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Biomedical subjects

S C Wei

Publications and source records attributed to S C Wei.

At least 19 recordsLinked to original sources
PubMed2004

A novel mutation of the DSRAD gene in a Chinese family with dyschromatosis symmetrica hereditaria.

Dyschromatosis symmetrica hereditaria (DSH) is a pigmentary genodermatosis of autosomal dominant inheritance characterized by a mixture of hyperpigmented and hypopigmented macules distributed on the dorsal aspects of the hands and feet. It is caused by mutations of the RNA-specific adenosine deaminase gene. We report the identification of a Chinese family with a three-generation pedigree of DSH, in whom a novel tyrosine substitution mutation in DSRAD was demonstrated: a heterozygous nucleotide A-->G transition at position 2879 in exon 10 of the DSRAD gene was detected.

Adenosine Deaminase↗
PubMed2003

Identification of a locus for porokeratosis palmaris et plantaris disseminata to a 6.9-cM region at chromosome 12q24.1-24.2.

BACKGROUND: Porokeratosis palmaris et plantaris disseminata (PPPD) is a rare autosomal dominant dyskeratotic disorder characterized by a cornoid lamella with parakeratosis, hyperkeratosis and loss of granular layers. The genetic basis of this disease is still unknown. Two loci for disseminated superficial actinic porokeratosis (DSAP) were found to be located on 12q23.2-24.1 and 15q25.1-26.1. Both PPPD and DSAP are disseminated types of porokeratosis. OBJECTIVES: To locate the locus for PPPD, thereby facilitating the identification of this disease gene and leading to an understanding of the pathogenesis of porokeratosis. METHODS: Genotyping was performed in a Chinese family with PPPD using polymorphic microsatellite markers on 12q and 15q. RESULTS: The locus for PPPD is located within a 6.9-cM region between markers D12S1613 and D12S1341, with a maximum two-point LOD score of 8.14 (theta = 0.00) at D12S1335. CONCLUSIONS: This study provides a map location for isolation of a gene causing PPPD.

Adolescent↗
PubMed2001

Diagnosis and management of respiratory tract infections for the primary care physician.

Respiratory tract infections cause nearly half of deaths owing to infectious disease in the United States. This article has discussed the management of several common respiratory tract infections, with an emphasis on appropriate diagnosis and use of antimicrobial agents. Understanding the cause of various respiratory tract infections enables primary care physicians to avoid unnecessary antibiotic use, decreasing adverse effects owing to medications and preventing the rise in antimicrobial resistance.

Acute Disease↗
PubMed2001

Spa contributes to the virulence of type 18 group A streptococci.

Streptococcal protective antigen (Spa) is a newly described surface protein of group A streptococci that was recently shown to evoke protective antibodies (J. B. Dale, E. Y. Chiang, S. Liu, H. S. Courtney, and D. L. Hasty, J. Clin. Investig. 103:1261--1268, 1999). In this study, we have determined the complete sequence of the spa gene from type 18 streptococci. Purified, recombinant Spa protein evoked antibodies that were bactericidal against type 18 streptococci, confirming the presence of protective epitopes. Sera from patients with acute rheumatic fever contained antibodies against recombinant Spa, indicating that the Spa protein is expressed in vivo and is immunogenic in humans. To determine the role of Spa in the virulence of group A streptococci, we created a series of insertional mutants that were (i) Spa negative and M18 positive, (ii) Spa positive and M18 negative, and (iii) Spa negative and M18 negative. The mutants and the parent M18 strain (18-282) were used in assays to determine resistance to phagocytosis, growth in human blood, and mouse virulence. The results show that Spa is a virulence determinant of group A streptococci and that expression of both Spa and M18 is required for optimal virulence of type 18 streptococci.

Amino Acid Sequence↗
PubMed2000

Endoscopy in acquired immunodeficiency syndrome patients with diarrhea and negative stool studies.

