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S Liao

Publications and source records attributed to S Liao.

At least 91 records · Page 5Linked to original sources
PubMed1997

Preputial sebocyte 5alpha-reductase isoform specificity.

We determined whether the 5alpha-reductase (5alpha-R) isozyme specificity in rat preputial sebocytes is in accordance with that of sebaceous glands (type 1 isoform) or with that of other genital tract androgen-dependent organs (type 2). Immunostaining indicated expression of type 1 5alpha-R in preputial epithelial cells in the gland as well as in culture. Northern blots and ribonuclease protection assays both showed the presence of the type 1 isozyme in preputial sebocytes, with little if any expression of the type 2 messenger RNA. Ribonuclease protection assay demonstrated that both homogenized preputial gland and freshly dispersed preputial cells express 2-fold more 5alpha-R type 1 messenger RNA than does skin and 7-fold more than cultured preputial cells. Since cultured preputial cells do not fully differentiate in monolayer culture, these findings suggest that 5alpha-R is increasingly expressed as sebaceous cells differentiate. The predominance of the type 1 isoform in preputial sebocytes is important because it indicates programming by a skin- and sebocyte-specific signal in the midst of the genital tract where the type 2 isoform otherwise predominates.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed1997

[Epstein-Barr virus infection and the expression of bcl-2 proto-oncogene in Hodgkin's disease].

OBJECTIVE: To investigate the relationship between Epstein-Barr virus (EBV) and bcl-2 gene. METHODS: Sixty-four paraffin-embeded cases of Hodgkin's disease (HD) were studied. Immunohistochemistry was performed by using monoclonal antibody to latent membrane protein 1 (LMP-1) and bcl-2. In situ hybridization for EBV encoded small mRNA-EBER on 41 cases. Double staining combined in situ hybridization and immunohistochemistry was performed for dual labelling of EBER and bcl-2 in seven cases. RESULTS: The positive rates of LMP-1 and EBER were 39% and 44%. All cases which were EBER positive, also express LMP-1. The positive rate of bcl-2 protein was 23%. Only seven of these cases were also LMP-1 positive. CONCLUSION: All the results suggest that the bcl-2 expression in the R-S cells in this series did not correlate with EBV-positivity.

Adolescent↗
PubMed1997

[The relation between EB virus and Burkitt's lymphoma].

OBJECTIVE: To study the relationship between Burkitt's lymphoma and Epstein-Barr (EB) virus. METHOD: Two cases of primary nasopharyngeal Burkitt's lymphoma in children were studies. Clinical features include nasal obstruction and dyspnea. The histology of Burkitt's lymphoma was confirmed by use of immunohistochemistry, in situ hybridization and double labelling techniques, the immunophenotype and EB virus locating sites were investigated. RESULTS: The EB positive cells are B cells and represent 60%-95% of the tumor cells. CONCLUSION: Nasopharyngeal primary Burkitt's lymphoma is associated with EB virus in Chinese.

Burkitt Lymphoma↗
PubMed1997

[Dynamic changes of serum antibody titer and liver ultrastructural pathology in acute sporadic hepatitis E virus infected patients].

7 acute hepatitis E patients were tested for anti-HEV IgM and IgG antibodies by EIA. It revealed that anti-HEV IgM and IgG antibody titers were the highest at day 10-45 of the illness, and anti-HEV IgM declined gradually and totally lost within 2 months. Anti-HEV IgG had a similar condition to anti-HEV IgM, but at 7th month there still had 3 cases (40%) remained to be antibody positive. One case was examined for ultrastructural pathology. The swelling of liver cells on the fortieth day of illness was still to be found, the vacuolation of cytoplasm and condensation of mitochondria were present in liver cells.

Acute Disease↗
PubMed1997

[Diagnosis of hepatitis E virus infection in sporadic acute hepatitis].

