Safety evaluation of the use of calcineurin inhibitor to prenatal and postpartum women in Japan from a health administrative database

BACKGROUND

To investigate the use of calcineurin inhibitors (CNIs) in pregnant Japanese women and to evaluate their safety in infants.

METHODS

Data were extracted from the claims database of the Japan Medical Data Center. The prevalence of CNIs was evaluated 180 days before pregnancy onset, during pregnancy, and within180-days post partum. We investigated the characteristics of the infants, including the presence of major malformations and their diagnoses, for 1 year after birth.

RESULTS

A total of 91,865 pregnancies in 80,049 women were included. Fifty-three women were prescribed CNIs between 180-day before pregnancy onset and 180-day postpartum; 35 of the 53 women were prescribed the drugs during pregnancy, and 10 of their infants were born preterm. Three were diagnosed with major congenital malformations, such as patent ductus arteriosus. Six preterm infants presented with infant respiratory distress syndrome.

CONCLUSIONS

No congenital anomalies were clearly attributable to the use of CNIs during pregnancy.

Functional characterization of 21 CYP2C19 allelic variants for clopidogrel 2-oxidation

Genetic variations in cytochrome P450 2C19 (CYP2C19) contribute to interindividual variability in the metabolism of therapeutic agents such as clopidogrel. Polymorphisms in CYP2C19 are associated with large interindividual variations in the therapeutic efficacy of clopidogrel. This study evaluated the in vitro oxidation of clopidogrel by 21 CYP2C19 variants harboring amino acid substitutions. These CYP2C19 variants were heterologously expressed in COS-7 cells, and the kinetic parameters of clopidogrel 2-oxidation were estimated. Among the 21 CYP2C19 variants, 12 (that is, CYP2C19.5A, CYP2C19.5B, CYP2C19.6, CYP2C19.8, CYP2C19.9, CYP2C19.10, CYP2C19.14, CYP2C19.16, CYP2C19.19, CYP2C19.22, CYP2C19.24 and CYP2C19.25) showed no or markedly low activity compared with the wild-type protein CYP2C19.1B. This comprehensive in vitro assessment provided insights into the specific metabolic activities of CYP2C19 proteins encoded by variant alleles, and this may to be valuable when interpreting the results of in vivo studies.

OmpA is an adhesion factor of Aeromonas veronii, an optimistic pathogen that habituates in carp intestinal tract

AIMS

In the present study, we focused on one of the Aeromonas veronii isolates that exhibited marked adhesion onto carp intestine and studied its membrane-associated proteins for their possible involvement in mucosal adhesion.

METHODS AND RESULTS

We isolated a strain of Aer. veronii (CWP11) that exhibited a high degree of temperature-dependent adhesion activity onto carp intestinal tract and studied its adhesion factor. A proteomic analysis of the membrane-associated fraction showed the presence of multiple proteins that were specifically expressed in CWP11 cells cultured at 25 degrees C. Of these, a 30 kDa protein was identified to be OmpA by a mass fingerprint analysis. Cloning and nucleotide sequencing of the ompA region of CWP11 revealed the presence of two tandem ompA homologues (ompAI-ompAII). Escherichia coli that expressed either OmpAI or OmpAII exhibited marked adhesion onto carp intestinal surface. Disruption of ompAI by a homologous recombination technique resulted in marked reduction of the adhesion activity in CWP11.

CONCLUSION

The OmpA homologue plays an important role in the adhesion of the Aer. veronii strain onto the surface of intestinal tract.

SIGNIFICANCE AND IMPACT OF THE STUDY

We successfully identified an OmpA homologue to be an adhesion factor of Aer. veronii, an optimistic pathogen that habituates in carp intestinal tract.

Phylogenetic analysis of intestinal bacteria and their adhesive capability in relation to the intestinal mucus of carp

AIMS

The aims of the present study are to characterize the intestinal microbial community displaying a high-adhesive capability in fish, and to evaluate the relationship between mucosal adhesion of intestinal bacteria and fish health and disease.

METHODS AND RESULTS

A total of 707 aerobic bacteria isolated from carp intestine that were maintained under either feeding (feeding group) or no-feeding (no-feeding group) conditions and were performed adhesive assay. Isolates were divided into three categories on the basis of adhesive capability: high-, medium-, and low- adhesive capabilities. The average proportions of isolates with high-adhesive capability in the feeding and no-feeding groups were 30% and 32%, respectively. A phylogenetic analysis using a partial 16S rRNA gene demonstrated that most isolates with high-adhesive capability in both groups were classified as belonging to an Aeromonas group, and populations of isolates within high- and low-adhesive categories were markedly different.

CONCLUSIONS

Intestinal bacteria with a high-adhesive capability in relation to intestinal mucous always colonize on the surface of intestinal mucosa and grow in the intestinal tract of feeding carp. The adhesive capability of intestinal bacteria is essential for colonization and growth in the intestinal tract of fish.

SIGNIFICANCE AND IMPACT OF THE STUDY

Our results indicate that members of the Aeromonas group with adhesive capability always colonize on the surface of intestinal mucosa.

