The Impact of Extracellular Histones and Absence of Toll-like Receptors on Cardiac Functional and Electrical Disturbances in Mouse Hearts.

In polymicrobial sepsis, the extracellular histones, mainly released from activated neutrophils, significantly contribute to cardiac dysfunction (septic cardiomyopathy), as demonstrated in our previous studies using Echo-Doppler measurements. This study aims to elucidate the roles of extracellular histones and their interactions with Toll-like receptors (TLRs) in cardiac dysfunction. Through ex vivo assessments of ECG, left ventricle (LV) function parameters, and in vivo Echo-Doppler studies in mice perfused with extracellular histones, we aim to provide comprehensive insights into the mechanisms underlying sepsis-induced cardiac dysfunction. Langendorff-perfused hearts from both wild-type and TLR2, TLR3, or TLR4 knockout (KO) mice were examined. Paced mouse hearts were perfused with histones to assess contractility and relaxation. Echo-Doppler studies evaluated cardiac dysfunction after intravenous histone injection. Histone perfusion caused defects in contractility and relaxation, with TLR2 and TLR3 KO mice being partially protected. Specifically, TLR2 KO mice exhibited the greatest reduction in Echo-Doppler abnormalities, while TLR4 KO exacerbated cardiac dysfunction. Among individual histones, H1 induced the most pronounced abnormalities in cardiac function, apoptosis of cardiomyocytes, and LDH release. Our data highlight significant interactions between histones and TLRs, providing insights into histones especially H1 as potential therapeutic targets for septic cardiomyopathy. Further studies are needed to explore specific histone-TLR interactions and their mechanisms.

Evaluation of the Psychiatric Disorders among Amphetamine Addicts in Rehabilitation Centers: A Cross-Sectional Analysis.

Background: People who are addicted to amphetamines have a much greater chance of developing psychosis compared to those who are not. It is essential to study the behavioral and psychological effects of amphetamines. Therefore, this research aimed to examine conditions such as depression, anxiety, mood, cognitive abilities at the workplace, and social responsibilities by using sociodemographic factors as useful tools in determining effective strategies for preventing, managing, and treating amphetamine addiction. Methods: A cross-sectional study among addicts hospitalized at two rehabilitation centers across Saudi Arabia between May and October 2023. A validated questionnaire consisting of psychiatric disorders assessment tools was distributed to healthcare professionals to start an interview with addicts to assess the abnormalities. The results were compared with healthy people (control). The assessment tools used are Hamilton Anxiety and Depression Rating Scale, Young Mania Rating Scale, and Work and Social Adjustment Scale. The data were analyzed using SPSS version 22.0. Pearson correlation coefficients (r) were employed. Results: A total of 60 subjects participated in this study. The participants were divided into two groups (n = 60): group I was control (n = 25) healthy volunteers and group II was amphetamine abusers (n = 35), who were hospitalized for detoxification. The ages ranged from 18 to 60 years old with mean ages of 38.68 (±8.14) and 37.77 (±10.95) years in the control and amphetamine groups, respectively. Among the addicts, the mean severity dependence scale value was 10.46 (±1.82), which denotes high dependency on the illicit drug. The prevalence of high levels of anxiety, depression, and bipolar disorder was significantly higher among addicts when they were compared to healthy people (control). The assessment of the Work and Social Adjustment Scale (WSAS) reflected a higher impairment that minimized their ability to perform the work requirements, home management, social leisure, and relationships. Conclusions: The addiction to amphetamines was associated with high impairment of work performance and social obligations and a negative impact on the addict's mental health. The risk of suffering anxiety, depression, and bipolar is higher than in nonaddict people. These effects are attributed to brain damage, neurotoxicity, and neuronal inflammation, particularly when these substances are abused over extended periods and at higher doses.

Emerging Clostridioides difficile ribotypes have divergent metabolic phenotypes.

