total of 8645 health care workers, including physicians, nurses, laboratory technicians, and cleaners, from teaching hospitals of various sizes. The reported incidence of needlestick and other sharps injuries was 1.30 and 1.21 per person in the past 12 months, respectively. Of most recent episodes of needlestick/sharps injury, 52.0% were caused by ordinary syringe needles, usually in the patient units. The most frequently reported circumstances of needlestick were recapping of needles, and those of sharps injuries were opening of ampoules/vials. Of needles which stuck the health-care workers, 54.8% had been used in patients, 8.2% of whom were known to have hepatitis B or C, syphilis, or human immunodeficiency virus infection. Sharps injuries in health-care workers in Taiwan occur more frequently than generally thought and risks of contracting blood-borne infectious diseases as a result are very high.
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Guo YL, Kang B, Yang LJ, Williamson JR. Tumor necrosis factor-alpha and ceramide induce cell death through different mechanisms in rat mesangial cells. THE AMERICAN JOURNAL OF PHYSIOLOGY 1999; 276:F390-7. [PMID: 10070162 DOI: 10.1152/ajprenal.1999.276.3.f390] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
It has been proposed that ceramide acts as a cellular messenger to mediate tumor necrosis factor-alpha (TNF-alpha)-induced apoptosis. Based on this hypothesis, it was postulated that resistance of some cells to TNF-alpha cytotoxicity was due to an insufficient production of ceramide on stimulation by TNF-alpha. The present study was initiated to investigate whether this was the case in mesangial cells, which normally are insensitive to TNF-alpha-induced apoptosis. Our results indicate that although C2 ceramide was toxic to mesangial cells, the cell death it induced differed both morphologically and biochemically from that induced by TNF-alpha in the presence of cycloheximide (CHX). The most apparent effect of C2 ceramide was to cause cells to swell, followed by disruption of the cell membrane. It is evident that C2 ceramide caused cell death by necrosis, whereas TNF-alpha in the presence of CHX killed the cells by apoptosis. C2 ceramide did not mimic the effects of TNF-alpha on the activation of c-Jun NH2-terminal protein kinase and nuclear factor-kappaB transcription factor. Although mitogen-activated protein kinase [extracellular signal-related kinase (ERK)] was activated by both C2 ceramide and TNF-alpha, such activation appeared to be mediated by different mechanisms as judged from the kinetics of ERK activation. Furthermore, the cleavage of cytosolic phospholipase A2 during cell death induced by C2 ceramide and by TNF-alpha in the presence of CHX showed distinctive patterns. The present study provides evidence that apoptosis and necrosis use distinctive signaling machinery to cause cell death.
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Yang LJ, Guo YL, Trygankova O, Li QY, Maloney JA, Steinhauer M, Williamson JR. Epidermal growth factor and angiotensin II regulation of extracellular signal-regulated protein kinase in rat liver epithelial WB cells. Biochem Pharmacol 1999; 57:425-32. [PMID: 9933031 DOI: 10.1016/s0006-2952(98)00308-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Activation of extracellular signal-regulated protein kinase (ERK) is considered essential for mitogenesis. In the present study, rat liver epithelial WB cells were used to investigate the relative roles of Ca2+, protein kinase C (PKC), and protein tyrosine phosphorylation in mitogenesis and activation of the ERK pathway stimulated by epidermal growth factor (EGF) and angiotensin II (Ang II). The sensitivity of the ERK pathway to Ca2+ was studied by using 1,2-bis (O-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA) to chelate intracellular Ca2+ and a low extracellular Ca2+ concentration to prevent Ca2+ influx. Agonist-induced PKC activation was diminished by inhibition of PKC by GF-109203X (bisindolylmaleimide) or by down-regulation of PKC by long-term treatment of the cells with phorbol myristate acetate (PMA). Our results show that although activation of PKC was critical for mitogenesis induced by Ang II or EGF, the initial activation of ERK by both agonists in these cells was essentially independent of PKC activation and was insensitive to Ca2+ mobilization. This is in contrast to the findings in some cell types that exhibit a marked dependency on mobilization of Ca2+ and/or PKC activation. On the other hand, an obligatory tyrosine phosphorylation step for activation of ERK was indicated by the use of protein tyrosine kinase inhibitors, which profoundly inhibited the activation of ERK by EGF, Ang II, and PMA. Additional experiments indicated that tyrosine phosphorylation by a cytosolic tyrosine kinase may represent a general mechanism for G-protein coupled receptor mediated ERK activation.
