Synthesis of 18-substituted steroids Part II (1). Improvements in the preparation of 18-hydroxyprogesterone.

18-Hydroxyprogesterone is conveniently prepared from 3beta-acetoxypregn-5-en-20beta-ol by a modified route. 3beta-Acetoxy-18-iodopregn-5-en-20-one, obtained by the hypoiodite-photolysis procedure and oxidation, is treated with methanolic silver acetate to give the 18, 20-epoxy-20-methoxy derivative, which crystallises directly without need for chromatography. Hydrolysis of the 3-acetate, and a modified Oppenauer oxidation, gave 18-hydroxy-progesterone in 24% over-all yield.     

Reduction of oxygen by the electron transport chain of chloroplasts during assimilation of carbon dioxide

In photosynthetically competent chloroplasts from spinach the quantum requirements for oxygen evolution during CO₂ reduction were higher, by a factor often close to 1.5, than for oxygen evolution during reduction of phosphoglycerate. Mass spectrometer experiments performed under rate-limiting light indicated that an oxygen-reducing photoreaction was responsible for the consumption of extra quanta during carbon dioxide assimilation. Uptake of ¹⁸O₂ during reduction of CO₂ was considerably higher than could be accounted for by oxygen consumption during glycolate formation and by the Mehler reaction of broken chloroplasts which were present in the preparations of intact chloroplasts. The oxygen reducing reaction occurring during CO₂ assimilation resulted in the formation of H₂O₂. This was indicated by a large stimulation of CO₂ reduction by catalase, but not of phosphoglycerate reduction. Catalase could be replaced as a stimulant of photosynthesis by dithiothreitol or ascorbate, compounds known to react with superoxide radicals. There was no effect of dithiothreitol and ascorbate on phosphoglycerate reduction. A main effect of superoxide radicals and/or H₂O₂ was shown to be at the level of phosphoglycerate formation. Evidence for electron transport to oxygen was also obtained from ¹⁴CO₂ experiments. The oxidation of dihydroxyacetonephosphate during a dark period or after addition of carbonyl cyanide p-trifluoromethoxyphenylhydrazone in the light was studied. The results indicated a link between the chloroplast pyridine nucleotide system and oxygen. Oxygen reduction during photosynthesis under conditions where light is rate limiting is seen as important in supplying the ATP which is needed for CO₂ reduction but is not provided during electron transport to NADP. A mechanism is discussed which would permit proper distribution of electrons between CO₂ and oxygen during photosynthesis.     

Quantitative effects of common genetic variations in the 3′UTR of the human LDL-receptor gene and their associations with plasma lipid levels in the Atherosclerosis Risk in Communities study

The low-density lipoprotein receptor (LDLR) plays a pivotal role in cholesterol homeostasis. However, the role of genetic variations in the 3′UTR of the LDLR in relation to plasma cholesterol has been largely understudied. Six SNPs, G44243A, G44332A, C44506G, G44695A, C44857T and A44964G, within the 5′ region of the 3′UTR fall into three common haplotypes, GGCGCA, AGCACG, and GGCGTA, occurring at frequencies of 0.45, 0.31 and 0.17, respectively, in Caucasians (n = 29) and 0.13, 0.13 and 0.38, respectively, in African Americans (n = 32), with three other haplotypes occurring at lesser frequencies. In a tissue culture based system, expression of a reporter gene carrying a 3′UTR that includes the 1 kb nucleotide sequences corresponding to the AGCACG or GGCGTA was 70 or 63%, respectively, of the same sequence with GGCGCA. Genotyping of two “haplotype tagging” SNPs, C44857T and A44964G, in the Atherosclerosis Risk in Communities (ARIC) study population showed that in Caucasians, but not in African Americans, the inferred TA haplotype had a significant LDL-cholesterol lowering effect. The adjusted LDL-cholesterol levels in the TA/TA diplotypes were lower by 6.10 mg/dl in men (P < 0.001) and by 4.63 mg/dl in women (P < 0.01) than in individuals with other diplotypes. Caucasian men homozygous for CA, in contrast, showed significantly higher LDL-cholesterol (P < 0.04), lower HDL-cholesterol (P < 0.02) and higher LDL/HDL ratios (P < 0.001). Thus our data shows that 3′UTR sequences that cause higher reporter gene expression in vitro are associated in Caucasians with plasma lipid profiles indicative of higher cardiovascular risk, suggesting that further studies of quantitative variants in the LDLR gene will be valuable. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. An erratum to this article can be found at     

