O ultra-som terapêutico de 1 MHz, na dose de 0,5 W cm-2, sobre o tecido ósseo de cães avaliado por densitometria óptica em imagens radiográficas

As lesões tendíneas nas extremidades distais dos membros estão entre as mais freqüentes alterações do aparelho locomotor na rotina clínico-cirúrgica humana e animal e, não raro, necessitam de terapias adjuvantes para seu completo retorno às funções fisiológicas. O ultra-som terapêutico (UST) é a modalidade mais utilizada nas clínicas de reabilitação para tratar lesões tendíneas, mas devido à falta ou a divergências de estudos específicos sobre seus efeitos no tecido ósseo, sua utilização sobre as regiões distais dos membros, ricas em protuberâncias ósseas e áreas desprovidas de cobertura muscular, sempre preocuparam os profissionais da área médica. No intuito de esclarecer os efeitos do UST sobre o tecido ósseo, seis cães receberam tratamento ultra-sônico contínuo, de 1MHz, durante cinco minutos diários, por um período de 20 dias sobre a região craniodistal do rádio e da ulna. A intensidade do UST aplicada foi de 0,5W cm-2 no membro torácico direito, ficando o membro contralateral como controle. A região distal de ambos os membros torácicos foi radiografada para análise de densitometria óssea em imagens radiográficas, antes do início da terapia e ao final do tratamento. Não houve alterações significativas de densidade mineral óssea entre os membros tratados e os controles. Conclui-se que dentro dos parâmetros utilizados no experimento a utilização do UST em regiões ósseas protuberantes ou desprovidas de cobertura muscular pode ser feita com segurança.

Efeito do lítio sobre a hiperatividade locomotora induzida pela lesão eletrolítica da região do núcleo mediano da rafe em ratos

A lesão do núcleo mediano da rafe (NMR) produz sintomas que sugerem validade de face ao episódio maníaco. Esta pesquisa avaliou o efeito do lítio sobre a hiperatividade locomotora induzida por esta lesão. Vinte e um ratos Wistar machos foram submetidos à lesão eletrolítica da região do NMR (LR) e 17 foram submetidos à lesão fictícia (LF). Após recuperação, a atividade locomotora foi avaliada na caixa de atividade (Med Associates/ENV-515). Parte dos animais destes grupos recebeu tratamentos com lítio (47,5 mg/kg/2x dia i.p.) por 10 dias, enquanto o restante foi tratado com salina no mesmo esquema. A reavaliação ao final dos tratamentos demonstrou que o lítio reduziu significantemente a atividade locomotora em relação à avaliação inicial no grupo LR (ANOVA/Bonferroni p < 0,05), tornando-a equivalente aos baixos níveis dos grupos LF. Estes dados sustentam a hipótese de que as manifestações induzidas pela lesão do NMR podem constituir um modelo animal de mania.

Propriedades mecânicas de três fios de sutura no reparo do tendão do músculo flexor profundo do dedo de cães

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Use of the elevated T-maze to study anxiety in mice

We have recently suggested that the elevated T-maze (ETM) is not a useful test to study different types of anxiety in mice if a procedure similar to that originally validated for rats is employed. The present study investigated whether procedural (five exposures in the enclosed arm instead of three as originally described for rats) and structural (transparent walls instead of opaque walls) changes to the ETM leads to consistent inhibitory avoidance acquisition (IAA) and low escape latencies in mice. Results showed that five exposures to the ETM provoked consistent IAA, an effect that was independent of the ETM used. However, the ETM with transparent walls (ETMt) seemed to be more suitable for the study of conditioned anxiety (i.e. IAA) and unconditioned fear (escape) in mice, since IAA (low baseline latency with a gradual increase over subsequent exposures) and escape (low latency) profiles rendered it sensitive to the effects of anxiolytic and anxiogenic drugs. In addition to evaluation of drug effects on IAA and escape, the number of line crossings in the apparatus were used to control for locomotor changes. Results showed that whereas diazepam (1.0-2.0 mg/kg) and flumazenil (10-30 mg/kg) impaired IAA, FG 7142 (10-30 mg/kg) did not provoke any behavioral change. Significantly, none of these benzodiazepine (BDZ) receptor ligands modified escape latencies. The 5-HT1A partial receptor agonist buspirone (1.0-2.0 mg/kg) and the 5-HT releaser fenfluramine (0.15-0.30 mg/kg) impaired IAA and facilitated escape, while the full 5-HT1A receptor agonist, 8-OH-DPAT (0.05-0.1 mg/kg) and the 5-HT2B/2C receptor antagonist, SER 082 (0.5-2.0 mg/kg) failed to modify either response. mCPP (0.5-2.0 mg/kg), a 5-HT2B/2C receptor agonist, facilitated IAA but did not alter escape latency. Neither antidepressant utilized in the current study, imipramine (1.0-5.0 mg/kg) and moclobemide (3.0-10 mg/kg) affected IAA or escape performance in mice. The well-known anxiogenic drugs yohimbine (2.0-8.0 mg/kg) and caffeine (10-30 mg/kg) did not selectively affect IAA, although caffeine did impair escape latencies. Present results suggest the ETMt is useful for the study of conditioned anxiety in mice. However, upon proximal threats (e.g. open arm exposure), mice do not exhibit escape behavior as an immediate defensive strategy, suggesting that latency to leave open arm is not a useful parameter to evaluate unconditioned fear in this species. (C) 2003 Elsevier B.V. All rights reserved.

