[The effect of O2 therapy on mixed venous concentration of endothelin-1 in chronic obstructive pulmonary disease]

Pulmonary hypertension (PH) is an important factor in the prognosis of cases of chronic obstructive pulmonary disease (COPD), and endothelin-1 (ET-1) is a major factor in the development of PH in COPD. Oxygen (O2) therapy improves the prognosis of COPD by suppressing the development of PH. We therefore assessed the correlation of PH and ET-1, and the effect of O2 therapy on the plasma ET-1 concentration. In COPD patients, the plasma ET-1 level in mixed venous blood, but not in arterial blood, was negatively correlated with mixed venous O2 tension and positively correlated with pulmonary vascular resistance. No such correlation, however, was observed in the case of plasma HANP or plasma BNP. O2 administration significantly suppressed the plasma ET-1 level. This level in mixed venous blood was thought to serve as a marker of PH in COPD. and O2 administration decreased the plasma ET-1 level in mixed venous blood. It consequently attenuated PH.

Effects of CYP3A4 inhibition by diltiazem on pharmacokinetics and dynamics of diazepam in relation to CYP2C19 genotype status

Diazepam is metabolized by CYP2C19 and CYP3A4 in the liver. CYP2C19 shows genetic polymorphism associated with the poor metabolizer (PM) and extensive metabolizer (EM) phenotypes. The aim of this study was to assess the effect of diltiazem, a CYP3A4 inhibitor, on pharmacokinetics and dynamics of diazepam in relation to CYP2C19 genotype status. Thirteen healthy volunteers (eight EMs and five PMs) were given placebo or diltiazem (200 mg) orally for 3 days before and for 7 days after the oral 2-mg dose of diazepam in a double-blind, randomized, crossover manner. The pharmacokinetics and pharmacodynamics of diazepam were assessed with and without diltiazem. Plasma concentrations and area under the plasma concentration-time curves (AUCs) of diazepam and N-desmethyldiazepam were significantly greater in the PM compared with the EM group during the placebo phase. Diltiazem significantly increased AUC and prolonged elimination t(1/2) of diazepam in both the PM and EM groups. These pharmacokinetic changes, however, caused no significant difference in the pharmacodynamics between the two trial phases. Diltiazem affects the pharmacokinetics of diazepam in the PM and EM groups of CYP2C19. Inhibition of CYP3A4 by a concomitant substrate drug like diltiazem may cause a pharmacokinetic interaction with diazepam irrespective of CYP2C19 genotype status, but whether this interaction would reflect a pharmacodynamic change of diazepam remains unconfirmed by our study.

Rho-dependent transfer of Citron-kinase to the cleavage furrow of dividing cells

Citron-kinase (Citron-K) is a Rho effector working in cytokinesis. It is enriched in cleavage furrow, but how Rho mobilizes Citron-K remains unknown. Using anti-Citron antibody and a Citron-K Green Fluorescence Protein (GFP)-fusion, we monitored its localization in cell cycle. We have found: (1) Citron-K is present as aggregates in interphase cells, disperses throughout the cytoplasm in prometaphase, translocates to cell cortex in anaphase and accumulates in cleavage furrow in telophase; (2) Rho colocalizes with Citron-K in the cortex of ana- to telophase cells and the two proteins are concentrated in the cleavage furrow and to the midbody; (3) inactivation of Rho by C3 exoenzyme does not affect the dispersion of Citron-K in prometaphase, but prevented its transfer to the cell cortex, and Citron-K stays in association with the midzone spindles of C3 exoenzyme-treated cells. To clarify further the mechanism of the Rho-mediated transfer and concentration of Citron-K in cleavage furrow, we expressed active Val14RhoA in interphase cells expressing GFP-Citron-K. Val14RhoA expression transferred Citron-K to the ventral cortex of interphase cells, where it formed band-like structures in a complex with Rho. This structure was localized at the same plane as actin stress fibers, and they exclude each other. Disruption of F-actin abolished the band and dispersed the Citron-K-Rho-containing patches throughout the cell cortex. Similarly, in dividing cells, a structure composed of Rho and Citron-K in cleavage furrow excludes cortical actin cytoskeleton, and disruption of F-actin disperses Citron-K throughout the cell cortex. These results suggest that Citron-K is a novel type of a passenger protein, which is dispersed to the cytoplasm in prometaphase and associated with midzone spindles by a Rho-independent signal. Rho is then activated, binds to Citron-K and translocates it to cell cortex, where the complex is then concentrated in the cleavage furrow by the action of actin cytoskeleton beneath the equator of dividing cells.

Comparison of the kinetic disposition of and serum gastrin change by lansoprazole versus rabeprazole during an 8-day dosing scheme in relation to CYP2C19 polymorphism

BACKGROUND

Little is known about differences in the disposition kinetics and pharmacological effects on gastrin levels between lansoprazole and rabeprazole given in a repeated dosing scheme with respect to the polymorphic CYP2C19.

AIM

To provide preliminary information that should be considered when prescribing proton-pump inhibitors (PPIs) for the treatment of acid-related diseases with reference to the CYP2C/9 genotypic status.

METHODS

Helicobacter pylori-negative healthy volunteers were divided into the following three groups (n = 5 each) on the basis of genotyping for CYP2C19: homozygous (hmEMs) and heterozygous extensive metabolizers (htEMs), and poor metabolizers (PMs). All received once-daily 30-mg doses of lansoprazole or 10-mg doses of rabeprazole during an 8-day course in a crossover manner.

RESULTS

The relative values for the area under the serum concentration-time curve (AUC) of lansoprazole and rabeprazole in the hmEMs, htEMs, and PMs after the final doses were 1:1.7:3.9 and 1:1.7:3.8, respectively. The relative AUCs of gastrin in the hmEMs, htEMs, and PMs were 1.6:2.6:3.1 for lansoprazole and 1.6:2.6:2.9 for rabeprazole, respectively.

CONCLUSION

The disposition kinetic behavior of the two PPIs is co-segregated with CYP2C19. The magnitude of CYP2C19-dependent drug availability in the systemic circulation and resulting gastrin response appears to be fairly similar between the two drugs within the same CYP2C19 genotypic groups after a multiple-dosing regimen.

[Incidence and prognosis of, and risk factors for the home-bound in a community elderly population]

This longitudinal study examined numbers of homebound and bed bound individuals over time, and risk factors in a rural community elderly populations. A total of 731 older persons who needed no assistance of another person in traveling from their homes participated in the baseline survey in 1992 and were assessed annually for their ability to travel for subsequent six-years. We defined operationally a homebound status as the necessity for assistance of another person to be able to leave home, but without being bedbound. During the follow-up period, 86 homebound (23.7 per 1,000 person-years) and 32 bedbound cases (8.4 per 1,000 person-years) were noted, the former being 2.8 times more likely to occur. Of the newly bound cases 26% returned to a state capable of leaving home by themselves one year later, and maintained this independent living level even two years later. Of the other cases who remained as homebound or bedbound one year later, only one (1/31) had returned to independent living after two years; most of them became bedbound at home, hospital admitted or deceased. Stepwise multiple logistic regression analysis showed that independent risk factors for the homebound include older age, male gender, slower walking speed, history of hospital admission in the previous year, lower masticatory ability, and higher level of serum beta 2-microglobin. These results indicate that health promotion programs for prevention of becoming homebound among community elderly people should target more intensively assistance to maintaining walking and masticatory ability. In addition, public health professionals should pay more attention to elderly people shortly after hospital discharge.

Variant transthyretin in blood circulation can transverse the blood-cerebrospinal barrier: qualitative analyses of transthyretin metabolism in sequential liver transplantation

BACKGROUND

Although the choroid6 plexus of the brain is one of the most important production sites of transthyretin (TTR), the metabolism of TTR secreted in cerebrospinal fluid (CSF) remains to be elucidated.

METHODS

To perform qualitative analysis of variant TTR in CSF of patients who underwent a sequential liver transplantation using an explanted familial amyloidotic polyneuropathy (FAP) ATTR Val30 Met patient's liver, levels and forms of TTR of the two patients were analyzed by means of enzyme linked immunosorbent assay (ELISA) and matrix-assisted laser desorption/time-of-flight mass spectrometer (MALDI/TOF-MS), respectively.

