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Biomedical subjects

T Kodama

Publications and source records attributed to T Kodama.

At least 361 records · Page 20Linked to original sources
PubMed1997

A case of sarcomatoid carcinoma of the thymus.

A 57-year-old woman presented with a 10 x 10 cm anterior mediastinal mass. The tumor had invaded the pericardium, both lungs and the left brachiocephalic vein, and was treated by partial resection and postoperative radiation therapy. Pathological examination of the tumor revealed squamous cell carcinoma with a spindle cell sarcomatous component. Immunohistochemically, keratin and epithelial membrane antigen were positive in both the spindle cell sarcomatous areas and the squamous cell carcinomatous area and thus, a diagnosis of thymic carcinoma of sarcomatoid type was made. The patient died of recurrent disease 1 year after surgery. This case is the seventh reported in the English literature. Because of the poor outcome, adjuvant therapy is recommended.

Carcinoma, Squamous Cell↗
PubMed1997

Gene cluster for dissimilatory nitrite reductase (nir) from Pseudomonas aeruginosa: sequencing and identification of a locus for heme d1 biosynthesis.

The primary structure of an nir gene cluster necessary for production of active dissimilatory nitrite reductase was determined from Pseudomonas aeruginosa. Seven open reading frames, designated nirDLGHJEN, were identified downstream of the previously reported nirSMCF genes. From nirS through nirN, the stop codon of one gene and the start codon of the next gene were closely linked, suggesting that nirSMCFDLGHJEN are expressed from a promoter which regulates the transcription of nirSM. The amino acid sequences deduced from the nirDLGH genes were homologous to each other. A gene, designated nirJ, which encodes a protein of 387 amino acids, showed partial identity with each of the nirDLGH genes. The nirE gene encodes a protein of 279 amino acids homologous to S-adenosyl-L-methionine:uroporphyrinogen III methyltransferase from other bacterial strains. In addition, NirE shows 21.0% identity with NirF in the N-terminal 100-amino-acid residues. A gene, designated nirN, encodes a protein of 493 amino acids with a conserved binding motif for heme c (CXXCH) and a typical N-terminal signal sequence for membrane translocation. The derived NirN protein shows 23.9% identity with nitrite reductase (NirS). Insertional mutation and complementation analyses showed that all of the nirFDLGHJE genes were necessary for the biosynthesis of heme d1.

Amino Acid Sequence↗
PubMed1997

Determination of anti-streptolysin O antibody titer by a new passive agglutination method using sensitized toraysphere particles.

We developed a new method for determining the anti-streptolysin O (ASO) titer on the basis of a passive agglutination reaction. This new method uses Toraysphere particles sensitized with streptolysin O. This method was used to measure the ASO titer in 130 serum samples (from 31 patients with post-streptococcal glomerulonephritis, 26 patients with group A streptococcal pharyngitis, 5 patients with scarlet fever, 29 patients with non-group A streptococcal pharyngitis, 20 healthy children, and 19 healthy adults). The results were compared with those obtained simultaneously by two conventional methods, the Rantz-Randall and the NA-Latex-ASL methods. The results obtained by the Toraysphere method showed an excellent correlation with those obtained by each conventional method (correlation coefficients, 0.932 for the Rantz-Randall method and 0.913 for the NA-Latex-ASL method). The performance of each method was evaluated with respect to the clinical and microbiological diagnoses for each patient. The sensitivity, specificity, positive predictive value, and negative predictive value for the Toraysphere method were 76, 84, 81, and 79%, respectively. The corresponding values for the Rantz-Randall method were 48, 78, 67, and 62%, respectively, while those for the NA-Latex-ASL method were 60, 82, 76, and 69%, respectively. Because the Toraysphere method is simple and reproducible, has a short reaction time, and has a clear-cut endpoint for the analysis, we recommend it for routine use in determining the ASO titer in the clinical microbiology laboratory.

Adolescent↗
PubMed1997

Induction of various cytokines and development of severe mucosal inflammation by cagA gene positive Helicobacter pylori strains.

