Brain-derived extracellular vesicles as serologic markers of brain injury following cardiac arrest: A pilot feasibility study.

AIM: Assessment of neurologic injury within the immediate hours following out-of-hospital cardiac arrest (OHCA) resuscitation remains a major clinical challenge. Extracellular vesicles (EVs), small bodies derived from cytosolic contents during injury, may provide the opportunity for "liquid biopsy" within hours following resuscitation, as they contain proteins and RNA linked to cell type of origin. We evaluated whether micro-RNA (miRNA) from serologic EVs were associated with post-arrest neurologic outcome. METHODS: We obtained serial blood samples in an OHCA cohort. Using novel microfluidic techniques to isolate EVs based on EV surface marker GluR2 (present on excitatory neuronal dendrites enriched in hippocampal tissue), we employed reverse transcription quantitative polymerase chain reaction (RT-qPCR) methods to measure a panel of miRNAs and tested association with dichotomized modified Rankin Score (mRS) at discharge. RESULTS: EVs were assessed in 27 post-arrest patients between 7/3/2019 and 7/21/2022; 9 patients experienced good outcomes. Several miRNA species including miR-124 were statistically associated with mRS at discharge when measured within 6 hours of resuscitation (AUC = 0.84 for miR-124, p < 0.05). In a Kendall ranked correlation analysis, miRNA associations with outcome were not strongly correlated with standard serologic marker measurements, or amongst themselves, suggesting that miRNA provide distinct information from common protein biomarkers. CONCLUSIONS: This study explores the associations between miRNAs from neuron-derived EVs (NDEs) and circulating protein biomarkers within 6 hours with neurologic outcome, suggesting a panel of very early biomarker may be useful during clinical care. Future work will be required to test larger cohorts with a broader panel of miRNA species.

A LAMP sequencing approach for high-throughput co-detection of SARS-CoV-2 and influenza virus in human saliva.

The COVID-19 pandemic has created an urgent need for rapid, effective, and low-cost SARS-CoV-2 diagnostic testing. Here, we describe COV-ID, an approach that combines RT-LAMP with deep sequencing to detect SARS-CoV-2 in unprocessed human saliva with a low limit of detection (5-10 virions). Based on a multi-dimensional barcoding strategy, COV-ID can be used to test thousands of samples overnight in a single sequencing run with limited labor and laboratory equipment. The sequencing-based readout allows COV-ID to detect multiple amplicons simultaneously, including key controls such as host transcripts and artificial spike-ins, as well as multiple pathogens. Here, we demonstrate this flexibility by simultaneous detection of 4 amplicons in contrived saliva samples: SARS-CoV-2, influenza A, human STATHERIN, and an artificial SARS calibration standard. The approach was validated on clinical saliva samples, where it showed excellent agreement with RT-qPCR. COV-ID can also be performed directly on saliva absorbed on filter paper, simplifying collection logistics and sample handling.

Detection of SARS-CoV-2 with RAPID: A prospective cohort study.

COVID-19 has killed over 6 million people worldwide. Currently available methods to detect SARS-CoV-2 are limited by their cost and need for multistep sample preparation and trained personnel. Therefore, there is an urgent need to develop fast, inexpensive, and scalable point-of-care diagnostics that can be used for mass testing. Between January and March 2021, we obtained 321 anterior nare swab samples from individuals in Philadelphia (PA, USA). For the Real-time Accurate Portable Impedimetric Detection prototype 1.0 (RAPID) test, anterior nare samples were tested via an electrochemical impedance spectroscopy (EIS) approach. The overall sensitivity, specificity, and accuracy of RAPID in this cohort study were 80.6%, 89.0%, and 88.2%, respectively. We present a rapid, accurate, inexpensive (<$5.00 per unit), and scalable test for diagnosing COVID-19 at the point-of-care. We anticipate that further iterations of this approach will enable widespread deployment, large-scale testing, and population-level surveillance.

Multimodality assessment of heart failure with preserved ejection fraction skeletal muscle reveals differences in the machinery of energy fuel metabolism.

