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This case report describes a unique manifestation of a primary urethral squamous cell carcinoma (SCC) as the underlying pathology in an 80-year-old male patient who underwent partial penectomy due to an enlarging penile mass. Persistent pain in the right knee was discovered to be a pathologic fracture using magnetic resonance imaging. Computed tomography-guided biopsy confirmed metastatic SCC. Whole-body positron emission tomography revealed systemic dissemination to multiple sites. Orthopedic knee replacement was performed in combination with local radiotherapy. Palliative chemotherapy was rejected due to poor performance status. Primary urethral SCC is rare and an uncommon cause of advanced penile cancer. These findings could be of great interest to clinicians for two reasons. First, a tumor's appearance can be misleading. Consequently, histological work-up in accordance with clinical guidelines is necessary for accurate diagnosis. Second, a more comprehensive investigation is required when clinical symptoms persist despite the use of conventional treatment. Our case is an instance in which persistent pain masked the presence of downstream metastasis. We believe that these aforementioned points are of significant clinical importance and present a salient learning opportunity.

This case report presents a unique manifestation of complications in a 71-year-old man following blunt renal trauma. Initially, computed tomography (CT) revealed a traumatic left kidney laceration. Hematuria ceased quickly after ureteral stent placement. One week later, hematuria reoccurred while the patient was treated for pulmonary embolism. Multiphase CT revealed two renal pseudoaneurysms as the underlying cause. Renal pseudoaneurysms are commonly associated with surgery or inflammation and rarely seen after trauma. Selective angiographic embolization successfully stopped hematuria. Thereafter, the patient was hemodynamically stable to continue therapeutic thrombolysis. After discharge, the patient remained symptom-free and had an unremarkable follow up assessment.

Objectives: Atherosclerosis of iliac arteries is widespread. As inflow vessels, they are of great clinical significance and increasingly being treated by endovascular means. Most commonly, stents are implanted., Background: So far, due to a lack of comparative data, no guideline recommendations on the preferable stent type, balloon-expandable stent (BE) or self-expanding stent (SE), have been issued., Methods: In this randomized, multicenter study, patients with moderate to severe claudication from common or external iliac artery occlusive disease were assigned 1:1 to either BE or SE. The primary endpoint was binary restenosis at 12 months as determined by duplex ultrasound. Key secondary endpoints were walking impairment, freedom from target lesion revascularization (TLR), hemodynamic success, target limb amputation, and all-cause death., Results: Six hundred sixty patients with 660 lesions were enrolled at 18 German and Swiss sites over a period of 34 months; 24.8% of the patients had diabetes and 57.4% were current smokers. The common iliac artery was affected in 58.9%. One hundred nine (16.5%) lesions were totally occluded and 25.6% heavily calcified. Twelve-month incidence of restenosis was 6.1% after SE implantation and 14.9% after BE implantation (p = 0.006). Kaplan-Meier estimate of freedom from TLR was 97.2% and 93.6%, respectively (p = 0.042). There was no between-group difference in walking impairment, hemodynamic success, amputation rate, all-cause death, or periprocedural complications., Conclusions: The treatment of iliac artery occlusive disease with SE as compared with BE resulted in a lower 12-month restenosis rate and a significantly reduced TLR rate. No safety concerns arose in both groups. (Iliac, Common and External [ICE] Artery Stent Trial; NCT01305174)., (Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Purpose: To evaluate the safety and efficacy of the Misago self-expanding rapid-exchange nitinol stent system for the treatment of femoropopliteal occlusive disease in a prospective multicenter observational trial (ClinicalTrials.gov; identifier NCT01118117)., Methods: Between April and October 2008, the registry enrolled 744 patients (496 men; 69 ± 10 years) who had symptomatic ≥ 70% stenosis or occlusion of the superficial femoral or popliteal arteries treated with the Misago stent. Mean length of the 750 lesions was 63.9 mm; 282 (37.6%) vessels were completely occluded. Primary study endpoints were the need for target lesion revascularization (TLR) and event-free survival rates for the assessment of efficacy and safety, respectively. At 6 and 12 months post intervention, clinical symptoms of recurrent ischemia and/or claudication, Rutherford category, and ankle-brachial index (ABI) at rest were assessed., Results: In the study period, 945 stents were successfully deployed in the 750 lesions. The overall TLR rate was 10.1% among 671 (90.3%) patients evaluated at 1 year [3.1% among 709 (95.3%) patients at 6 months]. Event-free survival at 12 months was 84.9%. Mean ABIs improved by ≥ 0.1 in three quarters of the patients (76.0%) over 12 months. The Rutherford grade improved or remained stable in the majority of patients (95.5%) after 1 year. Stent fractures (13 grade 1, 2 grade 2) in 3.1% of stents examined radiographically (n=484) at 1 year were not related to any clinical events. Primary patency was recorded in 574 (87.6%) patients evaluated at 1 year post procedure., Conclusion: The Misago rapid-exchange nitinol stent showed promising efficacy and safety results, with a low stent fracture rate, in patients with femoropopliteal disease, making it a safe and reliable treatment option.

