Ovary development in honeybee (Apis Mellifera L.) workers under co2 narcosis, caged outside of the colony

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

Improvement of the physical performance is associated with activation of NO/PGC-l alpha/mtTFA signaling pathway and increased protein expressions of electron transport chain in gastrocnemius muscle from rats supplemented with L-arginine

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

Evolution of the Metazoan Mitochondrial Replicase

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

Spermatozoon ultrastructure and semen parameters of Brycon vermelha (Characiformes, Characidae)

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

Myoglobin from the burrowing reptile Amphisbaena alba: concentrations and functional characteristics

1. 1. Myoglobin from the subterranean reptile Amphisbaena alba was isolated for measurement of concentrations and physico-chemical properties. 2. 2. The concentrations (averaging 12.1 mg.g-1 wet weight in the temporal muscles and 5.8-6.0 in the muscles that motivate the wedge-shaped head which forms the burrowing tool) far exceed those earlier reported for reptiles and other terrestrial vertebrates. 3. 3. The myoglobin has a low O2 affinity compared to mammals (P50 = 2mmHg at 25°C). In the presence of the same myoglobin O2 tension as in mammals this appears to favour similar in vivo O2 saturations at the lower reptilian body temperature. 4. 4. The temperature sensitivity of P50 reflect a heat of oxygenation, ΔH near -13 kcal· mol-1. The myoglobin is monomeric and thus lacks cooperativity in O2 binding and there is no Bohr effect. 5. 5. The pattern of microheterogeneity is similar to that of myoglobin of terrestrial vertebrates but different to aquatic mammals and reptiles. The major and two minor components exhibit very similar O2 affinities. 6. 6. The concentrations and oxygen-binding characteristics of Amphisbaena myoglobin are discussed with regard to the flow of O2 to the mitochondria during digging activity in hypoxic burrow environments. © 1981.

Lipid peroxidation: the role or Ca2+ and protection by calcinine

When calcinine (A-23187) (2 mu M), a known Ca2+ ionophore, is present, a significant protection is observed to a mitochondrial suspension undergoing lipid peroxidation by Fe2+-citrate complex. A-23187 can remove Ca2+, which seems to have an important role in the lipid peroxidation process, from its 'lesive sites' and consequently preventing the damage. This information has importance in terms of knowing the mechanisms and avoiding the damages of lipid peroxidation that occur in some pathological cases such as tumor promotion and hemochromatosis.

Skeletal muscle degeneration and regeneration after injection of bothropstoxin-II, a phospholipase A2 isolated from the venom of the snake Bothrops jararacussu

A myotoxic phospholipase A2, named bothropstoxin II (BthTX-II), was isolated from the venom of the South American snake Bothrops jararacussu and the pathogenesis of myonecrosis induced by this toxin was studied in mice. BthTX-II induced a rapid increase in plasma creatine kinase levels. Histological and ultrastructural observations demonstrate that this toxin affects muscle fibers by first disrupting the integrity of plasma membrane, as delta lesions were the earliest morphological alteration and since the plasma membrane was interrupted or absent in many portions. In agreement with this hypothesis, BthTX-II released peroxidase entrapped in negatively charged multilamellar liposomes and behaved as an amphiphilic protein in charge shift electrophoresis, an indication that its mechanism of action might be based on the interaction and disorganization of plasma membrane phospholipids. Membrane damage was followed by a complex series of morphological alterations in intracellular structures, most of which are probably related to an increase in cytosolic calcium levels. Myofilaments became hypercontracted into dense clumps which alternated with cellular spaces devoid of myofibrillar material. Later on, myofilaments changed to a hyaline appearance with a more uniform distribution. Mitochondria were drastically affected, showing high amplitude swelling, vesiculation of cristae, formation of flocculent densities, and membrane disruption. By 24 hr, abundant polymorphonuclear leucocytes and macrophages were observed in the interstitial space as well as inside necrotic fibers. Muscle regeneration proceeded normally, as abundant myotubes and regenerating myofibers were observed 7 days after BthTX-II injection. By 28 days regenerating fibers had a diameter similar to that of adult muscle fibers, although they presented two distinctive features: central location of nuclei and some fiber splitting. This good regenerative response may be explained by the observation that BthTX-II does not affect blood vessels, nerves, or basal laminae. © 1991.

