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Biomedical subjects

H Iwai

Publications and source records attributed to H Iwai.

At least 127 records · Page 7Linked to original sources
PubMed1990

Prolactin effects on the dietary regulation of mouse mammary tumor virus proviral DNA expression.

Chronic energy-intake restriction inhibits mouse mammary tumor virus (MMTV)-induced mammary tumors in C3H/Ou mice by greater than 90%. We have shown that associated with suppression of mammary tumorigenesis there is a reduction or inhibition of circulating prolactin, MMTV particles expressed, and MMTV mRNA transcription in mammary glands (and in most organs tested). To understand the concerted action of prolactin, energy-consumption level, and MMTV on inducing mammary tumors, experiments were designed to control prolactin and energy levels in order to evaluate their effects on MMTV mRNA expression. Mice on restricted diets were grafted with adenohypophyses, and mice fed ad libitum were treated with the dopaminomimetic agent octahydrobenzo [g]quinoline. Adenohypophyseal grafting significantly increased prolactin in dietary (energy)-restricted mice, and this effect was associated with an increase in MMTV mRNA expression within the mammary gland; a linear correlation between prolactin levels and MMTV mRNA expression in the mammary gland was found. Conversely, elimination of the nocturnal peak of circulating prolactin by i.p. injection of dopaminomimetic octahydrobenzo [g]quinoline to mice fed ad libitum delayed (by 8 weeks) and reduced (even as long as 25 weeks) mammary gland MMTV mRNA expression. These findings associate prolactin influences with MMTV mRNA production in mice and help explain the link between chronic energy-intake restriction and reduced MMTV gene expression.

Aminoquinolines↗
PubMed1990

[Efficacy of acellular pertussis vaccine].

An outbreak of pertussis occurred in one room of a residential facility where 19 children aged 5 to 36 months were residing. They were prospectively surveyed to estimate the efficacy of acellular pertussis vaccine. Among the 19 residents, 9 were immunized with acellular pertussis vaccine. Among the 19 residents, 9 were immunized with acellular DTP vaccine and 10 were unimmunized. The spread of pertussis was surveyed bacteriologically and serologically for 2 months. Among the 9 immunized, 7 children acquired the laboratory-confirmed pertussis and 1 of the 7 developed the typical symptoms (whooping or paroxysmal coughing attack lasting for 14 days or more). Among the 10 unimmunized, 7 children acquired the laboratory-confirmed pertussis and 6 of the 7 developed the typical symptoms. There was no difference in the rate of secondary infection (7/9:7/10), but there was a significant difference in the rate of development of the typical symptoms (1/7:6/7 p less than 0.05). The point estimate of protective efficacy of the acellular DTP vaccine against typical pertussis was (6/10 - 1/9)/(6/10) x 100 = 81%. It was concluded from these findings that acellular DTP vaccine could not prevent the infection of Bordetella pertussis, but could prevent the development of the typical symptoms.

Child, Preschool↗
PubMed1990

Antinucleolar autoantibody induced in mice by mercuric chloride.

Mercuric chloride (MC) was administered to mice subcutaneously 3 times a week for 4 weeks. When inbred BALB/c, CBA/JN, C3H/He, C57BL/6 and DBA/2 and outbred ICR female mice were given 1 mg/kg MC, 8 of 10 ICR mice developed antinucleolar autoantibodies (AnuA) of the IgG class but none of the inbred mice produced AnuA. So the ICR mice were used in the following experiments. In a kinetic study, in which mice were given 1.5 mg/kg MC, the positivities and titers of AnuA increased time-dependently, and were kept at high levels until 8 weeks after the final treatment. The AnuA titers of mice receiving 0.5-2.0 mg/kg increased dose-dependently, while the positivity was similar at all dosages. The antibody titers were higher in mice pretreated with an intramuscular injection of either complete or incomplete Freund's adjuvant. The titer increase was more prominent in mice administered doses lower than 0.5 mg/kg. Neither nude mice nor mice treated with a monoclonal antibody to L3T4 (GK1.5) developed AnuA. These results indicate that the induction of AnuA by MC depend primarily on L3T4-positive T cells.

Animals↗
PubMed1990

[Stress analysis of porcelain laminate veneers. (1)].

