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61.
A prospective evaluation of color flow mapping and real-time ultrasound was performed to determine if pseudoaneurysms could be distinguished from other causes of masses surrounding vascular grafts of the lower extremities. Twelve palpable pulsatile masses were imaged. Diagnoses were confirmed at angiography (n = 11), computed tomography (n = 7), aspiration biopsy (n = 5), and operative intervention (n = 6). A swirling pattern of blood flow was seen in six of seven cases of pseudoaneurysm. Lack of flow signals was noted in four of the five collections representing hematoma (n = 2) or infection (n = 2). The seventh case was later shown to be an infected, thrombosed pseudoaneurysm. The single false-positive diagnosis was made early in the series when the flow signals detected were due to transmitted arterial pulsations. The authors conclude that color Doppler flow imaging is useful in the differential diagnosis of pulsatile masses associated with prosthetic grafts. Prosthetic graft pseudoaneurysms have a specific appearance of swirling blood flow arising from a wide neck and are distinguishable from traumatic or iatrogenic pseudoaneurysms of the native vascular tree. 相似文献
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Perforation of the inferior vena cava with aortic and vertebral penetration by a suprarenal Greenfield filter 总被引:1,自引:0,他引:1
Various complications have been reported after insertion of the Greenfield filter. This report describes an unusual complication after suprarenal placement of this filter: spreading of the filter struts, with perforation of the inferior vena cava, and penetration of the aorta and a vertebral body, followed by fracture of one of the struts. 相似文献
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L Gunawardhana J Barr A J Weir K Brendel I G Sipes 《Drug metabolism and disposition》1991,19(3):648-654
N-Acetyltransferase (NAT) polymorphism has been implicated in differences in the susceptibility of individuals to the toxicity of chemicals metabolized by this enzyme system. Investigation into the toxicological consequences of acetylator polymorphism and the mechanism of these effects in humans, however, has been greatly hindered due to the lack of a suitable human tissue culture system for determination of hepatic NAT activity and acetylator status of individuals. An in vitro system has been developed to study NAT activity using human liver slices in dynamic organ culture. Acetylation of para-aminobenzoic acid (PABA) and sulfamethazine (SMZ) by human liver slices was monitored by measuring the disappearance of the parent amine from the incubation medium using the colorimetric procedure of Bratton and Marshall. Presence of the acetyl conjugate was confirmed using HPLC. PABA acetylation rates varied from 0.72-2.52 nmol/hr/mg protein (N = 8). This small variation (less than 4-fold) is consistent with the classification of PABA as a monomorphic substrate. The variation in the rate of SMZ acetylation was greater than 20-fold (0.144-3.68 nmol/hr/mg protein; N = 9). This larger variation is characteristic of SMZ as a polymorphic substrate. A good correlation of N-acetylation activities for SMZ was also found between cytosol and slices prepared from the same human livers. The results obtained indicate that human liver slices in dynamic organ culture can be used for the determination of hepatic NAT activity in humans. These slices may be useful in toxicological studies that seek to relate N-acetylation of chemicals in the human liver with potential toxicity. 相似文献
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H Reichenspurner W Ertel B Reichart B M Kemkes S W Jamieson C Hammer W Brendel 《The Journal of surgical research》1986,41(3):301-307
A method of hetero-orthotopic heart-lung transplantation is described in the dog. The model was developed to study patterns of rejection in the transplanted heart and lung, since the dog will not survive bilateral pneumonectomy and loss of the Hering-Breuer reflex. After removal of the recipient's left lung the donor heart and left lung are explanted en bloc. End-to-end connection is made of both left main bronchi, and the donor aorta is joined end-to-side with the recipient's descending aorta. An atrio-atrial anastomosis is performed between the recipient's left and the donor's right atrium. Four experiments were done to develop the surgical technique and 10 long-term studies were performed to investigate rejection patterns. The average survival rate of these animals was 28.5 +/- 8.3 days, ranging from 5 to 53 days. Causes of death were not due to operative complications. Heterotopic heart-lung transplantation is an uncomplicated surgical method which does not require cardiopulmonary bypass or anticoagulation and allows the investigator to study heart and lung grafts in dogs for long-term periods after surgery. Bronchoscopy, bronchoalveolar lavage, and heart and lung biopsies of both donor and recipient organs can be performed. 相似文献
67.
Summary In order to study resistance to DNA damaging agents, yeast DNA segments conferring hyperresistance in this organism to such genotoxic agents were selected for among yeast cells transformed by a yeast genome library based on the multi-copy vector plasmid YEp13. Genetic variants hyperresistant to 4-nitroquinohne-N-oxide, formaldehyde, and alkylating agents were isolated and the respective hyperresistance determinants shown to co-segregate with the vector plasmid. Phenotypical characterization indicated different degrees of resistance, few cases of cross-resistance and differing structural stability of the cloned DNA. By transfer to E. coli and subsequent retransformation of yeast a number of plasmids was shown to stably carry the genetic information for hyperresistance.Dedicated to Prof. Dr. Fritz Kaudewitz on the occasion of his 65th birthday 相似文献
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