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Biomedical subjects

C Bellini

Publications and source records attributed to C Bellini.

At least 55 records · Page 3Linked to original sources
PubMed1998

Higher activity of an aldehyde oxidase in the auxin-overproducing superroot1 mutant of Arabidopsis thaliana.

Aldehyde oxidase (AO; EC 1.2.3.1) activity was measured in seedlings of wild type or an auxin-overproducing mutant, superroot1 (sur1), of Arabidopsis thaliana. Activity staining for AO after native polyacrylamide gel electrophoresis separation of seedling extracts revealed that there were three major bands with AO activity (AO1-3) in wild-type and mutant seedlings. One of them (AO1) had a higher substrate preference for indole-3-aldehyde. This AO activity was significantly higher in sur1 mutant seedlings than in the wild type. The difference in activity was most apparent 7 d after germination, the same time required for the appearance of the remarkable sur1 phenotype, which includes epinastic cotyledons, elongated hypocotyls, and enhanced root development. Higher activity was observed in the root and hypocotyl region of the mutant seedlings. We also assayed the indole-3-acetaldehyde oxidase activity in extracts by high-performance liquid chromatography detection of indole-3-acetic acid (IAA). The activity was about 5 times higher in the extract of the sur1 seedlings, indicating that AO1 also has a substrate preference for abscisic aldehyde. Treatment of the wild-type seedlings with picloram or IAA caused no significant increase in AO1 activity. This result suggested that the higher activity of AO1 in sur1 mutant seedlings was not induced by IAA accumulation and, thus, strongly supports the possible role of AO1 in IAA biosynthesis in Arabidopsis seedlings.

Aldehyde Oxidase↗
PubMed1998

Mutation in the Arabidopsis PASTICCINO1 gene, which encodes a new FK506-binding protein-like protein, has a dramatic effect on plant development.

The pasticcino (pas) mutants of Arabidopsis thaliana are a new class of plant developmental mutants; members of this class show ectopic cell proliferation in cotyledons, extra layers of cells in the hypocotyl, and an abnormal apical meristem. This phenotype is correlated with both cell division and cell elongation defects. There are three complementation groups of pas mutants (pas1, pas2, and pas3, with, respectively 2, 1, and 4 alleles). Here we describe in more detail the pas1-1 allele, which was obtained by insertional mutagenesis. The PAS1 gene has been cloned and characterized; it encodes an immunophilin-like protein similar to the p59 FK506-binding protein (FKBP52). PAS1 is characterized by an FKBP-like domain and three tetratricopeptide repeat units. Although the presence of immunophilins in plants has already been demonstrated, the pas1-1 mutant represents the first inactivation of an FKBP-like gene in plants. PAS1 expression is altered in pas1 mutants and in the pas2 and pas3 mutants. The expression of the PAS1 gene is increased in the presence of cytokinins, a class of phytohormones originally discovered because of their ability to stimulate cell division. These results are of particular relevance as they show for the first time that an FKBP-like protein plays an important role in the control of plant development.

Amino Acid Sequence↗
PubMed1998

Clustering of endothelial markers of vascular damage in human salt-sensitive hypertension: influence of dietary sodium load and depletion.

The contributing role of vascular endothelium in the development of hypertension-related vascular damage is well accepted. Salt-sensitive hypertension is characterized by a cluster of renal, hormonal, and metabolic derangements that might favor the development of cardiovascular and renal damage. To evaluate endothelial involvement in salt-sensitive essential hypertension, plasma levels of several markers of endothelial damage such as endothelin-1 (ET-1), von Willebrand factor (vWf), and soluble (S-) adhesion molecules E-selectin, intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and 24-hour urinary albumin excretion (UAE) were measured in 39 nondiabetic, nonobese, never-treated essential hypertensive patients after intermediate (120 mmol/d), high (220 mmol/d), and low (20 mmol/d) NaCl diets. Patients were classified as salt sensitive (n=18) or salt resistant (n=21) according to their blood pressure responses to changes in dietary NaCl intake. Salt-sensitive hypertensives showed higher plasma ET-1 (P<0.05), vWf (P<0.005), and S-E-selectin levels (P<0.04) and increased UAE (P<0.05) than salt-resistant hypertensives. By contrast, circulating S-ICAM-1 and S-VCAM-1 concentrations were not significantly higher in salt-sensitive (596. 56+/-177.05 ng/mL and 541.06+/-157.84 ng/mL, respectively) than salt-resistant patients (516.86+/-147.99 ng/mL and 449.48+/-158.91 ng/mL, respectively). During the intermediate NaCl diet, plasma ET-1 responses to oral glucose load were greater in salt-sensitive (P<0. 05) than in salt-resistant patients. A marked (P<0.05) hyperinsulinemic response to oral glucose load was evident in salt-sensitive but not salt-resistant patients after each diet. This study shows increased plasma levels of the endothelium-derived substances E-selectin, vWf, and ET-1 in salt-sensitive hypertensives. Our findings support the hypothesis that salt sensitivity is correlated with an increased risk for developing hypertension-related cardiovascular damage.

