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Instituto de Biologia Unicamp






ABSTRACTA IB (2) - 1999


P020-99 RNA relocation at mitosis in transformed and tumorigenic human breast epithelial cells

Mello MLS*, Barbisan LF, Russo J, Vidal BC

The fate of RNA at mitosis was followed cytochemically in human breast epithelial cells transformed by benzo[a]pyrene and transfected with the c-Ha-ras oncogene. RNA relocation in association with the mitotic spindle fibers was observed from metaphase to telophase not to vary in all the cell lines studied. RNA-containing nucleolus-like bodies persistent during mitosis were found to decrease in frequency in the transformed and tumorigenic cells in comparison with control non-transformed cells simultaneously to the previously reported increase in nucleolar areas for the same cell types while in interphase. It is suggested that an improved use of RNA transcripts has been developed with cell transformation and tumorigenesis in this model.
Cell Biology International 23: 125-128, 1999 IF= 1.124

P021-99 Apoptosis and catastrophic cell death in benzo[a]pyrene-transformed human breast epithelial cells

Barbisan LF, Mello MLS*, Russo J, Vidal BC

Apoptosis and mitotic death, bi- and multinucleation, giant cells and micronucleation were investigated in human breast epithelial cell lines transformed by benzo[a]pyrene (BP)(BP1, BP1-E and BP1-E1 cells) and in BP1 cells transfected with the c-Ha-ras oncogene (BP1-Tras cells). Since BP induces apoptosis and the abnormal expression of ras genes elicits catastrophic mitosis, both phenomena were expected to occur in this system, especially in BP1-Tras cells. However they were found in all cells though more frequently in BP1-Tras cells. The abnormal expression of Ha-ras in BP1-Tras cells may enhance in this system the effects of the BP apoptosis path reported for BP-transformed Hepa 1c1c7 hepatoma cells. Transfection with the ras oncogene also enhanced the mitotic disturbances producing multi- and micronucleation and mitotic death, possibly because of the genome instability promoted by this oncogene in the BP-transformed cell line. Mutation Research 431: 133-139, 1999 IF= 1.754

P022-99 Two karyotypes and heteromorphic sex chromosomes in Physalaemus petersi (Leptodactylidae, Anura)

Lourenço LB*, Recco-Pimentel SM*, Cardoso AJ

Cytogenetic analyses were performed on specimens from two populations of Physalaemus petersi from three locations in Brazilian West Amazon. All animals studied showed a full chromosome complement of 2n=22, but two distinct karyotypes (I and II) were detected among specimens from one of the populations. Karyotype I specimens showed an XX/XY sex chromosome system and C-band polymorphism. Karyotype II was observed in males whose call differed from other males of the same population, suggesting that a re-evaluation of the taxon Physalaemus petersi may be necessary. The rate of karyological evolution in these populations is suggested to be greater than that of anatomical evolution. Canadian Journal of Zoology 77: 624-631, 1999 IF= 0.975

P023-99 An ultrastuctural study of spermiogenesis in three species of Pysalaemus (Anura, Leptodactylidae)

Amaral MJLV, Fernandes AP, Báo SN, Recco-Pimentel SM*

Ultrastructural aspects of spermiogenesis and testicular spermatozoa of three anuran amphibians, Physalaemus biligonigerus, P. fuscomaculatus and P. gracilis, were investigated by electron microscopy. The nuclei, middle pieces and tails of the three species were similar. In all cases, the nuclei were elongated and the acrosome consisted of a cone-shaped cap. The connecting pieces located in the flagellum implantation zone had transverse striations. The tails had a 9+2 axial filament pattern, a juxtaxonemal fiber and an undulating membrane. In contrast to other Leptodactylidae spermatozoa, no axial rod was observed in these Physalaemus species.
Biocell, 23 (3), 1999 IF= 0.264

P024-99 Paracrystalline structures in the epithelial principal cells of the epididymis of water buffalo (Bubalus bubalis)

Santos JN, Dolder H*

The ultrastructure of many Principal cells in the cauda epididymis of water buffaloes with ages of 4, 18, 24, 30 and 36 months, revealed long, curved paracrystalline structures that are quite large and frequently encountered in the cytoplasm, usually near the nucleus. Concomitantly or not, smaller rod-like, hexagonal or curled structures can be found in the nucleus. Both structures, cytoplasmic and intranuclear, are made up of a sheath of parallel filaments. These paracrystals may appear as thin, regularly spaced filaments that are associated with fine, evenly spaced subunits. Both structures may represent stored enzymes or substances present in the intraluminal fluid, which are absorbed and initially stored in numerous intraepithelial vacuoles of the corpus and cauda of the buffalo epididymis. Tissue and Cell 31: 335-341, 1999. IF= 1.000

P025-99 Effects of an essential oil from the bark of Croton cajucara Benth. on experimental gastric ulcer models in rats and mice

