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N Rizzo

Publications and source records attributed to N Rizzo.

At least 55 records · Page 3Linked to original sources
PubMed1994

The predictive value of cytogenetic diagnosis after CVS based on 4860 cases with both direct and culture methods.

Cytogenetic analysis was performed in 4860 chorionic villus samples by means of both direct preparation and long-term culture. The results of the analysis were compared with a classification including all theoretical types of combinations between the chromosomal constitution of the cytotrophoblast, extraembryonal mesoderm, and fetus, with the aim of evaluating the cytogenetic variability along the trophoblast-embryo axis. Eighteen of 29 possible combinations were found demonstrating a considerable heterogeneity. A mosaic conceptus was found in 1.5 per cent of cases, with generalized mosaicisms and confined mosaicisms in 0.2 and 1.3 per cent, respectively. Cytogenetic variability along the trophoblast-embryo axis was found in 1.42 per cent of cases. Results possibly leading to diagnostic errors (false-positive and false-negative results) were found in only 1.38 per cent. False-positive results of direct preparation were the most commonly observed discrepancy (0.8 per cent), while the incidence of false-positive results of the culture method and of both methods was 0.31 and 0.16 per cent respectively. The incidence of false-negative results was 0.1 per cent, with false-negative results of direct preparation 0.08 per cent and false-negative results of both methods 0.02 per cent. False-negative results of the culture method were not found. Our data confirm the high diagnostic accuracy of chorionic villus sampling and the utility of the combined use of the two methods in minimizing diagnostic errors and in reducing the need for follow-up amniocentesis.

Chorionic Villi Sampling↗
PubMed1993

Biometry of early pregnancy with transvaginal sonography.

A prospective cross-sectional study was performed in 248 pregnant women between 5 and 12 weeks' menstrual age with transvaginal sonography to establish biometric charts of the gestational sac, embryonic crown-rump length and biparietal diameter, amniotic sac and yolk sac to be used for assessment of gestational age and prediction of pregnancy failure. Polynomial regression analysis was applied and demonstrated a statistically significant positive correlation that could be described in all cases as a quadratic function, between gestational age and all the measurements with the exclusion of the yolk sac. Centile charts of both growth models and dating models were tabulated. The interrelationship between different measurements, including the gestational sac, crown-rump length, biparietal diameter and amniotic sac was also evaluated to produce age-independent charts. The dating model of the crown-rump length was found to have mean values similar to those described in transabdominal studies. The 95% reference interval was, however, 8.4 days, which was not lower than those reported in most transabdominal studies. It was concluded that transvaginal sonography was more able than the abdominal route to allow measurement of the crown-rump length in very early gestation, but did not yield a greater accuracy in predicting gestational age.

Journal Article↗
PubMed1992

Isolation of Leishmania braziliensis from Lutzomyia ovallesi (Diptera:Psychodidae) in Guatemala.

Leishmania braziliensis is endemic in Guatemala and Belize in Central America. To help identify the vector(s) of this parasite in Guatemala, phlebotomine sand flies that were aspirated from the clothing of collectors at Tikal National Park in the Department of the Peten were examined for flagellates. Lutzomyia ovallesi was found infected with flagellates that were identified as L. braziliensis by isoenzyme electrophoresis. The isoenzyme profile of this isolate matched those from humans from the same area.

Animals↗
PubMed1992

The inhibitory action of chlorogenic acid on the intestinal iron absorption in rats.

The polyphenols are part of the composition of many foods, it is known the inhibitory effect of tea and coffee through the tannins on iron intestinal absorption; the "yerba mate" (Ilex Paraguarensis) is a beverage widely used in South America, that has a high content of a polyphenol named chlorogenic acid. The present work shows the effect of this substance in nonhem iron absorption. An intestinal loop, was made in rats, to form a closed cavity in a small section of intestine tieing it from the pilorous to a distance of six cm. In this closed cavity a solution of 59Fe was injected with different doses of chlorogenic acid; it was living 20, 40 and 120 minutes into the loop, and after this different times, the blood, spleen, liver, femur and intestine were removed to measure the 59Fe uptake to be compared with the control group. The results gave an intense inhibitory effect on the intestinal iron absorption with doses of 0.58 and 1.7 mM per rat of chlorogenic acid at the different times studied.

Animals↗
PubMed1991

Vectors of Leishmania braziliensis in the Petén, Guatemala.

During a 1-year study, 13 species of sand fly were collected in bite-landing collections on human attractants in Tikal, Guatemala. Using isoenzyme analysis, Leishmania braziliensis was identified among isolates from Lutzomyia ovallesi, Lu. panamensis, and Lu. ylephiletor. Lutzomyia ovallesi, Lu. shannoni, and Lu. cruciata were found with flagellates whose isoenzyme patterns matched unidentified flagellates isolated from a patient with mucosal lesions.

Animals↗
PubMed1990

Prenatal karyotyping in malformed fetuses.

Experience with prenatal karyotyping of 237 fetuses with sonographic evidence of malformation is reported. Abnormal karyotype was found in 40 cases (16.8 per cent): chromosomal aberrations were found in 19 of the 178 fetuses with an isolated structural anomaly (10.6 per cent) and in 21 of the 59 fetuses with multiple malformations (35.6 per cent). Detailed cytogenetic and morphological information concerning fetuses affected by omphalocele, duodenal atresia, hydrocephalus, multicystic kidney, unilateral hydronephrosis and cystic hygroma is reported. The need for a very careful ultrasound evaluation of fetal anatomy in these pregnancies is stressed, as the risk of a chromosomal anomaly depends mainly on the existence of more than one ultrasonically diagnosed structural defect.

