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排序方式: 共有660条查询结果,搜索用时 78 毫秒
31.
32.
Jing Ping Sun Edward Chinchoy Erwan Donal Zoran B Popovi? George Perlic Craig R Asher Neil L Greenberg Richard A Grimm Bruce L Wilkoff James D Thomas 《Journal of the American Society of Echocardiography》2004,17(8):845-850
Cardiac resynchronization therapy improves hemodynamics in selected patients with heart failure. Mechanic asynchrony parameters that may guide patient selection or therapy optimization are still being investigated. A biventricular (BiV) pacemaker was implanted in 34 patients with dilated ischemic, idiopathic, or valvular cardiomyopathy, and a QRS duration of > or =130 milliseconds. Two-dimensional standard and Doppler tissue echocardiography was performed during right ventricular (RV), left ventricular (LV), BiV, and no pacing in a random and blinded manner. LV and BiV pacing increased stroke volume (P <.02 for both) and ejection fraction (P <.001 for both). Regional contractility assessed by displacement, strain rate, and peak systolic strain was improved in some segments (P <.05) during LV and BiV pacing. A homogenization of segmental contractions was observed during LV and BiV pacing as evaluated by net systolic displacement and segmental myocardial performance index. LV and BiV pacing provides benefits that can be quantified by echocardiography. 相似文献
33.
Caillard S Pencreach E Braun L Marcellin L Jaegle ML Wolf P Parissiadis A Hannedouche T Gaub MP Moulin B 《Transplantation》2005,79(1):79-84
BACKGROUND: Posttransplant lymphoproliferative disorders (PTLD) occur in 0.5% to 2.5% of cases in renal-transplant recipients. Epstein-Barr virus (EBV) is usually detected in the tumor cells, suggesting a role for this virus as an agent of B-cell proliferation. It is unusual for patients receiving allografts from the same donor to develop PTLD simultaneously. METHODS: we describe two patients who received renal allografts from the same donor and developed PTLD simultaneously. The presence of EBV in both tumors was confirmed. In this report, the origin of tumor cells was determined by immunohistochemical human leukocyte antigen (HLA) typing and microsatellite analysis. Clonality was studied by immunoglobulin gene rearrangement analysis. RESULTS: Our results suggest that the tumor originated from donor cells in both patients but, because immunoglobulin gene rearrangements were different, this could mean that lymphoid cells proliferate independently in each recipient. CONCLUSIONS: We propose the following pathogenesis: immortalization of passenger B lymphocytes by EBV, proliferation of these cells, and development of PTLD by means of immunosuppression, antigenic stimulation, and HLA mismatch. 相似文献
34.
Erwan Sallard Frank Schult Carolin Baehren Eleni Buedding Olivier Mboma Parviz Ahmad-Nejad Beniam Ghebremedhin Anja Ehrhardt Stefan Wirth Malik Aydin 《Viruses》2022,14(3)
Respiratory viruses play an important role in asthma exacerbation, and early exposure can be involved in recurrent bronchitis and the development of asthma. The exact mechanism is not fully clarified, and pathogen-to-host interaction studies are warranted to identify biomarkers of exacerbation in the early phase. Only a limited number of international exacerbation cohorts were studied. Here, we have established a local pediatric exacerbation study in Germany consisting of children with asthma or chronic, recurrent bronchitis and analyzed the viriome within the nasopharyngeal swab specimens derived from the entire cohort (n = 141). Interestingly, 41% of exacerbated children had a positive test result for human rhinovirus (HRV)/human enterovirus (HEV), and 14% were positive for respiratory syncytial virus (RSV). HRV was particularly prevalent in asthmatics (56%), wheezers (50%), and atopic (66%) patients. Lymphocytes were decreased in asthmatics and in HRV-infected subjects, and patients allergic to house dust mites were more susceptible to HRV infection. Our study thus confirms HRV infection as a strong ‘biomarker’ of exacerbated asthma. Further longitudinal studies will show the clinical progress of those children with a history of an RSV or HRV infection. Vaccination strategies and novel treatment guidelines against HRV are urgently needed to protect those high-risk children from a serious course of disease. 相似文献
35.
Erwan Joël David Pierre Lebranchu Matthieu Perreira Da Silva Patrick Le Callet 《Journal of vision》2022,22(4)
Central and peripheral vision during visual tasks have been extensively studied on two-dimensional screens, highlighting their perceptual and functional disparities. This study has two objectives: replicating on-screen gaze-contingent experiments removing central or peripheral field of view in virtual reality, and identifying visuo-motor biases specific to the exploration of 360 scenes with a wide field of view. Our results are useful for vision modelling, with applications in gaze position prediction (e.g., content compression and streaming). We ask how previous on-screen findings translate to conditions where observers can use their head to explore stimuli. We implemented a gaze-contingent paradigm to simulate loss of vision in virtual reality, participants could freely view omnidirectional natural scenes. This protocol allows the simulation of vision loss with an extended field of view (80°) and studying the head''s contributions to visual attention. The time-course of visuo-motor variables in our pure free-viewing task reveals long fixations and short saccades during first seconds of exploration, contrary to literature in visual tasks guided by instructions. We show that the effect of vision loss is reflected primarily on eye movements, in a manner consistent with two-dimensional screens literature. We hypothesize that head movements mainly serve to explore the scenes during free-viewing, the presence of masks did not significantly impact head scanning behaviours. We present new fixational and saccadic visuo-motor tendencies in a 360° context that we hope will help in the creation of gaze prediction models dedicated to virtual reality. 相似文献
36.
37.
