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Nucleotide sequences from tryptophan messenger RNA of Escherichia coli: the sequence corresponding to the amino-terminal region of the first polypeptide specified by the operon.

Mutants with internal deletions that terminate near the operator end of the tryptophan operon of E. coli were used in studies on the nucleotide sequence at the 5' end of the messenger RNA transcribed on this operon. The findings obtained permitted identification of a sequence of 43 nucleotides corresponding to the aminoterminal 11 amino acids of anthranilate synthetase component I, the polypeptide specified by the operator-proximal structural gene of the operon. It was also shown that the translation initiation codon for this polypeptide is preceded on the messenger by a "leader" sequence of unknown function, at least 150 nucleotides in length.

Amino Acid Sequence↗

Presence of abscisic acid, a phytohormone, in the mammalian brain.

This paper reports the presence of abscisic acid, one of the most important phytohormones, in the central nervous system of pigs and rats. The identification of this hormone in brain was made after extensive purification by using a radioimmunoassay that is very specific for (+)-cis-abscisic acid. The final product of purification from mammalian brain has the same properties as authentic abscisic acid: it crossreacts in the radioimmunoassay for the phytohormone and it has the same retention properties and the same gas chromatography/mass spectrometry characteristics. Moreover, like (+)-cis-abscisic acid itself, the brain factor inhibits stomatal apertures of abaxial epidermis strips of Setcreasea purpurea Boom (Commelinaceae). The presence of abscisic acid conjugates that are present in plants has also been identified in brain.

Abscisic Acid↗

Initiation of RNA synthesis in vitro by vesicular stomatitis virus: single internal initiation in the presence of aurintricarboxylic acid and vanadyl ribonucleoside complexes.

In the presence of aurintricarboxylic acid (ATA) and vanadyl ribonucleoside complexes (VRC), we have isolated and characterized a small RNA, product of VSV in vitro transcription. This RNA is capped and lacks poly(A) at its 3'-end. Nucleotide sequence analysis revealed that this RNA corresponds to the 5'-terminal transcription product of the N-gene. The termination of the transcription occurs precisely at the 118th base from the 3'-end of the VSV genome. Analysis of the nucleotide sequence around this region reveals a potential secondary structure. Photoreaction of the VSV with 4'-substituted psoralen fails to inhibit the synthesis of the 68-mer RNA under conditions where full length mRNA synthesis is blocked, indicating that the psoralen binding site is located further into the N-gene. Since this RNA is the only in vitro transcription product synthesized under these conditions, the existence of two types of polymerase activities, one for the synthesis of leader RNA and one for mRNA, is suggested.

Animals↗

Nucleotide sequence analysis of alpha-amylase and thiol protease genes that are hormonally regulated in barley aleurone cells.

We have determined the nucleotide sequences of Amy32b, a type A alpha-amylase gene, and of the gene for aleurain, a thiol protease closely related to mammalian cathepsin H. Both are expressed in barley aleurone cells under control of the plant hormones gibberellic acid and abscisic acid, but only aleurain is expressed at high levels in other barley tissues. Sequence analysis indicates that the 5' end of the aleurain gene, comprising 3 exons and 2 introns, may have become associated with the remainder of the gene, encoding the protease domain of the protein, by some sort of recombination event. This 5' domain of the gene is very G + C-rich and is flanked by inverted repetitive sequences. We found two different groups of homologous sequence elements. The first group consists of four blocks of sequences conserved in the same spatial arrangement in both genes; these are arranged at similar intervals upstream from the Amy32b TATA box and from a TATA box present in intron 3 of aleurain, outside of the 5' domain and upstream from the protease domain. A part of two of these conserved sequences is similar to the core sequence of certain enhancer elements characterized from mammalian cells. The second group of homologous elements is present in the upstream region of both genes. We speculate that these conserved sets of sequences may have some role in either the tissue specificity of expression of the genes or in some part of the hormonal regulation imposed on them.

Abscisic Acid↗

Selective phosphodiesterase-4 inhibitors in chronic obstructive lung disease.

