Search PubMed⌕ Search

Biomedical subjects

C Y Huang

Publications and source records attributed to C Y Huang.

At least 55 records · Page 3Linked to original sources
PubMed2001

Effect of percent free prostate-specific antigen measurement on improving the specificity of serum prostate-specific antigen testing in Taiwanese patients.

BACKGROUND AND PURPOSE: Measurement of percent free prostate-specific antigen (fPSA) has been shown to enhance the diagnostic performance of traditional serum PSA determination. We sought to determine whether measurement of percent fPSA could improve the specificity of serum total PSA testing in the detection of prostate cancer in Taiwanese patients with intermediate serum PSA concentrations. METHODS: The medical records of 211 patients examined from March 1998 through March 2000 were analyzed retrospectively; all had a serum total PSA concentration of between 4.1 and 20.0 ng/mL and negative digital rectal examination (DRE) findings, and had undergone a prostate biopsy. Biopsy results were correlated with the serum total PSA concentration and percent fPSA, which were determined using a microparticle enzyme immunoassay. Percent fPSA was calculated as the ratio of fPSA to total PSA multiple by 100. The sensitivity and specificity were calculated and the receiver operating characteristic (ROC) curves were generated from different cutoff values of percent fPSA and total PSA. RESULTS: Thirty-four patients (16.1%) had positive biopsy results (prostate cancer). Patients with positive biopsy results had significantly lower percent fPSA values than those with negative results (11.7% vs 16.0%, p < 0.001). Patients with a lower percent fPSA (< 10%) had a higher probability of a positive biopsy result than those with a high percent fPSA (> 20%) (positive biopsy rate, 29% vs 10%, p < 0.05). Using a cutoff value of 25% fPSA or below, the sensitivity, specificity, and positive predictive value in differentiating patients with positive biopsy results from those with negative results were 97%, 13%, and 18%, respectively. Consequently, 27 unnecessary biopsies could have been avoided at the cost of missing one cancer. The area under the ROC curve was 0.68 for percent fPSA and 0.63 for total PSA (p > 0.05). CONCLUSIONS: For Taiwanese patients with a serum PSA concentration of between 4.1 and 20.0 ng/mL, the incidence of prostate cancer is relatively low; measurement of percent fPSA only weakly enhances the specificity of serum PSA testing in detecting prostate cancer.

Aged↗
PubMed2001

Basic fibroblast growth factor as a growth factor for SRV-2-infected simian retroperitoneal fibromatosis cells, an animal model for AIDS related Kaposi's sarcoma.

Basic fibroblast growth factor (bFGF) and vascular endothelial cell growth factor (VEGF) were demonstrated to be important factors sustaining the growth of Kaposi's sarcoma. RF cells were used to provide a model to study the pathogenesis of Kaposi's sarcoma. In this paper, we demonstrated that bFGF is present in the RF cells, cultured media, and tissues from monkey. The biological activities of bFGF on RF cells were also studied in vitro with serum-free media. The bFGF from serum-free-conditioned media is biologically active to stimulate RF cells in certain media condition. The mitogenic effect was abrogated by sheep neutralizing anti-bFGF antibody. Furthermore, the effect of antibody was reversed by the addition of exogenous bFGF. ELISA measurements indicating the growth potency of conditioned media correlated with the amount of bFGF in the conditioned media. The data from flow cytometry demonstrated the co-existence of SRV-2 and bFGF among RF cells and RF tissues. Immunohistochemical staining of RF tissue blocks for bFGF revealed that bFGF was present in the tumor and the presence of bFGF was not caused by the artifact of tissue culture. These results indicate that bFGF is an important growth factor to promote RF cell growth in vitro and RF tumor in vivo. Further studies are required to determine the relationship between the interaction of bFGF, SRV-2, and VEGF. This model also provides an adequate alternative to the model induced by simian immunodeficiency virus (SIV) to study the Kaposi's sarcoma.

Animals↗
PubMed2001

Combined effects of two sulfonylurea herbicides on soil microbial biomass and N-mineralization.

