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PubMed1977

Preponderance of lysosomal bodies in cultured fibroblasts from patients with recessive epidermolysis bullosa dystrophica. An electron microscopic study.

Fibroblasts of skin explants from three normal men and six patients with recessive epidermolysis bullosa dystrophica (EBD-R) were cultured in Dulbecco's medium, grown to confluence, sectioned and studied with the electron microscope. The normal control fibroblasts from the 6th to 13th passage (secretory phase) showed irregular or lobed nuclei with centrally scattered chromatin. They also had prominent RER, Golgi complexes, variously shaped mitochondria and cytoskeletal microfibrils. Their peripheral cytoplasm exhibited many vacuoles and a small number of these were autophagic lysosomes. In addition to the ultrastructural features described in the control fibroblasts, the EBD-R cells from the 6th passage contained remarkable numbers of strongly electron dense lysosomal bodies through their entire cytoplasm with very few empty vacuoles. It is speculated that the accumulation of these lysosomes may be connected with a primary metabolic cellular defect in the dermal fibroblasts of patients with EBD-R akin to that described in mucopolysaccharide storage diseases.

Adult↗

PubMed1979

Juvenile dermatitis herpetiformis: an immunoelectron microscopic study.

Three children with persistent maculopapular and urticarial lesions and vesicles at the predilection sites of dermatitis herpetiformis (DH) were shown to exhibit typical granular, papillary IgA and C3 deposits in the tips of the dermal papillae, as demonstrated by direct immunofluorescence. By immunoelectron microscopy, the IgA deposits were associated with the microfibrils of the elastic fibres as has been described in DH of the adult. C3 deposits were scattered throughout the papillary dermis. Despite the similarity of the clinical appearance, history with regard to gluten sensitive enteropathy (GSE) varied in these three cases. In one child, the skin lesions appeared following faults in the gluten free diet on which he was kept for coeliac disease. Another child developed the skin lesions during a gluten free diet which was not strictly followed; no recurrences of gastrointestinal symptoms accompanied the eruption of DH. In the third case, no evidence for GSE in patient's history or in jejunal biopsies was present at the time of onset of DH.

Celiac Disease↗

PubMed1981

Pili annulati: electron histochemical studies on affected hairs.

In this study we have shown that in pili annulati all the normal layers within each cuticle cell are present, and show a normal distribution of cystine. The presence of well ordered macrofibrils, composed of microfibrils embedded in a cystine rich matrix, in both regions of the hair shaft indicates that normal keratinization can and does take place. We have demonstrated the presence of electron-opaque, cystine positive material at the intermacrofibrillar spaces and suggest that the presence of the cortical holes is in part due to insufficient cortical material to occupy the space available, and in part due to the dissolution of the intermacrofibrillar material, possibly by water of other chemical agents, diffusing through an apparently more permeable cuticle.

Cystine↗

PubMed1993

Monilethrix: a clinicopathological illustration of a cortical defect.

We describe two sisters aged 2 and 7 years, with monilethrix. The older sister was clinically less severely affected but, microscopically, the features of weathering and alternating nodes and internodes were more obvious. The younger girl had more severe alopecia, with shorter hair, but the microscopic features were less marked. Scanning-electron microscopy demonstrated only slight cuticular weathering in both cases, and evidence of breakage in the cuticle at points of no obvious cuticular pathology. Transmission-electron microscopy showed normal cuticle cells in cross-section, but an abnormal cortex. The abnormalities included areas of homogeneous non-fibrillar material, and a deviated axis of some microfibrils. We consider that these findings support the possibility that a cortical defect contributes significantly to the fragility of hair in monilethrix. This might explain why hair with marked beading can be stronger than hair from an affected sibling with less apparent abnormality.

Child↗

PubMed1981

Monoclonal antibody to human platelet glycoprotein I. II. Effects on human platelet function.

