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Biomedical subjects

L Y Chang

Publications and source records attributed to L Y Chang.

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

Expression of capsid [correction of caspid] protein VP1 for use as antigen for the diagnosis of enterovirus 71 infection.

To produce enterovirus 71 antigen for diagnostic purposes, the gene encoding the entire capsid protein VP1 was amplified by reverse transcription-polymerase chain reaction (RT-PCR), cloned and expressed in Escherichia coli as a poly-histidine fusion protein. Western blotting experiments with sera from patients with enterovirus 71 infection indicated that immunoglobulin G (IgG) and IgM antibodies bound to a single polypeptide VP1. According to these results, IgM anti-VP1 appeared in sera of patients with a symptomatic enterovirus 71 acute infection, whereas IgG anti-VP1 was present in sera of past infection. This finding suggests that detecting IgG and IgM immune responses against linear epitopes of recombinant VP1 is an effective means of determining the different phases of enterovirus 71 infection. In addition, sera containing coxsackie virus 16 (CA16) antibodies did not cross-react with the recombinant VP1 of enterovirus 71, despite the homology between VP1 proteins of both viruses. Comparison with reference PCR and neutralization assays showed these antibody tests to be appropriate for the serodiagnosis of enterovirus 71 infection.

Antibodies, Viral↗
PubMed2000

Genetic analysis of enterovirus 71 isolated from fatal and non-fatal cases of hand, foot and mouth disease during an epidemic in Taiwan, 1998.

A large scale outbreak of hand-foot-and-mouth disease (HFMD) occurred in Taiwan in 1998, in which more than 80 children died of shock syndrome with pulmonary edema/hemorrhage. Enterovirus 71 was implicated as the cause of this outbreak. In order to understand the virological basis responsible for mortality on this scale, nucleotide sequences of VP1 that is important for serotypic specificity, and the 5'-non-coding region (5'-NCR) that is important for replication efficiency, were analyzed comparatively. Phylogenetic analysis of both VP1 and 5'-NCR of nine EV71 isolates derived from specimens of fatal patients and seven isolates derived from uncomplicated HFMD patients showed that all but one isolate fell into genotype B. The one distinct isolate from a case of uncomplicated HFMD belonged to genotype C that was clustered along with one isolate from Taiwan in 1986. Complete sequence analysis of two selected isolates, one from the spinal cord of a fatal case and one from the vesicle fluid of a patient with mild HFMD, confirmed a high degree (97-100%) of identity in nucleotide sequence throughout the entire genome, except focal regions of 3C and 3'-NCR where the nucleotide homology was 90-91%. The identity of the deduced amino acid sequence in the 3C region that encodes viral proteinase dropped further to 86%, a result of missense mutations at the first nucleotide position of many codons.

5' Untranslated Regions↗
PubMed2000

Acute encephalomyelitis during an outbreak of enterovirus type 71 infection in Taiwan: report of an autopsy case with pathologic, immunofluorescence, and molecular studies.

We report a fatal case of enterovirus type 71 (EV 71) infection in an 8-year-old girl during a summer outbreak of hand, foot, and mouth disease in 1998 in Taiwan. The clinical course was rapidly progressive, with manifestations of hand, foot, and mouth disease, aseptic meningitis, encephalomyelitis, and pulmonary edema. The patient died 24 hours after admission. Postmortem study revealed extensive inflammation in the meninges and central nervous system and marked pulmonary edema with focal hemorrhage. Brain stem and spinal cord were most severely involved. The inflammatory infiltrates consisted largely of neutrophils involving primarily the gray matter with perivascular lymphocytic cuffing, and neuronophagia. The lungs and heart showed no evidence of inflammation. EV 71 was isolated from the fresh brain tissues and identified by immunofluorescence method with type-specific EV 71 monoclonal antibody. It was also confirmed by neutralization test and reverse-transcriptase polymerase chain reaction with sequence analysis. The present case was the first example in which EV 71 was demonstrated to be the causative agent of fatal encephalomyelitis during its epidemic in Taiwan.

Antigens, Viral↗
PubMed2000

Factors associated with intestinal perforation in children's non-typhi Salmonella toxic megacolon.

