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Biomedical subjects

T Maeda

Publications and source records attributed to T Maeda.

At least 1,765 records · Page 98Linked to original sources
PubMedDate not supplied

Age-matched normal values and topographic maps for regional cerebral blood flow measurements by Xe-133 inhalation.

The relationship between normal aging and regional cerebral blood flow (rCBF) computed as initial slope index (ISI) by Fourier method was investigated in 105 right-handed healthy volunteers (132 measurements) by Xe-133 inhalation method, and age-matched normal values were calculated. Mean brain ISI values showed significant negative correlation with advancing age (r = 0.70, p less than 0.001), and the regression line and its 95% confidence interval was Y = -0.32 (X - 19) + 63.5 +/- 11.2 (19 less than or equal to X less than or equal to 80). Regional ISI values also showed significant negative correlations for the entire brain (p less than 0.001). The regional reductions of ISI values with advancing age were significantly greater in the regional distribution of the middle cerebral arteries bilaterally, compared with regions in the distribution of the other arteries (p less than 0.05). Therefore, measured rCBF values for patients must be compared to age-matched normal values for mean hemispheric and each region examined. Two kinds of topographic maps, brain map showing rCBF compared to age-matched normal values and showing hemispheric differences were made by dividing patient's values by the 95% confidence limits for age-matched normal values and displaying laterality index calculated as follows, respectively. (formula; see text) These maps were useful for evaluating significantly decreased or increased regions and regional hemispheric differences.

Adult↗
PubMedDate not supplied

Density of sympathetic nerve terminals in human superficial temporal arteries: potassium permanganate fixation and monoamine oxidase histochemistry.

The density of sympathetic nerve terminals in human superficial temporal arteries from 5 cases at intra- and extracranial bypass surgery was examined with two histochemical methods, one with potassium permanganate fixation and the other with the new monoamine oxidase staining technique. By potassium permanganate fixation, small cored vesicles containing fibers of noradrenergic nerve terminals made up 29.2% of all nerve fibers in the adventitia. The monoamine oxidase-containing nerves in the adventitia made up 31.4%. According to this study, sympathetic nerve terminal density in human superficial temporal arteries was assumed to consist of approximately 30% of all adventitial nerve terminals. In periadventitial nerve bundles, some unmyelinated axons contained monoamine oxidase activity. Thus, staining is considered to be useful in demonstrating the periadventitial and intervaricose fibers as well as the nerve terminals of sympathetic nerves in human cerebral arteries.

Fixatives↗
PubMedDate not supplied

Methylenetetrahydrofolate reductase C677T is not associated with expression of pyrimidine metabolic enzyme genes in colorectal cancer.

Methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism may influence the chemosensitivity of colorectal cancers to fluorouracil (5-FU) by increasing intracellular 5,10-methylenetetrahydrofolate. The effect of this polymorphism on the expression of thymidylate synthase (TS), dihydropyrimidine dehydrogenase (DPD), orotate phosphoribosyl transferase (OPRT) and thymidine phosphorylase (TP) in colorectal cancer was investigated. The MTHFR C677T polymorphism was analysed and TS, DPD, OPRT and TP mRNA expression was measured in tumour and adjacent normal mucosal tissue. In all patients, the genotypes of the tumour and normal tissues were identical. No differences were found in the expression of TS, DPD or TP mRNA by genotype in either tumour or normal tissue. Although the OPRT mRNA level in tumour tissue was not associated with the genotype, normal mucosa with the TT genotype showed a significantly higher OPRT mRNA level than mucosa with other genotypes. The MTHFR C667T polymorphism is not associated with intratumoural expression of TS, DPD, OPRT or TP.

Aged↗
PubMedDate not supplied

A case of calcitonin-producing parathyroid adenoma with primary hyperparathyroidism.

