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Biomedical subjects

W C Hsieh

Publications and source records attributed to W C Hsieh.

At least 19 recordsLinked to original sources
PubMed2001

Baicalein induces a dual growth arrest by modulating multiple cell cycle regulatory molecules.

Baicalein, a flavonoid present in the root of Scutellaria baicalensis Georgi, has been reported to inhibit cell proliferation in several types of cells. In this study, the effect of baicalein on cell growth and the mechanism of growth modulation were examined in primary cultured rat heart endothelial cells. Here, we report that treatment with 100-microM baicalein caused an almost complete inhibition of cell proliferation after 5 days of incubation. Baicalein mediated G1 and G2 growth arrest accompanied by the down-regulation of cyclin D2, cyclin A, cyclin-dependent kinase 1 (Cdk1) and cyclin-dependent kinase 2 (Cdk2), and up-regulation of p15(Ink4B), p21(CIP1/Waf1), p53 and cyclin E. Evaluation of the kinase activity of cyclin-Cdk complexes showed that baicalein decreased Cdk1, Cdk2, cyclin D2 and cyclin A expression in endothelial cells, leading to markedly reduced Cdk/cyclin-associated kinase activities. These results suggest that baicalein inhibits the proliferation of rat heart endothelial cells via G1 and G2 arrest in association with the down-regulation of the expression and function of Cdk1, Cdk2, cyclin D2 and cyclin A proteins, and up-regulation of cyclin E, p15(Ink4B), p53 and p21(CIP1/Waf1).

Animals↗
PubMed2001

In vitro activity of linezolid against clinical Gram-positive bacterial isolates from Taiwan: an area with a high prevalence of antibiotic resistance.

The prevalence of antibiotic-resistant bacteria in Taiwan is due to the heavy use of antimicrobial agents in both animal husbandry and clinical practice over the past decades. Minimum inhibitory concentrations (MICs) of linezolid were established for 371 clinical isolates of staphylococci, pneumococci, enterococci and group A streptococci from Taiwan. All isolates tested including those resistant to beta-lactams, erythromycin, vancomycin and quinupristin-dalfopristin were uniformly susceptible to linezolid, with MICs ranging from 0.125 to 2 mg/l. Our data support the observation that there is no cross-resistance between linezolid and other classes of antimicrobial substances.

Acetamides↗
PubMed2001

Paraneoplastic pemphigus in association with a retroperitoneal Castleman's disease presenting with a lichen planus pemphigoides-like eruption. A case report and review of literature.

A 50-year-old man presented with severe mucosal erosions of the lips, oral cavity and perianal area, a lichen planus-like eruption on the trunk and extremities and scaly plaques of the palms and soles. The clinical impression was of Stevens--Johnson syndrome, or paraneoplastic pemphigus (PNP). Histopathology revealed vacuolar interface and lichenoid dermatitis with dyskeratosis and suprabasal acantholytic vesiculation. Direct immunofluorescence showed deposition of IgG in the intercellular space and linear deposition of C3 along the basal membrane zone. Indirect immunofluorescence revealed circulating IgG with intercellular staining of the epithelium of rat urinary bladder. Western blotting demonstrated bands of 250- and 230-kDa antigens. The clinical, histological and immunological features were consistent with the lichen planus pemphigoides variant of PNP. A retroperitoneal hyaline-vascular Castleman's disease was detected and excised. The skin lesions worsened initially after tumour resection but improved gradually, leaving extensive melanosis after cyclosporin and mycophenolate mofetil treatment.

Castleman Disease↗
PubMed2000

In vitro aberrant gene expression as the indicator of lead-induced neurotoxicity in U-373MG cells.

Lead is an important neurobehavioral toxicant and may interfere with developmental processes in the brain resulting in impairment of its functions. U-373MG, a human glioma cell line, was cultured in Dulbecco's modified Eagles' medium supplemented with either 20 or 10% FBS (fetal bovine serum) to explore the possible indications for lead-induced toxicity. Although lead did not affect cell growth rate in concentrations ranging from 0.01 to 10 microM, it substantially altered gene expression analyzed by reverse-transcription polymerase chain reaction. With 10% FBS culture, lead affected the gene expression in a dose-dependent relationship. It enhanced the expression of tumor necrosis factor-alpha (TNF-alpha), but decreased those of interleukin-1beta (IL-1beta), interleukin-6 (IL-6), gamma-aminobutyric acid (GABA) transaminase, and glutamine synthetase. With 20% FBS culture, lead also profoundly increased TNF-alpha and IL-1beta; however, it did not extensively affect the other genes examined above. Thus, the highly sensitive changes of gene expression of these cytokines or metabolic enzymes after treatments with lead acetate evidenced their usefulness as indicators for in vitro measurement of lead-induced neurotoxicity.

