Biomarkers in acute myocardial infarction: current perspectives

PURPOSE

Acute myocardial infarction (AMI) is the most common cause of death in the world. Comprehensive risk assessment of patients presenting with chest pain and eliminating undesirable results should decrease morbidity and mortality rates, increase the quality of life of patients, and decrease health expenditure in many countries. In this study, the advantages and disadvantages of the enzymatic and nonenzymatic biomarkers used in the diagnosis of patients with AMI are given in historical sequence, and some candidate biomarkers - hFABP, GPBB, S100, PAPP-A, RP, TNF, IL6, IL18, CD40 ligand, MPO, MMP9, cell-adhesion molecules, oxidized LDL, glutathione, homocysteine, fibrinogen, and D-dimer procalcitonin - with a possible role in the diagnosis of AMI are discussed.

METHODS

The present study was carried out using meta-analyses, reviews of clinical trials, evidence-based medicine, and guidelines indexed in PubMed and Web of Science.

RESULTS

These numerous AMI biomarkers guide clinical applications (diagnostic methods, risk stratification, and treatment). Today, however, TnI remains the gold standard for the diagnosis of AMI. Details in the text will be given of many biomarkers for the diagnosis of AMI.

CONCLUSION

We evaluated the advantages and disadvantages of routine enzymatic and nonenzymatic biomarkers and the literature evidence of other candidate biomarkers in the diagnosis of AMI, and discuss challenges and constraints that limit translational use from bench to bedside.

Saliva and Blood Asprosin Hormone Concentration Associated with Obesity

BACKGROUND

The aim was to investigate the amounts of saliva and serum asprosin in order to determine whether it is related to obesity and whether salivary glands synthesize asprosin or not.

METHODS

A total of 116 underweight, normal weight, overweight, and obese (class I, class II, and class III) volunteers participated in the study. Saliva and blood samples were collected simultaneously from the participants. The amounts of asprosin in saliva, salivary gland tissue supernatants, and bloods were determined by ELISA, whereas asprosin synthesis sites of salivary gland tissues were determined immunohistochemically.

RESULTS

The amount of asprosin from the lowest to the highest was in the order as follows: underweight, normal weight (control), overweight, and obese classes I and III. The lowest level of asprosin was detected in underweight individuals. It was also found that the interlobular striated ducts and the interlobular ducts of the submandibular and parotid salivary glands produce asprosin. According to these data, the asprosin level is related with obesity as the amount increases in accordance with increasing body mass index (BMI). On the other hand, there is also a relationship between the underweight and asprosin because the amount decreases with BMI decrease.

CONCLUSIONS

Asprosin, a new adipokine, may be a novel indicator of adipose tissue mass. Therefore, we anticipate that antiasprosin preparations may be an alternative in the treatment of obesity in the future.

Acylated and desacylated ghrelin, preptin, leptin, and nesfatin-1 Peptide changes related to the body mass index

This study examines the levels of acylated and desacylated ghrelin, preptin, leptin, and nesfatin-1 peptide changes related to the body mass index (BMI). The subjects were allocated to 5 groups depending on their BMIs as follows: Group I (BMI <18.5 kg/m(2)); Group II (BMI 18.5-24.9 kg/m(2)); Group III (BMI 25-29.9 kg/m(2)); Group IV (BMI 30-39.9 kg/m(2)); Group V (BMI >40 kg/m(2)). Serum acylated and desacylated ghrelin, preptin, and leptin levels were measured by the enzyme-linked immunosorbent assay (ELISA) and nesfatin-1 was measured by the enzyme immunoassay (EIA). Desacylated ghrelin levels showed a gradual and statistically significant drop from Group I to Group V, while preptin and leptin levels exhibited a gradual and significant increase from Group I to Group IV. Serum nesfatin-1 levels gradually, but not significantly, increased from Group I to Group III and showed a significant decrease in Groups IV and V. In conclusion, leptin, preptin, and acylated ghrelin (AG) levels increased with higher BMI, whereas desacylated ghrelin (DAG) decreased and nesfatin-1 showed no clear relationship to BMI.