The stress distributions in the porcelain laminates under various kinds loading are analysed numberically in order to make clean the reason of their exfoliation or fracture. The two-dimensional finite element method is used to determine the principal stresses developed in the porcelain laminated and the teeth substance of a restored maxillary central incisor. The thicknesses of enamel preparations are assumed to be 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm and 0.8 mm in the analysis. As a result of this analysis, the following points are made clear: 1) The stress concentration are observed at the vicinity of a loading point and in the cervical regions, independently of the loading conditions on its location and direction. 2) In case of the vertical loading, the location of loading point has no effect on the overall stress magnitude and distribution. 3) In the case when the load is applied in the 45 degrees-direction to the vertical axis, the overall stress level is increased, as the location of loading point is far from the supporting regions. 4) In the case when the load is applied normal to the vertical axis at the incisal edge, the high stress is obtained in comparison with other loading conditions.

Bite Force↗
PubMed1989

Effect of immunization on HTLV-I infection in rabbits.

Two groups of 3 rabbits, each immunized with heat-inactivated HTLV-I or a synthetic env peptide (env175-196), developed antibodies to viral proteins including gp68 and gp46. These immunized rabbits were then challenged with a transfusion of blood from HTLV-I-infected rabbits of the opposite sex. After transfusion challenge, antibody titers further rose in both groups and antibodies to HTLV-I proteins p24 and p19 newly appeared in the env 175-196 group. In addition, 3 more rabbits were infused with hyperimmune rabbit anti-HTLV-I IgG and similarly challenged with virus-infected blood. Pre-challenge sera from these rabbits showed high anti-HTLV-I titers with antibodies to envelope and core proteins. Despite transfusion challenge, the antibody titers gradually declined to undetectable levels in all 3 rabbits over a period of 16 weeks. Virus isolation was attempted from peripheral lymphocytes harvested 1 to 6 months after challenge infection and cultured in the presence of interleukin-2 (IL-2). HTLV-I-carrying lymphoid cell lines of recipient origin were established from all 6 rabbits given active immunization, whereas HTLV-I could not be isolated from any of the 3 rabbits given passive immunization. Absence of virus infection in the latter group was confirmed by negative blood transfusion assay to normal rabbits. These results indicate that hyperimmune IgG, but neither heat-inactivated HTLV-I nor env 175-196, were protective against HTLV-I infection induced by blood transfusion.

Animals↗
PubMed1989

Efficacy and immunogenicity of acellular pertussis vaccine by manufacturer and patient age.

Acellular pertussis vaccines, which have been used in Japan since 1981, vary in antigenic constituents among manufacturers. First, to assess the immunogenicity by manufacturer and patient age, 161 children aged 3 months to 2 years were immunized by acellular pertussis vaccine from one of three Japanese manufacturers, Biken, Takeda, or Kitasato. Anti-pertussis toxin antibody responses for children immunized with Takeda and Kitasato vaccines were comparable with patients with pertussis in the convalescent stage, and anti-pertussis toxin antibody response for Biken vaccine was far higher than those of convalescing patients. Anti-filamentous hemagglutinin antibody responses for the children given the three vaccines were far higher than those of the patients. Weak serotype 1.3 agglutinin responses were observed only in children administered the Takeda vaccine. Comparing these antibody responses among various age groups, the immunogenicity of acellular vaccines in children aged 3 to 6 months was comparable with children aged 2 years. Second, to assess the manufacturer-specific efficacy, 495 households of patients with pertussis were surveyed from 1981 to 1988. The estimated efficacy of the acellular pertussis vaccines in children aged 2 to 8 years was 82%, and there were no major differences in the secondary attack rates among children immunized with acellular pertussis vaccine from each manufacturer, ie, 12.5% (1/8) for Biken, 11.1% (2/18) for Takeda, and 5.9% (1/17) for Kitasato. We conclude from these two studies that similar efficacy was observed in children aged 2 years or older for acellular pertussis vaccines from the three manufacturers, which produced anti-pertussis toxin antibody responses comparable with patients with pertussis and far higher antifilamentous hemagglutinin antibody responses than in the convalescing patients, and that age did not affect the immunogenicity of acellular vaccines.

Age Factors↗
PubMed1989

Immunological functions in food-restricted rats: enhanced expression of high-affinity interleukin-2 receptors on splenic T cells.

