Einfluß der Hibernation auf die Vermehrung und Ausbreitung von Virus Aujeszky

Zusammenfassung Die artifizielle Hibernation hemmt und verzögert die Vermehrung und die Ausbreitung von Virus Aujeszky im ZNS. peripher infizierter Kaninchen erheblich. Hierdurch findet die frühere Beobachtung 1, wonach die Dauer der Inkubationsperiode und des Krankheitsverlaufes des M. Aujeszky bei Kaninchen beträchtlich verlängert ist, eine hinreichende Erklärung.     

Type of isoniazid (INH) acetylation determined in tuberculosis patients treated at the Institute of Tuberculosis and Lung Diseases in Warsaw during the years 1990-1997

The researched has dealt with the type of acetylation in 237 TB patients treated with standard course of chemotherapy with a dose of 300 mg of INH in period 1990-1997 in National Research Institute of Tuberculosis and Lung Disease in Warsaw Blood samples were taken before (time 0) and 1, 3, 6 and 24 h after drug administration. Plasma concentrations of isoniazid were determined with biological methods. Two indies of acetylation rate--I3 and C6 have been used to determine an acetylation type. Majority of the treated patients (68.8%) have shown fast type of INH acetylation. After similar dose of isoniazid different profile of absorption and excretion of the drug and significant differences (p < 0.01) in INH concentrations, acetylation rate and bioavailability between 163 fast and 74 slow acetylators have been observed. In plasma of 38.6% fast acetylators drug concentration 3 h after ingestion of a dose did not achieve the concentration of 1 mcg/ml. In plasma of 29.7% slow acetylators, concentrations of INH 6 h after ingestion were higher than 2 mcg/ml.     

Biochemical changes in the sublingual and submandibular glands after interruption of chorda tympani

The left chorda tympani nerve was interrupted through meatus acusticus externus in ten dogs. In total, 40 dog salivary glands (20 submandibular and 20 sublingual) innervated via chorda tympani were examined. Twenty glands (10 submandibular and 10 sublingual) on the left side were deprived of parasympathetic innervation by chordectomy, whereas contraleteral glands, on the right side, served as controls. Biochemical analysis showed that the interruption of chorda tympani did not cause any significant changes in the concentrations of eight enzymes investigated, i.e. lactate dehydrogenase, alkaline phosphatase, acid phosphatase, amylase, aspartate aminotransferase, alanine aminotransferase, gamma-glutamyltransferase and creatine kinase. There were no significant changes in the concentrations of most important extracellular ions (sodium, potassium, chloride and phosphorus) in the right glands, but the loss of parasympathetic innervation in the left glands was found to cause a statistically significant decrease in the concentration of potassium as intracellular cation and of phosphorus as extracellular anion.     

Progressive loss of lambda prophage recombinogenicity in UV-irradiated Escherichia coli: the role of RecBCD enzyme

RecBCD enzyme is involved in the radiation-induced process known as prophage inactivation. The process leads to the inability of lambda prophage to excise itself from the Escherichia coli chromosome via site-specific recombination. In this work we sought to further characterize the role of RecBCD enzyme in this process. In addition, we examined the ability of irradiated prophage to recombine with the infecting homologous phage. We used several E. coli mutants differentially altered in RecBCD's activities. The results showed that in the mutants carrying either recB2109 or recD1903, which do not exhibit significant nuclease activities, the prophage progressively loses its capacity for both site-specific and general recombination. In the recB268 null mutant, however, prophage recombinogenicity remained fully preserved. We also showed that the prophage unable to recombine retained its ability to complement the mutant infecting phage and that the recombination frequencies in phage x phage crosses were not affected by postirradiation incubation. Our results suggest that the helicase activity of RecBCD is responsible for the progressive loss of prophage recombinogenicity. This loss is most probably a consequence of the unsuccessful RecBCD-dependent recombinational repair of double-stranded breaks in the cell chromosome, during which some structures unsuitable for further recombination reactions may be produced.     

Ion beam transport in tissue-like media using the Monte Carlo code SHIELD-HIT

The development of the Monte Carlo code SHIELD-HIT (heavy ion transport) for the simulation of the transport of protons and heavier ions in tissue-like media is described. The code SHIELD-HIT, a spin-off of SHIELD (available as RSICC CCC-667), extends the transport of hadron cascades from standard targets to that of ions in arbitrary tissue-like materials, taking into account ionization energy-loss straggling and multiple Coulomb scattering effects. The consistency of the results obtained with SHIELD-HIT has been verified against experimental data and other existing Monte Carlo codes (PTRAN, PETRA), as well as with deterministic models for ion transport, comparing depth distributions of energy deposition by protons, 12C and 20Ne ions impinging on water. The SHIELD-HIT code yields distributions consistent with a proper treatment of nuclear inelastic collisions. Energy depositions up to and well beyond the Bragg peak due to nuclear fragmentations are well predicted. Satisfactory agreement is also found with experimental determinations of the number of fragments of a given type, as a function of depth in water, produced by 12C and 14N ions of 670 MeV u(-1), although less favourable agreement is observed for heavier projectiles such as 16O ions of the same energy. The calculated neutron spectra differential in energy and angle produced in a mimic of a Martian rock by irradiation with 12C ions of 290 MeV u(-1) also shows good agreement with experimental data. It is concluded that a careful analysis of stopping power data for different tissues is necessary for radiation therapy applications, since an incorrect estimation of the position of the Bragg peak might lead to a significant deviation from the prescribed dose in small target volumes. The results presented in this study indicate the usefulness of the SHIELD-HIT code for Monte Carlo simulations in the field of light ion radiation therapy.     

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.