GLA-modified RNA treatment lowers GB3 levels in iPSC-derived cardiomyocytes from Fabry-affected individuals.

Recent studies in non-human model systems have shown therapeutic potential of nucleoside-modified messenger RNA (modRNA) treatments for lysosomal storage diseases. Here, we assessed the efficacy of a modRNA treatment to restore the expression of the galactosidase alpha (GLA), which codes for α-Galactosidase A (α-GAL) enzyme, in a human cardiac model generated from induced pluripotent stem cells (iPSCs) derived from two individuals with Fabry disease. Consistent with the clinical phenotype, cardiomyocytes from iPSCs derived from Fabry-affected individuals showed accumulation of the glycosphingolipid Globotriaosylceramide (GB3), which is an α-galactosidase substrate. Furthermore, the Fabry cardiomyocytes displayed significant upregulation of lysosomal-associated proteins. Upon GLA modRNA treatment, a subset of lysosomal proteins were partially restored to wild-type levels, implying the rescue of the molecular phenotype associated with the Fabry genotype. Importantly, a significant reduction of GB3 levels was observed in GLA modRNA-treated cardiomyocytes, demonstrating that α-GAL enzymatic activity was restored. Together, our results validate the utility of iPSC-derived cardiomyocytes from affected individuals as a model to study disease processes in Fabry disease and the therapeutic potential of GLA modRNA treatment to reduce GB3 accumulation in the heart.

Messenger RNA rescues medium-chain acyl-CoA dehydrogenase deficiency in fibroblasts from patients and a murine model.

Medium-chain acyl-CoA dehydrogenase (MCAD) deficiency is the most common inherited disorder of mitochondrial fatty acid ß-oxidation (FAO) in humans. Patients exhibit clinical episodes often associated with fasting. Symptoms include hypoketotic hypoglycemia and Reye-like episodes. With limited treatment options, we explored the use of human MCAD (hMCAD) mRNA in fibroblasts from patients with MCAD deficiency to provide functional MCAD protein and reverse the metabolic block. Transfection of hMCAD mRNA into MCAD- deficient patient cells resulted in an increased MCAD protein that localized to mitochondria, concomitant with increased enzyme activity in cell extracts. The therapeutic hMCAD mRNA-lipid nanoparticle (LNP) formulation was also tested in vivo in Acadm-/- mice. Administration of multiple intravenous doses of the hMCAD mRNA-LNP complex (LNP-MCAD) into Acadm-/- mice produced a significant level of MCAD protein with increased enzyme activity in liver, heart and skeletal muscle homogenates. Treated Acadm-/- mice were more resistant to cold stress and had decreased plasma levels of medium-chain acylcarnitines compared to untreated animals. Furthermore, hepatic steatosis in the liver from treated Acadm-/- mice was reduced compared to untreated ones. Results from this study support the potential therapeutic value of hMCAD mRNA-LNP complex treatment for MCAD deficiency.

Chemical conversion of human conventional PSCs to TSCs following transient naive gene activation.

In human embryos, naive pluripotent cells of the inner cell mass (ICM) generate epiblast, primitive endoderm and trophectoderm (TE) lineages, whence trophoblast cells derive. In vitro, naive pluripotent stem cells (PSCs) retain this potential and efficiently generate trophoblast stem cells (TSCs), while conventional PSCs form TSCs at low efficiency. Transient histone deacetylase and MEK inhibition combined with LIF stimulation is used to chemically reset conventional to naive PSCs. Here, we report that chemical resetting induces the expression of both naive and TSC markers and of placental imprinted genes. A modified chemical resetting protocol allows for the fast and efficient conversion of conventional PSCs into TSCs, entailing shutdown of pluripotency genes and full activation of the trophoblast master regulators, without induction of amnion markers. Chemical resetting generates a plastic intermediate state, characterised by co-expression of naive and TSC markers, after which cells steer towards one of the two fates in response to the signalling environment. The efficiency and rapidity of our system will be useful to study cell fate transitions and to generate models of placental disorders.

Stress-Dependent Optical Extinction in Low-Pressure Chemical Vapor Deposition Silicon Nitride Measured by Nanomechanical Photothermal Sensing.