The solid-phase enzyme immunoassay (EIA) was used for detecting anti-HEV immunoglobulin G (IgG) and M (IgM) by using a recombinant chimeric antigen (ORF3-2) from the open reading frame (ORF) 2 and 3 of hepatitis E virus gene. These sera were collected from the patients with sporadic acute viral hepatitis. The positive rate for anti-HEV IgG was 15.22% (7) among 46 patients with acute hepatitis, 5 of the 7 IgG positive sera were also positive (71.4%) for anti-HEV IgM. 91.8% (93) and 76.4% (78) were positive separately for anti-HEV IgG and IgM among 102 patients of suspected HEV infection (these patients were negative for anti-HAV, anti-HBV and anti-HCV), about 2/3 patients of HEV infection detected were simultaneously HEV-IgG and IgM positive. In control group of 98 normal persons, 4 (4.08%) were positive for anti-HEV IgG, but none were IgM positive. Paired sera of the patients in the acute phase and convalescent phase were detected, the titers of anti-HEV IgG with 4-16 fold decrease were seen in 6 cases and with 2-fold rise in 1 case.

Acute Disease↗
PubMed1997

Decreased vascular smooth muscle cell density in medial degeneration of human abdominal aortic aneurysms.

Abdominal aortic aneurysms (AAAs) are characterized by structural deterioration of the aortic wall leading to progressive aortic dilatation and eventual rupture. The histopathological changes in AAAs are particularly evident within the elastic media, which is normally dominated by vascular smooth muscle cells (SMCs). To determine whether a decrease in vascular SMCs contributes to medial degeneration, we measured SMC density in 21 normal and pathological human abdominal aortic tissue specimens using immunohistochemistry for alpha-SMC actin and direct cell counts (medial SMCs per high-power field (HPF)). Medial SMC density was not significantly different between normal aorta (n = 5; 199.5 +/- 14.9 SMCs/HPF) and atherosclerotic occlusive disease (n = 6; 176.4 +/- 13.9 SMCs/HPF), but it was reduced by 74% in AAA (n = 10; 50.9 +/- 6.1 SMCs/HPF; P < 0.01 versus normal aorta). Light and electron microscopy revealed no evidence of overt cellular necrosis, but SMCs in AAAs exhibited ultrastructural changes consistent with apoptosis. Using in situ end-labeling (ISEL) of fragmented DNA to detect apoptotic cells, up to 30% of aortic wall cells were ISEL positive in AAAs. By double-labeling techniques, many of these cells were alpha-actin-positive SMCs distributed throughout the degenerative media. In contrast, ISEL-positive cells were observed only within the intimal plaque in atherosclerotic occlusive disease. The amount of p53 protein detected by immunoblotting was increased nearly fourfold in AAA compared with normal aorta and atherosclerotic occlusive disease (P < 0.01), and immunoreactive p53 was localized to lymphocytes and residual SMCs in the aneurysm wall. Using reverse transcription polymerase chain reaction assays a substantial amount of p53 mRNA expression was observed in AAAs. These results demonstrate that medial SMC density is significantly decreased in human AAA tissues associated with evidence of SMC apoptosis and increased production of p53, a potential mediator of cell cycle arrest and programmed cell death. Given the role that SMCs normally play in maintaining medial architecture and in arterial wall matrix remodeling, the induction of SMC apoptosis likely makes an important contribution to the evolution of aneurysm degeneration.

Aorta, Abdominal↗
PubMed1997

Extremely low awareness of AIDS, sexually transmitted diseases and condoms among Dai ethnic villagers in Yunnan province, China.

