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Biomedical subjects

H Ohtani

Publications and source records attributed to H Ohtani.

At least 307 records · Page 17Linked to original sources
PubMed1992

Comparison of technetium-99m-glucarate and thallium-201 for the identification of acute myocardial infarction in rats.

The scintigraphic identification of acute severe ischemic myocardial injury requires a marker that localizes rapidly and specifically in zones of damaged myocardium. Technetium-99m-glucarate, a six-carbon dicarboxylic acid, which behaves in vivo somewhat like fructose, was recently described as a marker of severe acute ischemic injury with necrosis. This study was performed to determine the interval between the onset of myocardial ischemia and initial uptake and the duration of a positive scan in experimental animals. Serial injections and images were recorded over 10 days following ligation of the left anterior descending coronary artery of the rat. The distribution of 99mTc-glucarate was compared to that of regional myocardial perfusion monitored with 201TI. The findings on radionuclide imaging were compared to histologic changes in the myocardium. Sequential pinhole images of both radionuclides were collected at 3 hr, 24 hr, 72 hr and 7-10 days following ligation. Ten rats had normal 201TI distributions, no uptake of glucarate and no evidence of infarction by TTC staining at autopsy. Twenty-one rats had either 201TI lesions or evidence of infarction at autopsy. In 17 of these rats, significant acute 99mTc-glucarate uptake was noted, decreasing at 24 hr, and was not seen at 72 hr or 7-10 days. The extent of perfusion abnormality was greatest at 3 hr in most animals; the lesion decreased in four (33%), increased in one (8%) and remained stable in the remainder. These data suggest that 99mTc-glucarate may be a useful marker of acute myocardial injury.

Animals↗
PubMed1992

[Renal and electrolyte disturbances in chronic myelogenous leukemia].

Renal and electrolyte disturbances in 91 patients with chronic myelogenous leukemia (CML) were analyzed over a period of these twenty years. At diagnosis, renal and electrolytes were studied in 72 patients including 65 in chronic cases, 5 in accelerated phase and 2 in blastic crisis. There were 8 cases of hypocalcemia among 62 patients and 5 cases of hyperphosphatemia among 48 patients. The cases of hyperphosphatemia and renal dysfunction had short median survival. There were no significant differences of renal and electrolyte disturbances between before and after chemotherapy. Various electrolyte disturbances, that is, hyponatremia, hypo-, hyperkalemia, hypocalcemia, hypo-, hyperphosphatemia, were found in the blastic crisis of CML. In the last admission, renal dysfunction and various electrolyte disturbances were present in almost half of the cases. Pathological studies were performed in 18 autopsy cases. Acute tubular insufficiency or necrosis, hypercalcemic nephropathy, and renal infiltration of leukemic cells were recognized in patients who had renal dysfunction.

Adolescent↗
PubMed1992

Appearance of Ulex europaeus agglutinin-1 and Griffonia simplicifolia agglutinin-1 binding sites on cancer cells in sigmo-rectal polyps.

Ninety-three polypectomized cases from the sigmo-rectal region were examined by lectin histochemistry. On the apical surface, the UEA-1 binding sites were positive in 24/29 carcinomas and in 25/62 adenomas; while the GSA-1 binding sites were positive in 16/29 carcinomas and in 0/62 adenomas. In 2 non-neoplastic polyps, only one case was UEA-1 positive; none was GSA-1 positive. In neighbouring regions, adenomas adjacent to carcinomas were UEA-1 positive in 9/27 cases and GSA-1 positive in 3/37 cases. Thus, the GSA-1 binding sites were expressed more specifically on carcinomas. In the Golgi area, none of the polyps was UEA-1 positive while most of the cells showing GSA-1 positivity were apt to do so within the cells without showing GSA-1 positivity on the apical surface. There were no correlations between the positive rate of the lectin binding sites on the apical surface and the stage of cancer development or the histology of the adenoma on which a cancer developed. The meaning of this restricted appearance of the GSA-1 binding sites on the cancer cell surface was discussed in relation to observations previously reported in the literature.

