Potencial cicatricial da Bixa orellana L. em feridas cutâneas: estudo em modelo experimental / Therapeutic potential of Bixa orellana L. in skin wounds: a study in the rat model of open wound healing

O uso de fitoterápicos é uma alternativa de baixo custo e de fácil acesso para o tratamento de feridas cutâneas. Objetivou-se avaliar a ação do extrato oleoso de urucum na cicatrização de feridas cutâneas abertas. Inicialmente, identificaram-se os principais ácidos graxos do óleo de urucum. Foi realizado ensaio citotóxico para determinar as concentrações a serem utilizadas no ensaio in vivo. No experimento, feridas cutâneas em ratos Wistar foram diariamente tratadas com: extrato de urucum 0,1% (U 0,1%), extrato de urucum 0,01% (U 0,01%), vaselina (V) e solução fisiológica (SF), por até 21 dias. Aos quatro, sete, 14 e 21 dias, foi avaliada clinicamente a presença de exsudato, crosta e epitelização. Determinaram-se as áreas da lesão, e amostras de pele, fígado e rins foram coletadas para avalição histológica. Aos 21dias, amostras de pele foram coletadas para análise tensiométrica. Clinicamente, todos os grupos de tratamento apresentaram evolução cicatricial fisiológica. Os grupos U 0,1% e U 0,01% apresentaram maior presença de epitelização aos sete dias e maior retração cicatricial aos quatro dias. Na histologia, U 0,1% e U 0,01% apresentaram aos quatro e sete dias maior quantidade de fibrina e inflamação que V e SF, e, nos demais momentos, não houve diferenças entre os grupos. Quanto à fase cicatricial, aos quatro dias todos os grupos encontravam-se na fase inflamatória, aos sete dias U 0,1% e U 0,01% permaneciam na fase inflamatória, diferindo de SF e V, que se caracterizavam na fase proliferativa. Aos 14 dias, os grupos apresentavam-se em transição de fase proliferativa para maturação e, aos 21dias, estavam todos na fase de maturação. Os grupos tratados com urucum expressaram menor resistência à tensão que V e SF. Concluiu-se com este estudo que o extrato oleoso de urucum acelera o processo cicatricial nos primeiros dias, mas proporciona uma cicatriz de baixa qualidade.

Phytotherapies are a low cost, easily accessible alternative to traditional medicines in wound healing management. The purpose of this study was to assess the oil extract of Bixa orellana L. as a healing agent in the rat model of open wound healing. Initially, the oil was obtained and characterized through gas chromatography. Furthermore, the cytotoxic potential of the oil was verified in cell cultures to determine the doses used in animal experiments. Wounds were surgically produced in Wistar rats, these were treated with the oil extract at 0.1% (U 0.1%), 0.01% (U 0.01%), petrol jelly (V) and saline (SF) for up to 21 days. At four, seven and 14 days of treatment the wounds were assessed clinically regarding the presence of exudate, crust and epithelialization. The wound area was also determined and skin, kidney and liver tissues were harvested for histopathology. At 21 days of treatment the skins were also harvested for tension resistance assessment. Clinically, all groups evolved similarly, however, those treated with U 0.1% and U 0.01% had a greater amount of epithelialized wounds by day seven, and grater shrinkage by day four. Histopathologicaly, the skin samples of oil treated wounds had more lesions in the inflammatory phase at seven days, when compared to the controls, which were majorly in the proliferation phase. By 14 days no difference was observed among groups, which were all in the transition from the proliferation to the maturation phase. By day 21, all wounds were in the maturation phase. Oil treated wounds also had more fibrin in the first two assessment dates, when compared to the controls. Tension resistance of the oil treated wounds was, however, inferior to that of the controls. This study shows that B. orellana L. oil will hasten the onset of the healing process and its initial phases, but will ultimately produce a scar of poorer quality.

Reactive nitrogen species mediate oxidative stress and astrogliosis provoked by in vivo administration of phytanic acid in cerebellum of adolescent rats: A potential contributing pathomechanism of cerebellar injury in peroxisomal disorders.

