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PubMed1998

Immunoreactivity of adventitial matrix fibrils of normal and aneurysmal abdominal aorta with antibodies against vitronectin and fibrinogen.

PURPOSE: We have reported that immunoglobulin G (IgG) harvested from specimens of aneurysmal abdominal aorta (AAA) is immunoreactive with a fibrillar component of the matrix of the aortic adventitia. In further studies we have reported the partial amino acid sequence of a 40-kDa protein, purified from the adventitia of the human aorta, which we have called aortic aneurysm antigenic protein-40 kDa (AAAP-40). AAAP-40 has homologies with bovine microfibril-associated glycoprotein-36 kDa (MAGP-36). Both AAAP-40 and MAGP-36 have homologies to fibrinogen beta (FB-b) and vitronectin (VN). The purposes of the present experiments were (1) to determine whether antibodies against VN and fibrinogen are immunoreactive with elements of the normal and/or aneurysmal aortic wall, and (2) to determine whether these antibodies are immunoreactive with soluble extracts of aortic proteins. METHODS: Paraffin-embedded tissue sections of normal and aneurysmal aorta were probed with polyclonal rabbit antihuman VN and antihuman FB-b antibodies. Immunoblots of soluble aortic proteins were evaluated with the same antibodies. Histochemical preparations with Gomori's aldehyde fuchsin and elastin-von-Gieson solutions were also performed. RESULTS: Anti-VN and FB-b antibodies reacted with matrix fibrils in the aortic adventitia in both normal and aneurysmal specimens, with a distribution that resembles the appearance of fibrils that are stained by Gomori's reaction. By comparison to normal adventitial fibrils, fibrils in the specimens from AAA appeared fragmented, coiled, and frayed. Antibodies against VN and FB-b were immunoreactive in immunoblots with a soluble aortic protein of molecular weight approximately 40 kDa, consistent with the migration of AAAP-40. CONCLUSIONS: There appear to be immunodeterminants in AAAP-40 that are recognized by polyclonal antibodies against VN and FB-b.

Aortic Aneurysm, Abdominal↗
PubMed2000

Costello syndrome with decreased gene expression of elastin in cultured dermal fibroblasts.

We report a case of Costello syndrome. A 2-year-old Japanese boy presented with a 'coarse' face, curly hair and loose skin of the dorsal aspect of the hands and feet with dark pigmentation. A skin biopsy of the dorsal aspect of the left hand revealed hyperkeratosis and papillomatosis of the epidermis, hyperpigmentation of the basal layer, and shortening and rupture of elastic fibers of the dermis. Electron microscopy of dermal elastic fibers showed a decreased amount of elastin with an exposed appearance of microfibrils. In Northern blot analysis of cultured dermal fibroblasts, elastin mRNA levels were reduced, suggesting a decrease in elastin production at the lesions of loose skin.

Abnormalities, Multiple↗
PubMed1975

Central neuroblastic tumour associated with smooth muscle fibers. A study in the optic and electron microscopes.

The present paper is a study of a microcystic intraspinal tumour that developed in a 4-year-old child. The histologic examination showed the presence of neuroblastic elements developing next to smooth muscle fibers. The tumour had diffusely invaded the meninges, presenting a marked collagen reaction. Ultrastructurally, the neuroblastic elements exhibited an arrangement proper to the neural tube and the presence of a series of osmiophil neurosecretory dense-core vesicles. The fine structural morphology of the smooth muscle fibers was clearly revealed, the cells containing microfibrils and being delimited by a basement membrane. The muscular fibers were visibly in contact with the blood vessels. These aspects demonstrate that the medullomyoblastoma is a malignant bidermal teratoid tumour of the central nervous system. Dysgenesis of the ectomesenchyma may be considered to stand at the basis of the development of this type of tumour.

Child, Preschool↗
PubMed1991

Subepithelial elastic system fibers of oblique mucosal folds in the rat proximal colon.

The proximal colon of the rat is characterized by a 'herring bone' pattern of oblique mucosal folds (OMF) which are arranged in a parallel array. By light and electron microscopy the OMF exhibited rich subepithelial elastic system fibers which bound the epithelial basement membrane and the smooth muscle cells of the lamina propria together. The elastic system fibers usually consist of elastic, elaunin and oxytalan fibers. However, the subepithelial elastic system fibers of the OMF were composed of relatively thin elastic fibers with a few microfibrils, and elaunin and oxytalan fibers which were almost indiscernible. Areas other than the OMF were quite poor in subepithelial elastic system fibers. The interpositions between each of the OMF were composed of typical components: elastic, elaunin and oxytalan fibers. The composition of the subepithelial elastic system fibers of the OMF does not correspond to that of any other organs previously reported. The present study suggests that the OMF of the rat proximal colon might be equipped in such a way to resist to distension or compression.

