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Biomedical subjects

M A Greco

Publications and source records attributed to M A Greco.

143 records · Page 8Linked to original sources
PubMedDate not supplied

Gastrin-releasing peptide in hypoplastic lungs.

The relative abundance of pulmonary neuroendocrine cells synthesizing gastrin-releasing peptide (GRP) was estimated for normal fetal lungs and hypoplastic lungs. Percentage of bronchiolar epithelial area staining positively with anti-GRP antiserum was computed for each case using a SAMBA 4000 image analyzer. The majority of hypoplastic lungs (10 of 12 cases) showed markedly diminished GRP immunoreactivity, which appeared to vary with etiology. Six cases of pulmonary hypoplasia associated with renal anomalies, three cases associated with hydrops, and one case of diaphragmatic hernia showed an average fivefold reduction in percentage of GRP immunostaining. A case of hypoplasia associated with Werdnig-Hoffmann disease had GRP immunoreactivity similar to that of controls, and GRP expression was markedly elevated (fivefold) in a case of hypoplasia with omphalocele.

Antibodies, Monoclonal↗
PubMedDate not supplied

Ewing's sarcoma with epithelial differentiation: fine structural and immunocytochemical study.

A femoral Ewing's sarcoma from a 13 1/2-year-old girl with otherwise typical clinical and pathological features showed epithelial differentiation by electron microscopy and immunocytochemistry. The expression of keratin and the presence of tonofilaments in cells of this Ewing's sarcoma may enforce the hypothesis that Ewing's sarcoma derives from a multipotential primitive stem cell.

Adolescent↗
PubMedDate not supplied

Immunohistochemical and electron microscopic profiles of cutaneous Kaposi's sarcoma and bacillary angiomatosis.

Thirty cases of cutaneous Kaposi's sarcoma (KS) were evaluated and compared with eight cases of acquired immunodeficiency syndrome (AIDS)-related bacillary angiomatosis (BA). The morphologic features of both lesions were studied by light and electron microscopy and by immunohistochemistry with monoclonal endothelial antibodies against CD34, BNH9, and factor VIII-related antigen as well as the lectins Ulex europaeus 1 and Psophocarpus tetragonolobus. Macrophage/monocyte markers used were alpha 1-antitrypsin, lysosome, Kp1 (CD68), and polyclonal factor XIIIa. Electron microscopic studies demonstrated that most of the spindle cells in KS showed a paucity of cell organelles and an absence of Weibel-Palade bodies (WPB), whereas the cells in BA showed activated endothelial cells with WPB. By immunohistochemistry the spindle cells in KS were consistently positive for CD34 only, whereas proliferating cells in BA expressed all endothelial markers used. Numerous cells expressing macrophage/monocyte markers were present surrounding both KS and BA, and a small number of similar cells were entrapped within both lesions. The results demonstrated a restricted immunohistochemical profile for endothelial cell markers in spindle cells of KS (CD34+) distinct from that of endothelial cells in BA. These findings suggest that the spindle cells in KS are poorly differentiated endothelial cells or that they belong to an endothelial cell subset with partial expression of endothelial phenotype.

Angiomatosis, Bacillary↗
PubMedDate not supplied

Angiogenic process in bacillary angiomatosis.

Eight cases of cutaneous bacillary angiomatosis related to acquired immunodeficiency syndrome were studied by light and electron microscopy and by immunohistochemistry with a panel of antibodies specific for endothelial and histiocytic markers. Light microscopy showed an inflammatory reaction with florid neovascularization and clusters of Warthin-Starry-positive bacilli. In addition, solid areas of spindle cells were also present that in some cases mimicked Kaposi's sarcoma or other sarcomas. The investigation focused primarily on the spindle cell areas and the angiogenic process present in bacillary angiomatosis. By immunohistochemistry the lesions, including the spindle cell areas, expressed all endothelial markers used; CD34, factor VIII-related antigen, and Ulex europaeus 1 were the most consistent in intensity, however. In those areas the other endothelial markers, BNH9 and Psophocarpus tetragonolobus, were weak and not always uniform. The macrophage/monocyte markers used were alpha 1-antitrypsin, lysosome, kp1 (CD68), and polyclonal factor XIIIa; these revealed a sprinkle of positive cells ranging from 10% to 20% of the cell population. By electron microscopy primitive capillaries were present lined by plump endothelial cells containing frequent abluminal microprocesses forming intercellular lumina. Mitoses and intracytoplasmic lumen formation were infrequent. The study illustrates that bacillary angiomatosis is composed of active endothelial neoformation with the spindle cells representing immature endothelial cells. Furthermore, the features of this angiogenic process recapitulate the morphologic events described in experimental models.

