Detection of novel coupled mutations in the katG gene (His276Met, Gln295His and Ser315Thr) in a multidrug-resistant Mycobacterium tuberculosis strain from Chennai, India, and insight into the molecular mechanism of isoniazid resistance using structural bioinformatics approaches.

This study reports on the structural basis of drug resistance targeting the katG gene in a multidrug-resistant Mycobacterium tuberculosis (MDR-TB) strain with two novel mutations (His276Met and Gln295His) in addition to the most commonly reported mutation (Ser315Thr). A structural bioinformatics approach was used to predict the structure of the mutant KatG enzyme (MT). Subsequent molecular dynamics and docking studies were performed to explain the mechanism of isoniazid (INH) resistance.

Influence of glycosylated hemoglobin on sight-threatening diabetic retinopathy: a population-based study.

Aim: To evaluate the role of glycosylated hemoglobin (HbA1c) on the occurrence of sight-threatening diabetic retinopathy (STDR) in urban Chennai, Tamil Nadu, India.

Methods: A total of 5999 individuals were enumerated from the Chennai metropolis. Of these, 1414 subjects with diabetes were included for data analysis in the study.

Laser photocoagulation (810 nm diode) for threshold retinopathy of prematurity: a prospective randomized pilot study of treatment to ridge and avascular retina versus avascular retina alone.

The purpose of this study was to compare the structural outcome of laser treatment to avascular retina and ridge versus laser treatment to avascular retina alone in cases with threshold retinopathy of prematurity (ROP). A prospective, randomized, interventional, comparative study of consecutive cases referred to a single tertiary center was considered here. 50 infants with bilateral symmetrical threshold ROP were recruited into this study over a period of 3 years.

Toxicogenomics of nanoparticulate delivery of etoposide: potential impact on nanotechnology in retinoblastoma therapy.

To develop a suitable formulation with high entrapment efficiency, etoposide-loaded poly(lactide--glycolide) nanoparticles (NPs) were formulated by single emulsion-solvent evaporation method by changing different formulation parameters such as drug loading, choice of organic solvent and percentage of emulsifier polyvinyl alcohol. The NPs showed higher entrapment efficiency, ~86% (with 15% (/) drug loading). The physicochemical parameters revealed smooth topology with size range (240-320 nm), a negative zeta potential (~19 mV) and in vitro sustained-release activity (~60% drug release in 40 days).

Management of complications in glaucoma surgery.

Surgical option for glaucoma is considered when other modalities are not working out to keep the intraocular pressure under control. Since the surgical procedures for glaucoma disrupt the integrity of the globe, they are known to produce various complications. Some of those complications can be vision-threatening.

Clinico-pathological correlations of fatty acid synthase expression in retinoblastoma: an Indian cohort study.

Retinoblastoma (RB), the most common intra-ocular malignancy in children under 5 years of age, has an estimated incidence of about 2000 a year in India, where most cases are in advanced stage at the time of diagnosis. Newer therapeutic approaches would reduce the morbidity of chemotherapy in children with RB. Fatty Acid Synthase (FASN), a lipogenic multi-enzyme complex, is minimally expressed in normal human tissues and over expressed in many cancers, making it an attractive target for cancer therapy.

"pp65 antigenemia and real time polymerase chain reaction (PCR) based-study to determine the prevalence of human cytomegalovirus (HCMV) in kidney donors and recipients with follow-up studies".

Background: The present study was undertaken to determine the rate of occurrence of Human cytomegalovirus (HCMV) among kidney transplant recipients and donors by application of direct detection methods and to understand HCMV infection/disease development among transplanted patients as a prospective study.

Results: Peripheral blood samples collected from 76 kidney donors and 76 recipients from September 2007 to August 2009 were subjected to pp65 antigenemia and Quantitative real-time PCR (qRT-PCR) assays. Data were analyzed under Group A, B and C.

Ocular aberrations after wavefront optimized LASIK for myopia.

Purpose: To study the change in ocular aberrations after wavefront optimized (WFO) laser in situ keratomileusis (Lasik) for correction of myopia and to analyze causative factors that may influence them.

Materials And Methods: This was a prospective case series. WFO Lasik was performed for the correction of myopia, using the hansatome (Bausch and Lomb) microkeratome to create the flap and the Allegretto laser (Wavelight Technologie) to perform the ablation.

Endophthalmitis in eyes presenting with orbital signs: a case-control study.

Purpose: The purpose of this study was to assess the clinical profile and treatment outcomes in eyes with endophthalmitis presenting with orbital signs.

Methods: A case-control study of 24 eyes with endophthalmitis and orbital signs at presentation (defined as ocular motility restriction and/or presence of " inverted perpendicular" sign on ultrasonography) was conducted between January 2000 and December 2006. The control group was constituted of 40 age- and sex-matched eyes with endophthalmitis presenting without orbital signs.

Tear ascorbic acid levels and the total antioxidant status in contact lens wearers: a pilot study.

