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Biomedical subjects

M Nagumo

Publications and source records attributed to M Nagumo.

At least 37 records · Page 2Linked to original sources
PubMed1998

Changes in bite force and occlusal contacts in patients treated for mandibular prognathism by orthognathic surgery.

PURPOSE: The purpose of this study was to evaluate changes in bite force and occlusal contacts before and after orthognathic surgery in patients with mandibular prognathism and to compare the findings with those in controls with normal occlusion. PATIENTS AND METHODS: Bite force and occlusal contacts were analyzed in 23 (7 male and 16 female) patients with mandibular prognathism before and after sagittal split ramus osteotomy, and in 20 (10 male and 10 female) controls with normal occlusion. The bite force and occlusal contacts were simultaneously measured by a computerized occlusal analysis system, the T-Scan system, immediately before surgery, and at 6 weeks, 3 months, 6 months, and 1 year postoperatively. RESULTS: Both the bite force and occlusal contacts in the patients were significantly less than those in the controls before surgery. Although both the bite force and occlusal contacts in the patients were improved by the orthognathic surgery, neither approached the level in the controls within 1 year. Bite force was correlated with the number of occlusal contacts in both patient and control groups. CONCLUSION: The postoperative masticatory function does not reach control levels even 1 year after the orthognathic surgery for mandibular prognathism. Therefore, further adjustment of the occlusion should be considered before the end of treatment.

Adult↗
PubMed1998

Burkitt's lymphoma involving the mandible: report of a case and review of Japanese cases.

A Japanese case of Burkitt's lymphoma is presented. The intraoral and panoramic images showed alveolar bone destruction with an infiltrative border, displacement of lower molars, root resorption, and loss of lamina dura and the follicular cortex of a developing tooth, similar to descriptions in previous reports. Computed tomography revealed that a primary lesion occupied the mandible and extended to the muscles of facial expression and to the sublingual and submandibular spaces. Another soft tissue mass was evident in the contralateral parapharyngeal space. Results of a survey of the Japanese literature are also presented; they indicate differences in the clinical features between Japanese cases and African and American cases of Burkitt's lymphoma.

Anti-Inflammatory Agents↗
PubMed1998

Recombinant human bone morphogenetic protein-2 stimulates osteoblast differentiation and suppresses matrix metalloproteinase-1 production in human bone cells isolated from mandibulae.

Bone morphogenetic protein (BMP), a member of the transforming growth factor superfamily, is one of the most potent growth factors that stimulate osteoblast differentiation and bone formation. We investigated the effects of recombinant human BMP-2 (rhBMP-2) on osteoblast differentiation and matrix metalloproteinase-1 (MMP-1) production in human bone cells (HBC) isolated from mandibulae of 3 adult patients. rhBMP-2 at concentrations over 50 ng/ml significantly stimulated alkaline phosphatase activity and parathyroid hormone (PTH)-dependent 3', 5'-cyclic adenosine monophosphate accumulation, which are early markers of osteoblast differentiation, in HBCs. rhBMP-2 (500 ng/ml) also enhanced the level of PTH/PTH related-peptide receptor mRNA expression in HBCs. Although neither HBCs untreated nor treated with rhBMP-2 produced measurable amounts of osteocalcin, which is a marker of more mature osteoblasts, 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] induced ostocalcin mRNA expression and its protein synthesis in these cells. rhBMP-2 inhibited 1,25(OH)2D3-induced osteocalcin synthesis in HBCs at both the mRNA and protein level. rhBMP-2 also significantly suppressed MMP-1 production and MMP-1 mRNA expression at concentrations over 500 ng/ml. These results suggest that rhBMP-2 exerts anabolic effects on human osteoblastic cells derived from mandibulae by stimulation of osteoblast differentiation and down-regulation of MMP-1 synthesis.

Adult↗
PubMed1998

[A case of surgical treatment for giant pseudoaneurysm of the left ventricle after myocardial infarction].

