Arginine Metabolism in Bacterial Pathogenesis and Cancer Therapy.

Antibacterial resistance to infectious diseases is a significant global concern for health care organizations; along with aging populations and increasing cancer rates, it represents a great burden for government healthcare systems. Therefore, the development of therapies against bacterial infection and cancer is an important strategy for healthcare research. Pathogenic bacteria and cancer have developed a broad range of sophisticated strategies to survive or propagate inside a host and cause infection or spread disease. Bacteria can employ their own metabolism pathways to obtain nutrients from the host cells in order to survive. Similarly, cancer cells can dysregulate normal human cell metabolic pathways so that they can grow and spread. One common feature of the adaption and disruption of metabolic pathways observed in bacterial and cancer cell growth is amino acid pathways; these have recently been targeted as a novel approach to manage bacterial infections and cancer therapy. In particular, arginine metabolism has been illustrated to be important not only for bacterial pathogenesis but also for cancer therapy. Therefore, greater insights into arginine metabolism of pathogenic bacteria and cancer cells would provide possible targets for controlling of bacterial infection and cancer treatment. This review will summarize the recent progress on the relationship of arginine metabolism with bacterial pathogenesis and cancer therapy, with a particular focus on arginase and arginine deiminase pathways of arginine catabolism.

Pilot study of high-intensity focused ultrasound ablation as a bridging therapy for hepatocellular carcinoma patients wait-listed for liver transplantation.

The objective of this study was to investigate the outcomes of high-intensity focused ultrasound (HIFU) ablation as a bridging therapy for patients with hepatocellular carcinoma (HCC) who had been wait-listed for deceased donor liver transplantation (DDLT). Adult patients with unresectable and unablatable HCCs within the University of California San Francisco criteria who had been wait-listed for DDLT were screened for their suitability for HIFU ablation as a bridging therapy if they were not suitable for transarterial chemoembolization (TACE). Treatment outcomes for patients receiving HIFU ablation, TACE, and best medical treatment (BMT) were compared. Fifty-one patients were included in the analysis. Before the introduction of HIFU ablation, only 39.2% of the patients had received bridging therapy (TACE only, n = 20). With HIFU ablation in use, the rate increased dramatically to 80.4% (TACE + HIFU, n = 41). The overall dropout rate was 51% (n = 26). Patients in the BMT group had a significantly higher dropout rate (P = 0.03) and significantly poorer liver function as reflected by higher Model for End-Stage Liver Disease scores and higher Child-Pugh grading. Clinically relevant ascites was found in 5 patients in the HIFU group and 2 patients in the BMT group, but none was found in the TACE group (P = 0.01 and P = 0.03, respectively). The TACE and HIFU groups had comparable percentages of tumor necrosis in excised livers (P = 0.35), and both were significantly higher than that in the BMT group (P = 0.01 and P = 0.02, respectively). In conclusion, HIFU ablation was safe even for HCC patients with Child-Pugh C disease. Its adoption increased the percentage of patients receiving bridging therapy from 39.2% to 80.4%. A randomized controlled trial for further validation of its efficacy is warranted.

Closing the loop - the role of pathologists in digital and computational pathology research.

An increasing number of manuscripts related to digital and computational pathology are being submitted to The Journal of Pathology: Clinical Research as part of the continuous evolution from digital imaging and algorithm-based digital pathology to computational pathology and artificial intelligence. However, despite these technological advances, tissue analysis still relies heavily on pathologists' annotations. There are three crucial elements to the pathologist's role during annotation tasks: granularity, time constraints, and responsibility for the interpretation of computational results. Granularity involves detailed annotations, including case level, regional, and cellular features; and integration of attributions from different sources. Time constraints due to pathologist shortages have led to the development of techniques to expedite annotation tasks from cell-level attributions up to so-called unsupervised learning. The impact of pathologists may seem diminished, but their role is crucial in providing ground truth and connecting pathological knowledge generation with computational advancements. Measures to display results back to pathologists and reflections about correctly applied diagnostic criteria are mandatory to maintain fidelity during human-machine interactions. Collaboration and iterative processes, such as human-in-the-loop machine learning are key for continuous improvement, ensuring the pathologist's involvement in evaluating computational results and closing the loop for clinical applicability. The journal is interested particularly in the clinical diagnostic application of computational pathology and invites submissions that address the issues raised in this editorial.

High-intensity focused ultrasound ablation as a bridging therapy for hepatocellular carcinoma patients awaiting liver transplantation.

The scarcity of liver grafts in Asia leads to a significant dropout of patients from liver transplant waiting lists, particularly patients with hepatocellular carcinoma and a low model for end-stage liver disease score. In order to reduce dropping out, different bridging therapies are employed. We report the use of high-intensity focused ultrasound ablation as a bridging therapy for a patient with hepatocellular carcinoma of stage two and an extremely low platelet count (20X109/L). The ablation was successful. Blood tests showed that his liver function was similar before and after the treatment. No adhesion was encountered in the liver transplantation performed six months later.

HBx-K130M/V131I Promotes Liver Cancer in Transgenic Mice via AKT/FOXO1 Signaling Pathway and Arachidonic Acid Metabolism.

