Search PubMed⌕ Search

Biomedical subjects

R Murakami

Publications and source records attributed to R Murakami.

At least 73 records · Page 4Linked to original sources
PubMed1998

Venous drainage through bone marrow after replantation: an experimental study.

Venous drainage is vital for successful replantation, but it is not always possible to reconstruct because of missing or damaged veins. We devised an experimental model to study venous drainage through bone marrow while the new subcutaneous venous system regenerated. Adult male Wistar rats were placed into three groups. Group A rats had their hindlimbs amputated at the lower leg, but the tibia and sural and saphenous artery connections were preserved. Group B rats were prepared the same as Group A, except that a step-cut osteotomy was performed in the tibia. The bone ends were then realigned and kept in place with stainless steel wire. Group C rats were prepared the same as Group B, except that the ends of the bone were not aligned. All unoperated limbs served as controls for evaluations of blood flow. Experimental limbs were evaluated for skin colour and viability, blood flow and dye injection. Skin colour was investigated daily. Blood flow was measured postoperatively during three phases: immediate (up to 1 h), early (from 1 h to 24 h), and late (from 1 day to 7 days after operation). Survival of limbs varied in Groups A and B, while all limbs in Group C necrosed by day 7. Blood flow was returning to near control (normal) levels by day 7 in Group A and B limbs. India ink was observed in the medullary cavity at day 7. After replantation, bone marrow plays a critical role in venous drainage until the subcutaneous venous drainage system regenerates.

Animals↗
PubMed1998

Free groin flap for reconstruction of the tongue and oral floor.

The authors report the use of free groin flaps to close intraoral defects in 24 patients following ablative tongue cancer surgery. The lateral thin portion of the flap was used for tongue reconstruction, and the deepithelialized medial thick portion for filling the mandibular defect and for covering the important vessels in the neck. In lean patients, if the medial deepithelialized portion was too thin for adequate coverage, the proximal sartorius muscle was included to prevent postoperative orocervical fistula. The advantages of the groin flap in reconstructing the tongue and oral floor after hemiglossectomy include the following: (1) a suitable amount of tissue is available for both the tongue and oral floor; (2) the important vessels in the neck may be protected with the flap; (3) the proximal sartorius muscle can be included with the flap, if necessary; (4) donor-site morbidity is less than with other flaps; and (5) flap elevation can be done concurrently with the hemiglossectomy and radical neck dissection.

Adult↗
PubMed1998

Effect of iodixanol on renal function immediately after abdominal angiography. Clinical comparison with iomeprol and ioxaglate.

PURPOSE: To investigate the acute renal effects of three contrast media in a double-blind randomized parallel-group study. The contrast media investigated were: the nonionic dimeric iso-osmolality medium iodixanol; the nonionic monomeric medium iomeprol; and the ionic dimeric medium ioxaglate. MATERIAL AND METHODS: A total of 30 patients were given the following doses of contrast medium: 10 patients received iodixanol 320 mg I/ml; 10 received iomeprol 300 mg I/ml; and 10 received ioxaglate 320 mg I/ml. The doses were given intra-arterially at routine abdominal angiography and the renal effects of these three contrast media were studied for up to 120 min after injection. RESULTS: The urinary minute volume increased immediately after angiography but tended to return to baseline values after 120 min; these changes were more pronounced with iomeprol and ioxaglate than with iodixanol. Creatinine clearance was not reduced by any of the contrast media. Fraction excretion of sodium increased immediately and lasted for 30 min after angiography; these changes were more pronounced with ioxaglate than with iomeprol and iodixanol. Urinary gamma-glutamyl transferase increased for 120 min after angiography with iodixanol and iomeprol; these changes were more pronounced with iomeprol than with iodixanol. On the other hand, urinary nu-acetyl-beta-glucosaminidase increased for 120 min after angiography with iomeprol, but was unchanged with iodixanol. CONCLUSION: The use of contrast media induces osmotic diuresis and its acute effects on the proximal tubular function. However, the iso-osmolality medium iodixanol induces fewer changes than the other two media.

Adult↗
PubMed1998

Transcardiac 5-hydroxytryptamine release and impaired coronary endothelial function in patients with vasospastic angina.

