Left atrial shape as a marker of atrial myopathy in embolic stroke of undetermined source.

AIMS: Embolic Stroke of Undetermined Source (ESUS) results in significant morbidity. A left atrial (LA) myopathy is implicated in a proportion of these patients. We hypothesized that LA shape varies by cause of stroke (cardioembolic versus ESUS). METHODS AND RESULTS: 236 ischemic stroke, atrial fibrillation (AF) patients and controls were recruited prospectively. AF was classified as paroxysmal (PAF) or persistent AF (PersAF). Stroke patients comprised cardioembolic stroke (CE) secondary to AF and ESUS. There were 81 AF (47 PAF, 34 PersAF), 50 ESUS, 57 CE patients (subdivided into CE with PAF (CEpaf) and CE with PersAF (CEpers) and 48 controls. Echocardiographic parameters including LA volume, function, and shape/sphericity (3D LA-sphericity and 2D-derived LA-circularity, ellipticity, sphericity and eccentricity indices) were evaluated. Increased LA volume and sphericity with LA dysfunction was present in CE, AF and ESUS groups compared to controls. K-means cluster analysis demonstrated a spectrum of LA myopathy with controls at the lowest and CEpers and PersAF at the upper extremes, with ESUS, PAF and CEpaf being similar and falling between these extremes. After adjusting for age, sex and left ventricular (LV) and LA parameters, LA sphericity markers differentiated ESUS from controls (p < 0.01). CONCLUSIONS: Alterations in LA shape are present in ESUS, AF and CE patients, particularly increased spherical remodelling. The novel markers of LA sphericity proposed may identify LA myopathy in ESUS patients and potentially guide management for secondary prevention.

Astroglial Cells: Emerging Therapeutic Targets in the Management of Traumatic Brain Injury.

Traumatic Brain Injury (TBI) represents a significant health concern, necessitating advanced therapeutic interventions. This detailed review explores the critical roles of astrocytes, key cellular constituents of the central nervous system (CNS), in both the pathophysiology and possible rehabilitation of TBI. Following injury, astrocytes exhibit reactive transformations, differentiating into pro-inflammatory (A1) and neuroprotective (A2) phenotypes. This paper elucidates the interactions of astrocytes with neurons, their role in neuroinflammation, and the potential for their therapeutic exploitation. Emphasized strategies encompass the utilization of endocannabinoid and calcium signaling pathways, hormone-based treatments like 17ß-estradiol, biological therapies employing anti-HBGB1 monoclonal antibodies, gene therapy targeting Connexin 43, and the innovative technique of astrocyte transplantation as a means to repair damaged neural tissues.

The Diagnostic Accuracy of a Fecal Immunochemical Test in Detecting Colorectal Cancer and Advanced Precancerous Colorectal Neoplasia in Patients with Iron Deficiency: A Protocol for Systematic Review and Meta-Analysis.

Background. Iron deficiency (ID) is a common micronutrient deficiency and the leading cause of anemia worldwide. ID can be caused by chronic occult blood loss from colorectal neoplasia including colorectal cancer (CRC) and advanced precancerous colorectal lesions. Current guidelines recommend colonoscopy in both men and postmenopausal women presenting with ID anemia (IDA). However, there is controversy on the investigation of patients presenting with a lower risk of CRC including younger women with ID and those with nonanemic ID (NAID). There is a need for a triaging tool to identify which ID patients may benefit from colonoscopy. The fecal immunochemical test (FIT) is sensitive for CRC screening in an asymptomatic population, but its role in ID patients is unclear. The aim of this study is to conduct a systematic review to determine the diagnostic accuracy of FIT for detecting CRC and advanced precancerous neoplasia in individuals presenting with ID with or without anemia. Methods and Analysis. This protocol conforms with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols and Cochrane Handbook for Systematic Reviews of Diagnostic Test Accuracy. A comprehensive search of the MEDLINE, Embase, and Web of Science databases will be undertaken for studies published after 2010 which involve patients with ID, who completed a FIT in the 6 months prior to colonoscopy, with FIT sensitivity and specificity calculated against the reference standard colonoscopy. The search will be limited to studies conducted after 2010 to reduce variability in colonoscopy quality. Risk of bias assessment will be conducted using the Quality Assessment of Diagnostic Accuracy Studies version 2. FIT sensitivity and specificity will be the primary measure of diagnostic accuracy, and data will be analysed using a random effects meta-analysis. Discussion. This review and meta-analysis will be the first to systematically explore the value of the FIT as a triaging tool for patients with ID. This trial is registered with CRD42022367162.

