Automated Measurements of Body Composition in Abdominal CT Scans Using Artificial Intelligence Can Predict Mortality in Patients With Cirrhosis.

Body composition measures derived from already available electronic medical records (computed tomography [CT] scans) can have significant value, but automation of measurements is needed for clinical implementation. We sought to use artificial intelligence to develop an automated method to measure body composition and test the algorithm on a clinical cohort to predict mortality. We constructed a deep learning algorithm using Google's DeepLabv3+ on a cohort of de-identified CT scans (n = 12,067). To test for the accuracy and clinical usefulness of the algorithm, we used a unique cohort of prospectively followed patients with cirrhosis (n = 238) who had CT scans performed. To assess model performance, we used the confusion matrix and calculated the mean accuracy of 0.977 ± 0.02 (0.975 ± 0.018 for the training and test sets, respectively). To assess for spatial overlap, we measured the mean intersection over union and mean boundary contour scores and found excellent overlap between the manual and automated methods with mean scores of 0.954 ± 0.030, 0.987 ± 0.009, and 0.948 ± 0.039 (0.983 ± 0.013 for the training and test set, respectively). Using these automated measurements, we found that body composition features were predictive of mortality in patients with cirrhosis. On multivariate analysis, the addition of body composition measures significantly improved prediction of mortality for patients with cirrhosis over Model for End-Stage Liver Disease alone (P < 0.001). Conclusion: The measurement of body composition can be automated using artificial intelligence and add significant value for incidental CTs performed for other clinical indications. This is proof of concept that this methodology could allow for wider implementation into the clinical arena.

Risk of Hepatocellular Cancer Recurrence in Hepatitis C Virus+ Patients Treated with Direct-Acting Antiviral Agents.

BACKGROUND: With advent of direct-acting antiviral agents (DAA), hepatitis C virus (HCV) treatment is dramatically increasing. Although few studies reported rates of hepatocellular carcinoma (HCC) recurrence following DAA treatment, there have been no studies that followed sufficient number of DAA-treated patients after successful HCC treatment to examine HCC recurrence. METHODS: We conducted a cohort study of HCV+ patients who had successfully treated HCC before initiating DAAs. We conducted medical record reviews to confirm HCC diagnosis, treatment, and remission prior to DAA initiation, and subsequent HCC recurrence. We calculated HCC recurrence rate and examined the recurrent tumor characteristics. We used Cox proportional hazard model to identify factors associated with HCC recurrence. RESULTS: We identified 264 HCV+ patients who received DAAs after an average of 30.9 (20.6) months following HCC treatment. HCC recurred in 26.1% patients during 23.3 (9.8) months follow-up, at a rate of 0.38 [0.30, 0.48] per 1000 person-month. Most (82.3%) recurrent HCC were early stage. Receiving non-curative treatment for HCC was associated with a higher risk of recurrence than curative treatment (HRadj = 2.06, [1.24, 3.40]). The risk of HCC recurrence decreased with longer duration between HCC treatment completion and DAA initiation (HRadj = 0.97, [0.95, 0.99] per additional month). Compared with patients who achieved sustained virological response (SVR), those without SVR had significantly increased risk of HCC recurrence (HRadj = 4.17, [1.48, 11.75]). CONCLUSIONS: We conclude that most HCV+ patients with HCC benefit from DAA treatment; however, timing of DAA initiation after HCC treatment should be carefully considered.

Human Intestinal Enteroids: New Models to Study Gastrointestinal Virus Infections.

Human rotavirus (HRV) and human norovirus (HuNoV) infections are recognized as the most common causes of epidemic and sporadic cases of gastroenteritis worldwide. The study of these two human gastrointestinal viruses is important for understanding basic virus-host interactions and mechanisms of pathogenesis and to establish models to evaluate vaccines and treatments. Despite the introduction of live-attenuated vaccines to prevent life-threatening HRV-induced disease, the burden of HRV illness remains significant in low-income and less-industrialized countries, and small animal models or ex vivo models to study HRV infections efficiently are lacking. Similarly, HuNoVs remained non-cultivatable until recently. With the advent of non-transformed human intestinal enteroid (HIE) cultures, we are now able to culture and study both clinically relevant HRV and HuNoV in a biologically relevant human system. Methods described here will allow investigators to use these new culture techniques to grow HRV and HuNoV and analyze new aspects of virus replication and pathogenesis.

Guilt by association: intestinal metaplasia does not progress to gastric cancer.

