Abstract WMP67: Evaluation Of The Implementation Of An Ai Tool For Large Vessel Occlusion: Impact On Radiologists’ Workflow And Patient Outcomes

Timely and accurate diagnosis of a large vessel occlusion (LVO) is critical for prompt initiation of thrombectomy treatment to reduce morbidity and mortality in acute ischemic stroke patients. Recently, artificial intelligence (AI) tools to aid stroke triage have shown promise for their accuracy and speed. However, little is known about the impact of the clinical integration of AI on efficiency metrics and patient outcomes. This study aims to evaluate the impact of an AI-based LVO detection tool on three main areas: (1) performance metrics, (2) radiologist workflow, and (3) ischemic stroke metrics and outcomes. This single center retrospective analysis includes patients with suspected acute stroke who underwent CT angiograms (CTA) in a three month period before and after the implementation of an AI-based LVO detection tool. CTA of 224 patients pre-implementation and 144 patients post-implementation of the tool were evaluated. The tool correctly identified 93/107 cases, with an accuracy of 87%, sensitivity of 91%, and specificity of 86%. The PPV was 0.64 and the NPV was 0.97. The mean radiology report turnaround time (TAT) using the tool was significantly reduced at 19.9 minutes (SD 32.4) compared to 33.7 minutes (SD 34.7) without the tool (p=0.001). There was a significant improvement in the resident trainee TAT with the LVO tool, with a mean TAT of 17.9 minutes (SD 32.6) compared to 38.4 minutes (SD 33.6) without (p=0.0002). Baseline stroke risk factors were similar between the pre and post-implementation groups. There were no significant differences in stroke metric medians for door-to-image, door-to-needle, door-to-puncture, and door-to-revascularization times and there were no statistically significant differences in NIHSS on arrival, post treatment NIHSS, discharge mRS, or mortality. The findings in clinical outcomes and stroke metrics may be attributable to small sample size. This study validates an AI-based tool in the detection of LVO and demonstrates a significant associated reduction in report TAT, allowing for faster communication of critical findings to ordering clinicians. Further research is needed to evaluate the impact of these tools on stroke benchmarks and clinical outcomes and to establish their role in stroke triage for clinicians.

A Unique Morphological Phenotype in Chemoresistant Triple-Negative Breast Cancer Reveals Metabolic Reprogramming and PLIN4 Expression as a Molecular Vulnerability

The major obstacle in successfully treating triple-negative breast cancer (TNBC) is resistance to cytotoxic chemotherapy, the mainstay of treatment in this disease. Previous preclinical models of chemoresistance in TNBC have suffered from a lack of clinical relevance. Using a single high dose chemotherapy treatment, we developed a novel MDA-MB-436 cell-based model of chemoresistance characterized by a unique and complex morphologic phenotype, which consists of polyploid giant cancer cells giving rise to neuron-like mononuclear daughter cells filled with smaller but functional mitochondria and numerous lipid droplets. This resistant phenotype is associated with metabolic reprogramming with a shift to a greater dependence on fatty acids and oxidative phosphorylation. We validated both the molecular and histologic features of this model in a clinical cohort of primary chemoresistant TNBCs and identified several metabolic vulnerabilities including a dependence on PLIN4, a perilipin coating the observed lipid droplets, expressed both in the TNBC-resistant cells and clinical chemoresistant tumors treated with neoadjuvant doxorubicin-based chemotherapy. These findings thus reveal a novel mechanism of chemotherapy resistance that has therapeutic implications in the treatment of drug-resistant cancer. IMPLICATIONS: These findings underlie the importance of a novel morphologic-metabolic phenotype associated with chemotherapy resistance in TNBC, and bring to light novel therapeutic targets resulting from vulnerabilities in this phenotype, including the expression of PLIN4 essential for stabilizing lipid droplets in resistant cells.

Reduction of chronic hepatitis B-related hepatocellular carcinoma with anti-viral therapy, including low risk patients

BACKGROUND

Anti-viral therapy in chronic hepatitis B (CHB) is associated with a reduced risk of hepatocellular carcinoma (HCC) primary described in patients with cirrhosis.

AIM

To examine the effects of treatment on HCC incidence in CHB with and without cirrhosis, after adjustment for background risks.

METHODS

A total of 2255 CHB patients from a US cohort (973 received anti-viral therapy) and 3653 patients from the community-based Taiwanese REVEAL-HBV study, none of whom received treatment. We used Cox proportional hazard models to calculate the risk of developing HCC after adjustment with the previously validated REACH-B risk score.

