Biofeedback modification of frontal EMG in normal subjects

We carried out a controlled study on the voluntary control of the frontalis muscle by biofeedback procedures employing 20 normal subjects. Subjects were randomly divided into two groups of 10: (1) the biofeedback group and (2) the control group. Each of the two groups received five training sessions of about 40 minutes' duration each on different days. The results obtained are as follows: (1) In the biofeedback group, mean EMG levels decreased progressively and markedly from 2.16µVp-p min in the first session to 1.54µVp-p min in the last session. On the contrary, the control group did not show constant decreases in EMG levels over sessions. (2) The changes in the heart rate did not correlate with the changes in EMG activity. (3) The changes in the respiratory rate correlated with the changes in EMG activity.     

Amino acid sequence of Synechocystis 6714 ferredoxin: a unique structural feature of unicellular blue-green algal ferredoxin

The amino acid sequence of ferredoxin from Synechocystis 6714, a unicellular blue-green alga, was determined by a combination of conventional methods. The ferredoxin was composed of 96 amino acid residues and lacked methionine and tryptophan. The sequence was as follows: Ala-Ser-Tyr-Thr-Val-Lys-Leu-Ile-Thr- Pro-Asp-Gly-Glu-Asn-Ser-Ile-Glu-Cys-Ser-Asp-Asp-Thr-Tyr-Ile-Leu-Asp-Ala-Ala- Glu-Glu-Ala-Gly-Leu-Asp-Leu-Pro-Tyr-Ser-Cys-Arg-Ala-Gly-Ala-Cys-Ser-Thr-Cys- Ala-Gly-Lys-Ile-Thr-Ala-Gly-Ser-Val-Asp-Gln-Ser-Asp-Gln-Ser-Phe-Leu-Asp-Asp- Asp-Gln-Ile-Glu-Ala-Gly-Tyr-Val-Leu-Thr-Cys-Val-Ala-Tyr-Pro-Thr-Ser-Asp-Cys-Thr-Ile-Glu-Thr-His-Lys-Glu-Glu-Asp-Leu-Tyr. In an alignment of various ferredoxins with high homology from unicellular and filamentous blue-green algae, Synechocystis 6714 ferredoxin showed 4 gaps. Those between residues 9 and 10 and between residues 12 and 13 were unique for the ferredoxins from the unicellular algae Synechocystis 6714 and Aphanothece sacrum (ferredoxin I). Therefore, ferredoxins from unicellular algae were distinguishable from those of filamentous algae in terms of the presence of gaps. This feature appears to coincide with the phylogenetic division between the two types of blue-green algae.     

The amino acid sequence of the β-subunit: Of porcine enterotoxigenic Escherichia coli enterotoxin — Analysis and comparison with literature data

Abstract The amino acid composition and sequence of the β-subunit of heat-labile enterotoxin (LT) purified from a porcine (LT_p) strain, WT-1, of enterotoxigenic Escherichia coli was analysed, and the result was compared with that reported by Dallas and Falkow [Nature 288 (1980) 499-501] who deduced the amino acid sequence of LT_p from data on the DNA sequence of a porcine strain, EWD299. The purified β-subunit of the LT_p of WT-1 was carboxymethylated, succinylated, digested with chymotrypsin and subjected to high performance liquid chromatography (HPLC). The amino acid composition of the peptide peaks from the column were analysed and compared with the data reported by Dallas and Falkow. Only one fraction differed in amino acid composition from that reported, containing lysine instead of methionine. This fraction was found to consist of two peptides with the sequences Lys-Ser-Gly-Glu-Thr-Phe and Arg-Ile-Thr-Tyr. The former peptide is reported to have the sequence Met-Ser-Gly-Glu-Thr-Phe. Thus, the amino acid at position 43 from the N terminus of the β-subunit of LT_p is lysine, not methionine as reported. This is the first report which studied the amino acid sequence of LT_p analysed by protein toxin itself, not by DNA sequence analysis.     

Inhibition of DNA synthesis by methylglyoxal bis(guanylhydrazone) during lymphocyte transformation

The phytohemagglutinin induced DNA synthesis in guinea pig lymph node cells was inhibited remarkably by methylglyoxal bis(guanylhydrazone). This inhibitory effect was dependent on the time of its addition to the lymph node cell culture after stimulation with phytohemagglutinin. If methylglyoxal bis(guanylhydrazone) was added 48 hr after the stimulation, no inhibition of DNA synthesis was observed. Exogenous spermidine added at an early time of cell culture reversed the inhibitory effect of methylglyoxal bis(guanylhydrazone). However, no reversion occurred when spermidine was added at a late time of the cell culture.     

Eighteen Novel Human Genes Regionally Mapped on Chromosome 11

Expression sequence tags (EST) obtained by sequencing a randomlyprimed cDNA library and gene signatures (GS) obtained by sequencinga 3'-directed cDNA library can identify genes that are activein the source cells. Eight ESTs and ten GSs which representnovel human genes, except for one GS, and which have been assignedto human chromosome 11 were used to select cosmids from a chromosome11-specific cosmid library. These cosmids were regionally mappedusing the fluorescence in situ hybridization technique.     