Raquel Abad Clara I. Agudelo M. Cristina Brandileone Grettel Chanto Jean Marc Gabastou Juan Carlos Hormazabal M. Cecilia O Gorla Aurora Maldonado Jaime Moreno Erwan Muros-Le Rouzic Robert Lersch Mabel Regueira Celia Salcedo Cecilia Sorhouet Julio A. Vzquez 《The Journal of infection》2009,59(2):104-114
38.
Park Y Sugimoto M Watrin A Chiquet M Hunziker EB 《Osteoarthritis and cartilage / OARS, Osteoarthritis Research Society》2005,13(6):527-536
OBJECTIVE: According to recent reports, the synovial membrane may contain mesenchymal stem cells with the potential to differentiate into chondrocytes under appropriate conditions. In order to assess the usefulness of synovium-derived progenitor cells for the purposes of cartilage tissue engineering, we explored their requirements for the expression of chondrocyte-specific genes after expansion in vitro. DESIGN: Mesenchymal progenitor cells were isolated from the synovial membranes of bovine shoulder joints and expanded in two-dimensions on plastic surfaces. They were then seeded either as micromass cultures or as single cells within alginate gels, which were cultured in serum-free medium. Under these three-dimensional conditions, chondrogenesis is known to be supported and maintained. Cell cultures were exposed either to bone morphogenetic protein-2 (BMP-2) or to isoforms of transforming growth factor-beta (TGF-beta). The levels of mRNA for Sox9, collagen types I and II and aggrecan were determined by RT-PCR. RESULTS: When transferred to alginate gel cultures, the fibroblast-like synovial cells assumed a rounded form. BMP-2, but not isoforms of TGF-beta, stimulated, in a dose-dependent manner, the production of messenger RNAs (mRNAs) for Sox9, type II collagen and aggrecan. Under optimal conditions, the expression levels of cartilage-specific genes were comparable to those within cultured articular cartilage chondrocytes. However, in contrast to cultured articular cartilage chondrocytes, synovial cells exposed to BMP-2 continued to express the mRNA for alpha1(I) collagen. CONCLUSIONS: This study demonstrates that bovine synovium-derived mesenchymal progenitor cells can be induced to express chondrocyte-specific genes. However, the differentiation process is not complete under the chosen conditions. The stimulation conditions required for full transformation must now be delineated. 相似文献
39.
Nouwen J Hans S De Mones E Brasnu D Crevier-Buchman L Laccourreye O 《Acta oto-laryngologica》2004,124(6):732-738
OBJECTIVE: The current series was designed to compare the results achieved with the Montgomery and Gore-Tex implants in thyroplasty type I without arytenoid adduction in patients with unilateral laryngeal nerve paralysis. MATERIAL AND METHODS: An inception cohort of 57 French language speakers with unilateral laryngeal nerve paralysis were managed with thyroplasty type I using Gore-Tex (Group GT; n = 24) or Montgomery (Group M; n = 33) implants. The two groups had similar patient characteristics. Morbidity, phonatory results according to self assessment by the patient and selected speech and voice parameters (fundamental frequency, jitter, shimmer, noise:harmonic ratio, phonation time, phrase grouping and speech rate) were analyzed 1 month postoperatively in both groups. RESULTS: Dyspnea, as noted in three patients, was the only immediate complication. Late complications included persistent inflammation of the vocal cord after insertion of a Gore-Tex implant, endolaryngeal extrusion of the Gore-Tex implant and dislodgment of the Montgomery implant in one patient each. Postoperatively, all patients reported improvements in speech and voice. Secondary degradation of speech and voice was noted in one patient in each group. Comparison of selected speech and voice parameters at 1 month postoperatively showed (i) a statistically significant (p < 0.01) decrease in the jitter, shimmer and noise:harmonic ratio values and (ii) a statistically significant (p < 0.01) increase in the speech rate values in Group M compared to Group GT patients. Also, a trend (0.05
相似文献
40.
Hsu A Togasaki DM Bezard E Sokoloff P Langston JW Di Monte DA Quik M 《The Journal of pharmacology and experimental therapeutics》2004,311(2):770-777
Although l-3,4-dihydroxyphenylalanine (L-dopa) is one of the most effective therapies for Parkinson's disease, continued treatment may result in excessive involuntary movements known as L-dopa-induced dyskinesias (LIDs). Because LIDs can become dose-limiting, there is great interest in finding ways to ameliorate or prevent this troubling side effect of L-dopa therapy. It was recently reported that the D3 receptor partial agonist BP897 [N-[4-(4-(2-methoxyphenyl)piperazinyl)butyl]-2-naphthamide] reduces LIDs without diminishing antiparkinsonian effects of L-dopa in macaques. In the present study, we tested the effects of BP897 on LIDs in squirrel monkeys, a nonhuman primate particularly prone to dyskinesias. Parkinsonism was induced using 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. Animals were then gavaged with L-dopa/carbidopa (7.5 or 15 mg/kg/dose) without and with BP897. The effects of BP897 treatment were evaluated on several components of LIDs, including time course, peak dyskinesias, and area under the curve (AUC), a measure that encompasses both peak and duration of the response. Analyses of the time course and overall dyskinetic response (AUC) showed that BP897 significantly reduced LIDs but at the expense of the antiparkinsonian effect of L-dopa. BP897 had no significant effect on peak dyskinesias. Correlation studies showed that beneficial effects of BP897 on dyskinesias were linked to a decline in the antiparkinsonian action of L-dopa. Analyses of a subgroup of animals with mild/moderate parkinsonism yielded comparable results. Thus, in squirrel monkeys in contrast to macaques, BP897 fails to exert an antidyskinetic effect without diminishing the antiparkinsonian effects of L-dopa. These results suggest that BP897 may be less effective than originally anticipated for treating LIDs in Parkinson's disease. 相似文献