A Hemoglobin-Based Multifunctional Therapeutic: Polynitroxylated Pegylated Hemoglobin

Polynitroxylated pegylated hemoglobin (PNPH) as a multifunctional therapeutic takes advantage of the ability of hemoglobin (Hb) to transport oxygen, the antioxidative stress activities from the redox coupling of nitroxide and heme iron, and the hypercolloid properties of pegylation. The published preclinical data demonstrating that PNPH acts as a neurovascular protective multifunctional therapeutic in an animal model simulating prehospital resuscitation of traumatic brain injury (TBI) with hemorrhagic shock (HS) are reviewed. Preliminary results on the potential utility of PNPH for neurovascular protection in thrombolytic stroke therapy and for correction of vascular dysfunction through transfusion in sickle-cell disease (SCD) are also discussed. We hypothesize that with PNPH, Hb has more than been tamed--it has become a therapeutic and not just a nontoxic extracellular oxygen carrier--and that successful PNPH development as a multifunctional therapeutic that protects the neurovasculature and reduces oxidative stress may represent a paradigm shift in transfusion and critical care medicine, which may meet a number of unmet medical needs resulting from oxidative stress and inadequate blood flow, such as HS, TBI, SCD, and stroke

Polynitroxyl Albumin and Albumin Therapy After Pediatric Asphyxial Cardia Arrest: Effects on Cerebral Blood Flow and Neurologic Outcome

Postresuscitation cerebral blood flow (CBF) disturbances and generation of reactive oxygen species likely contribute to impaired neurologic outcome after pediatric cardiac arrest (CA). Hence, we determined the effects of the antioxidant colloid polynitroxyl albumin (PNA) versus albumin or normal saline (NS) on CBF and neurologic outcome after asphyxial CA in immature rats. We induced asphyxia for 9 minutes in male and female postnatal day 16 to 18 rats randomized to receive PNA, albumin, or NS at resuscitation from CA or sham surgery. Regional CBF was measured serially from 5 to 150 minutes after resuscitation by arterial spin-labeled magnetic resonance imaging. We assessed motor function (beam balance and inclined plane), spatial memory retention (water maze), and hippocampal neuronal survival. Polynitroxyl albumin reduced early hyperemia seen 5 minutes after CA. In contrast, albumin markedly increased and prolonged hyperemia. In the delayed period after resuscitation (90 to 150 minutes), CBF was comparable among groups. Both PNA- and albumin-treated rats performed better in the water maze versus NS after CA. This benefit was observed only in males. Hippocampal neuron survival was similar between injury groups. Treatment of immature rats with PNA or albumin resulted in divergent acute changes in CBF, but both improved spatial memory retention in males after asphyxial CA

Presynaptic partner selection during retinal circuit reassembly varies with timing of neuronal regeneration in vivo

Whether neurons can restore their original connectivity patterns during circuit repair is unclear. Taking advantage of the regenerative capacity of zebrafish retina, we show here the remarkable specificity by which surviving neurons reassemble their connectivity upon regeneration of their major input. H3 horizontal cells (HCs) normally avoid red and green cones, and prefer ultraviolet over blue cones. Upon ablation of the major (ultraviolet) input, H3 HCs do not immediately increase connectivity with other cone types. Instead, H3 dendrites retract and re-extend to contact new ultraviolet cones. But, if regeneration is delayed or absent, blue-cone synaptogenesis increases and ectopic synapses are made with red and green cones. Thus, cues directing synapse specificity can be maintained following input loss, but only within a limited time period. Further, we postulate that signals from the major input that shape the H3 HC's wiring pattern during development persist to restrict miswiring after damage

Adverse drug reactions from psychotropic medicines in the paediatric population: analysis of reports to the Danish Medicines Agency over a decade

<p>Abstract</p> <p>Background</p> <p>The prescribing of psychotropic medicines for the paediatric population is rapidly increasing. In attempts to curb the use of psychotropic medicine in the paediatric population, regulatory authorities have issued various warnings about risks associated with use of these products in childhood. Little evidence has been reported about the adverse drug reactions (ADRs) of these medicines in practice. As spontaneous reports are the main source for information about previously unknown ADRs, we analysed data submitted to a national ADR database. The objective was to characterise ADRs reported for psychotropic medicines in the Danish paediatric population over a decade.</p> <p>Findings</p> <p>All spontaneous ADR reports from 1998 to 2007 for children from birth to 17 years of age were included. The unit of analysis was one ADR. We analysed the distribution of ADRs per year, seriousness, age and gender of the child, suspected medicine and type of reported ADR. A total of 429 ADRs were reported for psychotropic medicines and 56% of these were classified as serious. Almost 20% of psychotropic ADRs were reported for children from birth up to 2 years of age and one half of ADRs were reported in adolescents, especially for antidepressants and psychostimulants. Approximately 60% of ADRs were reported for boys. Forty percent of all ADRs were from the category 'nervous and psychiatric disorders'. All but one ADR reported for children below two years were serious and two of these were fatal. A number of serious ADRs reported in children from birth up to 2 years of age were presumably caused by mothers' use of psychotropic medicines during pregnancy.</p> <p>Conclusion</p> <p>The high number of serious ADRs reported for psychotropic medicines in the paediatric population should be a concern for health care professionals and physicians. Considering the higher number of birth defects being reported greater care has to be given while prescribing these drugs for pregnant women.</p

Polynitroxylated Pegylated Hemoglobin: A Novel Neuroprotective Hemoglobin for Acute Volume-Limited Fluid Resuscitation After Combined Traumatic Brain Injury and Hemorrhagic Hypotension in Mice