Brazilian green propolis induced apoptosis in human lung cancer A549 cells through mitochondrial-mediated pathway

Propolis effect on the growth and apoptosis of human lung adenocarcinoma (A549 cells) was investigated as well as its mechanisms. Cells were incubated with propolis for 72 h, and 3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and lactate dehydrogenase assays were employed to assess cell viability and the inhibitory concentration (IC). Apoptosis was detected by Acridine Orange/Ethidium Bromide and 4',6-diamidino-2-phenylindole staining after 24 and 48 h of incubation with ¼ IC50 of propolis by testing the mitochondrial membrane potential (ΔΨm) and the expression of apoptosis-related genes (p53, Caspase-3, Bax, Bcl-2, Bcl-XL , Noxa, Puma and p21) by reverse transcription polymerase chain reaction. Propolis displayed antiproliferative and cytotoxic effects on A549 cells in a dose- and time-dependent manner, but it did not suppress the growth of normal Vero cells. An enhanced apoptosis was seen in A549 propolis-treated cells after 48 h compared with the control cells. Propolis decreased mitochondrial membrane potential by overexpression of pro-apoptotic genes (Bax and Noxa) and reduction of the antiapoptotic gene Bcl-XL . The expression level of other genes remained unchanged (p53, Caspse-3 and Bax), whereas p21 expression was increased. Propolis induced caspase-independent apoptosis through a p53-independent mitochondrial pathway, and cell cycle arrest by upregulation of p21. Although propolis induces apoptosis mainly by p53-independent manner, it may be induced by another pathway, and new insights may arise for preventing or treating lung cancer.

Conformational changes of the HsDHODH N-terminal microdomain via DEER spectroscopy

The human enzyme dihydroorotate dehydrogenase (HsDHODH) has been studied for being a target for development of new antineoplasic and antiproliferative drugs. The synthetic peptide N-t(DH) represents the N-terminal microdomain of this enzyme, responsible for anchoring it to the inner mitochondrial membrane. Also, it is known to harbor quinones that are essential for enzyme catalysis. Here we report structural features of the peptide/membrane interactions obtained by using CD and DEER spectroscopic techniques, both in micelles and in lipid vesicles. The data revealed different peptide conformational states in micelles and liposomes, which could suggest that this microdomain acts in specific regions or areas of the mitochondria, which can be related with the control of the quinone access to the HsDHODH active site. This is the first study to report on conformational changes of the HsDHODH N-terminal microdomain through a combination of CD and DEER spectroscopic techniques.

In vitro embryos production after oocytes treatment with forskolin

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

Cytotoxic effects of neem oil in the midgut of the predator Ceraeochrysa claveri

Studies of morphological and ultrastructural alterations in target organs have been useful for evaluating the sublethal effects of biopesticides regarded as safe for non-target organisms in ecotoxicological analyses. One of the most widely used biopesticides is neem oil, and its safety and compatibility with natural enemies have been further clarified through bioassays performed to analyze the effects of indirect exposure by the intake of poisoned prey. Thus, this study examined the cellular response of midgut epithelial cells of the adult lacewing, Ceraeochrysa claveri, to neem oil exposure via intake of neem oil-contaminated prey during the larval stage. C. claveri larvae were fed Diatraea saccharalis eggs treated with neem oil at concentrations of 0.5%, 1% and 2% throughout the larval stage. The adult females obtained from these treatments were used at two ages (newly emerged and at the start of oviposition) in morphological and ultrastructural analyses. Neem oil was found to cause pronounced cytotoxic effects in the adult midgut, such as cell dilation, emission of cytoplasmic protrusions, cell lysis, loss of integrity of the cell cortex, dilation of cisternae of the rough endoplasmic reticulum, swollen mitochondria, vesiculated appearance of the Golgi complex and dilated invaginations of the basal labyrinth. Epithelial cells responded to those injuries with various cytoprotective and detoxification mechanisms, including increases in cell proliferation, the number of calcium-containing cytoplasmic granules, and HSP 70 expression, autophagic processes and the development of smooth endoplasmic reticulum, but these mechanisms were insufficient for recovery from all of the cellular damage to the midgut. This study demonstrates that neem oil exposure impairs the midgut by causing sublethal effects that may affect the physiological functions of this organ, indicating the importance of studies of different life stages of this species and similar species to evaluate the safe and compatible integrated use of biopesticides.

Diferenciação gonadal em Piaractus mesopotamicus

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Cellular vacuolation and mitochondrial-associated factors induced by Clostridium perfringens epsilon toxin detected using acoustic flow cytometry

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

In Vitro Safety Evaluation of Caffeic Acid

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