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Biomedical subjects

C H Wu

Publications and source records attributed to C H Wu.

At least 91 records · Page 5Linked to original sources
PubMed2000

Human herpesvirus 8 (KSHV) contamination of peripheral blood and autograft products from multiple myeloma patients.

Human herpesvirus 8 (HHV-8), also known as Kaposi's sarcoma-associated herpesvirus (KSHV), has recently been identified within the bone marrow dendritic cells of multiple myeloma (MM) patients. This virus contains homologues to human cytokines such as IL-6 that could potentially stimulate myeloma cell growth and contribute to disease pathogenesis. Since mobilization chemotherapy may increase circulating dendritic cell numbers, we searched for HHV-8 in peripheral blood mononuclear cells (PBMCs) before and after mobilization chemotherapy given to MM patients. Furthermore, we determined if autograft purging using the CEPRATE SC device would reduce the percentage of HHV-8 infected stem cell products. Only two of the 39 PBMC samples collected prior to mobilization chemotherapy contained PCR detectable virus, yet nine of 37 PBMCs collected on the first day of leukapheresis had detectable HHV-8 (P = 0.016). HHV-8 was more frequently identified in autograft products before vs after Ceprate SC selection (40% vs 15%, P = 0.016). Although the role HHV-8 plays in myeloma pathogenesis remains unclear, these results imply that mobilization chemotherapy increases the numbers of circulating HHV-8-infected dendritic cells within the peripheral blood. In addition, CD34 selection of autograft products in MM patients may reduce the reintroduction of virally infected cells following high-dose chemotherapy. Bone Marrow Transplantation (2000) 25, 153-160.

Antigens, CD34↗
PubMed2000

Relationships of age, menopause and central obesity on cardiovascular disease risk factors in Chinese women.

OBJECTIVE: To evaluate the inter-relationships of age- and menopause- related changes of general obesity and body fat distribution and their independent effects on cardiovascular risk factors. DESIGN: Cross-sectional study. SUBJECTS: One-hundred and thirty-six premenopausal and 193 postmenopausal Chinese women with body mass index (BMI) < 30 kg/m2. MEASUREMENTS: Anthropometric surrogates of general obesity (BMI, total body fat percentage) and central obesity (waist-to-hip ratio, centrality index) were measured. Blood pressure, 75 g oral glucose tolerance test, glycosylated hemoglobin A1c and lipid profiles were also measured. RESULTS: Significant correlation coefficients between age, general obesity, central obesity and cardiovascular disease risk factors were noted. Through the menopausal transition, the BMI and total body fat percentage were increased significantly. After adjustments for age and BMI, the postmenopausal women showed higher android fat percentage, centrality index, glycosylated hemoglobin A1c, serum concentrations of total cholesterol, low-density lipoprotein (LDL) cholesterol and atherogenic indices than the premenopausal women. In multiple stepwise regression models, age exerted independent effects on oral glucose tolerance test 2 h plasma glucose level, systolic and diastolic blood pressure, total cholesterol level, and LDL cholesterol. Menopause was an independent variable in relation to the changes of glycosylated hemoglobin A1c, total and LDL cholesterol levels, triglyceride levels and atherogenic indices. The centrality index was the major independent variable of all the cardiovascular disease risk factors, except total and LDL cholesterol level. However, the variation of total body fat percentage had no independent effect on any cardiovascular disease risk factors. CONCLUSION: Through the aging and menopausal effects, women will increase total body fat content, favoring the central body fat distribution. Age, menopause and central obesity were all independent and significant factors to the cardiovascular disease risk factors in Chinese women.

Adipose Tissue↗
PubMed2000

Antithrombotic effect of rutaecarpine, an alkaloid isolated from Evodia rutaecarpa, on platelet plug formation in in vivo experiments.

In this study, platelet thrombi formation was induced by irradiation of mesenteric venules with filtered light in mice pretreated intravenously with fluorescein sodium. Rutaecarpine (200 microg/g) significantly prolonged the latent period of inducing platelet plug formation in mesenteric venules when it was intravenously injected. Rutaecarpine (200 microg/g) prolonged occlusion time by approximately 1.5-fold (control 127 +/- 29 vs. taecarpine 188 +/- 23 s). Furthermore, aspirin (250 microg/g) also showed a similar prolongation of the occlusion time in this experiment. On a molar basis, rutaecarpine was approximately twofold more potent than aspirin at prolonging the occlusion time. Furthermore, rutaecarpine was also effective in reducing the mortality of ADP-induced acute pulmonary thromboembolism in mice when administered intravenously at doses of 25 and 50 microg/g. Intravenous injection of rutaecarpine (50 microg/g) significantly prolonged the bleeding time by approximately 1.5-fold compared with normal saline in the severed mesenteric arteries of rats. Continuous infusion of rutaecarpine (5 microg/g/min) also significantly increased the bleeding time 1. 5-fold, and the bleeding time returned to baseline within 60 min after cessation of rutaecarpine infusion. These results suggest that rutaecarpine has an effective anti-platelet effect in vivo and that it may be a potential therapeutic agent for arterial thrombosis, but it must be assessed further for toxicity.