Phytanic acid (Phyt) accumulates in various peroxisomal diseases including Refsum disease (RD) and Zellweger syndrome (ZS). Since the pathogenesis of the neurological symptoms and especially the cerebellar abnormalities in these disorders are poorly known, we investigated the effects of in vivo intracerebral administration of Phyt on a large spectrum of redox homeostasis parameters in the cerebellum of young rats. Malondialdehyde (MDA) levels, sulfhydryl oxidation, carbonyl content, nitrite and nitrate concentrations, 2',7'-dichlorofluorescein (DCFH) oxidation, total (tGS) and reduced glutathione (GSH) levels and the activities of important antioxidant enzymes were determined at different periods after Phyt administration. Immunohistochemical analysis was also carried out in the cerebellum. Phyt significantly increased MDA and nitric oxide (NO) production and decreased GSH levels, without altering tGS, DCFH oxidation, sulfhydryl oxidation, carbonyl content and the activities of glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR) and glucose-6-phosphate dehydrogenase (G6PD). Furthermore, immunohistochemical analysis revealed that Phyt caused astrogliosis and protein nitrosative damage in the cerebellum. It was also observed that the NO synthase inhibitor Nω-Nitro-L-arginine methyl ester (L-NAME) prevented the increase of MDA and NO production as well as the decrease of GSH and the immunohistochemical alterations caused by Phyt, strongly suggesting that reactive nitrogen species (RNS) were involved in these effects. The present data provide in vivo solid evidence that Phyt disrupts redox homeostasis and causes astrogliosis in rat cerebellum probably mediated by RNS production. It is therefore presumed that disequilibrium of redox status may contribute at least in part to the cerebellum alterations characteristic of patients affected by RD and other disorders with Phyt accumulation.

Use of Triticum aestivum in open wound healing: a clinical, pathological, and tensiometric assessment in the rabbit model / Uso de Triticum aestivum na cicatrização de feridas: um ensaio clínico, histopatológico e tensiométrico em coelhos

While Triticum sp. has been shown to act in wound healing, stimulating collagen synthesis by fibroblasts, the use of this plant extract has yet to be assessed in vivo, in commercially viable presentations. This study used rabbits and assessed, on days seven, 14, and 21, the presence or absence of granulation tissue and epithelialization, histopathological structures, and scar quality through the breaking and tension strength. Treatments, performed for 21 days, were aqueous extract of T. aestivum at a concentration of 2mg/mL (group I) and 10mg/mL (group II) and a nonionic cream (control group). We demonstrate that the formation of granulation tissue was not significantly different between treatments. In the analysis of epithelial tissue, wounds in group II differed from other treatments by day 7. On days 14 and 21 there was no significant clinical difference between groups. In the histopathological evaluation, scar quality and rupture strength did not differ between the groups in the studied period. In the tension strength evaluation, group I differed from the others, presenting a higher tension strength overall. The studied treatments did not differ regarding healing evolution of the skin wounds, but T. aestivum extract, at 2mg/mL, presents better results in the tension strength evaluation...

O extrato de trigo (Triticum sp.) vem sendo usado na cicatrização de feridas por estimular a síntese de fibroblastos, entretanto a sua aplicabilidade in vivo em apresentações comercialmente viáveis ainda tem de ser demonstrada. Neste estudo, avaliaram-se feridas cutâneas de coelhos tratadas com extrato aquoso de T. aestivum quanto à presença de tecido de granulação e epitelização, estruturas histológicas, qualidade cicatricial, além de ensaio tensiométrico. As feridas foram tratadas diariamente, por 21 dias, com diferentes concentrações do extrato (grupo I = 2mg/mL; grupo II = 10mg/mL) ou apenas o veículo (grupo controle = creme não iônico), e avaliadas nos dias sete, 14 e 21. A formação de tecido de granulação não diferiu entre os tratamentos. A epitelização aconteceu em menor tempo em feridas do grupo II, mas aos 14 dias já não havia diferença neste parâmetro. Na avaliação histopatológica, a qualidade cicatricial e a força de ruptura não diferiram no período estudado, entretanto a resistência tensiométrica das feridas do grupo I foi maior que a dos demais tratamentos. Dessa forma, conclui-se que, mesmo não havendo diferença na evolução cicatricial de feridas tratadas ou não com extrato aquoso de T. aestivum, o uso desse composto, a 2mg/mL, resultou em tecidos cicatriciais mais resistentes à tração...

