• 【人髌骨血流变化的无创连续估计。】 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: : 已经开发并测试了一种用于评估骨组织血流的光电容积描记 (PPG) 技术。PPG检测到的信号由恒定水平 (DC) 分量 (与组织的相对血管化有关) 和脉动 (AC) 分量组成,该分量与心脏的泵送动作同步。将PPG探针涂在髌骨上的皮肤上。探针使用近红外 (804 nm) 和绿色 (560 nm) 光源,并且两个波长的PPG信号的AC分量分别用于监测髌骨和上覆皮肤中的脉动血流。研究了20名健康受试者,动脉闭塞导致消除了两个波长处的PPG信号,而局部表面压力对皮肤血流的闭塞仅消除了560 nm处的PPG信号。在对具有刚性管的物理模型的并行研究中,我们表明PPG信号的AC分量来自刚性结构中的血流脉动,而不一定来自体积脉动。我们得出的结论是,可以使用目前的PPG技术评估pa骨中的脉动血流。
  • 【在环境臭氧浓度加倍的长期熏蒸成年山毛榉树下,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一个重要但研究不足的部分。到目前为止,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70年历史的云杉-山毛榉混合林分中两个生长季节 (2003-2004年) 的外生菌根真菌群落和山毛榉细根动态,其中两组五棵成年山毛榉树被2倍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在于,以前的研究是在盆栽实验中或在封闭或开放的顶部腔室中对幼苗进行的,而不是在成熟的林分中进行的。尽管山毛榉是对流层O(3) 相对无反应的物种,但我们发现2 x O(3) 对重要的外生菌根根尖和非膨胀细根的数量有明显影响。在每个采样事件中,连续两年与对照组相比,两类根均显着增加。外生菌根的种类和物种丰富度2004年增加,但在极端干燥的2003年中却没有增加。我们假设观察到的变化可能是由O(3) 诱导的对根和根际碳分配的影响引起的生态位地下演替中的过渡状态的表达。我们已经检测到外生菌根物种水平的变化,但是Shannon-Weavers物种多样性指数和外生菌根类型的百分比在任何采样年份都没有显着变化,因此表明我们的结果不能通过2003年夏季干旱或O(3) 来明确解释。单独暴露。
  • 【囊性纤维化患者在呼气正压和振荡呼气正压胸部理疗期间血气紧张的即时变化。】 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:
  • 【苯巴比妥依赖性和退缩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) 依赖性和退缩大鼠大脑中谷氨酸受体的变化,即刻早期基因的表达以及AP-1的DNA结合活性,以研究谷氨酸受体激活在PB戒断综合征中的可能参与。通过喂养混合药物的食物5周制备PB依赖性大鼠。放射自显影分析显示,N-甲基-d-天冬氨酸 (NMDA) 受体拮抗剂 [3H(+)-5-甲基-10,11-二氢-5H-二苯并 [a,D] cyclohepten-5,10-敏e (MK-801) 的结合,PB依赖性和24h撤回大鼠的大脑皮层显着增加。然而,[3h] MK-801在海马和 [3H]6-氰基-7-硝基喹喔啉-2结合,海马和大脑皮层中的3-二酮 (CNQX) 和 [3H] 海藻酸结合在两组中基本上没有变化。铅戒断发作后,海马和大脑皮层中c-fos mRNA的表达增加,大脑皮层中c-6月mRNA的表达增加。诱导c-MK-801可抑制fos和c-6月mRNA。此外,铅戒断增强了大脑中的AP-1 DNA结合活性。目前的发现表明,在铅戒断综合征的发展过程中,谷氨酸能神经传递的功能增强。
