Retrospective study of thoracolumbar ventral fenestration through intercostal thoracotomy and paracostal laparotomy in the dog

Foram analisados os resultados da fenestração ventral dos discos toracolombares em 29 cães agrupados segundo a raça, sexo, peso, idade, graus de déficits neurológicos, duração dos sinais, discos intervertebrais envolvidos, tempo para recuperação e porcentagem de sucesso. A raça Dachshund representou 55,18% (n = 16), cães sem raça definida, 13,8% (n = 4), Poodle e Basset Hound e Cocker Spaniel Inglês 6,89% cada (n = 6), e Pastor Alemão, Beagle e Pinscher, 3,45% cada (n = 3), sendo 51,72%, machos e 48,28%, fêmeas, com idade média de 68,03 meses. O grau de déficits neurológicos correspondeu a: 13,8% dos cães pertencentes ao GI (dor), 41,8% ao GII (paresia), 27,6% ao GIII (paraplegia com dor profunda presente) e 17,2% ao GIV (paraplegia com dor profunda ausente). Os sinais clínicos variaram em duração entre 2 e 60 dias, correspondendo às médias de 18,5 (GI), 12,3 (GII), 8,28 (GIII) e 4,2 dias (GIV). A porcentagem de discos intervertebrais acometidos foi: T10/11 (10,81%), T11/12 (24,33%), T12/13 (40,55%), T13/L1 (16,21%) e L1/2, L2/3 e L3/4, 2,7% cada. O tempo médio de recuperação, em dias, foi: 16 (GI), 19,1 (GII), 20,6 (GIII) e 30,6 (GIV), onde 100% dos animais dos grupos I, II e III recuperaram ambas as funções neurológicas e motoras. O grupo IV apresentou 80% de sucesso. Conclui-se que a fenestração ventral produz excelentes resultados pós-operatórios desde que bem selecionados os casos.

Role of midbrain in the control of breathing in anuran amphibians

The present study was designed to explore systematically the midbrain of unanesthetized, decerebrate anuran amphibians (bullfrogs), using chemical and electrical stimulation and midbrain transections to identify sites capable of exciting and inhibiting breathing. Ventilation was measured as fictive motor output from the mandibular branch of the trigeminal nerve and the laryngeal branch of the vagus nerve. The results of our transection studies suggest that, under resting conditions, the net effect of inputs from sites within the rostral half of the midbrain is to increase fictive breathing frequency, whereas inputs from sites within the caudal half of the midbrain have no net effect on fictive breathing frequency but appear to act on the medullary central rhythm generator to produce episodic breathing. The results of our stimulation experiments indicate that the principal sites in the midbrain that are capable of exciting or inhibiting the fictive frequency of lung ventilation, and potentially clustering breaths into episodes, appear to be those primarily involved in visual and auditory integration, motor functions, and attentional state.

Involvement of the midbrain periaqueductal gray 5-HT1A receptors in social conflict induced analgesia in mice

Recent results from our laboratory have shown that 30-bites social conflict in mice produces a high-intensity, short-term analgesia which is attenuated by systemically injected 5-HT1A receptor agonists, such as BAY R 1531 (6-methoxy-4-(di-n-propylamino)-1,3,4,5-tetrahydrobenz(c,d)indole hydrochloride) and gepirone. The present study investigated the effects of these drugs, as well as the 5-HT1A receptor antagonist WAY 100135 (N-tert-butyl-3-(4-(2-methoxyphenyl)piperazine-1-yl)-2-phenylpropanamide) injected into the midbrain periaqueductal gray matter of mice on 30-bites analgesia. Four to five days after guide-cannula implantation, each mouse received microinjection of gepirone (30 nmol/0.2 mu l), BAY R 1531 (10 nmol/0.2 mu l), WAY 100135 (10 nmol/0.2 mu l), saline (0.9% NaCl) or vehicle (saline + 4% Tween 80) 5 min before either an aggressive (30 bites) or a non-aggressive interaction. Nociception was assessed by the tail-flick test made before as well as 1, 5, 10 and 20 min after social interaction. The full 5-HT1A receptor agonist BAY R 1531 blocked, whereas, WAY 100135 and gepirone intensified 30-bites analgesia, Neither non-aggressive interaction, per se, nor the three compounds given after this type of social interaction significantly changed nociception. These results indicate that 5-HT1A receptors in the periaqueductal gray inhibit analgesia induced by social conflict in mice. (C) 1998 Elsevier B.V. B.V.

