The large body size and high rates of metabolic heat production associated with male mating success in polygynous systems creates potential thermoregulatory challenges for species breeding in warm climates. This is especially true for marine predators carrying large blubber reserves intended for thermoregulation in cold water and fuel provision during extended fasts. Thermographic images were used to measure changes in skin temperature (T(S)) in adult male northern elephant seals (Mirounga angustirostris) over the breeding season.
View Article and Find Full Text PDFThe growing fetus depends upon transfer of glucose from maternal blood to fetal tissues. Insulin and glucocorticoid impact maternal glucose metabolism, but the effects of these hormones on fetal glucose assimilation in vivo are understudied. We thus used positron emission tomography imaging to determine the disposition of [(18)F]fluorodeoxyglucose (FDG) in rats on gestational d 20, quantifying the kinetic competition of maternal tissues and fetus for glucose.
View Article and Find Full Text PDFSignificant reduction in target strength and radiation signature can be achieved by surrounding an object with multiple concentric layers comprised of three acoustic fluids. The idea is to make a finely layered shell with the thickness of each layer defined by a unique transformation rule. The shell has the effect of steering incident acoustic energy around the structure, and conversely, reducing the radiation strength.
View Article and Find Full Text PDFMetastatic melanoma has a propensity for multiple intra cranial deposits. Rarely, metastatic melanoma to the pituitary gland has been reported, usually in conjunction with widespread systemic metastases. We describe a patient with metastatic melanoma to the pituitary gland as the first clinical presentation of widespread metastatic disease and review the relevant literature.
View Article and Find Full Text PDFThe rapidly activating and inactivating voltage-dependent outward K(+) (Kv) current, I(A), is widely expressed in central and peripheral neurons. I(A) has long been recognized to play important roles in determining neuronal firing properties and regulating neuronal excitability. Previous work demonstrated that Kv4.
View Article and Find Full Text PDFThe transcription factor NF-E2-related factor 2 (Nrf2) binds the antioxidant DNA response element (ARE) to activate important cellular cytoprotective defense systems. Recently several types of cancers have been shown to overexpress Nrf2, but its role in the cellular response to radiation therapy has yet to be fully determined. In this study, we report that single doses of ionizing radiation from 2 to 8 Gy activate ARE-dependent transcription in breast cancer cells in a dose-dependent manner, but only after a delay of five days.
View Article and Find Full Text PDFIntrauterine growth restriction (IUGR) is associated with altered lung development in human and rat. The transcription factor PPARγ, is thought to contribute to lung development. PPARγ is activated by docosahexanoic acid (DHA).
View Article and Find Full Text PDFConsiderable evidence indicates that native neuronal voltage-gated K+ (Kv) currents reflect the functioning of macromolecular Kv channel complexes, composed of pore-forming (α)-subunits, cytosolic and transmembrane accessory subunits, together with regulatory and scaffolding proteins. The individual components of these macromolecular complexes appear to influence the stability, the trafficking, the localization and/or the biophysical properties of the channels. Recent studies suggest that Kv channel accessory subunits subserve multiple roles in the generation of native neuronal Kv channels.
View Article and Find Full Text PDFIn budding yeast, silent chromatin is defined at the region of telomeres, rDNA loci, and silent mating loci. Although the silent chromatin at different loci shows structural similarity, the underlying mechanism to establish, maintain, and inherit these structures may be fundamentally different. In this study, we found two arginine residues within histone H2B, which are specifically required to maintain either the telomeric or the rDNA silenct chromatin.
View Article and Find Full Text PDFBackground: Complex but common maternal diseases such as diabetes and obesity contribute to adverse fetal outcomes. Understanding of the mechanisms involved is hampered by difficulty in isolating individual elements of complex maternal states in vivo. We approached this problem in the context of maternal diabetes and sought an approach to expose the developing fetus in vivo to isolated hyperglycemia in the pregnant rat.
View Article and Find Full Text PDFIn this work, the binding of coenzyme A (CoASH) to the aminoglycoside acetyltransferase (3)-IIIb (AAC) is studied by several experimental techniques. These data represent the first thermodynamic and kinetic characterization of interaction of a cofactor with an enzyme that modifies the 2-deoxystreptamine ring (2-DOS) common to all aminoglycoside antibiotics. Acetyl coenzyme A (AcCoA) was the preferred substrate, but propionyl and malonyl CoA were also substrates.
View Article and Find Full Text PDFThe thermodynamic and kinetic properties of interactions of antibiotics with the aminoglycoside acetyltransferase (3)-IIIb (AAC) are determined with several experimental methods. These data represent the first such characterization of an enzyme that modifies the 2-deoxystreptamine ring common to all aminoglycoside antibiotics. Antibiotic substrates for AAC include kanamycin A, kanamycin B, tobramycin, sisomicin, neomycin B, paromomycin, lividomycin A, and ribostamycin.
