• 【非侵入性连续估计人pa骨的血流变化。】 复制标题 收藏 收藏
    DOI:10.1007/s11517-006-0070-0 复制DOI
    作者列表:Näslund J,Pettersson J,Lundeberg T,Linnarsson D,Lindberg LG
    BACKGROUND & AIMS: :A photoplethysmographic (PPG) technique to assess blood flow in bone tissue has been developed and tested. The signal detected by the PPG consists of a constant-level (DC) component-which is related to the relative vascularization of the tissue-and a pulsatile (AC) component-which is synchronous with the pumping action of the heart. The PPG probe was applied on the skin over the patella. The probe uses near-infrared (804 nm) and green (560 nm) light sources and the AC component of the PPG signals of the two wavelengths was used to monitor pulsatile blood flow in the patellar bone and the overlying skin, respectively. Twenty healthy subjects were studied and arterial occlusion resulted in elimination of PPG signals at both wavelengths, whereas occlusion of skin blood flow by local surface pressure eliminated only the PPG signal at 560 nm. In a parallel study on a physical model with a rigid tube we showed that the AC component of the PPG signal originates from pulsations of blood flow in a rigid structure and not necessarily from volume pulsations. We conclude that pulsatile blood flow in the patellar bone can be assessed with the present PPG technique.
    背景与目标: :已经开发并测试了用于评​​估骨组织中血流的光电容积描记(PPG)技术。 PPG检测到的信号由与组织的相对血管形成有关的恒定水平(DC)分量和与心脏的泵浦动作同步的脉动(AC)分量组成。将PPG探针施加到over骨上的皮肤上。该探头使用近红外(804 nm)和绿色(560 nm)光源,并且使用两种波长的PPG信号的AC分量分别监视monitor骨和周围皮肤中的脉动血流。对二十名健康受试者进行了研究,动脉阻塞导致两种波长的PPG信号均被消除,而局部表面压力阻塞皮肤血流仅消除了560 nm处的PPG信号。在具有刚性管的物理模型的并行研究中,我们显示了PPG信号的AC分量源自刚性结构中的血流脉动,而不一定源自体积脉动。我们得出的结论是,可以使用当前的PPG技术评估the骨中的搏动性血流。
  • 【在成年的山毛榉树下,长期熏蒸成双倍的环境臭氧浓度,其外生菌根真菌群落的变化和细根数的增加。】 复制标题 收藏 收藏
    DOI:10.1055/s-2006-924489 复制DOI
    作者列表:Grebenc T,Kraigher H
    BACKGROUND & AIMS: :Forest soils are an important but under-studied part of forest ecosystems. The effects of O(3) on below-ground processes in a mature forest have only received limited attention so far. In our study, we have analysed the community of ectomycorrhizal fungi and beech fine root dynamics over two growing seasons (2003 - 2004) in a 70-year old mixed spruce-beech forest stand, in which two groups of five adult beech trees were either fumigated by 2 x ambient ozone concentration or used as control. The main difference between previous studies and our approach was that previous studies were performed on seedlings in pot experiments or in closed or open top chambers, and not IN SITU, in a mature forest stand. Although beech is a relatively unresponsive species to tropospheric O(3), we found a pronounced effect of 2 x O(3) on the number of vital ectomycorrhizal root tips and non-turgescent fine roots. Both categories of roots were significantly increased when compared to controls in two consecutive years at each sampling event. The number of types of ectomycorrhizae and species richness increased in 2004, but not in the extremely dry year 2003. We hypothesised that the observed changes might be an expression of a transitional state in below-ground succession of niches caused by an O(3) induced effect on carbon allocation to roots and the rhizosphere. We have detected changes in ectomycorrhizal species level, however Shannon-Weavers species diversity index and percentage of types of ectomycorrhizae did not change significantly in any sampling year thus indicating our results cannot be unequivocally explained by summer drought in year 2003 or by O(3) exposure alone.
