The Impact of the COVID-19 Pandemic on Tele-ophthalmology-Based Retinal Screening.

INTRODUCTION: This study reports our experiences with systematic retinal screening in Denmark through optometrists with access to tele-ophthalmological services before, during, and after the COVID-19 pandemic. METHODS: We evaluated an optometrist-based retinal screening system with a referral option for tele-ophthalmological service by a consultant ophthalmologist within the time period of August 1, 2018 to September 30, 2023. The optometrist collected patient history, refraction, best-corrected visual acuity, intraocular pressure, basic slit-lamp examination, 4-in-1 visual field report, and retinal imaging using color fundus 45° photography. Tele-ophthalmological services were provided by consultant ophthalmologists. Within pre-defined periods of pre-COVID-19, COVID-19, and post-COVID-19, we evaluated the rate of referrals to the tele-ophthalmological service, diagnoses made, and referrals to the public healthcare system. RESULTS: A total of 1,142,028 unique individuals, which corresponded to 19.1% of the entire population of Denmark, underwent screening by the optometrists; 50,612 (4.4%) of these individuals were referred to the tele-ophthalmological examination by consultant ophthalmologists. A referral for further ophthalmic examination, either at hospital or at an ophthalmic practice, was made for 10,300 individuals (20.4% of those referred for tele-ophthalmology, corresponding to 0.9% of the population screened). The referral rate from the screening to the tele-ophthalmological service increased from before COVID-19 (3.4%) to during COVID-19 (4.3%) and further after COVID-19 (6.4%). This increase coincided with an increasing prevalence of conditions seen in the tele-ophthalmological service. CONCLUSION: During a period of 5 years, 19.1% of the entire population of Denmark underwent retinal screening. This provided an adjunctive health service during a period of severe strain on the public healthcare system, while limiting the number of excessive referrals to the public healthcare system. Temporal trends illustrated an increased pattern of use of a large-scale tele-ophthalmological system.

Does Improving Depression Symptoms in Young Adults With Inflammatory Bowel Disease Alter Their Microbiome?

BACKGROUND: Patients with inflammatory bowel diseases (IBDs) are more likely to have depression and anxiety symptoms compared with healthy individuals and those with other chronic illnesses. Previous studies have shown a link between the microbiome composition and depression symptoms; however, many antidepressant medications have antibacterial activity confounding cross-sectional studies of these populations. Therefore, we aimed to determine whether we could detect longitudinal changes in the microbiome of a subset of patients who participated in a previously published mindfulness-based cognitive therapy (MBCT) study to improve depression symptoms in adolescents and young adults with IBD. METHODS: Stool samples were collected at baseline and 8 weeks (n = 24 participants, 37 total samples, 13 paired samples). During this time, some participants achieved a 50% reduction in their depression symptoms either through MBCT or treatment as usual with their mental health team (responders). The microbiome composition and function of responders were compared with participants who did not improve their depression scores (nonresponders). Depression scores were determined using the depression, anxiety, and stress score (DASS-21), and metagenomic sequencing of stool samples was performed. RESULTS: No difference in alpha diversity was found between responders and nonresponders. Beta diversity measures were similarly unchanged. Clinical features including fecal calprotectin, C-reactive protein, and serum IL-6 levels were unchanged. CONCLUSIONS: In this small longitudinal study, we were not able to detect longitudinal changes in the microbiome associated with improvement in depression scores. Follow-up studies that are sufficiently powered to detect changes in the microbiome are required to confirm our results.

In a small cohort of young adults with inflammatory bowel disease and depression symptoms, we observed no significant longitudinal changes in their microbiome following improvement in their depression scores.

Striving for equity: exploring gender-inclusive medical leadership in India.