Analysis of an expression profile of genes in the human adipose tissue

Increasing evidence suggests that in addition to storing excess energy as fat, adipose tissue acts as an endocrine organ secreting various factors into the blood stream. Every time a new factor is found in adipose tissue, however, its implication is discussed independently, and a systematic analyses based upon a global view of gene expression of this tissue has not been performed. To describe the function of this tissue in terms of gene expression, and to find new factors, we performed random complementary DNA (cDNA) sequencing using a 3'-directed cDNA library that faithfully represents the composition of the messenger RNA (mRNA). Various well-known but unexpected genes, including those for gelsolin, plasma glutathione peroxidase (GPX-3) and carboxypeptidase E (CPE) were shown to be very active. By comparing the expression profile of active genes in the adipose with those of other tissues and with data in dbEST, we identified seven new genes that are specifically expressed in adipose tissue. Among these, one encoded a protein with collagen-like repeats and a putative secretion signal. These data can be used as new tools for analyses of the physiology of this tissue, as well as the etiology and complications of obesity.     

High-performance liquid chromatography of methamphetamine and its related compounds in human urine following derivatization with fluorescein isothiocyanate

A high-performance liquid chromatographic method with fluorescence detection for the determination of methamphetamine and its related compounds is reported. Methamphetamine, amphetamine, norephedrine, p-hydroxymethamphetamine and 1-phenylethylamine as an internal standard were extracted from human urine, derivatized with fluorescein-4-isothiocyanate, and then separated on a reversed-phase column within 36 min. The fluorescence intensity of the effluent was monitored at excitation and emission wavelengths of 496 and 518 nm, respectively. Calibration curves were confirmed to be linear up to at least 100 pmol on the column with a correlation coefficient (r) of 0.994–0.999 for the target compounds. The detection limits (S/N=3) were 55–105 fmol per 20-μl injection. The method was successfully applied to urine samples taken from methamphetamine addicts.     

Isoform-Specific Effects of Apolipoproteins E2, E3, and E4 on Cerebral Capillary Sequestration and Blood-Brain Barrier Transport of Circulating Alzheimer's Amyloid β

Abstract: Cerebral capillary sequestration and blood-brain barrier (BBB) permeability to apolipoproteins E2 (apoE2), E3 (apoE3), and E4 (apoE4) and to their complexes with sAβ_1–40, a peptide homologous to the major form of soluble Alzheimer's amyloid β, were studied in perfused guinea pig brain. Cerebrovascular uptake of three apoE isoforms was low, their blood-to-brain transport undetectable, but uptake by the choroid plexus significant. Binding of all three isoforms to sAβ_1–40 in vitro was similar with a K _D between 11.8 and 12.9 n M . Transport into brain parenchyma and sequestration by BBB and choroid plexus were negligible for sAβ_1–40-apoE2 and sAβ_1–40-apoE3, but significant for sAβ_1–40-apoE4. After 10 min, 85% of sAβ_1–40-apoE4 taken up at the BBB remained as intact complex, whereas free sAβ_1–40 was 51% degraded. Circulating apoE isoforms have contrasting effects on cerebral capillary uptake of and BBB permeability of sAβ. ApoE2 and apoE3 completely prevent cerebral capillary sequestration and blood-to-brain transport of sAβ_1–40. Conversely, apoE4, by entering brain microvessels and parenchyma as a stable complex with sAβ, reduces peptide degradation and may predispose to cerebrovascular and possibly enhance parenchymal amyloid formation under pathological conditions.     

Effect of 1,25-dihydroxyvitamin D3 on induction of scavenger receptor and differentiation of 12-O-tetradecanoylphorbol-13-acetate-treated THP-1 human monocyte like cells

We investigated the effect of 1,25-dihydroxyvitamin D₃ (1,25(OH)₂D₃) on the expression of scavenger receptors in human monocytic cell line (THP-1 cells) treated for 24 h with 12-O-tetradecanoylphorbol-13-acetate (TPA) which induces their differentiation into macrophages. The capacity to degrade ¹²⁵I-labeled acetyl low density lipoprotein (LDL) was developed in accordance with macrophage differentiation. The treatment with 10 nM 1,25(OH)₂D₃ for 72 h inhibited the degradation of acetyl LDL by THP-1 macrophages in a dose-dependent manner, suggesting that 1,25(OH)₂D₃ inhibits scavenging function in macrophages. In order to clarify the mechanism of its inhibitory effect on degradation of acetyl LDL, we performed the ligand binding assay using ¹²⁵I-labeled acetyl LDL. Scatchard analysis revealed that 1,25(OH)₂D₃ decreased the number of scavenger receptors without changing the affinity for acetyl LDL. We next examined the effect of 1,25(OH)₂D₃ on the expression of scavenger receptor mRNA. The mRNA of type I scavenger receptor was first detected in THP-1 cells 4 days after the treatment with TPA, the mRNA level increased up to 6 days, and then decreased. The treatment with 1,25(OH)₂D₃ for 72 h dramatically decreased the mRNA levels after the acquisition of macrophage phenotypes as evidenced by nonspecific esterase staining. However, 1,25(OH)₂D₃ did not affect the activity of non-specific esterase nor the induction of interleukin-1β mRNA by lipopolysaccharide in THP-1 macrophages. These findings suggest that 1,25(OH)₂D₃ exclusively decreases the expression of scavenger receptors in TPA-induced THP-1 macrophages without affecting the basic cellular functions as macrophages. © 1995 Wiley-Liss Inc.