Understanding optical absorption in silicon nitride is crucial for cutting-edge technologies like photonic integrated circuits, nanomechanical photothermal infrared sensing and spectroscopy, and cavity optomechanics. Yet, the origin of its strong dependence on the film deposition and fabrication process is not fully understood. This Letter leverages nanomechanical photothermal sensing to investigate optical extinction κext at a 632.8 nm wavelength in low-pressure chemical vapor deposition (LPCVD) SiN strings across a wide range of deposition-related tensile stresses (200-850 MPa). Measurements reveal a reduction in κext from 103 to 101 ppm with increasing stress, correlated to variations in Si/N content ratio. Within the band-fluctuations framework, this trend indicates an increase of the energy bandgap with the stress, ultimately reducing absorption. Overall, this study showcases the power and simplicity of nanomechanical photothermal sensing for low absorption measurements, offering a sensitive, scattering-free platform for material analysis in nanophotonics and nanomechanics.

Improved therapeutic efficacy in two mouse models of methylmalonic acidemia (MMA) using a second-generation mRNA therapy.

Isolated methylmalonic acidemia/aciduria (MMA) due to MMUT enzyme deficiency is an ultra-rare pediatric disease with high morbidity and mortality, with no approved disease-altering therapies. Previous publications showed that systemic treatment with a codon-optimized mRNA encoding wild-type human MMUT (MMUT) is a promising strategy for treatment of MMA. We developed a second-generation drug product, mRNA-3705, comprised of an mRNA encoding the MMUT enzyme formulated in a lipid nanoparticle (LNP) with incorporation of enhancements over the previous clinical candidate mRNA-3704. Both drug products produced functional MMUT in rat livers when dosed IV, and showed long-term safety and efficacy in two mouse models of MMA. mRNA-3705 produced 2.1-3.4-fold higher levels of hepatic MMUT protein expression than the first-generation drug product mRNA-3704 when given at an identical dose level, which resulted in greater and more sustained reductions in plasma methylmalonic acid. The data presented herein provide comprehensive preclinical pharmacology to support the clinical development of mRNA-3705.

Non-mitogenic FGF19 mRNA-based therapy for the treatment of experimental metabolic dysfunction-associated steatotic liver disease (MASLD).

Metabolic dysfunction-associated steatohepatitis (MASH), represents a global health threat. MASH pathophysiology involves hepatic lipid accumulation and progression to severe conditions like cirrhosis and, eventually, hepatocellular carcinoma. Fibroblast growth factor (FGF)-19 has emerged as a key regulator of metabolism, offering potential therapeutic avenues for MASH and associated disorders. We evaluated the therapeutic potential of non-mitogenic (NM)-FGF19 mRNA formulated in liver-targeted lipid nanoparticles (NM-FGF19-mRNAs-LNPs) in C57BL/6NTac male mice with diet-induced obesity and MASH (DIO-MASH: 40% kcal fat, 20% kcal fructose, 2% cholesterol).  After feeding this diet for 21 weeks, NM-FGF19-mRNAs-LNPs or control (C-mRNA-LNPs) were administered (0.5 mg/kg, i.v.) weekly for another six weeks, in which diet feeding continued. NM-FGF19-mRNAs-LNPs treatment in DIO-MASH mice resulted in reduced body weight, adipose tissue depots, and serum transaminases, along with improved insulin sensitivity. Histological analyses confirmed the reversal of MASH features, including steatosis reduction without worsening fibrosis. NM-FGF19-mRNAs-LNPs reduced total hepatic bile acids (BA) and changed liver BA composition, markedly influencing cholesterol homeostasis and metabolic pathways as observed in transcriptomic analyses. Extrahepatic effects included the downregulation of metabolic dysfunction-associated genes in adipose tissue. This study highlights the potential of NM-FGF19-mRNA-LNPs therapy for MASH, addressing both hepatic and systemic metabolic dysregulation. NM-FGF19-mRNA demonstrates efficacy in reducing liver steatosis, improving metabolic parameters, and modulating BA levels and composition. Given the central role played by BA in dietary fat absorption, this effect of NM-FGF19-mRNA may be mechanistically relevant. Our study underscores the high translational potential of mRNA-based therapies in addressing the multifaceted landscape of MASH and associated metabolic perturbations.

Abdominal drainage after minimally invasive distal pancreatectomy: out of sight, out of mind?

