Optic disc topography of normal Indian eyes: an assessment using optical coherence tomography

Purpose: To study the optic disc topographic measurements of normal Indian eyes using optical coherence tomography (OCT). Materials and Methods: One hundred and fifty eyes selected randomly from 150 normal Indian subjects of both sex and various age groups underwent optic disc imaging with the OCT using the fast optic disc protocol. Results: Mean +/- standard deviation of the optic disc topographic measurements were: disc area 2.63 +/- 0.55 mm 2 , cup area 0.87 +/- 0.45 mm 2 , neuroretinal rim area 1.78 +/- 0.55 mm 2 and cup to disc area ratio 0.33 +/- 0.15. There was no significant difference in the measurements between males and females. There was no significant correlation with respect to age and refractive errors ranging from -5.0 to +3.0 diopters of spherical equivalent. Conclusion: Our study provides a normative database for the various optic disc topographic measurements and its variations with age, sex and refractive error in normal Indian eyes using OCT.     

Assessing Walking and Cycling Environments in the Streets of Madrid: Comparing On-Field and Virtual Audits

Audit tools are useful for exploring the urban environment and its association with physical activity. Virtual auditing options are becoming increasingly available potentially reducing the resources needed to conduct these assessments. Only a few studies have explored the use of virtual audit tools. Our objective is to test if the Madrid Systematic Pedestrian and Cycling Environment Scan (M-SPACES) discriminates between areas with different urban forms and to validate virtual street auditing using M-SPACES. Three areas (N?=?500 street segments) were selected for variation in population density. M-SPACES was used to audit street segments physically and virtually (Google Street View) by two researchers in 2013–2014. For both physical and virtual audits, all analyzed features score significantly different by area (p?<?0.05). Most of the features showed substantial (ICC?=?0.6–0.8) or almost perfect (ICC?≥?0.8) agreement between virtual and physical audits, especially neighborhood permeability walking infrastructure, traffic safety, streetscape aesthetics, and destinations. Intra-rater agreement was generally acceptable (ICC?>?0.6). Inter-rater agreement was generally poor (ICC?<?0.4). Virtual auditing provides a valid and feasible way of measuring residential urban environments. Comprehensive auditor training may be needed to guarantee good inter-rater agreement.     

Ultra-Violet Light Emission from HPV-G Cells Irradiated with Low Let Radiation From 90Y; Consequences for Radiation Induced Bystander Effects

In this study, we aimed to establish the emission of UV photons when HPV-G cells and associated materials (such as the cell substrate and cell growth media) are exposed to low LET radiation. The potential role of UV photons in the secondary triggering of biological processes led us to hypothesize that the emission and absorption of photons at this wavelength explain some radiation induced “bystander effects” that have previously been thought to be chemically mediated. Cells were plated in Petri-dishes of two different sizes, having different thicknesses of polystyrene (PS) substrate, and were exposed to β-radiation from ⁹⁰Y produced by the McMaster Nuclear Reactor. UV measurements were performed using a single photon counting system employing an interference-type filter for selection of a narrow wavelength range, 340±5 nm, of photons. Exposure of the cell substrates (which were made of polystyrene) determined that UV photons were being emitted as a consequence of β particle irradiation of the Petri-dishes. For a tightly collimated β-particle beam exposure, we observed 167 photons in the detector per unit μCi in the shielded source for a 1.76 mm thick substrate and 158 photons/μCi for a 0.878 mm thick substrate. A unit μCi source activity was equivalent to an exposure to the substrate of 18 β-particles/cm² in this case. The presence of cells and medium in a Petri-dish was found to significantly increase (up to a maximum of 250%) the measured number of photons in a narrow band of wavelengths of 340±5 nm (i.e. UVA) as compared to the signal from an empty control Petri-dish. When coloured growth medium was added to the cells, it reduced the measured count rate, while the addition of transparent medium in equal volume increased the count rate, compared to cells alone. We attribute this to the fact that emission, scattering and absorption of light by cells and media are all variables in the experiment. Under collimated irradiation conditions, it was observed that increasing cell density in medium of fixed volume resulted in a decrease in the observed light output. This followed a roughly exponential decline. We suggest that this may be due to increased scattering at the cell boundary and absorption of the UV in the cells. We conclude that we have measured UVA emitted by cells, cell medium and cell substrates as a consequence of their irradiation by low LET β-particle radiation. We suggest that these secondary UV photons could lead to effects in non-targetted cells. Some effects that had previously been attributed to a chemically mediated “bystander effect” may in fact be due to secondary UV emission. Some radiation bystander effect studies may require re-interpretation as this phenomenon of UV emission is further investigated.     

