Continuous ethanol production in a nonconventional five-stage system operating with yeast cell recycling at elevated temperatures

Three ranges of increasing temperatures (35-43, 37-45, 39-47degreesC) were sequentially applied to a five-stage system continuously operated with cell recycling so that differences of 2degreesC (between one reactor to the next) and 8degreesC (between the first reactor at the highest temperature and the fifth at the lowest temperature) were kept among the reactors for each temperature range. The entire system was fed through the first reactor. The lowest values of biomass and viability were obtained for reactor R-3 located in the middle of the system. The highest yield of biomass was obtained in the effluent when the system was operated at 35-43degreesC. This nonconventional system was set up to simulate the local fluctuations in temperature and nutrient concentrations that occur in different regions of the medium in an industrial bioreactor for fuel ethanol production mainly in tropical climates. Minimized cell death and continuous sugar utilization were observed at temperatures normally considered too high for Saccharomyces cerevisiae fermentations.

Alkaloids extracted from Pterogyne nitens induce apoptosis in malignant breast cell line

In the present study, two alkaloids isolated from Pterogyne nitens, a plant native to Brazil, have been shown to induce apoptosis in human breast cancer cells. These compounds, pterogynine (PGN) and pterogynidine (PGD), were tested for their effect on a human infiltrating ductal carcinoma cell line (ZR-7531). The cell line was treated with each alkaloid at several concentrations. Time-dependence (with or without recuperation time) and concentration-dependence (in the range 0.25-10 mM) were investigated in cytotoxicity and apoptosis assays. The annexin assay indicated an apparently higher percentage of death by necrosis of malignant cells after 24 h exposure to both P. nitens extracts than the Hoechst assay. Thus, our results in the two tests demonstrated that the Hoechst assay can discriminate between late apoptotic cells and necrosis, whereas the flow cytometry-based annexin V assay cannot. We concluded that PGN and PGD have effective antineoplastic activity against human breast cancer cells in vitro, by inducing programmed cell death.

Expression of apoptotic and cell proliferation regulatory proteins in keratoacanthomas and squamous cell carcinomas of the skin

The aim of this study was to investigate the expression of p53, caspase-3, bcl-2, MIB-1, and PCNA to validate more objective methods to differentiate squamous cell carcinoma and keratoacanthoma, as well as to understand their pathogenesis with accuracy. A total of 52 cases of histopathologically diagnosed keratoacanthoma in the proliferative stage and 56 cases of well-differentiated squamous cell carcinoma were selected in this study. The expression was evaluated by means of immunohistochemistry. Bcl-2 immunoreactivity was weak or absent in the majority of cases, either in squamous cell carcinoma or in keratoacanthoma. PCNA-positive cells did not show differences between two lesions evaluated. on the other hand, MIB-1 was statistically significant (p<0.05) between squamous cell carcinomas and keratoacanthomas. Moreover, p53 and caspase-3 were overexpressed in squamous cell carcinomas. Together, these results suggest that the biological behavior of the well-differentiated squanous cell carcinomas of the skin may be associated with cellular proliferation and/or deregulation of cell death, indicated by increased expression of the MIB-1 and apoptotic proteins p53 and caspase-3, respectively. (C) 2007 Elsevier GrnbH. All rights reserved.

Cell cycle arrest and apoptosis in TP53 subtypes of bladder carcinoma cell lines treated with cisplatin and gemcitabine

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

Expression of genes related to apoptosis, cell cycle and signaling pathways are independent of TP53 status in urinary bladder cancer cells

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

Photodynamic therapy associating Photogem (R) and blue LED on L929 and MDPC-23 cell culture

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

Differentiation of the worker's ovary in Apis mellifera L. (Hymenoptera, Apidae) during life of the larvae

The aim of the present study is to characterize the way worker and queen ovaries differentiate in, Apis mellifera, a species with trophic determination of female castes. A morphological study carried out with light and transmission electron microscopy showed that the differences in ovary development between the two castes begin as soon as the differential nursing of larvae is initiated. The decrease in ovariole number in worker ovaries is due to a process of cell death occurring in germinative cells and autophagic regression of somatic cells in the ovarioles that commence in the third instar larvae and proceed until the fifth instar where the process is more intense. Germinative cell death leads to ovariole disintegration and incorporation of the remaining somatic cells of the latter into the stromatic cells in such a way that the total volume of the ovary is little affected during larval development, although the ovariole number decreases. By the end of the larval stage, loss of cells is observed among the stromatic cells of the ovary. As a result, the ovary starts to decrease in volume and takes on the adult form.

