Biomedical subjects

Domenica Altavilla

Publications and source records attributed to Domenica Altavilla.

42 records · Page 3Linked to original sources

PubMed2002

The effect of the phytoestrogen genistein on plasma nitric oxide concentrations, endothelin-1 levels and endothelium dependent vasodilation in postmenopausal women.

The phytoestrogen genistein improves endothelial dysfunction in ovariectomized rats through a nitric oxide-dependent mechanism. We investigated whether genistein alters the balance between the nitric oxide products and endothelin-1 and influences endothelium-dependent vasodilation in postmenopausal women. Sixty healthy postmenopausal women were enrolled in the study. A double-blind, placebo controlled, randomized design was employed. After a 4-week stabilization on a standard fat-reduced diet, participants to the study were randomly assigned to receive either genistein (n=30; 54 mg/day) or placebo (n=30). Flow-mediated, endothelium-dependent vasodilation of the brachial artery, plasma nitric oxide breakdown products and endothelin-1 levels were measured at baseline and after 6 months of genistein therapy. The mean baseline level of nitrites/nitrates was 22+/-10 micromol/l and increased to 41+/-10 micromol/ml after 6 months of treatment. The mean baseline plasma endothelin-1 level was 14+/-4 pg/ml and decreased to 7+/-1 pg/ml following 6 months of treatment with genistein. The mean baseline ratio of nitric oxide to endothelin also significantly increased at the end of treatment. Flow-mediated, endothelium-dependent vasodilation of the brachial artery was 3.9+/-0.8 mm at baseline and increased to 4.4+/-0.7 mm after 6 months of treatment. Placebo-treated women showed no changes in plasma nitrites/nitrates, endothelin-1 levels and flow-mediated vasodilation. Genistein therapy improves flow-mediated endothelium dependent vasodilation in healthy postmenopausal women. This improvement may be mediated by a direct effect of genistein on the vascular function and could be the result of an increased ratio of nitric oxide to endothelin.

Brachial Artery↗

PubMed2002

Evidence for a role of nuclear factor-kappaB in acute hypovolemic hemorrhagic shock.

BACKGROUND: In acute hypovolemic shock, a rapid systemic release of the inflammatory cytokine tumor necrosis factor (TNF-alpha) contributes to vascular failure. Nuclear factor kappaB (NF-kappaB) is an ubiquitous rapid-response transcription factor involved in inflammatory reactions and exerts its effect by expressing cytokines, chemokines, and cell adhesion molecules. The purpose of this study was to evaluate the role of NF-kappaB in acute hypovolemic hemorrhagic shock. METHODS: Hemorrhagic shock was induced in anesthetized male rats by intermittently withdrawing blood from an iliac catheter for 20 minutes (bleeding period) until mean arterial blood pressure (MAP) decreased and stabilized within the range of 20 to 30 mm Hg. Two minutes after bleeding was discontinued the rats received tacrolimus (100 microg/kg), an inhibitor of NF-kappaB activation, or its vehicle. We then evaluated survival rate and survival time, liver NF-kappaB activation by means of electrophoretic mobility shift assay, liver IkappaBalpha protein in the cytoplasm, hepatic TNF-alpha messenger RNA expression, plasma TNF-alpha, arterial blood pressure, and the contractile response of aortic rings to phenylephrine. RESULTS: Rats that underwent hemorrhagic shock died 28+/-2 minutes after bleeding was discontinued, experienced marked hypotension (MAP, 20-30 mm Hg), and had enhanced plasma levels of TNF-alpha (218 +/- 28 pg/mL 20 minutes after bleeding was discontinued). Aortas taken 20 minutes after bleeding was discontinued in rats that underwent hemorrhagic shock showed marked hyporeactivity to phenylephrine (1 nmol/L-10 micromol/L) compared with aortas harvested from sham shocked rats. Rats that underwent hemorrhagic shock also had increased levels of TNF-alpha messenger RNA in the liver. Furthermore, electrophoretic mobility shift assay showed that liver NF-kappaB binding activity increased in the nucleus, and Western blot analysis suggested that the levels of inhibitory IkappaBalpha protein in the cytoplasm decreased. Tacrolimus (100 microg/kg, administered 2 minutes after bleeding was discontinued) inhibited the loss of IkappaBalpha protein from the cytoplasm and prevented NF-kappaB binding activity in the nucleus. Moreover, tacrolimus increased survival time (118 +/- 7 minutes; P <.01) and survival rate (vehicle = 0 and tacrolimus = 90% 240 minutes after bleeding was discontinued), reverted the marked hypotension, decreased liver messenger RNA for TNF-alpha reduced plasma TNF-alpha (35 +/- 6 pg/mL), and restored the hyporeactivity to phenylephrine to control values. CONCLUSIONS: Our results suggest that acute blood loss (50% of the estimated total blood volume during a 20-minute period) causes activation of NF-kappaB and that tacrolimus, by inhibiting this transcription factor, protects against acute hypovolemic shock.

