239 research outputs found

    The percutaneous assessment of regional and acute coronary hot unstable plaques by thermographic evaluation (PARACHUTE) study: A prospective reproducibility and prognostic clinical study using thermography to predict future ischemic cardiac events

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    Intravascular thermography is currently being considered as a valuable tool in assessing macrophage-rich plaques. Since it is unknown what the prognostic value is of non-obstructive atherosclerotic plaques showing temperature heterogeneity, we designed the PARACHUTE study, a prospective, reproducibility, and prognostic clinical study using thermography in patients presenting with an unstable coronary syndrome. The primary endpoint of the study is the predictive value of temperature heterogeneity towards the occurrence of ischemic coronary events and hospitalization for ischemia and/or angina. The secondary endpoints are the predictive value of high-risk plaques associated with the development of future cardiac events, assessmen

    Low rate of rhesus immunization from rh- incompatible blood transfusions during liver and heart transplant surgery

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    Transfusion of one unit or more of Rh-positive red blood cells normally causes circulating anti-D antibody to appear 2-6 months later in 80-95% of Rh persons. We asked whether transplant immunosuppression with cyclosporine and corticosteroids affects Rh immuniza¬tion. Nineteen Rh" liver, heart, and heart-lung transplant recipients received 3—153 (median: 10) units of Rh+ RBCs at surgery and were tested for anti-D >2 months later. Three patients developed anti-D at 11—15 days; one may have had an unusually rapid primary immune response and two were secondary to previous exposure by pregnancy. None of the other 16 patients had anti-D when tested 2.5-51 months later (13 patients, >11.5 months). This low rate of Rhesus immunization in association with cyclosporine immunosuppression allows greater flexibility in meeting the transfusion needs of Rh- liver and heart transplant patients. Caution is still advised in young females and in patients who may have been previously exposed to Rh+ RBCs by transfusion or by pregnancy prior to the availability of perinatal Rh immune globulin twenty years ago. Other humoral immune responses to some vaccines or infectious agents may also be impaired in transplant patients© 1989 by The Williams and Wilkins Co

    Diagnostic and treatment characteristics of polycystic ovary syndrome: descriptive measurements of patient perception and awareness from 657 confidential self-reports

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    BACKGROUND: This investigation was undertaken to describe patient perception and awareness of the polycystic ovary syndrome (PCOS), the most common cause of anovulation/oligoovulation among women of reproductive age. METHODS: Fifteen parameters were evaluated by a computer-based research instrument accessed by a large, unscreened population. Incomplete questionnaires were not entered, and responses were electronically tabulated to block duplicate submissions. RESULTS: From 657 participants, the majority (63%) were between 26–34 years old; mean BMI was 30.4 kg/m(2). 343 of 657 had at least one pregnancy and 61% of the study group had taken fertility medicine (any type) at least once. Physicians were the most common provider of PCOS information for all study participants, irrespective of age. Patient emotions associated with the diagnosis of PCOS included "frustration" (67%), "anxiety" (16%), "sadness" (10%), and "indifference" (2%). Self-reported patient aptitude regarding PCOS was scored as high or "very aware" in >60% of women. Respondents were also asked: "If your PCOS could be safely and effectively helped by something else besides fertility drugs or birth control pills, would that interest you?" Interest in alternative PCOS treatments was expressed by 99% of the sample (n = 648). CONCLUSIONS: In our study population, most women associated negative emotions with PCOS although the self-reported knowledge level for the disorder was high. While these women regarded their obstetrician-gynecologist as integral to their PCOS education, traditional PCOS therapies based on oral contraceptives or ovulation induction agents were regarded as unsatisfactory by most women

    Saturn's Seasonal Variability from Four Decades of Ground-Based Mid-Infrared Observations

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    A multi-decade record of ground-based mid-infrared (7-25 μ\mum) images of Saturn is used to explore seasonal and non-seasonal variability in thermal emission over more than a Saturnian year (1984-2022). Thermal emission measured by 3-m and 8-m-class observatories compares favourably with synthetic images based on both Cassini-derived temperature records and the predictions of radiative climate models. 8-m class facilities are capable of resolving thermal contrasts on the scale of Saturn's belts, zones, polar hexagon, and polar cyclones, superimposed onto large-scale seasonal asymmetries. Seasonal changes in brightness temperatures of 30\sim30 K in the stratosphere and 10\sim10 K in the upper troposphere are observed, as the northern and southern polar stratospheric vortices (NPSV and SPSV) form in spring and dissipate in autumn. The timings of the first appearance of the warm polar vortices is successfully reproduced by radiative climate models, confirming them to be radiative phenomena, albeit entrained within sharp boundaries influenced by dynamics. Axisymmetric thermal bands (4-5 per hemisphere) display temperature gradients that are strongly correlated with Saturn's zonal winds, indicating winds that decay in strength with altitude, and implying meridional circulation cells forming the system of cool zones and warm belts. Saturn's thermal structure is largely repeatable from year to year (via comparison of infrared images in 1989 and 2018), with the exception of low-latitudes. Here we find evidence of inter-annual variations because the equatorial banding at 7.9 μ\mum is inconsistent with a 15\sim15-year period for Saturn's equatorial stratospheric oscillation, i.e., it is not strictly semi-annual. Finally, observations between 2017-2022 extend the legacy of the Cassini mission, revealing the continued warming of the NPSV during northern summer. [Abr.]Comment: 25 pages, 15 figures, accepted for publication in Icaru

