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S C Chang

Publications and source records attributed to S C Chang.

At least 91 records · Page 5Linked to original sources
PubMed2000

Microbiologic features of adult community-acquired bacterial meningitis in Taiwan.

BACKGROUND AND PURPOSE: Community-acquired bacterial meningitis (CABM) is a life-threatening disease that requires prompt initiation of appropriate antibiotic therapy. The purpose of this study was to determine the causative microorganisms of CABM and their antimicrobial susceptibility patterns at a major teaching hospital in Taipei from 1993 to 1998. METHODS: A review of medical records and microbiologic data was used to identify cases of CABM and causative pathogens. Antimicrobial susceptibility testing for bacterial isolates was performed by the disk diffusion method. RESULTS: Among the 48 adult patients with a diagnosis of CABM during the study period, the causative pathogens were identified in 36 cases. Unlike reports from other countries, Klebsiella pneumoniae was the leading causative pathogen (33%), followed by Streptococcus pneumoniae (28%), Listeria monocytogenes (11%), Neisseria meningitidis (6%), Staphylococcus aureus (6%), streptococci (6%), and Pseudomonas aeruginosa (6%). The incidence of CABM due to K. pneumoniae increased during the study period (p = 0.012, Poisson regression), while the incidence of CABM due to other pathogens remained stable. All of the CABM-associated K. pneumoniae isolates were susceptible to cefotaxime but 25% of the CABM-associated S. pneumoniae strains were not susceptible to penicillin G. CONCLUSIONS: Penicillin G alone was not an appropriate empiric therapy for adult CABM because a high percentage of cases were due to K. pneumoniae or penicillin nonsusceptible S. pneumoniae. While the recommendations for the initial empiric regimen for CABM due to S. pneumoniae in Taiwan remain to be developed, third-generation cephalosporins appear to be an appropriate initial empiric regimen for the treatment of CABM due to K. pneumoniae.

Adolescent↗
PubMed2000

Fatal outcome of Erysipelothrix rhusiopathiae bacteremia in a patient with oropharyngeal cancer.

Bacteremia due to Erysipelothrix rhusiopathiae is rare; the most common presentation reported in the literature is endocarditis. We report a 32-year-old man with oropharyngeal cancer who developed aspiration pneumonia and E. rhusiopathiae bacteremia, and presented with fever, chills, dyspnea, and productive cough with purulent sputum. Despite treatment with amoxicillin/clavulanate and nutritional support for 9 days, he died of respiratory failure. He had no clinical evidence of endocarditis. He had no history of animal or occupational exposure, and might have been colonized with E. rhusiopathiae in the oral cavity, followed by aspiration pneumonia and bacteremia. A fatal outcome in a patient with bacteremia due to E. rhusiopathiae without endocarditis is rare.

Adult↗
PubMed2000

Late feeding of dietary fish oil alleviates disease severity and affects macrophage function in autoimmune NZB/W F1 mice.

To investigate the influence of different saturations of dietary fat on autoantibody production and disease courses, autoimmune NZB/NZW F1 (NZB/W F1) mice were fed diets containing 20% palm oil, lard/soybean oil, soybean oil, canola oil or fish oil at 5 months of age. Sera levels of anti-DNA antibodies, proteinuria and life span were followed regularly. In addition, peritoneal resident cells were isolated and mediators such as interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), prostaglandin E2 (PGE2) and NO production were measured. The results show that mice fed a diet containing with fish oil had significantly decreased immunoglobulin G (IgG) anti-single strand (ss) or double strand (ds) DNA antibody levels, lessened proteinuria and prolonged life span compared to mice fed diets containing other types of dietary fat. TNF-alpha and PGE2 levels in mice fed a diet containing fish oil were significantly lower compared to the other dietary groups. IL-6 and NO produced by peritoneal resident cells were significantly higher in mice fed a diet containing lard/soybean oil in comparison with mice of the other groups. Hepatic ex vivo PGE2 level was significantly lower in mice fed fish oil compared to mice of the other dietary groups. These data suggested that dietary fish oil might affect either autoantibody production or macrophage function, contributing to alleviation of the autoimmune process in autoimmune-prone NZB/W F1 mice.

