Global compositional and functional states of the human gut microbiome in health and disease.

The human gut microbiota is of increasing interest, with metagenomics a key tool for analyzing bacterial diversity and functionality in health and disease. Despite increasing efforts to expand microbial gene catalogs and an increasing number of metagenome-assembled genomes, there have been few pan-metagenomic association studies and in-depth functional analyses across different geographies and diseases. Here, we explored 6014 human gut metagenome samples across 19 countries and 23 diseases by performing compositional, functional cluster, and integrative analyses. Using interpreted machine learning classification models and statistical methods, we identified Fusobacterium nucleatum and Anaerostipes hadrus with the highest frequencies, enriched and depleted, respectively, across different disease cohorts. Distinct functional distributions were observed in the gut microbiomes of both westernized and nonwesternized populations. These compositional and functional analyses are presented in the open-access Human Gut Microbiome Atlas, allowing for the exploration of the richness, disease, and regional signatures of the gut microbiota across different cohorts.

Clinical, experimental and pathophysiological effects of Yaq-001: a non-absorbable, gut-restricted adsorbent in models and patients with cirrhosis.

OBJECTIVE: Targeting bacterial translocation in cirrhosis is limited to antibiotics with risk of antimicrobial resistance. This study explored the therapeutic potential of a non-absorbable, gut-restricted, engineered carbon bead adsorbent, Yaq-001 in models of cirrhosis and acute-on-chronic liver failure (ACLF) and, its safety and tolerability in a clinical trial in cirrhosis. DESIGN: Performance of Yaq-001 was evaluated in vitro. Two-rat models of cirrhosis and ACLF, (4 weeks, bile duct ligation with or without lipopolysaccharide), receiving Yaq-001 for 2 weeks; and two-mouse models of cirrhosis (6-week and 12-week carbon tetrachloride (CCl4)) receiving Yaq-001 for 6 weeks were studied. Organ and immune function, gut permeability, transcriptomics, microbiome composition and metabolomics were analysed. The effect of faecal water on gut permeability from animal models was evaluated on intestinal organoids. A multicentre, double-blind, randomised, placebo-controlled clinical trial in 28 patients with cirrhosis, administered 4 gr/day Yaq-001 for 3 months was performed. RESULTS: Yaq-001 exhibited rapid adsorption kinetics for endotoxin. In vivo, Yaq-001 reduced liver injury, progression of fibrosis, portal hypertension, renal dysfunction and mortality of ACLF animals significantly. Significant impact on severity of endotoxaemia, hyperammonaemia, liver cell death, systemic inflammation and organ transcriptomics with variable modulation of inflammation, cell death and senescence in the liver, kidneys, brain and colon was observed. Yaq-001 reduced gut permeability in the organoids and impacted positively on the microbiome composition and metabolism. Yaq-001 regulated as a device met its primary endpoint of safety and tolerability in the clinical trial. CONCLUSIONS: This study provides strong preclinical rationale and safety in patients with cirrhosis to allow clinical translation. TRIAL REGISTRATION NUMBER: NCT03202498.

Rifaximin-α reduces gut-derived inflammation and mucin degradation in cirrhosis and encephalopathy: RIFSYS randomised controlled trial.

