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Biomedical subjects

M Bramerio

Publications and source records attributed to M Bramerio.

17 recordsLinked to original sources
PubMed2005

Use of radioguided surgery with [111In]-pentetreotide in the management of an ACTH-secreting bronchial carcinoid causing ectopic Cushing's syndrome.

Intraoperative [111In]-pentetreotide scintigraphy with a hand-held gamma detector probe has recently been proposed to increase the intraoperative detection rate of small neuroendocrine tumors and their metastases. We report a case of a 28-yr-old woman with ectopic Cushing's syndrome due to an ACTH-secreting bronchial carcinoid, in whom the use of radioguided surgery improved disease management. At presentation, radiolabeled pentetreotide scintigraphy was the only procedure able to detect the ectopic source of ACTH. After radiologic confirmation, the patient underwent removal of a bronchial carcinoid, with disease persistence. After surgery, pentetreotide scintigraphy showed pathologic uptake in the mediastinum not previously detected at surgery and only subsequently confirmed by radiologic studies. Despite a second thoracic exploration, hormonal, scintigraphic, and radiological evidence of residual disease persisted. Radioguided surgery was then performed using a hand-held gamma probe 48 h after iv administration of a tracer dose of radiolabeled [111In-DTPA-D-Phe1]-pentetreotide, which permitted detection and removal of multiple residual mediastinal lymph node metastases. Clinical and radiologic cure, with no evidence of tracer uptake at pentetreotide scintigraphy, was subsequently observed. The use of an intraoperative gamma counter appears a promising procedure in the management of metastatic ACTH-secreting bronchial carcinoids.

ACTH Syndrome, Ectopic↗
PubMed2004

Electroclinical, MRI and neuropathological study of 10 patients with nodular heterotopia, with surgical outcomes.

We present the results of a retrospective study on 10 patients operated on for intractable epilepsy associated with nodular heterotopia as identified by high resolution MRI. Seven patients had unilateral heterotopia, one patient had symmetric bilateral heterotopia and two patients had asymmetric bilateral heterotopia. By stereo-electroencephalogram (SEEG) (nine patients) interictal activity within nodules was similar in all cases, and ictal activity never started from nodules alone but from the overlying cortex or simultaneously in nodules and cortex. Excellent outcomes (Engel class Ia, 1987) were achieved in the seven patients with unilateral heterotopia, showing that surgery can be highly beneficial in such cases when the epileptogenic zone is carefully located prior to surgery by MRI and particularly SEEG. For the bilateral cases surgical outcomes were Engel IIa (one patient) or Engel IIIa (two patients). Histological/immunohistochemical studies of resected specimens showed that all nodules had similar microscopic organization, even though their extent and location varied markedly. The overlying cortex was dysplastic in nine patients, but of normal thickness. We suggest that nodule formation may be the result of a dual mechanism: (i) failure of a stop signal in the germinal periventricular region leading to cell overproduction; and (ii) early transformation of radial glial cells into astrocytes resulting in defective neuronal migration. The intrinsic interictal epileptiform activity of nodules may be due to an impaired intranodular GABAergic system.

Adult↗
PubMed2002

Focal cortical dysplasia: neuropathological subtypes, EEG, neuroimaging and surgical outcome.

Since the original description by Taylor, the term focal cortical dysplasia has been used to refer to a wide range of alterations of the cortical mantle. More recently, these conditions have been described from neuroimaging, neuropathological and genetic standpoints, generating several classifications. It is widely recognized that these classifications are unsatisfactory. We propose a simplified classification of focal cortical dysplasias based on easily recognized neuropathological characteristics. We retrospectively re-examined histological sections of cortex from 52 of 224 (23%) patients operated on for drug-resistant partial epilepsy in which cortical dysplasia was present but not associated with other brain pathologies except hippocampal sclerosis. Three subgroups were identified: (i) architectural dysplasia (31 patients) characterized by abnormal cortical lamination and ectopic neurones in white matter; (ii) cytoarchitectural dysplasia (six patients) characterized by giant neurofilament-enriched neurones in addition to altered cortical lamination; and (iii) Taylor-type cortical dysplasia (15 patients) with giant dysmorphic neurones and balloon cells (all but two patients) associated with cortical laminar disruption. The patients with architectural dysplasia had lower seizure frequency than those with cytoarchitectural and Taylor-type dysplasia, and the epileptogenic zone was mainly in the temporal lobe. In patients with Taylor-type dysplasia, the epileptogenic zone was mainly extratemporal, and interictal stereo-EEG was distinctive. MRI was unrevealing in 34% of patients, but distinctive signal alterations characterized most patients with Taylor-type dysplasia, while focal hypoplasia with MRI abnormalities was found in architectural dysplasia. Patients with Taylor-type dysplasia had the best outcome, with 75% seizure-free (Engel class Ia) after at least a year of follow-up compared with 50% of cytoarchitectural dysplasia and 43% of architectural dysplasia patients seizure-free. This three-category classification is based on easily recognized histopathological characteristics and avoids complicated terminology, while the distinctive ensemble of other characteristics defines clinically homogeneous groups.

