Biomedical subjects

H Iwai

Publications and source records attributed to H Iwai.

At least 109 records · Page 6Linked to original sources

PubMed1993

Thyroid follicle transplantation by percutaneous injection.

We previously reported on the isolation of thyroid follicles from thyroid tissue and their acceptance after allogeneic transplantation under the renal capsule with laparotomy in mice. In the present study, we introduced a new method of autologous transplantation of thyroid follicles accepted in the hosts after percutaneous injection into the spleen or into fat tissue in the peritoneal cavity without laparotomy in rats. This method of thyroid transplantation by a single injection, which induces little stress in the host, is applicable to autologous and allogeneic transplantations and may release patients from the burden of daily life-long administration of thyroxine.

Animals↗

PubMed1993

Efficacy of acellular pertussis vaccine in young infants.

A prospective study of a pertussis outbreak in a residential facility was done. Among 19 residents aged < or = 2 years, 10 children were unimmunized and 9 were immunized with acellular pertussis vaccines. Of the 10 unimmunized children, 7 acquired laboratory-confirmed pertussis (four-fold titer rise, positive culture, or both); of these, 6 developed typical symptoms. Eight of the 9 immunized children acquired laboratory-confirmed infections, and 1 of these developed typical symptoms. No difference in infection was noted between the unimmunized and immunized groups (7/10 vs. 8/9, respectively), but a significant difference was observed in the development of symptoms (6/10 vs. 1/9, P < .05). Also, the isolation rate of Bordetella pertussis seemed to differ between the two groups (6/10 vs. 2/9, P = .12). In this population, acellular pertussis vaccine did not prevent infection with B. pertussis but protected most young infants from the onset of clinical symptoms.

Antibodies, Bacterial↗

PubMed1992

Pertussis in adults.

A survey was conducted of 89 households in each of which at least one patient with culture-confirmed pertussis had been detected. The source of infection was found to be an adult in 10 (11.2%) of the 89 households, and the rate of secondary attack was 19 (10.3%) of 185. Furthermore, a laboratory study disclosed 17 adults with subclinical pertussis; the subclinical infection rate was 17 (25.0%) of 68. When compared with pertussis in young children, the adult illness was generally less severe and had different clinical features. Adult pertussis showed neither leukocytosis nor lymphocytosis, but it produced anti-pertussis toxin antibody more quickly and higher levels of anti-filamentous hemagglutinin and agglutinin antibodies, and showed stronger growth inhibition of Bordetella pertussis. Although adult pertussis is usually unrecognized because of its different clinical and laboratory features, it is a significant health threat that requires some measures for disease control.

Adult↗

PubMed1992

Genomic analysis of Theileria sergenti stocks in Japan with DNA probes.

Restriction fragment length polymorphisms of Theileria sergenti DNA from 18 different infections of cattle in 14 locations in Japan were analyzed by Southern blotting using T. sergenti genomic DNA fragments as probes. Probe pTs 2 hybridized with four fragments in BamHI digested piroplasm DNA, at 8.0, 7.3, 6.0 and 3.4 kb. Probe pTs 11-D1 hybridized with multiple fragments. With each probe, polymorphisms were observed among stocks from different locations. However, there was no correlation between the patterns of hybridization bands and the locations where parasites were collected. Analysis of the hybridization patterns of stocks obtained from individual cattle in the same grazing areas showed an almost identical pattern.

Animals↗

PubMed1992

Pharmacokinetics of fluorinated 2-nitroimidazole hypoxic cell radiosensitizers in murine peripheral nervous tissue.

We have previously reported that KU-2285, a 2-nitroimidazole with a fluorinated N1-substituent (-CH2-CF2CONH(CH2)nOH, n = 2), was a promising hypoxic cell radiosensitizer. In this study the pharmacokinetics of KU-2285 and its related compounds (n = 3 and n = 4) were compared with those of etanidazole (a 2-nitroimidazole with an N1-substituent of -CH2CONH(CH2)nOH, n = 2) and its related compounds (n = 3 and n = 4) to assess the effects of incorporation of a CF2 group. The lipophilicity of the fluorinated compounds was higher than that of etanidazole, as measured by the octanol/water partition coefficient. As the number of CH2 groups increased, the lipophilicity of the compounds in both the KU-2285 and etanidazole series increased. The brain tissue levels of the fluorinated compounds were as low as those of the etanidazole derivatives, while the biological half-lives of the fluorinated compounds in peripheral nervous tissues were shorter than those of related non-fluorinated compounds.

Animals↗

PubMed1992

Activation of bovine peripheral blood monocyte and its suppressive effect on parasitemia in Theileria sergenti infected calves.

