Tranexamic Acid in Patients Undergoing Noncardiac Surgery.

BACKGROUND: Perioperative bleeding is common in patients undergoing noncardiac surgery. Tranexamic acid is an antifibrinolytic drug that may safely decrease such bleeding. METHODS: We conducted a trial involving patients undergoing noncardiac surgery. Patients were randomly assigned to receive tranexamic acid (1-g intravenous bolus) or placebo at the start and end of surgery (reported here) and, with the use of a partial factorial design, a hypotension-avoidance or hypertension-avoidance strategy (not reported here). The primary efficacy outcome was life-threatening bleeding, major bleeding, or bleeding into a critical organ (composite bleeding outcome) at 30 days. The primary safety outcome was myocardial injury after noncardiac surgery, nonhemorrhagic stroke, peripheral arterial thrombosis, or symptomatic proximal venous thromboembolism (composite cardiovascular outcome) at 30 days. To establish the noninferiority of tranexamic acid to placebo for the composite cardiovascular outcome, the upper boundary of the one-sided 97.5% confidence interval for the hazard ratio had to be below 1.125, and the one-sided P value had to be less than 0.025. RESULTS: A total of 9535 patients underwent randomization. A composite bleeding outcome event occurred in 433 of 4757 patients (9.1%) in the tranexamic acid group and in 561 of 4778 patients (11.7%) in the placebo group (hazard ratio, 0.76; 95% confidence interval [CI], 0.67 to 0.87; absolute difference, -2.6 percentage points; 95% CI, -3.8 to -1.4; two-sided P<0.001 for superiority). A composite cardiovascular outcome event occurred in 649 of 4581 patients (14.2%) in the tranexamic acid group and in 639 of 4601 patients (13.9%) in the placebo group (hazard ratio, 1.02; 95% CI, 0.92 to 1.14; upper boundary of the one-sided 97.5% CI, 1.14; absolute difference, 0.3 percentage points; 95% CI, -1.1 to 1.7; one-sided P = 0.04 for noninferiority). CONCLUSIONS: Among patients undergoing noncardiac surgery, the incidence of the composite bleeding outcome was significantly lower with tranexamic acid than with placebo. Although the between-group difference in the composite cardiovascular outcome was small, the noninferiority of tranexamic acid was not established. (Funded by the Canadian Institutes of Health Research and others; POISE-3 ClinicalTrials.gov number, NCT03505723.).

Hypotension-Avoidance Versus Hypertension-Avoidance Strategies in Noncardiac Surgery : An International Randomized Controlled Trial.

BACKGROUND: Among patients having noncardiac surgery, perioperative hemodynamic abnormalities are associated with vascular complications. Uncertainty remains about what intraoperative blood pressure to target and how to manage long-term antihypertensive medications perioperatively. OBJECTIVE: To compare the effects of a hypotension-avoidance and a hypertension-avoidance strategy on major vascular complications after noncardiac surgery. DESIGN: Partial factorial randomized trial of 2 perioperative blood pressure management strategies (reported here) and tranexamic acid versus placebo. (ClinicalTrials.gov: NCT03505723). SETTING: 110 hospitals in 22 countries. PATIENTS: 7490 patients having noncardiac surgery who were at risk for vascular complications and were receiving 1 or more long-term antihypertensive medications. INTERVENTION: In the hypotension-avoidance strategy group, the intraoperative mean arterial pressure target was 80 mm Hg or greater; before and for 2 days after surgery, renin-angiotensin-aldosterone system inhibitors were withheld and the other long-term antihypertensive medications were administered only for systolic blood pressures 130 mm Hg or greater, following an algorithm. In the hypertension-avoidance strategy group, the intraoperative mean arterial pressure target was 60 mm Hg or greater; all antihypertensive medications were continued before and after surgery. MEASUREMENTS: The primary outcome was a composite of vascular death and nonfatal myocardial injury after noncardiac surgery, stroke, and cardiac arrest at 30 days. Outcome adjudicators were masked to treatment assignment. RESULTS: The primary outcome occurred in 520 of 3742 patients (13.9%) in the hypotension-avoidance group and in 524 of 3748 patients (14.0%) in the hypertension-avoidance group (hazard ratio, 0.99 [95% CI, 0.88 to 1.12]; P = 0.92). Results were consistent for patients who used 1 or more than 1 antihypertensive medication in the long term. LIMITATION: Adherence to the assigned strategies was suboptimal; however, results were consistent across different adherence levels. CONCLUSION: In patients having noncardiac surgery, our hypotension-avoidance and hypertension-avoidance strategies resulted in a similar incidence of major vascular complications. PRIMARY FUNDING SOURCE: Canadian Institutes of Health Research, National Health and Medical Research Council (Australia), and Research Grant Council of Hong Kong.