PURPOSE OF REVIEW: This review integrates the new thinking about relationships between gastric cancer and intestinal metaplasia/pseudopyloric metaplasia (SPEM). We address whether recent studies have closed or widened the knowledge gap regarding gastric cancer pathogenesis in mice or humans. RECENT FINDINGS: Recent studies in mouse models have provided a variety of new insights into the cellular origin and progression of events resulting in gastric cancer. Many suggest a direct transformation from intestinal metaplasia/pseudopyloric metaplasia/SPEM to gastric cancer. However, results from different investigator and models are conflicting and often describe events not present in studies in humans. SUMMARY: Both Helicobacter pylori-associated and autoimmune gastritis may produce gastric atrophy with extensive intestinal metaplasia and an abnormal gastric microbiome. However, only H. pylori gastritis carries a risk for adenocarcinoma. The differences reported with mouse models can best be explained as the results of different models of regeneration and repair rather than as models of gastric cancer. Overall, the data remains consistent with the original hypothesis that gastric cancer results from increased genetic instability of gastric stem cells rather than a direct transition from metaplasia to cancer. Intestinal metaplasia, pseudopyloric metaplasia, and SPEM have all been falsely accused based on guilt by association.

Engineered Human Gastrointestinal Cultures to Study the Microbiome and Infectious Diseases.

New models to study the intestine are key to understanding intestinal diseases and developing novel treatments. Intestinal organ-like culture systems (organoids and enteroids) have substantially advanced the study of the human gastrointestinal tract. Stem cell-derived cultures produce self-organizing structures that contain the multiple differentiated intestinal epithelial cell types including enterocytes, goblet, Paneth, and enteroendocrine cells. Understanding host-microbial interactions is one area in which these cultures are expediting major advancements. This review discusses how organoid and enteroid cultures are biologically and physiologically relevant systems to investigate the effects of commensal organisms and study the pathogenesis of human infectious diseases. These cultures can be established from many donors and they retain the genetic and biologic properties of the donors, which can lead to the discovery of host-specific factors that affect susceptibility to infection and result in personalized approaches to treat individuals. The continued development of these cultures to incorporate more facets of the gastrointestinal tract, including neurons, immune cells, and the microbiome, will unravel new mechanisms regulating host-microbial interactions with the long-term goal of translating findings into novel preventive or therapeutic treatments for gastrointestinal infections.

Determinants and Outcomes of Hospice Utilization Among Patients with Advance-Staged Hepatocellular Carcinoma in a Veteran Affairs Population.

BACKGROUND: Hospice provides integrative palliative care for advance-staged hepatocellular carcinoma (HCC) patients, but hospice utilization in HCC patients in the USA is not clearly understood. AIMS: We examined hospice use and subsequent clinical course in advance-staged HCC patients. METHODS: We conducted a retrospective study on a national, Veterans Affairs cohort with stage C or D HCC. We evaluated demographics, clinical factors, treatment, and clinical course in relation to hospice use. RESULTS: We identified 814 patients with advanced HCC, of whom 597 (73.3%) used hospice. Oncologist management consistently predicted hospice use, irrespective of HCC treatment [no treatment: OR 2.25 (1.18-4.3), treatment: OR 1.80 (1.10-2.95)]. Among patients who received HCC treatment, hospice users were less likely to have insurance beyond VA benefits (47.2 vs. 60.0%, p = 0.01). Among patients without HCC treatment, hospice users were older (62.2 [17.2] vs. 60.2 [14.0] years, p = 0.05), white (62.1 vs. 52.9%, p = 0.01), resided in the Southern USA (39.5 vs. 31.8%, p = 0.05), and had a performance score ≥ 3 (41.9 vs. 31.8%, p = 0.01). The median time from hospice entry to death or end of study was 1.05 [2.96] months for stage C and 0.53 [1.18] months for stage D patients. CONCLUSIONS: 26.7% advance-staged HCC patients never entered hospice, representing potential missed opportunities for improving end-of-life care. Age, race, location, performance, insurance, and managing specialty can predict hospice use. Differences in managing specialty and short-term hospice use suggest that interventions to optimize early palliative care are necessary.

Epithelial WNT Ligands Are Essential Drivers of Intestinal Stem Cell Activation.

Intestinal stem cells (ISCs) maintain and repair the intestinal epithelium. While regeneration after ISC-targeted damage is increasingly understood, injury-repair mechanisms that direct regeneration following injuries to differentiated cells remain uncharacterized. The enteric pathogen, rotavirus, infects and damages differentiated cells while sparing all ISC populations, thus allowing the unique examination of the response of intact ISC compartments during injury-repair. Upon rotavirus infection in mice, ISC compartments robustly expand and proliferating cells rapidly migrate. Infection results specifically in stimulation of the active crypt-based columnar ISCs, but not alternative reserve ISC populations, as is observed after ISC-targeted damage. Conditional ablation of epithelial WNT secretion diminishes crypt expansion and ISC activation, demonstrating a previously unknown function of epithelial-secreted WNT during injury-repair. These findings indicate a hierarchical preference of crypt-based columnar cells (CBCs) over other potential ISC populations during epithelial restitution and the importance of epithelial-derived signals in regulating ISC behavior.

