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Biomedical subjects

S Sanada

Publications and source records attributed to S Sanada.

At least 55 records · Page 3Linked to original sources
PubMed1991

Direct comparison of conventional and computed radiography with a dual-image recording technique.

To compare the image quality of computed radiographic (CR) with conventional screen-film images, the authors used a dual-image recording technique. Images were simultaneously acquired with a conventional screen-film combination and a storage-phosphor imaging plate loaded into a single cassette. Wiener spectra and modulation transfer function were compared for both image types. A preliminary observer performance test was conducted with chest images obtained with the dual-image recording technique on portable and fixed equipment. Analysis of physical parameters and observer test results suggests that the conventional screen-film system can provide slightly superior image quality, although the CR system has some advantage in bedside applications.

Confidence Intervals↗
PubMed1991

Data compression: effect on diagnostic accuracy in digital chest radiography.

High-resolution digital images make up very large data sets that are relatively slow to transmit and expensive to store. Data compression techniques are being developed to address this problem, but significant image deterioration can occur at high compression ratios. In this study, the authors evaluated a form of adaptive block cosine transform coding, a new compression technique that allows considerable compression of digital radiographs with minimal degradation of image quality. To determine the effect of data compression on diagnostic accuracy, observer tests were performed with 60 digitized chest radiographs (2,048 x 2,048 matrix, 1,024 shades of gray) containing subtle examples of pneumothorax, interstitial infiltrate, nodules, and bone lesions. Radiographs with no compression, with 25:1 compression, and with 50:1 compression ratios were presented in randomized order to 12 radiologists. The results suggest that, with this compression scheme, compression ratios as high as 25:1 may be acceptable for primary diagnosis in chest radiology.

Humans↗
PubMed1990

Mechanism of gallium 67 accumulation in inflammatory tissue.

The present study was undertaken to elucidate the accumulation mechanism of gallium 67 in inflammatory tissue. 67Ga accumulation in inflammatory tissue was observed by macro- and microautoradiogram. Permeability indices were calculated for serum albumin from blood vessels into inflammatory and normal tissue. Neutrophils and macrophages did not play a major role in 67Ga accumulation in the inflammatory tissue because 67Ga could hardly be detected in the sites in which neutrophils were crowded; the accumulation was concentrated in the intercellular space around these cells in the tissue. Permeability indices for inflammatory tissue were much greater than those for normal tissues. It is thought from the present study and previously reported results that 67Ga, together with plasma from permeable blood vessels, readily penetrates the inflammatory tissue and stays there by binding to the acid mucopolysaccharide present in the tissue.

Animals↗
PubMed1990

[Hematuria: an initial sign of cecal carcinoma].

A 79-year-old female was seen with hematuria, cystoscopy showed a non-papillary, broad-based tumor arising from the right anterolateral wall of the bladder. Transurethral biopsy revealed adenocarcinoma. Pelvic CT scanning revealed that the tumor extended from the bladder wall to the wall of the ileo-caecal intestine. Gastrointestinal series revealed no abnormal findings although the cecum could not be visualized clearly, and we could not distinguish whether the primary site was the bladder or intestine. Surgical exploration was performed. The main tumor seemed to arise from the cecum, extended downward and invaded the bladder wall. Right hemicolectomy and en bloc partial cystectomy were performed. The final diagnosis was adenocarcinoma of the cecum invading the bladder. We could find no reports on adenocarcinoma of the cecum in which hematuria was the initial symptom, as in this case, in Japan.

Adenocarcinoma↗
PubMed1988

Biodistributions of radioactive alkaline metals in tumor bearing animals: comparison with 201Tl.

The retention values for 42K, 86Rb and 134Cs in the tissues and blood were quite similar to those for 201Tl, but were very different from those for 22Na. In an experiment for subcellular fractionation of tumors, most of these nuclides were localized in the supernatant fraction, with small amounts in other fractions. The concentration ratios for these nuclides in each fraction were approximately constant regardless of the time after administration. Radioactive alkaline metals in the supernatant fraction of the tumor homogenate existed mostly as free ions and were bound to protein in other fractions of tumor tissue. These results were essentially the same as those for 201Tl. Ouabain suppression studies indicated that 201Tl is taken up into the tumor cells partly through Na+, K+-ATPase of their membranes. Ionic radii of alkaline metals and thallium were related to their blood and tumor retention values. This relationship suggested that monovalent cations whose ionic radii exceed 0.133 nm, and which exist as free ions in the tissue fluids, behave like the potassium ion. Potassium and K analogs (Tl, Rb, Cs) are avidly taken up into viable tumor cells whose Na+, K+-ATPase activity is elevated. Therefore, suitable radionuclides of K and K analogs can be excellent agents for visualization of viable tumor tissues.