Molecular lego for the assembly of biosensing layers

We propose a procedure to assemble monolayers of redox mediator, coenzyme, enzyme and stabilizing polyelectrolyte on an electrode surface using essentially electrostatic and complexing interactions. In a first step a monolayer of redox mediator, substituted nitrofluorenones, is adsorbed. In a second step, a layer of calcium cations is immobilized at the interface. It establishes a bridge between the redox mediator and the subsequently adsorbed coenzyme NAD(+). In the next step we use the intrinsic affinity of the NAD(+) monolayer for dehydrogenases to build up a multilayer composed of mediator/Ca(2+)/NAD(+)/dehydrogenase. The so obtained modified electrode can be used as a biosensor. Quartz crystal microbalance measurements allowed us to better understand the different parameters responsible for the adsorption. A more detailed investigation of the system made it possible to finally stabilize the assembly sufficiently by the adsorption of a polyelectrolyte layer in order to perform rotating disk electrode measurements with the whole supramolecular architecture on the electrode surface.

Mediator-modified electrodes for catalytic NADH oxidation: high rate constants at interesting overpotentials

Carbon paste electrodes were modified with a nitrofluorenone derivative, 2,4,7-trinitro-9-fluorenone, adsorbed on zirconium phosphate (ZP). After electrochemical reduction of the fluorenone derivative, it turns into a very efficient mediator for electrocatalytic NADH oxidation, with a formal potential of about +250 mV vs. Ag/AgCl. The electrochemistry and the electrocatalytic properties of the mediator were investigated with cyclic voltammetry and rotating disk electrode methodology. The second order rate constant with NADH was evaluated and found to be higher than 10(6) M(-1) s(-1), thus approaching true diffusion controlled currents for NADH oxidation.

Affinity assembled multilayers for new dehydrogenase biosensors

We propose a novel approach, which allows the control of the spatial arrangement of redox mediator, coenzyme and enzyme on the electrode at a molecular level, using essentially electrostatic interactions. The first step consists of adsorbing a monolayer of molecules out of a new family of redox mediators, substituted nitrofluorenones. In a second step, a monolayer of calcium cations is immobilized at the interface. It serves as a bridge between the redox mediator and the subsequently adsorbed coenzyme. The weak interaction between a carboxyl group of the redox mediator and the coenzyme's phosphate groups, revealed by QCM measurements, allows the coenzyme to keep its natural activity in the adsorbed state. In the last step, we use the intrinsic affinity of this monolayer of NAD(+) for dehydrogenases to build up a supramolecular sandwich composed of mediator/Ca(2+)/NAD(+)/dehydrogenase. This simple modification procedure, which might constitute a versatile approach for the low cost assembly of well-defined biosensors surfaces, has been successfully applied to the enzymatic detection of glucose, glutamate and alcohol.

Electrodes modified with nitrofluorenone derivatives as a basis for new biosensors

We report about the electrocatalytic properties of electrodes modified by adsorption of nitro-fluorenone derivatives. The stable, adherent monolayer of these catalyst precursors can be transformed electrochemically into the corresponding hydroxylamine compounds (R-NO(2)+4e+4H(+)-->R-NHOH+H(2)O). The completely reversible two electron oxidation of the hydroxylamine leads to the nitroso compounds (R-NHOH-->R-NO+2e+2H(+)) that exhibit high catalytic activity in the electrooxidation of NADH at low overpotentials (-30 mV vs. Ag/AgCl) and therefore constitute a new family of efficient redox mediators for biosensor applications. A significant increase in catalytic activity (up to 500%) is observed after addition of calcium ions to the electrolyte. This is explained by a specific and bridging complexation between the coenzyme's phosphate groups and a carboxyl group present in the catalyst molecule. The interaction favours the contact between NADH and the surface confined catalyst, leading to a higher electron transfer efficiency. This interaction can be used in an approach of molecular level design for controlled monolayer deposition of catalyst, Ca(2+), NAD+ and enzyme. A very simple and inexpensive modification scheme, essentially based on electrostatic attraction, leads to electrodes that can be employed as reagentless biosensors for the electrochemical detection of common and commercially interesting analytes like glucose.

Simultaneous detection of cholyl adenylate and coenzyme A thioester utilizing liquid chromatography/electrospray ionization mass spectrometry

It has been proposed that acyl adenylate is first formed during activation of the carboxy group into the acyl CoA thioester, an intermediate in the formation of amino acid conjugates. Acyl CoA synthetases may be responsible for this acyl adenylate formation. Recently, we hypothesized the preferential formation of cholic acid adenylate, a major bile acid, preceding production of the corresponding CoA thioester in incubations with rat liver microsomal fractions. To verify this biosynthetic mechanism, monitoring of the incubation mixture of acyl adenylate together with both substrate and acyl CoA thioester is needed. We have developed a detection method for the simultaneous detection of these cholic acid derivatives utilizing liquid chromatography/electrospray ionization mass spectrometry. The CoA thioester of cholic acid forms a chelation complex with the divalent cations remaining on the silica gel packed into the analytical column. Both the addition of a chelating agent, such as EDTA, to the mobile phase and an adjustment of the mobile phase pH to a weak alkaline effectively removed such chelate formation, producing a sharp CoA thioester peak. For a simultaneous mass spectrometric analysis of cholic acid, the corresponding adenylate and CoA thioester, the combined use of a 300 A particle diameter ODS column and 20 mM ammonium acetate buffer (pH 9.0)/2-propanol/acetonitrile as the mobile phase have been proved to be preferable. To avoid any degradation of the chemically unstable adenylate produced in the incubation, we employed a direct injection of the sample onto a preconcentration column. The obtained results indicated a high sensitivity of this method.

