Biomedical subjects

M S Yang

Publications and source records attributed to M S Yang.

At least 37 records · Page 2Linked to original sources

PubMed2001

The treatment of recurrent arthrogrypotic club foot in children by the Ilizarov method. A preliminary report.

Between 1994 and 1997 we used the Ilizarov apparatus to treat 12 recurrent arthrogrypotic club feet in nine patients with a mean age of 5.3 years (3.2 to 7). After a mean of three weeks (two to seven) for correction of the deformity and 1.5 weeks (one to four) for stabilisation in the apparatus, immobilisation in a cast was carried out for a mean of 14 weeks (7 to 24). The mean follow-up period was 35 months (27 to 57). Before operation there were one grade-II (moderate), eight grade-III (severe) and three grade-IV (very severe) club feet, according to the rating system of Dimeglio et al. After operation, all the club feet except one were grade I (benign) with a painless, plantigrade platform. Radiological assessment and functional evaluation confirmed significant improvement. Two complications occurred in one patient, namely, epiphysiolysis of the distal tibia and recurrence of the foot deformity. These results suggest that our proposed modification of the Ilizarov technique is effective in the management of recurrent arthrogrypotic club foot in young children.

Arthrogryposis↗

PubMed2001

Changes in Ca, Cu, Fe, Mg, and Zn contents in mouse brain tissues after prolonged oral ingestion of brick tea liquor containing a high level of Al.

A study was conducted to analyze the regional distribution of Ca, Cu, Fe, Mg, and Zn contents in brain tissues after animals were given liquor of brick tea that contained a high Al content. In 25 normal adult male mice given either water or 0.9% NaCl for 1 mo or 2 mo, the metal concentrations in the serum, liver, frontal cortex, hippocampus, cerebellum, and brain stem were comparable (p > 0.05). When the drinking water was replaced by a 1% brick tea liquor, which contained a high Al content, serum Al concentration was increased significantly 1 mo after the onset of the experiment and remained high at the end of the second month. The level of Al was also elevated in both the cortex and hippocampus at 1 mo after replacing tea for drinking water. In addition to Al, there were a significant increase in hippocampal Zn and a decrease in Cu contents. There was no change in tissue Mg or Fe contents, but there was a significant increase in Ca content in every brain region studied. It was suggested that the increase in Ca might be the result of the effect of other components in tea. Unlike the brain, there was no change in the concentration of any of the metals, including Al, in the liver, which further demonstrated that the changes observed in the brain was specific. The results of the present study confirmed that Al, when given orally in the form of tea, could be absorbed into the bloodstream. The absorbed Al could accumulate in selected brain regions. The presence of Al might also change the tissue content of endogenous trace metals.

Aluminum↗

PubMed2001

Prevalence and correlates of substance use among clinical nurses in Kaohsiung city.

Though substance abuse and its deleterious health sequelae are a serious problem in Taiwan, licit and illicit substance use patterns among nurses are understudied. The purpose of this study was to investigate the prevalence of substance use and to identify its related factors among clinical nurses. A total of 907 registered nurses were recruited for this study via stratified-random sampling from hospitals in Kaohsiung city. Each participant was requested to reply to a structured questionnaire anonymously and a 98.1% response rate was achieved. Prevalence of substance use during the past year was estimated as follows: alcohol drinking (regular use-3.8%); coffee drinking (regular use-44.7%); cigarette smoking (regular use-0.2%); regular use of analgesics 21.1%; regular use of benzodiazepines 1.8%; use of narcotics (ever use-0.7%). Significant factors related to substance use were analyzed by logistic regression. This revealed that for regular alcohol use, the significant factor was a positive attitude toward substance use; for BZD drug use, they were poor mental health, positive attitude toward substance use, being unmarried, and used analgesics; for regular analgesics use, they were work in non-critical care unit, self-perceived poor health status, and BZD drug use. Results generated from this study may act as reference for nursing administration to develop an effective health promotion program of physical and mental health for the clinical nurses.

Adult↗

PubMed2000

Changes in endogenous Zn and Cu distribution in different cytosolic protein fractions in mouse liver after administration of a single sublethal dose of CdCl(2).

