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81.
Effects of atrial natriuretic factor in conscious rhesus monkeys with acute volume expansion 总被引:1,自引:0,他引:1
The renal and hemodynamic responses to intravenous anaritide, a human atrial natriuretic factor [102-126] at 0.3 to 20 micrograms/kg in conscious rhesus monkeys with and without acute extracellular hypervolemia were analyzed and compared. Acute isotonic saline loading (intravenous bolus at 10 mL/kg plus continuous infusion at 0.25 mL/kg/min 30 min prior to and maintained throughout experiment) significantly augmented urine output (UV) and urinary Na+ excretion rate (UNaV) by 31% and 91%, respectively. Radial mean arterial pressure (MAP) and heart rate (HR) were not affected by volume expansion. Anaritide at doses higher than 0.3 micrograms/kg reduced MAP in a dose-dependent fashion in euvolemic monkeys. In contrast, reduction in MAP was observed only at the highest dose (20 micrograms/kg) of anaritide in hypervolemic monkeys. The hypotensive responses to anaritide at 20 micrograms/kg in euvolemic and hypervolemic animals were similar (-26 +/- 5 v -24 +/- 5 mm Hg, respective maximum changes in MAP). UV and UNaV were increased by anaritide at 3 to 20 micrograms/kg in both euvolemic and hypervolemic monkeys; however, the increases at each effective dose of anaritide were greater or tended to be greater in hypervolemic rhesus monkeys compared with euvolemic rhesus monkeys. Compared to vehicle responses, HR was not affected by anaritide in either group of animals. In conclusion, acute extracellular hypervolemia potentiates the renal but suppresses the hypotensive responses to anaritide in conscious rhesus monkeys. 相似文献
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D P Figlewicz D M Dorsa L J Stein D G Baskin T Paquette M R Greenwood S C Woods D Porte 《Endocrinology》1985,117(4):1537-1543
Insulin binding was measured in membrane particles prepared from the liver and several brain regions of 4-month-old female Zucker fa/fa (obese), Fa/fa (heterozygous), and Fa/Fa (lean) rats. High affinity insulin binding was decreased in the olfactory bulb of fatty (0.23 pmol bound/mg protein) and heterozygous (0.16 pmol/mg) rats compared with that in the lean controls (0.64 pmol/mg). Total binding was not changed in the cerebral cortex or hypothalamus. High affinity insulin binding was also decreased in the liver of both fatty (0.44 +/- 0.22 pmol/mg; P less than 0.01) and heterozygous (0.75 +/- 0.35 pmol/mg) animals compared with that in the lean rats (2.10 +/- 1.55 pmol/mg). This decreased binding is probably not due to down-regulation of receptors in the heterozygous rats, as they do not exhibit the hyperinsulinemia observed in the fatty rats. Rather, our findings suggest that there is a gene-related alteration in insulin binding in the Zucker rat, as low binding was observed in rats carrying either one (Fa/fa) or two (fa/fa) doses of the gene. We postulate that this central defect in insulin binding may contribute to inadequate perception of a central insulin feedback signal and to the hyperphagia observed in the obese rats. 相似文献
85.
John D. Biglands Montasir Ibraheem Derek R. Magee Aleksandra Radjenovic Sven Plein John P. Greenwood 《JACC: Cardiovascular Imaging》2018,11(5):711-718
Objectives
This study sought to compare the diagnostic accuracy of visual and quantitative analyses of myocardial perfusion cardiovascular magnetic resonance against a reference standard of quantitative coronary angiography.Background
Visual analysis of perfusion cardiovascular magnetic resonance studies for assessing myocardial perfusion has been shown to have high diagnostic accuracy for coronary artery disease. However, only a few small studies have assessed the diagnostic accuracy of quantitative myocardial perfusion.Methods
This retrospective study included 128 patients randomly selected from the CE-MARC (Clinical Evaluation of Magnetic Resonance Imaging in Coronary Heart Disease) study population such that the distribution of risk factors and disease status was proportionate to the full population. Visual analysis results of cardiovascular magnetic resonance perfusion images, by consensus of 2 expert readers, were taken from the original study reports. Quantitative myocardial blood flow estimates were obtained using Fermi-constrained deconvolution. The reference standard for myocardial ischemia was a quantitative coronary x-ray angiogram stenosis severity of ≥70% diameter in any coronary artery of >2 mm diameter, or ≥50% in the left main stem. Diagnostic performance was calculated using receiver-operating characteristic curve analysis.Results
The area under the curve for visual analysis was 0.88 (95% confidence interval: 0.81 to 0.95) with a sensitivity of 81.0% (95% confidence interval: 69.1% to 92.8%) and specificity of 86.0% (95% confidence interval: 78.7% to 93.4%). For quantitative stress myocardial blood flow the area under the curve was 0.89 (95% confidence interval: 0.83 to 0.96) with a sensitivity of 87.5% (95% confidence interval: 77.3% to 97.7%) and specificity of 84.5% (95% confidence interval: 76.8% to 92.3%). There was no statistically significant difference between the diagnostic performance of quantitative and visual analyses (p = 0.72). Incorporating rest myocardial blood flow values to generate a myocardial perfusion reserve did not significantly increase the quantitative analysis area under the curve (p = 0.79).Conclusions
Quantitative perfusion has a high diagnostic accuracy for detecting coronary artery disease but is not superior to visual analysis. The incorporation of rest perfusion imaging does not improve diagnostic accuracy in quantitative perfusion analysis. 相似文献86.
