Hyperspectral imaging and dynamic region of interest tracking approaches to quantify localized cAMP signals.

Cyclic adenosine monophosphate (cAMP) is a ubiquitous second messenger known to orchestrate a myriad of cellular functions over a wide range of timescales. In the last 20 years, a variety of single-cell sensors have been developed to measure second messenger signals including cAMP, Ca2+, and the balance of kinase and phosphatase activities. These sensors utilize changes in fluorescence emission of an individual fluorophore or Förster resonance energy transfer (FRET) to detect changes in second messenger concentration. cAMP and kinase activity reporter probes have provided powerful tools for the study of localized signals. Studies relying on these and related probes have the potential to further revolutionize our understanding of G protein-coupled receptor signaling systems. Unfortunately, investigators have not been able to take full advantage of the potential of these probes due to the limited signal-to-noise ratio of the probes and the limited ability of standard epifluorescence and confocal microscope systems to simultaneously measure the distributions of multiple signals (e.g. cAMP, Ca2+, and changes in kinase activities) in real time. In this review, we focus on recently implemented strategies to overcome these limitations: hyperspectral imaging and adaptive thresholding approaches to track dynamic regions of interest (ROI). This combination of approaches increases signal-to-noise ratio and contrast, and allows identification of localized signals throughout cells. These in turn lead to the identification and quantification of intracellular signals with higher effective resolution. Hyperspectral imaging and dynamic ROI tracking approaches offer investigators additional tools with which to visualize and quantify multiplexed intracellular signaling systems.

Cytotoxic tau released from lung microvascular endothelial cells upon infection with Pseudomonas aeruginosa promotes neuronal tauopathy.

Patients who recover from nosocomial pneumonia oftentimes exhibit long-lasting cognitive impairment comparable with what is observed in Alzheimer's disease patients. We previously hypothesized that the lung endothelium contributes to infection-related neurocognitive dysfunction, because bacteria-exposed endothelial cells release a form(s) of cytotoxic tau that is sufficient to impair long-term potentiation in the hippocampus. However, the full-length lung and endothelial tau isoform(s) have yet to be resolved and it remains unclear whether the infection-induced endothelial cytotoxic tau triggers neuronal tau aggregation. Here, we demonstrate that lung endothelial cells express a big tau isoform and three additional tau isoforms that are similar to neuronal tau, each containing four microtubule-binding repeat domains, and that tau is expressed in lung capillaries in vivo. To test whether infection elicits endothelial tau capable of causing transmissible tau aggregation, the cells were infected with Pseudomonas aeruginosa. The infection-induced tau released from endothelium into the medium-induced neuronal tau aggregation in reporter cells, including reporter cells that express either the four microtubule-binding repeat domains or the full-length tau. Infection-induced release of pathological tau variant(s) from endothelium, and the ability of the endothelial-derived tau to cause neuronal tau aggregation, was abolished in tau knockout cells. After bacterial lung infection, brain homogenates from WT mice, but not from tau knockout mice, initiated tau aggregation. Thus, we conclude that bacterial pneumonia initiates the release of lung endothelial-derived cytotoxic tau, which is capable of propagating a neuronal tauopathy.

"Novel Management of Depression Using Ketamine in the Intensive Care Unit".