Angiomatosis, Bacillary↗
PubMedDate not supplied

Tenascin-C expression in ultrastructurally defined angiogenic and vasculogenic lesions.

Tenascin-C (TN) is an extracellular matrix glycoprotein expressed during embryogenesis. Its distribution is restricted in normal adult tissues and is upregulated in tumors and inflammatory conditions. Twenty-five specimens were studied, including 7 reactive vascular lesions (6 cases of granulation tissue and 1 case of bacillary angiomatosis), and 18 vascular tumors (6 angiosarcomas, 7 hemangioendotheliomas, and 5 AIDS-related nodular type Kaposi's sarcomas). Formalin fixed-paraffin-embedded tissues were stained with monoclonal antibody to TN (DAKO) and with MIB-1 (AMAC). Heterogeneous expression of TN immunoreactivity was seen in all cases, with a diffuse pattern in bacillary angiomatosis and most granulation tissue cases and a focal pattern in angiosarcoma and most hemangioendothelioma cases. Kaposi's sarcoma cases showed both a focal and diffuse pattern of distribution. In most cases proliferation indices (PI) did not correlate with TN expression. Electron microscopy demonstrated active angiogenesis in bacillary angiomatosis and granulation tissue and vasculogenesis in angiosarcoma and hemangioendothelioma. The study demonstrated positive TN expression in reactive lesions with angiogenesis (granulation tissue and bacillary angiomatosis) and neoplastic lesions showing vasculogenesis (angiosarcoma and hemangioendothelioma), although with a different pattern of distribution. These results suggest that TN might be an important extracellular matrix glycoprotein in angiogenesis and vasculogenesis.

Angiomatosis, Bacillary↗
PubMedDate not supplied

Successful multimodal therapy for kaposiform hemangioendothelioma complicated by Kasabach-Merritt phenomenon: case report and review of the literature.

We present the management challenge provided by a patient with kaposiform hemangioendothelioma associated with Kasabach-Merritt phenomenon. A female child presented at 14 months of age with an ecchymotic swelling of her right upper arm and axilla. Subsequently, she developed profound thrombocytopenia and hypofibrinogenemia (Kasabach-Merritt phenomenon). Biopsy of the lesion revealed kaposiform hemangioendothelioma, which has been reported as the predominant pathologic diagnosis associated with Kasabach-Merritt phenomenon. To achieve involution of the lesion and preserve function of the arm, the following interventions were involved: embolization, systemic interferon, cyclophosphamide, epsilon aminocaproic acid, and compression therapy. The clinical management of this patient was formidable until we arrived at the proper combination of therapies. Multimodal intervention may be required to manage fastidious hemangioendotheliomas of childhood, achieve clinical improvement, and prevent further morbidity.

Female↗
PubMedDate not supplied

Mucosal neuromas and plexiform neurofibromas: an immunocytochemical study.

Mucosal neuromas (MN), a component of multiple endocrine neoplasia (MEN) type IIb, may be confused histologically with plexiform neurofibromas (PN), a component of neurofibromatosis. The ability to distinguish between these two markers for different genetic diseases is crucial, as the risk of development of medullary thyroid carcinoma and pheochromocytoma in affected patients with MEN IIb is great. We studied two cases each of MN and PN by immunocytochemistry (IC). Epithelial membrane antigen (EMA) proved to be the most useful marker. MN consisted of bundles of disorganized and tortuous nerve fibers surrounded by a thickened perineurium that expressed the cellular phenotype EMA(+), S-100(-). PN consisted of enlarged nerve fascicles with a loose myxoid stroma and was EMA negative. Thus, IC highlighted the differing pattern of growth and histogenesis of the proliferating cells in the two lesions and is likely to be especially useful in those lesions with atypical histology.

