Biomedical subjects

M Minami

Publications and source records attributed to M Minami.

713 records · Page 40Linked to original sources

PubMedDate not supplied

Diagnosis of coexistent hepatic tumors of different kinds: a challenge from CT and MR imaging.

Three cases of multiple, different liver tumors in the same patient were examined with CT and MR imaging. Two patients with coexistent hepatocellular carcinoma and cavernous hemangioma were correctly diagnosed by the following characteristic findings on dynamic CT and/or MR images; spreading and markedly prolonged enhancement in cavernous hemangioma, and the presence of capsule and/or transient diffuse enhancement in hepatocellular carcinoma. The third case of hepatocellular carcinoma and cholangiocarcinoma showed typical findings of hepatocellular carcinoma in one tumor and unusual complex enhancement in the other. CT and MR imaging may enable correct diagnosis to be made even in patients with multiple liver tumors of different kinds.

Adenoma, Bile Duct↗

PubMedDate not supplied

Effect of SM-2470, a newly synthetized alpha 1-adrenoceptor antagonist, on sympathetic nerve activity in anesthetized rats.

The newly synthetized alpha 1-adrenoceptor antagonist, SM-2470 (4-amino-2-[4-(bicyclo(2,2,2)oct-2-ene-5-carbonyl)-1-piperazinyl]-6,7- dimethoxyquinazoline hydrochloride), is a prazosin-like quinazoline derivative. The present study was undertaken to elucidate the effect of SM-2470 on sympathetic nerve activity and baroreceptor afferent nerve activity in anesthetized rats. Intravenous administration of SM-2470 (10, 30 and 100 micrograms/kg) produced a dose-dependent reduction of mean arterial pressure without any significant change in heart rate. SM-2470 caused decreases in both renal and cardiac sympathetic nerve activity along with this hypotension. Preganglionic adrenal nerve activity and aortic depressor nerve activity were also decreased by SM-2470. When equi-hypotensive doses of SM-2470 and clonidine were compared, the sympathoinhibitory potency of SM-2470 was less than that of the centrally acting antihypertensive drug, clonidine. Pretreatment with SM-2470 (30 micrograms/kg, i.v.) shifted the methoxamine-induced pressor response curve to the right. These findings suggest that SM-2470 may possess a central sympathoinhibitory action. This central action may play a role in its anti-tachycardic effect and may be substantially responsible for the hypotensive action.

Adrenergic alpha-Antagonists↗

PubMedDate not supplied

31P-NMR spectroscopy of myopathies: clinical application of whole-body MR.

Patients with myopathies were examined by 31P-NMR spectroscopy using a whole body MR system operating at 1.5 T. Spectra from the femoral muscles were measured as a function of time during a post-exercise recovery period. A 4-min scanning time was used to obtain a good S/N ratio and enable us to evaluate the relative intensity and position of each absorption line. The results were expressed by PCr/Pi ratio and pH value and compared with values before exercise. Clear changes were observed in the recovery process after workload depending on the stage of disease. We were able to observe the in vivo dynamic energy metabolism of myopathies by whole-body MR.

Adult↗

PubMedDate not supplied

Semiquantitative analysis of fatty liver using spectroscopic imaging by dephasing amplitude changing (SIDAC).

The potential utility of spectroscopic imaging by dephasing amplitude changing (SIDAC) was evaluated in fatty infiltration in rats induced by cholesterol and ethanol. There was an excellent correlation between the in vivo fat-to-water ratio obtained from SIDAC and that in liver specimens from in vitro measurement (r = 0.97). SIDAC is a promising method for semiquantitative analysis of fatty infiltration of the liver.

Animals↗

PubMedDate not supplied

Bone scintigraphy in Maffucci syndrome.

Maffucci syndrome is a congenital, non-hereditary mesodermal dysplasia associated with multiple enchondromas and hemangiomas. The high risk of development of malignant tumors is well-known. A case of Maffucci syndrome in a 68-year-old man who suffered from multiple malignant degeneration and who was given a bone scintigraphic examination is reported with radiological and pathological findings. The scintigraphic findings are different for two histological different chondrosarcomatous lesions. It seems that uptake of Tc-99m MDP increases with the degree of calcification rather than whether the lesion is benign or malignant.

Aged↗

PubMedDate not supplied

Histamine release from pulmonary mast cells after lung transplantation in rats.

BACKGROUND AND METHODS: On the assumption that lung mast cells might respond and release histamine after lung transplantation, the number of mast cells and tissue histamine content were investigated for 2 weeks after rat orthotopic left lung isotransplantation (Lewis rat to Lewis rat) and allotransplantation (Lewis rat to Brown Norway rat). The allografts were rejected histologically by day 7 (grade A4). RESULTS: In the isografts, both the numbers of mast cells and histamine content were lower (p < 0.05) on day 4 but higher (p < 0.001) on day 14 compared with the nontransplanted donor left lungs (control). In the allografts, the numbers of mast cells on day 7 and histamine content on day 1 were lower (p < 0.05) than controls and both continued to be low thereafter. On day 7, the histamine content of the allografts was low (p < 0.05) compared with the level of the isografts. Conversely, no significant change was found in histamine content of the untransplanted right native lungs except for on day 14 after isotransplantation, when the content was higher than the controls, suggesting the possibility of a systemic signal for proliferation of mast cells. CONCLUSIONS: Our data indicated that degranulation of the pulmonary mast cells and consequent histamine release localized in the grafts occurred under the microenvironment of reimplantation and rejection after rat lung transplantation.

