Cardiopulmonary and analgesic effects of caudal epidurally administered ropivacaine in cattle

Objective To assess cardiopulmonary and analgesic effects after administration of ropivacaine into the caudal epidural space of cattle.Study design Prospective, single-dose trial.Animals Eight healthy mixed breed cows aged 8 +/- 5 years and weighing 507 +/- 112 kg.Methods Caudal epidural anesthesia was produced in cows with 0.75% ropivacaine (0.11 mg kg(-1)). Onset time, duration and cranial spread of analgesia were recorded. Heart rate (HR), respiratory rate (f(R)), rectal temperature (RT), and mean arterial blood pressure (MAP) were measured prior to epidural administration (T-0) and at 15, 30, 60, 120, 180 and 240 minutes after epidural administration (T-15, T-30, T-60, T-120, T-180 and T-240). Arterial blood acid-base balance (pH, standard bicarbonate and base excess), gas tension (PaO2, PaCO2, SaO(2)) and electrolytes (Na+, K+, iCa(2+), Cl-) were recorded at T-0, T-30, T-60, T-120, T-180 and T-240. Ataxia was evaluated at T-0, T-30, T-60, T-120, T-180 and T-240 and at 1 hour intervals thereafter until analgesia was no longer present in each animal.Results Epidurally administered ropivacaine induced variable analgesia extending bilaterally from the coccyx to S3. Time to onset of analgesia and mean duration in the perineal area were 15 +/- 4 and 359 +/- 90 minutes, respectively. Respiratory rate and RT increased from T-120 to T-240 when compared to the value at T-0. Ionized calcium and chloride concentrations increased at T-180 and T-240 when compared to T-0. The other variables were not significantly different from baseline values (p > 0.05). Four animals were mildly ataxic.Conclusion and clinical relevance Ropivacaine (0.75%, 0.11 mg kg(-1)) can be administered by caudal epidural injection to produce prolonged bilateral perineal analgesia with minimal ataxia and cardiopulmonary changes in standing cattle.

Effects of fluoride intake on insulin sensitivity and insulin signal transduction

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

Neuroendocrine and reproductive aspects of adult male rats exposed neonatally to an antiestrogen

The present study was designed to investigate the effects of a single dose of an estrogen antagonist-clomiphene-during neonatal life, on later neuroendocrine system and reproductive performance. Immediately after birth, male pups received clomiphene citrate (s.c.). At adulthood, although testosterone levels and wet weights of reproductive organs were not altered, the treatment induced an increased number of spermatozoa and a delay in the transit time in the cauda epididymis. Additionally, there was impairment of sexual behavior evidenced by a delay in the latencies to the first mount and first intromission. Treated rats also showed decreased dopaminergic and serotonergic neurotransmissions in the hypothalamus and decreased dopaminergic neurotransmission in the striatum. The decreased dopaminergic activity could be related to the lower sexual motivation observed. These results indicate the necessity of preventing exposure to drugs that may impair sexual differentiation, which can compromise later mating success as well as the capacity to generate descendants. (c) 2006 Elsevier B.V. All rights reserved.

Effects of the essential oil from Citrus aurantium L. in experimental anxiety models in mice

Citrus aurantium L. is popularly used to treat anxiety, among other indications suggesting central nervous system action. Previous studies showed anxiolytic effect in the essential oil from peel in mice evaluated on the elevated plus maze [Carvalho-Freitas, M.I.R., Costa, M., 2002. Anxiolytic and sedative effects of extracts and essential oil from Citrus aurantium L. Biological and Pharmaceutical Bulletin 25, 1629-1633.]. In order to better characterize the activity of the essential oil, it was evaluated in two other experimental models: the light-dark box and the marble-burying test, respectively related to generalized anxiety disorder and to obsessive compulsive disorder. Mice were treated acutely by oral route 30 min (single dose) or once a day for 15 days (repeated doses) before experimental procedures. In light-dark box test, single treatment with essential oil augmented the time spent by mice in the light chamber and the number of transitions between the two compartments. There were no observed alterations in the parameters evaluated in light-dark box after repeated treatment. Otherwise, single and repeated treatments with essential oil were able to suppress marble-burying behavior. At effective doses in the behavioral tests, mice showed no impairment on rotarod procedure after both single and repeated treatments with essential oil, denoting absence of motor deficit. Results observed in marble-burying test, related to obsessive compulsive disorder, appear more consistent than those observed in light-dark box. (c) 2005 Elsevier B.V. All rights reserved.

