Effects of bleomycin and antioxidants on the fatty acid profile of testicular cancer cell membranes.

Bleomycin is used in chemotherapy regimens for the treatment of patients having testicular germ-cell tumor (TGCT). There is no study in the literature investigating the effects of bleomycin on membrane lipid profile in testicular cancer cells. We investigated membrane fatty acid (FA) profiles isolated, derivatized and analyzed by gas chromatography of NTera-2 testicular cancer cells incubated with bleomycin (Bleo) for 24 h in the absence and presence of N-Acetyl-L-Cysteine (NAC) and curcumin (Cur) as commonly used antioxidant adjuvants. At the same time the MAPK pathway and EGFR levels were followed up. Bleomycin treatment increased significantly saturated fatty acids (SFA) of phospholipids at the expense of monounsaturated (MUFA) and polyunsaturated fatty acids (PUFA). Bleomycin also led to a significant increase in the trans lipid isomers of oleic and arachidonic acids due to its free radical producing effect. Incubation with bleomycin increased the p38 MAPK and JNK levels and downregulated EGFR pathway. Coincubation of bleomycin with NAC reversed effects caused by bleomycin. Our results highlight the important role of membrane fatty acid remodeling occurring during the use of bleomycin and its concurrent use with antioxidants which can adjuvate the cytotoxic effects of the chemotherapeutic agents.

Preference and avoidance pH of brook trout Salvelinus fontinalis and brown trout Salmo trutta exposed to different holding pH.

The goal of this study was to determine if short-term exposure of brook trout Salvelinus fontinalis and brown trout Salmo trutta to a lower pH than found in their source stream results in a shift in preference or avoidance pH. The lack of a shift in preference or avoidance pH of adult S. fontinalis and S. trutta suggests that these species can be held at a pH different from the source waterbody for a short period of time without altering preference or avoidance pH behaviour.

pH preference and avoidance responses of adult brook trout Salvelinus fontinalis and brown trout Salmo trutta.

The pH preferred and avoided by wild, adult brook trout Salvelinus fontinalis and brown trout Salmo trutta was examined in a series a laboratory tests using gradual and steep-gradient flow-through aquaria. The results were compared with those published for the observed segregation patterns of juvenile S. fontinalis and S. trutta in Pennsylvania streams. The adult S. trutta tested showed a preference for pH 4·0 while adult S. fontinalis did not prefer any pH within the range tested. Salmo trutta are not found in Pennsylvania streams with a base-flow pH < 5·8 which suggests that S. trutta prefer pH well above 4·0. Adult S. trutta displayed a lack of avoidance at pH below 5·0, as also reported earlier for juveniles. The avoidance pH of wild, adult S. fontinalis (between pH 5·5 and 6·0) and S. trutta (between pH 6·5 and 7·0) did not differ appreciably from earlier study results for the avoidance pH of juvenile S. fontinalis and S. trutta. A comparison of c.i. around these avoidance estimates indicates that avoidance pH is similar among adult S. fontinalis and S. trutta in this study. The limited overlap of c.i. for avoidance pH values for the two species, however, suggests that some S. trutta will display avoidance at a higher pH when S. fontinalis will not. The results of this study indicate that segregation patterns of adult S. fontinalis and S. trutta in Pennsylvania streams could be related to pH and that competition with S. trutta could be mediating the occurrence of S. fontinalis at some pH levels.

trans Arachidonic acid isomers inhibit NADPH-oxidase activity by direct interaction with enzyme components.

NADPH-oxidase is an enzyme that represents, when activated, the major source of non-mitochondrial reactive oxygen species. In phagocytes, this production is an indispensable event for the destruction of engulfed pathogens. The functional NADPH-oxidase complex consists of a catalytic membrane flavocytochrome b (Cytb(558)) and four cytosolic proteins p47(phox), p67(phox), Rac and p40(phox). The NADPH-oxidase activity is finely regulated spatially and temporally by cellular signaling events that trigger the translocation of the cytosolic subunits to its membrane partner involving post-translational modifications and activation by second messengers such as arachidonic acid (AA). Arachidonic acid in its natural cis-poly unsaturated form (C20:4) has been described to be an efficient activator of the enzyme in vivo and in vitro. In this work, we examined in a cell-free system whether a change of the natural cis geometry to the trans configuration, which could occur either by diet or be produced by the action of free radicals, may have consequences on the functioning of NADPH-oxidase. We showed the inability of mono-trans AA isomers to activate the NADPH-oxidase complex and demonstrated the inhibitory effect on the cis-AA-induced NADPH oxidase activation. The inhibition is mediated by a direct effect of the mono-trans AA which targets both the membrane fraction containing the cytb(558) and the cytosolic p67(phox). Our results suggest that the loss of the natural geometric feature (cis-AA) induces substantial structural modifications of p67(phox) that prevent its translocation to the complex.

