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Biomedical subjects

S Yamazaki

Publications and source records attributed to S Yamazaki.

At least 217 records · Page 12Linked to original sources
PubMed1997

Comparison of gelatin particle agglutination and hemagglutination inhibition tests for measles seroepidemiology studies.

The prevalence of measles antibody in Japan was surveyed with a newly developed gelatin particle agglutination (PA) test, and the results compared with those of the hemagglutination inhibition (HI) test. The two age-distribution curves of the PA antibody-positive rates at > or = 1:8 and > or = 1:32 were almost the same in all the age groups, except the less-than-1-year-old group for which the rate at > or = 1:8 was higher than that at > or = 1:32 (p < 0.05, chi 2 test). In the vaccinated children, all groups older-than-1-year of age had antibody-positive levels of 96% or more. In contrast, in the unvaccinated children, there was a sharp increase in antibody-positive rates between the 1- and 4-year-old groups, indicative that about 80% of the children were infected by wild measles virus at these ages. A significant number of PA antibody-positive specimens were antibody-negative (< 1:8) by HI. The percentage of specimens in this category, PA (+) but HI (-), was greatest in infants less than one year old, and least in young children, but it increased with age to 97% of the HI (-) specimens from adults of more than 20 years of age. The PA test therefore detected some measles antibodies that HI could not. This test is simple and useful for making serosurveys in both developed and developing countries.

Adolescent↗
PubMed1997

Development of a gelatin particle agglutination reagent for measles antibody assay.

A new agglutination test that utilizes gelatin particles as the carrier of measles antigen was developed and used to evaluate immune status to measles virus infection. The particle agglutination (PA) reagent reacted with monoclonal antibodies against two major proteins of measles virus, the hemagglutinin (H) and fusion (F) proteins. Children were followed individually for ten years for measles antibody. Results showed that the PA test was as sensitive and specific as the plaque neutralization test. The procedure is simple and rapid. No prior treatment of specimens is needed, and the test is completed in a single reaction. The PA test therefore can be used for diagnoses and epidemiologic surveys of measles virus infection.

Agglutination Tests↗
PubMed1997

Effect of anti-intercellular adhesion molecule-1 and anti-leukocyte function associated antigen-1 monoclonal antibodies on rat-to-mouse cardiac xenograft rejection.

BACKGROUND: The interaction between intercellular adhesion molecule-1 (ICAM-1) and its ligand, leukocyte function associated antigen-1 (LFA-1), is especially relevant in allograft rejection. We have previously shown that the simultaneous blockade of ICAM-1 and LFA-1 by monoclonal antibodies (mAbs) results in specific immunologic tolerance to cardiac allograft in a mouse model. METHODS: We evaluated the roles of these adhesion molecules in xenograft rejection by using a rat-to-mouse concordant xenograft model to identify critical molecules for immunosuppression. RESULTS: Lewis rat hearts transplanted into C3H/He mice were rejected within 5 to 7 days without treatment. A significant prolongation of xenograft survival (mean survival time, 11.6 days) was observed after treatment with anti-rat ICAM-1 and anti-mouse LFA-1 mAbs, when compared with nontreated mice or mice treated with different combinations of mAbs. Graft survival was prolonged in mice treated with FK506 (1 mg/kg/day), anti-rat ICAM-1, and anti-mouse LFA-1 mAbs (mean survival time, 22.2 days), whereas the same dose of FK506 alone was not effective. The mixed lymphocyte reaction showed that a combination of mAbs against mouse LFA-1-rat ICAM-1 and rat LFA-1-mouse ICAM-1 significantly inhibited the proliferation of mouse responders to rat stimulators and rat responders to mouse stimulators, respectively. Infiltration of mouse CD4 positive, mouse CD8 positive, and mouse LFA-1 positive cells, as well as dense deposition of mouse immunoglobulin G (IgG), IgM, and up-regulation of rat ICAM-1, on the graft endothelial cells were demonstrated by immunopathologic analysis of the rejected hearts. Flow cytometric analysis with rat spleen cells demonstrated the presence of xenoreactive antibodies (mouse IgG and IgM) in the recipient's serum. This xenoreactive antibody production was delayed but not inhibited by treatment of the recipients with anti-rat ICAM-1 and anti-mouse LFA-1. CONCLUSIONS: Blockade of the donor side ICAM-1 and the recipient side LFA-1 is critical for immunosuppression with anti-ICAM-1-LFA-1 treatment. Humoral factors may be responsible for xenograft rejection that occurs even after inhibition of the cell-mediated immune response by anti-ICAM-1 and anti-LFA-1 mAbs.