BACKGROUND: Ketamine, a dissociative anesthetic, induces improvement in depressive symptoms by antagonizing glutaminergic NMDA receptors. Ketamine has been used previously in outpatient setting for treatment-resistant depression, but we showcase its utility in depression management at the Intensive Care Unit (ICU). Research Question: Can ketamine be used for depression treatment in ICU patients? Study Design and Methods: A retrospective chart review of ICU patients was done at a tertiary center from 2018 to 2021, to assess the ketamine usage. Among the patients reviewed, ketamine was used for depression in 12, and for analgesia & sedation in 2322 patients. Ketamine was administered in doses of 0.5mg/kg & 0.75mg/kg for depression. Each course consisted of 3 doses of ketamine administered over 3 days, and 7 in 12 patients received a single course of ketamine. The rest received 3-4 courses 1 week apart. Results: Ketamine was found to improve mood and affect in most of the patients with depression. 11 in 12 patients had a positive response with better sleep. It has a major advantage over conventional anti-depressants since it takes only a few hours to induce clinical improvement. Patients who were observably withdrawn from care team and family, were administered ketamine. Conclusion: A major drawback of ketamine is that the duration of clinical improvement is short, with the response lasting only up to seven days after a single dose. Hence, all the patients in our study were weaned off ketamine with a supporting antidepressant. Ketamine has been documented to cause cardio-neurotoxicity; however, only one patient had worsening lethargy in our study. To conclude, ketamine has a marked benefit in treating depression in the ICU. Although our study was associated with positive outcomes, there is a need for prospective studies with long-term follow-up assessments.

Antibiotic stewardship: Early discontinuation of antibiotics based on procalcitonin level in COVID-19 pneumonia.

WHAT IS KNOWN AND OBJECTIVE: Procalcitonin (PCT) levels rise in systemic inflammation, especially if bacterial in origin. COVID-19, caused by the novel coronavirus SARS-CoV-2, presents with acute respiratory distress syndrome. Elevated procalcitonin in COVID-19 is considered as a marker for severity of disease. There is no study available that indicates whether elevated PCT in COVID-19 is associated with inflammation or superimposed bacterial infection. The objective of this study is to evaluate the association between PCT levels and superadded bacterial infection, and the effect of discontinuation of antibiotic in the low PCT (<0.25 ng/ml) group on patients' outcomes. METHODS: A retrospective chart review of patients admitted with COVID-19 pneumonia at a single tertiary care centre. We collected information on demographics, co-morbidities, PCT level, antibiotic use, culture results for bacterial infection, hospital length of stay (LOS) and mortality. STATISTICAL ANALYSIS: Continuous variables were summarized with the sample median, interquartile range, mean and range. Categorical variables were summarized with number and percentage of patients. RESULTS AND DISCUSSION: We studied a total of 147 patients with COVID-19 pneumonia. 101 (69%) patients had a low PCT level (< 0.25 ng/ml). Bacterial culture results were negative for all patients, except 1 who had a markedly elevated PCT level (141.ng/ml). In patients with low PCT, 42% received no antibiotics, 59% received antibiotics initially, 32 (57%) patients antibiotic discontinued early (within 24 hours) and their culture remained negative for bacterial infections during hospitalizations. LOS was shorter (6 days in low PCT group compared to 9 days) in high PCT group. LOS was 1 day shorter (5 days vs 6 days) in no antibiotic group compared to antibiotic group. Our study examines the association between PCT level and superadded bacterial infection in COVID-19 pneumonia. Our results demonstrate that most patients admitted with COVID-19 have a low PCT (<0.25 ng/ml), which suggests no superadded bacterial infection and supports the previously published literature regarding low PCT in viral pneumonia. WHAT IS NEW AND CONCLUSION: Procalcitonin level remains low in the absence of bacterial infection. Early de-escalation/discontinuation of antibiotics is safe without adverse outcomes in COVID-19 pneumonia. Early de-escalation/discontinuation of antibiotics is associated with lower LOS.

Evaluation of Ti/Al alloy coated with biogenic hydroxyapatite as an implant device in dogs' femur bones.

