Effects of estrogen-depletion on rat casein gene expression

Mammary tissue from rats that had been ovariectomized and adrenalectomized 4 weeks previously was compared to that from intact rats in terms of epithelial content and hormone-responsiveness in vitro. The endocrinectomy resulted in about a 30% enlargement of the gland, but led to a loss of only about 12% of the epithelium. This estrogen-depleted epithelium was able to acquire full responsiveness in vitro to insulin in terms of the accumulation of alpha-aminoisobutyric acid, and induction of glucose-6-phosphate and gluconate-6-phosphate dehydrogenases. It was also fully responsive to cortisol in relation to the induction of NADH-cytochrome C reductase, and to prolactin in terms of total RNA synthesis. However, estrogen-depletion led to an 82% loss in the ability of a unit amount of the epithelium to synthesize casein in response to these 3 hormones, and to a similar loss in relation to the accumulation of 25K casein mRNA. Estrogen administration in vivo could prevent and reverse the casein lesion. The disparity between constitutive and casein hormone-responsiveness in the absence of estrogen is discussed in relation to cell commitment.     

HETEROCHRONIC DEVELOPMENTAL PLASTICITY IN LARVAL SEA URCHINS AND ITS IMPLICATIONS FOR EVOLUTION OF NONFEEDING LARVAE

Preexisting developmental plasticity in feeding larvae may contribute to the evolutionary transition from development with a feeding larva to nonfeeding larval development. Differences in timing of development of larval and juvenile structures (heterochronic shifts) and differences in the size of the larval body (shifts in allocation) were produced in sea urchin larvae exposed to different amounts of food in the laboratory and in the field. The changes in larval form in response to food appear to be adaptive, with increased allocation of growth to the larval apparatus for catching food when food is scarce and earlier allocation to juvenile structures when food is abundant. This phenotypic plasticity among full siblings is similar in direction to the heterochronic evolutionary changes in species that have greater nutrient reserves within the ova and do not depend on particulate planktonic food. This similarity suggests that developmental plasticity that is adaptive for feeding larvae also contributes to correlated and adaptive evolutionary changes in the transition to nonfeeding larval development. If endogenous food supplies have the same effect on morphogenesis as exogenous food supplies, then changes in genes that act during oogenesis to affect nutrient stores may be sufficient to produce correlated adaptive changes in larval development.     

Evaluating spatial within plot crop variability for different management practices with an optical sensor?

Subsoil constraints to root growth exacerbate frequent water and nutrient limitations to crop yields in Mediterranean-type environments. Amelioration of subsoil constraints can relieve these limitations by opening root-access to subsoil water and nutrients. However, decisions in subsoil amelioration are hampered by seasonally variable yield responses in these environments. We used the APSIM model to analyse the impact of subsoil constraints on yield and yield variability. The simulated yield data were used to calculate the financial benefits of subsoil amelioration across several scenarios. There was a strong yield-dependence on accessible soil water governed by root depth. Root depth development was limited to a minimum of either the effect of subsoil constraints or the weather-dependent depth of the soil wetting front. Insufficient rainfall in dry years or in a drier region often resulted in shallow soil wetting fronts and correspondingly shallow roots even in the absence of subsoil compaction. In these situations, there is little response to subsoil amelioration. Positive yield responses and positive financial returns to subsoil amelioration are therefore greater in good rainfall years and are more likely in a wetter region. A yield response to amelioration is also greater in coarser textured sand than finer textured sandy loam in an average rainfall season because the same amount of rainfall results in a deeper wetting front in sand than in sandy loam. Hence, roots in a sand are required to grow deeper compared to a sandy loam to access the same amount of water and therefore benefited more from subsoil amelioration in an average rainfall year. In wet years, sands leach more nitrate than sandy loam, which decreases yields and the response to subsoil amelioration in sands is more than in the sandy loam. Environmental threats occur along with yield loss when roots cannot access subsoil water. These include increased nitrate leaching and deep drainage due to unused water remaining in the soil profile. By allowing roots to access deep soil water, ameliorating subsoil is expected to yield financial gains in average to good rainfall seasons and decrease the environmental risk of drainage and leaching loss. The financial gains are expected to offset potential financial losses in dry and dry finish seasons especially in coarser textured soils and wetter environment. Responsible Editor: Jan Vos.     