BACKGROUND: Diarrhea is a frequent gastrointestinal symptom in patients with acquired immuno-deficiency syndrome (AIDS) and is a major source of morbidity and mortality. A stepwise diagnostic approach is often recommended to search for treatable causes. However, whether the stepwise diagnostic approach is adequate for planning treatment and whether specific treatment for infectious etiologies will affect the survival of patients with AIDS remain unknown. METHODS: From March 1996 to September 1997, endoscopy was performed in AIDS patients with diarrhea, the etiology of which was not identified by noninvasive methods. Specific treatment was given according to the identified etiologies and symptomatic treatment was given for those without definite diagnosis. The clinical symptoms, signs, and duration of follow-up were recorded and survival patterns were analyzed. RESULTS: Etiologic diagnoses were made in 26 of 40 patients (65%) who underwent endoscopic studies. Amebic colitis and cytomegalovirus colitis were the 2 leading causes of prolonged diarrhea in patients with AIDS. Thirty-five patients (87.5%) recovered after treatment. The difference in survival time after diarrhea between patients whose symptoms resolved after treatment and those who continued to have diarrhea was statistically significant (p < 0.001). CONCLUSIONS: Endoscopic studies were helpful for the diagnosis of prolonged diarrhea in AIDS patients who had negative stool studies and did not respond to 2 weeks of empiric treatment. Specific treatment according to the results of endoscopy may improve survival in these patients.

AIDS-Related Opportunistic Infections↗
PubMed2000

[The use of two-route Cisplatin chemotherapy in the treatment of oral squamous cell carcinoma].

OBJECTIVE: To study the feasibility and efficacy of two-route cisplatin chemotherapy for locally advanced squamous cell carcinoma of oral cavity. METHODS: 23 cases with clinical advanced biopsy-proven oral squamous cell carcinoma received intraarterial chemotherapy with cisplatin (DDP), Pingyangmycin (PYM) and 5-fluorouracilum (5-Fu), at the same time intravenous infusion with natrii thiosulfas (STS) for rescue. DDP at 40-60 mg/d, PYM at 16 mg/d and 5-Fu at 500 mg/d were applied for 5-7 consecutive days. RESULTS: 7 cases (33.3%) obtained a complete response (CR), 11(52.4%) had partial response (PR) with an objective response rate (RR) of 85.7%. No severe toxicity was observed, whereas the most frequent grade I and II drug related toxicities were nausea and vomiting. No nephrotoxicity,hepatotoxicity and severe bone marrow suppression were noted. CONCLUSION: Two-route cisplatin chemotherapy is, in our experience,a new,effective and safe therapeutic method for oral squamous cell carcinoma.

English Abstract↗
PubMed1997

Bile duct hamartomas. A report of two cases.

Bile duct hamartomas (von Meyenburg's complexes) of the liver are usually detected at laparotomy or autopsy as an incidental finding, and usually they are multiple. We report two cases of proved bile duct hamartomas of the liver. The first was in a 65-year-old man whose initial sepsis and many hepatic lesions were interpreted as microabscess of the liver. The second patient was a 39-year-old man, a hepatitis B surface antigen carrier, in whom an incidental hepatic tumor was found. We suggest that liver biopsy be done in hepatic lesions with uncertain clinical features, because the histologic findings may change the treatment plan.

Adult↗
PubMed1997

Case report: successful palliative treatment with intraperitoneal OK-432 injection for epithelioid haemangioendothelioma presenting with intractable ascites.

Epithelioid haemangioendothelioma is an unusual type of endothelium-derived vascular tumour of borderline malignancy, which has high variability in clinical presentations, depending on the primary site of involvement. We report on a 20-year-old woman who presented with progressive abdominal fullness for 6 months. Multiple lung and liver nodules with pleural effusion and profuse ascites were found. The diagnosis of epithelioid haemangioendothelioma was made after wedge biopsy of the liver. The ascites was intractable and refractory to strong diuretic therapy and repeated paracentesis. Therefore, six courses of intraperitoneal injection of OK-432 were administered. The ascites subsided to a minimal amount after treatment and the patient remained symptom-free for approximately 8 months. The ascites recurred later and another three courses of intraperitoneal injection of OK-432 were administered. The ascites disappeared again. The patient has remained symptom-free since the end of the second period of treatment.

