A comparative evaluation of low-density lipoprotein cholesterol estimation: Machine learning algorithms versus various equations.

BACKGROUND: Given the critical importance of Low-density lipoprotein cholesterol (LDL-C) levels in determining cardiovascular risk, it is essential to measure LDL-C accurately. Since the Friedewald formula generates incorrect predictions in many circumstances, new equations have been developed to overcome the Friedewald equations' shortcomings. This study aimed to compare estimated LDL-C with directly measured LDL-C (dLDL-C), as well as their performance in predicting LDL-C, utilizing Friedewald, extended Martin-Hopkins, Sampson, de Cordova, and Vujovic formulas and five machine learning (ML) algorithms. METHODS: A total of 29,504 samples from the ISLAB-2 Core Laboratory were included in the study. All statistical analysis was performed using R version 4.1.2. Statistical Language. RESULTS: Bayesian-Regularized Neural Network (BRNN) (r = 0.957) and Random Forest (RF) (r = 0.957) algorithms showed a higher correlation with dLDL-C than the other equations in all-testing dataset. All ML algorithms demonstrated less bias than pre-existing LDL-C equations with dLDL-C and outperformed the LDL-C estimation equations in terms of concordance in all-testing dataset. CONCLUSIONS: The results of our research indicate that when compared to conventional equations, ML algorithms are much more effective in predicting LDL-C. ML algorithms, aided by a vast dataset, could have the capability to predict LDL-C levels even in cases where triglyceride levels are high, unlike the limited usage of Friedewald formula.

Native thiol decreases in patients with asymptomatic primary hyperparathyroidism, especially in the presence of surgery indication.

BACKGROUND: Oxidative stress increases in many systemic and endocrine diseases. The effect of increased parathyroid hormone levels (PTH) and the effects of this hormone on oxidative stress in patients with primary hyperparathyroidism (pHPT) is unknown. We aimed to investigate the change of Thiol-disulfide (SH-SS), one of the oxidative stress parameters, in patients diagnosed with pHPT and the usability of this parameter in patients with pHPT. METHODS: Forty-six patients who recently diagnosed with asymptomatic pHPT and 40 healthy controls were included in this prospective study. In addition to routine examinations for pHPT, serum SH-SS measurements were recorded. The pHPT patients included in the study were divided into two groups as patients with and without surgical treatment indication. RESULTS: It was observed that the pHPT group had lower total SH and native SH values and higher SS values compared to the control group (P<0.05 for each). Native SH values were found to be lower in pHPT patients who were indicated for surgical treatment compared to those who did not (P<0.05). An independent relationship was found between Native SH and serum calcium, urine calcium and T scores in DEXA level in asymptomatic pHPT patients with surgical treatment indication (P<0.05). CONCLUSIONS: In our study, native SH level decreases in patients with pHPT, especially in patients with surgical treatment indication for pHPT. The decrease in SH levels, which is a natural antioxidant that protects the body against oxidative stress, and the increase in SS levels in pHPT patients may be another metabolic effect of this disease. Native SH may be helpful in determining the indication for surgical treatment in asymptomatic pHPT patients.

Should lactate be added to Tokyo criteria for the evaluation of patients with acute cholangitis?

BACKGROUND: Tokyo guidelines (TG13/18) are used for the severity assessment of acute cholangitis (AC). Lactate is a clinical marker of tissue hypoxia and disease severity, independent from blood pressure. AIM: The aim of this study is to investigate the relationship between blood lactate level and TG13/18 criteria in patients diagnosed with AC. METHODS: One hundred fifteen patients with AC were included in this retrospective study. Demographic characteristics of the patients and laboratory data were scanned from their hospital medical records. According to TG13/18 guidelines, the patients were divided into 3 groups as mild (grade 1), moderate (grade 2), and severe (grade 3) AC. RESULTS: Sixty three (54.7%) of the patients were grade 1, 37 (32.1%) were grade 2, and 15 (13.0%) were grade 3. It was found that blood lactate level increased significantly from grade 1 to grade 3 (p < 0.001). In logistic regression analysis, white blood cell (WBC) count, total bilirubin and blood lactate levels independently determined the patients to be grade 2 or 3 AC. When the blood lactate cut-off value was taken as 16.5 mg/dL, we diagnosed grade 2 or 3 AC with a sensitivity of 78.8% and a specificity of 75.7%. From among lactate, WBC, and C reactive protein, lactate showed the highest value regarding the area under the curve, which is an index for predicting grade III upon ROC analysis. CONCLUSION: The blood lactate level is associated with the severity of AC. In addition to TG13/18 guidelines, blood lactate level can be a useful biomarker in the severity grading of AC.