    Viral population estimation using pyrosequencing

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    The diversity of virus populations within single infected hosts presents a major difficulty for the natural immune response as well as for vaccine design and antiviral drug therapy. Recently developed pyrophosphate based sequencing technologies (pyrosequencing) can be used for quantifying this diversity by ultra-deep sequencing of virus samples. We present computational methods for the analysis of such sequence data and apply these techniques to pyrosequencing data obtained from HIV populations within patients harboring drug resistant virus strains. Our main result is the estimation of the population structure of the sample from the pyrosequencing reads. This inference is based on a statistical approach to error correction, followed by a combinatorial algorithm for constructing a minimal set of haplotypes that explain the data. Using this set of explaining haplotypes, we apply a statistical model to infer the frequencies of the haplotypes in the population via an EM algorithm. We demonstrate that pyrosequencing reads allow for effective population reconstruction by extensive simulations and by comparison to 165 sequences obtained directly from clonal sequencing of four independent, diverse HIV populations. Thus, pyrosequencing can be used for cost-effective estimation of the structure of virus populations, promising new insights into viral evolutionary dynamics and disease control strategies.Comment: 23 pages, 13 figure

    Aptamer-based multiplexed proteomic technology for biomarker discovery

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    Interrogation of the human proteome in a highly multiplexed and efficient manner remains a coveted and challenging goal in biology. We present a new aptamer-based proteomic technology for biomarker discovery capable of simultaneously measuring thousands of proteins from small sample volumes (15 [mu]L of serum or plasma). Our current assay allows us to measure ~800 proteins with very low limits of detection (1 pM average), 7 logs of overall dynamic range, and 5% average coefficient of variation. This technology is enabled by a new generation of aptamers that contain chemically modified nucleotides, which greatly expand the physicochemical diversity of the large randomized nucleic acid libraries from which the aptamers are selected. Proteins in complex matrices such as plasma are measured with a process that transforms a signature of protein concentrations into a corresponding DNA aptamer concentration signature, which is then quantified with a DNA microarray. In essence, our assay takes advantage of the dual nature of aptamers as both folded binding entities with defined shapes and unique sequences recognizable by specific hybridization probes. To demonstrate the utility of our proteomics biomarker discovery technology, we applied it to a clinical study of chronic kidney disease (CKD). We identified two well known CKD biomarkers as well as an additional 58 potential CKD biomarkers. These results demonstrate the potential utility of our technology to discover unique protein signatures characteristic of various disease states. More generally, we describe a versatile and powerful tool that allows large-scale comparison of proteome profiles among discrete populations. This unbiased and highly multiplexed search engine will enable the discovery of novel biomarkers in a manner that is unencumbered by our incomplete knowledge of biology, thereby helping to advance the next generation of evidence-based medicine

    Gender-Specific Modulation of the Response to Arterial Injury by Soluble Guanylate Cyclase α1

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    Objective: Soluble guanylate cyclase (sGC), a heterodimer composed of α and β subunits, synthesizes cGMP in response to nitric oxide (NO). NO modulates vascular tone and structure but the relative contributions of cGMP-dependent versus cGMP-independent mechanisms remain uncertain. We studied the response to vascular injury in male (M) and female (F) mice with targeted deletion of exon 6 of the sGCα1 subunit (sGCα1-/-), resulting in a non-functional heterodimer. Methods: We measured aortic cGMP levels and mRNA transcripts encoding sGC α1, α2, and β1 subunits in wild type (WT) and sGCa1-/- mice. To study the response to vascular injury, BrdU-incorporation and neointima formation (maximum intima to media (I/M) ratio) were determined 5 and 28 days after carotid artery ligation, respectively. Results: Aortic cGMP levels were 4-fold higher in F than in M mice in both genotypes, and, within each gender, 4-fold higher in WT than in sGCa1-/-. In contrast, sGCα1, sGCα2, and sGCβ1 mRNA expression did not differ between groups. 3H-thymidine incorporation in cultured sGCa1-/- smooth muscle cells (SMC) was 27%±12% lower than in WT SMC and BrdU-incorporation in carotid arteries 5 days after ligation was significantly less in sGCa1-/- M than in WT M. Neointima area and I/M 28 days after ligation were 65% and 62% lower in sGCa1-/- M than in WT M mice (p<0,05 for both) but were not different in F mice. Conclusion: Functional deletion of sGCa1 resulted in reduced cGMP levels in male sGCa1-/- mice and a gender-specific effect on the adaptive response to vascular injury