Electrical detection of RNA cancer biomarkers at the single-molecule level.

Cancer is a significant healthcare issue, and early screening methods based on biomarker analysis in liquid biopsies are promising avenues to reduce mortality rates. Electrical detection of nucleic acids at the single molecule level could enable these applications. We examine the electrical detection of RNA cancer biomarkers (KRAS mutants G12C and G12V) as a single-molecule proof-of-concept electrical biosensor for cancer screening applications. We show that the electrical conductance is highly sensitive to the sequence, allowing discrimination of the mutants from a wild-type KRAS sequence differing in just one base. In addition to this high specificity, our results also show that these biosensors are sensitive down to an individual molecule with a high signal-to-noise ratio. These results pave the way for future miniaturized single-molecule electrical biosensors that could be groundbreaking for cancer screening and other applications.

Mitochondria-associated endoplasmic reticulum membranes (MAMs) and their role in glaucomatous retinal ganglion cell degeneration-a mini review.

Glaucoma is a leading cause of blindness worldwide, commonly associated with elevated intraocular pressure (IOP), leading to degeneration of the optic nerve and death of retinal ganglion cells, the output neurons in the eye. In recent years, many studies have implicated mitochondrial dysfunction as a crucial player in glaucomatous neurodegeneration. Mitochondrial function has been an increasingly researched topic in glaucoma, given its vital role in bioenergetics and propagation of action potentials. One of the most metabolically active tissues in the body characterized by high oxygen consumption is the retina, particularly the retinal ganglion cells (RGCs). RGCs, which have long axons that extend from the eyes to the brain, rely heavily on the energy generated by oxidative phosphorylation for signal transduction, rendering them more vulnerable to oxidative damage. In various glaucoma models, mitochondrial dysfunction and stress from protein aggregates in the endoplasmic reticulum (ER) have been observed in the RGCs. However, it has been shown that the two organelles are connected through a network called mitochondria-associated ER membranes (MAMs); hence this crosstalk in a pathophysiological condition such as glaucoma should be evaluated. Here, we review the current literature suggestive of mitochondrial and ER stress related to glaucoma, indicating potential cross-signaling and the potential roles of MAMs.

Plasmodium-encoded murine IL-6 impairs liver stage infection and elicits long-lasting sterilizing immunity.

Introduction: Plasmodium sporozoites (SPZ) inoculated by Anopheles mosquitoes into the skin of the mammalian host migrate to the liver before infecting hepatocytes. Previous work demonstrated that early production of IL-6 in the liver is detrimental for the parasite growth, contributing to the acquisition of a long-lasting immune protection after immunization with live attenuated parasites. Methods: Considering that IL-6 as a critical pro-inflammatory signal, we explored a novel approach whereby the parasite itself encodes for the murine IL-6 gene. We generated transgenic P. berghei parasites that express murine IL-6 during liver stage development. Results and Discussion: Though IL-6 transgenic SPZ developed into exo-erythrocytic forms in hepatocytes in vitro and in vivo, these parasites were not capable of inducing a blood stage infection in mice. Furthermore, immunization of mice with transgenic IL-6-expressing P. berghei SPZ elicited a long-lasting CD8+ T cell-mediated protective immunity against a subsequent infectious SPZ challenge. Collectively, this study demonstrates that parasite-encoded IL-6 attenuates parasite virulence with abortive liver stage of Plasmodium infection, forming the basis of a novel suicide vaccine strategy to elicit protective antimalarial immunity.