BACKGROUNDS: The use of drains in pancreatic surgery remains controversial. The present study investigated postoperative outcomes in patients undergoing minimally invasive distal pancreatectomy (MIDP) without intraperitoneal drain placement. METHODS: Data of consecutive patients undergoing MIDP between 2013 and 2023 were prospectively collected. Patients were divided in drain group (DG), including patients with prophylactic abdominal drain placed, and no-drain group (NDG) including those without drain. The groups were compared in terms of postoperative outcomes, using a propensity score-matched analysis. RESULTS: 116 patients were selected. After matching, DG and NDG consisted of 29 patients each. The rates of POPF and abdominal collection were lower in NDG in comparison to DG (3.4% vs. 27.6%, p 0.025 and 3.4% vs. 31.0%, p 0.011, respectively). The length of stay was significantly shorter in the NDG (5 vs. 9 days, p < 0.001). No difference between the groups was found for other outcomes. CONCLUSION: Drain omission was associated with lower rates of POPF and abdominal collections, as well as shorter hospital stays, not affecting the rate of severe complication, reoperation and readmission.

Clinical outcomes and survival rates of a uncemented modular revision stem system in hip arthroplasty: a 10-year single-institution study on a frail population.

INTRODUCTION: The increasing prevalence of primary hip arthroplasty has led to a parallel rise in revision cases. Femoral revision often entails compromised bone integrity, requiring consideration of various solutions for optimal reconstructive options. Despite technological advancements, there is limited evidence on the clinical outcomes of the latest modular revision stems. This study aimed to evaluate the clinical outcomes and survival rates of next generation uncemented modular revision stem in patients undergoing hip revision surgery. MATERIALS AND METHODS: This retrospective single-center study assessed the survival and failure causes of a specific uncemented modular stem in 48 patients undergoing hip revision surgery between 2012 and 2022. Data included preoperative parameters, surgical details, and postoperative outcomes measured through clinical and radiographic assessments. Forty-eight patients (25 males, 23 females; mean age 72 years) were included, with a mean Charlson Comorbidity Index of 5. Preoperative diagnoses varied, with periprosthetic joint infection (PJI) being the most common (45.8%), followed by periprosthetic fractures (27.1%). Partial revisions occurred in 60.4%, total revisions in 39.6%. According to Paprosky classification of femoral bone loss, type II and III were the most represented, respectively 35.4% and 50%. RESULTS: At a mean follow-up of 4.6 years, stem survival was 92.5%. Complications (20%) included dislocation, PJI, fracture, and loosening; the overall reoperation rate was 12.5%. The SF-12 physical score was 43.6, while the mental score was 51.1. The HOOS score was 71.8, and the HHS score was 71.4. Radiographic analysis identified nonprogressive osteolysis in 15.1% of patients. CONCLUSIONS: This study on this uncemented modular revision stem demonstrated favorable outcomes in an elder fragile population with moderate to severe femoral bone loss. The implant's modularity provides versatility in addressing various defects, without any implant breakage observed during the study period. Literature comparison highlighted similar outcomes despite sample size differences. The promising results warrant continued investigation into the long-term survivorship of this modular stem system.

A comprehensive investigation of histotype-specific microRNA and their variants in Stage I epithelial ovarian cancers.

isomiRs, the sequence-variants of microRNA, are known to be tissue and cell type specific but their physiological role is largely unknown. In our study, we explored for the first time the expression of isomiRs across different Stage I epithelial ovarian cancer (EOC) histological subtypes, in order to shed new light on their biological role in tumor growth and progression. In a multicentric retrospective cohort of tumor biopsies (n = 215) we sequenced small RNAs finding 971 expressed miRNAs, 64% of which are isomiRs. Among them, 42 isomiRs showed a clear histotype specific pattern, confirming our previously identified miRNA markers (miR192/194 and miR30a-3p/5p for mucinous and clear cell subtypes, respectively) and uncovering new biomarkers for all the five subtypes. Using integrative models, we found that the 38% of these miRNA expression alterations is the result of copy number variations while the 17% of differential transcriptional activities. Our work represents the first attempt to characterize isomiRs expression in Stage I EOC within and across subtypes and to contextualize their alterations in the framework of the large genomic heterogeneity of this tumor.

Synthetic mRNA rescues very long-chain acyl-CoA dehydrogenase deficiency in patient fibroblasts and a murine model.

