Prolactin-induced expression of TATA-less cyclin D3 gene is mediated by Sp1 and AP2

The TATA-less cyclin D3 gene is stimulated by prolactin (PRL) in rat Nb2 T-lymphocytes. DNA mobility shift assay and luciferase transfection analysis revealed that the gene has a potential promoter region, two enhancer domanins and a silencer region. The promoter region possessed three Sp1 sites and two AP2 sites, and both enhancer regions had one AP2 binding site each. Analysis using oligonucleotide probes and purified AP2 protein has suggested that the expression of rat cyclin D3 gene is promoted by Sp1 and AP2 factors.

Nicotinic alpha 7 receptors protect against glutamate neurotoxicity and neuronal ischemic damage

The alpha7 receptor agonist dimethoxybenzylidene anabaseine (DMXB) protected rat neocortical neurons against excitotoxicity administered 24 h before, but not concomitantly with, NMDA. This action was blocked by nicotinic but not muscarinic antagonists. DMXB (1 mg/kg i.p.) also reduced infarct size in rats when injected 24 h before, but not during, focal ischemic insults. In a mecamylamine-sensitive manner, alpha7 receptors appear neuroprotective in non-apoptotic model.

Correlation between steady-state plasma concentrations of mianserin and trazodone in depressed patients

OBJECTIVE

The correlations between steady-state plasma concentrations of mianserin and its active metabolite desmethylmianserin and those of trazodone and its active metabolite m-chlorophenylpiperazine (m-CPP) were examined in 19 depressed patients.

METHODS

Ten patients received first mianserin (30 mg per day) and second trazodone (150 mg per day), while 9 patients received these treatments in the opposite sequence, with at least 2-week intervals between the two phases. Blood was sampled at steady state, 1-3 weeks after initiation of each treatment. Plasma concentrations of mianserin, the separate enantiomers S(+)- and R(-)-mianserin, desmethylmianserin, trazodone and m-CPP were measured by means of high-performance liquid chromatography.

RESULTS

There was a significant correlation between steady-state plasma concentrations of trazodone and total mianserin (r = 0.59) or S(+)-mianserin (r = 0.57), but not R(-)-mianserin (r = 0.33).

CONCLUSION

The present study thus suggests that the metabolic capacity of mianserin, especially the more active S(+)-enantiomer, and that of trazodone correlate to each other. This finding supports the previous suggestions that cytochrome P4502D6 is involved in the metabolism of mianserin and trazodone.

Clinical pilot study of intrahepatic arterial chemotherapy with methotrexate, 5-fluorouracil, cisplatin and subcutaneous interferon-alpha-2b for patients with locally advanced hepatocellular carcinoma

To evaluate the efficacy of methotrexate (MTX)-5-fluorouracil (5-FU), cisplatin (CDDP), and interferon-alpha-2b(IFN alpha-2b) combination therapy, we conducted a clinical pilot study in patients with locally advanced hepatocellular carcinoma (HCC). Sixteen patients, who had received no prior treatment for the HCC, with portal tumor thrombosis in the main trunk or in the major branch were enrolled in the study. IFN alpha-2b (3 x 10(6) units) was injected subcutaneously 3 times per week. After a bolus administration of MTX (30 mg/m2), CDDP (75 mg/m2) and thereafter 5-FU (750 mg/m2) were given weekly by intrahepatic arterial infusion. In 15 eligible patients, there were 1 complete response (CR) and 6 partial responses (PR) with a response rate of 46.7%. Median survival of the 15 patients was 7 months, and the 2-year survival rate of CR and PR patients was 57.1%. There was severe transient hematologic toxicity. More than grade 2 nausea/vomiting was noted in > 50%. In conclusion, the IFN alpha-2b combination chemotherapy demonstrated good response in patients with locally advanced HCC. This treatment should be tried in a controlled study.

[Inflammatory pseudotumor of the ureter: a case report]

A 57-year-old male was admitted because of the right flank pain. The image examinations, retrogradeurography, abdominal CT and MRI, showed a mass located at the upper right ureter. Although the tumor was not typical as ureteral cancer, we could not make a diagnosis of a benign tumor by image examinations. Therefore nephroureterectomy that was surgical method for ureteral cancer was performed. The tumor was diagnosed as inflammatory pseudotumor of the ureter by histological findings. Inflammatory pseudotumor is extremely rare for ulogeital organs. And this lesion is difficult to distinguish from malignancy only by image examinations. Therefore, the surgical resection and pathological studies are necessary.

