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Parallel Fashion (parallel + fashion)
Selected AbstractsRespiratory muscle performance with stretch-shortening cycle manoeuvres: maximal inspiratory pressure,flow curvesACTA PHYSIOLOGICA, Issue 3 2005G. E. Tzelepis Abstract Aim:, To test the hypothesis that the maximal inspiratory muscle (IM) performance, as assessed by the maximal IM pressure,flow relationship, is enhanced with the stretch-shortening cycle (SSC). Methods:, Maximal inspiratory flow,pressure curves were measured in 12 healthy volunteers (35 ± 6 years) during maximal single efforts through a range of graded resistors (4-, 6-, and 8-mm diameter orifices), against an occluded airway, and with a minimal load (wide-open resistor). Maximal inspiratory efforts were initiated at a volume near residual lung volume (RV). The subjects exhaled to RV using slow (S) or fast (F) manoeuvres. With the S manoeuvre, they exhaled slowly to RV and held the breath at RV for about 4 s prior to maximal inspiration. With the F manoeuvre, they exhaled rapidly to RV and immediately inhaled maximally without a post-expiratory hold; a strategy designed to enhance inspiratory pressure via the SSC. Results:, The maximal inspiratory pressure,flow relationship was linear with the S and F manoeuvres (r2 = 0.88 for S and r2 = 0.88 for F manoeuvre, P < 0.0005 in all subjects). With the F manoeuvre, the pressure,flow relationship shifted to the right in a parallel fashion and the calculated maximal power increased by approximately 10% (P < 0.05) over that calculated with the S manoeuvre. Conclusion:, The maximal inspiratory pressure,flow capacity can be enhanced with SSC manoeuvres in a manner analogous to increases in the force,velocity relationship with SSC reported for skeletal muscles. [source] Solar-simulating irradiation of the skin of human subjects in vivo produces Langerhans cell responses distinct from irradiation ex vivo and in vitroEXPERIMENTAL DERMATOLOGY, Issue 4 2000J. K. Laihia Abstract: It has been postulated that Langerhans cells (LC) provide tolerogenic signals in the local impairment of cutaneous immune functions and antigen-specific tolerance induced by UV radiation. Studies in vitro and ex vivo have indicated that UV radiation may down-regulate the expression of costimulatory molecules on LC, leading to reduced antigen-presenting function. In contrast, we recently observed an up-regulatory stage in the number of human epidermal LC with induced expression of B7 costimulatory molecules 12,24 h after solar-simulating UV radiation (SSR) in vivo. To examine the apparent discrepancy between the observed human LC responses in vitro, ex vivo and in vivo, we compared the three protocols in a parallel fashion. The intact skin as well as skin explants and epidermal cell suspensions from the same individuals were irradiated with a single erythematogenic dose of SSR. The expression of cell surface markers in the epidermal cells was analysed with flow cytometry 24 h later. The number of CD1a+/HLA-DR+ LC increased post-SSR in vivo by a factor of 2.8±0.4, whereas in irradiated skin explants ex vivo or in cell suspensions in vitro, reduced numbers were seen. HLA-DR expression intensities were found to have increased on DR+ and CD1a+/DR+ cells in vivo. Similarly, SSR induced B7-2 (CD86) expression in CD1a+ cells significantly in vivo (P=0.031) but reduced the expression ex vivo or in vitro. We conclude that the early up-regulatory stage of human LC number and membrane markers, recorded at 24 h after a single exposure to SSR, is exclusively an in vivo phenomenon. [source] A fast implementation of the FETI-DP method: FETI-DP-RBS-LNA and applications on large scale problems with localized non-linearitiesINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 6 2005Jun Sun Abstract As parallel and distributed computing gradually becomes the computing standard for large scale problems, the domain decomposition method (DD) has received growing attention since it provides a natural basis for splitting a large problem into many small problems, which can be submitted to individual computing nodes and processed in a parallel fashion. This approach not only provides a method to solve large scale problems that are not solvable on a single computer by using direct sparse solvers but also gives a flexible solution to deal with large scale problems with localized non-linearities. When some parts of the structure are modified, only the corresponding subdomains and the interface equation that connects all the subdomains need to be recomputed. In this paper, the