Biomedical subjects

C Huang

Publications and source records attributed to C Huang.

At least 235 records · Page 13Linked to original sources

PubMed1999

Prevalence of joint pain is higher among women in rural Japan than urban Japanese-American women in Hawaii.

OBJECTIVE: Environmental factors such as farming contribute to the frequency of joint symptoms. The purpose of this study is to explore the possible role of environment (lifestyle), by comparing the prevalence of joint pain between Japanese in a rural farming district in Japan and in urban Hawaii. SUBJECTS AND METHODS: Current or previous pain at specific joints was surveyed among 222 women in rural Japan and 638 Japanese women in urban Hawaii aged 60-79. The age adjusted prevalence was compared using logistic regression. RESULTS: The prevalence of pain at one or more joints was approximately 70% in Japan and 50% in Hawaii. The prevalence of knee pain in Japan ranged from 36% at ages 60-69 years to 53% at 70-79 years (mean 41%), whereas knee pain affected only 20% of women in Hawaii in both age groups. The odds ratio (and 95% CI) was 3.2 (2.1, 4.8) for knee pain, and 4.0 (2.2, 7.4) for mid-back pain in Japan, compared with Hawaii. Pain was also significantly more common in Japan at the shoulder, elbow, and ankle, but not at other joints. Women in Japan were shorter and weighed less than in Hawaii. Adjustment for body mass index increased the odds ratios to 4.4 (2.9, 6.8) for knee, and 4.5 (2.4, 8.5) for mid-back pain. CONCLUSION: Although the potential influence of cultural factors or other sources of bias cannot be ruled out, the large differences in the prevalence of pain at specific joints suggest that environmental factors are probably responsible, because both populations are of similar genetic stock.

Aged↗

PubMed1999

Absence of the derived allele at the DYS199 locus in 3 NE Chinese populations.

The allelic states of DYS199 locus were studied by allele-specific PCR. We found that all of the 107 samples chosen from three populations of northeast China had DYS199 C alleles. The result excluded the possibility that this mutation first identified in native American populations came from the three populations of northeast China.

Alleles↗

PubMed1999

[Angiotensin 1-converting enzyme gene insertion/deletion polymorphism in patients with coronary artery disease and essential hypertension and its nucleotide sequence].

OBJECTIVE: To determine angiotensin 1-coverting enzyme(ACE) gene insertion/deletion(I/D) polymorphism distributions in patients with coronary artery disease(CAD) and essential hypertension(EH),and to detect its nucleotide sequence. METHODS: ACE genotypes of 137 patients with CDA, 42 patients with EH and 63 healthy people were detected by PCR methods. At the same time, nucleotide sequences of D and I allele were determined by fluorescein labeling automatic sequencing method. RESULTS: the frequency of DD genotype in CAD group was significantly higher than that in control group (0.45 and 0.21,P < 0.01), but there was no significant difference of ACE geneI/D polymorphism distribution between EH and control group. The lengths of D and I alleles are 191bp and 479bp separately and their nucleotide sequences are somewhat different with the results of foreign countries. CONCLUSION: ACE gene I/D polymorphism is an independent risk factor of CAD, but it has no relationship with EH. A 288bp insertion segment results in the I/D polymorphism of ACE gene.

Adult↗

PubMed1999

Nitric oxide production in peritoneal macrophages from peritoneal dialysis patients with bacterial peritonitis.

