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PubMed1997

Exfoliation syndrome in a 17-year-old girl.

A 17-year-old girl with unilateral congenital glaucoma who had undergone trabeculectomy and peripheral iridectomy in infancy developed apparent exfoliation syndrome (XFS) in the eye that underwent the surgical procedures. A conjunctival biopsy was performed and the specimen was fixed in 2.5% glutaraldehyde, embedded in epoxy resin (Epon-Araldite, Electron Microscopy Sciences, Fort Washington, Pa), and processed for routine electron microscopy and immunostaining for elastin. Results of ultrastructural study showed scattered fibrillar aggregates compatible with those of XFS in an older adult, differing chiefly in sparsity of granular interfibrillar matrix. The XFS fibers were closely associated with elastic fibers and microfibrils. Elastosis of the actinic-aging type was somewhat greater than expected for age. To our knowledge, this is the youngest patient described with characteristic ocular findings of XFS to date, supporting others who have suggested an association between iris surgery in youth and early onset XFS. Electron microscopy was essential in ruling out the possibility of a clinically similar entity caused by ultrastructurally different material.

Adolescent↗
PubMed1996

Elastic fiber degeneration in Costello syndrome.

Clinical and pathological observations of a 6-month-old-boy with Costello syndrome are reported. The main clinical findings were loose skin of the neck, hands, and feet, deep palmar and plantar creases, typical "coarse" face with thick lips and macroglossia, relative macrocephaly, mental retardation, short stature, arrhythmia, large size for gestational age, and poor feeding. At age 6 months he died of rhabdomyolysis. The major pathological findings were fine, disrupted, and loosely-constructed elastic fibers in the skin, tongue, pharynx, larynx, and upper esophagus, but not in the bronchi, alveoli, aorta, or coronary arteries. Hyperplasia of collagen fibers in the skin, hyperplasia of the mucous glands in the bronchus, narrowing of the pulmonary artery, degeneration of the atrial conduction system, calcification and ballooning of skeletal muscle fibers with infiltration of macrophages, and myoglobin depositions in the collecting ducts in the kidney were also observed. The degeneration of elastic fibers was confirmed in the skin of a second Costello syndrome patient. Expression of elastin mRNA in the patient's fibroblasts was normal in size and amount. Given that elastic fiber degeneration was observed in the tissues with clinical symptoms, we speculate that a defect of elastic fibers, possibly relating to alternative splicing in the elastin gene or to defects in elastin microfibrils, might be involved in the pathogenesis of Costello syndrome.

Abnormalities, Multiple↗
PubMed1996

Weill-Marchesani syndrome--possible linkage of the autosomal dominant form to 15q21.1.

Weill-Marchesani syndrome comprises short stature, brachydactyly, microspherophakia, glaucoma, and ectopia lentis is regarded as an autosomal recessive trait (McKusick 277600). We present two families each with affected individuals in 3 generations demonstrating autosomal dominant inheritance of Weill-Marchesani syndrome. Linkage analysis in these 2 families suggests a gene for Weill-Marchesani syndrome maps to 15q21.1. The dislocated lenses and connective tissue disorder in these families suggests that fibrillin-1 and microfibril-associated protein 1, which both map to 15q21.1, are candidate genes for Weill-Marchesani syndrome. Immunohistochemistry staining of skin sections from family 1 showed an apparent decrease in fibrillin staining compared to control individuals.

Abnormalities, Multiple↗
PubMedDate not supplied

Structural studies on polymer whiskers by transmission electron microscopy: I. Morphological and high-resolution observations.

The structures of poly(p-hydroxybenzoic acid) (PHBA) whisker crystals and crystalline fine fibrils of copolymer prepared from p-hydroxybenzoic acid (HBA) and 2-hydroxy-6-naphthoic acid (HNA), namely poly(HBA/HNA) (monomer molar ratio: 97/3), were investigated by transmission electron microscopy (TEM). As for a PHBA whisker, microfibril-like bright regions were recognized in the 210 dark-field image. In the high-resolution TEM image of another PHBA whisker, however, lattice fringes were continuous through the whisker, showing that the whisker is highly crystalline and almost perfect. On the other hand, in the high-resolution images of poly(HBA/HNA) fine fibrils, granular crystallites (20-40 nm in lateral dimension) were observed. The lattice fringes in the crystallites were not successfully indexed with the orthorhombic unit cells of the homopolymer crystal, suggesting the coexistence of another different structure as a minor component.