The main target of the present research was a full assessment of the toxicity effects and biocompatibility of a Ti/Al-alloy device coated with biogenic hydroxyapatite (bHA) when implanted in dogs in comparison with those of an uncoated Ti/Al-alloy device. The coating of the alloy was carried out using controlled high-velocity suspension flame spray (HVSFS) technique. Both coated and uncoated devices were implanted in dogs' femur bones for different time periods (45 days and 90 days). Bone-formation ability and healing were followed up, and blood analysis was performed, at Time zero (immediately post surgery), and then at 3 days, 45 days, and 90 days post surgery. Bone mineral density checks, radiological scans of the femur bone, and histological analysis were also conducted. The in-vivo study results proved that implantation of a device made from bHA-coated Ti/Al alloy in dogs' femur bones is completely safe. This is due to the high osteoconductivity of the coated alloy, which enables the formation of new bone and a full connection between new and original bone material. At 90 days post surgery, the coated alloy had been completely digested within the original bone; thus, it appeared as a part of the femur bone and not as a foreign body. Both the scanning electron microscopy with energy-dispersive X-ray and histology analysis findings affirmed the results. Furthermore, the blood tests indicated no toxicity effects during the 90 days of implantation.

Development of an endothelial cell-restricted transgenic reporter rat: a resource for physiological studies of vascular biology.

Here, we report the generation of a Cre-recombinase (iCre) transgenic rat, where iCre is driven using a vascular endothelial-cadherin (CDH5) promoter. The CDH5 promoter was cloned from rat pulmonary microvascular endothelial cells and demonstrated ~60% similarity to the murine counterpart. The cloned rat promoter was 2,508 bp, it extended 79 bp beyond the transcription start site, and it was 22,923 bp upstream of the translation start site. The novel promoter was cloned upstream of codon-optimized iCre and subcloned into a Sleeping Beauty transposon vector for transpositional transgenesis in Sprague-Dawley rats. Transgenic founders were generated and selected for iCre expression. Crossing the CDH5-iCre rat with a tdTomato reporter rat resulted in progeny displaying endothelium-restricted fluorescence. tdTomato fluorescence was prominent in major arteries and veins, and it was similar in males and females. Quantitative analysis of the carotid artery and the jugular vein revealed that, on average, more than 50% of the vascular surface area exhibited strong fluorescence. tdTomato fluorescence was observed in the circulations of every tissue tested. The microcirculation in all tissues tested displayed homogenous fluorescence. Fluorescence was examined across young (6-7.5 mo), middle (14-16.5 mo), and old age (17-19.5 mo) groups. Although tdTomato fluorescence was seen in middle- and old-age animals, the intensity of the fluorescence was significantly reduced compared with that seen in the young rats. Thus, this endothelium-restricted transgenic rat offers a novel platform to test endothelial microheterogeneity within all vascular segments, and it provides exceptional resolution of endothelium within-organ microcirculation for application to translational disease models.NEW & NOTEWORTHY The use of transgenic mice has been instrumental in advancing molecular insight of physiological processes, yet these models oftentimes do not faithfully recapitulate human physiology and pathophysiology. Rat models better replicate some human conditions, like Group 1 pulmonary arterial hypertension. Here, we report the development of an endothelial cell-restricted transgenic reporter rat that has broad application to vascular biology. This first-in-kind model offers exceptional endothelium-restricted tdTomato expression, in both conduit vessels and the microcirculations of organs.

Spectral imaging of FRET-based sensors reveals sustained cAMP gradients in three spatial dimensions.

