Platelet Metabolic Profiling Reveals Glycolytic and 1-Carbon Metabolites Are Essential for GP VI-Stimulated Human Platelets-Brief Report.

BACKGROUND: Evolving evidence suggests that besides signaling pathways, platelet activation involves a complex interplay between metabolic pathways to support thrombus growth. Selective targeting of metabolic checkpoints may inhibit platelet activation and provide a novel antiplatelet strategy. We, therefore, examined global metabolic changes that occur during the transition of human platelets from resting to an activated state to identify metabolites and associated pathways that contribute to platelet activation. METHODS: We performed metabolic profiling of resting and convulxin-stimulated human platelet samples. The differential levels, pathway analysis, and PCA (principal component analysis) were performed using Metaboanalyst. Metascape was used for metabolite network construction. RESULTS: Of the 401 metabolites identified, 202 metabolites were significantly upregulated, and 2 metabolites were downregulated in activated platelets. Of all the metabolites, lipids scored highly and constituted ≈50% of the identification. During activation, aerobic glycolysis supports energy demand and provides glycolytic intermediates required by metabolic pathways. Consistent with this, an important category of metabolites was carbohydrates, particularly the glycolysis intermediates that were significantly upregulated compared with resting platelets. We found that lysophospholipids such as 1-palmitoyl-GPA (glycero-3-phosphatidic acid), 1-stearoyl-GPS (glycero-3-phosphoserine), 1-palmitoyl-GPI (glycerophosphoinositol), 1-stearoyl-GPI, and 1-oleoyl-GPI were upregulated in activated platelets. We speculated that platelet activation could be linked to 1-carbon metabolism, a set of biochemical pathways that involve the transfer and use of 1-carbon units from amino acids, for cellular processes, including nucleotide and lysophospholipid synthesis. In alignment, based on pathway enrichment and network-based prioritization, the metabolites from amino acid metabolism, including serine, glutamate, and branched-chain amino acid pathway were upregulated in activated platelets, which might be supplemented by the high levels of glycolytic intermediates. CONCLUSIONS: Metabolic analysis of resting and activated platelets revealed that glycolysis and 1-carbon metabolism are necessary to support platelet activation.

PKM2 promotes neutrophil activation and cerebral thromboinflammation: therapeutic implications for ischemic stroke.

There is a critical need for cerebro-protective interventions to improve the suboptimal outcomes of patients with ischemic stroke who have been treated with reperfusion strategies. We found that nuclear pyruvate kinase muscle 2 (PKM2), a modulator of systemic inflammation, was upregulated in neutrophils after the onset of ischemic stroke in both humans and mice. Therefore, we determined the role of PKM2 in stroke pathogenesis by using murine models with preexisting comorbidities. We generated novel myeloid cell-specific PKM2-/- mice on wild-type (PKM2fl/flLysMCre+) and hyperlipidemic background (PKM2fl/flLysMCre+Apoe-/-). Controls were littermate PKM2fl/flLysMCre- or PKM2fl/flLysMCre-Apoe-/- mice. Genetic deletion of PKM2 in myeloid cells limited inflammatory response in peripheral neutrophils and reduced neutrophil extracellular traps after cerebral ischemia and reperfusion, suggesting that PKM2 promotes neutrophil hyperactivation in the setting of stroke. In the filament and autologous clot and recombinant tissue plasminogen activator stroke models, irrespective of sex, deletion of PKM2 in myeloid cells in either wild-type or hyperlipidemic mice reduced infarcts and enhanced long-term sensorimotor recovery. Laser speckle imaging revealed improved regional cerebral blood flow in myeloid cell-specific PKM2-deficient mice that was concomitant with reduced post-ischemic cerebral thrombo-inflammation (intracerebral fibrinogen, platelet [CD41+] deposition, neutrophil infiltration, and inflammatory cytokines). Mechanistically, PKM2 regulates post-ischemic inflammation in peripheral neutrophils by promoting STAT3 phosphorylation. To enhance the translational significance, we inhibited PKM2 nuclear translocation using a small molecule and found significantly reduced neutrophil hyperactivation and improved short-term and long-term functional outcomes after stroke. Collectively, these findings identify PKM2 as a novel therapeutic target to improve brain salvage and recovery after reperfusion.

Myeloid Cell PKM2 Deletion Enhances Efferocytosis and Reduces Atherosclerosis.

