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Biomedical subjects

Y C Wang

Publications and source records attributed to Y C Wang.

At least 55 records · Page 3Linked to original sources

Effect of heat treatments on the meltability of cheeses.

The effect of heat treatments on the meltability of cheese was investigated. Cheddar cheeses of different composition and low-moisture, part-skim Mozzarella cheese were studied at 1, 3, 6, and 12 wk of aging. Cheese samples were heated to 60 degrees C and held for 0, 10, and 20 min before allowing the melted cheese to flow. Mean meltabilities, over all ages, of both Cheddar and Mozzarella cheeses decreased significantly as holding time increased. Meltability of young cheese was scarcely affected by the holding time, in sharp contrast to that of the old cheese where increasing the holding time greatly reduced meltability.

Cheese↗

Cerebral intraventricular hemorrhage caused by a large cerebral arteriovenous malformation at 31 years after diagnosis.

Cerebral arteriovenous malformation (AVM) has an overall 2% to 4% annual risk of hemorrhage. The annual risk of hemorrhage does not decrease with age. However, the natural history of non-operative AVM is difficult to follow up consistently for more than 30 years. In this report, we present a case with a large cerebral AVM which developed a major bleeding causing intraventricular hemorrhage (IVH) 31 years after the diagnosis. A male patient was proved to have a cerebral AVM in the right corpus callosum by cerebral angiography at ages 20 and 28. He was found losing consciousness due to rupture of AVM with IVH at age 51. A small cerebral aneurysm and a dilated vein (aneurysm) of Galen were noted also. A craniotomy with removal of the hematoma and microsurgical resection of the AVM was performed immediately, and the patient regained normal respiration and consciousness about 2 months and 7 months after craniotomy, respectively. We recommend that neurosurgeons should play active roles in encouraging young patients with large AVMs to receive microsurgical resection.

Age Factors↗

Body weight, serum uric acid and lipid profile one year after spinal cord injury.

BACKGROUND: Survey of the serum lipoprotein profile, uric acid levels and body weight in Chinese patients with spinal cord injury (SCI) one year after injury, and to report the data of patients with SCI at different levels. METHODS: Seventy-seven Chinese patients with SCI categorized into cervical SCI, thoracic SCI, and lumbar SCI groups were enrolled in the study. The serum uric acid and lipoprotein profiles of these patients were evaluated one year after injury. All of the data in those different groups of SCI patients were compared with normal levels. Body weight before and after injury were also evaluated. RESULTS: Serum uric acid was within normal limits in all three SCI groups. A similar lower in serum high density lipoprotein cholesterol (HDL-C) level was observed in all three groups of SCI patients. Higher serum levels were observed in total cholesterol (TC) in the lumbar SCI group, triglyceride and very low density lipoprotein cholesterol in the thoracic and lumbar SCI group, and TC/HDL-C ratio in all three SCI groups. Decrease of body weight were noted in cervical and thoracic SCI patients. CONCLUSION: Further long-term follow up was necessary to determine the serum lipid and body weight change in patients with SCI at different levels.

Adult↗

Candida vertebral osteomyelitis: a case report and review of the literature.

Candida species are low virulence organisms which inhabit the skin and mucous membranes of most individuals. There has been increasing incidence of disseminated and deep-seated Candida infections owing to the increasing number of immune compromised hosts. However, the Candida species are still rarely suggested as causative pathogens of vertebral osteomyelitis. We present a 51-year-old man with neck pain and cervical radiculopathy. Three months prior to visiting our hospital, he had undergone a urological operation which was complicated by a urinary tract infection. Magnetic resonance imaging and X-rays showed erosion of the body of the 5th cervical spine and collapse of the C5-C6 disc. After open debridement, tissue pathology results revealed Candida infection. Clinical stability was achieved during the 6-month follow-up period with a combination of amphotericin B and posterior fixation method. We reviewed the literature and found a high rate of surgical intervention for patients suggested of having Candida vertebral osteomyelitis. However, the surgical intervention may not be necessary. Early diagnosis using noninvasive percutaneous needle biopsy may help reduce the incidence of delayed treatment.

