Assessment of latent tuberculosis infection in psychiatric inpatients: A survey after tuberculosis outbreaks

AbstractBackground/PurposeTo investigate risk factors of latent tuberculosis infection (LTBI) among inpatients of chronic psychiatric wards with tuberculosis (TB) outbreaks.MethodsIn April 2013, inpatients of four all-male wards with TB outbreaks were tested for LTBI using the QuantiFERON-TB Gold in Tube (QFT) method. Based on this investigation, a retrospective study was conducted to assess risk factors for LTBI. Inpatients exposed to cluster-A or cluster-B TB cases were defined as contacts of cluster-A or cluster-B, and others, as nonclustered contacts.ResultsAmong 355 inpatients with TB exposure, 134 (38%) were QFT-positive for LTBI. Univariate analysis showed that significant predictors for QFT-positivity were age, case-days of exposure to all TB cases (TB-all) and to sputum smear positive cases, number of source cases with cough, and exposure to cluster-A TB cases. Independent risk factors for LTBI were higher age [adjusted odds ratio (OR) 1.03, 95% confidence intervals (CI: 1.01–1.05)], TB-all exposure case-days ≥ 200 [adjusted OR 2.04 (1.06–3.92)] and exposure to cluster-A TB cases [adjusted OR 2.82 (1.30–6.12)] after adjustment for the sputum smear positivity, and cough variables of the source cases. The contacts of cluster-A had a greater risk of LTBI than did those of cluster-B, especially in the younger population (≤50 years) after adjustment [adjusted OR 2.64 (1.03–6.76)].ConclusionAfter TB outbreaks, more than one third of inpatients were QFT-positive for LTBI. Our findings suggest that, beside the infectiousness of source cases, intensity of exposure, and age of contacts, exposure to TB cases in potential genotyping clusters may be predictive for LTBI in this male psychiatric population

Increases in the proton conductivity and selectivity of proton exchange membranes for direct methanol fuel cells by formation of nanocomposites having proton conducting channels

Peer reviewed: YesNRC publication: Ye

Using silica nanoparticles for modifying sulfonated poly(phthalazinone ether ketone) membrane for direct methanol fuel cell : A significant improvement on cell performance

Sulfonated poly(phthalazinone ether ketone) (sPPEK) with a degree of sulfonation of 1.23 was mixed with silica nanoparticles to form hybrid materials for using as proton exchange membranes. The nanoparticles were found homogeneously dispersed in the polymer matrix and a high 30 phr (parts per hundred resin) loading of silica nanoparticles can be achieved. The hybrid membranes exhibited improved swelling behavior, thermal stability, and mechanical properties. The methanol crossover behavior of the membrane was also depressed such that these membranes are suitable for a high methanol concentration in feed (3 M) in cell test. The membrane with 5 phr silica nanoparticles showed an open cell potential of 0.6V and an optimum power density of 52.9mWcm 122 at a current density of 264.6mAcm 122, which is better than the performance of the pristine sPPEK membrane and Nafion\uae 117.NRC publication: Ye

Initial Presentations Predict Mortality in Pulmonary Tuberculosis Patients - A Prospective Observational Study

Despite effective anti-TB treatments, tuberculosis remains a serious threat to public health and is associated with high mortality. Old age and multiple co-morbidities are known risk factors for death. The association of clinical presentations with mortality in pulmonary tuberculosis patients remains an issue of controversy.This prospective observational study enrolled newly diagnosed, culture-proven pulmonary tuberculosis patients from five medical centers and one regional hospital, which were referral hospitals of TB patients. Radiographic findings and clinical symptoms were determined at the time of diagnosis. Patients who died for any reason during the course of anti-TB treatment were defined as mortality cases and death that occurred within 30 days of initiating treatment was defined as early mortality. Clinical factors associated with overall mortality and early mortality were investigated.A total of 992 patients were enrolled and 195 (19.7%) died. Nearly one-third (62/195, 31.8%) of the deaths occurred before or within 30 days of treatment initiation. Older age (RR = 1.04, 95%CI: 1.03–1.05), malignancy (RR = 2.42, 95%CI: 1.77–3.31), renal insufficiency (RR = 1.77, 95%CI: 1.12–2.80), presence of chronic cough (RR = 0.63, 95%CI: 0.47–0.84), fever (RR = 1.45, 95%CI: 1.09–1.94), and anorexia (RR = 1.49, 95%CI: 1.07–2.06) were independently associated with overall mortality. Kaplan-Meier survival analysis demonstrated significantly higher mortality in patients present with fever (p<0.001), anorexia (p = 0.005), and without chronic cough (p<0.001). Among patients of mortality, those with respiratory symptoms of chronic cough (RR = 0.56, 95%CI: 0.33–0.98) and dyspnea (HR = 0.51, 95%CI: 0.27–0.98) were less likely to experience early mortality. The radiological features were comparable between survivors and non-survivors.In addition to demographic characteristics, clinical presentations including the presence of fever, anorexia, and the absence of chronic cough, were also independent predictors for on-treatment mortality in pulmonary tuberculosis patients