Serum Elabela level is related to endoscopic activity index in patients with active ulcerative colitis.

BACKGROUND: In ulcerative colitis patients, Elabela levels and the relation of Elabela with laboratory parameters is unknown. AIM: The purpose of this study was to investigate the serum Elabela levels in UC patients and its relationship with other clinical and laboratory findings. METHODS: Forty-three patients with UC and 40 healthy controls (group I) similar in age and gender were included in the study. Routine patient history, physical examination, and laboratory tests were followed by analysis of serum Elabela levels. Endoscopic activity index (EAI) of patients with UC was calculated. There were two groups of patients: those in remission (group II) and with active disease (group III). RESULTS: Groups I, II, and III had 40, 22, and 21 participants, respectively. Serum Elabela levels were found to be 3.32 ± 1.25 ng/mL in group I, 3.38 ± 0.88 ng/mL in group II, and 5.48 ± 1.61 ng/mL in group III. Comparing the serum Elabela levels, a statistically significant difference was found between three groups (p < 0.001). Serum Elabela level showed a significant and positive correlation with EAI, leukocyte count, and hs-CRP, while a negative correlation was found with hemoglobin levels in univariate analysis (p < 0.001, for each). In linear regression analysis, these parameters were found to be associated with EAI and hs-CRP (p = 0.049, ß = 0.337, and p = 0.015, ß = 0.396, respectively). CONCLUSION: Elabela concentrations in patients with active UC was significantly higher and was associated with EAI and hs-CRP. Blood Elabela concentrations can be useful in the diagnosis and follow-up of patients with active UC.

Angiostatin levels in diabetes mellitus patients receiving insulin treatment: associations with laboratory findings, comorbidities, and medications

Background/aim: The clinical effect of angiostatin in diabetes mellitus (DM) patients receiving insulin is a meaningful gap in the literature. In this study, we aimed to show the levels and the clinical significance of angiostatin in DM patients receiving insulin. Materials and methods: This is a case-control study. Serum angiostatin levels were determined by ELISA. A total of 83 people consisting of healthy subjects (n = 36) and patients with a diagnosis of DM receiving insulin therapy (n = 47) were included in this study. Results: The mean angiostatin levels of the DM group were significantly higher than those of the control group (86.0 ± 68.1 ng/mL and 58.0 ± 22.4 ng/mL, respectively; P = 0.011). Significantly lower angiostatin levels were determined in the DM patients receiving metformin with respect to those not receiving metformin (97.2 ± 74.4 ng/mL and 49.3 ± 7.0 ng/mL, respectively; P = 0.021). Significantly higher levels of angiostatin were observed among the DM patients using a beta-blocker (BB) than the DM patients not using a BB (115.5 ± 78.71 ng/mL and 73.44 ± 60.08 ng/mL, respectively; p = 0.029). Conclusion: This is the first study evaluating and demonstrating the serum angiostatin levels in DM patients receiving insulin. Further studies are required to understand the effect of angiostatin in diabetics and the effect of medications on angiogenesis in these patients.

Evaluation of the effects of different treatment modalities on angiogenesis in heart failure patients with reduced/mid-range ejection fraction via VEGF and sVEGFR-1.