Adult↗
PubMed1997

Acute pancreatitis complicated by infarction of the spleen and spinal cord.

Complications of acute pancreatitis may include local pancreatic necrosis with pseudocyst or abscess formation, and extrapancreatic manifestations such as pulmonary renal, hepatic, endocrine, and coagulation abnormalities. Coagulation abnormalities associated with acute pancreatitis usually present as thrombophlebitis or widespread microthrombi; most occur in the venous or capillary circulation. We report a rare case of acute pancreatitis complicated by pseudocyst formation, splenic vein thrombosis, splenic infarction, and spinal cord infarction, which resulted in paraplegia. An association between acute pancreatitis and spinal cord infarction has not been reported before.

Acute Disease↗
PubMed1997

Diagnostic role of endoscopy, stool culture, and toxin A in Clostridium difficile-associated disease.

This retrospective study was designed to assess the roles of stool culture for Clostridium difficile, detection of the presence of toxin A, and endoscopic examination in the diagnosis of Clostridium difficile-associated disease (CDAD). From January 1994 through September 1996, there were 213 patients with stool cultures positive for C. difficile in National Taiwan University Hospital. Of these, 126 had CDAD. There were 87 asymptomatic carriers of C. difficile in our study, 12 of whom were positive for toxin A. In addition, seven patients with pseudomembranous colitis (PMC), who were either culture-negative or not tested, were included in the study. The positive predictive values of stool cultures for CDAD and PMC were 59% and 32%, respectively. The positive predictive values of toxin A for CDAD and PMC were 41% and 43%, respectively. Seventy-eight patients (59%) improved with supportive treatment after discontinuing antibiotics. We concluded that stool culture for C. difficile and discontinuation of antibiotics should be the standard approach for patients with suspected CDAD. Endoscopic studies can eliminate some other possible causes of diarrhea such as inflammatory bowel disease, allow biopsies of suspicious lesions, and reveal the severity of CDAD. Toxin assay results need to be interpreted together with the clinical data.

Adolescent↗
PubMed1995

[Cerebrovascular emergencies: difficulties and errors in diagnosing various stroke types].

The frequency of and reasons for errors in diagnosing various types of cerebrovascular disease at the emergency room of National Cheng Kung University Hospital were analyzed in 548 consecutive patients from January to December 1990. Each patient was evaluated by neurological residents and a bedside diagnosis was made on the basis of history-taking, physical examination, and diagnostic reasoning. The emergency diagnosis was made after finishing the radiological and/or laboratory investigations. The tentative emergency diagnosis of each patient was judged as correct or not by comparison with the final diagnosis, which was based on either the results of specific investigation or on the typical cerebrovascular syndrome ascertained by the attending physicians if the specific investigation was not helpful. If the tentative emergency diagnosis had been judged to be wrong, the cause for the misdiagnosis was determined by reviewing the records of the entire diagnostic process. The diagnosis in the emergency setting was erroneous in 131 (24%) patients. Primary intraventricular hemorrhage, cerebral venous thrombosis and subarachnoid hemorrhage were frequently misdiagnosed as compared with other types of stroke. The explored reasons for diagnostic inaccuracy were: inadequate basic data (46%), reasoning errors (38%), and lack of fundamental knowledge (16%). These results implied that the education and training for diagnosis of subarachnoid hemorrhage in emergency should be enhanced. Deeply comatose states caused diagnostic difficulties in data collection. Diagnostic errors were frequently encountered in unusual stroke or stroke with atypical presentations. To increase diagnostic ability in cerebrovascular emergencies, residents should strive to improve interview and examination skills and reasoning discipline. Modern technology is not a panacea for diagnostic difficulties.(ABSTRACT TRUNCATED AT 250 WORDS)

Cerebrovascular Disorders↗
PubMed1994

Bedside diagnosis for neurological residents in neurological emergencies: a retrospective analysis.