INTRODUCTION: There is a notable gap in studies examining the impact of gender within sociocultural norms in non-western professional settings, especially concerning the well-being of women physicians. METHODS: Using purposive sampling and thematic data analysis, we recorded interviews with 30 physicians in India during May-July 2023. Participants were aged 34 to 65 years, with experience ranging from five to 35 years, in various clinical (37%), surgical (30%), paraclinical (23%) and hospital administration (10%) roles, 97% were postgraduates and 53% were women. The research questions explored how leadership roles happened, managing key challenges, barriers and enablers, and practical interventions to support women into medical leadership positions. RESULTS: Findings revealed that the majority of interviewees believed gender-related barriers were obstructing women's progress and success in medical leadership roles in India. These barriers were identified within three overarching domains: (1) specialty, (2) organisational and (3) sociocultural. Interviewees commonly acknowledged the male-dominated landscape of medical leadership although some women stated that they did not perceive any barriers for women's advancement into leadership roles. Interestingly, some men surgeons held the perception that women might not be as effective in certain surgical disciplines, such as orthopaedics and neurosurgery. Some men physicians, however, considered women physicians in India to be highly effective multitaskers. CONCLUSION: We recommend structural reforms in medical education, leadership development, workplace systems and cultures, and improved implementation of equality, diversity and inclusion policies in the Indian context.

Preexisting tissue mechanical hypertension at adherens junctions disrupts apoptotic extrusion in epithelia.

Apical extrusion is a tissue-intrinsic process that allows epithelia to eliminate unfit or surplus cells. This is exemplified by the early extrusion of apoptotic cells, which is critical to maintain the epithelial barrier and prevent inflammation. Apoptotic extrusion is an active mechanical process, which involves mechanotransduction between apoptotic cells and their neighbors, as well as local changes in tissue mechanics. Here we report that the preexisting mechanical tension at adherens junctions (AJs) conditions the efficacy of apoptotic extrusion. Specifically, increasing baseline mechanical tension by overexpression of a phosphomimetic Myosin II regulatory light chain (MRLC) compromises apoptotic extrusion. This occurs when tension is increased in either the apoptotic cell or its surrounding epithelium. Further, we find that the proinflammatory cytokine, TNFα, stimulates Myosin II and increases baseline AJ tension to disrupt apical extrusion, causing apoptotic cells to be retained in monolayers. Importantly, reversal of mechanical tension with an inhibitory MRLC mutant or tropomyosin inhibitors is sufficient to restore apoptotic extrusion in TNFα-treated monolayers. Together, these findings demonstrate that baseline levels of tissue tension are important determinants of apoptotic extrusion, which can potentially be coopted by pathogenetic factors to disrupt the homeostatic response of epithelia to apoptosis.

Quantitative and qualitative analysis of individual experiences post botulinum toxin injection - United Kingdom Survey.

Introduction: In the United Kingdom (UK), complications that arise following the administration of Botulinum Toxin are reported to the Medicines and Health Regulatory Agency (MHRA) via the Yellow Card Reporting Scheme. Over the past decade, there has been a significant increase in the number of non-surgical aesthetic procedures. Concerns have been raised that the MHRA is not fully capturing complications in terms of volume and impact on patients. Aim: This novel study explores the lived experiences of individuals who have experienced an adverse event following administration of Botulinum Toxin for aesthetic purposes. Using a combination of qualitative and quantitative methodologies, this analysis evaluates data relating to long-lasting physical, psychological, emotional, and financial sequelae of complications arising from cosmetic Botulinum Toxin injections in the UK. Methods: A mixed method, qualitative and quantitative approach was adopted to gain comprehensive insights into patients' experiences. A focus group which comprised patient representatives, psychologists, and researchers reached a consensus on a 17-question survey which was disseminated via social media channels. Deductive thematic analysis was used to analyse coded themes. Furthermore, for secondary analysis, sentiment analysis was used computationally as an innovative approach to identify and categorise free text responses associated with sentiments using natural language processing (NLP). Results: In the study, 655 responses were received, with 287 (44%) of respondents completing all questions. The mean age of respondents was 42.6 years old. 94.1% of respondents identified as female. In the sample, 79% of respondents reported an adverse event following their procedure, with the most common event being reported as 'anxiety'. Findings revealed that 69% of respondents reported long-lasting adverse effects. From the responses, 68.4% reported not having recovered physically, 63.5% of respondents stated that they had not recovered emotionally from complications, and 61.7% said that they have not recovered psychologically. In addition, 84% of respondents stated that they do not know who regulates the aesthetics industry. Furthermore, 92% of participants reported that their clinic or practitioner did not inform them about the Yellow Card Reporting Scheme. The sentiment analysis using the AFINN Lexicon yielded adjusted scores ranging from -3 to +2, with a mean value of -1.58. Conclusion: This is the largest survey in the UK completed by patients who experienced an adverse outcome following the aesthetic administration of Botulinum Toxin. Our study highlights the extent of the challenges faced by patients who experience an adverse event from physical, emotional, psychological, and financial perspectives. The lack of awareness of MHRA reporting structures and the lack of regulation within the UK's cosmetic injectables sector represent a significant public health challenge.

