A study to explore the factors related to treatment seeking delay among adults diagnosed with acute myocardial infarction at KMCH, Coimbatore

Objective The main aim of the study was to explore the factors causing delay in seeking treatment among adult patients diagnosed with CAAs acute myocardial infarction (AMI) and compare the factors between timely and late treatment seeking groups. Method A total of 93 subjects were included in the study diagnosed with AMI interviewed within 48 h of hospitalization. Data were collected from onset of symptoms to arrival at hospital on demography, clinical profile, clinical factors, cognitive factors and social support factors. Subjects were categorized in two study groups i.e. timely treatment seeking group (<120 min from onset of symptoms) and delayed treatment seeking group (>120 min from onset of symptoms). Results The minimum and maximum time took by subjects to seek treatment was 10 and 5450 min, respectively. The mean pain score of subjects who sought delayed treatment (2.2619) is less than those who sought timely treatment (3.3725). The mean knowledge score (12.2754), mean symptom perception (3.6667), mean perceived seriousness (4.7647) is more in subjects who sought timely treatment than those who sought delayed treatment (5.7381), (1.3095), (1.8333) respectively. The mean family support score (57.4492), mean non-family support score (24.902), mean social support score (48.3002) is more in timely treatment group than in delayed treatment seeking group (42.6829), (4.7619), (29.2138) respectively. Conclusion Decreased pain, knowledge about AMI, symptom perception, perceived seriousness respectively and inadequate family & non-family support i.e. social support were the factors related to treatment seeking delay among adults diagnosed with AMI.

Non-syndromic Supplemental Permanent Maxillary Lateral Incisor: A Rare Case Series.

Supernumerary teeth, or hyperdontia, are the additional teeth to the normal series and are seen in all quadrants of the jaw. They have been reported to occur in both primary and permanent dentition. The supplemental supernumerary refers to duplication of teeth in the normal series and is found at the end of the tooth series. The majority of supernumeraries found in primary dentition are of the supplemental type. It is rare and was overlooked because of their normal size and shape. Hereby, we report three cases of supplemental maxillary permanent lateral incisor which resulted in crowding and poor esthetics. This case series reports unilateral supplemental teeth and its management.

Effect of efflux pump inhibitors on drug susceptibility of ofloxacin resistant Mycobacterium tuberculosis isolates.

Background & objectives In drug resistant, especially multi-drug resistant (MDR) tuberculosis, fluoroquinolones (FQs) are used as second line drugs. However, the incidence of FQ-resistant Mycobacterium tuberculosis is rapidly increasing which may be due to extensive use of FQs in the treatment of various other diseases. The most important known mechanism i.e., gyrA mutation in FQ resistance is not observed in a significant proportion of FQ resistant M. tuberculosis isolates suggesting that the resistance may be because of other mechanisms such as an active drug efflux pump. In this study we evaluated the role of the efflux pumps in quinolone resistance by using various inhibitors such as carbonyl cyanide m-chlorophenyl hydrazone (CCCP), 2,4-dinitrophenol (DNP) and verapamil, in clinical isolates of M. tuberculosis. Methods A total of 55 M. tuberculosis clinical isolates [45 ofloxacin (OFL) resistant and 10 ofloxacin sensitive] were tested by Resazurin microtitre assay (REMA) to observe the changes in ofloxacin minimum inhibitory concentration (MIC) levels in presence of efflux inhibitors as compared to control (without efflux inhibitor). Results The MIC levels of OFL showed 2-8 folds reduction in presence of CCCP (16/45; 35.5%), verapamil (24/45; 53.3%) and DNP (21/45; 46.6%) while in case of isolates identified as OFL sensitive these did not show any effect on ofloxacin MICs. In 11 of 45 (24.5%) isolates change in MIC levels was observed with all the three inhibitors. Overall 30 (66.6%) isolates had reduction in OFL MIC after treatment with these inhibitors. A total of eight isolates were sequenced for gyrA gene, of which, seven (87.5%) showed known mutations. Of the eight sequenced isolates, seven (87.5%) showed 2 to 8 fold change in MIC in presence of efflux inhibitors. Interpretation & conclusions Our findings suggest the involvement of active efflux pumps of both Major Facilitator Super Family (MFS) family (inhibited by CCCP and DNP) and ATP Binding Cassette (ABC) transporters (inhibited by verapamil) in the development of OFL resistance in M. tuberculosis isolates. Epidemiological significance of these findings needs to be determined in prospective studies with appropriate number of samples / isolates.

jefA (Rv2459), a drug efflux gene in Mycobacterium tuberculosis confers resistance to isoniazid & ethambutol.

