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H J Wang

Publications and source records attributed to H J Wang.

At least 19 recordsLinked to original sources
PubMed1999

The primary immunity determinant in modulating the lysogenic immunity of the filamentous bacteriophage cf.

Bacteriophage cf is the first single-stranded DNA phage that has been shown to set up a stable lysogenic state with its genome integrated into the host chromosome. From the isolation and characterization of a virulent mutant, cf-tv2, we report the first investigation into the mechanisms of the immunity established by the filamentous bacteriophage. The mutation in cf-tv2 enables the phage to produce plaques on lawns of cf lysogenic cells. The mutation was defined as a 49-nucleotide deletion located in a 0.59 kb NcoI/KpnI fragment of cf replicative form DNA. Two messages, cM1 and cM2, transcribed from the immunity region of wild-type cf but in opposite directions, were detected. In cf-tv2, the 49-nucleotide deletion abolishes cM2 transcription. The primer extension assay suggests a possible RNA-RNA interaction directed by base-pairing of the cM1 and cM2 RNAs. A frameshift mutation of the open reading frame ORF 165, encoded by cM2, resulted in a 10(5) plating efficiency on the cf lysogen. These observations suggest that both RNA-RNA interaction and repressor protein inhibition are involved in the mechanism of cf immunity. A model is proposed for the regulation of cf immunity.

Amino Acid Sequence↗
PubMed1999

Transcription of the genome of the filamentous bacteriophage cf from both plus and minus DNA strands.

The filamentous bacteriophage cf infects the bacterium Xanthomonas campestris pv. citri. Northern blot analysis with probes derived from various restriction fragments of cf replicative form (RF) DNA has revealed the presence of five major phage-specific transcripts in infected cells. Four of these transcripts were shown to be derived from the region of the cf genome extending from gene II to gene VIII and are consistent with the cascade model of transcription proposed for Ff coliphages. These transcripts overlap with each other and terminate upstream of an efficient Rho-independent transcription terminator. Unlike the well-characterized Ff phages, in which only the minus strand of viral DNA serves as a transcription template, both strands of the RF DNA of phage cf appeared to be transcribed. Thus one of the five major cf transcripts was shown to be derived from a region of the viral minus strand that contains an open reading frame encoding a putative polypeptide of 165 amino acids. Primer extension analysis mapped the transcriptional initiation site of this RNA to a cytosine residue at position 870. A partial transcription map of phage cf revealed two independent regions of transcriptional activity. The region with the highest activity coincides with that encoding the polypeptides required in the largest amounts during the cf infection cycle.

5' Untranslated Regions↗
PubMed1999

Demonstration of thyrotropin receptor mRNA in orbital fat and eye muscle tissues from patients with Graves' ophthalmopathy by in situ hybridization.

There is a controversy regarding whether there are thyrotropin (TSH) receptors in orbital fat and eye muscle tissues that may play a role in the pathogenesis of Graves' ophthalmopathy. To elucidate whether there are TSH receptors in orbital fat and eye muscle tissues in patients with Graves' ophthalmopathy, we applied the method of in situ hybridization in orbital fat and eye muscle tissues obtained during the operation for patients with Graves' ophthalmopathy, to directly detect TSH receptor mRNA. To identify whether the cells with positive TSH receptor mRNA are fibroblasts, we also did vimentin immunoreactivity study. To further prove the transcript does have a full length of TSH receptor, the samples of total RNA preparations, extracted from orbital fat and eye muscle tissues, were used as a template for reverse transcriptase polymerase chain reaction (RT-PCR) using three primer sets to generate cDNA fragments and cloned for sequencing. The results showed that the expression of TSH receptor mRNA was demonstrated in adipocytes and fibroblasts of orbital fat, and perimysial fibroblasts within eye muscle tissues by in situ hybridization and vimentin immunoreactivity study. Also, by using the RT-PCR, cloning and sequencing, we further proved that the transcript does have a full length of TSH receptor. The present study suggested that there are TSH receptors expressed in orbital fat and eye muscle tissues.

Adipocytes↗
PubMed1999

Disease-inducible transgene expression from a recombinant adeno-associated virus vector in a rat arthritis model.

