Biomedical subjects

W Hu

Publications and source records attributed to W Hu.

At least 163 records · Page 9Linked to original sources

PubMed1999

[A gene analysis of familial lipoprotein lipase deficiency in China].

OBJECTIVE: To investigate the gene mutation of lipoprotein lipase(LPL) of familial LPL deficiency in China. METHODS: The DNA sequencing of LPL gene of the patients was performed with the dideoxy method based on the polymerase chain reaction amplification using the genomic DNA as a template. RESULTS: It was identified that a missense mutation in exon 6 of LPL gene (6G(979)-->A) resulted in the substitution of Glu(242) by Lys in a heterozygous state. CONCLUSION: The missense mutation of LPL may play a key role in the decrease of LPL activity. This is the first report about the gene mutation of LPL at this site in familial LPL deficiency. Moreover, it contributes to the elucidation of the pathophysiological mechanisms of atherosclerosis and some metabolic diseases.

Adult↗

PubMed1999

[Bilateral bipartite carpal scaphoid bone: a congenital disease or unrecognized pseudarthrosis? Discussion a propos of a clinical case].

PURPOSE OF THE STUDY: Bipartite scaphoid has long been debated, and is of traumatic origin for some authors or congenital for others. The aim of the study is to distinguish clinical and radiographic criteria for the diagnosis of congenital bipartite scaphoid. MATERIAL AND METHOD: A case of bilateral bipartite scaphoid is presented. To distinguish pseudarthrosis from congenital bipartite scaphoid we used, the revised carpal height ratio of Nattrass, the CT, and magnetic resonance imaging. RESULTS: These examinations showed no collapse and they revealed evidence of articular cartilage around the fragments with the same thickness in all the carpus. CONCLUSION: We believe that congenital origin is more probable but we recommend to follow the patient, with yearly standard wrist radiograph and use, the revised carpal height ratio of Nattrass to research a carpal shift or collapse.

Adult↗

PubMed1999

[Perineural fibrosis of the median nerve at the wrist. Treatment by neurolysis and dermal-hypodermal graft].

UNLABELLED: In the treatment of multiple recurrences of carpal tunnel syndrome due to fibrosis, following repeated nerve release, the authors propose interposition of a composite dermal fat graft raised from the inguinal region, and report four clinical cases using this technique. The objective of this study was to evaluate the efficacy of the graft in terms of clinical and electromyographic results and determine the course of the graft by a postoperative MRI study and a longer follow-up. CLINICAL RESULTS: Nocturnal paraesthesiae resolved in 2 patients, was improved in one patient and remained unchanged in another patient. Objectively, neurological examination showed improvement in 3 cases and no change in 1 case. Electromyographic results: At last follow-up, EMG was improved in only one case. Magnetic resonance imaging: MRI visualized the graft with a fat signal on T1-weighted sequences in every case, with an increase in size over time in 3 cases. The efficacy of the dermal fat graft may seem disappointing, as none of the patients were cured. However, with a mean follow-up of more than two years, we have not observed any deterioration of the clinical features, and no surgical revision for carpal tunnel syndrome. This technique appears to increase graft survival, as the blood supply to the subdermis is restored more rapidly via the dermis, which is anatomically a very vascular tissue. There is nevertheless a discrepancy between the clinical results, and EMG and MRI findings, which could be explained by the anatomical lesion of the median nerve, surgically released several times, and by alterations of the perineurium.

Adipose Tissue↗

PubMed1999

Effects of fluoride toothpaste on etched enamel of orthodontic patients.