Cyclic AMP is a ubiquitous second messenger that orchestrates a variety of cellular functions over different timescales. The mechanisms underlying specificity within this signaling pathway are still not well understood. Several lines of evidence suggest the existence of spatial cAMP gradients within cells, and that compartmentalization underlies specificity within the cAMP signaling pathway. However, to date, no studies have visualized cAMP gradients in three spatial dimensions (3D: x, y, z).This is in part due to the limitations of FRET-based cAMP sensors, specifically the low signal-to-noise ratio intrinsic to all intracellular FRET probes. Here, we overcome this limitation, at least in part, by implementing spectral imaging approaches to estimate FRET efficiency when multiple fluorescent labels are used and when signals are measured from weakly expressed fluorescent proteins in the presence of background autofluorescence and stray light. Analysis of spectral image stacks in two spatial dimensions (2D) from single confocal slices indicates little or no cAMP gradients formed within pulmonary microvascular endothelial cells (PMVECs) under baseline conditions or following 10 min treatment with the adenylyl cyclase activator forskolin. However, analysis of spectral image stacks in 3D demonstrates marked cAMP gradients from the apical to basolateral face of PMVECs. Results demonstrate that spectral imaging approaches can be used to assess cAMP gradients-and in general gradients in fluorescence and FRET-within intact cells. Results also demonstrate that 2D imaging studies of localized fluorescence signals and, in particular, cAMP signals, whether using epifluorescence or confocal microscopy, may lead to erroneous conclusions about the existence and/or magnitude of gradients in either FRET or the underlying cAMP signals. Thus, with the exception of cellular structures that can be considered in one spatial dimension, such as neuronal processes, 3D measurements are required to assess mechanisms underlying compartmentalization and specificity within intracellular signaling pathways.

Hemoglobin A1c Has Suboptimal Performance to Diagnose and Monitor Diabetes Mellitus in Patients with Cirrhosis.

BACKGROUND: Glycated hemoglobin A1c (HbA1c) is routinely used to diagnose and monitor type 2 diabetes mellitus (T2DM) in cirrhotic patients. Remarkably, HbA1c may be falsely low in such patients. AIMS: We assessed the diagnostic and monitoring yield of HbA1c in cirrhotic patients with T2DM (DM-Cirr) and without T2DM (NoDM-Cirr). METHODS: We conducted a composite study allocating 21 NoDM-Cirr into a cross-sectional module and 16 DM-Cirr plus 13 controls with T2DM only (DM-NoCirr) into a prospective cohort. Oral glucose tolerance test (OGTT) was performed in NoDM-Cirr. DM-Cirr and DM-NoCirr were matched by sex, age, BMI, and T2DM treatment and studied with continuous glucose monitoring (CGM). Percent deviations from target, low/high blood glucose indexes (LBGI/HBGI) were calculated from CGM, as well as the average daily risk range (ADRR) as a marker of glucose variability. RESULTS: Overall, HbA1c and OGTT diagnostic yield agreed in 12 patients (57%, ρ = 0.45, p < 0.03). CGM captured 3463 glucose determinations in DM-Cirr and 4273 in DM-NoCirr (p = 0.42). Regression analysis showed an inferior association between HbA1c and CGM in DM-Cirr (R2 = 0.52), when compared to DM-NoCirr (R2 = 0.94), and fructosamine did not improve association for DM-Cirr (R2 = 0.31). Interestingly, cirrhosis and Child-Turcotte-Pugh class accounted for HbA1c variance (p < 0.05). Patients in DM-Cirr were less frequently within target glucose (70-180 mg/dL), but at higher risk for hyperglycemia (HBGI > 9) when compared to DM-NoCirr, and they also showed higher glucose variability (ADRR 13.9 ± 2.5 vs. 8.9 ± 1.8, respectively, p = 0.03). CONCLUSION: HbA1c inaccurately represents chronic glycemia in patients with cirrhosis, likely in relation to increased glucose variability.

Investigation the impact of ZTA addition on the properties of nano biogenic hydroxyapatite.

The target of the recent study is to achieve a significant inexpensive and eco-friendly way for getting ZTA/HA composites, based on the nano-HA derived from the eggshell biogenic source. Combining simultaneously the porous structure; which is considered as a bone formation key, with developed mechanical properties and adequate biocompatibility, is another purpose of this study. Furthermore, the impact of ZTA addition from 10-30 mass-%, fabricated by uniaxial pressing and sintering at 1200-1300 °C for 2 h, on the physical and mechanical properties, microstructure and phase composition of ZTA/HA composite bodies was investigated. The results demonstrated that the increasing of ZTA content increases the bodies' apparent porosity and decreases the bulk density due to the decomposition of HA into ß-TCP. Where the formation of ß-TCP possessed the predominant impact on the mechanical properties of the sintered ZTA/HA composites. ICP, SEM, EDX and thin film XRD results of composites containing 20 mass-% ZTA affirmed the excellent bioactivity of the bodies.

