Maxillary ameloblastic fibroma in a dog.

A 4-year-old spayed female Golden Retriever was presented for evaluation of a rostral maxillary gingival mass. An en bloc resection was performed after histologic diagnosis of ameloblastic fibroma from an incisional biopsy specimen. Histologically, the tumor was composed of (1) poorly differentiated vimentin-positive mesenchymal cells that surrounded islands and (2) thin anastomosing trabeculae of odontogenic epithelium that variably coexpressed pancytokeratin and vimentin. To the authors' knowledge, this is the first report of ameloblastic fibroma in a dog. The clinical, radiographic, and histologic findings in this case are compared to those in other domestic animals and humans.

Biochemical characterization of proteins that co-purify with class II antigens of the murine MHC.

Careful analysis of affinity-purified class II molecules (Ia Ag) from the murine MHC revealed the existence of a set of associated molecules that consistently co-purified with the Ia Ag. SDS-PAGE revealed that molecules of Mr of 41 to 43 kDa and 56 to 58 kDa were associated with the affinity-purified I-Ak Ag from the AKR B cell lymphoma AKTB-1b. Two-dimensional electrophoresis (IEF vs SDS-PAGE) allowed further characterization of four molecules in the 41- to 43-kDa range and two in the 56- to 58-kDa range. All co-purifying proteins had isoelectric points between 5.2 and 6.2. The specificity of the association of the co-purifying molecules with the I-Ak Ag was established by using two criteria. First, with the exception of actin, proteins co-purifying with the I-Ak molecule were not found in samples of affinity-purified class I (H-2Kk) Ag or membrane Ig from the AKTB-1b lymphoma. Second, the use of the amino group-reactive homobifunctional cross-linker 3,3'-dithiobisproprionimidate with crude membranes from AKTB-1b increased the relative amount of materials co-purifying with I-Ak. The use of the membrane-impermeant cross-linker 3,3'-dithiobis(sulfosuccinimidyl) proprionate provided evidence that the interaction between I-Ak and one or more of the co-purifying components occurs on the cytoplasmic face of the membrane. Two of the co-purifying molecules have been identified. The major material in the 41- to 43-kDa range was partially sequenced, leading to its identification as cytoplasmic actin. One of the components in the 56- to 58-kDa range was tentatively identified as one of the isozymes (RII) of the regulatory subunit of the cAMP-dependent protein kinase, based on the use of the photoaffinity label 8-azido-cAMP.

The role of coronary artery disease in complications of abdominal aortic aneurysm surgery.

Coronary artery disease (CAD) is a major cause of morbidity and mortality after elective surgical repair of abdominal aortic aneurysm (AAA). The aim of this study was to determine the relationship between the extent of CAD observed in coronary angiograms (more than 50% stenosis) and the frequency of postoperative myocardial ischemic complications in a consecutive series of 84 patients who underwent elective AAA repair. Ninety-four percent of the patients with clinical evidence of CAD had significant disease as observed in coronary angiograms and eight patients had left main CAD. Seventy-two patients underwent AAA repair with a mortality rate of 1.4%; five patients had preliminary myocardial revascularization, and AAA surgery was not recommended for four patients because of severe cardiac disease. Postoperative myocardial ischemic complications occurred in 13.4% of the patients who had undergone surgery--almost exclusively in patients with clinical evidence of CAD. Both myocardial ischemia and preoperative intervention were more frequent in patients with double- or triple-vessel disease than in patients with less extensive disease. Patients with symptoms and with double- or triple-vessel CAD have a high risk of developing myocardial ischemia after AAA surgery. Preliminary myocardial revascularization may be beneficial in this group of patients.

The use of regional, low dose streptokinase in recently thrombosed arterial grafts.

Between August 1983 and January 1985, 20 patients aged 33-77 years, with occluded lower limb bypass grafts, were on 23 occasions treated with streptokinase via intra-arterial infusion. Streptokinase (5000 units/h) was effective in clearing occluded grafts in 15 patients on 16 occasions. The median duration of occlusion in these patients was 5 days and the median duration of streptokinase infusions was 24 h. Completion angiography following streptokinase thrombolysis revealed five graft stenoses and 12 outflow stenoses or occlusions. In two grafts no cause for graft failure could be identified. These results permitted the surgeon to make an accurate pre-operative assessment of the definitive therapy required to ensure graft patency.

The role of primary varicose veins in venous ulceration.

"Venous" ulceration is usually ascribed to deep venous insufficiency. We record the cases of 20 patients with 23 ulcers without a history suggestive of deep vein disease who were found to have a normal deep venous system when evaluated by Doppler ultrasound, ambulatory venous pressures, and photoplethysmography. All had gross varicose veins present for many years (mean 24 years; range 10 to 35 years), and only 14 limbs had incompetent calf perforating veins. Effective treatment is facilitated by recognition of the relationship of varicose ulcer to superficial venous disease, usually incompetence of the saphenofemoral junction, with or without the presence of incompetent calf perforating veins.