  • 【21世纪边缘的职业医学: 对预防方法中已完成和预期变化的评估。】 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 “投资于健康” (1993) 的文件中指出,包括工作人口在内的人口的健康状况和各个国家的工作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重大变化。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自己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,这导致了劳动力市场的激烈竞争。在政治,社会和经济转型的国家中,古斯塔夫森在第25届国际职业健康大会上描述的引入新的可持续发展体系的条件尚未建立。涉及雇主和工人代表之间谈判的基于程序的系统未能成功改善工作条件,因为国家,雇主和工会的作用尚未得到准确定义。预计这些国家工作场所的进一步健康促进将主要取决于经济进步和教育制度的改革。
  • 【表型转换导致平滑肌肌膜的结构和功能改变。】 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: : 平滑肌长度的持续变化需要高度组织化的肌膜结构。然而,平滑肌细胞也迅速适应改变的环境线索。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以及收缩力。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均含有较高的胆固醇与甘油磷脂比例,并且表达与脂质相关的膜联蛋白的范围较少。这些发现表明上皮样细胞的膜分离效率降低。此外,与纺锤形细胞相比,胆固醇更容易从上皮样细胞中提取甲基-β-环糊精,其合成更容易受到洛伐他汀的抑制。上皮样细胞无法处理血管活性代谢产物,例如血管紧张素或核苷酸,进一步表明收缩特性受损。表型可塑性超出了平滑肌细胞标记基因的丧失。质膜发生了深刻的功能变化,与循环缩短不相容,但在血管疾病的发展中可能很重要。
  • 【由携带唾液酸a抗原的粘蛋白结合引起的E-选择素的代谢变化。】 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: 从大肠癌患者的腹水中分离出携带唾液酸抗原 (sl-gp) 的粘蛋白型糖蛋白。SL-GP以Ca2 + 和唾液酸抗原依赖的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,内皮细胞用32p磷酸盐或35S-Met和35S-Cys标记。通过与SL-GP连接而不是与唾液酸六糖连接,E-选择素的一个或多个丝氨酸残基的磷酸化升高。在SL-GP存在下,用35S-Met和35S-Cys对E-选择素进行脉冲标记表明,SL-GP连接可加速E-选择素的降解,但用SL-GP预连接后标记显示E-选择素的合成增加。合成可能反映了对预连接时降解的E-选择素的补偿。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,包括凝血、炎症、血管生成和上皮化。趋化因子家族已被证明包含许多这些途径的有效调节剂。因为我们以前已经表明趋化因子在生物伤口敷料中 “聚集”,所以我们连续研究了一组接受慢性静脉腿部溃疡治疗的患者的CXC和CC趋化因子以及关键炎症介质的水平。8周后,所有患者的溃疡临床愈合明显 (中位63.3% 缩小),其中10例中有2例完全愈合。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 诱导蛋白,在伤口闭合期间从溃疡中心收集的组织中,血管生成与血管抑制CXC趋化因子 (p = 0.082) 的总和比率呈增加趋势。中性粒细胞激活肽-2和interleukin-8占伤口流体血管生成趋化因子的最大变化,与基线水平和患者血浆水平相比,在第0周和第8周之间的不同时间点存在显着差异。与血浆水平相比,血管抑制趋化因子,干扰素y诱导蛋白10和血小板活化4的水平在第0周和第3周之间下降最明显。观察到的向血管生成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使溃疡床 “移至” 更有利于上皮形成的状态,这是伤口愈合增生期的特征。与患者血浆水平相比,伤口液体样品中的CC趋化因子在基线时也升高。巨噬细胞炎性蛋白-1 (3) 和受激活调节,正常T表达和分泌 (RANTES) 水平随愈合而降低,而在治疗的前4周内,单核细胞趋化蛋白-1和巨噬细胞炎性蛋白-1 a的组织水平显着增加 (两者p <或 = 0.05)。与这些变化同时发生的是,interleukin-1 R/interleukin-1受体拮抗剂蛋白的比例在溃疡中心组织,与溃疡边缘的比率降低相比,这也与愈合相关 (p <0.05),和伤口液体中的双相反应。这些发现表明,先进的伤口护理技术有助于将溃疡从慢性炎症状态转移到伤口愈合的晚期炎症/早期增生期的另一个特征。趋化因子可能通过其对血管生成的影响在慢性静脉溃疡的发病机理中发挥关键作用和/或损伤部位炎症反应的进展。
