Basal Ti level in the human placenta and meconium and evidence of a materno-foetal transfer of food-grade TiO2 nanoparticles in an ex vivo placental perfusion model.

BACKGROUND: Titanium dioxide (TiO2) is broadly used in common consumer goods, including as a food additive (E171 in Europe) for colouring and opacifying properties. The E171 additive contains TiO2 nanoparticles (NPs), part of them being absorbed in the intestine and accumulated in several systemic organs. Exposure to TiO2-NPs in rodents during pregnancy resulted in alteration of placental functions and a materno-foetal transfer of NPs, both with toxic effects on the foetus. However, no human data are available for pregnant women exposed to food-grade TiO2-NPs and their potential transfer to the foetus. In this study, human placentae collected at term from normal pregnancies and meconium (the first stool of newborns) from unpaired mothers/children were analysed using inductively coupled plasma mass spectrometry (ICP-MS) and scanning transmission electron microscopy (STEM) coupled to energy-dispersive X-ray (EDX) spectroscopy for their titanium (Ti) contents and for analysis of TiO2 particle deposition, respectively. Using an ex vivo placenta perfusion model, we also assessed the transplacental passage of food-grade TiO2 particles. RESULTS: By ICP-MS analysis, we evidenced the presence of Ti in all placentae (basal level ranging from 0.01 to 0.48 mg/kg of tissue) and in 50% of the meconium samples (0.02-1.50 mg/kg), suggesting a materno-foetal passage of Ti. STEM-EDX observation of the placental tissues confirmed the presence of TiO2-NPs in addition to iron (Fe), tin (Sn), aluminium (Al) and silicon (Si) as mixed or isolated particle deposits. TiO2 particles, as well as Si, Al, Fe and zinc (Zn) particles were also recovered in the meconium. In placenta perfusion experiments, confocal imaging and SEM-EDX analysis of foetal exudate confirmed a low transfer of food-grade TiO2 particles to the foetal side, which was barely quantifiable by ICP-MS. Diameter measurements showed that 70 to 100% of the TiO2 particles recovered in the foetal exudate were nanosized. CONCLUSIONS: Altogether, these results show a materno-foetal transfer of TiO2 particles during pregnancy, with food-grade TiO2 as a potential source for foetal exposure to NPs. These data emphasize the need for risk assessment of chronic exposure to TiO2-NPs during pregnancy.

Quantitative evaluation of renal function in healthy Beagle puppies and mature dogs.

Daily urinary collection and assessment of glomerular filtration rate (GFR) and effective renal plasma flow were performed in ten 2-month-old Beagle puppies and ten 6-9 year-old Beagle dogs to identify age-associated differences in renal function. The most striking differences in puppies compared to mature dogs were a higher daily urinary volume (+65%), GFR (+87%), free water reabsorption (+159%), a lower daily protein excretion (-88%), and fractional excretion of phosphorus (-35%). Renal function in Beagle puppies, but not mature dogs, was also quite different compared to data published in younger adult dogs.

Effects of the repeated distribution of sainfoin hay on the resistance and the resilience of goats naturally infected with gastrointestinal nematodes.

Due to the high prevalence of anthelmintic resistance in goats, the need to explore novel approaches to control nematodes and to reduce the exclusive reliance on chemotherapy is strongly demanded in this host species. In sheep, several studies have shown that the consumption of tannin-rich legume forages was associated with positive effects on host resilience and resistance to parasite infection. In goats, studies on such interactions between tanniferous plants and nematode infections remain few. The objectives of the current study were to examine under natural conditions the effects of consumption of sainfoin hay by goats on the parasite populations and on host resilience. Eighteen adult cull goats naturally infected with Haemonchus contortus, Teladorsagia circumcincta and Trichostrongylus colubriformis were used in the study. At the start of the assay, the goats were allocated into two groups, balanced according to weight and the levels of egg excretion. The two groups grazed separate pastures for 3 months with similar stocking rates. Goats from group S received each month indoors, for 7 days, sainfoin hay and control goats (group C) received hay of ryegrass. The diets in both groups were made isoenergetic and isoproteic and the refusals measured. Individual parasitological and pathophysiological measurements were performed fortnightly in order to compare host resistance and resilience. At the end of the study, five goats per group were necropsied. The distribution of sainfoin was associated with: (1) a higher consumption of hay; (2) significant, lower levels of nematode egg excretion which was associated with a decrease in worm fertility but no change in worm population; however, the number of intestinal worms was reduced by 50% in group S; (3) a better host resilience. In particular, after 2 months of grazing, two control goats died and half of the remaining animals needed to be treated whereas this was not the case in group S. These differences were related to significant changes in pepsinogen and phosphate values (PCV) but not in pepsinogen and phosphate concentrations. These results demonstrate that a repeated distribution of sainfoin hay to grazing goats might be beneficial in regard of pasture contamination and host resilience. They suggest that administration of sainfoin hay might represent a valuable alternative and adjunct to reduce nematode infections in dairy goat flock.

