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PubMed1977

Component activities in the autoregressive activity of physiological systems.

The higher-order autoregressive (AR) activity of a physiological system (Sato 1975a,b; Sato et al., 1977) was decomposed into first- and second-order activities. The former time-pattern displays a fast rise and an exponential decay, while the latter exhibits a damped sine wave. Application of this component analysis to EEG showed the first-order activity to coincide with the nonoscillatory delta component. The frequency distribution of the natural, damped and resonance frequencies of the second-order activities was found to show one, two or three modes in each frequency range of the delta, theta and beta rhythms in ninety normal adult EEGs. Hence, the second-order activities agree with the oscillatory delta, theta, alpha and beta rhythms. Some changes were induced not only in the frequency of theta and beta rhythms but also in that of alpha rhythm by over-breathing for about three minutes.

Electroencephalography↗
PubMed2005

Milk biologically active components as nutraceuticals: review.

Milk contains components that provide critical nutritive elements, immunological protection, and biologically active substances to both neonates and adults. Milk proteins are currently the main source of a range of biologically active peptides. Concentrates of these peptides are potential health-enhancing nutraceuticals for food and pharmaceutical applications. Several bioactive peptides may be used as nutraceuticals, for example, in the treatment of diarrhea, hypertension, thrombosis, dental diseases, as well as mineral malabsorption, and immunodeficiency. Minor whey proteins, such as lactoferrin, lactoperoxidase, lysozyme, and immunoglobulins, are considered antimicrobial proteins. Milk also contains some natural bioactive substances. These include oligosaccharides, fucosylated oligosaccharides, hormones, growth factors, mucin, gangliosides, and endogenous peptides, which are present in milk at secretion. Most of the claimed physiological properties of milk bioactive components have been carried out in vitro or in animal model systems, and these hypothesized properties remain to be proven in humans. Whether these milk bioactive components will replace drugs entirely in the immediate future is still unclear, but the increasing appreciation of "drug foods" or nutraceuticals plays a complementary rather than a substitutional role to the synthetic pharmacological drugs.

Animals↗
PubMed1992

Reliability of late positive component activity (P3) in healthy elderly adults.

Auditory oddball paradigms (20% targets) were used to elicit components of the event-related brain potential in healthy, late middle-aged and elderly adults (N = 32) in two separate sessions approximately 4.5 months apart. Within each session data were acquired under two conditions: (a) 250 Hz standard, 500 Hz target; and, (b) 1000 Hz standard, 2000 Hz target. Measures of P3 latency and amplitude showed moderate to high reliability (.55 to .89) over the 4.5-month interval under both stimulus conditions using data acquired from the midline frontal (Fz), central (Cz), and parietal (Pz) sites. In the second session, latencies were prolonged in the 500 Hz target tone condition, and amplitudes tended to be reduced in the 2000 Hz target tone condition. These results suggest that P3 measures in studies of older adults are reliable over time, and the findings are discussed in conjunction with prior P3 reliability studies of younger adults.

Aged↗
PubMed1985

Binding of active components of compound 48/80 to rat peritoneal mast cells.

The binding characteristics of compound 48/80 were examined using rat mast cells and fractionated 14C-labeled compound 48/80 components at 4 degrees C in vitro where no degranulation of the cells occurred. The binding potencies of these components in the presence of Ca2+ generally paralleled their histamine releasing activities, except in the case of fractions G (decamer) and H (nonamer), both Ca2+-independent releasers, for the binding of which Ca2+ was inhibitory. Scatchard analyses and displacement studies indicated that the mast cells had two types of binding sites with high and low affinities for fractions D (tridecamer, Ca2+-dependent releaser, Kd = 3.41 X 10(-8) M and 3.35 X 10(-6) M) and H (Ca2+-independent releaser, Kd = 1.11 X 10(-7) M and 9.11 X 10(-6) M), respectively. These sites partially overlapped each other, and also the fraction D site partially overlapped the IgE site and the fraction H site overlapped the neurotensin or substance P site.

Animals↗
PubMed2004

Extremely low bioavailability of magnesium lithospermate B, an active component from Salvia miltiorrhiza, in rat.

