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Biomedical subjects

Y Kitagawa

Publications and source records attributed to Y Kitagawa.

At least 307 records · Page 17Linked to original sources
PubMed1987

Accumulation of 2-amino-6-methyldipyrido[1,2-a:3',2'-d]imidazole and 2-aminodipyrido[1,2-a:3',2'-d]imidazole, carcinogenic glutamic acid pyrolysis products, in plasma of patients with uremia.

In order to investigate the exposure of humans to 2-amino-6-methyldipyrido[1,2-a:3',2'-d]imidazole [(Glu-P-1) Chemical Abstracts Service:67730-11-4] and 2-aminodipyrido[1,2-a:3',2'-d]imidazole [(Glu-P-2) Chemical Abstracts Service:67730-10-3], carcinogenic heterocyclic amines, we developed a high-performance liquid chromatography method to detect Glu-P-1 and Glu-P-2 in biological samples, and compared the plasma levels of the carcinogens in normal subjects with those in uremic patients in which higher incidence of malignancy has been reported. Glu-P-1 and Glu-P-2 levels in plasma of uremic patients before induction of hemodialysis treatment were 12.62 +/- 3.65 (SD) pmol/ml (n = 5) and 14.81 +/- 5.17 pmol/ml (n = 5), respectively, whereas Glu-P-1 and/or Glu-P-2 could be detected in only two of seven normal subjects and the levels were lower than 3.1 pmol/ml. Approximately 10% of these carcinogens in plasma of uremic patients could be removed by the first hemodialysis treatment, and reasonable amounts of these carcinogens could be detected in the dialysate of uremic patients. However, significant amounts of Glu-P-1 and Glu-P-2 were still detected in plasma of all uremic patients even after 1 month-hemodialysis treatments. These results suggest that one of the excretory pathways of these carcinogens is via kidney.

Adult↗
PubMed1987

Hormonal regulation of carbamoyl-phosphate synthetase I synthesis in primary cultured hepatocytes and Reuber hepatoma H-35. Defective regulation in hepatoma cells.

Regulation of carbamoyl-phosphate synthetase I (CPS) synthesis by various hormones was compared in primary cultured hepatocytes from adult rat and in Reuber hepatoma H-35 by pulse labeling of the cells with [35S]methionine. CPS synthesis in hepatocytes was stimulated 8-fold and 5-fold by dexamethasone and glucagon respectively. CPS synthesis in hepatocytes was synergically (about 50-fold) stimulated by a combination of dexamethasone and glucagon. Less synergic stimulation was observed by combining dexamethasone with N6, O2'-dibutyryladenosine 3',5'-monophosphate (dibutyryl-cAMP) or with isoproterenol. The basal level of CPS synthesis in hepatoma cells was higher than that in hepatocytes. CPS synthesis in hepatoma cells was stimulated by dexamethasone and dibutyryl-cAMP but the extent was only 3-fold and 1.8-fold respectively. The synergic effect of combination of dexamethasone and dibutyryl-cAMP was not observed in hepatoma cells. Neither glucagon nor isoproterenol exhibited an appreciable effect on CPS synthesis in hepatoma cells. Insulin and epinephrine suppressed CPS synthesis both in hepatocytes and hepatoma cells. The effect of epinephrine was indicated to be through alpha-adrenergic receptors. The effects of insulin and epinephrine were additive on CPS synthesis both in hepatocytes and hepatoma cells.

Animals↗
PubMed1987

Lithium ion reversibly inhibits inducer-stimulated adipose conversion of 3T3-L1 cells.

Adipose conversion of 3T3-L1 cells by inducers (dexamethasone, 1-methyl-3-isobutylxanthine and insulin) was inhibited by LiCl at concentrations from 2 to 20 mM. The effect of LiCl was reversible and the inhibited cells were converted to adipocytes when stimulated after the removal of LiCl. Inhibition by LiCl of adipose conversion was accompanied with a blockage of the enhanced [3H]thymidine incorporation and cellular proliferation that occurred before the adipocyte phenotype was expressed. Of the cations tested, only Li+ had these effects.

1-Methyl-3-isobutylxanthine↗
PubMed1987

Competition of a growth stimulating-/cholecystokinin (CCK) releasing-peptide (monitor peptide) with epidermal growth factor for binding to 3T3 fibroblasts.

