Atividade antimutagênica de Carica papaya L. pelo ensaio do micronúcleo in vivo / Antimutagenic activity of Carica papaya L. assayed in vivo by micronucleus test

Há poucas informações sobre o efeito tóxico in vivo do extrato etanólico das folhas de Carica papaya (ECP). Portanto, esse estudo caracteriza quimicamente ECP por meio de HPLC-RP e avalia a atividade antimutagênica e citotóxica da fração aquosa de ECP422 Antimutagenic activity of Carica papaya L.Rev Ciênc Farm Básica Apl., 2011;32(3):419-423(CA), empregando ensaio do micronúcleo (MN). O extrato tem predominância de substâncias polares, entre elas a rutina. O ensaio do MN foi realizado em ratos Wistar. Grupos: Controle Negativo (CN), veículo; Controle Positivo (CP40), ciclofosfamida (40 mg/Kg i.p.), 24 horas; Grupo tratado (CA), ECP (500 mg/Kg, p.p.) 24h; Grupo Tratado (CACP40), CA (500 mg/Kg, p.o.) 48, 36 e 24 horas , a última dose de ECP foi administrada junto com ciclofosfamida (40 mg/Kg, i.p.). O índice de MN para CN e CA foi de 3,2 ± 1,79 e 1,6 ± 0,5, e razão PCE/NCE foi de 1,38 ± 0,52 e 1,13 ± 0,28, respectivamente, indicando baixa toxicidade. Por outro lado o índice de MN foi de 20 ± 4,9 para CP40 e 3,0 ± 1,6 para o CACP40, indicando efeito antimutagênico de ECP. Este estudo sugere que ECP possui efeito antimutagênico e baixa toxicidade e que a rutina pode estar envolvida nesse efeito.

There is little information about in vivo toxic effects of the ethanolic extract of leaves of Carica papaya L. (ECP). Therefore, in this study ECP was characterized chemically by HPLC-RP and the antimutagenic and cytotoxic activities of an aqueous solution of ECP (CA) were assessed by the micronucleus (MN) bioassay. The extract consisted mainly of polar substances, one of which was rutin. The MN test was performed on groups of Wistar rats, as follows: negative control (NC) - vehicle; positive control (CP40) - cyclophosphamide (40 mg/kg, ip), 24h; extract-treated (CA) - ECP (500 mg/kg, po), 24h; extract + cyclophosphamide-treated (CACP40) - ECP (500 mg/kg, po), 48, 36 and 24 h, plus cyclophosphamide (40 mg/kg, ip), 24h. The MN index was 3.2 ± 1.79 and 1.6 ± 0.5, for NC and CA, and the PCE-to-NCE ratio was 1.38 ± 0.52 and 1.13 ± 0.28, respectively, indicating low cytotoxicity of CA. CP40 showed a high MN index of 20 ± 4.9, but CACP40 only 3.0 ± 1.6, the same as NC, indicating an antimutagenic effect. The study suggests that ECP has low toxicity and possesses an antimutagenic protective effect in which rutin may be involved.

Effects of mercury intoxication on the response of horizontal cells of the retina of thraira fish (Hoplias malabaricus)

Methyl mercury (MeHg) is highly neurotoxic, affecting visual function in addition to other central nervous system functions. The effect of mercury intoxication on the amplitude of horizontal cell responses to light was studied in the retina of the fish Hoplias malabaricus. Intracellular responses were recorded from horizontal cells of fish previously intoxicated with MeHg by intraperitoneal injection (IP group) or by trophic exposure (T group). Only one retina per fish was used. The doses of MeHg chloride administered to the IP group were 0.01, 0.05, 0.1, 1.0, 2.0, and 6.0 mg/kg. The amplitudes of the horizontal cell responses were lower than control in individuals exposed to 0.01 (N = 4 retinas), 0.05 (N = 2 retinas) and 0.1 mg/kg (N = 1 retina), whereas no responses were recorded in the 1.0, 2.0, and 6.0 mg/kg groups. T group individuals were fed young specimens of Astyanax sp previously injected with MeHg corresponding to 0.75 (N = 1 retina), 0.075 (N = 8 retinas) or 0.0075 (N = 4 retinas) mg/kg fish body weight. After 14 doses, one every 5 days, the amplitude of the horizontal cell response was higher than control in individuals exposed to 0.075 and 0.0075 mg/kg, and lower in individuals exposed to 0.75 mg/kg. We conclude that intoxication with MeHg affects the electrophysiological response of the horizontal cells in the retina, either reducing or increasing its amplitude compared to control, and that these effects are related to the dose and/or to the mode of administration.

