The time course of postflight simulator sickness symptoms

Reports of posteffects following training sessions in Navy and Army flight simulators were obtained from pilots to determine the time course of recovery from simulator sickness. Results imply that posteffects may be a more serious problem than previously considered; 45% of all those queried (N greater than 700) reported having experienced symptoms of simulator sickness; 25% of the symptoms lasted more than 1 h after leaving the simulator; and 8% lasted more than 6 h. Postexposure symptoms were classified into three categories: visuomotor (based on disturbances in oculomotor control; e.g., eyestrain), disorientation (based on disturbance in postural control; e.g., dizziness), and nausea (vagal/autonomic symptoms). A safety risk may be posed particularly by the moderately high frequency of symptoms involving postural disequilibrium. Guidelines for coping with risks are discussed.     

Peripheral facial nerve dysfunction: CT evaluation

Peripheral facial nerve dysfunction may have a clinically apparent or occult cause. We reviewed the clinical and radiographic records of 36 patients with peripheral facial nerve dysfunction to obtain information on the location of the suspected lesion and the number, sequence, and type of radiographic evaluations performed. Inadequate clinical evaluations before computed tomography (CT) was done and unnecessary CT examinations were also noted. In those patients in whom the cause of peripheral facial nerve dysfunction is apparent, the clinical-radiographic workup is self-evident. When the cause of dysfunction is occult, however, a tailored CT examination should be done based on a thorough clinical evaluation. We have suggested a practical clinical and radiographic scheme to evaluate progressive peripheral facial dysfunction with no apparent cause. If this scheme is applied, unnecessary radiologic tests and delays in diagnosis and treatment may be avoided.     

Mechanism of postflight decline in osmotic concentration of urine in cosmonauts.

The ratio of reabsorption of osmotically free water to osmolal clearance in individual urine voids was about the same before and after short-term spaceflights (the points fall on the same regression line). This ratio was reduced after long-term flights, so that the regression lines for pre- and postflight values have different slopes. This change in the function relating the two factors was accompanied by increased vasopressin in blood plasma and probably was caused by altered cellular reaction to vasopressin. The decrease in the effect of vasopressin may have been caused by development of hypokalemia and hypercalcemia in the cosmonauts, and decrease in cellular potassium in the outer renal medulla (this effect was observed in experiments on rats after flights on biosatellites). We established that, in addition to cAMP, cGMP and inositol trisphosphate participate in cellular reactions to vasopressin. Increases in the concentration of cGMP and decrease in the formation of inositol trisphosphate in the presence of neomycin increase the hydro-osmotic effect of vasopressin. We hypothesize that modulation of the effect of vasopressin in cosmonauts is due to change in the functional state of their kidneys.     

Role of interleukin-6 levels in cardiovascular autonomic dysfunction in type 2 diabetic patients

PURPOSE: Increased serum interleukin-6 (IL-6) levels are associated with an increased risk of cardiovascular disease, and cardiovascular autonomic dysfunction is associated with high mortality in type 2 diabetic patients. However, the relationship between IL-6 levels and cardiovascular autonomic dysfunction has not been fully elucidated. The aim of this study was to determine whether serum IL-6 levels are associated with cardiovascular autonomic dysfunction in type 2 diabetic patients. METHODS: Eighty type 2 diabetic patients who did not have organic heart disease were categorized into a high IL-6 group (>2.5 pg/ml, n = 40, age 59 +/- 12 years) or a non-high IL-6 group (<2.5 pg/ml, n = 40, 61 +/- 12 years). Cardiac autonomic function was assessed by baroreflex sensitivity, heart rate variability, plasma norepinephrine concentrations and (123)I-metaiodobenzylguanidine (MIBG) scintigraphy. RESULTS: The body mass index values (BMI), fasting insulin levels and homeostasis model assessment index values were higher in the high IL-6 group than in the non-high IL-6 group (p < 0.01). Early and delayed (123)I-MIBG myocardial uptake values were lower (p < 0.01), and the percent washout rate of (123)I-MIBG was higher (p < 0.05) in the high IL-6 group than in the non-high IL-6 group. Furthermore, multiple regression analysis revealed that the IL-6 level was independently predicted by the BMI and the myocardial uptake of (123)I-MIBG during the delayed phase. CONCLUSIONS: The results indicate that elevated IL-6 levels are associated with depressed cardiovascular autonomic function and obesity in type 2 diabetic patients.     