Animals↗
PubMed1988

Distribution of 67Ga-citrate in abscess-induced rat by quantitative whole body autoradiography.

Distribution of 67Ga-citrate in inflammatory tissues was determined, and correlation between the 67Ga-uptake and capillary permeability of plasma from blood vessels in the inflammatory tissue was elucidated, by quantitative whole body autoradiography and double tracer autoradiography. The distribution of 67Ga in inflammatory tissue was similar to that of 131I-HSA and 99mTc-HSA, which were applied as an index to the plasma element. These results showed that the capillary permeability of plasma from blood vessels in the inflammatory tissue increases, and this causes the 67Ga-uptake.

Abscess↗
PubMed1988

[Long-term effects of human seminal plasma from whole semen and from different fractions of split ejaculate on motility of human ejaculated spermatozoa].

A number of studies have implied that seminal plasma contains one or more factors that stimulate spermatozoal motility. On the other hand, many authors have shown that continuous, long term exposure to seminal plasma is detrimental to motility and survival of spermatozoa. In this study we examined the long term effects of human seminal plasma not only from whole semen but also from different fractions of split ejaculate on motility of human ejaculated spermatozoa. Washed spermatozoa were incubated in modified BWW medium containing human serum albumin with or without seminal plasma. A considerable percentage of spermatozoa maintained good progressive motility for up to 20 h. when free from seminal plasma. Addition of seminal plasma (20%, v/v) obviously depressed the motility, particularly progressive motility. The most depressive effect occurred in the first (prostatic) fraction of split ejaculate, and the effect of the last (vesicular) fraction was less harmful. These observations suggest that seminal plasma has (a) factor(s) that impair the maintenance of spermatozoal motility which originate possibly from the prostate or epididymis, since both fluids of these accessory organs appear to be secreted mainly into the first portion ejaculate.

Ejaculation↗
PubMed1988

[Two cases of adrenal myelolipoma].

Myelolipoma of the adrenal gland is a benign oligosymptomatic tumor composed of various proportions of fat and bone marrow elements. We report two operated cases found incidentally in a 76-year-old man and 49-year-old man.

Adrenal Gland Neoplasms↗
PubMed1987

Biodistributions of 201Tl in tumor bearing animals and inflammatory lesion induced animals.

The accumulation of 201Tl in tumor and inflammatory tissues were small. However, this nuclide showed a high concentration in viable tumor tissue, less in connective tissue (containing inflammatory tissue), and was not seen in necrotic tumor tissue regardless of the time after administration of 201Tl(I)-chloride. In inflammatory lesions, 201Tl accumulated in subcutaneous tissue infiltrated with neutrophils and macrophages, and quite large amounts of this nuclide were accumulated in subcutaneous tissue and sites where neutrophils were crowded. Most 201Tl existed in a free form in the fluid of tumor and inflammatory tissues regardless of the time after administration. A small amount of this nuclide was localized in the nuclear, mitochondrial and microsomal fractions in these tissues, and the nuclide was bound to protein in these fractions. The distribution of 201Tl(III)-chloride in tumor bearing animals was essentially the same as that of 201Tl(I)-chloride.

Animals↗
PubMed1987

[Beneficial effect of zinc supplementation on pruritus in hemodialysis patients with special reference to changes in serum histamine levels].

Persistent pruritus is one of the most common symptoms in hemodialysis patients. The cause of pruritus is not known, and conventional treatment for pruritus is rarely helpful. Some authors thought that release of histamine from increased mast cells in uremic patients was the cause of pruritus. On the other hand, there have been a number of reports suggesting that uremic patients are zinc deficient. In vitro as well as in vivo studies have demonstrated that zinc has an inhibitory effect on various functions of some cells, such as histamine release from mast cells. In this study, we examined the serum zinc and histamine levels in 19 hemodialysis patients with persistent pruritus and the effect of zinc supplementation on the pruritus. In patients with pruritus, the serum zinc level decreased and serum histamine level increased, showing a negative correlation between them. Oral zinc sulfate, 445 mg daily for two months, relieved pruritus subjectively in 53% of the patients. After treatment, serum histamine levels decreased significantly, as well as serum zinc levels increased significantly. These findings suggest that zinc deficiency participates in increased histamine levels in dialysis patients, and subsequently in the development of uremic pruritus.

