Biomedical subjects

M A Greco

Publications and source records attributed to M A Greco.

At least 37 records · Page 2Linked to original sources

PubMed1997

Human parvovirus B19 in bone marrows from adults with acquired immunodeficiency syndrome: a comparative study using in situ hybridization and immunohistochemistry.

Human parvovirus B19, which infects and lyses erythroid precursors, can cause severe anemia in patients with immunodeficiency. The incidence of parvovirus infection in adult acquired immunodeficiency syndrome (AIDS) patients is unknown. Eighty-one archival formalin-fixed, paraffin-embedded (FFPE) bone marrow biopsies from 73 AIDS adults were immunostained with monoclonal R92F6 against B19 VP1 and VP2 capsid proteins using streptavidin peroxidase and streptavidin alkaline phosphatase techniques. In addition, the same tissues were hybridized in situ with a digoxigenin-labeled parvovirus B19 DNA probe. Five FFPE bone marrows, from 3 HIV-negative patients with positive immunoglobulin M (IgM) serology for parvovirus B19, and 1 parvovirus B19-infected fetal liver were positive controls. By immunoperoxidase, all tissues were negative with R92F6 except the fetal liver, which exhibited strong positivity predominantly in viral inclusions. With immunoalkaline phosphatase, all positive controls were immunoreactive with R92F6; however, the AIDS marrows were negative. With in situ hybridization (ISH), all positive controls and 7 of 81 (8.6%) of AIDS marrows were positive for B19 parvovirus DNA. We conclude that ISH is more sensitive than R92F6 immunohistochemistry in parvovirus B19 detection. A small but significant number of bone marrows from AIDS adults shows evidence of human parvovirus B19 infection.

Acquired Immunodeficiency Syndrome↗

PubMed1996

Proliferation index and vascular density of giant cell tumors of bone: are they prognostic markers?

BACKGROUND: The proliferation index (PI) and vascular density (VD) in giant cell tumors (GCT) of bone were studied to assess then value as prognostic markers. METHODS: Formalin fixed, paraffin embedded tissue from 7 nonrecurrent (NR-GCT) and 13 recurrent (R-GCT) tumors were stained with MIB-1, a monoclonal antibody against Ki-67 (nuclear proliferation antigen), and QBEND-10, a monoclonal antibody against CD34 (endothelial antigen). A minimum of ten fields/case were analyzed on the SAMBA 4000 Image Analyzer. Only mononuclear cell nuclei were analyzed for MIB-1 staining. RESULTS: Mean values +/- 1 Standard deviation (SD) for PI (stained nuclear area/total nuclear area) were: NR-GCT, 10.98 +/- 3.70; R-GCT (initial presentation), 8.94 +/- 3.57; and R-GCT (first recurrence), 9.25 +/- 3.52. In addition, the mean PI +/- 1 SD for mononuclear round-ovoid cells was 8.71 +/- 3.47 and was 9.16 +/- 10 for mononuclear spindle cells. The mean values +/- 1 SD for VD (stained area/total area of structures) were: NR-GCT, 10.61 +/- 6.37; R-GCT (initial curettage), 9.40 +/- 4.94; and R-GCT, (first recurrence), 12.56 +/- 5.88. Comparing the means for PI and VD for both groups of tumors using Student's t test showed no statistically significant differences (P = 0.34). In one case of histologically benign GCT that metastasized to the lungs, the PI of the metastatic tissue was not significantly different from the primary tumor. CONCLUSIONS: This study presents evidence that the degree of tumor cell proliferation and vascularity are not useful parameters to predict the recurrence of GCT of bone and that there are no significant differences between the PI of mononuclear round-ovoid cells and mononuclear spindle cells.

Adolescent↗

PubMed1996

Tenascin-C expression by angiogenic vessels in human astrocytomas and by human brain endothelial cells in vitro.

