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Biomedical subjects

M Mano

Publications and source records attributed to M Mano.

At least 55 records · Page 3Linked to original sources
PubMed1992

Trans-repressor activity of nuclear glycosaminoglycans on Fos and Jun/AP-1 oncoprotein-mediated transcription.

Heparin blocks the phorbol ester-induced progression of nontransformed cells through the G0/G1 phase (Wright, T.C., L.A. Pukac, J.J. Castellot, M.J. Karnovsky, R.A. Levine, H.-Y. Kim-Park, and J. Campisi. 1989. Proc. Natl. Acad. Sci. USA. 86: 3199-3203) or G1 to S phase (Reilly, C. F., M. S. Kindy, K. E. Brown, R. D. Rosenberg, and G. E Sonenshein. 1989. J. Biol. Chem. 264:6990-6995) of the cell cycle. Cell cycle arrest was associated with decreased levels of stage-specific mRNAs suggesting transcriptional regulation of cell growth. In the present report, we show that heparin selectively repressed TPA-inducible AP-1-mediated gene expression. Heparin-induced trans-repression was observed in primary vascular smooth muscle cells, as well as in the transformed HeLa cell line and in nondifferentiated F9 teratocarcinoma cells. Inhibition of AP-1-mediated trans-activation occurred with heparin and pentosan polysulfate but not with chondroitin sulfate A or C. Heparin-binding peptides or heparitinase I addition to nuclear lysates of heparin-treated cells allowed enhanced recovery of endogenous AP-1-specific DNA binding activity. We propose a model in which nuclear glycosaminoglycans play a trans-regulatory role in altering the patterns of inducible gene expression.

Animals↗
PubMed1992

Potassium accelerates urinary sodium excretion during salt loading without stimulating atrial natriuretic polypeptide secretion.

1. Effects of potassium (K) supplementation (100 mEq/day) on urinary sodium (Na) excretion and on the secretion of atrial natriuretic polypeptide (ANP) during salt loading (350 mEq/day) were studied in 12 healthy salt-resistant normotensives under strictly controlled metabolic ward conditions. 2. Urinary volume and Na excretion on the first day of the high salt period (HSP) were significantly greater in the K-supplemented group (KG) than in the control group (CG). 3. There was a significant gain in bodyweight after salt loading in both groups, with a significantly greater gain in CG on the second day of HSP. Haematocrit decreased significantly during salt loading in both groups, the degree of which was significantly greater in CG. 4. Plasma norepinephrine decreased significantly during salt loading in both groups, the degree of which was significantly less in KG than in CG. A significant increase in plasma ANP was observed in CG on and after the second day of HSP, while a significant increase in plasma ANP was observed on the fifth day of HSP in KG. 5. These findings indicate that K supplementation accelerates diuresis and natriuresis, resulting in moderate suppression of volume expansion induced by salt loading and that this accelerated diuresis and natriuresis is not a result of the action of ANP.

Adult↗
PubMed1992

International cooperative study on the relationship between dietary factors and blood pressure: a preliminary report from the Cardiovascular Diseases and Alimentary Comparison (CARDIAC) Study. The CARDIAC Cooperative Study Research Group.

1. To investigate the epidemiological relationship of dietary factors to blood pressure (BP) and major cardiovascular diseases, we carried out the international cooperative Cardiovascular Diseases and Alimentary Comparison (CARDIAC) Study, which so far involves 48 centers in 20 countries as of August 1991. From each population, 100 men and 100 women aged 50-54 years were randomly selected for BP measurement, 24-h urine collection, blood tests, and medical interview. Various biological markers of diets from urine and blood were analyzed centrally in the Izumo CARDIAC center. 2. Cross center analysis using simple linear regression revealed strong significant correlations of body mass index (BMI) to systolic BP (SBP; p < 0.01) and diastolic BP (DBP; p < 0.001) in men. 24-h urinary sodium (Na) excretion in men also showed significant correlations with SBP (p < 0.05) and DBP p < 0.05) even after controlling for the effect of BMI (SBP; p < 0.05, DBP; p < 0.05). 3. Within center analysis using multiple linear regression implied that BMI and Na strongly adversely affect BP, whereas magnesium may have beneficial influence on BP. 4. Multicolinearities among 24h urinary sodium, calcium, and urea nitrogen were noted in men.

Body Mass Index↗
PubMed1992

Ethnic differences in salt sensitivity: genetic or environmental factors?

