Omega-3 essential fatty acids modulate initiation and progression of neurodegenerative disease.

The significance of the selective enrichment in omega-3 essential fatty acids in photoreceptors and synaptic membranes of the nervous system has remained, until recently, incompletely understood. While studying mechanisms of cell survival in neural degeneration, we discovered a docosanoid synthesized from unesterified docosahexaenoic acid (DHA) by a 15-lipoxygenase (15-LOX), which we called neuroprotectin D1 (NPD1; 10R,17S-dihydroxy-docosa-4Z,7Z,11E,13E,15E,19Z hexaenoic acid). This lipid mediator is a docosanoid because it is derived from the 22 carbon (22C) precursor DHA, unlike eicosanoids, which are derived from the 20 carbon (20C) arachidonic acid (AA) family member of essential fatty acids. We discovered that NPD1 is promptly made in response to oxidative stress, as a response to brain ischemia-reperfusion, and in the presence of neurotrophins. NPD1 is neuroprotective in experimental brain damage, in oxidative-stressed retinal pigment epithelial (RPE) cells, and in human brain cells exposed to amyloid-beta (Abeta) peptides. We thus envision NPD1 as a protective sentinel, one of the very first defenses activated when cell homeostasis is threatened by imbalances in normal neural function. We provide here, in three sections, recent experimental examples that highlight the specificity and potency of NPD1 spanning beneficial bioactivity during initiation and early progression of neurodegeneration: (1) during retinal signal phototransduction, (2) during brain ischemia-reperfusion, and (3) in Alzheimer's disease (AD) and stressed human brain cell models of AD. From this experimental evidence, we conclude that DHA-derived NPD1 regulation targets upstream events of brain cell apoptosis, as well as neuro-inflammatory signaling, promoting and maintaining cellular homeostasis, and restoring neural and retinal cell integrity.

Biotransformation in vitro of the 22R and 22S epimers of budesonide by human liver, bronchus, colonic mucosa and skin.

The pharmacological effects of glucocorticoids are greatly influenced by their pharmacokinetic properties. In the present report, the in vitro biotransformation of the 22R and 22S epimers of the topical steroid budesonide was studied in the S-9 fraction of human liver, bronchus, skin and colonic mucosa. The disappearance of unchanged epimers of budesonide was measured during 90 min of incubation by high performance liquid chromatography. The rate of disappearance was high in human liver while little biotransformation occurred in bronchial tissue and colonic mucosa, and none was detected in the skin. A marked decay of the initial concentration of unchanged budesonide epimers was noticed after 2 h incubation in cultured human hepatocytes, while only a small decrease was observed after 24 h incubation in cultured human airway smooth muscle cells and BEAS-2B cells. The 22R epimer of budesonide suffered greater in vitro biotransformation than the 22S epimer in human hepatic, bronchial and colonic tissues. These findings extend those of other studies, and confirm that the high therapeutic ratio of budesonide is due to negligible local biotransformation combined with high level of liver metabolism for locally absorbed budesonide.

Pollinosis to Ricinus communis (castor bean): an aerobiological, clinical and immunochemical study.