Very long-chain acyl-CoA dehydrogenase (VLCAD) deficiency is an inborn error of long chain fatty acid ß-oxidation (FAO) with limited treatment options. Patients present with heterogeneous clinical phenotypes affecting predominantly heart, liver, and skeletal muscle. While VLCAD deficiency is a systemic disease, restoration of liver FAO has the potential to improve symptoms more broadly due to increased total body ATP production and reduced accumulation of potentially toxic metabolites. We explored the use of synthetic human VLCAD (hVLCAD) mRNA and lipid nanoparticle encapsulated hVLCAD mRNA (LNP-VLCAD) to generate functional VLCAD enzyme in patient fibroblasts derived from VLCAD deficient patients, mouse embryonic fibroblasts, hepatocytes isolated from VLCAD knockout (Acadvl-/-) mice, and Acadvl-/- mice to reverse the metabolic effects of the deficiency. Transfection of all cell types with hVLCAD mRNA resulted in high level expression of protein that localized to mitochondria with increased enzyme activity. Intravenous administration of LNP-VLCAD to Acadvl-/- mice produced a significant amount of VLCAD protein in liver, which declined over a week. Treated Acadvl-/- mice showed reduced hepatic steatosis, were more resistant to cold stress, and accumulated less toxic metabolites in blood than untreated animals. Results from this study support the potential for hVLCAD mRNA for treatment of VLCAD deficiency.

Amnio acid substitution at position 298 of human glucose-6 phosphatase-α significantly impacts its stability in mammalian cells.

Glucose-6-phosphatase-α (G6Pase-α) catalyzes the hydrolysis of glucose-6-phosphate to glucose and functions as a key regulator in maintaining blood glucose homeostasis. Deficiency in G6Pase-α causes glycogen storage disease 1a (GSD1a), an inherited disorder characterized by life-threatening hypoglycemia and other long-term complications. We have developed a potential mRNA-based therapy for GSD1a and demonstrated that a human G6Pase-α (hG6Pase-α) variant harboring a single serine (S) to cysteine (C) substitution at the amino acid site 298 (S298C) had > twofold increase in protein expression, resulting in improved in vivo efficacy. Here, we sought to investigate the mechanisms contributing to the increased expression of the S298C variant. Mutagenesis of hG6Pase-α identified distinct protein variants at the 298 amino acid position with substantial reduction in protein expression in cultured cells. Kinetic analysis of expression and subcellular localization in mammalian cells, combined with cell-free in vitro translation assays, revealed that altered protein expression stemmed from differences in cellular protein stability rather than biosynthetic rates. Site-specific mutagenesis studies targeting other cysteines of the hG6Pase-α S298C variant suggest the observed improvements in stability are not due to additional disulfide bond formation. The glycosylation at Asparagine (N)-96 is critical in maintaining enzymatic activity and mutations at position 298 mainly affected glycosylated forms of hG6Pase-α. Finally, proteasome inhibition by lactacystin improved expression levels of unstable hG6Pase-α variants. Taken together, these data uncover a critical role for a single amino acid substitution impacting the stability of G6Pase-α and provide insights into the molecular genetics of GSD1a and protein engineering for therapeutic development.

The incidence of movement disorder increases with age and contrasts with subtle and limited neuroimaging abnormalities in argininosuccinic aciduria.

Argininosuccinate lyase (ASL) is integral to the urea cycle detoxifying neurotoxic ammonia and the nitric oxide (NO) biosynthesis cycle. Inherited ASL deficiency causes argininosuccinic aciduria (ASA), a rare disease with hyperammonemia and NO deficiency. Patients present with developmental delay, epilepsy and movement disorder, associated with NO-mediated downregulation of central catecholamine biosynthesis. A neurodegenerative phenotype has been proposed in ASA. To better characterise this neurodegenerative phenotype in ASA, we conducted a retrospective study in six paediatric and adult metabolic centres in the UK in 2022. We identified 60 patients and specifically looked for neurodegeneration-related symptoms: movement disorder such as ataxia, tremor and dystonia, hypotonia/fatigue and abnormal behaviour. We analysed neuroimaging with diffusion tensor imaging (DTI) magnetic resonance imaging (MRI) in an individual with ASA with movement disorders. We assessed conventional and DTI MRI alongside single photon emission computer tomography (SPECT) with dopamine analogue radionuclide 123 I-ioflupane, in Asl-deficient mice treated by hASL mRNA with normalised ureagenesis. Movement disorders in ASA appear in the second and third decades of life, becoming more prevalent with ageing and independent from the age of onset of hyperammonemia. Neuroimaging can show abnormal DTI features affecting both grey and white matter, preferentially basal ganglia. ASA mouse model with normalised ureagenesis did not recapitulate these DTI findings and showed normal 123 I-ioflupane SPECT and cerebral dopamine metabolomics. Altogether these findings support the pathophysiology of a late-onset movement disorder with cell-autonomous functional central catecholamine dysregulation but without or limited neurodegeneration of dopaminergic neurons, making these symptoms amenable to targeted therapy.

