Effects of fish oil fatty acids on plasma lipids and lipoproteins and oxidant-antioxidant imbalance in healthy subjects

The purpose of this study was to investigate the effect of eicosapentaenoic and docosahexaenoic acids on plasma lipids and lipoproteins, lipid peroxidation and antioxidant status in healthy humans. A total of 19 healthy volunteers consumed 6 g/day Maxepa fish oil for 3 weeks (1.8 g n-3 fatty acids/day). At baseline and at day 21, we evaluated plasma lipoproteins, plasma and low-density lipoprotein fatty acids, lipid peroxidation markers (malondialdehyde concentration, low-density lipoprotein peroxidation in vitro), and the content of a number of antioxidants (reduced and oxidized glutathione in whole blood, plasma and erythrocyte glutathione peroxidases, plasma vitamin E and beta carotene). Plasma concentrations of total cholesterol, triglycerides, phospholipids, low-density lipoprotein cholesterol and low-density lipoprotein size did not differ significantly after 3 weeks of supplementation. Adding the fish oil to the diet increased the concentration of n-3 very-long-chain polyunsaturated fatty acids and decreased the concentration of n-6 fatty acid and oleic acid in plasma and low-density lipoprotein. Eicosapentaenoic and docosahexaenoic acid supplementation caused elevated values of the high-density lipoprotein cholesterol due to an increment of the high-density lipoprotein 2 fraction and reduced low-density lipoprotein peroxidation rate in vitro. However, we observed an imbalance between oxidizable substrates and antioxidants with an increased lipid peroxidation, whereas the content of reduced glutathione and beta carotene decreased without any variation in vitamin E. Association of antioxidants with n-3 PUFA could prevent lipid peroxidation and enhance the antiatherogenic effects of n-3 polyunsaturated fatty acids.

UV-A1 cytotoxicity and antioxidant defence in keratinocytes and fibroblasts

The levels of antioxidant molecules and lipid peroxidation, under basal conditions, were measured in normal, human cutaneous keratinocytes and fibroblasts. Total glutathione, glutathione peroxidase and superoxide dismutases are significantly higher in normal keratinocytes compared to normal fibroblasts (respectively +248%, +193% and +155%). Under the same conditions, lipid peroxidation is significantly lower in basal keratinocytes compared to fibroblasts. UV-A1 cytotoxicity was investigated in both cutaneous cell types showing that diploid keratinocytes are more resistant to UV-A1 oxidative stress than fibroblasts (by a factor of around 8). We studied the same parameters in two keratinocyte cell lines, NCTC2544 and HaCaT cells, and in MRC5 fibroblasts. Antioxidant content and lipid peroxidation under basal conditions are quite different in these cell lines compared to those of the normal corresponding cells. Furthermore, NCTC2544 keratinocytes are more sensitive to UV-A1 radiation than normal keratinocytes whereas HaCaT keratinocytes are more resistant, and MRC5 fibroblasts are more resistant than normal cutaneous fibroblasts. These findings suggest that (i) cultured epidermal and dermal cells have different sensitivities to UV-A1 radiation that may be linked to different antioxidant capacities and (ii) cell line response to UV-A1 radiation may differ from that of normal cells.

[Salmonella enteritidis septicemia manifesting as a suppurated thrombophlebitis]

BACKGROUND

Non-typloid salmonella can cause septicemia and extradigestive disorders in immunodepressed adults. These frequent diseases can be life-threatening.

CASE REPORT

A 76-year-old woman was treated with corticosteroid therapy for 1 year for suppurated thrombophlebitis of the right greater saphenous vein. Weight loss, fever at 41 degrees C and Salmonella enterididis isolated from blood cultures and skin samples led to the diagnosis of septicemia with multiple septic foyers including the venous endothelium and surrounding soft tissue.

DISCUSSION

In Western countries, there has been an uprise in the frequency of low-grade salmonella infections by food poisoning usually causing acute diarrhea. S. enterididis can also cause severe infectious syndromes with multiple septic localizations, main in patients with a compromised immune reaction. In our cases, Salmonella enteritidis septecemia was revealed by an unusual situation. In the literature, inaugural signs usually involve the heart or arteries, but our patient had isolated foyers involving the superficial venous network. This is exceptional especially since there was no iatrogenic venous catheter insult. For our patient, favoring factors were the long-term corticosteroid therapy and altered venous network. The portal of entry could not be clearly identified but the discovery of a sigmoid diverticulosis would be an argument favoring a digestive origin. Medical and surgical management with resection of the necrosed tissues and two adapted antibiotics in a long-term regimen led to a successful outcome.