The effect on platelet function of a monoclonal platelet antibody to platelet membrane glycoprotein I was tested. This antibody, AN51, inhibited ristocetin or bovine factor VIII-induced aggregation but did not modify ADP, collagen type I or type III, thrombin or arachidonic acid induced aggregations. Furthermore, the adhesion-aggregation of platelets induced by microfibrils was also inhibited by the antibody. Platelet adhesion to rabbit aorta subendothelium was impaired by the antibody. The persistent adhesion of platelets to collagenase-treated subendothelium was also inhibited. These findings strongly suggested that platelet membrane glycoprotein I could interact with a non-collagenic microfibrillar component of subendothelium. The binding of factor VIII/von Willebrand factor to platelet membrane in the presence of ristocetin was decreased in the binding site for factor VIII/von Willebrand factor to allow platelet adhesion to subendothelium.

Antibodies, Monoclonal↗

PubMed1977

Oxytalan fibre formation in the cornea: a light and electron microscopical study.

Oxytalan is a fibrillar protein possessing some of the staining and ultrastructural properties of developing elastic tissue. In a study of human corneae we failed to find fibres of this type in five normal specimens but found them in each of 16 examples of keratoconus and 13 cases of post-traumatic or post-inflammatory scarring. In two cases the microfibrillar nature of the deposits was confirmed by electron microscopy, individual microfibrils measuring 10-12 nm in diameter and having profiles suggestive of a tubular structure. Oxytalan formation was intimately associated with the basal lamina of the covering epithelium with, in areas showing disruption of Bowman's layer and scarring, some extension into the superficial collagenous stroma.

Cicatrix↗

PubMed1992

Analysis of the calcium distribution in predentine by EELS and of the early crystal formation in dentine by ESI and ESD.

Predentine is a collagen-rich extracellular matrix between the odontoblasts and the dentine with a width of about 15-20 microns. Electron energy-loss spectroscopy of rat incisors shows a significantly higher calcium content in the predentine at the predentine-dentine border than in the middle region of the predentine. At the predentine-dentine border in the dentine, the calcium and the phosphate groups combine to form apatite crystallites. Electron spectroscopic diffraction with zero-loss filtering revealed that the earliest crystallites contain only Debye-Scherrer rings of apatite, which are fewer in number and more diffuse than the diffraction rings from the mature crystallites. We therefore conclude that the early crystallites still contain lattice defects, which are annealed out to some degree with crystal growth. Electron spectroscopic imaging with zero-loss filtering also showed that the earliest crystallites are chains of dots (or small islands); they build up strands composed of islands, which rapidly acquire a needle-like character and coalesce laterally to form ribbon-or plate-like crystallites. The parallel strands sometimes appear to reinforce the macroperiod of the collagen microfibrils (67 nm) by tiny holes without any crystal-substance lined up perpendicular to the parallel strands of the crystallites.

Animals↗

PubMed2004

The irregular xylem 2 mutant is an allele of korrigan that affects the secondary cell wall of Arabidopsis thaliana.

The irregular xylem 2 (irx2) mutant of Arabidopsis thaliana exhibits a cellulose deficiency in the secondary cell wall, which is brought about by a point mutation in the KORRIGAN (KOR) beta,1-4 endoglucanase (beta,1-4 EGase) gene. Measurement of the total crystalline cellulose in the inflorescence stem indicates that the irx2 mutant contains approximately 30% of the level present in the wild type (WT). Fourier-Transform Infra Red (FTIR) analysis, however, indicates that there is no decrease in cellulose in primary cell walls of the cortical and epidermal cells of the stem. KOR expression is correlated with cellulose synthesis and is highly expressed in cells synthesising a secondary cell wall. Co-precipitation experiments, using either an epitope-tagged form of KOR or IRX3 (AtCesA7), suggest that KOR is not an integral part of the cellulose synthase complex. These data are supported by immunolocalisation of KOR that suggests that KOR does not localise to sites of secondary cell wall deposition in the developing xylem. The defect in irx2 plant is consistent with a role for KOR in the later stages of secondary cell wall formation, suggesting a role in processing of the growing microfibrils or release of the cellulose synthase complex.

Alleles↗

PubMed1988

The elastic tissue of the skin. A comparison of spontaneous and actinic (solar) aging.

