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We investigated whether intrastriatal (i.s.) administration of 5-aminolevulinic acid (ALA) induces oxidative damage and whether behavioral alterations induced by i.s. administration of ALA could be affected by antioxidants. Unilateral injection of ALA (6 micromol/striatum) increased (approximately 30%) thiobarbituric acid-reactive substances (TBARS), but did not affect striatal content of total thiol groups. ALA-induced body asymmetry was not prevented by pretreatment with ascorbic acid (100 mg/kg, s.c.), dimethyl sulfoxide (DMSO, 0.5 microl/striatum, i.s.) or ebselen (10 nmol/striatum, i.s.). ALA-induced convulsions were not prevented by ascorbic acid, but were partially prevented by DMSO and completely prevented by ebselen. Ebselen completely prevented the increase of striatal TBARS induced by ALA. Results obtained suggest the involvement of reactive species in ALA-induced convulsions and may be of value in understanding the physiopathology of neurological dysfunctions associated to ALA overload.

As porfirias são causadas por deficiência parcial de uma das enzimas da via de biossíntese do heme, caracterizando-se por disfunções neuroviscerais bastante semelhantes. As porfirias agudas são decorrentes da deficiência das enzimas deltaaminolevulinato desidratase (ALAD), porfobilinogênio desaminase, coproporfirinogênio oxidase ou protoporfirinogênio oxidase, que provocam, respectivamente, porfiria por deficiência da ALAD, porfiria aguda intermitente, coproporfiria hereditária e porfiria variegada. Todas as porfirias agudas caracterizam-se por um aumento na concentração de ácido 5-aminolevulínico no plasma e no líquor, acompanhado de um aumento na excreção urinária deste composto. Dependendo do tipo de porfiria aguda que acomete o paciente, podem ser observados ainda aumentos na excreção urinária de outros precursores porfirínicos e mesmo de porfirinas. Os casos de porfirias agudas podem ser detectados pela dosagem de porfirinas e seus precursores na urina, sangue e fezes. A triagem das famílias portadoras é importante para detectar casos latentes, pois a expressão clínica da doença geralmente está ligada a fatores ambientais ou adquiridos que provocam os ataques agudos. A identificação de portadores pode ser realizada através da determinação da atividade das enzimas da via de biossíntese do heme no sangue e mais recentemente através da análise do DNA.

O livro "A importância do selênio para a agropecuária e saúde humana" procura apresentar alguns aspectos relacionados às funções que o selênio pode desempenhar em animais e humanos.

Although sonication treatment increases the amount of protein extracted from rumen bacteria adhered to the residue of incubation, the CMCase activity of the released protein might be measured without sonication treatment and should be carried out with a hypotonic buffer solution that includes a calcium source. When pH is not a treatment factor, the buffer pH should be between 5.5 and 6.

EditorialSince early in courses of biological sciences studies are presented to the chair of biochemistry. Then, they can recognize an important function what mitochondria develop in living animal cells: convert electrical power generated in cells by the oxidation of foods into chemical energy, e.g., adenosine triphosphate (ATP). Likewise, in vegetal cells chloroplasts convert radiant energy, in the form of photons, to generate an electric power and, thereby, to produce chemical energy: ATP and reductive power (e.g., NADPH). Soon, they can understand that the two processes, i.e., cellular respiration in animal cells and photosynthesis in vegetal tissues, depend one on another and together comprises the carbon cycle. It is a very simple concept at cellular and molecular levels, and a very primordial process in the terrestrial atmosphere at a macroscopic scale.Until second half of last century all appeared normal in the Earth's atmosphere, but today we are observing some signals of an imbalance in as primordial and simple mechanism: solar irradiation overtakes terrestrial capacity to dissipate heat and our atmosphere is warming. An excess of CO 2 was emitted to atmosphere without a compensatory fixation by photosynthesis. Two pivotal processes compete for this effect: firing of fossil fuels (a lot) and "the pioneer effect" (deforestation and new uses of earths).Therefore, nowadays we need to look out of cells, around ourselves, and to think about and to nurse our world, i.e., our green house. It is attempter to study mitochondria, chloroplasts, biomembranes/lipid bilayers, porins, membrane receptors, ionic channels, calcium homeostasis, apoptosis/necrosis, mitochondrial membrane potential, mitochondrial transition pores, futile cycles, heat generation, uncoupler protein, photons, water-lyses molecule centers, photosynthetic complexes, types of chlorophylls, and many others wonderful findings which were reported during last decades in the field of science. However, they will are, maybe, less useful if in the future, for example at middle of the 21 th century, temperature of atmosphere up to 1.5-2.0 degree regard levels before industrialization due double up in CO 2 concentration; or if it will be reached 4 × CO 2 levels in the atmosphere at end of the 21 th century. The biggest of all cells is sick because we went not able to produce, transfer and convert energy in our green house. We went unable to manage intelligently energetic flow in the biosphere and lead it to an unbalance. For alleviating such process we have not air-conditioning systems with power enough to cool this warming. Hence, we went good scientists concerning molecular and basic science, but bad energy transducers in the natural environment, and showed little capability to handle energy in our labor/economical activities. Unfortunately, this difficulty seems to be a hard and painful lesson out of the academic chairs for the mankind. Thus, we proof to be good theorists in the research, but unable biochemists in the life!