Clostridioides difficile is a gram-positive spore-forming pathogen that commonly causes diarrheal infections in the developed world. Although C. difficile is a genetically diverse species, certain ribotypes are overrepresented in human infections. It is unknown if metabolic adaptations are essential for the emergence of these epidemic ribotypes. Here, we tested carbon substrate utilization by 88 C. difficile isolates and looked for differences in growth between 22 ribotypes. By profiling clinical isolates, we assert that C. difficile is a generalist species capable of growing on a variety of carbon substrates. Further, C. difficile strains clustered by phylogenetic relationship and displayed ribotype-specific and clade-specific metabolic capabilities. Surprisingly, we observed that two emerging lineages, ribotypes 023 and 255, have divergent metabolic phenotypes. In addition, although C. difficile Clade 5 is the most evolutionary distant clade and often detected in animals, it displayed more robust growth on simple dietary sugars than Clades 1-4. Altogether, our results corroborate the generalist metabolic strategy of C. difficile and demonstrate lineage-specific metabolic capabilities. In addition, our approach can be adapted to the study of additional pathogens to ascertain their metabolic niches in the gut. IMPORTANCE: The gut pathogen Clostridioides difficile utilizes a wide range of carbon sources. Microbial communities can be rationally designed to combat C. difficile by depleting its preferred nutrients in the gut. However, C. difficile is genetically diverse with hundreds of identified ribotypes and most of its metabolic studies were performed with lab-adapted strains. Here, we profiled carbon metabolism by a myriad of C. difficile clinical isolates. While the metabolic capabilities of these isolates clustered by their genetic lineage, we observed surprising metabolic divergence between two emerging lineages. We also found that the most genetically distant clade grew robustly on simple dietary sugars, posing intriguing questions about the adaptation of C. difficile to the human gut. Altogether, our results underscore the importance of considering the metabolic diversity of pathogens in the study of their evolution and the rational design of therapeutic interventions.

Deciding on a novel predictive value to gauge how well patients with lower ureteric stones respond to medical expulsive therapy.

This study, conducted over 4 years in Baghdad, Iraq, aimed to determine the importance of ureteric jet assessment in medical expulsive therapy (MET) for distal ureteral stones. A total of 156 patients with distal ureteral stones (≤ 10 mm) participated, and their ureteric jets were observed using a color Doppler scanner before and after 2 weeks of MET. The main focus was the success rate of stone expulsion. Our results showed that 50% of patients had detectable ureteric jets after 2 weeks of MET, and 21.8% experienced successful stone expulsion. After 4 weeks, 23.7% achieved stone expulsion, while 54.5% still had remaining stones. Patients who had a positive baseline ureteric jet were significantly more likely to successfully expel their stones. This study highlights the importance of monitoring ureteric jet movement in MET for distal ureteral stones.

Comprehensive review of melatonin as a promising nutritional and nutraceutical supplement.

Background: Melatonin is an indoleamine hormone secreted by the pineal gland at night and has an essential role in regulating human circadian rhythms (the internal 24-h clock) and sleep-wake patterns. However, it has recently gained considerable attention for its demonstrated ability in disease management. This review discusses the major biological activities of melatonin, its metabolites as nutritional supplements, and its bioavailability in food sources. Methods: The information acquisition process involved conducting a comprehensive search across academic databases including PubMed, Scopus, Wiley, Embase, and Springer using relevant keywords. Only the most recent, peer-reviewed articles published in the English language were considered for inclusion. Results: The molecular mechanisms by which melatonin induces its therapeutic effects have been the subject of various studies. Conclusion: While melatonin was initially understood to only regulate circadian rhythms, recent studies indicate that it has a far-reaching effect on various organs and physiological systems, such as immunity, cardiovascular function, antioxidant defense, and lipid hemostasis. As a potent antioxidant, anti-cancer, anti-inflammatory, and immunoregulatory agent, multiple therapeutic applications have been proposed for melatonin.

Predictive Factors for Critical Weight Loss in Saudi Head and Neck Cancer Patients Undergoing (Chemo)Radiotherapy.

Weight loss is a significant health problem among patients with head and neck cancer (HNC) that is attributable primarily to the tumor or tumor therapy. Critical weight loss (CWL) is defined as the unintentional loss of ≥5% of weight. Therefore, this study's goal was to investigate and determine the possible factors influencing CWL among patients with HNC who have received radiotherapy or concurrent chemoradiotherapy (CCRT). We conducted a retrospective analysis of 175 patients who received radiotherapy or CCRT as either their primary, adjuvant, or combined treatment at the Oncology Center in King Abdullah Medical City. All patients were ≥18 years of age and diagnosed with HNC with no metastasis. The study results showed that 107 patients (61%) had CWL, while 68 (39%) did not. The following factors were significantly predictive of CWL with a multivariate regression analysis: pretreatment BMI (AOR = 1.1, 95% CI = 1.02-1.17), oral cavity cancer (AOR = 10.36, 95% CI = 1.13-94.55), and male sex (AOR = 3.15, 95% CI = 1.39-7.11). In conclusion, weight loss is highly prevalent among HNC patients during treatment. Accordingly, pretreatment BMI, cancer in the oral cavity, and being male can be considered predictive factors for CWL.

