Scanning electron microscopic observations on larvae and young adults of Angiostrongylus cantonensis

Scanning electron microscopic observations on the structure of the body surface of various larval stages and young adults of Angiostrongylus cantonensis were made. The mouth opening of the first and second stage larvae closes in "Y" form until well developed young adult stage. There are two rows of 6 sensory papillae each around the mouth. With development of the worm, the papillae of the outer row gradually degenerated and could hardly be seen in adult worms. A pair of amphidial pores was present on the external side of lateral papillae of the inner row, being conspicuous in the fourth-stage larvae. There was one excretory pore on the ventral side of the anterior end. The copulatory bursa of the male worms began to develop in the third stage larvae and became well developed in the 25-day young adults. The processes of the development of copulatory bursa were described. The gonopore could be seen in the female worm as early as in the first-stage larvae but the anal pore appeared only in the fourth-stage larvae, both of them did not develop completely until the young adult stage of 11 day old (Figs. 1-18).     

Inhibition of two imidazole antimycotics, eberconazole and clotrimazole, by different components of Candida albicans serotype B membrane protoplasts

The inhibitory activity of different components from Candida albicans membrane protoplasts against clotrimazole and eberconazole was studied. The phospholipid fraction had the most inhibitory activity and the antimycotic activity of eberconazole was more affected than that of clotrimazole.     

Behavioral sensitization to MK-801 (dizocilpine): neurochemical and electrophysiological correlates in the mesoaccumbens dopamine system

MK-801, a non-competitive antagonist at the N-methyl-D-aspartate (NMDA) subtype of central glutamate receptor, stimulates locomotor activity in rats. Administration of MK-801 (0.25mg/kg, i.p.) on four consecutive days results in progressive sensitization of its locomotor stimulatory effects. Because of the importance of dopamine (DA) systems in locomotor sensitization to other stimulants (e.g. amphetamine and cocaine), we examined the possible role of DA transmission in MK-801 sensitization. The D1 antagonist SCH 23390 was used for these experiments because of the well-established ability of D1 antagonists to block both D1- and D2-mediated unconditioned behaviors. Acute behavioral effects of MK-801 were reduced by SCH 23390 only at doses that decreased basal activity, while the expression of MK-801 sensitization was attenuated by SCH 23390 in some experiments but never completely prevented. Co-administration of SCH 23390 with MK-801 on pretreatment days did not prevent the development of sensitization. In vivo microdialysis experiments compared the effect of MK-801 on extracellular DA levels in the nucleus accumbens (NAc) on Days 1 and 4 of repeated administration. On Day 1, MK-801 produced a modest elevation of DA levels. On Day 4, only 6/17 rats in microdialysis experiments expressed sensitization; these rats, however, exhibited a more rapid rise in DA levels than Day 1 rats or non-sensitized Day 4 rats. Electrophysiological studies revealed that repeated MK-801 administration resulted in supersensitivity of D1 receptors on NAc neurons. Thus, behavioral studies support the importance of non-dopaminergic mechanisms in MK-801 sensitization, while neurochemical and electrophysiological studies suggest that MK-801 sensitization is accompanied by changes in DA transmission in the NAc similar to those observed in amphetamine- or cocaine-sensitized rats.     

Involvement of antioxidant enzymes in multiple-drug resistance in a human T-lymphoblastic leukemia-cell line which over-expresses p-glycoprotein

We have compared the specific activities of Cu/Zn superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) in a vinblastine sensitive human T-lymphoblastic cell line (CCRF-CEM) and its multiple drug resistant (MDR) counterpart cell line (CEM/VLB100), which over-expresses P-glycoprotein (PGP). We have found that the specific activity Cu/Zn SOD was consistently 38% increased in CEM/VLB100 cells compared with CCRF-CEM cells. In contrast, the activities of CAT and GSH-Px were similar in the two cell lines. These results suggest that MDR in CEM/VLB100 is a complicated phenotype which not only involves a PGP mechanism, but also a SOD protection mechanism against drug-mediated O2.- cytotoxicity.     