脑转移瘤放射治疗后认知功能障碍机制及可能的防治策略

放射治疗一直是脑转移瘤有效的非手术治疗手段,随着脑转移瘤患者生存期的不断延长,潜在放疗相关的认知功能损伤逐渐被重视。在保证肿瘤有效控制的同时,对患者的生活质量和神经认知功能都有所关注,以改善患者的预后。本文主要针对脑转移瘤患者的放射治疗及神经认知功能保护的相关研究进行综述。     

丰富环境对辐射诱导小鼠认知障碍的保护作用及可能机制

目的 研究丰富环境对辐射诱导小鼠认知功能障碍的保护作用及其可能机制。方法 将45只2月龄雌性昆明小鼠采用随机数表法分为对照组、照射组和照射丰富环境组,每组15只。照射组和照射丰富环境组予以单次4 Gy全身¹³⁷Cs γ射线照射,照射丰富环境组辐射后连续35 d给予丰富环境刺激。新旧事物识别实验检测小鼠认知功能;免疫组织化学方法检测小鼠海马区小胶质细胞标记物IBA-1的表达;Western blot方法检测小胶质细胞激活标记物CD68及突触囊泡素（SYP）的表达。结果 与对照组相比,照射组小鼠在新旧事物识别实验中新事物分辨率降低,海马区IBA-1阳性细胞数目增加,CD68蛋白表达升高,SYP蛋白表达降低（t=3.66、6.83、5.79、6.84,P<0.05）。与照射组相比,照射丰富环境组小鼠新事物分辨率升高,海马区IBA-1阳性细胞数目减少,CD68蛋白表达降低,SYP蛋白表达增加（t=3.56、7.69、4.59、4.06,P<0.05）。结论 4 Gy单次全身¹³⁷Cs γ射线照射可构建放射性认知功能障碍模型,丰富环境可改善模型小鼠认知功能,其机制可能与抑制海马区小胶质细胞激活以及减少神经元突触丢失有关。     

CMR-FT技术评估肺高血压患者早期右心室功能障碍

目的:采用心脏磁共振特征追踪(CMR-FT)技术定量评估肺高血压(PH)患者右心室心肌应变,探究其早期检测右心室功能障碍的价值.方法:回顾性收集确诊P H患者40例,健康成年人15例,均行CMR检查,根据右心室射血分数(RVEF)是否减低(<45％)将PH患者分成RVEF保留组(pRVEF PH组)和减低组(rRVEF...     

羟基积雪草苷对大鼠创伤性颅脑损伤后神经功能障碍的改善作用及机制研究

目的 探讨羟基积雪草苷(MC)对大鼠创伤性颅脑损伤(TBI)后神经功能障碍的改善作用及机制.方法 SPF级雄性SD大鼠64只(200～220g/只),采用随机数字表法均分为四组:假创伤组、创伤组、创伤后低剂量MC组(25mg/kg)、创伤后高剂量MC组(75mg/kg)各16例.根据控制性皮层损伤法,创伤组、低剂量MC...     

乌司他丁对重症中暑小鼠心功能损害的保护作用及机制研究

目的 研究乌司他丁对重症中暑所致小鼠心功能损害的保护作用,并进一步探讨其可能机制.方法 BALB/c小鼠20只按随机数字表法分为常温+生理盐水组(Sham+NS组)、常温+乌司他丁组(Sham+UTI组)、热打击+生理盐水组(HS+NS组)、热打击+乌司他丁组(HS+UTI组)4组,每组5只.在热打击开始前腹腔注射乌司他丁105U/kg进行预处理.常温两组置于环境温度23.0±0.5℃条件下,热打击两组置于高温气候动物培养箱(温度36.5±0.5℃,湿度65.0％±2.0％)内,以直肠温度(Tr)达42℃作为重症中暑标准.达中暑标准后,移至常温(23.0±0.5℃)进行自然降温处理,降温6h后进行心脏超声检测,分离心肌组织,进行病理学观察,Western blotting检测总p38及磷酸化p38(p-p38)含量.结果 在中暑热打击组中,HS+UTI组小鼠体温达42℃的时间较HS+NS组明显延长(P=0.044).与Sham+NS组相比,HS+UTI组与HS+NS组动物心输出量(CO)均明显下降(P=0.017),炎症损伤评分明显升高(P＜0.001),p-p38/p38比值升高(P＜0.001),而HS+UTI组CO下降程度明显低于HS+NS组(P=0.030),对应的炎症损伤评分(p＜0.001)及p-p38/p38比值(P=0.001)也均明显低于HS+NS组.结论 重症中暑热打击可导致小鼠心肌炎性损伤和心功能障碍,而乌司他丁对重症中暑小鼠心功能具有保护作用,可能与其下调p-p38水平,减轻心肌组织炎症损伤有关.     