OBJECTIVES: To investigate the clinical significance of VEGF, sVEGFR-1 in heart failure reduced ejection fraction (HFrEF) and heart failure mid-range ejection fraction (HFmrEF) patients. Methods: A total of 104 people consisting of HFrEF and HFmrEF patients (n=54) and healthy (n=50) subjects were included in this comparative cross-sectional study. The study took place in Gulhane Training and Research Hospital, Ankara, Turkey, between  2011 and 2013. Serum VEGF, sVEGFR-1, plasma pro-BNP analysis and transthoracic echocardiography were performed.  Results: The average sVEGFR-1 level of the HFrEF and HFmrEF patients was significantly higher than the control group (0.185±0.122; 0.141±0.120; p=0.013). The average sVEGFR-1 level of the HFrEF and HFmrEF patients using beta-blocker was significantly higher than the HFrEF and HFmrEF patients not using it (p=0.015). There was a significant and positive correlation between sVEGFR-1 and N-terminal pro-brain natriuretic peptide (pro-BNP)  levels in the group with HF (r=0.211, p=0.044). Conclusion: It increases awareness about the role of sVEGFR-1 in HFrEF anf HFmrEF patients and the need for further studies. Beta-blocker may have a negative effect on angiogenesis in HFrEF and HFmrEF via increasing sVEGFR-1 levels. Additionally, Pro-BNP may contribute to inhibiting angiogenesis by increasing sVEGFR-1 levels and sVEGFR-1 may be an important biomarker in HFrEF and HFmrEF.

Vascular endothelial growth factor and soluble vascular endothelial growth factor receptor-1 in patients with end-stage renal disease. Associations with laboratory findings, comorbidities, and medications.

OBJECTIVES: To show the levels of vascular endothelial growth factor (VEGF), soluble vascular endothelial growth factor receptor-1 (sVEGFR-1) in patients with end-stage renal disease (ESRD) and to show the associations with clinical findings such as demographic features, laboratory findings, comorbidities, and medications. METHODS: A total of 73 people, consisting of patients with ESRD (n=38) and healthy subjects (n=35) in Gulhane Education and Research Hospital, Ankara, Turkey, were included in this cross-sectional study between the years 2011 and 2013. Blood samples were obtained and plasma VEGF, sVEGFR-1 analyzes were performed. Results: The VEGF level of ESRD group was not significantly higher (0.280±0.264) than the control group (0.321±0.210) (p=0.475). The sVEGFR-1 level of ESRD group was significantly higher (0.217±0.135) than the control group (0.068±0.047) (p less than 0.001). The correlation between VEGF and sVEGFR-1 was significant and negative (r=-0.246, p=0.036). Average VEGF level of ESRD patients using recombinant human erythropoietin (rhEPO) was significantly higher (0.567±0.28) than the ESRD patients not using rhEPO (0.246±0.24) (p=0.025). CONCLUSION: Our study is the first showing the significance of sVEGFR-1 in ESRD patients, and associations with comorbidities, medications. Especially our finding of rhEPO and VEGF may illuminate a reasonable positive effect of rhEPO on angiogenesis. Soluble vascular endothelial growth factor receptor-1 and VEGF may be important markers in the pathophysiology of ESRD.

Increased Endothelial Dysfunction and Insulin Resistance in Patients with Klinefelter Syndrome.