Profiling UK injectable aesthetic practitioners: A national cohort analysis.

INTRODUCTION: The United Kingdom (UK) injectables market has been growing rapidly with a lack of robust regulation and to date, no information regarding the profile of practitioners has been published. AIM: We aim to provide a descriptive and qualitative analysis of the advertised practitioners in the United Kingdom. METHODS: We performed a systematic search using the internet search engine Google to perform a qualitative descriptive analysis of aesthetic practitioners in the UK. For each contiguous country in the UK: England, Scotland, and Wales, five searches were performed. The list of practitioners was then cross-referenced with professional regulatory bodies, with extraction of registration number, date of registration and presence or absence from the Specialist Register or General Practitioner Register. RESULTS: 3000 websites were visited and evaluated. 1224 independent clinics with 4405 practitioners were identified. 738 were identified as those in business support functions and the remaining 3667 practitioners were undertaking injectable practice. The profile of professions were doctors 32%, nurses 13%, dentists 24% and dental nurses 8%. Of the 1163 doctors identified 481 were on the specialist register (41%) and 219 were on the GP register (19%). 27 specialties were represented in this cohort analysis. Plastic Surgery formed the majority of those who were on the specialist register at 37%, followed by Dermatology at 18%. CONCLUSION: This paper is the first to describe the range of practitioners, their professional backgrounds and experience who perform non-surgical aesthetic interventions. The range of backgrounds may have an impact on the potential risks to patients and will be an important consideration in proposed legislation to introduce licensing to the industry.

MUC13 Cell Surface Mucin Limits Salmonella Typhimurium Infection by Protecting the Mucosal Epithelial Barrier.

BACKGROUND & AIMS: MUC13 cell surface mucin is highly expressed on the mucosal surface throughout the intestine, yet its role against bacterial infection is unknown. We investigated how MUC13 impacts Salmonella typhimurium (S Tm) infection and elucidated its mechanisms of action. METHODS: Muc13-/- and wild-type littermate mice were gavaged with 2 isogenic strains of S Tm after pre-conditioning with streptomycin. We assessed clinical parameters, cecal histology, local and systemic bacterial load, and proinflammatory cytokines after infection. Cecal enteroids and epithelial cell lines were used to evaluate the mechanism of MUC13 activity after infection. The interaction between bacterial SiiE and MUC13 was assessed by using siiE-deficient Salmonella. RESULTS: S Tm-infected Muc13-/- mice had increased disease activity, histologic damage, and higher local and systemic bacterial loads. Mechanistically, we found that S Tm binds to MUC13 through its giant SiiE adhesin and that MUC13 acts as a pathogen-binding decoy shed from the epithelial cell surface after pathogen engagement, limiting bacterial invasion. In addition, MUC13 reduces epithelial cell death and intestinal barrier breakdown by enhancing nuclear factor kappa B signaling during infection, independent of its decoy function. CONCLUSIONS: We show for the first time that MUC13 plays a critical role in antimicrobial defense against pathogenic S Tm at the intestinal mucosal surface by both acting as a releasable decoy limiting bacterial invasion and reducing pathogen-induced cell death. This further implicates the cell surface mucin family in mucosal defense from bacterial infection.