BACKGROUND & AIMS: Rifaximin-α is efficacious for the prevention of recurrent hepatic encephalopathy (HE), but its mechanism of action remains unclear. We postulated that rifaximin-α reduces gut microbiota-derived endotoxemia and systemic inflammation, a known driver of HE. METHODS: In a placebo-controlled, double-blind, mechanistic study, 38 patients with cirrhosis and HE were randomised 1:1 to receive either rifaximin-α (550 mg BID) or placebo for 90 days. PRIMARY OUTCOME: 50% reduction in neutrophil oxidative burst (OB) at 30 days. SECONDARY OUTCOMES: changes in psychometric hepatic encephalopathy score (PHES) and neurocognitive functioning, shotgun metagenomic sequencing of saliva and faeces, plasma and faecal metabolic profiling, whole blood bacterial DNA quantification, neutrophil toll-like receptor (TLR)-2/4/9 expression and plasma/faecal cytokine analysis. RESULTS: Patients were well-matched: median MELD (11 rifaximin-α vs. 10 placebo). Rifaximin-α did not lead to a 50% reduction in spontaneous neutrophil OB at 30 days compared to baseline (p = 0.48). However, HE grade normalised (p = 0.014) and PHES improved (p = 0.009) after 30 days on rifaximin-α. Rifaximin-α reduced circulating neutrophil TLR-4 expression on day 30 (p = 0.021) and plasma tumour necrosis factor-α (TNF-α) (p <0.001). Rifaximin-α suppressed oralisation of the gut, reducing levels of mucin-degrading sialidase-rich species, Streptococcus spp, Veillonella atypica and parvula, Akkermansia and Hungatella. Rifaximin-α promoted a TNF-α- and interleukin-17E-enriched intestinal microenvironment, augmenting antibacterial responses to invading pathobionts and promoting gut barrier repair. Those on rifaximin-α were less likely to develop infection (odds ratio 0.21; 95% CI 0.05-0.96). CONCLUSION: Rifaximin-α led to resolution of overt and covert HE, reduced the likelihood of infection, reduced oralisation of the gut and attenuated systemic inflammation. Rifaximin-α plays a role in gut barrier repair, which could be the mechanism by which it ameliorates bacterial translocation and systemic endotoxemia in cirrhosis. CLINICAL TRIAL NUMBER: ClinicalTrials.gov NCT02019784. LAY SUMMARY: In this clinical trial, we examined the underlying mechanism of action of an antibiotic called rifaximin-α which has been shown to be an effective treatment for a complication of chronic liver disease which effects the brain (termed encephalopathy). We show that rifaximin-α suppresses gut bacteria that translocate from the mouth to the intestine and cause the intestinal wall to become leaky by breaking down the protective mucus barrier. This suppression resolves encephalopathy and reduces inflammation in the blood, preventing the development of infection.

Exaggerated inflammatory response to bacterial products in decompensated cirrhotic patients is orchestrated by interferons IL-6 and IL-8.

Cirrhosis-associated immune dysfunction (CAID) contributes to disease progression and organ failure development. We interrogated immune system function in nonseptic compensated and decompensated cirrhotic patients using the TruCulture whole blood stimulation system, a novel technique that allows a more accurate representation than traditional methods, such as peripheral blood mononuclear cell culture, of the immune response in vivo. Thirty cirrhotics (21 decompensated and 9 compensated) and seven healthy controls (HCs) were recruited. Whole blood was drawn directly into three TruCulture tubes [unstimulated to preloaded with heat-killed Escherichia coli 0111:B4 (HKEB) or lipopolysaccharide (LPS)] and incubated in dry heat blocks at 37°C for 24 h. Cytokine analysis of the supernatant was performed by multiplex assay. Cirrhotic patients exhibited a robust proinflammatory response to HKEB compared with HCs, with increased production of interferon-γ-induced protein 10 (IP-10) and IFN-λ1, and to LPS, with increased production of IFN-λ1. Decompensated patients demonstrated an augmented immune response compared with compensated patients, orchestrated by an increase in type I, II, and III interferons, and higher levels of IL-1ß, IL-6, and IL-8 post-LPS stimulation. IL-1ß, TNF-α, and IP-10 post-HKEB stimulation and IP-10 post-LPS stimulation negatively correlated with biochemical markers of liver disease severity and liver disease severity scores. Cirrhotic patients exposed to bacterial products exhibit an exaggerated inflammatory response orchestrated by IFNs, IL-6, and IL-8. Poststimulation levels of a number of proinflammatory cytokines negatively correlate with markers of liver disease severity raising the possibility that the switch to an immunodeficient phenotype in CAID may commence earlier in the course of advanced liver disease. NEW & NOTEWORTHY Decompensated cirrhotic patients, compared with compensated patients, exhibit a greater exaggerated inflammatory response to bacterial products orchestrated by interferons, IL-6, and IL-8. Postbacterial product stimulation levels of a number of pro-inflammatory cytokines negatively correlate with liver disease severity biomarkers and liver disease severity scores raising the possibility that the switch to an immunodeficient phenotype in cirrhosis-associated immune dysfunction may commence earlier in the course of advanced liver disease.