A community-based study of early childhood sensory stimulation in home environment associated with growth and psychomotor development in Pakistan

Objectives

Sensory stimulation (SS) is a non-nutritional modifiable risk factor for early childhood development. We assessed SS in home environment and examined its influence on physical growth and psychomotor development (PD).

Methods

A cross-sectional study was conducted in 26 communities in Pakistan among children aged <3 (n = 1,219). They were assessed at home visits using (1) Bayley’s Infant Developmental Scale for PD, (2) home observation for measurement of the environment inventory for SS, (3) anthropometry and (4) socio-economic questionnaire.

Results

In rural homes, SS provided was lower as compared to urban counterparts (Adj mean diff: 4.47, 95 % CI 3.78, 5.16) and showed an association with stunting (Adj mean diff: ?1.30, 95 % CI ?1.93, ?0.66), and underweight (Adj mean diff: ?1.04, 95 % CI ?1.71, ?0.38) not explained by type of neighbourhood or socio-economic status. SS was associated with PD more than combined contribution of socio-economic status and rural–urban factors (Adj mean diff: 0.47, 95 % CI 0.30, 0.63).

Conclusions

SS in rural homes may be a significant factor influencing the child development. There is a need to corroborate these results by additional research for integration in health policy initiatives.     

Quality of case reports of adverse drug reactions with psychotropic drugs: a 25‐year review

Case reports of adverse reactions with psychotropic drugs can be useful in raising hypotheses, to be tested with more rigorous study designs. However such reports have significant methodological drawbacks, making it hard to determine causality. We undertook a systematic assessment of the quality of case reports and small case series published within Human Psychopharmacology over 25 years. For reports of adverse drug reactions, modified Bradford Hill criteria for causality (for consistency, strength, specificity, temporal relationship and plausibility) were used to ascertain the quality of the account. Reports which had been cited at least 10 times by December 2010 were examined in detail, to assess their overall contribution in extending understanding and influencing clinical practice. Of 40 reports of adverse drug reactions, only seven were sufficiently robust for confidence in probable or possible causality. Nine reports had been cited more than 10 times: the five most frequently cited reports of adverse drug reactions described movement disorders, suicidal thoughts and discontinuation symptoms with SSRIs: clinical relevance was high, but their quality was not markedly greater than less frequently cited reports. Nearly all reports of adverse drug reactions, published in a single journal over 25 years, were insufficiently robust to demonstrate probable causality. Reports that are cited frequently become influential because of their potential clinical relevance, rather than due to their methodological quality. Copyright © 2013 John Wiley & Sons, Ltd.     

Enhancing polysaccharide-mediated delivery of nucleic acids through functionalization with secondary and tertiary amines

Chitosan is a polysaccharide that has generated significant interest as a non-viral gene delivery vehicle due to its cationic and biocompatible characteristics. However, transfection efficiency of chitosan is significantly lower compared to other cationic gene delivery agents, e.g. polyethyleneimine (PEI), dendrimers or cationic lipids. This is primarily attributed to its minimal solubility and low buffering capacity at physiological pH leading to poor endosomal escape of the gene carrier and inefficient cytoplasmic decoupling of the complexed nucleic acid. Here we have developed an imidazole acetic acid (IAA)-modified chitosan to introduce secondary and tertiary amines to the polymer in order to improve its endosomal buffering and solubility. The modified polymer was characterized by ninhydrin and (1)H NMR assays for degree of modification, while buffering and solubility were analyzed by acid titration. Nanocomplex formation, studied at various polymer-nucleic acid ratios, showed an increase in particle zeta potential for chitosan-IAA, as well as an increase in the effective diameter. Up to 100-fold increase in transfection efficiency of pDNA was seen for chitosan-IAA as compared to native chitosan, nearly matching that of PEI. In addition, transfection of siRNA by the modified polymers showed efficient gene knockdown equivalent to commercially available siPORT Amines. Collectively, these results demonstrate the potential of the imidazole-grafted chitosan as a biocompatible and effective delivery vehicle for both pDNA and siRNA.     

Assessing posterior ocular structures in β-thalassemia minor

Purpose

The aim of this study was to investigate the effect of β-thalassemia minor on choroidal, macular, and peripapillary retinal nerve fiber layer thickness.