Crystallization↗
PubMed1997

Elastic system of the rat ventral prostate and its modifications following orchiectomy.

BACKGROUND: The extracellular matrix (ECM) has important roles in prostatic development, and marked stromal changes take place in the rat ventral prostate (VP) after androgen deprivation. However, little knowledge exists about individual ECM components. METHODS: The distribution of elastic fibers (EF) and elastic-related fibers (ERF) in the VP of castrated and control rats was investigated, using histochemistry and transmission electron microscopy (TEM). RESULTS: EF are barely detected in the prostatic stroma, but ERF are relatively abundant. Castration results in a relative increase in the number and thickness of ERF. TEM showed an open network of ECM microfibrils throughout, the stroma and thin and short EF, which increase in number and thickness after orchiectomy. CONCLUSIONS: The presence of elastic system components in the rat VP warrants the deformability required for the secretion exclusion under the action of smooth muscle cells, and the castration-induced modification may be related to the contraction of the tissue and maintenance of peculiar arrangements of other ECM components.

Animals↗
PubMed1997

Signet-ring sinus histiocytosis: a reactive disorder that mimics metastatic adenocarcinoma.

BACKGROUND: Signet-ring sinus histiocytosis is a rare and distinctive reactive disorder recently observed in the axillary lymph nodes of patients with breast carcinoma. This form of sinus histiocytosis closely resembles and can easily be confused with metastatic adenocarcinoma. METHODS: To determine the incidence of this reactive process in lymph nodes from different anatomic sites, broaden its morphologic spectrum, and discuss the differential diagnosis, the authors examined lymph nodes from 316 radical prostatectomy specimens, 184 modified radical mastectomy specimens, 108 colectomy specimens, 57 gastrectomy specimens, and 27 radical hysterectomy specimens. These surgical procedures were performed to treat carcinoma of the prostate, breast, colon, stomach, and uterine cervix, respectively. A total of 9741 lymph nodes were histologically examined. The lymph nodes containing sinus signet-ring cells were stained with mucicarmine, Alcian blue, and periodic acid-Schiff stains (PAS). Immunostains for epithelial, lymphoid, and histiocytic markers were also performed. In two cases, tissue was retrieved from the paraffin block and subsequently processed for electron microscopic examination. RESULTS: Only 4 of 316 radical prostatectomy specimens (1.2%) and 2 of 184 axillary dissections (1.08%) contained lymph nodes with signet-ring sinus histiocytosis. Of 9741 lymph nodes reviewed, 37 (24 pelvic and 13 axillary lymph nodes) had signet-ring sinus histiocytosis, for an incidence of 0.38%. Microscopically, the signet-ring histiocytes lacked nuclear atypia and were mucin negative. In two cases, clusters of histiocytes with rounded, eosinophilic, diastase resistant, PAS positive cytoplasmic globules were observed. Both types of signet-ring cells showed reactivity for histiocytic markers and were negative for cytokeratin and lymphoid markers. By electron microscopy, most histiocytes were shown to have a large empty vacuole that displaced the nucleus. Granular material was observed in some of the vacuoles. Some histiocytes exhibited a rounded cytoplasmic body composed of central electron dense, granular material and a rim of microfibrils. No lipid droplets were identified. CONCLUSIONS: Signet-ring sinus histiocytosis is a rare and distinctive reactive disorder found incidentally in the pelvic and axillary lymph nodes of patients with carcinoma of the prostate and breast, respectively. Although this histiocytic reaction mimics metastatic adenocarcinoma and signet-ring cell lymphoma, it can be identified by careful cytologic analysis together with positive reactivity for histiocytic markers, negative mucin stains, and lack of reactivity for epithelial and lymphoid markers. The etiology and pathogenesis of this unusual form of sinus histiocytosis remains unclear.

Adenocarcinoma↗
PubMed1997

In vitro assembled plant microtubules exhibit a high state of dynamic instability.

