Evaluation of intestinal microbiota,short-chain fatty acids,and immunoglobulin a in diversion colitis

It is reported that an increase in aerobic bacteria, a lack of short-chain fatty acids (SCFAs), and immune disorders in the diverted colon are major causes of diversion colitis. However, the precise pathogenesis of this condition remains unclear. The aim of the present study was to examine the microbiota, intestinal SCFAs, and immunoglobulin A (IgA) in the diverted colon. Eight patients underwent operative procedures for colostomies. We assessed the diverted colon using endoscopy and obtained intestinal samples from the diverted colon and oral colon in these patients. We analyzed the microbiota and SCFAs of the intestinal samples. The bacterial communities were investigated using a 16S rRNA gene sequencing method. The microbiota demonstrated a change in the proportion of some species, especially Lactobacillus, which significantly decreased in the diverted colon at the genus level. We also showed that intestinal SCFA values were significantly decreased in the diverted colon. Furthermore, intestinal IgA levels were significantly increased in the diverted colon. This study was the first to show that intestinal SCFAs were significantly decreased and intestinal IgA was significantly increased in the diverted colon. Our data suggest that SCFAs affect the microbiota and may play an immunological role in diversion colitis.     

Isolation and characterization of a novel Enterococcus faecalis bacteriophage phiEF24C as a therapeutic candidate.

Vancomycin-resistant Enterococcus faecalis (VRE) has become a significant threat in nosocomial settings. Bacteriophage (phage) therapy is frequently proposed as a potential alternative therapy for infections caused by this bacterium. To search for candidate therapeutic phages against Enterococcus faecalis infections, 30 Enterococcus faecalis phages were isolated from the environment. One of these, virulent phage phiEF24C, which has a broad host range, was selected for analysis. The plaque-forming ability of phiEF24C was virtually unaffected by differences in the clinical host strains. Furthermore, the phage had a shorter latent period and a larger burst size than ordinary tailed phages, indicating that phiEF24C has effective lytic activity against many Enterococcus faecalis strains, including VRE. Morphological and genomic analyses revealed that phiEF24C is a large myovirus (classified as family Myoviridae morphotype A1) with a linear double-stranded DNA genome of c. 143 kbp. Analyses of the N-terminal amino acid sequences of the virion proteins, together with the morphology and the genome size, speculated that phiEF24C is closely related to other myoviruses of Gram-positive bacteria that have been used experimentally or practically for therapy or prophylaxis. Considering these results, phiEF24C may be a potential candidate therapeutic phage against Enterococcus faecalis infections.     

Effect of thyrotropin-releasing hormone (TRH) on EEG topography

EEG topography by a microcomputer system (ATAC-3700 Nihon-Kohden) was performed in the rabbit in order to investigate the mechanism of TRH action on the brain wave. Power spectral analysis was carried out using a fast Fourier transform algorithm. The square root of the power spectra was defined as the equivalent potential over each frequency band by Ueno & Matsuoka's method. Potential fields of EEG frequency band were printed out on the topographic maps. The potentials of the electrocortical delta and theta waves were high, while the potentials of the alpha, beta 1 and beta 2 waves were low. Stimulation of the nucleus ventralis anterior (VA) by 3 Hz and 8 Hz resulted in a decrease in these potentials, especially, those of the alpha, beta 1 and beta 2 waves. The potentials of the alpha and fast waves were increased following unilateral destruction of VA. In the rabbit, in which TRH 0.5 mg/kg had been administered beforehand, there was no decrease in the potential of each wave induced by stimulation of VA with frequencies of 3 Hz and 8 Hz. The findings suggest involvement of the diffuse thalamocortical projection system in the activation of EEG by TRH.     

Identification of a modified nucleoside located in the first position of the anticodon of Torulopsis utilis tRNAPro as 5-carbamoylmethyluridine

An unknown nucleoside in the first position of the anticodon of Torulopsis utilis tRNAPro has been isolated. The UV, 1H NMR and secondary ion mass spectra indicated that this nucleoside is a uridine derivative, 5-carbamoylmethyluridine. The structure was completely established by comparison of the instrumental analysis results and chromatographic behavior of the isolated nucleoside with those of a synthetic sample.     

Enzymatic replacement of nucleotide sequences in the D-loop of T. utilis tRNATyr and its effect on aminoacylation

An efficient method for replacement of nucleotide sequences in the D-loop of T. utilis tRNATyr has been developed. An abnormal tRNATyr lacking in tetranucleotide D16-D-Gm-G19 in its D-loop has been reconstructed by this method and shown to accept tyrosine to about 55% of the aminoacylation level observed for intact tRNATyr. This suggests that the deleted sequence itself is not essential for recognition by TyrRS but a conformational instability of the tRNA possibly caused by the disruption of tertiary interactions between the D-loop and T psi C-loop might have influenced the forward reaction rate leading to the decreased level of aminoacylation.     

Human naive epiblast cells possess unrestricted lineage potential

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