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Biomedical subjects

C Galli

Publications and source records attributed to C Galli.

At least 145 records · Page 8Linked to original sources
PubMed1996

Blood pressure and atherogenic lipoprotein profiles of fish-diet and vegetarian villagers in Tanzania: the Lugalawa study.

BACKGROUND: There is evidence that populations with a high intake of fish, and specifically fish oils, are at reduced risk of cardiovascular disease. To explore the effect of fish intake, we compared two groups of Bantu villagers in Tanzania; one group live on the shores of Lake Nyasa and their diet includes large amounts of freshwater fish; the other group live in the nearby hills and have a vegetarian diet. METHODS: We carried out a cross-sectional study of 622 fish-consuming villagers and 686 vegetarian villagers. 618 (99.4%) and 645 (94.0%), respectively, agreed to take part. Anthropometric and self-reported medical history data were collected by one local physician and a medical assistant, who also measured blood pressure and took blood samples for measurement of plasma lipids. A dietary questionnaire was administered to 25 families (about 15% of the study population) in each village. FINDINGS: After adjustment for age, sex, and alcohol intake the fish-consuming group had lower mean blood pressure than the vegetarian group (123/72 vs 133/76 mm Hg, p < 0.001). The frequencies of definite and borderline hypertension (by WHO criteria) were lower in the fish-consuming than in the vegetarian group (2.8 vs 16.4%; 9.7 vs 22.3%, respectively). Plasma concentrations of total cholesterol (mean 3.53 [SD 1.04] vs 4.10 [1.04] mmol/L), triglycerides (0.92 [0.64] vs 1.31 [0.64] mmol/L), and lipoprotein(a) (201 [213] vs 321 [212] mg/L), were all lower (p < 0.0001) in the fish-consuming group than in the vegetarian group. The proportions of n-3 polyunsaturated fatty acids in plasma lipids were higher (p < 0.0001) in the fish-consuming group than in the vegetarian group (eicosapentaenoic acid 2.3 [1.3] vs 0.7 [0.2]%; docosapentaenoic acid 1.1 [0.4] vs 0.6 [0.3]%; docosahexaenoic acid 5.7 [1.6] vs 1.5 [1.1]%). INTERPRETATION: In these villagers, consumption of freshwater fish (300-600 g daily) was associated with raised plasma concentrations of n-3 polyunsaturated fatty acids, lower blood pressure, and lower plasma lipid concentrations.

Adult↗
PubMed1996

H+-induced membrane insertion of influenza virus hemagglutinin involves the HA2 amino-terminal fusion peptide but not the coiled coil region.

Fusion of influenza virus with target membranes is induced by acid and involves complex changes in the viral envelope protein hemagglutinin (HA). In a first, kinetically distinct step, the HA polypeptide chain 2 (HA2) is inserted into the target membrane bilayer. Using hydrophobic photolabeling with the phospholipid analogue 1-O-hexadecanoyl-2-O-[9-[[[2-[125I]iodo-4(trifluoromethyl-3H-diazirin -3-yl)benzyl]oxy]carbonyl]nonanoyl]-sn-glycero-3-phosphocholine, we identified the segment within HA2 that interacts with the membrane. The sole part of the HA2 ectodomain that was labeled with the membrane-restricted reagent is the NH2-terminal fusion peptide (residues 1-22). No labeling occurred within the long coiled coil region generated during the acid-induced conformational transition (Bullough, P. A., Hughson, F. M., Skehel, J. J., and Wiley, D. C. (1994) Nature 371, 37-43). These data strongly suggest that the coiled coil region of HA2 does not insert into the lipid bilayer. This conclusion is at variance with the recent suggestion (Yu, Y. G., King, D. S., and Shin, Y.-K.(1994) Science 266, 274-276) that the coiled coil of HA may splay apart and insert into the target membrane, providing a mechanism by which the viral and the target membrane may come in close apposition.

Animals↗
PubMed1996

EPR spectroscopic characterization of neuronal NO synthase.