Vitamin B12 status among asymptomatic young adult females and its association with some anthropometric and biochemical parameters: A cross-sectional study from Makkah (cobalamin deficiency in young adult females).

This study was designed to measure the prevalence of vitamin B12 deficiency among young adult females in Makkah City and study its correlation with some anthropometric and biochemical indicators. A cross-sectional study and a detailed questionnaire were used to collect information from 402 young women aged 19 to 22 years, who were university students. Moreover, dietary assessments using a validated food frequency questionnaire and anthropometric measurements were performed. The mean values of serum vitamin B12, serum folate, hemoglobin, and body mass index (BMI) were 343.29 ±â€…148.16 pg/mL, 12.72 ±â€…2.62 ng/mL, 12.69 ±â€…1.41 g/dL, and 22.64 ±â€…4.24 kg/m2, respectively. About three-quarters of the study sample had normal vitamin B12 levels, while the rest had vitamin B12 deficiency. Meanwhile, a significant negative association (r = -0.201, P = .048) was found between abdominal fat and serum vitamin B12 levels. This study concluded that the young adult females' population from Makkah City is among the risk groups for vitamin B12 deficiency, which is highly correlated with inappropriate values of weight, body fat, and some blood indices. Appropriate dietary interventions and awareness are needed for this population.

The effect of bariatric surgery on dietary Behaviour, dietary recommendation Adherence, and micronutrient deficiencies one year after surgery.

Bariatric surgery (BS) is associated with vitamin and mineral deficiencies, which might be augmented by low adherence to dietary guidelines and inappropriate dietary behaviours. The aim of this study was to determine the influence of BS on eating behaviour, prevalence of nutrient deficiency, level of commitment to diet, and lifestyle recommendations one-year post-BS. A cross-sectional study was conducted among adult patients who underwent BS in 2019 and had follow-up for a year. Age, gender, and clinical data were collected from the hospital system and other information was obtained from questionnaires during phone interviews. A total of 160 patients participated in the study. At 12 months, a significant increase from the baseline values in plasma levels of vitamin B12, folate, vitamin D, iron, corrected calcium, albumin, CRP, and MCV, as well as a significant decrease in BMI was observed. Adherence to dietary and lifestyle recommendations was moderate to high. Emotional, and restrained eating behaviours were moderate with 64.4%, and 77.5%, respectively. External eating was low at 58.1%. The study concluded that pre-and post-bariatric surgery nutrients should be closely monitored.

Visceral adiposity in cirrhosis: Association with disease severity and impact of liver transplantation.

BACKGROUND: Changes in adipose tissue distribution in liver cirrhosis are poorly characterized and may affect clinical outcomes. METHODS: Adult liver transplant (LT) January 2008-August 2017 recipients with abdominal MRI within 6 months pre-LT were retrospectively assessed. Visceral adipose tissue, subcutaneous adipose tissue, and skeletal muscle area (cm2) were determined at L3. Visceral-to-subcutaneous adipose tissue ratio (VSR) was used to define relative adipose distribution, stratified by sex. Correlation was tested with Pearson. Body composition measures were compared by Child-Turcotte-Pugh (CTP) class, before and after LT, and evaluated as predictors of clinical outcomes. RESULTS: A total of 318 patients were studied. Mean age was 56 years, 33.64% were female, and 47.80% had CTP C cirrhosis. CTP C was associated with a 0.42-point increase in VSR compared with CTP A (95% CI = 0.13-0.71, p < 0.01), adjusting for age, sex, diabetes, and HCC. Among the 79 (24.84%) patients with repeat MRI 1-2 years after LT, VSR significantly improved from before LT (1.31 vs. 0.95, p < 0.01). In adjusted analysis, CTP C was associated with a 0.86-point decrease in post-LT VSR compared with pre-LT VSR (95% CI = -1.27 to -0.44, p < 0.01). Body mass index poorly correlated with VSR before and after LT. Elevated pre-LT VSR trended toward an association with a 7.17-point decrease in pre-LT glomerular filtration rate (95% CI = -14.35 to -0.02, p = 0.05), adjusting for CTP C, age, sex, diabetes, hypertension, pre-LT sarcopenia, and hepatocellular carcinoma. Elevated pre-LT VSR did not affect 3-year post-LT mortality (log-rank p = 0.24). CONCLUSIONS: Poorly represented by body mass index, visceral adiposity is increased in cirrhosis and is associated with CTP class. However, this adipose redistribution may be modifiable by LT.

