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41.
42.
D. J. Anderson L. Olaison J. R. McDonald J. M. Miro B. Hoen C. Selton-Suty T. Doco-Lecompte E. Abrutyn G. Habib S. Eykyn P. A. Pappas V. G. Fowler D. J. Sexton M. Almela G. R. Corey C. H. Cabell 《European journal of clinical microbiology & infectious diseases》2005,24(10):665-670
Enterococcal prosthetic valve infective endocarditis (PVE) is an incompletely understood disease. In the present study, patients
with enterococcal PVE were compared to patients with enterococcal native valve endocarditis (NVE) and other types of PVE to
determine differences in basic clinical characteristics and outcomes using a large multicenter, international database of
patients with definite endocarditis. Forty-five of 159 (29%) cases of definite enterococcal endocarditis were PVE. Patients
with enterococcal PVE were demographically similar to patients with enterococcal NVE but had more intracardiac abscesses (20%
vs. 6%; p=0.009), fewer valve vegetations (51% vs. 79%; p<0.001), and fewer cases of new valvular regurgitation (12% vs. 45%; p=0.01). Patients with either enterococcal PVE or NVE were elderly (median age, 73 vs. 69; p=0.06). Rates of in-hospital mortality, surgical intervention, heart failure, peripheral embolization, and stroke were similar
in both groups. Patients with enterococcal PVE were also demographically similar to patients with other types of PVE, but
mortality may be lower (14% vs. 26%; p=0.08). Notably, 93% of patients with enterococcal PVE came from European centers, as compared with only 79% of patients with
enterococcal NVE (p=0.03). Thus, patients with enterococcal PVE have higher rates of myocardial abscess formation and lower rates of new regurgitation
compared to patients with enterococcal NVE, but there are no differences between the groups with regard to surgical or mortality
rates. In contrast, though patients with enterococcal PVE and patients with other types of PVE share similar characteristics,
mortality is higher in the latter group. Importantly, the prevalence of enterococcal PVE was higher in the European centers
in this study. 相似文献
43.
44.
Pérez C Tous M Gallego S Zala N Rabinovich O Garbiero S Martínez MJ Cunha AM Camino S Cámara A Costa SC Larrondo M Francalancia V Landreau F Bartomioli MA 《Journal of medical virology》2004,72(4):661-667
Human herpesvirus-8 (HHV-8) causes Kaposi's sarcoma (KS) and lymphoproliferative disorders in both HIV-infected and uninfected patients. HHV-8 has a worldwide occurrence but infection rates vary according to a combination of geographic and behavioral risks. The main transmission route seems to be sexual, nevertheless, nasal secretions, saliva, blood, and organ graft have been proposed. HHV-8 was postulated as a new infectious agent for screening in blood donors. The aim of this study was to evaluate the prevalence of antibodies against HHV-8 antigens in blood donors of South America. Serum samples from 2,470 blood donors from Argentina, Brazil, and Chile corresponding to five geographic regions were studied by indirect immunofluorescence assay (IFA). Seroprevalence rate was 3.7% (92/2,470; 95% CI 2.9-4.5) in the entire blood donor population distributed as follows: Argentina, 4.0% (Buenos Aires city, 4.3%; Bahia Blanca, 2.4%; and Córdoba, 4.0%), Campinas (Brazil), 2.8%; and Santiago de Chile, 3.0%. There was no difference (P>0.05) between men and women or age related, except in Brazil where positive cases were 30-49-year-old males. The present study, which includes different geographical areas of multiple countries from South America, has not been done before. The results show similar prevalence rates among the studied zones corresponding to low-prevalence regions. South America is a large sub-continent with a wide spectrum of population and geographical characteristics, thus, more HHV-8 prevalence studies should be necessary to establish possible regional differences. 相似文献
45.
Thoracic and retroperitoneal spindle-cell lesions represent a diagnostic challenge in the evaluation of fine-needle aspiration (FNA) specimens. The challenge is due to the morphologic similarities and wide variety of different entities with spindle-cell morphology in these two sites. The purpose of this study was to identify criteria helpful in the classification and differential diagnosis of spindle-cell lesions in these two locations. A set of cytologic features was analyzed in 57 thoracic or retroperitoneal spindle-cell lesions. Our results show that pleomorphism and abundant single cells were parameters associated with high-grade tumors in univariate and multivariate analysis, while coarse chromatin pattern was significant only in a univariate analysis. The combination of absence of pleomorphism, rare single cells, tight cluster arrangement, fine chromatin pattern, and absence of macronucleoli was seen only in benign cases. Assessment of background material was helpful in the differential diagnosis and classification. Necrosis was only found in high-grade cases. 相似文献
46.
