Dietary fatty acids and inflammatory skin disease

[Selected aspects regarding social factors in skin diseases]

Skin diseases are complex and cannot be explained solely by genetic or environmental factors but are also significantly shaped by social influences. This review illuminates the bidirectional relationship between social factors and skin diseases, demonstrating how social determinants such as socioeconomic status, living environment, and psychosocial stress can influence the onset and progression of skin conditions. Simultaneously, it explores how skin diseases can affect individuals' social lives and work capability, leading to a cycle of social withdrawal and further deterioration of the condition. The paper describes the need for a holistic approach in dermatology that goes beyond the biomedical perspective and incorporates social factors to develop effective prevention and treatment strategies. The increasing prevalence of skin diseases in Europe and the expected rise in allergies due to climate change make the consideration of social determinants even more urgent. The findings of this review aim to raise awareness of the complex interconnections between social factors and skin health and contribute to reducing social disparities in skin health.

Assessment of wound healing activity in diabetic mice treated with a novel therapeutic combination of selenium nanoparticles and platelets rich plasma

Diabetic wound healing is sluggish, often ending in amputations. This study tested a novel, two-punch therapy in mice-Selenium nanoparticles (Se NPs) and platelet-rich plasma (PRP)-to boost healing. First, a mouse model of diabetes was created. Then, Se NPs were crafted for their impressive antioxidant and antimicrobial powers. PRP, packed with growth factors, was extracted from the mice's blood. Wound healing was tracked for 28 days through photos, scoring tools, and tissue analysis. Se NPs alone spurred healing, and PRP added extra fuel. Furthermore, when used in combination with PRP, the healing process was accelerated due to the higher concentration of growth factors in PRP. Notably, the combination of Se NPs and PRP exhibited a synergistic effect, significantly enhancing wound healing in diabetic mice. These findings hold promise for the treatment of diabetic wounds and have the potential to reduce the need for lower limb amputations associated with diabetic foot ulcers. The innovative combination therapy using Se NPs and PRP shows great potential in expediting the healing process and addressing the challenges of impaired wound healing in individuals with diabetes. This exciting finding suggests this therapy could change diabetic wound management, potentially saving limbs and improving lives.

An older diabetes-induced mice model for studying skin wound healing

Advances in wound treatment depend on the availability of animal models that reflect key aspects of human wound healing physiology. To this date, the accepted mouse models do not reflect defects in the healing process for chronic wounds that are associated with type two diabetic skin ulcers. The long term, systemic physiologic stress that occurs in middle aged or older Type 2 diabetes patients is difficult to simulate in preclinical animal model. We have strived to incorporate the essential elements of this stress in a manageable mouse model: long term metabolic stress from obesity to include the effects of middle age and thereafter onset of diabetes. At six-weeks age, male C57BL/6 mice were separated into groups fed a chow and High-Fat Diet for 0.5, 3, and 6 months. Treatment groups included long term, obesity stressed mice with induction of diabetes by streptozotocin at 5 months, and further physiologic evaluation at 8 months old. We show that this model results in a severe metabolic phenotype with insulin resistance and glucose intolerance associated with obesity and, more importantly, skin changes. The phenotype of this older age mouse model included a transcriptional signature of gene expression in skin that overlapped that observed with elderly patients who develop diabetic foot ulcers. We believe this unique old age phenotype contrasts with current mice models with induced diabetes.

Evaluation of the Quantitative and Qualitative Alterations in the Fatty Acid Contents of the Sebum of Patients with Inflammatory Acne during Treatment with Systemic Lymecycline and/or Oral Fatty Acid Supplementation

Background. Acne is a dermatosis that involves an altered sebum pattern. Objectives. (1) To evaluate if a treatment based on antibiotics (lymecycline) can alter fatty acids contents of the sebum of patients with acne; (2) to evaluate if oral supplementation of fatty acids can interfere with fatty acids contents of the sebum of patients with acne; (3) to evaluate if there is any interaction in fatty acids contents of the sebum of patients with acne when they use both antibiotics and oral supplementation of fatty acids. Methods. Forty-five male volunteers with inflammatory acne vulgaris were treated with 300 mg of lymecycline per day, with 540 mg of γ-linolenic acid, 1,200 mg of linoleic acid, and 510 mg of oleic acid per day, or with both regimens for 90 days. Every 30 days, a sample of sebum from the forehead was collected for fatty acids' chromatographic analysis. Results. Twelve fatty acids studied exhibited some kind of pattern changes during the study: C12:0, C14:0, C15:0, C16:1, C18:0, C18:1n9c+C18:1n9t, C18:2n6t, C18:3n6, C18:3n3, C20:1, C22:0, and C24:0. Conclusions. The daily administration of lymecycline and/or specific fatty acids may slightly influence some fatty acids levels present in the sebum of patients with inflammatory acne vulgaris.