EVALUATION OF ANTIOXIDANTS ENZYMES AND AUTOPHAGY GENES IN THE BLOOD OF IRAQI SMOKER VOLUNTEERS.

OBJECTIVE: The aim: In this study, we investigated the expression level of LC3A, LC3B, Beclin1, and ATG5 in the blood of smokers as well as non-smokers volunteers. On the other hand, total antioxidant status (TAS), catalase (CAT), and superoxide dismutase (SOD) in the same individuals were measured. PATIENTS AND METHODS: Material and methods: About 5 ml of blood was collected from 55 smokers (workers in a coffee shop) and 24 non-smokers volunteers. The blood was divided into two parts: 2.5 ml collected in a K2-EDTA tube that was used for RNA extraction to estimate the autophagic genes including LC3A, LC3B, Beclin1, and ATG5 by using of qRT-PCR and for hematological studies. The other part - was centrifuged to obtain the serum samples to measure TAS, CAT, and SOD by spectrophotometrical method. RESULTS: Results: The fold expression of autophagy genes was significantly increased in the blood of smokers as compared to non-smokers' individuals at (p ≤ 0.05). On the other hand, TAS, CAT, and SOD were significantly increased in smokers as compared with non-smokers individuals at (p ≤ 0.05). The hematological study revealed increased hemoglobin concentration and hematocrit in the smoker's blood as compared to nonsmokers' individuals. No significant variation was found in other hematological parameters in the smoker's individual as compared to non-smokers at (p ≤ 0.05). CONCLUSION: Conclusions: Our results indicate that smoke exposure may induce autophagy genes through increased antioxidant status and antioxidant enzymes, and the better way to be healthy is to quitting smoking.

Knowledge, attitudes, and factors associated with vegetarianism in the Saudi Population.

BACKGROUND: In recent years, there has been great interest in the dietary practices of vegetarians in addition to an increasing awareness of the potential benefits of vegetarian diets. However, there are insufficient data on the spread of vegetarianism in Arab countries. The aim of this study was to investigate knowledge and attitudes about vegetarianism and associated factors in the Saudi population and to understand the reasons for its growing prevalence. METHOD: This is a cross-sectional study began in May 2020 and ended in September 2020. Researchers distributed the questionnaire electronically through social media. Data were collected electronically and exported to Excel by the researchers .The electronic questionnaire comprised three sections: sociodemographic questions, reasons for following a vegetarian diet, and beliefs and knowledge about vegetarianism. RESULTS: There were 3,035 responses, of which 80.2% of respondents were female and 19.8% were male. Participant were aged 18-65. Vegetarians represented 37.5% (15.7% semivegetarians, 8.1% pescovegetarians, 64.3% lacto-ovo-vegetarians, and 11.3% vegans), and the rest were nonvegetarians. The majority of the vegetarian participants (92.9%) had a low vegetarianism knowledge level. Health issues, followed by ethical and environmental concerns, were the most common motivators for adopting a vegetarian diet; these reasons were cited by 72.5%, 59.3%, and 47.9% of participants, respectively. Factors associated with increased vegetarianism were engaging in exercise for half an hour to two hours, while factors associated with decreased vegetarianism were male, aged 51-64 years, being married, having a higher education, working in the health sector, being a housewife, and having an income between 5,000 and 10,000 SR/month. CONCLUSION: Vegetarianism appears to be a growing phenomenon among the Saudi population. Increased awareness of health issues and the desire to live a healthy lifestyle might be the strongest motives. This study offers an opportunity to better understand vegetarianism in Saudi Arabia along with the possibility of expanding vegetarian food choices for the general public.

THE IMMUNOPATHOGENESIS OF POLYMICROBIAL SEPSIS.