RESULTS

After the operation, variant TTR levels in serum increased, and in CSF, a significant peak of free form of ATTR Val30 Met was detected in the transplanted patients whose CSF had shown no variant TTR before the operation.

CONCLUSIONS

These findings suggest that the variant TTR can cross-the blood-CSF barrier and migrate into CSF from blood circulation. Because leptomeningeal amyloidosis occurs in FAP ATTR Val30 Met as the progression of the disease, this information suggests that in addition to peripheral neuropathy, disorders of the central nervous system (CNS) should be given an attention in patients who underwent sequential liver transplantation using an explanted FAP ATTR Val30 Met patient's liver.

[HRCT findings for four cases of measles pneumonia]

Although, in Western countries, adult-onset pneumonia that is associated with measles is not rare, reports of its incidence in Japan have been sparse. Among eight adolescent and adult (16-34-year-old) measles patients hospitalized in National Sanatorium Tsuruga Hospital, we found four in whom chest radiography and CT revealed pneumonia. The high-resolution lung CTs of these patients revealed features differing from those characteristic of bacterial pneumonia: bronchial wall thickness, centrilobular nodules in ground glass opacity, interstitial lesions (interlobular septal thickening, fissure thickening, pleural effusion) and lymphadenopathy. Of these findings, the centrilobular nodules in ground glass opacity were marked in these cases, and so this may be the most prominent finding in measles pneumonia; and furthermore, since interlobular septal thickening has not been reported in mycoplasma pneumonia or other atypical pneumonias, it may indicate a measles-specific, virus-induced pneumonia.

Effects of genotypic differences in CYP2C19 status on cure rates for Helicobacter pylori infection by dual therapy with rabeprazole plus amoxicillin

Rabeprazole is a potent proton pump inhibitor and is mainly reduced to thioether rabeprazole by a non-enzymatic pathway and partially metabolized to demethylated rabeprazole by CYP2C19 in the liver. We intended to determine a cure rate for Helicobacter pylori infection by dual rabeprazole/amoxicillin therapy in relation to CYP2C19 genotype status prospectively. Ninety-seven patients with gastritis and H. pylori infection completed the dual therapy with 10 mg of rabeprazole bid and 500 mg of amoxicillin tid for 2 weeks. At 1 month after treatment, cure of H. pylori infection was assessed on the basis of histology, a rapid urease test, culture, polymerase chain reaction (PCR), and 13C-urea breath test. CYP2C19 genotype status was determined by a PCR-restriction fragment length polymorphism method. Of the 97 patients, 33 were homozygous extensive metabolizers (homEM), 48 were heterozygous extensive metabolizers (hetEM), and 16 were poor metabolizers (PM). Cure of H. pylori infection was achieved in 79 of the 97 patients (81.4%, 95%CI = 71.9-88.7). Significant differences in cure rates among the homEM, hetEM, and PM groups were observed; 60.6% (95%CI = 42.1-77.3), 91.7% (95%CI = 80.0-97.7), and 93.8% (95%CI = 69.8-99.8), respectively (P = 0.0007). Twelve patients without cure after initial treatment (10 homEMs and 2 hetEMs) were successfully retreated with rabeprazole 10 mg q.i.d. and amoxicillin 500 mg q.i.d. for 2 weeks. The cure rates for H. pylori infection by dual rabeprazole/amoxicillin therapy depended on the CYP2C19 genotype status. This dual therapy appears to be effective for hetEM and PM patients. However, high dose dual rabeprazole/amoxicillin therapy was effective even for homEM patients. Therefore, the genotyping test of CYP2C19 appears to be a clinically useful tool for the optimal dual treatment with rabeprazole plus amoxicillin.

Pharmacodynamic effects and kinetic disposition of rabeprazole in relation to CYP2C19 genotypes

BACKGROUND

S-mephenytoin 4'-hydroxylase (CYP2C19) catalyses the metabolism of rabeprazole to some extent. Based on the metabolic and pharmacokinetic differences among other proton pump inhibitors such as omeprazole, lansoprazole and pantoprazole, rabeprazole appears to be the least affected proton pump inhibitor by the CYP2C19-related genetic polymorphism.

AIM

To determine whether the pharmacodynamic effects of rabeprazole on intragastric pH and serum gastrin levels, and its pharmacokinetics depend on the CYP2C19 genotype status.

METHODS

Eighteen healthy subjects, whose CYP2C19 genotype status was previously determined, participated in the study. They consisted of six each of homozygous extensive metabolisers (homo EMs), heterozygous extensive metabolisers (hetero EMs), and poor metabolisers (PMs). Helicobacter pylori status was determined by serology. After a single oral dose of 10 mg or 20 mg rabeprazole or water only (baseline data), intragastric pH values were monitored for 24 h. Plasma levels of rabeprazole and serum gastrin were also measured for 24 h post-dose.

RESULTS

Five homo EM, six hetero EM and four PM subjects were H. pylori-negative. After rabeprazole administration, significant differences in intragastric mean pH values, serum gastrin AUC(0-24) and plasma levels of rabeprazole were observed among the three different genotype groups.

CONCLUSION

The pharmacodynamic effects of rabeprazole and its pharmacokinetics depend on the CYP2C19 genotype status.

[Acute eosinophilic pneumonia with positive response to smoking challenge test, suggesting the involvement of health food]

A 17-year-old girl was admitted to our hospital because of acute febrile illness, progressive dyspnea and severe hypoxemia. Chest radiography and HRCT showed bilateral diffuse ground-glass opacities, consolidation, Kerley lines and pleural effusion. Analysis of bronchoalveolar lavage fluid showed 41.9% eosinophils, and a transbronchial lung biopsy revealed infiltration of eosinophils into the alveolar septa and mild alveolar septal edema. The patient's condition was improved immediately by corticosteroid therapy. She had begun smoking and taking health food (chitosan) 3 months before the admission. A smoking challenge test was positive and a drug-induced lymphocyte stimulation test for chitosan was positive. These findings suggested acute eosinophilic pneumonia caused by smoking and health food. The concentration of interleukin-5 (IL-5) in the serum and BALF/granulocyte colony-stimulating factor (G-CSF) in the serum on admission were very high, but decreased after the improvement. Therefore, it is likely that IL-5 and G-CSF are important in the onset of acute eosinophilic pneumonia.

[Clinical significance of sialyl SSEA-1 (SLX) in patients with idiopathic interstitial pneumonia]

Serum SLX levels were measured in 29 patients with idiopathic interstitial pneumonia (IIP) to evaluate its clinical significance. Serum SLX had positive correlations with the BALF neutrophil ratio but not with the severity or the disease activity in patients with IIP, and bronchoalveolar lavage fluid (BALF) SLX had positive correlations with the BALF neutrophil count. Epithelial lining fluid (ELF) SLX levels showed positive correlations with serum SLX, but were much higher. These results suggest that increases of serum SLX may reflect increases of SLX in the lung tissues. Thus, we speculate that increases of the serum SLX level may represent increases of the BALF neutrophil count. Patients with higher SLX showed poor therapeutic responses and poor prognoses in comparison with those with normal SLX for the reason that serum SLX level represents BALF neutrophil level.

Involvement of human liver cytochrome P4502B6 in the metabolism of propofol

AIMS

To determine the cytochrome P450 (CYP) isoforms involved in the oxidation of propofol by human liver microsomes.

METHODS

The rate constant calculated from the disappearance of propofol in an incubation mixture with human liver microsomes and recombinant human CYP isoforms was used as a measure of the rate of metabolism of propofol. The correlation of these rate constants with rates of metabolism of CYP isoform-selective substrates by liver microsomes, the effect of CYP isoform-selective chemical inhibitors and monoclonal antibodies on propofol metabolism by liver microsomes, and its metabolism by recombinant human CYP isoforms were examined.