慢性强迫游泳运动对大鼠放射性认知功能障碍的影响及其机制

目的 探讨慢性强迫游泳运动对大鼠放射性认知功能障碍是否有改善作用及其相关机制。方法 将39只1月龄SD大鼠按随机数字表法分成对照组（C）、对照游泳组（C-S）、照射组（R）和照射游泳组（R-S）。照射组给予单次20 Gy全脑照射,游泳组进行15 min/d,5 d/周的强迫游泳运动。照射后第3个月依次进行自发活动、Morris水迷宫（定向航行、空间探索）行为学检测,完成后取大鼠海马组织,用Western blot方法测定各组大鼠海马中脑源性神经营养因子（BDNF）、磷酸化细胞外调节蛋白激酶（P-ERK）、总细胞外调节蛋白激酶（T-ERK）、磷酸化的环磷腺苷效应元件结合蛋白（P-CREB）和总环磷腺苷效应元件结合蛋白（T-CREB）的分子水平。结果 Morris水迷宫定向航行实验中,对照游泳组第2天平均潜伏期低于对照组,对照组及照射游泳组第2天平均潜伏期低于照射组（P<0.05）。自发活动、Morris水迷宫空间探索实验各组之间差异无统计学意义（P>0.05）。Western blot检测,与对照组比较,电离辐射显著降低了BDNF及其下游信号分子P-ERK和P-CREB的表达（P<0.05）,但是强迫游泳运动改善了这种情形,显著提高了照射组BDNF及其下游信号分子P-ERK和P-CREB的表达（P<0.05）。结论 慢性强迫游泳运动可改善大鼠放射性认知功能障碍,其机制可能是促进海马内BDNF及其下游信号分子P-ERK和P-CREB的表达。     

Myocardial scar and insulin resistance predict cardiovascular events in severe ischaemic myocardial dysfunction: a perfusion-metabolism positron emission tomography study

BACKGROUND: Clinical outcome can be predicted by metabolism-perfusion positron emission tomography (PET) in patients with severe ischaemic left ventricular dysfunction. This study determined whether the amount of viable or non-viable myocardium detected with a PET scan or clinical-functional parameters might predict cardiovascular events. METHODS: All patients had previous myocardial infarction (>6 months previously) and left ventricular ejection fraction (LVEF) <40%. Metabolism-perfusion PET, echocardiogram and coronary angiography were provided. All subjects underwent short euglycaemic-hyperinsulinaemic clamp before the metabolism study. The dysfunctioning segment was defined as hibernating myocardium when metabolism was normal-moderately reduced with impaired perfusion (mismatch flow-metabolism). Cardiac death, hospital admission for myocardial infarction or heart failure were considered cardiovascular events. RESULTS: Ninety-three patients (71 males, aged 64.2 years) were studied. The LVEF was 30.2+/-7.7%; 48 (51.6%) suffered an anterior myocardial infarction. Fifty-three (54.1%) subjects were treated with coronary revascularization; all had optimal medical therapy. Cardiovascular events occurred in 20/93 patients at 1-year follow-up (event group). Age (P=0.7), diabetes mellitus (P=0.6) and rate of coronary revascularization (P=0.3) were not different in the two groups. Patients who experienced cardiovascular events had larger non-viable myocardium (5.8+/-2.7 vs. 4.1+/-2.6, P=0.01), lower metabolic rate glucose (1.3+/-0.6 vs. 1.7+/-0.7 ml . kg . min, P=0.04) but similar hibernating myocardium (1.6+/-1.6 vs. 1.7+/-2, P=0.8) and baseline LVEF (28.1+/-4.8 vs. 30.7+/-8.3%, P=0.08). Having more then five non-viable segments and a metabolic rate for glucose of <0.9 mg . kg . min predicted a worse prognosis (P=0.04, log rank, 3.89; and P=0.004, log rank, 8.1, respectively). CONCLUSION: Non-viable myocardium revealed with PET predicts mid-term clinical prognosis. Insulin resistance seems to influence the outcome.     

