PubMed Health⌕ Search

Biomedical subjects

E Venturelli

Publications and source records attributed to E Venturelli.

18 recordsLinked to original sources
PubMed2006

The leukocyte expression of CD36 is low in patients with Alzheimer's disease and mild cognitive impairment.

CD36, a scavenger receptor of class B (SR-B), helps mediate microglial and macrophage response to beta-amyloid fibrils (betaA), and seems to play a key role in the proinflammatory events associated with Alzheimer disease (AD) in many tissues. Peripheral leukocytes express many molecules and multiple receptors which undergo the same regulatory mechanisms as those operative in the brain. Thus, these cells, easily obtainable through peripheral blood sampling, may be used as a tool to investigate changes occurring in inaccessible brain areas. Based on these premises, we investigated the leukocyte expression of CD36 in 70 AD patients and in 30 subjects with mild cognitive impairment (MCI). Results were compared to those of 20 young and 40 age-matched control subjects. Leukocyte expression of CD36 was significantly reduced versus controls in both AD and MCI patients, while in young and old controls there were no age-related changes. Although preliminary, these data indicate that the reduction of CD36 expression in leukocytes is a disease-related phenomenon, occurring since the early stages of AD (MCI). Irrespective of the mechanism(s) underlying such changes, assessment of leukocyte CD36 expression might represent an useful tool to support the diagnosis of AD and to screen MCI patients candidates to develop the disease.

Adult↗
PubMed2005

Isolation and characterization of a virulent Lactobacillus sanfranciscensis bacteriophage and its impact on microbial population in sourdough.

Thirty-five sourdough samples used for sweet and salted Italian baked products were checked for the presence of a virus active on Lactobacillus sanfranciscensis species. One phage, named EV3, was isolated and its phenotypic and genotypic features were investigated. It belonged to the Siphoviridae family (morphotype B1); its life cycle at 25 degrees C lasted 3 h with a burst size of about 30 viral particles per infected cell. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) showed one major structural protein of 35 kDa and four minor proteins. The genome, approximately 32 kb long, was a double-stranded linear DNA molecule with a pac-type system. Phage spreading into sourdough did not adversely affect acidification and volume increase of the dough neither lactobacilli counts; the propagation of viral particles was shown to be hindered. This is the first report of the isolation of a L. sanfranciscensis phage.

Bacteriolysis↗
PubMed2003

Body mass index, serum sex hormones, and breast cancer risk in postmenopausal women.

BACKGROUND: Obesity is associated with increased breast cancer risk among postmenopausal women. We examined whether this association could be explained by the relationship of body mass index (BMI) with serum sex hormone concentrations. METHODS: We analyzed individual data from eight prospective studies of postmenopausal women. Data on BMI and prediagnostic estradiol levels were available for 624 case subjects and 1669 control subjects; data on the other sex hormones were available for fewer subjects. The relative risks (RRs) with 95% confidence intervals (CIs) of breast cancer associated with increasing BMI were estimated by conditional logistic regression on case-control sets, matched within each study for age and recruitment date, and adjusted for parity. All statistical tests were two-sided. RESULTS: Breast cancer risk increased with increasing BMI (P(trend) =.002), and this increase in RR was substantially reduced by adjustment for serum estrogen concentrations. Adjusting for free estradiol reduced the RR for breast cancer associated with a 5 kg/m2 increase in BMI from 1.19 (95% CI = 1.05 to 1.34) to 1.02 (95% CI = 0.89 to 1.17). The increased risk was also substantially reduced after adjusting for other estrogens (total estradiol, non-sex hormone-binding globulin-bound estradiol, estrone, and estrone sulfate), and moderately reduced after adjusting for sex hormone-binding globulin, whereas adjustment for the androgens (androstenedione, dehydroepiandrosterone, dehydroepiandrosterone sulfate, and testosterone) had little effect on the excess risk. CONCLUSION: The results are compatible with the hypothesis that the increase in breast cancer risk with increasing BMI among postmenopausal women is largely the result of the associated increase in estrogens, particularly bioavailable estradiol.

Aged↗
PubMed2003

Effects of dietary intervention on IGF-I and IGF-binding proteins, and related alterations in sex steroid metabolism: the Diet and Androgens (DIANA) Randomised Trial.