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Guo YL, Kang B, Williamson JR. Resistance to TNF-alpha cytotoxicity can be achieved through different signaling pathways in rat mesangial cells. THE AMERICAN JOURNAL OF PHYSIOLOGY 1999; 276:C435-41. [PMID: 9950771 DOI: 10.1152/ajpcell.1999.276.2.c435] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We reported previously that Ro-318220 blocked expression of mitogen-activated protein kinase phosphatase-1 (MKP-1) induced by tumor necrosis factor-alpha (TNF-alpha) and subsequently caused apopotosis in mesangial cells (Y.-L. Guo, B. Kang, and J. R. Williamson. J. Biol. Chem. 273: 10362-10366, 1998). These data support our hypothesis that a TNF-alpha-inducible phosphatase may be responsible for preventing sustained activation of c-Jun NH2-terminal protein kinase (JNK) and consequent cell death in these cells (Y.-L. Guo, K. Baysal, B. Kang, L.-J. Yang, and J. R. Williamson. J. Biol. Chem. 273: 4027-4034, 1998). In this study, we investigated the involvement of protein kinase C (PKC) in regulation of MKP-1 expression in mesangial cells together with effects on viability. Although originally characterized as a PKC inhibitor, Ro-318220 inhibited TNF-alpha-induced MKP-1 expression through a mechanism other than blocking the PKC pathway. Furthermore, inhibition of the PKC pathway neither significantly affected TNF-alpha-induced MKP-1 expression nor made cells susceptible to toxic effect of TNF-alpha. Thus PKC activation is not essential for cells to achieve the resistance to TNF-alpha cytotoxicity displayed by normal mesangial cells. However, activation of PKC by phorbol 12-myristate 13-acetate (PMA) dramatically increased cellular resistance to the apoptotic effect of TNF-alpha. Coincidentally, PMA stimulated MKP-1 expression and suppressed JNK activation. Therefore, PMA-induced MKP-1 expression may contribute to the protective effect of PMA. These results provide a mechanistic explanation for previous documentation that PKC activation can rescue some cells from apopotosis.
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Iida T, Hirakawa H, Matsueda T, Takenaka S, Yu ML, Guo YL. Recent trend of polychlorinated dibenzo-p-dioxins and their related compounds in the blood and sebum of Yusho and Yu Cheng patients. CHEMOSPHERE 1999; 38:981-93. [PMID: 10028655 DOI: 10.1016/s0045-6535(98)00360-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
We investigated the levels of polychlorinated dibenzo-p-dioxins (PCDDs) and their related compounds in blood and sebum from Yusho and Yu-Cheng patients and findings compared with those of normal subjects. Concentrations of these compounds in blood and sebum still were obviously reflected the chemical concentration in the causal rice oil ingested 17 or 26 years since the outbreak. In addition, sebum form the body surface was the most useful sample for monitoring the amount of chemicals contaminating the human body.
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Jiang XJ, Feng T, Chang LS, Kong XT, Wang G, Zhang ZW, Guo YL. Expression of osteopontin mRNA in normal and stone-forming rat kidney. UROLOGICAL RESEARCH 1999; 26:389-94. [PMID: 9879818 DOI: 10.1007/s002400050074] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Human urine contains several macromolecules which inhibit calcium oxalate crystallization. Osteopontin (or uropontin), a secreted phosphoglycoprotein with the amino acid sequence Arg-Gly-Asp (RGD) and high affinity to hydroxyapatite, is one such inhibitor. To investigate the action of this protein on renal stone formation, the expression osteopontin gene in normal and chemically induced urolithiasis rat kidney was compared at both mRNA and protein levels. Northern blot analysis shown a significant increase of osteopontin mRNA level in stone-forming rat kidney compared with normal ones. In an in situ hybridization study, we localized the transcripts of the osteopontin gene in epithelial cells of both distal and collective tubules, and found a remarkably strong signal in stone-forming rats. The amount and distribution of the protein in kidney from immunocytochemistry staining showed the same pattern as seen in situ hybridization. These findings indicate that osteopontin may be an important macromolecule in the normal endogenous defence against the formation of urinary calculi.
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97
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Guo YL, Wang BJ, Yeh KC, Wang JC, Kao HH, Wang MT, Shih HC, Chen CJ. Dermatoses in cement workers in southern Taiwan. Contact Dermatitis 1999; 40:1-7. [PMID: 9928797 DOI: 10.1111/j.1600-0536.1999.tb05968.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Construction workers are known to have occupational dermatoses. The prevalence of such dermatoses was unknown in Taiwanese construction workers. The objective of this study was to determine the work exposure, prevalence of skin manifestations, and sensitivity to common contact allergens in cement workers of southern Taiwan. A total of 1147 current regular cement workers were telephone-interviewed about skin problems during the past 12 months, work exposure, and personal protection. Among those interviewed, 166 were examined and patch tested with common contact allergens. A high % of cement workers reported skin problems in the past 12 months. More men (13.9%) reported skin problems possibly related to work than women (5.4%). Prevalence was associated with lower use of gloves, duration of work as cement worker, and more time in jobs involving direct manual handling of cement, especially tiling. A high % of dermatitis was noted in the 166 workers examined, which correlated with reported skin problems. On patch testing, construction workers had a high frequency of sensitivity to chromate. Sensitivity to chromate or cobalt was associated with reported skin problems, or dorsal hand dermatitis on examination. These workers' dermatitis was under-diagnosed and inadequately managed. It is concluded that cement workers in southern Taiwan had a high prevalence of skin problems related to cement use. Protective measures, work practice, and physician education should be improved to prevent or manage such problems.