OBJECTIVE: To investigate the effects of fluoride toothpaste on acid-etched enamel by means of a scanning electron microscope. METHODS: Permanent first premolars extracted for orthodontic reasons were etched with 37% H3PO4. They were divided into two groups in pairs of contralateral teeth. Group 1 was treated with fluoride toothpaste slurry; Group 2 was treated with deionized water. Treatment time was three weeks (one hour, 3 times a day). RESULTS: At the conclusion of the experiment, large amounts of precipitate were observed on the enamel surface of the teeth that were treated with fluoride toothpaste slurry. The etched structures were no longer evident and the enamel surface was smooth. The acid resistance of the teeth was significantly enhanced. However, clearly etched enamel structures were visible on the enamel surface of the teeth that were treated with deionized water. CONCLUSION: Fluoride toothpaste could promote the remineralization of etched enamel and enhance its resistance to acid attack.

Acid Etching, Dental↗

PubMed1999

[Intrapulmonary expression of tumor necrosis factor alpha mRNA and its significance in rats with acute pancreatitis].

It is thought that tumor necrosis factor (TNF) plays an important role in pathogenesis of acute lung injury or ARDS. So we want to get insight into the relationship between intrapulmonary expression of TNF-alpha gene and lung injury during acute necrotizing pancreatitis (ANP). In our study, acute edematous pancreatitis (AEP) and ANP were induced in rats by caerulein and sodium taurocholate respectively. After acute pancreatitis was induced, serum TNF-alpha was assessed by ELISA assay while endotoxin was assessed by limulus lysate test. Intrapulmonary expression of TNF-alpha mRNA was detected by semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) technique. Moreover, content of pulmonary lesion was investigated and graded with microscope. It was found that TNF-alpha concentration in blood elevated markedly after acute pancreatitis was induced, especially in ANP group. Results of RT-PCR revealed that no TNF-alpha mRNA could be detected in lung tissue from those rats undergoing sham-operation, but marked expression appeared 1 hour after AEP or ANP was induced. Upregulation of expression of TNF-alpha gene in the early 3 hours was similar in the two groups with pancreatitis, and since then expression of TNF-alpha mRNA in ANP group was stronger than that in AEP group. Serum endotoxin increased significantly 6 hours after ANP was induced, with a higher level at 12 hour. However, there was no marked change of endotoxin level in AEP group and control group. It is noted that intrapulmonary expression of TNF-alpha gene in ANP group reached its peak as soon as serum endotoxin increased markedly. Lung damage in ANP group was more serious than that in AEP group significantly. Score of lung injury correlated well with TNF-alpha concentration in blood and expression of its gene in lung tissue in either AEP group or ANP group, as well as with serum endotoxin in ANP group. So overwhelm expression of some harmful cytokines like TNF-alpha in lung tissue may be the main cause of lung injury during acute necrotizing pancreatitis, and stimulation of endotoxiemia can at least partly explain the upregulation of expression of TNF-alpha gene.

Animals↗

PubMed1999

[Role of neuronal nitric oxide synthase in dynorphin spinal neurotoxicity and analgesia in rats].

OBJECTIVE: To investigate the different role of neuronal constitutive nitric oxide synthase (nc-NOS) in dynorphin (Dyn) A(1-17) spinal neurotoxicity and analgesia. METHODS: The cNOS activity in ventral and dorsal spinal cord in rats was measured with H-L-arginine conversion, and ncNOS immunoreactivity(IR) was observed with strepavidin-peroxidase immunohisto-chemistry. RESULTS: Intrathecal administration of Dyn A(1-17) produced dose-dependent paralysis of hindlimbs and tail as well as inhibition of tail flick (TF) and foot flinch (FF) reflexes. Dyn A(1-17) 10 nmol induced only transient paralysis and apparently reduced the ncNOS-IR in the superficial dorsal horn but did not induce any change of ncNOS-IR in the ventral horn cells as compared with saline control. Dyn A(1-17) 20 nmol produced permanent paraplegia with irreversible spinal cord damage, characterized by central and progressive necrosis. Dyn A(1-17) 20 nmol remarkedly induced the expression of ncNOS-IR in the ventral horn cells whereas inhibited ncNOS-IR in the superficial dorsal horn. Dyn A(1-17) 20 nmol also significantly increased the activities of cNOS in the ventral spinal cord but did not affect cNOS activities in the dorsal spinal cord. Intrathecal pretreatment with 7-nitroindazole (7-NI) 1 mumol, a selective ncNOS inhibitor 10 min prior to i.t. Dyn A(1-17) 20 nmol significantly ameliorated Dyn-induced neurological outcome, but TF and FF remained inhibited. 7-nitroindazole also significantly antagonized the increases of cNOS activities and ncNOS-IR in the ventral spinal cord at 4 h after i.t. Dyn A(1-17) 20 nmol, but did not affect or even potentiated Dyn-induced inhibition of cNOS activity and ncNOS-IR in the dorsal spinal cord. CONCLUSIONS: Over-expression or over-activation of ncNOS in the ventral spinal cord may be involved in Dyn spinal neurotoxicity, whereas as the reduction of ncNOS activities in the dorsal spinal cord might reflect Dyn spinal analgeisia or pain modulation.