Animals↗

PubMedDate not supplied

Site-directed mutagenesis of leukotriene A4 hydrolase: distinction of leukotriene A4 hydrolase and aminopeptidase activities.

Leukotriene (LT) A4 hydrolase catalyzes enzymatic hydration of LTA4 to biologically active substance, LTB4. Biochemical and immuno-histochemical studies have shown that this enzyme is ubiquitously distributed in various cells and tissues. A sequence domain of LTA4 hydrolase was found to be homologous to those of several zinc metalloproteases. Both native and recombinant enzymes were shown to possess equimolar zinc ion and aminopeptidase activity. To examine the molecular mechanism of this enzyme reaction, site-directed mutagenesis experiments were carried out. Single amino acid substitutions at Glu-297 revealed a distinction of two enzyme activities, and suggest that the glutamic acid residue at 297 is essential for aminopeptidase, while the side chain of Glu or Gln is required for LTA4 hydrolase activity. The loss of two enzyme activities in a mutant E319K confirmed the proposal that the presence of a zinc ion in the enzyme is required for both enzyme activities.

Amino Acid Sequence↗

PubMedDate not supplied

Warthin tumor of the parotid gland: MR-pathologic correlation.

PURPOSE: To describe the MR appearance of Warthin tumor and correlate the images with pathologic sections. METHODS: MR studies of seven patients with Warthin tumors in the parotid gland were retrospectively reviewed; MR results were compared with pathologic specimens in five instances. FINDINGS: One patient had a bilateral tumor; another had three tumors in the right parotid gland and one in the left. Ten tumors showed well-defined borders; the other, which was accompanied by infection, had an indefinite border only at the upper pole. All had thin capsules not shown on MR. Four showed small lobulations at the margins. Fibrosis appeared as septa-like structures of low signal intensity in three cases. There were areas of hemorrhage with accumulation of hemosiderin in two cases. All tumors had low or intermediate T1-weighted signal intensity, four with high intensity areas of cysts containing cholesterol crystals. On T2W images, two tumors had homogeneously intermediate intensity; the other nine had mixed intensity. Areas of intermediate intensity were correlated with abundant epithelial tissues; focal high-intensity areas were correlated with cysts and/or areas of predominant lymphoid proliferation. CONCLUSIONS: MR findings such as bilaterality and/or multiplicity, well-defined margins, and predominantly intermediate signal intensity on T1W and T2W images with focal areas of high signal intensities on T1W images suggest Warthin tumor, but are not pathognomonic.

Adenolymphoma↗

PubMedDate not supplied

Hepatocellular carcinoma: comparative study among precontrast, artery-dominant, and delayed-contrast phase images at ultrafast CT.

To evaluate the detectability of hepatocellular carcinoma (HCC) at artery-dominant phase and to compare it with that at precontrast and delayed-contrast phases, 34 patients with 109 HCCs were examined by ultrafast computed tomography (CT) using an incremental dynamic technique under single breath-holding. Images of three phases (precontrast, artery-dominant, and delayed) were compared with iodized-oil CT images. None of the lesions were detected only at precontrast phase. HCC detectability at the artery-dominant phase (87/109, 80%) was significantly superior to that at precontrast phase (32/109, 29%) (p < .01) and delayed-contrast phase (57/109, 52%) (p < .01). All 31 lesions missed at delayed-contrast phase were depicted at artery-dominant phase, while one lesion observed at delayed-contrast phase was missed at artery-dominant phase. Incremental dynamic CT at artery-dominant phase was suitable for the diagnosis of HCCs. Precontrast phase images were not necessary, although delayed-phase images were useful for the evaluation of tumor extension in some cases.

Aged↗

PubMedDate not supplied

Breast conserving treatment versus modified radical mastectomy in Japanese patients with operable breast cancer.

From January, 1988 to October, 1995, 96 patients with operable breast cancer were treated by breast conserving treatment (BCT) including wide excision and axillary dissection followed by breast radiation. During the same period, 188 patients were treated by modified radical mastectomy (MRM) with or without breast reconstruction. In order to compare the survival of BCT and MRM groups, univariate and multivariate analyses were performed in this retrospective study. Univariate analysis revealed that the 5-year survival rates in the BCT and MRM groups were 97% +/- 2% and 87% +/- 3%, respectively (p < 0.05 with the Cox-Mantel test). However, the baseline variables were different between the groups. The adjusted Cox regression analysis revealed that the results of BCT were almost equivalent with those of MRM. Moreover, no breast recurrence was found in the BCT group. Therefore, it is suggested that our technique of BCT is as effective as modified radical mastectomy in treating operable breast cancer in Japanese patients.

Adult↗

PubMedDate not supplied

Central dot sign in entities other than Caroli disease.

OBJECTIVE: The purpose of this study was to describe central dot sign (tiny dots with strong contrast enhancement of the portal vein within dilated hepatic bile ducts on computed tomography) in entities other than Caroli disease, especially in peribiliary cysts with or without autosomal-dominant polycystic kidney disease. MATERIALS AND METHODS: Computed tomography in 74 cases of peribiliary cysts and 134 cases of other liver diseases and states possibly showing central dot sign were retrospectively reviewed to examine the central dot sign. RESULTS: In three cases of peribiliary cysts, some part of the liver showed strongly enhanced portal radicles surrounded completely or partially by low-attenuation, enlarged peribiliary cysts, presenting "central dot sign" on contrast-enhanced computed tomography. CONCLUSION: We suggest that in addition to Caroli disease, some other entities and diseases of the liver may demonstrate central dot sign and this sign should not be considered a specific finding of Caroli disease.

Adult↗