Biomedical subjects

M Oda

Publications and source records attributed to M Oda.

At least 55 records · Page 3Linked to original sources

PubMed2001

Reconstruction of the primate mandible with a combination graft of recombinant human bone morphogenetic protein-2 and bone marrow.

PURPOSE: This study evaluated whether recombinant human bone morphogenetic protein-2 (rhBMP-2) can be used to regenerate a resected part of the mandible in a primate model. MATERIALS AND METHODS: Segmental bone defects were created surgically in the mandible of Japanese monkeys. rhBMP-2 was suspended in a solution of polyglycolic co-lactic acid (PGLA) and lyophilized to make a BMP/PGLA complex. The rhBMP-2/PGLA complex and autogenous bone marrow in ratios of 3:0, 2.5:0.5, or 2:1 (vol:vol) were each implanted into the bone defects in 3 monkeys. Bone marrow or P(GLA alone were each implanted in 1 monkey as a control. The animals were killed 16 weeks after surgery, followed by radiologic and histologic evaluation. RESULTS: The implantation of bone marrow alone succeeded in reconstruction of the mandible, but the implantation of the rhBMP-2/PGLA complex showed only a small amount of bone formation. The combination graft of rhBMP-2/PGLA and bone marrow resulted in a greater degree of bone formation; especially the 2:1 combination showed the same result as only bone marrow implantation. CONCLUSION: The combination graft of rhBMP-2 and bone marrow, which requires only a small amount of bone marrow, was a reliable method for reconstruction of mandibular segmental defects in this animal model.

Animals↗

PubMed2001

Secondary sclerosing cholangitis and portal hypertension after O157 enterocolitis: Extremely rare complications of hemolytic uremic syndrome.

The authors experienced an extremely rare case of secondary sclerosing cholangitis and portal hypertension developed as late complications of hemolytic uremic syndrome (HUS) owing to Escherichia coli O157:H7 in a 2-year-old boy. HUS after E coli O157 infection is the most frequent cause of acute renal failure in childhood and occasionally is accompanied by extrarenal complications such as encephalopathy, cardiomyopathy, ischemic colitis, and pancreatitis. Rarely, late colonic stenosis may develop secondary to the ischemic damage. Sclerosing cholangitis and subsequent cirrhosis with portal hypertension are very uncommon as late complications of HUS. To our knowledge, such a case has not been previously reported in the literature. J Pediatr Surg 36:1838-1840.

Child, Preschool↗

PubMed2001

Bone regeneration using recombinant human bone morphogenetic protein-2 (rhBMP-2) in alveolar defects of primate mandibles.

The efficacy of bone morphogenetic protein (BMP) for bone reconstruction has been widely studied in numerous animal experiments, but insufficient information exists about its ability to regenerate bone in primates. The purpose of this study was to evaluate the effects of recombinant human BMP-2 (rhBMP-2) on bone formation in alveolar bone defects in the mandibles of young primates. Marginal bone defects were created in the mandibles of nine 5-year-old rhesus monkeys and rhBMP-2 permeated in a polylactic-co-glycolic acid-coated gelatin sponge (PGS) was implanted into the bone defects. The resected bone treated with rhBMP-2 regenerated completely at 12 weeks postoperatively, and remodelling and consolidation of new bone were seen histologically. This study provides evidence of considerable bone regeneration in alveolar defects after surgical implantation of rhBMP-2 in non-human primates. This technique may be an effective alternative to autogenous bone grafts for reconstructive surgery in clinical practice.

Absorbable Implants↗

PubMed2001

Intrathoracic free musculocutaneous flap after open-window thoracostomy for chronic empyema.

An 85-year-old man was suffering from right pyothorax caused by methicillin-resistant staphylococcus aureus (MRSA). The empyema cavity was closed by intrathoracic implantation of a free rectus abdominis musculocutaneous (MC) flap using microvascular surgery 2 months after open-window thoracostomy (OWT). Compared with a pedicled MC flap, a free flap has the advantage that it can close a larger empyema cavity since the whole flap can be inserted into the cavity. Although the use of a free MC flap requires a two-stage operation, this method is believed to be more successful for controlling chronic empyema than any other established procedure, including decortication, thoracoplasty or pleuropneumonectomy.

Aged↗

PubMed2001

Can tumor size be a guide for limited surgical intervention in patients with peripheral non-small cell lung cancer? Assessment from the point of view of nodal micrometastasis.