The time course of change in tissue Cd, Cu and Zn contents, their distribution in cellular protein fractions as well as the profile of MT gene expression in mouse liver was described over a 7 days period following a single intraperitoneal injection of 2 mg/kg of CdCl(2). The result showed that Cd accumulated rapidly in mouse liver. Between 1 h and 7 days after administration, over 18% of the total Cd administered were found in the liver. Cd administration was also associated with the overexpression of the MT-mRNA. However, the time course of induction was not parallel to the change in tissue Cd content. When separated on a Sephadex G-75 column, majority of Cd was found to bind to the fractions known to contain the metal-binding protein, metallothionein (MT). From day 2 after Cd administration, a small amount of the metal was also found associated with the high molecular weight (HMW) proteins. In addition to Cd, tissue Zn content was affected most during the entire study. There was a significant decrease in tissue Zn content during the initial 8 h but tissue Zn content increased significantly throughout the following 6 days. At 1-7 days, majority of Zn was associated with the HMW protein fraction. Although there was no significant change in total tissue Cu content, distribution of Cu in different protein fractions was detected. While in control animals, Cu was mainly associated with the HMW proteins, some was found in the MT fraction on the second day. On the 7th day, Cu distribution had deteriorated. Together with changes seen in Cd, the results might suggest that injury had occurred in the tissue at this time. The results of the present study showed that Cd caused a change in subcellular distribution of tissue endogenous metals, which might reflect alteration of cellular functional activities.

Animals↗

PubMed2000

Expression of glucose oxidase by using recombinant yeast.

The glucose oxidase gene (GO) of Aspergillus niger was cloned into the yeast shuttle vector YEp352 with combinations of various promoters and terminators, and then used to transform Saccharomyces cerevisiae. Expressed GO was successfully secreted into culture medium due to the presence of the intrinsic signal peptide of GO. Four different promoters fused to GO were tested: bidirectional galactose dehydrogenase 1 and 10 (GAL1, GAL10) promoters, glyceraldehyde-3-phosphate dehydrogenase (GPD) promoter and an yeast hybrid ADH2-GPD promoter consisting of alcohol dehydrogenase II (ADH2) and GPD promoter. The intrinsic terminator of GO as well as the GAL7 terminator were also compared for better production of GO. Deletion of most of the terminating region from GO yielded only a slight amount of GO while the presence of either terminator greatly increased GO production. The GAL10 promoter produced the least amount of GO, GAL1 and GPD promoters were moderate, and the ADH2-GPD hybrid promoter was the best among all tested. However, the hybrid promoter was tightly regulated by the presence of an excess amount of either glucose or ethanol, and it appeared that 2% glucose and 1. 5% ethanol supplement was the best concentration for GO production. It was possible to produce 260 IU ml(-1) of GO, an equivalent of 5 g l(-1), under the presence of 2% glucose and 1.5% ethanol. UV mutagenesis of a recombinant S. cerevisiae was also applied and it further increased the yield of GO to 460 IU ml(-1) under the presence of 2% glucose and 1.5% ethanol without any changes in cell growth. Corn steep liquor which is commonly used in bioindustry is a good alternative substrate for high priced glucose for the hybrid promoter and suggests a cost effective means for commercial mass production of GO using recombinant yeast.

Biotechnology↗

PubMed2000

Protective mechanism of metallothionein against copper-1, 10-phenanthroline induced DNA cleavage.

