Metabolism of barnidipine hydrochloride, a potent calcium antagonist, in rat and dog

1. In vitro experiments in the rat indicated that barnidipine was metabolized extensively in the liver and was catalyzed by P450s. 2. After oral dosing, nine metabolites were identified in the urine and bile of rat and dog. No unchanged drug was detected in urine and bile. Ester hydrolysis and pyridine formation were the main metabolic pathways in urine in both species, whereas glucuronide conjugates of the debenzylated metabolite and the hydrolyzed pyrrolidine ester were noted in bile. 3. The metabolism of barnidipine in the rat and dog were qualitatively similar. Metabolites are generated by one or several of the following pathways: (a) N-debenzylation of the side chain, (b) hydrolysis of the pyrrolidine ester, (c) oxidation of the dihydropyridine ring to a pyridine ring, (d) hydrolysis of the methylester, (e) reduction of the nitro group to the amino group, and (f) conjugation of the generated metabolites with glucoronic acid.

Kalimantacins A, B and C, novel antibiotics from Alcaligenes sp. YL-02632S. I. Taxonomy, fermentation, isolation and biological properties

Novel antibacterial antibiotics, kalimantacins A, B and C, have been isolated from the fermentation broth of Alcaligenes sp. YL-02632S. In this paper, the taxonomy of the producing strain, fermentation, isolation and biological activities of kalimantacins are reported. Kalimantacins inhibit the growth of Staphylococcus aureus and S. epidermidis including multiple-drug resistant strains.

Kalimantacin A, B, and C, novel antibiotics produced by Alcaligenes sp. YL-02632S. II. Physico-chemical properties and structure elucidation

Kalimantacin A, B and C are new antibiotics produced by Alcaligenes sp. YL-02632S. Their structures were elucidated to be novel long chain structure compounds containing O-carbamoyl, amide and carboxylic acid moieties based on various 2D NMR experiments and MS analysis.

Intra-arterial infusion therapy following alteration of pelvic blood flow and concurrent radiation therapy for invasive bladder cancer

Intra-arterial infusion therapy following alteration of pelvic blood flow and concurrent radiation therapy was performed in 13 patients with muscle invading bladder cancer (T2, 2; T3, 6; T4, 5). The internal iliac artery of the opposite side was embolized and the ipsilateral gluteal and obturator arteries were embolized by metallic coils. A catheter was placed in the ipsilateral internal iliac artery. CDDP was administered daily at a dose of 7-9 mg/body over 1 minute. Radiation was done by Microtron using 10 MV x-ray. Total dose was 4500-7060 cGy. Evaluation was done by cystoscopy, radiography and biopsy. Eight patients achieved complete response (CR) histologically. Others had partial response (PR). All CR patients had no recurrence. The observation period was between 3 and 29 months, with a mean of 11 months. This treatment modality is effective for locally advanced bladder cancer.

YM-47141 and YM-47142, new elastase inhibitors produced by Flexibacter sp. Q17897. II. Structure elucidation

YM-47141 and YM-47142 are new elastase inhibitor produced by Flexibacter sp. Q17897. These structures were elucidated by MS and NMR spectral analysis. YM-47141 and YM-47142 were the cyclic peptides containing tricarbonyl moiety hydrated on the center carbonyl carbon in DMSO-d6.

Human pro-tumor necrosis factor: molecular determinants of membrane translocation, sorting, and maturation

Human pro-tumor necrosis factor (pro-TNF) is a type II transmembrane protein with a highly conserved 76-residue leader sequence. We have analyzed the behavior, both in a microsomal translocational system and by transfection, of a series of mutants with deletions from the cytoplasmic, transmembrane, and linking domains. Cytoplasmic deletions included the Arg doublet at -49 and -48 and/or the Lys doublet at -58 and -57; additional mutants included deletion of residues -73 to -55 and -73 to -55, -49, and -48. The transmembrane and linking domain mutants included deletions in the -42 to -35 region, combined with the deletion of residues -32 to -1. Two hybrid mutants combined the cytoplasmic deletions with the deletion of residues -32 to -1. All of the cytoplasmic deletion mutants were properly translocated, as were the transmembrane deletion mutants with deletions up to residues -36, -35, -32 to -1, although the last one exhibited reduced efficiency; further incremental deletions, including deletions of residues -38 to -35 and -32 to -1, completely blocked translocation. Both hybrid mutants were effectively translocated; furthermore, transfection analysis revealed competent expression and maturation of both the cytoplasmic and hybrid mutants. Thus, proper expression and maturation of human pro-TNF can be accomplished with as few as approximately 12 of the 26 residues of the native transmembrane domain and with a net negative charge in the cytoplasmic domain flanking the transmembrane region.

