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Biomedical subjects

G Gherardi

Publications and source records attributed to G Gherardi.

9 recordsLinked to original sources
PubMed1992

Primary oat cell (neuroendocrine) carcinoma of the breast. Report of four cases.

Four cases of oat cell (neuroendocrine) carcinoma of the breast are reported. Three patients died within 15 months of the diagnosis and the fourth patient is alive after 44 months. Histochemical, ultrastructural and mRNA markers of endocrine differentiation were present in three cases. These tumours show histological similarities to breast metastases of bronchial oat cell carcinoma, but a distinguishing feature is the presence of in situ ductal lesions. It appears that the breast is a further site which has to be added to the long list of extrapulmonary oat cell carcinomas.

Adult↗
PubMed1991

Collagen type III glomerulopathy: a new idiopathic glomerular disease.

A new type of idiopathic glomerular disease is reported in a 49-year-old Italian woman who presented with uncharacteristic renal symptoms, i.e., hypertension and slight proteinuria. Clinical investigation excluded a familial renal disease and more specifically nail-patella syndrome. Diagnostic renal biopsy by light microscopy showed a picture similar to membranoproliferative glomerulonephritis. The enlarged glomeruli were lobulated, the peripheral basement membranes were thickened by the deposition of light-microscopically undefined material, cell proliferation was lacking. By electron microscopy, the material was nonhomogenous, partly granular partly fibrillar, containing typical collagen fibers. The latter were identified as collagen type III, to a lesser extent collagen type I. Review of the literature resulted in 12 similar or identical cases reported from Japan and one additional case reported in a white American female. Evidence of systemic disease is lacking. Etiology and pathogenesis are elusive. A progressive deterioration of renal function must be expected. Collagen type III glomerulopathy is suggested as term of this new type of idiopathic glomerular disease.

Biopsy↗
PubMed1977

Osteocyte ultrastructure in renal osteodystrophy.

The ultrastructure of the osteocyte has been studied in 80 needle biopsies from the iliac crest of uremic subjects with renal osteodystrophy. Different types of osteocytes were present in the osseous trabeculae. Those recognizable in completely uncalcified osteoid tissue looked like normal osteocytes, even though the matrix was not mineralized. Those present in hypomineralized areas showed enlarged and irregular lacunae when examined under the light microscope; under the electron microscope these osteolytic-like changes were not evident and were found to have been produced by defective calcification of the perilacunar matrix. Osteocytes placed in matrix whose mineralization was normal were often surrounded by a border of crystals protruding side-to-side from the bone matrix into the lacunar space. Other osteocytes were placed in unusually wide lacunae. They showed evidence of osteolytic activity, chiefly consisting of irregularity of the lacunar wall, presence of flocculent, granular and filamentous material in the pericellular space, and calcification of mitochondria. Degenerating and degenerate osteocytes were also recognizable.

Adolescent↗
PubMed1976

Bone changes in hemodialyzed uremic subjects. Comparative light and electron microscope investigations.

Needle biopsies from the iliac crest of 40 uremic patients treated with hemodialysis have been compared by light and electron microscopy. The most obvious bone changes were represented by an increased amount of osteoid tissue (osteomalacic changes) and by enhanced bone resorption. The osteomalacic changes were chiefly characterized by the presence of thick osteoid borders whose collagen fibrils were often completely uncalcified. In a few cases, small roundish aggregates of crystals were irregularly present through the osteoid matrix; some of them were closely related to roundish, electron-dense bodies surrounded by a membrane. The increased rate of bone resorption, which was often comparable to that which occurs in the most severe cases of primary hyperparathyroidism, was due to both osteoclastic activity and osteocytic osteolysis. Electron microscopy showed that the enlargement and irregularity of the osteocytic lacunae were not always due to osteocytic osteolysis; the same effect might be due to defective calcification of the lacunar wall. The advantages of comparing the same specimens under the light and electron microscopes are discussed.

Bone Resorption↗
PubMed1975

Histochemical and electron microscopy investigations on medullary bone.

