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Biomedical subjects

C Galli

Publications and source records attributed to C Galli.

At least 37 records · Page 2Linked to original sources
PubMed2001

Antiatherogenic components of olive oil.

Olive oil is the principal source of fat in the Mediterranean diet, which has been associated with a lower incidence of coronary heart disease and certain cancers. Olive oil is characterized by a high proportion of monounsaturated oleic acid, but the main peculiarity of extra-virgin oil is the presence of remarkable quantities of phenolic compounds, notably hydroxytyrosol and oleuropein, that provide high stability and strong taste. Recently, several studies have demonstrated that olive oil phenolics are powerful antioxidants, both in vitro and in vivo, and exert additional potent biologic activities that could partially account for the observed cardioprotective effects of the Mediterranean diet.

Coronary Disease↗
PubMed2001

Modeling systematic errors: polychromatic sources of Beer-Lambert deviations in HPLC/UV and nonchromatographic spectrophotometric assays.

It is well established that the use of polychromatic radiation in spectrophotometric assays leads to excursions from the Beer-Lambert limit. This Note models the resulting systematic error as a function of assay spectral width, slope of molecular extinction coefficient, and analyte concentration. The theoretical calculations are compared with recent experimental results; a parameter is introduced which can be used to estimate the magnitude of the systematic error in both chromatographic and nonchromatographic spectrophotometric assays. It is important to realize that the polychromatic radiation employed in common laboratory equipment can yield assay errors up to approximately 4%, even at absorption levels generally considered 'safe' (i.e. absorption <1). Thus careful consideration of instrumental spectral width, analyte concentration, and slope of molecular extinction coefficient is required to ensure robust analytical methods.

Chromatography, High Pressure Liquid↗
PubMed2001

Urinary excretion of olive oil phenols and their metabolites in humans.

We have recently demonstrated, in humans, the bioavailability of hydroxytyrosol (3,4-dihydroxyphenylethanol; HT), one of the major antioxidant components of virgin olive oil. In particular, we reported that this compound is present in lipoproteins involved in atherosclerotic processes and is excreted in the urine mainly as glucuronide-conjugate. The aim of the present study was to elucidate, in humans, the metabolic fate of HT after ingestion of virgin olive oil. After administration of virgin olive oil, 24-hour urine collections of healthy volunteers were prepared for gas chromatography-mass spectrometry analyses in order to identify and quantify HT and its metabolites homovanillic alcohol (HVA1c) and homovanillic acid (HVA). The results indicate that this compound undergoes the action of catechol-O-methyl transferase (COMT), enzymes involved in the catecholamine catabolism, resulting in an enhanced excretion of HVA1c. We also found a significant increase of HVA, indicating an oxidation of the ethanolic residue of HT and/or of HVA1c in humans. The excretion of both metabolites significantly correlated with the dose of administered HT.

Biological Availability↗
PubMed2001

Breastfeeding duration, milk fat composition and developmental indices at 1 year of life among breastfed infants.

The associations of breastfeeding duration and milk fat composition with the developmental outcome at 1 year of age were measured within 44 infants exclusively breastfed for 3 months, out of 95 recruited at birth. Pooled breast milk (hindmilk) of the mothers was analysed at colostrum, 1, 3, 6, 9, and 12 months for total fat and fatty acid content. Infants were examined at 12 months by means of the Bayley test. There was a progressive reduction of the number of breastfed babies after the introduction of solids to 29 (6 months), 17 (9 months) and 10 (12 months). After adjusting for major confounders, infants breastfed for 6 months or longer showed a trend to have an advantage at the Bayley psychomotor developmental index compared to those breastfed >3 and <6 months (95% CI for difference: - 0.6, 13.8; P= 0.07) while the Bayley mental developmental index (MDI) was just 2.1 points higher. Among the milk fat components considered for each time-point, the total fat content at 6 months showed the strongest association with the MDI at 12 months (r=0.59, P=0.001). Prolonging breastfeeding during the weaning process may result in a better developmental performance at 12 months, possibly due to the supply of fats affecting brain composition.