RESULTS

The mean rate constant of propofol metabolism by liver microsomes obtained from six individuals was 4.2 (95% confidence intervals 2.7, 5.7) nmol min(-1) mg(-1) protein. The rate constants of propofol by microsomes were significantly correlated with S-mephenytoin N-demethylation, a marker of CYP2B6 (r = 0.93, P < 0.0001), but not with the metabolic activities of other CYP isoform-selective substrates. Of the chemical inhibitors of CYP isoforms tested, orphenadrine, a CYP2B6 inhibitor, reduced the rate constant of propofol by liver microsomes by 38% (P < 0.05), while other CYP isoform-selective inhibitors had no effects. Of the recombinant CYP isoforms screened, CYP2B6 produced the highest rate constant for propofol metabolism (197 nmol min-1 nmol P450-1). An antibody against CYP2B6 inhibited the disappearance of propofol in liver microsomes by 74%. Antibodies raised against other CYP isoforms had no effect on the metabolism of propofol.

CONCLUSIONS

CYP2B6 is predominantly involved in the oxidation of propofol by human liver microsomes.

[A case of pulmonary thromboembolism with heparin-induced thrombocytopenia]

In February 2000, a 70-year-old man was admitted to our hospital complaining of back pain and dyspnea on exertion. Pulmonary thromboembolism was diagnosed, and he was treated with intravenous urokinase and heparin. The pulmonary thromboembolism improved, though heparin-induced thrombocytopenia (HIT) was subsequently observed. The thrombocytopenia was then improved by withdrawing the intravenous heparin, but thrombosis appeared extending from both femoral veins to the inferior vena cava. The thrombosis was dispersed by catheter-directed thrombolysis. There have been few reports of HIT in Japan. Heparin is frequently used for the treatment of pulmonary thromboembolism, but special care must be taken, since severe thrombotic complications are associated with HIT.

Effect of genotypic differences in CYP2C19 on cure rates for Helicobacter pylori infection by triple therapy with a proton pump inhibitor, amoxicillin, and clarithromycin

BACKGROUND

Proton pump inhibitors such as omeprazole and lansoprazole are mainly metabolized by CYP2C19 in the liver. The therapeutic effects of proton pump inhibitors are assumed to depend on CYP2C19 genotype status.

OBJECTIVE

We investigated whether CYP2C19 genotype status was related to eradication rates of H pylori by triple proton pump inhibitor-clarithromycin-amoxicillin (INN, amoxicilline) therapy and attempted to establish a strategy for treatment after failure to eradicate H pylori.

METHODS

A total of 261 patients infected with H pylori completed initial treatment with 20 mg of omeprazole or 30 mg of lansoprazole twice a day, 200 mg of clarithromycin three times a day, and 500 mg of amoxicillin three times a day for 1 week. CYP2C19 genotypes of patients were determined with polymerase chain reaction-restriction fragment length polymorphism analysis. Patients without eradication after initial treatment were retreated with 30 mg of lansoprazole four times daily and 500 mg of amoxicillin four times daily for 2 weeks.

RESULTS

Eradication rates for H pylori were 72.7% (95% confidence interval, 64.4%-81.8%), 92.1% (confidence interval, 86.4%-97.3%), and 97.8% (confidence interval, 88.5%-99.9%) in the homozygous extensive, heterozygous extensive, and poor metabolizer groups, respectively. Thirty-four of 35 patients without eradication had an extensive metabolizer genotype of CYP2C19. Nineteen of those patients were infected with clarithromycin-resistant strains of H pylori. However, there were no amoxicillin-resistant strains of H pylori. Re-treatment of H pylori infection with dual high-dose lansoprazole-amoxicillin therapy succeeded in 30 of 31 patients with extensive metabolizer genotype of CYP2C19.

CONCLUSION

The majority of patients without initial eradication of H pylori had an extensive metabolizer CYP2C19 genotype but were successfully re-treated with high doses of lansoprazole and an antibiotic to which H pylori was sensitive, such as amoxicillin, even when the patients were infected with clarithromycin-resistant strains of H pylori.

Stereoselective pharmacokinetics of pantoprazole, a proton pump inhibitor, in extensive and poor metabolizers of S-mephenytoin

Pantoprazole, a proton pump inhibitor, is administered as a racemic mixture. To determine the role of cytochrome P450 (CYP) 2C19 in the stereoselective metabolism of pantoprazole, we investigated the pharmacokinetic disposition of (+)- and (-)-pantoprazole in 7 extensive metabolizers and 7 poor metabolizers of S-mephenytoin. All of the subjects received an oral 40-mg dose of racemic pantoprazole as the enteric-coated formulation. In the extensive metabolizers, the mean clearance of (-)-pantoprazole was only slightly lower than that of (+)-pantoprazole and no significant differences in the other pharmacokinetic parameters between (+)- and (-)-pantoprazole were observed. The mean (+)/(-) ratios for maximum concentration, area under the plasma concentration-time curve from 0 to infinity, and elimination half-life were 0.94, 0.82, and 0.90, respectively. In contrast, in the poor metabolizers, the clearance values of both enantiomers were significantly lower than those in the extensive metabolizers, and a significant difference in pharmacokinetics between (+)- and (-)-pantoprazole was observed. The mean elimination half-life for (+)-pantoprazole was 3.55-fold longer than that of (-)-pantoprazole, and the mean maximum concentration and area under the plasma concentration-time curve from 0 to infinity for (+)-pantoprazole were 1.31- and 3.59-fold greater, respectively, than those for (-)-pantoprazole. These results indicate that the stereoselective metabolism of pantoprazole depends on S-mephenytoin 4'-hydroxylase (CYP2C19). The metabolism of (+)-pantoprazole was impaired to a greater extent than (-)-pantoprazole in the poor metabolizers.

Localization of a mammalian homolog of diaphanous, mDia1, to the mitotic spindle in HeLa cells

mDia1 is a mammalian homolog of Drosophila diaphanous and works as an effector of the small GTPase Rho. It is a member of the formin homology (FH) proteins and contains the Rho-binding domain and an FH3 region in its N terminus, an FH1 region containing polyproline stretches in the middle and an FH2 region in the C terminus. Several lines of evidence indicate that mDia1 and diaphanous are essential in cytokinesis. mDia1 is present in a large amount in the cytoplasm of both interphase and mitotic cells. Using the instantaneous fixation method that preferentially extracts soluble components, we have analyzed localization of mDia1 in mitotic HeLa cells. Immunocytochemistry using polyclonal anti-mDia1 antibody revealed specific immunofluorescence localized to the mitotic spindle. This localization was seen from prophase to telophase. Western blot analysis also detected anti-mDia1 immunoreactivity in the mitotic spindle fraction isolated from mitotic HeLa cells. Consistently, expression of full-length mDia1 as a fusion protein with green fluorescence protein (GFP) revealed the GFP fluorescence again in the mitotic spindle in HeLa cells. Expression of GFP fusions of various truncated mutants of mDia1 identified that this localization is determined by a 173 amino acid-long sequence between the Rho-binding domain and the FH1 region, which contains the C-terminal part of the FH3 region. Point mutation analysis revealed that Leu(434) and Leu(455) in the FH3 region are essential in localization to the mitotic spindle. Neither electroporation of botulinum C3 exoenzyme nor microinjection of Val14RhoA into mitotic cells affected the localization of endogenous mDia1 to the mitotic spindle, suggesting that mDia1 localizes to the mitotic spindle independent of Rho activity. The present study has thus established the mDia1 localization in the mitotic spindle. This localization suggests a role of mDia1 in the spindle-cleavage furrow interaction during cell division.

