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Y Uesugi

Publications and source records attributed to Y Uesugi.

At least 37 records · Page 2Linked to original sources
PubMed1996

[Three-phase dynamic helical CT for hepatocellular carcinoma: optimal scanning protocol].

To assess the optimal scanning protocol for three-phase dynamic helical CT, 20 patients were examined according to the following 4 methods (5 cases each) : (1) 100 ml Iopamidol (300 mgI/ml), at a rate of 2 ml/sec ; (2) 120 ml,3 ml/sec, (3) 150 ml, 3 ml/sec ; (4) biphasic method, initial 100 ml, 3.3 ml/sec ; remaining 50 ml, 1.6 ml/sec. Assessment of the time-density curve of the aorta, and the liver parenchyma, indicated that protocol (4) was superior to the others. Using protocol (4), 32 patients (62 nodules) with hepatocellular carcinoma underwent three-phase scanning, consisting of early, late, and delayed phases. Out of 61 nodules, 43 nodules were detected as high density areas in the early phase, 7 nodules as low density areas only in the late phase, and 3 nodules as low density areas only in the delayed phase. Compared with MRI, three-phase dynamic helical CT demonstrated numerous nodules, especially those less than 10 mm in diameter, and, therefore, was useful for the detection of hepatocellular carcinoma.

Aged↗
PubMed1996

[Three-dimensional CT angiography of the portal vein using multiple threshold display].

To evaluate the usefulness of three-dimensional (3D) CT angiography of the portal vein obtained by using a multiple threshold display, 3D reconstructions were performed in 15 patients. The CT scanner employed was the Toshiba Xvigor. A volume of 150 ml of lopamidol 300 mg1/ml was administered at 3.3 ml/sec intravenously. Portal venous phase helical scanning was initiated 80 seconds after the start of the injection. Helical CT data were acquired using up to 25 continuous 1.0-sec rotations during a single breath-hold with an X-ray beam width of 7 mm and a couchtop movement speed of 7 mm/sec. Axial images were reconstructed at a section interval of 3 mm. Both the shaded surface display (SSD) and multiple threshold display (MTD) were generated by using Xtension with Sparc20. MTD was performed as follows. First, voxels, with higher CT values than that of liver parenchyma, were selected. Then, selected voxels were divided into eight parts, which were each assigned gradations of white to grey. The highest part of selected voxels, with higher CT values than that of the second branch of the portal vein, were set to white and a transparency of 0%. The other seven parts were each assigned transparencies of more than 0%. MTD images were compared with SSD in 15 cases by two radiologists. MTD images were superior to SSD images in quality, because MTD diminished surrounding artifacts due to liver parenchyma and enabled small vessels to be depicted clearly. Based on the above results, it was considered that MTD was a useful method for 3D CT angiography using enhanced helical CT.

Fatty Liver↗
PubMed1995

[Essential thrombocythemia in transformation to smouldering megakaryoblastic leukemia with myelofibrosis].

Leukemic transformation in essential thrombocythemia (ET) is rare. We describe a patient with ET which transformed to megakaryoblastic leukemia with myelofibrosis after treatment with melphalan for 8 years. His course after transformation smouldered for 20 months without antileukemic chemotherapy. A 61-year-old man was referred by a local doctor to Niigata University Hospital due to nasal bleeding in June 1984. Complete blood count (CBC) was as follows; hemoglobin 12.4 g/dl, platelets 268.8 x 10(4)/microliters, and white blood cells 11,900/microliters, with differentials of 39% PMN, 1% basophils, 2% eosinophils, 4% monocytes, and 13% lymphocytes. Bone marrow examination revealed hyperplasia of megakaryocytes without increase of reticulin fibers. Neutrophil alkaline phosphatase activity and karyotype of marrow cells were normal. ET was diagnosed. He was followed up by local doctor. The platelet count was controlled at a level of approximately 40 x 10(4)/microliters with melphalan for eight years. In January 1992 he developed pain in his lower extremities. He was admitted to our hospital on May 29, 1992. CBC was as follows; hemoglobin 8.9 g/dl, platelets 14.3 x 10(4)/microliters, and white blood cells 3,500/microliters, with differentials of 25% PMN, 5% monocytes, 28% lymphocytes, and 24% blasts. Bone marrow aspiration was unsuccessful and bone marrow biopsy revealed increases in fibroblasts and collagen fibers. Circulating blasts were positive for CD4, CD7, CD25, CD13, CD33, CD34, and HLA-DR and partly positive for CD41 and CD36. In ultrastructural cytochemistry blasts were positive for platelet peroxidase but negative for myeloperoxidase. Cytogenetic study revealed 46, XY, +der (1) t(1:7) (p11;q11) in all of five metaphases. He was diagnosed with megakaryoblastic leukemia accompanied by myelofibrosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1995

