Background-A novel immunomodulator, KRP-203, the molecular structure of which has some similarity to FTY720, has been developed for use in organ transplantation. The present study was designed to investigate the potency and safety of KRP-203 on allograft survival against both acute and chronic rejection in rat skin and heart transplantation. Methods and Results-KRP-203 significantly prolonged skin or heart allograft survival of a minor histocompatibility complex (mHC)-disparate (LEW to F344) rat combination. Histopathological and immunohistochemical analysis at 100 days after mHC-disparate rat heart transplantation revealed that KRP-203 treatment significantly inhibited infiltration of inflammatory cells, including macrophages and T cells; expression of endothelin-1 and transforming growth factor- 1 ; and IgG deposition and eventually attenuated neointimal formation and myocardial fibrosis. KRP-203 also prolonged heart allograft survival in a major histocompatibility complex (MHC)-incompatible (DA to LEW) rat combination, but the efficacy was not as significant. However, KRP-203 combined with a subtherapeutic dose of cyclosporin A synergistically prolonged the heart allograft survival. Flow cytometric analysis demonstrated that KRP-203 reduced the number of peripheral blood mononuclear cells (lymphocytes and monocytes) but not granulocytes and enhanced lymphocyte homing into peripheral lymph nodes. The influence of KRP-203 on heart rate changes in Hartley guinea pigs was examined. KRP-203 had less of a tendency to cause bradycardia than FTY720. Conclusions-These findings demonstrated that KRP-203 prolonged skin and heart allograft survival and significantly attenuated chronic rejection and bradycardia as an adverse effect. Therefore, KRP-203 offers considerable potential as a novel therapeutic immunosuppressant in patients with organ transplantation. (Circulation. 2005;111:222-229.)
Summary
Replication of the Escherichia coli chromosome is initiated synchronously
from all origins (oriC) present in a cell at a fixed time in the cell cycle
under given steady state culture conditions. A mechanism to ensure the cyclic initiation
events operates through the chromosomal site, datA, which titrates exceptionally
large amounts of the bacterial initiator protein, DnaA, to prevent overinitiation.
Deletion of the datA locus results in extra initiations and altered temporal
control of replication. There are many other sites on the E. coli chromosome
that can bind DnaA protein, but the contribution of these sites to the control of
replication initiation has not been investigated. In the present study, seven major
DnaA binding sites other than datA have been examined for their influence
on the timing of replication initiation. Disruption of these seven major binding
sites, either individually or together, had no effect on the timing of initiation
of replication. Thus, datA seems to be a unique site that adjusts the balance
between free and bound DnaA to ensure that there is only a single initiation event
in each bacterial cell cycle. Mutation either in the second or the third DnaA box
(a 9 basepair DnaA‐binding sequence) in datA was enough to induce asynchronous
and extra initiations of replication to a similar extent as that observed with the
datA‐deleted strain. These DnaA boxes may act as cores for the cooperative
binding of DnaA to the entire datA region.
The in vivo metabolism of 4-bromo-2,5-dimethoxyphenethylamine (2C-B), a ring-substituted psychoactive phenethylamine, in the rat was studied. Male Wistar rats were administered 10 mg/kg of 2C-B hydrochloride orally, and 24 h urine fractions were collected. After enzymatic hydrolysis of the urine samples, the metabolites were extracted by liquid-liquid extraction and analyzed by gas chromatography-mass spectrometry. 2-(4-Bromo-2,5-dimethoxyphenyl)-ethanol, 4-bromo-2,5-dimethoxyphenylacetic acid, 2-(2-hydroxy-4-bromo-5-methoxyphenyl)-ethylamine, 2-(2-methoxy-4-bromo-5-hydroxyphenyl)-ethylamine, 1-acetoamino-2-(2-hydroxy-4-bromo-5-methoxyphenyl)-ethane, and 1-acetoamino-2-(2-methoxy-4-bromo-5-hydroxyphenyl)-ethane were identified as 2C-B metabolites. These findings suggest that at least two metabolic pathways for 2C-B are operative in rats. The first pathway leads to the corresponding aldehyde metabolite by deamination, which is subsequently reduced or oxidized, to give the corresponding alcohol and carboxylic acid metabolites. The second pathway leads to the corresponding 2-O-desmethyl or 5-O-desmethyl metabolites in which the amino group is subsequently acetylated.
