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M Oki

Publications and source records attributed to M Oki.

At least 37 records · Page 2Linked to original sources
PubMed1997

Functional and structural features of the holin HOL protein of the Lactobacillus plantarum phage phi gle: analysis in Escherichia coli system.

Lactobacillus plantarum phage phi gle has two consecutive cell lysis genes hol-lys (Oki et al., 1996b). In the present study, functional and structural properties of the hol protein (Hol) were characterized in Escherichia coli. Electron microscopic examinations showed that hol under plac in E. coli XL1-Blue injured the inner membrane to yield empty ghost cells with the bulk of the cell wall undisturbed. Northern blot analysis indicated that hol-lys genes under plac were co-transcribed, although the amount of hol transcript was larger than that of lys, ceasing via an apparently rho-independent terminator just downstream of hol. However, deletion and/or fusion experiments suggested that: (1) the N-terminal half of phi gle Hol composed of three putative transmembrane domains may be responsible for interaction with membrane; (2) the N-terminal end (five amino acids) seems nonessential; and (3) the C-terminal half containing charged amino acids appears to be involved in proper hol function. These results suggest that phi gle Hol is a member of the lambdoid holin family, but divergent in several properties from lambda holin.

Amino Acid Sequence↗
PubMed1997

Genome structure of the Lactobacillus temperate phage phi g1e: the whole genome sequence and the putative promoter/repressor system.

The complete genome sequence of a Lactobacillus temperate phage phi g1e was established. The double-stranded DNA is composed of 42,259 bp, and encodes for sixty-two possible open reading frames (ORF) as well as several potential regulatory sequences. Based on comparative analysis with other related proteins of the Lactobacillus and Lactococcus phages as well as the Escherichia coli phages (such as lambda), functions were putatively assigned to several phi g1e ORFs: cng and cpg (encoding for repressors), hel (helicase), ntp (NTPase), and several ORFs (e.g., minor capsid proteins). An about 1000-bp DNA region of phi g1e containing cpg and cng was inferred to function as a promoter/repressor system for the phi g1e lysogenic and lytic pathway.

Amino Acid Sequence↗
PubMed1997

Characterization of the genes encoding integrative and excisive functions of Lactobacillus phage øg1e: cloning, sequence analysis, and expression in Escherichia coli.

øg1e is a temperate phage of the Lactobacillus strain G1e. The phage-host junctions attR and attL cloned from the lysogen have a 24-bp common (core) sequence implicated in recombination. DNA sequencing analysis of a 5.2-kbp SacI fragment of the øg1e phage genome (42.5 kbp) revealed two possible open reading frames (ORF), xis and int, and the phage attachment (recombination) site (attP), whose 24-bp sequence is identical to the core sequence detected in attR and attL. The deduced int product (Int) is a basic protein of 391 amino acids with an estimated pI of 9.70, and significantly resembles other presumed integrases encoded by the Lactobacillus and Lactococcus phages including øadh and øLC3, as well as the Escherichia coli phages such as lambda. The predicted øg1e xis protein (Xis) is small and very acidic (66 amino acids; pI 4.55), and shows a resemblance (32% overall identity) with a putative excisionase encoded by the Staphylococcus phage ø11. The øg1e Int with a deduced molecular mass of 45.5 kDa was overproduced in E. coli cells, and electrophoretically analyzed.

Amino Acid Sequence↗
PubMed1997

MRI findings of VIIth cranial nerve involvement in sarcoidosis.

Right facial nerve palsy in a 58-year-old woman was due to sarcoidosis demonstrated by Gd-DTPA enhanced MRI. Abnormal enhancement of the right VIIth cranial nerve in the distal internal acoustic canal was seen on MRI. The enhancing lesion was smaller after 1 month of prednisolone 50 mg day-1. This is the first report on facial nerve involvement in neurosarcoidosis examined by Gd-DTPA enhanced MRI. The use of Gd-DTPA enhanced MRI with thin slicing, e.g. 3 mm slice thickness and 1 mm interslice gap, is effective in detecting small extramedullary lesions.

Contrast Media↗
PubMed1996

Cloning, sequence analysis, and expression of the genes encoding lytic functions of Bacteriophage phi g1e.