Oscar A. M. Wyss 《Pflügers Archiv : European journal of physiology》1967,295(2):136-146
Zusammenfassung Bei der Mittelfrequenz-Impuls-Reizung ist streng darauf zu achten, daß keine polaritären Reizkomponenten auftreten. Die diesbezügliche Kontrolle wird am besten mit Hilfe des Konvertibilitätstestes vorgenommen, d. h., es darf beim Vertauschen der Zuführungen zu den Reizelektroden weder die Reizschwelle bzw. die Größe des kollektiven Reizerfolges noch dessen Latenzzeit eine signifikante Änderung erfahren. Auf diese Weise wird die Phasenunabhängigkeit des echten Mittelfrequenz-Reizeffektes nachgewiesen.Diesen Anforderungen entsprechen Mittelfrequenz-Impulse, deren Trägerfrequenz über einige wenige Perioden sich aufschaukelt und ebenso wieder abklingt. Demgegenüber sind Mittelfrequenz-Stromstöße mit phasenstarrem Einsatz und Ende nicht unbedingt frei von polaritären Ein- bzw. Ausschalt-effekten, indem sowohl die erste als auch die letzte Trägerperiode einen polaritären Wechselimpuls-Reizeffekt ergeben kann, je nach Phasenlage bezogen auf die wirksame Reizelektrode und Art der Ansprechbarkeit des Reizobjektes (Nerv) auf entsprechend kurze gleitspiegelsymmetrische Wechselimpulse. Für eine echte Mittelfrequenz-Stromstoß-Reizung ist demnach ebenfalls ein Aufschaukeln und Abklingen der Trägerfrequenz über einige wenige Perioden erforderlich.Es besteht ein prinzipieller Unterschied zwischen der echten Mittelfrequenz-Reizung, die phasen -bzw. periodenunabhängig ist und schon früher als apolaritär bezeichnet wurde, und der konventionellen polaritären Reizung, die als polaritäre Komplikation der Mittelfrequenz-Reizung auftreten kann.Diese Präzisierung der Reizwirkung mittelfrequenter Wechselströme wurde angeregt durch zwei im Text erwähnte Publikationen, in denen in keineswegs überzeugender Weise versucht wird, die Mittelfrequenz-Reizung letzten Endes auf das polare Gesetz der Erregung zurückzuführen.
Summary The particular excitatory action exerted by middle-frequency alternating current can only be revealed if care is taken to eliminate the occurrence of so-called polarity effects. Such effects are produced by the short alternating impulses represented by the first and the last period of a middle-frequency current pulse and are based on the polar law of excitation.In order to prevent such polarity intrusions, it is necessary to increase and decrease the amplitude of the middle-frequency current pulses over a few carrierperiods, or, to use amplitude-modulated middle-frequency impulses of variable shape and duration of envelope.A true middle-frequency excitatory effect is easily demonstrated by resorting to the convertibility test. It will then become evident that stimulation threshold, magnitude as well as latency of response do not change during reversal of the stimulating poles. This means, that no significant phase change of the response with regard to the carrier-frequency occurs when the leads to the stimulating electrodes are commuted, and that, as a result, true middle-frequency effects do not depend upon one particular catelectrotonic variation among the carrier-periods of a middle-frequency current pulse.It can thus be concluded that a fundamental difference exists between true middle-frequency stimulation, which is based on a non-polarity or apolarity principle, and the conventional stimulation of the polar or polarity type.This paper has been written in the hope of dispelling some errors of interpretation (discussed in the text) tending to ascribe the excitatory effects of middle-frequency impulse stimulation to the classical polar law of excitation.相似文献
47.
Montserrat Plana Odette Vias Oscar de la Calle-Martin Francisco Lozano Julia Ingls-Esteve Matilde Romero Jos Alberola-Ila Jordi Yagüe Ramn Vilella Jordi Vives 《European journal of immunology》1991,21(4):1085-1088
The ability of the 134-2C2 monoclonal antibody (mAb; CD26) to transmit an activation signal and to affect T cell proliferation has been studied. The 134-2C2 mAb, although not being mitogenic by itself, is able to increase the proliferation of purified T cells in the presence of exogenous interleukin 2 (IL2) or phorbol 12-myristate 13-acetate (PMA). No effect of our mAb was observed on the proliferation of T cells induced by other stimuli such as Sepharose-bound CD3 mAb, phytohemagglutinin or calcium ionophore. Since the co-stimulatory effect of 134-2C2 mAb on PMA-induced T cell proliferation was strongly inhibited by an anti-Tac antibody, its involvement on the IL2/IL2 receptor pathway was investigated. An increased IL2 secretion in T cells cultured with PMA plus 134-2C2 mAb was observed and Northern blot analysis showed that the mAb 134-2C2 acts synergistically with PMA favoring the induction of both IL2 and interferon-γ mRNA synthesis, as well as the enhancement of IL2 receptor and transferrin receptor mRNA expression. Studies on mechanisms implicated in signal transduction showed that 134-2C2 mAb modifies neither intracellular calcium levels nor phosphoinositide breakdown. Additionally, no effect was exerted on protein kinase C translocation. These data suggest that the CD26 antigen is involved in T cell activation in an IL2/IL2 receptor-dependent pathway. 相似文献
48.
