Search PubMed⌕ Search

Biomedical subjects

C Wang

Publications and source records attributed to C Wang.

At least 271 records · Page 15Linked to original sources
PubMed2001

[Determination of domoic acid in water and aquatic animals by high performance liquid chromatography].

The content of domoic acid in water and in the body of some aquatic animals was detected by HPLC in order to find out the pollutant condition. The result showed that HPLC analysis was a simple and effective method for determining domoic acid in water and aquatic animals. Domoic acid has been found in some marine shellfish and not in seawater or freshwater. It is necessary to strengthen monitoring the contamination of domoic acid to prevent the toxin poisoning.

Animals↗
PubMed2001

[Changes in dietary pattern and certain nutrition-related diseases in urban and rural residents of Jiangsu province in 1990s].

A study on the relations of dietary pattern and mortality of some chronic diseases in urban and rural residents of Jiangsu Province in the past decade was made on the basis of the results of food consumption survey and disease surveillance. The results showed that food consumption and dietary pattern changed remarkably during the 1990s. Grain consumption was decreased, but the consumption of animal food was markedly increased. Though the score of desirable dietary pattern(DDP) in urban residents was more than 90, the deducted scores owing to over-consumption of animal food were increased. The mortality form infectious diseases was evidently decreased. While the death rates of some chronic diseases, such as diabetes, hypertension, coronary heart disease, colorectal cancer and breast cancer was increased rapidly in the urban residents. Sufficient attention should be paid to the negative effects of the change of dietary pattern on the health, especially of urban residents.

Breast Neoplasms↗
PubMed2001

[The reconstruction of laryngeal function in subtotal laryngectomy by pedicled flaps].

OBJECTIVE: To explore the possibility of subtotal laryngectomy in the treatment of advanced laryngeal cancer and selection of reconstruction. METHODS: Forty patients were treated surgically by subtotal laryngectomy with preservation of arytenoid cartilage and perichondrium. The pedicled flaps between cricoid cartilage and arytenoid cartilage were sewed up. The new larynx was reconstructed by suturing the cricoid or trachea to the hyoid bone or the tongue base. RESULTS: The 3 and 5 year survival rates were 85.0% and 76.2% respectively. Decannulation rate was 92.5%. CONCLUSION: The reconstruction of laryngeal function in subtotal laryngectomy by pedicled flaps not only is safe and beneficial to the patients with the cancers above the cricoid, but also improves the quality of patient's life.

Adult↗
PubMed2001

[Clinical study of the sentinel lymph node of patients with laryngeal and hypopharyngeal carcinomas].

OBJECTIVE: To investigate the methods of detecting the sentinel lymph node of laryngeal and hypopharyngeal carcinomas and its predictive value in the cervical metastasis of the carcinoma. METHODS: In 29 patients who suffered from laryngeal or hypopharyngeal carcinoma with NO neck, the patent blue was injected into the surrounding tissue of the tumor during the operation to identify the sentinel lymph nodes. The sentinel lymph nodes were dyed blue. The frozen histopathology was done during the operation, the lymph nodes at the ipsilateral side of the neck were dissected completely, and the routine histopathology was done as the gold standard to study the predictive value of the sentinel lymph node in the metastasis of the cervical node. RESULTS: Of 29 patients, 28 patients' sentinel lymph nodes were detected successfully during operation. There was an average of 2.5 lymph nodes per side per patient. Most of the sentinel lymph nodes were in the level II and level III regions of the ipsilateral side of the neck, and there were bilateral sentinel nodes in patients suffered from superglottic carcinoma. Three patients' sentinel lymph nodes were found to be positive in the frozen inspection, and the routine histopathology confirmed the result. The micrometastasis rate was 10.7% (3/28). There were no metastatic lymph nodes found in patients who were negative for the sentinel lymph nodes during the operative frozen histopathology. The predicted value of the sentinel lymph nodes to the cervical lymph node metastasis was 100 per cent. CONCLUSION: There is a very important predicted value of sentinel lymph nodes in the cervical metastasis of patients suffered from laryngeal and hypopharyngeal carcinomas. It could reduce the neck dissection in patients with laryngeal and hypopharyngeal carcinomas.

Adult↗
PubMed2001

Experimental study of the morphology of cerebral bridging vein.

