The first synapses of the afferents of peripheral chemoreceptors are located in the Nucleus Tractus Solitarius (NTS) and there is evidence that short-term sustained hypoxia (SH - 24 h, FiO 0.1) facilitates glutamatergic transmission in NTS neurons of rats. Adenosine is an important neuromodulator of synaptic transmission and hypoxia contributes to increase its extracellular concentration.
View Article and Find Full Text PDFSustained hypoxia (SH) in mice induces changes in the respiratory pattern and increase in the parasympathetic tone to the heart. Among adenosine G-protein-coupled receptors (GPCRs), the A receptors are especially important in mediating adenosine actions during hypoxia due to their expression in neurons involved with the generation and modulation of the autonomic and respiratory functions. Herein, we performed an in vivo evaluation of the baseline cardiovascular and respiratory parameters and their changes in response to SH in knockout mice for A receptors (A KO).
View Article and Find Full Text PDFCurr Res Physiol
September 2022
The autonomic profile of mice submitted to sustained hypoxia (SH) was not yet fully evaluated. Herein, we characterized the cardiovascular and autonomic profile of conscious freely moving mice submitted to SH using two sequential experimental protocols to evaluate the parasympathetic and sympathetic tone to the heart and the sympathetic tone to the vascular resistance. In the first protocol the sequence of antagonists was methyl-atropine followed by propranolol and then by prazosin, while in the second protocol the sequence was propranolol followed by methyl-atropine and then by prazosin.
View Article and Find Full Text PDFNew Findings: What is the central question of this study? Do mice submitted to sustained hypoxia present autonomic and respiratory changes similarly to rats? What is the main finding and its importance? Arterial pressure in the normal range, reduced baseline heart rate and tachypnoea were observed in behaving sustained hypoxia mice. Recordings in the in situ preparation of mice submitted to sustained hypoxia show an increase in cervical vagus nerve activity and a simultaneous reduction in thoracic sympathetic nerve activity correlated with changes in the respiratory cycle. Therefore, mice are an important model for studies on the modulation of sympathetic activity to the cardiovascular system and the vagus innervation of the upper airways due to changes in the respiratory network induced by sustained hypoxia.
View Article and Find Full Text PDFA new model is proposed for the kinetics of the heterogeneous deacetylation of chitin/chitosan. This new model is able to represent the process over much broader ranges than the other kinetic models reported in the literature. The unreacted shrinking core model was modified with the inclusion of increasing diffusional effects as the reaction progresses, causing the rate to slow down and preventing the degree of deacetylation reaching 100 %, even in the presence of excess NaOH.
View Article and Find Full Text PDFJ Invest Dermatol
January 2019
The incidence and patient survival rates of melanoma have increased over the last several decades, with a growing population of patients who develop multiple primary melanomas (MPMs). To determine risk factors for developing MPMs and compare the survival of patients with MPMs to those with single primary melanomas, a prospective, multidisciplinary database of patients with melanoma at a single tertiary care institution was retrospectively reviewed. From 1985 to 2013, 6,963 patients with single primary melanomas and 305 patients with MPMs were identified.
View Article and Find Full Text PDFImportance: Melanoma in situ (MIS) is increasing in incidence, and expert consensus opinion recommends surgical excision for therapeutic management. Currently, wide local excision (WLE) is the standard of care. However, Mohs micrographic surgery (MMS) is now used to treat a growing subset of individuals with MIS.
View Article and Find Full Text PDFTwelve participants ran (9 km · h(-1)) to test two types of running shoes: replica and original shoes. Ground reaction force, plantar pressure and electromyographic activity were recorded. The shoes were tested randomly and on different days.
View Article and Find Full Text PDFThe aim was to investigate the Functional Disability degree in adults with spinal cord injury and its association with socio-demographic characteristics. The Barthel Index was used and 75 subjects answered a questionnaire with socio-demographic variables. The Chi-Square, Cronbach's Alpha and Fisher tests were used in the analysis.
View Article and Find Full Text PDF