A pencillinase-specific ribonucleic acid component from Bacillus cereus. II. Partial characterization of the active component.
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Bacillus cereus↗
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Rapidly and slowly activating components of delayed rectifier K(+) current in guinea-pig sino-atrial node pacemaker cells.
The components and properties of the delayed rectifier K(+) current (I(K)) in isolated guinea-pig sino-atrial (SA) node pacemaker cells were investigated using the whole-cell configuration of the patch-clamp technique. An envelope of tails test was conducted by applying depolarizing pulses from a holding potential of -50 mV to +30 mV for various durations ranging from 40 to 2000 ms. The ratio of the tail current amplitude elicited upon return to the holding potential to the magnitude of the time-dependent outward current activated during depolarizing steps was dependent on the pulse duration, while after exposure to the selective I(Kr) inhibitor E-4031 (5 microM) this current ratio became practically constant irrespective of the pulse duration. These observations are consistent with the presence of the E-4031-sensitive, rapidly activating and E-4031-resistant, slowly activating components of I(K) (I(Kr) and I(Ks), respectively) in guinea-pig SA node cells. The activation range for I(Kr), defined as the E-4031-sensitive current (half-maximal activation voltage (V(1/2)) of -26.2 mV) was much more negative than that for I(Ks), defined as the E-4031-resistant current (V(1/2) of +17.2 mV). I(Kr) exhibited a marked inward rectification at potentials positive to -50 mV, whereas I(Ks) showed only a slight rectification. In the current-clamp experiments, bath application of E-4031 (0.5 and 5 microM) initially slowed the repolarization at potentials negative to approximately -30 mV and produced a significant depolarization of the maximum diastolic potential, followed by the arrest of electrical activity, thus indicating that the late phase of the repolarization leading to the maximum diastolic potential at around -60 mV in spontaneous action potentials is primarily produced by I(Kr) in guinea-pig SA node cells. External application of the selective I(Ks) inhibitor 293B (30 microM) also delayed the repolarization process at potentials negative to about -20 mV and induced moderate depolarization of the maximum diastolic potential leading to the arrest of the spontaneous activity. These results provide evidence to suggest that both I(Kr) and I(Ks) are present and play crucial roles in the spontaneous electrical activity of guinea-pig SA node pacemaker cells.
Animals↗
Antibacterial active components in human urine after administration of penicillins.
Four-hourly urine from volunteers and patients who had received penicillins orally or intravenously was investigated by means of thin layer chromatography and bioautography. Antibacterially active metabolites were not detected with only two of 12 penicillins, namely amoxicillin and mezlocillin. In the case of the other penicillins the metabolites possessed variable antibacterial activity as could be demonstrated using different test microorganisms. After administration of carbenicillin esters three antibacterially active spots were detected, one of which corresponded to penicillin G; the other two were active against Pseudomonas aeruginosa. The bioautogram after treatment with azlocillin showed two components which were active against Bacillus subtilis, Staphylococcus aureus and Escherichia coli; only the rapid moving component was active against P. aeruginosa, however. The formation and chemical nature of these additional active components is still to a large extent not understood. It is quite possible, however, that they affect the bio-availability of an antibiotic.
Administration, Oral↗
Effects of glycyrrhizin, an active component of licorice roots, on Candida albicans infection in thermally injured mice.
Due to the generation of burn-associated CD8+ CD11b+ TCR gamma/delta+ type 2 T cells (burn-associated type 2 T cells), the susceptibility of thermally injured mice to infection with C. albicans has been shown to be increased by up to 50-fold when compared with normal mice. Glycyrrhizin (GR), an active component of licorice roots, reduced the susceptibility of thermally injured mice to C. albicans infection to levels observed in normal mice. Thermally injured mice inoculated with CD4+ T cells from GR-treated mice were also resistant to C. albicans infection. The following demonstrated that susceptibility to fungal infection was similar in thermally injured mice and normal mice inoculated with T6S cells (a clone of burn-associated type 2 T cells). This susceptibility of T6S mice (normal mice inoculated with T6S cells) was reversible by (i) administration of GR, (ii) inoculation of CD4+ T cells from GR-treated mice, and (iii) injection of a mixture of MoAbs targeted against type 2 cytokines (IL-4 and IL-10). After stimulation with anti-CD3 MoAb, splenic T cells from thermally injured and T6S mice, treated with GR or inoculated with CD4+ T cells from GR-treated mice, did not have type 2 cytokines in culture supernatants. They were present in splenic T cell cultures from thermally injured and T6S mice that were treated with saline or inoculated with naive T cells. These results suggest that GR, by inducing CD4+ T cells which suppress type 2 cytokines produced by burn-associated type 2 T cells, improves the resistance of thermally injured mice to C. albicans. An anti-type 2 T cell action of the CD4+ T cells derived from GR-treated mice was previously described.