Changes in the Intestinal Microbiome and Alcoholic and Nonalcoholic Liver Diseases: Causes or Effects?

The prevalence of fatty liver diseases is increasing rapidly worldwide; after treatment of hepatitis C virus infection becomes more widespread, fatty liver diseases are likely to become the most prevalent liver disorders. Although fatty liver diseases are associated with alcohol, obesity, and the metabolic syndrome, their mechanisms of pathogenesis are not clear. The development and progression of fatty liver, alcoholic, and nonalcoholic liver disease (NAFLD) all appear to be influenced by the composition of the microbiota. The intestinal microbiota have been shown to affect precirrhotic and cirrhotic stages of liver diseases, which could lead to new strategies for their diagnosis, treatment, and study. We review differences and similarities in the cirrhotic and precirrhotic stages of NAFLD and alcoholic liver disease. Differences have been observed in these stages of alcohol-associated disease in patients who continue to drink compared with those who stop, with respect to the composition and function of the intestinal microbiota and intestinal integrity. NAFLD and the intestinal microbiota also differ between patients with and without diabetes. We also discuss the potential of microbial therapy for patients with NAFLD and ALD.

Gut microbiota drive the development of neuroinflammatory response in cirrhosis in mice.

UNLABELLED: The mechanisms behind the development of hepatic encephalopathy (HE) are unclear, although hyperammonemia and systemic inflammation through gut dysbiosis have been proposed. The aim of this work was to define the individual contribution of hyperammonemia and systemic inflammation on neuroinflammation in cirrhosis using germ-free (GF) and conventional mice. GF and conventional C57BL/6 mice were made cirrhotic using CCl4 gavage. These were compared to their noncirrhotic counterparts. Intestinal microbiota, systemic and neuroinflammation (including microglial and glial activation), serum ammonia, intestinal glutaminase activity, and cecal glutamine content were compared between groups. GF cirrhotic mice developed similar cirrhotic changes to conventional mice after 4 extra weeks (16 vs. 12 weeks) of CCl4 gavage. GF cirrhotic mice exhibited higher ammonia, compared to GF controls, but this was not associated with systemic or neuroinflammation. Ammonia was generated through increased small intestinal glutaminase activity with concomitantly reduced intestinal glutamine levels. However, conventional cirrhotic mice had intestinal dysbiosis as well as systemic inflammation, associated with increased serum ammonia, compared to conventional controls. This was associated with neuroinflammation and glial/microglial activation. Correlation network analysis in conventional mice showed significant linkages between systemic/neuroinflammation, intestinal microbiota, and ammonia. Specifically beneficial, autochthonous taxa were negatively linked with brain and systemic inflammation, ammonia, and with Staphylococcaceae, Lactobacillaceae, and Streptococcaceae. Enterobacteriaceae were positively linked with serum inflammatory cytokines. CONCLUSION: Gut microbiota changes drive development of neuroinflammatory and systemic inflammatory responses in cirrhotic animals. (Hepatology 2016;64:1232-1248).

Salivary microbiota reflects changes in gut microbiota in cirrhosis with hepatic encephalopathy.