    背景与目标: 森林土壤是森林生态系统中重要但未被充分研究的部分。迄今为止,O(3)对成熟森林地下过程的影响仅受到有限的关注。在我们的研究中,我们分析了一个70年历史的云杉-山毛榉林分两个生长季节(2003年至2004年)的外生菌根真菌和山毛榉细根动态,其中两组分别是五棵成年的山毛榉木用2倍的环境臭氧浓度熏蒸或用作对照。以前的研究与我们的方法之间的主要区别是,以前的研究是在盆栽实验中或在密闭或敞开的顶室中对幼苗进行的,而不是在成熟林分中的IN SITU中进行的。尽管山毛榉对对流层O(3)的响应相对较弱,但我们发现2 x O(3)对活着的外生菌根根尖和非浑浊的细根的数量有明显的影响。与每个采样事件连续两年的对照相比,这两种类别的根均显着增加。 2004年外生菌根类型的种类和物种丰富度有所增加,但在极度干旱的2003年却没有。我们假设观察到的变化可能是由O(3)引起的地下生态位过渡状态的一种表达。诱导对根和根际碳分配的影响。我们已经检测到外生菌根物种水平的变化,但是香农-韦弗物种多样性指数和外生菌根类型的百分比在任何采样年中都没有显着变化,因此表明我们的结果不能被2003年夏季干旱或O(3)明确解释。独自暴露。
  • 【患有肺囊性纤维化的患者,在呼气压力为正值且振荡的呼气压力为正值的情况下,进行胸部物理治疗时,血气压力立即变化。】 复制标题 收藏 收藏
    DOI: 复制DOI
    作者列表:Lagerkvist AL,Sten GM,Redfors SB,Lindblad AG,Hjalmarson O
    BACKGROUND & AIMS: OBJECTIVE:To assess and compare immediate effects of chest physiotherapy with positive expiratory pressure (PEP) versus oscillating PEP on transcutaneously measured blood-gas tensions in patients with cystic fibrosis. METHODS:Fifteen patients (mean age 12.5 y, range 6.9-21.5 y) participated. The treatments were randomized and performed on 2 separate occasions, 8 weeks apart. Spirometry was conducted before and after each treatment. We transcutaneously measured oxygen tension (P(tO2). RESULTS:There were no changes in spirometry values. During PEP, different trends in blood-gas tension were seen, and there were no consistent changes. During oscillating PEP, P(tO2) increased and P(tCO2) decreased. During oscillating PEP, P(tCO2) was lower and the intra-individual change in P(tCO2) was more pronounced than during PEP. The results obtained immediately after oscillating PEP showed a higher P(tO2) and a lower P(tCO2) than with PEP. CONCLUSION:PEP and oscillating PEP can both cause transitory effects on blood gases in patients with cystic fibrosis. However, oscillating PEP alters blood-gas tensions more than does PEP, and hyperventilation during oscillating PEP may reduce treatment time.
    背景与目标: 目的:评估和比较采用呼气正压(PEP)和振荡PEP进行胸部物理治疗对囊性纤维化患者经皮测量的血气张力的即时效果。
    方法:15例患者(平均年龄12.5岁,范围6.9-21.5岁)参加了研究。治疗是随机的,分别在两个不同的场合进行,相隔8周。在每次治疗之前和之后进行肺活量测定。我们经皮测量了氧气张力(P(tO2)。
    结果:肺活量测定值没有变化。在PEP期间,观察到了血气紧张的不同趋势,并且没有一致的变化。在振荡PEP期间,P(tO2)增加而P(tCO2)减少。在振荡PEP期间,P(tCO2)较低,并且P(tCO2)的内部个体变化比PEP期间更为明显。振荡PEP后立即获得的结果显示,与PEP相比,P(tO2)更高,P(tCO2)更低。
    结论:PEP和振荡PEP均可对囊性纤维化患者的血气产生短暂影响。但是,与PEP相比,振荡PEP对血气压力的改变更大,并且在振荡PEP期间过度换气可能会减少治疗时间。
  • 【苯巴比妥依赖和戒断大鼠脑中谷氨酸受体,c-fos mRNA表达和激活蛋白-1(AP-1)DNA结合活性的变化。】 复制标题 收藏 收藏
    DOI:10.1016/s0006-8993(97)00134-0 复制DOI
    作者列表:Tanaka S,Kiuchi Y,Numazawa S,Oguchi K,Yoshida T,Kuroiwa Y
    BACKGROUND & AIMS: We studied changes in glutamate receptors, expression of immediate early genes, and AP-1 DNA binding activity in the brains of phenobarbital (PB)-dependent and -withdrawn rats to investigate the possible involvement of activation of glutamate receptors in PB withdrawal syndrome. PB-dependent rats were prepared by feeding drug-admixed food for 5 weeks. Autoradiographic analysis showed that binding of [3H(+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imin e (MK-801), an antagonist of N-methyl-D-aspartic acid (NMDA) receptors, increased significantly in the cerebral cortices of PB-dependent and 24-h-withdrawn rats. However, [3H]MK-801 binding in the hippocampus and [3H]6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) and [3H]kainic acid binding in the hippocampus and cerebral cortex were essentially unchanged in both groups. PB withdrawal seizures were followed by increased expression of c-fos mRNA in the hippocampus and cerebral cortex and of c-jun mRNA in the cerebral cortex. The induction of c-fos and c-jun mRNA was suppressed by administration of MK-801. Furthermore, PB withdrawal enhanced AP-1 DNA binding activity in the brain. The present findings suggest functional enhancement of glutamatergic neurotransmission during the development of PB withdrawal syndrome.