Protein kinase C delta null mice exhibit structural alterations in articular surface,intra-articular and subchondral compartments

IntroductionStructural alterations in intra-articular and subchondral compartments are hallmarks of osteoarthritis, a degenerative disease that causes pain and disability in the aging population. Protein kinase C delta (PKC-δ) plays versatile functions in cell growth and differentiation, but its role in the articular cartilage and subchondral bone is not known.MethodsHistological analysis including alcian blue, safranin O staining and fluorochrome labeling were used to reveal structural alterations at the articular cartilage surface and bone–cartilage interface in PKC-δ knockout (KO) mice. The morphology and organization of chondrocytes were studied using confocal microscopy. Glycosaminoglycan content was studied by micromass culture of chondrocytes of PKC-δ KO mice.ResultsWe uncovered atypical structural demarcation between articular cartilage and subchondral bone of PKC-δ KO mice. Histology analyses revealed a thickening of the articular cartilage and calcified bone–cartilage interface, and decreased safranin O staining accompanied by an increase in the number of hypertrophic chondrocytes in the articular cartilage of PKC-δ KO mice. Interestingly, loss of demarcation between articular cartilage and bone was concomitant with irregular chondrocyte morphology and arrangement. Consistently, in vivo calcein labeling assay showed an increased intensity of calcein labeling in the interface of the growth plate and metaphysis in PKC-δ KO mice. Furthermore, in vitro culture of chondrocyte micromass showed a decreased alcian blue staining of chondrocyte micromass in the PKC-δ KO mice, indicative of a reduced level of glycosaminoglycan production.ConclusionsOur data imply a role for PKC-δ in the osteochondral plasticity of the interface between articular cartilage and the osteochondral junction.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-015-0720-4) contains supplementary material, which is available to authorized users.     

Repeated insemination in Michigan Holstein-Friesian cattle: Incidence, descriptive epidemiology and estimated economic impact

Twenty-two Michigan dairy herds participating in a computerized herd-health program were studied to determine the incidence and epidemiologic characteristics of repeat-breeder syndrome. A cow with repeat-breeder syndrome was defined as having been inseminated three or more times within the same lactation. Repeat-breeder syndrome was observed in 24% of 3,309 lactations. Cost components associated with unsuccessful inseminations included costs of delayed conception, extra inseminations, extra veterinary service and losses due to culling. Lactations with repeat-breeder syndrome were associated with a loss of approximately $385. An estimated extra cost of $140 was associated with a second insemination, $279 with three inseminations, $429 with four inseminations and $612 with five inseminations.     

Expression and Antimicrobial Function of Beta-Defensin 1 in the Lower Urinary Tract

Beta defensins (BDs) are cationic peptides with antimicrobial activity that defend epithelial surfaces including the skin, gastrointestinal, and respiratory tracts. However, BD expression and function in the urinary tract are incompletely characterized. The purpose of this study was to describe Beta Defensin-1 (BD-1) expression in the lower urinary tract, regulation by cystitis, and antimicrobial activity toward uropathogenic Escherichia coli (UPEC) in vivo. Human DEFB1 and orthologous mouse Defb1 mRNA are detectable in bladder and ureter homogenates, and human BD-1 protein localizes to the urothelium. To determine the relevance of BD-1 to lower urinary tract defense in vivo, we evaluated clearance of UPEC by Defb1 knockout (Defb1 ^-/-) mice. At 6, 18, and 48 hours following transurethral UPEC inoculation, no significant differences were observed in bacterial burden in bladders or kidneys of Defb1 ^-/- and wild type C57BL/6 mice. In wild type mice, bladder Defb1 mRNA levels decreased as early as two hours post-infection and reached a nadir by six hours. RT-PCR profiling of BDs identified expression of Defb3 and Defb14 mRNA in murine bladder and ureter, which encode for mBD-3 and mBD-14 protein, respectively. MBD-14 protein expression was observed in bladder urothelium following UPEC infection, and both mBD-3 and mBD-14 displayed dose-dependent bactericidal activity toward UPEC in vitro. Thus, whereas mBD-1 deficiency does not alter bladder UPEC burden in vivo, we have identified mBD-3 and mBD-14 as potential mediators of mucosal immunity in the lower urinary tract.     