BACKGROUND: To evaluate the risk factors for intestinal perforation in children with toxic megacolon caused by non-typhi Salmonella infection. METHODS: During an 11-year period we reviewed the records of children treated for non-typhi Salmonella infection. All of the subjects had positive stool culture for non-typhi Salmonella and were treated with intravenous ceftriaxone during hospitalization. Clinical data reviewed included demographic features, clinical manifestations, laboratory findings, radiologic findings, microbiology, therapeutic effect of hydration and rectal tube placement and the operative findings. Patients with toxic megacolon were defined as those having toxic appearance, diarrhea, high fever (>39 degrees C) and marked colon dilatation with maximal diameter > 1.5 times the width of the vertebra body of the first lumbar spine (L1-VB). To define the risk factors for patients with toxic megacolon complicated by intestinal perforation, patients were divided into two groups for analysis: P group, those complicated with intestinal perforation; and NP group, those without intestinal perforation. Differences in age, sex, severity of diarrhea, duration of fever, hemogram and its differential, culture, stool analysis, serum C-reactive protein (CRP), electrolytes, maximal colon diameter, medical therapy and timing of rectal tube insertion between the two groups were analyzed. Statistical analyses were conducted with chi square tests and multiple logistic regression. RESULTS: A total of 75 patients (P group, 27 patients; NP group, 48 patients) ages 4 months to 6 years were evaluated. With chi square analysis 7 variables were found to be significantly associated with intestinal perforation: age >1 year; fever >5 days; ratio of immature to total neutrophils >20%; serum CRP >200 mg/l; colon diameter >2.5 times the width of L1-VB; inadequate early hydration; and delay in rectal tube insertion. With multivariate analysis age >1 year, serum CRP >200 mg/l and colon diameter >2.5 times of width of L1-VB, inadequate early hydration and delay in rectal tube insertion were the most significant factors associated with intestinal perforation. CONCLUSION: Identification of patients with toxic megacolon associated with non-typhi Salmonella infection at risk for further intestinal perforation is possible. Early effective fluid resuscitation and rectal tube insertion may be helpful to prevent the occurrence of intestinal perforation.

Child↗
PubMed1999

Clinical features and risk factors of pulmonary oedema after enterovirus-71-related hand, foot, and mouth disease.

BACKGROUND: In Taiwan, from April to July, 1998, an epidemic of hand, foot, and mouth disease associated with enterovirus 71 (EV71) occurred with fatal complications. We did a clinical study of EV71-related diseases in Taiwan. METHODS: We studied 154 children with virus-culture confirmed EV71 infection. Children were divided into three groups: 11 patients with pulmonary oedema; 38 patients with central nervous system (CNS) involvement and no pulmonary oedema; and 105 children without complications. We compared the clinical features, laboratory findings, risk factors, and outcome among these three groups. FINDINGS: Nine children with pulmonary oedema had hand, foot, and mouth disease, one had herpangina, and one had febrile illness with eight children with limb weakness and one with limb hypesthesia. All children had had sudden onset of tachycardia, tachypnoea, and cyanosis 1-3 days after onset of the disease. Nine of 11 children died within 12 h of intubation; one child was braindead within 15 h and died 17 days after intubation; one child was in deep coma and died 3 months later. In children with CNS complication and no pulmonary oedema, one child died of pneumonia after 4 months of ventilator support and four children had sequelae. All 105 children without complications recovered. There was a significant association between CNS involvement and pulmonary oedema (odds ratio 12.4 [95% CI 2.6-60.1], p=0.001). Risk factors for pulmonary oedema after CNS involvement were hyperglycaemia, leucocytosis, and limb weakness. Hyperglycaemia was the most significant prognostic factor for pulmonary oedema (odds ratio 21.5 [3-159], p=0.003). INTERPRETATION: EV71 can cause hand, foot, and mouth disease, CNS involvement with severe sequelae, and fatal pulmonary oedema. Hyperglycaemia is the most important prognostic factor.

Adolescent↗
PubMed1999

A mechanism of paraquat toxicity involving nitric oxide synthase.