The CYP2D6 genotype and plasma concentrations of mianserin enantiomers in relation to therapeutic response to mianserin in depressed Japanese patients

The relationship between therapeutic response to racemic mianserin and steady-state plasma concentrations of S(+)- and R(-)-mianserin was studied in 26 Japanese patients with major depression. The daily dose of mianserin was 30 mg, and the duration of treatment was 3 weeks. Regarding S-mianserin, the proportion of responders (final Montgomery-Asberg Depression Rating Scale score of 10 or less) was significantly higher in the plasma concentration range of 10 to 23 ng/mL than outside (10 of 11 vs. 3 of 15, p = 0.0005). Such a plasma concentration difference between responders and nonresponders was not found for R-mianserin. In 15 patients, the relationships between the CYP2D6 genotype, determined by allele-specific polymerase chain reaction analysis and Escherichia coli RI restriction fragment length polymorphism, plasma concentrations of the enantiomers, and the therapeutic response were studied. Five patients were homozygous for the wild type (wt) allele (wt/wt), nine were heterozygous for the CYP2D6Ch (Ch) allele causing decreased CYP2D6 activity (Ch/wt), and one patient was heterozygous for the Ch allele and the defect allele CYP2D6D (D) (Ch/D). The Ch/wt group showed significantly higher plasma concentrations of S-mianserin (mean +/- SD: 15 +/- 6 vs. 8 +/- 1 ng/mL, p = 0.007) and proportion of responders (8 of 9 vs. 1 of 5, p = 0.023) than the wt/wt group. The patient with the Ch/D genotype had the highest plasma concentration of S-mianserin (37 ng/mL) and a poor response. No significant relationship was found between the CYP2D6 genotype and plasma concentration of R-mianserin. The study presented here thus suggests that the CYP2D6 genotype plays a major role in controlling plasma concentration of the S-enantiomer of mianserin, which contributes to a major extent to the antidepressant effect during mianserin treatment.

A new concept of dynamic orthosis for paraplegia: the weight bearing control (WBC) orthosis

A new concept of device, termed the weight-bearing control (WBC) orthosis, has been designed with three major needs in mind; a rigid frame that supports the user's body weight, a special hip joint device that reciprocally propels each leg forward, a gas powered foot device that varies the sole thickness of the device for foot/floor clearance, and control system of the orthosis. A paraplegic (T7 level complete paraplegia, sensory evoked potential silent, response to electro-stimulation on the cortical area of the brain also silent) who has tested this WBC orthosis has been able to walk without fatigue at a high speed for a greater distance than before. In walking tests of this WBC orthosis, he achieved a maximum walking speed of 34.1 m/min for a distance of 10 metres. The walking distance reached 521 m with an average walking speed of 21.2 m/min without rest on one small tank of CO2 liquid gas, measuring 10 cm in length and 3 cm in diameter.

Effects of adenosine receptor subtypes on hippocampal extracellular serotonin level and serotonin reuptake activity

To clarify the effects of adenosine receptor subtypes (A1, A2, and A3) on hippocampal serotoninergic function, hippocampal extracellular serotonin (5-HT) levels were determined by in vivo microdialysis in freely moving rats under various conditions. Both adenosine and an adenosine A1 receptor agonist, 2-chloro-N6-cyclopentyladenosine, decreased extracellular 5-HT levels, whereas an adenosine A1 receptor antagonist, 8-cyclopentyl-1,3-dimethylxanthine (CPT), and caffeine increased these levels. A selective A2A receptor agonist (CGS-21680), an adenosine A2 receptor agonist (PD-125944), an adenosine A2 receptor antagonist, 3,7-dimethyl-1-propargylxanthine (DMPX), and an adenosine A3 receptor agonist, N6-2-(4-aminophenyl)ethyladenosine (APNEA), did not affect extracellular 5-HT levels. When the adenosine A1 receptor was blocked by CPT, the hippocampal extracellular 5-HT level was increased by adenosine, CGS-21680, and PD-125944, and decreased by caffeine, DMPX, and APNEA. When both adenosine A1 and A2 receptors were blocked by CPT and DMPX, the extracellular 5-HT level was decreased by adenosine, caffeine, and APNEA. The hippocampal extracellular 5-HT level was not affected by administration of APNEA alone, but was decreased by this agent when the adenosine A1 receptor was blocked, irrespective of whether the adenosine A2 receptor was functional. These inhibitory effects of adenosine, caffeine, and APNEA on extracellular 5-HT levels, during both adenosine A1 and A2 receptor blockade, were inhibited by selective 5-HT reuptake inhibitors. These results indicate that the stimulatory effects of the adenosine A2 receptor and the inhibitory effects of the A3 receptor on hippocampal extracellular 5-HT levels are masked by the inhibitory effects of the adenosine A1 receptor.