Tiffany A. Greenwood Judith A. Badner William Byerley Paul E. Keck Susan L. McElroy Ronald A. Remick A. Dessa Sadovnick John R. Kelsoe 《Journal of affective disorders》2013
Background
The many attempts that have been made to identify genes for bipolar disorder (BD) have met with limited success, which may reflect an inadequacy of diagnosis as an informative and biologically relevant phenotype for genetic studies. Here we have explored aspects of personality as quantitative phenotypes for bipolar disorder through the use of the Temperament and Character Inventory (TCI), which assesses personality in seven dimensions. Four temperament dimensions are assessed: novelty seeking (NS), harm avoidance (HA), reward dependence (RD), and persistence (PS). Three character dimensions are also included: self-directedness (SD), cooperativeness (CO), and self-transcendence (ST).Methods
We compared personality scores between diagnostic groups and assessed heritability in a sample of 101 families collected for genetic studies of BD. A genome-wide SNP linkage analysis was then performed in the subset of 51 families for which genetic data was available.Results
Significant group differences were observed between BD subjects, their first-degree relatives, and independent controls for all but RD and PS, and all but HA and RD were found to be significantly heritable in this sample. Linkage analysis of the heritable dimensions produced several suggestive linkage peaks for NS (chromosomes 7q21 and 10p15), PS (chromosomes 6q16, 12p13, and 19p13), and SD (chromosomes 4q35, 8q24, and 18q12).Limitations
The relatively small size of our linkage sample likely limited our ability to reach genome-wide significance in this study.Conclusions
While not genome-wide significant, these results suggest that aspects of personality may prove useful in the identification of genes underlying BD susceptibility. 相似文献87.
Samantha J. Broyd Lisa-marie Greenwood Rodney J. Croft Anna Dalecki Juanita Todd Patricia T. Michie Stuart J. Johnstone Nadia Solowij 《International journal of psychophysiology》2013
Chronic cannabis use has been associated with neurocognitive deficits, alterations in brain structure and function, and with psychosis. This study investigated the effects of chronic cannabis use on P50 sensory-gating in regular users, and explored the association between sensory gating, cannabis use history and the development of psychotic-like symptoms. Twenty controls and 21 regular cannabis users completed a P50 paired-click (S1 and S2) paradigm with an inter-pair interval of 9 s. The groups were compared on P50 amplitude to S1 and S2, P50 ratio (S2/S1) and P50 difference score (S1–S2). While cannabis users overall did not differ from controls on P50 measures, prolonged duration of regular use was associated with greater impairment in sensory gating as indexed by both P50 ratio and difference scores (including after controlling for tobacco use). Long-term cannabis users were found to have worse sensory gating ratios and difference scores compared to short-term users and controls. P50 metrics did not correlate significantly with any measure of psychotic-like symptoms in cannabis users. These results suggest that prolonged exposure to cannabis results in impaired P50 sensory-gating in long-term cannabis users. While it is possible that these deficits may have pre-dated cannabis use and reflect a vulnerability to cannabis use, their association with increasing years of cannabis use suggests that this is not the case. Impaired P50 sensory-gating ratios have also been reported in patients with schizophrenia and may indicate a similar underlying pathology. 相似文献
88.
