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J Forteza

Publications and source records attributed to J Forteza.

At least 37 records · Page 2Linked to original sources
PubMed2000

Assessing microsatellite instability with semiautomated fluorescent technology: application to the analysis of primary brain tumors.

The replication error phenotype, revealed by the observation of widespread microsatellite instability (MIN), has been identified as a new mechanism of cancer susceptibility, and the comparison of the allele sizes of polymorphic microsatellite repeats between normal and tumor DNA is now frequently undertaken in colorectal and other human neoplasias. The lack of precise characterization of the electrophoretic profiles of microsatellites is one of the main sources of discord between the rate of MIN reported for the same type of tumor by different investigators. The recent introduction of fluorescent-based semiautomated microsatellite analysis allows a more accurate size comparison, but one or more artificial peaks, generated during polymerase chain reaction (PCR) and/or electrophoresis, are frequently detected along with the true allele peaks. The aim of this study was to characterize the most frequent artificial extra peaks in the short tandem repeats (STRs) used by us to assess MIN in human cancers. We analyzed eight microsatellite loci in 113 primary brain tumors. HumFibra/FGA exhibited the most frequent extra peak formation. For each microsatellite there is a characteristic pattern of artifact formation which must be recognized to avoid a false-positive diagnosis of MIN.

Automation↗
PubMed2000

Low frequency of replication errors in primary nervous system tumours.

OBJECTIVES: Automated DNA technology was used to analyze the incidence of microsatellite instability (MIN) among the most frequent types of adult primary CNS tumours and to determine its relation with clinicopathological characteristics. METHODS: Fifty six gliomas, 32 meningiomas and 11 schwannomas were screened for size changes at eight microsatellite loci using fluorescent polymerase chain reaction (PCR) followed by fragment analysis in an automated sequencer. A tumour was considered as MIN+ when a different electrophoretic pattern between constitutional and tumour DNA was evidenced in one or more microsatellite markers and as replication error positive (RER+) when at least 25% of the markers analyzed (2/8) showed instability. The MIN phenotype was correlated with relevant clinical and pathological parameters. RESULTS: Globally, instability was found in 19/767 analyses (2.47%), with a higher rate among tetranuceotide than dinucleotide repeats (chi(2) test, p=0.018). Ten gliomas (17.9%), two meningiomas (6.3%), and two schwannomas (18.2%) were MIN+, whereas one glioma (1.8%), two meningiomas (6.3%), and one schwannoma (9.1%) were classified as RER+. A possible association between microsatellite instability and a shorter duration of clinical course was found in meningiomas. The MIN+ phenotype was more frequent in spinal than intracranial schwannomas (Fisher's exact test, p=0.018). No other significant association with clinical or histological features was detected. CONCLUSIONS: Although microsatellite instability can be demonstrated at a low rate in some primary CNS tumours, a true replication error phenotype (revealed by widespread microsatellite instability at numerous loci) is uncommon and unlikely to play an important part in the pathogenesis of these neoplasms. This form of instability was more frequent in tetranucleotide than in dinucleotide repeats. To our knowledge, this is the first report of MIN in schwannomas, where it was associated with the spinal localisation of the tumour.

Adult↗
PubMed2000

Increased expression of growth hormone and prolactin receptors in hepatocellular carcinomas.

The liver is an essential target tissue for growth hormone (GH) and prolactin (PRL). The aim of this study was to determine the in situ expression of growth hormone receptor (GHR) and prolactin receptor (PRLR) in hepatocellular carcinomas and to compare the results with normal liver. For this purpose, in situ hybridization (ISH) and immunohistochemical techniques were performed and several tests were conducted to validate the results. By radioactive ISH, all the hepatocellular carcinomas studied showed labeling for GHR and PRLR mRNAs. Relative expression levels, determined by computer-assisted microdensity, were higher in hepatocellular carcinomas than in normal liver. Immunohistochemistry led us to confirm the constant expression of both receptor proteins in hepatocellular carcinomas and normal liver and to demonstrate their localization not only in the cytoplasm but also in the nucleus. These results confirm that the liver is a major GH and PRL target tissue and suggest that in hepatocellular carcinomas the proliferative effects of these hormones may be increased by a higher expression of their receptors.

Adult↗
PubMed2000

Value of MIB-1 labelling index (LI) in gliomas and its correlation with other prognostic factors. A clinicopathologic study.