SARS CoV-2 detected in neonatal stool remote from maternal COVID-19 during pregnancy.

BACKGROUND: In utero transmission of SARS coronavirus 2 (SARS-CoV-2) has not been fully investigated. We investigated whether newborns of mothers with COVID-19 during pregnancy might harbor SARS-CoV-2 in the gastrointestinal tract. METHODS: This cohort study investigated stool from 14 newborns born at 25-41 weeks admitted at delivery to our urban academic hospital whose mothers had COVID-19 during pregnancy. Eleven mothers had COVID-19 resolved more than 10 weeks before delivery. Newborn stool was evaluated for SARS-CoV-2 RNA, Spike protein, and induction of inflammatory cytokines interleukin-6 (IL-6) and interferon-γ (IFN-γ) in macrophages. RESULTS: Despite negative SARS CoV-2 nasal PCRs from all newborns, viral RNAs and Spike protein were detected in the stool of 11 out of 14 newborns as early as the first day of life and increased over time in 6. Stool homogenates from all 14 newborns elicited elevated inflammatory IL-6 and IFN-γ from macrophages. Most newborns were clinically well except for one death from gestational autoimmune liver disease and another who developed necrotizing enterocolitis. CONCLUSIONS: These findings suggest in utero transmission of SARS-CoV-2 and possible persistent intestinal viral reservoirs in the newborns. Further investigation is required to understand the mechanisms and their clinical implications. IMPACT: SARS-CoV-2 RNAs or Spike protein was detected in the stool of 11 out of 14 preterm newborns born to mothers with resolved COVID-19 weeks prior to delivery despite negative newborn nasal PCR swabs. These novel findings suggest risk of in utero SARS-CoV-2 transmission to the fetal intestine during gestation. The presence of SARS-CoV-2 RNAs and Spike protein in the intestines of newborns may potentially impact the development of the gut microbiome and the immune system; the long-term health impact on the preterm infants should be further investigated.

Pharmacological modulation and genetic deletion of REV-ERBα and REV-ERBß regulates dendritic cell development.

The nuclear receptors REV-ERBα and REV-ERBß have been demonstrated to play key roles in the regulation of numerous physiological functions, such as metabolism and the circadian rhythm. Recent studies have established the REV-ERBs' roles in immunity, including macrophage and T cell responses. In contrast, their roles in dendritic cells have not been well defined. Dendritic cells are potent antigen presenting cells, connecting microbial sensing and innate immunity to adaptive immune responses. We demonstrate that both REV-ERBα and REV-ERBß expression is upregulated during the course of bone marrow derived dendritic cell (BMDC) differentiation. BMDCs from REV-ERBα and REV-ERBß deficient mice showed enhanced expression of maturation markers like CD86, MHCII, and proinflammatory cytokines. Conversely, treatment of BMDCs with a REV-ERB-specific agonist, SR9009, inhibited the expression of maturation markers and proinflammatory cytokines. Our study suggests the REV-ERBs act as negative regulators of dendritic cell development and activation. These results indicate that pharmacological modulation of REV-ERB activity could be an attractive strategy to modulate DC activation status and for DC-based therapies.

One-year Results of a Factorial Randomized Trial of Aspirin versus Placebo and Clonidine versus Placebo in Patients Having Noncardiac Surgery.

BACKGROUND: The authors previously reported that perioperative aspirin and/or clonidine does not prevent a composite of death or myocardial infarction 30 days after noncardiac surgery. Moreover, aspirin increased the risk of major bleeding and clonidine caused hypotension and bradycardia. Whether these complications produce harm at 1 yr remains unknown. METHODS: The authors randomized 10,010 patients with or at risk of atherosclerosis and scheduled for noncardiac surgery in a 1:1:1:1 ratio to clonidine/aspirin, clonidine/aspirin placebo, clonidine placebo/aspirin, or clonidine placebo/aspirin placebo. Patients started taking aspirin or placebo just before surgery; those not previously taking aspirin continued daily for 30 days, and those taking aspirin previously continued for 7 days. Patients were also randomly assigned to receive clonidine or placebo just before surgery, with the study drug continued for 72 h. RESULTS: Neither aspirin nor clonidine had a significant effect on the primary 1-yr outcome, a composite of death or nonfatal myocardial infarction, with a 1-yr hazard ratio for aspirin of 1.00 (95% CI, 0.89 to 1.12; P = 0.948; 586 patients [11.8%] vs. 589 patients [11.8%]) and a hazard ratio for clonidine of 1.07 (95% CI, 0.96 to 1.20; P = 0.218; 608 patients [12.1%] vs. 567 patients [11.3%]), with effect on death or nonfatal infarction. Reduction in death and nonfatal myocardial infarction from aspirin in patients who previously had percutaneous coronary intervention at 30 days persisted at 1 yr. Specifically, the hazard ratio was 0.58 (95% CI, 0.35 to 0.95) in those with previous percutaneous coronary intervention and 1.03 (95% CI, 0.91to 1.16) in those without (interaction P = 0.033). There was no significant effect of either drug on death, cardiovascular complications, cancer, or chronic incisional pain at 1 yr (all P > 0.1). CONCLUSIONS: Neither perioperative aspirin nor clonidine have significant long-term effects after noncardiac surgery. Perioperative aspirin in patients with previous percutaneous coronary intervention showed persistent benefit at 1 yr, a plausible sub-group effect.