Condrossarcoma mesenquimal extraesquelético em um gato: relato de caso / Extraskeletal mesenchymal chondrosarcoma in a cat: case report

Condrossarcoma mesenquimal extraesquelético (CME) é um neoplasma maligno e raro em animais domésticos. Descreve-se um caso de CME em uma gata que apresentava uma massa firme, branco-amarelada, medindo 18cm de diâmetro, aderida à musculatura do membro pélvico esquerdo. O exame citológico revelou presença de células fusiformes individualizadas pleomórficas e agregados de pequenas células ovais, sem bordas definidas em meio à matriz intercelular amorfa. Devido à impossibilidade de tratamento e ao prognóstico desfavorável, foi realizada eutanásia. Microscopicamente foram observadas células fusiformes indiferenciadas e agregados de células condroides pleomórficas. O diagnóstico de CME foi confirmado pelas técnicas de azul alciano, tricrômico de Masson e pela prova imunoistoquímica, utilizando-se anticorpos antivimentina...

Extraskeletal mesenchymal chondrosarcoma (EMC) is a rare malignant tumor in domestic animals. We described a case of EMC in a cat with a mass measuring 18cm in diameter, yellowish-white and firm attached to the muscles in left hind limb. Cytological examination revealed the presence of individual pleomorphic spindle cells and clusters of small oval cells with no hard edges in the midst of an amorphous intercellular matrix. Due to the impossibility of treatment and poor prognosis, the cat was euthanized. Microscopically undifferentiated spindle cells and clusters of pleomorphic chondroid cells were observed. The CME diagnosis was confirmed with thealcian blue, Masson's trichrome and immunohistochemistry techniques, using antivimentin antibodies...

Redox homeostasis is compromised in vivo by the metabolites accumulating in 3-hydroxy-3-methylglutaryl-CoA lyase deficiency in rat cerebral cortex and liver.

3-Hydroxy-3-methylglutaryl-CoA lyase (HL) deficiency is a disorder biochemically characterized by the predominant accumulation of 3-hydroxy-3-methylglutarate (HMG), 3-methylglutarate (MGA), 3-methylglutaconate and 3-hydroxyisovalerate in tissues and biological fluids of the affected patients. Neurological symptoms and hepatopathy are commonly found in HL deficiency, especially during metabolic crises. Since the mechanisms of tissue damage in this disorder are not well understood, in the present study we evaluated the ex vivo effects of acute administration of HMG and MGA on important parameters of oxidative stress in cerebral cortex and liver from young rats. In vivo administration of HMG and MGA provoked an increase of carbonyl and carboxy-methyl-lysine formation in cerebral cortex, but not in liver, indicating that these metabolites induce protein oxidative damage in the brain. We also verified that HMG and MGA significantly decreased glutathione concentrations in both cerebral cortex and liver, implying a reduction of antioxidant defenses. Furthermore, HMG and MGA increased 2',7'-dichlorofluorescin oxidation, but did not alter nitrate and nitrite content in cerebral cortex and liver, indicating that HMG and MGA effects are mainly mediated by reactive oxygen species. HMG and MGA also increased the activities of superoxide dismutase and catalase in cerebral cortex and liver, whereas MGA decreased glutathione peroxidase activity in cerebral cortex. Our present data showing a disruption of redox homeostasis in cerebral cortex and liver caused by in vivo administration of HMG and MGA suggest that this pathomechanism may possibly contribute to the brain and liver abnormalities observed in HL-deficient patients.