Analgesics↗

PubMed1999

Selection and determination of specific and protective antigens of Mycobacterium tuberculosis.

OBJECTIVE: To select and identify the specific and protective antigens of Mycobacterium tuberculosis (M. tuberculosis) for searching a new approach to diagnose and treat tuberculosis. METHODS: Extract and culture filtrates of M. tuberculosis were obtained by ultrasonic treatment and millipore membrane filtration, respectively. The protein samples were tested with monoclonal antibody (MAb) and patient sera. The proteins showing positive reaction were sequenced on Beckman/LF 3200/peptide amino acid sequencer. RESULTS: Proteins of M. tuberculosis with molecular weight of 31 ku and 30 ku showed positive results when reacted with anti-M. tuberculosis MAb and sera of tuberculosis patients, but not with normal mouse serum and healthy human sera. N-terminal sequences of the 31 ku and 30 ku antigen were Ala Glu Val Asp Trp Leu Val Phe Ala Val and Phe Ser Arg Pro Gly Leu Pro Val Glu Try respectively. CONCLUSION: 31 ku and 30 ku proteins of M. tuberculosis are immune protective proteins. They play important or dominant roles in determination of immunorecognization.

Amino Acid Sequence↗

PubMed1999

Significance of anti-neutrophil cytoplasmic antibodies in patients with pauci-immune crescentic glomerulonephritis.

OBJECTIVE: To evaluate the significance of serum antineutrophil cytoplasmic antibodies (ANCAs) and the effects of immune suppressive treatments on its activity in patients with pauci-immune crescentic glomerulonephritis (PICGN). METHODS: Serum ANCAs and myeloperoxidase (MPO)-ANCA were detected by indirect immunofluorescence and enzyme-linked immunosorbent assay (ELISA) methods respectively, and the renal tissues infiltrating cells including CD4+, CD8+, CD68+ and PCNA+ cells were determined by four-layer peroxidase-antiperoxidase (PAP) method. The clinical manifestations, pathologic features and immune pathologic changes in patients with positive ANCAs were compared with that in patients with negative ANCAs. The effects of immune suppressive therapy on clinic and pathologic changes as well as ANCAs activity were also investigated in ANCAs positive and ANCAs negative patients. RESULTS: Both of clinic active manifestations such as the degree of hematuria, rapidly progressive renal failure and pathologic active features including segmental capillary necrosis and vasculitis were much common in patients with positive ANCAs as compared with that in patients with negative ANCAs. The number of infiltrating cells in renal tissue, especially CD4+ cells, was markedly higher in ANCAs positive patients than that in ANCAs negative patients. The effects of immune suppressive therapy were also much better in patients with positive ANCAs than that in patients with negative ANCAs. CONCLUSION: Serum ANCAs is not only a marker for diagnosis of systemic vasculitis, but also a sensitive predictor for evaluation of diseases' activity and treatment in patients with PICGN. The good effect of immune suppressive treatments on patients with PICGN is partially associated with the degree of ANCAs activity.

