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Biomedical subjects

M De Meo

Publications and source records attributed to M De Meo.

At least 19 recordsLinked to original sources
PubMed2006

Ten cases of feline mesothelioma: an immunohistochemical and ultrastructural study.

In the cat only 10 cases of mesothelioma, mainly of the peritoneum, have been previously reported. This paper describes a further 10 cases, eight pleural and two peritoneal, in males and females aged 1-17 years. Histologically, five tumours were epithelial, three fibrosarcomatous and two biphasic. Immunohistochemical markers used in human pathology for the identification of mesotheliomas include vimentin, cytokeratin (CK) AE1/AE3, HBME-1, CK 5/6, calretinin, thrombomodulin, carcinoembryonic antigen (CEA), CD15, E-cadherin and desmin. All 10 feline mesotheliomas were positive for vimentin and CK AE1/AE3, six were positive for HBME-1, two for CK5/6, three for CEA and four for E-cadherin. All were negative for desmin and calretinin. Antibodies to thrombomodulin and CD15 failed to cross-react with feline tissues. Electron microscopy, performed in four cases, revealed microvillar structures, desmosomes and intracytoplasmic lumina, confirming its value as a diagnostic tool. The study showed that mesothelial marker antibodies commonly used in human patients can be used for the diagnosis of feline mesothelioma, preferably as a panel of antibodies rather than only one.

Animals↗
PubMed2003

Urine mutagenicity and lymphocyte DNA damage in fruit growers occupationally exposed to the fungicide captan.

AIMS: To determine haematological parameters, urine mutagenicity (on three Salmonella typhimurium strains), and DNA damage (using the comet assay) in mononuclear leucocytes of farmers before and after a one-day spraying period of pear and apple trees with the fungicide captan in usual conditions. METHODS: Fruit growers were exposed to captan during the 1998 (n = 12) and/or the 2000 spraying seasons (n = 17). Biological samples were collected on the morning of the day of spraying (S1), the evening after spraying (S2), and the morning of the day after (S3). The UK Predictive Operator Exposure Model (UK-POEM) was used to quantify pesticide exposure intensity. RESULTS: No effect was observed on haematological parameters for these two spraying seasons. Proportions of mutagenic urine samples did not significantly differ between S1 and S2/S3 sampling points. In contrast with strains TA97a and YG1041 mainly sensitive to frameshift mutations, a positive trend was observed between the difference (S3-S1) of mutagenic power on strain TA102 detecting base-pair mutations and the exposure predicted value given by UK-POEM, mainly due to parameters related to protective clothing. No significant variations in DNA damage levels were observed between S1 and S3, nor were correlations observed with parameters of pesticide exposure. CONCLUSIONS: A one-day spraying period with captan and other pesticides does not significantly induce DNA damages in mononuclear leucocytes. In contrast, an inefficient protective clothing could correlate with an increase in urine mutagenicity as assessed by the TA102 tester strain.

Adult↗
PubMed2001

Evaluation of the mutagenic and genotoxic activities of anti-hepatitis B analogs of beta-L-adenosine by the Ames test and the Comet assay.

beta-L-2'-deoxyadenosine (beta-L-dA), beta-L-2',3'-dideoxyadenosine (beta-L-ddA) and its two bis (S-acyl-2-thioethyl; SATE) phosphotriester derivatives, beta-L-2',3'-dideoxyadenosine-5'-monophosphate-bis(MeSATE) and beta-L-2',3'-dideoxyadenosine-5'-monophosphate-bis(tButylSATE) have been previously shown to exhibit potent and selective anti-hepatitis B activity in vitro. None of the four compounds was mutagenic up to 100 microg in the Ames test (microtechnique) using Salmonella typhimurium strains TA 97a, TA 98, TA 100 and TA 102, with and without metabolic activation. In addition, the genotoxicity of beta-LdA and the three other compounds was evaluated in human lymphocytes using the Comet assay, at doses up to 5 microg with or without the addition of a microsomal S9 fraction. None of the four compounds induced DNA strand breakage with and without metabolic activation. In summary, the data clearly demonstrate that the purine nucleoside beta-L-dA, beta-L-ddA and the two prodrugs, beta-L-ddAMP-bis(MeSATE) and beta-L-ddAMP-bis(tButylSATE) are not mutagenic in the Ames test and do not induce DNA damage in human lymphocytes, as assessed by the Comet assay.

Antiviral Agents↗
PubMed1998

Effects of tobacco smoke on the gene expression of the Cyp1a, Cyp2b, Cyp2e, and Cyp3a subfamilies in mouse liver and lung: relation to single strand breaks of DNA.

Cigarette smoking is a worldwide health problem and is the greatest risk factor for lung cancer. By activating procarcinogens, hepatic and extrahepatic cytochromes P450 can participate in lung carcinogenesis. Tobacco smoke contains numerous cytochrome P450 inducers, substrates, and inhibitors. In the present study we investigated, in male NMRI mice, the effects of cigarette smoke on hepatic and pulmonary cytochrome P450 expression and their possible role in the induction of DNA lesions such as DNA single strand breaks (SSB). Hepatic and pulmonary mouse cytochrome P450 isozymes involved in carcinogenesis (Cyp1a, 2b, 2e, 3a) were differently induced by cigarette smoke. Cyp2e1 mRNA was dramatically enhanced (12.7-fold increase) while Cyp2b10 mRNA remained unchanged and Cyp1a1 was decreased or not detected. Cyp3a protein and mRNA were not detected in lung, suggesting that this isozyme is not expressed in mouse pulmonary tissue. The SSB of DNA increased in lung and liver treated mice. In contrast no modification was observed in lymphocytes that barely expressed cytochromes P450. Cimetidine and propylene glycol reduced SSB of DNA induced by smoking in liver and lung cells. The inhibition (-70%) observed in lung following treatment by propylene glycol, a CYP2E1 inhibitor, suggested that this isozyme is at least in part involved in pulmonary DNA damage induced by tobacco smoke. The high concentration of CYP2E1 function and regulation in mammals suggests that this protein could be involved in pulmonary carcinogenesis in human smokers.

