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Tissue vitronectin in normal adult human dermis is non-covalently bound to elastic tissue.

Vitronectin is a multifunctional human plasma glycoprotein that is also found in constant association with elastic tissue fibers in normal adults. We have investigated the nature of the association of vitronectin with elastic tissue, and compared it to that of other elastic fiber-associated proteins, namely fibrillin and amyloid P component. Samples of normal human dermis were incubated with a variety of extraction agents, including high molar salt solution, non-ionic detergent (Nonidet P-40), the reducing agents dithiothreitol or 2-mercaptoethanol, and the chaotropic agents sodium dodecyl sulfate or guanidine hydrochloride. Vitronectin purified from serum typically migrates as two bands of 75 and 65 kD. By contrast, immunoblotting studies of residual dermal material after extraction with the various agents revealed only lower molecular weight (58, 50, 42, 35, and 27 kD) anti-vitronectin reactive bands. Although these bands may represent degradation products of vitronectin generated as a result of the extraction procedure, we cannot exclude the possibility that tissue vitronectin is distinct from plasma vitronectin. Anti-vitronectin reactive polypeptides co-migrating with the 58-, 50-, and 42-kD bands were solubilized following extraction with sodium dodecyl sulfate or guanidine hydrochloride, but not with the other extraction agents. Immunofluorescence studies using residual dermal material after extraction with guanidine hydrochloride demonstrated a marked reduction in elastic fiber staining intensity with anti-vitronectin and anti-amyloid P component, but not with anti-fibrillin. Thus the majority, if not all of dermal vitronectin, is, like amyloid P component, non-covalently associated with, and not an integral constituent of, elastic fibers.

Blood Proteins↗

Elastic tissue in early intraoral wounds.

Histochemical analysis of elastic tissue in early intraoral healing of wounds demonstrated that these fibers were concentrated in the perivascular areas of granulation tissue and within newly formed connective tissues at the base of the wound. These results were consistent with previous reports indicating that the cellular origin of this tissue is smooth muscle cells or fibroblasts.

Animals↗

Elastic tissue in scars and alopecia.

A recent report suggests that elastic fibers appear in scars in a time-dependent fashion. This observation prompted our investigation, because we have found elastic tissue stains helpful in determining the pattern of scarring in cases of permanent alopecia. We carried out this investigation to determine if the Verhoeff-Van Gieson (VVG) elastic stain can reliably differentiate scarred from non-scarred dermis and to test our hypothesis that elastic stained sections are helpful in distinguishing lichen planopilaris (LPP) from lupus erythematosus (LE), central progressive alopecia in black females ("follicular degeneration syndrome" and "hot comb alopecia" are other terms used to describe this condition) and classic ivory white idiopathic pseudopelade. We studied histological sections from surgical scars of known duration, stained with the VVG elastic stain and VVG-stained sections of scalp biopsies from patients with established lesions of permanent alopecia. In most cases, both vertical and transverse sections were examined. In every case, the VVG stain clearly differentiated scar from the normal surrounding dermis. Distinct patterns of elastic tissue allowed for correct classification in most of the well-established cases of permanent alopecia studied. We determined that the Verhoeff-Van Gieson stain is an excellent stain to evaluate the pattern of scarring in cases of permanent alopecia and elastic tissue stains may be helpful in the histological evaluation of alopecia.

Alopecia↗

[Elastography: Quantitative imaging modality of the elastic tissue properties].

The wide range of elastic tissue properties and the difference in elasticity of tumors and the adjacent tissues have provided motivation for developing elasticity imaging techniques. These research efforts have converged with the development of a new imaging modality, the so-called elastography, with the acquired and processed images referred to as elastograms. This modality was pioneered for ultrasonic imaging, which provides the majority of experience on this topic. MR-elastography has been developed in recent years. The published clinical data range from the characterization of prostate and breast cancer in oncology and dynamic examinations of skeletal muscle to intravascular elastic differentiation of vessel plaques. Advantages of the ultrasonic elastography are ubiquitous applicability and cost-effectiveness. MR elastography offers improved reconstruction and the possibility to assess potential anisotropic properties. The different approaches of elastography, their technical and clinical application and the limitations known so far are reviewed in this paper.