Clonidine in patients undergoing noncardiac surgery.

BACKGROUND: Marked activation of the sympathetic nervous system occurs during and after noncardiac surgery. Low-dose clonidine, which blunts central sympathetic outflow, may prevent perioperative myocardial infarction and death without inducing hemodynamic instability. METHODS: We performed a blinded, randomized trial with a 2-by-2 factorial design to allow separate evaluation of low-dose clonidine versus placebo and low-dose aspirin versus placebo in patients with, or at risk for, atherosclerotic disease who were undergoing noncardiac surgery. A total of 10,010 patients at 135 centers in 23 countries were enrolled. For the comparison of clonidine with placebo, patients were randomly assigned to receive clonidine (0.2 mg per day) or placebo just before surgery, with the study drug continued until 72 hours after surgery. The primary outcome was a composite of death or nonfatal myocardial infarction at 30 days. RESULTS: Clonidine, as compared with placebo, did not reduce the number of primary-outcome events (367 and 339, respectively; hazard ratio with clonidine, 1.08; 95% confidence interval [CI], 0.93 to 1.26; P=0.29). Myocardial infarction occurred in 329 patients (6.6%) assigned to clonidine and in 295 patients (5.9%) assigned to placebo (hazard ratio, 1.11; 95% CI, 0.95 to 1.30; P=0.18). Significantly more patients in the clonidine group than in the placebo group had clinically important hypotension (2385 patients [47.6%] vs. 1854 patients [37.1%]; hazard ratio 1.32; 95% CI, 1.24 to 1.40; P<0.001). Clonidine, as compared with placebo, was associated with an increased rate of nonfatal cardiac arrest (0.3% [16 patients] vs. 0.1% [5 patients]; hazard ratio, 3.20; 95% CI, 1.17 to 8.73; P=0.02). CONCLUSIONS: Administration of low-dose clonidine in patients undergoing noncardiac surgery did not reduce the rate of the composite outcome of death or nonfatal myocardial infarction; it did, however, increase the risk of clinically important hypotension and nonfatal cardiac arrest. (Funded by the Canadian Institutes of Health Research and others; POISE-2 ClinicalTrials.gov number, NCT01082874.).

Aspirin in patients undergoing noncardiac surgery.

BACKGROUND: There is substantial variability in the perioperative administration of aspirin in patients undergoing noncardiac surgery, both among patients who are already on an aspirin regimen and among those who are not. METHODS: Using a 2-by-2 factorial trial design, we randomly assigned 10,010 patients who were preparing to undergo noncardiac surgery and were at risk for vascular complications to receive aspirin or placebo and clonidine or placebo. The results of the aspirin trial are reported here. The patients were stratified according to whether they had not been taking aspirin before the study (initiation stratum, with 5628 patients) or they were already on an aspirin regimen (continuation stratum, with 4382 patients). Patients started taking aspirin (at a dose of 200 mg) or placebo just before surgery and continued it daily (at a dose of 100 mg) for 30 days in the initiation stratum and for 7 days in the continuation stratum, after which patients resumed their regular aspirin regimen. The primary outcome was a composite of death or nonfatal myocardial infarction at 30 days. RESULTS: The primary outcome occurred in 351 of 4998 patients (7.0%) in the aspirin group and in 355 of 5012 patients (7.1%) in the placebo group (hazard ratio in the aspirin group, 0.99; 95% confidence interval [CI], 0.86 to 1.15; P=0.92). Major bleeding was more common in the aspirin group than in the placebo group (230 patients [4.6%] vs. 188 patients [3.8%]; hazard ratio, 1.23; 95% CI, 1.01, to 1.49; P=0.04). The primary and secondary outcome results were similar in the two aspirin strata. CONCLUSIONS: Administration of aspirin before surgery and throughout the early postsurgical period had no significant effect on the rate of a composite of death or nonfatal myocardial infarction but increased the risk of major bleeding. (Funded by the Canadian Institutes of Health Research and others; POISE-2 ClinicalTrials.gov number, NCT01082874.).

