Prenatal cytogenetic diagnosis after transabdominal chorionic villus sampling in the first trimester

First trimester prenatal cytogenetic diagnosis was attempted in 350 pregnancies after trans-abdominal chorionic villus sampling. The cytogenetic investigation was performed using both a short-term method (24 h incubation) and cell culture. Adequate samples were obtained in 99·1 per cent and in all these cases the fetal karyotype was established. A chromosome abnormality was found in 2·0 per cent of cases. A discrepancy between the karyotype obtained after 24 h incubation and the karyotype in cell culture was observed in 2·3 per cent. Maternal cell contamination in the cultures was confirmed in 13 of 181 cases where the 24 h incubation revealed a male karyotype. Studies of culture morphology showed that colonies of convoluted cells may serve as a marker for contamination with maternal cells in culture. For the present, we recommend using a short-term method as well as cell culture for cytogenetic investigation until the problems with karyotype discrepancy and maternal cell contamination have been further clarified.     

Trisomy 7 in chorionic villi: Follow-up studies of pregnancy,normal child,and placental clonal anomalies

Cytogenetic study of chorionic villi sampled because of advanced maternal age revealed, after overnight culture, an apparently non-mosaic trisomy 7. Amniocentesis showed exclusively normal mitoses, and the pregnancy continued normally. One hundred mitoses from cord blood of the normal newborn revealed a non-mosaic 46,XX complement. No cells with a proven trisomy 7 were found in cultures from either of two biopsies of the morphologically normal placenta, but the peripheral biopsy showed in multiple cultures an abnormal clone: 47,XX, + 20,-2,-21, + t(2;21)(p13;q22). To our knowledge, this is the first case of non-mosaic trisomy 7 detected on CVS which has had follow-up studies of amniotic fluid, cord blood, and term placenta.     

Inhibitory effects of nisin-coated multi-walled carbon nanotube sheet on biofilm formation from Bacillus anthracis spores

Multi-walled carbon nanotube（MWCNT） sheet was fabricated from a drawable MWCNT forest and then deposited on poly（methyl methacrylate） film. The film was further coated with a natural antimicrobial peptide nisin. We studied the effects of nisin coating on the attachment of Bacillus anthracis spores, the germination of attached spores, and the subsequent biofilm formation from attached spores. It was found that the strong adsorptivity and the super hydrophobicity of MWCNTs provided an ideal platform for nisin coating. Nisin coating on MWCNT sheets decreased surface hydrophobicity, reduced spore attachment, and reduced the germination of attached spores by 3.5 fold, and further inhibited the subsequent biofilm formation by 94.6% compared to that on uncoated MWCNT sheet. Nisin also changed the morphology of vegetative cells in the formed biofilm.The results of this study demonstrated that the anti-adhesion and antimicrobial effect of nisin in combination with the physical properties of carbon nanotubes had the potential in producing effective anti-biofilm formation surfaces.     

Determinants of parental decisions to abort for chromosome abnormalities

Parental decisions concerning the continuation of pregnancy following prenatal detection of abnormal chromosomes were evaluated for 80 patients whose diagnosis and prenatal counselling were performed in our centre. Twenty-two anomalies were diagnosed by chorionic villus sampling (CVS) and 58 by amniocentesis. The severity of the chromosome anomaly and associated ultrasound findings in the first vs. second trimester were correlated with patients' decisions. No difference was found in the likelihood of parental decisions to interrupt or continue a pregnancy between CVS and amniocentesis for either the‘severe’ or the‘questionable’ group of chromosome anomalies. Ninety-three per cent of patients with severe prognosis and 27 per cent with questionable prognosis opted for pregnancy termination (p <0·0001). The association of ultrasound anomalies and termination was highly significant (p< 0·001). The severity of the chromosome anomaly, and, to a lesser extent, the visualization of anomalies on ultrasound were the major determinants of parental decisions to terminate the pregnancy. The diagnosis of an anomaly in the first trimester was no more likely ito lead to a termination of pregnancy than in the second trimester.     