Activation of bovine peripheral blood monocytes and its suppressive effect on parasite growth was examined in Theileria sergenti-infected calves by using a rosette assay that detects changes in Fc receptor expression and by luminol-dependent chemiluminescence response. Monocyte activation preceded the peak of parasitemia but was depressed parallelly with the growth of the parasites. When four calves were treated with prednisolone, three showed a good correlation between the suppression of monocyte activity and an increase of parasitemia.

Animals↗

PubMed1992

Inhibitory effects of organotin compounds on histamine release from rat serosal mast cells.

Tributyltin inhibited compound 48/80-induced histamine release from rat serosal mast cells in a dose-related manner. Triphenyltin and tripropyltin also showed a strong inhibitory effect on the histamine release and the degree of the inhibition was the same as that of tributyltin. The inhibitory effects of other organometals were much smaller than those of the organotins. Tributyltin and triphenyltin also showed a tendency to inhibit histamine release induced by concanavalin A + phosphatidylserine and calcium ionophore A 23187. The present results suggest that certain triorganotin compounds may have a specific inhibitory effect on histamine release by acting on the same process in each of the three stimulus responses.

Animals↗

PubMed1992

Infection and dysfunction of monocytes induced by experimental inoculation of calves with bovine immunodeficiency-like virus.

Three calves were experimentally inoculated with bovine immunodeficiency-like virus (BIV) to examine BIV pathogenesis. Inoculated calves produced specific antibody that could be detected from 3 to 5 weeks up to 1 year postinoculation (pi). Virus was isolated from peripheral blood mononuclear cells (PBMC) 3-4 weeks pi by syncytia assay. Thereafter, the virus could be continually isolated. BIV could be isolated from monocytes but not from T cells. Likewise, monocytes could be infected with BIV in vitro. Various monocyte functions of these BIV-infected calves and age-matched uninfected calves were tested; superoxide anion release, phagocytic activity, and chemotactic responsiveness of monocytes were depressed in BIV-infected calves compared with control calves. A slight delay in the humoral immune response against mouse serum protein was also evident. During the observation period of approximately 1 year, no significant clinical symptoms could be observed. One calf, however, was killed at 15 months pi. At the time of necropsy, BIV could be isolated from PBMC as well as from cells of the spleen, liver, and lymph nodes.

Animals↗

PubMed1991

In vivo radiosensitizing activity of a new fluorinated hypoxic cell radiosensitizer, KU-2285, in combination with radiation dose fractionation.

Since most clinical radiotherapy is given as multiple small irradiation fractions, the present study was undertaken to test the in vivo radiosensitizing activity of a new hypoxic cell radiosensitizer, KU-2285, in combination with radiation dose fractionation. Radiosensitizing activity was measured by a growth delay assay using a transplanted mammary tumor in C3H/He mice, and by an in vivo-in vitro assay using the SCC VII tumor. KU-2285 was injected intraperitoneally 30 min before irradiation in all experiments. The in vivo-in vitro assay using SCC VII tumors showed that 12.5 micrograms/g of KU-2285 sensitized the tumors to irradiation (5 Gy/fr x 5 fr/48 hr or 6 Gy/fr x 3 fr/48 hr). KU-2285 also sensitized the transplanted mammary tumors to fractionated irradiation. We concluded that KU-2285 was able to sensitize two different murine tumors when given in combination with radiation dose fractionation.

Animals↗

PubMed1991

[Simple and efficient method for clinical isolation of Bordetella pertussis].

Commercially available Amies transport medium with charcoal and three isolation media were tested to assess their efficiency in the clinical isolation of B. pertussis. First, the isolation rates of B. pertussis were compared between direct inoculation of nasopharyngeal specimens and inoculation after stored in Amies transport medium for 8 hours or less. The comparative isolation rates were 81% both (35 of 43 specimens from 29 patients) for direct inoculation and transport medium. Second, nasopharyngeal specimens were incubated for 5 days at 35 degrees C on the three media; Bordet-Gengou Medium (BG) with 5 micrograms of CEX per ml, Cyclodextrin Solid Medium (CSM) with 5 micrograms of CEX per ml, and Charcoal Agar with 40 micrograms of CEX per ml. The organism was detected from 44 nasopharyngeal specimens from 20 patients on at least one of the three tested media. The comparative isolation rates were 91% (40 of 44) on BG with 5 micrograms of CEX per ml, 93% (41 of 44) on CSM with 5 micrograms of CEX per ml, and 91% (40 of 44) on CA with 40 micrograms of CEX per ml. Although no differences in the isolation rates were observed among the three media, the appearance of the colonies was earlier by one day on BG than the rest of the two media. The detection of B. pertussis was occasionally easier on CA than the rest of the two because of its higher suppression for nasopharyngeal flora. CSM has its advantage in that it does not need any blood and can be prepared at anytime. Also, the shelf life of these three media proved to be at least one month when stored at 10 degrees C. We conclude that the clinical isolation of B. pertussis was highly successful with the following simple procedure: nasopharyngeal specimens stored in Amies transport medium and inoculated on one of the three media, BG, CSM, or CA, and then incubated for 5 days at 35 degrees C.

