109 research outputs found
Novel hepatoselective insulin analog
Cel pracy. Zbadanie, czy tyroksylowy analog insuliny z ograniczonym dostępem do receptora w tkankach obwodowych wykazuje względnie wybiórcze powinowactwo do wątroby u ludzi.
MATERIAŁ i metody. Pięć zdrowych osób otrzymywało podskórnie Na B1L-thyroksyl-insulinę (B1-T4-Ins) lub insulinę NPH w przypadkowej kolejności. Posługując się metodą klamry euglikemicznej i rozcieńczania znacznika izotopowego([D-6,6-2H2] glukozy), badano kinetykę insuliny oraz jej względny wpływ na wątrobową produkcję i obwodowy wychwyt glukozy. Pobierano próbki krwi w celu oznaczenia całkowitego stężenia insuliny immunoreaktywnej (bądź jej analogu) oraz w celu określenia stopnia wiązania analogu insuliny z białkami krwi, który badano metodą chromatografii cieczowej.
Wyniki. Po podskórnym podaniu B1-T4-Ins była dobrze tolerowana i szybko wchłaniana. Analog cechował się długim czasem półtrwania w surowicy oraz wysokim stopniem wiązania (ok. 86%) z białkami. Jego czas działania, mierzony czasem wlewu glukozy niezbędnym do utrzymania euglikemii, był podobny do czasu działania insuliny NPH. Wpływ analogu na wątrobową produkcję glukozy był podobny do wpływu insuliny NPH, co wskazuje na podobny stopień oddziaływania. Analog w mniejszym stopniu działał na obwodowy wychwyt insuliny w porównaniu z insuliną NPH (p = 0,025), nie wpływał na szybkość przemian metabolicznych glukozy oraz wykazywał zmniejszoną zdolność do hamowania lipolizy (p < 0,05).
Wnioski. U osób zdrowych B1-T4-Ins po podaniu podskórnym jest dobrze tolerowana, szybko się wchłania i ma wysoki stopień związania z białkami krwi, co odpowiada za długi czas połowicznego zaniku w surowicy. Analog ten wydaje się bardziej wybiórczy w oddziaływaniu na komórki wątroby, a zatem potencjalnie ma bardziej fizjologiczny profil działania w porównaniu z dotychczas stosowanymi preparatami insuliny.OBJECTIVE. To test whether a thyroxyl-insulin analog
with restricted access to receptor sites in peripheral
tissues displays relative hepatoselectivity in humans.
RESEARCH DESIGN AND METHODS. Five normal human
subjects received a subcutaneous bolus injection of
either N B1 L-thyroxyl-insulin (B1-T4-Ins) or NPH insulin
in random order. Insulin kinetics, relative effects on hepatic
glucose production, and peripheral glucose uptake
were studied using euglycemic clamp and stable isotope
[D-6,6-2H2]glucose) dilution techniques. Blood
samples were taken for the determination of total immunoreactive
insulin/analog concentrations and for liquid
chromatography to assess the protein binding of
the analog in the circulation.
RESULTS. After subcutaneous administration, B1-T4-Ins
was well tolerated and rapidly absorbed. The analog had
a long serum half-life and was highly protein bound
(~86%). Its duration of action, as judged by the duration
of infusion of exogenous glucose to maintain euglycemia,
was similar to that of NPH insulin. The effect of
the analogs on hepatic glucose production was similar
to that of NPH insulin, indicating equivalent hepatic potency.
The analog demonstrated less effect on peripheral glucose uptake than NPH insulin (P = 0,025), had no
effect on metabolic clearance rate of glucose, and exhibited
a reduced capacity to inhibit lipolysis (P < 0,05).
CONCLUSIONS. When injected subcutaneously into
normal human subjects, B1-T4-Ins is well tolerated,
quickly absorbed, and highly protein bound, resulting
in a long plasma half-life. This analog appears to have a
hepatoselective action, and, therefore, has the potential
to provide more physiological insulin action than
the insulin preparations currently used
p73 Regulates Neurodegeneration and Phospho-Tau Accumulation during Aging and Alzheimer's Disease
SummaryThe genetic mechanisms that regulate neurodegeneration are only poorly understood. We show that the loss of one allele of the p53 family member, p73, makes mice susceptible to neurodegeneration as a consequence of aging or Alzheimer's disease (AD). Behavioral analyses demonstrated that old, but not young, p73+/− mice displayed reduced motor and cognitive function, CNS atrophy, and neuronal degeneration. Unexpectedly, brains of aged p73+/− mice demonstrated dramatic accumulations of phospho-tau (P-tau)-positive filaments. Moreover, when crossed to a mouse model of AD expressing a mutant amyloid precursor protein, brains of these mice showed neuronal degeneration and early and robust formation of tangle-like structures containing P-tau. The increase in P-tau was likely mediated by JNK; in p73+/− neurons, the activity of the p73 target JNK was enhanced, and JNK regulated P-tau levels. Thus, p73 is essential for preventing neurodegeneration, and haploinsufficiency for p73 may be a susceptibility factor for AD and other neurodegenerative disorders
Association of Accelerometry-Measured Physical Activity and Cardiovascular Events in Mobility-Limited Older Adults: The LIFE (Lifestyle Interventions and Independence for Elders) Study.
