Liver transplantation represents the only curative method for end-stage liver disorders and certain liver malignancies. Over the last three decades, advancements in immunosuppression, surgical technique, and intensive care measures have resulted in improved patient and graft survival outcomes, but a deficit of donor organs is constantly the major issue that limits our ability to reduce the mortality on the liver transplant waiting list. To address this, marginal grafts and those from donors after cardiac death are increasingly employed, but these strategies necessitated novel methods to improve the preservation and quality of liver grafts and the most promising one is liver machine perfusion (LMP). LMP evolved significantly in the past 10 years, and consequently, it is gradually establishing itself as a standard protocol at many transplant centers. However, many unresolved questions remain concerning the indications, types, and protocols associated with LMP. Therefore, continuous research is necessary to determine optimal guidelines and recommendations for its clinical application. This review aims to analyze the development of liver machine perfusion, including its different modalities underlying mechanisms of operation, and provide an overview of its historical evolution, current status, and future prospects.

Liver graft shortage remains a major limiting factor in contemporary liver transplantation, particularly in the setting of increasing waiting list pressure and constrained donor availability. While the biological quality of donor organs cannot be modified surgically, several operative strategies have been developed to optimize liver utilization and compensate for insufficient graft volume. These include split liver transplantation (SLT), dual-graft living donor liver transplantation (DGLT), auxiliary procedures, and selected multi-graft or hybrid configurations. This review provides an updated and structured overview of surgical concepts aimed at maximizing effective liver mass for transplantation. We discuss indications, technical considerations, and reported outcomes of split, dual, and combined graft approaches, with particular emphasis on graft-to-recipient weight ratio (GRWR), portal inflow modulation, and prevention of small-for-size syndrome. The role of machine perfusion technologies—including normothermic and hypothermic approaches—as enabling tools for graft assessment and safer utilization of partial grafts is also examined. Finally, we address ethical and logistical challenges associated with complex graft strategies and outline future directions in which advances in perfusion, graft assessment, and staged transplantation concepts may further refine patient selection and procedural safety. Collectively, these strategies represent complementary solutions for extending liver transplantation beyond conventional single-graft paradigms in highly selected settings.

Background: Acute cholecystitis is one of the most common acute diseases of the biliary system and a frequent reason for emergency hospital admission and surgical treatment. More severe forms are associated with a higher need for intensive care, more frequent use of open surgery, and less favourable outcomes. Age and chronic comorbidity burden may play an important role in determining disease severity. The age-adjusted Charlson Comorbidity Index (CCI-Age) is a simple and widely used tool for integrated assessment of age and comorbidity burden, but its role in acute cholecystitis is not sufficiently defined. Methods: Data for this study were collected by retrospective analysis of hospital records from the hospital information system of the University Hospital Centre Zagreb. Patients treated conservatively were excluded. The association of age and CCI-Age with the severity of the clinical presentation of acute cholecystitis was analysed using dichotomised clinical variables and comparative statistical methods. Results: The results showed that age and the presence of chronic diseases were strongly associated with the severity of the clinical presentation of acute cholecystitis. Older patients and those with a greater burden of chronic comorbidities significantly more often developed more severe forms of the disease. Among chronic diseases, peripheral vascular disease, diabetes mellitus, and chronic renal disease showed the strongest association with more severe clinical presentation. Conclusions: Age and CCI-Age were strongly associated with the severity of the clinical presentation of acute cholecystitis. CCI-Age may represent a useful tool for early clinical risk stratification and support therapeutic decision making in everyday surgical practice.

Understanding interactions between cations and DNA is essential for elucidating the structural dynamics of this fundamental biomolecule. While B-DNA is well known to dominate in long genomic DNA under physiological ionic conditions, its stability in very short DNA fragments—particularly in dilute solutions and in crude oligonucleotide preparations—has remained largely unexplored. Previous spectroscopic studies have primarily focused on long DNA, highly purified oligonucleotides, or high-salt environments, where collective polyion effects dominate. In contrast, the present results demonstrate that even in the absence of chain overlap and under low-salt conditions, Mg²⁺ ions efficiently stabilize the B-form by screening phosphate–phosphate electrostatic repulsion at the intrachain level. The ability to induce an A-to-B transition in crude, ultra-short DNA fragments highlights the fundamental role of divalent counterions in governing DNA conformation and establishes a lower bound for the length scale at which B-DNA can be stabilized. These findings are particularly relevant for dilute biological systems, fragmented DNA samples, and analytical protocols where short DNA fragments and low ionic strength are unavoidable.