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We present the case of a patient with headache who, on computed tomography, was found to have subarachnoid hemorrhage. Angiography revealed bilateral persistent trigeminal arteries, anterior communicating artery and left pericallosal artery aneurysms, and an absent left vertebral artery. An anomalous right subclavian artery, originating at a common trunk with the left subclavian artery, was also present. To our knowledge, this is the fifth case of bilateral persistent trigeminal arteries and the sixth case of bilateral persistent carotid-basilar anastomosis of any type reported in the literature. A mechanism for the pathogenesis of multiple cerebrovascular anomalies is briefly discussed. [ABSTRACT FROM AUTHOR]

Objective In September 2006, a Panamanian physician reported an unusual number of patients with unexplained acute renal failure frequently accompanied by severe neurological dysfunction. Twelve (57%) of 21 patients had died of the illness. This paper describes the investigation into the cause of the illness and the source of the outbreak. Methods Case-control and laboratory investigations were implemented. Case patients (with acute renal failure of unknown etiology and serum creatinine ³ 2 mg/dl) were individually matched to hospitalized controls for age (± 5 years), sex and admission date (£ 2 days before the case patient). Questionnaire and biological data were collected. The main outcome measure was the odds of ingesting prescription cough syrup in cases and controls. Findings Forty-two case patients and 140 control patients participated. The median age of cases was 68 years (range: 25DS91 years); 64% were male. After controlling for pre-existing hypertension and renal disease and the use of angiotensin-converting enzyme inhibitors, a significant association was found between ingestion of prescription cough syrup and illness onset (adjusted odds ratio: 31.0, 95% confidence interval: 6.93DS138). Laboratory analyses confirmed the presence of diethylene glycol (DEG) in biological samples from case patients, 8% DEG contamination in cough syrup samples and 22% contamination in the glycerin used to prepare the cough syrup. Conclusion The source of the outbreak was DEG-contaminated cough syrup. This investigation led to the recall of approximately 60 000 bottles of contaminated cough syrup, widespread screening of potentially exposed consumers and treatment of over 100 affected patients. Copyright © 2008 World Health Organization [ABSTRACT FROM AUTHOR]

Our understanding of the cell behaviours and cytoskeletal requirements of axon formation is largely derived from in vitro models but how these relate to axon formation in vivo is not clear. In vitro, neurons progress through a well-defined multineurite stage to form an axon and both actin and microtubules cooperate to drive the first steps in neurite and axon morphogenesis. However, these steps are not recapitulated in vivo, and it is not clear whether the underlying cell biological mechanisms may differ also. Here, we investigate the mechanisms that regulate axon formation in embryonic zebrafish spinal neurons in vivo. We find microtubule organising centres are located distant from the site of axon initiation, and microtubule plus-ends are not enriched in the axon during axon initiation. Focal F-actin accumulation precedes axon formation, and we find that nocodazole-treated neurons with no detectable microtubules are still able to form nascent axonal protrusions that are approximately 10-μm long, dilated and relatively long-lived. We suggest spinal axon formation in vivo is fundamentally different from axon formation in in vitro models., (© 2022 The Authors. Published under the terms of the CC BY 4.0 license.)

Proprotein convertase subtilisin-like/kexin type 9 (PCSK9) is a key regulator of plasma LDL-cholesterol (LDL-C) and a clinically validated target for the treatment of hypercholesterolemia and coronary artery disease. Starting from second-generation lead structures such as 2 , we were able to refine these structures to obtain extremely potent bi- and tricyclic PCSK9 inhibitor peptides. Optimized molecules such as 44 demonstrated sufficient oral bioavailability to maintain therapeutic levels in rats and cynomolgus monkeys after dosing with an enabled formulation. We demonstrated target engagement and LDL lowering in cynomolgus monkeys essentially identical to those observed with the clinically approved, parenterally dosed antibodies. These molecules represent the first report of highly potent and orally bioavailable macrocyclic peptide PCSK9 inhibitors with overall profiles favorable for potential development as once-daily oral lipid-lowering agents. In this manuscript, we detail the design criteria and multiparameter optimization of this novel series of PCSK9 inhibitors.

Proprotein convertase subtilisin-like/kexin type 9 (PCSK9) is a key regulator of plasma LDL-cholesterol (LDL-C) and a clinically validated target for the treatment of hypercholesterolemia and coronary artery disease. In this paper, we describe a series of novel cyclic peptides derived from an mRNA display screen which inhibit the protein-protein interaction between PCSK9 and LDLR. Using a structure-based drug design approach, we were able to modify our original screening lead 2 to optimize the potency and metabolic stability and minimize the molecular weight to provide novel bicyclic next-generation PCSK9 inhibitor peptides such as 78 . These next-generation peptides serve as a critical foundation for continued exploration of potential oral, once-a-day PCSK9 therapeutics for the treatment of cardiovascular disease.

