O-GlcNAcylation of key nuclear and cytoskeletal proteins: reciprocity with O-phosphorylation and putative roles in protein multimerization

BACKGROUND: Registered mortality from cryptogenic fibrosing alveolitis (CFA) in England and Wales has increased substantially since the specific International Classification of Diseases code for CFA was introduced in 1979. However, since a significant proportion of deaths from CFA are misclassified as post inflammatory fibrosis (PIF), it is possible that the observed rise in CFA mortality is due to diagnostic transfer from this code. To investigate this, and to assess mortality trends in other countries, annual CFA and PIF mortality data from England and Wales, USA, Australia, Scotland, Canada, New Zealand, and Germany were analysed. METHODS: Crude annual mortality rates were calculated and rates standardised by Poisson regression to allow assessment of changes over time and comparison between countries, sexes, and age groups. The relative trends in mortality from CFA and PIF were assessed by calculating the annual ratio of CFA to PIF deaths. RESULTS: Men were more likely than women to die from both CFA and PIF in all countries. The highest standardised CFA mortality rate occurred in England and Wales, and the lowest in Germany. Since 1979 mortality from CFA has increased in England and Wales, Australia, Scotland and Canada, but there was no trend in CFA mortality in New Zealand or Germany. In the USA mortality from CFA was low and has fallen. Mortality from PIF increased in all countries except New Zealand and Germany, and the highest PIF mortality, together with the greatest increase over time, was seen in the USA. Changes over time in the annual ratio of CFA to PIF deaths in all countries were small, implying that diagnostic transfer is not a major cause of the increasing CFA mortality. CONCLUSIONS: Mortality from CFA continues to increase in England and Wales and in many other countries. Diagnostic transfer from PIF does not appear to be a major cause of this.     

Effect of glutamine supplementation on changes in the immune system induced by repeated exercise

The ability of lymphocytes to proliferate and generate lymphokine activated killer (LAK) cell activity in vitro is dependent on glutamine. In relation to intense exercise the lymphocyte concentration, the proliferative response, the natural killer and LAK cell activity, and the plasma glutamine concentration decline. It has been hypothesized that in relation to physical activity a lack of glutamine may temporarily affect the function of the immune system. PURPOSE: The purpose of this study was to examine the influence of glutamine supplementation on exercise-induced immune changes. METHODS: In a randomized cross-over placebo-controlled study, eight healthy male subjects performed three bouts of ergometer bicycle exercise lasting 60, 45, and 30 min at 75% of their VO2max separated by 2 h of rest. RESULTS: The arterial plasma glutamine concentration declined from 508 +/- 35 (pre-exercise) to 402 +/- 38 microM (2 h after the last exercise bout) in the placebo trial and was maintained above pre-exercise levels in the glutamine supplementation trial. The numbers of circulating lymphocytes and the phytohemagglutinin-stimulated lymphocyte proliferative response declined 2 h after, respectively, during each bout of exercise, whereas the LAK cell activity declined 2 h after the third bout. Glutamine supplementation in vivo, given in the described doses at the specific times, did not influence these changes. CONCLUSION: The present study does not appear to support the hypothesis that those aspects of postexercise immune changes studied are caused by decreased plasma glutamine concentrations.     

Comorbidity of DSM-IV personality disorders in a nonclinical sample

An ABC-transporter of Arabidopsis thaliana exhibiting high sequence similarity to the human (MRP1) and yeast (YCF1) glutathione-conjugate transporters has been analysed and used to complement a cadmium-sensitive yeast mutant (DTY168) that also lacks glutathione-conjugate transport activity. Comparison of the hydrophobicity plots of this A. thaliana MRP-like protein with MRP1 and YCF1 demonstrates that the transmembrane domains are conserved, even at the N-terminus where sequence identity is low. Cadmium resistance is partially restored in the complemented ycf1 mutant, and glutathione-conjugate transport activity can be observed as well. The kinetic properties of the A. thaliana MRP-like protein (AtMRP3) are very similar to those previously described for the vacuolar glutathione-conjugate transporter of barley and mung bean. Furthermore, a hitherto undescribed ATP-dependent transport activity could be correlated with the gene product, i.e. vesicles isolated from the complemented yeast, but not from DTY168 or the wild type, take up the chlorophyll catabolite Bn-NCC-1. The results indicate that the product of the MRP-like gene of A. thaliana is capable of mediating the transport of the two different classes of compounds.     