Development and use of an innovative Gap Finding Tool to create a Pharmaceutical Care Model within a paediatric oncology setting.

INTRODUCTION: A paediatric cancer ward is a setting where pharmacists participate in direct patient care, acting as coordinators between the patient, caregivers and healthcare professionals. The aim of the study was to develop a Gap Finding Tool to support the setting up of a pharmaceutical care model at a Paediatric-Adolescent Cancer Ward. METHODS: The Standards of Practice for Clinical Pharmacy Services by the Society of Hospital Pharmacists of Australia Committee of Specialty Practice in Clinical Pharmacy (2013), the American College of Clinical Pharmacy (2014) and the European Association of Hospital Pharmacists (2014) were used to compile the Gap Finding Tool. The developed Tool was tested for content validity by a panel of experts and subsequently implemented over 2 months. RESULTS: The Gap Finding Tool comprised of nine sections with an average of eight statements each about pharmacy services that should be provided at ward level. For each statement, the rater indicates whether these contributions are provided. When the Tool was implemented at the Paediatric-Adolescent Cancer Ward, four major gaps were identified, namely, absence of a clinical pharmacist, lack of medicines information, vetting of chemotherapy prescriptions by pharmacist with limited access to patient data and lack of pharmacist-input on medicines availability. Processes requiring optimisation included discharge medication advice and documentation processes. CONCLUSION: The developed Gap Finding Tool is an innovative tool which is versatile and can be used in ward or ambulatory clinical settings to identify gaps in pharmaceutical processes and services and compare national or regional practices to international standards.

The endothelin receptor antagonist macitentan ameliorates endothelin-mediated vasoconstriction and promotes the survival of retinal ganglion cells in rats.

Glaucoma is a chronic and progressive eye disease, commonly associated with elevated intraocular pressure (IOP) and characterized by optic nerve degeneration, cupping of the optic disc, and loss of retinal ganglion cells (RGCs). The pathological changes in glaucoma are triggered by multiple mechanisms and both mechanical effects and vascular factors are thought to contribute to the etiology of glaucoma. Various studies have shown that endothelin-1 (ET-1), a vasoactive peptide, acting through its G protein coupled receptors, ETA and ETB, plays a pathophysiologic role in glaucoma. However, the mechanisms by which ET-1 contribute to neurodegeneration remain to be completely understood. Our laboratory and others demonstrated that macitentan (MAC), a pan endothelin receptor antagonist, has neuroprotective effects in rodent models of IOP elevation. The current study aimed to determine if oral administration of a dual endothelin antagonist, macitentan, could promote neuroprotection in an acute model of intravitreal administration of ET-1. We demonstrate that vasoconstriction following the intravitreal administration of ET-1 was attenuated by dietary administration of the ETA/ETB dual receptor antagonist, macitentan (5 mg/kg body weight) in retired breeder Brown Norway rats. ET-1 intravitreal injection produced a 40% loss of RGCs, which was significantly lower in macitentan-treated rats. We also evaluated the expression levels of glial fibrillary acidic protein (GFAP) at 24 h and 7 days post intravitreal administration of ET-1 in Brown Norway rats as well as following ET-1 treatment in cultured human optic nerve head astrocytes. We observed that at the 24 h time point the expression levels of GFAP was upregulated (indicative of glial activation) following intravitreal ET-1 administration in both retina and optic nerve head regions. However, following macitentan administration for 7 days after intravitreal ET-1 administration, we observed an upregulation of GFAP expression, compared to untreated rats injected intravitreally with ET-1 alone. Macitentan treatment in ET-1 administered rats showed protection of RGC somas but was not able to preserve axonal integrity and functionality. The endothelin receptor antagonist, macitentan, has neuroprotective effects in the retinas of Brown Norway rats acting through different mechanisms, including enhancement of RGC survival and reduction of ET-1 mediated vasoconstriction.

