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Biomedical subjects

G Simoni

Publications and source records attributed to G Simoni.

At least 109 records · Page 6Linked to original sources
PubMed1986

First trimester fetal karyotyping: one thousand diagnoses.

Cytogenetic investigations for diagnostic purposes were performed on 1000 first trimester samples of chorionic villi (CVS) in two laboratories using similar techniques. Fetal karyotyping was the primary indication for CVS in 912 and maternal age was the major indication in 758 of them. The risk category "previous child/fetus with chromosome abnormality" included 74 diagnoses, while the category "chromosome abnormality in one of the parents" included 38 diagnoses. Sex determination was the primary indication for CVS in 53 pregnancies. The overall incidence of chromosomal abnormalities was 70, of which 47 were balanced and 23 unbalanced. The results are detailed for each of the risk categories and the incidence of abnormal karyotypes is given for each year of maternal age. In the maternal age of 35-37 years the incidence of unbalanced karyotypes was 2.9% and in the years 38 onwards it was 6.6%. The incidence of unbalanced karyotypes was about 4% when the sampling was made in the weeks 9 to 12 but six abnormal karyotypes were found among 39 CVS performed at the eight week of gestation. The 11 trisomies of the type not found at birth were clustered between the 8th and the 10th week of pregnancy. The technical problems encountered in this experience and the preliminary estimates of fetal loss are discussed.

Abortion, Spontaneous↗
PubMed1986

Reproductive failure and parental chromosome abnormalities.

The effect of ascertaining on estimates of the frequency of parental chromosome abnormalities in couples with a previous history of pregnancy wastage was investigated by comparing three samples which differ in the ascertainment modality but not in the cytogenetical approach. The incidence of chromosome abnormalities was higher in the sample of 441 couples selected essentially on clinical criteria (6%) than in the two samples (659 and 479 couples) selected retrospectively from the files of two cytogenetic laboratories (4.6 and 3.2%). The comparison of these results with similar data, based on large samples reported in the literature, indicated that sample size may be relevant in producing the wide ranges of variation of the frequency of chromosomal abnormalities. Using our data and those from three other samples of greater than 300 couples a reasonable estimate of the overall incidence of chromosomal abnormalities in couples with a previous history of fetal wastage is approximately 5%.

Abortion, Habitual↗
PubMed1986

Regional arterial chemotherapy of liver tumours. I. Performance comparison between a totally implantable pump and a conventional access system.

Thirty-nine patients with liver tumours have been submitted to regional arterial chemotherapy by means of either totally implantable Infusaid-400 pumps (22 c.) or implantable ports (17 c.). The latter were subsequently perfused with external pumps. There was one single major operative complication and no operative deaths. Most patients underwent continuous Fudr infusion. Access related complications occurred in both groups. Treatment was stopped for access related complications in 18.4% and 29.4% of cases out of the pump and port groups respectively. In most of those cases, however, several cycles of chemotherapy had already been performed. The Infusaid-400 pumps showed a 12-month functional duration of 57% with a 13-month median, the 10-month duration of ports being 67%. The difference was not significant. The new implantable systems give better results in comparison with traditional regional access methods, the functional performances of the port systems appearing very similar to the totally implantable pumps, with an obvious advantage for the pumps as far as quality of life is concerned.

Antineoplastic Agents↗
PubMed1985

Intrahepatic arterial flow distribution after ligation of a right replaced hepatic artery. A case report.

A basic requirement for arterial chemotherapy of liver tumors is complete catheter perfusion of the liver. In cases with atypical anatomy of the hepatic artery, it is frequently impossible to obtain this goal by means of a single catheter. In a patient with a right replaced hepatic artery, the aberrant vessel was ligated and the left hepatic artery was perfused through a catheter inserted into the gastroduodenal artery. Perfusion scans performed through the catheter 14 and 135 days after arterial ligation showed a fall in the arterial flow to the right liver (right/left ratio 0.43 and 0.60). In contrast, a nearly complete perfusion of the liver (0.91 right/left ratio) was obtained 28 days after ligation, when the perfusion scan was performed immediately after catheter infusion of 90,000,000 degradable starch microspheres (DSM: diameter = 40 m). DSM administration is supposed to increase back pressure in the lobe receiving native circulation, thus activating intrahepatic collateral flow to the ischemic lobe. As regards regional treatment of liver tumors, obvious conclusions are to be drawn.

