Biomedical subjects

M Iwanaga

Publications and source records attributed to M Iwanaga.

At least 91 records · Page 5Linked to original sources

PubMed1992

The role of pili in colonization of the rabbit intestine by Vibrio parahaemolyticus Na2.

Vibrio parahaemolyticus Na2 and its pili were studied in relation to intestinal colonization. The isolated pili were adhesive to the intestinal epithelium. The adhesion of the organisms was blocked by masking the epithelial receptor with the purified pili, or by treating the organisms with anti-pilus antibody (Fab fraction). These results suggest that the pili of V. parahaemolyticus Na2 play an important role in the adhesion of the organisms to the rabbit intestine.

Animals↗

PubMed1992

Simultaneous expression of T-cell and myeloid cell phenotypes in eight newly established HTLV-I-positive T-cell lines.

Eight cell lines were established from patients with adult T-cell leukemia, and from normal adults, by cocultivation with human T-cell leukemia virus type I(HTLV-I)-producer cell lines in the presence of interleukin-2. All of these cell lines harbored HTLV-I and showed T-cell markers CD2, CD3 and CD4, but not B-cell markers. Unexpectedly, all eight cell lines expressed a myeloid marker CD13 and three of the eight lines also expressed another myeloid marker CD33. Dual staining showed the simultaneous expression of CD3 and CD13 on the same cells. Thus, evidence was obtained for the expression of myeloid antigens on HTLV-I-harboring T cells.

Adult↗

PubMed1992

Requirement for specific protein kinase activities during the rapid redistribution of F-actin that precedes the outgrowth of neurites in PC12D cells.

Rapid changes in morphology of PC12D cells, a subline of PC12 cells, in response to various agents were studied in relation to the subsequent outgrowth of neurites. A few minutes after addition of NGF or of dbcAMP, staining of F-actin with rhodamine phalloidin revealed the formation of ruffles around the periphery of cells. Simultaneous relocalization of F-actin to the area of ruffles occurred in response to NGF. A moderate relocalization of F-actin occurred in dbcAMP-treated cells. Other neurite-promoting agents on PC12D cells, such as bFGF, EGF and PMA, also caused ruffling and an identical redistribution of F-actin. The actin bundles then condensed into several dot-like aggregates that subsequently became the growth cones of neurites. When an inhibitor of protein kinase, K-252a, was added, only the NGF-induced morphological change was selectively decreased. By contrast, an inhibitor of protein kinase A, H-89, selectively blocked the dbcAMP-induced change. These are analogous to the effects of those inhibitors on the outgrowth of neurites. These observations indicate that the formation of ruffles with the redistribution of F-actin might be one of the earliest steps in the neurite outgrowth and that the morphological changes might be triggered by the activation of specific protein kinases. Neither cytochalasin B nor colchicine prevented the series of morphological changes. However, processes formed in the presence of cytochalasin B had no filopodium and protrusions formed in the presence of colchicine were shaped like large filopodia. It appears that microtubules and microfilaments may not be absolutely required for the initiation of the rapid morphological changes, but that complete neurites might be formed with contribution by microtubules and by microfilaments.

Actins↗

PubMed1992

Age-related prevalence of Strongyloides stercoralis infection in Okinawa, Japan.

Age-prevalence of Strongyloides stercoralis infection was studied in six areas of Okinawa, Japan. In all localities, most of the infected inhabitants were aged over 40 years of age and females were less infected than males. The peak prevalence was found in inhabitants in their fifties in high endemic groups and shifted to higher age in lower endemic groups. This age-prevalence pattern resembles more that of schistosome infections than that of other gastrointestinal helminthic infections.

Adolescent↗

PubMed1992

Is the prevalence of HTLV-1 infection higher in Strongyloides carriers than in non-carriers?

To assess the concomitance of strongyloidiasis and HTLV-1 infection, an epidemiological survey was conducted in Okinawa, Japan, using the agar-plate culture, a highly sensitive method for detection of Strongyloides stercoralis. No significant difference in the positive rate of anti-HTLV-1 antibody was found between Strongyloides carriers and non-carriers. This result suggests that these two infections occur independently.