Neuroprotection of Rodent and Human Retinal Ganglion Cells In Vitro/Ex Vivo by the Hybrid Small Molecule SA-2.

The mechanisms underlying the neuroprotective effects of the hybrid antioxidant-nitric oxide donating compound SA-2 in retinal ganglion cell (RGC) degeneration models were evaluated. The in vitro trophic factor (TF) deprivation model in primary rat RGCs and ex vivo human retinal explants were used to mimic glaucomatous neurodegeneration. Cell survival was assessed after treatment with vehicle or SA-2. In separate experiments, tert-Butyl hydroperoxide (TBHP) and endothelin-3 (ET-3) were used in ex vivo rat retinal explants and primary rat RGCs, respectively, to induce oxidative damage. Mitochondrial and intracellular reactive oxygen species (ROS) were assessed following treatments. In the TF deprivation model, SA-2 treatment produced a significant decrease in apoptotic and dead cell counts in primary RGCs and a significant increase in RGC survival in ex vivo human retinal explants. In the oxidative stress-induced models, a significant decrease in the production of ROS was observed in the SA-2-treated group compared to the vehicle-treated group. Compound SA-2 was neuroprotective against various glaucomatous insults in the rat and human RGCs by reducing apoptosis and decreasing ROS levels. Amelioration of mitochondrial and cellular oxidative stress by SA-2 may be a potential therapeutic strategy for preventing neurodegeneration in glaucomatous RGCs.

Recommendations for Diagnosis and Prevention of Cytomegalovirus-Associated Necrotizing Enterocolitis in Breast-Fed Preterm Infants.

We present the case of a breast-fed preterm infant with postnatally acquired cytomegalovirus (CMV) and severe necrotizing enterocolitis (NEC) associated with CMV. The infant had persistent severe thrombocytopenia with clinical deterioration despite multiple platelet transfusions and maximal medical treatment. Surgical intervention was not feasible owing to the instability of the infant's condition. Upon identification of CMV in urine, intravenous ganciclovir was initiated with significant clinical improvement. We also present a literature review of cases of CMV-related NEC or other gastrointestinal complications in preterm and term infants.

Multiple Copies of flhDC in Paraburkholderia unamae Regulate Flagellar Gene Expression, Motility, and Biofilm Formation.

FlhDC is a heterohexameric complex that acts as a master regulator of flagellar biosynthesis genes in numerous bacteria. Previous studies have identified a single flhDC operon encoding this complex. However, we found that two flhDC loci are present throughout Paraburkholderia, and two additional flhC copies are also present in Paraburkholderia unamae. Systematic deletion analysis in P. unamae of the different flhDC copies showed that one of the operons, flhDC1, plays the predominant role, with deletion of its genes resulting in a severe inhibition of motility and biofilm formation. Expression analysis using promoter-lacZ fusions and real-time quantitative PCR support the primary role of flhDC1 in flagellar gene regulation, with flhDC2 a secondary contributor. Phylogenetic analysis shows the presence of the flhDC1 and flhDC2 operons throughout Paraburkholderia. In contrast, Burkholderia and other bacteria only carry the copy syntenous with flhDC2. The variations in impact each copy of flhDC has on downstream processes indicate that regulation of FlhDC in P. unamae, and likely other Paraburkholderia species, is regulated at least in part by the presence of multiple copies of these genes. IMPORTANCE Motility is important in the colonization of plant roots by beneficial and pathogenic bacteria, with flagella playing essential roles in host cell adhesion, entrance, and biofilm formation. Flagellar biosynthesis is energetically expensive. Its complex regulation by the FlhDC master regulator is well studied in peritrichous flagella expressing enterics. We report the unique presence throughout Paraburkholderia of multiple copies of flhDC. In P. unamae, the flhDC1 copy showed higher expression and a greater effect on swim motility, flagellar development, and regulation of downstream genes, than the flhDC2 copy that is syntenous to flhDC in Escherichia coli and pathogenic Burkholderia spp. The flhDC genes have evolved differently in these plant-growth-promoting bacteria, giving an additional layer of complexity in gene regulation by FlhDC.

