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S Taira

Publications and source records attributed to S Taira.

At least 55 records · Page 3Linked to original sources
PubMed1994

Role of rpoS in the regulation of Salmonella plasmid virulence (spv) genes.

Salmonella plasmid virulence (spv) genes are organized into two transcriptional units: one formed by the spvR gene and the other by the spvA, spvB, spvC and spvD genes. Transcription of both units is activated by SpvR, a regulatory protein of the LysR family. The effect of RpoS, a stationary phase-associated sigma factor, on the expression of spv genes was studied using lacZ transcriptional fusions to spvR and spvA in wild-type and rpoS Escherichia coli backgrounds. Mutant and wild-type SpvR proteins were expressed in trans from a multicopy plasmid. The results show that the combined action of rpoS and spvR is necessary for transcription of spvA and that this combination also enhances transcription of spvR. Interestingly, spvR can also be transcribed in an alternative manner, i.e. in the absence of rpoS or spvR or both. The possible role for SpvR as a repressor of its own transcription is discussed.

Cloning, Molecular↗
PubMed1994

[A case-control study of risk factors for cerebral hemorrhage in Hirara-City, Okinawa Prefecture].

While the mortality rate of cerebral hemorrhage of Okinawa Prefecture is the lowest in Japan, the presence of a high incidence rate for cerebral hemorrhage has been pointed out in Hirara-city, Okinawa Prefecture. In order to develop an effective counter-measure, a case-control study of risk factors for cerebral hemorrhage was performed. Cases were 62 residents in Hirara city aged 40-69 years who had experienced cerebral hemorrhage between April 1987 through March 1992. From the 62 cases interviewed, responses were obtained from 49 cases. Controls were 147 residents without a history of stroke who were matched to cases individually by sex and age (control/case ratio = 3). From the 49 cases, 28 cases who had participated in residential mass health examinations before experiencing the cerebral hemorrhage, were matched individually sex and age with different randomly selected controls (control/case ratio = 10). From conditional logistic regression analysis of the interview survey data, history of hypertension, interruption of hypertension therapy, family history of stroke, long working hours, overwork and difficulty of taking a day-off each week were strongly related to increased risk of cerebral hemorrhage. Smoking, preference for salty taste and habitual drinking, also, elevated risk slightly. From analysis of the residential mass health examination data, high blood pressure was found to be strongly associated with cerebral hemorrhage, while serum cholesterol was inversely related.

Adult↗
PubMed1993

[Differentiation of benign from malignant pulmonary nodules with the digital analysis of computed radiography].

To differentiate benign pulmonary nodules from malignant nodules, digital analysis of computed radiography (CR) was performed retrospectively. A total of 142 histologically or clinically proved cases were studied. Digital analysis was performed using the method of gradient processing reported by Sherrier et al. Gradient number with and without background trend correction and gradient number corrected by L-value were obtained from the raw data of CR. The mean gradient of 93 malignant nodules was significantly different from that of 49 benign nodules. The analysis of gradient number without background trend correction and L-value correction was most sensitive. Seven radiologists evaluated these nodules as to benign or malignant, status, degree of calcification and homogeneity. A correlation was found between the detectability of benign nodules and degree of calcification. In conclusion, CR-gradient analysis is useful as a screening test to differentiate benign nodules from malignant ones.

Diagnosis, Differential↗
PubMed1993

Differential requirement for humoral factors for IL-2R expression of murine T cell subsets, Th1, Th2, and CD8Th clones.

Three types of alloreactive T helper (Th) cell clones, Th1, Th2, and CD8Th, were examined for the requirement of costimulatory factors for IL-2 receptor (IL-2R) expression and proliferation. When stimulated with allogeneic spleen adherent cells, these Th cell clones all expressed IL-2R strongly, whereas they expressed the receptor only weakly when subjected to allogeneic B cell stimulation. The addition of partially purified IL-2RIF to Th1, Th2, or CD8Th cell clones stimulated with B cell antigen-presenting cells increased the IL-2R expression of Th1 and CD8Th cell clones but not of the Th2 cell clone. Conversely, IL-1 up-regulated IL-2R expression of Th2 cell clones stimulated with B cell APC but not of Th1 and CD8Th cell clones. Neither IL-2RIF nor IL-1 induced IL-2R expression of unstimulated Th cell clones. IL-2R expressed in the presence of these costimulators contributed to IL-2-dependent proliferation of these cells. Thus, the expression of IL-2R was indicated to be regulated differently in three types of Th cell subsets through different cytokines.

