Identification of regulators of polyploidization presents therapeutic targets for treatment of AMKL.

The mechanism by which cells decide to skip mitosis to become polyploid is largely undefined. Here we used a high-content image-based screen to identify small-molecule probes that induce polyploidization of megakaryocytic leukemia cells and serve as perturbagens to help understand this process. Our study implicates five networks of kinases that regulate the switch to polyploidy. Moreover, we find that dimethylfasudil (diMF, H-1152P) selectively increased polyploidization, mature cell-surface marker expression, and apoptosis of malignant megakaryocytes. An integrated target identification approach employing proteomic and shRNA screening revealed that a major target of diMF is Aurora kinase A (AURKA). We further find that MLN8237 (Alisertib), a selective inhibitor of AURKA, induced polyploidization and expression of mature megakaryocyte markers in acute megakaryocytic leukemia (AMKL) blasts and displayed potent anti-AMKL activity in vivo. Our findings provide a rationale to support clinical trials of MLN8237 and other inducers of polyploidization and differentiation in AMKL.

Identification of host-targeted small molecules that restrict intracellular Mycobacterium tuberculosis growth.

Mycobacterium tuberculosis remains a significant threat to global health. Macrophages are the host cell for M. tuberculosis infection, and although bacteria are able to replicate intracellularly under certain conditions, it is also clear that macrophages are capable of killing M. tuberculosis if appropriately activated. The outcome of infection is determined at least in part by the host-pathogen interaction within the macrophage; however, we lack a complete understanding of which host pathways are critical for bacterial survival and replication. To add to our understanding of the molecular processes involved in intracellular infection, we performed a chemical screen using a high-content microscopic assay to identify small molecules that restrict mycobacterial growth in macrophages by targeting host functions and pathways. The identified host-targeted inhibitors restrict bacterial growth exclusively in the context of macrophage infection and predominantly fall into five categories: G-protein coupled receptor modulators, ion channel inhibitors, membrane transport proteins, anti-inflammatories, and kinase modulators. We found that fluoxetine, a selective serotonin reuptake inhibitor, enhances secretion of pro-inflammatory cytokine TNF-α and induces autophagy in infected macrophages, and gefitinib, an inhibitor of the Epidermal Growth Factor Receptor (EGFR), also activates autophagy and restricts growth. We demonstrate that during infection signaling through EGFR activates a p38 MAPK signaling pathway that prevents macrophages from effectively responding to infection. Inhibition of this pathway using gefitinib during in vivo infection reduces growth of M. tuberculosis in the lungs of infected mice. Our results support the concept that screening for inhibitors using intracellular models results in the identification of tool compounds for probing pathways during in vivo infection and may also result in the identification of new anti-tuberculosis agents that work by modulating host pathways. Given the existing experience with some of our identified compounds for other therapeutic indications, further clinically-directed study of these compounds is merited.

Implementation of a mailed faecal immunochemical test programme for colorectal cancer screening among Veterans.

BACKGROUND: Screening for colorectal cancer (CRC) with faecal immunochemical test (FIT) is effective at reducing CRC mortality. Unfortunately, the COVID-19 pandemic has been associated with deferred care, especially screening for CRC. AIM: We sought to develop a mailed FIT programme (MFP) to increase CRC screening and make recommendations for adoption across the Veterans Health Administration (VHA) and for other large healthcare systems. SETTING: 2 regional VA medical centres in California and Washington state. PARTICIPANTS: 5667 average risk veterans aged 50-75 overdue or due within 90 days for CRC screening. PROGRAMME DESCRIPTION: A multidisciplinary implementation team collaborated to mail an FIT kit to eligible veterans. Both sites mailed a primer postcard, and one site added an automated reminder call. PROGRAMME EVALUATION: We monitored FIT return and positivity rate, as well as impact of the programme on clinical staff. 34% of FIT kits were returned within 90 days and 7.8% were abnormal. DISCUSSION: We successfully implemented a population-based MFP at multiple regional VA sites and recommend that these efforts be spread across VA. Our model of regional leadership, facility champions and using centralised resources can be adaptable to other large healthcare systems. MFPs support catch-up from disrupted care by addressing access to CRC screening, unburden primary care visits and conserve limited procedural resources.