  • 【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: : 在肝再生过程中从大鼠肝脏制备的亚线粒体颗粒表现出降低的ATPase活性,这与F1亚基含量的降低有关,如sdds-PAGE所示。使用针对H-ATPase复合物的F1部分的抗体表明,部分肝切除术后24小时,大鼠肝脏的线粒体颗粒和线粒体中F1的 β 亚基数量均明显减少。
  • 【腰椎骨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:
  • 【痴呆磁共振成像的认知和白质变化。】 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例阿尔茨海默氏病患者中的11例和11例血管性痴呆患者中的8例具有明显的脑室周围高信号。在痴呆症的早期研究中进行记忆和语言测试可用于在磁共振成像上区分有无脑室周围高信号的患者。没有脑室周围高强度的患者在记忆和概念化测试上比脑室周围高强度的患者更差,后者在理解和注意力测试上往往更差。这些认知模式的差异存在于具有不同发病机理的患者之间,这些患者在痴呆严重程度上是匹配的。语言和某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相关。
  • 【胆囊体积的变化不影响胆囊管阻力。】 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,胆囊体积与胆囊管功能之间的关系尚未得到研究。我们假设胆囊体积的变化会影响胆囊管阻力。在12只狗中,在基础胆囊收缩素刺激的条件下,使用多端口导管在胆囊内放置了高度顺应性球囊,测试了胆囊体积变化对胆囊管对顺行 (排空) 和逆行 (充盈) 稳态血流的阻力的影响。胆囊底。胆囊体积通过改变从空的球囊体积到超出生理扩张来调节。在基础或刺激条件下,囊管阻力不受球囊体积或灌注液流动方向的影响。这项研究表明胆囊体积与胆囊管阻力之间没有关系,也没有显示生理性胆囊体积的胆囊管括约肌机制。
  • 【猪心肌梗死模型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13头猪的40分钟冠状动脉球囊充气产生的心肌梗死实验模型中,评估了急性心肌缺血期间对应于心室去极化和复极化的几种心电图 (ECG) 衍生指标。从冠状动脉闭塞开始后的第4分钟开始迅速观察到显着变化,分别在去极化11至22分钟和复极化指数9至12分钟之间达到最大值。随后,在闭塞的后期,这些最大变化开始减少。与QRS复合物的后半部分相关的去极化变化与闪烁显像估计的危险心肌 (MaR) 呈显着但呈负相关。在闭塞期间观察到的两个更相关的峰处评估的MaR与QRS复合体向下斜率的变化之间的相关性为r = -0.75,p <0.01和r = -0.79,对于在 [公式: 参见文本] 中观察到的正偏转和负偏转,分别为p <0.01。通过评估主要观察到的正峰处的ST段抬高来分析复极化变化,也显示出负的,但与MaR无关: r = -0.34,p = 0.28。我们的结果表明,在去极化的后半部分评估的变化,例如 [公式: 参见文本] 所描述的变化,同时受到R波振幅,QRS宽度和ST电平变化的影响,与在去极化早期或ST段期间评估的其他指标相比,与缺血量的相关性更好。
  • 【客观面部皮肤质量分析后,光老化严重程度和皮肤癌风险的自我认知变化。】 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: 尽管进行了公共教育,但许多有患皮肤癌风险的人并未实践安全的阳光行为。

