Escherichia coli peptide methionine sulfoxide reductase gene:regulation of expression and role in protecting against oxidative damage

This is the publisher's version, also available electronically from "http://jb.asm.org".The Escherichia coli peptide methionine sulfoxide reductase gene (msrA) encodes a single-subunit polypeptide of 212 amino acid residues (M. A. Rahman, H. Nelson, H. Weissbach, and N. Brot, J. Biol. Chem. 267:15549-15551, 1992). RNA blot analysis showed that the gene is transcribed into an mRNA of about 850 nucleotides. The promoter region was characterized, and the transcription initiation site was identified by primer extension. The synthesis of the MsrA protein increased about threefold in a growth-phase-dependent fashion. In an attempt to define the in vivo role of msrA, a chromosomal disruption was constructed. This mutant was more sensitive to oxidative stress, suggesting that oxidation of methionine in proteins plays an important role in oxidative damage

Cutaneous nociception and neurogenic inflammation evoked by PACAP38 and VIP

Pituitary adenylate cyclase-activating peptide-38 (PACAP38) and vasoactive intestinal peptide (VIP) belong to the same secretin–glucagon superfamily and are present in nerve fibers in dura and skin. Using a model of acute cutaneous pain we explored differences in pain perception and vasomotor responses between PACAP38 and VIP in 16 healthy volunteers in a double-blind, placebo-controlled, crossover study. All participants received intradermal injections of 200 pmol PACAP38, 200 pmol VIP and placebo into the volar forearm. Measurements included pain intensity on a visual analog scale (VAS), blood flow by laser Doppler flowmetry, visual flare and wheal. Pain intensities after PACAP38 and VIP were mild and limited to a short time of about 100 s after injection. The area under the VAS-time curve was larger following PACAP38 (P = 0.004) and VIP (P = 0.01) compared to placebo. We found no statistical difference in pain perception between PACAP38 and VIP. Skin blood flow increase, flare and wheal were larger after both PACAP38 (P = 0.011) and VIP (P = 0.001) compared to placebo. VIP induced a considerably larger increase in skin blood flow, flare and wheal than PACAP38 (P = 0.002). In conclusion, we found that peripheral nociceptive cutaneous responses elicited by PACAP38 and VIP are similar in healthy volunteers. This suggests that acute pain and vasomotor responses following intradermal injections of PACAP38 and VIP are primarily mediated by VPAC receptors

Attenuation of muscle atrophy by an N-terminal peptide of the receptor for proteolysis-inducing factor (PIF)

Background: Atrophy of skeletal muscle in cancer cachexia has been attributed to a tumour-produced highly glycosylated peptide called proteolysis-inducing factor (PIF). The action of PIF is mediated through a high-affinity membrane receptor in muscle. This study investigates the ability of peptides derived from the 20 N-terminal amino acids of the receptor to neutralise PIF action both in vitro and in vivo. Methods: Proteolysis-inducing factor was purified from the MAC16 tumour using an initial pronase digestion, followed by binding on DEAE cellulose, and the pronase was inactivated by heating to 80°C, before purification of the PIF using affinity chromatography. In vitro studies were carried out using C2C12 murine myotubes, while in vivo studies employed mice bearing the cachexia-inducing MAC16 tumour. Results: The process resulted in almost a 23?000-fold purification of PIF, but with a recovery of only 0.004%. Both the D- and L-forms of the 20mer peptide attenuated PIF-induced protein degradation in vitro through the ubiquitin-proteosome proteolytic pathway and increased expression of myosin. In vivo studies showed that neither the D- nor the L-peptides significantly attenuated weight loss, although the D-peptide did show a tendency to increase lean body mass. Conclusion: These results suggest that the peptides may be too hydrophilic to be used as therapeutic agents, but confirm the importance of the receptor in the action of the PIF on muscle protein degradation

An Energy-Saving Development Initiative Increases Birth Rate and Childhood Malnutrition in Rural Ethiopia

BACKGROUND: Evolutionary life history theory predicts that, in the absence of contraception, any enhancement of maternal condition can increase human fertility. Energetic trade-offs are likely to be resolved in favour of maximizing reproductive success rather than health or longevity. Here we find support for the hypothesis that development initiatives designed to improve maternal and child welfare may also incur costs associated with increased family sizes if they do not include a family planning component. METHODS AND FINDINGS: Demographic and anthropometric data were collected in a rural Ethiopian community benefiting from a recent labour-saving development technology that reduces women's energetic expenditure ( n = 1,976 households). Using logistic hazards models and general linear modelling techniques, we found that whilst infant mortality has declined, the birth rate has increased, causing greater scarcity of resources within households. CONCLUSIONS: This study is, to our knowledge, the first to demonstrate a link between a technological development intervention and an increase in both birth rate and childhood malnutrition. Women's nutritional status was not improved by the energy-saving technology, because energy was diverted into higher birth rates. We argue that the contribution of biological processes to increased birth rates in areas of the developing world without access to modern contraception has been overlooked. This highlights the continued need for development programmes to be multisectoral, including access to and promotion of contraception

Triptans attenuate capsaicin-induced CREB phosphorylation within the trigeminal nucleus caudalis: a mechanism to prevent central sensitization?