Partial purification and characterization of the porcine brain enzyme hydrolyzing and synthesizing anandamide

Anandamide (arachidonylethanolamide) is known as an endogenous agonist for cannabinoid receptors. An amidohydrolase, which hydrolyzed anandamide, was solubilized from the microsomal fraction of porcine brain with 1% Triton X-100. The enzyme was partially purified by Phenyl-5PW hydrophobic chromatography to a specific activity of approximately 0.37 mumol/min/mg of protein at 37 degrees C. As assayed with 14C-labeled substrates, the apparent Km value for anandamide was 60 microM, and anandamide was more active than ethanolamides of linoleic, oleic, and palmitic acids. Ceramidase and protease activities were not detected in our enzyme preparation. The purified enzyme also synthesized anandamide from free arachidonic acid in the presence of a high concentration of ethanolamine with a specific activity of about 0.16 mumol/min/mg of protein at 37 degrees C. On the basis of cochromatographies, pH dependence, heat inactivation, and effects of inhibitors such as arachidonyl trifluoromethyl ketone, p-chloromercuribenzoic acid, diisopropyl fluorophosphate, and phenylmethylsulfonyl fluoride, it was suggested that the anandamide amidohydrolase and synthase activities were attributable to a single enzyme protein.

Possible neuronal origin of ATP release evoked by forskolin and ouabain from guinea-pig atrial segments

The characteristics of ATP release evoked by forskolin and ouabain from atrial segments of guinea-pig were evaluated under electrical stimulation. Forskolin (1 microM) produced a massive release of ATP together with a positive inotropic response. Both 30 microM W-7 (N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide.HCI), a calmodulin antagonist, and 30 microM vinblastine, a mitotic inhibitor, markedly inhibited the evoked release of ATP without affecting the evoked contraction. However, 100 microM N-ethylmaleimide abolished completely the basal and drug-evoked ATP release and further the evoked contraction. Both the ATP release and contraction evoked by ouabain (3 microM) were similarly affected by W-7, vinblastine and n-ethylmaleimide. The release of ATP, but not the contraction, evoked by forskolin was strongly suppressed by 10 microM okadaic acid, a protein phosphatase inhibitor. The suppression by okadaic acid of the evoked release was thoroughly antagonized in the presence of 0.01 microM PMA (phorbol 12-myristate 13-acetate), but not 10 microM H-7 (1-(5-isoquinolinesulfonyl)-2-methylpiperazine). These results suggest that forskolin, like ouabain, may dominantly cause the neuronal release of ATP from cardiac adrenergic nerves, although the possible participation of release from muscular sources cannot be ignored.

High nitric oxide synthase activity in endothelial cells in ulcerative colitis

Endothelial nitric oxide (NO) synthase, a unique NO synthase (NOS) isoform that is expressed constitutively by the vascular endothelium both in vivo and in vitro, is believed to be essential to systemic and/or local vascular integrity. NOS expression by endothelial cells may indicate vascular activation. We successfully established a simple method for the culture of microvascular endothelial cells from a small amount of tissue and investigated ulcerative colitis (UC), in which condition vascular factors have not been studied extensively. We cultured endothelial cells from the mesenteries of surgical patients with UC and assayed NOS activity by reduced nicotinamide adenine dinucleotide phosphate (NADPH)-diaphorase histochemistry. Strong NOS activity was demonstrated in the cells from all UC patients (5/5), whereas no activity was detected in the cells from human umbilical veins and the mesenteries of colon cancer patients (0/10 and 0/5, respectively). This strong NOS activity was not diminished by incubation with a high concentration of glucocorticoid, suggesting that it was constitutive. These results indicate a close relationship of vascular activation (high NOS activity) with the pathogenesis of UC.

