OBJECTIVETo compare the pharmacokinetic parameters of pyridostigmine bromide dispersible tablets and common tablets in rabbits.

METHODSTwelve rabbits were given an oral dose (60 mg) of pyridostigmine bromide dispersible tablets or common tablets in a randomized crossover study. The plasma concentration of pyridostigmine bromide was determined by reversed-phase ion pair chromatography. The pharmacokinetic parameters were calculated using DAS2.1.1 software.

RESULTSThe pharmacokinetic parameters showed no significant differences in rabbit plasma between pyridostigmine bromide dispersible tablets and common tablets. The two tablets had a C(max) of 1.83∓0.08 mg·L(-1) and 1.68∓0.03 mg·L(-1), tmax of 2.33∓0.41 h and 2.58∓0.20 h, AUC(0-24) of 15.50∓0.62 mg·h·L(-1) and 15.14∓0.30 mg·h·L(-1), AUC(0-∞) of 15.82∓0.70 mg·h·L(-1) and 15.57∓0.32 mg·h·L(-1), respectively. The relative bioavailability F(0-24) was 102.38% and F(0-∞) was 101.61% for the dispersible tablets.

CONCLUSIONThe two tablets are bioequivalent in rabbits.

Administration, Oral ; Animals ; Biological Availability ; Female ; Male ; Pyridostigmine Bromide ; administration & dosage ; blood ; pharmacokinetics ; Rabbits ; Tablets ; Therapeutic Equivalency

BACKGROUNDThymectomy is considered the most effective treatment in patients with myasthenia gravis. This study aimed to explore the predictors of postoperative myasthenic crisis in patients with myasthenia gravis after thymectomy.

METHODSClinical records of 243 patients with myasthenia gravis who underwent thymectomy were reviewed retrospectively. The following factors were analyzed in relation to the occurrence of myasthenic crisis after thymectomy: gender, age, duration of symptoms, Osserman stage, history of myasthenic crisis, concomitant diseases, preoperative pyridostigmine dose, preoperative steroid therapy, operation approach, operation time, presence of thymoma, major postoperative complications.

RESULTSForty-four patients experienced postoperative myasthenic crisis during the first month after thymectomy. Univariate analysis revealed that Osserman stage (RR = 0.0976, P = 0.000), history of myasthenic crisis (RR = 0.2309, P = 0.012), preoperative pyridostigmine dose (RR = 0.4349, P = 0.016), thymoma (RR = 0.0606, P = 0.000), and major postoperative complications (RR = 0.1094, P = 0.000) were significantly related to postoperative myasthenic crisis. Multivariate Logistic regression analysis showed that Osserman stage (IIb + III + IV) (RR = 0.0953, P = 0.000), thymoma (RR = 0.0294, P = 0.000), and major postoperative complications (RR = 0.0424, P = 0.000) independently predict postoperative myasthenic crisis.

CONCLUSIONOsserman stage (IIb + IIIb + IV), thymoma and major postoperative complications are independent predictors of postoperative myasthenic crisis in patients with myasthenia gravis who underwent thymectomy.

Adolescent ; Adult ; Aged ; Child ; Female ; Humans ; Male ; Middle Aged ; Myasthenia Gravis ; surgery ; Postoperative Complications ; Thymectomy ; adverse effects ; Treatment Outcome ; Young Adult

The purpose of this study was to investigate the effects of granulocyte-macrophage colony stimulating factor (GM-CSF) on the growth of mouse bone marrow endothelial cells. Endothelial cell culture medium (Endo-M) was used to culture murine bone marrow endothelial cells. Endothelial cell colonies were counted under microscope by Wright-Giemsa staining. The effect of different concentration of GM-CSF on the proliferation of bone marrow endothelial cells was observed by the formation of endothelial cell colonies, MTT and flow cytometry. The results indicated that the endothelial specific marker vWF was expressed by the colony cells, GM-CSF promoted the proliferation of bone marrow endothelial cell colonies and MTT confirmed the effect of GM-CSF on promoting the proliferation of bone marrow endothelial cells. The result of detecting cell cycle showed that the rate of cells entering into S phase was 9.3% in GM-CSF added group and the rate of cells entering into S phase was 2.1% in control. There was no significant difference in cell growth curve between the first passage and fourth passage. It is concluded that GM-CSF can promote the proliferation of bone marrow endothelial cells, the proliferation potential of bone marrow endothelial cells between the first and fourth passage no significantly changes.
Animals ; Bone Marrow Cells ; cytology ; Cell Cycle ; drug effects ; Cell Proliferation ; drug effects ; Cells, Cultured ; Endothelial Cells ; cytology ; Female ; Granulocyte-Macrophage Colony-Stimulating Factor ; pharmacology ; Male ; Mice

OBJECTIVETo develop a coated electrode of immobilized denitrificants and to evaluate the performance of a bioelectrochemical reactor to enhance and control denitrification.