Purpose: In this study we evaluated the utility of in-vitro screening tools for predicting the in-vivo behavior of six cyclic peptides with different solubility and permeability properties (BCS class II and III), intended for oral delivery in presence of permeation enhancer Labrasol., Methods: An in vitro flux assay was used to assess peptide permeation across a biomimetic, lipid-based membrane and in vivo studies in rats were used to determine oral peptide bioavailability in the presence of Labrasol., Results: The in vitro flux was significantly increased for BCS class III peptides, while it significantly decreased or remained unchanged for BCS class II peptides with increasing Labrasol concentrations. The different flux responses were attributed to the combination of reduced effective free peptide concentration and increased membrane permeability in the presence of Labrasol. In vivo studies in male Wistar-Hans rats indicated improved oral bioavailability at different extents for all peptides in presence of Labrasol. On comparing the in vitro and in vivo data, a potential direct correlation for BCS class III peptides was seen but not for BCS class II peptides, due to lower free concentrations of peptides in this class., Conclusion: This study assessed the utility of in vitro screening tools for selecting peptides and permeation excipients early in drug product development. Graphical Abstract Graphical Abstract and Figure 1 contains small text.Graphical Abstract text is made larger. The Figure 1 text cannot be made larger.

We report herein the design and synthesis of a series of orally active, liver-targeted hypoxia-inducible factor prolyl hydroxylase (HIF-PHD) inhibitors for the treatment of anemia. In order to mitigate the concerns for potential systemic side effects, we pursued liver-targeted HIF-PHD inhibitors relying on uptake via organic anion transporting polypeptides (OATPs). Starting from a systemic HIF-PHD inhibitor ( 1 ), medicinal chemistry efforts directed toward reducing permeability and, at the same time, maintaining oral absorption led to the synthesis of an array of structurally diverse hydroxypyridone analogues. Compound 28a was chosen for further profiling, because of its excellent in vitro profile and liver selectivity. This compound significantly increased hemoglobin levels in rats, following chronic QD oral administration, and displayed selectivity over systemic effects., Competing Interests: The authors declare no competing financial interest.

An African American teenage boy during an acute sickle cell crisis spontaneously developed acute bifrontal epidural haematomas (EDHs) in addition to disseminated intravascular coagulation (DIC). The successfully evacuated EDH reaccumulated postoperatively. After multiple transfusions, the patient underwent repeat surgery. Subsequent maximal medical therapy was unable to significantly improve the patient's neurological status, and due to family wishes, care was withdrawn. EDH are the most common emergent neurosurgical complication of sickle cell disease (SCD). Twenty-two such cases have been previously reported. We present one further complicated by DIC leading to reaccumulation of the patient's EDH. An understanding of the mechanisms of EDH formation in SCD and their associated radiological findings could help clinicians identify when a patient is at high risk of EDH formation and thus offer the potential for early intervention prior to the development of an emergency., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2018. No commercial re-use. See rights and permissions. Published by BMJ.)

Advances in endovascular embolization have improved morbidity and mortality among patients with vein of Galen malformations (VoGMs). The patient presented at 3 months of age with increased head circumference and a bruit over his anterior fontanelle. Diagnostic cerebral angiography confirmed the presence of a large mural-type VoGM. The decision was made to undergo a staged arterial embolization at 4 years of age after developing worsening right-sided hemiparesis. An attempt was made to occlude the posterior choroidal feeding vessel with a large 25 mm × 50 cm coil, followed by a 6 mm × 20 cm coil; however, the high flow of the lesion displaced both coils into the wall of the aneurysmal venous sac. Interval magnetic resonance imaging and angiography revealed partial occlusion of the VoGM at 7 months and complete thrombosis at 24 months post procedure, precluding a need for additional coiling. This case illustrates that a minimal change in intramural flow dynamics of VoGMs could lead to progressive thrombosis., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Parenteral delivery remains a compelling drug delivery route for both large- and small-molecule drugs and can bypass issues encountered with oral absorption. For injectable drug products, there is a strong patient preference for subcutaneous administration due to its convenience over intravenous infusion. However, in subcutaneous injection, in contrast to intravenous administration, the formulation is in contact with an extracellular matrix environment that behaves more like a gel than a fluid. This can impact the expected performance of a formulation. Since typical bulk fluid dissolution studies do not accurately simulate the subcutaneous environment, improved in vitro models to help better predict the behavior of the formulation are critical. Herein, we detail the development of a new model system consisting of a more physiologically relevant gel phase to simulate the rate of drug release and diffusion from a subcutaneous injection site using agarose hydrogels as a tissue mimic. This is coupled with continuous real-time data collection to accurately monitor drug diffusion. We show how this in vitro model can be used as an in vivo performance differentiator for different formulations of both large and small molecules. Thus, this model system can be used to improve optimization and understanding of new parenteral drug formulations in a rapid and convenient manner.