Animals↗
PubMed1997

[Pre-surgical medical therapy of hyperthyroidism].

The Authors analyze the use and the efficacy of antithyroidal drugs administered to the patients affected by hyperthyroidism, that must undergo thyroidectomy. The aim is that the patients arrive to the operation in euthyroidism: this is very important to avoid the complications that can occur during or just after the thyroidectomy. They believe that till today the most effective treatment of hyperthyroidism before thyroidectomy is based on the use of thyonamide and iodine. In case of intolerance to these drugs or if it is necessary an emergency thyroidectomy or in case of a low compliance of the patient, there is the possibility to use different therapeutic approaches with beta-blockers or betametasone plus iopanoic acid and propranolol administered together for a few days. As concerning the possible complications that can occur during or after the thyroidectomy, the Authors analyze in particular the thyrotoxicosis and the "hungry bone" syndrome.

Antithyroid Agents↗
PubMed1997

[Hashimoto's thyroiditis. A rare case of familial hereditary transmission].

Authors describe an uncommon case of inheritance of Hashimoto's thyroiditis that affected all the members of a family throughout three generations. Authors analyze recent advances about etiopathogenesis of this disease. In a recent paper was demonstrated that antithyroid peroxidase antibodies (anti-TPO) that have a cytotoxic activity are inherited in a dominant autosomic pattern. However only some epitopes of the antigen thyroid peroxidase predispose to the development of this disease. The peculiarity of this paper is that all the members of this family not only have elevated levels of anti-TPO, but are also all affected by disease. The study on the histocompatibility of antigens did not demonstrate significant date. Authors assert that in the pathogenesis of this disease, genetic factors have a relevant role, also if they are not well known yet. The involvement of environmental factors in this case seems to be unlikely: in fact not all the members of this family were born and lived in the same geographic area.

Adolescent↗
PubMed1996

High inducibility of mouse renal CYP2E1 gene by tobacco smoke and its possible effect on DNA single strand breaks.

Several studies have shown in humans an association between renal carcinoma and cigarette smoking. Cigarette smoke contains numerous cytochrome P450 inducers and substrates. In the present study we investigated the effect of cigarette smoke on the regulation of murine cytochrome P450 expression in kidney and its possible role in the induction of single strand breaks in DNA. Results demonstrated that CYP2E1 (activity, protein, and MRNA) was induced by tobacco smoke (2.1, 5.6 and 20.8, respectively). We did not detect any CYP1A, CYP2B, and CYP3A using Western blot and RT-PCR experiments. We have analyzed the renal single strand breaks of DNA in control and treated mice. The results indicated an increase of single strand breaks of DNA in kidney from treated mice which paralleled the high inducibility of the CYP2E1. No significant difference was observed between lymphocytes (which expressed very low or undetectable cytochrome P450 levels) of control and treated mice.

Animals↗
PubMed1996

[Alteration of luteinizing hormone pulsatility in patients with arterial hypertension].

The pattern of luteinizing hormone (LH) secretion in men with mild and moderate hypertension was studied. LH pulsatility was evaluated for eight hours in 14 male patients, who were subdivided into two groups: group A, consisting of 8 patients, whose systolic blood pressure ranged between 180-160 mmHg and the diastolic between 104-95 mmHg; group B, 6 patients whose systolic blood pressure ranged between 220 and 180 mmHg and the diastolic between 115-105 mmHg. Seven healthy adult males were evaluated as a control. The major changes of LH pulsatility in group A included an increased peak width (p < 0.05), increased peak amplitude (p < 0.001) and increased peak area (p < 0.001). In group B the changes followed the same pattern as in group A, but were more pronounced. The number of LH peaks was reduced (p < 0.01), the peak width was increased (p < 0.05), and both peak amplitude and peak area were increased as compared to the control group (p < 0.001). Our study demonstrates that the pattern of LH pulsatility is altered in essential hypertension and the main feature is represented by the prolonged duration of LH peaks and their greater amplitude. The altered pattern of LH secretion is likely to reflect a primary hypothalamic derangement with the gonadotropin releasing hormone (Gn-RH) secreting neurons remaining synchronized for longer times and secreting larger Gn-RH masses than in normal subjects.

Adult↗
PubMed1994

Hypomethylation and hypoexpression of human CYP2E1 gene in lung tumors.

We have demonstrated the presence of CYP2E1 protein in a catalytically active form in lung tumors, differences being observed between the tumors and normal tissues from the same patients. Indeed, a higher microsomal CYP2E1 N-nitrosodimethylamine (NDMA) demethylase activity was present in normal tissues compared to tumors and was accompanied by corresponding change in CYP2E1 protein concentration, as shown by Western blot analysis. The catalytic activity among tumors differed from that among normal tissues with statistical significance of p < 0.01. CYP2E1 mRNA was present in lung tumors and less expressed compared to normal tissues from the same individuals. In order to understand the regulation of CYP2E1 gene expression, we studied the methylation status of the CYP2E1 gene in human lung tumors and normal tissues from the same patients and observed that a hypomethylation was associated with a hypoexpression of the CYP2E1 gene in lung tumors.

Base Sequence↗