ABSTRACT
OBJECTIVES: This study assessed the effect of vitamin B6 status on immune responses in mechanically ventilated, critically ill patients and compared the results with those of healthy controls. METHODS: This was designed as a cross-sectional observational study. Forty patients in the intensive care unit successfully completed this study. Vitamin B6 intake was recorded for 8 d. Severity of illness (Second Acute Physiology and Chronic Health Evaluation score) was recorded. Thirty-eighty healthy controls were recruited from the physical check unit of Taichung Veterans General Hospital (Taichung, Taiwan). All control subjects were given instruction on how to complete a 24-d diet recall. Vitamin B6 status was assessed by direct measures (plasma pyridoxal 5'-phosphate [PLP] and 4-pyridoxic acid) and indirect measures (erythrocyte alanine and aspartate aminotransferase activity coefficients). Levels of serum albumin, hemoglobin, hematocrit, high-sensitivity C-reactive protein, and immune responses (white blood cell, neutrophil, total lymphocytes, T lymphocytes [CD3], B lymphocytes [CD19], T-helper cells [CD4], and suppressor cells [CD8]) were determined. RESULTS: Critically ill patients had sufficient vitamin B6 intake but showed marginal PLP deficiency (20.9 +/- 1.5 nmol/L). In addition, critically ill patients had significantly lower and abnormal immune responses than did healthy controls. There was no significant correlation of vitamin B6 intake and erythrocyte alanine and aspartate aminotransaminase activity coefficients with immune indices. Plasma PLP concentration was strongly negatively correlated with high-sensitivity C-reactive protein level. However, plasma PLP was significantly associated with immune responses after adjustment for age, sex, high-sensitivity C-reactive protein, and the other four vitamin B6 indicators. CONCLUSIONS: Plasma PLP is a significant indicator of immune responses in human subjects. Further research is warranted to study whether vitamin B6 supplementation in critically ill patients improves their immune responses.
Subject(s)
Critical Illness , Pyridoxal Phosphate/blood , Pyridoxal Phosphate/deficiency , Respiration, Artificial , Vitamin B 6 Deficiency/immunology , Vitamin B 6/administration & dosage , APACHE , Adult , Aged , Aged, 80 and over , Alanine Transaminase/metabolism , Aspartate Aminotransferases/metabolism , C-Reactive Protein , Case-Control Studies , Critical Illness/therapy , Cross-Sectional Studies , Erythrocytes/enzymology , Female , Health Status Indicators , Hospitalization , Humans , Lymphocytes/blood , Male , Mental Recall , Middle Aged , Nutritional Status , Pyridoxal Phosphate/immunology , Severity of Illness Index , Vitamin B 6/analogs & derivatives , Vitamin B 6 Deficiency/bloodABSTRACT
NiTi orthodontic wire products from different manufacturers would have different corrosion resistance. We assayed the corrosion resistance, in terms of ion release, of different NiTi orthodontic wires in artificial saliva with various acidities. Four types of as-received commercial NiTi orthodontic wires were immersed in artificial saliva (37 degrees C) at pH 2.5-6.25 for different periods (1-28d). The amount of Ni and Ti ions released from NiTi wires was determined using an atomic adsorption spectrophotometer. Surface morphology and roughness of wires were related to the corrosion resistance. Results showed that the manufacturer, pH value, and immersion period, respectively, had a significantly statistical influence on the release amount of Ni and Ti ions. The amount of Ni ions released in all test solutions was well below the critical value necessary to induce allergy and below daily dietary intake level. The amount of Ti ions released in pH>/=3.75 solution was mostly not detectable, representing that the TiO(2) film on NiTi wires exhibited a good protection against corrosion. Pre-existed surface defects on NiTi wires might be the preferred locations for corrosion. The NiTi wire with the highest release amount of metal ions had the maximal increase in surface roughness after immersion test, while a rougher surface did not correspond to a higher metal ion release.