A 70-year-old male was admitted for acute postero-inferior myocardial infarction. In cardiac catheterization one month later, there was narrowing of the distal left circumflex artery and the aneurysm of the postero-inferior wall of the left ventricle. The echocardiogram strongly suggested the pseudoaneurysm of the left ventricle. At operation, a large postero-inferior aneurysm was densely adherent to the pericardium. After cardiopulmonary bypass was established, the aorta was cross-clamped and cold cardioplegia was infused, the aneurysm was opened without excision of it. There was a 4 cm by 5 cm defect in the postero-inferior wall of the left ventricle, which communicated with the cavity of the aneurysm. The defect was closed with a patch. Pseudoaneurysm of the left ventricle was diagnosed by histological examination. The postoperative course was uneventful and he discharged on 29th day after surgery.

Aged↗
PubMed1997

Osseointegration of dental implants in rabbit bone with low mineral density.

PURPOSE: The purposes of this study were to establish an experimental animal model with bone of low mineral density, and to then investigate the reaction of the bone-implant interface in these experimental animals. MATERIALS AND METHODS: To prepare the experimental model, rabbits were ovariectomized and fed a 0.15% low-calcium diet. The bone mineral density (BMD) of the tibia was periodically measured by dual-energy X-ray absorptiometry. Approximately 1 month after the introduction of the low-calcium diet, when BMD had decreased to about 12% less than that of control rabbits, a titanium implant (TI) was inserted into the tibia of each rabbit. At 2, 4, 8, and 12 weeks after the insertion of the TI, the rabbits were killed, and the reaction of the bone tissue surrounding the TI was examined both histologically and radiographically. RESULTS: The combined ovariectomy and low-calcium diet produced rabbits having bone with low mineral density, and the histologic features of the tibia in these rabbits were consistent with those in human osteoporotic bone. In control rabbits, new bone formation surrounding the TI was evident 2 weeks after its insertion, and the TI surface was almost completely covered with new bone after 8 weeks. In contrast, new bone formation in the experimental rabbits was delayed, but considerable direct bone contact with the TI was observed after 12 weeks. CONCLUSION: These results suggest that osteoporotic bone may affect the healing period of bone tissue after the insertion of dental implants, but that osseointegration of dental implants may be obtained even in osteoporotic bone.

Animals↗
PubMed1997

Clinical trial of recombinant granulocyte colony-stimulating factor for chemotherapy-induced neutropenia patients with oral cancer.

PURPOSE: This study was undertaken to evaluate the efficacy and toxicity of recombinant human granulocyte colony-stimulating factor (rhG-CSF) in reducing neutropenia in patients with oral cancer undergoing intensive chemotherapy. MATERIALS AND METHODS: Patients with chemotherapy-induced neutropenia (< 1 x 10(9)/L) were divided into two groups: control group (n = 13) and rhG-CSF administration group (n = 16). rhG-CSF was administered subcutaneously at a dose of 75 micrograms/day on consecutive days. Peripheral blood cell counts and oral complications were investigated in each group. RESULTS: The duration of neutropenia and absolute neutrophil nadir counts were significantly improved by administration of G-CSF. No consistent effect on thrombocytopenia was noted. Administration of rhG-CSF also reduced the duration and degree of oral complications associated with chemotherapy-induced neutropenia. Intolerable side effects associated with administration of rhG-CSF were not observed. CONCLUSION: It was concluded that rhG-CSF is effective in shortening the duration of neutropenia after chemotherapy at a dose of 75 micrograms/day.

Adult↗
PubMed1997

Positional changes in the mandibular condyle and amount of mouth opening after sagittal split ramus osteotomy with rigid or nonrigid osteosynthesis.

PURPOSE: The purpose of this study was to investigate postoperative positional changes in the mandibular condyle and mouth opening in patients undergoing sagittal split ramus osteotomy with either rigid or nonrigid osteosynthesis. PATIENTS AND METHODS: The forty-six patients with mandibular prognathism underwent sagittal split ramus osteotomy for mandibular set back followed by fixation with one of four methods: circumferential wire (n = 11), lag screw technique (n = 10), positional screw technique (n = 10), or miniplates (n = 15). The changes in the condylar position were assessed by measuring the angle of the condylar long axis (the condylar angle) on submentovertex radiographs. Mouth opening was evaluated by measuring the interincisal distance immediately after the release of maxillomandibular fixation and by monitoring the duration of trismus. RESULTS: Regardless of the procedure used the condylar angle increased in most patients after surgery (80 of 92 condyles). Although the amount of increase tended to be higher with rigid osteosynthesis than with nonrigid osteosynthesis, no significant differences were observed among the groups. Mouth opening was not significantly influenced by the type of osteosynthesis, and no patient complained of limitation 1 year after surgery. CONCLUSIONS: Although inward rotation of the condyle frequently occurs after osteosynthesis regardless of the procedure used, the changes in condylar position are within the range of adaptability of the patient.