Adolescent↗

PubMed1992

Epidemiological aspects of Strongyloides stercoralis infection in Okinawa, Japan.

The epidemiology of Strongyloides stercoralis infection was compared among three localities with various prevalences of human T lymphotropic virus type 1 (HTLV-1) infection in Okinawa Prefecture, Japan, using agar-plate culture of faeces. The prevalence of S. stercoralis infection is much higher in Gusukube, where HTLV-1 infection is rare, than in Yomitan, where this viral infection is common. In all localities the parasite prevalence is significantly higher in males than in females, whereas the prevalence of HTLV-1 infection is much higher in females. These epidemiological facts suggest that infection by S. stercoralis occurs independently of that by HTLV-1.

Adolescent↗

PubMed1991

Remnants of urachus in infants and children--the problems of diagnosis and treatment.

A total of 17 cases of remnants of urachus were examined between 1981 and 1989, including 2 cases of patent urachus, 5 of urachal cyst, 9 of urachal sinus, and 1 of urachal diverticulum. A long urachal sinus was considered to be caused by the self-destruction of a cyst. While patent urachus was diagnosed in neonates with urine discharge from the umbilicus, cysts or sinuses accompanied by infection were more often found in older children. Imaging of the burrows was diagnostic in 8 out of 11 cases, ultrasound examination in 9 out of 12, and CT examination in all of 3 cases. Since this condition is frequently accompanied by malformations of the urinary system, attention must be paid to locating the accompanying anomalies. Although primary extraction was performed in 13 cases, the primary treatment of cases with highly infected cysts should be drainage, followed by secondary extraction. Furthermore, caution must be exercised to avoid hemorrhage in cases with dilation of the umbilical artery.

Child↗

PubMed1991

Conductive hearing loss with normal tympanic membrane: fibrous change of long process of the incus.

This is a case of conductive hearing loss with the normal tympanic membrane due to fibrosis caused by potential inflammation of the long process of the incus. High resolution CT was a useful tool for the detection of ossicular disorder.

Adult↗

PubMed1991

An aberrant hemolysin of Vibrio cholerae non-O1.

An aberrant hemolysin produced by a Vibrio cholerae non-O1 strain N037 (N037-hly) was purified and characterized. N037-Hly was antigenically very similar to El Tor hemolysin but differed in molecular weight (48,000 vs. 60,000), interaction with glucose, and hemolytic activity. Of 100 V. cholerae non-O1 strains other than the N037 strain examined, none produced this aberrant hemolysin. The N-terminal amino acid sequence of N037-hly was highly homologous to that of El Tor hemolysin.

Amino Acid Sequence↗

PubMed1991

[Influence of low level antibiotics on Pseudomonas aeruginosa].

Erythromycine (EM) and chrolamphenicol (CP), the inhibitors of protein synthesis, were quantitatively examined for the growth of Pseudomonas aeruginosa EA83 and its production of extracellular proteins. The minimal inhibitory concentration (MIC) of EM for the strain was higher than 100 micrograms/ml and that of CP was 100 micrograms/ml. The growth curve of EA83 was not influenced by adding 5 micrograms/ml of EM to the broth culture, but proteolytic activity and the total protein in the culture supernate went down to 60% of the control. Number of organisms in 20 hour culture was almost constant regardless of EM concentration ranging from 0 to 50 micrograms/ml, however, the suppression of proteolytic activity and total protein in the culture supernate was seen even at 1 micrograms/ml of EM concentration. The degree of suppression was inversely proportional to EM concentration. This phenomenon was also seen in the substitution of CP for EM. All extracellular proteins separated on SDS-PAGE decreased the amount as increasing EM in the culture media. These results suggested that EM inhibited the production of not only protease including elastase, but also any other extracellular proteins including well known pathogenic factors such as exotoxin A and phospholipase C.

