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1 UK-37248 (dazoxiben), an orally active thromboxane synthetase inhibitor, was evaluated in a double-blind trial of patients with severe Raynaud's syndrome. 2 Twenty patients were enrolled in the study. Eleven of these patients received dazoxiben 400 mg day and nine received matching placebo capsules. Treatment was given for 6 weeks and the patients reviewed at 2 weekly intervals during the study. 3 Assessment of response was judged by clinical symptoms and hand temperature measurements. Haematological and haemostatic studies were also carried out. 4 Results show a significant clinical improvement in patients receiving dazoxiben for six weeks. Hand temperature measurements, and haematological and haemostatic blood tests remained unchanged, however, apart from the expected lowering in plasma thromboxane B2 levels. 5 The mechanism of action of the drug would appear not to be mediated through increased prostacyclin production and further studies are under way to determine how improvement has been obtained in these patients. [ABSTRACT FROM AUTHOR]

We describe a protein proximity inducing therapeutic modality called Regulated Induced Proximity Targeting Chimeras or RIPTACs: heterobifunctional small molecules that elicit a stable ternary complex between a target protein (TP) selectively expressed in tumor cells and a pan-expressed protein essential for cell survival. The resulting co-operative protein-protein interaction (PPI) abrogates the function of the essential protein, thus leading to death selectively in cells expressing the TP. This approach leverages differentially expressed intracellular proteins as novel cancer targets, with the advantage of not requiring the target to be a disease driver. In this chemical biology study, we design RIPTACs that incorporate a ligand against a model TP connected via a linker to effector ligands such as JQ1 (BRD4) or BI2536 (PLK1) or CDK inhibitors such as TMX3013 or dinaciclib. RIPTACs accumulate selectively in cells expressing the HaloTag-FKBP target, form co-operative intracellular ternary complexes, and induce an anti-proliferative response in target-expressing cells., Competing Interests: Declaration of interests C.M.C. is a shareholder and consultant to Halda Therapeutics, which supports research in his laboratory., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Lysosomal acid lipase (LAL) deficiency is an autosomal recessive disorder caused by LIPA gene mutations that disrupt LAL activity. We performed in vitro functional testing of 149 LIPA variants to increase the understanding of the variant effects on LAL deficiency and to improve disease prevalence estimates. Chosen variants had been reported in literature or population databases. Functional testing was done by plasmid transient transfection and LAL activity assessment. We assembled a set of 165 published LAL deficient patient genotypes to evaluate this assay's effectiveness to recapitulate genotype/phenotype relationships. Rapidly progressive LAL deficient patients showed negligible enzymatic activity (<1%), whereas patients with childhood/adult LAL deficiency typically have 1-7% average activity. We benchmarked six in silico variant effect prediction algorithms with these functional data. PolyPhen-2 was shown to have a superior area under the receiver operating curve performance. We used functional data along with Genome Aggregation Database (gnomAD) allele frequencies to estimate LAL deficiency birth prevalence, yielding a range of 3.45-5.97 cases per million births in European-ancestry populations. The low estimate only considers functionally assayed variants in gnomAD. The high estimate computes allele frequencies for variants absent in gnomAD, and uses in silico scores for unassayed variants. Prevalence estimates are lower than previously published, underscoring LAL deficiency's rarity., (© 2019 The Authors. Human Mutation Published by Wiley Periodicals, Inc.)

A high-throughput mass spectrometry assay to measure the catalytic activity of phosphatidylserine decarboxylase (PISD) is described. PISD converts phosphatidylserine to phosphatidylethanolamine during lipid synthesis. Traditional methods of measuring PISD activity are low throughput and unsuitable for the high-throughput screening of large compound libraries. The high-throughput mass spectrometry assay directly measures phosphatidylserine and phosphatidylethanolamine using the RapidFiretrade mark platform at a rate of 1 sample every 7.5 s. The assay is robust, with an average Z' value of 0.79 from a screen of 9920 compounds. Of 60 compounds selected for confirmation, 54 are active in dose-response studies. The application of high-throughput mass spectrometry permitted a high-quality screen to be performed for an otherwise intractable target.

An enhanced method to measure the concentration of individual naturally occurring free amino acids in solution is described. This relatively simple but robust method combines two previously reported procedures: the use of scintillation proximity assay (SPA) technology to measure aminoacyl-tRNA synthetase (aaRS) activity and the use of aaRS activity to measure amino acid concentration using the enzymatic isotope dilution technique. The format described is called an aaRS competitive scintillation proximity assay (cSPA). This cSPA takes advantage of competition between a fixed concentration of radiolabeled amino acid and an unknown concentration of the same nonradiolabeled amino acid for its cognate tRNA catalyzed by the aaRS specific for that amino acid. Under equilibrium conditions, in the case of limiting tRNA, the rate of the enzyme-catalyzed reaction relative to substrate concentration becomes irrelevant and the enzymatic isotopic dilution technique becomes the simple isotopic dilution technique. Due to the exquisite specificity of the reaction, a crude mixture of tRNAs and aaRSs can be used to detect the concentration of a particular amino acid without interference from noncognate amino acids. When used to monitor aminopeptidase M activity, this assay produced similar results in time course and inhibition experiments as compared with a traditional fluorescent assay. High-throughput compatibility was demonstrated by screening 12,000 compounds against aminopeptidase M in 384-well microtiter plates with Z factors ranging from 0.53 to 0.70. This competitive assay can be used as a general method to detect amino acids at concentrations less than 100 nM and to monitor enzyme activity in biological samples, and it is amenable to high-throughput screening.

