Biomedical subjects

A Shibata

Publications and source records attributed to A Shibata.

At least 667 records · Page 37Linked to original sources

PubMed1981

Von Willebrand disease associated with familial thrombocytopenia and increased ristocetin-induced platelet aggregation.

Two cases of von Willebrand disease (vWD) associated with familial thrombocytopenia were reported. The proband (daughter) and her father showed thrombocytopenia with large platelets and decreased von Willebrand factor activity (VIIIR:WF). Factor VIII procoagulant activity (VIII:C) and factor VIII-related antigen (VIIIR:AG) were normal, but both patients revealed an increased ristocetin-induced platelet aggregation and a qualitative abnormality of the factor VIII protein, which was characterized by fast electrophoretic mobility of VIIIR:AG and an abnormal elution of factor VIII-related activities on Sepharose 2B. DDAVP was hemostatically effective even in this thrombocytopenic patient undergoing a dental extraction.

Adult↗

PubMed1981

Is glucagon present in the human gastric fundus?

The presence of pancreatic type glucagon in the fetal and adult human gastric fundus was examined by radioimmunoassay and by an indirect immunofluorescence technique using specific antiserum against pancreatic glucagon. Although pancreatic type glucagon-containing cell (glucagon-positive cell) were demonstrated in the fetal gastric fundus in 16th, 18th, 23rd and 29th week's gestation, they were not detected in the adult gastric fundus. This immunohistochemical finding was supported by radioimmunoassay study for glucagon in gastric fundus in which there was 52 pg/mg of glucagon in the fetal gastric fundus at 20th week's gestation while glucagon was negligible in the adult gastric fundus. The findings, therefore, suggest that glucagon-positive cells in the human gastric fundus may play an important role in the maintenance of fetal life. Moreover, one fourth of glucagon-positive cells in the fetal gastric fundus reached the gut lumen with their cytoplasmic processes. In view of the finding that none of the canine glucagon-positive cells in the gastric fundus had contact with the gut lumen, the morphological feature of glucagon-positive cells in the human, fetal gastric fundus suggests that the function of glucagon-positive cells in the human, fetal gastric fundus may be somewhat different from that in other mammals.

Adult↗

PubMed1981

Comparison of the responses in the nomifensine test with hyperprolactinemia due to prolactin-secreting pituitary tumors and nonprolactin-secreting hypothalamic tumors.

It has recently been proposed that nomifensine (Nom) administration discriminates those patients with PRL-secreting pituitary tumors from those who have hyperprolactinemia due to other causes. In the present study, this test was performed on 12 presumed functional hyperprolactinemic subjects, 9 patients with surgically proved PRL-secreting pituitary adenoma (6 microadenoma and 3 macroadenoma), and 7 patients with surgically proved non-PRL-secreting hypothalamic tumors (3 craniopharyngioma, 3 suprasellar germinoma, and 1 suprasellar ependymoma). The Nom test suppressed the plasma PRL level to below 60% of the basal level in all 12 women with presumed functional hyperprolactinemia, but did not alter plasma PRL levels in the patients with PRL-secreting pituitary adenoma or hypothalamic tumor. This evidence confirms that the test is, at least in part, able to discriminate those individuals with PRL-secreting pituitary adenoma from those without, regardless of the size of the tumor. However, the test is not capable of distinguishing between hyperprolactinemia due to PRL-secreting pituitary tumors and that due to non-PRL-secreting hypothalamic tumors. A lack of response to Nom is not necessarily due to the presence of a PRL-secreting tumor, and may be related to dysfunction to the hypothalamic-pituitary system.

Adenoma↗

PubMed1981

Circulatory state of patients on chronic hemodialysis.

