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Biomedical subjects

R Murakami

Publications and source records attributed to R Murakami.

At least 19 recordsLinked to original sources
PubMed1997

MR evaluation of radiation otomastoiditis.

PURPOSE: The purpose of this study was to evaluate the incidence of radiation otomastoiditis, on using T2-weighted magnetic resonance (MR) imaging, in relation to radiation fields, doses, intervals, and clinical symptoms after radiotherapy that included the temporal bone in the fields. METHODS AND MATERIALS: We performed follow-up MR examinations at various intervals after radiotherapy including the temporal bones for 270 ears of 114 patients with various diseases of the head and neck and intracranial regions. The middle ear and mastoid air cells on T2-weighted images were scored as follows; showing no high signal intensity, a local high signal intensity area, or a high signal intensity area occupying the entire middle ear and all mastoid air cells. The radiation fields as depicted on the lateral simulator films classed as anterior to the clival line, posterior to the clival line, or both. RESULTS: The incidence of radiation otomastoiditis depicted on T2-weighted MR images increased in the patients who had received irradiation doses of 50 Gy or more. In the patients with doses of less than 50 Gy, the incidence was 18% within 6 months following radiotherapy, 13% at between 6 and 12 months, and 8% after 12 months, whereas it was more than 50% at any period after radiotherapy in the patients with 50 Gy or more. The incidence of radiation otomastoiditis was quite high in the patients whose radiation fields included region both anterior and posterior to the clival line. CONCLUSION: The incidence of radiation otomastoiditis as demonstrated on T2-weighted MR images is increased at irradiation doses of 50 Gy or more. To reduce the incidence of severe radiation otomastoiditis, the irradiation fields of the temporal bone when the dose is 50 Gy or more should be limited to as small as possible. The clival line is considered to be a good landmark in reducing the irradiation field when doses of 60-70 Gy are delivered in curative radiotherapy.

Adolescent↗
PubMed1997

Relationship between progressive microvascular damage and intramyocardial hemorrhage in patients with reperfused anterior myocardial infarction: myocardial contrast echocardiographic study.

BACKGROUND: Recent studies indicated that ischemic microvascular damage may be reversible or progressive after coronary reflow. Intramyocardial hemorrhage is a phenomenon that reflects severe microvascular injury. We examined the relationship between temporal changes in microvascular perfusion patterns detected by myocardial contrast echocardiography (MCE) and intramyocardial hemorrhage detected by magnetic resonance imaging (MRI) in patients with acute myocardial infarction (AMI). METHODS AND RESULTS: The study population consisted of 24 patients with anterior AMI. All patients underwent MCE shortly after reflow and in the chronic stage (a mean of 31 days after reflow). Wall motion score (WMS) was determined as the sum of 16 segmental scores (dyskinetic/akinetic=3 to normal=0) at days 1 and 31. Gradient-echo acquisition and gadolinium-DTPA-enhanced spin-echo MRI were performed within 10 days after reflow. In MCE shortly after reflow, 16 patients (67%) showed contrast enhancement and the other 8 patients (33%) showed a sizable contrast defect. In the chronic stage, a persistent contrast defect was observed in 7 of 8 patients with a contrast defect shortly after reflow. Consistent contrast enhancement was observed in 12 of 16 patients (75%) with contrast enhancement shortly after reflow, indicating that a contrast defect newly appeared in 4 patients (25%). Intramyocardial hemorrhage was detected in 9 patients (38%): 5 of 7 patients with a persistent contrast defect and in all 4 patients with a new appearance of a contrast defect during the chronic stage. The patients without hemorrhage showed a significant improvement in WMS compared with patients with hemorrhage at day 31 (5+/-5 versus 19+/-6, P<.0005). CONCLUSIONS: These results suggest that irreversible microvascular damage to the ischemic myocardium may cause intramyocardial hemorrhage after reflow, associated with impaired recovery of left ventricular function. Contrast enhancement within the risk area shortly after reflow does not necessarily indicate long-term microvascular salvage.

Aged↗
PubMed1997

Role of dynamic MRI in the evaluation of head and neck cancers treated with radiation therapy.