Effectiveness of conventional drug therapy of plaque psoriasis in the context of consensus guidelines: a prospective observational study in 150 patients

BACKGROUND

Evidence for superior outcome by adhering to therapy guidelines is imperative to their acceptance and adaptation for the optimal management of disease variants.

OBJECTIVE

Comparative study of prospective outcomes in simultaneous consideration of independent variables in groups of 150 patients of plaque psoriasis either treated adhering to or in digression of standard guidelines.

METHODS

The psoriasis area severity index (PASI) and the dermatology life quality index (DLQI), prior to and after three months of uninterrupted therapy were examined in treatment groups among 150 patients. Recovery rates of 75% or more in PASI were compared. Independent variables were also examined for their bearing on the outcome.

RESULTS

The vast majority was early onset disease phenotype. All three treatment regimens when administered in adherence to the guidelines yielded significantly superior rates of defined recovery both in PASI and DLQI. Compromise of the therapeutic outcome appeared in high stress profiles, obesity, female sex and alcohol, tobacco or smoking habit.

CONCLUSION

Conventional drug therapy of plaque psoriasis yields superior outcome by adhering to the consensus guidelines. Psychiatric address to stress must be integral and special considerations for phenotypic/syndromic variants is emphasized for effective therapy of psoriasis.

Acne e dieta: verdade ou mito?

Nos últimos 50 anos, foram publicados inúmeros estudos com a finalidade de comprovar se a dieta está relacionada à etiologia da acne. Embora existam estudos antigos, que são bem difundidos entre os dermatologistas e negam a associação entre acne e dieta, seu delineamento científico é pobre. Recentemente, novos artigos demonstraram evidências contrárias às publicações anteriores. Sendo assim, os autores realizaram esta revisão bibliográfica com o intuito de averiguar se a dieta influencia direta ou indiretamente um ou mais dos quatro pilares etiopatogênicos fundamentais da acne: (1) hiperproliferação dos queratinócitos basais, (2) aumento da produção sebácea, (3) colonização pelo Propionibacterium acnes e (4) inflamação.

Nutrition and nutritional supplementation: Impact on skin health and beauty

Skin acts as a natural barrier between internal and external environments thus plays an important role in vital biological functions such as protection against mechanical/chemical damages, micro-organisms, ultraviolet damage. Nutrition has a critical impact on strengthening skin's capabilities to fight against these multiple aggressions.Nutritional deficiencies are often associated with skin health disorders, while diets can either positively or negatively influence skin condition. More recently, the concept of nutritional supplementation has emerged as a new strategy in the daily practice of dermatology as well as a complementary approach to topical cosmetics in the field of beauty. Focusing on human clinical data, this paper proposes to illustrate the link between skin health and nutrition and to exemplify the beneficial actions of nutritional supplementation in skin health and beauty.

Fatores etiopatogênicos da acne vulgar

A acne vulgar é uma das dermatoses mais freqüentes na população em geral. Encontra-se na literatura grande número de trabalhos científicos referentes sobretudo a sua etiopatogenia. No entanto, dado o grande número de informações geradas a respeito, dificilmente consegue-se reuni-las em entendimento comum. Esta revisão literária foi proposta a fim de abordar os mecanismos etiopatogênicos clássicos da acne vulgar (produção sebácea, hiperqueratinização folicular, colonização bacteriana folicular e inflamação glandular) e o mecanismo coadjuvante principal, a influência hormonal.

Effect of fish oil enriched enteral diet on inflammatory bowel disease tissues in organ culture: differential effects on ulcerative colitis and Crohn's disease

AIM

To investigate the influence of fish oil enriched enteral diet on intestinal tissues taken from Crohn's disease (CD), ulcerative colitis (UC) and non-inflamed non-IBD control patients in vitro.

METHODS

Colonoscopic biopsies from patients with active CD (n = 4), active UC (n = 7), and non-inflamed non-IBD control patients (n = 4) were incubated (three dilutions of 1:20, 1:10, and 1:5) with Waymouth's culture medium and enteral elemental diet (EO28, SHS, Liverpool, UK) modified in the fatty acid composition with fish oil (EF) in an organ culture system for 24 h. In each experimental set-up, incubation with Waymouth's medium alone as control was included. Tissue viability was assessed by adding bromodeoxyuridine (BrdU) to the culture fluid and immunohistochemically staining for BrdU uptake. Cytokine ratio of IL-1ra/IL-1beta (low ratio indicative of inflammation) and production of those cytokines as a percentage of medium control were assayed in the culture supernatant.

