加味大黄?虫颗粒对精索静脉曲张模型大鼠精子线粒体结构的影响

目的:探索加味大黄?虫颗粒对精索静脉曲张模型大鼠精子线粒体结构的影响。方法:40只雄性大鼠随机选出10只作为假手术组,剩余30按照Turner方法制造左侧精索静脉曲张模型大鼠,造模完成后,按照随机数字表法分为加味大黄?虫颗粒组、模型组、迈之灵组,每组各10只。加味大黄?虫颗粒组给予加味大黄?虫颗粒灌胃; 迈之灵组予迈之灵片,假手术组和模型组分别予等剂量0.9%生理盐水灌胃。8周后处死所有大鼠,取出左侧睾丸组织,完成精液质量分析、睾丸组织病理检测。结果:灌胃8周后,加味大黄?虫颗粒组精子浓度、总活率、前向运动精子、精子直线速度(VSL)、精子曲线速度(VCL)、平均路径速度(VAP)、精子头侧摆幅度(ALH),明显高于模型组(P<0.05)。模型组睾丸组织病理报告生精小管管腔空化,各级生精细胞破坏严重,精子膜结构破坏,精子线粒体肿胀、溶解。而加味大黄?虫颗粒组中睾丸组织的病理损伤得到不同程度的改善,精子线粒体结构完整,形态大小规则。结论:加味大黄?虫颗粒在一定程度上修复精索静脉曲张大鼠睾丸组织的病理损伤,进而起到保护精子线粒体结构与功能的作用,为精子的发育、活动提供稳定的能量代谢环境,有助提高精子活力及增加受精能力。     

彩色多普勒血流显像对椎动脉病变的分析研究

应用彩色多普勒血流显像技术测定３０例正常人３２例椎基底动脉缺血患者椎动脉的内径、峰值血流速度、每分钟血流量、压力降半时间、阻力指数及窗口指数。结果示正常人椎动脉内径左侧占优势（Ｐ〈０．０５）。患者患侧与健侧，正常人与患者患侧相比各指标均有显著性差异（Ｐ〈０．０１或０．００１）。结论：彩色多普勒血流显像对判定颅外脑血管的病理及机能状态，特别是椎基底动脉供血情况有重要价值。     

Increased fasting glucose and the prevalence of arterial stiffness: a cross-sectional study in Chinese adults

Abstract

Objective:

Previous studies have shown that diabetes increases the prevalence of arterial stiffness. However, it remains controversial whether impaired fasting glucose (IFG), a key pre-diabetes condition, is associated with increased risk of arterial stiffness. This study aimed to investigate the relationship between increased fasting plasma glucose (FPG) and the prevalence of arterial stiffness in a Chinese adult population.

Methods:

A random sample of 5039 participants aged 40 years or older (40·0% female) were enrolled in this study. Information on potential risk factors for cardiovascular disease was collected, and the presence of arterial stiffness was assessed by measuring brachial-ankle pulse wave velocity (baPWV). Participants were stratified into three groups: normal fasting glucose (NFG), IFG, and diabetes mellitus (DM). The IFG group was further stratified by quartiles based on the level of FPG into Q1, Q2, Q3, and Q4.

Results:

Fasting plasma glucose level was found to be independently and positively associated with baPWV. The adjusted odds ratios (ORs) (95% confidence interval (CI)) for arterial stiffness were 1·09 (0·80–1·48), 1·33 (0·98–1·81), 1·27 (0·93–1·73), 1·82 (1·31–2·53), and 2·15 (1·66–2·79) for those in IFG Q1, Q2, Q3, Q4, and DM groups compared with NFG group (P < 0·001), respectively, after adjusting for age, sex, and other potential confounders. Moreover, male participants and participants younger than 60 years were closely associated with the presence and severity of arterial stiffness (P < 0·001).

Conclusion:

Our study reports a previously unidentified positive association between increased FPG and the prevalence of arterial stiffness, suggesting the importance of FPG control in the prevention of arterial stiffness.     

Elevated alkaline phosphatase velocity strongly predicts overall survival and the risk of bone metastases in castrate-resistant prostate cancer

ObjectivesIn patients with a rising prostate-specific antigen (PSA) level during treatment with androgen deprivation therapy, identification of men who progress to bone metastasis and death remains problematic. Accurate risk stratification models are needed to better predict risk for bone metastasis and death among patients with castration-resistant prostate cancer (CRPC). This study evaluates whether alkaline phosphatase (AP) kinetics predicts bone metastasis and death in patients with CRPC.Methods and materialsA retrospective cohort study of 9,547 patients who underwent treatment for prostate cancer was conducted using the Center for Prostate Disease Research Multi-center National Database. From the entire cohort, 347 were found to have CRPC and, of those, 165 had 2 or more AP measurements during follow-up. To determine the AP velocity (APV), the slope of the linear regression line of all AP values was plotted over time. Rapid APV was defined as the uppermost quartile of APV values, which was found to be ≥6.3 IU/l/y. CRPC was defined as 2 consecutive rising PSA values after achieving a PSA nadir<4 ng/ml and documented testosterone values less than 50 ng/dl. The primary study outcomes included bone metastasis–free survival (BMFS) and overall survival (OS).ResultsRapid APV and PSA doubling time (PSADT) less than 10 months were strong predictors of both BMFS and OS in a multivariable analysis. Faster PSADT was a stronger predictor for BMFS (odds ratio [OR] = 12.1, P<0.0001 vs. OR = 2.7, P = 0.011), whereas rapid APV was a stronger predictor of poorer OS (OR = 5.11, P = 0.0001 vs. OR = 3.98, P = 0.0034). In those with both a rapid APV and a faster PSADT, the odds of developing bone metastasis and death exceeded 50%.ConclusionAPV is an independent predictor of OS and BMFS in patients with CRPC. APV, in conjunction with PSA-based clinical parameters, may be used to better identify patients with CRPC who are at the highest risk of metastasis and death. These findings need validation in prospective studies.     