BACKGROUND: Helicobacter pylori strains possessing the cagA gene are thought to induce interleukin 8 (IL-8) in gastric mucosa. However, it is still unclear whether a relation exists between the cagA gene and the expression patterns of cytokines other than IL-8. AIMS: To investigate the relation between the cagA gene and the production of various cytokine proteins using an enzyme linked immunosorbent assay (ELISA). PATIENTS AND METHODS: In 184 patients, the cagA gene was detected by polymerase chain reaction (PCR), and levels of production of IL-1 beta, IL-6, IL-7, IL-8, IL-10, and tumour necrosis factor alpha (TNF-alpha) in antral biopsy specimens were measured by ELISA. RESULTS: Mucosal levels of IL-1 beta, IL-6, IL-8, and TNF-alpha were significantly higher in H pylori positive than in H pylori negative patients. Furthermore, the mucosal levels of IL-1 beta and IL-8 were significantly higher in specimens infected with cagA positive strains than in those infected with cagA negative strains. In H pylori positive patients, the mucosal level of IL-8 was closely correlated with that of IL-1 beta (p < 0.0001), and the mucosal level of IL-6 was closely correlated with that of TNF-alpha (p < 0.0001). CONCLUSION: These findings suggest that the ability to induce cytokines differs among the strains; cagA+ strains induce various kinds of cytokines and may cause severe inflammation, whereas cagA- strains induce IL-8 and IL-1 beta only weakly and may cause only mild inflammation. However, as most patients infected with the cagA+ strains have gastritis, these strains may not be equivalent to ulcerogenic strains.

Adult↗
PubMed1997

Endoscopic papillary balloon dilatation may preserve sphincter of Oddi function after common bile duct stone management: evaluation from the viewpoint of endoscopic manometry.

BACKGROUND: Endoscopic papillary balloon dilatation (EPBD) has been reported as a safe and effective alternative to endoscopic sphincterotomy in the management of common bile duct (CBD) stones; its effect on papillary function has yet to be elucidated. AIM: To investigate sphincter of Oddi (SO) motility before and after EPBD to determine its effect on SO function. PATIENTS AND METHODS: The papillary function of 10 patients with CBD stones was studied using endoscopic manometry before and one week after EPBD. The manometric studies were repeated one month after EPBD in seven patients. RESULTS: One week after EPBD, CBD pressure, SO peak pressure, SO basal pressure, and SO frequency decreased significantly. One month after EPBD, however, all parameters increased although the increases in SO basal pressure and CBD pressure were not significant. There was no significant difference in values of any parameter before and one month after EPBD. No serious complications occurred. CONCLUSION: These data suggest at least partial recovery of papillary function one month after the procedure. EPBD seems to preserve papillary function in treatment of CBD stones; a longer term follow up study with SO manometry should be performed to clarify the effect of EPBD on SO function.

Aged↗
PubMed1997

Gadolinium-enhanced MR imaging of thyroid and parathyroid masses.

PURPOSE: To evaluate spin-echo and contrast material-enhanced dynamic magnetic resonance (MR) imaging in characterization of thyroid and parathyroid masses. MATERIALS AND METHODS: Conventional T1- and T2-weighted, gadolinium-enhanced dynamic, and gadolinium-enhanced T1-weighted spin-echo imaging sequences were performed in 85 patients with thyroid and parathyroid tumors. Findings from spin-echo imaging and dynamic curve patterns from mean signal intensity ratios were evaluated for each histologic tumor type. RESULTS: T1- and T2-weighted imaging did not enable differentiation of benign from malignant tumors. Primary thyroid lymphoma enhanced less than other solid thyroid tumors, and parathyroid adenoma also enhanced less than other tumors (P < .05 compared with papillary carcinoma. CONCLUSION: Gadolinium-enhanced MR imaging cannot enable prediction of histologic type in thyroid and parathyroid tumors. However, in cases of multiple tumors, the technique may improve the contrast between the different histologic types and sometimes suggest the diagnosis of primary thyroid lymphoma or parathyroid adenoma.

Adenoma↗
PubMed1997

Increase of extracellular dopamine in primate prefrontal cortex during a working memory task.

