Integrating metabolomics profiling measurements across multiple biobanks.

To optimize the quality of large scale mass-spectrometry based metabolomics data obtained from semiquantitative profiling measurements, it is important to use a strategy in which dedicated measurement designs are combined with a strict statistical quality control regime. This assures consistently high-quality results across measurements from individual studies, but semiquantitative data have been so far only comparable for samples measured within the same study. To enable comparability and integration of semiquantitative profiling data from different large scale studies over the time course of years, the measurement and quality control strategy has to be extended. We introduce a strategy to allow the integration of semiquantitative profiling data from different studies. We demonstrate that lipidomics data generated in samples from three different large biobanks acquired in the time course of 3 years can be effectively combined when using an appropriate measurement design and transfer model. This strategy paves the way toward an integrative usage of semiquantitative metabolomics data sets of multiple studies to validate biological findings in another study and/or to increase the statistical power for discovery of biomarkers or pathways by combining studies.

A retrospective study of gastric dilatation and gastric dilatation and volvulus in working farm dogs in New Zealand.

AIMS: To present findings from a case series of gastric dilatation (GD) or gastric dilatation and volvulus (GDV) in working farm dogs in New Zealand that were examined at veterinary clinics, and to identify possible risk factors for GD or GDV in working farm dogs in New Zealand using a case-control study. METHODS: This retrospective study included a case-series and a case-control study. The case series analysed information from 62 case records of GD or GDV in working farm dogs seen between August 2004 and September 2009 at 13 veterinary clinics throughout New Zealand. Cases were classified as GD or GDV if the diagnosis was confirmed by radiography, surgery or post-mortem examination. Details of history and treatment, as well as outcomes, were obtained for each case. For the case-control study, records of 41 working farm dogs with GD or GDV (cases) seen between April 2008 and April 2009, and 82 working farm dogs examined because of trauma over the same period and in the same 13 clinics (controls), were used to model the risk factors for GD or GDV. RESULTS: From the case-series study, 40/62 (65%) cases of GD or GDV that were examined and treated at the veterinary clinics returned to work. Of the 41 dogs where the gastric contents were recorded, 25 (61%) had predominantly food or bones in the stomach, and 26/27 dogs had a history of having eaten meat, bones or scavenged a carcass. The case-control study showed that the significant risk factors for GD or GDV, compared with control dogs presenting with trauma, were breed, age and season. The odds that a case of GD or GDV was a Huntaway, after adjusting for age and season, was 19 times higher than the odds a control was a Huntaway. Gender and bodyweight were not identified as risk factors. CONCLUSIONS AND CLINICAL RELEVANCE: A high proportion of farm working dogs with GD or GDV were successfully treated by veterinarians. The risk of a case of GD or GDV being a Huntaway was significantly higher than for a dog presenting as a trauma case. However the influences of the season of the year, climatic factors and nutritional factors on the pathogenesis need to be identified before adequate preventative measures can be recommended.

The clinical utility of MRI in patients with neurodevelopmental disorders of unknown origin.

INTRODUCTION: Neuroimaging of the brain in the diagnostic work-up of patients with neurodevelopmental disorders is a matter of continuing debate. Recommendations range from performing brain imaging in all patients with neurodevelopmental disorders to performing an MRI only in those with indication on clinical examinations. Important indications for neuroimaging are head size abnormalities and focal neurological findings. METHODS: Patients with neurodevelopmental disorders of unknown origin (n = 410), referred to a specialized tertiary diagnostic center for neurodevelopmental disorders were included in a retrospective analysis. A 1-day work-up, including an MRI of the brain was performed. Studied were the: (i) yield of MRI scans of the brain and (ii) associations of specific clinical symptoms/signs with abnormal and diagnostic MRI scans. RESULTS: (i) In 30.7% of the 410 patients with neurodevelopmental disorders (n = 126), abnormal MRI scans were observed, leading to an etiological diagnosis in 5.4% of the patients (n = 22). (ii) Pyramidal disorders (P = 0.001), epilepsy (P = 0.04) and an abnormal head circumference (P = 0.02) were associated with an abnormal MRI scan. The presence of one of the following neurological symptoms/signs: movement disorders, pyramidal disorders, epilepsy, or an abnormal head circumference was associated with a diagnostic MRI scan (P < 0.001) (diagnostic MRI % in neurological versus no neurological symptoms/signs, 13.0% versus 1.9%). CONCLUSION: Neuroimaging of the brain in a tertiary care center for patients with neurodevelopmental disorders of unknown origin is useful, especially in case of neurological symptoms/signs.

[Diagnostic image (230). A man with bilateral shoulder dislocation]. / Diagnose in beeld (230). Een man met bilaterale schouderluxatie.

A 28-year-old man suffered acute primary posterior dislocation of the left shoulder and anterior dislocation of the right one due to a motor accident.