OBJECTIVE: We sought to determine the critical diameter of a peripheral non-small cell lung cancer tumor less than which no evidence of nodal micrometastasis is present. METHODS: Samples of 3081 lymph nodes from 181 patients with stage I peripheral lung cancer (155 with adenocarcinoma and 26 with squamous cell carcinoma) who had undergone complete resection with systematic lymphadenectomy were used in the study. In the samples immunohistochemical staining for cytokeratin was performed. The expression of vascular endothelial growth factor (VEGF) at primary sites was also immunohistochemically assessed. RESULTS: Nodal micrometastasis was detected in 44 patients. The mean tumor sizes were 2.2 +/- 1.3 cm (range, 1.0-7.0 cm) in nodal micrometastasis-positive adenocarcinoma, 2.1 +/- 0.9 cm (range, 0.5-6.0 cm) in nodal micrometastasis-negative adenocarcinoma, 4.8 +/- 2.3 cm (range, 2.2-10.0 cm) in nodal micrometastasis-positive squamous cell carcinoma, and 3.2 +/- 2.1 cm (range, 0-9.0 cm) in nodal micrometastasis-negative squamous cell carcinoma. The tumor size in the nodal micrometastasis-positive group tended to be greater than that in the nodal micrometastasis-negative group in squamous cell carcinomas, but there was no significant difference in adenocarcinomas. Nodal micrometastasis was not found in patients with squamous cell carcinoma of 2.0 cm or less in diameter. However, nodal micrometastasis was found in 20% (19/95) of the patients with adenocarcinoma of 1.1 to 2.0 cm in diameter and even in 4 of 11 patients with adenocarcinoma of 1.0 cm or less. Among the patients with nodal micrometastasis, survival of patients with vascular endothelial growth factor overexpression was worse than that of patients without it. The survival of patients with nodal micrometastasis without vascular endothelial growth factor overexpression was comparable with that of patients without nodal micrometastasis. CONCLUSION: A limited surgical intervention without lymphadenectomy is validated for squamous cell carcinoma of 2.0 cm or less without pleural involvement. In adenocarcinoma the tumor size itself is not a reliable guide for nodal micrometastasis status. In patients with nodal micrometastasis with vascular endothelial growth factor overexpression, the risk of systemic disease should be considered.

Adenocarcinoma↗

PubMed2001

Development of composite cultured oral mucosa utilizing collagen sponge matrix and contracted collagen gel: a preliminary study for clinical applications.

A new type of cultured mucosa was developed as a mucosal substitute. This composite cultured oral mucosa (CCOM) was composed of (1) a lamina propria in which fibroblasts were embedded in contacted collagen gel and honeycomb structured collagen sponge and (2) stratified epithelial cell layers on the surface of the cultured lamina propria. CCOM had a well-stratified and differentiated epithelial cell layer, and its involucrin and laminin expression resembled that of normal oral mucosa. Desmosomes were recognizable with transmission electron microscopic examination. In the lamina propria, contracted collagen gel had pooled away from the sponge wall, leaving a sparse structure inside the collagen sponge. Transplantation of CCOM to nude mice was performed by creating full-thickness wound and then applying CCOM (n = 12). Murine skin allograft (n = 4) and no-graft conditions (n = 5) served as controls. The mice were sacrificed for histological evaluation and assessed for wound contraction 28 days after transplantation. The epithelium of the CCOM-treated group had five to 10 cell layers, and the dermis contained many fibroblasts and a large amount of collagen bundles. The wound contraction of the CCOM-treated group was statistically less than that of the no-graft group. These results indicate that CCOM has barrier functions against various stresses and can induce a fibrovascular ingrowth from the surrounding wound bed, and that CCOM could be applied in a clinical setting.

Animals↗

PubMed2001

Oxidative stress and disturbed glutamate transport in hereditary nucleotide repair disorders.