Several immunological functions of B and T cells including IL-2 receptor expression on T cells were measured in 12-month-old Fisher-344 male rats maintained from 6 weeks of age on an ad libitum (AL) or a 40% food-restricted (FR) diet. Direct anti-SRBC plaque-forming cell (PFC) assays revealed a higher response in FR rats than in AL rats when splenocytes were cultured with or without recombinant interleukin-2 (rIL-2). B cell functions were studied by using nylon wool-purified splenic B cells stimulated either with rIL-2, lipopolysaccharide (LPS), or Salmonella typhimurium mitogen (STM) as a thymus-independent antigen. Reserve plaque assay showed no difference between FR and AL rats in the secretion of anti-IgM and anti-IgG antibodies. In addition, no difference was found in proliferation of B cells stimulated by LPS, STM mitogens or rIL-2. Although purified splenic T cells demonstrated an equally proliferative response in FR and AL rats when cultured with concanavalin A (Con A) or phytohemagglutinin (PHA), T cells in FR rats developed higher responses when stimulated with an alloantigen and rIL-2. Time-course studies carried out to measure high-affinity (HA) IL-2 receptor (R) molecules by using purified T cells with rIL-2 and 125I-labeled IL-2 revealed a higher expression of IL-2R molecules on T cells of FR rats than on T cells of AL rats at 72 h after culturing with Con A.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Long-term observations of autoimmune-prone mice treated for autoimmune disease by allogeneic bone marrow transplantation.

Long-term effects of allogeneic bone marrow transplantation (ABMT) across major histocompatibility complex barriers were studied in (NZB x NZW)F1 (B/W), BXSB, and MRL/Mr-lpr-lpr (MRL/lpr) mice with established autoimmune disease at the time of ABMT. In the BXSB or B/W mice, ABMT cured all aspects of autoimmune disease. Glomerular damage, revealed by histological study was dramatically improved. Serological abnormalities and immunologic functions also were normalized. Correction of autoimmune disease and advanced renal disease in BXSB and B/W mice regularly lasted greater than 5-6 mo and even 1 yr after ABMT. In the MRL/lpr mice, however, autoimmune and renal disease at first improved but then recurred after ABMT, apparently because of intolerance of mice for high doses of irradiation and a high degree of resistance of recipient stem cells to irradiation. In this model, H-2 typing revealed that by the time of relapse, immunocompetent cells of the chimeric mice had been replaced by host (MRL/lpr; H-2k) cells. B220+ Ly-1+ cells, present in increased numbers in untreated MRL/lpr mice, initially returned to normal levels after ABMT but then reappeared in the MRL/lpr mice that had received marrow from donors having few such lymphocytes. Thus, our results show that MRL/lpr mice possess abnormal radioresistant stem cells and provide impressive evidence that the origin of autoimmune diseases in this strain, as in the several other strains studied, residues in abnormalities present in stem cells.

Animals↗
PubMed1989

Acceptance of murine thyroid allografts by pretreatment of anti-Ia antibody or anti-dendritic cell antibody in vitro.

A new method for thyroid allografts in mice was established. Thyroids of C67BL/6J mice were treated with collagenase, and the follicles were isolated using a Percoll density gradient technique. These follicles were treated with anti-Ia antibody (Ab) or anti-DC Ab plus complement in order to eliminate DCs. The follicles were then mixed with agarose and transplanted under the left renal capsule of BALB/c mice. One hundred days after transplantation, acceptance of the grafts was verified by both histological study and the incorporation of 125I into the grafts. Allografts treated with C were rejected, whereas allografts treated with Ab plus C were accepted. When nontreated thyroids of C57BL/6J mice were grafted under the right renal capsule of BALB/c mice that had accepted DC-depleted thyroids of C57BL/6J mice, the nontreated thyroids were rejected. These findings indicate that DCs play a crucial role in the rejection of mouse thyroid allografts, and that the depletion of DCs permits allografts to be accepted without inducing donor-specific tolerance. Our method presented here may be developed as a viable strategy for the treatment of patients with congenital or acquired hypothyroidism.

Animals↗
PubMed1989

Cooperation between humoral factor(s) and Lyt-2+ T cells in effective clearance of Sendai virus from infected mouse lungs.

