Two series of compounds, N-[(arylmethoxy)phenyl] sulfonamides and N-[(arylmethoxy)naphthyl] sulfonamides, were prepared as leukotriene D4 (LTD4) antagonists. In the phenyl series, N-[3-(2-quinolinylmethoxy)phenyl]-trifluoromethanesulfonamide (Wy-48,252, 16) was the most potent inhibitor of LTD4-induced bronchoconstriction in the guinea pig. With an intragastric ID50 of 0.
View Article and Find Full Text PDFThe rate of adsorption of Caulobacter bacteriophage phi CbK to Caulobacter crescentus is dependent on the structural integrity of the flagellum. Cells lacking part or all of the flagellum because of either mutation or mechanical shear were defective in adsorption, and the extent of the defect in adsorption reflected the amount of flagellar structure missing. Maximal adsorption rates were also dependent on cellular motility and energy metabolism, since adsorption to cells with paralyzed flagella was slower than adsorption to motile cells and inhibition of cellular energy metabolism with azide also reduced adsorption rates, even for nonmotile cells.
View Article and Find Full Text PDFPleiotropic mutants of Alcaligenes eutrophus with the phenotype Hno- have been characterized previously. They are deficient in several diverse metabolic activities, including hydrogen oxidation, nitrate and urea assimilation, denitrification, and various substrate transport systems. Phenotypically similar mutants were identified among hydrogenase-deficient strains of Pseudomonas facilis.
View Article and Find Full Text PDFGalactose appears to be the physiological inducer of the chromosomal lac operon in Klebsiella aerogenes. Both lactose and galactose are poor inducers in strains having a functional galactose catabolism (gal) operon, but both are excellent inducers in gal mutants. Thus the slow growth of K.
View Article and Find Full Text PDFThe biometrical treatment of laboratory data may require the estimation of a regression line for the transformation of one set of measurements to another. The regression procedure introduced in part I (1) of our work does not always yield unbiased results in such situations, since its estimators are not scale invariant. In part III we present the parameter estimation of a general regression equation which is scale invariant and retains all properties of the method comparison procedure, in particular its robustness.
View Article and Find Full Text PDFMutants of Klebsiella aerogenes able to express the hutUH operon in the absence of positive effectors were isolated and characterized. These mutations improve the hutUH promoter (PUH) by changing the -10 region to match the consensus sequence more closely. These mutations also affect another, oppositely oriented promoter in this region, PC.
View Article and Find Full Text PDFA DNA fragment carrying genes encoding the conjugal transfer system of the broad host range plasmid RK2 was inserted into a plasmid carrying the chromosomal origin of replication (oriC) from Klebsiella pneumoniae. The resulting plasmid, pEON1, was readily transferred between gram-negative bacteria and carried two potential origins of replication: oriC and the replication origin from pBR322 (oriPBR). Although pEON1 could be transferred to Caulobacter crescentus, Pseudomonas putida, and Rhodobacter sphaeroides, pEON1 was not maintained in these strains.
View Article and Find Full Text PDFThe hut(P) region (i.e., the region responsible for regulation of hutUH expression) of the Klebsiella aerogenes histidine utilization (hut) operons contains a bidirectional promoter.
View Article and Find Full Text PDFAnomalous origin of the left coronary artery from the pulmonary artery is a rare but important cause of congestive heart failure in infancy and of sudden death at all ages. Diagnosis is often missed when based solely on physical examination and noninvasive methods. A 4 year old patient is presented in whom mitral regurgitation was noted by a referring physician and an anomalous left coronary artery was found by Doppler color flow mapping upon referral and verified at cardiac catheterization.
View Article and Find Full Text PDFBeitr Infusionther Klin Ernahr
July 1988
Two series of phenylephrine derivatives were prepared and tested as inhibitors of leukotriene D4 (LTD4) induced and ovalbumin-induced bronchospasm in the guinea pig. The most potent compound of the urea series, (R)-N,N-diethyl-N-[2-hydroxy-2-[3-(2-quinolinylmethoxy)phenyl]ethyl]-N- methylurea (3, Wy-47,120), was orally active with ED50's of 56 mg/kg vs. LTD4 and 55 mg/kg vs.
View Article and Find Full Text PDFNet phospholipid synthesis is discontinuous during the Caulobacter crescentus cell cycle with synthesis restricted to two discrete periods. The first period of net phospholipid synthesis begins in the swarmer cell shortly after cell division and ends at about the time when DNA replication initiates. The second period of phospholipid synthesis begins at a time when DNA replication is about two-thirds complete and ends at about the same time that DNA replication terminates.
View Article and Find Full Text PDFThe daily activity rhythm of adult and senescent male rats of two different strains (Iva:SDIV and Emd:Wi-AF/Han) was evaluated over several days with a capacitance-induction motility monitor. The Iva:SDIV rats were 6 to 9 or 29 to 32 months old and the Emd:Wi-AF/Han rats were 3 to 5, 16 to 18, or 31 to 39 months old at the time of testing. The rats were maintained in individual cages under a 12:12 hr light/dark regimen prior to and during this experiment.
