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Biomedical subjects

K Totsune

Publications and source records attributed to K Totsune.

69 records · Page 4Linked to original sources
PubMed1991

Immunoreactive endothelin in urine of patients with and without diabetes mellitus.

Immunoreactive (ir)-endothelin (ET) in urine was studied with a radioimmunoassay in patients with diabetes mellitus (DM) and non-DM diseases including endocrine disorders, primary glomerular diseases, autoimmune diseases, and hematological malignancies. Twenty-four-hour excretions (mean +/- SEM) of ir-ET were 8.0 +/- 0.9 pmol/day in the DM group (n = 13) and 9.5 +/- 1.2 pmol/day in the non-DM group (n = 51). No significant differences among DM and other disease groups were noted with respect to 24-h ir-ET excretion. Reverse-phase high-performance liquid chromatography of a normal urine extract revealed a major peak eluting later than ET-1. Gel chromatography revealed a single major peak in a smaller molecular weight (MW) region in normal urine and an additional peak in larger MW region in a urine extract from a DM patient. Urinary ir-ET consists of at least two components which may be metabolites of ET or ET precursors in plasma or peptides derived from the kidney.

Adolescent↗
PubMed1991

Immunoreactive endothelin in pheochromocytomas.

The presence of endothelin (ET) in tumor tissue and plasma of patients with pheochromocytoma was studied by radioimmunoassay. Immunoreactive (ir-) ET concentrations in 12 pheochromocytomas ranged from 66 to 253 fmol per gram wet tissue (gwt) (146 +/- 20 fmol/gwt, mean +/- SEM). These values were not significantly higher than tissue ir-ET concentrations of two primary aldosteronism (66 and 132 fmol/gwt) and three normal adrenal glands (71-120 fmol/gwt) (0.05 less than p less than 0.1). However, tumor tissue ir-ET concentrations in six of the 12 pheochromocytomas were higher than 132 fmol/gwt (the upper value of the control tissues). Sephadex G-50 column chromatography and reverse-phase high-performance liquid chromatography of pheochromocytoma tumor extracts showed a major peak eluting at an identical position to synthetic ET-1. Plasma ir-ET concentrations of pheochromocytomas (1.4 +/- 0.9 fmol/ml, n = 17) were not significantly different from those of patients with essential hypertension (1.0 +/- 0.7 fmol/ml, n = 20) and normal subjects (1.0 +/- 0.4 fmol/ml, n = 18) (0.05 less than p less than 0.1). This study has shown that high concentrations of ET-1 are present in tumor tissues of 50% of pheochromocytomas.

Adrenal Gland Neoplasms↗
PubMed1990

A highly sensitive method for determining both Mn- and Cu-Zn superoxide dismutase activities in tissues and blood cells.

A highly sensitive method for determining the superoxide dismutase (EC 1.15.1.1) in various tissues and blood cells is described. This method involves inhibition of a cypridina luciferin analog that is chemiluminescence dependent upon O2- generated by hypoxanthine-xanthine oxidase. Manganeous superoxide dismutase, which is sensitive to sodium dodecyl sulfate, was determined and calculated by subtraction of superoxide dismutase activity in tissue extract treated with this detergent (Cu-Zn superoxide dismutase) from that in untreated tissue extract (total superoxide dismutase). Both Mn- and Cu-Zn superoxide dismutase activities were expressed as equivalent nanograms of bovine erythrocyte superoxide dismutase per milliliter. Sensitivity limits of the chemiluminescence methods with 2-methyl-6-(p-methoxyphenyl)-3,7-dihydroimidazo[1,2-alpha]pyraz in-3-one and 2-methyl-6-phenyl-3,7-dihydroimidazo[1,2-alpha]pyrazin-3-one as cypridina luciferin analogs were 1 ng and 2-3 ng of superoxide dismutase/ml, respectively.

Animals↗
PubMed1989

Detection of immunoreactive endothelin in plasma of hemodialysis patients.

