Association of neuroelectrophysiology and analysis of cerebrospinal fluid immunoglobulin with pathogenetic conditions of patients with Guillain-Barre syndrome

BACKGROUND： Guillain-Barre syndrome （GBS） is an autoimmune disease which is characterized by demyelination of peripheral nerve and nerve root, and inflammatory reaction of lymphocyte and macrophage. Neuroelectrophysiological examination and cerebrospinal fluid （CSF） analysis are of significance for its diagnosis. OBJECTIVE： To study the association of neuroelectrophysiology and cerebrospinal fluid immunoglobulin （CSF-lg） with pathogenetic conditions of patients with GBS. DESIGN： Case control study SETTING： Department of Neurology, Shenzhen Municipal Shekou Group Hospital; Department of Neuroelectrophysiology, People＇s Hospital of Guangdong Province. PARTICIPANTS： A total of 32 GBS patients including 18 males and 14 females who aged from 17 to 72 years were selected as experimental group from the Department of Neurology, People＇s Hospital of Guang- dong Province from January 2004 to December 2005. All cases conformed with GBS diagnostic criteria established by Asbury in 1990 and they were divided into three types according to neurological criteria established by Chinese Neurology and Psychology Journal in 1993： mild, moderate and severe types. Another 30 patients with vascular headache were selected as control group from the same hospital including 14 males and 16 females who aged from 17 to 79 years. METHODS： ① Neuroelectrophysiological examination： Multiple-functional electromyography device provided by Nicolet Company, USA was used to measure nerve conduction velocity （NCV）, including motor nerve conduction velocity （MCV） and sensory nerve conduction velocity （SCV）; meanwhile, electromyologram （EMG）, somatosensory evoked potential （SEP） and electroencephalogram （EEG） were also measured. ② Detection of CSF-lg： Concentrations of IgG, IgA and IgM were measured with immunofixation electrophoresis. ③Follow-up： Among 32 GBS patients, 14 cases received follow-up after treatment and the longest fol- low-up time was 1 year after onset. Among them, 8 cases were reexaminined with neuroelectrophysiological and CSF examinations. MAIN OUTCOME MEASURES： Results of NCV, EMG, SEP and EEG; comparison of CSF-lg content; results of follow-up examinations. RESULTS： All 32 GBS cases and 30 patients with vascular headache were involved in the final analysis. ① Abnormal rate of neuroelectrophysiological test： 75% of NCV, 88% of F-wave, 53% of MCV, 25% of SEP, 47% of EMG and 31% of EEG. There were no significant differences among various types （P 〉 0.05）. ② Results of CSF-lg test： There were no significant differences among various types （P 〉 0.05）; however, abnormalities in experimental group was higher than those in control group （P 〈 0.01）. CONCLUSION ： Results of follow-up study suggest that improvement of clinical symptom is earlier than neuroelectrophysiological recovery; MCV and EMG recoveries are faster than that of NCV; the earlier the abnormality of EMG, the poorer the recovery. CSF4g recovers normally along improvement of clinical symptoms. It is of significance for neuroelectrophysiology and abnormality of CSF-Ig to determine degree of peripheral nerve demyelination and prognosis.

Phase Equilibrium Calculation of Mixtures: Use of the SAFT-BACK Equation of State for Binary Systems under Elevated Pressure

The statistical associating fluid theory (SAFT) Boublík Alder Chen Kreglewshi(BACK) equation of state is employed to correlate vapor liquid equilibria of 16 binary mixtures composed of supercritical fluids with other fluids at elevated pressures. The van der Waals mixing rules are used and the binary parameters are adjusted to experimental data. The SAFT BACK equation of state provides a better correlation of vapor liquid equilibrium than the original BACK equation. Consequently, the binary parameters computed from the data sets can be used to accurately predict the saturated densities of the vapor and liquid phases.

Phase Equilibrium Calculation of Mixtures: Comparison of SAFT, Modified SAFT, and BACK EOS for Supercritical CO_2-C_2H_5OH System

Three calculational models, statistical associating fluid theory (SAFT), modified SAFT, and Boublík Alder Chen Kreglewshi (BACK) are compared for supercritical CO 2 C 2H 5OH using a set of van der Waals type mixing rules for both the BACK equation of state (EOS) and the SAFT EOS. Equations are presented for the residual Helmholtz free energy, residual chemical potentials, and compressibilty factor for mixtures. A comparison with experimental vapor liquid equilibrium (VLE) data reveals that the BACK EOS together with the suggested mixing rules provides more accurate prediction of the binary system than the SAFT or the modified SAFT model with no adjustable binary parameters. The correlation results are improved with an adjustable parameter.

An Analytic Equation of State Based on SAFT-CP for Binary Non-Polar Alkane Mixtures Across the Critical Point

The description using an analytic equation of state of thermodynamic properties near the critical points of fluids and their mixtures remains a challenging problem in the area of chemical engineering. Based on the statistical associating fluid theory across the critical point (SAFT-CP), an analytic equation of state is established in this work for non-polar mixtures. With two binary parameters, this equation of state can be used to calculate not only vapor-liquid equilibria but also critical properties of binary non-polar alkane mixtures with acceptable deviations.