Background & objectives: Drug efflux pumps have been contributing factor(s) in the development of multidrug resistance in various clinically relevant bacteria. During efflux pump gene expression studies on mycobacteria, we have found a previously uncharacterized open reading frame (ORF) Rv2459 to be overexpressed in drug stressed conditions. The objective of the present study was to investigate the role of this ORF as a drug efflux pump, which might add new information in our understanding about the alternative mechanisms of drug resistance in mycobacteria. Methods: The open reading frame Rv2459 of Mycobacterium tuberculosis encoding a probable drug efflux protein has been cloned using pSD5 E.coli-Mycobacterium shuttle vector and overexpressed in M. tuberculosis H37Rv. This ORF was named as jefA. Overexpression of this gene in clones has been verified by real-time reverse transcription PCR. Minimum inhibitory concentrations (MICs) of recombinant as well as non-recombinant clones were determined by resazurin microtitre assay plate method (REMA) with and without efflux pump inhibitors carbonyl cyanide m-chlorophenylhydrazone (CCCP) and verapamil. Results: In recombinant strains of M. tuberculosis, the overexpression of this gene led to an increase in MIC of anti-tubercular drugs isoniazid and ethambutol when tested by REMA. In the presence of CCCP and verapamil, the recombinant strains showed decrease in MIC for these drugs. Bioinformatic analysis has shown a close relation of JefA protein with drug efflux pumps of other clinically relevant bacteria. In homology derived structure prepared from nearest available model, it was observed that amino acids forming TMH 1, 8 and 11 participated in ethambutol specificity and those forming TMH 2, 7 and 10 participated in isoniazid specificity in JefA. Interpretation & conclusion: The increased transcription of jefA leads to increased resistance to ethambutol and isoniazid in M. tuberculosis via efflux pump like mechanism and contributes in the development of resistance to these drugs. JefA amino acid sequence is well conserved among clinically important bacterial genera, which further provides evidence of being a potent drug efflux pump. The involvement in drug resistance and very little homology with any of the human proteins makes JefA important to be included in the list of potential drug targets.

In vitro effect of fl uoroquinolones against Mycobacterium tuberculosis isolates from Agra & Kanpur region of north India.

Background & objectives: Fluoroquinolones (FQs) are important drugs used for treatment of drug resistant tuberculosis and are also now being considered as fi rst line drugs to shorten the duration of treatment of tuberculosis (TB). In order to fi nd out useful FQs for treatment of tuberculosis, the comparative effi cacy of fi ve FQs, namely, ofl oxacin (OFL), ciprofl oxacin (CIP), sparfl oxacin (SPX), gatifl oxacin (GAT) and levofl oxacin (LEVX) was studied against Mycobacterium tuberculosis (MTB) isolates obtained from both treated and untreated patients from Agra and Kanpur regions of north India. Methods: A total of 162 MTB isolates [including 110 MTB isolates obtained from untreated patients (Cat-I) and 52 isolates from treated patients (Cat-II)] were tested for their susceptibilities to FQs using standard minimum inhibitory concentration (MIC) method on Löwenstein-Jensen medium. Results: Keeping in view the therapeutically achievable drug levels, it was found that in Cat-I 97.2 per cent (107/110) isolates were sensitive to GAT, 89 per cent (98/110) to LEVX at 1 μg/ml whereas 92.7 per cent (102/110) isolates were inhibited by OFL at 2 μg/ml and 73.6 per cent (81/110) to SPX at 0.5 μg/ml. Only 63.6 per cent (70/110) isolates were found to be sensitive to CIP at 2 μg/ml which increased to 89 per cent (98/110) at 4 μg/ml (higher than achievable peak serum level). On the other hand, among 52 isolates for Cat-II, 37 (71.2%) were found to be sensitive to GAT and 33 (63.5%) to LEVX at 1 μg/ml concentration, 28 (53.8%) to SPX at 0.5 μg/ml whereas 33 (63.5%) and 24 (46.2%) isolates were found to be sensitive to OFL and CIP at 2 μg/ml, respectively. Interpretation & conclusions: It appears that GAT has higher activity against MTB isolates followed by OFL, LEVX and SPX whereas CIP showed the lowest activity. GAT was also found to be the most effective FQ against multi-drug resistant (MDR) isolates both from Cat-I and Cat-II patients. Thus, except CIP, other FQs showed potential to be included in the treatment regimens of tuberculosis including MDR-TB.

