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Biomedical subjects

C C Wu

Publications and source records attributed to C C Wu.

At least 37 records · Page 2Linked to original sources
PubMed2004

Cystic fibrosis transmembrane conductance regulator gene screening and clinical correlation in Taiwanese males with congenital bilateral absence of the vas deferens.

BACKGROUND: In Taiwan, an area with a very low incidence of cystic fibrosis (CF), we first screened for the most common mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene and looked for clinical correlations in 27 patients with clinically diagnosed congenital bilateral absence of the vas deferens (CBAVD). METHODS AND RESULTS: The clinical results showed that none of the 27 patients had CF symptoms. We did not detect any definite renal anomaly ultrasonographically. Mutation analysis was carried out on these 27 cases and 46 normal fertile males as controls. No mutations of Delta F508 or R117H were identified in any of the samples analysed. In the screening of IVS8-poly T, five of the 27 CBAVD patients showed the homozygous genotype for 5T/5T, 14 showed the heterozygous genotype for 5T/7T and eight showed the homozygous genotype for 7T/7T. The frequency of 5T alleles was 44.4%, which was significantly higher than in the 46 normal fertile males, for which there was a 5T frequency of 5.4%. CONCLUSIONS: The absence of major mutations of CFTR genes could be related to the much lower CF incidence in Taiwan. Further investigations into differences in the mutation spectrum of other CFTR genes are needed for a better understanding of the development of Taiwanese-Oriental CBAVD.

Alleles↗
PubMed2004

Mycobacterium avium subsp. paratuberculosis fibronectin attachment protein facilitates M-cell targeting and invasion through a fibronectin bridge with host integrins.

Efficient attachment and ingestion of Mycobacterium avium subsp. paratuberculosis by cultured epithelial cells requires the expression of a fibronectin (FN) attachment protein homologue (FAP-P) which mediates FN binding by M. avium subsp. paratuberculosis. Invasion of Peyer's patches by M. avium subsp. paratuberculosis occurs through M cells, which, unlike other intestinal epithelial cells, express integrins on their luminal faces. We sought to determine if the interaction between FAP-P of M. avium subsp. paratuberculosis and soluble FN enabled targeting and invasion of M cells by M. avium subsp. paratuberculosis in vivo via these surface integrins. Wild-type and antisense FAP-P mutant M. avium subsp. paratuberculosis strains were injected alone or coinjected with blocking peptides or antibodies into murine gut loops, and immunofluorescence microscopy was performed to assess targeting and invasion of M cells by M. avium subsp. paratuberculosis. Nonopsonized M. avium subsp. paratuberculosis preferentially invaded M cells in murine gut loops. M-cell invasion was enhanced 2.6-fold when M. avium subsp. paratuberculosis was pretreated with FN. Invasion of M cells by the antisense FAP-P mutant of M. avium subsp. paratuberculosis was reduced by 77 to 90% relative to that observed for the control strains. Peptides corresponding to the RGD and synergy site integrin recognition regions of FN blocked M. avium subsp. paratuberculosis invasion of M cells by 75 and 45%, respectively, whereas the connecting segment 1 peptide was noninhibitory. Antibodies against the alpha5, alphaV, beta1, and beta3 integrin subunits inhibited M-cell invasion by 52 to 73%. The results indicate that targeting and invasion of M cells by M. avium subsp. paratuberculosis in vivo is mediated primarily by the formation of an FN bridge formed between FAP-P of M. avium subsp. paratuberculosis and integrins on M cells.

Adhesins, Bacterial↗
PubMed2003

One-stage revision surgery to treat hip infected nonunion after stabilization with a sliding compression screw.

