Radioisotope contaminations from releases of the Tomsk-Seversk nuclear facility (Siberia, Russia)

Soils have been sampled in the vicinity of the Tomsk-Seversk facility (Siberia, Russia) that allows us to measure radioactive contaminations due to atmospheric and aquatic releases. Indeed soils exhibit large inventories of man-made fission products including 137Cs (ranging from 33,000 to 68,500 Bq m(-2)) and actinides such as plutonium (i.e. 239+240Pu from 420 to 5900 Bq m(-2)) or 241Am (160-1220 Bq m(-2)). Among all sampling sites, the bank of the Romashka channel exhibits the highest radioisotope concentrations. At this site, some short half-life gamma emitters were detected as well indicating recent aquatic discharge in the channel. In comparison, soils that underwent atmospheric depositions like peat and forest soils exhibit lower activities of actinides and 137Cs. Soil activities are too high to be related solely to global fallout and thus the source of plutonium must be discharges from the Siberian Chemical Combine (SCC) plant. This is confirmed by plutonium isotopic ratios measured by ICP-MS; the low 241Pu/239Pu and 240Pu/239Pu atomic ratios with respect to global fallout ratio or civil nuclear fuel are consistent with weapons grade signatures. Up to now, the influence of Tomsk-Seversk plutonium discharges was speculated in the Ob River and its estuary. Isotopic data from the present study show that plutonium measured in SCC probably constitutes a significant source of plutonium in the aquatic environment, together with plutonium from global fallout and other contaminated sites including Tomsk, Mayak (Russia) and Semipalatinsk (Republic of Kazakhstan). It is estimated that the proportion of plutonium from SCC source can reach 45% for 239Pu and 60% for 241Pu in the sediments.     

Fluorescent in situ hybridization (FISH): A new application in the delineation of true vs. pseudomosaicism in prenatal diagnosis

Metaphase chromosomes and interphase nuclei from nine amniotic fluid cultures were studied with fluorescence in situ hybridization (FISH). The samples were initially analyzed with routine G-banding and were diagnosed as having true mosaicism (five patients) or pseudomosaicism (four patients). In our study, FISH analysis could provide additional information to distinguish pseudo– from true mosaicism by allowing interphase studies and analysis of an increased number of metaphase spreads. These results suggest a multilinear origin of ‘in situ’ colonies of cells.     

A fetal cystic neck mass associated with maternal tuberous sclerosis. Case report and literature review

Tuberous sclerosis is a single gene autosomal-dominant disorder, characterized by multiple hamartoma formation. It shows a wide variability of expression. Prenatal diagnosis by means of a DNA or biochemical marker is not yet possible. Ultrasound offers the only way to detect possible antenatal hamartoma formation, which is most commonly found in the central nervous system, the renal system, and the heart. We report a case of fetal involvement that appears unique because of the unusual location of a tumour in the neck of the fetus.     

Asymptomatic carrier of two CFTR mutations: Consequences for prenatal diagnosis?

The cystic fibrosis (CF) gene has been observed to have the highest frequency of mutations in the Caucasian population. Prenatal diagnosis can now be performed with a high degree of accuracy since the identification of most of the gene's mutations, as well as the characterization of intragenic markers. However, the observation of a distribution of clinical phenotypes increases the need to identify a mild phenotype and avoid false-negative diagnosis. By screening most of the exons of the CFTR gene, we showed that a supposed obligate carrier of CF was in fact an asymptomatic affected woman.     

Prenatal diagnostic procedure for leukocyte adhesion deficiency

Leukocyte adhesion deficiency (LAD) is a rare autosomal recessive disorder which leads to recurrent severe infections due to impaired leukocyte functions. The disorder is caused by an absence or deficiency of leukocyte cell adhesion molecules (LeuCAMs) on the leukocyte membranes. The diagnosis is established with monoclonal antibodies against the LeuCAMs. We have carried out a prenatal diagnostic procedure by means of cordocentesis in a mother who was 20 weeks pregnant and had previously given birth to a child with LAD. This previous child had the severe form of LAD with undetectable mRNA for the β chain, the common subunit of the LeuCAMs. We found that the fetal granulocytes expressed the LeuCAMs normally. At birth, the baby was physically normal and showed no signs of impaired leukocyte functions.     

Prenatal diagnosis of harlequin ichthyosis by fetal skin biopsy; Report of two cases

Two cases of harlequin ichthyosis were successfully diagnosed prenatally by fetal skin biopsy. The aborted fetuses were later confirmed to be afflicted with this very unusual skin disease. Both families had a previous history of harlequin ichthyosis. In performing the biopsy, it was found that amniotic fluid cytology can also be very helpful in the diagnosis of this kind of severe ichthyosis. With regard to these families, the disease may have been transmitted in an autosomal dominant fashion, and not in a recessive manner as is commonly believed.     

Antenatal thrombocytopenia in three patients with TAR (thrombocytopenia with absent radii) syndrome

Three fetuses with TAR (thrombocytopenia with absent radii) or TAR variant syndrome were found to be thrombocytopenic during the third trimester of the pregnancy. These findings indicate that fetal blood sampling, besides ultrasonography, skeletal radiographs, or even fetoscopy, may indeed contribute to the prenatal diagnosis of TAR syndrome, and thus may help in differentiating TAR syndrome from other syndromes with malformations of the upper limbs.     

Failure to detect fetal obstructive uropathy by second trimester ultrasound

The prenatal diagnosis, management and outcome of an hereditary obstructive uropathy is presented. Serial ultrasonic assessment of the fetal urinary tract was carried out from the early second trimester onward. Slight bilateral hydronephrosis as a first sign of obstructive uropathy was only established as late as 30 weeks of gestation. On the basis of weekly ultrasound scans, a conservative approach was adopted. In view of fetal maturity, labour was induced at 36 weeks resulting in the vaginal delivery of a male infant with moderate bilateral hydronephrosis. Neonatally, anuria developed due to bilateral obstruction of the ureters as a result of increasing bladder wall hypertrophy due to urethral valves. A bilateral uretero-cutaneostomy was carried out. The infant so far develops normally, and renal function is normal for age. Women at risk for fetal obstructive uropathy should have ultrasonic monitoring throughout pregnancy.