A 57-year-old female was admitted to our hospital with general lassitude, loss of appetite, nausea, upper abdominal pain, thirst, polydipsia and polyuria. On admission, she had an asymmetrical pear-shaped tumor in the right supraclavicular region and severe hypercalcemia. Plasma C-PTH was elevated to 22.72ng/ml. Plasma calcitonin was also elevated to 336 pg/ml. She died of respiratory and cardiac failure of two weeks after admission without any positive response to the treatment, including hemodialysis. Pathohistologically, the tumor was a parathyroid adenoma. The concentrations of C-PTH, intact PTH and calcitonin in the tumor tissue were markedly high: 4.56 micrograms/g wet, 13.9 ng/g wet and 50.7 ng/g wet, respectively. Immunohistologically, the tumor cells and the fibrous stroma were stained strongly positive to rabbit anti-human calcitonin antibody and rabbit anti-human N-PTH antibody by indirect immunoperoxidase staining. Calcitonin-producing tumors, except for medullary thyroid carcinoma are rarely reported. To our knowledge, this is the first report of such a calcitonin-producing parathyroid adenoma associated with primary hyperparathyroidism.

Adenoma↗
PubMedDate not supplied

Chronic myelomonocytic leukemia with polyneuropathy and IgA-paraprotein.

A 65-year-old woman had chronic myelomonocytic leukemia with peripheral neuropathy and IgA paraprotein with kappa type light chain. Plasma cells with "flaming" cytoplasma were seen in the bone marrow specimens. The findings suggest that chronic myelomonocytic leukemia may involve B-lymphocytes in the proliferative process and that it may be a clonal disease. Moreover, this case was associated with peripheral sensori-motor polyneuropathy. The disorder was responsive to prednisolone, as oral administration of prednisolone improved not only the peripheral polyneuropathy, but also the hematological findings. Serum vitamin B12 and lysozyme in the serum and urine were decreased by the steroid therapy. The administration of prednisolone is effective not only for polyneuropathy but also chronic myelomonocytic leukemia.

Bone Marrow↗
PubMedDate not supplied

Malignant peripheral nerve sheath tumor of the pancreas with perineurial cell differentiation.

The authors report a malignant peripheral nerve sheath tumor (MPNST) that developed in the body of the pancreas of a 76-year-old woman. The well-demarcated tumor, 4.5 x 3.5 cm in size, was composed of spindle-shaped cells arranged in a storiform pattern or sweeping fascicles. Ultrastructurally, the tumor cells had elongated cytoplasmic processes with numerous pinocytotic vesicles, and were covered with discontinuous basal lamina-like substances. Immunohistochemically, tumor cells were diffusely positive for epithelial membrane antigen, vimentin, and CD34, but negative for S-100 protein and Leu 7. It was therefore concluded that the tumor was a MPNST with perineurial cell differentiation. Primary MPNST of the pancreas is extremely rare and the immunohistochemical and ultrastructural studies are necessary for its diagnosis.

Aged↗
PubMedDate not supplied

Jejunal perforation in a patient with adult T-cell leukemia.

We present a case of adult T-cell leukemia (ATL) with jejunal perforation at the site of intestinal involvement by ATL. A 39-year-old woman presented with sudden-onset abdominal pain. Physical examination showed generalized severe abdominal tenderness and intraabdominal free air was seen on radiographic examination. Under a diagnosis of peritonitis due to intestinal perforation, an emergency operation was performed. A pinhole-like perforation was found in the jejunum 80 cm distal to Treitz's ligament, and the patient underwent partial resection of the affected jejunum. Microscopic examination revealed diffuse infiltration of abnormal lymphocytes into the entire wall of the jejunum and mesenteric lymph nodes. A diagnosis of ATL was confirmed by the presence of antibody to human T-lymphotropic virus type 1 (HTLV-1) in the serum, a positive result for T-cell markers and the HTLV-1 proviral genome in the mononuclear cells in the specimens. The final diagnosis was thus lymphoma subtype of ATL. Combination chemotherapy was repeated until the patient died 14 months postoperatively. Emergent surgery followed by intense chemotherapy might improve survival in patients with ATL and perforated intestine.

Adult↗
PubMedDate not supplied

A proposal of an off-line PACS based on a personal database.

Problems with picture archiving and communication systems (PACS) are focused and an off-line PACS of practical value is proposed in this paper. This system is based on the personal database where each patient has his/her own recording medium. This medium files all medical information as well as images of value, and is carried with a patient through hospital. Advantages over the conventional or on-line PACS communicating through a network are discussed and a possibility of practical use is analysed showing a prototype system. The biggest advantage of this system is quick and easy access to the images of concern and a small amount of cost for initial investment. It is also pointed out that the format of the data recording on the disk has to be standardized so that this system could be used for a medical care system over a wide area.

Computer Systems↗
PubMedDate not supplied

A case of biliary cystadenoma with obstructive jaundice.

