Characterization of liquefied product from cellulose with phenol in the presence of sulfuric acid

The average molecular weight, the amount of bound phenol of liquefied cellulose and the substitution pattern of bound phenol as well as newly formed residue in the late stage of liquefaction were examined in various liquefaction conditions. The linkage fashion of bound phenol was governed by the liquefaction condition. Phenol extended molecular weight by the reaction with decomposed fragments from cellulose and formed new residue when insufficient amount was charged. On the other hand, phenol played a role of an end-cap reagent when sufficient amount was charged. Bound phenol with o-substitution increased with increasing liquefaction temperature.     

S-allyl cysteine attenuated CCl4-induced oxidative stress and pulmonary fibrosis in rats

This study examined effects of S-allyl cysteine (SAC) on carbon tetrachloride (CCl4)-induced interstitial pulmonary fibrosis in Wistar rats. CCl4 (0.5 ml/kg) was intraperitoneally injected into rats twice a week for 8 weeks, and SAC (50, 100, or 200 mg/kg), N-acetyl cysteine (NAC, 200 or 600 mg/kg), or L-cysteine (CYS, 600 mg/kg) were orally administrated to rats everyday for 8 weeks. SAC significantly reduced the increases of transforming growth factor beta, lipid peroxides, AST, and ALT in plasma, induced by CCl4. Although CCl4 is mainly metabolized by hepatic cytochrome P450, CCl4 induced systemic inflammation and some organ fibrosis. SAC dose-dependently and significantly attenuated CCl4-induced systemic inflammation and fibrosis of lung. SAC also inhibited the decrease of thiol levels, the increase of inducible nitric oxide synthase expression, the infiltration of leukocytes, and the generation of reactive oxygen species in lungs. Although NAC and CYS attenuated CCl4-induced pulmonary inflammation and fibrosis, the order of preventive potency was SAC > NAC > CYS according to their applied doses. These results indicate that SAC is more effective than other cysteine compounds in reducing CCl4-induced lung injury, and might be useful in prevention of interstitial pulmonary fibrosis.     

Microtubule sliding movement in tilapia sperm flagella axoneme is regulated by Ca2+/calmodulin-dependent protein phosphorylation

Demembranated euryhaline tilapia Oreochromis mossambicus sperm were reactivated in the presence of concentrations in excess of 10(-6) M Ca(2+). Motility features changed when Ca(2+) concentrations were increased from 10(-6) to 10(-5) M. Although the beat frequency did not increase, the shear angle and wave amplitude of flagellar beating increased, suggesting that the sliding velocity of microtubules in the axoneme, which represents dynein activity, rises with an increase in Ca(2+). Thus, it is possible that Ca(2+) binds to flagellar proteins to activate flagellar motility as a result of the enhanced dynein activity. One Ca(2+)-binding protein (18 kDa, pI 4.0), calmodulin (CaM), was detected by (45)Ca overlay assay and immunologically. A CaM antagonist, W-7, suppressed the reactivation ratio and swimming speed, suggesting that the 18 kDa Ca(2+)-binding protein is CaM and that CaM regulates flagellar motility. CaMKIV was detected immunologically as a single 48 kDa band in both the fraction of low ion extract of the axoneme and the remnant of the axoneme, suggesting that CaMKIV binds to distinct positions in the axoneme. It is possible that CaMKIV phosphorylates the axonemal proteins in a Ca(2+)/CaM-dependent manner for regulating the dynein activity. A (32)P-uptake in the axoneme showed that 48, 75, 120, 200, 250, 380, and 400 kDa proteins were phosphorylated in a Ca(2+)/CaM kinase-dependent manner. Proteins (380 kDa) were phosphorylated in the presence of 10(-5) M Ca(2+). It is possible that an increase in Ca(2+) induces Ca(2+)/CaM kinase-dependent regulation, including protein phosphorylation for activation/regulation of dynein activity in flagellar axoneme.     

Involvement of disulfide bonds and histidine 172 in a unique beta-sheet to alpha-helix transition of alpha 1-acid glycoprotein at the biomembrane interface

Human alpha(1)-acid glycoprotein (AGP), which is comprised of 183 amino acid residues and 5 carbohydrate chains, is a major plasma protein that binds to basic and neutral drugs as well as to steroid hormones. It has a beta-sheet-rich structure in aqueous solution. Our previous findings suggest that AGP forms an alpha-helix structure through an interaction with biomembranes. We report herein on a study of the mechanism of alpha-helix formation in AGP using various modified AGPs. The disulfide reduced AGP (R-AGP) was extensively unfolded, whereas asialylated AGP (A-AGP) maintained the native structure. Intriguingly, reduced and asialylated AGP (RA-AGP) increased the alpha-helix content as observed in the presence of biomembrane models, and showed a significant decrease in ligand binding capacity. This suggests that AGP has an innate tendency to form an alpha-helix structure, and disulfide bonds are a key factor in the conformational transition between the beta-sheet and alpha-helix structures. However, RA-AGP with all histidine residues chemically modified (HRA-AGP) was found to lose the intrinsic ability to form an alpha-helix structure. Furthermore, disulfide reduction of the H172A mutant expressed in Pichia pastoris also caused a similar loss of folding ability. The present results indicate that disulfide bonds and the C-terminal region, including H172 of AGP, play important roles in alpha-helix formation in the interaction of the protein with biomembranes.     