Methods

To form the sample, we recruited 40 patients with β-thalassemia minor and 44 healthy participants. We used spectral-domain optical coherence tomography to take all measurements of ocular thickness, as well as measured intraocular pressure, axial length, and central corneal thickness. We later analyzed correlations of hemoglobin levels with ocular parameters.

Results

A statistically significant difference emerged between patients with β-thalassemia minor and the healthy controls in terms of mean values of subfoveal, nasal, and temporal choroidal thickness (p = 0.001, p = 0.016, and p = 0.010, respectively). Except for central macular thickness, differences in paracentral macular thicknesses between the groups were also significant (superior: p < 0.001, inferior: p = 0.007, temporal: p = 0.001, and nasal: p = 0.005). Also, no statistically significant differences were noted for retinal nerve fiber layer thickness between two groups.

Conclusion

Mean values of subfoveal, nasal, temporal choroidal, and macular thickness for the four quadrants were significantly lower in patients with β-thalassemia minor than in healthy controls.

     

Immunomodulatory effects of fenugreek (Trigonella foenum graecum L.) extract in mice

Immunomodulatory activity of aqueous extract of Trigonella foenum graecum L., a widely used medicinal and dietary herb, was evaluated in male Swiss albino mice. Mice were treated with three doses of extract (50, 100 and 250 mg/kg body weight per os) for 10 days. Body weight, relative organ weight, cellularity of lymphoid organs, delayed type of hypersensitivity (DTH) response, plaque-forming cell (PFC) assay, haemagglutination titre (HT), quantitative haemolysis of SRBC (QHS) assay, phagocytosis, and lymphoproliferation were studied in various groups of animals. At doses of 50 and 100 mg/kg, a significant increase (p < 0.05) in relative organ weight of thymus was observed but there was no effect on kidney and spleen weights. Liver weight also increased significantly at doses of 100 and 250 mg/kg. However, no elevation in the levels of liver function test (LFT) enzymes was observed. As regards lymphoid organ cellularity, spleen recorded no significant increase at any dose, whereas cellularities of thymus and bone marrow were significantly increased. T. foenum graecum extract elicited a significant (p < 0.001) increase in the DTH response at doses of 50 and 100 mg/kg, but the change at higher dose of 250 mg/kg was not statistically significant. Humoral immunity as measured by PFC showed an elevated response at a dose of 100 mg/kg, but at 50 and 250 mg/kg, no significant effect was observed. In the HT test, plant extract also showed modulatory effect at all the doses. Plant extract elicited a significant increase in phagocytic index and phagocytic capacity of macrophages. Stimulatory response of plant extract was also observed in lymphoproliferation assay but the response was weak. Overall, T. foenum graecum showed a stimulatory effect on immune functions in mice. As it is used for a variety of medicinal purposes, its immunostimulatory effect, as reported in this study, strengthens the rationale of its use in several Ayurvedic and Unani drugs.     

International spread of major clones of methicillin resistant staphylococcus aureus: nosocomial endemicity of multi locus sequence type 239 in Saudi Arabia and Romania

Phenotypically identified methicillin resistant Staphylococcus aureus (MRSA) strains from several hospitals in Romania and Saudi Arabia (n = 103 and 68, respectively) were confirmed to be MRSA by mecA PCR and PBP-2' based latex agglutination. Subsequently, strains were differentiated at the sub-species level using pulsed field gel electrophoresis (PFGE) of SmaI DNA macro-restriction fragments. Comparison of the PFGE fingerprints identified major clusters of strains, persistently present in the various hospitals. Endemicity of certain strains was identified, amongst others one due to a particularly methicillin resistant type in the burn wound sector of the Romanian hospital. No PFGE-based overlap was found between the Saudi and Romanian strains. However, multi locus sequence typing (MLST), performed for 20% of all strains, revealed that genuine genetic similarity was obscured by the PFGE analysis. In both the Romanian and Saudi hospitals the renowned sequence type (ST) 239 was very over-represented. This was especially apparent in Saudi Arabia, where all strains except two shared the ST 239 genotype. This clonal type has previously been identified in a variety of other countries. Despite the MLST concordance, PFGE data indicate that ST 239 diversifies while maintaining its core genome intact. ST 80, another previously but less frequently identified clone, was introduced in 2000 in the Romanian institutes and persisted over the past 3 years as a frequent cause of infections in a surgical department. The successful MRSA types can acquire prominent positions in hospitals of previously low-endemicity MRSA status.