1. The CARDIAC study, a world-wide cross-sectional epidemiological study on the relationship between alimentary factors and cardiovascular diseases, provided the initial evidence of ethnic differences in salt sensitivity; this was because despite much less urinary sodium excretion in Tanzania than in Brazil and the Japanese, the prevalence of hypertension was relatively higher in Tanzania than in the latter two populations. 2. To investigate this difference in salt sensitivity, a standardized clinical experiment was carried out: six to 13 male volunteers were placed on 2500 kcal basal diets containing 3 g salt/day. Eighteen grams of salt were added daily from the sixth to the 11th day in Tanzania and Brazil, while 22 g of salt were added in Japan. 3. Salt loading induced a significant rise in systolic blood pressure (SBP) on the second day of the high salt period (HSP) in Japan, the second and third day of HSP in Brazil, and all days of HSP in Tanzania. 4. Salt sensitivity was seen in 16.7% of the participants in Japan, 36.4% in Brazil and 46.2% in Tanzania. Further analysis of the effect of salt on blood pressure (BP) was carried out using the data from the CARDIAC study by multiple regression analysis. A within-centre comparison of fatty acid was also made. 5. The regression analysis revealed that the relationship of salt and blood pressure is more positively tight in Tanzania than Brazil and Japan after controlling for other confounding variables. Fatty acids in serum phospholipids contain significantly more palmitic acid and showed lower P/S ratios than those from Brazil and Japan.

Adult↗
PubMed1990

Alcohol consumption as a risk factor for high blood pressure from the Cardiovascular Diseases and Alimentary Comparison Study. CARDIAC Cooperative Research Group).

The relationship between alcohol consumption and blood pressure (BP) was studied in 29 centers in 12 countries as part of the International Cooperative Cardiovascular Diseases and Alimentary Comparison (CARDIAC) Study. From each population, 100 men and 100 women aged 50-54 were randomly selected for BP measurement by automated system and for a standardized interview to complete the questionnaire relating to alcohol consumption. In cross-center simple linear regression analysis, mean alcohol consumption calculated from a previous week's drinking did not show a linear association to BP. In within-center multiple linear regression analysis, relationships between high alcohol intake (much greater than 300 g/week) and BP were assessed among 26 centers with high alcohol drinkers after being adjusted for other confounding variables. Positive associations of high alcohol intake with systolic BP (SBP) and diastolic BP (DBP) were noted in 17 and 16 centers, respectively. Thus, high alcohol intake was positively and independently associated with BP in individual subjects.

Alcohol Drinking↗
PubMed1990

Relationship between dietary factors and blood pressure in China. The Sino-Japan CARDIAC Cooperative Research Group.

As part of the international cooperative Cardiovascular Diseases and Alimentary Comparison (CARDIAC) Study, we carried out surveys for the relationship of dietary factors to blood pressure (BP) in 10 areas in China, (Altai, Beijing, Guangzhou, Guiyang, Hetian, Lhasa, Shanghai, Shijiazhuang, Tulufan, and Urumqi). Systolic BP and diastolic BP were significantly positively associated with salt excretion and body mass index. However, 3-methylhistidine divided by creatinine, and taurine divided by urea nitrogen in 24-h urine were significantly negatively associated with both BPs. These results suggest that meat protein intake may beneficially influence BP, whereas salt may adversely affect BP.

Blood Pressure↗
PubMed1990

International cooperative study on the relationship between dietary factors and blood pressure: a report from the Cardiovascular Diseases and Alimentary Comparison (CARDIAC) Study.

To investigate the epidemiological relationship of dietary factors to blood pressure (BP) and major cardiovascular diseases, we carried out the International Cooperative Cardiovascular Diseases and Alimentary Comparison (CARDIAC) Study, which so far involves 45 centers in 20 countries. From each population, 100 men and 100 women aged 50-54 years were randomly selected for BP measurement, 24-h urine collection, and blood test. Various biological markers of diets from urine and blood were analyzed centrally in the Izumo CARDIAC center. In within-center multiple regression analyses, body mass index (BMI) was strongly positively and independently associated with BP. Urine magnesium (Mg) excretion was negatively and independently associated with BP. In cross-center simple regression analyses, systolic and diastolic BP showed significant correlations with BMI (p less than 0.01) and 24-h urinary sodium (Na) excretion (p less than 0.005) in men and significant inverse correlations with urinary 3-methylhistidine (3-MH) divided by creatinine (p less than 0.01 and p less than 0.005, respectively) in men, and were inversely correlated with urinary Mg in women (p less than 0.05). Therefore, Na and BMI adversely affect BP, whereas animal protein and Mg intakes may have beneficial influence on BP.

Amino Acids↗
PubMed1990

Blood pressure levels in the elderly with or without nutritional intervention.

