PubMed Health⌕ Search

Biomedical subjects

G Cenacchi

Publications and source records attributed to G Cenacchi.

At least 73 records · Page 4Linked to original sources
PubMed1983

A post-embedding method: demonstration of fibronectin on human liver by PAP technique.

Fibronectin, one of the most relevant components of extracellular matrix, seems to mediate cell to cell and cell to substrate interactions by means of selective links with collagen fibrils and glycosaminoglycans. Post-embedding technique using PAP method has allowed us a precise localization of fibronectin on semi-thin sections and on adjacent thin sections, improving the knowledge of fibronectin-collagen relationships.

Fibronectins↗
PubMed1980

[Cardiac metabolism in angina patients before and after aorto-coronary bypass].

The haemodynamic indices proposed by Buckberg et al. have been used to evaluate total coronary flow and its distribution to the subendocardial tissue. The following conclusions were drawn from the data obtained in humans and in experimental pathology: 1) in regional ischaemia (angina, myocardial infarction), the DPTI/TTI ratio expresses the degree of subendocardial hypoperfusion with fair approximation, although it has some theoretical limitations, 2) in total myocardial ischaemia, as occurs during ECC, the index provides an accurate picture of the subendocardium and a useful idea of the real effectiveness of the means of myocardial protection.

Angina Pectoris↗
PubMedDate not supplied

Basement membrane production by hepatocytes in chronic liver disease.

The immunohistologic distribution of fibronectin, laminin, type IV collagen and whole basement membrane was evaluated in liver biopsies from patients with chronic active liver disease. Fibronectin was consistently increased in the areas of piecemeal necrosis, portal tracts and fibrous septa. Laminin was not detected in normal liver parenchyma. In contrast, laminin positive linear basement membrane structures were prevalent in portal tracts, fibrous septa and the peripheral sinusoids of cirrhotic nodules. In areas of piecemeal necrosis, the hepatocytes, single or assembled in "rosettes", were frequently underlined by linear deposits of laminin and type IV collagen. This immunoreactivity was often polarized, being confined to the stromal side of liver cells, while the parenchymal side was negative for both proteins. Electron microscopy revealed a typical basement membrane in corresponding areas. Hepatocytes normally do not produce a basement membrane, but do so following chronic injury. We suggest that the polarized basement membrane accumulation by hepatocytes is a hallmark of hepatocyte regeneration following damage.

Basement Membrane↗
PubMedDate not supplied

Mixed tumors, myoepitheliomas, and oncocytomas of the soft tissues are likely members of the same family: a clinicopathologic and ultrastructural study.

Four diagnostically unusual soft tissue tumors are presented. All lesions were of consistent size and long duration. Histologically, one lesion was analogous to mixed tumors of the usual sites (i.e., salivary glands), one lesion was totally spindled, and the two other lesions both had oncocytic appearances (epithelioid and spindle biphasic pattern in a case, purely epithelioid in the other). Immunohistochemically, the mixed tumor was positive for vimentin, cytokeratins, S-100 protein, and focally for EMA. The purely spindled tumor exhibited immunoreactivity for vimentin, actins, S-100 protein, EMA (focally), and GFAP. The oncocytic biphasic tumor was positive for mitochondrial antigen, vimentin, and actins. The purely epithelioid oncocytic neoplasm was immunoreactive only for mitochondrial antigen and vimentin. Ultrastructurally, in the epithelial-like portion of the first (mixed) tumor, peripheral arrays of contractile filaments were detected along with well-developed desmosomes. In the second (spindled) case, peripheral contractile filaments and attenuated desmosomes were also seen. In the third case, a huge number of mitochondria, some desmosomes, and actin-type microfilaments were found. In the fourth case, desmosomes and punctate subplasmalemmal densities, in addition to numerous mitochondria, were documented. In all cases an external basal lamina were present, which was discontinuous in the first three cases and almost continuous in the fourth. These tumors were respectively designated as mixed tumor, myoepithelioma of the classic type, myoepithelioma of oncocytic type with biphasic cell architecture, and true oncocytoma. So far, all tumors have followed benign clinical courses (median follow up: 12 months). Comparisons with similar tumors of other sites are drawn, and suggestions for considering all of them as members of the same myoepithelial-derived tumor family are given.

Adenoma, Oxyphilic↗
PubMedDate not supplied

Pituicytoma: ultrastructural evidence of a possible origin from folliculo-stellate cells of the adenohypophysis.