Amphotericin B↗
(Z,E)-alpha-farnesene--an electroantennogram-active component of Maladera matrida volatiles.
It has previously been shown in field-trapping experiments and laboratory olfactometer bioassays that virgin females of Maladera matrida Argaman (Coleoptera, Scarabaeidae) and their volatiles, both in the presence of food (cut peanut leaves), are efficient attractants for M. matrida males and females. In this study GC-EAD experiments using male antennae and GC-MS experiments revealed that (Z,E)-alpha-farnesene is an active component of M. matrida female volatiles. The identification and quantitive electrophysiological responses (EAG) of synthetic (Z,E)-alpha-farnesene were obtained with male and female antennae. It was also shown that (Z,E)-alpha-farnesene is not a component of the plant volatiles that serve as synergistic components of the mixture of attractants or of the source of food for M. matrida.
Animals↗
Free radical scavenging active components from Cedrus deodara.
An activity-directed fractionation and purification process was used to identify the antioxidant components of Cedrus deodara. Dried heartwood powder of C. deodara was first defatted with petroleum ether and then extracted with chloroform. The chloroform extract showed strong antioxidant activity on 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical. This fraction was then subjected to separation and purification using silica gel column chromatography. Three compounds with potent antioxidant activity were isolated in significant yields and identified by spectroscopic methods ((1)H NMR, (13)C NMR, IR, and MS). They were identified as (-)-matairesinol, (-)-nortrachelogenin, and a dibenzylbutyrolactollignan (4,4',9-trihydroxy-3,3'-dimethoxy-9,9'-epoxylignan). This is the first report of the occurrence of these compounds in C. deodara.
Antioxidants↗
[Determination of active components of amrinone by analysis of pressure-volume results; use of the conductance (volume) catheter technic and rapid load change by balloon occlusion of the inferior vena cava].
Endsystolic pressure-volume relationships (ESPVR) were determined using the conductance (volume) catheter-technique and the required rapid load changes by applying vasoactive drugs (nitroprusside = NP; phenylephrine = PE) or brief preload reduction by balloon occlusion of the vena cava inferior (BOVCI). With this load-independent index of contractility, we analyzed the hemodynamically active components of amrinone (AM) over a range of different LV-loading conditions. In 19 patients (study I) with still normal LV-function (LVF) in group A (dP/dtmax 1585 +/- 386 mmHg/s; n = 10) and impaired LVF in group B (dP/dtmax 1044 +/- 164 mmHg/s; n = 9) an infusion of AM, 1.5 mg/kg over 2 min, failed to induce changes in ESPVR (p greater than 0.05), but rather caused load changes, resembling like those seen with NP. During continuously paced heart rates (90/min) brief infusion phases with NP and PE provided the necessary load changes. In 11 patients (study II) with impaired LVF (dP/dtmax = 1177 +/- 163 mmHg/s) 2.5 mg/kg AM i.v. induced an increase in contractility, which was more pronounced after the additional application of dobutamine (DOB) at 10 micrograms/kg/min.; (1) Slope k rose from 0.52 to 0.80 mmHg/ml; (2) dP/dtmax increased by an average of 39% and 57% (p less than 0.01), respectively. The BOVCI provided the necessary load changes. Thus AM demonstrates its contractility-increasing effects in a dose-related fashion, probably (at least in part) via an increase in heart rate; inotropic effects further increased with the combination of AM and DOB. The use of the conductance technique for the assessment of ESPVR during acute decrease of preload by temporary BOVCI is innocuous to the patient, reproducible and can be carried out under the conditions of a routine cardiac catheter procedure. This technique seems to be useful in the assessment of relative inotropic effects of the newer cardiotonic drugs.