1. The present study was designed to test the hypotheses whether platelet degranulation across the coronary bed is detectable during non-ischaemic periods in patients with vasospastic angina (VSA) and whether the exogenous nitric oxide (NO) donor nitroglycerin (GTN) is able to modify platelet degranulation, reflecting an impaired endothelial production of NO. 2. We studied 13 patients with VSA and 10 controls. The time course of coronary sinus (CS) plasma 5-hydroxytryptamine (5-HT) levels was evaluated every 4 h before and after intravenous infusion of GTN over a period of 40 h. Coronary sinus plasma 5-HT levels were significantly higher at any measured time point in patients with VSA compared with control and were significantly decreased in patients with VSA following treatment with GTN, but not in controls. Femoral artery plasma 5-HT levels remained almost constant throughout the study. The ratio of CS:aorta 6-keto-prostaglandin F1 alpha was significantly and inversely correlated with the transcardiac plasma 5-HT difference only in patients with VSA (r = -0.68; P < 0.02; n = 13). 3. The time course of CS 5-HT levels confirmed significant platelet degranulation across the coronary bed supplied by the spasming artery in patients with VSA and this was modified by GTN. The present data suggest that platelet degranulation occurs during non-ischaemic periods in patients with VSA and that prostacyclin biosynthesis may be a compensatory response to an impaired endothelial release of NO, limiting the degree of the effects of platelet degranulation.

6-Ketoprostaglandin F1 alpha↗
PubMed1998

Use of fluid-attenuated inversion recovery (FLAIR) pulse sequences in perinatal hypoxic-ischaemic encephalopathy.

The purpose of this study was to evaluate the usefulness of fluid-attenuated inversion recovery (FLAIR) techniques in patients with perinatal hypoxic-ischaemic encephalopathy. 13 patients with a history of perinatal hypoxic-ischaemic encephalopathy (age range 1 month to 3.6 years) underwent T1 and T2 weighted spin echo and FLAIR imaging with a 1.5 T superconducting unit. FLAIR images were qualitatively evaluated in comparison with T1 and T2 weighted images by three experienced radiologists. Quantitative analysis (contrast and contrast-to-noise ratio) was also performed. FLAIR images were preferred to T1 and T2 weighted images in the demonstration of periventricular leukomalacia (PVL), cystic PVL and subcortical lesions near the brain surface. On T1 and T2 weighted images, almost all lesions were demonstrated as hypointense or hyperintense areas, respectively. However, FLAIR images could differentiate cystic lesions by their signal intensities. FLAIR images were not diagnostic in two cases with PVL. In conclusion FLAIR sequences provide useful information in patients with perinatal hypoxic-ischaemic encephalopathy.

Child, Preschool↗
PubMed1998

[A case of dermatomyositis associated with asymptomatic pneumomediastinum].

A 20-year-old woman initially presented with edematous erythema in the upper eyelids in December 1995. She was admitted to our department in January 1996 because of fever and multiple arthralgia. She was given a diagnosis of dermatomyositis (DM) on the basis of characteristic eruption, elevated serum level of creatine kinase, and increased inflammatory reaction. Chest computed tomography (CT) revealed faint interstitial changes in the left lower lung. The administration of corticosteroid caused improvement in the patient's condition and the interstitial lesion in the lung. Although she was asymptomatic, chest CT showed pneumomediastinum in the pretracheal space and concomitant pneumothorax around left bronchus. Those changes spontaneously disappeared 4 weeks later without treatment. The occurrence of pneumomediastinum in patients with DM has been well documented as an indicator of poor prognosis in the literature. It seems that a severe pulmonary disorder could secondary cause pneumomediastinum. In our case, however, the pneumomediastinum developed in spite of the low grade severity of the pulmonary lesion. This finding suggested that the pneumomediastinum may be associated with the development of DM itself.

Adult↗
PubMed1998

[A case of Sjögren's syndrome associated with inflammatory pseudotumor of the liver].