Purpose: To evaluate the long-term efficacy and integrity of the PROTEGE EverFlex stent in superficial femoral artery (SFA) lesions in symptomatic patients with peripheral artery disease (PAD)., Methods: A prospective, multicenter, nonrandomized study enrolled 151 subjects (111 men; mean age 67.8 years, range 42-93) undergoing percutaneous treatment of de novo, restenotic, or reoccluded SFA lesions between August 11, 2006, and June 26, 2007. Subjects were scheduled to receive a single stent and be evaluated through 12 months following the implant procedure. Occlusions were present in 40% of the patients. Mean lesion length was 96.4 mm (range 10-150)., Results: A total of 161 stents (158 EverFlex) were implanted in the 151 patients: single stents in 93.4% (141/151) and a second stent in 6.6% (10/151). One-year follow-up information was available for 88.7% (134/151) of the study participants; of the remaining 17 subjects, 6 subjects withdrew from the study, 2 were lost to follow-up, and 9 died. Freedom from restenosis data were available for 99.3% (133/134) of the subjects who completed a 12-month follow-up visit. The mean Rutherford classification fell from 2.8+/-0.8 (range 1-5) at baseline to 0.6+/-1.1 (range 0-5) at 12 months. The mean ankle-brachial index rose from 0.6+/-0.2 (range 0-1.4) at baseline to 0.9+/-0.2 (range 0-1.2) at 12 months. The rates for freedom from >50% restenosis at 6 and 12 months were 91.3% (95% CI 84.9% to 95.2%) and 72.2% (95% CI 63.8% to 79.6%), respectively. The freedom from target lesion revascularization rate at 12 months was 79.1% (95% CI 71.2% to 85.6%). The 1-year stent fracture rate was 8.1% (95% CI 4.0% to 14.4%)., Conclusion: The high freedom from >50% restenosis and low fracture rate at 12 months suggests that the PROTEGE EverFlex stent offers a safe and acceptably efficacious means of treating SFA lesions in symptomatic subjects with PAD.

Purpose: This prospective study was undertaken to determine the success rate, complications, and outcome of carotid artery stenting (CAS) without the use of cerebral protection devices., Methods: During 12 months, 94 high-grade stenoses of the carotid artery in 91 consecutive patients were treated. Sixty-six (70%) of the stenoses were symptomatic and 28 (30%) were asymptomatic., Results: In all 94 carotid stenoses CAS was successfully performed. During the procedure and within the 30 days afterwards, there were 2 deaths and 3 major strokes in the 66 symptomatic patients, resulting in a combined death and stroke rate of 5 of 66 (7%). Only one of these complications, a major stroke, occurred during the procedure. In the 6-month follow-up, one additional major stroke occurred in a originally symptomatic patient resulting in a combined death and stroke rate of 6 of 66 (10%) for symptomatic patients at 6 months. No major complications occurred in asymptomatic patients during the procedure or in the 6-month follow-up period. At 6 months angiographic follow-up the restenosis rate with a degree of >50% was 3 of 49 (6%) and the rate with a degree of >or=70% was 1 of 49 (2%)., Conclusions: Cerebral embolization during CAS is not the only cause of the stroke and death rate associated with the procedure. The use of cerebral protection devices during the procedure may therefore not prevent all major complications following CAS.

