Neuroleptic-like electroencephalographic changes in schizophrenics through biofeedback

Nine schizophrenic patients participated in a study which explored whether EEG feedback techniques could effect changes in the EEG similar to those associated with neuroleptic-induced improvement. During five sessions, each patient was presented feedback signals which continuously refected the discrepancy between characteristics of the patient's EEG power spectral profile and spectral profile characteristics associated by past research with neuroleptic induced clinical improvement. Significant within-session changes were observed for two of three EEG power spectrum bands of interest. No significant session-to-session EEG changes were observed. The results suggest that the EEG of schizophrenics can be temporarily altered, using feedback techniques, in a way that mimics the EEG changes that have been shown to occur with neuroleptic induced clinical improvement.The authors are indebted to Turan M. Itil, John W. Fredrickson, Michael Madwed, and Irene B. Francis. Senior authorship is shared equally.     

Regulation of natural killer cell activity by macrophages in the rheumatoid joint and peripheral blood

Recently, in another study, we observed that indomethacin, a prostaglandin synthetase inhibitor, significantly increased NK activity in both normal and rheumatoid arthritis (RA) peripheral blood (PB) but not in RA synovial fluid (SF). Because macrophages are a major source of prostaglandins, we examined the effect of macrophage-enriched adherent cells (AC) on NK activity as measured by a 3-hr Cr-release assay with K 562 cells. The removal of AC resulted in increased (p less than 0.01) NK activity in both normal and RA PB. In contrast, the removal of AC from RA SF resulted in a significant decrease (p less than 0.001) of NK activity. By using only nonadherent cells (NAC), NK activity in RA SF and synovial tissue (ST) was significantly reduced when compared to autologous RA PB (p less than 0.001). Enhancement of NK activity of SF NAC by both poly I:C and IL 2 was not dependent on AC. Mixing experiments demonstrated that the addition of synovial AC for 16 hr increased NK activity of synovial NAC to a level similar to that of unseparated mononuclear cells, whereas autologous PB AC suppressed NK activity of PB NAC. PB AC, when added to SF NAC, also increased NK activity. Supernatants from synovial mononuclear cells were stimulatory of synovial NAC NK activity, whereas normal PB mononuclear supernatants were suppressive. These observations document 1) a significant reduction of NAC-mediated NK activity in the rheumatoid joint as compared to PB from the same patient, and 2) that AC modulate NK activity differently in the rheumatoid joint as compared to RA or normal PB.     

Comparative phylogeography of two co‐distributed but ecologically distinct rainbowfishes of far‐northern Australia

Aim

To test the influence of historical and contemporary environment in shaping the genetic diversity of freshwater fauna we contrast genetic structure in two co‐distributed, but ecologically distinct, rainbowfish; a habitat generalist (Melanotaenia splendida) and a habitat specialist (M. trifasciata).

Location

Fishes were sampled from far northern Australia (Queensland and Northern Territory).

Methods

We used sequence data from one mitochondrial gene and one nuclear gene to investigate patterns of genetic diversity in M. splendida and M. trifasciata to determine how differences in habitat preference and historical changes in drainage boundaries affected patterns of connectivity.

Results

Melanotaenia splendida showed high levels of genetic diversity and little population structure across its range. In contrast, M. trifasciata showed high levels of population structure. Whereas phylogeographic patterns differed, both species showed a strong relationship between geographical distance and genetic differentiation between populations. Melanotaenia splendida showed a shallower relationship with geographical distance, and genetic differentiation was best explained by stream length and a lower scaled ocean distance (11.98 times coast length). For M. trifasciata, genetic differentiation was best explained by overwater distance between catchments and ocean distance scaled at 1.16 × 10⁶ times coast length.

