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21.
Oren Zusman Gregg S. Pressman Shmuel Banai Ariel Finkelstein Yan Topilsky 《JACC: Cardiovascular Imaging》2018,11(9):1225-1232
Objectives
The purpose of this study was to describe patients with severe symptomatic aortic stenosis with normal flow and low gradients and determine whether they benefit from intervention.Background
Severe symptomatic aortic stenosis is a progressive disease with high mortality. Although surgical aortic valve replacement (SAVR) or transcatheter aortic valve replacement (TAVR) are indicated for patients with high gradients (>40 mm Hg) or low gradients due to low flow, the approach for patients with normal flow and low gradients is poorly defined.Methods
Consecutive adult patients who underwent echocardiography between 2012 and 2015 at Tel-Aviv Medical Center and had an aortic valve area of ≤1.0 cm2, a mean gradient of <40 mm Hg, a stroke volume index of >35 ml/m2, and symptoms formed the study group. Patients designated for intervention (SAVR or TAVR) had their procedure within 6 months of the echocardiogram; the others were treated conservatively. The endpoints were all-cause mortality and cardiac-related mortality.Results
During the study period, 1,358 patients with an aortic valve area of ≤1.0 cm2 and symptoms were identified; 34% of these had normal flow and low gradient aortic stenosis and 303 were included. After mean follow-up of 652 days, 60 patients (20%) had died, with overall mortality rates of 28%, 10%, and 12% for conservatively treated, TAVR, and SAVR patients, respectively (p < 0.001). Using Cox regression with adjustment for other variables, TAVR was associated with improved survival versus conservative treatment (hazard ratio [HR]: 0.49; 95% confidence interval [CI]: 0.26 to 0.93; p = 0.03), and lower cardiac mortality (HR: 0.30; 95% CI: 0.10 to 0.74; p = 0.007) with no significant difference for SAVR versus TAVR. After propensity score matching of TAVR and conservatively treated patients, 25 of 94 (28%) conservatively treated and 10 of 94 (12%) TAVR patients had died (p = 0.016). In the matched cohort, Cox regression showed that TAVR had a significant association with improved survival (HR: 0.42; 95% CI: 0.20 to 0.86; p = 0.03).Conclusions
Symptomatic patients with an aortic valve area of ≤1.0 cm2, normal flow, and low gradient may benefit from intervention as opposed to conservative treatment. 相似文献22.
23.
Hyperbaric oxygen therapy improves angiogenesis and bone formation in critical sized diaphyseal defects
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JP Grassmann J Schneppendahl AR Hakimi M Herten M Betsch TT Lögters S Thelen M Sager M Wild J Windolf P Jungbluth M Hakimi 《Journal of orthopaedic research》2015,33(4):513-520
Besides the use of autologous bone grafting several osteoconductive and osteoinductive methods have been reported to improve bone healing. However, persistent non‐union occurs in a considerable number of cases and compromised angiogenesis is suspected to impede bone regeneration. Hyperbaric oxygen therapy (HBO) improves angiogenesis. This study evaluates the effects of HBO on bone defects treated with autologous bone grafting in a bone defect model in rabbits. Twenty‐four New‐Zealand White Rabbits were subjected to a unilateral critical sized diaphyseal radius bone defect and treated with autologous cancellous bone transplantation. The study groups were exposed to an additional HBO treatment regimen. Bone regeneration was evaluated radiologically and histologically at 3 and 6 weeks, angiogenesis was assessed by immunohistochemistry at three and six weeks. The additional administration of HBO resulted in a significantly increased new bone formation and angiogenesis compared to the sole treatment with autologous bone grafting. These results were apparent after three and six weeks of treatment. The addition of HBO therapy to autologous bone grafts leads to significantly improved bone regeneration. The increase in angiogenesis observed could play a crucial role for the results observed. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:513–520, 2015. 相似文献
24.