Animals↗
PubMed2000

Efficacy and safety of cefepime in the treatment of serious bacterial infections in hospitalized adult patients.

Proper and timely choice of the antibiotic therapy for the management of infection in hospitalized patients is an immense challenge to the clinician. A newly developed extended-spectrum fourth-generation cephalosporin cefepime, has been shown to have good activity against both gram-positive and gram-negative organisms. In order to further establish the efficacy and safety of cefepime in the treatment of adult hospitalized patients in Taiwan, we reviewed the medical records of all patients who received cefepime therapy for more than 72 h at the National Taiwan University Hospital during the period from January 1999 to April 1999. A total of 55 patients were treated with cefepime during this period. Thirty-two of them were males and 23 were females. Their ages ranged from 16 to 94 years old (average, 67). All had severe infections with a mean Acute Physiology and Chronic Health Evaluation II (APACHE II) score of 18. More than half (56%) of the infections were nosocomial. The most common infections included pulmonary infection (49%), intra-abdominal infection (27%), skin and soft tissue infection (15%), febrile neutropenia (7%), and intravascular device infection (5%). All but one of the patients (98%) had pre-existing medical disease. Malignancy (49%) was the most common underlying illness. Pseudomonas aeruginosa (23 isolates) and Enterobacter cloacae (21) were the most common pathogens causing infections. Thirty-one (58%) of the patients were effectively treated with cefepime. Twenty of the patients died during the study period with most deaths attributable to persistent microbial infection and superinfection, especially Acinetobacter baumannii and fungal infection. Adverse effects developed in six patients, including eosinophilia (3 patients), leukopenia (2), skin rash (1), and drug related fever (1), but all were mild and transient. The results of this study show that cefepime is a safe and effective agent in the treatment of adult patients with severe infection in Taiwan.

Adolescent↗
PubMed2000

Bacteremia due to Campylobacter species: high rate of resistance to macrolide and quinolone antibiotics.

BACKGROUND AND PURPOSE: Although the rate of isolation of Campylobacter from stool specimens in Taiwan is similar to those in other developed countries, Campylobacter bacteremia has rarely been reported in Taiwan, and the patterns of antimicrobial susceptibility of blood isolates to various antimicrobial agents remain unknown in the Taiwanese population. The purpose of this study was to determine the clinical characteristics of patients with Campylobacter infection in a university hospital in Taiwan and the antimicrobial susceptibility patterns of the Campylobacter isolates. METHODS: We retrospectively reviewed medical records of all patients with Campylobacter bacteremia treated in a university hospital between January 1991 and March 1999. Minimum inhibitory concentrations of 13 antimicrobial agents to 10 stored blood isolates were determined using the E-test. RESULTS: Approximately half (52%) of the 21 patients had chronic liver disease and one-quarter had hepatobiliary or gastrointestinal malignancies. Thirteen (62%) patients had conditions that were associated with gastroenteritis. Other clinical manifestations associated with Campylobacter infection included cellulitis, perinatal sepsis, peritonitis, vascular catheter-related infection, and primary bacteremia. The duration of illness was generally short: approximately half (52%) of the 21 patients had fever lasting for only 1 day. Antimicrobial susceptibility testing of the 10 isolates revealed that most of the blood isolates were resistant to erythromycin and nalidixic acid (100% and 90%, respectively), while the rate of cross-resistance between erythromycin and azithromycin was 70%, and that between nalidixic acid and ciprofloxacin was 67%. CONCLUSIONS: Our observations suggest that Campylobacter bacteremia should be included in the differential diagnosis of patients with chronic liver disease or malignancies involving the hepatobiliary system or gastrointestinal tract who present with fever and gastroenteritis. Clinicians in Taiwan should be alert to the high rate of resistance of Campylobacter isolates to macrolide and quinolone antibiotics.

Adolescent↗
PubMed2000

Resolution of refractory hepatic hydrothorax after chemical pleurodesis with minocycline.

Management of refractory hepatic hydrothorax is a challenge to physicians in clinical practice. We reported two patients with hepatic hydrothorax, non-alcoholic cirrhosis and rapidly recurring pleural effusion. They failed to improve with diuretics and repeated thoracentesis. Refractory hepatic hydrothorax was successfully treated by minocycline-induced pleural symphysis. After pleurodesis, ventilatory function returned to normal in both patients. No recurrence of pleural effusion was noted. We suggest that minocycline pleurodesis is an alternative treatment for refractory hepatic hydrothorax because it is simple, safe and effective.