Neuronal NO synthase (nNOS) consists of a reductase domain that binds FAD, FMN, NADPH, and calmodulin, and an oxygenase domain that binds heme, tetrahydrobiopterin, and the substrate L-arginine. One flavin in resting nNOS exits as an air-stable semiquinone radical. During NO synthesis, electron transfer occurs between the flavins and heme iron. We have characterized the nNOS heme iron and flavin semiquinone radical by electron paramagnetic resonance (EPR) spectroscopy. Under anaerobic conditions, the flavin radical spin relaxation was very slow (8 HZ at 22 K) and was enhanced 13-fold by dissolved dioxygen via spin-spin coupling. The flavin radical, probably the semiquinone FMNH., was shown by progressive microwave power saturation and EPR saturation recovery under anaerobic conditions to be spin-spin coupled with the heme iron located in the nNOS oxygenase domain. Analysis of an nNOS preparation that was devoid of heme but contained the flavin radical revealed that spin-spin coupling increased the rate of flavin radical relaxation by a factor of 15. The presence of bound substrate (L-arginine) or the substate analogue Nomega-nitro-L-arginine methyl ester (NAME) had no effect on the flavin spin relaxation kinetics. The observed g values of the nNOS heme were 7.68, and 1.81 and were unchanged by occupation of the substrate binding site by L-arginine or NAME. The substrate also had no effect on the heme zero-field splitting parameter, D=5.2cm-1. Together, the data indicate that the flavin and heme redox centers are positioned near each other in nNOS, consistent with their participating in an interdomain electron transfer. The flavin radical is affected by dissolved oxygen, suggesting that its binding site within the reductase domain partially exposed to solvent, but is unaffected when substrate binds to the oxygenase domain. Substrate binding also appears to take place outside the first coordination shell of the nNOS heme iron.

Animals↗
PubMed1996

Trypanosoma cruzi: the Tc-85 surface glycoprotein shed by trypomastigotes bears a modified glycosylphosphatidylinositol anchor.

Tc-85, an 85-kDa surface glycoprotein specific for the trypomastigote stage of Trypanosoma cruzi, has been implicated in the invasion of host cells by the parasite. Radioactive palmitic acid was incorporated into Tc-85 immunoprecipitated from the culture medium with the H1A10 monoclonal antibody, suggesting that shedding occurs with Tc-85 bearing its GPI anchor. In contrast to the glycoprotein remaining in the parasites, the glycosylphosphatidylinositol moiety in shed Tc-85 is resistant to phosphatidylinositol phospholipase C and becomes susceptible to the enzyme following alkali treatment. An alkylglycerol was identified by thin layer chromatography of an ether extract after the enzymatic reaction. Resistance to cleavage by phospholipase C is due to fatty acid esterification of the inositol residue in shed Tc-85. This is the first example of inositol modification in anchors from a glycoprotein of Trypanosoma cruzi.

Animals↗
PubMed1996

Blood pressure, serum lipids, and fatty acids in populations on a lake-fish diet or on a vegetarian diet in Tanzania.