AIMS: Skeletal muscle (SkM) abnormalities may impact exercise capacity in patients with heart failure with preserved ejection fraction (HFpEF). We sought to quantify differences in SkM oxidative phosphorylation capacity (OxPhos), fibre composition, and the SkM proteome between HFpEF, hypertensive (HTN), and healthy participants. METHODS AND RESULTS: Fifty-nine subjects (20 healthy, 19 HTN, and 20 HFpEF) performed a maximal-effort cardiopulmonary exercise test to define peak oxygen consumption (VO2, peak ), ventilatory threshold (VT), and VO2 efficiency (ratio of total work performed to O2 consumed). SkM OxPhos was assessed using Creatine Chemical-Exchange Saturation Transfer (CrCEST, n = 51), which quantifies unphosphorylated Cr, before and after plantar flexion exercise. The half-time of Cr recovery (t1/2, Cr ) was taken as a metric of in vivo SkM OxPhos. In a subset of subjects (healthy = 13, HTN = 9, and HFpEF = 12), percutaneous biopsy of the vastus lateralis was performed for myofibre typing, mitochondrial morphology, and proteomic and phosphoproteomic analysis. HFpEF subjects demonstrated lower VO2,peak , VT, and VO2 efficiency than either control group (all P < 0.05). The t1/2, Cr was significantly longer in HFpEF (P = 0.005), indicative of impaired SkM OxPhos, and correlated with cycle ergometry exercise parameters. HFpEF SkM contained fewer Type I myofibres (P = 0.003). Proteomic analyses demonstrated (a) reduced levels of proteins related to OxPhos that correlated with exercise capacity and (b) reduced ERK signalling in HFpEF. CONCLUSIONS: Heart failure with preserved ejection fraction patients demonstrate impaired functional capacity and SkM OxPhos. Reductions in the proportions of Type I myofibres, proteins required for OxPhos, and altered phosphorylation signalling in the SkM may contribute to exercise intolerance in HFpEF.

D-Dimer and Fibrin Degradation Products Impair Platelet Signaling: Plasma D-Dimer Is a Predictor and Mediator of Platelet Dysfunction During Trauma.

BACKGROUND: Platelet dysfunction often accompanies trauma-induced coagulopathy. Because soluble fibrin impairs platelet glycoprotein VI (GPVI) signaling and platelets of trauma patients can display impaired calcium mobilization, we explored the role of fibrinolysis on platelet dysfunction during trauma. METHODS: Convulxin-induced GPVI calcium mobilization was investigated in healthy platelet-rich plasma (PRP) pretreated with thrombin and tissue plasminogen activator (tPA). Blood samples from healthy participants (n = 7) and trauma patients (n = 22) were tested for platelet calcium mobilization, plasma D-dimer, platelet D-dimer binding (via flow cytometry), and platelet lumi-aggregometry. RESULTS: For healthy platelets, maximal platelet dysfunction was observed when cross-linked soluble fibrin (no tPA) or cross-linked fibrin degradation products (FDPs) were generated in suspension before convulxin stimulation. Lack of fibrin polymerization (inhibited by Gly-Pro-Arg-Pro [GPRP]) or lack of factor XIIIa cross-linking (T101-inhibited) restored GPVI signaling, whereas non-cross-linked FDPs only partially blocked signaling induced by convulxin. In addition, D-dimer added to healthy PRP impaired platelet aggregation and dense granule release induced by various agonists. Plasma D-dimer level was strongly correlated (R = 0.8236) with platelet dysfunction as measured by platelet calcium mobilization induced with various agonists. By 48 to 120 h after trauma, plasma D-dimer levels declined, and platelet function increased significantly but not to healthy levels. Trauma platelets displayed elevated D-dimer binding that was only partially reduced by αIIbß3-inhibitor GR144053. After 60-minute incubation, washed healthy platelets resuspended in plasma from trauma patients captured approximately 10 000 D-dimer equivalents per platelet. CONCLUSIONS: During trauma, D-dimer and FDPs inhibit platelets, potentially via GPVI and integrin αIIbß3 engagement, contributing to a fibrinolysis-dependent platelet loss-of-function phenotype.

Platelet dysfunction during trauma involves diverse signaling pathways and an inhibitory activity in patient-derived plasma.

