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.     

Electron microscopy of the arcuate nucleus of normal and 5-hydroxydopamine treated cats

The arcuate nucleus of normal cats and of cats treated with 5-hydroxydopamine (5-OHDA) was investigated by electron microscopy. The neurons of the arcuate nucleus were classified into three types, clear, intermediate and dark, according to their fine structure. The clear type contained numerous dense-cored vesicles and well developed cell organelles. All three types were frequently seen to be partially surrounded by glial processes. Many axo-somatic and axo-dendritic synapses mostly small in diameter were also observed around the neurons. Synaptic contacts were demonstrated between axon endings and axonal processes which contained elementary granules. After administration of 5-OHDA small and large dense-cored vesicles appeared in the nerve endings surrounding the neurons. The relationship between the dense-cored vesicles in the perikarya and dopamine was briefly discussed.     

Structural Change of DNA Induced by Nucleoid Proteins: Growth Phase-Specific Fis and Stationary Phase-Specific Dps

The effects of nucleoid proteins Fis and Dps of Escherichia coli on the higher order structure of a giant DNA were studied, in which Fis and Dps are known to be expressed mainly in the exponential growth phase and stationary phase, respectively. Fis causes loose shrinking of the higher order structure of a genome-sized DNA, T4 DNA (166 kbp), in a cooperative manner, that is, the DNA conformational transition proceeds through the appearance of a bimodal size distribution or the coexistence of elongated coil and shrunken globular states. The effective volume of the loosely shrunken state induced by Fis is 30–60 times larger than that of the compact state induced by spermidine, suggesting that cellular enzymes can access for DNA with the shrunken state but cannot for the compact state. Interestingly, Dps tends to inhibit the Fis-induced shrinkage of DNA, but promotes DNA compaction in the presence of spermidine. These characteristic effects of nucleotide proteins on a giant DNA are discussed by adopting a simple theoretical model with a mean-field approximation.     

Double Infection,Recombination, and Segregation of Two R Factors,R 100 and Rts1, and Their Possible Bearing on the Genetic Structure of R 100

Applying the observation by Yokota et al (1969) that a cell doubly harboring an R factor (R100) and a temperature sensitive R factor (Rts1) produces segregant R factors with various resistance patterns, a total of 271 segregant R factors were obtained. There were 163 resistant to (sul, str, kan), 39 resistant to (sul, str, cml, kan), 62 resistant to (sul, str, tet, kan) and finally 7 resistant to (tet, kan). More than 90% of the former 3 segregants were fi⁺ and the remainder, including all of the (tet, kan) segregants, were fi^?. Some fi^? segregants with the former 3 resistance patterns and all of the (tet, kan) segregants were nontransmissible. All of these segregants were still temperature sensitive. Based upon the results of three experiments; (a) the growth at 43 C to observe linked loss of the kan gene and the genes derived from R 100, (b) a conjugal analysis of the relevant resistant markers, and (c) a transductional analysis of these same markers, several conclusions were made. The 2 R factors both consisting of a circle were supposed to have recombined to form a larger circle which then further resulted in the final formation of smaller circles. The possible bearing of these observations and conclusions on the genetic structure of R 100 was discussed.     

Effects of rosuvastatin on electronegative LDL as characterized by capillary isotachophoresis: the ROSARY Study

Electronegative LDL, a charge-modified LDL (cm-LDL) subfraction that is more negatively charged than normal LDL, has been shown to be inflammatory. We previously showed that pravastatin and simvastatin reduced the electronegative LDL subfraction, fast-migrating LDL (fLDL), as analyzed by capillary isotachophoresis (cITP). The present study examined the effects of rosuvastatin on the more electronegative LDL subfraction, very-fast-migrating LDL (vfLDL), and small, dense charge-modified LDL (sd-cm-LDL) subfractions. Patients with hypercholesterolemia or those who were being treated with statins (n = 81) were treated with or switched to 2.5 mg/d rosuvastatin for 3 months. Rosuvastatin treatment effectively reduced cITP cm-LDL subfractions of LDL (vfLDL and fLDL) or sdLDL (sd-vfLDL and sd-fLDL), which were closely related to each other but were different from the normal subfraction of LDL [slow-migrating LDL (sLDL)] or sdLDL (sd-sLDL) in their relation to the levels of remnant-like particle cholesterol (RLP-C), apolipoprotein (apo) C-II, and apoE. The percent changes in cm-LDL or sd-cm-LDL caused by rosuvastatin were correlated with those in the particle concentrations of LDL or sdLDL measured as LDL-apoB or sdLDL-apoB and the levels of HDL-C, RLP-C, apoC-II, and apoE. In conclusion, rosuvastatin effectively reduced both the vfLDL subfraction and sd-cm-LDL subfractions as analyzed by cITP.     

Microflow system promotes acetaminophen crystal nucleation

It is known that interfaces have various impacts on crystallization from a solution. Here, we describe crystallization of acetaminophen using a microflow channel, in which two liquids meet and form a liquid–liquid interface due to laminar flow, resulting in uniform mixing of solvents on the molecular scale. In the anti‐solvent method, the microflow mixing promoted the crystallization more than bulk mixing. Furthermore, increased flow rate encouraged crystal formation, and a metastable form appeared under a certain flow condition. This means that interface management by the microchannel could be a beneficial tool for crystallization and polymorph control.     

New clade of silicified bolidophytes that belong to Triparma (Bolidophyceae,Stramenopiles)

The small phytoplankton genus Triparma belongs to the class Bolidophyceae and contains two distinct forms: silicified species and naked flagellated species (formerly Bolidomonas). Recent studies showed that four silicified species/strains (Triparma laevis f. inornata, T. laevis f. longispina, T. strigata, and T. aff. verrucosa) belong to a single clade that is paraphyletic, because it also contains an unclassified flagellated strain, and is sister to a flagellated species, T. eleuthera. In this study, we isolated and characterized two new strains of silicified species to test the phylogenetic unity of silicified bolidophytes. The isolates were identified as T. retinervis strains because they possessed fine areolation on the cell wall. 18S rDNA and rbcL phylogenetic analyses demonstrated that T. retinervis formed a new silicified clade that is sister to the flagellated species T. pacifica. This reveals that there are at least two distinct clades including both silicified and flagellated Triparma species.