PURPOSE: To study the usefulness of dynamic magnetic resonance imaging in the evaluation of head and neck cancers treated with radiation therapy. METHODS AND MATERIALS: Seventy-six patients (58 males and 18 females; ages 20-82) with head and neck cancers (10 nasopharyngeal carcinomas, 22 mesopharyngeal carcinomas, 10 hypopharyngeal carcinomas, 16 oral cavity carcinomas, 11 lingual carcinomas, and 7 laryngeal carcinomas) were treated by radiation therapy combined with concomitant low-dose cisplatinum. Magnetic resonance imaging (MRI) was performed before and 2 weeks after the irradiation in all cases. After bolus administration of gadopentetate dimeglumine (Gd-DTPA) (0.1 mmol kg), images were obtained every 30 s (repetition time 200 ms, echo time 16 ms) using a 1.5 or 0.5-T superconductive unit. Biopsy or surgery was performed after radiation therapy and the histologic findings were correlated with the MRI findings (T1, T2, dynamic, and enhanced T1). RESULTS: Complete remission, partial response, and no response were obtained in 18, 36, and 7 cases, respectively. Dynamic MRI correctly diagnosed 17 of the 18 complete remission cases, 33 of the 36 partial response cases, and all of the 7 no-response cases. The accuracy of dynamic MRI, T1-weighted image, T2-weighted image, and Gd-enhanced T1-weighted image was 94.4%, 68%, 82%, and 86%, respectively. CONCLUSION: Dynamic MRI proved to be useful in the evaluation of the radiation therapy of head and neck cancers.

Adult↗
PubMed1997

The effect of azelastine on acute radiation dermatitis in mice models.

PURPOSE: In our previous report we described the clinical value of azelastine, an oral antiallergic agent, as an inhibitor of radiation dermatitis. Here we studied the effect of azelastine on normal skin and tumor size after irradiation in a mouse model. METHODS AND MATERIALS: The modifying effects of azelastine on both the degree of radiation dermatitis and antitumoral effect of radiation therapy were investigated in the normal skin as well as in SCC VII tumors of C3H/He mice. The right hind legs, with or without tumors, were irradiated with 20-60 Gy at 0.62 Gy/min. Azelastine was administered via the mouse chow, and acute skin reactions and tumor growth curves were compared between the azelastine and control groups. RESULTS: The acute skin reactions of the azelastine group were significantly less prominent than those of the control group (p < 0.01). At a dose of 40 Gy the dose modification factors were 1.19-1.25. The tumor growth curves of the azelastine and control groups were almost identical, indicating that the treatment response of irradiation was not affected by administration of azelastine. CONCLUSIONS: Application of azelastine reduces the degree of acute radiation dermatitis without affecting the antitumoral effect of radiation therapy.

Animals↗
PubMed1997

Percutaneous microwave coagulation therapy in liver tumors. A 3-year experience.

PURPOSE: Percutaneous microwave coagulation therapy (PMCT) is an interventional alternative for inoperable malignant liver tumors. In this paper, we report the results of our 3-year experience of PMCT in order to establish suitable indications for this treatment. MATERIAL AND METHODS: We studied a total of 27 inoperable liver tumors in 24 patients. Histology of the tumors showed 20 hepatocellular carcinomas (HCCs) (13 well differentiated, 4 moderately differentiated, and 3 poorly differentiated) and 7 metastases. These tumors were treated by PMCT and were followed for 4-40 months (average 18 months). Under US guidance, the tumors were coagulated by microwaves emitted from an electrode. The changes of tumor size after PMCT were evaluated by CT. When the tumors disappeared or were reduced in size after treatment, PMCT was regarded as effective. Complications from PMCT were also evaluated. The patient survival rate was obtained by means of the Kaplan-Meier method. RESULTS: In tumors of 30 mm or less, treatment response was obtained in 70% of cases, while 55% of tumors larger than 30 mm responded. The tumor became smaller or disappeared in 85% of the well differentiated HCCs, and in 25% of the moderately differentiated HCCs, but none of the poorly differentiated HCCs responded. In metastatic tumors, PMCT was effective in 57% of cases. Slight pain (24%), fever (20%) and subcutaneous hematoma (8%) were experienced immediately after PMCT. In 2 poorly differentiated HCCs, needle tract seeding was observed. No case of liver dysfunction was seen after PMCT. The overall survival rate was 83.1% at 1 year and 68.7% at 2 years. CONCLUSION: Good therapeutic results were achieved with PMCT in lesions of 30 mm or less, and in well differentiated HCCs.

