Experimental gene therapy is a promising strategy to prevent ischemia-reperfusion (I/R) injury and allograft rejection after lung transplantation, and methods will eventually be needed to characterize pulmonary transgene expression in vivo in humans. Therefore, we studied positron emission tomography (PET) as a means of performing in vivo molecular imaging in rodent models of lung transplantation. Rats were transfected endotracheally with adenovirus encoding a fusion gene of a mutant Herpes simplex virus-1 thymidine kinase and the green fluorescent protein gene (the former serving as an imaging reporter gene). Twenty-four hours after transfection, lungs were transplanted in groups representing normal transplantation, I/R injury and acute allograft rejection. Imaging was obtained either 24 h after transplantation to study reperfusion injury or 4 days after transplantation to study graft rejection. After imaging, lungs were excised and analyzed for thymidine kinase activity. Imaging detected transgene expression in transplanted lungs even in the presence of acute rejection or I/R injury. The PET imaging signal correlated with in vitro lung tissue assays of thymidine kinase activity (r(2) = 0.534). Thus, noninvasive molecular imaging with PET is a feasible, sensitive and quantitative method for characterizing pulmonary transgene expression in experimental lung transplantation. 相似文献
For patients suffering of recurrent breast cancer within the irradiated breast, generally mastectomy is recommended. The normal
tissue tolerance does not permit a second full-dose course of radiotherapy to the entire breast after a second breast-conserving
surgery (BCS). A novel option is to treat these patients with partial breast irradiation (PBI). This approach is based on
the hypothesis that re-irradiation of a limited volume will be effective and result in an acceptable frequency of side effects.
The following report presents a single center experience with intraoperative radiotherapy (IORT) during excision of recurrent
breast cancer in the previously irradiated breast. 相似文献
We tested the hypothesis that bone mineral density (BMD) and bone mineral content (BMC) in proximal human femur specimens in the upper neck region of interest (ROI) and femoral neck axis length (FNAL) provide a significantly better prediction of femoral bone strength than standard ROIs in vitro. BMD and BMC were measured in 110 proximal femur specimens using a standard dual-energy X-ray absorptiometry (DXA) scanner. The analysis included a new ROI in the upper neck as well as the standard ROIs. FNAL was obtained from the scan images. The specimens' failure-load was measured in a mechanical loading device, simulating a fall on the greater trochanter. For the standard ROIs, correlations between failure-load and BMD ranged from R2 = 0.64 (shaft ROI) to R2 = 0.70, p < 0.001 (femoral neck). Prediction of strength by BMD did not significantly differ from those of BMC (R2 ranging from 0.65 to 0.75, p < 0.001). In the upper neck ROI, for both BMD and BMC correlations with failure-load were higher (R2 = 0.76 and 0.81, respectively; p < 0.001). A lower, yet still significant, correlation was found between FNAL and bone strength (R2 = 0.23, p < 0.001). Normalization of failure-load with respect to FNAL did not significantly increase the correlations with densitometric measures. This study provides in vitro evidence indicating that among the ROIs of the proximal femur the newly defined upper neck ROI provides the best prediction of bone strength. Only a weak association was observed between failure load and FNAL. 相似文献
Using 2D and M-Mode transesophageal short axis cross sections, right ventricular systolic wall motion was quantified in 15 normal patients. A further group of 39 patients with right ventricular infarction was investigated. In the normal group fractional shortening of the septum was -19.6% (-45 to 8%), that of the lateral wall 51.6% (37 to 73%), of the posterior wall 33.9% (5 to 50%) and of the anterior wall 42.7% (18 to 57%). Right ventricular infarction (RVI) was associated in 33 patients with posterior left ventricular infarction (85%) and in three patients with anterior infarction. In two cases only an isolated RVI was found. Right ventricular dilation occurred in 24 patients (61%). Hemodynamic criteria were fulfilled in eleven out of 21 patients (53%). RVI was confirmed in one patient by surgery and in ten patients by autopsy. Recognition of regional wall motion abnormalities by transesophageal echocardiography permits an accurate bedside identification of RVI. 2D and M-Mode registration of the short axis improves RVI assessment. Wall motion analyses offer the possibility to determine the extent of right ventricular infarction. 相似文献
Single-agent chemotherapy of metastatic breast cancer is the treatment of choice in patients with slow tumor progression and asymptomatic disease. In this patient group, the choice of drugs is based more on good tolerability than on efficacy. By contrast, symptomatic or rapidly progressing disease requires the use of highly active regimens where more weight is put on reliable antitumor activity. While anthraycline-based combination regimens have set the standard of effective treatment, the addition of docetaxel (and to a lesser extent paclitaxel) has improved tumor response, but failed to induce a consistent prolongation of survival. Based on retrospective analyses, it is hypothesised that the combined use of anthracyclines and taxanes in first-line therapy may be most beneficial in defined subgroups: after adjuvant chemotherapy, in patients with HER-2 gene amplification, possibly also in patients with rapidly progressing visceral disease. 相似文献
Background: Percutaneous cricothyroidotomy is a lifesaving procedure for airway obstruction in trauma victims who need airway establishment and cannot be intubated or in whom intubation has failed.
