Machine perfusion of the liver and in vivo animal models: A systematic review of the preclinical research landscape.

Machine perfusion (MP) is often referred to as one of the most promising advancements in liver transplantation research of the last few decades, with various techniques and modalities being evaluated in preclinical studies using animal models. However, low scientific rigor and subpar reporting standards lead to limited reproducibility and translational potential, hindering progress. This pre-registered systematic review (PROSPERO: CRD42021234667) aimed to provide a thematic overview of the preclinical research landscape on MP in liver transplantation using in vivo transplantation models and to explore methodological and reporting standards, using the ARRIVE (Animal Research: Reporting of In Vivo Experiments) score. In total 56 articles were included. Studies were evenly distributed across Asia, Europe, and the Americas. Porcine models were used in 57.1% of the studies, followed by rats (39.3%) and dogs (3.6%). In terms of graft type, 55.4% of the studies used donation after cardiac death grafts, while donation after brain death grafts accounted for 37.5%. Regarding MP modalities, the distribution was as follows: 41.5% of articles utilized hypothermic MP, 21.5% normothermic MP, 13.8% subnormothermic MP, and 16.9% utilized hypothermic oxygenated MP. The stringent documentation of ARRIVE elements concerning precise experimental execution, group size and selection, the choice of statistical methods, as well as adherence to the principles of the 3Rs, was notably lacking in the majority of publications, with less than 30% providing comprehensive details. Postoperative analgesia and antibiotics treatment were not documented in 82.1% of all included studies. None of the analyzed studies fully adhered to the ARRIVE Guidelines. In conclusion, the present study emphasizes the importance of adhering to reporting standards to promote reproducibility and adequate animal welfare in preclinical studies in machine perfusion. At the same time, it highlights a clear deficiency in this field, underscoring the need for further investigations into animal welfare-related topics.

Real-world performance analysis of a novel computational method in the precision oncology of pediatric tumors.

BACKGROUND: The utility of routine extensive molecular profiling of pediatric tumors is a matter of debate due to the high number of genetic alterations of unknown significance or low evidence and the lack of standardized and personalized decision support methods. Digital drug assignment (DDA) is a novel computational method to prioritize treatment options by aggregating numerous evidence-based associations between multiple drivers, targets, and targeted agents. DDA has been validated to improve personalized treatment decisions based on the outcome data of adult patients treated in the SHIVA01 clinical trial. The aim of this study was to evaluate the utility of DDA in pediatric oncology. METHODS: Between 2017 and 2020, 103 high-risk pediatric cancer patients (< 21 years) were involved in our precision oncology program, and samples from 100 patients were eligible for further analysis. Tissue or blood samples were analyzed by whole-exome (WES) or targeted panel sequencing and other molecular diagnostic modalities and processed by a software system using the DDA algorithm for therapeutic decision support. Finally, a molecular tumor board (MTB) evaluated the results to provide therapy recommendations. RESULTS: Of the 100 cases with comprehensive molecular diagnostic data, 88 yielded WES and 12 panel sequencing results. DDA identified matching off-label targeted treatment options (actionability) in 72/100 cases (72%), while 57/100 (57%) showed potential drug resistance. Actionability reached 88% (29/33) by 2020 due to the continuous updates of the evidence database. MTB approved the clinical use of a DDA-top-listed treatment in 56 of 72 actionable cases (78%). The approved therapies had significantly higher aggregated evidence levels (AELs) than dismissed therapies. Filtering of WES results for targeted panels missed important mutations affecting therapy selection. CONCLUSIONS: DDA is a promising approach to overcome challenges associated with the interpretation of extensive molecular profiling in the routine care of high-risk pediatric cancers. Knowledgebase updates enable automatic interpretation of a continuously expanding gene set, a "virtual" panel, filtered out from genome-wide analysis to always maximize the performance of precision treatment planning.

Personalized First-Line Treatment of Metastatic Pancreatic Neuroendocrine Carcinoma Facilitated by Liquid Biopsy and Computational Decision Support.