OBJECTIVE: To assess the effects of a comprehensive change in dietary composition on endogenous hormone metabolism. The specific aim was to examine whether this intervention could lead to favourable changes in insulin sensitivity, levels of IGF-I and IGF-binding proteins (IGFBPs), and total and bioavailable testosterone and estradiol, that would be expected to reduce breast cancer risk. DESIGN: Randomised dietary intervention study; duration of 5 months. SUBJECTS: From a total of 99 postmenopausal women, who had elevated baseline plasma testosterone levels, 49 women were randomly assigned to the dietary intervention arm and the other 50 to a control group. INTERVENTIONS: Main aspects of the dietary intervention were reductions in the intake of total fat and refined carbohydrates, an increase in the ratio of n-3 over n-6 plus saturated fatty acids, and increased intakes of foods rich in dietary fibre and phytooestrogens. RESULTS: Relative to the control group, women of the intervention group showed a significant reduction of body weight, waist circumference, fasting serum levels of testosterone, C peptide, glucose, and insulin area after glucose tolerance test, and a significant increase of serum levels of sex hormone-binding globulin, IGFBP-1, -2, and growth hormone-binding protein. Serum levels of IGF-I did not change. CONCLUSION: This comprehensive dietary intervention strategy proved to be successful in inducing changes in endogenous hormone metabolism that might eventually result in reduced breast cancer risk. Additional studies are needed to show whether the dietary intervention and related hormonal changes can be both maintained over longer periods, of at least several years.

Aged↗
PubMed2002

Efficacy of a soy rich diet in preventing postmenopausal osteoporosis: the Menfis randomized trial.

OBJECTIVES: To compare the effect of a soy rich diet and hormone replacement therapy (HRT) on the main biomarkers of bone turnover and bone mineral density (BMD) at postmenopausal age. METHODS: 187 healthy asymptomatic postmenopausal women, aged 39-60, were recruited and randomized into a soy rich diet group, a HRT group, and a control group. Bone biomarkers and BMD were evaluated at baseline and after 6 months at the end of the study. RESULTS: Diet is not as effective as HRT in reducing the postmenopausal turnover; however diet stimulates bone osteoblastic activity, as evidenced by significant increase in osteocalcin concentrations. BMD decreases significantly only in the control group, but not in the intervention groups. CONCLUSIONS: Our data suggest that soy products could be effective in reducing the risk of osteoporosis in asymptomatic postmenopausal women, but our findings should be confirmed before recommending the diet as a valid alternative to HRT.

Adult↗
PubMed2002

The effects of a soy rich diet on serum lipids: the Menfis randomized trial.

OBJECTIVE: To assess beneficial effects of a soy rich diet on the main biomarkers of cardiovascular health in menopause, compared with the effects of the hormone replacement therapy (HRT). METHODS: 187 healthy asymptomatic postmenopausal women, aged 39-60, were recruited and randomized into three groups: a soy rich diet group, a HRT group, and a control group. Lipid profile, body mass index, blood pressure, endometrial thickness, uterine artery resistance index (RI), were evaluated in all the participants at the baseline, after 6 months, and at the end of the study. RESULTS: After a 6-month intervention period, the lipid profile in the soy rich diet group showed a favourable outcome, similar to that observed in the HRT group, but compliance to the diet was low. CONCLUSION: Soy products may be used in the prevention of cardiovascular risk in postmenopausal women because of their efficacy in contrasting the negative effects of menopause on the cardiovascular system, but our findings should be confirmed; moreover, suitable strategies to improve the compliance have to be considered.

Adult↗
PubMed1996

Intratumour amount of sex steroids in elderly breast cancer patients. An approach to the biological characterization of mammary tumours in the elderly.

Interest in breast cancer in elderly women is growing as a result of the high frequency of cancer in older age groups. We measured tumour concentrations and circulating levels of testosterone, dihydrotestosterone (DHT) and oestradiol in 50 postmenopausal patients: 26 younger than 70 yr (median, 61.5, range 50-69) and 24 older than 70 yr (median, 74.5, range 70-82). Hormones were measured by radioimmunoassay (RIA) after extraction and separation on celite column chromatography. Intratumour levels of the three steroids were lower in the older than in the younger patients, but the difference was statistically significant only for DHT (P= 0.0126). The decrease in the tumour concentrations of testosterone and DHT in the older group was associated with a slight increase in circulating levels, yielding as final result a statistically significant decrease of the tissue/plasma (T/P) ratio of these hormones. No significant difference was observed between groups for oestradiol levels. The blood levels of testosterone, DHT and oestradiol were significantly correlated in the older group, but not in the younger group. In contrast, the tumour amounts of testosterone and DHT were found to be significantly associated only in the < 70 yr group. We concluded that the hormonal environment in which breast cancer develops is different in younger and older postmenopausal patients, and that the difference mainly concerns the intratumour amounts of androgens, suggesting that the steroids concur in the growth regulation of mammary tumours.

Age Factors↗
PubMed1995

Methods for urinary testosterone analysis.

