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Biomedical subjects

K Shimada

Publications and source records attributed to K Shimada.

At least 757 records · Page 42Linked to original sources
PubMed1995

[A case of multiple myeloma complicated by acute transverse myelopathy due to epidural abscess].

A 51-year-old man developed fever and lumbago followed by rapidly progressive bilateral sensory disturbance below the 9th thoracic spinal cord level, flaccid paraplegia, urinary obstruction and constipation. Based on radiological examinations and laboratory findings, a diagnosis of transverse myelopathy due to epidural abscess was made. A series of MRI studies revealed multiple abscess formation in the paravertebral muscles. Hypergammaglobulinemia with M protein was observed continuously, and further examination revealed multiple myeloma in the early stage. Since it has been reported that several different immunosuppressive mechanisms precede the development of bone lesions in multiple myeloma, these mechanisms may have played an important role in the rapid progression of the abscess in this patient. Multiple myeloma is not only important as one of the disorders underlying epidural abscess of unknown etiology, but important in predisposing to severe infection as a result of the immunosuppressive mechanisms present starting in the early stage of the disease.

Abscess↗
PubMed1995

Effect of the angiotensinogen gene Met235-->Thr variant on blood pressure and other cardiovascular risk factors in two Japanese populations.

OBJECTIVE: To investigate the gene frequency of the T235 allele and its relationship with hypertension in two Japanese populations. METHODS: T235 was investigated by restriction fragment length polymorphism using the polymerase chain reaction technique in 213 Japanese males aged 40-59 years, who were randomly selected from participants in the Jichi Medical School Cohort Study (Awaji-Hokudan population, n = 157; Niigata-Yamato population, n = 56). RESULTS: The gene frequency of the T235 allele in the two populations was very similar (Awaji-Hokudan 0.65, Niigata-Yamato 0.62; mean 0.64). The T235 frequency was 0.60 in normotensive males, approximately 1.2- to 1.7-fold that in Caucasians. Hypertension, in particular that associated with a positive family history of hypertension, was more common in individuals homozygous for the T235 allele. The levels of total cholesterol, blood glucose and fibrinogen showed a weak and non-significant relationship with the angiotensinogen genotype. CONCLUSION: The T235 angiotensinogen allele was more common in Japanese than in Caucasians, and was a predisposing factor for hypertension.

Adult↗
PubMed1995

[Successful chemotherapy and concurrent radiotherapy for metastatic lung. mediastinal malignant fibrous histiocytoma].

We treated a patient for malignant fibrous histiocytoma (MFH) which metastasized to mediastine and lung from left femur. The patient was a sixty-three year old man. He had his left femur, the primary lesion, resected. After the first operation, we found metastasis to his lung and mediastine and we performed twice thoracotomy. Then he was found to have the third metastasis which we decided was inoperable, this time we tried chemotherapy and concurrent radiotherapy. CDDDP and ACR with radiotherapy showed significant effect. The patient died after eight months at last because of fistula between the descending aorta and the ileum, and as we performed an autopsy on him, his MFH proved pathological CR.

Antineoplastic Agents↗
PubMed1995

Effects of endogenous endothelial interleukin-8 on neutrophil migration across an endothelial monolayer.