Prognostic value of plasma catecholamines, plasma renin activity, and plasma atrial natriuretic peptide at rest and during exercise in congestive heart failure: comparison with clinical evaluation, ejection fraction, and exercise capacity

Survival in congestive heart failure is related to plasma catecholamines and atrial natriuretic peptide at rest, but the prognostic importance of changes during exercise is unknown. The aim of this study was to evaluate the prognostic value of catecholamines and atrial natriuretic peptide at rest and during maximal exercise in congestive heart failure, and to compare it to clinical and exercise test variables and left ventricular ejection fraction. One hundred ninety consecutive patients (136 men and 54 women; median age, 66 years; range, 42-75 years) with clinically stable congestive heart failure were included. Sixteen patients were in New York Heart Association class I, 87 in class II, 83 in class III, and 4 in class IV. Left ventricular ejection fraction was 0.30 (range, 0.06-0.74). Total survival after 1 year was 79%, after 2 years, it was 68%. Prognostic variables at univariate analysis were: plasma noradrenaline at rest (P < .0001), plasma adrenaline at rest (P = .049), and atrial natriuretic peptide at rest (P = .016). During exercise, plasma catecholamines and plasma atrial natriuretic peptide increased significantly; the change, however, was not related to survival. Six variables carried significant, independent prognostic information in a multivariate analysis: left ventricular ejection fraction (P = .03), plasma noradrenaline at rest (P = .009), New York Heart Association class III + IV (P = .005), increase in heart rate during exercise < or = 35 min-1 (P < .0001), serum creatinine > 121 mumol/L (P = .004), and serum urea > 7.6 mmol/L (P = .007). Patients with congestive heart failure have a poor survival despite intensive medical treatment. Plasma catecholamines and plasma atrial natriuretic peptide are elevated at rest and rises further during exercise; the increase, however, is not related to mortality. Plasma noradrenaline at rest contributes with further prognostic information despite knowledge of clinical and exercise variables and was the only neurohormonal variable with independent, significant prognostic information on survival.     

Evidence for involvement of ventral tegmental area cyclic AMP systems in behavioral sensitization to psychostimulants

The present study investigated the role of ventral tegmental area (VTA) cyclic AMP (cAMP) systems in the behavioral sensitivity to psychostimulants in male Sprague-Dawley rats. Bilateral microinjections of cholera toxin (CTX) into the VTA (50-500 ng/500 nl/side) dose-dependently sensitized animals to the locomotor stimulant effects of systemic d-amphetamine, cocaine and apomorphine, but were without effects on morphine-induced locomotion 24 hr after microinjection. The CTX-induced behavioral sensitization to amphetamine was even greater 72 hr after microinjection, but was no longer present 14 days after intra-VTA CTX pretreatment. Coadministration of the cAMP-dependent protein kinase inhibitor H8 into the VTA blocked CTX-induced sensitization to amphetamine, suggesting that the sensitization is dependent on phosphorylation events in the VTA mediated by cAMP-dependent protein kinase. Pretreatment with CTX did not enhance amphetamine-induced dopamine release in the nucleus accumbens relative to saline controls 24 hr after microinjection. A single bilateral injection of d-amphetamine into the VTA (5 micrograms/side) produced a significant sensitization to systemic amphetamine challenge 72 hr later, and this effect was also blocked by coadministration of H8 into the VTA. These results extend previous studies which have established the importance of the VTA in the development of behavioral sensitization and suggest that cAMP systems may play a crucial role in this neuroadaptive process.     