T-cell exhaustion in tuberculosis: pitfalls and prospects.

T-cells play an important role in immunity but when these cells are overexposed to specific antigens, their function may decline. This state is usually referred to as exhaustion and the T-cells show reduced proliferation and functions such as cytokine release. T-cell exhaustion has been observed in several cancers as well as in chronic infections such as tuberculosis (TB). In chronic Mycobacterium tuberculosis (Mtb) infection, T-cells may express the exhaustion phenotype and show a progressive loss of secretion of IL-2, IFN-γ and TNF-α. In some cancers and chronic infection models, blocking the exhaustion phenotype can be achieved with the so-called checkpoint inhibitors. This results in tumor control and more effective immunity. However, in the case of TB, the T-cell exhaustion results are quite ambiguous. Hence, there is a need to investigate and explain the contribution of checkpoint at a molecular level to the outcome of events in chronic TB. Such information could help to guide the success of new therapies against chronic TB. This review highlights the mechanism through which T-cells undergo exhaustion and the approaches that can avert such events. This will help to design immunotherapies that can reinvigorate T-cell potency to protect patients from TB.

Clinical role of HER2 gene amplification and chromosome 17: a study on 154 IHC-equivocal cases of invasive breast carcinoma patients.

Accurate evaluation of human epidermal growth factor receptor 2 (HER2) status is quite crucial for invasive breast tumor patients in order to select anti-HER2 therapy for effective clinical outcomes. Immunohistochemistry (IHC) assay is routinely used to evaluate the HER2 oncoprotein overexpression but is unable to explain the chromosomal and genetic alterations and has been considered as a hot issue in IHC-equivocal cases. We investigated these molecular aberrations in correlation with prognostic factors. A cohort of 154 IHC-equivocal (+2) cases was selected and retrospectively analyzed by dual-probe fluorescence in situ hybridization (FISH) assay by using locus-specific HER2 and centromere enumeration probes (CEP17) for the identification of HER2 proto-oncogene amplification and chromosomal copy number per cell, respectively. The data were analyzed by SPSS 16.0 version using chi-square test (p < 0.05). We identified 36 out of 154 cases (23.4 %) showing HER2 gene amplification (average HER2 gene copies per cell >4 or <4 with HER2/CEP17 ratio >2) in concordance with HER2 oncoprotein overexpression, and significant correlation was observed with prognostic parameters including histological type, tumor grade II to III, histology and pathological type, lymphatic invasion, ductal carcinoma in situ (DCIS), and estrogen-positive and progesterone-negative receptors. Of the 154 cases, 18 cases (11.7 %) showed polysomy 17 with CEP17 probe signals per cell ≥3 and 22 cases (14.3 %) presented monosomy 17 (CEP17 probe signals per cell ≤1). Our data indicate that the use of anti-HER2 therapy should not be suggested unless true evaluation of HER2 protein expression is made regarding gene amplification essentially in IHC-ambiguous invasive breast tumors.

Latency-associated protein Acr1 impairs dendritic cell maturation and functionality: a possible mechanism of immune evasion by Mycobacterium tuberculosis.

Mycobacterium tuberculosis (M. tuberculosis) in latently infected individuals survives and thwarts the attempts of eradication by the immune system. During latency, Acr1 is predominantly expressed by the bacterium. However, whether M. tuberculosis exploits its Acr1 in impairing the host immunity remains widely unexplored. Hence, currently we have investigated the role of Acr1 in influencing the differentiation and function of dendritic cells (DCs), which play a cardinal role in innate and adaptive immunity. Therefore, for the first time, we have revealed a novel mechanism of mycobacterial Acr1 in inhibiting the maturation and differentiation of DCs by inducing tolerogenic phenotype by modulating the expression of PD-L1; Tim-3; indoleamine 2, 3-dioxygenase (IDO); and interleukin 10. Furthermore, Acr1 interferes in the differentiation of DCs by targeting STAT-6 and STAT-3 pathways. Continuous activation of STAT-3 inhibited the translocation of NF-κB in Acr1-treated DCs. Furthermore, Acr1 also augmented the induction of regulatory T cells. These DCs displayed decline in their antigen uptake capacity and reduced ability to help T cells. Interestingly, M. tuberculosis exhibited better survival in Acr1-treated DCs. Thus, this study provides a crucial insight into a strategy adopted by M. tuberculosis to survive in the host by impairing the function of DCs.