BACKGROUND: In recent years, the monoclonal antibody MIB-1 has become the main factor to measure the proliferative potential of glial tumors. This antibody is equivalent to Ki-67, which is used in frozen sections, and reacts with a nuclear protein that is expressed through the cell cycle. We have investigated the value of MIB-1 Labelling Index (LI) as an independent prognostic factor in gliomas and its relationship with clinical and pathological parameters. METHODS: MIB-1 LI was determined in 139 gliomas by using the Streptavidin-Biotin Complex (SBC) immunohistochemical method. MIB-1 LI immunoreactivity was measured with an automatic cell counting system. Survival was studied by using the Kaplan-Meier bivariant analysis and Cox multivariant regression. RESULTS: In bivariant analysis MIB-1 LI increased with age, histological grade and a supratentorial lateral location. Only size and tumor grade were significant in Cox regression. CONCLUSIONS: Perhaps this proliferation marker is influenced by many factors which reduce its value as an isolated prognostic parameter.

Antibodies, Monoclonal↗
PubMed1999

Primary anaplastic large cell lymphoma of the central nervous system.

Central nervous system (CNS) involvement is extremely rare in anaplastic large cell lymphoma (ALCL), and in children only isolated cases have been reported, mainly as secondary CNS involvement. A case of fatal primary ALCL of the brain in a 13-year-old white boy is reported. Magnetic resonance imaging of the brain showed decreased absorption in T1- and T2-weighted image showed a hyperintense signal in the right parietal lobe and 2 masses in the right frontal lobe. A frontal lobe biopsy showed a pleomorphic neoplasm diffusely infiltrating the brain parenchyma and composed of large cells with bizarre, often polylobated or horseshoe-shaped nuclei. Immunohistochemical stains showed diffuse strong positivity for CD30, anaplastic lymphoma kinase protein (ALK-1), p80, leucocyte common antigen, CD45RO (UCHL1), and focal staining for epithelial membrane antigen. Immunostainings for cytokeratins, monocyte-macrophage, and B-cell markers were negative. Epstein-Barr virus latent membrane protein was not detected. To the best of our knowledge, there is only 1 case of primary ALCL of the brain in childhood previously reported in the literature. Before the biopsy, both cases were clinically misdiagnosed as mycobacterial CNS infection. Therefore, primary ALCL should also be included in the differential diagnosis when a mycobacterial CNS infection is suspected in pediatric patients; a careful cytological evaluation of the cerebrospinal fluid or cerebral biopsy are essential for an accurate diagnosis.

Adolescent↗
PubMed1998

Iris metastasis from endometrial carcinoma.

PURPOSE: To report a case of metastasis to the iris from endometrial carcinoma. METHOD: Case report. A 67-year-old woman with a history of endometrial carcinoma and local recurrence after surgery presented 11 months later with two yellow-pink nodules on the iris of the right eye. RESULTS: Systemic medical evaluation demonstrated no other metastases. The iris tumors were removed surgically, and histology demonstrated adenocarcinoma consistent with endometrial carcinoma. CONCLUSIONS: Endometrial carcinoma can metastasize to the iris. This possibility should be considered because the frequency of endometrial carcinoma is increasing.

Adenocarcinoma↗
PubMed1998

Molecular features in a biphenotypic small cell sarcoma with neuroectodermal and muscle differentiation.

We report a case of a 13-year-old girl with soft tissue sarcoma of the hand, which showed muscle and neuroectodermal immunophenotypes. Molecular studies were performed on RNA collected from fine-needle aspiration (FNA) cytology and peripheral blood samples by nested reverse transcriptase-polymerase chain reaction (RT-PCR) and Southern blot analysis. This biphenotypic tumor showed simultaneous expression of EWS-FLI1 and PAX3-FKHR transcripts, specific of Ewing family tumors and alveolar rhabdomyosarcoma, respectively. Although childhood sarcomas with simultaneous muscle and neural differentiation have been described to have EWS-FLI1 transcripts, there are no reports of tumors with both transcripts. Cytological specimens are a good source of RNA for molecular studies.

Adolescent↗
PubMed1996

Pathological, immunological, and molecular features of Hodgkin's disease associated with HIV infection. Comparison with ordinary hodgkin's disease.