Two types of radioimmunoassay (RIA) methods for measuring endothelin (ET) in human plasma were developed. One was an extraction procedure using a Sep-Pak C18 cartridge, the other being a direct method. By the extraction method, plasma ET levels were lower than the detectable limit (7 pg/ml) in normal subjects and elevated in hemodialysis patients. The absolute values obtained via the direct method were 20-times higher than those from extraction. Gel-filtration experiments revealed that this discrepancy was mainly due to immunoreactive (IR-) endothelin-like substances of high molecular mass near 11.6 kDa (large IR-ET). Extraction of the peptide by the C18 cartridge could eliminate interference by large IR-ET and is important in the accurate measurement of ET concentrations in plasma.

Adult↗
PubMed1986

Plasma concentrations of atrial natriuretic peptide in various diseases.

Using a radioimmunoassay for atrial natriuretic peptide (ANP) we studied plasma concentrations of immunoreactive ANP in order to investigate the pathophysiological role of ANP in patients with various diseases. Plasma ANP levels were elevated in patients with congestive heart failure (394 +/- 260 pg/ml, n = 8) and chronic renal failure (219 +/- 86 pg/ml, n = 11). In patients undergoing hemodialysis plasma ANP levels were markedly high and decreased after hemodialysis from 433 +/- 166 pg/ml to 204 +/- 92 pg/ml (n = 11). ANP was removed from blood to dialysate (21 +/- 13 pg/ml of dialysate, n = 6, dialysate flow: 500 ml/min). Plasma ANP level was conversely correlated with creatinine clearance (r = -0.812, p less than 0.001) in patients with renal diseases (n = 29). In patients with atrial fibrillation, pace maker implantation, lung disease, chronic glomerulonephritis, nephrotic syndrome, essential hypertension, liver disease and cerebrovascular disease, plasma ANP levels were not significantly different from those in normal subjects (70 +/- 32 pg/ml, n = 28). These results suggest that ANP may be a circulating hormone playing pathophysiological roles in congestive heart failure and chronic renal failure.

Adult↗
PubMedDate not supplied

Porcine brain natriuretic peptide-like immunoreactivity in rat tissues.

The presence of immunoreactive porcine brain natriuretic peptide in rat tissues was studied with a specific radioimmunoassay for porcine brain natriuretic peptide-26. The cross-reactivity of the antiserum used was less than 0.001% with rat atrial natriuretic peptide, rat brain natriuretic peptide-32 and rat brain natriuretic peptide-45. Immunoreactive porcine brain natriuretic peptide was detectable in various tissues of the rat, and high concentrations of immunoreactive porcine brain natriuretic peptide were found in the brain and cardiac atrium, with the highest level in the hypothalamus (159 +/- 30 fmol/gram wet tissue, mean +/- SEM, n = 4). Reverse phase high performance liquid chromatography showed that the immunoreactive porcine brain natriuretic peptide of the whole brain and heart extracts eluted mainly at an identical position to synthetic porcine brain natriuretic peptide-26. These findings indicate that porcine brain natriuretic peptide-like substance, distinct from rat brain natriuretic peptide, is present in high concentrations in the rat brain and cardiac atrium.

Animals↗
PubMedDate not supplied

Human brain natriuretic peptide-like immunoreactivity in human brain.

The presence of immunoreactive human brain natriuretic peptide in the human brain was studied with a specific radioimmunoassay for human brain natriuretic peptide-32. This assay showed no significant cross-reaction with human alpha atrial natriuretic peptide, porcine brain natriuretic peptide or rat brain natriuretic peptide. Immunoreactive human brain natriuretic peptide was found in all 5 regions of human brain examined (cerebral cortex, thalamus, cerebellum, pons and hypothalamus) (0.6-6.7 pmol/g wet weight, n = 3). These values were comparable to the concentrations of immunoreactive alpha atrial natriuretic peptide in human brain (0.5-10.1 pmol/g wet weight). However, Sephadex G-50 column chromatography showed that the immunoreactive human brain natriuretic peptide in the human brain eluted earlier than synthetic human brain natriuretic peptide-32. These findings suggest that human brain natriuretic peptide is present in the human brain mainly as larger molecular weight forms.