RESULTS

Incubation of CD-affected tissue with EF (1:20, 1:10, and 1:5) modestly and non-significantly increased IL-1ra/IL-1beta ratio as compared with medium control (CD 39.1+/-16.1; 26.5+/-7.8, 47.1+/-16.8 vs control 13.0+/-2.2), but incubation of UC-affected tissues increased IL-1ra/IL-1beta ratio significantly in all three dilutions (UC 69.1+/-32.2, P<0.05; 76.1+/-36.4, P = 0.05; 84.5+/-37.3, P<0.02; vs control 10.2+/-3.7). Incubation of non-inflamed non-IBD control tissue did not increase the IL-1ra/IL-1beta ratio in any dilution compared to medium control (69.3+/-47.0, 54.1+/-30.6, 79.4+/-34.0 vs control 76.1+/-37.3). Average percentage production of IL-1beta indexed against medium control was significantly less in UC after EF incubation as compared with CD (UC 24.0+/-4.8 vs CD 51.8+/-8.1; P<0.05). Average percentage production of IL-1ra was markedly higher in UC (135.9+/-3.4) than that in control patients (36.5+/-4.3) (P<0.0001).

CONCLUSION

IBD tissues, after incubation with elemental diet modified in its fatty acid composition with fish oil, show an increase in IL-1ra/IL-1beta cytokine ratio. This effect of omega-3 fatty acid modulation is significantly more marked in UC compared with CD and is accompanied by both a reduction of IL-1beta and increase of IL-1ra. The positive direct anti-inflammatory effect of elemental diet with fish oil in tissue affected with UC suggests dietary treatment of UC may be possible.

Fatty acids, the immune response, and autoimmunity: a question of n-6 essentiality and the balance between n-6 and n-3

The essentiality of n-6 polyunsaturated fatty acids (PUFA) is described in relation to a thymus/thymocyte accretion of arachidonic acid (20:4n-6, AA) in early development, and the high requirement of lymphoid and other cells of the immune system for AA and linoleic acid (1 8:2n-6, LA) for membrane phospholipids. Low n-6 PUFA intakes enhance whereas high intakes decrease certain immune functions. Evidence from in vitro and in vivo studies for a role of AA metabolites in immune cell development and functions shows that they can limit or regulate cellular immune reactions and can induce deviation toward a T helper (Th)2-like immune response. In contrast to the effects of the oxidative metabolites of AA, the longer-chain n-6 PUFA produced by gamma-linolenic acid (18:3n-6, GLA) feeding decreases the Th2 cytokine and immunoglobulin (Ig)G1 antibody response. The n-6 PUFA, GLA, dihomo-gamma-linolenic acid (20:3n-6, DHLA) and AA, and certain oxidative metabolites of AA can also induce T-regulatory cell activity, e.g., transforming growth factor (TGF)-beta-producing T cells; GLA feeding studies also demonstrate reduced proinflammatory interleukin (IL)-1 and tumor necrosis factor (TNF)-alpha production. Low intakes of long-chain n-3 fatty acids (fish oils) enhance certain immune functions, whereas high intakes are inhibitory on a wide range of functions, e.g., antigen presentation, adhesion molecule expression, Th1 and Th2 responses, proinflammatory cytokine and eicosanoid production, and they induce lymphocyte apoptosis. Vitamin E has a demonstrable critical role in long-chain n-3 PUFA interactions with immune functions, often reversing the effects of fish oil. The effect of dietary fatty acids on animal autoimmune disease models depends on both the autoimmune model and the amount and type of fatty acids fed. Diets low in fat, essential fatty acid deficient (EFAD), or high in long-chain n-3 PUFA from fish oils increase survival and reduce disease severity in spontaneous autoantibody-mediated disease, whereas high-fat LA-rich diets increase disease severity. In experimentally induced T cell-mediated autoimmune disease, EFAD diets or diets supplemented with long-chain n-3 PUFA augment disease, whereas n-6 PUFA prevent or reduce the severity. In contrast, in both T cell- and antibody-mediated autoimmune disease, the desaturated/elongated metabolites of LA are protective. PUFA of both the n-6 and n-3 families are clinically useful in human autoimmune-inflammatory disorders, but the precise mechanisms by which these fatty acids exert their clinical effects are not well understood. Finally, the view that all n-6 PUFA are proinflammatory requires revision, in part, and their essential regulatory and developmental role in the immune system warrants appreciation.

Essential fatty acid metabolism and its modification in atopic eczema

Research from the 1930s to the 1950s established that a deficit of n-6 essential fatty acids (EFAs) leads to an inflammatory skin condition in both animals and humans. In a common inherited skin condition, atopic dermatitis (eczema), there was evidence of low blood EFA concentrations and of a therapeutic response to exceptionally high doses of linoleic acid. More recently, it has been established that there is no deficit of linoleic acid in atopic eczema. Concentrations of linoleic acid instead tend to be elevated in blood, milk, and adipose tissue of patients with atopic eczema, whereas concentrations of linoleic acid metabolites are substantially reduced. This suggests reduced conversion of linoleic acid to gamma-linolenic acid (GLA). In most but not all studies, administration of GLA has been found to improve the clinically assessed skin condition, the objectively assessed skin roughness, and the elevated blood catecholamine concentrations of patients with atopic eczema. Atopic eczema may be a minor inherited abnormality of EFA metabolism.