BACKGROUND: Trauma-induced coagulopathy occurs in about 25% of injured patients and accounts for about 10% of deaths worldwide. Upon injury, hemostatic function may decline due to vascular dysfunction, clotting factor deficiencies, hyperfibrinolysis, and/or platelet dysfunction. We investigated agonist-induced calcium signaling in platelets obtained over time from trauma patients. METHODS: Platelets from trauma patients and healthy donors were monitored via intracellular calcium mobilization and flow cytometry markers (α2bß3 activation, P-selectin display, and phosphatidylserine exposure) following stimulation with a panel of agonists (adenosine 5'-diphosphate sodium salt, U46619, convulxin, PAR-1/4 activating peptides, iloprost) used in isolation or in pairwise tests. Furthermore, healthy donor platelets were tested in heterologous plasma isolated from healthy subjects and trauma patients. RESULTS: When exposed to agonists over the first 24 hours postinjury, trauma patient platelets mobilized less calcium in comparison to healthy platelets. Partial recovery of platelet activity was observed in about a third of patients after 120 hours, although not fully obtaining healthy baseline function. Flow cytometry markers of trauma platelets were similar to healthy platelets prior to stimulation, but were depressed in trauma platelets stimulated with adenosine 5'-diphosphate sodium salt or convulxin. Also, washed healthy platelets showed a significant reduction in calcium mobilization when reconstituted in plasma from trauma patients, relative to healthy plasma, at all plasma doses tested. CONCLUSION: Platelet dysfunction in trauma patients included poor response to multiple agonists relevant to hemostatic function. Furthermore, the inhibitor effect of patient plasma on healthy platelets suggests that soluble plasma species may downregulate endogenous or transfused platelets during trauma.

Nicotinamide mononucleotide preserves mitochondrial function and increases survival in hemorrhagic shock.

Hemorrhagic shock depletes nicotinamide adenine dinucleotide (NAD) and causes metabolic derangements that, in severe cases, cannot be overcome, even after restoration of blood volume and pressure. However, current strategies to treat acute blood loss do not target cellular metabolism. We hypothesized that supplemental nicotinamide mononucleotide (NMN), the immediate biosynthetic precursor to NAD, would support cellular energetics and enhance physiologic resilience to hemorrhagic shock. In a rodent model of decompensated hemorrhagic shock, rats receiving NMN displayed significantly reduced lactic acidosis and serum IL-6 levels, two strong predictors of mortality in human patients. In both livers and kidneys, NMN increased NAD levels and prevented mitochondrial dysfunction. Moreover, NMN preserved mitochondrial function in isolated hepatocytes cocultured with proinflammatory cytokines, indicating a cell-autonomous protective effect that is independent from the reduction in circulating IL-6. In kidneys, but not in livers, NMN was sufficient to prevent ATP loss following shock and resuscitation. Overall, NMN increased the time animals could sustain severe shock before requiring resuscitation by nearly 25% and significantly improved survival after resuscitation (P = 0.018), whether NMN was given as a pretreatment or only as an adjunct during resuscitation. Thus, we demonstrate that NMN substantially mitigates inflammation, improves cellular metabolism, and promotes survival following hemorrhagic shock.

Nicotinamide adenine dinucleotide is transported into mammalian mitochondria.

Mitochondrial NAD levels influence fuel selection, circadian rhythms, and cell survival under stress. It has alternately been argued that NAD in mammalian mitochondria arises from import of cytosolic nicotinamide (NAM), nicotinamide mononucleotide (NMN), or NAD itself. We provide evidence that murine and human mitochondria take up intact NAD. Isolated mitochondria preparations cannot make NAD from NAM, and while NAD is synthesized from NMN, it does not localize to the mitochondrial matrix or effectively support oxidative phosphorylation. Treating cells with nicotinamide riboside that is isotopically labeled on the nicotinamide and ribose moieties results in the appearance of doubly labeled NAD within mitochondria. Analogous experiments with doubly labeled nicotinic acid riboside (labeling cytosolic NAD without labeling NMN) demonstrate that NAD(H) is the imported species. Our results challenge the long-held view that the mitochondrial inner membrane is impermeable to pyridine nucleotides and suggest the existence of an unrecognized mammalian NAD (or NADH) transporter.

Loss of NAD Homeostasis Leads to Progressive and Reversible Degeneration of Skeletal Muscle.

NAD is an obligate co-factor for the catabolism of metabolic fuels in all cell types. However, the availability of NAD in several tissues can become limited during genotoxic stress and the course of natural aging. The point at which NAD restriction imposes functional limitations on tissue physiology remains unknown. We examined this question in murine skeletal muscle by specifically depleting Nampt, an essential enzyme in the NAD salvage pathway. Knockout mice exhibited a dramatic 85% decline in intramuscular NAD content, accompanied by fiber degeneration and progressive loss of both muscle strength and treadmill endurance. Administration of the NAD precursor nicotinamide riboside rapidly ameliorated functional deficits and restored muscle mass despite having only a modest effect on the intramuscular NAD pool. Additionally, lifelong overexpression of Nampt preserved muscle NAD levels and exercise capacity in aged mice, supporting a critical role for tissue-autonomous NAD homeostasis in maintaining muscle mass and function.