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98
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Huang JD, Guo WC, Lai MD, Guo YL, Lambert GH. Detection of a novel cytochrome P-450 1A2 polymorphism (F21L) in Chinese. Drug Metab Dispos 1999; 27:98-101. [PMID: 9884316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023] Open
Abstract
Despite a wide interindividual variation of cytochrome P-450 1A2 (CYP1A2) activity, genetic polymorphism of CYP1A2 has not been reported. By amplification of exons of CYP1A2 by polymerase chain reaction in eight Chinese subjects, the polymerase chain reaction products were directly sequenced. One subject showed heterozygous C2866-->G (Phe21-->Leu) polymorphism. DNA from 157 Chinese subjects (104 polychlorinated biphenyl-exposed subjects and 53 control subjects) was screened for polymorphism by single-strand conformation polymorphism method and MboII endonuclease digestion. Only 1 of 157 samples showed another heterozygous C2866-->G mutation. The subject was previously exposed to polychlorinated biphenyl and showed a value of 3.5% in the caffeine breath test. The value is not significantly higher than the mean value of polychlorinated biphenyl-exposed subjects (3.12 +/- 0.29%, mean +/- S.E.M.). The incidence of the point mutation in these Chinese subjects is less than 1%. The prevalence of the F21L mutation in other ethnic groups and its effect on the metabolic activity of CYP1A2 remain to be further evaluated.
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99
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Yu ML, Hsin JW, Hsu CC, Chan WC, Guo YL. The immunologic evaluation of the Yucheng children. CHEMOSPHERE 1998; 37:1855-65. [PMID: 9828314 DOI: 10.1016/s0045-6535(98)00251-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
The immunologic effects of in utero exposure to polychlorinated biphenyls (PCBs)/polychlorinated dibenzofurans (PCDFs) were evaluated in the Yucheng children in this study. The study subjects consisted of 105 Yucheng children and 101 control children. The Yucheng children were born, between July 1978 and June 1987, to women who had exposed to high dose of PCBs/PCDFs through consumption of contaminated rice bran oil in 1978-1979. These children had been reported to have higher frequencies of bronchitis than their controls in the first six months of life, and higher frequencies of respiratory tract and ear infection in a 6-year follow-up. The low resistance of the Yucheng children to infection suggested that their immune function was suppressed by the PCBs/PCDFs they had exposed to in utero. In the summer and fall of 1995, a thorough physical examination and blood draw were performed on the study children. The Yucheng children were reported by their parents to have higher frequencies of influenza attacks than the control children during the six months prior to the examination. The frequencies of other symptoms were similar between the two groups. The serum levels of various immunoglobulins were similar between the two groups. Fifty-one serum samples, 29 of Yucheng and 22 of control children, were available for cell-mediated immunologic analysis. The percentages of various T cell markers, CD3, CD4, and CD8, and B cell and NK cell markers were not different between the Yucheng and the control children. No dose-response relationship was found between 27 Yucheng children's serum PCB/PCDF levels and any of their immunologic markers. WE concluded that 16 years after the Yucheng incident, Yucheng children exposed to high dose of PCBs/PCDFs in utero did not show, with the serum immunologic marker analyses, suppressed immunity when compared to their controls. To explain the consistent higher frequencies of upper respiratory tract infection in the Yucheng children, immune functional tests such as delayed hypersensitive skin reaction, in vitro lymphocyte proliferation, and antibody synthesis following immunization may be necessary.
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100
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Hsu PC, Hsu CC, Liu MY, Chen LY, Guo YL. Lead-induced changes in spermatozoa function and metabolism. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 1998; 55:45-64. [PMID: 9747603 DOI: 10.1080/009841098158610] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The relationships between sperm reactive oxygen species (ROS) generation, the capacitation process and acrosome reaction, and the spermoocyte penetration rate (SOPR) were investigated to understand the effect of lead toxicity on sperm functions and the mechanisms of these effects. Male Sprague-Dawley rats received weekly intraperitoneal injections of 20 mg or 50 mg lead acetate/kg or 20 mg or 50 mg sodium acetate/kg (control) for 6 wk. Serum testosterone was measured by radioimmunoassay. In cauda epididymal spermatozoa, the chemiluminescence was measured to evaluate the sperm ROS generation. Chlortetracycline fluorescence assay was used to study the status of capacitation and acrosome reaction on fresh cauda epididymal spermatozoa and after 2, 4, or 24 h of incubation with 5 mg/ml bovine serum albumin. In lead-exposed rats, the serum testosterone levels were reduced, and the percentage of capacitation and the chemiluminescence were significantly increased in fresh cauda epididymal spermatozoa. The serum testosterone levels were negatively associated with the percentage of acrosome-reacted spermatozoa. Sperm chemiluminescence was positively correlated with the percentage of both capacitated and acrosome-reacted spermatozoa. The SOPR was negatively associated with the percentage of both capacitated and acrosome-reacted spermatozoa. In summary, this study showed that male rats exposed to lead had decreased serum testosterone levels and that this metal produced early onset of capacitation by one of the pathways of ROS generation. These effects might consequently result in premature acrosome reaction and reduced zona-intact oocyte-penetrating capability.
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