Decision-making critical amino acids: role in designing peptide vaccines for eliciting Th1 and Th2 immune response.

CD4 T cells play a cardinal role in orchestrating immune system. Differentiation of CD4 T cells to Th1 and Th2 effector subsets depends on multiple factors such as relative intensity of interactions between T cell receptor with peptide-major histocompatibility complex, cytokine milieu, antigen dose, and costimulatory molecules. Literature supports the critical role of peptide's binding affinity to Human Leukocyte Antigens (HLAs) and in the differentiation of naïve CD4 T cells to Th1 and Th2 subsets. However, there exists no definite report addressing very precisely the correlation between physicochemical properties (hydrophobicity, hydrophilicity), pattern, position of amino acids in peptide and their role in skewing immune response towards Th1 and Th2 cells. This may play a significant role in designing peptide vaccines. Hence in the present study, we have evaluated the relationship between amino acid pattern and their influence in differentiation of Th1 and Th2 cells. We have used a data set of 320 peptides, whose role has been already established experimentally in the generation of either Th1 or Th2 immune response. Further, characterization was done based on binding affinity, promiscuity, amino acid pattern and binding conformation of peptides. We have observed that distinct amino acids in peptides elicit either Th1 or Th2 immunity. Consequently, this study signifies that alteration in the sequence and type of selected amino acids in the HLA class II binding peptides can modulate the differentiation of Th1 and Th2 cells. Therefore, this study may have an important implication in providing a platform for designing peptide-based vaccine candidates that can trigger desired Th1 or Th2 response.

Design, synthesis, and biological evaluation of hydrazone incorporated 1,2,4-triazines as anticonvulsant agents.

New hydrazone incorporated triazines were designed and synthesized using an appropriate synthetic route with regard to essential pharmacophores, and evaluated for their anticonvulsant activity through maximal electroshock seizure (MES) and subcutaneous pentylenetetrazole-induced seizure (scPTZ) screenings. Among the tested compounds, 4-[{2-(5-(3-chlorobenzyl)-3-phenyl-1,2,4-triazine-6-yl)hydrazono}methyl]-N,N-dimethylaniline 6k (MES ED50 54.31, scPTZ ED50 92.01) and 4-[{2-(5-(4-chlorobenzyl)-3-phenyl-1,2,4-triazine-6-yl)hydrazono}methyl]-N,N-dimethylaniline 6r (MES ED50 46.05, scPTZ ED50 83.90) emerged as the most active anticonvulsant agents having GABAergic effects. Compounds 6k and 6r also showed lesser CNS depressant effect than the standard drug carbamazepine. To obtain further insights into the binding interactions of these molecules, molecular docking studies were carried out.

Perioperative aspirin and clonidine and risk of acute kidney injury: a randomized clinical trial.

IMPORTANCE: Acute kidney injury, a common complication of surgery, is associated with poor outcomes and high health care costs. Some studies suggest aspirin or clonidine administered during the perioperative period reduces the risk of acute kidney injury; however, these effects are uncertain and each intervention has the potential for harm. OBJECTIVE: To determine whether aspirin compared with placebo, and clonidine compared with placebo, alters the risk of perioperative acute kidney injury. DESIGN, SETTING, AND PARTICIPANTS: A 2 × 2 factorial randomized, blinded, clinical trial of 6905 patients undergoing noncardiac surgery from 88 centers in 22 countries with consecutive patients enrolled between January 2011 and December 2013. INTERVENTIONS: Patients were assigned to take aspirin (200 mg) or placebo 2 to 4 hours before surgery and then aspirin (100 mg) or placebo daily up to 30 days after surgery, and were assigned to take oral clonidine (0.2 mg) or placebo 2 to 4 hours before surgery, and then a transdermal clonidine patch (which provided clonidine at 0.2 mg/d) or placebo patch that remained until 72 hours after surgery. MAIN OUTCOMES AND MEASURES: Acute kidney injury was primarily defined as an increase in serum creatinine concentration from the preoperative concentration by either an increase of 0.3 mg/dL or greater (≥26.5 µmol/L) within 48 hours of surgery or an increase of 50% or greater within 7 days of surgery. RESULTS: Aspirin (n = 3443) vs placebo (n = 3462) did not alter the risk of acute kidney injury (13.4% vs 12.3%, respectively; adjusted relative risk, 1.10; 95% CI, 0.96-1.25). Clonidine (n = 3453) vs placebo (n = 3452) did not alter the risk of acute kidney injury (13.0% vs 12.7%, respectively; adjusted relative risk, 1.03; 95% CI, 0.90-1.18). Aspirin increased the risk of major bleeding. In a post hoc analysis, major bleeding was associated with a greater risk of subsequent acute kidney injury (23.3% when bleeding was present vs 12.3% when bleeding was absent; adjusted hazard ratio, 2.20; 95% CI, 1.72-2.83). Similarly, clonidine increased the risk of clinically important hypotension. In a post hoc analysis, clinically important hypotension was associated with a greater risk of subsequent acute kidney injury (14.3% when hypotension was present vs 11.8% when hypotension was absent; adjusted hazard ratio, 1.34; 95% CI, 1.14-1.58). CONCLUSIONS AND RELEVANCE: Among patients undergoing major noncardiac surgery, neither aspirin nor clonidine administered perioperatively reduced the risk of acute kidney injury. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01082874.