Metabolic disposition of pantoprazole, a proton pump inhibitor, in relation to S-mephenytoin 4'-hydroxylation phenotype and genotype

OBJECTIVES

To assess the possible relationship between the metabolic disposition of pantoprazole and genetically determined S-mephenytoin 4'-hydroxylation phenotype and genotype.

METHODS

The pharmacokinetic disposition of pantoprazole was investigated in 14 Japanese male volunteers (seven extensive and seven poor metabolizers of S-mephenytoin). All subjects received a single 40 mg oral dose of pantoprazole as the enteric-coated formulation.

RESULTS

An interphenotypic difference in the metabolic disposition of pantoprazole was observed: the mean values for area under the concentration-time curve (AUC), elimination half-life (t1/2), and apparent oral clearance were significantly (p < 0.01) greater, longer, and lower, respectively, in the poor metabolizers than in the extensive metabolizers. The mean AUC of pantoprazole sulfone was greater (p < 0.01) in the poor metabolizers than in the extensive metabolizers, whereas the mean AUC of the main demethylated metabolite (M2) was lower (p < 0.01) in the poor metabolizers than in the extensive metabolizers. A significant negative correlation was observed between the individual values for log10% urinary excretion of 4'-hydroxymephenytoin and AUC of pantoprazole (rs = -0.816; p < 0.005). The CYP2C19 genotyping test results were found to be in a complete accordance with the phenotypes.

CONCLUSION

These data indicated that the metabolic disposition of pantoprazole is under the pharmacogenetic control of S-mephenytoin 4'-hydroxylase (CYP2C19).

Cloning and functional analysis of rat cyclin D2 promoter: multiple prolactin-responsive elements

Structure and function of the promoter region of rat cyclin D2 gene were investigated by cloning, sequence analysis and DNA mobility shift assay using nuclear extracts of prolactin-stimulated Nb2 cells. The results show that the expression of rat cyclin D2 gene is not dependent on the TATA-box but is stimulated by multiple transcription factors induced by prolactin at an immediate-early stage of the cell cycle.

[Alcoholic effect on male sexual function]

Though an adequate volume of ethanol relieves nervousness and enhances sexual desire, acute administration of a great deal of ethanol suppresses central nervous system and causes sensory torpor and penile erectile dysfunction. Long term and excessive intake of ethanol causes central and/or peripheral neuropathy and sexual dysfunction; atrophy of testicles, low serum level of testosterone, impaired spermatogenesis and penile erectile dysfunction. It also invades various organs in digestive tract, cardiovascular system, central and peripheral nervous system and causes functional disorders in these organs. Successful treatment of patients with penile erectile dysfunction should be performed with treatment of these underlying and associated disease.

[Effects of human atrial natriuretic peptide on hemodynamics and pulmonary gas exchanges in cardiac surgery patients]

We investigated the effects of human atrial natriuretic peptide (hANP) on hemodynamics and pulmonary gas exchanges in 22 cardiac surgery patients without pulmonary hypertension. In 10 patients, hANP was infused at a rate of 0.2 microgram.kg-1.min-1 throughout the surgery (hANP group), while in other 12 patients hANP was not infused at all (control group). Before cardiopulmonary bypass (CPB), mean arterial pressure and systemic vascular resistance decreased and cardiac output increased significantly in hANP group as compared with those in control group. After weaning from CPB and at the completion of surgery there was no significant difference in these hemodynamic variables between the two groups. Mean pulmonary arterial pressure, pulmonary vascular resistance, arterial pH, arterial oxygen tension, arterial carbon dioxide tension and shunt ratio did not show any significant difference between the two groups throughout surgery. These findings indicate that hANP infusion causes greater systemic vasodilation with less pulmonary vasodilation, and suggest that this systemic vasodilating effect contributes to the improvement of left ventricular function in patients undergoing open heart surgery.