OBJECTIVE: Recent studies suggest that interleukin-8 (IL-8) is involved in the neutrophil infiltration of subendothelial myocardial tissue in the ischaemia/reperfusion injury associated with acute myocardial infarction. The aim of this study was to investigate the effects of IL-8 on transendothelial neutrophil migration using an in vitro three dimensional double chamber migration assay system. METHODS: Human neutrophils were incubated with human endothelial cell monolayers for 1 h, and adherent and migrated neutrophils were then counted. Expression of IL-8 mRNA and secretion of its protein by endothelial cells were analysed respectively by northern blotting and ELISA. RESULTS: Recombinant human (rh) IL-8 (50 ng.ml-1) placed in the lower compartment significantly increased neutrophil adhesion 1.7-fold and transmigration 2.3-fold, compared with control conditions using medium alone in both compartments. In contrast, rh IL-8 (50 ng.ml-1) in the upper compartment significantly inhibited neutrophil adhesion and transmigration by 53% and 61% respectively compared with controls. Neutrophil adhesion and transmigration was dependent on the IL-8 concentration gradient between upper and lower compartments. Unstimulated endothelial cells showed no IL-8 expression, but endothelial cells pretreated with IL-1 beta (25 U.ml-1) markedly induced endogenous IL-8 mRNA and protein accumulation. When endothelial cells were cocultured with neutrophils, enhanced endogenous IL-8 production was observed. Pretreatment of endothelial cells with IL-1 beta for 4 and 24 h increased neutrophil transmigration 2.8-fold and 3.0-fold respectively, compared with unstimulated endothelial cells. The addition of anti-IL-8 monoclonal antibody (12.5 micrograms.ml-1) to the upper compartment with IL-1 beta-pretreated endothelial cells further enhanced transmigration from 2.8- to 3.3-fold and from 3.0- to 4.3-fold respectively. CONCLUSIONS: Endogenous endothelial IL-8, secreted from activated endothelial cells into the apical side of endothelial cell monolayers, has an inhibitory effect on transendothelial migration of neutrophils, suggesting that IL-8 may prevent excessive neutrophil infiltration of myocardial tissue from circulating blood in the reperfusion injury associated with acute myocardial infarction.

Blotting, Northern↗
PubMed1995

[Coronary artery bypass grafting in a patient with a single coronary artery].

Coronary artery bypass grafting in a patient with a single coronary artery is reported. A 61-year-old male who had chest pain and palpitation was transferred to our hospital. His ECG showed ischemic change, and CPK rose to a high level. Emergency coronary angiography revealed a type L II A (Lipton's criteria) single coronary artery and atherosclerotic stenosis on three major branches. He underwent CABG of LAD using LITA, #3 and #14 using saphenous vein grafts. Post operative angiography confirmed patent grafts, and the patient was free from symptoms.

Coronary Angiography↗
PubMed1995

[A case of leiomyosarcoma as a mediastinal tumor excised by bilateral thoracotomy].

Leiomyosarcoma as a mediastinal tumor is so rare that no more than 6 and 12 cases have so far been reported in and out Japan, respectively. The patient was 74-year-old male. While treated at the outpatient clinic of our university hospital for low back pain, he was referred to our department because of a shadow of the mediastinum on chest roentgenogram. A fist-sized tumor was found located in the posterior mediastinum behind the heart. Since it was difficult to make a preoperative definitive diagnosis, it was excised by bilateral thoracotomy. Histologically, it was compatible with sarcoma and a definitive diagnosis of leiomyosarcoma was made based on electron microscopic findings.

Aged↗
PubMed1995

[Right-sided infectious endocarditis due to methicillin-resistant Staphylococcus aureus resulting in ruptured abscess of the ventricular septum and sinus of Valsalva].

A 24-year-old woman presented with right-sided infectious endocarditis due to methicillin-resistant Staphylococcus aureus (MRSA). This is the first report of right-sided infectious endocarditis caused by MRSA in Japan. The patient was admitted to the Jichi Medical School Hospital because of fever of unknown origin and disturbance of consciousness. Several months before, she had discontinued treatment for hyperthyroidism. Antibiotics effective against MRSA, vancomycin and flomoxef, were given intravenously, but a new heart murmur was detected. Echocardiographic study revealed vegetations attached to the tricuspid valve and abscess formation on the ventricular septum. The vancomycin dosage was increased and arbekacin sulfate was also given from the sixth hospital day. However, these antibiotics had very little effect and the abscess rapidly increased in size. Color flow mapping finally demonstrated intracardiac shunt flow through the ruptured abscess of the ventricular septum and sinus of Valsalva. She died suddenly, probably from heart failure. The prognosis of infectious endocarditis due to MRSA is poor and drug therapy often fails. Thus, surgery should be considered in the early stage.