Aged↗
PubMed1997

The effect of starvation on brain carnitine concentration in neonatal rats.

BACKGROUND: We examined carnitine concentrations in fasted neonatal rat brain to evaluate the effect of starvation on fatty acid metabolism. METHODS: The free- and acylcarnitine concentrations in neonatal rat brain and heart were determined after a 72-hour starvation period from the 3rd to 6th postnatal day. They were also determined in rats at 3 and 6 days of age fed normally by the mother rats as controls. RESULTS: In the brain, the mean free carnitine concentration in the fasted group showed an increase similar to that in normal rats and there was no difference between the fasted and 6-day-old control rats. However, the mean acylcarnitine concentration was significantly higher in the fasted group than in the control group at both 3 and 6 days of age. Almost all of the increased acylcarnitine in the fasted group was short-chain acylcarnitine. In the heart, there was no difference in the mean free carnitine concentration between the fasted group and control group at 6 days of age. The 6-day-old rats in both the fasted and control groups showed higher levels compared to 3-day-old rats in the control group. The mean acylcarnitine concentration in the fasted group was not different from that in control group at 6 days of age, while the amount of short-chain acylcarnitine was less than that in the control group at 6 days of age. CONCLUSIONS: These findings suggest that in the brain, carnitine is accumulated as a result of redistribution during starvation, and is utilized for energy supply by fatty acid oxidation.

Aging↗
PubMed1997

Myeloperoxidase-specific anti-neutrophil cytoplasmic autoantibodies -- related scleroderma renal crisis treated with double-filtration plasmapheresis.

A 46-year-old female patient who was diagnosed with systemic sclerosis (SSc) developed rapidly progressive renal failure without elevation of blood pressure or plasma renin concentration. Renal biopsy revealed necrotizing crescentic glomerulonephritis (pauci-immune type) and the myeloperoxidase-specific anti-neutrophil cytoplasmic autoantibodies (MPO-ANCA) titer was found to be elevated to 669 EU/ml. Methylprednisolone (MP) pulse therapy followed by prednisolone (PSL) and mizoribine (MZR) did not suppress the progression of renal failure. Therefore, we started double-filtration plasmapheresis (DFPP) which effectively removed MPO-ANCA and prevented renal failure despite the relatively low dose of immunosuppressive agents.

Acute Kidney Injury↗
PubMed1997

[Diagnostic imaging of "body packers"].

Drug smuggling by intra-abdominal concealment, so called "body packing," has recently increased, even in Japan. Because of fatal drug intoxication and other adverse side effects, it is important to make a radiological diagnosis of body packers as soon as possible. A retrospective analysis of the images of plain abdominal radiography, computed tomography (CT) and ultrasound (US) was performed in twenty-three body packers to evaluate the imaging characteristics of three drugs (cannabis, cocaine and heroin). Cannabis (16 patients) and cocaine (5 patients) packages were demonstrated as well-demarcated rectangular-shaped high-density shadows surrounded by gas halo ("double condom sign") in abdominal plain radiographs and CT. Heroin packages (2 patients) were demonstrated as obscure shadows and were difficult to identify on plain radiographs, because they resembled stool masses. US was performed in one cannabis patient because of the refusal of radiological examination, and packages were demonstrated as round echogenic structures with dorsal echo extinctions. In conclusion, abdominal plain radiography, CT and US represent valuable diagnostic modalities in the assessment of body packers.

Abdomen↗
PubMed1997

CT and MR findings of denervated tongue after radical neck dissection.