In order to separate the changes of actinic damage from those of simple aging, we studied the elastic fibers in low and high sun-exposed skins of normal subjects at different ages. Low sun-exposed skin shows chronologic aging lesions only. These begin at age 30 with a disappearance of oxytalan fibers and with some abnormalities in the reticular and deep dermis; at age 40, aging changes are established: no oxytalan fibers, marked abnormalities, and lysis of elaunic and elastic fibers. In high sun-exposed skin, age-related lesions also occur but are associated with more or less precocious elastotic degeneration in reticular and deep dermis. Both types of aging fibers are revealed by the antielastin antibody HB 8, disappear with elastase, but resist collagenase. Actinic elastosis clearly originates from elastin. The two types of change differ in electron microscopic appearance: with spontaneous aging, elastic fibers are disintegrated (loose and porous fibers); in actinic damage, elastotic fibers are thicker and have accentuated microfibril dense masses. The age-associated lesions could be due to the activity of protease of fibroblastic origin whereas the elastotic degeneration is probably due to the actinic stimulation of fibroblasts.

Adult↗

PubMed1986

Electrostatic effects and the dynamics of enzyme reactions at the surface of plant cells. 1. A theory of the ionic control of a complex multi-enzyme system.

A theory is proposed to explain the physical bases of the ionic control of the activity of an enzyme system, located on a plant cell surface, and probably involved in cell-wall synthesis and extension. The model, which is based on various previously published experimental results, involves several assumptions: a cell-wall pectin methyl esterase de-esterifies pectins and thus creates the fixed negative charges of the cell wall; various enzymes incorporate uncharged carbohydrates in cell-wall material; cell-wall extension implies the sliding of cellulose microfibrils; the enzymes responsible for carbohydrate incorporation are activated by protons in the pH range 4-8 and have very similar pH dependencies: the cell-wall pectin methyl esterase is inhibited by protons in the same pH range. The mathematical derivation of this model, written in the form of a hypercycle, indicates that it is equivalent to a set of two antagonistic enzyme reactions: an enzyme reaction conditioned by pectin methyl esterase which results in the increase of fixed charge density of the cell wall; a number of 'growth enzymes', which produce extension and building up of the cell wall and therefore a decrease of charge density. The mathematical study of this model shows it may display a very high co-operativity of its response to slight changes of pH. This cooperativity means that the cell wall charge density may dramatically increase or decrease, within a very narrow pH range. The steep response of this system appears to be the direct consequence of different pH sensitivities of pectin methyl esterase and of the other cell-wall enzymes involved in cell growth. Calcium, which tightly binds to the cell wall, may diminish or even suppress this abrupt charge transition. This model suggests a novel theory of the ionic control of cell-wall expansion. The very basis of this theory is the existence of an electrostatic potential difference, delta psi, between the inside and the outside of the cell wall. When this delta psi value is large, the local proton concentration is high. Therefore the enzymes involved in cell wall extension and building up are active, but pectin methyl esterase is not. Therefore, the cell wall extends and the charge density decreases. The delta psi value then declines, as well as the local proton concentration. Under these conditions, the pectin methyl esterase becomes activated, whereas the 'growth enzymes' are not. This activation of pectin methyl esterase restores the initial, or an even higher, electrostatic potential difference, which in turn results in a decrease of local pH.(ABSTRACT TRUNCATED AT 400 WORDS)

Calcium↗

PubMed1992

Stable expression of chicken type-VI collagen alpha 1, alpha 2 and alpha 3 cDNAs in murine NIH/3T3 cells.

As a component of an extensive network of microfibrils interwoven with large collagen fibers and in close contact with cell surfaces, type VI collagen plays an important role in cell-matrix interactions. To investigate the behaviour of chicken type VI collagen chains in heterologous host cells as a means to understanding the pattern of assembly of this collagen, we transfected murine NIH/3T3 cells with cDNAs encoding chicken alpha 1(VI), alpha 2(VI) and alpha 3(VI) chains. Cell lines that constitutively expressed the individual chains were analyzed by metabolic labeling and immunoprecipitation with specific antibodies. No self-association was observed for either alpha 1(VI) or alpha 2(VI) chains which were secreted as monomeric polypeptides. Furthermore, neither the chicken alpha 1(VI) nor alpha 2(VI) chains associated with the endogenous murine chains to form chimeric chicken/murine heterotrimers. In contrast, chimeric chicken/murine heterotrimers were detected in cell lines transfected with chicken alpha 3(VI) cDNA. These chimeric forms appeared to be properly aligned since their triple helices were stable to pepsin digestion. In addition, the chimeric heterotrimers coassembled and gave rise to disulfide-linked type VI collagen molecules.