Purinergic glio-endothelial coupling during neuronal activity: role of P2Y1 receptors and eNOS in functional hyperemia in the mouse somatosensory cortex.

Impairment of moment-to-moment adjustment of cerebral blood flow (CBF) via neurovascular coupling is thought to play a critical role in the genesis of cognitive impairment associated with aging and pathological conditions associated with accelerated cerebromicrovascular aging (e.g., hypertension, obesity). Although previous studies demonstrate that endothelial dysfunction plays a critical role in neurovascular uncoupling in these conditions, the role of endothelial NO mediation in neurovascular coupling responses is not well understood. To establish the link between endothelial function and functional hyperemia, neurovascular coupling responses were studied in mutant mice overexpressing or deficient in endothelial NO synthase (eNOS), and the role of P2Y1 receptors in purinergic glioendothelial coupling was assessed. We found that genetic depletion of eNOS (eNOS(-/-)) and pharmacological inhibition of NO synthesis significantly decreased the CBF responses in the somatosensory cortex evoked by whisker stimulation and by administration of ATP. Overexpression of eNOS enhanced NO mediation of functional hyperemia. In control mice, the selective and potent P2Y1 receptor antagonist MRS2179 attenuated both whisker stimulation-induced and ATP-mediated CBF responses, whereas, in eNOS(-/-) mice, the inhibitory effects of MRS2179 were blunted. Collectively, our findings provide additional evidence for purinergic glio-endothelial coupling during neuronal activity, highlighting the role of ATP-mediated activation of eNOS via P2Y1 receptors in functional hyperemia.

Uso de surfacen en recién nacidos con dificultad respiratoria / Use of surfacen in newborns with respiratory distress

INTRODUCCIÓN: en la última década se han dirigido esfuerzos investigativos a determinar las ventajas del uso profiláctico del surfactante exógeno sobre la terapéutica de rescate del medicamento. Cuba ha desarrollado un surfactante natural heterólogo de origen porcino (Surfacen). OBJETIVOS: evaluar el uso de Surfacen en recién nacidos con síndrome de distrés respiratorio, e identificar la relación entre el momento de la administración del medicamento con la duración de la ventilación mecánica, y el estado de los pacientes al egreso. MÉTODOS: se realizó un estudio descriptivo de corte transversal de los recién nacidos que ingresaron en el servicio de Neonatología del Hospital General Universitario "Dr. Enrique Cabrera", entre enero de 2009 y diciembre de 2011. El universo estuvo constituido por 86 recién nacidos; de ellos, el 87 % con menos de 33 semanas, recibió el medicamento. De igual forma se le administró al 92,2 % de los niños con menos de 1 500 g y más de 750 g, y al 86,8 % con acidosis respiratoria. El 70,9 % de los pacientes tenían un síndrome de distrés respiratorio como diagnóstico inicial, mientras que al egreso el mayor porcentaje correspondió a neonatos con infección neonatal. CONCLUSIONES: se encontró una asociación estadísticamente significativa entre el momento de la administración de Surfacen y el número de días que estuvieron ventilados los neonatos, así como entre la administración de Surfacen posterior a las 2 horas, y la muerte del paciente.

INTRODUCTION: during the last decade, several research studies have devoted to determine the advantages of the prophylactic use of exogenous surfactant over the rescue therapeutic effect of the drug. Cuba has developed a heterologous natural surfactant of swine origin called Surfacen. OBJECTIVEs: to evaluate the use of Surfacen in newborns with respiratory distress syndrome and to identify the association of the time of drug administration with the duration of mechanical ventilation and the patient's condition on discharge from hospital. METHODS: a cross-sectional study of newborns who were admitted to the neonatology service of "Dr. Enrique Cabrera" general university hospital conducted from January 2009 to December 2011. The universe of study was 86 newborns, 87 % of whom were under 33 weeks of age and had received Surfacen. It was also given to 92.2 % of neonates weighing 750 g to 1 500 g and to 86.8 % with respiratory acidosis. In the study group, 70.9 % of patients had respiratory distress syndrome as initial diagnosis whereas on discharge, the newborns with some neonatal infection accounted for the highest percentage. CONCLUSIONS: there was a significant statistical association between the time of Surfacen administration and the duration of the mechanical ventilation, as well as the Surfacen administration two hours after birth and the death of the patient.

