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G Simoni

Publications and source records attributed to G Simoni.

At least 19 recordsLinked to original sources
PubMed2005

Fetal and placental chromosomal mosaicism revealed by QF-PCR in severe IUGR pregnancies.

A number of genetic and environmental factors are taken into account as responsible for intrauterine growth restriction (IUGR); nevertheless, the relevance of genetic alteration in IUGR aetiology remains to be determined. The aim of this study was to investigate using a combined cytogenetic-molecular approach, improved by a new application of QF-PCR method, the presence of mosaic chromosomal changes in fetal/placental samples from 12 pregnancies with unexplained severe IUGR. This multiple approach allowed us to reveal and quantify subtle chromosomal mosaicisms with less than 5% of trisomic cells even in cases in which cytogenetic and FISH analyses failed to reveal them. These are three pregnancies with a mosaic trisomy for chromosomes 7, 2 and 14; the former case presented matUPD7 and was previously described in this journal (Placenta 22 (2001) 813) in association with pre- and postnatal growth restriction. It is intriguing that chromosomes 7, 2 and 14 are known or suspected to harbour imprinted genes, so that an unbalanced gene dosage in a subset of cells during embryonic development could lead to an early impairment of placental function. Our findings indicate that extensive molecular and cytogenetic studies of IUGR fetal and placental tissues are necessary to reveal at least part of the heterogeneous genetic lesions implicated in IUGR phenotypes.

Adult↗
PubMed2003

Genetic characterization of the three medicinal Echinacea species using RAPD analysis.

The three medicinal species of the Echinacea genus, E. angustifolia DC., E. pallida (Nutt.) Nutt. and E. purpurea (L.) Moench were distinguished using the RAPD (random amplified polymorphic DNA) technique. Species-specific markers were identified from amplicons obtained with four of the twenty 10-mer primers contained in the Operon RAPD kit A. In particular, one marker was identified for E. angustifolia (OPA 20, 1800 pb) and E. pallida (OPA 10, 600 pb) and three markers for E. purpurea (OPA 11 : 1250 pb; OPA 17 : 750, 1800 pb). Genetic distance analysis indicated a high degree of difference among the three species with a relative lower difference between E. angustifolia and E. pallida.

Echinacea↗
PubMed2002

[Growth rate of abdominal aortic aneurysms. Ultrasounds study and clinical outcome].

BACKGROUND: The standard treatment for abdominal aortic aneurysms (AAA) >55 mm is actually represented by surgical repair mainly or by endovascular repair, in selected cases; conversely the debate is still open for those ranging 40-55 mm. These last and smaller aneurysms are usually followed-up by ultrasounds (US), in order to detect too fast expansions and to prevent sudden ruptures. Aim of this study is to present the results of the US follow-up of a series of asymptomatic AAAs and the correlation between expansion rate and associated risk factors. METHODS: All patients evaluated for an AAA between March 1991 and December 2000 were included and, according to the maximum diameters of the infrarenal aorta, were divided into 3 groups: A (26-29 mm), B (30-39 mm) and C (>39 mm). Groups A and B underwent US follow up at 6-month intervals, while group C underwent a complete preoperative evaluation. RESULTS: The mean follow up was 36+/-24 months for the entire series (225 AAA); the mean expansion rate was 1 mm/year for group A, <1.5 mm/year for group B for the first 5 years with a sharp increase (5 mm/year) in the following 2 years and 3 mm/year for group C up to 5 years. Among the associated risk factors, hypertension and smoking have confirmed their main role, independent from the initial diameter (p<0.01). Eight ruptures (3.8%) occurred in patients unsuitable for surgery or who refused it and in 7 cases they were lethal. The range between diagnosis and death (19-61 months) and the maximum size (38-93 mm) were absolutely unpredictable. The remaining 40 deaths were related to vascular diseases (MI and stroke 29.8%) or concurrent neoplasms (29.8%) mainly. The surgical treatment was carried out as elective repair on 45 patients (mortality rate 2.2%) and in emergency in 2 cases, both dead, with a mean interval from diagnosis to surgery of 28+/-17 months. CONCLUSIONS: Our results agree with the literature data concerning the dilatative trend and the risk factors and, according to these, elective repair in patients with AAA ranging 45-55 mm should be considered.

Aortic Aneurysm, Abdominal↗
PubMed2001

Loss of heterozygosity of the NOS3 dinucleotide repeat marker in atherosclerotic plaques of human carotid arteries.

