We read with interest the Correspondence by Stefan Lohse and colleagues,1 who evaluated the practicability of pool testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Pooling of samples yields considerable savings of test kits when the prevalence of infection is low because pools with all-negative samples can be discarded with a single test. Lohse and colleagues' findings suggest that pooling up to 30 samples is technically feasible with currently used and commercially available SARS-CoV-2 RT-PCR kits.
Exposure to cocaine and amphetamine structurally reorganizes excitatory neurons in the medial and orbital prefrontal cortices (mPFC and oPFC), inducing dendritic spine proliferation in the mPFC and eliminating spines in the oPFC. Modifications may be causally associated with addiction etiology. Certain cytoskeletal regulatory proteins expressed in the oPFC and implicated in postnatal neural development also regulate behavioral sensitivity to cocaine, potentially opening a window of opportunity for the identification of novel pharmacotherapeutic targets in the treatment of drug abuse disorders. Addiction is characterized by maladaptive decision-making, a loss of control over drug consumption and habit-like drug seeking despite adverse consequences. These cognitive changes may reflect the effects of drugs of abuse on prefrontal cortical neurobiology. Here, we review evidence that amphetamine and cocaine fundamentally remodel the structure of excitatory neurons in the prefrontal cortex. We summarize evidence in particular that these psychostimulants have opposing effects in the medial and orbital prefrontal cortices ('mPFC' and 'oPFC', respectively). For example, amphetamine and cocaine increase dendrite length and spine density in the mPFC, while dendrites are impoverished and dendritic spines are eliminated in the oPFC. We will discuss evidence that certain cytoskeletal regulatory proteins expressed in the oPFC and implicated in postnatal (adolescent) neural development also regulate behavioral sensitivity to cocaine. These findings potentially open a window of opportunity for the identification of novel pharmacotherapeutic targets in the treatment of drug abuse disorders in adults, as well as in drug-vulnerable adolescent populations. Finally, we will discuss the behavioral implications of drug-related dendritic spine elimination in the oPFC, with regard to reversal learning tasks and tasks that assess the development of reward-seeking habits, both used to model aspects of addiction in rodents.
High-dose methotrexate (HDMTX), defined as a dose higher than 500 mg/m2, is used to treat a range of adult and childhood cancers. Although HDMTX is safely administered to most patients, it can cause significant toxicity, including acute kidney injury (AKI) in 2%-12% of patients. Nephrotoxicity results from crystallization of methotrexate in the renal tubular lumen, leading to tubular toxicity. AKI and other toxicities of high-dose methotrexate can lead to significant morbidity, treatment delays, and diminished renal function. Risk factors for methotrexate-associated toxicity include a history of renal dysfunction, volume depletion, acidic urine, and drug interactions. Renal toxicity leads to impaired methotrexate clearance and prolonged exposure to toxic concentrations, which further worsen renal function and exacerbate nonrenal adverse events, including myelosuppression, mucositis, dermatologic toxicity, and hepatotoxicity. Serum creatinine, urine output, and serum methotrexate concentration are monitored to assess renal clearance, with concurrent hydration, urinary alkalinization, and leucovorin rescue to prevent and mitigate AKI and subsequent toxicity. When delayed methotrexate excretion or AKI occurs despite preventive strategies, increased hydration, high-dose leucovorin, and glucarpidase are usually sufficient to allow renal recovery without the need for dialysis. Prompt recognition and effective treatment of AKI and associated toxicities mitigate further toxicity, facilitate renal recovery, and permit patients to receive other chemotherapy or resume HDMTX therapy when additional courses are indicated. IMPLICATIONS FOR PRACTICE: High-dose methotrexate (HDMTX), defined as a dose higher than 500 mg/m2, is used for a range of cancers. Although HDMTX is safely administered to most patients, it can cause significant toxicity, including acute kidney injury (AKI), attributable to crystallization of methotrexate in the renal tubular lumen, leading to tubular toxicity. When AKI occurs despite preventive strategies, increased hydration, high-dose leucovorin, and glucarpidase allow renal recovery without the need for dialysis. This article, based on a review of the current associated literature, provides comprehensive recommendations for prevention of toxicity and, when necessary, detailed treatment guidance to mitigate AKI and subsequent toxicity.
