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991.
T-cell homeostasis is regulated by several molecules; among these, interleukin (IL)-7 plays an essential role in the survival and homeostatic proliferation of peripheral naive T cells. In a previous study, we investigated whether human mesenchymal stromal cells (MSCs) could be engineered with the IL-7 gene to produce functional level of this cytokine. In the present study, we analyzed the impact of different quantities of IL-7 produced by MSCs on the survival and proliferation of a negative immunoselected naive (CD3(+)/CD45RA(+)) T-cell population. Co-cultivation of peripheral naive T cells with MSCs producing low (16 pg/mL) or high (1000 pg/mL) IL-7 levels or in the presence of exogenous IL-7 (0.01 ng/mL and 100 ng/mL) maintained the CD3(+)/CD45RA(+) naive T-cell phenotype. Chemokine receptor CCR7(+) expression was also maintained among this T-cell population. Naive T-cell molecular characteristics were maintained as assessed by the Vbeta spectratyping complexity score, which showed the maintenance of a broad T-cell repertoire. No Th1 or Th2 differentiation was observed, as assessed by interferon-gamma or IL-4 accumulation. In contrast, only MSCs producing high amounts of IL-7 caused increased activation (CD25 31.2% +/- 12% vs 10% +/- 3.5%; P < .05), proliferation (CD71 17.8+/-7% vs 9.3%+/-3, P < .05), apoptosis (assessed by annexin V: 18.6% +/- 5% vs 14.9% +/- 2.6%; P > .05), and the phase S cell cycle (15% vs 6.9%, P > .05). Exogenous IL-7 exhibited no significant effect. In conclusion, we demonstrated that IL-7 produced by MSCs has a dose-independent effect on naive T-cell survival while exerting a dose-dependent effect on activation/proliferation. Due to the continuous production of IL-7 by engineered cells, our system is more efficacious than exogenous IL-7.  相似文献   
992.
One of the most important features of prolonged weightlessness is a progressive impairment of muscular function with a consequent decrease in exercise capacity. We tested the hypothesis that the impairment in musculo-skeletal function that occurs in microgravity results in a potentiation of the muscle metaboreflex mechanism and also affects baroreflex modulation of heart rate (HR) during exercise. Four astronauts participating in the 16 day Columbia shuttle mission (STS-107) were studied 72–71 days before launch and on days 12–13 in-flight. The protocol consisted of 6 min bicycle exercise at 50% of individual     followed by 4 min of postexercise leg circulatory occlusion (PECO). At rest, systolic (S) and diastolic (D) blood pressure (BP), R-R interval and baroreflex sensitivity (BRS) did not differ significantly between pre- and in-flight measurements. Both pre- and in-flight, SBP increased and R-R interval and BRS decreased during exercise, whereas DBP did not change. During PECO preflight, SBP and DBP were higher than at rest, whereas R-R interval and BRS recovered to resting levels. During PECO in-flight, SBP and DBP were significantly higher whereas R-R interval and BRS remained significantly lower than at rest. The part of the SBP response (Δ) that was maintained by PECO was significantly greater during spaceflight than before (34.5 ± 8.8 versus 13.8 ± 11.9 mmHg, P = 0.03). The tachycardic response to PECO was also significantly greater during spaceflight than preflight (−141.5 ± 25.2 versus −90.5 ± 33.3 ms, P = 0.02). This study suggests that the muscle metaboreflex is enhanced during dynamic exercise in space and that the potentiation of the muscle metaboreflex affects the vagally mediated arterial baroreflex contribution to HR control.  相似文献   
993.
PURPOSE: If medical schools increase enrollment to meet anticipated physician shortages, more students from alternate lists will likely be accepted. This study compared the performance of alternate- and main-list students during and one year after medical school. METHOD: The authors assessed admission and performance measures for 1,188 students matriculating from 1997-2003 at the University of Kansas School of Medicine. Measures included Medical College Admission Test scores, basic and clinical science grade point averages, United States Medical Licensing Examination Step 1 and Step 2 scores, residency match information, and residency director ratings. Chi-square analyses, proportional analyses, and independent t-tests were performed. RESULTS: The results indicated that both the admission measures and performance of alternate-list students were generally lower than main-list students, but the differences were small and probably not meaningful. CONCLUSIONS: As long as the applicant pool does not substantially change from its current makeup, increasing enrollment by accepting more students from alternate lists may not adversely affect overall student performance.  相似文献   
994.
Casali P  Pal Z  Xu Z  Zan H 《Trends in immunology》2006,27(7):313-321