OBJECTIVE: To assess the awareness of AIDS, other sexually transmitted diseases (STDs), condoms, sources of health information and HIV-related societal risks among Dai villagers in southern Yunnan Province, China. SUBJECTS AND METHODS: In November-December 1994, a cross-sectional descriptive study, comprising a questionnaire-based survey and focus group discussions, was conducted in three Dai villages in Mengla county; a total of 177 Dai villagers were interviewed in the survey and eight focus group discussions were held. Ethnographic observations provided a composite picture of HIV risks in the area. RESULTS: Only 18% of respondents had heard of AIDS, and only 25 and 28%, respectively, had heard of STDs or condoms. Furthermore, among these more aware groups, the level of knowledge was low and misconceptions were common. An ability to understand the official language (Mandarin) was the most important predictor of awareness of AIDS, other STDs or condoms. The sources of information in the three Dai villages sampled included TV, videos, radio and magazines, but only TV and videos had a large audience. Even so, these media were mostly in Mandarin and were not used in AIDS education. Travel outside of China was frequent; most villagers (77%) had traveled to Laos and 9% had traveled to Thailand. Societal risks of HIV transmission, such as an increasing incidence of STDs and an active sex industry, were observed in this area. CONCLUSIONS: Dai villagers in southern Yunnan Province had an extremely low awareness and knowledge of AIDS, other STDs and condoms. Given the high mobility of ethnic villagers to neighboring countries in Southeast Asia and the societal risks of HIV transmission in this area, there is an urgent need to provide accessible education about AIDS and other STDs. Suggestions regarding such health education and the implications of HIV policy-making are discussed.

Acquired Immunodeficiency Syndrome↗
PubMed1997

[AFP, uE3, beta-hCG levels applied for prenatal diagnosis of Down's syndrome].

OBJECTIVE: To investigate the relationship between fetal trisomy 21 and alpha fetoprotein (AFP), unconjugated oestriol (uE3) and beta human chorionic gonadotropin (beta-hCG) levels in maternal serum, amniotic fluid and fetal serum. METHOD: AFP, uE3 and beta-hCG levels in maternal serum, amniotic fluid and fetal serum from 17 pregnancies with fetal trisomy 21 and 131 unaffected control pregnancies were measured between 16 to 28 weeks gestation using radioimmunoassay. RESULTS: In these pregnancies with fetal trisomy 21, the AFP and uE3 levels in maternal serum, amniotic fluid and fetal serum were lower than those in controls; but beta-hCG levels were higher (P < 0.05). CONCLUSION: To measure maternal serum AFP, uE3 and beta-hCG levels will be useful in prenatal detection of trisomy 21.

Adult↗
PubMed1997

[Mulivariate analysis of prognostic factors in non-small cell lung cancer].

OBJECTIVES: To find independent prognostic factor of non-small cell lung cancer (NSCLC), identify the population with "high-risk" of recurrence and death in resected NSCLC, and direct adjuvant therapy for clinical doctors. METHODS: 85 resected patients from NSCLC were followed up. All patients were subjected to the study by light microscope, immunochemistry, PCR-SSCP method, and DNA image analysis. Thirteen clinical, pathological, and biological factors were analysed by Cox regression model. RESULTS: The median follow-up period was 47 months. The overall 3-year survival rate was 66% and the overall 5-year survival rate 61%. Cox regression showed significant univariate predictors (P < 0.05) of early recurrence and death for NSCLC were lymphnode status, pTNM, tumor emboli, microvessel count, Ki-67 antigen labeling, DNA relative content and p53 gene mutation. Microvessel count (P < 0.001) and pTNM (P = 0.006) were independent predictors of early recurrence and cancer-death. According to the multivariate model for predicting early recurrence and cancer death, prognostic index (PI) was calculated. CONCLUSION: The PI may be a useful clinical tool for evaluating prognosis of patients and identifying the population with "high-risk" of recurrence and death in NSCLC.

Adenocarcinoma↗
PubMed1996

Human prostate tumor growth in athymic mice: inhibition by androgens and stimulation by finasteride.