    Decreasing the minimum length criterion for an episode of hypomania: evaluation using self-reported data from patients with bipolar disorder

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    Brief hypomania lasting less than 4 days may impair functioning and help to detect bipolarity. This study analyzed brief hypomania that occurred in patients with bipolar disorder who were diagnosed according to the DSM-IV criteria. Daily self-reported mood ratings were obtained from 393 patients (247 bipolar I and 146 bipolar II) for 6 months (75,284 days of data, mean 191.6 days). Episodes of hypomania were calculated using a 4, 3, 2, and single day length criterion. Brief hypomania occurred frequently. With a decrease in the minimum criterion from 4 days to 2 days, there were almost twice as many patients with an episode of hypomania (102 vs. 190), and more than twice as many episodes (305 vs. 863). Single days of hypomania were experienced by 271 (69%) of the sample. With a 2-day episode length, 33% of all hypomania remained outside of an episode. There was no significant difference in the percent of hypomanic days outside of an episode between patients with bipolar I and II disorders. There were no significant differences in the demographic characteristics of patients who met the 4-day minimum as compared with those who only experienced episodes of hypomania using a shortened length criterion. Decreasing the minimum length criterion for an episode of hypomania will cause a large increase in the number of patients who experience an episode and in the aggregate number of episodes, but will not distinguish subgroups within a sample who meet the DSM-IV criteria for bipolar disorder. Frequency may be an important dimensional aspect of brief hypomania. Clinicians should regularly probe for brief hypomania

    Controlling Population Evolution in the Laboratory to Evaluate Methods of Historical Inference

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    Natural populations of known detailed past demographic history are extremely valuable to evaluate methods of historical inference, yet are extremely rare. As an alternative approach, we have generated multiple replicate microsatellite data sets from laboratory-cultured populations of a gonochoric free-living nematode, Caenorhabditis remanei, that were constrained to pre-defined demographic histories featuring different levels of migration among populations or bottleneck events of different magnitudes. These data sets were then used to evaluate the performances of two recently developed population genetics methods, BayesAss+, that estimates recent migration rates among populations, and Bottleneck, that detects the occurrence of recent bottlenecks. Migration rates inferred by BayesAss+ were generally over-estimates, although these were often included within the confidence interval. Analyses of data sets simulated in-silico, using a model mimicking the laboratory experiments, produced less biased estimates of the migration rates, and showed increased efficiency of the program when the number of loci and sampled genotypes per population was higher. In the replicates for which the pre-bottleneck laboratory-cultured populations did not significantly depart from a mutation/drift equilibrium, an important assumption of the program Bottleneck, only a portion of the bottleneck events were detected. This result was confirmed by in-silico simulations mirroring the laboratory bottleneck experiments. More generally, our study demonstrates the feasibility, and highlights some of the limits, of the approach that consists in generating molecular genetic data sets by controlling the evolution of laboratory-reared nematode populations, for the purpose of validating methods inferring population history

    Evidence for Time-of-Day Dependent Effect of Neurotoxic Dorsomedial Hypothalamic Lesions on Food Anticipatory Circadian Rhythms in Rats

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    The dorsomedial hypothalamus (DMH) is a site of circadian clock gene and immediate early gene expression inducible by daytime restricted feeding schedules that entrain food anticipatory circadian rhythms in rats and mice. The role of the DMH in the expression of anticipatory rhythms has been evaluated using different lesion methods. Partial lesions created with the neurotoxin ibotenic acid (IBO) have been reported to attenuate food anticipatory rhythms, while complete lesions made with radiofrequency current leave anticipatory rhythms largely intact. We tested a hypothesis that the DMH and fibers of passage spared by IBO lesions play a time-of-day dependent role in the expression of food anticipatory rhythms. Rats received intra-DMH microinjections of IBO and activity and body temperature (Tb) rhythms were recorded by telemetry during ad-lib food access, total food deprivation and scheduled feeding, with food provided for 4-h/day for 20 days in the middle of the light period and then for 20 days late in the dark period. During ad-lib food access, rats with DMH lesions exhibited a lower amplitude and mean level of light-dark entrained activity and Tb rhythms. During the daytime feeding schedule, all rats exhibited food anticipatory activity and Tb rhythms that persisted during 2 days without food in constant dark. In some rats with partial or total DMH ablation, the magnitude of the anticipatory rhythm was weak relative to most intact rats. When mealtime was shifted to the late night, the magnitude of the food anticipatory activity rhythms in these cases was restored to levels characteristic of intact rats. These results confirm that rats can anticipate scheduled daytime or nighttime meals without the DMH. Improved anticipation at night suggests a modulatory role for the DMH in the expression of food anticipatory activity rhythms during the daily light period, when nocturnal rodents normally sleep
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