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Purpose: To determine the correlation between functional parameters and optical coherence tomography (OCT) features in patients of idiopathic intracranial hypertension (IIH). Methods: A prospective observational study in early and established cases of papilledema in IIH presenting from December 2017 to February 2019. Functional parameters (visual acuity, contrast sensitivity, mean deviation, VER, and MfERG) and structural parameters (RNFL, GCL?IPL, and optic disc height) were measured at baseline and every 6 weeks for 6 months. Results: At baseline, average RNFL had a moderate negative correlation with mean deviation (r = ?0.45; P = 0.0007) and a positive correlation with logMAR visual acuity (r = 0.18; P = 0.17). On the contrary, baseline GCL and logMAR visual acuity had a negative correlation (r = ?0.4, P = 0.02). Optic disc height (ODH) had a negative correlation with visual field mean deviation (r = ?0.046; P = 0.0005). At 6 months, ODH and GCL?IPL complex had a statistically significant correlation with functional parameters. However, RNFL values did not show any significant correlation with any of the functional parameters. Baseline GCL?IPL and optic disc height values had a moderate and significant correlation with final functional parameters. However, RNFL did not show any correlation with final functional parameters. Correlation between GCL?IPL thickness at 6 weeks and final functional parameters were stronger than that with baseline GCL values. Conclusion: In the setting of severe papilledema, RNFL can misguide the prognosis. GCL?IPL can be a valuable tool for an objective evaluation of the integrity of the optic nerve in IIH and ODH may be used as an alternative or in combination with GCL?IPL in these cases.
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We report studies on loss of heme at or below pH 3.0 from two clinically important hemoglobin variants, HbE and HbS, in the presence and absence of phopholipid membranes. The kinetics of heme loss has been studied at pH 3.0 to simulate the same at a faster rate than at physiological pH, for spectroscopic investigation. Results obtained from the study clearly establish the probable fate of the lost heme to partition into the phospholipid bilayer independent of the pH range. This is also of particular importance to membranes containing the aminophospholipid and cholesterol which are predominantly localized in the inner leaflet of erythrocytes. Absorption measurements indicated such loss of heme when the Soret peak at 415 nm blue-shifted to 380 nm at pH 3.0. The extent of this blue shift decreased from 35 nm to ~15 nm in the presence of small unilammelar vesicles of both dimyristoyl- and dioleoyl-based phosphatidylcholine and phosphatidylethanolamine, indicating partitioning of the released heme in the membrane bilayer. The kinetics of heme loss was faster from HbE than HbA and HbS, obeying first-order reaction kinetics. Released heme could be involved in the premature destruction of erythrocytes in hemoglobin disorders.
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Background & objectives: Bacillus cereus is one of the pathogens responsible for human diarrhoea, mainly due to consumption of contaminated food. The present study was undertaken to determine the occurrence of B. cereus among diarrhoeal patients and its phenotypic and genetic characteristics that determine the virulence and clonal features. Methods: Stool specimens were collected for two years from acute diarrhoeal patients attending the two referral hospitals in Kolkata. Presence of virulence genes in B. cereus was determined by PCR. Clonality was assessed by pulsed-field gel analysis (PFGE) by restriction digestion with SmaI and NotI enzymes. Enterotoxins were detected by haemolysin assay and using BCET-RPLA kit. Invasion assay was done on Hep-2 cell line. Antimicrobial susceptibility was tested by disc diffusion method. Results: B. cereus was identified in 54 (3.5%) of the 1536 diarrhoeal cases studied. Majority of the isolates were susceptible to many antibiotics but showed resistant to amoxyclav and cephalosporins. Six genes covering the two different enterotoxic complexes determining the pathogenicity of B. cereus have been characterized by PCR. The nhe genes were detected in a higher proportion than hbl. Except in two, clonal diversity was noticed among 21 B. cereus isolates. Haemolytic enterotoxin was detected in 76 per cent of the isolates. Majority of the isolates (67%) produced in vitro enterotoxin (BCET) confirming its involvement in the infection. Interpretation & conclusions: Though the presence of B. cereus was not high in patients with diarrhoea, several virulence factors confirm their association with diarrhoea. Distinct clonality was identified in majority of the isolates indicating their origin from different sources.