Targeting the gut-liver-immune axis to treat cirrhosis.

Cirrhotic portal hypertension is characterised by development of the decompensating events of ascites, encephalopathy, portal hypertensive bleeding and hepatorenal syndrome, which arise in a setting of cirrhosis-associated immune dysfunction (CAID) and define morbidity and prognosis. CAID describes the dichotomous observations that systemic immune cells are primed and display an inflammatory phenotype, while failing to mount robust responses to pathogen challenge. Bacterial infections including spontaneous bacterial peritonitis are common complications of advanced chronic liver disease and can precipitate variceal haemorrhage, hepatorenal syndrome and acute-on-chronic liver failure; they frequently arise from gut-derived organisms and are closely linked with dysbiosis of the commensal intestinal microbiota in advanced chronic liver disease.Here, we review the links between cirrhotic dysbiosis, intestinal barrier dysfunction and deficits of host-microbiome compartmentalisation and mucosal immune homoeostasis that occur in settings of advanced chronic liver disease. We discuss established and emerging therapeutic strategies targeted at restoring intestinal eubiosis, augmenting gut barrier function and ameliorating the mucosal and systemic immune deficits that characterise and define the course of decompensated cirrhosis.

Understanding young adults' reasons for seeking 'clinically unnecessary' urgent and emergency care: A qualitative interview study.

BACKGROUND: Studies have identified young adults as more likely to use emergency departments for 'clinically unnecessary' problems, with limited similar evidence for emergency ambulance use. Media portrayals depict young adults as motivated by 'convenience', but little research has explored the reasons for their help-seeking behaviour. METHODS: Qualitative interviews with 16 young adults (18-30) considered by clinicians to have made unnecessary use of emergency ambulance, emergency department or an urgent GP appointment. Data analysis was informed by interpretive phenomenological analysis. FINDINGS: A number of interrelated factors contributed to participants' decisions. They were anxious about the seriousness of their symptoms, sometimes exacerbated by reduced coping capacity due to poor mental health or life stresses. They looked to others to facilitate their decision making, who sometimes encouraged urgent contact. They wanted to avoid impact on existing day-to-day commitments including work or study. They had strong views about different health services, sometimes based on frustration with lack of resolution of on-going health problems. Convenience was not identified as a significant factor, although some actions could be interpreted in this light if the context was not considered. CONCLUSIONS: Young adults make 'clinically unnecessary' use of urgent and emergency care for more than convenience. Their decisions need to be understood in relation to the complexity of their experience, including lack of confidence in making health-related decisions, lowered coping capacity and concern to maintain normal daily life.

Chronic Rejection of Cardiac Allografts Is Associated With Increased Lymphatic Flow and Cellular Trafficking.

BACKGROUND: Cardiac transplantation is an excellent treatment for end-stage heart disease. However, rejection of the donor graft, in particular, by chronic rejection leading to cardiac allograft vasculopathy, remains a major cause of graft loss. The lymphatic system plays a crucial role in the alloimmune response, facilitating trafficking of antigen-presenting cells to draining lymph nodes. The encounter of antigen-presenting cells with T lymphocytes in secondary lymphoid organs is essential for the initiation of alloimmunity. Donor lymphatic vessels are not anastomosed to that of the recipient during transplantation. The pathophysiology of lymphatic disruption is unknown, and whether this disruption enhances or hinders the alloimmune responses is unclear. Although histological analysis of lymphatic vessels in donor grafts can yield information on the structure of the lymphatics, the function following cardiac transplantation is poorly understood. METHODS: Using single-photon emission computed tomography/computed tomography lymphoscintigraphy, we quantified the lymphatic flow index following heterotrophic cardiac transplantation in a murine model of chronic rejection. RESULTS: Ten weeks following transplantation of a minor antigen (HY) sex-mismatched heart graft, the lymphatic flow index was significantly increased in comparison with sex-matched controls. Furthermore, the enhanced lymphatic flow index correlated with an increase in donor cells in the mediastinal draining lymph nodes; increased lymphatic vessel area; and graft infiltration of CD4+, CD8+ T cells, and CD68+ macrophages. CONCLUSIONS: Chronic rejection results in increased lymphatic flow from the donor graft to draining lymph nodes, which may be a factor in promoting cellular trafficking, alloimmunity, and cardiac allograft vasculopathy.

