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Biomedical subjects

W C Hsieh

Publications and source records attributed to W C Hsieh.

At least 55 records · Page 3Linked to original sources
PubMed1996

Nosocomial candidemia in a university hospital in Taiwan.

The incidence of nosocomial candidemia increased 27-fold over the past 13 years at National Taiwan University Hospital. In order to investigate its predisposing factors, clinical manifestations and prognostic determinants, a prospective observational study of nosocomial candidemia was undertaken at the hospital. From 1 May 1994 to 30 April 1995, 118 consecutive adult patients with 120 Candida spp blood isolates were analyzed. Clinical presentations included fever (100%) with a median duration of 3 days, diarrhea within 7 days of candidemia (27.9%) and macronodular skin emboli (7.6%). Laboratory studies showed worsening azotemia (35.6%), elevation of aminotransferase (28.3%), leukocytosis (27.1%) and thrombocytopenia (23.3%). Use of multiple antibiotics, retained vascular catheters and parenteral nutritional support were the three most common predisposing factors for candidemia. C. albicans was the most common isolate (50%), followed by C. tropicalis (20%), C. glabrata (14%), C. parapsilosis (9.2%). C. guilliermondii (2.5%), and C. Krusei (1.7%). C. tropicalis was more frequently the cause of candidemia in patients with leukemia and neutropenia, while C. glabrata was more commonly seen in patients receiving fluconazole prophylaxis. A severity scoring system adopted from prospective bacteremia studies proved to be highly predictive of mortality in candidemic patients. The overall case fatality rate was 70/118 (59.3%), and 51/70 (72.9%) were attributable to candidemia. In a multivariate analysis, the prognostic factors adversely influencing outcome were: higher severity scores, no removal of the catheter, persistent candidemia and lack of antifungal therapy.

Adult↗
PubMed1996

Clinical manifestations, microbiology and prognosis of 42 patients with necrotizing fasciitis.

Forty-two cases of necrotizing fasciitis (NF) surgically confirmed between January 1991 and October 1995 were retrospectively reviewed. This was done in order to describe the underlying diseases, clinical presentations, etiology and outcome of NF and to assess the prognostic value of a simplified severity scoring system. The system scores changes in consciousness status, body temperature, blood pressure and ventilation to determine the likely outcome of NF. Twenty-five men and 17 women with a median age of 51 years (range, 17-87 yr) were included. Diabetes mellitus (57.1%) was the most common underlying disease. The mean duration of symptoms before admission was 8 days (median, 7 d; range, 1-30 d). The extremities (66.7%) were most commonly involved. Initial clinical presentations within 48 hours of admission included skin erythema and swelling at the affected site (97.6%), pyrexia (61.9%), hypotension (33.3%), altered consciousness (28.6%), bullous lesions (26.2%) and crepitus (9.5%). The mean number of isolated pathogens was 1.8 (range, 0-6). Eight patients had mixed aerobic and anaerobic infections. The attributable case fatality rate was 23.8%. Higher severity score (> or = 4 points), hypotension, altered consciousness, respiratory failure requiring ventilator support, elevation of alanine aminotransferase levels > twofold, serum creatinine > 177 mumol/L, thrombocytopenia (< 100 x 10(9)/L), and worsening symptoms and signs within 48 hours of admission were associated with higher fatality rates (p < 0.05).

Adolescent↗
PubMed1995

Influence of beta-lactamase inhibitors on the activity of oxacillin against methicillin-resistant Staphylococcus aureus.

We studied the in vitro susceptibility to oxacillin of 46 isolates of methicillin-resistant Staphylococcus aureus (MRSA) isolates with a minimum inhibitory concentration (MIC) > 8 micrograms/ml of oxacillin, with and without adding clavulanic acid, sulbactam, or tazobactam in three different concentrations (2, 4, and 8 micrograms/ml). All 46 strains were found by the rapid chromogenic cephalosporin method to be beta-lactamase producers. For those strains with low-level resistance (MIC of 16 or 32 micrograms/ml), the MICs of oxacillin decreased four- to 32-fold and two- to 32-fold after adding sulbactam and tazobactam, respectively. For those with high-level resistance (MIC of > or = 64 micrograms/ml), the MICs either did not change or decreased only two-fold after we added one of three beta-lactamase inhibitors. The results suggest that beta-lactamase production probably plays a role in resistance to oxacillin in those MRSA strains of low-level oxacillin resistance.

