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At least 19 recordsLinked to original sources

PubMed1992

Localization of alg, opr, phn, pho, 4.5S RNA, 6S RNA, tox, trp, and xcp genes, rrn operons, and the chromosomal origin on the physical genome map of Pseudomonas aeruginosa PAO.

The genes encoding the rrn operons, the 4.5S and 6S RNAs, elements of protein secretion, and outer membrane proteins F and I, and regulatory as well as structural genes for exotoxin A, alkaline phosphatase, and alginate and tryptophan biosynthesis, were assigned on the SpeI/DpnI macrorestriction map of the Pseudomonas aeruginosa PAO chromosome. The zero point of the map was relocated to the chromosomal origin of replication.

Chromosome Mapping↗

PubMed1987

Common mechanism controlling phase and antigenic variation in pathogenic neisseriae.

The expression of the Neisseria gonorrhoeae opacity protein (Op, protein II), a major antigenic determinant of the outer membrane, is subject to frequent phase transitions. At least nine expression loci (opaE) are involved in the production of a large number of serologically distinct Op types. Using opa-specific oligonucleotides as probes in genomic blots, we detect Op-related gene sequences (opr) in N. meningitidis as well as in N. lactamica. DNA sequence analysis of such opr genes derived from N. meningitidis reveals distinct regions of homology with gonococcal opa E genes. As shown in the immunoblot, the proteins encoded by opa and opr are serologically related. Like the opaE genes, the 5'-coding sequences of the opr genes include a repetitive sequence composed of pentameric CTCTT units. The number of these coding repeat (CR) units is variable. This finding, together with the observation that all opr genes are constitutively transcribed, regardless of the status of protein production, suggests a translational control mechanism identical to that of the opa genes in gonococci. The related structures and control mechanisms of opa and opr genes imply a general significance of their gene products for the pathogenic character of the investigated Neisseria species.

Amino Acid Sequence↗

PubMed1975

The beta-adrenoceptors of the lung mediating inhibition of antigen-induced histamine release.

The beta-adrenoceptor stimulants, isoprenaline (IPR), orciprenaline (OPR), terbutaline (TRB), and ITP were studied for effects on antigen-induced release of histamine from guinea-pig lung tissue and for effects on guinea-pig isolated trachea and heart. The order of potency for the agents in the four funct-ons studied were: (a) inhibition of histamine release, IPR greater than OPR approximately equal to TRB greater than ITP equal 0; (b) heart stimulation, chronotropic effect, IPR greater than OPR greater than ITP approximately equal to TRB; (c) heart stimulation, inotropic effect, IPR greater than OPR greater than ITP greater than TRB; (d) trachea relaxation: IPR greater than TRB greater than OPR greater than ITP. These findings suggest that the beta-adrenoceptors mediating inhibition of antigen-induced release of histamine are more related to those mediating trachea relaxation (beta2) than those mediating cardiac stimulation (beta1).

Adrenergic beta-Agonists↗

PubMedDate not supplied

Support of cardiac performance following heart valve surgery by raising heart rate to the optimal pacing rate.

Effects of hemodynamic parameters of heart rate were studied in 19 patients with low cardiac output syndrome following open heart surgery for mitral and/or aortic valve replacement in the first five postoperative days. The central venous pressure (CVP), left atrial mean pressure (LAMP), and arterial blood pressures were determined at spontaneous heart rate (SHR), and during graded atrial (12 pts.) or ventricular (7 pts.) pacing each day. An "optimal pacing rate" (OPR), characterized by the most advantageous arterial pressures at the possible lowest levels of CVP and LAMP, and by the suppression of preexisting arrhythmias, if any, was established daily for maintaining each patient on that rate. The SHR was 69 +/- 9 and the OPR was 102 +/- 9 on the first postoperative day. For the fifth postoperative day the SHR was 68 +/- 10 and the OPR decreased to 90 +/- 9. Pacing with the OPR significantly increased cardiac performance. E.g. the hemodynamic improvement on the first postoperative day induced by pacing was comparable to the spontaneous improvement seen during the first five postoperative days. The hemodynamic effect of atrial pacing on circulation was more definitive than that of ventricular pacing. Since OPR may be significantly higher than SHR and varies from day to day, we suggest that, in cases where pacing is applied to improve cardiac performance, it be determined for each patient individually each postoperative day.

