Predictors of visual outcome in post-fever retinitis: a retrospective analysis.

PURPOSE: To identify the predictors of final visual outcome in cases with post-fever retinitis (PFR). METHODS: This is a retrospective study of cases with diagnosis of post-fever retinitis. Colour fundus photograph and optical coherence tomography (OCT) parameters at presentation and final visit were analysed. Various factors at presentation [age, systemic illness, best-corrected visual acuity (BCVA), area of retinitis and hard exudates, OCT parameters], at final visit (OCT parameters) and the treatment modalities used were correlated with BCVA at final visit. RESULTS: Twenty-four eyes of 16 patients with PFR were included in the study. Median BCVA at presentation was 6/60 and at final visit was 6/9. By multiple linear regression after adjusting for other variables, for every 1 unit increase in height of subretinal fluid (SRF) at fovea at presentation, the value of final BCVA decreased by 0.001 unit. For every 1 unit increase in extent of ellipsoid zone (EZ) loss and subfoveal deposit height, the value of final BCVA decreased by 0.0001 unit and 0.004 unit, respectively. The baseline OCT parameters that had negative correlation with final BCVA included central macular thickness (r: - 0.5182, p: 0.02), maximum SRF height (r: - 0.5539, p < 0.01) and SRF height at fovea (r: - 0.582, p < 0.01). The OCT parameters at final visit which had a negative correlation with final BCVA included disorganisation of retinal inner layers (DRIL) within 1000 microns from centre of fovea (r: - 0.6494, p < 0.01), height of subfoveal deposit (r: - 0.7627, p < 0.01), horizontal extent of subfoveal deposit (r: - 0.6695, p < 0.01) and extent of EZ loss (r: - 0.8216, p < 0.01). CONCLUSION: Height of SRF at presentation, extent of EZ loss and subfoveal deposit height at final visit were associated with poor final BCVA in PFR.

Probing the activity of a recombinant Zn2+ -transporting P-type ATPase.

P-type ATPase proteins maintain cellular homeostasis and uphold critical concentration gradients by ATP-driven ion transport across biological membranes. Characterization of single-cycle dynamics by time-resolved X-ray scattering techniques in solution could resolve structural intermediates not amendable to for example crystallization or cryo-electron microscopy sample preparation. To pave way for such time-resolved experiments, we used biochemical activity measurements, Attenuated Total Reflectance (ATR) and time-dependent Fourier-Transform Infra-Red (FTIR) spectroscopy to identify optimal conditions for activating a Zn2+ -transporting Type-I ATPase from Shigella sonnei (ssZntA) at high protein concentration using caged ATP. The highest total activity was observed at a protein concentration of 25 mg/mL, at 310 K, pH 7, and required the presence of 20% (v/v) glycerol as stabilizing agent. Neither the presence of caged ATP nor increasing lipid-to-protein ratio affected the hydrolysis activity significantly. This work also paves way for characterization of recombinant metal-transporting (Type-I) ATPase mutants with medical relevance.

Mechanistic studies on the biosorption of Pb(II) by Pseudomonas aeruginosa.

The biosorption of Pb(II) ions from aqueous solution has been studied using both the intact and thermolyzed cells of Pseudomonas aeruginosa. Further, the role of the major cell wall components, namely DNA, protein, polysaccharide, and lipid, in Pb(II) binding has been assessed using an enzymatic treatment method. The Pb(II) bioremediation capability of P. aeruginosa cells has been investigated by varying the parameters of pH, time of interaction, amount of biomass, and concentration of Pb(II). The complete bioremoval of Pb(II) using intact cells has been achieved for an initial Pb(II) concentration of 12.4 mg L-1 at pH 6.2 and temperature 29 ± 1 °C. The biosorption isotherm follows Langmuirian behavior with a Gibbs free energy of -30.7 kJ mol-1, indicative of chemisorption. The biosorption kinetics is consistent with a pseudo-second-order model. The possible Pb(II) binding mechanisms of P. aeruginosa cells are discussed based on characterization using zeta potential measurements, Fourier transform infra-red spectroscopy, and energy dispersive X-ray spectroscopy. The results confirm that among the major cell wall components studied, polysaccharide shows the highest contribution towards Pb(II) binding, followed by DNA, lipid, and protein. Similar studies using thermolyzed cells show higher Pb(II) uptake compared to the intact cells both before and after enzymatic treatment.

Evaluation of agreement in macular vascular density measured by different protocols: 4.5 mm × 4.5 mm and 6 mm × 6 mm.