Increase of extracellular dopamine in primate prefrontal cortex during a working memory task. J. Neurophysiol. 78: 2795-2798, 1997. The dopamine innervation of the prefrontal cortex is involved importantly in cognitive processes, such as tested in working memory tasks. However, there have been no studies directly investigating prefrontal dopamine levels in relation to cognitive processes. We measured frontal extracellular dopamine concentration using in vivo microdialysis in monkeys performing in a delayed alternation task as a typical working memory paradigm and in a sensory-guided control task. We observed a significant increase in dopamine level in the delayed alternation task as compared both with the sensory-guided control task and the basal resting level. The increase was seen in the dorsolateral prefrontal but not in the arcuate or orbitofrontal areas. The increase appeared to reflect the working memory component of the task and was observed mainly in the lip areas of principal sulcus. Although there was no significant difference in dopamine level between delayed alternation and sensory-guided control tasks in the premotor area, significant increases in dopamine concentration were observed during both tasks as compared with the basal resting level, indicating the importance of premotor dopamine for the motor response itself.

Animals↗
PubMed1997

Role of activin-A and follistatin in foam cell formation of THP-1 macrophages.

Macrophage (M phi) foam cell formation is a characteristic event that occurs in the early stage of atherosclerosis. To examine the roles of activin-A, a member of the transforming growth factor-beta superfamily, and follistatin, the binding protein for activin-A, in M phi function, we investigated their effects on foam cell formation of THP-1 M phi s. When THP-1 M phi s were treated with activin-A (5 nmol/L), foam cell formation and cellular cholesteryl ester accumulation were decreased. This downregulation was paralleled by a reduction in cell association and degradation of acetylated LDL. The inhibitory effect of activin-A on cell association and degradation was dose dependent, and the effect was blocked by concomitant addition of follistatin. Activin-A (5 nmol/L) also decreased the Bmax for acetylated LDL and scavenger receptor mRNA expression. Follistatin showed an effect opposite to that of activin-A and promoted M phi foam cell formation and cellular cholesteryl ester accumulation. It increased binding, cell association, and degradation of acetylated LDL and upregulated scavenger receptor mRNA expression. Because follistatin is the binding protein for activin-A, follistatin's effect is considered to be mediated by blocking the inhibitory effect of intrinsic activin-A. These results indicate that activin-A inhibits and follistatin promotes M phi foam cell formation by regulating scavenger receptor mRNA expression. We conclude that activin-A and follistatin play important roles in the process of atherosclerosis by regulating M phi foam cell formation.

Activins↗
PubMed1997

Dose-intensive weekly chemotherapy for treatment of relapsed small-cell lung cancer.

PURPOSE: This study was undertaken to determine the activity and toxicity of dose-intensive weekly chemotherapy (cisplatin, vincristine, doxorubicin, and etoposide [CODE] regimen) for previous treated, recurrent small-cell lung cancer (SCLC). PATIENTS AND METHODS: The 17 patients with relapsed SCLC entered onto the study were to receive intensive weekly chemotherapy with the CODE regimen. All 17 patients had been heavily pretreated with some form of cisplatin-based combination chemotherapy. Six patients had received previous chemotherapy with CODE and one patient with cisplatin and etoposide (PE) as induction therapy. Nine patients had been treated with concurrent or sequential PE plus thoracic irradiation (TRT). The median time off chemotherapy was 6.7 months (range, 3.3 to 72). Patients were treated with 9 weeks of the CODE regimen. Response, survival, and toxicity data were noted. RESULTS: All 17 patients were assessable for response, survival, and toxicity. Fifteen of 17 patients (88.2%) had an objective response, with five complete responses (CRs; 29%) and 10 partial responses (PRs; 58.8%). The median durations of response and survival were 156 days and 245 days, respectively. Myelosuppression was significant, with 76% of patients developing grade 4 leukopenia. No treatment-related death was observed. CONCLUSION: The CODE regimen is highly active in the treatment of relapsed SCLC with an encouraging survival outcome.

Aged↗
PubMed1997

Germ-line contribution of embryonic stem cells in chimeric mice: influence of karyotype and in vitro differentiation ability.