Adenocarcinoma↗
PubMed1991

Diffuse large cell lymphoma occurring in a patient with Waldenström's macroglobulinemia. Evidence for the two different clones in Richter's syndrome.

The authors report a 60-year-old man with Richter's syndrome, or diffuse large cell lymphoma (DLCL) occurring in a patient with either chronic lymphocytic leukemia (CLL) or Waldenström's macroglobulinemia (WM). Surface marker analysis revealed that the WM showed mu kappa surface immunoglobulin (Ig) chains, and that the DLCL showed mu lambda Ig chains. Flow cytometric DNA analysis demonstrated DNA content differences between WM and DLCL, the former diploid and the latter aneuploid. The current study suggests that Richter's syndrome derives from two independent B-cell malignancies.

DNA↗
PubMed1991

Immunocytochemical study on endothelial markers with the cerebral vessel from a patient with familial moyamoya disease.

The immunocytochemical study of thrombomodulin (TM), a newly recognized anticoagulant endothelial surface protein, was performed with a surgical specimen of a superficial temporal artery (STA) obtained from a 29-year-old woman with familial moyamoya disease. The staining of TM showed positive immunoreactivity in smaller vessels in the surrounding connective tissue of the specimen, whereas negative in STA. Immunoelectronmicroscopically the luminal plasma membrane of endothelial cells was positive for TM. These staining pattern was the same as that in controls. She concurrently suffered from von Willebrand disease type I, and she had two cerebral hemorrhagic attacks. A quantitative defect of the von Willebrand factor in the endothelium was demonstrated immunocytochemically.

Adult↗
PubMed1991

Continued blood cell formation in spherical bodies in a long-term mouse spleen culture.

During the primary culture of spleen fragments of newborn mice, a spherical body (d = circa 200 to 300 microns) as a three-dimensional cellular organization was formed. Continued production of blood cells from the spherical body was observed without changing its size for about 2 months of culture. Without growth factor, the spherical bodies produced mainly lymphocytes and macrophages. Addition of interleukin-3 enhanced their granulocyte formation, and this enhancement was observed even after a prolonged maintenance without growth factors. The spherical bodies were composed of a uniform mixture of endothelial cells and fibroblasts within the body, and cell-cell contacts between lymphocytes and fibroblasts were notable in the periphery. With prolonged culture, the spherical bodies showed a definite change in their structure by sorting two cell types and the blood cell production gradually decreased. These results suggested that a three-dimensional structure was required for the maintenance, growth, and differentiation of blood cell progenitors in the long-term spleen culture.

Animals↗
PubMed1991

Metabolic changes in LDL receptors and an appearance of scavenger receptors after phorbol ester-induced differentiation of U937 cells.

Metabolic changes in lipoprotein receptors after cell differentiation were investigated using U937 cells, a human tumor cell line with monoblastic characteristics. After inducing the differentiation of U937 cells into monocyte-macrophage-like cells using TPA (12-tetradecanoyl-phorbol-13-acetate), the incorpotation of [14C]oleate into cellular cholesteryl [14C]oleate was increased in comparison with U937 cells when incubated with r-beta VLDL, h-VLDL or h-LDL. A marked down-regulation of LDL receptors was observed in U937 cells upon addition of 25-hydroxycholesterol. However, this down-regulation of LDL receptors was poor in monocyte-macrophage-like cells that had been induced to differentiate from U937 cells with TPA. Acyl coenzyme A:cholesterol acyltransferase activity was increased after TPA-induced differentiation of U-937 cells. The incorporation of [14C]oleate into cellular cholesteryl [14C]oleate was also increased when incubated with acetylated h-LDL in monocyte-macrophage-like cells in comparison with U937 cells. These results suggest that a poor down-regulation of LDL receptors, which is attributable to increased acyl coenzyme A:cholesterol acyltransferase activity, and scavenger receptors are induced and that these metabolic changes in lipoprotein receptors and an increased acyl coenzyme A:cholesterol acyltransferase activity contribute to cholesterol ester accumulation in monocyte-macrophage-like cells.