Abscess↗
PubMed1995

[Lymphatics of the thoracic surface of the diaphragm especially located around the inferior surface of the pericardial sac].

The lymphatics on the thoracic surface of the diaphragm, especially lying around the lateral and posterior sides of the base of the cardiac sac, were examined in 68 adult Japanese cadavers macroscopically (37 males and 24 females, aged 45-92 years, no clinical evidences of neoplasms). In this observation, a vein which drained into the terminal portion of the inferior vena cava was observed. The lymph nodes in this region were located along the vein frequently (80.9%). The vein passed through the esophageal hiatus, or penetrated the diaphragm and finally communicated with veins around the esophagogastric junction. However, lymphatic vessels were not observed passing through the phrenico-esophageal membrane and/or the diaphragm. The collecting vessels, which originated from the lymphatics, drained into the esophageal lymphatics, and it drained into the thoracic duct via the esophageal lymphatics. In pleural effusion cases, lymphatic nets were clearly observed on the thoracic surface of the diaphragm immediately under the parietal pleura. The lymphatic nets did not communicate with the diaphragmatic lymphatics around the base of the cardiac sac. Moreover, large collecting vessel from the lymphatic nets passed through the muscular crus of the diaphragm near the medial arcuate ligament and traveled inferior to merge at the original portion of the thoracic duct at the level of the renal vessels. From these observations, the lymphatics on the posterior part of the thoracic surface of the diaphragm communicated with several regional lymphatics independently. This morphological lymphatic traveling suggests that the route differs in cases of pleural effusion or cancer metastasis.

Aged↗
PubMed1995

[Relationship between static images of 13N ammonia positron emission tomography and left ventricular wall motion in patients with coronary artery disease].

Observed myocardial activities in static image of 13N ammonia positron emission tomography (PET) contains factors about not only myocardial blood flow but also wall motion, wall thickness and glutamine synthetase activity. Those factors may help to delineate myocardial viability in 13N ammonia static image. To assess the role of 13N ammonia static image in prediction of reversibility of regional wall motion abnormalities after revascularization, we studied 20 patients with coronary artery disease. Of these patients, 15 patients underwent successful coronary revascularization (8 PTCA, 7 CABG). Regional 13N concentration before revascularization was expressed as a percent of maximal myocardial concentration and compared with regional wall motion. Wall motion was assessed by visual analysis using left ventriculography. Regional myocardial 13N concentration in normal, hypokinetic, akinetic and dyskinetic segments was 85 +/- 9.3%, 75 +/- 11%*, 71 +/- 17%* and 58 +/- 7.7%*#+, respectively (*p < 0.05 vs. normal, #p < 0.05 vs. hypokinesis, +p < 0.05 vs. akinesis). The segments with functional improvement showed significantly higher concentration of 13N than those without functional recovery (80 +/- 9.7% vs. 67 +/- 8.3%, p < 0.05). By using an optimized threshold value for normalized 13N activities, the sensitivity and specificity reached to 67% and 100%, respectively, to predict functional recovery. Our data suggested that myocardial 13N concentration in static PET image is closely related to the left ventricular wall motion in the patients with coronary artery disease and that it has a possible value of prediction of myocardial viability.

Ammonia↗
PubMed1995

Effects of inflammatory cytokines on vascular tone.