Involvement of peribiliary glands in primary sclerosing cholangitis: a histopathologic study

We examined the histological changes of the peribiliary glands (PBGs), a hitherto pooly recognized anatomical element around the biliary tree, in 7 cases of primary sclerosing cholangitis (PSC). These glands showed proliferation, and nonspecific inflammation with lymphoplasmacytic infiltration, fibrosis, and destruction. In addition, there were cystic lesions around the bile ducts, and they were considered to reflect dilatation of the PBGs. These changes were found around the intrahepatic and extrahepatic bile ducts in the cases examined. It is of interest that changes in the PBGs tended to correlate with the inflammatory changes of the bile duct wall itself, though 2 cases showed changes in the duct walls and PBGs unrelated to their distribution along the biliary tree. These findings suggest that the PBGs are also a target structure in addition to the bile ducts themselves in PSC.

L-DOPA neurotoxicity is mediated by glutamate release in cultured rat striatal neurons

The exposure of cultured rat striatal neurons to L-DOPA caused marked cell death. The L-DOPA cytotoxicity was inhibited by the addition of Mg2+ to and by the removal of Ca2+ from the culture medium, and also by the application of tetrodotoxin. Moreover, prolonged application of L-DOPA increased the glutamate content in the culture medium. These results indicate that L-DOPA produces neurotoxicity by facilitating glutamate release.

[Pitfall in 201Tl-99mTc subtraction scintigraphy: a case of 99mTc-pertechnetate uptake in a parathyroid hyperplasia]

201Tl-99mTc subtraction scintigraphy has been recognized as a useful procedure in the preoperative localization of hyperfunctioning parathyroid glands. We experienced a case which showed 99mTc-pertechnetate uptake in a parathyroid hyperplasia. This case warned us to focus a lot of attention on the detection for preoperative localization. There has been no such case reported in the previous Japanese literatures. Hypervascularity and thick fibrous capsule presumed explanation for a rare case of marked pertechnetate uptake into a parathyroid hyperplasia.

Effects of thioridazine, an inhibitor of CYP2D6, on the steady-state plasma concentrations of the enantiomers of mianserin and its active metabolite, desmethylmianserin, in depressed Japanese patients

The antidepressant mianserin is administered as a racemate of the S(+)- and R(-)-enantiomers. Previous in-vitro studies have suggested that CYP2D6 is involved in the stereoselective metabolism of mianserin and its active metabolite, desmethylmianserin. To determine a role for CYP2D6 in vivo, the effects of thioridazine, an inhibitor of CYP2D6, on the steady-state plasma concentrations of the enantiomers of mianserin and desmethylmianserin were examined in 13 depressed Japanese patients. All patients were taking 30 mg of racemic mianserin at bedtime for 8-50 days. Thioridazine (40 mg/day) was coadministered for 1 week, and blood samplings were performed before and after thioridazine coadministration, 12 h after bedtime dosing. Plasma concentrations of the enantiomers of mianserin and desmethylmianserin were measured by HPLC, and the CYP2D6 genotype was determined by allele-specific PCR analysis. Thioridazine significantly increased plasma concentration of S(+)-mianserin (mean SD: 78.2 +/- 35.0 vs. 150.8 +/- 48.7 nM, P < 0.001), but not R(-)-mianserin (39.8 +/- 21.2 vs. 39.5 +/- 20.6 nM, NS). Thioridazine also significantly increased plasma concentrations of both S-desmethylmianserin (11.9 +/- 2.8 vs. 24.4 +/- 10.7 nM, P < 0.01) and R-desmethylmianserin (42.6 +/- 28.4 vs. 115.6 +/- 36.9 nM, P < 0.001). One patient homozygous for the defective allele CYP2D6*5 had the second highest and highest plasma concentrations of S(+)-mianserin and R-desmethylmianserin, respectively, before thioridazine coadministration, and exhibited little increase in plasma concentration of the drugs after thioridazine coadministration. These results suggest that thioridazine specifically inhibits the metabolism of S(+)-mianserin and R-desmethylmianserin, probably through inhibition of CYP2D6, but not R(-)-mianserin.