RESULTS

We found 273 incident cases of HCC. After adjustment, therapy lowered the risk of HCC development in the US treated cohort when compared to the US untreated cohort (HR 0.31; 95% CI: 0.15-0.66; P = 0.002). HCC risk reduction was also confirmed when compared to the REVEAL cohort (HR 0.22; 95% CI: 0.12-0.40; P < 0.001). Each REACH-B point was associated with a 53% increased risk of HCC (HR 1.53; 95% CI 1.46-1.59; P < 0.001). We found a significant statistical reduction in HCC incidence with therapy regardless of gender, age, cirrhosis status, HBeAg serology, alanine aminotransferase level, REACH-B score or treatment medication. Therapy was beneficial to those with mildly- to moderately elevated HBV DNA levels (>2000 IU/mL) and of even greater benefit to those with levels >200 000 IU/mL.

CONCLUSION

After adjustment for background risk, anti-viral therapy was associated with a significant reduction in HCC incidence in both community and real-life clinical cohorts, including in those patients previously thought to be at low risk.

Occurrence of Schistocephalus solidus in anadromous threespine stickleback

Plerocercoids of the cestode Schistocephalus solidus are reported for the first time from the body cavity of anadromous threespine stickleback inhabiting Mud Lake, Alaska. Most infected stickleback harbored a single large plerocerciod (mean weight  =  0.447 g, range  =  0.228-0.716 g). The overall prevalence of plerocercoids across genders and 2 yr of samples was 1.4%, but prevalence was significantly greater in males than in females. Because of the large size of the plerocercoids, anadromous stickleback were probably infected as juveniles before leaving the lake, suggesting that plerocercoids can live in the body cavity of oceanic stickleback for several years.

Guidelines for application of chemical-specific adjustment factors in dose/concentration-response assessment

This manuscript addresses guidance in the use of kinetic and dynamic data to inform quantitatively extrapolations for interspecies differences and human variability in dose-response assessment developed in a project of the International Programme on Chemical Safety (IPCS) initiative on Harmonisation of Approaches to the Assessment of Risk from Exposure to Chemicals. The guidance has been developed and refined through a series of planning and technical meetings and larger workshops of a broad range of participants from academia, government agencies and the private sector. The guidance for adequacy of data for replacement of common defaults for interspecies differences and human variability is presented in the context of several generic categories including: determination of the active chemical species, choice of the appropriate metric (kinetic components) or endpoint (dynamic components) and nature of experimental data, the latter which includes reference to the relevance of population, route and dose and the adequacy of the number of subjects/samples. The principal objective of this guidance developed primarily as a resource for risk assessors, is to foster better understanding of the components of and criteria for adequacy of chemical-specific data to quantitate interspecies differences and human variability in kinetics and dynamics. It is anticipated that this guidance will also encourage the development of appropriate data and facilitate their incorporation in a consistent fashion in dose-response assessment for regulatory purposes (IPCS, 2001).

Harmonization of cancer and noncancer risk assessment: proceedings of a consensus-building workshop

Significant advancements have been made toward the use of all relevant scientific information in health risk assessments. This principle has been set forth in risk-assessment guidance documents of international agencies including those of the World Health Organization's International Programme on Chemical Safety, the U.S. Environmental Protection Agency, and Health Canada. Improving the scientific basis of risk assessment is a leading strategic goal of the Society of Toxicology. In recent years, there has been a plethora of mechanistic research on modes of chemical toxicity that establishes mechanistic links between noncancer responses to toxic agents and subsequent overt manifestations of toxicity such as cancer. The research suggests that differences in approaches to assessing risk of cancer and noncancer toxicity need to be resolved and a common broad paradigm for dose-response assessments developed for all toxicity endpoints. In November 1999, a workshop entitled "Harmonization of Cancer and Noncancer Risk Assessment" was held to discuss the most critical issues involved in developing a more consistent and unified approach to risk assessment for all endpoints. Invited participants from government, industry, and academia discussed focus questions in the areas of mode of action as the basis for harmonization, common levels of adverse effect across toxicities for use in dose-response assessments, and scaling and uncertainty factors. This report summarizes the results of those discussions. There was broad agreement, albeit not unanimous, that current science supports the development of a harmonized set of principles that guide risk assessments for all toxic endpoints. There was an acceptance among the participants that understanding the mode of action of a chemical is ultimately critical for nondefault risk assessments, that common modes of action for different toxicities can be defined, and that our approach to assessing toxicity should be biologically consistent.