BACKGROUND AND OBJECTIVE: Patients with Klinefelter Syndrome (KS) have increased cardiometabolic risk however the pathogenesis is not clear. We investigated the presence of endothelial dysfunction, insulin resistance and inflammation in an unconfounded population of KS. METHODS: A total of 32 patients with KS (mean age 21.59 ± 1.66 years) and 33 healthy control subjects (mean age: 22.15 ± 1.03 years) were enrolled. The demographic parameters, Asymmetric dimethylarginine (ADMA), homeostatic model assessment of insulin resistance (HOMA-IR) index and highsensitivity C-reactive protein (hs-CRP) levels were measured. RESULTS: The patients had higher Follicle Stimulating Hormone (FSH), Luteinizing Hormone (LH), insulin, HOMA-IR and ADMA levels (p < 0.001 for all) and lower High Density Lipoprotein Cholesterol (HDL-C) and total testosterone levels (p=0.002 and p<0.001, respectively), compared to the healthy controls. Total testosterone levels were significantly negatively correlated to ADMA (r = - 0.479, p < 0,001), hs-CRP (r = -0.291, p = 0.034) and positively correlated to HDL-C (r = 0.429, p = 0.001) levels. The multivariate analysis has shown that total testosterone (ß = -0.412, p = 0.001) and TG (ß = 0.332, p = 0.009) levels were the significant independent determinants of the plasma ADMA levels. CONCLUSION: The results of the present study show that endothelial dysfunction and insulin resistance are prevalent even in the very young subjects with KS, who have no metabolic or cardiac problems at present. Also, hypogonadism seems to play an important role for increased cardiometabolic risk in patients with KS.

Effects of triethylene glycol dimethacrylate (TEGDMA) on the odontoclastic differentiation ability of human dental pulp cells.

OBJECTIVES: The primary purpose of this study was to examine the effects of triethylene glycol dimethacrylate (TEGDMA) on odontoclastic differentiation in the dental pulp tissue. MATERIAL AND METHODS: The effects of different TEGDMA dosages on the odontoclastic differentiation capability of dental pulp cells were analyzed in vitro using the following methodologies: i) flow cytometry and tartrate-resistant acid phosphatase (TRAP) staining; ii) apoptotic effects using Annexin V staining; iii) mRNA expression of osteoprotegerin (OPG) and receptor activator of nuclear factor (NF)-kB ligand (RANKL) genes by quantitative Real-time PCR (qRT-PCR); and iv) OPG and RANKL protein expression by enzyme-linked immunosorbent assay (ELISA). RESULTS: TEGDMA caused relatively less odontoclastic differentiation in comparison with the control group; however, odontoclastic differentiation augmented with increasing doses of TEGDMA (p<0.05). The mRNA and protein expression of OPG was lower in TEGDMA treated pulp cells than in the control group (p<0.05). While the mRNA expression of RANKL remained unchanged compared to the control group (p>0.05), its protein expression was higher than the control group (p<0.05). In addition, TEGDMA increased the apoptosis of dental pulp cells dose dependently. CONCLUSIONS: TEGDMA reduced the odontoclastic differentiation ability of human dental pulp cells. However, odontoclastic differentiation ratios increased proportionally with the increasing dose of TEGDMA.

Angiogenic Heparin-Mimetic Peptide Nanofiber Gel Improves Regenerative Healing of Acute Wounds.

Wound repair in adult mammals typically ends with the formation of a scar, which prevents full restoration of the function of the healthy tissue, although most of the wounded skin heals. Rapid and functional recovery of major wound injuries requires therapeutic approaches that can enhance the healing process via overcoming mechanical and biochemical problems. In this study, we showed that self-assembled heparin-mimetic peptide nanofiber gel was an effective bioactive wound dressing for the rapid and functional repair of full-thickness excisional wounds in the rat model. The bioactive gel-treated wounds exhibited increased angiogenesis (p < 0.05), re-epithelization (p < 0.05), skin appendage formation, and granulation tissue organization (p < 0.05) compared to sucrose-treated samples. Increased blood vessel numbers in the gel-treated wounds on day 7 suggest that angiogenesis played a key role in improvement of tissue healing in bioactive gel-treated wounds. Overall, the angiogenic heparin-mimetic peptide nanofiber gel is a promising platform for enhancing the scar-free recovery of acute wounds.

A novel model of retinopathy of prematurity in normobaric hyperoxic conditions.