ABSTRACT: This report deals with the advances made in the areas of complement and its role in sepsis, both in mice and in humans. The study relates to work over the past 25 years (late 1990s to October 2022). During this period, there has been very rapid progress in understanding the activation pathways of complement and the activation products of complement, especially the anaphylatoxin C5a and its receptors, C5aR1 and C5aR2. Much has also been learned about these pathways of activation that trigger activation of the innate immune system and the array of strong proinflammatory cytokines that can cause cell and organ dysfunction, as well as complement products that cause immunosuppression. The work in septic humans and mice, along with patients who develop lung dysfunction caused by COVID-19, has taught us that there are many strategies for treatment of humans who are septic or develop COVID-19-related lung dysfunction. To date, treatments in humans with these disorders suggest that we are in the midst of a new and exciting area related to the complement system.

Factors associated with the prevalence of malnutrition among adult hemodialytic patients: A two-center study in the Jeddah region, Saudi Arabia.

Chronic kidney disease, one of the most common diseases in the world, is characterized by irreversible impairment of the kidney's metabolic, excretory, and endocrine functions. During end-stage renal disease, patients require renal replacement therapy, such as hemodialysis (HD). Protein-energy wasting is a common health problem among HD patients. This study aims to assess the nutritional status of HD patients at two HD centers in Jeddah, Saudi Arabia, and to determine its associated factors. A cross-sectional study was conducted at two different dialysis centers in Jeddah, Saudi Arabia; 211 female and male HD patients. Malnutrition was recognized using the modified-subjective global assessment (M-SGA) comprising two parts: medical history and physical examination. Sociodemographic and health status for all patients were also determined. Patients were classified based on their M-SGA score into two groups: normal and malnourished. Overall, 54.5% of the participants showed malnutrition. Unemployment, low muscle strength and mass, high level of medication use, and high dialysis vintage were positively (P < .05) associated with malnutrition. In conclusion, the M-SGA score indicates a high prevalence of malnutrition among HD patients. These results show the importance of regular assessment and follow-ups for HD patients ensuring better health and nutritional status.

Deferasirox and vitamin D3 co-therapy mitigates iron-induced renal injury by enhanced modulation of cellular anti-inflammatory, anti-oxidative stress, and iron regulatory pathways in rat.

BACKGROUND: Chronic iron overload could induce nephropathy via oxidative stress and inflammation, and chelating therapy has limited efficacy in removing excess intracellular iron. Although vitamin D (VD) has shown potent antioxidant and anti-inflammatory effects, as well contribute to iron homeostasis, none of the previous studies measured its potential remedial effects against chronic iron toxicity. AIMS: To measure the alleviating effects of deferasirox (DFX) and/or vitamin D (VD) single and combined therapies against nephrotoxicity induced by chronic iron overload. METHODS: Forty male rats were divided into negative (NC) and positive (PC) controls, DFX, VD, and DFX/VD groups. The designated groups received iron for six weeks followed by DFX and/or VD for another six weeks. Then, the expression pattern of renal genes and proteins including hepcidin, ferroportin (FPN), megalin, transferrin receptor 1 (TfR1), ferritin heavy and light chains, VD receptor (VDR), VD synthesizing (Cyp27b1) and catabolizing (Cyp24a1) enzymes were measured alongside serum markers of renal function and iron biochemical parameters. Additionally, several markers of oxidative stress (MDA/H2O2/GSH/SOD1/CAT/GPx4) and inflammation (IL-1ß/IL-6/TNF-α/IL-10) together with renal cell apoptosis and expression of caspase-3 (Casp-3) were measured. RESULTS: The PC rats showed pathological iron and renal biochemical markers, hypovitaminosis D, increased renal tissue iron contents with increased Cyp24a1/Megalin/ferritin-chains/hepcidin, and decreased Cyp27b1/VDR/TfR1/FPN expression than the NC group. The PC renal tissues also showed abnormal histology, increased inflammatory (IL-1ß/IL-6/TNF-α), oxidative stress (MDA/H2O2), and apoptosis markers with decreased IL-10/GSH/SOD1/CAT/GPx4. Although DFX monotherapy reduced serum iron levels, it was comparable to the PC group in renal iron concentrations, VD and iron-homeostatic molecules, alongside markers of oxidative stress, inflammation, and apoptosis. On the other hand, VD monotherapy markedly modulated renal iron and VD-related molecules, reduced renal tissue iron concentrations, and preserved renal tissue relative to the PC and DFX groups. However, serum iron levels were equal in the VD and PC groups. In contrast, the best significant improvements in serum and renal iron levels, expression of renal iron-homeostatic molecules, oxidative stress, inflammation, and apoptosis were seen in the co-therapy group. CONCLUSIONS: iron-induced nephrotoxicity was associated with dysregulations in renal VD-system together with renal oxidative stress, inflammation, and apoptosis. While DFX reduced systemic iron, VD monotherapy showed better attenuation of renal iron concentrations and tissue damage. Nonetheless, the co-therapy approach exhibited the maximal remedial effects, possibly by enhanced modulation of renal iron-homeostatic molecules alongside reducing systemic iron levels. AVAILABILITY OF DATA AND MATERIALS: All data generated or analysed during this study are included in this published article [and its Supplementary information files].

