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1.
2.
Christopher Mayes 《Bioethics》2015,29(3):217-221
Debate concerning the social impact of obesity has been ongoing since at least the 1980s. Bioethicists, however, have been relatively silent. If obesity is addressed it tends to be in the context of resource allocation or clinical procedures such as bariatric surgery. However, prominent bioethicists Peter Singer and Dan Callahan have recently entered the obesity debate to argue that obesity is not simply a clinical or personal issue but an ethical issue with social and political consequences. This article critically examines two problematic aspects of Singer and Callahan's respective approaches. First, there is an uncritical assumption that individuals are autonomous agents responsible for health‐related effects associated with food choices. In their view, individuals are obese because they choose certain foods or refrain from physical activity. However, this view alone does not justify intervention. Both Singer and Callahan recognize that individuals are free to make foolish choices so long as they do not harm others. It is at this point that the second problematic aspect arises. To interfere legitimately in the liberty of individuals, they invoke the harm principle. I contend, however, that in making this move both Singer and Callahan rely on superficial readings of public health research to amplify the harm caused by obese individuals and ignore pertinent epidemiological research on the social determinants of obesity. I argue that the mobilization of the harm principle and corresponding focus on individual behaviours without careful consideration of the empirical research is itself a form of harm that needs to be taken seriously. 相似文献
3.
The effect of chylomicron remnants on bile acid synthesis in isolated rat hepatocytes in monolayer cultures was investigated. Production of bile acids by the cells in the presence of chylomicron remnants at a cholesterol concentration of 7.8-9 nmol/ml was increased by approx. 75% after 17 h and 25% after 24 h incubation. Similar concentrations of cholesterol added to the cells in the form of chylomicrons had no significant effect on bile acid synthesis. These results suggest that cholesterol taken up in chylomicron remnants may be an important source of substrate for bile acid synthesis. 相似文献
4.
Nucleotide sequencing of the second Synechocystis 6803 psbG gene, psbG2 shows the predicted polypeptide to be 219 amino acids long. It is less similar to chloroplast psbG genes than is the Synechocystis psbG1 copy. Alignment with seven other psbG protein sequences, including that from the Paramecium mitochondrial genome reveals a central highly conserved region common to each. This is discussed as evidence supporting the proposal that the psbG polypeptide is a NAD(P)H dehydrogenase (complex I) subunit in cyanobacteria, chloroplasts and mitochondria. 相似文献
5.
Ryan K. Cheu Andrew T. Gustin Christina Lee Luca Schifanella Charlene J. Miller Avie Ha Casey Kim Violeta J. Rodriguez Margaret Fischl Adam D. Burgener Kelly B. Arnold Maria L. Alcaide Nichole R. Klatt 《PLoS pathogens》2020,16(12)
Despite the efficacy of antiretroviral-based pre-exposure prophylactics (PrEP) in men who have sex with men, studies in women have produced widely varying outcomes. Recent evidence demonstrates that vaginal microbial communities are associated with increased HIV acquisition risk and may impact PrEP efficacy. Here, we investigate the mechanisms underlying how vaginal bacteria alter PrEP drug levels and impact HIV infection rates ex vivo. Using cervicovaginal lavages (CVLs) from women with or without bacterial vaginosis (BV), we identified microbial metabolism of PrEP drugs in BV samples through LC-MS/MS analysis of soluble drug levels and metabolite formation in dual T-cell cultures. CVL samples were assessed for microbiome analysis using sequencing of bacterial 16S rRNA genes. We also observed non-Lactobacillus bacteria that are associated with BV may potentially impact PrEP efficacy through increased HIV infection rates in co-cultures containing Lactobacillus or BV bacteria, PrEP drugs, CEM-GFP cells, and HIV-1LAI virus. Finally, we used these data to develop a novel predictive mathematical simulation modeling system to predict these drug interactions for future trials. These studies demonstrate how dysbiotic vaginal microbiota may impact PrEP drugs and provides evidence linking vaginal bacteria to PrEP efficacy in women. 相似文献
6.
Charlene P. Wight Andrew J. Daugulis Reginald H. Lau Bradley N. White 《Applied microbiology and biotechnology》1989,31(4):338-341
Summary
Bacillus brevis 47 was cultivated in 2-1 fermentors to study the effect of medium supplementation on extracellular protein production. Additional polypeptone, when supplied initially or at 12 h (late exponential phase), had little stimulatory effect on extracellular protein levels, which reached 6–7 g/l after 48h. A large increase in protein production was observed, however, when polypeptone was added at 21 h (stationary phase). This addition resulted in the accumulation in the medium of 14 g/l protein after 48 h, and a total of 16 g/l when cell-bound protein was included. In all cases, glucose was consumed only very slowly. 相似文献
7.
