A comparative analysis of human and experimental animal (canine) tissues was performed to characterize and describe cellular and histological responses during the processes of newly forming intravascular tissues after stent implantation. Routine histological and immunohistochemical evaluation of 20 human samples and 9 samples from animal models were used one day, one week and one month after the stent implantation. After one day of implantation, there was no difference between the human and canine peripheral arteries, suggesting a similar cellular and histological response in the early phase. In contrast, after one week of implantation, during the proliferative phase the repairing human tissue showed less intensive production of inflammatory cells and more intensive increase in number of vascular cells than did the canine model. In addition, cellular changes normally restituted by the end of one month in canine peripheral arteries, but vascular cells persisted in human atherosclerotic arteries. In conclusion, results of this study suggest differences in both phases of vascular repair in the post-stented period, because both proliferative and regressive phases showed histological differences in canine and human samples. In canine, the restitution of vascular wall was completed by the end of first month but persistent vascular cell proliferation was visible in the human peripheral arteries. It can be suggested that delayed cellular response might indicate restenosis but also can be considered considered as a progression of the original arterial disease.
The aim of this study was to characterise the development of cardiac dilatation induced by chronic volume overload in 12 dogs. Bilateral arteriovenous fistulas were created between the common femoral arteries and the femoral veins, and the animals were serially studied with transthoracic echocardiography for a period of 12 weeks after the operation. Compared to the measurements obtained before the operation (week 0), the data obtained at the end of the experimental period showed significantly increased left ventricular volume measured by 2D-echocardiography (from 25.1 cm
to 43.8 cm
, p < 0.0001 in diastole and from 8.6 cm
to 16.8 cm
, p < 0.001 in systole), and left ventricular diameter measured by M-mode echocardiography (from 26.2 mm to 32.6 mm, p < 0.0001 in diastole and from 17.1 mm to 20.6 mm, p < 0.001 in systole). The size of the left atrium also increased in transversal (from 29.2 mm to 33.6 mm, p < 0.01) but not in longitudinal diameter. In spite of a significant cardiac chamber dilatation over the 12-week period, left ventricular systolic functional variables (fractional shortening, FS % and ejection fraction, EF %), and also the left ventricular systolic and diastolic free wall thickness remained unchanged. In this study we demonstrated that chronic progressive volume overload resulted in gradual dilatation of the canine heart, and that the pathological process can be monitored successfully by serial echocardiography. We found that left atrial dilatation occurred without the development of mitral regurgitation and/or detectable left ventricular dysfunction.
151Sn Mössbauer spectroscopy was performed with tin triflate Sn(OTf)2 in order to determine its Mösbauer parameters for analytical purposes. The typical Mössbauer parameters at 80 K for crystalline Sn(OTf)2 are IS=4.01±0.02 mm/s and QS=1.20±0.04 mm/s and show that the stannous ion is at a site with less than cubic symmetry under perturbation of the crystal field effect.
This study aims to compare the impact of active allergic rhinitis on physical and cognitive abilities of trained allergic athletes to untrained allergic patients.
Cognitive, respiratory, and fitness functions were assessed before and after allergen exposure. Participants in both groups were provoked intranasally with ragweed allergen.
The group of athletes revealed significantly higher average values in peak inspiratory flow and fitness index before and after provocation. In neuropsychological assessments, athletes performed significantly better after allergen provocation in complex working memory capacity. Due to single acute allergen exposure, the size of the nasal cavity and nasal inspiratory peak flow significantly decreased in both groups. The physical performance of both groups did not change after provocation. Executive functions and complex working memory capacity of athletes significantly improved resulting from provocation.
A single-shot allergen in high dose might cause an increase in mental concentration, which was more pronounced in the group of athletes. This study indicates that acute exposure to allergen cannot affect the physical performance and may result in increased mental focus in patients with allergy notwithstanding the declining respiratory functions.