Rheumatoid arthritis (RA) is a systemic autoimmune disease affecting 1% of the world's population, with significant morbidity and mortality. In this study, we investigated a recombinant adeno-associated virus (rAAV) vector for its potential application in RA gene therapy. rAAV encoding Escherichia coli beta-galactosidase was injected into rat joints which had already been induced into acute arthritis after local lipopolysaccharide (LPS) administration, and the efficiency of in vivo transduction was evaluated. We observed a striking correlation between vector transgene expression and disease severity in arthritic joints. The inflammatory reaction peaked at 3 to 7 days after LPS treatment, and, at the same time, 95% of the synoviocytes had high-level transgene expression. Gene expression diminished to the basal level (5%) when the inflammation subsided at 30 days after LPS treatment. More importantly, the diminished transgene expression could be efficiently reactivated by a repeated insult. The transgene expression in normal joints transduced with rAAV remained low for a long period of time (30 days) but could still be induced to high levels (95%) at 3 to 7 days after LPS treatment. This is the first demonstration of disease state-regulated transgene expression. These findings strongly support the feasibility of therapeutic as well as preventative gene transfer approaches for RA with rAAV vectors containing therapeutic genes, which are expected to respond primarily to the disease state of the target tissue.

Animals↗
PubMed1999

Preparation and properties of immobilized pig kidney aminoacylase and optical resolution of N-acyl-DL-alanine.

Aminoacylase (EC 3.5.1.14) was immobilized into DEAE-Sephadex A-25 by ion-exchange absorption for optical resolution of N-acyl-DL-alanine. The effects of pH, temperature, and Co2+ concentration on the activity of free and immobilized enzymes were investigated along with the operational and the thermal stability of the immobilized enzyme. The immobilized enzyme retained high catalytic activity. The optimum pH and temperature for the hydrolysis of N-acyl-L-alanine in the DL-isomer mixture were 8.0 and 65 degrees C, respectively. Co2+ was an activator for the immobilized enzyme in a similar role as for the free enzyme. No significant loss of activity was observed for at least 300 h of continuous operation. The yield of L-alanine was about 70% of the theoretical yield. The immobilized aminoacylase column decayed over a very long period of operation, but could be completely reactivated by regeneration.

Alanine↗
PubMed1999

Influence of polymorphism at p53, CYP1A1 and GSTM1 loci on p53 mutation and association of p53 mutation with prognosis in lung cancer.

BACKGROUND: We previously found that the majority (9/11) of p53 tumor suppressor gene mutations in 60 lung cancer patients in Taiwan were small intragenic deletions and nonsense mutations. To gain insights into the possible etiologic factors involved in these mutations and the prognostic significance of p53 gene mutations in lung cancer in Taiwan, we investigated the influence of polymorphism at p53, cytochrome p450 1A1 (CYP1A1) and glutathione S-transferase M1 (GSTM1) loci on p53 gene mutation, and the association of p53 gene mutation with prognosis in these lung cancer patients. METHODS: The polymorphism of these genes was determined by polymerase chain reaction followed by restriction enzyme digestion. The Pearson chi 2 test was used to compare allelic distributions between lung cancer patients and controls. The log-rank test was used to assess the significance of the survival differences between patients with and without p53 mutations. RESULTS: There was no significant difference with respect to the genotype distribution of p53, CYP1A1 and GSTM1 polymorphisms between patients with and without p53 mutations, although a tendency toward increasing frequency of the wild-type homozygote genotype of p53 polymorphism was noted in lung cancer patients containing p53 mutations. We further analyzed the association of p53 mutation with prognoses in lung cancer patients for whom postoperative survival data were available. The estimated median survival times for patients with and without p53 mutation were 25 and 28 months, respectively. There was no significant correlation between p53 mutation and survival. CONCLUSIONS: Our data suggest that p53 gene mutation may not be associated with polymorphisms of p53, CYP1A1 and GSTM1 genes, and it may have no significant effect on the prognosis of lung cancer patients in Taiwan.

Chromosome Mapping↗
PubMed1998

Characterization of the C-terminal domain of Helicobacter pylori vacuolating toxin and its relationship with extracellular toxin production.

Helicobacter pylori vacuolating cytotoxin (VacA) induces gastric epithelial necrosis. Its C-terminal domain is hypothesized to be responsible for extracellular translocation of the mature cytotoxin. In this study, genetic-structural properties of VacA C-terminal domain and the level of cytotoxin secretion were investigated. Sau3AI-HaeIII restriction fragment length polymorphism (RFLP) analysis of the 1.1-kb PCR-amplified vacA fragment revealed 14 distinct combined patterns among 87 clinical isolates. Of the 4 popular groups (A-a, A-b, A-f, and B-a), A-a strains produced a higher level of the VacA protein than A-b strains and than A-f strains (P < 0.05). Sequence analysis and secondary structure prediction supported a beta-barrel structure that might act as a selective export channel like Iga beta-core of IgA proteases. Sequence differences in the predicted beta-barrel were present among strains of different RFLPs.