Animals↗
PubMed1997

Cutaneous localization of endothelin-1 in patients with systemic sclerosis: immunoelectron microscopic study.

BACKGROUND: Endothelin-1 (ET-1) has some relation to the pathogenesis of systemic sclerosis (SSc) and Raynaud's phenomenon. This study was performed to determine the localization of ET-1 in patients with SSc. METHODS: The localization of ET-1 on the specimen by skin biopsies from nine patients with SSc, was observed with immunoelectron microscopic techniques. RESULTS: High-density deposits existed on the ribosomes and on the rough endoplasmic reticulum in the endothelial cells of microvessels of the upper dermis. The same findings were also seen in the fibroblasts of the dermis, but not found in the skin of normal controls. The level of deposits in the endothelial cells and dermal fibroblasts seemed to have a positive correlation with the serum levels of ET-1 of patients with SSc. CONCLUSIONS: From these results, it can be seen that ET-1 is produced much more from the endothelial cells and fibroblasts of the dermis in the skin of SSc patients than from the normal controls. It is suspected that ET-1 is one of the pathogenetic factors of SSc.

Biopsy↗
PubMed1997

Identification and functional characterization of yeast zeta-COP.

Coatomer, the cytosolic protein complex, consists of seven subunits (alpha-, beta-, beta'-, gamma-, delta-, epsilon-, and zeta-COP) and is involved in vesicle trafficking early in the secretory pathway in collaboration with a 20 kDa GTP-binding protein (ARF). In the present study, we have identified a yeast gene which encodes a protein having 39% amino acid sequence identity with bovine zeta-COP. This gene (YZC1 for Yeast Zeta COP) is essential for vegetative growth and the growth defect of delta yzc1 cells was restored by bovine zeta-COP cDNA. We isolated a temperature-sensitive mutant of YZC1 (yzc1ts) and examined its capacity for both the ER-to-Golgi transport and the double lysine motif (KKXX)-mediated retrograde transport from Golgi to ER. At non-permissive temperature, the yzc1ts cells exhibited a weak defect in the anterograde transport, but a strong defect in the retrograde vesicle transport. We conclude that Yzc1p is a yeast homologue of mammalian zeta-COP and participates mainly in the Golgi-to-ER retrograde transport.

Amino Acid Sequence↗
PubMed1997

Father-to-mother-to-infant transmission of HIV-1: clonally transmitted isolate of infant mutates more rapidly than that of the mother and rapidly loses reactivity with neutralizing antibody.

The sequences of the V3 loop and surrounding regions of human immunodeficiency virus type-1 from a father-to-mother-to-infant trimmer were studied and the horizontal and vertical transmissions compared. The father's virus was variable for reactivity with neutralizing antibody and sequences of the V3 loop central core sequence. In contrast, the mother's viral sequences were much less diverse and reacted with a virus neutralizing antibody. The infant's viral sequences were also less diverse than those of the father, and N-glycosylation sites were conserved. By phylogenetic analysis, the major clone, of which V3-peptide reacted with the neutralizing antibody, was found to be transmitted from the mother to her infant; however, the mutated minor clones did not bind to the antibody. These findings suggest that both horizontal and vertical virus transmission were selective, and that the clonally transmitted virus in infants mutates more rapidly than viruses in the mother, to whom the virus was horizontally transmitted.

Amino Acid Sequence↗
PubMed1997

Relationship between ultrasound assessment of arterial wall properties and blood pressure.