Animals↗
PubMed1993

Transcriptional regulation of Salmonella enterica virulence plasmid genes in cultured macrophages.

The plasmid-carried spv genes promote virulence of salmonellae in mice by allowing bacterial growth in the reticuloendothelial tissue. When the bacteria are cultivated under normal laboratory conditions the spv genes appear dormant. This communication explores the transcriptional regulation of spv genes within murine macrophage-like J774-A.1 cells utilizing a new reporter system. Transcriptional fusions were constructed between promoter elements of the Salmonella enterica var. Typhimurium spv genes and the KS71A fimbrial gene cluster. The expression of KS71A fimbriae in fusion-carrying Escherichia coli strains was found to be under the control of the transcriptional activator gene spvR. In strains overproducing SpvR, KS71A fimbriae were assembled on the bacterial cell surface and could be detected by bacterial agglutination or immunofluorescence of intact bacteria; the reporter activity was quantified by estimating the percentage of fluorescent bacteria and by immunoblotting of cell lysates. The activity of the reporters, when transformed into the parent Typhimurium TML R66, was low and revealed less than 0.3% fimbriated cells under in vitro culture conditions. A 15-30-fold increase in fimbriation was observed when the bacteria were cultivated within J774-A.1 cells. No such increase occurred when the reporter fusions were transformed into TML R66 cured of the virulence plasmid. Insertional inactivation of the spvR gene of the virulence plasmid in Typhimurium TML R66 also abolished induction, whereas corresponding inactivation of spvA or spvB did not reduce induction. No increase in reporter activity was obtained in Typhimurium of line Q1, which is naturally avirulent for mice, although the strain was provided with virulence plasmid pEX102 of line TML R66. We conclude that the intracellular environment of J774-A.1 cells induces the spv genes and that this induction requires gene functions of both the bacterial chromosome and the virulence plasmid.

Animals↗
PubMed1993

Synthesis and structure-activity study of protease inhibitors. V. Chemical modification of 6-amidino-2-naphthyl 4-guanidinobenzoate.

By developing 6-amidino-2-naphthyl 4-guanidinobenzoate (I, FUT-175) as a basic structure, its various derivatives were synthesized and their inhibitory activities on trypsin, plasmin, kallikrein, thrombin, C1r and C1s as well as on complement-mediated hemolysis were examined. The protective effect of these compounds on complement-mediated Forssman shock was also examined in guinea pigs. 6-Amidino-2-naphthyl 4-[(4,5-dihydro-1H-imidazol-2-yl)amino]-benzoate (41, FUT-187) was found to be a suitable compound for oral administration with anti-complement activity superior to that of compound I.

Animals↗
PubMed1992

A new alpha-helical coiled coil protein encoded by the Salmonella typhimurium virulence plasmid.

A new protein of Salmonella typhimurium was identified and characterized. The gene (tlpA) encoding this protein (TlpA) was isolated from the large virulence-associated plasmid of S. typhimurium and sequenced in order to predict the primary structure of TlpA. tlpA encodes a 371-amino acid soluble protein with a calculated M(r) of 41600 and pI of 4.63. Secondary structure predictions and sequence statistics of TlpA indicated a predominant alpha-helical configuration and presence of heptapeptide repeat motifs characteristic of coiled coil proteins. Purified TlpA was shown to have biochemical properties similar to those of coiled coil proteins, including adoption of an alpha-helical configuration and a tendency to form homodimers. Furthermore, TlpA possessed heat resistance, evidence for a chain register and altered mobility in urea/sodium dodecyl sulfate-polyacrylamide gel electrophoresis gels which are characteristics of tropomyosins. TlpA shows 32% overall sequence similarity with rat cardiac myosin and 36% similarity with horse platelet beta-tropomyosin over 226 residues, whereas selected regions possessed significant sequence identities with myosins, tropomyosins, and alpha-helical surface proteins of Streptococcus pyogenes. Our results indicate that TlpA represents a new member of prokaryotic coiled coil proteins.