Heparanase is a heparan sulfate degrading endoglycosidase. Previous work has demonstrated that heparanase plays important roles in various biological processes including angiogenesis, wound healing and metastasis. However, the role of heparanase in the post-ischemic brain is not well defined. Transient focal cerebral ischemia in adult mice was induced by ligations of the right middle cerebral artery (MCA) and both common carotid arteries (CCAs). All mice were subjected to bromodeoxyuridine (BrdU) injection and sacrificed at different time points after stroke for immunohistochemical and Western blot analyses. Heparanase expression increased after ischemia in both cell-specific and time-dependent manners. Three to 7 days after stroke, levels of the 50-kD heparanase, basic fibroblast growth factor (FGF-2), and angiopoietin-2 (Ang-2) increased in the peri-infarct region. At early time points, heparanase expression was largely confined to proliferating vascular endothelial cells. At 14 days after ischemia, this expression had shifted to astrocytes in the same region. These data show that cerebral ischemia markedly increases heparanase levels in endothelial cells and then in astrocytes. The unique features of the heparanase upregulation imply that heparanase may play specific roles in the pathological and regenerative processes during the acute and sub-acute/chronic phase in the post-stroke brain.
The safety and efficacy of dipeptidyl peptidase-4 (DPP4) inhibitors as monotherapy or in combination with other oral antidiabetic agents or basal insulin are well established. DPP4 inhibitors stimulate glucose-dependent insulin secretion and inhibit glucagon production. As monotherapy, they reduce the hemoglobin A1c level by about 0.6–0.8%. The addition of a DPP4 inhibitor to basal insulin is an attractive option, because they lower both postprandial and fasting plasma glucose concentrations without increasing the risk of hypoglycemia or weight gain. The present review summarizes the extensive evidence on the combination therapy of DPP4 inhibitors and insulin-based regimens in patients with type 2 diabetes. We focus our discussion on challenging clinical scenarios including patients with chronic renal impairment, elderly persons and hospitalized patients. The evidence indicates that these drugs are highly effective and safe in the elderly and in the presence of mild, moderate and severe renal failure improving glycemic control with low risk of hypoglycemia. In addition, several randomized-controlled trials have shown that the use of DPP4 inhibitors in combination with basal insulin represents an alternative to the basal-bolus insulin regimen in hospitalized patients with type 2 diabetes.
Background
Crohn’s disease (CD) is highly heritable. NOD2 has emerged as the main susceptibility gene among individuals of European ancestry; however, NOD2 does not appear to contribute to CD susceptibility among many non-European populations. Today’s African American (AA) population represents an admixture of West African (80%) and European (20%) ancestry. Since genotype-based tools are becoming increasingly available for CD, it is important that we validate the risk variants in different populations, such as admixed AAs.
Methods
We analyzed the NOD2 variants among admixed AAs (n=321, 240 with CD and 111 healthy controls) and non-admixed West Africans (n=40) by genotyping for 4 known disease-causing NOD variants. We extracted the publically available 1000 Genomes data on NOD2 variants from 500 subjects of West African origin. Association with disease was evaluated by logistic regression.
Results
An association with CD was found for the classical SNP 1007fs (2.6% CD, 0% HC, p=0.012); there was no association when the genotypic and allelic frequencies of the risk alleles were compared for SNPs R702W and G908R. No known NOD2 risk alleles were seen in either the West African cohort or in subjects of African ancestry from the 1000 Genomes project.