UNLABELLED: Altered gut microbiome is associated with systemic inflammation and cirrhosis decompensation. However, the correlation of the oral microbiome with inflammation in cirrhosis is unclear. Our aim was to evaluate the oral microbiome in cirrhosis and compare with stool microbiome. Outpatients with cirrhosis (with/without hepatic encephalopathy [HE]) and controls underwent stool/saliva microbiome analysis (for composition and function) and also systemic inflammatory evaluation. Ninety-day liver-related hospitalizations were recorded. Salivary inflammation was studied using T helper 1 cytokines/secretory immunoglobulin A (IgA), histatins and lysozyme in a subsequent group. A total of 102 patients with cirrhosis (43 previous HE) and 32 age-matched controls were included. On principal component analysis (PCA), stool and saliva microbiome clustered far apart, showing differences between sites as a whole. In salivary microbiome, with previous HE, relative abundance of autochthonous families decreased whereas potentially pathogenic ones (Enterobacteriaceae, Enterococcaceae) increased in saliva. Endotoxin-related predicted functions were significantly higher in cirrhotic saliva. In stool microbiome, relative autochthonous taxa abundance reduced in previous HE, along with increased Enterobacteriaceae and Enterococcaceae. Cirrhotic stool microbiota demonstrated a significantly higher correlation with systemic inflammation, compared to saliva microbiota, on correlation networks. Thirty-eight patients were hospitalized within 90 days. Their salivary dysbiosis was significantly worse and predicted this outcome independent of cirrhosis severity. Salivary inflammation was studied in an additional 86 age-matched subjects (43 controls/43 patients with cirrhosis); significantly higher interleukin (IL)-6/IL-1ß, secretory IgA, and lower lysozyme, and histatins 1 and 5 were found in patients with cirrhosis, compared to controls. CONCLUSIONS: Dysbiosis, represented by reduction in autochthonous bacteria, is present in both saliva and stool in patients with cirrhosis, compared to controls. Patients with cirrhosis have impaired salivary defenses and worse inflammation. Salivary dysbiosis was greater in patients with cirrhosis who developed 90-day hospitalizations. These findings could represent a global mucosal-immune interface change in cirrhosis.

Systems biology analysis of omeprazole therapy in cirrhosis demonstrates significant shifts in gut microbiota composition and function.

Proton pump inhibitors (PPI) have been associated with infectious complications in cirrhosis, but their impact on distal gut microbiota composition and function is unclear. We aimed to evaluate changes in stool microbiota composition and function in patients with cirrhosis and healthy controls after omeprazole therapy. Both 15 compensated cirrhotic patients and 15 age-matched controls underwent serum gastrin measurement, stool microbiota profiling with multitagged pyrosequencing, and urinary metabolic profiling with NMR spectroscopy to assess microbial cometabolites before/after a 14-day course of 40 mg/day omeprazole under constant diet conditions. Results before (pre) and after PPI were compared in both groups, compared with baseline by systems biology techniques. Adherence was >95% without changes in diet or MELD (model for end-stage liver disease) score during the study. Serum gastrin concentrations significantly increased after PPI in cirrhosis (pre 38.3 ± 35.8 vs. 115.6 ± 79.3 pg/ml P < 0.0001) and controls (pre 29.9 ± 14.5 vs. 116.0 ± 74.0 pg/ml, P = 0.001). A significant microbiota change was seen in both controls and cirrhosis after omeprazole (QIIME P < 0.0001). Relative Streptococcaceae abundance, normally abundant in saliva, significantly increased postomeprazole in controls (1 vs. 5%) and cirrhosis (0 vs. 9%) and was correlated with serum gastrin levels (r = 0.4, P = 0.005). We found significantly reduced hippurate in cirrhosis vs. controls both pre- and postomeprazole and increased lactate in both groups post vs. preomeprazole, whereas dimethylamine (DMA) decreased in cirrhosis only. On correlation network analysis, significant changes in linkages of bacteria with metabolites (hippurate/DMA/lactate) were found postomeprazole, compared with pre-PPI in cirrhosis patients. In conclusion, omeprazole is associated with a microbiota shift and functional change in the distal gut in patients with compensated cirrhosis that could set the stage for bacterial overgrowth.

Rare Variant of Hereditary Amyloid Transthyretin Cardiomyopathy Secondary to Ser97Tyr Mutation.