A 71-year-old man had noticed a dry sensation in the mouth with swelling of bilateral parotid glands in 1988. He was given a diagnosis of Sjögren's syndrome (SS) on the basis of characteristic findings of sialography and a minor salivary gland biopsy. He was admitted to our department in Febuary 1995 because of general fatigue of 2 month's duration. Laboratory data showed both positive anti-SSA and anti-SSB antibodies, liver dysfunction, hypoalbuminemia, and thrombocytopenia. Abdominal CT and MRI demonstrated a 2-cm intrahepatic mass (S 6) with enhanced areas at the periphery. The liver biopsy yielded fragments from the intrahepatic mass and hepatic parenchyma. The former was composed of plasma cells, lymphocytes, and histiocytes, compatible with the diagnosis of inflammatory pseudotumor of the liver. The pathological diagnosis of the latter specimen was primary biliary cirrhosis, although antimitochondrial antibody was negative. The intrahepatic mass gradually decreased in size without treatment. Inflammatory pseudotumor is considered to be a benign inflammatory condition simulating a neoplasma and the possibility of an autoimmune reaction is suggested on the basis of etiology. This is the first report of an inflammatory pseudotumor associated with Sjögren's syndrome developing in the liver. The inflammatory pseudotumor should be considered as a possible diagnosis in cases where the tumor is embedded in the liver.

Aged↗
PubMed1998

[A case of protein-losing gastroenteropathy in association with mixed connective tissue disease which was successfully treated with cyclophosphamide pulse therapy].

A 47-year-old man had been given a diagnosis of mixed connective tissue disease (MCTD) on 1987 when he had presented with Raynaud's phenomenon, polyarthralgia, sclerodactyly, and a high titre of anti-RNP antibody. Once his symptoms had improved following the administration of prednisolone orally and the treatment was discontinued since 1995. He noticed dyspnea and chest pain in February 1997. The bilateral pleural effusion was pointed out in the local hospital and he was admitted to our hospital in March 1997 for further examination. In addition to pleural effusion and ascites, laboratory studies revealed hypoalbuminemia and low serum levels of complements. Renal and liver function tests were normal and the urine gave a trace test for protein. The presence of protein loss in the gut was confirmed by an elevated alpha 1-antitrypsin clearance and 99mTc-albumin scintigraphy showing abnormal radioactivity in the gastrointestinal tract. Although endoscopic examination showed no abnormal findings macroscopically and gastrointestinal biopsies revealed nonspecific inflammation only, immunofluorescent studies demonstrated deposits of C 3, C 4 and IgG in the stomach, colon, and pleura. These findings supported the pathogenesis that immune deposits in tissues caused protein-losing gastroenteropathy (PLGE) in MCTD. Intravenous administration of cyclophosphamide started since July 1997, while the high-dose corticosteroid therapy including methylprednisolone pulse therapy were not effective. Hypoalbuminemia and low serum levels of complements improved remarkably and the pleural effusion and ascites disappeared after cyclophosphamide pulse therapy four times monthly. Cyclophosphamide pulse therapy should be considered as a possibly effective treatment for PLGE in association with collagen disease resistant to corticosteroid therapy.

Cyclophosphamide↗
PubMed1998

MR of denervated tongue: temporal changes after radical neck dissection.

PURPOSE: The purpose of this study was to evaluate the temporal changes of MR imaging in the denervated tongue after a radical neck dissection. METHODS: One hundred seventy-four consecutive MR studies in 116 patients with radical neck dissections for malignant tumors of the head and neck were evaluated retrospectively. Patients with tumors involving the tongue or hypoglossal nerve were not included in this study. RESULTS: Abnormal signal intensity and/or hemiatrophy on the side of the tongue operated on was seen in 22 patients who had hypoglossal paralysis after radical neck dissection. The denervated side of the tongue appeared hypointense to hyperintense relative to the normal side on T1-weighted images and hyperintense on T2-weighted images. Signal intensity ratios of the abnormal to normal muscles were 0.9-1.6 on T1-weighted images and 1.3-2.8 on T2-weighted images. High signal intensity on T1-weighted images appeared 5 months or more after the dissection, whereas on T2-weighted images, the most prominent increases in signal intensity appeared in the first several months after denervation. Hemiatrophy of the tongue was observed on MR images obtained more than 6 months after surgery. CONCLUSION: MR findings in the denervated tongue are compatible with histologic changes and are characterized by an enlarged extracellular fluid space or fatty infiltration. The pattern of signal intensity and the degree of hemiatrophy suggest the duration of denervation.

Adult↗
PubMed1998

MR sialography using half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequences.

We describe our preliminary experience with the half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequences for MR imaging of the salivary gland ducts. In the majority of patients, the main parotid and/or submandibular gland ducts and large branches within the glands were detectable on MR images obtained in 2 seconds per section and within 3 minutes for the entire examination. MR sialography using HASTE sequences can be combined with conventional MR studies for the salivary glands.

Adult↗
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↗