The anhydrous milk fat, ghee, lowers serum prostaglandins and secretion of leukotrienes by rat peritoneal macrophages

Ghee, the anhydrous milk fat, is one of the most important sources of dietary fat in India. Male Wistar rats were fed diets containing 2.5, 5.0 and 10 wt% ghee for a period of 8 weeks. The diets were made isocaloric with groundnut oil. The results showed that serum thromboxane levels decreased by 27-35%, and 6-keto-prostaglandin F1alpha by 23-37% when ghee was incorporated at level of 10% in the diet. Prostaglandin E2 levels in serum and secretion of leukotrienes B4, C4 and D4 by peritoneal macrophages activated with calcium ionophore decreased when increased amounts of ghee from 2.5 to 10% were included in the diet. Arachidonic acid levels in macrophage phospholipids decreased when incremental amounts of ghee were fed to rats. These studies indicate that ghee in the diet not only lowers the prostaglandin levels in serum but also decreases the secretion of leukotrienes by macrophages.

Double-blind, multicentre analysis of the efficacy of borage oil in patients with atopic eczema

Although gamma-linolenic acid (GLA) has been shown to correct deficiencies in skin lipids associated with reduced delta-6-desaturase activity which should result in improvement of dysregulation of inflammation and immunity in atopic eczema, clinical studies with evening primrose oil containing 10% GLA have yielded contradictory results. We have therefore examined the effect of a higher percentage (at least 23%) GLA-containing borage oil in adults with stable atopic eczema of moderate severity in a double-blind, multicentre study. One hundred and sixty patients were randomized to take daily either 500 mg of borage oil-containing capsules or the bland lipid miglyol as a placebo over a 24-week period. Use of topical diflucortolone-21-valerate cream was allowed as rescue medication, with the amount used until response being defined as primary, and clinical improvement as secondary efficacy criteria. Although several clinical symptoms improved compared with placebo, the overall response to borage oil did not reach statistical significance. Significant differences in favour of borage oil were, however, observed in a subgroup excluding patients who failed to show increased erythrocyte dihomo-gamma-linolenic acid levels and in whom adherence to inclusion criteria and the study protocol were questionable. GLA metabolites increased in borage oil-treated patients only, and serum IgE showed a trend to decrease on overall and subgroup analysis. No substance-related adverse effects were observed. This study shows no overall efficacy of GLA-containing borage oil in atopic eczema, with steroid use being the primary response parameter, although it suggests that a subgroup of patients may benefit from this well-tolerated treatment.

Effects of eicosapentaenoic and gamma-linolenic acid on lung permeability and alveolar macrophage eicosanoid synthesis in endotoxic rats

OBJECTIVES

Proinflammatory eicosanoids (cyclooxgenase and lipoxygenase metabolites of arachidonic acid) released by alveolar macrophages play an important role in endotoxin-induced acute lung injury. We investigated the effect of prefeeding rats for 21 days with enteral diets that provided the anti-inflammatory fatty acids, eicosapentaenoic acid and gamma-linolenic acid (derived from fish oil and borage oil, respectively), as compared with an n-6 fatty acid-enriched diet (corn oil) on the following: a) lung microvascular protein permeability, arterial blood pressure, and platelet and white blood cells in a model of endotoxin-induced acute lung injury; b) alveolar macrophage prostaglandin and leukotriene synthesis; and c) liver and alveolar macrophage phospholipid fatty acid composition.

DESIGN

Prospective, randomized, controlled, double-blind study.

SETTING

Research laboratory at a university medical center.

SUBJECTS

Male Long-Evans rats, weighing 250 g.

INTERVENTIONS

Rats were randomized into four dietary treatment groups and fed nutritionally complete diets (300 kcal/kg/day), containing 55.2% of the total calories from fat with either 97% corn oil, 20% fish oil, 20% fish and 5% borage oil, or 20% fish and 20% borage oil for 21 days. On day 22, lung microvascular protein permeability, mean arterial pressure, and platelet and white blood cell counts were determined for 2 hrs after an intravenous injection of Salmonella enteritidis endotoxin (10 mg/kg). In a second group of prefed rats, the phospholipid fatty acid composition was determined in liver and alveolar macrophages. Alveolar macrophages were harvested by bronchoalveolar lavage and stimulated in vitro with a calcium ionophore (A23187), and the concentrations of leukotrienes B4 and B5, thromboxane A2, prostaglandin E2, and 6-keto-prostaglandin F1 alpha were measured in a third group of prefed rats.

