Runx1 dose-dependently regulates endochondral ossification during skeletal development and fracture healing

Runx1 is expressed in skeletal elements, but its role in fracture repair has not been analyzed. We created mice with a hypomorphic Runx1 allele (Runx1(L148A) ) and generated Runx1(L148A/-) mice in which >50% of Runx1 activity was abrogated. Runx1(L148A/-) mice were viable but runted. Their growth plates had extended proliferating and hypertrophic zones, and the percentages of Sox9-, Runx2-, and Runx3-positive cells were decreased. Femoral fracture experiments revealed delayed cartilaginous callus formation, and the expression of chondrogenic markers was decreased. Conditional ablation of Runx1 in the mesenchymal progenitor cells of the limb with Prx1-Cre conferred no obvious limb phenotype; however, cartilaginous callus formation was delayed following fracture. Embryonic limb bud-derived mesenchymal cells showed delayed chondrogenesis when the Runx1 allele was deleted ex vivo with adenoviral-expressed Cre. Collectively, our data suggest that Runx1 is required for commitment and differentiation of chondroprogenitor cells into the chondrogenic lineage.     

Stingray injury to the webspace of the foot

Stingrays are cartilaginous fish that are related to sharks. They are one of the largest groups of venomous marine animals. Stingrays account for 750 to 2000 injuries annually. They are generally passive, reclusive creatures that only sting in self-defense. Most injuries caused by these animals are nonfatal. A stingray possesses between 1 and 4 venomous stings, which are located along the caudal spine. If a stingray injury is sustained, parts of the spine may be left in the lacerations, which prolongs exposure to venom and increases the risk of subsequent wound infection. Stingray venom is unique in its enzymatic composition and results in distinct soft tissue injury patterns. Typically, a pattern of acute inflammation occurs, with a predominantly lymphoid cellular infiltrate followed by necrosis. The environment in which stingray injuries occur presents unique bacterial flora, and subsequent wound infections require careful antibiotic selection.This article describes a case of a healthy 31-year-old woman who sustained a stingray injury to the webspace of the foot while in Costa Rica. Initial basic first aid measures were applied. However, the wound subsequently became infected, and formal irrigation and debridement were performed. The initial wound cultures grew Staphylococcus viridans. Two months postoperatively, the incision was well healed, and the patient was pain free and returned to work.     

Manufacturing‐dependent change in biological activity of the TLR4 agonist GSK1795091 and implications for lipid A analog development

A phase I trial ({"type":"clinical-trial","attrs":{"text":"NCT03447314","term_id":"NCT03447314"}}NCT03447314; 204686) evaluated the safety and efficacy of GSK1795091, a Toll‐like receptor 4 (TLR4) agonist, in combination with immunotherapy (GSK3174998 [anti‐OX40 monoclonal antibody], GSK3359609 [anti‐ICOS monoclonal antibody], or pembrolizumab) in patients with solid tumors. The primary endpoint was safety; other endpoints included efficacy, pharmacokinetics, and pharmacodynamics (PD). Manufacturing of GSK1795091 formulation was modified during the trial to streamline production and administration, resulting in reduced PD (cytokine) activity. Fifty‐four patients received GSK1795091 with a combination partner; 32 received only the modified GSK1795091 formulation, 15 received only the original formulation, and seven switched mid‐study from the original to the modified formulation. Despite the modified formulation demonstrating higher systemic GSK1795091 exposure compared with the original formulation, the transient, dose‐dependent elevations in cytokine and chemokine concentrations were no longer observed (e.g., IP‐10, IL10, IL1‐RA). Most patients (51/54; 94%) experienced ≥1 treatment‐emergent adverse event (TEAE) during the study. Safety profiles were similar between formulations, but a higher incidence of TEAEs associated with immune responses (chills, fatigue, pyrexia, nausea, and vomiting) were observed with the original formulation. No conclusions can be made regarding GSK1795091 anti‐tumor activity due to the limited data collected. Manufacturing changes were hypothesized to have caused the change in biological activity in this study. Structural characterization revealed GSK1795091 aggregate size in the modified formulation to be twice that in the original formulation, suggesting a negative correlation between GSK1795091 aggregate size and PD activity. This may have important clinical implications for future development of structurally similar compounds.

Study Highlights

• WHAT IS THE CURRENT KNOWLEDGE ON THE TOPIC?

Toll‐like receptor 4 (TLR4) agonists, such as lipopolysaccharide (LPS) and lipid A analogs, have demonstrated anti‐cancer effects in patients. Previous studies offer conflicting evidence on the active form (monomeric vs. aggregates) of LPS/lipid A analogs and suggest that different forms can stimulate different immune pathways.

• WHAT QUESTION DID THIS STUDY ADDRESS?

This phase I study investigated the safety, pharmacokinetics (PK), and pharmacodynamics (PD) of GSK1795091 with one of three immunotherapies in patients with solid tumors. In addition, the study addressed the effects of a manufacturing change on the biological activity of GSK1795091.

• WHAT DOES THIS STUDY ADD TO OUR KNOWLEDGE?

This study enables a better understanding of the impact of the manufacturing process on drug aggregate morphology and activity. The formulation change led to the formation of particle aggregates with globular morphology, suggesting the initial dissolution of GSK1795091 in ethanol, instead of initial dissolution using sonication, was the likely contributor to the lowered biological activity of GSK1795091. This could have implications for the development of other lipid A analogs and TLR agonists.

