Atrial natriuretic peptide modifies arterial blood pressure through nitric oxide pathway in rats

The aim of the present study was to determine the relationship between the hypotensive effect of the atrial natriuretic peptide (ANP) and the nitric oxide (NO) pathway. N(G)-nitro-L-arginine methyl ester bolus (L-NAME, 1 mg/kg) reverted the decrease in mean arterial pressure induced by ANP administration (5 μg/kg bolus and 0.2 μg · kg-1 · min-1 infusion), and the injection of L-NAME before peptide administration suppressed the ANP hypotensive response. To confirm these findings, a histochemical reaction was used to determine NADPH-diaphorase activity (a NO synthase marker) in the endothelium and smooth muscle of aorta and arterioles of the small and large intestine. ANP increased aorta and arteriole endothelium staining after both in vivo administration and in vitro tissue incubation. In both cases, L-NAME prevented the ANP effect on NADPH-diaphorase activity. Tissues incubated with 8-bromoguanosine 3',5'-cyclic monophosphate mimicked ANP action. In addition, ANP administration increased urinary excretion of NO(x) end products. These findings indicate that ANP increases NO synthesis capability and NO production and suggest that the cGMP pathway may be involved. In conclusion, the NO pathway could be an intercellular messenger in the ANP endothelium- dependent vasorelaxation mechanism.Fil: Costa, Maria de Los Angeles. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Ciencias Biológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: González Bosc, Laura Veronica. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Ciencias Biológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Majowicz, Mónica Patricia. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Ciencias Biológicas; ArgentinaFil: Vidal, Norberto Armando. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Ciencias Biológicas; ArgentinaFil: Balaszezuk, Ana M.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Ciencias Biológicas; ArgentinaFil: Arranz, Cristina Teresa. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Ciencias Biológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Atrial Natriuretic Peptide Modifies Arterial Blood Pressure Through Nitric Oxide Pathway in Rats

The aim of the present study was to determine the relationship between the hypotensive effect of the atrial natriuretic peptide (ANP) and the nitric oxide (NO) pathway. N(G)-nitro-L-arginine methyl ester bolus (L-NAME, 1 mg/kg) reverted the decrease in mean arterial pressure induced by ANP administration (5 μg/kg bolus and 0.2 μg · kg-1 · min-1 infusion), and the injection of L-NAME before peptide administration suppressed the ANP hypotensive response. To confirm these findings, a histochemical reaction was used to determine NADPH-diaphorase activity (a NO synthase marker) in the endothelium and smooth muscle of aorta and arterioles of the small and large intestine. ANP increased aorta and arteriole endothelium staining after both in vivo administration and in vitro tissue incubation. In both cases, L-NAME prevented the ANP effect on NADPH-diaphorase activity. Tissues incubated with 8-bromoguanosine 3',5'-cyclic monophosphate mimicked ANP action. In addition, ANP administration increased urinary excretion of NO(x) end products. These findings indicate that ANP increases NO synthesis capability and NO production and suggest that the cGMP pathway may be involved. In conclusion, the NO pathway could be an intercellular messenger in the ANP endothelium- dependent vasorelaxation mechanism.Fil: Costa, Maria de Los Angeles. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Ciencias Biológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: González Bosc, Laura Veronica. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Ciencias Biológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Majowicz, Mónica Patricia. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Ciencias Biológicas; ArgentinaFil: Vidal, Norberto Armando. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Ciencias Biológicas; ArgentinaFil: Balaszezuk, Ana M.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Ciencias Biológicas; ArgentinaFil: Arranz, Cristina Teresa. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Ciencias Biológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Characterisation of microbial attack on archaeological bone

As part of an EU funded project to investigate the factors influencing bone preservation in the archaeological record, more than 250 bones from 41 archaeological sites in five countries spanning four climatic regions were studied for diagenetic alteration. Sites were selected to cover a range of environmental conditions and archaeological contexts. Microscopic and physical (mercury intrusion porosimetry) analyses of these bones revealed that the majority (68%) had suffered microbial attack. Furthermore, significant differences were found between animal and human bone in both the state of preservation and the type of microbial attack present. These differences in preservation might result from differences in early taphonomy of the bones. © 2003 Elsevier Science Ltd. All rights reserved

Evolution over Time of Ventilatory Management and Outcome of Patients with Neurologic Disease∗

OBJECTIVES: To describe the changes in ventilator management over time in patients with neurologic disease at ICU admission and to estimate factors associated with 28-day hospital mortality. DESIGN: Secondary analysis of three prospective, observational, multicenter studies. SETTING: Cohort studies conducted in 2004, 2010, and 2016. PATIENTS: Adult patients who received mechanical ventilation for more than 12 hours. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Among the 20,929 patients enrolled, we included 4,152 (20%) mechanically ventilated patients due to different neurologic diseases. Hemorrhagic stroke and brain trauma were the most common pathologies associated with the need for mechanical ventilation. Although volume-cycled ventilation remained the preferred ventilation mode, there was a significant (p < 0.001) increment in the use of pressure support ventilation. The proportion of patients receiving a protective lung ventilation strategy was increased over time: 47% in 2004, 63% in 2010, and 65% in 2016 (p < 0.001), as well as the duration of protective ventilation strategies: 406 days per 1,000 mechanical ventilation days in 2004, 523 days per 1,000 mechanical ventilation days in 2010, and 585 days per 1,000 mechanical ventilation days in 2016 (p < 0.001). There were no differences in the length of stay in the ICU, mortality in the ICU, and mortality in hospital from 2004 to 2016. Independent risk factors for 28-day mortality were age greater than 75 years, Simplified Acute Physiology Score II greater than 50, the occurrence of organ dysfunction within first 48 hours after brain injury, and specific neurologic diseases such as hemorrhagic stroke, ischemic stroke, and brain trauma. CONCLUSIONS: More lung-protective ventilatory strategies have been implemented over years in neurologic patients with no effect on pulmonary complications or on survival. We found several prognostic factors on mortality such as advanced age, the severity of the disease, organ dysfunctions, and the etiology of neurologic disease