Urinary testosterone analysis requires a multistep procedure to achieve a good degree of sensitivity and specificity in the dosage. Hydrolysis, extraction, purification and quantification are usually performed in sequence, and several options can be chosen for each of them. After introductory remarks on the applications of urinary testosterone measurement and a short description of the metabolic pathway of the hormone, an overview of the techniques most commonly used in each step is presented. Advantages and disadvantages of each of them are outlined, and a procedure for urinary testosterone analysis is suggested. The procedure consists of: enzymatic hydrolysis with Helix pomatia juice, followed by solid-phase extraction of hydrolyzed urine by a C18 cartridge coupled with an NH2 cartridge and high-performance liquid chromatography cleanup of the extract. Then, quantification can be achieved by gas chromatography or radioimmunoassay.

Chromatography, Affinity↗
PubMed1995

Testosterone, dihydrotestosterone and oestradiol levels in postmenopausal breast cancer tissues.

The ability of breast tumours to synthesize hormones is well recognized, and local production of sex steroids is thought to play a role in breast cancer growth. We measured the intratumour and circulating levels of testosterone, dihydrotestosterone (DHT) and oestradiol in 35 histologically confirmed carcinomatous mammary tissues obtained at breast surgery from 34 postmenopausal patients, age 50-85 years. Intra-tissue steroids were extracted with ethanol:acetone (1:1; v/v), defatted with 70% methanol in water, and extracted with ether. Steroids, from tissue and serum, were separated by partition chromatography on celite columns and were measured by RIA. Intratumour testosterone and DHT concentrations were significantly correlated, after the exclusion of an outlier (rs = 0.71; P = 0.0001). No association was found between oestradiol and either of the two androgens. Mean oestradiol and DHT concentrations were significantly higher in tissue than in blood (P = 0.0001). Mean testosterone levels in tissues did not significantly differ from those measured in blood. Our data suggest that at least a part of intratissue DHT is produced locally from testosterone. The meaning of high oestradiol and DHT levels in cancer tissue still needs to be defined.

Aged↗
PubMed1994

Testosterone levels as a marker of prognosis to goserelin treatment in metastatic breast cancer.

Testosterone levels were measured in blood and urine of 35 premenopausal metastatic breast cancer patients before starting therapy with the gonadotrophin-releasing hormone (GnRH) analogue, goserelin. The aim of the study was to verify the reliability of testosterone measurement as a marker of prognosis. The time interval between starting therapy and progressive disease (time to progression) was chosen to assess prognosis. Univariate and multivariate analysis showed that only urinary testosterone levels were significantly associated with time to progression (Wald test 6.66, P = 0.01 for univariate and Wald test 7.93, P = 0.0049 for multivariate analysis), whereas no association was found for testosterone in blood. A statistical model is proposed to evaluate probability of progressive disease in relation to testosterone values in urine at different times. According to the model, the probability of progression decreases with increasing urinary testosterone values.

Adult↗
PubMed1993

Urinary testosterone as a marker of risk of recurrence in operable breast cancer.

We investigated the role of urinary testosterone levels as a marker of risk of recurrent disease in 113 operable breast cancer patients (70 premenopausal, 43 postmenopausal). Twenty-four-hour urine collections for testosterone measurement were obtained before surgical treatment, between 20-40 days thereafter, and then every 6 months for 5 years. The cutoff values to separate 'high testosterone (A+)' from 'normal testosterone (A-)' were 8.0 micrograms/24 h in premenopause and 4.9 micrograms/24 h in postmenopause. Urinary testosterone levels were considered high when they exceeded the cutoff value in at least 2 of the first 3 measurements (pretreatment, post-treatment, 6 months) of each patient. According to the aforementioned criterion, 33 patients (29.2%) had high testosterone levels, which were associated to axillary node involvement in 16 patients. Thirteen of the latter relapsed during the 5-year follow-up period (5/7 in premenopause, 8/9 in postmenopause). Relapse-free survival (RFS) curves were drawn only for node-positive patients owning to the small number of recurrences observed in the node-negative group. In premenopausal node-positive patients, RFS was significantly different for patients presenting high and normal urinary testosterone levels (77% vs 28%, respectively; logrank test, p < 0.006). In postmenopausal node-positive patients, RFS was also different between the two groups (54% vs 11% in 'high' and 'normal' excretors, respectively) but the difference was not statistically significant. The present findings suggest that urinary testosterone is a prognostic indicator of early breast cancer recurrence in node-positive patients.

Adult↗
PubMed1992

Urinary testosterone measurement by gas chromatography after solid-phase extraction and high-performance liquid chromatography.

A method was developed for the rapid determination of testosterone in urine. The procedure consists of solid-phase extraction (SPE) followed by high-performance liquid chromatographic (HPLC) clean-up before gas chromatographic determination. Recovery was evaluated by adding [3H]testosterone (10(4) cpm) to urine samples; the mean recovery of radioactivity after SPE and HPLC was 82%. Precision was estimated by repeated measurement of testosterone in four different urine samples; the coefficient of variation was 7.9% (95% confidence limits 6.1-11.4%). Accuracy was evaluated by standard addition and dilution assays; a linear relationship was found between the expected and observed values (r2 = 0.982). The method is rapid, effective and suitable for routine analysis.