The enantioselective immunoaffinity extraction of an optically active ibuprofen-modified peptide fragment

Acyl glucuronides are known to produce the covalently bound protein adducts which may be the cause of hypersensitivity and toxic responses to acidic drugs. The structural analysis of the drug-protein adducts is therefore needed. From this point of view, we developed an enantioselective immunoaffinity extraction method, which employs an immobilized antibody to specifically isolate peptide fragments that have been modified with optically active ibuprofen. Rabbits were immunized with (S)-ibuprofen coupled to bovine serum albumin through a beta-alanine group. The elicited antibody strongly recognizes the asymmetric center and the isobutylphenyl moiety of (S)-ibuprofen and its conjugates but has a low affinity for their anti podes. A 0.5-mL aliquot of the immunosorbent (11.5 mg of IgG/mL gel) prepared by immobilization of the antibody was capable of retaining up to 1 microg of (S)-ibuprofen. When a mixture of substance P with (R)- and (S)-ibuprofen-modified substance P was loaded on the immunosorbent, the (S)-ibuprofen-modified substance P was selectively retained. The modified peptide was quantitatively recovered by elution with 10 mM ammonium acetate buffer (pH 5.0)/methanol (5:95, v/v). The proposed method would be useful for the structural characterization of optically active ibuprofen-modified human serum albumin.

Direct injection method for quantitation of endogenous leukotriene E4 in human urine by liquid chromatography/electrospray ionization tandem mass spectrometry with a column-switching technique

A new analytical method employing liquid chromatography/tandem mass spectrometry (LC/MS/MS) with a column-switching system was developed for quantitative determination of leukotriene E4 (LTE4) in human urine. A column-switching system using a trapping column, which concentrates the analyte and removes salts and other water-soluble contaminants, allowed direct injection of human urine. Because simultaneously eluted endogenous contaminants suppressed the ionization efficiency of LTE4, good liquid chromatographic separation was very important for establishing this method, notwithstanding the high selectivity of MS/MS. The calibration curve was linear over the range from 10 to 3000 pg/mL, and the method showed good accuracy and precision. This method should therefore be very useful for determination of LTE4 amounts in human urine in studies on leukotriene metabolism and the efficacy of antileukotriene drugs.

Sequelae after limb-sparing surgery with major vascular resection for tumor of the lower extremity

PURPOSE

Limb-sparing procedures have recently replaced amputations as the treatment for tumors invading major vessels of the lower extremity. Major arteries must be reconstructed for limb salvage. The veins are not usually reconstructed. This study was undertaken to investigate the sequelae such as chronic venous disease after venous resection for tumors.

METHODS

Ten patients who underwent limb-sparing surgery for a tumor of the lower extremity or retroperitoneum that required major vascular resection were studied. The median follow-up period was 48 months. After combined resection of a major artery and vein, arterial reconstruction was performed. The veins were not reconstructed. The resected veins included the inferior vena cava (n = 2), the external iliac and common femoral veins (n = 3), the superficial femoral vein (n = 3), and the popliteal vein (n = 2). The main outcome measures were clinical classification of chronic venous disease in 10 patients and air plethysmography in seven patients.

RESULTS

Clinical classification was C(0A) in 6 patients, C(3A) in 1 patient, C(3S) in 2 patients, and C(4S) in 1 patient. Venous claudication with uncontrollable edema was observed in two patients with C(3S) disease. Pain and itching with inflammatory skin changes were observed in one patient with C(4S) disease. These three patients had undergone resection of the femoral vein, including the deep femoral vein along with proximal adductor muscles. Air plethysmography revealed that the ejection fraction was significantly lower and the residual volume fraction was significantly higher in the three patients with symptoms than in symptom-free patients.

CONCLUSIONS

Significant chronic venous disease was observed in the patients who underwent combined resection of the femoral vein, the deep femoral vein, and the adductor muscles for a tumor.

Bile acid acyl adenylate: a possible intermediate to produce a protein-bound bile acid

The non-enzymatic production of a protein-bound adduct by the action of the acyl adenylate of bile acids is described. On incubation of deoxycholyl adenylate with substance P in phosphate buffer, peptides covalently bound with one or two molecules of the bile acid were detected. The modified peptides were structurally characterized by time-of-flight mass spectrometry with matrix-assisted laser desorption/ionization (MALDI-TOFMS) in the post-source decay mode, and by liquid chromatography/electrospray ionization MS/MS. The deoxycholic acid was bound on substance P through the amino group at Arg-1 and/or Lys-3. The adenylate of cholic acid also produced the protein-bound bile acid on incubation with lysozyme, and the binding sites of the cholic acid appeared to be the lysine residues at 1, 33, 97 and 116. The results clearly suggest that bile acid adenylates in vivo may act as active intermediates to produce covalently bound bile acid adducts with peptides and proteins by nucleophilic displacement of the 5'-adenylic acid through the free amino groups.

Characterization of Japanese eel immunoglobulin M and its level in serum

Japanese eel immunoglobulin M (IgM) was purified from the sera of Anguilla japonica immunized with Edwardsiella tarda FPU 347 and characterized. Analysis of the purified IgM on sodium dodecyl sulfate-polyacrylamide gels (SDS-PAGE) under reducing and non-reducing conditions revealed that the eel IgM was a tetrameric protein with a molecular weight of 790,000; it contained an equimolar heavy chain and light chain with molecular weights of 72,000 and 25,000, respectively. While the N-terminal sequence of the heavy chain, VELTQPGSMVLKPGQSLTI, showed similarity to the variable regions of those of teleost fishes Igs, the N-terminal sequence of the light chain, DIVLTQSPAVQSVQLGDT, was similar to the variable regions of chondrostei and mammalian kappa chains. Lectin-binding assays showed that the binding of concanavalin A (Con A) to the Japanese eel IgM heavy chain was competitively inhibited by D-mannose and could be abolished by alpha-mannosidase treatment indicating the presence on the heavy chain of oligosaccharides, whose terminal were a bound mannoses. The average IgM concentration in the sera of the healthy eels was 3.4 mg ml(-1); it amounted to 10.3% of the total serum protein.

