Relationship between the Levels of Calprotectin and Soluble Receptor for Advanced Glycation End Products with Abdominal Aortic Aneurysm Diameter: A Preliminary Clinical Trial.

An abdominal aortic aneurysm (AAA) is a dilatation of the abdominal aorta greater than 50% of the diameter of a healthy aorta. Previous experimental studies confirm the effect of calprotectin (CAL) on the onset of arterial pathology. It has been suggested that low levels of soluble receptors for advanced glycation end products (RAGEs) increase levels of cytokines that lead to the inhibition of matrix metalloproteinases (MMPs), affecting AAA formation. This study aimed to analyze the correlation of levels of RAGE and CAL with AAA diameter. A group of 32 patients aged 50−75 with diagnosed AAA was enrolled in the study. This group of patients was further divided into three subgroups based on AAA diameter: (1) <4.5 cm, (2) 4.5−5.5 cm, (3) >5.5 cm. Peripheral blood was drawn from all participants on admission to measure the serum CAL and RAGE levels. An enumeration survey was performed three months after AAA surgical treatment. CAL and RAGE plasma levels were measured with the enzyme-linked immunosorbent assay (ELISA). The median CAL levels were 2273.0 ng/mL before and 1217.0 ng/mL after treatment. There was a statistically significant decrease in CAL levels following the surgical treatment (p = 0.003). The correlation analysis between CAL levels and RAGE levels before and after surgical treatment showed no statistically significant correlations. In addition, there were no statistically significant correlations between CAL and RAGE levels with AAA size. In conclusion, CAL levels appear to be a significant marker in patients with AAA. There is an almost twofold decrease in CAL levels after AAA excision.

The Role of Serum Calprotectin as a New Marker in Abdominal Aortic Aneurysms - A Preliminary Report.

BACKGROUND: Abdominal Aortic Aneurysm (AAA) remains a surgical challenge. There are many recognizable markers associated with the formation of AAA. Previous experiments carried out on animal models have shown a correlation between serum calprotectin and the occurrence of AAA. OBJECTIVE: This study aimed to evaluate the level of calprotectin as a potential diagnostic biomarker in patients with diagnosed AAA. METHODS: The study group consisted of 75 patients aged 35-75 years assigned to two groups: a control group (n=43) of healthy subjects without AAA and a study group (n=32) of patients with a diagnosed AAA. The first calprotectin test was performed upon patient admission to the hospital, and the second control test was performed after three months. The concentration of calprotectin in plasma was determined using the Immunoenzymatic Method (ELISA) with the commercially available Assaypro Kit (AssayMax™ Human Calprotectin ELISA Kit), as well as the sandwich method with polyclonal antibodies to human calprotectin and peroxidase enzyme. RESULTS & DISCUSSION: Serum calprotectin levels in AAA patients were three times higher than in healthy subjects (p<0.05). A statistically significant twofold decrease in calprotectin concentration was observed after AAA surgery compared to the control group (p<0.05). CONCLUSION: Calprotectin levels can be an important marker in the detection of AAA. In conclusion, AAA patients showed a threefold increase in serum calprotectin level and a twofold decrease in this marker after AAA surgery.

Calprotectin and Receptor for Advanced Glycation End Products as a Potential Biomarker in Abdominal Aortic Aneurysm.

Experiments conducted in recent years on animals and research works worldwide show a linkage between calprotectin and occurrence and development of the abdominal aortic aneurysm (AAA). Additionally, a correlation between the level of the receptor for advanced glycation end products (RAGE) and the diameter of the abdominal aorta was found. The purpose of this study was to investigate whether calprotectin and the RAGE plasma level may be a biomarker of human AAA occurrence. We determined two groups of research participants: a group of 32 patients aged 53-88 undergoing primary endovascular aneurysm repair and a control group of 43 volunteers aged 59-82 without the AAA. All the patients from the study group had their blood samples drawn in order to determine the level of calprotectin and RAGE in plasma. The second follow-up examination was carried out after three months. The concentration of calprotectin and RAGE in plasma was determined with the use of the immunoenzymatic method (ELISA). The study showed that patients with the AAA had significantly higher mean calprotectin and RAGE plasma levels (p = 0.0001 and p = 0.0002, respectively) as compared to the control group. After the AAA repair operations, the level of concentration of the calprotectin decreased significantly (p = 0.0002). So far, no studies on the connection between the increase of the calprotectin and RAGE in the patient's plasma with the AAA have been published. Calprotectin may be a promising biomarker related to the occurrence of AAA. Larger studies are needed to fully elucidate and confirm the role of calprotectin in the development and progression of the aneurysm.

ß-adrenergic antagonists influence abdominal aorta contractility by mechanisms not involving ß-adrenergic receptors.