BACKGROUND: Ricinus communis (castor bean) is a species included into the Euphorbiaceae family, common to all the warm regions of the world. Although the allergenicity of its seed is well known, references are scarce regarding the role played by its pollen as a pneumo-allergen. OBJECTIVES: To carry out an aerobiological study of this pollen in the Málaga area (southern Spain); describe the physicochemical characteristics of its most relevant allergens; and to demonstrate the existence of patients with respiratory allergy due to this pollen. METHODS: A Burkard spore trap was used for the aerobiological study from 1992 to 1996. Skin prick tests with castor bean pollen extract were performed to 1946 patients with rhinitis and/or asthma. Specific IgE levels were measured in castor bean-positive SPT patient sera. Immunochemical characterization of the most relevant allergens was performed using electrophoretic techniques. In vitro cross-reactivity studies using positive patient sera were carried out. Nasal challenge tests were done in 32 subjects randomly selected from the sensitized patient group. RESULTS: Castor bean is a perennial pollen with total annual pollen levels never exceeding 1%. One hundred and eighteen (7.7%) patients showed positive prick test (74 rhinitis, 36 rhinitis and asthma, eight asthma). Nine were monosensitized. Specific IgE levels were > or =0.35 PRU/mL in 39 (33%) of patient sera. Nasal challenge test: 10 subjects presented non-specific nasal hyperactivity, 15 were positive and seven negative. The molecular masses and isoelectric points of the main IgE-binding proteins, ranged from approximately 67-15.5/14.5 kDa and approximately 4.5-5.5, respectively. Profilin of the extract was purified by poli-L-proline-Sepharose chromatography and it appeared as one of the most frequent allergens. CONCLUSION: Castor bean pollen is an allergen which causes respiratory (mainly nasal) symptoms.

Sensitization to Zygophyllum fabago pollen. A clinical and immunologic study.

Zygophyllum fabago is a herbaceous plant found widely in the Mediterranean area. There are no previous reports of its allergenicity. An aerobiologic and clinical survey was conducted in Murcia, southern Spain, to determine the quantity of airborne pollen and establish the possible role of this pollen as a cause of allergic symptoms. With a Hirst volumetric trap, we determined the atmospheric concentrations of this pollen in 1993, 1994, 1995, and 1996. Of 1180 patients tested, 181 (15.34%) had a positive skin test. To determine its allergenicity, we divided 47 patients into three groups: in group 1, all the patients had symptoms of rhinoconjunctivitis plus asthma; in groups 2 and 3, rhinoconjunctivitis. In group 1, we performed a bronchial provocation test (BPT); in groups 2 and 3, we performed nasal provocation (NPT) and conjunctival provocation (CPT) tests, respectively. SDS-PAGE was used to characterize the antigenic fractions and RAST inhibition to determine cross-reactivity with other pollens. The pollen dispersion period is from May to September (445 grains/m3). BPT was positive in 13 of 15 patients, NPT in 14 of 16 patients, and CPT in 13 of 16 patients. RAST inhibition revealed cross-reactivity with Mercurialis, Ricinus, Olea, and Betula. SDS-PAGE identified 25 IgE antibody-binding components, five of which (60, 65, 41, 38, and 15.5/14.7 kDa) were recognized by 40% of the sera. By SDS-PAGE immunoblotting with sunflower antiprofilin rabbit serum and affinity chromatography we established that the Z. fabago extract has profilin. This study shows that this pollen becomes airborne and elicits an IgE response which triggers respiratory symptoms in allergic subjects.

Study of the possible crossed reactivity between D. pteronyssinus and non pyroglyphide acarus. 1. Skin tests and FAST inhibition.

On 132 patients with case history of rhinitis and/or asthma in a domestic environment and with positive cutaneous tests contrasted with D. pteronyssinus, we have made cutaneous tests compared to said antigen and compared with D. farinae, L. destructor and A. siro, with extracts 5000 E/ml (Noon Units), as well as FAST inhibition, using D. pteronyssinus in its solid phase and all the above mentioned extracts in their liquid phase. Our results show that the frequency of D. pteronyssinus positivities in prick is greater than the other mites as well as the intensity of the response expressed in the size of the wheal showing significant differences between those found for D. pteronyssinus and those obtained with other mites. In turn those obtained with the D. farinae are significantly greater than those obtained with non-pyroglyphide mites. In FAST inhibition we only found a good correlation for D. pteronyssinus-D. pteronyssinus and D. pteronyssinus-D. farinae and there is no good correlation between the other mites. The correlation coefficients differ significantly except for those of the pyroglyphides, and the regression equations show a lack of parallelism in the regression lines. Consequently, on the basis of this study, we conclude that there is no crossed reactivity between D. peteronyssinus and non-pyroglyphide mites.