Role of Postoperative Intact Parathyroid Hormone Levels in Predicting Hypocalcaemia after Thyroidectomy.

OBJECTIVE: To determine the sensitivity and specificity of intact parathyroid hormone (iPTH) levels in predicting hypocalcaemia after thyroidectomy. STUDY DESIGN: A descriptive cross-sectional study. Place and Duration of the Study: Department of General Surgery, Shifa International Hospital and Shifa Foundation, Islamabad, from May 2021 to 2022. METHODOLOGY: The sample size was calculated to be 205 with consecutive non-probability sampling. Serum iPTH levels and serum calcium levels were measured postoperatively at 6 hours and 24 hours and recorded in a proforma for analysis. After collection, the data were entered and analysed using SPSS version 24.0. RESULTS: Among 205 patients, 157 (76.6%) were females and 48 (23.4%) were males. At 6 hours postoperatively, 121 (59%) patients had normal iPTH levels and 123 (60%) patients had normal serum calcium levels (p = 0.15). At 24-hour, 130 (63.4%) patients had normal iPTH levels and 92 (44.9%) patients had normal serum calcium levels (p = 0.001). Overall, 8 (3.9%) patients developed symptomatic hypocalcaemia (p = <0.001). The sensitivity and specificity of iPTH levels at ≤15 pg/ml were 100% and 70%, respectively, but at 24 pg/ml cut-off level, the specificity increased to 90% with sensitivity of 100%. CONCLUSION: Low serum iPTH levels at 6 hours after surgery can predict hypocalcaemia in patients undergoing thyroidectomy, even if serum calcium levels appear normal at that time. KEY WORDS: Parathyroid hormone, Serum calcium, Hypocalcaemia, Total thyroidectomy, Calcium homeostasis.

Gut bacteria-derived serotonin promotes immune tolerance in early life.

The gut microbiota promotes immune system development in early life, but the interactions between the gut metabolome and immune cells in the neonatal gut remain largely undefined. Here, we demonstrate that the neonatal gut is uniquely enriched with neurotransmitters, including serotonin, and that specific gut bacteria directly produce serotonin while down-regulating monoamine oxidase A to limit serotonin breakdown. We found that serotonin directly signals to T cells to increase intracellular indole-3-acetaldehdye and inhibit mTOR activation, thereby promoting the differentiation of regulatory T cells, both ex vivo and in vivo in the neonatal intestine. Oral gavage of serotonin into neonatal mice resulted in long-term T cell-mediated antigen-specific immune tolerance toward both dietary antigens and commensal bacteria. Together, our study has uncovered an important role for specific gut bacteria to increase serotonin availability in the neonatal gut and identified a function of gut serotonin in shaping T cell response to dietary antigens and commensal bacteria to promote immune tolerance in early life.

ChatGPT and the Future of Medical Education: Opportunities and Challenges.

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Pharmacist Interventions in Minimizing Drug Related Problems in Diabetes With Co-Existing Hypertension: A Five-Year Overview and Ground Report From India.

Objective: The study aimed to investigate the pharmacist interventions in minimizing drug-related problems in diabetes with co-existing hypertension. Methods: Prospective observational study. Results: Overall, a total of 628 interventions were recommended for 1,914 patients during the 5-year period of study. Among all the interventions, the majority were suggested regarding "substituting the drug" (39%), change in frequency of administration (25%), and addition of drug (14%). Patient compliance status was found significant (p = 0.29 ± 0.07). Conclusion: Clinical pharmacists have a crucial role in minimizing drug related problems. Particularly, there should be a greater emphasis on patient counselling and patient follow-up.

Maternal gut microbiome-induced IgG regulates neonatal gut microbiome and immunity.