Major risk factors for coronary heart disease were assessed in two populations of Tanzania, one on a fish diet (FD) living along the coast of Lake Nyasa, and the other, mainly on a vegetarian diet (VD), living in a farming area. Lower blood pressure values were found in the FD subjects (n = 618) vs. VD (n = 618) (systolic blood pressure, SBP, 120 +/- 15 vs. 135 +/- 20, P < 0.01; diastolic blood pressure, DBP, 70 +/- 9 vs. 78 +/- 11, P < 0.01, respectively). In an FD subgroup (n = 61), total cholesterol (TC) (122 vs. 136 mg/dL, P < 0.01); triglycerides (TG) (82 vs. 105 mg/dL, P < 0.01); and lipoprotein (a) [Lp(a)] (19.9 +/- 18.4 vs. 32.3 +/- 22.4, P < 0.001) were lower than in a VD subgroup (n = 55). Serum fatty acids (FA) in the FD subgroup were as follows: eicosapentaenoic acid (EPA) (20:5) 2.48 vs. 0.72%, docosahexaenoic acid (DHA) (22:6) 5.93 vs. 1.49%, vs. the VD, respectively. Arachidonic acid (AA) (20:4n-6) also was higher in the FD vs. the VD group (9.85 vs. 8.30%, P < 0.05), whereas 18:2n-6 was about double (23.97 and 14.85%) in VD vs. FD. The peculiar serum FA pattern in FD reflected the FA of dietary fish. In fact, in four main species of lake fish, DHA was 8-19%, higher than EPA (1.8-4.2%), in contrast with the situation in cold-water fish, and AA was 5.8-8%, higher than in cold-water fish. The data, obtained in populations strictly on natural, unprocessed, low-fat diets, show that a diet based on freshwater fish results in lower BP, serum TC, TG, and Lp(a), and suggests that serum AA is not reduced when the major dietary n-3 is DNA rather than EPA.

Animals↗
PubMed1996

Arachidonic acid synthesis and lipid metabolism in retinoic acid-differentiated neuroblastoma cells.

SK-N-BE cells were differentiated (D) to neurons with retinoic acid. Total n-6 polyunsaturated fatty acids (PUFA), especially arachidonic acid (AA), were increased in D versus ND cells. AA synthesis from linoleic acid (LA) and phospholipid (PL) synthesis from glycerol were initially elevated, whereas both processes were reduced approaching differentiation. At this stage, the incorporation of glycerol in triglycerides was enhanced. Formation of long chain PUFA and synthesis of acceptors (PL) for esterification, during RA-induced SK-N-BE differentiation, appear to be associated.

Arachidonic Acid↗
PubMed1996

Sporadic fundic gland polyps: an immunohistochemical study of their antigenic profile.

Fundic Gland Polyps (FGPs) are small sessile (2-5 mm), usually multiple polyps arising in the gastric, acid-secreting mucosa of disputed histogenesis. They have been described in a sporadic form, prevalently in middle aged females, or associated with familial adenomatosis coli-Gardner's syndrome. We performed an immunohistochemical study on 24 sporadic FGPs, using monoclonal antibodies (MAbs) against differentiation markers, class II MHC antigens (HLA-DR), oncofetal and proliferation antigens, aimed to characterize the antigenic profile of the polyps. A preliminary cytogenetic study on five polyps was also done, using an in situ culture method after collagenase treatment. Cytokeratins 8-18 (CAM 5.2 MAb) and 20 (IT-Ks 20.8 MAb), Epithelial Membrane Antigen (EMA) and Chromogranin A were normally expressed by FGPs. FGPs did not express HLA II DR. FGPs did not react with an anti-CEA MAb (F6), but they were frequently positive (22/24, 91.6%) with B72.3 MAb (reacting with the cancer-associated mucin epitope sialyl-Tn). The PC10 MAb (against PCNA or cyclin) showed enhanced expression in the deep glandular-cystic compartment of FGPs; the PCNA index of FGPs was significantly higher than in normal fundic mucosa. The cytogenetic study on the 5 cases analysed, revealed a normal karyotype. We have demonstrated that FGPs express in the paranuclear zone the sialyl-Tn epitope, a side-chain sugar normally masqued in adult gastric mucins, thus revealing an alteration in mucin synthesis; FGPs' higher proliferation index as compared with normal fundic mucosa supports the hypothesis of their hyperproliferative nature.

Antigens, Neoplasm↗
PubMed1996

Developmentally regulated markers of in vitro-produced preimplantation bovine embryos.