BACKGROUND: The glycolytic enzyme PKM2 (pyruvate kinase muscle 2) is upregulated in monocytes/macrophages of patients with atherosclerotic coronary artery disease. However, the role of cell type-specific PKM2 in the setting of atherosclerosis remains to be defined. We determined whether myeloid cell-specific PKM2 regulates efferocytosis and atherosclerosis. METHODS: We generated myeloid cell-specific PKM2-/- mice on Ldlr (low-density lipoprotein receptor)-deficient background (PKM2mye-KOLdlr-/-). Controls were littermate PKM2WTLdlr-/- mice. Susceptibility to atherosclerosis was evaluated in whole aortae and cross sections of the aortic sinus in male and female mice fed a high-fat Western diet for 14 weeks, starting at 8 weeks. RESULTS: PKM2 was upregulated in macrophages of Ldlr-/- mice fed a high-fat Western diet compared with chow diet. Myeloid cell-specific deletion of PKM2 led to a significant reduction in lesions in the whole aorta and aortic sinus despite high cholesterol and triglyceride levels. Furthermore, we found decreased macrophage content in the lesions of myeloid cell-specific PKM2-/- mice associated with decreased MCP-1 (monocyte chemoattractant protein 1) levels in plasma, reduced transmigration of macrophages in response to MCP-1, and impaired glycolytic rate. Macrophages isolated from myeloid-specific PKM2-/- mice fed the Western diet exhibited reduced expression of proinflammatory genes, including MCP-1, IL (interleukin)-1ß, and IL-12. Myeloid cell-specific PKM2-/- mice exhibited reduced apoptosis concomitant with enhanced macrophage efferocytosis and upregulation of LRP (LDLR-related protein)-1 in macrophages in vitro and atherosclerotic lesions in vivo. Silencing LRP-1 in PKM2-deficient macrophages restored inflammatory gene expression and reduced efferocytosis. As a therapeutic intervention, inhibiting PKM2 nuclear translocation using a small molecule reduced glycolytic rate, enhanced efferocytosis, and reduced atherosclerosis in Ldlr-/- mice. CONCLUSIONS: Genetic deletion of PKM2 in myeloid cells or limiting its nuclear translocation reduces atherosclerosis by suppressing inflammation and enhancing efferocytosis.

Targeting Neutrophil α9 Improves Functional Outcomes After Stroke in Mice With Obesity-Induced Hyperglycemia.

BACKGROUND: Obesity-induced hyperglycemia is a significant risk factor for stroke. Integrin α9ß1 is expressed on neutrophils and stabilizes adhesion to the endothelium via ligands, including Fn-EDA (fibronectin containing extra domain A) and tenascin C. Although myeloid deletion of α9 reduces susceptibility to ischemic stroke, it is unclear whether this is mediated by neutrophil-derived α9. We determined the role of neutrophil-specific α9 in stroke outcomes in a mice model with obesity-induced hyperglycemia. METHODS: α9Neu-KO (α9fl/flMRP8Cre+) and littermate control α9WT (α9fl/flMRP8Cre-) mice were fed on a 60% high-fat diet for 20 weeks to induce obesity-induced hyperglycemia. Functional outcomes were evaluated up to 28 days after stroke onset in mice of both sexes using a transient (30 minutes) middle cerebral artery ischemia. Infarct volume (magnetic resonance imaging) and postreperfusion thrombo-inflammation (thrombi, fibrin, neutrophil, phospho-nuclear factor kappa B [p-NFκB], TNF [tumor necrosis factor]-α, and IL [interleukin]-1ß levels, markers of neutrophil extracellular traps) were measured post 6 or 48 hours of reperfusion. In addition, functional outcomes (modified Neurological Severity Score, rota-rod, corner, and wire-hanging test) were measured for up to 4 weeks. RESULTS: Stroke upregulated neutrophil α9 expression more in obese mice (P<0.05 versus lean mice). Irrespective of sex, deletion of neutrophil α9 improved functional outcomes up to 4 weeks, concomitant with reduced infarct, improved cerebral blood flow, decreased postreperfusion thrombo-inflammation, and neutrophil extracellular traps formation (NETosis) (P<0.05 versus α9WT obese mice). Obese α9Neu-KO mice were less susceptible to thrombosis in FeCl3 injury-induced carotid thrombosis model. Mechanistically, we found that α9/cellular fibronectin axis contributes to NETosis via ERK (extracellular signal-regulated kinase) and PAD4 (peptidyl arginine deiminase 4), and neutrophil α9 worsens stroke outcomes via cellular fibronectin-EDA but not tenascin C. Obese wild-type mice infused with anti-integrin α9 exhibited improved functional outcomes up to 4 weeks (P<0.05 versus vehicle). CONCLUSIONS: Genetic ablation of neutrophil-specific α9 or pharmacological inhibition improves long-term functional outcomes after stroke in mice with obesity-induced hyperglycemia, most likely by limiting thrombo-inflammation.