BACKGROUND: Critical assessment of diagnostic accuracy is indispensable to resident training and medical education, especially in regard to our situation of the extremely low rate of autopsy. Recent setup of advanced technology for neurological diagnosis has resulted in a tendency to overuse these tools at the expense of using classic bedside diagnostic approach. Disclosing the common errors of daily practices among neurological residents necessitates implementing this pioneer study. METHODS: The tentative diagnosis of each patient, as performed by neurological residents after finishing bedside diagnostic processes, was assessed by final diagnosis concluded from clinical syndrome and/or the results of laboratory studies. The overall rate of diagnostic error and the frequency of diagnostic inaccuracy in various disease entities were evaluated. The reason for the diagnostic error was determined by reviewing the records regarding the entire diagnostic process. RESULTS: 1336 consecutive patients from January 1990 to December 1990 were recruited for this study. The initial bedside diagnosis was correct in 901 (67%) patients. No definite final diagnosis could be obtained in 169 (13%) patients. The diagnoses were incorrect in 266 (20%) patients. The highest rate of inaccuracy was found in the diagnosis of subdural hematoma (56%). The other common diseases of high rate of diagnostic inaccuracy were myasthenia gravis (50%), subarachnoid hemorrhage (42%), Guillain-Barré syndrome (40%), traumatic disorders (39%), herniation of intervertebral disc (33%), metabolic encephalopathy (30%), infection of central nervous system (30%), intracranial neoplasm (24%), drug overdose or intoxication (22%), and mixed neurological and metabolic encephalopathy (21%). The explored reasons for diagnostic inaccuracy were errors of reasoning (38%), inadequate data base (35%), and inadequate fund of knowledge (27%). CONCLUSIONS: This study confirmed that the basic methods of bedside diagnosis with a standardized sequence of history taking, physical examination and diagnostic reasoning are currently still the most fundamental process of achieving an accurate diagnosis in neurological emergencies. No shortcut or mechanical substitute is available for clinical diagnosis.

Diagnostic Errors↗
PubMed1987

Brain L-glutamate decarboxylase: purification and subunit structure.

Glutamate decarboxylase (GDCase; L-glutamate-1-carboxy-lyase, EC 4.1.1.15) was purified from whole rat brain approximately equal to 1300-fold to apparent homogeneity with a specific activity of 2.4 units per mg of protein by a combination of column chromatographies on DEAE-cellulose, hydroxylapatite, and gel filtration, and preparative nondenaturing polyacrylamide gel electrophoresis. The purified preparation contained a single protein band that comigrated with GDCase activity in three diverse analyses: nondenaturing regular (5%) and gradient (3.6-25%) polyacrylamide gel electrophoresis and isoelectric focusing at pH 4-7. The native molecular mass was calculated to be 120 +/- 10 kDa from gradient polyacrylamide gel electrophoresis and 110 +/- 10 kDa from gel filtration. Under the treatment with NaDodSO4 and 2-mercaptoethanol, GDCase dissociated into two subunits of 40 +/- 2 and 80 +/- 4 kDa, as estimated from NaDodSO4 gel electrophoresis. However, only a 40-kDa subunit was detected when GDCase was treated with 4 M urea plus NaDodSO4 and 2-mercaptoethanol, suggesting that the 80-kDa subunit is the dimer of the 40-kDa subunit. In immunoblotting, polyclonal antibodies against GDCase reacted with both 40- and 80-kDa subunits, while monoclonal antibody reacted with only 80-kDa subunits. The isoelectric point of the native enzyme was 5.4. The Km for glutamate was 1.59 X 10(-3) M. In addition to L-glutamate, cysteine sulfinic acid was also decarboxylated at approximately equal to 10% of the rate of glutamate. The pH optimum was fairly broad, with a maximum at approximately equal to 7.3. The enzyme was strongly inhibited by carbonyl-trapping agents, sulfhydryl reagents, thiol compounds, and beta-methylene-DL-aspartate.

Animals↗
PubMed1986

Production and characterization of polyclonal and monoclonal antibodies to rat brain L-glutamate decarboxylase.