Cow behaviour on a new grooved floor in comparison with a slatted floor, taking claw health and floor properties into account.

The objective of this study was to compare the behaviour of cows on a grooved floor with that of cows kept on a slatted floor. The trial was carried out with two groups of 12 Holstein-Friesian cows kept in a cowshed with two symmetrical halves, identical except for the floor. One floor was grooved longitudinally to the feeding fence (width of grooves 35mm) and the other was slatted (gaps 35mm wide) perpendicular to the feeding fence. Both floors had scrapers to remove manure. After 3 weeks of being kept on these two floors, cows were switched between floors for 3 weeks. In the third week of each 3-week-period, behavioural observations of cows related to their time budget over 24h, relocation on each floor indicated by index of movement and specific behaviours (aggression, self maintenance) performed on the floors were executed. The health of claws was examined before the trial and 6 weeks later, after the trial. The grooved floor influenced the cows' daily time budget: cows kept on the grooved floor stood less (P<0.05) with four legs inside the cubicles (group 1: 36min, group 2: 39min) than cows kept on the slatted floor (group 1: 57min, group 2: 60min). Neither the specific behaviours of cows nor their movement performed on both floors were different. After switching from the grooved floor to the slatted floor, cows lay for 669min a day (in comparison to 746min a day while kept on the grooved floor, P<0.05) and they stood parallel to the feeding fence for 174min a day (in comparison to 126min a day while kept on the grooved floor, P<0.05). Given that both groups of cows on the grooved floor and the group that began on the slatted floor had a similar daily time budget, it is possible that the different time budget of the remaining group, which started off on the grooved floor, was a reaction (pleasure or disappointment) induced by returning to the familiar floor. The grooved floor was more fouled with faeces (P<0.05) than the slatted floor. The grooved floor can be evaluated as being equal to the slatted floor with a scraper in terms of the behaviour performed on it. There were hardly any slip incidents on it (during 64h of observations, two slip incidents on the grooved floor, four slip incidents on the slatted floor). However, the occurrence of stumble incidents involving the manure scraper (66 cases on the grooved floor and 48 on the slatted floor during 64h of observations) and the occurrence of foot lesions (probably of traumatic origin) suggests that the functioning of the manure scraper, which is indispensable on grooved floors, needs to be optimised.

Fluorescent-labeled ligands for the benzodiazepine receptor. Part 1: Synthesis and characterization of fluorescent-labeled benzodiazepines.

Because radioactive labeled ligands in receptor assays have several disadvantages, we synthesized a number of fluorescent-labeled benzodiazepines. Several fluorophores were attached at different positions of 1,4-benzodiazepine molecules in order to assess the impact of the fluorophores and their coupling position on the affinity for the benzodiazepine receptor. Besides the 1,4-benzodiazepines, the 1,2-annelated 1,4-benzodiazepines were also used for labeling. A metabolite of flumazenil (18), desethylflumazenil (Ro15-3890, 19), was labeled with the fluorophore 4-bromomethyl-7-methoxycoumarin, with and without the incorporation of a spacer chain, yielding the methyl-methoxycoumarin (Mmc) derivatives Mmc-Ro15-3890 (20a) and Mmc-O-CO-(CH2)3-Ro15-3890 (20b), respectively. After the synthesis, the fluorescent-labeled benzodiazepines were purified by HPLC, using an analytical RP-C18 column. For the purification of 20b, the chromatographic system was optimized, using multi-criteria decision making (MCDM) techniques. The binding affinities for the benzodiazepine receptor and the fluorescence characteristics were determined for the resulting products.

Optimization of the reaction conditions for the synthesis of neoglycoprotein-AZT-monophosphate conjugates.

The coupling of the monophosphate derivative of 3-azido-2,3-dideoxythymidine (AZTMP) to glycoproteins by water soluble carbodiimide (1-ethyl-3-[3-(dimethylamino)propyl]-3-ethylcarbodiimide) was greatly improved, relative to a recently reported method, by using also N-hydroxysulfosuccinimide (NHS) in the conjugation reaction. The hydrolysis of the activated AZTMP intermediate, responsible for the low degree of conjugation in the earlier method, could be delayed considerably if the activated phosphate group was converted into an activated ester by addition of NHS. In order to minimize the use of compounds needed for the preparation of AZTMP-protein conjugates, the present study was undertaken to determine if the reaction conditions could be optimized such that a conjugate with 2 AZTMP molecules/mol of neoglycoprotein would result. In addition a low proportion of cross-linked conjugates was desired. Optimization was achieved studying the shape of three-dimensional response surfaces, in which the degree of AZTMP coupling and the percentage of monomeric conjugates were regarded as the relevant responses. It appeared that the optimal conditions for coupling 1-2 mol of AZTMP to 1 mol of glycoprotein were an incubation time of 30 h, an AZTMP amount of 4 mg, an NHS amount between 8 and 15 mg, and a glycoprotein amount of 50 mg.