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Biomedical subjects

S C Chang

Publications and source records attributed to S C Chang.

At least 19 recordsLinked to original sources

Skin and soft tissue infection caused by non-tuberculous mycobacteria.

SETTING: A medical centre in Taipei, Taiwan. OBJECTIVE: To investigate the trend and characteristics of patients with non-tuberculous mycobacteria (NTM) related skin and soft tissue infection. DESIGN: A total of 63 patients with culture-proven diseases were identified from January 1997 to December 2004. The medical records of all patients were reviewed. RESULTS: Twenty-seven patients were infected with rapidly growing mycobacteria (RGM), 19 with Mycobacterium marinum, six with M. avium complex (MAC), five with M. kansasii and six with other species. Most patients presented with a protracted cutaneous lesion without systemic symptoms, and two thirds of the patients had a history of exposure. Seventy-three per cent of the lesions involved the extremities. Underlying illness with suppressed immunity was documented in 30.2% of the patients, and was most prevalent in patients with MAC (100%) and M. kansasii (60%). Of the patients, 62% underwent at least one surgical intervention, and 77.8% received treatment with different antimicrobial combinations. Most patients (86%) recovered completely. Granulomatous inflammation was found in 88.9% of biopsied tissue associated with M. marinum infection, 31.8% with RGM and 25.0% with MAC. CONCLUSION: A combination of surgery and antimicrobials cured most patients with microbiologically proven localised NTM skin and soft tissue infection.

Adolescent↗

Two novel mutations in the MEN1 gene in subjects with multiple endocrine neoplasia-1.

Multiple endocrine neoplasia type 1 (MEN1) is characterized by parathyroid, enteropancreatic endocrine and pituitary adenomas as well as germline mutation of the MEN1 gene. We describe 2 families with MEN1 with novel mutations in the MEN1 gene. One family was of Turkish origin, and the index patient had primary hyperparathyroidism (PHPT) plus a prolactinoma; three relatives had PHPT only. The index patient in the second family was a 46-yr-old woman of Chinese origin living in Taiwan. This patient presented with a complaint of epigastric pain and watery diarrhea over the past 3 months, and had undergone subtotal parathyroidectomy and enucleation of pancreatic islet cell tumor about 10 yr before. There was also a prolactinoma. Sequence analysis of the MEN1 gene from leukocyte genomic DNA revealed heterozygous mutations in both probands. The Turkish patient and her affected relatives all had a heterozygous A to G transition at codon 557 (AAG-->GAG) of exon 10 of MEN1 that results in a replacement of lysine by glutamic acid. The Chinese index patient and one of her siblings had a heterozygous mutation at codon 418 of exon 9 (GAC-->TAT) that results in a substitution of aspartic acid by tyrosine. In conclusion, we have identified 2 novel missense mutations in the MEN1 gene.

Adenoma↗

Sparing immunosuppression in heart transplant recipients with severe sepsis.

This study described an analysis of severe sepsis among heart transplantation recipients who were treated by sparing all immunosuppressants. Sepsis leading to multiple organ failure (MOF) in heart transplantation has a high mortality. This retrospective study of 190 patients who underwent heart transplantation from 1993 to 2004 included 12 who had severe sepsis with MOF who were treated by sparing all immunosuppressants. Half of them survived after sparing all immunosuppressants with intensive endomyocardial biopsy. Only one case needed pulse therapy for an acute rejection episode. The most common bacterial infectious episodes were caused by methicillin-resistant Staphylococcus aureus (n = 3). All sepsis episodes occurred in the first month after heart transplantation except in one case, which occurred 6 years after heart transplantation. There was a 50% survival rate of heart transplantation recipients who experienced MOF due to severe sepsis and were treated by sparing all immunosuppressants under a program of intensive endomyocardial biopsy.

Bacterial Infections↗

Effects of internal medicine residency training in AIDS care in Taiwan.

Having contact and interacting with HIV/AIDS patients has long been recognized as a means for improving AIDS-related knowledge and attitudes among physicians and hence for increasing their intention to provide AIDS care. To investigate the impact of one-month residency training in an AIDS inpatient unit on internal medicine residents, this quasi-experimental, pre-post, two-group study, conducted from April 2000 to April 2001, used questionnaires. At follow-up, residents who received training in the AIDS unit (experimental group) were significantly more knowledgeable about HIV/AIDS, had more positive attitudes and greater intention to care for HIV-infected patients than residents who did not receive this training (control group). Results suggest that a one-month AIDS residency training intervention can effectively enhance residents' HIV-related knowledge, attitudes and intention to care for patients infected with HIV.