Specific monoclonal and polyclonal antibodies to rat brain glutamate decarboxylase (GAD) were produced and characterized. Polyclonal antibodies against GAD were raised in rabbits by injecting a total of 70-210 micrograms of purified GAD i.m. The specificity of anti-GAD serum was established from a variety of tests including Ouchterlony immunodiffusion, immunoelectrophoresis, immunoprecipitation, dot immunoassay, ELISA tests and Western immunoblottings. In immunodiffusion and immunoelectrophoresis tests using partially purified GAD preparations and anti-GAD serum a single, sharp precipitin line corresponding to GAD activity was obtained. Quantitative immunoprecipitation of GAD activity was achieved using anti-GAD IgG and Staphylococcus aureus. Specificity of the antiserum was further indicated from a dot immunoassay and ELISA tests in which the intensity of the reaction product was proportional to the amount of GAD protein present. In the Western immunoblotting experiments using partially purified GAD preparations only two protein bands corresponding to the position of the two subunits of GAD were stained by anti-GAD IgG, further supporting the specificity of polyclonal antibodies against GAD. In addition to polyclonal antibodies, several specific GAD-antibodies-producing clones were also obtained by the hybridoma technique. The specificity of monoclonal antibodies against GAD were established from the following criteria: positive on ELISA test using homogeneous GAD as antigen; formation of GAD--anti-GAD IgG complex as indicated from gel filtration chromatography and sodium dodecyl sulfate polyacrylamide gel electrophoresis; and specific recognition of GAD subunit in a partially purified GAD preparation in Western immunoblotting test. Monoclonal antibodies were further characterized by immunohistochemical localization of known GABAergic neurons and their processes in the cerebellum and retina.

Animals↗
PubMed1984

Immunochemical data suggesting a pattern for the evolution of human placental alkaline phosphatase.

Hyperimmune absorbed rabbit antisera which were reactive with epitopes specific for individual variants of human placental alkaline phosphatase were tested for their reactivity with primate placental alkaline phosphatases. Using the three epitope-specific reactivities defined previously, we found that: epitope I is present in the S-, D- and I-variants of human placental phosphatase, and in the chimpanzee and pygmy chimpanzee placentae; epitope II is present in the F- and 17-variants, and in the Nagao isoenzyme of human placental alkaline phosphatase, and in some orangutan placentae and all spider monkey placentae tested; epitope III is present in the F- and 17-variants, and the Nagao isoenzyme of human placental alkaline phosphatase, and in all the spider monkey placentae and the single squirrel monkey placenta examined. The binding assay was complemented by a competitive radioimmunoassay, which confirmed that the spider monkey placental samples were binding to the same antibody population which bound the human enzymes. The presence of epitopes characteristic of rare human placental phosphatase variants in these remote primate relatives suggests that the rare variants in the current human population have been present during the entire course of evolution. The presence of both epitopes characteristic of the Nagao isoenzyme in spider monkeys suggests that this variant isoenzyme is closely related to the enzyme present in the primate placenta at the time of species divergence (humans and New World monkeys). A hypothetical scheme for this divergence is proposed.

Alkaline Phosphatase↗
PubMed1983

[Transfer of plasmid RP4 into some phytopathogenic bacteria and its relation to their virulence].

Plasmid RP4 were transferred from Escherichia coli into Pseudomonas solanacerum, Xanthomonas campestris pv. oryzae, X. campestris pv. campestris, and X. campestris pv. citri at the frequencies of 1.8 X 10(-6), 2.8 X 10(-6), 1.4 X 10(-2) and 2.0 X 10(-3), respectively. The frequencies of transfer depended on bacterial species and conjugation conditions. Treatment of bromide at the concentration of 2 micrograms/ml and acridine orange at 100 micrograms/ml for 32 hrs the plasmid RP4 could be cured from the transconjugant of P. solanacerum at the frequencies of 75% and 95%, respectively. When transconjugant of P. solanacearum was inoculated into tomato plants, the decrease in virulence was observed, furthermore, no plasmids were detected both in the wild-type strain and the cured transconjugant. It thus appears that the virulence may not be related to plasmids.

Escherichia coli↗