Chromatography, Gas↗
PubMed1982

Sensitivity to radiations of Mg2+ and (Ca2+ + Mg2+) ATPase activities associated with erythrocyte membrane fragments.

Treatment of disrupted erythrocyte membranes with ionizing radiation induces a partial oxidation of -SH groups (as expected from reported data) and a loss of membrane phospholipids as confirmed by the decrease of membrane amino groups. The resulting disturbance of the membrane assembly strongly affects the membrane bound divalent cation-dependent ATPase activities, possibly by causing the formation of a dead-end enzyme complex unable to complete the ATP splitting cycle.

Adenosine Triphosphatases↗
PubMedDate not supplied

Quantitative analysis of urinary daidzein and equol by gas chromatography after solid-phase extraction and high-performance liquid chromatography.

Daidzein and its main metabolite equol are isoflavone phytoestrogens. Several studies have suggested that intake of an isoflavone-rich diet may prevent hormone-related cancer and estrogen-related disorders (cardiovascular disease, osteoporosis and menopausal symptoms). To better understand the role of isoflavones in preventing such severe disease, several methods have been developed to measure these compounds in biological fluids. However, the analytical procedures to measure isoflavones are often time-consuming and require highly skilled technicians. In this paper we describe a method for urinary daidzein and equol measurement that combines solid phase extraction and HPLC purification before gas chromatographic determination. The specificity of the method was confirmed by the gas chromatography-mass spectrometry technique. The mean recovery of daidzein and equol was 94.6% and 97.0%, respectively. The repeatability of the method was in the range of 2.0-7.4% for daidzein and 1.3-4.9% for equol. A linear relationship between observed and expected values was found in the dilution (r2=0.9983 for daidzein; r2=0.9982 for equol) and addition (r2=0.9984 for daidzein; r2=0.9989 for equol) assays. The method is suitable to measure changes in the urinary excretion of isoflavones and to investigate urinary isoflavonoids as biomarkers of isoflavone exposure.

Chromans↗
PubMedDate not supplied

Evaluation of reactive oxygen metabolites in frozen serum samples. Effect of storage and repeated thawing.

Measuring the free radical activity in serum samples from prospective studies is the best way to investigate the association between oxidative stress and human diseases. Prospective studies require the analysis of serum samples that have often been stored for a long time. Our study was designed to determine the effect of storage at -30 degrees C and -80 degrees C for two years on free radical activity. We analyzed the free radical activity by measuring circulating hydroperoxides in a pool of sera at baseline and after one day, one week, one month and 25 months of storage, using a photometric method (d-ROMs test). Measurements were performed in aliquots thawed only once at each time point and in aliquots frozen and thawed repeatedly over the study period. After two years we observed a small but statistically significant 4% decrease in the hydroperoxide concentration, which was substantially unaffected by storage temperatures and repeated freeze-thaw cycles. We also carried out the d-ROMs test in sera from ten apparently healthy volunteers at 2, 8, 24, and 48 hours after collection and storage at 4 degrees C and did not observe any significant variation. In conclusion, the d-ROMs test is a simple method suitable to evaluate the free radical activity in frozen serum samples after long-term storage.

Adult↗
PubMedDate not supplied

Plant-based diet, serum fatty acid profile, and free radicals in postmenopausal women: the diet and androgens (DIANA) randomized trial.

High calorie and fat consumption and the production of free radicals are two major mechanistic pathways between diet and disease. In this study we evaluated the effect of a plant-based diet poor in animal fat and rich in (n-3) fatty acids on fatty acids of serum phospholipids and on the production of reactive oxygen metabolites (ROMs). One hundred and four healthy female postmenopausal volunteers were recruited and randomized to a dietary intervention or a control group. Dietary intervention included a program of food education and biweekly common meals for 18 weeks. When the intervention and control groups were compared, it was seen that dietary intervention resulted in a significant reduction of saturated fatty acids (-1.5%) and a significant increase in (n-3) fatty acids (+20.6%), in particular docosahexaenoic acid (+24.8%). We observed that arachidonic acid decreased (-7.7%), while (n-6) fatty acids did not, and the (n-3)/(n-6) polyunsaturated ratio increased significantly (+24.1%). As expected, ROMs decreased significantly in the intervention group (-6%). The results indicated that a plant-based diet can improve the serum fatty acid profile and decrease ROMs production. These results suggest that a plant-based diet may reduce the body's exposure to oxidative stress.

Aged↗