Adolescent↗

PubMed1989

Solubilization and purification of opioid receptor molecules of rat brain.

A P2 membrane preparation of rat brain (without cerebellum) was solubilized with CHAPS in Tris containing DTT and trypsin inhibitor. Two opiate ligands, 10b and 10cd, prepared by Liu et al, were employed consecutively in affinity chromatography, from which OPR's were eluted with Nx. The eluate was subsequently passed through a WGA affinity column and the OPR's eluted with N-GluNAc. This eluate was further purified and concentrated by preparative granular gel isoelectric focusing on SG200. Two protein peaks appeared separately at pH 5 and 7.8. The eluates from both peaks were examined for protein contents using the silver staining method, and binding activity was measured by RRA with 3H-etor. The results revealed that both samples contained active OPR purified to over 80,000 fold. The Mr was estimated by gel filtration to be 52 kD and 42 kD for OPR in the pH 5 and pH 7.8 samples respectively. OPR in the pH 5 sample have been determined to be of mu-type by their binding activity with 3H-ohm.

Animals↗

PubMed1989

[Solubilization and purification of opioid receptor molecules of rat brain].

P2 membrane preparation of rat brain (without cerebellum) was solubilized with CHAPS in Tris containing DTT and trypsin inhibitor. Two opiate ligands, 10b and 10cd, prepared by Liu et al, were applied consecutively in affinity chromatography, from which OPRs were eluted with Nx. The eluate was subsequently passed through a WGA affinity column and the OPR eluted with N-GluNAc. This eluate was further purified and concentrated by preparative granular gel isoelectric focusing on SG200. Two protein peaks appeared separately at pH 5 and pH7.8. The eluates from both peaks were analyzed for protein content by using silver staining method and binding activity was measured by RRA with 3H-etor. The results revealed that both samples contained active OPR purified to over 80,000 fold. The Mr was estimated by gel filtration to be 52 and 42 kD for OPR in the pH 5 and pH 7.8 samples respectively. The OPR in pH 5 sample has been characterized to be of mu-type, by its binding activity with 3H-ohm.

Animals↗

PubMed1988

Syncatalytic inactivation of prolyl 4-hydroxylase by synthetic peptides containing the unphysiologic amino acid 5-oxaproline.

Peptides containing the unphysiological amino acid 5-oxaproline (Opr) in the sequence R1-Xaa-Opr-Gly-OR2 were found to inactivate prolyl 4-hydroxylase from chick and human origins. Of the substances investigated, compounds with aromatic substituents R1 and R2 were particularly effective when compared with those with an aliphatic group or without a C-terminal blocking group. Both affinity of the individual peptides for the enzyme and partition ratio contributed to the differences in efficiency. Benzylcarbonyl-Phe-Opr-Gly-benzyl ester was the most effective substance tested, its concentration giving 50% inactivation in 1 h being 0.8 microM. Inactivation was only observed in the presence of 2-oxoglutarate and Fe2+. The Opr peptides enhanced the decarboxylation of 2-oxoglutarate by prolyl 4-hydroxylase, the Vmax values obtained with the individual peptides being positively correlated with their inactivating efficiency. Inactivation was prevented by high concentrations of peptide substrate and ascorbate. Lineweaver-Burk kinetics experiments suggested noncompetitive inhibition with respect to peptide substrate and ascorbate. Lysyl hydroxylase was not affected by Opr peptides in concentrations of up to 1.5 mM in either the presence or absence of prolyl 4-hydroxylase. The results suggest that the oxaproline compounds are specific syncatalytic inactivators of prolyl 4-hydroxylase.

Animals↗

PubMed1991

Sex pheromone perception in male pine sawflies, Neodiprion sertifer (Hymenoptera; Diprionidae).