BACKGROUND: We present the case of a 50-year-old female whose metastatic pancreatic neuroendocrine tumor (pNET) diagnosis was delayed by the COVID-19 pandemic. The patient was in critical condition at the time of diagnosis due to the extensive tumor burden and failing liver functions. The clinical dilemma was to choose between two registered first-line molecularly-targeted agents (MTAs), sunitinib or everolimus, or to use chemotherapy to quickly reduce tumor burden. METHODS: Cell-free DNA (cfDNA) from liquid biopsy was analyzed by next generation sequencing (NGS) using a comprehensive 591-gene panel. Next, a computational method, digital drug-assignment (DDA) was deployed for rapid clinical decision support. RESULTS: NGS analysis identified 38 genetic alterations. DDA identified 6 potential drivers, 24 targets, and 79 MTAs. Everolimus was chosen for first-line therapy based on supporting molecular evidence and the highest DDA ranking among therapies registered in this tumor type. The patient's general condition and liver functions rapidly improved, and CT control revealed partial response in the lymph nodes and stable disease elsewhere. CONCLUSION: Deployment of precision oncology using liquid biopsy, comprehensive molecular profiling, and DDA make personalized first-line therapy of advanced pNET feasible in clinical settings.

A computational method for prioritizing targeted therapies in precision oncology: performance analysis in the SHIVA01 trial.

Precision oncology is currently based on pairing molecularly targeted agents (MTA) to predefined single driver genes or biomarkers. Each tumor harbors a combination of a large number of potential genetic alterations of multiple driver genes in a complex system that limits the potential of this approach. We have developed an artificial intelligence (AI)-assisted computational method, the digital drug-assignment (DDA) system, to prioritize potential MTAs for each cancer patient based on the complex individual molecular profile of their tumor. We analyzed the clinical benefit of the DDA system on the molecular and clinical outcome data of patients treated in the SHIVA01 precision oncology clinical trial with MTAs matched to individual genetic alterations or biomarkers of their tumor. We found that the DDA score assigned to MTAs was significantly higher in patients experiencing disease control than in patients with progressive disease (1523 versus 580, P = 0.037). The median PFS was also significantly longer in patients receiving MTAs with high (1000+ <) than with low (<0) DDA scores (3.95 versus 1.95 months, P = 0.044). Our results indicate that AI-based systems, like DDA, are promising new tools for oncologists to improve the clinical benefit of precision oncology.

Efficacy of Incremental Next-Generation ALK Inhibitor Treatment in Oncogene-Addicted, ALK-Positive, TP53-Mutant NSCLC.

BACKGROUND: The anaplastic lymphoma kinase (ALK) gene fusion rearrangement is a potent oncogene, accounting for 2-7% of lung adenocarcinomas, with higher incidence (17-20%) in non-smokers. ALK-positive tumors are sensitive to ALK tyrosine kinase inhibitors (TKIs), thus ALK-positive non-small-cell lung cancer (NSCLC) is currently spearheading precision medicine in thoracic oncology, with three generations of approved ALK inhibitors in clinical practice. However, these treatments are eventually met with resistance. At the molecular level, ALK-positive NSCLC is of the lowest tumor mutational burden, which possibly accounts for the high initial response to TKIs. Nevertheless, TP53 co-mutations are relatively frequent and are associated with adverse outcome of crizotinib treatment, whereas utility of next-generation ALK inhibitors in TP53-mutant tumors is still unknown. METHODS: We report the case of an ALK-positive, TP53-mutant NSCLC patient with about five years survival on ALK TKIs with continued next-generation regimens upon progression. RESULTS: The tumor showed progression on crizotinib, but long tumor control was achieved following the incremental administration of next-generation ALK inhibitors, despite lack of evident resistance mechanisms. CONCLUSION: TP53 status should be taken into consideration when selecting ALK-inhibitor treatment for personalized therapies. In TP53-mutant tumors, switching TKI generations may overcome treatment exhaustion even in the absence of ALK-dependent resistance mechanisms.

Systematic Review on Characteristics and Reporting Quality of Animal Studies in Liver Regeneration Triggered by Portal Vein Occlusion and Associating Liver Partition and Portal Vein Ligation for Staged Hepatectomy: Adherence to the ARRIVE Guidelines.