Joseph M. Rutkowski Jong Eun Ihm Seung Tae Lee Witold W. Kilarski Veronique I. Greenwood Miriella C. Pasquier Alexandra Quazzola Didier Trono Jeffrey A. Hubbell Melody A. Swartz 《The American journal of pathology》2013,183(5):1596-1607
Lymphatic vessels surround follicles within the ovary, but their roles in folliculogenesis and pregnancy, as well as the necessity of lymphangiogenesis in follicle maturation and health, are undefined. We used systemic delivery of mF4-31C1, a specific antagonist vascular endothelial growth factor receptor 3 (VEGFR-3) antibody to block lymphangiogenesis in mice. VEGFR-3 neutralization for 2 weeks before mating blocked ovarian lymphangiogenesis at all stages of follicle maturation, most notably around corpora lutea, without significantly affecting follicular blood angiogenesis. The numbers of oocytes ovulated, fertilized, and implanted in the uterus were normal in these mice; however, pregnancies were unsuccessful because of retarded fetal growth and miscarriage. Fewer patent secondary follicles were isolated from treated ovaries, and isolated blastocysts exhibited reduced cell densities. Embryos from VEGFR-3–neutralized dams developed normally when transferred to untreated surrogates. Conversely, normal embryos transferred into mF4-31C1–treated dams led to the same fetal deficiencies observed with in situ gestation. Although no significant changes were measured in uterine blood or lymphatic vascular densities, VEGFR-3 neutralization reduced serum and ovarian estradiol concentrations during gestation. VEGFR-3–mediated lymphangiogenesis thus appears to modulate the folliculogenic microenvironment and may be necessary for maintenance of hormone levels during pregnancy; both of these are novel roles for the lymphatic vasculature.Ovarian neovascularization provides a unique environment in which to study physiological adult vasculogenesis apart from the traditional settings of wound healing and cancer pathologies. Lymphatic circulation plays a central role in fluid, lipid, and cellular transport,1 and lymphatic vessels are present within the ovary and surround follicles during development and maturation,2–5 but the importance of the lymphatic vasculature and lymphangiogenesis in the ovary is unclear. Consequently, the potential roles of lymphatic vessels in follicle maturation and pregnancy, and the extent of involvement or even necessity of maternal lymphangiogenesis in reproduction, are undefined. This contrasts with ovarian blood angiogenesis, whose critical roles in follicular nourishment and maturation and in the formation and maintenance of the corpus luteum are well appreciated; indeed, oocyte fertilization, embryonic implantation, uterine expansion, and successful gestation all require blood angiogenesis.6–8 Lymphangiogenesis, which is often concurrent with blood angiogenesis,9 may also play an important role in these processes.Adult blood angiogenesis requires signaling via vascular endothelial growth factor receptor 2 (VEGFR-2), most potently by VEGF ligation.10,11 In murine ovaries, VEGF expression increases during angiogenic growth phases,12 and blockade of VEGFR-2 signaling in mice effectively prevents angiogenesis, resulting in a marked decrease in ovarian weight, blood vessel density, and number of corpora lutea, and in infertility.13–15 Because gonadotropin treatment apparently does not correct these deficiencies,16 it is likely that follicle maturation and successful pregnancy are highly dependent on VEGFR-2–mediated neovascularization in the ovary.6,17 Vascularization also occurs in the uterine wall and decidua during pregnancy, and significant disruption of angiogenesis by VEGFR-2 blockade in these tissues after fertilization has been shown to greatly reduce pregnancy success.18VEGFR-3 is expressed primarily on lymphatic endothelial cells in adult tissue,19,20 and its signaling, via ligation by VEGF-C or VEGF-D, is necessary for lymphangiogenesis by inducing lymphatic endothelial cell proliferation and migration.19–23 Blockade of VEGFR-3 signaling using a function-blocking antibody such as mF4-31C1 (ImClone Systems; Eli Lilly, Indianapolis, IN) completely blocks the initiation of new lymphatic vessels in adult mice without affecting pre-existing lymphatic morphology or function and without apparently affecting blood angiogenesis.18,21,22 The ovary contains a dense lymphatic network that has been morphologically assessed in large rodents.24–26 Recent studies in which murine ovarian lymphatic vessel expansion was impaired during development found the dams to be infertile as adults.3We investigated VEGFR-3–mediated lymphangiogenesis and the roles of new lymphatic vessels and lymphangiogenesis in female reproduction and found that lymphangiogenesis occurs within the murine ovary during reproductive cycles and folliculogenesis and that VEGFR-3 neutralization prevents viable, full-term pregnancies. Using combined in vivo, ex vivo, and in vitro methods, we examined which aspects of female fertility are influenced by inhibited maternal lymphangiogenesis including oocyte and follicular development and maturation, uterine implantation, and embryonic development. After we had eliminated direct effects on fetal and uterine VEGFR-3–mediated neovascularization, our results suggested that the new ovarian lymphatic vessels specifically modulate follicle development and hormone production, demonstrating a critical and novel role for ovarian lymphangiogenesis in reproduction. 相似文献
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Edwards Richard Greenwood Hannah E. McRobbie Graeme Khan Imtiaz Witney Timothy H. 《Molecular imaging and biology》2021,23(6):854-864
Molecular Imaging and Biology - (S)-4-(3-18F-Fluoropropyl)-?-Glutamic Acid ([18F]FSPG) is a radiolabeled non-natural amino acid that is used for positron emission tomography (PET) imaging of... 相似文献
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