Can a Strychnos species be used as antiulcer agent? Ulcer healing action from alkaloid fraction of Strychnos pseudoquina St. Hil. (Loganiaceae)

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

Propolis effect on streptozotocin-induced diabetic rats

Propolis is one of the hive products that has been used extensively in folk medicine, due to its several biological and pharmacological properties. Besides, propolis-containing products have been intensely marketed by the pharmaceutical industry and health-food stores. This work was carried out in order to investigate whether propolis treatment could revert the metabolic alterations of streptozotocin-induced diabetic rats. Animals were kept in metabolic cages and diabetes was induced by a single dose of streptozotocin (35 mg/kg, IV). After a week, rats with glycemia higher than 230 mg/dL were divided into two groups and treated with ethanolic extract of propolis (10 and 90 mg/kg, PO) for seven days. Glycemia and free fatty acids were determined, as well as food and water intake, body weight and urine volume were registered weekly. Data showed no significant differences in the analyzed variables. Based on these results, one may conclude that propolis had no effects after diabetes establishment, in our conditions assays. Further assays with different concentrations of propolis and periods of administration should be carried out in order to evaluate its therapeutic potential in this disease.

Assessment of Female Reproductive Endpoints in Sprague-Dawley Rats Developmentally Exposed to Diuron: Potential Ovary Toxicity

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

Long-term physical training increases liver IGF-I in diabetic rats

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Microscopic comparative study of the exposure effects of testosterone cypionate and ethinylestradiol during prenatal life on the prostatic tissue of adult gerbils

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

Avaliação da mutagenicidade e antimutagenicidade de um biopolímero extraído do microorganismo Agrobacterium radiobacter em camundongos Swiss

A presente pesquisa avaliou a ação mutagênica e antimutagênica de um biopolímero de glucose extraído da Agrobacterium radiobacter (Biopolímero de Agrobacterium radiobacter). O experimento foi realizado com camundongos Swiss machos divididos em oito grupos. O tratamento com o biopolímero foi realizado por gavage em dose única concomitante a uma dose de solução tampão fosfato nos grupos de avaliação da mutagenicidade, ou ao agente indutor de danos no DNA, ciclofosfamida, na concentração de 50 mg/kg (peso corpóreo - p.c.), nos grupos de avaliação da antimutagenicidade. Utilizou-se o teste de micronúcleo em sangue periférico e a coleta de sangue foi realizada 24 e 48 h após a aplicação das substâncias-teste. A análise estatística demonstrou que o biopolímero não possui atividade mutagênica e que é efetivo em prevenir danos no DNA. As porcentagens de redução de danos nos grupos de antimutagenicidade foram de 83,9%, 89,1% e 103,1% em 24 h e 101,24%, 98,14% e 120,64% em 48 h para as doses de 75, 150 e 300mg/kg (p.c.), respectivamente. A alta porcentagem de redução de danos associada à ausência de efeitos mutagênicos indica, além da atividade quimioprotetora, a possibilidade do biopolímero ser um alimento funcional candidato à utilização como co-adjuvante na quimioterapia para prevenir efeitos colaterais.

Avaliação laboratorial do uso de solução salina hipertônica e isotônica e de furosemida no tratamento da intoxicação por amônia em bovinos