The metabolic enzyme pyruvate kinase M2 regulates platelet function and arterial thrombosis.

Very little is known about the role of metabolic regulatory mechanisms in platelet activation and thrombosis. Dimeric pyruvate kinase M2 (PKM2) is a crucial regulator of aerobic glycolysis that facilitates the production of lactate and metabolic reprogramming. Herein, we report that limiting PKM2 dimer formation, using the small molecule inhibitor ML265, negatively regulates lactate production and glucose uptake in human and murine stimulated platelets. Furthermore, limiting PKM2 dimer formation reduced agonist-induced platelet activation, aggregation, clot retraction, and thrombus formation under arterial shear stress in vitro in both human and murine platelets. Mechanistically, limiting PKM2 dimerization downregulated phosphatidylinositol 3-kinase (PI3K)-mediated protein kinase B or serine/threonine-specific protein kinase (Akt)/glycogen synthase kinase 3 (GSK3) signaling in human and murine platelets. To provide further evidence for the role of PKM2 in platelet function, we generated a megakaryocyte or platelet-specific PKM2-/- mutant strain (PKM2fl/flPF4Cre+). Platelet-specific PKM2-deficient mice exhibited impaired agonist-induced platelet activation, aggregation, clot retraction, and PI3K-mediated Akt/GSK3 signaling and were less susceptible to arterial thrombosis in FeCl3 injury-induced carotid- and laser injury-induced mesenteric artery thrombosis models, without altering hemostasis. Wild-type mice treated with ML265 were less susceptible to arterial thrombosis with unaltered tail bleeding times. These findings reveal a major role for PKM2 in coordinating multiple aspects of platelet function, from metabolism to cellular signaling to thrombosis, and implicate PKM2 as a potential target for antithrombotic therapeutic intervention.

US Quantification of Liver Fat: Past, Present, and Future.

Fatty liver disease has a high and increasing prevalence worldwide, is associated with adverse cardiovascular events and higher long-term medical costs, and may lead to liver-related morbidity and mortality. There is an urgent need for accurate, reproducible, accessible, and noninvasive techniques appropriate for detecting and quantifying liver fat in the general population and for monitoring treatment response in at-risk patients. CT may play a potential role in opportunistic screening, and MRI proton-density fat fraction provides high accuracy for liver fat quantification; however, these imaging modalities may not be suited for widespread screening and surveillance, given the high global prevalence. US, a safe and widely available modality, is well positioned as a screening and surveillance tool. Although well-established qualitative signs of liver fat perform well in moderate and severe steatosis, these signs are less reliable for grading mild steatosis and are likely unreliable for detecting subtle changes over time. New and emerging quantitative biomarkers of liver fat, such as those based on standardized measurements of attenuation, backscatter, and speed of sound, hold promise. Evolving techniques such as multiparametric modeling, radiofrequency envelope analysis, and artificial intelligence-based tools are also on the horizon. The authors discuss the societal impact of fatty liver disease, summarize the current state of liver fat quantification with CT and MRI, and describe past, currently available, and potential future US-based techniques for evaluating liver fat. For each US-based technique, they describe the concept, measurement method, advantages, and limitations. © RSNA, 2023 Online supplemental material is available for this article. Quiz questions for this article are available through the Online Learning Center.

The Stroke Preclinical Assessment Network: Rationale, Design, Feasibility, and Stage 1 Results.

