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Biomedical subjects

H Tomioka

Publications and source records attributed to H Tomioka.

At least 19 recordsLinked to original sources
PubMed1992

Properties and the primary structure of a new halorhodopsin from halobacterial strain mex.

A new halorhodopsin-like pigment from the new halobacterial strain mex (Otomo, J., Tomoika, H. and Sasabe, H. (1992) J. Gen. Microbiol. 138, 1027-1037) was partially purified, and its amino acid sequence from helices A to G was determined using PCR technique. Two arginine residues in the A-B interhelix loop segment, a series of six amino acid residues (EMPAGH) in the B-C interhelix segment and most of the residues near the Schiff base of the retinal were found to be conserved in three halorhodopsins (halobium, pharaonis and mex). This result strongly suggests that these residues are essential for anion pumping function in halorhodopsin. The light-induced ion-pump measurements have shown that the selectivity of anion transport between chloride and nitrate in mex halorhodopsin is lower than that of halobium halorhodopsin, but higher than that of pharaonis halorhodopsin. The number of amino acid residues in the B-C interhelix loop segments is different in each halorhodopsin, and it correlates with their anion (chloride and nitrate) selectivity. These results suggest that the length of the B-C segment affects the selectivity of anion transport in halorhodopsin.

Amino Acid Sequence↗
PubMed1992

Chromophore configuration of pharaonis phoborhodopsin and its isomerization on photon absorption.

The configuration of the retinylidene chromophore in pharaonis phoborhodopsin (ppR) and its changes during the photoreaction cycle were investigated by means of a chromophore extraction method followed by HPLC analysis. The ppR has an all-trans chromophore, and unlike bacteriorhodopsin, it exhibits no dark isomerization of the chromophore. Irradiation of a ppR sample in the presence of 10 mM hydroxylamine, at which concentration a negligible amount of ppR was bleached, caused the formation of 90% 13-cis- and 10% all-trans-retinal oximes. Because the ppR sample under the continuous irradiation was a mixture containing original ppR, ppRM, and a small amount of ppRO, the above results showed that the chromophores of ppRM and ppRO are in a 13-cis form and an all-trans form, respectively. Therefore, the all-trans chromophore of ppR is isomerized to the 13-cis form on photon absorption, and it is thermally reisomerized to the all-trans form on the conversion process from ppRM to ppRO. The extracted retinal oximes from ppR and ppRO were mainly the 15-syn form, while that from ppRM was mainly the 15-anti form. This fact indicated that the attack of hydroxylamine on the chromophore is stereoselective owing to the unique structure of the chromophore binding site near the Schiff base region of the chromophore.

Archaeal Proteins↗
PubMed1992

Photocycle of phoborhodopsin from haloalkaliphilic bacterium (Natronobacterium pharaonis) studied by low-temperature spectrophotometry.

Phoborhodopsin (pR) is the fourth retinal pigment of Halobacterium halobium and works as a photoreceptor for the negative phototactic response. A similar pigment was previously found in haloalkaliphilic bacterium (Natronbacterium pharaonis) and also works as the receptor of the negative phototactic response; this pigment is called pharaonis phoborhodopsin (ppR). In this paper, the photocycle of ppR was investigated by means of low-temperature spectrophotometry. The absorption maximum of ppR is located at 498 nm, while that of pR is at 487 nm. The absorption spectra of the two have similar vibrational structures. Irradiation of ppR below -100 degrees C produced a K-like intermediate (ppRK) which was a composite of two components. The original ppR and ppRK were perfectly photoreversible. On warming, ppRK was directly converted to an M-like intermediate without formation of the L-like intermediate. The M-like intermediate was converted to the O-like intermediate at pH 7.2, but the O-like intermediate was not detected at pH 9.0. The O-like intermediate then reverted to the original pigment. On the basis of these findings, the photocycle and the primary photochemical process of ppR are presented.

Archaeal Proteins↗
PubMed1992

T cell receptor V beta repertoire of double-negative alpha/beta T cells in patients with systemic sclerosis.

OBJECTIVE: To analyze the T cell receptor V beta gene on double-negative (DN) alpha/beta T cells, which are increased in number, on peripheral blood lymphocytes (PBL) from patients with systemic sclerosis (SSc). METHODS: The DN alpha/beta T cells were sorted by flow cytometry from PBL obtained from 3 patients with SSc. The V beta repertoire was analyzed by polymerase chain reaction. RESULTS: Only 1 or 2 V beta genes (V beta 5/7, 5, or 17) were predominantly expressed on DN alpha/beta T cells from these 3 patients. CONCLUSION: The V beta repertoire on DN alpha/beta T cells in PBL from patients with SSc is rather restricted.

