Multifocal epithelioid angiosarcoma of bone: a potential pitfall in the differential diagnosis with metastatic carcinoma.

A case of multifocal epithelioid angiosarcoma of the femur, tibia, fibula, and astragalus in a 54-year-old man is reported. The tumor was composed of nests and cords of malignant cells with epithelioid morphology, with foci of vascular differentiation, necrosis, and hemorrhage. By immunohistochemistry, the neoplastic cells showed positivity for endothelial cell markers (CD31, CD34, factor VIII-related antigen, and Ulex europaeus agglutinin I), epithelial markers (cytokeratins and epithelial membrane antigen), and vimentin.

Regulation of vascular growth and regression by matrix metalloproteinases in the rat aorta model of angiogenesis.

Matrix metalloproteinases (MMPs) have been implicated in the formation of microvessels during angiogenesis, but their role in vascular regression is poorly understood. The rat aorta model of angiogenesis was used to study the function of MMPs at different stages of the angiogenic process. Gelatin zymography and Western analysis demonstrated production of MMP-2 and MMP-9 by aortic outgrowths in serum-free collagen gel culture.

Thoracoscopic reduction pneumoplasty for severe emphysema: do pleural adhesions affect outcome?

Background: Pleural adhesions are frequently encountered in patients undergoing reduction pneumoplasty. We evaluated the impact that pleural adhesions had on the surgical technique and outcome of thoracoscopic reduction pneumoplasty.

Methods: 59 operated patients were divided into 2 groups depending on the presence (group A) or absence (group B) of pleural adhesions.

Autoregulation of angiogenesis by cells of the vessel wall.

The cells of the vessel wall can regulate angiogenesis by producing growth factors, proteolytic enzymes, extracellular matrix components, cell adhesion molecules, and vasoactive factors. This property enables preexisting blood vessels to generate new vessels in the absence of exogenous angiogenic stimuli. Vascular autoregulation of angiogenesis can be studied by culturing rat aortic or venous explants in collagen gels under serum-free conditions.

Solitary fibrous tumor of the perithyroid soft tissue. Report of a case simulating a thyroid nodule.

A case of solitary fibrous tumor (SFT) of the perithyroidal soft tissue is reported. Due to its proximity to the upper aspect of the right thyroid lobe, its slow growth and its ultrasound features, the tumor was confused with a thyroid nodule. Two fine needle aspirations (FNA) gave only scant non diagnostic material.

Rat aortic smooth muscle cells become pericytes during angiogenesis in vitro.

Background: We previously reported that the intimal endothelium of the rat aorta switches to a microvascular phenotype during angiogenesis in vitro. The microvessels formed by the rat aortic endothelium are coated with pericytes. The purpose of this study was to evaluate the relation of the pericytes to the angiogenic process and to identify the site of origin of these cells in the aortic wall.

Isolation of a morphologically and functionally distinct smooth muscle cell type from the intimal aspect of the normal rat aorta. Evidence for smooth muscle cell heterogeneity.

Recent studies indicate that the neointima of injured rat arteries is composed of a subpopulation of smooth muscle cells (SMCs) distinct from medial smooth muscle cells. However, SMC diversity in normal adult aorta has remained elusive. This study characterizes two morphologically and functionally distinct SMC types isolated from different anatomic regions of the normal rat aorta.

Paracrine interactions between fibroblasts and endothelial cells in a serum-free coculture model. Modulation of angiogenesis and collagen gel contraction.

Background: Previous data suggest that paracrine interactions between fibroblasts and endothelial cells modulate the formation of granulation tissue during wound healing. The study of these interactions in vivo is hindered by the interference of serum and other cell types. To overcome this limitation, we developed a serum-free in vitro model in which microvessels were cocultured with fibroblasts in a 3-dimensional collagen gel.

Isolation and characterization of vasoformative endothelial cells from the rat aorta.

We describe here a modified nonenzymatic method for the isolation of rat aortic endothelial cells with vasoformative properties. Aortic rings placed on plastic or gelatin-coated surfaces generated outgrowths primarily composed of endothelial cells. Prompt removal of aortic explants after endothelial migration minimized fibroblast contamination.

Angiogenic role of endogenous basic fibroblast growth factor released by rat aorta after injury.

The autocrine role of basic fibroblast growth factor (bFGF) in angiogenesis was studied in the rat aortic ring-collagen gel model using serum-free culture conditions. Immunohistochemical staining of the rat aorta showed bFGF in the cytoplasm of endothelial and smooth muscle cells. Aortic rings mechanically injured during the dissection procedure released bFGF, which was demonstrated in the conditioned medium by slot and Western blot analysis.

Large-vessel endothelium switches to a microvascular phenotype during angiogenesis in collagen gel culture of rat aorta.

The purpose of this study was to investigate the vasoformative behavior in vitro of the native intimal endothelium of the rat aorta. To visualize the intimal surface directly, thoracic aortas were everted using a procedure that sequestered adventitial cells and possible remnant microvessels of periaortic soft tissues inside the aortic tube. Everted aortas embedded in collagen gel and cultured under serum-free conditions generated branching microvessels by a process of sprouting from the aortic intima.

Damage and repair of mouse bronchial epithelium following acute inhalation of trichloroethylene.