Physical properties of an artery can be described in terms of stiffness, distensibility, and compliance. Changes in these properties can predict atherosclerosis disease, but it is necessary to identify an index that is independent of changes in blood pressure. We measured common carotid artery diameter and pulsatile change with an ultrasonic phase-locked, echo-tracking system in 7 subjects whose mean brachial blood pressure had varied 15 mm Hg or more within a month. Patients taking antihypertensive agents were excluded from the study. We measured changes in arterial diameter (n = 41) at least four times during the study period and calculated the pressure-strain elastic modulus (Ep), distensibility coefficient (DC), cross-sectional compliance (CC) and stiffness parameter (beta) from inner diameter, its pulsatile change, and blood pressure. The correlation coefficients of mean blood pressure with each index are as follows: Ep, 0.53; DC, 0.58; CC, 0.63; beta, 0.21. When mean blood pressure increased 1 mm Hg, the change in each index at 100 mm Hg was as follows: Ep, 1.48 +/- 1.30%; DC, -1.05 +/- 0.97%; CC, -0.69 +/- 0.90%; beta, 0.45 +/- 1.11%. Among the four indices that measure the properties of the arterial walls, stiffness parameter beta was the least dependent on blood pressure. Thus, it appears to have usefulness as an index of arterial wall sclerosis.

Aged↗
PubMed1997

[Analysis of contact dermatitis by cytokines. I].

The study of the participation of T cells and the kinetic studies of cytokines by the RT-PCR method in the challenge phase of contact hypersensitivity reaction (CHR) were performed using skin tissues collected at regular intervals from mice sensitized with 2,4-dinitro-1-fluorobenzene (DNFB). The results obtained from these studies and the further analyses using anti-CD4 and CD8 antibodies showed that the revelation of phenotype of lymph node cells at the reaction site and T lymphocytes at the CHR site were found to play important roles. Furthermore, we examined cytokines formed at the CHR site on the mRNA level. Consequently, it was found that 24 h after the challenge IFN-gamma, IL-6 and IL-1 beta were expressed and 48 h after the challenge IL-2, IL-4 and TNF-alpha were expressed in addition to these cytokines. The results of the expression of IL-12 and those of the examination using IFN-gamma knock out mice suggested that the expression of IFN-gamma among several Th1 types of cytokine is especially important for the formation of CHR.

Animals↗
PubMed1997

[Analysis of contact dermatitis by cytokines. II].

We examined the mechanism of the onset of contact hypersensitivity reaction (CHR) induced by several kinds of chemical substances in mice, focusing on cytokines. Before doing this experiment, we investigated the involvement of T cells in the formation of CHR using each primer of CD4 and CD8 (surface markers of lymphocytes) positive cells. It was suggested that both cells participate in the formation of CHR. On the basis of these results we analyzed cytokines produced in the reaction site on the mRNA level in with or without the presensitization of two kinds of strong contactants. Consequently, there was a tendency that the expression of mRNA of Th1 types of cytokines was commonly observed around 24 h after the reaction irrespective of the presence or the absence of presensitization. These date suggested that CHR can be presumed on the genetic level by the only one priming of strong contactants.

Animals↗
PubMed1997

[Retrograde radical cystectomy. Advantages of our "vesico-rectal tunnel" method].

BACKGROUND: The facilitation of dissecting the vesical pedicles and undisturbed preservation of the membranous urethra were investigated during radical cystectomy using the retrograde technique. METHODS: First, just as with radical prostatectomy, the prostate and the rectum were separated by blunt digital dissection. After the deep dorsal vein complex and the urethra were cut, the bladder and the rectum were also separated in a retrograde manner towards the Denonvillier's fascia. Then the peritoneum was opened and its lowest part was incised above the cul-de-sac. A tunnel was made beginning at the cut-end of the urethra to the cul-de-sac. Consequently, the bladder was lifted up by hand inserted this "vesico-rectal tunnel" and the bilateral remaining lateral pedicles were ligated and transsected without difficulty. RESULTS: Fourteen patients underwent radical cystectomy using this technique. Among them, the average operating time and blood loss in 4 patients received retrograde radical cystectomy accompanied with ileal conduit were 5 hours 15 minutes and 1606 ml, respectively. These in 9 patients received retrograde radical cystectomy followed by bowel orthotopic urinary reservoir were 7 hours and 6 minutes and 1086 ml, respectively. Another patient received ureterocutaneoustomy. CONCLUSION: Creating a "vesico-rectal tunnel" during radical cystectomy primarily by the retrograde extraperitoneal technique can afford to preserve the urethral sphincter and to ligate the pedicles easily. This method is fundamentally familiar to us because retrograde radical prostatectomy is now widely adopted and it may help to reduce the operating time even when there is a shortage of manpower.