MEASUREMENT AND MAIN RESULTS

Lung permeability was greatest with corn oil and was significantly attenuated with 20% fish oil and 20% fish and 5% borage oil, and this effect approached significance with 20% fish and 20% borage oil (p = .06). The early and late hypotensive effects of endotoxin were attenuated with 20% fish oil, 20% fish and 5% borage oil, and 20% fish and 20% borage oil, as compared with corn oil. Concentrations of leukotriene B4, prostaglandin E2, and thromboxane B2 released from A23187-stimulated alveolar macrophages were significantly lower with 20% fish oil and 20% fish and 20% borage oil, as compared with corn oil. The increase in lung microvascular protein permeability with 20% fish and 20% borage oil was not significantly different than the lung microvascular protein permeability that was found in animals receiving 20% fish oil (p = .20) and 20% fish and 5% borage oil (p = .31). Alveolar macrophage and liver phospholipid concentrations of arachidonic acid were lower, and the concentrations of eicosapentaenoic acid and docosahexaenic acid were higher, with 20% fish oil, and 5% borage oil, and 20% fish and 20% borage oil, as compared with corn oil. Dihomo-gamma-linolenic acid, the desaturated and elongated intermediate of gamma-linolenic acid, was increased with 20% fish and 20% borage oil, as compared with 20% fish oil and 20% fish and 5% borage oil.

CONCLUSIONS

The severity of pulmonary microvascular protein permeability and the degree of hypotension were reduced with fish or fish and borage oil diets, as compared with corn oil, in endotoxic rats. The reduced synthesis of the proinflammatory arachidonic acid-derived mediators, leukotriene B4, thromboxane B2, and prostaglandin E2 from stimulated alveolar macrophages was indicative of a decrease in arachidonic acid and an increase in eicosapentaenoic acid and docosahexaenoic acid in cell membrane phospholipids.

Changes of fatty acid composition and oxidative metabolism of human neutrophils migrating into an inflammatory exudate

The peripheral blood neutrophils and the neutrophils accumulated into a skin-window experimental exudate were compared for their ability to release superoxide anion (O2-) and for their fatty acid composition, determined by capillary gaschromatography. The basal O2- release and the phorbol myristate acetate (PMA)-induced O2- release were not significantly different in the two neutrophil populations, while in response to formyl-methionyl-leucyl-phenylalanine (fMLP) the exudate cells showed an activity that was two fold higher than that of blood cells. The most significant changes of fatty acid composition of exudate versus blood cells were the following: i) increase of C16:0 (palmitic acid) from 21.3 +/- 1.2% to 23.5 +/- 1.3% (+ 10.2%) of total fatty acids (p < 0.001),ii) increase of C18:2 (linoleic acid) from 9.3 +/- 1.7% to 11.0 +/- 2.1% (+ 18.3%) (p = 0.005), iii) decrease of C20:4 (arachidonic acid) from 12.8 +/- 1.6% to 10.6 +/- 1.2% (-17.3%) (p < 0.001), whereas C18:1 (oleic acid) did not change. The total content of saturated or unsaturated fatty acids did not change. In exudate cells, a strong negative correlation was found between palmitic acid content and O2- release in response to both fMLP and PMA (r = -0.52, p < 0.02 and r = -0.49, p < 0.05, respectively) whereas arachidonic acid correlated positively, but weakly, with O2- (r = 0.40, p = 0.07 and r = 0.47, p = 0.05, with fMLP and PMA as stimulants respectively). A positive correlation was also found between the arachidonic acid content of blood cells and the number of cells that migrated into the inflammatory exudate. These results indicate that the process of extravasation from blood into the exudate causes specific and consistent modifications of the fatty acid composition of neutrophils and suggest that these modifications have a role in the activation and the regulation of the O2- forming system.

Beneficial effect of eicosapentaenoic and docosahexaenoic acids in the management of systemic lupus erythematosus and its relationship to the cytokine network

Systemic lupus erythematosus (SLE) is a chronic inflammatory condition characterised by arthritis, cutaneous rash, vasculitis, and involvement of central nervous system, renal and cardiopulmonary manifestations. Abnormalities in the cytokine network is believed to be involved in the pathobiology of this condition. The n-3 fatty acids such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) can suppress T-cell proliferation and the production of interleukin-1, interleukin-2, and tumor necrosis factor by these cells both in vitro and in vivo. Oral supplementation of EPA and DHA induced prolonged remission of SLE in 10 consecutive patients without any side-effects. These results suggest that n-3 fatty acids, EPA and DHA, are useful in the management of SLE and possibly, other similar collagen vascular diseases.

Analysis of polyunsaturated fatty acids in newborn sera: a screening tool for atopic disease?

It has been demonstrated that patients with atopic disease have anomalies of fatty acid composition, as a result of altered metabolism or abnormal incorporation of fatty acids into the tissues. In the present study, in 57 newborns 'at risk' for atopic disease, the polyunsaturated fatty acid (PUFA) levels were found to be lower in cord blood in infants who subsequently developed atopic disease than in non-atopics. In all babies, levels of arachidonic acid and dihomo-gamma-linolenic acid in sera at 1 and 3 months of age were lower than those in cord blood. These changes were more marked in children who subsequently developed atopic disease, and in those who, independently of signs and/or symptoms of atopic disease, were formula-fed. A comparison between IgE and PUFA levels revealed no significant differences at any tested time interval. In conclusion, our data suggest that in children 'at risk' for atopy, PUFA levels may be predictive of atopic disease.

