In mammals, efferent projections to the cochlear receptor are constituted by olivocochlear (OC) fibers that originate in the superior olivary complex. Medial and lateral OC neurons make synapses with outer hair cells and with auditory nerve fibers, respectively. In addition to the OC system, there are also descending projections from the auditory cortex that are directed towards the thalamus, inferior colliculus, cochlear nucleus, and superior olivary complex. Olivocochlear function can be assessed by measuring a brainstem reflex mediated by auditory nerve fibers, cochlear nucleus neurons, and OC fibers. Although it is known that the OC reflex is activated by contralateral acoustic stimulation and produces a suppression of cochlear responses, the influence of cortical descending pathways in the OC reflex is largely unknown. Here, we used auditory cortex electrical microstimulation in chinchillas to study a possible cortical modulation of cochlear and auditory nerve responses to tones in the absence and presence of contralateral noise. We found that cortical microstimulation produces two different peripheral modulations: (i) changes in cochlear sensitivity evidenced by amplitude modulation of cochlear microphonics and auditory nerve compound action potentials and (ii) enhancement or suppression of the OC reflex strength as measured by auditory nerve responses, which depended on the intersubject variability of the OC reflex. Moreover, both corticofugal effects were not correlated, suggesting the presence of two functionally different efferent pathways. These results demonstrate that auditory cortex electrical microstimulation independently modulates the OC reflex strength and cochlear sensitivity.

Purpose The aim of this study was to assess the efficacy and safety of Dentoxol mouthrinse in reducing the severity of oral mucositis (OM) secondary to radiation therapy (RT) for head and neck cancer. Methods A randomized, double-blind, placebo-controlled, multicenter phase II clinical trial was conducted. Subjects were asked to use Dentoxol (n = 55) or control (n = 53) mouthrinse 5 times/day during RT. Twice a week, OM was assessed clinically using the WHO scale and the Oral Mucositis Daily Questionnaire (OMDQ) was completed. Results The incidence of severe OM was 40.7% in the Dentoxol group and 51% in the control group (p = 0.265). Comparing all recorded clinical assessments, severe OM was seen in 13.3% of all assessments in the Dentoxol group vs. 21.8% in the control group (p = 0.000). There was a statistically significant lower proportion of assessments showing severe OM in the Dentoxol group at weeks 4, 5, and 6 of RT. The mean duration of severe OM was 11.95 days in the Dentoxol group vs. 14.59 days in the control group (p = 0.502). There was no difference between groups in mouth pain and its impact on function. The use of Dentoxol was safe and was not linked to any serious adverse events. Conclusion The use of Dentoxol 5 times/day is safe and resulted in significantly fewer time-points with severe OM and a delay in the onset of severe OM, compared with a control rinse. A phase III clinical trial is warranted to confirm efficacy and address the limitations of this study.

In this model, exogenous administration of aminoguanidine induces beneficial hemodynamic effects 4 h after the septic challenge. In normal animals, however, aminoguanidine was associated with hypoglycemia, acidosis, hyperlactatemia, and intestinal mucosal ischemia.

A finalidade de esta pesquisa foi compreender e estudar as crenças do professorado em formação inicial sobre o gênero e a ciência, e sua relação com as interações na sala de aula. Para alcançar este objetivo se realizou um estudo de casos com dois estudantes de pedagogia em Ciências Biológicas que realizavam seu estágio profissional no último ano de sua formação. Os dados recolhidos derivaram da realização de uma entrevista semiestruturada, a observação direta da interação na sala de aula e uma entrevista através da técnica de lembrança estimulada. A analise descritivo e interpretativo permitiu identificar crenças associadas à perspectiva neutral e amistosa (SINNES, 2006); também foi encontrado que ainda persistem visões tradicionais da atividade cientifica.

Background: The Chilean Ministry of Health developed a healthy lifestyles intervention directed to adults with overweight and cardiovascular risk factors, called "Program on Healthy Eating and Physical Activity" (PASAF (Rev Med Chile 2014; 142: 817-825)