The Clinical Usefulness of Tuberculin Skin Test versus Interferon-Gamma Release Assays for Diagnosis of Latent Tuberculosis in HIV Patients: A Meta-Analysis

BackgroundAccurate diagnosis of latent tuberculosis infection (LTBI) is becoming increasingly concerning due to the increasing the HIV epidemic, which have increased the risk for reactivation to active tuberculosis (TB) infection. LTBI is diagnosed by tuberculin skin test (TST) and interferon-gamma release assays (IGRAs).ObjectivesThe aim of the present study was to conduct a meta-analysis of published papers on the agreement (kappa) between TST and QuantiFERON-TB Gold In-Tube (QFT-GIT) tests for diagnosis of LTBI in HIV patient.MethodsElectronic databases including PubMed/Medline, Elsevier/Scopus and Embase/Ovid were reviewed up Jan. 2016. We performed a random effect model meta-analysis for estimation of pooled Kappa between the two methods of diagnosis. Meta regression was used for assessing potential heterogeneity and Egger’s test was used for assessing small study effect and publication bias.ResultsThe initial search strategy produced 6744 records. Of them, 23 cross-sectional studies met the inclusion criteria and 20 studies entered in meta-analysis. The pooled kappa was and prevalence-adjusted and bias-adjusted kappa (PABAK) were 0.37 (95% CI: 0.28, 0.46) and 0.59 (0.49, 0.69). The discordance of TST-/QFT-GIT+ was more than TST+/QFT-GIT-. Kappa estimate between two tests was linearly associated with age and prevalence index and inversely associated with bias index.ConclusionFair agreement between TST and QFT-GIT makes it difficult to know whether TST is as useful as the QFT-GIT in HIV-infected patients. The higher discordance of TST-/QFT-GIT+ in compared to TST+/QFT-GIT- can induce the higher sensitivity of QFT-GIT for diagnosis LTBI in HIV patients. Disagreement between two tests can be influenced by error in measurements and prevalence of HIV.     

Studies on the synthesis of valienamine and 1-epi-valienamine starting from D-glucose or L-sorbose

Two synthetic routes to a carbocyclic precursor to valienamine are reported, starting from either D-glucose or L-sorbose and using ring-closing metathesis as a key step. A low-yielding synthesis of 1-epi-valienamine is reported. Results from an abortive third possible route to valienamine based on an early introduction of nitrogen are discussed.     

Stature estimation in ancient Egyptians: a new technique based on anatomical reconstruction of stature

Trotter and Gleser's (Trotter and Gleser: Am J Phys Anthropol 10 (1952) 469-514; Trotter and Gleser: Am J Phys Anthropol 16 (1958) 79-123) long bone formulae for US Blacks or derivations thereof (Robins and Shute: Hum Evol 1 (1986) 313-324) have been previously used to estimate the stature of ancient Egyptians. However, limb length to stature proportions differ between human populations; consequently, the most accurate mathematical stature estimates will be obtained when the population being examined is as similar as possible in proportions to the population used to create the equations. The purpose of this study was to create new stature regression formulae based on direct reconstructions of stature in ancient Egyptians and assess their accuracy in comparison to other stature estimation methods. We also compare Egyptian body proportions to those of modern American Blacks and Whites. Living stature estimates were derived using a revised Fully anatomical method (Raxter et al.: Am J Phys Anthropol 130 (2006) 374-384). Long bone stature regression equations were then derived for each sex. Our results confirm that, although ancient Egyptians are closer in body proportion to modern American Blacks than they are to American Whites, proportions in Blacks and Egyptians are not identical. The newly generated Egyptian-based stature regression formulae have standard errors of estimate of 1.9-4.2 cm. All mean directional differences are less than 0.4% compared to anatomically estimated stature, while results using previous formulae are more variable, with mean directional biases varying between 0.2% and 1.1%, tibial and radial estimates being the most biased. There is no evidence for significant variation in proportions among temporal or social groupings; thus, the new formulae may be broadly applicable to ancient Egyptian remains.     

In Vitro Electrochemical Corrosion and Cell Viability Studies on Nickel-Free Stainless Steel Orthopedic Implants

The corrosion and cell viability behaviors of nanostructured, nickel-free stainless steel implants were studied and compared with AISI 316L. The electrochemical studies were conducted by potentiodynamic polarization and electrochemical impedance spectroscopic measurements in a simulated body fluid. Cytocompatibility was also evaluated by the adhesion behavior of adult human stem cells on the surface of the samples. According to the results, the electrochemical behavior is affected by a compromise among the specimen''s structural characteristics, comprising composition, density, and grain size. The cell viability is interpreted by considering the results of the electrochemical impedance spectroscopic experiments.     

