The utility of IS6110 sequence based polymerase chain reaction in comparison to conventional methods in the diagnosis of extra-pulmonary tuberculosis

IS6110 sequence based polymerase chain reaction (PCR) was compared with conventional bacteriological techniques in the laboratory diagnosis of extra-pulmonary tuberculosis (EPTB). One hundred and ninety one non-repeated clinical samples of EPTB and 17 samples from non-tuberculous cases as controls were included. All the samples were processed for Ziehl-Neelsen staining for acid fast bacilli (AFB) and 143 samples were processed by culture for M. tuberculosis . All the samples were processed for PCR amplification with primers targeting 123 bp fragment of insertion element IS6110 of M. tuberculosis complex. Of the total 191 samples processed, 34 (18%) were positive by smear for AFB. Culture for AFB was positive in 31(22%) samples among the 143 samples processed. Either smear or culture for AFB was found positive in 51(27%) samples. Of the total 191 samples processed 120 (63%) were positive by PCR. In 140 samples, wherein both the conventional techniques were found negative, 74 (53%) samples were positive by PCR alone. Among 51 samples positive by conventional techniques, 46 (90%) were found positive by PCR. PCR assay targeting IS6110 is useful in establishing the diagnosis of EPTB, where there is strong clinical suspicion, especially when the conventional techniques are negative.     

Hepatic sortilin regulates both apolipoprotein B secretion and LDL catabolism

Genome-wide association studies (GWAS) have identified a genetic variant at a locus on chromosome 1p13 that is associated with reduced risk of myocardial infarction, reduced plasma levels of LDL cholesterol (LDL-C), and markedly increased expression of the gene sortilin-1 (SORT1) in liver. Sortilin is a lysosomal sorting protein that binds ligands both in the Golgi apparatus and at the plasma membrane and traffics them to the lysosome. We previously reported that increased hepatic sortilin expression in mice reduced plasma LDL-C levels. Here we show that increased hepatic sortilin not only reduced hepatic apolipoprotein B (APOB) secretion, but also increased LDL catabolism, and that both effects were dependent on intact lysosomal targeting. Loss-of-function studies demonstrated that sortilin serves as a bona fide receptor for LDL in vivo in mice. Our data are consistent with a model in which increased hepatic sortilin binds intracellular APOB-containing particles in the Golgi apparatus as well as extracellular LDL at the plasma membrane and traffics them to the lysosome for degradation. We thus provide functional evidence that genetically increased hepatic sortilin expression both reduces hepatic APOB secretion and increases LDL catabolism, providing dual mechanisms for the very strong association between increased hepatic sortilin expression and reduced plasma LDL-C levels in humans.     

Morphological analysis of the maxillary arch and hard palate in edentulous maxilla of South Indian dry skulls

Purpose

The purpose of this study is to demonstrate the role of aging\edentulousness on the maxillary arch, the size of the alveolar process, the shape and thickness of the hard palate in the South Indian dry skulls to customize more appropriate treatment of elderly edentulous patients.

Methods

One hundred dry skulls were divided into dentate and edentulous groups and were subgrouped into male and female. They were subjected to various morphological and morphometrical analyses.

Results

The data have revealed a more significant reduction in the depth and width (p?p?p?Conclusion The observed data from specific group of population may provide relevant data for their comparative analysis between different populations for a better understanding of their regional differences with respect to environmental and social influence. Moreover, the data can provide a better idea to evaluate a promising treatment strategy in prosthodontics and orthodontics in South India.     