We assessed the bioavailability of magnesium lithospermate B (MLB), a main polyphenolic component of Salvia miltiorrhiza and a potent antioxidant having various pharmacological activities, to evaluate its action in vivo. The plasma concentrations of lithospermic acid B (LSB) showed a biexponential decrease after intravenous administration of MLB to rats at doses of 4 and 20 mg/kg. The values of area under the concentration-time curve (AUC; 87.8 +/- 10.9 and 1130 +/- 329 microg.min/mL), total body clearance (CL (tot); 55.52 +/- 7.07 and 23.51 +/- 5.98 mL/min/kg), and distribution volume at steady state (V (ss); 7.60 +/- 1.03 and 3.61 +/- 1.16 L/kg) suggested non-linear pharmacokinetics between the two doses. After oral administration of MLB at a high dose of 100 mg/kg, the mean AUC was barely 1.26 +/- 0.36 microg.min/mL. Absolute bioavailability of MLB was calculated to be 0.0002 from the AUC values after both intravenous dosing at 20 mg/kg and oral dosing at 100 mg/kg. The extremely low bioavailability was caused mainly by poor absorption from the rat gastrointestinal tract; about 65 % of the dose was retained in the tract even 4 h after oral administration, and most of the dose was retained even 20 min after infusion in an in situ jejunal loop experiment. Urinary and biliary excretion of LSB were only 0.70 % +/- 0.26 % and 5.10 % +/- 2.36 %, respectively, over a 30 h time period after intravenous injection despite the large CL (tot) and V (ss) values, and were much less (0.010 % +/- 0.001 % and 0.12 % +/- 0.04 %) after oral dosing. These findings suggest that extensive metabolism, including a first-pass effect, and wide distribution of LSB besides the poor absorption contributed significantly to the extremely low systemic bioavailability.

Administration, Oral↗
PubMed2002

Escherichia coli genes involved in resistance to pyrazinoic acid, the active component of the tuberculosis drug pyrazinamide.

The natural resistance of Escherichia coli to pyrazinoic acid (POA), the active derivative of pyrazinamide, was investigated. The TolC mutant was found to be more susceptible to POA and other weak acids than the wild-type strain. Mutation in EmrB but not AcrB efflux protein slightly increased POA susceptibility. Two transposon mutants with increased susceptibility to POA were found to harbor mutations in acnA encoding aconitase-1 and ygiY encoding a putative two-component sensor protein. Complementation of the AcnA and YgiY mutants conferred resistance to POA, whereas the complemented TolC mutant became resistant to POA and other weak acids.

Amidohydrolases↗
PubMedDate not supplied

[Effect of therapy with blood component (activated autoplasma) on blood glutathione level in patients with vascular abnormalities on the fundus oculi].

Thirty-three patients with central chorioretinal dystrophy, 18 with proliferative diabetic retinopathy, and 15 controls without ocular diseases were examined. All patients were treated by blood components. The treatment started with activation of blood plasma platelets. Glutathione was measured in two portions of plasma: intact and containing platelet activation products. The content of glutathione was higher in activated autoplasma of 21 patients with central chorioretinal dystrophy and 6 patients with diabetic retinopathy than in intact plasma by 107 and 72%, respectively. A decrease in glutathione level in activated autoplasma was observed in 1 patient with central chorioretinal dystrophy and in 9 with diabetic retinopathy. Hence, antioxidant defense is decreased in diabetic retinopathy, since glutathione is involved in reduction of organic hydroperoxides.

Adult↗
PubMedDate not supplied

[The synthesis of immunomodulating peptide alloferon, the active component of the antiviral drug allokine-alpha].

Two variants of the synthesis of tridecapeptide alloferon, the active principle of antiviral preparation allokine-alpha, were developed on the basis of fragment condensation in solution or on the Merrifield resin. The solid phase variant of the synthesis was shown to be more technological; it allows the preparation of the product at a higher total yield (40% vs. 17% for conventional synthesis in solution from the starting derivatives of the C-terminal dipeptide). The by-products formed during the synthesis of alloferon were identified.

Adjuvants, Immunologic↗
PubMed2003

Chylomicron components activate duodenal vagal afferents via a cholecystokinin A receptor-mediated pathway to inhibit gastric motor function in the rat.