The accuracy of the i-STAT portable analyser for measuring blood gases and pH in whole-blood samples from dogs.

To assess the suitability of the i-STAT portable analyser for use by non-laboratory personnel, we measured blood gases and pH in venous blood samples from 100 dogs. Deming's regression and bias plots were used to compare i-STAT results with those obtained by laboratory professionals using two different autocalibrated benchtop analysers. Overall accuracy of the portable analyser proved excellent for pH, pO(2), and pCO(2) (r=0.978, 0.968 and 0.997, respectively), with Deming's regression slopes close to 1.00 (0.96, 0.97 and 1.08 for pH, pO(2), and pCO(2), respectively) and intercepts close to zero (0.28, 0.47 kPa and 0.46 kPa for pH, pO(2), and pCO(2), respectively). The accuracy of the i-STAT was also satisfactory for calculated parameters: bicarbonates, total CO(2), base excess and oxygen saturation. Our findings show this portable analyser to be a valid substitute for expensive benchtop analysers in situations requiring mobility, or when small numbers of tests are to be performed by users not specialized in laboratory techniques.

Susceptibility of high and low producer dairy goats to single experimental infection with Trichostrongylus colubriformis.

Culled dry dairy goats, which differed in their level of production in previous lactations, received a single infection with Trichostrongylus colubriformis. The objectives of the study were twofold. First, the study aimed at examining the ability of dairy goats to develop an immune response to trichostrongyle infection and the associated cellular changes developing within the intestinal mucosa. Second, a comparison between animals differing in their level of production was assessed, in order to determine whether these differed in their susceptibility to infection. No difference occurred in egg excretion, worm burden and local inflammatory cell responses between high (HP) and low (LP) producer dairy goats, in contrast to observations in previous studies. Because their nutrition was controlled and milk production absent in the goats employed in the present study, these results suggest that any genetic component associated with the selection of HP and LP goats had little influence on the development of acquired resistance to T. colubriformis. The analysis of the relationship between different cell types in the mucosa and some characteristics of the worm population show that eosinophils are negatively related to worm burden. Also, a role is suggested for mast cells and globule leukocytes in the modulation of egg excretion.

Lower alkaline phosphatase activity and occurrence of an abnormal hybrid intestinal/tissue non-specific isoform in Down's syndrome amniotic fluids.

Quantitative and qualitative analysis of alkaline phosphatases (AP) was performed on amniotic fluid in 59 normal pregnancies and 14 Down's syndrome (DS) pregnancies at 16, 18 and 19 weeks of gestation. In DS cases, intestinal and placental isoenzyme levels were significantly reduced (P<0.001) and the AP electrophoretic pattern was seen to be modified on polyacrylamide gel electrophoresis. A unique component was detected. After extraction and purification of the abnormal isoenzyme, peptide fragments obtained after cyanogen bromide cleavage indicated a hybrid heterodimeric AP composed of intestinal and tissue non-specific subunits, as evaluated by SDS polyacrylamide gel electrophoresis.

Water restriction and bone metabolism in camels.

'Krafft disease', occurring in camels living in the very arid areas of North Africa, is characterized by spontaneous fractures of costal and/or appendicular bones. To better understand the mechanisms of this, we studied the influence of water restriction on plasma and urinary markers of bone metabolism in camels. Eight 2-year-old nonpregnant, nonlactating camels were studied at the research station of Laâyoune (Morocco). After a 10 day period of daily watering, five animals were watered only every 10th day over a 50 day period, then again watered daily for a final 10 day period (rehydration). The three control animals were watered daily throughout the whole experimental period (70 days). Each camel was fed a ration of straw, luceme hay and barley, resulting in a daily intake of 25 g calcium and 11 g phosphorus. Water restriction induced a decrease in daily urinary volume and an increase in plasma osmolality. These symptoms of dehydration were not associated with any significant change either in the markers of osteoblastic activity (plasma alkaline phosphatase activity and osteocalcine concentration) or in the markers of bone resorption (urinary excretion of calcium, hydroxyproline pyridinoline and deoxypyridinoline). Thus, in well-fed camels, water restriction did not affect bone metabolism. However, no conclusions were possible regarding the influence of dehydration or calcium and/or phosphorus deficiency in the etiology of 'Kraft disease'.

