PubMed Health⌕ Search

Biomedical subjects

G Zummo

Publications and source records attributed to G Zummo.

At least 37 records · Page 2Linked to original sources
PubMed1984

[Ultrastructural observations on the presence of stereocilia in myoblasts of Scyllium stellare].

Many Authors described primary 9+0 cilia in different tissue of different animal species. In relation to the study on the ultrastructural architecture of the embryonic heart of a elasmobranch "Scyllium stellare", we saw some primary 9+0 cilia in very undifferentiated heart tissue. The hearts dissected from the Scyllium stellare embryo at 6 months of gestation, were processed for the observations at the transmission electron microscope. The cilia are found in deep invagination of the plasma membrane, near the Golgi complex and in the perinuclear region. Various functions have been postulated for the primary 9+0 cilia.

Animals↗
PubMed1983

[Ultrastructural observations on B cells in the human synovial membrane].

Two cellular type, A and B cells, are evident in the intimal layer of the human synovial membrane. The Authors studied the B-cells that show in their cytoplasm some secretory granules that are still unknown. In the normal synovial membrane of human knee, with transmission electron microscopic techniques, the relationship between the B-cells and the blood capillary vessels and some morphological features of the secretory granules, are studied. The blood capillary vessels have a continuous cellular wall, surrounded by a basal membrane. Typical features of the B-cells are the marked development of the rough endoplasmic reticulum, the Golgi apparatus and dense secretory vesicles. The B-cells appear to constitute some specific secretory cells, but its function has yet to be determined.

Cytoplasmic Granules↗
PubMed1983

Comparative study of the arterial and lacunary systems of the ventricular myocardium of elasmobranch and teleost fishes.

The typical fish heart has a spongy trabeculated ventricular myocardium (spongiosa) supplied by the venous blood of the intertrabecular spaces (lacunae); hence it is called a "venous heart." However, in some fishes a more complex ventricular muscle is found (mixed type), in which the spongiosa is covered by an outer layer of densely arranged myocardial bundles (compacta). The compacta receives oxygenated blood from the coronary vessels. The objective of this study was to investigate relations between myoarchitecture and blood supply with an emphasis on the hitherto unexplored, putative vascular connections between the arterial and the lacunary circuits. Using histological methods combined with vascular cast techniques and India ink injections, it was possible to define four different types of ventricular myocardium and its microvasculature. In some of them an intramural network arises from the subepicardial arterial system supplying the compacta and also is distributed to the spongiosa. Extensive arterio-luminal vessels connect this coronary bed with the lacunary circuit of the spongiosa, so realizing the first evolutionary step of the Thebesian system. The highest development of these connections is found in some very active pelagic fishes. The functional morphology of these vascular patterns is discussed in relation to the phylogenetic and functional context of the fish heart. It appears that the concept of the piscine heart as a typical "venous" type is an oversimplified generalization, at least on morphological grounds.

Animals↗
PubMed1983

Central myelin in the shark Scyllium stellare (Elasmobranchii, Selachii).

The central myelin of the phylogenetically ancient shark Scyllium stellare (Elasmobranchii, Selachii) was examined at the electron microscope. The known different chemical compositions of the myelin in higher and lower vertebrates is not associated in the Scyllium with a lack of any basic structural myelin elements, but is probably linked to variations in the myelin compactness and periodicity. Several unusual myelin structures and irregular patterns of unknown origin have been observed. The relationship between myelin-forming cells and the most external layers of myelinated structures suggest the possibility that the cytoplasmic glial wrapping is not the only mechanism responsible for central myelination in this vertebrate.

Animals↗
PubMed1981

[Ultrastructural study of chorionic villi in maternal-fetal isoimmunity].

The Authors studied the Human normal full term placenta and in the feto-maternal Rh and ABO incompatibilities. In the Human normal full term placenta the sincitium trophoblastum coat shows the usual microvillosity and the normal cytoplasmatic organules; in the placenta of ABO isoimmunized subjects the sincitium trophoblastum coat is intensely vacuolyzated; in the placenta of Rh isoimmunized subjects the lamina sincitiale vacuolyzation is more evident in the basal side. Discussion on the morphology related to the placenta barrier function.

ABO Blood-Group System↗
PubMed1981

Preliminary observations on the heart of the haemoglobinless Antarctic fish Champsocephalus gunnari, Lönnberg.

The heart of the haemoglobinless and myoglobinless "icefish" Champsocephalus gunnari shows interesting morphometric and histological features. The relative heart weight in two animals (body weights 479.2 and 481.0) was significantly greater than in other sea-water teleosts and corresponds to values found in small mammals (with the exception of tuna). The histological features of both the ventricular myocardium and the bulbus arteriosus as well as the unique appearance of the parietal pericardium indicate important adaptations in the circulatory functions of this animal.

Animals↗
PubMed1980

Ultrastructural appearance of human synovial membrane in the reabsorption phase of acute haemarthrosis.

Using the electron transmission microscope, the writers studied the ultrastructural appearances of the synovial membrane obtained during acute haemarthrosis, with the aim of elucidating the morphological basis of he mechanism of reabsorption of the various components of the blood. It was observed that all the elements of the synovial intima showed substantial modifications of the cytoplasm and of the plasmalemma. The cytoplasm showed: (a) marked abundance of lysosomes and lysophagosomes; (b) the presence of conspicuous cavities crammed with erythrocytic fragments; (c) marked reduction of normal cytoplasmic organelles. The plasmalemma, on the surface bordering the joint cavity, showed numerous philopods and lamellipods. These modifications, which affected all the cellular elements of the intimal stratum, demonstrate that they are macrophagically differentiated.

Acute Disease↗
PubMed1980

Ultrastructural comparisons of human synovial membrane in joints exposed to varying stresses.

The writers used the electron transmission microscope to study the ultrastructure of the synovial membrane in joints or synovial areas that varied in their exposure to weight bearing or other mechanical stresses. They used fragments of synovial membrane obtained surgically from the knee and from the elbow joints. In the joints or synovial areas little exposed to weight bearing or traction, the three strata of which the synovial membrane is composed were well differentiated from the fibrous capsule. The intima contained abundant cells with a trophic function (chiefly A cells); the subintima was intensely vascularised and had numerous fat cells but few fibres; the subsynovia was predominantly fibrous. On the other hand, in joints or synovial areas notably exposed to weight bearing or traction stresses, the synovial membrane was thinner, with few cellular elements (mostly resembling fibroblasts) and few blood vessels, while the fibrillar component was particularly marked. These differences in the ultrastructure confirm Franceschini's hypothesis that the synovial fluid is produced in those areas of the synovia that are less exposed to mechanical stress.

Elbow Joint↗