When the human prostate cancer cell line, LNCaP 104-S, the growth of which is stimulated by physiological levels of androgen, is cultured in androgen-depleted medium for > 100 passages, the cells, now called LNCaP 104-R2, are proliferatively repressed by low concentrations of androgens. LNCaP 104-R2 cells formed tumors in castrated male athymic nude mice. Testosterone propionate (TP) treatment prevented LNCaP 104-R2 tumor growth and caused regression of established tumors in these mice. Such a tumor-suppressive effect was not observed with tumors derived from LNCaP 104-S cells or androgen receptor-negative human prostate cancer PC-3 cells. 5 alpha-Dihydrotestosterone, but not 5 beta-dihydrotestosterone, 17 beta-estradiol, or medroxyprogesterone acetate, also inhibited LNCaP 104-R2 tumor growth. Removal of TP or implantation of finasteride, a 5 alpha-reductase inhibitor, in nude mice bearing TP implants resulted in the regrowth of LNCaP 104-R2 tumors. Within 1 week after TP implantation, LNCaP 104-R2 tumors exhibited massive necrosis with severe hemorrhage. Three weeks later, these tumors showed fibrosis with infiltration of chronic inflammatory cells and scattered carcinoma cells exhibiting degeneration. TP treatment of mice with LNCaP 104-R2 tumors reduced tumor androgen receptor and c-myc mRNA levels but increased prostate-specific antigen in serum- and prostate-specific antigen mRNA in tumors. Although androgen ablation has been the standard treatment for metastatic prostate cancer for > 50 years, our study shows that androgen supplementation therapy may be beneficial for treatment of certain types of human prostate cancer and that the use of 5 alpha-reductase inhibitors, such as finasteride or anti-androgens, in the general treatment of metastatic prostate cancer may require careful assessment.

Androgen-Binding Protein↗
PubMed1996

In situ monitoring with the Tradescantia bioassays on the genotoxicity of gaseous emissions from a closed landfill site and an incinerator.

A dual monitoring system composed of the Tradescantia-Micronucleus (Trad-MCN) and Tradescantia-Stamen-Hair-Mutation (Trad-SHM) bioassays was utilized to monitor directly the genotoxicity of the gaseous emission at a closed landfill site and around an incinerator. Four of the commonly emitted gaseous agents from the landfill flare pipes, i.e. toluene, ethylbenzene, trichloroethylene and ethyltoluene were also evaluated for their genotoxicity in the laboratory. The in situ monitoring trips (360 km one way) were carried out by transporting the plant cuttings in a clean air box or in an air-tight plastic bag to the site and exposing these test cuttings for 5-7 h. The exposed plant samples were examined for micronuclei frequencies or the pink mutation rate after the appropriate recovery periods (24 h for MCN, 7-11 days for SHM). A total of 20 monitoring trips were made to the landfill, and 8 to the nearby surroundings (100-500 m from the chimney) of the incinerator site in a two year period. The major findings of the Trad-MCN test on the clastogenicity of the gaseous emission from the flare pipe of the landfill site showed positive responses or toxic effects in 6 out of 20 trips, and that from the incinerator showed positive responses in 5 out of the 8 trips. These positive responses were closely associated with the weather, i.e. low wind velocity, high temperature and relative humidity, and especially the distance from the chimney of the incinerator. The MCN frequencies and mutation rates of the Elementary School site (E. Sch) which is about 200 m from the fence of the landfill site were mostly negative, except the test results of three trips. Trad-SHM tests on the mutagenicity of gaseous emissions from the flare pipe of the landfill showed 12 positive responses out of 20 trials and 2 positives out of 4 trials from the incinerator gaseous emissions. The average mutation rate from 20 Trad-SHM monitoring trips is positive when the ANOVA and Dunnett's t-statistic were applied to the consolidated data. There is a significant (0.01) difference between the lab control and the gas exposed groups, and between the field control and gas exposed groups. Results of the Trad-SHM test at the E. Sch. site were mostly negative except for one trip. In general, micronuclei frequencies and mutation rates of the field control groups were relatively higher than those of the lab controls. The Trad-MCN test on pure gases showed positive responses in all 3 repeated tests on toluene (50-892 ppm). The test results of ethylbenzene yielded positive responses at 172 ppm/min and 1549 ppm/min dosages and exhibited toxicity at higher concentrations. Trad-MCN tests on trichloroethylene and ethyltoluene yielded positive responses at around 100-200 ppm/min level. Three repeated Trad-SHM tests on toluene yielded no positive response at low concentrations (4.3-12.9 ppm).