    背景与目标: 我们研究了苯巴比妥(PB)依赖和戒断大鼠大脑中谷氨酸受体的变化,立即早期基因的表达以及AP-1 DNA结合活性,以研究PB戒断综合征中谷氨酸受体活化的可能。通过喂食药物混合的食物5周来制备PB依赖的大鼠。放射自显影分析表明,结合物[3H()-5-甲基-10,11-二氢-5H-二苯并[a,d]环庚烯-5,10-亚胺e(MK-801)是一种N-甲基-拮抗剂D-天冬氨酸(NMDA)受体,在PB依赖和24小时戒断大鼠的大脑皮层中显着增加。然而,在海马中的[3H] MK-801结合以及在海马和大脑皮层中的[3H] 6-氰基-7-硝基喹喔啉-2,3-二酮(CNQX)和[3H]海藻酸结合基本上没有变化。组。 PB抽搐发作后,海马和大脑皮层中c-fos mRNA的表达增加,大脑皮层中c-jun mRNA的表达增加。通过施用MK-801抑制了c-fos和c-jun mRNA的诱导。此外,PB撤离可增强大脑中AP-1 DNA的结合活性。目前的发现表明,在PB戒断综合征的发展过程中,谷氨酸能神经传递的功能增强。

  • 【即将进入二十世纪的职业医学:对预防方法中已完成和预期发生的变化的评估。】 复制标题 收藏 收藏
    DOI: 复制DOI
    作者列表:Indulski JA
    BACKGROUND & AIMS: The World Bank in its document under the title 'Investing in Health' (1993) states that the health status of the population, including the working population, and working conditions in individual countries depend essentially on the value of gross national product per capita. The attitudes towards the role and objectives of occupational medicine have changed significantly over the last three decades. A high priority given to primary prevention reflects the mainstream of a new approach to preventive measures. Advancements in technology, production and services, common use of computers and flattening of work organisation structures have brought about the need for workers' active participation in planning of activities and shaping working conditions in own enterprise. At the same time, workers are required to possess much higher qualifications facilitating their participation in applying new technologies and using new information systems, which resulted in a fierce competition on the labour market. In the countries in the political, social and economic transition, the conditions for introducing a new system of sustained development, described by Gustavsen at the 25th International Congress on Occupational Health have not as yet been established. A procedure-based system involving negotiations between employers and workers' representatives failed to be successful in improving working conditions as the roles of the state, employers and trade unions had not been defined precisely. It is expected that further health promotion at the worksites in these countries will depend mainly on the economic progress and the reformed system of education.

    背景与目标: 世界银行在其题为“投资卫生”(1993年)的文件中指出,人口的健康状况,包括劳动人口,以及各个国家的劳动条件,基本上取决于人均国民生产总值。在过去的三十年中,人们对职业医学的作用和目标的态度发生了巨大变化。对初级预防的高度重视反映了预防措施新方法的主流。技术,生产和服务的进步,计算机的普遍使用以及工作组织结构的扁平化带来了工人积极参与活动计划和塑造本企业工作条件的需求。同时,要求工人具有更高的资格,以促进他们参与应用新技术和使用新信息系统,从而导致劳动力市场上的激烈竞争。在政治,社会和经济转型国家中,古斯塔夫森在第25届国际职业卫生大会上描述的引入新的可持续发展系统的条件尚未建立。涉及雇主和工人代表之间的谈判的基于程序的系统未能成功改善工作条件,因为国家,雇主和工会的角色尚未得到准确界定。预计这些国家在工作场所进一步促进健康将主要取决于经济进步和教育体制的改革。