Base Sequence↗
PubMed1992

Restricted junctional usage of T cell receptor V beta 2 and V beta 13 genes, which are overrepresented on infiltrating T cells in the lips of patients with Sjögren's syndrome.

OBJECTIVE: To analyze the clonality of T cell receptor (TCR) V beta 2- and V beta 13-positive T cells, which are predominantly expressed in the lips of patients with Sjögren's syndrome (SS). METHODS: The junctional sequences of complementary DNA clones encoding TCR V beta 2 and V beta 13 genes were determined by the polymerase chain reaction. Forty-one V beta 2 and 45 V beta 13 clones established from the lips of 3 SS patients were sequenced. RESULTS: The V beta 2/J beta 2.3 pair was enriched in 2 of the 3 patients (44% and 46% of the clones, respectively), and the V beta 13/J beta 2.1 sequence was dominant in 2 of the 3 (23% and 45%). These pairs were not used preferentially in peripheral blood lymphocytes from the same patients. CONCLUSION: Infiltrating V beta 2- and V beta 13-positive T cells from the lips of all 3 patients with SS were polyclonal, but the junctional usage of cells from 2 lip samples was restricted, compared with cells from peripheral blood. This suggests that not all expanded cells from the lips of SS patients are stimulated by superantigens.

Base Sequence↗
PubMed1992

Characterization of immunosuppressive functions of murine peritoneal macrophages induced with various agents.

Murine peritoneal macrophages (M phi s), induced with stimuli such as thioglycollate, zymosan A, OK-432, bacille Calmette-Guérin (BCG), or live Mycobacterium intracellulare, showed varying levels of inhibitory activity against the concanavalin A (Con A) blastogenic response of splenic T cells. All test M phi s significantly inhibited the interleukin 2 (IL-2)-producing ability of T cells but this inhibition was not enough to explain the observed reduction in T cell Con A mitogenesis. In contrast, they markedly inhibited IL-2-reactive T cell generation, and the inhibition was sufficient to cause the reduction in T cell mitogenesis. A general relationship was observed between immunosuppressive activity of a given M phi and its active oxygen-producing ability (measured in terms of chemiluminescence) in response to phorbol myristate acetate triggering (r = .84, P less than .005). However, the suppressor activity of test M phi s was not reduced by superoxide dismutase and catalase, indicating that active oxygen radicals themselves did not mediate the expression of the immunosuppressive activity of these M phi s. On the other ahnd, indomethacin (an inhibitor of prostaglandin synthesis) caused a partial reduction in their immunosuppressive activity. The suppressor activity of M phi s induced with intraperitoneal injection of recombinant interferon gamma (IFN-gamma) was markedly reduced in the presence of myoglobin, a scavenger for nitric oxide radical (NO.). Tumor necrosis factor alpha (TNF alpha) failed to affect Con A mitogenesis of splenic T cells, even in combination with IFN-gamma. On the other hand, unsaturated long-chain fatty acids including oleic, linoleic, linolenic, and arachidonic acids markedly reduced the T cell function. These findings suggest some important roles of prostaglandins, NO., and long-chain unsaturated fatty acids as mediators of the expression of immunosuppressive function of the peritoneal M phi s.

Animals↗
PubMed1992

Role of CD4+ T lymphocytes and interleukin-5 in antigen-induced eosinophil recruitment into the site of cutaneous late-phase reaction in mice.