Infection with Edwardsiella tarda causes hypertrophy of liver cells in the Japanese flounder Paralichthys olivaceus

To study the direct cause of liver enlargement in the Japanese flounder Paralichthys olivaceus infected with Edwardsiella tarda, the fish were challenged with E. tarda and reared without feeding. The liver of fish exposed to the bacteria was markedly enlarged compared to that of the controls while no severe histopathological change appeared in the organ during the experiments. No notable difference was observed in the crude fat, glycogen, and water content of the liver between challenged and control fish. The size of liver cells and nuclei of the challenged fish was apparently larger than that of the controls. Analysis of crude DNA in the liver suggested that the number of liver cells of starved control fish significantly decreased during the experiment while that of the challenged fish was maintained at a level of the initial control. RNA/DNA ratio of the liver of challenged fish clearly increased while it decreased in the control fish during the experiment. These observations suggest that liver enlargement of flounder infected with E. tarda, at least in the early stage of infection, is not a result of any readily observable histopathological changes and that E. tarda infection causes hypertrophy of the cells, as well as preventing decrease in liver cell number.

Substrate specificity of THCA-CoA oxidases from rat liver light mitochondrial fractions on dehydrogenation of 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-cholestanoic acid CoA thioester

The substrate specificity of rat liver peroxisomal 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-cholestanoyl-CoA (THCA-CoA) oxidases, which catalyze the dehydrogenation of 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-cholestanoic acid (THCA) CoA thioester, having an asymmetric center at C-25, to form (24E)-3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-cholest-24-enoic acid (delta 24-THCA) CoA thioester, was studied. The stable isotope labeled substrates, [3,7,12-18O3]-(25R)- and (25S)-THCA CoA thioesters were synthesized by an exchange reaction of carbonyl oxygens on a steroid nucleus of 3,7,12-trioxo-5 beta-cholestanoic acid, followed by metal hydride reduction and condensation reaction with CoA. After incubation of a mixture of unlabeled (25R)- and 18O-labeled (25S)-THCA CoA thioester, or vice versa, with hepatic peroxisomal THCA-CoA oxidases, biotransformed delta 24-THCA was determined by liquid chromatography/atmospheric pressure chemical ionization mass spectrometry. The delta 24-THCA was derived only from (25S)-THCA CoA thioester, indicating that the 25S epimer of THCA is a preferential substrate on dehydrogenation by THCA-CoA oxidases.

Structural analysis of N-linked carbohydrate chains of funnel web spider (Agelenopsis aperta) venom peptide isomerase

The structure of the N-linked carbohydrate chains of peptide isomerase from the venom of the funnel web spider (Agelenopsis aperta) has been analyzed. Carbohydrates were released from peptide isomerase by hydrazinolysis and reductively aminated with 2-aminopyridine. The fluorescent derivatives were purified by phenol/chloroform extraction, followed by size-exclusion HPLC. The structure of the purified pyridylamino (PA-) carbohydrate chains were analyzed by a combination of two-dimensional HPLC mapping, sugar composition analysis, sequential exoglycosidase digestions, and mass spectrometry. The peptide isomerase contains six kinds of N-linked carbohydrate chains of truncated high-mannose type, with a fucose alpha 1-6 linked to the reducing N-acetylglucosamine in approximately 80% of them.

Simultaneous quantitative determination method for sphingolipid metabolites by liquid chromatography/ionspray ionization tandem mass spectrometry

Sphingolipid metabolites ceramide, sphingomyelin, sphingosine, psycosine, sphingosylphosphorylcholine, and dimethylsphingosine were separated and simulataneously quantitated by liquid chromatography/ionspray ionization tandem mass spectrometry (LC/MS/ MS). The use of glassware throughout minimized losses due to adsorption and the pretreatment of this method consisted of simple liquid-liquid extraction procedure with a mixture of chloroform and methanol. After separation on a short C18 silica column eluted in a gradient mode, the metabolites were detected by MS/ MS. This assay allows simultaneously quantification of these metabolites over a range of at least 0.1 to 100 ng/ 10(6) cells. The LC/MS/MS analyses took 10 to 15 min per sample and we could examine up to 50 samples per day. We also detected endogenous sphingosine 1-phosphate in HL-60 cells. The utility of the method was demonstrated by examining changes in metabolites levels in HL-60 cells after treatment with sphingomyelinase. It was found that sphingomyelinase from Bacillus cereus may have selectivity for acyl chain length.

Plasma direct injection high-performance liquid chromatographic method for simultaneously determining E3810 enantiomers and their metabolites by using flavoprotein-conjugated column

A high-performance liquid chromatographic method using the column-switching technique was developed for the simultaneous determination of E3810 and its metabolites (M1-M4). An avidin column was used for in-line pretreatment to exclude plasma proteins, allowing direct injection of a large volume of plasma. A flavoprotein-conjugated chiral stationary phase in a gradient elution mode then gave baseline separation of E3810 and the four metabolites. The enantiomers of E3810 and M3 were also separated. The method is simple, rapid, accurate, and precise. Since no extraction procedure is employed, which might involve different recoveries of different metabolites, no internal standard is necessary. The method was applied to analyze E3810 and its metabolites in plasma after intravenous injection of the drug in beagle dogs.