Uso de Surfacen en recién nacidos con dificultad respiratoria / Use of Surfacen in newborns with respiratory distress

Introducción: en la última década se han dirigido esfuerzos investigativos a determinar las ventajas del uso profiláctico del surfactante exógeno sobre la terapéutica de rescate del medicamento. Cuba ha desarrollado un surfactante natural heterólogo de origen porcino (Surfacen).Objetivos: evaluar el uso de Surfacen en recién nacidos con síndrome de distrés respiratorio, e identificar la relación entre el momento de la administración del medicamento con la duración de la ventilación mecánica, y el estado de los pacientes al egreso.Métodos: se realizó un estudio descriptivo de corte transversal de los recién nacidos que ingresaron en el servicio de Neonatología del Hospital General Universitario Dr. Enrique Cabrera, entre enero de 2009 y diciembre de 2011. El universo estuvo constituido por 86 recién nacidos; de ellos, el 87 por ciento con menos de 33 semanas, recibió el medicamento. De igual forma se le administró al 92,2 por ciento de los niños con menos de 1 500 g y más de 750 g, y al 86,8 por ciento con acidosis respiratoria. El 70,9 por ciento de los pacientes tenían un síndrome de distrés respiratorio como diagnóstico inicial, mientras que al egreso el mayor porcentaje correspondió a neonatos con infección neonatal.Conclusiones: se encontró una asociación estadísticamente significativa entre el momento de la administración de Surfacen y el número de días que estuvieron ventilados los neonatos, así como entre la administración de Surfacen posterior a las 2 horas, y la muerte del paciente(AU)

Introduction: during the last decade, several research studies have devoted to determine the advantages of the prophylactic use of exogenous surfactant over the rescue therapeutic effect of the drug. Cuba has developed a heterologous natural surfactant of swine origin called Surfacen.Objectives: to evaluate the use of Surfacen in newborns with respiratory distress syndrome and to identify the association of the time of drug administration with the duration of mechanical ventilation and the patient's condition on discharge from hospital.Methods: a cross-sectional study of newborns who were admitted to the neonatology service of Dr. Enrique Cabrera general university hospital conducted from January 2009 to December 2011. The universe of study was 86 newborns, 87 percent of whom were under 33 weeks of age and had received Surfacen. It was also given to 92.2 percent of neonates weighing 750 g to 1 500 g and to 86.8 percent with respiratory acidosis. In the study group, 70.9 percent of patients had respiratory distress syndrome as initial diagnosis whereas on discharge, the newborns with some neonatal infection accounted for the highest percentage.Conclusions: there was a significant statistical association between the time of Surfacen administration and the duration of the mechanical ventilation, as well as the Surfacen administration two hours after birth and the death of the patient(AU)

Mutations of human NARS2, encoding the mitochondrial asparaginyl-tRNA synthetase, cause nonsyndromic deafness and Leigh syndrome.

Here we demonstrate association of variants in the mitochondrial asparaginyl-tRNA synthetase NARS2 with human hearing loss and Leigh syndrome. A homozygous missense mutation ([c.637G>T; p.Val213Phe]) is the underlying cause of nonsyndromic hearing loss (DFNB94) and compound heterozygous mutations ([c.969T>A; p.Tyr323*] + [c.1142A>G; p.Asn381Ser]) result in mitochondrial respiratory chain deficiency and Leigh syndrome, which is a neurodegenerative disease characterized by symmetric, bilateral lesions in the basal ganglia, thalamus, and brain stem. The severity of the genetic lesions and their effects on NARS2 protein structure cosegregate with the phenotype. A hypothetical truncated NARS2 protein, secondary to the Leigh syndrome mutation p.Tyr323* is not detectable and p.Asn381Ser further decreases NARS2 protein levels in patient fibroblasts. p.Asn381Ser also disrupts dimerization of NARS2, while the hearing loss p.Val213Phe variant has no effect on NARS2 oligomerization. Additionally we demonstrate decreased steady-state levels of mt-tRNAAsn in fibroblasts from the Leigh syndrome patients. In these cells we show that a decrease in oxygen consumption rates (OCR) and electron transport chain (ETC) activity can be rescued by overexpression of wild type NARS2. However, overexpression of the hearing loss associated p.Val213Phe mutant protein in these fibroblasts cannot complement the OCR and ETC defects. Our findings establish lesions in NARS2 as a new cause for nonsyndromic hearing loss and Leigh syndrome.