    目的: 确定基于机器的紫外线诱导改变评估 (VISIA scan) 是否会改变面部光老化的自我评估,皮肤癌风险和改善防晒习惯的意愿。此外,为了确定VISIA扫描分析是否揭示了有皮肤癌病史与没有皮肤癌病史的人,男性与女性,50岁以上与50岁以下的人以及Fitzpatrick皮肤类型i-iii与iv-vi之间的差异。

    方法: 参加健康博览会的志愿者被招募并询问他们对皮肤癌的感知风险和皮肤光老化的程度。所有参与者都对面部两侧进行了面部皮肤质量分析,然后完成了后续调查。

    结果: VISIA扫描分析后,参与者对整体皮肤老化的评分自我认知均在统计学上显着下降。皮肤癌风险的感知没有变化,但大多数参与者表示有意改善他们的防晒习惯。

    局限性: 这项研究的局限性包括选择偏见,召回错误分类偏见和社会期望偏见。

    结论: 面部皮肤分析的干预可以积极影响受试者使用防晒的既定意图,表明外观在这些健康决定中的重要性。

    J药物皮肤科。2017;16(5):453-459。

  • 【行为大鼠下牙槽神经横断后三叉神经节和丘脑神经元活动的长期变化。】 复制标题 收藏 收藏
    DOI:10.1523/JNEUROSCI.1828-12.2012 复制DOI
    作者列表:Tseng WT,Tsai ML,Iwata K,Yen CT
    BACKGROUND & AIMS: :The transection of the inferior alveolar nerve (IANx) produces allodynia in the whisker pad (V2 division) of rats. Ectopic discharges from injured trigeminal ganglion (TG) neurons and thalamocortical reorganization are possible contributors to the sensitization of uninjured V2 primary and CNS neurons. To test which factor is more important, TG and ventroposterior medial nucleus (VPM) neurons were longitudinally followed before, during, and after IANx for up to 80 d. Spontaneous discharges and mechanical stimulation-evoked responses were recorded in conscious and in anesthetized states. Results show (1) a sequential increase in spontaneous activities, first in the injured TG neurons of the IAN (2-30 d), followed by uninjured V2 ganglion neurons (6-30 d), and then VPM V2 neurons (7-30 d) after IANx; (2) ectopic discharges included burst and regular firing patterns in the IAN and V2 branches of the TG neurons; and (3) the receptive field expanded, the modality shifted, and long-lasting after-discharges occurred only in VPM V2 neurons. All of these changes appeared in the late or maintenance phase (7-30 d) and disappeared during the recovery phase (40-60 d). These observations suggest that ectopic barrages in the injured IAN contribute more to the development of sensitization, whereas the modality shift and evoked after-discharges in the VPM thalamic neurons contribute more to the maintenance phase of allodynia by redirecting tactile information to the cortex as nociceptive.
    背景与目标: : 下牙槽神经 (IANx) 的横切在大鼠的晶须垫 (V2分区) 中产生异常性疼痛。受损的三叉神经节 (TG) 神经元的异位放电和丘脑皮层重组可能是未受损的V2初级和CNS神经元致敏的原因。为了测试哪个因素更重要,在IANx之前,期间和之后纵向跟踪TG和腹后内侧核 (VPM) 神经元长达80 d。在有意识和麻醉状态下记录自发放电和机械刺激诱发反应。结果表明 (1) 自发活动依次增加,首先是IAN损伤的TG神经元 (2-30 d),其次是未损伤的V2神经节神经元 (6-30 d),然后是VPM V2神经元 (7-30 d)。IANx后的d); (2) 异位放电包括TG神经元的IAN和V2分支中的爆发和规则放电模式; (3) 感受野扩大,模态改变,并且仅在VPM V2神经元中发生持久的放电。所有这些变化都出现在后期或维护阶段 (7-30 d),并在恢复阶段 (40-60 d) 消失。这些观察结果表明,受伤的IAN的异位弹幕对敏化的发展做出了更大的贡献,而VPM丘脑神经元的模态变化和诱发的放电后放电通过将触觉信息重定向到皮层作为伤害性,对异常性疼痛的维持阶段做出了更大的贡献。

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