Anisotropy↗

A computerized image analysis method for measuring elastic tissue.

A computerized image analysis technique for quantifying area fractions of elastic tissue in light microscopic sections is presented that considers the nonuniform distribution of the elastic tissue. The method uses Verhoeff-van Gieson stained sections. The analysis is stratified vertically in three uniform layers starting at the dermo-epidermal junction and horizontally by two schemes. A standard method consists of five equally spaced measurements. The densest method uses the three areas that contain the most elastic tissue. The area fractions are determined by counting the positive and total pixels (thresholding). A validity test utilizing independent physical measurements demonstrated differences of no more than 1.7%. Reliability tests for reading the same section on different days and adjacent sections showed no significant differences (p less than 0.05) between the readings. Reliability tests of sections using different stain lots and adjacent biopsy sites also did not have significant differences. This method may be particularly useful for studies in which the distribution of the material to be measured may be very uneven, such as in solar elastosis.

Biopsy↗

Decrease of elastic tissue fibres in stem villus blood vessels of the human placenta during IUGR and IUGR with concomitant pre-eclampsia.

In a recent study we described an increase of elastic tissue fibres in blood vessel walls of placental stem villi during pre-eclampsia when compared to uncomplicated pregnancies. Furthermore, the thickness of these blood vessel walls was enhanced in pre-eclampsia. Since it is known that elastic tissue fibres increase in systemic hypertension, it may be assumed that the enhancement of elastic tissue fibres in placental stem villi during pre-eclampsia may be induced by the hypertension. To get further insight into this assumption, we examined the amount of elastic tissue fibres in stem villus blood vessels of placentae of pregnancies complicated by intrauterine growth retardation (isolated IUGR, fourteen cases), a disease without hypertension of the mother and such with pre-eclampsia and concomitant IUGR (IUGR+PE, nine cases). Each study group was compared with uncomplicated pregnancies (twenty-six cases). Unfixed cryostat serial sections were processed for conventional orcein staining and for the demonstration of alpha-actin-immunoreactivity. The intensity of orcein staining of stem villus blood vessel walls was evaluated by a semiquantitative score method. Significant lower intensities of orcein staining were calculated for blood vessel walls of placentae of isolated IUGR (P=0.0007) and IUGR+PE (P=0.0039) when compared to uncomplicated pregnancies each. Additionally, the blood vessel wall thickness of stem villi of isolated IUGR (P=0.0081) and IUGR+PE (P=0.0007) was significantly reduced. In comparison to the above mentioned investigation, our results show that, in contrast to isolated pre-eclampsia, elastic tissue fibres are decreased during pregnancies complicated by IUGR, independently of the occurrence of concomitant pre-eclampsia when compared to uncomplicated pregnancies. From our studies it may be considered that the increase of elastic tissue fibres in placentae of patients with isolated pre-eclampsia may be induced by systemic hypertension. Furthermore, our study underline arguments that IUGR may be an independent disease of the fetus.

Adult↗

Actinically degenerate elastic tissue is the likely antigenic basis of actinic granuloma of the skin and of temporal arteritis.

Staining technique is paramount for detecting and assessing the severe degeneration that occurs in the elastic tissues of the skin and its arteries in response to prolonged exposure to actinic radiation. With a selective "controlled" hematoxylin-and-eosin stain, actinically damaged ("elastotic") elastic tissue stains blue, as Unna described, and contrasts with normal and simply hyperplastic elastic tissue, which stains red. "Special" elastic stains such as Orcein and Verhoeff do not demonstrate this difference. When resorptive (elastolytic) giant cell reactions develop in relation to actinically degenerate elastic tissue of the skin, the papules that arise tend to form expanding, annular rings. A previously used and appropriate name for these autoimmune lesions in the skin is actinic granuloma because this name highlights the likely actinic origin and pathogenesis of many such lesions. Granulomatous inflammation in connection with actinically degenerate internal elastic lamina appears to be the basis of temporal arteritis. Actinic granulomas may occur in the skin concurrently with temporal arteritis. A recent study of temporal arteritis strongly relates its elastic tissue changes to those of "accelerated" atherosclerosis.