Metallothionein (MT) has been shown to protect DNA against cleavage induced by a variety of mutagenic agents. The mechanism has been attributed to its ability to either chelate transitional metals that participate in the Fenton reaction, or scavenge free radicals by means of the abundant cystenyl residues of the proteins. In the present study, the protective action of MT against DNA cleavage by the copper-1,10-phenanthroline [(OP)(2)Cu(+)] complex was studied in situ. At 0.1 microM, MT inhibited the (OP)(2)Cu(+) induced DNA cleavage by about 50% (IC(50) approximately 0.1 microM). At 2.5 microM, the cleavage activity was completely inhibited. Similar to MT, cysteine can protect against DNA cleavage by (OP)(2)Cu(+) (IC(50) of approximately 3 mM), however, its action was 1500-fold less efficient than MT. The combined action of MT and cysteine was additive. Reduced glutathione (1 and 10 mM) did not protect the (OP)(2)Cu(+) induced DNA cleavage. Sodium azide could inhibit the cleavage only at high concentrations (IC(40) approximately 25 mM). Spectrophotometric analysis showed that MT can inhibit the formation of the DNA[(OP)(2)Cu(+)] complex possibly by chelating Cu. It can also cause a dissociation of the complex after it was formed. In the later case, the mechanism through which MT protects against the DNA cleavage might occur when MT fitted in closely with the complex, competing with the hydroxyl groups of the nucleotides base for Cu, which, in turn, terminate the Fenton-like free radical reaction.

DNA↗

PubMed2000

Changes in expression of N-methyl-D-aspartate receptor subunits in the rat neostriatum after a single dose of antisense oligonucleotide specific for N-methyl-D-aspartate receptor 1 subunit.

In order to investigate the process of gene expression of N-methyl-D-aspartate glutamate receptor (NMDAR) subunits in the rat neostriatum and how this relates to motor behaviors, a single dose of antisense phosphodiester oligodeoxynucleotide specific for NMDAR1 was unilaterally applied in the neostriatum in a stereotaxic apparatus. After one day of antisense treatment, ipsilateral rotation behaviors that were induced by apomorphine were found in the treated animals. Reductions in the levels of expression of NMDAR1 and NMDAR2A messenger RNAs (NMDAR1: 20.6%; NMDAR2A: 19.7%) were found in the antisense-treated striatal tissues by reverse transcriptase-polymerase chain reaction. There was no change in the levels of NMDAR2B, NMDAR2C and NMDAR2D messenger RNAs. After two days, western blotting experiments showed that there were decreases in the levels of expression of NMDAR1 (decreased 27.6%) and NMDAR2A (decreased 19.2%) proteins in the NMDAR1 antisense-treated striatal tissues. In addition, NMDAR1 immunoreactivity was found to decrease in intensity in the NMDAR1 antisense-treated neostriatum. At the cellular level, the intensity of NMDAR1 immunoreactivity in perikarya of presumed medium spiny neurons was found to decrease. These results indicate that a single dose of NMDAR1 antisense modifies the expression of NMDAR1 messenger RNA and protein in neurons in the neostriatum. The modification in the expression of NMDAR1 has differential effects in the expression of NMDAR2 subunits. Gene expression of the native NMDAR subunits is likely to be a dynamic process. The change in gene expression of the NMDAR subunits in the neostriatum may have a profound effect on the motor behaviors of rats.

Animals↗

PubMed2000

Correlated risk factors for suicidal ideation in aboriginal Southern Taiwanese women of childbearing age.

Suicide and non-accidental poisoning are two important causes of death of female aborigines in Taiwan. The purpose of this study was to estimate the prevalence of suicidal ideation and then to identify factors relating to this for female aborigines of childbearing age. Using stratified random sampling 212 female aborigines, aged between 20 and 49, were recruited into this study. Participants were interviewed at their homes by trained interviewers who used a structured questionnaire. The Suicidal Ideation Screening Questionnaire (SIS-Q) was used to help predict which participants would be more likely to have suicidal ideation. The prevalence rate of suicidal ideation within the previous 12 months was 20.3% (95% CI 14.9-25.7%). Significant related factors of suicidal ideation, which were analyzed by multiple logistic regression, revealed that women suffering depressive mood, living within a extended family, and perceiving poor health status were more likely to have suicidal ideation. Results generated from this study may be used, in primary care, for guidance as to how to prevent suicide. Outreach community programs incorporating a valid and sensitive screening instrument, such as the SIS-Q, should be implemented to help prevent suicides in aboriginal communities.

Adult↗

PubMed2000

Increased expression of cyclooxygenase-2 protein in human gastric carcinoma.

