A novel in vivo corneal trans-epithelial electrical resistance measurement device

Purpose: To develop a device that is capable of easily measuring corneal transepithelial electrical resistance (TER) and changes in the corneal barrier function. Methods: We had previously developed an in vivo method for measuring corneal TER using intraocular electrode. This method can be used to precisely measure the decline of the corneal barrier function after instillation of benzalkonium chloride (BAC). In order to lessen the invasiveness of that procedure, we further refined the method for measuring the corneal TER by developing electrodes that could be placed on the cornea and in the conjunctival sac instead of inserting them into the anterior chamber. TER was then calculated by subtracting the electrical resistance, which lacked the corneal epithelial input, from the whole electrical resistance that was measured between the electrodes. Slit lamp examination and scanning electron microscopy (SEM) were used to determine safety of the new device. Corneal TER changes after exposure to 0.02% BAC were determined using the new device as well as SEM and transmission electron microscopy (TEM). Results: Slit lamp examination before and after exposure of rabbits\u27 corneas to the sensor confirmed safety of the device. SEM examination revealed no difference of the corneal epithelium which exposed to the new device with normal corneas. SEM and TEM pictures revealed damaged microvilli and tight junctions after instillation of 0.02% BAC. TER change after treatment with 0.02%BAC was similar to those determined by the established anterior chamber method. Conclusion: We succeeded to develop a less invasive device for corneal TER measurement in vivo in animals. This new device may be applicable in the future for clinical use in humans

Conjunctival Sac Microbiome in Infectious Conjunctivitis

Acute bacterial conjunctival infections are common, and this study identified the conjunctival bacterial community in infectious conjunctivitis cases seen at the outpatient clinic of Khanh Hoa General Hospital in Nha Trang, Vietnam from October 2016 through December 2017. Conjunctival swabs were collected and tested using conventional culture, PCR, and 16S ribosomal RNA sequencing. The study included 47 randomly selected patients. More than 98% of all DNA reads represented five bacterial phyla. Three of these phyla constituted 92% of all sequences (Firmicutes (35%), Actinobacteria (31%), and Proteobacteria (26%)). At the genus level, there were 12 common genera that constituted about 61% of all sequence reads. Seven of those genera were common (Streptococcus (10%), Cutibacterium (10%), Staphylococcus (7%), Nocardioides (7%), Corynebacterium 1 (5%), Anoxybacillus (5%), and Acinetobacter (5%)), which encompassed 49% of all reads. As for diversity analysis, there was no difference on PERMANOVA analysis (unweighted UniFrac) for sex (p = 0.087), chemosis (p = 0.064), and unclassified eyedrops (p = 0.431). There was a significant difference in cases with bilateral conjunctivitis (p = 0.017) and for using antibiotics (p = 0.020). Of the predominant phyla, Firmicutes had the highest abundance in bacterial conjunctivitis in this study. Pseudomonas as a resident commensal microbiota may have an important role in the prevention of infection

Burnout among surgeons before and during the SARS-CoV-2 pandemic: an international survey

Background: SARS-CoV-2 pandemic has had many significant impacts within the surgical realm, and surgeons have been obligated to reconsider almost every aspect of daily clinical practice. Methods: This is a cross-sectional study reported in compliance with the CHERRIES guidelines and conducted through an online platform from June 14th to July 15th, 2020. The primary outcome was the burden of burnout during the pandemic indicated by the validated Shirom-Melamed Burnout Measure. Results: Nine hundred fifty-four surgeons completed the survey. The median length of practice was 10 years; 78.2% included were male with a median age of 37 years old, 39.5% were consultants, 68.9% were general surgeons, and 55.7% were affiliated with an academic institution. Overall, there was a significant increase in the mean burnout score during the pandemic; longer years of practice and older age were significantly associated with less burnout. There were significant reductions in the median number of outpatient visits, operated cases, on-call hours, emergency visits, and research work, so, 48.2% of respondents felt that the training resources were insufficient. The majority (81.3%) of respondents reported that their hospitals were included in the management of COVID-19, 66.5% felt their roles had been minimized; 41% were asked to assist in non-surgical medical practices, and 37.6% of respondents were included in COVID-19 management. Conclusions: There was a significant burnout among trainees. Almost all aspects of clinical and research activities were affected with a significant reduction in the volume of research, outpatient clinic visits, surgical procedures, on-call hours, and emergency cases hindering the training. Trial registration: The study was registered on clicaltrials.gov "NCT04433286" on 16/06/2020

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Retrospective evaluation of whole exome and genome mutation calls in 746 cancer samples

Funder: NCI U24CA211006Abstract: The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) curated consensus somatic mutation calls using whole exome sequencing (WES) and whole genome sequencing (WGS), respectively. Here, as part of the ICGC/TCGA Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium, which aggregated whole genome sequencing data from 2,658 cancers across 38 tumour types, we compare WES and WGS side-by-side from 746 TCGA samples, finding that ~80% of mutations overlap in covered exonic regions. We estimate that low variant allele fraction (VAF < 15%) and clonal heterogeneity contribute up to 68% of private WGS mutations and 71% of private WES mutations. We observe that ~30% of private WGS mutations trace to mutations identified by a single variant caller in WES consensus efforts. WGS captures both ~50% more variation in exonic regions and un-observed mutations in loci with variable GC-content. Together, our analysis highlights technological divergences between two reproducible somatic variant detection efforts

Stent boost enhancement compared to intravascular ultrasound in the evaluation of stent expansion in elective percutaneous coronary interventions

