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Biomedical subjects

R J Rizzo

Publications and source records attributed to R J Rizzo.

40 records · Page 3Linked to original sources

Human abdominal aortic aneurysms. Immunophenotypic analysis suggesting an immune-mediated response.

Cellular immunity may play a role in the pathogenesis of atherosclerosis. In this report the potential role of these cells in the formation of abdominal aortic aneurysms by immunohistochemistry was investigated. Aortic tissues from 32 patients were examined: 4 normal aortas, 6 aortas with occlusive atherosclerotic disease, 17 abdominal aortic aneurysms, and 5 inflammatory abdominal aneurysms. Using monoclonal anti-CD3 (T cells), anti-CD19 (B cells), anti-CD11c (macrophages), anti-CD4 (T helper cells), and anti-CD8 (T suppressor cells), several distinctions among these groups were found. The amount of inflammatory cell infiltrate was as follows: inflammatory aneurysms more than abdominal aortic aneurysms more than occlusive aortas more than normal aortas. CD3-positive T lymphocytes rarely were found in the adventitia of normal or occlusive aortas. In contrast, abdominal aortic aneurysms and inflammatory aneurysms exhibited most of the CD3-positive infiltrates in the adventitia. CD19-positive B lymphocytes were present mainly in the adventitia of all pathologic tissues. The CD4-positive:CD8-positive ratio was greater in abdominal aortic aneurysms and inflammatory aneurysms than in the other groups, both in the adventitia and in the media of the aortas. CD11c-positive macrophages were present throughout the diseased tissues, often surrounded by lymphoid aggregates; the greatest numbers of macrophages were found in the inflammatory aneurysm group. Our data suggests that the aneurysmal disease may progress from occlusive disease and is accompanied by an increase in chronic inflammatory cells as well as a redistribution of these cell types. Therefore it is suggested that aneurysmal disease may represent an immune-mediated event.

Antibodies, Monoclonal↗

Collagen types and matrix protein content in human abdominal aortic aneurysms.

Deficiencies of total collagen, type III collagen, and elastin have been proposed to explain aneurysm formation. Infrarenal aortas were collected from 19 patients (age 70 +/- 7 years) undergoing operative repair of abdominal aortic aneurysms (diameter 7 +/- 2 cm) and from 13 autopsies (age 63 +/- 17 years) of patients without aneurysm disease (controls). Wall thickness and collagen and elastin concentration were determined in full-thickness aorta. Collagen types I and III were measured after digestion with cyanogen bromide, which solubilized nearly 90% of total collagen for typing. Cyanogen bromide peptides were separated by sequential carboxymethylcellulose and agarose chromatography and quantified by peak area measurement with computerized image analysis. Histologic examination revealed prominent inflammatory cell infiltration and deficient, fragmented elastin in the aneurysms. Aortic wall thickness was similar in aneurysms and in control specimens. In the aneurysms, collagen was increased (37% +/- 16% vs 24% +/- 5%; p less than 0.05) and elastin was decreased (1% +/- 1% vs 12% +/- 7%; p less than 0.001), expressed as a percentage of delipidized, decalcified dry weight. Collagen type I accounted for 74% +/- 4% of aneurysm and 73% +/- 4% of control collagen solubilized for typing, and collagen type III accounted for 26% +/- 4% of aneurysm and 27% +/- 4% of control collagen solubilized for typing. Neither patients with a family history of aneurysms nor those without a history of aneurysms had collagen type III deficiency. Atherosclerotic abdominal aortic aneurysms are associated with an inflammatory process and may result from elastin degradation and not a deficiency of type III collagen.

Aged↗

Mesenteric venous thrombosis.

Sixteen patients with mesenteric venous thrombosis were reviewed retrospectively during a period from 1983 to 1987. Twelve patients had progressive abdominal pain, three had gastrointestinal bleeding, and one had general malaise. Seven of these 16 patients had previous deep-vein thrombosis. After negative routine gastrointestinal and hepatobiliary evaluation, 11 patients underwent an infusion computerized tomographic scan. Of these, 10 had superior mesenteric vein thrombosis; three of these 10 patients had portal vein thrombosis. Selective arteriography was done in two patients because of gastrointestinal bleeding, and a diagnosis of mesenteric vein thrombosis was made on the venous phase of the examination. The remaining four patients developed acute abdominal symptoms requiring surgical exploration, at which time mesenteric venous thrombosis was discovered. An identifiable coagulopathy was detected in nine patients (protein C deficiency in six, protein S deficiency in two, and factor IX deficiency treated with factor IX concentrate in one). No case of congenital antithrombin-III deficiency was identified. Six of these nine patients had a past history of deep venous thrombosis. Of five patients who underwent surgical exploration, all required bowel resection. In follow-up, two patients died of intestinal necrosis and a third died of associated pancreatic cancer. Thirteen patients were discharged from the hospital. Treatment of coagulopathy was by heparin in three patients and sodium warfarin (Coumadin) in four patients. Long-term anticoagulation was not instituted because of gastrointestinal bleeding in three and cirrhosis in three patients. Mesenteric venous thrombosis can occur without gangrenous bowel. Diagnosis should be suspected when acute abdominal symptoms develop in patients with prior thrombotic episodes and a coagulopathy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Minimally invasive direct access heart valve surgery.

We review our experience with minimally invasive direct access (MIDA) heart valve surgery in 518 patients. Two hundred fifty-two patients underwent MIDA aortic valve replacement (AVR) or repair and 266 underwent MIDA mitral valve repair or replacement. Among the 250 AVRs, 157 (63%) were men, aged 63.2 +/- 14.6 years, NYHA functional Class 2.4 +/- 0.8. The surgical approach was right parasternal in 36 (14%) or upper hemisternotomy in 216 (86%). There were four (2%) operative deaths. Perioperative complications included 14 (5.6%) reexplorations for bleeding, 7 (3%) chest wound infections, 5 (2%) strokes, and 1 (0.4%) external iliac vein injury. Follow-up was complete in 193 (77%) patients, with a mean follow-up of 12 +/- 8 months. Late complications included 2 (0.8%) nonfatal myocardial infarctions, 4 (2%) reoperations for, respectively, 2 pericardial complications, 1 paravalvar leak, and 1 infected valve. There were five (2%) late deaths from congestive heart failure, pneumonia, hemorrhage, aneurysm, and cancer. Mean follow-up NYHA Class was 1.4 +/- 0.6. For the 266 mitral patients, 145 (54.5%) were men, age 58.7 +/- 13.6 years, functional Class 2.3 +/- 0.5. The surgical approach was right parasternal in 195 (73%), lower hemisternotomy in 53 (20%), right submammary thoracotomy in 9 (3.4%), or full sternotomy through a small skin incision in 9 (3.4%). There were 2 (0.8%) operative deaths. Perioperative complications included 4 (1.5%) reoperations for bleeding, 4 (1.5%) strokes, and 5 (2%) wound infections, and 3 (1%) ascending aortic complications. Follow-up was complete in 202 (76%) patients with a mean follow-up of 9.5 +/- 6.4 months. Late complications included one (0.4%) nonfatal myocardial infarction and three (1%) reoperations all converting repairs to replacements. There were three (1%) late deaths from suicide, pneumonia, and sudden death, respectively. Mean follow-up NYHA functional Class was 1.3 +/- 0.5. We conclude that MIDA heart valve surgery is safe and effective for the majority of patients requiring isolated elective aortic or mitral valve surgery.

Adolescent↗