Adult↗
PubMed1998

The PASTICCINO genes of Arabidopsis thaliana are involved in the control of cell division and differentiation.

The control of cell division by growth regulators is critical to proper plant development. The isolation of single-gene mutants altered in the response to plant hormones should permit the identification of essential genes controlling the growth and development of plants. We have isolated mutants pasticcino belonging to 3 complementation groups (pas1, pas2, pas3) in the progeny of independent ethyl methane sulfonate and T-DNA mutagenized Arabidopsis thaliana plants. The screen was performed in the presence or absence of cytokinin. The mutants isolated were those that showed a significant hypertrophy of their apical parts when grown on cytokinin-containing medium. The pas mutants have altered embryo, leaf and root development. They display uncoordinated cell divisions which are enhanced by cytokinin. Physiological and biochemical analyses show that cytokinins are probably involved in pas phenotypes. The PAS genes have been mapped respectively to chromosomes 3, 5 and 1 and represent new plant genes involved in the control of cell division and plant development.

Adenine↗
PubMed1998

Early activation of vascular endothelium in nonobese, nondiabetic essential hypertensive patients with multiple metabolic abnormalities.

Circulating soluble E-selectin, intercellular adhesion molecule-1 (ICAM-1), and vascular adhesion molecule-1 (VCAM-1) concentrations were evaluated in 93 nonobese essential hypertensive patients, of whom 16 had impaired glucose tolerance and hyperlipidemia (group I); 25 had impaired glucose tolerance (group II); 28 had hyperlipidemia (group III); and 24 had no metabolic abnormalities (group IV). A group of 22 healthy volunteers served as a control group. All groups were without clinical or ultrasound evidence of vascular lesion and were matched for age, sex, and BMI. Endothelial soluble adhesion molecules were measured at baseline, during an oral glucose tolerance test, and after 12 weeks of either enalapril or placebo treatments. Plasma soluble E-selectin, ICAM-1, and VCAM-1 were higher (P < 0.05) in group I and II than in the other groups (group I: E-selectin, 96.1+/-27.1; ICAM-1, 304.0+/-102.1; VCAM-1, 626.1+/-156.2 microg/l. Group II: E-selectin, 88.0+/-18.0; ICAM-1, 268.0+/-84.1; VCAM-1, 594.1+/-140.9 microg/I. Group III: E-selectin, 70.1+/-18.1; ICAM-1, 195.1+/-68.0; VCAM-1, 495.9+/-110.1 microg/l. Group IV: E-selectin, 65.1+/-16.1; ICAM-1, 168.1+/-64.0; VCAM-1, 472.1+/-108.2 microg/l). Soluble adhesins levels were not higher than normal in groups III and IV. Plasma soluble ICAM-1 concentrations increased in group I after glucose administration and were directly correlated with 2-h insulin levels (r=0.648, P=0.007). Compared with placebo, 12 weeks of enalapril treatment significantly (P < 0.0001) reduced soluble E-selectin, ICAM-1, and VCAM-1. Decrements of soluble adhesins were not dependent on enalapril-related blood pressure changes. Therefore, an early endothelial activation was present in essential hypertensive patients with impaired glucose tolerance, regardless of the presence of hyperlipidemia. ACE inhibition counteracted such endothelial activation.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1997

Elevated plasma endothelin-1 levels as an additional risk factor in non-obese essential hypertensive patients with metabolic abnormalities.

Circulating endothelin-1 concentration was evaluated in 93 lean patients with essential hypertension, of whom 16 had impaired glucose tolerance and hyperlipidaemia, 25 had impaired glucose tolerance, 28 had hyperlipidaemia and 24 had no metabolic abnormalities; we also studied 22 control subjects. All groups were age- and sex-matched. Plasma endothelin-1 levels were higher (p < 0.05) in hypertensive patients with impaired glucose tolerance and hyperlipidaemia than in the remaining groups and were directly correlated with fasting insulin levels (r = 0.506, p = 0.045). Therefore, circulating endothelin-1 concentrations are elevated in hypertensive patients with a high-risk profile due to the presence of metabolic abnormalities, and might favour the development of vascular damage.