  • 【表型转换导致平滑肌肌膜结构和功能的变化。】 复制标题 收藏 收藏
    DOI:10.1016/j.yexcr.2006.07.012 复制DOI
    作者列表:Matschke K,Babiychuk EB,Monastyrskaya K,Draeger A
    BACKGROUND & AIMS: :Continuous changes in the length of smooth muscles require a highly organized sarcolemmal structure. Yet, smooth muscle cells also adapt rapidly to altered environmental cues. Their sarcolemmal plasticity must lead to profound changes which affect transmembrane signal transduction as well as contractility. We have established porcine vascular and human visceral smooth muscle cultures of epithelioid and spindle-shaped morphology and determined their plasma membrane properties. Epithelioid cells from both sources contain a higher ratio of cholesterol to glycerophospholipids, and express a less diverse range of lipid-associated annexins. These findings point to a reduction in efficiency of membrane segregation in epithelioid cells. Moreover, compared to spindle-shaped cells, cholesterol is more readily extracted from epithelioid cells with methyl-beta-cyclodextrin and its synthesis is more susceptible to inhibition with lovastatin. The inability of epithelioid cells to process vasoactive metabolites, such as angiotensin or nucleotides further indicates that contractile properties are impaired. Phenotypic plasticity extends beyond the loss of smooth muscle cell marker genes. The plasma membrane has undergone profound functional changes which are incompatible with cyclic foreshortening, but might be important in the development of vascular disease.
    背景与目标: :平滑肌长度的连续变化需要高度组织化的肌膜结构。然而,平滑肌细胞也能迅速适应变化的环境提示。它们的肌膜可塑性必须导致深刻的变化,从而影响跨膜信号转导和收缩。我们已经建立了上皮样和纺锤形形态的猪血管和人内脏平滑肌培养物,并确定了它们的质膜特性。来自两种来源的上皮样细胞都含有较高的胆固醇与甘油磷脂比例,并且表达的脂质相关膜联蛋白的变化范围较小。这些发现表明上皮样细胞中膜分离的效率降低。而且,与纺锤形细胞相比,胆固醇更容易用甲基-β-环糊精从上皮样细胞中提取,并且其合成更容易受到洛伐他汀的抑制。上皮样细胞不能处理血管活性代谢产物,例如血管紧张素或核苷酸,这进一步表明收缩特性受到损害。表型可塑性超出了平滑肌细胞标记基因丧失的范围。质膜已经发生了深刻的功能变化,这与循环缩短不相容,但是在血管疾病的发展中可能很重要。
  • 【E-选择素的代谢变化是由携带唾液酸化的刘易斯A抗原的粘蛋白结合引起的。】 复制标题 收藏 收藏
    DOI:10.1006/bbrc.1997.6683 复制DOI
    作者列表:Nakada H,Inoue M,Yamashina I
    BACKGROUND & AIMS: Mucin-type glycoproteins carrying sialylLeA antigens (SL-GP) were isolated from the ascites fluid of a patient with colorectal cancer. SL-GP bound to E-selectin on endothelial cells in Ca2+- and sialylLeA antigen-dependent manners. To examine the metabolic change in E-selectin caused by ligation, endothelial cells were labeled with 32P-phosphate or 35S-Met and 35S-Cys. Phosphorylation at one or more serine residues of E-selectin was elevated by ligation with SL-GP but not with sialylLeA hexasaccharide. Pulse-labeling of E-selectin with 35S-Met and 35S-Cys in the presence of SL-GP indicated that the degradation of E-selectin was accelerated by SL-GP ligation, but labeling after pre-ligation with SL-GP revealed an increase in the synthesis of E-selectin. The synthesis may reflect compensation for the E-selectin degraded on pre-ligation. These results indicate that the overall metabolism of E-selectin was enhanced by the ligation of SL-GP, with degradation and synthesis being apparently balanced.

    背景与目标: 从患有结肠直肠癌的患者的腹水中分离出带有唾液酸LeA抗原的粘蛋白型糖蛋白(SL-GP)。 SL-GP以Ca2-和sialylLeA抗原依赖性方式与内皮细胞上的E-选择素结合。为了检查由连接引起的E-选择素的代谢变化,用32P-磷酸或35S-Met和35S-Cys标记内皮细胞。通过与SL-GP而非唾液酸LeA六糖连接,可增强E-选择蛋白一个或多个丝氨酸残基的磷酸化作用。在SL-GP存在下用35S-Met和35S-Cys脉冲标记E-选择素表明SL-GP连接可加速E-选择素的降解,但SL-GP预连接后的标记显示E-选择素的降解E-选择素的合成增加。该合成可以反映对在预连接时降解的E-选择蛋白的补偿。这些结果表明SL-GP的连接增强了E-选择素的整体代谢,降解和合成明显平衡。

