Effect of urea supplementation on performance and safety in diets of Dorper crossbred sheep.

This study was conducted to evaluate the efficacy and safety of dietary urea in sheep rations having a 50:50 concentrate:roughage ratio. Sixty-four Dorper × thin-tailed Han crossbred ram lambs with an average body weight of 30.8 (±0.02) kg were randomly divided into four groups of 16 sheep each, and each group was fed one of the following diets: a basal diet (CON), or CON supplemented with 0.5% (0.5UTM), 1.5% (1.5UTM) or 2.5% (2.5UTM) urea. Growth performance, carcass characteristics, non-carcass offals, meat quality and peptic tissue lesions were assayed. The average daily weight gains for CON, 0.5UTM, 1.5UTM and 2.5UTM were 216, 218, 200 and 170 g, respectively, with the CON and 0.5UTM groups higher than 2.5UTM group (p < 0.05). Sheep from the 2.5UTM treatment had a significantly lower dry matter intake (1.29 kg/day) than those from the CON and 0.5UTM treatments (1.42 and 1.43 kg/day, p < 0.05), and the feed conversion ratio in the 2.5UTM group was the highest (p < 0.05). Carcass characteristics, including shrunk body weight, empty body weight, hot carcass weight, dress percentage, and the absolute or relative weight (% body weight) of heart, liver, spleen, lung and kidney, were not altered by the treatments (p > 0.05). The muscular pH of 2.5UTM was higher than that of CON (5.68 vs. 5.52, p < 0.05), and shear force in 0.5UTM was lower compared with CON and 2.5UTM (p < 0.05). The anatomical structure lesions in kidneys became more serious with the increasing dietary urea concentrations, with the 2.5UTM animals showing the most severe lesions compared with CON animals. Therefore, supplementary urea as a non-protein nitrogen source for sheep should not exceed 1.5% of ration having a 50:50 concentrate:roughage ratio to ensure efficacy and safety.

Enhanced T cell immunity by B7-H4 downregulation in nonsmall-cell lung cancer cell lines.

OBJECTIVES: T cell immunity plays a critical role in host immune surveillance of tumour cell growth and metastatic spread. This study used small hairpin (sh)RNA-mediated gene silencing to target VTCN1 (B7-H4) expression in a nonsmall-cell lung cancer (NSCLC) cell line (A549) and evaluated the effects on T cell immune activity using an in vitro coculture system. METHODS: VTCN1-specific shRNA-expressing plasmid was transfected into A549 cells. Mock transfected and empty plasmid-transfected A549 cells served as controls. VTCN1 expression in A549 cells was determined by reverse transcription-polymerase chain reaction (RT-PCR) for VTCN1 mRNA and Western blotting for B7-H4 protein. Transfected A549 cells were cocultured with Jurkat cells. Jurkat cells were examined for proliferation, apoptosis, cell cycle distribution and intracellular cytokine mRNA and protein levels. RESULTS: VTCN1-specific shRNA efficiently knocked down VTCN1 mRNA and B7-H4 protein levels in A549 cells. This downregulation led to enhanced Jurkat cell proliferation, decreased apoptosis, stimulated cell cycle progression and elevated production of interferon-γ, interleukin (IL)-10 and IL-2. CONCLUSIONS: B7-H4 negatively regulates T cell-mediated antitumour immunity in NSCLC.

Diurnal sleep/wake-related immune functions during the menstrual cycle of healthy young women.

Animal and human studies have related the sleeping/waking brain to the immune system. Because women are more susceptible to certain immunological illnesses, and sex steroids regulate immune functions, it was investigated whether the diurnal sleep/wake pattern of aspects of cellular immune functions and interleukin-1 (IL-1) and IL-2-like activities differed during low and high progesterone phases of the menstrual cycle. Eleven healthy women, mean age 24 y, were assessed over 24 h with serial venous blood samples. Peripheral blood monocytes were assayed for mitogen responses, i.e. phytohemagglutin (PHA) and pokeweed (PWM) and natural killer (NK) cell activities. Plasma was assayed for IL-1 and IL-2-like activities, cortisol and progesterone. Data were standardized by Z transformation and analysed by repeated-measures analysis of variance by comparing high (N = 5) vs. low (N = 6) progesterone phases. During the high progesterone phase, delayed slow-wave sleep (SWS) onset time and reduced amount of SWS was accompanied by a delay in the decline of NK cell activity, but rise in PHA activity following sleep onset. With the low progesterone phase, the pattern was similar to men with an early sleep decline in NK cell and late sleep rise in PHA activities. PWM rose during the night and plasma IL-1-like activity peaked during midday and during nocturnal sleep irrespective of the amount of progesterone. Slow-wave sleep and sleep-related NK cell and PHA activities differed over the menstrual cycle, but not PWM response. Increases in plasma IL-1 functions during midday and night are consistent with predisposition to sleepiness during these times.