The effect of the karyotype and the ability to differentiate in vitro upon germ-line transmission by A3-1 embryonic stem (ES) cells in chimeric mice were examined. Germ-line transmission was confirmed in ES cells exhibiting 38% and more of the normal karyotype, but no chimeric mice and/or germ-line transmitters were observed regardless of the karyotype when the cystic embryoid body (CEB) was formed on day 8 and later in the suspension culture. Germ-line transmission of the ES cells was not significantly influenced by formation of the simple embryoid body (SEB). Germ-line transmitters were preferentially observed in chimeras when the ES cell contribution to coat color was markedly increased, but this contribution to coat color varied regardless of the karyotype or in vitro differentiation ability. These results suggest that A3-1 ES cells which exhibit CEB at 7 days after suspension culture and approximately 40% of normal karyotype are capable of germ-line transmission in chimeric mice.

Animals↗
PubMed1997

Expression of fibroblast growth factor 2 mRNA in early and advanced gastric cancer.

We examined the expression of FGF-2 mRNA in 16 early and 14 advanced gastric cancer by in situ hybridisation to elucidate its role in cancer progression. Anti-sense RNA probes were synthesized by transcribing the subcloned vector with T7 RNA polymerase in the presence of digoxigenin-labeled UTP. FGF-2 mRNA was located mainly in the cytoplasm around the nuclei of endothelial cells, fibroblasts and carcinoma cells. The expression was more frequently in the diffuse type carcinomas (4/7, 57%) than in the intestinal type tumours (5/23, 22%). The survival rates of advanced gastric cancers with FGF-2 mRNA expression were significantly lower than those without FGF-2 mRNA expression (p < 0.01). No significant correlation was seen with other clinicopathological factors. These results suggest that FGF-2 may play an important role for the growth of diffuse type gastric cancers, particularly at their advanced stage.

Aged↗
PubMed1997

The multiple roles of macrophage scavenger receptors (MSR) in vivo: resistance to atherosclerosis and susceptibility to infection in MSR knockout mice.

Both type I and type II MSRs are integral membrane proteins containing a collagenous domain and elicit an extraordinarily wide range of ligand binding capability. They were found during the search for the molecule(s) responsible for the accumulation of modified LDL during atherogenesis. However, all prior the evidence relating to their physiological and pathophysiological roles in vivo had been indirect. Targeted disruption of the MSR gene results in a reduction in the size of atherosclerotic lesions in an apo E deficient animal. Macrophages from MSR deficient mice exhibit a marked decrease in modified LDL uptake in vitro, whereas modified LDL clearance from plasma remains normal, suggesting that there are alternative mechanisms for the uptake of modified LDL from the circulation. In addition, MSR knockout mice are more susceptible to L. monocytogenes and HSV-1 infection, indicating a role for MSR in host defense against various pathogens.

Animals↗
PubMed1997

[A case of systemic arterial supply to the normal left basal segments with no symptoms].

A 41-year-old man was admitted to Hirakata City Hospital because of an abnormal shadow on chest X-ray film. Chest X-ray film showed a tumorous shadow in the left anterior basal segment (S8). MRI showed aberrant arteries arose from the descending aorta clearly. Broncho-fibers-copy showed no defect of visible bronchi. Aortography showed one aberrant arteries arose from the descending thoracic aorta, circulated in the basal segment of the left lower lobe, and returned to the left pulmonary vein. Pulmonary arteriogram revealed defect of A8-10. Resection of left lower lobe was performed. In the resected specimen, the bronchi of the left lower lobe had a normal structure and showed a normal pattern of distribution.

Adult↗
PubMed1997

[Usefulness of rCBF SPECT in patients with encephalitis: comparison study with MRI].