Adult↗
PubMedDate not supplied

[Research on the biological risk in the hospital environment].

The epidemiological monitoring of injuries due to exposure to potentially infected biological liquids constitutes the indispensable premise for the elaboration of strategies meant to intervene to reduce the incidence. This work shows the results of an epidemiological study relative to the period going from January 1, 1994--December 31, 1998 elaborated by the use of the register of injuries deposited with the Sanitary Direction. The variables shown here allowed us to individualize the prevalence of injuries in the various professional categories, the working zones, the type and form of injury, the use of individual protection devices. The analyses of the data has shown a scarce sense of risk by the sanitary workers and a scarce application of protective measures. It's evident of the need to intervene in the formation of the workers to sensibilize then to the importance of preventive measures.

Biological Assay↗
PubMedDate not supplied

Cytologic findings in progressive multifocal leukoencephalopathy. Report of two cases.

Cytologic preparations from two cases of progressive multifocal leukoencephalopathy (PML) were obtained by stereotactically guided needle biopsies using computerized tomograms of the brain. Case 1 was a 32-year-old man with an acquired immunodeficiency syndrome-related complex. Case 2 was a 71-year-old man with chronic lymphocytic leukemia. Smears showed moderate cellularity, consisting of moderately to markedly atypical cells with enlarged hyperchromatic nuclei. The chromatin pattern showed smudging, with or without clumping, similar in pattern to the human polyomavirus-infected "decoy" cells seen in urine cytology. Nuclei were predominantly round to oval, smoothly contoured and often stripped of cytoplasm. Occasional bizarre lobulated or multinucleated forms were seen. Some atypical cells had abundant cytoplasm exhibiting stellate projections. Histologic sections of the biopsy material confirmed the diagnosis in each case. In both cases, electron microscopy demonstrated intranuclear polyoma-type virus particles. The present findings suggest that PML should be considered in the differential diagnosis of marked cytologic atypia in brain aspirates from immunocompromised patients.

AIDS-Related Complex↗
PubMedDate not supplied

Hepatoblastoma. Report of a case with cytologic, histologic and ultrastructural findings.

Hepatoblastoma, although rare, is the most common primary malignant neoplasm of the liver in children. In this paper we describe a case of hepatoblastoma with unusual cytologic features and present the histologic, immunocytochemical and ultrastructural features of this neoplasm. A 7-month-old girl presented with a large hepatic mass and metastatic nodules in both lungs. Intraoperative biopsy revealed a hepatoblastoma. Aspiration biopsy yielded a highly cellular aspirate with cords of pleomorphic cells embedded in a mucoid matrix. Histologic sections showed a diffusely infiltrative neoplasm composed of sheets and cords of highly pleomorphic cells. The neoplastic cells stained strongly positive for cytokeratin CAM 5.2 and AE1 and focally positive for alpha-fetoprotein, ferritin, carcinoembryonic antigen and vimentin. Ultrastructurally, the neoplastic cells had abundant intercellular junctions and intracytoplasmic aggregates of intermediate filaments. A mucoid matrix, to our knowledge, has not been reported as a finding on aspiration biopsy. This patient presented with pulmonary metastases, and thus we think the mucoid matrix may be a marker of a more aggressive variant of hepatoblastoma. This case illustrates additional cytologic features of hepatoblastoma and the usefulness of aspiration biopsy in the rapid diagnosis of this rare tumor.

Antineoplastic Combined Chemotherapy Protocols↗
PubMedDate not supplied

Growth fraction determination in pulmonary hypoplasia using Ki-67 (MIB-1) antibody.