Biliary cystadenoma is a rare cause of obstructive jaundice. We report a case of a 78-year-old Japanese man with biliary cystadenoma presenting repetitive abdominal pain and jaundice. Ultrasound sonography revealed a hyperechoic mass in the left lateral lobe of the liver. Histological examination revealed a biliary cystadenoma. Intracystic hemorrhage was assumed to be the cause of obstruction of the bile ducts.

Adenoma, Bile Duct↗
PubMedDate not supplied

Transformation-associated changes in gene expression of alternative splicing regulatory factors in mouse fibroblast cells.

Although the alternative splicing of various genes is a common phenomenon in tumorigenesis, little is known about the mechanism behind it. Recently, we found altered expression of splicing regulatory factors during two-step chemical transformation in vitro. However, it remains unknown whether such altered expression of splicing factors commonly occur during other modes of transformation. We have further investigated the expression of five splicing regulatory factors, heterogeneous nuclear ribonucleoprotein (hnRNP) A1 and A2, alternative splicing factor/splicing factor 2 (ASF/SF2), spliceosome component of 35-kDa protein (SC35) and 65-kDa subunit of U2 snRNP auxiliary factor (U2AF65), using two series of clonally-derived mouse fibroblast cell lines, that were SV40 large T transfectants (SV-T2 and NIH3T3/13C7) or c-erbB2 transfectants (A4). U2AF65 expression was increased (2.1- and 2.7-fold) in NIH3T3/13C7 and A4 compared with the normal parental cells, respectively, and SC35 expression was increased 1.8- to 2.3-fold in all transformed cells. These results suggest that altered expression of some splicing regulatory factors may commonly occur during various modes of cellular transformation.

Animals↗
PubMedDate not supplied

Cell proliferation and cell loss in nodule-in-nodule hepatocellular carcinoma.

BACKGROUND/AIMS: In order to clarify the significance of the balance between cell proliferation and cell loss during the progression of hepatocellular carcinoma, 16 operative specimens of nodule-in-nodule hepatocellular carcinoma were investigated. METHODOLOGY: In 16 specimens, cell proliferation was evaluated by the expression of Ki-67 nuclear antigen, and cell loss was also examined by the method of terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL). The expressions of p53 protein, bcl-2 protein and Fas antigen were also investigated to clarify the relationship between their expression and cell kinetics. RESULTS: The Ki-67 labeling index of the inner nodules was higher than that for the outer nodules (18.9% vs. 7.2%; p < 0.05) and the TUNEL labeling index of the inner nodules was also higher than that for the outer nodules (12.8% vs. 6.6%; p < 0.05). The increasing rate of the Ki-67 labeling index from Edmondson's grade I to II was 3.9 +/- 3.0, that from grade II to III was 3.9 +/- 2.4, while the increasing rate of the TUNEL labeling index from grade I to II was 2.7 +/- 0.3 and that from grade II to III was 1.7 +/- 0.2 (p < 0.05). p53 Protein was observed in 5 cases, while bcl-2 protein was found in 4 cases in the border area of the inner nodule. However, Fas antigen was found in none of the examined cases. Regarding the Ki-67 positive rate in the inner nodule, the Ki-67 positive rate in the p53 protein positive cases was significantly higher than that in the negative cases (30.3 +/- 15.4 vs. 11.9 +/- 9.2; p < 0.05). However, the TUNEL labeling index was not affected by the expression of those proteins. CONCLUSIONS: This study suggested that tumor progression depends on a disturbance in the cell kinetic balance caused not by a decrease in the absolute amount of cell loss but in the chaotic balance between cell loss and cell proliferation.

Apoptosis↗
PubMedDate not supplied

A case of fallopian tube carcinoma: successful preoperative diagnosis with MR imaging.

We report a case of fallopian tube carcinoma, successfully diagnosed preoperatively. The patient was a 64-year-old woman. Transvaginal sonography and computed tomography showed a cystic and solid tumor on the left side of the uterus, suggesting ovarian cancer. The tumor was, however, suspected to be a fallopian tube carcinoma on MR imaging. MR images showed a solid mass surrounded by a tube-shaped cystic part. At surgery, a solid and cystic tumor was found in the left fallopian tube. MR imaging may be useful to assist in the diagnosis of fallopian tube carcinoma.

