Persistent phosphorylation of NKCC1 and WNK1 in the epicenter of the spinal cord following contusion injury

Background contextNKCC1 regulates neuronal homeostasis of chloride ions and mediates GABAergic activities in nociceptive processing. WNK1 is an upstream regulator of NKCC1 and acts via SPAK (STE20/SPS1-related proline/alanine-rich kinase) and oxidative stress-responsive kinase 1. NKCC1 activity has been shown to be important in edema formation and nociception following spinal cord injury (SCI).PurposeTo determine the role of NKCC1 and WNK1 in spinal cord tissues in the acute and chronic phases following contusional SCI.Study designAn experimental study investigating the phosphorylation profile of an important Cl-regulatory protein Na+-K+-Cl? cotransporter 1 (NKCC1) and its regulatory-kinase WNK1 (kinase with-no-lysine).MethodsSprague-Dawley rats underwent a contusive SCI at T9. The epicenter spinal cord tissues were harvested at Days 1, 3, and 7 for acute phase of injury or Days 35 and 42 in the chronic phase of injury. Western blot was used to compare phosphorylated levels of both NKCC1 and WNK1 in injured tissues compared with those of sham.ResultsA sustained increase in phosphorylation of NKCC1 and WNK1 was detected in the lesion epicenter in spinal cord during both acute and chronic phases following SCI.ConclusionsThese results suggest that persistent activation of NKCC1 and WNK1 may play an important role in SCI.     

Factors Predicting the Oculomotor Nerve Palsy following Surgical Clipping of Distal Vertebrobasilar Aneurysms: A Single-Institution Experience

Background The aim of our study was to identify various clinical and radiologic factors that correlate with the oculomotor nerve palsy following clipping of distal vertebrobasilar aneurysms. Methods A total of 48 patients with 51 aneurysms were included in this retrospective study . Patient''s age, gender, size, location, and projection of the aneurysm, preoperative Hunt and Hess (H&H) grade, presence of subarachnoid hemorrhage (SAH), temporary clipping, preoperative third nerve palsy, and Glasgow Outcome Scale were included in the model for analysis. Results A total of 15 patients (31.25%) developed oculomotor nerve palsy following clipping of basilar apex aneurysms. 38 patients (79.2%) presented with SAH and 35 patients (72.9%) had poor H&H grades at presentation. The size of the aneurysm (p = 0.03), preoperative H&H grade (p = 0.04), preoperative oculomotor nerve dysfunction (p = 0.007), and projection of an aneurysm (p = 0.004) had shown a significant correlation with the oculomotor nerve palsy. The size of the aneurysm (p = 0.030, odds ratio: 0.381; 95% confidence interval, 0.175–0.827] was an independent predictor of postoperative nerve dysfunction. Conclusion The size of the aneurysm, clinical grade at presentation, and projection of the aneurysm correlated with the oculomotor nerve dysfunction following clipping. These clinical and radiologic parameters can be used to predict the oculomotor nerve outcome.     

Clinical Correlates of the Anatomical Relationships of the Foramen Ovale: A Radioanatomical Study

Introduction Endonasal endoscopic transpterygoid approaches are commonly used techniques to access the infratemporal fossa and parapharyngeal space. Important endoscopic endonasal landmarks for the poststyloid parapharyngeal space, hence the internal carotid artery, include the mandibular nerve at the level of foramen ovale and the lateral pterygoid plate. This study aims to define the anatomical relationships of the foramen ovale, establishing its distance to other important anatomical landmarks such as the pterygoid process and columella. Methods Distances between the foramen ovale, foramen rotundum, and fixed anatomical landmarks like the columella and pterygoid process were measured using computed tomography (CT) scans and cadaveric dissections of the pterygopalatine and infratemporal fossae. Results The mean distances from the foramen ovale to columella and from the foramen rotundum to columella were found to be 9.15 cm and 7.09 cm, respectively. Analysis of radiologic measurements detected no statistically significant differences between sides or gender. Conclusions The pterygoid plates and V3 are prominent landmarks of the endonasal endoscopic approach to the infratemporal fossa and poststyloid parapharyngeal space. A better understanding of the endoscopic anatomy of the infratemporal fossa and awareness of the approximate distances and geometry among anatomical landmarks facilitates a safe and complete resection of lesions arising or extending to these regions.     