Cytotoxicity of fipronil on mice liver cells

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

Morphological alterations induced by boric acid and fipronil in the midgut of worker honeybee (Apis mellifera L.) larvae

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Death by apoptosis in salivary glands of females of the tick Rhipicephalus sanguineus (Latreille, 1806) (Acari : Ixodidae)

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

Differences in mushroom bodies morphogenesis in workers, queens and drones of Apis mellifera: Neuroblasts proliferation and death

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

Cytotoxicity of water-soluble fraction from biodiesel and its diesel blends to human cell lines

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

Cimetidine-induced vascular cell apoptosis impairs testicular microvasculature in adult rats

Cimetidine, an H2 receptor antagonist used for treatment of gastric ulcers, exerts antiandrogenic and antiangiogenic effects. In the testes cimetidine impairs spermatogenesis, Sertoli cells and peritubular tissue, inducing apoptosis in the myoid cells. Regarding the importance of histamine and androgens for vascular maintenance, the effect of cimetidine on the structural integrity of the testicular vasculature was evaluated. Adult male rats received cimetidine (CMTG) and saline (CG) for 50 days. The testes were fixed in buffered 4% formaldehyde and embedded in historesin and paraffin. In the PAS-stained sections, the microvascular density (MVD) and the vascular luminal area (VLA) were obtained. TUNEL method was performed for detection of cell death. Testicular fragments embedded in Araldite were analyzed under transmission electron microscopy. A significant decrease in the MVD and VLA and a high number of collapsed blood vessel profiles were observed in CMTG. Endothelial cells and vascular muscle cells were TUNEL-positive and showed ultrastructural features of apoptosis. These results indicate that cimetidine induces apoptosis in vascular cells, leading to testicular vascular atrophy. A possible antagonist effect of cimetidine on the H2 receptors and/or androgen receptors in the vascular cells may be responsible for the impairment of the testicular microvasculature.

Effects of sublethal doses of imidacloprid in malpighian tubules of africanized Apis mellifera (Hymenoptera, Apidae)

In Brazil, imidacloprid is a widely used insecticide on agriculture and can harm bees, which are important pollinators. The active ingredient imidacloprid has action on the nervous system of the insects. However, little has been studied about the actions of the insecticide on nontarget organs of insects, such as the Malpighian tubules that make up the excretory and osmoregulatory system. Hence, in this study, we evaluated the effects of chronic exposure to sublethal doses of imidacloprid in Malpighian tubules of Africanized Apis mellifera. In the tubules of treated bees, we found an increase in the number of cells with picnotic nuclei, the lost of part of the cell into the lumen, and a homogenization of coloring cytoplasm. Furthermore, we observed the presence of cytoplasmic vacuolization. We confirmed the increased occurrence of picnotic nuclei by using the Feulgan reaction, which showed the chromatin compaction was more intense in the tubules of bees exposed to the insecticide. We observed an intensification of the staining of the nucleus with Xylidine Ponceau, further verifying the cytoplasmic negative regions that may indicate autophagic activity. Additionally, immunocytochemistry experiments showed TUNEL positive nuclei in exposed bees, implicating increased cell apoptosis after chronic imidacloprid exposure. In conclusion, our results indicate that very low concentrations of imidacloprid lead to cytotoxic activity in the Malpighian tubules of exposed bees at all tested times for exposure and imply that this insecticide can alter honey bee physiology. © 2013 Wiley Periodicals, Inc.

Estudo morfológico comparativo das glândulas salivares de fêmeas de carrapatos Rhipicephalus (Boophilus) microplus (Canestrini, 1887) (Acari: Ixodidae) em dois estágios de alimentação

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)