Myocardial dysfunction and abnormal left ventricular exercise response in autonomic diabetic patients

In diabetic patients, the pathophysiologic mechanisms of exercise-induced left ventricular (LV) dysfunction remain controversial. In this study, the role of myocardial contractility recruitment in determining an abnormal LV response to isometric or dynamic exercise has been investigated in 14 diabetic patients with autonomic dysfunction. Ischemic heat disease was excluded by the absence of LV wall motion abnormalities induced by isotonic and isometric exercise and by coronary angiography. Left ventricular and myocardial function were studied at rest, and during isometric and isotonic exercise, by two-dimensional echocardiography; moreover, recruitment of an inotropic reserve was assessed by postextra-systolic potentiation at rest and at peak handgrip. An abnormal response of LV ejection fraction to isometric (9/14) or to dynamic (8/14) exercise was frequent in study patients. In these patients, baseline myocardial contractility was normal, and the significant increase in ejection fraction by postextrasystolic potentiation indicated a normal contractile reserve (65 ± 7% vs. 74 ± 6%, p=0.001). Nevertheless, the downward displacement of LV ejection fraction-systolic wall stress relationships during exercise suggests an inadequate increase in myocardial contractility. However, the abnormal ejection fraction at peak handgrip was completely reversed by postextrasystolic potentiation (67 ± 6% vs. 58.1 ± 10%, p=0.008), a potent inotropic stimulation independent of the integrity of adrenergic cardiac receptors. A defective inotropic recruitment, despite the presence of a normal LV contractile reserve, plays an important role in deexercise LV dysfunction in diabetic patients with autonomic neuropathy.     

ARE THE STRUCTURAL CHANGES IN ADULT DROSOPHILA MUSHROOM BODIES MEMORY TRACES? STUDIES ON BIOCHEMICAL LEARNING MUTANTS

The pre-imaginal development of Drosophila mushroom bodies is under the influence of an unknown variable which causes populations of wild-type flies at eclosion to differ in the average number of Kenyon cell fibers. During the first week of adult life the number adjusts to an intermediate level which depends upon the experience of the flies. Under olfactory deprivation or social isolation it reaches a lower level than under favorable rearing conditions (J. Neurogenet., 1 (1984) 113–126). The biochemical learning mutants dunce and rutabaga show no experince-dependent modulation of fiber number (Fig. 2). In both strains the mushroom bodies of young adults seem to develop abnormally; in dunce a loss of aboout 600 fibers is observed, in rutabaga fiber number is low at eclosion and does not increase (Fig. 1a). The following model for long-term memory is proposed: in mushroom bodies outgrowth and decay of Kenyon cell fibers occur simultaneously. The fibers randomly form transient synapses onto extrinsic output neurons of the mushroom bodies and receive synapses from modulating neurons. Experience consolidates certain synapses, thus prolonging survival of the respective Kenyon cell fibers and increasing the steady state level of fiber number (Fig. 3).     

Long-term functional outcomes after an external femoral derotation osteotomy in individuals with cerebral palsy

BackgroundIt is unknown how a femoral derotation osteotomy (FDO) during childhood affects functional outcomes in adulthood among individuals with bilateral cerebral palsy (CP).Research questionsHow do long-term functional outcomes after an FDO compare to matched individuals who did not have an FDO? How do outcomes change over time?MethodsWe queried the gait laboratory database for individuals who underwent an external FDO in childhood and were currently ≥25 years old. Participants returned for a long-term analysis (gait, physical examination, functional tests, imaging, questionnaires). The matched non-FDO group included only individuals in Gross Motor Function Classification System levels I-II, yielding three groups (non-FDO I-II, FDO I-II, FDO III-IV).ResultsSixty-one adults (11 non-FDO, 34 FDO I-II, 16 FDO III-IV) returned 13–25 years after baseline (non-FDO) or surgery (FDO). The non-FDO and FDO I-II groups were matched at baseline on most variables, except the FDO group had weaker hip abductors. At long-term, groups were similar on gait variables (median long-term hip rotation [primary outcome], non-FDO: −4°, FDO I-II: −4°, FDO III-IV: −5°), hip abduction test, fear of falling, and most pain measures despite anteversion being 29° greater in the non-FDO group. The FDO I-II group reported more falls than the non-FDO group. All groups improved on hip rotation, foot progression, and hip abductor strength. Speed and step length decreased/tended to decrease for all three groups. Hip abduction moment and gait deviation index did not change. Improvements in the FDO groups were maintained from short- to long-term.SignificanceThese results challenge the notion that an FDO is necessary to correct mean stance hip rotation for higher functioning individuals since nearly identical results were achieved by adulthood in the non-FDO I-II group. However, an FDO provides improvement earlier and maintenance from short- to long-term. This should factor into the shared decision-making process.     

