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S Ihara

Publications and source records attributed to S Ihara.

At least 73 records · Page 4Linked to original sources
PubMed1992

cDNAs and deduced amino acid sequences of subunits in the binding component of mouse bactericidal factor, Ra-reactive factor: similarity to mannose-binding proteins.

The complement-dependent bactericidal factor, Ra-reactive factor, binds specifically to Ra polysaccharide, which is common to some strains of Gram-negative enterobacteria, and its is a complex of proteins composed of a polysaccharide-binding component and a component that is presumably responsible for the complement activation. The former component consists of two different 28-kDa polypeptides, P28a and P28b. We determined the partial amino acid sequences of P28a and P28b, and the results indicated that these polypeptides were similar to two species of mannose-binding protein, MBP-C and MBP-A (alternative names, liver and serum mannan-binding proteins, respectively), which have been isolated from rat liver and/or serum [Drickamer, K., Dordal, M. S., & Reynolds, L. (1986) J. Biol. Chem. 261, 6878-6887; Oka, S., Itoh, N., Kawasaki, T., & Yamashina, I. (1987) J. Biochem. 101, 135-144]. Thus, we cloned the respective cDNAs, using as probes synthetic oligonucleotides for which the sequences had been deduced from the amino acid sequences of P28a and P28b and of rat MBP cDNAs. The primary structures of P28a and P28b deduced from the cloned cDNAs are homologous to one another. They have three domains, a short NH2-terminal domain, a collagen-like domain, and a domain homologous to regions of some carbohydrate-binding proteins, as has been reported for rat MBPs. Southern and Northern blotting analyses using these cDNAs indicated that the P28a and P28b polypeptides are the products of two unique mouse genes which are expressed in hepatic cells.

Amino Acid Sequence↗
PubMed1992

Analysis of pathogenicity by restriction-endonuclease digestion of amplified genomic DNA of Entamoeba histolytica isolated in Pernambuco, Brazil.

The pathogenicity of 47 strains of Entamoeba histolytica isolated in Pernambuco, Brazil, was examined using the polymerase chain reaction (PCR) followed by restriction-endonuclease digestion. Electrophoretic patterns of PCR products digested with HinfI revealed that all strains were nonpathogenic. The results were entirely in accord with phenotypic properties such as isoenzyme patterns and the failure to bind a pathogenic-isolate-specific monoclonal antibody. When the sensitivity of PCR was examined, amplified products could be detected from template DNA equivalent to five trophozoites. These observations indicate that PCR amplification of genomic DNA and subsequent restriction-enzyme digestion is a useful strategy for obtaining a sensitive and accurate diagnosis. The present study also demonstrates that nonpathogenic strains of E. histolytica predominate in northeastern Brazil.

Animals↗
PubMed1992

Wound closure in foetal rat skin.

Foetal rat skin rapidly closes an open wound in organ culture and in vivo, this possibly being unique to organs still in the morphogenetic stage. In the present study, examination was made of morphological changes in foetal rat skin during closure of open wounds inflicted at day 16 of gestation. Phase-contrast microscopy of open-wounded skin cultured in vitro indicated inward spreading of the peripheral skin to be responsible for wound closure. Wound closure in vitro was inhibited by cytochalasin B (10 micrograms/ml), not by hydroxyurea (2 mM), indicating prenatal wound closure to be mediated by regulation of the microfilament system rather than cell proliferation. During wound closure in vitro and in vivo, light and scanning electron microscopy of the peripheral skin showed cells in the periderm, the outermost layer of the foetal epidermis, to elongate centripetally and en masse, whereas the shape of underlying epidermal cells not to change. Numerous spindle-shaped cells and fibrous matrices in the mesenchyme were redistributed, becoming oriented along the wound edge. Following isolation of the mesenchyme and epidermis by treatment with Dispase and separate culturing, the capacity for wound closure in vitro was found to be retained only by the mesenchyme. Cellular activity within the mesenchyme, rather than in the epidermis, would thus appear essential to wound closure in foetal rat.

Animals↗
PubMed1992

Increased frequency of the heterozygous switch region of IgA2 in Japanese patients with IgA nephropathy.