  • 【慢性伤口愈合过程中趋化因子和炎性细胞因子的变化。】 复制标题 收藏 收藏
    DOI:10.1046/j.1524-475X.1997.50405.x 复制DOI
    作者列表:Fivenson DP,Faria DT,Nickoloff BJ,Poverini PJ,Kunkel S,Burdick M,Strieter RM
    BACKGROUND & AIMS: :Wound healing is a complex process resulting from an interplay of processes including coagulation, inflammation, angiogenesis, and epithelialization. The chemokine family has been shown to contain members that are potent regulators of many of these pathways. Because we have previously shown that chemokines "pool" in biologic wound dressings, we studied the levels of CXC and CC chemokines, along with key inflammatory mediators, serially from a group of patients undergoing therapy for chronic venous leg ulcers. After 8 weeks, all patients had marked clinical healing of their ulcers (median 63.3% reduction in size) with two of 10 completely healed. Wound fluids extracted from dressings showed high levels of platelet factor-4 and interferon-gamma-inducible protein, with a trend toward increases in the ratio of the sums of the angiogenic versus angiostatic CXC chemokines (p = 0.082) in the tissues collected from the center of the ulcers during wound closure. Neutrophil-activating peptide-2 and interleukin-8 accounted for the most changes in wound fluid angiogenic chemokines, with significant differences both as compared with baseline levels and with patients' plasma level noted at various time points between weeks 0 and 8. The level of angiostatic chemokines, interferon-y inducible protein 10 and platelet-activating-4, fell most significantly between weeks 0 and 3 as compared with plasma levels. The observed shift toward angiogenic CXC chemokines suggests that effective healing in chronic venous insufficiency ulcers appears to "move" the ulcer bed toward a state more conducive to epithelialization,characteristic of the proliferative phase of wound healing. CC chemokines were also elevated at baseline in the wound fluid samples as compared with the patients' plasma levels. Macrophage inflammatory protein-1 (3 and regulated on activation, normal T expressed and secreted (RANTES) levels decreased with healing, whereas there were significant increases in the tissue levels of monocyte chemoattractant protein-1 and macrophage inflammatory protein-1 a over the first 4 weeks of therapy (p< or = 0.05 for both). Coincident with these changes was a steady increase in the ratio of interleukin-1 R/interleukin-1 receptor antagonist protein in the ulcer center tissues, which also correlated with healing (p < 0 .05) as compared with a decreasing ratio at the ulcer edge, and a biphasic response in the wound fluids. These findings suggest that advanced wound care techniques help move the ulcer from a chronic inflammatory state into one more characteristic of the late inflammatory/early proliferative phase of wound healing. Chemokines may play a critical role in the pathogenesis of chronic venous ulcers through their effects on angiogenesis and/or the progression of inflammatory reactions at the site of injury.
    背景与目标: :伤口愈合是一个复杂的过程,是由凝血,炎症,血管生成和上皮形成等过程相互影响而产生的。趋化因子家族已显示其成员是这些途径中许多的有效调节因子。因为我们先前已经证明趋化因子在生物伤口敷料中“聚集”,所以我们从一组接受慢性静脉腿溃疡治疗的患者中连续研究了CXC和CC趋化因子以及关键的炎症介质的水平。 8周后,所有患者的溃疡均得到了明显的临床治愈(中位数减少了63.3%),其中10例中的2例完全治愈。从敷料中提取的伤口液显示出高水平的血小板因子4和干扰素-γ诱导型蛋白,并且在从组织中收集的组织中,血管生成与血管抑制性CXC趋化因子之和的比例有增加的趋势(p = 0.082)。伤口闭合过程中溃疡的中心。中性粒细胞激活肽2和白细胞介素8引起伤口液中血管生成趋化因子的变化最多,与基线水平相比以及在0至8周的各个时间点记录的患者血浆水平均存在显着差异。与血浆水平相比,血管静息趋化因子,γ-干扰素诱导蛋白10和血小板活化因子4在第0周和第3周之间下降最为明显。观察到的向血管生成性CXC趋化因子的转变表明,慢性静脉功能不全溃疡的有效愈合似乎将溃疡床“移”至更有利于上皮化的状态,这是伤口愈合增殖阶段的特征。与患者血浆水平相比,伤口液样本中的CC趋化因子在基线时也升高。巨噬细胞炎性蛋白-1(3和活化受调节,正常T表达和分泌(RANTES)水平随愈合而降低,而单核细胞趋化蛋白-1和巨噬细胞炎性蛋白1a的组织水平在第一时间显着增加治疗4周(二者均p≤0.05)。溃疡中心组织中白细胞介素1 R /白细胞介素1受体拮抗剂蛋白的比例稳定增加,这与这些变化相关,也与愈合相关(p <0 .05),而溃疡边缘的比率降低,伤口液出现双相反应,这些发现表明,先进的伤口护理技术有助于将溃疡从慢性发炎状态转变为晚期发炎的另一特征/伤口愈合的早期增殖阶段。趋化因子可能通过影响血管生成和/或炎症的发展而在慢性静脉溃疡的发病过程中发挥关键作用受伤部位的反应性反应。
  • 【再生大鼠肝脏线粒体H -ATPase活性和F1含量的变化。】 复制标题 收藏 收藏
    DOI:10.1016/0014-5793(85)80400-2 复制DOI
    作者列表:Buckle M,Guerrieri F,Papa S
    BACKGROUND & AIMS: :Submitochondrial particles prepared from rat liver during hepatic regeneration exhibit a depressed ATPase activity which is correlated with a decrease in F1 subunit content as shown by SDS-PAGE. Use of an antibody directed against the F1 portion of the H+-ATPase complex demonstrated that there is a definite decrease in the amount of beta-subunit of F1 in both submitochondrial particles and mitochondria from rat liver 24 h after partial hepatectomy.
    背景与目标: 肝再生过程中,从大鼠肝脏制备的线粒体颗粒显示出较低的ATPase活性,这与FDS亚基含量的降低有关,如SDS-PAGE所示。使用针对H -ATPase复合物的F1部分的抗体证明,部分肝切除术后24小时,来自大鼠肝脏的线粒体颗粒和线粒体中F1的β亚基的含量明显减少。
  • 【腰椎骨矿物质密度分布的纵向变化可能会增加楔形骨折的风险。】 复制标题 收藏 收藏
    DOI:10.1016/j.clinbiomech.2012.10.005 复制DOI