Expression of various developmentally regulated markers was screened throughout the preimplantation stages of in vitro-derived bovine embryos. This was done by investigating the distribution of several nuclear, cytoplasmic and extracellular proteins by means of immunofluorescence microscopy. While lamin B appeared as a constitutive component of nuclei of all preimplantation stages, lamins A/C had a stage-related distribution. The early cleavage stage nuclei contained lamins A/C which generally disappeared in the following stages, with the possible exception of a few positive nuclei in the morula and early blastocyst stage. In the expanded blastocyst stage the nuclei of trophectoderm cells became positive while no positivity was observed in the inner cell mass cells. Starting from day 6, the appearance and/or polarised distribution of various cytoskeletal and cytoskeleton-related components such as F-actin, alpha-catenin and E-cadherin gave an insight into the timing of events related to compaction of bovine embryos. Compaction was correlated with the first differentiation event, i.e. the formation of trophectoderm; this is the first embryonic epithelium, characterised by cytokeratins and desmoplakin. Extracellular fibronectin was first detected in the early blastocyst stage shortly before the morphological differentiation of primitive endoderm, and in the later stages it was localised at the interface between trophectoderm and extraembryonic endoderm. Laminin and collagen IV were expressed by the endoderm cells and contributed to the extracellular matrix underlying the trophectoderm. This study is a first attempt to characterise the cells of in vitro-derived bovine embryos valid for cell line derivation.

Actins↗
PubMed1996

Changes in arachidonic acid levels and formation and in lipid synthesis in the human neuroblastoma SK-N-BE during retinoic acid-induced differentiation.

We observed that retinoic acid, which differentiates the human neuroblastoma SK-N-BE into mature neurons, induced an elevation in levels of polyunsaturated fatty acids, especially arachidonic acid (20:4 n-6). This effect was not induced by phorbol myristate acetate, another differentiating agent. We then explored the effects of retinoic acid on the formation of arachidonic acid and of docosahexaenoic acid from precursors and on the de novo lipid synthesis from acetate at various stages of differentiation, which was assessed by morphological (cell number and neurite outgrowth) and biochemical (protein content and thymidine incorporation) criteria. At 3 days of incubation with retinoic acid, in the n-6 series, total conversion of linoleic acid, especially to 20:3 n-6, was elevated, in association with preferential incorporation of acetate into phospholipids; in contrast, at 8 days, synthesis of 20-carbon polyunsaturated fatty acids declined, in association with enhanced incorporation in triglycerides. In the n-3 series, eicosapentaenoic acid was converted to docosahexaenoic acid in SK-N-BE, but the conversion was not affected by retinoic acid. During the early stage of neuronal differentiation, therefore, enhanced production of 20-carbon polyunsaturated fatty acids from their precursors occurred, and newly formed fatty acids were preferentially incorporated in phospholipids, possibly in association with membrane deposition. When differentiation was completed, arachidonic acid formation and incorporation of acetate in phospholipids and cholesterol declined with enhanced labeling of storage lipids.

Animals↗
PubMed1996

Omega-3 fatty acid supplementation and lipoprotein(a) concentrations in patients with chronic glomerular diseases.

Renal disease patients often exhibit alterations in the lipid profile which may become an important risk of accelerated atherosclerosis and contribute to disease progression. Among such alterations, increased levels of lipoprotein(a) [Lp(a)] are common and may be related, in part, to the degree of proteinuria. Omega-3 polyunsaturated fatty acids (omega-3 FA) have been reported to decrease Lp(a) concentrations in nonrenal subjects. In addition, they have recently been shown to reduce proteinuria in patients with chronic glomerular disease. We therefore tested the hypothesis that omega-3 FA treatment in patients with chronic glomerular disease may reduce Lp(a) concentrations. Eight patients (2 with membranous glomerulonephritis, 6 with focal glomerular sclerosis) were submitted to a total of 13 six-week courses of treatment with omega-3 FA, at a dose of 3 g/day with a triglyceride preparation (n = 4) and of 7.7 g/day with an ethyl-ester preparation (n = 9). Both treatments significantly increased the proportions of omega-3 to omega-6 FA in total serum lipids, documenting compliance to treatment. Both treatments were also effective in decreasing serum thromboxane (from mean 490 +/- (SEM) 70 to 325 +/- 49 ng/ml, p < 0.05, in the high-dose group) and prolonging the bleeding time (from 5.8 +/- 0.4 to 7.7 +/- 0.5 min, p < 0.05, in the high-dose group), thus documenting the biological efficacy of treatment. However, despite a significant reduction in serum triglyceride levels (from 137 +/- 20 to 104 +/- 19 mg/dl in the high-dose group), Lp(a) concentrations did not change (292 +/- 120 U/l before, 315 +/- 130 U/l after the high-dose therapy). Treatment-related changes in proteinuria (from 2.9 +/- 0.5 to 2.1 +/- 0.7 g/24 h) were not related at all to changes in Lp(a) levels. We conclude that omega-3 FA do not decrease Lp(a) concentrations in renal patients with chronic glomerular diseases and that Lp(a) levels are unlikely to be related to the degree of proteinuria within the short-term modifications induced by omega-3 FA.