Cerebral ischemia and reperfusion initiate cellular events in brain that lead to neurological disability. Investigating these cellular events provides ample targets for developing new treatments. Despite considerable work, no such therapy has translated into successful stroke treatment. Among other issues-such as incomplete mechanistic knowledge and faulty clinical trial design-a key contributor to prior translational failures may be insufficient scientific rigor during preclinical assessment: nonblinded outcome assessment; missing randomization; inappropriate sample sizes; and preclinical assessments in young male animals that ignore relevant biological variables, such as age, sex, and relevant comorbid diseases. Promising results are rarely replicated in multiple laboratories. We sought to address some of these issues with rigorous assessment of candidate treatments across 6 independent research laboratories. The Stroke Preclinical Assessment Network (SPAN) implements state-of-the-art experimental design to test the hypothesis that rigorous preclinical assessment can successfully reduce or eliminate common sources of bias in choosing treatments for evaluation in clinical studies. SPAN is a randomized, placebo-controlled, blinded, multilaboratory trial using a multi-arm multi-stage protocol to select one or more putative stroke treatments with an implied high likelihood of success in human clinical stroke trials. The first stage of SPAN implemented procedural standardization and experimental rigor. All participating research laboratories performed middle cerebral artery occlusion surgery adhering to a common protocol and rapidly enrolled 913 mice in the first of 4 planned stages with excellent protocol adherence, remarkable data completion and low rates of subject loss. SPAN stage 1 successfully implemented treatment masking, randomization, prerandomization inclusion/exclusion criteria, and blinded assessment to exclude bias. Our data suggest that a large, multilaboratory, preclinical assessment effort to reduce known sources of bias is feasible and practical. Subsequent SPAN stages will evaluate candidate treatments for potential success in future stroke clinical trials using aged animals and animals with comorbid conditions.

Targeting myeloid-cell specific integrin α9ß1 inhibits arterial thrombosis in mice.

Evidence suggests that neutrophils contribute to thrombosis via several mechanisms, including neutrophil extracellular traps (NETs) formation. Integrin α9ß1 is highly expressed on neutrophils when compared with monocytes. It undergoes affinity upregulation on neutrophil activation, and stabilizes adhesion to the activated endothelium. The role of integrin α9 in arterial thrombosis remains unexplored. We generated novel myeloid cell-specific integrin α9-/- mice (α9fl/flLysMCre+) to study the role of integrin α9 in arterial thrombosis. α9fl/fl littermates were used as controls. We report that α9fl/flLysMCre+ mice were less susceptible to arterial thrombosis in ferric chloride (FeCl3) and laser injury-induced thrombosis models with unaltered hemostasis. Neutrophil elastase-positive cells were significantly reduced in α9fl/flLysMCre+ mice concomitant with reduction in neutrophil count, myeloperoxidase levels, and red blood cells in the FeCl3 injury-induced carotid thrombus. The percentage of cells releasing NETs was significantly reduced in α9fl/flLysMCre+ mouse neutrophils stimulated with thrombin-activated platelets. Furthermore, we found a significant decrease in neutrophil-mediated platelet aggregation and cathepsin-G secretion in α9fl/flLysMCre+ mice. Transfusion of α9fl/fl neutrophils in α9fl/flLysMCre+ mice restored thrombosis similar to α9fl/fl mice. Treatment of wild-type mice with anti-integrin α9 antibody inhibited arterial thrombosis. This study identifies the potential role of integrin α9 in modulating arterial thrombosis.

Decreased outflow facility and Schlemm's canal defects in a mouse model of glaucoma.

Previously we identified B6.EDA+/+ mice as a novel mouse model that presents with elevated IOP and trabecular meshwork damage. Here, we expand on our previous findings by measuring aqueous humor outflow facility and analyzing the integrity of the inner wall of Schlemm's canal. As expected, intraocular pressure (IOP) was increased, and outflow facility was decreased compared to C57BL/6J controls. B6.EDA+/+ mice had significantly increased expression of the adherens junction protein, VE-cadherin by the inner wall endothelium of Schlemm's canal. These data suggest that in addition to trabecular meshwork damage, there are changes in Schlemm's canal in B6.EDA+/+ mice that lead to aqueous outflow dysfunction and ocular hypertension.

Predicting need for intervention in acute necrotizing pancreatitis following discharge- A single center experience in 525 patients.

BACKGROUND AND AIMS: The clinical course of necrotizing pancreatitis (NP) is variable and unpredictable, with some patients managed conservatively, but a significant proportion become symptomatic and needing intervention for drainage and/or necrosectomy. The aim of this study was to identify patients based on baseline clinical and imaging metrics who will likely need intervention and therefore closer follow-up. METHODS: All NP patients managed in our institution between 2010 and 2019 were identified from a prospective database and those who did not undergo intervention during initial hospitalization were followed longitudinally post discharge until clinical and imaging resolution of necrosis. Patients were categorized into a conservative arm or intervention arm (endoscopic/percutaneous/surgical drainage and/or necrosectomy) for criteria defined according to IAP/APA guidelines. Clinical and imaging characteristics during initial presentation were analyzed between the two groups to identify independent predictors for eventual intervention using multivariable logistic regression. A nomogram was designed based on factors that were significant as defined by P value < 0.05. RESULTS: Among 525 patients, 340 who did not meet criteria for intervention during initial admission were included for study and followed for an average 7.4 ± 11.3 months. 140 were managed conservatively and 200 needed intervention (168 within 6 months and 32 after 6 months). Independent predictors of need for eventual intervention were white race [OR 3.43 (1.11-10.62)], transferred status [OR 3.37 (1.81-6.27)], and need for TPN [OR 6.86 (1.63-28.9)], necrotic collection greater than 6 cm [OR 8.66 (4.10-18.32)] and necrotic collection with greater than 75% encapsulation [OR 41.3 (8.29-205.5)]. A prediction model incorporating these factors demonstrated an area under the curve of 0.88. CONCLUSIONS: Majority of NP patients do not need intervention during initial admission but may require drainage/necrosectomy mostly in the first 6 months following discharge. Need for subsequent intervention can be accurately predicted by a combination of clinical and imaging features on index admission.

