COMPLEMENT SYSTEM AS A MARKER OF IMMUNE DYSFUNCTION IN CHILDREN AUTISM SPECTRUM DISORDERS

It is known that functional activity of complement system depends not only on balance and concentration of components participating in formation of the system end products, but also on levels of inhibitory activities. Numerous relations with hemostasis also substantially contribute to general level of complement system activity. Changes in complement system functioning are inevitable during chronic diseases accompanied with immune system dysregulation. All mental diseases tend to be chronic and are they aggravated by patients’ immune system changes. Autism spectrum disorders in children is a group of mental disorders. Immune system dysregulation is usually detected in such patients, manifesting as excessive susceptibility to viral and bacterial infections. Therefore, the level of its functional activity is diagnostically and prognostically significant in this pathology, since the complement system is a key element of immune system.We have evaluated functional activity of complement system in patients with autistic spectrum disorders, using the method which was developed earlier. It is based on the reaction of the protozoa (Tetrahymena pyriformis) which are both targets and activators for the complement system. The complement system capacity (cSC) was used as the main parameter of complement evaluation. The half-time of protozoa survival (T50) was defined using the BioLat device for each serum specimen added at four concentrations (1/20, 1/40, 1/80, 1/160 dilution). The complement capacity was calculated as the area enclosed by influence curve of the reciprocals of T50 and the serum dilution. According to Mann–Whitney U test, the difference between patients’ and healthy volunteers’ groups was established as Z = 4.43 (by T50 at 1/160 dilution), p < 0.001 and by cSCas Z = 5.8, p < 0.001. cSC was calculated from the results obtained at each serum concentration measured. The difference between the two groups according to Mann–Whitney U test appeared to be more significant than the difference according to T50. Therefore, cSC was taken as the main characteristic of complement system function.The contribution of hemostasis plasma components to complement system functional activity level was estimated by determination of complement capacity in plasma and serum of each blood sample from 6 patients with autism spectrum disorders and 5 healthy donors. All healthy donors showed small difference between plasma and serum complement capacity, and their complement activity was higher in plasma. In patients’ group, the complement capacity levels in plasma and serum differed significantly. The cSC levels of two patients were higher in serum than in plasma, and the cSC levels of three other patients were significantly higher in plasma than in serum. Differential involvement of coagulation into the complement system activation may be indicative for the immune system dysfunction which is observed in patients with autistic spectrum disorders of different etiology

The MHD nature of ionospheric wave packets excited by the solar terminator

We obtained the first experimental evidence for the magnetohydrodynamic (MHD) nature of ionospheric medium-scale travelling wave packets (MSTWP). We used data on total electron content (TEC) measurements obtained at the dense Japanese network GPS/GEONET (1220 stations) in 2008-2009. We found that the diurnal, seasonal and spectral MSTWP characteristics are specified by the solar terminator (ST) dynamics. MSTWPs are the chains of narrow-band TEC oscillations with single packet's duration of about 1-2 hours and oscillation periods of 10-20 minutes. Their total duration is about 4--6 hours. The MSTWP spatial structure is characterized by a high degree of anisotropy and coherence at the distance of more than 10 wavelengths. The MSTWP direction of travelling is characterized by a high directivity regardless of seasons. Occurrence rate of daytime MSTWPs is high in winter and during equinoxes. Occurrence rate of nighttime MSTIDs has its peak in summer. These features are consistent with previous MS travelling ionosphere disturbance (TID) statistics obtained from 630-nm airglow imaging observations in Japan. In winter, MSTWPs in the northern hemisphere are observed 3-4 hours after the morning ST passage. In summer, MSTWPs are detected 1.5-2 hours before the evening ST occurrence at the point of observations, at the moment of the evening ST passage in the magneto-conjugate point. Both the high Q-factor of oscillatory system and synchronization of MSTWP occurrence with the solar terminator passage at the point of observations and in the magneto-conjugate area testify the MHD nature of ST-excited MSTWP generation. The obtained results are the first experimental evidence for the hypothesis of the ST-generated ion sound waves.Comment: 12 pages, 3 figure