Amrinone↗
Demonstration of an active component of inter-alpha-trypsin inhibitor in the brains of Alzheimer type dementia.
The putative precursor of A4 amyloid protein associated with Alzheimer's disease is known to have a domain with an amino acid sequence characteristic of a Kunitz-type serine protease inhibitor. Human serum inter-alpha-trypsin inhibitor (ITI) is the most similar inhibitor. We screened brain tissues with senile dementia of the Alzheimer type in an attempt to detect ITI immunoreactivity employing immunohistochemical methods. For this purpose, we used the antibody raised against acid-stable proteinase inhibitor (ASPI) which is an active component of ITI. ASPI immunoreactivity was found to be localized in diffuse type senile plaques, the perivascular area and subpial layer. Reactive astrocytes with intense ASPI immunoreactivity were present in the pyramidal layer of the parahippocampus, where loss of neurons was observed. These findings suggest that ITI may be related to the pathogenesis of Alzheimer type dementia.
Aged↗
Active components of excitability in K+-depolarized ventricular muscle.
The steady-state and dynamic characteristics of excitability were assessed in isolated guinea pig papillary muscles depolarized with elevated [K+]o to resting potentials near -60 mV. Transmembrane potentials were recorded from fibers during application of low-amplitude current pulses used to analyze net changes in active membrane components of excitability in terms of elicited local responses and measure threshold current (Ith). Generated local responses were blocked entirely by tetrodotoxin and lidocaine, which increased steady-state Ith by more than 200%. In the absence of Na+ channel-blocking agents, local responses showed marked but characteristic attenuation in a time- and voltage-dependent manner by preceding subthreshold depolarizations, which concomitantly reduced excitability. However, local responses and excitability were also modulated by small changes in [Ca2+]o (+/- 0.7 mmol) and reduced by exposure to slow channel blockers and to Cs+. Thus these data suggest that while the Na+ channel is the primary active component of excitability in partially depolarized ventricular muscle, Ca2+ -mediated and Cs+ -sensitive conductances may also participate, although to a lesser extent. These findings may help explain the frequency-dependence of excitability and conduction under conditions of ischemia in the intact heart.
Animals↗
Base plate wax, dimensional stability and sorption of active components following treatment with disinfectant solutions.
The influence of seven disinfectants on the dimensional stability of a base plate wax, Tenax, was studied. Two methods for treatment were tested - immersion for one hour and spraying respectively. After spraying no significant influence on the wax could be established and after immersion four of the seven disinfectants, including Cidex and K-644, likewise had no significant influence on the dimensional stability. The wax specimens did not show any significant weight increase (less than one per cent) after immersion for four days but in four disinfectant solutions the surface properties of the wax specimens had changed showing that active components of the disinfectants were absorbed into or adsorbed on the wax surface.
Absorption↗
Quantitative analysis of the active components and the by-products of eight dry extracts of Hypericum perforatum L. (St John's Wort).
The major components of eight different batches of commercially available dry extracts of Hypericum perforatum L. were quantified. Hyperforin (1), hypericin (2) and flavonoids, which are considered to play key roles in the treatment of mild and moderate depressive disorders, were determined by HPLC methods. The contents of 1, 2 and flavonoids were found to be in the range of 1.3-3.9%, 0.19-0.30%, and 4.8-11.4%, respectively. Generally extracts contained, besides the so-called active components, a wide variety of by-products which may act partially as co-effectors and affect the technological properties of the extracts. Water-soluble sugars form one of the main groups of these by-products, and a procedure for the purification and quantification of such sugars in H. perforatum using HPLC with refractive index detection has been established. Native fructose, glucose and sucrose, as well as lactose added during the processing of the extracts, were determined. The total sugar content in the dry herbal extracts varied from 19 to 25% by weight. Further, citric acid (0.9-2.3%) and malic acid (2.3-3.1%) were determined by HPLC, tannins (6.2-9.0%) and total ash (4.9-8.4%) were quantified according to the methods described in the European Pharmacopoeia, and the content of the total protein (3.9-8.3%) was estimated by elemental analysis. Thus, 60-70% of the compounds of the H. perforatum dry extracts have been quantified.