Cohort Studies↗
PubMed1997

Cristal mutations in Arabidopsis confer a genetically heritable, recessive, hyperhydric phenotype.

A new class of recessive Arabidopsis mutants, designated cristal (cri) has been isolated which display several abnormalities reminiscent of hyperhydric symptoms. These characteristics include translucent and wrinkled cotyledons and leaves, abnormal chloroplast organization, a reduced amount of chlorophyll, a reduced dry weight and a decreased number of palisade cells in the leaves accompanied by an increase of intercellular space, and therefore give a vitreous appearance to the aerial part. The phenotype is also dependent on the culture medium water potential. The cri1 gene was mapped on chromosome 4 close to the DHS1 marker.

Arabidopsis↗
PubMed1997

A comparison of two-dimensional electrophoresis data with phenotypical traits in Arabidopsis leads to the identification of a mutant (cri1) that accumulates cytokinins.

Total proteins extracted from developmental mutants of Arabidopsis thaliana (L.) Heyhn. and from wild-type plants cultivated in the presence of various hormones were analyzed by two-dimensional (2-D) gel electrophoresis. Computer analysis of 2-D gels followed by a statistical treatment of data allowed us to build a phenogram that describes the biochemical distances between the different genotypes. Analysis of the 2-D electrophoresis data allowed us to discriminate mutants in agreement with phenotypical and physiological traits. This biochemical analysis helped us to develop a working hypothesis which led us to show that one developmental mutant (cri1) overaccumulates cytokinins.

Arabidopsis↗
PubMed1997

Endothelin-1 in diabetic and nondiabetic men with erectile dysfunction.

PURPOSE: We evaluated plasma concentration of endothelin-1 in diabetic and nondiabetic men complaining of erectile dysfunction, and the variation of endothelin-1 in cavernous body blood during intracavernous injection of prostaglandin E1. MATERIALS AND METHODS: We evaluated plasma concentrations of endothelin-1 in venous blood of 20 men with erectile dysfunction, 10 with and 10 without diabetes. Plasma concentration of endothelin-1 was also evaluated in the cavernous body blood of the 20 men with erectile dysfunction, during erection induced by intracavernous injection of 10 micrograms prostaglandin E1. A severe vasculogenic component of erectile dysfunction was excluded in all patients. RESULTS: Basal plasma concentration of endothelin-1 in the cubital vein was increased in nondiabetic (1.13 +/- 0.4 pg./ml.) and in diabetic (1.80 +/- 0.2 pg./ml.) patients with erectile dysfunction, compared to control men (0.64 +/- 0.1 pg./ml.) (p < 0.0005 and p < 0.0001, respectively), and in diabetic compared with nondiabetic patients (p < 0.002). No difference and close correlation were observed in the concentration of endothelin-1 in the cavernous body blood evaluated 5 minutes and 30 minutes after injection of prostaglandin E1 (r = 0.89, p < 0.0001, y = 0.98 x + -0.066). The concentration of endothelin-1 in the cavernous body blood evaluated 30 minutes after injection of prostaglandin E1 did not show any difference compared to peripheral venous concentration of the peptide in the 2 patient groups. Concentrations of endothelin-1 in the peripheral vein and the cavernous body blood were not different in patients with a full erection compared with incomplete penis erection after injection of prostaglandin E1 in the cavernous body.

Adult↗
PubMed1997

Sebaceous nevus syndrome: report of two cases.

Sebaceous nevus (SN) syndrome is a neurocutaneous disorder characterized by a distinctive skin lesion in association with epilepsy and mental retardation. In one group of patients, brain lesions may be consequent to vascular abnormalities ("vascular variant"); another group of SN patients presents ipsilateral hemimegalencephaly, gyral anomalies, and facial hemihypertrophy ("neurologic variant" or "SN with hemimegalencephaly"). In the latter group, facial hemihypertrophy does not appear to be a constant feature and was not present in our 2 SN patients with hemimegalencephaly. Considering that about half of the SN patients with hemimegalencephaly described so far do not have facial asymmetry, we suggest the existence of a separate subgroup of SN patients with hemimegalencephaly and without facial hemihypertrophy. In these patients, the only clinical diagnostic clue is a nevus that is barely visible until puberty.