INTRODUCTION: Extracapsular hip infected nonunion after stabilization with a sliding hip screw (SCS) is uncommon and a convincing treatment method has not yet been reported in the literature. PATIENTS AND METHODS: Thirteen consecutive patients who sustained such a disability were treated with removal of SCS, local radical debridement, vancomycin powder with or without gentamicin solution application, re-insertion of a new SCS, and autogenous cancellous bone grafting. Postoperatively, ambulation with regulated weight bearing was encouraged as early as possible. Infectious microorganisms in 76% (10/13) of the lesion sites were oxacillin-resistant staphylococcus aureus (ORSA). RESULTS: Twelve patients were followed-up for at least 2 years (range, 2~6 years; median, 4 years) and all nonunions healed. The union rate was 100% (12/12) with a median union period of 4 months (range, 3~6 months). No wound infection recurred at the last follow-up. The satisfactory rate of hip function was 92% (11/12, P<0.001). CONCLUSIONS: We, therefore, recommend this surgical procedure to treat all patients with a similar disability because of its high success rate and low complication rate.

Adolescent↗
PubMed2003

Tracing developing pathways in the brain: a comparison of carbocyanine dyes and cholera toxin b subunit.

The present study examined the efficiency of fluorescent carbocyanine dye 1,1'-dioctadecyl-3,3,3',3'-tetramethylinodocarbocyanine perchlorate and cholera toxin B subunit in tracing the crossed tectal projection to the nucleus rotundus of the thalamus (tectorotundal pathways) of paraformaldehyde-fixed and living chick embryos. The tracers were injected into the optic tectum under three experimental conditions (carbocyanine postfix, carbocyanine in vivo, and cholera toxin B subunit in vivo) and the anterograde transport of the nucleus rotundus was monitored and compared. In the carbocyanine postfix method, small crystals of carbocyanine dye were inserted into the tectum of paraformaldehyde-fixed embryos. A 6-month post-insertion period was required to label the crossed tectorotundal pathway. Results showed that tectal neurons did not begin to innervate the ipsilateral nucleus rotundus until embryonic day 9 and the contralateral nucleus rotundus until embryonic day 17. This slow progression of labeling through the crossed tectal projection resulted in significant contrast of the labeling between the ipsilateral and contralateral nuclei rotundus. In the carbocyanine in vivo method, a small volume of carbocyanine dye solution was injected into the tectum of living embryos. A 8- to 12-h survival period was sufficient enough to label the tectorotundal pathway. By embryonic day 8, the labeled axons terminated in the ipsilateral nucleus rotundus and the crossed tectorotundal projection was first detected by embryonic day 10. Similarly, in the cholera toxin B subunit in vivo method, a small volume of cholera toxin B subunit solution was injected into the tectum of living embryos. After a 6- to 10-h survival period, heavily labeled axons were found to innervate bilaterally the nucleus rotundus by embryonic day 8. This appeared to be the earliest schedule for detecting the crossed tectorotundal projection, compared with that of both the postfix and in vivo methods of carbocyanine dye. Based on the differences in the detectability of the crossed tectorotundal projection between the postfix and in vivo methods, the present data suggest that the former method is of limited purpose for labeling tectal collaterals during embryogenesis. Moreover, given the rapid transport rate and absence of photobleaching, which is often seen when using carbocyanine dye, the cholera toxin B subunit in vivo method appears to be the tracer of choice for investigating embryonic pathways.

Animals↗
PubMed2003

Reaming bone grafting to treat tibial shaft aseptic nonunion after plating.

OBJECTIVE: To investigate the effects of using intramedullary reaming to provide cancellous bone graft, and reamed intramedullary nail stabilisation to provide fragment stability on treating tibial shaft aseptic nonunions after plating. METHODS: 31 consecutive patients with tibial shaft aseptic nonunions after plating were prospectively treated. Indications for this technique included a tibial shaft nonunion with an inserted plate, a fracture level fit for traditional or locked nail stabilisation, absence of suspected infection and segmental bony defect at the time, and shortening of less than 2 cm. The plate was removed and the marrow cavity was reamed as widely as possible. A stable unlocked or locked intramedullary nail was then inserted. No extra cancellous bone graft was supplemented. RESULTS: 28 patients were followed up for a median period of 2.2 years (range, 1.0-5.2 years). All patients achieved solid union. The median union period was 4.5 months (range, 3.0-7.5 months). There were no significant complications. CONCLUSION: When reamed intramedullary nails are used to treat tibial shaft aseptic nonunions after plating, supplemented cancellous bone grafting can be spared. Despite the technique being simplified, the success rate is high. We therefore recommend its wide use to treat all suitable cases.