Bacteriological Techniques↗

PubMed1991

Comparative lung pathology of inbred strain of mice resistant and susceptible to Sendai virus infection.

BALB/cA, DBA/2N and CDF1 (BALB/cA x DBA/2N) mice were inoculated intranasally with the Mol strain of Sendai virus (SV), and their mortality and histopathological lung lesions were compared. BALB/cA and CDF1 were resistant and DBA/2N was susceptible in terms of mortality. The lung lesions of the resistant strains were mild and focal, and limited to the bronchial regions, whereas those of the susceptible stain were severe and diffuse, extending to the alveoli. SV antigen was found mainly in the bronchial epithelium in the resistant strains, but in the susceptible strain, the antigen was found also in many alveolar epithelial cells and alveolar macrophages. SV antigen was detected in neither regenerated bronchial epithelium nor endothelial cells. Tumor necrosis factor (TNF) was detected immunohistologically in edematous perivascular regions and in some mononuclear cells infiltrating to the regions, suggesting that TNF is involved in the development of lung lesions by SV infection in the three mouse strains.

Animals↗

PubMed1991

Antifungal and antiviral activities of benanomicins and their analogues.

In vitro activities of benanomicins and their analogues against human immunodeficiency virus and fungi including Candida, Cryptococcus and Aspergillus, were examined. The free carboxyl group and at least one sugar moiety in the benanomicins were essential for their activities. Benanomicin A was most active and had low toxicity, and was selected as the best candidate for chemotherapy.

Animals↗

PubMed1991

Simple and efficient method for clinical isolation of Bordetella pertussis.

Commercially available Amies transport medium with charcoal and three isolation media were tested to assess their efficiency in the clinical isolation of B. pertussis. First, the isolation rates of B. pertussis were compared between direct inoculation of nasopharyngeal specimens and inoculation after being stored in Amies transport medium for eight hours or less. The organism was detected in 43 specimens from 29 patients with at least one of the two inoculation methods. The comparative isolation rates were 81% (35 of 43) for both direct inoculation and transport medium. Second, nasopharyngeal specimens were incubated for five days at 35 degrees C on the three media; Bordet Gengou Medium (BG) with 5 micrograms of CEX per ml, Cyclodextrin Solid Medium (CSM) with 5 micrograms of CEX per ml, and Charcoal Agar with 40 micrograms of CEX per ml. The organism was detected from 44 nasopharyngeal specimens of 20 patients on at least one of the three tested media. The comparative isolation rates were 91% (40 of 44) on BG with 5 micrograms of CEX per ml, 93% (41 of 44) on CSM with 5 micrograms of CEX per ml, and 91% (40 of 44) on CA with 40 micrograms of CEX per ml. Although no differences in the isolation rates were observed among the three media, the appearance of the colonies was earlier by one day on BG than the other two media. The detection of B. pertussis was occasionally easier on CA than on the other two because of its higher suppression of nasopharyngeal flora.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacteriological Techniques↗

PubMed1991

Mixed outbreak of Bordetella pertussis and Bordetella parapertussis in an apartment house.

From September through November of 1985, a mixed outbreak of Bordetella pertussis and Bordetella parapertussis occurred in an apartment house in Ashikaga City, Japan. Bacteriological and serological investigations were conducted on seven families, comprising 13 adults and 19 children, living in the same apartment house and having social contacts. For all the subjects, cultivation of nasopharyngeal mucus and measurement of pertussis agglutinin antibody, anti-PT antibody, and anti-F-HA antibody were performed. On the basis of the clinical, bacteriological or serological findings, seven children of three families (families A, B and C), including the first child patient (index case) of family A, were diagnosed as having infections caused by B. pertussis, or B. parapertussis or both. B. pertussis and/or B. parapertussis were isolated from six of the seven child patients. B. pertussis alone was isolated from three children (one in each family), and two of them had not been vaccinated. B. parapertussis alone was isolated from two children, while both bacteria were isolated from one child. Those three children from whom B. parapertussis was isolated were in family C, which was the last of the three families to develop symptoms of infection. Josamycin had been administered to two of the three children from whom B. parapertussis was isolated before the nasopharyngeal mucus specimen was collected. In one of the two children from whom only B. parapertussis was isolated, the significant elevation of anti-PT antibody titer was observed, which was indicative of a mixed infection with B. pertussis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1991

Outbreak of pertussis in a residential facility for handicapped people.