PURPOSE: To describe the CT and MR findings in the denervated tongue after a radical neck dissection. METHODS: We retrospectively evaluated the radiologic findings in seven patients who had hypoglossal paralysis following radical neck dissection. None of the patients had clinical or radiologic evidence of tumor recurrence. RESULTS: The side of the tongue operated on showed low density on CT scans. At MR imaging, denervated tongues were clearly seen as hyperintense relative to muscle on T2-weighted images; on T1-weighted images, the signal was hypointense to hyperintense, representing increased extracellular water or fatty degeneration. CONCLUSION: In patients who have undergone a neck dissection for a malignant process, abnormal imaging findings in the tongue not only might indicate a recurrence of tumor involving the hypoglossal nerve but also suggest the possibility of postoperative change. Our findings emphasize the importance of the denervated tongue in differentiating inflammatory from neoplastic diseases of the the tongue.

Adult↗
PubMed1996

Versatility of the thin groin flap.

The groin flap is one of the most usable flaps. It provides a large amount of skin coverage with an easily concealed donor site. However, when the flap is used to reconstruct areas of the neck, hand, or foot, a secondary procedure for defatting is usually necessary. Thinner flaps are thought to be more useful in these areas. We present an anatomical study of the thin groin flap, including its dissection and defatting, and 12 clinical cases using the thin groin flap for neck (n = 7), foot (n = 4), and scalp (n = 1) reconstruction. The largest successful flap measured 13 x 30 cm. Eight flaps survived completely, two had partial necrosis, and two had total necrosis. Complications were thought to be caused by dissection around the pedicle. Meticulous dissection and thinning are required to create the thin groin flap. Excellent aesthetic results requiring no secondary defatting procedures are possible with this new thin groin flap.

Adolescent↗
PubMed1996

Increased serotonin release across the coronary bed during a nonischemic interval in patients with vasospastic angina.

BACKGROUND: Platelet activation and coagulation abnormality have been observed during coronary spasm. It is crucial whether platelet activation occurs even during a nonischemic period. HYPOTHESIS: This study was designed to determine whether platelets might be activated across the coronary bed during a nonischemic interval in patients with vasospastic angina. METHODS: Plasma levels of serotonin, 6-keto-prostaglandin F1 alpha, and catecholamines in the aorta and the coronary sinus were simultaneously measured in 16 patients with vasospastic angina and 13 control patients with nonischemic heart disease. RESULTS: None of these patients showed myocardial ischemia during sampling. The difference in transcardiac plasma levels of serotonin in patients with vasospastic angina was significantly higher than that in controls (1.48 +/- 1.08 ng/ml vs. 0.07 +/- 0.12 ng/ml, respectively, p < 0.001). Coronary sinus plasma norepinephrine levels in these two groups were almost the same (204.8 +/- 110.8 pg/ml vs. 190.4 +/- 131.6 pg/ml, respectively). The ratio of 6-keto-prostaglandin F1 alpha in the coronary sinus and the aorta was not different between the two groups (1.17 +/- 0.96 in patients with vasospastic angina vs. 1.15 +/- 0.68 in controls). CONCLUSIONS: These data suggest that platelet activation across the coronary bed should be ascribed to endothelial dysfunction. Lack of compensatory enhancement of prostacyclin production might be concerned with dysfunction of coronary endothelial cells in these patients.

6-Ketoprostaglandin F1 alpha↗
PubMed1996

Ethanol sclerosis can be a safe and useful treatment for pericardial cyst.

We report the case of a 41-year-old man with a pericardial cyst treated by percutaneous aspiration and ethanol injection. He was referred to our hospital because of electrocardiographic abnormality. On admission, chest x-ray revealed a large pericardial cyst in the right cardiophrenic angle. The cyst was examined by echocardiography, computed tomography, and cytological analysis of aspiration fluid from the cyst. Ethanol sclerosis was applied for treatment of the cyst, which had continued to increase in size. There was no recurrence of the cyst 6 months after the treatment. Percutaneous ethanol sclerosis can be the first choice of treatment for pericardial cyst.

Adult↗
PubMed1996

Effect of iomeprol on renal function immediately after abdominal angiography.