Gastrointestinal microphysiological systems.

Gastrointestinal diseases are a significant health care and economic burden. Prevention and treatment of these diseases have been limited by the available human biologic models. Microphysiological systems comprise organ-specific human cultures that recapitulate many structural, biological, and functional properties of the organ in smaller scale including aspects of flow, shear stress and chemical gradients. The development of intestinal microphysiological system platforms represents a critical component in improving our understanding, prevention, and treatment of gastrointestinal diseases. This minireview discusses: shortcomings of classical cell culture models of the gastrointestinal tract; human intestinal enteroids as a new model and their advantages compared to cell lines; why intestinal microphysiological systems are needed; potential functional uses of intestinal microphysiological systems in areas of drug development and modeling acute and chronic diseases; and current challenges in the development of intestinal microphysiological systems. Impact statement The development of a gastrointestinal MPS has the potential to facilitate the understanding of GI physiology. An ultimate goal is the integration of the intestinal MPS with other organ MPS. The development and characterization of nontransformed human intestinal cultures for use in MPS have progressed significantly since the inception of the MPS program in 2012, and these cultures are a key component of advancing MPS. Continued efforts are needed to optimize MPS to comprehensively and accurately recapitulate the complexity of the intestinal epithelium within intestinal tissue. These systems will need to include peristalsis, flow, and oxygen gradients, with incorporation of vascular, immune, and nerve cells. Regional cellular organization of crypt and villus areas will also be necessary to better model complete intestinal structure.

SPDEF Induces Quiescence of Colorectal Cancer Cells by Changing the Transcriptional Targets of ß-catenin.

BACKGROUND & AIMS: The canonical Wnt signaling pathway activates the transcriptional activity of ß-catenin. This pathway is often activated in colorectal cancer cells, but strategies to block it in tumors have not been effective. The SAM pointed domain containing ETS transcription factor (SPDEF) suppresses formation of colon tumors by unclear mechanisms. We investigated these mechanisms and the effects of SPDEF on ß-catenin activity in mouse models of colorectal cancer (CRC), CRC cell lines, and mouse and human normal and cancer colonoids. METHODS: We performed studies of Lgr5CreERT2; ß-cateninexon3; Rosa26LSL-rtta-ires-EGFP; TRE-Spdef mice, which express an oncogenic form of ß-catenin in Lgr5-positive ISCs upon administration of tamoxifen and SPDEF upon administration of tetracycline. CRC lines (HCT116 and SW480) were engineered to express inducible tagged SPDEF or vector (control) and subcutaneously injected into immunodeficient NSG mice. We generated SPDEF-inducible human colonoids, including a line derived from normal rectal mucosa (control) and an adenocarcinoma line derived from a patient with germline MUTYH mutation. Full-length and truncated forms of SPDEF were expressed in CRC cells; cells were assayed for ß-catenin activity and studied in immunoprecipitation and chromatin immunoprecipitation assays. RESULTS: Expression of SPDEF was sufficient to inhibit intestinal tumorigenesis by activated ß-catenin, block tumor cell proliferation, and restrict growth of established tumors. In tumor cells with activated ß -catenin, expression of SPDEF induced a quiescent state, which was reversed when SPDEF expression was stopped. In mouse and human normal and tumor-derived enteroids/colonoids, those that expressed SPDEF for 3 days were significantly smaller. SPDEF inhibited the transcriptional activity of ß-catenin via a protein-protein interaction, independent of SPDEF DNA binding capacity. SPDEF disrupted ß-catenin binding to TCF1 and TCF3, displacing ß-catenin from enhancer regions of genes that regulate the cell cycle but not genes that regulate stem cell activities. CONCLUSIONS: In studies of mice and human CRC, we found that SPDEF induces a quiescent state in CRC cells by disrupting binding of ß-catenin to TCF1 and TCF3 and regulation of genes that control the cell cycle. In this model, ß-catenin activity determines the proliferation or quiescence of CRC cells based on the absence or presence of SPDEF.

Evaluation of carotid angioplasty and stenting for radiation-induced carotid stenosis.