The interaction effect of two sulfonylurea herbicides, bensulfuron-methyl (B) and metsulfuron-methyl(M), were tested on microbial biomass C, N, N-mineralization and C/N ratio in a loamy sand soil. The herbicides were applied at various levels of: control (B0M0), 0.01 and 0.01 (B1M1), 0.01 and 0.1 (B1M2), and 0.01 and 1.0 (B1M3) microgram/g soil. Determinations of soil microbial biomass-C, N and N-mineralization contents were carried out at 1, 3, 5, 7, 10, 15, 25 and 45 days after herbicides application. The results showed that the soil microbial biomass-C (Cmic) and microbial biomass-N (Nmic) decreased consistently with the increasing rates of herbicides. The results further indicated that B1M1 and B1M2 caused a significant reduction in Cmic and Nmic within first 10 and 7 days of incubation, respectively, as compared with the control. These reductions in Cmic and Nmic were also significant (P = 0.05) with B1M3 application especially within first 15 days of incubation. A significant reduction in N-mineralization (N-min) was observed with high doses (B1M2, B1M3) of herbicides within first 5 days of incubation, while low rate (B1M1) failed to produce any significant effect. An increase in the soil microbial biomass C:N ratio was also noted.

Analysis of Variance↗
PubMed2001

Surgical treatment for Haglund's deformity.

Haglund's deformity, or "pump bump" is a common cause of posterior heel pain, characterized clinically by a painful soft tissue swelling at the level of the Achilles tendon insertion. We reviewed 30 heels in 19 patients with failure of conservative treatment. Surgical management consisted of excision of the posterior calcaneal tuberosity and bursectomy through a medial longitudinal incision. The average follow-up period was 6 years (range, 3-10 years). Only 3 heels (10%) in 2 patients had persistent pain. Twenty-seven heels (90%) were cured after operation. However, 25 heels (83%) had residual pain for a half to two years after operation and became free of symptoms thereafter. We conclude surgical treatment of Haglund's deformity produces a predictably good result (90%) but requires a long time about a half to two years for full recovery.

Adolescent↗
PubMed2001

Childhood tuberculosis presenting as an anterior chest wall abscess.

Chest wall abscess is a rare manifestation of childhood tuberculosis. We report a case of a tuberculous chest wall abscess in a 4-year-old healthy girl who had received Bacillus Calmette-Guerin (BCG) vaccination at birth. She developed a localized anterior chest wall mass, which was initially mistaken for enchondroma on the chest radiograph. Pathologic examination of the biopsy specimen revealed chronic granulomatous inflammation and positive acid-fast staining, which confirmed the diagnosis of chest wall tuberculosis infection. She received a 12-month course of anti-tuberculous treatment and was perfectly well 1 year later. The chest wall lesion resolved without the need for surgery. In conclusion, tuberculosis should be excluded in children with undiagnosed chest wall lesions, especially in endemic areas, even if they have been vaccinated with BCG. Adequate anti-tuberculosis treatment can result in a complete recovery.

Abscess↗
PubMed2000

Alteration in the expression of protein kinase C isoforms in human hepatocellular carcinoma.

This study was designed to investigate the alterations of individual protein kinase C (PKC) isoforms in human liver cancer. Surgical specimens of hepatocellular carcinoma and adjacent normal tissues were extracted into cytosolic and membranous fractions. The level of membrane-bound PKCalpha in the cancer tissue was significantly lower than that in the adjacent normal tissue and consistent with the change in PKC activity. In addition, there was a significant negative correlation between PKCalpha and tumor size. In both cytosolic and membrane fractions, levels of PKCdelta and PKCzeta was significantly higher in the cancer tissue than those in the adjacent normal liver tissue. The alterations in the PKC isoforms signify their roles in the hyperproliferation in liver cancer.

Carcinoma, Hepatocellular↗
PubMed2000

A unified sampling approach for multipoint analysis of qualitative and quantitative traits in sib pairs.

