The Evaluation of Leukocytes in Response to the In Vitro Testing of Ventricular Assist Devices

Infection is a clinically relevant adverse event in patients with ventricular assist device (VAD) support. The risk of infection could be linked to a reduced immune response resulting from damage to leukocytes during VAD support. The purpose of this study was to develop an understanding of leukocyte responses during the in vitro testing of VADs by analyzing the changes to their morphology and biochemistry. The VentrAssist implantable rotary blood pump (IRBP) and RotaFlow centrifugal pump (CP) were tested in vitro under constant hemodynamic conditions. Automated hematology analysis of samples collected regularly over 25‐h tests was undertaken. A new flow cytometric assay was employed to measure biochemical alteration, necrosis (7‐AAD) and morphological alteration (CD45 expression) of the circulating leukocytes during the pumping process. The results of hematology analysis show the total leukocyte number and subset counts decreased over the period of in vitro tests dependent on different blood pumps. The percentage of leukocytes damaged during 6‐h tests was 40.8 ± 5.7% for the VentrAssist IRBP, 17.6 ± 5.4% for the RotaFlow CP, and 2.7 ± 1.8% for the static control (all n = 5). Flow cytometric monitoring of CD45 expression and forward/side scatter characteristics revealed leukocytes that were fragmented into smaller pieces (microparticles). Scanning electron microscopy and imaging flow cytometry were used to confirm this. Device developers could use these robust cellular assays to gain a better understanding of leukocyte‐specific VAD performance.     

Comparison of two at-home whitening products of similar peroxide concentration and different delivery methods

PURPOSE : This study compared the whitening efficacy, side effects, and patients' preferences/perceptions of two whitening systems of similar peroxide concentration but different formulation and delivery methods. METHODS : The tooth color change of 24 participants was measured using a shade guide (BSG) and a spectrophotometer (ES). Color difference was calculated: ΔE* = [(ΔL*)(2) + (Δa*)(2) + (Δb*)(2)](1/2). One whitening treatment was randomly applied to the right or left maxillary anterior teeth and the other was applied to the contralateral teeth, at-home with 35% carbamide peroxide in a tray (TW) or with 14% hydrogen peroxide in strips (WS). The tooth color was evaluated at baseline, 15 and 30 days (15 days postwhitening). Participants rated their tooth and soft tissue sensitivity (1-10 scale) and completed a questionnaire on their preferences. Results were analyzed by repeated measurement regression analysis/Tukey and Mann-Whitney (p<0.05). RESULTS : At 15 days, the teeth treated with TW and WS presented ΔE* = 7 and 6, respectively (ΔBSG=3 for both), and at 30 days, they presented ΔE* = 7.5 and 6.5, respectively (ΔBSG=3 for both). There was no significant difference in tooth and soft tissue sensitivity between treatments. No participant reported tooth and gingival sensitivity at the postwhitening appointment. Of the participants, 83% preferred the TW over WS. CONCLUSION : Both ΔE* and ΔBSG showed no significant difference in tooth color change between TW and SW at either time point. By the end of the study no participants reported tooth and gingival sensitivity. Participants preferred TW over SW.     

Non-invasive methods for iron overload evaluation in dysmetabolic patients

IntroductionAlthough hyperferritinemia may reflect the inflammatory status of patients with non-alcoholic fatty liver disease (NAFLD), approximately 33% of hyperferritinemia cases reflect real hepatic iron overload.AimTo evaluate a non-invasive method for assessing mild iron overload in patients with NAFLD using 3T magnetic resonance imaging (MRI) relaxometry, serum hepcidin, and the expression of ferritin subunits.MethodsThis cross-sectional study assessed patients with biopsy-proven NAFLD. MRI relaxometry was performed using a 3T scanner in all patients, and the results were compared with iron content determined by liver biopsy. Ferritin, hepcidin, and ferritin subunits were assessed and classified according to ferritin levels and to siderosis identified by liver biopsy.ResultsA total of 67 patients with NAFLD were included in the study. MRI revealed mild iron overload in all patients (sensitivity, 73.5%; specificity, 70%). For mild (grade 1) siderosis, the transverse relaxation rate (R₂*) threshold was 58.9 s^?1 and the mean value was 72.5 s^?1 (SD, 33.9), while for grades 2/3 it was 88.2 s^?1 (SD, 31.9) (p < 0.001). The hepcidin threshold for siderosis was > 30.2 ng/mL (sensitivity, 87%; specificity, 82%). Ferritin H and ferritin L subunits were expressed similarly in patients with NAFLD, regardless of siderosis. There were no significant differences in laboratory test results between the groups, including glucose parameters and liver function tests.ConclusionsMRI relaxometry and serum hepcidin accurately assessed mild iron overload in patients with dysmetabolic iron overload syndrome.     

Estimation of fruit and vegetable intake using a two-item dietary questionnaire: a potential tool for primary health care workers

BACKGROUND AND AIM: High fruit and vegetable intake is associated with health benefits for cancer and cardiovascular disease. An increase is therefore integral in recommendations for the prevention of chronic disease. However, measuring intake requires either extensive dietary assessment or the measurement of specific bio-markers which is neither cheap nor feasible for the routine assessment of an individual's diet in a community or primary care setting. Within the context of a study evaluating a dietary counselling programme to increase fruit and vegetable intake our aim was to assess the use of a simple tool to estimate fruit and vegetable intake. METHODS AND RESULTS: We studied associations between bio-markers [plasma ascorbic acid, beta-carotene and alpha-tocopherol 24-hour urinary potassium excretion] and a two-item fruit and vegetable consumption questionnaire in 271 subjects (105 men and 166 women), aged 18 to 70 years. After controlling for age, sex, vitamin supplement use, smoking and body mass, those reporting a daily intake of > or = 5 portions of fruit and vegetables had higher potassium excretion (difference 15.6 [95% confidence interval: 6.2 to 25.0] mmol/24 h), urinary potassium/creatinine ratio (1.2 [0.5 to 2.0]) and plasma vitamin C (10.0 [-0.9 to 20.8] mumol/L) than those reporting < or = 2.5 portions per day. beta-carotene (p = 0.04), vitamin C (p = 0.01) and potassium excretion (p < 0.001) were associated with fruit rather than vegetable intake. The two-item questionnaire had high specificity; over 3/4 of participants who reported low intake also had bio-markers below the upper third of the distribution. CONCLUSION: Self report of fruit and vegetable intake through a simple questionnaire is confirmed by bio-markers for those eating less than five portions of fruit and vegetables a day. Although the tool is amenable to improvements for the detection of vegetable portions, it may prove useful for monitoring dietary preventive approaches in primary care without the use of invasive and costly biochemical measurements.