Standardized right artery first approach during laparoscopic pancreaticoduodenectomy for periampullary neoplasms: technical aspects and perioperative outcomes.

BACKGROUND: The most debated aspects of laparoscopic pancreaticoduodenectomy (LPD) concern the dissection of the pancreas from the surrounding vessels and the achievement of adequate resection margins, especially in patients with pancreatic cancer. METHODS: Data of consecutive patients undergoing LPD with right artery first approach from September 2020 to September 2021 for periampullary neoplasms (pancreatic, ampullary, duodenal, distal common biliary duct) were prospectively collected and retrospectively analyzed. The overall cohort was divided into two groups: patients affected by pancreatic carcinoma (PC) and patients affected by other periampullary neoplasms (OP). Surgical and postoperative outcomes between PC and OP were compared. RESULTS: Thirty-one patients (15 PC and 16 OP) were selected. No difference was found between PC and OP in terms of baseline characteristics. Median resection time and overall surgical time of the entire cohort were 275 min and 530 min, respectively, without difference between the groups (p = 0.599 and 0.052, respectively). Blood loss was similar between the groups, being 350 ml in PC and 325 ml in OP (p = 0.762). One patient (3.2%) was converted to laparotomy. No difference was found between the groups in terms of pathological outcomes. Median number of retrieved lymph nodes was 17. The majority of the patients (83.9%) received an R0 resection (73.3% and 93.7% in PC and OP, respectively; p = 0.172). Postoperative surgical outcomes did not differ between the groups, excepting for overall complication rate that was higher in the OP group (26.7% vs 68.7% in PC and OP, respectively; p = 0.032). CONCLUSION: Standardized right artery first approach during LPD was feasible and did not show worse surgical and postoperative outcomes in patients with pancreatic cancer as compared to those affected by other periampullary neoplasms, except for a higher rate of minor complications.

Multidimensional evaluation of the learning curve for totally laparoscopic pancreaticoduodenectomy: a risk-adjusted cumulative summation analysis.

INTRODUCTION: Laparoscopic pancreaticoduodenectomy (LPD) is a challenging procedure. We investigated the learning curve (LC) for LPD with a multidimensional analysis. METHODS: Data of patients undergoing LPD between 2017 and 2021, operated by a single surgeon, were considered. A multidimensional assessment of the LC was performed through Cumulative Sum (CUSUM) and Risk-Adjusted (RA)-CUSUM analysis. RESULTS: 113 patients were selected. Rates of conversion, overall postoperative complication, severe complication and mortality were 4%, 53%, 29% and 4%, respectively. RA-CUSUM analysis showed a LC with three phases: competency (procedures 1-51), proficiency (procedures 52-94), and mastery (after procedure 94). Operative time was lower in both phase two (588.17 vs 541.13 min, p = 0.001) and three (534.72 vs 541.13 min, p = 0.004) with respect to phase one. Severe complication rate was lower in mastery as compared to competency phase (42% vs 6%, p = 0.005). During mastery phase a greater number of lymph nodes was harvested in comparison to proficiency phase. CONCLUSIONS: According to our LC analysis, 52 procedures were required to achieve technical competency in LPD. Mastery, which corresponded to a reduction in operative time and surgical failures, was acquired after 94 procedures.

Systemic mRNA Therapy for the Treatment of Fabry Disease: Preclinical Studies in Wild-Type Mice, Fabry Mouse Model, and Wild-Type Non-human Primates.

