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.     

Primary study of iontophoresis of zinc ion in treatment of retinitis pigmentosa

We report here the preliminary effects of zinc iontophoresis in treatment of 26 Rp patients who had decreased zinc serum level or abnormal ratio of serum copper to zinc. Through more than 20 to 30 times of therapy, the vision of 15.38% eyes increased more than "3 lines", 4% eyes increased more than 5 degrees in the visual field, 13.46% eyes improved in dark adaptation threshold (greater than 1.0), the visual functions of the rest eyes were slightly improved or unimproved. The fundus didn't change before & after treatment. There were no changes of ERG in 8 eyes of 4 cases. In addition, the advantages and disadvantages between Zn iontophoresis and Zn compound taken orally, the improvement of vision by direct electric current therapy, the relationship between the metabolism of Zn element and Vit A and influence of Zn over the mechanism of dark adaptation were also briefly discussed.     

Reactive Airways Dysfunction Syndrome (RADS) due to chlorine gas exposure

Reactive Airways Dysfunction Syndrome (RADS) has been described following exposure to various irritant gases⁽¹⁾. We describe a case of RADS occurring following exposure to chlorine gas and which has persisted at 6 years follow-up.     

Debrisoquine hydroxylation and sulfamethazine acetylation in a Chinese population

Both debrisoquine hydroxylation and sulfamethazine acetylation phenotypes were studied in the same native Chinese population. Debrisoquine hydroxylation status was determined by HPLC assay of debrisoquine metabolic ratio in urine after a single oral dose of 10 mg debrisoquine. Three poor metabolizers were found in 220 subjects (1.36%). One hundred and one subjects of this population previously debrisoquine phenotyped were also tested for acetylation phenotyping on a separate occasion. Their acetylation status were determined by HPLC assay of "% acetylation" after a single oral dose of 1 g sulfamethazine. Twenty (19.8%) slow acetylators were found. There were no significant association between the 2 metabolic pathways.