Determinants of posttraumatic adjustment in adolescents from Sarajevo who experienced war

The purpose of this study was to examine risk and protective factors of postwar adjustment among adolescents from Sarajevo who have been exposed to war traumas during the war in Bosnia and Herzegovina. More specifically, we wanted to examine differential linkages between Posttraumatic Stress Disorder (PTSD) symptoms and depression (as outcomes) and (a) war traumas, (b) individual and socioenvironmental factors, and (c) cognitive appraisals and coping mechanisms. Results of hierarchical multiple regression analyses indicate that dimensions of war traumas, individual characteristics, and cognitive appraisals and coping mechanisms play a significant role in determining who will have more serious PTSD symptoms. Although individual and socioenvironmental factors are the strongest predictors of depression, dimensions of war traumas also are significantly correlated with depressive symptoms. Common risk factors for more serious depression and PTSD symptoms in postwar adjustment were female gender and low optimism. While the strongest predictor of posttraumatic stress reactions (PTSR) was trauma experience in the category of loss, the strongest predictor of depressive symptoms was female gender.     

Distinct pathways for constitutive endocytosis of fully conformed and non-conformed L(d) molecules

PROBLEM: To characterize the constitutive internalization of major histocompatibility complex (MHC) class I molecules, we have studied the expression of completely conformed (full) and unconformed (empty) L(d) molecules on non-polarized murine P815 cells. METHODS OF STUDY: Spontaneous endocytosis of L(d) molecules was induced by cycloheximide, an inhibitor of protein synthesis, and their disappearance from the cell surface was determined by flow cytometry. In order to investigate the mechanism of internalization, a palette of inhibitors of endocytosis and vesicular transport was used. RESULTS: Inhibitors of clathrine endocytosis did not influence the internalization of L(d) molecules. Inhibitors of caveolar endocytosis and inhibitors of endolysosomal degradation prevented down-regulation of empty, but not of full L(d) molecules. CONCLUSIONS: Empty L(d) molecules are internalized mostly by caveolar endocytosis and full L(d) molecules use a different pathway, neither clathrine-mediated nor caveolar. After internalization, full L(d) molecules are probably degraded and empty L(d) molecules recycle between endosomal compartment and the cell surface before they enter into the degradation compartment.     

The relationship between muscle kinetic parameters and kinematic variables in a complex movement

Summary Kinematic variables of the vertical jump (jumping height, jump phase durations and joint angles) were measured on 39 male physical education students. In addition, kinetic parameters of the hip and knee extensors, and of the plantar flexors (maxima voluntary force and its rate of development) were recorded on the same subjects, in isometric conditions. The results demonstrated significant positive correlations between kinetic parameters of the active muscle groups and jumping height (r=0.217−0.464). The dominant effect on these correlations was due to the knee extensors. Correlations between these parameters and the duration of the jump phases were much weaker. Correlation coefficients between kinetic parameters and limb angles in the lowest body position showed that fast force production in one muscle group was related to a significant decrease in the joint angles of distant body segments. Multiple correlation coefficients between leg extensor parameters and kinematic variables (ranging between 0.256 for the duration of the counter-movement phase and 0.616 for jump height) suggested that kinetic parameters could explain more than a quarter of the variability of this complex human movement. Therefore, the conclusion was drawn that an extended set of measurements of the relevant musculo-skeletal system parameters could predict a considerable amount of the variability of human movement. However, high correlation coefficients between the same kinetic parameters of different muscle groups suggest that not all active muscle groups have to be included in the measurements.     

Pathologic calcification in patients with chronic kidney failure

Pathologic, extraskeletal calcifications are frequently seen in chronic renal failure patients. According to pathogenesis, they can be classified to dystrophic and metastatic, and according to localization to visceral and non-visceral. As to physicochemical composition, two major types have been characterized: hydroxyapatite and amorphous calcium magnesium phosphate. The pathogenesis is not completely understood. Today, there are convincing data showing that calcification is an active, regulated process rather than a passive accumulation of calcium and phosphate. Control of calcium, phosphate and parathormone level, correction of metabolic acidosis and adequate dialysis are important in the prevention and treatment of pathologic calcification.     