Fabry disease is an X-linked lysosomal storage disease caused by loss of alpha galactosidase A (α-Gal A) activity and is characterized by progressive accumulation of globotriaosylceramide and its analogs in all cells and tissues. Although enzyme replacement therapy (ERT) is considered standard of care, the long-term effects of ERT on renal and cardiac manifestations remain uncertain and thus novel therapies are desirable. We herein report preclinical studies evaluating systemic messenger RNA (mRNA) encoding human α-Gal A in wild-type (WT) mice, α-Gal A-deficient mice, and WT non-human primates (NHPs). The pharmacokinetics and distribution of h-α-Gal A mRNA encoded protein in WT mice demonstrated prolonged half-lives of α-Gal A in tissues and plasma. Single intravenous administration of h-α-Gal A mRNA to Gla-deficient mice showed dose-dependent protein activity and substrate reduction. Moreover, long duration (up to 6 weeks) of substrate reductions in tissues and plasma were observed after a single injection. Furthermore, repeat i.v. administration of h-α-Gal A mRNA showed a sustained pharmacodynamic response and efficacy in Fabry mice model. Lastly, multiple administrations to non-human primates confirmed safety and translatability. Taken together, these studies across species demonstrate preclinical proof-of-concept of systemic mRNA therapy for the treatment of Fabry disease and this approach may be useful for other lysosomal storage disorders.

Novel mRNA therapy restores GALT protein and enzyme activity in a zebrafish model of classic galactosemia.

Messenger RNA (mRNA) has emerged as a novel therapeutic approach for inborn errors of metabolism. Classic galactosemia (CG) is an inborn error of galactose metabolism caused by a severe deficiency of galactose-1-phosphate:uridylyltransferase (GALT) activity leading to neonatal illness and chronic impairments affecting the brain and female gonads. In this proof of concept study, we used our zebrafish model for CG to evaluate the potential of human GALT mRNA (hGALT mRNA) packaged in two different lipid nanoparticles to restore GALT expression and activity at early stages of development. Both one cell-stage and intravenous single-dose injections resulted in hGALT protein expression and enzyme activity in the CG zebrafish (galt knockout) at 5 days post fertilization (dpf). Moreover, the levels of galactose-1-phosphate (Gal-1-P) and galactonate, metabolites that accumulate because of the deficiency, showed a decreasing trend. LNP-packaged mRNA was effectively translated and processed in the CG zebrafish without signs of toxicity. This study shows that mRNA therapy restores GALT protein and enzyme activity in the CG zebrafish model, and that the zebrafish is a suitable system to test this approach. Further studies are warranted to assess whether repeated injections safely mitigate the chronic impairments of this disease.

Laparoscopic gastrectomy for stage II and III advanced gastric cancer: long­term follow­up data from a Western multicenter retrospective study.

INTRODUCTION: There has been an increasing interest for the laparoscopic treatment of early gastric cancer, especially among Eastern surgeons. However, the oncological effectiveness of Laparoscopic Gastrectomy (LG) for Advanced Gastric Cancer (AGC) remains a subject of debate, especially in Western countries where limited reports have been published. The aim of this paper is to retrospectively analyze short- and long-term results of LG for AGC in a real-life Western practice. MATERIALS AND METHODS: All consecutive cases of LG with D2 lymphadenectomy for AGC performed from January 2005 to December 2019 at seven different surgical departments were analyzed retrospectively. The primary outcome was diseases-free survival (DFS). Secondary outcomes were overall survival (OS), number of retrieved lymph nodes, postoperative morbidity and conversion rate. RESULTS: A total of 366 patients with stage II and III AGC underwent either total or subtotal LG. The mean number of harvested lymph nodes was 25 ± 14. The mean hospital stay was 13 ± 10 days and overall postoperative morbidity rate 27.32%, with severe complications (grade ≥ III) accounting for 9.29%. The median follow-up was 36 ± 16 months during which 90 deaths occurred, all due to disease progression. The DFS and OS probability was equal to 0.85 (95% CI 0.81-0.89) and 0.94 (95% CI 0.92-0.97) at 1 year, 0.62 (95% CI 0.55-0.69) and 0.63 (95% CI 0.56-0.71) at 5 years, respectively. CONCLUSION: Our study has led us to conclude that LG for AGC is feasible and safe in the general practice of Western institutions when performed by trained surgeons.

Is routine CT scan after pancreaticoduodenectomy a useful tool in the early detection of complications? A single center retrospective analysis.