Amino Acid Sequence↗
PubMed1998

Complete cytoreductive surgery is feasible and maximizes survival in patients with advanced epithelial ovarian cancer: a prospective study.

OBJECTIVE: Despite correlation between the completeness of surgical cytoreduction and survival for patients with advanced ovarian cancer, relatively few undergo complete cytoreduction. This study was initiated to prospectively determine the ability to surgically eliminate all visible disease in patients with stage IIIC and IV epithelial ovarian cancer and the associated impact on survival. METHODS: Between 1990 and 1996, 163 consecutive patients underwent primary cytoreduction. The goal was the excision or ablation of all visible disease prior to initiation of systemic platinum-based combination chemotherapy. A multivariate analysis determined which clinical and pathologic variables influenced the probability of achieving complete cytoreduction (logistic regression) and survival (Cox proportional hazards model). RESULTS: One hundred thirty-nine patients (85.3%) underwent removal of all visible tumor, 22 (13.5%) had cytoreduction to </=1 cm residual disease, and 2 (1.2%) had unresected bulky disease. The median and estimated 5-year survival for the entire cohort was 54 months and 48%, respectively. The probability of achieving complete cytoreduction was influenced independently by the preoperative Gynecologic Oncology Group performance status (0-1 vs 2-3, P = 0.04), the number of mesenteric and intestinal serosal implants (</=75 vs >75 implants, P = 0.005), and stage (IIIC vs IV, P = 0.006). The probability of survival was independently influenced by age (</=61 vs >61 years, P = 0.003), volume of ascites (</=1 vs >1 liter, P = 0.01), stage (IIIC vs IV, P = 0.04), histology (clear cell and mucinous vs all other, P = 0.03), and the completeness of cytoreductive operation (complete vs incomplete cytoreduction, P = 0.02). CONCLUSIONS: Complete cytoreduction is possible for the majority of patients and improves survival, even compared to operations with minimal (</=1 cm) residual disease. Unless their medical condition prohibits anesthesia and surgery, patients with advanced epithelial ovarian cancer should undergo primary cytoreductive surgery with the intention of complete tumor removal.

Carcinoma↗
PubMed1998

Skin injury in the operating room.

Skin injury occurring in the operating room may occur as a result of electrical current, thermal injury, chemical irritation and mechanical stress. Between 1 December 1996 and 28 February 1997, 19 cases of skin injury from a total of 3657 operations were noted in our hospital. These injuries tend to be ignored because of their early spontaneous healing. We suggest that medical staff should pay more attention to this complication and prevent it from occurring.

Adult↗
PubMed1998

Alkaline-induced unfolding and salt-induced folding of pig heart lactate dehydrogenase under high pH conditions.

The alkaline-induced unfolding and the salt-induced folding of pig heart lactate dehydrogenase under high pH conditions have been followed by fluorescence emission spectra and circular dichroism spectra. The results for alkaline-induced denaturation of lactate dehydrogenase show that at low ionic strength, increasing the pH value increased the extent of unfolding of the enzyme to the maximum ultimate unfolded conformation at about pH 13.0. At pH 12.5, although the enzyme was completely inactivated, most of the ordered structure was retained. Even at pH 13.5, the apparently fully unfolded enzyme still retained some ordered secondary structure. Kinetic analysis showed that at high pH, the inactivation rate constants of the enzyme are an order of magnitude faster than the unfolding rate constants at least. The above results are in accord with the suggestion by Tsou (Trends Biochem Sci 1986;11:427-429 and Science 1993;262:380-381) that the active site is usually more flexible than the enzyme molecule. At pH 13.0, adding salt to the solution caused the relatively unfolded state of the denatured enzyme to change into a compact conformational state by hydrophobic collapsing. The folded state induced by the salt bound ANS strongly, indicating the existence of an increased hydrophobic surface. The above results suggest that the salt-induced folded state at high pH may be the folded intermediate which exists in the general protein folding and that the large residual ordered secondary structure might become folded during the salt-induced folding.

Anilino Naphthalenesulfonates↗
PubMed1998

The comparison of early fluid therapy in extensive flame burns between inhalation and noninhalation injuries.

