A portable multi-channel recording system for analysis of acceleration and angular velocity in six dimension.

A portable recording system was developed for analysis of more than three analog signals collected in field works. Stereo audio recorder, available as consumer products, was made use for a core cornponent of the system. For the two tracks of recording, a multiplexed analog signal is stored on one track, and reference code on the other track. The reference code indicates the start of one cycle for multiplexing and swiching point of each channel. Multiplexed signal is playbacked and decoded with a reference of the code to reconstruct original profiles of the signal. Since commercial stereo recorders have cut DC component off, a fixed reference voltage is inserted in the sequence of multiplexing. Change of voltage at switching from the reference to the data channel is measured from playbacked signal to get the original data with its DC component. Movement of vehicles and human head were analyzed by the system. It was verified to be capable to record and analyze multi-channel signal at a sampling rate more than 10Hz.     

Fumonisin occurrence in corn from high- and low-risk areas for human esophageal cancer in China.

Forty-seven corn samples were collected in 1989 from Linxian and Shangqiu Counties in Henan Province, the high- and low-risk areas, respectively, for human esophageal cancer in the People's Republic of China. The samples were analyzed for fumonisin (fumonisin B1 [FB1] and FB2) contamination. Of the fumonisin-positive samples, the mean levels in Linxian corn were found to be 872 ng/g for FB1 and 448 ng/g for FB2, while the Shangqiu corns had 890 ng of FB1 and 330 ng of FB2 per g. The incidence of fumonisin contamination of Linxian corn (48%) was about two times higher than that of Shangqiu corn (25%), and the former corn samples were frequently cocontaminated with trichothecenes. Fusarium species isolated from corn from Linxian County produced FB1 at levels ranging from 1,280 to 11,300 micrograms/g.     

Role of marginal stress fibers formed in the rat vascular endothelial cells

Fluorescence cytochemistry using en face preparations of rat vascular endothelial cells (ECs) revealed the localization of actin, fibronectin (FN) and fibronectin receptor (FNR) along not only central stress fibers (SFs) but also the cell margins. Electron microscopy showed very close proximity between the topographical distribution of intracellular microfilament bundles and that of subendothelial FN in the EC margins. Therefore, these basal and marginal actin cables may be comparable to the well-established central SFs present in ECs. Formation of the central SFs was induced in ECs or mesothelial cells in response to tension, by which their cellular integrity seems to be effectively maintained. However, even when central SF formation was inhibited by cytochalasin D, the ECs with marginal SFs showed high resistance to mechanical tension, whereas mesenteric mesothelial cells having no such fibers easily lost their integrity. Thus, together with central SFs, the marginal SFs characteristic of rat vascular ECs may play an essential role in strengthening cell-matrix adhesion.     

The cdc2-related protein p40MO15 is the catalytic subunit of a protein kinase that can activate p33cdk2 and p34cdc2.

Activation of the cyclin-dependent protein kinases p34cdc2 and p33cdk2 requires binding with a cyclin partner and phosphorylation on the first threonine residue in the sequence THEVVTLWYRAPE. We present evidence that this threonine residue, number 160 in p33cdk2, can be specifically phosphorylated by a cdc2-related protein kinase from Xenopus oocytes called p40MO15. Binding to cyclin A and phosphorylation of this threonine are both required to activate fully the histone H1 kinase activity of p33cdk2. In cell extracts, a portion of p40MO15 is found in a high molecular weight complex that is considerably more active than a lower molecular weight form. Wild-type MO15 protein expressed in bacteria does not possess kinase activity, but acquires p33cdk2-T160 kinase activity after incubation with cell extract and ATP. We conclude that p40MO15 corresponds to CAK (cdc2/cdk2 activating kinase) and speculate that, like p33cdk2 and p34cdc2, p40MO15 requires activation by phosphorylation and association with a companion subunit.     