Systematic control of protein interaction using a modular ER/K α-helix linker

Cellular functions of proteins are strongly influenced by their interactions with other proteins. The frequency of protein interactions is a function of the local concentration of two proteins and their affinity for one another. When two proteins are tethered together, the link between them influences their effective concentrations and therefore the frequency of their interaction. Currently no methods exist to systematically vary the effective concentration within this intramolecular interaction. Here we outline a modular, genetically encoded linker, namely, an ER/K [genetically encoded polypeptide motif based on alternating sequence of approximately four glutamic acid (E) followed by approximately four arginine (R) or lysine (K) residues] single α-helix that can be used to regulate the frequency of interaction between two proteins, or between a protein and a peptide, one at each end. We exploit the wide range of interaction affinities between calmodulin and its binding peptides, combined with FRET to determine the effect of the ER/K α-helix in regulating protein interactions. We find that increasing the length of the ER/K α-helix reduces the on rate of the intramolecular interaction without significantly affecting the off rate, regardless of the affinity of the bimolecular interaction. We outline a genetically encoded approach to determine the dissociation constant for both moderate (micromolar K(d)) and strong (nanomolar K(d)) protein interactions. Our studies demonstrate the use of the ER/K α-helix to systematically engineer FRET biosensors that detect changes in concentration or affinity of interacting proteins, and modulate enzyme autoinhibition. Our findings are consistent with the ER/K α-helix as a worm-like chain with rare, stochastic breaks in the helix backbone that may account for the behavior of myosin VI stepping along actin.     

Carbapenem-resistant <Emphasis Type="Italic">Enterobacteriaceae</Emphasis> in pediatric bloodstream infections in rural Southern India

Objective

To measure the frequency of antimicrobial resistance in pediatric blood culture isolates of Escherichia coli and Klebsiella spp. with focus on carbapenem resistance.

Methods

Over a period of three years, pediatric blood culture isolates were tested for antimicrobial susceptibility, including molecular investigations for carbapenem resistance.

Results

Amikacin, carbapenems, colistin and tigecycline had an antimicrobial efficacy of >70% (n=140). 7 of the 15 randomly selected isolates were positive for carbapenemase gene; among them, five were New Delhi Metallo β-lactamase (NDM).

Conclusion

There was a high prevalence of Klebsiella spp. in pediatric bacteremia and dissemination of NDMmediated carbapenem resistance in pediatric wards.

     

Darunavir/ritonavir pharmacokinetics following coadministration with clarithromycin in healthy volunteers

This study investigated the steady-state pharmacokinetic interaction between the HIV protease inhibitor, darunavir (TMC114), administered with low-dose ritonavir (darunavir/ritonavir), and clarithromycin in HIV-negative healthy volunteers. In a 3-way crossover study, 18 individuals received darunavir/ritonavir 400/100 mg bid, clarithromycin 500 mg bid, and darunavir/ritonavir 400/100 mg bid plus clarithromycin 500 mg bid in 3 separate sessions for 7 days, with a washout period of at least 7 days between treatments. Pharmacokinetic assessment was performed on day 7. Safety and tolerability of the study medication were monitored throughout. Coadministration of darunavir/ritonavir with clarithromycin resulted in a reduction in darunavir maximum plasma concentration (Cmax) and area under the curve from administration until 12 hours postdose (AUC12 h) of 17% and 13%, respectively. Ritonavir Cmax and AUC12 h were unchanged. During coadministration with darunavir/ritonavir, clarithromycin Cmax and AUC12 h increased by 26% and 57%, respectively; 14-hydroxy-clarithromycin plasma concentrations were reduced to below the lower limit of quantification (<50 ng/mL). The study medication was generally well tolerated. Based on these pharmacokinetic findings, neither clarithromycin nor darunavir/ritonavir dose adjustments are necessary when clarithromycin is coadministered with darunavir/ritonavir.     

Application of modeling and simulation to integrate clinical pharmacology knowledge across a new drug application

Typical drug development includes few studies to find the right dose/dosing regimen and several other bridging studies evaluating various prognostic factors (e.g.: co-administration of other drugs, organ failure). The drug sponsors and the regulators use this information to formulate labeling instructions for safe and effective use of the drug. In the current article, modeling and simulation are proposed as tools to integrate the knowledge from the effectiveness/safety studies and the bridging studies. Simulations allow exploring the impact of various prognostic factors on the effectiveness and safety. The concept is exemplified using the new drug application of an anti-migraine drug. The exercise aids in integrating all the knowledge across the drug development to suggest rationale dosing strategies; effectively communicating the impact of the prognostic factors to the clinicians/regulators; and protect against any intellectual losses due to development team changes.