Pituicytoma is a rare neoplasm occurring in the sellar and suprasellar regions. The tumor is currently considered to arise from the pituicyte, a specialized glial cell of the posterior lobe and the stalk of the pituitary gland. The authors describe a case of pituicytoma, focusing on the ultrastructural features. The patient was a 79-year-old woman with hypopituitarism and visual disturbances. Immunohistochemically, the tumor showed strong and diffuse positivity for vimentin, and EMA and GFAP were focally detectable. Ultrastructurally, the lesion was composed of elongated cells containing in the Golgi area aggregates of intermediate filaments in a concentric pathway (fibrous body), and secretory granules. These features intermediate between a pituicytoma and a pituitary adenoma suggest that "pituicytomas" may also arise from the specialized stromal folliculo-stellate cells of the adenohypophysis, which are able to differentiate into endocrine cells.

Aged↗
PubMedDate not supplied

Mucin-secreting cellular ependymoma: a light and electron microscopy study.

Mucin accumulation in ependymomas is thought to be limited to the myxopapillary variant and represents an important diagnostic feature. Similarly, signet-ring cells in ependymomas have been shown by electron microscopy to represent microrosette instead of mucin secretion. This study describes an infratentorial ependymoma largely composed of mucinous areas and signet-ring cells. The ependymal nature of mucin-secreting cells was confirmed by ultrastructural analysis. This case widens the variable spectrum of ependymal morphology. The value of electron microscopy in differentiating central nervous system neoplasms showing mucous secretion is stressed.

Biomarkers, Tumor↗
PubMedDate not supplied

Gastrointestinal autonomic nerve tumor (plexosarcoma): report of a case with fine needle aspiration biopsy and histologic, immunocytochemical and ultrastructural study.

BACKGROUND: Gastrointestinal stromal tumors (GISTs) encompass a large group of mesenchymal neoplasms that display common cytologic spindle-shaped morphology on light microscopy. Immunocytochemical and ultrastructural studies can demonstrate several patterns of differentiation. CASE: A 70-year-old male presented with two intraabdominal small bowel masses. The cytopathologic features of a fine needle aspiration biopsy (FNAB) included plump spindle cells in densely populated aggregates or in a fasciculated pattern, without significant pleomorphism. An epithelioid component in a lobular arrangement with abundant, eosinophilic cytoplasm was also noted. The nuclei were vesicular, with a very evident, eosinophilic nucleolus and finely distributed chromatin. Groups of loosely cohesive cells with slender, dendritic-like cytoplasm were evident. Immunocytochemical study of the embedded, fine needle aspirated fragments of the neoplasm demonstrated immunoreactivity for vimentin and neuron-specific enolase. Cytokeratin immunoreactivity or muscular, vascular, neuroendocrine or nerve sheath differentiation failed to be demonstrated. The cytologic and immunocytochemical findings correlated well with the histologic features of the neoplasm. The morphologic diagnosis was confirmed by ultrastructural study. CONCLUSION: FNAB and immunocytochemistry can be valuable in making the correct diagnosis between gastrointestinal stromal tumors.

Aged↗
PubMedDate not supplied

Ultrastructural and immunohistochemical contribution to the histogenesis of human cardiac myxoma.

The ultrastructural features of 8 human cardiac myxomas were analyzed and correlated with immunohistochemical data, with the aim to clarify the characteristics of the cell lines involved in the tumor genesis. Immunohistochemical studies were performed to detect the presence and the distribution of intracytoplasmic filaments (vimentin, desmin, actin, myosin) as well as myoglobin and factor VIII-related antigen, albumin, and lysozyme. Eighty percent of myxoma cells were simultaneously positive for vimentin, desmin, and actin, whereas 30% of them stained with antifactor VIII and antivimentin antibodies. The submicroscopic analysis revealed two main cell populations: (1) one composed of stellate-shaped cells with scanty organelles and sparse hyaloplasmic filaments scattered throughout the myxoid stroma and forming a loose network with their projections; (2) another one included cells with more cytoplasmic organelles, intermediate filaments, and myofilaments arranged either singly or in both solid and hollow cord-like structures. Our results support the hypothesis that cardiac myxoma may originate from a reserve multipotent mesenchymal cell able to differentiate more or less completely along two major evolutional lines: myoid and endothelial. The tumor tissue thus seems to be involved in vessel formation, suggesting a growth pattern akin to that manifested in other forms of endocardial pathological reactivity in which reserve mesenchymal cells are engaged.

Adult↗
PubMedDate not supplied

Ultrastructural characterization of oligodendroglial-like cells in central nervous system tumors.