A novel luminescence-based ß-arrestin recruitment assay for unmodified receptors.

G protein-coupled receptors (GPCRs) signal through activation of G proteins and subsequent modulation of downstream effectors. More recently, signaling mediated by ß-arrestin has also been implicated in important physiological functions. This has led to great interest in the identification of biased ligands that favor either G protein or ß-arrestin-signaling pathways. However, nearly all screening techniques for measuring ß-arrestin recruitment have required C-terminal receptor modifications that can in principle alter protein interactions and thus signaling. Here, we have developed a novel luminescence-based assay to measure ß-arrestin recruitment to the membrane or early endosomes by unmodified receptors. Our strategy uses NanoLuc, an engineered luciferase from Oplophorus gracilirostris (deep-sea shrimp) that is smaller and brighter than other well-established luciferases. Recently, several publications have explored functional NanoLuc split sites for use in complementation assays. We have identified a unique split site within NanoLuc and fused the corresponding N-terminal fragment to either a plasma membrane or early endosome tether and the C-terminal fragment to ß-arrestins, which form the basis for the MeNArC and EeNArC assays, respectively. Upon receptor activation, ß-arrestin is recruited to the membrane and subsequently internalized in an agonist concentration-dependent manner. This recruitment promotes complementation of the two NanoLuc fragments, thereby reconstituting functional NanoLuc, allowing for quantification of ß-arrestin recruitment with a single luminescence signal. Our assay avoids potential artifacts related to C-terminal receptor modification and has promise as a new generic assay for measuring ß-arrestin recruitment to diverse GPCR types in heterologous or native cells.

A global point prevalence survey of antimicrobial use in neonatal intensive care units: The no-more-antibiotics and resistance (NO-MAS-R) study.

BACKGROUND: Global assessment of antimicrobial agents prescribed to infants in the neonatal intensive care unit (NICU) may inform antimicrobial stewardship efforts. METHODS: We conducted a one-day global point prevalence study of all antimicrobials provided to NICU infants. Demographic, clinical, and microbiologic data were obtained including NICU level, census, birth weight, gestational/chronologic age, diagnoses, antimicrobial therapy (reason for use; length of therapy), antimicrobial stewardship program (ASP), and 30-day in-hospital mortality. FINDINGS: On July 1, 2019, 26% of infants (580/2,265; range, 0-100%; median gestational age, 33 weeks; median birth weight, 1800 g) in 84 NICUs (51, high-income; 33, low-to-middle income) from 29 countries (14, high-income; 15, low-to-middle income) in five continents received ≥1 antimicrobial agent (92%, antibacterial; 19%, antifungal; 4%, antiviral). The most common reasons for antibiotic therapy were "rule-out" sepsis (32%) and "culture-negative" sepsis (16%) with ampicillin (40%), gentamicin (35%), amikacin (19%), vancomycin (15%), and meropenem (9%) used most frequently. For definitive treatment of presumed/confirmed infection, vancomycin (26%), amikacin (20%), and meropenem (16%) were the most prescribed agents. Length of therapy for culture-positive and "culture-negative" infections was 12 days (median; IQR, 8-14) and 7 days (median; IQR, 5-10), respectively. Mortality was 6% (42%, infection-related). An NICU ASP was associated with lower rate of antibiotic utilization (p = 0·02). INTERPRETATION: Global NICU antibiotic use was frequent and prolonged regardless of culture results. NICU-specific ASPs were associated with lower antibiotic utilization rates, suggesting the need for their implementation worldwide. FUNDING: Merck & Co.; The Ohio State University College of Medicine Barnes Medical Student Research Scholarship.

Factors influencing antibiotic duration in culture-negative neonatal early-onset sepsis.