Chronic hepatitis B viral (HBV) infection remains a high underlying cause for hepatocellular carcinoma (HCC) worldwide, while the genetic mechanisms behind this remain unclear. This study elucidated the mechanisms contributing to tumor development induced by the HBV X (HBx) gene of predominantly Asian genotype B HBV and its common HBx variants. To compare the potential tumorigenic effects of K130M/V131I (Mut) and wild-type (WT) HBx on HCC, the Sleeping Beauty (SB) transposon system was used to deliver HBx Mut and WT into the livers of fumarylacetoacetate hydrolase (Fah)-deficient mice and in the context of transformation related protein 53 (Trp53) deficiency. From our results, HBx Mut had a stronger tumorigenic effect than its WT variant. Also, inflammation, necrosis, and fibrosis were evident in HBx experimental animals. Reduction of forkhead box O1 (FOXO1) with increased phosphorylation of upstream serine/threonine kinase (AKT) was detected under HBx Mut overexpression. Thus, it is proposed that HBx Mut enhances disease progression by reducing FOXO1 via phosphorylation of AKT. At the metabolomic level, HBx altered the expression of genes that participated in arachidonic acid (AA) metabolism, as a result of inflammation via accumulation of proinflammatory factors such as prostaglandins and leukotriene in liver. Taken together, the increased rate of HCC observed in chronic hepatitis B patients with K130M/V131I-mutated X protein, may be due to changes in AA metabolism and AKT/FOXO1 signaling. IMPLICATIONS: Our findings suggested that HBx-K130M/V131I-mutant variant promoted HCC progression by activating AKT/FOXO1 pathway and inducing stronger inflammation in liver via AA metabolism.

Fine needle aspiration cytology of invasive micropapillary carcinoma of the breast.

AIM: To determine the pathognomonic diagnostic cytological features of invasive micropapillary carcinoma of the breast which is a poor prognostic subtype of infiltrating ductal carcinoma. METHODS: A series of 20 histologically proven tumours were reviewed retrospectively to evaluate the various cytological features, including tumour morules, isolated malignant cells, staghorn epithelial structures, mucinous background and apocrine metaplasia. RESULTS: Tumour morules formation and isolated malignant cells were the two most reliable and constant cytological features, being present in 75% (15/20 cases) of cases. Staghorn epithelial structures were present in 35% (7 cases). Mucinous background (2 cases, 10%) and apocrine metaplasia (4 cases, 20%) of the tumour cells were seen in a few cases only and did not appear very helpful. CONCLUSION: Tumour morules formation, isolated malignant cells and staghorn epithelial structures are the most reliable cytological features, and the presence of these should raise suspicion of invasive micropapillary carcinoma.

Histopathological evaluation of liver fibrosis and cirrhosis regression.

The hepatic repair complex in the setting of cirrhosis has received increasing attention, as it implies the regression of cirrhosis, which was traditionally taken to be an irreversible state. In this brief review, the patterns of fibrosis, the existing staging systems for chronic liver disease and the histopathological features of cirrhosis regression are discussed.

Liver metastasis of meningeal hemangiopericytoma: a study of 5 cases.

Mesenchymal tumors in the liver, whether primary or metastatic, are rare. Meningeal hemangiopericytoma (HPC) is characteristically associated with delayed metastasis and the liver is one of the most common sites. Despite its consistent histological features, a pathological diagnosis of HPC in the liver is sometimes not straightforward due to its rarity and usually remote medical history of the primary meningeal tumor. In this report, the clinicopathological features of 5 cases of metastatic HPC to the liver were reviewed and described.

High-intensity focused ultrasound ablation: an effective bridging therapy for hepatocellular carcinoma patients.

AIM: To analyze whether high-intensity focused ultrasound (HIFU) ablation is an effective bridging therapy for patients with hepatocellular carcinoma (HCC). METHODS: From January 2007 to December 2010, 49 consecutive HCC patients were listed for liver transplantation (UCSF criteria). The median waiting time for transplantation was 9.5 mo. Twenty-nine patients received transarterial chemoembolization (TACE) as a bringing therapy and 16 patients received no treatment before transplantation. Five patients received HIFU ablation as a bridging therapy. Another five patients with the same tumor staging (within the UCSF criteria) who received HIFU ablation but not on the transplant list were included for comparison. Patients were comparable in terms of Child-Pugh and model for end-stage liver disease scores, tumor size and number, and cause of cirrhosis. RESULTS: The HIFU group and TACE group showed no difference in terms of tumor size and tumor number. One patient in the HIFU group and no patient in the TACE group had gross ascites. The median hospital stay was 1 d (range, 1-21 d) in the TACE group and two days (range, 1-9 d) in the HIFU group (P < 0.000). No HIFU-related complication occurred. In the HIFU group, nine patients (90%) had complete response and one patient (10%) had partial response to the treatment. In the TACE group, only one patient (3%) had response to the treatment while 14 patients (48%) had stable disease and 14 patients (48%) had progressive disease (P = 0.00). Seven patients in the TACE group and no patient in the HIFU group dropped out from the transplant waiting list (P = 0.559). CONCLUSION: HIFU ablation is safe and effective in the treatment of HCC for patients with advanced cirrhosis. It may reduce the drop-out rate of liver transplant candidate.