Xeroderma pigmentosum group A (XPA) and Cockayne syndrome (CS) are hereditary DNA repair disorders complicated by progressive neurodegeneration. Here we immunohistochemically examine the in situ expression of materials that are produced by oxidative stress and glutamate transporters (which can contribute to prevention of glutamate neurotoxicity) in the brains of 5 autopsied patients each of XPA, CS, and control groups. All oxidative products, including nitrotyrosine, advanced glycation end product, and 4-hydroxy-2-nonenal-modified protein (HNE) were deposited in large amounts in the globus pallidus of CS patients compared to XPA patients. They were frequently recognized in the pseudocalcified foci and free minerals in the neuropil, and more rarely in foamy spheroids. In addition, the deposition of HNE was observed also in hippocampal and cerebellar dentate neurons of both CS and XPA patients. The expression of glial glutamate transporters, EAAT1 and GLT-1, was affected in the globus pallidus in 5 CS patients and 3 XPA patients. They were also altered in the cerebellar cortex in most of the CS patients. These data suggest that oxidative stress and disturbed glutamate transport may be involved in pallidal and/or cerebellar degeneration in hereditary nucleotide repair disorders.

ATP-Binding Cassette Transporters↗

PubMed2001

Placentomegaly in cloned mouse concepti caused by expansion of the spongiotrophoblast layer.

Hypertrophic placenta, or placentomegaly, has been reported in cloned cattle and mouse concepti, although their placentation processes are quite different from each other. It is therefore tempting to assume that common mechanisms underlie the impact of somatic cell cloning on development of the trophoblast cell lineage that gives rise to the greater part of fetal placenta. To characterize the nature of placentomegaly in cloned mouse concepti, we histologically examined term cloned mouse placentas and assessed expression of a number of genes. A prominent morphological abnormality commonly found among all cloned mouse placentas examined was expansion of the spongiotrophoblast layer, with an increased number of glycogen cells and enlarged spongiotrophoblast cells. Enlargement of trophoblast giant cells and disorganization of the labyrinth layer were also seen. Despite the morphological abnormalities, in situ hybridization analysis of spatiotemporally regulated placenta-specific genes did not reveal any drastic disturbances. Although repression of some imprinted genes was found in Northern hybridization analysis, it was concluded that this was mostly due to the reduced proportion of the labyrinth layer in the entire placenta, not to impaired transcriptional activity. Interestingly, however, cloned mouse fetuses appeared to be smaller than those of litter size-matched controls, suggesting that cloned mouse fetuses were under a latent negative effect on their growth, probably because the placentas are not fully functional. Thus, a major cause of placentomegaly is expansion of the spongiotrophoblast layer, which consequently disturbs the architecture of the layers in the placenta and partially damages its function.

Animals↗

PubMed2001

Successfully resected hepatoblastoma in a young adult with chronic hepatitis B: report of a case.

Hepatoblastoma usually occurs in children, but a few cases have also been reported in adults. We report the unusual case of hepatoblastoma in an 18-year-old adult with chronic hepatitis B. He visited a local hospital with right upper abdominal pain. Abdominal ultrasound showed a large mass in the right lobe of his liver. He was referred to our hospital and admitted for further examination. At admission, liver function tests gave slightly elevated results (aspartate aminotransferase (AST) 103 IU/l, alanine aminotransferase (ALT) 63 IU/l). A test for hepatitis virus revealed that he was a hepatitis B surface antigen (HBsAg) carrier and had experienced seroconversion. His alpha-fetoprotein (AFP) was elevated to 1 548 000 IU/ml. Abdominal ultrasound showed a 109 x 96 x 80-mm mass with mosaic pattern in the right lobe of the liver and right portal vein thrombus. Abdominal computed tomography (CT) demonstrated a large low-density mass occupying the right lobe, with some high-density parts that showed calcification. From these results, we diagnosed hepatoblastoma in a young adult. A right lobectomy was performed. Pathological examination showed a highly differentiated hepatoblastoma. Adjuvant chemotherapy was performed with cisplatin and pirarubicin. The patient has been well and free of recurrence for 12 months, and his AFP level remains almost normal.

Adolescent↗

PubMed2001

The predictive value of vascular endothelial growth factor and nm23 for the diagnosis of occult metastasis in non-small cell lung cancer.

We assessed the association of vascular endothelial growth factor (VEGF) and nm23 expression with occult micrometastasis in lung cancer. As destination sites for micrometastasis, we scrutinized lymph node (LN) and bone marrow (BM) specimens. For LN, 122 stage I patients who had received curative operations were studied. As regards BM, 203 patients in stage I - IV who underwent operations were registered. Immunohistochemical anti-cytokeratin staining was used to detect microdissemination of cancer cells. The VEGF and the nm23 expression at the primary sites were immunohistochemically studied in 285 cases in total. The percentages of the patients with microdissemination were 28.7% for LN and 42.4% for BM. The outcome for the patients with LN or BM microdissemination was significantly worse than that for patients without it. The increased VEGF and the decreased nm23 expression within primary tumors were significantly associated with LN and BM microdissemination. The results indicate possible value of using these biological markers to predict the risk of systemic micrometastasis in non-small cell lung cancer.