一种检测根管冲洗效率模型的构建及应用

目的：构建红墨水检测根管内冲洗液交换效率的模型,检验其检测冲洗液交换效率的一致性和准确性,并使用此模型评估不同因素对冲洗液交换效率的影响。方法：将一个单弯树脂根管用PtoTaper预备至F2,分别使用红墨水和葡萄糖作为示踪剂,再按针头和流速分为3组进行冲洗实验,冲洗完毕后将残留液吸出测吸光度值,计算出剩余率。结果：相同条件下红墨水组剩余率与葡萄糖氧化酶法组剩余率差异无统计学意义（P＞0．05）;两种方法对剩余率的测定,组内相关系数大于0．75;红墨水的检出限小于葡萄糖氧化酶法;红墨水组中高流速组剩余率低于低流速组（P＜0．01）,平口针头组剩余率低于侧方开口针头组（P＜0．01）。结论：红墨水的检测准确性和葡萄糖氧化酶法一样,二者对于同一检测对象具有检测一致性,红墨水可准确检测的范围大于葡萄糖氧化酶法,不同针头设计和冲洗速度对冲洗液交换效率有影响。     

Frequency selectivity without resonance in a fluid waveguide

This study analyzes a waveguide consisting of two parallel fluid-filled chambers connected by a narrow slit that is spanned by two coupled elastic beams. A stiffness gradient exists in the longitudinal direction. This simple linear system, which contains no lumped mass, is shown to act as a spectral analyzer. Fluid waves traveling in the waveguide exhibit a distinct amplitude peak at a longitudinal location that varies systematically with frequency. The peaking is not based on resonance, but entirely on wave dispersion. When entering its peak region, the wave undergoes a sharp deceleration associated with a transition in which two propagation modes exchange roles. It is proposed that this mode shape swapping underlies the frequency analysis of the mammalian cochlea.In this study I explore the following question: How can a waveguide act as a spectral analyzer which spatially separates the frequency components of a wideband input? This question has been debated since Bekesy''s observation of traveling waves in the mammalian inner ear (1), the cochlea. On their way from base to apex, these fluid waves exhibit an amplitude peak at a frequency-dependent place. The peaking underlies our ability to identify and separate sounds.The most common explanation of cochlear frequency selectivity invokes local resonances coupled to the traveling wave (2). This approach requires a form of mass loading of the cochlear partition in addition to the mass loading by the surrounding fluid. The amount of mass needed in such models has been criticized for being unrealistically large given the cochlear anatomy (3). Even when sidestepping these objections, it has proved difficult to formulate models that reproduce both the amplitude and phase data of sensitive cochleae. On their way to the amplitude peak, cochlear traveling waves accumulate only 1–2 cycles (4, 5). Resonance-based models that produce sharp amplitude peaking tend to systematically overestimate the phase accumulation (6, 7). The resonance point acts as a cutoff, and a hypothetical frictionless wave would accumulate an infinite number of cycles when approaching it (8). Although damping will temper this singular behavior, too much of it also spoils the amplitude peaking.In active cochlear models (9, 10) this problem is circumvented by postulating a limited region of mechanical amplification (“negative damping”) basal to the resonance point. This creates a sufficiently sharp amplitude peak at a more basal location (safely away from the singularity), while still allowing ordinary damping to temper the phase accumulation near the resonance point (7).The present study explores an alternative approach which rejects resonance as the mechanism producing the peaking. In this scenario the peaking of traveling waves is created by a form of wave dispersion that is characterized by a steep deceleration of the energy transport. The deceleration produces a densification (focusing) of the energy that creates the peaking. This approach was motivated by neural data revealing a steep deceleration of cochlear waves near their peak (5, 11). Rather than building an elaborate biophysical model, the aim was to find the simplest possible fluid waveguide exhibiting steep deceleration and peaking.     

多普勒超声血流测量中仪器因素对速度测量影响的实验研究

目的　探讨不同彩色多普勒超声诊断仪对流速测定的可能影响 ,以及不同仪器测定流速与实际流速的差异和相关性。方法　利用体外模拟血流实验装置模拟 10种流速 ,在控制影响流速测定的主要因素的情况下 ,记录 5台不同类型的多普勒超声仪测定的流速。并使用其中 4台仪器测定 11名健康人的双侧颈总动脉收缩期峰值流速。比较多普勒测速与实际流速的相关性 ,以及不同仪器间流速测定的差异性。结果　体外模拟血流实验中多普勒测定的流速多数高于实际流速 ,但与实际流速之间有很好的相关性 (r=0 .96 4～ 0 .992 ,P<0 .0 0 0 5 )。 5台仪器的测定流速之间无显著性差异 ,但对流速大于 33.0 0 cm/s的数据进行分析可见其中 1台仪器与其他 4台仪器的测定流速两两之间存在显著性差异 (P<0 .0 5 )。进行人体颈总动脉的流速检测的 4台仪器中 ,该台仪器与其余 3台仪器的测速之间均有显著性差异 (P<0 .0 1)。结论　多普勒测量的流速与实际流速之间有很好的相关性 ,是评价血流动力学的有效手段。不同的多普勒超声仪器的流速测定可能存在一定差异 ,在评价正常或疾病情况下的血流速度时应当考虑到仪器因素 ,比较不同的研究结果应以已知测量的其他条件为前提。