Publications by authors named "Giovana Dantas"

Rabies is an encephalitis caused by rabies virus, whose transmission occurs upon contact with infected animals' saliva. The diagnosis is usually performed post-mortem through a direct fluorescent antibody test (DFAT). If the DFAT results are negative, they must be confirmed with an isolation test, usually the mouse inoculation test (MIT), which implies the suffering and death of the animals, high costs and most importantly, up to 28 days to confirm a negative result.

View Article and Find Full Text PDF

Background: Circadian theories for major depressive disorder have suggested that the rhythm of the circadian pacemaker is misaligned. Stable phase relationships between internal rhythms, such as temperature and rest/activity, and the external day-night cycle, are considered to be crucial for adapting to life in the external environmental. Therefore, the relationship and possible alterations among (i) light exposure, (ii) activity rhythm, and (iii) temperature rhythm could be important factors in clinical depression.

View Article and Find Full Text PDF

Unlabelled: The objective of the study is to evaluate whether intervening and testing in different rest-activity periods of the day would produce different measurements in animal behavior studies.

Methodology: Thirty-five, 60-day-old male Wistar rats were submitted to an inescapable foot shock (IFS) stress model and behavioral tests (Light-Dark Box test). The animals received intervention and were tested in both light and dark phases, resulting in the following groups: control L (tested in the light), control D (tested in the dark), LL (IFS and tested in the light), LD (IFS in the light and tested in the dark), DL (IFS in the dark and tested in the light), and DD (IFS and tested in the dark).

View Article and Find Full Text PDF

Morningness-eveningness dimension in humans have been indicated to influence social behavior and individual health. The aim of the present study was to investigate the association of the morningness-eveningness dimension with behavioral and health aspects in a sample of undergraduate students. We assessed demographic data; the Pittsburgh Sleep Quality Index was used to evaluate sleep quality; the Morningness/Eveningness Questionnaire to determine morningness-eveningness, and the Self-Reporting Questionnaire to assess minor psychiatric disorders.

View Article and Find Full Text PDF

In public health, mood disorders are among the most important mental impairments. Patients with depressive episodes exhibit daily mood variations, abnormal patterns in sleep-wake behavior, and in the daily rhythms of several endocrine-metabolic parameters. Although the relationship between the sleep/circadian processes and mood disorders is poorly understood, clock-related therapies, such as light therapy, sleep deprivation, and rigid sleep schedules, have been shown to be effective treatments.

View Article and Find Full Text PDF

Objectives: This study established the value of the 6‐sulfatoxymelatonin (aMT6s) urine concentration as a predictor of the therapeutic response to noradrenaline reuptake inhibitors in depressive patients.

Methods: Twenty-two women aged 18-60 years were selected. Depressive symptoms were assessed by using the Hamilton Depression Scale.

View Article and Find Full Text PDF

Neonates, infants and children are often exposed to pain from invasive procedures during intensive care and during the post-operative period. Opioid anesthesia and post-operative opioid analgesia have been used in infants and result in clinical benefits. The objectives of this study were to verify the effect of repeated 5 microg morphine administration (subcutaneous), once a day for 7 days in 8-day-old rats, at P8 until P14.

View Article and Find Full Text PDF

The effect of methylprednisolone on the hydrolysis of adenine nucleotides by rat blood serum enzymes was studied. Adult male Wistar rats were submitted to three different treatments with synthetic steroid methylprednisolone: one dose of 50 mg/kg, i.p.

View Article and Find Full Text PDF
Article Synopsis
  • The study examined how repeated stress affects pain responses in rats, focusing on the nociceptive response measured through the tail-flick test.
  • Wistar rats were subjected to 40 days of restraint stress, resulting in increased pain sensitivity and a significant reduction in opioid receptor density in key brain areas: the frontal cortex, hippocampus, and spinal cord.
  • Findings indicate that the decrease in opioid receptors may mediate the heightened pain responses seen in stressed rats, though other non-opioid factors could also play a role.
View Article and Find Full Text PDF

Different effects upon the nociceptive response have been observed with exposure to acute and chronic stress in rats. In the present study we repeatedly submitted rats to restraint for 40 days, inducing hyperalgesia using the tail-flick test. A new session of acute stress was applied at the end of 40 days period, and the chronically-stressed animals demonstrated analgesia after forced swimming, but not after restraint.

View Article and Find Full Text PDF

We have previously observed that adenosine 5'-diphosphate (ADP) hydrolysis was decreased 25% in spinal cord synaptosomes of chronically stressed male rats, while no changes were observed in ATPase activity. In the present study, we investigated the effect of chronic stress on the hydrolysis of adenine nucleotides in two cerebral structures (frontal cortex and hypothalamus) and in the blood serum of male rats. Adult male Wistar rats were submitted to 1-h restraint stress/day for 45 days (chronic) and were sacrificed 24 h after the last session of stress.

View Article and Find Full Text PDF