PURPOSE OF REVIEW: Chronic obstructive pulmonary disease (COPD) is a disease state characterized by airflow limitation that is usually progressive. In addition, an abnormal inflammatory response of the lungs to noxious particles or gases can be seen throughout the airways, parenchyma, and pulmonary vasculature. So far, anti-inflammatory medications (eg, inhaled corticosteroids) have failed to show a major effect on the decline of lung function in COPD patients. Novel anti-inflammatory therapies such as selective phosphodiesterase 4 (PDE4) inhibitors are in clinical development. Their potential role in the management of COPD is described in this review. RECENT FINDINGS: Some of the selective PDE4 inhibitors have demonstrated in vitro and in vivo anti-inflammatory activity on cells commonly linked to airway inflammation in COPD, such as neutrophils. While these agents seem to offer only a modest improvement in lung function compared with other bronchodilators, their anti-inflammatory effects appear to provide some substantial benefits in reducing exacerbations and improving health-related quality of life. SUMMARY: Based on the available data, the second generation of selective PDE4 inhibitors will likely provide additional therapeutic options for the management of COPD. These agents may become an important tool in the treatment of this disease, since they target three important components of COPD: airway obstruction, inflammation, and structural changes.

3',5'-Cyclic-AMP Phosphodiesterases↗

Synthesis of diastereoisomeric peptides incorporating cycloglutamic acids. Substrate specificity of vitamin K-dependent carboxylation.

Tripeptides Boc-X-Glu-Val where X is alpha-methyl glutamic acid or various cyclic analogues of glutamic acid, such as 1-amino-1,3-dicarboxycyclohexane (cis or trans-CHGA) or -cyclopentane (cis or trans-CPGA) have been synthesized. Methods for the selective protection, activation, and coupling of such unnatural amino acids are described. The peptides, which are potential competitive inhibitors of the vitamin K-dependent carboxylation, have been preliminarily tested with the rat liver microsomal carboxylase and found to be effective substrates of the carboxylation reaction.

Amino Acid Sequence↗

Release of previously incorporated gamma-[3H]aminobutyric acid in rabbit caudate nucleus slices.

The release of gamma-aminobutyric acid (GABA) was studied in slices of the head of the rabbit caudate nucleus. The slices were preincubated with [3H]GABA and then superfused. Aminooxyacetic acid was present throughout. Both the tritium in the slices and that in the superfusate consisted practically entirely of [3H]GABA. Stimulation for 2 min by electrical field pulses of 3 ms width and 9 V/cm voltage drop (36 mA current strength) at 5 or 20 Hz elicited an overflow of [3H]GABA that amounted to 0.23 or 0.47% of the tritium content of the tissue, respectively, and was diminished by 85% in the presence of tetrodotoxin. At higher current strength, less of the stimulation-evoked overflow was tetrodotoxin-sensitive. cis-1,3-Aminocyclohexane carboxylic acid diminished the uptake of [3H]GABA into the tissue but did not change the percentage released by electrical stimulation. Ca2+ withdrawal greatly accelerated basal [3H]GABA efflux and almost abolished the response to stimulation. Nipecotic acid 10-1,000 microM enhanced both the basal and (up to eightfold) the stimulation-evoked overflow. The method described allows us to elicit electrically a quasiphysiological, i.e., Ca2+-dependent and tetrodotoxin-sensitive, neuronal release of [3H]GABA. Nipecotic acid diverts released [3H]GABA from reuptake to overflow.

Amino Acids↗

Effects of omega-amino acids and related compounds on staphylococcal infections in mice: a combined prophylactic-therapeutic procedure.

