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 >

Brevedan¹ RE, MI Aveldaño², MN Fioretti¹, MA Varillas², SS Baioni¹, HR Mirassón³, IR Palomo¹

Phyton-International Journal of Experimental Botany, Vol.78, pp. 49-52, 2009, DOI:10.32604/phyton.2009.78.049

Abstract Two experiments were conducted under greenhouse conditions to study the influence of P deficiency on nitrogen nutrition of non-nodulated soybean. There was a reduction of N and P content in P deficient (P-) plants of almost 50% after 50 days. During this period, dry matter of these plants was reduced by 33%. Nitrate reductase activity and shoot nitrate content were lower in Pthan in P+ plants. Seventy five percent of nitrates in P- plants were in the roots. Nitrate accumulation in roots would be due to the lower nitrate reductase activity in this organ and More >

Sánchez E¹, G Ávila-Quezada¹, AA Gardea¹, E Muñoz¹, JM Ruiz², L Romero²

Phyton-International Journal of Experimental Botany, Vol.78, pp. 11-16, 2009, DOI:10.32604/phyton.2009.78.011

Abstract The objective of this work was to determine the effect of different P doses on nitrogen assimilation in roots and leaves of green beans plants (Phaseolus vulgaris L. cv. Strike). Phosphorus was applied in the nutrient solution as H₃PO₄, at the nutrient doses of: P1 = 0.40 mM; P2 = 0.80 mM; P3 = 1.60 mM; P4 = 3.20 mM; P5 = 4.80 mM, and P6 = 6.40 mM P. Our results indicate that both P toxicity and deficiency gave similar responses to N assimilation. Phosphorus and NO3 - interacted on the absorption and translocation processes affecting More >

Yanan Wang^∗, Qing-Hua Qin^∗, Shankar Kalyanasundaram^∗

Molecular & Cellular Biomechanics, Vol.6, No.2, pp. 101-112, 2009, DOI:10.3970/mcb.2009.006.101

Abstract A mathematical model is developed for simulating anabolic behaviour of bone affected by Parathyroid Hormone (PTH) in this paper. The model incorporates a new understanding on the interaction of PTH and other factors with the RANK-RANKL-OPG pathway into bone remodelling, which is able to simulate anabolic actions of bone induced by PTH at cellular level. The RANK-RANKL-OPG pathway together with the dual action of TGF-$\beta$, which represent the core of coupling behaviour between osteoblasts and osteoclasts which are two cell types specialising in the maintenance of bone integrity, are widely considered essential for the regulation… More >

JIANLI SHI, WENYAN MEI, JING YANG

BIOCELL, Vol.32, No.3, pp. 259-263, 2008, DOI:10.32604/biocell.2008.32.259

Abstract As the key component of many hemoproteins (heme-containing proteins), heme is involved in a broad range of biological processes. Enzymes required for heme biosynthesis and degradation pathways are evolutionarily conserved. While heme metabolism has been studied extensively, the expression of heme metabolism enzymes during development has not been described. Here, we report that all heme biosynthases and two heme oxygenases, which initiate heme degradation, are dynamically expressed during Xenopus embryonic development. All heme synthases, with the exception of aminolevulinic acid synthase 2, are maternally expressed. At neurula stage, heme synthases are expressed in the developing neural… More >

Sánchez E¹, G Ávila-Quezada¹, AA Gardea¹, JM Ruiz², L Romero²

Phyton-International Journal of Experimental Botany, Vol.76, pp. 143-152, 2007, DOI:10.32604/phyton.2007.76.143

Abstract The objective of this work was to determine the effect of deficiency versus toxicity of N on biosynthesis of proline in fruits of green bean plants (Phaseolus vulgaris L. cv. Strike). Nitrogen was applied to the nutritive solution in the form of NH₄NO₃ at 1.5 mM (N1), 3.0 mM (N2), 6.0 mM (N3, optimal level), 12.0 mM (N4), 18.0 mM (N5), and 24.0 mM (N6). Nitrogen deficiency (N1 and N2) was characterized by having lower proline accumulation in pods and seeds, mainly because proline degradation was stimulated by the enzyme proline dehydrogenase. On the other hand, N More >