Nutrients in the intestine initiate changes in secretory and motor function of the gastrointestinal (GI) tract. The nature of the 'sensors' in the intestinal wall is not well characterized. Intestinal lipid stimulates the release of cholecystokinin (CCK) from mucosal entero-endocrine cells, and it is proposed that CCK activates CCK A receptors on vagal afferent nerve terminals. There is evidence that chylomicron components are involved in this lipid transduction pathway. The aim of the present study was to determine (1) the pathway mediating reflex inhibition of gastric motility and (2) activation of duodenal vagal afferents in response to chylomicrons. Mesenteric lymph was obtained from awake rats fitted with lymph fistulas during intestinal perfusion of lipid (Intralipid, 170 micromol h(-1), chylous lymph) or a dextrose and/or electrolyte solution (control lymph). Inhibition of gastric motility was measured manometrically in urethane-anaesthetized recipient rats in response to intra-arterial injection of lymph close to the upper GI tract. Chylous lymph was significantly more potent than control lymph in inhibiting gastric motility. Functional vagal deafferentation by perineural capsaicin or CCK A receptor antagonist (devazepide, 1 mg kg(-1), i.v.) significantly reduced chylous lymph-induced inhibition of gastric motility. The discharge of duodenal vagal afferent fibres was recorded from the dorsal abdominal vagus nerve in an in vitro preparation of the duodenum. Duodenal vagal afferent nerve fibre discharge was significantly increased by close-arterial injection of CCK (1-100 pmol) in 43 of 83 units tested. The discharge of 88% of CCK-responsive fibres was increased by close-arterial injection of chylous lymph; devazepide (100 microg, i.a.) abolished the afferent response to chylous lymph in 83% of these units. These data suggest that in the intestinal mucosa, chylomicrons or their products release endogenous CCK which activates CCK A receptors on vagal afferent nerve fibre terminals, which in turn initiate a vago-vagal reflex inhibition of gastric motor function.

Animals↗
PubMed2002

Effects of ginsenosides, active components of ginseng, on nicotinic acetylcholine receptors expressed in Xenopus oocytes.

We investigated the effects of ginsenosides, the active ingredient of ginseng, on neuronal or muscle-type nicotinic acetylcholine receptor channel activity expressed in Xenopus oocytes after injection of cRNA encoding bovine neuronal alpha3beta4, alpha7 or human muscle alphabetadeltavarepsilon subunits. Treatment with acetylcholine elicited an inward peak current (I(ACh)) in oocytes expressing nicotinic acetylcholine receptor subtypes. Cotreatment with ginsenoside Rg2 and acetylcholine inhibited I(ACh) in oocytes expressing with alpha3beta4 or alphabetadeltavarepsilon but not in oocytes expressing alpha7 nicotinic acetylcholine receptors. The inhibition of I(ACh) by ginsenoside Rg2 was reversible and dose-dependent. The half-inhibitory concentrations (IC50) of ginsenoside Rg2 were 60.2+/-14.1 and 15.7+/-3.5 microM in oocytes expressing alpha3beta4 and alphabetadeltavarepsilon nicotinic acetylcholine receptors, respectively. The inhibition of I(ACh) by ginsenoside Rg2 was voltage-independent and noncompetitive. Other ginsenosides besides ginsenoside Rg2 also inhibited I(ACh) in oocytes expressing alpha3beta4 or alphabetadeltavarepsilon nicotinic acetylcholine receptors. The order of potency for the inhibition of I(ACh) was ginsenoside Rg2>Rf>Re>Rg1>Rc>Rb2>Rb1 in oocytes expressing alpha3beta4 nicotinic acetylcholine receptors and was ginsenoside Rg2>Rf>Rg1>Re>Rb1>Rc>Rb2 in oocytes expressing alphabetadeltavarepsilon nicotinic acetylcholine receptors. These results indicate that ginsenosides might regulate nicotinic acetylcholine receptors in a differential manner and this regulation might be one of the pharmacological actions of Panax ginseng.

Acetylcholine↗
PubMed1976

Synergism of immunogenic and adjuvant-active components of mycobacterial wax D in the induction of adjuvant arthritis.

Two derivatives of wax D, one possessing immunogenicity and the other adjuvant activity, were tested for the possible role in the induction of adjuvant arthritis (AA) in rats. The former, a water-soluble arthritogenic and immunogenic component (WAC), in incomplete Freund's adjuvant, was able to induce delayed hypersensitivity (DH) and mild AA, but failed to function as an adjuvant in rats. The latter, an acetylated wax D (AD) and its subfraction, AD6, did exert adjuvant activity, but were free from immunogenicity and arthritogenicity. The addition of AD or AD6 to the WAC in incomplete Freund's adjuvant, when injected into inguinal lymph nodes, resulted in the production of severe AA with high incidence. Other adjuvants such as pertussis vaccine and lipopolysaccharide could not replace AD6; they failed to enhance AA when combined with the WAC. Also, other mycobacterial antigen, PPD, could not replace wax D-derived WAC; it did not induce AA when coupled with AD6, although it did induce DH to PPD.

