Degradation products of different water content sevoflurane in carbon dioxide absorbents by gas chromatography-mass spectrometry analysis / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Sevoflurane is currently used as a volatile inhalation anesthetic with many clinical advantages. A representative degradation product, compound A, was quantitatively measured to investigate whether there are different reactions between two kinds of water content sevoflurane formulations with different carbon dioxide (CO2) absorbents.</p><p><b>METHODS</b>A closed-circle breathe bag with the Dräger Fabius GS anesthesia apparatus was used as an artificial rubber lung. The experiments were grouped according to different sevoflurane formulations: group A: higher-water sevoflurane (Ultane); group B: lower-water sevoflurane (Sevoness). During the experiment, CO2 (200 ml/min) was continually perfused to keep the end-tidal pressure of CO2 (P(ET)CO2) at 35 - 45 mmHg. The artificial ventilation was set to 6 L/min, and the breathing rate at 12 breaths/min. The circuit was operated with constant fresh gas flow rate (1 L/min) and the sevoflurane concentration was kept at 1.0 minimum alveolar concentration (MAC) for 240 minutes. At 0, 10, 20, 30, 60, 90, 120, 180 and 240 minutes, gas was collected from the Y-piece. Gas chromatography/mass spectrometry (GC/MS) was used to quantify the major degradation product, compound A, with different water content sevoflurane. PETCO2 and sevoflurane concentration, and the temperature of the canister were continuously monitored during the experiment.</p><p><b>RESULTS</b>There were no significant differences in P(ET)CO2 and sevoflurane concentrations between the two groups. Drägersorb 800 plus produced the highest concentrations of compound A compared with other sodalimes, and Sevoness in Drägersorb 800 plus generated more compound A than Ultane (P < 0.05). There were significant differences in the peak and average compound A concentrations between Ultane and Sevoness with Drägersorb 800 plus (P < 0.05), while the compound A concentration produced by Sodasorb grase and sofonolime in the two groups showed no significant difference (P > 0.05). In the same group, the peak and average of compound A concentration produced by Sodasorb grase and sofonolime showed significant difference with Drägersorb 800 plus (P < 0.05).</p><p><b>CONCLUSION</b>The water content of sevoflurane and potassium hydroxide in CO2 absorbent can influence compound A production.</p>

A comparison between vital capacity induction and tidal breathing induction techniques for the induction of anesthesia and compound A production / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Vital capacity induction and tidal breathing induction are currently administered for inhalation induction of anesthesia with sevoflurane. The aim of this study was to compare them using sevoflurane with respect to induction time, complications of inhalation induction, and compound A production in adult patients.</p><p><b>METHODS</b>Fifty-one women with American Society of Anesthesiologists physical status I-II undergoing mammary gland tumorectomy were randomly assigned to receive either vital capacity induction or tidal breathing induction with 8% sevoflurane at 6 L/min followed by laryngeal mask airway insertion. Induction times, complications of inhalation induction, and vital signs were recorded. Inspired concentrations of compound A were assayed and sofnolime temperatures were monitored at one-minute intervals after sevoflurane administration.</p><p><b>RESULTS</b>The time to loss of eyelash reflex was significantly shorter with the vital capacity induction technique than with the tidal breathing induction technique ((43.8 ± 13.4) seconds vs. (70.8 ± 16.4) seconds, respectively; P < 0.01). Cardiovascular stability was similar in both groups. The incidence of complications was significantly less with the vital capacity induction technique than with the tidal breathing induction technique (7.7% vs. 32%, respectively; P < 0.01). However, the mean and maximum concentrations of compound A during induction were significantly higher in the vital capacity group than those in the tidal breathing group (P < 0.05); compound A concentration at the beginning of anesthesia maintenance was (40.73 ± 10.83) ppm in the vital capacity group and (29.45 ± 7.51) ppm in tidal breathing group (P = 0.019).</p><p><b>CONCLUSION</b>For inhalation induction of anesthesia, the vital capacity induction was faster and produced fewer complications than that for tidal breathing induction, but increased compound A production in the circuit system.</p>

A study of oral colonization of mutans streptococci and feeding habits in infants / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To study the correlation of prime colonization time of Mutans Streptococci and feeding habits in infants.</p><p><b>METHODS</b>One hundred and eighty children (aged 6-24 months) from Shenyang city were examined for the colonization of MS Related items were registered by completed questionnaires.</p><p><b>RESULTS</b>The study showed a correlation between prime colonization time and feeding mode, breast feeding, feeding frequency during bedtime, asleep habits.</p><p><b>CONCLUSION</b>Advocating reasonable feeding mode and asleep habits is effective to interdict or delay MS's colonization and transmission in child to prevent caries.</p>

Expression of basic fibroblast growth factor in dental pulp during root development of permanent teeth / 华西口腔医学杂志

<p><b>OBJECTIVE</b>The purpose of this study was to investigate the changes of basic fibroblast growth factor (bFGF) expressed in normal human dental pulp at different root development stages of permanent teeth.</p><p><b>METHODS</b>Based on the teeth root development status, the pulp tissues were classified into three groups: root just starting development, being in development and apical closed. The pulps were immunohistochemically examined by use of bFGF antibody.</p><p><b>RESULTS</b>Staining was strongly positive in immature permanent teeth, especially at the stage of root just starting development. Image analysis indicated that the gray values of positive reaction in three groups were statistically different (P < 0.001). For the first group, the gray value of the outer pulp was higher than that of the pulp core. For the second group, the pulp core has a higher gray value in the coronal pulp, while a lower value in root pulp compared to the outer pulp.</p><p><b>CONCLUSION</b>With the development of root formation, the expression of bFGF in dental pulp shows different characteristics. bFGF may play a role in dental pulp development and maturation.</p>