Electroantennographic and single sensillum recordings were performed on male pine sawfly, Neodiprion sertifer, antennae. Responses to the sex pheromone component (2S, 3S, 7S)- 3,7-dimethyl-2-pentadecenyl (diprionyl) acetate (SSS:OAc), to the behavioral inhibitor (2S, 3R, 7R)-diprionyl acetate (SRR:OAc), to the six other enantiomers of diprionyl acetate, and to the biosynthetic precursor diprionol were recorded. Responses to trans-perillenal, a monoterpene identified in female gland extracts and to (2S, 3S, 7S)-diprionyl propionate (SSS:OPr), a field attractant for N. sertifer and some related sawfly species were also recorded. EAG recordings demonstrated a high antennal sensitivity to SSS:OAc and to SSS:OPr. A somewhat lower response was elicited by SRR:OAc. Single sensillum recordings revealed 8-12 different cells firing in each sensillum, corresponding to the number of cells observed in earlier morphological investigations. Out of these cells all, except one, responded to SSS:OAc and to SSS:OPr. No differences in the response to the two components could be observed. The largest amplitude cell in each sensillum was specifically tuned to the behavioral antagonist, SRR:OAc. The pheromone perception system encountered in male pine sawflies thus differs clearly from that observed in moths.

Adaptation, Physiological↗

PubMed1975

Psychological characteristics of deep submergence vehicle personnel.

The personality and developmental characteristics of U.S. Navy Deep Submergence Vehicle (DSV) personnel, including operators and crews, were documented and compared to the characteristics of U.S. Navy divers. The results show that DSV operators (DSV Oprs) had a significantly less asocial developmental pattern than divers, while developmental experiences of DSV crews (DSV Crs) were similar to those of divers. Personality measures (EPPS) indicate that both DSV Oprs and DSV Crs are presently more sociable as adults than divers and would probably be more effective in situations involving small group interaction. The modifications which have occurred in the behavior of DSV Crs may be related to experience in the highly interpersonal DSV situation. The findings also show that DSV Oprs prefer to take fewer risks than divers, while the DSV Crs are more like divers in risk-taking behavior. The implications of this research to DSV mission effectiveness are discussed.

Adult↗

PubMed1990

Specific inactivation of prolyl 4-hydroxylase and inhibition of collagen synthesis by oxaproline-containing peptides in cultured human skin fibroblasts.

The crucial role of collagen in fibrotic disorders has prompted attempts to develop drugs that inhibit collagen accumulation. Peptides containing the unphysiological amino acid 5-oxaproline (Opr) have recently been found to act as specific syncatalytic inactivators of pure prolyl 4-hydroxylase, the enzyme that catalyzes the formation of 4-hydroxyproline in collagens. The present study indicates that oxaproline-containing peptides benzyloxycarbonyl-Phe-Opr-Gly-benzyl ester (I) and benzyloxycarbonyl-Phe-Opr-Gly-ethyl ester (II) inactivate prolyl 4-hydroxylase in cultured human skin fibroblasts, peptide I being about twice as potent as peptide II. Inactivation by 50% was observed after culturing with about 20-40 microM concentrations of peptide I for 48 h. The inactivation appears to be specific, as no changes were found in the activities of two other intracellular enzymes of collagen synthesis, lysyl hydroxylase and galactosylhydroxylysyl glucosyltransferase. Synthesis of 4-hydroxyproline by the cells was markedly decreased, and 4-hydroxyproline-deficient procollagen accumulated intracellularly, whereas no changes were found in the incorporation of [14C]leucine into protein after culturing of the cells with a 30 microM concentration of peptide I for 48 h. No changes were seen in the viability of the cells or the release of lactate dehydrogenase from them into the culture medium. No significant changes were found in the steady-state levels of the mRNAs for the pro-alpha 1 chains of type I and type III procollagens or for the alpha and beta subunits of prolyl 4-hyroxylase or fibronectin after culturing with 75 microM peptide I for 48 h. The data indicate that inactivation of cellular prolyl 4-hydroxylase has marked effects on cellular 4-hydroxyproline formation and collagen secretion but no effects on the steady-state levels of mRNAs for type I and III procollagens or the two types of subunit of prolyl 4-hydroxylase.

Cells, Cultured↗

PubMed1975

Multiplicity of oligopeptide transport systems in Escherichia coli.

The ability of Escherichia coli K-12 4212 to utilize a variety of oligopeptides as sources of required amino acids was examined. Triornithine-resistant mutants of this strain were oligopeptide permease deficient (Opp-) as judged by their inability to utilize (Lys)3 and (Lys)4 as sources of lysine and their resistance to the toxic tripeptide (Val)3. These same mutants were able to grow when Met-Met-Met, Met-Gly-Met, Met-Gly-Gly, Gly-Met-Gly, Gly-Gly-Met, Gly-Met-Met, Met-Met-Gly, or Leu-Leu-Leu were supplied in place of the requisite amino acid. The system mediating the uptake of these peptides, herein designated Opr I, was not able to transport N-alpha-acetylated peptides, nor the tetrapeptides Met-Gly-Met-Met, Met-Met-Gly-Met, or Met-Met-Met-Gly. Competition experiments indicated that trimethionine and trileucine enter E. coli K-12 via either Opp or Opr I. Analogous results were found using the methionine, leucine-requiring auxotroph E. coli B163. It appears that more than one oligopeptide transport system exists in E. coli and that the system mediating peptide uptake is complex.