Hiruma-Lima CA., Gracioso JS, Nunes DS, Souza Brito ARM*

Croton cajucara Benth is widely used in Amazonian folk medicine for the treatment of a wide range of gastrointestinal symptoms. The essential oil (EO) from the bark of C. cajucara was investigated for acute toxicity in mice and for its ability to prevent the formation of ulceration of the gastric mucosa in different models of experimentally induced gastric ulcer in mice and rats. When previously administered at the dose of 100 mg kg-1, the EO significantly reduced the gastric injury induced by hypothermic restraint stress (48%), indomethacin (47%), ethanol (86%) and pylorus ligature models (87%) in rats. In the HCl/ethanol-induced gastric ulcer model in mice, at oral doses of 100 and 200 mg kg -1, the EO significantly reduced the formation of gastric lesions by 52% and 76%, respectively. In rats submitted to pylorus ligature, the EO (p.o.) increased the volume of gastric juice but no significant modifications where found in gastric parameters such as pH and total acid content. However, an increase in volume and a decrease in gastric acidity were observed when the EO (100 mg kg-1) was previously administered intraduodenally to mice. The LD50 values in mice were 9.3 g kg-1 by the oral route and 680 mg kg-1 by the intraperitoneal route. The good yield of essential oil obtained from dried C. cajucara bark (1%) as well as its antiulcerogenic activity and low toxicity suggest pharmacological studies of this substance as a potential new antiulcerogenic drug. Journal of Pharmacy and Pharmaco1ogy 51: 341-346, 1999 IF= 0.771

P026-99 Antiulcerogenic mechanisms of dehydrocrotonin, a diterpenelactone obtained from Croton cajucara Benth

Hiruma-Lima CA, Spadari--Bratfisch RC, Grassi Kassisse DM, Souza Brito ARM*

The bark of Croton cajucara Benth. is used in Brazilian folk medicine as an infusion to treat gastrointestinal disorders. The mechanisms involved in the antiulcerogenic activity of dehydrocrotonin (DHC) were studied. DHC (100 mg/kg) did not induce any alteration in gastric volume in Shay mice but modified the pH and total acid concentration of gastric juice. Incubation of gastric juice with DHC did not reduce gastric acidity. The concentration-response curves for the chronotropic effect of histamine in guinea pigs right atria were shifted to the right, with a significant decrease in maximum response, in the presence of DHC. Similar results were obtained with DHC (30 m M) for the concentration-response curves to carbachol in the isolated rat stomach. DHC induced a significant increase in PGE2 production in rat stomach mucous cells. Oral administration of DHC (100 mg/kg per day) for 14 consecutive days had no effect on the healing of acetic acid-induced gastric ulcer in rats. The protective effect of DHC on induced gastric lesions may be due to synergistic effects, e.g., an increase in PGE2 release and non-competitive antagonism of H2- receptors and of muscarinic receptors. While the former result represents an increase in the protective factors, the latter one shows a decrease in the aggressive factors against the gastric mucosa. Planta Medica 65: 325-330, 1999 IF= 1.430

P027-99 Petiveria alliacea extract protects mice against Listeria monocytogenes infections - effects on bone marrow progenitor cells

Quadros MR, Souza Brito ARM*, Queiroz ML

The effects of Petiveria alliacea, a Brazilian medicinal plant, on the hematopoietic response of mice infected with Listeria monocytogenes were studied. A protective effect of the crude extract of P. alliacea was found, since the survival of the treated/infected was higher than that in the infected group. Moreover, the number of granulocyte/macrophage colonies (CFU-GM) and the serum colony stimulating activity levels were increased in the treated/infected mice in relation to the infected group. Immunomodulation of P. alliacea on hematopoiesis may be at least in part responsible for the increased resistence of mice to Listeria monocytogenes infection. Immunopharm. Immunoterapy 21: 109-124, 1999 IF= 0.506

P028-99 Antiulcerogenic mechanisms of a Dalbergia monetaria L. Iyophilized aqueous extract

Cota RHS, Spadari-Bratfisch RC, Grassi Kassisse DM, Souza Brito ARM*

The decoction of Dalbergia monetaria L. is popularly used in Brazil for the treatment of gastric ulcer. We have reported a significant antiulcerogenic activity for D. monetaria lyophilized aqueous extract (LAE) on the gastric ulcer lesions induced by pylorus-ligature, ethanol and hypothermic-restraint stress. Since many biologically active compounds have been isolated from the LAE of D. monetaria, the identification of the antiulcerogenic mechanisms of action of this extract was conducted here. LAE increased gastric mucosal PGE2 synthesis in rat stomach mucous cells and decreased the total acid content of gastric juice without alterations in pH or gastric volume, in Shay rats. Dose-response curves to histamine were shifted to the right in guinea-pig isolated right atria, with a significant decrease in maximum response. However, the same effect was observed when the agonist was isoprenaline. LAE did not induce any alteration in the dose-response curve to carbachol in rat fundus strips. Thus, the protective effect of LAE on induced gastric lesions may be due to synergistic effects, e.g., an increase of PGE2 synthesis and an antagonism of H2-histamine and b -adrenergic receptors, decreasing acid gastric secretion. While the former represents an increase of the protective factors, the latter shows a decrease of the aggressive factors against the gastric mucosa. Journal of Pharmacy and Pharmacology 51: 735-740, 1999 IF= 0.771

P029-99 Determination of the geometrical diarylpropenamine isomers in feces by high-performance liquid chromatography

Pereira DG, Souza Brito ARM*, Duran M

Since diarylpropenamine derivatives are potential drugs for the treatment of Chagas disease, a specific and reproducible HPLC method for the determination of cis- and trans-isomers of the unsubstituted derivative, 3-(4'-bromo-[1,1'-biphenyl]-4-yl)-3-(4-X-phenyl-N,N-dimethyl-2-propen-1-amine (I, where X=H) was studied in feces. The analyte I and internal standard, nitro derivative (II, where X=NO2), were isolated from the basified biological matrix using a liquid-liquid extraction. The analytes were eluted with ethyl acetate-hexane-triethylamine (59:40:1) in HPLC column (silica) and detected by UV spectrophotometry at 272 nm. The method has been applied to analyses of feces samples from rats dosed with I, in which fecal excretion is quantitatively the major route for I elimination. Journal of Chromatography 728: 117-123, 1999 IF= 1.588


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