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Background: H1-antihistamines (H1AH) are the first-line treatment for chronic spontaneous urticaria (CSU), but 50% of patients have inadequate disease control at standard doses. Objective: To assess the comorbidity burden and healthcare resource utilization (HRU) associated with non-response to H1AH-based treatments; to identify predictors of non-response. Methods: Optum® de-identified Electronic Health Record dataset (2007–2020) was used to identify adult patients with CSU who initiated a H1AH, alone or in combination with other oral non-biologics (index treatment). Based on twelve-month treatment patterns observed after index treatment initiation, patients were categorized as responders (continued index treatment or had only 1 next H1AH treatment without corticosteroids) or non-responders (continued corticosteroids or had 2 or more treatment switches). Patient characteristics and HRU were assessed in the 12 months before (baseline) and ≥12 months after (follow-up) index treatment initiation. Baseline predictors associated with non-response were identified using machine learning. Results: There were 17 062 patients who met inclusion criteria, and 14824 (86.9%) were classified as non-responders. A higher proportion of non-responders had records of CSU-related symptoms, comorbidities, polypharmacy, and certain laboratory tests than responders at baseline. A higher proportion of non-responders than responders visited an allergist or dermatologist during follow-up (59.5% vs 53.0%). Non-responders had a larger increase in hospitalizations (15.7% vs −2.4%) than responders during follow-up vs baseline. Predictors of non-response included index and baseline treatment classes, types of specialists seen, chronic pulmonary disease, depression, and female sex. Conclusion: A large proportion of CSU patients treated with H1AH-based therapies had uncontrolled disease, contributing to increased HRU and patient burden. Non-responders had more comorbidities and HRU at baseline and follow-up, with steep increases in follow-up hospitalizations relative to baseline, highlighting an urgent need for early disease control.

Cytochrome P450 (CYP)-derived epoxyeicosatrienoic acids (EETs) exhibit potent cardiovascular protective effects in preclinical models, and promoting the effects of EETs has emerged as a potential therapeutic strategy for coronary artery disease (CAD). The relationship between circulating EET levels and CAD extent in humans, however, remains unknown. A panel of free (unesterified) plasma eicosanoid metabolites was quantified in 162 patients referred for coronary angiography, and associations with extent of CAD [no apparent CAD (N = 39), nonobstructive CAD (N = 51), and obstructive CAD (N = 72)] were evaluated. A significant relationship between free EET levels and CAD extent was observed (P = 0.003) such that the presence of obstructive CAD was associated with lower circulating EET levels. This relationship was confirmed in multiple regression analysis where CAD extent was inversely and significantly associated with EET levels (P = 0.013), and with a biomarker of EET biosynthesis (P < 0.001), independent of clinical and demographic factors. Furthermore, quantitative enrichment analysis revealed that these associations were the most pronounced compared with other eicosanoid metabolism pathways. Collectively, these findings suggest that the presence of obstructive CAD is associated with lower EET metabolite levels secondary to suppressed EET biosynthesis. Novel strategies that promote the effects of EETs may have therapeutic promise for patients with obstructive CAD.

This work analyzed the process of lipid storage in fat body of larval Manduca sexta, focusing on the role of lipid transfer particle (LTP). Incubation of fat bodies with [3H]diacylglycerol-labeled lipophorin resulted in a significant accumulation of diacylglycerol (DAG) and triacylglycerol (TAG) in the tissue. Transfer of DAG to fat body and its storage as TAG was significantly inhibited (60%) by preincubating the tissue with anti-LTP antibody. Lipid transfer was restored to control values by adding LTP to fat body. Incubation of fat body with dual-labeled DAG lipophorin or its treatment with ammonium chloride showed that neither a membrane-bound lipoprotein lipase nor lipophorin endocytosis is a relevant pathway to transfer or to storage lipids into fat body, respectively. Treatment of fat body with suramin caused a 50% inhibition in [3H]DAG transfer from lipophorin. Treatment of [3H]DAG-labeled fat body with lipase significantly reduced the amount of [3H]DAG associated with the tissue, suggesting that the lipid is still on the external surface of the membrane.Whether this lipid represents irreversibly adsorbed lipophorin or a DAG lipase-sensitive pool is unknown. Nevertheless, these results indicate that the main pathway for DAG transfer from lipophorin to fat body is via LTP and receptor-mediated processes.