Charlene M. Hogan Mary Mes-Hartree John N. Saddler Donn J. Kushner 《Applied microbiology and biotechnology》1990,32(5):614-620
Summary The enzyme loading needed to achieve substrate saturation appeared to be the most economical enzyme concentration to use for hydrolysis, based on percentage hydrolysis. Saturation was reached at 25 filter paper units per gram substrate on Solka Floc BW300, as determined by studying (a) initial adsorption of the cellulase preparation onto the substrate, (b) an actual hydrolysis or (c) a combined hydrolysis and fermentation (CHF) process. Initial adsorption of the cellulases onto the substrate can be used to determine the minimal cellulase requirements for efficient hydrolysis since enzymes initially adsorbed to the substrate have a strong role in governing the overall reaction. Trichoderma harzianum E58 produces high levels of -glucosidase and is able to cause high conversion of Solka Floc BW300 to glucose without the need for exogenous -glucosidase. End-product inhibition of the cellulase and -glucosidase can be more effectively reduced by employing a CHF process than by supplemental -glucosidase.Offprint requests to: C. M. Hogan 相似文献
8.
Charlene Chang Ben A. Moll Kathleen B. Evenson Mark J. Guiltinan 《Plant Cell, Tissue and Organ Culture》1996,45(1):61-66
In vitro plantlet regeneration systems for the seed geranium (Pelargonium x hortorum Bailey) using cotyledon, hypocotyl and root explants were optimized by studying the influence of seedling age, growth regulators and excision orientation on organogenesis. Indole-3-acetic acid combined with zeatin yielded the highest rate of shoot production on cotyledon explants (0.2–2 shoots per explant). More shoots were produced on explants cut from the most basal region of cotyledons from 2 to 4-day-old seedlings than from older seedlings or more distal cut sites. Hypocotyl explants produced the highest number of shoots, up to 40 shoots per explant, on indole-3-acetic acid (2.8–5.6 mM) + zeatin (4.6 mM) or thidiazuron (4.5 mM). Maximum shoot formation (0.3–1.4 shoots per explant) on root explants occurred when they were cultured on medium containing zeatin. Regenerated shoots rooted best on a basal medium containing no growth regulators. There were substantial differences among cultivars in shoot formation from each of the explant systems.Abbreviations BA
6-benzylaminopurine
- 2,4-d
2,4-dichlorophenoxyacetic acid
- IAA
indole-3-acetic acid
- NAA
naphthaleneacetic acid
- TDZ
thidiazuron 相似文献
9.
R. W. Mayes N. A. Beresford B. J. Howard C. M. Vandecasteele G. Stakelum 《Radiation and environmental biophysics》1996,35(2):101-109
Limitations of existing methods to describe the bioavailability of dietary radionuclides to ruminants (the transfer coefficient
and apparent absorption coefficient) have led to the alternative suggestion of using the true absorption coefficient (A
t). Various approaches to estimatingA
t for radiocaesium, involving the intravenous administration of a second isotope, are presented and discussed with reference
to results from studies in which a range of radiocaesium sources were examined in sheep. Although estimates ofA
t differed between the sources, they were reasonably consistent between measurement techniques. Those methods which involved
the estimation of endogenous faecal excretion of radiocaesium could be used with previously contaminated animals and did not
require continuous administrations of radiocaesium isotopes, but gave unreliable results for sources of low bioavailability.
Methods based on estimating the turnover rate of dietary radiocaesium through blood plasma were sufficiently sensitive to
measureA
t for the range of sources studied. However, they require previously uncontaminated animals and continuous administration of
both isotopes for approximately 7 days. Bioavailability is more effectively measured asA
t than as the transfer or apparent absorption coefficients sinceA
t does not incorporate factors relating to the metabolism of radiocaesium in the tissues of the animal. The results of these
studies show that differences in transfer coefficients between sheep and cattle and between sheep of differing ages are not
due to variation in absorption across the gut. The potential for applying these approaches to other radioactive elements is
discussed. 相似文献
10.
Martina Ferraguti Sergio Magallanes Jéssica Jiménez-Peñuela Josué Martínez-de la Puente Luz Garcia-Longoria Jordi Figuerola Jaime Muriel Tamer Albayrak Staffan Bensch Camille Bonneaud Rohan H. Clarke Gábor Á. Czirják Dimitar Dimitrov Kathya Espinoza John G. Ewen Farah Ishtiaq Wendy Flores-Saavedra László Zsolt Garamszegi Olof Hellgren Dita Horakova Kathryn P. Huyvaert Henrik Jensen Asta Križanauskienė Marcos R. Lima Charlene Lujan-Vega Eyðfinn Magnussen Lynn B. Martin Kevin D. Matson Anders Pape Møller Pavel Munclinger Vaidas Palinauskas Péter L. Pap Javier Pérez-Tris Swen C. Renner Robert Ricklefs Sergio Scebba Ravinder N. M. Sehgal Manuel Soler Eszter Szöllősi Gediminas Valkiūnas Helena Westerdahl Pavel Zehtindjiev Alfonso Marzal 《Global Ecology and Biogeography》2023,32(5):809-823