The relation between IgA hyperproduction and restriction fragment length polymorphism (RFLP) of the immunoglobulin heavy chain switch (S) region was examined in Japanese patients with IgA nephropathy (IgAN) using Southern blot hybridization. Polymorphism in the S regions of IgM, IgA1 and IgA2 (SA2) was detected. A significant increase in the frequency of heterozygous phenotype of SA2 was shown in the patients. These patients showed a significant increase in the amount of serum IgA, IgA bearing cells and levels of proteinuria. Although two reports on RFLP of the S region have been published in Europe, the results differed. A comparison of the three reports showed different frequencies in the phenotype of the S region between Caucasian and Japanese patients. These results suggested that there is heterogeneity at the S region in IgAN patients in various countries and that this polymorphism might be associated with IgA hyperproduction and the development of proteinuria in Japanese patients.

Adult↗
PubMed1992

[The study of pulmonary tuberculosis in the elderly].

A clinical study of 52 patients diagnosed as having pulmonary tuberculosis at National Chiba-Higashi Hospital between 1988 and 1990 was performed. The cases ranged in age from 80-89 years; mean male patient age was 82.5, and mean female patient age was 84.3. Diagnosis of the cases were as follows: 19 discovered when checking into hospital because of chest symptoms; 14 diagnosed during the treatment of other diseases; 14 diagnosed during admission to the hospital for other diseases; and five cases were detected by chest X-rays. A total of 38 cases, had received primary treatment for pulmonary tuberculosis, 11 cases had received secondary treatment, and three cases were receiving treatment for tuberculosis. Upon admission to the hospital after the detection of tuberculosis, 19 cases tested positive to sputum smear examinations, six cases tested positive to culture examinations but negative to smear examinations, and culture examinations were negative in 27 cases. Regarding the chest X-ray findings, using the criterion of roentgenological classification for pulmonary tuberculosis established by the Japanese Society for Tuberculosis, two cases revealed type I, 29 cases revealed type II, and 21 cases revealed type III. Cavitary cases were observed in 60% of the chest X-ray findings. Upon hospital admission, 18 cases were observed to have circulatory diseases, 16 cases had central nervous diseases, 12 cases had digestive diseases and 11 cases had respiratory diseases. Nine cases had malignant neoplasm, five cases had diabetes mellitus and 14 cases had other diseases. A total of 18 cases ended in death; six cases died of pulmonary tuberculosis, and 12 cases died of other diseases.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

Localization of estrogen receptors and estrogen receptor-mRNA in female mouse thymus.

The present study was performed to demonstrate estrogen receptor (ER) and ER-mRNA in female mouse thymus. The results are as follows: (i) thymic tissue contains ER in both reticuloepithelial(RE)- and T-cell fractions, the ER level being three-fold higher in the former fraction than in the latter; and (ii) thymic tissue contains ER-mRNA at 6.2 kb, a large amount of which was localized in the RE cells and less in the T cells. From these results it is suggested that estrogen (E) mediates some immune function of the mouse thymus through its receptor within RE cells and/or T cells.

Animals↗
PubMed1992

[Cases of pulmonary tuberculosis found in the development of pneumothorax].

During the four-year period from 1987 to 1990, six cases of pulmonary tuberculosis, accompanied by the development of pneumothorax, were observed at our hospital. Distribution by sex was five males and one female. The mean age was 49.8 years-old. None of the patients suffered severe respiratory failure, and there were no deaths in this series. While many of the patients had bilateral exudative disease, five out of the six patients experienced pneumothorax on their right side. The realization of tuberculosis by both patients and doctor tended to be shorter than those cases without pneumothorax.

Adolescent↗
PubMed1992

[A suspected case of perforation of a lymph node into the bronchus during the treatment of adult hilar lymph node tuberculosis].

A 27-year old patient was diagnosed as having post-primary hilar lymph node tuberculosis. First being admitted to the hospital with a high fever, a chest x-ray examination revealed a swelling of the left hilar lymph nodes and a sputum smear tested positive for acid-fast bacilli. Neither regular clinical examination or investigation had reported abnormality. The acid-fast bacilli was successfully treated through treatment using INH RFP SM. However, after two months, swelling was observed in the right para-tracheal lymph nodes, Further, a bronchoscopic examination revealed polyp-like tumors at the left upper and lower bifurcation. The swelling of the para-tracheal lymph nodes was considerably reduced and the tumors non-existent after five months. These lymph node reactions could have likely been a part of the so called early exacerbation. The polyp-like tumors were not found during the bronchoscopy performed during admission to the hospital. It is therefore suspected that the cause was perforation of the hilar lymph node into the bronchus.