Induction of minisatellite mutation in NIH 3T3 cells by treatment with the tumor promoter okadaic acid

Okadaic acid (OA) is a strong tumor promoter of mouse skin carcinogenesis and also a potent inhibitor of serine/threonine protein phosphatases. OA induces various genetic alterations in cultured cells, such as diphtheria-toxin-resistance mutations, sister chromatid exchange, exclusion of exogenous transforming oncogenes, and gene amplification. The present study revealed that it caused minisatellite mutation (MSM) at a high frequency in NIH 3T3 cells, although no microsatellite mutation was found. Nine of 31 clones (29%) exhibited MSM after 6 days of OA treatment, as opposed to only 1 of 30 clones (3%) without OA exposure. Moreover, NIH 3T3 cells treated with OA acquired tumorigenicity in nude mice, giving rise to 7 tumors within 25 weeks in 20 sites where 3 x 10(6) cells were injected. In contrast, the same numbers of untreated cells gave rise to only one tumor, and the tumor grew much slower. All of three OA-induced tumors examined manifested the MSM. The findings thus point to a molecular mechanism by which OA could function as a tumor promoter, and also the biological relevance of the induction of MSM in the tumorigenic process by OA.

Biphasic effects of carbamazepine on the dopaminergic system in rat striatum and hippocampus

To clarify the effects of carbamazepine (CBZ) on dopamine (DA) release and their metabolism, the extracellular and total levels of DA, its metabolites (DOPAC and HVA) and precursor, 3,4-dihydroxyphenylalanine (DOPA) in the striatum and hippocampus were studied. DA re-uptake and DOPA accumulation in the striatum and hippocampus, and monoamine oxidase (MAO) activities were also determined. After acute and chronic administrations of CBZ, the plasma concentration of CBZ associated with therapeutic activity increased the extracellular and total levels of all substances determined, whereas supratherapeutic concentration of CBZ decreased extracellular and total levels of all substances. Neither therapeutic nor supratherapeutic concentrations of CBZ affected MAO-A nor -B activities, nor DA re-uptake. DOPA accumulation caused by NSD1015 was inhibited by therapeutic and supratherapeutic concentrations of CBZ. These results suggest that a therapeutic concentration of CBZ enhances DA turnover, whereas a supratherapeutic concentration of CBZ inhibits DA turnover. These effects of CBZ on dopaminergic systems may be, at least partially, involved in the mechanisms of action of CBZ.

Relationship between the CYP2D6 genotype and the steady-state plasma concentrations of trazodone and its active metabolite m-chlorophenylpiperazine

The relationship between the cytochrome P450 (CYP) 2D6 genotype and the steady-state plasma concentrations (Css) of trazodone and its active metabolite m-chlorophenylpiperazine (mCPP) was studied in 54 depressed Japanese patients receiving trazodone 150 mg at bedtime. By use of allele-specific PCR analysis, the wild type allele, three mutated alleles causing absent enzyme activity (CYP2D6A, CYP2D6B and CYP2D6D) and one mutated allele causing decreased enzyme activity (CYPZD6 Ch) were identified. The means (ranges) of the Css of trazodone, corrected to the median body weight in 17 cases with no mutated allele, 27 cases with one mutated allele and 10 cases with two mutated alleles, were 556 (281-1115), 643 (302-1362) and 671 (234-1418) ng/ml, respectively, while the values of mCPP were 60 (35-121), 65 (33-99) and 58 (38-112) ng/ml, respectively. Neither the Css of trazodone (F = 0.80, P = 0.45) nor that of mCPP (F = 0.49, P = 0.61) significantly differed among the three groups. The present study thus suggests that the CYP2D6 genotype cannot predict the Css of these compounds.