Serum, Saliva, and Urine Irisin with and Without Acute Appendicitis and Abdominal Pain

A 112-amino-acid protein irisin (IRI) is widely expressed in many organs, but we currently do not know whether appendix tissue and blood cells express it. If appendix tissue and neutrophil cells express IRI, measuring its concentration in biological fluids might be helpful in the diagnosis of acute appendicitis (AA), since neutrophil cells are the currently gold-standard laboratory parameters for the diagnosis of AA. Therefore, the purpose of this study was to investigate the suitability of enzyme-linked immunosorbent assay-based measurements of the proposed myokine IRI for the discrimination of patients with AA from those with acute abdominal pain (AP) and healthy controls. Moreover, immunoreactivity to IRI was investigated in appendix tissues and blood cells. Samples were collected on admission (T1), 24 hours (T2), and 72 hours (T3) postoperatively from patients with suspected AA and from patients with AP corresponding to T1-T3, whereas control subject blood was once corresponding to T1. IRI was measured in serum, saliva, and urine by using enzyme-linked immunosorbent assay, whereas in appendix tissue and blood cells, IRI was detected by immunohistohcemistry. Appendix tissue and blood cells (except for erythrocytes) are new sources of IRI. Basal saliva, urine, and serum levels were higher in children with AA compared with postoperative levels (T2) that start to decline after surgery. This is in line with the finding that IRI levels are higher in children with AA when compared with those with AP or control subject levels, most likely due to a large infiltration of neutrophil cells in AA that release its IRI into body fluids. Measurement of IRI in children with AA parallels the increase or decrease in the neutrophil count. This new finding shows that the measurement of IRI and neutrophil count can together improve the diagnosis of AA, and it can distinguish it from AP. IRI can be a candidate marker for the diagnosis of AA and offers an additional parameter to neutrophil count. The promising receiving operating curve results indicate the following sensitivities and specificities, respectively, for IRI: serum 90% and 55%, saliva 90% and 60%, and urine 90% and 50%. Serum neutrophil count gave a sensitivity of 90% and a specificity of 90%. This promising result now needs to be confirmed in a larger group of patients.

Comparison of irisin hormone expression between thyroid cancer tissues and oncocytic variant cells

Objective: The incidence of thyroid cancer has been continuously increasing. The main objective of this study was to investigate irisin expression in various thyroid pathologies and to compare these expression patterns with irisin expression in healthy thyroid tissues. Methods: The study groups consisted of 20 cases each of control thyroid tissue, Hashimoto's thyroiditis, thyroid papillary carcinoma, oncocytic papillary carcinoma, follicular thyroid carcinoma, oncocytic follicular thyroid carcinoma, medullary thyroid carcinoma, anaplastic thyroid carcinoma. Irisin expression was evaluated using immunohistochemistry. Irisin levels in thyroid tissue supernatants were measured using ELISA. Results: Patients with HT showed increased irisin expression compared with controls (p<0.05). In addition, mild immunoreactivity was observed in the thyroid tissues of patients with papillary carcinoma while significantly increased irisin immunoreactivity was observed tissues of patients with oncocytic papillary carcinoma (p<0.05). There was no difference in irisin immunoreactivity in thyroid tissues between patients with follicular carcinoma and controls. However, irisin immunoreactivity was higher in tissues of patients with oncocytic follicular carcinoma than in tissues of patients with follicular carcinoma (p<0.05). No irisin immunoreactivity was observed in tissues of patients with medullary carcinoma, a malignant tumor the thyroid; however, irisin expression was significantly increased in tissues of patients with anaplastic carcinoma compared with that in tissues of controls (p<0.05). Furthermore, in all thyroid tissues with irisin expression, irisin immunoreactivity was observed in follicular cells, indicating that irisin is produced by these cells. Conclusion: Irisin is a novel potential immunohistochemical marker for differentiating oncocytic variants of papillary and FTCs from papillary and follicular thyroid cancers.

Brain, liver, and serum salusin-alpha and -beta alterations in Sprague-Dawley rats with or without metabolic syndrome

BACKGROUND

This metabolic syndrome (MetS) study was designed to investigate changes in expression of the neuropeptides salusin-α (Sal-α) and salusin-β (Sal-β) in brain and liver tissue in response to obesity and related changes induced by high-fructose diet and explored how these changes were reflected in the circulating levels of Sal-α and Sal-b, as well as revealing how the lipid profile and concentrations of glucose and uric acid were altered.

MATERIAL/METHODS

The study included 14 Sprague-Dawley rats. The control group was fed ad libitum on standard rat pellets, while the intervention group was given water with 10% fructose in addition to the standard rat pellet for 3 months. Sal-α and Sal-β concentrations in the serum and tissue supernatants were measured by ELISA, and immunohistochemical staining was used to demonstrate expression of the hormones in brain and liver.

