Angiotensin Analogs with Divergent Bias Stabilize Distinct Receptor Conformations.

"Biased" G protein-coupled receptor (GPCR) agonists preferentially activate pathways mediated by G proteins or ß-arrestins. Here, we use double electron-electron resonance spectroscopy to probe the changes that ligands induce in the conformational distribution of the angiotensin II type I receptor. Monitoring distances between 10 pairs of nitroxide labels distributed across the intracellular regions enabled mapping of four underlying sets of conformations. Ligands from different functional classes have distinct, characteristic effects on the conformational heterogeneity of the receptor. Compared to angiotensin II, the endogenous agonist, agonists with enhanced Gq coupling more strongly stabilize an "open" conformation with an accessible transducer-binding site. ß-arrestin-biased agonists deficient in Gq coupling do not stabilize this open conformation but instead favor two more occluded conformations. These data suggest a structural mechanism for biased ligand action at the angiotensin receptor that can be exploited to rationally design GPCR-targeting drugs with greater specificity of action.

Molecular details of ruthenium red pore block in TRPV channels.

Transient receptor potential vanilloid (TRPV) channels play a critical role in calcium homeostasis, pain sensation, immunological response, and cancer progression. TRPV channels are blocked by ruthenium red (RR), a universal pore blocker for a wide array of cation channels. Here we use cryo-electron microscopy to reveal the molecular details of RR block in TRPV2 and TRPV5, members of the two TRPV subfamilies. In TRPV2 activated by 2-aminoethoxydiphenyl borate, RR is tightly coordinated in the open selectivity filter, blocking ion flow and preventing channel inactivation. In TRPV5 activated by phosphatidylinositol 4,5-bisphosphate, RR blocks the selectivity filter and closes the lower gate through an interaction with polar residues in the pore vestibule. Together, our results provide a detailed understanding of TRPV subfamily pore block, the dynamic nature of the selectivity filter and allosteric communication between the selectivity filter and lower gate.

KcsA-Kv1.x chimeras with complete ligand-binding sites provide improved predictivity for screening selective Kv1.x blockers.

Despite significant advances in the development of therapeutic interventions targeting autoimmune diseases and chronic inflammatory conditions, lack of effective treatment still poses a high unmet need. Modulating chronically activated T cells through the blockade of the Kv1.3 potassium channel is a promising therapeutic approach; however, developing selective Kv1.3 inhibitors is still an arduous task. Phage display-based high throughput peptide library screening is a rapid and robust approach to develop promising drug candidates; however, it requires solid-phase immobilization of target proteins with their binding site preserved. Historically, the KcsA bacterial channel chimera harboring only the turret region of the human Kv1.3 channel was used for screening campaigns. Nevertheless, literature data suggest that binding to this type of chimera does not correlate well with blocking potency on the native Kv1.3 channels. Therefore, we designed and successfully produced advanced KcsA-Kv1.3, KcsA-Kv1.1, and KcsA-Kv1.2 chimeric proteins in which both the turret and part of the filter regions of the human Kv1.x channels were transferred. These T+F (turret-filter) chimeras showed superior peptide ligand-binding predictivity compared to their T-only versions in novel phage ELISA assays. Phage ELISA binding and competition results supported with electrophysiological data confirmed that the filter region of KcsA-Kv1.x is essential for establishing adequate relative affinity order among selected peptide toxins (Vm24 toxin, Hongotoxin-1, Kaliotoxin-1, Maurotoxin, Stichodactyla toxin) and consequently obtaining more reliable selectivity data. These new findings provide a better screening tool for future drug development efforts and offer insight into the target-ligand interactions of these therapeutically relevant ion channels.

Structural basis for high-voltage activation and subtype-specific inhibition of human Nav1.8.

The dorsal root ganglia-localized voltage-gated sodium (Nav) channel Nav1.8 represents a promising target for developing next-generation analgesics. A prominent characteristic of Nav1.8 is the requirement of more depolarized membrane potential for activation. Here we present the cryogenic electron microscopy structures of human Nav1.8 alone and bound to a selective pore blocker, A-803467, at overall resolutions of 2.7 to 3.2 Å. The first voltage-sensing domain (VSDI) displays three different conformations. Structure-guided mutagenesis identified the extracellular interface between VSDI and the pore domain (PD) to be a determinant for the high-voltage dependence of activation. A-803467 was clearly resolved in the central cavity of the PD, clenching S6IV. Our structure-guided functional characterizations show that two nonligand binding residues, Thr397 on S6I and Gly1406 on S6III, allosterically modulate the channel's sensitivity to A-803467. Comparison of available structures of human Nav channels suggests the extracellular loop region to be a potential site for developing subtype-specific pore-blocking biologics.

