Transport of Low-Density Lipoprotein Into the Blood Vessel Wall During Atherogenic Diet in the Isolated Rabbit Carotid Artery.

BACKGROUND: Atherosclerosis is a chronic fibroproliferative disease that includes accumulation of cholesterol-rich lipids in the arterial wall. Though numerous studies have investigated atherosclerosis, not enough is known about the exact mechanisms of low-density lipoprotein (LDL) transport into the blood vessel wall. Therefore, we explored the (125)I-LDL transport into the arterial wall under constant perfusion flow and pressure as well as the influence of duration of atherogenic diet on (125)I-LDL transport and biomechanical properties of carotid artery. METHODS AND RESULTS: The isolated segment of rabbit carotid artery was used under constant perfusion flow and pressure-induced (0 mmHg and 140 mmHg) blood vessel distension, with the possibility to change and precisely calculate shear stress during the experiment. Obtained results indicate the influence of atherogenic diet duration and consequent variation of shear stress on (125)I-LDL transport into the blood vessel wall. (125)I-LDL transport into the blood vessel wall at low pressure-induced blood vessel distension decreases by the increase of the shear stress and in relation to the atherogenic diet duration. At high pressure-induced blood vessel distension, (125)I-LDL transport increases in relation to the atherogenic diet duration and the increase of shear stress. CONCLUSIONS: The influence of shear stress is a more dominant parameter on LDL uptake at low pressure-induced blood vessel distension; however, the atherogenic diet duration has more of a dominant influence on LDL uptake at high pressure-induced vessel distension.

Histamine blood concentration in ischemic heart disease patients.

The aim of this study was to investigate histamine blood concentration in subjects suffering from different types of ischemic heart diseases during the period of eight days. Our results showed that the histamine blood level was associated with different types of ischemic heart diseases. The blood histamine level in all investigated patients was significantly higher when compared to control subjects (44.87 ± 1.09 ng mL(-1)), indicating the increase of histamine release in patients suffering from coronary diseases. In patients suffering from ACS-UA and ACS-STEMI, the second day peak of histamine level occurs (90.85 ± 6.34 ng mL(-1) and 121.7 ± 6.34 ng mL(-1), resp.) probably as the reperfusion event. Furthermore, our data suggest that histamine can be additional parameter of myocardial ischemia along with cardiac specific enzymes and may prove to be an excellent single prognostic marker for multitude of ischemic heart diseases.

The new experimental model for behavioral investigations in animal studies.

In this paper a video file based approach to evaluate position and locomotion in animal behavior experiments is described. For this purpose original software Animal Tracker for transforming a video data to a log file which is suitable for further computational analyzes, was developed. To perform analyzes from the log file, an additional software PostProc), which enables assessment of locomotion, velocity or place preferences, was created. For video recording software called DScaler was used. This is an open source software and freely available for download. The method that we describe in this paper is based on simple video equipment and supported by three software mentioned above. This method enables performing of a wide diversity of experimental designs without limitations in time duration, color and light conditions, shape and size of experimental area and/or investigated objects. As an example, results obtained from experiments with rats in an Open-field test are included. One group of animals was treated with benzodiazepine (2 mg.kg(-1), single dose, subcutaneously). This easy to use system can be implemented in most laboratories without any special training and used by investigators in the field of animal behavior research.

Dynamic response of blood vessel in acute renal failure.

In this study we postulated that during acute renal failure induced by gentamicin the transient or dynamic response of blood vessels could be affected, and that antioxidants can prevent the changes in dynamic responses of blood vessels. The new approach to ex vivo blood vessel experiments in which not only the end points of vessels response within the time interval is considered, but also dynamics of this response, was used in this paper. Our results confirm the alteration in dynamic response of blood vessels during the change of pressure in gentamicin-treated animals. The beneficial effects of vitamin C administration to gentamicin-treated animals are also confirmed through: lower level of blood urea and creatinine and higher level of potassium. The pressure dynamic responses of isolated blood vessels show a faster pressure change in gentamicin-treated animals (8.07 +/- 1.7 s vs. 5.64 +/- 0.18 s). Vitamin C administration induced slowdown of pressure change back to the control values. The pressure dynamic properties, quantitatively defined by comparative pressure dynamic and total pressure dynamic, confirm the alteration in dynamic response of blood vessels during the change of pressure in gentamicin-treated animals and beneficial effects of vitamin C administration.

Evaluation of dynamic response and biomechanical properties of isolated blood vessels.

In this study we present the experimental and mathematical model for a precise assessment of isolated blood vessels dynamic response under a sudden change of blood pressure. Only the end points within the time interval of the considered dynamic response of the blood vessel, or so-called "alternate steady states" of the processes, were usually considered in various studies. These studies do not provide an insight how the process variables change between these alternate steady states. Isolated blood vessels (rat abdominal aorta) were used to determine how the process dynamics can be described in detailed quantitative terms by mathematical parameters. The experimental model and mathematical procedures presented in this study describe precisely (at a high sensitivity level) the time history of the pressure and the diameter change in between alternate steady states, when an abrupt change of blood pressure occurs at the vessel outlet. Also, the experimental model and mathematical procedures were used to determine changes in the stress-strain law, caused by the action of L-arginine. The presented experimental design and mathematical model can be used for assessment of isolated blood vessel dynamic responses under different stimuli, such as drug effects, electrostimulation etc.

Histamine index and clinical expression of rheumatoid arthritis activity.

BACKGROUND/AIM: Many arguments prove the pathophysiologic role of histamine in the process of remodeling and joint destruction in rheumatoid arthritis. The aim of our study was to find out if there was a relation between histamine concentration in synovial fluid and blood with clinical expression of disease activity. METHODS: Histamine concentration in synovial fluid and blood was determinated in 19 patients with rheumatoid arthritis. Histamine concentration measurement was based on the Shore's fluorometric method. Histamine index (HI) was evaluated as a ratio between histamine concentration in synovial fluid and blood. Disease activity score, DAS 28 (3), with three variables (erythrocyte sedimentation rate, the number of swelled joints and the number of tender joints) was also evaluated. RESULTS: Our results showed that there was no significant difference in concentration of histamine in synovial fluid and blood related to disease activity. However, there was a significiant difference in the histamine index which was increased proportionally with disease activity. CONCLUSION: Our study indicates that histamine index could be useful in estimation of rheumatoid arthritis activity.

[Factors which influence postoperative mortality after hip fracture].

BACKGROUND/AIM: One of the most significant predictors of mortality after hip fractures is cognitive impairment (dementia). The aim of this study was to report the results of a prospective study of the influence of some factors on six-month mortality in elderly patients with hip fractures. METHOD: The elderly patients with hip fracture were assessed on admission to the hospital using the measures of cognitive function, the mobility before the fracture, and physical comorbidity, the type of fracture and the place of the injury. Six months later, we checked how many of them were still alive. RESULTS: We performed univariate and multivariate analyses in 132 patients and found that the most significant predictors of six-month mortality were dementia, comorbidity, and prefacture mobility. CONCLUSIONS: A comprehensive physical and mental health assessment of an elderly patient after hip fracture could predict mortality. A good examination of cognitive functioning could be very useful in choosing the optimal treatment for this type of patients.