Adult↗

Comparative impact of hospital-acquired infections on medical costs, length of hospital stay and outcome between community hospitals and medical centres.

To understand the impact of hospital-acquired infections on mortality and medical costs in modern medical care systems in different healthcare settings, we performed a case-control study at a medical centre and two community hospitals. A total of 144 and 129 adult case-control pairs who received care in a 2000-bed tertiary referral medical centre and two 800-bed community hospitals, respectively, between October 2002 and December 2002 were enrolled. Prolongation of hospital stay, extra costs and complications associated with hospital-acquired infections were analysed. Patients in the medical centre had more severe underlying disease status (P < 0.001), more malignancies (P < 0.001), more multiple episodes of hospital-acquired infection (p = 0.03), and more infections with multidrug-resistant bacteria (P < 0.001) than patients in community hospitals. The additional length of hospital stay and extra costs were similar for patients with hospital-acquired infections in the community hospitals and the medical centre (mean 19.2 days vs. 20.1 days, P = 0.79; mean 5335 US dollars vs. 5058 US dollars, P = 0.83; respectively). The additional length of hospital stay and extra costs in both the medical centre and the community hospitals were not related to the sites of infection or the bacterial pathogens causing hospital-acquired infections, although medical costs attributable to hospital-acquired fungal infections due to Candida spp. were much higher for patients in the medical centre. Prevalence of hospital-acquired-infection-related complications, such as adult respiratory distress syndrome, disseminated intravascular coagulation, organ failure or shock, was similar between the two groups, but patients in the medical centre had a higher mortality rate because of their underlying co-morbidities.

Adolescent↗

Impact of chronic hepatitis C infection on outcomes of patients with an advanced stage of HIV-1 infection in an area of low prevalence of co-infection.

To ascertain whether hepatitis C (HCV) co-infection affects the progression of HIV infection, we initiated an eight-year prospective observational study at a university hospital in Taiwan where seroprevalences of HCV antibody and HIV antibody were low. Fifty-three (12.0%) consecutive non-haemophiliac HIV1-infected patients with HCV co-infection and 387 (88.0%) patients without HCV and hepatitis B co-infection were enrolled between June 1994 and June 2002 and observed until December 2002. Outcomes evaluated included the risk for acute hepatitis, hepatic decompensation, HIV disease progression and mortality, and changes of CD4+ count and plasma viral load (PVL) after initiation of highly active antiretroviral therapy (HAART) at the end of the study. The baseline CD4+ count, PVL and proportion of patients with AIDS-defining opportunistic illnesses (OI) at study entry were similar between patients with HCV co-infection and those without co-infection, but HCV-co-infected patients were older (39 versus 35 years, P = 0.01) and had a higher proportion of intravenous drug use (17.0% versus 0.8%, P < 0.001). After a total observation duration of 1137 patient-years (PY) (median, 791 days; range, 3-3053 days), the incidence of acute hepatitis in HCV-co-infected patients was 13.89 per 100 PY (95% confidence interval [CI], 13.31-14.49) and that in patients without co-infection was 6.39 per 100 PY (95% CI, 6.24-6.55 per 100 PY), with an adjusted odds ratio (OR) of 2.769 (95% CI, 1.652-4.640). At the end of the study, CD4+ count increased by 137 x 10(6) and 157 x 10(6)/L in patients with and without HCV co-infection, respectively, (P = 0.47). The proportions of achieving undetectable PVL (<400 copies/mL) after HAART was similar (76.7% versus 74.9%, P = 0.79). The adjusted OR for development of new AIDS-defining OI was 1.826 (95% CI, 0.738-4.522) in HCV-co-infected patients as compared with HCV- uninfected patients. The adjusted hazards ratio for death of HCV-co-infected patients when compared with those without co-infection was 0.781 (95% CI, 0.426-1.432). Our findings suggested that HCV co-infection was associated with a significantly higher risk for acute hepatitis in HIV-infected patients receiving antiretroviral therapy, but it had no adverse impact on virological, immunological and clinical responses to HAART and survival when compared with patients without HCV and HBV co-infection.