Adjuvants, Immunologic↗
PubMed1996

Metabolically active component of fat-free body mass: influences of age, adiposity, and gender.

Fat-free body mass (FFM) is often considered the metabolically active compartment and is widely used to adjust between-subject differences in resting energy expenditure for body composition. The use of FFM as the metabolically active portion of body weight makes the assumption that the body cell mass (BCM) component which is more difficult to measure, maintains a relatively constant relationship to FFM within and between subjects. The aim of this study was to test the hypothesis that BCM and FFM are associated independently of age, adiposity (as represented by body density), and gender in healthy white women and men. BCM and FFM were estimated by whole-body 40K-counting and dual-energy x-ray absorptiometry (DXA), respectively. Multiple regression analysis was used to model the relationships between BCM as the dependent variable and FFM, age, body density, and gender as potential independent variables. FFM alone explained 51% and 63% of between-individual BCM differences in women (n = 269) and men (n = 204) (both P = .0001), respectively. Age contributed significantly (P = .0001) to BCM prediction after adjusting first for FFM in both women and men. Body density also added significantly (P = .004 and P = .0001) to FFM and age prediction of BCM in women and men, respectively. Lastly, gender contributed significantly to the composite model, with 91% of between-individual differences in BCM explained by FFM, age, body density, and gender. Hence, BCM does not maintain a fixed relationship to FFM, as often assumed, but varies significantly and independently of FFM with age, adiposity, and gender. These findings have implications for the study of metabolic indices such as resting energy expenditure.

Absorptiometry, Photon↗
PubMed1979

[Mechanism of antimicrobial active components (author's transl)].

The extreme chemical heterogeneity of antimicrobial inhibitors may be compared with the large heterogeneity of the sites of attack. From the host of questions regarding the mechanism of action three problems are selected at random for discussion: 1. Penetration or transport of inhibitors into the cell. At least some of the inhibitors must penetrate into the cell and find their way to very specific points of action; and it does not go without saying that the antibiotics reach their targets without previously reacting with other cell components or without being "trapped" by the cytoplasmic membrane. In some instances an active transport, i.e. a "misuse" by antibiotics of a transport system for a substrate can be demonstrated. 2. Distribution of the targets in the cell. Distribution of the inhibitors over the possible targets is not uniform. The question why this is so remains unanswered. 3. The membrane as the point of attack for inhibitors. The probability that an inhibitor has a bactericidal effect also on resting cells is greatest with substances that act on the membrane. The question as to the function of the antibiotics for the active cell arises and the "defence function" of the antibiotics is called in question.

Anti-Bacterial Agents↗
PubMedDate not supplied

The influence of detergent, the active component of detergent and sodiumtripolyphosphate on the biochemical process of some fungi.

Detergent "Merix" (Merima-Krusevac) and its components, sodiumtripolyphosphate and ethoxyled oleyl-cetyl alcohol in defined concentrations have influence on the enzymatic activity, bioproduction of amino acids and proteins and total biomass of species Aspergillus niger (A. niger) and Fusarium oxysporum (F. oxysporum). Detergent in concentration of 1% vol., in some cases, significantly stimulated production of the majority of amino acids. Detergent and its components (ethoxyled oleyl-cetyl alcohol and sodiumtripolyphosphate) in concentration of 1% vol. showed different influences on the production of proteins by the species of fungi A. niger and F. oxysporum. The enzymatic activity of fungi A. niger and F. oxysporum changed from total inhibition up to partial or total stimulation under influence of investigated pollutants. Detergent, sodiumtripolyphosphate and ethoxyled oleyl-cetyl alcohol, all in concentration of 1% vol. have reduced the production of the biomass of fungi A. niger and F. oxysporum. Investigated fungi have shown different response to the used pollutants.

Aspergillus niger↗
PubMed1996

The anti-inflammatory activity of Scutellaria rivularis extracts and its active components, baicalin, baicalein and wogonin.