View Article and Find Full Text PDFThe rapidly activating and inactivating voltage-gated K(+) (Kv) current, I(A), is broadly expressed in neurons and is a key regulator of action potential repolarization, repetitive firing, backpropagation (into dendrites) of action potentials, and responses to synaptic inputs. Interestingly, results from previous studies on a number of neuronal cell types, including hippocampal, cortical, and spinal neurons, suggest that macroscopic I(A) is composed of multiple components and that each component is likely encoded by distinct Kv channel alpha-subunits. The goals of the experiments presented here were to test this hypothesis and to determine the molecular identities of the Kv channel alpha-subunits that generate I(A) in cortical pyramidal neurons.
View Article and Find Full Text PDFA recent explosion of work surrounds the interactions between Sir3p (Silent Information Regulator 3) and chromatin. We review here the Sir3p functions related to its role in silencing in Saccharomyces cerevisiae. This unusual protein, which is absolutely required for silencing, is distantly related to the highly conserved replication initiator Orc1p, but is itself phylogenetically limited to "post-genome-duplicated" budding yeasts.
View Article and Find Full Text PDFPurpose: Discovery of agents that protect or mitigate normal tissue from radiation injury during radiotherapy, accidents, or terrorist attacks is of importance. Specifically, bone marrow insufficiency, with possible infection due to immunosuppression, can occur after total body irradiation (TBI) or regional irradiation and is a major component of the acute radiation syndrome. The purpose of this study was to identify novel radioprotectors and mitigators of the hematopoietic system.
View Article and Find Full Text PDFThe aminoglycoside phosphotransferase(3')-IIIa (APH) is a promiscuous enzyme and renders a large number of structurally diverse aminoglycoside antibiotics useless against infectious bacteria. A remarkable property of this approximately 31 kDa enzyme is in its unusual dynamic behavior in solution; the apo-form of the enzyme exchanges all of its backbone amide protons within 15 h of exposure to D ( 2 ) O while aminoglycoside-bound forms retain approximately 40% of the amide protons even after >90 h of exposure. Moreover, the number of observable peaks and their dispersion in HSQC spectra varies with each aminoglycoside, rendering the resonance assignments very challenging.
View Article and Find Full Text PDFBackground: While many molecules involved in axon guidance have been identified, the cellular and molecular mechanisms by which these molecules regulate growth cone morphology during axon outgrowth remain to be elucidated. The actin cytoskeleton of the growth cone underlies the formation of lamellipodia and filopodia that control growth cone outgrowth and guidance. The role of the Arp2/3 complex in growth cone filopodia formation has been controversial, and other mechanisms of growth cone filopodia formation remain to be described.
View Article and Find Full Text PDFThis article proposes a strategic framework or road map for sustainable m-health. The drivers and critical success factors of this framework are identified from the literature and a survey of the views of senior strategists in the New Zealand health sector. The success factors are associated with key tasks in the framework that identify suitable applications, channel development activity, and confirm activity by continued support of innovation whilst moving successful applications into the mainstream.
View Article and Find Full Text PDFTwo widely discussed and debated aspects of health law literature are 'informed' consent to medical treatment and the right of access to personal health information. Both are tied to the larger subject of patients' rights, including the right to privacy. This article looks at the issue of informed consent internationally, and goes further to explain some of the inequalities across the world with respect to informed consent and patients' rights legislation via an analysis of the take-up of key legislative attributes in patient consent.
View Article and Find Full Text PDFThis project investigates public attitudes towards sharing confidential personal health information held in electronic health records (EHRs). The project uses computer assisted telephone interviewing (CATI) to conduct a quantitative national survey of the attitudes of New Zealanders towards access to their personal health information using vignettes. Respondents are presented with vignettes which describe ways in which their health information might be used, and asked about their attitude to and consent for each type of access.
View Article and Find Full Text PDFThis study examines alcohol use, transactional sex (TS), and sexually transmitted infection (STI) risk among sugar plantation residents near Moshi, Tanzania, from 2002 to 2004. We compare popular discourse gathered through ethnographic methods with cross-sectional questionnaire and STI prevalence data to illuminate the close correspondence of alcohol use and TS with STI transmission. People attributed to alcohol varied consequences: some socially desirable (relaxing, reducing worries) and others (drunkenness, removing shame) thought to put alcohol abusers at risk for STIs.
View Article and Find Full Text PDFAm J Med Genet C Semin Med Genet
August 2009
As genetic services grow in scope, issues of quality assessment in genetic services are emerging. These efforts are well developed for molecular and cytogenetic testing and laboratories, and newborn screening programs, but assessing quality in clinical services has lagged, perhaps owing to the small work force and the recent evolution from a few large training programs to multiple training sites. We surveyed the English language, peer-reviewed literature to summarize the knowledge-base of quality assessment of genetics services, organized into the tripartite categories of the Donabedian model of "structure," "process," and "outcome.
View Article and Find Full Text PDFThe activation and recruitment of CD4(+) T cells are critical for the development of efficient antitumor immunity and may allow for the optimization of current cancer immunotherapy strategies. Searching for more optimal and selective targets for CD4(+) T cells, we have investigated phosphopeptides, a new category of tumor-derived epitopes linked to proteins with vital cellular functions. Although MHC I-restricted phosphopeptides have been identified, it was previously unknown whether human MHC II molecules present phosphopeptides for specific CD4(+) T cell recognition.
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