Heart failure pharmacotherapy and cancer: pathways and pre-clinical/clinical evidence.

Heart failure (HF) patients have a significantly higher risk of new-onset cancer and cancer-associated mortality, compared to subjects free of HF. While both the prevention and treatment of new-onset HF in patients with cancer have been investigated extensively, less is known about the prevention and treatment of new-onset cancer in patients with HF, and whether and how guideline-directed medical therapy (GDMT) for HF should be modified when cancer is diagnosed in HF patients. The purpose of this review is to elaborate and discuss the effects of pillar HF pharmacotherapies, as well as digoxin and diuretics on cancer, and to identify areas for further research and novel therapeutic strategies. To this end, in this review, (i) proposed effects and mechanisms of action of guideline-directed HF drugs on cancer derived from pre-clinical data will be described, (ii) the evidence from both observational studies and randomized controlled trials on the effects of guideline-directed medical therapy on cancer incidence and cancer-related outcomes, as synthetized by meta-analyses will be reviewed, and (iii) considerations for future pre-clinical and clinical investigations will be provided.

Mechanism and application of ß-adrenoceptor blockers in soft tissue wound healing.

Soft tissue damage stimulates sympathetic nerves to release large amounts of catecholamine hormones which bind to ß-adrenergic receptors (ß-ARs) on the cell membrane surface. It activates the downstream effector molecules and impairs soft tissue wound healing. ß-blockers specifically inhibit ß-ARs activation in acute/chronic skin lesions and ulcerative hemangiomas. They also accelerate soft tissue wound healing by shortening the duration of inflammation, speeding keratinocyte migration and reepithelialization, promoting wound contraction and angiogenesis, and inhibiting bacterial virulence effects. In addition, ß-blockers shorten wound healing periods in patients with severe thermal damage by reducing the hypermetabolic response. While ß-blockers promote/inhibit corneal epithelial cell regeneration and restores limbal stem/progenitor cells function, it could well accelerate/delay corneal wound healing. Given these meaningful effects, a growing number of studies are focused on examining the efficacy and safety of ß-blockers in soft tissue wound repair, including acute and chronic wounds, severe thermal damage, ulcerated infantile hemangioma, corneal wounds, and other soft tissue disorders. However, an intensive investigation on their acting mechanisms is imperatively needed. The purpose of this article is to summerize the roles of ß-blockers in soft tissue wound healing and explore their clinical applications.

Structural studies identify angiotensin II receptor blocker-like compounds as branched-chain ketoacid dehydrogenase kinase inhibitors.

The mammalian mitochondrial branched-chain ketoacid dehydrogenase (BCKD) complex is a multienzyme complex involved in the catabolism of branched-chain amino acids. BCKD is regulated by the BCKD kinase, or BCKDK, which binds to the E2 subunit of BCKD, phosphorylates its E1 subunit, and inhibits enzymatic activity. Inhibition of the BCKD complex results in increased levels of branched-chain amino acids and branched-chain ketoacids, and this buildup has been associated with heart failure, type 2 diabetes mellitus, and nonalcoholic fatty liver disease. To find BCKDK inhibitors for potential treatment of these diseases, we performed both NMR and virtual fragment screening and identified tetrazole-bearing fragments that bind BCKDK at multiple sites. Through structure-based virtual screening expanding from these fragments, the angiotensin receptor blocker class antihypertension drugs and angiotensin receptor blocker-like compounds were discovered to be potent BCKDK inhibitors, suggesting potential new avenues for heart failure treatment combining BCKDK inhibition and antihypertension.

Persistent sodium currents in neurons: potential mechanisms and pharmacological blockers.