Offset-related brain activity in the left ventrolateral prefrontal cortex promotes long-term memory formation of verbal events

BackgroundRecent evidence suggests that brain activity following the offset of a stimulus during encoding contributes to long-term memory formation, however the exact mechanisms underlying offset-related encoding are still unclear.ObjectivesHere, in three repetitive transcranial magnetic stimulation studies (rTMS) we investigated offset-related activity in the left ventrolateral prefrontal cortex (VLPFC). rTMS was administered at different points in time around stimulus offset while participants encoded visually-presented words or pairs of words. The analyses focused on the effects of the stimulation on subsequent memory performance.ResultsrTMS administered at the offset of the stimuli, but not during online encoding, disrupted subsequent memory performance. In Experiment 1 we found that rTMS specifically disrupted encoding mechanisms initiated by the offset of the stimuli rather than general, post-stimulus processes. Experiment 2 showed that this effect was not dependent upon rTMS-induced somatosensory effects. In a third rTMS experiment we further demonstrated a robust decline in associative memory performance when the stimulation was delivered at the offset of the word pairs, suggesting that offset-related encoding may contribute to the binding of information into an episodic memory trace.ConclusionsThe offset of the stimulus may represent an event boundary that promotes the reinstatement of the previously experienced event and episodic binding.     

Long-term follow-up of intersegmental displacement after orthognathic surgery using cone-beam computed tomographic superimposition

ObjectivesTo evaluate intersegmental displacement during long-term follow-up after bilateral sagittal split osteotomy (BSSO) by mandibular body area superimposition.Materials and MethodsCone-beam computed tomography (CBCT) images of 23 patients ages 18−37 years with class III malocclusion before orthognathic surgery were obtained. A three-dimensional (3D) CBCT examination was performed at four stages: surgery (T0), 6 months after surgery (T1), 1 year after surgery (T2), and long-term follow-up (6.1 ± 2.1 years, T3). The CBCT datasets were superimposed on the symphyseal area and the lower part of the distal segment of the mandible between T0 and the other time points (T1, T2, and T3). The reference points (both condyle, coronoid, and sigmoid) were estimated by the CBCT analyzed program.ResultsThe coronoid, condylion, and sigmoid showed changes within 6 months after surgery, but there was no significant change in the intersegmental displacement between 6 months and 6 years after surgery. The distances between the left and right coronoid, condylion, and sigmoid from T0 to T3 were noted.ConclusionsThe change in intersegmental displacement between T0 and T3 affecting relapse after orthognathic surgery was not significantly different. This suggests that the mandible itself may have a stable morphology during the follow-up period.     

不同包装和贮藏条件下酸枣仁的质量比较

目的:确定酸枣仁适合的贮藏条件、包装材料和包装方式,为保障酸枣仁质量提供参考。方法:选用同一批酸枣仁样品,分别采取塑料编织袋包装、塑料袋包装、塑料袋真空包装、铝塑复合袋包装、铝塑复合袋真空包装和牛皮淋膜纸袋包装,贮藏在阴凉库(温度≤20℃、相对湿度为45%~75%)和药品稳定性试验箱[温度为(40±2)℃、相对湿度为(75±5)%]中,以性状及水分、黄曲霉毒素、酸枣仁皂苷A、斯皮诺素含量为考察指标,开展为期6个月的阴凉长期稳定性试验和加速稳定性试验研究。结果:6个月阴凉长期稳定性试验结果显示,不同包装条件下酸枣仁样品的性状以及水分、黄曲霉毒素、酸枣仁皂苷A含量均符合2015年版《中国药典》(一部)(后文简称"药典")酸枣仁项下规定;斯皮诺素含量均不符合药典的规定(不低于0.080%),但其中铝塑复合袋真空包装样品中斯皮诺素含量(0.079%)与药典要求接近。6个月加速稳定性试验结果显示,牛皮淋膜纸袋包装、塑料编织袋包装样品发霉严重,塑料袋包装、塑料袋真空包装样品表面颜色变暗,铝塑复合袋包装样品颜色稍变暗,但铝塑复合袋真空包装样品外观基本无变化;塑料编织袋包装、牛皮淋膜纸袋包装样品中水分含量超过了药典要求最高值(9.0%);仅在贮藏2个月时,编织塑料袋包装样品被检出黄曲霉毒素B1含量为8.64μg/kg,超出药典规定;各包装样品中酸枣仁皂苷A含量虽有下降,但均满足药典要求;仅塑料袋真空包装样品中斯皮诺素含量(0.084%)满足药典要求,其次属铝塑复合袋真空包装样品中含量(0.071%)相对较高。结论:酸枣仁以铝塑复合袋真空包装后置于阴凉干燥处为宜。     

