[Reinterpretation of the Malpighian body in light of the existence of a single glomerular arteriole (Trabucco and Marquez)].

Introduction: In 1842 William Bowman described the microvascular system of the Malpighian body. Electron microscopic studies definitively revealed the spatial structure of its mesangial-capillary-epithelial component. In 1952-54 Trabucco and Marquez challenged the ideas of Bowman, demonstrating the existence of a single glomerular arteriole.

PTEN protein expression correlates with PTEN gene molecular changes but not with VEGF expression in astrocytomas.

PTEN gene (10q23) is a relevant tumor suppressor gene whose protein is a phosphatase involved in the control of angiogenesis of some tumors including astrocytomas. There are no studies correlating molecular changes of PTEN and the immunohistochemical expression of its protein (pPTEN) with the expression of vascular endothelial growth factor (VEGF) in astrocytomas. Fifty-six surgically resected brain gliomas, 10 grade 2, 16 grade 3, and 30 grade 4, were studied by a combined approach, consisting of (1) PCR analysis using four microsatellite markers against the PTEN gene region (10q23), (2) the FISH technique to test chromosome 10 using a pericentromeric probe, and (3) immunohistochemical evaluation of pPTEN and VEGF.

Prognostic impact of P53 status in Ewing sarcoma.

Background: Disease stage at the time of diagnosis and response to therapy are the main prognostic factors for patients with Ewing sarcoma or peripheral neuroectodermal tumor (ES/PNET). The primary genetic alteration in ES/PNET, the fusion of the EWS gene with FLI1 or ERG, is diagnostically highly specific for these tumors, and molecular variation in the structure of the EWS-FLI1 fusion gene also is of prognostic significance. In contrast, secondary genetic alterations, such as P53 alterations, are relatively uncommon in ES/PNET, and their prognostic impact has not been extensively studied.

Association of EWS-FLI1 type 1 fusion with lower proliferative rate in Ewing's sarcoma.

The Ewing's sarcoma (ES) family of tumors, including peripheral neuroectodermal tumor (PNET), is defined genetically by specific chromosomal translocations resulting in fusion of the EWS gene with a member of the ETS family of transcription factors, either FLI1 (90-95%) or ERG (5-10%). A second level of molecular genetic heterogeneity stems from the variation in the location of the translocation breakpoints, resulting in the inclusion of different combinations of exons from EWS and FLI1 (or ERG) in the fusion products. The most common type of EWS-FLI1 fusion transcript, type 1, is associated with a favorable prognosis and appears to encode a functionally weaker transactivator, compared to other fusion types.

Decrease of apoptosis rate in patients with renal transplantation treated with mycophenolate mofetil.

Background/aims: Mycophenolate mofetil (MMF) is a powerful immunosuppressant that inhibits the proliferation of lymphocytes by blocking the enzyme inosine monophosphate dehydrogenase. MMF prevents acute graft rejection in organ transplants. The aim of this investigation is to study whether MMF has any influence on apoptosis and proliferation rates of cells other than lymphocytes.

Utility of immunophenotypic and immunogenotypic analysis in the study of necrotic lymph nodes.

We report a case of complete lymph node necrosis. No specific aetiology could be determined by morphology, but a B lymphoid population and clonal rearrangement of the immunoglobulin heavy chain gene were demonstrated in immunophenotypic and immunogenotypic studies performed using DNA extracted from paraffin embedded necrotic tissue. In the setting of lymph node necrosis, we suggest that immunohistochemical and gene rearrangement studies may provide additional diagnostic information.

FNAC guided by computed tomography in the diagnosis of primary pancreatic adenosquamous carcinoma. A report of three cases.

Background: Pancreatic adenosquamous carcinoma (ASqC) is an unusual histologic subtype of nonendocrine neoplasia of the pancreas. Although fine needle aspiration cytology (FNAC) is now accepted as a reliable procedure for the diagnosis of pancreatic malignancies, many of these unusual tumors are still diagnosed after surgery or at necropsy.

Cases: Between January 1995 and July 1996, 3 of 35 primary pancreatic malignant tumors were diagnosed as ASqC based on computed tomography-guided FNAC.

Ewing family tumors: potential prognostic value of reverse-transcriptase polymerase chain reaction detection of minimal residual disease in peripheral blood samples.

In more than 95% of patients, the Ewing family of tumors (ET) has chimeric transcripts caused by fusion of the EWS gene to either FLI1 or ERG. The presence of specific EWS-FLI1 or EWS-ERG transcripts in peripheral blood (PB) samples of patients being treated for ET was prospectively evaluated, and these data were correlated to their clinical status. The authors studied 113 PB samples from 28 patients with ET.

CD44v6 expression is related to progression in renal epithelial tumours.