Over the last half century, advances in treatment have changed the principal cause of death in burn patients from burn shock and wound sepsis to pulmonary sepsis, of which inhalation injury has always played a key role in morbidity and mortality. Even though Navar et al., Am. J. Surg. 1985;150:716-720 have noted that patients with inhalation injury had a mean fluid requirement of 5.8 ml/kg/% burn to achieve resuscitation from early burn shock, while patients without inhalation injury required only a mean fluid of 4.0 ml/kg/% burn, to achieve successful resuscitation in inhalation injured patients with minimum but adequate fluid has always been a challenge. To further define the difference of early fluid therapy between inhalation and noninhalation in extensively burned patients, a retrospective analysis was carried out in the Tri-Service General Hospital. Sixty-two flame burned patients (aged from 16 to 81 years-old with a mean age of 33.2+/-15.1 years: with burn size ranging from 30% to 98% TBSA with a mean burn size of 60.5+/-22.7%; 26 with inhalation injury; noninhalation 36) were reviewed during a 5-year period. The Parkland formula is the initial choice of fluid regimen with 4 ml/kg/% burn and the amount of replacement is monitored by urine output and is titrated to maintain urine output between 0.5 and 1.0 ml/kg/h. The mean amounts of fluid requirements of both inhalation and noninhalation burned patients were 3.1 +/- 1.0 and 2.3+/-0.8 ml/kg/% burn respectively (p < 0.05). Our study showed less fluid requirement for both inhalation and noninhalation injured patients in comparison with the Navar study and Parkland predictions in the first 24 h postburn. Furthermore, the inhalation injured patients definitely required volumes of fluid in excess of those required in noninhalation injured cases.

Adolescent↗
PubMed1998

Effect of local injection of botulinum toxin on sphincter of Oddi cyclic motility in dogs.

To study effects of intrasphincteric injections of botulinum toxin on the sphincter of Oddi cyclic motility and responses to motilin and cholecystokinin, four conscious dogs with duodenal cannula underwent manometry of the common bile duct, sphincter of Oddi, and duodenum. After baseline recording, each dog had intrasphincteric injections of saline or botulinum toxin. The injections of saline had no effect, whereas botulinum toxin significantly reduced mean basal pressure, amplitude, and motility index of the sphincter of Oddi. These effects took place in four to seven days and reached a maximum in seven to 10 days. The basal pressure returned to the baseline level in 28 weeks, but the amplitude and motility index remained low. The pressure parameters of motilin-induced premature phase III-like activity also decreased, but action of cholecystokinin was not affected. These results indicate that the botulinum toxin injections reduce sphincter of Oddi phasic contractile activity for a prolonged period of time.

Animals↗
PubMed1998

Endoscopically-assisted adipofascial flap harvest for soft tissue defects of the lower leg.

Five cases of soft tissue defect of the lower leg were reconstructed successfully with the distally based medial adipofascial flap which was harvested with endoscopically-assisted surgery. The size of these flaps ranged from 4.0 x 7.0 cm to 5.0 x 15.0 cm in size. All the flaps had good perfusion and uneventful course postoperatively. The donor site skin was intact except for an additional access-scar 2.5 cm in length. The donor site morbidity of the adipofascial flap was further minimised in this series.

Accidents, Traffic↗
PubMed1998

The distally based lateral adipofascial flap.

The distally based lateral adipofascial flap can be based either on the lowermost perforator or the anterior perforating branch of the peroneal artery avoiding sacrifice of the main peroneal artery. It has been used successfully to resurface soft tissue defects either on the lateral or medial aspect of the lower third of the leg in 13 cases. The size of these flaps varied from 2.0 cm x 5.0 cm to 4.5 cm x 15.0 cm in size. These cases had minimal donor site morbidity and had positive aesthetic results. The advantages were: 1. Choice of either the lowermost perforator or the anterior perforating branch giving a wide arc of rotation; 2. Preservation of the superficial peroneal nerve; 3. Primary closure of the donor site.

Adult↗
PubMed1998

Vacuolating toxin gene polymorphism among Helicobacter pylori clinical isolates and its association with m1, m2, or chimeric vacA middle types.