[Familial posterior cortical atrophy with visual agnosia and Bálint's syndrome].

We report a patient of posterior cortical atrophy with progressive visual agnosia, Bálint's syndrome and dementia in which posterior cortical atrophy with similar characteristics on CT and progressive dementia were found in a sister. The patient was a 75-year-old woman who noted the onset of a progressive visual disorder at the age of 70, and whose family first noticed disoriented behavior at around the same period. Ophthalmologic examinations revealed mild cataract but no evidence of peripheral optic nerve or retinal lesions. Neuropsychological examination showed right homonymous hemianopia, visual agnosia, Bálint's syndrome, mild transcortical sensory aphasia, Gerstmann's syndrome, constructional apraxia, mild ideomotor apraxia and memory disorder. MRI showed marked dilatation of both lateral ventricles, especially the posterior horns, and severe atrophy of the occipital lobes, hippocampus, and the parahippocampal gyrus. Assessment of regional cerebral blood flow by IMP-SPECT revealed a generalized decrease in the temporo-parieto-occipital region bilaterally. The patient's sister began to show evidence of progressive dementia at 80 years of age and CT of the brain revealed marked atrophy, predominantly in the occipital lobes, similar to that of the patient. We believe this to be the first report of posterior cortical atrophy with a positive family history, suggesting the possibility of a hereditary syndrome.

Aged↗
PubMed1995

[Three-dimensional helical CT angiography of the abdomen].

To evaluate the quality of three-dimensional (3D) images of the abdominal vasculature acquired using enhanced helical CT, 3D reconstructions were performed for 43 examinations (38 patients). Twenty-one of 43 examinations were also reconstructed by Maximum Intensity Projection (MIP). The CT scanner employed was the Toshiba Xforce. Helical CT data were acquired using up to 20 continuous 1.5-sec rotations with an X-ray beam width of 5 mm and a couchtop movement speed of 5 to 10 mm/1.5 sec. Axial images were reconstructed at a section interval of 2 mm. Optimal protocol on enhanced helical CT was as follows: Iopamidol 300 mg I/ml was administered intravenously using a biphasic technique (3-4 ml/sec for the initial 100 ml, followed by 0.7-1.5 ml for the remaining 50 ml), and delay times of the early and late phases were 25-35 and 90 sec, respectively. Aortic branches were clearly demonstrated on early phase, while portal branches were well defined on late phase. In the visualization of abdominal vessels, 3D images were nearly equal to MIP images. However, for anteroposterior images, MIP images were superior to 3D images in quality, because 3D images had some longitudinal direction artifacts. Three-dimensional images were considered to be useful for correctly evaluating overlapping abdominal vasculatures. From the above results, 3D and MIP images of the abdominal vasculature obtained using enhanced helical CT were considered to compensate for each other.

Abdomen↗
PubMed1994

[Three-dimensional CT imaging of pulmonary nodules using helical scan CT].