Adolescent↗

[Diffuse disease of elastic tissue and hyperphosphoremia].

Pseudoxanthoma elasticum (PXE) is exceptionally associated with abnormal phosphate-calcium metabolism. On the other hand, significant hyperphosphataemia is present in tumoral calcinosis, with an occasional elastopathy resembling that of PXE. We report here the first case of diffuse elastic tissue disease associated with hyperphosphataemia in the absence of tumoral calcinosis. The patient, a 29-year old Gabonese, had severe arteritis of the lower limbs with linear calcifications of the aorta and major arteries of the limbs. Angioid streaks and calcifications were present in the retinas. The skin appeared to be normal, but histological examination of specimens from flexures showed abnormalities of the elastic tissue with many fibres being broken into small pieces and curled up. In a morphometric study of cutaneous elastic tissue these abnormalities were compared with those observed in a PXE patient and with normal elastic tissue. The abnormalities in our patient and in the PXE patient were similar. Compared to normal elastic tissue, there was a slight decrease in the total number of oxytalan and elaunin fibres. The elastic fibres were distinctly wider, longer and separated from each other by smaller spaces, but not more numerous than normally. The histopathological appearance of an artery removed during bypass surgery was similar to that of a PXE artery. The hyperphosphataemia was due to an increase in tubular absorption of phosphates without abnormalities of parathyroid hormone, or resistance to its phosphaturic effect or any other tubular disorder. It was little altered by aluminium carbonate, and it partially decreased after addition of calcitonin.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Spontaneous elastic tissue lesions in the rat abdominal aorta, a genetically determined phenotype.

In this study, phenotypic expression of spontaneous elastic laminae defects within the rat abdominal aorta was examined. Lesions in Brown Norway (BN) rats were compared with those of New Zealand genetically hypertensive (GH) rats. BN and GH rats were cross-bred to determine the phenotypic expression of these lesions in successive F(1) and F(2) generations. Lesions were assessed by distribution, number and a semiquantitative index of severity. All BN aortae contained numerous elastic tissue defects. In comparison, GH aortae contained only occasional elastic tissue lesions. F(1) aortae contained lesions in numbers similar to those of the parental BN strain; however, F(1) lesions were of significantly greater severity. Within the F(2) generation, a wide range in both lesion numbers and severity indices was observed, with approximately a quarter of animals having lesion numbers analogous to the GH parental strain. In conclusion, this study indicates that the spontaneous elastic tissue lesions observed within BN rats are consistent with an autosomal dominant, possibly single gene, effect. Moreover, epistatic effects, derived from the GH strain, may influence the severity of these lesions. The gene(s) responsible may be important in the development of conditions such as arteriosclerosis and aneurysms in humans.

Animals↗

Effect of maternal nicotine exposure on neonatal lung elastic tissue and possible consequences.

The effect of maternal nicotine exposure (1 mg/kg body mass/d) on the lung elastic tissue of 1-day-old rat pups was investigated. The results show that maternal nicotine exposure resulted in a very low elastic tissue content in the lungs of these rat pups compared with those of the controls. This may interfere with normal lung development since elastic tissue is part of the lung connective tissue structure and is involved in the formation of alveoli. Impaired elastic synthesis may thus make the rat pups more susceptible to lung diseases such as emphysema.

Animals↗

Effect of thiouracil upon canine arterial elastic tissue.

Unlike some other mammalian species, the dog is relatively resistant to the development of elevated levels of serum cholesterol after prolonged cholesterol feeding. This may be overcome by suppressing thyroid activity with thiouracil. Information regarding possible activity of thiouracil itself upon the arterial tissues is almost nonexistent. The present investigation was undertaken to test whether this drug has any such action, especially upon the arterial elastic tissues. Destructive changes were observed in arterial elastic tissues in dogs given thiouracil for three and six months. The changes consisted of accentuation of the elastic fibrillar components, formation and subsequent coalescence of clefts, and fragmentation and ultimate "dissolution" of the elastic elements. The results suggest that thiouracil may exert a damaging effect upon the arterial elastic fibers; thus, it is possible that one of the mechanisms by which thiouracil and cholesterol administration induces experimental atherosclerosis in the dog is by elastic tissue destruction, possibly promoting the subsequent lipid accumulation in the arterial wall.

