DISCUSSION on the thermodynamics of elasticity in biological tissues.
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Connective Tissue↗
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[Penicillamine-induced elastosis perforans serpiginosa and pulmonary cyst in Wilson's disease (author's transl)].
A large air cyst was removed from the right lung of a 29-year-old female patient with Wilson's disease and penicillamine-induced perforating elastosis, the cyst first appearing after 9 years of treatment with penicillamine. Since, on the one hand, the microscopic and ultrastructural changes in the elastic tissue of the lungs were identical to those observed in the skin, both in areas of clinically-demonstrable elastosis perforans serpiginosa and clinically unaffected skin and, on the other hand, no other pulmonary disease was demonstrable to account for the development of the cystic lesion, it is concluded that penicillamine is the causative factor by means of extensive alteration of the elastic tissue. The morphological changes in the elastic fibres are so characteristic that it is easy to distinguish penicillamine-induced elastosis perforans serpiginosa from the idiopathic variant.
Adult↗
[Changes in the elastic fibers of the skin in rats after long-term motor loading and immobilization].
The histologic changes were followed up that took place in the elastic fibers of the skin of a total of 30 female rats of the Wistar line at the initial age of 45 days. The animals were kept under the conditions of enhanced or lowered locomotor activity. It was found that as functional elements in the particular layers of the skin the elastic fibers altered considerably their specific morphologic characteristic under the effect of a varying loading the body with muscular activity. The skin of those of the animals that were loaded with enhanced locomotion presented a strongly developed hyperplastic net of elastic fibers of considerable thickness and density. On the other hand, the skin of the animals that were immobilized showed atrophic and reduction processes involving the elastic tissue; in such case the characteristic structure and network arrangement were only presented by sporadic fibres and bundles. The changes seen in the structure and organization of the elastic tissue once again demonstrated the importance of the higher or lower functional loading of the body with physical work for the development of hyper- or hypotrophic processes in the various tissues and organs.
Animals↗
A histomorphological study in age related changes in the elastic fiber system of the basilar artery.
The aim of the study was to quantify the distribution of elastic fibers within the wall of the basilar artery. Three age groups were studied: 1) 0-1 yr.; 2) 20-50 yr. 3) > 50 yr. A histomorphometrical study was undertaken using an estimation of the linear density of the components of the fibrous elastic tissue system: the full length in the proximal and distal segments of the basilar artery was evaluated. Our results showed that: The elastic tissue of the basilar artery is not evenly distributed throughout the tunica media. Compared to the 0 to 1-year age group, mature elastic, elauninic and oxytalan fibers decreased with age. In all age groups the linear density of the mature elastic fibers was more evident in the proximal than in the distal segment of the artery.
Adult↗
Familial cutaneous collagenoma: a clinicopathologic study of two new cases.
Two siblings with familial cutaneous collagenoma syndrome had the essential clinical features of multiple skin-colored nodules on the trunk and upper arms. On light microscopy, histopathologic findings included excessive accumulation of dense, coarse collagen in the dermis. Elastic tissue stains demonstrated a proportionately diminished number of abnormal elastic fibers intermingled with the collagen bundles. A predominance of densely packed collagen bundles of normal morphology with a marked decrease in abnormal elastic tissue were the major ultrastructural features. The diagnosis was therefore confirmed to be connective tissue nevi of the collagen type. The differential diagnosis of connective tissue nevi disorders is delineated.
Child↗
Generalized elastosis perforans serpiginosa in Down's syndrome.
Elastosis perforans serpiginosa is a rare disorder of epidermal perforation characterized by the extrusion of dermal elastic tissue through the epidermis. Its aetiology is unknown, but there is histological and biochemical evidence of an abnormality of elastic tissue. Three forms of elastosis perforans serpiginosa exist. It may be either idiopathic, iatrogenic, or, in approximately one quarter of cases, associated with certain genetically determined disorders of connective tissue. Cutaneous lesions appear between the ages of 6 and 20 years, and persist for 6 months to 5 years. They may be confined to one anatomic area, or less frequently are disseminated. We review the case of a 28-year-old woman with recent onset of unusually extensive elastosis perforans serpiginosa with co-existing Down's syndrome and (secondary) sclerosing cholangitis.
