Pseudomonas aeruginosa senses and responds to epithelial potassium flux via Kdp operon to promote biofilm.

Mucosa-associated biofilms are associated with many human disease states, but the host mechanisms promoting biofilm remain unclear. In chronic respiratory diseases like cystic fibrosis (CF), Pseudomonas aeruginosa establishes chronic infection through biofilm formation. P. aeruginosa can be attracted to interspecies biofilms through potassium currents emanating from the biofilms. We hypothesized that P. aeruginosa could, similarly, sense and respond to the potassium efflux from human airway epithelial cells (AECs) to promote biofilm. Using respiratory epithelial co-culture biofilm imaging assays of P. aeruginosa grown in association with CF bronchial epithelial cells (CFBE41o-), we found that P. aeruginosa biofilm was increased by potassium efflux from AECs, as examined by potentiating large conductance potassium channel, BKCa (NS19504) potassium efflux. This phenotype is driven by increased bacterial attachment and increased coalescence of bacteria into aggregates. Conversely, biofilm formation was reduced when AECs were treated with a BKCa blocker (paxilline). Using an agar-based macroscopic chemotaxis assay, we determined that P. aeruginosa chemotaxes toward potassium and screened transposon mutants to discover that disruption of the high-sensitivity potassium transporter, KdpFABC, and the two-component potassium sensing system, KdpDE, reduces P. aeruginosa potassium chemotaxis. In respiratory epithelial co-culture biofilm imaging assays, a KdpFABCDE deficient P. aeruginosa strain demonstrated reduced biofilm growth in association with AECs while maintaining biofilm formation on abiotic surfaces. Furthermore, we determined that the Kdp operon is expressed in vivo in people with CF and the genes are conserved in CF isolates. Collectively, these data suggest that P. aeruginosa biofilm formation can be increased by attracting bacteria to the mucosal surface and enhancing coalescence into microcolonies through aberrant AEC potassium efflux sensed by the KdpFABCDE system. These findings suggest host electrochemical signaling can enhance biofilm, a novel host-pathogen interaction, and potassium flux could be a therapeutic target to prevent chronic infections in diseases with mucosa-associated biofilms, like CF.

A systematic review of the incidence of basal cell carcinoma with perineural invasion: conventional pathology versus Mohs micrographic surgery.

Incidence of basal cell carcinoma (BCC) with perineural invasion (PNI) ranges from 0.178 to 10% depending upon whether conventional pathology (formalin fixed, paraffin embedded) or Mohs micrographic surgery (MMS) (frozen sections) is used. To determine the incidence of BCC with PNI determined by conventional pathology versus MMS. A review of PubMed and EMBASE databases, from their inception to December 18th, 2020, identified articles that determined the incidence of BCC with PNI using conventional pathology or MMS. The general (average) incidence of BCC with PNI as determined by studies that used conventional histopathology and MMS was 0.85 and 2.51%, respectively. The observed incidence of BCC with PNI was not significantly higher using MMS compared to conventional pathology (p = 0.82).

Neutrophil-vascular interactions drive myeloperoxidase accumulation in the brain in Alzheimer's disease.

INTRODUCTION: Neutrophil accumulation is a well-established feature of Alzheimer's disease (AD) and has been linked to cognitive impairment by modulating disease-relevant neuroinflammatory and vascular pathways. Neutrophils express high levels of the oxidant-generating enzyme myeloperoxidase (MPO), however there has been controversy regarding the cellular source and localisation of MPO in the AD brain. MATERIALS AND METHODS: We used immunostaining and immunoassays to quantify the accumulation of neutrophils in human AD tissue microarrays and in the brains of APP/PS1 mice. We also used multiplexed immunolabelling to define the presence of NETs in AD. RESULTS: There was an increase in neutrophils in AD brains as well as in the murine APP/PS1 model of AD. Indeed, MPO expression was almost exclusively confined to S100A8-positive neutrophils in both human AD and murine APP/PS1 brains. The vascular localisation of neutrophils in both human AD and mouse models of AD was striking and driven by enhanced neutrophil adhesion to small vessels. We also observed rare infiltrating neutrophils and deposits of MPO around plaques. Citrullinated histone H3, a marker of neutrophil extracellular traps (NETs), was also detected in human AD cases at these sites, indicating the presence of extracellular MPO in the vasculature. Finally, there was a reduction in the endothelial glycocalyx in AD that may be responsible for non-productive neutrophil adhesion to the vasculature. CONCLUSION: Our report indicates that vascular changes may drive neutrophil adhesion and NETosis, and that neutrophil-derived MPO may lead to vascular oxidative stress and be a relevant therapeutic target in AD.