Methods: The purpose of this study was to examine whether there is a training effect using Seldinger technique emergency cricothyroidotomy (group 1; Arndt Emergency Cricothyroidotomy Catheter Set; Cook Critical Care, Bloomington, IN) versus standard surgical cricothyroidotomy (group 2). Twenty emergency physicians performed five cricothyroidotomies with each method in a total of 200 human cadavers, comparing efficacy and safety (speed, success rate, and injuries).
Results: Seven attempts in group 1 and six in group 2 had to be aborted. Time intervals from the start of the procedure to location of the cricothyroid membrane were not significantly different between the groups. However, time to tracheal puncture (P < 0.01) and time to first ventilation (P < 0.001) were significantly longer in group 2. No time effect could be observed in both groups. The airway was accurately placed into the trachea through the cricothyroid membrane in 88.2% (82 of 93) of the cadavers in group 1 and in 84.0% (79 of 94) in group 2 (not significant). No injuries were observed in group 1, whereas there were six punctures of the thyroid vessels in group 2 (P < 0.05). 相似文献
Abstract Kyphoplasty and vertebroplasty have become recognized procedures for the treatment of vertebral fractures, especially in patients
with osteoporosis. In most cases of osteoporotic spinal vertebral fracture in elderly patients, polymethylmethacrylate (PMMA)
cement is used to fill the defect and stabilize the vertebral body. The techniques of vertebroplasty and kyphoplasty differ
in the possibility of realignment and reconstruction of the vertebral body and spinal column. Long-term results in terms of
integration of the cement and bioreactivity of the vertebral body are still lacking; so, these procedures are still no options
in the treatment of younger patients. Vertebroplasty and kyphoplasty show different success in the management of fresh traumatic
spine fractures. The acute traumatic vertebral fracture has to be classified sensitively, to find the right indication for
cement augmentation. Mild acute compression fractures can be treated by vertebroplasty or kyphoplasty, severe compression
and burst fractures by combination of internal fixation and kyphoplasty. The indications for use of biological or osteoinductive
cement in spinal fracture management must still be regarded as restricted owing to the lack of basic biomechanical research
data. Such cement should not be used except in clinical studies. 相似文献
A major difficulty in the measurement of carbon dioxide diffusing capacity is the development of significant CO2 back pressure within the capillary. The use of oxygen-labeled CO2 limits this back pressure due to rapid dilution of the label into the water pool by isotopic exchange. We demonstrated the use of C16O18O to measure DCO2 (Schuster, 1985). A major question from that study is whether the isotope measures a true membrane diffusing capacity or is limited by back reaction. In this study we examine the diffusing capacity of doubly 18O-labeled carbon dioxide, C18O2, a species in which the kinetics of isotopic exchange in pulmonary blood is higher than that of C16O18O. Eighteen single breath experiments were performed on two resting male subjects whose CO2-transfer-kinetics was previously studied with C16O18O (Schuster, 1985). Following expiration to residual volume the subjects inspired a gas mixture containing 20% O2 and 1.5-2.6% C18O2. After holding their breath for 0.4-17 sec they exhaled into a tube and the end-expired gas was analysed by mass spectrometry. The time course of the C18O2 disappearance from alveolar gas showed a biexponential characteristic as that which had been measured with C16O18O, but C18O2 disappeared faster. The mean value of the diffusing capacity of C18O2 amounts to 1102 ml mmHg-1 X min-1. It is 228 +/- 163 ml mmHg-1 X min-1 greater than that of C16O18O. This significant difference suggests that: DC16O18O is limited in part by isotopic exchange reactions; the observed DC18O2 may be taken as a new lower limit for DMCO2, higher than values established from other techniques; the decarboxylation of bicarbonate in red cells is not a rate limiting step for CO2 exchange. 相似文献