Analysis of changes in hepatic gene expression in a murine model of tolerance to acetaminophen hepatotoxicity (autoprotection)

Pretreatment of mice with a low hepatotoxic dose of acetaminophen (APAP) results in resistance to a subsequent, higher dose of APAP. This mouse model, termed APAP autoprotection was used here to identify differentially expressed genes and cellular pathways that could contribute to this development of resistance to hepatotoxicity. Male C57BL/6J mice were pretreated with APAP (400 mg/kg) and then challenged 48 h later with 600 mg APAP/kg. Livers were obtained 4 or 24 h later and total hepatic RNA was isolated and hybridized to Affymetrix Mouse Genome MU430_2 GeneChip. Statistically significant genes were determined and gene expression changes were also interrogated using the Causal Reasoning Engine (CRE). Extensive literature review narrowed our focus to methionine adenosyl transferase-1 alpha (MAT1A), nuclear factor (erythroid-derived 2)-like 2 (Nrf2), flavin-containing monooxygenase 3 (Fmo3) and galectin-3 (Lgals3). Down-regulation of MAT1A could lead to decreases in S-adenosylmethionine (SAMe), which is known to protect against APAP toxicity. Nrf2 activation is expected to play a role in protective adaptation. Up-regulation of Lgals3, one of the genes supporting the Nrf2 hypothesis, can lead to suppression of apoptosis and reduced mitochondrial dysfunction. Fmo3 induction suggests the involvement of an enzyme not known to metabolize APAP in the development of tolerance to APAP toxicity. Subsequent quantitative RT-PCR and immunochemical analysis confirmed the differential expression of some of these genes in the APAP autoprotection model. In conclusion, our genomics strategy identified cellular pathways that might further explain the molecular basis for APAP autoprotection.     

Anti-Inflammatory Activity of Fruit Fractions in Vitro,Mediated through Toll-Like Receptor 4 and 2 in the Context of Inflammatory Bowel Disease

Pattern recognition receptors such as Toll-Like Receptor 2 (TLR2) and 4 (TLR4) are important in detecting and responding to stress and bacterial stimuli. Defect or damage in the TLR2 and TLR4 pathways can lead to sustained inflammation, characteristic of inflammatory bowel disease (IBD). The goal of this study was to identify fruit fractions that can be tested further to develop them as complementary therapies for IBD. In order to do this, we identified fruit fractions that mediate their anti-inflammatory response through the TLR4 and TLR2 pathway. Human Embryonic Kidney (HEK)-hTLR4 and hTLR2 cells were stimulated with their respective ligands to induce inflammation. These cells were treated with one of the 12 fractionated fruits and the inflammatory effect measured. 10 of the fruits came up as anti-inflammatory in the hTLR4 assay and nine in the hTLR2 assays. Many of the fruit fractions mediated their anti-inflammatory actions either mainly in their hydrophobic fractions (such as elderberry) or hydrophilic fractions (such as red raspberry), or both. The strongest anti-inflammatory effects were seen for feijoa and blackberry. This study shows that fruits can have multiple fractions eliciting anti-inflammatory effects in a pathway specific manner. This suggests that the compounds found in fruits can act together to produce health benefits by way of reducing inflammation. Exploiting this property of fruits can help develop complimentary therapies for inflammatory diseases.     

Alterations in cytochrome P450-derived arachidonic acid metabolism during pressure overload-induced cardiac hypertrophy

Cardiac hypertrophy is a major risk factor for many serious heart diseases. Recent data demonstrated the role of cytochrome P450 (CYP)-derived arachidonic acid (AA) metabolites in cardiovascular pathophysiology. In the current study our aim was to determine the aberrations in CYP-mediated AA metabolism in the heart during cardiac hypertrophy. Pressure overload cardiac hypertrophy was induced in Sprague Dawley rats using the descending aortic constriction procedure. Five weeks post-surgery, the cardiac levels of AA metabolites were determined in hypertrophied and normal hearts. In addition, the formation rate of AA metabolites, as well as, CYP expression in cardiac microsomal fraction was also determined. AA metabolites were measured by liquid chromatography–electrospray ionization-mass spectroscopy, whereas, the expression of CYPs was determined by Western blot analysis. Non-parametric analysis was performed to examine the association between metabolites formation and CYP expressions. Our results showed that 5,6-, 8,9-, 11,12-, and 14,15-epoxyeicosatrienoic acids (EETs), and 5-, 12-, 15-, and 20-hydroxyeicosatetraenoic acids (HETEs) levels were increased, whereas, 19-HETE formation was decreased in hypertrophied hearts. The increase in EETs was linked to CYP2B2. On the other hand, CYP1B1 and CYP2J3 were involved in mid-chain HETE metabolism, whereas, CYP4A2/3 inhibition was involved in the decrease in 19-HETE formation in hypertrophied hearts. In conclusion, CYP1B1 played cardiotoxic role, whereas, CYP2B2, CYP2J3 and CYP4A2/3 played cardioprotective roles during pressure overload-induced cardiac hypertrophy. These CYP can be valid targets for the development of drugs to treat and prevent cardiac hypertrophy and heart failure.     

Infusion-Related Reaction Following Daptomycin Two-Minute Rapid Intravenous Administration

Background:

Erythroderma, or red man’s syndrome, is a common infusion-related reaction following vancomycin administration. Erythroderma following daptomycin rapid infusion has not been documented.

