Rapidly cooled human sperm: no evidence of intracellular ice formation

BACKGROUND: The cellular damage that human spermatozoa encounter at rapid rates of cooling has often been attributed to the formation of intracellular ice. However, no direct evidence of intracellular ice has been presented. Alternatively, the cell damage may be the result of an osmotic imbalance encountered during thawing. This article examines whether intracellular ice forms during rapid cooling or if an alternative mechanism is present. METHODS: In this study, human spermatozoa were cooled at a range of cooling rates from 0.3 to 3000 degrees C/min. The ultrastructure of the samples was examined by cryo scanning electron microscopy and freeze substitution to determine whether intracellular ice formed during rapid cooling and to examine alternative mechanisms of cell injury during rapid cooling. RESULTS: No intracellular ice formation was detected at any cooling rate. Freeze substitution of cells that had been cooled at 3000 degrees C/min and then slowly warmed showed that the cells had become plasmolysed and had evidence of membrane damage. CONCLUSIONS: Cell damage to human spermatozoa, at cooling rates of up to 3000 degrees C/min, is not caused by intracellular ice formation. Spermatozoa that have been cooled at high rates are subjected to an osmotic shock when they are thawed.     

自冷式冰袋治疗化疗性静脉炎的观察及护理

目的观察自冷式冰袋冷敷治疗化疗药物外渗引起静脉炎的效果.方法将100例发生静脉炎的肿瘤化疗患者随机分为观察组50例和对照组50例,观察组采用自冷式冰袋冷敷患处,对照组采用普通清水冰袋冷敷患处.结果观察组治疗效果明显优于对照组.结论自冷式冰袋冷敷治疗化疗性静脉炎疗效好,在临床有较好的推广应用价值.     

关节镜术后用冰生理盐水持续冲洗在膝骨性关节炎治疗中的临床应用

目的探讨关节镜术后用冰生理盐水持续冲洗在膝骨性关节炎治疗中的疗效。方法回顾性分析我院2009年11月～2012年10月收治的178例运用关节镜术治疗膝骨性关节炎患者的临床资料。结果实验组的膝关节功能优良率、肿胀程度、自主活动度皆优于对照组（P〈0.05）。结论关节镜术后用冰生理盐水持续冲洗在膝骨性关节炎治疗过程中可取得很好的效果,值得临床推广。     

Profiles of Club Drug Users in Treatment

There is little in the literature about treatment of persons with problems with “club” or “party” drugs. This paper looks at the characteristics of individuals admitted to treatment for primary, secondary, or tertiary problems with club drugs such as ecstasy, gamma-hydroxybutyrate (GHB), ketamine, flunitrazepam (Rohypnol), methamphetamine, and hallucinogens (e.g., LSD) in programs funded by the Texas Commission on Alcohol and Drug Abuse. Some 38,350 unduplicated records from 1988 through 2003 of persons admitted with problems with club drugs were compared against users of alcohol or other drugs. Club drug users were more impaired on five of six Addiction Severity Index (ASI) indices at admission and they were more likely to use multiple substances more often. They were more likely than users of alcohol or other drugs to complete treatment, but this varied by drug. At follow-up 90 days after discharge, club drug users continued to report more ASI problems. Profiles of these clients show that ecstasy use has spread beyond the club culture, as indicated by the changes in client demographics over time. GHB clients presented a mixed picture of severe problems at admission and good response to treatment. Hallucinogen clients were young and less likely to complete treatment, while Rohypnol users were on the Texas-Mexico border. The methamphetamine epidemic has resulted in increased admissions, and the proportion of “Ice” smokers has increased. However, methamphetamine clients were less likely to complete treatment and their higher level of problems at admission and follow-up are of concern. Of special note are the indications of co-occurring problems and the need for both mental health and substance dependence treatment for some clients.     

Exopolymer alteration of physical properties of sea ice and implications for ice habitability and biogeochemistry in a warmer Arctic

The physical properties of Arctic sea ice determine its habitability. Whether ice-dwelling organisms can change those properties has rarely been addressed. Following discovery that sea ice contains an abundance of gelatinous extracellular polymeric substances (EPS), we examined the effects of algal EPS on the microstructure and salt retention of ice grown from saline solutions containing EPS from a culture of the sea-ice diatom, Melosira arctica. We also experimented with xanthan gum and with EPS from a culture of the cold-adapted bacterium Colwellia psychrerythraea strain 34H. Quantitative microscopic analyses of the artificial ice containing Melosira EPS revealed convoluted ice-pore morphologies of high fractal dimension, mimicking features found in EPS-rich coastal sea ice, whereas EPS-free (control) ice featured much simpler pore geometries. A heat-sensitive glycoprotein fraction of Melosira EPS accounted for complex pore morphologies. Although all tested forms of EPS increased bulk ice salinity (by 11-59%) above the controls, ice containing native Melosira EPS retained the most salt. EPS effects on ice and pore microstructure improve sea ice habitability, survivability, and potential for increased primary productivity, even as they may alter the persistence and biogeochemical imprint of sea ice on the surface ocean in a warming climate.     

