Biomedical subjects

K Tsuji

Publications and source records attributed to K Tsuji.

At least 595 records · Page 33Linked to original sources

PubMed1987

Effects of naloxone on basal and vagus nerve-induced secretions of GRP, gastrin, and somatostatin from the isolated perfused rat stomach.

The effects of naloxone, an opiate antagonist, on basal and vagus nerve-induced secretions of GRP, gastrin, and somatostatin were examined using the isolated perfused rat stomach prepared with vagal innervation. Naloxone (10(-6) M) significantly inhibited basal somatostatin secretion in the presence and absence of atropine and of hexamethonium, whereas basal GRP and gastrin secretion was not affected by naloxone. Electrical stimulation (10 Hz, lms duration, 10V) of the distal end of the subdiaphragmatic vagal trunks elicited a significant increase in both GRP and gastrin but a decrease in somatostatin. Naloxone (10(-6) M) failed to affect these responses in the presence or absence of atropine. On the other hand, when hexamethonium was infused, naloxone significantly inhibited both the GRP and gastrin responses to electrical vagal stimulation. Somatostatin secretion was unchanged by vagal stimulation during the infusion of hexamethonium with or without naloxone. These findings suggest that basal somatostatin secretion is under the control of an opiate neuron and that opioid peptides might be involved in vagal regulation of GRP and gastrin secretion.

Animals↗

PubMed1987

The role of transfected HLA-DQ genes in the mixed lymphocyte reaction-like condition.

DR gene products are commonly thought to be involved in the induction of the mixed lymphocyte reaction (MLR). However, very little is known about the role of HLA-DQ antigens in the MLR. To address this question, we introduced DQ alpha and beta chain genes into mouse L cells, a human T-cell line, and a human premonocytoid cell line using a liposome-mediated transfer technique. The DQ alpha and DQ beta genomic clones were isolated from a DR2 DQw1 and a DR3 DQw2 phage library, respectively. The pSV2-Neo gene was introduced as a selection marker with both DQ alpha and DQ beta. The resultant transfected cells were able to bind several HLA class II monoclonal antibodies. In addition, these cells were found to be efficient in stimulating peripheral blood lymphocyte proliferation under MLR-like conditions, implying a role for HLA-DQ molecules in HLA-D typing differences.

Animals↗

PubMed1987

Cardiac alpha 1 and beta adrenoceptors in rabbits: effects of dietary sodium and cholesterol.

To investigate the effects of dietary sodium and cholesterol on alpha 1 and beta adrenoceptors in hearts, male Japanese white rabbits were treated with either deoxycorticosterone acetate (DOCA) (50 mg/week sc) plus 1% saline in drinking water, frusemide (10 mg/2 days im), or cholesterol enriched diet (2%, w/w) for eight weeks. Using myocardial membrane preparations, characteristics of alpha 1 and beta adrenoceptors were assessed by a radioligand binding assay using 3H-prazosin and 125I-iodocyanopindolol (125I-CYP) as radioactive ligands respectively. Although the treatment with DOCA and salt induced a small but significant increase in the mean arterial blood pressure, other treatments did not affect blood pressure. None of these interventions affected body weight, ventricular weight, ratio of ventricular weight to body weight, or protein yield of membrane preparations. Neither the number nor the affinity of cardiac alpha 1 adrenoceptors (Bmax 15.1(1.7) fmol X mg protein-1, KD 0.63(0.13) nmol X litre-1 for controls) was affected by any of the treatments given. In contrast to alpha 1 adrenoceptors, the number of beta adrenoceptors (Bmax) decreased significantly from 109.9(9.6) fmol X mg protein-1 for controls to 54.8(5.2) and 52.7(6.9) for rabbits treated with DOCA salt and cholesterol respectively. KD values of beta adrenoceptors for 125I-CYP decreased significantly with cholesterol treatment from 22.5(2.5) to 13.6(2.7) pmol X litre-1. Salt depletion produced by frusemide administration did not affect either the number or the affinity of beta adrenoceptors. These results suggest that changes in the sensitivity of tissues to catecholamines induced by the administration of DOCA salt and cholesterol enriched diet are due to alterations in beta adrenoceptors in the heart.

Animals↗

PubMed1987

Bacterial synthesis of recombinant alpha-human atrial natriuretic polypeptide.

The high-level synthesis of alpha-human atrial natriuretic polypeptide hormone in Escherichia coli has been achieved based on the idea that the yield of a small, basic and unstable polypeptide, such as the natriuretic polypeptide, would be improved by fusion with an appropriate protective polypeptide to construct a neutral fused polypeptide. We prepared an expression vector, pCLaHtrp3t, coding a neutral polypeptide containing 130 amino acid residues in which the polypeptide hormone was fused to a newly designed protective polypeptide through lysine as an enzymatically cleavable residue. The fused polypeptide was synthesized at the high level of 32% of total cellular proteins and at 4.7 X 10(6) molecules per single cell. It was recovered as cellular insoluble fraction and purified to homogeneity. For the isolation of the peptide hormone from the resultant fused polypeptide, Achromobacter protease I, a lysine-specific endopeptidase was used, because it has sufficient activity even in 8 M urea. The recombinant natriuretic polypeptide was indistinguishable from native alpha-human atrial natriuretic polypeptide as regards amino acid sequence as well as biological activity.

Amino Acid Sequence↗

PubMed1987

Inter- and intra-pathologist variability in histologic diagnoses of lung cancer.

To estimate variability and reliability in histologic diagnosis (Dx) of lung cancers, lung cancer preparations were divided into eight equal sets and diagnosed independently by an eight-man pathology panel. Majority Dx (Dx affirmed by more than 4 panelists) was regarded as the consensus Dx of each cancer. The consensus rate of each panelist ranged from 78.8% to 96.1% with an average of 89.4%. The consensus rates were not significantly different among the panelists. Relatively high inter-pathologist agreement was observed in squamous cell carcinoma, adenocarcinoma, and small cell carcinoma. However, regarding large cell carcinoma, there was occasional disagreement among the panelists. Forty-seven cancers were reexamined by the same panelists, with no preliminary announcement, 7 months after the first examination to study the intra-pathologist agreement. The rate of the intra-pathologist agreement ranged from 76.6% to 93.3%. Dx of large cell carcinoma was the most intra-changeable. It was concluded that the histologic Dx of large cell carcinoma was the most inter- and intra-changeable, and the most frequent dissenting Dx from it was poorly differentiated squamous cell carcinoma.

Adenocarcinoma↗

PubMed1987