A new strategy of gene trapping in ES cells using 3'RACE

"Gene trapping" in embryonic stem (ES) cells is a novel approach to identify a series of genes in mammals concomitant with the production of the corresponding mutant mice. However, this approach is currently unable to identify genes that are not expressed in ES cells. Here we describe a strategy to identify gene trapping clones which is not based on expression of a reporter gene. It uses the neor gene which lacks a polyadenylation signal and has a splice donor signal. Expression of the neor gene as fusion transcripts with the 3' end containing the polyadenylation signal of tagged genes allows the identification of these clones by 3' rapid amplification of the cDNA end in undifferentiated ES cells, even if the genes are not expressed in ES cells. Amplification was observed in about 25% of G418-resistant clones. Sequence analyses suggested the amplifications represent gene trapping events. The feasibility of this approach was further assessed by analysing one clone, PAT-12, in detail.

SV40-adenovirus immortalized cell lines derived from mouse lymphoid dendritic cell preparations

Dendritic cells (DC) are antigen-presenting cells characteristic in their rarity and potent ability to stimulate resting T cells. We established several cell lines from purified mouse spleen DC and Langerhans' cells (LC) by infecting them with recombinant SV40ori(-)-adenovirus. Using this method, cells from these fractions are efficiently transformed at a frequency as high as 5 x 10(-6). Some established lines have dendritic morphology, express surface markers specific for DC (defined by mAb 33D1 and NLDC145) and weak substrate adherence. Interestingly, these lines simultaneously express B cell markers (B220 and Ly-1) and/or macrophage markers (Mac-1 and F4/80). Among the lines, OT6.2 and OT8.3.1 have retained stimulating activity in mixed lymphocyte reactions (MLR) which is attributable to the primary T cell stimulating activity of native DC. However, these lines also present soluble antigens to T cell clones, a secondary T cell stimulating activity, characteristic of B cells and macrophages. Although transformation has perturbed the functional discreteness of the DC cell lineage, DC-specific properties are partially preserved in the cell lines. These cell lines may provide useful experimental systems for the elucidation of molecular mechanisms involved in the MLR and the differentiation of DC.

ATP release evoked by isoprenaline from adrenergic nerves of guinea pig atrium

Mode and site of release of ATP evoked by isoprenaline were evaluated in the electrically driven left atrial segment of guinea pig. The peak release of ATP 5 min after 1 microM isoprenaline was inhibited by 1 microM propranolol and 1 microM butoxamine, but not by 1 microM atenolol, showing that the ATP release is due to stimulation of the presynaptic beta 2-adrenoceptor by isoprenaline. The maximum ATP release was markedly reduced by Ca2+/calmodulin antagonists, W-7 and trifluoperazine, and by a mitotic inhibitor, vinblastine. Further, the release was similarly inhibited by myosin light chain kinase inhibitors, ML-7 and wortmannin. Nifedipine, a Ca(2+)-channel blocker, decreased the release of ATP evoked by isoprenaline. By contrast, Bay K 8644, a Ca(2+)-channel opener, tended to enhance the ATP release. These findings suggest that isoprenaline produces ATP release from adrenergic nerve terminals of atrium, implying that ATP serves as a co-transmitter.

Lipoxygenase-catalyzed oxygenation of arachidonylethanolamide, a cannabinoid receptor agonist

Various purified lipoxygenases were incubated with [14C]arachidonylethanolamide which is an endogenous ligand for cannabinoid receptors. When radioactive products were analyzed by thin-layer chromatography, porcine leukocyte 12-lipoxygenase and rabbit reticulocyte and soybean 15-lipoxygenases produced polar compounds at about the same reaction rates as that of oxygenation of free arachidonic acid. In contrast, the reaction of human platelet 12-lipoxygenase proceeded at a much lower rate, and porcine leukocyte 5-lipoxygenase was totally inactive. The result indicated that the lipoxygenases, which had been shown previously to be capable of oxygenating esterified polyunsaturated fatty acids, were also active with the arachidonylethanolamide. High-performance liquid chromatography, ultraviolet and mass spectrometry and nuclear magnetic resonance spectroscopy identified the major product by leukocyte 12-lipoxygenase as 12-hydroperoxy-5,8,10,14-eicosatetraenoylethanolamide and that by 15-lipoxygenases as 15-hydroperoxy-5,8,11,13-eicosatetraenoylethanolamide. The 15-hydroxy derivative inhibited electrically-evoked contraction of mouse vas deferens with an IC50 of 0.63 microM as well as arachidonylethanolamide (0.17 microM), but the 12-hydroxy derivative was much less effective.

