Biomedical subjects
Publications and source records attributed to T Ishida.
Acalculous cholecystitis occurred in a patient with Weber-Christian disease. It reflected a panniculitis similar to that which developed in the orbit, abdominal cavity, and the retroperitoneal space.
Postirradiation changes in the rectum and perirectal tissue were assessed by computed tomography (CT) in 55 patients (total of 60 examinations) and correlated with radiation dose and time elapsed. Thickening of the perirectal fascia, increased density of the perirectal fat, and swelling of the rectal wall occurred in 48, 60, and 8% of patients, respectively, regardless of radiation dose within 30 Gy. However, widening of the presacral space was seen in 8% of patients receiving a rectal dose of less than 45 Gy, a percentage that increased to 16% for patients receiving 45 Gy or more. Thickening of the perirectal fascia, increased density of the perirectal fat, widening of the presacral space, and muscular changes were seen regardless of the time from the start of therapy. CT does not appear to be reliable enough in detecting residual or recurrent tumor in the rectum. However, knowledge of the CT features of postirradiation changes is helpful for diagnosis in patients with pelvic malignancies.
The purpose of this study is to evaluate how virtual computed tomography (CT) endoscopy may help in assessing ossicles in the middle ear. Our series consisted of 96 ears of 68 consecutive patients with conducting hearing loss. All examinations were performed with a high-resolution spiral CT using axial and direct coronal planes of the temporal bone. Perspective virtual endoscopy was processed using the virtual endoscopic software. Superstructure of the stapes was difficult to evaluate on the virtual endoscopy; however, virtual endoscopy of the middle ear provides further information on the pathological conditions including congenital anomaly, posttraumatic, and inflammatory processes.
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This study presents a case of embryonal rhabdomyosarcoma (ERMS) of the forearm soft tissue in a 12-year-old female, in which microtubular aggregates in rough endoplasmic reticulum (rER) were noted ultrastructurally. Histologically, tumor cells consisted of typical rhabdomyoblastoid cells with abundant eosinophilic cytoplasm and relatively immature, small tumor cells. Ultrastructurally, two different types of tumor cells were also identified by light microscopy. More than half the tumor cells possessed the characteristic features of rhabdomyoblastic differentiation, such as abundant thick and thin filaments with Z-bands. The other tumor cells were less differentiated cells in which microtubular aggregates (MA) in rER were observed. MA in rER have been described in several nonepithelial tumors, including malignant melanoma, osteosarcoma, extraskeletal myxoid chondrosarcoma, and chordoma. ERMS is another example of mesenchymal tumor in which MA in rER are observed by electron microscopy. Considering the differential diagnosis among mesenchymal tumors, it is important to know that MA can be also observed in ERMS.
Codeinone-glutathione adduct (CO-GSH) in the bile of guinea pigs given a subcutaneous injection of codeine was isolated and identified. Synthesized authentic CO-GSH was characterized by the mass and nuclear magnetic resonance spectra and used as the standard sample. The metabolite was isolated by preparative high-performance liquid chromatography on a C18 column. The fractions containing the conjugated metabolite were purified using Sep-Pak C18 cartridges. For further purification of the metabolite CO-GSH, a Radial Pak CN column was used. Structure assignment of the metabolite was then performed by fast-atom-bombardment mass spectrometry and 500 MHz Fourier-transform-NMR spectrometric analysis and identified as S-[4,5-epoxy-3-methoxy-17-methyl-6-oxomorphinan-(8S)-yl] glutathione.
We determined nucleotide sequences of the 16S rRNA gene of mitochondrial DNA (mtDNA) (about 1.6 kb) for 35 chimpanzee, 13 bonobo, 10 gorilla, 16 orangutan, and 23 gibbon individuals. We compared those data with published sequences and estimated nucleotide diversity for each species. All the ape species showed higher diversity than human. We also constructed phylogenetic trees and networks. The two orangutan subspecies were clearly separated from each other, and Sumatran orangutans showed much higher nucleotide diversity than Bornean orangutans. Some gibbon species did not form monophyletic clusters, and variation within species was not much different from that among species in the subgenus Hylobates.
Amyloid deposition in the seminal vesicle is a not unusual finding at autopsy. A case of MR findings of amyloid deposition in the seminal vesicles with urinary bladder cancer is reported. Invasion of the seminal vesicle could not be excluded on T2-weighted imaging, but gadopentetate dimeglumine may be useful in its ability to differentiate amyloid deposition from seminal vesicle tumor invasion.