Resposta clínica e metabólica de potros neonatos em relação aos achados histopatológicos da placenta na égua / Clinical and metabolic response of neonatal foals related to histopathology finds in mare placenta

Avaliaram-se as respostas clínica e metabólica de potros neonatos em relação aos achados histopatológicos da placenta na égua. Foram avaliados dois grupos de éguas da raça Puro Sangue Inglês - um grupo-problema (n=25) e um grupo-controle (n=25), de acordo com os achados da placenta. O exame dos potros constou de avaliação clínica geral, hematologia e bioquímica sérica. O exame histopatológico da placenta apresentou resultado compatível com a apresentação clínica do potro, sendo que a presença de lesões inflamatórias resultou na produção de potros debilitados. A presença de lesões degenerativas não comprometeu o estado clínico do neonato, mas pode ser responsável pela manifestação de distúrbios subclínicos, evidenciados pelo aumento das taxas de AST e GGT. A ureia pareceu ser um indicador de dano renal decorrente de insuficiência placentária em potros neonatos.

The placenta represents the major communication between the mare and the fetus during the gestational period, and this suggests that any disturbance in the placenta can be an indicator of gestational damage with risk to the fetus. The aim of this paper was to evaluate the clinical and metabolic responses of the newborn foals related with the findings from the histopathological examination of the placenta. This study was conducted in a farm located in Bagé-RS, Brazil, where were evaluated two groups of Throughbred mares for this case-control study: One Problem Group (N=25) and the Control Group (n=25), based on the placental findings. The foal's evaluation was based on general clinical examination, hematology and serum biochemistry. Results from the placenta histopathological exams were compatible with clinical presentation of the foals, with the presence of inflammatory lesions resulting in the production of debilitated foals. The presence of degenerative lesions in the placenta does not compromise the clinical features of the newborn, but they can be responsible for the manifestation of sub-clinical disturbances, evidenced by increased levels of AST and GGT. Urea seems to be an indicator of renal damage due to placental insufficiency in neonatal foals.

Ethidium bromide-induced demyelination of the sciatic nerve of adult Wistar rats

Peripheral nerve ultrastructure was assessed after single or multiple local injections of the intercalating dye ethidium bromide. Thirty-four adult Wistar rats of both sexes were divided into five groups and maintained in a controlled environment with rat chow and water ad libitum throughout the experiment. The experimental animals were injected with 1 æl of 0.1 percent ethidium bromide in 0.9 percent saline into the central third of the left sciatic nerve 1 (group 1), 2 (group 2), 4 (group 3), 6 (group 4) or 8 (group 5) times. In groups 2 to 5 the injections were made at 28-day intervals. Control animals received the same amount of 0.9 percent saline. The animals were killed at different times after injection: group 1 at 7 days (2 rats) and 15 days (2 rats); for groups 2, 3, 4 and 5, all rats were killed 10 days after the last injection and the lesions were investigated by light and transmission electron microscopy. In the acute lesions, intoxicated Schwann cells showed a vacuolated cytoplasm and separation of the sheaths from the axon. Myelin sheaths underwent progressive vesiculation and subsequent segmental demyelination. Myelin debris were withdrawn by macrophages and remyelination by Schwann cells was prominent. With the increase in the number of injections collagen fibers also increased in number and progressively enveloped smaller numbers of remyelinated axons composing new fascicles. Wallerian degeneration of fibers apparently not affected by ethidium bromide was more intense in the nerves from groups 4 and 5. The peripheral nerve repairs itself after demyelinating challenges with a profusion of collagen fibers and new fasciculations. This experimental model is valid to mimic recurrent demyelinating neuropathies

Ethidium bromide-induced demyelination of the sciatic nerve of adult Wistar rats.

