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Biomedical subjects

T Ofuji

Publications and source records attributed to T Ofuji.

At least 55 records · Page 3Linked to original sources

A different distribution of corticotropin releasing factor and arginine vasopressin contents in the hypothalamic nuclei after estrogen administration.

The distribution of corticotropin releasing factor (CRF) and arginine vasopressin (AVP) in hypothalamic nuclei were examined in control and estrogen-treated female rats. CRF activity was measured using monolayer cultured rat anterior pituitary cells and AVP by radioimmunoassay. Hypothalamic nuclei were punched out according to the method of Palkovits. The distribution of CRF activity in 5 different hypothalamic nuclei was similar to that of AVP in intact female rats. CRF activity in hypothalamic nuclei, pituitary ACTH content and plasma ACTH levels in estrogen-treated rats were not significantly different from those in control rats. However, significant elevation of AVP content was observed in the supraoptic and paraventricular nuclei of estrogen-treated rats. These results indicate that CRF and AVP are distributed in similar hypothalamic nuclei, but that they are not identical.

Adrenocorticotropic Hormone↗

A perifusion method for examining arginine vasopressin (AVP) release from hypothalamo-neurohypophyseal system.

A perifusion method has been developed using rat hypothalamo-neurohypophyseal system (HNS) or neural lobe to investigate the control mechanism of arginine vasopressin (AVP) release. A specific radioimmunoassay (RIA) for AVP was developed to measure AVP in perifusion medium employing anti-AVP serum which was obtained by immunizing rabbits. At a final dilution of 1/12,000, the antiserum showed less than 0.66 and 0.01% cross reactivity with lysine-vasopressin and oxytocin, respectively. But it did not cross reacted with other peptide hormones. The lowest detectable level of vasopressin was 0.5 pg/tube. The intra-assay coefficient of variation averaged 10.4%. The dilution curve of perifused medium was well paralled to the standard curve of AVP assay. AVP release from HNS or neural lobe gradually declined to the stable level in 90-120 min after the initiation of perifusion. Good repeatability of the AVP release from neural lobe was recognized by repeated stimulation with 10 min perifusion of 60 mM KCl at every 60 min. HNS released AVP in dose related manner to the osmotic challenge of sodium or glucose, and AVP release was stimulated from HNS by prostaglandin E2, but not by dopamine. These results show that the perifusion methods using AVP-RIA is a useful method to examine the AVP release from HNS or neural lobe.

Animals↗

Cathodic isozyme of serum creatine kinase in a case of stomach cancer complicated by disseminated intravascular coagulation.

A rare isozyme of serum creatine kinase (CK) migrating cathodic to CK-MM on electrophoresis was found in a 30-year-old male with stomach cancer complicated by disseminated intravascular coagulation leading to massive upper gastrointestinal bleeding and marked anemia. Serum CK activity rose to a maximum of 374 U/l without detectable CK-MB isoenzyme. The patient was also characterized by a marked increase in serum lactate dehydrogenase (all isozymes elevated) and by preferential leakage of mitochondrial aspartate aminotransferase and glutamate dehydrogenase, indicating the presence of extensive tissue damage involving mitochondria. Skeletal muscle mitochondria were considered the most likely source of the additional CK isozyme.

Adenocarcinoma↗

[The effect of gamma-oryzanol on rat pituitary hormone secretion (author's transl)].

gamma-oryzanol (gamma-OZ), a ferulic acid ester of triterpene alcohol, was investigated with regard to its effect on pituitary LH, GH, prolactin and TSH secretion in normal male (M) and ovariectomized female (OVX) rats. gamma-OZ showed a suppressive tendency of LH by a single intravenous injection and also markedly reduced the LH release induced by LHRH when compared with only vehicle-dosed control groups in M and OVX rats. Serum prolactin release induced by TRH was markedly suppressed by 6 days pretreatment with gamma-OZ in OVX rats. These data suggest that gamma-OZ is a potent inhibitor of LH release and may be a weak inhibitor of prolactin in rats.