The paradox of pyrazinamide: an update on the molecular mechanisms of pyrazinamide resistance in Mycobacteria.

Pyrazinamide (PZA) is an important front line anti-tuberculosis drug because of its sterilizing activity against semi-dormant tubercle bacilli. In spite of its remarkable role in shortening the treatment duration from 9 months to 6 months when used in combination with Rifampicin and Isoniazid, PZA remains a difficult paradox because of its incompletely understood mode of action and mechanism of resistance. PZA is a nicotinamide analog prodrug which is converted into the active bactericidal form pyrazinoic acid by the bacterial enzyme pyrazinamidase (PZase). PZA does not appear to have a specific cellular target and instead, exerts its bactericidal effect by disrupting the membrane energetics and acidification of cytoplasm. Majority (72-97%) of PZA-resistant isolates of M. tuberculosis exhibit mutations in their pncA gene or upstream area leading to loss of PZase activity. A wide diversity of pncA mutations scattered along the entire length of pncA gene is unique to PZA resistance. However, PZA resistant isolates with normal PZase activity and wild type pncA sequences have also been reported in several studies which indicate that alternate mechanisms of PZA resistance exist. Investigations into these mechanisms would be useful in developing alternative diagnostic/therapeutic measures. This review presents the update of various mechanisms of PZA resistance in different mycobacteria with special emphasis on mode of action of PZA and mechanisms of resistance in Mycobacterium tuberculosis.

Estimation of efflux mediated multi-drug resistance and its correlation with expression levels of two major efflux pumps in mycobacteria.

Multidrug resistance has been posing an increasing problem in the treatment of tuberculosis. Mutations in the genomic targets of drugs have been identified as the major mechanism behind this resistance. However, high degree of resistance in some isolates towards major drugs like rifampicin, isoniazid, ethambutol and streptomycin can not be explained solely on the basis of mutations. Besides this, certain other mechanisms like efflux pumps have also been considered as alternative mechanisms in the drug resistant isolates where there is no mutation and these mechanisms are specially important for drug resistance in non-tuberculous mycobacteria (NTM). In this study, we have estimated efflux pump mediated drug resistance in different mycobacterial species with the help of efflux pump inhibitors. All major anti-tuberculous drugs have been shown to be extruded by efflux pumps and the degree to which these drugs are extruded, vary in different mycobacterial species and isolates. The correlation of this resistance with functional activity of two major efflux pump genes pstB and Rv1258c was also assessed by reverse transcription PCR. Besides the significant role of these pumps observed, other efflux pumps, present in mycobacteria, may also be involved in drug resistance and need to be investigated.

Analysis of mycobacterial strains by two-dimensional gel electrophoresis.

This study pertains to analysis of the protein profile of different mycobacterial strains by two-dimensional gel electrophoresis (2DE). The strains were selected as they exhibit different phenotypic behaviour. TCA-acetone precipitated proteins were resolved by 2DE using immobilized pH gradient (IPG) strips. This study demonstrates that 2DE may be used as a tool for characterization of mycobacterial strains. Visual examination of the electrophoretograms was sufficient for characterization. Detailed characterization of specific proteins might lead to development of novel targets, diagnostic probes or sub-unit vaccine(s) against tuberculosis.