Peripheral nerve ultrastructure was assessed after single or multiple local injections of the intercalating dye ethidium bromide. Thirty-four adult Wistar rats of both sexes were divided into five groups and maintained in a controlled environment with rat chow and water ad libitum throughout the experiment. The experimental animals were injected with 1 microl of 0.1% ethidium bromide in 0.9% saline into the central third of the left sciatic nerve 1 (group 1), 2 (group 2), 4 (group 3), 6 (group 4) or 8 (group 5) times. In groups 2 to 5 the injections were made at 28-day intervals. Control animals received the same amount of 0.9% saline. The animals were killed at different times after injection: group 1 at 7 days (2 rats) and 15 days (2 rats); for groups 2, 3, 4 and 5, all rats were killed 10 days after the last injection and the lesions were investigated by light and transmission electron microscopy. In the acute lesions, intoxicated Schwann cells showed a vacuolated cytoplasm and separation of the sheaths from the axon. Myelin sheaths underwent progressive vesiculation and subsequent segmental demyelination. Myelin debris were withdrawn by macrophages and remyelination by Schwann cells was prominent. With the increase in the number of injections collagen fibers also increased in number and progressively enveloped smaller numbers of remyelinated axons composing new fascicles. Wallerian degeneration of fibers apparently not affected by ethidium bromide was more intense in the nerves from groups 4 and 5. The peripheral nerve repairs itself after demyelinating challenges with a profusion of collagen fibers and new fasciculations. This experimental model is valid to mimic recurrent demyelinating neuropathies.

Behaviour of oligodendrocytes and Schwann cells in an experimental model of toxic demyelination of the central nervous system.

Oligodendrocytes and Schwann cells are engaged in myelin production, maintenance and repairing respectively in the central nervous system (CNS) and the peripheral nervous system (PNS). Whereas oligodendrocytes act only within the CNS, Schwann cells are able to invade the CNS in order to make new myelin sheaths around demyelinated axons. Both cells have some limitations in their activities, i.e. oligodendrocytes are post-mitotic cells and Schwann cells only get into the CNS in the absence of astrocytes. Ethidium bromide (EB) is a gliotoxic chemical that when injected locally within the CNS, induce demyelination. In the EB model of demyelination, glial cells are destroyed early after intoxication and Schwann cells are free to approach the naked central axons. In normal Wistar rats, regeneration of lost myelin sheaths can be achieved as early as thirteen days after intoxication; in Wistar rats immunosuppressed with cyclophosphamide the process is delayed and in rats administered cyclosporine it may be accelerated. Aiming the enlightening of those complex processes, all events concerning the myelinating cells in an experimental model are herein presented and discussed.

Diagnóstico de leishmaniose canina na área urbana do município de Cuiabá, Estado de Mato Grosso, Brasil / Diagnosis of canine leishmaniasis in the urban area of the District of Cuiabá, State of Mato Grosso, Brazil

Iniciou-se um estudo sobre a ocorrência de leishmaniose visceral e tegumentar em cäes da área urbana de Cuiabá, Estado de Mato Grosso. No período de agosto de 1997 a julho de 1998, foram coletadas amostras de sangue de 800 cäes, de diferentes bairros de Cuiabá, escolhidos aleatoriamente, e remetidos ao Serviço de Parasitologia do Instituto Municipal de Medicina Veterinária Jorge Vaitsman, no Rio de Janeiro, para exame pelo teste de imunofluorescência indireta. Foram processadas preliminarmente 62 amostras de soro, das quais 64,5 por cento (40 amostras) estavam positivas para leishmaniose. Quanto às titulaçöes encontradas nos soros reagentes, 92,5 por cento (37 amostras) apresentaram títulos acima de 1:160, sugerindo forte suspeita da presença de leishmaniose visceral. Deste total, 72,5 por cento (29 amostras) dos soros positivos sao provenientes de cäes da regiäo Sul-Leste e 27,5 por cento (11 amostras) da regiäo Centro-Leste de Cuiabá. Este é o primeiro registro da detecçäo de cäes sorologicamente positivos para leishmaniose em área urbana do Estado de Mato Grosso

Inflammatory response of the spinal cord to multiple episodes of blood-brain barrier disruption and toxic demyelination in Wistar rats.