The gut microbiome elicits antigen-specific immunoglobulin G (IgG) at steady state that cross-reacts to pathogens to confer protection against systemic infection. The role of gut microbiome-specific IgG antibodies in the development of the gut microbiome and immunity against enteric pathogens in early life, however, remains largely undefined. In this study, we show that gut microbiome-induced maternal IgG is transferred to the neonatal intestine through maternal milk via the neonatal Fc receptor and directly inhibits Citrobacter rodentium colonization and attachment to the mucosa. Enhanced neonatal immunity against oral C. rodentium infection was observed after maternal immunization with a gut microbiome-derived IgG antigen, outer membrane protein A, or induction of IgG-inducing gut bacteria. Furthermore, by generating a gene-targeted mouse model with complete IgG deficiency, we demonstrate that IgG knockout neonates are more susceptible to C. rodentium infection and exhibit alterations of the gut microbiome that promote differentiation of interleukin-17A-producing γδ T cells in the intestine, which persist into adulthood and contribute to increased disease severity in a dextran sulfate sodium-induced mouse model of colitis. Together, our studies have defined a critical role for maternal gut microbiome-specific IgG antibodies in promoting immunity against enteric pathogens and shaping the development of the gut microbiome and immune cells in early life.

Gut microbiota-derived metabolites confer protection against SARS-CoV-2 infection.

The gut microbiome is intricately coupled with immune regulation and metabolism, but its role in Coronavirus Disease 2019 (COVID-19) is not fully understood. Severe and fatal COVID-19 is characterized by poor anti-viral immunity and hypercoagulation, particularly in males. Here, we define multiple pathways by which the gut microbiome protects mammalian hosts from SARS-CoV-2 intranasal infection, both locally and systemically, via production of short-chain fatty acids (SCFAs). SCFAs reduced viral burdens in the airways and intestines by downregulating the SARS-CoV-2 entry receptor, angiotensin-converting enzyme 2 (ACE2), and enhancing adaptive immunity via GPR41 and 43 in male animals. We further identify a novel role for the gut microbiome in regulating systemic coagulation response by limiting megakaryocyte proliferation and platelet turnover via the Sh2b3-Mpl axis. Taken together, our findings have unraveled novel functions of SCFAs and fiber-fermenting gut bacteria to dampen viral entry and hypercoagulation and promote adaptive antiviral immunity.

Effect of a Perioperative Hypotension-Avoidance Strategy Versus a Hypertension-Avoidance Strategy on the Risk of Acute Kidney Injury: A Clinical Research Protocol for a Substudy of the POISE-3 Randomized Clinical Trial.

BACKGROUND: Most patients who take antihypertensive medications continue taking them on the morning of surgery and during the perioperative period. However, growing evidence suggests this practice may contribute to perioperative hypotension and a higher risk of complications. This protocol describes an acute kidney injury substudy of the Perioperative Ischemic Evaluation-3 (POISE-3) trial, which is testing the effect of a perioperative hypotension-avoidance strategy versus a hypertension-avoidance strategy in patients undergoing noncardiac surgery. OBJECTIVE: To conduct a substudy of POISE-3 to determine whether a perioperative hypotension-avoidance strategy reduces the risk of acute kidney injury compared with a hypertension-avoidance strategy. DESIGN: Randomized clinical trial with 1:1 randomization to the intervention (a perioperative hypotension-avoidance strategy) or control (a hypertension-avoidance strategy). INTERVENTION: If the presurgery systolic blood pressure (SBP) is <130 mmHg, all antihypertensive medications are withheld on the morning of surgery. If the SBP is ≥130 mmHg, some medications (but not angiotensin receptor blockers [ACEIs], angiotensin receptor blockers [ARBs], or renin inhibitors) may be continued in a stepwise manner. During surgery, the patients' mean arterial pressure (MAP) is maintained at ≥80 mmHg. During the first 48 hours after surgery, some antihypertensive medications (but not ACEIs, ARBs, or renin inhibitors) may be restarted in a stepwise manner if the SBP is ≥130 mmHg. CONTROL: Patients receive their usual antihypertensive medications before and after surgery. The patients' MAP is maintained at ≥60 mmHg from anesthetic induction until the end of surgery. SETTING: Recruitment from 108 centers in 22 countries from 2018 to 2021. PATIENTS: Patients (~6800) aged ≥45 years having noncardiac surgery who have or are at risk of atherosclerotic disease and who routinely take antihypertensive medications. MEASUREMENTS: The primary outcome of the substudy is postoperative acute kidney injury, defined as an increase in serum creatinine concentration of either ≥26.5 µmol/L (≥0.3 mg/dL) within 48 hours of randomization or ≥50% within 7 days of randomization. METHODS: The primary analysis (intention-to-treat) will examine the relative risk and 95% confidence interval of acute kidney injury in the intervention versus control group. We will repeat the primary analysis using alternative definitions of acute kidney injury and examine effect modification by preexisting chronic kidney disease, defined as a prerandomization estimated glomerular filtration rate <60 mL/min/1.73 m2. RESULTS: Substudy results will be analyzed in 2022. LIMITATIONS: It is not possible to mask patients or providers to the intervention; however, objective measures will be used to assess acute kidney injury. CONCLUSIONS: This substudy will provide generalizable estimates of the effect of a perioperative hypotension-avoidance strategy on the risk of acute kidney injury.