OBJECTIVE: To assess the direct effects of the inflammatory cytokines interleukin-2 (IL-2), interleukin-6 (IL-6) and interleukin-8 (IL-8) on vascular smooth muscle contraction. METHODS: Smooth muscle contractility was studied in the thoracic aorta isolated from male Sprague-Dawley rats. Syntheses of cAMP and nitric oxide (NO) were investigated in cultured rat vascular smooth muscle cells (VSMC). RESULTS: Pretreatment of the rings with IL-6 (10 ng/ml) for 180 min caused a significant inhibition of their contraction in response to 10(-5) M phenylephrine, wile Il-2 (10 ng/ml) and IL-8 (100 ng/ml) showed no significant effect on the contraction. The inhibitory effect of IL-6 exhibited a dose-dependency (0.1 approximately 10 ng/ml). In cultured rat VSMC, synthesis of cAMP was increased time-dependently by IL-6, while IL-2 and IL-8 failed to show any significant effects. IL-2, IL-6 and IL-8 did not affect the production of nitrite, a stable metabolite of NO, by VSMC. CONCLUSIONS: IL-6, but not IL-2 and IL-8, is a potent inhibitor of vascular contraction, which effect is mediated through the increased cAMP synthesis.

Animals↗
PubMed1994

Thyroid hormone metabolism in a transthyretin-null mouse strain.

Transthyretin (TTR) is the principal carrier of thyroid hormones in rodent plasma and the major protein synthesized by the choroid plexus. Mice lacking TTR generated by targeted disruption (Episkopou, V., Maeda, S., Nishiguchi, S., Shimada, K., Gaitanaris, G. A., Gottesman, M. E., and Robertson, E. J. (1993) Proc. Natl. Acad. Sci. U.S.A. 90, 2375-2379) had a 50% decrease in total thyroxine (T4) plasma levels but had normal free hormone levels as compared to wild-type mice. In the mutant serum there was increased T4 binding to thyroxine-binding globulin. Thyroxine-binding globulin mRNA levels were the same in mutant and wild-type animals. Wild-type serum depleted of TTR also presented increased T4 binding to thyroxine-binding globulin, suggesting that TTR competes with thyroxine-binding globulin for T4 binding. Total and free triiodothyronine and thyrotoropin-stimulating hormone levels were not affected by the absence of TTR. Liver deiodinase-I activity, mRNA levels, and brain deiodinase-II activity were normal in the mutant mice, suggesting that the absence of TTR does not affect tissue thyroid hormone content. The low T4 levels found in the mutant mice sera cannot be accounted for by increased glucuronidation because the liver activity of UDP-glucuronosyltransferase was not affected in the TTR-deficient mice. We concluded that transthyretin-deficient mice are euthyroid in the absence of the major plasma T4 carrier. We ascribed this to the normal free hormone levels in the serum of the mutant mice. Our data, therefore, strongly supported the free hormone hypothesis for thyroxine uptake (Mendel, C. M. (1989) Endocr. Rev. 10, 232-274).

Animals↗
PubMed1994

Mechanism of inhibition of HIV-1 infection in vitro by guanine-rich oligonucleotides modified at the 5' terminal by dimethoxytrityl residue.

Oligodeoxyribonucleotides (ODN) linked at their 5'-end with dimethoxytrityl (DmTr) residue were examined for antiviral activities against human immunodeficiency virus type 1 (HIV-1). We found that guanine-rich oligonucleotides exhibit anti-HIV activity upon 5'-end modification with DmTr. One oligonucleotide, DmTr-TGGGAGGTGGGTCTG (SA-1042), showed potent anti-HIV activity in vitro. A greater than 95% reduction of infectivity was observed if the cells were treated with 10 micrograms/ml of SA-1042 at the time of viral infection, PCR analysis confirmed that there was a significant reduction of provirus in the cells exposed to virus in the presence of SA-1042. By contrast, no inhibition was observed if the cells were treated with the oligomer 1 h after virus adsorption. SA-1042 prevented syncytium formation between chronically infected cells and CD4 positive uninfected cells. Furthermore, the oligomer interfered the interaction of purified gp120 to the CD4 receptor. By contrast, SA-1042 had no inhibitory effect on chronically HIV-infected cells. These results strongly suggest that the DMTr-ODNs with appropriate base sequences antagonize HIV-1 infection during the stage of virus-cell interaction.

Antiviral Agents↗