Twenty-nine rCBF SPECT study was done in 17 patients with encephalitis. Five of 6 patients (83.3%) showed regional high uptake in acute phase within a week after onset and 16 of 23 studies (69.6%) showed regional low uptake in subacute and chronic phase. Six of 19 lesions (31.6%) with regional high uptake changed to low uptake and 11 lesions (57.9%) improved to normal uptake on follow up studies. Seventeen of 51 lesions with low uptake (33.3%) improved to normal uptake. On the comparative study with MRI, 8 of 18 (44.4%) high uptake area showed cortical thickness or high intensity on T2 weighted images. Thirty-six of 74 low uptake area (48.6%) showed cortical thickness, brain atrophy or high intensity on T2 weighted images. Forty-eight of 212 regions (22.6%) with normal MRI findings showed abnormal accumulation of cerebral tracer on rCBF SPECT studies. rCBF SPECT was useful tool for diagnosis and follow up management in patients with encephalitis.

Adolescent↗
PubMed1997

Cine magnetic resonance imaging, computed tomography and ultrasonography in the evaluation of chest wall invasion of lung cancer.

PURPOSE: To assess the usefulness of cine-magnetic resonance imaging (cine-MRI)in the evaluation of chest wall invasion, we compared the results of cine-MRI with those of computed tomography (CT) and ultrasonography (US). MATERIALS AND METHODS: Eleven patients were examined who had no pain and who were difficult to diagnose by routine examinations. MRI was performed with a Magnetom SP/4000, 1.5T unit (Siemens, Germany). For cine imaging, continuous turbo-FLUSH (ultra fast low angle shot) images were obtained at an orthogonal section to the chest wall during slow deep breathing. A CT scan was performed using a TCT 900S or Super Helix (Toshiba, Japan) at 1 cm intervals, with section thicknesses of 1 cm throughout the entire chest. US was performed with a model SSA-270A (Toshiba, Japan) with 7.5-MHz linear array scanners (PLF-705S; Toshiba, Japan). RESULTS: Sensitivity, specificity and accuracy were 67%, 75% and 73% for cine MRI, 67%, 63% and 64% for CT, 33%, 75% and 64% for US, respectively. CONCLUSIONS: These results indicate that cine MRI is potentially useful for the diagnosis of chest wall invasion of lung cancer.

Evaluation Studies as Topic↗
PubMed1997

Novel elements located at -504 to -399 bp of the promoter region regulated the expression of the human macrophage scavenger receptor gene in murine macrophages.

The expressions of type I and type II macrophage scavenger receptors (MSRs) are highly specific in macrophages and related cell types. Although some reports have described the regulation of MSR gene expression and proposed some cis-elements related to cell-specific expression, the regulation of MSR remains largely unclear. This is due, in part, to an unacceptably low efficiency of transfection into monocyte/ macrophage cells. In the present study, we optimized the conditions of electroporation in murine macrophage (P388D1) cells. The efficiency of electroporation was increased 20-fold compared with previous methods. Using the optimized method, we focused on studying the regulation of the human MSR promoter in macrophages. We presently demonstrate that: a) the proximal -10 to +50 bp human MSR promoter region is necessary for the cell type-specific expression of human MSR; b) the 6.5 kbp upstream sequence suppresses the expression of human MSR; c) a promoter region extending from -504 to -399 bp produced the greatest increase in transcriptional activity; d) macrophage cell-specific transcription factors bind to the region as determined by electrophoretic mobility shift assay (EMSA) and a footprint assay; and e) mutations of the region reduced about 40-75% of the promoter activity in a transfecting assay. We concluded that novel elements located at the -504 to -399 bp region may play an important role in the regulation of the MSR gene expression in macrophages. We speculate that macrophage-specific factors binding to those elements may be responsible for the transcription regulation of the MSR gene in macrophages.

Animals↗
PubMed1997

[A case of mobile left atrial thrombus without mitral valve disease].

A 70-year-old woman who had a left atrial thrombus without mitral valve disease was reported. On admission her electrocardiogram showed atrial fibrillation, but there was no cardiac murmur. Transthoracic echocardiogram revealed a dilated left atrium and an intact mitral valve, but did not detect any thrombus. Transesophageal echocardiogram, however, demonstrated the thrombus attaching to the left atrial appendage. Removal of the thrombus and maze procedure were performed at the same time. Although a pacemaker (DDDR mode) was required postoperatively, she spends uneventful daily life at two years after the surgery.

Aged↗