Nitric oxide (NO) is produced by various cell types, and it is an important mediator in many biological processes, including macrophage-mediated cellular host defense. The relevance and amount of NO production in peritonitis during peritoneal dialysis (PD) treatment is still not clear. We studied whether human peritoneal macrophages (PMphi) isolated from healthy PD patients or PD patients with peritonitis showed different spontaneous or lipopolysaccharide (LPS)/interferon gamma (IFN-gamma)-induced NO production (LPS, 1 ng/mL-10 microg/mL; IFN-gamma, 10-1000 U/mL; incubation between 6-48 hours; measured by Griess reagent). Results were compared with human blood monocytes (HBM) isolated from buffy coats. Inducible nitric oxide synthetase (iNOS) mRNA expression was looked for in PMphi by reverse transcriptase polymerase chain reaction (RT-PCR). Furthermore, plasma (P) and peritoneal dialysate effluent (D) nitrite concentrations were measured in vivo. The dialysate-to-plasma ratio (D/P) of nitrite concentration was inverse in the case of peritonitis compared to infection-free patients (peritonitis D/P = 1.3, non peritonitis D/P = 0.4; p < 0.01). PMphi from peritonitis patients produced higher amounts of NO than did those from infection-free patients (0.040+/-0.044 nmol per microgram cell protein versus 0.018+/-0.015 nmol per microgram cell protein, p < 0.05). NO release could not be further enhanced by stimulation with LPS plus IFN-gamma (1 ng/mL, 250 U/mL, respectively). However, NO production in PMphi from infection-free patients increased during in vitro stimulation (0.044+/-0.031 nmol per microgram cell protein versus 0.018+/-0.015 nmol per microgram cell protein, p < 0.01). An increase of iNOS mRNA expression could be demonstrated by RT-PCR. Blood monocytes from healthy donors also increased NO release during cytokine stimulation (0.032+/-0.015 nmol per microgram cell protein versus 0.019+/-0.009 nmol per microgram cell protein, p < 0.05). Our results indicate that significant amounts of NO are released intraperitoneally in the case of bacterial peritonitis. PMphi represent a site of NO production, though the absolute amounts released in vitro are only moderate. NO production can be induced in PMphi and HBM by LPS/IFN-gamma stimulation in vitro.

Adult↗

PubMed1999

Annual risk of tuberculous infection in Taiwan, 1996-1998.

Tuberculosis is still an important public health issue in Taiwan, and monitoring the trend of annual risk of infection (ARI) with Mycobacterium tuberculosis is essential. In this study, we conducted tuberculin skin tests to estimate the prevalence and annual risk of M. tuberculosis infection in first-grade schoolchildren in Taiwan Province. Because mass bacille Calmette-Guérin (BCG) vaccination programs have been carried out here, only non-BCG-vaccinated students were tested. From September 1996 through June 1998, there were 520,866 registered first-grade elementary school students in Taiwan Province. Of them, 15,147 (2.9%) were non-BCG-vaccinated, as determined by the absence of a BCG scar. All of them were tested for M. tuberculosis infection with 1 tuberculin unit (0.1 mL injection) of purified protein derivative RT23, by means of the Mantoux technique. Among the tested schoolchildren, 430 (2.8%) had a positive tuberculin reaction. Thus, the calculated ARI was 0.44%. The ARI varied in different areas of Taiwan, being highest (1.04%) in Nantou County and lowest (0.14%) in Miaoli and Tainan Counties. The ARI in aboriginal areas (1.16%) was 2.7 times that in nonaboriginal areas (0.42%). Our results indicate that the M. tuberculosis ARI is still high in Taiwan. To achieve the World Health Organization target of less than 0.1% for industrialized countries, we must intensify tuberculosis control programs in Taiwan.

BCG Vaccine↗

PubMed1999

[Mutation analysis of p16 gene in non-small cell lung carcinomas].

OBJECTIVE: To investigate the role of p16 gene in the tumorigenesis of non-small cell lung carcinomas (NSCLC). METHODS: Homozygous deletion and mutation of exon 2 of p16 genes in 40 NSCLC tissues were analyzed using PCR and dsDNA direct sequencing technique. RESULTS: In 2 NSCLC tissues, homozygous deletions of p16 gene were detected; in 14 NSCLC tissues, 19 point mutations and a frameshift were detected. CONCLUSION: Point mutations of p16 gene were frequent and might play a role in the initiation and progression of NSCLC. Nt380 in this gene was a hot spot of mutation.

Carcinoma, Non-Small-Cell Lung↗

PubMed1999

Somatic embryogenesis of Echinodorus orisis L. and the kinetic changes of the endogenous hormones contents during the embryogenetic process.

Somatic embryogenesis was achieved in young Leaf cuttings of Echinodorus orisis L., an aquatic ornamental plant, in a short period (25 days). Among the cytokinins and their combinations tested, 6-BA (1 mg/L) and Zt (1 mg/L) in MS medium induced the highest efficiency (100%) of somatic embryogenesis, with a maximum of 4.87 embryoids per explant. Roots instead of somatic embryos were formed when NAA (0.5 mg/L) was added to MS medium containing Zt (1 mg/L). Matured embryoids were germinated and rooted in MS medium with IAA (1 mg/L) after 5 days cultivation. Seventy-two percent of the rooted plantlets transplanted survived in the aquarium. The endogenous hormone contents in various stages of somatic embryogenetic process were measured by HPLC. The concentrations of all the hormones tested were about 2 times that of the cuttings from the untreated fresh leaves after 10 days incubation. Meanwhile, the concentration of IAA presents two peaks after 10 and 25 days of cultivation, respectively. The cytokinin (Zt and ZR) peak, about 8 times more than CK, appeared in 15 days cultivation when the heart-shaped embryos formed. The fluctuation of the GA3 concentration was very similar to that of cytokinin. The ABA, however, remains stable at quite high concentration after 10 days of cultivation.