Treatment of caffeine toxicity with metoprolol.

A 27-year-old man presented with an intentional overdose of concentrated caffeine powder that he bought over the internet. The patient received benzodiazepines and ondansetron for symptomatic treatment when he arrived in the Emergency Department (ED). Subsequently, he developed recurrent supraventricular tachycardia in the ED. The SVT was successfully treated with metoprolol. The patient's caffeine level was >90 mg/L. This is the first known report of treatment of caffeine-induced supraventricular tachycardia with metoprolol.

Risk factors for negative experiences during psychotherapy.

BACKGROUND: It is estimated that between 3% and 15% of patients have a negative experience of psychotherapy, but little is understood about this. AIMS: The aim of this study was to investigate the factors associated with patients' negative therapy experiences. METHOD: The data comprised 185 patient and 304 therapist questionnaires, 20 patient and 20 therapist interviews. Patients reported on an unhelpful or harmful experience of therapy, and therapists on a therapy where they thought the patient they were working with had a poor or harmful experience. These were transcribed and analysed using thematic analysis. RESULTS: There was a Lack of fit between Patient needs, Therapist skills, and Service structures. This could result in Fault Lines, a tension between Safety and containment and Power and control. This tension led to Strain and Poor Engagement, which led to Consequences following the negative therapy experience. CONCLUSIONS: Patients require clear information, choice, involvement in decision-making, explicit contracting and clarity about sessions and progress. Opportunities for patient feedback should be the norm, where the therapist and service are vigilant for signs of deterioration and solutions considered. Clinical and methodological significance of this article: Estimates of "unwanted effects," including long-lasting effects, of psychotherapy have ranged from 3% to 15%. Few empirical studies have been conducted in this area. This study aimed to address this gap and provide clinicians with a model of risk factors for negative therapy effects. The findings of this study indicate the importance of providing patients with a supportive service structure that offers clear information, choice and involvement in decision-making. Explicit contracting at the beginning of therapy and clarity about sessions and progress are also important in managing patient expectations throughout. Opportunities for patient feedback should be provided.

Understanding Theory of Mind in Deaf and Hearing College Students.

Theory of Mind-the understanding that people have thoughts, wants, and beliefs that influence their interpersonal behavior-is an aspect of social cognition that develops with consistent, increasing complexity across age groups, languages, and cultures. Observed delays in theory of mind development among deaf children and others has led to a conversational account of theory of mind development and its delays in terms of the nature and amount of social communication experienced by children directly (conversationally) and indirectly (via overhearing). The present study explored theory of mind in deaf young adults by evaluating their understanding of sarcasm and advanced false belief (second-order false belief and double bluff), as well as related cognitive abilities. Consistent with previous studies, deaf participants scored significantly below hearing peers on all three theory of mind tasks. Performance was unrelated to their having had early access to social communication via either sign language (from deaf parents) or spoken language (through cochlear implants), suggesting that deaf participants' performance was not solely a function of access to social communication in early childhood. The finding of different predictors of theory of mind performance for deaf and hearing groups is discussed in terms of its language, social, and cognitive foundations.

Therapeutic plasma exchange as a novel treatment for severe intrahepatic cholestasis of pregnancy: Case series and mechanism of action.