Targeting Myeloid-Specific Integrin α9ß1 Improves Short- and Long-Term Stroke Outcomes in Murine Models With Preexisting Comorbidities by Limiting Thrombosis and Inflammation.

RATIONALE: Currently, there is no effective intervention available that can reduce brain damage following reperfusion. Clinical studies suggest a positive correlation between the increased influx of neutrophils and severity of brain injury following reperfusion. Integrin α9ß1 is highly expressed on activated neutrophils and contributes to stable adhesion, but its role in stroke outcome has not been demonstrated to date. OBJECTIVE: We sought to determine the mechanistic role of myeloid-specific α9ß1 in the progression of ischemic stroke in murine models with preexisting comorbidities. METHODS AND RESULTS: We generated novel myeloid-specific α9-deficient (α9-/-) wild type (α9fl/flLysMCre+/-), hyperlipidemic (α9fl/flLysMCre+/-Apoe-/-), and aged (bone marrow chimeric) mice to evaluate stroke outcome. Susceptibility to ischemia/reperfusion injury was evaluated at 1, 7, and 28 days following reperfusion in 2 models of experimental stroke: filament and embolic. We found that peripheral neutrophils displayed elevated α9 expression following stroke. Irrespective of sex, genetic deletion of α9 in myeloid cells improved short- and long-term stroke outcomes in the wild type, hyperlipidemic, and aged mice. Improved stroke outcome and enhanced survival in myeloid-specific α9-/- mice was because of marked decrease in cerebral thromboinflammatory response as evidenced by reduced fibrin, platelet thrombi, neutrophil, NETosis, and decreased phospho-NF-κB (nuclear factor-κB), TNF (tumor necrosis factor)-α, and IL (interleukin)-1ß levels. α9-/- mice were less susceptible to FeCl3 injury-induced carotid artery thrombosis that was concomitant with improved regional cerebral blood flow following stroke as revealed by laser speckle imaging. Mechanistically, fibronectin containing extra domain A, a ligand for integrin α9, partially contributed to α9-mediated stroke exacerbation. Infusion of a specific anti-integrin α9 inhibitor into hyperlipidemic mice following reperfusion significantly reduced infarct volume and improved short- and long-term functional outcomes up to 28 days. CONCLUSIONS: We provide genetic and pharmacological evidence for the first time that targeting myeloid-specific integrin α9ß1 improves short- and long-term functional outcomes in stroke models with preexisting comorbidities by limiting cerebral thrombosis and inflammation.

Smooth Muscle Cell-Specific PKM2 (Pyruvate Kinase Muscle 2) Promotes Smooth Muscle Cell Phenotypic Switching and Neointimal Hyperplasia.

[Figure: see text].

Global epidemiological burden of fungal infections in cirrhosis patients: A systematic review with meta-analysis.