Consumption of Food Components of the Mediterranean Diet Decreases the Risk of Breast Cancer in the Makkah Region, Saudi Arabia: A Case-Control Study.

Background: Breast cancer is one of the leading causes of death worldwide, it affects both men and women. In Saudi Arabia, breast cancer has been the most prevalent type of cancer in women, for the past few years. Dietary habits and cultural beliefs vary according to region, and further studies are required to demonstrate the relationship between these dietary habits and cultural beliefs and the risk of developing breast cancer. This study is aimed to discover the relationship between preventive dietary factors of the Mediterranean diet and rates of breast cancer among postmenopausal women in the Makkah region of Saudi Arabia. Methods: A case-control study was conducted in King Abdulla Medical City Hospital, Makkah, Saudi Arabia and included 432 Saudi female participants: 218 in the control group and 214 breast cancer patients. All participants were postmenopausal, around the same age, and all were ethnically Arab Saudis. Data were obtained using a self-administered validated questionnaire. Results: Study results showed that a diet that includes 1-2 servings of legumes weekly, 1-5 servings of fish weekly, 1-5 servings of dairy products daily, 3-5 servings of fruits and vegetables daily, and more than one cup of black tea and coffee per day significantly (p < 0.05) reduces the risk of breast cancer. Conclusion: This study demonstrates that consuming a Mediterranean diet, which includes legumes, fish, fruits and vegetables, black tea, coffee, and low intake of dairy products, works as a preventive factor against breast cancer in postmenopausal females from the Makkah region.

Corrigendum: Consumption of Food Components of the Mediterranean Diet Decreases the Risk of Breast Cancer in the Makkah Region, Saudi Arabia: A Case-Control Study.

[This corrects the article DOI: 10.3389/fnut.2022.863029.].

Systems biology approach to functionally assess the Clostridioides difficile pangenome reveals genetic diversity with discriminatory power.

Combatting Clostridioides difficile infections, a dominant cause of hospital-associated infections with incidence and resulting deaths increasing worldwide, is complicated by the frequent emergence of new virulent strains. Here, we employ whole-genome sequencing, high-throughput phenotypic screenings, and genome-scale models of metabolism to evaluate the genetic diversity of 451 strains of C. difficile. Constructing the C. difficile pangenome based on this set revealed 9,924 distinct gene clusters, of which 2,899 (29%) are defined as core, 2,968 (30%) are defined as unique, and the remaining 4,057 (41%) are defined as accessory. We develop a strain typing method, sequence typing by accessory genome (STAG), that identifies 176 genetically distinct groups of strains and allows for explicit interrogation of accessory gene content. Thirty-five strains representative of the overall set were experimentally profiled on 95 different nutrient sources, revealing 26 distinct growth profiles and unique nutrient preferences; 451 strain-specific genome scale models of metabolism were constructed, allowing us to computationally probe phenotypic diversity in 28,864 unique conditions. The models create a mechanistic link between the observed phenotypes and strain-specific genetic differences and exhibit an ability to correctly predict growth in 76% of measured cases. The typing and model predictions are used to identify and contextualize discriminating genetic features and phenotypes that may contribute to the emergence of new problematic strains.

Gut Microbiota From Sjögren syndrome Patients Causes Decreased T Regulatory Cells in the Lymphoid Organs and Desiccation-Induced Corneal Barrier Disruption in Mice.