Brain Neoplasms↗
PubMed2000

High prevalence of antibiotic resistance of common pathogenic bacteria in Taiwan. The Antibiotic Resistance Study Group of the Infectious Disease Society of the Republic of China.

We analyzed the antimicrobial susceptibilities of all clinical isolates of 14 common pathogenic bacteria recovered from patients in eight medical centers in Taiwan during 1995 and 1996. Susceptibility to commonly used antimicrobial agents was tested by the disk diffusion method as recommended by the National Committee for Clinical Laboratory Standards. Of the Staphylococcus aureus isolates, 59.3% and 62% were oxacillin-resistant in 1995 and 1996, respectively, whereas 63.2% of the coagulase-negative staphylococci isolates during the study period were oxacillin-resistant. The rate of penicillin-resistance among Streptococcus pneumoniae isolates was 39.7% in 1995 and 53.7% in 1996. Macrolide-resistance was found in 71.4%, 42.1%, and 46.7% of S. pneumoniae, beta-hemolytic streptococci, and viridans streptococci, respectively, in 1996. Less than 2% of the enterococcal isolates were vancomycin resistant, but 77% of them were gentamicin resistant. Resistance to gentamicin was also common in Enterobacteriaceae, Pseudomonas aeruginosa, and Acinetobacter baumannii. Various degrees of resistance to ampicillin, piperacillin, cephalosporins, aztreonam, and ciprofloxacin were detected in Enterobacteriaceae, P. aeruginosa, and A. baumannii. More than 55% of Haemophilus influenzae isolates were ampicillin resistant. In summary, resistance to many antimicrobial agents in various common pathogenic bacteria is very common in Taiwan. Our results implicate that antibiotic resistance in the developing countries need to be monitored closely.

Cross Infection↗
PubMed2000

Clinical features and in vitro susceptibilities of two varieties of Cryptococcus neoformans in Taiwan.

One hundred years after introduction of the Eucalyptus tree to Taiwan, a predominantly subtropical island, we analyzed clinical and microbiological data of 59 patients with Cryptococcus neoformans infection hospitalized at National Taiwan University Hospital during 1982 to 1997. There were 38 (64.4%) cases of cryptococcosis caused by the var. neoformans and 21 (35.6%) caused by the var. gattii. Thirty-three patients (55.9%) had impaired T cell function, which included 12 patients with acquired immunodeficiency syndrome (AIDS). Eleven of the 12 patients with AIDS were diagnosed after 1995, and 11 cases were caused by var. neoformans. Minimum inhibitory concentrations (MICs) determined by the NCCLS broth microdilution method using antibiotic medium 3 improved the discrimination of in vitro susceptibility against amphotericin B and demonstrated that var. gattii isolates were less susceptible (geometric means 0.25 microg/ml versus 0.64 microg/ml, P < 0.001). In addition, a higher proportion of var. gattii were less susceptible to flucytosine as compared with var. neoformans (35.0% versus 64.9%, P = 0.030). There was no seasonal clustering for isolation of var. neoformans, though infections caused by var. gattii peaked in July and August. Compared with the first study of cryptococcosis (1957-1972) at NTUH, this study demonstrated the increase in immunocompromised and elderly patients, as well as a higher proportion of Cryptococcus isolated from blood or bone marrow. Facing the increasing adaptive plantation of Eucalyptus in Taiwan, the importance of field study regarding the role of Eucalyptus plantations in Taiwan and occurrence of cryptococcosis in human beings cannot be over-emphasized.

AIDS-Related Opportunistic Infections↗
PubMed2000

Cryptococcal meningitis in non-HIV-infected patients.

