Mesenteric Vascular Dysregulation and Intestinal Inflammation Accompanies Experimental Spinal Cord Injury

Cervical and high thoracic spinal cord injury (SCI) drastically impairs autonomic nervous system function. Individuals with SCI at thoracic spinal-level 5 (T5) or higher often present cardiovascular disorders that include resting systemic arterial hypotension. Gastrointestinal (GI) tissues are critically dependent upon adequate blood flow and even brief periods of visceral hypoxia triggers GI dysmotility. The aim of this study was to test the hypothesis that T3-SCI induces visceral hypoperfusion, diminished postprandial vascular reflexes and concomitant visceral inflammation. We measured in vivo systemic arterial blood pressure and superior mesenteric artery (SMA) and duodenal blood flow in anesthetized T3-SCI rats at 3 days and 3 weeks post-injury either fasted or following enteral feeding of a liquid mixed-nutrient meal (Ensure™). In separate cohorts of fasted T3-SCI rats, markers of intestinal inflammation were assayed by qRT-PCR. Our results show that T3-SCI rats displayed significantly reduced SMA blood flow under all experimental conditions (p\u3c0.05). Specifically, the anticipated elevation of SMA blood flow in response to duodenal nutrient infusion (postprandial hyperemia) was either delayed or absent after T3-SCI. The dysregulated SMA blood flow in acutely-injured T3-SCI rats coincides with abnormal intestinal morphology and elevation of inflammatory markers, all of which resolve after 3 weeks. Specifically, Icam1, Ccl2 (MCP-1) and Ccl3 (MIP-1α) were acutely elevated following T3-SCI. Our data suggest that arterial hypotension diminishes mesenteric blood flow necessary to meet mucosal demands at rest and during digestion. The resulting GI ischemia and low-grade inflammation may be an underlying pathology leading to GI dysfunction seen following acute T3-SCI

Tooth Decay in Alcohol Abusers Compared to Alcohol and Drug Abusers

Alcohol and drug abuse are detrimental to general and oral health. Though we know the effects of these harmful habits on oral mucosa, their independent and combined effect on the dental caries experience is unknown and worthy of investigation. We compared 363 “alcohol only” abusers to 300 “alcohol and drug” abusers to test the hypothesis that various components of their dental caries experience are significantly different due to plausible sociobiological explanations. After controlling for the potential confounders, we observe that the “alcohol and drug” group had a 38% higher risk of having decayed teeth compared to the “alcohol only” group (P < .05). As expected, those who belonged to a higher social class (OR = 1.98; 95%  CI = 1.43–2.75) and drank wine (OR = 1.85; 95%  CI = 1.16–2.96) had a higher risk of having more filled teeth. We conclude that the risk of tooth decay among “alcohol only” abusers is significantly lower compared to “alcohol and drug” abusers

Hyaline Arteriolosclerosis in 30 Strains of Aged Inbred Mice.

During a screen for vascular phenotypes in aged laboratory mice, a unique discrete phenotype of hyaline arteriolosclerosis of the intertubular arteries and arterioles of the testes was identified in several inbred strains. Lesions were limited to the testes and did not occur as part of any renal, systemic, or pulmonary arteriopathy or vasculitis phenotype. There was no evidence of systemic or pulmonary hypertension, and lesions did not occur in ovaries of females. Frequency was highest in males of the SM/J (27/30, 90%) and WSB/EiJ (19/26, 73%) strains, aged 383 to 847 days. Lesions were sporadically present in males from several other inbred strains at a much lower (<20%) frequency. The risk of testicular hyaline arteriolosclerosis is at least partially underpinned by a genetic predisposition that is not associated with other vascular lesions (including vasculitis), separating out the etiology of this form and site of arteriolosclerosis from other related conditions that often co-occur in other strains of mice and in humans. Because of their genetic uniformity and controlled dietary and environmental conditions, mice are an excellent model to dissect the pathogenesis of human disease conditions. In this study, a discrete genetically driven phenotype of testicular hyaline arteriolosclerosis in aging mice was identified. These observations open the possibility of identifying the underlying genetic variant(s) associated with the predisposition and therefore allowing future interrogation of the pathogenesis of this condition

Outbreak of Abdominal Distension and Obstipation in a C57BL/6J Experimental Autoimmune Encephalomyelitis Study