Previous studies suggested that the eosinophil recruitment into the site of cutaneous late-phase reaction (LPR) was dependent on IgE antibody and mast cells. In this study, we determined the role of CD4+ T cells and CD8+ T cells in causing antigen-induced eosinophil recruitment of LPR in mouse skin. Eosinophil infiltration into the subcutaneous tissue of ovalbumin (OVA)-sensitized BALB/c mice was biphasic, reaching the first peak at 6 h after the subcutaneous challenge with OVA and the second peak at 24 to 48 h. The in vivo depletion of CD4+ T cells by pretreatment with anti-L3T4 monoclonal antibody (mAb) significantly decreased the second peak (at 24 h and 48 h), but not the first peak (at 6 h), of OVA-induced eosinophil infiltration into the skin of OVA-sensitized mice. However, the depletion of CD8+ T cells by pretreatment with anti-Lyt-2 mAb had no significant effect on either the first peak or second peak of OVA-induced cutaneous eosinophilia. Pretreatment with anti-murine interleukin-5 (IL-5) mAb also decreased the second peak, but not the first peak, of OVA-induced cutaneous eosinophilia. In contrast to the inhibitory effects of depletion of CD4+ T cells and of anti-IL-5 mAb on the second peak of antigen-induced cutaneous eosinophilia, disodium cromoglycate and a selective antagonist for platelet activating factor (PAF) CV-6209 decreased the first peak of OVA-induced cutaneous eosinophilia in the mouse. These results indicate that CD4+ T cells, but not CD8+ T cells, cause the second peak of antigen-induced eosinophil recruitment of cutaneous LPR and that IL-5 mediates this eosinophil recruitment. In contrast, the first peak of antigen-induced eosinophil recruitment of cutaneous LPR is mediated by mast cells and PAF.

Animals↗
PubMed1992

In vitro and in vivo activities of KRM-1648, a newly synthesized benzoxazinorifamycin, against Mycobacterium marinum.

The in vitro and in vivo activities of KRM-1648, one of the newly synthesized benzoxazinorifamycins, against M. marinum were compared with those of rifampin. The MIC values of KRM-1648 determined by the agar dilution method on 7H11 medium against 10 strains of M. marinum were 32-128 times and even more below those of rifampin. In an in vivo experiment, KRM-1648 was markedly effective in terms of the incidence of gross skin lesions and the number of CFUs in the lungs and spleen. Its efficacy was much greater than that of rifampin.

Animals↗
PubMed1992

The primary structures of helices A to G of three new bacteriorhodopsin-like retinal proteins.

The primary structures of helices A to G of all bacteriorhodopsin (BR)-like retinal proteins identified in newly isolated halobacteria have been determined from the nucleotide sequence of the BR-like protein genes. Using PCR methods, gene fragments encoding the A- to G-helix region of BR-like proteins were directly amplified from the total genomic DNA of the seven new halobacterial strains. Oligonucleotide primers corresponding to highly conserved regions in the helices A to G were designed from the nucleotide sequences of bacterioopsin (bop) and archaeopsin-I (aop-I), and some primers were effective for the amplification of the gene encoding C- to G-helix region of all new BR-like proteins. The primer corresponding to A-helix region was designed either from the nucleotide sequence of bop and aop-I or from the N-terminus amino acid sequence of a BR-like protein. Three new BR-like proteins were identified from the amino acid sequence, which was deduced from the nucleotide sequence of the genes encoding A- to G-helix region of the BR-like proteins. It was found that not only the amino acid sequence, but also the nucleotide sequence of the gene encoding the C- and G-helix region, in which a number of important residues for proton translocation are located, is highly conserved in three new BR-like proteins. Analysis of the primary structures of the A- to G-helix region of new BR-like proteins revealed that one has about 85% homology with aR-I and aR-II, and the rest have about 55% homology with halobium BR, aR-I and aR-II.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1992

The protective activity of immunostimulants against Listeria monocytogenes infection in mice.

The function of peritoneal macrophages induced by intraperitoneal (i.p.) injection of attenuated Streptococcus pyogenes (OK-432), Bacillus Calmette Guérin (BCG), protein-bound polysaccharide preparation isolated from Coriolus vesicolor (PSK) or Lactobacillus casei was examined. The PMA-triggered respiratory burst (production of O2- and H2O2) of macrophages induced by OK-432, BCG or Lac. casei was greater than that of resident or thioglycollate-stimulated macrophages and was similar to that of BCG-activated macrophages. PSK failed to enhance the production of O2- or H2O2 by macrophages. Alkaline phosphodiesterase (APD) activity was reduced in macrophages induced by OK-432, BCG or Lac. casei injection and in BCG-activated macrophages. The APD activity of macrophages obtained 7 and 13 days after i.p. injection of PSK was elevated, as with thioglycollate-stimulated macrophages. Listericidal activity in vitro was enhanced in macrophages obtained in 13 and 7 days, but suppressed in macrophages obtained 2 days after OK-432, BCG or Lac. casei injection. Lac. casei administered either 2 or 13 days before infection with Listeria monocytogenes was protective but OK-432, BCG (0.1 mg) and PSK were not, even though they were able to stimulate macrophage function.