Adaptation, Physiological↗
PubMed1997

Cardiac extension of intravenous leiomyomatosis with successful resection.

A case of intravenous leiomyomatosis spreading to the right ventricle is described. A 28-year-old woman had been previously diagnosed as having a smooth muscle tumor of borderline malignancy after hysterectomy for a large uterine tumor, because of its unusual invasive character. Based on the above diagnosis, the patient had been managed clinically as having a uterine sarcoma. One year after her hysterectomy, a local recurrence in the pelvic cavity was detected. Two years later, the tumor appeared as a cardiac tumor causing syncope. The tumor was totally resected in two surgical stages, and the correct diagnosis of an intravenous leiomyomatosis was made. The diagnostic and operative considerations are reviewed and the preferred surgical procedure is discussed.

Adult↗
PubMed1997

Left atrial ball thrombus in a patient without mitral valve disease.

We experienced a large left atrial ball thrombus in a patient without mitral valve disease. By transthoracic echocardiography the mass was appeared to be free-floating and swinging randomly in the left atrium. An urgent operation was performed successfully. Operative findings revealed the mass to be a large ball thrombus loosely attached to atrial wall. We suggest that surgical removal is indicated as soon as possible, because of a very high risk of embolism or circulatory collapse.

Aged↗
PubMed1995

[Effect of autologous platelet rich plasma on adult open heart surgery].

To reduce the rate and the volume of homologous blood transfusion, we have used autologous platelet rich plasma (PRP) in adult open heart surgery. From Jan. 1988 to Jun 1992, 191 patients have underwent open heart surgery of coronary artery disease or valvular heart disease in our institution. We divided these patients into two groups: (1) PRP group; autologous PRP was used in 99 cases, (2) C (Control) group; autologous PRP was not used in 92 cases. Patient characteristics of age, sex, body weight, preoperative hematocrit values, preoperative platelet counts, and CPB time were same in these groups. Intraoperative and postoperative blood loss in PRP group were significantly less than those in C group (376 ml and 458 ml vs 511 ml and 568 ml; p < 0.01). Homologous blood transfusion rate (number of patients receiving homologous blood transfusion/all patients) was lower in PRP group (11.1% vs 32.6%; p < 0.01). The volume of homologous blood transfusion in the patients receiving transfusion were smaller in PRP group (7.5 U vs 13.3 U; p < 0.05). We conclude autologous PRP is useful in adult open heart surgery to reduce the perioperative blood loss, the rate, and the volume of homologous blood transfusion.

Adult↗
PubMed1994

Expression of collagen species in a cartilaginous tumor derived from a human osteogenic sarcoma.

We have succeeded in transplanting human osteogenic sarcoma into nude mice. Morphologically, the transplanted tumor is chondrosarcoma and manifests calcification, but not ossification. This tumor is thought to be an excellent model for studying the process of morbid endochondral calcification. In this study, we have used in situ hybridization to examine expression of collagen type I, II, and III mRNAs in this tumor. In situ hybridization was carried out using biotinylated DNA probes. Hybridized probes were detected using a streptavidin-biotin-alkaline phosphatase reagent. The results showed that collagen type I and II mRNAs were produced by cells of the transplanted tumor. Collagen type I mRNA was chiefly localized in the marginal region of the tumor. Collagen type II mRNA, which was predominantly found in the premineralized region of the transplanted tumor, gradually decreased toward the mineralized region. Collagen type III mRNA was not expressed in the transplanted tumor. These results suggest that the character of progenitor chondrogenic cells might be transferred to the transplanted tumor, and that the tumor cells may change the expression of collagen genes with the differentiation or maturation.

Animals↗
PubMed1994

Role of intracellular SOD in protecting human leukemic and cancer cells against superoxide and radiation.