The time-course of damage and repair in the bronchial epithelium of the mouse was studied morphometrically after a single inhalation of trichloroethylene (TCE). Mice were exposed for 30 min to 500, 1000, 2000, 3500, or 7000 ppm of TCE under controlled conditions and sacrificed after 2 and 24 h, and 2, 5, and 7 days. At all TCE concentrations, the damage consisted of dilation of endoplasmic reticulum and was selective for nonciliated cells throughout the bronchial tree.

Cystic mesothelioma of the peritoneum. A report of three cases.

Three cases of peritoneal cystic mesothelioma are reported. All patients were women who had undergone previous abdominal surgery for unrelated conditions. Tumors consisted of solitary and multiple cystic masses involving the abdominal and pelvic peritoneum.

[Occult carcinoma of the thyroid gland: an epidemiological study of autopsy material].

The occurrence of occult thyroid carcinoma at autopsy was examined in 507 consecutive autopsies performed over one-year in subjects without clinical evidence of thyroid cancer, from different regions of Italy, including areas of endemic goiter. We found 54 (10.65%) occult thyroid carcinomas.

[Critical reflections on differentiated carcinoma of the thyroid: difficulties, doubts and differential-diagnosis problems].

This work reviews the problems associated with the diagnosis of well differentiated carcinomas of the thyroid (follicular and papillary), which anatomically and clinically can show characteristics not readily distinguishable from those found in thyroid hyperplasia and adenomas. Some features of atypical adenomas and Hurthle cell tumors are detailed, in particular the borderline malignancy of the latter. We have examined the histological parameters useful in diagnosis of follicular carcinoma (cellular polymorphism and size variability with increased and atypical mitoses, invasion of the capsule and vessels, metastasis to lymph nodes and distant organs) and of papillary carcinoma (true papillae, large and crowded nuclei displaying a "ground glass" appearance with grooves and cytoplasmic inclusions and psammoma bodies).

Reconstitution of cytochrome c oxidase in phospholipid vesicles containing polyvinylic polymers.

Cytochrome c oxidase was reconstituted in phospholipid vesicles in the presence of highly hydrophobic poly(vinyl alkanoate) polymers. Electron-microscopy observations demonstrated that polymer interaction with the lipid phase induces vesicles to adopt smaller diameters than those typical of standard proteoliposomes. Functional characterization of these polymer-proteoliposome structures indicates that the reconstitution of the enzyme proceeds efficiently without causing either scrambling of the protein orientation in the membrane or loss of respiratory control.

Inhibition of adsorptive endocytosis and transcytosis in pulmonary microvessels.

In isolated perfused rat lungs we have examined the effect of inhibition of receptor-mediated endocytosis and of intracellular acidic compartments activity on adsorptive and fluid-phase uptake and transport of macromolecules by capillary endothelium. Cationized and native ferritin were used as electron-dense tracers of adsorptive and fluid-phase transport, respectively. Luminal endothelial vesicles were labeled with tracers at 4 degrees C for 2 minutes and the density of ferritin particles in endothelial multivesicular bodies and in the capillary basement membrane, after a 60-minute chase with tracer-free perfusate at 37 degrees C, was determined by electron microscopic morphometry.

Binding and uptake of native and glycosylated albumin-gold complexes in perfused rat lungs.

We have examined, by electron microscopy, the effect of glycosylation on binding, uptake, and transport of albumin-gold complexes in capillaries of isolated perfused rat lungs. Lungs were perfused for 2 min at 4 degrees with native and glycosylated albumin-coated gold particles. After the excess probe was washed out for 5 min the lungs were fixed immediately or perfused for 30 and 60 min at 37 degrees with a isoosmotic buffer before fixation.

Alveolo-capillary membrane in primary pulmonary hypertension.

This study was undertaken to detect diagnostic ultrastructural changes in the alveolar walls in biopsies of patients with primary pulmonary hypertension (PPH). Open lung biopsies from 8 patients referred to the Hospital of the University of Pennsylvania were available for study. By light microscopy 4 patients were diagnosed as having plexogenic pulmonary arteriopathy, 2 thromboembolic arteriopathy and 2 veno-occlusive (PVOD) disease.

Foam cells in the development of human atheroma: a morphological and autoradiographic approach.

Human arterial biopsies were studied by morphometrical, cytochemical, autoradiographic and ultrastructural methods with the aim of determining whether intimal lesions in atherosclerosis are characterized by definite cytological patterns. The results have shown: 1. a strong association between fibro-atheromatous plaques and foam and monocyte-like cells; 2.

Correlation between increased serum and tissue L-carnitine levels and improved muscle symptoms in hemodialyzed patients.

A group of 14 uremic patients on intermittent hemodialysis was admitted to a cross-over double-blind trial in order to evaluate serum and muscle carnitine levels before and after 60 days of L-carnitine oral (2 g/day) treatment. The morphology of muscle fragments was studied by light and electron microscopy. Symptoms (asthenia, cramps) occurring during hemodialysis were also recorded.

Autoradiographic and ultrastructural studies on the human fibro-atheromatous plaque.

Foam cells, either myogenic or macrophagic, are commonly detected in experimental and human fibro-atheromatous plaques. Their role in human atherosclerosis is not yet understood. This paper reports on a preliminary autoradiographic study combined with ultrastructural observations in the human fibro-atheromatous plaque.

Plasma and muscle carnitine levels in haemodialysis patients with morphological-ultrastructural examination of muscle samples.

The present study investigates 14 patients on intermittent haemodialysis. Pre-dialysis blood and muscle samples taken for determining plasma free- and acetylcarnitine levels. The tissue fragments were used for light and electron microscopy studies.