STUDY OBJECTIVE: Little guidance exists on the treatment duration of culture-negative early-onset sepsis (CN-EOS) in neonates, which may lead to prolonged antimicrobial therapy and adverse outcomes. Our objective was to identify risk factors associated with prolonged antibiotic therapy in CN-EOS in neonates. DESIGN: This was a retrospective, matched cohort study of neonates treated with empiric antibiotic therapy for EOS. Infants were sampled with matching of gestational age (GA) into short (≤3 days) and prolonged (>3 days) antibiotic course. Primary outcomes were to identify predictive factors that may be associated with prolonged therapy and compare rates of late-onset sepsis (LOS) and mortality. Secondary outcomes included necrotizing enterocolitis, feeding intolerance, and early development assessment. Predictors associated with prolonged antibiotic therapy were identified using multivariable-adjusted logistic regression. MEASUREMENTS AND MAIN RESULTS: Three hundred infants were included with 150 infants in each group. Mean GA and birthweights were 34.2 ± 4.7 weeks and 2293 ± 991 g, respectively. Male gender, 5-min Apgar <7, immature-to-total neutrophil ratio ≥0.2, C-reactive protein (CRP) ≥10 mg/L, need for vasopressors, and mechanical ventilation were identified as significant predictors for prolonged antibiotics in all infants. Independent of GA, elevated CRP (OR 40.84, 95% CI 15.28-109.15, p < 0.001), need for vasopressors (OR 13.48, 95% CI 3.86-47.15, p < 0.001), and mechanical ventilation (OR 12.98, 95% CI 4.91-34.35, p < 0.001) remained significant predictors of prolonged antibiotic use. Infants in the prolonged courses experienced significant delays in achieving independent oral feeding compared with infants receiving short-course antibiotics (median 17.5 vs. 8 days, p = 0.002, respectively). There were no significant differences in LOS, mortality, or other neonatal comorbidities. CONCLUSIONS: Elevated CRP levels, need for vasopressors, and mechanical ventilation were associated with prolonged antibiotic use in neonates presumptively treated for CN-EOS. Further research is warranted in identifying selective biomarkers for EOS and evaluating whether early antibiotic discontinuation for CN-EOS, despite abnormal laboratory tests/illness severity, is safe and justified.

A three-year post-graduate Doctorate in Pharmacy course incorporating professional, experiential and research activities: A collaborative innovative approach.

This article was migrated. The article was marked as recommended. Background A three-year post-graduate international Doctorate in Pharmacy collaborative course, was launched by the Department of Pharmacy, University of Malta in collaboration with the College of Pharmacy, University of Illinois at Chicago. Aim and rationale To demonstrate that the professional Doctorate in Pharmacy (i) fits the requirements of a Level 8 degree according to the Bologna process, (ii) helps graduates develop competencies and attributes in proficiency in clinical and professional aspects, (iii) has a research component that provides the right level of abilities to participate in research initiatives and to interpret research outcomes, (iv) enables graduates to obtain leadership characteristics. Approach The unique characteristics of the course were evaluated through an outcomes result-oriented measurement. Leadership aspects were measured through policies and strategies presented by students and graduates. Outcomes i) course is in line with the Bologna declaration, ii) research work shown in the dissertation satisfied competencies required iii) research abilities have been examined through a third party and found to be compliant with acquiring of concepts in the design, carrying out, assessment of outcomes and interpretation of results of the research study carried out by each student, and iv) leadership characteristics were shown by the positions taken up by the graduates and early outcomes from these positions. Conclusion Learning activities enable development of professionals able to merge scientific and practice aspects in the evaluation of innovative therapies, the use of medicines and patient monitoring, and in pharmaceutical policy development and regulation. Leadership positions taken up by graduates point to the acquisition of leadership skills by graduates. Next Steps The authors are happy to extend collaboration for this model to be adapted by other institutions for the curricular development entailed in this programme to enhance and improve an innovative aspect in the evolvement of the pharmacy profession on the international scenario.

Evaluation of the Risk Factors for Acute Kidney Injury in Neonates Exposed to Antenatal Indomethacin.