Acute Disease↗

PubMed2002

Effects of atorvastatin treatment on sICAM-1 and plasma nitric oxide levels in hypercholesterolemic subjects.

This study investigated the behavior of soluble intercellular adhesion molecule-1 (sICAM-1) and serum nitric oxide (NO) products, nitrite/nitrate (NO2-/NO3-), in subjects with primary hypercholesterolemia (HCh) without other risk factors and atherosclerosis. The effect of a short-term cholesterol-lowering treatment with atorvastatin, an HMG-CoA reductase inhibitor, on the levels of sICAM-1 and NO2-/NO3- were also investigated. After 4 weeks of placebo administration, 40 HCh (15 males and 25 females) were randomized in 2 groups: 20 subjects (atorvastatin group) received 10 mg/day of atorvastatin and the remaining 20 (placebo group) continued to take placebo. At baseline and after 4 and 12 weeks of atorvastatin or placebo administration, serum sICAM-1 and NO2-/NO3-levels were evaluated. The basal levels of these parameters were compared with those of 20 healthy subjects (C), matched for sex and age. Hypercholesterolemic subjects showed sICAM-1 and NO2-/NO3- basal values that were higher (331.7 +/- 60.3 ng/mL vs. 202.3 +/- 32.3 ng/mL, p<0.001) and lower (10.4 +/- 2.5 micromol/L vs. 20.7 +/- 4.4 micromol/L, p<0.01) than controls. No correlation between sICAM-1 or NO products and plasma cholesterol values was found, whereas there was an inverse correlation between sICAM-1 and NO2-/NO3- levels. Atorvastatin administration significantly decreased sICAM-1 and increased NO2-/NO3- levels, however these changes were not correlated with the reduction of plasma cholesterol. These data support the hypothesize that patients with HCh with no signs of arterial lesions, may have latent atherosclerosis, expressed as an increase of sICAM-1 and decrease in NO product levels. An improvement in the levels of these parameters after a short-time treatment with atorvastatin was also demonstrated.

Adult↗

PubMed2002

Effects of genistein and hormone-replacement therapy on bone loss in early postmenopausal women: a randomized double-blind placebo-controlled study.

The natural isoflavone phytoestrogen genistein has been shown to stimulate osteoblastic bone formation, inhibit osteoclastic bone resorption, and prevent bone loss in ovariectomized rats. However, no controlled clinical trial has been performed so far to evaluate the effects of the phytoestrogen on bone loss in postmenopausal women. We performed a randomized double-blind placebo-controlled study to evaluate and compare with hormone-replacement therapy (HRT) the effect of the phytoestrogen genistein on bone metabolism and bone mineral density (BMD) in postmenopausal women. Participants were 90 healthy ambulatory women who were 47-57 years of age, with a BMD at the femoral neck of <0.795 g/cm2. After a 4-week stabilization on a standard fat-reduced diet, participants of the study were randomly assigned to receive continuous HRT for 1 year (n = 30; 1 mg of 17beta-estradiol [E2] combined with 0.5 mg of norethisterone acetate), the phytoestrogen genistein (n = 30; 54 mg/day), or placebo (n = 30). Urinary excretion of pyridinoline (PYR) and deoxypyridinoline (DPYR) was not significantly modified by placebo administration either at 6 months or at 12 months. Genistein treatment significantly reduced the excretion of pyridinium cross-links at 6 months (PYR = -54 +/- 10%; DPYR = -55 +/- 13%; p < 0.001) and 12 months (PYR = -42 +/- 12%; DPYR = -44 +/- 16%; p < 0.001). A similar and not statistically different decrease in excretion of pyridinium cross-links was also observed in the postmenopausal women randomized to receive HRT. Placebo administration did not change the serum levels of the bone-specific ALP (B-ALP) and osteocalcin (bone Gla protein [BGP]). In contrast, administration of genistein markedly increased serum B-ALP and BGP either at 6 months (B-ALP = 23 +/- 4%; BGP = 29 +/- 11%; p < 0.005) or at 12 months (B-ALP = 25 +/- 7%; BGP = 37 +/- 16%; p < 0.05). Postmenopausal women treated with HRT had, in contrast, decreased serum B-ALP and BGP levels either at 6 months (B-ALP = -17 +/- 6%; BGP = -20 +/- 9%; p < 0.001) or 12 months (B-ALP = -20 +/- 5%; BGP = -22 +/- 10%; p < 0.001). Furthermore, at the end of the experimental period, genistein and HRT significantly increased BMD in the femur (femoral neck: genistein = 3.6 +/- 3%, HRT = 2.4 +/- 2%, placebo = -0.65 +/- 0.1%, and p < 0.001) and lumbar spine (genistein = 3 +/- 2%, HRT = 3.8 +/- 2.7%, placebo = -1.6 +/- 0.3%, and p < 0.001). This study confirms the genistein-positive effects on bone loss already observed in the experimental models of osteoporosis and indicates that the phytoestrogen reduces bone resorption and increases bone formation in postmenopausal women.