Somatic hypermutation (SHM) underlies the generation of a diverse repertoire of high-affinity antibodies. It is effected by a two-step process: (i) DNA lesions initiated by activation-induced cytidine deaminase (AID), and (ii) lesion repair by the combined intervention of DNA replication and repair factors that include mismatch repair (MMR) proteins and translesion DNA synthesis (TLS) polymerases. AID and TLS polymerases that are crucial to SHM, namely polymerase (pol) theta, pol zeta and pol eta, are induced in B cells by the stimuli that are required to trigger this process: B-cell receptor crosslinking and CD40 engagement by CD154. These polymerases, together with MMR proteins and other DNA replication and repair factors, could assemble to form a multimolecular complex ("mutasome") at the site of DNA lesions. Molecular interactions in the mutasome would result in a "polymerase switch", that is, the substitution of the high-fidelity replicative pol delta and pol epsilon with the TLS pol theta, pol eta, Rev1, pol zeta and, perhaps, pol iota, which are error-prone and crucially insert mismatches or mutations while repairing DNA lesions. Here, we place these concepts in the context of the existing in vivo and in vitro findings, and discuss an integrated mechanistic model of SHM.  相似文献   
995.
996.
Mycobacterium tuberculosis is one of the leading causes of death worldwide, and multidrug-resistant tuberculosis (MDR-TB) is associated with a high case fatality rate. Rapid identification of resistant strains is crucial for the early administration of appropriate therapy, for prevention of development of further resistance, and to curtail the spread of MDR strains. The Genotype MTBDR (Hain Lifescience, Nehren, Germany) is a reverse hybridization line probe assay designed for the rapid detection of rpoB and katG gene mutations in clinical isolates. The ability of this technique to correctly identify resistant and MDR-TB strains was tested on 206 isolates from the Italian drug resistance surveillance system. This panel included the majority of MDR strains isolated in Italy in the past 3 years. The results of the test were compared to conventional drug susceptibility test performed on isolated strains and verified by sequencing the regions of interest of the bacterial genome. The rate of concordance between the results of the MTBDR and those obtained with "in vitro" sensitivity was 91.5% (130 of 142) for rifampin and 67.1% (116 of 173) for isoniazid. We also applied this test directly to a panel of 36 clinical specimens collected from patients with active TB. The MTBDR correctly identified the two cases of MDR-TB included in the panel. These results show that the MTBDR test is useful in the detection and management of tuberculosis when MDR disease is suspected.  相似文献   
997.
BackgroundWhilst there is a trend away from aggressive nonorgan sparing surgical treatments for malignant penile disease, a variety of penile preservation options exist but functional outcomes and patient reported outcomes (PROs) in this area are poorly reported to date.AimThe aim of this study is to report functional outcomes and PROs of total glans resurfacing (TGR) in a consecutive series of patients with lichen sclerosis (LS) or localized penile cancer (PC).MethodsFrom 2004 to 2018 a consecutive series of patients underwent TGR for the management of LS or localized PC in a tertiary referral network. Patient clinical records and operative notes were retrospectively reviewed. Statistical analysis was conducted with Stata 12.OutcomesUrinary and sexual outcomes were recorded utilizing both the International Index of Erectile Function (IIEF) and International Prostate Symptom Score (IPSS) validated questionnaires while PROs were extrapolated from a 5-item “ad hoc” telephone questionnaire administered at 1 year post procedure.Results37 consecutive patients were enrolled. Histology results demonstrated LS in 16 patients, with the remaining 21 having a diagnosis of PC. The most common reasons for patient presentation were local pain (32.4%), pruritus (37.8%) and bleeding (29.7%). Median follow-up was 22 (IQR 13–77) months. Median age was 62 (IQR 55–68).Neither of the questionnaires assessing urinary and sexual function showed any significant deterioration after surgery. Glans sensitivity was fully maintained in 89.2% of cases. 94.5% of patients reported to be fully satisfied with the aesthetic appearance of the penis and would consider undergoing the same procedure again if necessary. 91.9% of patients would recommend the same procedure to someone else. An overall improvement of the quality of life was reported by 86.4% of patients.Clinical ImplicationsTGR should be considered a treatment of choice for selected cases of benign or malignant penile lesionsStrengths and LimitationsOur study has some limitations, the first being its retrospective nature. Furthermore, despite being one of the largest series to date, follow-up duration is somewhat limited and a control group is lacking.ConclusionTGR represents an excellent surgical option ensuring satisfactory voiding and sexual function, as well as cosmesis for selected cases of penile lesions.M. Preto, M. Falcone, G. Blecher, et al. Functional and Patient Reported Outcomes Following Total Glans Resurfacing. J Sex Med 2021;18:1099–1103.  相似文献   
998.

Introduction  

This study was designed to investigate the putative anxiolytic-like activity of ultra-low doses of Gelsemium sempervirens (G. sempervirens), produced according to the homeopathic pharmacopeia.  相似文献   
999.

Background  

If spatial representations of hospitalization rates are used, a problem of instability arises when they are calculated on small areas, owing to the small number of expected and observed cases. Aim of this study is to assess the effect of smoothing, based on the assumption that hospitalization rates, when calculated at the municipal level, may be influenced by both the neighboring municipalities and the health service organization, as well as by environmental risk factors associated with the disease under study.  相似文献   
1000.
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