Occupational exposure to pesticides deregulates systemic cortisol levels in women with breast cancer and correlates with poor prognosis features

Pesticides have been pointed out as hormone disruptors and may significantly affect the prognosis of hormone-dependent diseases such as breast cancer (BC). Here, we investigated the impact of occupational pesticide exposure on systemic cortisol levels in female rural workers diagnosed with BC. Occupational exposure was assessed by interviews with a standardized questionnaire. Plasma samples (112 from pesticide-exposed women and 77 from unexposed women) were collected in the afternoon, outside the physiological cortisol peak, and analyzed by a chemiluminescent paramagnetic immunoassay for the quantitative determination of cortisol levels in serum and plasma. The results from both groups were categorized according to patients' clinicopathological and exposure data. BC pesticide-exposed women presented higher levels of cortisol than the unexposed. Higher cortisol levels were also detected in the exposed group with more aggressive disease (triple-negative BC), with tumors over 2 cm, with lymph node metastases, and with high risk of disease recurrence and death. These findings demonstrated that there is an association between pesticide exposure and BC that affected cortisol levels and correlated to poor disease prognosis.

Footwear designed to enhance energy return improves running economy compared to a minimalist footwear: does it matter for running performance?

The present study compared the effects of a footwear designed to enhance energy return (thermoplastic polyurethane, TPU) vs minimalist shoes on running economy (RE) and endurance performance. In this counterbalanced and crossover design study, 11 recreational male runners performed two submaximal constant-speed running tests and two 3-km time-trials with the two shoe models. Oxygen uptake was measured during submaximal constant-speed running tests in order to determine the RE at 12 km/h and oxygen cost of running (CTO2) at individual average speed sustained during the 3-km running time-trials wearing either of the two shoes. Our results revealed that RE was improved (2.4%) with TPU shoes compared with minimalist shoes (P=0.01). However, there was no significant difference for CTO2 (P=0.61) and running performance (P=0.52) comparing the TPU (710±60 s) and the minimalist (718±63 s) shoe models. These novel findings demonstrate that shoes with enhanced mechanical energy return (i.e. TPU) produced a lower energy cost of running at low (i.e., 12 km/h) but not at high speeds (i.e., average speed sustained during the 3-km running time-trial, ∼15 km/h), ultimately resulting in similar running performance compared to the minimalist shoe.

Biomass components and structure of massai grass fertilized with nitrogen and grazed by sheep / Componentes da biomassa e estrutura do capim-massai adubado com nitrogênio e pastejado por ovinos

To evaluate the biomass components of massai grass subjected to nitrogen (N) fertilization levels (control - 0; 400; 800 and 1200 kg ha-1 year-1 of N) and under rotational stocking with sheep, this study was undertaken using a completely randomized design with measurements repeated in time. A quadratic response was observed reaching maximum values as the levels of nitrogen fertilization increased for green forage biomass, green leaf biomass, green stem biomass (5,172.9; 4,146.3; 1,033.9 kg ha-1 cycle-1, respectively), forage total density (179.1 kg ha-1 cm-1), canopy height (36.8 cm) and live material/dead material ratio (4.0) at levels 896; 934; 797; 879.2; 751.4 and 1,161 kg ha-1 year-1 of N, respectively. For all variables, oscillation was observed between the grazing cycles studied. Nitrogen fertilization has a positive response on the biomass components and canopy structure of massai grass.(AU)

Objetivou-se avaliar os componentes da biomassa do capim-massai sob lotação rotativa com ovinos e adubado com doses de nitrogênio (controle - 0; 400; 800 e 1200 kg de N ha -1 ano -1 ), em delineamento inteiramente ao acaso, com medidas repetidas no tempo. Constatou-se resposta quadrática, alcançando valores máximos com o incremento das doses de nitrogênio para as produções de biomassa de forragem verde, de lâmina foliar verde, de colmo verde (5172,9; 4146,3; 1033,9 kg ha -1 ciclo -1 , respectivamente) e para a densidade total de forragem (179,1 kg ha -1 cm -1 ), altura do dossel (36,8 cm) e relação material vivo/material morto (4,0) nas doses 896; 934; 797; 879,2; 751,4 e 1161 kg ha -1 ano -1 de N, respectivamente. Para todas as variáveis, verificou-se oscilação entre os ciclos de pastejo estudados. A adubação nitrogenada exerce respostas positivas sobre os componentes da biomassa e a estrutura do dossel do capim-massai.(AU)

Desempenho de ovinos em capim-tanzânia sob lotação rotativa com quatro proporções de suplementação concentrada / Performance of sheep raised on Tanzania grass under intermittent stocking with four proportions of concentrate supplementation

