Synthesis and Functional Evaluation of Synthetic Cannabinoid Receptor Agonists Related to ADB-HEXINACA

ADB-HEXINACA has been recently reported as a synthetic cannabinoid receptor agonist (SCRA), one of the largest classes of new psychoactive substances (NPSs). This compound marks the entry of the n-hexyl tail group into the SCRA landscape, which has continued in the market with recent, newly detected SCRAs. As such, a proactive characterization campaign was undertaken, including the synthesis, characterization, and pharmacological evaluation of ADB-HEXINACA and a library of 41 closely related analogues. Two in vitro functional assays were employed to assess activity at CB1 and CB2 cannabinoid receptors, measuring Gβγ-coupled agonism through a fluorescence-based membrane potential assay (MPA) and β-arrestin 2 (βarr2) recruitment via a live cell-based nanoluciferase complementation reporter assay. ADB-HEXINACA was a potent and efficacious CB1 agonist (CB1 MPA pEC50 = 7.87 ± 0.12 M; Emax = 124 ± 5%; βarr2 pEC50 = 8.27 ± 0.14 M; Emax = 793 ± 42.5), as were most compounds assessed. Isolation of the heterocyclic core and alkyl tails allowed for the comprehensive characterization of structure-activity relationships in this compound class, which were rationalized in silico via induced fit docking experiments. Overall, most compounds assessed are possibly emerging NPSs.

Synthesis and pharmacological evaluation of newly detected synthetic cannabinoid receptor agonists AB-4CN-BUTICA, MMB-4CN-BUTINACA, MDMB-4F-BUTICA, MDMB-4F-BUTINACA and their analogs

Synthetic cannabinoid receptor agonists (SCRAs) continue to make up a significant portion new psychoactive substances (NPS) detected and seized worldwide. Due to their often potent activation of central cannabinoid receptors in vivo, use of SCRAs can result in severe intoxication, in addition to other adverse health effects. Recent detections of AB-4CN-BUTICA, MMB-4CN-BUTINACA, MDMB-4F-BUTICA and MDMB-4F-BUTINACA mark a continuation in the appearance of SCRAs bearing novel tail substituents. The proactive characterization campaign described here has facilitated the detection of several new SCRAs in toxicological case work. Here we detail the synthesis, characterization, and pharmacological evaluation of recently detected SCRAs, as well as a systematic library of 32 compounds bearing head, tail, and core group combinations likely to appear in future. In vitro radioligand binding assays revealed most compounds showed moderate to high affinity at both CB₁ (pK _i = < 5 to 8.89 ± 0.09 M) and CB₂ (pK _i = 5.49 ± 0.03 to 9.92 ± 0.09 M) receptors. In vitro functional evaluation using a fluorescence-based membrane potential assay showed that most compounds were sub-micromolar to sub-nanomolar agonists at CB₁ (pEC₅₀ = < 5 to 9.48 ± 0.14 M) and CB₂ (pEC₅₀ = 5.92 ± 0.16 to 8.64 ± 0.15 M) receptors. An in silico receptor-ligand docking approach was utilized to rationalize binding trends for CB₂ with respect to the tail substituent, and indicated that rigidity in this region (i.e., 4-cyanobutyl) was detrimental to affinity.

Concentrations and health effects of potash dust

In an investigation of the relationship between atmospheric dust levels and worker health, the respiratory dust exposures of employees at two Saskatchewan potash mines were examined following atmospheric measurements. Some, notably those of the mining crew and the screening operators, were above the Threshold Limit Value 8-hour Time Weighted Average (TLV-TWA) for total nuisance particulates specified by the American Conference of Governmental Industrial Hygienists (ACGIH). Respiratory symptoms were recorded and forced expiratory lung function tests were done among 850 volunteers drawn from an eligible work force of 931. The results were compared between low and higher exposure groups after allowing for personal factors such as age and smoking habits. Symptoms of Grade I chronic phlegm production and mild shortness of breath and chronic cough were more common in the higher exposure groups, but episodes of chest illness were not. Severe respiratory symptoms were rare. There were no statistically significant differences in the proportions performing lung function tests below predicted values.

Carbon assimilation by different developmental stages of Laminaria saccharina

Various stages of the life cycle of the marine brown alga Laminaria saccharina (L.) Lamour. (Laminariales, Phaeophyta) including male and female gametophytes, female gametes, zygotes and young sporophytes of different age were investigated for their potentials of carbon dioxide ((14)CO2) fixation. Rates of photosynthesis attain the same order of magnitude in all stages. Photosynthetic (14)CO2-fixation is accompanied by a substantial light independent carbon assimilation. This is confirmed by rate determinations of the equivalent carboxylating enzymes present in the plants, ribulose-1,5-bisphosphate carboxylase (EC 4.1.1.39) and phosphoenolpyruvate carboxokinase (EC 4.1.1.32) as well as by chromatographic analyses of the appropriate [(14)C]-assimilate patterns.

Carotid-cavernous sinus fistula treated by intravascular occlusion with a balloon catheter. Report of two cases

✓ The author reports two cases of fistula of the carotid-cavernous sinus successfully treated by intraluminal occlusion with a balloon catheter. The fistulas have remained obliterated for 3 years, and no reactions have occurred in either case from the indwelling intra-arterial catheter.

Sudden loss of vision following alcohol block of the infraorbital nerve. Case report

✓ The unusual complication of sudden ipsilateral loss of vision following alcohol block of the infraorbital nerve for tic douloureux is described and the possible physiopathology discussed. The author believes that spasm of the central retinal artery was the cause and that repeated injections may have been a predisposing factor. Review of other cases reported shows that the loss of vision has been attributed to embolization of injected agents via collateral blood vessels.

Use of centrifuge in the treatment of an intraventricular metallic foreign body. Technical note

✓ A bullet fragment within the ventricular system was immobilized by use of centrifugation in a 5°-of-freedom-of-motion simulator at 4 to 6 G's. Transient cardiovascular changes occurred, but there were no ill effects clinically. The bullet fragment was immobilized within the ependyma of the left lateral ventricle and has remained in a fixed position during a 22-month follow-up period. A brief review of the treatment of intraventricular foreign bodies is included.