Developmental lead exposure: behavioral alterations in the short and long term

Wistar dams were exposed to 500 ppm of Pb, as Ph acetate, or 660 ppm Na acetate in drinking water during pregnancy and lactation. Male pups at 23 (weaned) or 70 days (adult) of age were submitted to behavioral evaluation and Pb determination. The behaviors evaluated were: locomotor activity (open-field test), motor coordination (rotarod test), exploratory behavior (holeboard test), anxiety (elevated plus maze and social interaction tests), and learning and memory (shuttle box). Ph levels were measured in the blood and cerebral regions (hippocampus and striatum) of dams and pups. The results of the present report demonstrated that exposure to Ph during pregnancy and lactation induces in weaned pups hyperactivity, decreased exploratory behavior, and impairment of learning and memory. These alterations were observed at blood Ph levels in the range that may be attained in children chronically exposed to low levels of Pb (21 +/- 3 mug/dl). Regarding adults, the results demonstrated that the regimen of exposure adopted induces anxiety in these animals at nondetectable blood Ph levels. (C) 2001 Elsevier B.V. All rights reserved.

Effects of diethylpropion treatment and withdrawal on aorta reactivity, endothelial factors and rat behavior

Diethylpropion (DEP) is an amphetamine-like compound used as a coadjutant in the treatment of obesity and which presents toxicological importance as a drug of abuse. This drug causes important behavioral and cardiovascular complications; however, the vascular and behavioral alterations during DEP treatment and withdrawal, have not been determined. We evaluated the effects of DEP treatment and withdrawal on the rat aorta reactivity to noradrenaline, focusing on the endothelium, and the rat behavior during DEP treatment and withdrawal. DEP treatment caused a hyporreactivity to noradrenaline in aorta, reversible after 2 days of withdrawal and abolished by both the endothelium removal and the presence of L-NAME, but not by the presence of indomethacin. Furthermore, DEP treatment increased the general activity of rats. Contrarily, DEP withdrawal caused a decrease in the locomotor activity and an increase in grooming behavior, on the 2nd and 7th days after the interruption of the treatment, respectively. DEP treatment also caused an adaptive vascular response to noradrenaline that seems to be dependent on the increase in the endothelial nitric oxide system activity, but independent of prostaglandins synthesis. The data evidenced chronological differences in the adaptive responses of the vascular and central nervous systems induced by DEP treatment. Finally, a reversion of the adaptive response to DEP was observed in the vascular system during withdrawal, whereas a neuroadaptive process was still present in the central nervous system post-DEP. These findings advance on the understanding of the vascular and behavioral pathophysiological processes involved in the therapeutic and abusive uses of DEP. (C) 2003 Elsevier B.V. (USA). All rights reserved.

Caracterização morfológica dos estádios de desenvolvimento do aparelho reprodutor masculino da rã-touro, Rana catesbeiana, no sistema anfigranja de criação intensiva

The objective of this work was to caracterize the morphological characterization of the development stages of male reproduction apparel of bullfrog Rana catesbeiana from intensive Anfigranja system. During the period of one year, 657 bullfrog males were removed from regrowing and reproduction sections in Anfigranja system to study basic aspects of the reproduction of this specie. The collections were realized monthly and, in that occasion, the body and testicles weights for each animal were recorded and their macroscopic gonadal characteristics, registred. Testicles from 274 males were removed and histologically analyzed. From the macro and microscopic gonadal characteristics, analysis set of the testicles, five stages of gonadal maturation for the male of Rana catesbeiana were determined: juvenile, beginning of maturation, intermediate maturation, advanced maturation and spent.

An examination of constraints affecting the intralimb coordination of hemiparetic gait

A dynamical systems approach to the study of locomotor intralimb coordination in those with hemiparesis led to an examination of the utility of the shank-thigh relative phase (RP) as a collective variable and the identification of potential constraints that may shape this coordination. Eighteen non-disabled individuals formed three groups matched to the age and gender of six participants with chronic right hemiparesis. The three groups differed in the constraints imposed on their walking: (1) walking at their preferred walking speed; (2) walking as slowly as those with hemiparesis; and, (3) walking slowly with a right ankle-foot orthosis (AFO). The results revealed an asymmetry in intralimb coordination between the unaffected and affected leg of those with hemiparesis localized to the latter third of the gait cycle when the limb is advanced from the end of stance to the reestablishment of a new stance. Walking slowly with or without an AFO resulted in no measureable effect in the non-disabled, but accounts for 22% of the variance in the intralimb coordination of the hemiplegic's affected limb and 16% in the unaffected limb. The AFO offered little additional contribution. These results derive from shank-thigh RP that is shown to provide more information about intralimb coordination than knee angle displacement. Implications for these results and the use of RP for rehabilitation are discussed. (C) 2000 Elsevier B.V. B.V. All rights reserved. PsycINFO classification. 3297. 2330.