The mechanism of cooperation between the L3T4+ and Lyt-2+ T cell subsets in effective clearance of Sendai virus from infected mouse lungs was studied by adoptive cell transfer using nude mice. Simultaneous transfer of a long-term-cultured Sendai virus-specific L3T4+ T cell line with L3T4+ cell-depleted immune spleen cell (L3T4-) fraction to infected nude mice could result in viral clearance, although single injection with either of these cells was not effective. Instead of the L3T4+ T cells, culture supernatants of the L3T4- T cell line or concanavalin A-stimulated mouse spleen cells and mouse serum immunized with the virus were also active in the cooperative viral clearance with L3T4- fraction. The role of the Sendai virus-sensitized L3T4- cell fraction in cooperative viral clearance with humoral factors could be replaced by neither T cell-deprived immune spleen cell fraction nor normal spleen cells. The 1,500 units of recombinant mouse interleukin 2 (IL-2), which was more than 12 times the IL-2 activity present in the supernatants of the T cell line or concanavalin A-stimulated spleen cells, failed to clear the virus in combination with the L3T4- fraction. Monoclonal antibodies to Sendai or mouse hepatitis viruses were also effective in the cooperative antiviral activity. IL-2 activity was not detected in these monoclonal antibodies and the mouse immune serum. Single injection of any humoral factors failed to clear the virus. These results indicate that Sendai virus-sensitized Lyt-2+ subset of T cells acts cooperatively with humoral factor(s) other than IL-2 or Sendai virus-specific antibody present in supernatants of the T cell line, of concanavalin A-stimulated spleen cells or hybridomas, and in mouse serum immunized with the virus.

Animals↗
PubMed1989

Antigenic variation among Sendai virus strains detected by monoclonal antibodies.

Thirteen strains of Sendai virus isolated from various sources in the 1950's and after 1976 were compared for their reactivities with monoclonal antibodies prepared against the prototype strain MN of Sendai virus. Results revealed that while the 5 strains isolated in the 1950's reacted with all the monoclonal antibodies as the prototype strain did, the 2 strains isolated in 1976 and 1978 did not react with an F-specific monoclonal antibody, and the other 6 strains isolated after 1978 lacked reactivity with an HN-specific monoclonal antibody.

Antibodies, Monoclonal↗
PubMed1989

Gluconeogenesis in perfused livers from dexamethasone-treated chickens.

Gluconeogenesis was studied in hemoglobin-free perfused livers from chickens that had received daily injections of dexamethasone sulfate for 5 days. Dexamethasone increased to approximately 160% the level of plasma glucose and doubled the content of hepatic glycogen in fed chickens. In the isolated perfused livers from chickens starved for 48 h after the last dexamethasone injection, the rates of production of glucose from lactate decreased by approximately 30% and biphasic changes in glucose production from fructose proceeded in parallel with biphasic changes in the production of lactate and pyruvate. Quinolinate had no effect on gluconeogenesis in both groups. NH4Cl markedly inhibited the production of glucose from pyruvate-lactate mixtures in dexamethasone-treated chickens but stimulated in controls. Aminooxyacetate reversed the effects of NH4Cl in dexamethasone-treated chickens. The data presented provide evidence indicating that the reaction of mitochondrial alanine aminotransferase plays an important role in the regulation of the hepatic gluconeogenesis in dexamethasone-treated chickens.

Alanine Transaminase↗
PubMed1989

Comparison of lung virus titers in susceptible and resistant inbred mouse strains against Sendai virus infection.

Susceptibility of inbred mouse strains to Sendai virus (Mol strain) infection was studied. Although some mouse strains showed age differences in susceptibility between 3-to 4-week-old and 7-to 8-week-old mice, such age differences in susceptibility were not observed in susceptible DBA/2N and resistant BALB/cA mice. In 7-to 8-week-old mice, remarkable strain differences were observed in mortality and intensity of the lung lesions, but not in lung virus titers and serum antibody, between resistant BALB/cA and susceptible DBA/2N mice.

Age Factors↗
PubMed1989

[Connective tissue attachment to root surfaces in periodontal disease. Initial attachment of human gingival fibroblasts].

