Functions of the endothelium and its role in hematopoietic cell transplantation

The endothelium is a single-layered structure that responds to physical and chemical signals with various factors it synthesizes. In the early days of its discovery, as the inner wall of the vessels, the endothelium was thought to be a simple barrier that lays on the surface. Over time it is discovered that endothelium maintains body homeostasis with the molecules it synthesizes, despite its simple single-layer structure. It has been accepted as an important organ that contributes to the maintenance of vascular tone, cell adhesion, inflammation, vascular permeability and coagulation. Any imbalance in these physiological and pathological events causes endothelial dysfunction. This can cause many diseases such as atherosclerosis, hypertension, diabetes, or it can occur because of these. Endothelial related disorders may also complicate hematopoietic stem cell transplantation (HSCT), which is used to treat various hematologic and neoplastic diseases. These life-threatening complications include graft-versus-host disease, hepatic veno-occlussive disease, transplant-associated thrombotic microangiopathy and diffuse alveolar hemorrhage. They share a similar pathophysiology involving endothelial cells with different clinical presentations. Therefore, current researche on the issue is putting the endothelium under the spotlight for novel markers and treatment options that should be used to monitor or treat at least some of these complications following HSCT.     

基于正交试验的肾造瘘管固定方案研究

目的 探讨基于正交试验的肾造瘘管不同固定方案的比较效果。方法 将14Fr硅胶肾造瘘管固定在聚乙烯展板和拉力显示器上，以固定材料、固定方法、面积为3个影响因素，每个因素3个水平，每组进行3次试验再求平均值作为最后拉力值F，共进行9个固定方案共27次试验。利用L9（33）正交试验矩阵研究不同材料（医用橡皮膏、医用透气胶带、医用无纺布胶带）、固定方法（交叉固定法、“工”字固定法和改良“工”字固定法）及面积(16 cm2、24 cm2、32 cm2）对肾造瘘管固定强度的影响。结果 正交试验所选的3种影响因素中，对拉力值影响显著性排序为：材料＞方法＞面积；3种固定材料中，医用橡皮膏固定强度最大。结论 肾造瘘管固定方案中，最佳固定组合为以医用橡皮膏结合改良“工”字法固定，可为临床管道固定方案的选择提供参考。     

Cáncer sincrónico de carcinosarcoma uterino y carcinoma seroso tubárico. A propósito de un caso y revisión de la bibliografía

We report a rare case of uterine carcinosarcoma involving a 74-year-old woman. The patient complained of posmenopausal bleeding. The disease was eventually diagnosed as simultaneous uterine carcinosarcoma and high-grade serous tubal carcinoma.Clinical examination found a cervical tumour and transvaginal ultrasound showed a heterogeneous intrauterine image. The histological result of both findings was carcinosarcoma.The computed tomography scan and magnetic resonance imaging reported similar findings for intrauterine and cervical tumour, with the same features as a possible myoma or mass with sarcomatous degeneration.Given the suspicion of a high-risk variant of endometrial adenocarcinoma, the primary management of carcinosarcoma is surgery. Complete surgical staging included total hysterectomy, bilateral salpingo-oophorectomy, omentectomy, pelvic and para-aortic lymph node dissection.The pathological findings revealed a uterine carcinosarcoma tumour, invading less than half the myometrium and the stromal connective tissue of the cervix but not extending beyond the uterus. The histopathological studies of bilateral adnexectomy and the peritoneal biopsy demonstrated the presence of high-grade serous tubal carcinoma. The lymph study was negative for malignancy.We concluded a synchronous diagnosis of uterine carcinosarcoma stage II and high-grade serous tubal carcinoma stage IIIB.A detailed literature search and management of this entity are discussed.     

Quantification of exhaled propofol is not feasible during single-lung ventilation using double-lumen tubes: A multicenter prospective observational trial

Background

Volatile propofol can be measured in exhaled air and correlates to plasma concentrations with a time delay. However, the effect of single-lung ventilation on exhaled propofol is unclear. Therefore, our goal was to evaluate exhaled propofol concentrations during single-lung compared to double-lung ventilation using double-lumen tubes.

Methods

In a first step, we quantified adhesion of volatile propofol to the inner surface of double-lumen tubes during double- and single-lumen ventilation in vitro. In a second step, we enrolled 30 patients scheduled for lung surgery in two study centers. Anesthesia was provided with propofol and remifentanil. We utilized left-sided double-lumen tubes to separately ventilate each lung. Exhaled propofol concentrations were measured at 1-min intervals and plasma for propofol analyses was sampled every 20 min. To eliminate the influence of dosing on volatile propofol concentration, exhalation rate was normalized to plasma concentration.

Results

In-vitro ventilation of double-lumen tubes resulted in increasing propofol concentrations at the distal end of the tube over time. In vitro clamping the bronchial lumen led to an even more pronounced increase (Δ AUC +62%) in propofol gas concentration over time. Normalized propofol exhalation during lung surgery was 31% higher during single-lung compared to double-lung ventilation.

Conclusion

During single-lung ventilation, propofol concentration in exhaled air, in contrast to our expectations, increased by approximately one third. However, this observation might not be affected by change in perfusion-ventilation during single-lung ventilation but rather arises from reduced propofol absorption on the inner surface area of the double-lumen tube. Thus, it is only possible to utilize exhaled propofol concentration to a limited extent during single-lung ventilation.

Registration of Clinical Trial

DRKS-ID DRKS00014788 ( www.drks.de ).