Hereditary transthyretin amyloidosis (hATTR) is an autosomal dominant, adult-onset disease that stems from point mutations in the TTR gene encoding the protein transthyretin. The disease is progressive and life-threatening and is associated with amyloid deposits in multiple organs including the heart, kidney, skin, eyes, nervous system, and gastrointestinal tract. Genotypic and phenotypic heterogeneity is a characteristic hallmark of hereditary transthyretin amyloidosis. Herein, we present a rare variant of hATTR cardiomyopathy secondary to Ser97Tyr mutation, having been documented only in a handful of families previously. This case serves as a valuable opportunity to elucidate the clinico-pathogenesis of this disease, highlight the aggressive nature of this genetic mutation (c.290C>A; p.Ser97Tyr), and document the response to the latest advances in treatment currently available.

Comprehensive review of statin-intolerance and the practical application of Bempedoic Acid.

Statin-intolerance (SI) has prevalence between 8.0 % and 10 %, and muscular complaints are the most common reason for discontinuation. Bempedoic acid (BA), an ATP citrate lyase inhibitor, decreases hepatic generation of cholesterol, upregulates low-density lipoprotein (LDL) receptor expression in the liver, and eventually clears circulating LDL-cholesterol from the blood. Multiple randomized clinical trials studying BA demonstrate a reduction in LDL levels by 17-28 % in SI. The CLEAR OUTCOME trial established significant cardiovascular benefits with BA. A dose of 180 mg/day of BA showed promising results. BA alone or in combination with ezetimibe is US Food and Drug Administration-approved for use in adults with heterozygous familial hypercholesterolemia and/or established atherosclerotic cardiovascular disease. BA reduced HbA1c by 0.12 % (p < 0.0001) in patients with diabetes. Adverse events of BA include myalgia (4.7 %), anemia (3.4 %), and increased aminotransferases (0.3 %). BA can cause up to four times higher risk of gout in those with a previous gout diagnosis or high serum uric acid levels. Reports of increased blood urea nitrogen and serum creatinine were noted. Current evidence does not demonstrate a reduction in deaths from cardiovascular causes. More studies that include a diverse population and patients with both high and low LDL levels should be conducted. We recommend that providers consider BA as an adjunct to statin therapy in patients with a maximally tolerated dosage to specifically target LDL levels.

Inflammatory Bowel Disease and Cardiovascular Disease: An Integrative Review With a Focus on the Gut Microbiome.

Inflammatory bowel disease (IBD), which includes Crohn's disease and ulcerative colitis, is a chronic inflammatory condition of the gastrointestinal tract. Recent research indicates a significant link between IBD and cardiovascular disease (CVD), the leading cause of global morbidity and mortality. This review examines the association between IBD and CVD, emphasizing the role of the gut microbiome in this relationship. IBD patients have a higher risk of cardiovascular events, such as coronary artery disease, heart failure, and cerebrovascular incidents, primarily due to chronic systemic inflammation, genetic factors, and gut microbiota imbalance (dysbiosis). Dysbiosis in IBD increases intestinal permeability, allowing bacterial products to enter the bloodstream, which promotes inflammation and endothelial dysfunction, contributing to CVD. Understanding the gut microbiome's role in IBD and CVD suggests new therapeutic interventions. Modulating the microbiome through diet, probiotics, and fecal microbiota transplantation (FMT) are promising research avenues. These interventions aim to restore a healthy gut microbiota balance, potentially reducing inflammation and improving cardiovascular outcomes. Additionally, the review emphasizes the importance of regular cardiovascular risk assessments and personalized preventive measures in managing IBD patients. Such measures include routine monitoring of cardiovascular health, tailored lifestyle modifications, and early intervention strategies to mitigate cardiovascular risk. By integrating current knowledge, this review aims to improve understanding and management of the interconnected pathophysiology of IBD and CVD. This approach will ultimately enhance patient outcomes and provide a foundation for future research and clinical practice guidelines in this area.

An approach for characterizing and comparing hyperspectral microscopy systems.