BACKGROUND AND AIMS: Fungal infections (FIs) have serious implications, yet understated in cirrhosis. Therefore, we reviewed the epidemiology and trends of FIs among cirrhotics. METHODS: Four electronic databases were searched for full-text articles describing prevalence of FIs in cirrhosis. Studies from post-transplant, malignancy and classical-immuno-deficiency patients were excluded. A random-effects meta-analysis was done to pool estimates of FIs (overall, and by type and infection-site), and their variation(I2 ) was explored on moderator-analysis and meta-regression. Risk of bias and asymmetry in estimates was assessed by a checklist and Egger's regression, respectively.(CRD42019142782). RESULTS: Thirty-four low-risk and four moderate-risk studies (31 984 cirrhotics) were included. Pooled estimates of overall FIs (17 studies), invasive fungal infections (IFIs; 17 studies), invasive candidiasis (23 studies) and invasive aspergillosis (16 studies) in cirrhosis were 10.2%(6.0-16.9), 9.5%(5.4-16.2), 4.0%(2.0-8.0) and 2.8%(1.5-5.3), respectively (I2  > 90%;each). Site of FIs in decreasing order of pooled prevalence was pulmonary, urinary tract, bloodstream, peritoneal, oesophageal and cerebral. Geographic differences in these estimates were remarkable, with highest burden of overall FIs from Belgium, the United States and India. Non-albicans-Candida and Aspergillus infections have increased over the last decade in cirrhosis. Intensive-care-unit (ICU)-admitted and acute-on-chronic liver failure (ACLF) patients had the highest prevalence of IFIs. MELD score(cases), bias score and sample size across studies were the predictors of variance in overall FI estimates. Diabetes, steroid and broad-spectrum antibiotic-exposure, and multiple organ failures were the common predispositions reported in patients with FIs. CONCLUSIONS: FIs impose a substantial burden in cirrhosis. ACLF and ICU admission should be considered as a host factor for defining IFIs. Epidemiology of FIs can guide interpretation of biomarkers and antifungal treatment in cirrhosis.

Effect of Probiotics on the Frequency of CD4+ T-Cells in HIV-Infected Children and Adolescents: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

BACKGROUND: Depletion of CD4+ T-cells in the gut-associated lymphoid tissue is the hallmark of HIV infection, with only partial restoration by potent antiretroviral therapy (ART). Gut dysbiosis, together with disruption of mucosal integrity contributes to chronic immune activation that further exacerbates the disease. Data from randomized controlled trials in pediatric HIV patients have indicated potential of probiotics in complementing routine ART in managing HIV-associated gastrointestinal complications. We have systematically extracted data from these trials and performed meta-analysis to quantify the effect of probiotics on CD4+ T-cell counts and any adverse events associated with their supplementation. METHODS: A systematic search through multiple databases yielded three studies that were pooled using fixed-effect model. Risk of bias assessment was done by the Cochrane risk of bias tool and publication bias was assessed by Egger's test. RESULTS: Included studies had moderate risk of bias and Egger's statistics revealed no publication bias (p > 0.05). Pooled analysis showed significant improvement in CD4+ T-cell counts, with mean difference, 123.92 (95% CI: 104.36-143.48), p < 0.0001, no heterogeneity (I2=0) among the included trials. Subgroup analysis also depicted improvement in CD4+ T-cell counts irrespective of treatment duration, in both ART naïve and treated patients. No adverse effects with probiotic consumption were reported. CONCLUSIONS: Probiotics supplementation led to an improvement in CD4+ T-cell counts among HIV-infected children with no observed adverse effects. Despite the inherent limitations of included studies, our systematic review would justify more well-designed, large-scale trials in children, which may guide pediatricians on whether to incorporate probiotics as an adjunct therapy to routine ART.

HIV infection is associated with a progressive decline of CD4+ T-cell numbers and increase in viral load. To keep the virus replication in check, patients need to take the antiretroviral therapy life-long, which is not without gastrointestinal discomfort. Probiotics have already shown multiple benefits ranging from reduction in diarrhea, nausea and bloating besides replenishment of CD4+ T-cells numbers. Based on this background information, we have compiled the data on probiotics among HIV-infected children. A pooled analysis from randomized clinical trials revealed significant improvement in CD4+ T-cell counts in HIV-infected children without any adverse effects. However, we recommend large and well-designed trials in future that would help in forming a concrete and high quality evidence in this context.

Iron nanoparticles as a promising compound for food fortification in iron deficiency anemia: a review.

Abstract: Iron deficiency anemia (IDA) is a global health concern that is affecting all age groups significantly. Among many of the existing methods, the fortification of foods with iron salts is the best and most cost-effective strategy for targeting large-scale populations to provide nutritional security. The fortification of foods with iron salts is a challenging task because most iron complexes (ferrous sulfate, ferrous chloride) used in fortification are highly water-soluble, which impart unacceptable organoleptic changes in food vehicles and also causes gastrointestinal problems. However, insoluble iron salts (ferric pyrophosphate) do not cause unacceptable taste or color in food vehicles but low bioavailable. Nanosized iron salts can overcome these concerns. The particle size of iron salts has been reported to play an important role in the absorption of iron. Reduction in the particle size of iron compounds increases its surface area, which in turn improves its solubility in the gastric juice leading to higher absorption. Nanosized iron compound produces minimal organoleptic changes in food vehicles compared to water-soluble iron complexes. Thus nanosized iron salts find potential applications in food fortification to reduce IDA. This paper focuses on providing a complete review of the various iron salts used in IDA, including their bioavailability, the challenges to food fortification, the effects of nanosized iron salts on IDA, and their applications in food fortification. Graphic abstract: Fortification of foods with water-soluble Fe salts imparts unacceptable organoleptic changes in food vehicle and adverse impact on health. However, insoluble iron salts do not cause unacceptable taste or color in food vehicles but low bioavailable. Using Nano-sized iron compound produces minimal organoleptic changes in food vehicles compared to changes produced by water-soluble iron complexes, improves Fe absorption in the gastrointestinal tract and does not cause any health issues.

