不同屈光状态儿童应用盐酸环喷托酯滴眼后1 h内等效球镜度与瞳孔直径达到稳定所需时间及变化幅度的相关影响因素

目的　探讨不同屈光状态儿童应用盐酸环喷托酯（cyclopentolate hydrochloride，CH）滴眼后1 h内等效球镜度（spherical equivalent，SE）与瞳孔直径（pupil diameter，PD）达到稳定所需时间及变化幅度的相关影响因素。方法　选取2019年9月首次于天津医科大学眼科医院视光门诊就诊，拟诊断为屈光不正，需要进行睫状肌麻痹验光的患儿56例100眼。根据末次测量的SE将患儿分为3组:（1）近视组（40眼）:SE <-0.50 D；（2）正视组（29眼）:-0.50 D ≤ SE ≤ +0.50 D；（3）远视组（31眼）:SE > +0.50 D。在第一滴CH滴眼前和滴眼后1 h内，由同一名研究人员分别应用自动电脑验光仪（精度0.13 D）和红外瞳孔计（精度0.01 mm）监测SE和PD的动态变化，每5 min监测1次，共计13次。通过重复测量方差分析确定不同屈光状态组SE与PD达到稳定所需时间；通过方差分析比较不同屈光状态组SE和PD变化幅度差异；通过Pearson双变量相关分析寻找SE及PD变化幅度的相关影响因素。结果　近视组在第一滴CH滴眼30 min之后（包括30 min），SE峰值与各观察时间点SE测量值之间的差异均无统计学意义（均为P>0.05），差值均不超过0.04 D；正视组在第一滴CH滴眼30 min之后（包括30 min），SE峰值与各观察时间点SE测量值之间的差异均无统计学意义（均为P>0.05），差值均不超过0.13 D；远视组在第一滴CH滴眼35 min之后（包括35 min），SE峰值与各观察时间点SE测量值之间的差异均无统计学意义（均为P>0.05），差值均不超过0.07 D。总体上，95眼（95%）在第一滴CH滴眼后1 h内SE峰值与SE在第一滴CH滴眼后35 min时的测量值之间差异不超过0.25 D。近视组在第一滴CH滴眼后55 min内（包括55 min），PD峰值与各观察时间点PD测量值之间的差异均有统计学意义（均为P<0.05），但在55 min时差异（0.07 mm）无临床意义；正视组在第一滴CH滴眼后55 min内（包括55 min），PD峰值与各观察时间点PD测量值差异均有统计学意义（均为P<0.05），但在55 min时差异（0.05 mm）无临床意义；远视组在第一滴CH滴眼后55 min内（包括55 min），PD峰值与各观察时间点PD测量值差异均有统计学意义（均为P<0.05），但在55 min时差异（0.06 mm）无临床意义。总体上，86眼（86%）在第一滴CH滴眼后1 h内PD峰值与PD在第一滴CH滴眼后55 min时的测量值之间差异不超过0.10 mm。Pearson双变量线性相关分析显示，SE变化幅度与眼轴长度（r=-0.445，P<0.001）、年龄（r=-0.225,P=0.024）均呈显著负相关，与末次SE（r=0.543，P<0.001）、初始SE（r=0.297，P=0.003）均呈显著正相关，与性别（r=0.113，P=0.262）、眼压（r=-0.142，P=0.158）均无相关性。PD变化幅度与初始PD（r=-0.583，P<0.001）呈显著负相关，与年龄（r=-0.008，P=0.933）、性别（r=0.005，P=0.957）、眼压（r=-0.139，P=0.167）、眼轴长度（r=-0.020，P=0.843）、末次PD（r=-0.003，P=0.979）均无相关性。本研究全程未观察到严重不良反应。结论　CH用于6~15岁儿童时，SE早于PD达到稳定。睫状肌麻痹验光无需等到瞳孔充分散大，可在第一滴CH滴眼35 min后进行。CH对于年龄小和远视的儿童睫状肌麻痹作用更强，对于初始瞳孔越小的儿童瞳孔散大作用越明显。     

Renal mass dosing and graft function in children transplanted from pediatric donors

It has been suggested that ”renal mass dosing” may affect graft evolution. Between 1993 and 1999, 43 children, aged 4–17 years, received 43 pediatric cadaveric grafts. The ratio between graft volume (calculated by ultrasound within the first 24 h from transplantation, by ellipsoid formula) and the recipient’s body surface area (BSA) ranged between 14.1 and 110 ml/m². Three groups were identified: group 1, 14–29 ml/m² (13 patients); group 2, 30–39 ml/m² (16 patients); group 3, 40–110 ml/m² (14 patients). As a consequence of the different renal volume increments in the three groups during the first year after transplant, no differences in the absolute renal volume were observed at the end of follow-up. The average follow-up was 38 months (range 12–80). In the 37 routine graft biopsies, performed on average 13 months after transplantation and with more than five glomeruli, maximum mean glomerular diameters were mostly above normal values. There were no significant differences among the three groups. At the end of follow-up, the three groups did not differ in microalbuminuria, proteinuria, glomerular function or in incidence of hypertension. From this retrospective study, we conclude that the very wide range of renal mass dosing did not cause differences in medium-term graft evolution. A longer follow-up will be necessary to ascertain the possible influence of disproportion between pediatric donors and recipients, on a long-term graft outcome. Received: 27 March 2001 / Revised: 13 September 2001 / Accepted: 18 November 2001     