The expression of the extracellular matrix glycoprotein tenascin-C (TN) is enhanced in human astrocytomas and correlates with angiogenesis. To determine whether vascular cells are able to synthesize TN, we investigated the expression of TN protein and mRNA in nine astrocytomas. Immunogold electron microscopy in two glioblastomas multiforme detected the presence of TN in an extracellular perivascular location and to a lesser extent among tumor cells, confirming light microscopy immunohistochemical findings. In situ hybridization of astrocytomas using a digoxigenin-labeled antisense riboprobe detected strong staining for TN mRNA in vascular cells, especially in hyperplastic vessels, including those at the invasive edge of the tumors but not in vessels of normal brains. We observed weaker staining in tumor cells indicating a higher level of TN mRNA in vascular than in tumor cells. No staining was detected with the sense probe. Moreover, we investigated the ability of human brain microvessel endothelial cells (HBMECs) in primary culture to synthesize TN in vitro. Western blot analysis of the culture supernatants from HBMECs detected large amounts of TN. Immunogold silver staining demonstrated the presence of TN on the surface of HBMECs and in the subendothelial matrix. The distribution of TN mRNA in vascular cells of astrocytomas and the ability of HBMECs to synthesize TN in vitro demonstrate that vascular cells, including endothelial cells, are a major source of TN associated with angiogenesis. Furthermore, our results suggest that TN expression may be associated with endothelial cell activation and may play an important role in angiogenesis.

Astrocytoma↗

PubMed1996

Primary extrarenal Wilms' tumor in the inguinal canal: case report and review of the literature.

Inguinal and scrotal Wilms' tumors are extremely rare; only 15 cases have been reported to date. The authors report a case of inguinal Wilms' tumor (stage III), which occurred in a previously healthy 3 1/2-year-old boy who was staged and treated according to currently accepted National Wilms' Tumor Study III criteria. The exact embryological origin of this tumor has not been determined. However, there is evidence that the origin is more primitive than that of intrarenal Wilms' tumor.

Abdominal Neoplasms↗

PubMed1996

Expression of metalloproteinases and tissue inhibitors of metalloproteinases in giant cell tumor of bone: an immunohistochemical study with clinical correlation.

The clinical behavior of giant cell tumors (GCTs) is unpredictable. To gain insight into this tumor's biological behavior, matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) were studied. These substances play essential roles in wound healing and neoplastic invasion and metastasis. Paraffin-embedded tissue was collected from 18 cases of histologically benign GCT, with 17 treated by curettage and 1 by resection. Eight cases showed no recurrence after a minimum of 2.5 years, and 10 had local recurrence. One showed metastasis. Antibodies to MMP-9, MMP-2, TIMP-1, and TIMP-2 were applied by immunohistochemical methods. In all cases, MMP-9 was strongly expressed in giant cells predominantly in a diffuse pattern and was strong but focal in stromal cells. MMP-2 decorated stromal cells and giant cells heterogeneously. TIMP-1 was variably expressed in giant cells of the nonrecurrent cases and was strongly present in a diffuse or patchy distribution in the stromal cells in 6 of 8 cases. However, in 9 of 10 recurrent cases, TIMP-1 was expressed weakly by both giant and stromal cells. TIMP-2 was variably expressed in the giant cells of the nonrecurrent cases, but 6 of 8 nonrecurrent cases showed strong stromal cell positivity for TIMP-2. Weak staining for TIMP-2 was observed in 7 of 10 recurrent cases in the stromal cells and 9 of 10 recurrent cases in the giant cells. These results indicate that expression of MMPs and TIMPs differs in giant cells and stromal cells in the same tumor. More significantly, in contrast to the nonrecurrent giant cell tumors, there is an imbalance in the MMPs and TIMPs in the recurrent tumors with a net excess of MMPs. This unopposed expression of MMPs in GCTs may play a role in breakdown of extracellular matrix and tissue invasion. Finally, these markers may prove useful in predicting behavior in these tumors.

Adolescent↗

PubMed1995

Tenascin expression in astrocytomas correlates with angiogenesis.