Air Pollutants↗
PubMed1996

Photoaffinity labeling of rat steroid 5 alpha-reductase (isozyme-1) by a benzophenone derivative of a 4-methyl-4-azasteroid.

[1,2-3H]N-4(Benzylbenzoyl)-3-oxo-4-aza-4-methyl-5 alpha-androstane-17 beta-carboxamide ([3H]-4MABP) has been synthesized as a photoaffinity probe of the steroid-binding domain of rat steroid 5 alpha-reductase isozyme-1 (5 alpha R-1). Reversible binding of the probe to 5 alpha R-1 in microsomal preparations yielded a reversible dissociation constant (Kd) of -3 nM, whereas inhibition experiments indicated that the probe had a 50% inhibition concentration of 4.4 nM and was a competitive inhibitor of the enzyme (Ki approximately 3 nM) with respect to testosterone. SDS-PAGE analysis of microsomal, detergent-solubilized, and (6.5%) polyethylene glycol-precipitated fractions of 5 alpha R-I photolyzed with [3H]4MABP in the presence of NADPH showed that the radioactivity was incorporated into a single protein band with a mass of 26 kDa (apparent molecular weight of 5 alpha R-1). UV photolysis was accompanied by an irreversible loss in enzyme activity, consistent with its covalent modification. Increasing the time of UV irradiation and concentration of [3H]4MABP indicated that the half-life and apparent Kd for its photo insertion were approximately 3 min and 7.5 nM, respectively. Photolysis in the presence of a 20-fold excess of N,N-diethyl-4-aza-4-methyl-3-oxo-5 alpha-androstane-17 beta-carboxamide or the 3-carboxysteroid SKF-105111 resulted in partial protection of 5 alpha R-1 from the probe, whereas minimal incorporation of radioactivity was observed in the absence of NADPH or in the presence of NADP+. The results indicate that [3H]4MABP is an effective probe of the steroid (D-ring) binding domain of 5 alpha R-1.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed1996

Neurobehavioral sequelae of severe pediatric traumatic brain injury: a cohort study.

OBJECTIVES: To determine: (1) the magnitude of neurobehavioral deficits following severe traumatic brain injury (TBI) in children, 3 weeks and 1 year after resolution of post-traumatic amnesia (PTA); (2) the relationship between deficits and injury severity; (3) the performance of cases compared to population norms versus individually matched controls. DESIGN: Prospective cohort study. SETTING: Two regional university medical centers. PARTICIPANTS: Cases were 30 children 6 to 15 years old with severe TBI, measured by initial Glasgow Coma Scale (GCS) score and days to reach a GCS score of 15. Controls were individually matched for age, gender, and premorbid academic achievement. MAIN OUTCOME MEASURES: Subjects received the same neurobehavioral tests three weeks and one year after resolution of PTA. Outcomes included individual test scores and variables summarizing results in eight domains. Correlations were calculated between deficits, expressed as case-control differences, and injury severity. RESULTS: Cases showed substantial deficits and performed significantly more poorly than controls at both initial and 1-year testing. At initial testing, cases had an overall score two standard deviations below controls. At 1-year testing their overall score was one standard deviation below controls. Greater impairment was found in those who reached a GCS score of 15 after 1 month or who had an initial GCS of 3 to 5. The proportion of cases with deficits and the magnitude of deficits at both testing times was underestimated by using population norms instead of controls. CONCLUSIONS: Severe TBI results in significant, persistent deficits related to the level of severity. Comparisons with population norms instead of controls underestimates deficits.