Animals↗

Elastic tissue dysplasia of the internal carotid artery.

Elongation with kinking of the internal carotid artery is not an uncommon finding. Cerebral vascular insufficiency has been reported secondary to this abnormality. Although arteriosclerosis is a frequent cause in adults, the etiology in children has never been explained. Three children with significant kinking of the internal carotid artery are reported here. Each underwent surgical correction by excision and reconstruction. Histological review showed the elastic tissue to be disrupted, diminished in amount, and unevenly distributed. Retrospective examination of this elastic tissue dysplasia showed it to be localized, there being normal morphology both proximally and distal to the involved area. There was recurrence of elongation and kinking in one patient due to incomplete excision. Correction was accomplished after re-excision of the involved tissue with a vein graft interposition. From this study, it can be concluded that elongation and kinking of the internal carotid artery in children is secondary to elastic tissue dysplasia. It is imperative that the entire involved area be removed in order to prevent recurrence. The excised specimen should be studied histologically with elastic tissue stains. Such stains cannot be performed as frozen section. Should permanent studies show the margins of resection not to be beyond the dysplastic tissue, careful followup of these children is essential to recognize recurrence.

Carotid Artery Diseases↗

Elastic tissue injury in human acute pancreatitis.

Pancreatic vessel wall alterations were studied in tissue material obtained from six patients subjected to resection of the gland for acute necrotizing pancreatitis. Special attention was paid to elastic tissue damage, which was studied using special stains in light and electron microscopy. Vascular wall elastic laminae showed changes varying from fragmentation to complete dissolution. The outer elastic lamina was more consistently affected. Elastic tissue damage was observed in pancreatic areas with minor acinar alterations and in vessels with otherwise relatively well-preserved walls. These observations suggest 1/ an early participation of elastase in the production of tissue damage in human acute pancreatitis and 2/ a primary role for elastic tissue injury in the vascular alterations leading to haemorrhage and tissue necrosis through ischaemia.

Acute Disease↗

Elastic tissue in fibroepithelial polyps.

Fibroepithelial polyps are common cutaneous lesions with an unknown etiology. We attempted to demonstrate that fibroepithelial polyps develop secondary to a focal loss of elastic tissue. Forty-five fibroepithelial polyps were examined. All were stained with Verhoeff-van Gieson stain for elastic tissue and examined. All but one specimen had a normal amount of elastin and none revealed abnormally shaped elastic fibers. Abnormal or decreased elastic tissue is not the cause of fibroepithelial polyps.

Elastic Tissue↗

Elastic tissue abnormalities resembling pseudoxanthoma elasticum in beta thalassemia and the sickling syndromes.

The development of clinical and histopathologic manifestations of a diffuse elastic tissue defect, resembling inherited pseudoxanthoma elasticum (PXE), has been encountered with a notable frequency in patients with beta thalassemia, sickle cell disease, and sickle thalassemia. The PXE-like clinical syndrome, consisting of skin, ocular, and vascular manifestations, has a variable severity in these hemoglobinopathies and it is age-dependent, with a generally late onset, after the second decade of life. The defect is believed to be acquired rather than inherited and related to the consequences of the primary disease. The high prevalence of the findings implicates the elastic tissue injury as one of the main comorbid abnormalities encountered in beta thalassemia and the sickling syndromes. In these patients a number of complications, sometimes serious, has been recognized to be related to ocular and vascular elastic tissue defects. Because several organ systems are involved, each medical specialty should be aware of the phenomenon. This coexistence, on the other hand, introduces a novel pathogenetic aspect of PXE and an important research challenge.

Adult↗