[Clinical and bacteriological studies on hospital outbreak of Salmonella enteritidis food poisoning]

We experienced a hospital outbreak of salmonella food poisoning after ingestion of omelet which was the hospital evening meal on August 8, 1999. Total number of patients was sixty-two (Male 25: female 37) and the mean age was 52.1 years old. Salmonella Enteritidis was isolated from the stool in 59 cases. Twenty-one of them were associated with the immunosuppression (12 with malignancy, 6 with DM, one with nephrotic syndrome, one with chronic nephritis and one with allergic purpura). Clinical symptoms of the patients were composed of watery diarrhea (100%), fever (88.7%), abdominal pain (82.3%), nausea (45.2%) and vomiting (25.8%). The laboratory data revealed leukocytosis (15/47 = 31.9%), increased CRP (44/46 = 95.7%), elevated creatinin (1/37 = 2.7%) and hypokalemia (5/42 = 11.9%). MICs of 20 strains isolated in our laboratory almost coincided with each other indicating that the source of bacteria was probably the same. In vitro, S. Enteritidis were sensitive to OFLX, TFLX, FOM, most of PCs, CEPs, AGs but resistant to MPIPC, CAM, CLDM, VCM. Therefore we administered LVFX to 59 cases (alone in 45cases, combination with FOM in 6 cases), NFLX to two children and FMOX to one pregnant woman. Lactobacillus was administered to 28 cases (45.2%) and antidiarrhetics were given to 6 cases (9.7%). Finally all patients improved within two weeks. We suspect that the salmonella food poisoning was due to infected egg. The partially cooked omelet would permit the growth of a sufficient inoculum to cause disease. To prevent food poisoning, we have to be consistent in cooking the food well (at 75 degrees C, for more than 1 minute) and should not have omelets during the hot summer season.

Role of CYP2C19 in stereoselective hydroxylation of mephobarbital by human liver microsomes

The 4-hydroxylation of mephobarbital enantiomers was investigated by using human liver microsomes from the extensive metabolizers (EM) and poor metabolizers of CYP2C19. The 4-hydroxylase activity of R-mephobarbital in the EM microsomes was >10 times higher than that of S-mephobarbital. In the poor metabolizer microsomes, the 4-hydroxylase activity of R-mephobarbital was much lower than that in the EM microsomes, and the ratio of 4-hydroxylase activity of R-mephobarbital to that of S-mephobarbital was also lower than that in the EM microsomes. Moreover, the 4-hydroxylase activity of R-mephobarbital showed a high correlation (r = 0.985, p<0.001) with the 4'-hydroxylase activity of S-mephenytoin in a panel of nine human liver microsomes. Anti-CYP2C antibody inhibited R-mephobarbital 4-hydroxylase activity by 85% of the control activity. R-Mephobarbital competitively inhibited S-mephenytoin 4'-hydroxylase activity (K(i) = 34 microM), while S-mephenytoin inhibited R-mephobarbital 4-hydroxylase activity (K(i) = 103 microM). Among the seven cDNA-expressed CYPs studied, only CYP2C19 catalyzed R-mephobarbital 4-hydroxylation. These findings suggest that the 4-hydroxylation of mephobarbital catalyzed by CYP2C19 is preferential for R-enantiomer in human liver microsomes.

[A case of radiologically negative small-cell lung carcinoma successfully detected early by whole-body FDG-PET]

A 68-year-old man was referred to our hospital after being treated for early gastric cancer to investigate the causative malignancy, as his serum carcinoembryonic antigen (CEA) level was increased. Chest radiography showed no abnormal opacities. Subsequently, a whole-body FDG-PET was performed, which detected some tiny lesions in the mediastinum and the right lower lung field. A diagnosis of small-cell lung carcinoma was made after mediastinoscopic and bronchoscopic examinations. After chemoradiotherapy, the previously abnormal uptake of FDG was attenuated and the bronchoscopic appearance was improved, while the serum CEA and NSE levels returned to normal. Our findings demonstrated that whole-body scanning by FDG-PET could be useful for early detection of lung cancer, especially in cases of small-cell lung cancer.

Coordination of microtubules and the actin cytoskeleton by the Rho effector mDia1

Coordination of microtubules and the actin cytoskeleton is important in several types of cell movement. mDia1 is a member of the formin-homology family of proteins and an effector of the small GTPase Rho. It contains the Rho-binding domain in its amino terminus and two distinct regions of formin homology, FH1 in the middle and FH2 in the carboxy terminus. Here we show that expression of mDia1(DeltaN3), an active mDia1 mutant containing the FH1 and FH2 regions without the Rho-binding domain, induces bipolar elongation of HeLa cells and aligns microtubules in parallel to F-actin bundles along the long axis of the cell. The cell elongation and microtubule alignment caused by this mutant is abolished by co-expression of an FH2-region fragment, and expression of mDia1(DeltaN3) containing point mutations in the FH2 region causes an increase in the amount of disorganized F-actin without cell elongation and microtubule alignment. These results indicate that mDia1 may coordinate microtubules and F-actin through its FH2 and FH1 regions, respectively.

Rho-kinase/ROCK is involved in cytokinesis through the phosphorylation of myosin light chain and not ezrin/radixin/moesin proteins at the cleavage furrow

The small GTPase Rho and one of its targets, Rho-kinase (also termed ROK or ROCK), are implicated in various cellular functions including stress fiber formation, smooth muscle contraction, tumor cell invasion and cell motility. We have previously reported that Rho-kinase accumulates at the cleavage furrow during cytokinesis in several cultured cells. Here, using Rho-kinase inhibitors, Y-27632 and HA1077, we found that Rho-kinase is responsible for the phosphorylation of myosin regulatory light chain at Ser19 in the cleavage furrow during cytokinesis. On the other hand, phosphorylation of ezrin/radixin/moesin (ERM) proteins at the cleavage furrow was enhanced by the addition of the above Rho-kinase inhibitors. Treatment with Y-27632 strongly enhanced the accumulation of Rho-kinase but not RhoA and citron kinase at the cleavage furrow. Furthermore, the furrow ingression in cytokinesis was significantly prolonged in the presence of Y-27632. These results suggest that Rho-kinase is involved in the progression of cytokinesis through the phosphorylation of several proteins including myosin light chain at the cleavage furrow.

Decreased zinc ion accumulation by the basidiomycete Lentinus edodes over-expressing L. edodes PriA gene

The information that the deduced expression product of Lentinus edodes priA gene consists of N-terminal hydrophobic sequence, putative zinc-binding motifs and C-terminal membrane-binding-promoting unique sequence led us to analyze its function in L. edodes. Here L. edodes monokaryotic cells over-expressing priA gene were found to exhibit a remarkably decreased accumulation of zinc ion, indicating the involvement of the priA gene in regulation of the intracellular zinc concentration.

Effects of grapefruit juice on the stereoselective disposition of nicardipine in humans: evidence for dominant presystemic elimination at the gut site

OBJECTIVES

To assess relative roles of the intestinal and hepatic stereoselective metabolism of nicardipine in an oral first-pass disposal with and without grapefruit juice intake.

METHODS

The kinetic profiles of (+)- and (-)-nicardipine were studied in the six normal healthy male volunteers who received oral (40 mg) and intravenous (2 mg) racemic nicardipine, first with water and second with grapefruit juice. Both the enantiomers were determined by the stereoselective high-performance liquid chromatographic method, and hemodynamic parameters (arterial blood pressure, heart rate, and electrocardiogram) were assessed when each blood sample was taken.

RESULTS

Grapefruit juice compared with water intake caused a significant (P < 0.05) increase in the mean oral (+)- and (-)-nicardipine bioavailability (Fobs) (48.6+/-5.0% and 105.6+/-7.8%) and dose-absorbed (Fabs) available fraction unmetabolized at the gut (Fg) (48.2+/-5.6% and 110.9+/-8.8%, respectively) with no significant change in the hepatic first-pass effect. However, all of the mean kinetic parameters of both the enantiomers after the intravenous dosing of racemic nicardipine did not differ between the grapefruit juice- and water-intake trial phases. The mean percentage changes in oral AUC (43.1+/-3.4% in [+]-nicardipine and 90.9 6.4% in [-]-nicardipine, or Fobs) and Fabs Fg by grapefruit juice tended to be greater for (-)-nicardipine than for (+)-nicardipine and the mean oral (+)/(-)-nicardipine AUC ratio was significantly reduced by grapefruit juice (from 2.25+/-0.37 to 1.75+/-0.28) (P < 0.05). Except for heart rates, which were greater with grapefruit juice (P < 0.05) at 1 and 2 h after the oral dose of nicardipine, the mean hemodynamic variables did not differ between the two trial phases.

CONCLUSION

We conclude that the gut is the major presystemic disposal site of racemic nicardipine in humans. Grapefruit juice appears to affect this metabolic disposal of (-)-nicardipine to a somewhat greater extent compared with that of (+)-nicardipine, with an early postdose transient tachycardia after the oral dosing of racemic nicardipine.