Many anticancer drugs have been shown to produce superoxide anion (O2.-) and seem to involve O2.- in their mode of action. Ionizing radiation provokes the decomposition reaction of water, producing a variety of reactive oxygen species, including O2.-. The finding that cancer cells are generally low in SOD activity may offer a theoretical base for radiation therapy and chemotherapy. The purpose of this study was to examine the protective effect of intracellular SOD against cytotoxicity induced by O2.- or radiation and to investigate whether exogenous SOD can protect cells from O2.-(-) and radiation-induced cytotoxicity. For this purpose, xanthine (X) and xanthine oxidase (XOD) were employed as an O2.- (-)generating system, and a linear accelerator was used for ionizing radiation. Cytotoxicity against monolayer cancer cell lines and leukemic cell lines was estimated by measuring the release of lactate dehydrogenase from these cells. The results revealed that the resistibilites to X- and XOD-generated O2.- and radiation correlated with intracellular Cu. Zn-SOD levels and that exogenous SOD could only slightly reduce X- and XOD-induced cytotoxicity while having no influence on radiation-induced cytotoxicity. Thus, intracellular SOD may play a central role in protecting cancer cells against reactive oxygen species generated by anticancer drugs and radiation.

Carcinoma, Squamous Cell↗
PubMed1994

Downregulation of c-myc expression by tumor necrosis factor-alpha in combination with transforming growth factor-beta or interferon-gamma with concomitant inhibition of proliferation in human cell lines.

The modulation of cell growth by tumor necrosis factor-alpha (TNF-alpha), or TNF-alpha in combination with transforming growth factor-beta (TGF-beta) or interferon-gamma (IFN-gamma) was investigated. TNF-alpha inhibited the proliferation of U937 cells, a monocytic leukemic cell line, and of NA cells that were established from oral squamous cell carcinoma. TNF-alpha showed a cytolytic effect on NA cells in the presence of actinomycin D. TNF-alpha in combination with TGF-beta and TNF-alpha combined with INF-gamma synergistically inhibited the cell proliferation of U937 and NA cells, respectively. TNF-alpha dose-dependently reduced c-myc mRNA expression of U937 and NA cells within 1 h. The combination of TNF-alpha and TGF-beta in U937 cells and that of TNF-alpha and IFN-gamma in NA cells cooperatively reduced the expression of c-myc mRNA. TNF-alpha had little or no effect on the half-life of c-myc mRNA, indicating that c-myc mRNA expression was reduced at transcriptional level. Cycloheximide did not mediate the inhibition of c-myc gene expression, suggesting that the TNF-alpha action was independent of de novo protein synthesis. These data suggest that the reduction of c-myc gene at transcriptional level by TNF-alpha or TNF-alpha in combination with TGF-beta or IFN-gamma plays a primary role in the inhibition of cell growth at an early stage.

Cell Division↗
PubMed1994

Biological and morphological characteristics of a transplanted cartilaginous tumor derived from a human osteogenic sarcoma.

A cartilaginous tumor derived from a human osteogenic sarcoma of the mandible has been maintained by serial passage to nude mice. Tumor growth was multilobular. Radiopaque spots were seen scattered throughout the tumor at three months after transplantation. Both light and electron microscopic examination at three months revealed that the tumor contained cartilaginous cells at various stages of differentiation. There was metachromasia throughout tumor lobules except in the marginal region. Von Kossa staining was positive in the central region. Ultrastructural study identified four subtypes of chondrocytic cells of a neoplastic nature. In the extracellular matrix around hypertrophic cells, matrix vesicles were observed with mineral deposits. Alkaline phosphatase was found on the plasma membrane and Golgi complexes of hypertrophic cells, and on matrix vesicles. Thus cell lineage and the manner of calcification of the transplanted tumor were similar to those of epiphyseal growth cartilage.

Adult↗
PubMed1993

Prolonged infection of the floor of the mouth in hyperimmunoglobulinemia E (Buckley's syndrome). Report of a case.

A case of prolonged infection of the floor of the mouth with a generalized eczematous dermatitis in a 13-year-old boy is described. Immunologic examination revealed markedly elevated serum concentration of immunoglobulin E (IgE) and impaired neutrophil chemotaxis. The disorder was diagnosed as the hyperimmunoglobulinemia E (Buckley's syndrome) and was successfully treated with high doses of antibiotics and human immunoglobulin.

Adolescent↗