Five extracts (n-hexane, chloroform, ethyl acetate, n-butanol and water) of Scutellaria rivularis Benth. were evaluated for their anti-inflammatory activity against carrageenan-induced paw edema in rats and compared with indomethacin. The result indicated that chloroform extract proved to be the most effective in all of the extracts. Consequently, three major components (baicalin, baicalein and wogonin) of the chloroform extract were further tested for their anti-inflammatory activity using the same model. It was found that baicalin exhibits the greatest inhibition activity against carrageenan-induced rat paw edema.

Animals↗
PubMed1998

Pharmacologically active components of viticis fructus (Vitex rotundifolia). II. The components having analgesic effects.

The extract of Viticis Fructus appeared to have an analgesic effect, and was subjected to activity-guided separation using acetic acid-induced writhing in mice. The active fraction gave new compounds, vitexfolin A (1A), B and C, 10-O-vanilloylaucubin (3), dihydrodehydrodiconiferylalcohol-beta-D- (2'-O-p-hydroxybenzoyl)glucoside (4), and vanilloyl-beta-D-(2'O-p-hydroxybenzoyl)glucoside, together with agnuside (2) and erythro- and threoguaiacylglycerols. Compounds 1A and 2-4 showed significant writhing inhibition following oral administration at doses of 15, 50, 25, and 50 mg/kg, respectively. The effect on pressure pain threshold was tested using compounds 1A and 2 at a dose of 50 mg/kg, and only the former produced the analgesia. The analgesic effect of some related iridoid glucosides is also discussed.

Administration, Oral↗
PubMed2002

Analysis of the genetic variability of genes encoding the RNA III-activating components Agr and TRAP in a population of Staphylococcus aureus strains isolated from cows with mastitis.

The expression of Staphylococcus aureus virulence proteins is under the control of RNA III, a central pleiotropic regulator transcribed from the agr locus. RNA III is activated by at least two two-component systems, one encoded by the agr locus (AgrC-AgrA) and another encoded outside of this locus (TRAP-RAP). In this work, we developed new typing methods based on genes encoding these two systems, which we used to characterize a nonclonal population of S. aureus bovine mastitis isolates. Twelve agr restriction types were identified in this population, but the majority of strains (56.3%) were grouped in the R III-A1 type. No strain isolated from humans, whose agr sequence is available from GenBank, was found to belong to this major type. Restriction maps constructed for all of those agr variants allowed the linking of all types in an evolution scheme and their grouping in one of the four agr interference groups. This analysis indicates that groups 2, 3, and 4 probably evolved from the more frequently encountered type, which belongs to group 1. agr group 1 was also found to be the most prevalent (69.0% of the strains) and the most polymorphic interference group. By developing an agr group-specific multiplex PCR, we confirmed the above classification of strains in the agr interference groups. Four allelic variants of trap were also identified, indicating that this two-component system is also polymorphic. The majority of strains was grouped in the trap 1 type (71.8%). Whereas no relationships between agr group and trap types were found, strains of similar agr restriction type were also of similar trap type (with the exception of strains belonging to the agr R IV-A5 and R VI-A8 types). Our analysis indicates that S. aureus isolated from cows has predominantly a clonal structure and that the highly prevalent agr R III-A1, trap 1 type (56.3% of the strains) probably possesses a genetic background which endows it with superior ability to infect the bovine mammary gland.

Animals↗
PubMed1986

Kinetic evidence for activating and non-activating components of autophosphorylation of the insulin receptor protein kinase.

Reduced and carboxamidomethylated-lysozyme (RCAM-lysozyme) is an excellent substrate (Km = 13 microM) and a potent inhibitor of receptor autophosphorylation (Ki = 0.6 microM). By using these properties of RCAM-lysozyme autophosphorylation was resolved into two kinetically and functionally distinct components involving formation of phosphotyrosine on the receptor's beta-subunits: 1. Insulin-stimulated autophosphorylation is independent of autophosphorylation at other sites; activation of insulin receptor-catalyzed substrate phosphorylation is dependent upon this component of autophosphorylation, which is inhibited by RCAM-lysozyme. 2. Autophosphorylation at saturating RCAM-lysozyme concentration is insensitive to insulin and has little effect on substrate phosphorylation. Thus, only insulin-dependent receptor autophosphorylation is responsible for activation of kinase-catalyzed substrate phosphorylation.

Catalysis↗