By a short-term combined prophylactic-therapeutic procedure, the following compounds were found to be active against staphylococcal infections in Swiss mice: gamma-aminobutyric acid, gamma-amino-beta-hydroxybutyric acid (GABOB), delta-amino-valeric acid (DAVA), epsilon-aminocaproic acid (EACA), trans-4-aminomethylcyclohexanecarboxylic acid (trans-AMCHA), taurine, and cysteic acid. Many of these compounds had displayed limited or no activity by a previously used prophylactic procedure. Although DAVA and GABOB were the most potent of the straight-chain omega-amino acids, trans-AMCHA displayed the greatest antistaphylococcic activity of the omega-amino acids thus far investigated. Homocarnosine (gamma-aminobutyrl histidine, which also was active by the prophylactic procedure) equalled trans-AMCHA in activity. Taurine was similar in potency to DAVA, and the activity of cysteic acid approximated that of EACA.

Alanine↗

An important role for endogenous synthesis of arginine in maintaining arginine homeostasis in neonatal pigs.

This study was designed to test the hypothesis that endogenous arginine synthesis plays an important role in maintaining arginine homeostasis in neonatal pigs. Gabaculine was used as a suicide inhibitor of ornithine aminotransferase to decrease the intestinal conversion of glutamine-derived pyrroline-5-carboxylate (P-5-C) into ornithine, the precursor of both citrulline and arginine. Four-day-old suckling pigs received oral administration of 0.0 or 0.83 mg gabaculine/kg body wt every 4 h during a 12-h period from 6 A.M. to 6 P.M. Blood was collected from piglet's jugular vein at 6 A.M. and 6 P.M. after a 2-h isolation from sows. Gabaculine treatment decreased plasma concentrations of ornithine, citrulline, and arginine by 59, 52, and 76%, respectively, and increased those of glutamine and proline by 74 and 220%, respectively. The gabaculine treatment also increased plasma concentrations of leucine, taurine, and ammonia by 29, 42, and 20%, respectively. There were no differences in intramuscular concentrations of amino acids between control and gabaculine-treated pigs. Because P-5-C synthase (the enzyme required for synthesis of P-5-C from glutamate) was almost exclusively located in enterocytes of 4-day-old pigs, our data suggest that the intestinal production of citrulline plays an important role in endogenous synthesis of arginine and its homeostasis in neonatal pigs.

Administration, Oral↗

Antiinflammatory effects of the phosphodiesterase-4 inhibitor cilomilast (Ariflo) in chronic obstructive pulmonary disease.

Cilomilast (Ariflo), a new oral phosphodiesterase-4 selective inhibitor, improves lung function in chronic obstructive pulmonary disease (COPD). We have evaluated its antiinflammatory effects in 59 patients with COPD randomized to receive cilomilast, 15 mg two times a day, or placebo for 12 weeks. Induced sputum differential cell counts were obtained at baseline and at five further visits. Interleukin-8 and neutrophil elastase were measured in sputum supernatant. Bronchial biopsies obtained at baseline and at Week 10 were immunostained and counted for neutrophils, CD8+ and CD4+ T-lymphocyte subsets, and CD68+ macrophages. Cells expressing the genes for interleukin-8 and tumor necrosis factor-alpha were identified by in situ hybridization and quantified. Compared with placebo, analysis of variance (ANOVA) of the change from baseline showed that cilomilast did not alter any sputum endpoint or FEV1. However, bronchial biopsies demonstrated that cilomilast treatment was associated with reductions in CD8+ (p = 0.001; ANOVA) and CD68+ cells (p < 0.05; ANOVA). In addition, by Poisson analysis, comparison of cell counts analyzed as a ratio of active to placebo demonstrated reductions of CD8+ (48% p < 0.01) and CD68+ (47% p = 0.001) cells. This is the first demonstration of reduction by any agent of airway tissue inflammatory cells characteristic of COPD. Phosphodiesterase-4 inhibitors represent a promising new class of substances for use in antiinflammatory treatment of this disease.

3',5'-Cyclic-AMP Phosphodiesterases↗

An overview of the pharmacokinetics of cilomilast (Ariflo), a new, orally active phosphodiesterase 4 inhibitor, in healthy young and elderly volunteers.