Binding of oligoguanylate to scavenger receptors is required for oligonucleotides to augment NK cell activity and induce IFN

Specific palindromic sequences in synthetic oligonucleotides are required to induce IFN and augment IFN-mediated natural killer activity. To study the mechanism of IFN induction by oligonucleotides containing palindromic sequences, we investigated the possible target molecules of the oligonucleotides. Oligo-1, a 30mer single-stranded oligonucleotide with oligoG sequences next to the active palindromic sequence (AACGTT), had more activity than oligonucleotides with oligoA, oligoC, or oligoT sequences. The activity of oligo-1 was inhibited by a guanine homo-oligomer (G30), dextran sulfate, and polyvinyl sulfate. Oligo-1 bound to plastic-adherent mouse splenocytes, and the binding was inhibited by G30, dextran sulfate, and polyvinyl sulfate. Oligo-1 inhibited acetyl-LDL binding to the scavenger receptor on mouse splenocytes. These findings suggest that the binding of an extrapalindromic sequence to the scavenger receptor is required for the immunostimulatory activity of oligo-1.

Atrioventricular nodal physiology after slow pathway ablation

The AV nodal physiology before and 1 week after "slow pathway potential" guided catheter ablation was examined in 32 patients with AV nodal reentrant tachycardia. A mean of 4.9 applications of radiofrequency energy eliminated AV nodal reentrant tachycardia in all patients. There were no significant differences in sinus cycle length (815 +/- 159 msec vs 813 +/- 162 msec; P = NS) and fast pathway conduction properties before and 1 week after ablation. Slow pathway conduction was completely eliminated in 10 (31%) (group I) of 32 patients after ablation. In the remaining 22 patients residual slow pathway conduction associated with one AV node echo was observed. In 15 patients (47%) (group II), the effective refractory period of the slow pathway showed a change of < 30 msec (265 +/- 51 vs 266 +/- 51 msec; P = NS), and in 7 patients (22%) (group III), a prolongation of more than 80 msec (247 +/- 56 vs 340 +/- 42 msec; P = 0.0001) before and 1 week after ablation. Minimal and maximal A2-H2 interval over the slow pathway in group II was not significantly changed (Min A2-H2: 241 +/- 37 vs 247 +/- 40 msec; P = NS, Max A2-H2: 346 +/- 79 vs 350 +/- 60 msec; P = NS), while a significant prolongation was measured in group III (Min A2-H2: 261 +/- 53 vs 373 +/- 107 msec; P < 0.01, Max A2-H2: 359 +/- 41 vs 427 +/- 63 msec; P < 0.05) before and after ablation.(ABSTRACT TRUNCATED AT 250 WORDS)

Radiofrequency catheter ablation of atrioventricular accessory pathways in Wolff-Parkinson-White syndrome with drug-refractory and symptomatic supraventricular tachycardia--its high effectiveness irrespective of accessory pathway location and properties

Radiofrequency catheter ablation of atrioventricular accessory pathways was performed in 125 cases of the Wolff-Parkinson-White syndrome (type-A:54, type-B: 29, concealed: 42) complicated with drug-refractory and symptomatic atrioventricular reentrant tachycardia and/or paroxysmal atrial fibrillation. A total of 135 accessory pathways were identified: 50 left free-wall manifest, 34 left free-wall concealed, 21 right free-wall manifest, 2 right free-wall concealed, 15 posteroseptal manifest, 10 posteroseptal concealed, 2 right anteroseptal manifest and 1 right anteroseptal concealed. Accessory pathway conduction was successfully eliminated in 133 of these 135 accessory pathways (99%). Two right posteroseptal pathways were eventually ablated with direct current. Successful ablation required a mean 5.2 applications of radiofrequency current, a mean total energy of 2615 J and a mean fluoroscopic time of 52 min. The mean number of applications, applied energy and fluoroscopic time were greater in the right free-wall pathways than in the left free-wall pathways, and in the concealed pathways than in the manifest pathways. None of the procedures produced complications. During a mean follow-up period of 11.5 months, 1 right free-wall accessory pathway recurred and was ablated successfully in a repeat session. These results suggest that radiofrequency catheter ablation of accessory pathways is highly effective and safe irrespective of the accessory pathway location and properties, although these factors can affect the difficulty of this procedure. This technique may be an alternative to surgical therapy for Wolff-Parkinson-White syndrome with drug-refractory and symptomatic supraventricular tachyarrhythmias.