Breast Feeding↗
PubMed2001

Hydroxytyrosol, as a component of olive mill waste water, is dose- dependently absorbed and increases the antioxidant capacity of rat plasma.

Hydroxytyrosol is the most potent phenolic antioxidant of olive oil and olive mill waste water (OMWW) and its biological activities have stimulated research on its potential role in cardiovascular protection. However, evidence of the absorption of OMWW phenolics and on their possible in vivo activity has, until now, never been provided. Three groups male Sprague-Dawley rats were administered 1, 5, or 10 mg/Kg of the OMWW extract, respectively, providing 41.4, 207, and 414 microg/Kg of hydroxytyrosol, respectively. Urine was collected for 24 h and the urinary levels of hydroxytyrosol were quantified by mass spectrometry. Hydroxytyrosol was dose-dependently (R(2) = 0.95) absorbed and excreted in the urines mostly as a glucuronide conjugate. Further, the administration of an hydroxytyrosol-rich OMWW extract (10 mg/kg) to the rats was also associated with an increase of their plasma antioxidant capacity. Future experiments will eventually further clarify its metabolic fate and its in vivo actions.

Animals↗
PubMed2001

Evaluation of the Abbott AxSYM cytomegalovirus (CMV) immunoglobulin M (IgM) assay in conjunction with other CMV IgM tests and a CMV IgG avidity assay.

The measurement of the avidity of cytomegalovirus (CMV) immunoglobulin G (IgG) antibodies has been shown by several investigators to be useful in identifying and excluding primary CMV infections in pregnant women. In this work, we examined the diagnostic utility of reflex testing of CMV IgM-positive specimens from pregnant women by using a CMV IgG avidity assay. The utility of this approach was directly dependent on the sensitivity of the CMV IgM assay employed during the initial screen. The higher initial reactivity rate of the AxSYM CMV IgM assay was necessary in order to detect CMV IgM in specimens containing low-avidity CMV IgG antibodies, indicative of a primary CMV infection, which other CMV IgM assays (Behring, Vidas, Captia, and Eurogenetics) fail to detect in some cases. The use of the AxSYM CMV IgM assay, followed by an avidity test, should result in more accurate diagnosis of CMV infection in pregnant women.

Antibodies, Viral↗
PubMed2001

Statins enhance arachidonic acid synthesis in hypercholesterolemic patients.

BACKGROUND AND AIM: It has been shown that statins enhance arachidonic acid biosynthesis from linoleic acid in vitro, and there is also evidence that statin-treated patients have high plasma and cellular arachidonic acid levels. The aim of this study was to investigate the possible effects of statins on the desaturating steps of arachidonic acid biosynthesis in patients. METHODS AND RESULTS: Plasma polyunsaturated fatty acids (percentages and concentrations), total cholesterol, LDL-cholesterol and triglycerides were measured in three groups of hypercholesterolemic patients before and after treatment with statins or fibrates for about three years, or before and after four months on a low-fat diet. As expected, there was a significant reduction in plasma total cholesterol (-23%) and LDL-cholesterol (-27%) levels in the statin group, and a significant reduction in triglycerides (-29%) and some decrease in total cholesterol (-12%) in the fibrate group; no change was observed in the control group. The selective increase in plasma arachidonic acid levels (in terms of absolute concentration and as a percentage of total fatty acids) was of the same order as the reduction in cholesterol, and the selective increase in the product/precursor ratios for delta 5 desaturation in the statin group indicated that this key step in arachidonic acid synthesis is affected. CONCLUSIONS: Our data show that an increase in arachidonic acid synthesis due to enhanced delta 5 desaturation is a major effect of statin treatment, and has the same order of magnitude as the reduction in plasma cholesterol levels.

Anticholesteremic Agents↗
PubMed2000

Olive oils rich in natural catecholic phenols decrease isoprostane excretion in humans.

