Factors affecting feasibility and quality of second-trimester ultrasound scans in obese pregnant women.

OBJECTIVES: To evaluate the feasibility of completing in one session a second-trimester ultrasound scan in obese pregnant women, to compare the quality of images obtained with those of non-obese women and to analyze factors that can improve the completion rate. METHODS: This prospective study, from 2009 to 2011, included all obese pregnant women (prepregnancy body mass index (BMI) > 30 kg/m2) who had an ultrasound examination at 20-24 weeks in our department, and a control group of pregnant women with normal BMI (20-24.9 kg/m2) who had the same examination. A single operator reviewed the standardized ultrasound images (three biometric and six to assess key anatomical features) required under French guidelines, to assess their presence, evaluate the quality of all images and score the quality of the six anatomical images. Each image was assessed according to between four and six criteria, each worth one point. We sought excellent quality, defined as the frequency of maximum points for a given image type. The factors associated with completing the scan in one session were evaluated with multivariate logistic regression. RESULTS: The obese group included 223 women and the control group 60; a complete scan in one session was achieved in 70.4% and 81.7% of these, respectively (P = 0.08). The completion rate for each image type was at least 95% in the control group and 90% in the obese group, except for diaphragm and right outflow tract images. Significant factors associated with completing the scan in the multivariate model were: having 10 additional minutes for the scan (P = 0.03), moving the fetus so that the back was in posterior or lateral position (P = 0.01), more experienced sonographer (P = 0.03) and thinner maternal abdominal wall thickness (P = 0.01). Overall, the excellence rate varied from 35% to 92% in the normal BMI group and from 18% to 58% in the obese group, and was significantly lower in the latter for all images except abdominal circumference (P = 0.26) and spine (P = 0.06). Anatomical quality scores were also significantly lower in the obese group (22.3 vs. 27.2; P = 0.001). CONCLUSION: Although ultrasound scans of obese pregnant women are feasible, image quality and global anatomical scores are significantly lower among obese than normal-weight women. However, certain simple improvements may increase fetal visualization.

Electrochemical treatment of a simple azodye and analysis of the degradation products using high performance liquid chromatography-diode array detection-tandem mass spectrometry.

The simple, low molecular weight, azodye acid yellow 9 (AY9) is electrochemically treated in a suitable electrolytic cell using NaCl as a supporting electrolyte, carbon fleece as cathode and platinated titanium as anode. Samples from certain time periods of treatment are analysed. HPLC-UV chromatograms demonstrate the degradation of the initial azodye, while diode array detector (DAD) spectra give evidence concerning the aromaticity of the degradation products and tandem mass spectrometry (MS(2)) offer structural information on some final products. In order to distinguish cathodic and anodic processes, separated cells connected with electrolytic junction are used, clarifying the oxidative and reductive decomposition pathways of the studied azodye. Several intermediate products are identified in very low concentrations such as hydrazo-derivatives, chlorinated aromatic and aliphatic compounds as well as amino- and hydroxyl-products. Experiments in separated electrolytic cells show that azodye degradation proceeds mainly oxidatively, since cathodic action is extremely limited, while treatment in common cells results in complete decoloration and presence of degradation products in very low concentration. Finally, simple degradation mechanisms are suggested based on tandem mass spectrometric identification of several degradation products.

Voltammetric study of interaction between polymers (PEI and TMO) and pDNA on a hanging mercury drop electrode.

Electrochemical DNA biosensors can become a powerful tool for the investigation of potent changes on the plasmid DNA structure caused by polymers used as non-viral vectors in gene delivery. Trimethylated chitosan oligomer (TMO) and polyethylenimine (PEI), offering biocompatibility, low immunogenicity and minimal cytotoxicity, are being studied as model non-viral carriers. The information obtained is intended to serve as a basis for developing a new analytical system for the study of the effect of any physically or chemically synthesized polymer on DNA structure.

Simultaneous determination of tetrathiomolybdates and molybdates in spiked blood plasma by differential pulse voltammetry and their speciation.