Vitamin B12 affects non-photic entrainment of circadian locomotor activity rhythms in mice

Administration of vitamin B12 (VB12) has been reported to normalize human sleep-wake rhythm disorders such as non-24-h sleep-wake syndrome (HNS), delayed sleep phase syndrome (DSPS) or insomnia. However, the mechanisms of the action of VB12 on the rhythm disorders are unknown. In the present study, therefore, effects of VB12 on circadian rhythms of locomotor activity were examined in mice. In the first experiment, CBA/J mice were maintained under continuous light condition (LL) or blinded, and after free-running rhythms became stable, the mice were intraperitoneally injected with either VB12 or saline at a fixed time every day. In all the mice with tau > 24 h, saline injections resulted in entrainment of circadian rhythms, whereas not all the mice with tau < 24 h entrained to the injection. In contrast to saline injections, VB12 injections did not always induce entrainment and about half of the mice with tau > 24 h free-ran during the injection. In the second experiment, the amount of phase advances of circadian rhythms induced by a single injection of saline at circadian time (CT) 11 under LL was compared between the mice with and without VB12 silastic tubes. The results showed that the amplitude of phase advances was smaller in the mice with VB12 than those without VB12. In the third experiment, daily injections of saline were given to the mice with VB12 silastic tubes maintained under LL. In this chronic treatment of VB12 as well, attenuating effects of VB12 on saline-induced entrainment were observed. These results suggest that VB12 affects the mechanisms implicated in non-photic entrainment of circadian rhythms in mice.

Context dependent discharge characteristics of saccade-related Purkinje cells in the cerebellar hemispheres of the monkey

In the previous paper (Mano et al, 1991), we reported the discharge patterns of saccade-related Purkinje cells during visually guided saccade task, which were recorded from posterior cerebellar hemisphere, the Crus IIa. In the present study, we analysed these P-cell's simple spike activity during the spontaneous saccade in inter-trial intervals (ITI) of visually guided saccade task, comparing with the activity during the visually guided saccade. We found that the modulation of simple spike discharges during spontaneous saccade was weaker than the modulation during the visually triggered saccade. We recorded single unit discharges of Purkinje cells from cerebellar posterior hemisphere (Crus IIa) in awake Japanese monkeys (Macaca fuscata), trained to perform simple reaction time saccade task gazing at a small light rear-projected on to a tangent screen 54 cm in front of the monkey. Horizontal and vertical eye positions were measured by a corneal search coil method. Comparison of simple spike activity associated with spontaneous saccade during ITI to the activity during visually triggered saccade clarified that the discharge patterns of simple spikes are basically the same during both types of the saccades, but the amount of the phasic modulation (increase of decrease of discharge rate) were larger for all directions (up, down, left and right) during visually guided saccade than that during spontaneous saccade in all saccade-related Purkinje cells so far examined in two monkeys. The modulation, however, cannot be assumed to have been induced by the visual stimulus per se. Because, the maximum increase of simple spike discharge rate aligned at saccade onset is larger than that aligned at target jump. And, the half width of the change was wider when aligned at target light jump than when aligned at the onset of saccades, in all the four directions, indicating the changes of the firing rate were more time-locked to the onset of saccadic eye movements than to the triggering visual stimulus. The present findings suggest that the cerebellar hemisphere plays a more important role in the control of externally triggered voluntary eye movements than in the control of self-initiated, self-paced eye movements. We discussed these findings combining with previous findings on limb movement-related P-cells (Mano et al, 1980, 1986, 1989), from view point of the general role of the cerebellar hemisphere in the control of voluntary movements.

Enantioselective high-performance liquid chromatographic assay for determination of the enantiomers of a new anti-ulcer agent, E3810, in beagle dog plasma and rat plasma

An enantioselective high-performance liquid chromatographic method for the determination of E3810, a new anti-ulcer agent, in Beagle dog plasma and rat plasma has been developed. After extraction from plasma with ethyl acetate, E3810 enantiomers were measured by reversed-phase high-performance liquid chromatography on a Chiralcel OD-R column. The enantiomers were detected by ultraviolet absorbance detection at 290 nm. The recoveries of E3810 enantiomers and internal standard were greater than 91%. The calibration curves were linear from 0.03 to 20 micrograms/ml for Beagle dog plasma and from 0.1 to 100 micrograms/ml for rat plasma. The limits of quantification of both enantiomers were 0.03 micrograms/ml for Beagle dog plasma and 0.1 micrograms/ml for rat plasma. The intra- and inter-day accuracy and precision data showed good reproducibility of the method. The assay was applied for the analysis of E3810 enantiomers in plasma after intravenous administration of racemic E3810 to Beagle dogs and rats. This method should be very useful for enantioselective pharmacokinetic studies of E3810.

Quantitation of platelet-activating factor in biological samples using liquid chromatography/mass spectrometry with column-switching technique

A procedure is described for the fully automated quantitative determination of platelet-activating factor (PAF) using liquid chromatography/fast atom bombardment mass spectrometry (LC/FAB-MS) with two types of column-switching techniques. Various parameters in LC/FAB-MS were optimized, and the use of a microbore column allowed highly selective detection of PAF. A column-switching system was incorporated to minimize band broadening and to increase the permissible injection volume. Analysis of authentic PAF indicated that the limit of quantitation was at the low picogram level (about 50 pg/ml). Another system using both a strong cation-exchange column and an ODS column in tandem was developed for the analysis of PAF in blood samples. These methods were validated with standard samples and applied to the determination of PAF in human polymorphonuclear neutrophils stimulated by addition of a calcium ionophore and in human blood.