BACKGROUND AND PURPOSE: We aimed to evaluate the procedural safety, clinical, and angiographic outcome of carotid angioplasty and stenting for high-grade (≥70%) radiation-induced carotid stenosis (RIS) using atherosclerotic stenosis (AS) as a control. METHODS: In this 6-year prospective nonrandomized study, we compared the carotid angioplasty and stenting outcome of 65 consecutive patients (84 vessels) with RIS with that of a control group of 129 consecutive patients (150 vessels) with AS. Study end points were 30-day periprocedural stroke or death, ipsilateral ischemic stroke, technical success, procedural characteristics, instent restenosis (ISR; ≥50%) and symptomatic ISR. RESULTS: The median follow-up was 47.3 months (95% confidence interval, 26.9-61.6). Imaging assessment was available in 74 vessels (RIS) and 120 vessels (AS) in 2 years. Comparing RIS group with AS group, the rates of periprocedural stroke or death were 1.5% (1/65) versus 1.6% (2/129; P=1); ipsilateral ischemic stroke rates were 4.6% (3/65) versus 4.7% (6/129; P=1); the annual risks of ipsilateral ischemic stroke were 1.2% (3 patient/254.7 patient year) versus 1.2% (6 patient/494.2 patient year; P=0.89); technical success rates were both 100%. Stenting of common carotid artery and the use of multiple stents was more common in the RIS group (P=0 in both cases); ISR rates were 25.7% (19/74) versus 4.2% (5/120; P<0.001); symptomatic ISR rates were 6.8% (5/74) versus 0.8% (1/120; P=0.031). CONCLUSIONS: The safety, effectiveness, and technical difficulty of carotid angioplasty and stenting for RIS are comparable with that for AS although it is associated with a higher rate of ISR. CLINICAL TRIAL REGISTRATION: This trial was not registered as enrollment started in 2006.

Angiographic features, collaterals, and infarct topography of symptomatic occlusive radiation vasculopathy: a case-referent study.

BACKGROUND AND PURPOSE: Occlusive radiation vasculopathy (ORV) predisposes head-and-neck cancer survivors to ischemic strokes. METHODS: We analyzed the digital subtraction angiography acquired in 96 patients who had first-ever transient ischemic attack or ischemic strokes attributed to ORV. Another age-matched 115 patients who had no radiotherapy but symptomatic high-grade (>70%) carotid stenoses were enrolled as referent subjects. Digital subtraction angiography was performed within 2 months from stroke onset and delineated carotid and vertebrobasilar circulations from aortic arch up to intracranial branches. Two reviewers blinded to group assignment recorded all vascular lesions, collateral status, and infarct pattern. RESULTS: ORV patients had less atherosclerotic risk factors at presentation. In referent patients, high-grade stenoses were mostly focal at the proximal internal carotid artery. In contrast, high-grade ORV lesions diffusely involved the common carotid artery and internal carotid artery and were more frequently bilateral (54% versus 22%), tandem (23% versus 10%), associated with complete occlusion in one or both carotid arteries (30% versus 9%), vertebral artery (VA) steno-occlusions (28% versus 16%), and external carotid artery stenosis (19% versus 5%) (all P<0.05). With comparable rates of vascular anomaly, ORV patients showed more established collateral circulations through leptomeningeal arteries, anterior communicating artery, posterior communicating artery, suboccipital/costocervical artery, and retrograde flow in ophthalmic artery. In terms of infarct topography, the frequencies of cortical or subcortical watershed infarcts were similar in both groups. CONCLUSIONS: ORV angiographic features and corresponding collaterals are distinct from atherosclerotic patterns at initial stroke presentation. Clinical decompensation, despite more extensive collateralization, may precipitate stroke in ORV.

Direct regulation of GTP homeostasis by (p)ppGpp: a critical component of viability and stress resistance.

Cells constantly adjust their metabolism in response to environmental conditions, yet major mechanisms underlying survival remain poorly understood. We discover a posttranscriptional mechanism that integrates starvation response with GTP homeostasis to allow survival, enacted by the nucleotide (p)ppGpp, a key player in bacterial stress response and persistence. We reveal that (p)ppGpp activates global metabolic changes upon starvation, allowing survival by regulating GTP. Combining metabolomics with biochemical demonstrations, we find that (p)ppGpp directly inhibits the activities of multiple GTP biosynthesis enzymes. This inhibition results in robust and rapid GTP regulation in Bacillus subtilis, which we demonstrate is essential to maintaining GTP levels within a range that supports viability even in the absence of starvation. Correspondingly, without (p)ppGpp, gross GTP dysregulation occurs, revealing a vital housekeeping function of (p)ppGpp; in fact, loss of (p)ppGpp results in death from rising GTP, a severe and previously unknown consequence of GTP dysfunction.