dual,primal finite element tearing and interconnecting method (FETI-DP) is carefully investigated, and a reduced back-substitution (RBS) algorithm is proposed to accelerate the time-consuming preconditioned conjugate gradient (PCG) iterations involved in the interface problems. Linear,non-linear analysis (LNA) is also adopted for large scale problems with localized non-linearities based on subdomain linear,non-linear identification criteria. This combined approach is named as the FETI-DP-RBS-LNA algorithm and demonstrated on the mechanical analyses of a welding problem. Serial CPU costs of this algorithm are measured at each solution stage and compared with that from the IBM Watson direct sparse solver and the FETI-DP method. The results demonstrate the effectiveness of the proposed computational approach for simulating welding problems, which is representative of a large class of three-dimensional large scale problems with localized non-linearities. Copyright © 2005 John Wiley & Sons, Ltd. [source] Collagen architecture and failure processes in bovine patellar cartilageJOURNAL OF ANATOMY, Issue 4 2001JACK L. LEWIS Cartilage fails by fibrillation and wearing away. This study was designed to identify the microscopic failure processes in the collagen network of bovine cartilage using scanning electron microscopy. Cartilage samples from fibrillated cartilage from the bovine patella were removed from the bone, fixed, digested to remove proteoglycans, freeze-fractured, and processed for SEM. The architecture of the collagen network in the normal cartilage was first defined, and then the failure processes were identified by examining sites of fibrillation and at crack tips. The bovine patellar cartilage was organised with a superficial layer composed of 3,5 lamina, attached to a sub-superficial tissue by angled bridging fibrils. Collagen in the sub-superficial tissue was organised in lamina oriented in the radial direction up to the transition zone. Failure of the system occurred by cracks forming in superficial layer and lamina, creating flaps of lamina that rolled up into the larger ,fronds'. Larger cracks not following the laminar planes occurred in the transition, mid, and deep zones. Failure at the crack tips in the sub-superficial tissue appeared to be by peeling of collagen fibrils, as opposed to breaking of collagen fibrils, suggesting a ,glue' bonding the collagen fibrils in a parallel fashion. Cracks propagated by breaking these bonds. This bond could be a site of disease action, since weakening of the bond would accelerate crack propagation. [source] Comparative study of four candidate strategies to detect cervical cancer in different health care settingsJOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 4 2007Meherbano M. Kamal Abstract Aim:, Considering the differing but potentially supplementary properties of visual inspection of the cervix with acetic acid (VIA) and the cytological examination (CYTO) of cervical smears for the screening of cervical cancers, we examined the performance of these two tests and their combinations for the screening of cervical cancer in different health care settings. Methods:, In this cross-sectional diagnostic test performance evaluation study of 4235 female subjects in the reproductive age group, we assessed the screening performance of four strategies: VIA alone, CYTO alone, VIA and CYTO combined in a parallel fashion, and VIA and CYTO combined in tandem. Subjects were recruited from three settings: Hospital, Urban Community and Rural Community. Colposcopy was used as the reference standard. Screening performance was assessed using sensitivity, specificity, post-test probabilities and likelihood ratios (LR), diagnostic odds, area under receiver operating characteristic curve and LR ,2. Results:, Both VIA and CYTO when used alone had a low sensitivity but high specificity, especially in the Rural Community setting. A combination of the results of VIA and CYTO improved the diagnostic accuracy but the strategy using a parallel combination of VIA and CYTO was the most accurate. In general, all screening strategies using VIA and CYTO showed a modest screening performance. Conclusions:, In the settings of varying levels of health care and low resources, caution is needed for a generalized use of VIA for cervical cancer screening. Further evaluation of the cost-effective ways of combining VIA and CYTO is needed in these circumstances. [source] Transdifferentiation of adipose-derived stem cells into hepatocytes: a new approachLIVER INTERNATIONAL, Issue 6 2010James Lue Abstract Background: Several