There are few reports on cryptococcal meningitis in non-HIV-infected patients in subtropical areas. We reviewed 94 non-HIV-infected patients microbiologically diagnosed with cryptococcal meningitis and hospitalized at National Taiwan University Hospital, 1977-1996. Forty-two patients (44.7%) had underlying diseases. The main initial manifestations were headache (86.2%), vomiting (72.3%) and fever (69. 1%). The 30 patients with T-cell suppression had more acute illnesses (median duration of symptoms: 14 days vs. 29 days), less typical presentations of meningitis, and reduced inflammatory responses compared with the 64 without T cell suppression. There was no statistical difference between patients who received amphotericin B treatment for 10 weeks and those received amphotericin B with subsequent fluconazole treatment, in terms of mortality rate and recurrence rate. Seventy-five patients (79.8%) had satisfactory clinical responses, and two relapsed. Eighteen patients died (19.1%) and 10 of these died within 2 weeks of hospitalization. Patients in this series had outcomes comparable with those from temperate and even tropical countries with high percentages of immunocompetent hosts. Factors significantly associated with death were lymphoma, semicoma, leukocytosis, and initial high titres of cryptococcal antigen in cerebral spinal fluid (especially >/=1 : 512). On multivariate analysis, lymphoma and initial high cryptococcal antigen titres were independent predictors of mortality.

AIDS-Related Opportunistic Infections↗
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↗
PubMed1999

Antithyroid-drug-induced agranulocytosis complicated by life-threatening infections.

Agranulocytosis is a rare complication of antithyroid drugs, and the aetiologies of community-acquired, life-threatening infections in patients taking these drugs have not previously been systematically described. Of 5653 hyperthyroid patients treated with antithyroid drugs at National Taiwan University Hospital between January 1987 and December 1997, 13 (0.23%) developed agranulocytosis with life-threatening infections. The most common presentations were fever (92%) and sore throat (85%). Initial clinical diagnoses were acute pharyngitis (46%), acute tonsillitis (38%), pneumonia (15%) and urinary tract infection (8%). Positive blood cultures from six patients yielded Pseudomonas aeruginosa (3), Escherichia coli (1), Staphylococcus aureus (1), Capnocytophaga species (1). Two patients died of uncontrolled infection, thyroid storm and multiple organ failure. Cases of antithyroid-drug-induced agranulocytosis in the English language literature are reviewed; Gram-negative bacilli, including Klebsiella pneumoniae (4 patients) and P. aeruginosa (3), were the most common pathogens in clinical isolates. Our observation and review suggest that broad-spectrum antibiotics with anti-pseudomonal activity should be given to patients with antithyroid drug-induced agranulocytosis who present with severe infection.

Adolescent↗
PubMed1999

Imported malaria: successful treatment of 31 patients in the era of chloroquine resistance.

The diagnosis and management of imported malaria presents a continuing challenge in developed countries, including Taiwan. We retrospectively analyzed the records of all 31 patients with imported malaria treated at National Taiwan University Hospital from January 1984 through December 1998. Plasmodium falciparum was identified as the causative malarial parasite in 18 patients, P. vivax in 12, and P. ovale in one. All 31 patients had fever, but only 13 presented with the characteristic fever pattern. The most common initial laboratory abnormalities were thrombocytopenia (20/31), mild hyperbilirubinemia (20/31), and leukopenia (7/31). The median time from the onset of fever to the correct diagnosis was 4 days for P. falciparum and 5 days for P. vivax. In 28 cases, the clue that led to early diagnosis was the patient's travel history. Quinine, but not chloroquine, was effective in 17 out of 18 cases of falciparum malaria. Three patients treated with intravenous quinine required a change of regimen because of life-threatening quinine toxicity; artesunate served as a safe and effective alternative in this situation. While most patients with tertian malaria were cured with the standard chloroquine and primaquine regimen, a higher dosage was required for one case acquired in Papua New Guinea. All patients, including two with severe malaria, survived. We conclude that, the mortality of imported malaria in the chloroquine resistance era can be minimized with early recognition by obtaining a thorough travel history, and instituting appropriate antimalarial chemotherapy based on precise identification of species. Quinine toxicity should be closely monitoried, especially when this drug is given intravenously.

Adolescent↗
PubMed1998

In vitro activity of meropenem against common pathogenic bacteria isolated in Taiwan.