AIDS-Related Opportunistic Infections↗

Prevalence of Toxoplasma gondii infection and incidence of toxoplasma encephalitis in non-haemophiliac HIV-1-infected adults in Taiwan.

We assessed the seroprevalence of Toxoplasma gondii infection and incidence of toxoplasma encephalitis (TE) in 844 non-haemophiliac HIV-infected patients in Taiwan between June 1994 and April 2003. Approximately 70% (69.3%) of them had a baseline CD4+ lymphocyte count of 200 x 10(6)/L or less, and more than 70% (73.9%) having initiated highly active antiretroviral therapy. The seroprevalence of T. gondii infection was 10.2%, which did not differ with sex,age,route of transmission, birth inside or outside of Taiwan, or CD4+ lymphocyte stratifications. After a median observation duration of 603 days (range, 1-3264 days), 10 (1.2%) patients developed 11 episodes of TE after a median interval of 30 days (range, 1-941 days) between enrolment and diagnosis of TE, with an incidence of 0.59 per 100 person-years (PY) (95% confidence interval, 0.56-0.63 per 100 PY). We concluded that the incidence of TE of HIV-infected patients in Taiwan was lower than that reported in western countries because of a lower seroprevalence of T. gondii infection and use of antimicrobial prophylaxis and antiretroviral therapy, although most of the patients were at the late stage of HIV infection.

Adolescent↗

MHC class I chain-related gene A (MICA) polymorphism and the different histological types of cervical cancer.

Cervical cancer has been one of the most important gynecologic cancer in Taiwan with incidence of 24/100,000 and mortality of 8.7/100,000 annually. About 70-80% are squamous cell carcinoma; the remainder are composed of various types of adenocarcinoma, adenosquamous carcinoma and undifferentiated carcinoma. The Major Histocompatibility Complex (MHC) class I chain-related gene A (MICA) is expressed by keratinocytes and epithelial cells and interacts with gamma-delta T cells. Although MICA was not associated with cervical cancer in the study of Northern Sweden, there are no further studies about the association of MICA polymorphism and the different histological types of cervical cancer. We analyzed the MICA polymorphism in 110 cervical cancer cases (88 squamous cell carcinoma, 12 adenocarcinoma and 10 adenosquamous carcinoma) and 82 randomly selected unrelated controls from 1994 to 2000 in the Mackay Memorial Hospital, Taipei, Taiwan. DNA was extracted part from leukocytes of peripheral blood, part from tumor tissue and 5 polymorphic microsatellite alleles (A4,A5,A5.1,A6,A9) of MICA were identified by a polymerase chain reaction-based (PCR) technique using ABI Prism 377-18 DNA sequencer (Applied Biosystems, Foster City, CA, USA). The phenotypes, alleles and genotypes of MICA gene were calculated. There was no association with cervical cancer patients and non-cervical cancer patients (p=0.337, 0.356 and 0.414). After dividing the cervical cancer patients into 3 major histological types (squamous cell carcinoma, adenocarcinoma and adenosquamous carcinoma), the result was still the same (p=0.598, 0.172 and 0.617) in our study. We found no association between MICA gene polymorphism and cervical cancer in Taiwan. Different histological types of cervical cancer also have no significant correlation with MICA gene polymorphism. It demonstrates that polymorphism of MICA gene bears no relation to cervical cancer and the different histological types of cervical cancer in Taiwan. We need further studies for identifying the factors causing the differentiation of cancer cells of the uterine cervix.

Adenocarcinoma↗

Fatal lactic acidosis associated with highly active antiretroviral therapy in patients with advanced human immunodeficiency virus infection in Taiwan.