Pulmonary hypoplasia (PH) is a developmental abnormality that is typically assessed using lung/body weight ratios, radial alveolar counts, or lung volume measurements. Although it is often assumed that PH results from failure of growth and development, analysis of the proliferative index in PH has not been extensively described. We examined the lungs of 12 fetuses and newborn infants with pulmonary hypoplasia and those of 8 gestational age-matched controls using Ki-67 immunohistochemistry. Formalin-fixed, paraffin-embedded tissues were utilized. Growth fractions (GFs) were determined for peripheral lung parenchyma and bronchioles. The ratio of GFs for parenchyma and bronchioles was compared. There was no significant difference in the GF ratios obtained between control and hypoplastic lungs when gestational age was < 24 weeks. However, for gestational age > 24 weeks the GF ratio of mean values for controls was approximately four times the ratio of the mean values for the hypoplastic lungs. GF did not vary according to the presumed cause of PH, and at gestational ages < 24 weeks rates were the same as or greater than those of controls. These findings suggest that proliferative potential exists at < 24 weeks and that the growth of the lung parenchyma in relation to the conducting airways is significantly reduced or ceases after this point in gestation. Clinical interventions at or before 24 weeks of gestation might result in improved survival of infants with a propensity for pulmonary hypoplasia.

Abortion, Spontaneous↗
PubMedDate not supplied

Proliferative activity of adrenal glands with adrenocortical cytomegaly measured by MIB-1 labeling index.

To investigate the proliferative activity of cytomegalic cells in the fetal adrenal cortex, we studied adrenal glands with cytomegaly by immunohistochemistry using the nuclear proliferation maker MIB-1. The percentage of positively stained nuclei was quantified using the SAMBA 4000 image analysis system. Only one case showed occasional positively stained cytomegalic cell nuclei. The permanent cortices showed proliferative activity that decreased with increasing gestational age. No proliferative activity was seen in normal fetal cortices except in one case that received corticosteroid therapy and had a maternal history of diabetes. The near absence of proliferative activity of the cytomegalic cells supports the previously proposed theory of cellular exhaustion following hyperactivity. The high proliferative activity in the fetal cortex of the infant receiving corticosteroid therapy may provide insight into the stimulus causing the hypermetabolic state.

Abortion, Spontaneous↗
PubMedDate not supplied

Opportunistic infections in pediatric HIV infection: a study of 74 autopsy cases from Latin America. The Latin American AIDS Pathology Study Group.

The present report describes opportunistic infections found at 74 autopsies of pediatric HIV/AIDS patients performed at several hospitals in Latin American countries. Fungal infections were the most common (53 cases), Candida sp. (39.18%) and Pneumocystis carinii (20.27%) being the most frequently recognized. Other fungal diseases included histoplasmosis, aspergillosis, and cryptococcosis. Viral infections were present in 31 cases, 38.7% being due to cytomegalovirus. Other viruses recognized included herpes simplex and adenovirus. Additional opportunistic infections were due to Mycobacterium avium-intracellulare, toxoplasmosis, and tuberculosis. Nonspecific bacterial bronchopneumonia was present in 11 cases. Cytomegalovirus and P. carinii coinfection was the most common association found. In this series patients died at a younger age (72% at or younger than 1 year old) and there was a slightly higher number of cases of histoplasmosis and brain toxoplasmosis than in other previously published series of infants and children.

AIDS-Related Opportunistic Infections↗
PubMedDate not supplied

Disseminated calcification with predominant muscle and cerebral involvement in a child with acquired immunodeficiency syndrome: a case report.

Calcification, as a feature of the vasculopathy, is a common pathological finding in children with acquired immunodeficiency syndrome. Large and small blood vessels of many organs including brain, heart, lungs, kidneys, liver, and spleen are affected. We report a case with calcification in multiple organs that was most prominent in the cardiac and skeletal muscle cells and the blood vessels of the cerebrum. To our knowledge, calcification of this degree has not been documented previously in a human immunodeficiency virus-infected child.

Acquired Immunodeficiency Syndrome↗