PURPOSE: To evaluate the agreement in the macular vascular density (MVD) measured by two protocols: 4.5 mm × 4.5 mm and 6 mm × 6 mm. DESIGN: Cross-sectional observational study. METHODS: Healthy volunteers between the age group of 19 and 39 years were recruited. Topcon DRI OCT Triton plus (Topcon Corporation, Tokyo, Japan) was used to acquire the fovea-centered optical coherence tomography angiography (OCTA) image using two protocols: 4.5 mm × 4.5 mm and 6 mm × 6 mm. MVD was measured by the manufacturer software in the superficial capillary plexus slab in five regions: central, superior, nasal, inferior, and temporal subfields of early treatment diabetic retinopathy study grid in each protocol. RESULTS: The study included 79 eyes of 40 healthy volunteers. The difference in the mean MVD between two protocols was 3.84% in right eye and 4.2% in left eye in central subfield, 0.93% in right eye and 1.13% in left eye in superior subfield, 0.06% in right eye and 1.45% in left eye in nasal subfield, 1.65% in right eye and 0.7% in left eye in inferior subfield, 0.4% in right eye and 0.54% in left eye in temporal subfield. The measurements were significantly higher in 6 mm × 6 mm in central subfield in both the eyes and in nasal field in the left eye. Whereas, the measurements were significantly higher in 4.5 mm × 4.5 mm in superior and inferior subfield in both the eyes and in temporal subfield in the left eye. CONCLUSION: The protocols should not be used interchangeably and it is necessary to include recommendation of the field of view to measure MVD while standardizing OCTA reporting.

Volume measurement of the vitrectomised eye and its applications in practice.

PURPOSE: To estimate the vitreous cavity replacement volume after pars plana vitrectomy and analyze its correlation with axial length and refractive error. METHODS: Observational cross-sectional study on 103 eyes undergoing vitrectomy. Fluid-air exchange was performed using a soft-tip cannula connected to a PVC tubing, the distal end of which opened into a 10-cc syringe without the plunger. The collected fluid was measured (and correction factors applied) to estimate the vitreous cavity volume. RESULTS: The mean axial length of 103 eyes was 23.43 ± 1.54 mm. The mean vitreous cavity volume was 4.46 ± 0.83 mL (2.8-8.1 mL). There was a strong positive correlation between axial length and vitreous volume, which was stronger for pseudophakic and aphakic groups than for phakic groups. CONCLUSION: Accurate assessment of vitreous cavity volume can enable precise quantification of tamponade, intravitreal drugs, and intravitreal chemotherapeutic agents. This will allow better surgical outcomes, decreased toxicity, and increased cost-effectiveness due to lesser wastage. OBJECTIVE: To estimate the vitreous cavity replacement volume after pars plana vitrectomy and analyze its correlation with axial length and refractive error.

Laser photocoagulation of a hypofluorescent perifoveal exudative vascular anomalous complex/capillary macroaneurysm.

PURPOSE: To report successful treatment of a hypofluorescent perifoveal exudative vascular anomalous complex (PEVAC)/capillary macroaneurysm. CASE DESCRIPTION: A 63 year old healthy gentleman had a perifoveal isolated aneurysmal lesion with white rim. Optical coherence tomography (OCT) showed cystoid macular edema (CME) with neurosensory detachment. The aneurysmal lesion was seen in the inner retina as a hyperreflective intraretinal structure with a heterogenous lumen suggestive of PEVAC/capillary macroaneurysm. OCT angiography showed a capillary loop and a slightly hyperreflective lesion at the tip of the loop in the superficial capillary plexus slab. Minimal reduction in edema was noted following one dose of intravitreal triamcinolone (2 mg). Fundus fluorescein angiography performed at 6 weeks demonstrated the capillary loop, but the aneurysmal lesion remained hypofluorescent with no definite leak in the late phase. Few perifoveal microaneurysms were seen in both the eyes. Six weeks later, focal laser photocoagulation of the aneurysmal lesion was performed, which resulted in complete resolution of macular edema at 1 month. There was no recurrence of macular edema till his recent follow up, which is 4 month post laser. DISCUSSION: PEVAC is typically described as unifocal lesion and is not associated with other retinal vascular abnormalities. But in this case, in addition to the lesion, perifoveal microaneurysms were seen in both the eyes. Despite the absence of leak on fundus fluorescein angiography, targeted focal laser photocoagulation resulted in complete resolution of macular edema at 1 month. CONCLUSION: Laser photocoagulation would be helpful even in hypofluorescent PEVAC/capillary macroaneurysms.