Abstract Seventy-four 9-week old female C57BL/6J mice housed in a conventional facility were manipulated to induce experimental autoimmune encephalomyelitis, among which 26 developed clinical signs including lethargy, absence of defecation, and abdominal distension. By gross necropsy examination, there was distension of the cecum and colon with fecal impaction. By histologic examination, there was severe ulcerative and proliferative typhlocolitis. Fecal ELISA confirmed the presence of toxins A and B of Clostridium difficile. Alteration in immune status of the immunocompetent mice, due to stress caused by experimental manipulation or autoimmune disease, may have led to intestinal dysbiosis, followed by opportunistic infections resulting in C. difficile-associated disease. This report brings to light the occurrence of the disease in immunocompetent laboratory mice during experimental manipulations associated with alteration in immune status, and it discusses potential hazards associated with conventional housing within a hospital-associated research institute. Keywords Clostridium difficile, C57BL6/J, mouse, typhlocolitis Seventy-four 9-week-old female C57BL/6J mice, housed in open top cages in a conventional facility accredited by the Association for Assessment and Accreditation of Laboratory Animal Care International, were manipulated to induce experimental autoimmune encephalomyelitis (EAE), an animal model for multiple sclerosis. The induction protocol included administration of 500 ng of pertussis toxin (List Biological Laboratories, Campbell, CA) intraperitoneally on days 0 and 2 and emulsions of 400 mg of MOG 35-55 peptide (myelin oligodendrocyte glycoprotein, Penn State College of Medicine Core Facility) with Freund&apos;s complete adjuvant (Sigma-Aldrich, St. Louis, MO), supplemented with 5 mg/mL of heat-inactivated Mycobacterium tuberculosis (Difco, Kansas City, MO), subcutaneously on days 0 and 7. Intraperitoneal injections of vehicle (phosphate buffered saline), naltrexone (0.1 mg/kg), or [Met 5 ]-enkephalin (10 mg/kg) were administered on a daily basis. Beginning on day 2, mice were observed for behavioral signs of EAE, including loss of tail tonus, gait abnormality, and/or hind limb weakness. Because the study protocol required frequent specialized behavioral testing of the mice within the investigator&apos;s laboratory, mice could not be housed in a barrier-type facility. The mice exhibited clinical signs, including lethargy, hunched posture, shallow breathing, absence of defecation, and abdominal distension, culminating in death or euthanasia beginning at day 8 from the initiation of the induction protocol. Morbidity and mortality were observed in a total of 26 mice from all treatment groups over a 3-week period. Distended loops of bowel were palpable in the caudal abdomen of both live and dead mice. Six moribund mice (mice Nos. 1-6), 2 of which demonstrated behavioral signs of EAE, were euthanized, and at gross necropsy, there was marked distension of the cecum and colon and, to a lesser extent, the distal small intestine, by a large quantity of relatively dry fecal materia

IFN-γ receptor and STAT1 signaling in B cells are central to spontaneous germinal center formation and autoimmunity.

Spontaneously developed germinal centers (GCs [Spt-GCs]) harbor autoreactive B cells that generate somatically mutated and class-switched pathogenic autoantibodies (auto-Abs) to promote autoimmunity. However, the mechanisms that regulate Spt-GC development are not clear. In this study, we report that B cell-intrinsic IFN-γ receptor (IFN-γR) and STAT1 signaling are required for Spt-GC and follicular T helper cell (Tfh cell) development. We further demonstrate that IFN-γR and STAT1 signaling control Spt-GC and Tfh cell formation by driving T-bet expression and IFN-γ production by B cells. Global or B cell-specific IFN-γR deficiency in autoimmune B6.Sle1b mice leads to significantly reduced Spt-GC and Tfh cell responses, resulting in diminished antinuclear Ab reactivity and IgG2c and IgG2b auto-Ab titers compared with B6.Sle1b mice. Additionally, we observed that the proliferation and differentiation of DNA-reactive B cells into a GC B cell phenotype require B cell-intrinsic IFN-γR signaling, suggesting that IFN-γR signaling regulates GC B cell tolerance to nuclear self-antigens. The IFN-γR deficiency, however, does not affect GC, Tfh cell, or Ab responses against T cell-dependent foreign antigens, indicating that IFN-γR signaling regulates autoimmune, but not the foreign antigen-driven, GC and Tfh cell responses. Together, our data define a novel B cell-intrinsic IFN-γR signaling pathway specific to Spt-GC development and autoimmunity. This novel pathway can be targeted for future pharmacological intervention to treat systemic lupus erythematosus

Primary Intestinal and Vertebral Chordomas in Laboratory Zebrafish (Danio rerio)

Chordomas are uncommon neoplasms arising from notochord remnants, most commonly occurring in the axial skeleton. Extraskeletal soft tissue chordomas are rare primary tumors, and primary intestinal chordomas have not been reported. Herein we report 24 cases of spontaneous primary intestinal chordomas in zebrafish, as well as 9 spontaneous vertebral chordomas. Both intestinal and vertebral tumors showed invasive behavior, although more commonly in the latter. In all cases of primary intestinal chordomas, there was no axial or peripheral skeletal or other non-visceral involvement. Although uncommon, intestinal chordomas represent a unique background lesion in aged zebrafish.This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by the American College of Veterinary Pathologists and published by Sage Publications. It can be found at: http://intl-vet.sagepub.com/.Keywords: Zebrafish, Chordomas, Vertebral, Intestina