Cellular mechanisms of the adjuvant activity of the flagellin component FljB of Salmonella enterica Serovar Typhimurium to potentiate mucosal and systemic responses 总被引:1,自引:0,他引:1
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An expanding area of interest is the utilization of microbe-based components to augment mucosal and systemic immune responses to target antigens. Thus, the aim of the present study was to assess if the flagellin component FljB from Salmonella enterica serovar Typhimurium could act as a mucosal adjuvant and then to determine the cellular mechanism(s) by which FljB mediates its adjuvant properties. To determine if FljB could act as a mucosal adjuvant, mice were immunized by the intranasal (i.n.) route with antigen alone or in conjunction with FljB. Additionally, we assessed how FljB affected the levels of the costimulatory molecules B7-1 and B7-2 on dendritic cells by flow cytometry and determined the functional role these costimulatory molecules played in the adjuvant properties of FljB in vivo. Mice immunized by the i.n. route with antigen and FljB exhibited significantly elevated levels of mucosal and systemic antibody and CD4(+)-T-cell responses compared to mice given antigen only. Stimulation of dendritic cells in vitro with FljB resulted in a pronounced increase in the surface expression of B7-1 and B7-2. The percentage of dendritic cells expressing B7-2 but not B7-1 increased significantly when stimulated with FljB over a concentration range of 10 to 10,000 ng/ml. Immunization of wild-type and B7-1, B7-2, and B7-1/2 knockout mice by the i.n. route revealed that the ability of FljB to increase B7-2 expression is largely responsible for its adjuvant effect in vivo. These findings demonstrate that FljB can act as an effective mucosal adjuvant and that its ability to enhance the level of B7-2 expression is predominantly responsible for its adjuvant properties. 相似文献
49.
Isabel Campos-Varela Oscar Len Ares Villagrasa Ester Márquez-Algaba Juliana Esperalba Cristina Dopazo Ibai Los-Arcos Andrés Antón Lluís Castells 《Transplant international》2021,34(10):1908-1913
Solid organ transplant recipients might be at greater risk for acquisition and mortality because of SARS-CoV-2. There are no data regarding SARS-CoV-2 seroprevalence among liver transplant (LT) recipients, and whether it is different from that of the general population or other immunosuppressed groups. We evaluated the prevalence of IgG SARS-CoV-2 antibodies among LT recipients to estimate the frequency of asymptomatic SARS-CoV-2 infection using serological assays in our outpatient clinic. We conducted a cross-sectional analysis from 10 May to 26 October 2020 of all adult (>18 years) LT recipients that underwent a routine laboratory test for the outpatient clinic follow-up at the Hospital Universitari Vall d’Hebron (Barcelona) in which we included serological testing for SARS-CoV-2. Nine out of 294 LT recipients (3.1%) tested positive for anti-SARS-CoV-2 IgG antibodies. Five of them (55.5%) had suffered clinically symptomatic SARS-CoV-2 infection confirmed by RT-PCR, four (44.4%) had presented compatible symptoms but without microbiological confirmation and only one patient (1/9, 11.1%) tested positive without any previous symptom. SARS-CoV-2 seroprevalence among LT recipients in an area highly affected by the pandemic is lower than in the general population in the same area. These results render the possibility of asymptomatic infection in LT recipients very unlikely. 相似文献
50.
Helena Sousa Oscar Ribeiro Elísio Costa Roberta Frontini Constana Paúl Leonilde Amado Vasco Miranda Fernando Ribeiro Daniela Figueiredo 《Seminars in dialysis》2021,34(1):66-76
For individuals with end‐stage renal disease (ESRD), the novel coronavirus can present several additional challenges in disease self‐management. This study aimed to explore the impacts of the COVID‐19 pandemic in non‐COVID‐19 patients with ESRD undergoing in‐center hemodialysis (HD). A mixed‐methods study was conducted with a purposive sample recruited from one dialysis unit in Portugal. Quantitative data were collected retrospectively from patients' medical records from February 2020 (T1—before the outbreak) and from April 2020 (T2—during lockdown). Semi‐structured interviews were conducted with 20 patients (66.9 ± 11.9 years old) undergoing HD for an average of 46.1 months (±39.5) in April 2020. Overall results suggested that dialysis adequacy and serum albumin levels decreased significantly at T2, while phosphorus levels increased. The findings from thematic analysis suggested several psychosocial negative impacts and impacts on disease and treatment‐related health behaviors (eg, difficulties managing dietary restrictions during the lockdown and diminished physical activity), which can partially explain these quantitative results. However, some patients were also able to find positive impacts in this experience and problem‐focused and emotional strategies were identified to cope with the demands of COVID‐19. Several recommendations have been made to mitigate patients’ emotional, relational, and educational unmet needs during the current pandemic and in the event of new outbreaks. 相似文献