Adjuvants, Immunologic↗
PubMed1992

Substance P-induced granulocyte infiltration in mouse skin: the mast cell-dependent granulocyte infiltration by the N-terminal peptide is enhanced by the activation of vascular endothelial cells by the C-terminal peptide.

Previous studies have shown that substance P induces granulocyte infiltration in mouse skin, which is mediated through mast cell degranulation. However, it is not yet known whether the direct effect of substance P on vascular endothelial cells is involved in the granulocyte infiltration in the skin. To solve this issue, we used the N-terminal peptide substance P1-9 (SP1-9), which is active for mast cells but inactive for vascular endothelial cells, and the C-terminal peptide SP6-11, which is active for vascular endothelial cells but inactive for mast cells, since substance P activates both mast cells and vascular endothelial cells. The subcutaneous administration of substance P (10(-7)-10(-5)M) caused granulocyte (neutrophil and eosinophil) infiltration in the skin of BALB/c mice 6 h after the injection. SP1-9 (10(-5)-10(-4) M) also caused granulocyte infiltration of mouse skin which was associated with mast cell degranulation. In contrast, SP6-11 (10(-7)-10(-4) M), which was found to increase the vascular permeability of endothelial cells in mouse skin, induced no significant granulocyte infiltration nor mast cell degranulation. However, SP6-11 (10(-5)-10(-4) M) enhanced SP1-9-induced granulocyte infiltration in the skin without any significant increase in mast cell degranulation. We conclude that substance P causes granulocyte infiltration in mouse skin through both mast cell degranulation induced by the N-terminal peptide of substance P and the activation of vascular endothelial cells induced by the C-terminal peptide of substance P.

Animals↗
PubMed1992

[A case of adult respiratory distress syndrome likely due to measles and Mycoplasma pneumoniae].

We described a case of adult respiratory distress syndrome (ARDS) likely due to measles and Mycoplasma pneumoniae. A 24-year-old, previously healthy man was referred to our hospital because of respiratory arrest. He was unconscious and cyanotic. He had erythematous and polymorphic eruptions of his extremities and trunk, but his face was spared. His chest roentgenogram showed consolidation with air bronchograms affecting the whole bilateral lungs. After mechanical ventilation with positive end-expiratory pressure and administration of intravenous hydrocortisone and protease inhibitor "urinastatin" and so on, the patient recovered from his critical condition. No attributable organisms were isolated from the specimens investigated in his acute phase. Serological examinations of the specific IgM antibody to measles during the course indicated a recent measles infection. Mycoplasma pneumoniae indirect hemagglutination test rose from a titre of less than 1/40 to 1/60. ARDS is a rare complication of measles or Mycoplasma pneumoniae infection. Moreover he received measles vaccine before 1970 in Japan, so this case was suspected to be atypical measles.

Adult↗
PubMed1992

Chemotherapeutic efficacy of a newly synthesized benzoxazinorifamycin, KRM-1648, against Mycobacterium avium complex infection induced in mice.

Newly synthesized benzoxazinorifamycin, KRM-1648, was studied for its in vivo anti-Mycobacterium avium complex (MAC) activities. When the MICs were determined by the agar dilution method with Middlebrook 7H11 agar medium, KRM-1648 exhibited similarly potent in vitro antimicrobial activities against the MAC isolated from AIDS and non-AIDS patients, indicating possible usefulness of KRM-1648 against AIDS-associated MAC infections. KRM-1648 exhibited potent therapeutic activity against experimental murine infections induced by M. intracellulare N-260 (virulent strain) and N-478, which has much weaker virulence. Similarly, KRM-1648 exhibited an excellent therapeutic efficacy against M. intracellulare infection induced in NK-cell-deficient beige mice (as a plausible model for AIDS-associated MAC infection), in which a much more progressed state of gross lesions and bacterial loads at the sites of infection were observed. When the infected beige mice were killed at weeks 4 and 8, obvious therapeutic efficacy was seen on the basis of reduction in the incidence and degree of lung lesions and bacterial loads in the lungs and spleen with infections due to M. intracellulare N-241, N-256, and N-260. In this case, the efficacy was the highest in N-260 infection, followed by strain N-241. When mice were observed until infection-induced death, survival time of the infected beige mice was found to be prolonged by KRM treatment. However, KRM-1648 was not efficacious in suppressing the progression of pulmonary lesions and the increase in bacterial loads at the sites of infection, including lungs and spleen, at the late phase of infection. This may imply some difficulty with chemotherapy for AIDS-associated MAC infection, even with KRM-1648 treatment, which has excellent in vitro and in vivo anti-MAC activities, as shown in present study.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Predominant expansion of V gamma 9/V delta 2 T cells in a tularemia patient.