Aged↗
PubMedDate not supplied

Pituitary adenylate cyclase activating polypeptide (PACAP)-like immunoreactivity in pheochromocytomas.

Pituitary adenylate cyclase activating polypeptide (PACAP) is a novel hypothalamic peptide consisting of 38 amino acids [PACAP(1-38)] with a potent stimulatory action on adenylate cyclase in rat pituitary. The presence of immunoreactive (IR-) PACAP in the tumor tissue of pheochromocytomas was studied by radioimmunoassay and immunocytochemistry. The antibody to PACAP was raised in a rabbit injected with a peptide containing amino acids 28-38 of PACAP. This antibody showed no significant cross-reactivity with either PACAP(1-27) or vasoactive intestinal polypeptide. The tumor tissue concentrations of IR-PACAP(1-38) were 0.5-57.5 pmol/g wet weight (n = 13) (24.5 +/- 22.4 pmol/g wet weight, mean +/- SD), while those in the normal adrenal glands were 3.58 +/- 2.02 pmol/g wet weight (n = 7) and those in the adrenal cortical tumors were 5.58 +/- 2.02 pmol/g wet weight (n = 6). The IR-PACAP(1-38) concentrations in 7 out of 13 pheochromocytomas exceeded 18 pmol/g wet weight. Sephadex G-50 column chromatography revealed that the IR-PACAP(1-38) in extracts of pheochromocytomas eluted in both the positions of PACAP(1-38) and a larger molecular weight. Reverse-phase high performance liquid chromatography of the tumor extracts revealed a peak in the position of PACAP(1-38) and at least four other peaks. Immunocytochemistry of pheochromocytomas showed numerous immunoreactive cells. The immunostaining was abolished by absorption of the antiserum with synthetic PACAP(1-38). These findings indicate that multiple forms of IR-PACAP(1-38) are present in pheochromocytomas.

Adrenal Gland Neoplasms↗
PubMedDate not supplied

Melanin-concentrating hormone in the human brain.

The presence of human melanin-concentrating hormone (MCH) was studied in the human brain by radioimmunoassay and immunocytochemistry. Immunoreactive MCH concentrations in the human brain ranged from 0.07 to 19.7 pmol/g wet weight. High performance liquid chromatography of the hypothalamus showed a large immunoreactive peak in the position of human/rat MCH, which was eluted 9 min later than that of salmon MCH. Free-floating sections (40 microns) of the hypothalamus were immunostained. Positive MCH immunostaining was found in perifornical, tuberomammillary, and posterior nuclei. Numerous MCH-immunoreactive nerve fibers were observed throughout the hypothalamus. The presence of high concentrations of MCH in the human brain, in particular in the hypothalamus, suggests that MCH is a neurotransmitter, a neuromodulator, or a neurohormone in man.

Aged↗
PubMedDate not supplied

Long-term CaCO3 treatment of chronic hemodialysis patients: an attempt to prevent aluminum osteopathy.

Long-term CaCO3 treatment of chronic hemodialysis patients was studied. Single doses of CaCO3 were given to 25 patients, 23 of whom had been receiving Al(OH)3 before the study. When predialysis serum calcium (Ca) rose to greater than 5.5 mEq/L, CaCO3 was reduced and Al(OH)3 was administered again. Eighteen months later, serum phosphate (P) was well controlled, and predialysis serum P was less than 6.5 mg/dl in 14 patients given CaCO3 alone. Alkaline phosphatase (ALP) levels significantly decreased, and serum aluminum was remarkably lowered in patients who had discontinued Al(OH)3. In patients who resumed Al(OH)3, ALP levels rose after Al(OH)3 administration. Although levels of c-PTH did not change in CaCO3 treated patients, six patients with poor control of serum P before the study showed a significant decrease in c-PTH. These data indicate that CaCO3 is an effective P binder that stops the progression of silent osteopathy, presumably caused by oral intake of Al(OH)3, and may ameliorate these changes. However, further effort will be necessary to develop means to control serum Ca, because long-term use of CaCO3 induced hypercalcemia in half the patients.

Adult↗