OBJECTIVE: Evidence is limited about important maternal and neonatal risk factors that affect neonatal renal function. The incidence of acute kidney injury (AKI) and identification of associated risk factors in neonates exposed to antenatal indomethacin was studied. METHODS: A retrospective cohort of neonates exposed to antenatal indomethacin within 1 week of delivery was analyzed for development of AKI up to 15 days of life. Adjusted hazard ratios (HRs) and 95% CIs for AKI risk were calculated in time-dependent Cox proportional hazards models. RESULTS: Among 143 neonates with mean gestational age of 28.3 ± 2.4 weeks, AKI occurred in 62 (43.3%), lasting a median duration of 144 hours (IQR, 72-216 hours). Neonates with AKI had greater exposure to postnatal NSAIDs (48.4% vs 9.9%, p < 0.001) and inotropes (37.1% vs 3.7%, p < 0.001) compared with neonates without AKI. In multivariable-adjusted models, increased AKI risk was observed with antenatal indomethacin doses received within 24 to 48 hours (HR, 1.6; 95% CI, 1.28-1.94; p = 0.036) and <24 hours (HR, 2.33; 95% CI, 1.17-4.64; p = 0.016) prior to delivery. Further, postnatal NSAIDs (HR, 2.8; 95% CI, 1.03-7.61; p = 0.044), patent ductus arteriosus (HR, 4.04; 95% CI, 1.27-12.89; p = 0.018), and bloodstream infection (HR, 3.01; 95% CI, 1.37-6.60; p = 0.006) were associated significantly with increased risk of AKI following antenatal indomethacin. Neonates with AKI experienced more bloodstream infection, severe intraventricular hemorrhage, patent ductus arteriosus, respiratory distress syndrome, and longer hospitalization. CONCLUSIONS: Extended risk of AKI with antenatal indomethacin deserves clinical attention among this population at an already increased AKI risk.

Challenges of Vancomycin Dosing and Therapeutic Monitoring in Neonates.

Late-onset sepsis in neonates can lead to significant morbidity and mortality, especially in preterm infants. Vancomycin is commonly prescribed for the treatment of Gram-positive organisms, particularly methicillin-resistant Staphylococcus aureus (MRSA), coagulase-negative staphylococci, and ampicillin-resistant Enterococcus species in adult and pediatric patients. Currently, there is no consensus on optimal dosing and monitoring of vancomycin in neonates. Different vancomycin dosing regimens exist for neonates, but with many of these regimens, obtaining therapeutic trough concentrations can be difficult. In 2011, the Infectious Diseases Society of America recommended vancomycin trough concentrations of 15 to 20 mg/L or an AUC/MIC ratio of ≥400 for severe invasive diseases (e.g., MRSA) in adult and pediatric patients. Owing to recent reports of increased risk of nephrotoxicity associated with vancomycin trough concentrations of 15 to 20 mg/L and AUC/MIC of ≥400, a revised consensus guideline, recently published in 2020, no longer recommends monitoring vancomycin trough concentrations in adult patients. The guideline recommends an AUC/MIC of 400 to 600, which has been found to achieve clinical efficacy while reducing nephrotoxicity. However, these recommendations were derived solely from adult literature, as there are limited clinical outcomes data in pediatric and neonatal patients. Furthermore, owing to the variation of vancomycin pharmacokinetic parameters among the neonatal population, these recommendations for achieving vancomycin AUC/MIC of 400 to 600 in neonates require further investigation. This review will discuss the challenges of achieving optimal vancomycin dosing and monitoring in neonatal patients.

Treatment Potential for LCA5-Associated Leber Congenital Amaurosis.

