Search PubMed⌕ Search

Biomedical subjects

F Marumo

Publications and source records attributed to F Marumo.

At least 721 records · Page 40Linked to original sources
PubMed1971

Effects of Ca++ and prostaglandin E1 on vasopressin activation of renal adenyl cyclase.

Adenyl cyclase activity was assayed in crude homogenates of the renal cortex, medulla, and papilla of the golden hamster. The specific activity (moles C-AMP/unit of time per mg protein of tissue) of the enzyme under basal conditions, was greatest in papilla, somewhat lower in medulla, and least in cortex. On an absolute scale, the sensitivity to vasopressin was greater in the medullary and papillary than in the cortical homogenates. In addition, at concentrations of 0.1-1.0 mm, CaCl(2) inhibited the enzyme in the order papilla > medulla > cortex. These results imply the existence of distinct differences in the composition of the adenyl cyclase-receptor complex in various parts of the kidney. We proposed that Ca(++) inhibits the core enzyme directly since at the minimally inhibitory concentration (0.1 mm), CaCl(2) reduced to an equivalent extent (a) basal activity, (b) the response to graded doses of vasopressin (0.5 to 50.0 mU/ml) and (c) the response to maximal stimulatory concentrations of NaF (10 mm). Prostaglandin E(1) (PGE(1) = 10(-7)m) had no effect on either basal adenyl-cyclase activity or the response to 10 mm NaF in medullary and papillary homogenates. 7-Oxa-13-prostynoic acid (10(-4)m) similarly had no effect under basal conditions or on stimulation with NaF in medullary homogenates. Both fatty acids, however, inhibited the enzymic response to vasopressin, particularly at low concentrations of the peptide. The straight-chain fatty acid, 11-eicosanoic acid (10(-7)m), was inactive on basal activity or on the response to vasopressin. The possibility that PGE(1) modifies the coupling mechanism between the core enzyme and the hormone-specific receptor is discussed.

Adenylyl Cyclases↗
PubMedDate not supplied

Primary Budd-Chiari syndrome due to complex venous anomalies.

A 35-year-old woman with clinical features of Budd-Chiari syndrome is presented. Abdominal ultrasonography, computed tomography, and venography disclosed that the venous congestion in this patient resulted from complex venous anomalies including azygos-hemiazygos continuation, absent superior hepatic veins, and retroaortic transposition of the left renal vein.

Adult↗
PubMedDate not supplied

Immunohistochemical localization of endothelin in human vascular endothelial cells.

The cellular localization of endothelin (ET), a novel vasoconstrictor peptide, was studied in human vascular tissues by immunohistochemistry. Distinct and diffuse staining for ET-like immunoreactivity was demonstrated in the cytoplasm of vascular endothelial cells, but not in smooth muscle cells or adventitial fibroblasts. The specificity was confirmed by the negative results following immunoabsorption. These findings suggest that human vascular endothelial cells function as an endocrine and/or paracrine cells for ET secretion.

Adult↗
PubMedDate not supplied

Regional distribution of immunoreactive endothelin in rats.

By use of a specific radioimmunoassay for endothelin (ET), the regional distribution of ET-like immunoreactivity (LI) was studied in rats. The antiserum used cross-reacted equally with synthetic porcine and rat ET. Significant amounts of ET-LI are detectable not only in aorta, but also in kidney, lung, heart, liver and central nervous system. Gel chromatography of the tissue extracts revealed size heterogeneity of ET-LI; one major component eluting close to, but slightly larger than standard rat ET and the other minor component with a larger molecular weight. These data indicate that ET-LI is widely distributed throughout the various rat tissues, suggesting its possible involvement in a variety of organ functions.

Animals↗
PubMedDate not supplied

The characteristics of bone turnover in the second decade in relation to age and puberty development in healthy Japanese male and female subjects--Japanese Population-based Osteoporosis Study.

BACKGROUND: There are few studies that clarify the characteristics of bone turnover in children and adolescents. Furthermore, little has been published on changes in urinary CrossLaps(TM) (CTx) in Japanese subjects. AIM: To investigate biochemical markers of bone turnover in subjects, in relation to age and puberty development. SUBJECTS AND METHODS: We measured serum bone specific alkaline phosphatase (B-Alp) and CTx in 1207 Japanese subjects aged 9-18 years. As an indicator of puberty development, the age that pubic hair appeared in males and menstruation started in females was obtained from questionnaires. RESULTS: B-Alp and CTx/Cr (creatinine) had high values before and just after the indicators and was lower thereafter, reaching a plateau in both genders. There was no significant difference in these values in males 5-6 years, or 7 years and more after the appearance of pubic hair. B-Alp and CTx/Cr values 7 years and more after menarche were significantly lower than those 5-6 years after menarche, however the differences were relatively small. CONCLUSIONS: Subjects in the second decade can be divided into three groups: 'before the appearance of pubic hair for males and menarche for females', 'up to and including 3-4 years after them' and '5-6 years and more after them'.

