Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “BAST”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 379 records · Page 21Linked to original sources
PubMed1990

Ceftazidime concentrations in renal cysts.

Levels of ceftazidime (CAZ) in uninfected renal cysts of 25 patients were investigated. Seventeen patients received 2 g CAZ about 140 min prior to puncture of the cysts (group I), and eight patients were treated with 2 x 2 g CAZ one day before, and with a further dose of 2 g 2 h prior to puncture (group II). In eight cases (two of group I and six of group II) the concentration of the cyst fluid was also assessed at 4 h and 6 h after completion of the CAZ infusion. In group I, CAZ concentrations were 0.5 to 1.13, micrograms ml-1, mean 0.71; in group II CAZ concentrations were 3.6 to 6.7 micrograms ml-1, mean 5.55. At 4 h and 6 h after infusion the mean cyst concentrations were 4.4 and 2.9 micrograms ml-1, respectively.

Adult↗
PubMed1993

Assignment of HLA-DPB alleles by computerized matching based upon sequence data.

Routine HLA typing by serology has been supported by DNA or protein analysis of the respective molecules in cases when serologic typing was inconclusive or difficult to perform. DNA analysis by RFLP, SSO, or PCR amplification with SSP is a reliable tool for the identification of alleles. Because DNA sequences may now be determined routinely, we developed software based on sequence data from known sequences for allele assignment of polymorphic gene systems. We describe the assignment of HLA-DPB alleles based upon sequence data obtained after PCR amplification and subsequent sequencing of exon 2. Our software includes a database containing all known HLA-DPB sequences, which offers the possibility of analyzing heterozygous individuals by combinatorial comparison through all alleles and thus identifying the one or two alleles involved. Quality control of the sequence has been included by the alignment of constant regions of the sequence combined with related polymorphism of known polymorphic nucleotides and the identification of the positions crucial for the allele assignment. The ability to type for HLA-DPB alleles routinely by automatic sequence determination and subsequent automated analysis offers new perspectives for HLA-DNA typing.

Alleles↗
PubMed1990

A patient with vertebrobasilar transient ischaemic attacks and provokable basilar steal.

In a 65-year-old woman with vertebrobasilar transient ischaemic attacks (TIAs) and subclavian steal, a steal phenomenon in the basilar artery could be demonstrated by transcranial Doppler sonography after provocation with postischaemic hyperaemia of the arm on the affected side. It was not possible to provoke symptoms or signs at the time. The significance of finding a steal phenomenon in the basilar artery even in a patient with a history of vertebrobasilar TIAs is discussed.

Aged↗
PubMed1995

Cultured rat striatal and cortical astrocytes protect mesencephalic dopaminergic neurons against hydrogen peroxide toxicity independent of their effect on neuronal development.

Reactive oxygen species (ROS), including hydrogen peroxide, are supposed to be involved in the degeneration of dopaminergic neurons in Parkinson's disease. The potential role of astrocytes against neurotoxic effects of ROS was studied in cocultures of rat mesencephalic neurons and rat striatal or cortical astrocytes. Neuronal [3H]dopamine uptake, a marker of dopaminergic neuron integrity, was enhanced by striatal astrocytes, but not by cortical astrocytes, compared to uptake in mesencephalic neurons cultured alone. Whereas hydrogen peroxide at concentrations up to 100 microM reduced the [3H]dopamine uptake in neuronal cultures, no reduction of the uptake was observed in cocultures, regardless of the origin of the supporting astrocytes. These results suggest that astrocyte mediated protection of neurons against hydrogen peroxide induced toxicity is not directly related to a region-specific neurotrophic effect.

Animals↗
PubMed1981

Comparison of the effects of inhibitors of cytochrome P-450-mediated reactions on human platelet aggregation and arachidonic acid metabolism.

Metyrapone and SKF-525A, together with amphenone B, a structural analogue of metyrapone, which are all inhibitors of cytochrome P-450-mediated reactions, were shown to inhibit the arachidonic acid-induced aggregation of human platelets. Amphenone B, like metyrapone, exhibited a type II (ligand) binding spectrum with rat liver microsomal cytochrome P-450, in contrast to SKF 525A which is a type I (substrate) binding agent. Independently of their type of binding spectra and of their maximum spectral change, however, the affinity of the three compounds for rat liver cytochrome P-450 showed a close proportional correlation with their platelet aggregation inhibitory potency. All three compounds inhibited the formation of [1-14C]thromboxane B2 from [1-14C]arachidonic acid by human platelets aggregated with collagen. The effect of metyrapone on the remaining labelled products suggested that it is a selective thromboxane synthesis inhibitor, while amphenone B exhibited activity reminiscent of cyclo-oxygenase inhibitors. SKF 525A produced complex effects possibly attributable to cyclo-oxygenase inhibition and enhanced lipid peroxidation, since it also enhanced platelet malonaldehyde formation, which the other two compounds inhibited. These data provide further support for a role of cytochrome P-450 in thromboxane synthesis and platelet aggregation.