The lysis genes of a Lactobacillus phage phi g1e were cloned, sequenced, and expressed in Escherichia coli. Nucleotide sequencing of a 3813-bp phi g1e DNA revealed five successive open reading frames (ORF), Rorf50, Rorf118, hol, and lys and Rorf175, in the same DNA strand. By comparative analysis of the DNA sequence, the putative hol product (holin) has an estimated molecular weight is 14.2 kDa, and contains two potential transmembrane helices and highly charged N- and C-termini, resembling predicted holins (which are thought to be a cytoplasmic membrane-disrupting protein) encoded by other phages such as mv1 from Lactobacillus bulgaricus, phi adh from Lactobacillus gasseri, as well as monocins from Listeria. On the other hand, the putative phi g1e lys product (lysin) of 48.4 kDa shows significant similarity with presumed muramidase, known as a cell wall peptidoglycandegrading enzyme, encoded by the Lactobacillus phage mv1 and phi adh, the Lactococcus lactis phage phi LC3, and the Streptococcus pneumoniae phages Cp-1, Cp-7 and Cp-9. When expressed in E. coli, the phi g1e lysin and/or holin decreased the cell turbidity significantly, suggesting that the phi g1e hol-lys system is involved in cytolytic process.

Amino Acid Sequence↗
PubMed1996

Cloning and nucleotide sequence of the major capsid proteins of Lactobacillus bacteriophage phi gle.

Bacteriophage phi gle was induced from a lysogenic Lactobacillus strain Gle. phi gle genome is double-stranded DNA of approximately 42.5 kilo-base (kb) pairs. SDS poly-acrylamide gel electrophoresis demonstrated that the phage particles contain 4 major structural (capsid) proteins, gpB, gpG, gpO, and gpP, whose molecular weights (MW) are estimated to be 64, 43, 29 and 26 kilodaltons (kDa), respectively. More than 16 minor proteins ranging from 113 to 9.6 kDa were also detected. The genes for the major capsid proteins were cloned and each DNA sequence was determined. N-terminal amino acid alignments determined by protein sequencing completely coincided with those deduced from the nucleotide sequences.

Amino Acid Sequence↗
PubMed1996

The virion proteins encoded by bacteriophage phi K and its host-range mutant phi KhT: host-range determination and DNA binding properties.

The microvirid phage phi K, specific for Escherichia coli K12, contains a circular single-stranded (SS) DNA in the icosahedral virion, which comprises four phage gene products, F (capsid), G (major spike), H (minor spike), and J (core). phi KhT, a host-range mutant of phi K, can grow on E. coli C and B, besides K12, and is more thermosensitive than the parental phage phi K. Sequencing analysis revealed that the genome of phi K and phi KhT consists of 6,089 nucleotides (nt), and codes for eleven genes, whose sequences are similar to those of alpha 3, phi X174, and G4 infective to strain C. In phi KhT, two nt had changed: one is in the gene G, resulting in replacement of the 75th codon Ala with Ser, and the other is at 67th codon of the gene H: Val to Ala. Chemically synthesized gene J protein composed of 23 amino acids (aa) binds to phi K SS DNA more tightly than and preferentially over the host E. coli SS-DNA-binding protein (SSB). These results indicate that the two spike proteins G and H are involved in the determination of phi K host-range, and support a model in which the gene J protein functions in packaging the viral SS DNA into the virion vesicle.

Amino Acid Sequence↗
PubMed1995

Determination of the single strand origin of Shigella sonnei plasmid pKYM.

The Shigella sonnei plasmid pKYM replicates by a rolling-circle mechanism in Escherichia coli. A 571 nucleotides HincII restriction fragment of the pKYM DNA harbors two potential hairpin loops (I and II). We cloned the fragment into a -ori defective M13 vector phage, M13 delta lac183. The chimera phage, MDKY5, showed a larger plaque size, and increased phage yield and rate of progeny replicative form DNA (RF) synthesis. Rifampicin reduced rate of conversion of the single- to double-stranded RF DNA. In addition, we introduced nucleotide deletions within the cloned pKYM DNA, by Bal31 nuclease digestion. Each of the deletion mutants thus constructed was lacking in a sequence containing the hairpin loops and formed smaller plaques. The in vivo analyses revealed that a 136 nucleotides sequence containing the two hairpins I and II is the pKYM minus origin for complementary strand synthesis (single strand origin, referred to as SSO) and harbors a recognition site(s) by host E. coli RNA polymerase, for primer RNA synthesis. Moreover, we found a 24 nt sequence, upstream of the SSO domain having 83% homology to the recombination site A (RSA) which functions in plasmid sitespecific recombination and/or transfer.

