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Biomedical subjects

C Haudenschild

Publications and source records attributed to C Haudenschild.

At least 37 records · Page 2Linked to original sources
PubMed1983

Angiogenesis inhibition and tumor regression caused by heparin or a heparin fragment in the presence of cortisone.

Heparin or a heparin fragment administered with cortisone inhibited angiogenesis, caused regression of large tumor masses, and prevented metastases. Oral administration of heparin resulted in the release of non-anticoagulant heparin fragments in the serum which, in the presence of cortisone, had similar anti-angiogenic and antitumor effects. Of all the heparin fragments tested, the most potent inhibition of angiogenesis in the presence of cortisone was provided by a hexasaccharide with a molecular weight of about 1600.

Animals↗
PubMed1983

The mechanism of transluminal angioplasty: evidence for formation of aneurysms in experimental atherosclerosis.

Quantitative histologic examination (morphometric analysis) of pressure-perfused rabbit atherosclerotic arteries was used to determine whether compression of atheromatous material occurs with transluminal angioplasty. Experimental atherosclerosis was developed in both iliac arteries, with transluminal angioplasty performed on the left iliac while the right iliac served as a nondilated control. Angiography showed equal degrees of luminal narrowing before angioplasty (p = NS). Angioplasty reduced the left iliac narrowing in all animals studied. Morphometric analysis of histologic sections of the left and right iliac arteries disclosed significant differences in luminal and total vessel areas (p less than .05), whereas arterial wall (intima and media) areas were similar (p = NS). Dilated areas often demonstrated marked intimal splitting with dissection into the media. At higher magnification, loss of nuclear staining and dense layers of extracellular matrix consistent with stretching were frequently seen. It is concluded that the major mechanism of successful transluminal angioplasty is stretching of the vessel, resulting in localized aneurysm formation. Intimal splitting implies inelasticity of the neointima. No evidence of compression and remodeling of atheromatous material was disclosed in this study.

Aneurysm↗
PubMed1982

Transluminal angioplasty in experimental atherosclerosis. Analysis for embolization using an in vivo perfusion system.

We used polarized light microscopy and thin-layer chromatography to determine whether embolization of atherosclerotic material occurs after transluminal angioplasty. The experimental model consisted of an in vivo perfusion system of the atherosclerotic rabbit left iliac artery. Of eight rabbits that underwent successful angioplasty, four had angiographic evidence of dissection and three showed aneurysm formation. Histologic studies demonstrated fracture of the intimal plaque, dissection, and stretching of the noninvolved portion of the vessel. Perfusate analysis revealed no detectable cholesterol by thin-layer chromatography in six of eight rabbits. In two rabbits, a very small amount of cholesterol was measured, which was totally accounted for by hemorrhage into the perfusate rather than from cholesterol in the plaque. No evidence of arterial wall embolic debris could be detected by polarized light microscopy in seven rabbits, but lipid debris from the plaque was found in the perfusate of one rabbit that had excessive arterial trauma. We conclude that the major mechanism of successful transluminal angioplasty in this experimental model is intimal fracture combined with stretching of a noninvolved portion of the vessel. Furthermore, embolization of atheromatous lipid debris was an uncommon event related to arterial trauma during catheter placement rather than transluminal angioplasty itself.

Angioplasty, Balloon↗
PubMed1981

Protection of endothelium in vessel segments excised for grafting.

Contracture and collapse often complicate dissection and excision of blood vessels for grafting. Subsequent forceful redilatation and leak checking with cold saline almost always lead to partial or total denudation of endothelium, which increases the risk of early occlusion by thrombi or late occlusion by fibrocellular initimal thickening. To prevent endothelial damage, we used three major modifications of the excision and extracorporeal maintenance procedures: (1) adventitial application of the smooth-muscle relaxant papaverine in situ to avoid contracture and to allow subsequent gentle, gradual redilatation at low pressure; (2) balanced perfusion and maintenance fluid containing 10% protein (serum of albumin); and (3) extracorporeal maintenance of the vessel at body temperature. In an experimental extracorporeal vascular perfusion system, we could preserve morphologically intact endothelium of rabbit carotid arteries for over 3 hours, as evaluated by scanning electron microscopy. Applying the same principles to canine cephalic and saphenous veins, we gradually dilated the vessels at pressures as low as 100 mm Hg and obtained a morphologically intact endothelium after 1 hour of extracorporeal maintenance.

Animals↗
PubMed1981

An improved technique for preservation of endothelial morphology in vein grafts.

Scanning electron microscopy was performed on 29 canine and two human veins prepared for vein grafting by means of various techniques. Endothelial morphology was best preserved when veins were pretreated with papaverine before excision, when a warm solution was used for dilatation, when the grafts were stored up to 1 hour either in a warm, nutritive medium (Dulbecco's modified eagles) or a cold, nonnutritive solution (saline), and when the grafts were maintained in the distended state. Distending pressure up to 500 mm Hg did not cause injury to veins prepared by these techniques. The use of cold solutions to distend veins was especially harmful.

Animals↗
PubMed1980

Angiogenesis in vitro.

Cloned capillary endothelial cells, cultured in tumour-conditioned medium, form capillary tubes. By light and electron microscopy these tubes resemble capillaries in vivo. This first demonstration of angiogenesis in vitro: (1) shows that all the information necessary to develop an entire capillary network in vitro is expressed by one cell type; (2) suggests a mechanism for lumen formation; and (3) offers a possibility of distinguishing between direct and indirect angiogenesis factors.