We investigated the expression and distribution of the extracellular matrix protein tenascin (TN) in 59 astrocytomas and 11 samples of normal brain by Western blot analysis and immunohistochemistry using antibodies against human TN. The tumors included 14 juvenile pilocytic astrocytomas (grade 1), 13 low grade fibrillary astrocytomas (grade II), 8 anaplastic astrocytomas (grade III), and 24 glioblastomas multiforme (grade IV). Proliferation indices were calculated by computer-based image analysis after immunostaining with the MIB-1 antibody against the Ki-67 proliferation-associated antigen. Western blot analysis for TN on fresh frozen tumor tissue from 23 of the 59 astrocytomas indicated up to 4-fold higher TN expression in glioblastomas multiforme than in nontumorous control tissues. Enhanced intercellular expression of TN was observed by immunohistochemistry in glioblastomas multiforme. More-over, TN immunostaining was consistently greater within and around the walls of hyperplastic blood vessels than nonhyperplastic vessels of both high grade tumors and juvenile pilocytic astrocytomas. Juvenile pilocytic astrocytomas with increased TN expression by Western blot analysis had vascular hyperplasia by light microscopy. Proliferation indices moderately correlated with tumor grade. Enhanced immunohistochemical expression of TN was associated with higher tumor grade with higher proliferation indices. The strong association of TN and vascular hyperplasia, regardless of tumor grade, suggests that TN may play a crucial role in angiogenesis.

Astrocytoma↗

PubMed1995

Pancreatic disorders in pediatric acquired immune deficiency syndrome.

Acute pancreatitis, reported in 17% of pediatric patients with acquired immune deficiency syndrome (AIDS), is said to have a poor prognosis. We describe the pancreatic changes observed at autopsy from 71 children with human immunodeficiency virus (HIV) infection and document their nature, extent, and clinical relevance. The median age at autopsy of the children was 17 months (range, 2 months to 19 years); 38 were boys and 33 were girls. Parental intravenous drug use was the most frequent risk factor for AIDS, followed by blood transfusions. Respiratory failure and sepsis constituted the predominant causes of death. Nonspecific changes, such as edema, inflammation, fibrosis, inspissated material in acini and ducts, and enlarged Langerhans' islet predominated. Acute and chronic pancreatitis were mild except in one instance of a fatal acute probably dideoxyinosine-associated pancreatitis. Pancreatic involvement by opportunistic infections, such as cytomegalovirus (CMV), Mycobacterium avium intracellulare (MAI), and Candida, was focal and rare despite the high prevalence of these infections at autopsy. Focal lymphoplasmacytic infiltration and vascular calcifications were also observed. We conclude that pancreatic changes were frequently noted at autopsy in children with AIDS. They were usually mild, reflected systemic disease states, and were usually not life threatening. The incidence of opportunistic infections of the pancreas was low.

AIDS-Related Opportunistic Infections↗

PubMed1995

Placental transmogrification of the lung, a histologic variant of giant bullous emphysema. Clinicopathological study of three further cases.

Placental transmogrification of the lung was described by Chesney in 1978 as an unusual cystic lesion involving a single pulmonary lobe (3). We studied three additional cases with identical clinical and pathologic features. The patients were a 33-year-old woman and men aged 24 and 27 years. Each patient was first seen with respiratory distress; one had repeated pneumothoraces. Radiographically, an enlarging cystic lesion was present in a lower (two) or middle (one) lobe. The lesion had been present for 10 years in one patient. In two patients, mediastinal shift was noted. Lobectomy was curative in all instances. Grossly there was a uni- or paucilocular cyst lined by papillary structures. Microscopically, the papillae contained proliferating blood vessels, lymphoid nodules, smooth muscle, and fat. Sclerotic foci obliterated the vessels in some areas. The growth pattern and topography resembled those of placental villi. Systematic review of the histologic features in other lungs with marked emphysema revealed a spectrum of similar changes and suggested that the lesion in our patients may be a complication of bulla formation and is most likely the clinico-pathologic analog of the "vanishing lung" syndrome (idiopathic giant bullous emphysema).