Animals↗
PubMed1994

Invasiveness of mouse trophoblastic cells in connective tissue.

Ectoplacental cones from 8-day-old mouse embryos were grafted into the dorsal subcutaneous tissue of host mice. The grafts were collected between the 3rd and 8th days after transfer and processed for morphological analysis by light and electron microscopy. Approximately 60% of the grafts formed hemorrhagic nodules in which only invasive, giant trophoblastic cells developed. These cells shared many morphological features with the trophoblastic cells involved in normal implantation. At the periphery of the nodules, trophoblastic giant cells were frequently seen growing toward the host connective tissue. The association between the trophoblast and fibrilar components of the extracellular matrix was examined. No direct association with collagen fibrils was noted; however, many areas of the surface of invasive cells were in close proximity with microfibrils of the extracellular matrix. Since only the invasive trophoblast cells exhibited such an association, a direct comparison was made with the process of trophoblast migration within the connective tissue.

Animals↗
PubMed1975

Effect of sex hormones on rabbit arterial subendothelial connective tissue.

The effect of sex hormones on subendothelial connective tissue in rabbit arteries was sought, and striking morphological alterations were noted after prolonged treatment. Depot preparations of testosterone cypionate, 100 mg/week, or estradiol cypionate, 200 mug/week, were injected intramuscularly into intact adult New Zealand male rabbits for 8-16 weeks. The iliac arteries were prepared for electron-microscopic examination from five rabbits in each treatment group and in four normal male rabbits. Thin sections were prepared from three randomly selected cross-sectional tissue blocks for each animal. A minimum of 7 mum of vessel circumference was studied in each block. Selection of an area for electron-microscopic examination was random, except that those sites in which the internal elastic lamina showed fragmentation were discarded. Electron micrographs at a single final magnification were evaluated 'blind' by several observers for qualitative difference in subendothelial constituents. In the control group, the subendothelium contained moderate numbers of elastin-associated microfibrils (MF); all the rabbits given testosterone consistently showed significantly fewer MF than the control. In contrast, rabbits given estradiol all had significantly greater numbers of MF. Statistical analysis of variance showed these difference to be significant at p less than 0.001.

Animals↗
PubMed1990

Glomerulonephritis with organized deposits: a new clinicopathological entity? Light-, electron-microscopic and immunofluorescence study of 12 cases.

Twelve cases of glomerulonephritis in patients without systemic diseases, displaying organized glomerular deposits, were reported. Microfibrils (11-30 nm diameter) were found in 9 patients and microtubules (20-35 nm diameter) in the other 3. Histochemical stainings for amyloid were always negative. By light microscopy, mesangial proliferative, membranous and membranoproliferative patterns were seen in 5, 3 and 4 patients, respectively. By immunofluorescence, granular deposits, mainly of IgG and C3, were found in all cases, either in the mesangium or in the mesangium and in the capillary walls. A second biopsy was performed in 2 patients. The number of hyaline glomeruli was increased, but the general pattern of glomerular changes remained unchanged. The commonest clinical findings were hypertension, microhematuria and proteinuria, often of nephrotic range. At variance to what is reported in the literature, 2 pediatric cases were found as well, and the overall prognosis (mean follow-up 54.3 months) was mostly favorable. The diagnostic relevance of these findings is pointed out, but further investigations are needed, before suggesting a new clinicopathological entity.

Actin Cytoskeleton↗
PubMed1991

Immunotactoid glomerulopathy and cutaneous vasculitis.

A 22-year-old woman presented glomerulonephritis with Schönlein-Henoch-like syndrome and monoclonal abnormality. One month later, she developed a rapidly progressive glomerulonephritis with hypertension and persistent purpura. In the two renal biopsies performed during the first and the second attack, mesangial expansion and thickening of the glomerular capillary walls (associated with 50% of crescents in the second biopsy) were observed on light microscopy. By immunofluorescence faint deposits of immunoglobulins (light and heavy chains) and complement components were found present in the mesangium. Electron microscopy showed tubular microfibrils measuring 19-24 nm in the mesangium, subendothelial and subepithelial areas. A skin biopsy performed during the first attack demonstrated leukocytoclastic skin vasculitis. By immunofluorescence, no deposits were observed. Congo red staining for amyloid and cryoglobulinemia were negative. This case is similar to an entity recently described and named immunotactoid glomerulopathy.