To evaluate the usefulness of three-dimensional (3D) imaging of pulmonary nodules from helical scan CT images, 3D reconstructions were performed in 23 patients, using a CEMAX VIPstation. These cases included 15 lung cancers, six metastatic lung cancers, an aspergilloma and a tuberculoma. The equipment used was a Toshiba CT system, the X force. Helical scan CT data were acquired using up to 20 continuous 1.5 sec rotations with an X-ray beam width of 5 mm and a couchtop movement speed of 5 mm/1.5 sec, and during a single breath-hold. Axial images were reconstructed at a section interval of 2 mm. Helical scan CT permits axial images to be reconstructed at any desired position within the scanned area, and provides images without interslice gaps caused by respiratory movement. Therefore, high-quality 3D images can be obtained from these data. Concerning the optimum threshold range of CT number of 3D reconstruction, we clarified the lower and upper limits (lower/upper), as follows: 1) Solid pulmonary nodule: (-700-(-)400/-100 HU) 2) Tumor invaded to pleura or chest wall: (-700-(-)400/-200 HU) 3) Pulmonary nodule with cavity: (-700-(-)400/50 HU) 4) Small pulmonary nodule (< 10 mm): (-750-(-)600/-100 HU) In all cases, it was possible not only to demonstrate abnormal findings three-dimensionally, but also to grasp anatomical relationships among the pulmonary nodule, bronchi, vessels and chest wall. In conclusion, it was considered that 3D CT imaging provided additional anatomical information and was very useful.

Adenocarcinoma↗
PubMed1994

[MR imaging findings in patients with epilepsy].

We retrospectively examined the MR imaging (MRI) findings in 144 patients with epilepsy (31 with temporal lobe epilepsy and 113 with other epilepsies). 110 cases (76.4%) showed abnormal findings such as spotty lesions in white matter, hippocampal atrophy and/or signal change, ventricular dilatation and/or deformity, developmental lesions, brain tumors and so on. Hippocampal atrophy and/or signal change was shown in 74.1% of temporal lobe epilepsy, a remarkably high percentage (P < 0.01) compared with the other types of epilepsies (18.1%). This finding means that hippocampal lesions may play a large part in the cause of temporal lobe epilepsy. Investigation of the relationship between clinical term and abnormal findings revealed that the longer the clinical term, the larger the number of hippocampal lesions, regardless of whether it is temporal lobe epilepsy or not. Thus hippocampal lesions may occur as a result of hypoxia accompanied with seizure. Therefore we recommend horizontal and/or vertical sections of hippocampus in MR imaging of all patients with epilepsy. Even though MR findings may reflect some secondary lesions, MRI will shed some light on the proper understanding of epilepsy.

Adolescent↗
PubMed1994

Mechanism for macrophage activation against Corynebacterium parvum--participation of T cells and its lymphokines.

It is well known that Corynebacterium parvum activates macrophages to produce tumor necrosis factor (TNF). It is suspected that the activation of macrophages by C. parvum requires T-cell participation. The purpose of this study was to confirm that T cells participate in the activation of macrophages by C. parvum. TNF production in vitro from the spleen cells of BALB/c(-)+/+ mice was abrogated completely by the pre-treatment of spleen cells with anti-Ia antiserum and complement, indicating that Ia+ cells are the source of TNF. TNF production was not elicited at all in BALB/c-nu/nu mice. However, there was an increase in the number of Ia+ cells as well as an increase in the weight of spleen and liver. Supernatant from a culture of spleen cells stimulated with phytohemagglutinin-P (a PHA-induced lymphokine) made it possible for BALB/c-nu/nu mice to produce TNF, associated with an induction of Lyt-1+ cells and Lyt-2+ cells. However, treatment with the lymphokine did not augment the increases of Ia+ cells or liver and spleen weights. These results suggest that increasing the number of Ia+ cells is not sufficient to bring about TNF production; Ia+ cells must also be stimulated by T cells or T-cell lymphokines in order to produce TNF. These results suggest that T cells play an essential role in the activation of Ia+ cells against C. parvum.