Effect of prostaglandins and their precursors on the proliferation of human lymphocytes and their secretion of tumor necrosis factor and various interleukins

Cytokines, released by T cells, participate in inflammation and produce tissue injury. Excess production of cytokines such as interleukins (ILs) and tumor necrosis factor (TNF) is believed to be involved in the pathobiology of conditions such as septicemia and septic shock, collagen vascular diseases, glomerulonephritis etc. On the other hand, prostaglandins (PGs) are known to modulate inflammation, immune response, and T-cell response to antigens. But relatively little information is available on the effects of PGs and PG precursors on the release of cytokines. Here the authors present data which suggests that PGs including thromboxane B2 (TXB2) and their precursors such as dihomo-gamma linolenic acid (DGLA), arachidonic acid (AA) and eicosapentaenoic acid (EPA) can inhibit T-cell proliferation and influence their ability to secrete IL-2, IL-4, IL-6 and TNF in vitro. These results may have relevance to the use of PG-precursors in various inflammatory conditions including collagen vascular diseases.

Evening primrose oil and marine oil in the treatment of psoriasis

The effect of dietary supplementation with a combination of n-3 (marine oil) and n-6 (evening primrose oil) essential fatty acids in the treatment of chronic stable plaque psoriasis was observed. Thirty-seven patients in a double-blind parallel trial were studied. There was no significant improvement in clinical severity of psoriasis or change in transepidermal water loss.

Influence of phospholipid liposomes (PLL) on UVB-induced erythema formation

Application of liposomal phospholipids (Natipide II) caused a significant decrease in erythema induced by UVB (280-312 mm) in patients with skin types II and III (n = 31). In accordance with findings in other organs, e.g. liver, the present findings suggest that phospholipids are capable of reducing H2O2 formation and/or increasing glutathione synthesis in human skin, thus reducing erythema formation by preventing oxidative stress.

The effect of essential fatty acids on epidermal atrophy due to topical steroids

The effect of topical n-6 essential fatty acids in the form of evening primrose oil on the epidermal atrophy caused by a potent topical steroid was studied in 24 normal volunteers by measuring epidermal thickness and cross-sectional area and by histological examination. Epidermal thickness and cross-sectional area were significantly lower in normal forearm skin treated with 0.1% betamethasone valerate twice daily without occlusion for 3 weeks when compared with placebo-treated skin. The addition of evening primrose oil to the topical steroid did not prevent steroid-induced epidermal atrophy suggesting that steroid-induced epidermal atrophy is not mediated by the inhibition of essential fatty acid release from cell membranes.

Placebo-controlled trial of essential fatty acid supplementation in atopic dermatitis

Treatment of atopic dermatitis with essential fatty acids remains controversial. A double-blind, placebo-controlled, parallel-group study was done to investigate the response of patients with atopic dermatitis to essential fatty acid supplements. Patients with atopic dermatitis were randomised to receive evening primrose oil, evening primrose oil and fish oil, or placebo for 16 weeks. Disease activity was monitored by clinical severity scores recorded by the investigator, topical steroid requirement, and symptom scores recorded by subjects. Of 123 subjects recruited, 102 completed the treatment period. No improvement with active treatment was demonstrated. Our study, which avoided the methodological and analytical problems of previous studies, found no effect of essential fatty acid supplementation in atopic dermatitis.

Binding of sulfosuccinimidyl fatty acids to adipocyte membrane proteins: isolation and amino-terminal sequence of an 88-kD protein implicated in transport of long-chain fatty acids

We recently reported (Harmon et al., J. Membrane Biol. 124:261-268, 1991) that sulfo-N-succinimidyl derivatives of long-chain fatty acids (SS-FA) specifically inhibited transport of oleate by rat adipocytes. These compounds bound to an 85-90 kD membrane protein which was also labeled by another inhibitor of FA transport [3H]DIDS (4,4'-diisothiocyanostilbene-2-2'-sulfonate). These results indicated that the protein was a strong candidate as the transporter for long-chain fatty acids. In this report we determined that the apparent size of the protein is 88 kD and its isoelectric point is 6.9. We used [3H]SS-oleate (SSO), which specifically labels the 88-kD protein, to isolate it from rat adipocyte plasma membranes. Identification of 15 amino acids at the N-terminus region revealed strong sequence homology with two previously described membrane glycoproteins: CD36, a ubiquitous protein originally identified in platelets and PAS IV, a protein that is enriched in the apical membranes of lipid-secreting mammary cells during lactation. Antibody against PAS IV cross-reacted with the adipocyte protein. This, together with the N-terminal sequence homology, suggested that the adipocyte protein belongs to a family of related intrinsic membrane proteins which include CD36 and PAS IV.