Candidiasis↗

[Separation of DNA fragments from halobacterium halobium by capillary electrophoresis with non-gel sieving media].

The optimum electrophoresis separation conditions of Lambda DNA/EcoR I + Hind III fragments were investigated using the capillary column DB-1 coated with polysiloxane. When hydroxyethylcellulose (HEC, 1.0%, mass percentage) was used as the only non-gel sieving medium solution, some Lambda DNA fragments could not be separated. After polyvinylpyrrolidone (PVP, 2%, mass percentage) being added into the medium solution, PVP and HEC formed a network colloidal solution in buffer, and changed the network hole size of sieving media. In addition, the results showed that PVP could restrain the adsorption of capillary to DNA, reduced electroosmotic flow, and improved the selectivity of separation. For the first time, all fragments of Lambda DNA marker was separated completely under the same condition of mixed sieving medium solution. The method was applied to separate two groups of DNA fragments of halobacterium halobium, and the base pair number was conjectured.

Cellulose↗

[Efficacy of ablendazole emulsion in treatment of 212 patients with cystic echinococcosis].

OBJECTIVE: To verify the efficacy of abendazole emulsion, a new formulation of abendazole, in treatment of human cystic echinococcosis. METHODS: 212 patients with liver cystic echinococcosis were treated orally with albendazole emulsion at a daily dose of 10 mg/kg or 12.5 mg/kg for 3 to 12 months or over one year. The therapeutic efficacy was mainly evaluated by image feature examined with B ultrasound examination, a short-term efficacy at the completion of treatment and a long-term efficacy followed-up for 1-4 years. RESULTS: In 212 patients treated with albendazole emulsion at a daily dose of 10 mg/kg and 12.5 mg/kg, the average cure rate, improved rate and the rate of no avail were 74.5%, 99.1% and 0.9% respectively after termination of the treatment, and the average long-term rates were 83.1%, 89.3% and 0.6% respectively. Recurrence occurred in 18 patients(10.2%). The results indicated that the best efficacy was seen in patients treated with albendazole 12.5 mg/kg daily for 9 months. Better response was also found when the recurrent patients were re-treated with albendazole. CONCLUSION: The efficacy of albendazole emulsion on patients with liver cystic echinococcosis is much better than that of albendazole tablet or capsule and mebendazole. Meanwhile, the efficacy of albendazole emulsion is stable with less adverse effects. The results suggest that albendazole emulsion could be the drug of choice for treatment of cystic hydatid disease.

Albendazole↗

Antagonism between members of the CNC-bZIP family and the immediate-early protein IE2 of human cytomegalovirus.

The HCMV IE2 protein negatively autoregulates its own expression as well as represses the transactivation activity of p53. Using the repression domain of IE2 as bait in the yeast two-hybrid system, Nrf1 and Nrf2, members of the CNC-bZIP family, were found to be IE2-interacting proteins. Residues 331-448 encompassing the DNA-binding and the dimerization domains of Nrf1 are sufficient for the interaction. The interaction was further confirmed in vitro by a glutathione S-transferase pull-down assay and in vivo by co-immunoprecipitation. In transient transfection studies, transcription driven by six copies of an NF-E2 site or by chimeric proteins between the DNA-binding domain of LexA and members of the CNC-bZIP family is repressed by IE2. Importantly, the DNA binding activity of the Nrf1/MafK heterodimer is not impeded by IE2. In a parallel study, CNC-bZIP factors attenuate the negative autoregulation of IE2. The attenuation could be explained by the finding that Nrf1 functions alone and synergistically with its heterodimerization partner, MafK, in inhibiting the DNA binding activity of IE2. Taken together, these results demonstrate the existence of antagonism between members of the CNC-bZIP family and IE2.

Cell Line↗

Rapid diagnosis and quantification of herpes simplex virus with a green fluorescent protein reporter system.