Adenosine Diphosphate↗
PubMed2000

Decreased GTPase activity of K-ras mutants deriving from human functional adrenocortical tumours.

Our previous studies have shown that seven out of 15 patients with adrenocortical tumours contained K-ras gene mutation. In addition, the mutation type was a multiple-site mutation, and the hot spots were located at codons 15, 16, 18 and 31, which were different from those reported before (codons 12, 13 and 61). To understand whether the mutation hot spots in human adrenocortical tumours were associated with activation of K-Ras oncogene and the alterations of its biocharacteristics, mutant K-Ras genes were cloned from tumour tissues and then constructed with expression vector pBKCMV. Mutant K-Ras genes were expressed at high levels in Escherichia coli and the resultant K-Ras proteins were shown to be functional with respect to their well-known specific, high-affinity, GDP/GTP binding. The purified K-Ras protein from E. coli were then measured for their intrinsic GTPase activity and the GTPase activity in the presence of GTPase-activating protein for Ras. The results showed that the wild-type cellular K-Ras protein (p21BN) exhibits about ten times higher intrinsic GTPase activity than the activated protein (p21BM3) encoded by mutant K-Ras gene, which mutated at codon 60. With regards to the codon 15, 16, 18 and 31 mutant K-Ras proteins (p21BM2), the GTPase activity in the presence of GAP is much lower than that of the normal K-Ras protein, whereas the intrinsic GTPase activity is nearly the same as that of the normal K-Ras protein. These results indicated that mutations at these hot spots of K-Ras gene were indeed activated K-Ras oncogene in adrenocortical tumours; however, their association with tumors needs further experiments to prove.

Adrenal Cortex Neoplasms↗
PubMed2000

Abnormalities of post-caloric nystagmus induced by postural change.

Post-caloric nystagmus, the reverse secondary phase of caloric nystagmus after the cessation of primary-phase nystagmus, can easily be elicited by postural change. It has been related to the mechanism of vestibular adaptation, and exaggerated responses have been shown in some neurological disorders. Post-caloric nystagmus induced by postural change was analyzed in normal young adults (16 ears), elderly people (age > or = 65 years, 18 ears), patients with central lesions (40 ears) and patients with peripheral vestibulopathy (25 ears). The duration, maximum frequency and maximum slow-phase velocity of the primary phase of caloric nystagmus and of post-caloric nystagmus were documented. The duration, frequency and velocity ratios of post-caloric to primary-phase nystagmus were calculated. The results showed that post-caloric nystagmus induced by postural change was observed in 14 ears (88%) of normal young adults, 10 ears (56%) of elderly patients, 31 ears (78%) of patients with central lesions and 22 ears (88%) of patients with peripheral lesions. The duration and slow-phase velocity ratios for the central lesion group were found to be relatively higher than those for the control group (p < 0.05). A significant positive correlation between the intensities of post-caloric and primary-phase nystagmus was found in all groups except in the central lesion group. Abnormalities of post-caloric nystagmus induced by postural change may occur in the form of exaggerated response or failure of elicitation, which were observed with various central neuro-otological lesions and as a result of the aging process.

Adult↗
PubMed2000

Vestibular neuritis: three-dimensional videonystagmography and vestibular evoked myogenic potential results.

Eight patients diagnosed with vestibular neuritis received the newly developed three-dimensional videonystagmography (3D VNG) and vestibular evoked myogenic potential (VEMP) examination in order to localize the lesion site. Two (25%) of the 8 patients exhibited spontaneous nystagmus with 3 components, indicating that both the horizontal semicircular canal (HSCC) and anterior semicircular canal (ASCC) were affected. The remaining 6 patients (75%) displayed only horizontal nystagmus, meaning that only the HSCC was involved. Seven (88%) of the 8 patients had bilateral normal VEMPs, revealing sparing of the posterior semicircular canal (PSCC). In a comparative study, another seven patients with vestibular neuritis 1 year post-treatment also received the caloric test, 3D VNG and VEMP examination. Only one patient exhibited spontaneous nystagmus. An absent caloric response of the lesioned side persisted in 5 (71%) of the 7 patients. However, all patients showed normal VEMPs bilaterally. 3D VNG and VEMP examination indicates that vestibular neuritis mainly affects the superior division of the vestibular nerve, which innervates the HSCC and ASCC. Meanwhile, the function of the PSCC and saccule, innervated by the inferior vestibular nerve, is preserved.