Blood pressure (BP) examination and urine analyses for the assessment of dietary Na, K, and protein intakes were carried out according to the standardized methods for the World Health Organization Cardiovascular Diseases and Alimentary Comparison Study in aged people with or without a longlasting nutritional intervention. Nutritional intervention to reduce salt intake and increase K and protein intakes was effective for BP reduction even in aged people over 65 years.

Aged↗
PubMed1990

The effect of sodium intake on ventricular performance in healthy men.

We analyzed the effects of acute sodium intake on left ventricular performance in 11 healthy normotensive men using Doppler echocardiography. For 2 weeks, they took 2,700-kcal diets containing 6 g and 24 g sodium chloride per day in the low sodium phase (5 days) and in the high sodium phase (5 days), respectively. Blood pressure, urine, hematocrit, and echocardiographic values were measured every day throughout this study. Although a decrease in the serum norepinephrine concentration and an increase in the ejection fraction were noticed in the low sodium phase, there was no significant change in the relation between end-systolic stress and mean velocity of circumference shortening. All subjects also performed a cold pressor test in both phases, and we analyzed the end-systolic stress-volume relation (modified Emax). Modified Emax of the high sodium phase was significantly larger than that of the low sodium phase. As published in previous research on dogs, we consider that this discrepancy at rest may be caused by a dysfunction at the cardiac adrenergic neuroeffector junction in humans, too, and that sodium intake may enhance the change in ventricular contractility by a cold pressor test.

Adult↗
PubMed1990

Failure of propranolol to inhibit the epinephrine-induced enhancement of responses to sympathetic nerve stimulation in the rat mesenteric vascular bed.

Experiments were designed to characterize the nature of the epinephrine-induced potentiation of responses to sympathetic nerve stimulation in the Hooded Wistar rat. The responses to sympathetic nerve stimulation were determined in the isolated perfused mesenteric vascular bed preparation before and after infusion of epinephrine (at 0.27 or 2.7 microM); at the conclusion of the experiment the content of epinephrine in the mesenteric artery was determined. The intraluminal infusion of epinephrine at both high and low concentrations potentiated the responses of the preparation to sympathetic nerve stimulation. Mesenteric artery concentrations of this catecholamine were unchanged at the lower concentration (0.27 microM), but were increased after perfusion of epinephrine at the higher concentration (2.7 microM). The beta adrenoceptor antagonist propranolol (0.5 microM) did not prevent the epinephrine-associated potentiation of responses to sympathetic nerve stimulation, nor did it influence the pressor effects of exogenous norepinephrine. The results suggest that beta adrenoceptors do not play a role in the epinephrine-induced potentiation of responses to sympathetic nerve stimulation in the rat mesenteric vascular bed preparation. This potentiation may, however, be related to a desensitization of presynaptic inhibitory alpha adrenoceptors.

Animals↗
PubMed1988

A new approach to the prevention of hypertensive cardiovascular diseases by controlling the proliferation of vascular smooth muscle cells.

Cholera toxin subunit B suppressed the proliferation of cultured vascular smooth muscle cells from the thoracic aorta of Wistar-Kyoto rats (WKY), stroke-resistant spontaneously hypertensive rats (SHR) and stroke-prone SHR (SHRSP). Since cholera toxin subunit B did not stimulate cyclic AMP accumulation in vascular smooth muscle cells, the effect of cholera toxin subunit B might be due to another mechanism. Cholera toxin subunit B bound to the surface of vascular smooth muscle cells and was rapidly incorporated into them. The morphological structure of vascular smooth muscle cells was transformed from the synthetic type to the non-synthetic type, in which microfilaments and intermediate filaments were abundantly formed, while rough endoplasmic reticulum was decreased after CTB treatment.

Animals↗
PubMed1987

Effects of sulphur amino acids on the development of hypertension and atherosclerosis in stroke-prone spontaneously hypertensive rats.

We investigated the effects on blood pressure of 5% taurine administered prenatally or postnatally via maternal parents in stroke-prone spontaneously hypertensive rats (SHRSP). Prenatal and/or postnatal administration of taurine produced a blood pressure reduction in the offspring until at least 3 months of age. Furthermore, offspring exposed to high concentrations of taurine through the placenta during the prenatal period and also for 1 month after birth via maternal milk, showed a greater reduction in blood pressure than the group given taurine prenatally but not postnatally. The stroke-prone SHR were fed a high-fat cholesterol and low-protein diet containing 1% methionine or with 3% lysine in drinking water, and effects of the dietary amino acids on the development of atherogenesis were investigated. Intake of additional 1% methionine or 3% lysine had marked preventive effects on atherogenesis in the cerebral and mesenteric arteries in SHRSP. Therefore, early dietary intake of sulphur amino acids delays the onset of hypertension and attenuates the development of both severe hypertension and atherosclerosis in SHRSP.