Cosmetic business mechanics in London: A cross-sectional analysis and audit of ASA compliance.

INTRODUCTION: The proliferation of providers and practitioners of cosmetic botulinum toxin and dermal filler has profound public health implications. The Advertising Standards Authority (ASA) regulates the use of advertising materials in the United Kingdom and prohibits the promotion of prescription-only medicines. AIMS: We aim to perform a cross-sectional analysis of the practitioners in London, UK to evaluate the distribution of clinics within Greater London, prices advertised for interventions, and compliance with the ASA code. We also aim to identify whether there are any differences in cost of botulinum toxin or dermal filler between the boroughs. METHODS: Between December 2021 and January 2022, we performed a systematic search using the internet search engine Google. Five searches were performed (1) [london] botox, (2) [london] botulinum toxin, (3) [london] anti wrinkle injection, (4) [london] filler, (5) [london] dermal filler. One hundred websites per search string were systematically reviewed and those which met the inclusion/exclusion criteria of each search string were included and analyzed. Each clinic's product/service range compliance with the ASA/CAP code was assessed. Any reference to Botulinum Toxin or anti-wrinkle injections was noted and analyzed. Further analysis would look to calculate price per milliliter (mL) of botulinum toxin and dermal filler per borough and to calculate whether there were any statistical differences between the 32 different London boroughs. RESULTS: A total of 500 websites were visited and evaluated. After removal of duplicates, a total of 233 independent clinics was identified. A total of 206 out of the 233 clinics sampled (88%) were in direct infringement of the enforcement notice through advertising a prescription medicine. The overall average cost per mL of dermal filler was £330.89 and there was a statistically significant variance across London boroughs (p < 0.05). The overall average cost per mL of Botulinum Toxin was £284.45 and the variance across London boroughs was close to significant (p = 0.058). CONCLUSION: This paper demonstrates poor compliance with the ASA/CAP guidelines and further provides an insight into the industry mechanics associated with aesthetic injectables in a major UK city, identifying regional variance in price and clinic density. The advertising of prescription-only medication may pose a potential risk to patients and will be an important consideration in proposed legislation to introduce licensing to the industry.

Gut inflammation and adaptive immunity amplify acetaminophen toxicity in bowel and liver.

BACKGROUND AND AIM: Prevention of liver failure arising from accidental or deliberate paracetamol (acetaminophen [APAP]) overdose remains a vexed health problem despite well-publicized guidelines for its early detection and treatment. It is recognized that the gut may aggravate liver pathology, via the gut-liver axis. The main aim of this study was to assess the role of the colon in APAP-induced liver toxicity. METHODS: Liver necrosis and colitis were studied following sublethal doses of APAP administered intraperitoneally to C57Bl/6 wild-type (WT) mice, as well as to C57Bl/6 Winnie mice, which develop a spontaneous colitis caused by a SNP in Muc2, and WT mice with acute DSS-induced colitis. Repeated APAP exposure was studied in WT and Rag1 ko mice that lack mature T and B lymphocytes. RESULTS: APAP overdose resulted in significant colonic injury in WT mice (P < 0.05), which resolved by 24 h. Underlying colitis was not associated with liver necrosis, but colitis exacerbated APAP-induced liver injury and extended APAP-colonic injury. Prior APAP exposure exacerbated both APAP-liver and APAP-colonic injury more so in WT than Rag1 ko mice. APAP impaired barrier function with increased intestinal permeability and associated bacterial translocation to the liver and spleen in mice with the Winnie phenotype. CONCLUSIONS: This study identifies novel roles for APAP in causing colitis, the amplification of APAP-liver toxicity where there is underlying colitis, and involvement of immune memory in APAP-toxicity. The latter could be key for decoding the poorly understood but important clinical entity of chronic APAP liver failure.