Usefulness of deamidated gliadin peptide antibodies in diagnosing coeliac disease in children younger than 3 years old.

AIM: The standard serological test to screen for coeliac disease (CD) is tissue transglutaminase (tTG) but some experts recommend including deamidated gliadin peptide (DGP) antibodies for children younger than 3 years old. This study evaluated the utility of DGP-immunoglobulin A (IgA) and DGP-immunoglobulin G (IgG) serologies when screening children younger than 3 years old for CD. METHODS: A retrospective chart review was conducted including children 3 years old and under, who had DGP and/or tTG serologies along with duodenal biopsies during their initial diagnostic evaluation. Serology results were compared to the gold-standard histopathology by χ2 to determine the significance of including DGP-IgG/IgA serologies when screening for CD in this age group. RESULTS: We identified 478 patients, 52 who were younger than 3 years old, 43 of whom met inclusion criteria. The positive predictive value (PPV) of the DGP-IgA test was 91.7% whereas, DGP-IgG was 77.8%. When DGP serology was examined in conjunction with tTG-IgA, the PPV with DGP-IgA was 90.9% and with DGP-IgG was 87.5%. CONCLUSIONS: In isolation, DGP-IgA provides a high PPV and specificity for CD in children younger than 3 years old, whereas DGP-IgG had a much lower PPV in this age group. When used alone or in conjunction with tTG-IgA, the DGP-IgA test results in a high PPV of 91.7 and 90.9%, respectively. Based on our study, we recommend obtaining both the DGP-IgA and the tTG-IgA serology when screening infants and children younger than 3 years old for coeliac disease.

Reno-appendiceal fistula in autosomal dominant polycystic kidney disease.

We present a very rare Case of a 53-year-old female with autosomal dominant polycystic kidney disease (ADPKD) who was incidentally found to have a reno-appendiceal fistula while undergoing open bilateral nephrectomy. The mid-portion of the appendix was fistulized to a cyst in the lower pole of the right kidney. The etiology was likely due to chronic inflammation. An appendectomy was performed along with the planned right nephrectomy to ensure complete removal of the fistulous tract.

"It Made Me Feel Like I Didn't Know My Own Body": Patient-Provider Relationships, LGBTQ+ Identity, and End-of-Life Discussions.

PURPOSE: LGBTQ+ individuals experience multiple challenges receiving quality care at the end of life, such as lack of confidence in the healthcare system to address their needs and lack of knowledge about advance care planning. Important gaps remain about the needs of LGBTQ+ individuals in the provider-patient relationship and how critical discussions about the end of life occur or do not occur in that relationship. The purpose of this study is to explore patients' narratives of their relationship with their provider and their experiences discussing end-of-life care with their providers, among patients who do and do not identify as LGBTQ+. METHODS: Twenty-nine attendants of an event devoted to LGBTQ+ health, 15 of which identified as LGBTQ+, completed an altered version of the CAHPS® Patient Narrative Elicitation Protocol. We used inductive content analysis to qualitatively analyze the data. RESULTS: Respondents described wanting to be heard, finding safety and trust, and valuing competency in their relationship with their provider. Respondents who identified as LGBTQ+ additionally 1) valued providers who avoided making assumptions, 2) looked for cues of safety to indicate they would be accepted by the provider, and 3) sought providers competent in LGBTQ+ care needs. Few respondents had discussed end-of-life care with their provider, although some assumed that their provider may or may not be able to meet their needs based on aspects of their provider-patient relationship. CONCLUSIONS: Strengthening patient-provider relationships may help improve the care of LGBTQ+ populations, particularly for the end of life.