Lactic acidosis (LA), a rare but life-threatening adverse effect associated with antiretroviral therapy, has been reported with an increasing frequency since the mid-1990s. From June 1994 to June 2002, a total of six patients, four males and two females with a median age of 43 years (range, 30 to 74 years), had been diagnosed with LA. The estimated incidence of LA was 5.1 per 1000 patient-years (PYs) on highly active antiretroviral therapy (HAART) (95% confidence interval [95% CI], 4.5-5.5 per 1000 PYs) and 4.4 per 1000 PY on nucleoside analogues (NAs) (95% CI, 3.9-4.7 per 1000 PYs). Their median body mass index at diagnosis of LA was 17.6 kg/m(2) (range 16.3 to 22.6 kg/m(2)). The median CD4+ lymphocyte count at the initial diagnosis of HIV infection and at the onset of LA was 38 cells/ micro L (range, 4 to 103 cells/ micro L) and 108 cells/ micro L (range, 79 to 224 cells/ micro L), respectively. The most common symptoms were nausea, vomiting, and dyspnoea. All of the patients had findings suggestive of NA-related mitochondrial toxicity, such as myositis, pancreatitis, fatty hepatitis, peripheral neuropathy or lipodystrophy. The prescribed NA related to LA were stavudine in six patients, lamivudine, five, and didanosine, one. Despite treatment, all patients died of persistent circulatory collapse following LA. The median duration from diagnosis to death was eight days (range, 4-17 days). Our report highlights that clinicians caring for patients with AIDS should be alerted to the potentially fatal LA associated with antiretroviral therapy when patients present with low body mass index, lipodystrophy, unexplained abdominal symptoms, dyspnoea, or elevated aminotransferases.

Acid-Base Imbalance↗

Healthcare-associated outbreak due to pan-drug resistant Acinetobacter baumannii in a surgical intensive care unit.

Acinetobacter baumannii is ubiquitous and has recently become one of the most important healthcare-associated (HA) pathogens in hospitals. Infection caused by this organism often leads to significant morbidity and mortality. Outbreaks of pan-drug resistant Acinetobacter baumannii (PDRAB) have rarely been reported. During a two-month period, an outbreak of PDRAB colonization and infection affecting 7 patients occurred in our surgical intensive care unit (SICU). The colonized sites were respiratory tract (N = 7) and central venous catheter (N = 2). One of the patients had a surgical wound infection. Extensive environmental contamination was identified, including sites such as bed rails, bedside tables, surface of ventilators and infusion pump, water for nasogastric feeding and ventilator rinsing and sinks. All of the isolates were analysed by pulsed-field gel electrophoresis (PFGE) and showed an identical pattern. After use of strict cohort nursing, hand hygiene environmental cleaning, and replacement of a dysfunctional high-efficiency particulate air filter (HEPA), the outbreak was controlled.

Acinetobacter Infections↗

Administration of triiodothyronine and dopamine to broiler chicks increases growth, feed conversion and visceral organ mass.

The influences of triiodothyronine (T3) or dopamine (DA) administration on growth, feed conversion, and visceral weights in broiler chicks between the ages of 6 and 12 d posthatch were investigated. In Trial 1, six chicks at age 6 d were randomly administered one of the following treatments: 0.37, 0.74, 1.48, and 2.96 micromol T3/kg BW or 0.07, 0.14, 0.28, and 0.56 micromol DA/kg BW. Both T3 and DA were administered via intraperitoneal injections between the end of sternum and the ends of os pubis, with 0.9% saline as the excepient. In addition, two groups of six birds each were either not injected or injected with excepient only, as controls. Four replications were carried out with a total of 264 chicks. Heart weight as a percentage of feed-deprived body weight (FDBW) of the chicks injected with 2.96 micromol T3/kg BW was heavier than that of controls. Other variables measured were not significantly different between treatments. In trial 2, six chicks at age 6 d were randomly administered, one of the following treatments: 0.56, 1.12, 2.24, and 4.48 micromol T3/kg diet or 0.40, 0.80, 1.60, and 3.20 micromol DA/kg diet as well as a nonsupplemented control. Four replications were carried out with 216 chicks. The results in Trial 2 showed that the effects of T3 (X, micromol/kg diet) on body weight gain (Y1, g) and feed consumption (Y2, g) were linear (Y1 = 310 - 21.5X, R2 = 0.868, P < 0.001 and Y2 = 398 - 22.3X, R2 = 0.765, P < 0.001, respectively). The feed conversion ratio, the weight of liver, the weights of various intestinal segments, the lengths of the duodenum, jejunum and the ileum, as well as weight per centimeter jejunal length, gizzard weight as percentage of FDBW, and the duodenal length per kilogram FDBW all had linear responses (P < 0.05) to the level of dietary supplementation of T3. The effect of dietary supplementation of T3 on the heart weight was quadratic (Y16 = 2.58 + 0.89X - 0.17 X2, R2 = 0.526, P < 0.01). Similarly, the weights of pancreas and gizzard, the heart weight as a percentage of FDBW and the pancreas weight as a percentage of FDBW all had second-order curve responses. Dietary DA supplementation exerted no effect on the variables measured except that the regression of the heart weight as a percentage of FDBW on dietary DA supplementation (X1, micromol/kg diet) existed, namely, Z1 = 0.64 + 0.24 X1 - 0.23 X1(2) + 0.05 X1(3) (R2 = 0.868, P < 0.05).

