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Biomedical subjects

Y Ohmori

Publications and source records attributed to Y Ohmori.

At least 163 records · Page 9Linked to original sources

[Inducing effect of periodontopathic bacteria on activation of macrophage functions and production of interleukin-1 by mouse peritoneal macrophages].

Periodontal disease is thought to be initiated by a bacterial infection and subsequently developed by immunopathological mechanisms thorough host-parasite interactions. The macrophage and lymphocyte are the major functional cell types in the lesion of the disease and participate in tissue destruction and alteration of the periodontal connective tissue as well as in host defense mechanisms. However, the detailed implications of macrophages in development of the disease is still unclear. The aim of this study was to gain more understanding of the functional role of macrophages in periodontal disease. In this study, we examined the inducing effects of sonicated extracts from some gram-negative and gram-positive bacteria associated with the pathogenesis of periodontal disease, including Bacteroides gingivalis, Fusobacterium nucleatum, Haemophilus actinomycetemcomitans, and Actinomyces viscosus, on activation of macrophage functions and IL-1 production by the macrophages from the mouse peritoneum. At a dose as low as 1 microgram/ml (dry weight) sonicated extracts from B. gingivalis induced an increase in acid phosphatase activity and in glucose consumption of mouse peritoneal macrophages in vitro. A significant increase in the acid phosphatase and in glucose consumption was observed in the cultures at 24 h and 48 h, respectively, after the addition of the sonicate. Sonicated extracts from A. viscosus, a gram-positive bacterium, as well as B. gingivalis, F. nucleatum, and H. actinomycetemcomitans, gram-negative ones, were able to induce the increase in acid phosphatase activity and in glucose consumption of the macrophages. These periodontopathic bacteria were found to strongly induce IL-1 production by the macrophages as early as 24 h after addition of the sonicates. A significant increase in the IL-1 production was observed at a dose of 1 microgram/ml of the sonicates. The inducing ability was equivalent to 1 microgram/ml Escherichia coli lipopolysaccharide. The highest production of IL-1 was observed in the macrophages treated with H. actinomycetemcomitans among these sonicates. Sonicated extracts from both gram-negative and gram-positive bacteria were able to induce the IL-1 production by macrophages from C3H/HeJ mice, which are LPS low-responders. These results suggest that periodontopathic bacteria have potent ability to induce macrophage activation and IL-1 production and that the activated macrophages may play an important role in development of periodontal disease.(ABSTRACT TRUNCATED AT 400 WORDS)

Actinomyces↗

Effects of recombinant human interleukin 1 alpha and interleukin 1 beta on cell growth and alkaline phosphatase of the mouse osteoblastic cell line MC3T3-E1.

Recombinant human interleukin 1 (rhIL-1)alpha and rhIL-1 beta were examined for their effects on DNA synthesis, cell growth and alkaline phosphatase activity of the mouse osteoblastic cell line MC3T3-E1. The relative activity of rhIL-1 alpha and rhIL-1 beta was compared in terms of the units which induced half-maximal [3H]thymidine uptake into mouse thymocyte cultures exposed to IL-1. Both rhIL-1 alpha and rhIL-1 beta significantly inhibited DNA synthesis and division of the cells in a concentration- and cultivation time-dependent fashion. In contrast, rhIL-1 alpha and rhIL-1 beta markedly increased alkaline phosphatase activity, which is a marker of osteoblastic differentiation. This activity in cells treated with rhIL-1 alpha and rhIL-1 beta increased about 2.0- and 1.7-fold, respectively, compared with that of control cultures. Inhibition of the DNA synthesis and stimulation of alkaline phosphatase activity by both types of rhIL-1 were completely neutralized by treatment with their respective polyclonal antisera. Also, inhibition of DNA synthesis was unaffected by the addition of cyclooxygenase and lipoxygenase inhibitors, and stimulation of alkaline phosphatase activity was unaffected by the addition of indomethacin. These results indicate that both rhIL-1 alpha and rhIL-1 beta have qualitatively similar biological effects on osteoblastic cells. They also suggest that IL-1 is an important modulator of the growth and differentiation of osteoblasts.

Alkaline Phosphatase↗

Location of motoneurons supplying upper neck muscles in the chicken studied by means of horseradish peroxidase.

