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L De Marco

Publications and source records attributed to L De Marco.

At least 37 records · Page 2Linked to original sources
PubMed2002

[Small-cell mesothelioma of the pleura: description of a case].

A case of mesothelioma with a small cell component in a 53-year-old, non-smoker woman. The patient had a history of asbestos exposure, and presented with thoracic pain. A total body computed tomogram showed a left pleural effusion and a 7.5-cm pleural mass. Thoracoscopy revealed a diffuse nodular thickening of the left parietal pleura, and a biopsy was performed. The patient died of the disease 4 months after diagnosis. Microscopically, the pleural neoplasm was composed of three different components: 40% of the tumor showed the classic histology of a malignant epithelial mesothelioma, 40% was composed of small- to medium-sized cells with open nuclear chromatin, evident nucleoli and high mitotic activity, and 20% of the neoplasm was indistinguishable from a small cell carcinoma. Immunohistochemically, the first component was diffusely and strongly positive for cytokeratin AE1/AE3, cytokeratin CAM 5.2 and EMA, focally positive for BER-EP4, and negative for CD15, B 72.3, CEA, LCA, chromogranin, synaptophysin, TTF-1 and CD99. The cells of the second component were positive only for cytokeratin AE1/AE3 and cytokeratin CAM 5.2, and the elements of the third component were negative for all the antibodies tested. Pleural mesothelioma with a small cell component is rare. The most useful parameters to distinguish it from other small cell malignancies that may involve the pleura, particularly small cell carcinoma of pulmonary origin, are discussed.

Asbestos↗
PubMed2002

Analysis of T102C 5HT2A polymorphism in Brazilian psychiatric inpatients: relationship with suicidal behavior.

1. Central serotonergic dysfunction and genetic factors are associated with suicidal behavior in psychiatric patients. The goal of this study was to examine the association between the 5-HT2A gene polymorphism (102T/C) and suicide in a sample of Brazilian psychiatric inpatients. 2. We studied 225 subjects. Genotypic frequencies were obtained after DNA extraction and the region of 5-HT2A/T102C containing the polymorphic site amplified by the polymerase chain reaction and digested with the restriction enzyme HpaII. 3. No differences were found between patients with and without suicide attempt history. Patients with a history of severe suicide attempts also did not exhibit different genotypic frequencies when compared with patients without a suicide attempt history. 4. These results suggest that the 5HT2A gene polymorphism (102T/C) may not be involved in the genetic susceptibility to suicidal behavior.

Age Factors↗
PubMed2002

Immunolocalization of PTCH protein in odontogenic cysts and tumors.

The human patched gene (PTCH) functions in both embryologic development and tumor suppression. PTCH mutations have been found in odontogenic keratocysts. However, the expression and localization of the protein product of the gene have not been determined in odontogenic tumors and cysts. We investigated 68 odontogenic lesions by immunohistochemistry, and compared their PTCH expression with that in basal cell carcinomas. All odontogenic lesions, including two keratocysts with truncating mutations, were positive for PTCH. Different types of lesions had different amounts of staining. Lack of staining was noted in the majority of basal cell carcinomas. Taken together, these data suggest that odontogenic keratocysts arise with heterozygous mutations of the PTCH gene.

Amino Acid Sequence↗
PubMed2002

[Pulmonary metastasis of epidermoid carcinoma of the larynx: a case with an interstitial pattern of growth].

We describe a pulmonary metastasis from a laryngeal epidermoid carcinoma, characterized by an interstitial pattern of growth. The patient, a 71-year-old man, smoker, presented with a large laryngeal neoplasm and with two pulmonary masses, one located in the apex and the other in the lower lobe of the right lung. The patient underwent a total laryngectomy and a right pneumonectomy and he died from neoplastic progression 2 years after surgery. Microscopically, the laryngeal tumour was an epidermoid carcinoma and the apical pulmonary mass was an adenocarcinoma. The pulmonary neoplasm of the lower lobe, 5.5 cm across, was an epidermoid carcinoma that we interpreted to be a metastasis from the larynx. The case is peculiar because tumour cells proliferated exclusively in the interstitium. When extensive as in our case, this pattern of growth is rare and it may pose some diagnostic problems.

Aged↗
PubMed2001

Clonal composition of human adamantinomatous craniopharyngiomas and somatic mutation analyses of the patched (PTCH), Gsalpha and Gi2alpha genes.

