Cold stress on Araucaria angustifolia embryogenic cells results in oxidative stress and induces adaptation: implications for conservation and propagation.

Araucaria angustifolia (Bert.) O. Kuntze is a species critically endangered of extinction and its development and propagation is strongly affected by abiotic stress. We have previously shown the activation of uncoupling protein in A. angustifolia embryogenic stem cells subjected to cold stress. Now, we have furthered those studies by exposing these cells to cold stress (4 ± 1 °C for either 24 or 48 h) and evaluating parameters associated with oxidative stress and alterations in the cellular and mitochondrial responses. Cold stress affect the H2O2 levels and lipid peroxidation increased after both stress condition, an effect associated with the decrease in the activities of peroxidases, catalase and ascorbate/dehydroascorbate ratio. On the other hand, the activities of ascorbate peroxidase, monodehydroascorbate and dehydroascorbate reductases increased as an indication of adaptation. Another important impact of cold stress conditions was the decrease of external alternative NAD(P)H dehydrogenases activity and the increase of mitochondrial mass. These results show that cold stress induces oxidative stress in A. angustifolia embryogenic cells, which results in activation of the glutathione-ascorbate cycle as a compensation for the decrease in the activities of catalase, peroxidases, and external NAD(P)H dehydrogenases. Our results contribute to the understanding of the pathways that gymnosperms employ to overcome oxidative stress, which must be explored in order to improve the methods of conservation and propagation of A. angustifolia.

[Canine visceral leishmaniasis in northeast Brazil: epidemiological aspects]. / La leishmaniose viscérale canine dans le Nord-Est du Brésil: aspects épidémiologiques.

In a rural area of Northeast Brazil, the relatively high serological infection by Leishmania in dogs, the lack of classical vector Lutzomyia longipalpis and of American Visceral Leishmaniasis cases in human beings and the observation of Leishmania in ticks collected in infected dogs suggest that ticks may be responsible for the transmission between dogs.

Avaliação da sensibilidade e especificidade da metodologia de enzimaimunoensaio com micropartículas para dosagem de ferritinas / Sensibility and specificity evaluation of microparticle enzyme immunoassay method for ferritin measurement

A ferritina é a principal preteína envolvida no armazenamento de ferro, sendo encontrada no meio intracelular e também como um constituinte normal do plasma, fluídos corporais e das hemácias circulantes. Ferritinas derivadas de diferentes tecidos apresentam distintas propriedades como: estrutura primária, teor de fosfato no núcleo mineral, mobilidade eletroforética e proporção relativa de subunidades H e L, determinando diferenças estruturais, imunológicas, em ponto isoelétrico e capacidade oxidativa. estudos demonstram a relação direta entre a concentração de ferritina no soro e os estoques de ferro nos tecidos. Os sistemas comerciais disponíveis para a dosagem de ferritina plasmática nos laboratórios clínicos, estão baseados em ensaios imunoenzimáticos utilizando anticorpos antiferritina específicos ligados à enzimas. neste trabalho, avaliamos se a metodologia de enzimaimunoensaio com micropartículas (MEIA), do sistema ASXYM - Abbott Laboratories, quantifica adequadamente ferritinas em função do tecido de origem (baço, fígado e coração), e se alguns medicamentos, especialemente de uso prolongado, podem influenciar na metodologia. Os resultados das dosagens de ferritinas teciduais indicaram especificadade e sensibilidade para ferritina de baço (93 a 100%), porém não quantificando adequadamente as ferritinas de fígado (10%) e coração (0%). No estudo de interferência causada por medicamentos (nitrofurantoína, metronidazol, paracetamol, aciclovir e ciprofloxacina), observou-se que em concentrãções específicas de fármaco e proteína ocorre interferência significativa da ciprofloxacina na metodologia e, como consequência, nos resultados.

Roles of phosphate and an enoyl radical in ferritin iron mobilization by 5-aminolevulinic acid.