Aged↗
PubMed1997

[Antiemetic efficacy of granisetron in repeated CAF chemotherapy after breast cancer operation].

The antiemetic efficacy of granisetron in repeated CAF chemotherapy after breast cancer operation was investigated. Twenty-three patients who were treated with repeated CAF chemotherapy after breast cancer operation received drip-infused granisetron (3 mg/body) to prevent nausea and vomiting. Antiemetic efficacy was evaluated by means of the severity of nausea and the frequency of vomiting. The antiemetic efficacy rate of the drug was 74.4%. However, the average rate of antiemetic efficacy was 86.9% on the first through the sixth administration of the chemotherapy (first period). 75.9% on the seventh through the twelfth (second period), 48.4% on the thirteenth through the eighteenth (third period), and 31.8% on the nineteenth through the twenty-fourth (fourth period). There were significant differences in the antiemetic efficacy rate among the first, second and third periods. The antiemetic efficacy of granisetron decreased significantly by repeated CAF chemotherapy.

Adult↗
PubMed1997

[Internationalization of the English-language journals in Japan in life sciences].

The purpose of this study is to analyze the characteristics of the internationalization of four English-language journals in Japan in life sciences based on the papers published in each of journals during the period of 1992-1994. The journals were identified by impact factors (IFs) according to the Journal Citation Reports (JCR) for the 1994 volume. The mean IFs to the top 25 citing and cited journals were compared in order to evaluate their international contribution. The journals (Journal of Biochemistry, Japanese Journal of Cancer Research, Japanese Journal of Physiology) published in Japan did not have an international reputation except for international immunology in terms of IFs and geographic distribution of authors. The editorial policy and strategy have to be established in order to receive a large international readership.

Bibliometrics↗
PubMed1997

[Secondary hepatic resections in a case of sigmoid colon cancer with multiple liver metastasis (H3) after successful continuous hepatic artery infusion chemotherapy oriented by in vitro chemosensitivity test].

A 43-year-old woman was admitted to our hospital for sigmoid colon cancer with multiple liver metastasis (H3). As preoperative CTAP (CT during arterial portography) examination showed 23 metastatic nodules in the whole liver, hepatic resections were not indicated. Angiographic findings showed that right and left hepatic arteries branched separately from the celiac artery. Sigmoid colon resection with D3 lymph node dissection and catheterization to the right hepatic artery via gastroduodenal artery were undertaken as a first operation. Continuous hepatic artery infusion chemotherapy with MMC, 5-FU oriented by in vitro chemosensitivity test (SDI test: Succinic Dehydrogenase Inhibition test) of primary tumor was performed 7 days after the first operation. After administration of MMC (40 mg) and 5-FU (16,500 mg), metastatic nodules in the right lobe almost disappeared except for the one tumor of S7, but the size and number of the nodules in the left lobes increased. At 10 months after the first operation, the left hepatic lobectomy and extirpation of only one tumor in the right lobe (S7) underwent. This case showed the usefulness of continuous hepatic artery infusion chemotherapy oriented by in vitro chemosensitivity test for multiple liver metastasis from colon cancer.

Adenocarcinoma↗
PubMed1997

[Clinical results of combination chemotherapy with cisplatin, vinblastine and bleomycin (pvb) for advanced testicular cancer: evaluation of risk criteria].