一种石蜡切片降温组件在病理切片中的应用

目的 探讨一种石蜡切片的降温组件在病理切片中的应用价值。方法 随机选取包埋好的100个蜡块,病理科技术人员先将100个蜡块进行粗修后备用。该100个蜡块先后分别用自己制作的冰块、冷冻台及降温组件进行冷却后再切片,将切片依次编为甲组、乙组及丙组,按同一程序进行染色。以十分制评定厚薄均匀、无皱褶、无裂隙3项指标的得分,3组切片分别进行比较。并分析3组切片在切片时效性的差异(进行10次测试)以及资金投入方面的差异。结果 ①甲组与乙组比较,厚薄均匀、无皱褶、无裂隙指标得分的差异有统计学意义(P均＜0.01);甲组与丙组比较,无皱褶指标得分的差异有统计学意义(P＜0.01),厚薄均匀、无裂隙指标得分的差异均无统计学意义(P均＞0.05);乙组与丙组比较,厚薄均匀、无皱褶、无裂隙指标得分的差异均有统计学意义(P均＜0.01)。②甲组切片耗时65.30±1.44分钟,乙组切片耗时79.80±1.95分钟,丙组切片耗时62.50±2.17分钟。甲组与乙组比较,差异有统计学意义(t=5.977,P＜0.01);乙组与丙组比较,差异有统计学意义(t=5.930,P＜0.01);甲组与丙组比较,差异无统计学意义(t=1.007,P＞0.05)。③乙组6年资金投入约为7000元;6年期间甲组自己制作的冰块的成本是一台冰箱、一个不锈钢盘的成本以及盛放的水的成本大约3500元;丙组石蜡切片降温组件的成本与甲组的成本相当,比乙组的资金投入少。结论 在病理常规石蜡切片过程中,应用石蜡切片降温组件对蜡块进行冷却后进行切片,有着切片质量好、效率高、操作简便等优点,值得推荐。     

改良型冷敷带预防泪囊鼻腔吻合术后并发症的观察

目的 观察自制改良型冷敷带预防泪囊鼻腔吻合术病人术后并发症效果.方法 选择泪囊鼻腔吻合术后病人70例分为观察组33例(39眼)和对照组37例(42眼).观察组采用自制改良型冷敷带进行泪囊鼻腔吻合术后冷敷,对照组采用传统冰袋进行术后冷敷.结果 观察组术后4 h内发生出血、疼痛等并发症显著低于对照组(P<0.05);观察组塑形缺如、滑脱移位、潮湿、压迫不适等方面均明显低于对照组(P<0.05).结论 自制改良型冷敷带能有效预防泪囊鼻腔吻合术后并发症,增加病人舒适感,有效地促进了眼科术后病人快速康复.     

Brain contusion with aphasia following an ice hockey injury

Head injuries are relatively common in ice hockey, with the majority represented by concussions, a form of mild traumatic brain injury. More severe head injuries are rare since the implementation of mandatory helmet use in the 1960s. We present a case of a 27 year-old male who sustained a traumatic intraparenchymal hemorrhage with an associated subdural hematoma resulting after being struck by a puck shot at high velocity. The patient presented with expressive aphasia, with no other apparent neurologic deficits. Acutely, he was successfully treated with observation and serial neuroimaging studies ensuring an absence of hematoma expansion. After a stable clinical picture following 24 hours of observation, the patient was discharged and managed with outpatient speech therapy with full resolution of symptoms and return to play 3 months later. We will outline the patient presentation and pertinent points in the management of acute head injuries in athletes.     