Purpose: To determine the feasibility and safety of angioplasty or angioplasty and stenting of extra- and intracranial vertebral artery (VA) stenosis., Methods: In 16 consecutive patients (9 men, 7 women; mean age 61 years, range 49-74 years) 16 stenotic VAs were treated with angioplasty or angioplasty and stenting. Eleven stenoses were localized in V1 segment, 1 stenosis in V2 segment and 4 stenoses in V4 segment of VA. Fourteen VA stenoses were symptomatic, 2 asymptomatic. The etiology of the stenoses was atherosclerotic in all cases., Results: Angioplasty was performed in 8 of 11 V1 and 2 of 4 V4 segments of the VA. In 3 of 11 V1 segments and 2 of 4 V4 segments of the VA we combined angioplasty with stenting. The procedures were successfully performed in 14 of 16 VAs (87%). Complications were asymptomatic vessel dissection resulting in vessel occlusion in 1 of 11 V1 segments and asymptomatic vessel dissection in 2 of 4 V4 segments of the VA. One patient died in the 24-hr period after the procedure because of subarachnoid hemorrhage as a complication following vessel perforation of the treated V4 segment., Conclusion: Angioplasty or angioplasty and stenting of extracranial VA stenoses can be performed with a high technical success rate and a low complication rate. In intracranial VA stenosis the procedure is technically feasible but complications can be life-threatening. The durability and procedural complication rates of primary stenting without using predilation in extra- and intracranial VA stenosis should be defined in the future.

Our objective was to assess the technical feasibility and the clinical results of internal carotid artery (ICA) stenting using a nitinol self-expanding stent (SMART stent). In 13 patients 13 high-grade stenoses of the internal carotid artery were treated via an implantation of a SMART stent. In all cases a predilation of the stenosis and a postdilation within the stent were performed. Follow-up examinations were carried out in all patients after a period of 6 months. In each case the implantation of the stent was performed without technical complications. In 12 of 13 cases the stent was placed in the patients' internal carotid artery, in 1 case from the internal to the common carotid artery (CCA). The average degree of stenosis of 78% (70-95%) was reduced to an average of 2.8% (0-21%). The 6-month follow-up angiography showed an average degree of restenosis of 11.8% (0-29%) in 8 of 13 patients. Duplex sonography in the remaining 5 patients demonstrated patent stents. One patient showed brief neurological symptoms during the intervention. No further complications occurred during follow-up time. Treatment of internal carotid artery stenosis with the SMART stent seems technically feasible, safe, and promises long-term patency.

Background and Purpose: Concern regarding the safety of stent implantation in the carotid artery exists because of the risk of cerebral embolization during the procedure. The purpose of this prospective study was to determine the incidence of new areas of cerebral ischemia, as detected by using diffusion-weighted MR imaging after stent implantation in the carotid artery., Methods: Diffusion-weighted MR imaging of the brain was performed in 67 patients with 70 high-grade stenoses of the carotid artery before and 24 hours after stent implantation., Results: The neurologic status of the patients was unchanged after 69 of 70 procedures. During one procedure, symptomatic cerebral embolization occurred. Diffusion-weighted MR images showed new ipsilateral lesions after stent implantation in 20 patients (29%), including the symptomatic patient, and new contralateral lesions in six patients (9%). Fifty-two of 59 postprocedural lesions occurred in the vascular territory supplied by the treated vessel. The occurrence of new postprocedural ipsilateral lesions was not significantly correlated with patient demographic data, characteristics of the stenoses, or details of the procedure., Conclusion: In 29% of the procedures, stent implantation in the carotid artery was associated with new areas of cerebral ischemia, as detected by using diffusion-weighted MR images; these findings indicated the occurrence of cerebral microemboli during such procedures. In all patients except one, the new lesions were clinically silent.

Background and Purpose: There has been concern regarding the safety of revascularization procedures of vessels supplying the brain vessels because of the risk of cerebral embolization during the procedure. We have observed a high incidence of hyperintense lesions on diffusion-weighted MR images of the brain after stenting at the carotid bifurcation. The hypothesis of this study is that diffusion-weighted MR imaging of the brain can reveal new diffusion abnormalities after angioplasty or angioplasty plus stenting of arteries supplying the brain, other than at the carotid bifurcation. Therefore, we prospectively obtained diffusion-weighted MR images of the brain before and after such revascularization procedures., Methods: Thirty-seven revascularization procedures were performed in 32 patients. Eleven interventions were performed at the distal internal carotid artery, two at the external carotid artery, two at the common carotid artery, five at the innominate artery, five at the vertebral artery, and 12 at the proximal subclavian artery. Diffusion-weighted MR imaging of the brain was performed before and 24 hours after the procedures., Results: After eight (22%) of 37 procedures, new hyperintensities were visible on the diffusion-weighted MR images. With six of these eight procedures, the hyperintensities occurred in the vascular territory supplied by the treated vessel. In total, 35 new cerebral lesions could be seen, 33 (94%) of which occurred in the vascular territory supplied by the treated vessel. None of the patients in whom new diffusion abnormalities were found had new neurologic symptoms or deficits. No new lesions could be seen after procedures at the subclavian artery., Conclusion: Revascularization procedures of arteries supplying the brain were associated with new lesions on the diffusion-weighted MR images of the brain after 22% of the procedures, provided that MR imaging could be performed, indicating the occurrence of cerebral microemboli during such procedures. Diffusion-weighted MR imaging of the brain can be used as a tool to assess the impact of modifications of procedural technique and/or the use of cerebral protection devices on the occurrence of such lesions.