Depressed sliding velocity of isolated cardiac myosin from cardiomyopathic hamsters: Evidence for an alteration in mechanical interaction of actomyosin

We measured the relative sliding velocity of cardiomyopathic hamster cardiac myosin on actin cables by using anin vitro motility assay system. We also investigated the relationship between the velocity and both myosin isozyme content and ATPase activity. Cardiac myosin was obtained from cardiomyopathic hamsters (BIO 14.6;B) aged 3,6,9, and 18 months and age-matched controls (F1B;F). Long well-organized actin cables of an alga,Nitellopsis, wer used for the motility assay. Small latex beads (2 m in diameter) were coated with purified cardiac myosin. When myosin-coated beads were introduced into an algal cell in the presence of Mg-ATP, myosin interacted with actin and dragged the beads. Active movement of the beads along the actin cables was observed under a photomicroscope and the velocity was measured. The velocity was significantly lower in B than in F for each age group (0.47 vs. 0.71 m/s at the age of 3 months, p<0.05; 0.44 vs. 0.88 m/s at 6 months, p<0.01; 0.44 vs. 0.67 m/s at 9 months, p<0.01; 0.35 vs. 0.52 m/s at 18 months, p<0.05). Both Ca²⁺-activated ATPase activity and the percentage of -myosin heavy chain were also lower in B than in F for each age group. When examined for individual specimens, there was a positive correlation between the velocity and both myosin Ca²⁺-activated ATPase activity (r=0.84) and percentage of -myosin heavy chain (r=0.83). These data points of both control and cardiomyopathic hamsters were distributed near the regression line obtained from control and thyroxine-treated rabbits reported previously. The present results indicate that the difference in mechanical properties between control and cardiomyopathic cardiac myosin is attributed to isozyme redistribution and not to a qualitative change in each myosin molecule.     

Molecular characterization of a STreptococcus mutans mutant altered in environmental stress responses.

A mutant defective in aciduricity, GS5Tn1, was constructed following mutagenesis of Streptococcus mutans GS5 with the conjugative transposon Tn916. The mutant grew poorly at acidic pH levels and was sensitive to high osmolarity and elevated temperatures. These properties resulted from a single insertion of Tn916 into the GS5 chromosome, and the DNA fragment harboring the transposon was isolated into the cosmid vector, charomid 9-20. Spontaneous excision of Tn916 from the cosmid revealed that Tn916 inserted into a 8.6-kb EcoRI fragment. On the basis of the restriction analyses of insert fragments, it was found that Tn916 inserted into a 0.9-kb EcoRI-XbaI fragment. Nucleotide sequence analysis of this fragment indicated the presence of two open reading frames, ORF1 and ORF2. By using a marker rescue strategy, a 6.0-kb HindIII fragment including the target site for Tn916 insertion and the 5' end of ORF1 was isolated and sequenced. The deduced amino acid sequences of ORF1 and ORF2 showed significant homology with the diacylglycerol kinase and Era proteins, respectively, from Escherichia coli. Nucleotide sequence analysis of the Tn916 insertion junction region in the GS5Tn1 chromosome revealed that the transposon inserted near the 3' terminus of ORF1. Restoration of ORF1 to its original sequence in mutant GS5Tn1 was carried out following transformation with integration vector pVA891 containing an intact ORF1. The resultant transformant showed wild-type levels of aciduricity as well as resistance to elevated temperatures and high osmolarity. These results suggest that the S. mutans homolog of diacylglycerol kinase is important for adaptation of the organism to several environmental stress signals.     

Structure of the extracellular ferredoxin from Rhodospirillum rubrum: close similarity to clostridial ferredoxins

The amino acid sequence of an [8Fe-8S] ferredoxin isolated from the culture medium of Rhodospirillum rubrum, a photosynthetic purple non-sulfur bacterium, was determined by a combination of various conventional procedures. The sequence was A-Y-K-I-E-E-T-C-I-S-C-G-A-C-A-A-E-C-P-V-N-A-I-E-Q-G-D-T-I-F-V-V-N-A-D-T-C-I-D-C - G-N-C-A-N-V-C-P-V-G-A-P-V-A-E (55 amino acid residues). It lacked methionine, leucine, histidine, arginine, and tryptophan. The molecular weight was calculated to be 5,568 excluding iron and sulfur atoms. The distribution of 8 cysteine residues was exactly the same as that of clostridial-type ferredoxin, suggesting retention of the duplication of the bacterial ancestral ferredoxin gene. The extracellular ferredoxin of R. rubrum was compared with other ferredoxins observed in closely related photosynthetic bacteria and the evolutionary significance of this ferredoxin is discussed.     