Persistent sodium current (INaP) is an important activity-dependent regulator of neuronal excitability. It is involved in a variety of physiological and pathological processes, including pacemaking, prolongation of sensory potentials, neuronal injury, chronic pain and diseases such as epilepsy and amyotrophic lateral sclerosis. Despite its importance, neither the molecular basis nor the regulation of INaP are sufficiently understood. Of particular significance is a solid knowledge and widely accepted consensus about pharmacological tools for analysing the function of INaP and for developing new therapeutic strategies. However, the literature on INaP is heterogeneous, with varying definitions and methodologies used across studies. To address these issues, we provide a systematic review of the current state of knowledge on INaP, with focus on mechanisms and effects of this current in the central nervous system. We provide an overview of the specificity and efficacy of the most widely used INaP blockers: amiodarone, cannabidiol, carbamazepine, cenobamate, eslicarbazepine, ethosuximide, gabapentin, GS967, lacosamide, lamotrigine, lidocaine, NBI-921352, oxcarbazepine, phenytoine, PRAX-562, propofol, ranolazine, riluzole, rufinamide, topiramate, valproaic acid and zonisamide. We conclude that there is strong variance in the pharmacological effects of these drugs, and in the available information. At present, GS967 and riluzole can be regarded bona fide INaP blockers, while phenytoin and lacosamide are blockers that only act on the slowly inactivating component of sodium currents.

The Evolving Role of Calcium Channel Blockers in Hypertension Management: Pharmacological and Clinical Considerations.

Worldwide, hypertension is the leading risk factor for cardiovascular disease and death. An estimated 122 million people, per the American Heart Association in 2023, have been diagnosed with this common condition. It is generally agreed that the primary goal in the treatment of hypertension is to reduce overall blood pressure to below 140/90 mmHg, with a more optimal goal of 130/80 mmHg. Common medications for treating hypertension include calcium channel blockers (CCBs), angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, beta-blockers, and diuretics. CCBs are one of the most widely studied agents and are generally recommended as first-line therapy alone and in combination therapies. This is largely based on the vast knowledge of CCB mechanisms and their minimal side effect profile. CCBs can be separated into two classes: dihydropyridine and non-dihydropyridine. Non-dihydropyridine CCBs act on voltage-dependent L-type calcium channels of cardiac and smooth muscle to decrease muscle contractility. Dihydropyridine CCBs act by vasodilating the peripheral vasculature. For many patients with only mild increases in systolic and diastolic blood pressure (e.g., stage 1 hypertension), the medical literature indicates that CCB monotherapy can be sufficient to control hypertension. In this regard, CCB monotherapy in those with stage 1 hypertension reduced renal and cardiovascular complications compared to other drug classes. Combination therapy with CCBs and angiotensin receptor blockers or angiotensin-converting enzyme inhibitors has been shown to be an effective dual therapy based on recent meta-analyses. This article is a review of calcium channel blockers and their use in treating hypertension with some updated and recent information on studies that have re-examined their use. As for new information, we tried to include some information from recent studies on hypertensive treatment involving calcium channel blockers.

Evaluation of the stopping angiotensin converting enzyme inhibitor compared to angiotensin receptor blocker (STOP ACEi trial) in advanced and progressive chronic kidney disease.

In the STOP-ACEi trial, the outcome was similar whether or not renin-angiotensin system inhibitors (RASi) were discontinued. We now investigate whether the effect of withdrawing angiotensin converting enzyme inhibitors (ACEi) or angiotensin-receptor blockers (ARBs) differed. In this open label trial patients with estimated glomerular filtration rates (eGFR) under 30ml/min per 1.73 m2 and progressive chronic kidney disease (CKD) were randomized to stop or continue RASi. The primary outcome was eGFR at three years. The composite of kidney failure, over 50% fall in eGFR, or kidney replacement therapy (KRT) was also assessed. Of patients randomized, 99 stopped and 123 patients continued ACEi while 104 stopped and 77 continued ARB at baseline. At three years, the eGFR was similar whether or not patients were withdrawn from ACEi or from ARB. Kidney failure or initiation of KRT occurred in 65% of those stopping and 54% continuing ACEi (hazard ratio if stopped, 1.52; 95% Confidence Interval, 1.07 to 2.16) and in 60% on an ARB regardless of randomized group (hazard ratio if stopped, 1.23; 0.83 to 1.81). Kidney failure/Initiation of KRT with over 50% decline in eGFR occurred in 71% of those stopping and 59% continuing ACEi (relative risk if stopped, 1.19; 95% CI, 1.00 to 1.41) and in 65% stopping and 69% continuing ARB (relative risk if stopped, 0.96; 0.79 to 1.16). Thus, neither discontinuing ACEi nor ARB slowed the rate of decline in eGFR. Although discontinuation of ACEi appeared to have more unfavorable effects on kidney outcomes than stopping ARB, the trial was neither designed nor powered to show differences between agents.