Ageing is associated with a decrease in the number of sarcolemmal ATP-sensitive K+ channels in a gender-dependent manner

The opening of sarcolemmal K(ATP) channels is considered to be an important endogenous cardioprotective mechanism. On the other hand, age-dependent changes in the myocardial susceptibility to ischemia and hypoxia have been observed in different species, including humans. Here, we have hypothesized that aging might be associated with the changes in sarcolemmal K(ATP) channels. Therefore, the main objective of the present study was to establish whether aging changes expression of cardiac sarcolemmal ATP-sensitive K+ (K(ATP)) channels. RT-PCR using primers specific for K(ATP) channel subunits, Kir6.2, Kir6.1 and SUR2A subunits was performed using total RNA from guinea-pig ventricular tissue. Whole cell electrophysiology was done on isolated guinea-pig ventricular cardiomyocytes. Western blotting using anti-Kir6.2 and anti-SUR2A antibodies was performed on cardiac membrane fraction. Tissue and cells were harvested from young and old, male and female guinea-pigs. RT-PCR analysis did not reveal significant age-related changes in levels of Kir6.1 or Kir6.2 mRNAs. However, levels of SUR2A were significantly lower in old than in young females. Such age-differences were not observed with cardiac tissue from male animals. In both old and young males, pinacidil (100 microM) induced outward currents. The difference between current density of pinacidil-sensitive component in females, but not males, was statistically significant. Western blotting analysis revealed higher levels of Kir6.2 and SUR2A proteins in cardiac membrane fraction from young than old females. The present study demonstrates that in females, but not males, aging is associated with decrease in number of cardiac K(ATP) channels which is due to decrease in levels of the SUR2A subunit.     

Experimental determination of electron source parameters for accurate Monte Carlo calculation of large field electron therapy

Extensive work has been performed to validate Monte Carlo models for both photon and electron beams under standard conditions. However, for large field electron beam therapy, Monte Carlo simulations have not been able to provide good agreement when compared to the measured dose distributions. Since the accuracy of the calculation relies heavily on the geometry parameters of the linear accelerator and the characteristics of the incident electron beam, it is crucial to have a complete comprehension of these independent factors. In this work, the electron focal spot size for a CL21EX linac with various energies (6, 9, 12 and 16 MeV) was measured with a slit camera composed of alternating lead and paper sheets. For all the energies investigated, the electron focal spot is found to be elliptical and has a full width at half maximum (FWHM) ranging from 1.69 mm to 2.24 mm. A shift with respect to the crosshair was associated with each measured focal spot. In addition, we present an improved result for the large field in-air profile by utilizing a proposed divergent beam model in conjunction with the experimental focal spot dimension. This model can potentially provide a solution to the Monte Carlo validation of large field electron beam therapy.     

Toxoplasmosis--morphologic diagnosis options for the ever topical disease

It has been estimated that 60 percent of people in Croatia will be infected with Toxoplasma gondii until the age of 40. The infection is most frequently asymptomatic, or presented with an lymphadenitis, acute infection during pregnancy that can cause serious damage to the fetus in 10-30 percent, depending on the gestation phase. After acute infection Toxoplasma gondii resides in the body for life, being controlled by cellular immunity. In case of the immune system compromise, reactivation of the infection and serious inflammatory changes, mostly in the central nervous system, occur. Prenatal infection and serious clinical picture in immunocompromised patients classify toxoplasmosis among ever topical infections, thus all research toward better understanding of its pathogenesis in immunocompetent patients is of utmost importance. The aim of the study was to systematically analyze the morphology and changes in cytologic smears of lymph nodes from patients acutely infected with Toxoplasma gondii, and to morphologically visualize Toxoplasma gondii in the lymph nodes by use of specific monoclonal antibodies. For this purpose, 30 aspirates of lymph nodes of patients who had definite serologic evidence for and clinical picture of acute toxoplasma infection were analyzed by use of classic cytology and immunocytochemistry methods. Results confirmed a recognizable cytologic picture of reactive hyperplasia of follicular center cells and granulomatous inflammation, with a unique finding of Toxoplasma gondii tachyzoite in lymphatic cells.