AIM: To further investigate the immunologic mechanism of myasthenia gravis(MG). METHODS: Acetylcholine receptor antibodies(AchRab) and presynaptic membrane antibodies (PsMab) was determined by ELISA in 285 cases of MG patients. Tumor necrosis factor- alpha(TNF-?) and RBC-C3b receptor rosette rate(RBC-C3bRR)and RBC-IC rosette rate (RBC-ICR)was determined in 202 patients with MG. Furthermore, the peripheral blood lymphocyte subsets was examined in 104 cases MG patients. RESULTS: The positive rates of the AchRab and PsMab in MG were very significantly higher than that of control.The positive rate of PsMab in patients with negative AchRab was very significantly higher than that of patients with the positive AchRab.In 202 MG patients, the TNF-? was significantly higher, but the RBC-C3bRR was significantly lower than those of control, while the RBC-ICR has no significant change. CONCLUSION: MG is an autoimmune disease with damaged postsynaptic membrane by the AchRab, and some patients with both the AchRab and PsMab could manifest disfunction in the postsynaptic and presynaptic membrane. While the patients who just has the PsMab maybe damaged only in the presynaptic membrane. Other body fluid immune or/and cell immune mechanism may be involved in MG patients without AchRab and PsMab. [

Objective:To compare and analyze the differences in the measurement of intra-abdominal pressure in different positions of critically ill patients treated with extracorporeal membrane oxygenation (ECMO) combined with prone position integration, with a view to finding a more optimal intra-abdominal pressure monitoring strategy, which can provide a theoretical basis for clinical diagnosis and treatment.Methods:Forty critically ill patients who underwent ECMO combined with prone position integrated treatment in the department of Intensive Care Medicine of the First Affiliated Hospital of Guangxi Medical University from January 2020 to June 2023 were selected by convenience sampling method using an own-control trial. The differences in intra-abdominal pressure between supine position with head elevated at 0°, 15°and 30°and prone position with head high and foot low slopes at 0°, 15°and 30°were compared and analyzed. Heart rate, respiration, mean arterial pressure and oxygen saturation were also compared in patients in different positions.Results:There were 29 males and 11 females in 40 patients with the age of (62.58 ± 17.99) years.The intra-abdominal pressure in supine position with head elevated at 30° was (12.45 ± 3.43) mmHg(1 mmHg=0.133 kPa), which was higher than that of 0° and 15° of (9.38 ± 2.52) and (10.70 ± 2.95) mmHg, and the differences were statistically significant ( t=4.56, 2.45, both P<0.05);the difference in intra-abdominal pressure between 0° and 15° was not statistically significant ( P>0.05); the intra-abdominal pressure in prone position with head-high-foot-low slope of 30° was (12.92 ± 4.19) mmHg, which was higher than that of 0°and 15°of (9.67 ± 2.80), and (11.01 ± 3.10) mmHg, and the differences were statistically significant ( t=4.08, 2.32, both P<0.05); the difference in intra-abdominal pressure between 0° and 15° was not statistically significant ( P>0.05).The differences in intra-abdominal pressure between groups of supine bed head elevation 0°, 15°, 30°and prone position with head high and foot low slopes 0°, 15°, 30°were not statistically significant (all P>0.05). The differences in heart rate, respiration, mean arterial pressure and oxygen saturation in the supine position with head elevated at 0°, 15°and 30° were not statistically significant when compared within groups (all P>0.05); the differences in heart rate, respiration, mean arterial pressure and oxygen saturation in the prone position with head elevated with feet and feet on low slopes at 0°, 15°and 30°were not statistically significant when compared within groups (all P>0.05); and the differences in supine position with head elevated at 0°, 15°, 30°and prone head-height-foot-low slope 0°, 15°, 30°of heart rate, respiration, mean arterial pressure were not statistically significant (all P>0.05); supine bed head elevation 0°, 15°, 30°and prone head-height-foot-low slope 0°, 15°, 30°of oxygen saturation between the groups, the differences were statistically significant ( Z=6.85, 6.82, 6.68, all P<0.05). Conclusions:Intra-abdominal pressure can be measured in the 15° prone position in critically ill patients treated with ECMO combined with prone position integration; the different positions have little effect on vital signs, but the prone position significantly improves oxygen saturation.