The aim of the present study was to analyze in a series of 24 HIV-positive Hodgkin's disease (HD) patients the morphological and immunological features, the presence of rearrangements in the immunoglobulin heavy chain (IgH) gene, expression of the Epstein-Barr virus (EBV) latent membrane protein-1 (LMP-1), and the existence of deletions in the intracytoplasmic domain of the LMP-1 gene. The results obtained were compared with those from a parallel series of 56 patients with ordinary HD. Briefly, comparison of the two series showed a predominance of unfavorable histological subtypes in HIV-positive HD patients. The mixed cellularity subtype was more frequent in HIV-positive than in HIV-negative HD patients: the difference in percentage was statistically significant (p = 0.04). Neoplastic cell-rich cases were significantly more frequent (p = 0.40) in HIV patients (59%) than in ordinary HD patients (34%). In 25% of HIV-infected and in 14% of ordinary HD patients, the neoplastic cells were CD20+, a difference that was not statistically representative. Clonal IgH rearrangements were detected in 33% of HIV-infected patients and in 23% of ordinary HD patients, a nonsignificant difference. LMP-1 expression was detected in 100% of HIV-positive patients and in 57% of ordinary HD patients (p = 0.004). A 30-base-pair deletion in the carboxy-terminal domain of the LMP-1 gene was found in 16 of 18 HIV-infected patients (89%), whereas it was identified in only 8 of 25 ordinary HD patients (32%) (p = 0.008). In conclusion, HD in HIV-infected patients as compared with HD in HIV-negative individuals is associated with morphological features of aggressivity, with a higher frequency of neoplastic cells, and with constant LMP-1 expression. The fact that LMP-1 is expressed in all HIV-infected patients suggests that EBV plays an etiological role in the pathogenesis of HIV-associated HD. Furthermore, the presence of EBV strains carrying deletions near the 3' end of the LMP-1 gene in the majority of cases may be related with the morphological and clinical aggressivity of HD in immunocompromised patients.

Adult↗
PubMed1995

Neural cell adhesion molecule immunoreactivity in Merkel cells and Merkel cell tumours.

We have analysed the expression of the neural cell adhesion molecule (NCAM) in normal Merkel cells of pig and human skin, and in nine neuroendocrine carcinomas of the skin (Merkel cell carcinomas). NCAM immunoreactivity was observed in virtually all Merkel cells, both in epidermis and vibrissae of pig snout skin and in human epidermis. Immunostaining surrounded the entire surface of Merkel cells and was not restricted to the contact areas between Merkel cells and nerve terminals. All Merkel cell carcinomas studied were also positive for NCAM. The immunostaining pattern of the tumour cells was similar to that observed in normal Merkel cells; the immunoreactivity was confined to the cell membranes. These results suggest that NCAM may be used as an immunohistochemical marker for both Merkel cells and Merkel cell tumours.

Animals↗
PubMed1995

Mixed strumal and mucinous carcinoid tumor of the ovary.

The first example of mixed strumal and mucinous carcinoid tumor of the ovary is reported. The vast majority of the tumor was composed of carcinoid cells arranged in a trabecular-insular configuration admixed with obvious thyroid follicles. In addition, glands lined by mucin-producing cells were seen in some areas. A transition from the strumal carcinoid component to the mucinous glands was seen. Immunohistochemical studies showed that the strumal and mucinous carcinoid components were positive for chromogranin A, serotonin, and vasoactive intestinal polypeptide, clearly demonstrating that both were neuroendocrine in nature.

Adenocarcinoma, Mucinous↗
PubMed1994

Distribution of prothymosin alpha in rat and human adrenal cortex.

BACKGROUND: Prothymosin alpha (ProT) is a polypeptide widely distributed in the organism and expressed by cell types with a high proliferative capacity. The aim of the current work was to investigate if ProT was localized in the progenitor compartment of the adrenal cortex which, following the cell migration theory, corresponds to the zona glomerulosa. METHODS: We studied by immunohistochemical and in situ hybridization methods the distribution of ProT in rat and human adrenal cortex. Immunohistochemical techniques for the study of the proliferating cell nuclear antigen (PCNA) and incorporation of 5-bromo-2'-deoxyuridin during DNA synthesis were also done. Immunoelectron microscopic procedures were performed to determine the exact subcellular localization of ProT. RESULTS: ProT was found in the zona glomerulosa cells, but not in the cells of the remaining cortical layers (zonae fasciculata and reticularis). Glomerulosa cells showed immunostaining for ProT only in the nuclei, excluding the nucleoli. Variability in immunostaining intensity was found between different glomerulosa cells. In situ hybridization of ProT mRNA confirmed that ProT synthesis in adrenal cortex occurs only in the zona glomerulosa. The results obtained for proliferating cell nuclear antigen and incorporation of 5-bromo-2'-deoxyuridin confirmed that adrenocortical proliferation occurs in the zona glomerulosa. Ultrastructural immunocytochemistry showed labelling for ProT over the euchromatin, but not on the heterochromatin aggregations nor the nucleoli. CONCLUSIONS: The results presented here: 1) support the migration theory for the adrenocortical cell renewal, 2) demonstrate that ProT is present in the nuclei of proliferating cells (being associated with euchromatin), and 3) suggest that the study of ProT expression would be useful in distinguishing cycling from resting cells.

Adrenal Cortex↗
PubMed1994

Waldeyer ring lymphomas. A clinicopathological study of 79 cases.