studies have demonstrated techniques in differentiating human adipose-derived stem cells (hADSCs) into hepatocytes. Unfortunately, transdifferentiation is inefficient, and the function of these induced hepatocyte-like cells (which we termed ,iHeps') is low compared with that of real hepatocytes. Aims: We aimed to identify transcriptional deficiencies in iHeps that are critical to hepatocyte development, which may provide insights into improving the efficiency of transdifferentiation. Methods: hADSCs were differentiated into iHeps, and iHeps were assayed for hepatocyte-like activity. iHeps were then screened for expression of several growth factors, receptors and transcription factors (TFs) critical to liver development using reverse transcription-polymerase chain reaction (RT-PCR). Deficient TFs were transduced into hADSCs and hepatocyte function was reassessed after hepatic differentiation. Results: Differentiation of hADSCs into iHeps resulted in the upregulation of hepatic proteins. However, the levels of expression of hepatocyte-specific proteins in these iHeps were well below those of Huh 7.5 hepatoma cells, used in comparison. Five developmental TFs were notably absent on the RT-PCR screen. Lentiviral transduction of these TFs into hADSCs followed by culture in hepatocyte induction medium resulted in increased albumin expression compared with untransduced hADSCs treated in a parallel fashion. Conclusions: These five missing TFs are known to regulate hepatocyte differentiation and some are required to establish the competence of the foregut endoderm. Presumably due to their mesenchymal lineage, hADSCs do not express these endodermal TFs and are not fully competent to respond to critical developmental signals. Supplementation of these TFs may induce competency and enhance the differentiation of hADSCs into hepatocytes. [source] The transcriptomics of life-history trade-offs in whitefish species pairs (Coregonus sp.)MOLECULAR ECOLOGY, Issue 7 2008J. ST-CYR Abstract Despite the progress achieved in elucidating the ecological mechanisms of adaptive radiation, there has been little focus on documenting the extent of adaptive differentiation in physiological functions during this process. Moreover, a thorough understanding of the genomic basis underlying phenotypic adaptive divergence is still in its infancy. One important evolutionary process for which causal genetic mechanisms are largely unknown pertains to life-history trade-offs. We analysed patterns of gene transcription in liver tissue of sympatric dwarf and normal whitefish from two natural lakes, as well as from populations reared in controlled environments, using a 16 006-gene cDNA microarray in order to: (i) document the extent of physiological adaptive divergence between sympatric dwarf and normal species pairs, and (ii) explore the molecular mechanisms of differential life history trade-offs between growth and survival potentially involved in their adaptive divergence. In the two natural lakes, 6.45% of significantly transcribed genes showed regulation either in parallel fashion (2.39%) or in different directions (4.06%). Among genes showing parallelism in regulation patterns, we observed a higher proportion of over-expressed genes in dwarf relative to normal whitefish (70.6%). Patterns observed in controlled conditions were also generally congruent with those observed in natural populations. Dwarf whitefish consistently showed significant over-expression of genes potentially associated with survival through enhanced activity (energy metabolism, iron homeostasis, lipid metabolism, detoxification), whereas more genes associated with growth (protein synthesis, cell cycle, cell growth) were generally down-regulated in dwarf relative to normal whitefish. Overall, parallelism in patterns of gene transcription, as well as patterns of interindividual variation across controlled and natural environments, provide strong indirect evidence for the role of selection in the evolution of differential regulation of genes involving a vast array of potentially adaptive physiological processes between dwarf and normal whitefish. Our results also provide a first mechanistic, genomic basis for the observed trade-off in life-history traits distinguishing dwarf and normal whitefish species pairs, wherein enhanced survival via more active swimming, necessary for increased foraging and predator avoidance, engages energetic costs that translate into slower growth rate and reduced fecundity in dwarf relative to normal whitefish. [source] A growth hormone-secreting adenoma with incomplete nerve