PURPOSE: The clinical impact of routine CT imaging after pancreaticoduodenectomy (PD) has not been properly investigated. The aim of this study was to investigate the role of routine CT scan after PD for the detection of postoperative complications. METHODS: Prospectively collected data of consecutive patients undergoing PD and receiving routine postoperative CT imaging were retrospectively analyzed. The primary endpoint was accuracy of CT imaging in identifying major complications. The secondary endpoint was identification of preoperative and intraoperative factors associated with severe complications. A subgroup analysis of CT scan accuracy in identifying severe complications in patients stratified by fistula risk score (FRS) and presence of early clinical alterations was also performed. RESULTS: A total of 145 patients were included. Routine CT scan had low specificity (Sp = 0.36) and high sensitivity (Sn = 0.98) for predicting major complications, with an accuracy of 0.57. At multivariate logistic regression analysis, only fistula moderate-high FRS (p = 0.029) was independently associated with severe complications. In patients with negligible-low FRS, CT scan showed a Sp of 0.63 and a Sn of 1.0 with an accuracy of 0.69. In patients with moderate-high FRS, CT scan had a Sp of 0.19, a Sn of 0.97 and an accuracy of 0.5. In the 20 (14%) patients with negligible-low FRS and no clinical alterations, no deaths or readmissions occurred regardless of CT findings, while one severe complication occurred in the positive CT scan group. In all other groups, no deaths or readmissions occurred in case of negative CT, with only one severe complication in the moderate-high FRS group with clinical alterations. In case of positive CT, the rate of severe complications was 47% in case of negligible-low FRS and clinical alterations, 40% in case of moderate-high FRS with no clinical alterations, and 45% in case of moderate-high FRS and clinical alterations. CONCLUSIONS: Routine postoperative CT scan after PD should not be performed in patients with negligible-low FRS and no clinical alterations. In all other patients, a negative CT scan appears to be highly accurate in identifying patients who will have an uneventful course and who could benefit from early discharge.

Lipid nanoparticle-targeted mRNA therapy as a treatment for the inherited metabolic liver disorder arginase deficiency.

Arginase deficiency is caused by biallelic mutations in arginase 1 (ARG1), the final step of the urea cycle, and results biochemically in hyperargininemia and the presence of guanidino compounds, while it is clinically notable for developmental delays, spastic diplegia, psychomotor function loss, and (uncommonly) death. There is currently no completely effective medical treatment available. While preclinical strategies have been demonstrated, disadvantages with viral-based episomal-expressing gene therapy vectors include the risk of insertional mutagenesis and limited efficacy due to hepatocellular division. Recent advances in messenger RNA (mRNA) codon optimization, synthesis, and encapsulation within biodegradable liver-targeted lipid nanoparticles (LNPs) have potentially enabled a new generation of safer, albeit temporary, treatments to restore liver metabolic function in patients with urea cycle disorders, including ARG1 deficiency. In this study, we applied such technologies to successfully treat an ARG1-deficient murine model. Mice were administered LNPs encapsulating human codon-optimized ARG1 mRNA every 3 d. Mice demonstrated 100% survival with no signs of hyperammonemia or weight loss to beyond 11 wk, compared with controls that perished by day 22. Plasma ammonia, arginine, and glutamine demonstrated good control without elevation of guanidinoacetic acid, a guanidino compound. Evidence of urea cycle activity restoration was demonstrated by the ability to fully metabolize an ammonium challenge and by achieving near-normal ureagenesis; liver arginase activity achieved 54% of wild type. Biochemical and microscopic data showed no evidence of hepatotoxicity. These results suggest that delivery of ARG1 mRNA by liver-targeted nanoparticles may be a viable gene-based therapeutic for the treatment of arginase deficiency.

Novel biodegradable internal stent as a mitigation strategy in high-risk pancreaticojejunostomy: technical notes and preliminary results.

Clinically relevant postoperative pancreatic fistula (CR-POPF) is the most feared complication after pancreaticoduodenectomy (PD), as it can lead to extremely poor outcomes. We herein report the preliminary results of an anastomotic technique based on the use of a novel internal biodegradable stent (IBS) to mitigate POPF sequelae. Between October 2020 and May 2021, all patients undergoing PD with high-risk pancreatic anastomosis received a pancreato-jejunal (PJ) anastomosis with an Archimedes™ IBS placement. Fifteen patients comprised our study cohort. In 11 cases, a 2-mm Archimedes™ stent was used, and in the remaining four patients, a 2.6-mm stent was used. Overall postoperative complications occurred in eight patients, with four cases being severe. Two patients developed CR-POPF, with one of them dying. In our small preliminary series, PJ anastomosis with an Archimedes™ IBS showed encouraging results in terms of CR-POPF incidence. Further studies are needed to confirm these findings.