INTRODUCTION: Intrahepatic cholestasis of pregnancy is characterised by pruritus and elevated serum bile acids. The pruritus can be severe, and pharmacological options achieve inconsistent symptomatic improvement. Raised bile acids are linearly associated with adverse fetal outcomes, with existing management of limited benefit. We hypothesised that therapeutic plasma exchange removes pruritogens and lowers total bile acid concentrations, and improves symptoms and biochemical abnormalities in severe cases that have not responded to other treatments. METHODS: Four women with severe pruritus and hypercholanemia were managed with therapeutic plasma exchange. Serial blood biochemistry and visual analogue scores of itch severity were obtained. Blood and waste plasma samples were collected before and after exchange; individual bile acids and sulfated progesterone metabolites were measured with HPLC-MS, autotaxin activity and cytokine profiles with enzymatic methods. Results were analysed using segmental linear regression to describe longitudinal trends, and ratio t tests. RESULTS: Total bile acids and visual analogue itch scores demonstrated trends to transiently improve following plasma exchange, with temporary symptomatic benefit reported. Individual bile acids (excluding the drug ursodeoxycholic acid), and the sulfated metabolites of progesterone reduced following exchange (P = .03 and P = .04, respectively), whilst analysis of waste plasma demonstrated removal of autotaxin and cytokines. CONCLUSIONS: Therapeutic plasma exchange can lower potentially harmful bile acids and improve itch, likely secondary to the demonstrated removal of pruritogens. However, the limited current experience and potential complications, along with minimal sustained symptomatic benefit, restrict its current use to women with the most severe disease for whom other treatment options have been exhausted.

Importance of bacterial replication and alveolar macrophage-independent clearance mechanisms during early lung infection with Streptococcus pneumoniae.

Although the importance of alveolar macrophages for host immunity during early Streptococcus pneumoniae lung infection is well established, the contribution and relative importance of other innate immunity mechanisms and of bacterial factors are less clear. We have used a murine model of S. pneumoniae early lung infection with wild-type, unencapsulated, and para-amino benzoic acid auxotroph mutant TIGR4 strains to assess the effects of inoculum size, bacterial replication, capsule, and alveolar macrophage-dependent and -independent clearance mechanisms on bacterial persistence within the lungs. Alveolar macrophage-dependent and -independent (calculated indirectly) clearance half-lives and bacterial replication doubling times were estimated using a mathematical model. In this model, after infection with a high-dose inoculum of encapsulated S. pneumoniae, alveolar macrophage-independent clearance mechanisms were dominant, with a clearance half-life of 24 min compared to 135 min for alveolar macrophage-dependent clearance. In addition, after a high-dose inoculum, successful lung infection required rapid bacterial replication, with an estimated S. pneumoniae doubling time of 16 min. The capsule had wide effects on early lung clearance mechanisms, with reduced half-lives of 14 min for alveolar macrophage-independent and 31 min for alveolar macrophage-dependent clearance of unencapsulated bacteria. In contrast, with a lower-dose inoculum, the bacterial doubling time increased to 56 min and the S. pneumoniae alveolar macrophage-dependent clearance half-life improved to 42 min and was largely unaffected by the capsule. These data demonstrate the large effects of bacterial factors (inoculum size, the capsule, and rapid replication) and alveolar macrophage-independent clearance mechanisms during early lung infection with S. pneumoniae.

The association between visual, nonverbal cognitive abilities and speech, phonological processing, vocabulary and reading outcomes in children with cochlear implants.

OBJECTIVES: The aim of this study was to explore the possibility that specific nonverbal, visual cognitive abilities may be associated with outcomes after pediatric cochlear implantation. The study therefore examined the relationship between visual sequential memory span and visual sequential reasoning ability, and a range of speech, phonological processing, vocabulary knowledge, and reading outcomes in children with cochlear implants. DESIGN: A cross-sectional, correlational design was used. Sixty-six children aged 5 to 12 years completed tests of visual memory span and visual sequential reasoning, along with tests of speech intelligibility, phonological processing, vocabulary knowledge, and word reading ability (the outcome variables). Auditory memory span was also assessed, and its relationship with the other variables examined. RESULTS: Significant, positive correlations were found between the visual memory and reasoning tests, and each of the outcome variables. A series of regression analyses then revealed that for all the outcome variables, after variance attributable to the age at implantation was accounted for, visual memory span and visual sequential reasoning ability together accounted for significantly more variance (up to 25%) in each outcome measure. CONCLUSIONS: These findings have both clinical and theoretical implications. Clinically, the findings may help improve the identification of children at risk of poor progress after implantation earlier than has been possible to date as the nonverbal tests can be administered to children as young as 2 years of age. The results may also contribute to the identification of children with specific learning or language difficulties as well as improve our ability to develop intervention strategies for individual children based on their specific cognitive processing strengths or difficulties. Theoretically, these results contribute to the growing body of knowledge about learning and development in deaf children with cochlear implants.