Aged↗
PubMed2000

Infected chylothorax caused by Streptococcus agalactiae: a case report.

Chylothorax is bacteriostatic in nature. Bacterial infection rarely develops in chylothorax and has never been reported in a non-immunocompromised host. A 33-year-old woman was admitted to National Taiwan University Hospital because of fever and right pleuritic pain. Chest roentgenography and computed tomography revealed right pleural effusion. Examination of the pleural effusion revealed a profile compatible with empyema and chylothorax. Culture of the pleural effusion yielded Streptococcus agalactiae. The woman was not immunocompromised. This is the first report of infected chylothorax caused by Streptococcus agalactiae in a non-immunocompromised host.

Adult↗
PubMed2000

Comparison of antimicrobial susceptibility of Citrobacter freundii isolates in two different time periods.

Citrobacter freundii was first identified in 1932, since then it has been reported to cause a variety of infections in aged, immunocompromised, and debilitated patients. With the use of broad-spectrum antibiotics, C. freundii has become increasingly resistant to antimicrobial agents. In order to determine the chronological changes in susceptibility and current susceptibility status of C. freundii, we compared the antimicrobial susceptibility of C. freundii in two different time periods, from 1987 to 1988 and from 1997 to 1998. In both time periods, 61 isolates of C. freundii were randomly selected for study from all clinical isolates at National Taiwan University Hospital. The minimum inhibitory concentrations and susceptible rates of 15 antimicrobial agents were compared, and it was found that most C. freundii isolates were resistant to anti-pseudomonal penicillins, first, second, and third generation cephalosporins, gentamicin, tobramycin, and aztreonam. The results indicate that the susceptible rates of C. freundii to aminoglycosides and ciprofloxacin decreased markedly during the period from 1987 to 1998. Cefepime, cefpirome, imipenem, and meropenem remained the most active agents against C. freundii.

Citrobacter freundii↗
PubMed1999

Invasive amoebiasis: an emerging parasitic disease in patients infected with HIV in an area endemic for amoebic infection.

OBJECTIVES: To describe the incidence and presentations of invasive amoebiasis (IA) in patients with HIV infection in an area endemic for amoebic infection and to assess the role of the indirect haemagglutination (IHA) assay in the diagnosis of IA in HIV-infected patients. DESIGN: Retrospective study of 18 cases of IA and HIV infection. SETTING: A university hospital, the largest centre for management of HIV-associated complications in Taiwan. METHODS: Medical, microbiological and histopathological records of 296 HIV-infected patients and serological data of IHA assay of 126 HIV-infected patients were reviewed to identify cases of IA from 23 June 1994 to 31 March 1999. An IHA titre > or = 1 : 128 was considered positive. Clinical characteristics of HIV-infected patients with IA and without IA were compared. RESULTS: Eighteen of the 296 patients (6.1%) with HIV infection were diagnosed with IA: 12 patients were diagnosed with definite IA and six with probable IA. The clinical manifestations included amoebic colitis (13 patients), amoebic liver abscess (nine), both colitis and abscess (four), and pleural effusion (two). IA was the initial presentation of HIV infection in nine patients. Co-infection with other enteric pathogens was diagnosed in six patients with IA. Compared with the 161 patients without IA who were newly diagnosed with HIV infection, the nine patients with IA had a higher median CD4+ lymphocyte count (202 x 10(6)/l versus 33 x 10(6)/l; P = 0.0017), were less likely to be diagnosed with AIDS (55.6% versus 85.4%; P = 0.039), and had fewer concurrent AIDS-defining illnesses (median number 0 versus 2; P = 0.003). Estimated mean survival duration was not significantly different between the two groups (597 days versus 611 days). Fourteen out of 126 patients (11.1%) had an IHA titre > or = 1 : 128. Of the 18 patients diagnosed with IA, 13 had a titre > or = 1 : 128. The sensitivity of IHA assay in the diagnosis of IA was 72.2% (13 out of 18) and the specificity was 99.1% (107 out of 108). The positive predictive value of IHA test for IA of this patient population was 92.9% (13 out of 14) whereas the negative predictive value was 95.5% (107 out of 112). CONCLUSION: IA is an increasingly important parasitic disease among patients with HIV infection in Taiwan. IHA assay has a good specificity and high negative predictive value in diagnosis of IA.

