Brucella aortitis managed with debridement, extra-anatomical bypass, and long-term antimicrobial therapy.

OBJECTIVES: This report aims to review the management and outcomes of Brucella-associated mycotic aortic aneurysms. METHODS: This is a retrospective chart review at a tertiary-level healthcare system. IRB approval was waived per policy. RESULTS: We describe a case of Brucella aortitis acquired from habitual contact with wild hogs. Clinical presentation included lower back pain and elevated white blood cell count. Diagnosis was confirmed with imaging showing an infrarenal abdominal aortic aneurysm and serology revealing elevated Brucella antibodies titers. The patient was initially managed with endovascular aortic repair and combined oral and intravenous antibiotics therapy. He then underwent explanation and extra-anatomical bypass due to symptomatic periaortic infection and interval development of type I endoleak. The patient was asymptomatic after his final operation at 24 months of follow-up and remained on suppressive oral antibiotic therapy. CONCLUSIONS: An aortic aneurysm secondary to Brucella is a rare entity. A detailed history of long-term exposure to animals may be a clue to obtain serologic testing. Operative debridement and re-establishing of reliable blood flow combined with long-term antibiotic suppression are the mainstay of treatment.

News without the buzz: reading out weak theta rhythms in the hippocampus.

Local field potentials (LFPs) reflect the collective dynamics of neural populations, yet their exact relationship to neural codes remains unknown1. One notable exception is the theta rhythm of the rodent hippocampus, which seems to provide a reference clock to decode the animal's position from spatiotemporal patterns of neuronal spiking2 or LFPs3. But when the animal stops, theta becomes irregular4, potentially indicating the breakdown of temporal coding by neural populations. Here we show that no such breakdown occurs, introducing an artificial neural network that can recover position-tuned rhythmic patterns (pThetas) without relying on the more prominent theta rhythm as a reference clock. pTheta and theta preferentially correlate with place cell and interneuron spiking, respectively. When rats forage in an open field, pTheta is jointly tuned to position and head orientation, a property not seen in individual place cells but expected to emerge from place cell sequences5. Our work demonstrates that weak and intermittent oscillations, as seen in many brain regions and species, can carry behavioral information commensurate with population spike codes.

Protective Arteriovenous Fistula in Traumatic Common Carotid Transection.

Penetrating injuries of the neck involving major vessels are associated with high morbidity and mortality. A traumatic arteriovenous (AV) fistula can provide a protective effect by decompressing the injured arterial structure and prevent massive blood loss and airway compression. We present a novel description of CCA (common carotid artery) transection with associated protective AV fistula. Protective AV fistulae have been uncommonly described, and to our knowledge, this is the first case involving carotid transection with associated protective AV fistula ultimately allowing lifesaving operative repair.

Role of prostaglandin D2 receptors in the pathogenesis of abdominal aortic aneurysm formation.

Prostaglandin D2 (PGD2) released from immune cells or other cell types activates its receptors, D prostanoid receptor (DP)1 and 2 (DP1 and DP2), to promote inflammatory responses in allergic and lung diseases. Prostaglandin-mediated inflammation may also contribute to vascular diseases such as abdominal aortic aneurysm (AAA). However, the role of DP receptors in the pathogenesis of AAA has not been systematically investigated. In the present study, DP1-deficient mice and pharmacological inhibitors of either DP1 or DP2 were tested in two distinct mouse models of AAA formation: angiotensin II (AngII) infusion and calcium chloride (CaCl2) application. DP1-deficient mice [both heterozygous (DP1+/-) and homozygous (DP1-/-)] were protected against CaCl2-induced AAA formation, in conjunction with decreased matrix metallopeptidase (MMP) activity and adventitial inflammatory cell infiltration. In the AngII infusion model, DP1+/- mice, but not DP1-/- mice, exhibited reduced AAA formation. Interestingly, compensatory up-regulation of the DP2 receptor was detected in DP1-/- mice in response to AngII infusion, suggesting a potential role for DP2 receptors in AAA. Treatment with selective antagonists of DP1 (laropiprant) or DP2 (fevipiprant) protected against AAA formation, in conjunction with reduced elastin degradation and aortic inflammatory responses. In conclusion, PGD2 signaling contributes to AAA formation in mice, suggesting that antagonists of DP receptors, which have been extensively tested in allergic and lung diseases, may be promising candidates to ameliorate AAA.

Spatial maps in piriform cortex during olfactory navigation.

Odours are a fundamental part of the sensory environment used by animals to guide behaviours such as foraging and navigation1,2. Primary olfactory (piriform) cortex is thought to be the main cortical region for encoding odour identity3-8. Here, using neural ensemble recordings in freely moving rats performing an odour-cued spatial choice task, we show that posterior piriform cortex neurons carry a robust spatial representation of the environment. Piriform spatial representations have features of a learned cognitive map, being most prominent near odour ports, stable across behavioural contexts and independent of olfactory drive or reward availability. The accuracy of spatial information carried by individual piriform neurons was predicted by the strength of their functional coupling to the hippocampal theta rhythm. Ensembles of piriform neurons concurrently represented odour identity as well as spatial locations of animals, forming an odour-place map. Our results reveal a function for piriform cortex in spatial cognition and suggest that it is well-suited to form odour-place associations and guide olfactory-cued spatial navigation.

Management of Mycotic Thoracic Aortic Aneurysm With Staged Hybrid Approach.