Base Sequence↗
PubMed1994

Distribution of extrinsic enkephalin-containing nerve fibers in the rat rectum and their origin in the major pelvic ganglion.

The distribution of nerve fibers containing enkephalin (ENK)-like immunoreactivity was examined in the rectum of aganglionosis rats (AGRs) which completely lack the intramural ganglion cells in the large intestine, and was compared with that of their normal littermates. Furthermore, Met5-enkephalin-Arg6-Gly7-Leu8 (MEAGL)-like immunoreactive neurons projecting to the rectum were examined using retrograde tracing combined with immunohistochemistry in the major pelvic ganglion of normal male rats. In the intermuscular space of the aganglionic rectum of AGRs, unlike the pattern of the normal intermuscular plexus, moderate numbers of ENK-like-immunoreactive fibers were arranged in an irregular, coarse network; greatly diminished numbers of immunoreactive fibers were found in the submucosa. No ENK-like-immunoreactive fibers were seen in the circular muscle layer and mucosa. In the normal rat rectum, ENK-like-immunoreactive fibers were seen throughout all layers, and immunoreactive nerve cells were found predominantly in the myenteric plexus of colchicine-treated animals. Fluoro-Gold injected into the upper rectum labelled numerous principal ganglion neurons in the major pelvic and inferior mesenteric ganglia. Less than 10% of tracer-labelled neurons were positive for fluorescein immunolabelling of MEAGL in the major pelvic ganglion; no immunoreactive neurons were found in the inferior mesenteric ganglion. In the major pelvic ganglion of the colchicine-treated normal rats, about 5% of principal ganglion neurons were immunoreactive for MEAGL. Comparison of serial paraffin sections of the major pelvic ganglion stained for tyrosine hydroxylase (TH), MEAGL and vasoactive intestinal polypeptide (VIP), respectively, revealed that more than half of MEAGL-like immunoreactive neurons were also positive for TH; there was no case showing co-existence of MEAGL with VIP in the principal neurons. These results indicate that a small number of enkephalin-containing neurons in the major pelvic ganglion project to the rectum, and that more than half of these neurons are postganglionic sympathetic. They may terminate mainly in the myenteric ganglia in the rectum.

Animals↗
PubMed1994

Coexistence of vasoactive intestinal polypeptide and neuropeptide Y immunoreactivity within axon terminals in the canine and human lower esophageal sphincter: electron microscopy by a double immunogold labeling procedure.

Subcellular localization of vasoactive intestinal polypeptide (VIP) and neuropeptide Y (NPY) immunoreactivity within nerves was investigated in the lower esophageal sphincter of dogs and humans by double immunogold staining of sections prepared for electron microscopy. Coexistence of VIP and NPY immunoreactivity was clearly demonstrated in the large granular vesicles (LGVs) in axon terminals that were closely associated with the smooth muscle cells, as well as in the LGVs within the perikarya of neurons located in the myenteric plexus. Some LGVs appeared immunopositive only for VIP or NPY. This phenomenon might have been partly due to the fact that the double-labeling procedure with immunogold particles of different sizes was performed on both faces of each section. The results obtained in this study suggest that VIP and NPY are synthesized in the same neuron, stored in the same axon terminal, and released together to act on sphincter muscle cells.

Animals↗
PubMed1994

The mechanism of arachidonic acid release in collagen-activated human platelets.

The mechanism of arachidonic acid (AA) release in collagen-activated human platelets was studied. An arachidonic acid metabolite, thromboxane B2 (TXB2), was formed in parallel with the formation of phosphatidic acid (PA) without formation of lysophosphatidic acid (lysoPA) or lysophosphatidylinositol (lysoPI) in the absence of extracellular Ca2+, suggesting that AA was released from PI via a PI-specific phospholipase C (PI-PLC)/diacylglycerol (DG) lipase/monoacylglycerol (MG) lipase pathway under the cytosolic low Ca2+ concentrations. Moreover, solubilized DG lipase and MG lipase could hydrolyze the substrates at basal cytosolic free Ca2+ concentrations. Subsequently, the relationship of cytosolic free Ca2+ concentrations and formation of AA metabolites was analyzed using Ca2+ ionophore, A23187. Collagen was able to induce a release of small amounts of AA under basal cytosolic Ca2+ conditions. However, a release of large amounts of AA was induced by phospholipase A2 activated by both collagen-receptor occupancy and elevated Ca2+ levels. A TXA2 mimetic agonist, STA2 induced all the responses except for AA release. From these results, the mechanism of AA release and signal transduction in collagen-activated human platelets is discussed.