Waldeyer ring lymphomas belong to a category of tumours which has not yet been fully defined. Their relation to mucosa-associated lymphoid tissue (MALT) and other extranodal lymphomas remains largely unknown. We performed a clinicopathological retrospective study of 79 patients, and compared them with a series of MALT and nodal lymphomas. Tumours from the nasopharynx and palatine tonsil showed similar histological profiles, with a predominance of large B-cells. Centroblastic lymphomas constituted the largest group (n = 45), followed by those of centrocytic type (9) with smaller groups of centroblastic-centrocytic (5) and Hodgkin's lymphomas (2). Three monocytoid B-cell lymphomas were identified. Only one case could be classified as MALT lymphoma. The frequency of bcl-2 expression in large B-cell tumours of Waldeyer's ring has an intermediate range between large B-cell lymphomas occurring in mucosal and nodal locations. Epitheliotropism was present in all low-grade cases, and was therefore not a useful marker in the identification of potential MALT lymphomas in contrast with other mucosal sites. Comparative survival studies showed significant overall differences between Waldeyer ring lymphomas, MALT and nodal cases. These disappeared after taking stage and histological grade into account. We conclude that Waldeyer ring lymphomas show distinctive features, mainly in terms of histological distribution and immunophenotype. The key factor determining their behaviour could be their different spreading capability. These findings suggest that extranodal lymphomas are heterogeneous, and indicate the need for additional efforts to clarify this.

Adolescent↗
PubMed1994

Functional, histologic, and ultrastructural study of the protective effects of verapamil in experimental ischemic acute renal failure in the rabbit.

The present study was performed in vivo in rabbits to evaluate the functional and morphologic effects of verapamil in a model of ischemic acute renal failure (ARF). Particularly impressive was the ultrastructural integrity of renal tubules in the animals exposed to both ischemia and verapamil. Three groups were studied: Group A: no ischemia; Group B: renal ischemia alone; and Group C: renal ischemia with verapamil. Creatinine clearance was higher in Group C (0.77 mL/min/kg) compared to Group B (0.13 mL/min/kg) at 24 h of reperfusion (p < .005) as well as at 48 and 72 h (0.73 mL/min/kg) vs. 0.35 mL/min/kg; p < .05 and 0.90 mL/min/kg vs. 0.46 mL/min/kg; p < 0.05, respectively). Light microscopic evaluation of Group C rabbits revealed significantly better preservation of proximal tubule (PT) brush border (p < .0005) and less desquamation of PT (p < .05) compared to Group B. Ultrastructural examination of in vivo perfused kidneys also demonstrated decreased loss of microvilli of PT (p < .0005) as well as less cellular edema (p < .005), fewer cells with apical PT membrane rupture (p < .01), better preservation of mitochondria (p < .005), less flattening of the PT basolateral labyrinth (p < .05), and fewer hypertrophic actin bands at the basal surface of PT epithelial cells (p < .05). These results suggest that verapamil markedly attenuates PT morphologic injury in a rabbit model of reversible ischemic ARF. The functional protection observed in these studies may be related, in part, to the improved structural integrity of the renal tubules. Renal transplantation and anticipated renal ischemia (i.e., surgical interventions) are two important situations where treatment with verapamil or other calcium channel blockers may prove to be clinically beneficial.

Acute Kidney Injury↗
PubMed1993

Immunohistochemical location of prothymosin alpha in regenerating human hepatocytes and hepatocellular carcinomas.

In the present paper we analysed the presence of prothymosin alpha (ProT) in human liver. In normal liver, ProT immunostaining was found in the nuclei of bile duct cells, but not in the hepatocytes. In contrast an intense immunoreactivity was observed in regenerative hepatocytes of chronic hepatitis, cirrhosis and in hepatocellular carcinomas. In all cases the immunostaining was restricted to the nuclei, but the nucleoli were always negative. Similar results were obtained for proliferating cell nuclear antigen. These findings confirm that ProT is related to cell proliferation and provides a new immunohistochemical proliferation marker for routinely processed samples.

Carcinoma, Hepatocellular↗
PubMed1993

Tissue concentrations of prothymosin alpha: a novel proliferation index of primary breast cancer.

In 71 patients with classic invasive ductal carcinomas, levels of prothymosin alpha (PT alpha), as assayed by a radioimmunoassay that detects thymosin alpha 1 (the NH2-terminal fragment of PT alpha), were significantly greater in tumour samples than in normal breast tissue. PT alpha levels were correlated with (a) the number of positive axillary lymph nodes (rs = 0.5384, P < 0.01), and (b) the percentage of tumour cells in the S or G2/M phase as assessed by flow cytometry (rs = 0.5027, P < 0.01). Since the beginning of this study in 1989, 21 patients have presented distant metastases, all of whom were previously shown to have tumour PT alpha levels greater than 124 ng of thymosin alpha 1/mg protein. The present report indicates that PT alpha might be used to identify breast cancer patients at high risk for distant metastases.

Adult↗