Higher plants possess four distinct microtubule arrays. One of these, the cortical array, is involved in orienting the deposition of cellulose microfibrils. This plant interphase array is also notable because it contains exceptionally dynamic microtubules. Although the primary sequence of plant and animal tubulin is similar (79-87% amino acid identity overall) there are some regions of divergence. Thus, one possible explanation for the high state of polymer assembly and turnover that is observed in plant interphase arrays is that the tubulins have evolved differently and possess a higher intrinsic dynamic character than their animal counterparts. This hypothesis was tested using highly purified plant tubulin assembled in vitro. Using high-resolution DIC video-enhanced microscopy, we quantified the four characteristic parameters of dynamic instability of plant microtubules and compared them with animal microtubules. The elongation velocities between plant and animal microtubules are similar, but plant microtubules undergo catastrophes more frequently, do not exhibit any rescues, and have an average shortening velocity of 195 microm/min (compared with 21 microm/min for animal microtubules). These data support the hypothesis that plant tubulin forms microtubules that are intrinsically more dynamic than those of animals.

Animals↗
PubMed2000

Extracellular matrix of the human aortic media: an ultrastructural histochemical and immunohistochemical study of the adult aortic media.

Aortic distensability is the key to normal aortic function and relates to the lamellar unit in the media. However, the organization of the extracellular matrix components in these lamellar units, which are largely responsible for the distensability, is insufficiently known, especially in the human. We therefore performed a detailed ultrastructural analysis of these components. Thoracic aortas of 56 individuals (age 45-74 years), none of whom suffered from aortic disease, were studied by immunoelectron microscopy of elastin, collagen types I, III, IV, V, and VI, fibronectin, and fibrillin-1, and by ultrastructural histochemistry of proteoglycans, which were further characterized by enzymatic digestion. The elastic lamellae were closely associated with thick collagen fibers containing types I, III, and V collagen. Between these collagen fibers, numerous complex, circumferentially oriented streaks of elastin protruded from the lamellae. In contrast to what is usually reported in the aortas of experimental animals, the smooth muscle cells preferentially adhered to these ill-defined streaks rather than directly to the solid lamellae. Fibrillin-1- and type VI collagen-containing bundles of microfibrils (oxytalan fibers) were also involved in the smooth muscle cell-elastin contact. The smooth muscle cells were invested by basal lamina-like layers connecting them to each other as well as to the oxytalan fibers. Unexpectedly, these layers were abundantly labeled by anti-fibronectin, whereas type IV collagen, a specific basement membrane component, was mainly found in larger, flocculent deposits. The proteoglycans present were collagen-associated dermatan sulfate proteoglycan, cell-associated heparan sulfate proteoglycan, and interstitial chondroitin sulfate proteoglycan. Our observations demonstrate that the extracellular matrix in the human aorta is extremely complex and therefore differs from most descriptions based on experimental animals. They serve as reference for future studies on aortic diseases, such as aneurysmas and dissections.

Aged↗
PubMed1996

Expression and distribution of two alternatively spliced transcripts from the chicken alpha 2 (VI) collagen gene.

Two types of mRNA molecules with different 3' ends are transcribed from the chicken alpha 2(VI) collagen gene. The major splice variant encodes a polypeptide with a von Willebrand factor A domain at its carboxyl terminus. In the minor splice variant, this A domain is replaced by a novel motif which reveals some similarity to a fibronectin type III repeat. In situ hybridization experiments demonstrate that the major transcript is ubiquitously expressed. Substantial amounts are found in skeletal and cardiac muscle, gizzard, skin, tendon, liver, the wall of blood vessels, and the connective tissue of peripheral nerves. In contrast, the minor transcript is expressed at a very low level and can hardly be detected in any tissue by in situ hybridization. Only the aortic wall contains a considerable amount of this splice variant. However, no difference is observed by Northern blotting and the polymerase chain reaction in the ratio of the two transcripts when aorta and the other tissues are compared. Thus, the minor splice variant is not expressed in a tissue specific manner and, consequently, it is unlikely that it plays a tissue specific role. It might rather serve a general function in the structure and assembly of type VI collagen microfibrils.

Alternative Splicing↗
PubMed1997

Fibrillin-1 mutations in Marfan syndrome and other type-1 fibrillinopathies.

