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At least 631 records · Page 35Linked to original sources
PubMed1994

Comparison of contrast-enhanced computed tomography and gadolinium-enhanced magnetic resonance imaging one year after lumbar discectomy.

Computed tomography (CT) and magnetic resonance imaging (MRI) with intravenous contrast were performed on a prospective group of 35 consecutive patients 1 year after surgery for disc herniation. The aim of the study was to compare the two methods in the analysis of postoperative changes. Computed tomography showed, compared with MRI, more extensive scar tissue in 12 patients and increased deformation of the dural sac in 5 patients. However, the nerve root was better delineated by MRI, and this facilitated the assessment of root thickening in 13 patients and root displacement, which could not be seen by CT in seven patients. MRI revealed four small protrusions that were not visible with CT. The two methods were found to be of equal value in regard to findings such as disc herniations and foraminal stenosis, which might influence the surgeons decision to perform repeat surgery.

Adolescent↗
PubMed1992

Enhancing effects of fluorescein on beta-lactam rash. II: Enhancing effects of fluorescein on generalized rash induced by beta-lactam antibiotics in guinea pigs.

Healthy volunteers, who were receiving intravenous injections of cefclidin (CFCL) with frequent concomitant use of fluorescein (F) and oxybuprocain (O) in the eyes for measurement of ocular tension, developed drug eruptions at the high frequency of 66.7%. The injection of CFCL alone induced the eruptions at an incidence of 2.8%. The cause of this high eruption rate was thought to be the simultaneous treatment with F and/or O. Therefore, we conducted experiments with CFCL-induced generalized rash (GR) in guinea pigs. Guinea pigs treated with F and O during both the phases of immunization and intraperitoneal elicitation developed CFCL rashes at a high frequency. This CFCL-rash was augmented by the treatment with F during either phase, but not by the treatment with O. Skin testing induced delayed type hypersensitivity (DTH) reaction to O in some animals, but the DTH to F was not induced in animals immunized with F in complete Freund's adjuvant. Furthermore, F augmented rashes induced not only by CFCL but also by other beta-lactam antibiotics such as cefsulodin and sulbenicillin. Accordingly, it is likely that F played a dominant role in the high incidence of drug eruptions during the volunteer trials with measurement of ocular tension.

Animals↗
PubMed2005

Lecozotan (SRA-333): a selective serotonin 1A receptor antagonist that enhances the stimulated release of glutamate and acetylcholine in the hippocampus and possesses cognitive-enhancing properties.

Recent data has suggested that the 5-hydroxytryptamine (5-HT)(1A) receptor is involved in cognitive processing. A novel 5-HT(1A) receptor antagonist, 4-cyano-N-{2R-[4-(2,3-dihydrobenzo[1,4]-dioxin-5-yl)-piperazin-1-yl]-propyl}-N-pyridin-2-yl-benzamide HCl (lecozotan), which has been characterized in multiple in vitro and in vivo pharmacological assays as a drug to treat cognitive dysfunction, is reported. In vitro binding and intrinsic activity determinations demonstrated that lecozotan is a potent and selective 5-HT(1A) receptor antagonist. Using in vivo microdialysis, lecozotan (0.3 mg/kg s.c.) antagonized the decrease in hippocampal extracellular 5-HT induced by a challenge dose (0.3 mg/kg s.c.) of 8-hydroxy-2-dipropylaminotetralin (8-OH-DPAT) and had no effects alone at doses 10-fold higher. Lecozotan significantly potentiated the potassium chloride-stimulated release of glutamate and acetylcholine in the dentate gyrus of the hippocampus. Chronic administration of lecozotan did not induce 5-HT(1A) receptor tolerance or desensitization in a behavioral model indicative of 5-HT(1A) receptor function. In drug discrimination studies, lecozotan (0.01-1 mg/kg i.m.) did not substitute for 8-OH-DPAT and produced a dose-related blockade of the 5-HT(1A) agonist discriminative stimulus cue. In aged rhesus monkeys, lecozotan produced a significant improvement in task performance efficiency at an optimal dose (1 mg/kg p.o.). Learning deficits induced by the glutamatergic antagonist MK-801 [(-)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine maleate] (assessed by perceptually complex and visual spatial discrimination) and by specific cholinergic lesions of the hippocampus (assessed by visual spatial discrimination) were reversed by lecozotan (2 mg/kg i.m.) in marmosets. The heterosynaptic nature of the effects of lecozotan imbues this compound with a novel mechanism of action directed at the biochemical pathologies underlying cognitive loss in Alzheimer's disease.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed1983

Spontaneously hypertensive rats exhibit an enhanced mydriatic response to clonidine. Evidence for enhanced sensitivity of central alpha 2-adrenoceptors.