Main conclusions

Connectivity of freshwater populations inhabiting regions periodically interconnected during glacial periods appears to have been affected by ecological differences between species. Species‐specific differences are epitomized here by the contrast between co‐distributed congeners with different habitat requirements: for the habitat generalist, M. splendida, there was evidence for greater historical genetic connectivity with oceans as a weaker barrier to gene exchange in contrast with the habitat specialist, M. trifasciata.     

Antibody for detection and quantitation of membrane-associated folate-binding protein from Lactobacillus casei

Lactobacillus casei cells contain a 25 kDa, membrane-associated, folate-binding protein (fbp), which is a component of the folate transport system. Polyclonal antibody to fbp (anti-fbp) has been prepared, and conditions have been established for detection and quantitation of the protein. Anti-fbp did not block [3H]folate transport or binding in L. casei cells. As judged by Western blots, the antibody reacted only with fbp on sodium dodecyl sulfate electrophoretograms of Triton X-100 extracts of L. casei membranes. Anti-fbp showed no cross-reactivity with L. casei dihydrofolate reductase, L. casei 5,10-methenyltetrahydrofolate synthetase, L1210 dihydrofolate reductase, rat liver dihydrofolate reductase, or L1210 folate-binding protein. Enzyme-linked immunosorbent assay measurements indicated the presence of an fbp in membranes of Lactobacillus salivarius and two transport-defective sublines of L. casei. Anti-fbp was used to demonstrate selective extraction, with n-butanol, of fbp from a mixture of Triton-solubilized L. casei membrane proteins; repression of fbp in membranes of L. casei cells grown on high levels of folate; and localization of fbp by electron microscopy, using anti-fbp in conjunction with goat anti-rabbit IgG gold conjugate, in L. casei membranes.     

Lateral diffusion in an archipelago. Distance dependence of the diffusion coefficient.

An understanding of the distance dependence of the lateral diffusion coefficient is useful in comparing the results of diffusion measurements made over different length scales, and in analyzing the kinetics of mobile redox carriers in organelles. A distance-dependent, concentration-dependent diffusion coefficient is defined, and it is evaluated by Monte Carlo calculations of a random walk by mobile point tracers in the presence of immobile obstacles on a triangular lattice, representing the diffusion of a lipid or a small protein in the presence of immobile membrane proteins. This work confirms and extends the milling crowd model of Eisinger, J., J. Flores, and W. P. Petersen (1986. Biophys J. 49:987-1001). Similar calculations for diffusion of mobile particles interacting by a hard-core repulsion yield the distance dependence of the self-diffusion coefficient. An expression for the range of short-range diffusion is obtained, and the distance scales for various diffusion measurements are summarized.     

Comparison of theN-glycoloylneuraminic andN-acetylneuraminic acid content of platelets and their precursors using high performance anion exchange chromatography

N-Acetylneuraminic acid (Neu5Ac) andN-glycoloylneuraminic acid (Neu5Gc) are distributed widely in nature. Using a Carbopac PA-1 anion exchange column, we have determined the ratios of Neu5Ac and Neu5Gc in hydrolysates of platelets and their precursors: a rat promegakaryoblastic (RPM) cell line and a human megakaryoblastic leukemia cell line (MEG-01). The ratio of Neu5Gc:Neu5Ac in cultured RPM cells is 16:1, whereas in platelet rich plasma and cultured MEG-01 cells it is 1:38 and 1:28, respectively. The nature of these sialic acids from RPM cells was verified using thin layer chromatography and liquid secondary ion mass spectrometry. The relevance of increased Neu5Gc levels in early stages of development is discussed.Abbreviations Neu5Ac N-acetylneuraminic acid - Neu5Gc N-glycoloylneuraminic acid - RPM rat promegakaryoblast - MEG-01 human megakaryoblastic leukaemia cell line - PAD pulsed amperometric detection - WGA wheat germ agglutinin - FCS foetal calf serum - PPEADF phosphatidylethanolamine dipalmitoyl - LSIMS liquid secondary ion mass spectrometry - HPAEC high performance anion exchange chromatography - TBA thiobarbituric acid