Fibrillin is the major component of extracellular microfibrils and is widely distributed in connective tissue throughout the body. Mutations in the fibrillin-1 (FBN1) gene, on chromosome 15q21.1, have been found to cause Marfan syndrome, a dominantly inherited disorder characterised by clinically variable skeletal, ocular, and cardiovascular abnormalities. Fibrillin-1 mutations have also been found in several other related connective tissue disorders, such as severe neonatal Marfan syndrome, dominant ectopia lentis, familial ascending aortic aneurysm, isolated skeletal features of Marfan syndrome, and Shprintzen-Goldberg syndrome. Mutations are spread throughout the gene and, with the exception of neonatal Marfan syndrome, show no obvious clustering or phenotypic association.

Connective Tissue Diseases↗
PubMed1998

Cellulose powder from Cladophora sp. algae.

The surface are and crystallinity was measured on a cellulose powder made from Cladophora sp. algae. The algae cellulose powder was found to have a very high surface area (63.4 m2/g, N2 gas adsorption) and build up of cellulose with a high crystallinity (approximately 100%, solid state NMR). The high surface area was confirmed by calculations from atomic force microscope imaging of microfibrils from Cladophora sp. algae.

Cellulose↗
PubMed1976

Ultrastructure of elastosis in scirrhous carcinoma of the breast.

The stroma of scirrhous breast carcinoma frequently contains an abundance of material with the histologic staining properties of elastic tissue referred to as elastosis. In the present study, this lesion was found to correspond at the ultrastructural level to elastic fibers of various sizes and random orientation. These fibers displayed the two characteristic components, consisting of an amorphous core with a peripheral mantle of microfibrils. Interspersed among the elastic fibers were modified fibroblasts. These cells exhibited an irregular contour with numerous cytoplasmic processes and indentations. Their cytoplasm contained abundant rough endoplasmic reticulum, prominent Golgi complexes, and bundles of filaments. In the extracellular space, elastic fibers were often closely apposed to the plasma membrane of the fibroblasts. Carcinoma cells were also observed in the elastic tissue. It is postulated that fibroblasts, probably under an inductive influence from cancer cells, are the cells responsible for elastic production.

Adenocarcinoma, Scirrhous↗
PubMed1976

Ultrastructure of the basal cell adenoma of parotid gland.

Electron microscopic examination of two classical examples of so-called basal cell adenoma of parotid gland disclosed four distinct cellular types: the squamous epithelial cells with tonofilaments and prominent desmosomes predominantly located at the central portion of neoplastic mass; the basally located secretory cells with numerous secretory granules; the occasional intermediate cells with scanty cytoplasmic microfilaments; and the peripherally situated attenuated myoepithelial cells. The neoplastic clusters are surrounded by highly replicated basal laminae with microfibrils in their interstices. This information about its component cells suggests that basal cell adenoma arises from the secretory duct, in particular the intercalated duct, of the parotid gland. The term basal cell adenoma appears appropriate for its designation. It is interesting that the secretory cells and the multilayered basal laminae illustrated in the present study are reportedly seen in adenoid cystic carcinoma of the salivary gland; this finding would suggest a common cellular origin for these two neoplasms.

Adenoma↗
PubMed1976

Epithelioid sarcoma: case report with ultrastructural review, histogenetic discussion, and chemotherapeutic data.

A case of abdominal wall epithelioid sarcoma, studied by light and electron microscopy over a 3-year period, is presented. Ultrastructurally, there appear to be two types of tumor cells, light and dark, which differ by virtue of a heavier concentration of microfibrils and dilated rough endoplasmic reticulum in the dark cells. Both tumor cell types contain prominent Golgi systems, abundant free ribosomes, and numerous pinocytotic vesicles. The ultrastructural characteristics of the tumor cells resembel those of epithelioid cells of experimental human granulomas, as well as those of normal human synovium. A multifaceted relationship between histiocytes and synovial cells is demonstrated and it is concluded that the tumor is probably derived from mesenchymal reserve cells capable of differentiating a long histiocytic or synovial lines. Preliminary chemotherapeutic data are reviewed.

Abdominal Muscles↗
PubMed1977

Elastosis and other stromal reactions in benign and malignant breast tissue: an ultrastructural study.

