Can relaxation lower metaboreflex-mediated blood pressure elevations?

PURPOSE: Relaxation can lower resting blood pressure, and this investigation sought to determine whether relaxation could reduce mean blood pressure (MBP) elevations produced by postexercise circulatory occlusion (PECO). METHODS: Sixteen volunteers trained with relaxation and were able to decrease MBP at rest by at least 5 mm Hg within 2 min. Subjects performed four tests assigned randomly: i). rest with cuff occlusion, ii). rest and cuff occlusion with relaxation, iii). hand-grip exercise followed by PECO rest with cuff occlusion, and iv) hand-grip exercise followed by PECO with relaxation. Data for HR and MBP were collected using a Finapres; ratings of relaxation and discomfort from cuff occlusion were obtained using a 1- to 10-unit scale. Stroke volume (SV) and HR were collected from six subjects to calculate cardiac output and total peripheral conductance (TPC). Dependent variables were compared using an ANOVA. RESULTS: HR (mean +/-SD) was lower during both relaxation conditions as compared with control (-7 +/- 4 bpm vs -2 +/- 3 bpm; P< 0.05). The MBP was reduced during relaxation alone (-6 +/- 3.7 mm Hg; < 0.05) but not during PECO with relaxation. The rating of relaxation was higher during relaxation (6.8 +/- 1.3 units) versus control (3.5 +/- 1.2 units), but ratings were not different between relaxation conditions. Ratings of discomfort were higher during PECO ( P< 0.05). Relaxation did not significantly alter CO or SV (N= 6). During relaxation alone, TPC was increased (0.046 +/- 0.001 vs 0.049 +/- 0.002 L.min.mm Hg; P< 0.05). However, TPC was significantly increased during PECO with relaxation. CONCLUSIONS: These findings suggest that although relaxation can affect cardiovascular regulation and lower HR and MBP at rest, this central signal cannot lower reflex increases in blood pressure originating from a peripheral metabolic stimulus.     

Intra and intersession repeatability and reliability of the S-Plate® pressure platform

AimThe aim of this study was to assess the repeatability and reliability of the S-Plate® pressure platform in a group of healthy subjects.Material and methodsForty subjects, free from physical conditions that would affect normal gait, walked along a five-meter corridor while data were recorded from the pressure platform. A total of 10 steps (five each side) were obtained as well as five static trials; the same measurements were repeated one week later. Peak and mean plantar pressures and contact area were recorded for both dynamic and static trials. Additionally, weight supported on each limb was documented during static trials. To assess intrasession and intersession repeatability and reliability, the intraclass correlation coefficients (ICCs) and coefficient of variation (CoV) were calculated.ResultsTaking the ICC values into account, every static and dynamic variable analysed showed moderate to excellent reliability and the CoV values were all below 12%.ConclusionMeasurements of either static or dynamic plantar pressure variables with the S-Plate® pressure platform show good repeatability and reliability, and so it is useful for comparing steps within and between sessions.     

Trunk sway in idiopathic normal pressure hydrocephalus—Quantitative assessment in clinical practice

BackgroundIn diagnosis and treatment of patients with idiopathic normal pressure hydrocephalus (iNPH), there is need for clinically applicable, quantitative assessment of balance and gait. Using a body-worn gyroscopic system, the aim of this study was to assess postural stability of iNPH patients in standing, walking and during sensory deprivation before and after cerebrospinal fluid (CSF) drainage and surgery. A comparison was performed between healthy elderly (HE) and patients with various types of hydrocephalus (ventriculomegaly (VM)).MethodsTrunk sway was measured in 31 iNPH patients, 22 VM patients and 58 HE. Measurements were performed at baseline in all subjects, after CSF drainage in both patient groups and after shunt surgery in the iNPH group.ResultsPreoperatively, the iNPH patients had significantly higher trunk sway compared to HE, specifically for the standing tasks (p < 0.001). Compared to VM, iNPH patients had significantly lower sway velocity during gait in three of four cases on firm support (p < 0.05). Sway velocity improved after CSF drainage and in forward-backward direction after surgery (p < 0.01). Compared to HE both patient groups demonstrated less reliance on visual input to maintain stable posture.ConclusionsINPH patients had reduced postural stability compared to HE, particularly during standing, and for differentiation between iNPH and VM patients sway velocity during gait is a promising parameter. A reversible reduction of visual incorporation during standing was also seen. Thus, the gyroscopic system quantitatively assessed postural deficits in iNPH, making it a potentially useful tool for aiding in future diagnoses, choices of treatment and clinical follow-up.     

Prefraction displacement and intrafraction drift of the prostate due to perineal ultrasound probe pressure

Objective

In image-guided EBRT of the prostate, transperineal ultrasound (US) probes exert pressure on the perineum both during planning and treatment. Through tissue deformation and relaxation, this causes target and risk organ displacement and drift. In this study, prefraction shift and intrafraction drift of the prostate are quantified during robotic transperineal 4DUS.