AIDS-Related Opportunistic Infections↗
PubMed1999

A 12-amino acid stretch in the hypervariable region of the spike protein S1 subunit is critical for cell fusion activity of mouse hepatitis virus.

The spike (S) glycoprotein of mouse hepatitis virus (MHV) plays a major role in the viral pathogenesis. It is often processed into the N-terminal S1 and the C-terminal S2 subunits that were evidently important for binding to cell receptor and inducing cell-cell fusion, respectively. As a consequence of cell-cell fusion, most of the naturally occurring infections of MHV are associated with syncytia formation. So far, only MHV-2 was identified to be fusion-negative. In this study, the S gene of MHV-2 was molecularly cloned, and the nucleotide sequence was determined. The MHV-2 S protein lacks a 12-amino acid stretch in the S1 hypervariable region from amino acid residue 446 to 457 when compared with the fusion-positive strain MHV-JHM. In addition, there are three amino acid substitutions in the S2 subunit, Tyr-1144 to Asp, Glu-1165 to Asp, and Arg-1209 to Lys. The cloned MHV-2 S protein exhibited the fusion-negative property in DBT cells as the intrinsic viral protein. Furthermore, similar to the fusion-positive MHV-JHM strain, proteolytic cleavage activity was detected both in DBT cells infected with the fusion-negative MHV-2 and in the transfected cells that expressed the cloned MHV-2 S protein. Domain swapping experiments demonstrated that the 12-amino acid stretch missing in the MHV-2 S1 subunit, but not the proteolytic cleavage site, was critical for the cell-fusion activity of MHV.

Animals↗
PubMed1999

Engineered recombinant factor VII Q217 variants with altered inhibitor specificities.

Recombinant factor VII with residue 217 (chymotrypsinogen numbering system) converted to alanine (VIIQ217A), glutamic acid (VIIQ217E), or glycine (VIIQ217G) was characterized. In a prothrombin time assay, VIIQ217E demonstrated 100%, VIIQ217A 15%, and VIIQ217G <1% clotting activities relative to wild-type VII. Binding of VIIQ217A and VIIQ217G to TF was comparable to that of wild-type VII to TF. All the variants were readily activated by factor Xa. Autoactivation in the presence of TF was efficient with VIIQ217E, slow with VIIQ217A, but undetected with VIIQ217G. Relative to wild-type VII added at the same concentration, VIIQ217E had no effect on the PT of normal plasma, whereas VIIQ217A slightly and VIIQ217G dramatically prolonged the clotting time in a dose-dependent manner. Activation of macromolecular substrates paralleled this functional inhibition. The k(cat)/K(M) values for factor X activation in the presence of TF were 2.4 for VIIaQ217E as compared to 1.9 (M(-)(1) s(-)(1) x 10(7)) for wild-type VIIa, 1.57 for VIIaQ217A, and 0.05 with VIIaQ217G. In comparison to wild-type VIIa, VIIaQ217E cleaved the chromogenic substrate S2765 (Z-D-Arg-Gly-Arg-pNA) with 10-fold higher k(cat). Analysis of the interactions with the inhibitors TFPI and antithrombin III demonstrated that VIIaQ217A but not VIIaQ217E or VIIaQ217G was inhibited less efficiently by TFPI either in the presence or in the absence of factor Xa. In contrast, VIIaQ217A association with antithrombin III in the presence of heparin was the fastest among the variants with a second-order rate constant of 2.31 (x10(3) M(-)(1) min(-)(1)), as compared to 0.47 and 1.47 for VIIaQ217E and wild-type VIIa, respectively. Our results demonstrate that residue Q(217) is important in regulating substrate and, more importantly, inhibitor recognition by VIIa.

Amino Acid Substitution↗
PubMed1999

Dynamics of plasma cytokine levels in patients with advanced HIV infection and active tuberculosis: implications for early recognition of patients with poor response to anti-tuberculosis treatment.