Characteristics of pncA mutations in multidrug-resistant tuberculosis in Taiwan

<p>Abstract</p> <p>Background</p> <p>Pyrazinamide (PZA) is an important first-line drug in multidrug-resistant tuberculosis (MDRTB) treatment. However, the unreliable results obtained from traditional susceptibility testing limits its usefulness in clinical settings. The detection of <it>pncA </it>gene mutations is a potential surrogate of PZA susceptibility testing, especially in MDRTB isolates. The impact of genotypes of <it>M. tuberculosis </it>in <it>pncA </it>gene mutations also remains to be clarified.</p> <p>Methods</p> <p>MDRTB isolates were collected from six hospitals in Taiwan from January 2007 to December 2009. <it>pncA </it>gene sequencing, pyrazinamidase activity testing, and spoligotyping were performed on all of the isolates. PZA susceptibility was determined by the BACTEC MGIT 960 PZA method. The sensitivity and specificity of <it>pncA </it>gene analysis were estimated based on the results of PZA susceptibility testing.</p> <p>Results</p> <p>A total of 66 MDRTB isolates, including 37 Beijing and 29 non-Beijing strains, were included for analysis. Among these isolates, 36 (54.5%) were PZA-resistant and 30 (45.5%) were PZA-susceptible. The PZA-resistant isolates were more likely to have concomitant resistance to ethambutol and streptomycin. Thirty-seven mutation types out of 30 isolates were identified in the <it>pncA </it>gene, and most of them were point mutations. The sensitivities of <it>pncA </it>gene sequencing for PZA susceptibility in overall isolates, Beijing and non-Beijing strains were 80.6%, 76.2%, and 86.7% respectively, and the specificities were 96.7%, 93.8%, and 100% respectively.</p> <p>Conclusions</p> <p>More than half of the MDRTB isolates in this study are PZA-resistant. Analysis of <it>pncA </it>gene mutations helped to identify PZA-susceptible MDRTB isolates, especially in non-Beijing strains.</p

Evaluation of Magnetic Nanoparticle-Labeled Chondrocytes Cultivated on a Type II Collagen–Chitosan/Poly(Lactic-co-Glycolic) Acid Biphasic Scaffold

Chondral or osteochondral defects are still controversial problems in orthopedics. Here, chondrocytes labeled with magnetic nanoparticles were cultivated on a biphasic, type II collagen–chitosan/poly(lactic-co-glycolic acid) scaffold in an attempt to develop cultures with trackable cells exhibiting growth, differentiation, and regeneration. Rabbit chondrocytes were labeled with magnetic nanoparticles and characterized by scanning electron microscopy (SEM), transmission electron (TEM) microscopy, and gene and protein expression analyses. The experimental results showed that the magnetic nanoparticles did not affect the phenotype of chondrocytes after cell labeling, nor were protein and gene expression affected. The biphasic type II collagen–chitosan/poly(lactic-co-glycolic) acid scaffold was characterized by SEM, and labeled chondrocytes showed a homogeneous distribution throughout the scaffold after cultivation onto the polymer. Cellular phenotype remained unaltered but with increased gene expression of type II collagen and aggrecan, as indicated by cell staining, indicating chondrogenesis. Decreased SRY-related high mobility group-box gene (Sox-9) levels of cultured chondrocytes indicated that differentiation was associated with osteogenesis. These results are encouraging for the development of techniques for trackable cartilage regeneration and osteochondral defect repair which may be applied in vivo and, eventually, in clinical trials