Sporophytic response to pollen selection for Alachlor tolerance in maize

In order to assess the efficiency of male gametophytic selection (MGS) for crop improvement, pollen selection for tolerance to herbicide was applied in maize. The experiment was designed to test the parallel reactivity to Alachlor of pollen and plants grown in controlled conditions or in the field, the response to pollen selection in the sporophytic progeny, the response to a second cycle of MGS, and the transmission of the selected trait to the following generations. The results demonstrated that pollen assay can be used to predict Alachlor tolerance under field conditions and to monitor the response to selection. A positive response to selection applied to pollen in the sporophytic progeny was obtained in diverse genetic backgrounds, indicating that the technique can be generally included in standard breeding programs; the analysis of the data produced in a second selection cycle indicated that the selected trait is maintained in the next generation.     

Permeability of the blood-brain barrier to peptides: An approach to the development of therapeutically useful analogs

Peptides have been shown in both in vivo and in vitro systems to cross the blood-brain barrier (BBB) and so affect function on the side contralateral to their origin. Some peptides cross primarily by transmembrane diffusion, a nonsaturable mechanism largely dependent on the lipid solubility of the peptide. Other peptides are transported by saturable systems across the BBB. These transport systems can be in the CNS to blood direction, as in the cases of Tyr-MIF-1 and methionine enkephalin, in the blood to CNS direction, as in the case of peptide T, or bidirectional, as in the case of LHRH. Other factors that also affect the amount of peptide crossing the BBB include binding in blood, volume of distribution, enzymatic resistance, and half-time disappearance from the blood. An in vitro model of the BBB has been characterized and used to confirm that peptides can cross the BBB. Results with the model agree with those obtained in vivo and have been used to study the permeability of the BBB to peptides, the effect of peptides on BBB integrity, the cellular pathway peptides and proteins use to cross the BBB, and the ability of the BBB to degrade peptides. The in vivo and in vitro methods have been used together to develop halogenated enkephalin analogs that are enzymatically resistant, cross the BBB readily to accumulate in areas of the brain rich in opiate receptors, and are powerful analgesics. This shows how the principles elucidated for peptide passage across the BBB can be used to develop therapeutic peptides and how those peptides can be further tested in complementary in vivo and in vitro systems.     

Nutrient salts and the toxicity of black-layer induced by cyanobacteria and Desulfovibrio desulfuricans to Agrostis palustris

Cyanobacteria and Desulfovibrio desulfuricans can interact to form a subsurface black-layer in high-sand content golf greens that impairs internal water drainage and results in the decline of the Agrostis palustris turfgrass on the green. Research was initiated to evaluate the effect of mineral salts (sulfur, iron, lime) and fructose (a soluble carbohydrate) added to a balanced nutrient salts control solution on the development and toxicity of black-layer to the growth of A. palustris. The various nutrient salts combinations were applied to single isolates of cyanobacteria and D. desulfuricans in nonblack-layered sand, and to the combination of cyanobacteria and D. desulfuricans (necessary for black-layer development) in black- layered sand. Dry weights of A. palustris treated with the salts control decreased with individual isolates of cyanobacteria and more so in the blackened sand produced by the combinations of cyanobacteria and D. desulfuricans. The addition of sulfur to the salts control increased dry weights of A. palustris growing with single isolates of cyanobacteria and in the sand blackened by the combinations of cyanobacteria and D. desulfuricans compared with the salts control; dry weight decreased in response sulfur only in nonblackened sand with D. desulfuricans alone. The addition of iron to the salts control produced the greatest increase in dry weight relative to the salts control among all single and combined microorganisms, except for D. desulfuricans. The addition of lime or fructose to the salts control decreased dry weight among plants growing in the no-organism control, with D. desulfovibrio alone, and with individual isolates of cyanobacteria relative to the salts control. Dry weights in response to lime and fructose in sand blackened by the combination of cyanobacteria and D. desulfuricans remained unchanged or decreased relative to the salts control. Growing roots of A. palustris cleared the blackening in sand and showed gold-colored cortical cells with blackened cell walls and vascular cylinders. The observations are discussed relative to the role of the various salts on the toxicity of D. desulfuricans to A. palustris in black-layered and nonblack-layer sand.     