Anti-Bacterial Agents↗
PubMed1995

In vitro activities of antimicrobial agents, alone and in combination, against Acinetobacter baumannii isolated from blood.

In vitro activities of 15 antimicrobial agents against 90 strains of Acinetobacter baumannii isolated from blood cultures from hospitalized patients were determined using the agar dilution method. Imipenem, ofloxacin, and ciprofloxacin had the best antimicrobial activity with minimum inhibitory concentrations (MIC50s) of 0.25 mu g/ml and MIC90s of 0.5-1 mu g/ml. beta-lactam antibiotics other than imipenem had poor activity, with MIC50s ranging from 8 to 64 mu g/ml and MIC90s from 32 to > or = 256 mu g/ml. The checkerboard titration method was used to study the effects of combination of two antimicrobial agents. Combinations of ceftazidime, aztreonam, imipenem, or ciprofloxacin with amikacin showed either synergistic effects or partial synergistic effects for 40.9%-86.4% of 22 tested strains. The best in vitro activity was observed with the combination of imipenem and amikacin. No antagonistic effects were observed with the combination of imipenem and amikacin. Synergistic effects were confirmed by time-kill curve studies. In conclusion, imipenem, ofloxacin, and ciprofloxacin were the three most active agents against human blood isolates of A. baumannii. The combination of a beta-lactam or ciprofloxacin with amikacin was synergistic for some of the isolates.

Acinetobacter↗
PubMed1995

Macrolides resistance of common bacteria isolated from Taiwan.

To determine the susceptibility to macrolides of common pathogenic bacteria isolated from Taiwan, the in vitro activities of erythromycin, roxithromycin, azithromycin, clarithromycin, and dirithromycin were tested against 492 clinical isolates of eight different bacteria, collected from the National Taiwan University Hospital. The results showed high minimum inhibitory concentrations (MICs) against most of the tested bacteria. The MIC90s for Staphylococcus aureus (both methicillin-resistant and -sensitive strains), coagulase-negative staphylococci (both methicillin-resistant and -sensitive strains), Streptococcus pyogenes, Streptococcus pneumoniae, enterococci, peptostreptococci, and Bacteroides fragilis were all > or = 256 micrograms/ml. The MIC50s for methicillin-resistant strains of S. aureus and coagulase-negative staphylococci, and enterococci were > or = 256 micrograms/ml. For S. pneumoniae, peptostreptococci, and B. fragilis, the MIC50s were > 8 micrograms/ml. The resistance rates to macrolides were 80% or more in methicillin-resistant staphylococci and about 30% in methicillin-sensitive staphylococci. Around 55% of S. pneumoniae strains and 37 approximately 42% of S. pyogenes strains were resistant to macrolides. Cross-resistance to different macrolides was clearly demonstrated in most of the resistant strains.

Anti-Bacterial Agents↗
PubMed1995

Trichosporon beigelii fungemia in patients with acute leukemia: report of three cases.

Trichosporon beigelii fungemia with localized visceral involvement or dissemination is a life-threatening infection in patients with granulocytopenia. We report three cases of T. beigelii fungemia in patients with acute leukemia seen at the National Taiwan University Hospital. Two patients were in the granulocytopenic state after cytoreductive chemotherapy, while one was in complete remission. Fever persisted or recurred despite conventional antibiotic treatment when fungemia developed. Cutaneous trichosporonosis was noted in one patient, which was misdiagnosed as candidiasis. An indwelling catheter constituted the likely portal of entry in two patients. Therapeutic response to amphotericin B is generally not achieved in patients without recovery of neutrophil counts and in those with retained catheters.

Adolescent↗
PubMed1995

In Vitro antimicrobial susceptibilities of Streptococcus pneumoniae isolated from two teaching hospitals in Taiwan, 1989-1995.