Effect of the length of orthodontic mini-screw implants on their long-term stability: A prospective study

Objective:To analyze the influence of the length of temporary intraoral skeletal anchorage devices (TISAD/TAD) on their long-term stability in the mandible in a homogenous group of patients.Materials and Methods:A group of generally healthy patients of the same gender (female) and with a statistically insignificant age difference (20–29 years) highly homogenous with respect to known factors affecting the success rate of TISAD/TAD was evaluated. One type of TISAD/TAD was applied (6- or 8-mm long). Each patient received both 6- and 8-mm-long TISAD/TAD in randomly selected mandibular quadrants: left or right. The long-term success rate of TISAD/TAD was analyzed.Results:The 8-mm orthodontic mini-screw implants were significantly more stable than the 6-mm ones in the analyzed group.Conclusion:The length of the TISAD/TAD may be one of the factors that can affect the long-term success rate in the mandibles of 20- to 29-year-old women.     

Predictive value of myocardial tomoscintigraphy in asymptomatic diabetic patients after percutaneous coronary intervention

Objective: This study was designed to assess the prognostic value of myocardial tomoscintigraphy perfusion imaging after percutaneous coronary intervention (PCI) in asymptomatic diabetic patients. Methods: One hundred and fourteen diabetic patients were followed up during 27±16 (mean±SD) months after the myocardial tomoscintigraphy. PCI-related events were studied after myocardial tomoscintigraphy stress testing and included major cardiac events (MACE) (cardiovascular death, myocardial infarction) and revascularization (bypass surgery or new PCI). Stress myocardial tomoscintigraphy imaging was performed 5±5 months after PCI and ischemia was considered as present if at least 2 contiguous segments were showing reversible defects. Results: Persistent silent ischemia was found in 49/114 (43%) patients. No difference was observed between the two groups for MACE: four among the 65 (6%) non ischemic patients versus 2 among the 49 (4%) ischemic patients (NS). In contrast, 15 (31%) among the ischemic patients and 4 (6%) among the non ischemic patients underwent iterative revascularization (p<0.01). The relative risk of revascularization for patients with significant ischemia was 5.5 versus non ischemic patients (p<0.001). Conclusion: After PCI, in asymptomatic diabetic patients followed by myocardial tomoscintigraphy a high frequency of persistent silent ischemia was found and associated with a high risk for repeat interventional procedure, although no increase in major cardiac events was observed.     

京津地区养老机构《老年人营养不良风险评估》应用效果评价研究

背景　营养筛查与评估是开展规范化营养支持的基础,WS/T 552-2017《老年人营养不良风险评估》发布前后,尚缺乏关于此标准中评估工具信效度研究的有关报告。目的　评价《老年人营养不良风险评估》在京津地区有代表性的养老机构应用的信效度。方法　2019年5-6月,采用方便抽样对北京、天津7家养老机构中入住的444名老年人进行问卷调查。采用临界比、条目-总分相关系数、探索性因子分析、Cronbach's α系数和折半信度系数评价《老年人营养不良风险评估》的信效度。结果　共发放问卷474份,回收有效问卷444份,有效回收率为93.7%。《老年人营养不良风险评估》各条目临界比为-1.992~13.272,条目-总分相关系数为-0.051~0.566;探索性因子分析共提取8个公因子,累积解释变异量为62.069%,4个条目因子载荷<0.40而未达标准;《老年人营养不良风险评估》的Cronbach's α系数为0.323,折半信度为0.531,8个公因子的Cronbach's α系数为-0.542~0.649,折半信度为-0.424~0.637。结论　《老年人营养不良风险评估》在养老机构中应用时部分条目的鉴别度和同质性不高,结构效度和内部一致性不是非常理想,在进行养老机构老年人营养状况筛查与评价时,需要对条目进一步斟酌,才能更有效地评价养老机构老年人的营养状况。