Animals↗
PubMed1991

Fluoride is a contractile agent of guinea pig airway smooth muscle.

1. Guinea pig parenchymal lung strips and tracheal smooth muscle contract potently after NaF-addition. Maximal contractions of lung strips and tracheal rings induced by NaF were 208 +/- 17% (n = 6) and 151 +/- 8% (n = 4) of the maximal histamine response respectively. 2. The -log EC50-value for NaF on lung strips and tracheal rings was 2.38 +/- 0.01 (n = 6) and 2.28 +/- 0.01 (n = 4) respectively. 3. Contractions induced by NaF were augmented after Al3+ pretreatment, suggesting the involvement of a G-protein. NaF responses were not affected by blockade of H1-, muscarinic-, leukotriene C4- or leukotriene D4-receptors, indicating that mast cell degranulation or nerve activation is most probably not implicated. 4. Contractions after NaF-addition were relatively insensitive to removal of extracellular calcium and were reversed via cAMP- and cGMP-mediated pathways. 5. Relaxation studies with (-)isoprenaline and 8-bromo-cGMP on lung strips, precontracted to similar levels with either a H1-agonist, KCl or NaF, showed that the level of relaxation depends on the contractile agent that is used. 6. After precontraction with KCl (-)isoprenaline relaxes lung strips only to 58 +/- 9% (n = 5) of the initial contraction, whereas lung strips precontracted with NaF or a H1-agonist relax 114 +/- 8% (n = 4) and 120 +/- 7% (n = 5) respectively with (-)isoprenaline. 7. Similar results were obtained with relaxation induced with 8-bromo-cGMP. 8. These findings suggest that NaF-induced contractions are elicited via a mechanism, that is probably similar to that of the H1-receptor. The involvement of a G-protein in the observed NaF-responses is therefore likely.

Aluminum↗
PubMed1992

Glutathione mobilization during cerebral ischemia and reperfusion in the rat.

1. Cerebral ischemia applied for 15 min and followed by a 30 min reperfusion did not change the glutathione (GSH) levels and beta-adrenoceptor density (Bmax) in brain cortex. 2. A significant increase in erythrocyte-lysate GSH concentration (vs control) and a significant decrease of Bmax values in erythrocyte membranes (vs control) was found at the same time. 3. Pretreatment with the alpha-adrenoceptor antagonist phentolamine (5 mg/kg i.p.) prevented the erythrocyte GSH increase but not the decrease of Bmax value. Pretreatment with the beta-antagonist propranolol (2 mg/kg i.p.) did not influence the increase in erythrocyte GSH but circumvented the decrease of Bmax.

Animals↗
PubMed1995

Effect of dimethyl sulfoxide (DMSO) on the electrocardiogram (ECG) in freely moving male Balb/c mice.

1. Since dimethyl sulfoxide (DMSO) is a solvent which is often used for drugs in animal studies, we investigated the effect of a daily administration of DMSO on the telemetrically obtained electrocardiogram (ECG) in freely moving male Balb/c mice. 2. During treatment with 4.5 ml 100% DMSO/kg i.p. 5 days per week during 3 weeks, DMSO caused substantial cardiotoxicity. The ST-interval increased significantly after 1 week by 2.2 +/- 1.3 msec and also the ECG wave form changed completely in time. 3. During treatment with 4.5 ml 50% DMSO/kg i.p. 5 days per week during 3 weeks, no significant difference was observed compared with the control animals. 4. During the entire study the maximal heart rate and body weight remained constant in all treated groups. 5. The data indicate that DMSO can not be used in a 100% concentration to dissolve compounds that are tested for protection against the cardiotoxicity of cytostatics.

Animals↗
PubMed1989

Changes in receptor response by the effect of disease on membrane fluidity.