    作者列表:Giambini H,Khosla S,Nassr A,Zhao C,An KN
    BACKGROUND & AIMS: BACKGROUND:Trabecular bone strength diminishes as a result of osteoporosis and altered biomechanical loading at the vertebral and spinal levels. The spine consists of the anterior, middle and posterior columns and the load supported by the anterior and middle columns will differ across different regions of the spine. Stress shielding of the anterior column can contribute to bone loss and increase the risk of wedge fracture. There is a lack of quantitative data related to regional spinal bone mineral density distribution over time. We hypothesize that there is an increase in the posterior-to-anterior vertebral body bone mineral density ratio and a decrease in whole-body bone mineral density over time. METHODS:Bone mineral density was measured in 33 subjects using quantitative computed tomography scans for L1-L3 vertebrae, region (anterior and posterior vertebral body), and time (baseline and 6 years after). FINDINGS:Lumbar bone mineral density decreased significantly (Δ: ~15%) from baseline to the 6th year visit. Individual vertebra differences over time (L1: ~14%, L2: ~14%, L3: ~17%) showed statistical significance. Anterior bone mineral density change was significantly greater than in the posterior vertebral body region (Δ anterior: ~18%; Δ posterior: ~13%). Posterior-to-anterior bone mineral density ratio was significantly greater in the 6th year compared to baseline values (mean (SD), 1.33 (0.2) vs. 1.23 (0.1)). INTERPRETATION:This study provides longitudinal quantitative measurement of bone mineral density in vertebrae as well as regional changes in the anterior and posterior regions. Understanding bone mineral density distribution over time may help to decrease the risk of wedge fractures if interventions can be developed to bring spine loading to its normal state.
    背景与目标: 背景:由于骨质疏松症以及椎体和脊柱水平的生物力学负荷改变,小梁的骨强度降低。脊柱由前,中和后柱组成,由前柱和中柱支撑的载荷在脊柱的不同区域会有所不同。前柱的应力屏蔽可能会导致骨质流失并增加楔形骨折的风险。缺乏与区域脊柱骨矿物质密度随时间分布有关的定量数据。我们假设随着时间的推移,椎体前后骨矿物质密度比增加,而全身骨矿物质密度降低。
    方法:采用定量计算机断层扫描技术对33名受试者的L1-L3椎骨,区域(椎体的前后)和时间(基线及术后6年)进行了骨矿物质密度测量。
    结果:从基线到第6年随访,腰椎骨矿物质密度显着降低(Δ:〜15%)。随时间变化的各个椎骨差异(L1:〜14%,L2:〜14%,L3:〜17%)显示出统计学意义。前骨矿物质密度变化显着大于后椎体区域(Δ前:〜18%;Δ后:〜13%)。与基线值相比,第6年的前后骨矿物质密度比显着更高(平均值(SD)为1.33(0.2)对1.23(0.1))。
    解释:这项研究提供了纵向定量测量椎骨中骨矿物质密度以及前后区域的变化的信息。如果可以采取干预措施使脊柱负荷恢复到正常状态,那么了解随着时间推移的骨矿物质密度分布可能有助于降低楔形骨折的风险。
  • 【痴呆症磁共振成像中的认知和白质变化。】 复制标题 收藏 收藏
    DOI:10.1001/archneur.1990.00530040029015 复制DOI
    作者列表:Kertesz A,Polk M,Carr T
    BACKGROUND & AIMS: :In a prospective magnetic resonance imaging and cognitive study of 38 demented patients and 15 control subjects, 11 of 27 patients with Alzheimer's disease and 8 of 11 patients with vascular dementia had significant periventricular hyperintensities. Memory and language testing in the early investigation of dementia is useful to distinguish patients with or without periventricular hyperintensities on magnetic resonance imaging. Patients without periventricular hyperintensities are worse on memory and conceptualization tests than patients with periventricular hyperintensities, who tend to be worse on comprehension and attention tests. These differences in cognitive pattern are present between patients with different pathogenesis who are otherwise matched for dementia severity. Language and some nonverbal cognitive deficits correlate with the extent of cortical and ventricular atrophy in Alzheimer's disease.
    背景与目标: :在一项针对38名痴呆患者和15名对照受试者的前瞻性磁共振成像和认知研究中,27名阿尔茨海默氏病患者中的11名和11名血管性痴呆患者中的8名出现了明显的脑室高信号。痴呆症早期调查中的记忆和语言测试有助于区分磁共振成像中是否伴有脑室高信号的患者。没有脑室高信号的患者在记忆力和概念化测试方面比脑室高信号的患者在理解和注意力测试方面更差。这些认知模式上的差异存在于具有不同发病机制的患者之间,这些患者在其他方面因痴呆症的严重程度而匹配。语言和一些非语言认知缺陷与阿尔茨海默氏病的皮质和心室萎缩程度有关。
  • 【胆囊体积的改变不会影响胆囊管阻力。】 复制标题 收藏 收藏
    DOI:10.1001/archsurg.1990.01410160046010 复制DOI
    作者列表:Sharp KW,Ross CB,Tillman VN,Williams LF Jr
    BACKGROUND & AIMS: :To our knowledge, the relationship between gallbladder volume and cystic duct function has not been studied. We hypothesized that changes in gallbladder volume would influence cystic duct resistance. The effect of gallbladder volume changes on cystic duct resistance to both prograde (emptying) and retrograde (filling) steady-state flow was tested in 12 dogs under basal cholecystokinin-stimulated conditions utilizing a multiport catheter with a highly compliant balloon placed within the gallbladder fundus. Gallbladder volume was regulated by varying balloon volume from empty to just beyond physiologic distention. Cystic duct resistance was not affected by balloon volume under basal or stimulated conditions or by the direction of perfusate flow. This study demonstrated no relationship between gallbladder volume and cystic duct resistance and did not demonstrate a cystic duct sphincter mechanism at physiologic gallbladder volumes.