A selective, sensitive and reliable voltam- metric method for the simultaneous determination of MoS(2-)(4) and MoO(2-)(4) has been developed. The reduction of HgMoS(4) at -0.43 V and the reduction of Mo as complex of MoO(2)-oxine(2) at -0.63 V in acetate buffer at pH 4.9 are utilized for the simultaneous determination by differential pulse cathodic stripping voltametry (DPCSV). Cadmium and lead form complexes with MoS(2-)(4), but do not interfere with the determination. The limit of detection is 0.59 microg/l Mo for MoS(2-)(4) and 1.8 microg/l Mo for MoO(2-)(4). The R.S.D at a concentration level of 20 microg/l is 4.7% for MoO(2-)(4) and 3.6% for MoS(2-)(4). The method is applied to spiked blood plasma samples for the determination of free tetrathiomolybdates and molybdates. Additionally, labile tetrathiomolybdates and molybdates can be determined in spiked blood plasma after treatment of the sample with 0.15 mol/l KCN and ultrafiltration.

Fluorometric determination of biacetyl.

The fluorometric determination of biacetyl is described. 3,4-Diaminoanisole reacts with biacetyl in alkaline ethanol-water solution to give strongly fluorescing 2,3-dimethyl-6-methoxy-quinoxaline. Variables such as solvent composition, quenching by acetic and sulphuric acid, heating time and interference by other carbonyl compounds present are discussed. The method may be suitable for the determination of biacetyl in foodstuffs.

A study of the determination of the hypertensive drug captopril by square wave cathodic adsorptive stripping voltammetry.

In this work, the determination of captopril (CPL) was studied by square wave cathodic adsorptive stripping voltammetry (SWCAdSV) on a hanging mercury drop electrode (HMDE). CPL was adsorptively preconcentrated on the mercury surface as a sparingly soluble mercury salt under stirring of the solution and then the accumulated species was reduced by a cathodic square wave voltammetric scan. The reduction current was related to the CPL concentration in the sample. The chemical and instrumental parameters affecting the response were investigated and optimized for the CPL determination. The calibration curve was linear from 0.5 to 180 microg l(-1) of CPL (depending on the preconcentration time), the limit of detection at a S/N ratio of 3 was 0.5 microg l(-1) with 300 s of preconcentration and the relative standard deviation was 3.2% at the 20 microg l(-1) level (with 120 s of preconcentration, n=8). The method was applied to the determination of CPL in two pharmaceutical formulations with recoveries of 97.9 and 98.8%. Finally, the potential for applying the proposed method to the determination of CPL in biological media is briefly discussed.

Study of interactions between actinomycin D and DNA on carbon paste electrode (CPE) and on the hanging mercury drop (HMDE) surface.

The interaction of actinomycin (ACTD) with double stranded (ds) calf thymus DNA and single stranded (ss) DNA was studied at the carbon paste electrode surface by means of transfer voltammetry in 0.2 M phosphate buffer solution (pH 7.4). Accordingly the interaction of actinomycin (ACTD) with ds calf thymus DNA, ss DNA and supercoiled (sc) DNA was studied using hanging mercury drop electrode in 0.3 M NaCl, and 50 mM sodium phosphate buffer (pH 8.5). The different electrochemical behaviours are presented and compared in the article.

Aspects of protein bound copper in sheep plasma and its release in vitro especially after treatment with ammonium tetrathiomolybdate.

The distribution of protein-bound copper in sheep plasma between a globulin and an albumin fraction, as well as copper release in vitro by means of various agents, either from the above-mentioned fractions or from those formed after ammonium tetrathiomolybdate (TTM) treatment, were studied. Copper bound in both plasma globulin and albumin (CuGA) is 95.1% of the total plasma copper (CuT); copper release from the globulin fraction by means of trichloracetic acid (TCA) or cyanides (CN-) is relatively low, 17.1% and 25.8% respectively, while there is not any copper release after TTM treatment; however, the copper release from the albumin fraction by means of TCA and CN- is relatively high, 59.2% and 74.9%, respectively, while the treatment with TTM has the same effect of no copper release as mentioned above for the globulin fraction.

Determination of cobalt in vegetable animal foodstuffs by differential pulse adsorptive voltammetry using alpha-benzil dioxime.

A selective and sensitive voltammetric method for the determination of cobalt in vegetable animal foodstuffs is developed. The method is based on the use of alpha-benzil dioxime (alpha-BD) as a chelating agent for differential pulse adsorptive stripping voltammetry (DPASV) and is free from zinc interferences. The influence of pH, time and alpha-BD concentration on the peak resolution and height are discussed. The method was successfully applied in some typical vegetable animal foodstuffs with R.S.D. < 6%.