Animals↗

Stimulatory effects of gamma-aminohydroxybutyric acid (GABOB) on growth hormone, prolactin and cortisol release in man.

Healthy male volunteers injected subcutaneously with 200 mg L-GABOB showed no significant changes in plasma GH, prolactin and cortisol levels. On the other hand, an intrathecal injection of 300 mg D, L-GABOB to cerebrovascular patients caused significant increases in plasma GH, prolactin and cortisol levels at 60 min after injection. These results indicate that GABOB may elicit the secretion of GH, prolactin and ACTH via the central nervous system.

Adrenocorticotropic Hormone↗

Immunoreactive dog C-peptide level in the pancreatic vein.

C-peptide immunoreactivity (CPR) levels were measured in dog superior pancreaticoduodenal vein using synthetic dog C-peptide and its antiserum. The basal CPR level was approximately twice as high as the basal immunoreactive insulin (IRI) level on a molar basis. Glucose (10 mg/kg/min) or arginine (250 mg/kg/min) infusion for 5 min into the superior pancreaticoduodenal artery caused a prompt, parallel increase in IRI and CPR. IRI and CPR were closely equimolar at peak secretions. One bolus administration of synthetic neurotensin (10 microgram/kg) into the same artery produced a mild hyperglycemic response and biphasic IRI and CPR responses at 30 min in the vein. The IRI and CPR increases were closely equimolar during the first phase of secretion, but during the second peak a larger increase was found in CPR than IRI. Upon infusion of synthetic substance P (50 ng/kg/min) for 30 min, IRI and CPR concentrations showed a parallel and closely equimolar fall. These results indicate that insulin and C-peptide were released from beta cells in equimolar concentrations.

Animals↗

Characteristics of antibody to denatured DNA in sera of patients with systemic lupus erythematosus and other rheumatic diseases.

Antibody to native (n-)DNA and denatured (d-)DNA were detected simultaneously and quantitatively in patients who had systemic lupus erythematosus (SLE) and other rheumatic diseases by the Millipore Filter method. In a group of patients who had SLE, 94% had antibody to both n-DNA and d-DNA; 6% had antibody to d-DNA only; serum that had antibody to n-DNA was not found. On the other hand, some of the patients who had progressive systemic sclerosis, dermatomyositis, polymyositis, and Sjøgren's syndrome had antibody to d-DNA only. In order to estimate the participation of anti-d-DNA antibody to lupus nephritis, patients who had SLE were classified into two groups according to immunofluorescent glomerular stainings. In a group of patients whose sera had lumpy or granular stainings, the sera reacted predominantly with n-DNA. In contrast, in the other group of patients whose sera had mesangial or linear glomerular stainings, the sera had antibodies reactive with d-DNA predominantly. These difference of reactivity between the two groups were statistically significant (P less than 0.02). The results suggest that the antibody to d-DNA is less relevant to the severity of lupus nephritis. in the evaluation of disease activity and prognosis of patients who have SLE, it will be of value to estimate the nature of anti-DNA antibodies.

Antibodies, Antinuclear↗

Molecular sieve in renal glomerular and tubular basement membranes as revealed by electron microscopy.