Adenocarcinoma↗

PubMed2001

Bronchial sleeve resection with complete preservation of the lung for carcinoma.

Conservative sleeve resection with complete preservation of the lung parenchyma is very rarely applicable for the treatment of bronchial carcinomas. We used this surgical procedure in four patients with bronchial carcinoma in various sites of the central airway, and we obtained successful results. The pathological types were two squamous cell carcinomas and two low-grade malignant tumors (mucoepidermoid carcinoma and adenoid cystic carcinoma). If patients are properly selected, this operative procedure appears to be a safe and radical therapeutic option for the treatment of bronchial neoplasms arising from major bronchi.

Adult↗

PubMed2001

Effects of constituents from the bark of Magnolia obovata on nitric oxide production in lipopolysaccharide-activated macrophages.

The methanolic extract from a Japanese herbal medicine, the bark of Magnolia obovata, was found to inhibit nitric oxide (NO) production in lipopolysaccharide (LPS)-activated macrophages. By bioassay-guided separation, three neolignans (magnolol, honokiol, obovatol) and three sesquiterpenes (alpha-eudesmol, beta-eudesmol, gamma-eudesmol) were obtained as active constituents. A trineolignan (magnolianin), a phenylpropanoid glycoside (syringin), lignan glycosides (liriodendrin, (+)-syringaresinol 4'-O-beta-D-glucopyranoside) and a sesquiterpene (caryophyllene oxide) did not show any activity. On the other hand, sesquiterpene-neolignans (eudesmagnolol, clovanemagnolol, caryolanemagnolol, eudeshonokiol A, eudesobovatol A) showed the strong cytotoxic effects. Active constituents (magnolol, honokiol, obovatol) showed weak inhibition for inducible NO synthase (iNOS) enzyme activity, but potent inhibition of iNOS induction and activation of nuclear factor-kappaB.

Animals↗

PubMed2001

[A case of recurrent ischemic attacks: consecutive diffusion-weighted magnetic resonance imaging].

A 61-year-old man with recurrent ischemic attacks was examined by diffusion-weighted MRI (DWI). He had reversible right hemiparesis and dysarthria five times during admission. DWI was obtained on the first two attacks, the last attack and four days after the last attack. The first two attacks were clinically diagnosed as transient ischemic attack (TIA), and the last attack was cerebral infarction with symptoms persistent for one week with Babinski's sign. In the first and last images the apparent diffusion coefficient (ADC) declined to approximately 80% of the corresponding area. We conclude that different images showed TIA with ADC declining, TIA without ADC declining, the hyperacute phase of cerebral infarction before ADC declining, and cerebral infarction after ADC declining. Consecutive DWIs were helpful to understand the character of recurrent ischemic attacks.

Brain↗

PubMed2001

Clinical analysis and prognostic study of ossified ligamentum flavum of the thoracic spine.

OBJECT: A variety of factors may affect surgery-related outcome in patients with ossification of the ligamentum flavum (OLF) of the thoracic spine. The aim of this study was to determine these factors on the basis of preoperative clinical and radiological findings. METHODS: The authors treated 31 cases of symptomatic thoracic OLF between 1988 and 1999. The following factors were retrospectively studied: patient age, sex, morbidity level, initial symptoms, chief complaint, duration of symptoms, patellar reflex, Achilles reflex, computerized tomography (CT) finding, presence of intramedullary change determined by magnetic resonance imaging, coexistent spinal lesions, preoperative grade, and postoperative grade. A decompressive laminectomy was performed in all cases. In 29 patients (94%) improved symptoms were demonstrated postoperatively. In terms of functional prognosis, the preoperative duration of symptoms was significantly shorter in the group of patients with excellent outcomes than in those with fair outcomes (p < 0.05). No significant difference was observed in the correlation between other factors. To evaluate the degree of preoperative thoracic stenosis and the severity/extent of OLF-induced spinal compression, we used an original OLF CT scoring system. A score of excellent on the CT scale tended to indicate an excellent prognosis (p < 0.01). CONCLUSIONS: Thoracic OLF frequently develops in the lower-thoracic spine in middle-aged men, and it is complicated by various spinal lesions in many cases. Early diagnosis and treatment are important for understanding the clinical symptoms and imaging diagnosis because the present findings suggest that a delay in diagnosis and treatment correlates with the functional prognosis postoperatively.