Objective: Resuscitation of hemorrhagic hypotension after traumatic brain injury is challenging. A hemoglobin-based oxygen carrier may offer advantages. The novel therapeutic hemoglobin-based oxygen carrier, polynitroxylated pegylated hemoglobin (PNPH), may represent a neuroprotective hemoglobin-based oxygen carrier for traumatic brain injury resuscitation.Hypotheses: 1) PNPH is a unique non-neurotoxic hemoglobin-based oxygen carrier in neuronal culture and is neuroprotective in in vitro neuronal injury models. 2) Resuscitation with PNPH would require less volume to restore mean arterial blood pressure than lactated Ringer\u27s or Hextend and confer neuroprotection in a mouse model of traumatic brain injury plus hemorrhagic hypotension.Design: Prospective randomized, controlled experimental study.Setting: University center.Measurements and Main Results: In rat primary cortical neuron cultures, control bovine hemoglobin was neurotoxic (lactate dehydrogenase release; 3-[4,5-dimethylthiazol-2-yl-]-2,5-diphenyltetrazolium bromide assay) at concentrations from 12.5 to 0.625 [mu]M, whereas polyethylene glycol-conjugated hemoglobin showed intermediate toxicity. PNPH was not neurotoxic (p \u3c .05 vs. bovine hemoglobin and polyethylene glycol hemoglobin; all concentrations). PNPH conferred neuroprotection in in vitro neuronal injury (glutamate/glycine exposure and neuronal stretch), as assessed via lactate dehydrogenase and 3-[4,5-dimethylthiazol-2-yl-]-2,5-diphenyltetrazolium bromide (all p \u3c .05 vs. control). C57BL6 mice received controlled cortical impact followed by hemorrhagic hypotension (2 mL/100 g, mean arterial blood pressure ~35-40 mm Hg) for 90 min. Mice were resuscitated (mean arterial blood pressure \u3e50 mm Hg for 30 min) with lactated Ringer\u27s, Hextend, or PNPH, and then shed blood was reinfused. Mean arterial blood pressures, resuscitation volumes, blood gasses, glucose, and lactate were recorded. Brain sections at 7 days were examined via hematoxylin and eosin and Fluoro-Jade C (identifying dying neurons) staining in CA1 and CA3 hippocampus. Resuscitation with PNPH or Hextend required less volume than lactated Ringer\u27s (both p \u3c .05). PNPH but not Hextend improved mean arterial blood pressure vs. lactated Ringer\u27s (p \u3c .05). Mice resuscitated with PNPH had fewer Fluoro-Jade C positive neurons in CA1 vs. Hextend and lactated Ringer\u27s, and CA3 vs. Hextend (p \u3c .05).Conclusions: PNPH is a novel neuroprotective hemoglobin-based oxygen carrier in vitro and in vivo that may offer unique advantages for traumatic brain injury resuscitation

Methicillin-resistant Staphylococcus aureus in Taiwan

We found a virulent closely related clone (Panton-Valentine leukocidin–positive, SCCmec V:ST59) of methicillin-resistant Staphylococcus aureus in inpatients and outpatients in Taiwan. The isolates were found mostly in wounds but were also detected in blood, ear, respiratory, and other specimens; all were susceptible to ciprofloxacin, gentamicin, and trimethoprim-sulfamethoxazole

What is going on around here? Intolerance of uncertainty predicts threat generalization

Attending to stimuli that share perceptual similarity to learned threats is an adaptive strategy. However, prolonged threat generalization to cues signalling safety is considered a core feature of pathological anxiety. One potential factor that may sustain over-generalization is sensitivity to future threat uncertainty. To assess the extent to which Intolerance of Uncertainty (IU) predicts threat generalization, we recorded skin conductance in 54 healthy participants during an associative learning paradigm, where threat and safety cues varied in perceptual similarity. Lower IU was associated with stronger discrimination between threat and safety cues during acquisition and extinction. Higher IU, however, was associated with generalized responding to threat and safety cues during acquisition, and delayed discrimination between threat and safety cues during extinction. These results were specific to IU, over and above other measures of anxious disposition. These findings highlight: (1) a critical role of uncertainty-based mechanisms in threat generalization, and (2) IU as a potential risk factor for anxiety disorder development

The mechanistic basis of protection by non-neutralizing anti-alphavirus antibodies

Although neutralizing monoclonal antibodies (mAbs) against epitopes within the alphavirus E2 protein can protect against infection, the functional significance of non-neutralizing mAbs is poorly understood. Here, we evaluate the activity of 13 non-neutralizing mAbs against Mayaro virus (MAYV), an emerging arthritogenic alphavirus. These mAbs bind to the MAYV virion and surface of infected cells but fail to neutralize infection in cell culture. Mapping studies identify six mAb binding groups that localize to discrete epitopes within or adjacent to the A domain of the E2 glycoprotein. Remarkably, passive transfer of non-neutralizing mAbs protects against MAYV infection and disease in mice, and their efficacy requires Fc effector functions. Monocytes mediate the protection of non-neutralizing mAbs in vivo, as Fcγ-receptor-expressing myeloid cells facilitate the binding, uptake, and clearance of MAYV without antibody-dependent enhancement of infection. Humoral protection against alphaviruses likely reflects contributions from non-neutralizing antibodies through Fc-dependent mechanisms that accelerate viral clearance

Genetic structure of sigmodontine rodents (Cricetidae) along an altitudinal gradient of the Atlantic Rain Forest in southern Brazil

The population genetic structure of two sympatric species of sigmodontine rodents (Oligoryzomys nigripes and Euryoryzomys russatus) was examined for mitochondrial DNA (mtDNA) sequence haplotypes of the control region. Samples were taken from three localities in the Atlantic Rain Forest in southern Brazil, along an altitudinal gradient with different types of habitat. In both species there was no genetic structure throughout their distribution, although levels of genetic variability and gene flow were high