Bovine glomerular basement membrane (GBM) was isolated and purified according to a modification of Spiro's method. Rat and bovine tubular basement membranes (TBM) were isolated and purified by sonic disruption or by the method of Carlson et al. Electron microscopic studies on the ultrastructure of GBM and TBM were performed after negative staining with 1% phosphotungstic acid solution, pH 7.3. When negatively stained, GBM and TBM were seen as fragments varying in size. The surface of the membranes showed a characteristic felt-like or spongy appearance. At higher magnification, GBM and TBM showed a fine meshwork composed of strands and pores which three-dimensionally resembled a crystal lattice. Pores were fairly uniform in size and shape. They were round, oval or polygonal in shape. Some of the pores were elongated to form short straight or bent channels. Strands were also uniform in diameter and surrounded a pore or channel. For an average of 50 pores, the long dimension was 3.1 +/- 0.6 nm and the short dimension 2.5 +/- 0.3 nm in bovine GBM, 3.8 +/- 1.2 and 2.5 +/- 0.7 nm in bovine TBM, and 4.9 +/- 1.5 and 2.8 +/- 0.6 nm in rat TBM, respectively. The strand was 1.8 +/- 0.3 nm in diameter in bovine GBM, 2.5 +/- 0.6 nm in bovine TBM and 3.7 +/- 0.7 nm in rat TBM for an average of 50 strands. The diameters of the pores were less than or close to the short axis of an albumin molecule. It was concluded that renal GBM and TBM were molecular sieves composed of pores and strands.

Animals↗

Concomitant increases in serum growth hormone and hypothalamic somatostatin in rats after injection of gamma-aminobutyric acid, aminooxyacetic acid, or gamma-hydroxybutyric acid.

gamma-Aminobutyric acid (GABA; 50 or 500 microgram/10 microliter) was injected into the right lateral ventricle of urethane- or pentobarbital-anesthetized male rats. The animals were decapitated 15 min after injection. Serum GH and hypothalamic somatostatin (SRIF) concentration were measured by specific RIAs. Intraventricular GABA caused a dose-related increase in GH and SRIF. In another study, aminooxyacetic acid (5 or 20 mg) was injected ip into urethane-anesthetized rats. Aminooxyacetic acid at 20 mg produced a significant increase in both serum GH and hypothalamic SRIF. Furthermore, 12.5 mg gamma-hydroxybutyric acid (GHB) injected ip into urethane- or pentobarbital-anesthetized rats elicited a significant increase in both serum GH and hypothalamic SRIF. Pretreatment with 20 mg L-dopa produced decreases in the GHB-induced serum GH increase and in hypothalamic SRIF in pentobarbital-anesthetized rats. These results show that GABA and GHB stimulated GH secretion, which was accompanied by increased hypothalamic SRIF. Thus, the GH release induced by GABA or GHB may be partly involved in inhibiting the release of hypothalamic SRIF. As the GHB-induced GH release was inhibited by L-dopa, the stimulatory effect of GHB on GH secretion might be mediated by inhibition of the dopaminergic mechanism.

Acetates↗

Cytophilic antithyroglobulin antibody and antibody-dependent monocyte-mediated cytotoxicity in Hashimoto's thyroiditis.

Antithyroglobulin (anti-Tg) antibodies cytophilic for human monocytes were detected in the serum of 30 of 45 patients with Hashimoto's thyroiditis using the passive rosette technique. These antibodies conferred on normal monocytes the ability to form rosettes with Tg-coated erythrocyres (E-Tg) in vitro. The percentage of E-Tg rosette-forming monocytes was correlated with serum anti-Tg antibody titers measured by tanned sheep red cell hemagglutination. Most serum cytophilic activities were recovered in the immunoglobulin G fraction and were not affected by heating to 56 C for 30 min or ultracentrifugation at 105,000 X g for 60 min. Passive E-Tg rosette formation by monocytes was immunologically specific and was inhibited by the addition of small amounts of free Tg into the medium but was not inhibited by the addition of normal human serum. The anti-Tg antibody-armed monocytes became cytotoxic against Tg-coated chicken erythrocytes and lysed target erythrocytes by an extracellular mechanism. It was suggested that monocytes might be armed by cytophilic antibodies in vivo, since monocytes of patients with Hashimoto's thyroiditis showed increased E-Tg binding (rosette formation) relative to monocytes from control subjects. These findings support the possible pathogenetic involvement of monocytes in human autoimmune thyroiditis.

Animals↗