Acyl Coenzyme A↗
PubMed1991

Analysis of neutral amino acid transport systems in the small intestine: a study of brush border membrane vesicles.

Transport of L-proline, L-leucine and L-cysteine was studied in brush border membrane vesicles prepared from guinea pig ileum. Concentrative transport of L-proline, L-leucine and L-cysteine was obtained in the presence of an Na+ gradient from, outside to inside of the vesicles, which indicated contribution of either system A (alanine-preferring) or system ASC (alanine-, serine- and cysteine-preferring) to the transport. When Na+ was replaced by Li+, L-leucine and L-cysteine maintained the same concentrative transport. However, the concentrative transport of L-proline was markedly decreased by Li+ -for-Na+ substitution. Strong exchange properties of L-leucine transport via system L (leucine-preferring) was observed with brush border membrane vesicles, in which preloaded L-methionine could be exchanged with labeled L-leucine added outside the vesicles. These results suggest that the small intestine of the guinea pig possesses classical neutral amino acid transport systems such as systems A, ASC and L.

Alanine↗
PubMed1991

Immunohistochemical characterization, distribution and ultrastructure of lymphocytes bearing the gamma/delta T-cell receptor in the human gut.

The phenotypic characterization and distribution of lymphocytes bearing the gamma/delta T-cell receptor (TCR) in the human gut were investigated by an immunohistochemical technique. A mirror section technique and double staining method were used for the phenotypic analysis. Intraepithelial delta-positive cells were almost all CD8-positive and rarely negative for both CD4 and CD8. On the other hand, lymphocytes bearing TCR gamma/delta in the lamina propria were largely negative for both CD4 and CD8. The ratio of delta-positive to CD3-positive cells amongst intraepithelial lymphocytes was larger in the lower intestine. Delta-positive cells were also observed in paracortical areas of lymphoid follicles. Immunoelectron microscopic observation revealed granular structures in these delta-positive cells, which are also present in large granular lymphocytes. The role of lymphocytes bearing TCR gamma/delta in mucosal immune responses in the human gut are discussed.

Adult↗
PubMed1991

Immunohistochemical characterization, distribution, and ultrastructure of lymphocytes bearing T-cell receptor gamma/delta in inflammatory bowel disease.

Phenotypic characterization and distribution of gamma/delta T lymphocytes in the intestinal mucosa were investigated in ulcerative colitis and Crohn's disease by immunohistochemistry. The ratio of delta(+) cells to CD3(+) cells in the intraepithelial space of colon was decreased in Crohn's disease (13%) and strikingly decreased in ulcerative colitis (8%) compared with the control (36%). Delta(+) cells in the lamina propria were also decreased, particularly in the distal ileum of Crohn's disease (4%), compared with the control (15%). On the contrary, the cells gathered at the severe inflammatory sites with other inflammatory cells, including beta(+) cells, and were densely distributed in the T-cell zone around lymphoid follicles. Phenotypic characterization showed that delta(+) lamina proprial lymphocytes of colon were mainly CD4(-)CD8(-) in the control (80%) and Crohn's disease (59%). However, in ulcerative colitis, CD4(-)CD8(-) delta(+) lymphocytes were rarely found (3%). This reflects the difference of immunologic background between the two diseases. Immunoelectron microscopically, these cells in inflammatory bowel disease were rich with vesicular structures in cytoplasms, whereas those in the control group contained electron-opaque granules. The decrease and the morphological change may be closely related to the weakness of mucosal defense.

Adult↗
PubMed1991

Molecular cloning of rat cerebellin-like protein cDNA which encodes a novel membrane-associated glycoprotein.