3T3 Cells↗

PubMed1994

Characterization of a 100-kDa heat-stable microtubule-associated protein from higher plants.

In higher-plant cells, the different cell-cycle-dependent microtubule arrays are involved in a wide range of activities including chromosome segregation, cell-plate formation and cellulose microfibril distribution and orientation. A wealth of data, obtained using animal cells, has indicated that the differential stability and function of microtubules during cell-cycle and/or differentiation could be primarily regulated by selective microtubule-associated proteins (MAP). Compared to animal MAP, our knowledge of plant MAP is so far very limited. In this study, we have identified a maize heat-stable protein with apparent molecular mass 100 kDa (P-100) which binds to taxol-stabilized neurotubules and copolymerizes in vitro with purified neural tubulin. Moreover, P-100 cross-reacts with affinity-purified tau antibodies like a maize 83-kDa putative MAP described previously [Vantard, M., Schellenbaum, P., Fellous, A. & Lambert, A. M. (1991) Biochemistry 30, 9334-9340]. Polyclonal antibodies directed against P-100 were obtained and indicated that this protein is found in diverse higher-plant cultured cells suggesting the ubiquitous nature of this protein. P-100 can be phosphorylated in vitro by protein kinases present in a maize cytosol extract. Together, our data suggest that P-100 could be a higher plant MAP.

Blotting, Western↗

PubMed1983

Ultrastructural cytochemical demonstration of elastin in the matrix of salivary gland tumors.

Following light microscopic survey of the incidence of elastic tissue in 80 salivary gland tumors, tissue samples from 14 pleomorphic adenomas, three myoepitheliomas, and eight adenoid cystic carcinomas were processed for cytochemical demonstration of elastin with the tannic acid stain for ultra-thin sections. For comparative study, some other tumor types devoid of elastic tissue at the light microscopic level and non-neoplastic submandibular glands were also investigated. Elastic deposits of varying amounts were clearly revealed on the basal-lamina-like material and/or masses of microfibrils in the matrix close to the neoplastic myoepithelium and, to a lesser degree, immediately beneath the non-neoplastic myoepithelium. None of the other tumor types without myoepithelial differentiation contained elastic deposits closely associated with the neoplastic cells. Intimate topographical relationship of such as immature elastic fiber or developing elastic tissue to the neoplastic myoepithelial cells strongly indicated the primary origin of elastic components from these cells. It is postulated that the potential of salivary tumor cells to produce elastin is regarded as an indicator of their myoepithelial nature or differentiation.

Adenoma↗

PubMed1984

Cardiovascular lesion of carcinoid syndrome. An autopsy case of bronchial carcinoid.

An autopsy case of a 67-year-old Japanese male is presented. He had been suffering from carcinoid syndrome for 5 years and showed a typical picture of carcinoid heart disease. In Japan, carcinoid heart disease is rare and we can find only four reported cases (33% of reported carcinoid syndrome). The patient had high urinary secretion of 5-HIAA and high serum serotonin, and finally he died of heart failure and bronchopneumonia. The primary site of this carcinoid tumor was of the bronchus of the right B10c , and it had large hepatic metastases. Electronmicroscopically, the tumor cells had secretory granules measuring 1500-3500 A in diameter. Immunohistochemically, the tumor cells were markedly positive for human chorionic gonadotropin (hCG) and antidiuretic hormone (ADH) and positive for serotonin, in both the primary site and hepatic metastases. Characteristic fibrous plaques were detected in the right atrium, tricuspid valve, right ventricle, and left atrium. Electron-microscopically, the fibrous plaques consisted of smooth muscle cells and myofibroblasts surrounded by basement membrane-like material. The abundant matrix of the fibrous plaques contained acid mucopolysaccharide, microfibrils and collagen fibers. The same fibrous plaques were also found in hepatic veins. Furthermore, retroperitoneal fibrosis was present, which showed proliferation of myofibroblasts, fibroblasts and immature mesenchymal cells.

Aged↗

PubMed1987

High alkaline phosphatase activity of telangiectatic osteosarcoma (TOS) and its diagnostic significance.