Methods

The position of the prostate was recorded for different positions of the probe before treatment in 10 patients (16 series of measurements). During treatment (15 patients, 273 fractions), intrafraction motion of the prostate was tracked (total of 27?h and 24?min) with the transperineal probe in place.

Results

Per 1?mm shift of the US probe in the cranial direction, a displacement of the prostate by 0.42 ± 0.09?mm in the cranial direction was detected. The relationship was found to be linear (R² = 0.97) and highly significant (p < 0.0001). After initial contact of the probe and the perineum (no pressure), a shift of the probe of about 5–10?mm was typically necessary to achieve good image quality, corresponding to a shift of the prostate of about 2–4?mm in the cranial direction. Tissue compression and prostate displacement were well visible. During treatment, the prostate drifted at an average rate of 0.075?mm/min in the cranial direction (p = 0.0014).

Conclusion

The pressure applied by a perineal US probe has a quantitatively similar impact on prostate displacement as transabdominal pressure. Shifts are predominantly in the cranial direction (typically 2–4?mm) with some component in the anterior direction (typically <1?mm). Slight probe pressure can improve image quality, but excessive probe pressure can distort the surrounding anatomy and potentially move risk organs closer to the high-dose area.

     

Are in-shoe pressure characteristics in symptomatic idiopathic pes cavus related to the location of foot pain?

People who have extremely high arched feet may be subject to substantial levels of foot pain, despite the lack of obvious pathology. This study sought to investigate the effect of pes cavus on pain intensity and location and on the magnitude and distribution of foot pressure. Measurements were derived from the more symptomatic foot of 130 participants with painful, idiopathic pes cavus. Data were collected using Pedar in-shoe pressure sensors and averaged over nine randomly selected steps. Participant information, including location and intensity of pain, Foot Posture Index values and anthropometric and "quality of life" variables, were also recorded. Painful idiopathic pes cavus seems to provoke a more cautious gait pattern than normal, with reduced peak and mean pressure values, particularly in the fore- and rear-foot regions. In particular, participants with pain confined to the rear-foot exhibit an antalgic gait pattern, with lower pressure values and a longer period of foot-ground contact in the heel region than those with pain only in the fore-foot. We determined no clear predictors of pain in terms of foot posture or demographics, although people with high body mass index values are more likely to have pain in several regions. The relationship between the posture of the foot and the presentation of pain remains unclear, however we believe that the presence of heel pain in pes cavus may be more restricting than fore-foot pain.     

Pattern description and reliability parameters of six force–time related indices measured with plantar pressure measurements

BackgroundFunctional interpretation of plantar pressure measurements is commonly done through the use of ratios and indices which are preceded by the strategic combination of a subsampling method and selection of physical quantities. However, errors which may arise throughout the determination of these temporal indices/ratio calculations (T-IRC) have not been quantified. The purpose of the current study was therefore to estimate the reliability of T-IRC following semi-automatic total mapping (SATM).MethodsUsing a repeated-measures design, two experienced therapists performed three subsampling sessions on three left and right pedobarographic footprints of ten healthy participants. Following the subsampling, six T-IRC were calculated: Rearfoot-Forefoot_fti, Rearfoot-Midfoot_fti, Forefoot medial/lateral_fti, First ray_fti, Metatarsal 1-Metatarsal 5_fti, Foot medial-lateral_fti.FindingsPatterns of the T-IRC were found to be consistent and in good agreement with corresponding knowledge from the literature. The inter-session errors of both therapists were similar in pattern and magnitude. The lowest peak inter-therapist error was found in the First ray_fti (6.5 a.u.) whereas the highest peak inter-therapist error was observed in the Forefoot medial/lateral_fti (27.0 a.u.) The magnitude of the inter-session and inter-therapist error varied over time, precluding the calculation of a simple numerical value for the error. The difference between both error parameters of all T-IRC was negligible which underscores the repeatability of the SATM protocol.ConclusionThe current study reports consistent patterns for six T-IRC and similar inter-session and inter-therapist error. The proposed SATM protocol and the T-IRC may therefore serve as basis for functional interpretation of footprint data.     

Tendon–bone contact pressure and biomechanical evaluation of a modified suture-bridge technique for rotator cuff repair

The aim of the study was to evaluate the time-zero mechanical and footprint properties of a suture-bridge technique for rotator cuff repair in an animal model. Thirty fresh-frozen sheep shoulders were randomly assigned among three investigation groups: (1) cyclic loading, (2) load-to-failure testing, and (3) tendon–bone interface contact pressure measurement. Shoulders were cyclically loaded from 10 to 180 N and displacement to gap formation of 5- and 10-mm at the repair site. Cycles to failure were determined. Additionally, the ultimate tensile strength and stiffness were verified along with the mode of failure. The average contact pressure and pressure pattern were investigated using a pressure-sensitive film system. All of the specimens resisted against 3,000 cycles and none of them reached a gap formation of 10 mm. The number of cycles to 5-mm gap formation was 2,884.5 ± 96.8 cycles. The ultimate tensile strength was 565.8 ± 17.8 N and stiffness was 173.7 ± 9.9 N/mm. The entire specimen presented a unique mode of failure as it is well known in using high strength sutures by pulling them through the tendon. We observed a mean contact pressure of 1.19 ± 0.03 MPa, applied on the footprint area. The fundamental results of our study support the use of a suture-bridge technique for optimising the conditions of the healing biology of a reconstructed rotator cuff tendon. Nevertheless, an individual estimation has to be done if using the suture-bridge technique clinically. Further investigation is necessary to evaluate the cell biological healing process in order to achieve further sufficient advancements in rotator cuff repair.     

