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ANNIE JOUBERT^1*, HERMIA VAN ZYL¹, JOHANNES LAURENS², MONA-LIZA LOTTERING¹
BIOCELL, Vol.33, No.3, pp. 137-140, 2009, DOI:10.32604/biocell.2009.33.137
Abstract C2- and C4-position 17β-estradiol metabolites play an important role in breast carcinogenesis. 2-Hydroxyestradiol and 4-hydroxyestradiol are implicated in tumorigenesis via two pathways. These pathways entail increased cell proliferation and the formation of reactive oxygen species that trigger an increase in the likelihood of deoxyribonucleic acid mutations.
2-Methoxyestradiol, a 17β-estradiol metabolite, however, causes induction of apoptosis in transformed and tumor cells; thus exhibiting an antiproliferative effect on tumor growth. The 4-hydroxyestradiol:2- methoxyestradiol and 2-hydroxyestradiol:2-methoxyestradiolratios therefore ought to be taken into account as possible indicators of carcinogenesis. More >

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MARIA TERESA MARTIN^2*, HILDA PEDRANZANI³, PATRICIA GARCÍA-MOLINERO², VALENTIN PANDO⁴, ROSARIO SIERRA-DE-GRADO¹
BIOCELL, Vol.33, No.3, pp. 141-148, 2009, DOI:10.32604/biocell.2009.33.141
Abstract Two independent parameters, epicotyl height (cm) and number of induced buds were studied on Pinus pinaster explants to analyse the effects of three phytohormones (6-benzylaminopurine, jasmonic acid, ethylene) which were combined or not in 11 different treatments. Epicotyle length diminished significantly in relation to the control medium (medium without exogen phytohormones) in presence of jasmonic acid, 6-benzylaminopurine or Ethephon (which is converted to ethylene in plants) in any of treatments. Concentrations of 100 μM of jasmonic acid and Ethephon had a greater inhibitory effect than the treatments with 10 μM. In addition to that, jasmonic acid was a stronger inhibitor… More >

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JORGE R. RONDEROS
BIOCELL, Vol.33, No.3, pp. 149-154, 2009, DOI:10.32604/biocell.2009.33.149
Abstract Triatoma infestans, a blood-feeding insect, synchronises physiological mechanisms leading to moult with food intake. Since the corpora allata are important in moult and metamorphosis regulation, we have studied morphological changes in 4^th instar nymphs (gland size, cell density, percent of animals showing mitoses and cell size). Changes were correlated with the effect of precocene II, epidermal proliferation, and with the extent of the “head critical period”. Based on morphological grounds, three stages can be defined in the gland along the 4^th instar: Stage 1 (days 0-2 after feeding) showed small corpora allata, composed by a small number of cells, and… More >

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TARSILA MARIA DA SILVA MORAES¹, CLAUDIA FRANCA BARROS², SEBASTIÃO JOSÉ DA SILVA NETO³, VALDIRENE MOREIRA GOMES⁴, MAURA DA CUNHA^1*
BIOCELL, Vol.33, No.3, pp. 155-165, 2009, DOI:10.32604/biocell.2009.33.155
Abstract Simira is a predominantly woody Neotropical genus comprising 41 taxa, 16 of which occur in Brazil and eight of them in the southeastern region of Brazil. Leaf blades of Simira eliezeriana Peixoto, S. glaziovii (K. Schum.) Steyerm., S. grazielae Peixoto, S. pikia (K. Schum.) Steyerm., S. rubra (Mart.) Steyerm., S. sampaioana (Standl.) Steyerm. were collected in the southeastern region of Brazil and fixed according to usual methods for light and electron microscopy. The leaf blades show typical characteristics of the Rubiaceae family as dorsiventral mesophyll and paracytic stomata. The presence of two bundle sheaths that extend to the upper epidermal… More >

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GABRIEL MARTIN ALVAREZ^1*, GABRIEL CARLOS DALVIT¹, MARÍA VERÓNICA ACHI¹, MARCELO SERGIO MIGUEZ², PABLO DANIEL CETICA¹
BIOCELL, Vol.33, No.3, pp. 167-177, 2009, DOI:10.32604/biocell.2009.33.167
Abstract Porcine immature oocyte quality (i.e., that of live oocytes at the germinal vesicle stage) was evaluated according to features of the surrounding cumulus, aiming to establish maturational competence of different subpopulations of such cumulus-oocyte complexes. Six subpopulations were identified: A₁ (with a dense cumulus), A₂ (with a translucent cumulus), B₁ (with the corona radiata), B₂ (partly naked oocytes), C (naked oocytes), D (with a dark cumulus). The percent incidence of live oocyte in these subpopulations changed significantly as related to cumulus features, however the occurrence of oocytes in the germinal vesicle stage was lower in class D only. Similar metaphase… More >

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MARÍA LAURA FONTANA, LUIS AMADO MROGINSKI, HEBE YOLANDA REY*
BIOCELL, Vol.33, No.3, pp. 179-186, 2009, DOI:10.32604/biocell.2009.33.179
Abstract With the aim of developing an efficient plant regeneration protocol, leaflet explants of three accessions of Arachis villosa Benth. (S2866, S2867 and L97) were cultured on basic Murashige and Skoog medium supplemented with different combinations of plant growth regulators: α-naphthalenacetic acid, indole-3-butyric acid, 6-benzylaminopurine, kinetin and thidiazuron. The accession L97 was the only one able to differentiate buds through indirect organogenesis. The most suitable combination for bud regeneration was the basic medium added with 13.62 μM thidiazuron and 4.44 μM 6-benzylaminopurine. These results show the important role of the genotype in morphogenetic responses and the organogenetic effect of thidiazuron in… More >

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VIRGINIA VILLALOBOS¹, ERNESTO BONILLA^2,4,*, ALAN CASTELLANO³, ERNESTO NOVO¹, RALPH CASPERSEN⁴, DEBORA GIRALDOTH¹, SHIRLEY MEDINA-LEENDERTZ⁴
BIOCELL, Vol.33, No.3, pp. 187-197, 2009, DOI:10.32604/biocell.2009.33.187
Abstract The effect of manganese toxicity on the ultrastructure of the olfactory bulb was evaluated. Male albino mice were injected intraperitoneally with MnCl₂ (5 mg/Kg/day) five days per week during nine weeks. The control group received NaCl (0.9%). The olfactory bulbs of five mice from each group were processed for transmission electron microscopy after 2, 4, 6 and 9 weeks of manganese treatment. On week 2, some disorganization of the myelin sheaths was observed. After 4 weeks, degenerated neurons with dilated cisternae of rough endoplasmic reticulum and swollen mitochondria appeared. A certain degree of gliosis with a predominance of astrocytes with… More >

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