Telangiectatic osteosarcoma (TOS) which occurred in the metaphysis of the right femoral bone in a 13-year-old female was reported. It showed osteolytic and cystic lesion without sclerotic change on roentgenogram and consisted histologically of various sized blood-filled spaces lined by layers of round to oval tumor cells in the thin fibrous septa. In some solid areas, a proliferation of atypical tumor cells with large prominent nucleoli was evident, embedded in the lace-like osteoid tissue. Mitotic cells were easily encountered. A large population of tumor cells revealed high alkaline phosphatase activity as well as 5'-nucleotidase activity, indicative of osteogenic cell origin. Ultrastructurally, they showed osteogenic characteristics of well-developed rough endoplasmic reticula, cytoplasmic microfibrils, and dense bodies, but not for those of endothelial cells. In this report, we suggest that alkaline phosphatase activity in biopsy and surgical specimens is useful for distinguishing TOS from other osteolytic bone tumors, with regard to its ontogenic discussion.

Adolescent↗

PubMed1993

Histogenesis of abnormal elastic fibers in blebs and bullae of patients with spontaneous pneumothorax: ultrastructural and immunohistochemical studies.

Elastic fibers in 15 blebs and 17 bullae with spontaneous pneumothorax were studied by means of electron microscopy and light and electron microscopic immunohistochemistry for elastin and alpha 1-antitrypsin. Blebs were formed in association with focal organized alveoli, and bullae were formed in association with pulmonary emphysema. Both blebs and bullae had abnormal elastic fibers. Ultrastructurally, abnormal elastic fibers of blebs and bullae consisted of accumulated thick and fine fibers. Accumulated thick elastic fibers showed vacuolar changes and electron-dense granular deposits, and they were associated with spiraling collagen fibrils. These thick elastic fibers reacted evenly with antielastin antibody and also reacted with anti-alpha 1-antitrypsin antibody. They are thought to be degraded elastic fibers. Accumulated fine elastic fibers consisted of bundles of microfibrils and granular amorphous components, and they reacted with anti-elastin and anti-alpha 1-antitrypsin antibody. These fine elastic fibers are thought to be not only newly formed in the process of organization but also degraded. It is suggested that elastic fibers of blebs and bullae are degraded due to an imbalance between elastase and alpha 1-antitrypsin.

Adult↗

PubMed1995

Evolution of three patterns of intra-alveolar fibrosis produced by bleomycin in rats.

In pulmonary fibrosis, it is known that fibrotic changes develop in the intra-alveolar spaces and that intra-alveolar fibrosis can be classified into three patterns, namely intra-alveolar buds, mural incorporation and obliterative changes. In order to clarify the evolution of intra-alveolar fibrosis, immunohistochemical studies of extracellular matrix proteins and electron microscopic observations were made of the lungs of rats given a single intratracheal instillation of bleomycin. All three patterns of fibrosis developed in this model. Intra-alveolar buds changed into globular lesions with dense collagen deposition, the surface of which was covered by alveolar epithelium. Electron microscopy revealed that the buds often contained spiraling collagen fibrils and numerous microfibrils, but not mature elastic fibres, beneath the regenerating epithelial lining cells; the epithelial basement membranes were discontinuous. In contrast, mural incorporation and obliterative changes were associated with alveolar structural remodeling. Electron microscopically, these lesions had bundles of normal collagen fibrils, small elastic fibers, and continuous epithelial basement membranes. These results indicate that: (i) intra-alveolar buds, that become intra-alveolar collagen globules, with an unusual extracellular matrix, do not contribute to alveolar structural remodelling; and (ii) areas of mural incorporation and obliterative changes have the usual type of extracellular matrix and are essential for alveolar structural remodelling.

Animals↗

PubMed1989

Fibrillary glomerulonephritis--a report of two cases.

Two patients with an uncommon form of glomerulonephritis are described. The main clinical features were hematuria and proteinuria associated with normal renal function. The glomerular lesions consisted of mesangial hypercellularity and capillary wall thickening. Immunofluorescence was positive for IgG and C3 in both cases. Widespread deposition of microfibrils (mean diameters 17.0 nm and 18.4 nm) within mesangial areas and capillary basement membranes was seen on electron microscopy. Congo red staining for amyloid was negative. In both patients there was no evidence of underlying disease or extra-glomerular involvement and hence the disorder appeared to represent a primary glomerulonephritis.

Adult↗