Gastric adenocarcinoma is one of the most common malignancies in the world, and yet little is known about its molecular process of development and progression. Recent studies have suggested that ingestion of nonsteroid anti-inflammatory drugs reduces the risk of colon cancer, presumably by inhibiting the cyclooxygenase (COX) enzyme. COX-2, one isoform of the COX enzyme, is the rate-limiting enzyme in prostaglandin synthesis, and the function of this enzyme is thought to relate to inflammatory processes and carcinogenesis. To understand the role of COX enzyme in gastric cancer, we measured COX-2 expression in 104 human gastric carcinoma tissues by immunohistochemical analysis. We obtained tissue specimens from 104 surgically resected gastric adenocarcinoma patients. We performed immunohistochemical stain for human COX-2 with polyclonal antibody in gastric carcinoma. After curative resection and extensive lymph node dissection, all patients received adjuvant chemotherapy containing 5-fluorouracil. Expression of COX-2 showed cytoplasmic staining, not only in cancer cells but also in precancerous lesions such as metaplastic and adenomatous cells. We confirmed up-regulation of COX-2 in gastric cancer tissues compared with normal paired mucosa using Western blot analysis. There was no correlation between clinicopathological characteristics of gastric cancer patients and intensity of COX-2 protein expression. This study indicates that COX-2 protein over-expression may contribute to an early event of gastric cancer development, and it further suggests that selective inhibition of COX-2 may provide a chemopreventive effect against gastric carcinogenesis.

Adenocarcinoma↗

PubMed1999

Signalling pathway leading to an activation of mitogen-activated protein kinase by stimulating M3 muscarinic receptor.

The signalling pathway leading to an activation of mitogen-activated protein (MAP) kinase subtypes Erk-1 and -2 upon stimulation of muscarinic receptor with carbachol in human neuroblastoma SK-N-BE2(C) cells was investigated. Carbachol activated Erk-1/-2 by stimulating M3 muscarinic receptor, as determined by specific antagonists for individual muscarinic receptors. The activation of Erk-1/-2 by carbachol was blocked by the inhibition or down-regulation of protein kinase C (PKC). Among the multiple PKC isoforms expressed in SK-N-BE2(C) cells, only PKCepsilon was activated by the treatment of carbachol, and selective down-regulation of PKCepsilon was sufficient to block Erk-1/-2 activation. Carbachol treatment induced activation of the serine/threonine protein kinase Raf, and an inhibition of Raf blocked Erk-1/-2 activation. Ectopic expression of inhibitory small GTPase Ras, RasN17, blocked the carbachol-induced Raf activation without affecting the activation of PKCepsilon, while the inhibition of PKC blocked the Raf activation. Thus, these results suggest that carbachol-induced activation of PKCepsilon mediates Erk-1/-2 activation by a sequential activation of Ras, Raf and MAP kinase kinase.

Calcium-Calmodulin-Dependent Protein Kinases↗

PubMed1999

Betel quid chewing and risk of adverse pregnancy outcomes among aborigines in southern Taiwan.

It is known that substance use is associated with increased risk of adverse pregnancy, outcomes. The aims of this study were to estimate the prevalence of alcohol, cigarette, betel quid and drug use during pregnancy and to assess the risk of adverse effects of betel quid chewing on pregnancy outcomes in aboriginal women in southern Taiwan. The study population included 62 women with adverse pregnancy outcomes and 124 age-matched women. Subjects were interviewed at their homes by trained interviewers using a structure questionnaire. Prevalences of various substance use in aborigines with adverse pregnancy outcomes were estimated as follows: alcohol, 43.6%; smoking, 14.5%; betel quid chewing, 43.6% and over-the-counter drug use, 8.1%; whereas in the comparison group it was alcohol, 38.7%; smoking, 8.1%; betel quid chewing, 28.2% and none used drugs. Univariate analysis revealed that adverse pregnancy outcomes were associated with maternal betel quid chewing, maternal illness during pregnancy, and the number of pregnancies (gravidity) experienced. After adjusting for maternal illness and number of previous pregnancies covariates, the prevalence of adverse pregnancy outcome was computed to be 2.8-fold higher among betel quid chewing women as compared to non-chewers (AOR=2.8, 95% CI=1.2-6.8). Among the aboriginal women, prenatal care is essential not only for routine care, but also to focus health education on the harmful effects of substance use, especially betel quid use during pregnancy.

