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Biomedical subjects

K Kitamura

Publications and source records attributed to K Kitamura.

At least 883 records · Page 49Linked to original sources

Non-icteric ampullary carcinoma with a favorable prognosis.

Clinicopathologic findings and clinical follow-up data of 31 patients with non-icteric ampullary carcinoma (NIAC) and 111 patients with icteric ampullary carcinoma (IAC) were retrospectively compared. All of the IAC patients presented with obstructive jaundice. Twenty-three of the 31 NIAC patients developed abdominal pain and/or fever caused by cholangitis or pancreatitis, and the remaining eight patients were asymptomatic. The two groups were not significantly different in age, sex, size of the tumor, macroscopic type, lymph node metastasis, perineural invasion, lymphatic permeation, and venous invasion. Eighteen of the 31 NIACs (58%) were in stages I and II, whereas 25 of the 111 IACs (22%) were in stages I and II (p less than 0.01). Seventeen of the 31 NIACs (55%) were papillary adenocarcinoma, compared with 39 of 111 IACs (35%) (p less than 0.05). As to involvement of the biliary tract, the NIAC showed an intraluminal papillary growth in 14 cases (45%), whereas the IAC showed a periductal invasion in 58 cases (52%) (p less than 0.05). The cumulative 5-yr and 10-yr survival rates of 31 patients with NIAC were 57% and 57%, compared with 32% and 23% of 105 patients with IAC (p less than 0.05; p less than 0.01). The survival curve of the NIAC was significantly better than that of the IAC (p less than 0.01). Non-icteric presentation had no independent prognostic value, as determined by multivariate regression analysis. The NIAC fares better than the IAC, because the NIAC includes a greater number of early ampullary carcinoma and papillary adenocarcinoma. The detection of NIAC may therefore product an improvement in the clinical course of ampullary carcinoma.

Adenocarcinoma, Papillary↗

Increased immunoreactive neuropeptide Y in platelets of spontaneously hypertensive rats (SHR).

A high concentration of immunoreactive neuropeptide Y was observed in rat platelets using a specific and sensitive radioimmunoassay for neuropeptide Y. Three kinds of high performance liquid chromatography combined with radioimmunoassay for neuropeptide Y showed that immunoreactive neuropeptide Y in rat platelets is identical to rat authentic neuropeptide Y. To investigate the pathological role of platelet neuropeptide Y in genetic hypertensive rats, the platelet content and plasma concentration of neuropeptide Y were measured by a sensitive radioimmunoassay for rat neuropeptide Y in 5-, 10- and 15-wk old spontaneously hypertensive rat and age-matched Wistar Kyoto rat. Platelet content of immunoreactive neuropeptide Y in 5-, 10- and 15-wk old spontaneously hypertensive rat was higher than that in Wistar Kyoto rat at each age. No difference was observed in plasma concentration of immunoreactive neuropeptide Y between spontaneously hypertensive rat and Wistar Kyoto rat at each age.

Animals↗

A fluorescence sandwich ELISA for detecting soluble and cell-associated human interleukin-2.

A fluorescence sandwich ELISA was developed for the quantitation of human interleukin-2 (IL-2) using a combination of two anti-human IL-2 antibodies, L61 and biotinylated anti-IL-2 rabbit IgG. The minimum level of IL-2 detectable by this ELISA was 0.3 pg/ml, indicating that this method is about 100 times more sensitive than the usual colorimetric human IL-2 ELISA. The ELISA specifically detected human IL-2 in cell culture supernatants and serum, and also in extracts from mitogen-stimulated peripheral blood mononuclear cells. All of the IL-2 species detected in the supernatants, sera and cell lysates were shown to have a molecular weight of 15,000, as estimated by size exclusion high performance liquid chromatography.

Animals↗

Immunoreactive endothelin in rat kidney inner medulla: marked decrease in spontaneously hypertensive rats.

Using a specific and sensitive radioimmunoassay for endothelin, the regional distribution and molecular form of endothelin was investigated in rat tissue. The highest concentration was observed in the inner medulla of the kidney (8.7 +/- 2.2 pg/mg wet weight). On two kinds of reverse phase high performance liquid chromatography, immunoreactive endothelin in the inner medulla of the kidney was separated into two peaks at positions where authentic porcine/human and putative rat/human endothelin eluted. Furthermore, the concentration of immunoreactive endothelin in the inner medulla of the kidney was remarkably decreased in spontaneously hypertensive rats (SHR) compared with normotensive control Wistar Kyoto rats (WKY) but no difference was observed in lung immunoreactive endothelin.