Craniopharyngioma is the most common childhood tumor and thought to arise from embryonic remnants of Rathke's pouch. The paucity of published data on the molecular basis of these tumors prompted us to examine 22 adamantinomatous craniopharyngiomas looking for genetic abnormalities. Using the X-linked polymorphic androgen receptor gene as a tool for X-chromosome inactivating analysis, we found that a subset of craniopharyngiomas are monoclonal and therefore are probably due to acquired somatic genetic defects. Thus, we investigated these tumours for mutations within three candidate genes, Gsalpha, Gi2alpha and patched (PTCH). Using single stranded conformational polymorphism (SSCP), denaturing gradient gel electrophoresis and direct sequencing, the presence of somatic mutations in these genes could not be demonstrated in any tumor. Our data indicate that a subset of craniopharyngiomas are monoclonal and the mutations in the PTCH, Gsalpha, and Gi2alpha contribute little if any to craniopharyngioma development.

Adenoma↗
PubMed2001

Spider neurotoxins block the beta scorpion toxin-induced calcium uptake in rat brain cortical synaptosomes.

In this paper we describe the effects of the beta scorpion toxin Tityus gamma (TiTX gamma) and spider neurotoxins Tx3-3 and Tx3-4 in the (45)Ca(2+) uptake in synaptosomes. The TiTX gamma-stimulatory effect on (45)Ca(2+) uptake in synaptosomes was inhibited omega-Conotoxin MVIIC (omega-CgTX MVIIC) (0.1 microM) and omega-Agatoxin IVA (0.1 microM) by 70% and 41%, respectively. omega-CgTX MVIIC (1.0 microM) almost completely blocked the TiTX gamma-induced (45)Ca(2+) uptake in synaptosomes. Verapamil (1.0 microM) and omega-Conotoxin GVIA (0.1 microM) had no effect in the scorpion toxin-induced (45)Ca(2+) influx. The spider neurotoxins Tx3-3 and Tx3-4 inhibited the TiTX gamma-induced calcium uptake with an IC(50) of 10.0 and 30.0 nM, respectively. It is suggested that spider neurotoxins Tx3-3 and Tx3-4 blocking effect in the TiTX gamma-induced calcium uptake involves P/Q-type calcium channels.

Animals↗
PubMed2001

Screening of expression libraries using ELISA: identification of immunogenic proteins from Tityus bahiensis and Tityus serrulatus venom.

The present report describes the use of ELISA with cDNA expression libraries in the identification of immunogenic proteins. The methodology described was applied using libraries constructed with mRNA isolated from Tityus serrulatus and Tityus bahiensis venom glands. In addition we describe for the first time the sequence of a neurotoxin from Tityus bahiensis venom gland named TbTx5 whose amino acid sequencing showed 93% similarity with the Tityus bahiensis TbTx IV-5 neurotoxin. The methodology described can be used for the generation of an immunogenic bank in order to contribute to genome and proteome projects.

Amino Acid Sequence↗
PubMed2001

Glandular odontogenic cyst: absence of PTCH gene mutation.

Glandular odontogenic cyst (GOC) is a rare jawbone cyst of odontogenic origin. Human patched (PTCH) is a tumour suppressor gene that has been recently associated with signalling pathways during odontogenesis. Recently alterations of this gene were found on sporadic odontogenic keratocysts. This evidence, together with the biological behaviour similarities of both lesions, and the absence of reports on molecular analysis of GOC, led us to hypothesize that PTCH gene mutations may underlie the tumorigenesis of GOC. Therefore the aim of this study was to report one additional case of GOC and investigate the PTCH gene of the cyst. No mutations were found in the splicing and coding regions of the PTCH gene. In conclusion, the PTCH gene does not seem to be involved in GOC pathogenesis.

Aged↗
PubMed2001

Oral recurrent human herpes virus infection and bone marrow transplantation survival.

OBJECTIVE: This study was conducted to compare the survival rates of bone marrow transplantation (BMT) patients who were affected with the survival rates of those who were not affected by oral recrudescent human herpes virus-1 infection (HHV-1) after transplantation. STUDY DESIGN: Fifty-two consecutive patients who underwent BMT were included in the study. The time of death after BMT was displayed, by means of the Kaplan-Meier method, for the following parameters: age and gender of the patient, donor gender, primary disease, stem cells, conditioning regimen, platelet number after day 100, acute and chronic graft-versus-host disease, oral recurrent HHV-1 infection post-BMT, oral lichenoid lesions of graft-versus-host disease, graft-versus-host disease at the salivary glands, parenteral nutrition, and oral mucositis. The data were initially analyzed by means of the log-rank test and then included in the Cox proportional hazards model. RESULTS: The multivariate analysis demonstrated a significance of 5% for only the platelet numbers and oral recurrent HHV-1 infection. CONCLUSION: The present study provides evidence that platelet numbers below 100,000 cells/mm(3) after day 100 and oral recurrent HHV-1 infection are independent negative prognostic variables in BMT patients' 24-month survival rates.

Acute Disease↗
PubMed2001

Aggressive angiomyxoma of the spermatic cord. Two unusual cases occurring in childhood.