Antineoplastic Agents↗
PubMed1985

First trimester fetal diagnosis of genetic disorders: clinical evaluation of 250 cases.

Chromosome and enzyme determinations were performed in 250 pregnancies between the 7th and the 12th week of gestation. The majority of the tests were performed for risk of chromosomal abnormalities and 75% of the women were 35 years old or more. We describe a chorionic villi sampling (CVS) technique which proved to be highly efficient, with a diagnostic success rate of 97.7%. In the light of our experience we suggest that CVS is best performed between the 9th and 10th weeks of pregnancy. The average weight of the aspirated specimen was 20 mg with a lower limit of 5 mg which proved sufficient for diagnostic purposes. No major maternal complications were encountered and the slight bleeding observed in 14% of the cases during the days following the CVS should be considered a harmless effect of the aspiration technique. The proportion of fetal losses may lie between 4 and 7%. Paediatric monitoring of the 93 infants born so far and ultrasound examination of the pregnancies still in progress at the time of writing did not reveal any negative effect of CVS. Fetal-maternal transfusion and intrauterine infection are problems which need further basic investigations.

Adult↗
PubMed1985

Redistribution of arterial blood flow in metastases-bearing livers after infusion of degradable starch microspheres.

Changes in intrahepatic arterial blood flow after intraarterial injection of degradable starch microspheres (DSM) were studied in four patients undergoing hepatic arterial chemotherapy. All four livers contained metastases, three from colorectal cancer and one from melanoma. Using a CT scanner with a dynamic program, 8 mm liver sections were studied in each patient before and after the DSM infusion (180(-6) in 3 min). Density plots were obtained from 12 tumoral and 12 parenchymal areas after 5 ml push arterial injections of nonionic contrast medium. The areas under the curves (ID) were calculated. The ID after DSM infusion was reduced by 94% in a single hyperdense colorectal metastasis and by a mean of c. 82% in ten parenchymal areas. By contrast, nine hypodense colorectal metastases showed an average ID decrease of c. 156%. The ID of two melanoma metastases was reduced after DSM (-48% and -68%), while the ID of two matched parenchymal areas showed an approximately similar degree of increase (+36% and +64%). Since ID after contrast injection can be assumed to be a function of blood volume, mutual changes of parenchymal and tumoral blood flow appear to take place in metastases-bearing liver after arterial infusion of DSM. This phenomenon may be of diagnostic and therapeutic value for intraarterial chemotherapy of liver tumors.

Antineoplastic Agents↗
PubMed1984

Diagnostic application of first trimester trophoblast sampling in 100 pregnancies.

The results of the diagnostic application of first trimester trophoblast sampling in 100 pregnancies are reported in detail. Further improvement of the method for routine, direct chromosome analysis resulted in a technique which proved to be fast, simple, and efficient. We found that short-term incubation of villi permits the application of many experimental methods, such as visualization of sister chromatid exchanges and bromodeoxyuridine (BrdU) incorporation. Fetal karyotyping was successful in each of the 96 pregnancies in which fetal material was obtained from a total of 98 fetuses. There were 42 males and 56 females, and an abnormal chromosome constitution was found in 12 cases. Two trisomic fetuses were found among the eight pregnancies at risk for Duchenne muscular dystrophy, and this indicates that fetal sexing (which is achieved with our method in two hours) should not be performed without chromosome visualization. The results indicate a risk of 8% of an abnormal fetus for mothers aged 35 years or more, while the risk of failure of sampling and of spontaneous abortion after villi sampling were 4 and 6%, respectively. Enzyme determinations were performed in three pregnancies at risk for gangliosidosis GM1, Niemann-Pick disease, and Hurler syndrome. In this last case inconsistency between the results of the assay of iduronidase on chorionic villi and amniotic fluid cells was found. This unexplained error indicates the need for extensive characterisation in chorionic villi of the series of enzymes involved in metabolic diseases.

Adult↗
PubMed1984

First trimester fetal karyotyping in twin pregnancy.

Fetal chromosome analysis in a twin pregnancy during the first trimester is described. Problems of the reliability of tissue sampling are also discussed. The authors emphasise the advantage of direct cytogenetic analysis from the tissue specimens used for enzyme determination or DNA studies.

Female↗
PubMed1983

Routine chromosome analysis on fetal blood microaliquots obtained at fetoscopy.

