The alteration of neuronal activities of the cuneiform nucleus in non-hypovolemic and hypovolemic hypotensive conditions / Alterações da atividade neuronal no núcleo cuneiforme em condições hipovolêmicas e não hipovolêmicas

Abstract Background: The cuneiform nucleus is located in the center of the circuit that mediates autonomic responses to stress. Hemorrhagic hypotension leads to chemoreceptor anoxia, which consequently results in the reduction of baroreceptor discharge and stimulation of the chemoreceptor. Objective: Using the single-unit recording technique, the neuronal activities of the cuneiform nucleus were investigated in hypotensive states induced by hemorrhage and administration of an anti-hypertensive drug (hydralazine). Methods: Thirty male rats were divided into the control, hemorrhage, and hydralazine groups. The femoral artery was cannulated for the recording of cardiovascular responses, including systolic blood pressure, mean arterial pressure, and heart rate. Hydralazine was administered via tail vein. The single-unit recording was performed from the cuneiform nucleus. Results: The maximal systolic blood pressure and the mean arterial pressure significantly decreased and heart rate significantly increased after the application of hydralazine as well as the following hemorrhage compared to the control group. Hypotension significantly increased the firing rate of the cuneiform nucleus in both the hemorrhage and hydralazine groups compared to the control group. Conclusions: The present data indicate that the cuneiform nucleus activities following hypotension may play a crucial role in blood vessels and vasomotor tone.

RESUMO Antecedentes: O núcleo cuneiforme está localizado no centro do circuito que media as respostas autonômicas ao estresse. A hipotensão hemorrágica leva à anóxia dos quimiorreceptores, que, consequentemente, resulta na redução da descarga dos barorreceptores e estimulação do quimiorreceptor. Objetivo: Utilizando a técnica de registro em unidade única, as atividades neuronais do núcleo cuneiforme foram investigadas em estados de hipotensão induzida por hemorragia e administração de um anti-hipertensivo (hidralazina). Métodos: Trinta ratos machos foram divididos nos grupos controle, hemorragia e hidralazina. A artéria femoral foi canulada, para o registro de respostas cardiovasculares, incluindo pressão arterial sistólica, pressão arterial média e frequência cardíaca. A hidralazina foi administrada na veia da cauda. O registro de unidade única foi realizado a partir do núcleo cuneiforme. Resultados: A pressão arterial sistólica máxima e a pressão arterial média diminuíram significativamente, e a frequência cardíaca aumentou significativamente após a aplicação de hidralazina, bem como a hemorragia seguinte, em comparação com o grupo controle. A hipotensão aumentou significativamente a taxa de disparo da população do núcleo cuneiforme em ambos os grupos de hemorragia e hidralazina, em comparação com o grupo de controle. Conclusões: Os presentes dados indicam que as atividades do núcleo cuneiforme após hipotensão podem desempenhar um papel crucial nos vasos sanguíneos e no tônus vasomotor.

Myocardial infarction following a bee sting: A case report of Kounis syndrome.

In this case report study a 41-year-old man envenomed by a bee sting and diagnosed as Kounis syndrome secondary to hymenoptera envenomation. The patient developed a typical course of myocardial infarction, but the electrocardiogram changes were reversed to almost normal limits. He had a nonsignificant mild lesion in the proximal port of right coronary artery in coronary angiography. The case recovered and discharged after 6 days hospitalization. The clinical implications and pathophysiology of this dangerous association are discussed.

The Condition of Health Safety of Environment in Schools of Rural Area in North- West of Iran.

Aim: we aimed to benchmark standards against prevailing situation of health environment and safety among sampled rural schools in Iran. Methods: This study is a descriptive study conducted in 62 primary schools in rural area of Ardebil (Namin) in Iran. Sampling was done by census and data was collected using standard questionnaire by direct interview. Data was analyzed by Excel and SPSS20 software using ANOVA testing. Findings: The P value for boys school (P=0.15), girls school (P=0.65) and mixed schools (P=044) indicated in case of gender there are no significant differences between health safety and environment of schools in this area. The ergonomic information released that the highest standards are associated with altitude of rooms, black board, light and temperature. Although ergonomic chair (9%), voices (37%) and air condition (29%) showed lower conformity in compare to standards. Conclusion; Some standards perfectly applied in schools which are observed in this study. Although awareness and implementation of recommended HSE standards, schools neglecting and overlooking these standards had lower HSE ratings. It is necessary that schools with lower HSE ratings are made aware of the guidelines and necessary infrastructures allocated to improve their HSE ratings.

Students' Perceptions of the Educational Environment in a Northern Iran University of Medical Science.

Aim: This study aimed to evaluate the current situation of clinical departments in order to explore the viewpoint of interns and trainee according to the Dundee ready educational pattern (DREEM) in Mazandaran University of Medical Science. Design and Setting: the samples included all intern and externs of medical department who were studying in Mazandaran University of Medical Science. Methods and Materials: This was a cross sectional study which comprised students who selected by convenience methods. The standard questionnaire used to assess the view of students who were intern or trainer in Mazandaran University of Medical science during 2012. The questionnaire comprised four subscales i.e. learning (12 item), educational environment (12 item), teachers (11 item) and perceived ability (12). Statistical analysis: SPSS software was used to analysis the collected data. We employed ANOVA, Pierson and Structural Equation Modelbing. Results: the findings showed the mean is above 3 and significance level is belowe0.05 which implies the view of interns is average toward teacher efficacy, educational environment, learning condition and perceived self-ability. Conclusions: according to the findings, authors suggests to future researchers to explore the clinical departments situations in different cultures and regions with different medical educational related factors in order to provide better knowledge regarding gaps in health care systems.