    背景与目标: :据我们所知,尚未研究胆囊体积与胆囊管功能之间的关系。我们假设胆囊体积的变化会影响胆囊管阻力。胆囊体积变化对胆囊管抵抗顺行(空)和逆行(充盈)稳态血流的影响在12条经基础胆囊收缩素刺激的狗中使用多端口导管,并在胆囊内放置高度顺应性球囊进行了测试。胆囊体积的调节是通过将气囊体积从空变到生理上的变化来进行的。囊性导管阻力不受基础或刺激条件下的球囊容积或灌注液流向的影响。这项研究表明胆囊体积和胆囊管阻力之间没有关系,并且在生理胆囊体积上也没有证明胆囊括约肌的机制。
  • 【猪心肌梗死模型中心室去极化和复极化变化的特征。】 复制标题 收藏 收藏
    DOI:10.1088/0967-3334/33/12/1975 复制DOI
    作者列表:Romero D,Ringborn M,Demidova M,Koul S,Laguna P,Platonov PG,Pueyo E
    BACKGROUND & AIMS: :In this study, several electrocardiogram (ECG)-derived indices corresponding to both ventricular depolarization and repolarization were evaluated during acute myocardial ischemia in an experimental model of myocardial infarction produced by 40 min coronary balloon inflation in 13 pigs. Significant changes were rapidly observed from minute 4 after the start of coronary occlusion, achieving their maximum values between 11 and 22 min for depolarization and between 9 and 12 min for repolarization indices, respectively. Subsequently, these maximum changes started to decrease during the latter part of the occlusion. Depolarization changes associated with the second half of the QRS complex showed a significant but inverse correlation with the myocardium at risk (MaR) estimated by scintigraphic images. The correlation between MaR and changes of the downward slope of the QRS complex, [Formula: see text], evaluated at the two more relevant peaks observed during the occlusion, was r = -0.75, p < 0.01 and r = -0.79, p < 0.01 for the positive and negative deflections observed in [Formula: see text], temporal evolution, respectively. Repolarization changes, analyzed by evaluation of ST segment elevation at the main observed positive peak, also showed negative, however non-significant correlation with MaR: r = -0.34, p = 0.28. Our results suggest that changes evaluated in the latter part of the depolarization, such as those described by [Formula: see text], which are influenced by R-wave amplitude, QRS width and ST level variations simultaneously, correlate better with the amount of ischemia than other indices evaluated in the earlier part of depolarization or during the ST segment.
    背景与目标: :在这项研究中,在急性心肌缺血期间,在13只猪的40分钟冠状动脉球囊扩张产生的心肌梗塞实验模型中,评估了与心室去极化和复极化同时对应的几个心电图(ECG)衍生指标。从开始进行冠状动脉闭塞后的第4分钟开始迅速观察到显着变化,分别在去极化的11至22分钟和重新极化的9至12分钟之间达到最大值。随后,在咬合的后期,这些最大变化开始减少。与QRS波复杂度的后半部分相关的去极化变化显示与闪烁显像图像估计的危险心肌(MaR)有显着但相反的相关性。在咬合期间观察到的两个相关峰上,MaR与QRS络合物的向下斜率变化之间的相关性为[r = -0.75,p <0.01和r = -0.79,p分别在[公式:参见文本],时间演变中观察到的正挠度和负挠度<0.01。通过评估在主要观察到的正峰处的ST段抬高来分析的复极化变化也显示为负,但与MaR的相关性不显着:r = -0.34,p = 0.28。我们的结果表明,在去极化后期评估的变化(如[公式:请参见文本]所述)受R波幅度,QRS宽度和ST水平变化的同时影响,与缺血量的相关性更好。比在去极化早期或ST段评估的其他指数要高。
  • 【比较“现场”条件下从血清分离器和氟化物/草酸钾血液采集管中采集的成对样本中的葡萄糖浓度。】 复制标题 收藏 收藏
    DOI:10.1016/j.clinbiochem.2012.11.027 复制DOI
    作者列表:Fernandez L,Jee P,Klein MJ,Fischer P,Perkins SL,Brooks SP
    BACKGROUND & AIMS: OBJECTIVES:There are no direct comparisons of blood glucose values in samples collected with barrier serum tubes (SST) and NaF/potassium oxalate (NaF/KOx) plasma tubes. Collection of samples in SST tubes can offer considerable savings and specimen processing advantages for national level surveys. DESIGN AND METHODS:Serum and plasma samples were collected under 'field conditions' from a single draw of 3692 individuals participating in the Canadian Health Measures Survey. The samples were analyzed retrospectively using the VITROS GLU Slide method (glucose oxidase-based). RESULTS:There was a high rate of hemolysis in the NaF/KOx tubes (86.2%) while hemolysis was infrequently observed with the SST tubes (2%). Comparing only blood draws where no hemolysis was observed in both tubes (n=495; paired t-test) showed no effect of tube type on serum/plasma glucose concentrations. This was also observed when data was restricted to cases when only SST samples were not hemolyzed (n=3546; paired t-test). CONCLUSIONS:These data show that both collection tubes can be used under survey collection and processing conditions to measure glucose with our assay system with no difference in reported results.
    背景与目标: 目的:尚无直接比较采用屏障血清试管(SST)和NaF /草酸钾(NaF / KOx)血浆试管收集的样本中血糖值的方法。在SST管中收集样品可以为国家级调查提供大量的节省和样品处理的优势。
    设计与方法:在“现场条件”下从参加加拿大卫生措施调查的3692个人中抽取了血清和血浆样品。使用VITROS GLU Slide方法(基于葡萄糖氧化酶)对样品进行回顾性分析。
    结果:NaF / KOx管的溶血率很高(86.2%),而SST管的溶血率很少(2%)。仅比较在两个试管中均未观察到溶血的抽血情况(n = 495;配对t检验)显示试管类型对血清/血浆葡萄糖浓度无影响。当数据仅限于仅不对SST样品进行溶血的情况时(n = 3546;配对t检验),也可以观察到这一点。
    结论:这些数据表明,在我们的测定系统中,两个收集管均可在调查收集和处理条件下用于测量葡萄糖,报道的结果没有差异。
  • 【客观面部皮肤质量分析后,光老化严重程度的自我认知变化和皮肤癌风险。】 复制标题 收藏 收藏
    DOI: 复制DOI
    作者列表:Bae YC,Bae EJ,Wang JH,Gilchrest BA
    BACKGROUND & AIMS: :

