The ultrastructure of chondrocytes in the cartilage of Sepia officinalis and Octopus vulgaris (Mollusca, Cephalopoda).

Thin sections of cartilage from the chondrocranium of cuttle fish and octopus were examined using the transmission electron microscope. It was found that cephalopod chondrocytes differed considerably from the chondrocytes of vertebrate cartilage; in particular they possessed many long and ramifying cytoplasmic processes and had an ultrastructure typical of protein-secreting cells. They did not, however, contain secretory granules; while vesicles and rough endoplasmic reticulum cisternae seemed to open directly to the cell surface.

An ultrastructural study of cell junctions and the cytoskeleton in epithelial cells of the molluscan integument.

Cell junctions and the cytoskeleton of integumental epidermal cells from six bivalves, four gastropods, and two cephalopods were studied by transmission electron microscopy. In all species examined, the junctions in supporting cells presented the following similar pattern: an apical-lateral adhesion belt (occluding junctions were not observed); (b) a lateral complex of septate junctions and smooth septate junctions, with interdigitations between adjacent cells while the gap junctions were not constantly present, and a basal complex with hemidesmosomes, focal contacts, and sometimes basolateral adherent junctions. Desmosomes were never observed.

Immunocytochemical localization of protein p27BBP in human skin and invertebrate (Sepia officinalis) integument.

The protein p27BBP (alias eIF6) occurs in yeast and mammalian epithelial cells. It is essential for ribosome genesis and has also been implicated in the functionality of integrins and intermediate filaments. By immunoblot, we show that homogenized integument from Sepia officinalis (Cephalopoda, Mollusca) contains a protein with immunological properties that closely resemble those of p27BBP.

The cytoskeleton of chondrocytes of Sepia officinalis (Mollusca, Cephalopoda): an immunocytochemical study.

Our previous electron microscope study showed that chondrocytes from cephalopod cartilage possess a highly developed cytoskeleton and numerous cytoplasmic processes that ramify extensively through the tissue. We have now carried out a light microscope immunocytochemical study of chondrocytes from the orbital cartilage of Sepia officinalis to obtain indications as to the nature of the cytoskeletal components. We found clear positivity to antibodies against mammalian tubulin, vimentin, GFAP, and actin, but not keratin.

Collagen fibrils of an invertebrate (Sepia officinalis) are heterotypic: immunocytochemical demonstration.

Collagen fibrils from the dermis of Sepia officinalis were processed for immunoelectron microscopy to reveal reactions to antibodies against mammalian types I, III, and V, teleost type I and cephalopod type I-like collagens, by single and double immunogold localization. The fibrils were observed: (a) in suspensions of prepared fibrils, (b) in ultrathin sections of embedded fibril preparations, and (c) in ultrathin sections of dermal tissue. Some samples were subjected to acetic acid or urea dissociation.

Temperature-dependent, irreversible formation of amyloid fibrils by a soluble human ataxin-3 carrying a moderately expanded polyglutamine stretch (Q36).

The protein ataxin-3 is responsible for Machado-Joseph disease/spinocerebellar ataxia type 3, a neurodegenerative disorder caused by the presence of an expanded polyglutamine tract. A previous investigation [Bevivino, A. E.

An ultrastructural study of connective tissue in mollusc integument III. Cephalopoda.

We studied structure and ultrastructure of the subepidermal connective tissue (SEC) of the integument of three cephalopods (Sepia officinalis, Octopus vulgaris and Loligo pealii). In all species, three distinct regions of the SEC were recognised: (a) an outer zone (OZ) that included the dermal-epidermal junction, and consisted of a thin layer of connective tissue containing muscles, (b) an extensive middle zone (MZ) containing a compact network of collagen fibres and numerous cells, (c) an inner zone (IZ) of loose connective tissue that merged with muscular fascia. This arrangement differs from that in bivalves and gastropods and recalls vertebrate integument.

Immunohistochemical study of subepidermal connective of molluscan integument.

Sections of integument from gastropod, bivalve and cephalopod species were studied immunohistochemically to determine reactivity to antibody against the type I-like collagen from Sepia cartilage and antibodies against components of the extracellular matrix (ECM) of vertebrate connective tissue: type I, III, IV, V, and VI collagens, laminin, nidogen and heparan sulphate. All samples exhibited similar reactivities to the antibodies, although differences in the intensity and localization of the immunostaining were found that were clearly correlated with between-species differences in integumental ultrastructure. These findings indicate that the composition of the integumental ECM is similar in the three classes of molluscs examined and that several types of collagen are present.