Adult↗

PubMed2001

[Prefabrication of vascularized bone flap using bone morphogenetic protein (BMP)].

The purpose of this study was to produce newly vascularized bone, and to form the bone into the desired shape. Silicone molds given the shape of a cylinder were used to deliver collagen sheets impregnated with or without rhBMP-2. The superficial inferior epigastric neurovascular bundle in a Wistar rat was identified and sandwiched between the silicone molds. The molds containing collagen sheets impregnated with 10 micrograms of rhBMP-2 were used for the experimental purpose, and those without rhBMP-2 were used as a control. In some of the experimental molds, the neurovascular bundle was ligated at both proximal and distal sites of the molds. After 2 and 4 weeks operation, bone formation was detected macroscopically, radiologically, and histologically. As a result, newly formed bone was observed in all experimental sites without the ligation, and the shape of the bone was exactly the same shape as the silicone mold. Newly formed bone was supplied by the superficial inferior epigastric artery, whereas newly formed bone was not observed in the control and the ligated flaps. Newly vascularized and shaped bone was created by applying an osteoinductive factor to a neurovascular bundle. This study demonstrates that this experimental model could be a therapeutically potential approach for effective bone reconstruction.

Animals↗

PubMed2001

Biological characteristics of carcinomatosa pleuritis in orthotopic model systems using immune-deficient rats.

We assessed the association of vascular endothelial growth factor (VEGF) on the formation of carcinomatosa pleuritis in orthotopic model systems. Immune-deficient rats were inoculated with PC-14 cells into i) a subpleural space of the parietal pleura after pneumonectomy or ii) into the thoracic cavity directly. The rats bearing tumor cells were randomly separated into two groups: non-treatment and treatment with anti-VEGF neutralizing antibody groups. At the time of the autopsy, all rats developed gross pleural dissemination with/without malignant effusions. In the first model, despite no significant difference in the mean volume of the subpleural tumors between the groups, the degree of dissemination was suppressed in the treatment group with less tumor vasculature and with reduced expression of autocrine motility factor receptor (AMFR) in tumor cells. In the second model, although the inhibitory effect on dissemination was not clear, the formation of pleural effusion was inhibited in the treatment group. In addition to the ability of vascular permeability, the results demonstrated here showed the possible association of VEGF with the development of pleural dissemination/metastasis in the context of blood/lymphatic routes and cancer cell motility affected by AMFR.

Adenocarcinoma↗

PubMed2001

[Carinal resection for bronchogenic carcinoma].

The purpose of this study was to evaluate the results of carinal resection for bronchogenic carcinoma in our institute. From 1981 to 1999, 24 carinal resection were performed for squamous cell carcinoma (n = 19), adenoid cystic carcinoma (n = 2), small cell carcinoma (n = 1), adenocarcinoma (n = 1), and mucoepidermoid carcinoma (n = 1). Nineteen underwent sleeve pneumonectomy, 2 had carinal resection without lung resection, 2 had carinal resection with right middle and lower lobectomy, and 1 had wedge pneumonectomy. In the patients with sleeve or wedge pneumonectomy, there were 5 operative death and 3 patients had survived for more than 3 years. Two patients with low-grade malignant tumors underwent carinal resection without lung resection and survived more than 10 years. We believe that limited carinal resection for low-grade malignant tumors are safe and valuable procedure. Careful selection of patients with sleeve or wedge pneumonectomy is mandatory.

Adult↗

PubMed2001

[Cerebral infarction presenting pure motor monoparesis: diagnosis by diffusion-weighted MR imaging].

We studied 10 patients with acute ischemic cerebrovascular disorders presenting paralysis confined to one limb, unaccompanied by sensory signs(pure motor monoparesis, PMM) on diffusion-weighted MR imaging(DWI). DWI revealed fresh ischemic lesions in all patients, except for 2 cases of transient ischemic attack. On DWI, acute infarction in multiple lesions was identified, and small superficial lesions were clearly described. Superficial lesions were seen in 4 patients, and deep lesions were also seen in 4 patients. DWI is useful for lesion analysis in cerebral infarction with PMM.

Aged↗