Influence of sea ice on Arctic precipitation

Global climate is influenced by the Arctic hydrologic cycle, which is, in part, regulated by sea ice through its control on evaporation and precipitation. However, the quantitative link between precipitation and sea ice extent is poorly constrained. Here we present observational evidence for the response of precipitation to sea ice reduction and assess the sensitivity of the response. Changes in the proportion of moisture sourced from the Arctic with sea ice change in the Canadian Arctic and Greenland Sea regions over the past two decades are inferred from annually averaged deuterium excess (d-excess) measurements from six sites. Other influences on the Arctic hydrologic cycle, such as the strength of meridional transport, are assessed using the North Atlantic Oscillation index. We find that the independent, direct effect of sea ice on the increase of the percentage of Arctic sourced moisture (or Arctic moisture proportion, AMP) is 18.2 ± 4.6% and 10.8 ± 3.6%/100,000 km² sea ice lost for each region, respectively, corresponding to increases of 10.9 ± 2.8% and 2.7 ± 1.1%/1 °C of warming in the vapor source regions. The moisture source changes likely result in increases of precipitation and changes in energy balance, creating significant uncertainty for climate predictions.There is increasing interest in the response of the Arctic hydrologic cycle to changing climate because of its potential to influence, or feedback to, future climate change. Modeling studies have identified enhanced transport of subtropical moisture to the Arctic as well as increased Arctic evaporation as potential mechanisms of augmentation of the water cycle (1–3). The enhanced hydrologic cycle may feedback to climate change either positively or negatively; both the sign and the magnitude are yet to be determined.Observational evidence for hydrological acceleration during the past few decades is limited. Direct measurement of precipitation is difficult in the Arctic because of its cold, windy environments (4). Despite these difficulties, increasing precipitation has been reported for some Arctic locations (5, 6), and it has been hypothesized that changes in sea ice extent may have significantly influenced precipitation both in the past (7) and today (8–10). We report a study of changes in the isotopic composition of precipitation to understand the larger-scale changes of the hydrologic cycle, focusing on moisture source changes. The objective of this work is to assess observationally the effect of sea ice and the moisture transport regime on Arctic precipitation from 1990 to 2012, using the isotopic composition of precipitation from six Arctic stations. In particular, we quantify how the fraction of the total Arctic precipitation that is sourced in the Arctic responds to the sea ice extent. We then use these empirically established sensitivities of precipitation isotope ratios to sea ice change to project potential future precipitation changes and to evaluate impacts of these changes on the energy balance.Our approach is based on the premise that Arctic precipitation is composed mostly of water from two marine evaporation regions or “moisture sources”—one subtropical and one local—and that the relative contributions of the two sources to the precipitation can be determined from the stable isotopic ratios of the precipitation. We partition the two proportions, using the precipitation deuterium excess (d-excess, defined as d = δD − 8δ¹⁸O, where δD and δ¹⁸O are the parts per thousand deviation of deuterium/hydrogen and ¹⁸O/¹⁶O atomic ratios, respectively, from those of the standard mean ocean water), which is an indicator of moisture source conditions, principally the sea surface temperature (SST) and relative humidity (RH) (11–13). Moisture from subtropical regions has high d-excess values, indicative of relatively high SST and low RH at the source, whereas locally evaporated Arctic moisture has low d-excess values (14), indicating low SST and high RH. We hypothesize that precipitation d-excess is positively associated with sea ice area as a consequence of increasing local evaporation and thus increasing proportion of Arctic-sourced moisture with reduction of sea ice.We use the North Atlantic Oscillation (NAO) index as a proxy for general climate conditions to quantify effects that are independent of the sea ice influence on precipitation. Most importantly, the NAO is associated with the strength of meridional transport (15), which in turn affects precipitation d-excess by changing the proportion of subtropical moisture in the total precipitation. For example, if winds from the south strengthen, the proportion of moisture transported from the subtropics would increase, thus increasing the d-excess. In addition to meridional transport, the NAO also influences other variables, such as location of the subtropical moisture source region, temperature and humidity along the storm track, etc., all of which may affect the d-excess of precipitation. When holding the NAO constant (statistically), we also effectively remove the influences of these variables, achieving limited contamination to the signal of the direct precipitation–sea ice relationship.The six sites included in this work were from two regions, the Canadian Arctic (Alert, Eureka, and Cambridge Bay, Canada) and Greenland Sea (Reykjavìk, Iceland, Ny-Ålesend, Norway, and Danmarkshavn, Greenland) (Fig. 1). We consider all sites within a region to share similar local moisture sources. The Canadian Arctic sites receive most of their local moisture from Baffin Bay (16) and the Greenland Sea sites receive it from the Greenland Sea (17).Open in a separate windowFig. 1.Location of sites for monthly precipitation isotope ratio measurements. Shown are Canadian Arctic sites Alert, Eureka, and Cambridge Bay, Canada and Greenland Sea sites Reykjavìk, Iceland; Ny-Ålesend, Norway; and Danmarkshavn, Greenland. Local moisture sources Baffin Bay (BB) and Greenland Sea (GS) are labeled as well.