Adolescent↗

PubMed1999

[Helicobacter pylori in dental plaque of periodontitis and gastric disease patients].

OBJECTIVE: To investigate whether Helicobacter pylori(Hp) is a habitant in the oral cavity. METHODS: A polymerase chain reaction (PCR) assay with oligonucleotide primers homologous to a portion of the urease C and cytotoxin-associated gene A (cag A) of Hp was used to test for the presence of Hp in dental plaque. This assay was able to detect the expected 294 bp and 400 bp DNA fragments from as few as 100 Hp cells per reaction. Thirteen gastric disease patients (Group G) and 10 periodontitis patients (Group P) were recruited. A total of 276 supra- and subgingival plaque samples were collected, from 6 teeth in each subject for PCR assay. Clinical periodontal parameters including probing depth (PD), bleeding index (BI) and plaque index (PLI) of the sampled sites were recorded. RESULTS: In Group G, 11 of 13 patients had at least one Hp-positive plaque sample. 28.8% of the tested samples were urease C gene positive and 3.2% were positive for both urease C and cag A genes. All the 10 patients in Group P had at least one Hp-positive plaque sample. 49.2% of the tested samples were urease C gene positive and 3.3% were positive for both of the Hp genes. The prevalence of Hp was positively correlated with probing depth and bleeding index at the sampled sites. CONCLUSION: These results suggest that oral cavity is an ecological niche of Hp.

Adult↗

PubMed1999

[Pre- and post surgical orthodontic treatment of mandibular prognathism].

OBJECTIVE: To analyze the patients we treated in clinic through combined orthodontic-orthognathic surgery, and get some guidance for the future clinical work. METHODS: All 40 skeletal Class III malocclusion patients we analyzed were from joint clinic of our hospital. They aged from 17 to 38. RESULTS: The duration for presurgical orthodontic treatment was 9 months on average (2-25 months), and for postsurgical orthodontic treatment about 7.6 months on average (2-15 months). The duration for whole active treatment was 16 months on average (4-41 months). The objectives of presurgical orthodontic are: Alignment of dental arches, decompensation of anterior and posterior teeth, leveling of arches, and coordination of the width of the upper and lower arches. After presurgical orthodontic treatment, most of the patients could be treated by one piece surgery, which could simplify the surgical procedure and reduce the relapse rate of surgery. During the surgery, we modified the intermaxilary fixation wires. We used rigid rectangular stainless steel wires with Edgewise appliances as the fixation wires instead of conventional canine and molar bands with multiloop wires. The aims of the postsurgical orthodontic treatment are: closing residual spacing, extrusion of posterior teeth for correction of local openbite in premolars region, paralleling of the teeth, and adjustment of occlusion. CONCLUSION: Pre- and post-ssurgical orthodontic treatment is essential to the surgical treatment for mandibular prognathism.

Adolescent↗

PubMed1999

[Effect of Panax notoginseng saponin on Ca2+, CaM in craniocerebral injury].

OBJECTIVE: To explore the change of nerve cell Ca(2+)-overload, Ca(2+)-CaM and the effect of Panax Notoginseng saponin (PNS) on it in craniocerebral injury. METHODS: Blood and brain contents of Ca2+, CaM were examined by radio-immunoassay (RIA) and atomic absorption spectrometry(AAS), and effect of PNS on these parameters was observed in craniocerebral injury rabbits. RESULTS: The levels of Ca2+ and CaM in blood and those in brain were significantly positively correlated. PNS could reduce Ca2+ and CaM contents in blood and in cerebral tissue. CONCLUSION: PNS could block the Ca(2+)-overload and Ca(2+)-CaM complex production in nerve cell after cranial cerebral injury, thereby to protect the injured brain in a certain degree. Blood CaM level is an objective index for assessment of Ca(2+)-overload in nerve cell.

