Regional differential effects of the novel histamine H3 receptor antagonist 6-[(3-cyclobutyl-2,3,4,5-tetrahydro-1H-3-benzazepin-7-yl)oxy]-Nmethyl-3-pyridinecarboxamide hydrochloride (GSK189254) on histamine release in the central nervous system of freely

ABSTRACT After oral administration, the nonimidazole histamine H 3 receptor antagonist, 6-[(3-cyclobutyl-2,3,4,5-tetrahydro-1H-3-benzazepin-7-yl)oxy]-N-methyl-3-pyridinecarboxamide hydrochloride (GSK189254), increased histamine release from the tuberomammillary nucleus, where all histaminergic somata are localized, and from where their axons project to the entire brain. To further understand functional histaminergic circuitry in the brain, dual-probe microdialysis was used to pharmacologically block H 3 receptors in the tuberomammillary nucleus, and monitor histamine release in projection areas. Perfusion of the tuberomammillary nucleus with GSK189254 increased histamine release from the tuberomammillary nucleus, nucleus basalis magnocellularis, and cortex, but not from the striatum or nucleus accumbens. Cortical acetylcholine (ACh) release was also increased, but striatal dopamine release was not affected. When administered locally, GSK189254 increased histamine release from the nucleus basalis magnocellularis, but not from the striatum. Thus, defined by their sensitivity to GSK189254, histaminergic neurons establish distinct pathways according to their terminal projections, and can differentially modulate neurotransmitter release in a brain region-specific manner. Consistent with its effects on cortical ACh release, systemic administration of GSK189254 antagonized the amnesic effects of scopolamine in the rat object recognition test, a cognition paradigm with important cortical components. The discovery of the histamine H 3 receptor (H 3 R) back in 1983 was a major scientific breakthrough that provided key new perspectives in histamine researc

Frequency of positive oral food challenges and their outcomes in the allergy unit of a tertiary-care pediatric hospital.

Introduction and objective: The oral food challenge (OFC) is the gold standard to diagnose food allergy (FA); however, it is not a procedure free from the risk of having significant allergic reactions, even life-threatening.The aims of our study were to evaluate the frequency of positive OFCs performed in chil-dren with a suspected diagnosis of IgE- and non-IgE–mediated (food protein–induced enterocolitis syndrome (FPIES)) FA and how the failed challenges were managed.Materials and methods: A retrospective chart review was done on all children who have had OFCs in a tertiary-care pediatric allergy unit from 2017 to 2019.Results: 682 patients were enrolled and 2206 challenges were performed: 2058 (93%) for IgE-mediated FA and 148 (7%) for FPIES. There were 262 (11.8%) challenge failures. The transfer to the emergency department was required 3 times (1.1%). None of the failed challenges resulted in death or hospitalization and 13.3% challenges did not require any treatment.Conclusions: Our findings confirm that food challenges can be performed safely in a specialized setting by well-trained personnel; all food challenge reactions, even the most serious, were reversible, thanks to a prompt recognition and treatment that generally did not worsen over time

A quantitative headspace-solid-phase microextraction-gas chromatography-flame ionization detector method to analyze short chain free fatty acids in rat feces

This study sought to develop and validate a quantitative method to analyze short chain free fatty acids (SCFAs) in rat feces by solid-phase microextraction and gas chromatography (SPME-GC) using the salt mixture ammonium sulfate and sodium dihydrogen phosphate as salting out agent. Conditioning and extraction time, linearity, limits of detection and quantification, repeatability, and recovery were evaluated. The proposed method allows quantification with improved sensitivity as compared with other methods exploiting SPME-GC. The method has been applied to analyze rat fecal samples, quantifying acetic, propionic, isobutyric, butyric, isopentanoic, pentanoic, and hexanoic acids

SiO2-TBD as New Heterogeneous Catalyst for the Nef Conversion of ­Secondary Nitroalkanes under Neat Conditions

Treatment of secondary nitroalkanes with neat silica-supported 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), at room temperature, allows the direct conversion of the secondary nitro groups to the corresponding keto carbonyls

Cardiovascular Organ Damage in Clinical Subtypes of Systemic Sclerosis: Arterial Stiffness and Echocardiography Might Not Be the Ideal Tools for Patient Risk Stratification

Background. Vascular damage is recognized as a diagnostic landmark in systemic sclerosis (SSc), both in its limited and diffuse subtypes. Early detection at a subclinical stage with transthoracic echocardiography (TTE) and carotid femoral pulse wave velocity (cfPWV) may be helpful in therapeutic planning and management. Aim of the Study. The aim of the study was to evaluate presence of subclinical cardiovascular damage in patients with limited and diffuse SSc in comparison with a cohort of healthy individuals. Methods. Consecutive patients with limited and diffuse SSc underwent complete TTE and cfPWV and a complete review of clinical data. As controls, 23 healthy subjects with similar hemodynamic profiles were selected. Results. 41 patients (35 female, aged 56.9 years), 21 with diffuse and 20 with limited SSc, were recruited. Past medical history, cardiovascular risk factors, gender distribution, and disease duration were similar in the two groups as well as TTE parameters and hemodynamic indexes—cfPWV (6.5 [6–6.8] vs. 7.0 [6.2–8.5], p=0.24) and augmentation index (145.6 ± 14.2 vs. 149 ± 20.6, p=0.52). Patients with limited SSc were 10 years older than patients with diffuse SSc. In the multiple regression analysis, only age (p=0.0154) and disease duration (p=0.0467) resulted as the significant determinant of cfPWV. When compared to healthy controls, no significant difference emerged in TTE or hemodynamic indexes. Conclusion. In SSc, cfPWV increases with age, with no additional impact of pathology or subtype. Vascular damage in the SSc population is not accurately reflected in increased arterial stiffness, as evaluated with cfPWV, or classically defined echocardiographic findings of organ damage (i.e., left ventricular concentric remodelling and increased filling pressures)