Problematic rise of vitamin B6 supplementation overuse and potential risk to bariatric surgery patients.

OBJECTIVES: Due to the increased prevalence of obesity in the world, bariatric surgeries are on the rise and necessitate life-long surveillance for deficiencies; hence the recommended vitamin supplementation in these patients. However, inadequate multivitamin supplementation may induce vitamin B6 overload. METHODS: We reviewed all vitamin B6 dosages at the university hospitals of Poitiers, Tours, Bordeaux, and Limoges for the past 5 to 8 years. Analyses were performed by high-performance liquid chromatography, coupled with a fluorescence detector on whole blood samples. RESULTS: During the study period, there was an increase in the number of vitamin B6 dosages. Deficiencies were detected early in Poitiers and Limoges, but were negligible by 2020. However, during the same time period, the number of overdoses increased, reaching close to 40% of dosages at all centers. CONCLUSIONS: Pyridoxin overload is not possible through food-derived pyridoxin; hence, combined with the fact that most vitamin supplements contain vitamin B6, inadequate vitamin supplementation is likely the cause of the observed increase in overdoses. High doses of vitamin B6 can induce polyneuropathy, particularly targeting motor neurons; thus, the increase of overdoses is worrying. In light of the possible risks and the ease with which these could be averted (better formulation of supplements), the precaution principle requires a definition of clear guidelines for vitamin supplementation, especially in patients undergoing bariatric surgery.

Comparison of the removal of uraemic toxins with medium cut-off and high-flux dialysers: a randomized clinical trial.

BACKGROUND: Accumulation of middle-weight uraemic toxins in haemodialysis (HD) patients results in increased morbidity and mortality. Whether medium cut-off HD (MCO-HD) improves removal of middle-weight uraemic toxins remains to be demonstrated. METHODS: This cross-over prospective study included 40 patients randomly assigned to receive either 3 months of MCO-HD followed by 3 months of high-flux HD (HF-HD), or vice versa. The primary endpoint was myoglobin reduction ratio (RR) after 3 months of MCO-HD. Secondary endpoints were the effect of MCO-HD on other middle-weight toxins and protein-bound toxins, and on parameters of nutrition, inflammation, anaemia and oxidative stress. RESULTS: Compared with HF-HD, MCO-HD provided higher mean RR of myoglobin (36 ± 8 versus 57 ± 13%, P < 0.0001), beta2-microglobulin (68 ± 6 versus 73 ± 15%, P = 0.04), prolactin (32 ± 13 versus 59 ± 11%, P < 0.0001), fibroblast growth factor 23 (20 ± 21 versus 41 ± 22%, P = 0.0002), homocysteine (43 ± 7 versus 46 ± 9%, P = 0.03) and higher median RR of kappa [54 (48-58) versus 70 (63-74)%, P < 0.0001] and lambda free light chain (FLC) [15 (9-22) versus 44 (38-49)%, P < 0.0001]. Mean ± SD pre-dialysis levels of beta2-microglobulin (28.4 ± 5.6 versus 26.9 ± 5.1 mg/L, P = 0.01) and oxidized low-density lipoprote (6.9 ± 4.4 versus 5.5 ± 2.5 pg/mL, P = 0.04), and median (interquartile range) kappa FLC [145 (104-203) versus 129 (109-190) mg/L, P < 0.03] and lambda FLC [106 (77-132) versus 89 (62-125) mg/L, P = 0.002] were significantly lower. Mean albumin levels decreased significantly (38.2 ± 4.1 versus 36.9 ± 4.3 g/L, P = 0.004), without an effect on nutritional status as suggested by unchanged normalized protein catabolic rate and transthyretin level. CONCLUSIONS: Compared with HF-HD, MCO-HD provides higher myoglobin and other middle molecules RR and is associated with moderate hypoalbuminemia. The potential benefits of this strategy on long-term clinical outcomes deserve further evaluation.

