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71.
Khaled Adil Marija Popovic Fabio L. Cury Sergio L. Faria Marie Duclos Luis Souhami 《Practical radiation oncology》2019,9(1):24-28
Purpose
This study aimed to investigate 3 planning target volume (PTV) margin expansions and determine the most appropriate volume to be used in bladder preservation therapy when using daily cone beam computed tomography (CBCT). We aimed to establish whether a smaller PTV expansion is feasible without risking geographical miss.Methods and materials
The study included patients with bladder cancer who were treated with a hypofractionated course of radiation therapy delivered with intensity modulated radiation therapy. The clinical target volume (CTV) was the whole empty bladder, and the PTV consisted of a 1.5-cm margin around the bladder (PTV1.5 cm). Patients underwent daily CBCT imaging before treatment to assess the bladder volume and ensure accurate positioning. We investigated 2 additional smaller PTV margin expansions to determine the most appropriate volume to be used with CBCT as a daily image guided radiation therapy modality. These margins were created retrospectively on every CBCT. The first additional volume was a uniform PTV margin of the surrounding 1 cm (PTV1 cm). When considering that the majority of the internal bladder movement was due to the variation in filling that occurs in the superior and anterior directions, a second volume of an anisotropic PTV margin with a 1.5-cm superior/anterior and 1 cm in other directions (PTV1/1.5 cm) was created. We recorded the frequency and measured the volume of bladder falling out of each PTV based on the daily CBCT.Results
For the purpose of this study, we considered an arbitrary 5 cm3 of CTV falling out of the designated PTV as a clinically significant volumetric miss. The frequency of such a miss when applying the uniform PTV1 cm was 1%. However, when applying the uniform PTV1.5 cm and anisotropic PTV1/1.5 cm margins, the frequency was 0.5% and 0.5%, respectively.Conclusions
The anisotropic PTV expansion of 1.5 cm superiorly and anteriorly and 1 cm in all other directions around the bladder (CTV) provides a safe PTV approach when daily CBCT imaging is used to localize an empty bladder. 相似文献72.
Melatonin reduces oxidative stress and improves vascular function in pulmonary hypertensive newborn sheep
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Flavio Torres Alejandro González‐Candia Camilo Montt Germán Ebensperger Magdalena Chubretovic María Serón‐Ferré Roberto V. Reyes Aníbal J. Llanos Emilio A. Herrera 《Journal of pineal research》2015,58(3):362-373
Pulmonary hypertension of the newborn (PHN) constitutes a critical condition with severe cardiovascular and neurological consequences. One of its main causes is hypoxia during gestation, and thus, it is a public health concern in populations living above 2500 m. Although some mechanisms are recognized, the pathophysiological facts that lead to PHN are not fully understood, which explains the lack of an effective treatment. Oxidative stress is one of the proposed mechanisms inducing pulmonary vascular dysfunction and PHN. Therefore, we assessed whether melatonin, a potent antioxidant, improves pulmonary vascular function. Twelve newborn sheep were gestated, born, and raised at 3600 meters. At 3 days old, lambs were catheterized and daily cardiovascular measurements were recorded. Lambs were divided into two groups, one received daily vehicle as control and another received daily melatonin (1 mg/kg/d), for 8 days. At 11 days old, lung tissue and small pulmonary arteries (SPA) were collected. Melatonin decreased pulmonary pressure and resistance for the first 3 days of treatment. Further, melatonin significantly improved the vasodilator function of SPA, enhancing the endothelial‐ and muscular‐dependent pathways. This was associated with an enhanced nitric oxide‐dependent and nitric oxide independent vasodilator components and with increased nitric oxide bioavailability in lung tissue. Further, melatonin reduced the pulmonary oxidative stress markers and increased enzymatic and nonenzymatic antioxidant capacity. Finally, these effects were associated with an increase of lumen diameter and a mild decrease in the wall of the pulmonary arteries. These outcomes support the use of melatonin as an adjuvant in the treatment for PHN. 相似文献
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淋巴管作为循环系统的重要组成部分之一,具有调节机体体液稳态,协助免疫监视和肠道脂质吸收等重要作用。淋巴管新生是机体生理和病理过程中维持脉管系统结构和功能正常的重要手段,淋巴管新生调控对于防治肿瘤、心血管等诸多疾病有着潜在的临床转化意义;淋巴回流功能则与关节炎症等疾病发病机制关系密切。在循环系统中,相较于中医药调控血管相关疾病的发病机制已取得很大进展,近年来对于淋巴管的研究则明显相对滞后。本文从中医药作用于淋巴管新生及回流功能角度对这一领域的研究进展作一综述,以期为临床上中医药治疗相关疾病提供新的思路与方法。 相似文献
76.