View Article and Find Full Text PDFMale rats aged 6, 19, or 33 months were trained successively in one- and two-way avoidance tasks. The one-way avoidance test consisted of up to 30 trials given in a single session with the conditional stimulus (CS; 14-kHz tone) presented for either 3 s or for 10 s in separate groups. Senescent rats performed poorest, middle-aged rats intermediately, and young adult rats best.
View Article and Find Full Text PDFIn a randomized, double-blind parallel group study the 24-hour hypotensive effect of piretanide and its influence on biochemical variables were compared with those of placebo in patients with mild to moderate essential hypertension. Sixty patients entered the study, all of whom met the inclusion criteria (RRdiast between 95 and 120 mmHg). There was no drop-out during the study, so that the results of all 60 patients were statistically analysed.
View Article and Find Full Text PDFA recombination-deficient (Rec-) strain of Caulobacter crescentus has been isolated from a collection of mutants sensitive to ultraviolet irradiation. The Rec- mutant fails to give recombinants following phi Cr30-mediated generalized transduction or following RP4-mediated conjugation. The recombination frequency in the Rec- strain is at least 5000-fold lower than in the wild type strains.
View Article and Find Full Text PDFIn an effort to determine the role that metabolism by the cytochrome P-450 system plays in the development of hexachlorobenzene (HCB)-induced porphyria, Japanese quail were pretreated with either beta-naphthoflavone (BNF) or phenobarbital (PB) and then treated with HCB. PB or BNF pretreatment appeared to have no effect on the response of quail hepatic enzymes to HCB. There were no differences between the two groups in either the content of cytochrome P-450 or the activities of NADPH-cytochrome c reductase, glutathione transferase (microsomal or cytosolic), ethoxycoumarin-O-deethylase or ethoxyresorufin-O-deethylase following HCB treatment.
View Article and Find Full Text PDFRNA polymerase transcribed the hutUH operon of Klebsiella aerogenes if the catabolite gene activator protein (CAP) and cyclic AMP (cAMP) were present or if the DNA template was derived from a promoter mutant in which hutUH expression was independent of the need for positive effectors. In the absence of CAP or cAMP, not only was hutUH transcription absent, but transcription in the opposite direction (toward hutC) was initiated at a site (pC) ca. 70 base pairs from the site (pUH) of hutUH mRNA initiation.
View Article and Find Full Text PDFStrains of Caulobacter crescentus, Pseudomonas putida, Acinetobacter calcoaceticus, Rhizobium meliloti, and Rhodopseudomonas sphaeroides carrying the kanamycin resistance-encoding transposon Tn5 were 15 to 500 times more resistant to streptomycin than transposon-free strains. The streptomycin resistance determinant, which is separable from the kanamycin resistance determinant of Tn5, was not expressed in Escherichia coli or Klebsiella aerogenes.
View Article and Find Full Text PDFCulture fluids of Streptomyces tendae 4158 (ATCC 31210) contain a new kind of polypeptide alpha-amylase inhibitor, tendamistat (HOE 467). Several methods of isolating this inhibitor are described, including two rapid crystallisation methods, which produce homogeneous material. A characteristic of tendamistat is its tight-binding, pH-independent inhibition kinetics and the specific inhibition of the mammalian alpha-amylase form a stoichiometric 1:1 complex, which cannot be separated into its individual components by sodium dodecyl sulphate or molecular sieve chromatography.
View Article and Find Full Text PDFA continuous-flow system has been developed in which pancreatic alpha-amylase is incubated with soluble starch at 37 degrees C. Reducing sugars being delivered at the "steady-state" hydrolysis of starch are dialyzed into a solution of alkaline ferricyanide. Ferricyanide is then reduced at 95 degrees C.
View Article and Find Full Text PDFHosp Community Psychiatry
March 1984
The authors studied the discharge planning process at four inpatient facilities and its impact on 119 chronic schizophrenic patients over a one-year period. Adequacy of discharge planning varied significantly among the inpatient units; the authors attributed this variance to communication between inpatient and outpatient staff, staff-patient ratios, and staff effort. Overall, staff were most thorough in planning drug treatment and aftercare and least thorough in planning living arrangements in the community.
View Article and Find Full Text PDFAppl Environ Microbiol
February 1984
Infection of a strain lysogenic for bacteriophage P1 CM with P1::Tn5 followed by simultaneous selection for the chloroamphenicol resistance associated with the resident prophage and the kanamycin resistance associated with Tn5 results in a large number of independent Tn5 insertion mutations. This superinfection-selection protocol is a fast, easy, and safe way to isolate null mutations in enteric bacteria without generating unwanted cryptic mutations elsewhere in the genome.
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