The flutemetamol analogue cyano-flutemetamol detects myocardial AL and ATTR amyloid deposits: a post-mortem histofluorescence analysis.

BACKGROUND: [18F]flutemetamol is a PET radioligand used to image brain amyloid, but its detection of myocardial amyloid is not well-characterized. This histological study characterized binding of fluorescently labeled flutemetamol (cyano-flutemetamol) to amyloid deposits in myocardium. METHODS: Myocardial tissue was obtained post-mortem from 29 subjects with cardiac amyloidosis including transthyretin wild-type (ATTRwt), hereditary/variant transthyretin (ATTRv) and immunoglobulin light-chain (AL) types, and from 10 cardiac amyloid-free controls. Most subjects had antemortem electrocardiography, echocardiography, SPECT and cardiac MRI. Cyano-flutemetamol labeling patterns and integrated density values were evaluated relative to fluorescent derivatives of Congo red (X-34) and Pittsburgh compound-B (cyano-PiB). RESULTS: Cyano-flutemetamol labeling was not detectable in control subjects. In subjects with cardiac amyloidosis, cyano-flutemetamol labeling matched X-34- and cyano-PiB-labeled, and transthyretin- or lambda light chain-immunoreactive, amyloid deposits and was prevented by formic acid pre-treatment of myocardial sections. Cyano-flutemetamol mean fluorescence intensity, when adjusted for X-34 signal, was higher in the ATTRwt than the AL group. Cyano-flutemetamol integrated density correlated strongly with echocardiography measures of ventricular septal thickness and posterior wall thickness, and with heart mass. CONCLUSION: The high selectivity of cyano-flutemetamol binding to myocardial amyloid supports the diagnostic utility of [18F]flutemetamol PET imaging in patients with ATTR and AL types of cardiac amyloidosis.

Transcriptional Behavior of Regulatory T Cells Predicts IBD Patient Responses to Vedolizumab Therapy.

BACKGROUND: Inflammatory bowel disease (IBD) involves chronic T cell-mediated inflammatory responses. Vedolizumab (VDZ), a monoclonal antibody against α4ß7 integrin, inhibits lymphocyte extravasation into intestinal mucosae and is effective in ulcerative colitis (UC) and Crohn's disease (CD). AIM: We sought to identify immune cell phenotypic and gene expression signatures that related to response to VDZ. METHODS: Peripheral blood (PBMC) and lamina propria mononuclear cells (LPMCs) were analyzed by flow cytometry and Cytofkit. Sorted CD4 + memory (Tmem) or regulatory T (Treg) cells from PBMC and LPMC were analyzed by RNA sequencing (RNA-seq). Clinical response (≥2-point drop in partial Mayo scores [UC] or Harvey-Bradshaw index [CD]) was assessed 14 to 22 weeks after VDZ initiation. Machine-learning models were used to infer combinatorial traits that predicted response to VDZ. RESULTS: Seventy-one patients were enrolled: 37 received VDZ and 21 patients remained on VDZ >2 years. Fourteen of 37 patients (38%; 8 UC, 6 CD) responded to VDZ. Immune cell phenotypes and CD4 + Tmem and Treg transcriptional behaviors were most divergent between the ileum and colon, irrespective of IBD subtype or inflammation status. Vedolizumab treatment had the greatest impact on Treg metabolic pathways, and response was associated with increased expression of genes involved in oxidative phosphorylation. The strongest clinical predictor of VDZ efficacy was concurrent use of thiopurines. Mucosal tissues offered the greatest number of response-predictive biomarkers, whereas PBMC Treg-expressed genes were the best predictors in combinatorial models of response. CONCLUSIONS: Mucosal and peripheral blood immune cell phenotypes and transcriptional profiles can inform VDZ efficacy and inform new opportunities for combination therapies.

