Translational activation of encapsidated potato virus X RNA by coat protein phosphorylation

Previously we showed that encapsidated potato virus X (PVX) RNA is nontranslatable in vitro, but can be converted into a translatable form after binding to PVX particles of PVX-coded movement protein, the product of the first gene of triple gene block (TGBp1). Here we report that a similar effect occurs via in situ phosphorylation of the PVX coat protein (CP) by Ser/Thr protein kinase (PK) C, the mixture of casein kinases I and II or by cytoplasmic PK(s) from Nicotiana glutinosa leaves. Immunochemical analyses indicated that phosphorylation induced conformational changes in PVX CP. The N-terminal region of the PVX CP, rich in Ser and Thr residues, is exposed at the virion surface and can be removed by treatment with trypsin. We showed that (i) trypsin treatment removed the bulk of (32)P-radioactivity from in situ phosphorylated PVX CP, (ii) PVX containing N-terminally truncated CP (PVX-Ptd) failed to be translationally activated by phosphorylation, and (iii) the specific infectivity of PVX-Ptd was reduced. However, the PVX-Ptd RNA remained intact and PVX-Ptd could be translationally activated by the PVX MP TGBp1. We hypothesize that phosphorylation of the parental PVX by cytoplasmic PK(s) in vivo renders PVX RNA translatable in primary inoculated cells, whereas translational activation of the progeny virions destined for plasmodesmata trafficking is triggered by TGBp1.     

Protein, essential amino acids and glycine requirements of the growing gosling (Anser cireneus)

The dietary requirements for protein and amino acids of the growing gosling (0-7 weeks) were calculated according to body composition, maintenance needs and the absorption rate of amino acids from feeds. The diets were formulated by least-cost linear programming, using the calculated requirements for amino acids, with or without minimal glycine + serine requirements. The diets formulated without minimal requirements of glycine + serine were supplemented with various amounts of glycine, and fed to growing goslings. The calculated requirements for protein and essential amino acids were lower than those suggested for growing broilers and turkeys. The requirements (g/MJ metabolizable energy) at 0-2, 2-4 and 4-7 weeks of age respectively, were: lysine 0.88, 0.48, 0.43; methionine + cystine 0.48, 0.38, 0.29; protein 14.5, 9.3, 7.6. The goslings did not respond to glycine supplementation of the diet.     

Antiarrhythmic activity of heptacaine and some of its derivatives

In the evaluation of experimental antiarrhythmic effect in guinea pigs, by a method of antagonizing ouabain arrhythmogenity, there was found a maximum effect of N-[2-(2-heptyloxy-phenylcarbamoyloxy)-ethyl]-piperidinium-chloride (heptacaine). The shortening or prolongation of the alkoxy substitution in the ortho-position, or the shift of hexyloxy substitution to the meta- or para-position, respectively, causes a decrease in activity. Negative chronotropic effect of heptacaine is increased and prolonged during the 5th min after acute i.v. application. The effect of lidocaine was short-lasting and decreased. In antagonizing experimental adrenaline (epinephrine) arrhythmogenity, heptacaine showed an important antiarrhythmic effect, too. In the relative hypotensive activity evaluation, there was an important effect in the 1st min after i.v. application and this decreased to the same values as those of lidocaine in the 5th min. Hypotensive effect evaluation of lidocaine and heptacaine after higher doses than therapeutic ones showed that the hypotensive effect of heptacaine takes place at the same rate as that of lidocaine and by the 10th min reaches control values. Values of experimental partition coefficient showed an increase in relation to prolongation of ortho-alkoxy substitution in the sequence: propoxy less than pentyloxy less than heptyloxy less than nonyloxy. Submaximal value by the heptacaine may reflect an optimal hydrophylic-lipophylic balance of its molecule. But in the evaluation on antiouabain effect and partition coefficient, there is no simple direct correlation in structure-activity relationship.     

Familial Creutzfeldt–Jakob disease homozygous to the E200K mutation: clinical characteristics and disease course

Journal of Neurology - To characterize the demographic, clinical features and disease course of familial Creutzfeldt–Jakob disease (fCJD) patients homozygous to the E200K mutation. The...     