Isolation of lumenal proteins from spinach thylakoid membranes by triton X-114 phase partitioning

The proteins present in the thylakoid lumen of higher plant chloroplasts have not been rigorously examined. In this communication we present a simple and rapid procedure for the isolation of the soluble proteins and extrinsic membrane proteins present in the thylakoid lumen from spinach. Our procedure involves extensive washing of the thylakoid membranes followed by Triton X-114 phase partitioning. When analyzed by one-dimensional polyacrylamide gel electrophoresis (PAGE), we obtain results which are very similar to those obtained by Kieselbach et al. using more classical methods [T. Kieselbach, A. Hagman, B. Andersson, W.P. Schroder, J. Biol. Chem. 273 (1998) 6710-6716]. About 25 major proteins are observed upon Coomassie blue staining. Upon two-dimensional isoelectric focusing-sodium dodecyl sulfate-PAGE and either Coomassie blue or silver staining, however, numerous other protein components are resolved. Our findings indicate that the total number of proteins (soluble and extrinsic membrane) present in the lumen may exceed 150.

Workshop to identify critical windows of exposure for children's health: cancer work group summary

We considered whether there are discrete windows of vulnerability in the development of cancer and which time periods may be of the greatest importance. Cancer was considered broadly, including cancers in childhood as well as adult cancers that may have an in utero or childhood origin. We concluded that there was evidence from animal and epidemiologic studies for causal relationships for preconceptional, in utero, and childhood exposures and cancer occurrence in children and adults. However, the evidence is incomplete and all relevant critical windows may not have been identified. The comprehensive evaluation of the relative importance of specific time windows of exposure is limited. Improvements in the design of epidemiologic studies and additional animal studies of mechanisms are warranted.

Chronic inhalation toxicity and carcinogenicity testing of respirable fibrous particles. Workshop report

On May 8-10, 1995, a workshop on chronic inhalation toxicity and carcinogenicity testing of respirable fibrous particles was held in Chapel Hill, North Carolina. The workshop was sponsored by the Office of Pollution Prevention and Toxics, U.S. Environmental Protection Agency (EPA), in collaboration with the National Institute of Environmental Health Sciences (NIEHS), the National Institute for Occupational Safety and Health (NIOSH), and the Occupational Safety and Health Administration (OSHA). The goal of the workshop was to obtain input from the scientific community on a number of issues related to fiber testing. Major issues for discussion were: (i) the optimal design and conduct of studies of the health effects of chronic inhalation exposure of animals to fibers; (ii) preliminary studies which would be useful guides in designing the chronic exposure study; (iii) mechanistic studies which would be important adjuncts to the chronic exposure study to enable better interpretation of study results and extrapolation of potential effects in exposed humans; and (iv) available screening tests which can be used to develop a minimum data set for (a) making decisions about the potential health hazard of the fibers and (b) prioritizing the need for further testing in a chronic inhalation study. After extensive discussion and debate of the workshop issues, the general consensus of the expert panel is that chronic inhalation studies of fibers in the rat are the most appropriate tests for predicting inhalation hazard and risk of fibers to humans. A number of guidances specific for the design and conduct of prechronic and chronic inhalation studies of fibers in rodents were recommended. For instance, it was recommended that along with other information (decrease in body weight, systemic toxicity, etc.), data should be obtained on lung burdens and bronchoalveolar lavage fluid analysis to assist in establishing the chronic exposure levels. Lung burden data are also important for quantifying aspects of risk assessment related to dosimetric adjustments before extrapolation. Although mechanistic studies are not recommended as part of the standard chronic inhalation studies, the expert panel stressed the need for obtaining mechanistic information as far as possible during the course of subchronic or chronic inhalation studies. At present, no single assay and battery of short-term assays can predict the outcome of a chronic inhalation bioassay with respect to carcinogenic effects. Meanwhile, several short-term in vitro and in vivo studies that may be useful to assess the relative potential of fibrous substances to cause lung toxicity/carcinogenicity have been identified.

Antilipolytic activity of viprostol, a transdermally active antihypertensive PGE2 analog

Viprostol, a novel prostaglandin E2 congener, was assessed for in vitro antilipolytic activity in the spontaneously obese rat. In isolated epididymal adipocytes, viprostol exhibited a dose-dependent inhibition of catecholamine-stimulated lipolysis at concentrations ranging from 10 microM to 1 mM, but was ineffective at lower concentrations. Additionally, viprostol exhibited approximately 50% of the antilipolytic activity of naturally-occurring PGE1 and PGE2 at similar concentrations, but was as potent as PGF2 alpha. At 10 microM, viprostol inhibited maximum catecholamine-stimulated lipolysis by approximately 35% of the total, hormone-stimulated glycerol release. The results of these experiments indicate that viprostol exhibits antilipolytic activity in vitro, but is less potent than the naturally-occurring PGE's to which it is most closely related structurally.