<Emphasis Type="Italic">N</Emphasis>-palmitoylethanolamide Prevents Parkinsonian Phenotypes in Aged Mice

Parkinson’s disease (PD) is a neurodegenerative disease characterized by degeneration of dopaminergic neurons. Aging is a major risk factor for idiopathic PD. Several prior studies examined the neuroprotective effects of palmitoylethanolamide (PEA), alone or combined with antioxidants, in a model of PD induced by the dopaminergic toxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Here, we analyzed the pretreatment effect of micronized PEA (PEAm) on neuroinflammation and neuronal cell death in the MPTP model. Male CD mice (21 months of age) were pre-treated for 60 days with PEAm. After this time, they received four intraperitoneal injections of MPTP over a 24-h period and were killed 7 days later. On the 8th day, brains were processed. Pretreatment with PEAm ameliorated behavioral deficits and the reductions in expression of tyrosine hydroxylase and dopamine transporter, while blunting the upregulation of α-synuclein and β3-tubulin in the substantia nigra after MPTP induction. Moreover, PEAm reduced proinflammatory cytokine expression and showed a pro-neurogenic effect in hippocampus. These findings propose this strategy as a valid approach to prevent neurodegenerative diseases associated with old age.     

Specificity of guinea pig liver transglutaminase for amine substrates.

The amine specificity of guinea pig liver transglutaminase, a model enzyme for endo-gamma-glutamine:epsilon-lysin transferases, was explored with the aid of synthetic substrates of high apparent affinities. As exemplified by dansyl- (5-dimethylamino-1-naphthalenesulfonyl), (2,4-dinitrobenzenesulfonyl)-, and (2,4,6-triisopropylbenzenesulfonyl)-cadaverines--each of which showed affinities of approximately 4 x 10(7) M-1--the best amine substrates carried a large hydrophobic substituent attached to an alkylamine side chain of about 7.2 A in length. Altogether, our results point to the importance of a hydrophobic binding region in the enzyme from where the alkyl side chain reaches into a narrow crevice toward the active center and positions the primary amine of the substrate for attacking the carbonyl group of the acyl enzyme intermediate.     

Neuraminidase-induced thrombocytopenia in mice: effects on thrombopoiesis

Previous studies to examine the effects of thrombocytopenia on thrombopoiesis have generally utilized immune-mediated platelet depletion. We have developed a nonimmune model to exclude the possibility that adverse immune-mediated effects have been misinterpreted as the physiological response to stimulation of thrombopoiesis. Thrombopoiesis was examined in mice after induction of thrombocytopenia with a single injection of the nonimmunologic agent neuraminidase (Ndase). Utilizing electron microscopy, we examined platelets and megakaryocytes (MK) obtained 8, 12, 24, 48, 72, 96, and 120 hr after administration of Ndase. Eight to 48 hr after induction of acute, severe thrombocytopenia (mean platelet count less than 50,000/microliters), the medians of the platelet sectional area distributions, as measured morphometrically, were significantly greater than the median platelet sectional area of pooled controls. The maximum median value for platelet sectional area was observed at 24 hr. The largest platelets in these samples contained more profiles of endoplasmic reticulum and Golgi cisternae, and a lower concentration of surface-connected canalicular system, as compared with normal platelets. By 72 hr post-injection of Ndase, virtually all platelets exhibited normal size and organelle complement. Mean platelet volumes, determined by electrical impedance analysis, paralleled the serial changes in platelet sectional areas. MK frequency and ploidy, measured by two-color fluorescence activated flow cytometry, were unchanged 12 and 24 hr following Ndase. At 48 hr, total MK frequency increased significantly (P less than 0.01) from 0.11% to 0.17%, and MK ploidy distribution shifted with a reduction in 16N MK (P less than 0.005) and an increase in 32N MK (P less than 0.01). MK ploidy was maximally altered from normal at 72 hr with increased 32N MK frequency (32.0%, P less than 0.001) and increased 64N MK frequency (2.4%, P less than 0.005). Morphologic and morphometric examination of MK at all time points did not reveal detectable changes from normal in cytoplasmic appearance or size, respectively. Therefore, we have demonstrated marked alterations of morphology and size of platelets, and of MK ploidy, using this nonimmunologic model. These studies further support our previous observations that megakaryocyte ploidy and platelet volume are independently regulated in response to depletion of the circulating platelet mass, and they show that these changes are not dependent upon the mechanism of thrombocytopenia.     

Diet selection of lesser white-fronted geese Anser erythropus at a spring staging area

We studied diet selection of the globally threatened lesser white-fronted goose Anser eythropus at a spring staging area on the island of Hailuoto (64°00'N, 24°45'E), off the western coast of Finland. We determined the diet using droppings, which were collected in late May, when the geese had left the area and migrated northwards. The sample potentially comprised of ejecta from 31 different individuals. Plant idengification was based on visual determination of epidermal fragments. A total of 100 droppings were sampled using a point quadrat method. We calculated the percentage of each idengified taxon in each dropping and related this to the availability of the corresponding taxon in the meadow. We measured preference for each taxon using Chesson's electivity index (ɛ_i) and tested them by bootstrap resampling. The diet contained 9 taxa of the ca 40 available. Almost all dietary items were Monocotyledons (99.9%), mostly grasses (88.7%) including Festuca rubra (43%), Phragmites australis (30%) and Calamagrostis stricta (13%). Only Phragmites (ɛ=0.73, p=0.000), Festuca (ɛ=0.52, p=0.004) and possibly Triglochin palustris (ɛ=0.70, p=0.125) were preferred, all other species were avoided. All preferred species were quite common and other goose species exploit them too. The lesser white-fronted geese preferred large natural meadows that were five times broader than an "average" Bothnian Bay meadow. All forms of mowing and grazing management benefit the restoration of lesser white-fronted goose habitats at the landscape level. Festuca and especially Triglochin benefit from such management. Reeds, Phragmites , whose spread has been the main cause of coastal meadow deterioration, can be controlled by management, but can also be maintained among other vegetation if mowing is less frequent or grazing not too intensive.     

Distribution of substituents in O-(2-hydroxyethyl)cellulose

The distribution of substituents in four samples of O-(2-hydroxyethyl)cellulose has been investigated by methylation analysis. One sample was commercial and the others were prepared under conditions analogous to those used industrially during the hydroxyethylation step in the manufacture of O-ethyl-O-(2-hydroxyethyl)cellulose. The results indicate that the distribution of substituents is similar to that expected for a homogeneous reaction.     

Charge injection and charge storage in lipid multilayers

Charge injection and charge storage in lipid multilayers on top of semiconductors have been studied by measuring the small signal capacitance of the structure as a function of applied dc-voltage. It is shown that the injection of holes (and electrons) into the lipid is a thermally activated process, and that no marked difference exists in charge injection properties of simple fatty acids of different carbon chain lengths around room temperature. The charge injection and charge storage properties could be changed by modifications of the lipids. Incorporation of some unsaturated molecules increase the charge injection, and introduction of lipid soluble substances decreases the possibility to store charge etc. The results of some experiments on this line are reported.