Chromosome Aberrations↗
PubMed1990

Diagnosis and significance of cystic hygroma in the first trimester.

Thirty cases of cervical cystic hygroma were diagnosed in the first trimester of pregnancy. Karyotype analysis was available in 29 (97 per cent). Fifteen (52 per cent) had a chromosomal abnormality. The ultrasound appearance was described as posterior cervical, lateral cervical, or cervical hygroma with hydrops. Of the 14 euploid embryos, six were electively aborted, two are undelivered, and six have been delivered as phenotypically normal infants. In cases in which the chromosomes were normal and the pregnancy continued, all lesions resolved by 18 weeks.

Aneuploidy↗
PubMed1989

Prenatal diagnosis and management of fetal ovarian cysts.

Congenital ovarian cysts are a pathological condition which can be diagnosed in utero by ultrasound. We report 14 consecutive diagnoses of fetal ovarian cysts, obtained in the second and third trimesters of pregnancy. Congenital ovarian cysts have almost invariably a good prognosis, and no change in the standard obstetrical management is required. However, the evolution of the disease in utero is extremely variable. The cyst may increase in size, decrease or even disappear, or undergo complications such as torsion and rupture, which may carry some risks to the fetus. When a fetal ovarian cyst is detected, serial ultrasound examinations should be performed. If one of the above complications is suspected, the option of prompt caesarean section should be considered.

Cesarean Section↗
PubMed1989

The clinical significance of prenatally diagnosed choroid plexus cysts.

The choroid plexus cyst is one of many malformations of the central nervous system that can be detected in utero by ultrasonography. Choroid plexus cysts occur in 2.3% of fetuses. Because previous reports have shown an association between choroid plexus cysts and chromosomal anomalies, we analyzed 82 prenatally diagnosed cases, 65 of whom had chromosome analysis performed. Of the group, 6.2% had chromosomal anomalies of the trisomy 18 type. The remaining 17 cases were clinically normal at birth. These cases of trisomy 18 were also associated with multiple structural anomalies. Therefore, we suggest that after the diagnosis of choroid plexus cysts is made, a complete ultrasonographic survey of the fetal anatomy be performed. Fetal karyotype determination may be offered to patients, especially in the presence of structural anomalies.

Abnormalities, Multiple↗
PubMed1988

Transabdominal chorionic villus sampling: analysis of 350 consecutive cases.

We report a series of 350 patients submitted to transabdominal chorionic villus sampling (CVS). A technique using two ultrasound-guided needles and a suction pump was used. In most cases, the procedure was performed between 9 and 13 weeks. Twenty-one pregnancies were selectively terminated; nine spontaneous abortions followed the procedure and one fetal loss after 28 weeks was recorded; 153 pregnancies are in progress and 169 delivered fetuses are alive and well. Transabdominal biopsy is a feasible and effective technique for CVS.

Abdominal Muscles↗
PubMed1987

Prenatal diagnosis and obstetrical management of multicystic dysplastic kidney disease.

Multicystic dysplastic kidney disease (MDKD) is one of the most common congenital renal anomalies. We report 16 consecutive cases of MDKD recognized in the antenatal period by sonography. Diagnosis is usually easy as MDKD has in the vast majority of cases a striking ultrasound appearance including enlargement of the kidney and multiple renal cysts. However, differentiation from obstructive uropathy may be difficult, and we made a total of five erroneous diagnoses. Unilateral MDKD has almost invariably a good prognosis. However, severe life-threatening associated anomalies were found in six cases. Therefore, a detailed survey of fetal anatomy and determination of karyotype are strongly recommended.

Diagnostic Errors↗
PubMed1987

Criteria for the prenatal diagnosis of holoprosencephaly.

Holoprosencephaly is a congenital anomaly of the central nervous system whose prenatal sonographic appearance may to similar to that of ventriculomegaly. A clear differential diagnosis is extremely important because the two conditions have different prognoses and therefore require different obstetric management. Eight cases of prenatally recognized holoprosencephaly are analyzed and criteria for a specific diagnosis proposed. The specificity and limitations of ultrasound findings, such as identification of a holoventricle, presence of a dorsal sac, and facial anomalies are discussed.

Brain↗
PubMed1987

Intrinsic intrathoracic malformations of the fetus: sonographic detection and clinical presentation.

Intrinsic intrathoracic malformations are a rare group of congenital anomalies associated with high fetal and neonatal mortality rates. The antenatal sonographic appearance and the adequacy of diagnosis in 15 affected fetuses were evaluated. An accurate prenatal diagnosis was made in 12 cases; the precise nature of the intrathoracic defect was incorrectly categorized in two fetuses, and the defect was missed entirely in one affected fetus. Antenatal detection and characterization of intrinsic intrathoracic congenital malformations seems possible, but requires a high index of suspicion, familiarity with their sonographic appearances, and meticulous attention to detail.

Bronchogenic Cyst↗
PubMed1986

Antenatal recognition of cerebral anomalies.

Modern ultrasound equipments allow a detailed investigation of the fetal brain from a very early stage of development. Congenital anomalies arising from or involving the central nervous system can be accurately predicted. On the basis of their personal experience, which includes 48 cases, and of a review of the current literature, the authors discuss criteria for the intrauterine diagnosis and obstetrical management of intracranial anomalies such as hydrocephalus, holoprosencephaly, cephaloceles, porencephaly, hydranencephaly, and microcephaly.

Brain↗