Genetic polymorphism of UDP-glucuronosyltransferase 2B7 (UGT2B7) at amino acid 268: ethnic diversity of alleles and potential clinical significance

UGT2B7 catalyses the glucuronidation of a diverse range of drugs, environmental chemicals and endogenous compounds. Hence, coding region polymorphisms of UGT2B7 are potentially of pharmacological, toxicological and physiological significance. Two variant UGT2B7 cDNAs encoding enzymes with either His or Tyr at residue 268 have been isolated. The variants, referred to as UGT2B7*1 and UGT2B7*2, respectively, arise from a C to T transversion at nucleotide 802 of the UGT2B7 coding region. Analysis of genomic DNA from 91 unrelated Caucasians and 84 unrelated Japanese demonstrated the presence of the variant alleles encoding UGT2B7*1 and UGT2B7*2 in both populations. However, while there was an approximately equal distribution of subjects homozygous for each allele in the Caucasian population, subjects homozygous for the UGT2B7*1 allele were over 10-fold more prevalent than UGT2B7*2 homozygotes in Japanese. The frequencies of the UGT2B7*1 and UGT2B7*2 alleles were 0.511 and 0.489, respectively, in Caucasians, and 0.732 and 0.268, respectively, in Japanese. The 95% confidence intervals for the two alleles did not overlap between Caucasians and Japanese. Rates of microsomal androsterone, menthol and morphine (3-position) glucuronidation were determined for genotyped livers from Caucasian donors. Statistically significant inter-genotypic differences were not apparent for any of the three substrates. Although the UGT2B7 polymorphism characterized here is probably not associated with altered enzyme activity, the results highlight the need to consider ethnic variability in assessing the consequences of UGT polymorphisms.

Predictors for functional decline among nondisabled older Japanese living in a community during a 3-year follow-up

OBJECTIVES

To examine predictors for functional decline in basic activities of daily living (BADL) as well as predictors for decline in instrumental activities of daily living (IADL) among nondisabled older Japanese people living in a community during a 3-year interval from 1992 to 1995.

DESIGN

A prospective cohort study.

SETTING

A community-based environment.

PARTICIPANTS

A total of 583 men and women aged 65 to 89 at baseline who were independent in both BADL and IADL.

MEASUREMENTS

Independent variables regarding various factors potentially associated with functional decline were obtained from an interview survey and medical examinations at baseline. Dependent variables were functional status in BADL and IADL obtained at the time of the 3-year follow-up.

RESULTS

During the 3-year follow-up, significant predictors for functional decline in BADL and only IADL decline included (1) age of > or = 75, (2) less hand-grip strength, and (3) a history of hospitalization during the past 1 year. In addition, having poor intellectual activities and having poor social roles were identified as significant predictors for functional decline in only IADL during the 3-year follow-up. Furthermore, not having the habit of taking a walk was identified as a significant predictor of functional decline in BADL during the 3-year interval.

CONCLUSION

Having a high level hand-grip strength, good intellectual activities, and good social roles are strongly associated with remaining independence in IADL for the nondisabled Japanese persons aged > or = 65.

Increased secretory leukoprotease inhibitor in patients with nonsmall cell lung carcinoma

BACKGROUND

It is well known that acute pulmonary inflammation, such as that observed in pneumonia, elevates secretory leukoprotease inhibitor (SLPI) levels in serum. A previous report indicated that serum SLPI levels in lung carcinoma patients with concurrent pneumonia were significantly higher than in those in patients whose disease was unaccompanied by pneumonia or in healthy subjects. The authors hypothesized that serum SLPI may increase in patients with lung carcinoma, even carcinoma occurring without pneumonia, and that cells in lung carcinoma might produce SLPI.

METHODS

Serum SLPI levels in 58 patients with primary lung carcinoma unaccompanied by pneumonia and in 42 healthy subjects were measured by an enzyme immunoassay. Twenty-four specimens from 24 of the patients with primary lung carcinoma also were examined immunohistochemically using the rabbit antihuman SLPI antibody.

RESULTS

The results of the current study confirmed that the serum levels of SLPI in patients with primary lung carcinoma were higher than those in healthy subjects, and further found there was no significant correlation between serum SLPI levels and C-reactive protein in lung carcinoma patients without pneumonia. When classifying primary lung carcinoma by its histology, SLPI levels in patients with adenocarcinoma and squamous cell carcinoma were significantly higher than in those in patients with small cell lung carcinoma (SCLC). In patients with nonsmall cell lung carcinoma (NSCLC), the SLPI levels in the advanced group (International Union Against Cancer Stages III and IV disease; n = 35) were significantly elevated compared with the nonadvanced group (Stages I and II disease; n = 12), and such elevated SLPI levels were reduced in some cases by an efficient response to surgical therapy or chemotherapy. Immunohistochemical studies showed that all the NSCLC tissues were stained with anti-human SLPI antibody, whereas staining was not noted in any of the SCLC tissues.

CONCLUSIONS

The authors believe that the findings of the current study demonstrate that cells of NSCLC produce SLPI. Furthermore, they suggest that serum SLPI levels in serum may be a helpful marker in patients with NSCLC unaccompanied by pneumonia, and that SLPI also could be used as an immunohistochemical marker to distinguish between NSCLC and SCLC.

[Evaluation of fluorine-18-fluorodeoxyglucose whole body positron emission tomography imaging in the clinical diagnosis of lung cancer]

In recent years the use of positron emission tomography (PET) with fluorine-18-fluorodeoxyglucose (FDG) has become a valuable tool in the detection of a variety of tumors including lung cancer. To determine its role in the diagnosis of patients with suspected lung cancer, we compared the results of FDG-PET with those of the other scintigraphic imaging techniques (67Ga-planar image, 201Tl-SPECT and 99mTc-bone scintigraphy) used worldwide in patients with lung cancer. The analysis group consists of 178 patients, 159 malignant pulmonary diseases and 19 benign pulmonary diseases. FDG-PET was performed in 65 patients (51 malignant pulmonary diseases, 14 benign pulmonary diseases). FDG-PET had a sensitivity, specificity and accuracy of 98.0%, 78.6% and 93.8%, respectively, in detecting malignant pulmonary nodules. In N staging, sensitivity, specificity and accuracy were 66.7%, 81.3% and 76.0%, respectively. In M staging, the accuracy was 100%. Thus, FDG-PET imaging was more accurate than the other types of scintigraphic imaging. In our observations, whole-body 18FDG-PET images improved diagnostic accuracy in the evaluation of lung lesions and the staging of lung cancer.

Walking speed as a good predictor for the onset of functional dependence in a Japanese rural community population

OBJECTIVE

to investigate and compare the predictive values of four physical performance measures for the onset of functional dependence in older Japanese people living at home.

DESIGN

a population-based prospective cohort study.

SETTING

Nangai village, Akita Prefecture, Japan.

METHODS

out of the population aged 65 years and older living in Nangai (n = 940) in 1992, we measured hand grip-strength, one-leg standing, and usual and maximum walking speeds in 736 subjects who were independent in the five basic activities of daily living. Their functional status was assessed each year for the subsequent 6 years. The outcome event was the onset of functional dependence, defined as a new disability in one or more of the five basic activities of daily living, or death of a subject who had shown no disability at the previous follow-up.

RESULTS

even after controlling for age, sex and a number of chronic conditions, lower scores on each baseline performance measure showed increased risk for the onset of functional dependence. Maximum walking speed was most sensitive in predicting future dependence for those aged 65-74 years, while usual walking speed was most sensitive for people aged > or = 75 years.

CONCLUSION

walking speed was the best physical performance measure for predicting the onset of functional dependence in a Japanese rural older population.