Imaging microstructure of the barley rhizosphere:particle packing and root hair influences

Soil adjacent to roots has distinct structural and physical properties from bulk soil, affecting water and solute acquisition by plants. Detailed knowledge on how root activity and traits such as root hairs affect the three-dimensional pore structure at a fine scale is scarce and often contradictory. Roots of hairless barley (Hordeum vulgare L. cv Optic) mutant (NRH) and its wildtype (WT) parent were grown in tubes of sieved (&lt;250 μm) sandy loam soil under two different water regimes. The tubes were scanned by synchrotron-based X-ray computed tomography to visualise pore structure at the soil–root interface. Pore volume fraction and pore size distribution were analysed vs distance within 1 mm of the root surface. Less dense packing of particles at the root surface was hypothesised to cause the observed increased pore volume fraction immediately next to the epidermis. The pore size distribution was narrower due to a decreased fraction of larger pores. There were no statistically significant differences in pore structure between genotypes or moisture conditions. A model is proposed that describes the variation in porosity near roots taking into account soil compaction and the surface effect at the root surface.</p

Transcriptome sequencing of the Microarray Quality Control (MAQC) RNA reference samples using next generation sequencing

<p>Abstract</p> <p>Background</p> <p>Transcriptome sequencing using next-generation sequencing platforms will soon be competing with DNA microarray technologies for global gene expression analysis. As a preliminary evaluation of these promising technologies, we performed deep sequencing of cDNA synthesized from the Microarray Quality Control (MAQC) reference RNA samples using Roche's 454 Genome Sequencer FLX.</p> <p>Results</p> <p>We generated more that 3.6 million sequence reads of average length 250 bp for the MAQC A and B samples and introduced a data analysis pipeline for translating cDNA read counts into gene expression levels. Using BLAST, 90% of the reads mapped to the human genome and 64% of the reads mapped to the RefSeq database of well annotated genes with e-values ≤ 10^-20. We measured gene expression levels in the A and B samples by counting the numbers of reads that mapped to individual RefSeq genes in multiple sequencing runs to evaluate the MAQC quality metrics for reproducibility, sensitivity, specificity, and accuracy and compared the results with DNA microarrays and Quantitative RT-PCR (QRTPCR) from the MAQC studies. In addition, 88% of the reads were successfully aligned directly to the human genome using the AceView alignment programs with an average 90% sequence similarity to identify 137,899 unique exon junctions, including 22,193 new exon junctions not yet contained in the RefSeq database.</p> <p>Conclusion</p> <p>Using the MAQC metrics for evaluating the performance of gene expression platforms, the ExpressSeq results for gene expression levels showed excellent reproducibility, sensitivity, and specificity that improved systematically with increasing shotgun sequencing depth, and quantitative accuracy that was comparable to DNA microarrays and QRTPCR. In addition, a careful mapping of the reads to the genome using the AceView alignment programs shed new light on the complexity of the human transcriptome including the discovery of thousands of new splice variants.</p

Rapid development of non-alcoholic steatohepatitis in Psammomys obesus (Israeli sand rat)

Background and Aims: A major impediment to establishing new treatments for non-alcoholic steatohepatitis is the lack of suitable animal models that accurately mimic the biochemical and metabolic characteristics of the disease. The aim of this study was to explore a unique polygenic animal model of metabolic disease as a model of non-alcoholic steatohepatitis by determining the effects of 2% dietary cholesterol supplementation on metabolic and liver endpoints in Psammomys obesus (Israeli sand rat). Methods: P. obesus were provided ad libitum access to either a standard rodent diet (20% kcal/fat) or a standard rodent diet supplemented with 2% cholesterol (w/w) for 4 weeks. Histological sections of liver from animals on both diets were examined for key features of non-alcoholic steatohepatitis. The expression levels of key genes involved in hepatic lipid metabolism were measured by real-time PCR. Results: P. obesus fed a cholesterol-supplemented diet exhibited profound hepatomegaly and steatosis, and higher plasma transaminase levels. Histological analysis identified extensive steatosis, inflammation, hepatocyte injury and fibrosis. Hepatic gene expression profiling revealed decreased expression of genes involved in delivery and uptake of lipids, and fatty acid and triglyceride synthesis, and increased expression of genes involved in very low density lipoprotein cholesterol synthesis, triglyceride and cholesterol export. Conclusions: P. obesus rapidly develop non-alcoholic steatohepatitis when fed a cholesterol-supplemented diet that appears to be histologically and mechanistically similar to patients. © 2014 Spolding et al