Diagnosis of photosensitivity to flupenthixol by photoprick testing

We report the case of a 38-year-old patient with an erythematous eruption, initially confined to photo-exposed areas and then becoming more generalized, which was attributable to flupenthixol, a thioxanthene derivative used for its neuroleptic properties. The compound has the same polycyclic aromatic hydrocarbons as phenothiazines, but without any cross-reaction in our patient. A photoallergic cause for the eruption was verified on clinical, histological and photobiologic grounds. Photopatch tests were negative, but photoprick testing was positive after UV irradiation of the test site. Photopatch test methods using better skin penetration have been already reported for testing drug photosensitivity. Photoprick testing combines better penetration with greater ease of use.

Thiols and selenium: protective effect on human skin fibroblasts exposed to UVA radiation

The sensitivity of human dermal fibroblasts to UVA radiation has been linked to a decrease in intracellular glutathione (GSH) levels. GSH (gamma-glutamyl-cysteinyl-glycine) is a radical scavenger and a cofactor for protective enzymes such as selenium-dependent GSH peroxidases. In this study, we examine the possibility of a cooperative interaction between three cysteine delivery systems and selenium in protecting human cultured fibroblast exposed to UVA radiation. Cells were irradiated (9, 15 and 20 J cm-2) following incubation with N-acetyl-cysteine (NAC, 5 mM), N-acetyl-homocysteine-thiolactone (citiolone (CIT), 1 mM) or L-2-oxothiazolidine-4-carboxylate (OTC, 1 mM). The modulation of the intracellular GSH levels by the addition of the different compounds was determined by enzymatic and separative methods. Cells were harvested for survival analysis by measuring the ability of the cell to adhere and proliferate. Treatments with NAC and CIT resulted in a significant rise in GSH levels compared with control cells, with protection against UVA radiation. OTC did not induce any rise in GSH level; nevertheless, the protective effect afforded by OTC is similar to that observed with NAC and CIT. Moreover, selenium (0.1 mg 1-1), as sodium selenite, significantly increased the protective efficiency of NAC and CIT, but not of OTC. Although the precise mechanism is not known, thiol molecules can inhibit the deleterious effects of UVA radiation. These results provide evidence that compounds capable of inducing GSH synthesis can act with selenium to protect cells against UVA damage.

[Screening for cutaneous carcinoma]

Skin carcinoma is the most frequent of all cancers. The main risk factor is represented by solar exposition and, so, individuals with special risk are xeroderma pigmento sum (enzymatic defect of DNA repair), light phototype person, sun-seekers, outdoor-workers and patients treated with high doses of PUVA. X-rays, mineral oils, tar and arsenic are also known skin carcinogens. HPV can also participate to skin carcinogenis alone or associated with UV particularly in immunosupressed sujets. Subjects with predisposition for skin carcinoma can be pointed out and cautioned. Detection of preepitheliomatous lesions is easy; actinic keratosis are the main signs.

Does manganese protect cultured human skin fibroblasts against oxidative injury by UVA, dithranol and hydrogen peroxide?

Reactive oxygen species (ROS) are involved in the mechanism of photoaging and carcinogenesis. Skin is endowed with antioxidant enzymes including superoxide dismutases (SOD): cytosolic copper zinc SOD and mitochondrial manganese SOD. The aim of our study was to estimate the protective effect of manganese against oxidative injury on cultured human skin fibroblasts. Dithranol, hydrogen peroxide and UV-A radiation (375 nm) were employed as oxidative stressors. The supply of manganese chloride produced an increase in cellular content of this element up to 24 fold without concomitant elevation of MnSOD activity. Nevertheless, manganese protects cells against two of the three ROS generating systems assessed, namely hydrogen peroxyde and UV-A. This protective effect depends on the concentration of manganese in the medium, 0.1 mM and 0.2 mM protect against UVA cytotoxicity, only 0.2 mM protects against H2O2 cytotoxicity.

