Low-cost diagnostic test for susceptible and drug-resistant tuberculosis in rural Malawi

Background: Rural settings where molecular tuberculosis diagnostics are not currently available need easy-to-use tests that do not require additional processing or equipment. While acid-fast bacilli (AFB) smear is the most common and often only tuberculosis diagnosis test performed in rural settings, it is labour intensive, has less-than-ideal sensitivity, and cannot assess tuberculosis drug susceptibility patterns. Objective: The objective of this study was to determine the feasibility of a multidrug-resistant (MDR) or extensively drug-resistant (XDR)-tuberculosis coloured agar-based culture test (tuberculosis CX-test), which can detect Mycobacterium tuberculosis growth and evaluate for drug susceptibility to isoniazid, rifampicin and a fluoroquinolone (i.e. ciprofloxacin) in approximately 14 days. Method: In this study, 101 participants were enrolled who presented to a rural health clinic in central Malawi. They were suspected of having active pulmonary tuberculosis. Participants provided demographic and clinical data and submitted sputum samples for tuberculosis testing using the AFB smear and tuberculosis CX-test. Results: The results showed a high level of concordance between the AFB smear (12 positive) and tuberculosis CX-test (13 positive); only one sample presented discordant results, with the molecular GeneXpert MTB/RIF® test confirming the tuberculosis CX-test results. The average time to a positive tuberculosis CX-test was 10 days. Of the positive samples, the tuberculosis CX-test detected no cases of drug resistance, which was later confirmed by the GeneXpert MTB/RIF®. Conclusion: These findings demonstrate that the tuberculosis CX-test could be a reliable low-cost diagnostic method for active pulmonary tuberculosis in high tuberculosis burden rural areas

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Redetermination of the crystal structure of tetralithium octafluoridozirconate(IV), Li4ZrF8, from single-crystal X-ray data

Presented herein is the crystal-structure redetermination of Li4ZrF8 from single-crystal X-ray data. Alkali zirconium fluorides are important in nuclear-relevant technologies, and zirconium is commonly employed as an analogue for tetravalent f-block elements. The previous structure report of this species is based on powder X-ray data [Dugat et al. (1995). J. Solid State Chem. 120, 187–196] but there has never been a refined structure model from single-crystal data. The octafluoridozirconate moieties are held together by electrostatic attraction to lithium ions without sharing of fluoride sites between zirconium(IV) ions

A rare positively charged nicotinic acid disulfide: 2,2′-dithiodinicotinic acid hydrochloride monohydrate

The title compound {systematic name: 3-carboxy-2-[2-(3-carboxypyridin-2-yl)disulfan-1-yl)]pyridin-1-ium chloride monohydrate}, C12H9N2O4S2+·Cl−·H2O, crystallizes in the triclinic space group P\overline{1}. A pair of 2-mercaptonicotinic acid moieties is connected by a 2,2′-disulfide bond with a dihedral angle of 78.79 (3)°. One of the N atom is protonated, as are both carboxylate groups, resulting in an overall +1 charge on the dimer. The structure comprises a zigzagging layer of the dimerized dithiodinicotinic acid rings, with charge-balancing chloride ions and water molecules between the layers. Hydrogen bonding between the chloride and water sites with the dimer appears to hold the structure together. Nearest neighbor nicotinic acid rings are offset when viewed down the a axis, suggesting no added stability from ring stacking. The asymmetric unit corresponds to the empirical formula of the compound, and it packs with two formula units per unit cell

Assessing the Acceptability, Feasibility, and Effectiveness of a Tablet-Based Cervical Cancer Educational Intervention.

Cervical cancer is a common and deadly disease, especially in developing countries. We developed and implemented an interactive, tablet-based educational intervention to improve cervical cancer knowledge among women in rural Malawi. Chichewa-speaking adult women in six rural villages participated. Each woman took a pre-test, participated in the lesson, and then took a post-test. The lesson included information on cervical cancer symptoms, causes, risk factors, prevention, and treatment. Over the 6-month study period, 243 women participated. Women ranged in age from 18 to 77 years. Only 15% had education beyond primary school. Nearly half of participants (48%) had heard of cervical cancer prior to viewing the lesson. For these women, the median number of correct responses on the pre-test was 11 out of 20; after the lesson, they had a median of 18 correct responses (p<0.001). After the intervention, 93% of women indicated a desire for cervical cancer screening. Despite lack of familiarity with computers (96%), most women (94%) found the tablet easy to use. A tablet-based educational program was an effective, feasible and acceptable strategy to disseminate cervical cancer information to women with low education in rural Malawi. This method may be appropriate to distribute health information about other health topics in low-resource settings