OBJECTIVE: Gonadotropin-releasing hormone (GnRH) analogues have been advocated for the conservative management of uterine leiomyoma. These drugs induce a hypoestrogenic state and affect undegenerated myoma cells. Therefore, we evaluated the usefulness of MRI for distinguishing undegenerated and degenerated leiomyomas. MATERIALS AND METHODS: Twenty lesions were studied in 16 patients with surgically resected leiomyoma. A 1.5 T unit was used to obtain T1- and T2-weighted images and Gd-DTPA-enhanced T1-weighted images. Signal intensity maps were made for each pulse sequence, and detailed histological maps were also made in the same plane as the MR images. Then the MR maps were compared with the histological maps of the resected specimens. RESULTS: Interstitial edema, the initial sign of degeneration, was detected as a high signal intensity region on T2-weighted images and showed enhancement with Gd-DTPA. Hyaline degeneration could not be distinguished from smooth muscle whorls on T1- and T2-weighted images. However, undegenerated leiomyoma could be distinguished from hyaline degeneration, because the former was slightly enhanced by Gd-DTPA but the latter was not. CONCLUSION: These findings showed that Gd-DTPA-enhanced MRI can distinguish undegenerated leiomyomas from degenerated leiomyomas and suggest that MRI may be useful for predicting the response of this tumor to GnRH analogue therapy.
OBJECTIVE: We assessed the value of dynamic sequential three-dimensional Fourier transformation (3DFT) MRI in differentiating various types of small liver tumors. MATERIALS AND METHODS: Forty-seven patients with 65 liver masses < 3 cm in size (42 hepatocellular carcinomas, 11 hemangiomas, 12 metastatic tumors) were studied by 3DFT fast imaging with steady-state precession (FISP) MRI [TR(ms)/TE(ms)/flip angle (degree): 20/8/30]. The slab thickness was 21-35 mm, and there were seven partitions. The 3DFT-FISP MR images were obtained immediately after 0.1 mmol/kg of gadopentetate dimeglumine was administered intravenously over 2-3 s (early phase), 60 s after (late phase I), and 120 s after (late phase II). RESULTS: Eighty-six percent of small hepatocellular carcinomas showed hyperintense enhancement relative to the surrounding liver parenchyma and iso- or hypointense enhancement with or without capsular enhancement in the late phase. Eighty-two percent of small hemangiomas showed peripheral globular enhancement in the early phase and total hyperintense or peripheral enhancement in the late phases. Ninety-two percent of the small metastatic liver tumors showed doughnut-like ring enhancement in the early phase. CONCLUSION: By dynamic 3DFT-FISP MRI, we were able to accurately evaluate the hemodynamics and morphological findings of each type of small liver tumor.
We report a case of circumscribed intrapulmonary hematoma, in which MR findings were useful in establishing the diagnosis. It is usually easy to make a diagnosis of intrapulmonary hematoma using conventional methods, when clinical history of trauma and regression of the mass can be observed on serial radiography. However, in this case the mass remained almost unchanged 4 months after trauma on chest radiography and CT. Magnetic resonance revealed a hyperintense mass with an even higher signal rim on T1-weighted imaging and an irregular hyperintense mass on T2*-weighted imaging. We made a diagnosis of pulmonary hematoma based on these MR findings. Follow-up chest radiography and CT taken 1 year after the injury, revealed a substantial decrease in the size of the mass, which confirmed the diagnosis. As in this case, some intrapulmonary hematomas regress very slowly or may even increase in size, and diagnosis can be difficult with conventional methods. In such cases, MRI can be helpful.
An agar phantom with wide application in rf heating was developed. The phantom consists of 4 wt./wt. % agar powder, 0.1 wt./wt. % NaN3, 0-0.6 wt./wt. % NaCl, and 95.9-95.3 wt./wt. % water. The conductivity sigma (S/m) of the phantom was independent of frequency at 1-40 MHz, being sigma = 1.74 chi + 0.207 at 23.5 +/- 1 degrees C, where chi is the concentration of NaCl (wt./wt.%). The permittivity was nearly equal to 81 in the range of 5-40 MHz and 0-0.6 wt./wt.% of NaCl. The density and the heat capacity of the phantom were 1.02 X 10(3) kg/m3 and 1.00 kcal/kg degree C, respectively. The phantom had sufficient mechanical strength to permit construction of a torso 60 cm high. With the addition of a preservative, the phantom could be used for experiments on heating, without degeneration, for over one year.
