Growth of measles virus in nervous tissues. III. Neurovirulence of SSPE virus in ferrets.

The Niigata-1 strain isolated from a patient with subacute sclerosing panencephalitis (SSPE) was inoculated intracerebrally into ferrets. Neurological signs developed in about 1 week in most of the animals. Histopathological examinations of the central nervous tissues revealed degenerative lesions in the parenchyma of the brains and inflammatory reactions predominantly in the meninges and choroid plexus. Virus antigen was demonstrated mainly in the nerve cells by immunofluorescent staining. The results indicated high affinity of the Niigata-1 strain to the nerve cells. In contrast, the Mantooth strain of SSPE virus in cell-free state did not exhibit neurovirulence in ferrets.     

Reinitiation of chromosome replication in the presence of chloramphenicol under an integratively suppressed state by R6K.

The autonomous replication of an R plasmid, R6K (amp, str) was shown not to be affected by chloramphenicol. It provoked integrative suppression and gave rise to Hfr strains when integrated into the chromosome of a strain of Escherichia coli K-12 with a temperature-sensitive mutation in the gene, dnaA. An Hfr strain designated as Hfr(R6K) no. 1 was thus obtained and characterized. It was not completely stable as shown by a plating efficiency of 0.6 at 42 C relative to that at 30 C. The density labeling and the ultracentrifugation analysis suggested that the deoxyribonucleic acid replication in this Hfr strain did not stop immediately after completion of the round already started before temperature shift-up and the addition of chloramphenicol. These observations are discussed in relation to a possibility that the chromosome replication of this Hfr strain is under the control of the integrated plasmid at a nonpermissive temperature.     

Amino acid sequence of an active fragment of potato proteinase inhibitor IIa.

The complete amino acid sequence of an active fragment of potato proteinase inhibitor IIa has been established by the Edman degradation procedure and the carboxypeptidase technique. Sequence analyses were carried out on the reduced and carboxymethylated active fragment and its tryptic peptides. To aid in the alignment of some tryptic peptides, the partial sequences of two fragments obtained by selective tryptic cleavage of the reactive site peptide bond of inhibitor IIa at acidic pH, with subsequent reduction and carboxymethylation, were also analyzed. The active fragment consisted of 45 amino acid residues including 6 half-cystine residues. Degradation of the intact active fragment by subtilisin [EC 3.4.21.14.] at pH 6.5. yielded 3 cystine-containing peptides. Sequence analyses of these peptides revealed that the 3 disulfide linkages were located between Cys(10) and Cys(24), Cys(14) and Cys(35), and Cys(20) and Cys(43). The reactive site peptide bond of inhibitor IIa, a Lys-Ser bond, was located between positions 32 and 33 of the active fragment. The overall sequence of the active fragment was quite different from those of potato chymotrypsin inhibitor I (subunit A) and potato carboxypeptidase inhibitor.     

A Bacillus subtilis dnaG mutant harbours a mutation in a gene homologous to the dnaN gene of Escherichia coli

A dnaG mutation of Bacillus subtilis, dnaG5, was found to be linked closely to recF. We have reported previously that two putative dna genes, 'dnaA' and 'dnaN', highly homologous to Escherichia coli's dnaA and dnaN, respectively, were located adjacent to recF [Ogasawara et al., EMBO J., 4 (1985) 3345-3350]. Transformation by various fragments cloned from the 'dnaA'-recF region of the wild-type cell revealed that a 532-bp AluI fragment containing 5'-portion of the 'dnaN' gene could transform the dnaG5 mutation. The nucleotide (nt) sequence of the same fragment cloned from the mutant cell shows a single nt change in the ORF of 'dnaN' which in turn causes a single amino acid alteration from Gly to Arg. The 'dnaN' gene is now proven to be a dna gene, mutations in which result in instant arrest of chromosomal replication.     

Automated microanalysis of adenosine phosphates, phosphocreatine, creatine, and lactate in muscle

An automated enzymatic procedure suitable for determination of ATP, ADP, AMP, phosphocreatine, creatine, and lactate in needle biopsies of human skeletal muscle (ca. 30 mg dry wt) using a fast centrifugal analyzer (Multistat III, Instrumentation Laboratory Inc.) is presented. Coefficients of variation ranged from 0.7 to 4.2% for multiple determinations of ATP, ADP, phosphocreatine, and creatine; from 6 to 24% for lactate; and from 9 to 20% for AMP. The procedure should be usable, with appropriate modification, with other tissues and with other fast centrifugal analyzers. Muscle samples are collected into liquid freon, lyophilized, and extracted with 600 microliter of 0.65 M perchloric acid. Neutralized supernatants can be stored for up to 3 years at -80 degrees C with no significant deterioration. The procedure takes much less time than similar manual procedures and gives better reproducibility, particularly for ADP and AMP.     

Effects of acorn masting on population dynamics of three forest-dwelling rodent species in Hokkaido,Japan

The effects of the abundance of acorns of the oak, Quercus crispula, on the population dynamics of three rodent species (Apodemus speciosus, A. argenteus, and Clethrionomys rufocanus) were analyzed using time series data (1992–2006). The data were obtained in a forest in northern Hokkaido, Japan, by live trapping rodents and directly counting acorns on the ground. Apodemus speciosus generally increased in abundance following acorn masting. However, the clear effect of acorn abundance was not detected for the other two rodent species. Acorns of Q. crispula contain tannins, which potentially have detrimental effects on herbivores. Apodemus speciosus may reduce the damage caused by acorn tannins with tannin-binding salivary proteins and tannase-producing bacteria, whereas such physiological tolerance to tannins is not known in the other two rodent species. The differences in the effects of acorns between the three species may be due to differences in their physiological tolerance to tannins.     

Purification and characterization of proteinase inhibitors from adzuki beans (Phaseolus angularis).

Two proteinase inhibitors, designated as inhibitors I and II, were purified from adzuki beans (Phaseolus angularis) by chromatographies on DEAE- and CM-cellulose, and gel filtration on a Sephadex G-100 column. Each inhibitor shows unique inhibitory activities. Inhibitor I was a powerful inhibitor of trypsin [EC 3.4.21.4], but essentially not of chymotrypsin ]EC 3.4.21.1]. On the other hand, inhibitor II inhibited chymotrypsin more strongly than trypsin. The molecular weights estimated from the enzyme inhibition were 3,750 and 9,700 for inhibitors I and II, respectively, assuming that the inhibitions were stoichiometric and in 1 : 1 molar ratio. The amino acid compositions of both inhibitors closely resemble those of low molecular weight inhibitors of other leguminous seeds: they contain large amounts of half-cystine, aspartic acid and serine, and little or no hydrophobic and aromatic amino acids. Inhibitor I lacks both tyrosine and tryptophan residues. The molecular weights were calculated to be 7,894 and 8,620 for inhibitors I and II, respectively. The reliability of these molecular weights was confirmed by the sedimentation equilibrium and 6 M guanidine gel filtration methods. On comparison with the values obtained from enzyme inhibition, it was concluded that inhibitor I and two trypsin inhibitory sites on the molecule, whereas inhibitor II had one chymotrypsin and one trypsin inhibitory sites on the molecule.