根管预备的直径不同对超声根管冲洗效果影响的SEM研究

[目的]观察离体牙根管预备冲洗后根管壁残存碎屑量以及牙本质小管口直径,探讨在超声根管冲洗中,根管预备的直径不同对根管冲洗效果的影响.[方法]将60颗离体牙随机分成 A1、A2、A3和B1、B2、B3六组,每组10颗牙,进行预备和冲洗.A组以注射器冲洗,B组以超声波冲洗.根管冲洗液均使用5.25% NaClO溶液.制作扫描电镜标本,评价根管壁牙本质表面残存碎屑量、测量牙本质小管口直径.[结果]①残存碎屑量A1、A2、A3三组在根管的冠1/3、中1/3、和尖1/3均有大量碎屑残存.超声冲洗组,根管壁玷污层被去除,牙本质小管口暴露.A1、A2、A3三组与 B1、B2、B3三组在根管冠1/3、中1/3、尖1/3三部位的残存碎屑量比较,差异有显著性意义(P＜0.05).B1、B2、B3三组在根管冠1/3、中1/3和尖1/3的残存碎屑量,差异无显著性意义(P＞0.05).②B1、B2、B3三组间在冠1/3、中1/3、尖1/3三部位的牙本质小管口直径,差异有显著性意义(P＜0.05);每两组间比较,差异有显著性意义(P＜0.05).[结论]使用相同剂量的NaClO溶液时,在去除根管壁牙本质表面玷污层和根管壁牙本质表面碎屑的效果上,超声根管冲洗优于人工注射器冲洗.在超声根管冲洗中,增大根管预备的直径能提高冲洗液去除玷污层的效果.超声根管冲洗以NaClO为冲洗液时,对牙本质小管口及管周牙本质没有造成过度脱矿和蚀刻.     

Light microscopic differentiation of two populations of rat olfactory bulb granule cells

Examination of glycolmethacrylate embedded olfactory bulbs of normal rats revealed that the granule cells of the accessory olfactory bulb were dissimilar from the majority of main olfactory bulb granule cells. Cells from these structures can be discriminated on the basis of spherical form, nuclear diameter, nucleoplasm staining, basal dendritic arborizations, and susceptibility to loss after neonatal X-irradiation. Based on their staining qualities, we have called these cells light and dark granule cells. In the normal rat the dark granules make up about 85% of granule cells in the main olfactory bulb and is the cell type preferentially killed by neonatal X-irradiation. Timing of postnatal X-irradiation and consequent differential loss of the dark type of main olfactory bulb granule cell suggests that the light type is largely prenatally formed.     

The effects of different patterns of muscle activity on capillary density,mechanical properties and structure of slow and fast rabbit muscles

Summary When rabbit fast muscles were chronically stimulated at a frequency naturally occurring in nerves to slow muscles (10 Hz), there was a transformation towards a slow muscle type such as an increase of capillary density, increased activity of the oxidative enzyme, succinic dehydrogenase, and a decrease of muscle fibre diameters. After 28 days the intensity and distribution of SDH and the capillary density were similar to those of soleus.The increases in capillary density preceded the changes in activity of SDH; there was a significantly greater capillary/muscle fibre ratio and number of capillaries/mm² in muscles stimulated for only 4 days at which time no change could be detected in SDH. These changes were induced by slow frequency stimulation only, and not by an overall increase of activity.Stimulation of fast muscles for 4 days at a higher frequency naturally occurring in the nerves to fast muscles (short bursts of tetani), with the same total number of stimuli as that used in slow frequency stimulation did not produce any changes in capillary density, activity of SDH or contraction times. No changes were observed in either fast or slow muscles stimulated with short bursts of tetani (and lower total number of impulses) up to 28 days.Activation of fast muscles at 5 Hz continuously or 10 Hz intermittently also caused an increase in capillary density.It is therefore concluded that only low frequency activation of fast muscles brings about a transformation of the muscle fibres towards a slow type and that the first noticeable change is an increase in the capillary density.     

Effects of Fiber Diameter on Crack Resistance of Asphalt Mixtures Reinforced by Basalt Fibers Based on Digital Image Correlation Technology

It is now more popular to use basalt fibers in the engineering programs to reinforce the crack resistance of asphalt mixtures. However, research concerning the impact of the basalt fiber diameter on the macro performance of AC-13 mixtures is very limited. Therefore, in this paper, basalt fibers with three diameters, including 7, 13 and 25 μm, were selected to research the influences of fiber diameter on the crack resistance of asphalt mixtures. Different types of crack tests, such as the low temperature trabecular bending test (LTTB), the indirect tensile asphalt cracking test (IDEAL-CT), and the semi-circular bend test (SCB), were conducted to reveal the crack resistance of AC-13 mixtures. The entire cracking process was recorded through the digital image correlation (DIC) technique, and the displacement cloud pictures, strain, average crack propagation rate (V) and fracture toughness (FT) indicators were used to evaluate the crack inhibition action of the fiber diameter on the mixture. The results showed that the incorporation of basalt fiber substantially improved the crack resistance, slowed down the increase of the displacement, and delayed the fracture time. Basalt fiber with a diameter of 7 μm presented the best enhancement capability on the crack resistance of the AC-13 mixture. The flexibility index (FI) of the SCB test showed a good correlation with V and FT values of DIC test results, respectively. These findings provide theoretical advice for the popularization and engineering application of basalt fibers in asphalt pavement.     