Leukotoxin, 9,10-epoxy-12-octadecenoate, causes pulmonary vasodilation by stimulation of vascular eNOS and iNOS

We have previously reported that leukotoxin, 9,10-epoxy-12-octadecenoate (Lx) dilates rat pulmonary arteries by means of nitric oxide synthase (NOS) activation. In this study, we investigated if Lx stimulates constitutive and/or inducible NOS. We studied the effect of the NOS inhibitors, N(G)-monomethyl-L-arginine and aminoguanidine, as well as endothelium denudation on Lx-induced rat pulmonary arterial dilation and that of aminoguanidine on Lx-induced endothelium denuded lipopolysaccharide (LPS)-treated rat pulmonary arterial dilation and tissue cGMP content. Furthermore, we assessed the effect of aminoguanidine, an inducible NOS (iNOS) inhibitor, on the cGMP content increase induced by Lx in LPS-treated human pulmonary artery smooth muscle cells (HPASMC). The NOS inhibitors and endothelium denudation significantly attenuated Lx-induced vasodilation. Aminoguanidine also significantly attenuated Lx-induced vasodilation in LPS-treated rat denuded pulmonary arteries, and attenuated Lx-induced cGMP content increase in denuded pulmonary arterial rings from LPS-treated rats and in LPS-treated HPASMC. These results suggest that Lx causes pulmonary vasodilation by stimulation of vascular endothelial NOS (eNOS) and iNOS.

Identification of CYP3A4 as the enzyme involved in the mono-N-dealkylation of disopyramide enantiomers in humans

To identify which cytochrome P-450 (CYP) isoform(s) are involved in the major pathway of disopyramide (DP) enantiomers metabolism in humans, the in vitro formation of mono-N-desalkyldisopyramide from each DP enantiomer was studied with human liver microsomes and nine recombinant human CYPs. Substrate inhibition showed that SKF 525A and troleandomycin potently suppressed the metabolism of both DP enantiomers with IC50 values for R(-)- and S(+)-DP of <7.3 and <18.9 microM, respectively. In contrast, only weak inhibitory effects (i.e., IC50 > 100 microM) were observed for five other representative CYP isoform substrates [i.e., phenacetin (CYP1A1/2), sparteine (CYP2D6), tolbutamide (CYP2C9), S-mephenytoin (CYP2C19), and p-nitrophenol (CYP2E1)]. Significant correlations (P <.01, r = 0.91) were found between the activities of 11 different human liver microsomes for mono-N-dealkylation of both DP enantiomers and that of 6beta-hydroxylation of testosterone. Conversely, no significant correlations were observed between the catalytic activities for DP enantiomers and those for the O-deethylation of phenacetin, 2-hydroxylation of desipramine, hydroxylation of tolbutamide, and 4'-hydroxylation of S-mephenytoin. Further evidence for involvement of CYP3A P450s was revealed by an anti-human CYP3A serum that inhibited the mono-N-dealkylation of both DP enantiomers and 6beta-hydroxylation of testosterone almost completely (i.e., >90%), whereas it only weakly inhibited (i.e., <15%) CYP1A1/2- or 2C19-mediated reactions. Finally, the recombinant human CYP3A3 and 3A4 showed much greater catalytic activities than seven other isoforms examined (i.e., CYP1A2, 2A6, 2B6, 2C9, 2D6, 2E1, and 3A5) for both DP enantiomers. In conclusion, the metabolism of both DP enantiomers in humans would primarily be catalyzed by CYP3A4, implying that DP may have an interaction potential with other CYP3A substrates and/or inhibitors.

[Comparative effects of autologous blood transfusion and isovolemic colloids transfusion on hemorrhagic shock: measurement of NO production and tissue oxygen pressure]

Effects of autologous blood transfusion and isovolemic colloids transfusion on hemorrhagic shock model in rats were investigated. The hemorrhagic shock model in rats was prepared by rapid exsanguination and the blood pressure was kept at 40 mmHg for 30 min. As a marker of hemodynamic change, the blood gas analysis was performed, and the tissue oxygen pressure of the liver and the spleen was also measured. Furthermore, we analyzed the changes in NO production in the liver and the spleen of the hemorrhagic shock model. By hemorrhagic shock, Ht, HCO3-, base excess, and PaO2 levels decreased, and liver NO level, but not spleen NO, increased rapidly. However, the liver PtO2 did not show any changes during hemorrhagic shock, although the spleen PtO2 tended to decrease. These changes seen at the hemorrhagic shock were equally restored after the treatment with either autologous blood transfusion or isovolemic colloids transfusion. These results indicate that either autologous blood transfusion or isovolemic colloids transfusion can be useful for the therapy of severe hemorrhagic shock, and the NO production in the liver can participate in the maintenance of homeostasis under hemorrhagic shock.

Expression of receptors for glial cell line-derived neurotrophic factor (GDNF) and neurturin in the inner blood-retinal barrier of rats

The retina is protected from somatic circulation by the blood-retinal barrrier (BRB) composed of tight junctions between retinal vascular endothelial cells (the inner BRB) and those between retinal pigment epithelial cells (the outer BRB). Our recent studies showed that glial cell line-derived neurotrophic factor (GDNF) secreted from astrocytes regulates the permeability of the BBB. In the present study, we immunohistochemically examined the expression of GDNF, neurturin (NTN) and their receptors, GFRalpha1 for GDNF and GFRalpha2 for NTN, because the capillaries of the inner BRB show specialization very similar to the blood-brain barrier (BBB). GDNF and NTN were detected in glial fibrillary acidic protein (GFAP)-positive cells, including Müller cells. GFRalpha1 and GFRalpha2 were localized in von Willebrand factor-positive cells. GDNF and NTN enhanced the barrier function of endothelial cells derived from porcine brain cortex. These results strongly suggest that the barrier function of the BRB is regulated by GDNF and NTN secreted from glial cells, like the BBB.

Effect of Ca(2+)-independent mechanisms on the hypoxic relaxation of guinea-pig tracheal rings

Hypoxia induces bronchodilation in vivo and in vitro, but the mechanisms are still unclear. To evaluate whether an extra- or intracellular free Ca(2+) ion is involved in the mechanisms of hypoxic relaxation, we simultaneously measured cytosolic Ca(2+)levels and tensions in both intact and denuded guinea-pig tracheal strips precontracted with histamine (100 microM), and assessed the effect of hypoxia on guinea-pig tracheal rings precontracted with okadaic acid (10 microM) and calyculin-A (0.1 approximately 10 microM) under an extracellular Ca(2+)-free state. The exposure of tracheal rings to hypoxia induced an immediate decrease of tracheal tension without decrease in intracellular free Ca(2+)levels. In the presence of okadaic acid but not calyculin-A, hypoxic air exposure caused significant transient reductions in tracheal tone. Further, thapsigargin (5 microM or 10 microM) did not affect hypoxic bronchodilation, suggesting that the release of intracellular Ca(2+) does not take a role in hypoxic bronchodilation. Hypoxic dilation decreased ATP content in epithelium-intact rings but not epithelium-denuded rings, indicating a relationship between hypoxic dilation and change of adenine nucleotide in epithelium-intact rings. Our findings indicate that the epithelium dependent mechanisms of hypoxic relaxation of guinea pig tracheal rings preconstricted with histamine may not be related to the mobilization of extra and intra-cellular Ca(2+).

[Benefits of 0.5T MR diffusion-weighted images for super-acute-phase cerebral infarction]

Though diffusion-weighted images (DWI) have been increasingly used to detect super-acute-phase cerebral infarction in recent years, they have primarily been obtained through the use of high magnetic machines of more than 1.5T. In this study, we discussed the usefulness of DWI obtained using 0.5T MRI in comparison with CT, MRI (FLAIR and T2 weighted image) and SPECT (99mTc-HMPAO). DWI were able to detect ischemic lesions earlier than FLAIR or T2-weighted images. Scanning time was short at four seconds for eight slices, and the quality of image was sufficient for clinical usage. The most available b-value seems to be 800. There were less susceptibility artifacts in the 0.5T DWI than in the 1.5T DWI. From these data, we presume that it is possible to detect super-acute-phase cerebral ischemia on the 0.5T DWI, proving the clinical usefulness of DWI. Furthermore, DWI is considered useful in observing chronological changes in cerebral infarction, differentiation of abscess or brain tumor, diagnosis of moyamoya disease, degenerative disease and so on.

