Objective To study atrioventricular conduction during right coronary artery infarction and its correlation with sympathetic nerve.Method AIMI model by ligating the fight coronary artery of denervated autonomic nervous cats was used.The A,H and V-wave were measured from the His electrode by template matching.The AA,AH,HV intervals with and without sympathetic nerve stimulation were measured respectivelv.Results The decreased percentage of AH intervals was (7±5)% vs.(14±5)% (without pacing) and (12±2)% vs.(23±7)% (with pacing) respectively in ischemia and normal after sympathetic nerve stimulation,and the decreasing amplitude were 50% and 48% respectively.Conclusion The regulating function of sympathetic nerve on atrioventricular conduction decreased after ischemia related to the right coronary artery.This decrease may be one of the mechanisms that lead to atrioventficular block after acute inferior myocardial infarction.

Objective To investigate the expression of IL-8 and CXCR2 on keratinocytes from psoriatic lesions and their roles on clinical and pathologic manifestations. Methods The chemotaxis of psoriatic lesional keratinocytes was detected by micropore loculus test. The concentration of IL-8 was determined in the cultured supernatants of psoriatic keratinocytes by ELISA. The expression of CXCR2 on keratinocytes from affected skin was tested by flow cytometry. Results The chemotaxis for neutrophils by the cultured supernatants of psoriatic lesional keratinocytes was significantly stronger than that by controls. The concentration of IL-8 in the cultured supernatants of psoriatic lesional keratinocytes was also increased. The expression of CXCR2 on psoriatic keratinocytes was significantly increased. Conclusions The psoriatic epidermal hyperproliferation may be correlated with up regulation of IL-8 production and CXCR2 expression on psoriatic keratinocytes. At the same time, the psoriatic inflammation may be partly related to the increase of secretion of IL-8, which has chemotactic capacity, by keratinocytes. IL-8 and CXCR2 may be involved in the pathogenesis of psoriasis.

Objectives: To identify any craniofacial morphological changes induced by a mandibular-repositioning oral appliance (MRA) and to explore the possibility of predicting the treatment response to MRA by cephalometric analysis in patients with obstructive sleep apnea (OSA). Methods: Seventy OSA patients [male/female: 63/7; age: (50.5±11.6) years; BMI: (27.6±4.6) kg/m2; AI: (34.9±21.3) episodes/hour; and oxygen saturation nadir: (66.3±16.5) %] were enrolled. MRA was fabricated individually for each patient after the consultation by a dentist. Polysomnographic (PSG) examination was repeated with MRA in place 3 months after the initiation of the MRA therapy. For cephalometric analysis, a pair of cephalograms of each patient was obtained, one with and another without MRA. Results and Conclusions: After 3 months' treatment, AI was (156±19.2) episodes/hour, significantly reduced compared with the pre-treatment average AI (34.9±21.3 episodes/hour,P<0.000 1). Oxygen saturation nadir improved from (66.3±16.5)% (pre-treatment) to (74.1±15.5)% (with MRA) (P<0.001). A reduction of AI≥50% was achieved in 42 patients. Insertion of MRA led to anterior shift of the mandible, increase in upper airway width and area and decrease in upper airway length. Those with evident retrognathia and longer anterior upper facial height were more likely to benefit from the MRA management.

BACKGROUND: In patients with obstructive sleep apnea(OSA),the degree of severity of OSA is mostly related to the sleep time spent in the supine position. According to the apnea-hypopnea index(AHI), positional and n onpositional OSA has been distinguished.OBJECTIVE: To compare the clinical characteristics of positional and nonpositional OSA and investigatethe relationship between sleep position and respiratory function of patients with OSA.DESIGN: A comparative clinica] observation based on the OSA patients.SETTING: Center of Sleep Disorders,Nanjing General Hospital of Nanjing Military Area Command of Chinese PLA.PARTICIPANTS: From October 1998 to May 2002,225 patients were examined with overnight polysomnography in the Center of Sleep Disorders,Department of Respiratory Disease, Nanjing General Hospital of Nanjing Command. According to the inclusion criteria of ① AHI≥10 times/hour;② Sleep time in supine and lateral positions≥30 minutes; ③ Over 20years of age; 225 patients were selected from the total of 415 consecutive patients,including 63 with positional and 162 with nonpositional OSA.METHODS: All patients received overnight monitoring with HMS-5500polysomnography system(Respironics Inc USA) in the sleep laboratory. Queries for a detailed case history and physical examination were performed with the pulmonary functions evaluated with body p lethysmography. The clinical data and results of polysomnographic and pulmonary function tests were compared between the two groups of patients and a multiple stepwise regression analysis was employed to evaluate the determinant factors for sleep position dependence of the patients' condition.MAIN OUTCOME MEASURES: Main outcome: Comparisons of the clinical data,polysomnographic result and pulmonary function between the two groups. Secondary outcome: Correlation between classification of OSA and the clinical data.RESULTS: Totally 63 (28%) of the 225 OSA patients were identified as the positional type,who had significantly greater body mass index (BMI)then the nonpositional type patients [(43.46 ± 16.43) kg/m2 vs (23.90 ± 12.36) kg/m2,t =3. 977,P<0.01]. Except for sleeping time in lateral and supine positions, minimal SatO2 and basic SatO2 before the matching for BMI,all the other factors in polysomnograms of the two groups were significant different(P<0.05 or P<0.01). After BMI matching,all the measurements were identical to those recorded for the primary grouping with the exception of nocturnal limb movement frequency,which differed but insignificant between the two groups. The pulmonary function in the two groups was no significant difference(P>0.05) . Multiple stepwise regression analysis indicated that AHI and BMI were the two determinant factors for positional dependence of OSA with a predictive power of 26. 2%. Linear correlation analysis showed correlation of AHI and SatO2 with BMI in the whole group and nonpositional group(P<0.05 or P<0.01),but not in the positional group (P>0.05).CONCLUSION: About one-third of the OSA patients shows sleep position dependence,who may respond favorably to sleep position training. Sufficient patency can be retained in the upper airway of these patients to relieve respiratory obstruction during sleep and improve the respiratory function.