The TRPV5/6 calcium channels contain multiple calmodulin binding sites with differential binding properties

The epithelial Ca2+ channels TRPV5/6 (transient receptor potential vanilloid 5/6) are thoroughly regulated in order to fine-tune the amount of Ca2+ reabsorption. Calmodulin has been shown to be involved into calcium-dependent inactivation of TRPV5/6 channels by binding directly to the distal C-terminal fragment of the channels (de Groot et al. in Mol Cell Biol 31:2845–2853, 12). Here, we investigate this binding in detail and find significant differences between TRPV5 and TRPV6. We also identify and characterize in vitro four other CaM binding fragments of TRPV5/6, which likely are also involved in TRPV5/6 channel regulation. The five CaM binding sites display diversity in binding modes, binding stoichiometries and binding affinities, which may fine-tune the response of the channels to varying Ca2+-concentrations

High Cooperativity of the SV40 Major Capsid Protein VP1 in Virus Assembly

SV40 is a small, non enveloped DNA virus with an icosahedral capsid of 45 nm. The outer shell is composed of pentamers of the major capsid protein, VP1, linked via their flexible carboxy-terminal arms. Its morphogenesis occurs by assembly of capsomers around the viral minichromosome. However the steps leading to the formation of mature virus are poorly understood. Intermediates of the assembly reaction could not be isolated from cells infected with wt SV40. Here we have used recombinant VP1 produced in insect cells for in vitro assembly studies around supercoiled heterologous plasmid DNA carrying a reporter gene. This strategy yields infective nanoparticles, affording a simple quantitative transduction assay. We show that VP1 assembles under physiological conditions into uniform nanoparticles of the same shape, size and CsCl density as the wild type virus. The stoichiometry is one DNA molecule per capsid. VP1 deleted in the C-arm, which is unable to assemble but can bind DNA, was inactive indicating genuine assembly rather than non-specific DNA-binding. The reaction requires host enzymatic activities, consistent with the participation of chaperones, as recently shown. Our results demonstrate dramatic cooperativity of VP1, with a Hill coefficient of ∼6. These findings suggest that assembly may be a concerted reaction. We propose that concerted assembly is facilitated by simultaneous binding of multiple capsomers to a single DNA molecule, as we have recently reported, thus increasing their local concentration. Emerging principles of SV40 assembly may help understanding assembly of other complex systems. In addition, the SV40-based nanoparticles described here are potential gene therapy vectors that combine efficient gene delivery with safety and flexibility

IMI : global trends in myopia management attitudes and strategies in clinical practice : 2022 update

PURPOSE. Surveys in 2015 and 2019 identified a high level of eye care practitioner concern/activity about myopia, but the majority still prescribed single vision interventions to young myopes. This research aimed to provide updated information. METHODS. A self-administered, internet-based questionnaire was distributed in 13 languages, through professional bodies to eye care practitioners globally. The questions examined awareness of increasing myopia prevalence, perceived efficacy and adoption of available strategies, and reasons for not adopting specific strategies. RESULTS. Of the 3195 respondents, practitioners’ concern about the increasing frequency of pediatric myopia in their practices differed between continents (P < 0.001), being significantly higher in Asia (9.0 ± 1.5 of 10) than other continents (range 7.7–8.2; P ≤ 0.001). Overall, combination therapy was perceived by practitioners to be the most effective method of myopia control, followed by orthokeratology and pharmaceutical approaches. The least effective perceived methods were single vision distance undercorrection, spectacles and contact lenses, as well as bifocal spectacles. Practitioners rated their activity in myopia control between (6.6 ± 2.9 in South America to 7.9 ± 1.2/2.2 in Australasia and Asia). Single-vision spectacles are still the most prescribed option for progressing young myopia (32.2%), but this has decreased since 2019, and myopia control spectacles (15.2%), myopia control contact lenses (8.7%) and combination therapy (4.0%) are growing in popularity. CONCLUSIONS. More practitioners across the globe are practicing myopia control, but there are still significant differences between and within continents. Practitioners reported that embracing myopia control enhanced patient loyalty, increasing practice revenue and improving job satisfaction

The epidemiology and treatment of conjunctivitis at Urgent Care Centres in Israel

Ariela Gordon-Shaag,1 Deena Rachel Zimmerman,2 Einat Shneor11Department of Optometry, Hadassah Academic College, Jerusalem 9101001, Israel; 2TEREM Emergency Medical Centers, Jerusalem 9546303, IsraelPurpose: Conjunctivitis is the most common ocular condition diagnosed at emergency departments (ED) in the USA, although it is generally not an emergent condition. Treatment of conjunctivitis at Urgent Care Centres (UCC) could offer lower cost than ED. This study describes the demographics and outcomes of a cohort presenting with conjunctivitis to a nationwide UCC system.Methods: This retrospective study included 17 branches of UCC. Electronic Medical Record data (November 2015&ndash;October 2016) of patients diagnosed with conjunctivitis or ocular disorder were retrieved. Data included gender, age, diagnosis, treatment, discharge status and temperature. Patients without conjunctivitis, presenting to UCC during this period served as the control. Results were compared to all ED patients in Israel (from a public report). Descriptive statistics, Chi-square and Z-proportion test were used.Results: Altogether, 602,074 patients presented to UCC, of which 5,045 (0.84%, 95% CI 0.74&ndash;0.94%) were diagnosed with conjunctivitis. Conjunctivitis was more prevalent among young males (0&ndash;14, p&lt;0.001) and older females. The conjunctivitis cohort at UCC was significantly younger than the ED cohort (p&lt;0.01). UCC treated and released home 96.7% (95% CI 96.2&ndash;97.2%) of cases. This is significantly higher than the treatment rate for the entire UCC cohort (93.2%, CI 93.2&ndash;93.3%, p&lt;0.05). Treatment in most cases (82.0%, 95% CI 80.9&ndash;83.0%) involved the prescription of ocular antibiotic.Conclusion: Similar to previous studies at ED, conjunctivitis patients are primarily young males. Most patients were treated with antibiotics at UCC and released home. This suggests that UCC may be a good venue for treatment of conjunctivitis.Keywords: conjunctivitis, urgent care centers, emergency department, public healt

Validation of keratometric measurements obtained with a new integrated aberrometry-topography system

2011-2012 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Bilateral chorioretinal coloboma discovered with ultra-wide field retinal imaging

2012-2013 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Objective Behavioral Measures in Children before, during, and after the COVID-19 Lockdown in Israel

Studies using questionnaires report that COVID-19 restrictions resulted in children spending significantly less time outdoors. This study used objective measures to assess the impact of pandemic-related restrictions on children’s behavior. A total of 19 healthy 8–12-year-old boys were observed before and during social restriction periods. Of these, 11 boys were reassessed after restrictions were lifted. For each session, Actiwatches were dispensed for measures of time outdoors, activity, and sleep. Changes overall and by school status were assessed using signed-rank test and Wilcoxon rank sum tests. During restrictions, children spent significantly less time outdoors (p = 0.001), were less active (p = 0.001), and spent less time engaged in moderate-to-vigorous physical activity (p = 0.004). Sleep duration was not significantly different between sessions (p &gt; 0.99), but bedtime and wake time shifted to a later time during restrictions (p &lt; 0.05 for both). Time outdoors and activity returned close to pre-pandemic levels after restrictions were lifted (p &gt; 0.05 for both). Children’s behaviors significantly changed during the COVID-19 pandemic. The reduction in outdoor light exposure is of importance due to the role of light in the etiology of myopia and vitamin D production. The reduction in physical activity may have negative health effects in terms of obesity and depression, although further research is required to ascertain the long-term effects