    Background: Despite public education efforts, many people at risk for skin cancer do not practice safe sun behaviors.

    Objective: To determine whether machine-based evaluation of UV-induced alterations (VISIA scan) changes self-assessment of facial photoaging, skin cancer risk, and willingness to improve sun protective habits. In addition, to determine whether VISIA scan analysis reveals differences between those with versus without a history of skin cancer, men versus women, those older than 50 versus less than 50 years of age, and Fitzpatrick skin types I-III versus IV-VI.

    Methods: Volunteers attending a health expo were recruited and queried about their perceived risk of skin cancer and degree of skin photoaging. All participants underwent facial skin quality analysis of both sides of the face, and then completed a follow-up survey.

    Results: Participants' scored self-perceptions of overall skin aging were all statistically significantly worse after VISIA scan analysis. There was no change in perceived skin cancer risk, but most participants expressed intent to improve their sun protection habits.

    Limitations: Limitations to this study include selection bias, recall-misclassification bias, and social desirability bias.

    Conclusion: Intervention with facial skin analysis can positively affect subjects' stated intent to use sun protection, indicating the importance of appearance in these health decisions.

    J Drugs Dermatol. 2017;16(5):453-459.

    .
    背景与目标:

    背景:尽管进行了公众教育,但许多有皮肤癌风险的人仍未进行安全的日晒行为。

    目的:确定是否对紫外线诱发的变化进行基于机器的评估(VISIA扫描)改变面部光老化的自我评估,皮肤癌的风险以及改善防晒习惯的意愿。此外,为了确定VISIA扫描分析是否能揭示出有或没有皮肤癌病史,男性与女性,年龄大于50岁与小于50岁以及Fitzpatrick I-III和IV-VI皮肤类型之间的差异。

    方法:招募参加健康博览会的志愿者,并询问他们对皮肤癌的感知风险和皮肤光老化程度。所有参与者都进行了面部两面的面部皮肤质量分析,然后完成了一项后续调查。

    结果:在进行VISIA扫描后,参与者对整体皮肤衰老的自我感觉评分在统计学上均显着变差分析。知觉的患皮肤癌风险没有改变,但大多数参与者表示有意改善其防晒习惯。

    局限性:本研究的局限性包括选择偏见,召回分类错误和社会可取性偏见。 / p>

    结论:进行面部皮肤分析的干预可以正面影响受试者陈述的使用防晒的意图,这表明在这些健康决定中外表的重要性。

    J Dermatol。 2017; 16(5):453-459。

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