Adult↗
Proposal: trauma as the cause of the Peyronie's lesion.
PURPOSE: We define the cause of the occurrence of Peyronie's disease. MATERIALS AND METHODS: Clinical evaluation of a large number of patients with Peyronie's disease, while taking into account the pathological and biochemical findings of the penis in patients who have been treated by surgery, has led to an understanding of the relationship of the anatomical structure of the penis to its rigidity during erection, and how the effect of the stress imposed upon those structures during intercourse is modified by the loss of compliance resulting from aging of the collagen composing those structures. Peyronie's disease occurs most frequently in middle-aged men, less frequently in older men and infrequently in younger men who have more elastic tissues. During erection, when full tumescence has occurred and the elastic tissues of the penis have reached the limit of their compliance, the strands of the septum give vertical rigidity to the penis. Bending the erect penis out of column stresses the attachment of the septal strands to the tunica albuginea. RESULTS: Plaques of Peyronie's disease are found where the strands of the septum are attached in the dorsal or ventral aspect of the penis. The pathological scar in the tunica albuginea of the corpora cavernosa in Peyronie's disease is characterized by excessive collagen accumulation, fibrin deposition and disordered elastic fibers in the plaque. CONCLUSIONS: We suggest that Peyronie's disease results from repetitive microvascular injury, with fibrin deposition and trapping in the tissue space that is not adequately cleared during the normal remodeling and repair of the tear in the tunica. Fibroblast activation and proliferation, enhanced vessel permeability and generation of chemotactic factors for leukocytes are stimulated by fibrin deposited in the normal process of wound healing. However, in Peyronie's disease the lesion fails to resolve either due to an inability to clear the original stimulus or due to further deposition of fibrin subsequent to repeated trauma. Collagen is also trapped and pathological fibrosis ensues.
Cumulative Trauma Disorders↗
Elastosis in neoplastic and non-neoplastic tissues from patients with mammary carcinoma.
We studied a series of 585 patients with non-invasive or invasive ductal carcinoma in an attempt to assess the significance of elastosis. Elastosis in the neoplasm was recognized in 60% of the 549 patients with invasive ductal carcinoma. The grade of elastosis was correlated with both the histologic grade of differentiation and the 5-year survival rate. The incidence of elastosis, however, was 17% in the 36 patients with non-invasive ductal carcinoma and 38% in the 21 with invasive ductal carcinoma with a predominant intraductal component. The increased elastic tissue may therefore be influenced by the stromal infiltration of cancer cells. Mastectomy specimens from another series of 100 patients with mammary carcinoma were examined with regard to the volume of elastic tissue. Increased periductal elastic fibers were also identified in the non-neoplastic tissue, but the volume density was far less than in the neoplasm. A significant correlation was found between the increased amount of periductal elastic fibers in the non-neoplastic tissue, periductal elastosis of the neoplasm and an increase in parity. We propose that cancer cells in mammary carcinoma exert an inductive effect on mesenchymal cells for the synthesis of elastic material, under the basic condition of an increased amount of elastic fibers with an increase in parity.
Breast Neoplasms↗
Abnormalities of fibrillin in acquired cutis laxa.
BACKGROUND: Degeneration of elastic tissue in acquired cutis laxa has been previously described, but microfibrils have not been adequately studied. OBJECTIVE: We determined whether the microfibrillar component of elastic tissue is affected in skin of a patient with acquired cutis laxa. METHODS: Lesional skin was examined with indirect immunofluorescence and immunoelectron microscopy with antibodies to fibrillin. RESULTS: Indirect immunofluorescence showed a reduction in the distribution of fibrillin in the papillary dermis, where there was loss of the usual pattern of microfibrils perpendicular to the epidermis. Immunoelectron microscopy showed a typical distribution of elastic microfibrils around elastin of normal skin. In skin affected by cutis laxa microfibrils appeared morphologically normal but appeared less frequently in selected sites. CONCLUSION: The microfibrillar component of elastic fibers was reduced in the papillary dermis of this patient with acquired cutis laxa.
Actin Cytoskeleton↗
Transluminal laser catheter angioplasty.