OBJECTIVE: To examine whether the serial measurement of plasma cytokine levels can assist in the early recognition of AIDS/tuberculosis patients with poor response to anti-tuberculosis treatment. DESIGN: Longitudinal, prospective cohort study. SETTING: A university hospital, the largest centre for HIV/AIDS patients in Taiwan. METHODS: Between January 1997 and September 1998, 25 consecutive patients with advanced HIV infection and suspected tuberculosis were enrolled in the study. Plasma samples were obtained on day 1 (baseline), 3, 7 and 14 of anti-tuberculosis treatment and the levels of tumour necrosis factor-alpha (TNF-alpha) were measured. Patients were classified as either responders or non-responders according to the results of assessment of symptoms and follow-up cultures during the sixth and eighth week of anti-tuberculosis treatment. Thirty consecutive HIV-negative tuberculosis patients were also enrolled in the study. RESULTS: The data of a total of 16 AIDS patients (median CD4 cell count 16 x 10(6)/l; 12 responders and four non-responders) and 21 HIV-negative patients (16 responders and five non-responders), whose tuberculosis was culture-proven, were included for analysis. In responders, TNF-alpha levels declined remarkably within the first week of anti-tuberculosis treatment; however, the decline of TNF-alpha levels in non-responders was significantly less [the median ratio of TNF-alpha level on day 7 to that at baseline was 0.32 versus 0.85 (P < 0.001) in AIDS patients; 0.34 versus 0.80 (P = 0.001) in HIV-negative patients). The lack of a > or = 50% reduction in pre-treatment TNF-alpha levels during the first week of treatment was strongly associated with a poor response to anti-tuberculosis treatment (P = 0.001 in AIDS patients; P < 0.001 in HIV-negative patients). CONCLUSION: Serial measurement of plasma TNF-alpha levels may help to assess the response to anti-tuberculosis treatment in AIDS patients, in spite of very low CD4 cell counts. Failure of TNF-alpha levels to decline by > or = 50 % of pre-treatment levels in the first week of treatment may be an early surrogate marker of a poor response.

AIDS-Related Opportunistic Infections↗
PubMed1999

Isolation of a chinese hamster ovary (CHO) cDNA encoding phosphatidylglycerophosphate (PGP) synthase, expression of which corrects the mitochondrial abnormalities of a PGP synthase-defective mutant of CHO-K1 cells.

Phosphatidylglycerophosphate (PGP) synthase catalyzes the first step in the cardiolipin (CL) branch of phospholipid biosynthesis in mammalian cells. In this study, we isolated a Chinese hamster ovary (CHO) cDNA encoding a putative protein similar in sequence to the yeast PGS1 gene product, PGP synthase. The gene for the isolated CHO cDNA was named PGS1. Expression of the CHO PGS1 cDNA in CHO-K1 cells and production of a recombinant CHO PGS1 protein with a N-terminal extension in Escherichia coli resulted in 15-fold and 90-fold increases of PGP synthase specific activity, respectively, establishing that CHO PGS1 encodes PGP synthase. A PGP synthase-defective CHO mutant, PGS-S, isolated previously (Ohtsuka, T., Nishijima, M., and Akamatsu, Y. (1993) J. Biol. Chem. 268, 22908-22913) exhibits striking reductions in biosynthetic rate and cellular content of phosphatidylglycerol (PG) and CL and shows mitochondrial morphological and functional abnormalities. The CHO PGS-S mutant transfected with the CHO PGS1 cDNA exhibited 620-fold and 7-fold higher PGP synthase activity than mutant PGS-S and wild type CHO-K1 cells, respectively, and had a normal cellular content and rate of biosynthesis of PG and CL. In contrast to mutant PGS-S, the transfectant had morphologically normal mitochondria. When the transfectant and mutant PGS-S cells were cultivated in a glucose-depleted medium, in which cellular energy production mainly depends on mitochondrial function, the transformant but not mutant PGS-S was capable of growth. These results demonstrated that the morphological and functional defects displayed by the PGS-S mutant are due directly to the reduced ability to make normal levels of PG and/or CL.

Amino Acid Sequence↗
PubMed1999

Cutaneous mastocytomas in the neotenic caudate amphibians Ambystoma mexicanum (axolotl) and Ambystoma tigrinum (tiger salamander).