Purpose: To assess the technical feasibility and the clinical results of cerebral protection with the Angioguard emboli-capture guidewire system during carotid artery stenting (CAS) for high-grade stenoses., Methods: In 20 patients 20 stenoses of the internal carotid artery were treated with stent implantation. In all patients diffusion-weighted (DW) magnetic resonance imaging (MRI) of the brain was performed before and 24 hr after the procedure., Results: The filter device was effectively employed during all steps of the procedure in 16 of 20 patients, in two only postdilation could be protected, and in two no protection was possible. After three of the 20 procedures new ipsilateral cerebral lesions were visualized by DW-MRI. No new permanent neurologic deficits occurred., Conclusion: Cerebral protection with the filter device is technically feasible in most cases. DW-MRI demonstrated new cerebral lesions indicating the occurrence of cerebral microemboli during the protected procedures. Further investigations are necessary to determine whether the use of the cerebral protection device will improve the results of CAS.

Percutaneous transluminal stent-angioplasty of the carotid artery has indications that are similar but not identical to those for carotid surgery. Certain clinical conditions and morphologic findings, such as myocardial infarction, occlusion of the contralateral carotid artery, or tandem stenoses, favor use of the endoluminal technique. On the other hand, large clots at the site of stenosis, heavily calcified plaques, or elongated, kinked carotid arteries are better suited for carotid endarterectomy. Our experiences with angioplasty of more than 800 carotid stenoses and reports of other groups dealing with carotid angioplasty permit a preliminary evaluation of the method. The technical success rates, complication rates, and the few known long-term results are more or less equal to those of vascular surgery. Therefore further prospectively randomized studies are necessary to determine from which procedure the patient with his or her individual condition can gain the highest benefit.

Purpose: To assess the technical feasibility and the results of cerebral protection with the GuardWire Plus Temporary Occlusion & Aspiration System during carotid artery stenting for high-grade stenosis., Patients and Methods: In 20 patients 20 carotid artery stenoses were treated with stent placement under cerebral protection. A contralateral carotid occlusion was an exclusion criteria for the use of the protection device. In all cases only aspiration, but no flushing was used before deflation of the occlusion balloon. In 17 of 20 patients diffusion-weighted (DW-)MRT imaging of the brain was performed before and 24 hours after the procedure., Results: The stent implantation was successfully performed in all patients. In 3 patients neurologic symptoms occurred during the occlusion time. In these 3 patients the symptoms immediately disappeared after deflation of the balloon. In one case there was dilatation of the internal carotid artery at the site of the balloon inflation. In 3 of the 17 DW-MR images new ipsilateral cerebral lesions, in one case a new contralateral lesion occurred after the procedure., Conclusions: The cerebral protection procedure is technically feasible. The occlusion of the internal carotid artery was not tolerated by all patients. The DW-MR imaging demonstrated cerebral lesions indicating the occurrence of cerebral microemboli during the procedure. Further investigations are necessary to determine if the use of the cerebral protection device will improve the results of the carotid artery stenting for high-grade stenoses.

This was a radiologists' preference study to compare a digital chest radiography system that utilizes a large-area silicon flat-panel detector with conventional radiography for visualizing anatomic regions of the chest. Conventional and digital posteroanterior (PA) and lateral chest radiographs were obtained in 115 patients. The PA and lateral image pairs were compared independently by three radiologists rating the overall appearance, 11 anatomic regions in the PA, and 9 in the lateral views. Statistical analysis was performed with the Wilcoxon signed-rank test with Bonferroni-Holm adjustment (p=0.05). For the PA view, the digital system performed significantly better for the overall appearance and for all anatomic regions except for the peripheral pulmonary vasculature and hilum, where no significant difference was found. For the lateral digital images, the regions trachea, costodiaphragmatic recess, and hilum were rated significantly worse. The regions retrosternal and retrocardiac lung were rated significantly better. The other regions and the overall appearance showed no significant differences. The described digital chest radiography system showed statistically superior visualization of anatomic regions for PA and an ambiguous performance for lateral images as compared with conventional radiography. After changing some image processing parameters for the lateral view, this system may be suitable for digitalization of chest radiography.