Amino Acid Sequence↗

Purification and characterization of rat skeletal muscle fructose-6-phosphate,2-kinase:fructose-2,6-bisphosphatase.

Fructose-6-phosphate,2-kinase:fructose-2,6-bis-phosphatase from rat skeletal muscle has been purified to homogeneity, and its structure and kinetic properties have been determined. The Mr of the native enzyme was 100,000 and the subunit Mr was 54,000. The apparent Km values of fructose-6-P,2-kinase for Fru-6-P and ATP were 56 and 48 microM, respectively. The apparent Km value for Fru-2,6-P2 of fructose-2,6-bis-phosphatase was 0.4 microM, and the Ki for Fru-6-P was 12.5 microM. The enzyme was bifunctional, and the phosphatase activity was 2.5 times higher than the kinase activity. The enzyme was not phosphorylated by cAMP-dependent protein kinase. The amino acid composition of the skeletal muscle enzyme was similar to that of the rat liver enzyme, and the carboxyl terminus sequence (His-Tyr) was the same as that of the liver enzyme. The tryptic peptides generated from the liver and skeletal muscle enzymes were identical except for two peptides. A peptide corresponding to nucleotides 14-28 of the rat liver enzyme was not detected in the skeletal muscle enzyme. A peptide whose amino acid sequence was Thr-Ala-Ser-Ile-Pro-Gln-Phe-Thr-Asn-Ser-Pro-Thr-Met-Val-Ile-Met-Val-Gly-Leu-Pro - Ala-Arg was also isolated. This peptide was the same as that of rat liver enzyme (nucleotides 31-52) containing the phosphorylation site except in the muscle enzyme two amino terminus amino acids, Gly-Ser(P), have been altered to Thr-Ala. Thus, the rat skeletal muscle enzyme is very similar in structure to the rat liver enzyme except for the lack of possibly one peptide and the lack of a phosphorylation site by the substitution of the target Ser with Ala.

Amino Acid Sequence↗

Soluble IL-2 receptor in AIDS. Correlation of its serum level with the classification of HIV-induced diseases and its characterization.

By using a fluorescence sandwich ELISA, elevated IL-2R levels were detected in the sera from both HIV-infected hemophiliacs and other HIV-infected patients. The serum IL-2R levels were reflective of the classification of HIV-induced diseases by the Centers for Disease Control. Moreover, the IL-2R levels were negatively correlated most prominently with CD4 cell counts, with lymphocyte counts, and with a decrease in the CD4-CD8 ratio but not with either WBC counts or B cell counts. As striking elevations of serum IL-2R were noted in AIDS patients with group IVD infection, the serum IL-2R was purified sequentially by using size-exclusion HPLC, high-pressure chromatofocusing, and H48 affinity HPLC. The isoelectric point values of IL-2R were separated into 4.2 and 3.8, whereas the Mr was determined to be only 45 kDa by immunoprecipitation with H48 antibody followed by SDS-PAGE. However, production of cellular and supernatant IL-2R was not elevated in PBMC of patients with AIDS or in any of the 19 HIV-I- or HIV-II-infected cell line cells. In contrast, PBMC from patients with adult T cell leukemia and cell line cells that expressed human T cell lymphotropic virus -I or -II produced soluble IL-2R, constitutively. The mechanisms by which serum levels of IL-2R might be elevated in HIV-infected patients are discussed in comparison with that in adult T cell leukemia patients.

Acquired Immunodeficiency Syndrome↗

Regional distribution of immunoreactive endothelin in porcine tissue: abundance in inner medulla of kidney.

A specific and sensitive radioimmunoassay for endothelin has been developed. Half maximal inhibition of binding of radioiodinated endothelin was observed at 37 pg/tube and endothelin was detectable as low as 1 pg/tube. With this assay, the regional distribution of endothelin was determined in porcine tissue. The highest concentration of immunoreactive endothelin was observed in inner medulla of kidney (6.2 +/- 1.1 pg/mg wet weight), while the concentration in kidney cortex was very low. Immunoreactive endothelin was also found in lung in relatively high concentration. The immunoreactive endothelin in porcine lung and inner medulla of kidney was further characterized by reverse phase high performance liquid chromatography combined with radioimmunoassay.

Animals↗

[Enhancing effect by anti-cancer drugs on growth inhibition of colon carcinoma in nude mice by monoclonal antibody and complement].