Increasing Drug Resistance of Mycobacterium tuberculosis Isolates in a Medical Center in Northern Taiwan

This retrospective study was conducted to evaluate the drug resistance patterns of Mycobacterium tuberculosis in a medical center in northern Taiwan between 2003 and 2004 in comparison to those reported in 1990-1992. Methods: A total of 611 non-duplicate M. tuberculosis isolates from culture-proven tuberculosis (TB) cases were tested for drug susceptibility against five first-line anti-TB drugs in a clinical mycobacterial laboratory using the agar proportional method for isoniazid (INH), rifampicin (RIF), ethambutol (EMB), and streptomycin (SM). The Wayne assay, which measures the activity of pyrazinamide (PZA), was used for PZA susceptibility testing. Results: Of 611 patients, including 510 males and 101 females, 70.2% of patients were older than 65 years. A total of 339 isolates (55.5%) were resistant to one or more drugs. Isolates from patients aged < 25 years showed a significantly higher drug resistance rate (79.2%) compared with other age groups (p = 0.0312). Single-drug resistance was observed in 97 (15.9%) of all isolates. Monoresistance to PZA (8.0%) was most frequent, followed by INH (5.1%), RIF (0.5%), EMB (1.6%), and SM (0.7%). Among the polydrug resistant isolates (PDR-TB), resistance rates were 35.5% for INH and 27.0% for RIF. One hundred and fifty-nine isolates (26.0%) were resistant to both INH and RIF (multidrug-resistant [MDR] TB); 94.6% of RIF-resistant isolates were also resistant to INH. The overall drug resistance rates and percentages of PDR-TB and MDR-TB increased over the 12-year study period (p < 0.001). Based on medical records, primary cases were identified in 486 (84.7%) out of 574 patients, and resistance to any drug was identified in 268 (55.1%) patients, of which 130 (26.7%) were MDR-TB. Among the 88 with recurrent TB, 54 (61.4%) were resistant to at least one drug, and MDR-TB was identified in 29 (33.0%) patients. A history of previous anti-TB therapy was a significant factor for overall drug resistance, PZA monoresistance, PDR-TB, and MDR-TB (p < 0.001). Conclusion: The emergence of M. tuberculosis isolates resistant to anti-TB agents in this hospital, and in particular among young patients, is alarming. Strict measures to control and prevent drug-resistant TB are urgently needed

Clinical Impact of Mycobacterium tuberculosis W-Beijing Genotype Strain Infection on Aged Patients in Taiwan▿

The impact of W-Beijing genotype Mycobacterium tuberculosis on treatment outcome was evaluated in 249 newly diagnosed tuberculosis patients. No significant difference in the treatment outcome was found between the W-Beijing and non-W-Beijing groups. However, a poor outcome was more common in the elderly patients (≥65 years) infected with the W-Beijing strain

Study of High Performance Sulfonated Polyether Ether Ketone Composite Electrolyte Membranes

In this study, high performance composite electrolyte membranes were prepared from polyether ether ketone polymeric material. An initial sulfonation reaction improved the membrane hydrophilicity and its water absorbability and thus enhanced the ionic conductivity in electrochemical cells. Protonic conductivity was improved from 10&minus;4 to 10&minus;2 S cm&minus;1 with an increasing sulfonation time from 72 to 175 h. The effects of blending nano SiO2 into the composite membranes were devoted to improve thermal and mechanical properties, as well as methanol permeability. Methanol permeability was reduced to 3.1 &times; 10&minus;7 cm2 s&minus;1. Finally, a further improvement in ionic conductivity was carried out by a supercritical carbon dioxide treatment under 20 MPa at 40&deg;C for 30 min with an optimum SiO2 blend ratio of 10 wt-%. The plasticizing effect by the Lewis acid-base interaction between CO2 and electron donor species on polymer chains decreased the glass transition and melting temperatures. The results show that sulfonated composite membranes blended with SiO2 and using a supercritical carbon dioxide treatment exhibit a lower glass transition temperature, higher ionic conductivity, lower methanol permeability, good thermal stability, and strong mechanical properties. Ionic conductivity was improved to 1.55 &times; 10&minus;2 S cm&minus;1. The ion exchange capacity and the degree of sulfonation were also investigated