Losses of immunoreactive parvalbumin amacrine and immunoreactive alphaprotein kinase C bipolar cells caused by methylmercury chloride intoxication in the retina of the tropical fish Hoplias malabaricus

To quantify the effects of methylmercury (MeHg) on amacrine and on ON-bipolar cells in the retina, experiments were performed in MeHg-exposed groups of adult trahiras (Hoplias malabaricus) at two dose levels (2 and 6 µg/g, ip). The retinas of test and control groups were processed by mouse anti-parvalbumin and rabbit anti-alphaprotein kinase C (alphaPKC) immunocytochemistry. Morphology and soma location in the inner nuclear layer were used to identify immunoreactive parvalbumin (PV-IR) and alphaPKC (alphaPKC-IR) in wholemount preparations. Cell density, topography and isodensity maps were estimated using confocal images. PV-IR was detected in amacrine cells in the inner nuclear layer and in displaced amacrine cells from the ganglion cell layer, and alphaPKC-IR was detected in ON-bipolar cells. The MeHg-treated group (6 µg/g) showed significant reduction of the ON-bipolar alphaPKC-IR cell density (mean density = 1306 ± 393 cells/mm²) compared to control (1886 ± 892 cells/mm²; P < 0.001). The mean densities found for amacrine PV-IR cells in MeHg-treated retinas were 1040 ± 56 cells/mm² (2 µg/g) and 845 ± 82 cells/mm² (6 µg/g), also lower than control (1312 ± 31 cells/mm²; P < 0.05), differently from the data observed in displaced PV-IR amacrine cells. These results show that MeHg changed the PV-IR amacrine cell density in a dose-dependent way, and reduced the density of alphaKC-IR bipolar cells at the dose of 6 µg/g. Further studies are needed to identify the physiological impact of these findings on visual function.

Análise térmica de esparfloxacino / Thermal analysis of sparfloxacin

Foi realizada a análise térmica de esparfloxacino, fluorquinolona de terceira geração que possui potente atividade contra bactérias Gram-positivas, como Streptococcus pneumoniae e Staphylococcus aureus inclusive cepas meticilina resistentes (MRSA), bactérias Gram-negativas, anaeróbios, Legionella spp., Mycoplasma spp., Chlamydia spp. e Mycobacterium spp. Nas curvas DTA observa-se pico endotérmico de fusão na temperatura de 276,5ºC. A curva DTA, em ar sintético, apresenta dois picos exotérmicos (341,6 e 579,2ºC), atribuídos à decomposição do composto. A curva TG permite observar a perda de massa total em duas etapas, entre as temperaturas de 285,5 e 645,3ºC. A curva DTA, em atmosfera de nitrogênio, apresenta pico exotérmico de decomposição na temperatura de 340,0ºC e na curva TG, a perda de massa inicia-se na temperatura de 254,4º

Spindle cell sarcoma in Bothrops leucurus

O presente relato descreve os achados anatomopatológicos de uma neoplasia maligna em jararaca (Bothrops leucurus), mantida em cativeiro durante sete anos. O animal apresentava massa nodular subcutânea localizada no lado direito do terço anterior. O exame histológico revelou tratar-se de neoplasia mesenquimal maligna, permitindo o diagnóstico de sarcoma fusocelular

Inhibitory effect of high [Mg2+]on the vasopressin-stimulated hydroosmotic permeability of the isolated perfused cortical collecting duct

High magnesium concentration inhibits the effect of arginine vasopressin (AVP) on smooth muscle contraction and platelet aggregation and also influences hepatocyte AVP receptor binding. The aim of this study was to determine the role of magnesium concentration [Mg2+] in AVP-stimulated water transport in the kidney collecting duct. The effect of low and high peritubular [Mg2+&] on the AVP-stimulated osmotic water permeability coefficient (Pf) was evaluated in the isolated perfused rabbit cortical collecting duct (CCD). Control tubules bathed and perfused with standard Ringer bicarbonate solution containing 1 mM Mg2+ presented a Pf of 223.9 + OR - 27.2 µm/s. When Mg2+ was not added to the bathing solution, an increase in the AVP-stimulated Pf to 363.1 + OR - 57.2 µm/s (P<0.05) was observed. An elevation of Mg2+ to 5 mM resulted in a decrease in Pf to 202.9 + OR - 12.6 µm/s (P<0.05). This decrease in the AVP-stimulated Pf at 5 mM Mg2+ persisted when the CCDs were returned to 1 mM Mg2+, Pf = 130.2 + or - 20.3 µm/s, and was not normalized by the addition of 8-[4-chlorophenylthio]-adenosine 3',5'-cyclic monophosphate, a cAMP analogue, to the preparation. These data indicate that magnesium may play a modulatory role in the action of AVP on CCD osmotic water permeability, as observed in other tissues

Correlaçäo cito-histológica na punçäo aspirativa da tiróide com agulha fina / Hystocytological correlation in fine needle aspiration biopsy of the thyroid gland

A punçao aspirativa da tiróide com agulha fina (PAAF) tem sido empregada em freqüência crescente para diagnóstico de muitas doenças tiroidianas. OBJETIVO. Correlacionar os diagnósticos citológia com os anatomopatológicos para avaliar a eficácia do exame citológico como teste diagnóstico. CASUISTICA E MÉTODO. Foram comparados os diagnósticos de 328 exames citológicos de punçao aspirativa com agulha fina da tiróide com os achados anatomopatológicos das peças cirúrgicas correspontes. RESULTADOS. Em todas as doenças diagnosticadas, acurácia do exame citopatológico superou 95 por cento. Entre as doenças mais freqüentes, a sencibilidade do teste foi de 98 por cento, 69 por cento, 81 por cento, 85 por cento e 89 por cento, respectivamente, para bócio colóide nodular, neoplasia de células foliculares, tiroidite de Hashimoto, carcinoma papilar e neoplasia de células de Hürthle; em todas elas, a especificidade foi igual ou superior a 89 por cento. CONCLUSAO. Com base nesses resultados e dada sua relativa simplicidade, fica mais uma vez documentada a utilidade da PAAF como método propedêutico das doenças da tiróide.