Effects of age,gender and menstrual cycle on platelet function assessed by impedance aggregometry

Platelets are needed to prevent or arrest bleeding and aggregate at the site of injury upon vascular damage. Platelets express receptors for estrogens which might affect the function of the platelets and their hemostatic ability. The aim was to identify possible differences in platelet function related to age, gender, and phases of the menstrual cycle by use of impedance aggregometry with Multiplate. In the first part of the study, platelet function was assessed in 60 healthy individuals (30 men and 30 women) in each of three age groups (20–25, 40–45, and 60–65 years). In the second part of the study, the platelet function was analyzed on four occasions during the menstrual cycle in women without oral contraceptives (OCs) (n = 17) and compared to 19 women on OCs and 18 men of similar age (20–40 years). For the women on OCs, aggregation was analyzed once during the tablet-free week and once late during the period with OCs. The men were sampled once. Women of younger age (<45 years) had significantly higher agonist-induced aggregation response than both men and post-menopausal women (60–65 years). The agonist-induced aggregation response did not differ between phases of the menstrual cycle or OC use. The results suggest that estradiol and/or progesterone affect spontaneous aggregation since it was found to be lowest in the mid-luteal phase. Spontaneous aggregation was significantly lower in women on OCs than in both men and women without OCs. Our findings indicate that fertile age is associated with higher aggregation response capacity of the platelets, possibly to prevent excessive bleeding during menstruation, but this response capacity is not altered during the menstrual cycle or by use of OCs.     

Balloon Pulmonary Angioplasty for the Treatment of Nonoperable Chronic Thromboembolic Pulmonary Hypertension: Single-Center Experience with Low Initial Complication Rate

PurposeTo evaluate the safety and efficacy of balloon pulmonary angioplasty (BPA) for nonoperable chronic thromboembolic pulmonary hypertension (CTEPH) patients during the initial experience of a single center.MethodsA total of 18 CTEPH patients (5 with residual pulmonary hypertension after pulmonary endarterectomy) were treated with BPA during the period 2014–2018 and were retrospectively reviewed. Mean age was 61 ± 19 years; 55% were female; mean pulmonary artery pressure was 44 ± 12 mmHg; cardiac output was 4.3 ± 1.0 l/min; and pulmonary vascular resistance was 8.4 ± 3.6 WU. Patients were evaluated by New York Heart Association functional class, 6-minute walk distance, N-terminal pro b-type natriuretic peptide, echocardiography, right heart catheterization, and before and after completions of BPA.ResultsA total of 91 procedures were performed, with a median number of 4 BPA sessions per patient (range, 2–8). There were no deaths or major complications requiring extracorporeal support or (non)invasive ventilation. The most common complication was self-limiting hemoptysis (3%). According to Society of Interventional Radiology classification, 4 mild, 4 moderate, and 1 severe adverse events were noted. Invasive hemodynamics significantly improved, with a cardiac index increase of 15% (P = .0333), decrease of mean pulmonary artery pressure of 30% (P = .0013), and decrease of pulmonary vascular resistance of 45% (P = .0048). Stroke volume index (P = .0171) and pulmonary arterial compliance (P = .0004) were also significantly enhanced.ConclusionsBPA significantly improves cardiopulmonary hemodynamics with an acceptable safety profile. Further studies assessing the long-term efficacy of BPA are required.     

Individualized 3D-printed templates for high-dose-rate interstitial multicathether brachytherapy in patients with breast cancer

Purpose

High-dose-rate, multicatheter interstitial brachytherapy is technically complex and operator-dependent, requiring lengthy training and specialized skills. Furthermore, until the advent of contouring on computerized tomography (CT) images, difficulties existed in locating the target volume precisely. The present article reports the results of a study that aimed at producing and validating a 3D-printed template to aid in target volume localization for multicatheter interstitial brachytherapy in patients with breast cancer.

颈内静脉内径呼吸变异度和血流速度在椎管内麻醉后容量预测中的价值

目的探究超声测量颈内静脉内径呼吸变异度和血流速度在椎管内麻醉后血容量判断中的价值。方法选择我院2017年2月至2019年2月择期手术的椎管内麻醉患者120例,男64例,女56例,年龄为34～66岁,ASAⅠ或Ⅱ级。记录麻醉前、麻醉后5、15、25 min左侧颈内静脉最大直径(Dmax)、最小直径(Dmin)、内径呼吸变异度(RVI)、中心静脉压(CVP)、血流速度最大值(BVmax)、血流速度最小值(BVmin)和血流速度变异度(BVI),取CVP=6 mmHg作为预测值,并通过绘制ROC曲线来评估Dmax、Dmin、RVI、BVmax、BVmin和BVI的预测效能。结果与麻醉前比较,麻醉后5 min时Dmax、Dmin和BVI明显降低(P0.05),RVI明显升高(P0.05);与麻醉后5和15 min比较,麻醉后25 min,Dmax、Dmin和BVI明显升高(P0.05),RVI明显降低(P0.05)。麻醉前BVmin的AUC值最大为0.958,临界值6.86,敏感性82.6%,特异性95.2%;麻醉后5 min,Dmin的AUC值最大为0.944,临界值0.74,敏感性98.4%,特异性84.3%;麻醉后15 min,Dmin和BVmax的AUC值最大分别为0.949和0.945,临界值分别为0.72和7.99,敏感性分别为96.5%和89.8%,特异性分别为82.4%和82.1%;麻醉后25 min,BVmax的AUC值最大为0.981,临界值8.98,敏感性92.0%,特异性90.5%。结论超声测量患者颈内静脉的内径变异度和血流速度可作为预测椎管内麻醉后血容量的方式。     

Racial differences in hemoglobin and plasma volume variation: implications for muscle performance and recovery

Objective: To examine the effect of race differences on sprint performance, Hemoglobin (Hb), Hematocrit (Ht) and plasma volume (PV) variation in response to repeated sprint exercise.

Design: Thirty-six healthy, moderately trained men and women (20.8?±?0.2 year-old) volunteered to participate in this study. They were allocated to one of the four groups according to their gender and race: Black men’s group (BM, n?=?9), White men’s group (WM, n?=?9), Black women’s group (BW, n?=?9) and White women’s group (WW, n?=?9). All participants performed the running-based anaerobic sprint test (RAST), which consists of six?35-m sprints with 10 s of recovery in-between. Six venous blood samples were collected to determine Hb, Ht and PV levels at rest, after warm-up, immediately post- and at 5, 15 and 30 min post-RAST. Blood lactate is also sampled during the 3rd minutes of recovery.

Results: The best running time was significantly shorter (P?=?.002) in BW compared to WW. We have observed significantly higher Hb (P?=?.010) and Ht (P?=?.004) levels in BW compared to WW during the 5th minute of recovery. During RAST, the PV decreased significantly (P?=?.007) in WM only. Black groups had lower (P?<?.05) lactate levels compared to the white subjects. During recovery, PV increase was significantly (P?=?.003) higher in WW compared to BW during the 5th minute of recovery.

Conclusion: This study demonstrated that sprint and repeated sprint performances were different between white and black women. Differences in anaerobic performance between the groups were associated with racial differences in lactate levels and blood count among women’s group during recovery time. Hence, it is important to take into account this race-related difference in hematological parameters in responses to intense efforts.