Brain↗
PubMed1997

Elevated plasma and urinary endothelin-I levels in human salt-sensitive hypertension.

1. The behaviour of the potent vasoconstrictive endothelium-derived peptide endothelin-1 was evaluated in salt-sensitive hypertension. 2. Circulating and urinary endothelin-1 levels were evaluated in 30 men (mean age 44.6 +/- 3.1 years) with uncomplicated essential hypertension after three consecutive 2-week periods on an intermediate (120 mmol), low (20 mmol) and high (240 mmol) NaCl diet. On the same occasions, blood pressure was measured to identify salt-sensitive patients (n = 16), i.e. those patients showing a mean blood pressure increase > 10 mmHg when switching from a low to a high NaCl diet, and salt-resistant patients (n = 14), i.e. those who did not show such mean blood-pressure variations. 3. Plasma endothelin-1 levels were higher (P < 0.005) in salt-sensitive than in salt-resistant hypertensive patients after intermediate-, low- and high-NaCl diets. Urinary endothelin-1 excretion was similar in both groups after an intermediate-NaCl diet, whereas it was significantly higher in salt-sensitive than in salt-resistant hypertensive subjects after low (P < 0.002) and high (P < 0.007) NaCl diets. High NaCl intake induced a significant increase in plasma endothelin-1 levels (P < 0.002) as compared with intermediate and low NaCl diet levels in salt-sensitive patients, but did not in salt-resistant subjects. No significant NaCl intake-related variations of urinary endothelin-1 excretion were observed in either group. 4. Salt-sensitive hypertensives are characterized by increased levels of endothelin-1 in both plasma and urine. This fact suggests that blood-pressure sensitivity to NaCl intake could be associated with an increased risk of developing both renal and cardiovascular damage.

Adult↗
PubMed1997

Plasma endothelin-1 levels during transient acute myocardial ischaemia in men: effects of coronary revascularization.

The endothelium-derived peptide endothelin-1 (ET-1) was evaluated in 14 male patients [mean age 52.74 years (SEM 1.10)] affected by coronary artery disease during a bicycle electrocardiographic stress test and dipyridamole echocardiogram. Both tests were performed before and after coronary revascularization. Fourteen healthy male subjects served as controls [mean age 53.21 years (SEM 1.63)]. Baseline plasma endothelin-1 levels were higher (P < 0.0001) in ischaemic patients [1.81 pg mL-1 (0.15, n = 14)] than in control subjects [0.61 pg mL-1 (0.03, n = 14)], but did not increase with exercise in both groups. Similar results were obtained with dipyridamole infusion. Endothelin-1 levels significantly decreased after coronary revascularization [before: mean 1.81 pg mL-1 (SEM 0.15, n = 14); after: mean 1.16 pg mL-1 (SEM 0.11), P < 0.002], without changes in the peptide response to both tests. In conclusion, elevated plasma endothelin-1 concentrations were found in patients with stable angina compared with non-ischaemic subjects. No changes were observed during exercise or dipyridamole infusion in both groups. Coronary revascularization was followed by a significant decrease in plasma endothelin-1 levels.

Adult↗
PubMed1997

Circulating endothelin-1 levels in obese patients with the metabolic syndrome.

We evaluated venous plasma ET-1 concentrations in 18 never-treated obese men (body mass index 31.0 +/- 0.5 kg/m2; age 45.4 +/- 4.3 years) showing the whole features of the above syndrome and 12 control men (age 44.1 +/- 3.6 years). Circulating ET-1 levels were significantly higher in patients than in controls (p < 0.05), and were directly correlated with fasting insulin levels (r = 0.564, p = 0.015) and erythrocyte Na+/Li+ counter-transport activity (r = 0.504, p = 0.033). In conclusion, venous plasma ET-1 levels are elevated in obese men manifesting the whole features of the metabolic syndrome. Due to the biological properties of ET-1, our findings suggest the peptide as a further component of the cluster of cardiovascular risk factors which characterizes this syndrome.

Adult↗
PubMed1997

Increased levels of plasma endothelin-1 in non-insulin dependent diabetic patients with retinopathy but without other diabetes-related organ damage.

