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Mendelian adult-onset leukodystrophies are a spectrum of rare inherited progressive neurodegenerative disorders affecting the white matter of the central nervous system. Among these, cerebral autosomal dominant and recessive arteriopathy with subcortical infarcts and leukoencephalopathy, cerebroretinal vasculopathy, metachromatic leukodystrophy, hereditary diffuse leukoencephalopathy with spheroids, and vanishing white matter disease present with rapidly progressive dementia as dominant feature and are caused by mutations in NOTCH3, HTRA1, TREX1, ARSA, CSF1R, EIF2B1, EIF2B2, EIF2B3, EIF2B4, and EIF2B5, respectively. Given the rare incidence of these disorders and the lack of unequivocally diagnostic features, leukodystrophies are frequently misdiagnosed with common sporadic dementing diseases such as Alzheimer's disease (AD), raising the question of whether these overlapping phenotypes may be explained by shared genetic risk factors. To investigate this intriguing hypothesis, we have combined gene expression analysis (1) in 6 different AD mouse strains (APPPS1, HOTASTPM, HETASTPM, TPM, TAS10, and TAU) at 5 different developmental stages (embryo [E15], 2, 4, 8, and 18 months), (2) in APPPS1 primary cortical neurons under stress conditions (oxygen-glucose deprivation) and single-variant-based and single-gene-based (c-alpha test and sequence kernel association test (SKAT)) genetic screening in a cohort composed of 332 Caucasian late-onset AD patients and 676 Caucasian elderly controls. Csf1r was significantly overexpressed (log2FC > 1, adj. p-value < 0.05) in the cortex and hippocampus of aged HOTASTPM mice with extensive Aβ dense-core plaque pathology. We identified 3 likely pathogenic mutations in CSF1R TK domain (p.L868R, p.Q691H, and p.H703Y) in our discovery and validation cohort, composed of 465 AD and mild cognitive impairment (MCI) Caucasian patients from the United Kingdom. Moreover, NOTCH3 was a significant hit in the c-alpha test (adj p-value = 0.01). Adult-onset Mendelian leukodystrophy genes are not common factors implicated in AD. Nevertheless, our study suggests a potential pathogenic link between NOTCH3, CSF1R, and sporadic late-onset AD, which warrants further investigation., (Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.)

Loratadine, a new nonsedating histamine H1-antagonist, has been shown to inhibit immunologic release of inflammatory mediators in addition to its H1-receptor blocking properties. After oral administration, the agent is metabolized primarily to desethoxycarbonyl-loratadine (DCL). The basic piperidine, DCL, is readily soluble in water, whereas the nonbasic urethane, loratadine, is insufficiently soluble in water for some in vitro investigations. Therefore we used the metabolite, DCL, to study its influence on in vitro leukocyte histamine release (LHR) in 24 allergic and 22 nonallergic subjects. IgE-mediated and calcium ionophore A23187-induced LHR were inhibited by DCL in a dose-dependent fashion (values of drug concentration to induce 30% inhibition after stimulation with inhalant antigen, anti-IgE, concanavalin A, and calcium ionophore A23187 were 6, 8, 5, and 11 mumol/L, respectively). Higher concentrations of DCL caused mediator release in all subjects (n = 45, 30 mumol/L DC: 11% +/- 2% LHR, 100 mumol/L DCL: 35% +/- 1% LHR), abolishing any inhibitory effect of the drug. Rapid onset of inhibition by 10 mumol/L DCL was found in kinetic studies (n = 10). The inhibition of anti-IgE-induced histamine secretion was synergistically increased by simultaneous preincubation of DCL with the potent histamine H2-agonist, FRA-19. Additional data indicate that the inhibition of LHR by DCL might involve biochemical events that occur after cellular Ca++ influx because LHR induced by N-formyl-methionyl-leucyl-phenylalanine or the phorbol ester, 12-O-tetradecanoyl phorbol-12-acetate, was not significantly affected by DCL.

Salmeterol, a long-acting beta 2-adrenoceptor agonist, prevents early and late asthmatic responses in atopic asthmatics and inhibits the release of inflammatory mediators from various cells and tissues. We investigated the effect of salmeterol on in vitro basophil histamine release (BHR). Washed basophil leukocytes from allergic (n = 6) and nonallergic subjects (n = 18) were preincubated for 10 min with different concentrations of salmeterol prior to stimulation with antigens (Ag) and anti-IgE for 45 min. BHR was detected by an automated fluorometric assay. If control BHR (without inhibition) reached > or = 30% of the total histamine content, maximal % inhibition (Imax, mean +/- SEM) and the concentration of salmeterol causing 30% inhibition (IC30, geometric mean) were calculated. At concentrations of between 1 and 100 microM salmeterol, concentration-dependent inhibition of release was found for Ag- and anti-IgE-mediated BHR. The Imax of anti-IgE-mediated BHR reached 46 +/- 16% at 30 microM salmeterol. IC30 values were 12 microM for Ag- and 8 microM for anti-IgE-induced BHR. Higher concentrations of salmeterol induced BHR in all subjects (n = 24, 100 microM: 28 +/- 5% BHR), overlapping the inhibitory effect on BHR. Kinetic studies using 30 microM salmeterol (n = 10) showed > 30% inhibition with short preincubation periods (< 10 s). Salbutamol, an older, widely used beta 2-adrenoceptor agonist, had no effect on IgE-mediated BHR (n = 8). We conclude that salmeterol significantly inhibits IgE-mediated histamine release from human leukocytes in the micromolar range.

The rice weevil (Sitophilus oryzae) is known as a stored product pest. Occupants living in a factory used previously as a granary and known to be contaminated by the rice weevil developed rhinitis and asthma. To study the role of the potential insect allergens, extracts were prepared from whole body and a grain dust of the rice and grain weevil (Sitophilus granarius). The extracts were coupled to cyanogen bromide-activated paper disks. Skin prick tests (SPT) were performed using common inhalant allergens as well as the insect allergen preparations. In cases of a positive SPT, specific serum IgE to the insect products was measured. Histamine release studies with peripheral leukocytes (HR) and studies using immunoblot techniques were performed. Fifteen of 39 subjects living in the infested rooms demonstrated positive SPT to the extracts of insect origin. Histamine equivalent wheal size induced by the whole body extract of the rice weevil required 3-160 micrograms protein/mL. Five of 15 subjects (with positive SPTs) had elevated specific IgE-levels to the insect material. RAST-inhibition studies indicated cross allergenicity between rice and grain weevils, and also between the frass of both beetles. Five of 15 subjects were positive in the HR assay (Ag30, allergen concentration for 30% HR for the whole body extract: range, 10(-3) to 400 micrograms protein/mL, maximum release: 26% to 89%). IgE binding was detected after SDS-PAGE by immunoblot techniques at different locations: 35-38, 54, 67, 70, and > 94 kD.(ABSTRACT TRUNCATED AT 250 WORDS)