Cystadenocarcinoma, Papillary↗
PubMedDate not supplied

Physiologically defined VIM nucleus. Its special reference to control of tremor.

In the course of stereotactic surgery for some 100 parkinsonian patients, correlative study of recording and stimulation has been done in and around the thalamic nucleus ventralis intermedius (VIM) under local anesthesia. The VIM nucleus is roughly identified either by the increase of neural noise level or radiological measurement. More accurately, in the thus identified VIM, sensory neurons related to kinesthetic sense of the contralateral extremity were found in about half of the cases. Electrical stimulation of this point at threshold intensity produced paresthesia on the contralateral area around its receptive field. With increased stimulus intensity, increment of grouping discharge in EMG of that part was pertinent in the majority of cases. A small localized lesion at such a thalamic point was shown to be quite effective for alleviation of tremor without any neurological, especially sensory, deficit.

Brain Mapping↗
PubMedDate not supplied

Clinicopathological characteristics of surgically resected minute hepatocellular carcinomas.

BACKGROUND/AIMS: The multistep development of overt hepatocellular carcinoma from very well-differentiated early hepatocellular carcinoma, and of early hepatocellular carcinoma from adenomatous hyperplasia has been strongly suggested. The clinicopathologic and immunohistochemical characteristics of solitary minute hepatocellular carcinomas smaller than 1 cm in size have yet to be clarified. METHODOLOGY: Fourteen minute hepatocellular carcinomas were divided into 2 groups consisting of: 1) hepatocellular carcinoma of hepatitis B surface antigen positive patients (B-HCC) (n = 5), and 2) hepatocellular carcinoma of hepatitis C virus antibody positive patients (C-HCC) (n = 9), then they were all analyzed histopathologically and clinicopathologically. Immunohistochemical studies were also performed using the antibodies against p53 protein. RESULTS: Six of the 14 minute hepatocellular carcinoma were demonstrated to be moderately or poorly differentiated tumors. Among the 8 well-differentiated minute hepatocellular carcinomas, 2 tumors already contained less differentiated components. B-HCC tended to be less differentiated than C-HCC (P < 0.05). Adenomatous hyperplasia was detected in only 2 cases of C-HCC. Small cell liver dysplasia was detected significantly more frequently in C-HCC than in B-HCC (P < 0.05). The prognosis of the 14 minute hepatocellular carcinomas varied considerably. Immunohistochemically, some tumor cells were positive for p53 in 3 cases. CONCLUSIONS: Our study suggests that 1) the multistep carcinogenesis through adenomatous hyperplasia may not be so frequent, 2) De novo carcinogenesis from not only well-differentiated hepatocellular carcinoma, but also from less differentiated hepatocellular carcinoma, especially B-HCC, may be present, 3) the carcinogenesis in the B-HCC cases may behave differently from that in C-HCC cases, and 4) minute hepatocellular carcinomas demonstrate varying prognoses after hepatectomy.

Adult↗
PubMedDate not supplied

Radiosensitivity of human breast cancer cells transduced with wild-type p53 gene is influenced by the p53 status of parental cells.

Induction of apoptosis with chemotherapeutic agents or radiation in tumours is frequently related to the status of those p53 gene of the tumours. To examine whether forced expression of the wild-type p53 gene in tumour cells can modulate their susceptibility to radiation and anti-cancer agents, we retrovirally transduced two types of human breast cancer cell lines, which respectively harboured a mutated p53 gene (OCUB-M) or wild-type p53 gene (YMB-1), with the wild-type p53 gene. Transduced cells which consistently expressed the wild-type p53 gene (OCUB-M/p53, YMB-1/p53) proliferated at the same rate as control cells which were transduced with the beta-galactosidase gene (OCUB-M/lacz, YMB-1/lacz). However, sensitivity to radiation was increased in OCUB-M/p53 cells but not in YMB-1/p53 cells. In vitro chemosensitivity to DNA-damaging anticancer agents such as cyclophosphamide and 5-fluorouracil was not influenced by the transduction of the wild-type p53 gene in either cells. Expression of the wild-type p53 gene in p53-mutated human breast cancer cells can therefore increase their sensitivity to radiation but not their chemosensitivity. Therapeutic effects following by the transduction of the wild-type p53 gene were not observed in breast cancer cells already bearing the wild-type p53 gene.

Antineoplastic Agents↗