Anxiogenic-like effects of mCPP microinfusions into the amygdala (but not dorsal or ventral hippocampus) in mice exposed to elevated plus-maze

Serotonin (5-HT) can either increase or decrease anxiety-like behaviour in animals, actions that depend upon neuroanatomical site of action and 5-HT receptor subtype. Although systemic studies with 5-HT(2) receptor agonists and antagonists suggest a facilitatory role for this receptor subtype in anxiety, somewhat inconsistent results have been obtained when such compounds have been directly applied to limbic targets such as the hippocampus and amygdala. The present study investigated the effects of the 5-HT(2B/2C) receptor agonist mCPP bilaterally microinjected into the dorsal hippocampus (DH: 0, 0.3 1.0 or 3.0 nmol/0.2 mu l), the ventral hippocampus (VH: 0, 0.3, 1.0 or 3.0 nmol/0.2 mu l) or the amygdaloid complex (0, 0.15, 0.5, 1.0 or 3.0 nmol/0.1 mu l) in mice exposed to the elevated plus-maze (EPM). Test sessions were videotaped and subsequently scored for conventional indices of anxiety (percentage of open arm entries and percentage of open arm time) and locomotor activity (closed arm entries). Results showed that mCPP microinfusions into the DH or VH failed to affect any behavioural measure in the EPM. However, when injected into the amygdaloid complex, the dose of 1.0 nmol of this 5HT(2B/2C) receptor agonist increased behavioural indices of anxiety without significantly altering general activity levels. This anxiogenic-like effect of mCPP was selectively and completely blocked by local injection of a behaviourally-inactive dose of SDZ SER-082 (10 nmol/0.1 mu l), a preferential 5-HT(2C) receptor antagonist. These data suggest that 5HT(2C) receptors located within the amygdaloid complex (but not the dorsal or ventral hippocampus) play a facilitatory role in plus-maze anxiety in mice. (c) 2007 Elsevier B.V. All rights reserved.

Anxiolytic-like effect of way-100635 microinfusions into the median (but not dorsal) raphe nucleus in mice exposed to the plus-maze: influence of prior test experience

Studies in several laboratories have confirmed the anxiolytic potential of a wide range of 5-HT1A receptor antagonists in rats and mice, with recent evidence pointing to a postsynaptic site of action in the ventral hippocampus. It would, therefore, be predicted that blockade of 5-HT1A somatodendritic autoreceptors in the midbrain raphe nuclei should produce anxiogenic-like effects. To test this hypothesis, we investigated the effects of WAY-100635 microinfusions (0, 1.0 or 3.0 mug in 0.1 mul) into the dorsal (DRN) or median (MRN) raphe nuclei on behaviours displayed by male Swiss-Webster mice in the elevated plus-maze. As this test is sensitive to prior experience. The effects of intra-raphe infusions were examined both in maze-naive and maze-experienced subjects. Sessions, were videotaped and subsequently scored for conventional indices of anxiety (open arm avoidance) and locomotor activity (closed arm entries), as well as a range of ethological measures (e.g. risk assessment). In maze-naive mice, intra-MRN (but not intra-DRN) infusions of WAY-100635 (3.0 mug) increased open arm exploration and reduced risk assessment. Importantly, these effects could not be attributed to a general reduction in locomotor activity. A similar, though somewhat weaker, pattern of behavioural change was observed in maze-experienced animals. This unexpected anxiolytic effect of 5-HT1A autoreceptor blockade in the MRN cannot be accounted fur by a disinhibition of 5-HT release in forebrain targets (e.g. hippocampus and amygdala), where stimulation of postsynaptic 5-HT1A receptors enhances anxiety-like responses. However, as the MRN also projects to the periaqueductal gray matter (PAG), an area known to be sensitive to the anti-aversive effects or 5-HT, it is argued that present results may reflect increased 5-HT release at this crucial midbrain locus within the neural circuitry of defense. (C) 2002 Elsevier B.V. B.V. All rights reserved.