The susceptibility of 46 pneumococcal isolates collected during October 1989 to May 1995 from National Taiwan University Hospital and Taipei Municipal Yang Ming Hospital was studied. Among these isolates, the resistant rate of penicillin G was 21.7%; the penicillin G-resistant strains were more frequently resistant than the penicillin-sensitive strains to other beta-lactam antimicrobial drugs. The minimum bactericidal concentrations (MBCs) of penicillin G for all isolates were equal to, or one dilution higher than, minimum inhibitory concentrations (MICs). Three strains were false positive for penicillin resistance among isolates of Streptococcus pneumoniae screened with oxacillin. On the other hand, resistance to penicillin G was often independent of resistance to erythromycin. Vancomycin was the most active agent tested.

Humans↗
PubMed1995

[Secular trends in the etiology of nosocomial infection at a teaching hospital in Taiwan, 1981-1994].

Surveillance system of nosocomial infection was established in 1980 at the National Taiwan University Hospital (NTUH). To identify pathogens and the secular trends in the etiology of nosocomial infection from 1981 to 1994, the prospective, hospital-wide nosocomial surveillance data were analysed. During this period, 22,146 pathogens causing nosocomial infections were isolated. Gram-negative aerobic bacteria remained the major pathogens, but gram-positive cocci and fungi increased rapidly in the past 14 years. When the overall pathogen distribution is examined, Pseudomonas areuginosa was the most frequently isolated pathogen, but Candida albicans and other yeasts have taken the leading position since 1993. Staphylococcus aureus and coagulase-negative staphylococci also increase significantly in recent years. When the pathogens causing infection at the 4 major sites were examined. P. aeruginosa was the pathogen most often associated with respiratory tract and surgical wound infections. In blood stream and urinary tract infections, we observed Escherichia coli was replaced by C. albicans and other yeasts as a most common isolate in these years. In addition, C. albicans and other yeasts and methicillin-resistant S. aureus (MRSA) are emerging as major nosocomial pathogens at NTUH. C. albicans and other yeast increased from 1.8% in 1981 to 14.9% in 1994 in the overall nosocomial infection. The increase was found in the blood stream (2.1% to 16.2%) and urinary tract infections (5.4% to 24.7%). Of 1,742 nosocomial S. aureus isolates, the percentage of MRSA rose from 12.5% in 1981 to 55.2% in 1994. The high percentage of MRSA was observed at 4 major anatomic sites of infection. In summary, significant shifts in the pathogens of nosocomial infection have occurred in the past 14 years at NTUH, and the distribution of nosocomial pathogens was similar to those reported in the United States in recent years.

Bacteremia↗
PubMed1994

Invasive pulmonary pseudallescheriasis with direct invasion of the thoracic spine in an immunocompetent patient.

Most invasive pseudallescheriasis infections have occurred in immunocompromised patients. The case of an immunocompetent patient with invasive pulmonary pseudallescheriasis and subsequent contiguous extension to the ribs and spine is reported. Aspergillosis was mistakenly diagnosed on histopathologic examination of the debrided tissue. Culture of the debrided tissue yielded Pseudallescheria boydii.

Aged↗
PubMed1994

Fluoroquinolone resistance among methicillin-resistant staphylococci after usage of fluoroquinolones other than ciprofloxacin in Taiwan.

The antimicrobial susceptibility to norfloxacin, ofloxacin, and ciprofloxacin of methicillin-resistant staphylococci isolated before and after the use of fluoroquinolones other than ciprofloxacin in Taiwan was studied by the agar dilution method. Before the use of fluoroquinolones, 54 isolates of methicillin-resistant Staphylococcus aureus (MRSA) and 51 isolates of methicillin-resistant coagulase-negative staphylococci (MRCNS) isolated in 1983-1985 were all susceptible to the three fluoroquinolones tested. Following the use of norfloxacin, enoxacin, and ofloxacin, the MIC90s of norfloxacin, ofloxacin, and ciprofloxacin against 46 isolates of MRSA collected during 1989-1990 increased to 64, 16, and 32 micrograms/ml, respectively, and the rates of resistant strains to these three agents were 37.0%, 30.4%, and 34.8%, respectively. The MIC90s against 42 isolates of MRCNS also increased to 64, 8, and 8 micrograms/ml, respectively, with 35.7%, 23.8%, and 33.3% resistant strains.