[False paraprotein-induced hypoglycemia in the measurement of glucose by the hexokinase method]. / Fausse hypoglycémie induite par les paraprotéines lors de la mesure du glucose par la méthode de l'hexokinase.

A 67 years old woman with a Waldenström disease was admitted in the intensive care unit for dyspnea and fever. During hospitalization, episodes of undetectable glycemia were observed without any hypoglycemia symptoms. Plasma glucose was determined with the hexokinase method (recommended). From this observation, a literature review on PubMed was performed to investigate similar cases. In patients with protides in excess (e.g. immunoproliferative syndrome), absorption measurements could be disrupted by the precipitation of excess protein (IgM in most cases). Other parameters could be affected: bilirubin, phosphate, HDL cholesterol, GGT, CRP and calcemia. In our case, the main difficulty was to identify the cause of the interference and then correct it. Using a series of dilution, we prevented protide precipitation allowing correct glucose determination. Those interferences are rare, but present a real analytical difficulty. Biologists should be aware of those interferences because of dramatics consequences.

Vectisol Formulation Enhances Solubility of Resveratrol and Brings Its Benefits to Kidney Transplantation in a Preclinical Porcine Model.

Current organ shortages have led centers to extend the acceptance criteria for organs, increasing the risk for adverse outcomes. Current preservation protocols have not been adapted so as to efficiently protect these organs. Herein, we target oxidative stress, the key mechanism of ischemia reperfusion injury. Vectisol® is a novel antioxidant strategy based on the encapsulation of resveratrol into a cyclodextrin, increasing its bioavailability. We tested this compound as an additive to the most popular static preservation solutions and machine perfusion (LifePort) in a preclinical pig model of kidney autotransplantation. In regard to static preservation, supplementation improved glomerular filtration and proximal tubular function early recovery. Extended follow-up confirmed the higher level of protection, slowing chronic loss of function (creatininemia and proteinuria) and the onset of histological lesions. Regarding machine perfusion, the use of Vectisol® decreased oxidative stress and apoptosis at the onset of reperfusion (30 min post declamping). Improved quality was confirmed with decreased early levels of circulating SOD (Superoxide Dismutase) and ASAT (asparagine amino transferase). Supplementation slowed the onset of chronic loss of function, as well as interstitial fibrosis and tubular atrophy. The simple addition of Vectisol® to the preservation solution significantly improved the performance of organ preservation, with long-term effects on the outcome. This strategy is thus a key player for future multi-drug therapy aimed at ischemia reperfusion in transplantation.

Planktonic free-living amoebae susceptibility to dental unit waterlines disinfectants.

A high diversity of microorganisms is encountered inside dental unit waterlines (DUWL). Among those the presence of free-living amoebae (FLA) appears currently underestimated, although human infections may occur due to contact with FLA-contaminated water during dental cares. In order to limit microbial DUWL contamination, disinfectants are provided by dental unit manufacturer, however, with limited documentation on their activities against FLA. The aim of this study was to evaluate the efficiency of three commercial DUWL disinfectants: the Calbenium© (Airel, Champigny-sur-Marne, France), the Oxygenal 6© (Kavo, Biberach, Germany) and the Sterispray© (Gammasonic, Billom, France), against two FLA species, i.e. Acanthamoeba castellanii and Vermamoeba vermiformis alone or co-cultured with Pseudomonas aeruginosa and Candida albicans at concentrations ranging from 0% to 5% (v/v). Results showed varied efficacies of disinfectants: the Oxygenal 6© did not exhibit FLA killing activity, while the Sterispray© and the Calbenium© displayed concentration- and species-dependent activities with a maximum eradication rates of 100% and 86%, and 79% and 97% for A. castellani and V. vermiformis, respectively. None of the disinfectants were able to totally eradicate FLA at concentrations recommended by manufacturers. Present results highlight unsatisfactory anti-FLA activities of 3 DUWL disinfectant preparations advocating deeper investigation of antimicrobial spectra of commercial disinfectants in use for DUWL maintenance.