The role of a photographic atlas in reducing unanticipated healthcare utilization following circumcision.

INTRODUCTION: Circumcision is a common procedure that can evoke caregiver anxiety in the postoperative period due to unfamiliarity with the healing process. To mitigate unnecessary healthcare utilization such as phone calls and unanticipated clinic or emergency department (ED) visits, photographic atlases have been developed to better prepare caregivers for the recovery process. The objective of our study is to further investigate the efficacy of a photographic atlas in its ability to decrease postoperative healthcare utilization using an increased sample size and extended study period compared to previous studies. MATERIALS AND METHODS: In this study, we compared a prospective intervention cohort of patients undergoing circumcision at our institution who received a photographic atlas during postoperative teaching to a retrospective cohort of patients who had not received it. Our primary outcome was unanticipated healthcare utilization, defined as postoperative telephone calls and unanticipated presentations to the urology clinic or ED. RESULTS: The retrospective no-atlas cohort included 105 patients, and the prospective intervention atlas cohort included 80 patients. Both groups were similar with respect to age (p = 0.47) and other demographics. There was no statistically significant difference in healthcare utilization between the no-atlas and atlas cohort. Specifically, we identified no difference in the number of phone calls to clinic staff (12 [11.4%] vs. 11 [13.8%], p = 0.64) or unanticipated postoperative clinic or ED visits (2 [1.9%] vs. 4 [5.0%], p = 0.41). DISCUSSION: The use of a photographic atlas as part of caregiver support for circumcision patients did not demonstrate a statistically significant reduction in either postoperative phone calls or clinic/ED visits. The decrease in absolute number of caregiver phone calls was minimal (12-11), with a small increase in follow-up presentations (2-4). The lack of significant change may be due to the already infrequent occurrence of these events following circumcision, as demonstrated by the no-atlas cohort. Other potential advantages of the atlas, such as improved caregiver confidence and satisfaction, may have been present, but were not measured in this study. CONCLUSIONS: Adding to the mixed results of previous studies, these findings do not support that photographic atlases decrease unanticipated healthcare utilization in children undergoing a circumcision. However, utilization was found to be low. Additionally, further studies are needed to determine other significant benefits of this form of education, such as improved caregiver confidence and satisfaction.

Omega 6 polyunsaturated fatty acids in red blood cell membrane are associated with xerostomia and taste loss in patients with breast cancer.

Chemosensory and physical complaints are common disorders in cancer patients under chemotherapy treatments that may affect the food intake, leading to a decreased quality of life. Lipid metabolism is a major pathway of cancer proliferation, where erythrocyte membrane phospholipids and their fatty acid composition are promising tools for monitoring metabolic pathways. Relationship between lipid profile in erythrocyte membrane phospholipids and chemosensory alterations in 44 newly diagnosed patients with breast cancer was here investigated. Smell changes and xerostomia were the most common complaints, with xerostomia as the main influencing factor on the development of other taste disorders. Lipid profiles revealed significant negative correlation between diminution of linoleic acid levels and xerostomia as well as positive correlation between increased arachidonic acid and salty taste. The involvement of these polyunsaturated lipids suggests the importance of oxidative and nutritional conditions of cancer patients, which can affect the molecular status for taste signals.

Wine lees modulate lipid metabolism and induce fatty acid remodelling in zebrafish.

This study investigates the ability of a polyphenolic extract obtained from a wine lees by-product to modulate zebrafish lipid metabolism. Lees from a Spanish winery were collected and the polyphenolic extract was chemically characterised in terms of antioxidant capacity, total phenolic content and the individual main phenolic compounds. The effects of the extract on lipid metabolism were evaluated using a zebrafish animal model. Lees are rich in polyphenols (42.33 mg gallic acid equivalent per g dry matter) with high antioxidant capacity (56.04 mg Trolox equivalent per g dry matter), rutin and quercetin being their main identified polyphenols. The biological effects of lees extract included (i) a reduction in zebrafish embryos' fat reserve (40%), (ii) changes in the expression of lipid metabolism key genes, (iii) remodelling of the fatty acid content in phospholipid and triglyceride fractions of zebrafish embryos and (iv) reduction in the trans fatty acid content. On the whole, wine lees polyphenolic extract was effective at modulating zebrafish lipid metabolism evidencing remodelling effects and antioxidant properties that can be further developed for food innovation.

Fatty acid-related modulations of membrane fluidity in cells: detection and implications.