Adult↗

PubMed1999

Hemistepsins with cytotoxic activity from Hemisteptia lyrata.

Two sesquiterpene lactones were isolated from Hemisteptia lyrata Bunge (Compositae). Their structures were elucidated by spectroscopic methods as recently known hemistepsin and the new 6-O-(2-methylpropenoyl)-3-hydroxy-4(15), 10(14), 11(13)-guaiatrien-12,8-olide. The two hemistepsin derivatives were examined for their in vitro cytotoxic activity against human cell lines such as UACC 62, HCT 15, UO-31, PC-3 and A549. Growth inhibitory property was determined by in vitro treatment of the respective cell lines using the sulforhodamine B assay (SRB). Both compounds exhibited significant cytotoxic activity (IC50 < 4.3 micrograms/ml) on all five human cell lines tested.

Antineoplastic Agents, Phytogenic↗

PubMed1999

Genomic plasticity in natural populations of Bordetella pertussis.

We determined the genomic organization of 14 clinical strains of Bordetella pertussis isolated over an 18-month period in Alberta, Canada. The maps of these 14 strains, while demonstrating general similarity of gene order, display a number of examples of genomic rearrangements in the form of large chromosomal inversions.

Bordetella pertussis↗

PubMed1999

[The relationships between the elderly loneliness and its factors of personal attributes, perceived health status and social support].

The purpose of this study were to investigate the level of loneliness in elderly people and to explore relationships between loneliness and personal attributes, perceived health status and social support. Purposive sampling was used to recruit clients over 65 years of age from an outpatient department of the Municipal hospital and a senior citizen center in Kaohsiung city, and totaled 120 elderly people had participated in this study. Data were collected by a structured questionnaire which included the UCLA Loneliness Scale, Perceived Health Status Scale, and Social Support Scale. The results revealed the following: 1. The mean score was 38.4 (SD 9.6); level of loneliness in elderly people was moderate, and people who were male, uneducated, unsatisfied with living circumstance, unsatisfied with economic situation, and not attending social groups were more likely to have higher scores of loneliness. 2. There was a significantly negative correlation between perceived health status, mental health, health satisfaction, social support, supportive satisfaction and loneliness. 3. The results of multiple regression found that family interactions, attending social groups and supportive satisfaction were the significant predicting variables of loneliness, and "supportive satisfaction" was the most powerful predictor. Results generated from this study may act as references for mental health care for elderly people.

Aged↗

PubMed1998

Determination of endogenous trace metal contents in various mouse brain regions after prolonged oral administration of aluminum chloride.

Aluminum (Al) has been said to associate with the Alzheimer's-like neurodegeneration in humans. One of the proposed mechanisms for the action of Al is that excess Al might interfere with trace metal metabolism. In this study, the levels of Ca, Mg, Cu, and Zn in blood, liver, and different regions of the brain (separated into the cortex, hippocampus, cerebellum, and brainstem) were measured in mice after daily oral administration of AICI3 (100 mg/kg body weight) for 2 mo. It was found that upon prolonged oral administration of AI, serum Al level was elevated significantly. There was no marked change in serum Ca, Mg, Zn, or Cu content. In the liver, Al content was not increased but there was a significant elevation in Cu and Zn content compared to control animals, probably due to the prolonged administration of the acidic salt solution. In brain, there was a significant twofold increase in Al in the hippocampus and a significant decrease in Al in the cortex. In addition to regional changes in AI content, Zn content in the hippocampus and increased Cu content in the hippocampus, cortex, and brainstem were significantly reduced. Data demonstrated that Al could alter Zn and Cu homeostasis in selected brain regions. The possible relation between Al and neuronal cell injury was discussed.

Administration, Oral↗

PubMed1998

Cloning and analysis of the Epstein-Barr virus glycoprotein 350 genes.