We describe a 58-year-old man with tularemia and expanding gamma delta T cells in his peripheral blood lymphocytes (PBL) (32.7% of total PBL). In the present work, we analyzed the T-cell receptor V gamma/V delta repertoire of these cells by making use of the polymerase chain reaction and flow cytometry and found that they were mostly CD4- CD8- CD3+ V gamma 9/V delta 2+. The sequence analysis of 16 cDNA clones encoding the V gamma 9-J region revealed that the V gamma 9-Jp combination was strikingly overrepresented but that the junctional (N) region was heterogeneous. This suggested that the gamma delta T cells in PBL from a patient with tularemia were polyclonally expanded.

Base Sequence↗
PubMed1992

Differential susceptibilities of Mycobacterium avium and Mycobacterium intracellulare to sodium nitrite.

Sixty-seven of 72 strains of Mycobacterium avium (93.1%) were resistant to sodium nitrite at a concentration of 3 mg/ml in 7H11 agar medium, while 57 of 59 strains of Mycobacterium intracellulare (96.6%) were susceptible to the agent. The difference in the susceptibilities of M. avium and M. intracellulare to sodium nitrite is therefore useful for the differentiation of the two species.

Drug Resistance, Microbial↗
PubMed1992

Comparison of substance P-induced and compound 48/80-induced neutrophil infiltrations in mouse skin.

It has recently been shown that substance P induces neutrophil infiltration in the skin, which is mediated through mast cell degranulation. Since substance P activates both skin mast cells and vascular endothelial cells, we compared the potencies of substance P and a mast cell-degranulating agent, compound 48/80, which is inactive for vascular endothelial cells, in inducing neutrophil infiltration in mouse skin. We also examined the effect of the C-terminal peptide of substance P, SP6-11, which is active for vascular endothelial cells, on compound 48/80-induced neutrophil infiltration in the skin. Subcutaneous administrations of substance P (10(-7) to 10(-5) M; 0.1 ml) and compound 48/80 (0.5-50 micrograms/ml) induced neutrophil infiltrations and mast cell degranulations in mouse skin in a concentration-dependent fashion. Moreover, substance P induced more neutrophil infiltrations than compound 48/80 in terms of the magnitude of mast cell degranulations. SP6-11 (10(-6) to 10(-4) M) induced no significant neutrophil infiltration or mast cell degranulation, but increased the vascular permeability of endothelial cells in the skin. Furthermore, SP6-11 enhanced compound 48/80-induced neutrophil infiltration without any increase in mast cell degranulation. Our results indicate that, in addition to mast cell degranulation, the activation of vascular endothelial cells is involved in substance P-induced neutrophil infiltration in the skin.

Analysis of Variance↗
PubMed1992

CD4+ T-lymphocytes and interleukin-5 mediate antigen-induced eosinophil infiltration into the mouse trachea.

In order to determine the role of CD4+ and CD8+ T-cells and of interleukin-5 (IL-5) in causing antigen-induced eosinophil infiltration into the site of airway late-phase reaction, we examined the effect of the in vivo depletion of CD4+ and CD8+ T-cells on the eosinophil infiltration of the trachea induced by antigen inhalation in mice. We also studied the effect of anti-murine IL-5 monoclonal antibody (mAb) on the antigen-induced eosinophil infiltration in the trachea. The eosinophil infiltration into the trachea of ovalbumin (OVA)-sensitized BALB/c mice began to increase 9 h after OVA inhalation and persisted for more than 48 h. The in vivo depletion of CD4+ T-cells by pretreatment with anti-L3T4 mAb significantly decreased the eosinophil infiltration induced by OVA inhalation in the trachea of sensitized mice. However, the in vivo depletion of CD8+ T-cells by pretreatment with anti-Lyt-2 mAb had no significant effect on OVA-induced eosinophil infiltration in the trachea. Pretreatment with anti-murine IL-5 mAb also decreased OVA-induced eosinophil infiltration in the trachea. In contrast, neither disodium cromoglycate nor a selective antagonist for platelet-activating factor CV-6209 decreased OVA-induced airway eosinophilia in the mouse. Our results provide direct evidence that CD4+ but not CD8+ T-cells mediate antigen-induced eosinophil recruitment in the airways and that IL-5 mediates this eosinophil recruitment.

Administration, Inhalation↗