Stereospecific dehydrogenation of (25R)- and (25S)-3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-cholestanoic acids by acyl-CoA oxidase in rat liver light mitochondrial fraction

From a stereochemical point of view, the dehydrogenation mechanism of the biotransformation of 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-cholestanoic acid (THCA) into (24E)-3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-cholest-24-enoic acid (delta 24-THCA) has been studied with capillary gas chromatography (GC)/negative ion chemical ionization (NICI)-mass spectrometry. After incubation of (24R,25R)- or (24S,25S)-[24,25-2H2]THCA, synthesized from (24E)-delta 24-THCA by a deuterated diimide reduction, with a rat liver light mitochondrial fraction, 5 beta-cholestanoic acids were extracted and derivatized into a pentafluorobenzyl (PFB) ester-dimethylethylsilyl (DMES) ether. Subsequent resolution into THCA and delta 24-THCA was attained by GC on a cross-linked 5% phenylmethyl silicone fused-silica capillary column monitored with a corresponding characteristic carboxylate anion [M-PFB]- in the NICI mode. The stereospecific elimination of a pro-R hydrogen at C-24 in both (25R)- and (25S)-THCA indicated syn-elimination for the former, whereas anti-elimination for the latter was observed.

Simple and sensitive quantitation method for mevalonic acid in plasma using gas chromatography/mass spectrometry

The combination of gas chromatography and mass spectrometry using a polar capillary column and isobutane chemical ionization made it possible to determine mevalonic acid (MVA) as the lactone at subnanogram levels using 1 mL of plasma. The pretreatment procedure consisted of only three steps, namely lactonization, washing with chloroform and liquid/liquid extraction. This simple, rapid and sensitive method, having good precision and accuracy, is useful for evaluating the change of plasma MVA, which is well correlated with whole-body cholesterol biosynthesis.

Resolution of 4-(4-chlorobenzyl)-2-(hexahydro-1-methyl-1H-azepin-4yl)-1(2H)-phthalazi none enantiomers in plasma with frit-FAB LC-MS using a conalbumin column

A new column-switching method for analysis of drug enantiomers in plasma has been developed with liquid chromatography-frit fast atom bombardment mass spectrometry in combination with a chiral resolution column, which consists of conalbumin (egg-white glycoprotein) immobilized on silica gel and can be used in the reversed-phase separation mode. This method makes it possible to inject a large volume of deproteinized plasma and obtain resolution of drug enantiomers with high sensitivity. The optimum mobile phase, including a non-volatile buffer such as phosphate buffer, for separation of drugs from a large amount of endogenous compounds can be used, because of inclusion of a trapping column with a desalting function. This method is very simple and rapid, and should be very powerful in studies requiring high-sensitivity analysis with chiral separation of drugs from biological samples such as plasma.

Chiral lumazines: preparation, properties, enantiomeric separation

Optically active lumazines (biolumazine, dictyolumazine, monalumazine, and neolumazine) are prepared from the corresponding pterins by enzymatic reaction, using pterin deaminase excreted by Dictyostelium discoideum. The fluorescence properties, circular dichroism spectra, and chromatographic behavior of these lumazines are studied. D- and L-enantiomers of biolumazine, dictyolumazine, and monalumazine are separated using a chiral flavoprotein column. This column also separates the enantiomeric pterins of the threo form: monapterin and dictyopterin. However, the column does not separate the enantiomeric pterins of the erythro form: neopterin and biopterin. By coupling a reverse-phase column to the flavoprotein column, the separation of pterins and lumazines in function of their hydrophobicity, as well as the separation of the diastereomers, is achieved. This coupled achiral/chiral high-performance liquid chromatography method enables determination of the stereoconfiguration of natural lumazines by comparison with optically pure compounds. A lumazine derivative, present in the extracellular medium of Dictyostelium discoideum, is identified as D-dictyolumazine, i.e., 6-(D-threo-1,2-dihydroxypropyl)-lumazine.

Conalbumin-conjugated silica gel, a new chiral stationary phase for high-performance liquid chromatogaphy

A new chiral stationary phase using conalbumin (from chicken egg white) was developed for high-performance liquid chromatography. Chiral resolution of racemic azelastine, an antiallergic drug, was achieved on a conalbumin-conjugated silica gel column. The effects of the pH, the concentration of organic solvents and salts in the mobile phase, and the temperature on the capacity factor and resolution of racemic azelastine were examined. This column shows good stability and can separate optical isomers with an aqueous mobile phase. It should be very useful in studies on pharmacokinetics and in clinical chemistry.