Adult↗
PubMed2003

Minimally displaced intra-capsular femoral neck fractures in the elderly--comparison of multiple threaded pins and sliding compression screws surgical techniques.

PURPOSE: To determine the outcome of treatment for minimally displaced femoral neck fractures using multiple threaded pins versus sliding compression screws for internal fixation. METHODS: The medical records of 62 consecutive elderly patients with minimally displaced intra-capsular femoral neck fractures who underwent internal fixation of the fracture (37 with multiple threaded pins, and 25 with sliding compression screws) were reviewed. Clinical and radiological assessment of fracture healing at follow-up visits were noted. RESULTS: In the 55 patients seen for follow-up at 3 months, 21.9% (n=7) of those treated by pinning demonstrated non-union of the fracture, and 0% of fractures treated with sliding compression screws (p=0.02). 46 patients were seen for follow-up at one year, with 10% (n=2) of those treated with sliding compression screws found to have osteonecrosis of the femoral head. The 2 fractures in the group treated by pinning demonstrating non-union at 3 months failed to unite by one year (p=0.11). 34 patients were seen for follow-up for at least 2 years, with no additional complications noted. CONCLUSION: Using sliding compression screws to treat minimally displaced femoral neck fractures can achieve a higher union rate than using pinning. The reason may be the better stability in the osteoporotic bone. However, osteonecrosis of the femoral head may occur with use of sliding compression screws because of greater intramedullary vascular damage as a result of wider reaming.

Aged↗
PubMed2002

Specific mucosal IgA immunity in turkey poults infected with turkey coronavirus.

The objective of this study was to elucidate the kinetics and magnitudes of specific IgA antibody responses in intestines of turkey poults infected with turkey coronavirus (TCV). Turkey poults were orally inoculated with TCV at 10 days of age. Intestinal segment cultures were administered for duodenum, jejunum, and ileum and the IgA antibody responses were analyzed at 1, 2, 3, 4, 6, or 9 weeks post-infection (PI) in two different experiments. The kinetics of virus-specific IgA antibody responses in duodenum, jejunum, and ileum were similar: gradually increased from 1 week PI, reached the peak at 3 or 4 weeks PI, and declined afterward. The virus-specific IgA antibody responses in duodenum, jejunum, and ileum showed negative correlation with duration of TCV antigen in the corresponding locations of intestine with Spearman's correlation coefficient of -0.85 (p=0.034), -0.74 (p=0.096), and -0.75 (p=0.084), respectively. Moreover, the virus-specific IgA antibody responses in serum were positively correlated with that of duodenum (coefficient=0.829, p=0.042), jejunum (coefficient=0.829, p=0.042), and ileum (coefficient=0.771, p=0.072) segment cultures, suggesting that the induction of specific IgA response in serum was predictive of an IgA response in intestine. The results indicate that intestinal mucosal IgA antibodies to TCV are elicited in turkeys following infection with TCV. The local mucosal antibodies may provide protective immunity for infected turkeys to recover from TCV infection.

Animals↗
PubMed2002

Brain function and cognition in a community sample of elderly Latinos.

