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Biomedical subjects

G Pagliuca

Publications and source records attributed to G Pagliuca.

10 recordsLinked to original sources
PubMed2006

Effect of exposure to benzo[a]pyrene on SODs, CYP1A1/1A2- and CYP2E1 immunopositive proteins in the blood clam Scapharca inaequivalvis.

The effects of water-borne exposure to benzo[a]pyrene (36 h; celite-bound 0.44 mg L(-1) B[a]P) on cytochrome P450 (CYP) and superoxide dismutases (SODs) were examined in digestive gland of the blood clam, Scapharca inaequivalvis. B[a]P accumulation and elimination were rapid, with maximum whole-body concentrations of 1.78 ng g(-1) wet wt after 12 h of treatment, followed by a progressive decline to 0.89 ng g(-1) at 36 h. The presence of B[a]P resulted in an increase in total CYP of digestive gland microsomes from 54+/-14 to 108+/-21 pmol/mg protein (mean+/-SD; p<0.05, 24 h). Increases were also seen in microsomal CYP1A1/1A2-immunopositive protein (50.5 kDa app. mol. wt; p<0.05), but not CYP2E1-immunopositive protein (49 kDa app. mol. wt.), indicating a specific response of the former isoform. Exposure to B[a]P produced a steady increase in Mn-SOD digestive gland activity (p<0.01; p<0.05) but no significant change in Cu/Zn-SOD activity. The respective proteins, measured by western blotting, were not significant induced after B[a]P exposure. Cu/Zn-SOD and Mn-SOD activities were correlated with total CYP levels (r=0.96 and 0.63, respectively), indicating a role for CYP in reactive oxygen species (ROS) production during exposure. Both 'NADPH-independent' and NADPH-dependent metabolism of B[a]P by digestive gland microsomes was seen, producing mainly 1,6-, 3,6- and 6,12-diones, with some phenols and 7,8-dihydrodiol; putative protein adducts were also formed. Redox cycling of the diones may also have contributed to ROS production, leading to the increased SOD activities.

Animals↗
PubMed2005

Activated carbon does not prevent the toxicity of culture material containing fumonisin B1 when fed to weanling piglets.

Fumonisins are mycotoxins found primarily in corn and corn products that are produced by Fusarium verticillioides, F. proliferatum, and several other Fusarium species. The toxicity of fumonisin B1 (FB) from culture material with and without activated carbon was evaluated using weanling piglets. Fifty-six weanling pigs were assigned to one of four treatments diets based on BW. The treatment diets were 1) control = corn-soybean basal diet with < 2 ppm FB; 2) AC = control + activated carbon at 1% of the diet, as fed; 3) FB = control + culture material (formulated to contain 30 ppm FB, as-fed basis); and 4) AC + FB = control + activated carbon at 1% of the diet as fed + culture material (formulated to contain 30 ppm FB). A total of four replicates of four pigs per pen for the control and AC treatments and three piglets per pen for the FB and AC + FB treatments were used. Feed and water were offered ad libitum for the duration of the 42-d experiment. Compared with pigs fed the control or AC diets, pigs receiving the two FB-contaminated diets (FB or AC + FB) had lower G:F (P < 0.01), higher serum enzyme activities of gamma-glutamyltransferase and glutamic oxaloacetic transaminase (P < 0.05), and higher concentrations of cholesterol, free sphinganine, sphingosine-1-phosphate, and sphinganine 1-phosphate (P < 0.05). Although animals consuming FB diets showed no signs of respiratory distress, all pigs consuming either the FB or the AC + FB diets had marked pulmonary edema. Lesions were observed in the lungs, heart, and liver of pigs fed the FB or AC + FB diets, and treatment-associated changes also were seen in the pancreas, intestines, spleen, and lymph nodes. No lesions were observed in the brain. In liver, lung, heart, pancreas, spleen, intestines, and lymph nodes, the histopathological effects observed were more severe in the AC + FB group, suggesting that the AC treatment worsened the toxic effects of FB. Additionally, immunological measurements of macrophage function (CD14) were affected (P < 0.05) by the consumption of the FB diets. The consumption of FB diets containing 30 ppm fumonisin B1 from cultured material significantly affected performance, biochemical measurements, and organ pathology in weanling pigs. The addition of activated carbon at the rate of 1% to the diet was not effective in protecting against the detrimental effects of fumonisin consumption.

Adsorption↗
PubMed2005

Extended parotidectomy.