Vedolizumab (VDZ) is effective in the treatment of IBD. Immunophenotyping and RNAseq of T cells were used to inform its mechanism of action. Changes in T regulatory cells in the periphery and mucosa have the greatest relationship to VDZ response.

MUC1-mediated Macrophage Activation Promotes Colitis-associated Colorectal Cancer via Activating the Interleukin-6/ Signal Transducer and Activator of Transcription 3 Axis.

BACKGROUND & AIMS: MUC1 is abnormally expressed in colorectal cancer, including colitis-associated colorectal cancer (CAC), but its role in tumorigenesis is unclear. This study investigated MUC1's effects in murine models of colitis and CAC and elucidated mechanisms of action. METHODS: Colitis and CAC were induced in mice by exposure to dextran sodium sulfate or azoxymethane plus dextran sodium sulphate. Clinical parameters, immune cell infiltration, and tumor development were monitored throughout disease progression. Experiments in knockout mice and bone marrow chimeras were combined with an exploration of immune cell abundance and function. RESULTS: Deficiency of Muc1 suppressed inflammation, inhibited tumor progression, increased abundance of CD8+ T lymphocytes, and reduced abundance of macrophages in colon tumors. Bone marrow chimeras showed promotion of CAC was primarily mediated by Muc1-expressing hematopoietic cells, and that MUC1 promoted a pro-tumoral immunosuppressive macrophage phenotype within tumors. Mechanistic studies revealed that Muc1 deficiency remarkably reduced interleukin-6 levels in the colonic tissues and tumors that was mainly produced by infiltrating macrophages at day 21, 42, and 85. In bone marrow-derived macrophages, MUC1 promoted responsiveness to chemoattractant and promoted activation into a phenotype with high Il6 and Ido1 expression, secreting factors which inhibited CD8+ T cell proliferation. MUC1 potently drives macrophages to produce interleukin-6, which in turn drives a pro-tumorigenic activation of signal transducer and activator of transcription 3 in colon epithelial tumor and stromal cells, ultimately increasing the occurrence and development of CAC. CONCLUSIONS: Our findings provide cellular and molecular mechanisms for the pro-tumorigenic functions of MUC1 in the inflamed colon. Therapeutic strategies to inhibit MUC1 signal transduction warrant consideration for the prevention or therapy of CAC.

Exploring how and why social prescribing evaluations work: a realist review.

OBJECTIVE: The evidence base for social prescribing is inconclusive, and evaluations have been criticised for lacking rigour. This realist review sought to understand how and why social prescribing evaluations work or do not work. Findings from this review will contribute to the development of an evidence-based evaluation framework and reporting standards for social prescribing. DESIGN: A realist review. DATA SOURCES: ASSIA, CINAHL, Embase, Medline, PsycINFO, PubMed, Scopus Online, Social Care Online, Web of Science and grey literature. ELIGIBILITY CRITERIA: Documents reporting on social prescribing evaluations using any methods, published between 1998 and 2020 were included. Documents not reporting findings or lacking detail on methods for data collection and outcomes were excluded. ANALYSIS: Included documents were segregated into subcases based on methodology. Data relating to context, mechanisms and outcomes and the programme theory were extracted and context-mechanism-outcome configurations were developed. Meta-inferences were drawn from all subcases to refine the programme theory. RESULTS: 83 documents contributed to analysis. Generally, studies lacked in-depth descriptions of the methods and evaluation processes employed. A cyclical process of social prescribing evaluation was identified, involving preparation, conducting the study and interpretation. The analysis found that coproduction, alignment, research agency, sequential mixed-methods design and integration of findings all contributed to the development of an acceptable, high-quality social prescribing evaluation design. Context-mechanism-outcome configurations relating to these themes are reported. CONCLUSIONS: To develop the social prescribing evidence base and address gaps in our knowledge about the impact of social prescribing and how it works, evaluations must be high quality and acceptable to stakeholders. Development of an evaluation framework and reporting standards drawing on the findings of this realist review will support this aim. PROSPERO REGISTRATION NUMBER: CRD42020183065.