Targeted laser photocoagulation of larger capillary aneurysms with rim in diabetic macular edema.

This is a retrospective series of five eyes of four cases with diabetic macular edema (DME) secondary to large capillary aneurysms. Larger capillary aneurysms were identified noninvasively based on the presence of white rim in color photograph. On optical coherence tomography (OCT), the larger capillary aneurysms were seen as vertically oval structures with heterogeneous lumen and hyperreflective margin. Two of the four eyes were treated with intravitreal therapy with poor response before considering laser photocoagulation. In one eye, laser photocoagulation was considered as primary therapy in view of the poor response to intravitreal therapy in the fellow eye. In one eye, intravitreal steroid with prompt laser was considered. In one eye, laser was considered as primary therapy. Complete obliteration of the capillary lumen was noted on OCT in all the five eyes after laser photocoagulation. Complete resolution of macular edema was noted in all the five eyes with no recurrence over a follow-up period of 4-18 months. DME secondary to larger capillary aneurysms responds well to targeted laser photocoagulation. These larger capillary aneurysms can be identified on clinical examination and color photograph by the presence of white rim and can be confirmed on OCT.

Analysis of orbitofacial anthropometry in children with pseudostrabismus.

AIM: The aim of the study was to analyze orbitofacial anthropometric parameters such as inner and outer canthal distances (ICD and OCD), palpebral fissure length (PFL), interpupillary distance (IPD), and canthal index (CI) in children with pseudostrabismus and to compare the measured IPD (mIPD) with calculated IPD (cIPD). MATERIALS AND METHODS: This was a prospective study of sixty children (6 months-18 years) with pseudostrabismus. ICD, OCD, PFL, and IPD were measured by digital Vernier caliper. The formula used was cIPD: 0.21+0.24 ICD+0.58°CD for males and 1.4+0.31 ICD+0.41°CD for females. Values measured by caliper were compared with that calculated by the formula. The formula used was CI: ICD × 100/OCD. Data were analyzed statistically. RESULTS: The mean age was 6.66 ± 3.57 years. Telecanthus was the most common finding (55%). The mean ICD and OCD in males were 30.89 ± 3.33 mm and 87.96 ± 8.09 mm and in females were 30.91 ± 3.05 and 86.22 ± 6.81 mm, respectively. The mean right eye PFL in males was 28.53 ± 2.63 mm and in females was 27.66 ± 2.22 mm and left eye PFL in males was 28.53 mm ± 2.63 and in females was 27.66 ± 2.22 mm. CI in males was 35.10 ± 1.65 and in females was 35.84 ± 1.71. Mean mIPD and cIPD: male - 55.37 ± 4.75 mm and 58.56 ± 5.34 mm, female - 53.32 ± 4.74 mm and 46.26 ± 3.71 mm. A good agreement was found between mIPD and cIPD. CONCLUSION: This study helps in documenting the anthropometric pattern of the orbitofacial parameters in children with pseudostrabismus which can act as reference data. This helps in the management of orbitofacial, craniofacial syndromes/deformities and lid reconstructive surgeries in retaining ethnical features and obtaining better function. In children's spectacle frame 1 and lens making, where measuring IPD is difficult, cIPD can be a simple alternative.

Irrigation with Bupivacaine at the Surgical Bed for Postoperative Shoulder Tip and Abdominal Pain Relief after Laparoscopic Cholecystectomy.

Gallstones in western countries are primarily composed of cholesterol. However, mixed or pigment stones, which contain a higher proportion of bilirubin, are more frequently seen in developing nations and Asia than in western countries. Abdominal and shoulder tip pains (STPs) are common complaints following the standard laparoscopic cholecystectomy procedure. To date, all pain management modalities have proven variable outcomes. This prospective randomized study included 82 patients who underwent elective laparoscopic cholecystectomy. The control group received 20 mL of normal saline, whereas the study group received a 20-mL instillation of 0.5% bupivacaine at the gallbladder bed after surgical resection. The Visual Analog Scale (VAS) was used to analyze abdominal pain and STP. The mean age ranged from 20 to 80 years. Abdominal VAS at 6, 12, 18, 24, 30, 36, and 48 hours were statistically insignificant. The majority were discharged on postoperative day 1 (32 studies, 37 control). Follow-up VAS after 1 week for STP VAS and abdominal pain VAS in both groups were statistically insignificant. Even with small numbers of a well-conducted randomized trial, we demonstrated that bupivacaine irrigation at the gallbladder bedpost laparoscopic cholecystectomy does not affect pain relief.

