Microbial colonization of Provox voice prosthesis in the Indian scenario

INTRODUCTION

Tracheoesophageal speech using the voice prosthesis is considered to be the "gold standard" with success rates as high as 90%. Despite significant developments, majority eventually develop dysfunction due to microbial deterioration. We did a pilot study of 58 laryngectomy patients who developed prosthesis dysfunction.

MATERIALS AND METHODS

A total of 58 laryngectomy patients who had their dysfunctional prosthesis removed were included in this study. Dysfunctional prostheses were removed and examined. Esophageal and tracheal flanges were examined separately. After obtaining pure fungal and bacterial cultures, the yeast strains were identified. Bacteria were identified with the light microscope and gram staining. We analyzed prosthesis lifespan and probable factors affecting it.

RESULTS

Central leak was found in 43% cases while in 57% peri-prosthetic leakage was the most common reason for prosthesis replacement. Microbial analysis revealed a combination of yeast and bacteria in approximately 55% culture samples. Out of these, almost 90% had the presence of single yeast species with bacteria. Pure fungal culture was identified in rest of the 45% cultures while none detected pure bacterial forms. Candida tropicalis was the solitary yeast in 81% while Candida albicans was seen in 10% as the solitary yeast. Bacterial isolates revealed Klebsiella pneumonia in 19%, Escherichia coli in 8% while Staphylococcus aureus was grown in 1% cultures. The consumption of curd (P = 0.036, 95% confidence intervals [CI]: 2.292-64.285) to have a significant correlation of the mean prosthesis lifespan. Consumption of curd (P = 0.001, 95% CI: 0.564-2.008) and history of prior radiotherapy (P = 0.015, 95% CI: 0.104-0.909) had a significant bearing on the Provox prosthesis lifespan.

CONCLUSIONS

Candida is the most common organism grown on voice prosthesis in Indian scenario. Consumption of curd and history of prior radiotherapy significantly affect Provox prosthesis lifespan.

Antigen sequence typing of outer membrane protein (fetA) gene of Neisseria meningitidis serogroup A from Delhi & adjoining areas

BACKGROUND & OBJECTIVES

Meningitis caused by Neisseria meningitidis is a fatal disease. Meningococcal meningitis is an endemic disease in Delhi and irregular pattern of outbreaks has been reported in India. All these outbreaks were associated with serogroup A. Detailed molecular characterization of N. meningitidis is required for the management of this fatal disease. In this study, we characterized antigenic diversity of surface exposed outer membrane protein (OMP) FetA antigen of N. meningitidis serogroup A isolates obtained from cases of invasive meningococcal meningitis in Delhi, India.

METHODS

Eight isolates of N. meningitidis were collected from cerebrospinal fluid during October 2008 to May 2011 from occasional cases of meningococcal meningitis. Seven isolates were from outbreaks of meningococcal meningitis in 2005-2006 in Delhi and its adjoining areas. These were subjected to molecular typing of fetA gene, an outer membrane protein gene.

RESULTS

All 15 N. meningitides isolates studied were serogroup A. This surface exposed porin is putatively under immune pressure. Hence as a part of molecular characterization, genotyping was carried out to find out the diversity in outer membrane protein (FetA) gene among the circulating isolates of N. meningitidis. All 15 isolates proved to be of the same existing allele type of FetA variable region (VR) when matched with global database. The allele found was F3-1 for all the isolates.

INTERPRETATION & CONCLUSIONS

There was no diversity reported in the outer membrane protein FetA in the present study and hence this protein appeared to be a stable molecule. More studies on molecular characterization of FetA antigen are required from different serogroups circulating in different parts of the world.