Administration, Oral↗
PubMed1986

A single-strip mini-paper chromatographic method for rapid purity-control of 99mTc-labeled radiopharmaceuticals.

A single-strip miniaturized paper chromatographic method (Mini-PC) was developed using 80%-90% acetone solvent for rapid purity-control of 99mTc-radiopharmaceuticals. Routine 99mTc-radiopharmaceuticals (eight kinds of "kit" made agents) and diluted agents (in which radiochemical impurities might be formed) were analyzed by Mini-PC and other methods. This showed that, compared with the other methods, the Mini-PC technique is useful for the simple and rapid routine analysis of radiochemical impurities of "kit" made 99mTc-radiopharmaceuticals.

Chromatography, Paper↗
PubMed1986

[CT findings in acute spinal epidural hematoma caused by a ruptured cavernous angioma].

A case of acute spinal epidural hematoma due to the rupture of cavernous angioma is reported. A 68-year-old man was admitted to our hospital with a complaint of hematoemesis. After the successful treatment of bleeding from a gastric ulcer by using endoscopical method, he noticed severe motor weakness in his lower extremities. Complete paraparesis of his lower limbs, total sensory loss below the level of fifth thoracic vertebrae, and bladder disturbance were revealed on neurological examination. A metrizamide myelogram showed complete block at the level of fourth thoracic vertebrae. A computed tomography (CT) scan disclosed a dorsolateral heterogeneous high density area (92 Hounsfield Unit) on the right with displacement of the spinal cord to the left, extending from the level of second to fifth thoracic vertebrae. He was operated thirty hours after the onset. After the laminectomy, an epidural hematoma covering over the dural sac was recognized. Following the removal of the hematoma, a hemorrhagic mass was disclosed and removed successfully. A pathological examination revealed cavernous angioma. His symptoms improved partially in three months after the operation. There have been thirteen cases of non-traumatic spinal epidural hematoma which had been diagnosed by CT scan, as far as we are aware. Although only four cases out of 13 were diagnosed without using any contrast materials, we stress that the spinal epidural hematoma can be diagnosed only by plain CT scan because of its characteristic clinical feature, attenuation coefficient, and mass effect to the spinal cord.

Aged↗
PubMed1986

[Autosomal translocation and associated male infertility].

Four balanced autosomal reciprocal translocations were found through mitotic chromosome analysis among 72 subfertile males, 27 with azoospermia and 45 with sperm counts below 40 X 10(6)/ml. They were 46, XY, t(3; 20; 21) with azoospermia, 46, XY, t(14; 21) with sperm counts below 1 X 10(6)/ml, 46, XY, t(1; 19) lqh+ with azoospermia and 46, XY, t(3; 16) with sperm counts 27 X 10(6)/ml. Histological, cytogenetic and hormonal analysis were performed. Testicular biopsies from the first 3 carriers revealed complete spermatogenic arrest at the spermatocyte stage and meiotic studies of the same biopsies showed severe reduction in numbers of cells in 2nd meiotic division. In spite of severely defective spermatogenesis, serum gonadotropins of the carriers were within normal range, except for LH of the 4th case. Other chromosomal aberrations observed were 5 Klinefelter's syndrome, 2 autosomal minor variants (46, XY, 15p+ and 46, XY, 14s+) and 1 small Y.

Chromosomes, Human, 1-3↗
PubMed1985

Tumor and liver uptake models of 67Ga-citrate.

After administration 67Ga concentrates with time in lysosomes from the cytoplasm of liver cells. The lysosomal role in the accumulation of 67Ga in the liver cell is weakened upon transformation of the liver cell into a malignant tumor cell. In malignant tumors (except for hepatoma) the lysosome does not play a major role in the tumor concentration of 67Ga. 67Ga is bound to acid mucopolysaccharides (keratan polysulfate, etc.) in both tumor and liver. In liver cells, large amounts of 67Ga are transported into lysosomes with these acid mucopolysaccharides, and in hepatoma cells, quite large amounts of 67Ga are transported into lysosomes with these acid mucopolysaccharides. In malignant tumor cells (except for hepatoma) the effect is much smaller, the acid mucopolysaccharides transporting very little 67Ga into lysosome. The 67Ga is concentrated in viable tumor tissue within malignant tissue but hardly at all in necrotic tumor tissue, and concentrates avidly in inflammatory infiltration around tumor cells. Plenty of 67Ga is found in liver but very little in connective tissue associated with the liver.

Animals↗