Effects of non-toxic and toxic concentrations of phenytoin on monoamines levels in rat brain

To clarify the mechanisms of the antiepileptic activity of phenytoin (PHI), the effects of PHT on extracellular and total levels of monoamines (dopamine and serotonin), in rat striatum and hippocampus were studied. The plasma concentrations of PHT associated with therapeutic activity did not affect striatal and hippocampal extracellular levels of monoamines, whereas supratherapeutic concentrations of PHT decreased striatal and hippocampal extracellular levels of monoamines, in a concentration dependent manner. Toxic concentrations of PHT produced generalized seizures 'paradoxical intoxication' and an initial drastic decrease in striatal and hippocampal extracellular levels of monoamines before seizure onset, whereas the extracellular monoamines levels increased after seizures. In addition, the therapeutic concentrations of PHT did not affect monoamine turnover, whereas supratherapeutic concentrations of PHT inhibited monoamine turnover. These results suggest that monoaminergic transmission may not be involved in the antiepileptic mechanism of action of PHT, and that dysfunction of monoaminergic transmission can produce generalized tonic-clonic convulsions. Thus, the present study suggests that 'Paradoxical Intoxication' induced by toxic concentrations of PHT, at least partially, can be mediated by hypo-monoaminergic function in the brain.

Microsatellite instability occurs infrequently in sporadic renal cell carcinoma

Forty-nine sporadic renal cell carcinomas were screened for instability at nine different microsatellite loci. Three tumors (6.1%) showed alterations at more than one locus. One chromophobe-cell renal carcinoma showed microsatellite instability at 3 loci and was considered to exhibit a replication error-positive phenotype. Two of the tumors with clear-cell histology showed minor alterations at one of the nine loci examined, These data indicate that microsatellite instability occurs infrequently in sporadic RCC and that the mutator phenotype may be involved in rare instances such as the chromophobe-cell carcinoma.

Nicotine protects cultured cortical neurons against glutamate-induced cytotoxicity via alpha7-neuronal receptors and neuronal CNS receptors

We examined the effects of nicotine on glutamate-induced cytotoxicity using primary cultures of rat cortical neurons. The cell viability decreased significantly when cultures were exposed to glutamate for 10 min and then incubated with glutamate-free medium for 1 h. The exposure of cultures to nicotine (10 microM) for 8-24 h prior to glutamate application ameliorated the glutamate-induced cytotoxicity, with no significant effect of nicotine alone on the cell viability. Neuroprotection by nicotine was dependent on the incubation period. alpha-bungarotoxin (alpha-BTX) and methyllycaconitine (MLA), both of which are alpha7-neuronal receptor antagonists, and dihydro-beta-erythroidine (DHbetaE), a neuronal central nervous system (CNS) receptor antagonist, each significantly antagonized the protection by nicotine against glutamate-induced cytotoxicity. Ionomycin, a calcium ionophore, and S-nitrosocysteine (SNOC), a nitric oxide (NO) donor, also induced cytotoxicity in a manner similar to glutamate. Nicotine protected cultures against ionomycin-induced cytotoxicity, but not against SNOC-induced cytotoxicity. These results suggest that nicotine protects cultured cortical neurons against glutamate-induced cytotoxicity via alpha7-neuronal receptors and neuronal CNS receptors by reducing NO-formation triggered by Ca2+ influx.

Human hepatitis B virus enhancer 1 is responsive to human interleukin-6

Serum levels of interleukin-6 (IL-6) are elevated in acute and chronic hepatitis B patients. The effect of IL-6 and its transcription factor of NF-IL6 (a nuclear factor for IL-6) on hepatitis B virus (HBV) enhancer 1 (Enh1), which controls HBV X expression, were investigated in HepG2 cells. Twenty ng/ml of IL-6 increased 4-fold the enhancer activity of Enh1 according to the CAT assay. The IL-6 stimulation was abolished by introducing a mutation either in an AP-1-related site or a C-stretch sequence in the Enh1 sequence, demonstrating that the cis-elements are necessary for the IL-6 response. Co-transfection of NF-IL6 expression plasmid similarly increased the enhancer activity of Enh1 through both binding sites. Further, a specific complex formation of the Enh1 was detected using HepG2 nuclear lysates by electromobility shift assays, and the complex formation was increased in the lysates of cells treated with IL-6 and NF-IL6-transfection. In competition assays, one half of the complex formed was found to remain in the presence of 500-times excess competitor DNA fragment harboring NF-IL2 binding site, suggesting indirect binding of NF-IL6 to the Enh1 sequence. These results indicate that IL-6 increased the enhancer activity of HBV Enh1 through signal transduction pathways, indirectly involving NF-IL6, and may control HBV X expression and viral replication in HBV infected liver.