Conclusions
The NOD2 gene is a risk for CD in AAs, although the allele frequencies and the attributable risk are much lower compared to Caucasians. The risk alleles are not seen in the West African population suggesting the risk for CD contributed by NOD2 among AAs is due exclusively to recent European admixture
Vascular smooth muscle cells (VSMCs) undergo a phenotypic switch from a differentiated to synthetic phenotype in cardiovascular diseases such as atherosclerosis and restenosis. Our previous studies indicate that transforming growth factor-β (TGF-β) helps to maintain the differentiated phenotype by regulating expression of pro-differentiation genes such as smooth muscle á-actin (SMA) and Calponin (CNN) through reactive oxygen species (ROS) derived from NADPH oxidase 4 (Nox4) in VSMCs. In this study, we investigated the relationship between Nox4 and myocardin-related transcription factor-A (MRTF-A), a transcription factor known to be important in expression of smooth muscle marker genes. Previous work has shown that MRTF-A interacts with the actin-binding protein, palladin, although how this interaction affects MRTF-A function is unclear, as is the role of phosphorylation in MRTF-A activity. We found that Rho kinase (ROCK)-mediated phosphorylation of MRTF-A is a key event in the regulation of SMA and CNN in VSMCs and that this phosphorylation depends upon Nox4-mediated palladin expression. Knockdown of Nox4 using siRNA decreases TGF-β-induced palladin expression and MRTF-A phosphorylation, suggesting redox-sensitive regulation of this signaling pathway. Knockdown of palladin also decreases MRTF-A phosphorylation. These data suggest that Nox4-dependent palladin expression and ROCK regulate phosphorylation of MRTF-A, a critical factor in the regulation of SRF responsive gene expression.
Objectives High-dose vitamin D3increases plasma total 25-hydroxyvitamin D [25(OH)D] in critically ill, ventilated patients; however, to our knowledge, the effect on plasma levels of free (nonprotein-bound) 25(OH)D has not been investigated in critical illness. Moreover, the relationship of free 25(OH)D and the regulation of endogenous antimicrobial peptides (AMPs) remains unknown. The aims of this study were to determine in critically ill adults with respiratory failure the effect of previous high-dose regimens of vitamin D3on free 25(OH)D concentrations, the relationship of free 25(OH)D with circulating cathelicidin (LL-37) and human beta-defensin-2 (hBD-2), and the associations between plasma levels of free 25(OH)D and these AMPs to alveolar macrophage phagocytosis function. Methods In a double blind, randomized controlled trial, critically ill ventilator-dependent adults (N = 30) received enteral vitamin D3(250,000 or 500,000 IU total over 5 d) or placebo. Plasma was obtained serially for concentrations of free 25(OH)D, LL-37, hBD-2, and expression of peripheral blood mononuclear cell human cationic antimicrobial protein (hCAP18) mRNA. Total 25(OH)D and LL-37 concentrations and alveolar macrophage phagocytosis were determined in bronchoalveolar lavage fluid. Results Plasma concentrations of free 25(OH)D over time were correlated with total 25(OH)D levels (r= 0.82; P < 0.001). The increase in free 25(OH)D was greater with the 500 000 IU vitamin D3dose than with the lower dose. The percent change in mRNA expression of hCAP18 was positively associated with percent change in free 25(OH)D at days 7 and 14 (ρ = 0.48; P = 0.04 and ρ = 0.59; P = 0.03, respectively). Additionally, plasma LL-37 levels correlated with the percentage of alveolar macrophages exhibiting phagocytosis (ρ = 0.51; P = 0.04). Conclusions The present study found a dose-related increase in plasma free-25(OH)D levels, which was associated with increasing circulating mRNA expression of hCAP18 over time. There were no correlations between changes in total and free 25(OH)D against plasma LL-37 and hBD-2 concentrations. Larger studies appear warranted to determine the impact of high-dose vitamin D3administration on endogenous AMPs.