We have investigated 28 atherosclerotic plaques of human carotid arteries with a panel of 39 microsatellite markers for the presence of LOH. The objective of this research was to verify if LOH, described in association with tumorigenic process, could be involved also in benign fibroproliferative disease. Seventy percent of samples demonstrated allelic imbalance: 50% of cases showed LOH at a minimum of one locus, 3.5% at a minimum of two loci and 14.3% at three or more loci. The percentages of LOH ranged between 3.8 and 14.3% and the highest involved polymorphic marker is the NOS3 internal dinucleotide repeat. Our results indicate that, like tumorigenesis, the atherogenic process could also involve LOH mechanism. Furthermore, the finding regarding the NOS3 internal polymorphism suggests a possible role of the gene as cofactor in formation of the atheromas.

Alleles↗
PubMed2001

External carotid artery shunting during carotid endarterectomy: an alternative for cerebral protection?

OBJECTIVES: to assess the application of external carotid artery (ECA) shunting in cerebral protection during carotid endarterectomy (CEA). DESIGN: prospective study. MATERIALS AND METHODS: the study comprised 137 consecutive patients who underwent CEA under locoregional anaesthesia. Transcranial Doppler was used to monitor the mean velocity of the middle cerebral artery (mv-MCA): (1) before carotid clamping; (2) after clamping both the common and external carotid arteries; (3) after clamping the internal carotid artery alone ("ECA test"). The decision to shunt was based on the occurrence of neurological deficit during carotid clamping. If the ECA test revealed mv-MCA approaching the pre-clamping values ECA shunting was used, whereas the remaining patients in need of a shunt had a standard internal carotid artery (ICA) shunt. RESULTS: shunting was necessary in 12/137 cases (9%). The ECA test indicated that in four cases - 3% of the whole series or 33% of the shunted cases. In these four patients ECA shunting reversed the neurological deficit, and CEA was successfully performed without any complications. CONCLUSIONS: ECA shunting could be considered as an alternative to standard ICA shunting. Suitable cases can be identified on the basis of the ECA test.

Aged↗
PubMed2001

Post-zygotic origin of complete maternal chromosome 7 isodisomy and consequent loss of placental PEG1/MEST expression.

Maternal UPD of chromosome 7 is associated with pre- and postnatal growth retardation (IUGR, PNGR) and Silver-Russell syndrome (SRS [MIM 180860]). We report a case of IUGR in a newborn with SRS stigmata. Using combined haplotyping and cytogenetic-FISH studies we characterized the lymphocytes, umbilical cord and four placental cotyledons. The results are consistent with complete maternal isodisomy 7 and trisomy 7 mosaicism of post-zygotic origin. The trisomic cell line was prevalent in trophoblast cells from two placental cotyledons. Trisomy 7 of post-zygotic origin is a frequent finding, but maternal isodisomy 7, due to trisomic rescue has never been reported. PEG1/MEST expression was evaluated on placenta cDNA and a specific transcript was revealed only in the cotyledons with a high percentage of trisomic cells and the presence of the paternal chromosome 7 contribution, but not in the placental biopsies with maternal isodisomy 7. The histological features of the four placental fragments revealed that isodisomy 7 correlates with a pattern of cotyledonary hyper-ramification due to an increase of the branching angiogenesis, which could be the result of a defect of angiogenesis caused by the absence of PEG1 product. The severe hypo-ramification of the two cotyledons, showing trisomy 7 mosaicism, may be due to the triplicate dosage of genes on chromosome 7. The delayed fetal growth could be the phenotypic effect of the imbalance between imprinted and non-imprinted genes on chromosome 7 in the fetus or the result of abnormal placental function during pregnancy.

Adult↗
PubMed2000

Losses of heterozygosity in oral and oropharyngeal epithelial carcinomas.

We analyzed 25 oral and oropharyngeal epithelial carcinomas for loss of heterozygosity (LOH) and microsatellite instability by using 55 oligonucleotide repeat markers located in 45 chromosomal regions. The aim was to identify which chromosomal regions and tumor-suppressor genes (TSGs) are preferentially lost in these tumors and to relate LOH at specific loci to clinicopathologic data. The analysis was performed on tumor tissue and on a corresponding normal tissue (blood lymphocytes) with the use of the polymerase chain reaction technique followed by microsatellite allele separation with denaturing gel electrophoresis. Thirty-two of 45 chromosomal regions demonstrated a significant (>/=20%) incidence of LOH. An allelic loss of >/=50% was found in 9p21 (77.8%), 8p22-23 (70%), 3p12 (61.5%), 1p36.1 and 12q22 (60%), 3q28 (57.1%), 5q23.3 (54.5%), 3p25-26, 3p24, and 7q35 (50%). We did not find any microsatellite instability. Our results suggest that in addition to a group of TSGs, pleiotropic for several tumor types, other suppressor genes are specifically involved in oral and oropharyngeal carcinogenesis.

