Investigation of the protective effect of anzer propolis in cerebral ischemia-reperfusion injury

OBJECTIVE

Globally, stroke is the leading cause of disability and death. With the use of thrombolytic therapy, reperfusion injury, and its consequences came to the fore. We aimed to find out how anzer propolis, which can only be obtained in Turkey's Eastern Black Sea region, affected ischemia-reperfusion injury using biochemical and histological techniques.

MATERIALS AND METHODS

32 female Wistar albino rats were divided into 4 groups, including a control group. Three of the groups underwent 30 minutes of induced ischemia via clamping of the common carotid artery, followed by ischemia-reperfusion injury through the release of the clamp. One group received no treatment, another received oral administration of 100 mg/kg of anzer propolis one hour before surgery, and the third group received oral administration of 40 mg/kg of acetylsalicylic acid just before surgery. Histopathological examination assessed apoptosis and tissue necrosis, while serum and brain tissue were evaluated for levels of nerve growth factor (NGF), Interlokin 1β (IL-1β), Interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), total antioxidant capacity (TAS), and total oxidant capacity (TOS).

RESULTS

Anzer propolis and acetylsalicylic acid significantly reduced hyperemia in vessels, vacuolization in neurons, glial cell infiltration, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) positivity. The anzer propolis group had the highest NGF levels. The anzer propolis and acetylsalicylic acid groups had lower levels of TNF-a and IL-6 in the brain tissue than the ischemia-reperfusion group, while TAS levels were higher.

CONCLUSIONS

The findings obtained in this study suggest that anzer propolis has a neuroprotective effect against ischemia-reperfusion injury and will have beneficial effects on neurodegeneration. We believe our findings will contribute to the clinical treatment of ischemia-reperfusion injury.

Application of UN method to neutron transport equation in slab geometry using HG phase function

The steady-state one speed neutron transport equation without sources is studied in slab geometry using Henyey-Greenstein scattering function. The critical thicknesses are calculated for various c (mean number of secondary neutrons per collision) and t scattering parameters using UN method and obtained values are compared with PN method. All the numerical results for different collision scattering functions and t parameters of UN and PN methods are presented in the tables.

Criticality calculations with PN approximation for certain scattering parameters of Anlı-Güngör and Henyey-Greenstein phase functions in spherical geometry

PN approximation is applied to neutron transport equation in spherical geometry using Anlı-Güngör (AG) and Henyey-Greenstein (HG) phase functions. These phase functions are used for calculating critical radius and results of PN approximation obtained from AG and HG phase functions are compared with each other for different collision scattering function. The numerical results obtained from AG and HG phase functions are presented in the tables and these results are compared.

T 1 and U 1 approximations to neutron transport equation in one-dimensional spherical geometry

The diffusion lengths for one-speed neutrons are calculated by solving transport equation in one-dimensional spherical geometry. The pseudo-slab transport equation is obtained using a reasonable approach. The neutron angular flux is expanded in a series of both the Chebyshev polynomials of first and second kinds. Then analytic and numerical results for asymptotic relaxation length are obtained by applying first order approximations to the transport equation and they are compared with each other.

Calculation of the critical thickness for one-speed neutrons in a reflected slab with backward and forward scattering using modified T N method

The reflected critical slab problem is investigated in one-speed neutron transport theory for reflecting boundary conditions. The neutron angular flux is expanded in a series of first kind Chebyshev polynomials and isotropic, backward and forward scattering kernel is used as the scattering function. The critical sizes for one-speed neutrons in a uniform finite slab surrounded by identical reflectors from both sides are calculated for various values of the collision parameter, backward and forward scattering and reflection coefficient. Numerical values calculated for the critical slab are presented in the tables and are found to be in good agreement with literature values.

U 1 and P 1 approximations to neutron transport equation for diffusion length calculation

U 1 and P 1 approximations are used for the calculation of asymptotic relaxation length in one-dimensional neutron transport equation. The approximation methods are applied to anisotropic neutron transport equation with backward and forward scattering. The methods are based on the series expansion of the neutron angular flux in terms of the Chebyshev polynomials of second kind and Legendre polynomials. By applying the first order approximation to the transport equation, asymptotic relaxation lengths are calculated. Numerical results obtained from both methods are compared with each other.