The distribution of motoneurons innervating the upper cervical muscles, biventer cervicis, splenius capitis, complexus, rectus capitis dorsalis, rectus capitis lateralis, and rectus capitis ventralis in the chicken was examined by retrograde transport of horseradish peroxidase. Labeled motoneurons supplying upper neck muscles ranged from 30 to 60 micron in diameter and were located within two subnuclei in the brainstem. The rostrocaudal distributions of motoneurons projecting to individual cervical muscles ranged from 3 to 9 mm in length, both rostral and caudal to the obex. Detailed analysis of the data showed that the more dorsally positioned subnucleus projected mainly to the hypaxial muscles, i.e., the rectus capitis ventralis and lateralis, whereas the ventral subnucleus supplied chiefly the epaxial muscles, i.e., the biventer cervicis and splenius capitis. The complexus and rectus capitis dorsalis were innervated by both of these subnuclei. Historically these dorsal and ventral subnuclei, respectively, have been called the nucleus hypoglossus ventralis and the nucleus hypoglossus ventralis ventrolateralis. In view of the observation that these nuclei do not undergo retrograde degeneration following section of the hypoglossal nerves, this older nomenclature is misleading. In agreement with other authors, we suggest that these motoneuron groups should be collectively referred to as the nucleus supraspinalis.

Animals↗

Inductive effect of recombinant human interleukin-1 alpha and beta on differentiation of macrophage-like tumor cell line P388D1.

We used the mouse monocyte/macrophage-like tumor cell line P388D1 to test whether or not interleukin-1 (IL-1) stimulates differentiation of monocyte/macrophage progenitors. Incubation of these cells with recombinant human interleukin-1 (rhIL-1) alpha and beta resulted in their increased adherence, stimulation of nonspecific esterase activity, and increased Fc rosette formation. rhIL-1s inhibited cell growth and stimulated Fc rosette formation in a dose-dependent fashion. The cell growth inhibition due to rhIL-1s depended on the concentration of serum in culture medium. Synergism between rhIL-1 and calcium ionophore A23187 was found for the cell growth inhibition and Fc rosette formation. The presence of ethylene glycol bis- (beta-aminoethyl ether) N,N,N,N,-tetraacetic acid(EGTA) in the medium abolished the stimulatory effect of rhIL-1 on Fc rosette formation of the cell line. These results demonstrate that rhIL-1s are a potent inducer of the differentiation of the macrophage-like tumor cell line P388D1.

Animals↗

The effect of cyclosporine on mortality and renal function in living related pediatric kidney transplant recipients.

The outcome, incidence of acute rejection episodes, complications and cyclosporine (CyA) induced nephrotoxicity were studied in 10 pediatric kidney transplant recipients who were grafted from one-haplotype indentical parent with immunosuppression of CyA and prednisolone (Pred). Excellent patient and graft survival could be achieved in this population with low incidences of acute rejection or serious complications as when compared with the results of azathioprine (AZ) treated pediatric patients. With a mean follow-up of 12.9 months (range 1 to 50 months), the patient survival rate was 100 per cent and the graft survival rate was 100, 84, 84 and 84 per cent at 1, 2, 3 and 4 years post transplantation, respectively. Serum creatinine levels in the group were 0.97, 1.17, 1.14 and 1.2 mg/dl at 3, 6, 12 and 24 months post transplantation, respectively. The incidence of treated acute rejection episodes was 20 per cent (2 out of 10) in the CyA-treated children, whereas it was 53 per cent (9 of 17) in the Az-treated children. Five children who had undergone transplant surgery before they were 11 years old displayed linear growth in height after their transplantation. There have been no opportunistic infections, aseptic necrosis or peptic ulcers in this group and cyclosporine nephrotoxicity has not been a serious problem in the pediatric recipients. Only 10 per cent (1 out of 10) of the recipients displayed acute nephrotoxicity and only one recipient has converted from CyA + Pred to CyA + AZ + Pred (Three drug therapy) due to persistent nephrotoxicity.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

A kidney transplant recipient with renal cell carcinoma derived from a native kidney.

A case of renal cell adenocarcinoma which originated from a left native kidney following kidney transplantation, with widespread metastases, including multiple bone and liver metastases, is presented herein. An extensive clinical investigation, including bone marrow biopsy, liver biopsy, abdominal computerized tomography, excretory urography and examination of the gastrointestinal tract failed to determine the site of the primary lesion in this patient. Examination at autopsy revealed a small adenocarcinoma of the left native kidney with lobulated nodular capsular invasion and metastases to the bone and liver.

Adult↗

Experience with 247 living related donor nephrectomy cases at a single institution in Japan.

