Quantitative analysis of vitamin D and its main metabolites in human milk by supercritical fluid chromatography coupled to tandem mass spectrometry.

A novel method to quantitate vitamin D and its main metabolites (vitamin D3, vitamin D2, and their 25-hydroxy metabolites) in breast milk by supercritical fluid chromatography has been developed and fully validated. A small volume of sample (1 mL) is subjected to ethanolic protein precipitation and liquid-liquid extraction. Final extracts are derivatized with 4-phenyl-1,2,4-triazoline-3,5-dione and vitamin D derivatives analyzed by supercritical fluid chromatography hyphenated to tandem mass spectrometry with atmospheric pressure chemical ionization. Multiple reaction monitoring is used for quantitation. Separation conditions were optimized using a gradient of methanol-water-ammonium formate into carbon dioxide. Make-up solvent was methanol containing ammonium formate. The quantitation limit reached levels as low as 50 pmol/L, with intra- and inter-day relative standard deviations lower than 15% and 20% for all analytes. Accuracy was evaluated by spiking experiments and was well within acceptability ratios (± 15%). The method was then applied to a subset of commercially available human milk samples. The newly developed method provides opportunities to determine the nutritional status of mother-infant dyads from a non-invasive measure, or for interventional or observational studies building knowledge on the composition of human milk. Graphical abstract.

Pre-slaughter stress and horn status influence physiology and meat quality of young bulls.

The study used 81 young bulls, half of which were disbudded at 7 weeks of age. The effects of horn status during rearing and of acute physical and emotional stress just before slaughter on the physiological status at slaughter and subsequent meat quality were investigated. Bulls were reared in groups containing i) only bulls with horns, ii) only bulls without horns, or iii) mixed (half with, and half without horns). Bulls of each rearing condition were assigned to one of two slaughter conditions: with limited (LS) or with supplementary stress (SS). LS resulted in lower heart rates, stress hormone concentrations and carcass temperature, whereas SS resulted in faster post mortem pH decline and lower juiciness. Horned bulls from unmixed rearing groups had lower early pm temperature, shorter sarcomeres, and lower tenderness compared to disbudded bulls. Correlations and regression analysis revealed relationships between physiological indicators, mainly heart rate before slaughter, and meat quality, including water-holding capacity and indicators of proteolysis.

Magnesium absorption as influenced by the rumen passage kinetics in lactating dairy cows fed modified levels of fibre and protein.

The potassium sensitive magnesium absorption through the rumen wall may be influenced by additional dietary properties, such as diet type, forage type or forage to concentrate ratio. These properties are likely associated to rumen passage kinetics modified by dietary fibre content. The study aimed to assess the effects of rumen passage kinetics on apparent Mg absorption and retention in lactating dairy cows fed modified levels of fibre. Six lactating Red-Holstein and Holstein cows, including four fitted with ruminal cannulas were randomly assigned to a 3 × 3 cross-over design. The experimental diets consisted of early harvested low NDF (341 g NDF/kg DM) and late harvested high NDF (572 g NDF/kg DM) grass silage (80% DM) and of concentrates (20% of DM). As the low-fibre diet was excessive in protein, a third high-fibre diet was formulated to be balanced in digestible protein with the low-fibre diet to avoid any eventual confounding effects of NDF and protein excess. All diets were formulated to contain iso-Ca, -P, -Mg, -K and -Na. Passage kinetics of solid and liquid phase of rumen digesta were evaluated using ruminal marker disappearance profiles. Cows fed the low-fibre diet had compared to the other diets, an up to 40% lower solid and 26% lower liquid phase volume of rumen digesta and a 10% numerically higher fractional rumen liquid passage rate. Rumen pH lost 0.6 units and Mg concentration in the rumen liquid phase tripled when cows were fed the low-fibre diet. Faecal Mg excretion was up to 14% higher in cows fed the low-fibre diet and Mg absorbability was 12% compared to up to 19% in other diets. Urinary Mg excretion in cows fed the low-fibre diet was half of the ones in the other treatments, but Mg retention was not affected. Dietary protein excess neither affected rumen passage kinetics nor Mg absorption and retention. Absorption of Mg was correlated with rumen liquid volume which both decreased with decreasing daily NDF intake (NDFi, 11.8 ± 2.4 l/kg NDFi). Consequently, daily Mg absorption decreased by 1.32 ± 0.28 g/kg decreasing NDFi. To conclude, in addition to the known antagonistic effect of dietary K, the present data indicate that Mg absorption was dependent from NDFi which modified rumen liquid volume, but was independent of dietary protein excess likely associated to low NDF herbages.

Development of an electronic radiologist's office in a private institute.