We report a case of mycotic thoracic aortic aneurysm managed by staged hybrid repair. A 30-year-old male patient with polysubstance abuse presented with chest pain and elevated white blood cell count. CTA performed showed a rapidly developing mycotic thoracic aortic pseudoaneurysm. He underwent emergent thoracic endovascular aortic repair followed 24 hours later by surgical debridement of the posterior mediastinum. Cultures grew Methicillin-resistant Staphylococcus aureus and patient was placed on long term antibiotics. The patient was asymptomatic on follow up one year after his final operation with complete exclusion of pseudoaneurysm with no endoleak.

Iatrogenic Inferior Vena Cava Resection Requiring Reconstruction.

This is a report of an iatrogenic inferior vena cava (IVC) segmental resection and reconstruction utilizing bovine pericardium. A 48-year-old female patient presented for a planned right nephrectomy by the urology service secondary to xanthogranulomatous pyelonephritis. This was complicated by inadvertent resection of an 8 cm segment of the infrarenal IVC. Postoperatively, the patient did not tolerate IVC ligation due to severe lower extremity edema. She then underwent reconstruction with a bovine pericardium conduit as an interposition graft. The post-operative course was complicated by pulmonary embolism requiring percutaneous intervention. This report addresses the utility of bovine pericardium for IVC reconstruction in an infected field.

Hypogastric Artery-Colonic Fistula after Coil Embolization of Left Hypogastric Artery Aneurysm.

Coil migration into the colon is an extremely rare complication of aneurysm embolization and only three cases have been reported. Two of these cases were managed with resection of the involved colon and the remaining case was managed with serial imaging. We present a 70-year-old man who developed hematochezia 2 years after coil embolization of a ruptured left hypogastric artery aneurysm. The patient was successfully treated with diverting colostomy and endoscopic closure of the sigmoid colon defect. We present the only case report of the use of advanced endoscopy to treat endovascular coil migration.

Discovery of Potent, Selective, and State-Dependent NaV1.7 Inhibitors with Robust Oral Efficacy in Pain Models: Structure-Activity Relationship and Optimization of Chroman and Indane Aryl Sulfonamides.

Voltage-gated sodium channel NaV1.7 is a genetically validated target for pain. Identification of NaV1.7 inhibitors with all of the desired properties to develop as an oral therapeutic for pain has been a major challenge. Herein, we report systematic structure-activity relationship (SAR) studies carried out to identify novel sulfonamide derivatives as potent, selective, and state-dependent NaV1.7 inhibitors for pain. Scaffold hopping from benzoxazine to chroman and indane bicyclic system followed by thiazole replacement on sulfonamide led to identification of lead molecules with significant improvement in solubility, selectivity over NaV1.5, and CYP2C9 inhibition. The lead molecules 13, 29, 32, 43, and 51 showed a favorable pharmacokinetics (PK) profile across different species and robust efficacy in veratridine and formalin-induced inflammatory pain models in mice. Compound 51 also showed significant effects on the CCI-induced neuropathic pain model. The profile of 51 indicated that it has the potential for further evaluation as a therapeutic for pain.

Niacin protects against abdominal aortic aneurysm formation via GPR109A independent mechanisms: role of NAD+/nicotinamide.

AIMS: Chronic adventitial and medial infiltration of immune cells play an important role in the pathogenesis of abdominal aortic aneurysms (AAAs). Nicotinic acid (niacin) was shown to inhibit atherosclerosis by activating the anti-inflammatory G protein-coupled receptor GPR109A [also known as hydroxycarboxylic acid receptor 2 (HCA2)] expressed on immune cells, blunting immune activation and adventitial inflammatory cell infiltration. Here, we investigated the role of niacin and GPR109A in regulating AAA formation. METHODS AND RESULTS: Mice were supplemented with niacin or nicotinamide, and AAA was induced by angiotensin II (AngII) infusion or calcium chloride (CaCl2) application. Niacin markedly reduced AAA formation in both AngII and CaCl2 models, diminishing adventitial immune cell infiltration, concomitant inflammatory responses, and matrix degradation. Unexpectedly, GPR109A gene deletion did not abrogate the protective effects of niacin against AAA formation, suggesting GPR109A-independent mechanisms. Interestingly, nicotinamide, which does not activate GPR109A, also inhibited AAA formation and phenocopied the effects of niacin. Mechanistically, both niacin and nicotinamide supplementation increased nicotinamide adenine dinucleotide (NAD+) levels and NAD+-dependent Sirt1 activity, which were reduced in AAA tissues. Furthermore, pharmacological inhibition of Sirt1 abrogated the protective effect of nicotinamide against AAA formation. CONCLUSION: Niacin protects against AAA formation independent of GPR109A, most likely by serving as an NAD+ precursor. Supplementation of NAD+ using nicotinamide-related biomolecules may represent an effective and well-tolerated approach to preventing or treating AAA.

Discovery and Characterization of Potent Pan-Genotypic HCV NS5A Inhibitors Containing Novel Tricyclic Central Core Leading to Clinical Candidate.

The identification of a novel class of potent pan-genotypic NS5A inhibitors with good pharmacokinetic profile suitable for potential use in treating HCV infections is disclosed here. The present series of compounds are with less complex tricyclic central core, identified through a systematic SAR study carried out on biphenyl moiety. The SAR outcome has confirmed the requirement of near planar and linear conformation of the molecule to achieve the best pan-genotypic activity. In addition, SAR with substituted imidazoles on improvement of antiviral activity is disclosed. The newly identified compounds 12, 16, 19-21 have shown desirable pharmacokinetic profiles with a favorable uptake of compounds in liver and maintained a significant concentration for up to 8 h in the liver. In addition, compounds 20 and 21 have shown superior pan-genotypic anti-HCV activity compared to ledipasvir and daclatasvir. Additional characterization and preliminary safety assessment resulted in the identification of compound 20 as a potential clinical candidate.