Animal Nutritional Physiological Phenomena↗

Asthma management efficacy of school nurses in Taiwan.

As the key health care providers in school settings, the school nurses' asthma management efficacy is crucial to children's health and their continued participation in school learning activities. This article describes the psychometric testing of the asthma management efficacy scale (AMES) for use with school nurses. A cross-sectional survey design was used to assess the asthma management efficacy of 60 school nurses in Taipei, Taiwan. Factor analysis resulted in four factor domains including asthma medication administration, asthma pattern identification, school management behaviour, and monitoring peak expiratory flow rate which explained 76.4% of the variance in school nurses' asthma management efficacy. The school nurses' experience in performing school asthma management activities was positively correlated to their asthma management efficacy (r=0.33, p<0.05). School nurses who had experience with the inhaled asthma medicines had significantly higher efficacy scores on the medication administration subscale (t=-2.89, p<0.01) than did the school nurses who lacked this experience. School nurses who had experience in using peak expiratory flow meters had significantly higher efficacy scores on the total AMES (t=-1.90, p<0.05) and on the monitoring peak expiratory flow rate subscale (t=-5.37, p<0.001) than the school nurses who lacked this experience. Given the need to have nurses who are well prepared to provide asthma care in school settings, implications for nursing education, practice, and further research are discussed.

Adult↗

Successful discontinuation of fluconazole as secondary prophylaxis for cryptococcosis in AIDS patients responding to highly active antiretroviral therapy.

Seven AIDS patients with disseminated cryptococcosis who had had immune reconstitution following highly active antiretroviral therapy (HAART) had discontinued their secondary antifungal prophylaxis to prevent relapse of Cryptococcus neoformans infection. The median CD4+ count was 236 cells/ micro L (range, 117-404 cells/ micro L; mean, 247 cells/ micro L) and the plasma viral loads were undetectable in five patients at discontinuation of antifungal prophylaxis. No relapse of cryptococcosis was detected in these patients after a median observation duration of nine months (range, 5.5-4.1 months, mean, 14.6 months) following discontinuation. Our data and review of the literature suggest that discontinuation of fluconazole prophylaxis is safe in patients with reconstitution of immunity following#10; initiation of HAART.

AIDS-Related Opportunistic Infections↗

Kinetics of antigen-induced phenotypic and functional maturation of human monocyte-derived dendritic cells.

Dendritic cells (DCs), a critical component of innate immunity, are the most potent APCs. When DCs mature, they can elicit strong T cell responses. We studied the kinetics of Ag-induced phenotypic and functional maturation of human monocyte-derived DCs using an in vitro T cell-independent culture system. With this model, we herein show that an Ag that has recently or repetitively been exposed ("exposed Ag") rapidly induces a high level of maturation; however, an Ag that has never or only remotely been exposed ("unexposed Ag") slowly induces a low level of maturation. The kinetics of Ag-induced maturation of DCs possibly implies a novel mechanism for immunological memory that would provide maximal host protection from repetitively invading pathogens in the environment.

Antigens, CD↗

Complex-temperature phase diagrams for the q-state Potts model on self-dual families of graphs and the nature of the q-->infinity limit.

Exact calculations of the Potts model partition function Z(G,q,v) have been presented for arbitrary q and temperature-like variable v on self-dual strip graphs G of the square lattice with fixed width L(y) and arbitrarily great length Lx with two types of boundary conditions. Letting Lx-->infinity, the resultant free energy and complex-temperature phase diagram have been computed, including the locus B where the free energy is nonanalytic. Results are analyzed for widths L(y)=1,2,3. These results have been used to study the approach to the large-q limit of B.

Journal Article↗