OBJECTIVE: To investigate the morphological properties of pig cerebral bridging vein. METHODS: The morphology and fibre arrangement of 15 cerebral bridging veins obtained from 7 Danish Yorkshire landrace pigs were observed. RESULTS: There was a narrow region at the junction of the cerebral bridging veins and superior sagittal sinus termed "outflow cuff segment". The diameter and length of outflow cuff segment were much smaller and the thickness was higher than those of the cerebral bridging veins ( P < 0.01), and circumferential collagen fibres were most dense in the outflow cuff segment. The opening angle of the outflow cuff segment and the cerebral bridging veins were 115 +/- 4 degrees and 120 +/- 4 degrees ( P > 0.05). CONCLUSIONS: There were differences in fibre arrangement and morphological properties between the outflow cuff segment and the cerebral bridging vein, just like a resistance valve, the outflow cuff segment may play an important role in stabilizing cerebral venous outflow and regulating intracranial pressure.

Animals↗
PubMed2001

[Cross reticular bone grass used in slotted acetabular augmentation].

OBJECTIVES: To investigate the technique of cross reticular bone grass used in slotted acetabular augmentation ( SAA), and enrich the surgical procedures in the treatment of the DDH. METHODS: Thirty seven cases were treated with cross reticular bone grass used in SAA, including developmental dysplasia of the hip (DDH) and coaxial plana caused by Legg-Perthes disease. RESULTS: SAA provided an easy way to shape an adept acetabulum with cancellous bone graft. After the operation a stable hip was obtained. Thirty cases were good, 2 remained limping, 1 had a limitation of abduction of the hip. CONCLUSIONS: SAA is a safe and effective way to provide an adequate coverage of the femoral head. It is a developed shelf procedure with good stability and for a surgical frame of the hip. SAA method is safe and technically simple.

Acetabulum↗
PubMed2001

[Biological stabilities and identification of a highly metastatic subpopulation from a human osteosarcoma cell line].

OBJECTIVE: To investigate the biological stabilities and the identification of a human highly metastatic osteosarcoma subpopulation. METHODS: Tumor pieces of the cell were inoculated into nude mice orthotopically. Lung node metastatic foci were obtained by culturing, the procedure was repeated for 3 cycles. Changes were observed in intra-tibial tumor growth, pulmonary metastatic rate in vivo, morphological characteristics, expressions of BMP, vimentin, actin, NEC and karyotype analyses of every passage in vitro. RESULTS: The intra-tibial tumor growth rates were 100%, the proliferation abilities were stable, and the pulmonary metastatic rates were higher than 80%. The expressions of BMP, vimentin, actin were positive, but the expression of NSE was negative. Its morphological characteristics the antigen-positive substances and karyotype were similar to those observed in human osteosarcoma. CONCLUSION: SOSP-M1 with very stable biological characteristics is a good model for the study of human osteosarcoma.

Animals↗
PubMed2000

A novel nuclear localization signal in human DNA topoisomerase I.

DNA topoisomerase (topo) I is a nuclear enzyme that plays an important role in DNA metabolism. Based on conserved nuclear targeting sequences, four classic nuclear localization signals (NLSs) have been proposed at the N terminus of human topo I, but studies with yeast have suggested that only one of them (amino acids (aa) 150-156) is sufficient to direct the enzyme to the nucleus. In this study, we expressed human topo I fused to enhanced green fluorescent protein (EGFP) in mammalian cells and demonstrated that whereas aa 150-156 are sufficient for nuclear localization, the nucleolar localization requires aa 157-199. More importantly, we identified a novel NLS within aa 117-146. In contrast to the classic NLSs that are rich in basic amino acids, the novel NLS identified in this study is rich in acidic amino acids. Furthermore, this novel NLS alone is sufficient to direct not only EGFP into the nucleus but also topo I; and the EGFP.topo I fusion driven by the novel NLS is as active in vivo as the wild-type topo I in response to the topo I inhibitor topotecan. Together, our results suggest that human topo I carries two independent NLSs that have opposite amino acid compositions.

Amino Acid Sequence↗
PubMed2000

Ligand-induced strain in hydrogen bonds of the c-Src SH3 domain detected by NMR.

Changes in the molecular conformation of proteins can result from a variety of perturbations, and can play crucial roles in the regulation of biological activity. A new solution NMR method has been applied to monitor ligand-induced changes in hydrogen bond geometry in the chicken c-Src SH3 domain. The structural response of this domain to ligand binding has been investigated by measuring trans-hydrogen bond (15)N-(13)C' scalar couplings in the free state and when bound to the high affinity class I ligand RLP2, containing residues RALPPLPRY. A comparison between hydrogen bonds in high resolution X-ray structures of this domain and those observed via (h3)J(NC') couplings in solution shows remarkable agreement. Two backbone-to-side-chain hydrogen bonds are observed in solution, and each appears to play a role in stabilization of loop structure. Reproducible ligand-induced changes in trans-hydrogen bond scalar couplings are observed across the domain that translate into changes in hydrogen bond length ranging between 0.02 to 0.12 A. The observed changes can be rationalized by an induced fit mechanism in which hydrogen bonds across the protein participate in a compensatory response to forces imparted at the protein-ligand interface. Upon ligand binding, mutual intercalation of the two Leu-Pro segments of the ligand between three aromatic side-chains protruding from the SH3 surface wedges apart secondary structural elements within the SH3 domain. This disruption is transmitted in a domino-like effect across the domain through networks of hydrogen bonded peptide planes. The unprecedented resolution obtained demonstrates the ability to characterize subtle structural rearrangements within a protein upon perturbation, and represents a new step in the endeavor to understand how hydrogen bonds contribute to the stabilization and function of biological macromolecules.