Influence of dietary fatty acids on cytokine production and its clinical implications

Cytokines and eicosanoids are important biologic mediators with tightly regulated production. Overproduction contributes to pathogenesis of chronic and acute inflammatory, autoimmune, atherosclerotic, and neoplastic diseases. Animal and human studies have shown that production of cytokines and eicosanoids can be reduced by certain dietary fatty acids, specifically those containing long-chain (n-3) polyunsaturated fatty acids (PUFAs). This in turn results in reduction of the severity of certain autoimmune, inflammatory, and atherosclerotic diseases. Because these cytokines are also involved in control of the host defense, substantial reduction in their production could also result in the impairment of normal immune response. Increased intake of (n-3) PUFAs without adequate antioxidant protection could result in increased free radical formation and lipid peroxidation. Thus, when (n-3) PUFAs are used to reduce the pathogenesis of these diseases, its possible adverse effects should be considered and prevented.

Evidence for, and taxonomic value of, an arachidonic acid cascade in the Lipomycetaceae

By using specific inhibitors of the lipoxygenase and cyclo-oxygenase pathways, arachidonic acid metabolites with similar sensitivities towards these inhibitors as in humans, were detected in Dipodascopsis uninucleata. The taxonomic value of aspirin sensitive arachidonic acid metabolites in the Lipomycetaceae was next assessed. No metabolites of which the production is inhibited by aspirin were detected in strains representing the following species: Lipomyces starkeyi, Lipomyces kononenkoae, Lipomyces tetrasporus, Myxozyma melibiosi, Myxozyma mucilagina, Myxozyma kluyveri, Waltomyces lipofer, Zygozyma oligophaga and Zygozyma arxii. The detection of such aspirin sensitive arachidonic acid metabolites in representative strains of Lipomyces anomalus and the genus Dipodascopsis, emphasises the isolated position of these taxa in the genus Lipomyces and the family Lipomycetaceae, respectively. Finally using long chain fatty acid analyses, electrophoretic karyotyping and other phenotypic characters, a phylogenetic scheme is proposed for some genera in the Lipomycetaceae.

Primary and preschool immunisation in Grampian: progress and the 1990 contract

OBJECTIVE

To examine changes in immunisation performance in Grampian region after the introduction of the 1990 contract for general practitioners.

DESIGN

Retrospective descriptive study using data held on the Grampian immunisation record system's computer.

SETTING

All 95 general practices in Grampian region (313 general practitioners).

PATIENTS

All children in the primary immunisation and preschool booster age groups. This formed two groups of children for each of the four calendar quarters of 1990 and first three quarters of 1991 analysed as (a) those aged 2 years on the first day of the relevant quarter and (b) those aged 5 years on the first day of the relevant quarter, with an average population of 6600 and 6400 respectively.

MAIN OUTCOME MEASURE

Percentage immunised by practice.

RESULTS

For primary immunisation the number of practices achieving immunisation rates of at least 95% increased from 29 (31%) to 76 (81%), and practices achieving 90% rates rose from 69 (73%) to 87 (93%). For preschool boosters, the number of practices achieving at least 95% immunisation rates increased from 22 (23%) to 61 (64%). By the end of September 1991, 76 (80%) practices were achieving at least 90% levels compared with 36 (39%) at the beginning of 1990. Since the beginning of 1989 the proportion of immunisations not given by general practitioners declined from 14% to 2%.

CONCLUSIONS

Primary and preschool immunisation rates for preschool children in Grampian showed a sustained improvement during 1990 and consolidation in 1991. Although overall trends were unchanged, 18 months after the introduction of the 1990 contract only one practice failed to meet lower target levels of 70% for both primary and preschool immunisation. By September 1991 more than three out of four practices had reached levels of at least 95% for primary immunisation.

Interaction(s) between essential fatty acids, eicosanoids, cytokines, growth factors and free radicals: relevance to new therapeutic strategies in rheumatoid arthritis and other collagen vascular diseases

Eicosanoids, lymphokines, and free radicals are known to participate in the pathogenesis of inflammation. Tumour necrosis factor (TNF), interleukin-1 and 6 (IL-1 and IL-6) and colony stimulating factor -1 (CSF-1) are secreted mainly by activated macrophages, whereas T-cells secrete IL-2, IL-3, IL-4 and interferon-gamma (IFN-gamma). In addition, activated macrophages and lymphocytes can also produce eicosanoids and free radicals which have potent pro-inflammatory actions. Eicosanoids, lymphokines, and free radicals can modulate the immune response, cell proliferation, stimulate collagenase and proteases secretion and induce bone resorption; events which are known to be associated with various collagen vascular diseases. On the other hand transforming growth factor-beta (TGF-beta) produced by synovial tissue, platelets and lymphocytes can inhibit collagenase production, suppress T-cell and NK-cell proliferation and activation and block free radical generation and seems to be of benefit in rheumatoid arthritis. Drugs such as cyclosporine, 1,25,dihydroxycholecalciferol and pentoxyfylline can block lymphokine and TNF production and thus, may inhibit the inflammatory process. Essential fatty acids, the precursors of eicosanoids, are suppressors of T-cell proliferation, IL-1, IL-2 and TNF production and have been shown to be of benefit in rheumatoid arthritis, systemic lupus erythematosus and glomerulonephritis. Thus, the interactions between essential fatty acids, eicosanoids, lymphokines, TGF-beta and free radicals suggest that new therapeutic strategies can be devised to modify the course of collagen vascular diseases.