BACKGROUND:Data are sparse regarding the value of physical activity (PA) surveillance among older adults-particularly among those with mobility limitations. The objective of this study was to examine longitudinal associations between objectively measured daily PA and the incidence of cardiovascular events among older adults in the LIFE (Lifestyle Interventions and Independence for Elders) study. METHODS AND RESULTS:Cardiovascular events were adjudicated based on medical records review, and cardiovascular risk factors were controlled for in the analysis. Home-based activity data were collected by hip-worn accelerometers at baseline and at 6, 12, and 24 months postrandomization to either a physical activity or health education intervention. LIFE study participants (n=1590; age 78.9±5.2 [SD] years; 67.2% women) at baseline had an 11% lower incidence of experiencing a subsequent cardiovascular event per 500 steps taken per day based on activity data (hazard ratio, 0.89; 95% confidence interval, 0.84-0.96; P=0.001). At baseline, every 30 minutes spent performing activities ≥500 counts per minute (hazard ratio, 0.75; confidence interval, 0.65-0.89 [P=0.001]) were also associated with a lower incidence of cardiovascular events. Throughout follow-up (6, 12, and 24 months), both the number of steps per day (per 500 steps; hazard ratio, 0.90, confidence interval, 0.85-0.96 [P=0.001]) and duration of activity ≥500 counts per minute (per 30 minutes; hazard ratio, 0.76; confidence interval, 0.63-0.90 [P=0.002]) were significantly associated with lower cardiovascular event rates. CONCLUSIONS:Objective measurements of physical activity via accelerometry were associated with cardiovascular events among older adults with limited mobility (summary score >10 on the Short Physical Performance Battery) both using baseline and longitudinal data. CLINICAL TRIAL REGISTRATION:URL: http://www.clinicaltrials.gov. Unique identifier: NCT01072500
Phase 1/2a Study of the Malaria Vaccine Candidate Apical Membrane Antigen-1 (AMA-1) Administered in Adjuvant System AS01B or AS02A
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79496.pdf (publisher's version ) (Open Access)BACKGROUND: This Phase 1/2a study evaluated the safety, immunogenicity, and efficacy of an experimental malaria vaccine comprised of the recombinant Plasmodium falciparum protein apical membrane antigen-1 (AMA-1) representing the 3D7 allele formulated with either the AS01B or AS02A Adjuvant Systems. METHODOLOGY/PRINCIPAL FINDINGS: After a preliminary safety evaluation of low dose AMA-1/AS01B (10 microg/0.5 mL) in 5 adults, 30 malaria-naive adults were randomly allocated to receive full dose (50 microg/0.5 mL) of AMA-1/AS01B (n = 15) or AMA-1/AS02A (n = 15), followed by a malaria challenge. All vaccinations were administered intramuscularly on a 0-, 1-, 2-month schedule. All volunteers experienced transient injection site erythema, swelling and pain. Two weeks post-third vaccination, anti-AMA-1 Geometric Mean Antibody Concentrations (GMCs) with 95% Confidence Intervals (CIs) were high: low dose AMA-1/AS01B 196 microg/mL (103-371 microg/mL), full dose AMA-1/AS01B 279 microg/mL (210-369 microg/mL) and full dose AMA-1/AS02A 216 microg/mL (169-276 microg/mL) with no significant difference among the 3 groups. The three vaccine formulations elicited equivalent functional antibody responses, as measured by growth inhibition assay (GIA), against homologous but not against heterologous (FVO) parasites as well as demonstrable interferon-gamma (IFN-gamma) responses. To assess efficacy, volunteers were challenged with P. falciparum-infected mosquitoes, and all became parasitemic, with no significant difference in the prepatent period by either light microscopy or quantitative polymerase chain reaction (qPCR). However, a small but significant reduction of parasitemia in the AMA-1/AS02A group was seen with a statistical model employing qPCR measurements. SIGNIFICANCE: All three vaccine formulations were found to be safe and highly immunogenic. These immune responses did not translate into significant vaccine efficacy in malaria-naive adults employing a primary sporozoite challenge model, but encouragingly, estimation of parasite growth rates from qPCR data may suggest a partial biological effect of the vaccine. Further evaluation of the immunogenicity and efficacy of the AMA-1/AS02A formulation is ongoing in a malaria-experienced pediatric population in Mali. TRIAL REGISTRATION: www.clinicaltrials.gov NCT00385047
Linkage to chromosome 2q32.2-q33.3 in familial serrated neoplasia (Jass syndrome)
Causative genetic variants have to date been identified for only a small proportion of familial colorectal cancer (CRC). While conditions such as Familial Adenomatous Polyposis and Lynch syndrome have well defined genetic causes, the search for variants underlying the remainder of familial CRC is plagued by genetic heterogeneity. The recent identification of families with a heritable predisposition to malignancies arising through the serrated pathway (familial serrated neoplasia or Jass syndrome) provides an opportunity to study a subset of familial CRC in which heterogeneity may be greatly reduced. A genome-wide linkage screen was performed on a large family displaying a dominantly-inherited predisposition to serrated neoplasia genotyped using the Affymetrix GeneChip Human Mapping 10 K SNP Array. Parametric and nonparametric analyses were performed and resulting regions of interest, as well as previously reported CRC susceptibility loci at 3q22, 7q31 and 9q22, were followed up by finemapping in 10 serrated neoplasia families. Genome-wide linkage analysis revealed regions of interest at 2p25.2-p25.1, 2q24.3-q37.1 and 8p21.2-q12.1. Finemapping linkage and haplotype analyses identified 2q32.2-q33.3 as the region most likely to harbour linkage, with heterogeneity logarithm of the odds (HLOD) 2.09 and nonparametric linkage (NPL) score 2.36 (P = 0.004). Five primary candidate genes (CFLAR, CASP10, CASP8, FZD7 and BMPR2) were sequenced and no segregating variants identified. There was no evidence of linkage to previously reported loci on chromosomes 3, 7 and 9