Animals↗
PubMed1993

[Clinical evaluation of two- and three-dimensional imaging of helical scanning CT in the upper abdomen].

To evaluate the usefulness of helical scanning CT of the upper abdomen, 30 patients with hepatic, adrenal, pancreatic and renal disease were examined using a Toshiba CT system, the Xforce. Helical scanning CT data were acquired using up to 20 continuous 1.5-second rotations, with a 1.5-3 ml bolus injection of contrast medium, and during a single breath-hold. Helical scanning provided both better data continuity and resolution than conventional scanning. The axial images with a slice thickness of 5 mm were not inferior in quality to equivalent images acquired by conventional CT, and multiplanar reconstruction images were superior. Targeted structures could be easily obtained because helical scanning CT permits image reconstruction in any direction. Using a CEMAX-VIPstation, we generated three-dimensional display images of high-density structures from the postcontrast data acquired with helical scanning. On these images, it was easy to observe the high-density tumors three-dimensionally and to determine the position of the tumors relative to the high-density surrounding organs. In conclusion, helical scanning CT was considered to be useful in clinical diagnosis involving the upper abdomen.

Adult↗
PubMed1993

Morphometric analysis of the pelvis in mice treated neonatally with tamoxifen.

The pelves of male and female C57BL/Tw mice given five daily injection of 100 micrograms tamoxifen, 50 micrograms dihydrotestosterone (DHT), or 2 micrograms diethylstilbestrol (DES) from the day of birth were examined morphometrically and histomorphometrically. Total areas of the pelvis, ilium, ischium, and pubis were significantly smaller in neonatally tamoxifen-treated mice than in the controls. There was no significant difference in length of the ischium between tamoxifen-treated and control mice of both sexes. However, lengths of ilium and pubis, and widths of ilium, pubis, and ischium in tamoxifen-treated male and female mice were significantly smaller than in the respective controls. In contrast, neonatal treatment with DHT or DES did not affect the shape of the pelvis of either sex. In the neonatally tamoxifen-treated females, the number of osteoblasts and osteoclasts per 200 microns trabecular surface length and per 10,000 microns2 subperiosteal area of pubic bone section was smaller than in the controls. Inhibition of ossification persisted in the junction of the pubis and ischium of pelves treated with tamoxifen in vitro. These results suggest that neonatally administered tamoxifen mainly retards the growth of the ilium and pubis in mice by changing the activities of osteoclasts and osteoblasts, and that tamoxifen acts directly on the neonatal mouse pubis to inhibit its ossification.

Animals↗
PubMed1993

[Peripheral neuropathy in large granular lymphocytic leukemia].

A 16-year old woman with LGL leukemia developed peripheral neuropathy. She showed virus-associated hemophagocytic syndrome (VAHS)-like signs including high fever, liver dysfunction, huge splenomegaly, hepatomegaly and pancytopenia. The presence of chronic active EB virus infection was proved by marked high titers for IgG and IgA antibodies to the Epstein-Barr viral capsid and early antigens and low titers of antibody to Epstein-Barr nuclear antigens. She showed dysesthesia and paresthesia of bilateral lower extremities with marked swelling and tenderness, and later developed muscular weakness and atrophy with areflexia of lower extremities. Findings of the central nervous system dysfunction were not observed except for the acceleration of jaw jerk. Pleocytosis and increased protein levels in the cerebrospinal fluid were found. Pulse therapy of methyl-prednisolone and high dose intravenous immunoglobulin therapy (20 g/day for 3 days) were effective for neurological findings. The increased neopterin in the cerebrospinal fluid suggested that peripheral neuropathy was caused by activated macrophages.

Adolescent↗
PubMed1992

Comparative study of sexual dimorphism of the innominate bone in rodents and amphibians.