Functional transitions in instrumental activities of daily living among older Japanese

We observed functional transitions in instrumental activities of daily living (IADL) over one year among older Japanese and examined factors influencing the deterioration of each IADL. The sources of the study were the first and second panel studies of the Saku Longitudinal Study on Aging, which were done in 1988 and 1989. The study subjects were those participants aged 70 or older. Five IADL items--using public transportation, shopping for daily necessities, preparing meals, paying bills, and managing deposits--were measured in each survey. Deterioration of each IADL item was examined in relation to demographic characteristics such as age, sex, occupational status, living arrangements, and educational status. Of the effective baseline cohort (n = 5,559), 4,892 responded in the second survey (response rate 88%). Over 80% of the respondents who were initially independent in each IADL item remained independent in the second survey. Multiple logistic regression analyses revealed that greater age, having no occupation, and living with children at the baseline were associated with deterioration in each item of IADL. Lower educational status was associated with deterioration in each item of IADL except preparing meals. This study indicates that being engaged in work, living separately from children, and having higher educational status are strongly correlated with remaining independent in IADL for older people aged 70 or older.

Evaluation of psychological effects due to bed rest

The psychological condition of astronauts is an important factor for ensuring mission success in limited space. Head-down tilting bed rest is a well-accepted method by which to simulate an acute stage of human adaptation to the weightless state in space flight. In our previous studies, the enhancement of depressive and neurotic levels occurred during a 20-day horizontal bed rest. In this study, we attempted to examine the depressive and neurotic levels, the mood status, and behavioral tendency of the subjects and to analyze the changes of 24-hour urinary excretion of 17-hydroxycorticosteroid-glucronides (17-OHCS) for an indicator of changes in the endocrine system due to physical and psychological stress during a 20-day 6-degrees head-down tilting bed rest (BR).

[Behavioral competence among community dwelling older people with disability in basic activities of daily living]

This study observed the status of independence in behavioral competence among older people who have any disability in basic activities of daily living (BADL) living in a rural community in Japan. Study participants (N = 76) who were regarded as bedridden were surveyed by means of a questionnaire in July to August 1996. The independence variables were age, sex, BADL status, hearing impairment, visual impairment, history of stroke, and cognitive impairment. The dependent variable was each item of the Tokyo Metropolitan Institute of Gerontology (TMIG) Index of Competence, which is a multidimensional 13-item index of behavioral competence. Percentages of subjects who were independent in each item of the TMIG Index of Competence varied from 1% to 36%. Multiple logistic regression analyses revealed that BADL status was independently associated with independence in using a telephone, being interested in news stories or programs dealing with health, being called on for advice, and initiating conversations with young people, after adjustment for age, sex, hearing impairment, visual impairment, history of stroke, and cognitive impairment. These findings suggest that programs for preventing decline in behavioral competence of older people with BADL disability might be important as well as physical therapy for them.

[Risk of acute hospitalization among long-term home care patients]

To determine the factors that influence acute hospitalization among long-term home care patients, all patients (N = 59) who were provided home visiting nursing and/or medical care from a 169-bed community hospital in Saitama, Japan, between May 1989 and April 1993 were followed until November 1993. Data on patients concerning age, sex, diagnosis of primary disease, ability to perform activities of daily living (ADL), intellectual impairment, serum albumin, frequency of home visiting medical care, medical and nursing care provided at the patient's home were collected from the medical charts of each subject. The main outcome measure was onset of acute hospitalization during a one-year period after initiation of home visiting medical care. Thirty-five patients (59%) were admitted due to acute illness. Compared with patients who were not in need of acute hospitalization. Cox's proportional hazard model revealed that patients who were completely dependent for eating, dressing, and using the toilet (Hazard ratio (HR) = 3.13, 95% confidence interval (CI) = 1.34-7.35) and serum albumin less than 3.5 g/dl (HR = 3.05, 95% CI = 1.37-6.77) were more likely to be hospitalized. Evaluating a patient's physical conditions at the beginning of home visiting care may allow us to predict whether the patients will have to be hospitalized during the following one-year period.

Cure of refractory duodenal ulcer and infection caused by Helicobacter pylori by high doses of omeprazole and amoxicillin in a homozygous CYP2C19 extensive metabolizer patient

A 53-year old female patient with duodenal ulcer and Helicobacter pylori infection was treated three times with a proton pump inhibitor-based triple therapy, such as lansoprazole-clarithromycin-amoxicillin (INN, amoxicilline) and lansoprazole-minocycline-cefaclor. However, the H pylori infection was not cured. A culture test revealed that her infection was a clarithromycin-resistant but amoxicillin-sensitive strain of H pylori. Moreover, a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis revealed that she was a homozygous extensive metabolizer of cytochrome P450 (CYP) 2C19 (wt/wt). The usual dose of the proton pump inhibitor was therefore assumed to be insufficient for her and then she was treated with a high dose of omeprazole (120 mg/day) and amoxicillin (2,250 mg/day) for 2 weeks. The H pylori infection and the ulcer lesion were then cured. One of the factors associated with success or failure of cure of H pylori infection by the proton pump inhibitor-based triple therapy appeared to be CYP2C19 genotype status. Dual treatment with a sufficient dose of a proton pump inhibitor plus amoxicillin could cure H pylori infection even after the failure to cure H pylori infection by a usual proton pump inhibitor-based triple therapy in patients with the wt/wt homozygous extensive metabolizer genotype of CYP2C19.

[The usefulness of serum KL-6 levels for the diagnosis of disease activity in idiopathic interstitial pneumonia]

Serum KL-6 levels were measured in 29 patients with idiopathic interstitial pneumonia (IIP) as a means of evaluating disease activity. Levels of serum KL-6 were significantly higher in patients with active IIP (n = 11) than in those with inactive IIP (n = 18). The levels of serum KL-6 were 2,546 +/- 1,703 U/ml in patients with active IIP and 795 +/- 385 U/ml in patients with inactive IIP, respectively. The levels of serum LDH, CEA, P-III-P, and 7 S collagen in patients with active IIP did not differ significantly from those in patients with inactive IIP. For the diagnosis of active IIP, the sensitivity of serum KL-6 (cut off value of 1,500 U/ml) was 81.8% and the specificity, 94.4%. These results were almost identical to findings obtained with chest Ga-67 scintigraphy. Furthermore, they suggested that serum KL-6 levels may be a useful marker for the diagnosis of disease activity in IIP, as well as a useful indicator for the administration of steroid therapy to patients with IIP.

[The clinical study on KL-6 and SP-D in sera of patients with various pulmonary diseases]

It has been reported that serum levels of KL-6 and surfactant protein D(SP-D) can be useful indicators for interstitial pneumonia(IP). In the present study, we evaluated the clinical significance of KL-6 and SP-D by measuring the serum levels of patients with various pulmonary diseases by enzyme-linked immunosorbent assay. Serum levels of KL-6 in patients with idiopathic interstitial pneumonia(IIP), collagen disease with interstitial pneumonia(CDIP), lung cancer(LC) and LC with idiopathic interstitial pneumonia were significantly higher than of those in healthy controls. Moreover, serum levels of KL-6 were significantly higher in patients with active IP than in those with inactive IP. Serum levels of SP-D in patients with IIP and CDIP were significantly higher than of those in healthy controls. When a cut-off level of KL-6 or SP-D in sera was defined as a value of healthy controls representing the means + 2SD, the serum KL-6 positive diagnostic rate for IP(79.2%) was higher than that of SP-D(66.7%). The SP-D positive diagnostic rate for lung diseases other than IP(11.6%) was lower than that of KL-6(34.9%). The serum concentration of KL-6 in patients with the pulmonary diseases significantly correlated with that of SP-D. These findings suggest that KL-6 may be superior in the sensitivity of IP and can be used to evaluate the disease activity of IP. In addition, SP-D may be more specific for IP than KL-6.