METHODSDenitrifying bacteria were developed by batch incubation and immobilized with polyvinyl alcohol (PVA) on the surface of activated carbon fiber (ACF) to make a coated electrode. Then the coated electrode (cathode) and graphite electrode (anode) were transferred to the reactor to reduce nitrate.

RESULTSAfter acclimated to the mixtrophic and autotrophic denitrification stages, the denitrifying bacteria could use hydrogen as an electron donor to reduce nitrate. When the initial nitrate concentration was 30.2 mg NO3- -N / L, the denitrification efficiency was 57.3% at an applied electric current of 15 mA and a hydraulic retention time (HRT) of 12 hours. Correspondingly, the current density was 0.083 mA/cm2. The nitrate removal rate of the reactor was 34.4 g NO3- -N/m3 x d, and the surface area loading was 1.34 g NO3- -N / m2 x d.

CONCLUSIONThe coated electrode may keep high quantity of biomass, thus achieving a high denitrification rate. Denitrification efficiencies are related to HRT, current density, oxidation reduction potential (ORP), dissolved oxygen (DO), pH value, and temperature.

Adsorption ; Bacteria ; metabolism ; Biodegradation, Environmental ; Bioreactors ; Carbon ; chemistry ; Electrodes ; Electrolysis ; Nitrates ; metabolism ; Oxidation-Reduction ; Oxygen ; Polyvinyl Alcohol ; Temperature ; Time Factors ; Water Pollutants, Chemical ; metabolism ; Water Purification ; methods

OBJECTIVETo establish an high-performance liquid chromatography (HPLC)-based method for analysis of the pharmacokinetics and relative bioavailability of dextromethorphan chewing gum tablets in rabbits.

METHODSThe pharmacokinetic parameters and the relative bioavailability of dextromethorphan chewing gum preparation in rabbits were compared with those of the commercially available chewing dextromethorphan tablets using 3P97 software.

RESULTSPharmacokinetic analysis of the new dextromethorphan chewing gum tablets showed a AUC of 488.76 ∓ 175.00 ng.ml(-1).h, C(max) of 95.45 ∓ 17.53 ng/ml, and t(max) of 1.83 ∓ 0.57 h as compared with the corresponding parameters of 370.13 ∓ 90.56 ng.ml(-1).h, 174.00 ∓ 47.88 ng.ml, and 1.04 ∓ 0.14 h for the commercially available chewing tablets. The relative bioavailability of the new chewing gum medicine system was (140.73 ∓ 65.91)%.

CONCLUSIONThe new dextromethorphan chewing gum preparation shows an increased AUC((0→)), decreased C(max), and prolonged t(max) in comparison with the commercially available chewing tablets, with also a greatly enhanced relative bioavailability.

Animals ; Biological Availability ; Chewing Gum ; Chromatography, High Pressure Liquid ; Dextromethorphan ; administration & dosage ; blood ; pharmacokinetics ; Drug Delivery Systems ; Rabbits

OBJECTIVETo evaluate the feasibility and curative effect of thymectomy for myasthenia gravis (MG) by video-assisted thoracoscopic surgery (VATS) through right anterior-lateral approach.

METHODSFifty-six patients of MG were treated with thoracoscopic thymectomy and mediastinal fat dissection through right anterior-lateral approach from August 2001 to October 2007. The feasibility, safety, complication and remission for MG were retrospectively analyzed.

RESULTSFifty-five operations were completed by VATS. The mean operative time and blood loss were (96.2 +/- 52.1) min and (68.7 +/- 21.4) ml, respectively. The brachiocephalic vein injury by the electric coagulator occurred in two cases and one of them performed thoracotomy for homeostasis, the other performed ligation. The postoperative pathology showed hyperplasia in 38 cases, atrophy in 5 cases, thymoma in 12 cases and cyst of thymus in 1 case. And the operative complication included one myasthenia crisis (1.8%) at the third day and one death (1.8%) at the eighth day because of postoperative hemorrhage. The average length of stay was (7.9 +/- 2.9) d. All cases were followed up from one to seventy months. Eight (14.3%) of complete remission, 39 cases (69.6%) of partial remission and 7 cases (12.5%) of no change were found. The total effective rate was 83.9%.

CONCLUSIONSThoracoscopic thymectomy through right anterior lateral approach is technically feasible, safe and minimally invasive. It has a high remission rate for MG.

Adolescent ; Adult ; Aged ; Child ; Feasibility Studies ; Female ; Follow-Up Studies ; Humans ; Male ; Middle Aged ; Myasthenia Gravis ; surgery ; Retrospective Studies ; Thoracic Surgery, Video-Assisted ; Thymectomy ; methods ; Treatment Outcome