A.S. Khanna

Effect of Nanoalumina on the Electrochemical and Mechanical Properties of Waterborne Polyurethane Composite Coatings

A nanocomposite coating was formed by incorporating nanoalumina pigment in a waterborne polyurethane dispersion (WPUD) to different loading levels (0.1% and 1.0% by weight). Electrochemical performance of the nanocomposite coating was evaluated by applying these nanomodified coatings on mild steel substrate and exposing them to salt-spray, humidity, and accelerated UV weathering. The surface morphology of the composite coating was evaluated using various analytical techniques. SEM and AFM were used to investigate the dispersion of nanoalumina pigment and surface morphological changes of the nanomodified coating, before and after exposure to the test environment. Mechanical properties like scratch resistance were studied by using nanoscratch technique (Nanoindenter TI-900, Hysitron Inc, USA) and hardness using pencil hardness test method. The results showed an improvement in the corrosion, UV weathering, and mechanical properties of the coatings at lower concentration (0.1% by wt), indicating the positive effect of addition of nanoalumina pigment to the coating.

Rapid detection of extensively drug-resistant (XDR-TB) strains from multidrug-resistant tuberculosis (MDR-TB) cases isolated from smear-negative pulmonary samples in an Intermediate Reference Laboratory in India

BACKGROUND Direct sputum smear microscopy is commonly used for diagnosing tuberculosis (TB). The objectives of the study were first, to determine the recovery of Mycobacterium tuberculosis in smear-negative sputum samples through liquid culture (using MGIT 960) and solid culture (using LJ slant) and second, to screen multidrug-resistant isolates through line probe assay and further third, to identify XDR isolates through MGIT second-line DST from these positive MDR cultures in Delhi region. METHODS In this study, the sample size was 717 (sputum smear AFB negative and culture positive for M. tuberculosis complex by both solid and liquid culture methods) MDRTB suspects who were enrolled from January 2014 to December 2014 at the Intermediate Reference Laboratory in New Delhi Tuberculosis Centre, New Delhi. Rapid line probe assay was performed on all culture-positive samples, which were direct smear-negative specimens, and LPA-confirmed MDR samples were tested on MGIT 960 second-line DST for identification of XDR strains. RESULTS An overall increase in the culture positivity (9.4%) among these smear-negative cases shows a good sign of recovery from M. tuberculosis infection in these samples. 717 (9.4%) positive cultures (MGIT+LJ) were subjected to line probe assay. Out of these 717 cultures, 9 (1.2%) were confirmed as NTM, 50 (7%) were MDR, 4 (0.6%) were mono-rifampicin resistant and 654 (91.2%) cultures were sensitive to both drugs Rif and Inh, respectively. Out of these 54 (50 MDR +4 mono-RIF resistant) cultures as screened by LPA, 1 (1.8%) was XDR, 10 (18.6%) were mono-ofloxacin resistant and 1 (1.8%) was mono-Kanamycin resistant. Sensitivity to both drugs KAN and OFX was seen in 42 (77.8%) cultures. CONCLUSIONS Since the bacterial load in direct smear-negative suspected MDR samples is less, it is important to recover mycobacteria by rapid liquid culture method in such samples. Initial screening for MDRTB is to be done in such cases by performing rapid molecular genotypic drug susceptibility test such as LPA. Baseline second-line DST is also done to rule out the XDR cases among them for rapid and better management of XDRTB patients.

Treatment seeking pathways in pediatric tuberculosis patients attending DOTS centers in urban areas of Delhi

BACKGROUND The treatment seeking pathways prior to initiation of Direct Observed Treatment Short-course Therapy (DOTS), provides the extent of patient and health system delays among pediatric tuberculosis (TB) patients. OBJECTIVES The study attempted to understand the treatment seeking pathways of pediatric TB patients under revised national tuberculosis control program (RNTCP). STUDY DESIGN AND SETTING It was a prospective observational study carried out from January 2015 to December 2015. A predesigned, pretested and semi-structured questionnaire was used to interview 141 caregivers of pediatric patients (0-14 years) at two chest clinics selected purposively. RESULTS Thirteen different treatment seeking pathways were identified and fever was the commonest symptom (41.8%) for seeking care from 1st health facility. Median time taken from onset of symptoms to first consultation varied from 1 to 144 weeks. More than half of the study subjects were first taken to a private practitioner (64.5%) followed by a pharmacist (19.1%) and trust in provider was the commonest reason for choosing the first care-provider in 52 (41.1%), followed by easy access or convenience in 49 (34.8%). CONCLUSION A significant delay was found in treatment initiation of patients with extra pulmonary tuberculosis (EPTB), those belonging to lower socio-economic class families, low literacy level of parents, who went to private facility first and availed more than three health facilities before diagnosis.

Tuberculosis and biologics in rheumatology: A special situation

India has a huge patient burden of rheumatic diseases (RDs) including rheumatoid arthritis. The use of biologics has transformed the treatment paradigm for RD; however, biologic treatment‐related infections (especially tuberculosis [TB]) are an area of potential concern for TB‐endemic nations like India. Anti‐tumor necrosis factor (TNF) therapy impairs the physiological TNF‐mediated signaling and may cause reactivation and dissemination of latent TB infection (LTBI). Careful screening is, thus, crucial in RD patients who are about to commence anti‐TNF treatment. To date, there is no consensus available for the screening, evaluation and treatment of LTBI as well as on the drug dosage and duration regimen (monotherapy or combination therapy) in the Indian population. An evidence‐based algorithm for LTBI screening and management in RD patients undergoing biologic disease‐modifying anti‐rheumatic drug therapy is suggested in this review for Indian rheumatologists. The proposed algorithm guides physicians through a step‐wise screening approach, including medical history, tuberculin skin test, interferon gamma release assay, chest radiograph and management of LTBI with isoniazid therapy or its combination with rifampicin. Further, the provided algorithm can aid the national bodies (such as National TB Control Program) in formulating recommendations for LTBI in this high‐risk population.