Membrane glycoprotein 350 (gp350) of the Epstein-Barr virus (EBV) is considered as a major target for vaccine development, since the gp350 has been identified as the virus' mediator for receptor interaction and as an inducer of specific in vitro virus-neutralizing antibodies. In an initial attempt to develop an effective DNA vaccine against an EBV infection, gp350 genes were isolated from SNU-20 and SNU-1103 which are the EBV-infected lymphoblastoid cell lines established in Korea. In addition, the nucleotide sequences of the gp350 genes were determined and compared with those of other EBV strains such as B95-8, P3HR-1/AG876 and M81. Sequence analysis showed that similar high degrees of homology between 2 EBV strains derived from African Burkitt's lymphoma, P3HR-1 and AG876, was shown between the gp350 genes isolated from 2 EBV-infected lymphoblastoid cell lines established in Korea. Furthermore, these 2 Korean and 2 African strains displayed nearly identical patterns of sequence variations from B95-8. In addition, the sequence of the isolated gp350 genes, which have been reported to be associated with the biology of EBV infection, is analyzed.

Amino Acid Sequence↗

PubMed1998

Determination of metallothionein content in hepatoma cells by differential pulse polarography.

Differential pulse polarography (DPP) was applied to measure metallothionein (MT) content in the RH-35 rat hepatoma cell. The method was sensitive in measuring MT at nanogram concentrations. The MT measurement was not interfered by small molecular weight proteins. Cellular MT content increased upon incubated in medium containing different concentrations of CdCl2 or ZnCl2. The increase was concentration-dependent. In the case of CdCl2, significant increase in cellular MT content was observed at a level as low as 0.18 mg/l. The change in MT occurred when there was no significant change in cell viability or cellular protein content. The concentration of ZnCl2 needed to induce the same amount of MT as that with 0.18 mg/l CdCl2 was 12 mg/l. At high concentrations (> 12 mg/l), ZnCl2 also caused an increase in cellular protein content. Therefore, when calculation was based on cellular protein content, ZnCl2 did not caused further increase in MT. L-ascorbic caused significant increase in cellular MT content when it was presented at levels above 100 mg/l but not at 50 mg/l. The effect of L-ascorbic acid on MT induction was not dose-dependent. At 150 mg/l, the amount of MT induced was not different from that with 100 mg/l. Thus, L-ascorbic might not directly influence cellular MT content. Cysteine at 4 and 40 mg/l did not increase cellular MT content. The results of this study showed that cellular MT content could be measured by DPP. Our finding that CdCl2 at sub-lethal concentrations can effectively induce MT suggests that MT may serve as an early warning signal prior to serve as an early warning signal prior to the occurrence of cell death.

Animals↗

PubMed1998

Protein kinase C regulates chondrogenesis of mesenchymes via mitogen-activated protein kinase signaling.

A possible regulatory mechanism of protein kinase C (PKC) in the chondrogenesis of chick limb bud mesenchymes has been investigated. Inhibition or down-regulation of PKC resulted in the activation of a mitogen-activated protein kinase subtype Erk-1 and the inhibition of chondrogenesis. On the other hand, inhibition of Erk-1 with PD98059 enhanced chondrogenesis and relieved PKC-induced blockage of chondrogenesis. Erk-1 inhibition, however, did not affect expression and subcellular distribution of PKC isoforms expressed in mesenchymes nor cell proliferation. The results suggest that PKC regulates chondrogenesis by modulating Erk-1 activity. Inhibition or depletion of PKC inhibited proliferation of chondrogenic competent cells, and Erk-1 inhibition did not affect PKC modulation of cell proliferation. However, PKC-induced modulation of expression of cell adhesion molecules involved in precartilage condensation was reversed by the inhibition of Erk-1. Expression of N-cadherin was detected at the early period of chondrogenesis. Inhibition or depletion of PKC induced sustained expression of N-cadherin, and Erk-1 inhibition blocked the effects of PKC modulation. The expression of integrin alpha5 beta1 and fibronectin was found to be increased transiently during chondrogenesis. Depletion or inhibition of PKC caused a continuous increase of the expression of these molecules throughout the culture period, and Erk-1 inhibition abolished the modulating effects of PKC. Because reduction of the examined cell adhesion molecule expression is a prerequisite for the progression of chondrogenesis after cell condensation, our results indicate that PKC regulates chondrogenesis by modulating expression of these molecules via Erk-1 signaling.

Animals↗