Paraquat (PQ) is a well described pneumotoxicant that produces toxicity by redox cycling with cellular diaphorases, thereby elevating intracellular levels of superoxide (O-(2)). NO synthase (NOS) has been shown to participate in PQ-induced lung injury. Current theory holds that NO reacts with O-(2) generated by PQ to produce the toxin peroxynitrite. We asked whether NOS might alternatively function as a PQ diaphorase and reexamined the question of whether NO/O-(2) reactions were toxic or protective. Here, we show that: (i) neuronal NOS has PQ diaphorase activity that inversely correlates with NO formation; (ii) PQ-induced endothelial cell toxicity is attenuated by inhibitors of NOS that prevent NADPH oxidation, but is not attenuated by those that do not; (iii) PQ inhibits endothelium-derived, but not NO-induced, relaxations of aortic rings; and (iv) PQ-induced cytotoxicity is potentiated in cytokine-activated macrophages in a manner that correlates with its ability to block NO formation. These data indicate that NOS is a PQ diaphorase and that toxicity of such redox-active compounds involves a loss of NO-related activity.

Animals↗
PubMed1999

Analysis of injury severity and vehicle occupancy in truck- and non-truck-involved accidents.

The impact that large trucks have on accident severity has long been a concern in the accident analysis literature. One important measure of accident severity is the most severely injured occupant in the vehicle. Such data are routinely collected in state accident data files in the U.S. Among the many risk factors that determine the most severe level of injury sustained by vehicle occupants, the number of occupants in the vehicle is an important factor. These effects can be significant because vehicles with higher occupancies have an increased likelihood of having someone seriously injured. This paper studies the occupancy/injury severity relationship using Washington State accident data. The effects of large trucks, which are shown to have a significant impact on the most severely injured vehicle occupant, are accounted for by separately estimating nested logit models for truck-involved accidents and for non-truck-involved accidents. The estimation results uncover important relationships between various risk factors and occupant injury. In addition, by comparing the accident characteristics between truck-involved accidents and non-truck-involved accidents, the risk factors unique to large trucks are identified along with the relative importance of such factors. The findings of this study demonstrate that nested logit modeling, which is able to take into account vehicle occupancy effects and identify a broad range of factors that influence occupant injury, is a promising methodological approach.

Accidents, Traffic↗
PubMed1999

Symptomatic tracheal stenosis in burns.

Tracheal stenosis in burns is rare and usually results from prolonged intubation or tracheostomy. Inhalation injury itself has the potential risk of tracheal stenosis. We reviewed the records of 1878 burn patients during 1987 to 1995 and found seven with tracheal stenosis (0.37%) after an average of 4.4 years follow up. There were 4 males and 3 females with an average age of 27.3 years. The tracheal stenosis developed 1-22 months after burn (average 7 months). Five patients had their inhalation injury confirmed by bronchoscopic examination. The incidence of tracheal stenosis among inhalation injury patients was 5.49% (5/92). Six patients needed intubation in the initial stage either for respiratory distress or prophylaxis, with an average duration of 195.2 h. In addition to prolonged intubation, the presence of inhalation injury, repeated intubations and severe neck scar contractures are also contributors to tracheal stenosis in burns. We favor T-tube insertion as the first treatment choice; permanent tracheostomy was unsatisfactory in our study.

Adolescent↗
PubMed1999

Specific in vitro phosphorylation of plant eIF2alpha by eukaryotic eIF2alpha kinases.

Phosphorylation of the alpha subunit of eukaryotic initiation factor 2 (eIF2alpha) is known to be an important translational control mechanism in all eukaryotes with the major exception of plants. Regulation of mammalian and yeast eIF2alpha activity is directly governed by specific phosphorylation on Ser-51. We now demonstrate that recombinant wheat wild-type (51S) but not mutant 51-Ala (51A) protein is phosphorylated by human PKR and yeast GCN2, which are defined eIF2alpha kinases. Further, only wheat wild-type eIF2alpha is a substrate for plant-encoded, double-stranded RNA-dependent kinase (pPKR) activity. Plant PKR and GCN2 phosphorylate recombinant yeast eIF2alpha 51S but not the 51A mutant demonstrating that pPKR has recognition site capability similar to established eIF2alpha kinases. A truncated version of wild-type wheat eIF2alpha containing 51S but not the KGYID motif is not phosphorylated by either hPKR or pPKR suggesting that this putative eIF2alpha kinase docking domain is essential for phosphorylation. Taken together, these results demonstrate the homology among eukaryotic eIF2alpha species and eIF2alpha kinases and support the presence of a plant eIF2alpha phosphorylation pathway.