Amino Acid Sequence↗
PubMed2000

Extracellular signal-regulated kinase plays an essential role in hypertrophic agonists, endothelin-1 and phenylephrine-induced cardiomyocyte hypertrophy.

The extracellular signal-regulated kinase (ERK) pathway is activated by hypertrophic stimuli in cardiomyocytes. However, whether ERK plays an essential role or is implicated in all major components of cardiac hypertrophy remains controversial. Using a selective MEK inhibitor, U0126, and a selective Raf inhibitor, SB-386023, to block the ERK signaling pathway at two different levels and adenovirus-mediated transfection of dominant-negative Raf, we studied the role of ERK signaling in response of cultured rat cardiomyocytes to hypertrophic agonists, endothelin-1 (ET-1), and phenylephrine (PE). U0126 and SB-386023 blocked ET-1 and PE-induced ERK but not p38 and JNK activation in cardiomyocytes. Both compounds inhibited ET-1 and PE-induced protein synthesis and increased cell size, sarcomeric reorganization, and expression of beta-myosin heavy chain in myocytes with IC(50) values of 1-2 microm. Furthermore, both inhibitors significantly reduced ET-1- and PE-induced expression of atrial natriuretic factor. In cardiomyocytes transfected with a dominant-negative Raf, ET-1- and PE-induced increase in cell size, sarcomeric reorganization, and atrial natriuretic factor production were remarkably attenuated compared with the cells infected with an adenovirus-expressing green fluorescence protein. Taken together, our data strongly support the notion that the ERK signal pathway plays an essential role in ET-1- and PE-induced cardiomyocyte hypertrophy.

Animals↗
PubMed2000

Cell-cycle dysregulation in breast cancer: breast cancer therapies targeting the cell cycle.

Breast cancer is the most commonly diagnosed cancer in American women. The underlying mechanisms that cause aberrant cell proliferation and tumor growth involve conserved pathways, which include components of the cell cycle machinery. Proto-oncogenes, growth factors, and steroids have been implicated in the pathogenesis of breast cancer. Surgery, local irradiation, and chemotherapy have been the mainstay of treatment for early and advanced stage disease. Potential targets for selective breast cancer therapy are herein reviewed. Improved understanding of the biology of breast cancer has led to more specific "targeted therapies" directed at biological processes that are selectively deregulated in the cancerous cells. Examples include tamoxifen for estrogen receptor positive tumors and imunoneutralizing antibodies such as trastuzumab for Her2/neu overexpressing tumors. Other novel anticancer agents such as paclitaxel, a microtubule binding molecule, and flavopiridol, a cyclin dependent kinase inhibitor, exert their anticancer effects by inhibiting cell cycle progression.

Adenocarcinoma↗
PubMed2000

Lasting effects of transient postinoculation tenofovir [9-R-(2-Phosphonomethoxypropyl)adenine] treatment on SHIV(KU2) infection of rhesus macaques.

SHIV(KU2) replicates to high levels in inoculated macaques and reproducibly causes an acute depletion of CD4(+) T cells. We evaluated the ability of treatment with the antiretroviral drug 9-R-(2-phosphonomethoxypropyl)adenine (PMPA; tenofovir), begun 7 days postinoculation, to inhibit viral replication and associated pathogenesis. Highly productive infection (plasma viral RNA > 10(6) copy eq/mL) was present and CD4 depletion had started when treatment was initiated. PMPA treatment was associated with a rapid decline in plasma viral RNA to undetectable levels, with parallel decreases in the infectivity of plasma and infectious cells in PBMCs and CSF and stabilization of CD4(+)T-cell levels. Viral dynamics parameters were calculated for the initial phase of exponential viral replication and the treatment-related decline in plasma viremia. Following cessation of treatment after 12 weeks, plasma viral RNA was detectable intermittently at low levels, and spliced viral transcripts were detected in lymph nodes. Although treatment was begun after viral dissemination, high viremia, and CD4 decreases had occurred, following withdrawal of PMPA, CD4(+) T-cell counts normalized and stabilized in the normal range, despite persistent low-level infection. No PMPA-resistance mutations were detected. These results validate the similar viral replicative dynamics of SHIV(KU2) and HIV and SIV, and also underscore the potential for long-term modulation of viral replication patterns and clinical course by perturbation of primary infection.

