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Biomedical subjects

M Eguchi

Publications and source records attributed to M Eguchi.

281 records · Page 16Linked to original sources
PubMedDate not supplied

Two- and three-dimensional assessments of myocardial perfusion and function by using technetium-99m sestamibi gated SPECT with a combination of count- and image-based techniques.

BACKGROUND: Although the myocardial gated single photon emission computed tomography (SPECT) technique makes it possible to assess concurrent myocardial perfusion and function, quantitative methods for analyzing and displaying gated SPECT data in 2- and 3-dimensional presentations for regional and global cardiac assessment have not been established. METHODS AND RESULTS: We have developed an automated quantitative method for assessing perfusion and function by means of technetium-99m sestamibi gated SPECT with a computerized technique combining count-based and image-based methods. We have examined its validity in 91 patients by comparing its results with those of conventional techniques: contrast left ventriculography and radionuclide angiocardiography. In addition to color-scale displays of regional function, simultaneous 3-dimensional presentations of regional wall motion and perfusion have been produced. High reproducibility of gated SPECT analysis with this algorithm was demonstrated; interoperator errors (%CV) were 2.6% to 5.5%, and good intraobserver reproducibility was confirmed by means of high correlation coefficients (0.954 to 0.989). Left ventricular volumes assessed by means of contrast left ventriculography and by means of the gated SPECT technique showed significant correlations (left ventricular end-diastolic volume, y = 1.01x - 9.7, r = 0.845, P<.001, standard errors of the estimate [SEE] = 14 mL; left ventricular end-systolic volume, y = 1.03x - 1.4, r = 0.902, P<.001, SEE = 6 mL). Left ventricular ejection fraction determined by means of gated SPECT with the new algorithm closely correlated with that determined by means of radionuclide ventriculography (y = 1.05x - 0.6, r = 0.891, P<.001, SEE = 3 %). These parameters quantified by means of the present method correlated closely with those derived from the QGS program (r = 0.926 to 0.987). CONCLUSION: In comparison with conventional techniques, myocardial gated SPECT with automated quantitative analysis provides accurate and reproducible data for global and regional function. Quantitative concurrent assessment of myocardial perfusion and function by using 2-and 3-dimensional representations appears to be superior to other modalities and to contribute to nuclear cardiology practice.

Adult↗
PubMedDate not supplied

Detection of cardiac calcinosis in hemodialysis patients by whole-body scintigraphy with 99m-technetium methylene diphosphonate.

A noninvasive method for the diagnosis of cardiac calcinosis, a life-threatening complication in hemodialysis patients with end-stage renal disease (ESRD), has not, as yet, been firmly established. We tested whether whole body scanning with 99m-technetium methylene diphosphonate (MDP) might visualize cardiac calcinosis. In 19 consecutive chronic hemodialysis ESRD patients (13 males and 6 females, aged 40-81, mean 63 +/- 8 years) with cardiovascular disease [mitral annular calcinosis and/or calcified aortic valve (n = 4), hemodialysis cardiomyopathy (n = 1), coronary artery disease (n = 9) and peripheral artery atherosclerotic disease (n = 6)], MDP uptake in the heart was compared to that in 7 non-ESRD controls with hyperparathyroidism due to adenoma. Cardiac and lung field MDP uptake was confirmed in only 3 (16%) and 5 (26%) of the 19 ESRD subjects, respectively, but was absent in controls. Positive cardiac uptake was related to cardiac calcified complications (mobile intracardiac calcinosis, myocardial calcinosis and mitral annular calcification) and the duration of hemodialysis (p = 0.015). While it was statistically insignificant, subjects showing MDP uptake were elder and had higher serum Ca or Ca x P product and lower intact parathyroid hormone levels. These results suggest that cardiac calcinosis in ESRD patients can be detected noninvasively by myocardial scintigraphy with 99m-technetium MDP.

Adult↗
PubMedDate not supplied

Ultrastructural detection of RNA in leukemic cells by the RNase-gold method.

We analyzed semiquantitatively the ultrastructural distribution of RNA by the RNase-gold method in 40 patients with acute leukemia (20 patients with AML and 20 with ALL) before the initial treatment. The number of gold particles showing the presence of RNA was high in the granular component of the nucleolus and cytoplasm but low in the fibrillar component of the nucleolus, granules, the Golgi area, and Auer bodies. The number of gold particles in the nucleolus, nucleus, or cytoplasm was higher in AML than in ALL (p less than 0.01). The RNase-gold method seems to be useful for evaluating the capacity of protein synthesis, maturity, or differentiation of leukemic cells.