Rat cerebellin and an apparent metabolite des-Ser1-cerebellin have been shown to be located in cerebellar Purkinje cells and the dorsal cochlear nucleus. A cDNA clone was isolated by screening a rat brain cDNA library using an oligonucleotide corresponding to rat cerebellins. The clone encodes 224 amino acid residues of a glycoprotein a part of whose sequence is virtually the same as that of cerebellins and which contains one putative transmembrane spanning domain. Neither an N-terminal cleavable signal peptide nor dibasic pair specific endopeptidase directly precedes or follows the cerebellin-like sequence. Expression of the cerebellin-like protein gene is developmentally regulated in rat cerebellum and shows tissue specific alternative splicing in the brain, adrenal gland and spleen of the rat. The results of Southern blot indicated the gene to possibly be a member of some gene family. Rat cerebellin-like protein, possibly a precursor of cerebellins, is a novel membrane-associated glycoprotein expressed in nervous, adrenal and immune systems and appears to synaptic functions in the central nervous system.

Amino Acid Sequence↗
PubMed1991

Immunoelectron microscopic localization of DF 3 cancer-associated antigen in human breast cancer.

Breast cancer cells are characterized by frequent occurrence of the DF 3 breast-cancer associated antigen in the cytoplasmic area. This study elucidated the details of this cytoplasmic reactivity by immunoelectron microscopy. In infiltrating breast carcinomas, the DF 3 antigen was localized in rough endoplasmic reticulum (rER), perinuclear space, Golgi complex, membrane-bound granules and along the outer surface of cell membrane. The antigen was also accumulated in the cytosol. In contrast to this, benign lesions showed localization of the DF 3 antigen mainly along the outer surface of apical cell membrane and rarely in rER or cytosol. The present study indicated that the DF 3 antigen was of secretory type and commonly localized on the outer surface of apical cell membrane in both malignant and benign lesions. Carcinoma tissues were further characterized by frequent occurrence of immunoreactivity related to the process of antigen synthesis. The diffuse cytosolic reactivity may be associated with disordered transportation of the antigen in the cytoplasm.

Antigens, Neoplasm↗
PubMed1991

HLA-DR expression on M cells overlying Peyer's patches is a common feature of human small intestine.

The expression of major histocompatibility complex (MHC) class II (HLA-DR) antigens on M cells within follicle-associated epithelial cells (FAE) covering Peyer's patches was analyzed immunohistochemically. HLA-DR antigens were strongly expressed on M cells and cells with dendritic morphology, whereas other FAE covering Peyer's patches showed weak, but definite staining. Dendritic cells were also positive for S-100 protein and IL-1. These findings suggest that M cells as well as dendritic cells within FAE form an antigen-presenting cell system and contribute to the first information releaser for the mucosal immune system.

Dendritic Cells↗
PubMed1991

Isomerization of lactose in solid-state by mechanical stress during grinding.

Isomerization during grinding of solid-state alpha-monohydrate, alpha-anhydrate and beta-anhydrate of lactose was investigated. Samples were ground in an agate centrifugal ball-mill at 270 rev min-1 at room temperature (20 degrees C). The crystallinity of ground lactose was measured by Hermans' method from the powder X-ray diffraction profiles. The alpha- and beta-lactose content of the ground lactose was obtained from the specific rotation measured by using angular rotation spectrophotometry. The crystalline lactose samples were transformed into non-crystalline solids by mechanical stress during grinding. After grinding, the water content of all ground lactose samples increased, and the samples had about 2 mol water per lactose after 10 h grinding. After 10 h grinding of alpha-monohydrate and alpha-anhydrate, 10 and 15%, respectively, of alpha-lactose was transformed into beta-lactose by the mechanical treatment. After 10 h grinding of beta-lactose, 20% of beta-lactose was transformed into alpha-lactose. The results suggest that crystalline lactose was transformed into a non-crystalline solid, and water was adsorbed on the non-crystalline lactose. The non-crystalline solids of alpha- or beta-lactose were then transformed into their counterparts by the mechanochemical effects of grinding.