BACKGROUND: Portal vein occlusion and associating liver partition and portal vein ligation for staged hepatectomy techniques are in the spotlight of oncological liver surgery. Research involving animal models is indispensable to study the mechanisms of liver regeneration. Inaccurate reporting acts as a significant barrier during the correct interpretation of preclinical findings. Hence, we performed a systematic review to evaluate the status quo of the reporting standards and to assess the potential factors influencing reporting in animal studies, which are focusing on portal vein occlusion and/or associating liver partition and portal vein ligation for staged hepatectomy techniques. MATERIALS AND METHODS: A systematic review was performed in the PubMed and Ovid MEDLINE databases. Baseline study characteristics were recorded, and quality assessment was performed using the Animals in Research: Reporting in vivo Experiments (ARRIVE) checklist. RESULTS: A total of 107 research articles were included for the comprehensive assessment. In the subgroup analysis, newer reports and studies from the post-ARRIVE era, and reports from Europe were all associated with significantly higher ARRIVE scores (P < 0.05). Univariable regression analysis confirmed these factors as predictors of higher reporting quality. However, in the multivariable analysis, only publishing in the post-ARRIVE era has been found as single independent predictor of higher reporting standards (P = 0.028 post-ARRIVE total score 75th percentile; P = 0.000 post-ARRIVE total score median). CONCLUSIONS: Although an improving trend has been observed in reporting quality over the past years, this effect was clearly insufficient. Our results emphasize the need for further measures to improve the methodical quality at all levels of planning, execution, and reporting of preclinical studies in liver regeneration research.

Liver regeneration after different degrees of portal vein ligation.

BACKGROUND: Selective portal vein ligation (PVL) is followed by ipsilateral atrophy and contralateral hypertrophy of the liver lobes. Although the atrophy-hypertrophy complex induced by PVL is a well-documented phenomenon, the effect of different degrees of extended portal vein occlusion on liver regeneration is not known. The aim of this study was to assess the effects of different degrees of portal occlusion on portal pressure and liver regeneration. MATERIALS AND METHODS: Male Wistar rats (n = 96; 220-250 g) were randomized into three groups and underwent 70%, 80%, or 90% portal vein ligation, respectively. The portal pressure was measured immediately and 24, 48, 72, 120, and 168 h after PVL (n = 6/group/time point). The hepatic lobes and the spleen were weighed, and liver regeneration ratio was calculated. Changes in liver histology and the mitotic activity were assessed on hematoxylin-eosin stained slides. RESULTS: Higher degree of portal occlusion triggered a stronger regenerative response (regeneration ratio of PVL 70%168h = 2.23 ± 0.13, PVL 80%168h = 3.11 ± 0.37, PVL 90%168h = 4.68 ± 0.48) PVL led to an immediate increase in portal pressure, the value of which changed proportionally to the mass of liver tissue deprived of portal perfusion (PVL 70%acute = 17 ± 2 mm Hg, PVL 80%acute = 19 ± 1 mm Hg, PVL 90%acute = 26 ± 4 mm Hg). Findings in histology showed necro-apoptotic lesions in the atrophic liver lobes and increased mitotic cell count in the hypertrophic lobes. The mitotic cell count of PVL 90% peaked earlier and at a significantly higher value than of PVL 70% and PVL 80% (PVL 9024h%: 96.0 ± 3.5 PVL 70%48h: 64.0 ± 2.1, PVL 80%48h: 56.3 ± 4.0). The mitotic index after 24 h showed a strong correlation with the acute portal hypertension. CONCLUSIONS: A higher degree of portal vein occlusion leads to a greater regenerative response, presumably triggered by the proportional increase in portal pressure, which supports the role of the so-called "blood-flow" theory of PVL-triggered liver regeneration.

Effect of platelet-rich plasma on the healing of intrabony defects treated with Beta tricalcium phosphate and expanded polytetrafluoroethylene membranes.