Plant Cells↗

PubMed1999

Study of activity of promoter from mouse alpha 2(I) procollagen gene.

OBJECTIVE: To clarify the segment and sequence in mouse alpha 2(I) procollagen gene which are responsible for high transcriptional activity during fibrogenesis. METHODS: This study was focused on further fractional analysis of 2 kb-length mouse alpha 2(I) procollagen gene promoter activity. Six chimeric genes were constructed in which various lengths of sequences between 2000 bp upstream of the start of transcription of the mouse alpha 2 (I) procollagen gene and 54 bp downstream of this site were fused to chloramphenicol acetyltransferase (CAT) reporter gene. These recombinant plasmids were transfected transiently to collagen-producing cells (NIH/3T3) and non-collagen-producing cells (COS7) with liposomal transfection method. The activities of putative promoters were observed and compared by means of CAT measurement in the transfected cells. RESULTS: The highest and partial cell specific CAT expression was observed in construction driven by -780 to bp fragment. The construction containing sequence deleted the proximal 500 bp from the transcription start site and part of exon I, and resulted in the lowest CAT expression. CONCLUSIONS: Some essential elements might exist in the 500 bp fraction proximal to transcription start site and part of exon I in mouse alpha 2(I) procollagen gene. The high potential promoter sequence between -780 bp from the start of transcription site and bp from this site is of great significance in our following study of searching for specific DNA-binding proteins in activated collagen-producing cells.

3T3 Cells↗

PubMed1999

Molecular mechanism of recessive congenital methemoglobinemia in Chinese pedigrees.

OBJECTIVE: To investigate the molecular mechanism of recessive congenital methemoglobinemia (RCM) in Chinese and to establish a gene diagnostic method of polymerase chain reaction-restricted fragment length polymorphism (PCR-RFLP). METHODS: Total RNA was isolated from the peripheral leukocytes of the propositus and b5R cDNA synthesized by reverse transcription-polymerase chain reaction (RT-PCR). The coding region of b5R cDNA was analyzed by sequencing of the RT-PCR products. RESULTS: Both propositi A and B were found to be homozygotes for a G to A transition at codon 57 in exon 3, changing a guanine to an adenine. This point mutation was not an artificial occurrence during polymerase chain reaction (PCR), as confirmed by Msp I restriction enzyme analysis of the genomic DNA. Propositus A's mother and propositus B's sister and her nephew were found to be heterozygotes for the mutation. CONCLUSION: A guanine-to-adenine transition at codon 57, replacing arginine with glutamine, was the molecular basis for RCM in two Chinese families.

Adult↗

PubMed1999

[Posttraumatic or inflammatory acute respiratory distress syndrome on high altitude area: a retrospective analysis of 94 deaths due to ARDS/MOF].

OBJECTIVE: To determine the characteristic predictors of acute respiratory distress syndrome (ARDS) in the high altitude area of China. METHODS: According to the diagnostic criteria of ARDS, 2 325 cases were screened in the recent 10 years. Except malignant tumors, cardio-cerebrovascular diseases, chronic obstructive pulmonary disease, and chronic multiple organ failure, the causes of death were analysed retrospectively. RESULTS: 94 cases (4.04%) were diagnosed as ARDS, but in the primary case record, only 27 cases (1.16%) had been diagnosed as ARDS/MOF. Of the 94 ARDS patients, 79 complicated by extrapulmonary organ damage involving the kidney, heart, liver, gastro-intestinal tract, and brain. A total of 305 organs were involved (average 3.24 organs each case). Lung failure only accounted for 15 cases. CONCLUSIONS: The combination of the diagnostic criteria of ARDS for high altitude area and flate area, injury severity scale, blood gas monitoring, and integrated traditional Chinese medicine and western medicine may improve the prognosis of ARDS.

