ISSN:0894-1939    

DOI:10.3109/08941939309141187

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

摘要:

Peritoneal macrophages and polymorphonuclear neutrophils are key cells in the repair of postoperative injury. Increased numbers of macrophages migrate into the peritoneal cavity after operation and the function of these cells changes over the postoperative interval. Macrophage activities, such as respiratory burst, arachidonic acid metabolism, monokine secretion, and plasminogen activator inhibitory activity, are elevated by peritoneal operation. However, the secretion of plasminogen activator activity is decreased after operation. The kinetics with which each of these functions changes varies with the parameter examined, indicating a complex regulation of the differentiation of leukocytes after operation. In addition, the activity of postoperative macrophages can be modulated in vitro by exposure to cytokines and conditioned media from polymorphonuclear neutrophils and macrophages. Thus, cell-cell interactions and factors secreted within the peritoneal cavity may regulate the contribution of postoperative leukocytes to peritoneal repair after operation.

ISSN:0894-1939    

DOI:10.3109/08941939309141188

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

摘要:

A new system of impedance measurement over a frequency range of 0 to 200 kHz was developed by a three-electrode method. In this study, the electrical impedances of various tumors were measured in vivo in 54 patients with breast disease (31 breast cancers, 13 fibroadenomas, and 10 fibrocystic diseases) and 57 patients with pulmonary disease (44 lung cancers, 5 metastatic pulmonary tumors, 4 pulmonary tuberculoses, and 4 organized pneumonias). On the basis of those impedance measurements and the equivalent circuits in vivo, we calculated the extracellular resistance (Re), intracellular fluid resistance (Ri), and cell membrane capacitance (Cm) in tissues, all of which were compared among the various diseases. It was found that Reand Riwere significantly higher in breast cancers than in benign tumors and normal breast tissues and that Cmwas significantly lower in breast cancers than in other tissues. On the other hand, Reand Riwere significantly higher, and Cmwas significantly lower, in normal lung tissues than in pulmonary masses. Reand Riwere significantly higher, and Cmwas significantly lower, in malignant tumors than in organized pneumonias. The results showed that these parameters (Re, Ri, and Cm) exhibit significant differences among various tissues and tumors, suggesting possible applications in tumor diagnosis.

ISSN:0894-1939    

DOI:10.3109/08941939309141189

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

摘要:

Thermal balloon angioplasty has been proposed as a means of reducing acute and delayed reclosure of arteries after percutaneous transluminal balloon angioplasty. A radiofrequency (rf) balloon catheter was used to perform thermal balloon angioplasty on canine arteries in vivo. The histologic appearance of rf-treated sites was compared with that of control sites treated by conventional percutaneous transluminal angioplasty. Acutely, rf-treated sites showed a reduced medial cellularity with preservation of internal elastic lamina except at the transitional zone between thermal injury and normal artery, where localized internal elastic lamina disruption was found. Nonthermal sites showed generalized disruption of internal elastic lamina and normal medial cellularity. Both thermal and nonthermal sites displayed a return of intimal cover commencing at 1 to 2 weeks and completed by 4 weeks. Diffuse myointimal hyperplasia appeared by 2 weeks after injury at breaks in the internal elastic lamina along the nonthermal vessels but was localized to the transitional zone in thermal injury sites. In rf-treated vessels, repopulation of the acellular thermally modified media had commenced by 4 weeks, and by 8 weeks the media was diffusely repopulated by spindle-shaped cells resembling smooth muscle cells lying between and aligned with preserved connective tissue laminae. Overall, the distribution and extent of the proliferative response after rf thermal balloon angioplasty were less than those seen after nonthermal balloon angioplasty. Thermal sites, which underwent reintimalization before medial cells returned, were considerably less prone to the development of myointimal hyperplasia. These results suggest that this modality may have beneficial effects on arterial healing after angioplasty.

ISSN:0894-1939    

DOI:10.3109/08941939309141190

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

摘要:

Monitoring of urinary enzymuria has been utilized to detect allograft dysfunction after pancreas transplantation with pancreaticocystostomy. In addition, pharmacologic exocrine suppression has been advocated to minimize bicarbonate and protein wasting. Ensuring the validity of these approaches requires controlling both for immunologic alterations in transplant function and for the renal excretion of amylase, bicarbonate, and protein. Toward this end, adult mongrel dogs were divided into two groups. Group A animals underwent distal pancreatectomy alone, and group B animals underwent distal pancreatectomy with autotransplantation and pancreaticocystostomy. In each group, amylase, bicarbonate, and protein output were determined over a 5-hour period in the basal state, during a continuous infusion of octapeptide-cholecystokinin (OP-CCK) at 125 ng/kg/hour, and during a continuous infusion of OP-CCK (125 ng/kg/hour) plus a bolus injection of one clinical unit of secretin per kilogram. Bicarbonate output was not significantly different in the groups with and without autografts. Compared to nonautograft experiments, a statistically significant increase in amylase output was demonstrated in the autograft animals. An increase in protein output was also demonstrated in the autograft experiments, and this increase was statistically significant in the OP-CCK group and the OP-CCK and secretin group. In addition, compared to basal autograft secretion, OP-CCK and OP-CCK plus secretin stimulation resulted in a sustained and significant increase in urinary amylase and protein secretion, indicating preserved sensitivity of the denervated pancreas to exogenous hormones. These results indicate that the canine segmental pancreatic autograft model with pancreaticocystostomy is a suitable model to identify agents associated with exocrine inhibition after transplantation.