Retinopatía del prematuro / Retinopathy of prematurity

INTRODUCCIÓN: después de un parto pretérmino, múltiples factores pueden provocar, primero una detención, y luego un crecimiento anormal de los vasos de la retina, y producir la retinopatía del prematuro. OBJETIVO: caracterizar el patrón clínico epidemiológico de la retinopatía del prematuro en recién nacidos menores de 35 semanas de gestación y peso al nacer inferior o igual a 1 700 g. MÉTODOS: estudio observacional, descriptivo, transversal y retrospectivo de los nacidos con menos de 35 semanas de edad gestacional y peso inferior o igual a 1 700 g, en el período comprendido entre 2006 y 2011, ambos inclusive, en el Hospital General Universitario "Dr. Enrique Cabrera Cossío". Se analizaron como factores de riesgo asociados a la retinopatía del prematuro: la edad gestacional, el peso, el sexo, la apariencia racial, la oxigenoterapia, el método de administración del oxígeno, la sepsis, el distrés respiratorio, la administración de esteroides, las transfusiones de sangre, la apnea y la hemorragia intraventricular. Se utilizó el estadígrafo chi cuadrado para verificar la posible asociación entre las variables y la presencia de retinopatía. RESULTADOS: se incluyeron en el estudio 89 pacientes. Presentó retinopatía el 20,2 % de la muestra, y el 72,2 % de los que desarrollaron retinopatía nació antes de las 32 semanas de gestación; con mayor frecuencia el peso al nacer osciló entre 1 000 y 1 500 g, y predominó el sexo masculino. En los menores de 1 000 g el 66,6 % presentó retinopatía. El 88,2 % de los que desarrollaron retinopatía recibieron ventilación con presión positiva intermitente como método de la oxigenoterapia. Un paciente (5,6 %) no recibió oxígeno y desarrolló retinopatía. Las afecciones que más se presentaron relacionadas con la prematuridad fueron el síndrome de distrés respiratorio y las infecciones. CONCLUSIONES: los factores de riesgo asociados fueron la edad gestacional, la utilización de oxígeno, el número de días con oxigenoterapia, el método de administración de este y la presencia de 2 afecciones perinatales (distrés respiratorio e infecciones).

INTRODUCTION: after a preterm delivery, a number of factors may cause first detention and then abnormal growth of the retinal vessels and give rise to retinopathy of prematurity. OBJECTIVE: to characterize the clinical and epidemiological pattern of the retinopathy of prematurity in newborns aged less than 35 weeks of gestation and birthweight equal or under 1 700 g. METHODS: retrospective, observational, descriptive and cross-sectional study of newborns with less than 35 weeks of gestational age and weighing 1 700g or less in the period of 2006 through 2011, including both years, at "Dr Enrique Cabrera Cossio" general university hospital. Risk factors associated to retinopathy of prematurity were analyzed such as gestational age, weight, sex, racial appearance, oxygen therapy, method of oxygen administration, sepsis, respiratory distress, steroid administration, blood transfusions, short of breath and intraventricle hemorrhage. Chi square statistic was used to verify the possible association between the variables and the presence of retinopathy. RESULTS: eighty nine patients were included in the study. Retinopathy affected 20.2 % of the sample and 72.2 % of those who developed retinopaty were born before 32 weeks of gestation; their birthweight frequently ranged from 1 000 to 1 500 g and boys predominated. In those neonates weighing less than 1 000 g, 66.6 % presented with retinopathy. In the group of neonates that developed retinopathy, 88.2 % were ventilated with intermittent positive pressure as method of oxygen therapy. One patient (5.6 %) did not receive oxygen and suffered retinopathy. The most frequent prematurity-related conditions were respiratory syndrome distress and infections. CONCLUSIONS: the risk factors were gestational age, oxygen supply, number of days with oxygen therapy, oxygen administration method and the existence of two perinatal conditions such as respiratory distress and infections.

Increasing NAD synthesis in muscle via nicotinamide phosphoribosyltransferase is not sufficient to promote oxidative metabolism.

The NAD biosynthetic precursors nicotinamide mononucleotide and nicotinamide riboside are reported to confer resistance to metabolic defects induced by high fat feeding in part by promoting oxidative metabolism in skeletal muscle. Similar effects are obtained by germ line deletion of major NAD-consuming enzymes, suggesting that the bioavailability of NAD is limiting for maximal oxidative capacity. However, because of their systemic nature, the degree to which these interventions exert cell- or tissue-autonomous effects is unclear. Here, we report a tissue-specific approach to increase NAD biosynthesis only in muscle by overexpressing nicotinamide phosphoribosyltransferase, the rate-limiting enzyme in the salvage pathway that converts nicotinamide to NAD (mNAMPT mice). These mice display a ∼50% increase in skeletal muscle NAD levels, comparable with the effects of dietary NAD precursors, exercise regimens, or loss of poly(ADP-ribose) polymerases yet surprisingly do not exhibit changes in muscle mitochondrial biogenesis or mitochondrial function and are equally susceptible to the metabolic consequences of high fat feeding. We further report that chronic elevation of muscle NAD in vivo does not perturb the NAD/NADH redox ratio. These studies reveal for the first time the metabolic effects of tissue-specific increases in NAD synthesis and suggest that critical sites of action for supplemental NAD precursors reside outside of the heart and skeletal muscle.