Purpose: To determine the therapeutic window for gene augmentation for Leber congenital amaurosis (LCA) associated with mutations in LCA5. Methods: Five patients (ages 6-31) with LCA and biallelic LCA5 mutations underwent an ophthalmic examination including optical coherence tomography (SD-OCT), full-field stimulus testing (FST), and pupillometry. The time course of photoreceptor degeneration in the Lca5gt/gt mouse model and the efficacy of subretinal gene augmentation therapy with AAV8-hLCA5 delivered at postnatal day 5 (P5) (early, n = 11 eyes), P15 (mid, n = 14), and P30 (late, n = 13) were assessed using SD-OCT, histologic study, electroretinography (ERG), and pupillometry. Comparisons were made with the human disease. Results: Patients with LCA5-LCA showed a maculopathy with detectable outer nuclear layer (ONL) in the pericentral retina and at least 4 log units of dark-adapted sensitivity loss. The Lca5gt/gt mouse has a similarly severe and rapid photoreceptor degeneration. The ONL became progressively thinner and was undetectable by P60. Rod- and cone-mediated ERGs were severely reduced in amplitudes at P30 and became nondetectable by P60. Subretinal AAV8-hLCA5 administered to Lca5gt/gt mice at P5 and P15, but not at P30, resulted in structural and functional rescue. Conclusions: LCA5-LCA is a particularly severe form of LCA that was recapitulated in the Lca5gt/gt mouse. Gene augmentation resulted in structural and functional rescue in the Lca5gt/gt mouse if delivered before P30. Retained photoreceptors were visible within the central retina in all patients with LCA5-LCA, at a level equivalent to that observed in rescued Lca5gt/gt mice, suggesting a window of opportunity for the treatment of patients with LCA5-LCA.

Integrin α6 mediates the drug resistance of acute lymphoblastic B-cell leukemia.

Resistance to multimodal chemotherapy continues to limit the prognosis of acute lymphoblastic leukemia (ALL). This occurs in part through a process called adhesion-mediated drug resistance, which depends on ALL cell adhesion to the stroma through adhesion molecules, including integrins. Integrin α6 has been implicated in minimal residual disease in ALL and in the migration of ALL cells to the central nervous system. However, it has not been evaluated in the context of chemotherapeutic resistance. Here, we show that the anti-human α6-blocking Ab P5G10 induces apoptosis in primary ALL cells in vitro and sensitizes primary ALL cells to chemotherapy or tyrosine kinase inhibition in vitro and in vivo. We further analyzed the underlying mechanism of α6-associated apoptosis using a conditional knockout model of α6 in murine BCR-ABL1+ B-cell ALL cells and showed that α6-deficient ALL cells underwent apoptosis. In vivo deletion of α6 in combination with tyrosine kinase inhibitor (TKI) treatment was more effective in eradicating ALL than treatment with a TKI (nilotinib) alone. Proteomic analysis revealed that α6 deletion in murine ALL was associated with changes in Src signaling, including the upregulation of phosphorylated Lyn (pTyr507) and Fyn (pTyr530). Thus, our data support α6 as a novel therapeutic target for ALL.

Functional muscle hypertrophy by increased insulin-like growth factor 1 does not require dysferlin.

INTRODUCTION: Dysferlin loss-of-function mutations cause muscular dystrophy, accompanied by impaired membrane repair and muscle weakness. Growth promoting strategies including insulin-like growth factor 1 (IGF-1) could provide benefit but may cause strength loss or be ineffective. The objective of this study was to determine whether locally increased IGF-1 promotes functional muscle hypertrophy in dysferlin-null (Dysf-/- ) mice. METHODS: Muscle-specific transgenic expression and postnatal viral delivery of Igf1 were used in Dysf-/- and control mice. Increased IGF-1 levels were confirmed by enzyme-linked immunosorbent assay. Testing for skeletal muscle mass and function was performed in male and female mice. RESULTS: Muscle hypertrophy occurred in response to increased IGF-1 in mice with and without dysferlin. Male mice showed a more robust response compared with females. Increased IGF-1 did not cause loss of force per cross-sectional area in Dysf-/- muscles. DISCUSSION: We conclude that increased local IGF-1 promotes functional hypertrophy when dysferlin is absent and reestablishes IGF-1 as a potential therapeutic for dysferlinopathies.