Adult↗
PubMed1992

[Investigation of the cases due to Mycobacterium kansasii in our hospital].

A clinical study of 23 patients with Mycobacterium kansasii infection of the lung encountered at National Chiba Higashi Hospital from 1988 to 1990 was carried out. All 23 cases were male, aged from 25 to 81 years-old. Diagnoses were confirmed by sputum culture. The cases consisted of 15 primary infections and 8 secondary infections. Out of the 23 cases, 11 were detected by mass screening with chest X-ray findings, 10 cases were discovered when visiting the hospital because of chest complications and two cases were diagnosed during the observation of other diseases. On admission, sputum smear examinations were positive for 15 patients and negative for 8 patients. Chest X-ray findings using the roentgenological classification criterion for pulmonary tuberculosis established by the Japanese Society for Tuberculosis, 20 cases revealed a Type II shadow and three cases revealed a Type III shadow. One patient has died from another disease, two are undergoing chemotherapy, two have ceased chemotherapy treatment, and 18 patients have completed the treatment, Sputum cultures rapidly turned to negative for mycobacterium detection after chemotherapy treatment. The prognosis is considered to be quite good.

Adult↗
PubMed1992

[Pulmonary tuberculosis in youth].

The study of the group younger than 29 years of age with pulmonary tuberculosis was carried out. Thirty seven out of 287 tuberculosis patients who were discharged from National Chiba-Higashi Hospital in 1989 were enrolled. Only 5 patients (13.5%) were associated with complication. The smear and culture of sputum for acid-fast bacilli were positive in 30 cases (81.1%) and chest X-ray films revealed cavitary lesion in 31 cases (83.3%). Many of them were moderately advanced cases. Twenty four of them were found symptomatically, 10 by mass survey and 3 under treatment of other diseases. The total delay of symptomatic patients was 8.5 weeks until 80% of them were definitely diagnosed. The days of hospital stay were 122 until half patients were discharged. Five of them (13.5%) were non-Japanese and all stayed in Japan illegally. Their condition was rather severe.

Adolescent↗
PubMed1991

Site-specific stable insertion into the human cytomegalovirus genome of a foreign gene under control of the SV40 promoter.

On the basis of a previous finding that the 7.8-kb HindIII-O fragment of the human cytomegalovirus strain Towne genome is nonessential for viral replication, we constructed a vector, pKM, that directs introduction of foreign genes by homologous recombination precisely replacing the O fragment. Using this vector, we constructed Towne-strain-derived recombinant virus in which a chimeric lacZ gene fused to the simian virus 40 promoter and a poly(A) signal were inserted in place of the O fragment. Two types of recombinants were obtained which carried the chimeric gene in opposite directions, beta-Galactosidase (beta Gal) was produced throughout the infection cycle in human embryonic lung cells infected with these recombinants, and the rate of its synthesis in the early stages of infection was comparable to that of synthesis of a 65-kDa viral glycoprotein, one of the abundantly produced viral proteins. The chimeric lacZ gene introduced was stable and no lacZ- revertants have been observed so far.

Cell Line↗
PubMed1991

Major component of Ra-reactive factor, a complement-activating bactericidal protein, in mouse serum.

A complement-activating bactericidal protein, Ra-reactive factor was isolated from mouse serum by an affinity method. The m.w. of the isolated RaRF estimated by glycerol density gradient sedimentation (around 300,000) was the same as that of the active material in mouse serum. As evidenced by gel filtration, the intact RaRF was decomposed into high (higher than 200,000) and low (50,000 to 200,000) m.w. components by treatment with 10% acetonitrile. SDS- and acid/urea-PAGE demonstrated that the high m.w. component was completely dissociated into equimolar quantities of two kinds of 28 kDa polypeptides, P28a and P28b, under reducing conditions, indicating that the association of these polypeptides was stabilized by disulfide bonds. The ability to bind specifically to the Ra determinant was retained in the high m.w. component, although the complement-activating potency was lost. The amino acid compositions of P28a and P28b polypeptides were compared with those of related serum proteins. The P28a and P28b polypeptides were found to have the highest homology to rat mannan-binding protein and mouse and human C1q subcomponent of complement.

Amino Acids↗
PubMed1991

Formation of hair follicles from a single-cell suspension of embryonic rat skin by a two-step procedure in vitro.