Avaliou-se o desempenho de ovinos em capim-tanzânia sob lotação rotativa com quatro proporções de suplementação concentrada 0 por cento, 0,6 por cento, 1,2 por cento e 1,8 por cento do peso vivo (PV), e oito repetições, em delineamento inteiramente ao acaso, com período de ocupação de três dias e descanso de 21 dias. Foram avaliados o ganho médio diário (GMD), o ganho de peso total (GPT), o número de dias para alcançar 12kg (D12), a taxa de lotação em ovinos/ha (TLO) e em UA/ha (TLUA), o rendimento de peso vivo (RPV) e a conversão alimentar do concentrado (CAC). Observou-se efeito quadrático da proporção de suplementação sobre o GMD que foi estimado em 65,87 e 113,15g/dia para os animais não suplementados e suplementados com 1,8 por cento do PV. O suplemento também teve efeito quadrático sobre o GPT. O D12 estimado para os ovinos não suplementados foi de 204 dias, reduzindo-se para 113 dias para os animais suplementados com 1,8 por cento do PV. Quanto à TLO e TLUA, observou-se efeito quadrático da proporção de suplementação. Observou-se efeito linear negativo da proporção de suplementação sobre RPV. A CAC foi melhor entre os animais suplementados com 0,6 por cento do PV. A utilização da suplementação até 1,2 por cento PV melhorou o desempenho dos ovinos em pastejo.

This study evaluated the performance of sheep raised on Tanzania grass under intermittent stocking with four supplementation proportions 0; 0.6; 1.2, and 1.8 percent of live weight (LW) and eight replicates, in a completely randomized design with tree grazing periods, and 21 rest periods. The average daily gain (GMD), the total weight gain (GPT), the days to reach 12kg (D12), the stocking rate (sheep/ha - TLO and animal unit/ha - TLUA), the live weight yield (RPV), and the concentrate: gain ratio (CAC) was evaluated. It was observed a square effect of supplementation proportions on GMD, estimated in 65.87 and 113.15g/day for male sheep that was not supplemented and received 1.8 percent LW supplement. It was observed a square effect of supplementation level on GPT. The D12 to 0 percent LW level was estimated in 204 days, decreasing to 113 days when the sheep received 1.8 percent LW supplement. It was observed square effects of supplementation proportions on TLO and TLUA. It was observed a negative linear effect of supplementation proportions on RPV. The CAC presented the best response for sheep that received 0.6 percent LW supplementation proportion. It can be concluded that sheep supplementation until 1.2 percent LW level provided improvement on performance of grazing sheep.

Gentamicin-induced preconditioning of proximal tubular LLC-PK1 cells stimulates nitric oxide production but not the synthesis of heat shock protein

Nephrotoxicity is the main side effect of antibiotics such as gentamicin. Preconditioning has been reported to protect against injuries as ischemia/reperfusion. The objective of the present study was to determine the effect of preconditioning with gentamicin on LLC-PK1 cells. Preconditioning was induced in LLC-PK1 cells by 24-h exposure to 2.0 mM gentamicin (G/IU). After 4 or 15 days of preconditioning, cells were again exposed to gentamicin (2.0 mM) and compared to untreated control or G/IU cells. Necrosis and apoptosis were assessed by acridine orange and HOESCHT 33346. Nitric oxide (NO) and endothelin-1 were assessed by the Griess method and available kit. Heat shock proteins were analyzed by Western blotting. After 15 days of preconditioning, LLC-PK1 cells exhibited a significant decrease in necrosis (23.5 ± 4.3 to 6.5 ± 0.3%) and apoptosis (23.5 ± 4.3 to 6.5 ± 2.1%) and an increase in cell proliferation compared to G/IU. NO (0.177 ± 0.05 to 0.368 ± 0.073 ìg/mg protein) and endothelin-1 (1.88 ± 0.47 to 2.75 ± 0.53 pg/mL) production significantly increased after 15 days of preconditioning compared toG/IU. No difference in inducible HSP 70, constitutive HSC 70 or HSP 90 synthesis in tubular cells was observed afterpreconditioning with gentamicin. The present data suggest that preconditioning with gentamicin has protective effects on proximal tubular cells, that involved NO synthesis but not reduction of endothelin-1 or production of HSP 70, HSC 70, or HSP 90. We conclude that preconditioning could be a useful tool to prevent the nephrotoxicity induced by gentamicin.

Assessment of body surface temperature in cetaceans: an iterative approach

A transferência de energia térmica da superfície corporal para a água é provavelmente o aspecto mais importante do equilíbrio térmico em mamíferos marinhos, mas os respectivos cálculos dependem do conhecimento da temperatura da superfície, Ts, cuja medição direta em animais em liberdade constitui um problema difícil de resolver. Um método iterativo é proposto para a predição de Ts de cetáceos em liberdade, a partir da temperatura corporal profunda, da velocidade de deslocamento e da temperatura e propriedades termodinâmicas da água.