Adult↗

PubMed1995

The pancornulins: a group of small proline rich-related cornified envelope precursors with bifunctional capabilities in isopeptide bond formation.

In this report, the pancornulins are identified as members of the spr (small, proline-rich) multigene family by amino acid sequence and mass spectrometry analyses. One of the pancornulins (14.9 kDa) is identical to the protein predicted by spr-1 clone 128. The other pancornulins (16.9 kDa and 22 kDa) are novel members of the spr family. Immunoelectron microscopy of purified cornified envelopes with a pancornulin-specific antibody established these proteins more definitively as cornified envelope precursors. In addition, two-dimensional electrophoretic analyses of keratinocyte extracts labeled enzymatically with dansylcadaverine (to identify amine acceptors) or dansylPGGQQIV (to identify amine donors) showed that both glutamine and lysine residues within the pancornulins participate in the isopeptide linkage characteristic of cornified envelope formation. These results contrasted with those obtained using involucrin, a prominent cornified envelope protein shown capable of acting only as an amine acceptor in this system. Novel partial cDNAs obtained after reverse transcription and polymerase chain reaction amplification of total messenger RNA with pancornulin-specific primers suggest that the spr multigene family may be even larger than previously described. The bifunctional reactivity of the pancornulins in cross-linking and the large number of family members identified to date suggest that the pancornulins and other spr-1-related proteins may be more important in cornified envelope formation than previously considered, perhaps functioning as "bridge" molecules during the early phases of cornified envelope assembly.

Amino Acid Sequence↗

PubMed1995

Congenital cystic adenomatoid malformation of the lung: insights into the pathogenesis utilizing quantitative analysis of vascular marker CD34 (QBEND-10) and cell proliferation marker MIB-1.

Congenital cystic adenomatoid malformation (CCAM) encompasses a spectrum of variably cystic developmental anomalies of the lung histologically characterized by immature lung tissue. The pathogenesis is uncertain, but many investigators favor a maturation arrest in bronchopulmonary development. To investigate this hypothesis, the vascular development and proliferation capacity of lung tissue with CCAM type I from nine infants ranging in age from 20 weeks gestation to 42 days old were studied immunohistochemically utilizing CD34 for the former and MIB-1 for the latter. Both markers were quantitated on an image analysis system. CCAM was hypovascular with a mean vascular index of 20.05% +/- 6.58 compared to 40.06% +/- 4.19 for the age-matched controls (P < 0.000001). The proliferation index of both epithelial and mesenchymal components was higher in CCAM (10.46 +/- 3.48) than in control tissue (7.14 +/- 1.88; P < 0.012). In contrast to the control lung tissue which showed a remarkable synchrony between the vascular development and proliferation throughout the parenchyma, focal asynchrony between the proliferation of the epithelial and stromal components was noted in CCAM. The vascularity in CCAM corresponds to that seen in early gestation. The cellular proliferation in CCAM is higher than in full-term infants and corresponds to late second trimester or early third trimester fetuses. These findings support the proposed pathogenesis of a maturation defect in lung embryogenesis.

Antigens, CD34↗

PubMed1993

Thrombin stimulates melanoma tumor-cell binding to endothelial cells and subendothelial matrix.