Vonoprazan is Efficacious for Treatment of Heartburn in Non-erosive Reflux Disease: A Randomized Trial.

BACKGROUND & AIMS: Potassium-competitive acid blockers have documented efficacy for erosive esophagitis. We performed a randomized trial in United States subjects diagnosed with non-erosive reflux disease of vonoprazan vs placebo for 4 weeks, followed by a 20-week active-treatment extension. METHODS: Adult subjects with heartburn ≥4 days/week during screening without erosive esophagitis on endoscopy were randomized to placebo, vonoprazan 10 mg, or vonoprazan 20 mg. After 4 weeks, subjects on placebo were re-randomized to vonoprazan 10 mg or 20 mg, and those already on vonoprazan continued at the same dose for 20 weeks. Electronic diaries were completed twice daily. The primary endpoint was percentage of days without daytime or nighttime heartburn (24-hour heartburn-free days). RESULTS: Among 772 randomized subjects, the percentage of 24-hour heartburn-free days was 27.7% for placebo vs 44.8% for vonoprazan 10 mg (least squares mean difference, 17.1%; P < .0001) and 44.4% for vonoprazan 20 mg (least squares mean difference, 16.7%; P < .0001). Differences in percentage of subjects with a 24-hour heartburn-free day for vonoprazan 10 mg vs placebo and vonoprazan 20 mg vs placebo were 8.3% and 11.6% on day 1 and 18.1% and 23.2% on day 2. The mean/median percentages of 24-hour heartburn-free days over the extension period were similar across the 4 study arms: 61%-63%/76%-79%. CONCLUSIONS: Vonoprazan reduced heartburn symptoms in subjects diagnosed with non-erosive reflux disease, with the benefit appearing to begin as early as the first day of therapy. Treatment effect persisted after the initial 4-week placebo-controlled period throughout the 20-week extension period. The 2 vonoprazan doses (10 mg and 20 mg) were similar in efficacy. (ClinicalTrials.gov: NCT05195528).

Association Between Vonoprazan and the Risk of Gastric Cancer After Helicobacter pylori Eradication.

BACKGROUND & AIMS: Potassium-competitive acid blockers (PCABs) have been increasingly used to treat upper gastrointestinal disorders, replacing proton pump inhibitors (PPIs). Whereas PPIs are associated with an increased risk of gastric cancer (GC) after Helicobacter pylori (Hp) eradication, it is uncertain whether PCABs carry the same risk. METHODS: Using a population-based claims database in Japan, we identified patients who were prescribed a clarithromycin-based first regimen of Hp eradication between 2015 and 2018. Patients who failed this regimen and those diagnosed with GC before or within 1 year after Hp eradication were excluded. We compared GC incidence between PCAB users and histamine type-2 receptor antagonist (H2RA) users, matching them on the basis of propensity scores calculated with considerations for age, sex, smoking, alcohol consumption, comorbidities, and co-administered medications. PCABs included only vonoprazan in this study. RESULTS: Among 54,055 patients, 568 (1.05%) developed GC during the follow-up period (mean, 3.65 years). The cumulative incidence of GC was 1.64% at 3 years, 2.02% at 4 years, and 2.36% at 5 years in PCAB users and 0.71% at 3 years, 1.04% at 4 years, and 1.22% at 5 years in H2RA users. The use of PCABs was associated with a higher GC risk (matched hazard ratio, 1.92; 95% confidence interval, 1.13-3.25; P = .016). Longer PCAB use and high-dose PCAB use were significantly associated with higher incidence of GC. Sensitivity analyses showed the risk of GC incidence among PCAB users was comparable with that of PPI users. CONCLUSIONS: The use of PCABs was associated with an increased risk of GC among Hp-eradicated patients, with duration/dose response effects.

Heartburn Relief Is the Major Unmet Need for Drug Development in Gastroesophageal Reflux Disease: Threshold Value Analysis.

