Oxygen tension and inhaled nitric oxide modulate pulmonary levels of S-nitrosocysteine and 3-nitrotyrosine in rats

The oxidative environment within the lung generated upon administration of oxygen may be a critical regulator for the efficacy of inhaled nitric oxide therapy, possibly as a consequence of changes in nitrosative and nitrative chemistry. Changes in S-nitrosocysteine and 3-nitrotyrosine adducts were therefore evaluated after exposure of rats to 80% or >95% oxygen for 24 or 48 h with and without 20 ppm inhaled nitric oxide. Exposure to 80% oxygen led to increased formation of S-nitrosocysteine and 3-nitrotyrosine adducts in lung tissue that were also associated with increased expression of iNOS. The addition of inhaled nitric oxide in 80% oxygen exposure did not alter any of these adducts in the lung or in the bronchoalveolar lavage (BAL). Exposure to >95% oxygen led to a significant decrease in S-nitrosocysteine and an increase in 3-nitrotyrosine adducts in the lung. Co-administration of inhaled nitric oxide with >95% oxygen prevented the decrease in S-nitrosocysteine levels. The levels of S-nitrosocysteine and 3-nitrotyrosine returned to baseline in a time-dependent fashion after termination of exposure to >95% oxygen and inhaled nitric oxide. These data suggest the formation of S-nitrosating and tyrosine-nitrating species is regulated by oxygen tensions and co-administration of inhaled nitric oxide restores the nitrosative chemistry without a significant impact upon the nitrative pathway.     

血液感染性安全问题的现状与展望

输血和大多数临床治疗技术一样，存在着一定的风险，输血风险主要由免疫性输血风险和输血感染性风险两大类相关的安全问题。20世纪80年代开始，由于艾滋病的发现迫使输血相关的安全问题更进一步成为公众关注的焦点。随着输血用血医学的不断发展，在已经获得很好治疗效果的同时，如何更加科学的安全用血是挑战当今公共卫生事业发展的一项大课题。     

Dynamic holographic imaging of the beating human heart

Background--Currently, the reporting and archiving of echocardiographic data suffer from the difficulty of representing heart motion on printable 2-dimensional (2D) media. Methods and Results--We studied the capability of holography to integrate motion into 2D echocardiographic prints. Images of normal human hearts and of a variety of mitral valve function abnormalities (mitral valve prolapse, systolic anterior motion of the mitral leaflets, and obstruction of the mitral valve by a myxoma) were acquired digitally on standard echocardiographic machines. Images were processed into a data format suitable for holographic printing. Angularly multiplexed holograms were then printed on a prototype holographic "laser" printer, with integration of time in vertical parallax, so that heart motion became visible when the hologram was tilted up and down. The resulting holograms displayed the anatomy with the same resolution as the original acquisition and allowed detailed study of valve motion with side-by-side comparison of normal and abnormal findings. Comparison of standard echocardiographic measurements in original echo frames and corresponding hologram views showed an excellent correlation of both methods (P<0.0001, r2=0.979, mean bias=2.76 mm). In this feasibility study, both 2D and 3D holographic images were produced. The equipment needed to view these holograms consists of only a simple point-light source. Conclusions--Holographic representation of myocardial and valve motion from echocardiographic data is feasible and allows the printing on a 2D medium of the complete heart cycle. Combined with the recent development of online holographic printing, this novel technique has the potential to improve reporting, visualization, and archiving of echocardiographic imaging.     

Intraventricular haemorrhage in the preterm infant without hyaline membrane disease

The clinicopathological associations of 33 singleton infants who died with intraventricular haemorrhage (IVH) without hyaline membrane disease (HMD) ('IVH only') were compared with those of 39 infants who died with IVH+HMD over the same gestation range in order to determine what factors other than those related to HMD may contribute to the pathogenesis of IVH. The incidence of 'IVH only' was inversely related to gestational age in the Hammersmith birth population, whereas the incidence of IVH+HMD rose to a peak at 28-29 weeks' gestation. Infants with 'IVH only' lived longer on average than those with IVH+HMD despite a lower birthweight and shorter gestation. Infants who died in the first 12 hours from 'IVH only' had suffered severe birth asphyxia but in those who died later the main symptom was recurrent apnoea. Fewer infants with asphyxia but in those who died later the main symptom was.recurrent apnoea. Fewer infants with 'IVH only' were given alkali therapy or were connected to the ventilator as compared to those with IVH+HMD, but there were no differences in alkali therapy in those who lived for 12 hours or more. In the 'IVH only' group there was a high incidence of haemorrhage from other sites and of bacterial infections. It is suggested that, in the absence of HMD, extreme immaturity is the main factor determining the occurrence of IVH. Birth asphyxia, apnoeic attacks, haemorrhage, and infections may play subsidiary roles, possibly through development of metabolic acidosis.     