CONTEXTE: La plupart des patients qui prennent des médicaments antihypertenseurs continuent de les prendre le matin d'une intervention chirurgicale et pendant la période périopératoire. De plus en plus de preuves suggèrent que cette pratique pourrait entraîner l'hypotension périopératoire et augmenter le risque de complications. Ce protocole décrit une sous-étude sur l'insuffisance rénale aiguë (IRA) découlant de l'essai Perioperative Ischemic Evaluation-3 (POISE-3). Cet essai teste l'effet d'une stratégie d'évitement de l'hypotension périopératoire par rapport à une stratégie d'évitement de l'hypertension chez des patients qui subissent une chirurgie non cardiaque. OBJECTIFS: Cette sous-étude de l'essai POISE-3 vise à déterminer si une stratégie d'évitement de l'hypotension périopératoire réduit le risque d'IRA comparativement à la stratégie d'évitement de l'hypertension. TYPE D'ÉTUDE: Essai clinique randomisé à répartition 1:1 au groupe intervention (stratégie d'évitement de l'hypotension périopératoire) ou au groupe témoin (stratégie d'évitement de l'hypertension). GROUPE INTERVENTION: Si la pression artérielle systolique (PAS) avant l'opération est <130 mmHg, tous les médicaments antihypertenseurs sont suspendus le matin de la chirurgie. Si la PAS est ≥130 mmHg, certains médicaments (excluant les inhibiteurs de l'enzyme de conversion de l'angiotensine [IECA], les antagonistes du récepteur de l'angiotensine [ARA] ou les inhibiteurs de la rénine) peuvent être poursuivis de façon graduelle. Pendant la chirurgie, la pression artérielle moyenne (PAM) du patient est maintenue à ≥80 mmHg. Dans les 48 heures suivant l'intervention chirurgicale, certains médicaments antihypertenseurs (excluant les IECA, les ARA ou les inhibiteurs de la rénine) peuvent être réintroduits par étapes si la PAS est ≥130 mmHg. GROUPE TÉMOIN: Les patients reçoivent leurs médicaments antihypertenseurs habituels avant et après la chirurgie. La PAM du patient est maintenue à ≥60 mmHg de l'induction de l'anesthésie à la fin de l'intervention chirurgicale. CADRE: Recrutement à partir de 108 centres dans 22 pays entre 2018 à 2021. SUJETS: Des patients (~6 800) âgés de 45 ans et plus atteints d'athérosclérose, ou présentant un risque de l'être, devant subir une chirurgie non cardiaque et prenant des médicaments antihypertenseurs sur une base régulière. MESURES: Le principal critère d'évaluation de cette sous-étude est une IRA postopératoire définie par une hausse d'au moins 26,5 µmol/L (≥0,3 mg/dL) de la créatinine sérique dans les 48 heures suivant la randomisation ou d'au moins 50 % dans les 7 jours suivant la randomisation. MÉTHODOLOGIE: L'analyse primaire (par intention de traiter) examinera le risque relatif d'une IRA et l'intervalle de confiance à 95 % dans le groupe intervention par rapport au groupe témoin. Nous répéterons l'analyse primaire en utilisant d'autres définitions de l'IRA et nous examinerons la modification de l'effet en présence d'une insuffisance rénale préexistante (définie par un DFGe prérandomisation <60 ml/min/1,73 m2). RÉSULTATS: Les résultats de cette sous-étude seront analysés en 2022. LIMITES: Il n'est pas possible de procéder à l'insu des patients ou des prestataires de soins pour cette intervention; des mesures objectives seront toutefois utilisées pour évaluer l'IRA. CONCLUSION: Cette sous-étude fournira des estimations généralisables de l'effet d'une stratégie visant à éviter l'hypotension périopératoire sur le risque d'insuffisance rénale aiguë.