Currently, changes that occur in receptor function under (patho-) physiological conditions are being investigated. The molecular mechanisms causing the observed variations are largely unknown. It is suggested that the pivotal role of the fluidity of the membrane has been neglected in the literature. It is hypothesized that aberrations in receptor function in diseases that are associated with a concomitant mild oxidative stress can be explained by membrane wavering.

Humans↗
PubMed1987

Lesions in the preoptic area suppressed sexual receptivity in ovariectomized rats with estrogen implants in the ventromedial hypothalamus.

The objective of the experiment was to determine if electrolytic ablation of a portion of the preoptic area (POA) influenced the activation of female lordosis behavior by implants of estradiol benzoate in the ventromedial hypothalamus (VMH) of ovariectomized (OVX) rats. Two weeks after ovariectomy, rats received either bilateral electrolytic lesions (2 mA for 10 sec in Experiment 1, or 1 mA for 5 sec in Experiment 2) in the POA, or sham lesions (all procedures except passage of current). On the same day (day 0 of the experiment) thirty-gauge stainless steel cannulae containing crystalline estradiol benzoate were stereotaxically placed bilaterally into the VMH of all the rats. Subsequently, females were tested for the lordosis response to stud males on days 2, 4, 6, 8, and 10 in Experiment 1 or on days 7, 14 and 15 in Experiment 2. All rats received 0.5 mg progesterone (SC) only before the last test. A female was considered sexually receptive if she exhibited a lordosis quotient (LQ) greater than or equal to 10 (LQ = No. lordosis responses/10 mounts by male X 100). The frequencies for sexual receptivity in females with POA lesions were significantly lower than those for control females without lesions in both experiments. Additionally the degree of receptivity (lordosis quotient) was significantly lower on each test day for rats with POA lesions than that for rats without POA lesions. The results imply that the maintenance of the integrity of the POA under this experimental condition was important for the expression of the facilitative influence of the VMH on lordotic responsiveness.

Animals↗
PubMed1984

Adriamycin stimulates NADPH-dependent lipid peroxidation in liver microsomes not only by enhancing the production of O2 and H2O2, but also by potentiating the catalytic activity of ferrous ions.

The antitumor drug, adriamycin, enhances NADPH-dependent lipid peroxidation in liver microsomes via the formation of superoxide anion radicals (O2) and hydrogen peroxide (H2O2). In the presence of metal ions additional reactive species are generated, causing stimulation of lipid peroxidation. However, in this study it was found that the stimulation of NADPH-dependent lipid peroxidation by adriamycin was not only affected by the production of O2 and H2O2. Adriamycin also enhances the catalysis by metal ions of the formation of those reactive oxygen species which initiate peroxidation. This was inferred from the fact that adriamycin stimulated malondialdehyde production at low ferrous ion concentrations, whereas at high ferrous ion concentrations no stimulation was found. Additional evidence was found in experiments in which the enzymic redox cycle of adriamycin in microsomes was abolished by heat-inactivation of the microsomes, and O2 and H2O2 were only produced with xanthine and xanthine oxidase. In this case in the presence of ferrous ions, adriamycin stimulated lipid peroxidation.

Animals↗
PubMed1985

Effect of vitamin E on the balance between pro- and antioxidant activity of ascorbic acid in microsomes from rat heart, kidney and liver.

The effect of the vitamin E status of membranes on the balance between pro- and antioxidant activity of ascorbic acid was studied in microsomes from rat heart, kidney and liver. Lipid peroxidation was initiated by 5 microM ferrous ions, in combination with amounts of ascorbic acid ranging from 0-4 mM. Lipid peroxidation was assessed after 1 h of incubation as production of thiobarbituric acid reactive material. It was found that the vitamin E status of the microsomal membranes had little effect on the balance between pro- and antioxidant activity of vitamin C. The sensitivity of the membranes to ferrous ions/ascorbic acid-induced lipid peroxidation, however, was highly dependent on the vitamin E content of the membranes. Vitamin E depletion, in combination with different ascorbic acid concentrations, showed that vitamin E deficiency is not an incontestable model system for enhanced sensitivity to lipid peroxidation in all organs.

Animals↗
PubMed1989

The effects of radical stress and N-ethylmaleimide on rat hepatic alpha 1-adrenergic receptors.