Anthracenes↗
Tear fluid content of electrochemically active components including water soluble antioxidants.
PURPOSE: To describe the content of water-soluble antioxidants in tear fluid. METHODS: We collected tear fluid from healthy subjects, either into borosilicate glass tubing or by absorption onto Schirmer strips. High pressure liquid chromatography with electrochemical detection provided data on several components in a single assay. The system was sufficiently sensitive to provide reliable values for components present in tear fluid collected at normal (basal) or stimulated rates of secretion. RESULTS: Tear fluid at basal secretion was found to contain four compounds often considered to function in biology as antioxidants. Ascorbic acid (AA) is found at 665 microM, tyrosine at 45 microM and glutathione (GSH) at 107 microM. Cysteine (48 microM) and uric acid (328 microM) are reported for the first time; the latter is somewhat controversial as a physiologically active antioxidant. One peak on the chromatogram was consistently present but has not been identified. During stimulation of flow by brief inhalation of ammonium hydroxide fumes, the concentration of each compound was lower. CONCLUSION: This work demonstrates the presence of electro-chemically active components that might function as antioxidants at the anterior surface of the cornea against potential damage from radiation, oxygen toxicity, abrasion and environmental chemicals.
Adult↗
The herbal medicine Dai-kenchu-to and one of its active components [6]-shogaol increase intestinal blood flow in rats.
The present study investigated the effects of the herbal medicine Dai-kenchu-to (DKCT) and its 4 individual ingredients on intestinal blood flow (IBF) in rats by laser Doppler flowmetry. Intraduodenal administration of DKCT (30, 100 and 300 mg/kg) increased IBF in a dose-dependent manner, whereas the mean arterial blood pressure was not affected. One of the ingredients in DKCT is dried ginger rhizome (150 mg/kg), whose main component is [6]-shogaol (2 mg/kg), both of which showed similar effects to those shown by DKCT, while the other ingredients in DKCT only slightly increased IBF or had no effect. The calcitonin gene-related peptide (CGRP) receptor antagonist, CGRP (8-37), completely abolished the hyperemia induced by DKCT, dried ginger rhizome and [6]-shogaol. However, the vasoactive intestinal polypeptide (VIP) receptor antagonist, [4-Cl-DPhe6, Leul7]-VIP, and atropine were less inhibitory than CGRP (8-37), and the substance P (SP) receptor antagonist, spantide, had no effect. The present study demonstrated that DKCT and one of its active components, [6]-shogaol, produced an increase in IBF which was mainly mediated by CGRP and suggests that DKCT may be useful in the treatment of intestinal ischemia-related diseases.
Animals↗
Reduction of aflatoxins by Korean soybean paste and its effect on cytotoxicity and reproductive toxicity--part 1. Inhibition of growth and aflatoxin production of Aspergillus parasiticus by Korean soybean paste (Doen-jang) and identification of the active component.
The inhibitory effect of methanol extract of Korean soybean paste on the mold growth and aflatoxin production of a toxigenic strain of Aspergillus parasiticus ATCC 15517 was studied using different concentrations of the extract in yeast-extract sucrose broth. While inhibition in mold growth due to increasing the concentration of the extract was observed, the more remarkable effect was the inhibition of aflatoxin production. Reduction of mycelial weight as a result of addition of the extract was observed to range between 1.5 to 12.9% while reduction of aflatoxin production quantified by high-performance liquid chromatography ranged from 14.3 to 41.7%. Five percent of the extract significantly reduced aflatoxin production at the end of the incubation period (P < 0.05), although the effect on mycelial growth was less pronounced. This study indicates that soybean paste could also be an effective inhibitor of aflatoxin production even though mycelial growth may be permitted. The main active component identified by gas chromatography-mass spectroscopy was linoleic acid.
Aflatoxins↗
Uridine as an active component of sleep-promoting substance: its effects on nocturnal sleep in rats.