AIM: To examine changes in retinal vasculature after treatment with different oxygen concentrations from common retinopathy of prematurity (ROP) models and to determine a novel and practical ROP model. METHODS: A sample of 14 newborn Sprague-Dawley rats was used. The study group (n=7) was exposed to 95% oxygen for 4h per day followed by normoxic laboratory conditions for 20h. This cycle was repeated for 14d. The control group (n=7) was subjected to normobaric normoxic conditions. On postnatal day 14 (P14), the two groups were placed in room air for 7d. On P21, the two groups were examined using indirect ophthalmoscopy. All eyes were enucleated for immunofluorescence (IF) staining of the vasculature of retinas and analysis of vascular endothelial growth factor (VEGF), hypoxia inducible factor-1 alpha (HIF-1α), placental growth factor (PLGF) in vitreous humor, and then the rats were sacrificed by decapitation. All procedures were repeated using another litter of 14 pups. RESULTS: In the study group and under normobaric hyperoxic conditions, retinal neovascularization and peripheral avascular retina were determined in 85% of the rats through indirect ophthalmoscopic examination. Also IF staining of retina of the study group showed retarded peripheral vascular growth. The difference between the two groups for VEGF, HIF-1α and PLGF concentrations of vitreous humor was statistically significant (P=0.003, 0.007, 0.027 respectively). CONCLUSION: Fluctuating oxygen concentrations are primarily responsible for retinal neovascularization. Our new ROP model is practical and applicable for all retinal neovascularization studies, considering the laboratory procedures.

Angiopoietins in Human Breast Milk.

INTRODUCTION: Angiogenesis is an important process after birth for neonates. Vascular endothelial growth factor is a potent proangiogenic protein, which stimulates endothelial cell proliferation, survival, and migration. For vessel maturation, all components have to move together. Angiopoietins (ANG) are very important signal proteins for pericytes and have not yet been determined in human breast milk. The aim of this study was to show whether there were ANG in human breast milk. METHODS: Human breast milk samples were collected from 9 mothers of preterm (≤33 weeks) and 17 mothers of term and late preterm (>33 weeks). Milk samples were collected on 3rd, 7th, and 28th days from delivery. We analyzed ANG-1 and ANG-2 levels in human milk and compared these levels considering the gestational age and day of lactation from delivery. RESULTS: There was a significant difference between the ANG-1 levels of the two groups of gestational age (p = 0.008), while ANG-2 levels were not significantly different (p = 0.821), without considering the days of lactation from delivery. ANG-1 and 2 levels of milk samples of 3rd, 7th, and 28th days from lactation showed no significant difference in both gestational age groups. CONCLUSION: The presence of ANG in human breast milk was proved with this study and ANG-1 levels were found to be lower in preterm group. These results may be important for neonates in terms of angiogenesis and also lymphangiogenesis.

Pentraxin 3 Is a Predictor for Fibrosis and Arterial Stiffness in Patients with Nonalcoholic Fatty Liver Disease.

Objective. The aim of the present study was to investigate whether pentraxin 3 (PTX3) can be a new noninvasive marker for prediction of liver fibrosis in patients with NAFLD. We also aimed to evaluate the relationship between PTX3 and atherosclerosis in patients with NAFLD. Method. Fifty-four male patients with biopsy-proven NAFLD and 20 apparently healthy male volunteers were included. PTX3 levels were determined, using an ELISA method (R&D Sysytems, Quantikine ELISA, USA). To detect the presence of subclinical atherosclerosis in NAFLD, measurements of CIMT, FMD, and cf-PWV levels were performed. Results. PTX3 levels in NAFLD patients with fibrosis were higher than both NAFLD patients without fibrosis and controls (P = 0.032 and P = 0.028, respectively), but there was no difference between controls and NAFLD patients without fibrosis in terms of PTX3 levels (P = 0.903). PTX3 levels were strongly correlated with cf-PWV (r = 0.359, P = 0.003), whereas no significant correlation was found with other atherosclerosis markers, CIMT and FMD. Conclusion. Elevated plasma PTX3 levels are associated with the presence of fibrosis in patients with NAFLD, independently of metabolic syndrome components. This study demonstrated that for the first time there is a close association between elevated PTX3 levels and increased arterial stiffness in patients with NAFLD.