Purpose: The object of this study was to evaluate the diagnostic accuracy of the stereotactic large core breast biopsy in the histological assessment of mammographically suspicious lesions., Material and Methods: In 106 patients with a mammographically suspicious lesion, 67 with a mass (55 non-palpable, 12 palpable and 39 with microcalcification stereotactic large core biopsies were performed. Samples were obtained in the prone position under local anesthesia with a 14-gauge needle and an automated high-speed gun. An average of 4.3 cores per lesion were acquired. In 68 patients (64%) an additional surgical biopsy was performed, 38 (36%) had clinical and mammographic follow-up., Results: In 4 of the 106 stereotactic biopsies insufficient material for the histological examination was obtained. In the 68 core biopsies with surgical correlation there were no false-positive, but 2 false-negative results with regard to the malignancy of the lesion (sensitivity: 93.8%; specificity: 100%). The 2 false-negative results were obtained in lesions that were mammographically judged as malignant while histology of the stereotactic biopsy showed fibrosis. The stereotactic large core breast biopsy was well tolerated by all patients. No clinically significant complications occurred., Conclusion: The stereotactic large core breast biopsy of a mammographically suspicious lesion can be performed with a high diagnostic accuracy. A correlation of the mammographic and histological findings and a follow-up program are necessary in order to recognize false-negative results early and to avoid a delay in the diagnosis.

Stent angioplasty of atherosclerotic carotid artery stenosis has proven its benefit in 912 treated vessels with a success rate of 99% and a rate of permanent neurological deficit of 2.7%. The procedure is indicated in symptomatic patients with a stenosis of > 70% and in asymptomatic patients > 80%. The early and late results are not significantly different from those of carotid surgery. But the endoluminal treatment is more gentle to the patient, requires a shorter hospital stay and reduces the costs of the treatment. Moreover, patients who are no longer surgical candidates for general medical or local reasons or can only be dealt with surgically with a comparably high risk can be treated.

We report a case of congenital absence of the cervical and petrous part of the left internal carotid artery, the middle and proximal part of the basilar artery, and the V4 segment of the left vertebral artery associated with a left persistent trigeminal artery and a coarctation of the aorta. The left cerebral vessels are supplied via the anterior communicating artery and the left persistent trigeminal artery. The coexisting coarctation of the aorta led to a subclavian steal phenomenon. The alteration of the cerebral hemodynamics has to be taken in consideration when performing cerebral angiography and surgical correction in such a case.

Endovascular treatment of abdominal aortic aneurysms (AAAs) with stent-grafts is increasingly performed. Recent studies have shown that stent-graft placement for AAA is technically feasible and can effectively exclude aneurysms from the circulation. However, complications related to the procedure, such as graft thrombosis, migration of the prosthesis, peripheral embolization, and leaks with incomplete exclusion of the aneurysmal sac, have been reported. We report a case of rectum and sigmoid colon necrosis with fatal outcome due to cholesterol embolization after implantation of a stent-graft for an infrarenal AAA.

Purpose: Angioplasty and stent placement of atherosclerotic internal carotid artery stenosis (ICA) are evaluated based on own experiences with the method and reports of other groups and are compared with vascular surgery., Methods: ICA-stenoses of more than 70% were treated by angioplasty and stent placement mainly using the Wallstent. The patients had follow-up examinations with an angiogram after 6 months and colour-coded duplex ultrasound at regular intervals., Results: In 633 patients 799 ICA stenoses were treated, 70% of them were symptomatic and 30% asymptomatic. In 99% of the patients the stenoses could be removed with a reduction of the degree of stenosis from 82% to 12%. Transient neurological deficits occurred in 5% and permanent deficits in 2.7% of the patients with decreasing incidence over the years. Five-year patency was 91.6%., Conclusion: Endoluminal treatment of atherosclerotic ICA stenosis is an efficient procedure which can be applied in patients, in whom carotid surgery is indicated, but also in cases with an increased operative risk or inoperability from technical or medical reasons.