A computer system that improves the quality, user-friendliness, accessibility, and management of radiology data (images, reports, databases, knowledge) was implemented at a private institute. A picture archiving and communication system (PACS) was integrated with the radiology information system (RIS). Two servers and 12 personal computers form the integrated system. The first server is dedicated to management and archiving of Digital Imaging and Communications in Medicine (DICOM) images. The second server is dedicated to management of the RIS and archiving of patient data (Structured Query Language database), reports (hypertext markup language [HTML]), and images in the Joint Photographic Experts Group (JPEG) format (mini-PACS). There are three main client-server networks: a common network of imaging modalities (magnetic resonance imaging, computed tomography, ultrasonography, digital radiography) and two fast Ethernet networks (the PACS network and the RIS network). The RIS-PACS is linked remotely with other workstations and servers via Integrated Services Digital Network (ISDN). Images and reports can be distributed to referring physicians in the form of multimedia HTML and JPEG documents, which can also be used for quick and easy archiving, distribution, and reviewing within the institute. However, referring physicians have been reluctant to use electronic reports and images.

Analysis of the heat-shock response displayed by two Chaetomium species originating from different thermal environments.

Three features of the heat shock response, reorganization of protein expression, intracellular accumulation of trehalose, and alteration in unsaturation degree of fatty acids were investigated in the thermophilic fungus Chaetomium thermophile and compared to the response displayed by a closely related mesophilic species, C. brasiliense. Thermophilic heat shock response paralleled the mesophilic response in many respects like (i) the temperature difference observed between normothermia and the upper limit of translational activity, (ii) the transient nature of the heat shock response at the level of protein expression including both the induction of heat shock proteins (HSPs) as well as the repression of housekeeping proteins, (iii) the presence of representatives of high-molecular-weight HSPs families, (iv) intracellular accumulation of trehalose, and finally (v) modifications in fatty acid composition. On the other hand, a great variability between the two organisms was observed for the proteins expressed during stress, in particular a protein of the HSP60 family that was only observed in C. thermophile. This peptide was also present constitutively at normal temperature and may thus fulfil thermophilic functions. It is shown that accumulation of trehalose does not play a part in thermophily but is only a stress response. C. thermophile contains less polyunsaturated fatty acids at normal temperature than C. brasiliense, a fact that can be directly related to thermophily. When subjected to heat stress, both organisms tended to accumulate shorter and less unsaturated fatty acids.

Membrane lipid integrity relies on a threshold of ATP production rate in potato cell cultures submitted to anoxia

In this paper we report on our study of the changes in biomass, lipid composition, and fermentation end products, as well as in the ATP level and synthesis rate in cultivated potato (Solanum tuberosum) cells submitted to anoxia stress. During the first phase of about 12 h, cells coped with the reduced energy supply brought about by fermentation and their membrane lipids remained intact. The second phase (12-24 h), during which the energy supply dropped down to 1% to 2% of its maximal theoretical normoxic value, was characterized by an extensive hydrolysis of membrane lipids to free fatty acids. This autolytic process was ascribed to the activation of a lipolytic acyl hydrolase. Cells were also treated under normoxia with inhibitors known to interfere with energy metabolism. Carbonyl-cyanide-4-trifluoromethoxyphenylhydrazone did not induce lipid hydrolysis, which was also the case when sodium azide or salicylhydroxamic acid were fed separately. However, the simultaneous use of sodium azide plus salicylhydroxamic acid or 2-deoxy-D-glucose plus iodoacetate with normoxic cells promoted a lipid hydrolysis pattern similar to that seen in anoxic cells. Therefore, a threshold exists in the rate of ATP synthesis (approximately 10 &mgr;mol g-1 fresh weight h-1), below which the integrity of the membranes in anoxic potato cells cannot be preserved.

Color Doppler ultrasound for evaluation of collagen implants after endoscopic injection treatment of refluxing ureters in children.

To determine whether color Doppler ultrasonography (CDUS) would add to the understanding of the bladder wall after endoscopic subureteral collagen injection (SCIN), 25 patients were studied with CDUS. The kidney length and echogenicity, the volume of the collagen, the mean length of the urinary jet, the longitudinal and transverse angles, and the distance between the origin of the jet and the midline of the bladder were measured 1 day, 1 month, and 3 months after SCIN and compared to the results of micturating cystourethrograms (MCUs) performed 3 months after SCIN. The collagen was hyperechogenic compared to the bladder wall at the time of injection, and was isoechogenic 1 and 3 months after SCIN. CDUS showed the relationship between the injected collagen and the position of the ureteral orifice. The measurements of jet length, angle, and distance of the ureteral orifice from the midline did not correlate with vesicoureteral reflux assessed by MCU. Although CDUS may demonstrate the location, the size of the injected collagen implant, and its relationship to the ureteral orifice, it is as yet unable to predict vesicoureteral reflux after SCIN.

Magnetic resonance imaging of the shoulder in children with brachial pLexus birth palsy.

Five patients suffering from Erb-Duchenne brachial plexus birth palsy were prospectively studied with MRI. A group of 11 healthy children was used as a control to understand the MRI anatomy of the normal growing glenohumeral joint. A hypoplastic and flattened posterior part of the glenoid fossa and a blunt posterior labrum were found in all patients. Four patients had a blunt anterior labrum and a flattened humeral head. Three patients presented with a posterior subluxation of the humeral head. These results suggest that MRI provides a non-ionising and non-invasive method of demonstrating the early abnormalities of the shoulder associated with obstetrical brachial plexus paralysis, which may prompt orthopaedic correction.