• HOW MIGHT THIS CHANGE CLINICAL PHARMACOLOGY OR TRANSLATIONAL SCIENCE?

Following manufacturing changes of LPS/other lipid A analogs and chemically manufactured active pharmaceutical ingredients that are prone to structural organization in solution, it is recommended to perform in vitro PD assessments to understand the impact on its biological activity prior to clinical assessment. PK and PD evaluations should be prioritized to ensure no clinically meaningful changes related to the manufacturing occur.     

Relational Potential versus the Parent‐Child Relationship

In an article in this issue of the Hastings Center Report, Aaron Wightman and his coauthors attempt to address health care providers’ moral distress about acceding to parents’ requests to provide life‐sustaining medical treatment to children who have profound cognitive disabilities. They propose combining John Arras's relational potential standard and care ethics, and they argue that the capacity for caring relationships can provide an independent moral justification for honoring such requests. This combination is, however, unstable. Wightman et al.'s language of potential and capacity opens the possibility of substantial misinterpretation. They rely on epistemological and prognostic uncertainty to argue that reciprocity and participation may be present in the parent‐child relationship even when the child's engagement cannot be observed. The terminology suggests that these are characteristics that can be gained or lost rather than characteristics of being born within certain social practices. In contrast, Eva Feder Kittay illuminates family membership as an important social relation. Her articulation of the independent moral value of parenting stands on its own without being conjoined to Arras's position.     

Pneumothorax and other lung diseases: effect of altered resolution and edge enhancement on diagnosis with digitized radiographs

Prior studies have shown that pneumothorax is one of the more difficult entities to diagnose with digitized radiography. This study was designed to test whether increasing resolution from 1.25 to 2.5 line pairs per millimeter (lp/mm) and image processing (edge enhancement from unsharp masking) would increase accuracy and confidence in the diagnosis of pneumothorax, as well as normal cases and other forms of lung disease. Conventional radiographs were digitized with use of a laser reader and then reformatted as film hard copy. Eleven observers read 35 cases reformatted in three different ways (1.25 lp/mm, 2.5 lp/mm, 1.25 lp/mm unsharp mask). The images with finer resolution (2.5 lp/mm) and unsharp mask images were superior to those with coarser resolution (1.25 lp/mm) for the diagnosis of pneumothorax. There was no difference in diagnostic accuracy for normal patients. For abnormalities other than pneumothorax, the unsharp mask images were significantly worse. Confidence in the diagnosis of pneumothorax and other abnormalities was highest with the finest resolution (2.5 lp/mm).     

Bile duct stones: percutaneous transhepatic removal

Percutaneous transhepatic intervention for transduodenal removal of biliary stones was performed 38 times in 34 patients with obstructive jaundice, biliary colic, and cholangitis. The technique entailed the percutaneous transhepatic placement of a modified Dormia basket in the common duct with the flexible tip in the duodenum. The stones were passed into the duodenum and were crushed, or were crushed in the common duct and passed as fragments into the duodenum. In addition to the snare procedure, monooctanoin was used 18 times to dissolve remaining fragments of stone and sludge that could not be snared and passed into the duodenum. The average time for completion of the procedure was 10 days. There were no deaths from the procedure. The complication rate was 21%--probably no greater than would occur with surgery in a similar patient population. The procedure can be performed when endoscopic retrograde cholangiopancreatography and sphincterotomy with stone removal is technically impossible or refused, and in patients who have previously undergone choledochojejunostomy.     

赛拉嗪对麻醉大鼠海马CA1区乙酰胆碱含量的影响

应用乙酰胆碱选择性微电极技术,观察到小剂量赛拉嗪(2.0和6.0mg·kg^-1)可显著增加大鼠海马CA1区ACh的含量,而大剂量赛拉嗪(10.0mg·kg^-1)及咪唑克生(0.6mg·kg^-1)则作用相反。咪唑克生虽可明显拮抗赛拉嗪的作用,但海马CA₁区ACh的含量仍显著低于正常水平。在去兰斑核的大鼠上,赛拉嗪(2.0和6.0mg·kg^-1)及咪唑克生(0.6mg·kg^-1)分别对海马CA₁区ACh的含量具有减少和增加作用,且咪唑克生拮抗赛拉嗪的作用后,海马CA₁区ACh的含量基本恢复至正常水平。结果提示,赛拉嗪对麻醉大鼠海马CA₁区ACh含量呈双相性影响,咪唑可生虽能显著拮抗赛拉嗪的作用,但海马CA₁区ACh的含量仍明显低于正常水平,可能分别与赛拉嗪和咪唑克生降低或提高中枢NE能系统的功能有关。     

A PIL for every ill? Patient information leaflets (PILs): a review of past, present and future use

This article reviews the usefulness and importance of written information, specifically leaflets, being given to patients. Evidence suggesting how both patient and doctor may benefit from the giving of written information is reviewed. Identification of good practice relating to the content and readability of leaflets is discussed. An argument is put forward that the giving of written information is an under-utilized resource in contributing to improving patient outcomes but that this may be changing with the increasing use of patient leaflet databases. The advantages and disadvantages of computer- generated patient leaflets are discussed and desirable further areas of research on computer-generated leaflets are proposed.