In 16 patients on chronic hemodialysis, the cardiac catheterization was performed. They had received the hemodialytic treatment for 41 months in the average. All but two cases had cardiothoracic ratio above 50%. It was 58 +/- 7% in all. The laboratory data, body weight, or the interdialytic body weight change was comparable with those of other patients with normal heart size. Pericardial effusion was denied by echocardiographic study. Cardiac index and the left ventricular stroke work index were higher than normal; 4.7 L/min/m2, and 85 +/- 31 g.m/m2 respectively. Cardiac index was higher than 3.9 L/min/m2 in 11 patients and left ventricular stroke work index was above 68 g.m/m2 (= mean value of control). The pulmonary artery wedge pressure was 16 +/- 6 mmHg and abnormally high in six patients (greater than 15 mmHg). The pulmonary artery wedge pressure was found to be correlated with the cardiac work (r = 0.53, p less than 0.02), and with the cardiothoracic ratio (r = 0.64, po less than 0.02). The present study revealed a circulatory abnormality of pulmonary congestion which may be brought by an excessive load upon the heart in the renal failure patients A further increase in the cardiac work by aggravation of anemia, retention of body fluid, or the elevation of blood pressure may easily result in an acute pulmonary edema. The reduction of the load by vasodilator may be useful for the relief of the acute rise of the pulmonary artery wedge pressure as suggested in the study of a small group in the present paper.

Blood Pressure↗

PubMed1981

The histaminergic mechanism of neurotensin-induced glucagon release from isolated rat pancreatic islets.

Isolated rat pancreatic islets were preincubated in a medium with 16.7 mM glucose and incubated with 5.5 mM glucose. Both histamine (100 microM) and neurotensin (100 nM) stimulated glucagon release from the isolated islets, but not insulin release. The stimulation of glucagon release occurred in the presence of 10 and 100 nM neurotensin, while the release of insulin was inhibited in the presence of 1 and 10 nM neurotensin. The neurotensin-induced glucagon release was completely inhibited by 1 mM metiamide, an histamine H2-receptor antagonist, added to the incubation medium and not inhibited by 1 mM diphenhydramine, an histamine H1-receptor antagonist. The results indicate that the histaminergic mechanism, including the H2-receptor system, may be involved in neurotensin-induced glucagon release from the endocrine pancreas.

Animals↗

PubMed1981

Immunohistological demonstration of ACTH-like immunoreactivity in the foetal adrenal medulla in the 23rd week of gestation.

By an indirect immunofluorescence technique and silver impregnation, cells reacting with anti-1-18 ACTH antiserum were demonstrated in the foetal adrenal medulla only in the 23rd week of gestation. They were not found in the foetal adrenal glands before the 23rd week or after 29th week and after birth. The result was confirmed by immunohistological examination using anti-1-18ACTH rabbit IgG purified by affinity chromatography. No cells in the foetal adrenal medulla in the 23rd week of gestation were stained positively by using anti-beta-MSH and anti-beta-endorphin antisera. This finding suggested, therefore, that the synthetic mechanism of ACTH-like immunoreactivity in the foetal adrenal glands was different from that in the pituitary. In view of the findings that some phaeochromocytoma contained ACTH-like immunoreactivity, the present study suggested that the origin of the phaeochromocytoma congested that the origin of the phaeochromocytoma containing ACTH-like immunoreactivity may be the cells of the foetal adrenal medulla in about the 23rd week of gestation.

Adrenal Medulla↗

PubMed1981

Stroke volume estimated at aortic root in M-mode echocardiography.

A noninvasive method for the determination of stroke volume which can be applicable even to a heart contracting asymmetrically is desired. The momentum of blood ejected from heart will be divided into 2 forms; the one is that of blood running away distally and the other is the momentum of the aortic root. SV is estimated by an equation; SVa0 = kXD2XVao1/2XAOT, where D is the diameter of the aortic root, Vao is the mean velocity of the systolic movement of anterior wall, and AOT is the duration of the valve opening of the aortic leaflets. A good correlation was found between SVao and SV measured by the thermodilution method (r = 0.85, p less than 0.001). Since the parameters used in the present method are not affected directly by the mode of cardiac contraction; symmetrical or asymmetrical, it may be useful to determine SV in man.

Adult↗

PubMed1981

The non-specific binding of thermally denatured DNA by healthy human sera in Farr assay with or without addition of dextran sulfate and calcium chloride.

A non-specific DNA binding by human sera was measured in 60 male and female healthy subjects in different ages. Farr assay using thermally denatured mouse embryo [3H]DNA proved a high DNA binding level of 47.9 +/- 5.8% (mean +/- S.D.) on an average of these sera. The addition of dextran sulfate and CaCl2 significantly decreased the mean binding value to 14.7 +/- 4.8% and 6.5 +/- 3.2%, respectively. No significant difference was observed between men and women, or between any age groups from twenties to sixties. The measurement of complement activity in the serum gave no evidence for the participation of complement in the non-specific DNA binding.

