PubMed Health⌕ Search

Biomedical subjects

Y Q Wu

Publications and source records attributed to Y Q Wu.

At least 37 records · Page 2Linked to original sources
PubMed2000

[Studies on single cell cloning of Ginkgo biloba L].

OBJECTIVE: To investigate the relations of the productivity stability of to the homogenization of Ginkgo biloba cells by single cell clones. METHOD: Using plant single cell plate culture technique. RESULTS: Adding 500 ml.L-1L-glutamine in the medium increased greatly the cell plating efficiency (PE), and within the range 0.5-5.0 x 10(4) Cell.ml-1 of the initial cell density, the PE increased with the increment of the cell density. Of the 48 cell clones obtained, the GKB content in G-22 clone reached 0.099%; and most of the clones remain stable in growth and GKB production during subcultures. CONCLUSION: During the cell and tissue culture of G. biloba, the application of plant single cell cloning technique helps to a certain extent solve the problem of productivity instability of ginkgolide.

Cell Line↗
PubMed2000

[Embolization in arteriovenous malformations of maxillofacial region with PVA].

OBJECTIVE: To evaluate the embolization of arteriovenous malformations of the maxillofacial region with PVA. METHODS: 8 cases (male:3, female:5) of arteriovenous malformations of the maxillofacial region comprised this study group. The embolic material used was PVA (Polyvinyl Alcohol Foam) particles (250-500 microm) injected using 4.0 to 3.0 French-size catheters, catheterized selectively in the feeding pedicles of the AVM under the guidance of DSA machine (PHILIPS V3000). RESULTS: Five patients were embolized an a single session, and three patients needed two sessions. Immediate angiographical results showed total disappearance of the AVMs in all patients. Swelling, pulsation, and bruit were disappeared after embolization. Pericoronal oozing of blood and acute arterial bleeding was controllable. Local pain, swelling,and low-grade fever usually lasted from 3 to 7 days after embolization. CONCLUSION: The embolization of arteriovenous malformations of the maxillofacial region with PVA is effective and safe, and the longer follow-up is expected.

English Abstract↗
PubMed1999

Molecular refinement of the 1p36 deletion syndrome reveals size diversity and a preponderance of maternally derived deletions.

The deletion of chromosome 1p36 is a newly recognized, relatively common contiguous gene deletion syndrome with a variable phenotype. The clinical features have recently been delineated and molecular analysis indicates that the prevalence of certain phenotypic features appears to correlate with deletion size. Phenotype/genotype comparisons have allowed the assignment of certain clinical features to specific deletion intervals, significantly narrowing the regions within which to search for candidate genes. We have extensively characterized the deletion regions in 30 cases using microsatellite markers and fluorescence in situ hybridization analyses. The map order of 28 microsatellite markers spanning the deletion region was obtained by a combination of genotypic analysis and physical mapping. The deletion region was divided into six intervals and breakpoints were found to cluster in mainly two regions. Molecular analysis of the deletions showed that two patients had complex re-arrangements; these cases shared their distal and proximal breakpoints in the two common breakpoint regions. Of the de novo deletions ( n = 28) in whichparental samples were available and the analysis was informative ( n = 27), there were significantly morematernally derived deletions ( n = 21) than paternally derived deletions ( n = 6) (chi1(2) = 8.35, P < 0.0001). Phenotype/genotype correlations and refinements of critical regions in our naturally occurring deletion panel have delineated specific areas in which to focus the search for the causative genes for the features of this syndrome.

Chromosome Aberrations↗
PubMed1999

[The expression of CD44s and CD44v6 in human salivary adenoid cystic carcinoma ]