Multiple episodes of blood-brain barrier disruption were induced by sequential intraspinal injections of ethidium bromide. In addition to the barrier disruption, there was toxic demyelination and exposure of myelin components to the immune system. Twenty-seven 3-month-old Wistar rats received 2, 3 or 4 injections of 1 microliter of either 0.1% ethidium bromide in normal saline (19 rats) or 0.9% saline (8 rats) at different levels of the spinal cord. The time intervals between the injections ranged from 28 to 42 days. Ten days after the last injection, all rats were perfused with 2.5% glutaraldehyde. The spinal sections were evaluated macroscopically and by light and transmission electron microscopy. All the lesions demonstrated a mononuclear phagocytic infiltrate apparently removing myelin. Lymphocytes were not conspicuous and were found in only 34% of the lesions. No perivascular cuffings were detected. In older lesions (38 days and older) they were found only within Virchow-Robin spaces. This result suggests that multiple blood-brain barrier disruptions with demyelination and exposure of myelin components to the immune system were not sufficient to induce an immune-mediated reaction in the central nervous system.

Inflammatory response of the spinal cord to multiple episodes of blood-brain barrier disruption and toxic demyelination in Wistar rats

Multiple episodes of blood-brain barrier disruption were induced by sequential intraspinal injections of ethidium bromide. In addition to the barrier disruption, there was toxic demyelination and exposure of myelin components to the immune system. Twenty-seven 3-month-old Wistar rats received 2, 3 or 4 injections of 1 mul of either 0.1 percent ethidium bromide in normal saline (19 rats) or 0.9 percent saline (8 rats) at different levels of the spinal cord. The time intervals between the injections ranged from 28 to 42 days. Ten days after the last injection, all rats were perfused with 2.5 percent glutaraldehyde. The spinal sections were evaluated macroscopically and by light and transmission electron microscopy. All the lesions demonstrated a mononuclear phagocytic infiltrate apparently removing myelin. Lymphocytes were not conspicuos and were found in only 34 percent of the lesions. No perivascular cuffings were detected. In older lesions (38 days and older) they were found only within Virchow-Robin spaces. This result suggests that multiple blood-brain barrier disruptions with demyelination and exposure of myelin components to the immune system were not sufficient to induce an immune-mediated reaction in the central nervous system.

Artificial feeding of Amblyomma cajennense (Fabricius, 1787) (Acari:Ixodidae) through silicone membrane.

An artificial feeding system was used where citrated bovine blood was offered to male and female Amblyomma cajennense. Vestiges of blood, sweat, hair and exfoliated skin were used as phago-stimulants placed on the surface of the silicone membrane. The ticks were collected, as engorged nymphs, from naturally infested equines, with the ecdysis occurring in the laboratory. Four hundred ticks were used, 50% being female, at three to four weeks post-ecdysis. Vestiges of blood on the silicone membrane were the most efficient phago-stimulant and the association of vestiges of blood and sweat residue smears yielded better results compared to the other phago-stimulants used.

[Demyelination and remyelination after multiple intramedullary injections of ethidium bromide in Wistar rats]. / Desmielinização e remielinização após múltiplas injeções intramedulares de brometo de etídio em ratos wistar.

The ethidium bromide model of demyelination has been employed to study the central nervous system response to several episodes of demyelination. Twenty-seven Wistar rats received 2 to 4 intraspinal injections of 1 microliter of either 0.1% ethidium bromide in normal saline (19 rats) or saline 0.9% (8 rats) in different anatomical locations. The intervals between the injections ranged from 28 to 42 days. Ten days after the last injection all the rats were perfused with 2.5% glutaraldehyde. The spinal sections were evaluated macroscopically and by light and transmission electron microscopy. The lesions were typical of focal primary demyelination with preserved vascular structures and followed by remyelinization and varied in size and histological aspects. After multiple sequential ethidium bromide injections, the central nervous system seems to modify its response capacity to an inflammatory challenge although there is no change in its pattern of remyelination.