Animals↗

PubMed1999

[Clinical protocols for the treatment of severe acute pancreatitis].

OBJECTIVE: To set up principles for the treatment of severe acute pancreatitis (SAP). METHODS: The therapeutic principles and results of SAP in three periods were analyzed. Period I (1980 - 1990) was characterized by early surgical intervention supplemented with integrated traditional and western medical therapy, period II (1991 - 1993) by integrated traditional and western medical therapy supplemented with surgery for early complications, and period III (1994 - 1997) by integrated traditional and western medical therapy supplemented with surgery for local infectious complications only. RESULTS: Because of the improvement of intensive care, the operation rates kept declining in the three periods. They were 77.59%, 54.55% and 29.55% with a mortality rate of 40.52%, 17.17% and 11.36%, respectively. CONCLUSIONS: Integrated traditional and western medicine has been effective in most SAP patients, and surgery is indicated only for late complications such as necrotizing infection. Early surgery should be restricted.

Adolescent↗

PubMed1999

[Expression in Lactococcus lactis of catalytically active phenylalanine ammonia-lyase from parsley].

The phenylalanine ammonia-lyase (PAL) cDNA of parsley (Petroselinum crispum) was subcloned into constitutive expression vector pMG36e downstream of the P32 promoter. The resulting plasmid pMG36ePAL was introduced into Lactococcus lactis subsp. lactis MG1363 by electroporation. The recombinant strain showed its PAL activity conversing the L-phenylalanine in the culture medium into trans-cinnamic acid. A new secretory vector pXHS was constructed by recombination of pMG36e with a Lactococcal usp45 secretion leader coding sequence and a translational coupling sequence. Then the pXHSPAL was constructed and used for expression of PAL in L. lactis, the PAL activity was also detectable. The L. lactis dnaJ promoter sequence was cloned and used to construct a heat inducible vector pXHJ. PAL cDNA was cloned into pXHJ and the L. lactis IL1403 was transformed with the recombinant plasmid pXHJPAL. After a heat shock from 30 degrees C to 37 degrees C, the PAL activity of the pXHJPAL strain could increase approximately onefold. The prospect of using these engineering L. lactis strains for PKU therapy was also discussed.

Amino Acid Sequence↗

PubMed1998

Characterization of cytochrome c-556 from the purple phototrophic bacterium Rhodobacter capsulatus as a cytochrome-c peroxidase.

A cytochrome c-556 was purified from Rhodobacter capsulatus and the complete amino acid sequence was determined. It contains 328 amino acid residues and two typical heme-binding sites at cysteine residues 54 and 57 and at residues 200 and 203. It is homologous to the family of bacterial cytochrome c peroxidases (BCCP) with 69% identity to Paracoccus denitrificans BCCP and 60% identity to Pseudomonas aeruginosa BCCP for which there is a three-dimensional structure. There is lesser similarity to the mauG gene products from methylotrophic bacteria which are thought to be involved in biosynthesis of the quinone cofactor of methylamine dehydrogenase. Translated genes from Escherichia coli and Helicobacter pylori are also related to the bacterial cytochrome c peroxidases. The divergence of this family of proteins is reflected in the fact that the reported sixth heme ligands are not conserved, except in Pseudomonas, Rhodobacter and Paracoccus. This suggests that homologs of BCCP may fold differently and/or may not have the same enzymatic activity as the prototypic protein from Ps. aeruginosa. We found that the Rb. capsulatus BCCP is active with both Rb. capsulatus cytochrome c2 and with horse cytochrome c as substrates (Km values 60 microm and 6 microm, respectively). The turnover number was 40 s(-1) and the Km for peroxide was 33 microm. We have thus confirmed that the Rb. capsulatus protein is a cytochrome c peroxidase.

Amino Acid Sequence↗

PubMed1998

Chemokine receptor CCR5 functionally couples to inhibitory G proteins and undergoes desensitization.