We report on two cases of aggressive angiomyxoma (AAM) of the spermatic cord occurring in two 13-year-old children. Clinically, the tumor simulated a mass of the spermatic cord. Histologically, it represented a poorly circumscribed, benign myxoid tumor, with a sparse population of stromal cells immunoreactive for vimentin and, focally, for smooth muscle actin. No immunostaining for desmin, S-100, p53, p21waf-1, c-Erb-B2 and estrogen-progesterone receptors was found. High proliferating cell nuclear antigen (PCNA) immunoexpression found in most of the tumor cells may explain the high risk of recurrence. AAM should be considered in the differential diagnosis of a spermatic cord mass occurring during infancy.

Adolescent↗
PubMed2001

Plasma and platelet von Willebrand factor abnormalities in patients with uremia: lack of correlation with uremic bleeding.

Chronic renal failure often is associated with abnormal bleeding that may represent an important complication of this disorder. The hemorrhagic tendency currently is attributed to altered primary hemostasis, mainly platelet dysfunction. However, von Willebrand factor (vWF) also seems to be involved, even though the nature of its abnormalities is still controversial. To gain insight into the role of vWF in determining uremic bleeding, we studied 11 patients with stable, chronic renal failure. We found a significant increase in plasma factor VIII (FVIII), vWF:antigen (Ag), and vWF:ristocetin cofactor (Rco) levels, associated with a mean decrease in platelet vWF:Ag. Plasma vWF multimer pattern was characterized by increased representation of all oligomers in all patients, but five patients also showed a slight decrease in large vWF multimers. In addition, platelet vWF multimer pattern displayed a decrease in all components, especially those with high molecular weight. Despite normal bleeding time, collagen-induced platelet aggregation was defective in almost all patients, whereas vWF collagen binding capacity was normal. The levels of glycocalicin, the circulating fragment of glycoprotein Ib-IX, the major platelet vWF receptor, were also normal. In six patients who also were studied after initiation of dialysis, collagen-induced platelet aggregation was impaired further. Moreover, plasma vWF, and especially FVIII levels, were increased additionally, in association with a normalized platelet vWF content and an improved vWF multimer pattern. The results suggest that vWF abnormalities are present in uremia. Moreover, thrombopathy caused by impaired collagen-induced platelet aggregation is constantly present and apparently not improved by dialytic treatment.

Adult↗
PubMed2001

[Extrarenal retroperitoneal angiomyolipoma: description of a case and review of the literature].

A case of retroperitoneal extrarenal angiomyolipoma is described. The patient, a 61-year-old woman, presented with a large retroperitoneal lipomatous mass. Histologically, it consisted of lipomatous tissue. Focally, there was interstitial and perivascular proliferation of bland oval and epithelioid cells with a large, eosinophilic or clear cytoplasm. Immunohistochemically, these elements were positive for smooth muscle actin and HMB-45. The literature on retroperitoneal extrarenal angiomyolipoma is briefly reviewed. It is important that the pathologist recognize this lesion, even when it is located in the retroperitoneum outside the kidney, and differentiate it from a liposarcoma.

Abdominal Pain↗
PubMed2001

[Bronchiolitis obliterans-organizing pneumonia (BOOP) containing asbestos bodies: clinico-pathological study of a case].

We describe a case of bronchiolitis obliterans-organizing pneumonia (BOOP) with asbestos bodies. A 65-year-old man, treated in the past for gastric lymphoma and with an history of asbestos exposure, presented with fever and two nodular opacities in the lower lobe of the left lung. Histologic examination revealed a BOOP pattern; in the inflammatory tissue some asbestos bodies were present. Patients exposed to asbestos may rarely present with localized inflammatory pulmonary lesions. In these cases, the possible etiopathogenetic role of asbestos needs further studies.

Aged↗
PubMed2000

On the mechanism of the spermine-exerted inhibition on alpha-thrombin-induced platelet activation.

Previous reports have shown that various amines inhibited platelet activation, but no definitive conclusions on their action mechanism were drawn. We have further investigated the action of spermine on platelet responses evoked by alpha-thrombin and other agonists. Spermine inhibited in a concentration-dependent manner (1-10 mM), and more efficiently than spermidine and putrescine, the alpha-thrombin-induced (1.5 nM) platelet activation. Spermine added at a concentration that inhibited completely aggregation only partially affected the thrombin-induced increase in cytosolic Ca(2+) concentration, protein phosphorylation, and ATP secretion. The polyamine had little effect on the morphology of resting platelets, as measured by electron microscopy, thrombin hydrolytic activity, and fibrinogen clotting capacity but decreased the thrombin binding to platelets and isolated glycocalicin. Spermine partially inhibited the aggregation elicited by ADP, vasopressin, platelet-activating factor, thrombin receptor-activating peptide, fluoroaluminate, ionomycin, and dioctanoylglycerol but did not affect the cytosolic Ca(2+) increase induced by these agonists. The polyamine bound to both glycocalicin and platelets, and it inhibited the fibrinogen binding to stimulated platelets. The amount of 14C-spermine bound to resting cells decreased in the presence of the glycoprotein GPIb-antibody LJIB1, whereas the polyamine bound to activated platelets, which was higher than that tied to resting cells, was markedly reduced by LJCP8 or decorsin, a GPIIb/IIIa antibody and antagonist-peptide, respectively. These results indicate that spermine specifically inhibits the thrombin binding to GPIb of resting platelets and the fibrinogen binding to GPIIb/IIIa (integrin alpha(IIb)beta(3)) of activated platelets.