The growth stimulating-/cholecystokinin (CCK) releasing-peptide (monitor peptide) is a peptide purified from rat bile-pancreatic juice on the basis of its stimulatory activity toward pancreatic enzyme secretion. Its multiple functions and peptide sequence suggested that it is distinct from epidermal growth factor (EGF). However, we found that the peptide competes with [125I]-EGF in the binding to Swiss 3T3 fibroblast cells to almost the same extent as unlabeled EGF does. [125I]-EGF binding was inhibited by 50% by the peptide at 82.8 ng/ml and by unlabeled EGF at 71.4 ng/ml. This suggests that the growth stimulating effect of the peptide on 3T3 fibroblasts is mediated via the EGF receptor, and also suggests that the partial homologous sequence between monitor peptide and EGF is required for the receptor binding, or that the EGF receptor has a broad ligand specificity.

Amino Acid Sequence↗
PubMed1987

Specific purification of monoclonal anti-DNA antibodies from culture medium using a DNA-coupled Sepharose 4B affinity column.

Human monoclonal antibodies against DNA were specifically purified from the culture medium of an EBV transformant of SLE patients' lymphocytes using a DNA-coupled Sepharose 4B affinity column. The monoclonal antibodies were eluted from the column with 5% dimethylsulfoxide (pH 10.7) containing 0.5 M NaCl without loss of immunological activity and without contamination by other proteins.

Antibodies, Antinuclear↗
PubMed1987

Importance of biologic status to the postoperative prognosis of patients with stage III nonsmall cell lung cancer.

The prognosis of patients with stage III nonsmall cell lung cancer was studied, with special attention to their biologic status prior to lung resection. The biologic status was estimated from the neutrophil/lymphocyte ratio in the peripheral blood, serum albumin level, and erythrocyte sedimentation rate. Among 46 patients who underwent potentially curative operations, 31 cases of biologic status A or B (more than two parameters normal) revealed 37.6% of a 5-year survival rate, whereas there was no 5-year survivor in 15 cases of biologic status C or D (more than two parameters abnormal). Of the 5-year survival rate in T3N0 disease of biologic status A or B, the 60% surviving (of 10 cases) was in marked contrast to the same stage disease of biologic status C or D where only 1 patient (of 10 cases) was still surviving at more than 30 months. In 30 patients with T3N0, T3N1, and T2N2 diseases of biologic status A or B, where long-term survivors were derived, the 5-year survival rate in 30 patients of biologic status A or B was 36.6% in contrast to no long-term survivor in the same stage diseases of biologic status C or D (n = 25). We conclude that surgical results in stage III nonsmall cell lung cancer will be beneficial in patients of biologic status A or B, but nonbeneficial in patients with the same stage of biologic status C or D.

Adult↗
PubMed1987

Inhibitory effects of tryptophan pyrolysis products on human platelet aggregation through inhibition of prostaglandin endoperoxide synthetase.

To determine the effects of the carcinogenic heterocyclic amines on the stimulus-reaction system in cells, the effects of several such amines, including 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) and 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2), on human platelet aggregation and of Trp-P-1 and Trp-P-2 on human polymorphonuclear leucocyte aggregation were investigated. Of the carcinogens studied, only Trp-P-1 and Trp-P-2 had potent inhibitory effects on human platelet aggregation induced by sodium arachidonate. The concentrations of Trp-P-1 and Trp-P-2 causing 50% inhibition of human platelet aggregation induced by sodium arachidonate were 15 and 25 microM, respectively. The heterocyclic amines examined had no significant effects on human polymorphonuclear leucocyte aggregation. Moreover, radiochemical studies of arachidonate metabolism showed that Trp-P-1 and Trp-P-2 inhibited, in a dose-dependent manner, the formation of cyclooxygenase products in platelets induced by sodium arachidonate. These results indicate that Trp-P-1 and Trp-P-2 have potent inhibitory effects on prostaglandin endoperoxide synthetase in the stimulus-reaction system of human platelets.

Adult↗
PubMed1987

Crohn's disease associated with giant inflammatory polyposis.

We found shallow serpiginous, longitudinal ulcerations in the descending colon at the first examination of a 17-year-old female patient with Crohn's disease. Four months later at the second examination, we observed that a polypoid lesion had formed longitudinally in the region of the healed ulcers. The third examination, one year later, showed the presence of pedunculated and semi-pedunculated giant polyps in the descending colon. The lesion of the descending colon was removed surgically to cure the crampy abdominal pain caused by colonic obstruction. The segmental colectomy specimen showed longitudinally aligned pedunculated polyps of various sizes. The pathological diagnosis was inflammatory polyposis. To the best of our knowledge, there have been very few reports on the appearance of a number of pedunculated polyps such as in this case. This reports shows, through endoscopic pictures, the evolution of the polyp and discusses its formation.

Adolescent↗
PubMed1987

Reversible interconversion between primitive endoderm- and parietal endoderm-like F9 cells demonstrated by mRNAs expression.