In this report we show the existence of a distinct pool of fat body diacylglycerol (DG) that can be distinguished from the bulk DG. This is a dynamic pool of DG that uses FA entering the fat body from the hemolymph, whereas the bulk DG uses the fatty acids stored in the fat body fat droplets. Using a dual labeling technique, it was possible to compare the effect of hormone-stimulated DG synthesis and secretion on the distribution of radiolabeled FA among the lipids of the dynamic pool (short-term radiolabeling), with the hormonal effect on the total complement of fat body lipids (long-term radiolabeling). We observed that, whereas DG represents 2% to 3% of the fat body lipid mass, about 20% of the short-term radiolabeled lipids are represented by DG. Stimulation of lipolysis produces a fast decrease in the fraction of short-term radiolabeled DG, whereas there is an increase in the mass of fat body DG. The subcellular distribution of bulk DG showed that its majority (62%) was in the fat cake whereas only 2.9% was in the cytosol. On lipolysis stimulation, the largest changes in specific activities of newly synthesized DG were detected in the cytosol and the fat cake, suggesting that newly synthesized DG localized in the lipid droplets and the cytosol is preferentially mobilized. —Arrese, E. L., J. L. Gazard, M. T. Flowers, J. L. Soulages, and M. A. Wells. Diacylglycerol transport in the insect fat body: evidence of involvement of lipid droplets and the cytosolic fraction.

α-Cyclodextrins are water-soluble cyclic hexamers of glucose units with hydrophobic cavities capable of solubilizing lipophiles. Incubating α-cyclodextrin with high density lipophorin from Manduca sexta or Bombyx mori resulted in a cloudy, turbid solution. Centrifugation separated a pale yellowish precipitate. Thin-layer chromatography analysis of the lipid extract of the precipitate showed that the major lipid was diacylglycerol, while KBr density gradient analysis of the supernatant demonstrated the presence of a lipid-depleted very high density lipophorin. Transfer of diacylglycerol from lipophorin to cyclodextrin was specific to α-cyclodextrin and was not observed with β- or γ-cyclodextrins. pH had no effect on diacylglycerol transfer to α-cyclodextrin. However, the transfer was strongly dependent on the concentration of α-cyclodextrin and temperature. Increasing the concentration of α-cyclodextrin in the incubation mixture was associated with the formation of increasingly higher density lipophorins. Thus, at 20, 30, and 40 mM α-cyclodextrin, the density of B. mori lipophorin increased from 1.107 g/ml to 1.123, 1.148, and 1.181 g/ml, respectively. At concentrations greater than 40 mM, α-cyclodextrin had no further effect on the density of lipophorin. α-Cyclodextrin removed at most 83–87% of the diacylglycerol present in lipophorin. Temperature played an important role in altering the amount of diacylglycerols transferred to α-cyclodextrin. At 30 mM α-cyclodextrin, the amount of diacylglycerol transferred at different temperatures was 50% at 4°C, 41% at 15°C, 20% at 28°C, and less than 3% at 37°C.We propose that diacylglycerol transfers to α-cyclodextrin via an aqueous diffusion pathway and that the driving force for the transfer is the formation of an insoluble α-cyclodextrin–diacylglycerol complex.