A genetically modified cell line (Vero-ICP10-EGFP) was constructed for detection of herpes simplex virus (HSV) by a simple, rapid and direct method. The cell line was developed by stable transfection of Vero cell with a plasmid encoding the green fluorescent protein (GFP) driven by the promoter of the HSV-2 ICP10 gene. As early as 6 h after infection with HSV, fluorescence-emitting cells can be observed under a fluorescence microscope. A single infected cell emitting fluorescence can be observed with soft agar overlay by inverted fluorescence microscopy. No induction of detectable fluorescence was seen following infections with human cytomegalovirus (HCMV), varicella zoster virus (VZV), coxsackievirus A16 and enterovirus 71. Analysis by flow cytometry also demonstrated that intensity of the triggered fluorescence is proportional to the titer of HSV inoculated. Taken together, this novel GFP reporter system could become a useful means for rapid detection and quantification of HSV in clinical specimens.

Animals↗

Inhibition of farnesyltransferase with A-176120, a novel and potent farnesyl pyrophosphate analogue.

Farnesylation of Ras is required for its transforming activity in human cancer and the reaction is catalysed by the enzyme farnesyltransferase. Recently, we discovered a novel chemical series of potent farnesyl pyrophosphate (FPP) analogues which selectively inhibited farnesyltransferase. Our most potent compound to date in this series, A-176120, selectively inhibited farnesyltransferase activity (IC(50) 1.2+/-0.3 nM) over the closely related enzymes geranylgeranyltransferase I (GGTaseI) (IC(50) 423+/-1.8 nM), geranylgeranyltransferase II (GGTaseII) (IC(50) 3000 nM) and squalene synthase (SSase) (IC(50)>10000 nM). A-176120 inhibited ras processing in H-ras-transformed NIH3T3 cells and HCT116 K-ras-mutated cells (ED(50) 1.6 and 0.5 microM, respectively). The anti-angiogenic potential of A-176120 was demonstrated by a decrease in Ras processing, cell proliferation and capillary structure formation of human umbilical vein endothelial cells (HUVEC), and a decrease in the secretion of vascular endothelial growth factor (VEGF) from HCT116 cells. In vivo, A-176120 reduced H-ras NIH3T3 tumour growth and extended the lifespan of nude mice inoculated with H- or K-ras-transformed NIH3T3 cells. A-176120 also had an additive effect in combination with cyclophosphamide in nude mice inoculated with K-ras NIH3T3 transformed cells. Overall, our results demonstrate that A-176120 is a potent FPP mimetic with both antitumour and anti-angiogenic properties.

Alkyl and Aryl Transferases↗

Histopathological examination of chemo-sympathectomy in cats.

In recent decades, there has been an increase in both the number of sympathectomy techniques, as well as the surgical findings of sympathetic anatomy. Currently the advanced technique of C-arm guided percutaneous thoracic chemo-sympathectomy is widely used for the treatment of palmar hyperhidrosis. However, a better understanding of chemical agents in sympathectomy is required. In this study, chemo-sympathectomy was performed in cats, using alcohol, glycerol and various concentrations of phenol, to determine the chronic neurotoxic effects of these chemical agents on the stellate ganglia. The stellate ganglia of 24 cats were exposed under endotracheal general anesthesia, then injected with about 0.02 ml of absolute alcohol, glycerol and phenol (10%, 25%, 50%, and 75% concentration) solutions, respectively. The stellate ganglia were taken for histological examination three weeks after the chemical injection. The results showed that the degenerative changes in the cytoplasm and nucleus of ganglionic cells and intercellular tissue were moderate and relatively moderate after the injection of alcohol and glycerol, respectively. Meanwhile, the stellate ganglia revealed mild, relatively moderate, serious and extremely serious degeneration after injection of 10%, 25%, 50%, and 75% phenol, respectively. In conclusion, we recommend a high concentration of phenol, in the least volume, as a chemical agent for clinical injection in the upper thoracic sympathetic ganglion.

Animals↗

Competition with TATA box-binding protein for binding to the TATA box implicated in human cytomegalovirus IE2-mediated transcriptional repression of cellular promoters.