Adenine↗
PubMed2000

Lysyl hydroxylase 3 is a multifunctional protein possessing collagen glucosyltransferase activity.

Lysyl hydroxylase (EC ) and glucosyltransferase (EC ) are enzymes involved in post-translational modifications during collagen biosynthesis. We reveal in this paper that the protein produced by the cDNA for human lysyl hydroxylase isoform 3 (LH3) has both lysyl hydroxylase and glucosyltransferase (GGT) activities. The other known lysyl hydroxylase isoforms, LH1, LH2a, and LH2b, have no GGT activity. Furthermore, antibodies recognizing the amino acid sequence of human LH3 and those against a highly purified chicken GGT partially inhibited the GGT activity. Similarly, a partial inhibition was observed when these antibodies were tested against GGT extracted from human skin fibroblasts. In vitro mutagenesis experiments demonstrate that the amino acids involved in the GGT active site differ from those required for LH3 activity.

Alternative Splicing↗
PubMed2000

Fourier-transform Raman and infrared spectroscopic analysis of novel biliverdin compounds.

The vibrational spectroscopy of novel biliverdin compounds were studied by Fourier-transform Raman (FT-Raman) and infrared (FT-IR) spectroscopy. The effects of type, length and position of substituents at C(8) and C(12) or C(1) and C(19) of tetrapyrroles on FT-Raman and FT-IR spectra of these compounds, are discussed. The marker bands are developed in order to distinguish between etiobiliverdin and mesobiliverdin.

Biliverdine↗
PubMed2000

Direct measurement of the W boson width in p&pmacr; collisions at radicals = 1.8 TeV

This Letter describes a direct measurement of the W boson total decay width, gamma(W), using the Collider Detector at Fermilab. The measurement uses an integrated luminosity of 90 pb(-1), collected during the 1994-1995 run of the Fermilab Tevatron p&pmacr; collider. The width is determined by normalizing predicted signal and background distributions to 49 844 W-->enu candidates and 21 806 W-->&mgr;nu candidates in the transverse-mass region M(T)<200 GeV and then fitting the predicted shape to the 438 electron events and 196 muon events in the high- M(T) region, 100<M(T)<200 GeV. The result is gamma(W) = 2.04+/-0.11(stat)+/-0.09(syst) GeV.

Journal Article↗
PubMed2000

Activation of the IkappaB kinase complex by TRAF6 requires a dimeric ubiquitin-conjugating enzyme complex and a unique polyubiquitin chain.

TRAF6 is a signal transducer in the NF-kappaB pathway that activates IkappaB kinase (IKK) in response to proinflammatory cytokines. We have purified a heterodimeric protein complex that links TRAF6 to IKK activation. Peptide mass fingerprinting analysis reveals that this complex is composed of the ubiquitin conjugating enzyme Ubc13 and the Ubc-like protein Uev1A. We find that TRAF6, a RING domain protein, functions together with Ubc13/Uev1A to catalyze the synthesis of unique polyubiquitin chains linked through lysine-63 (K63) of ubiquitin. Blockade of this polyubiquitin chain synthesis, but not inhibition of the proteasome, prevents the activation of IKK by TRAF6. These results unveil a new regulatory function for ubiquitin, in which IKK is activated through the assembly of K63-linked polyubiquitin chains.

Amino Acid Sequence↗
PubMed2000

Messenger RNA targeting of rice seed storage proteins to specific ER subdomains.

Rice seeds, a rich reserve of starch and protein, are a major food source in many countries. Unlike the seeds of other plants, which typically accumulate one major type of storage protein, rice seeds use two major classes, prolamines and globulin-like glutelins. Both storage proteins are synthesized on the endoplasmic reticulum (ER) and translocated to the ER lumen, but are then sorted into separate intracellular compartments. Prolamines are retained in the ER lumen as protein bodies whereas glutelins are transported and stored in protein storage vacuoles. Mechanisms responsible for the retention of prolamines within the ER lumen and their assembly into intracisternal inclusion granules are unknown, but the involvement of RNA localization has been suggested. Here we show that the storage protein RNAs are localized to distinct ER membranes and that prolamine RNAs are targeted to the prolamine protein bodies by a mechanism based on RNA signal(s), a process that also requires a translation initiation codon. Our results indicate that the ER may be composed of subdomains that specialize in the synthesis of proteins directed to different compartments of the plant endomembrane system.

3' Untranslated Regions↗