We have previously shown that stereospecific hydrolysis of stored triacylglycerol by a phosphorylatable triacylglycerol-lipase is the pathway for the adipokinetic hormone-stimulated synthesis of sn-1, 2-diacylglycerol in insect fat body. The current series of experiments were designed to determine whether cAMP and/or calcium are involved in the signal transduction pathway for adipokinetic hormone in the fat body. After adipokinetic hormone treatment, cAMP-dependent protein kinase activity in the fat body rapidly increased and reached a maximum after 20 min, suggesting that adipokinetic hormone causes an increase in cAMP. Forskolin (0.1 μm), an adenylate cyclase activator, induced up to a 97% increase in the secretion of diacylglycerol from the fat body. 8Br-cAMP (a membrane-permeable analog of cAMP) produced a 40% increase in the hemolymph diacylglycerol content. Treatment with cholera toxin, which also stimulates adenylate cyclase, induced up to a 145% increase in diacylglycerol production. Chelation of extracellular calcium produced up to 70% inhibition of the adipokinetic hormone-dependent mobilization of lipids. Calcium-mobilizing agents, ionomycin and thapsigargin, greatly stimulated DG production by up to 130%. Finally, adipokinetic hormone caused a rapid increase of calcium uptake into the fat body. Our findings indicate that the action of adipokinetic hormone in mobilizing lipids from the insect fat body involves both cAMP and calcium as intracellular messengers. —Arrese, E. L., M. T. Flowers, J. L. Gazard, and M. A. Wells. Calcium and cAMP are second messengers in the adipokinetic hormone-induced lipolysis of triacylglycerols in Manduca sexta fat body. J. Lipid Res. 1999. 40: 556–564.

Summary: Human pluripotent stem cell-derived neural progenitor cells (NPCs) are an essential tool for the study of brain development and developmental disorders such as autism. Here, we present a protocol to generate NPCs rapidly and reproducibly from human stem cells using dual-SMAD inhibition coupled with a brief pulse of mouse neurogenin-2 (Ngn2) overexpression. We detail the 48-h induction scheme deployed to produce these cells—termed stem cell-derived Ngn2-accelerated progenitor cells—followed by steps for expansion, purification, banking, and quality assessment.For complete details on the use and execution of this protocol, please refer to Wells et al.1 : Publisher’s note: Undertaking any experimental protocol requires adherence to local institutional guidelines for laboratory safety and ethics.

Objective: To estimate the diagnostic yield and efficacy of multiphase computed tomographic enterography (mpCTE) for suspected small bowel bleeding in routine clinical practice. Patients and Methods: All mpCTEs performed between January 1, 2006, and December 31, 2014, for suspected small bowel bleeding were included and classified by a gastroenterologist and an abdominal radiologist. The reference standard for a definitive diagnosis was balloon-assisted enteroscopic, angiographic, surgical, or pathologic results. Overall and lesion-specific diagnostic yield (DY), sensitivity, and positive predictive value were calculated. The relationship of mpCTE diagnosis and continued bleeding or iron supplementation was examined using logistic regression in patients with at least 1 year of follow-up. Results: We identified 1087 patients who had an initial mpCTE indication of small bowel bleeding. The overall DY was 31.6% (344 of 1087 patients; 95% CI, 29.0%-35.0%), higher for an indication of small bowel bleeding that was overt or occult with heme-positive stool vs occult with only iron-deficiency anemia (DY, 35.0% [170 of 486] and 35.3% [66 of 187] vs 26.1% [108 of 414]; P=.004 and P=.02, respectively). The highest sensitivity and positive predictive value were for small bowel masses (90.2% [55 of 61] and 98.2% [55 of 56], respectively). Higher risk of future bleeding and iron supplementation was seen with a negative result on mpCTE (odds ratio [OR], 1.91; 95% CI, 1.28-2.86), lack of surgical intervention (OR, 4.37; 95% CI, 2.31-8.29), or discrepant balloon-assisted enteroscopic findings (OR, 2.50; 95% CI, 1.03-6.09). Conclusion: Multiphase computed tomographic enterography has a higher rate of detection in patients with overt bleeding or heme-positive stool. The procedure provides actionable targets for further intervention and leads to substantially reduced rates of rebleeding in long-term follow-up.