Recent advances in molecular biology have enhanced the opportunity to conduct multipoint mapping for complex diseases. Concurrently, one sees a growing interest in the use of quantitative traits in linkage studies. Here, we present a multipoint sib-pair approach to locate the map position (tau) of a trait locus that controls the observed phenotype (qualitative or quantitative), along with a measure of statistical uncertainty. This method builds on a parametric representation for the expected identical-by-descent statistic at an arbitrary locus, conditional on an event reflecting the sampling scheme, such as affected sib pairs, for qualitative traits, or extreme discordant (ED) sib pairs, for quantitative traits. Our results suggest that the variance about tau&d4;, the estimator of tau, can be reduced by as much as 60%-70% by reducing the length of intervals between markers by one half. For quantitative traits, we examine the precision gain (measured by the variance reduction in tau&d4;) by genotyping extremely concordant (EC) sib pairs and including them along with ED sib pairs in the statistical analysis. The precision gain depends heavily on the residual correlation of the quantitative trait for sib pairs but considerably less on the allele frequency and exact genetic mechanism. Since complex traits involve multiple loci and, hence, the residual correlation cannot be ignored, our finding strongly suggests that one should incorporate EC sib pairs along with ED sib pairs, in both design and analysis. Finally, we empirically establish a simple linear relationship between the magnitude of precision gain and the ratio of the number of ED pairs to the number of EC pairs. This relationship allows investigators to address issues of cost effectiveness that are due to the need for phenotyping and genotyping subjects.

Alleles↗
PubMed2000

Transtentorial cerebellar c-jun expression after focal cerebral cortical injury in mice.

Delayed and remote effect of focal cerebral cortical lesion on cerebellum remains unclear. The c-Jun, an inducible transcription factor of cellular immediate early gene, is the predominant transcription factor and consistent marker for neurons that respond to stress or injury. We use a mouse cryogenic injury model to study the spatial and temporal changes of c-jun in the cerebellum after focal neocortical lesion. A transient and moderate expression of c-jun mRNA was found in the cerebellum with central dominance since 3 day postinjury and gradually subsided within 2 weeks. A distinct increment of c-Jun protein expression in Purkinje cells of the bilateral cerebellar hemispheres with focal connotation in the vermis was detected since 1 week postinjury. These findings suggest that the delayed and remote c-jun expression of the cerebellum, functionally connected with the cerebral cortex, indicate transneuronal gene activation.

Animals↗
PubMed2000

Inositol tetrakisphosphate as a frequency regulator in calcium oscillations in HeLa cells.

Cellular signaling mediated by inositol (1,4,5)trisphosphate (Ins(1, 4,5)P(3)) results in oscillatory intracellular calcium (Ca(2+)) release. Because the amplitude of the Ca(2+) spikes is relatively invariant, the extent of the agonist-mediated effects must reside in their ability to regulate the oscillating frequency. Using electroporation techniques, we show that Ins(1,4,5)P(3), Ins(1,3,4, 5)P(4), and Ins(1,3,4,6)P(4) cause a rapid intracellular Ca(2+) release in resting HeLa cells and a transient increase in the frequency of ongoing Ca(2+) oscillations stimulated by histamine. Two poorly metabolizable analogs of Ins(1,4,5)P(3), Ins(2,4,5)P(3), and 2,3-dideoxy-Ins(1,4,5)P(3), gave a single Ca(2+) spike and failed to alter the frequency of ongoing oscillations. Complete inhibition of Ins(1,4,5)P(3) 3-kinase (IP3K) by either adriamycin or its specific antibody blocked Ca(2+) oscillations. Partial inhibition of IP3K causes a significant reduction in frequency. Taken together, our results indicate that Ins(1,3,4,5)P(4) is the frequency regulator in vivo, and IP3K, which phosphorylates Ins(1,4, 5)P(3) to Ins(1,3,4,5)P(4), plays a major regulatory role in intracellular Ca(2+) oscillations.

Antibodies↗
PubMed2000

Hydrogen peroxide induces apoptosis in human hepatoma cells and alters cell redox status.