Saccade-related Purkinje cells in the cerebellar hemispheres of the monkey

Extracellular single unit discharges of cerebellar Purkinje cells (P-cells) were recorded from the cerebellar hemispheres of two Japanese monkeys (Macaca fuscata) during spontaneous and visually guided eye movements. We found that saccade-related P-cells, whose simple-spike (SS) discharge rates were modulated in close correlation with saccadic eye movements, were localized in fairly restricted areas in the hemisphere, mostly in Crus IIa with some in the deep folia of Crus I. P-cells located in simple lobules, superficial folia of Crus I or in Crus IIp did not change their discharge rate during voluntary eye movements. Fifty-five saccade-related P-cells recorded from Crus I and II showed modulation of SS discharge rate related to both spontaneous and visually triggered saccades, with the modulation closely time-locked to the saccades. Two thirds (37/55) of saccade-related P-cells began to change their SS discharge rate 20-100 ms prior to the onset of saccades. The remaining one third (18/55) changed their activity approximately at the same time as the saccade onset. These saccade-related P-cells did not show changes in activity during smooth pursuit eye movements, and we did not find any P-cells in the cerebellar hemisphere which showed changes of activity preferentially during smooth pursuit eye movements. In about half (26/55) of the saccade-related P-cells, the pattern of modulation prior to and during saccades was biphasic: increase-decrease or decrease-increase. The other half (29/55) showed monophasic increases or decreases. For a given P-cell, the discharge pattern during saccades was similar for saccades of all directions, though there was a preferred direction in the amount of discharge rate modulation. The present findings suggest that the cerebellar hemisphere (Crus I and IIa) plays an important role in the control of voluntary saccadic eye movements, in addition to other cerebellar cortical areas (flocculus and posterior vermis) which are known to participate in the control of saccades.

Activity of identified wrist-related pallidal neurons during step and ramp wrist movements in the monkey

1. The activity of globus pallidus (GP) neurons (n = 1,117) was studied in two monkeys to reexamine the relation of neuronal activity to movement type (slow vs. fast) while they performed both a visually guided step and ramp wrist tracking task. To select neurons specifically related to wrist movements, we employed both a somatosensory examination of individual body parts and a statistical analysis of the strength of temporal coupling of neuronal discharges to active wrist movement. 2. Neuronal responses to somatosensory stimulation were studied in 1,000 high-frequency GP neurons, of which 686 exhibited clear responses to manipulation of body parts. Of the latter, 336 responded to passive manipulation of forelimb joints and 58 selectively to passive flexion or extension of the wrist. 3. In the external segment of GP (GPe), most neurons responding to passive wrist movement were found to be clustered in four to five adjacent, closely positioned (separated by 200 microns) tracks in single coronal planes. The clusters were irregular in shape with a maximal width of 800-1,000 microns. Separate clusters of neurons responsive to passive wrist movement were identified in planes 3 mm apart in one monkey and in planes 500 microns apart in the other. Multiple clusters of neurons were also found for neurons responsive to joints other than the wrist. These findings suggest a more discrete and complex representation of individual joints in the primate GP than previously conceived. 4. During the performance of the wrist flexion and extension task, 92 neurons showed clear and consistent changes in activity. For these neurons we measured, with a statistical method on a trial-by-trial basis, the strength of temporal coupling between the onset of active wrist movement and the onset of change in neuronal discharge rate. Fifteen neurons showed changes in activity time-locked to the onset of active wrist movement. 5. Twelve pallidal neurons were classified as "wrist-related" based on their movement-locked changes in discharge during task performance and their clear responses to passive wrist joint rotation on examination. All of these neurons exhibited statistically significant modulation of their discharge rate during both fast (peak velocity 97-205 degrees/s) and slow (peak velocity 20-62 degrees/s) wrist movements in the task. The amplitudes of modulation were larger during fast wrist movement than slow movement. These results suggest that the basal ganglia motor circuit plays a similar, rather than an exclusive, role in the control of slow and fast limb movements.

Binding characteristics of a major thyroid hormone metabolite, 3,3',5'-triiodo-L-thyronine, to bovine serum albumin as measured by fluorescence

The interaction between a major thyroid hormone metabolite, 3,3',5'-triiodo-L-thyronine and bovine serum albumin was investigated by fluorescence measurements. The apparent binding constants were obtained at various pHs assuming the equivalence and independence of the interaction sites on the protein from the fluorescence titration curves. The maximum binding was attained at pH 8.0, and the apparent binding constant was (5.28 +/- 0.13).10(5) M-1 with one binding site per albumin molecule. Thermodynamic parameters were also determined from the van't Hoff plot of the apparent binding constants at pH 7.5. The free energy change, enthalpy change and entropy change were -7.70 +/- 0.09 kcal.mol-1, -4.59 kcal.mol-1 and 10.2 e.u., respectively.

Inhibition of mutagenicity by glycyrrhiza extract and glycyrrhizin

The effects of Glycyrrhiza extract and one of its components, glycyrrhizin, on the mutagenicities of several mutagens were investigated by means of a modification of the Ames' test. Both inhibited the mutagenicities of 3-amino-1,4-dimethyl-5 H-pyrido[4,3-b]-indole (Trp-P-1) and 3-amino-1-methyl-5 H-pyrido[4,3-b]indole. Since the Glycyrrhiza extract and glycyrrhizin inhibited the mutagenicity of activated Trp-P-1, it was clear that their inhibitory effects were not due to inhibition of the enzyme activity of the S9 fraction. Both Glycyrrhiza extract and glycyrrhizin also inhibited the mutagenicities of benzo[a]pyrene, 3-methylcholanthrene, 2-naphthylamine, 2-amino-6-methyldipyrido[1,2-a:3',2'-d]-imidazole, dimethylnitrosoamine and dimethylaminoazobenzene. The mutagenicity of 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide (AF-2) was inhibited by the Glycyrrhiza extract but not by glycyrrhizin. This suggested that a component different from glycyrrhizin, present in the Glycyrrhiza extract, inhibited the mutagenicity of AF-2.