Formulation and evaluation of novel functional snack bar with amaranth, rolled oat, and unripened banana peel powder.

The present pandemic situation has increased demand for functional foods that enhance all aged groups' people immunity against COVID-19. This factor has led to innovation in snack market because healthy and good quality snack products are lacking. In this study, attempt has been made to develop functional snack bar that is beneficial for malnourished population from various combinations of amaranth grain, oat, and banana peel powder. Among various combinations amaranth grain (60%), oats (25%) and banana peel powder (15%) was found better than other combinations in respect to organoleptic and nutritional quality. Oat and banana peel powder addition increased the contents of protein, mineral, ß-glucan, dietary fibre, essential amino acid, phenolic, and antioxidant activity of functional snack bar. TGA analysis shows that active components present in it were stable even at high temperature which adds benefit to its functional property. Microbial studies of FSB revealed it could be stored up to 60 days without microbial contamination and acceptable by consumer. The cost of a functional snack bar was 9.57 per bar, which was less than market snack bar. This study showed that developed functional snack bar snack increases market's revenue and enables snack market to develop new type snack bar.

Effectiveness-of Calcium Phosphate derivative agents on the prevention and remineralization of caries among children- A systematic review & meta-analysis of randomized controlled trials.

OBJECTIVES: Dental caries among children is a highly prevalent yet easily preventable oral health issue among children. Various calcium phosphate (CaP) derivatives are implicated to exhibit caries preventive potential; however, no study has summarized the anti-caries effectiveness of these agents. This systematic review and meta-analysis sought to assess the caries-preventive and tooth-remineralizing effect of various (CaP) derivative agents compared to no-intervention/placebo or Fluoride (F) use alone among children. MATERIALS AND METHODS: EMBASE, Ovid, PubMed, Scopus, Web of Science, Cochrane central register of controlled trials (CENTRAL), and grey literature were searched for relevant articles up to April 2021. Only English-language articles were included. Total 2636 articles were searched through different databases; out of the 2161 articles were screened after duplicate removal. 26 studies fulfilling the eligibility criteria were included in this systematic review. Methodological quality assessment and quantitative analysis were done using RevMan. GRADE was used to evaluate the certainty of evidence. RESULTS: A total of 26 trials fulfilling the eligibility criteria were included. The meta-analysis of 10 studies revealed that complete white spot lesions (WSLs) regression (RR=1.56; 95% CI, 1.27 to 1.91; P < .0001, I2=0%), post intervention active WSLs (RR=0.80; 95% CI, 0.70 to 0.90; P = .0004, I2=0%) and post intervention Salivary S. mutans count (RR= 0.69; 95% CI, 0.48 to 0.99; P = .47, I2=0%) significantly favored the CaP+F combined therapy as compared to F alone. No significant differences in the lesion area, Delta F, and DIAGNOdent values were observed between the 2 groups. Low certainty of the evidence was found in the present systematic review due to the high/unclear risk of bias, imprecision, and indirectness of included trials. CONCLUSIONS: Topical treatment using CaP+F group showed superior remineralization potential as well as the antibacterial effect on dental caries among children as compared to no intervention and/or placebo or F alone. Apart from CPP-ACP, other CaP derivatives like TCP and fTCP seem to have promising effects in remineralizing early lesions, however, very few trials exist on these potential agents. To provide definitive recommendations in this area, more clinical trials on caries preventive effectiveness of various CaP agents are warranted.

Deletion of a Neuronal Drp1 Activator Protects against Cerebral Ischemia.