5-HT2 receptor activation in the midbrain periaqueductal grey (PAG) reduces anxiety-like behaviour in mice

It is widely acknowledged that the indoleamine neurotransmitter serotonin (5-HT) plays a dual role in the regulation of anxiety, a role that in part depends upon neuroanatomical locus of action. Thus, whereas stimulation of 5-HT1A or 5-HT2 receptors in the limbic forebrain (amygdala, hippocampus) enhances anxiety-like responding in rodents, activation of corresponding receptor populations in the midbrain periaqueductal grey (PAG) more often than not reduce anxiety-like behaviour. The present study specifically concerns the anxiety-modulating influence of 5-HT2 receptors within the mouse PAG. Experiment 1 assessed the effects of intra-PAG infusions of the 5-HT2B/2C receptor agonist mCPP (0, 0.03, 0.1 or 0.3 nmol/0.1 mu l) on the behaviour of mice exposed to the elevated plus-maze. As mCPP acts preferentially at 5-HT2B and 5-HT2C receptors, Experiment 2 investigated its effects in animals pretreated with ketanserin, a preferential 5-HT2A/2C receptor antagonist. In both cases, test sessions were videotaped and subsequently, scored for anxiety-like behaviour (e.g., percentage of open arm entries and percentage of open arm time) as well as general locomotor activity (closed arm entries). The results of Experiment I showed that mCPP microinfusions (0.03 and 0.1 nmol) into the PAG of mice decreased behavioural indices of anxiety without significantly altering general activity measures. In Experiment 2, the anxiolytic-like profile of intra-PAG mCPP (0.03 nmol) was substantially attenuated by intra-PAG pretreatment with an intrinsically inactive dose of the preferential 5-HT2A/2C receptor antagonist, ketanserin (10 nmol/0.1 mu l). Together, these data suggest that 5HT(2C) receptor populations within the midbrain PAG play an inhibitory role in plus-maze anxiety in mice. (C) 2007 Elsevier B.V. All rights reserved.

5-HT1B receptor in the suprachiasmatic nucleus of the common marmoset (Callithrix jacchus)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Electromyographical, ultrasonographical and morphological modifications in semitendinous muscle after transposition as ventral perineal muscle flap

The aim of this study was to evaluate modifications occurring in semitendinous muscle after transposition as a ventral perineal muscle flap using electromyography, ultrasonography, and morphological studies. Ten male crossbreed dogs of 3-4 year old were used. The left semitendinous muscle was cut close to the popliteus lymph node, rotated and sutured at the perineal region. The contralateral muscle was considered as control. Motor nerve conduction studies of both sciatic-tibial nerves, and electromyographic and ultrasonographic examinations of both semitendinous muscles were performed before surgery and 15, 30, 60, and 90 days postoperatively. Semitendinous muscle samples were collected for morphological analysis 90 days after surgery. No alterations were observed in clinical gait examinations, or in goniometrical and electroneuromyographical studies in pelvic limbs after surgery. Electromyography demonstrated that the transposed muscle was able to contract, but atrophy was detected by ultrasonography and morphological analysis.

Malignant lesions in the ventral prostate of alloxan-induced diabetic rats

The aim of this study was to evaluate the changes caused by chronic diabetes in the rat ventral prostate and to establish a correlation between diabetes and the development of prostatic lesions. Male rats received alloxan (42 mg/kg b.w.) to induce diabetes. Ninety days after diabetes diagnosis, animals were sacrificed and the ventral prostate was removed and prepared for general and immunohistochemical analyses. The total area showing different types of lesions was estimated. Diabetes led to a decrease in the body and prostatic weights, as well as in testosterone levels. The prostate morphology and stereology showed high variation in the diabetic group. Some animals had light changes; the great majority had an intense epithelial atrophy; and other rats showed premalignant and malignant lesions in the prostate. Such epithelial atrophy was, in some samples, combined with chronic inflammation, similar to proliferative inflammatory atrophy (PIA). The diabetic group also presented high incidence of prostatitis, adenocarcinoma and prostatic intra-epithelial neoplasia (PIN). Samples with adenocarcinoma had poorly differentiated acini with high levels of cellular proliferation and nuclear atypia. These lesions exhibited an invasive feature showing Bcl-2-positive cells and interruptions in the basement membrane. An association of PIA, PIN and adenocarcinoma was detected in one sample. Reduced androgen levels have a synergic effect to insulin dysfunction promoting negative effects in the rat prostate. Diabetic individuals had a high incidence of prostatitis, and this inflammation could stimulate the incidence of other forms of prostatic pathology.

