Effects of Rhodiola rosea L. extract on behavioural and physiological alterations induced by chronic mild stress in female rats.

Rhodiola rosea L. is one of the most popular adaptogen and an antistress plant in European and Asiatic traditional medicine. Our previous studies have confirmed the adaptogenic and antistress properties of a single administration of R. rosea L. extract in rats exposed to acute stress. There is increasing evidence that prolonged exposure to stressful life events and depression are both related to significant behavioural, endocrinological and neurobiological changes in human and animal subjects. The aim of this study was to determine whether chronic treatment with a hydroalcoholic R. rosea extract (RHO) standardized in 3% rosavin and 1% salidroside can prevent alterations induced in female rats following 6 weeks of a chronic mild stress (CMS) procedure. This was analysed through the behavioural and physiological parameters of consumption of 1% sucrose solution, locomotor and exploratory activities, body weight gain and oestrous cycle length. After the first 3 weeks of stress, RHO was administered daily by gavage at doses of 10, 15 and 20 mg/kg for the remaining 3 weeks. In addition, the antidepressant drug fluoxetine (10 mg/kg os), which has been shown to reverse CMS-induced disruptions, was used as the reference treatment. Rats subjected to the CMS procedure demonstrated decreased sucrose intake, reduced moving behaviour, minimized weight gain and dysregulation of their oestrous cycle. Treatment with RHO completely reverted all of these changes. The effects of RHO were comparable to those of fluoxetine. Interestingly, neither RHO nor fluoxetine influence the behavioural and physiological parameters tested in non-stressed animals. These findings strongly showed that chronic administration of RHO results in potent inhibition of the behavioural and physiological changes induced by chronic exposure to mild stressors.

Uso ético da biodiversidade brasileira: necessidade e oportunidade / Ethical use of the brazilian biodiversity: necessity and opportunity

A situação em que o Brasil e outros países em desenvolvimento se encontram hoje, de meros compradores de tecnologias importadas ou pagadores de royalties para laboratórios farmacêuticos estrangeiros, torna o processo de ampliação do sistema de saúde vigente muito oneroso ou, muitas vezes, não atende a suas necessidades específicas. O renovado interesse mundial, observado nos últimos anos, por produtos derivados da biodiversidade, tais como fitoterápicos, fitofármacos, cosméticos e suplementos alimentares, vêm estimulando investimentos de países industrializados em bioprospecção. Estas constatações devem estimular o debate, sobretudo no seio de países em desenvolvimento e detentores de rica biodiversidade e de conhecimentos tradicionais, como é o caso do Brasil, sobre a necessidade da instituição de modelos de saúdes nacionais, pautados em suas aptidões e carências, e sobre as oportunidades econômicas que o uso ético da biodiversidade apresenta.

Nowadays, Brazil and other developing countries are simple pharmaceutical technologies buyers or are only paying royalties to foreign laboratories. These facts make the public health system raise very expensive or can't put up attend to the specific necessities of these countries. The renewed global interest for natural products, such as phytotherapics, phytomedicines, cosmetics and nutraceuticals, has been stimulating industrialized countries investment in bioprospection. These evidences should stimulate the arguments, specially in developing countries, rich in natural resources and traditional knowledge, like Brazil, on the necessity of national health politics, based on their need and capacity, and on the economical opportunities that the ethical use of the biodiversity presents.

Catch-up growth in children with chronic renal failure treated with long-term enteral nutrition.