The first transluminal laser angioplasty in animals is reported herein. An Argon laser and a specialized coronary arterial catheter with a fiberoptic wave guide were used. Immediate histologic changes consisted of a moderate degree of intimal necrosis and some loss of elastic tissue. At 5 days the intima was repaired, but focal elastic tissue loss persisted.
Angioplasty, Balloon↗
Abnormal accumulation of elastin-associated microfibrils during elastolysis in the arterial wall.
We examined the correlation between elastolysis and abnormal accumulation of microfibrils in the arteries of rabbits using light and electron microscopic and tissue culture techniques. Partial constriction of the common carotid arteries of rabbits gave rise to gradual atrophy of the media with elastolysis and an unusual accumulation of microfibrils. With advancing experimental atherosclerosis in cholesterol-fed rabbits, the elastofibrotic intima generally became thick and hyalinized and was replaced by bundles of microfibrils lacking elastin or associated with only tiny elastin aggregates and disrupted elastic fibers. Organ cultures of aortic explants from rabbits with or without pancreatic elastase supplementation for 5 days disclosed that there was complete loss of medial elastic fibers and increasing deposition of microfibrils, morphologically identical to elastin-associated microfibrils, around viable smooth muscle cells only in the elastase supplemented group. These observations suggest that abnormal accumulation of microfibrils in the elastic tissue is closely associated with excessive elastolysis of preformed or newly formed elastic fibers during elastic tissue remodeling. Enhanced synthesis of microfibrils may occur in response to elastolysis as a reparative phenomenon.
Actin Cytoskeleton↗
Elastic fibers in fetal dermis.
Dermal elastic tissue in fetal skin was evaluated by light microscopy using three different staining techniques. Postmortem skin was obtained from the abdominal wall of 45 fetuses ranging in age from 8 to 42 weeks. Elastic fibers were first detected in skin from fetuses of 22 weeks and, with increasing gestational age, appeared to increase in quantity and complexity. Skin from fetuses older than 32 weeks had a well-developed network of elastic fibers throughout the dermis. There was no diminution of dermal elastic tissue during the latter part of the sixth lunar month as had been reported in a previous study.
Body Weight↗
Some histological aspects of the hip joint capsule in the vervet monkey.
Microscopic studies show that the capsule of the hip joint in the vervet monkey (Cercopithecus aethiops pygerythrus) is preponderantly collagenous. Among the collagen fiber bundles are varying quantities of elastic fibers that demonstrate a definite, differential regional distribution. The highest concentration of elastic tissue is found in the posterior, postero-inferior, and inferior aspects of the hip joint capsule, whereas the anterior and superior aspects of the capsule are preponderantly collagenous. It is postulated that this regional distribution of elastic tissue is related to the differential functional requirements of the posterior, postero-inferior, and inferior aspects of the capsule for flexibility and stretchability. These requirements appear to be a consequence of the habitual postures and locomotory positions assumed at the hip joint by these primarily quadrupedal primates. Collagen, on the other hand, being much more resistant to deformation and relatively noncompliant, is the predominant tissue in the anterior and superior aspects of the joint.
Animals↗
Ultrastructural changes in scleromyxedema.
Skin biopsy specimens from a 60-year-old patient with paraproteinemia and generalized changes of the skin typical of scleromyxedema were studied with the electron microscope. The dermis was dominated by collagen fibrils and accumulations of peculiar connective tissue cells, while elastic tissue was sparse and in some areas completely absent. Large, sharply demarcated areas of a filamentous material were occasionally observed. The collagen fibrils were often surrounded by thin filaments with a periodic segmentation and by many glycosaminoglycan (mucopolysaccharide) filaments. The elastic fibres contained large amounts of elastic fibrils and small amounts of a homogenous matrix. The cytoplasm of the above-mentioned cells was dominated by lysosomes in different stages of development, often occupying almost all the cytoplasmic area. The collagen fibrils were found in close relation to these cells, frequently inside invaginations of the cells. Furthermore, collagen fibrils were observed free in the cytoplasmic area and inside the lysosomes, indicating lysosomal degradation of collagen.
Cell Membrane↗
Myogenic foam cells in explants of fatty dots and streaks from rabbit aorta. Morphological studies.