Adolescent↗

PubMed1999

[The clinical analysis of corticosteroid ocular hypertension and corticosteroid glaucoma after photorefractive keratectomy].

OBJECTIVE: To inquire into the incidence, clinical characteristics and therapeutic effects of corticosteroid hypertension and corticosteroid glaucoma after photorefractive keratectomy (PRK). METHODS: The authors completed a follow up study on 1 590 eyes on which this procedure was performed and corticosteroid (0.1% fluoromethalone, FML) eye drops were applied 4 to 6 months post-operatively to observe intraocular pressure at 1, 3, 6, 12 and 24 months, and treated the eyes with increase of intraocular pressure. RESULTS: Corticosteroid ocular hypertension or corticosteroid glaucoma occurred in 2.70% of 1 590 eyes. The intraocular pressure of the eyes was recovered to normal in all patients after treatments of stopping FML eye drops, using topical 0.5% timolol (or 0.5% levobunolol hydrochloride), taking diamox orally or receiving trabeculectomy. CONCLUSIONS: Topical application of corticosteroid may cause corticosteroid hypertension and corticosteroid glaucoma after PRK, and visual function damage may occur in a few eyes. Under this situation, the corticosteroid eye drops should be stopped and glaucomatous treatment should be given.

Adult↗

PubMed1999

[Enhanced cytotoxicity of VM-26 in human malignant glioma cells by calcium channel blocker nicardipine in vitro].

Using the monolay tumor cell culture system and the method or MTT colorimetric analysis, the cytotoxicity of the anticancer drug VM-26 and Nicardipine(NCDP) in human malignant glioma cell line U251 was studied. The results showed that the cytotoxicity of VM-26 in U251 was enhanced by NCDP at a low dose which did not show direct cytotoxicity. The authors considered that VM-26 combined with NCDP can heighten the intracellular anticancer drug concentration, reverse the drug resistance and heterogeneity in human malignant glioma cells. The mechanism of the enhanced effect was also discussed. These findings will provide an alternative chemotherapeutic clue to treat the postoperative malignant gliomas.

Antineoplastic Agents↗

PubMed1999

[Human motion analysis system based on common video-camera].

A new human motion analysis system based on common video-camera is introduced in this paper. The image processing technique is used to recognize and track anatomic landmarks, which makes data processing more quickly and accurately. The system is cost-effective and can be easily operated because the common video-cameras instead of special instruments are used. Furthermore, the system can also be used for detection and analysis of other low-speed moving objects.

Algorithms↗

PubMed1999

[Fractal dimension analysis of the surface EMG].

Fractal analysis is a new method for biomedical signal processing. Present research on surface EMG and its parameterization method were introduced in this paper. Experiments were performed on three conditions: (1) different muscle contraction degree, (2) different static load, (3) different motion pattern. Problems and prospects in engineering application were also discussed here.

Adult↗

PubMed1998

Expression of dominant negative Erk2 inhibits AP-1 transactivation and neoplastic transformation.

The mitogen activated protein (MAP) kinases or extracellular signal-regulated kinases (Erks) are activated in response to Ras expression or exposure to tumor promoters or to growth factors, and have been implicated in AP-1 transactivation in some models. We have shown that tumor promoter induced activation of the transcription factor AP-1 is required for induced neoplastic transformation in the Balb/C JB6 cell model. Jun and Fos family protein levels have been found not to be limiting for AP-1 response. The present study asks whether activation of Erks1 and 2 is required for AP-1 transactivation and transformation of JB6 cells and whether Erks might be targeted for cancer prevention. Expression of either of two different dominant negative kinase inactive Erk2 mutants in transformation sensitive (P+) JB6 cells substantially inhibited the tumor promoter induced activation of Erks1 and 2 and of AP-1 measured by a collagenase-luciferase reporter. Multiple mutant Erk2 expressing clonal lines were also rendered non-responsive to induced neoplastic transformation. These observations, together with our recent finding attributing AP-1 non-responsiveness to Erk deficiency in a clonal line of transformation resistant (P-) cells, argue for a requirement for Erks1 and/or 2 activation in AP-1 transactivation in the mouse JB6 neoplastic progression model, and suggest the utility of Erks as a prevention target.

