Evaluation of High Performance Liquid Chromatography and Liquid Chromatography-Tandem Mass Spectrometry Methods for 25 (OH) D3 Assay.

BACKGROUND: This study was designed to compare the performances of HPLC (High Performance Liquid Chromatography) and LC-MS/MS (Liquid Chromatography-Tandem Mass Spectrometry) methods in 25 (OH) D3 testing. METHODS: This study is comprised of 306 randomly chosen plasma samples from the subjects who applied for routine measurement of 25 (OH) D3. Plasma 25 (OH) D3 levels were quantified using HPLC and LC-MS/MS. The LC-MS/MS method was used as the reference method. The linearity, precision, carry-over, limit of blank, limit of detection (LoD), and comparison studies were done for method validation. Accuracy was tested using external quality assurance samples. RESULTS: Coefficients of variation for both methods were at around 10.0%. The HPLC and LC-MS/MS assays were linear over the working range from 5.0 to 100 ng/mL (r > 0.99). The HPLC assay showed a higher LoD compared to LC-MS/MS (5.1 vs. 1.6 ng/mL, respectively). Results from external quality assurance samples were within ? 1 SD range for both methods. The comparison study revealed good correlation between HPLC and LC-MS/MS methods (y = 1.054x - 1.981 with a small mean bias (-0.953) (r = 0.9752)), when all samples were included, regardless of their 25 (OH) D3 levels. However, the correlation was poor for samples with 25 (OH) D3 concentrations lower than 10 ng/mL. CONCLUSIONS: Both methods have acceptable performance characteristics for use in clinical diagnostic applications. A good comparability was obtained between HPLC and LC-MS/MS methods. However, LoD of HPLC assay was higher and there was a poor correlation between the two systems for samples with 25 (OH) D3 concentrations below 10 ng/mL, showing that LC-MS/MS system is more successful in measuring samples with low 25 (OH) D3 concentration.

Is the increased ozone dosage key factor for its anti-inflammatory effect in an experimental model of mesenteric ischemia?

BACKGROUND: Ischemia/reperfusion injury of the intestines is a severe surgical condition. This study aimed to reveal ozone therapy effects with relatively increased ozone dosage in a created ischemia/reperfusion injury model. METHODS: In this study, 24 albino Wistar rats were examined in three groups. Rats in the control group (CG, n=8) underwent only a laparotomy. In the sham group (SG, n=8) and ozone group (OG, n=8), the superior mesenteric artery (SMA) of the rats was occluded for 1 h. After deoccluding the SMA, the abdomen was closed, physiological saline was infused intraperitoneally in the SG, and an increased ozone/oxygen mixture dose (from 0.7 mg/kg to 1 mg/kg) was infused intraperitoneally in the OG. Small intestine samples were obtained at the 24th h for histopathological examination of intestinal mucosal injury and evaluated according to the Chiu score. In addition, Malondialdehyde and Myeloperoxidase levels were evaluated for oxidant levels, whereas, Glutathione (GSH) enzyme activity was measured to evaluate the tissue antioxidant system. RESULTS: Histopathologically, the Chiu score was the lowest in the CG. It was lower in the OG compared to the SG showing the ameliorating effect of ozone on the intestinal mucosa. Chiu score in the OG was higher compared to that in the CG, but not statistically significant. A significantly higher GSH level was observed in the OG compared to the SG, proving antioxidant activity. CONCLUSION: In this experimental model of ischemia/reperfusion in rats, treatment with an increased ozone level decreased the inflammatory process through antioxidant mechanisms and reduced intestinal mucosal damage. However, the effectiveness of ozone therapy depends on its dosages.

A new haematocytometric index: Predicting severity and mortality risk value in COVID-19 patients.

INTRODUCTION: Coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 virus, is a major public health concern spanning from healthy carriers to patients with life-threatening conditions. Although most of COVID-19 patients have mild-to-moderate clinical symptoms, some patients have severe pneumonia leading to death. Therefore, the early prediction of disease prognosis and severity is crucial in COVID-19 patients. The main objective of this study is to evaluate the haemocytometric parameters and identify severity score associated with SARS-CoV-2 infection. METHODS: Clinical and laboratory records were retrospectively reviewed from 97 cases of COVID-19 admitted to hospitals in Istanbul, Turkey. The patient groups were subdivided into three major groups: Group 1 (Non-critical): 59 patients, Group 2 (Critical-Survivors): 23 patients and Group 3 (Critical-Non-survivors):15 patients. These data was tested for correlation, including with derived haemocytometric parameters. The blood analyses were performed the Sysmex XN-series automated hematology analyser using standard laboratory protocols. All statistical testing was undertaken using Analyse-it software. RESULTS: 97 patients with COVID-19 disease and 935 sequential complete blood count (CBC-Diff) measurements (days 0-30) were included in the final analyses. Multivariate analysis demonstrated that red cell distribution width (RDW) (>13.7), neutrophil to lymphocyte ratio (NLR) (4.4), Hemoglobin (Hgb) (<11.4 gr/dL) and monocyte to neutrophil ratio (MNR) (0.084) had the highest area under curve (AUC) values, respectively in discrimination critical patients than non-critical patients. In determining Group 3, MNR (<0.095), NLR (>5.2), Plateletcount (PLT) (>142 x103/L) and RDW (>14) were important haemocytometric parameters, and the mortality risk value created by their combination had the highest AUC value (AUC = 0.911, 95% CI, 0886-0.931). Trend analysis of CBC-Diff parameters over 30 days of hospitalization, NLR on day 2, MNR on day 4, RDW on day 6 and PLT on day 7 of admission were found to be the best time related parameters in discrimination non-critical (mild-moderate) patient group from critical (severe and non-survivor) patient group. CONCLUSION: NLR is a strong predictor for the prognosis for severe COVID-19 patients when the cut-off chosen was 4.4, the combined mortality risk factor COVID-19 disease generated from RDW-CV, NLR, MNR and PLT is best as a mortality haematocytometric index.