PURPOSE: To investigate the acute renal effects of 2 osmolality levels of iomeprol in a double-blind, randomized, parallel-group study. MATERIAL AND METHODS: Ten patients received iomeprol 300 mg I/ml, and a further 10 received iomeprol 400 mg I/ml intraarterially at routine abdominal angiography. The mean volume of contrast medium administered was 227.3+/-59.3 ml in the iomeprol 300 group and 221.5+/-30.9 ml in the iomeprol 400 group. RESULTS: The urinary minute volume increased immediately after angiography, but tended to return to baseline 120 min after the examination. No significant decrease in creatinine clearance occurred; however, the fraction excretion of sodium increased immediately after angiography. The lysosomal enzyme N-acetyl-beta-glucosaminidase and the proximal tubular brush border enzyme gamma-glutamyl transferase increased up to 120 min after the procedure. Free water clearance was negative during each study period. No statistical differences in any parameter were evident between these 2 groups. CONCLUSION: These results suggest that osmotic diuresis and its acute effect on proximal tubular function are induced by the administration of iomeprol, but that these changes are reversible.

Abdomen↗
PubMed1996

Short communication: the value of embolization therapy in painful osseous metastases from hepatocellular carcinomas; comparative study with radiation therapy.

We evaluated the therapeutic effect of transcatheter arterial embolization therapy (TAE) for painful osseous metastases from hepatocellular carcinoma (HCC) in comparison with radiation therapy (RT). TAE using gelatin sponge particles was performed for seven lesions in seven patients. Selective catheterization and embolization were successfully performed in all lesions. Within 10 days after TAE, complete pain relief (CR), partial relief (PR) and no relief (NR) were attained in 57%, 29% and 14%, respectively. RT was used to treat 34 lesions in 22 patients. The dose fractionation schedules were in the range 28.0-50.4 Gy, with 1.8-4.0 Gy per fraction. CR, PR and NR were attained in 47%, 47% and 6%, respectively. There were no serious complications related to these treatments. Both TAE and RT are effective and the treatment of choice should be selected on an individual basis.

Bone Neoplasms↗
PubMed1996

hiiragi, a gene essential for wing development in Drosophila melanogaster, affects the Notch cascade.

A recessive mutation, hiiragiP1, on the second chromosome of Drosophila was obtained by P element insertion mutagenesis. Flies homozygous for hiiragiP1 have notched wing margins. Genetic interactions between hiiragi and the genes that encode components of Notch signaling, such as Notch, Hairless, Serrate and deltex, strongly support the involvement of hiiragi in the signal transduction cascade of Notch. It has been reported that Serrate and Delta, other components of Notch signaling, share EGF-like repeats and a second conserved cysteine-rich motif, and that these components interact physically with the same region of Notch. In hiiragiP1; SerrateD/+ double mutants, we observed synergistic enhancement of the notched phenotype of wing margins. In contrast, Delta FX3 had no phenotypic effect on hiiragiP1 in hiiragiP1; Delta FX3/+ double mutants. Taken together, these results indicate that hiiragi is involved in the Notch signaling cascade induced by Serrate rather than by Delta.

Animals↗
PubMed1996

Loss of ganciclovir sensitivity by exclusion of thymidine kinase gene from transplanted proinsulin-producing fibroblasts as a gene therapy model for diabetes.

To establish a practical method of somatic gene therapy, we aimed to develop a regulatory system at the cellular level using a suicide vector. We introduced the herpes simplex virus type 1 thymidine kinase (HSV-tk) gene into the human proinsulin-producing Ltk-cells and examined whether ganciclovir (GCV) administration could control proinsulin production in vivo. The cells transfected with the HSV-tk gene showed more than 100-fold increase in sensitivity to GCV compared with the parent cells. Analysis of blood glucose in diabetic nude mice with transplanted cells showed that proinsulin production by these cells was strongly suppressed by GCV treatment in vivo as reflected by the reversal to hyperglycemia. However, in the in vivo experiment, the plasmid containing the HSV-tk gene was spontaneously lost from the transplanted cells in one of six cases resulting in the resistance to GCV as reflected by the persistent hypoglycemia and increased tumor size. This system of HSV-tk and administration of GCV may be applicable to gene therapy as a suicide vector, but the system of stable expression of the HSV-tk gene must be established.

Animals↗