ß-adrenergic receptors (ß-AR) are widely distributed in the cardiovascular system, where they considerably contribute to the control of its functions. ß-blockers are commonly used in the treatment of disorders of the circulatory system. They act primarily by inhibiting cardiac ß-receptors. However, there are also reports of pleiotropic action of ß-blockers as well as of new compounds created to study ß3 adrenergic receptors. The study aimed to investigate additional mechanisms of action of ß-AR inhibitors in the rabbit abdominal aorta with emphasis on their action on α-adrenergic receptors and calcium influx. Responses to propranolol, betaxolol, metoprolol and SR59230A were evaluated in phenylephrine and PGF(2alpha) precontracted aortic rings. The effect of propranolol on the phenylephrine concentration-contraction curve was examined. Propranolol (≥ 10 µM) and SR59230A (≥ 0.1 µM) induced relaxations in phenylephrine-precontracted rings, while betaxolol and metoprolol had little effect. The ß-AR inhibitors produced further contraction of tissues preincubated with PGF(2alpha), excluding SR59230A, which after initial contraction, elicited marked relaxation at a concentration above 1 eM. 100 µM of propranolol caused a significant rightward shift of the concentration-contraction curve to phenylephrine with no reduction in the maximum response. Incubation of aortic rings in phentolamine reduced the maximal contraction to propranolol; verapamil pretreatment by contrast enhanced contractile response. In conclusion, SR59230A and propranolol most probably act as α1-AR competitive antagonists in the presence of phenylephrine in rabbit abdominal aortic rings. After α-ARs blockade, propranolol exerts a weak relaxing activity connected with Ca2+ channel inactivation. SR59230A at a high concentration acts on the rabbit aorta by an additional mechanism needing further investigation.

Nonspecific effects of ligands on the beta-adrenergic receptors in rabbit abdominal aorta in vitro.

The study was conducted on 30 New Zealand rabbits weighing 3-4 kg from which sample strips of the abdominal aorta were collected. The study investigated the in vitro reaction of rabbit aorta smooth muscle to ligands binding to beta-adrenergic receptors. The response of aortic strips to beta-adrenergic receptor agonists (dobutamine, isoproterenol, salbutamol) and the influence of beta-adrenergic receptor antagonists (propranolol, betaxolol) on contractile activity was determined. All tested agonists induced contraction of the rabbit abdominal aorta muscle in a concentration-dependent manner (dobutamine >> isoproterenol > salbutamol). Enhanced reaction to low concentrations of agonists (dobutamine, isoproterenol) after administration of propranolol and inhibition of contractility in the presence of high concentrations thereof (dobutamine, salbutamol) was observed. Maximal reaction to agonists decreased after betaxolol pretreatment. The results indicate that all the substances with beta-agonist activity also possess contracting properties (presumably by acting at alpha-adrenergic receptors), but are much weaker in the case of isoproterenol and salbutamol than for dobutamine. Propranolol and betaxolol reduce the contractile response of smooth muscle using probably other mechanisms than those associated with adrenergic receptors.

[Effect of atherosclerotic plaque on the contractility of human abdominal aorta sections]. / Wplyw blaszki miazdzycowej na kurczliwosc skrawków ludzkiej aorty brzusznej.

The study was performed on 18 sections of the aneurysm-like abdominal aorta sampled during elective procedures of aneurysm correction in humans, and 10 sections of pig abdominal aorta. We examined the extent to which the presence of atherosclerotic plaque impaired the aorta contractile function and measured the thickness and weight of atherosclerosis plaque and arterial wall. We observed reduced tissue response to adrenaline in human aneurysm-like aorta in comparison to the control group. In the sections of human aorta devoid of atherosclerotic plaque the response to adrenaline was about 30% higher than in those with atherosclerotic changes but 35% lower than in normal aorta sections from pigs. The wall of aneurysm-like human aorta sections was thinner when compared to normal aorta.

[Minimally invasive access to the abdominal aorta in pigs]. / Malo inwazyjne dojscie operacyjne do aorty brzusznej u swin.

Experiments were conducted on 10 sows weighing 50-60 kg. Animals were randomly divided into two experimental groups comprising 5 individuals each. Surgical procedure of reaching the abdominal aorta below the renal arteries was performed using two different methods. In animals from the first group the procedure involved cutting the linea alba in order to obtain access to the abdominal aorta through the abdominal cavity. In the second group the access to the abdominal aorta was obtained by retroperitoneal approach. The approach was made in lower lateral one-third of the abdomen cutting through the muscles and without opening the peritoneal cavity. The study showed superiority of the second surgical method over the median approach along the linea alba in the form of: better animal survival (100% of animals), shorter procedure time, lack of postoperative complications, shorter recovery period and better general postoperative condition

Comparison of the effect of alpha1- and alpha2-adrenoceptor agonists and antagonists on muscle contractility of the rabbit abdominal aorta in vitro.