Animals↗
PubMed1987

Catecholamine-induced polyploidization in vascular smooth muscle cells.

Polyploidy formation of vascular smooth muscle cells was observed in vivo by intravenous infusion of norepinephrine or epinephrine in Wistar-Crea rats for 12 days at the rate of 0.02 mumol/hr with an osmotic minipump and in vitro by exposing cultured vascular smooth muscle cells obtained from normotensive Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR) to norepinephrine (10(-7)M to 10(-5)M) in the cultured medium. Infusion in vivo of norepinephrine but not epinephrine increased blood pressure slightly. However, both agents increased significantly the frequency of tetraploidy of smooth muscle cells up to 14.9 +/- 0.6% (mean +/- SE) and 9.2 +/- 0.5% compared with saline (6.5 +/- 0.7%). Exposure in vitro to norepinephrine (10(-6)M) increased the frequency of tetraploidy and octaploidy of smooth muscle cells from SHR up to 14.2% and 2.1%, respectively, compared with nonexposed cells (8.1% and 0.2%). These results appear to indicate that norepinephrine and epinephrine induce polyploidy of smooth muscle cells independently from blood pressure elevation.

Animals↗
PubMed1987

The tarsal tunnel syndrome. Report of two cases of unusual cause.

Since Keck described the tarsal tunnel syndrome (TTS) in 1962, it has been one of the most frequently diagnosed of the entrapment neuropathies. TTS is usually of unknown origin. This is a report of two unusual cases: TTS caused by neurilemmoma in a 33-year-old woman, and TTS caused by subperiosteal ganglion in a 14-year-old girl. The symptoms were relieved, in both instances, with surgical excision.

Adolescent↗
PubMed1986

Increased tissue level of atrial natriuretic polypeptide in the hypothalamus and septum of spontaneously hypertensive rats.

To elucidate the pathophysiological role of atrial natriuretic polypeptide (ANP) in the brain in hypertension, the tissue concentrations and contents of alpha-rat ANP-like immunoreactivity (alpha-rANP-Ll) in the hypothalamus and septum of 4-week or 18-week-old spontaneously hypertensive rats (SHR) were studied using a radio-immunoassay (RIA) for alpha-rANP and compared with those of age-matched Wistar-Kyoto rats (WKY). The concentration and content of alpha-rANP-Ll in these regions of both 4-week and 18-week-old SHR were significantly higher that those of WKY (P less than 0.05). High performance gel permeation chromatography coupled with the RIA showed that the gel filtration profile of alpha-rANP-Ll in SHR was essentially identical to that of WKY. Since the hypothalamus and septum are known to be critical areas for water and electrolyte balance, and blood pressure control, these results suggest that ANP plays a pathophysiological role in these brain regions of SHR.

Animals↗
PubMed1985

Biochemical aspects of salt-induced, pressure-independent left ventricular hypertrophy in rats.

In an attempt to investigate the effect of chronic salt loading on heart size and biochemical composition, sixty 3-month-old male Wistar-Kyoto rats (WKY) were equally divided into two groups: One group was given 1% NaCl in drinking water, and the other group was given tap water as the control. After 7 months, five randomly selected rats from each group were examined for body weight (BW), indirect blood pressure (BP), hematocrit (Hct), and organ weights. Ventricles of the heart, aorta, and mesenteric arteries were biochemically analyzed for collagen (C) and noncollagenous protein NC) and deoxyribonucleic acid (DNA). Although here was no difference between the salt and control groups in BP (129 +/- 3 mmHg vs. 125 +/- 4 mmHg, mean +/- SE), BW (376 +/- 8 g vs. 372 +/- 5 g) and Hct (42.8% +/- 1.0% vs. 44.3% +/- 0.8%), left ventricular weight (857 +/- 19 mg vs. 788 +/- 8 mg) and kidney weight (2.59 +/- 00.9 g vs 2.31 +/- 0.05 g) were both significantly (P less than 0.01) greater in the salt group, whereas the weights of the right ventricle, aorta, and adrenal glands were equal. Biochemical analysis showed significant increase in NC/DNA ratio and total collagen content as well as decreased DNA concentration in the left ventricle of the salt group compared with the control, suggesting hypertrophy rather than hyperplasia of myocardial cells with concomitant activation of collagen synthesis. Since the manner of reactive collagen production appeared different from that reported for spontaneously hypertrophic rats (SHR) or in hypoxia- or aortic constriction-induced cardiac hypertrophy, some unique mechanism may be involved in salt-induced cardiac hypertrophy.

Adrenal Glands↗