The oral pharmacokinetics of cilomilast (Ariflo) were investigated in five separate studies in healthy volunteers. Cilomilast was rapidly absorbed, and pharmacokinetics were dose proportional after single and repeat dosing. The elimination half-life was 7 to 8 hours; accordingly, steady state was reached on the 3rd day of dosing. The degree of accumulation following repeat twice-daily dosing was predictable from the data following a single dose. Although systemic exposure (AUC) was, on average, 21% higher in elderly (65-84 years) compared with young subjects, values for Cmax and t(1/2) were similar, and no difference in tolerability was noted. Single and repeat doses of cilomilast up to and including 15 mg (dosed before or taken between meals) were well tolerated. Dosing with food reduced the rate of absorption without affecting total bioavailability. Hence, tolerability was optimal in the fed state; repeat doses up to and including 30 mg twice daily aftermeals were well tolerated following dose titration.

3',5'-Cyclic-AMP Phosphodiesterases↗

A trypsin inhibitor trans-4-guanidinomethylcyclohexanecarboxylic acid 4-tert-butylphenyl ester suppresses the onset of DNA synthesis in Escherichia coli cells synchronized by phosphate starvation.

trans-4-Guanidinomethylcyclohexanecarboxylic acid 4-tert-butylphenyl ester (GMCHA-OPh'Bu), a trypsin inhibitor, dose-dependently inhibited the growth of Escherichia coli K-12 IAM1264. Growth inhibition was preceded by dose- and time-dependent inhibition of DNA synthesis. These results strongly suggested participation of a trypsin-like proteinase in DNA synthesis. To clarify this suggestion, the effects of GMCHA-OPh'Bu on the doubling time and on the uptake of [methyl-3H]thymidine into DNA were examined with E. coli K-12 IAM1264 synchronized by a modified version of phosphate starvation. The synchrony lasted for two or three cycles with a doubling time of 55 min and a cell division period of 15 min. The cell cycle of E. coli was divided into three periods, cell division period (P), the period between cell division and initiation of chromosome replication (Q) and the period between initiation of chromosome replication and cell division (R). The R period was subdivided into two periods, R1 in which the rate of thymidine uptake into DNA was increasing, and R2 in which it was constant. The addition of GMCHA-OPh'Bu at the R1 period did not affect the already-initiated round of cell division, however, it retarded the next round. The addition at P, Q or R2 retarded the cell division in the same round, causing prolongation of the R1 period. A sharp and momentary appearance of trypsin-like proteinase activity peaked at the Q/R1 boundary in one cell cycle, and inhibition of the activity prolonged the R1 period.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗

Cilomilast: orally active selective phosphodiesterase-4 inhibitor for treatment of chronic obstructive pulmonary disease.

OBJECTIVE: To review available literature evaluating the pharmacology, pharmacokinetics, clinical efficacy, and adverse effects of cilomilast, a selective phosphodiesterase-4 (PDE4) inhibitor. DATA SOURCES: Literature was accessed through MEDLINE (1966-May 2006), Current Contents Clinical Medicine (1998-May 2006), and The Cochrane Library Database (1st quarter 2006) using the terms cilomilast, Ariflo, and SB 207 499. Reference lists from retrieved articles and information from the manufacturer were manually reviewed. STUDY SELECTION AND DATA EXTRACTION: All clinical trials evaluating cilomilast and published in English were included in this review. In addition, articles evaluating the pharmacology, pharmacokinetics, and safety of cilomilast in humans were reviewed. DATA SYNTHESIS: Cilomilast is a second-generation PDE4 inhibitor with antiinflammatory effects that target bronchoconstriction, mucus hypersecretion, and airway remodeling associated with chronic obstructive pulmonary disease (COPD). Selective PDE4 inhibition is proposed to maximize the antiinflammatory effects of PDE inhibition while minimizing the adverse effects of nonselective agents. To date, 4 clinical trials have evaluated the efficacy of cilomilast and demonstrated improvement in lung function (forced expiratory volume in 1 second) and quality of life and reduction in the occurrence of COPD exacerbations compared with placebo. Cilomilast is generally well tolerated, with adverse effects being overall mild and self-limiting. CONCLUSIONS: COPD is a progressive disease, and available treatment options provide limited efficacy. Given its unique mechanism of action and improved adverse effect profile compared with previous agents, cilomilast may have a promising role for the management of COPD.

