Evaluation of the performance of the microscopic observation drug susceptibility assay for diagnosis of extrapulmonary tuberculosis in China: A preliminary study.

BACKGROUND AND OBJECTIVE: While commercial liquid culture techniques have emerged over 20 years ago, Ziehl-Neelsen (ZN) smear microscopy remains the primary method for diagnosis of tuberculosis (TB) in China because of cost considerations. The microscopic observation drug susceptibility (MODS) assay has been evaluated in different parts of the world to determine whether it can give comparable result to commercial liquid techniques. However, most reports detail evaluation of sputum specimens. This study evaluated the performance of MODS assay for detection of Mycobacterium tuberculosis in extrapulmonary specimens in a Chinese population. METHODS: A total of 173 samples, including pleural fluid (n = 112) and cerebrospinal fluid (CSF, n = 61) samples, were collected from patients suspected to have extrapulmonary TB and tested by ZN smear microscopy, Lowenstein-Jensen (LJ) culture and the MODS assay. Discordant results among MODS assay and the other two methods were resolved by 90-day follow-up evaluation for all suspected patients. RESULTS: The sensitivity of the MODS assay on pleural fluid and CSF samples was 20.5% and 37.5%, respectively, while the specificity of MODS assay on both types of samples approximated 100%. The median time to culture results for the MODS and LJ methods was 14 days, 32 days for pleural fluid, and 9 days and 31 days for CSF samples, respectively. CONCLUSIONS: MODS assay is useful to diagnose extrapulmonary TB and may be an effective and affordable method in resource-limited countries.

The adverse association of animal zinc intake with cardio-cerebrovascular and metabolic risk factors.

Background: The effect of zinc intake on cardio-cerebrovascular and metabolic diseases has always been controversial. Aims: We hoped to evaluate the associations of the daily dietary estimate (DDE) of zinc intake with cardio-cerebrovascular and metabolic risk factors. Methods: Baseline data from the Study of Women's Health Across the Nation (SWAN) were obtained. Multivariable linear regression analysis was used to examine associations of the DDE of zinc intake with cardio-cerebrovascular and metabolic risk factors. Results: The smooth curve demonstrated positive associations of the DDE of animal zinc intake with low-density lipoprotein-cholesterol (LDL-C), triglycerides, total cholesterol, fasting blood glucose, insulin, systolic blood pressure (BP) and diastolic BP and an inverse association of the DDE of animal zinc intake with high-density lipoprotein-cholesterol (HDL-C). Consistently, multivariable linear regression models also showed that an increased DDE of animal zinc intake was closely related to a higher risk of cardio-cerebrovascular and metabolic risk factors [systolic BP: 0.37 (0.13, 0.61); diastolic BP: 0.17 (0.02, 0.33); fasting blood glucose: 1.13 (0.67, 1.59); insulin: 0.26 (0.05, 0.47); LDL-C: 0.82 (0.34, 1.29), triglycerides: 1.65 (0.75, 2.55), total cholesterol: 0.91 (0.38, 1.43) and HDL-C: -0.24 (-0.45, -0.03)] when age, race/ethnicity, total family income, smoking status, alcohol consumption and menopausal status were controlled for. Importantly, stratified analysis supported that the independent associations between the DDE of animal zinc intake and risk factors for cardio-cerebrovascular and metabolic diseases were hardly affected by age and body mass index (BMI). Conclusion: We found that an increased DDE of animal zinc intake was associated with higher cardiovascular and metabolic risks among middle-aged women, which did not support the benefit of zinc intake in reducing cardiovascular and metabolic risks. The association seems to be incongruous with the anti-inflammation and antioxidation physiological functions of zinc. Thus, additional well-designed and prospective studies are needed to confirm this association.

Biomass Straw-Derived Porous Carbon Synthesized for Supercapacitor by Ball Milling.