Eukaryotic Cells↗
PubMed1999

Accurate assessment of tissue expansion in the lower face and anterior neck by a simple measurement technique.

A simple, precise method of clinical estimation for the accurate assessment of tissue expansion in the lower face and anterior neck is described using fixed anatomical reference points. The method makes it possible to select the most suitable size of tissue expander and to decide the optimal timing of operation. By recording the baseline data before expansion and repeating measurements as expansion proceeds, the discrepancy of the expectation between the surgeon and patient concerning the postoperative result can also be minimised.

Cicatrix↗
PubMed1999

Comparison of enterovirus 71 and coxsackie-virus A16 clinical illnesses during the Taiwan enterovirus epidemic, 1998.

OBJECTIVES: To compare enterovirus 71 (EV 71) with coxsackievirus A16 (Cox A16) clinical illness in patients at Chang Gung Children's Hospital during Taiwan's enterovirus epidemic of 1998. METHODS: With the use of the immunofluorescence assay and neutralization test, 177 cases of EV 71 and 64 cases of Cox A16 illness were confirmed from April to September, 1998. The clinical signs and symptoms, complications and case fatality rates were compared. RESULTS: Three-fourths of the cases were younger than 3 years of age, and the ratio of males to females was 1.3 in the EV 71 group and 1.2 in the Cox A16 group. In the EV 71 group 120 (68%) cases were uncomplicated, including 94 cases of hand, foot and mouth disease and 15 cases of herpangina, and 57 (32%) cases had complications, including 13 (7.3%) cases of aseptic meningitis, 18 (10%) cases of encephalitis, 4 (2.3%) cases of polio-like syndrome, 8 (4.5%) cases of encephalomyelitis and 12 (6.8%) cases of fatal pulmonary edema. Fourteen (7.9%) patients died, including 12 cases of pulmonary edema and 2 cases of encephalitis; seven (4%) patients had sequelae. By contrast, 60 (94%) of the 64 cases of Cox A16 infection were uncomplicated and only 4 (6.3%) cases were complicated by aseptic meningitis; no fatalities or sequelae were observed. By multivariate analysis vomiting (P = 0.01) and fever higher than 39 degrees C plus lasting longer than 3 days (P = 0.02) were significantly more frequent in the EV 71 group. CONCLUSION: EV 71 illness is more severe with significantly greater frequency of serious complications and fatality than is illness caused by Cox A16.

Adolescent↗
PubMed1999

Telomerase activity and in situ telomerase RNA expression in oral carcinogenesis.

To investigate the role of telomerase in oral carcinogenesis, we assayed telomerase activity in various oral tissues by a modified telomeric repeat amplification protocol (TRAP) analysis. Also, using digoxigenin-labeled probes, we measured the in situ expression of human telomerase RNA component (hTR) in paired oral squamous cell carcinomas (OSCC) and adjacent non-cancerous matched tissue (NCMT). We detected telomerase activity in three OSCC cell lines, but not in primary oral keratinocytes. In patient samples, most OSCC (36/42, 86%) and oral premalignant lesions (8/12, 67%) possessed telomerase activity. In addition, 6 of 27 (22%) NCMT contained weak telomerase activity. In situ hybridization showed that hTR was expressed in almost all OSCC (23/27, 85%) as well as in the majority of NCMT (20/25, 80%). In most cases, accumulation of hTR was observed both in the nucleus and cytoplasm of epithelial cells. A correlation between hTR expression and more advanced tumor grade was observed. The appearance of telomerase activation and hTR expression during oral carcinogenesis was different. This study indicates that the activation of telomerase is an early and frequent event in OSCC.