Adult↗
PubMed1996

Renal disease in Marfan syndrome.

We encountered 4 individuals with Marfan syndrome who presented with microhematuria and proteinuria. In 2 of them, a renal biopsy was performed. The predominant glomerular change by light microscopy was a focal segmental increase in mesangial matrix with early sclerotic lesions. Ultrastructurally, there was variable subendothelial widening containing haphazardly arranged microfibrils, 10-13 nm in diameter. Changes in small arteries present in the biopsies were mild in case 1 and more striking in case 2 which consisted of elastolysis and fragmentation and focal disruption of internal elastic lamina, and focal degenerative changes in the media. In light of observations on the abnormalities of microfibrillar protein (fibrillin) in the microfibrillar-fiber system and the presence of abnormal type IV collagen in the connective tissues in Marfan syndrome, the glomerular basement membrane alterations may be related to these defects and lead to microhematuria and proteinuria.

Arteries↗
PubMed1988

Glomerulonephropathy with amyloid-stain-negative microfibrillar glomerular deposits.

A 44-year-old man demonstrated proteinuria, microhematuria and renal dysfunction during the course of hyperthyroidism. Neither cryoglobulinemia nor paraproteinemia including light chains was found. No systemic signs suggestive of amyloidosis appeared. Histological findings showed a diffuse mesangial matrix increase with slight mesangial proliferation and diffuse granular depositions of IgG, IgA, C3, C4, Clq, kappa and lambda light chains. Ultrastructurally, microfibrils of about 20 nm in width were seen to be deposited diffusely in mesangial areas and in glomerular basement membranes. Congo red and thioflavin T staining were negative. These findings support the possible existence of a specific glomerular disease different from amyloidosis.

Adult↗
PubMed1994

Trichothiodystrophic hair reveals an abnormal pattern of viscoelastic parameters.

Separate analysis and quantitative determination of the viscous and elastic parameters of hair performed in 5 patients with trichothiodystrophy and in 20 sex- and age-matched control subjects revealed an abnormal pattern of the mechanical behavior of trichothiodystrophic hair. The change of the viscous parameter is probably associated with the profound alterations in the high-sulfur proteins of the interfilamentary matrix; the changes in the elastic parameters may be related to the reduced stability of the irregularly arranged microfibrils of trichothiodystrophic hair caused by the marked reduction of the disulfide cross-links.

Adolescent↗
PubMed1997

Mechanical behaviour of scalp hair in premature and full-term neonates.

Using a new computerized methodological procedure a separate analysis and a quantitative determination of the viscous and elastic parameters of the scalp hair shaft were performed in 37 neonates of both sexes with a gestational age of 28-29 weeks (n = 16) and 39-40 weeks (n = 21), respectively. A statistically significant (p < 0.001) decrease in the values of modulus of elasticity (E alpha) was found in the hair shaft of premature neonates, as compared to the full-term ones, whereas the values of post yield slope (E beta) and of SDIS/SSTOR (viscous parameter) did not significantly differ in the two groups. The decrease in modulus of elasticity in the hair shaft of premature neonates may be interpreted in terms of an insufficient number of disulphide bonds between the alpha-helical keratin units of the hair cortex or of a disordered arrangement of microfibrils within the matrix. Further studies are now warranted to determine the pattern of mechanical parameters of the scalp hair shaft in large numbers of newborn infants of different gestational ages and to answer the question as to whether this pattern might be useful in the accurate postnatal assessment of fetal maturation.

Biomechanical Phenomena↗
PubMed1987

Different effects of elastase on dermal elastic fibers with age. Ultrastructural studies with the conventional and tannic acid stain.

The effect of elastase on dermal elastic fibers from three age groups (children, young and old adults) has been investigated using ultrathin sections embedded in Epon. There were significant differences in the effect of elastase among the age groups; younger elastin was more rapidly digested by elastase than older elastin. In children and young adults, digested areas by elastase were first recognized as tiny round holes scattered in the amorphous material of the elastic fiber, extending to the large part of the fiber except for microfibrils. In old adults, digested areas were limited to the only small part of the elastic fiber.

Actin Cytoskeleton↗
PubMed1988

Ageing of the skin: study of elastic fiber network modifications by computerized image analysis.