The stroma and stromal reaction in normal breast, benign, and malignant breast tissue was studied by electron microscopy. Elastosis is the main stromal response in infiltrating duct and lobular carcinomas. Medullary carcinoma elicits no significant elastosis but intraductal carcinoma has significant local elastosis. Benign conditions such as fibroadenoma and sclerosing adenosis produced no significant elastosis. The high number of elastic fibers and the high microfibril:elastin ratio indicate that most of the elastic fibers are recently secreted, probably by fibroblasts and myofibroblasts. The factors stimulating the increased production of elastic fibers and the prognostic significance of elastosis remain unclear.

Adenofibroma↗
PubMed1978

Amyloid stroma in a tubular carcinoma of palatal salivary gland: a histochemical and ultrastructural study.

Amyloid as defined by positive Congo red green birefringence and STB red birefringence was observed in the stroma of a tubular carcinoma of minor salivary gland origin. The amyloid exhibited additional histochemical characteristics of immunamyloid, viz., positive DMAB-nitrate and DC-reactions and spontaneous autofluorescence. Electron microscopic studies of the epithelial tumor cells displayed large amounts of cytoplasmic microfilaments similar to those present in the extracellular amyloid masses. It is suggested that the amyloid is derived from spontaneous assembly or polymerization of cytoplasmic microfibrils of the dying tumor cells as has been proposed for the amyloid associated with the calcifying epithelial odontogenic tumor (CEOT).

Adenocarcinoma↗
PubMed1981

A comparative ultrastructural study of chondrosarcoma, chordoid sarcoma, and chordoma.

A morphologic and electron microscopic study was made of two chordoid sarcomas. These lesions were compared with two classical chondrosarcomas and two chordomas. These chondrosarcoma cells showed many features common to chondrocytes, such as abundant RER, well-developed Golgi complexes, and microvillous cytoplasmatic membranes. The chordoid sarcomas bore a close morphologic resemblance to the chordomas but the ultrastructural features revealed a close relationship to the chondrosarcomas. The chordoid sarcoma and chondrosarcoma cells had scalloped cytoplasmatic membranes, variable amounts of glycogen, round or oval nuclei and microfibrils, collagen, and electron-dense granules in the ground substance. The chordoma was characterized by the presence of stellate and physalipherous cells, as well as many transitional cells, with varying nuclear morphology; dilated and irregular RER in contact with mitochondria and morphologically varied vacuoles are the main features in the cytoplasm. This study suggests that chordoid sarcoma represents a variety of the chondrosarcoma rather than a form of chordoma. These findings also support the suggestion of Weiss that chordoid sarcoma is an extraskeletal myxoid chondrosarcoma.

Cell Nucleus↗
PubMed1999

Autoantibodies to the extracellular matrix microfibrillar protein, fibrillin 1, in patients with localized scleroderma.

OBJECTIVE: Serum autoantibodies to fibrillin 1, the major component of microfibrils in the extracellular matrix, recently have been reported to occur in the tight skin mouse and in patients with systemic sclerosis, but not in patients with other connective tissue diseases. This study was undertaken to determine whether antifibrillin 1 antibodies could be detected in patients with localized forms of scleroderma. METHODS: Sera from 50 patients with localized scleroderma (27 with linear scleroderma and 23 with morphea) and 51 normal controls were tested for IgG and IgM antifibrillin 1 autoantibodies, using a radioimmunoassay (RIA) and a human recombinant fibrillin 1 protein (rFbn-1). RESULTS: Both in patients with linear scleroderma and in those with morphea, mean levels of IgM and IgG binding to rFbn-1 were significantly higher than in controls. Eight patients with linear scleroderma (30%) and 6 patients with morphea (26%) had IgG autoantibodies to fibrillin 1 (rFbn-1) by RIA, compared with 3 controls (6%) (P = 0.006 and P = 0.022, respectively). No correlations between antifibrillin 1 antibodies and active skin disease or antinuclear antibody positivity were found. CONCLUSION: Autoantibodies to fibrillin 1 occur in patients with both forms of localized scleroderma (linear scleroderma and morphea). The clinical and pathogenetic significance of this autoimmune response remains to be determined.

Autoantibodies↗