Angiogenesis Inducing Agents↗
PubMed1980

Control of tumor growth in animals by infusion of an angiogenesis inhibitor.

Angiogenesis and tumor growth were inhibited in two different animal models by regional infusion of a partially purified cartilage extract. In rabbits bearing corneal implants of V2 carcinoma and receiving the inhibitor, vascular growth rates were < 3% of those in control animals receiving either Ringer's solution or bovine trypsin inhibitor (Trasylol). Subconjunctival B16 melanoma implants in mice receiving the inhibitor weight < 2.5% of implants in mice receiving Ringer's solution, Trasylol, or albumin. Histologic study of major organs and standard blood tests revealed no toxic effects in any of the animals. The inhibitor did not retard the growth of either tumor cell type in tissue culture at concentrations as high as 1 mg/ml. These results suggest that the cartilage factor does not interfere with the growth of the tumor cell population directly but that it prevents tumor growth by inhibiting angiogenesis.

Animals↗
PubMed1980

Angiogenic activity as a marker of neoplastic and preneoplastic lesions of the human bladder.

Angiogenic activity has been assessed in biopsy specimens from 49 patients with transitional cell carcinoma, benign prostatic hypertrophy and vesicoureteral reflux. Over 95% of the specimens containing malignant and premalignant transitional epithelium stimulated capillary proliferation on rabbit iris. In contrast, less than 10% of normal tissues had this effect. Sixty-one per cent of specimens with inflammatory round cells were angiogenic but this was reduced to 10% by preincubation with rabbit antihuman lymphocyte serum. Cystitis cystica also induced capillary proliferation even if incubated with the antilymphocyte serum. Angiogenic capacity may be an early marker of preneoplastic and neoplastic lesions of the human bladder.

Angiogenesis Inducing Agents↗
PubMed1980

Angiogenesis by capillary endothelial cells in culture.

Capillary endothelial cells cloned from bovine and human tissues were grown in long-term culture. In the presence of tumor-conditioned medium, capillary tubes formed when the cells became confluent. Each tube began as a longitudinal vacuole in one cell and then appeared to be extruded and connected from one cell to the next. Branches appeared, and a capillary network developed over a period of 2 to 3 weeks. By light and electron microscopy, the tubes were nearly identical to capillaries in vivo. These experiments: (1) Demonstrate angiogenesis in vitro; (2) Show that all the information necessary to develop an entire capillary in vitro can be expressed by one cell type; (3) Suggest a mechanism for lumen formation by capillaries in vivo; (4) Offer a possibility of distinguishing between direct and indirect angiogenesis factors.

Animals↗
PubMed1978

Angioimmunoblastic lymphadenopathy: an ultrastructural and immunologic study with review of the literature.

Six cases of angioimmunoblastic lymphadenopathy (AIBL) are presented, detailed ultrastructural and immunohistologic studies of several involved organs are described, and the literature is reviewed. The features of the lesion are of normal immune reactive cells containing polyclonal cytoplasmic immunoglobulin. Large numbers of dying and degenerating cells result in accumulations of cell debris, corresponding to the characteristic interstitial material seen by light microscopy. Our studies confirm that the vascular changes are unique to lymph nodes, appear confined to postcapillary venules, and consist of endothelial cell hypertrophy and expansion of the vessel wall by basement membrane-like material, cellular debris and collagen fibers. No deposits of amyloid or antigen-antibody complexes were noted by ultrastructural or immunologic techniques. Our data reveal morphologic and laboratory features of a hyperimmune state but with paradoxical cutaneous anergy and decrease in blood (T) lymphocytes. We postulate that AIBL is an abnormal, but non-neoplastic immune reaction related to the autoimmune disorders, resulting from a loss of suppressor T cells with hyperfunction of the B lymphocyte system.

Adult↗
PubMed1976

The chick chorioallantoic membrane as a model system for the study of tissue invasion by viral transformed cells.

The chick chorioallantoic membrane (CAM) was used as an assay system to investigate the the invasive properties of viral transformed NIH/3Y3 cells. Scanning electron microscopy demonstrated that single Kirsten sarcoma virus (KiSV)-transformed cells passed between the epithelial cells of the CAM ectoderm within 6 hr of application, while viable NIH/3T3 cells did not penetrate the ectoderm within 24 hr. The transformed cells entered the mesoderm of the CAM and formed tumors of proliferating cells. The application of 5 X 10(5) KiSV-transformed cells resulted in the formation of donor cells resulted in the formation of the donor cell tumors within 5 days in 43% of the membranes. No tumors were formed when as many as 5 X 10(6) NIH/3T3 cells were applied to the membrane. NIH/3T3 cells transformed by the Abelson leukemia virus or the Moloney sarcoma virus also ivaded the CAM and formed tumors of proliferating cells within the mesoderm, while cells infected with the Moloney leukemia virus did not. NIH/3T3 cells inoculated onto the CAM 8 days after infection and transformation with KiSV formed tumors with a frequency similar to that of KiSV transformed cells that have been passaged in culture for many generations. Cells that formed invasive tumors within the mesoderm also attracted loops of host blood vessels.

Animals↗