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D Caruso

Publications and source records attributed to D Caruso.

49 records · Page 3Linked to original sources

Platelet formation of 12-hydroxyeicosatetraenoic acid and thromboxane B2 is increased in type IIA hypercholesterolemic subjects.

The formation of the major metabolic products of endogenous arachidonic acid (AA) via cyclooxygenase and lipoxygenase pathways in platelets from normal and type IIA hypercholesterolemic subjects was evaluated. 12-Hydroxyeicosatetraenoic acid (12-HETE) and thromboxane B2(TXB2) were determined by selected ion monitoring (SIM) after extraction and purification of collagen stimulated platelet-rich plasma (PRP). The levels of both arachidonic acid metabolites in the non-stimulated PRP of control and type IIA subjects were below the detection limit of the method, rising significantly after collagen stimulation. Both 12-HETE and TXB2 levels in collagen-stimulated PRP samples from the patients were significantly higher than levels in controls (P less than 0.001). In view of the key role of 12-HETE in mediating smooth muscle cell migration and proliferation and in stimulating macrophage activity, these data may provide information for the understanding of the elevated incidence of thrombosis and atheromatous lesion in patients with type IIA hypercholesterolemia.

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

Influence of diamide on aggregation, cytoskeletal proteins, and arachidonic acid metabolism in human platelets.

Simultaneous addition of diamide (azodicarboxylic acid-bis-dimethylamide, DIA), a SH-oxidizing agent, and collagen causes a deaggregation of otherwise irreversibly aggregating platelets. Thromboxane B2 (TXB2) and 12-HE-TE formation is inhibited depending on the concentration ratio between collagen and DIA. Thus, at 0.25 mM DIA and 20 micrograms/ml collagen neither TXB2 nor 12-HETE were measurable, but a full scale reversible aggregation is induced. Deaggregation is further attained by adding DIA to collagen-induced aggregates at a time, when maximum amplitude has been achieved. Investigation of arachidonic acid (AA) metabolites under these conditions revealed no influence of DIA on AA metabolism. Therefore, AA metabolization seems to play a minor role in collagen-induced aggregation and DIA-induced deaggregation. Polymerization of certain cytoskeletal proteins of the platelets, after addition of DIA, parallels DIA-induced deaggregation. DIA inhibits endogenous AA release, probably by interaction with platelet plasma membrane. DIA seems to inhibit the release of the alpha-granula protein thrombospondin.

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

Quantitative analysis of alpha, beta-thujone, pulegone, safrole, coumarin and beta-asarone in alcoholic beverages by selected-ion monitoring.

Interest in the quantitative analysis of flavouring agents in alcoholic beverages arises from the possible toxicological consequences deriving from their use. The method reported here, based on gas chromatography with selected-ion monitoring mass spectrometry (SIM), allows the simultaneous measurement of alpha, beta-thujone, pulegone, safrole, coumarin and beta-asarone at the ppb level in alcoholic beverages.

Alcoholic Beverages↗

Eradication of Salmonella and Arizona species from turtle hatchlings produced from eggs treated on commercial turtle farms.

On commercial turtle farms more than 40% of the hatchlings excrete detectable levels of Salmonella and Arizona spp. when hatched from nonsanitized eggs incubated in sawdust or dirt-filled chambers. Over a 3-year period on 10 farms, more than 10(6) turtle eggs were treated in an attempt to hatch Salmonella-free turtles. Eggs were sanitized in disinfectant, treated by temperature- or pressure-differential dip methods in solutions containing 500 micrograms or more of gentamicin sulfate per ml, and hatched in sanitized plastic chambers free of bedding material. The Salmonella and Arizona spp. infection levels for turtles produced from treated eggs were 0 and 1.12% for years 1 and 2, respectively, whereas infection levels for hatchlings produced from nontreated eggs during these periods were 47 and 44%, respectively. During year 3, dip solutions were filtered daily, treated at 100 degrees C for 15 min on a weekly basis to free the solution of microbial contaminants and egg protein, charged with gentamicin after 10,000 to 20,000 eggs had been treated to maintain antimicrobial activity at 500 micrograms/ml or more, and maintained at pH 6.0 to preserve optimal antimicrobial activity. The implementation of these measures in year 3 resulted in an infection level of 0.15% when the tissues of 3 of 1,959 hatchlings tested were positive for Salmonella and Arizona spp., whereas the tissues of 66 (49.0%) of 135 hatchlings produced from nontreated eggs were positive.

Animals↗

Dependence of arachidonic acid (AA) metabolization in human blood platelets on reduced coenzymes.

In human platelets the metabolization of AA is linked to a consumption of the reduced coenzymes NADPH and GSH which can be attributed to about 70% to the cyclooxygenase (CO) and to about 30% to the lipoxygenase (LO) pathway. In GSH depleted platelets the conversion of AA in the LO pathway to 12-HETE is strongly impaired, whereas the formation of the stable CO products from exogenous AA is not decreased, but accelerated. When platelets are deprived from GSH by oxidation to GSSG, the release of endogenous AA from phospholipids in activated platelets is inhibited.

Arachidonic Acid↗

Preferential utilization of endogenous arachidonate by cyclo-oxygenase in incubations of human platelets.

Thromboxane B2 (TXB2) and 12-hydroxy-5,8,10,14-eicosatetraenoic acid (12-HETE) formed from the endogenous and exogenous arachidonate during human platelet incubation, was evaluated by selected ion monitoring (SIM). TXB2 formed from endogenous substrate accounted for about one third of the total, whereas the great part of 12-HETE derived from exogenous arachidonate. These data indicate that under the tested conditions the pool of arachidonate that acts as substrate for cyclo-oxygenase is different from the pool that acts as substrate for lipoxygenase and that the arachidonate released from phospholipids is preferentially utilized by cyclo-oxygenase.

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

Time course and concentration dependence of the incorporation of deuterated/tritiated arachidonic acid and derived fatty acids in THP-1 cell lipids.

We have supplemented THP-1 cells, a human monocytic leukemia cell line, with arachidonic acid (AA), containing [3H8] AA, 1-25 microM, for up to 24 hours, and explored the time and concentration dependent patterns of incorporation in cell lipid classes and subclasses. Twenty-five microM AA consisted of deuterated AA ([2H8] AA), containing also [3H8] AA. Phospholipids (PL) were separated by HPLC with UV and radiodetection, and the fatty acids (FA) methyl esters were analyzed by GC. [2H8] AA pentafluorobenzyl-esters from individual lipid classes were obtained and analyzed by GC-MS. Incorporation of AA in cell lipids increased linearly with increasing concentrations, whereas 22:4 and 22:5 accumulated only at 25 microM AA. Up to 10 microM AA, more than 95% of the FA was incorporated in PL, whereas at 25 microM AA a significant proportion of the exogenous FA was incorporated in triglycerides (TG) and in diacyl phosphatidylcholine (PC). The time-course of AA incorporation showed that the peak was at 3 hours, with minimal incorporation in TG, in the presence of 5 microM, whereas the peak occurred at 6 hours, with about 50 percent incorporation in TG, with 25 microM. The data indicate that the range of AA concentrations and the time course of the incorporation of this FA in cell structural lipids are critical.

Arachidonic Acid↗