Adult↗
PubMed1998

Matrix-assisted laser desorption/ionization for short tandem repeat loci.

Matrix-assisted laser desorption/ionization was used for the detection of four base short tandem repeats (STR) for clinical samples using a time-of-flight mass spectrometer. Since STR plays an important role in genetic disease and human identification, this work indicates that laser desorption mass spectrometry has the potential to achieve rapid DNA typing for both forensic applications and genetic disease diagnosis.

DNA↗
PubMed1998

Use of the scalp as a donor site for large burn wound coverage: review of 150 patients.

The characteristics of rapid wound healing and multiple harvest capacity make the scalp an important donor site when dealing with large and deep burn wounds. This paper reports the results of a retrospective analysis of 150 patients treated for large burn wounds. The findings indicated that bleeding during graft skin harvest could be limited to 50 ml by intradermal injection of epinephrine (1:2,000,000), high-concentration epinephrine-soaked gauze compression (1:20,000), and temporary porcine skin coverage. Use of a scalp graft also carried a low risk of complications, with only four (2.7%) major complications including three cases (2.0%) of visible alopecia and one case (0.7%) of hair transplantation. There were no hypertrophic scars, even in the patient who had the largest number (11) of repeat harvests.

Adolescent↗
PubMed1998

Pancreaticobiliary diseases associated with anomalous pancreaticobiliary ductal union.

BACKGROUND: Anomalous pancreaticobiliary ductal union (APBDU) is associated with different pancreaticobiliary diseases. The aim of this study is to clarify the frequency with which it occurs and its several subtypes in various pancreaticobiliary diseases. METHODS: Radiograms of 1752 subjects who underwent endoscopic retrograde cholangiopancreatography were reviewed independently by two endoscopists. APBDU was diagnosed using recently accepted criteria and divided into B-P and P-B subtypes according to the insertion of biliary and pancreatic ducts. RESULTS: Fifty-nine (8.7%) of 680 subjects with clearly visualized pancreaticobiliary radiograms had APBDU. APBDU was present in 93.8% of patients (15 of 16) with choledochal cyst, 62.5% (5 of 8) with gallbladder cancer, 33.3% (9 of 27) with common bile duct cancer, 50.0% (6 of 12) with gallbladder adenomyomatosis, 13.2% (7 of 53) with biliary pancreatitis, 3.4% (10 of 293) with cholelithiasis, 2.2% (2 of 89) with non-biliary pancreatitis, 2.1% (1 of 47) with hilar cholangiocarcinoma, 1.9% (1 of 54) with pancreatic cancer, and 10.2% (9 of 88) with other miscellaneous disorders. There were 25 patients (42.4%) with the B-P type and 34 patients (57.6%) with the P-B type of APBDU. Patients with choledochal cyst frequently had the B-P type, whereas gallbladder cancer, adenomyomatosis, or biliary pancreatitis frequently coexisted with the P-B type. CONCLUSION: APBDU is relatively common in patients undergoing endoscopic retrograde cholangiopancreatography at our center. There are a variety of pancreaticobiliary diseases that are associated with APBDU. Its role in these conditions is uncertain and needs to be further delineated.

Cholangiopancreatography, Endoscopic Retrograde↗
PubMed1998

Catalase prevents estradiol-induced chondrocyte cytotoxicity.

Osteoarthritis is a common geriatric disease and estrogen may play an important role in this disease. Estradiol may cause chondrocyte damage as suggested by in vitro and in vivo data. One of the possible mechanisms of estradiol-induced chondrocyte damage was thought to be related to free radicals. Whether catalase, a known free radical scavenger, can prevent estradiol-induced chondrocyte damage was tested using a chondrocyte culture system. The results of this study suggest that catalase can significantly reduce the estradiol-induced damage to chondrocytes. Apparently, catalase alters the molecular structure of estradiol as indicated by the absorption spectrum of estradiol with time. The modified estradiol may decrease its toxicity to the chondrocytes. However, the contents of free radicals in the treated chondrocytes have no significant difference from the untreated control cells. Studies to further investigate the mechanism or prevention of estradiol-induced chondrocyte damage in osteoarthritis are warranted.

Animals↗