Mitochondrial fission catalyzed by dynamin-related protein 1 (Drp1) is necessary for mitochondrial biogenesis and maintenance of healthy mitochondria. However, excessive fission has been associated with multiple neurodegenerative disorders, and we recently reported that mice with smaller mitochondria are sensitized to ischemic stroke injury. Although pharmacological Drp1 inhibition has been put forward as neuroprotective, the specificity and mechanism of the inhibitor used is controversial. Here, we provide genetic evidence that Drp1 inhibition is neuroprotective. Drp1 is activated by dephosphorylation of an inhibitory phosphorylation site, Ser637. We identify Bß2, a mitochondria-localized protein phosphatase 2A (PP2A) regulatory subunit, as a neuron-specific Drp1 activator in vivo Bß2 KO mice of both sexes display elongated mitochondria in neurons and are protected from cerebral ischemic injury. Functionally, deletion of Bß2 and maintained Drp1 Ser637 phosphorylation improved mitochondrial respiratory capacity, Ca2+ homeostasis, and attenuated superoxide production in response to ischemia and excitotoxicity in vitro and ex vivo Last, deletion of Bß2 rescued excessive stroke damage associated with dephosphorylation of Drp1 S637 and mitochondrial fission. These results indicate that the state of mitochondrial connectivity and PP2A/Bß2-mediated dephosphorylation of Drp1 play a critical role in determining the severity of cerebral ischemic injury. Therefore, Bß2 may represent a target for prophylactic neuroprotective therapy in populations at high risk of stroke.SIGNIFICANCE STATEMENT With recent advances in clinical practice including mechanical thrombectomy up to 24 h after the ischemic event, there is resurgent interest in neuroprotective stroke therapies. In this study, we demonstrate reduced stroke damage in the brain of mice lacking the Bß2 regulatory subunit of protein phosphatase 2A, which we have shown previously acts as a positive regulator of the mitochondrial fission enzyme dynamin-related protein 1 (Drp1). Importantly, we provide evidence that deletion of Bß2 can rescue excessive ischemic damage in mice lacking the mitochondrial PKA scaffold AKAP1, apparently via opposing effects on Drp1 S637 phosphorylation. These results highlight reversible phosphorylation in bidirectional regulation of Drp1 activity and identify Bß2 as a potential pharmacological target to protect the brain from stroke injury.

Lymphadenopathy in COVID-19 Vaccine Recipients: Diagnostic Dilemma in Oncologic Patients.

Five cases of axillary lymphadenopathy are presented, which occurred after COVID-19 vaccination and mimicked metastasis in a vulnerable oncologic patient group. Initial radiologic diagnosis raised concerns for metastasis. However, further investigation revealed that patients received COVID-19 vaccinations in the ipsilateral arm prior to imaging. In two cases, lymph node biopsy results confirmed vaccination-related reactive lymphadenopathy. Ipsilateral axillary swelling or lymphadenopathy was reported based on symptoms and physical examination in COVID-19 vaccine trials. Knowledge of the potential for COVID-19 vaccine-related ipsilateral adenopathy is necessary to avoid unnecessary biopsy and change in therapy. © RSNA, 2021.

Staphylococcus aureus adhesion in endovascular infections is controlled by the ArlRS-MgrA signaling cascade.

Staphylococcus aureus is a leading cause of endovascular infections. This bacterial pathogen uses a diverse array of surface adhesins to clump in blood and adhere to vessel walls, leading to endothelial damage, development of intravascular vegetations and secondary infectious foci, and overall disease progression. In this work, we describe a novel strategy used by S. aureus to control adhesion and clumping through activity of the ArlRS two-component regulatory system, and its downstream effector MgrA. Utilizing a combination of in vitro cellular assays, and single-cell atomic force microscopy, we demonstrated that inactivation of this ArlRS-MgrA cascade inhibits S. aureus adhesion to a vast array of relevant host molecules (fibrinogen, fibronectin, von Willebrand factor, collagen), its clumping with fibrinogen, and its attachment to human endothelial cells and vascular structures. This impact on S. aureus adhesion was apparent in low shear environments, and in physiological levels of shear stress, as well as in vivo in mouse models. These effects were likely mediated by the de-repression of giant surface proteins Ebh, SraP, and SasG, caused by inactivation of the ArlRS-MgrA cascade. In our in vitro assays, these giant proteins collectively shielded the function of other surface adhesins and impaired their binding to cognate ligands. Finally, we demonstrated that the ArlRS-MgrA regulatory cascade is a druggable target through the identification of a small-molecule inhibitor of ArlRS signaling. Our findings suggest a novel approach for the pharmacological treatment and prevention of S. aureus endovascular infections through targeting the ArlRS-MgrA regulatory system.