We studied the effect of periodontal treatment (scaling, SC; root planning, RP; scaling followed by citric acid, SC + CA; and root planing followed by citric acid, RP + CA) of periodontally diseased root surfaces on the initial attachment of human gingival fibroblasts in vitro. Root slices were prepared from surgically extracted human normal and periodontally involved teeth. Each treated root slice was placed in a well of a 24-well plate containing a PBS-antibiotic solution (penicillin, 200 units/ml; streptomycin, 200 micrograms/ml) for 1 hr. at 4 degrees C. Then, to each well was added 1 x 10(4) cells in 1 ml of alpha-MEM, and the plates were incubated for 24 hr. After the root slices were fixed and stained, the morphological changes and the numbers of attached cells were determined under a dissecting microscope. The fibroblasts on the controls (untreated normal roots) and the RP-roots appeared spindle-shaped with a few cell processes. The cells on the SC-roots were rounded or slightly elongated. The cells on the roots treated with citric acid (SC + CA and RP + CA) had were flat and seemed well attached to the surface. The number of cells attached on RP- and RP + CA-roots was increased to the control level, but those on SC- and SC + CA-roots were showed about 60% of the control. No significant differences in the numbers of cells were found between RP and RP + CA treatment or between SC and SC + CA treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Cell Adhesion↗
PubMed1989

Surgical management of residual gastric cancer.

From 1966 to 1985, 2130 patients with gastric cancer were admitted to our surgical department. Among these cancers, gastric cancer following partial gastrectomy for benign gastroduodenal lesion were present in 22 (1%) patients. The original pathology was gastric ulcers in 64% (14 patients), duodenal ulcers in 23% (5 patients), combined gastric and duodenal ulcers in 9% (2 patients), and leiomyoma of the gastric cardia in 4% (1 patient). Fourteen patients were reconstructed by Billroth II, 7 by Billroth I, and one had an esophagogastrostomy after a proximal gastrectomy. The cancer in 19 (86%) patients was resected and 3 (14%) could not be resected. Only 2 (9%) were early cancer, 20 (89%) were advanced cancer including 11 (50%) with Borrmann type 3. A higher proportion of positive lymphnode metastasis was observed for residual gastric cancer (84%) than for primary gastric cancer (49%). The overall 5-year survival rate was 32%, with a 5-year survival rate of 45% for those who underwent curative resection.

Aged↗
PubMed1989

Infection of rabbits with Sendai virus.

Rabbits were either inoculated with Sendai virus (SV), strain MN, or caged with virus-inoculated rabbits on the same day of the viral inoculation, and examined for viral shedding and detection of viral antigens in the respiratory tract, histopathologic changes, and serum antibodies. Infectious virus was recovered from nasal swabs at postinoculation day (PID) 3 and disappeared by PID 10. Viral antigens were detected by immunofluorescence in epithelial cells of the nasal cavities, but not of the trachea and lungs from PID 3 to PID 10, and antibodies were detected after PID 7. Rabbits had no clinical manifestations and only exhibited a moderate increase in goblet cells of the nasal epithelium. In the transmission study, virus was recovered from one of three uninoculated rabbits at postexposure day (PED) 10 and antibodies were detected at PED 15 in the same rabbit. These data suggest that, although viral multiplication was limited to the nasal epithelium, laboratory rabbits are susceptible to Sendai virus infection.

Animals↗
PubMed1989

Adoptive immunity to Mycobacterium bovis strain bacillus Calmette-Guérin by long-term cultured T-cell line in nude mice.

Tuberculin-active peptide-reactive T-cell lines were established from the popliteal lymph node of BALB/cA mice immunized with heat-killed Mycobacterium tuberculosis to investigate the cellular mechanisms in the protective immunity of tuberculosis. These T-cell lines, consisting mainly of L3T4 surface antigen-positive cells, were transferred intravenously into nude mice infected with M. bovis strain bacillus Calmette-Guérin (BCG). Four or 6 weeks after transfer, footpad swelling and hepatic granuloma formation were observed and viable counts in the liver were decreased. Reduction of viable counts in the liver was obviously preceded by the hepatic granuloma formation. An effect of Lyt-2+ T cells which might be included in the inoculum could be ruled out by the experiment using T-cell lines pretreated with anti-Lyt-2 monoclonal antibody and complement. These results indicated that T cells required for protective immunity in these experiments belong to the L3T4-positive TDTH subset. However, their protective activity was inferior to that of freshly prepared immune lymph node T cells. From the observation of migration patterns of 51Cr-labelled T cells in BCG-infected nude mice, a relatively high proportion of freshly isolated T cells, but only a small part of T-cell line, deposited in the spleen of infected nude mice. This difference in migration pattern of freshly isolated and cultured T cells could be one of the reasons for the less in vivo anti-bacterial activity of the latter.

Animals↗