OBJECTIVE:The present study was to investigate the expression of CD44s and CD44v6 in human salivary adenoid cystic carcinoma (ACC) and to discuss the relationship between the expression of the proteins and the biological characteristic of ACC.METHODS:Formalin fixed,paraffin embedded sections in 10 cases of normal salivary glands and 50 cases of human salivary ACC were examined using immunostaining for CD44s and CD44v6.RESULTS:(1)Positive signals of CD44s and CD44v6 were detected in all the specimens of normal salivary glands.Positive signals of CD44s and CD44v6 were detected in 29(58%) and 35(70%) of the 50 cases of ACC.(2)The expression of CD44s and CD44v6 in the solid pattern of ACC was significantly less than that in the cribriform and tubular pattern of ACC(P<0.05).(3)Positive CD44s staining was detected in 3(13.6%) of the 22 ACC primary sites which had a local recurrence after operation.CONCLUSION:(1)Adhesion molecules including CD44s and CD44v6 may contribute to maintain the normal structures in salivary gland tissues.(2)T he down-regulation or loss of CD44s expression was contributed to the recurrence of human salivary ACC and CD44s could be regarded as one of the factors to evaluate the prognosis of ACC patients.

Journal Article↗
PubMed1999

[The expression of E-cadherin-catenin complex in human salivary adenoid cystic carcinoma]

OBJECTIVE: The aim of this study was to investigate the expression of the E-cadherin-catenin(E-cad-cat) complex in human salivary adenoid cystic carcinoma(ACC) and determine the effects of E-cad-cat expression on tumor differentiation,metastasis and invasion as well as their clinical significance. METHODS:The expression of adhesion molecules,which included E-cadherin,alpha-catenin and beta-catenin,in 10 cases of normal salivary glands,50 cases of human salivary ACC was investigated by immunohistochemistry.RESULT:Co-expression of E-cadherin,alpha-catenin and beta-catenin was detected in 29(58%) of the 50 ACC specimens.Positive staining of E-cad-cat complex was detected in 7(39%) of the 18 ACC primary sites which had aggressive phenotype of nerve and vasculature.CONCLUSION:Strong positive signals of E-cad-cat complex were showed in normal salivary glands,and the down regulation expression was observed in ACC cases,The expression of E-cad-cat complex was associated with a more aggressive phenotype on nerve and vasculature.No association with various histopathologic subtypes was found;Down-regulation of E-cad-cat complex may be associated with canceration of normal salivary glands.

Journal Article↗
PubMed1999

[The expression of adhesion molecules in human salivary adenoid cystic carcinoma cell line]

OBJECTIVE:The aim of this study was to investigate the expression of the adhesion molecules in human salivary adenoid cystic carcinoma(ACC) cell lines (ACC-2 line and ACC-M strain) which had different metastatic ability.METHODS:The expression of adhesion molecules,which included CD44s,CD44v6,E cadherin,alph-catenin and beta-catenin in two human salivary ACC cell lines and Scid mice neoplasm models was investigated by immunohistochemistry. RESULTS: (1)Positive staining of adhesion molecules in lung metastatic foci of ACC was higher than that in subcutaneous implanted tumor mass.(2)The growing of ACC-M was slower in the cells of abdominal cavity implanted tumor,and also the differentiation of the former was better than the latter.(3)Weaker Positive staining of CD44v6 in ACC cells in vitro was showed,however,no positive staining was detected in lung metastatic foci cells of ACC M and the cells of subcutaneous tumor.CONCLUSION: The expression of CD44s in ACC cells was influenced by cell differentiation,and may affect the growth conditions;The expression levels of E cad/cat was positively correlative to the differentiation of ACC tumor cells;No significant correlation was revealed between the expression of CD44v6 and metastatic ability of ACC.

Journal Article↗
PubMed1998

Delineation of the common critical region in Williams syndrome and clinical correlation of growth, heart defects, ethnicity, and parental origin.

Williams syndrome (WS) is a neurodevelopmental disorder with a variable phenotype. Molecular genetic studies have indicated that hemizygosity at the elastin locus (ELN) may account for the cardiac abnormalities seen in WS, but that mental retardation and hypercalcemia are likely caused by other genes flanking ELN. In this study, we defined the minimal critical deletion region in 63 patients using 10 microsatellite markers and 5 fluorescence in situ hybridization (FISH) probes on chromosome 7q, flanking ELN. The haplotype analyses showed the deleted cases to have deletions of consistent size, as did the FISH analyses using genomic probes for the known ends of the commonly deleted region defined by the satellite markers. In all informative cases deleted at ELN, the deletion extends from D7S489U to D7S1870. The genetic distance between these two markers is about 2 cM. Of the 51 informative patients with deletions, 29 were maternal and 22 were paternal in origin. There was no evidence for effects on stature by examining gender, ethnicity, cardiac status, or parental origin of the deletion. Heteroduplex analysis for LIMK1, a candidate gene previously implicated in the WS phenotype, did not show any mutations in our WS patients not deleted for ELN. LIMK1 deletions were found in all elastin-deletion cases who had WS. One case, who has isolated, supravalvular aortic stenosis and an elastin deletion, was not deleted for LIMK1. It remains to be determined if haploinsufficiency of LIMK1 is responsible in part for the WS phenotype or is simply deleted due to its close proximity to the elastin locus.