Serum chemistry values for Arabian sand gazelles (Gazella subgutturosa marica).

Values for urea, creatinine, glucose, total bilirubin, sodium, potassium, chloride, calcium, phosphates, magnesium, alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase, lactate deshydrogenase, and creatine-kinase are reported for the first time for 32 sand gazelles (Gazella subgutturosa marica) in Saudi Arabia. Comparisons were made between two groups: one sampled before a trip and the other sampled after a 14 hr trip. Only aspartate aminotransferase was higher in the second group; magnesium and phosphates were lower in that group.

Hormonal control of water and sodium in plasma and urine of camels during dehydration and rehydration.

Eight dromedary camels were studied for 24 days under control conditions (3 days), and during water deprivation (14 days) and rehydration (7 days) in Tadla (Morocco), during the summer. During dehydration, food intake gradually fell and was zero on the last day and animals lost about 30% of their body weight. However, most of this reduction in weight was attributed to water loss, since body weight of the animals returned to control values following rehydration. Dehydration was associated with a decrease in plasma volume (-42 +/- 3%) and a concomitant rise in plasma Na concentration (from 154 +/- 2 to 191 +/- 3 mM). These changes were accompanied by increased plasma arginine-vasopressin (from 0.2 +/- 0.1 to 5.7 +/- 2.2 pg ml-1) and plasma renin activity (from 1.2 +/- 0.2 to 20.0 +/- 5.2 ng Al ml-1 hr-1), without significantly changed plasma concentrations of aldosterone and atrial natriuretic peptide. Dehydration was associated with increased urine osmolality (from 952 +/- 515 to 1963 +/- 498 mosm kg-1 H2O), reduced urine production (from 4565 +/- 2230 to 817 +/- 178 ml day-1), and increased Na excretion. Most of these parameters returned to control values during initial rehydration, except for plasma renin activity, which remained elevated for 7 days, and diuresis, which rose to 12773 +/- 6707 ml day-1 on Day 7 of rehydration.

Serum reference values of the Cynomolgus monkey, a model for the study of atherosclerosis.

The usual biochemical parameters were evaluated in 19 Cynomolgus monkeys (male and female), receiving a normal balanced diet. The values were near those reported in man, although certain differences were observed.

The influence of phthalate esters on human plasma lecithin/cholesterol acyltransferase.

The effect of various phthalate esters on the lecithin/cholesterol acyltransferase activity in man was studied in vitro. The enzymatic activity was strongly reduced with all phthalates except for the dimethyl phthalate. The inhibition rate depends on the phthalate concentration and also on the carbon number of the alkyl groups of phthalates.

[Effect of phthalic esters on lecithin cholesterol acyltransferase]. / Effets des esters de l'acide phtalique sur la l'cithine-cholestérol-acyltransférase.

The in vitro effects of different esters of phthalic acid at increasing levels on the activity of LCAT have been studied using three currently known methods (Mickel and Foulds, Stokke and Norum, Alcindor). Inhibition from phthalates is high. It is proportional to the amounts used and in inverse ratio to the length of the carbon chains.

[Localization of dioctyl-phthalate on normal immunoglobulins G and on those of Kahler's disease (author's transl)]. / Localisation de dioctyl-phtalate sur les immunoglobulines G normales et sur celles de la maladie de Kahler

After having identified as dioctyl-phthalate (DOP), a plasticizer that comes out with fatty acids of normal immunoglobulins G (IgG) and of those of Kahler's disease, we found out that DOP is preferentially bound to the heavy chains of IgG and is either missing from myeloma proteins or more abundant in them than in normal ones.

[Fatty acids from papain fragments of normal and myeloma immunoglobulins G]. / Les acides gras des fragments papaïniques des immunoglobulines G normales et myélomateuses

Studying the lipids bound on normal and myelomatous IgG, we have compared, using gas-liquid chromatography, the fatty acids extracted from untreated proteins, from papain hydrolysis and from Fab and Fc fragments. These last have been purified with affinity chromatography. We have been able, using mass spectrometry, to identify one of the various unknown compounds: it is di-octyl-phthlate.

[Quality control of analyses and automation]. / Contrôle de qualité des analyses et automation

Multichannel analysers are becoming more and more usual in biochemistry laboratories. Then, a very severe quality control program is requisite. In Toulouse a three years experiment was carried out on a computer connected twenty four channels Autochemist and an unconnected Technicon SMA 12/60. The traditional quality control from control lyophilized serums is still necessary and useful, mainly at the level of a region. The remaining valuable methods are automatic calibration and statistical controls on frequently tested samples from human polled serum and on results from patients, these being provided through various procedures.