BACKGROUND AND AIMS: Heartburn symptoms contribute to healthcare-seeking among patients with gastroesophageal reflux disease (GERD). Despite clinical guidance, management is often dictated by insurance restrictions. Several potassium-competitive acid blockers (PCABs) are under development as a new class of therapy. We performed economic analyses to align GERD drug development with the needs of gastroenterologists, insurers and patients in a value-based environment. METHODS: A decision-analytic model was constructed to compare vonoprazan 20 mg daily (an example of a PCAB), common over-the-counter or prescription proton pump inhibitor regimens, and no treatment over a 1-year time horizon. Clinical responses were evaluated based on the proportions of heartburn-free days in a recent phase 3 multicenter trial. Healthcare utilization for persistent reflux symptoms was derived from national observational studies compared with healthy control subjects. Costs and quality-adjusted life years were reported. RESULTS: Without insurance coverage for appropriate therapy, patients spend $4443 and insurers spend $3784 on average per year for inadequately treated GERD symptoms. Our model estimates that PCABs could save at least $3000 in annual costs to patients and insurers, could generate quality-adjusted life year gains (+0.06 per year), and could be cost-saving to insurers as a covered option at a price up to $8.57 per pill, if these drugs are able to demonstrate similar effectiveness to proton pump inhibitors in future trials evaluating heartburn relief and erosive esophagitis healing to regulators. Threshold prices reflect pricing after all pharmacy benefits manager rebates and discounts. DISCUSSION: We demonstrate that aiming GERD-related drug development toward heartburn relief appears critical to align cost-effective incentives for industry and insurers with those of patients and gastroenterologists.

Management of Lower Urinary Tract Symptoms Attributed to Benign Prostatic Hyperplasia (BPH): AUA Guideline Amendment 2023.

PURPOSE: The purpose of this American Urological Association (AUA) Guideline amendment is to provide a useful reference on the effective evidence-based management of male lower urinary tract symptoms secondary/attributed to BPH (LUTS/BPH). MATERIALS AND METHODS: The Minnesota Evidence Review Team searched Ovid MEDLINE, the Cochrane Library, and the Agency for Healthcare Research and Quality (AHRQ) database to identify studies relevant to the management of BPH. The guideline was updated in 2023 to capture eligible literature published between September 2020 and October 2022. When sufficient evidence existed, the body of evidence was assigned a strength rating of A (high), B (moderate), or C (low) for support of Strong, Moderate, or Conditional Recommendations. In the absence of sufficient evidence, additional information is provided as Clinical Principles and Expert Opinions. RESULTS: The BPH amendment resulted in changes to statements/supporting text on combination therapy, photoselective vaporization of the prostate (PVP), water vapor thermal therapy (WVTT), laser enucleation, and prostate artery embolization (PAE). A new statement on temporary implanted prostatic devices (TIPD) was added. In addition, statements on transurethral needle ablation (TUNA) and transurethral microwave thermotherapy (TUMT) were removed and information regarding these legacy technologies was added to the background section. References and the accompanying treatment algorithms were updated to align with the updated text. CONCLUSION: This guideline seeks to improve clinicians' ability to evaluate and treat patients with BPH/LUTS based on currently available evidence. Future studies will be essential to further support these statements to improve patient care.

Natural IgG protects against early dissemination of vesicular stomatitis virus.

Neonatal Fc receptor (FcRn) recycles immunoglobulin G, and inhibition of FcRn is used clinically for treatment of autoimmune diseases. In this work, using the vesicular stomatitis virus (VSV) mouse infection model system, we determined the role of FcRn during virus infection. While induction of neutralizing antibodies and long-term protection of these antibodies was hardly affected in FcRn deficient mice, FcRn deficiency limited the amount of natural IgG (VSV-specific) antibodies. Lack of natural antibodies (nAbs) limited early control of VSV in macrophages, accelerated propagation of virus in several organs, led to the spread of VSV to the neural tissue resulting in fatal outcomes. Adoptive transfer of natural IgG into FcRn deficient mice limited early propagation of VSV in FcRn deficient mice and enhanced survival of FcRn knockout mice. In line with this, vaccination of FcRn mice with very low dose of VSV prior to infection similarly prevented death after infection. In conclusion we determined the importance of nAbs during VSV infection. Lack of FcRn limited nAbs and thereby enhanced the susceptibility to virus infection.

Calcium channel blockers and beta blockers in pediatric supraventricular tachycardia.