3',5'-Cyclic-AMP Phosphodiesterases↗

Cilomilast for COPD: results of a 6-month, placebo-controlled study of a potent, selective inhibitor of phosphodiesterase 4.

BACKGROUND: COPD is a relentless, progressive disease. This study evaluated the efficacy of cilomilast, a selective phosphodiesterase (PDE) 4 inhibitor, in the treatment of COPD. METHODS: This was a randomized, double-blind, placebo-controlled, parallel-group, multicenter study in subjects with COPD. After a 4-week, single-blind, placebo run-in period, eligible subjects were randomized in a 2:1 ratio to receive oral cilomilast, 15 mg bid, or placebo for 24 weeks. Subjects between 40 and 80 years of age who had received a diagnosis of COPD were eligible for the study. The primary efficacy variables were changes from baseline in trough (ie, predose) FEV1 and in total score of the St. George's Respiratory Questionnaire (SGRQ). A key secondary end point was the incidence rate of COPD exacerbations. RESULTS: The average change from baseline in FEV1 over 24 weeks in the cilomilast group was an increase of 10 mL compared with a decrease of 30 mL in the placebo group (difference, 40 mL; p = 0.002). When averaged over 24 weeks, there was a clinically significant reduction in the mean total SGRQ score in subjects receiving cilomilast therapy, with a difference of 4.1 U compared with subjects who received placebo (p = 0.001). A greater percentage of subjects in the cilomilast group were exacerbation-free at 24 weeks (74%; p = 0.008) compared with placebo (62%). Adverse events were generally mild or moderate and were not unexpected for this class of medications. GI adverse events that interfered with daily activities (cilomilast, 17%; placebo, 8%) predominantly occurred within the first 3 weeks of initiating cilomilast therapy. CONCLUSION: Cilomilast is an orally active, potent, and selective inhibitor of PDE-4. Cilomilast maintained pulmonary function and improved health status, and reduced the rate of COPD exacerbations during 24 weeks of treatment. This study supports the use of cilomilast, a novel, selective PDE-4 inhibitor, in subjects with COPD.

3',5'-Cyclic-AMP Phosphodiesterases↗

Bioavailability of the oral selective phosphodiesterase 4 inhibitor cilomilast.

STUDY OBJECTIVE: To determine the absolute bioavailability of cilomilast, and assess the effects of food, dosing time, and coadministration of antacid agents on its bioavailability and pharmacokinetics in healthy volunteers. SETTING: Clinical pharmacology unit. DESIGN: Five prospective pharmacokinetic studies: one single-blind, dose-escalating, placebo-controlled trial; four open-label, randomized studies. SUBJECTS: Ninety-six healthy adult volunteers who were nonsmokers. INTERVENTION: In the first study, four subjects received intravenous cilomilast 1, 2, and 4 mg. In the second study, 16 subjects received oral cilomilast 15 mg or intravenous cilomilast 4 mg. In the other three studies, a total of 76 subjects were given single oral 15-mg doses; one study compared its effects in fed versus fasted subjects, one looked for differences of morning versus evening dosing, and one examined coadministration with aluminum hydroxide-magnesium hydroxide. MEASUREMENTS AND MAIN RESULTS: After intravenous administration of cilomilast, plasma concentrations increased in an approximately dose-proportional manner; the half-life, approximately 6.5 hours, was dose independent. Cilomilast clearance and volume of distribution were small. After oral dosing, the absolute bioavailability was consistently close to 100%. Absorption was slower in fed subjects than in fasted (median 2-hr delay in time to reach maximum plasma concentration, average 39% reduction in maximum plasma concentration), but the area under the concentration-time curve from time zero to infinity (systemic availability) was unaffected. Pharmacokinetic parameters were not influenced by time of dosing or coadministration of antacid. CONCLUSION: The absolute bioavailability of oral cilomilast was 100%; it was not adversely affected by time of dosing or coadministration with food or antacid.

3',5'-Cyclic-AMP Phosphodiesterases↗