Heterogeneity of gamma-aminobutyric acid type A receptors in mitral and tufted cells of the rat main olfactory bulb

Mitral and tufted cells of the olfactory bulb receive strong gamma-aminobutyric acid (GABA)-ergic input and express GABA(A) receptors containing the alpha1 or alpha3 subunit. The distribution of these subunits was investigated in rats via multiple immunofluorescence and confocal microscopy, by using gephyrin as a marker of GABAergic synapses. A prominent immunoreactivity was detected throughout the external plexiform layer (EPL) and glomerular layer (GL). However, although staining for the alpha1 subunit was uniform throughout the EPL, that of the alpha3 subunit was most intense in the outer one-third of this layer. All mitral cells were positive for the alpha1 subunit. In contrast, the alpha3 subunit was restricted to a subpopulation of mitral cells, many of which also expressed calretinin. Likewise, external tufted cells could be subdivided into distinct groups, either singly labeled for the alpha1 or alpha3 subunit or doubly labeled. At the subcellular level, staining for the alpha1 and alpha3 subunits was punctate, forming clusters partially colocalized with gephyrin. However, many alpha1- and alpha3-positive clusters lacked gephyrin, suggesting the existence of either nonsynaptic GABA(A) receptor clusters or synaptic receptors not associated with gephyrin. Quantitative analysis of colocalization among the three markers in the inner EPL, outer EPL, and GL revealed considerable heterogeneity, suggestive of a differential organization of GABA(A) receptor subtypes in the apical and basal dendrites of mitral and tufted cells. Together these results reveal a complex subunit organization of GABA(A) receptors in the olfactory bulb and suggest that mitral and tufted cells participate in different synaptic circuits controlled by distinct GABA(A) receptor subtypes.     

The value of an operating microscope in peripheral nerve repair

Summary. The aim of this study was to test the hypothesis that the use of an operating microscope improves the results of peripheral nerve repair. Tibial nerve grafting was carried out on 48 Fischer rats divided into 2 groups: in one, a loupe was used, and in the other a surgical microscope. At 5 months after grafting, recovery was evaluated by functional, electromyographic, and morphometric tests. The mean motor nerve conduction velocity was 26.77±9.37 m/sec in the group where the loupe was used compared with 44.19±11.36 m/s when the microscope group was used. The soleus muscle weight and the diameter of myelinated fibres also confirmed better regeneration in the microscope group. These results clearly indicate that it is essential to use the microscope for peripheral nerve repair.

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Résumé. Le but de l’étude est de faire tester l’hypothèse que l’aide du microscope améliore les résultats de la chirurgie du nerf périphérique. La greffe du nerf tibial a été pratiquée sur 48 rats Fischer, repartis en deux groupes, l’un avec l’aide de la loupe et l’autre avec l’aide du microscope. Cinq mois après la greffe les résultats ont été soumis à une évaluation fonctionnelle, électromyographique et morphométrique. Les moyennes de la vitesse de la transmission motrice du nerf dans le groupe assisté par la loupe et celui assisté par le microscope étaient 26.77±9.37 m/s et 44.19±11.36 m/s respectivement. L’équivalent du test clinique, le poids du muscle soleus ainsi que les mésures du diamètre des fibres myelinisées ont aussi démontré une meilleure régénération, dans le groupe assisté par microscope. Ces resultats montrent clairement que l’aide du microscope est essentielle pour la réfection du nerf périphérique.

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Accepted: 20 June 1997     

Identification of trimoprostil metabolites excreted in rat bile formed by oxidation and taurine conjugation

14C-Trimoprostil was administered iv and orally to male rats. Radioactivity was excreted mainly via the feces after both routes of drug administration. Bile duct-cannulated rats excreted an average of 76% of an iv dose in the bile within 6 hr after dosing. Four biliary metabolites were isolated by HPLC and identified by proton NMR spectroscopy and mass spectrometry. These metabolites were taurine conjugates of: trimoprostil (approximately 11% of dose), 5,6-dihydro-2,3-dinor trimoprostil (approximately 5% of dose), 3,4-dehydro trimoprostil (less than 5% of dose) and 5,6-dihydro-2,3,4,5-tetranor trimoprostil (less than 5% of dose).     

Bladder reconstruction after cystectomy: use of ileocecal segment and three-loop ileal reservoir

We report on 11 patients who in 1980-1982 had bladder reconstruction, after cystectomy for bladder cancer, utilizing the ileocecal valve as an antireflux mechanism and a direct urethrocecal anastomosis. They received preoperative irradiation (2,000 rad) and had some early complications such as pelvic abscesses and temporary urinary fistulas. We have since omitted preoperative radiation on cases performed in 1984-1987 and they did not have these complications.     

柱切换HPLC法研究米托蒽醌毫微粒冻干静脉注射剂的药代动力学

建立了血浆中米托蒽醌的柱切换高效液相色谱测定法,测定和比较了米托蒽醌溶液型注射剂和毫微粒冻干静脉注射剂在家兔体内的血药曲线,并研究比较了二者的药代动力学参数。米托恩醌毫微粒冻干注射剂使米托蒽醌在血中浓度大为降低,血中分布容积增大了近5倍,体内平均驻留时间延长了2倍多。表明米托蒽醌毫微粒有明显的体内长效作用,结合其体内分布试验研究结果,表明其具有明显肝靶向分布作用。     

Prazosin depression of baroreflex function in hypertensive man

Summary Prazosin is a post synaptic alpha adrenergic blocker effective in hypertension, whose hypotensive effect is unaccompanied by reflex tachycardia or hyperreninemia, nor by other evidence of increased sympathetic activity. We studied the baroreceptor reflex arc as a potential mediator of these effects. Twenty-two essential hypertensive men were treated with prazosin alone versus placebo, and experienced a blood pressure fall (from 114.8±3.6 down to 101.1±2.5 mm Hg,p<0.005) unaccompanied by any change in heart rate, plasma renin activity, or several other indices of sympathetic nervous system activity (plasma dopamine-β-hydroxylase activity; urinary excretion of free catecholamines and vanillyl mandelic acid; allp>0.1). Concomitant with the blood pressure fall, there was a significant depression of baroreflex arc sensitivity, from 11.4±2.0 ms/mmHg down to 6.6±1.9 ms/mmHg (p<0.05), without an associated change in cardiac vagal inhibition (291.2±46.2 versus 300.3±19.2 ms,p>0.1). Baroreflex arc sensitivity depression may in part explain the lack of reflex sympathetic outflow noted during prazosin treatment of hypertension.     

3,5-Diphenyl-1H-pyrazole derivatives. II--N-substituted 1-(2-aminoethyl)-3,5-diphenyl-1H-pyrazoles and their 4-bromo derivatives with analgesic and other activities

The synthesis of N-substituted 1-(2-aminoethyl)-3,5-diphenyl-1H-pyrazoles and their 4-bromo derivatives (V) by reaction of primary and secondary amines with the tosylates of 1-(2-hydroxyethyl)-3,5-diphenyl-1H-pyrazole and its 4-bromo derivative is described. Some of compounds (V) showed a remarkable analgesic activity in mice. Moreover, the above compounds usually exhibited moderate hypotensive, bradycardiac and antiinflammatory activities in rats, infiltration anesthesia in mice, as well as a weak platelet antiaggregating activity in vitro.