The human cytomegalovirus IE2 is a sequence-specific DNA-binding protein. A consensus IE2-binding site (IBS) contains two copies of the dinucleotide CG separated by 10 not well-conserved but AT-rich nucleotides. In this report, we demonstrated that the TATA box of the insulin-like growth factor binding protein 4 (IGFBP4) promoter is embedded in an IBS. In a transient transfection study, IE2-mediated repression of a reporter driven either by a synthetic promoter containing the IGFBP4 TATA/IBS element or by the native IGFBP4 promoter was dependent on the intactness of the IBS. Competition with TBP for binding to the IGFBP4 TATA/IBS element may underlie the mechanism for the IE2-mediated repression, because IE2 and TATA box-binding protein (TBP) binding to the IGFBP4 TATA/IBS element are mutually elusive. Moreover, the TATA boxes of several other genes, including ADA and CPH-70, are likewise confined in IBS-like sequences. The IE2 interacts with those TATA/IBS elements in vitro and inhibits transcription driven by them in vivo, supporting the idea that competitive inhibition of TBP binding to the TATA box represents a novel mechanism exploited by IE2 to repress cellular gene expression.

Binding Sites↗

Two-chain high molecular weight kininogen induces endothelial cell apoptosis and inhibits angiogenesis: partial activity within domain 5.

We previously reported that the binding of two-chain high molecular weight kininogen (HKa) to endothelial cells may occur through interactions with endothelial urokinase receptors. Since the binding of urokinase to urokinase receptors activates signaling responses and may stimulate mitogenesis, we assessed the effect of HKa binding on endothelial cell proliferation. Unexpectedly, HKa inhibited proliferation in response to several growth factors, with 50% inhibition caused by approximately 10 nM HKa. This activity was Zn(2+) dependent and not shared by either single-chain high molecular weight kininogen (HK) or low molecular weight kininogen. HKa selectively inhibited the proliferation of human umbilical vein and dermal microvascular endothelial cells, but did not affect that of umbilical vein or human aortic smooth muscle cells, trophoblasts, fibroblasts, or carcinoma cells. Inhibition of endothelial proliferation by HKa was associated with endothelial cell apoptosis and unaffected by antibodies that block the binding of HK or HKa to any of their known endothelial receptors. Recombinant HK domain 5 displayed activity similar to that of HKa. In vivo, HKa inhibited neovascularization of subcutaneously implanted Matrigel plugs, as well as rat corneal angiogenesis. These results demonstrate that HKa is a novel inhibitor of angiogenesis, whose activity is dependent on the unique conformation of the two-chain molecule.

Amino Acid Sequence↗

Association study of a cannabinoid receptor gene (CNR1) polymorphism and schizophrenia.

Cannabis can induce schizophrenic-like symptoms in healthy individuals. A principal active ingredient of cannabis, delta-9-tetrahydrocannabinol, acts in the brain on a specific receptor, termed the cannabinoid receptor 1 (CNR1). The human gene for CNR1 is mapped to chromosome 6q14-15, and linkage studies have produced evidence for a schizophrenia-susceptibility locus in this region. To explore a possible role for CNR1 in the pathogenesis of schizophrenic disorders, we used an association study to genotype the CNR1 polymorphism for 127 schizophrenic patients and 146 control subjects. The results demonstrate no association between CNR1 genotypes and schizophrenic disorders (P = 0.409), with these negative findings suggesting that, for Chinese populations, the (AAT)n triplet repeat in the promoter region of the CNR1 gene is not directly involved in the pathogenesis of schizophrenic disorders.

Adult↗

Lack of evidence of association of p21WAF1/CIP1 polymorphism with lung cancer susceptibility and prognosis in Taiwan.