Protective effect of selenium and zinc on UV-A damage in human skin fibroblasts

Ultraviolet A radiation participates in cytotoxicity and carcinogenesis of the skin by a mechanism involving the generation of reactive oxygen species. Endogenous antiradical defense systems utilize metalloenzymes including Se-dependent glutathione peroxidase and Cu and Zn superoxide dismutase. The aim of the present work was to determine the protective effect of two trace elements, Se and Zn, on cultured human diploid fibroblasts exposed to UV-A radiation (broad-spectrum source with a maximum intensity at 375 nm). Selenium in the culture medium (0.1 mg/L) in the form of sodium selenite increased the synthesis and activity of glutathione peroxidase by 60.5% in the absence of exposure to UV-A radiation and by 35% after irradiation with 5 J/cm2 (P = 0.043). The presence of this element significantly increased the survival of UV-A-irradiated fibroblasts (P < 0.0001). This confirms the essential role of Se in the detoxifying activity of the enzyme. In addition, thiobarbituric acid-reacting substances (TBAR), which are lipid peroxidation markers, decreased in the presence of exogenous Se: -19% and -22% without irradiation and after irradiation with 5 J/cm2 (P = 0.056). When Zn was added at the dose of 6.5 mg/L as ZnCl2, fibroblasts subjected to oxidizing stress induced by UV-A were protected from cytotoxicity (P < 0.0001). The TBAR production decreased significantly: -33% without irradiation and -34% after irradiation with 5 J/cm2 (P = 0.008). Superoxide dismutase activity, however, decreased after supplementing with Zn: -26% without irradiation and -20% after UV-A irradiation (P = 0.017). The antioxidant properties of Zn are thus apparently independent of superoxide dismutase activity.

Effect of zinc supplementation on resistance of cultured human skin fibroblasts toward oxidant stress

In purified system zinc has been shown to have an antioxidant role. Its effects on the resistance of cultured cells towards oxidative stress in vitro were examined. Diploid human skin fibroblasts were grown for 21 d in culture media (RPMI 1640 containing 15% fetal calf serum) added with different zinc (Zn) concentrations (100, 125, and 150 microM as Zinc chlorur ZnCl2). In comparison, cell controls were grown in standard culture media (6.5 microM Zn). The intracellular zinc levels of treated fibroblasts increased from 3- to 7-fold (2330 +/- 120 ng/mg protein in 150-microM Zn-treated cells versus 331 +/- 21 ng/mg protein in control cells). The intracellular copper increased 3- fold whereas the iron content slightly but not significantly decreased. The index of basal lipid peroxidation measured as thiobarbituric acid reactants (TBARs) of zinc-supplemented cells was lower than that of non zinc supplemented controls (0.89 mumol/g protein in 150 microM Zn-treated cells versus 1.59 mumol/g protein in controls). At these high doses of zinc, fibroblasts expressed lower antioxidant metalloenzymes activities. Diminished TBARs in Zn treated cells tends to support that Zn acts protectively against free radical mediated damage. However when the cells were challenged with extracellular oxidant stresses mediated by hypoxanthine/xanthine oxidase or hydrogen peroxide (H2O2), an increased toxicity in Zn-supplemented cells was observed. When we applied an intracellular oxidative stress as UV-B or UV-A radiation, Zn-treated fibroblasts were more resistant than cells grown in normal medium. If Zn has shown antioxidant effect in some in vitro or in vivo systems our observations clearly demonstrate that this role is not mediated by antioxidant metalloenzymes.

[Treatment of psoriasis by UVB and PUVA phototherapy]

PUVA has definitely proved effective in outbursts of extensive psoriasis vulgaris. Efficacy is enhanced by combination with retinoids. The pharmacokinetics of psoralen, which lead to adjustment of dosage to each case, is a concrete improvement which facilitates treatment. The side-effects of PUVA, and notably the risk of carcinogenesis, are well known and can be alleviated. UVB phototherapy, successfully used for a long time against psoriasis, has benefited from technical advances in the field of artificial sources of UV. In its conventional modality (wide UVB band), the adjunction of greasy excipients is necessary for efficacy. SUP and narrow-band phototherapy (311 nm lamp), more recently developed, are of considerable interest but ought to be further evaluated.

Psoralen plus ultraviolet A in the prophylactic treatment of benign summer light eruption

We report the results of a French multicentre study to evaluate the efficiency of psoralen plus ultraviolet A (PUVA) therapy in the prophylactic treatment of benign summer light eruption (BSLE) and to establish the optimal protocol of radiation. Nine photobiology centres took part in this study; 83 patients (76 of them women) were evaluated. The radiation protocols were as follows: oral psoralen (8-methoxypsoralen; 0.6 mg/kg) was taken at each session; the starting dose of UVA radiation was determined according to skin type, with increments of 0.5 J/cm2 every 2 sessions. The subjects were randomized to receive 10-20 sessions 3 times per week. PUVA therapy was very effective: 68 patients (82%) reported total protection from BSLE. Four patients (5%) showed progress. Only 13% showed no improvement. The satisfactory results were not correlated with either the number of sessions or the J/cm2 of UVA. The intensity of tanning after the PUVA sessions did not appear to predict cure. Thirty-six percent of the patients had adverse reactions to treatment, including erythema, pruritus and triggering of BSLE. However, these effects only required the treatment to be stopped in 2% of the cases (for severe pruritus). The results in the various centres were similar.