Arachidonic Acid↗
PubMed1994

[Clinical treatment of urinary tract stones with Alexandrite laser].

Clinical treatment of urolithiasis with Alexandrite-laser which is a solid pulse laser system developed in Switzerland is reported. Two cases of renal stones, 3 cases of vesical stones, and 35 renal units in 34 cases of ureteral stones were treated. The approach to the aimed stone was, percutaneous to the renal stones, and transurethral to the vesical and ureteral stones. The clinical success rate was 92.5% (37/40), when we defined success as the endoscopically observed fragmentation. The uric acid stone in the bladder was not disintegrated even when the plasma occurred, but the ureteral uric acid stone was easily fragmented. The difference was thought to be attributed to the condition of the surface. The Alexandrite-laser system generates a 750 nm wavelength, and this wavelength is neither absorbed in water nor hemoglobin, so is thought to be harmless to the tissue. Actually, if misirradiation to the ureteral mucosa during lithotripsy was done, neither plasma formation nor perforation occurred. In conclusion, the Alexandrite-laser is thought to be safe and effective equipment for the treatment of urolithiasis.

Adult↗
PubMed1993

[Clinical analysis of surgical treatment of benign prostatic hypertrophy patients over 80 years old].

We compared several clinical parameters between two different prostatectomy procedures, transurethral prostatectomy (TUR-P, 26 cases) among aged cases of benign prostatic hypertrophy. All patients were over 80 years old and were treated at Nippon Medical School Hospital from January 1983 to December 1988. TUR-P was superior to open prostatectomy in the following aspects, (1) operation time, (2) total amount of transfused blood and (3) hospital stay.

Aged↗
PubMed1993

[Clinical application of transrectal ultrasonic therapy to nonbacterial prostatitis and prostatodynia cases which were resistant to conventional drug therapy].

A total of 25 patients with nonbacterial prostatitis and prostatodynia which were resistant to conventional drug therapy underwent 5 minutes course of transrectal ultrasonic therapy in association with application of 1% hydrocortisone acetate cream to the anterior rectal wall for consecutive 8 days. The efficacy of the treatment was evaluated only by comparison of symptom scores for subjective symptoms obtained before and after treatment. Excellent results, which were defined as more than 70% reduction of symptom scores after treatment, were obtained in 5 (27.8%) among 18 evaluable cases in which symptom scores before treatment were more than 4, good (40-69% reduction of scores) in 4 (22.2%), fair (10-39% reduction of scores) in 4 (22.2%) and poor (less than 10% reduction of scores) in 5 (27.8%). Because of good clinical efficacy and the absence of complication, transrectal ultrasonic therapy combined with hydrocortisone acetate cream application was thought to be useful for the treatment of nonbacterial prostatitis and prostatodynia cases which responded poorly to the conventional therapy.

Administration, Topical↗
PubMed1992

Heterogenous distribution of peptide-containing nerve fibres within the circular muscle layer of the human pylorus.

The distribution of nerve fibres immunoreactive for vasoactive intestinal polypeptide (VIP), substance P (SP), methionine-enkephalin (ENK), calcitonin gene-related peptide (CGRP) and neuropeptide Y (NPY) within the circular muscle layer was examined histochemically in the human pylorus, adjacent antrum and duodenum. Longitudinal cryostat sections of the pyloric and surrounding regions were stained by an indirect immunofluorescence method, and the total length of each type of peptide-containing fibre per unit sectional area (micron/mm2) was measured using an image-analysing system. The narrow region of the circular muscle layer bordering the submucosa in the pylorus contained a rich supply of VIP, SP, ENK and CGRP immunoreactive fibres; VIP fibres were most prominent with less SP and ENK fibres and moderate amounts of CGRP. These peptide-containing nerve fibres were more dense than in the pyloric circular muscle, the longitudinal muscle layer and also the adjacent muscle layer. NPY-immunoreactive fibres were sparsely distributed throughout the pyloric region. These results suggest that the inner edge of the circular muscle, lying adjacent to the submucosa and densely innervated with peptide-containing fibres, may be a characteristic feature of the human pyloric sphincter.