INTRODUCTION: Supraventricular tachycardia (SVT) is a common pediatric arrhythmia. Beta blockers (BBs) and calcium channel blockers (CCBs) are used for treatment despite little data examining their use. We describe the prescriptive tendencies, efficacy, and tolerability of BBs and CCBs used in the treatment of pediatric SVT. METHODS AND RESULTS: This is a multicenter retrospective cohort study from three academic children's hospitals. Individuals aged 1-21 years at time of SVT diagnosis initiated on a BB or a CCB between 01/01/2010 and 12/31/2020 were included. Exclusion criteria were pre-excitation, ectopic atrial tachycardia, and hemodynamically significant heart disease. Demographic, comorbidity, symptomatology, and medication data were collected. Treatment success was defined using a composite data abstraction tool. Of 164 patients, 151 received a BB and 13 received a CCB. The success rate on the initial dosage was 46% for both BB and CCB; the success rate following dosage adjustments was also comparable for BBs (98/151, 65%) and CCBs (9/13, 69%). While 27 (18%) BB patients experienced intolerable side effects, no CCB patient did. CONCLUSION: Treatment with a BB or CCB was successful in half of patients. BBs were prescribed more frequently than CCBs but were associated with more side effects.

Clinical presentation and genetic characterization of early-onset atrial fibrillation in patients affected by long QT syndrome: A single-center experience.

INTRODUCTION: Early-onset atrial fibrillation (AF) has already been observed in approximately 2% of patients with genetically proven long QT syndrome (LQTS). This frequency is higher than population-based estimates of early-onset AF. However, the concomitant expression of AF in LQTS is likely underestimated. The purpose of this study was to examine the clinical presentation, genetic background, and outcomes of a cohort of patients with LQTS and early-onset AF referred to a single tertiary center. METHODS: Twenty-seven patients diagnosed with congenital LQTS were included in the study based on the documentation of early-onset (age ≤50 years) clinical or subclinical AF episodes in all available medical records, including standard electrocardiograms, wearable monitor or cardiac implantable electronic devices. RESULTS: Seventeen patients experienced clinical AF during the follow-up period. Subclinical AF was detected in 10 patients through insertable or wearable cardiac monitors. In our series, the mean heart rate during AF episodes was found to be relatively low despite the patients' young age and the low or minimal effective doses of beta-blockers used for QTc interval control. All patients exhibiting LQTS and early-onset AF were genotype positive, carrying mutations in the KCNQ1 (66%), KCNH2, KCNE1, and SCN5A genes. Notably, most of these patients carried the same p.(R231C) mutation in the KCNQ1 gene (59%) and were from the same families, suggesting concurrent expression of familial AF and LQTS. CONCLUSION: LQTS patients are prone to developing clinical and subclinical AF, even at a younger age. The occurrence of early-onset AF in the LQTS population could be more frequent than previously assumed. AF should be considered as a potential dysrhythmia related to LQTS. Our study emphasizes the importance of carefully researching clinical and/or subclinical episodes of AF through strict heart rhythm monitoring in the LQTS population.

Routine beta-blocker therapy after acute coronary syndromes: The end of an era?

BACKGROUND: Beta-blocker therapy, a treatment burdened by side effects including fatigue, erectile dysfunction and depression, was shown to reduce mortality and cardiovascular events after acute coronary syndromes (ACS) in the pre-coronary reperfusion era. Potential mechanisms include protection from ventricular arrhythmias, increased ischaemia threshold and prevention of left ventricular (LV) adverse remodelling. With the advent of early mechanical reperfusion and contemporary pharmacologic secondary prevention, the benefit of beta-blockers after ACS in the absence of LV dysfunction has been challenged. METHODS: The present narrative review discusses the contemporary evidence based on searching the PubMed database and references in identified articles. RESULTS: Recently, the REDUCE-AMI trial-the first adequately powered randomized trial in the reperfusion era to test beta-blocker therapy after myocardial infarction with preserved left ventricular ejection fraction (LVEF)-showed no benefit on the composite of all-cause death or myocardial infarction over a median 3.5-year follow-up. While the benefit of beta-blockers in patients with reduced LVEF remains undisputed, their value in post-ACS patients with mildly reduced systolic function (LVEF 41%-49%) has not been studied in contemporary randomized trials; in this setting, observational studies have suggested a reduction in cardiovascular events with these agents. The adequate duration of beta-blocker therapy remains unknown, but observational data suggests that any mortality benefit may be lost beyond 1-12 months after ACS in patients with LVEF >40%. CONCLUSION: We believe that there is sufficient evidence to abandon routine beta-blocker prescription in post-ACS patients with preserved LV systolic function.

