Background: Recent reports have described inherent problems with androgen immunoassays compared with mass spectrometry analyses. In this study, a new liquid chromatography- tandem mass spectrometry (LC-MS/MS) method was developed according to CLSI rules. The developed method was compared with two immunoassay methods, the enzyme-linked immunosorbent assay (ELISA) and radioimmunoassay (RIA). Methods: After liquid-liquid extraction, a Shimadzu Prominence LC unit coupled to an ABSCIEX API 3200 mass spectrometer with atmospheric pressure chemical ionization was used to quantify serum androstenedione levels. Serum androstenedione results taken from tandem mass spectrometry were compared with the immunoassays. Results: The androstenedione assay was linear up to 50 ng/mL. Lower limit of quantitation and lower limit of detection were 0.195 ng/mL and 0.097 ng/mL, respectively. This method was not affected by matrix effect and other steroid hormone interferences. In this study, the obtained recovery was 69 - 99%, carryover value was determined as 0.026 ng/mL. According to the results of an interference study, androstenedione bias % did not exceed the limit of allowable bias % and 88.7% recovery was acquired for androstenedione. In the LC-MS/MS and ELISA comparison study, the slope value was found as 18.412, intercept -22.87, and r(2) value as 0.1033. In the LC-MS/MS and RIA comparison study, slope value was found as 1.085, intercept 0.4541, and r(2) value as 0.3712. In the RIA and ELISA comparison study, slope value was found as 9.57, intercept -15.5, and r(2) value as 0.19. Conclusions: The LC-MS/MS provides agreement with the results of radioimmunoassay but not with ELISA. This method offers better selectivity compared to immunoassay systems.

Objectives: In this study, it was aimed to evaluate the hypoxia-inducible factor-1α (HIF-1α) and ischemia-modified albumin (IMA) levels of patients diagnosed with COVID-19 in the intensive care unit (ICU) and healthy controls. To our knowledge, this is the first study investigate HIF-1α and IMA levels in COVID-19 patients in ICUs and comparing them with a healthy control group. For this reason, our study is original and will contribute to the literature. Methods: A total of 70 intensive care patients diagnosed with COVID-19, and 72 healthy controls were included in the study. Results: When we compared the patient and healthy control group; there were no statistically significant differences between the groups in terms of age and gender (p>0.05). No exitus was observed in the patient group. We found weak correlation between HIF-1α and IMA (r: 0.320). However, there were statistically significant differences in HIF-1α and IMA levels in the patient group. The receiver operating characteristic (ROC) curve demonstrated an area under curve (AUC) value of 0.651 for HIF-1α and 0.937 for IMA. Conclusions: The HIF-1α and IMA levels were significantly higher among COVID-19 patients in ICU compared with healthy controls. HIF-1α and IMA levels can be used as reliable markers for the prognosis of COVID-19.

Objectives: This study aimed to evaluate the calcium/magnesium (Ca/Mg) ratio in patients diagnosed with type 2 diabetes mellitus (T2DM). Methods: This study is a retrospective cross-sectional study. Mg levels were determined by measuring the total serum Mg levels. Magnesium was measured by colorimetric method and HbA _1c was measured by turbidimetric inhibition immunoassay method. Subject were divided into two groups (<7 % and ≥7 %) based on HbA _1c levels. Also, subjects were divided into four groups (quartiles) based on serum Mg concentrations. Results: A total of 891 (636F, 255M) patients diagnosed with T2DM were included in the study. The Mg increase in the group with good glycemic control was also remarkable. One of our most important findings is that as the Mg concentration increases, the fasting glucose, HbA _1c , and Ca/Mg rate decreased with increasing Mg concentration. In the ROC analysis performed between the poor and good glycemic control groups, we found the AUC was 0.672, 0.650, 0.611, and 0.578 for Ca/Mg ratio, Mg, K, and Ca, respectively. Conclusions: While the Ca/Mg ratio and Ca levels were significantly higher, Mg levels were significantly lower among poor glycemic control than good glycemic control T2DM. The Ca/mg ratio and Mg are important parameters for T2DM patients, but more comprehensive studies are needed before they can monitor glycemic control.

Among the most common causes of nasal congestion in childhood is adenoid hypertrophy (AH) which leads to hypoxia. In this study, we studied plasma concentrations of hypoxia induced factor-1α (HIF-1α) in children undergoing adenoidectomy. The study included a total of 86 participants: 39 patients with AH and 47 healthy individuals. Serum HIF-1α levels (ng/mL) were measured by ELISA. HIF-1α concentrations were compared to the adenoid-nasopharyngeal ratio (ANR) of patients with AH, as recorded in the medical records. We found significantly higher concentrations of HIF-1α (0.30 ± 0.47 ng/mL) in patients with AH as compared to healthy controls (0.24 ± 0.07 ng/mL, p = .011). HIF-1α levels were not significantly different regarding gender between patients with AH (p = .77) and in the control group (p = .97). In patients with AH, there was a moderately significant positive correlation between HIF-1α levels and Hb (p = .000), (correlation coefficient r = 0.542). There was a positive correlation between HIF-1α and ANR in patients with AH (p = .005, r = 0.439). This study indicates that AH increases HIF-1α levels. We also observed a moderately significant positive correlation between HIF-1α and ANR in patients with AH. HIF-1α levels are a potential biomarker for hypoxia in patients with AH.