bundle formationNEUROPATHOLOGY, Issue 3 2008Hidetoshi Ikeda We present a unique case of an adenoma secreting growth hormone (GH), showing incomplete nerve bundle formation without ganglion cells. A 47-year-old man presenting with acromegaly was revealed to have high serum GH and IGF-1 levels. The concentrations of the other adenohypophysial hormones were within the normal range. Histology revealed an unusual pituitary adenoma containing many nerve bundle-like structures. Adenoma cells with ovoid or round hyperchromatic nuclei and eosinophilic cytoplasms lacked the typical features of ganglion cells. The nerve bundles consisted of slender elongated cells. These fibers were arranged into groups in a roughly parallel fashion. By immunohistochemistry, many adenoma cells were positive for GH, prolactin, thyrotropin beta, synaptophysin and chromogranin. Fibrous bodies revealed by keratin immunostaining were found only in adenoma cells. Scattered star-shaped adenoma cells showed the same immunoreactivity as folliculo-satellite cells. Adenoma cells, but not the bundle-like structures, were also positive for Pit-1. Immunostaining for neurofilament protein, GFAP, vimentin, and S-100 protein revealed variable amounts of fibrils within the bundle-like structures. Scattered immunoreactivity for myelin basic protein and synaptophysin was also found in the bundle area. Our case is the first GH-secreting pituitary adenoma showing incomplete nerve bundle differentiation and lacking mature ganglion cells. [source] Current state and prospects of macromolecular crystallographyACTA CRYSTALLOGRAPHICA SECTION D, Issue 1 2006Zbigniew Dauter The current situation and possible future development of macromolecular crystallography are reviewed. The rapid progress and maturation of this field in recent years have to a large extent been made possible by the inspiration and generous support of several active structural genomics initiatives. Two tendencies can be currently observed: one which treats protein crystallography as a highly automatic tool for investigating various biological problems without the need to engage in the intricacies of the technique and a second approach where this method is applied to crystals of difficult, large and complex biological systems, requiring a deeper knowledge of various aspects of crystallography. In the near future it is expected that these two trends will coexist, developing in a parallel fashion. [source] Pharmacokinetics and dose proportionality of BMS-204352 after intraarterial administration to ratsBIOPHARMACEUTICS AND DRUG DISPOSITION, Issue 6 2002Rajesh Krishna Abstract BMS-204352 is a novel maxi-K channel opener that is being developed for the treatment for stroke. The current study was designed to evaluate the dose proportionality and pharmacokinetics of BMS-204352 in rats. In an open, parallel fashion, sixteen rats per gender received a single intraarterial dose of BMS-204352 as a 3-min infusion into the carotid artery at 0.4, 2.0, 5.0 and 10.0 mg/kg dose levels. Serial blood samples were collected for up to 24 h post-dose and plasma samples were analyzed for the concentrations of intact BMS-204352 using a validated liquid chromatographic mass spectrometric (LC/MS) method. Pharmacokinetic analysis was performed using a non-compartmental method. Results revealed a gender difference in the pharmacokinetics of BMS-204352 in rats at all doses excluding the first (i.e., 0.4 mg/kg) dose panel. BMS-204352 peak plasma concentration (Cmax) and area under the plasma concentration,time curve (AUC) values increased in a proportion greater than the increment in dose. Specifically, as dose increased in the ratio 1:5:12.5:25, Cmax increased in the ratio 1:7:18:31 in male rats and 1:7:22:51 in female rats. The respective AUC ratios were 1:6:20:42 in male rats and 1:12:29:77 in female rats. Mean total body clearance (CLT) values for BMS-204352 ranged from 879,3242 ml/h/kg over the four dose levels and generally decreased with increase in dose. Similarly, steady state volume of distribution (VSS) values ranged from 3621,8933 ml/kg over the four dose levels and generally decreased with increase in dose. However, mean residence time (MRT) and elimination half-life (T1/2) values for BMS-204352 were independent of dose and ranged from 2.42,4.54 to 2.08,4.70 h, respectively. In conclusion, BMS-204352 appears to exhibit dose-dependent pharmacokinetics in rats. In addition, there appeared to be some evidence of gender related differences in the pharmacokinetics of BMS-204352. Copyright © 2002 John Wiley & Sons, Ltd. [source] | |||||||||||||