BACKGROUND: Helicobacter pylori vacuolating cytotoxin encoded by vacA plays an essential role in H. pylori-related pathogenesis. Specific vacA alleles are believed to be associated with increased virulence. Association among vacA polymorphism, vacA middle genotypes, and various H. pylori-related diseases was thus investigated. METHODS: Eighty-nine isolates from patients with various gastrointestinal diseases were examined for restriction fragment length polymorphism (RFLP) of the 2.0-kb polymerase chain reaction-amplified vacA middle region. Further genetic heterogeneity was assessed with ureA-ureB RFLP. RESULTS: Twenty-eight distinct vacA RFLPs were seen among 89 isolates. Each pattern was associated with one specific vacA middle genotype. The association of specific RFLPs with certain clinical manifestations was noted among six common groups. Further RFLP analysis of the 2.4-kb ureA-ureB segment from isolates in four popular vacA RFLPs showed high genetic variation. CONCLUSIONS: The vacA genetic polymorphism may be associated with different gastrointestinal diseases.

Bacterial Proteins↗
PubMed1998

Vacuolating toxin production in clinical isolates of Helicobacter pylori with different vacA genotypes.

A vacuolating cytotoxin encoded by vacA in Helicobacter pylori is known as a potential virulent determinant. The relationship between different vacA alleles, vacuolating ability, and H. pylori-related diseases was investigated. Genetic analysis of 119 isolates from Taiwanese patients revealed that 104 strains were s1a/m2, 13 strains were characterized as the s1a/m1T type, which was more homologous to the s1a/m1 strains, and 2 were characterized as the s1a/m1Tm2 chimeric type. Production of high-grade cytotoxin among 11 strains with s1a/m1T was higher (72.7%) than among 66 strains with s1a/m2 (21.2%) (P < .01). Peptic ulcer occurred in 76.9% of 13 patients with s1a/m1T strains compared with 46.2% of 104 patients with s1a/m2 strains (P < .05). These results suggest that s1a/m1T strains are associated with increased cytotoxic activity and higher ulcer prevalence than are s1a/m2 strains.

Amino Acid Sequence↗
PubMed1998

On the influence of sample size on the prognostic accuracy and reproducibility of renal transplant biopsy.

INTRODUCTION: The minimal specimen size necessary for accurate interpretation of a renal biopsy has not been identified. We attempted such a determination by three different analyses of a collection of biopsies performed in renal transplants. METHODS: First, we studied the influence of three lesions (glomerulosclerosis, arteriolar hyalinosis, interstitial fibrosis/tubular atrophy) in 199 baseline biopsies, obtained at time of transplantation, on transplant outcome. Secondly, we compared the results from the three lesions in baseline biopsy with those from 114 subsequent core biopsies in the same patients. Thirdly, we compared the two baseline biopsies obtained in 118 paired kidneys in cadaver transplantation where both kidneys were used. RESULTS: For statistically significant prediction of outcome from glomerulosclerosis, we found that a specimen containing at least 25 glomeruli was needed in the baseline biopsy. Arteriolar hyalinosis predicted outcome independent of sample size, but became less important than percentage glomerulosclerosis in predicting outcome if only samples containing more than 25 glomeruli were considered. Interstitial fibrosis/tubular atrophy did not predict the outcome of a kidney, independent of sample size. When comparing baseline with subsequent core biopsies, or with paired baseline biopsies, at least 14 glomeruli were necessary to allow even moderate reproducibility of glomerulosclerosis (Cohen's kappa > 0.25) and to allow statistical significance (P < 0.05). The reproducibility of arteriolar hyalinosis was not dependent on sample size but was reproducible in 80% of paired baseline biopsies, and in 67% of the comparison of the baseline with core biopsy. Both precision and significance was lost if sample numbers were reduced by including only larger samples. There was no reproducibility in any study of interstitial fibrosis/tubular atrophy when comparing either baseline with subsequent biopsy, or paired baseline biopsies. SUMMARY: Much larger biopsy samples are necessary than has generally been assumed in order for glomerulosclerosis rates to be reproducible or predictive of outcome. Arteriolar hyalinosis is prognostically important and shows good reproducibility independent of sample size. Interstitial fibrosis/tubular atrophy appear useless as predictors, being of no prognostic importance and lacking reproducibility. Our finding clarifies some of the discrepancies found by different investigators regarding the importance of renal biopsy in predicting prognosis. Preliminary, our data indicate that samples containing fewer than 25 glomeruli are unreliable in determining outcome based on glomerulosclerosis. The importance of our findings which are based only on chronic lesions, with respect to acute changes, is unknown.

Adolescent↗