[Could we perform quality second trimester ultrasound among obese pregnant women?]. / Peut-on faire des échographies obstétricales de qualité chez les patientes obèses ? Étude monocentrique sur 30 mois.

OBJECTIVE: To compare the quality of second trimester ultrasound images and their anatomical quality scores among obese women and those with a normal body mass index (BMI). MATERIALS AND METHODS: This prospective study, which took place from 2009 to 2011, included every obese pregnant woman (prepregnancy BMI greater than 30 kg/m(2)) who had an ultrasound examination at 20 to 24 weeks in our hospital and a control group with a normal BMI (20-24.9kg/m(2)) who had the same examination. A single operator evaluated the quality of all images, reviewing the standardized ultrasound planes - three biometric and six anatomical - required by French guidelines and scoring the quality of the six anatomical images. Each image was assessed according to 4-6 criteria, each worth one point. We sought excellent quality, defined as the frequency of maximum points for a given image. RESULTS: The obese group included 223 women and the control group 60. The completion rate for each image was at least 95 % in the control group and 90 % in the obese group, except for diaphragm and right outflow tract images. Overall, the excellence rate varied from 35 % to 92 % in the normal BMI group and 18 % to 58 % in the obese group and was significantly lower in the latter for all images except abdominal circumference (P=0.26) and the spine (P=0.06). Anatomical quality scores were also significantly lower in the obese group (22.3 vs. 27.2 ; P=0.001). CONCLUSION: Image quality and global anatomical scores in second trimester ultrasound scans were significantly lower among obese than normal-weight women.

Some aspects of chronic copper poisoning in sheep.

The variations in an analytical fraction of plasma copper, as well as those of direct and indirect plasma bilirubin, were studied for a period of twenty-three days in ten native crossbred sheep suffering from chronic copper poisoning. The findings of the experiment, which was begun just before the appearance of any acute symptoms, show that the proportion of the above fraction of plasma copper, characterized as "soluble in trichloroacetic acid" (STAPC), represents approximately 45% as a mean percentage of the total plasma copper (TPC), while in the controls it was 12%; further, the former proportion, despite progressive reduction in the absolute values on the respective concentrations, shows, at least during the course of the experiment, a relatively small decrease, while in the controls it remains constant. Further findings regarding direct and indirect plasma bilirubin are discussed.

A study of bismuth-film electrodes for the detection of trace metals by anodic stripping voltammetry and their application to the determination of Pb and Zn in tapwater and human hair.

This work reports the simultaneous determination of Cd(II), Pb(II) and Zn(II) at the low mug l(-1) concentration levels by square wave anodic stripping voltammetry (SWASV) on a bismuth-film electrode (BFE) plated in situ. The metal ions and bismuth were simultaneously deposited by reduction at -1.4 V on a rotating glassy carbon disk electrode. Then, the preconcentrated metals were oxidised by scanning the potential of the electrode from -1.4 to 0 V using a square-wave waveform. The stripping current arising from the oxidation of each metal was related to the concentration of each metal in the sample. The parameters for the simultaneous determination of the three metals were investigated with the view to apply this type of voltammetric sensor to real samples containing low concentrations of metals. Using the selected conditions, the limits of detection were 0.2 mug l(-1) for Cd and for Pb and 0.7 mug l(-1) for Zn at a preconcentration time of 10 min. Finally, BFE's were successfully applied to the determination of Pb and Zn in tapwater and human hair and the results were in satisfactory statistical agreement with atomic absorption spectroscopy (AAS).

Study of interactions between DNA-ethidium bromide (EB) and DNA-acridine orange (AO), in solution, using hanging mercury drop electrode (HMDE).

The interaction of ethidium bromide (EB) and acridine orange (AO) with double stranded (ds), thermally denatured (ss) and supercoiled (sc) DNA, in solution, was studied by alternating current voltammetry (AC voltammetry) at the hanging mercury drop electrode (HMDE) in 0.3 M NaCl+50 mM sodium phosphate buffer (pH 8.5). Their interaction with DNA is shown to be time dependent and completely different. The changes at peak 2 (peak at -1.20 V) of dsDNA form and the appearance of peak 3 (peak at -1.42 V) in scDNA form are presented as criteria declaring the different mechanism of interaction of EB and AO with DNA. Additionally, the appearance of a new peak at around -0.44 V as a result of DNA and AO interaction, differentiates the studied behaviors. The comparison of the electrochemical behaviors of these compounds highlights the differences in the mechanism of interaction.