The delivery of creative socially prescribed activities for people with serious mental health needs during lockdown: Learning about remote, digital and hybrid delivery.

BACKGROUND: Social prescribing interventions connect mental health service users to community resources, to support physical and mental wellbeing and promote recovery. COVID-19 restrictions impacted the delivery of socially prescribed activities, preventing face to face contact for long periods. AIMS: The aim of this study was to understand how Voluntary Community and Social Enterprise (VCSE) organisations working with a local NHS mental health Trust responded to the challenges of social distancing during the COVID-19 pandemic. This understanding will be used to make recommendations for future practice, post-lockdown. METHODS: Using a convergent mixed methods design, we surveyed VCSE providers of socially prescribed activities intended to be accessible and appropriate for people with severe mental health needs. Follow-up interviews explored further how they adapted during the first year of the pandemic, the challenges they faced, and how they sought to overcome them. The survey and interview data were analysed separately and then compared to identify convergent and divergent findings. RESULTS: Twenty VCSE representatives completed the survey which provided a snapshot of changes in levels of connection and numbers reached during lockdown. Of 20 survey respondents, 11 participated in follow-up interviews. Interviews revealed that lockdown necessitated rapid change and responsive adaptation; activities were limited by resource, funding, safeguarding and government restrictions; no single format suited all group members; connection was key; and impact was difficult to gauge. CONCLUSIONS: VCSE organisations commissioned to deliver creative socially prescribed activities during the pandemic rapidly adapted their offer to comply with government restrictions. Responsive changes were made, and new knowledge and skills were gained. Drawing on experiences during lockdown, VCSE organisations should develop bespoke knowledge, skills and practices to engage service users in future hybrid delivery of arts, sports, cultural and creative community activities, and to ensure that digital activities offer an equivalent degree of connection to face-to-face ones. Additionally, more effective methods of gaining feedback about patient experience of hybrid delivery is needed.

Classical and novel psychoactive substances: rethinking drug misuse from an evolutionary psychiatric perspective.

In this article, ontogenetic and phylogenetic causes of drug abuse and links to human emotional development are considered. Some evolutionary perspectives (e.g. that under certain conditions, consumption of otherwise toxic alkaloids may confer both physical and cultural advantages) are reviewed. As described in the 'mismatch theory', the capacity of the human genome to evolve defences against toxins has been outstripped by the pace of cultural change and technological development, such as purposeful fermentation of alcohol and more recently distillation of alcohol; purification and chemical manipulation of plant alkaloids; and the engineering of entirely novel psychoactive substances (NPS). The functions of the neurobiological substrates that mediate substance misuse and dependence are reviewed. Reasons are given why NPSs present greater cause for concern than plant-derived substances of abuse. We argue that evolutionary biology provides an important orientation for the research agenda in substance misuse.

Modulation of the Gut Microbiota to Control Antimicrobial Resistance (AMR)-A Narrative Review with a Focus on Faecal Microbiota Transplantation (FMT).

Antimicrobial resistance (AMR) is one of the greatest challenges facing humanity, causing a substantial burden to the global healthcare system. AMR in Gram-negative organisms is particularly concerning due to a dramatic rise in infections caused by extended-spectrum beta-lactamase and carbapenemase-producing Enterobacterales (ESBL and CPE). These pathogens have limited treatment options and are associated with poor clinical outcomes, including high mortality rates. The microbiota of the gastrointestinal tract acts as a major reservoir of antibiotic resistance genes (the resistome), and the environment facilitates intra and inter-species transfer of mobile genetic elements carrying these resistance genes. As colonisation often precedes infection, strategies to manipulate the resistome to limit endogenous infections with AMR organisms, as well as prevent transmission to others, is a worthwhile pursuit. This narrative review presents existing evidence on how manipulation of the gut microbiota can be exploited to therapeutically restore colonisation resistance using a number of methods, including diet, probiotics, bacteriophages and faecal microbiota transplantation (FMT).