Physical exercise on the rat ventral prostate: Steroid hormone receptors, apoptosis and cell proliferation

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

Aspectos morfológicos da bulla tympanica de cães após osteotomia restrita ventral e lateral

O objetivo deste trabalho foi investigar os aspectos morfológicos da bulla tympanica após osteotomia ventral e lateral. Quarenta cães adultos foram distribuídos em dois grupos de 20 animais cada. No grupo A , os animais foram submetidos a osteotomia ventral da bulla tympanica e no grupo B, a osteotomia lateral da bulla tympanica. Cada grupo foi constituído de 2 subgrupos, de acordo com o período de observação: A1 e B1 (6 semanas), A2 e B2 (12 semanas). No exame macroscópico constatou-se que a concavidade de todas as bullae tympanicae operadas era semelhante às normais. Os estudos histológicos mostraram que a regeneração completa da bulla tympanica ocorreu em apenas alguns animais de cada subgrupo. A presença de tecido conjuntivo na área de osteotomia foi verificada na maioria das bullae tympanicae operadas, resultado estatisticamente significante. A análise histológica e a histomorfometria computadorizada não mostraram diferença significante quanto ao estágio de regeneração óssea em todos os subgrupos. Concluiu-se que uma área de ostetomia restrita não causou alterações significantes na conformação da bulla tympanica de cães submetida a osteotomia ventral ou lateral; e que a regeneração total da bulla tympanica geralmente não ocorreu antes de 12 semanas de pós-operatório.

Repercussions of castration and vasectomy on the ductal system of the rat ventral prostate

Diseases. such as cancer and benign prostatic hyperplasia, are related to disruption of the mechanism regulating the balance between cell proliferation and apoptosis in prostatic cells. Since castration and vasectomy might alter that balance, this study evaluates the cell proliferation, apoptosis and height of the secretory epithelium of the ventral-prostate ductal system post-castration and vasectomy. Immunohistochemical (PCNA and Ki67), cytochemical (Fuelgen reaction) and morphometric investigation have been carried out. Cell proliferation indices decreased significantly in both regions of the ventral-prostate ductal system after castration compared to the sham-operated group. The apoptotic index increased significantly after 48 h, declining 7 days post-castration. The cell proliferation indices did not differ after 48 h significantly; however, they increased 7 days post-vasectomy in both regions. The apoptotic index did not differ significantly in either time post-vasectomy. Castration caused an imbalance in favor of apoptosis, whereas vasectomy caused an imbalance in favor of cell proliferation. (c) 2005 International Federation for Cell Biology. Published by Elsevier Ltd. All rights reserved.

Ultrastructural and proliferative features of the ventral lobe of the prostate in non-obese diabetic mice (NOD) following androgen and estrogen replacement associated to insulin therapy

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

Differential proliferative response of the ventral prostate and seminal vesicle to testosterone replacement

We have investigated epithelial cell proliferation and the rate of glandular recovery of the ventral prostate (VP) and seminal vesicle (SV) promoted by testosterone replacement (TR) in castration-induced regressed glands. Adult male Wistar rats were castrated and, after 21 days, they were treated with testosterone propionate (4 mg/kg/day). Intact (CT) and castrated rats without TR (CS) were also analysed. VP and SV were processed for histochemistry, morphometric-stereological analysis and immunocytochemistry to determine the PCNA index (PI). After 10 days of TR, the VP weight reached similar to 72% of the CT values, while the SV weight exceeded similar to 17% of the CT values. By the third day of TR, VP and SV presented a mean P1 of 34% and 94% for distal region and 14% and 22% for proximal region, respectively. SV also had more luminal cells PCNA-positive than VP, mainly in the distal region. The PI values fell on days 5, 7 and 10, but were still higher than CT. These findings indicate that epithelial cells from involuted SV are more responsive to TR than those from VP when Stimulated to proliferate and replace the luminal cell population, suggesting a different mechanism regulating cell proliferation in response to androgenic stimuli. (c) 2006 International Federation for Cell Biology. Published by Elsevier Ltd. All rights reserved.