Complex-spike activity of cerebellar Purkinje cells related to wrist tracking movement in monkey

Four rhesus monkeys were trained to perform visually guided wrist tracking movements (50). While they performed tasks by wrist flexion or extension from a neutral position, simple-spike (SS) and complex-spike (CS) discharges of a single Purkinje cell (P-cell) were recorded from intermediate and lateral parts of cerebellar hemispheres (lobules IV to VI) ipsilateral to the task-performing wrist. Of approximately 400 P-cells observed, 215 (54%) significantly increased or decreased their SS discharge rate during task performance (task-related P-cells). Of these, 161 were selected for analysis of CS activity; in these P-cells, we could reliably discriminate between CS and background SS by a spike discriminator. The 161 P-cells were further classified into response locked (n = 65) and poorly locked (n = 96) cells according to temporal coupling of the SS frequency modulation to the onset of wrist movements. About 60% of the response-locked P-cells showed a phasic increase (statistical significance level: P less than 0.01) of CS firing rate at the onset of wrist tracking movement. In a few P-cells, a phasic decrease (statistically insignificant) of CS firing rate was observed with the wrist movement. In most P-cells, an increase of CS firing rate was observed with both rapid- and slow-tracking wrist movements. The increase was larger with faster step-tracking movement than with slower ramp-tracking movement. In most P-cells, the CS activity increased with both wrist flexion and extension; in some cells, however, it increased only with either flexion or extension. In most of the response-locked P-cells, the increase of CS firing rate occurred during motor time, i.e., after the onset of the EMG change in prime movers and before the beginning of wrist tracking movement. The increase occurred phasically at the onset and/or at the recovery phase of SS frequency modulation. At neutral wrist position, the maintained frequency of the CS was 0.72 +/- 0.29 CS/s (mean and SD for 161 task-related P-cells). Compared with the frequency at neutral position, the CS frequency did not change tonically during maintained flexed or extended wrist position in any response-locked P-cells. There was no increase of CS firing rate when the monkey returned the handle to center position after completing the tracking task, even in P-cells that had shown a significant increase of CS activity during tracking.(ABSTRACT TRUNCATED AT 400 WORDS)

Simple-spike activity of cerebellar Purkinje cells related to visually guided wrist tracking movement in the monkey

1. Three rhesus monkeys were trained to perform a rapid (greater than 100 degrees/s) and a slow (less than 100 degrees/s) wrist movement guided by a visual cue. While the monkey performed wrist flexion or extension from a neutral position, Purkinje cell (P-cell) discharges were recorded from intermediate and lateral parts of lobules IV--VI of the cerebellum. 2. By the visually guided movement, we could control the direction of the wrist movement; the holding position at three different angles of the wrist joint: neutral, about 30 degrees flexed, and extended; and the velocity in four ranges: a) 10--30, b) 30--100, c) 100--300, and d) 300-650 degrees/s. 3. From 92 P-cells that significantly increased or decreased the discharge rate of simple spikes with task performance, we selected 45 P-cells ("response-locked" cells) as related to the wrist movement by statistical analyses of temporal correlation of P-cell activities to wrist movement. The direction of the frequency modulation (increase or decrease) was in a nonreciprocal fashion with oppositely directed wrist movements (flexion or extension) in 90% of the response-locked P-cells. The maintained frequencies at three holding positions did not significantly differ. 4. Nineteen P-cells changed their spike frequencies temporally locked to both rapid and slow wrist movements. By the discharge pattern in relation to the rapid and slow movements, these cells were classified into two groups. Discharge pattern in group I P-cells (n = 5) conformed very well to that of velocity, and a linear correlation between the instantaneous increase of the discharge rate and velocity was observed in analyses of individual trials. Group II cells showed increase (n = 9) or decrease (n = 5) of firing rate (20--50 spikes/s) larger than group I cells (less than 10 spikes/s) as long as the wrist was moving, even with very slow velocity (less than 30 degrees/s. The correlations between the increase of the discharge rate and the velocity in individual trials were less clear in group II than in group I cells. 5. The present study suggests the importance of the cerebellar cortex in controlling the slow limb movement as well as the rapid movement. The selected P-cells in this study also suggested that the velocity or some dynamic aspect related to the velocity of limb movement is the major information among the dissociated motion parameters coded by the simple-spike frequencies of the P-cells in the cerebellar hemisphere. Whether the latter suggestion represents an essential characteristic of all limb movement-related P-cells or reflects only a feature of a special subgroup among the movement-related cells should be clarified in future experiments.

Changes of simple and complex spike activity of cerebellar purkinje cells with sleep and waking

Action potentials of cerebellar Purkinje cells were observed in intact monkeys during sleep and waking. Purkinje cells exhibit two sorts of action potentials, called simple and complex spikes, and these two sorts of spikes were differently affected by sleep. Simple-spike activity (generated by the parallel fiber inputs to the Purkinje cell) was highest during sleep with rapid eye movements as compared with both waking and sleep with electroencephalographic slow waves. In contrast, complex-spike activity (generated by the climbing fiber inputs to the Purkinje cell) was lowest during sleep with rapid eye movements. The complex action potential of the Purkinje cell consists of an initial large spike followed by one or more smaller secondary spikes, and the number of these secondary spikes was found to be independent of the background discharge frequency of the simple spike. This independence suggests a possible role of presynaptic factors rather than the excitability level of the Purkinje cell itself in determining the number of secondary discharges occurring in the complex spike.