Protein C is a vitamin K-dependent plasma serine protease zymogen, which upon activation, functions as an anticoagulant. Protein C activation is catalyzed by a complex of thrombin (T) with thrombomodulin (TM). This activation is Ca(2+)-dependent, but Ca2+ inhibits protein C activation by thrombin alone. In most proteases, specificity is determined primarily by the residues that lie near the scissile bond. In protein C, the P2 position is Pro, whereas in the fibrinogen A chain, P2 is Val. We have expressed a Pro-->Val mutant of protein C (P168V) in mammalian cells. At saturating Ca2+, the P168V and wild-type proteins were activated by the T-TM complex equivalently, but half maximal rates of activation were obtained at 50 mumol/L Ca2+ for wild type and approximately 5 mmol/L Ca2+ for the P168V mutant. In the absence of TM, Ca2+ no longer inhibited the activation of the P168V mutant. These results indicate that Pro168 influences the Ca(2+)- dependent conformational changes in protein C that control activation. Recently, a patient with thrombotic complications has been identified with a Pro168-->Leu substitution. Both the P168V and the P168L mutation lead to impaired secretion caused by retention within the cell. 相似文献
25.
The existence and characteristics of bone marrow T-cell progenitors have not yet been established in man. Several pieces of evidence such as the reconstitution of certain immunodeficiencies by bone marrow graft suggest that T-cell precursors are present in the bone marrow. We report the growth of T-cell colonies from bone marrow populations using PHA-stimulated lymphocyte-conditioned medium containing T-cell growth factor (TCGF). Rosetting experiments and complement-dependent cytotoxicity assays with monoclonal antibodies indicate that the bone marrow T colony-forming cells (T-CFC) are E- OKT 3- and la+, i.e., immature progenitors. The colonies derived from these cells have the phenotype of mature T cells: E + OKT 3 + la- with either helper (OKT 4+) and suppressor (OKT 8 +) antigens. These results suggest that a thymic microenvironment may not be necessary for the in vitro proliferation and differentiation of the T-cell lineage in adult humans. These methodologies may permit direct investigation of early phenomena concerning the T-cell lineage, such as the acquisition of self-tolerance, the formation of a repertoire of specificities, and the HLA restriction phenomena that we believe takes place before the thymic maturation. 相似文献
26.
27.
Pressman GS Figueredo VM Romero-Corral A Murali G Kotler MN 《The American journal of cardiology》2012,109(7):1055-1059
Obstructive apneas produce high negative intrathoracic pressure that imposes an afterload burden on the left ventricle. Such episodes might produce structural changes in the left ventricle over time. Doppler echocardiograms were obtained within 2 months of attended polysomnography. Patients were grouped according to apnea-hypopnea index (AHI): mild/no obstructive sleep apnea (OSA; AHI <15) and moderate/severe OSA (AHI ≥15). Mitral valve tenting height and area, left ventricular (LV) long and short axes, and LV end-diastolic volume were measured in addition to tissue Doppler parameters. Comparisons of measurements at baseline and follow-up between and within groups were obtained; correlations between absolute changes (Δ) in echocardiographic parameters were also performed. After a mean follow-up of 240 days mitral valve tenting height increased significantly (1.17 ± 0.12 to 1.28 ± 0.17 cm, p = 0.001) in moderate/severe OSA as did tenting area (2.30 ± 0.41 to 2.66 ± 0.60 cm(2), p = 0.0002); Δtenting height correlated with ΔLV end-diastolic volume (rho 0.43, p = 0.01) and Δtenting area (rho 0.35, p = 0.04). In patients with mild/no OSA there was no significant change in tenting height; there was a borderline significant increase in tenting area (2.20 ± 0.44 to 2.31 ± 0.43 cm(2), p = 0.05). Septal tissue Doppler early diastolic wave decreased (8.04 ± 2.49 to 7.10 ± 1.83 cm/s, p = 0.005) in subjects with moderate/severe OSA but not in in those with mild/no OSA. In conclusion, in patients with moderate/severe OSA, mitral valve tenting height and tenting area increase significantly over time. This appears to be related, at least in part, to changes in LV geometry. 相似文献
28.
29.
Temporal artery biopsy is considered the gold standard investigation of giant cell arteritis and is recommended in suspected cases despite a sensitivity of 81–91%. This review highlights the potential risk of facial nerve injury during temporal artery biopsy and introduces recent advances in the emerging role of imaging modalities. When these non-invasive techniques are used in conjunction with American College of Rheumatology scoring, which includes clinical features and biochemical test results, temporal artery biopsy may be avoided in selected cases. 相似文献
30.
DK Bilku AR Dennison TC Hall MS Metcalfe G Garcea 《Annals of the Royal College of Surgeons of England》2014,96(1):15-22