Morphine addiction and withdrawal alters brain peptide concentrations

This study demonstrates that, during morphine addiction and withdrawal in rats profound alterations in the concentrations of a variety of brain peptides occur. Somatostatin, cholecystokinin, neurotensin and substance P concentrations increased during morphine addiction. Naloxone-induced withdrawal decreased brain concentrations of TRH, somatostatin, neurotensin and substance P. Naloxone alone decreased thalamic substance P and neurotensin concentrations. Vasoactive intestinal peptide concentrations were unaltered by any of the treatments. The fall in the tissue concentration of somatostatin during naloxone-induced withdrawal correlated well with the fall in the circulating growth hormone, suggesting that this could be secondary to somatostatin release. Our data support the hypothesis that brain peptides, acting locally in the brain as neuromodulators, play an important role in the genesis of the syndromes of morphine addiction and withdrawal.     

Synthèse des l-fucose et l-(3-2H)fucose à partir du d-mannose

Oxidation with the dimethyl sulfoxide-acetic anhydride reagent of methyl 2-O-acetyl-4,6-O-benzylidene-α-d-mannopyranoside, obtained in quantitative yield from the corresponding 4,6-benzylidene acetal by stereoselective opening of a 2,3-orthoester, led in good yield to methyl 2-O-acetyl-4,6-O-benzylidene-α-d-arabino-hexopyranosid-3-ulose, which was reduced with either sodium borohydride or sodium borodeuteride into a methyl 4,6-O-benzylidene-α-d-altropyranoside or its 3-²H derivative. A sequence involving a C-6 halogenation-dehydrohalogenation followed by catalytic hydrogenation of the resulting methyl 6-deoxy-α-d-arabino-hex-5-enopyranoside gave methyl 6-deoxy-β-l-galactopyranoside (methyl β-l-fucopyranoside) and then α-l-fucose, with an overall yield of 24% with respect to the starting methyl α-d-mannopyranoside.     

Hydroxyamino acid utilization and alpha-ketobutyrate toxicity in Pseudomonas cepacia

Growth of Pseudomonas cepacia 249 on D-threonine required a mutation to permit D-hydroxyamino acid deaminase formation and L-valine to overcome alpha-ketobutyrate toxicity. Strain 249 lacked a second D-hydroxyamino acid deaminase formed by other strains.     

The biology ofSclerotinia sclerotiorum,S. trifoliorum,andS. minor with emphasis on specific nomenclature

The separation ofSclerotinia sclerotiorum (Lib.) de Bary, 5.trifoliorum Erikss., andS. minor Jagger into three distinct species has been based on traditional morphological and physiological criteria such as gross cultural characteristics, sclerotial size, ascus and ascospore dimensions, time of apothecial development in the field, and host association. However, these characteristics tend to be variable and some workers have concluded that the three fungi should be included in one species, 5.sclerotiorum. Recently, new data have been published on morphological, cultural, physiological, ontogenetic, enzyme pattern, mycelial interaction, and cytological characteristics of isolates ofSclerotinia spp. This information supplements, but does not replace, that available from more traditional taxonomic methods and helps to resolve the controversy on the taxonomy and nomenclature of these fungi. This article reviews the relevant literature on the biology of 5.sclerotiorum, S. trifoliorum, and 5.minor, with particular emphasis given to those differences between them that could be of significance regarding their specific nomenclature. After an introduction, mycelia, microconidia, sclerotia, apothecia, infection, control, and taxonomy and nomenclature are discussed. The authors conclude thatS. sclerotiorum, S. trifoliorum, andS. minor are distinct species. The characteristics used to distinguish between them are summarized in table form.     