Adult↗
PubMed2001

Cajal-Retzius cell density as marker of type of focal cortical dysplasia.

Cajal-Retzius cells, identified using calretinin antiserum, were studied in layer I (LI) of adult human temporal cortex from epileptic patients with Taylor's focal cortical dysplasia and architectural dysplasia, in comparison with normal cortex. Both types of dysplasia showed LI hypercellularity, but only in architectural dysplasia was the density of Cajal-Retzius cells significantly increased. A subset of Cajal-Retzius cells were reelin immunoreactive, but none were GABA positive. These findings suggest that differences in the persistence of Cajal-Retzius cells, which probably reflect different types of alteration during brain development, can assist in characterizing different forms of cortical dysplasia.

Cell Adhesion Molecules, Neuronal↗
PubMed2001

Prospective follow-up study of chronic polyneuropathy of undetermined cause.

Forty consecutive patients with chronic sensorimotor polyneuropathy of undetermined cause were followed to determine disease progression and prognosis. They had had neurological symptoms for at least 1 year before presentation. Neurophysiological examination in all patients showed chronic axonal degeneration, which was confirmed by sural nerve biopsy. Patients were reviewed every 3 months. Laboratory tests were performed every 6 months for the first 2 years and then annually. Neurophysiological examination was performed annually in all patients. Patients were followed up for at least 4 years. In no instance was a possible etiological factor detected during follow-up. The clinical and electrophysiological findings had a slowly progressive course. We suggest that patients with a chronic polyneuropathy of undetermined cause despite detailed investigations do not require further extensive and expensive laboratory tests and neurophysiological studies during follow-up.

Aged↗
PubMed2000

Inhibitory circuits in human dysplastic tissue.

PURPOSE: Different types of epilepsies and seizures depend on the nature and location of the primary disturbance and are presumably mediated by different physiopathological mechanisms. We immunocytochemically investigated possible changes in the inhibitory-aminobutyric acid (GABA)ergic system in specimens taken from four patients who underwent surgery for intractable epilepsy and presented two different types of focal cortical dysplasia in the temporal lobe. METHODS: The patients were selected on the basis of electroclinical, imaging, and routine neuropathological data: two had Taylor focal dysplasia, and two had non-Taylor dysplasia (microdysgenesia). The study was performed using antibodies against parvalbumin (PV), glutamic acid decarboxylase (GAD), and GABA-transporter 1 (GAT1). RESULTS: In the patients with Taylor dysplasia, laminar disorganization of the cortex was associated with the presence of giant neurons and ballooned cells; there was a reduced number of PV-positive neurons and terminals, the giant neurons were surrounded by clusters of PV- and GAD-positive terminals, and there was an overall reduction in GAT1. Despite the presence of cortical laminar disorganization, no giant or ballooned cells were found in the patients with non-Taylor microdysgenesia; there was a marked decrease in PV and GAD immunoreactive elements, with a patchy distribution of GAD and GAT1 immunoreactivity but no clustering of PV and GAD terminals. CONCLUSIONS: These results suggest that the two forms of cortical dysplasia are characterized by different and selective morphofunctional alterations in the GABAergic system.

Adult↗
PubMed1999

Taylor's cortical dysplasia: a confocal and ultrastructural immunohistochemical study.

In the present report we describe the neuropathological characteristics of tissue surgically resected from three patients affected by intractable epilepsy secondary to cortical dysplasia. Common features, suggestive of a focal cortical dysplasia of Taylor, were observed in all specimens. Immunocytochemical procedures were performed using neuronal and glial markers and the sections were observed at light traditional and confocal microscopes. This part of the investigation pointed out: 1. cortical laminar disruption; 2. very large neurons displaying a pyramidal or round shape; 3. ballooned cells; 4. decrease of calcium binding proteins immunoreactivity; 5. abnormal nets of parvalbumin- and glutamic acid decarboxylase-positive puncta around giant neurons but not around ballooned cells. Ultrastructural investigation on the same material provided evidence of a high concentration of neurofilaments in giant neurons and of glial intermediate filaments in ballooned cells. In addition, immunolabeled GABAergic terminals clustered around giant neurons were not found to establish synapses on their cell bodies. The present data, derived from a limited sample of patients but showing very consistent features, suggest that in Taylor's type of cortical dysplasia a disturbance of migratory events could be paralleled by a disruption of cell differentiation and maturation and by an impairment of synaptogenesis. This latter mechanism seemed to affect especially the inhibitory elements, and could account for the hyperexcitability of this tissue and thus for the high epileptogenicity of Taylor's dysplasia.