Increased levels of endothelin (ET-1), a potent endothelium-derived vasoconstrictive peptide, have been found in plasma from non-insulin dependent diabetic (NIDDM) patients, suggesting that ET-1 might represent a new marker of diabetes-related vascular damage. To elucidate this topic, circulating ET-1 levels were evaluated in 16 NIDDM patients in good metabolic control without either cardiovascular risk factors (obesity, hypertension, smoking, hyperdislipidaemia, etc.) or diabetes-related damage of other districts and in 12 healthy subjects. Retinopathy was assessed by ophthalmological evaluation and its severity determined by Klein criteria. Resulting data showed higher levels of plasma ET-1 in NIDDM patients than in control subjects (0.80 +/- 0.13 vs 0.60 +/- 0.12 pg/mL, p < 0.001). Plasma ET-1 levels were directly correlated with retinopathy degrees in NIDDM patients affected by retinopathy (n = 10; r = 0.368; p = 0.02), and were significantly higher in these latter (n = 10) than in those without retinopathy (n = 6) (0.89 +/- 0.13 vs 0.71 +/- 0.19 pg/mL, p < 0.05). The increased levels of ET-1 could contribute to retinopathy development or, more probably, represent a marker of this diabetes-related complication.

Adult↗
PubMed1997

Elevated albumin excretion in nonmodulating essential hypertensive patients.

Nonmodulating (NM) essential hypertensives are characterized by abnormal renal and aldosterone responses to angiotensin II. Recently, hyperinsulinemia, hypercholesterolemia, and an increased prevalence of family history of hypertension and myocardial infarction have been shown in NM hypertensives. Since an elevated urinary albumin excretion (UAE) has been indicated as a negative prognostic marker for cardiovascular diseases in essential hypertensives, we evaluated UAE in 50 male patients with mild to moderate essential hypertension (mean age 46.3 +/- 4.4 years), characterized as low renin (LR) (n = 14), modulating (M) (n = 20), and NM patients (n = 16) according to their renin profile and ability to modulate the aldosterone response to a graded infusion of angiotensin II. A group of 14 healthy male subjects (mean age 43.3 +/- 3.9 years) served as control. Resulting data showed that NM had significantly higher UAE (30.7 +/- 10.7 microg/min) than controls (11.9 +/- 2.7 microg/min, p < 0.0001), LR (22.1 +/- 8.4 microg/min, p < 0.05), and M patients (19.7 +/- 6.6 microg/min, p = 0.0001) when all fed a 200-mmol NaCl/day diet. On the contrary, differences in UAE disappeared when all subjects were on a low sodium regimen (10 mmol NaCl/day). Compared to LR and M patients, the NM ones also manifested higher low-density lipoprotein cholesterol levels (p < 0.05). Furthermore, these latter and UAE were positively correlated in NM patients (r = 0.579, p < 0.05) but not in the other subgroups. In conclusion, the current study demonstrates elevated UAE in NM patients, suggesting the NM phenotype is combined to an increased cardiovascular risk.

Adult↗
PubMed1997

Age, gender, and non-modulation. A sexual dimorphism in essential hypertension.

The angiotensinogen gene is one of the very few related by linkage analysis to human hypertension, but the linkage has been consistently shown only among males. Moreover, polymorphisms in this gene predict an abnormal renal responsiveness to angiotensin II, a feature of non-modulation, but again, only among males. To pursue these related bridges between genetics and physiology, we evaluated the effects of sex on a second feature of non-modulation, the aldosterone response to infused angiotensin II during low sodium balance. We tested the resultant hypothesis-that non-modulation would be less frequent in women-by conducting identical protocols on 225 hypertensive inpatients (70 women, 155 men). Non-modulation was strikingly less frequent among women (26%; 95% confidence interval, 16% to 37%) than men (49%; 95% confidence interval, 40% to 57% (P = .001). We tested the hypothesis that sex steroids play a role by comparing young, premenopausal women (< 35 years) with women who were perimenopausal (45 to 55 years) and postmenopausal (> 55 years). Among the youngest women, the frequency of non-modulation was only 7%, significantly less than in young men (41%, P = .02). A steady increase in non-modulation frequency accompanied advancing age in women, reaching 47% in those older than 55 years, equal to the fraction of men affected. Age influenced non-modulation frequency in men far less. We conclude that a striking sex difference underlies the non-modulation phenotype and that female sex hormones may confer protection against a genotypic predisposition in women. This "override" of genotype, manifest by a very low frequency of non-modulation in young women, may participate in their known protection against cardiovascular disease.

Adolescent↗