MRA在周围软组织血管瘤和血管畸形中的应用

目的探讨MRA在周围软组织血管瘤和血管畸形中的应用价值。方法回顾性分析61例血管瘤和血管畸形动脉、静脉磁共振血管成像表现。结果13例血管瘤中7例病灶内出现增多且逐渐变细的细小动脉,2例合并有动-静脉瘘形成,6例病灶内未见血管显示。48例血管畸形中35例病变区动、静脉显影,1例仅见动脉显影。动脉成像23例表现为动脉受压变细,5例可见动脉畸形。静脉成像25例显示浅静脉畸形,其中13例合并深静脉畸形,2例仅显示深、浅静脉增多、增粗。8例动、静脉成像均可见动-静脉瘘形成。12例病变区未见血管显影。结论MRA对周围软组织血管瘤和血管畸形的诊断和鉴别有重要价值。     

Number of samples - hypothesis testing

This note reviews "further discussions on choosing the number of animals for an experiment". Particular emphasis will be given to the table therein.     

Peripheral nerve tumors of the orbit

Neurofibromas and schwannomas are orbital neoplasms with similar clinical and radiologic features. Solitary or circumscribed neurofibromas and schwannomas demonstrate slow progressive growth with ocular displacement and are amenable to surgical resection. Plexiform and diffuse neurofibromas are diffusely infiltrative in the orbit and periocular region, they are difficult to resect, and they have a high rate of recurrence. Malignant peripheral nerve tumors are rare, but they have a very high rate of recurrence and a low 5-year survival rate because of extension through the superior orbital fissure to the midbrain region. This article describes the clinical and radiologic features of peripheral nerve sheath tumors.     

Peripheral sympathetic dysfunction in patients with Parkinson's disease without autonomic failure is heart selective and disease specific. taki@med.kanazawa-u.ac.jp

The study was undertaken to investigate by means of iodine-123-labelled metaiodobenzylguanidine (MIBG) scintigraphy the peripheral sympathetic function in patients with Parkinson's disease (PD) without autonomic failure and in patients with related neurodegenerative diseases with parkinsonism. Seventy patients (33 men and 37 women, mean age 63+/-9.7 years) with parkinsonism and ten control subjects underwent MIBG scintigraphy. Of these 70 patients, 41 were diagnosed as having idiopathic PD, 9 multiple system atrophy (MSA), 6 progressive supranuclear palsy (PSP) and 2 corticobasal degeneration (CBD); the remaining 12 were diagnosed as having neurodegenerative disease with parkinsonism (P-nism) that did not meet the diagnostic criteria of any specific disease. Cardiac planar and tomographic imaging studies and subsequent whole-body imaging were performed 20 min and 3 h after the injection of 111 MBq MIBG. The early MIBG heart to mediastinum (H/M) ratio in PD (1.61+/-0.29) was significantly lower than that in the control group (2.24+/-0.14, P<0.01), P-nism (2.15+/-0.31, P<0.01), MSA (2.08+/-0.31, P<0.05) and PSP (2.30+/-0.24, P<0.01). The delayed H/M ratio in PD (1.47+/-0.34) was also significantly lower than that in the control group (2.37+/-0.14, P<0.01), P-nism (2.13+/-0.38, P<0.01), PSP (2.36+/-0.36, P<0.01) and MSA (2.17+/-0.36, P<0.01). In patients with PD, early and delayed H/M ratios were significantly decreased in disease stages I, II and III (established using the Hoehn and Yahr criteria) as compared with control subjects, and there were no significant differences among the stages. Only PD showed a significantly higher washout rate (WR) than that in the control subjects (27%+/-8.0% vs. 11%+/-4.2%, P<0.01). Early and delayed uptake ratios of the lung, parotid gland, thyroid gland, liver and femoral muscles in each of the patient groups were not significantly different from those in control subjects. Only the early and delayed uptake ratios of the lower leg muscles in MSA were significantly lower than those in the control group (P<0.05). IN CONCLUSION: In patients with PD without autonomic failure, only cardiac MIBG uptake was severely reduced in the earliest phase of the disease (stage I). Parkinsonian syndromes other than PD did not demonstrate significant reduction in MIBG uptake in any organs except for the lower legs in MSA. In patients with PD without autonomic failure, reduction in MIBG uptake occurs selectively in the heart; this is considered to be a specific finding for PD and useful for the differential diagnosis of the parkinsonian syndromes.     

Peripheral MR Angiography of Klippel-Trenaunay Syndrome

Klippel-Trenaunay syndrome (KTS) is a rare congenital vascular disease of unknown etiology that affects one or more limbs. It is characterized clinically by three physical findings (the so-called triad): port-wine stain hemangioma, hypertrophy of the bony and/or soft tissue, and varicose veins. A review of the medical literature in 1999 revealed about 1,000 case studies. We present here the case of a patient with clinical diagnosis of KTS studied using peripheral magnetic resonance angiography.