Objective:

To report a case of erythroderma following daptomycin 2-minute intravenous (IV) injection.

Case Report:

A review of published literature suggests that this is the first published case of a flushing (nonallergic) reaction resulting from a 2-minute IV injection of daptomycin that is not present with standard IV infusion. A 69-year-old woman following right knee reconstructive surgery presented with right knee joint swelling, purulent discharge, and fever. Subsequently, she was diagnosed with a presumed postsurgical infection and was initiated on vancomycin therapy. Following removal of the infected hardware, the patient was discharged and continued outpatient vancomycin therapy. The patient’s renal function began to decline and therapy was discontinued. Daptomycin 6 mg/kg every 48 hours was initiated via 2-minute IV push. On the initial dose, approximately 2 hours post IV infusion, the patient began to notice redness and a warm sensation on her face, neck, and upper part of the chest. Diphenhydramine 25 mg provided limited immediate relief, but all symptoms subsided within 3 to 4 hours. The patient received her next dose 48 hours later over a 40-minute IV infusion with no adverse effects. Subsequent infusions continued at the same dose over 30 minutes for 4 weeks with no further adverse effects.

Conclusion:

A 2-minute intravenous injection of daptomycin in this patient yielded a reaction that was not present on rechallenge with standard, extended infusion.Key Words: daptomycin, erythroderma, rapid infusion, red man’s syndrome, Staphylococcus aureusDaptomycin is a bactericidal lipopeptide antibiotic commonly used for drug-resistant gram-positive pathogens.¹ Daptomycin was originally approved by the US Food and Drug Administration (FDA) in September 2003 as a once-daily 30-minute intravenous (IV) infusion. In November 2010, the FDA approved a 2-minute rapid IV injection based on data from 2 consecutive pharmacokinetic and safety evaluation studies.^2,3 Daptomycin pharmacokinetic parameters were comparable with the 2-minute IV administration group when compared to the 30-minute IV infusion at a dose of 6 mg/kg.⁴ Although rapid infusions offer convenience and potential cost-savings opportunities, there is potential increased risk of infusion-related adverse events. Infusion-related events may include local reactions, such as phlebitis, pain, tenderness, or local erythema, and systemic reactions manifesting as either dermatologic and cardiovascular complications or anaphylaxis. These reactions have been documented with several antimicrobial infusions including ciprofloxacin, amphotericin B, vancomycin, and others agents that stimulate histamine release.⁵ Vancomycin has been classically associated with infusion-related erythroderma or red man’s syndrome. Signs and symptoms of a reaction will often initiate within 1 hour from the start of the infusion.^5,6 For this reason, the preferred infusion rate for vancomycin is no more than 10 mg/min.⁷ In reports to date, local infusion site–related reactions following 2-minute rapid infusion of daptomycin were mild and of short duration, with no systemic flushing reported in the peerreviewed literature. We report a case of an infusion-related reaction with significant flushing secondary to daptomycin following 2-minute IV push that was absent on rechallenge with an extended infusion.     

Altered Interhemispheric and Temporal Lobe White Matter Microstructural Organization in Severe Chronic Schizophrenia

Diffusion MRI investigations in schizophrenia provide evidence of abnormal white matter (WM) microstructural organization as indicated by reduced fractional anisotropy (FA) primarily in interhemispheric, left frontal and temporal WM. Using tract-based spatial statistics (TBSS), we examined diffusion parameters in a sample of patients with severe chronic schizophrenia. Diffusion MRI data were acquired on 19 patients with chronic severe schizophrenia and 19 age- and gender-matched healthy controls using a 64 gradient direction sequence, (b=1300 s/mm²) collected on a Siemens 1.5T MRI scanner. Diagnosis of schizophrenia was determined by Diagnostic and Statistical Manual for Mental Disorders 4th Edition (DSM-IV) Structured Clinical Interview for DSM disorder (SCID). Patients were treatment resistance, having failed to respond to at least two antipsychotic medications, and had prolonged periods of moderate to severe positive or negative symptoms. Analysis of diffusion parameters was carried out using TBSS. Individuals with chronic severe schizophrenia had significantly reduced FA with corresponding increased radial diffusivity in the genu, body, and splenium of the corpus callosum, the right posterior limb of the internal capsule, right external capsule, and the right temporal inferior longitudinal fasciculus. There were no voxels of significantly increased FA in patients compared with controls. A decrease in splenium FA was shown to be related to a longer illness duration. We detected widespread abnormal diffusivity properties in the callosal and temporal lobe WM regions in individuals with severe chronic schizophrenia who have not previously been exposed to clozapine. These deficits can be driven by a number of factors that are indistinguishable using in vivo diffusion-weighted imaging, but may be related to reduced axonal number or packing density, abnormal glial cell arrangement or function, and reduced myelin.