Developmental lead exposure in rats: is a behavioral sequel extended at F2 generation?

Lead toxicity was studied in rats exposed from conception until weaning and assessed by monitoring offspring behavior in both the open field and elevated plus maze and by determining tissue lead in an assessment schedule extended to first (F1) and second (F2) generations. Dams utilized for the F1 generation were submitted to 750 ppm of lead (acetate) in drinking water during pregnancy and lactation. For F1 pups, behavioral alterations were not detected in the elevated plus maze, while in the open field, spontaneous locomotor activity as well as time of both grooming and rearing increased, while freezing time decreased in 30- and 90-day-old rats. Lead content was higher in tissues of 1- and 30-day-old pups. However, in 90-day-old rats, lead was detected only in the femur. F2 generation was lead-free but still presented alterations in both locomotor activity and grooming in 30- and 90-day-old pups. It appears that developmental lead exposure may cause behavioral effects during the developmental stage of the F1 generation, which remains throughout the animal's adult life as a sequel, regardless of lead accumulation, and is extended to the F2 generation of rats. (C) 2001 Elsevier B.V. All rights reserved.

Caracterização morfológica dos estádios de desenvolvimento do aparelho reprodutor feminino da rã-touro, Rana catesbeiana, no sistema anfigranja de criação intensiva

The objective of this work was to caracterize the morphological characterization of the development stages of female reproduction apparel of bullfrog Rana catesbeiana from intensive Anfigranja system. During the period of one year, 836 bullfrog females were removed from regrowing and reproduction sections of the Anfigranja system to study the basic aspects of the reproduction of this specie. The collections were realized monthly and, in that occasion, the body and ovary weights for each animal were recorded and their macroscopic gonadal characteristics, registred. The ovaries from 303 females were removed and histologically examined. From the macro and microscopic characteristics analysis set of the ovary, five stages of gonadal maturation for the female of Rana catesbeiana were determined: juvenile, beginning of maturation, intermediate maturation, advance maturation and spent.

Regulation of contextual conditioning by the median raphe nucleus

The median raphe nucleus (MRN) has been suggested as the origin of a behavioral inhibition system that projects to the septum and hippocampus. Electrical stimulation of this mesencephalic area causes behavioral and autonomic manifestations characteristic of fear such as, freezing, defecation and micturition. In this study we extend these observations by analyzing the behavioral and autonomic responses of rats with lesions in the MRN submitted to a contextual conditioning paradigm. The animals underwent electrolytic or sham lesions of the median raphe nucleus. One day (acute) or 7 days (chronic) later they were tested in an experimental chamber where they received 10 foot-shocks (0.7 mA, 1 s with 20-s interval). The next day, sham and MRN-lesioned animals were tested again either in the same or in a different experimental chamber. During this, the duration of freezing, rearings, bouts of micturition and number of fecal boli were recorded. Sham-operated rats placed in the same chamber showed more freezing than rats exposed to a different context. This freezing behavior was clearly suppressed in rats with acute or chronic lesions in the MRN. MRN lesions also reduced the bouts of micturition and number of fecal boli. These rats showed a reduced number of rearings than sham-lesioned rats. This effect is probably the result of the displacement effect provoked by freezing since no significant differences in the number of rearings could be observed between these animals and the NMR-lesioned rats tested in an open field. This lesion produced higher horizontal locomotor activity in this test than the controls (sham-lesioned rats). These results point to the importance of the median raphe nucleus in the processing of fear conditioning with freezing being the most salient feature of it. Behavioral inhibition is also under control of MRN but its neural substrate seems to be dissociated from that of contextual fear. (C) 1998 Elsevier B.V. B.V.

Plant derived alkaloid (-)-cassine induces anti-inflammatory and anti-hyperalgesics effects in both acute and chronic inflammatory and neuropathic pain models

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Implication of the 5-HT(2A) and 5-HT(2C) (but not 5HT(1A)) receptors located within the periaqueductal gray in the elevated plus-maze test-retest paradigm in mice

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Contrasting effects of acute and chronic treatment with imipramine and fluoxetine on inhibitory avoidance and escape responses in mice exposed to the elevated T-maze

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Similar anxiolytic-like effects following intra-amygdala infusions of benzodiazepine receptor agonist and antagonist: Evidence for the release of an endogenous benzodiazepine inverse agonist in mice exposed to elevated plus-maze test

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)