RESULTS

Sal-α and Sal-β levels in both the serum and the brain and liver tissue supernatants were lower in the MetS group than the control group. Sal-α and Sal-β were shown by immunohistochemistry to be produced in the brain epithelium, the supraoptic nucleus of the hypothalamus, and the liver hepatocytes.

CONCLUSIONS

The decrease in Sal-α and Sal-β might be involved in the etiopathology of the metabolic syndrome induced by fructose.

The cardiovascular system and the biochemistry of grafts used in heart surgery

Blood is pumped into the cardiac muscle through arteries called the coronary arteries. Over time, the accumulation of cholesterol, coagulation factors, and cells on the walls of these arteries causes the walls to thicken and lose their elasticity, resulting in the development of atherosclerosis. When the blood supply of the heart is diminished by atherosclerosis, it can be restored by bypass surgery, in which atherosclerosis-free vein and/or artery grafts taken from another area of the body are used to replace the atherosclerotic vessels. These biological grafts used in surgery differ in biochemical composition and long-term patency. Although the great saphenous vein (GSV) has been the most popular graft material in revascularization for years, it has recently been superseded by the internal mammarian artery (IMA), which has a lower incidence of recurrence of atherosclerosis. The aim of the present review is briefly to address the structure of the cardiovascular system and blood vessels, and then, in the light recent data, to present the biochemical compositions and individual advantages of the graft materials used to restore an impaired blood supply to the heart.

Decorin, Tenascin C, Total Antioxidant, and Total Oxidant Level Changes in Patients with Pseudoexfoliation Syndrome

PURPOSE

Pseudoexfoliation syndrome (PEX) is an eye disease that develops under the influence of regional population differences, genetic factors, age, and environmental factors and is characterized by visualization of a gray-white fibrogranular substance in the lens anterior capsule and/or pupil margin during anterior segment examination. The underlying biochemical mechanisms of the disease have not yet been fully elucidated. Therefore, this study was designed to show the changes in aqueous humor and blood serum levels of matrix metalloproteinases (decorin and tenascin C), total antioxidants (TAS), and total oxidants (TOS) in both cataract patients who have unilateral PEX material and cataract patients who do not have unilateral PEX material.

METHODS

Biological samples were simultaneously collected from 22 cataract patients who had unilateral pseudoexfoliation (PEX patients) and 22 cataract patients who did not have unilateral pseudoexfoliation (control patients). From the collected biological samples, decorin (DEC) and tenascin C (TN-C) were measured with the enzyme-linked immunosorbent assay (ELISA) method, and TAS and TOS were measured with an autoanalyzer.

RESULTS

When decorin, tenascin C, and TOS values of PEX patients were compared with those of control patients, there was a statistically significant increase in all three parameters. Conversely, TAS values showed a statistically significant decrease in PEX patients compared to controls. DEC, TN-C, TAS values, and TOS values were significantly higher in aqueous fluid than in blood in both the PEX patient and control groups.

CONCLUSIONS

We suggest that parameters such as DEC, TN-C, TAS, and TOS play a role in the etiopathology of pseudoexfoliation syndrome. Thus, bringing these increased levels of extracellular proteins and TOS and decreased levels of TAS back to within physiological limits can mediate the reorganization of the blood-aqueous fluid barrier and slow the progression of pseudoexfoliation syndrome.

An unusual case of hematemesis and epistaxis caused by a pheochromocytoma

Pheochromocytoma is a rare catecholamine-secreting neoplasm that is the cause of hypertension in <0.2% of patients with hypertension. We encountered an unusual case of pheochromocytoma involving hematemesis and epistaxis episodes with accompanying hypertensive attacks. Venous ectasia was detected in the esophagus. Abdominal magnetic resonance imaging revealed an adenoma in the left adrenal region. The present case illustrates that pheochromocytoma can mimic different clinical conditions.