We investigated the possible sero-therapeutic application of monoclonal antibody-A7 against human colorectal cancer. In complement dependent cytotoxicity, A7 showed 59% cytotoxicity against SW1116 cells. In addition, the killing of tumor cells by A7 and C was enhanced when the tumor cells were pretreated with 2 micrograms/ml mitomycin and 40 micrograms/ml adriamycin. Next, we evaluated the in vivo antitumor effect of A7 alone and combined with MMC on human colon cancer (Colon-6) bearing nude mice. The group injected with A7 alone showed definite antitumor effect compared with the non-treated group. The A7+MMC group (MMC: 4mg/kg, A7: 1 mg/body, two times) showed enhanced antitumor effect compared with the groups administered A7 alone or MMC alone.

Animals↗

Catalytic site of rat liver and bovine heart fructose-6-phosphate,2-kinase:fructose-2,6-bisphosphatase. Identification of fructose 6-phosphate binding site.

Fructose-6-P binding sites of rat liver and bovine heart Fru-6-P,2-kinase:Fru-2,6-bisphosphatase were investigated with an affinity labeling reagent, N-bromoacetylethanolamine phosphate. The rat liver enzyme was inactivated 97% by the reagent in 60 min, and the rate of inactivation followed pseudo-first order kinetics. The bovine heart enzyme was inactivated 90% within 60 min, but the inactivation rate followed pseudo-first order up to 80% inactivation and then became nonlinear. The presence of fructose-6-P retarded the extent of the inactivation to approximately 40% in 60 min. In order to determine the amino acid sequence of the fructose-6-P binding site, both enzymes were reacted with N-bromo[14C]acetylethanolamine-P and digested with trypsin; radiolabeled tryptic peptides were isolated and sequenced. A single 14C-labeled peptide was isolated from the rat liver enzyme, and the amino acid sequence of the peptide was determined as Lys-Gln-Cys-Ala-Leu-Ala-Leu-Lys. A major and two minor peptides were isolated from bovine heart enzyme whose amino acid sequences were Lys-Gln-Cys-Ala-Leu-Val-Ala-Leu-Lys, Arg-Ile-Glu-Cys-Tyr-Lys, and Ile-Glu-Cys-Tyr-Lys, respectively. In all cases, N-bromoacetylethanolamine-P had alkylated the cysteine residues. The amount of bromo[14C]acetylethanolamine-P incorporated into rat liver and beef heart was 1.3 mol/mol of subunit and 2.1 mol/mol of subunit, respectively, and the incorporations in the presence of Fru-6-P were reduced to 0.34 mol/mol of subunit and 0.9 mol/mol of subunit, respectively. Thus, the main fructose-6-P binding site of rat liver and bovine heart enzymes was identical except for a single amino acid substitution of valine for alanine in the latter enzyme. This peptide corresponded to residues 105 to 113 from the N terminus of the known amino acid sequence of rat liver enzyme, but since the complete sequence of bovine heart enzyme is not known, the location of the same peptide in the heart enzyme cannot be assigned.

Affinity Labels↗

Mode of binding of E-64-c, a potent thiol protease inhibitor, to papain as determined by X-ray crystal analysis of the complex.

The three-dimensional structure of the E-64-c-papain complex has been determined by X-ray crystal analysis at 2.5 A resolution (conventional R = 26.9%). The structure determined indicates that: (i) the C2 atom of the oxirane ring of E-64-c is covalently bound by the S gamma atom of Cys-25 of papain; (ii) this covalent bond formation results in a configurational conversion of the oxirane C2 atom from the S- to the R-form; and (iii) extensive hydrogen bonding and hydrophobic interactions are responsible for the specific interaction of the E-64-c molecule with papain.

Binding Sites↗

Chondromyxoid fibroma of the mastoid invading the occipital bone.

We describe a case of chondromyxoid fibroma of the mastoid bone extending along the occipital bone in a 48-year-old man. The presence of this tumor was heralded solely by aural fullness caused by otitis media with effusion. The tumor arose from the mastoid cavity, eroding the entire petrous portion, and invading the foramen magnum and jugular foramen. The occurrence of this tumor is exceedingly rare, and, to our knowledge, this is only the second article in the literature that describes a chondromyxoid fibroma of the mastoid region. The clinical appearance of this tumor and its light- and electron-microscopic findings are presented with reference to other articles.

Chondroma↗

Modulation produced by nifedipine of the unitary Ba current of dispersed smooth muscle cells of the rabbit ileum.