Prevalence of risk factors for cardiovascular disease in Canadians 55 to 74 years of age: results from the Canadian Heart Health Surveys, 1986-1992

BACKGROUND: By 2016, the proportion of Canadians older than 65 years of age will increase to 16%, and there will be an increase in the absolute number of cases of cardiovascular disease in older Canadians. The Canadian Heart Health Surveys database provides information about this population upon which health policy related to cardiovascular disease can be based. This paper presents for the first time population-based data on the risk factors for cardiovascular disease in older Canadians. METHODS: Canadians from all 10 provinces participated in surveys of cardiovascular risk factors; health insurance registries were used as sampling frames. In each province, probability samples of 2200 adults 18 to 74 years old not living in institutions, on reserves or in military camps were asked to participate in interviews and to undergo testing at clinics for major risk factors for cardiovascular disease. RESULTS: A total of 2739 men (response rate 70%) and 2617 women (response rate 66%) aged 55 to 74 years participated in the survey and also provided follow-up clinical measurements at the clinic. Overall, 52% of participants were hypertensive, 26% had isolated systolic hypertension, and 30% had a total blood cholesterol level of 6.2 mmol/L or greater. Rates of current smoking were lower in women than men (17% v. 22%). Overall, 87% of men and 78% of women who were current smokers smoked at least 10 cigarettes per day. Only slightly more than half of participants exercised at least once a week for at least 15 minutes, and almost half had a body mass index of 27 or greater. In only 4% was no major risk factor for cardiovascular disease detected. INTERPRETATION: Significant numbers of older Canadians have one or more major risk factors for cardiovascular disease. Many of these risk factors are amenable to modification.     

超长段尿道狭窄术后勃起功能的评估

目的 探讨自体组织替代治疗超长段尿道狭窄对勃起功能的影响.方法 回顾性分析2007年1月至2009年1月采用不同自体组织补片(阴囊纵隔、包皮内板、口腔黏膜)Onlay术式替代治疗超长段男性尿道狭窄患者的临床资料,并随访患者ⅡEF-5评分、QOL评分及最大尿流率,并与术前相应情况进行分析.结果 根据研究标准收集23份有效数据.患者术前及术后3、6、12个月QOL评分分别为5.22±0.75、1.22±1.40、1.82±1.17、2.07±0.46,最大尿流率分别为(3.93±3.62)、(22.46±4.65)、(23.81±6.22)、(21.52±7.44)ml/s,术后不同时期均较术前明显改善(P＜0.01).术前及术后3、6、12个月ⅡEF-5评分分别为14.47±9.55、14.70±5.32、14.26±3.29和14.58±3.62,组间比较差异无统计学意义(P＞0.05).9例狭窄部位累及至后尿道者术后3、6、12个月ⅡEF-5评分分别为11.67±2.59、12.35±1.83、13.19±1.67,14例单纯前尿道狭窄者分别为17.79±6.42、16.57±4.78、16.01±3.85,2组间比较差异均有统计学意义(P＜0.05).狭窄累及后尿道患者多元线性回归分析中,年龄、受伤时间及尿道狭窄段长度与替代术后ⅡEF-5评分呈多元线性相关.结论 自体组织替代治疗男性超长段尿道狭窄对勃起功能影响不明显;狭窄段累及后尿道时可能对患者勃起功能产生一定影响.患者年龄和受伤时间对勃起功能有协同影响作用.

Abstract：

Objective To investigate the effect of substitutive reconstruction of long urethral stricture on male erectile function. Methods From January 2007 to January 2009, 23 patients with anterior or posterior long urethral stricture were accepted for a variety of onlay substitutive procedures, including lingual mucosa, perputial skin, and mid-scrotal skin. During the follow-up, data from the International Index of Erectile Function-5 (ⅡEF-5) questionnaire and the Quality of Life (QOL) questionnaire as well as maximal flow rate were recorded. All data were compared with those obtained before surgery. Results Significant improvement in QOL (1.22 ± 1.40, 1.82 ± 1. 17,2.07± 0.46) and maximal flow rate (22.46± 4.65, 23.81 ± 6.22, 21.52 ±7.44 ) could be observed 3, 6 and 12 months after surgery compared with those before surgery (5. 22 ± 0. 75, 3. 93 ± 3. 62)(P＜0.01). No significant differences in the responses to the ⅡEF-5 questionnaire were observed among all patients during the follow-up (P＞0. 05). At the 3, 6 and 12 months after procedure,scores of ⅡEF-5 in patients with anterior urethral stricture ( 17.79 ± 6.42, 16. 57 ± 4. 78, 16.01 ±3.85) were significantly higher than those with posterior urethral stricture (11.67 ± 2.59, 12.35 ±1.83,13. 19±1.67, P＜0.05). In patients with posterior urethral stricture, the multiple linear regression showed that age, time interval of injury and length of stricture were related to the ⅡEF-5score (P＜0.05). Conclusions Substitutive reconstruction for treating the long urethral stricture has little effect on male erectile function. But the location of stricture, especially extended to posterior urethra, may have impact on the erectile function.     

Using an instrumental variable to test for unmeasured confounding

An important concern in an observational study is whether or not there is unmeasured confounding, that is, unmeasured ways in which the treatment and control groups differ before treatment, which affect the outcome. We develop a test of whether there is unmeasured confounding when an instrumental variable (IV) is available. An IV is a variable that is independent of the unmeasured confounding and encourages a subject to take one treatment level versus another, while having no effect on the outcome beyond its encouragement of a certain treatment level. We show what types of unmeasured confounding can be tested for with an IV and develop a test for this type of unmeasured confounding that has correct type I error rate. We show that the widely used Durbin–Wu–Hausman test can have inflated type I error rates when there is treatment effect heterogeneity. Additionally, we show that our test provides more insight into the nature of the unmeasured confounding than the Durbin–Wu–Hausman test. We apply our test to an observational study of the effect of a premature infant being delivered in a high‐level neonatal intensive care unit (one with mechanical assisted ventilation and high volume) versus a lower level unit, using the excess travel time a mother lives from the nearest high‐level unit to the nearest lower‐level unit as an IV. Copyright © 2014 John Wiley & Sons, Ltd.