A large amount of biomass straw waste is generated every year in the world, which can cause serious environmental pollution and resource waste if disposed of improperly. At present, biomass-derived porous carbon materials prepared from biomass waste as a carbon source have garnered attention due to their renewability, huge reserves, low cost, and environmental benevolence. In this work, high-performance carbon materials were prepared via a one-step carbonization-activation method and ball milling, with waste tobacco straw as precursor and nano-ZnO as template and activator. The specific surface area and porous structure of biomass-derived carbon could be controlled by carbonization temperature, which is closely related to the electrochemical performances of the carbon material. It was found that, when the carbonization temperature was 800 °C, the biochar possesses maximum specific surface area (1293.2 m2·g-1) and exhibits high capacitance of 220.7 F·g-1, at 1 A·g-1 current density in a three-electrode configuration with 6 M KOH aqueous solution. The capacitance retention maintained about 94.83% at 5 A·g-1 after 3000 cycles. This work proves the porous biochar derived from tobacco straws has a great potential prospect in the field of supercapacitors.

Involvement of Autophagy in the Protective Effects of Ginsenoside Rb1 in a Rat Model of Traumatic Brain Injury.

BACKGROUND AND OBJECTIVES: No treatment modalities have been identified to prevent neuron damage induced by traumatic brain injury (TBI). The objective of this study was to investigate whether ginsenoside Rb1 (GS-Rb1) could be utilized to exert neuroprotective effects in TBI. METHODS: Lateral fluid percussion injury (LFPI) was used to induce an experimental TBI model. Lewis rats were divided into a GS-Rb1 group (5, 10, 20 mg/kg, intraperitoneally injected daily), a sham group, and a vehicle group. Neurological impairments were assessed with brain water content, Evans blue extravasation, neurological deficit scores, and Morris water maze test. TUNEL and NeuN staining were utilized to detect neuron apoptosis. The relative expression of apoptosis- and autophagy-relevant molecules were assayed with real-time PCR and western blot. RESULTS: GS-Rb1 inhibited TBI-induced brain edema and Evans blue extravasation in a dose-dependent manner. Furthermore, GS-Rb1 improved neurological impairments with diminished neurological deficit scores, decreased escape latencies, increased time in the target quadrant, and increased number of platform site crossings. GS-Rb1 protected against neuron apoptosis with downregulated Bax expression and upregulated Bcl-2 expression. It was worth noting that TBI increased the LC3II/LC3I ratio and upregulated the relative expression of Beclin-1, Atg-7, and Atg-3; moreover, TBI downregulated the relative expression of P62. The administration of GS-Rb1 further strengthened the relative expression of autophagy-related molecules. CONCLUSIONS: GS-Rb1 alleviates neurological impairments induced by TBI with upregulated autophagy.

Performance of the microscopic observation drug susceptibility assay in pyrazinamide susceptibility testing for Mycobacterium tuberculosis.

BACKGROUND: Drug susceptibility assay is very important in tuberculosis therapy. Pyrazinamide is a first line antituberculosis drug and diagnosis of its resistance in Mycobacterium tuberculosis (M. tuberculosis) is difficult and time consuming by conventional methods. In this study, we aimed to evaluate the performance of the microscopic observation drug susceptibility (MODS) assay in the detection of pyrazinamide resistance in M. tuberculosis relative to the conventional Wayne assay and Lowenstein-Jensen (LJ) proportion method. METHODS: M. tuberculosis clinical isolates (n = 132) were tested by the MODS and the Wayne assay: the results were compared with those obtained by the LJ proportion method. Mutations in the gene were identified by direct sequencing of the pncA genes of all isolates in which pyrazinamide resistance was detected by any of the three methods. RESULTS: Compared to the LJ results, the sensitivity and specificity of the MODS assay were 97.8% and 96.5% respectively; the sensitivity and specificity of the Wayne assay were 87.0% and 97.7% respectively. Mutations in the pncA gene were found in 41 of 46 strains that were pyrazinamide resistant (3 tests), in 1 of the 4 strains (LJ only), in 42 of 48 strains (at least 1 test), but no mutations in 1 strain sensitive according to the MODS assay only. The MODS assay, Wayne assay and LJ proportion method provided results in a median time of 6, 7 and 26 days respectively. CONCLUSIONS: MODS assay offers a rapid, simple and reliable method for the detection of pyrazinamide resistance in M. tuberculosis and is an optimal alternative method in resource limited countries.