An association between the Arg allele of the p21WAF1/CIP1 codon 31 polymorphism and lung cancer has been reported. However, the genotype distribution of the p21 codon 31 polymorphism, as well as the association of this polymorphism with lung cancer risk and prognosis, remain undefined in the Taiwanese population. Therefore, we investigated the genotype distribution of the p21 codon 31 polymorphism in 155 lung cancer patients and 189 non-cancer controls. The genotype frequencies in the Taiwanese non-cancer controls were 0.51 (Ser) and 0.49 (Arg). Chi2 analysis indicated significant differences in Taiwanese genotype distribution of p21 from those reported for Swedes (P=0.001), Caucasians (P=0.001), Indians (P=0.001), and African-Americans (P=0.001). However, our data did not demonstrate an association of the Arg allele of the p21 polymorphism with lung cancer risk in Taiwan. Lung cancer patients with Ser/Arg and Arg/Arg genotypes were at a nonsignificant 1.15-fold increased risk of lung cancer when compared to individuals with the Ser/Ser genotype (95%CI, 0.70-1.86). In addition, although p21 is a downstream target of p53, we found no significant correlation of the p21 polymorphism with the p53 polymorphism and p53 gene mutation in lung cancer patients. We further investigated the association of the p21 polymorphism with prognosis in 154 lung cancer patients. Patients with the Ser/Ser genotype tended to have a poorer prognosis than those with the Ser/Arg and Arg/Arg genotypes (P=0.097, by the log rank test). Our data suggest that the p21 codon 31 polymorphism may not play a significant role in cancer susceptibility and the prognosis of lung cancer patients in Taiwan.

Adenocarcinoma↗

No evidence for association of alpha 1a adrenoceptor gene polymorphism and clozapine-induced urinary incontinence.

Clozapine is an effective atypical antipsychotic that has high affinity for many neurotransmitter receptors. Among the adverse effects of clozapine, urinary incontinence is commonly found and is suggested to be caused by alpha-adrenergic blockade. We tested the hypothesis that clozapine-induced urinary incontinence is related to a genetic variant of the alpha(1a)-adrenoceptor. We also tested whether the alpha(1a)-receptor gene confers susceptibility to schizophrenic disorders. Our result indicated that the alpha(1a)-adrenoceptor gene polymorphism investigated plays no major role in the pathogenesis of schizophrenia or in clozapine-induced urinary incontinence. Considering the superior effects of clozapine and its potent adrenergic antagonistic effects, it is of interest to investigate the association between this polymorphism and the treatment response.

Adult↗

Comparison testing of current (PPD-S1) and proposed (PPD-S2) reference tuberculin standards.

Since 1951, the tuberculin PPD-S1 has been used to standardize commercial PPD reagents and perform special tuberculin surveys. PPD-S1 is now in short supply and a new standard (PPD-S2) has been manufactured. To determine if PPD-S2 is equivalent and can replace PPD-S1, we conducted a double-blind clinical trial. Between May 14 and October 28, 1997, 69 subjects with a history of culture-proven tuberculosis (TB patients) and 1,189 subjects with a very low risk for TB infection were enrolled, received four skin tests (with PPD-S1, PPD-S2, and one each of the commercially available PPDs), and had reactions measured by two trained observers. Among the TB patients, we found statistically indistinguishable immunogenicity (mean reaction size +/- standard deviation): 15.6 +/- 6.6 mm for PPD-S1 and 14.8 +/- 5.6 mm for PPD-S2. Among low-risk subjects, the tests had equally high specificities (PPD-S1, 98.7% and PPD-S2, 98. 5%), using a 10-mm cutoff. The number of discordant (negative versus positive) interpretations for PPD-S2, assuming that low-risk subjects who had a >/= 10 mm reaction to PPD-S1 were truly infected, was low (0.5%) and indistinguishable from the rate of discordant interpretations of the same test when read by two different observers (0.8%). The study results indicate that PPD-S2 is qualified to be used as the new U.S. reference standard for PPD tuberculin.

Adult↗

A viscoelasticity index for cheese meltability evaluation.

A device especially designed for uniaxial creep test was used in this study. Cheddar cheeses of different fat content were used. To study the linear viscoelastic response of the cheese, temperature of 40 degrees C and stress of 1119.5 Pa were chosen. Tests were carried out at cheese ages of 1, 3, 6, and 12 wk after production date. A six-element Kelvin model was used to model the creep data. Instantaneous slope of the creep curve was defined as the viscoelasticity index. The results showed that the viscoelasticity index based on viscoelastic parameters could be used for predicting cheese meltability. From the analysis of variance test, it was evident that that the viscoelasticity index can be used to distinguish the meltability of Cheddar cheeses of different ages and fat levels.

Cheese↗