The in vitro antimicrobial activity of meropenem, in comparison with nine other antimicrobial agents, against 12 different common pathogenic bacteria were evaluated to know the susceptibility of common bacteria to meropenem in Taiwan. Meropenem was active against most Gram-positive, Gram-negative, and anaerobic bacteria, including methicillin-sensitive Staphylococcus aureus, Streptococcus pyogenes, Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Pseudomonas aeruginosa, Burkholderia cepacia, Acinetobacter baumannii, Haemophilus influenzae, and Bacteroides fragilis. For many of them, meropenem was the most active one in comparison with other broad-spectrum cephalosporins, aztreonam, imipenem, and ciprofloxacin. It is concluded that meropenem is a very active agent against most common pathogenic bacteria. It is uncommon for these common bacteria, except MRSA and Stenotrophomonas maltophilia, to be resistant to meropenem in Taiwan, where a high prevalence of resistance to other antimicrobial agents was found in many of the common bacteria.

Anti-Bacterial Agents↗
PubMed1998

Effect of UV exposure and beta-carotene supplementation on delayed-type hypersensitivity response in healthy older men.

OBJECTIVES: The aims of this study were to determine if ultraviolet light (UV) is immunosuppressive in healthy older males, if beta-carotene (betaC) supplementation could prevent any observed UV-induced immunosuppression, and to compare these effects with those observed previously in younger men. METHODS: The study was a placebo-controlled, randomized trial that employed a 2 x 2 factorial design. Healthy older men (mean age 65.5 years) received 30 mg betaC or placebo daily throughout the 47-day trial, while on a low carotenoid diet. After 28 days, half of each group received 12 suberythemic exposures to UV over a 16-day period. Delayed-type hypersensitivity (DTH) tests and plasma carotenoid assays were performed at baseline, pre-UV and post-UV time points, with DTH testing performed on an area of skin protected from UV exposure. RESULTS: UV exposure resulted in significantly suppressed DTH response in the placebo group but not in the betaC-UV group. While there was no significant interaction between betaC supplementation and UV on DTH response, there was a significant inverse relationship between final plasma betaC concentration and extent of UV-induced suppression of DTH response. A similar correlation existed among subjects not exposed to UV. CONCLUSIONS: Suberythemic UV exposure was immunosuppressive, as measured by DTH response, in healthy older men as in younger men. Higher plasma betaC was significantly associated with maintenance of DTH response, although the extent of protective effect of betaC appeared less than previously observed in younger subjects. The attenuated effect of betaC in the older UV-exposed subjects may have resulted in part from muted plasma betaC responses to betaC supplementation and/or higher plasma vitamin E levels than those of younger men. The finding that stronger DTH responses were associated with higher plasma betaC concentrations in both UV and non-UV subjects further supports a role for this nutrient in immunomodulation.

Adult↗
PubMed1998

Tuberculous peritonitis: analysis of 35 cases.

Thirty five patients with tuberculous peritonitis were studied retrospectively. Tuberculous peritonitis was defined as the isolation of Mycobacterium tuberculosis from ascites or dialysate, and/or caseating granuloma/acid-fast bacilli from peritoneal biopsy specimens from patients with pulmonary tuberculosis or a response to treatment for tuberculosis. Among the patients studied, nine with cirrhosis of the liver; seven with diabetes mellitus and six with end-stage renal disease, of whom four had undergone continuous ambulatory peritoneal dialysis. The most frequent signs of tuberculous peritonitis included ascites, fever and anemia. Ascites was found in 31 patients (89%). Abnormal findings on chest radiographs were found in 26 patients (74%), of whom 22 patients (63%) had pleural effusion and five had miliary lung lesions. Seven out of 35 patients were found to have positive culture of sputum or pleural effusion for M. tuberculosis. Two patients were found to have concomitant tuberculous peritonitis and enteritis. Multiple organ involvement was found in eight patients. Eleven patients (31%) died: eight were older than 60 years; six had cirrhosis of the liver and nine were diagnosed post-mortemly. In Taiwan, tuberculous peritonitis should be considered in patients with abnormality of chest radiography and nonresolving peritonitis.

Adolescent↗
PubMed1998

Review of the medical management of postoperative cataract complications.