Role and function of cytokinin oxidase in plants

Cytokinin oxidase (CK oxidase) is widely distributed in plants and is the only enzyme that has been shown unequivocally to catalyze the catabolism of specific cytokinins (CKs) to inactive products that lack the N⁶-unsaturated side chain. Thus, the enzyme is thought to play a major role in controlling the level or species of CKs in plant tissues. However, despite its discovery more than 25 years ago, little attention has been given to the elucidation of its role and function in plant growth and development. This review seeks to bring in to context the current state of knowledge regarding the biochemical and molecular properties, regulation in undifferentiated and differentiated tissues, and recent results from studies using transgenic plants in an attempt to provide a more comprehensive understanding of the physiological significance of the enzyme in plants. Notwithstanding species, tissue and other specific differences, in general, CK oxidase appears to contribute to CK homeostasis in plants. However, complete clarity as to its function awaits purification of the protein to homogeneity and the ultimate development of requisite molecular probes.     

北戴河朱鹮野化种群非繁殖期日间活动时间分配和行为节律

于2019年7月-2020年1月对北戴河朱鹮野化种群非繁殖期的日间活动时间分配和行为节律进行了分析。结果表明,休息（41.8%）、觅食（39.7%）和理羽（13.3%）是北戴河朱鹮非繁殖期的主要行为。在行为节律上,有3个觅食高峰、2个休息高峰和2个理羽高峰。成鸟和幼鸟行为分配相似,但成鸟的警戒和社群等其他行为比例显著较高。与野生种群相比,北戴河野化种群的觅食时间显著较少,主要原因是野生个体需要花费较多时间搜寻食物,且飞行等活动的能耗较高。朱鹮在冬季的休息和理羽行为比例高于夏秋季,觅食行为则相反,这样可以在低温和大风天气降低能耗,是对北戴河气候环境的有效适应。为了提高朱鹮对多种气候环境的适应能力,为今后北戴河朱鹮的再引入奠定基础,我们建议在冬季要确保朱鹮有充足的适宜觅食地,同时在野化网笼中进行必要的环境丰容,如在网笼内增加常绿树种和阔叶树种,部分侧网上安装防风板,或在网笼中设置防风避寒的伞棚等设施,以供朱鹮进行选择。     

Burden of cancer attributable to tobacco smoking in member countries of the Association of Southeast Asian Nations (ASEAN), 2012

BackgroundCancer is an increasing problem in ASEAN (Association of Southeast Asian Nations). Tobacco use is a well-established risk factor for many types of cancers. Evidence on burden of cancer attributable to tobacco is essential to raise public and political awareness of the negative effects of tobacco on cancer and to be used to stimulate political action aims at reducing smoking prevalence in ASEAN member countries. The objective of this study was to estimate burden of cancer attributable to tobacco smoking in ASEAN, 2012.MethodsIn this study, smoking prevalence was combined with Relative Risks (RRs) of cancer to obtain Smoking Attributable Fractions (SAFs). Cancer incidence and mortality data among individuals aged 15 years and older were derived from GLOBOCAN 2012. Fourteen types of cancer were included in the analysis. Sensitivity analyses were conducted to examine the impact of the use of alternative RRs and the use of alternative prevalence of smoking in some countries.ResultsThe findings showed that tobacco smoking was responsible for 131,502 cancer incidence and 105,830 cancer mortality in ASEAN countries in 2012. In other words, tobacco smoking was accounted for 28.4% (43.3% in male and 8.5% in female) of cancer incidence and 30.5% (44.2% in male and 9.4% in female) of cancer mortality in ASEAN. When looking at the types of cancer, lung cancer showed the strongest association with tobacco smoking. Incidence of cancer and cancer mortality attributable to tobacco smoking varied by countries due to the differences in size of population, background risk of cancer, and prevalence of smoking in each country. According to the sensitivity analyses, RRs of lung cancer, pharynx cancer, and larynx cancer used in the estimates have significant impact on the estimates.ConclusionsAs about one-third of cancer incidence and mortality in ASEAN are attributable to tobacco smoking ASEAN member countries are strongly encouraged to put in place stronger tobacco control policies and to strengthen the existing tobacco control measure in order to effectively control cancer.     