We quantitated the skin elastic fibers of the papillary and reticular dermis using specific staining procedure followed by automated computerized image analysis. Fifty skin biopsies of patients consulting for cardiovascular risk factors were studied. The following parameters were estimated: surface area (% of total surface), length, and number of fibers as a function of age. The evaluation of the skin elastic fiber system showed no significant trend with age in the number of elastic fibers per unit area in the superficial or deep dermis. We found, however, a continuous increase with age in the relative surface area, and the length of the elastic fiber system. These results can best be interpreted as a continuous apposition of elastic-type material to the preexisting fibers by skin fibroblasts. This material may well be of a different composition than young elastin, for instance enriched in structural glycoproteins (microfibrils), lipids and calcium as found in the elastic fibers of aorta and lung. Such quantitative modifications may explain the decrease in skin elasticity, and the continuous increase in stained fibers.

Adult↗
PubMed1995

The collagen superfamily.

The collagens represent a large family of molecular proteins which are located in the extracellular matrix. They all share a triple-helical segment of variable length (100-450 nm) but differ considerably in the size and nature of their globular domains. The various collagen types I-XIX known so far in vertebrates are adjusted to different functions including the formation of fibrils, microfibrils and networks. Their biological role is now increasingly studied by genetic approaches.

Animals↗
PubMed1997

Scarring folliculitis in the ectrodactyly-ectodermal dysplasia-clefting syndrome. Histologic, scanning electron-microscopic and biophysical studies of hair.

Several clinical syndromes are characterized by ectodermal dysplasia (ED) in association with clefting of the lip and/or palate. In these syndromes, alopecia is primarily due to abnormalities of the hair shaft associated with increased hair fragility. Scalp dermatitis is yet another peculiar finding, primarily seen in the ankyloblepharon-ED-clefting (AEC) syndrome. We report on a 16-year-old patient with ectrodactyly-ED-clefting (EEC) syndrome, who exhibited a scarring alopecia due to deep folliculitis. On scanning electron microscopy, irregular torsion and longitudinal grooving of the hair shaft (pili torti et canaliculi) were observed. Quantitative determinations of the elastic and viscous parameters of hair demonstrated a normal viscosity but a significantly reduced hair elasticity, indicating either an abnormal composition or a disordered arrangement of microfibrils within the apparently normal keratin matrix. In contrast to the erosive scalp dermatitis of early onset in the AEC syndrome, alopecia in this case of EEC syndrome demonstrated follicular scarring with onset during puberty. We question a possible role of the anatomical hair abnormality in the pathogenesis of chronic deep folliculitis in this and clinically related syndromes.

Adolescent↗
PubMed1990

Mineralization of collagen and elastic fibers in superficial dystrophic cutaneous calcification: an ultrastructural study.

The ultrastructural morphology of localized skin calcifications without associated diseases and with normal serum calcium and phosphate ion values is still unknown. In a case of superficial dystrophic calcinosis cutis (DCC), the role of collagen, elastin and ground substance in the process of calcification and the organization of the apatite crystals could be studied by light and electron microscopy despite technical difficulties in sectioning the hard tissue. Ultrastructural investigation revealed the nucleation of calcification being related to collagen and elastic fibers. No intracellular calcification was found. A flower-like arrangement of pleomorphic crystals was found around single collagen fibrils resembling the calcification of collagen seen in bone tissue. The elastic fibers showed a different pattern of calcification compared with other diseases (e.g. pseudoxanthoma elasticum) with known calcification of the elastic fibers. The process of mineralization was initially linked to the microfibrils of the elastic fiber.

Adult↗
PubMed1980

Structure of trabeculated detrusor smooth muscle in cases of prostatic hypertrophy.

The light and electron microscopic structure of biopsy samples of trabeculated urinary bladder from patients with proven outlfow obstruction due to prostic hypertrophy has been compared with the morphology of control bladder specimens. In the latter the detrusor muscle bundles were composed of smooth muscle cells closely packed together with very little intervening connective tissue. In contrast, irrespective of age, detrusor muscle from trabeculated bladders contained many muscle bundles in which the constituent cells were of relatively small diameter and were widely separated from each other by dense masses of connective tissue. No morphological evidence for smooth muscle hypertrophy or hyperplasia was obtained in the present study. In the electron microscope the connective tissue between the smooth muscle cells of trabeculated bladders was seen to contain, in addition to collagen fibrils, an extensive meshwork of electron-dense microfibrils apparently in continuity with the basal laminae of the smooth muscle cells. Regions of close approach between smooth muscle cells were seemingly unaffected by trabeculation as was the distrubution and fine structure of autonomic nerve terminals. These observations are intended to form a baseline for comparision with the results of future morphological studies of trabeculation arising in response to different aetiological factors.

Aged↗