BACKGROUND: Previous studies using PET to measure cerebral glucose metabolism in AD have found metabolic reductions in the temporoparietal and posterior cingulate cortices in individuals with dementia and those at risk of developing it. This study was designed to extend this finding to individuals selected from a population-based cohort of Mexican Americans with a wide spectrum of cognitive ability. METHODS: A group of 93 individuals was selected from the Sacramento Area Latino Study on Aging, and subjects were categorized into four groups of increasing levels of cognitive impairment: normal, memory impaired, cognitively impaired but not demented (CIND), and demented. PET was performed with the tracer [(18)F]-fluorodeoxyglucose, and data were analyzed with both statistical parametric mapping and an atrophy-corrected volume of interest approach. RESULTS: Individuals with dementia had metabolic reductions that were most robust in the posterior cingulate cortex, whereas CIND subjects had less statistically robust reductions in the posterior cingulate cortex. Cingulate hypometabolism increased the risk of dementia and was a significant risk factor for dementia in logistic regression models that also incorporated MR measures of hippocampal volume and white matter hyperintensities. CONCLUSION: Posterior cingulate cortical hypometabolism is clearly detected in individuals with dementia who are selected from a population with lower education and a high prevalence of cerebrovascular risk factors, supporting the generalizability of this finding. These metabolic reductions occur prior to the onset of dementia but only in those persons with relatively advanced symptoms.

Aged↗
PubMed2002

Brain structure and cognition in a community sample of elderly Latinos.

BACKGROUND: Previous studies have found that hippocampal atrophy and white matter hyperintensities (WMH) on MRI are linked to cognitive impairment and dementia. The authors measured these variables in a population-based cohort of older Mexican Americans with a wide spectrum of cognitive ability, ranging from normal cognition to dementia. OBJECTIVE: To investigate whether these structural brain changes were seen in individuals prior to the development of dementia and how these changes were related to the presence of dementia. METHODS: A sample of 122 subjects was selected from the Sacramento Area Latino Study on Aging, and subjects were categorized into four groups of increasing levels of cognitive impairment: normal, memory impaired (MI), cognitively impaired but not demented (CIND), and demented. Hippocampal volume was quantified using a region of interest approach. WMH was rated on a semiquantitative scale as the percent of total volume of white matter. RESULTS: Hippocampal volume was significantly reduced in CIND and demented individuals, and WMH were significantly increased in demented subjects. MI subjects did not have any significant changes in hippocampal volume or WMH. The risk for developing dementia was significantly and comparably increased in subjects with either hippocampal atrophy or high WMH. However, the risk for dementia increased dramatically in subjects with both hippocampal atrophy and a high degree of WMH. CONCLUSION: Reductions in hippocampal volume may be present before dementia but not until cognitive impairment is relatively severe. Because there is a synergistic effect between high WMH and hippocampal atrophy, interactions between vascular and degenerative processes may be important determinants of dementia.

Aged↗
PubMed2002

Exchange nailing for aseptic nonunion of the femoral shaft.

Thirty-six nonunions of the femoral shaft were treated by closed removal of previous nails, reaming of marrow cavity as widely as possible, and reinsertion of stable intramedullary nail. Indications included femoral shaft aseptic nonunions with inserted intramedullary nail, nonunions with a radiolucent line, without segmental bony defects, and less than 1 cm shortening. They were followed up for a median of 2.9 (1-6) years. Thirty-three nonunions healed uneventfully within a median period of 4 (3-8) months. Except for three persistent nonunions, no other significant complications occurred.

Adolescent↗
PubMed2002

Purification of turkey coronavirus by Sephacryl size-exclusion chromatography.