The aim of the study was to demonstrate the effect of selected agonists and antagonists of alpha-adrenergic receptors on muscle contractility of the rabbit abdominal aorta in vitro with particular emphasis on alpha2-adrenergic receptor subtypes. The study was conducted on 30 New Zealand breed rabbits from which specimens of the abdominal aorta were collected. The sections were set up in an automatic water bath in a Krebs-Henseleit buffer at 37 degrees C. The experiments showed that alpha1-adrenergic receptors played the main role in the contractile response ofthe rabbit abdominal aorta. Stimulation of alpha1-adrenergic receptor by administration ofphenylephrine resulted in an increase in smooth muscle tonus ofthe rabbit abdominal aorta by an average of 4.75 mN. The reaction after stimulation of alpha2-adrenergic receptors by similar doses of their agonists was much weaker. Prolonged tissue response time and time needed to reach maximum tonus for alpha2-adrenergic receptor agonists were observed. The obtained results confirm the thesis that the alpha1-adrenergic receptor is the most important factor controlling the contractility of the rabbit abdominal aorta, but the alpha2-adrenergic receptor is also involved in maintaining muscle tissue tonus.

In vitro contractility of normal and aneurysmal abdominal aorta muscle coat sections in human and animal material.

The objective of the study was to demonstrate spontaneous contractile activity of the smooth muscle coat of the aorta in human and animal material. Spontaneous contractility of smooth muscle tissue, or tonus, is essential for the proper function of many internal organs as observed in the many types of muscle cells which make up the internal structures. The spontaneous contractile activity of the muscle tissue in blood vessels is particularly marked in resistance vessels, regulating circulation within organs or tissues. It can also be observed in large blood vessels such as arteries and veins. The contractile activity of muscular tissue isolated from arteries is the result of a number of factors, including endogenous paracrine substances, neurotransmitters released at postganglionic endings (mostly within the sympathetic system), cells capable of spontaneously generation of functional potentials (pacemaking cells) and the vascular endothelium. Pacemaking cells present in the aortic wall are an important factor in the development of the spontaneous contractility of the muscular coat of the aorta. They are capable of generating functional potentials, resulting in the constant tonus of the smooth muscular coat (comprising the aortic wall) due to tonic contraction. In vitro studies were carried out on abdominal aortic sections collected from 30 New Zealand rabbits with a body mass of 3-4 kilograms each and also on aneurysmal abdominal aortic sections collected during elective aneurysm repair procedures in humans (10 abdominal aortic sections). The 1.5 cm-long sections were mounted in chambers of an automated water bath. The sections were oriented in a transverse and longitudal fashion in order to compare contractility. The incubation medium consisted of Krebs-Henseleit buffer. Spontaneous contractile activity was observed during the study, characterized by rhythmic contractions of the muscular layer of the aorta. The contractile tension within the sections was 0.15 mN in the case of rabbit sections and 0.8 mN in the case of human sections. The average duration of a single contraction was 38.3 +/- 15.05 seconds. The average contraction frequency, i.e. the average number of contractions per minute, was 1.61 +/- 0.54 contractions per minute. The spontaneous contraction is modulated by many factors like endogenous paracrine substances, neurotransmitters or vascular endothelium.

[The evaluation of costs of the abdominal aortic aneurysm endovascular treatment]. / Ocena kosztów leczenia tetniaka aorty brzusznej metoda endowaskularna.

UNLABELLED: Abdominal aortic aneurysm (AAA) treatment by means of stentgraft implementation is a less post-operationally after-effected, way of treating the AAA on the contrast to the more traditional method. The aim of this study was to evaluate the costs of stentgraft implementation. MATERIAL AND METHODS: In the years 2001-2006 65 patients were implemented the intervascular prosthesis. Only the patients with severe chronic medical problems were qualified for the treatment: 31 with the respiratory failure, 29 with the circulatory failure and 5 after the stroke with spastic hemiplegia. After CT of the abdominal cave and the angiography performed at the general anaesthetic the intervascular prosthesis was implemented. RESULTS: After the endovascular procedure was performed the complications could be noticed among 7 patients (10.76%), one patient died (1,53%). After obtaining the data from the Marketing Department the overall cost of treating the patients with endovascular prosthesis was 47500.39 PLN. CONCLUSION: Among patients with abdominal aortic aneurysm and with severe chronic medical problems costs of the endovascular prosthesis implementation are high, because costs of the stentgraft are high.

[Costs evaluation of operation treatment of ruptured and non-ruptured abdominal aortic aneurysm]. / Ocena kosztów operacji peknietego i niepeknietego tetniaka aorty brzusznej.

UNLABELLED: Abdominal aortic aneurysm operation, performed in the emergency mode, has a much larger mortality than the operation of the aneurysm in scheduled mode. The aim of this study is to compare the treatment costs of the aneurysm operated in the emergency mode and scheduled mode. MATERIAL AND METHODS. 125 patients with abdominal aortic aneurysm were take under consideration, 18 of whom were admitted because of the abdominal aortic aneurysm rupture, and 107 of them were admitted without the signs of rupture. From 107 patients admitted in the scheduled mode, 25 were not qualified to the operation because of: other coexisting illnesses (10), recent stroke (1), not agreeing to the surgical intervention (4) and 10 were observed because of the small diameter of the aneurysm and lack of pain. RESULTS: After receiving the costs from the accountants, we analyzed the costs of treatment in the ruptured and non-ruptured aortic aneurysms. CONCLUSIONS: The total cost of the treatment of ruptured abdominal aortic aneurysm is almost as twice higher as the treatment cost of non-ruptured abdominal aortic aneurysm.