Genetic variant in the BCL11A (rs1427407), but not HBS1-MYB (rs6934903) loci associate with fetal hemoglobin levels in Indian sickle cell disease patients

India along with Nigeria and DRC contribute to 57% of the world sickle cell anemia population. The annual number of newborns in India with SCA was estimated at 44,000 in 2010. Even with this high prevalence there is minimal information about genetic factors that influence the disease course in Indian patients. The current study was conducted on 240 patients with SCD and 60 with sickle cell trait, to determine the association of genetic variants at the BCL11A (rs1427407) and HBS1-MYB (rs6934903) loci with fetal hemoglobin levels (HbF). Both these loci have been implicated with influencing HbF levels, a powerful modulator of the clinical and hematologic features of SCD. Our results indicate the BCL11A rs1427407 G>T variant to be significantly associated with HbF levels {19.12±6.61 (GG), 20.27±6.92 (GT) and 24.83±2.92 (TT) respectively} contributing to ~23% of the trait variance. Interestingly no association of the HBS1L-MYB rs6934903 with the HbF levels was seen. The present study indicates the BCL11A (rs1427407) but not HMIP (rs6934903) to be associated with elevated HbF levels in Indian patient. Further interrogation of additional variants at both the loci; as also a GWAS which may help uncover new loci controlling HbF levels.

Factors predicting 'time to distant metastasis' in radically treated head and neck cancer

Context: Various studies have shown the important risk factors for distant metastasis in head and neck cancer (HNC) which are present in most of the patients in developing countries. Identification of factors on the basis of time to distant metastasis (TDM) can help in future trials targeting smaller subgroups. Aims and Objectives: To identify the factors that predict TDM in radically treated HNC patients. Settings and Design: Retrospective audit. Materials and Methods: Retrospective audit of the prospectively maintained electronic database of a single HNC radiotherapy clinic from 1990 to 2010 was done to identify radically treated patients of HNC who developed distant metastasis. Univariate and multivariate analysis were done to identify baseline (demographic, clinical, pathological, and treatment) factors which could predict TDM, early time to metastasis (ETM; <12 months), intermediate time to metastasis (ITM; 12-24 months), and late time to metastasis (LTM; >2 years) using Kaplan Meier and Cox regression analysis, respectively. Results: One hundred patients with distant metastasis were identified with a median TDM of 7.4 months; 66 had ETM, 17 had ITM, and 17 had LTM. On multivariate analysis, the nodal stage 2-3 (N2/3) was the only baseline factor independently predicting TDM, ETM, and ITM, whereas none of the baseline factors predicted LTM. Conclusions: Higher nodal burden (N2/3) is associated with both ETM and ITM, and calls for aggressive screening, systemic therapy options, and surveillance. It is difficult to predict patients who are at a risk of developing LTM with baseline factors alone and evaluation of biological data is needed.

Rapid culture diagnosis of tuberculous lymphadenitis from a tertiary care centre in an endemic nation: potential and pitfalls

In spite of low sensitivity and specificity, standard diagnostic algorithm recommends fine needle aspiration cytology (FNAC) and direct microscopic screening for acid-fast bacilli (AFB) for the routine diagnosis of tuberculous lymphadenopathy (LNTB). In this study, the diagnostic utility of liquid broth based automated culture (BacT/ALERT 3D) technique was assessed in comparison with conventional techniques in 89 clinically suspected tubercular lymphadenitis patients. 60% (n = 53) were positive by FNAC and 38.4% (n = 34) demonstrated AFB in smear examination. BacT/ALERT yielded isolation in 43.1% (n = 38) aspirates, confirming tubercular aetiology. We also found six paediatric culture-positive cases which showed negative outcome by both FNAC and smear. Thus, we conclude that culture by BacT/ALERT, may be used for faster yield of Mycobacteria in LNTB, especially in children. Additionally, this could also be used as a platform for further differentiation of Mycobacterium tuberculosis from non-tuberculous mycobacteria (NTM) infection and for testing of anti-tubercular chemotherapeutic agents whenever drug resistance is suspected.