Fine particulate matter and body weight status among older adults in China: Impacts and pathways

BackgroundPopulation ageing and air pollution have become two major public health concerns in China. Longitudinal evidence on the body weight impacts of air pollution among older adults is rare. This study aims to investigate the impacts of ambient particulate matter with aerodynamic diameters ≤2.5 μm (PM_2.5) on weight status of older adults in China and the potential behavioral and metabolic pathways through which PM_2.5 influences weight status.MethodsThe longitudinal data from the China Health and Retirement Longitudinal Study (body mass index—BMI, n = 9053; waist/height ratio—WHR, n = 9064) were linked to the air pollution data at the city-level with a rural-urban distinction. We used mixed-effects linear models to evaluate the impacts of PM_2.5 on individual weight status and multiple mediation analysis to examine potential pathways.ResultsAfter adjusting for relevant socioeconomic and city-level risk factors, significant and robust positive impacts of PM_2.5 on BMI (0.025, 95%CI: 0.018, 0.031) and WHR*100 (0.058, 95%CI: 0.044, 0.072) were found among older adults in China. The PM_2.5-weight status relationship among older adults may be mediated through metabolic and inflammatory dysfunction pathways particularly HbA1c and C-reactive protein (CRP). As PM_2.5 deteriorates, the detrimental impacts tend to be more severe for rural-urban migrants and rural residents, compared to their urban counterparts. The worsening rural PM_2.5 profiles in some areas, such as the northern parts of the Central and the Eastern, may leave them particularly vulnerable to air pollution.ConclusionsPM_2.5 has an independent and significant detrimental impact on weight status including BMI and WHR of older adults in China, especially among rural adults and rural-urban migrants. PM_2.5 may affect weight status of older adults through biomarkers such as HbA1c and CRP. More research is needed to confirm our findings.     

不同直径腹股沟疝应用腹腔镜疝修补术治疗的临床疗效比较

目的：比较不同直径腹股沟疝应用腹腔镜疝修补术治疗的临床疗效。方法：选取自2009年2月至2013年10月收治的80例腹股沟疝患者作为研究对象,按照疝环直径大小将80例患者分为A组（疝环直径≥10cm）38例与B组（疝环直径＜10cm）42例,均给予腹腔镜疝修补术治疗,比较两组患者手术疗效。结果：两组患者手术时间及住院时间比较均无明显差异（ P＞0．05）,但A组术中出血量明显少于B组（ P＜0．05）,A组术后切口疼痛2例,B组术后切口感染1例、切口血肿1例,两组患者术后并发症发生率分别为5．26％、4．76％,组间比较无明显差异（X2＝1．027,P＝0．182）,无统计学意义。结论：大直径腹股沟疝与小直径腹股沟疝采用腹腔镜疝修补术治疗同样安全有效,且术中损伤较小,更利于手术操作。     

Acute effects of intravenously administered ethanol on retinal vessel diameters and flicker induced vasodilatation in healthy volunteers

There is evidence from several vascular beds that acute alcohol consumption causes ocular hypotension and peripheral vasodilatation. The current study investigated the effects of intravenously administered ethanol on retinal vessel diameters and on flicker induced retinal vasodilatation. For this purpose, ethanol (0.35 g/kg) or placebo (physiologic saline solution) was administered intravenously for 40 min in a randomized, double masked, two way cross-over design to 12 healthy male volunteers. Retinal vessel diameters and flicker induced vasodilatation were measured before administration of ethanol as well as 30, 50, 90 and 130 min after the start of infusion with a retinal vessel analyzer. Intraocular pressure, systemic blood pressure and blood ethanol concentration were determined at the same time points. Intravenous administration of ethanol increased blood ethanol concentration from 0.0 g/l to 0.56 ± 0.10 g/l. Ethanol reduced IOP, but did not change ocular perfusion pressure. After cessation of the infusion blood ethanol concentration started to drop reaching a blood ethanol concentration of 0.22 ± 0.06 g/l 130 min after the start of infusion. Retinal arterial diameters increased significantly after administration of ethanol by a maximum of + 4.2 ± 4.0%, whereas no change was observed in retinal veins. Neither arterial nor venous diameters were influenced by administration of placebo. Flicker stimulation induced a significant dilatation in both arterial and venous diameters. Ethanol did not change flicker responses in arteries or in retinal veins. In conclusion, intravenous administration of ethanol increases retinal arterial diameters, whereas venous diameters remained unchanged. Whether this is related to a direct vasodilator effect or to a hitherto unidentified mechanism remains to be clarified.