An outbreak of pertussis was recognized and investigated in a ward for neurologically impaired residents. Of 50 residents ranging in age from 8 to 25 years old, 41 (82%) had serological or bacteriological evidence of pertussis infection and 28 (56%) developed typical symptoms of pertussis. Of the 50 residents, nine were immunized and 41 were unimmunized. There were no significant differences in the rate of infection and rate of developing typical symptoms between the immunized and unimmunized (9/8/4 vs 41/33/24). Of 43 carers, 6 (14%) developed typical symptoms and four of the six showed serological evidence of pertussis infection. Epidemiological survey of this outbreak revealed that pertussis was introduced and spread by the carers. Erythromycin which was administered only to the residents did not prevent the spread of pertussis. We conclude that pertussis immunization including a booster dose should be considered for neurologically impaired people in a closed environment and erythromycin prophylaxis should include adult carers.

Adolescent↗

PubMed1991

Long-term immunologic tolerance induction in chimeric mice after bone marrow transplantation across major histocompatibility barriers: persistent or redeveloping immunologic responsiveness after prolonged survival.

Employing allogeneic bone marrow chimeras [B6----C3H] (C3H/HeN mice lethally irradiated and then reconstituted with T cell-depleted C57BL/6J bone marrow), we investigated the kinetics of immunological reconstitution and the functional characteristics of the immune system at regular intervals following bone marrow transplantation (BMT). In chimeric mice, almost all spleen cells and peritoneal macrophages showed donor H-2 haplotype within 2 weeks after BMT. The differentiation and maturation of B lymphocytes and macrophages was largely complete by 2 weeks following BMT, whereas T cell functions such as Con A responsiveness and alloreactivity were not restored within 4 weeks. Newly developed T cells were found to be exclusively of donor origin but were tolerant of both donor type and host type major histocompatibility complex (MHC) determinants in assays of mixed lymphocyte reactions and capacity to generate cytotoxic T lymphocytes. Fully allogeneic chimeric mice survived up to one year after bone marrow transplantation without significant reactions or serious diseases. Neither graft-versus-host reaction (GVHR), host-versus-graft reaction (HVGR), nor the wasting diseases described. As compared to age-matched control mice, such fully allogeneic chimeras exhibited one year following BMT somewhat reduced but quite significant plaque forming cell responses to in vitro stimulation with a T-dependent antigen, SRBC. These findings suggest that BMT across MHC barriers may ultimately be useful in humans if all manifestations of GVHR are eliminated by completely removing all T cells from the bone marrow and if all hematopoietic resistance and all aspects of HVGR are eliminated by using sufficient immunosuppression and myeloablation.

Animals↗

PubMed1991

[Evaluation of pre-operative 5-fluorouracil treatment of the patients with gastric cancer--alteration of the inhibition rate of thymidilate synthetase by dose difference].

5-fluorouracil (5-FU) was orally administered before surgical operation to two groups of patients, one treated at 300 mg for 7 days and the other treated at 400 mg for 5 days, to examine the change of TSIR in gastric patients. Tumor tissue, lymph node and normal lesions were collected from removed specimens immediately frozen. As a result, there were no differences in FdUMP volumes of various tissues between 300 mg and 400 mg groups. TSIR tended to be higher in the order of normal tissue, lymph node and tumor lesions. TSIR was significantly higher in 400 mg group than 300 mg group. We believe that further studies on TSIR will provide a useful information as to various studies, including efficacy reinforcement by combination therapy, problems in resistance, histological efficacy and sensitivity tests.

Fluorouracil↗

PubMed1990

Experimental and clinical evaluation of the splenic capping method in the treatment of injured spleens.

Polyglycolic acid elastic mesh was tailored and wrapped around the entire surface of experimentally injured spleens in 11 dogs, while carefully avoiding the splenic hilum, like a "hair-net", to achieve complete hemostasis by compression. All 11 dogs survived the experiment with no postoperative bleeding observed. Histological examination, performed 6 weeks postoperatively, revealed histiocytes, fibroblastic proliferation with collagen and cellular collagenized fibrous tissue forming a neocapsule covering the spleen. Hematologically, the platelet count was increased at 2 weeks postoperatively, but subsequently decreased to within the normal levels by 4 weeks. We employed this splenic capping method clinically in four cases to avoid splenectomy and sufficient hemostasis with ultimate splenic recovery was achieved in each case without any abscess formation, postoperative bleeding, or complications related to the use of the mesh. These experimental and clinical results thus indicate the efficacy and safety of the splenic capping method for preserving the injured spleen.

Adult↗