Adolescent↗
PubMed2000

PIR: a new resource for bioinformatics.

UNLABELLED: The Protein Information Resource (PIR) has greatly expanded its Web site and developed a set of interactive search and analysis tools to facilitate the analysis, annotation, and functional identification of proteins. New search engines have been implemented to combine sequence similarity search results with database annotation information. The new PIR search systems have proved very useful in providing enriched functional annotation of protein sequences, determining protein superfamily-domain relationships, and detecting annotation errors in genomic database archives. AVAILABILITY: http://pir.georgetown.edu/. CONTACT: mcgarvey@nbrf.georgetown.edu

Animals↗
PubMed2000

Effects of propofol on functional activities of hepatic and extrahepatic conjugation enzyme systems.

The effect of propofol on the hepatic and extrahepatic conjugation enzyme systems was assessed in vitro using microsomal and cytosolic preparations of human liver, hamster kidney, lung and gut. The functional activities of phase-II enzymes, including uridine diphosphate-glucuronosyltransferase (UDPGT), glutathione S-transferase (GST) and N-acetyltransferase (NAT) were evaluated in the presence of various concentrations of propofol (0.05-1.0 mmol litre-1), using 1-naphthol, 1-chloro-2,4-dinitrobenzene and p-aminobenzoic acid as substrates respectively. Propofol produced concentration-dependent inhibition of UDPGT activity in human liver microsomes. Propofol did not produce significant inhibition of human hepatic GST activity at concentrations below 1.0 mmol litre-1. In contrast, NAT activity was unaffected by propofol 0.05-1.0 mmol litre-1 in human liver cytosolic preparations. In extrahepatic tissues, hamster renal and intestinal UDPGT activities were significantly inhibited by propofol at 0.25-1.0 mmol litre-1. In these tissues, GST and NAT were unaffected by propofol at 1.0 mmol litre-1. Propofol produced differential inhibition of human liver and hamster extrahepatic conjugation enzymes as a result of different substrate and tissue specificities. The potential interference of the metabolic profile of phase-II enzymes as a result of inhibition by propofol (especially of UDPGT and GST) should be considered when using propofol with other drugs for anaesthesia.

Acetyltransferases↗
PubMed2000

Gene therapy applications in gastroenterology and hepatology.

Advantages and disadvantages of viral vectors and nonviral vectors for gene delivery to digestive organs are reviewed. Advances in systems for the introduction of new gene expression are described, including self-deleting retroviral transfer vectors, chimeric viruses and chimeric oligonucleotides. Systems for inhibition of gene expression are discussed, including antisense oligonucleotides, ribozymes and dominant-negative genes.

Gastroenterology↗
PubMed2000

Dysphagia after radiotherapy: endoscopic examination of swallowing in patients with nasopharyngeal carcinoma.

Dysphagia is a late sequela compromising the lives of more than one fourth of patients with nasopharyngeal carcinoma (NPC) who survive long after radiotherapy. By using fiberoptic endoscopic examination of swallowing as a modality for dysphagia evaluation, we were able to easily recognize the functional and anatomic changes in 31 dysphagic NPC patients. The majority of patients were found to aspirate after the act of swallowing (77.4%). Seventeen (54.8%) had tongue atrophy, and 9 (29%) had vocal cord palsy. Dysfunctions such as dry mouth (45.2%), velopharyngeal incompetence (58%), premature leakage (41.9%), delay or absence of swallow reflex (87.1%), poor pharyngeal constriction (80.6%), pharyngeal residue retention (83.9%), penetration or aspiration (93.5%), and silent aspiration (41.9%) were noted in these patients. Multiple dysfunctions were demonstrated in each patient. Abnormality of pharyngeal constriction and/or aberrant upper esophageal sphincter function played the major role in the postswallow aspiration of these irradiated NPC patients. Clinically compromised patients (weight loss of > or =5 kg in 1 year or pneumonia) had more of the above anatomic and functional impairments. The radiation dosage and volume bore no correlation to the time of symptom onset, or to the occurrence of functional changes.

Adult↗
PubMed2000

Overwhelming septic cavernous sinus thrombosis in a woman after combination of high-dose steroid and intravenous cyclophosphamide therapy for lupus nephritis.

There are many treatment methods for lupus nephritis, including high-dose steroids, pulse methylprednisolone, and cyclophosphamide therapy. In cyclophosphamide therapy, there can be some side effects such as nausea, vomiting, and infection. We report on a case receiving a combination of high dose steroid and intravenous cyclophosphamide. Following this, she developed a fever and a protruding right eye, and septic cavernous sinus thrombosis was diagnosed. This complication had never been reported in a patient with systemic lupus erythematosus, and related literature is reviewed.

Adult↗
PubMed2000

Occupational exposures of pharmacists and pharmaceutical assistants to 60 Hz magnetic fields.