Growth retardation commonly complicates chronic renal failure in children. Although the etiology of this growth impairment is multifactorial, inadequate nutrition is considered an important cause in infants and young children. An "aggressive" nutritional approach has been repeatedly suggested in children with early onset chronic renal failure and poor feeding habits, but the possibility of inducing catch-up growth by energy supplementation is still controversial. The nutritional effects of a long-term, home-based enteral feeding program were studied in two infants and three children with moderate to severe chronic renal failure and impaired growth associated with persistent anorexia. In all patients, renal failure had developed during the first year of life due to congenital diseases. Enteral feeding was performed at home, during the night, through a silicone rubber nasogastric tube. The treatment lasted for 1 year. The energy intake ranged between 101% and 116% of the recommended dietary allowance (RDA), and the protein intake between 96% and 113% of the RDA in all patients but one, in whom proteins were restricted to 75% of the RDA. All children showed a substantial improvement in deviation score for both weight (mean increase +1.76), height (mean increase +1.52) and in the general metabolic condition, irrespective of age, severity of osteodystrophy, or degree of renal failure. The treatment was well tolerated and, apart from a few episodes of vomiting, no complications arose during the treatment. Tube feeding may be an effective therapeutic option for overcoming malnutrition when chronic renal failure is associated with persistent anorexia. In infants and young children, growth retardation can be opposed and catch-up growth obtained.

Parainfluenza (Sendai) virus infects ciliated cells and secretory cells but not basal cells of rat tracheal epithelium.

Sendai virus is a common respiratory pathogen in rodents. In the airways of rats infected with Sendai virus, viral antigen is present in epithelial cells, but whether all types of epithelial cells are infected is unknown. Because each type of epithelial cell has specific functions that could be affected by viral infection, we asked whether ciliated cells, secretory cells, and basal cells of the rat tracheal epithelium become infected by Sendai virus. We inoculated pathogen-free rats intranasally with Sendai virus, killed the rats 1 to 12 days after inoculation, and prepared the tracheas for double-labeling immunohistochemistry and for electron microscopy. In other studies, we maximized the infection by inoculating rats with a 100-fold higher titer of the virus, by inoculating weanling rats, or by inoculating tracheal explants with Sendai virus in vitro. We also determined whether Sendai virus can infect basal cells of tracheal explants after removal of the overlying columnar epithelial cells. Immunohistochemical studies showed that at the peak of the infection (5 days after inoculation), 30% of the surface epithelial cells stained for Sendai virus antigen, but no basal cells were stained. Electron microscopic examination confirmed the presence of viral particles in ciliated cells and secretory cells, but none were found in basal cells. No basal cells were infected under the conditions that maximized the infection. We conclude that ciliated cells and secretory cells of the rat tracheal epithelium become infected by Sendai virus, but basal cells do not become infected.

Mechanism of the relaxant response of the rat duodenum to bradykinin.

Bradykinin (BK) did not increase cyclic AMP production in cultured rat duodenum smooth muscle cells. Its relaxant effect on the tissue was inhibited by apamin and potentiated by phorbol dibutyrate (PDBU). PDBU also caused a relaxation which was inhibited by apamin. BK's relaxant effect, and its potentiation by PDBU, are due to activation of Ca(2+)-dependent K+ channels.

Growth in young children with chronic renal failure.

Statural growth and its relation to growth potential, renal function, blood urea nitrogen (BUN), mineral metabolism hormones and dietary intake were studied in 17 prepubertal children (aged 1.6-9.3 years) on conservative treatment for chronic renal failure due to tubulo-interstitial nephropathy. Statural growth (height SDS) was related to the degree of renal failure, was more retarded than ossification, and was independent of the chronological age of the patients. We observed that the lower the glomerular filtration rate (GFR), the lower was the growth potential (increased bone age/statural age ratio). Growth velocity may be normal regardless of statural and bone maturation delay and the degree of renal insufficiency. Impaired growth rate correlated with parathyroid hormone levels, caloric intake and increased blood urea nitrogen during the year of observation. These data show that comprehensive monitoring and suitable treatment must be performed in order to prevent growth retardation at any GFR level.

Nitrogen balance: an adequate treatment prescription index for children on haemofiltration.

We studied 12 children (10.6 +/- 2.5 years; 21 +/- 4.8 kg body weight) with end-stage renal disease on chronic haemofiltration prescribed using a urea kinetic model. After 12 months, urea generation rate, protein catabolic rate and nitrogen balance were assessed in each patient. Pre-treatment BUN was adequate in all 12 patients but in three nitrogen balance and growth rate were unsatisfactory. These three children were studied for a second year in which plasma water cleared/week was increased; during this year a significant increase in nitrogen balance and growth rate was obtained.