This study was undertaken to evaluate, in humans, the antioxidant activity of olive oil phenolics, namely hydroxytyrosol and oleuropein aglycone that share an orthodiphenolic (catecholic) structure. Human volunteers were administered olive oil samples containing increasing amounts of an olive oil phenolic extract that was characterized by gas-chromatography/mass spectrometry. The administration of phenol-rich oils was dose-dependently associated with a decreased urinary excretion of 8-iso-PGF(2alpha), a biomarker of oxidative stress. Also, a statistically significant negative correlation between homovanillyl alcohol (HValc, hydroxytyrosol's major metabolite, formed through the COMT system) and F(2)-isoprostanes excretion was found. Thus, the administration of oil samples with increasing, albeit low, concentrations of orthodiphenolic compounds, namely hydroxytyrosol and oleuropein aglycone, results in a dose-dependent reduction in the urinary excretion of 8-iso-PGF(2alpha). The statistically significant negative correlation between 8-iso-PGF(2alpha) and HValc urinary concentrations suggests that this metabolite better reflects the in vivo activities of hydroxytyrosol.

Adult↗
PubMed2000

Olive phenol hydroxytyrosol prevents passive smoking-induced oxidative stress.

BACKGROUND: Oxidative stress is involved in the onset of several degenerative disorders, and epidemiological studies indicate that a high intake of dietary antioxidants, as in the case of the Mediterranean basin, is protective. Olive mill waste waters (OMWWs) are a byproduct of olive oil production rich in phenolic antioxidants, such as hydroxytyrosol. We tested the effects of a low dose of an OMWW extract in a model of sidestream smoke-induced oxidative stress in rats by evaluating the urinary excretion of 8-iso-prostaglandin (PG) F(2alpha) (iPF(2alpha)-III). METHODS AND RESULTS: An OMWW extract (5 mg/kg, providing 414 microg/kg of hydroxytyrosol) was administered to rats daily for 4 days, during which time the animals were exposed to sidestream smoke for 20 minutes once a day. Daily urines were collected, and the urinary excretion of 8-iso-PGF(2alpha) was evaluated as an index of oxidative stress-induced in vivo lipid peroxidation. The exposure of rats to passive smoking increased the urinary excretion of 8-iso-PGF(2alpha) by 44+/-4.2% at 48 hours and by 55+/-10% at 96 hours. Treatment with the OMWW extract was able to completely prevent the increase at 48 hours and resulted in lower increments (34+/-18% versus 55+/-10%) of 8-iso-PGF(2alpha) excretion at 96 hours. CONCLUSIONS: A low dose of hydroxytyrosol, administered through OMWW, reduces the consequences of sidestream smoke-induced oxidative stress in rats.

Animals↗
PubMed2000

Diet and prevention of coronary heart disease: the potential role of phytochemicals.

Epidemiological studies, and some clinical trials, demonstrate that a proper diet reduces the rate of occurrence of cardiovascular disorders. Several in vitro studies suggest that some components of plant foods, most of which sharing a phenolic structure, are endowed with interesting 'pharmacological activities'. This article reviews the evidence that links a high dietary intake of phytochemicals from various sources with a reduced incidence of coronary heart disease.

Cacao↗
PubMed2000

Testosterone metabolites in patients reduce the levels of very long chain fatty acids accumulated in X-adrenoleukodystrophic fibroblasts.

Testosterone metabolites (dihydrotestosterone, DHT) and 5 alpha-androstan-3 alpha,17 beta-diol (3 alpha-diol), but not testosterone itself, were shown to reduce the levels of very long chain fatty acids which accumulate in cultured skin fibroblasts from X-adrenoleukodystrophic patients (X-ALD). In addition, in X-ALD fibroblasts, testosterone is less actively converted into DHT vs. controls (skin fibroblasts retrieved from normal subjects) whereas the additional conversion of DHT to the final product 3 alpha-diol is enhanced. This is the first report of altered testosterone metabolism in X-ALD fibroblasts and of the effects of androgens in lowering the abnormal accumulation of very long chain fatty acids in this type of cells.