Alkaline Phosphatase↗

PubMedDate not supplied

Effects of genistein on hot flushes in early postmenopausal women: a randomized, double-blind EPT- and placebo-controlled study.

OBJECTIVE: We evaluated and compared the effects of the phytoestrogen genistein, estrogen-progestogen therapy (EPT), and placebo on hot flushes and endometrial thickness in postmenopausal women. DESIGN: Ninety healthy, postmenopausal women, 47 to 57 years of age, were randomly assigned to receive for 1 year continuous EPT (n = 30; 1 mg 17beta-estradiol combined with 0.5 mg norethisterone acetate), the phytoestrogen genistein (n = 30; 54 mg/day), or placebo (n = 30). Endometrial safety was evaluated by intravaginal ultrasounds at baseline, 6 and 12 months. RESULTS: By comparison with placebo, daily flushes reduced significantly by a mean of 22% (95% CI: -38 to -6.2; P < 0.01) after 3 months, by a mean of 29% (95% CI: -45 to -13; P < 0.001) after 6 months, and by a mean of 24% (95% CI: -43 to -5; P < 0.01) after 12 months of genistein treatment. Flush score decreased by a mean of 53% (95% CI: -79 to -26; P < 0.001) after 3 months, by a mean of 56% (95% CI: -83 to -28; P < 0.001) after 6 months, and by a mean of 54% (95% CI: -74 to -33; P < 0.001) after 12 months of EPT, as compared with placebo. No side effect was observed on the uterus of the participants. CONCLUSIONS: The present study confirms that genistein might have positive effects on hot flushes without a negative impact on endometrial thickness and suggests a future role of this phytoestrogen as a strategically therapeutic alternative in the management of postmenopausal symptoms.

Double-Blind Method↗

PubMedDate not supplied

Effects of AT1 receptor antagonist losartan on sICAM-1 and TNF-alpha levels in uncomplicated hypertensive patients.

This study was designed to determine whether the levels of soluble intercellular adhesion molecule-1 (sICAM-1) and tumor necrosis factor-alpha (TNF-alpha) were elevated in subjects with uncomplicated hypertension who presented with no other risk factors or evidence of athero-sclerosis. The effects of administration of an angiotensin type-1 antagonist (losartan) on the serum concentrations of these molecules were also examined. Twenty hypertensive (HT) subjects (12 men and 8 women, mean age 49.1 +/-7.2 years) without other risk factors or cardiovascular disease received placebo for 4 weeks. The patients were then treated with losartan (50 mg/day) for 24 weeks. After 4, 12, and 24 weeks of losartan treatment, sICAM-1 and TNF-alpha levels were measured. The same parameters were measured in 20 normotensive control subjects (C), matched for sex and age. HT had sICAM-1 and TNF-alpha basal values higher than C (respectively 351.7 +/-97.4 vs 201.6 +/-32.3 ng/mL, p<0.001 and 31.8 +/-2.4 vs 15.3 +/-2.2 pg/mL, p<0.001). There was a positive correlation between sICAM-1 and TNF-alpha levels, but no correlation in HT between the average diastolic and systolic blood pressure (clinic and ambulatory monitoring) and the sICAM-1 or TNF-alpha levels was observed. Losartan treatment caused a significant decrease of sICAM-1 levels at the end of the first month of treatment (300.2 +/-64.4 ng/mL, p<0.05), but the values reverted to the basal levels at the following time points. No variation of TNF-alpha levels during losartan treatment was observed. These results show that patients with uncomplicated mild essential hypertension presented with high plasma ICAM-1 and TNF-alpha concentrations. Although all the patients were responsive to the antihypertensive treatment with losartan, their plasma concentrations of TNF-alpha were not modified, and sICAM-1 concentrations decreased only for a short period of time. This suggests that in uncomplicated hypertension other factors besides the blood pressure modulate the endothelial inflammation.

Adult↗