Hepatic metabolism of prostacyclin (PGI2) in the rabbit: Formation of a potent novel inhibitor of platelet aggregation

Metabolism of [9-³H]-PGI₂ was studied in the isolated Tyrode's perfused rabbit liver. Five products, four radioactive and one non-radioactive, were identified in the perfusate: 19-hydroxy-6-keto-PGF_1α, 6-keto-PGF_1α, dinor-6-keto-PGF_1α, pentanor PGF_1α and a 6-keto-PGE₁-like substance. The first two, 19-hydroxy-6-keto-PGF_1α and 6-keto-PGF_1α, represented 5% and 45% respectively, of the total radioactivity; the last two accounted for 39%. The presence of dinor and pentanor derivatives of 6-keto-PGF_1α indicated that β -oxidation and oxidative-decarboxylation occurs in the liver as the major metabolic pathway of PGI₂. One non-radioactive metabolite which co-migrated with authentic 6-keto-PGE₁ was found to inhibit platelet aggregation, having a potency similar to authentic 6-keto-PGE₁, and its effect can be eliminated by boiling and by alkali treatment. This metabolite, having similar Rf value on TLC and biological behavior as 6-keto-PGE₁, may arise from oxidation of 6-keto-PGF_1α via the 9-hydroxyprostaglandin dehydrogenase pathway, as suggested by recovery of tritiated water in the aqueous phase of the perfusate. This material, a potent inhibitor of platelet aggregation, may arise from PGI₂ or its hydrolysis product, 6-keto-PGF_1α.     

Enzymatic inactivation of human alpha-1-proteinase inhibitor by neutrophil myeloperoxidase.

Peanut agglutinin was acylated with a new heterobifunctional, cleavable photosensitive crosslinking reagent, N-[4-(p-azidophenylazo)benzoyl]-3-aminopropyl-N′-oxysuccinimide ester. The lectin derivative binds specifically and reversibly to neuraminidase-treated human erythrocyte ghosts and upon irradiation covalent attachment of over 35% of the bound lectin occurs. The affinity-crosslinked ghosts were solublized in deoxycholate, immunoprecipitated with anti-peanut agglutinin antiserum, and analyzed by sodium dodecylsulfate polyacrylamine gel electrophoresis. Bands containing both peanut agglutinin and membrane glycoproteins were detected with apparent molecular weights of 58 000, 85 000, 110 000 and 135 000. Upon subsequent cleavage with sodium dithionite, asialoglycophorin A (apparent M.W. 41 000 and 85 000) and a second glycoprotein (apparent M.W. 58 000 – 61 000) were tentatively identified as the receptors for peanut agglutinin in the intact membrane.     

Patterns of early and late discharges in somatotopically identified precentral neurons in awake monkeys in response to somatic inputs.

Extracellular recordings were made of single neurons in precentral cortex of awake monkeys. These neurons were somatotopically identified with respect to their responses to inputs from single joints or their somatic surround. Many of these neurons exhibited early (less than 50 ms) and late (greater than 50 ms) discharges in response to flexion or extension torques delivered about the wrist. With the monkey in a mode requiring opposition to the injected torque, all responsive neurons showed a parallel excitatory or inhibitory modification in the early and late discharges. This was true both for cells identified as wrist (flexion-extension) neurons and those identified as nonwrist (flexion-extension) neurons. These findings indicate that the reflex and voluntary components of percentral discharge invariably show a congruent functional response to a torque disturbance, for this particular instruction set.     

Hydroxy amino acid metabolism in Pseudomonas cepacia: role of L-serine deaminase in dissimilation of serine, glycine, and threonine.

Growth of Pseudomonas cepacia (P. multivorans) on serine depended upon induction of a previously undescribed L-serine deaminase distinct from threonine deaminase. Formation of the enzyme was induced during growth on serine, glycine, or threonine. The induction pattern reflected a role of the enzyme in catabolism of these three amino acids. Both threonine and glycine supported growth of serine auxotrophs and were presumably converted to serine and pyruvate in the course of their degradation. Mutant strains deficient in serine deaminase, or unable to use pyruvate as a carbon source, failed to utilize serine or glycine and grew poorly with threonine, whereas strains deficient in threonine dehydrogenase or alpha-amino beta-ketobutyrate:coenzyme A ligase (which together convert threonine to glycine and acetyl coenzyme A) failed to utilize threonine or derepress serine deaminase in the presence of this amino acid. The results confirm for the first time the role of alpha-amin beta-ketobutyrate:coenzyme A ligase in threonine degradation and indicate that threonine does not mimic serine as an inducer of serine deaminase.