Early coronary aneurysm with Paclitaxel-eluting stent.

Coronary aneurysm may occur after implantation of a paclitaxel-eluting stent. However, early coronary aneurysms arevery rare. We report an early coronary aneurysm at one month in a middle-aged man who had anterior descendingartery infarct angioplasty done with two overlapped Taxus Liberte stents. Our finding was a fortuitous one. The casedescribed here illustrates the need for a higher index of suspicion for a coronary aneurysm when overlapping drug-eluting stents are used, especially in an infarct angioplasty.

Bioavailability of dapsone on oral administration of Dapsomine--a comparative evaluation.

This study describes a comparative evaluation of dapsone kinetics in humans on administration of Dapsomine, a capsule containing dapsone 100 mg dispersed in oily-base suspension of clofazimine 50 mg. Seven untreated lepromatous leprosy patients were given one capsule of Dapsomine a day for seven days and the pharmacokinetics parameters in this group were compared with those from another group of seven patients who received dapsone 100 mg and clofazimine 50 mg separately. There were no statistically significant differences in parameters such as peak dapsone plasma concentration (Cmax), basal plasma level (C24h), time to peak level (tmax), absorption half-life (t1/2 alpha), elimination half-life t1/2 beta) and areas under plasma concentration-time curves (AUC0-8h) and AUC0-24h) between the two groups.

Correlation between inhibitory effect of quinolones and mycolic acid metabolism in mycobacteria.

Mycolic acids are important components having a significant role in maintaining the rigidity of mycobacterial cell wall. They could also be the barrier for penetration of certain drugs into the bacterial cell. A novel in vitro model system was established for assessing the effect of Ciproflaxacin on mycolic acid metabolism in pathogenic mycobacteria M. Kansasii (which has similar mycolic acid pattern to that from M. leprae) and the effect of norfloxacin in M. intracellulare. These test mycobacteria were exposed in their midlogarithmic phase of growth to 0.5, 1, 2, 3, 4, 5 and 6 micrograms ml of ciprofloxacin and norfloxacin respectively for 1, 2 and 24 hours. Ciprofloxacin completely inhibited the synthesis of mycolates in M. kansasii at 3, 4 and 5 micrograms/ml; whereas norfloxacin exhibited its maximum inhibitory action on mycolic acids in M. intracellulare at 6 micrograms/ml for all the durations of exposure. Inhibition of mycolates directly correlated with bacterial viability which was estimated by colony forming units. The effect of quinolones on mycolic acid metabolism appears to be direct and not secondary to DNA gyrase. The results obtained from this study and our previous findings show that mycolic acid metabolism is affected by various groups of drugs, whose primary sites of activity may be different. The findings of the present study may have significant therapeutic implications in leprosy and other mycobacterial diseases.

Evaluation of effectiveness of clofazimine therapy. I. Monitoring of absorption of clofazimine from gastrointestinal tract.

The quantity of clofazimine absorbed from the gastrointestinal tract when administered to lepromatous leprosy patients at varying single doses of 600 mg., 400 mg., 300 mg., and 100 mg. has been worked out by determining the amount of clofazimine present in total faecal excreta. Except in 100 mg. dose where the percentage absorption was 62.5 +/- 17 in all other case the values were around 45%. The efficacy of daily administration of 100 mg. clofazimine is discussed in this first article.

Alanine dehydrogenase in mycobacteria--a preliminary report.

Various mycobacterial species namely M. phlei, M. vaccae, M. scrofulaceum, M. avium and M. tuberculosis have been investigated for the presence of enzyme alanine dehydrogenase which could be important for utilization of alanine by TCA cycle. It was found that alanine dehydrogenase was present in all species of mycobacteria tested irrespective of the fact whether they are rapid or slow growers. Electrophoretic mobilities of alanine dehydrogenase from different species of mycobacteria were not found to be significant for taxonomical differentiation of rapid and slow growers.