Whitefly wax as a cue for phoresy in the broad mite, <Emphasis Type="Italic">Polyphagotarsonemus latus</Emphasis>(Acari: Tarsonemidae)

Summary. Broad mite, Polyphagotarsonemus latus (Acari: Tarsonemidae) exhibits a specific phoretic relationship with whiteflies. Under field conditions most broad mites, caught in sticky traps, are attached to whiteflies. Under laboratory conditions, attachment occurs equally well in the dark and light. Mites do not differentiate between the sexes of their phoretic host Bemisia tabaci. However, mite attachment to B. tabaci is greatly diminished by washing the host with various organic solvents, chloroform in particular. The effect of whitefly waxy particles on broad mite behavior was studied using wax from the whitefly Aleyrodes singularis and from the mealybug Planococcus citri. Broad mites were not only attracted specifically to the A. singularis waxy particles-treated leaf areas but were also attached to leaf trichomes in this area. The results of this study suggests the importance of olfactory cues from the whitefly waxy particles in the recognition process of the phoretic host and/or the induction of the attachment behavior to whitefly legs or leaf trichomes.     

Experimental exposure of juvenile savannah monitors (Varanus exanthematicus) to an environmentally relevant mixture of three contaminants: effects and accumulation in tissues

Using varanids as indicators of pollution in African continental wetlands was previously proposed. The present study aimed at understanding experimentally how monitors absorb and accumulate pollutants and how they are affected. The relevance of non-destructive sampling was also evaluated. Savannah monitors (Varanus exanthematicus) were orally exposed during 6 months to a mixture of lead, 4,4′-dichlorodiphenyltrichloroethane (4,4′-DDT) and chlorpyrifos-ethyl (CPF) or to the vehicle only. Proportionally to their mass, exposed monitors received the same dose: 20 then 10 mg lead?kg^?1, 2 then 0.5 mg CPF?kg^?1 and 4 mg 4,4′-DDT?kg^?1. Individuals surviving contamination were euthanized after 4 or 6 months of experiment. Tissues were analysed for lead by atomic absorption spectrophotometry and for DDT and CPF by gas chromatography. Exposed monitors absorbed all three pollutants but only lead (essentially in bone, tail tips and phalanxes) and 4,4′-DDT plus its main metabolites (essentially in fat and liver) accumulated. CPF killed ten individuals. Clear correlations occurred between the total quantity of lead or 4,4′-DDT administered and concentrations in tissues. Tail tips and skin samples are recommended non-destructive indicators for lead and organochlorine pesticides contamination, respectively. This work confirms that monitors can be used as relevant indicators of environmental pollution by lead and organochlorine pesticides. Although varanids withstand heavy lead and DDT contamination, our results suggest that CPF can be lethal at very low doses to the herpetofauna and emphasize the importance of considering all taxa in impact assessment studies, including reptiles.     

Fast and complete removal of the 5-fluorouracil drug from water by electro-Fenton oxidation

Cytostatic drugs are a troublesome class of emerging pollutants in water owing to their potential effects on DNA. Here we studied the removal of 5-fluorouracil from water using the electro-Fenton process. Galvanostatic electrolyses were performed with an undivided laboratory-scale cell equipped with a boron-doped diamond anode and a carbon felt cathode. Results show that the fastest degradation and almost complete mineralization was obtained at a Fe²⁺ catalyst concentration of 0.2 mM. The absolute rate constant for oxidation of 5-fluorouracil by hydroxyl radicals was 1.52 × 10⁹ M^?1 s^?1. Oxalic and acetic acids were initially formed as main short-chain aliphatic by-products, then were completely degraded. After 6 h the final solution mainly contained inorganic ions (NH₄ ⁺, NO₃ ^? and F^?) and less than 10% of residual organic carbon. Hence, electro-Fenton constitutes an interesting alternative to degrade biorefractory drugs.     

Treatment of fluoride-contaminated water. A review

Environmental Chemistry Letters - Delivering the right amount of fluoride to drinking water protects the&nbsp;teeth from decay and reduces the risk of cavities. Nonetheless, fluorosis has been...