Adolescent↗
PubMedDate not supplied

Long-term use of low molecular weight heparin ameliorates hyperlipidemia in patients on hemodialysis.

Hyperlipidemia is one of the major risk factors for cardiovascular death in long-term hemodialysis (HD) patients. To clarify whether unfractionated heparin (UFH) contributes to the pathogenesis of hyperlipidemia, nine Type IIb, seven Type IV, and 10 normolipidemic patients, who had been dialyzed with 80.7 IU/Kg heparin, were dialyzed with 40 anti-Xa U/kg of low molecular weight heparin (LMWH) (Logiparin, Novo-Nordisk, Gentfe, Denmark) for 6 months. Seven normolipidemic patients were also dialyzed with heparin as controls. Decreases in triglyceride (TG) during HD with LMWH were significantly less than those with heparin. However, lipoprotein lipase activities (LPL) during HD with LMWH and heparin, and those before and after 6 months on LMWH, were no different. During the 6 months on LMWH, serum total cholesterol, TG, and alpha lipoprotein significantly decreased in Type IIb patients but did not change in Type IV. In contrast, beta lipoprotein slightly increased in Types IIb, IV, and normolipidemic patients who were dialyzed with LMWH but was unchanged in the controls. These observations suggest that UFH aggravates hyperlipidemia in patients, but these effects cannot be attributed to depletion of endothelial LPL liberated by UFH.

Adult↗
PubMedDate not supplied

Significance of plasma glutathione determination in patients with alcoholic and non-alcoholic liver disease.

Plasma glutathione levels were determined in 79 patients with various types of liver disease and 18 healthy controls in order to study their significance in the course of liver disease. Plasma was taken at the time of needle liver biopsy. A positive linear correlation was found between plasma and hepatic glutathione concentrations, as has been suggested in experimental animals. In patients with acute viral hepatitis, chronic hepatitis, non-alcoholic liver cirrhosis and alcoholic liver disease, plasma glutathione levels were significantly decreased compared with those in controls. Of importance is the fact that the plasma levels increased after recovery in patients with acute viral hepatitis and after abstinence from alcohol intake in patients with alcoholic liver disease. Determination of plasma glutathione may be valuable in the evaluation of liver disease, particularly in acute viral hepatitis and alcoholic liver disease in which the hepatic content of glutathione is suggested to be decreased. Such patients may be susceptible to oxidative stress and radical-related hepatic injury.

Acute Disease↗
PubMedDate not supplied

Quantitative immunohistochemical analysis of lymphocyte subsets in alcoholic liver disease.

To investigate the role of lymphocytes frequently observed in the parenchyma of alcoholic liver disease (ALD), lymphocytes infiltrating into the liver were stained immunohistochemically with monoclonal antibodies (MoAb) and were quantitatively assessed by a morphometric analysis in 17 patients with ALD and, for comparison in five patients with chronic active hepatitis B (B-CAH). In patients with alcoholic hepatitis, the number of CD8+ lymphocytes in the hepatic lobule was similar to that in patients with B-CAH but was significantly greater than that in alcoholics with hepatic fibrosis (HF). The CD4/CD8 ratio in the hepatic lobule was low in both alcoholic hepatitis and B-CAH compared with that of alcoholic patients with HF. When Mallory bodies (MB) and lymphocytes were simultaneously stained with a specific antibody against MB and MoAb, respectively, only CD3+ and CD8+ lymphocytes were found to have a close contact with MB. These results suggest that in alcoholic hepatitis, hepatocyte necrosis may be partly mediated by immunological mechanisms involving cytotoxic T cells infiltrating into the hepatic lobule.

Biopsy↗
PubMedDate not supplied

Clinical significance of arterial ketone body ratio in chronic liver disease.

BACKGROUND: Arterial ketone body ratio (acetoacetate/3-hydroxybutyrate, AKBR) has been reported to be a useful tool for the estimation of liver functional reserve, but a more recent report has cast doubt on the clinical significance of this redox theory. Furthermore, the effect of a diminution of liver functional reserve on AKBR has not been documented in chronic liver disease. METHODS: AKBR was measured in normal control subjects (n = 10), heavy alcohol drinkers (n = 19), patients with chronic hepatitis (n = 18) and patients with liver cirrhosis (n = 25). RESULTS: Though AKBR was lower in heavy alcohol drinkers (1.66 +/- 0. 82) than in the other noncirrhotic groups (1.97 +/- 0.93 in normal control subjects, 2.25 +/- 1.11 in patients with chronic hepatitis), this discrepancy did not reach a level of significance. AKBR in patients with liver cirrhosis (1.18 +/- 0.52) was significantly lower than that in normal controls (p < 0.01). AKBR in Child's class A, Child's class B, and Child's class C was 1.20 +/- 0.60, 1.07 +/- 0.56, and 1.27 +/- 0.45, respectively, and there were no significant differences among them. CONCLUSION: AKBR may be parallel to liver mitochondrial redox potential and hepatic functional reserve to some extent, but it does not appear to be an accurate parameter for their estimation.

