Steroidogenesis in bovine granulosa cells: the effect of short-term changes in dietary intake

The nutritional status of a cow is a key factor in the regulation of both follicle growth and oocyte quality. In this study, the effect of diets designed to increase circulating insulin and insulin-like growth factor I (IGF-I) concentrations on steroid production by granulosa cells in vitro was examined to analyse the mechanisms through which these changes occur. Hereford x Friesian heifers (n = 24) were offered maintenance or twice maintenance diets during the experimental period (17 days). Circulating concentrations of FSH did not differ between the two dietary groups, whereas insulin and IGF-I concentrations showed significant diet x day of oestrous cycle interactions. Ovaries were collected on day 3 of the first follicle wave after synchronization of oestrus. Granulosa cells were isolated from small (1-4 mm) and medium-sized (4-8 mm) follicles and cultured in the presence of long R3-IGF-I or bFSH or both. After 4 days in culture, granulosa cells isolated from small follicles, but not medium-sized follicles, collected from cattle offered the twice maintenance diet secreted significantly higher (P < 0.05) amounts of oestradiol compared with granulosa cells collected from cattle offered the maintenance diet. The effect was apparent in either the presence or absence of FSH and long R3-IGF-I. This nutritional effect on aromatase activity in granulosa cells was not apparent after day 6 of culture. There was no effect of diet on progesterone production by granulosa cells after 4 or 6 days of culture. These results support the hypothesis that dietary-induced changes in circulating insulin and IGF-I concentrations have a direct effect on the steroidogenic potential of bovine granulosa cells from small follicles. The dietary-induced increases in aromatase activity in small follicles combined with the increased concentration of metabolic hormones are possible mechanisms through which short-term changes in nutrition may affect follicle dynamics.     

Effect of Yeast Extracts Containing Propionic Acid on Bread Dough Fermentation and Bread Properties

ABSTRACT: Three commercial yeast extracts (Oxoid, Champlain, Lallemand) fermented with immobilized cells of Propionibacterium freudenreichii were added in broths and bread formulations, and their effect on growth and gas production by bakers yeast was determined. Appearance and preservation of the breads were examined. There was significantly more gas produced by the yeast when fermented yeast extracts were added to the dough. In broths, the initial growth rate was slower with media containing fermented yeast extract when compared to their unfermented equivalents. Loaves formulated with propionic acid of the fermented yeast extract contained less ethanol. Paired t-tests showed that breads formulated with fermented yeast extract were protected for a longer period against mold than those that contained non-fermented yeast extract.     

Ethnic stereotypes: The significance of consensus.

Investigated whether the degree of consensus in trait attribution to ethnic groups has any particular meaning to the individual. Canadian 9th and 12th graders (n = 36) were presented with traits previously found in the stereotypes about different groups, and asked to identify the ethnic group so characterized. 3 independent variables were manipulated: consensus of the attributes, age of the Ss, and the number of attributes presented. Dependent variables included the accuracy and the perceived difficulty of identification. Results indicate that the degree of consensus in the stereotype had considerable information value to the Ss. This suggests that stereotypes generally develop from information available to a community, and that the consensus noted in stereotype assessment procedures reflects the consistency of this information. (French summary) (16 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cinemetrics: Embodying architectural representation in the digital age

How can architecture emerge from the prison of its current forms of representation? Grahame Shane1 1 D.G. Shane, “Balkanization and the Postmodern City,” in Peter Lang (ed.), Mortal City, New York: Princeton Architectural Press, 1995, pp. 55-69. interprets the concluding diagram of Robin Evans' Projective Cast: Architecture and its Three Geometries2 2 Robin Evans, The Projective Cast: Architecture and Its Three Geometries, Cambridge, MA: MIT Press, 1995. as a critique of postmodern architecture's self-reflection and lack of engagement with the world. Shane argues that Evan's diagram depicts architectural representation as a self-reinforcing, closed, conceptual triangle of mirrored reflections between the human observer, the scopic regime of perspective, orthographic architectural drawing conventions, and designed objects. Shane draws his interpretation from Evans's early work on Victorian prison architecture as well as one of Evan's last public lectures. Shane characterized Evans' critical view of postmodern architectural practice and representation as a “self-correcting means of stabilization and pacification of the physical, built environment.”3 3 Shane, “Balkanization and the Postmodern City,” p. 68 This essay develops a theory of Cinemetrics that demonstrates how contemporary architectural production, with the aid of digital tools, has the capacity to break this closed system with open-ended, embodied cybernetic feed-back loops within a wider public culture engaged in the making and imagining of architecture.4 4 Brian McGrath and Jean Gardner, Cinemetrics: Architectural Drawing Today, London: Wiley-Academy, 2007. This essay argues that this break can only be accomplished by embodying architectural representation through a careful engagement with Gilles Deleuze's philosophy of movement and time images derived from cinema,5 5 Gilles Deleuze, Cinema 1: the movement image, Hugh Tomlinson and Habberjam (trans.), Minneapolis, MN: University of Minnesota, 1986; Cinema 2: the time-image, Hugh Tomlinson and Robert Galeta (trans.), Minneapolis, MN: University of Minnesota, 1989. Henri Bergson's theories of memory, attention and duration,6 6 Henri Bergson, Creative Evolution, Arthur Mitchell (trans.), Lanham, MD: University Press of America, 1991; Henri Bergson, Matter and Memory, M.N. Paul and W.S. Palmer (trans.), New York: Zone Books, 1991. and from Charles Sanders Peirce's pragmatic semiosis.7 7 Charles Sanders Peirce, The Essential Peirce: Selected Philosophical Writings, Vol. 2 (1893-1913), Peirce Edition Project, Bloomington, IN: Indiana University Press, 1998.      