Hormone therapy and melanoma in women.

Although primary cutaneous melanoma accounts for approximately 3% of all malignant skin tumors, it has the greatest contribution to skin cancer-related death. Sex-specific differences in melanoma tumor behavior have been described, and melanoma pathogenesis may be hormonally mediated. This review aims to summarize the literature to date regarding the effects of hormone therapy on melanoma in women. Women's exogenous hormone use has changed dramatically over the past few decades. Thus, we focus on studies investigating the associations between oral contraception, fertility treatments, menopausal hormone therapy (MHT), and melanoma. Across hormone therapy types, there does not appear to be a well-established association between exogenous female hormones and melanoma incidence. However, MHT practices and formulations vary significantly across countries. Although MHT does not appear to increase melanoma risk in studies from the United States, conflicting results have been observed in Europe. Unopposed estrogen MHT formulations require further investigation to determine a clear pattern between hormone use and the development of melanoma.

Thieno[3,2- b]pyrrole-benzothiadiazole Banana-Shaped Small Molecules for Organic Field-Effect Transistors.

We report two banana-shaped organic semiconducting small molecules containing the relatively unexplored thieno[3,2- b]pyrrole with thiophene and furan flanked benzothiadiazole. Theoretical insights gained by DFT calculations, supported by single crystal structures show that furan flanked benzothiadiazole-thieno[3,2- b]pyrrole small molecule has a higher curvature compared to the thiophene flanked small molecule due to the shorter carbon-oxygen bond in furan. Despite similar optical and electrochemical properties, thiophene flanked small molecule shows average hole mobility up to 8 × 10-2 cm2 V-1 s-1, however furan flanked small molecule performs poorly in thin film transistor devices (µh ≈ 5 × 10-6 cm2 V-1 s-1). The drastic difference in hole mobilities was due to the annealing-induced crystallinity which was demonstrated by the out-of-plane grazing incidence X-ray diffraction and surface morphology studies by tapping mode atomic force microscopy analysis.

Dietary carbohydrate level affects transcription factor expression that regulates skeletal muscle myogenesis in rainbow trout.

Understanding the effects of dietary carbohydrates on transcription factors that regulate myogenesis provides insight into the role of nutrient sensing by satellite cells towards myocyte differentiation. We evaluated the influence of dietary carbohydrate level (0, 15, 25 or 35%) on the temporal mRNA expression patterns (4, 8 or 12 weeks) of transcription factors that regulate satellite cell myocyte addition (MA) in rainbow trout (Oncorhynchus mykiss), a vertebrate with indeterminate growth. Relative to the 0% carbohydrate (NC) diet, 15 (IC-15) and 25% (IC-25) carbohydrate containing diets significantly up-regulate MyoD and Myf5, but not Pax7, after 12 weeks of feeding. Simultaneously, the Pax7/MyoD mRNA expression ratio declined significantly with both the IC diets. Myogenin mRNA expression also increased in rainbow trout (RBT) fed the IC-15 diet. The high carbohydrate (HC) diet (35%) attenuated the increased mRNA expression of these transcription factors. It is of note that the 4 and 8 week samples lacked the promyogenic expression patterns. The myogenic gene expression in fish fed the IC-15 diet for 12 weeks indicate a transcriptional signature that reflects increased satellite cell myogenesis. Our results suggest a potential role for satellite cells in the nutrient sensing ability of a vertebrate with indeterminate skeletal muscle growth.