Biological Transport, Active↗

PubMed1989

Hormonal control of the cervix in pregnant gilts. II. Relaxin promotes changes in the physical properties of the cervix in ovariectomized hormone-treated pregnant gilts.

The effects of relaxin on the physical properties of both the uterine and vaginal portions of the cervix were studied between days 80 and 110 of pregnancy in ovariectomized gilts given progesterone to maintain pregnancy. In controls gilts the extensibility, lumen diameter, and wet weight of the uterine portion of the cervix were less than those of the vaginal portion of the cervix on day 80, but increased thereafter, and by day 110 did not differ (extensibility and wet weight) or approached (lumen diameter) those values of the vaginal portion of the cervix. When gilts were ovariectomized on either days 80 or 100 and given progesterone only (groups OP-100 and OP-110) extensibility, lumen diameter, and wet weight failed to increase in both the uterine and vaginal portions of the cervix. After replacement therapy with progesterone plus relaxin (groups OPR-100 and OPR-110), extensibility, lumen diameter, and wet weight increased to values as least as large as those in control groups in both portions of the cervix. In all groups the uterine portion of the cervix changed more dramatically than the vaginal portion. After hormone replacement therapy, blood levels of relaxin were moderately higher, and blood levels of progesterone were somewhat lower than those in control gilts. There was little or no difference in estrogen levels between ovariectomized and control gilts. We conclude that relaxin plays an important role in promoting increased growth and extensibility in both the uterine and vaginal portions of the cervix after day 80 of gestation in the gilt.

Animals↗

PubMedDate not supplied

[Olfactory dysfunction: its diagnosis and surgical treatment].

This paper discusses the results of diagnosis and surgical therapy of olfactory dysfunction. It describes a method of qualitative and quantitative olfactometry which involves olfactory investigation by means of an olfactory unit and an olfactometer based on the smelling principle. The olfactory unit and olfactometer permit qualitative and quantitative olfactory measurements. Objective olfactometry was performed in 34 patients using the galvanic skin reflex, olfactory-pupillary reflex (OPR), pneumography, and ECG. The method, developed by the present author for recording pupils responses by means of an optic pupillometer, allows differentiation of olfactory and trigeminal sensitivity during OPR examination. Objective olfactometry demonstrated that olfactory investigation with the aid of a custom built olfactometer gives reliable data. The procedure of endonasal operation of concha nasalis media in the olfactory fissure area in the case of hypertropic rhinitis accompanied by olfactory dysfunction is described.

Humans↗

PubMed2026

Establishment of a CRISPR-Cas9 Library for Indica Rice and Identification of OsOPR5 (LOC_Os06g11210) as a Regulator of Root Architecture.

Functional characterization of a large number of rice genes remains a major challenge despite the availability of genome sequences and large-scale transcriptomic datasets. CRISPR-Cas9 library is a powerful approach for high-throughput targeted mutagenesis; however, its application in indica rice cultivars remains limited due to low transformation and regeneration efficiencies. In this study, we developed a CRISPR-Cas9 library targeting 12,000 rice genes and evaluated its utility for functional genomics in the indica cultivar MTU-1010. Sanger sequencing and NGS analysis of the plasmid library revealed high sgRNA coverage and more than 80% accuracy. Transformation of the developed library into the indica cultivar MTU-1010 resulted in a high target editing efficiency, with 90% of analyzed transgenic plants carrying mutations at the intended target site. Functional analysis of one homozygous mutant identified a previously uncharacterized role for OsOPR5 (LOC_Os06g11210), a member of the 12-oxophytodienoate reductase family in root architecture. The opr5 mutants exhibited significant reductions in lateral root number, seminal and crown root number, and root length, demonstrating that OsOPR5 positively regulates root system architecture in rice. Notably, endogenous jasmonic acid (JA) and JA-isoleucine levels were not significantly altered in the mutant, suggesting potential functional specialization or redundancy among rice OPR family members for JA accumulation. The root system architecture is a key determinant of water and nutrient acquisition; our results suggest that OsOPR5 may play an important role in adaptation under adverse environmental conditions. Collectively, this study establishes an efficient genome-editing platform for indica rice and identifies OsOPR5 as a novel regulator of root development.