Between 1982 and 1991, 24 patients with advanced testicular germ cell tumor were treated by combination chemotherapy with cisplatin, vinblastine and bleomycin (PVB). Based on short-term efficacy of the PVB regimen and long-term prognosis in our patients, we evaluated 4 risk criteria proposed by Indiana University, National Cancer Institute (NCI), Memorial Sloan-Kettering Cancer Center (MSKCC) and European Organization for Research and Treatment of Cancer (EORTC). Clinical staging were IIA in 8 patients, IIB in 8, IIIA in 1, IIIB in 5 and IIIC in 2. Metastases included retroperitoneal lymph node in 20 cases (> 5 cm in 10), lung in 6, bone and liver in each 1. Complete response (CR) was obtained in 12 (50%) patients and partial response (PR) in 9 (38%). According to the stage and metastatic site, CR was achieved in 75%, 38% and 38%of the stage IIA, IIB and III tumors, respectively, and in 60% and 50% of retroperitoneal and pulmonary metastases, respectively. However, neither CR nor PR was recognized for live and bone metastases. Prognosis was assessed with a mean followup period of 88.5 months. Although all 12 patients with CR were alive, 4 of the 9 with PR and all patients on whom the drug was ineffective died of cancer. Accuracy in predicting prognosis was 82%, 75%, 74%, and 63% using the MSKCC, Indiana, NCI and EORTC risk criteria, respectively.

Adolescent↗
PubMed1997

Inhibition of accelerated coronary atherosclerosis with short-term blockade of intercellular adhesion molecule-1 and lymphocyte function-associated antigen-1 in a heterotopic murine model of heart transplantation.

BACKGROUND: Graft arteriopathy limits the long-term survival of allograft recipients. Cardiac allografts in mice develop graft coronary arteriopathy similar to that observed in clinical chronic rejection in human beings. We found that antiintercellular adhesion molecule-1 (ICAM-1) and antilymphocyte function-associated antigen-1 (LFA-1) monoclonal antibodies (mAbs) induce immunologic tolerance to mice with cardiac allografts. METHODS: To evaluate the effects of short-term administration of anti-ICAM-1 plus anti-LFA-1 mAbs in preventing graft arteriopathy, we treated C3H/He mice that received cardiac allografts from BALB/c mice with anti-ICAM-1 plus anti-LFA-1 mAbs for the first 5 days after transplantation. For control studies, FK506 was administered daily to other allograft recipients. Allografts were harvested on day 60. Immunohistochemical analysis was used to detect the expression of ICAM-1 and vascular cell adhesion molecule (VCAM)-1, and in situ reverse transcriptase polymerase chain reaction was performed to detect platelet-derived growth factor (PDGF)-B mRNA expression in the graft arteries. RESULTS: Allografts from mice that received FK506 treatment daily showed significant neointimal thickening with increased expression of ICAM-1, VCAM-1, and PDGF-B mRNA, whereas there was almost no intimal thickening and ICAM-1, VCAM-1, and PDGF-B mRNA expression in the mice that received anti-ICAM-1 plus anti-LFA-1 mAbs. CONCLUSION: Short-term blockade of ICAM-1 and LFA-1 adhesion not only induces immunologic tolerance to cardiac allografts but also prevents graft arteriopathy.

Animals↗
PubMed1997

Assessment of tolerance induction to cardiac allograft by anti-ICAM-1 and anti-LFA-1 monoclonal antibodies.

BACKGROUND: Transplantation tolerance is induced by selective manipulation of intercellular adhesion molecule-1 (ICAM-1) and leukocyte function-associated antigen-1 (LFA-1) molecules in the adult mouse. However, the mechanism of this tolerance induction has not been elucidated. METHODS AND RESULTS: C3H/He mice were heterotopically transplanted with BALB/c hearts; recipients were injected with anti-ICAM-1 and anti-LFA-1 monoclonal antibodies (mAbs). Of 3-day administration of both mAbs at 50 micrograms/day, all recipients accepted cardiac allografts indefinitely (n = 20); this also occurred in 5 of 10 mice that were not treated until day +4 or day +5. Long-term cardiac allograft acceptance was also achieved in thymectomized recipients. This tolerance could not be abrogated by the injection of either naive recipient lymphocytes or sensitized lymphocytes taken from the recipient strain mice that rejected the same donor strain hearts. Mixed lymphocyte culture showed that splenocytes from allograft recipient mice treated with the mAbs showed normal allogeneic response without donor alloantigen specificity. CONCLUSIONS: These results demonstrate the unique character of the peripheral tolerance induced by anti-ICAM-1 and anti-LFA-1 mAbs. Further studies are required to elucidate detailed mechanisms of transplantation tolerance development.

Animals↗