Analysis of Risk Factors for Febrile Neutropenia in Patients with Small-Cell Lung Cancer Receiving Carboplatin Plus Etoposide Therapy.

INTRODUCTION: Febrile neutropenia (FN) is an oncologic emergency requiring immediate empiric antibiotic therapy. Although carboplatin plus etoposide combination chemotherapy is associated with a relatively high frequency of FN, the risk factors are unclear. Hence, this retrospective study aimed to identify predictive markers of carboplatin/etoposide-induced FN. METHODS: We conducted a retrospective cohort analysis of patients with previously untreated small-cell lung cancer (SCLC) who received combination chemotherapy with carboplatin (area under the concentration curve: 5 mg/mL·min, day 1) and etoposide (80 or 100 mg/m2, days 1-3) between July 2007 and June 2022. FN was assessed during the 21 days after initiation of carboplatin and etoposide therapy according to the Japanese Society of Medical Oncology's definition. Fisher's exact test for categorical variables and Mann-Whitney U test for continuous variables were used to compare the two groups. Statistical significance was set at p values <0.05. Explanatory variables with p values <0.05 in the univariate analysis were included in the multivariate logistic regression analysis. RESULTS: Among the 176 eligible patients, the incidence of FN during the first cycle of chemotherapy was 25.0% (44/176). Multivariate analysis revealed that co-administration of proton pump inhibitors (PPIs) or potassium-competitive acid blockers (PCABs) and body mass index (BMI) were significantly associated with FN (p = 0.0035 and 0.0011, respectively). Patients with both co-administration of PPIs or PCABs and a BMI ≤22.509 kg/m2 presented with significantly higher frequencies of FN compared with the other patients (13/24 [54.2%] vs. 31/152 [20.4%] patients; odds ratio: 4.56, 95% confidence interval: 1.70-12.48; p = 0.00147). CONCLUSION: Patients who received carboplatin plus etoposide for SCLC with co-administration of PPIs or PCABs and a BMI ≤22.509 kg/m2 more frequently present with FN than those without the two factors.

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker on oxidative stress and metabolism of elements in kidney of STZ-induced diabetic rats.

In diabetes, increased oxidative stress and impaired trace element metabolism play an important role in the pathogenesis of diabetic nephropathy. The objective of this research was to examine the outcomes of blocking the renin-angiotensin system, using either the angiotensin-converting enzyme inhibitor (ACEI), perindopril, or the angiotensin II type 1 (AT1) receptor blocker, irbesartan, on oxidative stress and trace element levels such as Zn, Mg, Cu, and Fe in the kidneys of diabetic rats that had been induced with streptozotocin. Thirty-two Wistar albino male rats were equally divided into four groups. The first group was used as a control. The second group of rats developed diabetes after receiving a single intraperitoneal dose of STZ. The third and fourth groups of rats had STZ-induced diabetes and received daily dosages of irbesartan (15 mg/kg b.w/day) and perindopril (6 mg/kg b.w/day) treatment, respectively. Biochemical analysis of the kidneys showed a distinct increase in oxidative stress, indicated by heightened levels of malondialdehyde (MDA) and decreased superoxide dismutase (SOD) activities, as well as reduced glutathione (GSH) levels in the kidneys of diabetic rats. In the kidneys of diabetic rats, the mean levels of Fe and Cu were found to be significantly higher than those of the control group. Additionally, the mean levels of Zn and Mg were significantly lower in the diabetic rats compared to the control rats. Both perindopril and irbesartan decreased significantly MDA content and increased SOD activities and GSH levels in the kidneys of rats with diabetes. The Zn and Mg concentrations in the kidneys of diabetic rats treated with perindopril and irbesartan were markedly higher than in untreated STZ-diabetic rats, while the Cu and Fe concentrations were significantly lower. The urinary excretion of rats treated with perindopril and irbesartan showed a pronounced increase in Cu levels, along with a significant reduction in Zn and Mg levels. Although diabetic rats demonstrated degenerative morphological alterations in their kidneys, both therapies also improved diabetes-induced histopathological modifications in the kidneys. Finally, the present results suggest that manipulating the levels of Zn, Mg, Cu, and Fe - either through ACE inhibition or by blocking AT1 receptors - could be advantageous in reducing lipid peroxidation and increasing antioxidant concentration in the kidneys of diabetic rats.