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Time harmonic elastography is introduced as a modality for assessing myocardial elasticity changes during the cardiac cycle. It is based on external stimulation and real-time analysis of 30-Hz harmonic shear waves in axial direction of a parasternal line of sight through the lateral heart wall. In 20 healthy volunteers, the externally induced waves showed smaller amplitudes during systole (76.0 ± 30.8 μm) and higher amplitudes during diastole (126.7 ± 52.1 μm). This periodic wave amplitude alteration preceded ventricular contraction and dilation by about 100 ms. The amplitude ratio of 1.75 ± 0.49 indicates a relative change in myocardial shear elasticity on the order of 14 ± 11. These results well agree with observations made by cardiac magnetic resonance elastography for a similar displacement component and region of the heart. The proposed method provides reproducible elastodynamic information on the heart in real-time and may help in diagnosing myocardial relaxation abnormalities in the future.  相似文献   

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Reported here are the results of an experimental study on the response to low-intensity cavitation induced by low-frequency (4–6 W/cm2, 20 kHz and 32.6 kHz) ultrasound of isolated human arterial samples taken during conventional myocardial revascularization operations. Studies have found that low-frequency ultrasound results in a significant (48%–54%) increase in isometric contraction force and does not depend on the number of exposures (10 or 20) or the time passed since the start of ultrasound (0, 10 and 20 min), but does depend on the frequency and location (internal or external) of the blood vessels for the application of ultrasound. Diltiazem (an inhibitor of slow calcium channels) and carbachol (an agonist of muscarinic receptors) used in a concentration-dependent manner did not modify the relaxation dynamics of smooth muscle affected by ultrasound. Thus, ultrasound conditioned to the augmentation of the isometric contraction force the smooth muscle of blood vessels and did not improve endothelial- and calcium channel blocker-dependent relaxation.  相似文献   

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This study investigates the enhancement effects of iodized oil and the features of hyperechoic focus changes in a target region of high-intensity focused ultrasound (HIFU) ablated uterine fibroids. Leiomyomas in the experimental group of 20 randomly assigned patients were ablated by HIFU under certain parameters 30 min after 1 mL of iodized oil was injected into the center of the myomas. The value of the gray scale and its area were observed by B-mode ultrasound in the target region and were carefully recorded at 0, 2, 4, and 5 min, respectively, after HIFU ablation. The samples were sectioned successively in a thickness of 1~2 mm and stained by 2,3,5-triphenyltetrazolium chloride solution within 1 h after HIFU ablation. The TTC non-staining volumes were measured afterwards. All procedures in the control group of the other 20 randomly assigned patients were the same except that iodized oil was replaced by physiologic saline. The hyperechoic areas in the target region were observed in all fibroids of both groups. Compared with the control group, the gray scale values in the target region of the experimental group were higher 4 min after HIFU ablation. The enhanced gray scale area in the target region and the 2,3,5-triphenyltetrazolium chloride non-staining volumes in the experimental group were bigger. Based on our experience, HIFU sonication of leiomyomas injected with iodized oil produces hyperechoic foci that are greater than areas injected with saline. More studies are required to understand the clinical implications of these observations.  相似文献   

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The dynamics of coated microbubbles was studied in an in vivo model. Biotinylated lipid-coated microbubbles were prepared in-house and were injected into a chick embryo chorioallantoic membrane (CAM) model on the fifth day of incubation. The microbubbles, ranging between 1.0 and 3.5 μm in diameter, were insonified in the frequency range of 4–7 MHz. Two amplitudes of acoustic pressure were applied: 300 kPa and 400 kPa. The fundamental and subharmonic responses were recorded optically with an ultra-fast camera (Brandaris 128) at 20 million frames per second. A subharmonic response was observed for 44% of the studied bubbles. From the data the frequency of the maximum fundamental and subharmonic response was derived for each individual bubble and resulted in the resonance curves of the microbubbles. All the bubbles showed shell (strain) hardening behavior for a higher acoustic pressure. We conclude that the subharmonic oscillations observed in this study belonged to the transmit at resonance (TR) regime.  相似文献   

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The activities of various antibiotics against 58 clinical isolates of Legionella species were evaluated using two methods, extracellular activity (minimum inhibitory concentration [MIC]) and intracellular activity. Susceptibility testing was performed using BSYEα agar. The minimum extracellular concentration inhibiting intracellular multiplication (MIEC) was determined using a human monocyte-derived cell line, THP-1. The most potent drugs in terms of MICs against clinical isolates were levofloxacin, garenoxacin, and rifampicin with MIC90 values of 0.015 μg/ml. The activities of ciprofloxacin, pazufloxacin, moxifloxacin, clarithromycin, and azithromycin were slightly higher than those of levofloxacin, garenoxacin, and rifampicin with an MIC90 of 0.03–0.06 μg/ml. Minocycline showed the highest activity, with an MIC90 of 1 μg/ml. No resistance against the antibiotics tested was detected. No difference was detected in the MIC distributions of the antibiotics tested between L. pneumophila serogroup 1 and L. pneumophila non-serogroup 1. The MIECs of ciprofloxacin, pazufloxacin, levofloxacin, moxifloxacin, garenoxacin, clarithromycin, and azithromycin were almost the same as their MICs, with MIEC90 values of 0.015–0.06 μg/ml, although the MIEC of minocycline was relatively lower and that of rifampicin was higher than their respective MICs. No difference was detected in the MIEC distributions of the antibiotics tested between L. pneumophila serogroup 1 and L. pneumophila non-serogroup 1. The ratios of MIEC:MIC for rifampicin (8) and pazufloxacin (2) were higher than those for levofloxacin (1), ciprofloxacin (1), moxifloxacin (1), garenoxacin (1), clarithromycin (1), and azithromycin (1). Our study showed that quinolones and macrolides had potent antimicrobial activity against both extracellular and intracellular Legionella species. The present data suggested the possible efficacy of these drugs in treatment of Legionella infections.  相似文献   