Ngai-Yin Chan Chi-Chung Choy Ho-Chuen Yuen Hoi-Fan Chow Ho-Fai Fong 《The Canadian journal of cardiology》2019,35(4):396-404
Background
Persistent iatrogenic atrial septal defect (iASD) is a common but poorly characterized complication after cryoballoon (CB) pulmonary vein isolation (PVI) procedures. We therefore investigate its prevalence, evolution, risk factors, and clinical outcomes in a prospective longitudinal study.Methods
A total of 108 patients (41 women, mean age 57 ± 11.3) underwent CB PVI for AF. Serial transesophageal echocardiography (TEE) was performed 9 months and then annually until 6 years after the procedure to study the characteristics of persistent iASD.Results
Persistent iASD occurred in 33 (30.6%) patients 9 months after CB PVI. Spontaneous closure of iASD was found in 6 (22.2%) and 3 (15.8%) patients 2 and 3 years after the procedures, respectively. No spontaneous closure was observed on 4, 5, and 6-year TEE follow-up. The projected long-term persistence rate of iASD after CB PVI was therefore 20% (30.6% × 0.778 × 0.842). Using multivariate logistic regression, a higher number of cryoapplications (≥ 2 minutes) was the only independent predictor of persistent iASD 9 months after CB PVI (odds ratio [OR] 1.207; 95% confidence interval [CI], 1.033-1.411, P = 0.018). Two (1.9%) patients with significantly larger iASD size than the others (long diameter 12.6 ± 0.8 vs 3.7 ± 1.5 mm, P < 0.001; short diameter 10.9 ± 0.2 vs 3 ± 1.1 mm, P < 0.001) required percutaneous closure because of exertional dyspnea and right ventricular enlargement. Over 129.7 patient-years follow-up, during which iASD persisted, there was no occurrence of neurologic events.Conclusions
Approximately one fifth of patients undergoing CB PVI will have permanently persistent iASD. Patients with defect sizes of greater than 10 mm may need percutaneous closure due to significant left-to-right shunting. 相似文献77.
78.
This paper investigates the quantized sliding mode control of Markov jump systems with time‐varying delay. A dynamical adjustment law is explored to quantize the system output. By constructing an observer‐based integral sliding surface, a sliding mode controller is designed to take over the dynamical motion of state estimation and ensure the reachability of sliding surface. A new scaling manner is developed to build the bound between the system output and quantized error. With the help of separation strategies for controller synthesis and general transition probabilities and a lower bound theorem for nonlinear integral terms, a new synthesis method to ensure the required stability and meet the required performance is proposed in the form of linear matrix inequalities. The validity of the proposed control method is illustrated by a numerical example. 相似文献
79.
80.
Joobin Sattar Adi Kartolo Wilma M. Hopman Joshua Matthew Lakoff Tara Baetz 《Journal of Geriatric Oncology》2019,10(3):411-414
ImportanceImmunotherapy has emerged as an effective treatment option for the management of advanced cancers. The effects of these immune checkpoint inhibitors in the older patient population has not been adequately assessed.ObjectiveTo understand the impact of aging on CTLA-4 and PDL-1 inhibitors efficacy and immune-related adverse events (irAE) in the context of real-world management of advanced solid cancers.Design, Setting, and ParticipantsThis retrospective study involved all non-study patients with histologically-confirmed metastatic or inoperable solid cancers receiving immunotherapy at Kingston Health Sciences Centre. We defined ‘older patient’ as age ≥ 75. All statistical analyses were conducted under SPSS IBM for Windows version 24.0.Main Outcomes and MeasuresStudy outcomes included immunotherapy treatment response, survival, as well as number, type, and severity of irAEs.ResultsOur study (N = 78) had 29 (37%) patients age <65, 26 (33%) patients age 65–74, and 23 (30%) patients age ≥75. Melanoma, non-small cell lung cancer, and renal cell carcinoma accounted for 70%, 22%, and 8% of the study population, respectively. Distributions of ipilimumab (32%), nivolumab (33%), and pembrolizumab (35%) were similar in the study. The response rates were 28%, 27%, and 39% in the age <65, age 64–74, age ≥75 groups, respectively (P = 0.585). Kaplan-Meier curve showed a median survival of 28 months (12.28–43.9, 95% CI) and 17 months (0–36.9, 95% CI) in the age <65 and age 64–74 groups, respectively; the estimated survival probability did not reach 50% in the age ≥75 group (P = 0.319). There were no statistically significant differences found in terms of irAEs, multiple irAEs, severity of grade 3 or higher, types of irAEs, and irAEs resolution status when comparing between different age groups.Conclusion and RelevanceOur results suggest that patients age ≥75 are able to gain as much benefit from immunotherapy as younger patients, without excess toxicity. Our findings suggest that single agent immunotherapy is generally well-tolerated across different age groups with no significant difference in the type, frequency or severity of irAEs. Future studies evaluating aging and combination immunotherapy are warranted. 相似文献