Sjögren syndrome (SS) is an autoimmune inflammatory disorder characterized by secretory dysfunction in the eye and mouth; in the eye, this results in tear film instability, reduced tear production, and corneal barrier disruption. A growing number of studies show that homeostasis of the ocular surface is impacted by the intestinal microbiome, and several 16S sequencing studies have demonstrated dysbiosis of the intestinal microbiota in SS patients. In this study, we utilized metagenomic sequencing to perform a deeper analysis of the intestinal microbiome using stools collected from sex- and age-matched healthy (n = 20), dry eye (n = 4) and SS (n = 7) subjects. The observed Operational Taxonomic Units (OTUs) and Shannon alpha diversity were significantly decreased in SS compared to healthy controls, and there was a significant inverse correlation between observed OTUs and ocular severity score. We also identified specific bacterial strains that are differentially modulated in SS vs. healthy subjects. To investigate if the differential composition of intestinal microbiome would have an impact on the immune and eye phenotype, we performed functional studies using germ-free mice colonized with human intestinal microbiota from SS patients and healthy controls. Flow cytometry analysis demonstrated reduced frequency of CD4+ FOXP3+ cells in ocular draining cervical lymph nodes (CLN) in mice colonized with SS patient intestinal microbiota 4 weeks post-colonization. We also found that offspring of SS-humanized mice also have fewer CD4+FOXP3+ cells in the CLN as well as spleen, demonstrating vertical transmission. SS-humanized mice subjected to desiccating stress exhibited greater corneal barrier disruption as compared to healthy control humanized mice under the same conditions. Taken together, these data support the hypothesis that the intestinal microbiota can modulate ocular surface health, possibly by influencing development of CD4+ FOXP3+ regulatory T cells (Tregs) in the ocular draining lymph nodes.

Impact of a human gut microbe on Vibrio cholerae host colonization through biofilm enhancement.

Recent studies indicate that the human intestinal microbiota could impact the outcome of infection by Vibrio cholerae, the etiological agent of the diarrheal disease cholera. A commensal bacterium, Paracoccus aminovorans, was previously identified in high abundance in stool collected from individuals infected with V. cholerae when compared to stool from uninfected persons. However, if and how P. aminovorans interacts with V. cholerae has not been experimentally determined; moreover, whether any association between this bacterium alters the behaviors of V. cholerae to affect the disease outcome is unclear. Here, we show that P. aminovorans and V. cholerae together form dual-species biofilm structure at the air-liquid interface, with previously uncharacterized novel features. Importantly, the presence of P. aminovorans within the murine small intestine enhances V. cholerae colonization in the same niche that is dependent on the Vibrio exopolysaccharide and other major components of mature V. cholerae biofilm. These studies illustrate that multispecies biofilm formation is a plausible mechanism used by a gut microbe to increase the virulence of the pathogen, and this interaction may alter outcomes in enteric infections.

Static and Dynamic Measurements of Compliance and Driving Pressure: A Pilot Study.

RATIONALE: Monitoring tidal cycle mechanics is key to lung protection. For this purpose, compliance and driving pressure of the respiratory system are often measured clinically using the plateau pressure, obtained after imposing an extended end-inspiratory pause, which allows for relaxation of the respiratory system and redistribution of inflation volume (method A). Alternative methods for estimating compliance and driving pressure utilize the measured pressure at the earliest instance of zero flow (method B), the inspiratory slope of the pressure-time tracing during inflation with constant flow (method C), and the expiratory time constant (method D). METHODS: Ten passive mechanically ventilated subjects, at a large tertiary referral center, underwent measurements of compliance and driving pressure using the four different methods. The inspiratory tidal volume, inspiratory to expiratory ratio, and positive end expiratory pressures were then adjusted from baseline and the measurements re-obtained. RESULTS: Method A yielded consistently higher compliance and lower driving pressure calculations compared to methods B and C. Methods B and C most closely approximated one another. Method D did not yield a consistent reliable pattern. CONCLUSION: Static measurements of compliance and driving pressure using the plateau pressure may underestimate the maximum pressure experienced by the most vulnerable lung units during dynamic inflation. Utilizing the pressure at zero flow as a static measurement, or the inspiratory slope as a dynamic measurement, may calculate a truer estimate of the maximum alveolar pressure that generates stress upon compromised lung units.