5-Aminolevulinic acid (ALA), a heme precursor that accumulates in acute intermittent porphyria (AIP) and lead poisoning, undergoes enolization and subsequent iron-catalyzed oxidation at neutral pH. Iron is released from horse spleen ferritin (HoSF) by both ALA-generated O(2)(.-) and enoyl radical (ALA(z.rad)), which amplifies the chain of ALA oxidation (autocatalysis). Iron chelators such as EDTA, ATP, but not citrate, and phosphate accelerate this process and ALA-promoted iron release from HoSF is faster in horse spleen isoferritins containing larger amounts of phosphate in the core. ALA (+0.377 V versus standard hydrogen electrode) is less effective in releasing iron from ferritin than are thioglycollic acid, 6-hydroxydopamine, and N,N,N', N'-tetramethyl-p-phenylenediamine. During electrochemical one electron oxidation of ALA in a nitrogen atmosphere, spin trapping experiments with 3,5-dibromo-4-nitrosobenzenesulfonic acid demonstrated the formation of a spin adduct characterized by a six line signal, indicating a secondary carbon-centered radical and attributed to a resonant ALA&z.rad; radical. Iron is also released in such anaerobic electrochemical oxidations of ALA in the presence of ferritin, suggesting that, in addition to O(2)(*-), ALA&z.rad; can promote iron mobilization from ferritin. Hence, ALA&z.rad; may amplify the metal-catalyzed oxidation of ALA, damaging ALA-accumulating cells and possibly contributing to the symptoms of porphyria.

Iron mobilization by succinylacetone methyl ester in rats. A model study for hereditary tyrosinemia and porphyrias characterized by 5-aminolevulinic acid overload.

Accumulation of 5-aminolevulinic acid (ALA) is an event characteristic of porphyrias that may contribute to their pathological manifestations. To investigate effects of ALA independent of porphyrin accumulation we treated rats with the methyl ester of succinylacetone, an inhibitor of 5-aminolevulinic acid dehydratase that accumulates in the porphyric-like syndrome hereditary tyrosinemia. Acute 2-day treatment of fasted rats with succinylacetone methyl ester (SAME) promoted a 27% increase in plasma ALA. This increase in plasma ALA was accompanied by augmentation of the level of total nonheme iron in liver (37%) and brain (20%). Mobilization of iron was also indicated by 49% increase in plasma iron and a 77% increase in plasma transferrin saturation. Liver responded with a mild (12%) increase in ferritin. Under these acute conditions, some indications of oxidative stress were evident: a 15% increase in liver reactive protein carbonyls, and a 42% increase in brain subcellular membrane TBARS. Brain also showed a 44% increase in CuZnSOD activity, consistent with observations in treatment with ALA. Overall, the data indicate that SAME promotes ALA-driven changes in iron metabolism that could lead to increased production of free radicals. The findings support other evidence that accumulation of ALA in porphyrias and hereditary tyrosinemia may induce iron-dependent biological damage that contributes to neuropathy and hepatoma.

[Perianal manifestations in Crohn's disease]. / Manifestações perianais na doença de Crohn.

UNLABELLED: A total of 114 of 195 patients with Crohn's disease had perianal involvement. The average age at the beginning of symptomatology was 30.3 years. The interval between symptoms and diagnosis was 3.1 years. PAC was associated with colonic disease and in these patients, was multiple. PAC preceded intestinal disease in 11 percent, was coincident in 66 percent and appeared later in 23 percent. Sixty one patients (53.5%) were operated on 104 times (1.7 operations per patient). None of these patients developed faecal incontinence. Two patients were treated with hyperbaric oxygenation. The association of perianal disease and extra-intestinal manifestation occurred in 76 patients. There was no association in 38 patients. Forty patients had extra-intestinal manifestation without perianal disease. Twenty two patients had panproctocolectomy because of perianal disease. Twenty one had a stoma, with or without intestinal resection. The stoma improved perianal symptoms, but all remain defunctioned. After mean follow-up of 8.8 years, 45 patients present some kind of perianal complication. CONCLUSION: the surgical treatment of perianal disease well indicated and performed don't result in incontinence; PAC combined with colonic or rectal disease is associated with higher need of performing a proctocolectomy or a defunctioning stoma. Only 22.8 percent presented resolution of perianal disease maintaining anal sphincter function.

Kleptomania, mood disorder and lithium.

Kleptomania has been found in association with major depression in a fairly large number of reports in recent years. We describe a patient with concurrent DSM-III-R Bipolar Mood Disorder and Kleptomania, whose symptoms remitted completely, apparently in response to lithium therapy, which raised the possibility that pharmacological treatment may benefit kleptomania. Further studies are needed to establish the possible relationship between kleptomania, mood disorders and lithium therapy.