Lipofection of synthetic oligodeoxyribonucleotide having a palindromic sequence of AACGTT to murine splenocytes enhances interferon production and natural killer activity

A synthetic 22-mer oligodeoxyribonucleotide having an AACGTT palindrome, AAC-22, induced interferon (IFN) production and augmented the natural killer (NK) activity in murine splenocytes, whereas its analogue, ACC-22, having an ACCGGT palindrome, did not. The binding of AAC-22 to splenocytes was not different from that of ACC-22. Lipofection of AAC-22 to splenocytes remarkably enhanced IFN production and NK cell activity, whereas that of ACC-22 caused little enhancement. These results strongly suggest that the prerequisite for IFN production is not the binding of AAC-22 to the cell surface receptors, but its penetration into the spleen cells.

Effect of tyrphostin on cell growth and tyrosine kinase activity of epidermal growth factor receptor in human gliomas

The effects of tyrphostin, a selective protein tyrosine kinase inhibitor, on epidermal growth factor (EGF)-stimulated cell growth and EGF-receptor tyrosine kinase activity were studied in four human glioma cell lines. Stimulation by EGF induced variable enhancements of cell growth as well as tyrosine phosphorylation of EGF receptor and intracellular target proteins in all glioma cell lines. The level of immunoreactive EGF receptor detected with antibodies against extra- and intracellular domains was moderate in all four glioma cell lines, but markedly decreased with the latter antibody in two glioma cell lines. This variation was associated with considerable reduction of the EGF-stimulated tyrosine autophosphorylation level. Tyrphostin inhibited dose-dependently the EGF-stimulated cell growth and tyrosine autophosphorylation in all glioma cell lines, and the optimum time for the maximum inhibitory effect on tyrosine autophosphorylation was 12 to 18 hours after treatment with tyrphostin. The antiproliferative activity of tyrphostin nearly correlated quantitatively with its potency as an inhibitor of the EGF-stimulated EGF receptor tyrosine kinase activity. Tyrphostin had no significant effect on the immunoreactive EGF receptor levels, on the affinity constants and numbers of EGF receptor, or on the down-regulation and specific internalization of EGF receptor in any glioma cell line, suggesting that the effects of tyrphostin are not likely to be the results of reduction in EGF receptor and EGF binding capacity. In addition, the serum-stimulated cell growth was also inhibited dose-dependently by higher concentrations of tyrphostin in all glioma cell lines. It might be suggested, therefore, that tyrphostin inhibits EGF-stimulated cell growth by a specific suppression of EGF receptor tyrosine kinase activity, and at higher concentrations there appears to be some degree of either nonspecific inhibition or inhibition of serum-stimulated protein tyrosine kinase activity to induce the cell growth inhibition of gliomas.

Myristoylation of protein at a distinct position allows its phosphorylation by protein kinase C

A hydrophilic enzyme, lysozyme, was myristoylated in vitro by the N-hydroxysuccinimide ester of myristic acid and three monomyristoylated lysozymes modified at a distinct position (at Lys-13, Lys-33, Lys-97) were isolated by two-step column chromatography. The relationship between membrane binding and phosphorylation by protein kinase C of these monomyristoylated lysozymes were examined using phospholipid vesicles. These three lysozymes bound to phospholipid vesicles to the same extent, whereas the binding of nonmyristoylated native lysozyme was negligible. When native and three monomyristoylated lysozymes were reacted with protein kinase C in a phosphatidylserine (PS)-containing vesicle system, phosphorylation was observed with the myristoylated lysozymes, whereas that of native lysozyme was negligible. However, a remarkable (more than sixfold) difference in the extent of phosphorylation by protein kinase C was observed among three monomyristoylated lysozymes with a different myristoylated position. These results suggest that the membrane binding of substrate protein is not sufficient for the phosphorylation by protein kinase C and the topology of the substrate protein on the membrane play a crucial role in the recognition of substrate protein by protein kinase C. These results further indicate that protein myristoylation can modulate the topology of the membrane-bound protein.

Two cases of penile cancer: magnetic resonance imaging in the evaluation of tumor extension

Two patients with penile cancer were evaluated with magnetic resonance imaging (MRI) to determine tumor extent. Corporeal involvement was revealed in only 1 of the 2 cases, which was delineated on MRI and confirmed histologically. We conclude that MRI, especially the T1-weighted image, is helpful in determining treatment in cases of penile cancer.