Biomedical subjects
Publications and source records attributed to C Galli.
A 50-year-old female underwent surgical removal of a mammary phyllodes tumor, whose peculiar histologic feature was the coexistence of areas of liposarcoma and leiomyosarcoma. The morphologic differential diagnosis is briefly discussed.
Interleukin-1 (IL-1) can initiate the synthesis of prostaglandins which in turn act as endogenous modulators of IL-1 production. The human monocyte/macrophage synthesizes various eicosanoids through the activation of the cellular phospholipase system. Cell stimulation results in the activation of phospholipase A2 (PLA2) whose major substrate is phosphatidylcholine (PC) and the release of the eicosanoid precursor arachidonic acid (AA) from PC. Another pathway is the stimulation of a phospholipase C (PLC) mainly active on phosphoinositides and the resulting formation of inositol phosphates (IPs) and diacylglycerol (DAG). Phospholipids other than phosphoinositides can also be hydrolysed by PLC to give rise to DAG. Studies have shown that IL-1 does not activate the IP pathway, but it primarily stimulates a PLC linked to phosphatidylethanolamine in cultured rat mesangial cells, and a PLC linked to PC in Jurkart cells. We have stimulated human monocytes with IL-1 and calcium ionophore A23187 and we have observed their effect on the phospholipase system. The results indicate that IL-1 does not activate the formation of IPs in cells labeled with [3H]myo-inositol. In contrast, in cells labeled with [3H]AA, IL-1 causes the formation of DAG associated with the hydrolysis of PC. Moreover, after stimulation with IL-1 there is no accumulation of free AA which would indicate that there has been no activation of PLA2, which occurs instead with A23187 stimulation. These data suggest that, in monocytes, IL-1 does not directly stimulate a PLA2 or a PLC active on phosphatidylinositol; instead it primarily stimulates a PLC active on PC.
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The aim of our study was to confirm by Recombinant Immunoblot Assay (RIBA) and by neutralization assay the repeat positive reactions found by two commercially available EIAs (Ortho and Abbott) when testing samples from volunteer blood donors, patients with chronic liver disease and with hepatocellular carcinoma. Our data show a high confirmatory rate among patients with chronic viral NANBH and HCC, while among donors and patients with CLD other than NANBH the percentage of presumptive EIA positive reactions confirmed by RIBA and/or neutralization assay is much lower. In our experience, the neutralization assay appears to be somewhat more sensitive than RIBA, especially when samples show low EIA optical densities.
The seroprevalence of HTLV-I/II was evaluated in 1247 Italian individuals at high risk for HIV infection. The population studied consisted of 985 intravenous drug users (IVDUs), 474 of whom on methadone maintenance and 511 in a therapeutic community, 110 HIV-infected patients in various stages of HIV-related disease and 152 hemophiliacs. Sera were screened for antibody to HTLV-I/II by enzyme immunoassay (EIA) and confirmed by Western blot and radioimmunoprecipitation assay. Confirmed positive samples were further differentiated by EIA using HTLV-I and HTLV-II specific peptides. The overall prevalence of anti-HTLV-I/II was 4.0% in IVDUs, with the highest prevalence (8.2%) among HIV-infected symptomatic patients. None of the hemophiliacs was anti-HTLV-I/II positive, even though 63.1% tested positive for HIV antibodies. The trend of seroprevalence in drug users and the evaluation of possible risk factors demonstrated that HTLV-I/II infection has been present in Italy before the onset of HIV epidemic. The overall seroprevalence showed no significant changes during the 10 year period covered by this survey but correlated with HIV seropositivity, age and duration of drug use. Peptide testing showed that HTLV infection was mainly due to HTLV-II.
The plasma kinetics of a preparation of dilinoleoyl phosphatidylcholine (DLPC) specifically labeled with 3H in the choline moiety and with 14C in the 2-fatty acid (FA) were evaluated in six healthy volunteers after oral administration. Retention of both isotopes in plasma exceeded expectations, with a half-life in the elimination phase of 172.2 h for 3H and 69.7 h for 14C. Up to 60 d after administration, there were still significant levels of radioactivity present in plasma. The relative stability of the [14C]FA label was demonstrated by the retention for more than 12 h of an isotope ratio close to that of the compound administered. The 14C label of DLPC remained in position-2, as assessed by cleavage of plasma phospholipids with phospholipase A2. The [3H]choline label showed an early incorporation into high density lipoproteins and subsequently into low density lipoproteins (LDL); conversely, the 14C radioactivity was rapidly incorporated into triacylglycerols that were mainly associated with very low density lipoproteins. Radioactivity measurements revealed that both isotopes remained the longest time in LDL. In red blood cell (RBC) lipids, [3H]choline radioactivity accumulated over time, with a plateau after 48 h, whereas FA radioactivity accumulated more rapidly and was followed by a progressive decay. Analysis of the isotope ratio in these cells suggested an early incorporation of lyso products followed by rapid transfer of FA from plasma. The RBC maintained considerable radioactivity for a prolonged time, thus acting as a possible reservoir for the DLPC administered.(ABSTRACT TRUNCATED AT 250 WORDS)
Four diets containing 20% of energy (en%) as fat and with linoleic acid contents of 1.9, 3.1, 7.7 and 10.1 en%, respectively, were fed to one-month-old male rats for three months. The fatty acid profiles and the levels of the major n-6 and n-3 fatty acids in the lipids of plasma, liver, heart and kidney were measured. We found that with increasing concentrations of 18:2n-6 in the diet, linoleic acid rose in plasma and in all organs, but long-chain n-6 and n-3 fatty acids responded differently. In liver, arachidonic acid increased and n-3 fatty acids were not significantly affected; in heart, both arachidonic and docosahexaenoic acids were progressively reduced; and in kidney, there was no change of n-6 and n-3. The results indicate that incremental changes in dietary linoleate affect the levels of polyunsaturated fatty acids in liver and extrahepatic organs differently.