Present studies indicate that in explants of early atherosclerotic lesions removed from aortae of young rabbits on a 1% hypercholesterolemic diet for four and seven weeks respectively, myogenic foam cells (MCF's) were capable of emigrating into the culture medium and maintained their ability to produce microfibrils, elastic tissue elements, and collagen fibrils. In explants of the smallest lesions (fatty dots and small streaks) the MFC's divided prior to, or while emigrating. At the interphase between the primary tissue and the culture medium they contained in intracytoplasmic vacuoles fragments of elastic tissue and extraneous substances which were reminiscent of cellular debris. It is possible that this phenomenon represents a true phagocytic property of the MFC's. All formed extracellular connective tissue components were also produced by the emigrated MFC's in the tissue surrounding the cellular outgrowth. In the large fatty streaks cell division was observed at the interphase between the tissue and culture medium, but not within the substance of the explant; here cellular necrosis was prominent. The fat inclusions in the MFC's of explants and the outgrowth had the appearance of conglomerateds of unorganized, and only at times concentric, membranous profiles rather than that of homogeneous droplets observed by electron microscopy in these cells in tissue sections. In the outgrowth from explants of normal aortic areas adjacent to the lesions a moderate number of smoot muscle cells contained fat inclusions; these were almost totally absent in cells of the primary aortic cultures from normal aortae. It is conceivable that the migratory and phagocytic properties of the MFC's observed in the present study relate to some aspects of regression of atherosclerotic lesions; this, however, remains highly speculative at present.
Animals↗
Degradation of porcine dermal connective tissue by collagenase and hyaluronidase.
Selective destruction of connective tissue may be a useful therapeutic tool in conditions associated with abnormal deposition of scar tissue. We have investigated intradermal injections of clostridial collagenase and bovine testicular hyaluronidase alone and in combination in Yucatan miniature hairless pigs. Collagenase in combination with hyaluronidase was quite efficient at destroying the connective tissue matrix, although elastic tissue appeared to be completely spared. Collagenase alone at higher doses degraded collagen, but hyaluronidase had little effect on connective tissue architecture.
Animals↗
Dynamic response of the intracranial system in the conscious dog to papaverine hydrochloride.
The influence of papaverine on the intracranial system of the dog was studied by measuring the pressure-depth-time response for the intact intracranial system, i.e., for the subarachnoid and subpial compartments. This was accomplished by a measurement system which provided an accurate pressure-depth determination and a uniform rate of transducer insertion. Distinct regions of the intracranial system (subarachnoid, transitional, and subpial) were identified from inflections in the pressure response curve. The test parameter, brain relative stiffness (BRS), was obtained by determining the slope of the pressure response values within the subpial region. This parameter is a measure of the "stiffness" or elasticity of bring tissue within the test configuration. A bolus injection of papaverine (1 mg per kilogram, i.v.) caused an increase in the transitional region, a compensatory reduction in the subarachnoid space, and an increase in BRS. It is postulated that at normotensive arterial blood pressure, cerebrovascular expansion caused by papaverine resulted in increased brain tissue elasticity, i.e., an increase in the pressure-depth response for the subpial region. Possible implications for this increase are discussed. Experiments should be conducted in which local blood flow studies are coupled with measurements of brain elastic response.
Animals↗
The conduction system of the swine heart.
Although the pig has been used as an experimental model for ischemic heart disease and sudden death, relatively little is known about the anatomy of the conduction system (CS) of this animal. We attempted to correlate electrophysiologic and anatomic differences between the pig and human CS. Invasive electrophysiologic studies were performed in five healthy anesthetized pigs. In contrast to the adult human, the pig has sinus tachycardia, shortened PR and H-V intervals, and a relatively short sinoatrial conduction time. Compared with the human CS, serial sections of the CS of pig hearts showed the following differences: (1) the atrioventricular node is located more to the right of the summit of the ventricular septum; (2) the penetrating bundle is very short, and the bifurcation of the bundle into bundle branches occurs more proximally; (3) there is more connective tissue and less elastic tissue; and (4) there is a copious amount of nerve fibers (about 50 percent throughout the CS). The presence of the abundant neural tissue implies that there is an important neurogenic component to conduction in the pig. Because of the above differences from the human, the pig should be used with caution as an experimental model in ischemic heart disease and sudden death where arrhythmias are studied.
Animals↗