Comparisons among spontaneously hypertensive (SHR), Kyoto Wistar (KW), and Wistar (W) rats were made of the functional states of central nervous system (CNS) alpha 2-adrenoceptors (clonidine-induced mydriasis) and nonvascular peripheral presynaptic alpha 2-adrenoceptors (clonidine-induced inhibition of the neurogenic twitch of the isolated vas deferens). While there were no differences among the strains of rats in the concentration of clonidine required to produce a 50% inhibition of the electrically evoked contractile response of the vas deferens, there was a significant reduction in the mean effective concentration (ED50) of clonidine to induce mydriasis in SHR as compared with KW and W rats. These observations indicate that CNS alpha 2-adrenoceptors may be functionally more sensitive in SHR. The data also suggest that the sensitivity of nonvascular presynaptic alpha 2-adrenoceptors, at least in the vas deferens, is not altered in hypertensive animals.

Animals↗
PubMed1987

Verapamil enhances brain function tolerance against severe hypoxia without enhancing cerebral blood flow in the rat.

In spontaneously breathing, lightly anesthetized rats with chronically implanted epicortical electrodes, tolerance times were measured from onset of progressive hypoxia, anoxia or decapitation, until ultimate apnea and subsequent cessation of brain electrical activities. Arterial and cerebrovenous blood was collected initially and during progressive hypoxia, starting 5 min after intravenous verapamil or NaCl (controls). Verapamil induced significant hyperpnea, arterial alkalosis, slight bradycardia and brain venous acidosis. During progressive hypoxia, hyperpnea persisted and heart rate remained stable for a longer period than in controls. Tolerance times were significantly prolonged. Time courses of arterial PO2 and PCO2 and of cerebrovenous PO2 were hardly influenced. However, arterial alkalosis and brain venous acidosis became highly significant versus control courses. This raised the O2 saturation in arterial and O2 extraction in cerebral venous blood. Sinus sagittalis puncture needle outflow (as a measure of CBF) tended to be below the control rat courses throughout. This led to a higher O2 supply to the brain in verapamil rats only during severe hypoxia. Verapamil did not prolong tolerance times in anoxia or ischemia. It is concluded that the verapamil-induced increase of tolerance to hypoxia is primarily due to the acid-base (Bohr) effects observed in response to hyperpnea and prolonged cerebral metabolic activity.

Animals↗
PubMed2006

Smoking particles enhance endothelin A and endothelin B receptor-mediated contractions by enhancing translation in rat bronchi.

BACKGROUND: Smoking is known to cause chronic inflammatory changes in the bronchi and to contribute to airway hyper-reactivity, such as in bronchial asthma. To study the effect of smoking on the endothelin system in rat airways, bronchial segments were exposed to DMSO-soluble smoking particles (DSP) from cigarette smoke, to nicotine and to DMSO, respectively. METHODS: Isolated rat bronchial segments were cultured for 24 hours in the presence or absence of DSP, nicotine or DMSO alone. Contractile responses to sarafotoxin 6c (a selective agonist for ETB receptors) and endothelin-1 (an ETA and ETB receptor agonist) were studied by use of a sensitive myograph. Before ET-1 was introduced, the ETB receptors were desensitized by use of S6c. The remaining contractility observed was considered to be the result of selective activation of the ETA receptors. ETA and ETB receptor mRNA expression was analyzed using real-time quantitative PCR. The location and concentration of ETA and ETB receptors were studied by means of immunohistochemistry together with confocal microscopy after overnight incubation with selective antibodies. RESULTS: After being cultured together with DSP for 24 hours the bronchial segments showed an increased contractility mediated by ETA and ETB receptors, whereas culturing them together with nicotine did not affect their contractility. The up-regulation of their contractility was blunted by cycloheximide treatment, a translational inhibitor. No significant change in the expression of ETA and ETB receptor mRNA through exposure to DMSO or to nicotine exposure alone occurred, although immunohistochemistry revealed a clear increase in ETA and ETB receptors in the smooth muscle after incubation in the presence of DSP. Taken as a whole, this is seen as the presence of a translation mechanism. CONCLUSION: The increased contractility of rat bronchi when exposed to DSP appears to be due to a translation mechanism.

Animals↗
PubMedDate not supplied

HMO innovations. Video-enhanced medical advice; senior zoo walkers; Group Health Resource Line; enhancing health education programs through desktop publishing; home health beat; innovative school health partnership.

The editors of HMO PRACTICE asked clinicians and health educators in HMOs across the country to submit reports on their unique, successful patient education programs. The following HMO Innovations testify to the wide range of new technologies, enterprising partnerships, and creative ideas that are shaping health education in HMOs today.

Creativity↗
PubMed1975

[Spleen enhancement reactions in chick embryo after homografting adult chicken spleen fragments: changes in spleen cell population in relation to rate of spleen enhancement].

A method using the comparison between the modifications of spleen weight and on spleen smears visible modifications of the distribution into categories of cells which are classified by the mean of their maturation degree, suggested that these both types of modifications are bound. Therefore, the classic cytological study seems to be a really good tool for analysing the effects of this kind of grafting on the haemopoietic organs, the weight modifications of which are difficult to measure. On the other hand, this method allowed us to see that the distribution of the cell population in the weakly enlarged spleens is very different from both distribution of the population in the strongly enlarged spleens and the controls ones ; this heterogeneity of the stimulating effect of the graft asked us the question whether this one could exerce its influence by the mean of two different ways, at least, or by only one.

Animals↗