Adrenoleukodystrophy↗
PubMed2000

The insulin-dependent glucose transporter isoform 4 is expressed in bovine blastocysts.

We have investigated the expression of two glucose transporter isoforms, Glut1 and 4, in 14- and 16-day-old bovine blastocysts (d14, d16) using RT-PCR, competitive RT-PCR and in situ hybridization. The blastocysts were grown in vivo or had been produced in vitro. Glut1 mRNA was detected in all blastocysts studied, Glut4 in all d14 blastocysts, but only in a few d16 blastocysts. Glut4 mRNA was localized in trophoblast and endoderm cells. Glut1 mRNA increased from d14 to d16 while Glut4 transcription was down-regulated in d16 blastocysts. The mRNA amounts varied between 0.8 to 23 pg and 3.9 to 65 fg per 100 ng embryonic RNA for Glut1 and Glut4, respectively, displaying a 100- to 1500-fold lower expression of Glut4 compared with Glut1 during blastocyst elongation. This is the first report on the expression of the insulin-sensitive Glut4 isoform in mammalian preimplantation embryos.

Animals↗
PubMed2000

Endogenous APP derivatives oppositely modulate apoptosis through an autocrine loop.

We have recently shown that, in rat cerebellar granule cells, apoptosis triggered by KCl deprivation is associated with an amyloidogenic shift in the processing of amyloid precursor protein (APP) resulting in an increase of amyloid beta-protein (A beta) secretion. To further investigate this issue we studied the relationship between secretion of APP metabolites (A beta, APPs) and neuronal degeneration. We postulated that the endogenous products of the APP metabolism may modulate neuronal survival by an autocrine loop. Treatment of cerebellar granule cells with various antibodies raised against different epitopes of APPs and A beta oppositely modulates low potassium apoptotic cell death. Antibodies specific for the N-terminal of A beta (4G8, 6E10, R3659) increased neuronal survival by 30% over controls. On the contrary, treatment of cultures undergoing apoptosis with the monoclonal antibody 22C11 directed against the APP N-terminus reduced neuronal survival by 53%, suggesting that endogenous alpha-APPs contribute to neuronal survival. Moreover low KCl culture medium, conditioned by cerebellar granule cells, attenuated the apoptotic process. This anti-apoptotic effect was abolished by removal of APPs from the conditioned medium. Western blotting of APPs removed from the conditioned medium confirmed the presence of alpha-APPs. These data indicate that APP cleavage products oppositely modulate neuronal survival through an autocrine loop and further strengthen an Alzheimer's disease pathogenetic scheme based on altered metabolism of APP.

Amyloid beta-Protein Precursor↗
PubMed2000

In vitro differentiation of human monocytes to macrophages results in depletion of antioxidants and increase in n-3 fatty acids levels.

The lipid composition and alpha-tocopherol content of human monocytes were investigated before and after their differentiation to macrophages. The total lipid and protein content per number of cells increased after the differentiation of monocytes by approximately four-fold; a two-fold increase in docosahexaenoic and docosapentaenoic acids and a two-fold decrease in linoleic acid were also noted. As opposed to an initial monocytic vitamin E content of 4.75 pmol/10(6) cells, macrophagic vitamin E levels were undetectable. Changes in vitamin E and fatty acids contents in macrophages, with respect to monocytes, appear to reflect the lipid composition of fetal calf serum, that is low in vitamin E and has a proportionally higher docosahexaenoic acid content than adult human serum.

Adult↗
PubMed2000

Olive oil phenolics are dose-dependently absorbed in humans.

Olive oil phenolic constituents have been shown, in vitro, to be endowed with potent biological activities including, but not limited to, an antioxidant action. To date, there is no information on the absorption and disposition of such compounds in humans. We report that olive oil phenolics, namely tyrosol and hydroxytyrosol, are dose-dependently absorbed in humans after ingestion and that they are excreted in the urine as glucuronide conjugates. Furthermore, an increase in the dose of phenolics administered increased the proportion of conjugation with glucuronide.

Adult↗