La prothèse à pivot "GSB"

Résumé L'étude porte sur une série de 50 prothèses totales de genou GSB implantées entre 1981 et 1988 au Centre de Traumatologie et d'Orthopédie de Strasbourg. Cette prothèse entre dans la catégorie des prothèses à charnières cimentées, mais son pivot semi rigide diminue efficacement les contraintes exercées sur le ciment. Les résultats sont conformes à ceux retrouvés dans la littérature concernant les prothèses à charnière. L'accent a été mis plus particulièrement sur les complications spécifiques à ce type d'arthroplastie : infections, fractures, complications rotuliennes. Cependant le caractère semi rigide de la GSB a permis la disparition presque totale des descellements qui compliquaient d'ordinaire les prothèses à charnière. La prothèse GSB nous semble donc supérieure aux autres modèles de prothèse à charnière.     

偶联剂CGE（N）—R型处理前后牙本质的表面状态及其...

In order to research the states of dentine surface and dentine surface primed with coupling agent, we used microscope, transmission electron microscope (TEM) and solid fluorescence method. Observed under microscope, patterning of dentinal tubules and their poles was very explicit; through the view of interface between coupling agent adsorbed and human dentine powder by TEM, it was revealed that the coupling agent was adsorbed onto the dentine surface as if it "grew out" of the dentine surface; through examination of interface between the coupling agent adsorbed and dentine surface by fluorescence spectrum, which differed from that of the coupling agent or dentine surface, i.e., this fluorescence spectrum of interface changed obviously (red shift). This phenomenon indicated that there was a chemical reaction occurring between tooth surface and adsorbed coupling agent. Therefore we can conclude that the three examinations are necessary to provide the argument for establishment of chemical bonding mechanism between dentine and coupling agent.     

Changes of blood humoral substances in experimental cirrhosis and their effects on portal hemodynamics

The changes of humoral substances in the blood of cirrhotic rats were studied together with their effects on portal hemodynamics at different stages during the development of cirrhosis. The profiles of humoral substances and hemodynamics in two different cirrhotic rat models were also investigated. During the development of cirrhosis, glucagon increased markedly in all stages, histamine and vasoactive intestinal polypeptide (VIP) increased in the early stage, serotonin (5-HT) and somatostatin (SS) increased in the middle and late stages. There were different patterns of humoral substances in different cirrhotic models. Glucagon was the main humoral substance elevated in CCL4 induced cirrhosis, but histamine and 5-HT were mainly elevated in the blood in thioacetamide (TAA) induced cirrhosis. The hemodynamics altered differently in different stages during the development of cirrhosis and differently in the two cirrhotic rat models. Exchange transfusions between normal and cirrhotic rats resulted in an elevation of portal flow in normal rats, but no such changes were found after exchange pressure and an increase of portal blood transfusions between normal rats. The relationship between the humoral substances and portal hemodynamics is discussed. The results of this study strongly support the hypothesis of "humoral mechanism" in the pathogenesis of portal hypertension due to cirrhosis.

     

Saccadic suppression of displacement: influence of postsaccadic exposure duration and of saccadic stimulus elimination

The threshold for detection of stimulus displacement, which is normally raised in the presence of voluntary saccades relative to its value during steady fixation ("saccadic suppression of displacement"), decreases from 50x to 25x its value during steady fixation when the duration of the second display is experimentally increased from 33 to 461 msec; further increase of the duration of the second display has no additional effect. It might be expected that this improvement in sensitivity to displacement is a consequence of the elimination from perception of the visible smear corresponding to the saccadic stimulus by the action of metacontrast from the postsaccadic stimulus. That this is not so is shown by the fact that the improvement in displacement sensitivity with increased postsaccadic exposure duration is unaffected by experimental elimination of the retinal stimulus normally present during the saccade, even under conditions for which the saccadic stimulus is normally visible and appears smeared. The results demonstrate that the basis for saccadic suppression of displacement lies in the transient saccade-related modification of extraretinal eye position information.