Optimization of mouse kidney digestion protocols for single-cell applications.

Single-cell technologies such as flow cytometry and single-cell RNA sequencing have allowed for comprehensive characterization of the kidney cellulome. However, there is a disparity in the various protocols for preparing kidney single-cell suspensions. We aimed to address this limitation by characterizing kidney cellular heterogeneity using three previously published single-cell preparation protocols. Single-cell suspensions were prepared from male and female C57BL/6 kidneys using the following kidney tissue dissociation protocols: a scRNAseq protocol (P1), a multi-tissue digestion kit from Miltenyi Biotec (P2), and a protocol established in our laboratory (P3). Following dissociation, flow cytometry was used to identify known major cell types including leukocytes (myeloid and lymphoid), vascular cells (smooth muscle and endothelial), nephron epithelial cells (intercalating, principal, proximal, and distal tubule cells), podocytes, and fibroblasts. Of the protocols tested, P2 yielded significantly less leukocytes and type B intercalating cells compared with the other techniques. P1 and P3 produced similar yields for most cell types; however, endothelial and myeloid-derived cells were significantly enriched using P1. Significant sex differences were detected in only two cell types: granulocytes (increased in males) and smooth muscle cells (increased in females). Future single-cell studies that aim to enrich specific kidney cell types may benefit from this comparative analysis.NEW & NOTEWORTHY This study is the first to evaluate published single-cell suspension preparation protocols and their ability to produce high-quality cellular yields from the mouse kidney. Three single-cell digestion protocols were compared and each produced significant differences in kidney cellular heterogeneity. These findings highlight the importance of the digestion protocol when using single-cell technologies. This study may help future single-cell science research by guiding researchers to choose protocols that enrich certain cell types of interest.

Factor structure, reliability and criterion-related validity of the English version of the Problematic Series Watching Scale.

BACKGROUND: Psychological research in the past decade has investigated the psychosocial implications of problematic use of on-demand online video streaming services, particularly series watching. Yet, a psychometric measure of problematic series watching in English is not available. AIMS: The present study aimed to test the factor structure, reliability and criterion-related validity of the English version of the Problematic Series Watching Scale, a six-item self-report assessing problematic series watching, based on the biopsychosocial components model of addiction. METHOD: Participants were recruited from two UK university student samples. Study 1 (n = 333) comprised confirmatory factor analysis, reliability tests and item response theory analyses to test the original unidimensional model and investigate each item's levels of discrimination and information. Study 2 (n = 209) comprised correlation analyses to test the criterion-related validity of the scale. RESULTS: There was a good fit of the theoretical model of the scale to the data (Comparative Fit Index = 0.998, Root Mean Square Error of Approximation = 0.024 [90% CI 0.000-0.093], Standardised Root Mean square Residual = 0.048), satisfactory reliability (ω = 0.79) and item levels of discrimination and information. The scale positively correlated with time spent watching series (rs = 0.26, P < 0.001) and negative affect (rs = 0.43, P < 0.001), and correlated negatively with positive affect (rs = -0.12, P > 0.05), mental well-being (rs = -0.25, P < 0.001) and sleep quality (rs = -0.14, P < 0.05). CONCLUSIONS: Results are discussed in relation to the ongoing debate on binge watching and series watching in the context of positive reinforcement versus problematic behaviour.

Fatal Microangiopathic Hemolytic Anemia Due to Sézary Syndrome.

Sézary syndrome (SS) is a form of cutaneous T-cell lymphoma (CTCL), demonstrating leukemic involvement of malignant T-cells. Known systemic sequelae of SS include hemophagocytic syndrome-induced anemia, normocytic anemia secondary to bone marrow infiltration, and pancytopenia. We report a patient with SS, initially demonstrating widespread morbilliform eruption, who presented with malignancy-related microangiopathic hemolytic anemia (MAHA). Our findings represent a novel presentation of SS that will inform the differential diagnosis and treatment of future SS patients presenting with anemia and thrombocytopenia.

Systematic Review and Meta-Analysis on the Use of Photon-based Stereotactic Radiosurgery Versus Fractionated Stereotactic Radiotherapy for the Treatment of Uveal Melanoma.