A two step enzymatic procedure for the isolation of ovarian follicles and oocytes at early stages of development from the ovaries of newborn piglets was devised. The isolated oocytes were then separated from the overwhelming majority of the ovarian somatic cells using a centrifugal elutriation system. Twenty to thirty thousand oocytes were routinely collected after elutriation of the cell suspension derived from a pair of ovaries. In the enriched fraction the ratio of oocyte:somatic cells was between 1:1 and 1:3. The validation of the method as an efficient procedure for the isolation of a large, viable, and highly enriched population of oocytes at early stages of development was provided by uptake studies carried out after each step of the isolation and separation technique and by a comparative analysis of the pattern of structural proteins of the enriched fraction and of fully grown porcine oocytes. The results confirmed that the isolated cells were actually oocytes at early stages of development and that they were viable throughout the entire procedure.
To evaluate which dietary fat may provide the best response in terms of plasma lipids and lipoproteins and also of platelet aggregability and superoxide formation by white blood cells, 12 type II patients were randomly allocated to three different diets, which provided polyunsaturated fatty acids (corn oil), monounsaturated fatty acids (olive oil), and a supplementation of ethyl esters of n-3 fatty acids to a prudent diet. Olive oil and, more significantly, n-3 ethyl esters lowered total cholesterol best (-2.2% and -5.8%, respectively); the latter diet, as expected, also significantly lowered triglyceridemia (-21.4%). The corn-oil diet exerted a small, statistically significant reduction of high-density-lipoprotein cholesterol (HDL) (-4.3%), and it also lowered plasma total apo B concentrations (-3.8%). n-3 ethyl esters significantly raised both total (+3.1%) and particularly HDL2 cholesterol (+24%). Platelet reactivity was insignificantly reduced by the three regimens, but all three significantly reduced thrombin-stimulated formation of thromboxane B2. Finally, only the n-3 fatty acid supplementation significantly reduced O2- generation by adherent monocytes. Dietary unsaturated fatty acids are generally effective on the plasma lipid and lipoproteins in type II patients, but significant differences may be found between the three tested regimens.
Levels of plasma lipids and the fatty acid composition of major plasma lipid classes have been determined in chronically uremic patients before and after treatments with hemofiltration, high efficiency paired filtration dialysis, or acetate-free biofiltration. The major findings are a decrease of triglycerides and an increase of total free fatty acids (FFAs) at the end of the dialytic session--already reported in the literature--that do not appear to be strictly dependent on heparin administration. The changes in the plasma concentrations of selected saturated and polyunsaturated fatty acids, which may contribute to alteration of functional parameters in the cardiovascular system in dialyzed patients, are different in the various types of techniques.
The stability of exogenous DNA microinjected into the cytoplasm at different stages of the meiotic cycle and after pronuclear formation was examined in ungulate species. Metabolism of the injected 1201 base pair (bp) DNA was examined by Southern blotting. Similar levels of metabolism of the injected DNA were detected in pig, sheep and bovine oocytes before germinal vesicle breakdown, in which about 30-40% of detected DNA was ligated into higher-molecular-weight forms. Porcine metaphase oocytes and pronuclear zygotes showed a reduced ability to ligate the exogenous DNA. In contrast, sheep and bovine metaphase oocytes and zygotes showed increased levels of ligation and, at the pronuclear stage, generated significant amounts of extremely large (greater than 15 kbp) ligation products. These results are discussed in the context of maternal precursors and metabolic activities in the egg.