The sugar chains of cold-insoluble globulin. A protein related to fibronectin.

Cold-insoluble globulin isolated from bovine plasma contains six asparagine-linked sugar chains in 1 molecule (a dimeric form). These sugar chains were released from the polypeptide backbone by hydrazinolysis and labeled by reduction with NaB[3H]4. Most of these sugar chains contain N-acetylneuraminic acid and can be separated by paper electrophoresis. By combination of sequential exoglycosidase digestion and methylation study, their structures were elucidated as Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 6(NeuAc alpha 2 leads to 6Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 3)Man beta 1 leads to 4GlcNAc beta 1 leads to 4GlcNAc, NeuAc alpha 2 leads to 6 or 4Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 6(NeuAc alpha 2 leads to 4 or 6Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 3)Man beta 1 leads to 4GlcNAc beta 1 leads to 4GlcNAc, NeuAc alpha 2 leads to 6Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 6[NeuAc alpha 2 4Gal beta 1 leads to 3(NeuAc alpha 2 leads to 6)GlcNAc beta 1 leads to 2Man alpha 1 leads to 3]-Man beta 1 leads to 4GlcNAc beta 1 leads to 4GlcNAc and NeuAc alpha 2 leads to 4Gal beta 1 leads to 3(NeuAc alpha 2 leads to 6)GlcNAc beta 1 leads to 2Man alpha 1 leads to 6[NeuAc alpha 2 leads to 4Gal beta 1 leads to 3(NeuAc alpha 2 leads to 6)GlcNAc beta 1 leads to 2Man alpha 1 leads to 3]man beta 1 leads to 4GlcNAc beta 1 leads to 4GlcNAc.     

The carbohydrate of bovine prothrombin. Occurrence of Gal beta 1 leads to 3GlcNAc grouping in asparagine-linked sugar chains.

Bovine prothrombin contains three asparagine-linked sugar chains in 1 molecule. The sugar chains were quantitatively released from the polypeptide backbone by hydrazinolysis. All of the oligosaccharides thus obtained contain N-acetylneuraminic acid. Sialidase treatment of these acidic oligosaccharides released three isomeric oligosaccharides, N-1, N-2 and N-3. N-3 was a typical complex type asparagine-linked sugar chain widely found in other glycoprotein, while N-1 and N-2 were unique, because they contain Gal beta 1 leads to 3GlcNAc grouping in the outer chain moiety. By comparing the data of methylation analysis of the acidic oligosaccharides before and after sialidase treatment, the structures of the sugar chains of bovine prothrombin were confirmed as a mixture of NeuAc alpha 2 leads to 6Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 6(NeuAc alpha 2 leads to 6Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 3)Man beta 1 leads to 4GlcNAc beta 1 leads to 4GlcNAc leads to Asn, NeuAc alpha 2 leads to 6Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 6[NeuAc alpha 2 leads to 3Gal beta 1 leads to 3(NeuAc alpha 2 leads to 6)GlcNAc beta 1 leads to 2Man alpha 1 leads to 3]Man beta 1 leads to 4GlcNAc beta 1 leads to 4GlcNAc leads to Asn, NeuAc alpha 2 leads to 3Gal beta 1 leads to 3(NeuAc alpha 2 leads to 6)GlcNAc beta 1 leads to 2Man alpha 1 leads to 6[NeuAc alpha 2 leads to 3Gal beta 1 leads to 3(NeuAc alpha 2 leads to 6)GlcNAc beta 1 leads to 2Man alpha 1 leads to 3]Man beta 1 leads to 4GlcNAc beta 1 leads to 4GlcNAc leads to Asn and their partially desialized forms.