Study of the action of tamoxifen on the mammary gland epithelium of premenopausal patients by lysosome quantification

Tamoxifen is an antiestrogen drug widely utilized for the adjuvant hormonal treatment of breast carcinoma. Its use in the primary prophylaxis of this disease is currently being proposed. Although the drug has few side effects, its precise action on breast tissue that has not undergone neoplastic transformation has not been fully elucidated. This prospective, randomized study assessed the estrogen activity of tamoxifen on the mammary gland epithelium of premenopausal patients using a quantitative analysis of mammary epithelium lysosome identified by the cytochemical technique of GOMORI for acid phosphatase and by light microscopy. Tamoxifen significantly increased the number of lysosomes only during the secretory phase of the menstrual cycle. We concluded that the early effect of the drug on normal mammary tissue is synergistic with the effect of estrogen during the premenopausal period.     

Effect of lead on the uptake of nutrients by unicellular algae

From batch growth experiments carried out with the alga Selenastrum capricornutum Printz the evolution of uptake of nitrogen and phosphorus with time in the absence and presence of lead 1 × 10⁻⁶ M and at pH 7 and 4 has been considered. The change of pigments (chlorophylls a, b and vegetal carotenoids) with time, as well as the labile and total lead in the medium and in the alga and the fluorescence compounds released by the alga, have also been analysed.Relationships between phosphorus in the alga and the pigments and lead in the cell, as well as between phosphorus and fluorescence compounds exudated by each unit of the unicellular alga, have been examined in order to try to understand the biochemical mechanism.     

Effect of Cr2O3 on the electrical properties of multicomponent ZnO varistors at the pre-breakdown region

The effect of Cr₂O₃ on the electrical properties of the multicomponent ZnO varistors was investigated using voltage-current curves and impedance spectroscopy. The structure and morphological modifications were analysed by X-ray diffraction and scanning electron microscopy, respectively. It was observed in samples with addition 0.1 mol % Cr₂O₃ that there was an improvement in the electrical properties of the varistors, but the increase in concentration had a deleterious effect on the potential barrier at the grain boundary. The excess Cr₂O₃ segregates at the grain-boundary region and increases the donor concentration, leading to a higher leakage current.     

Performance of lattice codes over the Gaussian channel

We derive an upper bound on the error probability of lattice codes combined with Quadrature Amplitude Modulation (qam) over the additive white Gaussian noise channel. This bound depends on a lattice figure of merit and is readily put in exponential form by using Chernoff bound. An interesting lower bound is derived by a similar reasoning. We also examine the estimation of the average information rate based upon the continuous approximation of the average power normalized to two dimensions, and suggest to improve it by using the sphere packing idea. Examples of performance evaluation are given for a few lattices. Finally, we present upper and lower bounds on the best fundamental coding gains per dimension (due to both density and thickness) for an arbitrarily large number of dimensions. It is shown in the Appendix that, as the Ungerboeck codes, the lattice codes do not shape the signal power spectrum.     

Enhanced Permeability and Binding Activity of Isobutylene‐Grafted Peptides

We present a new peptide‐macrocyclization strategy with an isobutylene graft. The reaction is mild and proceeds rapidly and efficiently both for linear and cyclic peptides. The resulting isobutylene‐grafted peptides possess improved passive membrane permeability due to the shielding of the polar backbone of the amides, as demonstrated by NMR spectroscopy and molecular dynamics simulations. The isobutylene‐stapled structures are fully stable in human plasma and in the presence of glutathione. This strategy can be applied to bioactive cyclic peptides such as somatostatin. Importantly, we found that structural preorganization forced by the isobutylene graft leads to a significant improvement in binding. The combined advantages of directness, selectivity, and smallness could allow application to peptide macrocyclization based on this attachment of the isobutylene graft.     

The acute effects of plyometric and sled towing stimuli with and without caffeine ingestion on vertical jump performance in professional soccer players

Background

Post-activation potentiation (PAP) is the phenomenon by which muscular performance is enhanced in response to a conditioning stimulus. PAP has typically been evidenced via improved counter movement jump (CMJ) performance. This study examined the effects of PAP, with and without prior caffeine ingestion, on CMJ performance.

Methods

Twelve male professional soccer players (23?±?5 years) performed two trials of plyometric exercises and sled towing 60 min after placebo or caffeine ingestion (5 mg.kg^??1) in a randomized, counterbalanced and double-blinded design. CMJ performance was assessed at baseline and 1, 3 and 5 min after the conditioning stimulus (T1, T3 and T5, respectively).

Results

Two way ANOVA main effects indicated a significant difference in jump height after the PAP protocol (F[3, 11]?=?14.99, P?<?0.001, partial η2?=?0.577). Analysis also indicated a significant difference in CMJ performance across conditions, with caffeine eliciting a greater response (F[1, 11]?=?10.12, P?=?0.009, partial η2?=?0.479). CMJ height was increased at T1, T3 and T5 in caffeine condition (5.07%, 5.75% and 5.40%, respectively; P?<?0.01) compared to baseline. In the placebo condition, jump performance was increased at T3 (4.94%; P?<?0.01) only. Jump height was higher in caffeine condition on T1, T3 and T5 (P?<?0.05) but not on baseline (P?>?0.05) compared to placebo.

Conclusions

The results of this study suggest that acute plyometric and sled towing stimuli enhances jump performance and that this potentiation is augmented by caffeine ingestion in male soccer players.