The c-AMP-responsive element binding protein (CREB) and its phosphorylated product (P-CREB) are nuclear proteins expressed after stimulation of pain-producing areas of the spinal cord. There is evidence indicating that central sensitization within dorsal horn neurons is dependent on P-CREB transcriptional regulation. The objectives of the study were to investigate the expression of P-CREB in cells in rat trigeminal nucleus caudalis after noxious stimulation and to determine whether pre-treatment with specific anti-migraine agents modulate this expression. CREB and P-CREB labelling was investigated within the trigeminal caudalis by immunohistochemistry after capsaicin stimulation. Subsequently, the effect of i.v. pre-treatment with either sumatriptan (n = 5), or naratriptan (n = 7) on P-CREB expression was studied. Five animals pre-treated with i.v. normal saline were served as controls. CREB and P-CREB labelling was robust in all animal groups within Sp5C. Both naratriptan and sumatriptan decreased P-CREB expression (p = 0.0003 and 0.0013) within the Sp5C. Triptans attenuate activation of CREB within the central parts of the trigeminal system, thereby leading to potential inhibition of central sensitization. P-CREB may serve as a new marker for post-synaptic neuronal activation within Sp5C in animal models relevant to migraine

Arabidopsis thaliana encodes a bacterial-type heterodimeric isopropylmalate isomerase involved in both Leu biosynthesis and the Met chain elongation pathway of glucosinolate formation

The last steps of the Leu biosynthetic pathway and the Met chain elongation cycle for glucosinolate formation share identical reaction types suggesting a close evolutionary relationship of these pathways. Both pathways involve the condensation of acetyl-CoA and a 2-oxo acid, isomerization of the resulting 2-malate derivative to form a 3-malate derivative, the oxidation-decarboxylation of the 3-malate derivative to give an elongated 2-oxo acid, and transamination to generate the corresponding amino acid. We have now analyzed the genes encoding the isomerization reaction, the second step of this sequence, in Arabidopsis thaliana. One gene encodes the large subunit and three encode small subunits of this enzyme, referred to as isopropylmalate isomerase (IPMI) with respect to the Leu pathway. Metabolic profiling of large subunit mutants revealed accumulation of intermediates of both Leu biosynthesis and Met chain elongation, and an altered composition of aliphatic glucosinolates demonstrating the function of this gene in both pathways. In contrast, the small subunits appear to be specialized to either Leu biosynthesis or Met chain elongation. Green fluorescent protein tagging experiments confirms the import of one of the IPMI small subunits into the chloroplast, the localization of the Met chain elongation pathway in these organelles. These results suggest the presence of different heterodimeric IPMIs in Arabidopsis chloroplasts with distinct substrate specificities for Leu or glucosinolate metabolism determined by the nature of the different small subunit

Modern Clinical Research on LSD

All modern clinical studies using the classic hallucinogen lysergic acid diethylamide (LSD) in healthy subjects or patients in the last 25 years are reviewed herein. There were five recent studies in healthy participants and one in patients. In a controlled setting, LSD acutely induced bliss, audiovisual synesthesia, altered meaning of perceptions, derealization, depersonalization, and mystical experiences. These subjective effects of LSD were mediated by the 5-HT2A receptor. LSD increased feelings of closeness to others, openness, trust, and suggestibility. LSD impaired the recognition of sad and fearful faces, reduced left amygdala reactivity to fearful faces, and enhanced emotional empathy. LSD increased the emotional response to music and the meaning of music. LSD acutely produced deficits in sensorimotor gating, similar to observations in schizophrenia. LSD had weak autonomic stimulant effects and elevated plasma cortisol, prolactin, and oxytocin levels. Resting-state functional magnetic resonance studies showed that LSD acutely reduced the integrity of functional brain networks and increased connectivity between networks that normally are more dissociated. LSD increased functional thalamocortical connectivity and functional connectivity of the primary visual cortex with other brain areas. The latter effect was correlated with subjective hallucinations. LSD acutely induced global increases in brain entropy that were associated with greater trait openness 14 days later. In patients with anxiety associated with life-threatening disease, anxiety was reduced for 2 months after two doses of LSD. In medical settings, no complications of LSD administration were observed. These data should contribute to further investigations of the therapeutic potential of LSD in psychiatry

Hallucinogen-like actions of 2,5-dimethoxy-4-( n )-propylthiophenethylamine (2C-T-7) in mice and rats

Few studies have examined the effects of 2,5-dimethoxy-4-( n )-propylthiophenethylamine (2C-T-7) in vivo.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46369/1/213_2005_Article_9.pd