Oryza↗

PubMedDate not supplied

The protective effect of desferal on rat myocardial mitochondria is not prolonged after withdrawal of desferal.

Reperfusion of ischaemic myocardium is necessary to sustain tissue viability (without it the tissue becomes necrotic), but reperfusion, on the other hand, can damage cells which have survived ischaemia. There is now considerable evidence that oxygen radicals, especially hydroxyl radicals produced via the Haber-Weiss and Fenton reactions, are responsible for reperfusion damage. Various investigators have reported that desferal, an iron chelator, has a beneficial effect on the myocardium during ischaemia and reperfusion. The aim of this study was two-fold: i) whether superoxide anions in the absence of LMWI can impair mitochondrial function, and ii) whether the protective effect of desferal on the mitochondrial function persists after withdrawal of desferal. Experiments were done on isolated rat hearts subjected to normothermic ischaemic cardiac arrest (NICA), with or without desferal, followed by 15-min reperfusion with desferal, followed by 15-min perfusion without desferal, or a hypoxanthine/xanthine oxidase medium that generates superoxide anions (with or without desferrioxamine (desferal) in the perfusate). Mitochondrial function (QO2 (state 3), ADP/O and OPR) as well as LMWI were measured. Our results indicated that i) superoxide anions and/or hydrogen peroxide can, independently of LMWI, damage the mitochondria, and ii) withdrawal of desferal after the respiratory burst resulted in the same or more severe mitochondrial damage than without any desferal.

Adenosine Diphosphate↗

PubMed1987

The active analog approach applied to the pharmacophore identification of benzodiazepine receptor ligands.

Applied to seven potent benzodiazepine-receptor ligands belonging to chemically different classes, the active analog approach allowed the stepwise identification of the pharmacophoric pattern associated with the recognition by the benzodiazepine receptor. A unique pharmacophore model was derived which involves six critical zones: (a) a pi-electron rich aromatic (PAR) zone; (b) two electron-rich zones delta 1 and delta 2 placed at 5.0 and 4.5 A respectively from the reference centroid in the PAR zone; (c) a freely rotating aromatic ring (FRA) region; (d) an out-of-plane region (OPR), strongly associated with agonist properties; and (e) an additional hydrophobic region (AHR). The model accommodates all presently known ligands of the benzodiazepine receptor, identifies sensitivity to steric hindrance close to the delta 1 zone, accounts for R and S differential affinities and distinguishes requirements for agonist versus non-agonist activity profiles.

Carbolines↗

PubMed1991

Evaluation of protective mAbs against Pseudomonas aeruginosa outer membrane protein I by C1q binding assay.

Seven monoclonal antibodies (mAbs) against the outer membrane proteins (OPRs) F, H and I of Pseudomonas aeruginosa were prepared. Western blot analysis has shown the mAbs to cross-react with all 17 serotypes of P. aeruginosa according to the International Antigenic Typing Scheme. Two of the mAbs (2A1, 6A4) protected mice against fatal P. aeruginosa pneumonia. The protective potential of the mAbs did not correlate with the immunoglobulin isotype nor with the fine antigen specificity and the in vitro bactericidal activity of the mAbs. Only the binding of the first complement component C1q of the mAbs as estimated in vitro by an ELISA was significantly correlated with their protective potential.

Animals↗

PubMed1990

Outer membrane proteins of Pseudomonas.

In this review, we describe the outer membrane proteins of Pseudomonas aeruginosa and related strains from the Pseudomonas fluorescens rRNA homology group of the Pseudomonadaceae, with emphasis on the physiological function and biochemical characteristics of these proteins. The use of opr (for outer membrane protein) is proposed as the genetic designation for the P. aeruginosa outer membrane proteins and letters are assigned, in conjunction with this designation, to known outer membrane proteins. Proteins whose primary functions involve pore formation, transport of specific substrates, cell structure determination and membrane stabilization are discussed. The conservation of selected proteins in the above Pseudomonas species is also examined.

Bacterial Outer Membrane Proteins↗