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Background and objectives

Trauma patients often suffer from persisting pain even years after injury, and data on long-term pain management is lacking. The aim of this study was to evaluate the frequency of persisting pain and health-related quality of life (HrQoL) among trauma victims 2 years after injury. Furthermore, the frequency of pain specialist consultation and the quality of outpatient pain management, including phamacological management, was assessed.

Materials and methods

We analyzed prospectively collected data on severely injured adult patients treated between 2008–2011 at the Cologne Merheim Medical Center (CMMC)/Germany.  Data included the ‘Polytrauma Outcome Profile’ and a standardized questionnaire on outpatient pain management. Exclusion criteria were death, inability to answer the questionnaire due to cognitive disabilities and lack of language knowledge.

Results and conclusions

207/391 (53?%) data sets were available for analysis, presenting a typical trauma collective with injury severity of ISS 19, predominantly male and a mean age of 44 years. 2 years after trauma 59?% still reported that they suffered from severe persisting pain; 53?% of these patients were under pharmacological pain medication. Only 1/5 of the patients with severe persisting pain was treated by a pain specialist. Successful treatment options do exist; improvement of treatment is required.
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Background

The labrum is a biomechanically important structure of the hip joint. In the event of labral loss the new technique of labral reconstruction is aimed at restoring the anatomy and function of the labrum and thus prevention of joint degeneration.

Objective

The results and evidence relating to labral reconstruction are presented.

Material and methods

The currently available studies were evaluated and the biomechanical and clinical articles on labral reconstruction are discussed.

Results

There are a large number of different indications and surgical variants of this procedure. Biomechanical and clinical studies concerning labral defects show that the situation is improved by a reconstruction.

Discussion

As a result of the small number of cases and the low quality of the publications, there is as yet a lack of clinical evidence concerning this new surgical method. The biomechanical results suggest that reconstruction of a segmental labral defect is plausible for selected cases. Initial clinical results have to be confirmed by further studies in the long term.
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OBJECTIVE: To examine the effect of intratracheal heparin instillation on Legionella pneumophila-related acute lung injury (ALI) and systemic dissemination. DESIGN: Prospective, controlled experimental study. SETTING: University research laboratory. INTERVENTIONS: A/J mice received 5[Symbol: see text]mug of sulfated heparin intratracheally co-instilled with 10(6) or 10(8) colony-forming units (CFU) of a virulent isolate of L. pneumophila. MEASUREMENTS AND RESULTS: ALI was assessed in control groups (PBS and PBS-heparin) and on days 1, 2 and 3 post-infection, in terms of the lung wet-to-dry (W/D) weight ratios and of lung endothelial permeability to radio-labeled albumin (Perm-I(125)). Lung bacterial loads were measured and systemic spread was assessed by blood and target organ culture. The alveolar inflammatory response was evaluated by measuring the cytokine levels (TNF-alpha, IFN-gamma, IL-6 and IL-12p70) in bronchoalveolar lavage fluids (BALF). Co-instilled heparin improved mouse survival after the 10(8) CFU challenge (p[Symbol: see text]<[Symbol: see text]0.01). On day 2, heparin co-instillation significantly reduced the W/D ratio and Perm-I(125) (p[Symbol: see text]<[Symbol: see text]0.01 and p[Symbol: see text]<[Symbol: see text]0.001 respectively), improved lung bacterial clearance (p[Symbol: see text]<[Symbol: see text]0.001), prevented systemic dissemination (blood, liver, spleen, kidneys and brain cultures, all p[Symbol: see text]<[Symbol: see text]0.05) and significantly increased IFN-gamma and IL-12p70 levels in BALF (p[Symbol: see text]<[Symbol: see text]0.05). CONCLUSIONS: Heparin co-instillation during intratracheal L. pneumophila challenge has a protective effect on the alveolar-capillary barrier and prevents bacterial dissemination. These results tend to confirm the competitive inhibition by heparin of L. pneumophila attachment to lung epithelium in vivo, and point to the possible involvement of a heparan-sulfate adhesin in L. pneumophila binding to pneumocytes.  相似文献   

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By virtue of specific diagnostic workup, manual medicine is capable of identifying functional disorders early and avoiding future structural dysfunctions. In addition to supervised preventive exercises, patients can also perform exercises independently, during their daily routine at work or at home. This article presents the “Active from Head to Toe” prevention program. Specific target-oriented exercises were selected and combined under consideration of manual medical aspects as well as our experiences in manual therapy. Activation of core stability forms the basis of all exercises. This simultaneously stimulates body awareness as well as concentration and relaxation. Via repeated referral to this central concept during the program, the goal of automized behavior is pursued.  相似文献   

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