The aim of our study has been to investigate the metabolism of endogenous arachidonic acid or that of radiolabeled arachidonate in astroglial cells, stimulated with platelet activating factor (PAF) and with the calcium-ionphore A23187. Primary cultures of astroglial cells were obtained from brain cortex of one-day-old rats and were characterized by immunofluorescent staining vs glial fibrillary acidic protein. In labeled cells, diacylglycerol was formed after stimulation with platelet activating factor, whereas mainly the release of labeled arachidonic acid from phospholipids was observed after stimulation with calcium-ionophore. Both PAF and the calcium-ionophore A23187 actively stimulated the formation of the cycloxygenase products PGD2, TXB2 and 6-keto-PGF1 alpha, measured by radio- or enzyme-immunoassay. Differences were observed, instead, in the formation of the lipoxygenase metabolites, the hydroxyeicosateraenoic acids, which were measured by high pressure liquid chromatography (HPLC) with on line radiodetection for the labeled products, and Leukotriene C4, measured by radioimmunoassay. The formation of hydroxyacids by stimulated cells was confirmed by gas chromatography-mass spectrometry (GC-MS). In labeled cells, both agonists induced the formation of 12- and 15-hydroxyeicosatetraenoic acids, whereas stimulation of unlabeled cells with calcium ionophore resulted in formation of 12-hydroxyeicosatetraenoic acid and Leukotriene C4. Our results suggest that in astroglial cells, PAF, a compound which is produced in several tissues including brain, mobilizes a selected arachidonic acid pool, possibly associated with diacylglycerol production, from phospholipids, thus activating the conversion of the released fatty acid via the cyclo and the 12-lipoxygenase pathways.
We studied the aggregation of collagen and ADP-stimulated platelet-rich plasma (PRP) and the formation of thromboxane B2 (TxB2) by collagen-stimulated PRP in spontaneously hypertensive rats (SHR) and in Wistar-Kyoto control rats (WKY). In addition, we evaluated the inhibition of the aggregation of PRP following homologous or heterologous perfusions through isolated aortas, the release of 6-keto-prostaglandin (PG)F1 alpha from these arteries perfused with PRP, and the sensitivity of PRP to the antiaggregatory activity of the stable PGI2 analogue, iloprost, in both SHR and WKY. The lower activities (aggregation induced by ADP and collagen, collagen-stimulated TxB2 production) of SHR platelets, were not accompanied by morphological differences from WKY platelets. These changes were associated with a greater release of arterial 6-keto-PGF1 alpha, with greater platelet antiaggregatory activity of the arterial wall and with higher sensitivity of platelets to iloprost. The lower reactivity of platelets to aggregating agents, and the greater sensitivity to prostacyclin, associated with a greater production of arterial prostacyclin were the major changes observed in SHR animals. These alterations in the SHR vs. normotensive WKY may lead to an enhanced risk of hemorrhage in the hypertensive state.
The effects of omega-3 fatty acid supplementation on high-density lipoprotein (HDL) subfraction distribution and composition were evaluated in five healthy volunteers taking 2.8 g/d of eicosapentaenoic acid (EPA) and 1.7 g/d of docosahexaenoic acid (DHA) for 6 weeks. This supplementation resulted in marked changes of the plasma fatty acid composition. Plasma total cholesterol (TC), HDL-cholesterol (HDL-C), and triglyceride (TG) levels did not change. HDL2-C increased by 74%, with a concomitant 19% decrease of HDL3-C; the HDL2 to HDL3 mass ratio increased from 0.30 +/- 0.19 to 0.47 +/- 0.28. The increase of HDL2 was confirmed by nondenaturing polyacrylamide gradient gel electrophoretic separation of HDL subclasses, otherwise showing no change in HDL particle size. After omega-3 supplementation, both HDL2 and HDL3 became cholesteryl ester (CE)- and TG-enriched and free cholesterol (FC)- and phospholipid (PL)-depleted. The reported findings provide a useful adjunct to the antithrombotic potential of omega-3 fatty acids.
The fatty acid composition of plasma and erythrocyte lipids was analyzed in 15 children with phenylketonuria (aged 3 to 12 years) during dietary treatment aimed to maintain plasma phenylalanine levels at less than 8 mg/dl (485 mumol/L), and compared with those of 12 matched control subjects. The diet of children with phenylketonuria provided less protein, with a very low proportion of animal proteins, less fat, but a higher proportion of linoleic acid as a percentage of calories, and a higher carbohydrate content versus that in the diet of control subjects. The children with phenylketonuria had higher plasma levels of oleic acid but lower levels of arachidonic (n-6) and n-3 fatty acids. Linoleic and eicosatrienoic (n-9) acid levels were the same in both groups. These changes in patients with phenylketonuria resemble those observed in vegetarians and may be due to the absence of preformed arachidonic acid and long-chain n-3 fatty acids in the phenylketonuric diet.
New protein synthesis is essential in sheep oocytes for the progression of the meiotic cycle to metaphase. Inhibition of transcription by alpha-amanitin, a specific inhibitor of RNA polymerase II, arrests meiosis in the G2 phase in cumulus enclosed oocytes but denuded oocytes progress to M-phase. Denuded oocytes injected with alpha-amanitin also undergo maturation. Cumulus-enclosed and denuded oocytes were also cultured on transcriptionally inactive follicle shells to examine the influence of transcription in the granulosa cell compartment on the progression of meiosis. No effect of alpha-amanitin was detected on the maturation rate of both cumulus enclosed and denuded oocytes. We conclude that transcription is required in the cumulus cells to allow translation of stored messages within the oocytes coding for cell-cycle proteins.
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