Population differentiation and species cohesion in two closely related plants adapted to neotropical high-altitude 'inselbergs', Alcantarea imperialis and Alcantarea geniculata (Bromeliaceae)

Isolated granitic rock outcrops or 'inselbergs' may provide a window into the molecular ecology and genetics of continental radiations under simplified conditions, in analogy to the use of oceanic islands in studies of species radiations. Patterns of variability and gene flow in inselberg species have never been thoroughly evaluated in comparison to related taxa with more continuous distribution ranges, or to other species in the same kingdom in general. We use nuclear microsatellites to study population differentiation and gene flow in two diploid, perennial plants adapted to high-altitude neotropical inselbergs, Alcantarea imperialis and Alcantarea geniculata (Bromeliaceae). Population differentiation is pronounced in both taxa, especially in A. imperialis. Gene flow in this species is considerably lower than expected from the literature on plants in general and Bromeliaceae in particular, and too low to prevent differentiation due to drift (N(e)m < 1), unless selection coefficients/effect sizes of favourable alleles are great enough to maintain species cohesion. Low gene flow in A. imperialis indicates that the ability of pollinating bats to promote gene exchange between inselbergs is smaller than previously assumed. Population subdivision in one inselberg population of A. imperialis appears to be associated with the presence of two colour morphs that differ in the coloration of rosettes and bracts. Our results indicate a high potential for inselbergs as venues for studies of the molecular ecology and genetics of continental radiations, such as the one that gave rise to the extraordinary diversity of adaptive strategies and phenotypes seen in Bromeliaceae.     

湖北省褐飞虱对吡虫啉、噻嗪酮及氟虫腈的抗药性监测

采用稻茎浸渍法监测湖北省武穴、天门、监利、通城、孝感、公安及枣阳七地褐飞虱Nilaparvata lugens(Sta1)田间种群对吡虫啉、噻嗪酮、氟虫腈的抗药性。结果表明:2006、2007和2008年3年7地褐飞虱种群对吡虫啉的抗性分别为98.89～389.19倍、69.00～153.33倍和56.32～116.89倍,达高水平至极高水平抗性,但3年期间总体抗性水平呈现一定程度的下降趋势;2007和2008年2年7地褐飞虱对噻嗪酮的抗性分别为13.39～41.06倍和6.94～20.44倍,达低水平至高水平抗性;2007和2008年2年7地褐飞虱对氟虫腈抗性分别为0.97～2.64倍和0.63～1.42倍,为敏感阶段。此外,还对褐飞虱的治理进行讨论。     

The future burden of cancer in Canada: Long-term cancer incidence projections 2013–2042

BackgroundCancer is the leading cause of death in Canada and the estimated annual spending associated with cancer is approximately $7.5 billion. Projecting the future burden of cancer in Canada is essential for health planning and evaluation. We aimed to estimate the future incidence of cancer in Canada to 2042.MethodsAge-sex-region-specific cancer incidence data were obtained for the years 1983-2012 and cancer incidence was projected from 2013 to 2042 for the top five cancer sites. The modelling algorithm combined a mixture of cancer projection methods to select the best-fitted model. When the chosen model produced by the modelling algorithm resulted in estimates that were not consistent with expert opinion, an alternate model was selected that took into consideration historical changes in policy, screening and lifestyle behaviours. Incidence projections were made for Canada and its provinces.ResultsLung cancer incidence is estimated to rise to 14,866 cases in men and 19,162 in women in 2042. Colorectal cancer incidence is estimated to rise to 28,146 in men and 21,102 in women. Cases of bladder cancer are projected to rise to 10,708 and 3,364 in men and women, respectively. Breast cancer incidence is predicted to rise to 40,712 and prostate cancer incidence is projected to rise to 92,949.ConclusionThese cancer incidence projections up to 2042 can be used for planning cancer control strategies and prevention programs. Given the ongoing changes in the prevalence of risk factors and in cancer prevention policies, these estimates should be interpreted with caution.     