Para testar a eficiência de vários tratamentos de intoxicação por amônia em bovinos, foram utilizados 25 garrotes que receberam cloreto de amônio por infusão intravenosa (iv) até o surgimento de quadro convulsivo. em seguida, os animais foram alocados em um dos cinco grupos experimentais e tratados da seguinte forma: 1) controle: infusão (iv) de 300mL de solução salina isotônica (SSI), no decorrer de 4h; 2) infusão (iv) de 30mL kg-1 PV de SSI no decorrer de 4h e administração de 4L de água intraruminal por meio de sonda esofágica (ASE); 3) mesmo tratamento do grupo 2 e dose única (iv) de furosemida (2mg kg-1 PV) (F); 4) injeção (iv) de 5mL kg-1 PV de solução salina hipertônica (SSH) 7,2% nos primeiros 30min, seguida de 20mL kg-1 PV de SSI e 4L de ASE; 5) mesmo tratamento do grupo 4 e dose única de F. No decorrer de 4h após a convulsão, foram determinados os teores plasmáticos de amônia e glicose, ureia, creatinina, potássio e sódio séricos, volume e gravidade específica da urina, e excreção urinária de amônio e ureia. No momento da convulsão, os teores de amônia plasmáticos foram muito altos e idênticos em todos os tratamentos, mas no 120°min, nos grupos tratados com associação de SSH+SSI+ASE (grupos 4 e 5), houve diminuição desse metabólito. O uso de furosemida (grupos 3 e 5) não aumentou a excreção total de urina. A terapia com associação de SSH+SSI+ASE aumentou ainda o volume urinário e a excreção percentual urinária de ureia e amônia durante o período crítico da 1ª hora de tratamento, mas o uso de SSI+ASE (grupos 2 e 3) teve resultados intermediários. A eficiência do tratamento com SSH+SSI+ASE ou SSI+ASE foi superior ao grupo controle. Embora com efeito menor que o observado com SSH+SSI+ASE, a SSI+ASE promoveu melhora no quadro clínico geral e, ao término do experimento, promoveu também uma adequada desintoxicação da amônia.

Modulation of parasitemia and antibody responce to Trypanosoma cruzy by cyclophosphamide in Calomys callosus (Rodentia, Cricetidae)

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

Uso da ciclofosfamida em modelo de imunodepressão experimental em ovinos

Cyclophosphamide (CY) was used to evaluate the effect on the immune system of sheep. Castred adult rams were divided into 3 groups, with 6 animals each one. Group I (day 0) and Group II (day 1) were treated with CY (40 mg/kg, single dose, IV), and Group III was not treated and remained as control. All groups were immunized on day 0 with B19 brucellosis vaccine. on day 6, all animals were bled and serum agglutination test for brucellosis antibodies detection was performed. During 7 days blood lymphocyte counts and electrophoresis gammaglobulin dosage were daily performed. The results showed statistical decrease of immune response. Low serum titers of brucellosis antibodies were found in Groups I and II, and lymphopenia and hypogammaglobulinemia were also found in these groups. A high mortality rate (40%) occurred in the treated animals.

Long-term accumulation and microdistribution of uranium in the bone and marrow of beagle dog

The accumulation and microdistribution of uranium in the bone and marrow of Beagle dogs were determined by both neutron activation and neutron-fission analysis. The experiment started immediately after the weaning period, lasting till maturity. Two animal groups were fed daily with uranyl nitrate at concentrations of 20 and 100 mug(-1) food. of the two measuring techniques, uranium accumulated along the marrow as much as in the bone, contrary to the results obtained with single, acute doses. The role played by this finding for the evaluation of radiobiological long-term risks is discussed. It was demonstrated, by means of a biokinetical approach, that the long-term accumulation of uranium in bone and marrow could be described by a piling up of single dose daily incorporation.

MODULATION OF PARASITEMIA AND ANTIBODY-RESPONSE TO TRYPANOSOMA-CRUZI BY CYCLOPHOSPHAMIDE IN CALOMYS-CALLOSUS (RODENTIA, CRICETIDAE)

Calomys callosus a wild rodent, previously described as harboring Trypanosoma cruzi, has a low susceptibility to infection by this protozoan.Experiments were designed to evaluate the contribution of the immune response to the resistance to T. cruzi infection exhibited by C. callosus. Animals were submitted to injections of high (200 mg/kg body weight) and low (20 mg/kg body weight) doses of cyclophosphamide on days -1 or -1 and +5, and inoculated with 4 x 10(3) T. cruzi on day O. Parasitemia, mortality and antibody response as measured by direct agglutination of trypomastigotes were observed. Two hundred mg doses of cyclophosphamide resulted in higher parasitemia and mortality as well as in suppression of the antibody response. A single dose of 20 mg enhanced antibody levels on the 20th day after infection, while an additional dose did not further increase antibody production. Parasitemia levels were not depressed, but rather increased in both these groups as compared to untreated controls. Passive transfer of hyperimmune C. callosus anti-T. cruzi serum to cyclophosphamide immunosuppressed animals resulted in lower parasitemia and mortality rates. These results indicate that the immune response plays an important role in the resistance of C. callosus to T. cruzi.