百花齐放,百家争鸣,审时度势,再接再励

玉兔离去,祥龙驾临,又一个欣欣向荣的美好日子呈现在我们的面前.回首往事,感慨万千,《医学影像学杂志》经历了许多,得到了很多,有奋斗就有成果,有劳作就有喜悦,这些成果、喜悦无不得益于全体医学影像学杂志编委们的无私奉献,欣欣关怀,无不得益于广大读者、作者的支持,您的每一个观点,一个建议,一个邮件,一个电话传递的是关怀,是希望,是对杂志发展的鞭策.在这里,我代表全体编辑部的同志们向您们表示衷心的感谢和敬意.     

The cutting edge—an investigation into the pressure necessary for cutting skin with different knife blade types

International Journal of Legal Medicine - Sharp force trauma is routinely encountered in forensic practice. Often the question is posed, how much pressure or energy would have been necessary to...     

Effect of continuous positive airway pressure administration during lung stereotactic ablative radiotherapy: a comparative planning study

Purpose

By increasing lung volume and decreasing respiration-induced tumour motion amplitude, administration of continuous positive airway pressure (CPAP) during stereotactic ablative radiotherapy (SABR) could allow for better sparing of the lungs and heart. In this study, we evaluated the effect of CPAP on lung volume, tumour motion amplitude and baseline shift, as well as the dosimetric impact of the strategy.

Methods

Twenty patients with lung tumours referred for SABR underwent 4D-computed tomography (CT) scans with and without CPAP (CPAP/noCPAP) at two timepoints (T0/T1). First, CPAP and noCPAP scans were compared for lung volume, tumour motion amplitude, and baseline shift. Next, CPAP and noCPAP treatment plans were computed and compared for lung dose parameters (mean lung dose (MLD), lung volume receiving 20 Gy (V_20Gy), 13 Gy (V_13Gy), and 5 Gy (V_5Gy)) and mean heart dose (MHD).

Results

On average, CPAP increased lung volume by 8.0% (p?<?0.001) and 6.3% (p?<?0.001) at T0 and T1, respectively, but did not change tumour motion amplitude or baseline shift. As a result, CPAP administration led to an absolute decrease in MLD, lung V_20Gy, V_13Gy and V_5Gy of 0.1?Gy (p?=?0.1), 0.4% (p?=?0.03), 0.5% (p?=?0.04) and 0.5% (p?=?0.2), respectively, while having no significant influence on MHD.

Conclusions

In patients referred for SABR for lung tumours, CPAP increased lung volume without modifying tumour motion or baseline shift. As a result, CPAP allowed for a slight decrease in radiation dose to the lungs, which is unlikely to be clinically significant.

     

Serologie,Blutgruppen, Endokrinologie,Bakteriologie, Immunitätslehre

International Journal of Legal Medicine -     

Serologie,Blutgruppen, Endokrinologie,Bakteriologie, Immunitätslehre

International Journal of Legal Medicine -     

胸闷,恶心,尿少,肾衰

1病历摘要患者，男性，56岁。因胸闷、憋气、乏力、纳差、尿少1个半月，于1995年9月18日入院。缘自8月初起，无任何诱因出现阵发性胸闷憋气，同时还有乏力、恶心、纳差，双下肢水肿，尿量逐渐减少（300～400ml／d）。继之，出现水样便，5～6次／do遂住某医院。该院检查，血尿素氮、肌配增高，B超示双肾积水，膀优镜检查双侧输尿管逆行插管仅进入Icm后即受阻。诊断为梗阻性尿毒症。为进一步明确诊断和进行有效治疗，乃转入我院。既往史无特殊。入院检查：体温36．6”C，脉搏100／min，呼吸18／min，血压工5．0／9．3kPa。发育正常，营养中…     

腹痛,发热,腹部肿块,腹腔积血

1病历摘要患者，男性，43岁，以突发上腹痛1h于1995年11月3O日上午9：00入院。患者lh前突发上腹疼痛，呈持续烧灼样痛，疼痛向左肩背放散。畏寒、发热、恶心、未吐。既往无胃痛、肝胆病及高血压病病史。体格检查：体温38”C，脉搏85／min，血压ZO／12kPa。神志清楚，表情痛苦。皮肤无黄染，全身浅表淋巴结未触及。心肺正常。腹部平坦，无肠型及蠕动波。腹肌紧张，拒按，肝脾下线未满意触及。左中腹部触癌明显，可们及一包块，边界不清。肝法音界存在。腹部有移动性法音，肠鸣音正常。实验室检查：血红蛋白130g／L，红细胞4．47X10‘’／…