A High Creatine Kinase Concentration Might Be a Sign of McArdle Disease in Patient With Type 1 Diabetes

Type 1 diabetes (the pancreas producing little or no insulin) is usually diagnosed in children and young adults and was previously known as juvenile diabetes. McArdle disease is a common metabolic defect caused by an inherited deficit of myophosphorylase. These 2 diseases might have some clinical heterogeneity. Here, we discuss a McArdle disease case where insulin-dependent diabetes overshadows its early diagnosis. In this case, an insulin-dependent 22-year-old female patient with diabetes mellitus had been on diabetes treatment for 15 years. Although her blood glucose was regulated, her anamnesis showed that muscle weakness, fatigue, cramps or myalgia never healed. Based on her anamnesis, the patient was asked to take a nonischemic forearm exercise test, which revealed significant elevation in levels of creatine kinase (5968-7906 U/L), but no increase was found in lactate concentration, but a slight increase in ammonia concentration (not statistically significant) at the end of the test made us consider McArdle disease. A genetic test was done to confirm this possibility. A homozygous c.2128_2130delTTC/p.Phe710del mutation was detected in the examination of exons of the PYGM gene, which confirmed the diagnosis of McArdle disease in our patient. According to the data, this is a rare case of McArdle disease with type 1 diabetes. During treatment for diabetes, if the above-mentioned symptoms are present in a patient, and especially if the patient's creatine kinase concentration is high, muscle diseases should be suspected. Therefore, we suggest that this case report will provide new insight to clinicians on metabolic defects in this disease and increase the patient comfort. In such cases, an early diagnosis should reduce health costs.

The effects of fever on hormone ghrelins, immunoglobulins, and heat shock protein 70 expression after swine flu vaccinations

For analyzing the changes in immunoglobulins, HSP70, ghrelin levels in blood samples were collected from volunteers vaccinated against swine flu before the vaccinations and on days 3, and 15, and 1 and 2 months after the vaccination in the presence or absence of fever associated with the it. The study included 11 subjects having developed a fever, and 13 subjects not having a fever, and 20 control subjects. Immunoglobulins were measured by nephelometry, and HSP70 and ghrelins by appropriate ELISA tests. The level of ghrelin was reduced, while the level of HSP70 was significantly increased in subjects who developed fevers. When temperatures were normalized, both levels were found similar to the control group. These results indicate that the increase in serum immunoglobulins levels associated with vaccinations, along with, elevations in HSP70 and reduced ghrelin levels associated with fever, may be the important parameters in the clinical evaluation and follow-up of treatments with vaccines.

An overview of ELISA: a review and update on best laboratory practices for quantifying peptides and proteins in biological fluids

The enzyme-linked immunosorbent assay (ELISA) detects antigen-antibody interactions by using enzyme-labelled conjugates and enzyme substrates that generate colour changes. This review aims to provide an overview of ELISA, its various types, and its applications in detecting metabolites in biological fluids. The article discusses the history of the assay, its underlying principles and procedures, common ELISA protocols, and the most accurate and reliable techniques for measuring peptide molecules in biological fluids. Additionally, we emphasize best laboratory practices to achieve consistent, high-quality results and outline the essential materials for setting up an ELISA laboratory, drawing from our over 30 years of experience in the field.

NUCB2/Nesfatin-1 in the Blood and Follicular Fluid in Patients with Polycystic Ovary Syndrome and Poor Ovarian Response

BACKGROUND

Failure to respond adequately to standard protocols and to recruit adequate follicles is called 'poor ovarian response'. The relationships between metabolic alterations and NUCB2/Nesfatin-1 levels were explored in patients with polycystic ovary syndrome (PCOS) undergoing in vitro fertilization/intracytoplasmic sperm injection.

METHODS

This case-control study involved 20 infertile women with PCOS and 20 control women diagnosed as poor ovarian responders stimulated with a GnRH antagonist. Blood samples were taken during ovum pick-up and follicular fluids (FF) were obtained from a dominant follicle from the subjects. Samples were analyzed by using ELISA. Statistical analysis was performed with SPSS version 20. Data are expressed as means ± standard deviation (SD).

RESULTS

Blood NUCB2/Nesfatin-1 levels in PCOS were significantly lower (p= 0.011) while the NUCB2/Nesfatin-1 levels of FF in poor ovarian response (POR) were higher, but not statistically significant. Insulin, total testosterone, fasting glucose, homeostasis model assessment, and insulin resistance index in women with POR decreased when compared with PCOS. Blood NUCB2/Nesfatin-1 levels were significantly higher than FF NUCB2/Nesfatin-1 levels in both groups (p<0.001). Moreover, a positive correlation was detected between blood NUCB2/Nesfatin-1 and testosterone (p=0.602, r=0.304), HOMA-IR (p=0.252, r=0.384), BMI (p=0.880, r= 0.44) in PCOS, but it was not significant.

CONCLUSION

NUCB2/Nesfatin-1 levels might be important in follicular growth in PCOS subjects undergoing IVF/ICSI with an antagonist protocol and NUCB2/Nesfatin-1 level could reliably help to predict poor ovarian response.