Background. The role of suppressive HSV therapy in women coinfected with HSV-2 and HIV-1 taking highly active antiretroviral therapy (HAART) is unclear. Methods. 60 women with HIV-1/HSV-2 coinfection on HAART with plasma HIV-1 viral load (PVL) ≤75 copies/mL were randomized to receive acyclovir (N = 30) or no acyclovir (N = 30). PVL, genital tract (GT) HIV-1, and GT HSV were measured every 4 weeks for one year. Results. Detection of GT HIV-1 was not significantly different in the two arms (OR 1.23, P = 0.67), although this pilot study was underpowered to detect this difference. When PVL was undetectable, the odds of detecting GT HIV were 0.4 times smaller in the acyclovir arm than in the control arm, though this was not statistically significant (P = 0.07). The odds of detecting GT HSV DNA in women receiving acyclovir were significantly lower than in women in the control group, OR 0.38, P < 0.05. Conclusions. Chronic suppressive therapy with acyclovir in HIV-1/HSV-2-positive women on HAART significantly reduces asymptomatic GT HSV shedding, though not GT HIV shedding or PVL. PVL was strongly associated with GT HIV shedding, reinforcing the importance of HAART in decreasing HIV sexual transmission.
by
Sylvia E. Rosas;
Luis M. Ruilope;
Stefan D. Anker;
Bertram Pitt;
Peter Rossing;
Andres Angelo Cadena Bonfanti;
Ricardo Correa-Rotter;
Fernando González;
Carlos Francisco Jaramillo Munoz;
Pablo Pergola;
Guillermo E. Umpierrez;
Andrea Scalise;
Charlie Scott;
Robert Lawatscheck;
Amer Joseph;
George L. Bakris
Rationale & Objective
In FIDELITY, finerenone improved cardiorenal outcomes in patients with chronic kidney disease (CKD) and type 2 diabetes. This analysis explores the efficacy and safety of finerenone in Hispanic patients.
Study Design
Post hoc analysis of the FIDELITY prespecified pooled analysis of the FIDELIO-DKD and FIGARO-DKD randomized control trials.
Setting & Participants
Patients with type 2 diabetes and CKD (urinary albumin-to-creatinine ratio [UACR] of ≥30 to <300 mg/g and estimated glomerular filtration rate [eGFR] of ≥25-≤90 mL/min/1.73 m2, or UACR of ≥300 to ≤5,000 and eGFR of ≥25 mL/min/1.73 m2) on optimized renin–angiotensin system blockade.
Intervention
Finerenone or placebo.
Outcomes
Cardiovascular composite (cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for heart failure); kidney composite (kidney failure, sustained ≥57% eGFR decline, or renal death); change in UACR.
Results
Of 13,026 patients, 2,099 (16.1%) self-identified as Hispanic. Median follow-up was 3.0 years. The cardiovascular composite outcome occurred in 10.0% of Hispanic patients receiving Finerenone and in 12.3% of Hispanic patients receiving placebo (HR, 0.80; 95% CI, 0.62-1.04). This was consistent with non-Hispanic patients (HR, 0.87; 95% CI, 0.79-0.97; Pinteraction= 0.59). The kidney composite outcome occurred in 6.5% and 6.6% of Hispanic patients with finerenone and placebo, respectively (HR, 0.94; 95% CI, 0.67-1.33). The risk reduction was consistent with that observed in non-Hispanic patients (HR, 0.75; 95% CI, 0.64-0.87; Pinteraction= 0.22). Finerenone reduced UACR by 32% at month 4 in both Hispanic and non-Hispanic patients versus placebo (P < 0.001 for both patient groups). The safety profile of finerenone and incidence of hyperkalemia was similar between Hispanic and non-Hispanic patient groups.
Limitations
Small sample size, short follow-up time, and lower treatment adherence in the Hispanic population.
Conclusions
Overall, the efficacy and safety of finerenone were similar in Hispanic and non-Hispanic patients with CKD and type 2 diabetes.