Direct exposure of human hepatoma cell line SMMC-7721 to hydrogen peroxide (H2O2) can induce apoptosis. Apoptosis induced by H2O2 was inhibited by cycloheximide, actinomycin D, 3-aminobenzamide, EGTA or Zn2+. H2O2 can increase the level of intracellular Ca2+, downregulate GSH levels, slightly induce lipid peroxidation, and lead to change in the ratio of reduced ion components to oxidized ion components of cells. Analysis of flow cytometry indicates that H2O2 decreases the level of Bcl-2. The data indicate that H2O2-induced apoptosis requires new mRNA and protein syntheses; H2O2 can activate Ca2+/Mg2+-dependent endonuclease leading to internucleosomal DNA fragmentation and activation of poly (ADP-ribose) polymerase interfering with the energy metabolism of the cell. The H2O2 downregulation of GSH may be more important for apoptosis than H2O2 induction of lipid peroxidation, and the H2O2 induced changes in redox status of the cell may be among the original events which lead up to other biochemical changes.

Apoptosis↗
PubMed2000

Development of brain injury in mice by Angiostrongylus cantonensis infection is associated with the induction of transcription factor NF-kappaB, nuclear protooncogenes, and protein tyrosine phosphorylation.

Eosinophilic meningitis or meningoencephalitis caused by Angiostrongylus cantonensis is endemic to the Pacific area of Asia, especially Taiwan, Thailand, and Japan. Although eosinophilia is an important clinical manifestation of A. cantonensis infection, the role of eosinophils in the progress of the infection remains to be elucidated. In this experiment, we showed that A. cantonensis-caused eosinoplia and inflammation might lead to the induction of NF-kappaB and protooncogene expression via activation of the tyrosine phosphorylation signal pathway. After mice were infected daily with 30 third-stage larvae of A. cantonensis by oral adminstration for 6 weeks, no significant differences PKC-alpha, MEK-1, ERK-2, JNK, and p38 protein expression were found between the control and infected mice. However, the protein tyrosine phosphorylation levels, NF-kappaB, and iNOS protein products were significantly increased by 3.5-, 3.3-, and 6.3-fold, respectively, after 3 weeks of A. cantonensis infection. The same pattern was found for c-Myc, c-Jun, and c-Fos proteins, which were elevated by 3.2-, 2.3-, and 3.4-fold, respectively, compared to control animals after 3 weeks. The expression potency of these proteins started increasing in week 1, reaching maximal induction in week 3, and then declining in week 5 after A. cantonensis infection. Another consistent result was noted in the pathological observations, including eosinophilia, leukocyte infiltration, granulomatous reactions, and time responses in brain tissues of infected mice. These data suggest that the development of brain injury by eosinophlia of A. cantonensis infection is associated with NF-kappaB and/or nuclear protooncogenes expression, which is activated by the tyrosine phosphorylation pathway.

Angiostrongylus cantonensis↗
PubMed2000

Anosacral cutaneous amyloidosis: a study of 10 Chinese cases.

BACKGROUND: Primary cutaneous amyloidoses are rare in Western countries, but are relatively common in Taiwan. Anosacral cutaneous amyloidosis is a rare type of primary cutaneous amyloidoses, first reported in Japanese patients. PATIENTS/METHODS: In the present study, we investigated the age of onset, sites of involvement, associated systemic diseases, and histopathological findings in 10 cases of anosacral cutaneous amyloidosis seen during the past 27 years. RESULTS: In previous reports the aetiology of anosacral cutaneous amyloidosis was thought to be a senile change, but half of our patients developed the disease before the age of 60 years. Based on our histopathological findings, apoptosis may be the initial event causing amyloid deposition, although the precise mechanism causing apoptosis needs further investigation. Three patients were found to have diabetes mellitus, but any relationship to anosacral cutaneous amyloidosis is unclear. CONCLUSIONS: No cases of this cutaneous disorder have been reported in the Western literature; there seems to be a racial difference accounting for the disease, although the precise factor is not clarified yet. The disease could easily be misdiagnosed as lichen simplex chronicus, postinflammatory hyperpigmentation or tinea cruris; therefore, a thorough history, a careful physical examination and a skin biopsy is needed to establish a firm diagnosis.

Adult↗
PubMed2000

Virulence of Vibrio parahaemolyticus isolated from cultured small abalone, Haliotis diversicolor supertexta, with withering syndrome.

