CSF1R+ Macrophages Sustain Pancreatic Tumor Growth through T Cell Suppression and Maintenance of Key Gene Programs that Define the Squamous Subtype.

Pancreatic ductal adenocarcinoma (PDAC) is resistant to most therapies including single-agent immunotherapy and has a dense desmoplastic stroma, and most patients present with advanced metastatic disease. We reveal that macrophages are the dominant leukocyte population both in human PDAC stroma and autochthonous models, with an important functional contribution to the squamous subtype of human PDAC. We targeted macrophages in a genetic PDAC model using AZD7507, a potent selective inhibitor of CSF1R. AZD7507 caused shrinkage of established tumors and increased mouse survival in this difficult-to-treat model. Malignant cell proliferation diminished, with increased cell death and an enhanced T cell immune response. Loss of macrophages rewired other features of the TME, with global changes in gene expression akin to switching PDAC subtypes. These changes were markedly different to those elicited when neutrophils were targeted via CXCR2. These results suggest targeting the myeloid cell axis may be particularly efficacious in PDAC, especially with CSF1R inhibitors

Medical cannabis and driving

Medical cannabis use is increasingly common in Australia. Patients and physicians need to be aware of the important implications that such use may have for driving. Objective The aim of this article is to briefly review the scientific evidence regarding cannabis and driving impairment and discuss current legal issues affecting patients, as well as to update physicians on relevant issues and the best guidance to offer their patients. Discussion Delta-9-tetrahydrocannabinol (THC) impairs driving performance and can increase crash risk. These effects are more pronounced in people who use THC occasionally and can last for up to eight hours with oral THC products. There is no evidence that cannabidiol (CBD) impairs driving. Patients using THC-containing products should avoid driving and other safety-sensitive tasks (eg operating machinery), particularly during initiation of treatment and in the hours immediately following each dose. Patients may test positive for THC even if they do not feel impaired, and medical cannabis use does not currently exempt patients from mobile (roadside) drug testing and associated legal sanctions.Full Tex

Are blood and oral fluid Δ9-tetrahydrocannabinol (THC) and metabolite concentrations related to impairment? A meta-regression analysis

Blood and oral fluid Δ9-tetrahydrocannabinol (THC) concentrations are often used to identify cannabis-impaired drivers. We used meta-analytic techniques to characterise the relationships between biomarkers of cannabis use, subjective intoxication, and impairment of driving and driving-related cognitive skills. Twenty-eight publications and 822 driving-related outcomes were reviewed. Each outcome was measured in concert with one or more biomarkers of cannabis/THC use and/or subjective intoxication. Higher blood THC and 11−OH-THC concentrations, oral fluid THC concentrations and subjective ratings of intoxication were associated with greater impairment in ‘other’ (mostly occasional) cannabis users (p's0.10), although the analyses were less robust. Blood and oral fluid THC concentrations are relatively poor indicators of cannabis/THC-induced impairment.Full Tex

The why behind the high: determinants of neurocognition during acute cannabis exposure

Acute cannabis intoxication may induce neurocognitive impairment and is a possible cause of human error, injury and psychological distress. One of the major concerns raised about increasing cannabis legalization and the therapeutic use of cannabis is that it will increase cannabis-related harm. However, the impairing effect of cannabis during intoxication varies among individuals and may not occur in all users. There is evidence that the neurocognitive response to acute cannabis exposure is driven by changes in the activity of the mesocorticolimbic and salience networks, can be exacerbated or mitigated by biological and pharmacological factors, varies with product formulations and frequency of use and can differ between recreational and therapeutic use. It is argued that these determinants of the cannabis-induced neurocognitive state should be taken into account when defining and evaluating levels of cannabis impairment in the legal arena, when prescribing cannabis in therapeutic settings and when informing society about the safe and responsible use of cannabis. Acute cannabis exposure modulates numerous aspects of neurocognitive function; however, the effects experienced by individuals are highly variable. Ramaekers and colleagues here review the neural basis of cannabis-induced neurocognitive changes and response variability, and consider the legal, therapeutic and societal implications