Sexual dimorphism in the shape of the innominate bone was demonstrated in the rat, mouse, Chinese hamster (Cricetulus griseus), frog (Ranna nigromaculata), and newt (Cynops pyrrhogaster) with a computer-assisted morphometric technique. In the rat, mouse, and hamster, ratios of ischium and pubis widths to the innominate bone length (INL) were larger in the males than in the females; however, the ratio of pubis length to INL was larger in the females than in the males. In the frog, the ratio of distance between the upper edge of the acetabulum and the lower edge of the pubis to INL was larger in males than in females. In the newt, ratios of width of ischiopubis and the longitudinal length of the ischiopubis to INL were larger in females than in males.

Animals↗
PubMed1992

Effects of sex steroids on the development of sexual dimorphism in mouse innominate bone.

The sexual dimorphism of the innominate bone was examined in 14 strains of mice. In female mice of all strains, the pubis was significantly longer and thinner than that in the strain-matched males. In 13 of 14 strains, the ischium in the male was longer and thicker than in the female. In the testicular-feminized male (Tfm) mouse, the ischium was longer and thinner than that in the wild-type male, resembling that of the wild-type female. The pubis of the Tfm mouse was longer than in the wild-type males. The pubis width in the Tfm mouse was between those of the wild-type male and female. Gonadectomy at ages of 5, 10, 20, 30, and 60 days in both sexes showed that the ischium develops as the female type when sex hormones are absent. In contrast, postnatal testicular androgen induces the male-type ischium. Gonadectomy at 60 days had a slight effect on the pubis, indicating that sexual dimorphism of the pubis was determined before 60 days of age. Estrogen receptors (ER) were immunohistochemically demonstrated in bone cells of 0- to 60-day-old mice. ER was found exclusively in the periosteum of the pubis at the day of birth; however, it appeared in bone cells of all parts of pelvis at 10-60 days. These results indicate that sexual dimorphism of the pubis is consistent for the 14 mouse strains examined, and that the shape of the pubis is determined by sex steroids before 60 days of age. Since ER exist in the bone cells, morphogenesis of the pelvis may be regulated by these sex steroids.

Animals↗
PubMed1991

Bleomycin-induced pulmonary fibrosis in genetically mast cell-deficient WBB6F1-W/Wv mice and mechanism of the suppressive effect of tranilast, an antiallergic drug inhibiting mediator release from mast cells, on fibrosis.

It has been well known that the number of mast cells increases during the development of fibrosis in various tissues including the lung. However, the role of mast cells in fibrosis still remains obscure. In the present paper, we evidenced that pulmonary fibrosis could be induced in genetically mast cell-deficient WBB6F1-W/Wv mice as well as WBB6F1-(+/+) mice having mast cells normally by the treatment with bleomycin (BLM, 5 mg/kg, i.v., 10 days), and there was not much difference in the histological changes of lungs between the two strains. An increase in the hydroxyproline content of the lung of WBB6F1-W/Wv mice was rather higher than that of WBB6F1-(+/+) mice. Previously, we reported that tranilast, an antiallergic drug inhibiting chemical mediator release from mast cells, suppressed the development of BLM-induced pulmonary fibrosis in ICR mice, suggesting the possibility that mast cells play certain roles in fibrosis. However, it was evidenced in the present report that tranilast suppressed BLM-induced fibrosis in WBB6F1-W/Wv mice. Tranilast neither suppressed the cytotoxic activity of BLM against KB cells and L-929 cells in vitro, nor inhibited the antitumor activity of BLM against Sarcoma-180 transplanted subcutaneously into ICR mice. Tranilast may act through suppressing BLM-induced activation of lymphoid cells including macrophage and neutrophil. These results indicate an inconsequential role of mast cells in the development of fibrosis. Increases in the number of mast cells and in histamine content of the lung, which were widely reported in the lungs of BLM-treated mice, may be the result of fibrosis.

Analysis of Variance↗