Presence and development of strabismus in children with telecanthus, epicanthus and hypertelorism.

Purpose: To study the presence and development of strabismus in children with telecanthus, epicanthus, and hypertelorism. Methods: This is a prospective, longitudinal, and observational study. Sixty children aged between 6 months and 18 years with telecanthus, epicanthus, and hypertelorism in isolation or in combination were recruited. A detailed analysis of the history, determination of best corrected visual acuity, complete evaluation of strabismus, and ocular examination were carried out. The presence of telecanthus, epicanthus, and hypertelorism and associated strabismus, if any, was noted. All children were followed up for a minimum and maximum period of 12 and 18 months, respectively, to analyze the strabismus (previously present) and for detection of strabismus in those who did not have. The data were analyzed descriptively with mean and standard deviation. Chi square test and Fishers exact test were used to analyze the data between the groups. A P value less than 0.05 was considered to be statistically significant. Results: Telecanthus was the most common lid feature (55%). At baseline, ten (16.66%) children had strabismus (six: esotropia; four: exotropia). Two (3.33%) children underwent surgery. One child developed exotropia at the third follow-up (18 months). At the end of the study, 11 (18.33%) children had strabismus. No significant association was seen between lid characteristics and the type of strabismus. Conclusion: Children with telecanthus, epicanthus, and hypertelorism in isolation or in combination may or may not have associated strabismus. These features can pose difficulty in strabismus diagnosis, which mandates a careful examination, especially in younger age groups and small-angle strabismus. On the other hand, children without strabismus need longer follow-up to detect the development of strabismus and to initiate further management at the earliest.

Ocular Injury due to Arecanut: A Unique Occupational Hazard in Central Karnataka.

PURPOSE: To evaluate the ocular manifestations and visual outcomes of ocular injury by arecanut. METHODS: We analysed cases with ocular injury by arecanut from August 2018 to December 2019, retrospectively. Mode of injury, visual acuity and ocular manifestations of trauma were recorded. RESULTS: Out of the 40 cases, closed globe injuries were seen in 97.5% of cases. All the injuries were due to the direct impact of arecanut during harvesting. The mean age was 45.15 ± 12.84 years. The mean best-corrected visual acuity (BCVA) at presentation was 20/40. A significant number of cases (35%) required surgical intervention. Mean BCVA at final follow-up was 20/30 but 16.66% of cases had BCVA of <20/60 even after definitive therapy. CONCLUSION: Ocular trauma due to arecanut is an important and preventable cause of visual impairment in central Karnataka. Modifications in harvesting technique would prevent ocular injuries.

Characterization of a mouse recombination hot spot locus encoding a novel non-protein-coding RNA.

Our current knowledge of recombination hot spot activity in mammalian systems implicates a role for both the primary DNA sequence and the nature of the chromatin domain around it. In mice, the only recombination hot spots mapped to date have been confined to a cluster within the major histocompatibility complex (MHC) region. We present a high resolution analysis of a new recombination hot spot in the mouse genome which maps to mouse chromosome 8 C-D. Haplotype diversity analysis across 40 different strains of mice has enabled us to map recombination breakpoints to a 1-kb interval. This hot spot has a recombination intensity that is 10- to 100-fold above the genome average and has a mean gene conversion tract length of 371 bp. This meiotically active locus happens to be flanked by a transcribed region encoding a non-protein-coding RNA polymerase II transcript and the previously characterized repair site. Many of the primary DNA sequence features that have been reported for the mouse MHC hot spots are also shared by this hot spot locus and in addition, along with three other MHC hot spot loci, we show a new parallel feature of association of the crossover sites with the nuclear matrix.

Formation of an oxo-radical of peroxovanadate during reduction of diperoxovanadate with vanadyl sulfate or ferrous sulfate.

Formation of oxygen radicals during reduction of H(2)O(2) or diperoxovanadate with vanadyl sulfate or ferrous sulfate was indicated by the 1:2:2:1 electron spin resonance (ESR) signals of the DMPO adduct typical of standard ()OH radical. Signals derived from diperoxovanadate remained unchanged in the presence of ethanol in contrast to those from H(2)O(2). This gave the clue that they represent a different radical, possibly (*)OV(O(2))(2+), formed on breaking a peroxo-bridge of diperoxovanadate complex. The above reaction mixtures evolved dioxygen or, when NADH was present, oxidized it rapidly which was accompanied by consumption of dioxygen. Operation of a cycle of peroxovanadates including this new radical is suggested to explain these redox activities both with vanadyl and ferrous sulfates. It can be triggered by ferrous ions released from cellular stores in the presence of catalytic amounts of peroxovanadates.