Folliculin administration to pigeons stimulates the development of medullary bone in marrow spaces of the femora and other long bones. It is a specialized osseus tissue not devoted to mechanical functions and which is rapidly reabsorbed before egg-shell formation. Medullary bone is formed and reabsorbed in the same way as other types of bone. Consequently, because of its very rapid rate of formation and resorption, it represents an ideal tissue for studying osteoblastic, osteoclastic and osteocytic activity, and the calcification process. Medullary bone is deeply stained by PAS, Alcian blue and colloidal iron and is metachromatic after toluidine blue staining. This shows that its interfibrially ground substance contains relatively high amounts of glycoproteins and acid proteoglycans. Calcification initially occurs in maxtrix vesicles (or calcifying globules) which are very numerous between the collagen fibrils of the osteoid tissue, and successively spreads into the surrounding interfibrillar matrix. Here, the crystals are closely related to thin, filament-like organic structures which seem to be components of ground substance proteoglycans. These findings confirm that in medullary bone, as in other types of calcifying tissue, the inorganic substances is initially laid down within calcifying globules and is successively closely related to organic, non-collagenous, filamentous organic structures (crystal ghosts) which probably represent a framework for calcium salt deposition.

Animals↗
PubMed1975

[Functional block in the His-Purkinje system (author's transl)].

In nine patients without clinical or laboratory evidence of heart disease, premature atrial depolarization (PAB) induced a complete block of conduction in the intraventricular conducting system. In these patients the functional refractory period AV (FRPav)) gave short and very similar results to the effective refractory period of the His-Purkinje system (ERPhp), and the effective refractory period AV (ERPAV) was found to be shorter than the ERPhp in all cases. A linear correlation between the ERPhp and the basic cycle length (BCL) was also observed. These special functional properties of the AV node justify the occurrence of intraventricular block after PAB. In fact, the stimulus, rapidly conducted through the AV node, finds a complete or incomplete refractoriness in the ventricular conducting system, and therefore bundle branch or complete intraventricular block occurs. The linear correlation between the ERPHP and the BCL explains why the atrial pacing is not always useful for pointing out intraventricular conducting defects.

Adult↗
PubMedDate not supplied

Immunocytochemistry in head and neck aspirates. Diagnostic application on direct smears in 16 problematic cases.

This report describes our experience with immunocytochemical staining of routinely processed smears in the fine needle aspiration (FNA) biopsy diagnosis of 16 tumors of the head and neck. Immunocytochemistry (ICC) was performed on alcohol-fixed or air-dried smears using commercially available monoclonal antibodies followed by a streptavidin-biotinylated peroxidase labeling method. In 12 aspirates with cytologically unclassifiable and undifferentiated cells, immunostaining for cytokeratin, leukocyte common antigen, S-100 protein and vimentin provided conclusive evidence of cell lineage. ICC permitted the correct identification and differential diagnosis of four additional tumors: a positive immunoreaction for thyroglobulin identified a metastatic Hürthle cell carcinoma of the thyroid; a coexpression of two distinct classes of intermediate filaments helped support the FNA diagnoses of a parathyroid adenoma and of a synovial sarcoma; and the double immunoreaction for CD15 and CD30 antigens helped identify Reed-Sternberg cells within an unusually suppurative harvest. Two immunostains were required for proper diagnosis in 13 cases and four in the remaining 3. In all cases but one only unstained slides were used. These data demonstrate that immunostaining can conveniently and advantageously be performed on direct smears of aspirated samples of head and neck lesions, but cases should be carefully selected for this procedure.

Adolescent↗
PubMedDate not supplied

Parotid metastasis of Merkel cell carcinoma in a young patient with ectodermal dysplasia. Diagnosis by fine needle aspiration cytology and immunocytochemistry.

Fine needle aspiration (FNA) biopsy was performed on an intraparotid lymph node metastasis of a Merkel cell carcinoma of the eyelid in a 15-year-old girl with antecedent ectodermal dysplasia syndrome. The cytologic appearance of the aspirate and the results of immunocytochemical typing of intermediate filaments on the FNA smears provided a definitive diagnosis. The Romanowsky stain provided an excellent delineation of paranuclear intracytoplasmic "buttons," which appeared to contain both cytokeratin and neurofilaments by immunocytochemical studies. These findings confirm previous data emphasizing the role of light microscopic observations, supplemented by proper immunocytochemical investigations, in the differential diagnosis of metastatic Merkel cell carcinoma in fine needle aspirates.

Adolescent↗