Relaxation Response in Stressed Volunteers: Psychometric Tests and Neurotrophin Changes in Biological Fluids.

Background: To evaluate the beneficial effects of relaxation response (RR) training in adult stressed subjects by evaluating the psychometric response recorded at relaxation session. Cortisol as well as nerve growth factor (NGF) and brain derived neurotrophic factor (BDNF) mediators were quantified in both saliva and tears, and their levels were related to each other and to the psychometric response. Methods: Stressed subjects (n = 23; 10M/13F; age range 21-53 years old) were voluntarily enrolled in the study. RR training sessions were carried out for 2 months, 1 day per week, at the same time (3-5 p.m.). Two different psychological questionnaires, the Perceived Stress Scale-10 (PSS-10) and the Beck Depression Inventory - Short Form (BDI-SF) and Ocular Surface Disease Index (OSDI) tests, were administered before each session. Saliva and tears were sampled for cortisol (EIA), NGF (ELISA), and BDNF (ELISA) quantifications. Questionnaires' data were analyzed and compared to biochemical ones. Results: All subjects reported beneficial effects from training. RR significantly reduced the psychological stress indexes (p = 0.039 for PSS-10 and p = 0.001 for BDI-SF). Specifically, RR training lowered the perception of Perceived Helplessness (items 1, 3, 10; p < 0.05) in PSS-10 and increased the Perceived Self-Efficacy (p < 0.05). OSDI score was in the normal range (0-25). Biochemically, a decrease in cortisol, a trend to a decrease in NGF, and an increase in BDNF levels were observed in saliva samples after RR treatment. Furthermore, a trend to a decrease in NGF and an increase in BDNF were quantified in tear samples. A correlation between PSS-10 total score and saliva NGF variation (%) as well as between BDI-SF total score and BDNF tear levels were also observed. Conclusion: RR training appeared useful to lowering psychological, mental, and physical stress, as supported by both psychological total and single scores. The finding on biochemical levels of BDNF in saliva and tears are sustained by previous studies while those of NGF require further investigation. Overall, these data on a small population highlight the potential use of RR training and potential neurotrophic changes in biological fluids, in stressed volunteers.

The Hemo One Autoanalyzer for Glycated Hemoglobin Assay.

BACKGROUND: Glycated hemoglobin (HbA1c) is widely used as a clinical marker of long-term blood glucose concentration in patients with diabetes. The clinical laboratory plays a vital role in the diagnosis and management of diabetes. Many methods for the measurement of HbA1c have been developed based on different analytical principles, often causing discordant results. For this reason, the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) established a reference method for HbA1c assay, namely, high-performance liquid chromatography-mass spectrometry/capillary electrophoresis (HPLC-MS/CE). OBJECTIVE: In order to evaluate in parallel 2 different routine methods, namely, ion-exchange HPLC and immunoturbidimetry. METHODS: For our comparison study, we used the Tosoh G8 HPLC analyzer and the Hemo One autoanalyzer system to test 100 blood specimens for HbA1c concentration, the values of which ranged from 4.3% (23.5 mmol/mol) to 14.7% (137 mmol/mol). RESULTS: Concordance between HPLC and the immunoturbidimetric method revealed perfect agreement with a Kappa value of 0.828. CONCLUSIONS: Our results confirm the validity of the immunoturbidimetric method compared with the reference method. Our findings highlight that these 2 methods are equivalent for the diagnosis and therapeutic monitoring of diabetes.

Description of an Automated Method for Urea Nitrogen Determination in Bronchoalveolar Lavage Fluid (BALF) of Neonates and Infants.

Bronchoalveolar lavage (BAL) partially recovers both the instilled saline and the alveolar fluid, so-called epithelial lining fluid (ELF), but a correction for the dilution due to the BAL technique itself is needed to know the amount of recovered ELF. In this regard, urea nitrogen may be useful and has been proposed to calculate ELF. The aim of the present study was to develop and validate a new method to measure urea nitrogen in BAL fluid (BALF). We used 19 BALF samples obtained from neonates and infants with different respiratory conditions. The urea nitrogen assay was carried out on Cobas c311 analyzer (Roche Diagnostics). A validation study shows that the method is perfectly linear (R(2) = 0.999), sensitive (limit of detection = 0.055 mg/dL; limit of quantification = 0.16 mg/dL), repeatable (low = 0.15 ± 0.02, 13.3%; high = 1.80 ± 0.02, 1.1%), reproducible (low = 0.14 ± 0.02, 14.2 %; high = 1.76 ± 0.04, 2.2 %) with accuracy ranging between 93-96%. Our results support the robustness of validated procedure since the described method appears simple, precise, rapid, and suitable for routine analysis. Thus, it may be used to correct concentration of various noncellular BAL components and calculate their ELF amounts in neonates and infants.