Metabolic homeostasis of fatty acids is complex and well-regulated in all organisms. The biosynthesis of saturated fatty acids (SFA) in mammals provides substrates for ß-oxidation and ATP production. Monounsaturated fatty acids (MUFA) are products of desaturases that introduce a methylene group in cis geometry in SFA. Polyunsaturated fatty acids (n-6 and n-3 PUFA) are products of elongation and desaturation of the essential linoleic acid and α-linolenic acid, respectively. The liver processes dietary fatty acids and exports them in lipoproteins for distribution and storage in peripheral tissues. The three types of fatty acids are integrated in membrane phospholipids and determine their biophysical properties and functions. This study was aimed at investigating effects of fatty acids on membrane biophysical properties under varying nutritional and pathological conditions, by integrating lipidomic analysis of membrane phospholipids with functional two-photon microscopy (fTPM) of cellular membranes. This approach was applied to two case studies: first, pancreatic beta-cells, to investigate hormetic and detrimental effects of lipids. Second, red blood cells extracted from a genetic mouse model defective in lipoproteins, to understand the role of lipids in hepatic diseases and metabolic syndrome and their effect on circulating cells.

Fatty acid composition of muscle tissue measured in amphibians living in radiologically contaminated and non-contaminated environments.

Fatty acid composition was identified as a potential biological indicator of the effects of environmental exposure to radiological contaminants. This end point was measured in muscle tissues of Mink frogs ( Rana septentrionalis ) obtained from a radiologically contaminated pond and from a non-contaminated pond. It was also measured after the frogs obtained from both ponds were exposed to a 4 Gy (60)Co γ radiation dose delivered in vivo at a dose rate of approximately 8 Gy/min. Statistically significant differences for the increase of a couple of polyunsaturated omega-3 fatty acid residues and the decrease of a polyunsaturated omega-6 fatty acid residue were observed between radiologically contaminated and non-contaminated frogs, indicating a partial remodeling of muscle lipids in response to a chronic low-dose tritium exposure. The effects of an acute high-dose exposure to (60)Co γ radiation, either for the radiologically contaminated or non-contaminated frogs indicated fast post-irradiation fatty acid changes with an increase of polyunsaturated and decrease of saturated fatty acid contents. Fatty acid composition was found to be a sensitive marker that may be useful to study and monitor biota health in environments that are radiologically contaminated, as well as for understanding the differences between low chronic and high acute stress responses.

Thiyl radicals in biosystems: effects on lipid structures and metabolisms.

Thiyl radicals are intermediates of enzyme- and radical-driven biochemical processes, and their potential as reactive species in the biological environment has been somehow underestimated. From organic chemistry, however, it is known that thiyl radicals isomerize the double bonds of unsaturated fatty acids to a mixture with very dominating trans isomers. Recently, this reaction has been particularly studied for biosystems, focusing on the effect of thiyl radicals on the natural all-cis double bonds of unsaturated phospholipids, which undergo a conversion to the unnatural trans form. In this paper we report briefly the role of thiyl radicals in biosystems, describe the main features of the radical-induced cis-trans isomerization process under both in vitro and in vivo conditions, and reflect on some consequences for membrane structures, lipid metabolism and enzymatic reactions.

Cis-trans isomerization of polyunsaturated fatty acid residues in phospholipids catalyzed by thiyl radicals.

Phospholipids containing trans-unsaturated fatty acid residues are the major products of the thiyl radical attack on L-alpha-phosphatidylcholine from soybean lecithin in homogeneous solution or in liposomes (LUVET). Thiyl radicals act as the catalyst for the cis-trans isomerization, and the number of catalytic cycles depends on the reaction conditions. The presence of approximately 0.2 mM oxygen does not influence the reaction outcome but accelerates the efficiency of cis-trans isomerization in homogeneous solution. Under these conditions, the PUFA peroxidation is found to be unimportant. A detailed study of the isomerization of methyl linoleate including product studies indicates the formation of a small amount of conjugated dienes that act as inhibitors. Indeed, all-trans-retinol substantially retarded the isomerization process.

Suppression of puerperal lactation by terguride. A double-blind study.

Clinical efficacy, prolactin (PRL)-lowering effect and tolerance of terguride (an 8-alpha-ergoline derived from Lisuride which acts as a partial dopaminergic agonist) were investigated in a double-blind study on inhibition of puerperal lactation using three different daily doses of the drug (0.25, 0.5 and 1.0 mg). With 0.5 and 1.0 daily therapeutical regimens PRL levels were suppressed in a dose-dependent manner and lactation was prevented. Terguride was highly well tolerated.