ISSN:0894-1939    

DOI:10.3109/08941939309141191

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

摘要:

This report describes an occlusive canine iliac artery model for use in experimental angioplasty procedures. Lesions were induced by overdistending and breaking the internal elastic lamina of the artery and implanting a 2-cm long occlusive collagen plug. The collagen plug diameter was varied to fit the iliac artery and caused immediate bilateral iliac occlusions. Histology of the lesions at 9 and 14 days (n= 2) showed that the lumen was filled with a mixture of fresh thrombus and collagen pad material (more collagen than thrombus) with focal disruptions of the internal elastic lamina. At 36 days (n= 2) the lumen was obliterated with a mixture of organizing thrombus and collagen pad material (more organizing thrombus than collagen). At 60 (n= 4) and 80 (n=8) days the collagen pad had been completely replaced with organizing thrombus consisting of collagen fibers and hemosiderinladen macrophages with persistent focal disruptions of the internal elastic lamina. These initial data demonstrate the ability to create fibrotic arterial occlusions in as short a time as 60 days and to provide a practical model to study methods for treating localized peripheral vascular occlusive disease.

ISSN:0894-1939    

DOI:10.3109/08941939309141192

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

摘要:

Hyperthermia has shown promise as an anticancer therapy, but its application to lung neoplasms has been limited by whole body hyperthermia complications and the intrathoracic location of lung neoplasms. Previous studies have shown that interstitial hyperthermia could be performed through a thoracotomy approach and that animals tolerated the procedure without biochemical or hematologic abnormalities. The normal lung's local blood flow pattern and parenchymal changes due to hyperthermia of various temperatures and durations were studied. The experimental protocol applied hyperthermia through interstitial electrodes at temperatures of 39°, 41°, 43°, and 45°C. Tissue blood flow was measured with radioactive microspheres at 20, 40, and 60 minutes of hyperthermia. Histologic examination was performed of biopsy specimens taken from the heated area, from 2 and 5 cm from the heated area, and from distant parenchyma. These initial studies demonstrate that interstitial hyperthermia in the normal lung does not cause a decrease in pulmonary vascular resistance, that interstitial hyperthermia in the normal lung at temperatures of 43°or 45°C for durations of longer than 20 minutes decreases local pulmonary blood flow, that interstitial hyperthermia causes mild vascular disruption at temperatures of 39°C or greater in the heated area but does not affect adjacent or distant lung parenchyma, and that lung hyperthermia causes generalized vascular disruption with severe widening of the pulmonary interstitium and severe hemorrhage in the heated areas when temperatures of 43°or 45°C are applied. Because interstitial hyperthermia affected only local lung damage, it may be applicable in the treatment of localized lung tumors.

ISSN:0894-1939    

DOI:10.3109/08941939309141193

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

摘要:

The use of saphenous vein in situ bypass for limb salvage has increased the need for adequate visualization of distal lower extremity vessels. Preoperative angiographic techniques are often inadequate, requiring multiple films, extensive patient manipulation, or excessive dye loads. Intraoperative prereconstructive angiography permits adequate distal vessel visualization, but at a significant waste of time and expense if no usable distal vessels are found. There is a need for a reliable means of preoperative angiography in patients being evaluated for saphenous vein in situ bypass. Preoperative balloon occlusion femoral angiography was compared to preoperative standard angiography of the lower extremity in 39 patients referred to the University of Minnesota for limb salvage. Balloon occlusion femoral angiography significantly improved the preoperative ability to visualize lower extremity vessels distal to the superficial femoral artery in this group of patients.

ISSN:0894-1939    

DOI:10.3109/08941939309141194

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

摘要:

Although laser energy in combination with conventional techniques has been used to ablate prostatic tissue in the dog, the use of the Nd:YAG laser alone to perform transurethral prostatectomies has not been feasible because of the difficulty of directing the laser energy into the prostate. In this study, a 600-μm quartz laser fiber with an attached gold-plated metal alloy reflector and a 1.06-μm Nd:YAG laser were used to perform transurethral laser prostatectomies in 10 mongrel dogs. Each dog received approximately 3600 J to each quadrant of the prostate. No signs of urinary incontinence were noted in any of the dogs postoperatively. Transurethral laser prostatectomies can be performed safely and effectively in the dog and can significantly decrease the incidence of postoperative urinary incontinence.

ISSN:0894-1939    

DOI:10.3109/08941939309141195

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

ISSN:0894-1939    

DOI:10.3109/08941939309141185

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor