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M Bellocci

Publications and source records attributed to M Bellocci.

36 records · Page 2Linked to original sources
PubMed1982

[Arrest of maturation in spermatogenesis].

The ultrastructural aspects of the germinal epithelium of 10 infertile men affected by maturative arrest of spermatogenesis were studied. We noted an increased number of malformed germinal cells. Marginal nuclear vescicles were present in spermatogonia of patients affected by spermatogonial arrest. The few spermatid present in the germinal epithelium of the patients affected by a spermatidic arrest presented changes of the nuclear condensation, the acrosome, and the tail. The Sertoli cells presented an immature aspect of the nucleus and changes of the "mantle". A possible correlation between the Sertoli cells changes and the altered spermatogenesis was proposed.

Humans↗
PubMed1982

Effects of chymopapain on intervertebral disc and cartilage. (Ultrastructural study).

A direct ultrastructural study was carried out with a view to determining the changes brought about in vitro by chymopapain on the intervertebral disc and the vertebral growth plate. The tissues studied were: (A) fragments of protruded nucleus pulposus and extruded disc tissue; (B) portions of human and rabbit annulus fibrous; (C) fragments of rabbit vertebral growth plate. The fragments of tissue were incubated with chymopapain for three, six and twenty-four hours and were then fixed. In the protruded nucleus pulposus and extruded disc tissue, chymopapain produced disappearance of the electron-dense granules (which are presumably proteoglycans) and of the electron-dense granular material of the intercellular matrix. The enzyme probably also has an injurious action on the chondrocytes, but does not affect the fibrils and collagen fibres. Its action is also conditioned by the dimensions of the fragment of tissue incubated. If this is large, only the peripheral portion is completely digested. The action of the enzyme on the annulus fibrosus and the vertebral growth plate is similar to that on the nucleus pulposus. The present study indicates that the clinical effects of chymopapain are due to digestion of the proteoglycan granules and the electron-dense granular material of the herniated nucleus pulposus. These effects appear to be correlated with the collagen fibre content of the tissue, in the sense that the greater the collagen content, the more tissue mass remains unaffected.

Adult↗
PubMed1979

Morphological, histochemical and biochemical studies on germ cell mitochondria of normal rats.

Morphological changes in rat germ cell mitochondria are described. In diplotene and secondary spermatocytes and in the spermatids of the Golgi, cap and acrosomal phases, the mitochondria take on a rounded appearance with the inner space containing the matrix flattened against the outer membrane and the intracristal spaces considerably swollen ("condensed" mitochondria). Functional studies on "condensed" mitochondria isolated from the germ cells of normal rats have been performed. The following parameters have been evaluated: ADP/O ratio, respiratory control ratio (RCR) and ADP affinity. The ADP/O values found in the presence of various substrates are in agreement with the theoretical figures. The RCR is remarkably high. Moreover, the ADP affinity of these mitochondria is very high, as demonstrated by the low values of the "apparent Km". These biochemical findings, which demonstrate a high oxidative capacity coupled with a marked phosphorylation, suggest that the "condensed" appearance of germ cell mitochondria is the expression of an active functional state.

Adenosine Diphosphate↗
PubMed1978

Behavior of a cell line derived from a mouse submaxillary adenocarcinoma during the initial 480 days in vitro.

A cell line was established from a transplantable adenocarcinoma, containing viral particles of the A and B type, drived from a tumor appearing spontaneously in the submaxillary region of a male mouse of the C3H/He strain. This line, after 480 days in vitro, did not change the original epithelial-like morphology, the viral expression, the membrane immunofluorescence and the degree of agglutination by various plant lectins. After 208 days of culture, the presence of up to 3 pairs of metacentric chromosomes appeared in about 55% of the cells. However, this change in the chromosomal pattern was not sufficient, at least within the limits of our observation, to modify significantly the other parameters investigated, with the possible exception of the oncogenicity, which showed a modest decrease after 296 days of culture.

Adenocarcinoma↗
PubMed1978

Role of hyaluronic acid in the in vivo aggregation of cartilage proteoglycans.

From studies of isolated cartilage proteoglycans in solution it has been inferred that they occur in the tissue as aggregates of high molecular weight which consist of proteoglycan monomers, hyaluronic acid and specific link proteins. The present investigation provides direct evidence for the existence of hyaluronic acid-containing aggregates in vivo, as indicated by the following observations: Treatment of sections of coastal cartilage from newborn rabbits with Streptomyces hyaluronidase led to complete disappearance of the electron dense granules, which have been previously identified as chondroitin sulfate proteglycans, from the extracellular matrix. Similar results were obtained on digestion with leech hyaluronidase which, like the Streptomyces enzyme, specifically degrades hyaluronic acid. Proteoglycan aggregation occurs not only in the extracellular compartment but intracellularly as well, since a portion of the hyaluronidase-senstive, electron dense proteoglycan granules are found in intracellular vesicles. It is concluded that the ability of proteoglycan monomers to form aggregates is a true reflection of the in vivo organization of these molecules and that aggregate formation is an important factor in the maintenance of the normal physiological function of cartilage tissue.

Animals↗
PubMed1977

Sertoli cells of adult rats "in vitro". A morphologic and functional study.

A cell line obtained from isolated seminiferous tubules of adult rat testis has been studied "in vitro" over a period of 35 days. Light and electron microscopic studies performed from hour 2 to the end of culture have shown the presence of a monomorphic cell population. After 5-6 days of culture the cells formed a monolayer. The cytoplasm of the cells contained numerous lipid bodies and produced numerous projections. The nucleus showed several indentations and one or more nucleoli. From the 9th to the 15th day of culture the cells developed a large amount of endoplasmic reticulum, Golgi apparatus and aggregates of electron dense granules. From the 20th to 40th day the cell cultures progressively degenerated. Immunochemical analysis of the culture medium revealed the presence of estradiol-17beta, which reached its maximum production rate from the 8th day to the 18th day of culture. Corresponding to cell involution estradiol concentration underwent a rapid decrease. On the basis of morphological and biochemical data the cells could be considered Sertoli cells.

Animals↗
PubMedDate not supplied

An ultrastructural study of recurrent disc herniation: a preliminary report.

One early and two late recurrent herniations located at the same interspace as the original prolapse were studied by light and electron microscopy. In the early recurrent herniation, most chondrocytes appeared to be actively engaged in protein synthesis, and the intercellular matrix contained densely packed collagen fibers, numerous matrix vesicles, and abundant electron-dense amorphous material. In late recurrent herniations, chondrocytes had scant endoplasmic reticulum and extensive cytoplasmic filaments, and the intercellular matrix showed intermediate features between fibrocartilage and fibrous connective tissue. On the basis of these morphologic characteristics, it seems reasonable to assume that the newly formed disc tissue arose mainly from remnants of the original herniation in the early recurrent prolapse and from the annulus fibrous and the granulation tissue invading the disc space after discectomy in the late recurrent herniations.

Adult↗
PubMedDate not supplied

Juvenile kyphosis: an ultrastructural study.

Biopsy specimens of the spine, including intervertebral disc, vertebral plate, growth plate, and part of the vertebral body, were obtained from seven patients with juvenile kyphosis treated by anterior spinal arthrodesis. Histological and histochemical studies showed abnormal loose-appearing cartilage in both the vertebral plate and the growth plate. Both plates were missing in some vertebrae. Ultrastructurally the abnormal cartilage had a matrix rich in proteoglycans and very thin collagen fibrils. The mineralization and ossification of the vertebral plates were irregular. Vertebral bone growth was stunted under the areas of abnormal growth plates.

Adolescent↗
PubMedDate not supplied

Relationship between theoretical molecular weight and blister fluid/serum ratio of cytokines and five other molecules evaluated in patients with bullous pemphigoid.

Bullous pemphigoid (BP) blisters contain several molecules, some of which spread into the blisters from the interstitial fluid, while others are produced locally and migrate into the circulation. The calculation of the ratios between blister/serum concentrations may help to distinguish between these two types of molecules. The rules regulating the diffusion of the molecules have been described only in suction blisters, where the theoretical molecular weight (MW) represents one of the principal influencing factors. The aim of the present study was to analyse the relationship between theoretical MWs and the ratios of concentrations of several molecules evaluated both in sera and in blister fluids. Eight cytokines (interleukin-2, interleukin-3, interleukin-4, interleukin-5, interleukin-10, tumor necrosis factor-alpha, oncostatin-M and vascular endothelial growth factor), two acute phase reactants (alpha-1 acid glycoprotein, haptoglobin), albumin, one soluble membrane molecule with adhesion functions (sICAM-1) and the eosinophil cathionic protein (ECP) were measured in samples from 15 patients affected with BP by means of commercially available tests. The data suggest that the MW may influence the rate of diffusion throughout the blister, both in input and output directions, despite the discontinuity observed at the basement membrane level on the BP blister floor.

Acute-Phase Proteins↗