Validation of a novel automated system, Fluispotter®, for serial sampling of dried blood spots.

Repeated blood sampling is required in certain clinical and research settings, which is currently performed by drawing blood from venous catheters requiring manual handling of each sample at the time of collection. A novel body-worn device for repeated serial samples, Fluispotter®, with automated extraction, collection, and storage of up to 20 venous dried blood spot samples over the course of 20 h may overcome problems with current methods for serial sampling. The purpose of this study was to assess the performance and safety of Fluispotter for the first time in healthy subjects. Fluispotter consists of a cartridge with tubing, a reservoir for flushing solution, pumps and filterpaper, and a multi-lumen catheter placed in the brachial vein. We recruited healthy subjects for testing in an in-hospital setting. Fluispotter was attached by an anesthesiologist to 22 healthy subjects of which 9/22 (40.9%) participants had all 20 samples taken, which was lower than the goal of complete sampling in 80% of the subjects (P = 0.02). The main reason for sample failure was clogging of blood flow which was observed in 11/22 (50%) of the participants. No serious adverse events occurred, and the participants rated the pain from the insertion and the removal of catheter as very low. A cortisol profile showed nadir values at midnight and highest values at 05:00 h. Although full sampling was not successful in all participants, the Fluispotter technology proved safe and highly acceptable to the participants producing the expected cortisol profile without the requirement of staff during sample collection.

A novel device for serial venous blood sampling in a canine model.

Diagnostic serial venous blood sampling has the potential to introduce stress-related artifactual elements into the analytical results. We have evaluated the use of a wearable automated serial blood sampling device in a canine model that obviates a need for multiple manual venipuncture. Efficacy in measuring cortisol levels during prolonged serial blood sampling is described. Automated serial blood sampling from the jugular vein was performed in two Beagle dogs. Over two separate 22-h periods, serial blood samples were withdrawn for routine cell counting and blood chemistries from each animal, whilst animal behavior along with durability of catheter placement and tolerability by the vascular system were assessed. During the study, no behavioral changes attributed to the serial blood sampling device were seen and no stress-related deviations from normal blood cell counts and cortisol levels were detected. Minor erythema was eident at the sites of catheter placement, which was consistent with the presence of an indwelling catheter. The wearable, serial blood sampling device performed well and was tolerated by the animals without stress-related changes in blood analysis or behavioral observation. This study has demonstrated the potential significant benefit of the Fluispotter® device for serial blood sampling in veterinary and clinical settings. The samples collected are free from stress-related signatures in blood chemistry otherwise common to serial blood sampling protocols requiring repeated venipuncture. This device has valuable implications for use in routine preclinical pharmacology and toxicology studies.

Fluispotter, a novel automated and wearable device for accurate volume serial dried blood spot sampling.

Aim: A novel automated serial dried blood spot (DBS) sampler, 'Fluispotter', was tested for its sampling performance. Materials & methods: An LC-MS/MS method was developed for the analysis of cortisol in DBS samples serially spotted by Fluispotter. The cortisol concentrations in 148 paired DBS and plasma samples were compared across a hematocrit (HCT) range of 22-55%. Results: The interassay accuracy and precision were <10%. Overall assay bias was negligible across the HCTs tested when analyzing the whole-spot DBS samples. The accuracy and precision of the blood volume in 10 µl DBS samples spotted by Fluispotters and micropipettes were within 3%. Deming regression and Bland-Altman analysis showed a good agreement of DBS-predicted and measured plasma cortisol. Conclusion: The Fluispotter performed serial sampling with high accuracy and precision of the sample blood volume.

The influence of diet consistence, drinking water and bedding on periodontal disease in Sprague-Dawley rats.

BACKGROUND: Although rats have been extensively used in periodontal research, pre-experimental periodontal inspection has not been given high priority in previous studies of experimental periodontal disease in rats. An inspection of 50 Sprague-Dawley rats, which were to be used in a model of experimental periodontal disease, revealed signs of periodontal disease in a considerable proportion of the animals. OBJECTIVES: The objectives of the present study were to describe disease progression, identify factors responsible for induction of periodontal disease and test a method for breeding of healthy rats. METHODS AND RESULTS: A longitudinal study revealed that 33% of rats, bred under the same conditions, showed signs of periodontal disease during, or shortly after, eruption of the molars. Regular diet caused significantly more horizontal bone loss (P = 0.0001) and significantly less periodontal bone support (P < 0.0001) than the same kind of diet with a smaller grain size. Wood chip bedding in the rats' cages significantly reduced periodontal bone support (P < 0.0001) compared to a wire mesh floor and a simultaneous use of regular diet and bedding decreased it even further (P = 0.0023). Finally, by using finely milled diet, a wire mesh floor and tap water, instead of conventional breeding methods of regular diet, bedding and acidic water, it was possible to breed rats with minimal signs of periodontal disease. CONCLUSIONS: The results of the present study emphasize the need for pre- experimental examination of rats. They also show that diet and bedding conditions have the potential of seriously influencing outcomes of studies of periodontal disease in rats.

Assessment of the postoperative discomfort of intra-auricularly hypophysectomized rats.

Rats subjected to hypophysectomy make up one of the largest groups of experimental animals in Europe, since there is a legal demand for batch testing of industrially produced growth hormones. To describe the clinical performance of rats having undergone hypophysectomy, animals were examined postoperatively by monitoring behaviour, body temperature and food intake. Behavioural changes were observed in rats that had only been anaesthetized, as well as in sham-operated rats, while no behavioural deviations could be shown in hypophysectomized rats. On the first day after surgery all rats had declining body temperature and food intake; and this change was not reversed by treatment with carprofen, buprenorphine or oxytetracycline. The mortality rate in rats treated with buprenorphine was increased, as was the mortality rate in rats hypophysectomized when weighing more than 100 g. As there seemed to be no differences whether methohexital or a combination of fentanyl, fluanison and midazolam was used, the latter anaesthesia is recommended due to its analgesic potential. For post-surgical analgesic treatment, carprofen is recommended rather than buprenorphine. At best, the use of hypophysectomized rats should be replaced in industrial batch testing by an existing in vitro method.