Biomedical subjects

M Oda

Publications and source records attributed to M Oda.

At least 73 records · Page 4Linked to original sources

PubMed2001

Nodal occult metastasis in patients with peripheral lung adenocarcinoma of 2.0 cm or less in diameter.

BACKGROUND: Detection of occult micrometastasis in regional lymph nodes is crucial for diagnosis and selection of appropriate therapy for patients with pN0 non-small-cell lung carcinoma. Using immunohistochemical staining, we evaluated the impact of detection of occult micrometastasis on the prevalence and prognosis of patients with lung adenocarcinoma of 2.0 cm or less in diameter. METHODS: A total of 103 pN0 disease patients with peripheral lung adenocarcinomas of 2.0 cm or less in diameter were enrolled in this study. We studied 1,438 regional lymph nodes for occult micrometastasis by immunohistochemical staining for cytokeratins. RESULTS: Micrometastasis was detected in 49 lymph nodes (3.4%) of 21 patients (20.4%) but not in patients with localized bronchioloalveolar carcinoma or localized bronchioloalveolar carcinoma with foci of collapse of alveolar structure. The 5-year survival rate (61.9%) of patients with micrometastasis was significantly (p = 0.0041) lower than that of patients without micrometastasis (86.3%). CONCLUSIONS: There still remains a risk of nodal micrometastasis in patients with primary peripheral lung adenocarcinoma, even if the diameter of the tumor is smaller than 2.0 cm. Selection of patients for limited surgery should be done prudently, taking into consideration the risk of nodal micrometastasis.

Adenocarcinoma↗

PubMed2001

Insulin mimetic effect of a tungstate cluster. Effect of oral administration of homo-polyoxotungstates and vanadium-substituted polyoxotungstates on blood glucose level of STZ mice.

Aqueous vanadate and aqueous tungstate have been known to mimic all or most of the actions of insulin in intact cell systems with respect to normalization of the blood glucose level. By carrying out oral administration in vivo experiments on the blood glucose level of streptozotocin (STZ)-induced diabetes (STZ mice), the insulin-mimetic (IM) effects of metal-oxide clusters of all-inorganic composition were examined using many types of polyoxometalates (POM) with and without vanadium substitution. Several homo-POM and vanadium-substituted POM showed hypoglycemic effects. The observed hypoglycemic effects indicated that POM with the Dawson structure [[alpha-P(2)W(18)O(62)](6-) (W-2), [alpha-P(2)W(17)V(V)O(62)](7-) (V-19) and [alpha-1,2,3-P(2)W(15)V(V)(3)O(62)](9-) (V-04)] are more effective than those with the Keggin structure [[alpha-PW(12)O(40)](3-) (W-1), [alpha-PW(11)V(V)O(40)](4-) (V-01), [alpha-1,2-PW(10)V(V)(2)O(40)](5-) (V-02), [alpha-1,2,3-PW(9)V(V)(3)O(40)](6-) (V-03) and [alpha-1,4,9-PW(9)V(V)(3)O(40)](6-) (V-13)]. The vanadate cluster [V(10)O(28)](6-) (V-15) also showed a hypoglycemic effect. (31)P and (51)V NMR measurements showed that the Dawson POM (W-2, V-04 and V-19) are stable in aqueous solution under the conditions used. The effect of all POM on the body weight of STZ mice was also examined. The decrease in body weight after administration of W-2 was much less than for V-19, V-04 and V-15. This suggests that not only monomeric tungstate and vanadate, but also the structure factors of tungstate and vanadate clusters, can play a significant role in their biological action.

Administration, Oral↗

PubMed2001

Variation of temporal characteristics in human cerebral hemodynamic responses to electric median nerve stimulation: a near-infrared spectroscopic study.

Using near-infrared spectroscopy, we studied cerebral hemodynamic responses to electric median nerve stimulation in ten subjects. The recordings were conducted by optical fibers placed over the left scalp. Electric stimuli were delivered to contra- and ipsilateral median nerves, respectively. Hemodynamic responses in the secondary somatosensory cortex were observed following each median nerve stimulation, except for three drowsy subjects. The contralateral stimulation tended to induce a larger response. The degree of change in oxygenated hemoglobin was hardly related to stimulus intensities, and was augmented by attention. Four subjects showed long-lasting responses throughout the stimulus periods, while three other subjects revealed transient responses. Thus, taking account of the temporal activation patterns is necessary for proper interpretation of the hemodynamic response following electric nerve stimulation.

Adult↗

PubMed2001

Inhibitors from rhubarb on lipopolysaccharide-induced nitric oxide production in macrophages: structural requirements of stilbenes for the activity.

By bioassay-guided separation, three stilbenes (rhapontigenin, piceatannol, and resveratrol), two stilbene glucoside gallates (rhaponticin 2"-O-gallate and rhaponticin 6"-O-gallate), and a naphthalene glucoside (torachrysone 8-O-beta-D-glucopyranoside) with inhibitory activity against nitric oxide (NO) production in lipopolysaccharide-activated macrophages were isolated (IC(50)=11--69 microM). The oxygen functions (-OH, -OCH(3)) of stilbenes at the benzene ring were essential for the activity. The glucoside moiety reduced the activity, while the alpha,beta-double bond had no effect. Furthermore, the active stilbenes (rhapontigenin, piceatannol, and resveratrol) did not inhibit inducible NO synthase activity, but they inhibited nuclear factor-kappa B activation following expression of inducible NO synthase.