Spontaneous ovarian adenocarcinoma in the domestic turkey breeder hen (Meleagris gallopavo): effects of photoperiod and melatonin.

OBJECTIVES: The effect of photoperiod or melatonin treatments on ovarian adenocarcinoma in turkey breeder hens (Meleagris gallopavo) was investigated to evaluate the usefulness of this animal as a model for studying ovarian cancer. METHODS: In Experiment 1, photoperiod effects were tested by exposing turkeys with ovarian tumors to 8 wks of short days (8:16LD) followed by a 12 wk period of long days (16:8LD). In Experiment 2, exogenous melatonin was administered to turkeys during long day-induced development of ovarian tumors. In both experiments, the stage of tumor growth was scored weekly on a scale of 0 to 4. RESULTS: It was clear that exposure to short days produced complete regression of tumors, with a mean time to score 0 of 4.4 wks. Following re-exposure to a long photoperiod, all of the same birds showed re-growth of the ovarian tumor with a mean time to first palpable detection of 5.4 wks. When melatonin was administered daily during the long photoperiod (Experiment 2), there was a significant delay in the re-growth of tumors. CONCLUSION: It was clear from this study that the growth of solid ovarian tumors in the turkey breeder hen was promoted by long photoperiods and ceased, to the point of remission, on short photoperiods. Thus, ovarian adenocarcinoma in turkeys can be completely manipulated by photoperiod. In addition, treatment with melatonin attenuates tumor growth in the turkey hen. The results suggest that the domestic turkey hen is a useful in vivo model for studying spontaneous ovarian adenocarcinoma.

Does use of intraoperative irrigation with open or laparoscopic appendectomy reduce post-operative intra-abdominal abscess?

To date, no study shows a decrease in postoperative abscess with the use of irrigation during appendectomy. Postoperative abscess rate for laparoscopic and open appendectomy is 3.3 and 2.6 per cent. The purpose of this study is to determine if irrigation at appendectomy decreases the postoperative intra-abdominal abscess rate. Retrospective chart review of 176 consecutive appendectomies, open (39%) and laparoscopic (61%), at a university affiliated tertiary care facility from July 2007 to November 2008 for use of intraoperative irrigation was performed. Patients under age 18 were excluded. There were no differences between the irrigation groups in regards to age, sex, or weight. Perforation was observed in 28 per cent (50/176), of which 86 per cent (43/50) of patients received intraoperative irrigation. Eleven patients (9.6%) with irrigation developed postoperative abscess compared with two (3.3%) patients without irrigation (P = 0.22). Our results do not show decrease in postoperative intra-abdominal abscess with use of intraoperative irrigation. Thirteen patients developed postoperative abscess: 11 with irrigation, two without irrigation. Ten of 13 patients who developed abscess were perforated; nine with irrigation and one without. These results suggest routine use of intraoperative irrigation for appendectomies does not prevent intra-abdominal abscess formation, adds extra costs, and may be avoided.

Towards ambient temperature-stable vaccines: the identification of thermally stabilizing liquid formulations for measles virus using an innovative high-throughput infectivity assay.

As a result of thermal instability, some live attenuated viral (LAV) vaccines lose substantial potency from the time of manufacture to the point of administration. Developing regions lacking extensive, reliable refrigeration ("cold-chain") infrastructure are particularly vulnerable to vaccine failure, which in turn increases the burden of disease. Development of a robust, infectivity-based high throughput screening process for identifying thermostable vaccine formulations offers significant promise for vaccine development across a wide variety of LAV products. Here we describe a system that incorporates thermal stability screening into formulation design using heat labile measles virus as a prototype. The screening of >11,000 unique formulations resulted in the identification of liquid formulations with marked improvement over those used in commercial monovalent measles vaccines, with <1.0 log loss of activity after incubation for 8h at 40°C. The approach was shown to be transferable to a second unrelated virus, and therefore offers significant promise towards the optimization of formulation for LAV vaccine products.