Adult↗
PubMed2000

Losses of heterozygosity in endometrial adenocarcinomas: positive correlations with histopathological parameters.

We analyzed 37 samples of endometrial adenocarcinoma for loss of heterozygosity (LOH) by using a panel of 44 microsatellites located in 29 chromosomal regions. The aim of our study was to investigate the existence of a possible preferential involvement of some tumor suppressor genes in endometrial carcinogenesis. The analysis was performed on tumoral tissue and on a corresponding normal tissue by the use of polymerase chain reaction (PCR) and the comparison of the amplified alleles. We observed significative LOH (>20%) in the chromosomal regions of 2q14 (33.33%), 7q35 (24.00%), 10q22.1 (37. 50%), 11q13-q14 (44.12%), 15q26 (40.63%), 17p13 (25.71%), and 17q21. 3 (37.04%). We defined a 1-cM minimal common deletion in 11q13-q14 between D11S911 and D11S937 markers. A statistical analysis revealed a positive correlation between LOH of 11q13-q14 and clinicopathological data.

Adenocarcinoma↗
PubMed2000

Blood fetal microchimerism in primary biliary cirrhosis.

The autoimmune nature of primary biliary cirrhosis (PBC) is well established. We tested the hypothesis that fetal microchimerism indicated by the persistence of circulating fetal cells in women years after pregnancy might contribute to the aetiopathogenesis of PBC through a graft-versus-host-like response. We extracted DNA from the peripheral blood cells of 36 women carefully selected from 173 consecutive PBC patients, who were matched with 36 healthy women by age, age of last son, and number of children. Both patients and controls had to have male offspring, and no history of miscarriages or blood transfusions; they could not be twins. We tested all of the samples for the presence of two specific Y-chromosome sequences (SY154 and SRY) by amplifying DNA in a nested polymerase chain reaction. Y-chromosome-specific DNA was detected in the peripheral blood cell DNA of 13 (36%) of the 36 women with PBC and in 11 (31%) of the 36 healthy controls. The two groups of PBC patients with and without male DNA sequences were similar in terms of their clinical, biochemical, and serological features. Y-chromosome sequences were found in three of the four PBC women with associated systemic sclerosis. All of the 24 Y-positive samples contained SY154 sequences, but only three PBC patients and six controls showed the presence of both SY154 and SRY sequences. This discrepancy may suggest that not only fetal cells but also fragments of fetal DNA are present in maternal circulation. Overall, our data do not support the hypothesis that fetal microchimerism plays a significant role in the onset or progression of PBC.

Adult↗
PubMed1999

[Calf muscle venous thrombosis and pulmonary embolism].

INTRODUCTION: The clinical significance of calf muscle venous thrombosis (CMVT) still remains a matter of debate. Detected by ultrasonography, they are overlooked by venography. This prompted us to evaluate the frequency of such localizations and their association to pulmonary embolism (PE). METHODS: Retrospective review of our database over a three-year period. All patients with an isolated CMVT were included. RESULTS: Isolated CMVT were detected in 106 patients (mean age 68.6 years; 65% women), that is 12.5% of all venous thromboses diagnosed in the vascular sonography unit over the study period Sixteen associated PE were detected (15%). CONCLUSIONS: Association of CMVT and PE is not infrequent. Whether or not such thromboses have the potential to extend into deep veins and/or to migrate into pulmonary circulation requires further studies.

Aged↗
PubMed1998

Trisomic zygote rescue revealed by DNA polymorphism analysis in confined placental mosaicism.

Uniparental disomy can be caused by different genetic mechanisms such as gamete complementation, chromosome duplication in monosomic zygote, or post-zygotic aneuploidy correction. This last mechanism is well documented in human reproduction and is related to placental mosaicism. In the case of a trisomic zygote which has originated by paternal or maternal non-disjunction at the first or second meiotic cell division, mosaicism will result from chromosome loss and restoration of a 'normalized' diploid fetal karyotype. In order to enrich the literature with new observations on this subject, we studied by DNA polymorphism analysis ten cases of confined placental mosaicism (CPM). The finding in placental DNA of three different alleles at polymorphic loci of chromosomes 13, 16, and 20 demonstrated the trisomic status of the zygote in three cases. On the basis of these results, we believe that systematic DNA polymorphism analysis could give useful additional information to improve knowledge on aneuploidy correction in human reproduction.