Background: Stent underexpansion is a major risk factor for in-stent restenosis and acute in-stent thrombosis1Intravascular ultrasound (IVUS) is one of the standards for detection of stent underexpansion (de Feyter et al. 1999; Mintz et al., 2001). StentBoost (SB) enhancement allows an improved angiographic visualization of the stent (Koolen et al., 2005). Aim of work: Comparison of stent expansion by IVUS and SB enhancement and detection of value of SB to guide dilatation post stent deployment. Methodology: IVUS, SB enhancement and QCA were done in 30 patients admitted for elective stenting procedures .We compared measurements of mean ±standard deviations of (Max SD, Min SD, Mean SD, stent symmetry index) using IVUS, SB and QCA after stent deployment and after postdilatation whenever necessary to optimize stent deployment. The Stent symmetry index was calculated [(maximum stent diameter minus minimum stent diameter) divided by maximum stent diameter]. Results: The Max SD was (3.45 ± 0.62 vs 3.55 ± 0.56 vs 2.97 ± 0.59) by IVUS vs SB vs QCA respectively. Max SD was significantly higher by IVUS vs QCA (p .009) and between SB vs QCA (p .001) while there was nonsignificant difference between IVUS vs SB (p .53). The Min SD was (2.77 ± 0.53 vs 2.58 ± 0.56 vs 1.88 ± 0.60) by IVUS vs SB vs QCA respectively. Min SD was significantly higher by IVUS vs QCA (p .001) and between SB vs QCA (p .001) while there was nonsignificant difference between IVUS vs SB (p .07). The stent symmetry index was (0.24 ±0.09 vs 0.34 ± 0.09 vs 0.14 ±0.27) by IVUS vs SB vs QCA respectively. It was significantly higher by IVUS vs QCA (p .001) and between SB vs QCA (p .001) while there was nonsignificant difference between IVUS vs SB (p .32). SB was positively correlated with IVUS measurements of Max SD (p < .0001 & r 0.74) and Min SD (p < .0001 & r 0.68). QCA was positively correlated with IVUS measurements of Max SD correlation (p < .0001 & r 0.69) and Min SD (p < .0001 & r 0.63). QCA was positively correlated with SB measurements of Max SD (p < .0001 & r 0.61) and Min SD (p .003 & r 0.49). Conclusions: StentBoost enhancement has superior correlations for stent expansion measured by IVUS when compared with QCA. SB enhancement improved stent visualization and identification of stent underexpansion to guide stent postdilatation. Keywords: Quantitative coronary angiography (QCA), Intravascular ultrasound (IVUS), Stent Boost (SB) enhancement, Maximal stent diameter (Max SD), Minimal stent diameter (Min SD

Oral kallidinogenase improved visual acuity and maintained chorioretinal blood flow levels after treatment for diabetic macular edema

Purpose: This study was designed to investigate the therapeutic effects of oral kallidinogenase medication as an adjuvant therapy in treating patients with diabetic macular edema (DME). Study design: This was a prospective, open-labeled, randomized study. Methods: All patients were given posterior sub-Tenon triamcinolone acetonide (STTA) injection and focal laser treatment session for DME. The patients were subdivided into two groups: 1) those treated with oral kallidinogenase for at least 6 months after local treatment(treated group) and 2) those treated without oral kallidinogenase (untreated group). In this study, best-corrected visual acuity (BCVA), central retinal thickness (CRT), subfoveal choroidal thickness (SCT), and chorioretinal blood flow level were measured in 17 patients (19 eyes). Chorioretinal blood flow levels at the disc and macula were measured by laser speckle flowgraphy and evaluated using the mean blur rate (MBR). These data were measured at baseline and at 1, 3, and 6 months after treatment initiation. Results: BCVA at 6 months after treatment significantly improved in treated group (P,0.05).But the mean CRT after treatment significantly decreased in both groups. There was no significant difference in the mean SCT at baseline between the two groups. The mean SCT after treatment in treated group was significantly thinner than that before treatment(P,0.05). Compared to baseline (100%), MBR at the disc and the macula at 6 months after treatment significantly decreased to 84.8% and 86.2%, respectively, in untreated group (P,0.05), though it remained unchanged at 98.7% and 99.7% in treated group.Conclusion: Oral kallidinogenase medication is useful as an adjuvant therapy to enhance the therapeutic effect of STTA in DME patients

Success Rates of Vitrectomy in Treatment of Rhegmatogenous Retinal Detachment

Aim. To investigate the anatomical success rates of pars plana vitrectomy (PPV) after primary rhegmatogenous retinal detachment (RRD). Methods. This retrospective study was conducted between December 2008 and October 2014 at Nagasaki University Hospital. The preoperative data recorded included the lens status, location of the retinal tear, whether a tear was visualized, presence of multiple tears, macula status, presence of peripheral lattice retinal degeneration, and best-corrected visual acuity (BCVA). The primary outcome measures were anatomical (primary and final) and functional success (visual acuity better than 6/60). Results. This study evaluated 422 eyes of 411 patients with a mean age of 57.7±11.2 years. The single-operation reattachment rate (primary anatomical success) was 89.8%. The final anatomical success rate was 100% after 2–6 operations (mean = 3.14±1.03). Functional success rate after the primary reattachment operation was 96.7%, while it was 97.2% at the end of the follow-up. Multiple logistic regression analysis of the possible risk factors for the primary anatomical failure showed a significant relation with the 25 G instruments (P=0.002) and the presence of multiple tears (P=0.01). Conclusion. The primary anatomical success of PPV for primary uncomplicated RRD was 89.8% and the final anatomical success rate was 100%