Bronchiolitis obliterans with organizing pneumonia (BOOP) is a clinicopathological syndrome of unknown etiology. Histopathologically, it is characterized by plugs of fibroplastic connective tissue within respiratory bronchioles, mononuclear cell infiltrates in parenchyma adjacent to the affected bronchioles and foam cells within alveolar air-spaces. The disease usually presents as a subacute illness with complete resolution. A subset of BOOP, however, is associated with a fulminant course and a high lethality due to respiratory failure. Early diagnosis and therapy are mandatory. Chest radiography, computed tomography (CT), bronchoalveolar lavage (BAL) and open lung biopsy are the primary diagnostic techniques. Radiographically, BOOP is characterized by patchy areas of consolidation that are usually bilateral, peripheral and often migratory. In some cases small, round opacities may be observed as the only abnormality. CT can show the pattern of ground glass opacities, areas of airspace consolidation and small, round opacities, while considerable fibrotic change is usually not seen. A reticular roentgenographic pattern, fibrotic changes mainly in subpleural location at CT, lack of lymphocytosis in BAL fluid and histological features of usual interstitial pneumonitis and BOOP in biopsy specimens are all considered risk factors for a fatal outcome.

Mesenteric cysts are considered as a rare cause of abdominal complaints. Histologically, several specific types can be distinguished: lymphangioma, nonpancreatic pseudocyst, enteric duplication cyst, enteric cyst and mesothelial cyst. Histopathological classification and radiological findings in two cases of mesenteric cysts are presented, and, with regard to the literature, radiological appearance and differential diagnoses are discussed.

Sources of the somatosensory evoked fields (SEF) for one subject were estimated using constraints from the magnetic resonance images (MRI) of the same subject. A realistic volume conductor model was shaped corresponding to the inside of the skull. Sources were restricted to a dipole patch riding on the surface of the cortex, reconstructed from the individual MRI. Such a patch can be considered as a uniformly activated cortical area giving rise to distributed currents which flow perpendicular to the cortical surface. Source locations obtained for the SEF in response to separate stimulations of lower lip, first and fifth digit, and collarbone followed the course of the contralateral central sulcus. The order of the estimated source locations was in agreement with the somatosensory homunculus of Penfield and Rasmussen. Similar results were obtained with the simple model of a current dipole in a homogeneous sphere. In contrast, combining a current dipole model with a realistic volume conductor model was rather problematic as it overestimates the radial dipole component by an order of magnitude.

The relative topographical distribution of urokinase-type plasminogen activator (uPA), tissue-type PA (tPA), PA-inhibitor-1 (PAI-1), PA-inhibitor-2 (PAI-2), plasmin(ogen), alpha 2-antiplasmin, and alpha 2-macroglobulin was studied in lesional epidermis of psoriasis vulgaris, and in normal epidermis, by immunohistochemistry. In psoriatic epidermis, tPA predominated, although uPA was found in some biopsies. PAs were not detected in normal epidermis. PAI-1 was not detected in normal epidermis and was only present in a proportion of biopsies of psoriatic lesions. PAI-2 was found in normal and psoriatic epidermis. Plasmin(ogen) was confined to the basal cell layer of normal epidermis, whereas in lesional psoriatic skin it was scattered throughout the epidermis. Alpha 2-antiplasmin and alpha 2-macroglobulin were not found in the epidermis of normal skin. In psoriatic epidermis alpha 2-antiplasmin was confined to the subcorneal layer, whereas staining for alpha 2-macroglobulin was found only in a proportion of biopsies, in the upper epidermis. Our immunohistological findings indicate that colocalization of tPA and its substrate plasminogen may allow efficient generation of plasmin, and that the focal absence of plasmin inhibitors may then favour the persistence of plasmin activity.

The distribution of plasminogen/plasmin, the central proteolytic component of the plasminogen activator/plasmin system was analysed in lesional skin of bullous pemphigoid by using monoclonal antibodies (MAbs) specific for distinct epitopes of the plasminogen/plasmin molecule. Four groups of MAbs were used: (i) MAbs HD-PG 1 and HD-PG 2, specific for epitopes associated with the lysine-binding sites I (kringle domain 1 + 2 + 3) and II (kringle domain 4) of plasminogen/plasmin, (ii) MAbs HD-PG 6 and HD-PG 7, specific for the lysine binding site I only, (iii) MAbs HD-PG 12 (formerly designated P 2) and HD-PG 18, specific for non-kringle domains of glu- and lys-plasminogen, and (iv) MAb HD-PG 13 which recognizes glu-plasminogen, only. The basal cell layers of normal skin consistently reacted with MAb HD-PG 12, whereas only faint staining was seen with the other MAbs in the same biopsies. In contrast, all anti-plasminogen/plasmin MAbs strongly stained lower and intermediate epidermal cell layers of fully developed bullous pemphigoid lesions.