Breast Tumour Kinase (Brk/PTK6) Contributes to Breast Tumour Xenograft Growth and Modulates Chemotherapeutic Responses In Vitro.

Breast tumour kinase (Brk/PTK6) is overexpressed in up to 86% of breast cancers and is associated with poorer patient outcomes. It is considered a potential therapeutic target in breast cancer, even though the full spectrum of its kinase activity is not known. This study investigated the role of the kinase domain in promoting tumour growth and its potential in sensitising triple negative breast cancer cells to standard of care chemotherapy. Triple negative human xenograft models revealed that both kinase-inactive and wild-type Brk promoted xenograft growth. Suppression of Brk activity in cells subsequently co-treated with the chemotherapy agents doxorubicin or paclitaxel resulted in an increased cell sensitivity to these agents. In triple negative breast cancer cell lines, the inhibition of Brk kinase activity augmented the effects of doxorubicin or paclitaxel. High expression of the alternatively spliced isoform, ALT-PTK6, resulted in improved patient outcomes. Our study is the first to show a role for kinase-inactive Brk in human breast tumour xenograft growth; therefore, it is unlikely that kinase inhibition of Brk, in isolation, would halt tumour growth in vivo. Breast cancer cell responses to chemotherapy in vitro were kinase-dependent, indicating that treatment with kinase inhibitors could be a fruitful avenue for combinatorial treatment. Of particular prognostic value is the ratio of ALT-PTK6:Brk expression in predicating patient outcomes.

Gadolinium: pharmacokinetics and toxicity in humans and laboratory animals following contrast agent administration.

Gadolinium-based contrast agents (GBCAs) have transformed magnetic resonance imaging (MRI) by facilitating the use of contrast-enhanced MRI to allow vital clinical diagnosis in a plethora of disease that would otherwise remain undetected. Although over 500 million doses have been administered worldwide, scientific research has documented the retention of gadolinium in tissues, long after exposure, and the discovery of a GBCA-associated disease termed nephrogenic systemic fibrosis, found in patients with impaired renal function. An understanding of the pharmacokinetics in humans and animals alike are pivotal to the understanding of the distribution and excretion of gadolinium and GBCAs, and ultimately their potential retention. This has been well studied in humans and more so in animals, and recently there has been a particular focus on potential toxicities associated with multiple GBCA administration. The purpose of this review is to highlight what is currently known in the literature regarding the pharmacokinetics of gadolinium in humans and animals, and any toxicity associated with GBCA use.

Successful Manipulation of the Gut Microbiome to Treat Spontaneous and Induced Murine Models of Colitis.

Background and Aims: There is clinical interest in the sustainability or otherwise of prebiotic, microbial, and antibiotic treatments to both prevent and treat inflammatory bowel diseases. This study examined the role of antibiotic manipulation of the gut microbiome to treat spontaneous and induced murine models of colitis. Methods: Symptomatic, histological, molecular, and microbial ecology and bioinformatic readouts were used to study the effect of a 10-day antibiotic cocktail and then follow-up over 2 months in the spontaneous Winnie colitis mouse preclinical model of ulcerative colitis and also the indirect antibiotic and Winnie microbiotic gavage effects in an acute dextran sodium sulfate-induced colitis model in wild-type mice. Results: The antibiotics elicited a striking reduction in both colitis symptoms and blinded histological colitis scores, together with a convergence of the microbial taxonomy of the spontaneous colitis and wild-type control mice, toward a taxonomic phenotype usually considered to be dysbiotic. The improvement in colitis was sustained over the following 8 weeks although the microbial taxonomy changed. In vitro, fecal waters from the antibiotic-treated colitis and wild-type mice suppressed the inflammatory tenor of colonic epithelial cells, and gavaged cecal slurries from these mice moderated the acute induced colitis. Conclusion: The results clearly show the possibility of a sustained remission of colitis by microbial manipulation, which is relevant to clinical management of inflammatory bowel diseases. The beneficial effects appeared to depend on the microbial metabolome rather than its taxonomy.