Adolescent↗

PubMed1981

Differentiation of specific DNA binding activity of SLE sera from non-specific binding by an addition of dextran sulfate and calcium chloride to the Farr assay system.

A new method for differentiation of specific DNA-binding by human sera from non-specific binding was evaluated with sera from patients with systemic lupus erythematosus in different stages of the disease. An addition of dextran sulfate or calcium chloride to Farr's radioimmunoassay mixture reduced non-specific binding of thermally denatured [3H]DNA of the patient sera without much effect on the specific binding. The measurement of DNA-binding value by the sera in these addition systems provides accurate information with regard to the pathophysiological state of the disease.

Adolescent↗

PubMed1981

Neurotensin and substance P and dumping syndrome.

To investigate the pathophysiological relation between releases of gut hormones and dumping syndrome, plasma radioimmunoassayable neurotensin, substance P, glucagon-like immunoreactivity (GLI), insulin and blood sugar were measured in both gastrectomized patients and control subjects after 50 g oral glucose tolerance tests. Remarkable rises of radioimmunoassayable neurotensin and GLI were found in all gastrectomized patients, but not in control subjects. In contrast, plasma radioimmunoassayable substance P responses were not detected in either gastrectomized patients or control subjects. There were three patients with symptoms of dumping syndrome in the early stage of the test. Plasma radioimmunoassayable neurotensin responses in two out of these three were higher than those in other patients, though the other patient with symptoms had the same degree of neurotensin elevation as patients with no symptoms. In view of the pharmacological effects of neurotensin, it could not be ruled out that a part of the early symptoms of dumping syndrome may result from the remarkably enhanced plasma neurotensin release in some patients, although the enhanced neurotensin responses did not always accompany symptoms of dumping syndrome.

Adult↗

PubMed1981

Depression of heart function after angiotensin II infusion in patients on chronic hemodialysis.

The response of heart function to angiotensin II (AT II) was studied in 18 patients on regular hemodialysis. The mean age was 33 years and they had been dialyzed for 55 months in the average. AT II was infused from a large vein and systolic blood pressure was raised by 40 mmHg. Before and after the change in blood pressure, M-mode echocardiogram of left ventricle was recorded. Left ventricular enddiastolic dimension, stroke index and cardiac index were found to be normal except for 9 patients who showed cardiac index above 4.0L/min/m2. No significant change was found in these parameters after the rise of blood pressure by AT II. Control ejection fraction (EF) was slightly but nonsignificantly lower in the patients than the healthy subjects; 0.73 +/- 0.13 vs. 0.80 +/- 0.05. Though significant falls in EF were found in the patient and in the healthy group, the former showed a profound depression of EF to 0.64 +/- 0.10. This value was significantly lower than the value of the latter group; 0.76 +/- 0.04 (p less than 0.01). Since none had overt heart failure, a depression of EF after AT II can be regarded as subclinical abnormality of heart function. AT II will be useful to detect this limited reserve of heart function in patients on regular hemodialysis who may show normal function at rest.

Adult↗

PubMed1981

Antigenic structure of DNA: relatively high inhibitory activity of di- and trideoxyribonucleotide derived from DNase digest on the interaction of thermally denatured DNA with systemic lupus erythematosus sera.

The antigenic determinant of thermally denatured DNA reactive with systemic lupus erythematosus (SLE) sera was examined by hapten inhibition assay. We used oligonucleotides with different chain lengths (2-8) derived from DNase I digests of salmon sperm DNA in Farr's radioimmunoassay with thermally denatured mouse embryo 3H-DNA as antigen, and the effect of dextran sulphate addition to the assay mixture on the inhibitory activity of oligonucleotides was examined. A characteristic oligonucleotide inhibition pattern on DNA binding by SLE sera was observed in the assay system without dextran sulphate. Di-and/or trinucleotide inhibited the binding more effectively than tetra-and/or pentanucleotide. These patterns were also observed in DNA-normal serum interaction. When dextran sulphate was added to the mixture, the inhibition pattern changed; the inhibitory activity of oligonucleotides increased with chain length in both serum groups. The inhibitory potency of di- and trinucleotide was higher on DNA-SLE sera than on DNA-normal sera interaction. The high potency of short-chain oligomers in SLE sera is obviously different from that in experimentally elicited anti-DNA sera suggesting that different mechanism(s) are involved in antibody production in normal individuals and SLE patients.

Adult↗

PubMed1981