Animals↗

PubMed1998

Gene therapy in allergic encephalomyelitis using myelin basic protein-specific T cells engineered to express latent transforming growth factor-beta1.

A myelin basic protein (MBP)-specific BALB/c T helper 1 (Th1) clone was transduced with cDNA for murine latent transforming growth factor-beta1 (TGF-beta1) by coculture with fibroblasts producing a genetically engineered retrovirus. When SJL x BALB/c F1 mice, immunized 12-15 days earlier with proteolipid protein in complete Freund's adjuvant, were injected with 3 x 10(6) cells from MBP-activated untransduced cloned Th1 cells, the severity of experimental allergic encephalomyelitis (EAE) was slightly increased. In contrast, MBP-activated (but not resting) latent TGF-beta1-transduced T cells significantly delayed and ameliorated EAE development. This protective effect was negated by simultaneously injected anti-TGF-beta1. The transduced cells secreted 2-4 ng/ml of latent TGF-beta1 into their culture medium, whereas control cells secreted barely detectable amounts. mRNA profiles for tumor necrosis factor, lymphotoxin, and interferon-gamma were similar before and after transduction; interleukin-4 and -10 were absent. TGF-beta1-transduced and antigen-activated BALB/c Th1 clones, specific for hemocyanin or ovalbumin, did not ameliorate EAE. Spinal cords from mice, taken 12 days after receiving TGF-beta1-transduced, antigen-activated cells, contained detectable amounts of TGF-beta1 cDNA. We conclude that latent TGF-beta1-transduced, self-reactive T cell clones may be useful in the therapy of autoimmune diseases.

Animals↗

PubMed1998

Increased synthesis of phosphocholine is required for UV-induced AP-1 activation.

Exposure of mammalian cells to UV irradiation stimulates phosphatidylcholine hydrolysis and activates the transcription factor AP-1. Since phosphocholine (PCho), a phospholipid metabolite, is a potential regulator of mitogenesis and carcinogenesis, we examined the effect of UV exposure on the formation of PCho and the possible mediatory role of PCho in UVB-and UVC-induced activation of AP-1 in mouse JB6 epidermal cells. We found that both UVB and UVC irradiation resulted in increased PCho levels. Hemicholinium-3 (HC-3), an inhibitor of choline kinase, strongly inhibited UV-induced AP-1 activity. By contrast, relatively low levels of PCho (80 microM) or choline (20 microM) nearly doubled UV-induced AP-1 activity, while higher (2-20 mM) concentrations of PCho alone stimulated AP-1 activity 6-8-fold. Importantly, HC-3 inhibited only the stimulatory effect of choline, but not of PCho, on AP-1 activity. Of the mitogen-activated protein (MAP) kinases involved in the regulation of AP-1 activity, UVC stimulated the MAP kinase family ERK-1/ERK-2, JNK as well as p38 kinase activity. These UVC effects were all inhibited by HC-3. With UVB, by contrast, only the activation of ERK-1/ERK-2 was inhibited by HC-3. The data suggest that increased formation of PCho is required for UV-induced activation of AP-1 by an ERK-1/ERK-2-dependent mechanism.

Animals↗

PubMed1998

The role of tyrosine phosphorylation of cortactin in the locomotion of endothelial cells.

Cortactin, a filamentous actin cross-linking protein and a substrate of Src protein tyrosine kinase, is phosphorylated at tyrosine residues upon stimulation by extracellular signals. We have previously demonstrated that the filamentous actin cross-linking activity of cortactin is attenuated by Src (Huang, C., Ni, Y., Gao, Y., Haudenschild, C. C., and Zhan, X. (1997) J. Biol. Chem. 272, 13911-13915). In vitro, tyrosine phosphorylation of cortactin occurs specifically within the region between the proline-rich sequence and the Src homology 3 domain. Among the nine tyrosine residues in this region, mutations at Tyr421, Tyr466, and Tyr482 significantly reduced Src-meditated tyrosine phosphorylation both in vitro and in vivo. Ectopic expression of wild-type cortactin in ECV304, a spontaneously transformed human umbilical endothelial cell line, resulted in an enhanced cell migration. In contrast, overexpression of a cortactin mutant deficient in tyrosine phosphorylation impaired the migration of endothelial cells. These findings reveal an intracellular signaling mechanism whereby the motility of endothelial cells is regulated by a Src-mediated tyrosine phosphorylation of cortactin.

Actins↗