A new collagen from the extracellular matrix of Sepia officinalis cartilage.

Guanidinium chloride treatment of Sepia officinalis cartilage solubilized a component that contained hydroxyproline. Electron-microscopy observation of rotary-shadowed preparations of this component revealed it to consist of rod-like units themselves consisting of filaments. Dialysis of an acetic acid solution against ATP afforded polymeric aggregates consisting of a succession of two or three thick sections showing transverse electron-opaque banding, separated by thinner sections without banding.

Electrophoretic and immunochemical study of collagens from Sepia officinalis cartilage.

Electrophoretic and Western blot studies were conducted on collagen fractions extracted from Sepia officinalis (cuttlefish) cartilage using a modified salt precipitation method developed for the isolation of vertebrate collagens. The antibodies used had been raised in rabbit against the following types of collagen: Sepia I-like; fish I; human I; chicken I, II, and IX; rat V; and calf IX and XI. The main finding was that various types of collagen are present in Sepia cartilage, as they are in vertebrate hyaline cartilage.

An ultrastructural study of connective tissue in mollusc integument: II. Gastropoda.

We studied the ultrastructure of the subepidermal connective tissue (SEC) in different zones of the integument in terrestrial, marine and freshwater gastropods (eight species). In all cases, the SEC was a layer of loose connective tissue between the basal membrane (BM) of the epidermis and the connective tissue of the deeper muscle layers. It was of monotonous structure and not differentiated into layers such as are found in mammalian dermis.

An ultrastructural study of connective tissue in mollusc integument: I. Bivalvia.

The ultrastructure of the subepidermal connective tissue (SEC) in different areas of the integument of the bivalves Callista chione, Pecten jacobaeus, Mytilus galloprovincialis and Ostrea edulis was studied by transmission electron microscopy. The main organisation of the SEC was broadly similar in all species: the SEC was connected to the epidermis by a basement membrane and merged directly with the deeper connective tissue surrounding muscles. The SEC was not differentiated into layers like the papillary and reticular dermis of mammals, however, the architecture, thickness and shape of the basement membrane varied from species to species, as well as within species (in the foot, central or marginal zones of the mantle).

Immunohistochemical study of collagens of the extracellular matrix in cartilage of Sepia officinalis.

We used various anti-collagen antibodies to perform indirect immunofluorescent staining of cartilage sections from cuttlefish (S. officinalis). On ultrathin sections and collagen fibril preparations from the same tissue, we performed immunostaining with colloidal gold.

Use of rotary shadowing electron microscopy to investigate the collagen fibrils in the extracellular matrix of cuttle-fish (Sepia officinalis) and chicken cartilage.

Collagen fibrils isolated from sternal cartilage of chick embryo and chondrocranium of cuttle-fish (Sepia officinalis) were examined with the electron microscope after rotary showing. The aim was to determine whether collagen fibrils from S. officinalis cartilage contained collagen molecules similar to the type IX collagen of vertebrate cartilage.

An ultrastructural study of the perichondrium in cartilages of the chick embryo.

The ultrastructure of perichondrial tissue of cartilage rudiments (metatarsus, tibiotarsus and sternum) of the chick embryo at various stages of development (H.H. stages 28-45) was investigated by transmission electron microscopy.

A comparative study of perichondrial tissue in mammalian cartilages.

The general organization, cellular and extracellular components, and structural variation of perichondrium have been studied in different mammalian cartilages by polarized light and transmission electron microscopy. The overall structure is that of a dense connective tissue composed of variable numbers of thin, stratified, closely-packed lamellae, themselves composed of closely-matted collagen fibres running in the plane of the cartilage surface, but oriented at various angles to each other. Variations mainly concern the arrangement of the fibre bundles in the transition zones between perichondrial and cartilage matrices, and between perichondrium and surrounding tissues.

A comparative microscopic and ultrastructural study of perichondrial tissue in cartilage of Octopus vulgaris (Cephalopoda, Mollusca).