Thrombin has been shown to activate tumor-cell adhesion to platelets, fibronectin and von Willebrand factor 2- to 3-fold in vitro, and enhance metastasis 10- to 156-fold in vivo. We therefore elected to determine whether thrombin binds to tumor cells and whether thrombin-treated tumor cells enhance their adhesion to endothelial cells, the first barrier to tumor invasion and metastasis. Thrombin-treated human and hamster melanoma cells (SK-Mel-28 and HM-29) enhanced their adhesion to bovine aortic endothelial cells 2.1- to 2.3-fold, respectively. Similar results were obtained with bovine capillary endothelial cells. Thrombin activation of tumor cells was rapid, reaching its peak 15 min after thrombin activation; and transient, declining to baseline levels by 60 min. 125I-thrombin bound to both SK-Mel-28 and HM-29 cells in a saturation-dependent manner, was inhibitable by unlabelled thrombin, and could be 90% washed away with buffer following 30 min of incubation. Electron microscopy of tumor cells bound to fibronectin-coated millipore filters revealed adhesion of naive as well as thrombin-treated tumor cells to endothelial cells and subendothelial matrix between endothelial cells. Neither mode of adhesion was preferentially enhanced by thrombin-treated tumor cells. Both naive and thrombin-treated SK-Mel-28 cells had the adhesive ligand integrin receptors: alpha 3 beta l (fibronectin, laminin, collagen); alpha 5 beta l (fibronectin); alpha v beta x (vitronectin). Receptors for the beta 2 integrin family (LFA-I and Mac-I) were not found, nor were receptors of the beta 3 integrin family, GPIIIa. The receptor ligands fibronectin and vitronectin were present. None of the above receptors or ligands increased their density or appeared de novo after thrombin stimulation. Thus, 2 melanoma cell lines have thrombin receptors which, when occupied, lead to enhanced adhesion of tumor cells to endothelium and subendothelial matrix.

Animals↗

PubMed1993

Neonatal hemochromatosis associated with maternal autoantibodies against Ro/SS-A and La/SS-B ribonucleoproteins.

Liver disease in the fetus and neonate may be associated with maternal Sjögren's syndrome (neonatal lupus erythematosus). The infant of a mother with Sjögren's syndrome and high anti-Ro/SS-A and anti-La/SS-B antibody titers presented at 2 1/2 weeks of age with overwhelming hepatic insufficiency and died at 6 weeks of age. Autopsy confirmed the antemortem diagnosis of neonatal hemochromatosis. We discuss the possibility of a relationship between these two conditions.

Adult↗

PubMed1993

Canine exposure to Borrelia burgdorferi and prevalence of Ixodes dammini (Acari: Ixodidae) on deer as a measure of Lyme disease risk in the northeastern United States.

Surveillance programs that identify areas where both the vector (Ixodes dammini) and etiologic agent (Borrelia burgdorferi) are present may identify the risk of Lyme disease and its spread earlier and more accurately than do programs relying on any single method, particularly human case reports. Hunter-killed deer (n = 1,204) from 22 counties in Maryland, Massachusetts, New Hampshire, New York, and Pennsylvania were examined in fall 1989 and all ectoparasites were identified. The following spring, canine sera (n = 884) were obtained from these sites, which included known endemic areas and those where Lyme disease is uncommon, and tested by enzyme-linked immunosorbent assay. Regression analysis of canine seroprevalence versus tick prevalence on deer from the same counties demonstrate a significant positive linear relationship. Sites were designated as low-, moderate-, or high-risk counties based upon their position on the regression curve. The geographic distribution of the sites correlated well with the distribution of known Lyme disease endemic and nonendemic areas. Locations were also identified where Lyme disease may be emerging. The positive relationship between measures of vector and pathogen abundance determined in this study permits public health workers to identify endemic and potentially endemic areas independently of human case reports.

Animals↗

PubMed1993

Cholestatic hepatitis in children infected with the human immunodeficiency virus.

A distinct clinical syndrome of cholestasis and hepatitis occurred during early infancy in seven infants with perinatally acquired human immunodeficiency virus 1 infection. In five infants hepatitis was the first manifestation of human immunodeficiency virus 1 infection. The median age of onset of hepatitis was 7 months (range, 5 to 10 months). The mean total bilirubin concentration at presentation was 7.4 mg/dl (range, 3.9 to 11 mg/dl), the mean aspartate aminotransferase was 1512 IU/liter (range, 782 to 2960 IU/liter) and the mean alanine amino-transferase 512 IU/liter (range, 92 to 1247 IU/liter). The absolute CD4 count at the time of onset of hepatitis ranged from 191 to 2298 cells/mm3 (mean, 766 cells/mm3). Six of the seven children died within 12 weeks of onset of hepatitis, three as a result of complications of Pneumocystis carinii pneumonia, and two died of complications secondary to cytomegalovirus. In only one infant was the cause of death the direct consequence of liver failure. The seventh infant died 17 months after the onset of hepatitis of dilated cardiomyopathy. No specific etiologic agent has been identified as the cause of cholestatic hepatitis in these infants. In situ hybridization studies to detect human immunodeficiency virus 1 messenger RNA was negative in the liver tissue obtained at biopsy and autopsy in five of the samples tested.