The objective was to explore variation in cardiovascular risk profiles within the Scottish workforce over different regions of Scotland by a planned review of survey data of workplaces throughout Scotland, surveyed between December 1991 and March 1996. The subjects sampled were 19,400 men and women aged between 18 and 70, who were in work and apparently healthy at the time of screening. The results showed that the regions of Scotland may be distinguished through particular risk factors and also by using a single summary score (the SHARP risk score). Overall the Perth and Kinross region tops the league for cardiovascular risk (with the main contributing factors being smoking and high blood pressure); regions of least risk are Inverness-shire and Edinburgh. There are statistically significant differences to be discerned in the regional distribution of cardiovascular risk within the working population of Scotland.

Summary analyses of screening data were used to ascertain the cardiovascular risk profile in a sample of health care workers in Scotland. A sample of NHS staff (298 women and 78 men) were screened during visits to Perth Royal Infirmary (PRI) in 1996 and 1997. Comparisons were made within subsets and with previous screening studies. Health care workers have been a neglected component of the workforce for receiving education about risk factors. The high prevalence of smokers found in this sample should be a cause for concern.

The need for a mobile screening unit to travel throughout Scotland to measure and modify cardiovascular risk factors in the apparently healthy working population was fulfilled by the conversion of a double-decker bus. The aim of the project was to assess the incidence of risk factors in healthy individuals and to modify their risk factors by individual counselling. Many unforeseen practical problems were encountered and overcome during the planning stage and during the project. The team of specially trained staff spent three and a half years screening more than 20,000 people throughout Scotland. This project provides a model for other screening projects involving a multicentre/scattered cohort.

The precise role of antiplatelet therapy in secondary stroke prevention remains a matter of some debate. Although specific antiplatelet agents (notably aspirin, ticlopidine, dipyridamole, and clopidogrel) have been shown to be active in the prevention of secondary stroke, questions remain about the effective dose of these agents and their potential efficacy in combined therapeutic regimens. In addition, haematological and gastrointestinal side-effects of antiplatelet agents remain a significant clinical concern for patients and prescribing physicians. This review article examines research on both monotherapy and combination antiplatelet therapy for secondary stroke prevention, with an emphasis on lessons learned about dosage schedules, treatment protocols, and side-effect profiles.

The safety and pharmacodynamic compatibility of clopidogrel with medications commonly used in patients with atherosclerosis, such as, a beta-adrenergic receptor antagonist (atenolol) and a calcium uptake inhibitor (nifedipine) were assessed. Atenolol and nifedipine interactions with clopidogrel were studied in patients with peripheral arterial obstructive disease taking a well-established regimen of nifedipine (N group of 6 patients) and in patients with coronary artery disease taking a well-established regimen of either atenolol (A group of 8 patients) or of atenolol and nifedipine (AN group of 8 patients). The study was conducted as a double-blind, randomized, crossover comparison of clopidogrel, 75 mg once daily, and placebo treatment for 7 days, with a 14-day washout between treatments. Pharmacodynamic interactions between atenolol and nifedipine, either alone or in combination, and clopidogrel were assessed primarily on the clinical control of angina or hypertension and, secondarily, by comparing the extent of inhibition of ADP (5 microM)-induced platelet aggregation achieved between the 3 groups. The mean number of anginal episodes per patient during the placebo week was 1.50, 9.0 and 11.5 in the A, N and AN groups, respectively; during the week of clopidogrel treatment, it was 1.39, 7.3 and 9.0, respectively, indicating no change in occurrence. Likewise, review of the use of nitrates (long or short acting) did not suggest any major change in usage during any period of the study. ECGs did not change between the three recording times (at screening and at the end of each treatment period). Vital signs were also unchanged throughout. Percent inhibition of platelet aggregation on day 7 was 31% in the N group, 39% in the A group, 28% in the AN group, and 33% overall. In conclusion, the coadministration of clopidogrel did not interfere with the clinical control of hypertension or angina established with atenolol or nifedipine, or both. Clopidogrel retained its full antiplatelet effect, and there were no safety problems caused by the coadministration.

Patients who had survived a stroke or transient ischaemic attacks (TIA) were admitted to a trial of low-dose aspirin (50 mg) alone, sustained release dipyridamole (400 mg/day) alone, or a combination of the two agents, and results compared with a placebo over 24 months. This low-dose aspirin regimen produced in pairwise comparisons a significant risk reduction of 18% for stroke, 13% for stroke and/or death but no reduction in all cause mortality. The sustained release dipyridamole produced a significant risk reduction of 16% for stroke, 15% for stroke and/or death but no significant reduction of mortality. In combination, aspirin and dipyridamole produced a risk reduction of 37% in stroke, 24% in stroke and/or death, and no reduction in mortality. Similar findings were found in TIA, which was a secondary endpoint. These results are highly significant in comparison with placebo. As expected, there were enhanced reports of alimentary side-effects in the aspirin groups and also enhanced bleeding. Dipyridamole was associated with a slight increase in headache, which resolved in most patients if therapy was continued. The conclusions are that 50 mg/day of aspirin alone or 400 mg/day of sustained release dipyridamole alone are equally effective in stroke and TIA prevention. When used in combination the effects were additive and were significantly more effective than the single agents.

In an increasing number of recent major clinical trials, independent safety committees or safety monitors have been involved. Their role and function is not yet defined and continues to evolve. The aim of this paper is to discuss the role and tasks of safety committees as a result of our collective experience as members of three safety committees of studies evaluating antithrombotic prophylaxis against postoperative deep vein thrombosis. We believe that the type of pharmacological intervention used is of less importance than the general experiences gained, which can be extrapolated to other studies and should stimulate a more general debate.