Progressive increase in mtDNA 3243A>G heteroplasmy causes abrupt transcriptional reprogramming.

Variation in the intracellular percentage of normal and mutant mitochondrial DNAs (mtDNA) (heteroplasmy) can be associated with phenotypic heterogeneity in mtDNA diseases. Individuals that inherit the common disease-causing mtDNA tRNA(Leu(UUR)) 3243A>G mutation and harbor ∼10-30% 3243G mutant mtDNAs manifest diabetes and occasionally autism; individuals with ∼50-90% mutant mtDNAs manifest encephalomyopathies; and individuals with ∼90-100% mutant mtDNAs face perinatal lethality. To determine the basis of these abrupt phenotypic changes, we generated somatic cell cybrids harboring increasing levels of the 3243G mutant and analyzed the associated cellular phenotypes and nuclear DNA (nDNA) and mtDNA transcriptional profiles by RNA sequencing. Small increases in mutant mtDNAs caused relatively modest defects in oxidative capacity but resulted in sharp transitions in cellular phenotype and gene expression. Cybrids harboring 20-30% 3243G mtDNAs had reduced mtDNA mRNA levels, rounded mitochondria, and small cell size. Cybrids with 50-90% 3243G mtDNAs manifest induction of glycolytic genes, mitochondrial elongation, increased mtDNA mRNA levels, and alterations in expression of signal transduction, epigenomic regulatory, and neurodegenerative disease-associated genes. Finally, cybrids with 100% 3243G experienced reduced mtDNA transcripts, rounded mitochondria, and concomitant changes in nuclear gene expression. Thus, striking phase changes occurred in nDNA and mtDNA gene expression in response to the modest changes of the mtDNA 3243G mutant levels. Hence, a major factor in the phenotypic variation in heteroplasmic mtDNA mutations is the limited number of states that the nucleus can acquire in response to progressive changes in mitochondrial retrograde signaling.

Eficacia y seguridad de la eritropoyetina en la anemia de la prematuridad / Efficacy and safety of erythropoietin for anemia of prematurity

Introducción: la eritropoyetina alfa recombinante forma parte del tratamiento de la anemia de la prematuridad. En Cuba su uso ha sido limitado y controvertido en cuanto a esquema y dosis empleada. Métodos: ensayo clínico prospectivo, multicéntrico, no aleatorizado, de eficacia y seguridad de eritropoyetina en la disminución de transfusiones en el recién nacido pretérmino de muy bajo peso. Se incluyeron 72 neonatos con edad gestacional menor de 34 semanas posmenstruales, y peso al nacer menor o igual a 1 500 g, con más de 7 días posnatales e ingesta de 50 mL/kg/día. Resultados: todos recibieron eritropoyetina 300 U/kg, subcutánea, 3 veces/semana, hasta las 40 semanas de edad gestacional y suplemento de hierro y vitaminas. La eritropoyetina fue muy segura, solo se notificó con relación posible una retinopatía de la prematuridad, ligera y recuperada. Conclusiones: se transfundieron 7 pacientes (9,7 por ciento) en el curso del estudio. El uso tardío de eritropoyetina en el pretérmino de muy bajo peso confirma su eficacia y seguridad(AU)

Introduction: recombinant alpha erythropoietin is part of the treatment for anemia of prematurity. The use of this one in Cuba has been restricted and controversial as to schedule and dose. Methods: prospective, non-randomized multicenter assay on the safety and efficacy of erythropoietin in the reduction of blood transfusion in very-low-weight preterm newborn. Seventy two neonates with gestational age under 34 post-menstruation weeks, weighing equal or less than 1 500 g, over 7 days of life after birth and fed on 50 mL/kg/day were included in the study. Results: all of them received 300 U/kg erythropoietin by subcutaneous administration three times a week up to reaching 40 weeks of gestational age and an iron and vitamin supplement. Erythropoietin is very safe; it was just possibly related to slight retinopathy of prematurity, but overcome. Conclusions: seven patients were transfused (9.7 percent ) in the course of study. The late use of erythropoietin in very-low-weight preterm child confirms its efficacy and safety(AU)