Cigarette smoking, N-acetyltransferase 2 acetylation status, and bladder cancer risk: a case-series meta-analysis of a gene-environment interaction

Tobacco use is an established cause of bladder cancer. The ability to detoxify aromatic amines, which are present in tobacco and are potent bladder carcinogens, is compromised in persons with the N-acetyltransferase 2 slow acetylation polymorphism. The relationship of cigarette smoking with bladder cancer risk therefore has been hypothesized to be stronger among slow acetylators. The few studies to formally explore such a possibility have produced inconsistent results, however. To assess this potential gene-environment interaction in as many bladder cancer studies as possible and to summarize results, we conducted a meta-analysis using data from 16 bladder cancer studies conducted in the general population (n = 1999 cases), Most had been conducted in European countries. Because control subjects were unavailable for a number of these studies, we used a case-series design, which can be used to assess multiplicative gene-environment interaction without inclusion of control subjects. A case-series interaction odds ratio (OR) > 1.0 indicates that the relationship of cigarette smoking and bladder cancer risk is stronger among slow acetylators as compared with rapid acetylators. We observed an interaction between smoking and N-acetyltransferase 2 slow acetylation (OR, 1.3; 95% confidence interval, 1.0-1.6) that was somewhat stronger when analyses were restricted to studies conducted in Europe (OR, 1.5; confidence interval, 1.1-1.9), a pooling that included nearly 80% of the collected data. Using the predominantly male European study population and assuming a 2.5-fold elevation in bladder cancer risk from smoking, we estimated that the population attributable risk percent was 35% for slow acetylators who had ever smoked and 13% for rapid acetylators who had ever smoked. These results suggest that the relationship of smoking and bladder cancer is stronger among slow acetylators than among rapid acetylators.

A critical role for a Rho-associated kinase, p160ROCK, in determining axon outgrowth in mammalian CNS neurons

We tested the contribution of the small GTPase Rho and its downstream target p160ROCK during the early stages of axon formation in cultured cerebellar granule neurons. p160ROCK inhibition, presumably by reducing the stability of the cortical actin network, triggered immediate outgrowth of membrane ruffles and filopodia, followed by the generation of initial growth cone-ike membrane domains from which axonal processes arose. Furthermore, a potentiation in both the size and the motility of growth cones was evident, though the overall axon elongation rate remained stable. Conversely, overexpression of dominant active forms of Rho or ROCK was suggested to prevent initiation of axon outgrowth. Taken together, our data indicate a novel role for the Rho/ROCK pathway as a gate critical for the initiation of axon outgrowth and the control of growth cone dynamics.

Pharmacological properties of Y-27632, a specific inhibitor of rho-associated kinases

Y-27632 [(+)-(R)-trans-4-(1-aminoethyl)-N-(4-pyridyl)cyclohexanecarboxamide++ + dihydrochloride] is widely used as a specific inhibitor of the Rho-associated coiled-coil forming protein serine/threonine kinase (ROCK) family of protein kinases. This study examined the inhibition mechanism and profile of actions of Y-27632 and a related compound, Y-30141 [(+)-(R)-trans- 4-(1-aminoethyl)-N-(1H-pyrrolo[2, 3-b]pyridin-4-yl)cyclohexan-ecarboxamide dihydrochloride]. Y-27632 and Y-30141 inhibited the kinase activity of both ROCK-I and ROCK-II in vitro, and this inhibition was reversed by ATP in a competitive manner. This suggests that these compounds inhibit the kinases by binding to the catalytic site. Their affinities for ROCK kinases as determined by K(i) values were at least 20 to 30 times higher than those for two other Rho effector kinases, citron kinase and protein kinase PKN. [(3)H]Y-30141 was taken up by cells in a temperature- and time-dependent and saturable manner, and this uptake was competed with unlabeled Y-27632. No concentrated accumulation was found, suggesting that the uptake is a carrier-mediated facilitated diffusion. Y-27632 abolished stress fibers in Swiss 3T3 cells at 10 microM, but the G(1)-S phase transition of the cell cycle and cytokinesis were little affected at this concentration. Y-30141 was 10 times more potent than Y-27632 in inhibiting the kinase activity and stress fiber formation, and it caused significant delay in the G(1)-S transition and inhibition of cytokinesis at 10 microM.

Citron, a Rho target that affects contractility during cytokinesis

The small GTPase Rho, which regulates cell shape, is thought to contribute to cytokinesis. Recently, Citron was characterized as a Rho target. This large protein contains a Ser/Thr kinase domain related to that of ROCK, another Rho effector. Both endogenous Citron and recombinant Citron localize to the cleavage furrow in dividing cells and to the midbody in post-mitotic cells. Moreover, overexpression of Citron deleted from its C-terminal sequence caused abnormal contractions specifically during cytokinesis, resulting in the formation of multinucleated cells. Cell shape, F-actin, intermediate filaments, and microtubules appeared essentially normal in these cells during interphase. Thus, Citron is a Rho effector that appears to function during cytokinesis, modulating its contractile process. In brain, however, Citron is highly expressed in a subset of neurons as a brain-specific isoform that lacks a kinase domain, Citron-N. This protein accumulates in synapses and associates to the NMDA receptor via interaction with the adaptor protein PSD95, suggesting that the function of Citron is specialized in the neurons.

Effect of sildenafil citrate (Viagra) on erectile dysfunction in a patient with familial amyloidotic polyneuropathy ATTR Val30Met

A 34-year-old male patient with familial amyloidotic polyneuropathy (FAP) amyloidogenic transthyretin (ATTR) Valine30Methionine (Val30Met), who underwent a liver transplantation in Sweden in 1994, was treated with sildenafil citrate (Viagra) to ameliorate his erectile dysfunction (ED). Some clinical symptoms and the examination data for autonomic functions were improved after liver transplantation, but ED was never improved after the operation. Five years after liver transplantation, he requested a sildenafil citrate therapy to enhance his erectile potential. One and a half hours after the administration of 25 mg of sildenafil citrate, the skin surface temperature around the pelvic area increased and the penis became erect, though the postdose hemodynamic parameters did not significantly change from the respective baseline or predose values. He was able to have sexual intercourse, though ejaculation did not occur. This case report appears to suggest that sildenafil citrate is an effective drug to treat ED in patients with an organic impairment of the autonomic nervous system without altering systemic circulation.

Therapeutic relevance of pharmacogenetic factors in cardiovascular medicine

The variability in the individual response to drugs may be due either to interindividual variations in the pharmacokinetics of the drugs or to the heterogeneity of the mechanism(s) underlying the diseases, or both. In both cases, genetic heterogeneity is involved in the metabolism of cardiovascular drugs and pathogenesis of inherited cardiovascular disorders. Molecular genetic technologies can now provide sensitive and efficient genetic testing, not only to identify polymorphic drug metabolism genes, but also to identify disease-associated genes for diagnosis and risk stratification of many hereditary cardiovascular diseases. In this review, we discuss the polymorphic metabolism of cardiovascular drugs and the molecular genetics of cardiovascular diseases in relation to the genes determining the responsiveness to a given drug.

Lack of differences in diclofenac (a substrate for CYP2C9) pharmacokinetics in healthy volunteers with respect to the single CYP2C9*3 allele

OBJECTIVES

Evidence exists to suggest that diclofenac is metabolised by CYP2C9. The present study was undertaken in order to evaluate the effect of the single CYP2C9*3 variant on drug metabolism using diclofenac as a probe drug.

METHODS

A single dose of diclofenac was administered orally to 12 healthy subjects in whom the genotype of CYP2C9 had been determined previously. The disposition kinetics of diclofenac were compared between homozygotes for the wild type (CYP2C9*1/*1, n = 6) and heterozygotes for the Leu359 variant (CYP2C9*1/*3, n = 6).

RESULTS

For diclofenac, the following kinetic parameters were observed in the CYP2C9*1/*1 and CYP2C9*1/*3 subjects, respectively (mean +/- SD): apparent oral clearance (ml/kg/h) 355.8 +/- 56.9 and 484.4 +/- 155.3; area under plasma concentration time curve (microg h/ml) 2.7 +/- 0.7 and 1.9 +/- 0.6. The formation clearance of 4'-hydroxydiclofenac (ml/kg/h) was 63.6 +/- 19.1 in the CYP2C9*1/*1 subjects compared with 75.9 +/- 27.6 in the CYP2C9*1/*3 subjects. There were no significant differences in any of the kinetic parameters for either diclofenac disposition or formation clearance of 4'-hydroxydiclofenac between the two genotype groups.

CONCLUSION

Since the disposition kinetics of diclofenac does not change in subjects with the single CYP2C9*3 mutant allele, it is suggested that the effects of CYP2C9 polymorphisms on the drug metabolism tend to be substrate specific.