In vivo redox state of human thioredoxin and redox shift by the histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA)

The cytosolic thioredoxin (Trx1) system is essential for maintaining a reduced intracellular environment, via reduced Trx1 acting as a general protein disulfide reductase. Trx1 is implicated in cell signaling such as proliferation, DNA synthesis, enzyme activation, cell cycle regulation, transcription, gene activation, and prevention of apoptosis. Human Trx1 contains the active-site cysteines, Cys32 and Cys35, and three additional structural cysteines, Cys62, Cys69, and Cys73, that regulate Trx1 structure and activity via a second disulfide formation, S-glutathionylation or S-nitrosylation. The present study uses an electrophoretic redox Western blot method to analyze the oxidation state of Trx1 in vivo separating the protein-changed isoform following alkylation with iodoacetic acid in 8M urea. Treatment with the histone deacetylase inhibitor SAHA increased Trx1 inhibitor thioredoxin interacting protein (Txnip) levels, decreased Trx1 activity, and switched the Trx1 oxidation state toward a more oxidized one, as a result of complex formation with Trx1, and increased reactive oxygen species (ROS). SAHA is currently in clinical trials for cancer treatment, and one possible mechanism for its anticancer effect is via effects on the Trx1 system. Determining the exact oxidation state of human cytosolic Trx1 may be useful in developing and evaluating cancer drugs and antioxidant agents.

Sore throat - a review of presentation and etiology

A commonly encountered complaint in clinical practice is that of a sore throat. However, confusion prevails in the minds of the treating specialists as to what treatment protocol should be followed and how to differentiate it from tonsilliti. It was with a view to clarifying this issue that a prospective study was undertaken on 50 patients with the presenting complaint of a sore throat, of which 20 received medical treatment and 30 underwent a tonsillectomy. The preoperative throat swabs versus fine needle aspiration cultures and core cultures were also analyzed us were some predisposing factors. Available literature was reviewed and compared with findings of the current study. On the bash of this, a protocol for treatment was developed including antibiotic preference and best method of microbiological isolation of offending organisms.

Adverse cognitive effects of high-fat diet in a murine model of sleep apnea are mediated by NADPH oxidase activity

Intermittent hypoxia (IH) during sleep, such as occurs in sleep apnea (SA), induces increased NADPH oxidase activation and deficits in hippocampal learning and memory. Similar to IH, high fat-refined carbohydrate diet (HFD), a frequent occurrence in patients with SA, can also induce similar oxidative stress and cognitive deficits under normoxic conditions, suggesting that excessive NADPH oxidase activity may underlie CNS dysfunction in both conditions. The effect of HFD and IH during the light period on two forms of spatial learning in the water maze as well as on markers of oxidative stress was assessed in male mice lacking NADPH oxidase activity (gp91phox⁻/Y) and wild-type littermates fed on HFD. On a standard place training task, gp91phox⁻/Y displayed normal learning, and was protected from the spatial learning deficits observed in wild-type littermates exposed to IH. Moreover, anxiety levels were increased in wild-type mice exposed to HFD and IH as compared to controls, while no changes emerged in gp91phox⁻/Y mice. Additionally, wild-type mice, but not gp91phox⁻/Y mice, had significantly elevated levels of malondialdehyde (MDA) and 8-hydroxydeoxyguanosine (8-OHdG) in hippocampal lysates following IH-HFD exposures. The cognitive deficits of obesity and westernized diets and those of sleep disorders that are characterized by IH during sleep are both mediated, at least in part, by excessive NADPH oxidase activity.

Extensively drug-resistant tuberculosis: experience at the Tuberculosis Research Centre, Chennai, India

Ten extensively drug-resistant tuberculosis (XDR-TB) patients were identified among 104 human immunodeficiency virus negative multidrug-resistant tuberculosis (MDR-TB) patients treated at the Tuberculosis Research Centre, Chennai, India, in two different cohorts between 1999-2003 and 2006-2007. They were managed with individualised treatment regimens. At the time of diagnosis of MDR-TB, one patient had XDR-TB and three had initial ofloxacin resistance. One patient who had had a lobectomy in addition to chemotherapy became bacteriologically negative, three died, three defaulted and the remaining three, who are bacteriologically positive, are still continuing treatment. Although based on a small number of patients, our results have not been encouraging.