Strategies for acclimation to seasonal drought in Ceratonia siliqua leaves

Plants of Ceratonia siliqua L. (carob tree) were subjected to a slow cycle of soil water depletion in summer and in winter. Recently mature and fully turgid leaves were squeezed in a pressure chamber in order to analyse changes in the components of water potential related to the acclimation to drought. Mathematical expressions were fitted to the primary data in order to calculate the elasticity modulus and the dependence of turgor pressure on relative osmotic water content. Osmotic and water potentials decreased significantly in leaves acclimated during the summer (about 0.7 and 0.9 MPa decrease, respectively) whereas in winter the elastic properties of the wall had changed: modulus of the non-stressed leaves was 26 MPa compared to 7.5 MPa in leaves subjected to drought stress. The results indicate that Ceratonia leaves can, to some extent, maintain turgor under situations of soil drought, using different strategies according to the season.     

Impact of vitamin E or selenium deficiency on nematode-induced alterations in murine intestinal function

The effects of deficiencies in the antioxidant nutrients, vitamin E and selenium, on the host response to gastrointestinal nematode infection are unknown. The aim of the study was to determine the effect of antioxidant deficiencies on nematode-induced alterations in intestinal function in mice. BALB/c mice were fed control diets or diets deficient in selenium or vitamin E and the response to a secondary challenge inoculation with Heligmosomoides polygyrus was determined. Egg and worm counts were assessed to determine host resistance. Sections of jejunum were mounted in Ussing chambers to measure changes in permeability, absorption, and secretion, or suspended in organ baths to determine smooth muscle contraction. Both selenium and vitamin E deficient diets reduced resistance to helminth infection. Vitamin E, but not selenium, deficiency prevented nematode-induced decreases in glucose absorption and hyper-contractility of smooth muscle. Thus, vitamin E status is an important factor in the physiological response to intestinal nematode infection and may contribute to antioxidant-dependent protective mechanisms in the small intestine.     

Sexual dimorphism and synchrony of breeding: variation in polygyny potential among populations in the common brushtail possum, Trichosurus vulpecula

Male-biased sexual dimorphism in both size and body mass isa common characteristic of many polygynous mammals and is oftenattributed to sexual selection favoring large males. The degreeof dimorphism is thought to be related to the potential forsome males to monopolize access to estrous females, which isin turn related to the distribution of receptive females inspace and time. In the present study, we investigated the relationshipbetween the temporal distribution of breeding females and thedegree of mass dimorphism among 11 populations of the commonbrushtail possum from northern Australia. Breeding patternsvaried from complete aseasonality in some populations to a seasonalconcentration of births within 2 or 3 months in others. We predictedthat in populations in which mating opportunities were distributedthroughout the year, dominant males would be able to monopolizeaccess to larger numbers of estrous females than in populationsin which matings were more seasonal, and in such populations,large body size in males would be favored. We found that dimorphismwas related to seasonality of breeding, being greatest in populationswith a more aseasonal pattern. Mean body mass of male possumsalso decreased with increasing population density. Populationdensity may influence the degree of breeding synchrony withinpopulations, particularly in locations with a more seasonalclimate. The present study is the first to demonstrate plasticityin mass dimorphism in response to local variation in the synchronyof breeding in a mammal species.     

Mineralocorticoid receptors in immune cells: Emerging role in cardiovascular disease