Adolescent↗
PubMedDate not supplied

Ultrastructure of well-differentiated adenocarcinoma of the gallbladder.

The ultrastructure of four well-differentiated adenocarcinomas of the gallbladder was investigated by scanning and transmission electron microscopy and compared with the ultrastructure of nonneoplastic mucosa in the same specimens and of the mucosa of gallbladders with gallstones. The tumor cells seen by scanning electron microscopy had severe disorganization of the regular arrangement of columnar cells. They were bizarre in shape and size and were covered with less developed pleomorphic microvilli that were irregularly distributed. No such findings appeared in the control specimens. The tumor cells seen by transmission electron microscopy exhibited pleomorphic microvilli, well-developed cytoplasmic organelles, various mucus granules, abundant lysosomes, and nuclear changes. These findings suggest increased secretory and metabolic activity in the tumor cells. Gobletlike cells, Paneth-like cells, and endocrine cells were scattered in two of the carcinomas. These cells were also noted in the nonneoplastic mucosa of the carcinoma specimens but were rare in the mucosa when cholelithiasis was present.

Adenocarcinoma↗
PubMedDate not supplied

Pluripotent hemopoietic stem cells in murine postmortem bone marrow.

Although 12-hours postmortem murine bone marrow cells exhibit extensive degeneration, these cells when infused into irradiated mice produce erythrocytic, granulocytic, megakarocytic and mixed colonies in their spleen. These observations clearly demonstrate the presence of pluripotent hemopoietic stem cells and their proliferative capability in 12-hours postmortem, murine bone marrow. These observations suggest that cadaveric bone marrow transplantation may be possible in patients with hematologic disorders.

Animals↗
PubMedDate not supplied

Socket and cup surface replacement of the hip.

To improve the surgical results of severe osteoarthritis of the hip, surface replacement of the hip using a double cup without cement was employed on 75 hips during the period from 1972 to 1977. The results of the procedures have been analyzed on 67 hips followed for more than 6 months. The most dramatic improvement following the procedure has been pain relief, observed in 58 of 67 hips (86%). Three reoperations were necessary. Failures were treated satisfactorily either by total hip replacement, or by arthrodesis and/or by placing a new cup on the head respectively. There was no operative death, pulmonary embolism, thrombophlebitis, nor deep infection. We do not think this procedure replaces more definitive surgery such as the Charnley-type total hip replacement, but it is a good adjunctive procedure particularly in patients younger than 60 years of age.

Acetabulum↗
PubMedDate not supplied

In vitro and in vivo assessment of the viability of cryopreserved postmortem murine bone marrow cells.

The viability of cryopreserved mouse fresh and postmortem bone marrow cells was studied using methylcellulose clonal cell culture assay and the murine spleen colony technique. This study clearly indicates the presence of pluripotent hemopoietic stem cells in cryopreserved murine postmortem bone marrow cells. The viability of granulocytic precursors in both fresh and postmortem bone marrow cells was mildly to moderately decreased by the freezing process, while the proliferative capacity of erythrocytic stem cells is significantly decreased by cryopreservation. The results strongly suggest that frozen, fresh and cadaveric bone marrow bank for bone marrow transplantation may be of value.

Animals↗
PubMedDate not supplied

Two cases of ganglion cysts in the lumbar spinal canal.

Two cases of ganglion cysts in the lumbar spinal canal: MR findings. Ganglion cysts in the spinal canal are rare. To our knowledge, only 12 cases have been reported. In addition, ganglion cysts depicted by MR are extremely rare. We report the MR findings in two cases of ganglion cysts in the lumbar spinal canal. In both cases, the ganglion cysts were slightly higher in intensity than CSF on T2-weighted images. In addition, a thin band of low intensity was depicted around the ganglion in both cases. This finding may help to diagnose ganglion in the spinal canal. On T1-weighted images, the signal intensity of the ganglion was very similar to that of the intervertebral disc in both cases. In summary, although ganglion mimics disc hernia or sequestrated disc on both T2- and T1-weighted images, the possibility of a ganglion should be considered whenever an extradural mass showing high signal intensity surrounded by a thin band of low intensity is identified on T2-weighted images.

Adolescent↗
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

Intraosseous ganglion communicating with soft tissue counterpart.

We report the imaging and pathological findings of a rare case of intraosseous ganglion communicating with extraosseous counterpart. Both counterparts contain air and show rim-enhancement on T1-weighted images. Histopathologically, the enhanced-rim consists of reactive proliferation of capillary vessels due to degeneration.

Acetabulum↗