Chromosomes, Human, Pair 7↗
PubMed1997

Background exposure of urban populations to lead and cadmium: comparison between China and Japan.

OBJECTIVES: To assess and compare the background exposure of the general population to lead (Pb) and cadmium (Cd) in China and in Japan. METHODS: Food duplicates and peripheral blood samples were collected from nonoccupationally exposed subjects, viz 202 Chinese women in four Chinese cities (Beijing, Shanghai, Nanning, and Tainan) and 72 Japanese women in three Japanese cities (Tokyo, Kyoto, and Sendai) in the years 1993-1995. Wet-ashing and graphite furnace atomic absorption spectrometric methods were used for the determination of Pb and Cd levels in food and blood samples. RESULTS: Geometric mean (GM) dietary Pb intake (25.8 micrograms/day) and the GM Pb concentration in blood (56.7 micrograms/l) in Chinese were significantly higher than in Japanese women (11.6 micrograms/day in food and 32.1 micrograms/l in blood), whereas Cd in food (32.1 micrograms/day) and Cd in blood (1.92 micrograms/l) in Japanese were significantly higher than in Chinese women (9.9 micrograms/day in food and 1.07 micrograms/l in blood). The intake of Pb and Cd via boiled rice accounted for 3.6% and 31.1% of the total dietary burden in Chinese, and 12.1% and 32.7% in Japanese, respectively. The Cd burden was acquired almost exclusively through the dietary route, whereas the Pb burden came from both air and food, especially in the case of the Chinese population. CONCLUSIONS: The background Pb exposure in the Chinese population was higher than that in the Japanese population, whereas Cd exposure was lower in Chinese women than in their Japanese counterparts.

Air Pollutants↗
PubMed1997

Measurement of synovial tumor necrosis factor-alpha in diagnosing emergency patients with bacterial arthritis.

Because of the high morbidity and mortality in patients with bacterial arthritis, rapidly and correctly diagnosing this critical condition is a challenge to emergency clinicians. Synovial fluid samples were obtained from 75 patients with arthritis disorders who presented to an emergency service, and levels of tumor necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1 beta), and interleukin-6 (IL-6) were measured. Twenty patients with culture-proven bacterial arthritis had higher levels of synovial TNF-alpha than patients with osteoarthritis or with inflammatory arthritis, including gouty arthritis, rheumatoid arthritis, reactive arthritis, and lupus arthritis. There was a good sensitivity for synovial TNF-alpha level in diagnosing patients with bacterial arthritis. Nearly 100% of patients with bacterial arthritis had elevated synovial TNF-alpha levels. However, synovial IL-1 beta and IL-6 levels failed to discriminate bacterial arthritis from other inflammatory arthritis. Measurement of synovial TNF-alpha level may be useful as a diagnostic aid in emergency patients with bacterial arthritis disorders.

Adult↗
PubMed1997

Retardation of pain development: a case of recovery from congenital insensitivity to pain.

Congenital analgesia is a rare genetic disorder. We report here that a 12-year-old boy was able to recover from congenital insensitivity to pain. Neurological examinations revealed that there was a 'stocking' distribution of pain decrement on the lower extremities under the patient's knee joints. Magnetic Resonance Imaging (MRI) of his brain showed gyrus thinning with sulcus widening at both sides of the parietal lobe. Southern blot hybridization probed with cDNAs of various opioid receptors did not detect any significant abnormality. Our results suggest that this rare case may not be genetically determined.

Arthropathy, Neurogenic↗
PubMed1996

A low-barrier hydrogen bond in subtilisin: 1H and 15N NMR studies with peptidyl trifluoromethyl ketones.