Vasorelaxation of rat thoracic aorta caused by 14-deoxyandrographolide

1. The pharmacological effects of 14-deoxyandrographolide on rat isolated thoracic aorta were examined. 2. 14-Deoxyandrographolide (2.5-120 mumol/L) inhibited contractions induced by phenylephrine (PE; 0.1 mumol/L) and high K+ (80 mmol/L) in a concentration-dependent manner in endothelium-intact aorta. The effect was attenuated in endothelium-denuded aorta without modifying the maximal response. Like verapamil, 14-deoxyandrographolide produced a much greater vasorelaxant effect in aorta precontracted by KCl than by PE. 14-Deoxyandrographolide (20-60 mumol/L) also inhibited responses of the rat aorta to PE. 3. In Ca(2+)-free medium (KCl 55 mmol/L), 14-deoxyandrographolide (20-80 mumol/L) antagonized Ca(2+)-induced vasocontraction in a concentration-dependent manner and transient contractions induced by both caffeine (10 mmol/L) and nor-adrenaline (1 mumol/L) were suppressed or almost abolished by 14-deoxyandrographolide. 4. The vasorelaxant effect of 14-deoxyandrographolide was partially antagonized by NG-nitro-L-arginine methyl ester (25 mumol/L), a specific and competitive nitric oxide synthase (NOS) inhibitor, and methylene blue (10 mumol/L), a soluble guanylate cyclase inhibitor, but was not affected by indomethacin (20 mumol/L), a cyclo-oxygenase inhibitor, or glibenclamide (10 mumol/L), an ATP-sensitive K(+)-channel blocker. 5. These results suggest that the vasorelaxant activity of 14-deoxyandrographolide may be mediated via the activation of NOS and guanylate cyclase, as well as the blockade of Ca2+ influx through both voltage- and receptor-operated Ca2+ channels.     

Mcm2 and Mcm3 are constitutive nuclear proteins that exhibit distinct isoforms and bind chromatin during specific cell cycle stages of Saccharomyces cerevisiae

The Mcm2-7 proteins are a family of conserved proteins whose functions are essential for the initiation of DNA synthesis in all eukaryotes. These patients are constitutively present in high abundance in actively proliferating cells. In Saccharomyces cerevisiae, the intracellular concentrations of Mcms are between 100 and 500 times the number of replication origins. However, these proteins are limiting for the initiation of DNA synthesis at replication origins. Our studies indicate that only a small fraction of Mcm2 and Mcm3 tightly associates with chromatin, from late M phase to the beginning of the S phase. The rest of the Mcm2 and Mcm3 proteins are disturbed to both the cytoplasm and nucleoplasm in relatively constant levels throughout the cell cycle. We also show that S. cerevisiae Mcm3 is a phosphoprotein that exists in multiple isoforms and that distinct isoforms of Mcm2 and Mcm3 can be detected at specific stages of the cell cycle. These results suggest that the localization and function of the Mcm proteins are regulated by posttranslational phosphorylation in a manner that is consistent with a role for the Mcm proteins in restricting DNA replication to once per cell cycle.     

Spirochetes from digital dermatitis lesions in cattle are closely related to treponemes associated with human periodontitis

Digital dermatitis (DD), first described in 1974 by Cheli and Mortellaro (R. Cheli and C. Mortellaro, p. 208-213, in Proceedings of the 8th International Conference on Diseases of Cattle, 1974), is a major problem in diary cows and beef cattle causing significant economic losses worldwide. Lesions are typically found at the volar skin proximal to the heel bulbs. Microscopic examination of biopsies or touch preparations of these lesions revealed a variety of different bacterial morphotypes including significant numbers of spirochetes which often represent the predominant morphotype. We used comparative 16S rRNA sequence analysis to determine the diversity and phylogeny of these hitherto unclassified DD spirochetes. Results indicate that those lesions looked at so far contained at least five spirochetal phylotypes, all clustering within the genus Treponema. Phylotype DDKL-4 was nearly identical (99.4% similarity) to that of a nonpathogenic human treponeme, T. phagedenis. Two phylotypes DDKL-3 and DDKL-13 were closely related to those from treponemes commonly found in human periodontitis lesions, i.e., T. denticola and T. vincetii, exhibiting 95 and 98% similarity, respectively. The other two phylotypes, DDKL-12 and DDKL-20, had no close relatives to any cultivable treponemal species but clustered to previously described group IV oral treponemes. Preliminary analysis using in situ hybridization with fluorescently labeled oligonucleotide probes against smears from DD biopsies revealed that from all lesions analyzed so far, T. denticola-like spirochetes were detected in the highest proportion of all spirochetal morphotypes.