Adult↗
PubMed1996

[Neuroradiologic study of partial temporal epilepsy].

MR imaging is considered the neuroradiological procedure of choice for the study of intractable partial epileptic patients. The role of CT-scan is limited to the demonstration of calcific components of the lesion and of bony abnormalities of the adjacent skull. In this chapter we describe an MR protocol for the evaluation of temporal lobe epilepsy patient; moreover, here there are described neuroradiological characteristics (MR and CT) of the more frequent temporal lobe lesions.

Astrocytoma↗
PubMed1995

Inhibition of platelet aggregation and eicosanoid production by phenolic components of olive oil.

This study was designed to investigate the in vitro effects of phenolic compounds extracted from olive oil and from olive derived fractions. More specifically, we investigated the effects on platelets of 2-(3,4-di-hydroxyphenyl)-ethanol (DHPE), a phenol component of extra-virgin olive oil with potent antioxidant properties. The following variables were studied: aggregation of platelet rich plasma (PRP) induced by ADP or collagen, and thromboxane B2 production by collagen or thrombin-stimulated PRP. In addition, thromboxane B2 and 12-hydroxyeicosatetraenoic acid (12-HETE) produced during blood clotting were measured in serum. Preincubation of PRP with DHPE for at least 10 min resulted in maximal inhibition of the various measured variables. The IC50s (concentration resulting in 50% inhibition) of DHPE for ADP or collagen-induced PRP aggregations were 23 and 67 microM, respectively. At 400 microM DHPE, a concentration which completely inhibited collagen-induced PRP aggregation, TxB2 production by collagen- or thrombin-stimulated PRP was inhibited by over 80 percent. At the same DHPE concentration, the accumulation of TxB2 and 12-HETE in serum was reduced by over 90 and 50 percent, respectively. We also tested the effects of PRP aggregation of oleuropein, another typical olive oil phenol, and of selected flavnoids (luteolin, apigenin, quercetin) and found them to be much less active. On the other hand a partially characterized phenol-enriched extract obtained from aqueous waste from olive oil showed rather potent activities. Our results are the first evidence that components of the phenolic fraction of olive oil can inhibit platelet function and eicosanoid formation in vitro, and that other, partially characterized, olive derivatives share these biological activities.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗
PubMed1995

'Waste waters' from olive oil production are rich in natural antioxidants.

Milling of olive paste during olive oil production is accompanied by continuous washing with water, i.e. malaxation. The resulting 'waste-water' is currently discarded. Since olives and olive oil are rich in natural antioxidants, we hypothesized that some of these might be extracted from the olive paste during malaxation. Interest in natural antioxidants is increasing because of the growing body of evidence indicating the involvement of oxygen-derived free radicals in several pathological processes, such as cancer and atherosclerosis. A waste-water extract was characterized by HPLC and tested in a model of lipid peroxidation, copper sulphate-induced oxidation of low density lipoproteins. The results demonstrate that waste-water extracts have powerful antioxidant activity and might therefore represent a cheap, as yet unused, source of natural antioxidants.

Antioxidants↗