We carried out the study to assess, using field surveys and personal dosimetry, the potential exposure of pharmacists and pharmaceutical assistants to 60 Hz magnetic fields in a medical center of Taiwan. Field surveys were conducted twice in the pharmacy where two workers were randomly selected and solicited to wear personal dosimetry instruments for a full-shift assessment of personal exposure. We used an EMDEX II for on site measurements and did not consider any specific instrument or equipment for health care services as potential sources of magnetic field. The results showed that the average magnetic flux densities for the selected areas were between 0.63 mill-Gauss (mG) and 2.23 mG, while the full-shift time-weighted-average exposure for the two selected workers was 4.98 mG and 6.54 mG, respectively. Both inadequate consideration for the field survey of the temporal variability in magnetic flux densities over the workday and that the monitored workers spent almost half of the full-shift working in places outside of the study areas may have contributed to such discrepancy in results between field survey and personal dosimetry. This study suggests that the potential for elevated exposure to 60 Hz magnetic fields in health care settings does exist, and that using job title as a surrogate for magnetic fields exposure classification might entail certain degrees of misclassification. Although limited in its scope and sample size, the study presented here seems to demonstrate the inadequacy of using stationary workplace measurements for the assessment of personal occupational exposure to 60 Hz magnetic fields.

Allied Health Personnel↗
PubMed2000

Nuclear localization of the human mutY homologue hMYH.

The cDNA of the human mutY homologue (hMYH) was cloned from the total RNA of the tumor cell line SU-DHL-1 by reverse transcription-polymerase chain reaction (RT-PCR). Expression of hMYH in a plasmid can partially revert the mutator phenotype of the Escherichia coli mutY mutant MK609(DE3). The majority of the recombinant hMYH protein in E. coli was precipitated in the inclusion bodies. A minor fraction of the soluble recombinant protein was concentrated as the source of the protein in the activity assay. Recombinant hMYH displayed both glycosylase and AP lyase activity. Three independent rabbit antisera against an N-terminal peptide, HY90, a recombinant C-terminal fragment, and the full-length hMYH recombinant protein were prepared and affinity-purified, and these antisera recognized the 59 kDa endogenous hMYH protein in HeLa cells. Immunofluorescent staining experiments with these three antisera showed a consistent nuclear distribution of hMYH, excluding the nucleoli. This nuclear staining pattern was abolished if the antisera were incubated with specific peptide/protein competitors, whereas the staining pattern was unaffected if the antisera were incubated with nonspecific peptide competitors. Consistent with the immunofluorescent staining results, a flag-tagged transfected hMYH also showed a nuclear staining pattern excluding the nucleoli. These results suggest that hMYH is indeed a functional homologue of E. coli MutY and is localized in the nuclei of mammalian cells.

Amino Acid Sequence↗
PubMed2000

Pathway specificity by the bifunctional receptor frizzled is determined by affinity for wingless.

The Frizzled (Fz) protein in Drosophila is a bifunctional receptor that acts through a GTPase pathway in planar polarity signaling and as a receptor for Wingless (Wg) using the canonical Wnt pathway. We found that the ligand-binding domain (CRD) of Fz has an approximately 10-fold lower affinity for Wg than the CRD of DFz2, a Wg receptor without polarity activity. When the Fz CRD is replaced by the high-affinity CRD of DFz2, the resulting chimeric protein gains Wg signaling activity, yet also retains polarity signaling activity. In contrast, the reciprocal exchange of the Fz CRD onto DFz2 is not sufficient to confer polarity activity to DFz2. This suggests that Fz has an intrinsic capacity for polarity signaling and that high-affinity interaction with Wg couples it to the Wnt pathway.

Animals↗
PubMed2000

Total creatinine appearance as indicator of risk of infectious complication in peritoneal dialysis.

Peritonitis and exit-site infections are the main causes of complications in peritoneal dialysis. Death due to infectious complication is also one of the major causes of drop-out. The underlying cause of infection may include malnutrition. Total creatinine appearance (TCA) may reflect overall nutritional status. We determined TCA from the daily dialysate, urine, and estimated gut creatinine of patients and normalized it to actual body weight (nTCA). We examined the relationship between nTCA and the incidence of infection, and between nTCA and infection-related survival. The study included 323 adult patients in a single dialysis center. The mean nTCA of all patients was 19.73 +/- 4.75 mg/kg/day. The patients with an nTCA below 1 standard deviation from the mean (nTCA < 14.98 mg/kg/day) had a significantly higher peritonitis and exit-site infection rate (p < 0.01) and a higher chance of drop-out owing to infection-related complications (p < 0.0001). Our study concluded that the adult patient with malnutrition (nTCA < 14.98 mg/kg/day) has higher risk of infection.

Bacterial Infections↗