Anti-Infective Agents↗
PubMed1994

Plasmodium vivax infection in a renal transplant recipient: report of a case.

A patient with end-stage renal disease who acquired Plasmodium vivax infection after renal transplantation is reported. This 24-year-old male, a native of Taiwan, had chronic renal failure due to nephrotic syndrome of unknown etiology and had been maintained on regular hemodialysis. He developed a fever 18 days after receiving a blood transfusion and a renal allograft transplant from unknown donors in India, while he was taking corticosteroids, azathioprine and cyclosporine. Ring forms, schizonts and trophozoits of P. vivax were found in the patient's peripheral blood. He achieved defervescence after a three-day treatment of chloroquine. Malaria should be considered in the differential diagnosis of fever in transplant recipients who have received organs or blood products from an area of endemic malaria.

Adult↗
PubMed1994

Age-period-cohort analysis of pulmonary tuberculosis mortality in Taiwan: 1961 to 1990.

The specific aim of this study was to examine the effects of age, calendar period of death, and birth cohort in pulmonary tuberculosis (TB) mortality in Taiwan during the period 1961 to 1990. A log-linear Poisson regression model modified from the method of Osmond and Gardner was used and 79,881 deaths (58,025 males and 21,856 females) were included in the analysis. Birth cohort is the most significant predictor of pulmonary TB mortality according to the model. The earliest birth cohort from 1891 had a pulmonary TB mortality 17,327 and 6,186 times those born from 1986 for males and females, respectively. There was also a significant age effect. The youngest age group of zero to four years had a pulmonary TB mortality 7.10 and 5.87 times those for the age group of five to nine years for males and females, respectively. The oldest age group of 70 to 74 years had a risk of pulmonary TB mortality 2.89 and 1.88 times those for the five- to nine-year age groups for males and females, respectively. Parameters of the period factor showed a decreasing pulmonary TB mortality from 1961 to 1990 that was less significant than those of age or cohort. In addition to the improvement in medical measures that influenced the effect of calendar year on TB mortality, year of birth is an important determinant in the trend of TB mortality in Taiwan. The result shows that the major focus for TB mortality in Taiwan is in the age groups born between 1891 and 1921.

Adolescent↗
PubMed1994

Non-spinal psoas abscess due to Mycobacterium tuberculosis in a patient with acquired immunodeficiency syndrome: report of a case.

Of the 36 patients with human immunodeficiency virus (HIV) infection admitted to our institution since 1985, one had a non-spinal psoas abscess due to Mycobacterium tuberculosis without pulmonary involvement. A 32-year-old male homosexual had prolonged fever and weight loss for two months. Serologic tests for antibodies against HIV were positive. A characteristic hypodense lesion within the right psoas muscle was noted by computerized tomographic (CT) scanning. Diagnosis of psoas abscess was confirmed by ultrasound-guided needle aspiration. The smear of the aspirated pus showed numerous acid-fast bacilli and cultures grew M. tuberculosis. The lesion responded rapidly to antituberculous therapy and a follow-up CT scan 10 months later showed improvement.

AIDS-Related Opportunistic Infections↗
PubMed1994

[Family influence on cancer screening participation in seven communities in Taiwan].

Cancer is the leading cause of death in Taiwan. Since there is no definitive method for cancer prevention, early detection play a major role in fighting cancer. Factors that affect people's willingness to participate cancer screening have been discussed widely except for those relating to the family. The family's role in motivation & influencing its members to participate in an invited cancer-screening program was studied in seven Taiwanese communities. 5% of participants in each area for both genders were chosen by stratified random sampling, and matched with teice-informed nonparticipants who were chosen by sex, age, and neighborhood. By means of a home visit and structured questionnaire, 729 of the 987 eligible cases were interviewed (73.9%). The main findings were that the response was higher among people with higher education, nonsmokers, and those who felt the scheduled time and place of attendance was suitable and convenient. Moreover, in the 6 variables related to family (family structure, family life cycle, cancer history in family and friends, family APGAR, family support about health problems, and family's opinion about cancer screening), the last 4 variables were found to be significantly related by chi-square analysis to the attendance. Finally, a logistic regression analysis adjusted by age, sex, education, smoking habits, time available and traffic factors was used to analyze how family factors affect attendance. The result was cancer history in family and friends (odd ratio = 2.42) and family's encouragement (odd ratio = 1.85) had a positive association.