Adult↗
PubMed1998

Growth hormone and prolactin responses to corticotrophin-releasing-hormone in patients with Cushing's disease: a paracrine action of the adenomatous corticotrophic cells?

OBJECTIVE: In patients with Cushing's disease multihormonal responses to ovine corticotrophin releasing hormone (oCRH) have been detected in blood from inferior petrosal sinuses. This finding has been explained by co-secretion of other hormones, in addition to ACTH, by the pituitary adenoma itself or by paracrine effects exerted by the adenoma on normal periadenomatous pituitary cells. To assess these hypotheses we compared the presence of a CRH induced GH and/or PRL response during inferior petrosal sinus sampling to the immunohistochemical detection of PRL and GH in adenomatous tissue removed from patients with Cushing's disease. PATIENTS AND MEASUREMENTS: Twenty-two patients with Cushing's disease and two patients with ectopic ACTH syndrome due to a bronchial carcinoid were studied; each patient had undergone preoperative inferior petrosal sinus sampling for diagnostic purposes with determination of GH and PRL in addition to ACTH, before and after administration of oCRH. Immunohistochemical studies for ACTH, GH and PRL detection were carried out on adenomatous tissue removed at surgery in the patients with pituitary dependent Cushing's disease and on the carcinoid tumours from the two patients with ectopic ACTH syndrome. RESULTS: All pituitary adenomas immunostained for ACTH, and four adenomas immunostained for GH or PRL in addition to ACTH. A PRL increase in the inferior petrosal sinus after oCRH administration was found in 11 of 22 patients, but none of their tumours immunostained for PRL. Immunostaining for PRL was found in the pituitary tumours from two patients but in neither patient was there a PRL response after oCRH. A GH response was found in 13 of 20 patients in whom it was sought; no patient showed immunostaining in their tumour. GH immunostaining was found in two tumours but in neither patient was there a GH response after oCRH. The oCRH-induced increase of GH and PRL was always recorded in the dominant inferior petrosal sinus. The ACTH response to oCRH was significantly higher in patients who showed oCRH induced increases in GH and/or PRL than in patients who did not, both in terms of area under the response-curve (22,032 +/- 9876 vs. 4371 +/- 2870 ng/l/10 min; P < 0.05) or mean percentage increase above baseline (754 +/- 229% vs. 147.2 +/- 67%, P < 0.02). A significant correlation was observed between ACTH and GH responses to oCRH. The two patients with ectopic Cushing's syndrome did not show ACTH, GH or PRL increases after oCRH administration and did not show immunostaining for GH or PRL in their tumours. CONCLUSIONS: The present data do not support the hypothesis of co-secretion of hormones by the pituitary adenoma as the cause of the GH and PRL responses to ovine corticotrophin releasing hormone observed in patients with Cushing's disease; it is suggested that a different mechanism, possibly involving an interaction between the ACTH secreting adenoma and the normal periadenomatous GH and PRL secreting cells, may be responsible.

Adenoma↗
PubMed1997

[Detection of mycobacterium tuberculosis DNA using nested polymerase chain reaction in lymph nodes with sarcoidosis, fixed in formalin and embedded in paraffin].

An involvement of mycobacteria in the pathogenesis of sarcoidosis has often been hypothesized, but not confirmed reproducibly. In this study we applied a nested Polymerase Chain Reaction (PCR) to the insertion sequence IS6110 for detection of Mycobacterium tuberculosis (MT) DNA in formalin-fixed and paraffin-embedded tissues from patients with sarcoidosis, with tuberculosis and atypical mycobacteriosis confirmed by culture, and from negative control samples. MT-DNA could be detected in 2/30 samples of sarcoidosis, in 10/10 tuberculoses, in 0/5 atypical mycobacterioses and in 0/10 negative controls. Nested PCR confirmed its high sensitivity and specificity in detecting MT-DNA on archival histopathological specimens. From our results we conclude that in the granulomatous lesions of sarcoidosis MT-DNA is only sporadically demonstrable and probably it doesn't play a role in the pathogenesis of this disease.