[Drug-induced cutaneous photosensitivity. Results of a consensus meeting]

In France, the use of an official drug adverse reaction assessment method is mandatory since 1984. The method proposes various qualifications for chronologic and semiologic criteria without clear limits. The definitions could vary with the nature of the side-effect. We report here the results of a consensus meeting on drug-induced photosensitivity. Dermatologists and experts in pharmacovigilance studied together how the "French method" could apply to the two variances of drug-induced photosensitivity: phototoxicity and photoallergy.

Randomized double-blind multicenter study comparing acitretin-PUVA, etretinate-PUVA and placebo-PUVA in the treatment of severe psoriasis

A randomized double-blind study was designed with 65 patients in order to clarify two points: (1) does addition of a retinoid to psoralen-ultra violet A photochemotherapy (PUVA) of severe psoriasis decrease the UVA energy required to achieve remission, and (2) is there a difference between two retinoids, i.e. etretinate and acitretin. Acitretin-PUVA treatment was significantly superior to placebo-PUVA with respect to several items (decrease in lesional scores after 6 weeks of therapy, number of PUVA exposures, and total dose of UVA until remission). There were also differences between the etretinate-PUVA and placebo-PUVA groups, but only the decrease in lesional scores reached statistical significance.

[Problems posed by the therapeutic use of photosensitizers in dermatology]

Three phototherapeutic regimens with photosensitization are now used in dermatology: PUVA (psoralen + UVA), TUV (crude coaltar + UV), PRT (phototherapy with hematoporphyrin derivative). The efficiency of PUVA and TUV is well known in several dermatoses. PRT is now being tested experimentally. For TUV, the lack of a standardized regimen does not allow a clear-cut evaluation of the therapy. For PUVA, late side-effects, particularly carcinogenicity have to be considered. To improve efficiency and minimize the side-effects of PUVA some procedures, such as association with retinoïds, pharmaco-kinetic studies for individual adaptation of the therapeutic regimen and the use of new less mutagenic psoralens are helpful. The persistent phototoxicity following treatments with hematoporphyrin derivative constitutes the major side-effect observed, for this phototherapy.

Influence of the diet on the plasma kinetics of 8-methoxypsoralen

The plasma kinetics of 8-methoxypsoralen (8-MOP) have been determined in 103 patients treated by PUVA in the routine conditions in which PUVA therapy is carried out in hospital. 8-MOP is taken with breakfast; four types of breakfast were available, which differed by their lipid content; this study showed that the diet has no influence on the bioavailability of 8-MOP.

Comparison between plasma levels of 8-methoxypsoralen and skin photosensitivity: the interest of pharmacokinetic studies during photochemotherapy of psoriasis

The present work compares the time course of 8-methoxypsoralen (8-MOP) plasma levels with that of induced skin photosensitivity. The value of plasma assay as a reflexion of cutaneous concentration of 8-MOP has been definitively demonstrated. This study also shows the importance of pharmacokinetics in the therapy management of ‘poor responders’ to PUVA.

[Occlusive rheoplethysmography in the diagnosis, surveillance and evaluation of the sequela of phlebitis]

Occlusive rheoplethysmography (RPO) constitutes a new method of quantitative tetrapolar rheography. It enables us to assess peripheral venous function by measuring distensibility (symbol of influx = IR greater than 0.6, and of drainage = IV greater than 0.7), and flow (symbol of the drainage flow = IDV greater than 0.5). Deep venous thrombosis in the receptor trunk of the popliteal vein and vena cava reduces the IDB (obstructive syndrome). Isolated thrombosis of the tibial vein modifies only the distensibility (restrictive syndrome). RPO is extremely reliable in the diagnosis of acute venous thrombosis of the receptor trunk, as well as in the diagnoses of tibial thromboses, and so it facilitates the recognition of indicants for phlebography. RPO constitutes a simple, portable, rapid, economical and totally objective examination; its use in the observation of the efficiency of treatments as well as in the quantitative assessment of phlebitic after-effects means that it makes a valuable contribution to the management of venous disorders.