Aims: The tear ascorbate owing to its high concentration, functions as an effective antioxidant against the oxidative damage of cornea. Contact lens wearers (CLW) are prone to oxidative stress due to the lens-induced hypoxic conditions. A pilot study was done to compare the tear ascorbic acid level and the total antioxidant capacity give as in normal and CLW.

Functional and anatomical outcomes after primary lens-sparing pars plana vitrectomy for Stage 4 retinopathy of prematurity.

Background: While lens-sacrificing vitrectomy is the standard approach to manage Stage 5 retinopathy of prematurity (ROP), scleral buckling has been used to manage some cases of Stage 4. Lens-sparing vitrectomy was popularized by Maguire and Trese in selected cases of Stage 4 disease.

Purpose: To assess the functional and visual outcomes after primary lens-sparing pars plana vitrectomy for Stage 4 ROP.

Lower threshold estimates at the onset of automated perimetry causing artefacts in perimetrically naive subjects.

Reduction in the threshold value of the primary points resulting in depressed points on the pattern deviation plot of Humphrey visual fields was observed in a series of four perimetrically naive subjects. The defect disappeared on repeated testing. This primary point defect could be attributed to the patient's poor understanding of the test, response bias or poor instruction by the perimetrist.

Expression of p63 and p73 in retinoblastoma: a clinicopathological correlation study.

The aim of the study was to explore the expression profile of p63, p73 and their delta isoforms in the retinoblastoma tumor samples and to correlate with clinicopathological parameters. Immunohistochemistry was performed for p63, delta p63, p73 and delta p73 on the archival paraffin sections of retinoblastoma and correlated with clinicopathological features. Western blotting was performed to confirm immunoreactivity results.

The results of treatment of anisomyopic and anisohypermetropic amblyopia.

Purpose: To analyze the results of treatment of anisomyopic and anisohypermetropic amblyopia comparing full-time and part-time occlusion.

Methods: Retrospective analysis of case records of 100 patients of anisometropic amblyopia was carried out. Age, visual acuity, cycloplegic refraction, response, and compliance to treatment were recorded.

Physicians, pharmacists, and people with diabetes in India.

Objective: The present study was undertaken to elucidate the most frequently visited health care provider by the population attending a tertiary eye care hospital in South India.

Methods: A trained observer administered the questionnaire to 150 literate subjects aged above 30 years. Data collection included factors such as age, gender, single-index socioeconomic status (monthly income), presence of diabetes, and the name of the health care provider, including the number of times he or she was visited in the last 1 and 6 months.

Polymerase chain reaction in intraocular inflammation.

Polymerase chain reaction (PCR) is a technique involving enzymatic amplification of nucleic acid sequences in repeated cycles of denaturation, oligonucleotide annealing and DNA polymerase extension. It is a powerful molecular biologic tool that allows the rapid production of analytic quantities of DNA from small amounts of starting material. PCR can be performed on nearly any ocular specimen or biopsy.

Mycophenolate mofetil therapy in uveitis: analysis of eight cases in a tertiary ophthalmic care centre in India.

Mycophenolate mofetil (MMF) is a relatively new immunomodulatory agent. The experience of MMF in inflammatory eye diseases is limited to a few case series. We report our experience of MMF in eight patients with uveitis.

Use of intravitreal injection of triamcinolone acetonide in the treatment of age-related macular degeneration.

Age-related macular degeneration (AMD) is now considered an important and leading cause of blindness among elderly patients in developed and developing countries. AMD has two forms, dry and wet; both can lead to visual loss. However, occurrence of subfoveal choroidal neovascular (CNV) membrane in the wet form results in severe visual impairment.

Population norms for frequency doubling perimetry with uncorrected refractive error.

Purpose: To compare the effect of uncorrected refractive error on threshold estimation using frequency doubling perimetry (FDP) full-threshold N-30 with emmetropia among normal subjects.

Methods: One thousand two hundred ninety-nine subjects were enrolled from the Chennai Glaucoma Study, a population-based glaucoma prevalence study. Subjects underwent a comprehensive eye examination including the FDP full-threshold N-30 test.

Cripto-1 expression in uveal melanoma: an immunohistochemical study.

Human Cripto, the founder member of the epidermal growth factor-Cripto-FRL1-Cryptic (EGF-CFC) family, plays an important role during early embryonic development and in particular in carcinogenesis and the development of cancer metastases. Cripto-1 is over-expressed in most cancers, but is absent or only weakly expressed in normal cells. For this reason, Cripto-1 could be of potential value in the targeted treatment.

Hyperhomocysteinemia and low methionine stress are risk factors for central retinal venous occlusion in an Indian population.

Purpose: The underlying cause of disturbed homocysteine metabolism is incompletely understood in young persons with central retinal vein occlusion (CRVO) with mild hyperhomocysteinemia (HHcys) and no other systemic disease in India. A 2-year prospective study was undertaken to determine whether HHcys is a risk factor for CRVO in an Indian population.

Method: The prevalence of fasting HHcys was evaluated in a consecutive series of 29 patients with CRVO (mean age, 30 +/- 6 years) along with 57 age- and sex-matched control subjects (healthy subjects, mean age 27 +/- 5 years).