PURPOSE: The purpose of this report is to assess the efficacy and adverse event profile of photon-based stereotactic radiosurgery (SRS) compared with fractionated stereotactic radiotherapy (fSRT) for the treatment of uveal melanoma. Primary outcomes include incidence proportions of local control, enucleation, metastatic progression, disease-specific, and overall mortality. Treatment-related toxicities such as incidence proportions of radiation retinopathy, neovascular glaucoma, optic neuropathy, and cataract formation were examined as secondary outcomes. Five-year survival and 5-year local control rates were also assessed. MATERIALS AND METHODS: PubMed, Embase, Web of Science, Scopus, and 2 Cochrane databases were searched up to December 31, 2018. Random effects models were used to calculate pooled incidence proportions of outcome measures. Meta-regression was carried out to explore the potential impact of dose per fraction on local control. RESULTS: Twenty-four articles with a total of 1745 patients were included in the meta-analysis. There were no statistically significant differences between photon-based fSRT and SRS for all primary, secondary and 5-year outcome measures, including local control (P=0.28), enucleation (P=0.51), and neovascular glaucoma (P=0.40). The 5-year local control rate was 90% (95% confidence interval: 76%, 96%) for fSRT and 89% (70%, 97%) for SRS. CONCLUSIONS: Our meta-analysis showed no difference in tumor control, survival and toxicities, as defined in this paper, between SRS and fSRT for uveal melanoma. Confounding biases remain an expected limitation in this study of novel treatment modalities deployed in rare tumors. Further investigation is needed to validate outcomes and compare stereotactic treatment techniques.

Determination of Ethanol Content in Kombucha Using Headspace Gas Chromatography with Mass Spectrometry Detection: Single-Laboratory Validation.

BACKGROUND: Kombucha is a fermented beverage made with tea, sugar, and a symbiotic colony of bacteria and yeast that is usually marketed as a non-alcoholic beverage. Products must contain <0.5% and <1.1% alcohol by volume in the United States and Canada respectively to be classified as non-alcoholic products. Prior studies have found that Kombucha beverages can become very acidic and may contain levels of alcohol above 1% which can be a potential health risk to children and the developing fetus during pregnancy. OBJECTIVE: Given the public safety concerns and legal requirements associated with the level of alcohol within Kombucha beverages, there is a need for accurate and reliable methods. Herein we describe the validation of a sensitive, rapid, and simple Headspace Gas Chromatographic method with mass spectrometric detection for determining ethanol in Kombucha. METHODS: Method performance characteristics measured included linearity, accuracy, precision, limit of detection (LOD), and limit of quantification (LOQ) as per AOAC International guideline Appendix K Part 1. Performance was evaluated against the AOAC Standard Method Performance Requirements 2016.001 for determination of ethanol in Kombucha. RESULTS: The linear dynamic range for this method was confirmed over the range of 0.025 to 2.47% ABV. The LOD and LOQ were determined to be 0.0002% and 0.002% ABV, respectively. With a spike recovery of 102% for accuracy and precision of RSDr ≤ 4% the method met the SMPR requirements within the analytical range. CONCLUSIONS: The results of this validation study demonstrated the method is fit for the purpose of quantifying ethanol in Kombucha and is suitable for rapid and easy integration by laboratories to ensure that regulatory requirements are met.

Barriers and job satisfaction among dermatology hospitalists.

Dermatology hospitalists (DHs) provide consultative care to inpatients with skin conditions. In this study, we surveyed current members of the Society for Dermatology Hospitalists (SDH) regarding barriers to care, current and ideal compensation models, and overall job satisfaction to evaluate the overall job satisfaction of DHs and further describe potential barriers to inpatient dermatology consultations.

DICER1 Syndrome: DICER1 Mutations in Rare Cancers.

DICER1 syndrome is a rare genetic disorder that predisposes individuals to multiple cancer types. Through mutations of the gene encoding the endoribonuclease, Dicer, DICER1 syndrome disrupts the biogenesis and processing of miRNAs with subsequent disruption in control of gene expression. Since the first description of DICER1 syndrome, case reports have documented novel germline mutations of the DICER1 gene in patients with cancers as well as second site mutations that alter the function of the Dicer protein expressed. Here, we present a review of mutations in the DICER1 gene, the respective protein sequence changes, and clinical manifestations of DICER1 syndrome. Directions for future research are discussed.