Chloramphenicol↗

PubMed1991

Purification and characterization of Aeromonas sobria pili, a possible colonization factor.

Pili of Aeromonas sobria Ae1 were purified and characterized. The molecular mass of the pilin was estimated to be about 23 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The Ae1 pili were electrophoretically and immunologically distinguishable from the W pili of A. hydrophila Ae6, although the two pili were morphologically indistinguishable. The N-terminal amino acid sequences of the two pilins were identical in the first 10 residues. Strain Ae1 and its purified pili adhered to human and rabbit intestines and agglutinated human and rabbit erythrocytes. Hemagglutination was inhibited by D-galactose and D-mannose, but not by L-fucose. Organisms pretreated with the Fab fraction of the antipilus antibody failed to adhere to the intestines. Organisms did not adhere to intestines pretreated with the purified pili. These findings suggest that the pili are a colonization factor of A. sobria Ae1.

Aeromonas↗

PubMed1991

Purification and characterization of pili isolated from Vibrio parahaemolyticus Na2.

Pili from Vibrio parahaemolyticus Na2 isolated from a patient with diarrhea were purified and characterized. The organisms were hemagglutinative, but the purified pili were not. Na2 pili were physicochemically and immunologically quite different from the previously described V. parahaemolyticus Ha7 pili. Nevertheless, there was a high degree of homology between their N-terminal amino acid sequences.

Amino Acid Sequence↗

PubMed1990

Sinus histiocytosis with massive lymphadenopathy in a Japanese male with symptoms of dyspnea and visual disturbance.

A case study of sinus histiocytosis with massive lymphadenopathy is reported. A Japanese male developed lymphadenopathy in the nasal cavity 10 years ago. Biopsy specimens demonstrated massive histiocytosis with phagocytosis of lymphocytes, plasmacytes, and erythrocytes. During the course of his illness, the patient experienced an episode of massive nasal bleeding, and a tracheotomy was performed because of dyspnea. He had also an operation by Killian's approach to relieve a visual disturbance. The patient has been treated with cyclophosphamide and prednisolone for 6 months.

Adult↗

PubMed1990

[Preventive effect of Clostridium butyricum M588 against the proliferation of Clostridium difficile during antimicrobial therapy].

Fecal flora of the patients without remarkable gastrointestinal diseases were studied. All patients were treated with antimicrobial drugs with or without Miya-BM (the preparation of Clostridium butyricum M588). The stools were examined before and after (during) antimicrobial treatment. Fecal flora of 69 patients before medication was almost the same with that of healthy adults as has been reported by Mitsuoka et al. After giving antimicrobials, most bacterial genus except Enterococcus and Yeasts in the stool decreased their detection rate and their population. This floral change was not much influenced by co-administration of Miya-BM. The detection rate of Clostridium difficile and/or the toxin A from the stool were markedly increased after giving antimicrobials. When Miya-BM was co-administered with antimicrobials, however, the detection of C. difficile and/or toxin A was very rare. C. butyricum M588 was recovered from 7 cases out of 10 patients treated with antimicrobials and Miya-BM. Non-spore form of C. butyricum was dominant in the feces of 3 cases, and spore form was dominant in the other 4. This result showed that administered C. butyricum M588 germinated in intestinal tract.

Adolescent↗

PubMed1990

[Inhibition of enteropathogens by Clostridium butyricum MIYAIRI 588].