BACKGROUND: With the increasing number of surgeons using phacoemulsification techniques combined with sutureless scleral tunnel and clear corneal incisions for cataract surgery, the majority of patients will undergo an uncomplicated course of visual rehabilitation requiring no more than standard topical antibiotic and steroid regimen. Occasionally--even with an uneventful surgical course--postoperative complications arise. Many of these postoperative complications can be managed medically, without surgical intervention. Topical and oral glaucoma and nonsteroidal anti-inflammatory agents play an important role in the management of postoperative cataract complications. METHODS: A review of the common postoperative complications and their medical management using topical and oral pharmaceutical agents are presented. Emphasis is placed on current trends in treatment following contemporary cataract surgery. CONCLUSION: Although the complication rate is reduced with modern cataract surgery techniques, the primary care clinician should be prepared to identify and manage the most common clinical conditions. Armed with the proper knowledge of ophthalmic medications and their possible ocular and systemic interactions, optometrists can successfully manage and co-manage many postoperative cataract complications. Common postoperative complications are reviewed, along with current treatment regiments and dosage forms.

Cataract Extraction↗
PubMed1998

Randomized, double-blind, placebo-controlled study of transdermal nicotine patch for smoking cessation.

Smoking cessation is an arduous process because nicotine withdrawal syndrome, which occurs following sudden interruption of nicotine use in long-term smokers, frequently prevents them from giving up the habit. Nicotine supplement systems may relieve smokers' nicotine withdrawal symptoms and, thus, help in the process of abstinence from smoking. The purpose of the present study was to investigate the effectiveness and safety of a 30-mg transdermal nicotine patch in a smoking cessation program for Chinese smokers. In this randomized, double-blind, placebo-controlled study, 30 heavy smokers, who had smoked more than 20 cigarettes per day for more than a year, were treated with 30-mg transdermal nicotine patches, and 32 heavy smokers were given placebo patches during a 6-week smoking cessation program. The clinical characteristics of the two groups were similar. After 6 weeks, the use of the transdermal nicotine patch was associated with markedly reduced nicotine dependence and severity of withdrawal symptoms. Nineteen (63%, 95% confidence interval, CI, 46%-80%) of the smokers treated with the transdermal nicotine patch had successfully quit smoking at the end of the program (6 weeks) and nine (30%, 95% CI 14%-46%) remained abstinent 1 year later. In contrast, only 11 (34%, 95% CI 18%-50%) of the smokers in the placebo group had successfully stopped smoking after 6 weeks, and three remained abstinent 1 year later (9%, 95% CI 0%-19%). However, there was no statistically significant difference between the two groups of smokers after 1 year of follow-up (p = 0.08). Side-effects were minimal and did not affect the efficacy of the skin patch. The results indicate that the transdermal nicotine patch is an effective aid in smoking cessation programs.

Administration, Cutaneous↗
PubMed1997

Increasing incidence of nosocomial Chryseobacterium indologenes infections in Taiwan.

To understand the clinical features, antimicrobial therapy, and epidemiology of Chryseobacterium indologenes infections, the medical records of 36 patients with nosocomial Chryseobacterium indologenes infections seen over a three-year period at National Taiwan University Hospital were reviewed. The 36 isolates recovered from these patients were studied by molecular typing and determination of antimicrobial susceptibility patterns. Nine patients had underlying neoplastic diseases, seven had diabetes mellitus, five had burn wounds, and four had uremia. The clinical syndrome included ten patients with intraabdominal infections, nine with wound sepsis, six with intravascular catheter-related bacteremia, and four with ventilator-associated pneumonia. Thirteen patients had monomicrobial bacteremia, and four had polymicrobial bacteremia. Nineteen patients (53%) developed infections associated with various indwelling devices. The deaths of five patients (14%) were directly attributable to infection with Chryseobacterium indologenes. All isolates recovered showed a wide range of resistance to commonly used antimicrobial agents. The random amplified polymorphic DNA (RAPD) patterns of the isolates differed from each other, indicating the absence of epidemiological relatedness among these isolates. Nosocomial infection caused by multiresistant Chryseobacterium indologenes appears to be an emerging problem in Taiwan and should be studied further.

Adolescent↗