Increasing maternal age of blastocyst affects on efficient derivation and behavior of mouse embryonic stem cells

Mouse embryonic stem cells (mESCs) have the capability to undergo unlimited cell division and differentiate into derivatives of all three embryonic germ layers. These fundamental features enable mESCs to potentially be appropriate, efficient models for biological and medical research. Therefore, it is essential to produce high-performance mESCs. In the current study, we have produced mESCs from blastocysts that developed from fertilized oocytes of 2 (2-C57)-, 4 (4-C57)-, and 6 (6-C57)-month-old C57BL/6 mice. A comparison of isolated stem cells was done from the viewpoint of the efficiency of mESC derivation, self-renewal, and their differentiation capacity. All generated mESCs showed a similar expression of the molecular markers protein of pluripotency and AP activity. In the 3i medium, there was a significant decrease in undifferentiated marker genes expression in the 2-C57 cells compared with the other two groups ( P < 0.05) but developmental genes significantly increased in the 4-C57 and 6-C57 cells compared with the 2-C57 cells ( P < 0.05). The differentiation capacity into three germ layers through the embryoid body formation and percentage of cell lines with normal numbers of chromosomes reduced with increased maternal age. The highest DT and highest percentage of cells in the S phase belonged to 2-C57 cells. These data demonstrated that blastocysts which developed from fertilized oocytes of 2-, 4-, and 6-month-old C57BL/6 mice can generate pluripotent stem cells, and suggested that both the efficiency of mESC isolation and the behavior of these isolated mESCs including pluripotency, self-renewal, cell cycle, and DT changed with increasing maternal age.     

‘HypothesisFinder:’ A Strategy for the Detection of Speculative Statements in Scientific Text

Speculative statements communicating experimental findings are frequently found in scientific articles, and their purpose is to provide an impetus for further investigations into the given topic. Automated recognition of speculative statements in scientific text has gained interest in recent years as systematic analysis of such statements could transform speculative thoughts into testable hypotheses. We describe here a pattern matching approach for the detection of speculative statements in scientific text that uses a dictionary of speculative patterns to classify sentences as hypothetical. To demonstrate the practical utility of our approach, we applied it to the domain of Alzheimer''s disease and showed that our automated approach captures a wide spectrum of scientific speculations on Alzheimer''s disease. Subsequent exploration of derived hypothetical knowledge leads to generation of a coherent overview on emerging knowledge niches, and can thus provide added value to ongoing research activities.     

Designing a Non-invasive Surface Acoustic Resonator for Ultra-high Sensitive Ethanol Detection for an On-the-spot Health Monitoring System

Surface acoustic wave (SAW) sensors–based on piezoelectric crystal resonators–are extremely sensitive to even very small perturbations in the external atmosphere, because the energy associated with the acoustic waves is confined to the crystal surface. In this study, we present a critical review of the recent researches and developments predominantly used for SAW-based organic vapor sensors, especially ethanol. Besides highlighting their potential to realize real-time ethanol sensing, their drawbacks such as indirect sensing, invasive, time initializing, and low reliability, are properly discussed. The study investigates a proposed YZ-lithium niobate piezoelectric substrate with interdigital transducers patterned on the surface. Design of the resonator plays an important role in improving mass sensitivity, particularly the sensing area. Accordingly, a tin dioxide (SnO₂) layer with a specific thickness is generated on the surface of the sensor because of its high affinity to ethanol molecules. To determine the values of sensor configuration without facing the practical problems and the long theoretical calculation time, it is shown that the mass sensitivity of SAW sensors can be calculated by a simple three-dimensional (3-D) finite element analysis (FEA) using a commercial finite-element platform. In design validation step, different concentrations of ethanol are applied to investigate the acoustic wave properties of the sensor. The FEA data are used to obtain the surface and bulk total displacements of the sensor and fast Fourier transform (FFT) on output spectrum. The sensor could develop into highly sensitive and fast responsive structure so that a positive intensity shift of 0.18e-2 RIU is observed when the sensor is exposed to 15 ppm ethanol. It is capable of continuously monitoring the ethanol gas whether as an ultra-high sensitive sensor or switching applications for medical and industrial purposes.