Adenosine Triphosphate↗
PubMed2000

Molecular cloning of cDNAs encoding insecticidal neurotoxic peptides from the spider Phoneutria nigriventer.

From a Phoneutria nigriventer venom gland cDNA library several clones coding for the insect specific neurotoxin Tx4(6-1) were isolated. cDNA analysis showed that the encoded protein contained three distinct segments, comprising a signal sequence of 16 amino acids, followed by a glutamate-rich sequence of 18 amino acids and, finally, the coding region for the mature toxin. The deduced amino acid sequence for the mature polypeptide was identical to the protein sequence determined chemically. In addition, two new putative toxins called Pn4A and Pn4B were characterized and their predicted complete amino acid sequence revealed approximately 78% similarity to Tx4(6-1).

Amino Acid Sequence↗
PubMed2000

Expression of MUM1/IRF4 selectively clusters with primary effusion lymphoma among lymphomatous effusions: implications for disease histogenesis and pathogenesis.

Primary effusion lymphoma (PEL) is a peculiar B-cell lymphoma characterized by infection by human herpesvirus type-8/Kaposi sarcoma-associated herpesvirus (HHV-8/KSHV) and by preferential growth in the serous body cavities. Histogenetic studies have suggested that PEL originates from B cells at a late stage of differentiation. In this study, we have investigated PEL for the expression status of MUM1/IRF4 (multiple myeloma 1/interferon regulatory factor 4) protein, which is involved in physiological B-cell maturation and represents a histogenetic marker of late B-cell differentiation. Using multiple detection assays, all cases of PEL (n = 22) were found to express MUM1/IRF4 molecules. MUM1/IRF4 expression was a selective feature of PEL among lymphomas involving the serous body cavities as secondary lymphomatous effusions generally failed to express the protein. In reactive lymphoid tissues, MUM1/ IRF4 expression clustered with advanced stages of B-cell differentiation. Comparison of MUM1/IRF4 expression with that of other histogenetic markers defined two phenotypic variants of PEL, i.e. MUM1/IRF4+, CD138/syndecan-1+, B-cell antigen- (20 out of 22 cases) and MUM1/IRF4+, CD138/syndecan-1-, B-cell antigen+ (2 out of 22 cases), suggesting a certain degree of heterogeneity in the disease histogenesis. The implications of these data are threefold. First, MUM1/IRF4 expression corroborates the notion that PEL originates from post-germinal centre, preterminally differentiated B-cells. Second, MUM1/IRF4 may help in the differential diagnosis of PEL among other lymphomas involving the serous body cavities. Finally, MUM1/IRF4 may interact with HHV-8/KSHV-encoded interferon regulatory factors (IRFs) and thus contribute to PEL escape from interferon-mediated control of viral infection.

Antigens, Differentiation, B-Lymphocyte↗
PubMed2000

PTCH gene mutations in odontogenic keratocysts.

An odontogenic keratocyst (OKC) is a benign cystic lesion of the jaws that occurs sporadically or in association with nevoid basal cell carcinoma syndrome (NBCCS). Recently, the gene for NBCCS was cloned and shown to be the human homologue of the Drosophila segment polarity gene Patched (PTCH), a tumor suppressor gene. The PTCH gene encodes a transmembrane protein that acts in opposition to the Hedgehog signaling protein, controlling cell fates, patterning, and growth in numerous tissues, including tooth. We investigated three cases of sporadic odontogenic keratocysts and three other cases associated with NBCCS, looking for mutations of the PTCH gene. Non-radioactive single-strand conformational polymorphism and direct sequencing of PCR products revealed a deletion of 5 base pairs (bp) in exon 3 (518delAAGCG) in one sporadic cyst as well as mutations in two cysts associated with NBCCS, a nonsense (C2760A) and a missense (G3499A) alteration. This report is the first to describe a somatic mutation of PTCH in sporadic odontogenic keratocysts as well as two novel mutations in cysts associated with NBCCS, indicating a similar pathogenesis in a subset of sporadic keratocysts.

Adult↗