Liver plasma membranes of non-treated rats or rats treated with carbon tetrachloride were prepared. Liver plasma membranes obtained from non-treated rats were preincubated with cumene hydroperoxide, N-ethylmaleimide or hydrogen peroxide in the absence or presence of Fe2+. The effects of in-vivo or in-vitro treatment on hepatic alpha 1-adrenergic receptors were assessed in a [3H]prazosin binding assay. All treatments except preincubation with hydrogen peroxide alone caused a decrease in the number of alpha 1-adrenergic receptors without a change in the affinity of [3H]prazosin. The decrease in receptor number was accompanied by an increase in the level of lipid peroxidation in the plasma membranes. The results indicate that the hepatic alpha 1-adrenergic receptor is vulnerable to free radical stress.

Animals↗
PubMed1991

Simple and sensitive quantification of anthracyclines in mouse atrial tissue using high-performance liquid chromatography and fluorescence detection.

Anthracyclines are very effective against soft tissue sarcomas, with cardiotoxicity being an important side effect after repeated administration. To estimate the relative cardiotoxicity of various anthracyclines and their metabolites, we developed an isolated mouse left atrium model. To relate an effect of doxorubicin, 4'-epidoxorubicin and their four main metabolites (doxorubicinol, epidoxorubicinol and the aglycons 7-deoxydoxorubicinon and 7-deoxydoxorubicinolon) to concentrations in the tissue instead of the incubation bath, a method of quantifying the anthracyclines in small tissue samples was developed. Atria were homogenized by sonication followed by extraction of the anthracyclines with methanol. The extract was directly analyzed by high-performance liquid chromatography with fluorescence detection. Recoveries for the six compounds tested ranged from 67.5% for 4'-epidoxorubicin to 100.6% for 7-deoxydoxorubinol aglycon with coefficients of variation of 2-3% at two spiked concentrations (0.1 and 1 nmol/mg of tissue). The calibration plots were linear (r2 greater than 0.996) over the concentration range tested (0.05-1 nmol/mg wet weight). The limits of detection (4-10 pmol/mg of tissue) were low enough to allow the determination of the anthracyclines at all relevant tissue concentrations.

Animals↗
PubMed1992

Fully automated determination of a new anthracycline N-l-leucyldoxorubicin and six metabolites in plasma by high-performance liquid chromatography with on-line sample handling.

N-l-Leucyldoxorubicin (Leu-Dox) was developed as a prodrug of doxorubicin (Dox) in order to diminish the cardiotoxic side-effect associated with repeated anthracycline treatment. To study the pharmacokinetics of Leu-Dox, Dox and other metabolites a sensitive and selective assay was needed. Leu-Dox and six of its known metabolites were extracted from plasma using an in-line reversed-phase precolumn (40-50 microns C8 particles). The trapped analytes were subsequently flushed to the analytical column (3 microns C18) using 0.5 ml of phosphate buffer (pH 3.5)-acetonitrile (2:1, v/v), which also served as the isocratic mobile phase. Within 12 min, a clean baseline-resolved chromatogram is obtained by fluorescence detection. Recoveries were almost quantitative and highly reproducible, with standard deviations less than or equal to 5.4% and less than or equal to 2.7% at spiked concentrations of 10 and 100 nM. Using 300 microliters of plasma, detection limits ranged from 0.3 to 0.8 nM at a signal-to-noise ratio of 3. The calibration curves were linear from 1 to 300 nM (r2 greater than or equal to 0.999) for each of the seven compounds. The between-day accuracy was in the range 91-99% and 99-105% at 10 and 100 nM, respectively, with standard deviations of 1-4%. Application of the assay to the analysis of plasma from patients after administration of Leu-Dox proved successful.

Antibiotics, Antineoplastic↗
PubMed1988

Influence of circulating antigen on blood pool activity of a radioiodinated monoclonal antibody.

Athymic mice with and without circulating CA 125 antigen were injected with 0.1-100 micrograms of 131I-labeled OC 125 F(ab')2 antibody fragment. Both the blood clearance of 131I activity and the change in serum CA 125 were monitored over 24 h. Influence of CA 125 on blood pool activity could be avoided only at the 100 micrograms dose. In patient studies, circulating CA 125 levels decreased for the first 2 h after injection of OC 125 F(ab')2 but generally returned to preinjection levels shortly thereafter. In vitro binding studies using the sera from patients injected with 131I-labeled OC 125 F(ab')2 suggest that circulating CA 125 could interfere with the tumor uptake of the labeled antibody.

Animals↗