Modification of Morphine-induced Hyperlocomotion and Antinociception in Mice by Clorgyline,a Monoamine Oxidase-A Inhibitor

We evaluated the effects of pretreatment with clorgyline, an irreversible monoamine oxidase (MAO)-A inhibitor, on morphine-induced hyperlocomotion and antinociception. A single administration of morphine (30 mg/kg, i.p.) to male ICR mice induced a hyperlocomotion. ANOVA analysis revealed the statistical significance of the morphine effect on horizontal locomotion and of the clorgyline pretreatment × morphine interaction effect, but not of the effect of clorgyline pretreatment. The initial (5 min after challenge) phase of morphine actions vs. saline challenge appeared as if morphine had a strong inhibitory effect on locomotor activity in combination with different doses of clorgyline. The mice administered with morphine in combination of clorgyline (1 and 10 mg/kg) did not show any stereotypic behaviors. Clorgyline at a dose of 0.1 mg/kg but not other doses tested significantly potentiated morphine-induced antinociception evaluated by tail flick but not hot plate test. During the measurements of locomotor activity and antinociception, clorgyline at doses of 1 and 10 mg/kg significantly inhibited monoamine metabolism through MAO. These results suggest that clorgyline showed an inhibitory effect on morphine-induced hyperlocomotion, but not antinociception, through MAO inhibition. There is not a possibility that clorgyline pretreatment enhanced morphine action on motor activity, resulting in the abnormal behavior from hyperlocomotion to stereotypic movements.     

Morphological aspects of apoptosis in heart diseases

It has been suggested that apoptosis may be responsible for a significant amount of cardiomyocyte death during acute myocardial infarction as well as for a progressive loss of surviving cells in failing hearts. Typical apoptosis can indeed be induced in cardiomyocytes at the experimental conditions. In actual heart diseases, in contrast, there is very little direct morphological evidence of apoptosis in cardiomyocytes occurring at any stage of myocardial infarction and heart failure, despite the availability of much indirect evidence that includes detection of DNA fragmentation and apoptosis-related factors. For that reason, the potential efficacy of therapeutic intervention to prevent apoptosis remains controversial. This review will survey available data from both animals and humans to critically assess the role of cardiomyocyte apoptosis during myocardial infarction and its relevance to myocardial remodeling and during progression to heart failure. Also considered will be nonmyocyte interstitial cells, which have received less attention than myocytes despite definitive evidence of their apoptosis in the infarcted heart and recent studies suggesting that blockade of apoptosis among these cells mitigates postinfarction cardiac remodeling and heart failure. We conclude from our survey that there are many hurdles to surmount before regulation of apoptosis can be clinically applied in the treatment of myocardial infarction and heart failure.     

Effects of frozen conditions on stereoselectivity and velocity of O-glycosylation reactions

Rate acceleration of O-glycosylation had been observed in p-xylene under frozen conditions, when thioglycosides were activated by methyl trifluoromethane sulfonate. Curiously, significant perturbation of stereoselectivity was observed. Effects of various factors, such as solvent, concentration, anomeric configuration and protective groups of the donor, were systematically examined to clarify the mechanistic implications of stereoselectivity on glycosylation under frozen system. Our study revealed that the stereoselectivity was affected by concentration both in liquid as well as in frozen conditions, indicating that rate acceleration effect in frozen solvent was caused by highly concentrated environments.     

Process of reductive evolution during 10 years in plasmids of a non-insect-transmissible phytoplasma

A non-insect-transmissible phytoplasma strain (OY-NIM) was obtained from insect-transmissible strain OY-M by plant grafting using no insect vectors. In this study, we analyzed for the gene structure of plasmids during its maintenance in plant tissue culture for 10 years. OY-M strain has one plasmid encoding orf3 gene which is thought to be involved in insect transmissibility. The gradual loss of OY-NIM plasmid sequence was observed in subsequent steps: first, the promoter region of orf3 was lost, followed by the loss of then a large region including orf3, and finally the entire plasmid was disappeared. In contrast, no mutation was found in a pseudogene on OY-NIM chromosome in the same period, indicating that OY-NIM plasmid evolved more rapidly than the chromosome-encoded gene tested. Results revealed an actual evolutionary process of OY plasmid, and provide a model for the stepwise process in reductive evolution of plasmids by environmental adaptation. Furthermore, this study indicates the great plasticity of plasmids throughout the evolution of phytoplasma.