Cells with uniform, small-round nucleus and clear cytoplasm (oligodendroglial-like cell, OLC) are commonly observed in central nervous system (CNS) neoplasm of glial and neuronal lineage, such as oligodendroglioma, clear-cell ependymoma, and central neurocytoma. Immunohistochemistry does not always contribute to the characterization of OLC because of (1) loss of antigen expression; (2) lack of specific markers for oligodendrogliomas; and (3) occasional coexpression of neuronal and glial antigens. An ultrastructural analysis associated with an immunohistochemical study of 20 cases of CNS tumors largely constituted by OLCs has been performed. Neurocytomas (12 cases), medullocytomas (2 cases), cerebral neuroblastoma (1 case), and ganglioglioma (1 case) showed OLCs with ultrastructural features of neuronal differentiation (neuritic processes, dense-core granules, synaptic structures). Oligodendroglioma (3 cases) OLCs were characterized by mitochondrial-rich cytoplasm, and ependymoma (1 case) OLCs showed microrosettes and scattered cilia. The electron microscopic analysis can provide a more precise diagnosis of these OLC-containing tumors despite their uniform morphological appearance.

Adult↗
PubMedDate not supplied

Immunohistochemical and ultrastructural investigation of neural differentiation in Ewing sarcoma/PNET of bone and soft tissues.

The authors evaluated the role of immunohistochemistry and electron microscopy in defining neural differentiation in 28 cases of Ewing sarcoma/PNET. The panel of primary antibodies used included vimentin, MIC-2, NSE, S-100 protein, leu7, neurofilaments, GFAP, and chromogranin A. Cases were considered undifferentiated when neural markers were absent, poorly differentiated if one neural marker was present, and well differentiated if two or more markers were observed. Cases were also evaluated for the presence of cytoplasmic processes, microtubules, and neurosecretory granules as ultrastructural features of neural differentiation: the tumor was classified as well differentiated if two of these features were present; and poorly differentiated if one was evident; all other cases were considered undifferentiated. According to immunohistochemistry, 10 cases (35.7%) were undifferentiated, 12 cases (42.9%) were poorly differentiated, and 6 (21.4%) were well differentiated. According to the ultrastructural analysis, 10 tumors were undifferentiated (35.7%), 14 poorly differentiated (50%), and 4 well differentiated (14.3%). The overall concordance between the two techniques was low (35.7%), and both modalities were concordant in classifying only 1 well-differentiated, 5 poorly differentiated, and 4 undifferentiated tumors. In conclusion, the authors suggest that investigations devoted to test the prognostic significance of neural differentiation in these neoplasms should employ both immunohistochemistry and electron microscopy, separately and in combination, to assess what is the most effective choice for predicting the clinical course.

Adolescent↗
PubMedDate not supplied

The problematic issue of Kufs disease diagnosis as performed on rectal biopsies: a case report.

Kufs disease, the late-onset form of a group of neurodegenerative disorders, known as the neuronal ceroid-lipofuscinoses, is characterized by intraneuronal/extraneuronal accumulation of proteins that are visible as fingerprint inclusions and granular osmiophilic deposits (GRODs) at the ultrastructural level. A problematic case of Kufs disease in a 53-year-old female affected by progressive gait disturbances, myoclonus, epilepsy, and profound dementia is presented. Laboratory, biochemical, and molecular genetic tests were unremarkable. A magnetic resonance imaging of the brain revealed a moderate atrophy over both hemispheres with no white matter changes. Ultrastructural examination of rectal mucosa biopsies showed fingerprint inclusions in perivascular smooth muscle cells. Pathological examination of autoptic tissues showed numerous intraneuronal PAS-positive, diastase-resistant inclusions corresponding to GRODs at the ultrastructural examination, but no fingerprint inclusions. Cerebellum, skeletal, and cardiac muscles, skin, and liver were unaffected. The present case illustrates the diagnostic difficulties encountered while examining Kufs disease pathological samples. Main problematic issues include (1) specificity and diagnostic value of fingerprint inclusions when found exclusively in perivascular smooth muscle cells; (2) safe distinction of GRODs from lipofuscin inclusions in cerebral tissue; and (3) reliability in using extraneural tissues and, in particular, rectal mucosa biopsies for diagnostic purposes.

Biopsy↗
PubMedDate not supplied

Inflammatory abdominal aortic aneurysms: does an early stage exist?

Inflammatory aneurysms are characterised by a peculiar clinical (i.e. abdominal-lumbar pain, weight loss and increased ESR) and morphological picture (whitish wall, adhesion to the surrounding organs and thickness greater than 0.5 cm). The lymphomonoplasmacellular infiltrate and the interstitial deposits of collagen define the histological picture of these lesions. The authors describe three abdominal aortic aneurysms macroscopically characterised by parietal edema, hyperemia and hypertrophy of the preaortic lymphnodes. Histological study revealed a conspicuous and widespread lymphomonoplasmacellular infiltrate and interstitial edema. The abdominal-lumbar pain, the increase in ESR and the reactive C protein defined the clinical and laboratory aspects. Serological tests for syphilis, rheumatoid arthritis and lupus erythematosis were negative. The question which arises from these observations is whether these forms represent separate entities or an early stage in the evolution of inflammatory abdominal aortic aneurysms with fibrosis.

Abdominal Pain↗