There is currently much concern over the morbidity and mortality of donors undergoing nephrectomy for living related renal transplants. Between April, 1970 and July, 1986, 247 cases of living related renal transplants were performed at the Second Department of Surgery, Kyoto Prefectural University of Medicine. The average age of the donors was 50.3 +/- 9.7 years, 81 per cent of the donors being parents of the recipients. Minor abnormalities which did not affect the donors suitability were found in 71 cases. Nephrectomies were performed extraperitoneally in all cases. Peri-operative complications, including wound complications in 13 cases, urinary infection in 12 cases and pulmonary complications and arrhythmia in 4 cases, were considered to be minor in nature. A variety of renal function tests, carried out two weeks after nephrectomy revealed normal levels, although they had become slightly worse than those estimated pre-operatively. Long-term sequelae in the follow-up period from 18 months to 16 years and 2 months, was studied on 124 donors who answered questionnaires. Currently, there are 5 late deaths, none of which are directly related to the nephrectomy. Of the 124 donors, 85.5 per cent stated that there had been no change in their physical states following surgery. Pain or a feeling of discomfort at the wound site was reported by 10 donors (8.1 per cent) and hypertension was observed only in 3 (2.4 per cent). No major complication directly related to the donor nephrectomy was found, except for one case of incisional hernia.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Stimulatory effect on bone resorption of interleukin-1-like cytokine produced by an osteoblast-rich population of mouse calvarial cells.

We reported previously that an osteoblast-rich population of mouse calvarial cells treated with lipopolysaccharide produced on interleukin-1 (IL-1)-like cytokine that closely resembles IL-1. In the present study, we examined whether or not the IL-1-like cytokine stimulates bone resorption. As a result we found that the cytokine stimulate bone resorption significantly, and the stimulatory effect was dependent on cytokine dose and length of culture time. The stimulation of bone resorption and IL-1-like cytokine activity appear to be in parallel. Since the stimulatory effect of the cytokine was not abolished in the presence of indomethacin, the cytokine may stimulate bone resorption in a prostaglandin metabolite-independent manner. These results suggest the possibility that the IL-1-like cytokine may be involved as an autoregulatory factor in the bone-remodeling system.

Animals↗

Effect of cyclosporine on the endocrine and exocrine pancreas in kidney transplant recipients.

In order to assess whether cyclosporine (CsA) affects the endocrine and exocrine pancreas, 105 patient courses comprised of 87 living related donor (LRD) and 18 cadaver donor (CAD) transplants treated with cyclosporine and prednisolone (Pred) were compared with the results of historical controls of 170 LRD and 10 CAD transplants treated with azathioprine (Az) and Pred. All of the recipients were followed for over 6 months after transplantation. There were no differences in age, sex, Broca index, family history, and preoperative evaluation on diabetic dispositions between the two treatment groups. The incidence of diabetes mellitus (DM) requiring insulin therapy was higher in CsA-treated recipients (18/105, 17.1%) than in Az-treated recipients (23/180, 12.8%; P less than 0.05), although both the daily Pred and cumulative doses of methylprednisolone (MP) at the onset of DM were significantly smaller in the CsA group than in the Az group (26.1 +/- 2.2 mg v 41.4 +/- 3.4 mg, P less than 0.01 and 3,086 +/- 626 mg v 7,133 +/- 1,129 mg, P less than 0.01, respectively). Diabetic patients with CsA showed higher levels of blood glucose (401 +/- 46 mg/dL), but lower amounts of urinary glucose (40 +/- 4.3 g/d) compared with patients treated with Az (239 +/- 31 mg/dL, and 61.4 +/- 4.6 g/d, respectively, P less than 0.05). In the CsA group, the onset of DM was related to high CsA plasma trough levels (greater than 350 ng/mL) in 23% of patients. Insulin could be withdrawn within 3 months in six of eight patients who had been converted from CsA to Az.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗

Bacteroides gingivalis fimbriae stimulate production of thymocyte-activating factor by human gingival fibroblasts.

In a previous report (Y. Ohmori, S. Hanazawa, S. Amano, T. Miyoshi, K. Hirose, and S. Kitano, infect. Immun. 55:947-954, 1987), we showed that human gingival fibroblasts spontaneously produce thymocyte-activating factor (FTAF), which stimulates mitogen-induced thymocyte proliferation. In the present study, we examined the effect of Bacteroides gingivalis fimbriae on FTAF production by the cells, because the fimbriae may be involved in attachment of the organism to periodontal tissues. We show here that the fimbriae bind to the cells, which may subsequently lead to the stimulation of FTAF production by the cells.

Animals↗