Sephacryl S-1000 size-exclusion chromatography was used to purify turkey coronavirus (TCoV) from infected turkey embryo. TCoV was propagated in the 22-day-old turkey embryos. Intestines and intestinal contents of infected embryos were harvested and homogenized. After low speed centrifugation, the supernatant was concentrated by ultracentrifugation through a cushion of 30 or 60% sucrose solution, or by ammonium sulfate precipitation. The purification methods included sucrose gradient and Sephacryl S-1000 size-exclusion chromatography. Ultracentrifugation through a cushion of 60% sucrose solution was better than the other two methods for concentration of TCoV from intestinal homogenate. The most effective method for purifying TCoV and removing extraneous materials was size-exclusion chromatography as analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. More spike-rich particles were observed in the sample purified by chromatography than those purified by sucrose gradient as examined by electron microscopy. Differentiation of turkey anti-TCoV antiserum from normal turkey serum was better achieved by ELISA plates coated with TCoV preparation purified by size-exclusion chromatography than that purified by sucrose density gradient. The results indicated that Sephacryl S-1000 chromatography was useful for purification of TCoV.

Animals↗
PubMed2002

Left cervical aortic arch with aneurysm and obstruction: three-dimensional computed tomographic angiography and magnetic resonance angiographic appearance.

Cervical arch is a rare congenital anomaly presumed to result from persistence of the third aortic arch and regression of the normal fourth arch. Rather rare is cervical aortic arch associated with aneurysm and obstruction, with eight known cases reported. Definitive diagnosis with a noninvasive imaging modality is desirable and very important to prevent the need for disaster intervention. We present two cases of a pulsatile mass in the left supraclavicular region. Three-dimensional computed tomographic angiography and magnetic resonance angiography clearly showed a left-sided cervical aortic arch (Haughton type D) with arch aneurysm and coarctation (pseudocoarctation).

Adolescent↗
PubMed2002

Fibronectin attachment protein is necessary for efficient attachment and invasion of epithelial cells by Mycobacterium avium subsp. paratuberculosis.

Attachment and ingestion of Mycobacterium avium subsp. paratuberculosis by two epithelial cell lines were enhanced by soluble fibronectin (FN). Peptide blocking of the FN attachment protein (FAP-P) inhibited the internalization of M. avium subsp. paratuberculosis. Disruption of FAP-P expression significantly reduced attachment and ingestion of M. avium subsp. paratuberculosis by T-24 and Caco-2 cells. The results indicate that the interaction between FN and FAP-P facilitates attachment and internalization of M. avium subsp. paratuberculosis by epithelial cells.

Adhesins, Bacterial↗
PubMed2002

A sieving method for collecting the metacercariae of trematode parasites from freshwater fish.

This study describes a sieving method for the collection of metacercariae from frozen (-20 degrees C) freshwater fish. Digested fish tissue is filtered through a series of sieves; the crude filtrate is then centrifuged. Centrifugation produces a sediment from which metacercariae can be removed. Half of the metracercariae that were obtained from the fish meat that had been frozen for 10 days (-20 degrees C) were dead; the other half were alive and some larvae were moving slowly.

Animals↗
PubMed2002

Existence of gene 5 indicates close genomic relationship of Turkey coronavirus to infectious bronchitis virus.

A segment of genomic RNA extending from the 3'-end of the membrane (M) protein gene to the 5'-end of the nucleocapsid (N) protein gene of Turkey coronavirus (TCV) was amplified by reverse transcription-polymerase chain reaction (RT-PCR). The primers were derived from the corresponding sequences of Infectious bronchitis virus (IBV). The PCR products were cloned and sequenced and their nucleic acid structure and similarity to the published sequences of IBV were analyzed. Gene 5 containing two overlapping open reading frames (ORFs), 5a and 5b, was localized between M and N genes of TCV. The overall nucleotide sequences of the amplified regions from TCV isolates shared 88.4% to 91.8% similarity to the corresponding region of IBV strains. The consensus transcription-associated sequence of IBV, CTTAACAA, was highly conserved in the TCV genome with regard to nucleotide sequence and location in terms of the initiation codons of the genes 5 and N. The similarities between the predicted amino acid sequences of ORFs 5a and 5b of TCV isolates and the homologous genes of IBV strains were 85.4% to 94.0%. The results indicate the existence of gene 5 in the genome of TCV and a close relatedness of the TCV gene 5 to the IBV gene 5 in location and nucleotide sequence.