Adolescent↗
PubMed1996

Predictors of family functioning and change 3 years after traumatic brain injury in children.

OBJECTIVES: To examine changes in family functioning from injury to 3 years after pediatric traumatic brain injury; to determine factors most predictive of family outcomes at 3 years and variables that promote positive outcomes and changes over time. DESIGN: Prospective cohort study. SETTING: Two regional tertiary care centers: cases followed for 3 years into community. PARTICIPANTS: Families of 81 children, ages 6 to 15 years, who sustained closed head injury and loss of consciousness (mild = 43, moderate = 20, severe = 18), consecutively enrolled over 15 months. MAIN OUTCOME MEASURES: Family Environment Scale, Family Assessment Device, Family Inventory of Life Events, Health Insurance Survey-General Well-Being, NYU Problem Checklist for Significant Others, Family Interview Rating Scale, Family Global Assessment Scale. All were obtained initially and at 3 months, 1 year, and 3 years postinjury. Predictor variables were selected from the instruments above, as well as from the parent and teacher versions of the Child Behavior Checklist, socioeconomic status, and injury severity. RESULTS: Preinjury functioning was the best predictor of 3-year outcomes. Fewer changes in family functioning were reported over 3 years in the mild or moderate groups, whereas more deterioration occurred in the severe group. At 3 years, one third to one half of parents in either the moderate or severe groups reported medium to high strain in 19 of 34 problem areas. Low levels of family control and high levels of expressiveness correlated with better outcomes for severe group. Positive change for the severe group was marked by better preinjury levels of communication, expressiveness, problem solving, use of resources, role flexibility, greater activity orientation, and less conflict, control, and stress. Preinjury variables and severity explained from 26% to 69% of the variation in 3-year outcomes. CONCLUSIONS: Families at risk for poorer outcomes can be prospectively identified and should be supported and encouraged in their efforts to develop new coping resources.

Adaptation, Psychological↗
PubMed1996

Doxycycline inhibition of aneurysmal degeneration in an elastase-induced rat model of abdominal aortic aneurysm: preservation of aortic elastin associated with suppressed production of 92 kD gelatinase.

PURPOSE: Increased local production of matrix metalloproteinases (MMPs) is a potential mechanism underlying structural protein degradation in abdominal aortic aneurysms (AAA). With an elastase-induced rodent model of AAA, we determined whether pharmacologic treatment with an MMP-inhibiting tetracycline might limit the development of experimental AAA in vivo. METHODS: Forty-eight Wistar rats underwent a 2-hour perfusion of the abdominal aorta with 50 U porcine pancreatic elastase and were then treated with either subcutaneous doxycycline (25 mg/day; n=24) or saline solution vehicle (n=24). Aortic diameter was measured before and after elastase perfusion was performed and before the rats were killed at 0, 2, 7, or 14 days, and AAAs were defined as an increase in aortic diameter to at least twice that before perfusion. At death the aortic tissues were either perfusion-fixed for histologic evaluation or extracted for substrate zymographic evaluation. RESULTS: Aortic diameter was not different between groups at 0 or 2 days, but it was significantly less in animals treated with doxycycline at both 7 and 14 days (mean+/-SEM, p<0.01). After day 2 the incidence of AAA was reduced from 83% (10 of 12 rats treated with saline solution) to 8% (1 of 12 animals treated with doxycycline). By histologic assessment doxycycline prevented the structural deterioration of aortic elastin without decreasing the influx of inflammatory cells. Increased aortic wall production of 92 kD gelatinase observed in a saline solution-treated control group was markedly suppressed in animals treated with doxycycline. CONCLUSIONS: Treatment with an MMP-inhibiting tetracycline inhibits the development of experimental AAA in vivo. This inhibition may be due to selective blockade of elastolytic MMP expression in infiltrating inflammatory cells. Additional experiments, however, are necessitated to fully delineate this process.

Animals↗