Hyperspectral imaging and analysis approaches offer accurate detection and quantification of fluorescently-labeled proteins and cells in highly autofluorescent tissues. However, selecting optimum acquisition settings for hyperspectral imaging is often a daunting task. In this study, we compared two hyperspectral systems-a widefield system with acoustic optical tunable filter (AOTF) and charge coupled device (CCD) camera, and a confocal system with diffraction gratings and photomultiplier tube (PMT) array. We measured the effects of system parameters on hyperspectral image quality and linear unmixing results. Parameters that were assessed for the confocal system included pinhole diameter, laser power, PMT gain and for the widefield system included arc lamp intensity, and camera gain. The signal-to-noise ratio (SNR) and the root-mean-square error (RMS error) were measured to assess system performance. Photobleaching dynamics were studied. Finally, theoretical sensitivity studies were performed to estimate the incremental response (sensitivity) and false-positive detection rates (specificity). Results indicate that hyperspectral imaging assays are highly dependent on system parameters and experimental conditions. For detection of green fluorescent protein (GFP)-expressing cells in fixed lung tissues, a confocal pinhole of five airy disk units, high excitation intensity and low detector gain were optimal. The theoretical sensitivity studies revealed that widefield hyperspectral microscopy was able to detect GFP with fewer false positive occurrences than confocal microscopy, even though confocal microscopy offered improved signal and noise characteristics. These studies provide a framework for optimization that can be applied to a variety of hyperspectral imaging systems.

In-vitro and in-vivo evaluation for the bio-natural Alginate/nano-Hydroxyapatite (Alg/n-HA) injectable hydrogel for critical size bone substitution.

Currently, bio-natural injectable hydrogels are receiving a lot of attention due to their ability to control, adjust, and adapt to random bone defects, in addition, to their ability to mimic the composition of natural bones. From such a viewpoint, this study goal is to prepare and characterize the injectable hydrogels paste based on the natural alginate (Alg) derived from brown sea algae as a polysaccharide polymer, which coupled with nano biogenic-hydroxyapatite (n-HA) prepared from eggshells and enriched with valuable trace elements. The viscosity and mechanical properties of the paste were investigated. As well as the in-vitro study in terms of water absorption and biodegradability in the PBS, biocompatibility and the capability of the injectable Alginate/n-Hydroxyapatite (Alg/n-HA) to regenerate bone for the most suitable injectable form. The injectable hydrogel (BP -B sample) was chosen for the study as it had an appropriate setting time for injecting (13 mins), and suitable compressive strength reached 6.3 MPa. The in vivo study was also carried out including a post-surgery follow-up test of the newly formed bone (NB) in the defect area after 10 and 20 weeks using different techniques such as (SEM/EDX) and histological analysis, the density of the newly formed bone by Dual x-ray absorptiometry (DEXA), blood biochemistry and the radiology test. The results proved that the injectable hydrogels Alginate/n-Hydroxyapatite (Alg/n-HA) had an appreciated biodegradability and bioactivity, which allow the progress of angiogenesis, endochondral ossification, and osteogenesis throughout the defect area, which positively impacts the healing time and ensures the full restoration for the well-mature bone tissue that similar to the natural bone.

Intraoperative Ultrasound for Extracting Deep-Seated Radio-Opaque Foreign Body from Calf: A Case Report.

CASE: A 50-year-old man presented with chronic refractory symptoms of radiating leg pain with muscle cramps because of a retained bullet in the calf after being shot in 1990. Radiographs confirmed the bullet lodged in posterolateral aspect of calf abutting proximal fibula. An intraoperative point-of-care ultrasound aided in accurate localization of bullet, thereby facilitating precise planning of surgical incision and subsequent removal. CONCLUSIONS: Ultrasound can be used as an alternative tool for safe surgical extraction of deep-seated metallic object with minimal tissue dissection, obviating the need for C-arm.