DNA, Bacterial↗
PubMed1992

Search for Coxsackievirus B3 RNA in idiopathic dilated cardiomyopathy using gene amplification by polymerase chain reaction.

A polymerase chain reaction (PCR) amplification assay was developed to detect Coxsackievirus B3 ribonucleic acid (RNA) in blood and myocardial tissue of explanted hearts from 40 patients who underwent cardiac transplantation and in 1 normal heart. Twenty-one patients were affected by idiopathic dilated cardiomyopathy of different duration and 19 by coronary artery disease. Coxsackievirus B3 in vitro infected Vero cells and cells infected by related human enteroviruses (Coxsackievirus B2, B4, and poliovirus 1) were used as reaction controls. PCR was performed using 4 pairs of primers homologous to Coxsackie-virus B3 sequences. Three sets were located in regions of the genome conserved at nucleotide level between several enterovirus species (replicase gene, 5' noncoding region), while one was located in a Coxsackievirus B3-specific region (VP1 gene). Total RNA was prepared by acid guanidinium isothiocyanate extraction from tissue stored frozen at -80 degrees C. One microgram of total RNA was retrotranscribed with either antisense primer or with random hexanucleotide primers and then subjected to 40 cycles of amplification. PCR products were separated by electrophoresis on a 10% polyacrylamide gel, electrotransferred to a nylon membrane and then hybridized to oligonucleotide probes specific for the coxsackievirus B3 genome radiolabeled with radioactive isotope of phosphorous. All pairs of primers yielded specific amplification products when tested on Coxsackievirus B3-infected Vero cells, with a sensitivity of 1 infected cell out of 10(5) to 10(6) cells starting from 1 microgram total RNA. Primer sets for regions of Coxsackievirus B3 genome highly conserved between related enteroviral species gave positive amplification also when challenged with RNA from cells infected by Coxsackievirus B2, B4 and poliovirus 1.

Adult↗
PubMed1992

Histopathologic and molecular profile of human cytomegalovirus infections in patients with heart transplants.

From November 1985 to December 1990, 2,552 endomyocardial biopsy specimens from 209 heart transplant patients were studied. Forty-four (21%) patients developed 45 episodes of major human cytomegalovirus infection (HCMV). Human cytomegalovirus infection was primary in 13 of 44 patients. Thirty-one patients developed episodes of recurrent major infection. One patient had both primary and recurrent infections. Conventional histopathologic and immunohistochemical study, in situ hybridization, and polymerase chain reaction were used to diagnose HCMV myocardial involvement on corresponding endomyocardial biopsy specimens performed during infection. Conventional morphologic study showed typical viral inclusion bodies in four biopsy specimens. Two cases had myocyte HCMV localization with necrotizing myocarditis, whereas two had endothelial cell involvement without any inflammatory reaction. In these four biopsy specimens, immunohistochemistry showed a higher number of infected cells than that recognized by conventional histopathologic study. In situ hybridization detected infected cells with no evidence of cytopathic effect. Polymerase chain reaction gave HCMV amplification products in two additional biopsy specimens otherwise interpreted as moderate and mild rejection, respectively. Therefore, 6 biopsies showed HCMV myocardial involvement (6 of 45; 13.3%): all were from patients with primary HCMV infection (6 of 13; 46%). None of 32 major recurrent infections showed any myocardial involvement. In conclusion, our study is the first to demonstrate that myocardial HCMV involvement preferentially occurs in primary infection and HCMV endothelial localization can be free from inflammatory reaction, whereas HCMV myocyte localization leads to necrotizing myocarditis. Polymerase chain reaction has a higher diagnostic sensitivity than in situ hybridization. However, polymerase chain reaction findings of HCMV DNA on otherwise negative endomyocardial biopsy specimens remains of questionable significance because polymerase chain reaction-positive biopsy samples do not necessarily indicate tissue infection. It is impossible to determine whether amplified sequences derive from circulating leukocytes or from tissue cells.

Antigens, Viral↗
PubMed1991

Coronary atherosclerotic plaques with and without thrombus in ischemic heart syndromes: a morphologic, immunohistochemical, and biochemical study.