Chemokine receptor CCR5 is not only essential for chemotaxis of leukocytes but also has been shown to be a key coreceptor for HIV-1 infection. In the present study, hemagglutinin epitope-tagged human CCR5 receptor was stably expressed in Chinese hamster ovary cells or transiently expressed in NG108-15 cells to investigate CCR5-mediated signaling events. The surface expression of CCR5 was confirmed by flow cytometry analysis. The CCR5 agonist RANTES stimulated [35S]GTPgammaS binding to the cell membranes and induced inhibition on adenylyl cyclase activity in cells expressing CCR5. The effects of RANTES were CCR5 dependent and could be blocked by pertussis toxin. Furthermore, overexpression of Gialpha2 strongly increased both RANTES-dependent G-protein activation and inhibition on adenylyl cyclase in cells cotransfected with CCR5. These data demonstrated directly that activation of CCR5 stimulated membrane-associated inhibitory G proteins and indicated that CCR5 could functionally couple to G-protein subtype Gialpha2. The abilities of CCR5 to activate G protein and to inhibit cellular cAMP accumulation were significantly diminished after a brief prechallenge with RANTES, showing rapid desensitization of the receptor-mediated responsiveness. Prolonged exposure of the cells to RANTES caused significant reduction of surface CCR5 as measured by flow cytometry, indicative of agonist-dependent receptor internalization. Our data thus demonstrated that CCR5 functionally couples to membrane-associated inhibitory G proteins and undergoes agonist-dependent desensitization and internalization.

Adenylate Cyclase Toxin↗

PubMed1998

NMR solution structure of the 21 kDa chaperone protein DnaK substrate binding domain: a preview of chaperone-protein interaction.

The solution structure of the 21 kDa substrate-binding domain of the Escherichia coli Hsp70-chaperone protein DnaK (DnaK 386-561) has been determined to a precision of 1.00 A (backbone of the beta-domain) from 1075 experimental restraints obtained from multinuclear, multidimensional NMR experiments. The domain is observed to bind to its own C-terminus and offers a preview of the interaction of this chaperone with other proteins. The bound protein region is tightly held at a single amino acid position (a leucyl residue) that is buried in a deep pocket lined with conserved hydrophobic residues. A second hydrophobic binding site was identified using paramagnetically labeled peptides. It is located in a region close to the N-terminus of the domain and may constitute the allosteric region that links substrate-binding affinity with nucleotide binding in the Hsp70 chaperones.

Amino Acid Sequence↗

PubMed1998

Transmission multilayer polarizers for use in the 55-90 eV region.

Free-standing Al/YB(6) and Mo/Si transmission multilayer polarizers have been developed for use in the photon energy regions 55-72 eV and 72-90 eV, respectively, to improve the degree of polarization of synchrotron radiation light from beamline monochromators. The polarizance (polarizing ability) and transmittance of the Al/YB(6) multilayer for unpolarized light at 64 eV were 77% and 3.4%, respectively, and the polarizance and transmittance of the Mo/Si multilayer at 80 eV were 79% and 2.2%, respectively. By using the Mo/Si polarizer, the degree of polarization of the monochromated light at BL8B1 of UVSOR was increased from 95 to 99% in the 78-84 eV region.

Journal Article↗

PubMed1998

Elucidation of the chain conformation in a glassy polyester, PET, by two-dimensional NMR

The chain conformation of glassy poly(ethylene terephthalate) (PET) was characterized by two-dimensional double-quantum nuclear magnetic resonance (NMR). In amorphous carbon-13-labeled PET, the statistics of the O-13CH2-13CH2-O torsion angle were determined, on the basis of the distinct shapes of the two-dimensional NMR patterns of trans and gauche conformations. In crystalline PET, the trans content is 100 percent, but in the amorphous PET it is only 14 percent (+/-5 percent). An average gauche torsion angle of 70 degrees (+/-9 degrees) was obtained. Implications for materials properties of polyesters are discussed.

Journal Article↗