Amino Acid Sequence↗
PubMed2001

Arachidonic acid-induced H+ and Ca2+ increases in both the cytoplasm and nucleoplasm of rat cerebellar granule cells.

1. Arachidonic acid (AA) exerts multiple physiological and pathophysiological effects in the brain. By continuously measuring the intracellular pH (pH(i)) and Ca2+ levels ([Ca2+]i) in primary cultured rat cerebellar granule cells, we have found, for the first time, that 20 min treatment with 10 microM AA resulted in marked increases in Ca2+ and H+ levels in both the cytosol and nucleus. 2. A much higher concentration (40 mM) of another weak acid, propionic acid, was needed to induce a similar change in pH(i). The [Ca2+]i increase was probably caused by AA-induced activation of Ni2+-sensitive cationic channels, but did not involve NMDA channels or the Na+-Ca2+ exchanger. 3. AA-induced acidosis occurs by a different mechanism involving predominantly the passive diffusion of the un-ionized form of AA, rather than a protein carrier, as proposed by Kamp & Hamilton for fatty acids (FAs) in artificial phospholipid bilayers (the 'flip-flop' model). The following results, which are similar to those observed in lipid bilayers, support this conclusion: (1) FAs containing a -COOH group (AA, linoleic acid, alpha-linolenic acid, and docosahexaenoic acid) induced intracellular acidosis, whereas a FA with a -COOCH3 group (AA methyl ester) had little effect on pH(i), (2) a FA amine, tetradecylamine, induced intracellular alkalosis, and (3) the AA-/FA-induced pH(i) changes were reversed by bovine serum albumin. 4. Further evidence in support of a passive diffusion model, rather than a membrane protein carrier, is that: (1) there was a linear relationship between the initial rate of acid flux and the concentration of AA (2-100 microM), (2) acidosis was not inhibited by 4,4'-diisothiocyanatostilbene-2,2'-disulphonic acid, a potent inhibitor of the plasma membrane FA carrier protein, and (3) the involvement of most known H+-related membrane carriers and H+ conductance has been ruled out. 5. Since AA can be released under both physiological and pathophysiological conditions, the possible significance of the AA-evoked increases in H+ and Ca2+ in both the cytoplasm and nucleoplasm is discussed.

Acidosis↗
PubMed2001

DNA-mediated vaccination against infectious bursal disease in chickens.

The objective of the present study was to investigate the feasibility of a DNA vaccine to protect chickens against infectious bursal disease virus (IBDV) infection. A plasmid DNA carrying VP2, VP4, and VP3 genes of the standard challenge (STC) strain of IBDV was constructed and designated as pCR3.1-VP243-STC. One-day-old chickens were intramuscularly injected with the plasmid pCR3.1-VP243-STC once (group D1), twice (group D2), or three times (group D3) at weekly intervals. Chickens at 3 weeks old were orally inoculated with IBDV strain STC and observed for 10 days after challenge. Immunization twice (group D2) or three times (group D3) with the plasmid pCR3.1-VP243-STC conferred protection for 50-100 or 80-100% of chickens, respectively, as evidenced by the absence of clinical signs, mortality, and bursal atrophy. Although chickens vaccinated once (group D1) with the plasmid pCR3.1-VP243-STC did not have clinical signs, they exhibited varying degree of bursal atrophy after challenge. Enzyme-linked immunosorbent assay (ELISA) antibody titers in chickens protected by the plasmid pCR3.1-VP243-STC were significantly lower (P<0.05) than those not protected 10 days after challenge. IBDV antigen was not detected in the bursae of chickens that were protected by receiving the plasmid pCR3.1-VP243-STC twice or three times. The results indicate that the constructed plasmid pCR3.1-VP243-STC as a DNA vaccine provided efficacious protection for chickens against IBDV infection.

Animals↗