Using a whole-cell clamp technique on longitudinal smooth muscle cells of the rabbit ileum, it was found that the rate of decay of the macroscopic Ba current evoked by depolarization (to +20 mV) was not modified by changing the holding potential from -60 mV to -30 mV. Cadmium (20 microM) left only a small transient inward current. Using the patch clamp technique with cell-attached configuration, only one type of unitary Ba current, with conductance of 25 pS was obtained in 100 mM Ba solution. The conductance depended on the external Ba concentration, had a dissociation constant of 19 mM and maximum conductance of 42 pS, suggesting that the Ca channel is of the L-type. Depolarizing pulses (to 0 mV and 150 ms duration) delivered at a frequency of 0.5 Hz (high frequency) evoked a unitary Ba current with low open probability (p less than 0.3). However 65-75% of depolarizing pulses evoked no unitary Ba current ("blank" sweep). On the other hand, depolarizing pulses at 0.033 Hz (low frequency) reduced the number of "blank" sweeps (20-50%), and increased the fraction of sweeps with high open probability (p greater than 0.5). Thus, the channel activity may depend on the stimulus frequency. Nifedipine, in both stimulus conditions, reduced the open probability of the channel due to an increase in the fraction of "blank" sweeps to a greater extent than to a decrease in the time constant of open-times.

Animals↗

Surgical treatment for paediatric patients with moyamoya disease by indirect revascularization procedures (EDAS, EMS, EMAS).

Surgical results of paediatric patients with Moyamoya disease who were treated by indirect revascularization procedures are reported. Encephalo-duro-arterio-synangiosis (EDAS), encephalomyo-arterio-synangiosis (EMAS), and/or encephalo-myo-synangiosis (EMS) were performed on 47 sides of 29 children with Moyamoya disease. The results of those non-anastomotic EC-IC bypass procedures were evaluated clinically, angiographically, and by computed tomography (CT). Postoperative external carotid angiograms showed a good collateral formation through EDAS, EMAS, or EMS in about 70-80 percent of all surgically treated sides. The symptoms such as TIA, RIND, and/or involuntary movements disappeared in the cases with a good collateral formation but not in those with insufficient development of the collateral circulation. The indirect EC-IC bypass surgery seems effective for most of the children with Moyamoya disease who present with ischaemic signs.

Angiography↗

Splenic hamartoma: report of a case and review of the literature.

A 39-year-old Japanese man with a splenic hamartoma who underwent surgery, is reported herein. The patient had a volvulus of the transverse colon and acute Type A hepatitis. His symptoms included fever, abdominal pain and icterus and the serum chemistry showed liver dysfunction and an elevation of hepatitis A antibody levels. Barium enema revealed a volvulus of the transverse colon. Ultrasonogram showed a hypoechoic mass and angiogram showed evidence of stretching of the intrasplenic vessels in the arterial phase and a hypovascular mass lesion in the venous phase. Macroscopically, the tumor was a well-defined, whitish-yellow, hard nodule. Microscopically, the tumor was composed of fibrous scar tissue containing scattered red pulp tissues and the histologic diagnosis was a splenic hamartoma of the fibrous type. The patient's postoperative recovery was uneventful. The clinical features of splenic hamartoma are reviewed in this report and the differential diagnosis is also discussed.

Adult↗

A tumor-associated antigen in the scirrhous gastric carcinoma cell line MK-01 defined by monoclonal antibody S202.

A monoclonal antibody (MAb) S202, with an IgG1 isotype, that reacted strongly with the scirrhous gastric carcinoma cell line MK-01 was established. MAb S202 reacted with the colonic cancer cell line, SW1116, and the pancreatic cancer cell line, PK-1, when tested by indirect immunofluorescence. The S202 reactive antigen was expressed in the majority of acetone-fixed fresh frozen cancer tissues. Eighty to 100 per cent of the paraffin-embedded sections of stomach, colon and pancreatic adenocarcinoma were positive for the S202 antigen, with diffuse cytoplasmic staining, whereas esophageal and breast cancers demonstrated markedly less immunostaining. Supplemented serum-free medium collected from 7 day old tumor cell cultures were assayed for the presence of antibody-defined antigens. Antigens detected by MAb S202 were released by the cell lines SW1116 and PK-1. The binding of MAb S202 to the colonic adenocarcinoma sections was reduced after treatment with sodium periodate which suggests that respective antigenic determinants are of carbohydrate nature without sialic acid residues.

Adenocarcinoma, Scirrhous↗

Lymphangioma of the stomach--report of a case and review of the literature.

A rare case of a 66 year old man with lymphangioma of the stomach is presented herein. Upper gastrointestinal X-ray series revealed a slow growing submucosal tumor in the anterior wall of the antrum of the stomach which was subsequently found to be lymphangioma after a partial gastrectomy. To our knowledge, this is only the thirteenth case of lymphangioma of the stomach to have been reported in the English literature. A brief review of the English and Japanese literature is presented following the case report.

Aged↗