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It has been suggested that fibronectin (FN) and syndecan play an important role in many aspects of cell-substrate interactions including cell adhesion. We hypothesized that oncofetal FN (onfFN) and syndecan play an important role in the process of adhesion of several human lung cancer cell lines. To test this, levels of onfFN in the culture supernatant were measured by an enzyme-linked immunosorbent assay in 18 human lung cancer cell lines. In addition, expressions of onfFN and syndecan-1 mRNA were analyzed by reverse transcriptase-polymerase chain reaction (RT-PCR). Of 18 lung cancer cell lines, 3 cell lines (all adenocarcinoma) released a significant amount of onfFN in culture supernatants. Of the 18 cell lines tested, 6 cell lines expressed a significant amount of mRNA for onfFN and 4 expressed a significant amount of mRNA for syndecan-1. Levels of onfFN and expressions of mRNA for onfFN and syndecan-1 were consistently higher in non-small cell lung cancer cell lines than in small cell lung cancer cell lines. In addition, cell lines that expressed mRNA for onfFN and syndecan-1 tended to adhere to culture dishes. Syndecan-1 expression was significantly higher in attached cells compared with nonattached cells within the same cell line. Differences in onfFN and syndecan synthesis may explain some in vitro and in vivo characteristics of lung cancer.
Three monoclonal antibodies (OR35, OR40 and OR48) against orosomucoid (ORM) were prepared for the phenotyping of the human ORM system. The OR35 and OR48 antibodies recognized ORM1 and ORM2 products, respectively. OR40 reacted strongly to the products of ORM1 but poorly to those of ORM2. With the help of these monoclonal antibodies, ORM phenotyping was performed on 658 individuals from nine subpopulations of aboriginal Taiwanese, with close attention to two individuals with an ORM1 Q0 homozygous phenotype. The ORM1*Q0 allele was found to be at a polymorphic frequency in eight of the nine subpopulations.
Fluid shear stress is one of the most important mechanical forces acting upon vascular endothelium, because of its location at the interface between the bloodstream and vascular wall. Recent evidence indicates that several intracellular signaling events are stimulated in endothelial cells in response to shear stress. Through these events, shear stress modulates endothelial cell function and vascular structure, but the molecular basis of shear stress mechanotransduction remains to be elucidated. In our research we have focused on three temporal signal responses to shear stress: (1) production of nitric oxide (NO) as an immediate response; (2) activation of extracellular-regulated kinases (ERK1/2; p44/p42 mitogen-activated protein (MAP) kinases) as a rapid response, and (3) tyrosine phosphorylation of focal adhesion kinase (FAK) as a sustained response. In terms of vessel biology, NO production, and ERK1/2 and FAK activation seem to be correlated with vascular homeostasis, gene expression and cytoskeletal rearrangement, respectively. In this review, we discuss the mechanisms that establish the temporal order of shear stress-stimulated responses based on a hierarchy for assembly of signal transduction molecules at the cell plasma membrane.
Expression of the c-erbB-2 oncogene protein was investigated by immunohistochemistry in 110 paraffin-embedded blocks of primary breast cancer. 25 (22.7%) of 110 tumors were stained positively with c-erbB-2 protein antibody. There was no correlation between c-erbB-2 immunostaining and age at diagnosis, menopausal status, hormone receptor status, tumor size, or clinical stage. The tumors with an extensive intraductal component showed a higher incidence of the c-erbB-2 expression than those without. A significantly shorter overall survival was obtained in patients with the expression of c-erbB-2 protein than in patients without. Staining of c-erbB-2 protein is an effective prognostic indicator in patients with breast cancer.
Among the angiotensin II (Ang II)-mediated signal events likely to be important in vascular smooth muscle cells (VSMCs) is activation of extracellular signal-regulated kinases 1 and 2 (ERK1/2). The upstream mediators by which Ang II activates ERK1/2 remain poorly defined. Recently, we showed that Ang II activated c-Src, a nonreceptor kinase, which is a candidate to mediate Ang II signal events. To determine whether c-Src is required for ERK1/2 activation by Ang II, we studied the effects of Src family-selective tyrosine kinase inhibitors on ERK1/2 activation and also studied Ang II-mediated signal events in Src-deficient and Src-overexpressing VSMCs. The tyrosine kinase inhibitors, genistein and CP-188,556, blocked Ang II-mediated ERK1/2 activation in rat VSMCs (rVSMCs). We derived Src-deficient VSMCs from the aortas of c-Src knockout mice (Src-/- mVSMCs). Basal ERK1/2 activity was lower, and activation of ERK1/2 by Ang II was significantly decreased in Src-/- mVSMCs compared with wild-type mVSMCs, whereas ERK1/2 protein expression and ERK1/2 activation by phorbol 12-myristate 13-acetate were similar. To examine the role of c-Src further, we overexpressed wild-type or dominant-negative c-Src in rVSMCs using retroviral vectors. ERK1/2 activation by Ang II was significantly increased in rVSMCs that overexpressed c-Src, whereas ERK1/2 activation by Ang II was significantly inhibited in rVSMCs that overexpressed dominant-negative c-Src compared with control rVSMCs. These findings demonstrate that c-Src activation is required for Ang II stimulation of ERK1/2 in VSMCs and suggest an important role for c-Src in Ang II-mediated signal transduction.