Sodium nitrite provides angiogenic and proliferative effects in vivo and in vitro.

BACKGROUND Angiogenesis is the formation of new blood vessels from pre-existing vasculature. Many factors and substances may stimulate angiogenesis and exhibit proliferative effect. In this study, we aimed to investigate the angiogenic and proliferative effects of sodium nitrite. MATERIAL AND METHODS The angiogenic activity of sodium nitrite was examined in vivo in the chick chorioallantoic membrane (CAM) model and in vitro in tube formation assay of human umbilical vein endothelial cells (HUVECs). The proliferative activity of sodium nitrite was also determined through MTT assay on HUVECs. RESULTS In CAM assay, sodium nitrite had an angiogenic effect especially at high concentrations compared with the control group and this was statistically significant. There was a proliferative effect on HUVECs in the presence of sodium nitrite for 24 and 48 h, and this was statistically significant (p<0.05). Comparing the tube length/area ratio values, there was statistically significant increase in the sodium nitrite group compared to the control group (p<0.05). CONCLUSIONS The results provide evidence that sodium nitrite induces angiogenesis in vitro and in vivo.

Comparison of four automated serum vitamin B12 assays.

BACKGROUND: Diagnosis of vitamin B12 deficiency is generally based on the measurement of serum vitamin B12 levels. However, in selected cases functional indices of vitamin B12, such as methylmalonic acid (MMA) and homocysteine (HCY), are needed. Here we compare the performance of four automated total vitamin B12 assays and also investigate how these assays relate to functional indices of vitamin B12 status. METHODS: Total vitamin B12, MMA and HCY were measured in 69 serum samples from routine vitamin B12 assay requests. Serum vitamin B12 analysis was performed using four different immunoassay autoanalyzers: DxI 800 Unicel (Beckman Coulter, USA), ADVIA Centaur XP (Siemens Diagnostics, Tarrytown, NY, USA), Roche Cobas E601 (Roche Diagnostics, Germany), Architect i2000sr (Abbott Laboratories, Abbott Park, IL, USA). Serum MMA levels were determined by liquid chromatography-mass spectrometry (LC-MS) and serum homocysteine levels were determined by high pressure liquid chromatography (HPLC) methods. RESULTS: Four immunoassay methods were comparable and correlated with each other. Correlation coefficients (r) ranged from 0.898 to 0.987, p<0.001. Highest correlation was observed between Roche Cobas - Architect i2000sr and poorest correlation was observed between DxI 800 Unicel - ADVIA Centaur comparison. DxI 800 Unicel assay demonstrated high mean bias [-122 pg/mL (-616-125 pg/mL)] and a concordance correlation coefficient (CCC) of 0.9161, lower than the others. MMA and HCY were correlated with the vitamin B12 results. The correlation coefficients with their 95% CI indicated that there was no statistically significant difference between the four methods according to their relationship with MMA and HCY. CONCLUSIONS: Total B12 assays correlate very well with each other. However, results of DxI 800 Unicel were lower compared to the other three autoanalyzers. All total vitamin B12 methods show similar relationships with HCY and MMA. Standardization of serum vitamin B12 assays is still not completed and further standardization studies are needed. Laboratory professionals and clinicians should be aware of this disagreement between assay methods and they should use these tests as ancillary tests.

Blood total carbon dioxide content and bicarbonate can be used together to predict blood pH correctly in venous blood samples.

Blood gas analyses are needed to reveal any kind of acid-base imbalance in some patients. Traditionally, arterial punctures are performed to obtain the blood samples for blood gas analyses. Arterial puncture is not a completely safe procedure. It may cause serious problems including arterial thrombosis, arteriovenous fistula, pseudoaneurysms and hematoma. In this retrospective reviewing, it was aimed to yield novel formulations to predict the blood pH only from CtCO2 and HCO3 values which can easily be measured in venous blood samples obtained for other diagnostic and follow-up purposes.