Mercuric chloride toxicity in rat liver mitochondria and isolated hepatocytes

The effects of mercuric chloride on isolated rat liver mitochondria and freshly isolated rat hepatocytes were investigated. Mercuric chloride (in the μM range) depresses state 3 respiration, suggesting a strong effect at the level of the phosphorylation system. It also stimulates state 4 respiration and decreases mitochondrial membrane potential, suggesting an uncoupling action. In isolated hepatocytes, mercuric chloride causes a dose- and time-dependent cell death, accompanied by depletion of intracellular glutathione. Furthermore, mercuric chloride decreases intracellular ATP and ADP levels simultaneously with increasing AMP concentration, indicating fast hydrolysis of ATP without adequate rephosphorylation. From this study we can conclude that the bioenergetic lesion promoted by mercuric chloride seems to be sufficient to explain lethal hepatocyte injury.     

The practice of teaching: a dialogue with professors of nursing

The aim of this study is discuss the daily practice of the nursing professors at the Federal University of Piauí. The study was accomplished in a qualitative approach with methodological emphasis on Oral History with the primary subjects being professors of nursing at the Federal University of Piauí. The instrumento for data collection was semi-structured interviews and data analysis was realized through content analysis. The nursing educators are considering the possibility of breaking with the vertical teaching method in order to stimulate the power of creativity and understanding within the student body which finds itself in a permanent state of transformation.     

Cortical seeding of a craniopharyngioma after craniotomy: Case report

BACKGROUND: Cortical seeding of a craniopharyngioma has been rarely reported. We present a case that ectopically recurred along the tract of a previous surgical route. METHODS: A 27-year-old woman presented earlier with a suprasellar craniopharyngioma. A left frontotemporal craniotomy was done with subtotal resection of the tumor because it was strongly adhered to the optic chiasm. Histopathology confirmed the diagnosis of craniopharyngioma. Six months after, the patient presented with decreased visual acuity and diplopia. She was reoperated through the previous craniotomy with a total resection. One year after the second surgery, the patient presented with seizures that were difficult to control. Magnetic resonance imaging revealed a contrast-enhancing tumor with cystic and solid components on the left temporal lobe cortex. The primary tumor bed was intact. The patient was reoperated, and the temporal lobe tumor was totally removed. Histologic studies showed an adamantinomatous craniopharyngioma. The patient was free of neurologic abnormalities, and no new lesion was found in the magnetic resonance imaging performed 1 year after the last surgery. CONCLUSIONS: Although craniopharyngiomas exhibit a benign histopathologic pattern, a total resection combined with careful inspection and irrigation of the surgical field is the optimal treatment for preventing local and ectopic recurrences. It is strongly recommended that the concerned patients have a long-term clinical and neuroimaging follow-up.     

NGF and NT-3 exert differential effects on the expression of neuropeptides in the suprachiasmatic nucleus of rats withdrawn from ethanol treatment

Some neurotrophins have the capability of enhancing neuropeptide expression in several regions of the brain. It was also recently shown that NGF, infused over 1 month, offsets the decreased synthesis and expression of vasopressin (VP) and vasoactive intestinal polypeptide (VIP) in the suprachiasmatic nucleus (SCN) of rats submitted to chronic ethanol treatment and withdrawal. In the present study we examined the effectiveness of neutrotrophin-3 (NT-3) in promoting such effects, given that SCN neurons express both the high and the low affinity receptors for this neurotrophin. NT-3 was intraventricularly infused during 10 days to rats withdrawn from prolonged ethanol treatment. The total number, and the mean somatic volume, of VP- and VIP-immunoreactive neurons was compared with the estimates obtained from control rats and withdrawn rats treated with either NGF or cerebrospinal fluid during the same period. The infusion of cerebrospinal fluid and of NT-3 did not prevent the reduction in the number of peptide-producing neurons induced by withdrawal from ethanol treatment. Conversely, NGF infusion increased their number to control levels and led to neuronal hypertrophy. Our results show that, unlike NGF, NT-3 does not display the capacity of enhancing neuropeptide expression in the SCN. Because SCN neurons express the low affinity p75(NTR), which is equally activated by both neurotrophins, our results additionally indicate that the effects of NGF upon SCN neurons are not receptor-mediated. Taken together, our data suggest that indirect mechanisms, rather than direct neutrophin signaling, are likely to mediate the trophic effects exerted by NGF upon SCN neurons.     

Health education: teaching about American tegumentary leishmaniasis

Knowledge on the circulation of American tegumentary leishmaniasis (ATL) and perception by the local population are highly relevant for developing a control program, since they mobilize the community for effective health measures. This work aimed to orient primary school teachers and pupils (grades 1 through 4) in the public school system in Maricá, Rio de Janeiro State, Brazil, on ATL, using talks, posters, and leaflets with an interactive approach. Talks were given in seven municipal schools, and activities were held with 1,314 pupils and 56 teachers. Leaflets were distributed to the pupils with activities to help consolidate the content. Two months later one school was chosen for post-evaluation. Of the 213 pupils who had attended the talk, 198 answered a questionnaire, of whom 178 (89.9%) could remember the disease and 125 (63.1%) provided correct answers on transmission. Thus, informed children and teachers can function as information disseminators in health within their community and are therefore capable of contributing to control of endemic diseases.