Amino Acid Sequence↗
PubMed1992

The virulence plasmid does not contribute to growth of Salmonella in cultured murine macrophages.

The virulence plasmid, characteristic of many serovars of Salmonella sp., and specifically its spv genes, promote intracellular growth of the bacteria in the liver and spleen and are essential for the virulence of these Salmonella serovars in the mouse. In an attempt to establish an in vitro model for studying its function, we evaluated its effect on the intracellular growth of the bacteria in macrophages in culture. We used a number of different macrophage-like cell lines (J774-A.1, IC-21 and PU5-1.8), as well as peritoneal or splenic macrophages from genetically Salmonella-sensitive (Itys, BALB/c) or resistant (Ityr, C3H/HeN) mice, and at different states of activation, stimulated in vivo or in vitro with lipopolysaccharide and/or recombinant gamma interferon. These were found to differ in their ability to suppress or sustain intracellular growth of several Salmonella serovars, but in all cases the growth was independent of the spv genes.

Animals↗
PubMed1992

Plasmid-mediated serum resistance in Salmonella enterica.

The ability of Salmonella enterica to survive an incubation of 2 h in fresh, pooled guinea-pig serum was determined comparing strain sets of serovariants Dublin and Typhimurium, harbouring or lacking the virulence plasmid. All strains showed marked serum resistance, which was slightly decreased among cured strains of Typhimurium. However, when introduced into a rough Escherichia coli strain, all Typhimurium plasmids substantially increased the resistance of the host strain to guinea-pig serum, whereas the Dublin plasmid did not. The traT gene, previously shown to affect serum resistance, was identified on all Typhimurium plasmids, but not on the Dublin plasmid. Mutational inactivation of the traT gene on the Typhimurium plasmids eliminated the serum resistance mediated by the plasmids.

Animals↗
PubMed1992

[Detection of Epstein-Barr virus DNA in salivary gland tumors].

To evaluate the relations between salivary gland tumors and Epstein-Barr virus (EBV), the levels of EBV-related antibodies were examined, and detection of EBV nuclear antigen (EBNA) and EBVDNA in tumor tissue was attempted by the anti-complement immunofluorescence technique and polymerase chain reaction, respectively. The mean VCA-IgG antibody level was increased to 925 (80-2560) in Warthin's tumor, 496 (40-2560) in mucoepidermoid tumor, and 206 (40-640) in pleomorphic adenoma. The positive rate of EA-IgG was high in Warthin's and mucoepidermoid tumors. VCA-IgA antibody was positive in 2 of the 7 cases of Warthin's tumor. EA-IgA antibody was negative in all cases. EBVDNA was detected in 7 of the 7 cases of Warthin's tumor, 3 of the 5 cases of mucoepidermoid tumor, and 2 of the 26 cases of pleomorphic adenoma. A relationship between Warthin's tumor and EBV was suggested by the 100% detection rate of the viral DNA.

Adenolymphoma↗
PubMed1991

Amino-terminal sequence analysis of four plasmid-encoded virulence-associated proteins of Salmonella typhimurium.

We have expressed four virulence-associated proteins encoded by the Salmonella typhimurium plasmid pEX102 in Escherichia coli. The genes coding for the proteins MkaA, MkaB, MkaC and MkaD subcloned in the vectors pUC19 or Bluescript KS+ directed substantial production of these proteins in E. coli. The same host harbouring pEX102 did not produce these proteins in detectable amounts. The proteins were exclusively found in the particulate fraction. The amino-terminal sequence analysis showed that the N-termini of these proteins corresponded to the ones predicted from the open reading frames found previously in the DNA sequence of the virulence determinant and that no N-terminal signal sequence processing of the proteins occurred.

Amino Acid Sequence↗
PubMed1991

The mkaC virulence gene of the Salmonella serovar typhimurium 96 kb plasmid encodes a transcriptional activator.