A 10-h intraventricular infusion of 10 pmol of uridine from 19.00 to 05.00 h resulted in significant increases in sleep in otherwise saline-infused male rats (n = 8) during the environmental dark period (20.00-08.00 h). Increments of slow wave sleep (SWS) and paradoxical sleep (PS) were 21.0% and 68.1%, respectively, of the baseline value. This was due to increases in the frequencies of both SWS and PS episodes but not to their durations. Similar increases occurred the first recovery night under saline infusion, but sleep amounts returned to the baseline levels the second night. Brain temperature was not affected by uridine administration. A small dose of uridine (1 pmol/10 h) exerted no effect (n = 6) while larger doses (100 and 1000 pmol/10 h, each n = 5) resulted in slight but insignificant increases in SWS and PS. The 1000-pmol uridine administration seemed to be non-physiological since it brought about irregularities in locomotor activity and sleep-waking rhythms. Thus, authentic uridine exhibited the same sleep-enhancing effects as a naturally occurring active component of sleep-promoting substance, which was recently identified with uridine.
Animals↗
Ascorbate-2-phosphate in red cell preservation. Clinical trials and active components.
A red cell additive solution (AS-005) containing ascorbate-2-phosphate (AsP) to maintain 2,3-diphosphoglycerate, plus adenine, phosphate, and mannitol to retain viability and reduce hemolysis, was evaluated by human clinical trials. A crossover design was used with another additive solution (Nutricel AS-3, Cutter Laboratories) serving as the control for each donor. Each additive solution was evaluated at 35 and 42 days of storage. There was no significant difference between the red cell viability of the two storage solutions at either time period. Split-bag, AS-005 in vitro studies at two temperatures (2.5 and 5.5 degrees C), both within the range of 1 to 6 degrees C approved by the American Association of Blood Banks and the Food and Drug Administration, resulted in dramatically different in vitro parameters, including a threefold difference in 2,3-diphosphoglycerate (2,3-DPG), a fivefold difference in glucose, and significant differences in pH and adenosine triphosphate. High-pressure liquid chromatography data confirmed the preliminary report that 1 to 2 percent (wt/wt) oxalate was present in preparations of AsP. In vitro storage data confirmed that oxalate is the active component of AsP that preserves 2,3-DPG during storage.
2,3-Diphosphoglycerate↗
Site-directed mutations in the potyvirus HC-Pro gene affect helper component activity, virus accumulation, and symptom expression in infected tobacco plants.
Helper component (HC-Pro) is a virus-encoded nonstructural protein required for aphid transmission of potyviruses. In the tobacco vein mottling virus (TVMV) polyprotein, HC-Pro represents a 457 residue polypeptide from amino acid position 257 to 713. Previous sequence comparison studies have suggested that mutations of one or two specific amino acid residues in the HC-Pro protein might result in loss of aphid transmission activity. To test this hypothesis, the initial targets were the residues corresponding to these specific amino acids, a lys to glu change and an ile to val change at amino acid positions 307 and 482, respectively, of the TVMV polyprotein, as well as the combination of the two. Two additional mutations within the HC-Pro representing dipeptide changes thr-ser to ile-asp and thr-ala to leu-glu at amino acid positions (283/284) and (368/369), respectively, were also tested to further define the effects of mutations in this region on helper component activity. The mutations at positions 482 and (368/369) had no effect on aphid transmission activity, while mutation at position 307 completely abolished the activity. Except for the 482 mutation, all the mutations also affected symptomatology and virus accumulation in infected plants. Due to the very low concentrations of HC-Pro in plants infected with the (283/284) mutant, the effect of this dipeptide change on aphid transmission activity could not be assessed. The majority of the tested mutations fall within a putative zinc-finger motif postulated in the cysteine-rich N-terminus of HC-Pro. The possible role of this motif in the potyviruses is further discussed in the light of our present results with TVMV.
Animals↗
[Isolation and structure of the active component of the antitumor agent blastolysin].
Active principle of blastolysin, comprising ca. 40% of the total weight of Lactobacillus bulgaricus cell wall preparation, has been isolated and structurally studied by chemical and spectral methods. The substance a glycopeptide with Mr aa. 10,000, consists of two tetrasaccharide moieties connected by oligopeptide bridges; glycerophosphate, glucose, and galactose moieties are also attached to N-acetylmuramyl residue of the peptidoglucan core. Tetrasaccharide-containing muramylpeptides were shown to be responsible for the antitumour activity.
Amino Acid Sequence↗