Eficacia y seguridad de la eritropoyetina en la anemia de la prematuridad / Efficacy and safety of erythropoietin for anemia of prematurity

Introducción: la eritropoyetina alfa recombinante forma parte del tratamiento de la anemia de la prematuridad. En Cuba su uso ha sido limitado y controvertido en cuanto a esquema y dosis empleada.Métodos: ensayo clínico prospectivo, multicéntrico, no aleatorizado, de eficacia y seguridad de eritropoyetina en la disminución de transfusiones en el recién nacido pretérmino de muy bajo peso. Se incluyeron 72 neonatos con edad gestacional menor de 34 semanas posmenstruales, y peso al nacer menor o igual a 1 500 g, con más de 7 días posnatales e ingesta de 50 mL/kg/día.Resultados: todos recibieron eritropoyetina 300 U/kg, subcutánea, 3 veces/semana, hasta las 40 semanas de edad gestacional y suplemento de hierro y vitaminas. La eritropoyetina fue muy segura, solo se notificó con relación posible una retinopatía de la prematuridad, ligera y recuperada.Conclusiones: se transfundieron 7 pacientes (9,7 por ciento) en el curso del estudio. El uso tardío de eritropoyetina en el pretérmino de muy bajo peso confirma su eficacia y seguridad(AU)

Introduction: recombinant alpha erythropoietin is part of the treatment for anemia of prematurity. The use of this one in Cuba has been restricted and controversial as to schedule and dose.Methods: prospective, non-randomized multicenter assay on the safety and efficacy of erythropoietin in the reduction of blood transfusion in very-low-weight preterm newborn. Seventy two neonates with gestational age under 34 post-menstruation weeks, weighing equal or less than 1 500 g, over 7 days of life after birth and fed on 50 mL/kg/day were included in the study.Results: all of them received 300 U/kg erythropoietin by subcutaneous administration three times a week up to reaching 40 weeks of gestational age and an iron and vitamin supplement. Erythropoietin is very safe; it was just possibly related to slight retinopathy of prematurity, but overcome.Conclusions: seven patients were transfused (9.7 percent) in the course of study. The late use of erythropoietin in very-low-weight preterm child confirms its efficacy and safety(AU)

Eficacia y seguridad de la eritropoyetina en la anemia de la prematuridad / Efficacy and safety of erythropoietin for anemia of prematurity

Introducción: la eritropoyetina alfa recombinante forma parte del tratamiento de la anemia de la prematuridad. En Cuba su uso ha sido limitado y controvertido en cuanto a esquema y dosis empleada. Métodos: ensayo clínico prospectivo, multicéntrico, no aleatorizado, de eficacia y seguridad de eritropoyetina en la disminución de transfusiones en el recién nacido pretérmino de muy bajo peso. Se incluyeron 72 neonatos con edad gestacional menor de 34 semanas posmenstruales, y peso al nacer menor o igual a 1 500 g, con más de 7 días posnatales e ingesta de 50 mL/kg/día. Resultados: todos recibieron eritropoyetina 300 U/kg, subcutánea, 3 veces/semana, hasta las 40 semanas de edad gestacional y suplemento de hierro y vitaminas. La eritropoyetina fue muy segura, solo se notificó con relación posible una retinopatía de la prematuridad, ligera y recuperada. Conclusiones: se transfundieron 7 pacientes (9,7 por ciento) en el curso del estudio. El uso tardío de eritropoyetina en el pretérmino de muy bajo peso confirma su eficacia y seguridad

Introduction: recombinant alpha erythropoietin is part of the treatment for anemia of prematurity. The use of this one in Cuba has been restricted and controversial as to schedule and dose. Methods: prospective, non-randomized multicenter assay on the safety and efficacy of erythropoietin in the reduction of blood transfusion in very-low-weight preterm newborn. Seventy two neonates with gestational age under 34 post-menstruation weeks, weighing equal or less than 1 500 g, over 7 days of life after birth and fed on 50 mL/kg/day were included in the study. Results: all of them received 300 U/kg erythropoietin by subcutaneous administration three times a week up to reaching 40 weeks of gestational age and an iron and vitamin supplement. Erythropoietin is very safe; it was just possibly related to slight retinopathy of prematurity, but overcome. Conclusions: seven patients were transfused (9.7 percent ) in the course of study. The late use of erythropoietin in very-low-weight preterm child confirms its efficacy and safety