Aims: Expression of CD44 variant isoform including exon 6 has been associated to tumour progression in several carcinomas. However, no studies have been performed to assess the prognostic value of the expression of this marker in renal cell tumours.

Methods And Results: We studied 58 renal cell tumours.

EWS-FLI1 fusion transcript structure is an independent determinant of prognosis in Ewing's sarcoma.

Purpose: More than 90% of Ewing's sarcomas (ES) contain a fusion of the EWS and FLI1 genes, due to the t(11;22)(q24;q12) translocation. At the molecular level, the EWS-FLI1 rearrangements show great diversity. Specifically, many different combinations of exons from EWS and FLI1 encode in-frame fusion transcripts and result in differences in the length and composition of the chimeric protein, which functions as an oncogenic aberrant transcription factor.

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.

Quinapril inhibits c-Myc expression and normalizes smooth muscle cell proliferation in spontaneously hypertensive rats.

A number of data suggest that angiotensin II-dependent activation of the protooncogene c-myc participates in the proliferative response of smooth muscle cells (SMC) of rats with spontaneous hypertension (SHR). We therefore investigated the effects of chronic treatment with the angiotensin converting enzyme (ACE) inhibitor quinapril on the oncoprotein c-Myc and the proliferating cell nuclear antigen cyclin A in SMC of small intramyocardial arteries from the left ventricle of SHR. The expression of c-Myc and cyclin A was assessed by immunocytochemical analysis.

Role of endomyocardial biopsy in the diagnosis of chronic rejection in human heart transplantation.

To assess the pathologic findings observed in the setting of post-transplant graft atherosclerosis, we have studied 18 endomyocardial biopsies (EMB) from 18 heart-transplanted patients collected at the same time that a coronary angiography (CA) showed changes consistent with graft atherosclerosis. Twenty-two EMB from patients with heart transplant with normal CA were used as controls. In spite of the small size of the sample, the number of acute rejection (AR) episodes correlated with the appearance of graft atherosclerosis (p < 0.

Massive ovarian oedema.

Eighteen cases of massive ovarian oedema are presented. The age of patients averaged 26 years and 16 presented with an acute abdomen. Hormonal symptoms included virilism in three cases and one with precocious pseudopuberty.

Angiotensin converting enzyme inhibition prevents polyploidization of cardiomyocytes in spontaneously hypertensive rats with left ventricular hypertrophy.

Polyploidization of cardiomyocyte nuclei is a physiological phenomenon that increases in pathological conditions such as myocardial hypertrophy. The purpose of this study was to evaluate the potential benefit of the angiotensin converting enzyme (ACE) inhibitor quinapril in reversing the polyploidization of cardiomyocyte nuclei in spontaneously hypertensive rats (SHR) with established left ventricular hypertrophy (LVH). Sixteen week-old male SHR were treated with oral quinapril (average dose 10 mg/kg per day) for 20 weeks.

Eosinophilic myocarditis in patients waiting for heart transplantation.

We report three patients waiting for heart transplantation who suddenly worsened clinically. All three explanted hearts showed a myocarditis with a dense eosinophilic infiltrate. Follow-up biopsies and necropsies showed no further evidence of cardiac eosinophilic infiltrates.

[Lymphoproliferative disease and cancer in the transplant patient].

According to the Spanish Cardiac Transplantation Registry, malignant neoplasm remain the fifth leading cause of death in heart transplant recipients. Skin cancers are the most common malignancies and they are frequently associated to solar keratosis, warts and keratoacanthoma. Geographic areas are high cumulative ultraviolet exposure have a greater incidence of skin cancer.

Chondroid metaplasia in the tunica media of the aorta in dogs submitted to saphenous vein aorto-cava by-pass.

We submitted twelve dogs to aorto-superior vena cava by-pass with saphenous vein. Six months later, all dogs had developed areas of chondroid metaplasia in the tunica media of the aorta, near the area of anastomosis. Three dogs also had bony metaplasia.

[Development of a computer-assisted system to teach pathologic anatomy. Preliminary results].

Background: The present study describes the implantation of an interactive teaching system to improve both the active involvement of the student and the learning quality of Pathology. The preliminary results from the evaluation of such system are also reported.

Methods: Two attitude questionnaires (rating scale) were passed to a sample of 36 students of Medicine, randomly elected.

Alterations in the extracellular matrix of the myocardium in essential hypertension.

Hypertension produces myocyte hypertrophy and increases the extracellular matrix. In order to determine the composition of the extracellular matrix we studied the hearts from 14 hypertensive patients by immunohistochemistry using antibodies against collagen I, III, IV and V, fibronectin, myoglobin, muscular specific actin, Factor VIII, CD 34 and vimentin. The myocardium showed a focal increase in fibronectin, collagen I and III and diffuse deposition of laminin, collagen IV and V.