Adult↗
PubMed1992

Distribution and origin of extrinsic nerve fibers containing calcitonin gene-related peptide, substance P and galanin in the rat upper rectum.

The distributions of nerve fibers containing calcitonin gene-related peptide (CGRP), substance P (SP) and galanin (GAL) were examined in the rat rectum of mutants rats, aganglionic rats (AGRs), which completely lack the intramural nerve cells in the large intestine, and of their normal littermates. The origin of extrinsic peptide-containing nerve fibers was examined using retrograde tracing combined with immunohistochemistry in normal rats. In the rectum of normal rats, CGRP-, SP- and GAL-immunoreactive varicose fibers were observed throughout all layers of the rectal wall, and immunoreactive nerve cells were present in the enteric ganglia of colchicine-treated rats. In the aganglionic rectum of AGR, a rich supply of CGRP-immunoreactive fibers was observed in the mucosa, around the blood vessels, and in the submucous and intermuscular spaces. SP- and GAL-immunoreactive fibers in the aganglionic rectum showed a similar distribution to CGRP-immunoreactive fibers but were less dense. These results suggest that most of CGRP-positive fibers in the rectum are extrinsic whereas a large part of SP- or GAL-positive fibers are intrinsic. Fluoro-gold injected into the upper rectum of normal rat labelled nerve cells (less than 10% of total ganglion cells) in the lumbar (L1 and L2) and lumbosacral (L6 and S1) dorsal root ganglia. More than half of nerve cells in the dorsal root ganglia (L6 and S1) projecting to the rectum were immunoreactive for CGRP, and less than 10% were immunoreactive for SP or GAL. Comparison of serial sections of the dorsal root ganglion revealed that about half of the CGRP-immunoreactive cells were also positive for SP or GAL. These results indicate that SP- or GAL-positive neurons projecting to the rectum are scarce in the dorsal root ganglia. The present investigation suggests that CGRP-containing nerves are visceral afferents forming a major component of the sensory innervation of the rat rectum, and SP- and GAL-containing nerves which share their extrinsic origins appear to form a lesser proportion of the sensory innervation.

Animals↗
PubMed1991

Distribution of cholinergic and catecholaminergic nerves in the colon of the rat with aganglionosis.

We compared localization and distribution of putative cholinergic fibers by acetylcholinesterase and of adrenergic fibers visualized by the glyoxylic acid technique in the aganglionic segment using whole mount preparations of aganglionosis rat (AGR) and compared them with those of normal littermates. We also attempted simultaneous staining of acetylcholinesterase (AChE) and catecholamine fluorescence (C-F) on the same whole mount preparations to compare the differences in distribution pattern. All AGR used in this study had narrowed segments of the bowel extending from the distal ileum to the anus, and had no ganglion cells in these narrowed segments. In the intermuscular space, normally occupied with myenteric ganglion, of the narrowed distal colon and rectum, various sizes of nerve bundles and fibers reactive for AChE and C-F appeared to make coarse and irregular networks. These thick nerve bundles appeared to ascend to the proximal colon and disappeared in the cecum. In the distal ileum, almost totally absence of AChE positive nerve fibers, but a few fine C-F fibers, probably associated with blood vessels, were observed. By the method of simultaneous staining of AChE and C-F method in the whole mount preparations, the thick nerve bundles in the narrowed segments showed both of AChE positive and C-F positive. However, there were differences in peripheral fine nerve fibers in the segment; especially numerous perivascular C-F positive nerve fibers, but a few AChE positive ones were found. In the upper aganglionic narrowed segments, greatly diminished numbers of AChE positive and C-F positive nerve fibers were found in the circular muscle layer and in the submucosal layer. In the lower aganglionic narrowed segments, there were thick nerve bundles, forming irregular interlaced network. The role of these extrinsic nerve fibers in aganglionic segments is unclear.

Acetylcholinesterase↗