We investigated incidence, severity, and distribution of coronary atherosclerosis, acute thrombosis, and plaque fissuring in ischemic heart disease (both unstable-acute syndromes and chronic ischemia) and in nonischemic controls. We also studied the structural, immunohistochemical, and biochemical profile of plaques, with and without thrombus, including morphometry, immunophenotyping of inflammatory infiltrates, cytokine presence, and ultrastructural features. Critical coronary stenosis was almost the rule in both acute and chronic ischemic series (greater than 90%) whereas it reached 50% in control subjects. Thrombosis was principally characteristic of unstable-acute ischemic syndromes (unstable angina, 32%; acute myocardial infarction, 52%; cardiac sudden death, 26%) but was also found in chronic ischemia (stable angina, 12%; ischemic cardiomyopathy, 14%) and in control subjects (4%). Plaque fissuring without thrombus occurred in low percentages in lipid-rich, severe eccentric plaques in most series. Major differences were found between pultaceous-rich versus fibrous plaques rather than between plaques with or without thrombus. Pultaceous-rich plaques were frequent in sites of critical stenosis, thrombosis, and ulceration. Inflammatory infiltrates, i.e., T cells, macrophages, and a few beta cells, mostly occurred in lipid-rich, plaques unrelated to thrombus. In adventitia, infiltrates were a common finding unrelated to any syndrome. Necrotizing cytokines such as alpha-TNF were immunohistochemically detected in macrophages, smooth muscle, and intimal cells and detected by immunoblotting in 67% of pultaceous-rich plaques, either with or without thrombus. Immune response mediators such as IL-2 were also expressed in analogous plaques but in a minor percentage (50%-40%). Media were extensively damaged in severely diseased vessels with and without thrombus. Ultrastructural study showed that the fibrous cap was either highly cellular or densely fibrillar. Intimal injury with collagen exposure was often associated with platelet adhesion, whereas foamy cell exposure was not. In conclusion, investigated parameters were essentially similar in plaques, both with and without thrombus, whereas major differences were found between pultaceous-rich and fibrous plaques. Since platelets adhere to exposed collagen and not to foam cells, the type of exposed substrates could play a major role in thrombosis.

Adult↗
PubMed1991

Expression of tumor necrosis factor in human acute cardiac rejection. An immunohistochemical and immunoblotting study.

The authors performed an immunohistochemical study on expression of tumor necrosis factor alpha (TNF alpha) in endomyocardial biopsies from human cardiac allografts. TNF alpha immunoreactivity was found in 45% biopsies with mild acute rejection, in 83% biopsies with focal moderate rejection, in 80% biopsies with diffuse moderate rejection. Biopsies with absent rejection did not show immunoreactive cells. In mild rejection, positive cells were few and scanty monocytes and macrophages (MAC-387 and LN5 positive cells) and T lymphocytes (UCHL-1/CD45 RO positive cells) (up to 20% of all infiltrating cells). Expression of major histocompatibility complex (MHC) class II antigens on infiltrating and endothelial cells occurred earlier and independent of TNF alpha reactivity. Number of immunoreactive cells increased in moderate rejection (up to 50%). Immunoreactivity was also present in nonpigmented macrophages in part of the biopsies with resolving rejection (45%). The authors conclude that TNF alpha is expressed in acute cardiac rejection by immunologically activated inflammatory cells. Immunoreactive cells increase in number with increasing severity of the reaction.

Biopsy↗
PubMedDate not supplied

Local impairment of immunoreactivity in HIV-infected women with HPV-related squamous intraepithelial lesions of the cervix.

AIMS AND BACKGROUND: The aim of this study was to compare the local immune response in two groups of patients with high-grade cervical intraepithelial squamous lesions (SIL): one with HIV infection and the other with HPV infection alone. MATERIALS AND METHODS: 16 conization specimens (8 from HIV-infected and 8 from non-HIV-infected patients) of HPV-related, high-grade SIL were selected. The specimens from non-HIV patients were considered as controls. The total number of Langerhans cells, CD4 and CD8 cells present in 10 field areas (3.120 mm2) was recorded in each case. In HIV patients CD4 and CD8 peripheral counts were performed immediately before surgery. RESULTS: The CD4/CD8 ratio never exceeded 0.71, whereas the lowest ratio in controls was 0.81: this difference was statistically significant (P = 0.0009). The mean number of Langerhans cells was markedly reduced in the high-grade SILs in the HIV patients in comparison with controls (P = 0.001). The number of CD4 cells and the CD4/CD8 ratio correlated with the peripheral CD4 count (P = 0.001 and 0.02). CONCLUSIONS: In our study a marked local impairment of cervical immunoreactivity was observed, which may play a major role in the progression of these lesions in HIV-infected women.

Adult↗