The intracellular growth and virulence of Salmonella serovar Typhimurium for mice is dependent on a plasmid-borne gene cluster termed mka. We studied the regulatory interactions of the genes mkaA, mkaB, mkaC and mkaD using lacZ gene fusions. Complementation experiments with cloned DNA fragments encoding each of the four MKa proteins indicated that mkaC enhances the expression of beta-galactosidase from the mkaA-, mkaB- and mkaC-lacZ gene fusions in trans. An mkaD-lacZ fusion or mkaA-lacZ fusion that did not contain DNA proximal to mkaB was not inducible with MkaC, indicating that at least mkaB and mkaA are induced together as an operon. MkaC is thus the first virulence protein whose function has been resolved.

Escherichia coli↗
PubMed1990

Nucleotide sequence of mkaD, a virulence-associated gene of Salmonella typhimurium containing variable and constant regions.

We have identified the nucleotide (nt) sequence of mkaD, a virulence-associated gene of the Salmonella typhimurium virulence plasmid, pEX102. The gene shows 98% homology on nt sequence level to mkfA, a corresponding gene of the S. typhimurium virulence plasmid pIP1350. The few nt changes, however, caused more extensive changes on the amino-acid level. The differences between mkaD and mkfA were clustered in distinct variable regions rather than being randomly scattered along the sequence. A third salmonellar virulence plasmid, pLT2, contained an mkaD gene identical to that of pEX102. Our observation suggests that the conserved virulence determinant on the plasmids of Salmonellae may contain different alleles of the same gene.

Amino Acid Sequence↗
PubMed1990

Production and secretion of pertussis toxin subunits in Bacillus subtilis.

Pertussis toxin (PT) is a major component of today's acellular whooping cough vaccines. The use of acellular vaccines is predicted to increase sharply in the near future. There is therefore a need to produce PT in a way that makes its purification as easy as possible. Our approach was to express all five PT subunits individually in Bacillus subtilis. We have used vectors containing the promoter and signal sequences of the alpha-amylase gene of Bacillus amyloliquefaciens followed by an insert encoding the appropriate PT-subunit. All PT-subunits were secreted and found in the culture supernatant. The level of expression varied considerably: S1 and S5 were produced in large quantities whereas much smaller amounts of S2, S3 and S4 were found. The subunits were also present in the membrane fraction of the respective strains.

Amino Acid Sequence↗
PubMed1990

Eye movement analysis system using computerized image recognition.

A new technique for an eye movement analysis system utilizing infrared video recording and a computerized image recognition method is presented. The system consists of an infrared lighting apparatus, a very small infrared video charge-coupled device camera, a video tape recorder, an analogue-digital converter, and microcomputers. This system makes it possible to simultaneously analyze the slow-phase velocity quantitatively not only of the horizontal and vertical but also of the rotatory components of the energy-induced nystagmus. The maximum slow-phase velocity of the rotatory component of energy-induced nystagmus was found to be 4.1 degrees per second on an average in this study.

Adult↗
PubMed1990

Efficacy of the high molecular weight fraction of plasma for the maintenance of pregnancy associated with thrombotic thrombocytopenic purpura.

We have investigated the methods for the maintenance of a pregnancy in a patient with thrombotic thrombocytopenic purpura (TTP), said condition, since 1984, having been controlled by a plasma infusion every 3 to 4 weeks. In a preliminary trial it was confirmed that an infusion of the high molecular weight fraction (HMW-F) of plasma, separated by an Evaflux 2A fractionator, improved the patient's thrombocytopenia as the plasma infusion, and maintained its beneficial effect for about 2 weeks during early pregnancy. Though an occurrence of a toxemia-like syndrome responded to repeated plasma infusion, the dose of plasma required to improve the thrombocytopenia gradually increased and reached 5,040 ml by the 20th week of pregnancy. Thus, instead of periodic infusions of whole plasma, periodic infusions of the HMW-F of plasma were used. Under this regimen the platelet count remained above 10.0 x 10(4)/microliters during late pregnancy, and the total dose (2,600 ml) of HMW-F of plasma that was administered until delivery at full term was less than the dosage of whole plasma that was used during early pregnancy. In this manner we were able to obtain a healthy baby by controlling the patient's TTP during pregnancy. This method of preventing thrombocytopenia appears to be safer with respect to volume loading during pregnancy in the TTP patient.

Adult↗