BACKGROUND: Regenerative periodontal therapy using platelet-rich plasma (PRP) and different types of bone substitutes with or without guided tissue regeneration (GTR) has been proposed as a modality to enhance the outcome of regenerative surgery. However, there are limited data from controlled clinical studies evaluating the effect of PRP on the healing of deep intrabony defects treated with a combination of bone substitutes and GTR. The aim of this study was to clinically evaluate the effect of PRP on the healing of deep intrabony defects treated with beta tricalcium phosphate (beta-TCP) and GTR by means of a non-bioresorbable expanded polytetrafluoroethylene membrane. METHODS: Twenty-eight subjects with advanced chronic periodontal disease and displaying one intrabony defect were treated randomly with a combination of PRP + beta-TCP + GTR or beta-TCP + GTR. Plaque index, gingival index, bleeding on probing, probing depth (PD), gingival recession, and clinical attachment level (CAL) were evaluated at baseline and at 1 year after treatment. CAL was the primary outcome variable. RESULTS: No differences in any of the investigated parameters were observed at baseline between the two groups. Healing was uneventful in all subjects. At 1 year after therapy, the sites treated with PRP + beta-TCP + GTR showed a reduction in mean PD from 9.1 +/- 0.6 mm to 3.3 +/- 0.5 mm (P <0.001) and a change in mean CAL from 10.1 +/- 1.3 mm to 5.7 +/- 1.1 mm (P <0.001). In the group treated with beta-TCP + GTR, mean PD was reduced from 9.0 +/- 0.8 mm to 3.6 +/- 0.9 mm (P <0.001), and the mean CAL changed from 9.9 +/- 1.0 mm to 5.9 +/- 1.2 mm (P <0.001). In both groups, all sites gained > or =3 mm of CAL. CAL gains > or =4 mm were noted in 86% (12 of 14 defects) of the cases treated with PRP + beta-TCP + GTR and in 79% (11 of 14 defects) of those treated with beta-TCP + GTR. No statistically significant differences in any of the investigated parameters were observed between the two groups at the 1-year reevaluation. CONCLUSION: At 1 year after surgery, both therapies resulted in significant PD reductions and CAL gains.

[The incidence of local plaque retentive factors in chronic periodontitis]. / Lokális plakkretenciós tényezok elofordulási gyakorisága krónikus parodontitisben.

One of the leading local risk factors for chronic periodontitis is the presence of plaque retentive factors in the oral cavity. The main objective of the study was to assess how the local irritation and plaque retention caused by untreated carious lesions, subgingival and approximal overhanging crown margins can affect the attachment loss at patients with chronic periodontitis. The incidence of plaque retentive factors were evaluated on 200 panoramic radiographs randomly selected from the archive of the Department of Periodontology. On the radiographs each fully erupted tooth were studied under magnifying glasses (1:2 magnification), and the distance between CEJ and the most coronal bone level was measured with a ruler with mm scales. The quality of restorations were evaluated based on the approximal adaptation of their margins. During the clinical examination the presence of local plaque retentive factors were registered by tooth, and the radiological alveolar bone level were recorded around both the healthy and restored or filled teeth. Statistical analyzes were made with linear regression analysis and ANOVA. Only 177 out of the randomly selected 200 radiographs met the incursion criteria and could be evaluated. The average age of patients was 49.98 years and the average approximal bone loss was 5.439 mm, showing increasing tendency with age. The 177 patients had a total of 3618 teeth and 1407 teeth presented plaque retentive factors including 164 untreated approximal carious lesions, and 1243 faulty restorations with approximal overhangs or open margins. Radiographically 82.5% of the restorations had incorrect approximal marginal adaptation. The majority of the untreated carious lesions occurred in the molar as well as in the front regions. The average bone loss at the teeth with faulty restorations were higher than at the sound teeth. 113 patients had an average bone loss higher than >4 mm. In those patients the differences between sound and restored teeth were smaller than those in the groups of patients with mild bone loss. Nevertheless neither group showed statistically significant differences between restored and sound teeth. In mild to moderate periodontitis local plaque retentive factors, overhanging crown margins or carious lesions are decisive aggregating factors both in gingivitis and periodontitis, especially in the susceptible population. In severe periodontitis according to our data there were only minimal differences between the attachment level around sound teeth and teeth with faulty restorations and local plaque retentive factors.