Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto

About: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto is a based out in . It is known for research contribution in the topics: Population & Catalysis. The organization has 2143 authors who have published 3674 publications receiving 71071 citations. The organization is also known as: FFCLRP & FFCLRP-USP.

GABA and opioid mechanisms of the central amygdala underlie the withdrawal-potentiated startle from acute morphine.

Abstract: Anxiety is an affective symptom common to withdrawal from acute or chronic opiate treatment. Although the potentiation of the acoustic startle reflex has been proposed as an index of increased anxiety, there are variable effects of the opiate withdrawal on the startle reflex in chronic dependence models. On the other hand, withdrawal from acute morphine treatment consistently potentiates the acoustic startle reflex, a response that seems to be mediated by the central nucleus of the amygdala (CeA). However, the underlying neurochemical mechanisms have not been elucidated yet. In the present study, we firstly made a comparison between the effects of the withdrawal from both acute and chronic treatments with morphine on the motor activity and the anxiety-like behavior of rats tested in two experimental models, the acoustic startle reflex and the open-field tests. Our second objective was to investigate the role of GABAergic and opioid mechanisms of the CeA in the modulation of the withdrawal-potentiated startle as a measure of anxiety induced by morphine withdrawal. For the production of chronic dependence, rats received morphine injections (10 mg/kg; s.c.) twice daily during 10 days. Forty-eight hours after the interruption of this treatment, independent groups were probed in the startle reflex and open-field tests. For the acute dependence model, groups of rats were tested in the open field and startle tests under control conditions and under withdrawal from a single injection of morphine (10 mg/kg; s.c.) precipitated by naltrexone injections (0.1 mg/kg; s.c.). The results obtained showed that withdrawal from chronic and acute morphine treatments produced anxiety-like behavior in the open field test, although the anxiogenic-like effects could not be dissociated from the motor effects in the acute dependence model. On the other hand, only the withdrawal from acute morphine treatment significantly potentiated the startle response. Next, we examined the effects of intra-CeA microinjections of muscimol-a GABA(A) receptors agonist-and DAMGO-a mu-opioid receptors agonist-on the potentiated startle induced by acute morphine withdrawal. The results obtained showed that intra-CeA injections of muscimol (1 nmol) and DAMGO (0.5 and 1 nmol) significantly inhibited this response. These findings suggest that the acute dependence model is more suitable to study the aversive effects of morphine withdrawal on the acoustic startle response than the chronic opiate dependence model. Besides, mechanisms mediated by mu- and GABA(A)-receptors in the CeA appear to exert an inhibitory influence on the anxiety-like behavior induced by withdrawal from acute morphine treatment.

Growth under Visible Light Increases Conidia and Mucilage Production and Tolerance to UV‐B Radiation in the Plant Pathogenic Fungus Colletotrichum acutatum

Abstract: Light conditions can influence fungal development. Some spectral wavebands can induce conidial production, whereas others can kill the conidia, reducing the population size and limiting dispersal. The plant pathogenic fungus Colletotrichum acutatum causes anthracnose in several crops. During the asexual stage on the host plant, Colletototrichum produces acervuli with abundant mucilage-embedded conidia. These conidia are responsible for fungal dispersal and host infection. This study examined the effect of visible light during C. acutatum growth on the production of conidia and mucilage and also on the UV tolerance of these conidia. Conidial tolerance to an environmentally realistic UV irradiance was determined both in conidia surrounded by mucilage on sporulating colonies and in conidial suspension. Exposures to visible light during fungal growth increased production of conidia and mucilage as well as conidial tolerance to UV. Colonies exposed to light produced 1.7 times more conidia than colonies grown in continuous darkness. The UV tolerances of conidia produced under light were at least two times higher than conidia produced in the dark. Conidia embedded in the mucilage on sporulating colonies were more tolerant of UV than conidia in suspension that were washed free of mucilage. Conidial tolerance to UV radiation varied among five selected isolates.

Synthesis and characterization of gold/alanine nanocomposites with potential properties for medical application as radiation sensors.

Abstract: Radiation dose assessment is essential for several medical treatments and diagnostic procedures. In this context, nanotechnology has been used in the development of improved radiation sensors, with higher sensitivity as well as smaller sizes and energy dependence. This paper deals with the synthesis and characterization of gold/alanine nanocomposites with varying mass percentage of gold, for application as radiation sensors. Alanine is an excellent stabilizing agent for gold nanoparticles because the size of the nanoparticles does not augment with increasing mass percentage of gold, as evidenced by UV–vis spectroscopy, dynamic light scattering, and transmission electron microscopy. X-ray diffraction patterns suggest that the alanine crystalline orientation undergoes alterations upon the addition of gold nanoparticles. Fourier transform infrared spectroscopy indicates that there is interaction between the gold nanoparticles and the amine group of the alanine molecules, which may be the reason for the enhan...

A new occurrence of Limnoperna fortunei (Dunker 1856) (Bivalvia, Mytilidae) in the State of São Paulo, Brazil.

Abstract: The freshwater mussel Limnoperna fortunei (Dunker 1856) (Bivalvia, Mytilidae) has been found in the Parana river, near Rosana, Sao Paulo. This is the first record of this specie in Sao Paulo State. This population of Limnoperna fortunei seems to be young and in a colonization process.

Haplotype frequencies based on eight polymorphic sites at the 3' untranslated region of the HLA-G gene in individuals from two different geographical regions of Brazil.

Abstract: The Brazilian population represents an admixture of native Amerindians, Portuguese settlers and Africans who were brought as slaves during the colonization period that began in the 16th century and was followed by waves of immigrations of Europeans and Asians in the 20th century. The contribution of these different ethnic groups to the constitution of Brazilian populations from different geographic regions is variable and, in addition to environmental factors, might act by determining different allele profiles among Brazilian populations from different regions. We studied polymorphic sites at the 3' untranslated region of the HLA-G gene in individuals from a Northeastern Brazilian region and compared them to our previously published data about a Southeastern Brazilian region, located at a distance of 2589 km. Our results showed that most polymorphic sites present a similar distribution in both populations, except for the lower frequency of the +3003C allele in the Northeastern population compared to the Southeastern population. Although differences in genotypic distribution were only significant for the +3003 locus (P = 0.0201), the diversity of haplotypes was distinct for each population. These results are important for case-control studies on the association of human leucocyte antigen-G polymorphism with disease and also in terms of the genetic structure of two distinct Brazilian populations.