Polyamide 6–Cellulose Composites: Effect of Cellulose Composition on Melt Rheology and Crystallization Behavior

Melt rheology and crystallization behavior of polyamide 6 (PA 6) and microcrystalline cellulose (MCC) composites were systematically studied in this research. The incorporation of MCC into the PA 6 matrix resulted in higher complex viscosities (|η*|), storage modulus (G′), and shear viscosities than those of neat PA 6, especially at low frequencies. The orientation of rigid molecular chains in the composites introduced by the addition of MCC induced a strong shear thinning behavior with an increase in MCC loading. The non‐isothermal crystallization kinetics of PA 6 and MCC composites were investigated by differential scanning calorimetry. The Avrami and Tobin model were applied to describe the process of non‐isothermal crystallization and to determine the crystallization parameters of the composites. Analysis of the crystallization kinetics indicated that the Avrami (n_a) and Tobin exponent (n_t) was altered by the MCC. It was also found that the Avrami and Tobin equations fit the empirical data well. POLYM. ENG. SCI., 54:739–746, 2014. © 2013 Society of Plastics Engineers     

Xenobiotic Metabolism: The Effect of Acute Kidney Injury on Non-Renal Drug Clearance and Hepatic Drug Metabolism

Acute kidney injury (AKI) is a common complication of critical illness, and evidence is emerging that suggests AKI disrupts the function of other organs. It is a recognized phenomenon that patients with chronic kidney disease (CKD) have reduced hepatic metabolism of drugs, via the cytochrome P450 (CYP) enzyme group, and drug dosing guidelines in AKI are often extrapolated from data obtained from patients with CKD. This approach, however, is flawed because several confounding factors exist in AKI. The data from animal studies investigating the effects of AKI on CYP activity are conflicting, although the results of the majority do suggest that AKI impairs hepatic CYP activity. More recently, human study data have also demonstrated decreased CYP activity associated with AKI, in particular the CYP3A subtypes. Furthermore, preliminary data suggest that patients expressing the functional allele variant CYP3A5*1 may be protected from the deleterious effects of AKI when compared with patients homozygous for the variant CYP3A5*3, which codes for a non-functional protein. In conclusion, there is a need to individualize drug prescribing, particularly for the more sick and vulnerable patients, but this needs to be explored in greater depth.     

Influence of Phenological Stage on Swainsonine and Endophyte Concentrations in Oxytropis sericea

Locoweeds are defined as Astragalus and Oxytropis species that cause intoxication due to the alkaloid swainsonine. Swainsonine concentrations in Oxytropis sericea were influenced by location, plant part, and the developmental stage of the plant. Concentrations followed similar trends at each location, generally increasing over the growing season in above-ground parts until the plant reaches maturity with no change in concentration in the crowns. At the onset of senescence, swainsonine decreased in floral parts to less than half of the peak concentration. Similar to swainsonine concentrations, endophyte amounts were influenced by location, plant part, and the developmental stage of the plant. Likewise, endophyte amounts generally increased over the growing season in above ground parts and remained static in the crowns at all four locations. Swainsonine in Oxytropis sericea was positively associated with the endophyte Undifilum, which is responsible for swainsonine biosynthesis.     

Biocatalytic Alkylation Cascades: Recent Advances and Future Opportunities for Late-Stage Functionalization

This Concept article describes the latest developments in the emerging area of late-stage biocatalytic alkylation. Central to these developments is the ability to efficiently prepare S-adenosyl methionine (SAM) cofactor analogues and couple this with enzymatic alkyl transfer. Recent developments in the enzymatic synthesis of SAM cofactor analogues are summarized first, followed by their application as alkyl transfer agents catalyzed by methyltransferases (MTases). Second, innovative methods to regenerate SAM cofactors by enzymatic cascades is reported. Finally, future opportunities towards establishing a generalized platform for late-stage alkylation are described.     

Synthesis and evaluation of 1-amino-6-halo-β-carbolines as antimalarial and antiprion agents

Malaria is one of the world's most devastating parasitic diseases, causing almost one million deaths each year. Growing resistance to classical antimalarial drugs, such as chloroquine, necessitates the discovery of new therapeutic agents for successful control of this global disease. Here, we report the synthesis of some 6-halo-β-carbolines as analogues of the potent antimalarial natural product, manzamine A, retaining its heteroaromatic core whilst providing compounds with much improved synthetic accessibility. Two compounds displayed superior activity to chloroquine itself against a resistant Plasmodium falciparum strain, identifying them as promising leads for future development. Furthermore, in line with previous reports of similarities in antimalarial and antiprion effects of aminoaryl-based antimalarial agents, the 1-amino-β-carboline libraries were also found to possess significant bioactivity against a prion-infected cell line.