The differentiation of retinoic acid-treated F9 cells (primitive endoderm-like F9 cells) into parietal endoderm-like F9 cells induced by dibutyryl cAMP was studied as a culture model of the morphogenesis of early mouse embryo. For this purpose, 6 cDNA clones coding for mRNAs specifically expressed in parietal endoderm-like F9 cells were selected. Northern hybridization of RNA extracted from variously treated F9 cells to nick-translated plasmid DNA of these clones demonstrated the reversible expression of many mRNAs depending on the presence of dibutyryl cAMP in the culture medium. This result suggested that the differentiated state of parietal endoderm, which is formed from primitive endoderm at a position adjacent to the trophectoderm in mouse embryo, can be reversed if the local signal is removed. One of the selected clones, pLAM, hybridized to an mRNA of 6.3 kb and selected mRNA producing a laminin B subunit in an in vitro translation system. This clone has an inserted sequence of 3.1 kb. Among the restriction sites in this sequence, six were consistent with those in a 1.7 kb inserted sequence of pPE 49 and pPE 386, which were isolated by Barlow et al. as laminin B1 clones. An XbaI site found in both pPE 49 and pPE 386 was, however, not found at the corresponding position of pLAM. Dot hybridization of RNA with pLAM showed that expression of laminin B in F9 cells is stimulated more than 100-fold during differentiation of F9 stem cells into parietal endoderm-like F9 cells.

Animals↗
PubMed1987

Two crystalline forms of a lectin from Flammulina veltipes.

A lectin from Flammulina veltipes (Enoki-dake) has been crystallized in a form suitable for crystallographic structure analysis. Two types of crystals were grown: one from polyethylene glycol 6000 solution at pH 7 and the other from ammonium sulfate solution at pH 7. The latter type is more suitable for the crystallographic investigations because of its high resolution X-ray diffraction and smaller number of asymmetric molecules.

Agaricales↗
PubMed1987

Formation of triple-helical nucleic acids studied by using antibodies specific for poly(A).poly(U).poly(U).

The formation of the triple helix of poly(A).poly(U).poly(U) was studied by using antibodies specific to poly(A).poly(U).poly(U). the 10-11 base chain length for oligo(A) and the 20-30 base chain length for oligo(U) may be the minimum sizes required to maintain a stable triple helix. Double-stranded poly(A).poly(U) which was the core of triple-stranded poly(A).poly(U).poly(U) could bind poly(U) and produce an analogue of poly(A).poly(U).poly(U) reactive with the antibodies even if the poly(A) or poly(U) was brominated or acetylated to the extent of 35-55%. However, brominated or acetylated poly(U) did not produce a stable triple helix with double-stranded poly(A).poly(U).

Acetylation↗
PubMed1987

Somatostatin suppresses plasma aldosterone concentration in a case of Bartter's syndrome.

The study was conducted to examine the effect of somatostatin on activated renin-angiotensin-aldosterone system in a case of Bartter's syndrome. After 60 minutes of 500 micrograms of somatostatin infusion, the plasma aldosterone concentration was reduced from the basal level of 250 pg/ml to 140 pg/ml, whereas plasma renin activity remained at the basal level. This result suggests that somatostatin may specifically inhibit aldosterone secretion in Bartter's syndrome and the agent can be applied to a treatment of this syndrome.

Adrenocorticotropic Hormone↗
PubMed1987

[A case of gastric cancer with peritonitis carcinomatosa which improved upon oral administration of UFT, mitomycin C and lentinan].

A 29-year-old male visited our hospital because of lower abdominal pain. Acute appendicitis was suspected, and surgery was performed. However, no abnormality was found in the vermiform appendix. Instead, atrophy of the greater omentum, numerous nodes of varying sizes, and a small amount of ascites were observed. On the basis of histological examination, a diagnosis of metastatic glandular cancer was made. Gastric fluoroscopy performed 2 months earlier in another hospital had revealed irregularity of the stomach wall and a large concave area on the side of the greater curvature. Photogastroscopy and CT demonstrated progressive Borrmann type III cancer at the corresponding site and metastasis to regional lymph nodes. Biopsy findings were similar to the histological findings. After 1 week, treatment with UFT (400 mg/day), MMC (10 mg/month) and LNT (1 mg/week) was initiated. After about 3 months, i.e., following administration of 40 g UFT, 30 mg MMC and 8 mg LNT, gastric fluoroscopy and photogastroscopy revealed complete disappearance of the tumor. No abnormality was found by laboratory studies. The patient has since returned to a normal life.

Adenocarcinoma↗