Repeat and single dose administration of gadodiamide to rats to investigate concentration and location of gadolinium and the cell ultrastructure.

Gadolinium based contrast agents (GBCA) are used to image patients using magnetic resonance (MR) imaging. In recent years, there has been controversy around gadolinium retention after GBCA administration. We sought to evaluate the potential toxicity of gadolinium in the rat brain up to 1-year after repeated gadodiamide dosing and tissue retention kinetics after a single administration. Histopathological and ultrastructural transmission electron microscopy (TEM) analysis revealed no findings in rats administered a cumulative dose of 12 mmol/kg. TEM-energy dispersive X-ray spectroscopy (TEM-EDS) localization of gadolinium in the deep cerebellar nuclei showed ~ 100 nm electron-dense foci in the basal lamina of the vasculature. Laser ablation-ICP-MS (LA-ICP-MS) showed diffuse gadolinium throughout the brain but concentrated in perivascular foci of the DCN and globus pallidus with no observable tissue injury or ultrastructural changes. A single dose of gadodiamide (0.6 mmol/kg) resulted in rapid cerebrospinal fluid (CSF) and blood clearance. Twenty-weeks post administration gadolinium concentrations in brain regions was reduced by 16-72-fold and in the kidney (210-fold), testes (194-fold) skin (44-fold), liver (42-fold), femur (6-fold) and lung (64-fold). Our findings suggest that gadolinium does not lead to histopathological or ultrastructural changes in the brain and demonstrate in detail the kinetics of a human equivalent dose over time in a pre-clinical model.

COVID­19 and SARS­CoV­2 host cell entry mediators: Expression profiling of TMRSS4 in health and disease.

Severe acute respiratory syndrome (SARS) coronavirus­2 (SARS­CoV­2), the causative viral agent for the ongoing COVID­19 pandemic, enters its host cells primarily via the binding of the SARS­CoV­2 spike (S) proteins to the angiotensin­converting enzyme 2 (ACE2). A number of other cell entry mediators have also been identified, including neuropilin­1 (NRP1) and transmembrane protease serine 2 (TMPRSS2). More recently, it has been demonstrated that transmembrane protease serine 4 (TMPRSS4) along with TMPRSS2 activate the SARS­CoV­2 S proteins, and enhance the viral infection of human small intestinal enterocytes. To date, a systematic analysis of TMPRSS4 in health and disease is lacking. In the present study, using in silico tools, the gene expression and genetic alteration of TMPRSS4 were analysed across numerous tumours and compared to controls. The observations were also expanded to the level of the central nervous system (CNS). The findings revealed that TMPRSS4 was overexpressed in 11 types of cancer, including lung adenocarcinoma, lung squamous cell carcinoma, cervical squamous cell carcinoma, thyroid carcinoma, ovarian cancer, cancer of the rectum, pancreatic cancer, colon and stomach adenocarcinoma, uterine carcinosarcoma and uterine corpus endometrial carcinoma, whilst it was significantly downregulated in kidney carcinomas, acute myeloid leukaemia, skin cutaneous melanoma and testicular germ cell tumours. Finally, a high TMPRSS4 expression was documented in the olfactory tubercle, paraolfactory gyrus and frontal operculum, all brain regions which are associated with the sense of smell and taste. Collectively, these data suggest that TMPRSS4 may play a role in COVID­19 symptomatology as another SARS­CoV­2 host cell entry mediator responsible for the tropism of this coronavirus both in the periphery and the CNS.