Matrix metalloproteinase, vitamin A and methylprednisolone effects on experimentally induced amyloid arthropathy

We evaluated the role of some matrix metalloproteinases (MMPs) in enhancing the effect of vitamin A and the inhibiting effect of methylprednisolone on amyloid arthropathy in brown layer chicks. We used 100 one-day-old Isa brown layer chicks. The chicks were allocated to one of four groups as follows: negative control group (I), vitamin A group (II), positive control group (III) and methylprednisolone group (IV). Amyloid arthropathy was induced by injections of complete Freund's adjuvant into the left intertarsal joints of the chicks. Serum vitamin A and tissue MMP (MMP-1, MMP-2, MMP-9) levels were measured and differences among the groups were investigated. Serum vitamin A rates (μg/dl) were: 63.57 ± 4.10, 47.13 ± 10.62, 53.26 ± 10.79, 98.48 ± 8.20 in groups I, II, III and IV, respectively (p < 0.001). MMP-1, MMP-2 and MMP-9 levels were evaluated in tissues from the chickens with amyloid arthropathy. Methylprednisolone significantly suppressed the release of MMP-1 and MMP-2, and increased the release of MMP-9 in birds with amyloid arthropathy. In addition, vitamin A significantly increased the release of MMP-1, MMP-2 and MMP-9.

Application of the TN method to critical slab problem for one-speed neutrons with forward and backward scattering and efficiency of reflection coefficient

The one-speed neutron transport equation which includes isotropic forward and backward scattering has been studied using the TN approximation. Critical thicknesses for different values of the reflection coefficient R and c values have been calculated. The study shows that the TN method gives nearly the same results as the PN approximation in one-dimensional geometry. The results obtained in this study are presented in tables and are compared with PN approximation results.

U1 approximation to the neutron transport equation and calculation of the asymptotic relaxation length

The U1 approximation is used to determine the asymptotic relaxation length (diffusion length) for one-speed neutrons in a homogeneous slab. The method is based on the series expansion of the neutron angular flux in terms of the Chebyshev polynomials of second kind and then calculating the diffusion length by applying the first order approximation to transport equation. Analytic and numerical results are obtained for the diffusion length and compared with the ones obtained from the method of separation of variables and simple diffusion theory (P1 approximation).

Application of the Chebyshev polynomial (T N and U N ) approximation to reflected slab geometry in the neutron transport equation and computation of critical half thicknesses

The transport of one-speed neutrons has been studied in isotropically scattering slab using ultraspherical polynomial approximation whose sub-cases are spherical harmonics approximation and Chebyshev polynomial approximation of first and second kind with reflective boundaries. An integral equation for the total flux has been derived and solved numerically for different values of c and reflection coefficients. In the solution, Marshak type vacuum boundary conditions were used. The critical thicknesses obtained by the Chebyshev polynomial method are in good agreement with literature values. Computations were made by using the TN, UN and PN approximations for comparison.

Chebyshev polynomial (TN ) approximation to neutron transport theory and application to the critical slab problem

The critical slab problem has been studied in the one-speed neutron transport equation with isotropic scattering by using the first kind of Chebyshev Polynomials. The moment criticality solutions were obtained for the uniform finite slab using Mark and Marshak type vacuum boundary conditions. The results obtained by this approximation are presented in tables which also include the results obtained by the PN method for comparison.

Efficiency of reflection coefficients in the isotropic neutron transport equation and computation of the critical-half thicknesses

The critical slab problem of the reflected isotropic one-speed neutron transport equation is solved with the Chebyshev polynomial approximation. The efficiency of the reflection coefficient, R, in the neutron transport equation is obtained for different c values. For the solution, the Mark boundary condition is used. The values obtained from this approximation are compared with results obtained by the spherical harmonics method.

Modified Chebyshev polynomial (U N ) approximation in the neutron transport theory and computation of critical half thicknesses

A general theoretical scheme for the UN method and the evolution of a general eigenvalue spectrum are described. The applicability of UN method to one dimensional slab geometry neutron transport problems is discussed. The eigenvalue spectrum is calculated for isotropic scattering with different values of the parameter c, the mean number of secondary neutrons per collision, known as the fundamental eigenvalue. Then the critical slab problem has been studied. The critical half thicknesses are computed for different values of c. For the solution, Mark and Marshak boundary conditions are used. Results are obtained for both, UN and PN approximations for comparison.

Application of the UN approximation to the neutron transport equation in slab geometry

The critical slab problem of the one-speed and one dimensional neutron transport equation for an isotropic homogeneous medium was studied by using the Chebyshev polynomial approximation, i. e. UN method. The results obtained by the UN method for various c values, using the two type boundary conditions which are known as Mark and Marshak boundary conditions, are presented in tables. The tables also include the results obtained by the PN method for comparison.