The Neuropeptide Y (NPY)-ergic System is Associated with Behavioral Resilience to Stress Exposure in an Animal Model of Post-Traumatic Stress Disorder

Converging evidence implicates the regulatory neuropeptide Y (NPY) in anxiety- and depression-related behaviors. The present study sought to assess whether there is an association between the magnitude of behavioral responses to stress and patterns of NPY in selected brain areas, and subsequently, whether pharmacological manipulations of NPY levels affect behavior in an animal model of PTSD. Animals were exposed to predator-scent stress for 15 min. Behaviors were assessed with the elevated plus maze and acoustic startle response tests 7 days later. Preset cutoff criteria classified exposed animals according to their individual behavioral responses. NPY protein levels were assessed in specific brain regions 8 days after the exposure. The behavioral effects of NPY agonist, NPY-Y1-receptor antagonist, or placebo administered centrally 1 h post-exposure were evaluated in the same manner. Immunohistochemical technique was used to detect the expression of the NPY, NPY-Y1 receptor, brain-derived neurotrophic factor, and GR 1 day after the behavioral tests. Animals whose behavior was extremely disrupted (EBR) selectively displayed significant downregulation of NPY in the hippocampus, periaqueductal gray, and amygdala, compared with animals whose behavior was minimally (MBR) or partially (PBR) disrupted, and with unexposed controls. One-hour post-exposure treatment with NPY significantly reduced prevalence rates of EBR and reduced trauma-cue freezing responses, compared with vehicle controls. The distinctive pattern of NPY downregulation that correlated with EBR as well as the resounding behavioral effects of pharmacological manipulation of NPY indicates an intimate association between NPY and behavioral responses to stress, and potentially between molecular and psychopathological processes, which underlie the observed changes in behavior. The protective qualities attributed to NPY are supported by the extreme reduction of its expression in animals severely affected by the stressor and imply a role in promoting resilience and/or recovery.     

Microinfusion of a corticotrophin-releasing hormone receptor 1 antisense oligodeoxynucleotide into the dorsal hippocampus attenuates stress responses at specific times after stress exposure

Corticotrophin-releasing hormone (CRH) plays a key role in the adjustment of neuroendocrine and behavioural adaptations to stress. Dysregulation in CRH systems has been implicated in a variety of stress-related psychiatric disorders such as post-traumatic stress disorder (PTSD). The present study examined the relationship between stress-induced PTSD-like behavioural response patterns and levels of CRH, CRH receptor (CHR-R)1 and phosphorylated extracellular signal-regulated kinase (pERK1/2) in the rat hippocampus subregions. The effects of pharmacological manipulations on behavioural, physiological and response patterns of brain-derived neurotrophic factor (BDNF) and pERK1/2 expression using a CRH receptor (CRH-R)1-antisense oligodeoxynucleotide (CRH-R1-ASODN) were evaluated. CRH and CRH-R1 mRNA and pERK1/2 protein levels were assessed in the hippocampus subregions 7 days after exposure to predator scent stress (PSS). The effects of CRH-ASODN versus CRH-Scrambled-ODN microinfusion to the dorsal hippocampus either 1 h or 48 h post-exposure on behavioural tests (elevated plus maze and acoustic startle response) were evaluated 7 days later, 14 days after PSS exposure. Localised brain expression of BDNF and ERK1/2 was subsequently assessed. All data were analysed in relation to individual behaviour patterns. A distinct pattern associated with extreme behavioural response (EBR) was revealed in the bioassay of behavioural study subjects, classified according to their individual patterns of behavioural response at 7 days. These EBR individuals displayed significantly higher CRH and CRH-R1 mRNA levels in the CA1 and CA3 areas, mediating down-regulation of pERK1/2 protein levels. Microinfusion of a CRH-R1-ASODN into the dorsal hippocampus 48 h after stress exposure, although not immediately after exposure (1 h), significantly reduced behavioural disruption and was associated with concomitant up-regulation of BDNF and pERK1/2 protein levels compared to CRH-R1-Scrambled -ODN controls. CRH/CRH-R1 is actively involved in the neurobiological response to predator scent stress processes and thus warrants further study as a potential therapeutic avenue for the treatment of anxiety-related disorders.