NADH oxidation is stimulated by an intermediate formed during vanadyl-H2O2 interaction.

Addition of NADH decreased the oxygen release that accompanied oxidation of vanadyl by H2O2. The added NADH was oxidized rapidly and oxygen was consumed with a stoichiometry of 1:1 for NADH/O2. Small concentrations of H2O2 were sufficient to trigger this oxygen-consuming NADH oxidation which terminated on exhaustion of either NADH or vanadyl. The oxidation of NADH increased proportionately with concentration of NADH and vanadyl. The oxidation products of vanadyl were found to be a mixture of vanadate oligomers and peroxovanadates. The reaction was sensitive to catalase, SOD, histidine and EDTA. Using ESR spectroscopy with DMPO as the spin trap, an adduct corresponding to DMPO-OH was detected in these phosphate-buffered reaction mixtures. Participation of hydroxyl radicals in NADH oxidation, however, seems doubtful because even high concentrations of ethanol, methanol, mannitol, formate and benzoate, known to scavenge these radicals, did not block the reaction. The results indicate that peroxovanadate intermediates formed during vanadyl oxidation by H2O2 play a key role in the oxidation of NADH.

Diperoxovanadate participates in peroxidation reactions of H2O2 in presence of abundant catalase.

Vanadate forms a stable complex with H2O2 at pH 7.0 in competition with catalase and the product, diperoxovanadate, resists scavenger action of catalase. Diperoxovanadate can act as a substrate in a H2O2-user reaction, horseradish peroxidase and can take the place of H2O2 far more effectively in oxidatively inactivating glyceraldehyde-3-phosphate dehydrogenase. By forming peroxo-complexes vanadate can provide a way of preserving cellular H2O2 in presence of abundant catalase and make it available for its functions.

Absence of GABRA1 Ala322Asp mutation in juvenile myoclonic epilepsy families from India.

An Ala322Asp mutation in the GABRA1 gene was recently reported to be responsible for causing the autosomal dominant (AD) form of juvenile myoclonic epilepsy (JME) in a French-Canadian family. To study if JME families from India exhibiting the AD mode of inheritance carry the Ala322Asp mutation, we examined 35 unrelated JME-affected individuals from such families for the Ala322Asp mutation in GABRA1. Ala322Asp mutation was not observed in any of these JME-affected individuals, suggesting that this mutation is unlikely to be a predominant mutation involved in causation of epilepsy. To evaluate the possibility of other mutation(s) in and around GABRA1 that may predispose to JME, we compared the allele frequencies at two marker loci, D5S2118 and D5S422, flanking GABRA1, in probands and 100 matched population controls. One of the allele frequencies at D5S422 shows a significant difference between the cases and controls (chi-square = 11.44, d.f. = 1, P = 0.0007), suggesting genetic association between JME and genes located in the proximity of the DNA marker.

Microbially induced selective flotation of sphalerite from galena using mineral-adapted strains of Bacillus megaterium.

The selective flotation of sphalerite from a sphalerite-galena mineral mixture has been achieved using cells and extracellular secretions of Bacillus megaterium after adaptation to the chosen minerals. The extracellular secretions obtained after thermolysis of bacterial cells adapted to sphalerite yield the highest flotation recovery of sphalerite with a selectivity index value of 24.5, in comparison to the other cellular and extra-cellular bio-reagents studied. The protein profile for the unadapted and mineral-adapted cells has been found to differ distinctly, attesting to variation in the yield and nature of extra-cellular polymeric substances (EPS). The changes induced in the bacterial cell wall components after adaptation to sphalerite or galena with respect to the contents of phosphate, uronic acid and acetylated sugars of B. megaterium have been quantified. The role of the dissolved metal ions from the minerals as well as that of the constituents of extracellular secretions in modulating the surface charge of the bacterial cells as well as the minerals under study has been confirmed using various enzymatic treatments of the bacterial cells. It has been demonstrated that the induction of additional molecular weight protein fractions as well as the higher amount of extracellular proteins and phosphate secreted after adaptation to sphalerite vis-à-vis galena are contributory factors for the selective separation of sphalerite from galena.