Outbreaks of mass mortality among cultured small abalone Haliotis diversicolor supertexta with withering syndrome occurred in May and September 1998 in Kao-Hsiung, Taiwan. Bacterial strains CH-1 and B4 were isolated from the haemolymph of the moribund small abalone using tryptic soy agar supplemented with 3% NaCl and/or thiosulphate citrate bile salt sucrose agar. These two strains were characterized and identified as Vibrio parahaemolyticus on the basis of various biochemical tests. The B4 strain and its extracellular products were virulent to small abalone with LD(50) values of 1.6 x 10(5) colony-forming units and 7.58 microg protein g-1 body weight, respectively.

Animals↗
PubMed2000

Salinivibrio costicola subsp. vallismortis subsp. nov., a halotolerant facultative anaerobe from Death Valley, and emended description of Salinivibrio costicola.

Strain DVT, a halotolerant, Gram-negative, facultatively anaerobic bacterium, was isolated from a hypersaline pond located in Death Valley, California. The cells were non-spore-forming, motile, curved rods (1.0-1.8 x 0.5-0.6 microns) and occurred singly, in pairs or rarely in chains. Strain DVT was oxidase-, catalase-, Voges-Proskauer-, amylase-, gelatinase- and lipase-positive and indole-negative. Nitrate, sulfate and fumarate were not used as electron acceptors. Carbohydrates served as energy sources both aerobically and anaerobically. Strain DVT grew optimally at 37 degrees C (temperature range 20-50 degrees C) with 2.5% NaCl (NaCl range 0-12.5%) and pH 7.3 (pH range of 5.5-8.5) in a glucose/yeast extract medium with a doubling time of 20 min (aerobically) or 41 min (anaerobically). The end products of glucose fermentation were ethanol, isobutyrate, propionate, lactate, formate and CO2. Strain DVT was resistant to penicillin, D-cycloserine, streptomycin and tetracycline (200 micrograms ml-1). The G + C content was 50 mol%. 16S rRNA gene sequence analysis indicated that it was closely related to Salinivibrio costicola (97.7%) and this was confirmed by DNA-DNA hybridization (93% relatedness). However, phenotypic characteristics such as halotolerance, gas production, growth at 50 degrees C, antibiotic resistance, sugar-utilization spectrum and phylogenetic signatures are sufficiently different from Salinivibrio costicola to warrant designating strain DVT as a new subspecies of Salinivibrio costicola, Salinivibrio costicola subsp. vallismortis subsp. nov. (= DSM 8285T).

California↗
PubMed2000

Attenuation markers of a candidate dengue type 2 vaccine virus, strain 16681 (PDK-53), are defined by mutations in the 5' noncoding region and nonstructural proteins 1 and 3.

The genome of a candidate dengue type 2 (DEN-2) vaccine virus, strain PDK-53, differs from its DEN-2 16681 parent by nine nucleotides. Using infectious cDNA clones, we constructed 18 recombinant 16681/PDK-53 viruses to analyze four 16681-to-PDK-53 mutations, including 5' noncoding region (5'NC)-57 C-to-T, premembrane (prM)-29 Asp-to-Val (the only mutation that occurs in the structural proteins), nonstructural protein 1 (NS1)-53 Gly-to-Asp, and NS3-250 Glu-to-Val. The viruses were studied for plaque size, growth rate, and temperature sensitivity in LLC-MK(2) cells, growth rate in C6/36 cells, and neurovirulence in newborn mice. All of the viruses replicated to peak titers of 10(7.3) PFU/ml or greater in LLC-MK(2) cells. The crippled replication of PDK-53 virus in C6/36 cells and its attenuation for mice were determined primarily by the 5'NC-57-T and NS1-53-Asp mutations. The temperature sensitivity of PDK-53 virus was attributed to the NS1-53-Asp and NS3-250-Val mutations. The 5'NC-57, NS1-53, and NS3-250 loci all contributed to the small-plaque phenotype of PDK-53 virus. Reversions at two or three of these loci in PDK-53 virus were required to reconstitute the phenotypic characteristics of the parental 16681 virus. The prM-29 locus had little or no effect on viral phenotype. Sequence analyses showed that PDK-53 virus is genetically identical to PDK-45 virus. Restriction of the three major genetic determinants of attenuation markers to nonstructural genomic regions makes the PDK-53 virus genotype attractive for the development of chimeric DEN virus vaccine candidates.

Animals↗