Spatializing the Ecological Leviathan: Territorial Strategies and the Production of Regional Natures
This paper explores a dual absence – the absence of the state within contemporary geographical analyses of nature; and the absence of nature within contemporary explorations of state power. We argue that the modern state continues to play a crucial role in framing social interactions with nature, while nature is still vital to states within their realization of different forms of material and ideological power. In order to reconnect analyses of the state and nature, this paper combines work on the production of nature and state strategy with Lefebvre’s recently translated writings on state space and territory. By focusing on the production of territory (or state space), we explore the interaction of the state and nature in the context of the political management of social and ecological space. We unravel the spatial entanglements of the state and nature through an analysis of the British state’s territorial strategies within the West Midlands region. By considering three key historical periods within the history of the West Mid-lands we reveal how the emergence of the regional space called the West Midlands is a product of the ongoing spatial dialectics of state and nature therein
Biological characteristics of a cold-adapted influenza A virus mutation residing on a polymerase gene
The biological function of a cold-adapted (ca) mutation residing on the PB2 gene of an influenza A/Ann Arbor/6/60 (A/AA/6/60) ca variant virus in the viral replication cycle at 25° C was studied. The viral polypeptide synthesis of A/AA/6/60 ca variant at 25° C was evident approximately 6 hours earlier than the wild type (wt) virus and yielded twice as many products. The quantitative analysis of viral complementary RNA (cRNA), synthesized in the presence of cycloheximide, revealed that A/AA/6/60 ca variant and a single gene reassortant that contains only the PB2 gene of the ca variant with remaining genes of the wt virus produced equal amount of cRNA at 25° and 33° C, which was an amount approximately four fold greater than the wt virus' cRNA synthesized at 25° C. These results strongly suggest that the ca mutation residing on the PB2 gene of A/AA/6/60 ca variant affects the messenger RNA synthesis at 25° C in the primary transcription.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41692/1/705_2005_Article_BF01310893.pd
The Somatic Genomic Landscape of Glioblastoma
We describe the landscape of somatic genomic alterations based on multi-dimensional and comprehensive characterization of more than 500 glioblastoma tumors (GBMs). We identify several novel mutated genes as well as complex rearrangements of signature receptors including EGFR and PDGFRA. TERT promoter mutations are shown to correlate with elevated mRNA expression, supporting a role in telomerase reactivation. Correlative analyses confirm that the survival advantage of the proneural subtype is conferred by the G-CIMP phenotype, and MGMT DNA methylation may be a predictive biomarker for treatment response only in classical subtype GBM. Integrative analysis of genomic and proteomic profiles challenges the notion of therapeutic inhibition of a pathway as an alternative to inhibition of the target itself. These data will facilitate the discovery of therapeutic and diagnostic target candidates, the validation of research and clinical observations and the generation of unanticipated hypotheses that can advance our molecular understanding of this lethal cancer
Retrospective evaluation of whole exome and genome mutation calls in 746 cancer samples
Funder: NCI U24CA211006Abstract: The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) curated consensus somatic mutation calls using whole exome sequencing (WES) and whole genome sequencing (WGS), respectively. Here, as part of the ICGC/TCGA Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium, which aggregated whole genome sequencing data from 2,658 cancers across 38 tumour types, we compare WES and WGS side-by-side from 746 TCGA samples, finding that ~80% of mutations overlap in covered exonic regions. We estimate that low variant allele fraction (VAF < 15%) and clonal heterogeneity contribute up to 68% of private WGS mutations and 71% of private WES mutations. We observe that ~30% of private WGS mutations trace to mutations identified by a single variant caller in WES consensus efforts. WGS captures both ~50% more variation in exonic regions and un-observed mutations in loci with variable GC-content. Together, our analysis highlights technological divergences between two reproducible somatic variant detection efforts
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