Alanine Transaminase↗

PubMed1992

Brainstem glioma after radiation therapy for acute myeloblastic leukemia in a child with Down syndrome. Possible pathogenetic mechanisms.

A 13-year-old boy with Down syndrome (DS) had a brainstem glioma confirmed at autopsy, 10 years after receiving prophylactic cranial irradiation for acute myeloblastic leukemia. There is no clear association of brain tumors with DS; despite a reported link between leukemia and glioma, a causal association with radiation therapy is more likely.

Adolescent↗

PubMed1992

Detection of substrates of keratinocyte transglutaminase in vitro and in vivo using a monoclonal antibody to dansylcadaverine.

A method providing more sensitive detection of transglutaminase substrates was developed to localize transglutaminase activity in tissue and to identify in vivo substrates in epidermal extracts. The enhanced sensitivity of this method was achieved via the generation of a monoclonal antibody (designated E7) made to dansylcadaverine. Transglutaminase substrates were visualized by western blot after a 1-min incubation with dansylcadaverine in contrast to the 2 h required when [14C]putrescine incorporation was measured by autoradiography of SDS-polyacrylamide gels. In addition, putative substrates not apparent using conventional methods were readily detected by western analysis. An ELISA assay to measure transglutaminase activity showed similar sensitivity to the traditional radiometric assay (Lorand et al., 1972). The correlation between the ELISA procedure and the radiometric assay was high (r2 = 0.924). Strips of neonatal human and mouse skin incubated in dansylcadaverine-supplemented culture medium were used to localize enzyme activity and to detect substrates in vivo. Transglutaminase activity was demonstrated at the cellular periphery in the upper spinous and granular cell layers of the epidermis. Substrates detected in epidermal extracts were similar to those detected using the in vitro assay. This technique allows for highly sensitive and nonradiometric analysis of both enzymatic activity and the substrates involved. The extension of this methodology to an in vivo system is the first demonstration of a system in which the dynamics of cornified envelope assembly may be further studied.

Animals↗

PubMed1992

Sinonasal small cell neoplasm developing after radiation therapy for retinoblastoma: an immunohistologic, ultrastructural, and cytogenetic study.

Patients with retinoblastoma have an increased risk of developing second primary tumors. Only a few examples of sinonasal small cell neoplasms developing after radiation therapy for retinoblastoma have been reported. We report one such case that developed 18 years after treatment for retinoblastoma. Histologic examination revealed a small, blue, round cell tumor without rosettes or cytoplasmic glycogen. Immunohistochemically, the tumor cells were positive for neuron-specific enolase, synaptophysin, and S-100 protein, but negative for epithelial and mesenchymal markers, suggesting that this was a primitive neuroectodermal tumor. Cytogenetic studies of this tumor failed to reveal the chromosome 13 abnormality typical of retinoblastoma and the t(11:22) translocation typical of the group of peripheral neuroepitheliomas.

Adult↗

PubMed1992

Lymphoma of ovary with stromal luteinization, presenting as secondary amenorrhea.

A case of primary lymphoma of the ovary with extensive stromal luteinization is presented. Immunohistochemical markers that work satisfactorily in fixed tissues allowed a diagnosis of B cell lymphoma to be made on formalin-fixed tissue sections. Immunohistochemical analysis of frozen tissue and genotypic analysis confirmed the diagnosis of B cell lymphoma. By electron microscopy two populations of cells, including large atypical lymphoid cells and luteinized stromal cells, were identified. Presentation with amenorrhea and resumption of menstrual periods after removal of the tumor suggested the possibility of functional activity in the luteinized stromal cells. Stromal luteinization has not been previously described in primary ovarian lymphoma.

Adult↗