Adult↗
PubMed1993

In vitro antimicrobial activity of fluoroquinolones against clinical isolates obtained in 1989 and 1990.

The in vitro activity of nine fluoroquinolones, enoxacin, norfloxacin, ofloxacin, ciprofloxacin, lomefloxacin, tosufloxacin, sparfloxacin, fleroxacin and levofloxacin, and two earlier quinolones, nalidixic acid and pipemidic acid, against 1,346 bacterial strains isolated clinically between 1989 and 1990, was evaluated by agar dilution method. The bacteria studied were Staphylococcus aureus (including methicillin-susceptible and -resistant strains), Staphylococcus epidermidis, Enterococcus species (including high-level gentamicin-resistant strains), Escherichia coli, Salmonella species, Proteus mirabilis, Proteus vulgaris, Morganella morganii, Klebsiella pneumoniae, Enterobacter cloacae, Serratia marcescens, Citrobacter spp., Pseudomonas aeruginosa, Pseudomonas cepacia, Acinetobacter baumannii, and Bacteroides fragilis. In contrast to the moderate to poor activity of two earlier quinolones, the fluoroquinolones acted well against most Enterobacteriaceae and A. baumannii. The minimum inhibitory concentrations for 90% of the drug strains (MIC90s) were < 1 microgram/mL against most tested species. Ciprofloxacin, tosufloxacin, sparfloxacin, and levofloxacin were more effective against multi-drug-resistant nosocomial pathogens. All fluoroquinolones assayed were very active against methicillin-susceptible S. aureus, with MIC90s < or = 1 microgram/mL. For methicillin-resistant strains, on the other hand, the MIC90s were > or = 4 micrograms/mL. There was no significant difference in fluoroquinolone susceptibility between methicillin-susceptible and -resistant S. epidermidis. Sparfloxacin, tosufloxacin, ciprofloxacin and levofloxacin were more active against enterococci. Most fluoroquinolones were relatively inactive against B. fragilis, with the exception of tosufloxacin, sparfloxacin and levofloxacin. The MIC90s of most quinolones assayed against K. pneumoniae, Citrobacter spp., E. cloacae, S. aureus and S. epidermidis were at least four-fold higher in our study. Therefore, it is important for physicians to use fluoroquinolones carefully so as to prevent or delay the emergence of resistant strains.

Anti-Infective Agents↗
PubMed1993

Antimicrobial susceptibility of enterococci in vitro.

Treating patients with enterococcal infections has become difficult because of the emergence of several resistant traits in the past decade, including high-level resistance to gentamicin, beta-lactamase production, non-beta-lactamase-associated penicillin resistance and vancomycin resistance. To determine the antimicrobial susceptibility and to survey the antibiotic resistance of enterococci, we tested 111 clinical isolates of enterococci from the National Taiwan University Hospital from 1990 to 1991. There were 102 isolates of Enterococcus faecalis, five of Enterococcus faecium, and four of other enterococcal species. All these isolates were tested in vitro by the agar dilution method for determination of the minimal inhibitory concentration (MIC), by the broth microdilution test for screening of high-level resistance to gentamicin and by the rapid chromogenic cephalosporin method for detection of beta-lactamase production. The effect of the combination of two antimicrobial agents against 20 of the 111 isolates, including strains with high-level and low-level resistance to gentamicin, were further checked by the checkerboard titration method. Among 17 antimicrobial agents, the most active agent was ampicillin, followed by vancomycin, ciprofloxacin, ofloxacin and penicillin. Although none included in these were beta-lactamase producers or vancomycin-resistant strains, there was a high proportion (62%) with high-level resistance to gentamicin among our isolates. There were 11 isolates, seven Enterococcus faecalis and four Enterococcus faecium, which had MICs beyond the clinically achievable level of penicillin (MIC > or = 64 micrograms/mL). Because these resistant isolates of enterococci have important therapeutic implications, periodic surveillance and MIC testing are suggested.

Anti-Bacterial Agents↗