Malignant tumours of the parotid gland represent a group of relatively rare lesions. The medical records of 363 patients with parotid swelling treated between 1974 and 2003 at the "G. Ferreri" Department of Otorhinolaryngology, "La Sapienza" University in Rome were retrospectively analysed. Clinical presentation, pre-operative investigations, surgical procedure, histopathology report, post-operative complications, and the oncological results of 19 patients who underwent extended radical parotidectomy for malignant neoplasm of the parotid gland are discussed. Extended radical parotidectomy, reserved for neoplasms in an advanced stage, involves the removal of the entire parotid gland, with sacrifice of the facial nerve and the resection en bloc of the adjacent structures affected by neoplastic infiltration, such as the temporal bone, the mandibular bone, the skin, blood vessels and nerves. In addition to this surgical treatment, a cycle of adjuvant radiotherapy is also necessary. The overall rate of survival at 10 years depends mainly on the histological characteristics of the tumour, and, in this series, is reported to be approximately 58%. These data indicate that total extended radical parotidectomy combined with post-operative radiotherapy, represents the best therapeutic approach with regard both to quality of life and life expectancy, in patients with an advanced stage of malignant neoplasm of the parotid gland.

Adult↗
PubMed1996

Synthesis of highly pure dolichyl and cholesteryl esters.

Highly pure dolichyl and/or cholesteryl esters can be synthesised at room temperature by reacting a defined pure dolichol and/or pure cholesterol with an acyl chloride in the presence of pyridine. During the reaction some acyl anhydride originates as a secondary product. It can be hydrolysed by methanolic KOH and removed by a rapid percolation of the reaction mixture through a small alumina column. A final purification of the raw product obtained by silicic-acid/celite column chromatography makes it possible to obtain highly pure esters with a satisfactory yield.

Cholesterol Esters↗
PubMed1995

Simultaneous reversed-phase high-performance liquid chromatographic separation of non-polar isoprenoid lipids and their determination.

A procedure for the rapid identification and determination of non-polar isoprenoid lipids from animal tissues was developed. The complete determination can be carried out by reversed-phase HPLC of just two samples. The first, extracted from unaltered tissues and suitably processed by column chromatography, provides information about free cholesterol, cholesteryl esters, coenzymes Q, free dolichols and dolichyl esters. The second, obtained from saponified tissues, can be used to detect both total cholesterol and total dolichols. Specific calibration graphs were constructed for the determination of the different constituents.

Animals↗
PubMed1989

Systematic isolation and identification of membrane lipid oxidation products.

This report discusses the analytical procedure by which it is possible to isolate and identify the oxidation products of cellular and subcellular membrane lipids. The key point of this procedure is the method used for the transmethylation of the lipid material isolated from the tissues. In effect, both the conversion of the glycerides into methyl esters and the reduction of the hydroperoxyl groups into the corresponding hydroxyl groups is performed in one step, without breaking any oxirane rings that may be present. The methyl esters containing functional groups introduced by oxidative processes are separated from the non-modified ones by preparative TLC and are identified by GLC and GC-MS.

Chromatography, Thin Layer↗
PubMed1988

Lipid peroxidation in cancer cells: chemical and physical studies.

Our studies on the biochemical composition and the structural organization of smooth and rough endoplasmic reticulum isolated from Morris hepatomas 9618A and 3924A confirm the results obtained employing the total microsomal fraction. We have definitely established the following facts: (1) Tumor subcellular organelles exhibit the very low degree of peroxidizability that has been shown to be related to the growth rate of the tumor. (2) Associated with such a low susceptibility to peroxidation are (a) changed lipid composition of cellular membranes, whose content in polyunsaturated fatty acid is markedly decreased, and (b) changed static and dynamic properties of the membrane. Previously it was also found that cellular oxy-radical scavenging enzymes are markedly reduced. From these data, it is possible to infer that tumor membranes are altered structurally and functionally in part as the result of an oxy-radical-induced damage that occurs in vivo under conditions of oxygen toxicity. This seems to be supported by recent findings that the spontaneous increase in growth rate of the originally very slow-growing Morris hepatoma 9618A results also in the loss of cytochrome P-450 (an important intramembraneous propagator of lipid peroxidation) as well as of C20:4 and C22:6. Studies performed by GLC and GC-MS on the fatty acid residues of phospholipids of rat liver microsomes show the presence of C20:3-OH and C18:1-OH, but no hydroxyl derivatives of low molecular weight aldehydes. The hydroxyl derivatives of arachidonic acid and linoleic acid are present in much smaller amounts in the microsomes isolated from H9618A and H3924A.

Animals↗
PubMed1987

Proposal of an analytical method for the study of the oxidation products of membrane lipids.

A method of lipid sample preparation for GLC and GC-MS analysis is presented which would seem particularly suitable for studying the chemical composition of the oxidation products of membrane lipids. The method requires small amounts of lipid, is quite rapid and avoids the formation of oxidation artifacts during the different analytical steps. Due to the small quantities of lipid material used it is possible that the method is not rigorously quantitative. Transmethylation of lipids is carried out with methanolic NaBH4 in the presence of NaOH. The reaction is complete in 20 min both on neutral and on polar lipids. In the course of the transmethylation the hydroperoxidic groups are reduced to the corresponding hydroxy groups and can be located through the GC-MS spectra of the corresponding TMS derivatives. The epoxidic rings that may be present are not hydrolyzed. They are located by opening the ring with BF3/MeOH and by GC-MS analysis of the corresponding methoxy-hydroxy derivatives.

Chromatography, Gas↗