Chemical Phenomena↗
PubMed1991

Qualitative difference of subcellular localization of tumor-associated carbohydrate (Le(x)) antigens in renal cell carcinoma and normal kidney.

Renal cell carcinomas are immunohistochemically positive for oligosaccharides with the Le(x) determinant (Gal beta 1----4[Fuc alpha 1----3]GlcNAc) and its derivatives, as oncofetal antigens, and their expression is closely related to a better prognosis of the patients. This study was designed to clarify the difference in antigen localization at the ultrastructural level between renal cell carcinoma and normal tissues. In normal kidneys, Le(x) detected by monoclonal antibody (MAb) FH 2 and sialylated extended Le(x) (sialyl Le(x)-i) by MAb FH 6 were identified along the plasma membrane of microvilli of proximal tubule epithelial cells, with occasional immunoreactivity along the basolateral plasma membranes. Intracellular localization was very sparse. Renal cell carcinoma showed localization of Le(x) and sialyl Le(x)-i antigens along the cell membrane and in the cytosol as aggregates or filaments. Immunoreactive materials were also observed in the lumen formed among carcinoma cells. The cytosolic immunoreactivity, not observed in the normal kidney, was regarded as "abnormal cytosolic accumulation" of the antigens. This pattern was more pronounced in clear-cell carcinoma. Pretreatment of specimens with chloroform-methanol, which extracts glycolipids, decreased immunoreactivity in carcinoma tissues, particularly that in the cytosol. The extracts contained substances immunoreactive for MAb FH6. Our study has demonstrated that (a) remarkable changes occur in the ultrastructural localization patterns of sialyl Le(x)-i and Le(x) in renal cell carcinoma and (b) considerable amounts of glycolipids are contained in the substances with sialyl Le(x)-i deposited in the cytosol of clear-cell carcinoma.

Adenocarcinoma↗
PubMed1991

[Development and evaluation of the comment aid system for therapeutic drug monitoring. I. Application to valproate].

A comment aid system for therapeutic drug monitoring (TDM), which produces the primary comment on the dosage regimen of valproate, was developed. This system produces consulting comments with a fuzzy theory, by using the dosage regimen of valproate, pharmacokinetic parameters estimated by the Bayesian method, and therapeutic effect and toxicity of anticonvulsants evaluated by the physician. For nearly 90% in 42 cases, comments of the system were agreeable comparing with the notes of TDM technologists. There are a few disagreements between this system and experts, mainly because the system does not use enough information about combination therapy with other anticonvulsants. Developed comment aid system shows some clinical and educational utility, and suggests significance and possibility of more useful and al around TDM expert system. Then this system might be available as a prototype of the TDM expert system.

Adolescent↗
PubMed1991

Residual neutron-induced radionuclides in samples exposed to the nuclear explosion over Hiroshima: comparison of the measured values with calculated values.

Residual radionuclides induced by neutrons from the Hiroshima atomic bomb have been measured at Kanazawa University for 14 years. The results of 152Eu, 154Eu and 60Co are reviewed in this paper. Where appropriate, an attempt is made to provide our new data with the aim of reinterpreting our published data. From the comparison of the measured values with the calculated values by DS86 methodology, we may point out here: (1) that close agreement was found between measured and calculated values for the specific radioactivity of 152Eu in the samples exposed at ground ranges between 320 m and 720 m; (2) that the calculated/measured ratios for the specific radioactivity of 152Eu were, however, larger than unity in the vicinity of ground zero and smaller than unity at locations more than 1000 m apart from ground zero; (3) that, in the vicinity of ground zero, epithermal neutron fluence evaluated from a set of measured specific radioactivities of 152Eu, 154Eu and 60Co showed a close agreement with the calculated result, whereas thermal neutron fluence evaluated in the same way was different from the calculated result; and (4) that the depth distribution of the specific radioactivity of 152Eu in a wall sample which was exposed at the location 320m from ground zero approximately agreed with the calculated result.

Humans↗