The N delta 1 proton of His 64 forms a hydrogen bond with Asp 32, as part of the catalytic triad in serine proteases of the subtilisin family. His 64 in subtilisin has been studied by 1H and 15N NMR spectroscopy in the presence and absence of peptidyl trifluoromethyl ketones (TFMKs) that are transition state analog inhibitors. For subtilisin Carlsberg, the downfield resonance of the imidazolium N delta 1 proton is approximately 18.3 ppm and the D/H fractionation factor is 0.55 +/- 0.04 at pH 5.5 (11 degrees C), and 0.63 +/- 0.04 (5 degrees C) and 0.68 +/- 0.04 at pH 6 (11 degrees C). In the complex between subtilisin Carlsberg and Z-L-leucyl-L-leucyl-L-phenylalanyltrifluoromethyl ketone (Z-LLF-CF3) at pH values between 6.5 and 10.6, His 64 remains positively charged, and the D/H fractionation factor of its N delta 1 proton is 0.85 +/- 0.05. In the complex between a subtilisin variant from Bacillus lentus and Z-LLF-CF3, the proton resonance at 18.8 ppm is correlated with a 15N resonance at 197.6 ppm downfield from liquid NH3 with a 1JNH of 81 Hz. The chemical shifts of subtilisin complexes with peptidyl TFMKs are among the most downfield shifts reported for any protein. At pH 9.5, His 64 is neutral and the D/H fractionation factor increases to 1.2 with a chemical shift of 15.0. His 64 is positively charged in the free enzyme at low pH, the inhibitor hemiketal complex at neutral pH, and the transition state for amide bond hydrolysis. These data thus provide indirect evidence for the presence of a low-barrier hydrogen bond in the catalytic mechanism of subtilisin proteases.

Bacterial Proteins↗
PubMed1996

From good substrates to good inhibitors: design of inhibitors for serine and thiol proteases.

Serine and thiol proteases react with peptide substrates to form an acyl-enzyme. We have synthesized inhibitors which are pseudo-substrates and react with the proteases to generate acyl-enzymes which hydrolize slowly. This is achieved by incorporating an electron-donating group near the carbonyl group of inhibitors I [Ac-Phe--C(O)NH--NH--C(O)X] and II [benzyl-O-C(O)-psiAla-Leu-ArgOMe]. The acyl-enzymes derived from the reaction of I with papain and II with chymotrypsin hydrolyze with t1/2 of 12 and 1 h, respectively. The increased electron density on the carbonyl group of the inhibitor also reduces the rate of acyl-enzyme formation. Components were incorporated into the inhibitor which interact with the leaving group binding site (S' subsite) and which accelerate the rate of reaction of inhibitor with enzyme. For inhibitor I, X = NH(CH3), k(on) < 0.13 M(-1) s(-1) for the reaction papain, but if X = psiLeu(CH3)2,k(on) =10(5) M(-1) s(-1). Similar results were obtained with II and chymotrypsin. Concomitant with acyl-enzyme formation, X is released and a slowly hydrolyzing acyl-enzyme remains.

Cysteine Proteinase Inhibitors↗
PubMed1996

Human testis specifically expresses a homologue of the rodent T lymphocytes RT6 mRNA.

A human homologue of the rodent T cell mono ADP-ribosyl transferase RT6 mRNA was identified by a systematic analysis of human testis transcripts. This messenger encodes for a precursor protein of 367 aa (MW: 41.5 kDa) which exhibits a peptide signal, consensus domains for mono ADP-ribosyl transferase and a C-terminal part characteristic of glycophosphatidyl inositol anchored protein. This mRNA, transcribed from a gene localized in 4q13-q21, is not expressed in white blood cells but is specific for human testis in which it is likely to correspond to a new ADP-ribosyl transferase.

ADP Ribose Transferases↗
PubMed1996

Blood lead levels in Taiwanese adults: distribution and influencing factors.