A technique for culturing skin was devised whereby hair follicles in a normal state were generated from a single-cell suspension of embryonic rat skin. Dissociated cells obtained by trypsinization of the day-15 embryonic lip were cultured by a two-step procedure in vitro. Reorganization of hair-follicle rudiments was accompanied by reaggregation of the cells during a 24-hour initial culture with rotation, and the rudiments differentiated into hair follicles within a week during subsequent subculture of the cell aggregates by floatation. The light-microscopic features and the size of the follicles were similar to those of day-18 vibrissa follicles during normal development in vivo. Furthermore, the stratification of cells, including subcellular differentiation, and the ultrastructure of the hair follicles generated in vitro were similar to those of normal hair follicles with well-keratinized hair shafts. The present system appears to be a useful model for analytical studies in vitro on the formation of hair follicles and for studies designed to facilitate the transplantation of human hair.

Animals↗
PubMed1991

Differences in genomic DNA sequences between pathogenic and nonpathogenic isolates of Entamoeba histolytica identified by polymerase chain reaction.

A lambda gt11 cDNA library was constructed from the poly(A)+ RNA of trophozoites of Entamoeba histolytica HM-1:IMSS strain. The library was immunologically screened with monoclonal antibody 4G6, which is specific for the 30,000-Mr antigen of pathogenic isolates. A 0.7-kb clone was isolated, and its nucleotide sequence was determined. To examine whether this gene was specific for pathogenic isolates, a polymerase chain reaction was performed by using four sets of primers and the genomic DNA of pathogenic and nonpathogenic isolates as templates. Amplified DNAs were detected not only in pathogenic isolates but also in nonpathogenic isolates. However, when sequences of amplified DNA of these isolates were compared, minor differences were observed. By considering the presence or absence of recognition sites of some endonucleases, it was possible to distinguish between the pathogenic and nonpathogenic isolates. When various isolates with different zymodemes were examined by polymerase chain reaction and enzyme digestion, the results of typing were entirely in accord with those of zymodeme analysis. These results indicate that there is dimorphism in the genomic DNA coding the 30,000-Mr antigen of E. histolytica and that the combined use of the polymerase chain reaction and enzyme digestion is a useful strategy for identification of species and determination of pathogenicity.

Amino Acid Sequence↗
PubMed1991

Evidence that the tyrosine kinase domain of a small fraction of epidermal growth factor receptor molecules is exposed on the outer surface of A431 cells.

Intact A431 cells were labeled with [gamma-32P]ATP. The major phosphorylation product of the ecto-kinase activity of A431 cells had the molecular mass of 170 kd and was identified as EGF receptor by specific immunoprecipitation. This phosphorylation was not stimulated by EGF added to the reaction buffer, but replacement of MgCl2 by MnCl2 in the buffer remarkably stimulated phosphorylation. An exogenous protein substrate, alpha-casein, was also phosphorylated by intact A431 cells. The analyses for phospho-amino acids of both EGF receptor and alpha-casein revealed that phosphorylation occurred mainly at phosphotyrosine residues. Tryptic phospho-peptides of the EGF receptor of intact A431 cells labeled with [gamma-32P]ATP were fractionated by HPLC. The elution patterns were essentially the same as that of the autophosphorylated EGF receptor, indicating that the phosphorylation sites of EGF receptor labeled in vivo with [gamma-32P]ATP are located in three tyrosine residues in the carboxyl terminus. These results indicate that the carboxyl-terminal tyrosine kinase domain of a small fraction of the EGF receptor molecules of an A431 cell is exposed on the outer surface of the cells.

Adenosine Triphosphate↗
PubMed1991

[Twelve cases of laryngeal tuberculosis].

Between 1986 and 1990 we had twelve patients (ten males, two females, 19-65 years of age) with laryngeal tuberculosis who complained hoarseness and whose larynges were examined by fiberscopes. Chest roentgenograms revealed cavities in ten and in seven the lesions were extensive (Grade 3 according to the classification of Japanese Society for Tuberculosis). In all patients sputum smears were positive. Both patient's and doctor's delays were longer than those of patients with pulmonary tuberculosis without laryngeal involvements. Group infection was the source of infection in one patient. Since the diagnosis of laryngeal tuberculosis is difficult to make on clinical basis, it is important to make fiberscopic examinations of the larynx and do biopsies in patients with pulmonary tuberculosis who complain hoarseness.

Adult↗