Are Sage-Grouse Fine-Scale Specialists or Shrub-Steppe Generalists?

Sage-grouse (Centrocercus spp.) are influencing rapidly evolving land management policy in the western United States. Management objectives for fine-scale vegetation characteristics (e.g., grass height >18 cm) have been adopted by land management agencies based on resource selection or relationships with fitness proxies reported among numerous habitat studies. Some managers, however, have questioned the appropriateness of these objectives. Moreover, it remains untested whether habitat–fitness relationships documented at fine scales (i.e., among individual nests within a study area) also apply at scales of management units (e.g., pastures or grazing allotments), which are many orders of magnitude larger. We employed meta-analyses of studies published from 1991 to 2019 to help resolve the role of fine-scale vegetation structure in nest site selection and nest success across the geographic range of greater sage-grouse (C. urophasianus) and evaluate the validity of established habitat management objectives. Specifically, we incorporated effects of study design and functional responses to resource availability in meta-regression models linking vegetation structure to nest site selection, and used a novel meta-analytic approach to simultaneously model vegetation structure and its relationship to nest success. Our approach tested habitat relationships at a range-wide extent and a grain size closely matching scales at which agencies make management decisions. We found moderate, but context-dependent, effects of shrub characteristics and weak effects of herbaceous vegetation on nest site selection. None of the tested vegetation characteristics were related to variation in nest success, suggesting nesting habitat–fitness relationships have been inappropriately extrapolated in developing range-wide habitat management objectives. Our findings reveal surprising flexibility in habitat use for a species often depicted as having very particular fine-scale habitat requirements, and cast doubt on the practice of adopting precise management objectives for vegetation structure based on findings of individual small-scale field studies. © 2020 The Authors. The Journal of Wildlife Management published by Wiley Periodicals, Inc. on behalf of The Wildlife Society.     

Raccoon Pelt Price and Trapper Harvest Relationships Are Temporally Inconsistent

Trapping data have a long and rich history of use in monitoring furbearer populations in North America but understanding the influences of variation in trapper harvest is important. Many factors besides abundance can cause variation in trapper harvest, including socioeconomics, weather, and motivation. The relationships between these extrinsic factors and trapper harvest may change temporally, which may obscure the causal understanding of variation in trapper harvest. We tested for changes in the relationships between pelt price and trapper numbers, and pelt price and harvest per trapper for raccoons (Procyon lotor) in Illinois, USA, from 1976–2018 while controlling for other socioeconomic (gasoline price, unemployment) and weather (temp, snow depth) factors. The annual raccoon harvest showed no clear trend, whereas the number of raccoon trappers declined markedly from approximately 1976–1990 in conjunction with pelt prices, after which the number of trappers remained relatively stable and were not significantly affected by pelt price. In contrast, harvest per trapper increased markedly during the 1990s and showed a significant negative relationship with pelt price pre-1990 but a positive relationship post-1990. We propose that declines in pelt prices resulted in a loss of less experienced or economically incentivized trappers, whereas contemporary trappers may continue trapping primarily for non-economic reasons. Our study highlights the potential for using non-linear relationships between trapper harvest data and socioeconomic covariates to help understand the influences of temporal variation in trapper harvest data. © 2020 The Wildlife Society.