Reactive oxygen species, lipid peroxides and essential fatty acids in patients with rheumatoid arthritis and systemic lupus erythematosus

We studied free radical generation, lipid peroxidation and the levels of essential fatty acids and of their metabolites in patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). Both superoxide and hydrogen peroxide generation by peripheral leukocytes but not malondialdehyde levels, as measured by thiobarbituric acid assay, were found to be significantly enhanced both in RA and SLE. Fatty acid analysis of the plasma PL fraction revealed that both LA and ALA metabolites are significantly decreased in RA and SLE compared to controls. These results suggest that essential fatty acid metabolism is altered in RA and SLE.

Supplementation with evening primrose oil in atopic dermatitis: effect on fatty acids in neutrophils and epidermis

We investigated the effect of oral supplementation with evening primrose oil, containing 72% linoleic acid (18:2n-6) and 10% gamma-linolenic acid (18:3n-6), on the epidermal and neutrophil phospholipid fatty acid composition in 15 patients with atopic dermatitis (AD). Three different dose levels, 4, 8 and 12 capsules per day containing 0.5 g oil, were given to three groups of patients. The only n-6 fatty acid showing a significant (p less than 0.05) dose-related increase was dihomo-gamma-linolenic acid (20:3n-6) in neutrophil phospholipids. The highest dose increased dihomo-gamma-linolenic acid by 45% in neutrophil phospholipids, by 46% in lesion-free epidermal phosphatidylcholine, and by 15% in lesion-free epidermal phosphatidylethanolamine. In both lesional and lesion-free epidermis, supplementation resulted in a rise in the ratio between n-6 and monounsaturated fatty acids, reaching significance (p less than 0.05) in lesional epidermis. This study shows that moderate and favorable fatty acid changes can be obtained in the epidermis of AD patients, when given 6 g per day of oil rich in n-6 fatty acids. The abnormal lipid and fatty acid pattern of the atopic epidermis may be involved in the pathogenesis of the disease, and should therefore be the target for future therapeutic approaches with fatty acid supplements.

Reduced neutrophil LTB4 release in atopic dermatitis patients despite normal fatty acid composition

Propositions about an abnormal fatty acid metabolism in atopic dermatitis patients prompted us to compare the phospholipid fatty acid composition and LTB4 release of neutrophils from 15 atopic dermatitis patients, as well as the adipose tissue triglyceride fatty acid composition, to that of 15 healthy controls matched by age, gender, and smoking habits. We found no differences in the tissue fatty acid composition between the two groups. The release of leukotriene B4 from Ca-ionophore-stimulated neutrophils in patients was on the average only 42% (p less than 0.001) of that measured in the control group, despite the very similar arachidonic acid contents of these cells. Our study does not support the assumption of an abnormal fatty acid desaturation in atopic dermatitis patients. Rather, the capacity to release and/or convert arachidonic acid into leukotrienes in neutrophils appears to be affected by this disease.

Effect of fatty acids on the proliferation of concanavalin A-stimulated rat lymph node lymphocytes

1. The effect of a range of fatty acids upon concanavalin A-stimulated [3H]thymidine incorporation into rat lymphocytes was investigated. 2. All fatty acids tested inhibited the response to mitogen but the extent of the inhibition was dependent upon the fatty acid concentration used, the time of addition of fatty acid and the duration of exposure of the cells to fatty acid. 3. All fatty acids were inhibitory at concentrations of 50 microM or above; at lower concentrations some were inhibitory and some were stimulatory. Above 50 microM the inhibitory effect was concentration dependent; the greater the fatty acid concentration, the greater the inhibition. 4. The longer the lymphocytes were exposed to the fatty acid the greater was the inhibitory effect. This was true if the fatty acids were added at the same time as the mitogenic stimulus or if they were added before or after the stimulus. Some fatty acids maintained their inhibitory effect when added 24 or 48 hr after the mitogenic stimulus. 5. Generally unsaturated fatty acids were more inhibitory than saturated fatty acids; the greatest inhibition of proliferation was caused by eicosapentaenoate and arachidonate and the least inhibition by myristate and palmitate. 6. Inhibition was greater in the absence of serum. 7. Inhibition by unsaturated fatty acids could be partially or totally relieved by addition in combination with myristate or palmitate, suggesting that the inhibitory effect of fatty acids may be due to alteration of membrane fluidity caused by an imbalance of fatty acids presented to the cells. 8. PGE2 levels were similar in the medium of cells grown in the presence of fatty acids with varying inhibitory effects, indicating that PGE2 production is not the sole mechanism of suppression of the proliferative response. 9. Although the mechanism by which fatty acids exert their effect remains to be determined, these results indicate that lymphocyte proliferation and so an immune response could be influenced by dietary lipid manipulation.