Five-thousand nine-hundred thirteen Taiwanese adults were selected by multistage sampling methods to investigate environmental lead exposure in Taiwan. The blood specimens were distributed to six laboratories for blood lead levels (BLL) measurement. The mean BLL of the 5913 Taiwanese adults was 8.28 +/- 5.39 microg/dl, with a maximum level of 57.6 microg/dl. The median was 7.0 microg/dl and 90th percentile was 15.0 microg/dl. BLLs were associated with gender, ethnic group, education level, smoking, alcohol consumption, herbal drug consumption, milk consumption, sources of drinking water, level of urbanization, and occupational lead exposure. These results showed that BLLs in Taiwanese adults were stable during the 2-year study. Most of the influencing factors were consistent with other studies, while local risk factors, such as Chinese herbal drug consumption are important ways of preventing the general population from overexposure to lead.

Adolescent↗
PubMed1996

Three-year survey of blood lead levels in 8828 Taiwanese adults.

The purpose of this study was to investigate environmental lead exposure in the general Taiwanese population. A total of 8828 Taiwanese adults selected by a multistage sampling method were investigated. Characteristics of the participants were ascertained by questionnaire and 10 ml venous blood was drawn by public health nurses. The blood specimens were distributed to six laboratories for blood lead level (BLL) measurement. A quality control program was applied during the analysis of the BLLs in order to improve precision and accuracy. The arithmetic mean BLL of the 8828 Taiwanese adults was 7.70 +/- 5.23 micrograms/dl, with a maximal level of 69.1 micrograms/dl. The median was 6.5 micrograms/dl and the 90th percentile was 14.0 micrograms/dl. After logarithmic transformation, the geometric mean was 1.84 +/- 0.67 microgram/dl. This study also found that elevated BLLs were associated with certain personal characteristics, i.e., gender, ethnic group, and education level; life-style factors, such as smoking, alcohol consumption, Chinese herbal drug consumption, milk consumption, and sources of drinking water; residential location, i.e., level of urbanization; and occupational history of lead exposure. However, age, floor level of residence, distance from house to road, and betel nut consumption were not associated with elevated BLLs. These results showed that BLLs in the Taiwanese population were not higher than those in developed and developing countries. Most of the influencing factors were also found in other studies; however, local factors such as ethnic group, Chinese herbal drug consumption, and sources of drinking water are important considerations in Taiwan when examining ways to prevent overexposure to lead in the general population.

Adult↗
PubMed1996

Proteolytic activity directed toward pigment epithelium-derived factor in vitreous of bovine eyes. Implications of proteolytic processing.

PURPOSE: Experiments were designed to identify proteolytic activities that cleave pigment epithelium-derived factor (PEDF), a member of the serpin (serine protease inhibitor) family. METHODS: Proteins in vitreous humor from bovine eyes were analyzed by Western blot with antiserum to human recombinant PEDF protein. Protein fractionation was by ammonium sulfate saturation and by S-Sepharose column chromatography. Proteolytic activities were determined by gelatin zymography and by solution assays against PEDF or chromogenic peptide substrates. RESULTS: PEDF protein was identified and purified to near homogeneity from vitreous humor of bovine eyes. Limited proteolysis showed that the vitreal protein has a protease-sensitive region at its serpin-exposed peptide loop. Proteolytic activities that cleave the PEDF 49.5 kDa-polypeptide were identified only when proteins from these extracts were separated by 45% to 70% ammonium sulfate fractionation (P70). The degradation product had an apparent molecular weight of 46 kDa. This result is consistent with cleavage at the serpin-exposed loop. The PEDF-cleavage activity in P70 was inhibited specifically by the serine protease inhibitor 4-(2-aminoethyl)-benzenesulfonyl fluoride (AEBSF), but not by aprotinin, EDTA, or pepstatin. The vitreal P70 extracts contained 49- and 53-kDa gelatinolytic activities that also were inhibited by AEBSF and not by EDTA, aprotinin, or pepstatin. The PEDF-cleavage activity did not hydrolyze substrates for thrombin, factor Xa, alpha-chymotrypsin, trypsin, or plasmin, nor did it immunoreact with antibody to urokinase plasminogen activator. CONCLUSIONS: These data indicated that vitreous has a serine-proteolytic activity associated with a novel 49/53-kDa enzyme that cleaves the PEDF protein in a serpinase fashion. In addition to cleavage in vitro, these proteases might play a role in modulating PEDF in vivo.

Animals↗