Alleles↗
PubMed1998

Intrarenal arteriosclerosis and impairment of kidney function in NIDDM subjects.

It is currently under debate whether the pathogenesis of end-stage renal failure in non-insulin-dependent diabetes mellitus (NIDDM) is a consequence of microangiopathy alone. The aim of this study was to investigate intrarenal arteriosclerosis and its correlation with kidney function in NIDDM. In 36 diabetic subjects, and in 10 age- and sex-matched healthy control subjects we measured kidney volume and resistive index of the interlobar arteries by duplex Doppler ultrasonography. Clinical and metabolic parameters, renal function and vascular sequelae of the disease were also evaluated. In diabetic subjects resistive index (median 0.72, range 0.54-0.79) was higher than in control subjects (median 0.62, range 0.57-0.66) (2p < 0.002). Kidney volume and resistive index correlated with age (p < 0.004), body mass index (p < 0.001), mean blood pressure (p < 0.001), total and LDL cholesterol (p < 0.01) and creatinine clearance (p < 0.001 and < 0.01, respectively). Kidney volume also correlated with HbA1 (p < 0.01) and resistive index with uric acid (p < 0.01). Lower body macroangiopathy was associated with increased resistive index and reduced kidney volume (2p < 0.05), while upper body macroangiopathy and microangiopathy were not. Our data suggest that macroangiopathy rather than microangiopathy is mainly responsible for impairment of kidney function in NIDDM. The resistive index of interlobar arteries seems to be a reliable marker of intrarenal arteriosclerosis and can be used as a non-invasive, easily available parameter of its evolution.

Arteriosclerosis↗
PubMed1998

Differential device performances for hepatic arterial chemotherapy: a technical report on totally implantable pumps and ports for both continuous and bolus infusion.

Performances of totally implantable infusion systems were analyzed in patients with colorectal liver metastases undergoing intra-arterial treatment. It consisted of 14-day continuous infusion of 5-fluor-2'deoxyuridine with pumps (pump14, 44 patients) or ports fed by external pumps (port14, 34 patients), or bolus infusion of cisplatin (port21, 57 patients) or epirubicin (port7, 22 patients) every 3rd week and weekly, respectively. Toxicity and disease progression were the most common causes of treatment interruption. System failure occurred in 2 pump14, 9 port14, 6 port21 and 2 port7 cases. Pocket problems were most frequent in the pump14 group (30%), whereas catheter- and infusion-related problems were mostly observed in the port14 group (109%). The devices were still functional after 12 months in 92% of pump14, 24% of port14, 65% of port21 and in 78% of port7 patients. Although implantable ports allow adequate infusion periods, in most cases they appear especially suitable for bolus infusions.

Adult↗
PubMed1997

Cytogenetic abnormalities and microsatellite instability in endometrial adenocarcinoma.

Recently various authors described a new mechanism involved in the genesis of some tumors, which is characterized by a tendency for replication mistakes and by genomic instability of microsatellite repeats. This instability can be revealed through the shift in the electrophoretic mobility of the analyzed fragments, which is due to a different number of repeat units. This phenomenon is widely documented in colorectal tumors of patients affected by hereditary nonpolyposis colorectal carcinoma (HNPCC). We performed a cytogenetic and molecular study of 23 endometrial adenocarcinomas to investigate the presence of genomic instability and to evaluate the possibility of a positive correlation with specific chromosomal changes. The study of genomic instability was performed using 23 microsatellites localized over 8 chromosomes. Genomic instability of microsatellites was observed in 3 cases over all 8 analyzed chromosomes. The tumoral stage of cases with microsatellite instability does not differ significantly from the remaining tumors. As a matter of fact several cases showing no evidence of instability were more advanced (II B, III A) than tumors with instability. In ten cases we observed trisomy of chromosome 10, in some as a sole anomaly. The 3 cases with genomic instability revealed a near-diploid karyotype and all showed the presence of a supernumerary marker derived from chromosome 1 rearrangements. A derivative chromosome 1 was revealed in 4 cases without evidence of microsatellite instability. It should be noted that the presence of many unidentified markers and the small number of tumors with instability do not allow us to give a definitive significance to this observation. Our results indicate that there is not an apparent correlation between microsatellite instability and specific chromosomal abnormalities. Moreover, we did not find any correlation between pathological characteristics of the tumor and genomic instability. Microsatellite instability appears to be a relatively rare event in endometrial carcinoma.

Adenocarcinoma↗