Spontaneous mastocytomas studied in 18 axolotls (Ambystoma mexicanum) and six tiger salamanders (Ambystoma tigrinum) were gray-white, uni- to multilobular cutaneous protrusions from 2 mm to 2 cm in diameter. Tumors were moderately cellular unencapsulated masses that usually infiltrated the dermis and hypodermis with the destruction of intervening tissues. Some tumors were invading superficial bundles of the underlying skeletal muscle. Tumors consisted of mitotically active cells derived from a single lineage but showing a range of differentiation. Immature cells had nearly smooth to lightly cleft or folded basophilic nuclei bordered by a band of cytoplasm with few cytoplasmic processes and containing a few small uniform eccentric granules. Mature cells had basophilic nuclei with deep clefts or folds and abundant eosinophilic cytoplasm with multiple long intertwining cytoplasmic extensions packed with metachromatic granules. The axolotls were old individuals from an inbred laboratory colony. The tiger salamanders were wild animals from a single polluted pond. They could have been old and inbred. Both groups were neotenic. These are the first mastocytomas discovered in cold-blooded animals.

Ambystoma↗
PubMed1999

Recombinant human leukemia inhibitory factor enhances the development of preimplantation mouse embryo in vitro.

OBJECTIVE: To assess the effect of recombinant human leukemia inhibitory factor (rhLIF) on mouse embryos in vitro. DESIGN: Controlled prospective study. SETTING: Academic research environment. ANIMAL(S): Female CB6F1 mice between 6 and 8 weeks old. INTERVENTION(S): Mice were divided randomly into three groups, which included a control group in an in vivo study (group I) and two groups in an in vitro study (groups II and III). Mice were killed at 116-120 hours (group I) and 44-48 hours (groups II and III) after hCG injection. Two-cell embryos (groups II and III) and blastocysts (group I) were obtained. Embryos in group II were cocultured with human tubal fluid (HTF) + 0.5% human serum albumin and in group III with HTF + rhLIF (1,000 U/mL) under paraffin oil. MAIN OUTCOME MEASURE(S): The embryonic numbers in different stages were recorded and compared. RESULT(S): Similar early embryo development to the four- to eight-cell and morula stages was noted between groups II and III (87.3% versus 91.0% and 74.6% versus 87.1%, respectively). However, further embryo development to the blastocyst, expanded blastocyst, and hatching blastocyst in group II (48.1%, 31.7%, and 18.5%, respectively) was lower than that in group III (83.6%, 53.7%, and 37.8%). CONCLUSION(S): RhLIF does not provide obvious stimulation in the early mouse embryo. However, rhLIF has positive effects on preimplantation blastocyst growth, differentiation, and hatching.

Animals↗
PubMed1999

In vitro activity of quinupristin/dalfopristin against clinical isolates of common gram-positive bacteria in Taiwan.

The MICs of quinupristin/dalfopristin against common Gram-positive bacteria isolated from various clinical specimens at a university hospital in Taiwan were determined by the agar dilution method. The tested bacteria included methicillin-resistant Staphylococcus aureus (MRSA), methicillin-susceptible S. aureus (MSSA), methicillin-resistant Staphylococcus epidermidis (MRSE), methicillin-susceptible S. epidermidis (MSSE), Streptococcus pyogenes, Streptococcus pneumoniae, and Enterococcus faecalis. With the exception of E. faecalis all bacteria were susceptible to quinupristin/dalfopristin. The MIC50 and MIC90 were, respectively, 0.25 microgram/mL and 0.5 microgram/mL for both MRSA and MSSA; 0.25 microgram/mL and 0.5 microgram/mL for MRSE; 0.25 microgram/mL and 0.25 microgram/mL for MSSE; 0.125 microgram/mL and 0.125 microgram/mL for S. pyogenes; and < or = 0.03 microgram/mL and 0.25 microgram/mL for S. pneumoniae. Eighty-two percent of the tested E. faecalis isolates were intermediately resistant or resistant to quinupristin/dalfopristin, with an MIC50 of 2 micrograms/mL and an MIC90 of 4 micrograms/mL. Quinupristin/dalfopristin seems to be a promising antimicrobial agent against common Gram-positive bacteria other than E. faecalis in Taiwan.

Anti-Bacterial Agents↗