A routine study of the fetal karyotype was performed on samples obtained at 64 fetoscopic procedures. In 13 cases only pure amniotic fluid was available for the cultures, while in the remaining 51 cases the chromosome analysis was carried out on PHA-stimulated lymphocyte microcultures set up with any excess fetal blood above the requirements for globin-chain synthesis. Karyotype could be determined on fetal lymphocytes in 44 cases (86 per cent). All the fetuses were chromosomally normal. This experience shows that cytogenetic analysis using microaliquots of fetal blood is a relatively simple technique which should be introduced into routine prenatal diagnosis by fetoscopy.

Amniotic Fluid↗
PubMed1983

Efficient direct chromosome analyses and enzyme determinations from chorionic villi samples in the first trimester of pregnancy.

Chorionic villi were obtained by an aspiration technique which proved to be the best of four alternative procedures. We report in detail the series of experiments which led to (1) successful, rapidly growing cell cultures practically free of maternal cell contamination (the use of hormone-supplemented Chang medium greatly increased the growth rate); (2) an efficient direct method to obtain high quality metaphases from the Langhans cells of the cytotrophoblast tissue and with which the fetal karyotype is defined within a few hours of chorionic villi sampling; and (3) successful testing for the activity of eight enzymes directly from the villi samples, thus showing that this material is suitable for a rapid, direct diagnosis of the related metabolic diseases.

Catheterization↗
PubMed1983

Deficiency, transposition, and duplication of one 15q region may be alternatively associated with Prader-Willi (or a similar) syndrome. Analysis of seven cases after varying ascertainment.

Seven patients are described who have some or all of the symptoms of Prader-Willi syndrome. They were ascertained by varying criteria starting either from the clinical picture or from the identification of a chromosome abnormality involving the proximal portion of the long arm of chromosome 15. The chromosome abnormalities consisted of two balanced translocations (15;18 and 8;15), three unbalanced ones (15;18, 15;19, and 9;15), and one interstitial deletion of bands 15q11 and q12. The seventh case had an unidentified extra chromosome. These data and a review of the literature led to the conclusion that deficiency, transposition, and even duplication of the region(s) 15q11-q13 may all result in a syndrome which is identifiable with or similar to the Prader-Willi syndrome.

Adolescent↗
PubMed1983

SCE analysis in children exposed to lead emission from a smelting plant.

The frequency and location of SCE were evaluated in lymphocytes from peripheral blood cultures of 19 children living in a widely contaminated area and showing an increased absorption of lead. In the comparison between the exposed children and a control group living in an uncontaminated area, no significant differences were found in the mean values of SCE frequencies. The distributions of the SCE between chromosomes were proportional to chromosome length in both groups.

Adolescent↗
PubMed1983

Determination of amylase by measurement of enzymatic activity and by enzyme immunoassay and radioimmunoassay.

Alpha-amylase content was determined by enzyme immunoassay and radioimmunoassay and enzyme activity by enzymatic test in some pig tissues and serum during ontogenetic development. Among the studied organs, the highest enzyme content and activity were found in the pancreas. In this organ, amylase ratio in fetuses, newborns and adults was 1:13:1500. The ratio of the adult amylase content in pancreas, parotid gland and kidney was 4000:5:1, respectively. Close correlation was shown between the results obtained with the immunological and enzymatic methods.

Age Factors↗
PubMed1982

Cytogenetic findings in 4952 prenatal diagnoses. An Italian collaborative study.

The development of prenatal diagnosis in Italy was made difficult by the restrictions of the old abortion law and only in recent years has a consistent number of cases been investigated. We report the experience on prenatal chromosome diagnosis of ten Italian centers participating in a collaborative study on 4952 diagnoses performed from 1972 to 1980. The main indication groups were: advanced maternal age (2882 cases), previous child with chromosome anomaly from parents with normal karyotype (847 cases), and chromosome anomaly in one parent (97 cases). The other indications for amniocentesis, including cases without a cytogenetic risk, have been assembled into a "miscellaneous" group (1126 cases). We found 125 abnormal fetal karyotypes (2.5%) of which 89 were unbalanced (1.8%). The frequencies and types of chromosome anomalies are reported in detail for each indication group and are compared with the corresponding one from the European Munich Conference. The great majority of these Italian data were not included in the Munich report.

Chromosome Aberrations↗