The inhibitory effect of Clostridium butyricum MIYAIRI 588 against various enteropathogens was investigated in mixed cultures. It was observed that C. butyricum M588 inhibited the growth of Vibrio cholerae O1, V. cholerae non-O1, Aeromonas hydrophila, and Shigella flexneri. Considering that the interaction between C. butyricum and Shigella is especially important because of their proliferation site in the lower intestine, further examinations were carried out on Shigella in particular. Results were as follows: 1) In BHI broth culture of Shigella, the pH of culture fluid went down to 5.2, but the growth of Shigella was not inhibited. 2) In the mixed culture of Shigella and C. butyricum, the growth of Shigella was inhibited, nevertheless the pH of the culture fluid was 5.6. 3) In the mixed culture with phosphate buffered BHI maintaining the pH higher than 6.0, the growth of Shigella was inhibited. 4) In case of pure culture of C. butyricum in BHI broth, the pH of culture fluid indicated 5.5, and Shigella failed to grow in the cell free culture supernatant. 5) The growth of Shigella was not inhibited in the culture supernatant when the pH was adjusted at 7.2. These results suggested that the inhibition of Shigella in the mixed culture with C. butyricum was not due to a single factor such as pH or fatty acid etc. but due to multifactors including live cells of C. butyricum.

Antibiosis↗

PubMed1990

Pili of a Vibrio parahaemolyticus strain as a possible colonization factor.

Pili of Vibrio parahaemolyticus were purified from a Kanagawa phenomenon-positive strain (Ha7) that belongs to serogroup O2:K3 and is adhesive to rabbit intestine. The organisms treated with the Fab fraction of antipilus antibody failed to adhere to the intestine. Purified pili had the ability to adhere to the intestine, but the pretreatment of the intestine with purified pili did not allow adherence of the organisms to the intestine. These results suggest that pili of this V. parahaemolyticus strain play an important role in colonization.

Animals↗

PubMed1990

Two-step processing for activation of the cytolysin/hemolysin of Vibrio cholerae O1 biotype El Tor: nucleotide sequence of the structural gene (hlyA) and characterization of the processed products.

Vibrio cholerae O1 biotype El Tor produces and secretes a 65-kDa cytolysin/hemolysin into the culture medium. We cloned the structural gene (hlyA) for the cytolysin from the total DNA of a V. cholerae O1 El Tor strain, N86. Nucleotide sequence analysis of hlyA revealed an open reading frame consisting of 2,223 bp which can code for a protein of 741 amino acids with a molecular weight of 81,961. Consistent with this, a 79-kDa protein was identified as the product of hlyA by maxicell analysis in Escherichia coli. N-terminal amino acids of this 79-kDa HlyA protein and those of a 65-kDa El Tor cytolysin purified from V. cholerae were Asn-26 and Asn-158, respectively. The 82- and 79-kDa precursors of the 65-kDa mature cytolysin were found in V. cholerae by pulse-chase labeling and Western blot (immunoblot) analysis of hlyA products. Hemolytic activity of the 79-kDa HlyA protein from E. coli was less than 5% that for the 65-kDa cytolysin from V. cholerae. Our results suggest that in V. cholerae, the 82-kDa preprotoxin synthesized in the cytoplasm is secreted through the membranes into the culture medium as the 79-kDa inactive protoxin after cleavage of the signal peptide and is then further processed into the 65-kDa active cytolysin by release of the N-terminal 15-kDa fragment.

Amino Acid Sequence↗

PubMed1990

Pili of Vibrio cholerae non-O1.

Pili of Vibrio cholerae non-O1 strain S7 were purified and characterized. The pili of S7 were morphologically, electrophoretically, and immunologically (as far as polyclonal antibody was used) indistinguishable from the 16-kilodalton pili of V. cholerae O1 strain 82P7. The purified pili and organisms had D-mannose- and L-fucose-resistant hemagglutinin. The hemagglutinating activity of the purified pili was inhibited by the Fab fraction of antipilus antibody, but the hemagglutinating activity of live organisms was not inhibited completely. The purified pili or Fab fraction of antipilus antibody did not inhibit the adhesion of V. cholerae non-O1 to rabbit intestines. Therefore, the pili were not regarded as a colonization factor of V. cholerae non-O1. A total of 148 V. cholerae non-O1 and O1 clinical isolates were screened for the presence of S7 pili by using an agglutination test with anti-S7 pilus serum; 12 of 49 V. cholerae non-O1 strains and 25 of 99 V. cholerae O1 strains were positive for agglutination. These agglutination reactions were not correlated with adhesion of the organisms to intestines.

Animals↗