3-Hydroxybutyric Acid↗
PubMedDate not supplied

Acute and chronic effects of hyperosmolality on mRNA and protein expression and the activity of Na-K-ATPase in the IMCD.

We investigated acute and chronic effects of hyperosmolality on mRNA and protein expressions of Na-K-ATPase alpha and beta isoforms and Na-K-ATPase activity in the rat inner medullary collecting duct (IMCD). Incubation of IMCD in hypertonic medium for 30 min reduced the Na-K-ATPase activity by 50%. The Na-K-ATPase activity of dehydrated rats measured in isotonic medium was decreased, and incubation in hypertonic medium did not further decrease the activity. Incubation of IMCD in hypertonic medium for 6 h did not change alpha(1) mRNA. In contrast, dehydration decreased alpha(1) subunit mRNA and protein and beta(1) protein expressions without changing beta(1) mRNA. These data show (1) that acute hyperosmolality decreases Na-K-ATPase activity in IMCD without changing alpha(1) and beta(1) mRNA and (2) that 2 days of dehydration decreased Na-K-ATPase activity by reducing alpha(1) and beta(1) proteins. Thus, the mechanisms for the inhibition of the Na-K-ATPase activity in IMCD is different between acute and chronic exposure to hyperosmolality.

Animals↗
PubMedDate not supplied

Severely impaired urine-concentrating ability in mice lacking the CLC-K1 chloride channel.

To analyze the physiological functions of CLC-K1 in vivo, we generated mice lacking CLC-K1 by targeted gene disruption. Homozygous mutant Clcnk1-/- mice produced approximately 5 times more urine than Clcnk1+/- and Clcnk1+/+ mice. After 24-hour water deprivation, Clcnk1-/- mice became severely dehydrated and lethargic. Intraperitoneal injection of the V2 agonist, deamino-Cys(1), D-Arg(8) vasopressin, induced an increase in urine osmolarity in Clcnk1+/- and Clcnk1+/+ mice from approximately 1,000 to approximately 3,000 mosm/kg H(2)O, whereas the increase in Clcnk1-/- mice was only from approximately 600 to approximately 840 mosm/kg H(2)O, indicating nephrogenic diabetes insipidus in Clcnk1-/- mice. These results clearly established that CLC-K1 plays a major role in the urinary-concentrating mechanisms.

Animals↗
PubMedDate not supplied

Adrenomedullin receptor antagonism by calcitonin gene-related peptide(8-37) inhibits carotid artery neointimal hyperplasia after balloon injury.

Intimal injury by angioplasty results in a series of changes, including smooth muscle cell hyperplasia, that lead to vascular restenosis. Adrenomedullin, a potent vasodilator peptide, has natriuretic effects, and its plasma concentration is elevated in cardiovascular diseases. Adrenomedullin is secreted by endothelial and vascular smooth muscle cells, but its role in neointimal hyperplasia after balloon injury has not been previously described. We investigated the role of endogenous adrenomedullin in neointimal hyperplasia using an in vivo rat model of postinjury vascular restenosis. In the injured rats, bromodeoxyuridine-labeled nuclei in the media of untreated common carotid arteries were increased 2 days after injury, which were suppressed by in vivo treatment with the adrenomedullin receptor antagonist calcitonin gene-related peptide (CGRP)(8-37). Inhibition of neointimal hyperplasia by CGRP(8-37) was distinct at 7 and 14 days, whereas CGRP(1-37) had no effect. The expression of adrenomedullin in the media of both untreated and treated common carotid arteries was elevated at 2 days and further enhanced in hyperplastic intima of untreated common carotid arteries at 7 days. Our findings suggest a novel role for endogenous adrenomedullin in balloon injury-induced restenosis and indicate that CGRP(8-37) may be useful for the prevention of vascular restenosis.

Animals↗
PubMedDate not supplied

Secondary polycythemia associated with multiple myeloma.

A 58-year-old man with polycythemia of more than 8 years duration developed multiple myeloma. Extensive examination indicated his polycythemia to be of a secondary type, but failed to reveal an underlying disorder. To the best of our knowledge, this is the first reported association of multiple myeloma in a patient with definitely-diagnosed secondary polycythemia.

Humans↗