Lipopolysaccharides↗

PubMed2001

Should mediastinal nodal dissection be routinely undertaken in patients with peripheral small-sized (2 cm or less) lung cancer? Retrospective analysis of 225 patients.

OBJECTIVE: We retrospectively reviewed nodal status of the patients with peripheral small-sized lung cancer grouped by cell type and tumor size to evaluate the necessity of systematic nodal dissection in this group of patients. METHODS: From 1973 to 1998, 1713 patients underwent pulmonary resection for primary lung cancer in Kanazawa University. Among them, 225 patients (13.1%) with peripheral small-sized (2 cm or less) lung cancer underwent lobectomy and systematic nodal dissection were retrospectively reviewed. The maximum diameter of the tumor was measured on formalin-fixed surgical specimens. RESULTS: The histological types were adenocarcinoma in 170 (75.6%), squamous cell carcinoma in 20 (8.9%), small cell carcinoma in 19 (8.4%) and others in 16 (7.1%). Among 170 adenocarcinoma patients, 38 (22.4%) showed hilar or mediastinal lymph node metastases. No mediastinal lymph node metastasis was encountered in all squamous cell carcinoma (n = 20), adenocarcinoma < or = 1 cm (n = 16), small cell carcinoma < or = 1 cm (n = 4), and adenocarcinoma of Noguchi's classification type A or B (n = 24). CONCLUSIONS: Mediastinal nodal dissection would be unnecessary in the patients with peripheral small-sized lung cancer fulfilling these criteria: (1) squamous cell carcinoma < or = 2 cm; (2) adenocarcinoma < or = 1 cm; (3) localized bronchioloalveolar carcinoma < or = 2 cm without foci of active fibroblastic proliferation in histology (Noguchi's classification type A or B adenocarcinoma); (4) small cell carcinoma < or = 1 cm. Candidates fulfilling above criteria were 28.4% (64/225) of small-sized lung cancer and 10.9% of stage IA patients. The establishment of a universally accepted therapeutic strategy for small-sized lung cancer is indispensable in the clinical spread of various sort of limited resections.

Adenocarcinoma↗

PubMed2001

Enhanced expression of endothelin receptor subtypes in cirrhotic rat liver.

BACKGROUND/AIMS: A number of vasoactive substances have been implicated as potential mediators of intrahepatic portal hypertension. Endothelin (ET)-1 has been suggested to be involved in the regulation of hepatic microcirculation and development of portal hypertension. The aim of this study was to clarify the localization of two subtypes of ET receptors, ET A (ETAR) and B receptors (ETBR), in normal rat liver, and how the receptor expressions are altered in CCl4-induced cirrhotic rat liver. METHODS: Liver specimens were examined immunohistochemically after reacting with anti-ETAR and anti-ETBR rabbit polyclonal antibodies. Immunogold staining was also performed using the same antibodies, and examined under light and electron microscopy. RESULTS: In normal rat liver, immunohistochemistry revealed expression of ETAR and ETBR on the hepatic sinusoidal lining cells. By immunogold electron microscopy, electron-dense gold particles indicating the presence of ETARs were localized mainly on hepatic stellate cells (HSCs) and to a lesser extent on sinusoidal endothelial cells (SECs), while ETBRs were expressed equally intensely on HSCs and SECs. In cirrhotic animals, both ETAR and ETBR increased significantly on HSCs, while there were no significant increases in either receptor on SECs. CONCLUSIONS: In the normal state, HSCs possess both ETARs and ETBRs, while SECs mainly possess ETBRs. In cirrhosis, endothelins may exert more intense effects on HSCs via the enhanced ETARs and ETBRs, causing an increase in hepatic sinusoidal microvascular tone.

Animals↗

PubMed2001

Endothelial nitric oxide synthase and caveolin-1 are co-localized in sinusoidal endothelial fenestrae.

BACKGROUND/AIMS: Nitric oxide is synthesized in diverse mammalian tissues by a family of calmodulin-dependent nitric oxide synthases (NOS). Caveolin, the principal structural protein in caveolae, interacts with endothelial NOS leading to enzyme inhibition in a reversible process modulated by Ca++-calmodulin. The aim of the present study was to clarify the ultrastructural localization of eNOS and caveolin-1 in hepatic sinusoidal endothelium by an electron immunogold method. METHODS: Male Wistar rats were used. Liver tissues and hepatic sinusoidal endothelial cells isolated from rat livers by collagenase infusion were studied. For immunohistochemistry, liver specimens were reacted with anti-eNOS or anti-caveolin-1 antibody. The ultrastructural localization of eNOS or caveolin-1 was identified by electron microscopy using an immunogold post-embedding method. RESULTS: Immunohistochemical studies using liver tissues localized endothelial NOS in hepatic sinusoidal lining cells, portal veins and hepatic arteries; and caveolin-1 in sinusoidal lining cells, bile canaliculi, portal vein and hepatic arteries. Immunogold particles indicating the presence of eNOS and caveolin-1 were demonstrated on the plasma membrane of sinusoidal endothelial fenestrae in liver tissue and also in isolated sinusoidal endothelial cells. CONCLUSION: Endothelial NOS and caveolin are co-localized on sinusoidal endothelial fenestrae, suggesting that interaction of the two may modulate cellular regulation of NO synthesis.

Animals↗

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↗