Reversed-polarity (RP) capillary electrophoresis/positive ion electrospray ionization mass spectrometry (CE-ESI+ MS) and tandem mass spectrometry (MS/MS) were utilized for simultaneous chiral separation of nine amphetamine-type stimulants (ATS) (dl-norephedrine, dl-norpseudoephedrine, dl-ephedrine, dl-pseudoephedrine, dl-amphetamine, dl-methamphetamine, dl-methylenedioxyamphetamine, dl-methylenedioxymethamphetamine, and dl-methylenedioxyethylamphetamine). Using highly sulfated gamma-cyclodextrin (SU(XIII)-gamma-CD) as a chiral selector, the nine ATS were completely separated within 50 min. The migrated ATS-CD complex was dissociated at the ESI interface, and only ATS molecules went into the MS detector so that all 18 individual enantiomers were identified by their mass spectra. The detection limit of MS/MS was 10 times more sensitive than those for single MS. Seized d-methamphetamine hydrochloride samples dissolved at high concentration (20 mg/mL) were analyzed. Impurities originating in the precursor such as l-ephedrine and d-pseudoephedrine were detected and identified by tandem mass spectra.
The fluorescence spectra of 5-hydroxytryptamine (serotonin) in acidic media have been studied by means of fluorescence polarization, temperature dependence of fluorescence, and kinetics of the protonation in H2O and D2O. The red-shifted emission appearing by protonation in the excited state is ascribed to the protonated form of serotonin at C4. In order to confirm the assignment of electronic spectra, the absorption spectra of the single crystal of 5-methoxyindole-3-acetic acid have been measured by means of reflection technique, the directions of transition moments being determined by polarization analysis. Calculation was carried out on the energy levels of the excited state for serotonin and its protonated forms, and the directions of transition moments were compared with the experimental results.
Capillary electrophoresis was developed for the analysis of low explosive residue, because a significant amount of inorganic anions and cations remain after deflagration. Certain high explosives, such as emulsion explosives, produce a vast quantity of inorganic ions after a blast and can readily be analyzed using capillary electrophoresis. Often, trace amounts of explosive residues may be present on physical evidence submitted in criminal cases. Trace amounts of inorganic ions such as nitrate, chlorate, and ammonium may be detected using capillary electrophoresis owing to the low detection limit of these species. The utility of capillary electrophoresis in the analysis of explosive residues is in its ability to simultaneously analyze trace explosives and ionic products present on physical evidence.
We investigated the simultaneous chiral separation of nine amphetamine type stimulants (dl-norephedrine, dl-norpseudoephedrine, dl-ephedrine, dl-pseudoephedrine, dl-amphetamine, dl-methamphetamine, dl-methylenedioxyamphetamine (MDA), dl-methylenedioxymethamphetamine (MDMA), and dl-methylenedioxyethylamphetamine (MDEA)) by capillary electrophoresis using highly sulfated gamma-cyclodextrin (SU(XIII)-gamma-CD) as a chiral selector. Three different approaches using SU(XIII)-gamma-CD with 50 mM phosphate background electrolyte were designed; (I) high CD concentration (10 mM SU(XIII)-gamma-CD) at neutral pH (pH 7.0) in the normal polarity mode, (II) low CD concentration (1.0 mM) at low pH (pH 2.6) in the normal polarity mode and (III) high CD concentration at low pH (pH 2.6) in the reversed-polarity mode. In mode (II), the effects of adding three neutral CDs (beta-CD, dimethyl-beta-CD and hydroxypropyl-beta-CD) were also investigated. The best separation was obtained after optimizing mode (III) as follows: run buffer of 10 mM SU(XIII)-gamma-CD with 50 mM phosphate background electrolyte at pH 2.6, applied voltage of -12 kV and capillary temperature of 15 degrees C.
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