The microscopic and submicroscopic structures of perichondrial tissues in the head cartilages of Octopus vulgaris were studied by polarized light and transmission electron microscopy. The orbital cartilages possess a birefringent layer parallel to the surface of the cartilage; ultrastructurally, this layer, which may be considered perichondrial tissue, has the typical organisation of connective tissue but does not possess the stratification of collagen laminae found in vertebrate perichondria. Perichondrial extracellular matrix is clearly distinct from that of cartilage because its collagen fibrils are of a larger diameter than collagen fibrils from cartilage.

The head cartilage of cephalopods. II. Ultrastructure of isolated native collagen fibrils and of polymeric aggregates obtained in vitro: comparison with the cartilage of mammals.

Native collagen fibrils were isolated from cephalopod head cartilage and mammal hyaline cartilage. The analysis with TEM after positive and negative staining demonstrated that the fibrils have a periodic structure similar to that of fibrillar type I collagen of mammals. The banding pattern of polymeric forms (SLS, FLS) obtained in vitro from squid cartilage collagen was remarkably different from the analogous forms of mammal collagen types I and II.

[Ultrastructural analysis of human ejaculate from infertile subjects].

It has been demonstrated that the semen of infertile patients contains at high percentage of abnormal forms and no clear answer has been so far provided to the questions of which malformations are compatible with male fertility, which malformations are responsible for the infertility and which is the percentage of defective cells that gives rise to infertility. In this study the eiaculates of 56 patients of suspected male infertility were used as material. The semen samples were fixed for 2 hr at room temperature in 4% glutaraldehyde in 0.

Subcellular localization of serotonin-immunoreactivity in the pedal ganglion of Mytilus galloprovincialis (Mollusca, Bivalvia).

Serotonin has been localized in neurons of the pedal ganglion of Mytilus galloprovincialis by means of colloidal gold immunostaining. Ultrastructural quantitative analysis shows that gold particles are concentrated over perikarya and fibers containing a unique vesicle population. The vesicles are round or elliptical with a diameter ranging from 100 to 180 nm and have a dense core with areas of minor density.

The head cartilage of cephalopods. I. Architecture and ultrastructure of the extracellular matrix.

The morphology of head cartilage of the cephalopods Sepia officinalis and Octopus vulgaris has been studied on samples fixed and embedded for light- and electron microscopy and on fresh frozen sections viewed by polarizing microscopy. The organization of extracellular matrix (ECM) varies in different regions of the head cartilage. Superficial zones are made up of densely packed collagenous laminae parallel to the cartilage surface, while radially arranged laminae form a deeper zone where territorial and interterritorial areas are present.

Testicular biopsy of azoospermic men with vas deferens malformation using two different techniques.

A morphological analysis was carried out on testicular biopsies of men with obstructive azoospermia as consequence of vas deferens malformations as compared with biopsies from fertile men. For each case the biopsies were processed with two different techniques: routine histological procedure, and semithin sections of specimens processed for electron microscopy. Four parameters were considered: tubular morphology, testicular biopsy score count (TBSC), tubular diameter, and germinal cell density.

Ultrastructural study of the dermis in a case of type IV Ehlers-Danlos syndrome.

Light microscopic and ultrastructural examination of the skin in a case of type IV Ehlers-Danlos syndrome (EDS) showed the presence of morphological changes involving all the dermis components. Collagen fibres were smaller, more irregular and more spaced apart than in normal dermis. Conversely, elastic, microfibrillar and amorphous components were considerably increased.

The morphology of seminiferous tubules of human testicular biopsies. Analysis of the data obtained with two different techniques.

Testicular biopsies of fertile men and of azoospermic patients for vas deferens agenesis were processed with two different techniques, i.e. routine histological procedure and semithin sections of electron microscopy preparations.

The ultrastructure of the byssal apparatus of a mussel. V. Localization of collagenic and elastic components in the threads.

Ultrastructural and cytochemical studies have been carried out on the proximal part of byssus threads (TPP) in an attempt to localize collagenic and elastic components. The results show that TPP autoclaving followed by hot alkali treatment causes the extraction of about two-thirds of hydroxyproline and the parallel removal of most of the matrix, leaving filaments unaffected. Moreover the results of the staining reactions signaletic for elastic tissues indicate that TPP filaments contain glycoproteins with a reactivity similar to that of many invertebrate elastic tissues.