So You Want to Build Your Disease's First Online Patient Registry: An Educational Guide for Patient Organizations Based on US and European Experience.

Patient registries fulfill a number of key roles for clinicians, researchers, non-profit organizations, payers, and policy makers. They can help the field understand the natural history of a condition, determine the effectiveness of interventions, measure safety, and audit the quality of care provided. Successful registries in cystic fibrosis, Duchenne's muscular dystrophy, and other rare diseases have become a model for accelerating progress. However, the complex tasks required to develop a modern registry can seem overwhelming, particularly for those who are not from a technical background. In this Education article, a team of co-authors from across patient advocacy, technology, privacy, and commercial perspectives who have worked on a number of such projects offer a "Registry 101" primer to help get started. We will outline the promise and potential of patient registries with worked case examples, identify some of the key technical considerations you will need to consider, describe the type of data you might want to collect, consider privacy risks to protect your users, sketch out some of the paths towards long-term financial sustainability we have observed, and conclude with plans to mitigate some of the challenges that can occur and signpost interested readers to further resources. While rapid growth in the digital health market has presented numerous opportunities to those at the beginning of their journey, it is important to start with the long-term goals in mind and to benefit from the learnings of those who have walked this path before.

Characterization of a new mouse model of empyema and the mechanisms of pleural invasion by Streptococcus pneumoniae.

Although empyema affects more than 65,000 people each year in the United States and in the United Kingdom, there are limited data on the pathogenesis of pleural infection. We investigated the pathogenesis of empyema using animal and cell culture models of Streptococcus pneumoniae infection. The pathological processes during the development of empyema associated with murine pneumonia due to S. pneumoniae (strain D39) were investigated. Lungs were examined using histology, and pleural fluid and blood bacterial colony-forming units, cytokine levels, and cellular infiltrate were determined over time. Bacterial migration across mesothelial monolayers was investigated using cell culture techniques, flow cytometry, and confocal microscopy. After intranasal inoculation with 10(7) S. pneumoniae D39 strain, mice developed pneumonia associated with rapid bacterial invasion of the pleural space; raised intrapleural IL-8, VEGF, MCP-1, and TNF-α levels; and caused significant intrapleural neutrophilia followed by the development of fibrinous pleural adhesions. Bacterial clearance from the pleural space was poor, and in vitro assays demonstrated that S. pneumoniae crossed mesothelial layers by translocation through cells rather than by a paracellular route. This study describes key events during the development of S. pneumoniae empyema using a novel murine model of pneumonia-associated empyema that closely mimics human disease. The model allows for future assessment of molecular mechanisms involved in the development of empyema and evaluation of potential new therapies. The data suggest that transmigration of bacteria through mesothelial cells could be important in empyema development. Furthermore, upon entry the pleural cavity offers a protected compartment for the bacteria.

Verbal and spatial analogical reasoning in deaf and hearing children: the role of grammar and vocabulary.

The extent to which cognitive development and abilities are dependent on language remains controversial. In this study, the analogical reasoning skills of deaf and hard of hearing children are explored. Two groups of children (deaf and hard of hearing children with either cochlear implants or hearing aids and hearing children) completed tests of verbal and spatial analogical reasoning. Their vocabulary and grammar skills were also assessed to provide a measure of language attainment. Results indicated significant differences between the deaf and hard of hearing children (regardless of type of hearing device) and their hearing peers on vocabulary, grammar, and verbal reasoning tests. Regression analyses revealed that in the group of deaf and hard of hearing children, but not in the hearing group, the language measures were significant predictors of verbal analogical reasoning, when age and spatial analogical reasoning ability were controlled for. The implications of these findings are discussed.