Mineralocorticoid receptors (MRs) contribute to the pathophysiology of hypertension and cardiovascular disease in humans. As such, MR antagonists improve cardiovascular outcomes but the molecular mechanisms remain unclear. The actions of the MR in the kidney to increase blood pressure are well known, but the recent identification of MRs in immune cells has led to novel discoveries in the pathogenesis of cardiovascular disease that are reviewed here. MR regulates macrophage activation to the pro-inflammatory M1 phenotype and this process contributes to the pathogenesis of cardiovascular fibrosis in response to hypertension and to outcomes in mouse models of stroke. T lymphocytes have recently been implicated in the development of hypertension and cardiovascular fibrosis in mouse models. MR activation in vivo promotes T lymphocyte differentiation to the pro-inflammatory Th1 and Th17 subsets while decreasing the number of anti-inflammatory T regulatory lymphocytes. The mechanism likely involves activation of MR in antigen presenting dendritic cells that subsequently regulate Th1/Th17 polarization by production of cytokines. Alteration of the balance between T helper and T regulatory lymphocytes contributes to the pathogenesis of hypertension and atherosclerosis and the associated complications. B lymphocytes also express the MR and specific B lymphocyte-derived antibodies modulate the progression of atherosclerosis. However, the role of MR in B lymphocyte function remains to be explored. Overall, recent studies of MR in immune cells have identified new mechanisms by which MR activation may contribute to the pathogenesis of organ damage in patients with cardiovascular risk factors. Conversely, inhibition of leukocyte MR may contribute to the protective effects of MR antagonist drugs in cardiovascular patients. Further understanding of the role of MR in leukocyte function could yield novel drug targets for cardiovascular disease.     

Is the signal from the mesophyll to the guard cells a vapour‐phase ion?

Previous studies have suggested that the red light and CO₂ responses of stomata are caused by a signal from the mesophyll to the guard cells. Experiments were conducted to test the idea that this signal is a vapour‐phase ion. Stomata in isolated epidermes of Tradescantia pallida were found to respond to air ions created by an electrode that was positioned under the epidermes. Anthocyanins in the epidermes of this species were observed to change colour in response to these air ions, and this change in colour was attributed to changes in pH. A similar change in lower epidermal colour was observed in intact leaves upon illumination and with changes in CO₂ concentration. Based on the change in epidermal colour, the pH of the epidermis was estimated to be approximately 7.0 in darkness and 6.5 in the light. Stomata in isolated epidermes responded to pH when suspended over (but not in contact with) solutions of different pH. We speculate that stomatal responses to CO₂ and light are caused by vapour‐phase ions, possibly hydronium ions that change the pH of the epidermis.     

Meta-analysis of feed intake and growth responses of growing pigs after a sanitary challenge

Sanitary challenges negatively affect feed intake and growth, leading to a negative impact on animal well-being and economic losses. The aim of this study was to carry out a meta-analysis to quantify the dynamic feed intake and growth responses of growing pigs after a sanitary challenge. A database was constructed using 122 published experiments reporting the average daily feed intake (ADFI) and the average daily gain (ADG) of pigs subjected to one of six sanitary challenges: digestive bacterial infections, poor housing conditions, lipopolysaccharide (LPS) challenges, mycotoxicoses, parasitic infections and respiratory diseases. The responses to experimental challenges were calculated relative to that of a control group. Statistical analyses were carried out for each challenge to quantify the mean and the dynamic responses in feed intake and growth and to identify the basis of the reduction in growth (i.e. reduction in feed intake or reduction in feed efficiency related to changes in maintenance requirements). All challenges resulted in a reduction in ADFI and ADG, with the strongest responses for mycotoxicoses, respiratory diseases and digestive bacterial infections (8% to 23% reduction in ADFI and 16% to 29% reduction in ADG). The reduction in ADG was linearly related to the reduction in ADFI for digestive bacterial infections, LPS challenge, parasitic infections and respiratory diseases. For poor housing conditions and mycotoxicoses, the relationship was curvilinear. A 10% reduction in ADFI resulted in a reduction in ADG varying from 10% for mycotoxicoses to 43% for digestive bacterial infections. More than 70% of the reduction in ADG could be explained by the reduction in ADFI for mycotoxicoses, LPS challenge and respiratory diseases. For challenges associated with the gastrointestinal tract, a large part of the reduction in ADG was due to an increase in maintenance requirements, suggesting digestive and metabolic changes. A dynamic pattern in the reduction in feed intake and growth rate could be identified for digestive bacterial infections, mycotoxicoses and respiratory diseases. For digestive bacterial infections and mycotoxicoses, pigs did not fully recover from the challenge during the experimental period. The results of this study can be used to quantify the effects of a sanitary challenge in growth models of pigs.