Osmotic loading of cells has been used to investigate their physicochemical properties as well as their biosynthetic activities. The classical Kedem–Katchalsky framework for analyzing cell response to osmotic loading, which models the cell as a fluid-filled membrane, does not generally account for the possibility of partial volume recovery in response to loading with a permeating osmolyte, as observed in some experiments. The cell may be more accurately represented as a hydrated gel surrounded by a semi-permeable membrane, with the gel and membrane potentially exhibiting different properties. To help assess whether this more elaborate model of the cell is justified, this study investigates the response of spherical gels to osmotic loading, both from experiments and theory. The spherical gel is described using the framework of mixture theory. In the experimental component of the study alginate is used as the model gel, and is osmotically loaded with dextran solutions of various concentrations and molecular weight, to verify the predictions from the theoretical analysis. Results show that the mixture framework can accurately predict the transient and equilibrium response of alginate gels to osmotic loading with dextran solutions. It is found that the partition coefficient of dextran in alginate regulates the equilibrium volume response and can explain partial volume recovery based on passive transport mechanisms. The validation of this theoretical framework facilitates future investigations of the role of the protoplasm in the response of cells to osmotic loading.

INTRODUCTION: Among children who suffer from acute recurrent pancreatitis (ARP) or chronic pancreatitis (CP), acute pancreatitis (AP) episodes are painful, often require hospitalization, and contribute to disease complications and progression. Despite this recognition, there are currently no interventions to prevent AP episodes. In this retrospective cohort study, we assessed the impact of pancreatic enzyme therapy (PERT) use on clinical outcomes among children with pancreatic-sufficient ARP or CP. METHODS: Children with pancreatic-sufficient ARP or CP in the INSPPIRE-2 cohort were included. Clinical outcomes were compared for those receiving vs not receiving PERT, as well as frequency of AP before and after PERT. Logistic regression was used to study the association between development of AP episodes after starting PERT and response predictors. RESULTS: Among 356 pancreatic-sufficient participants, 270 (76%) had ARP, and 60 (17%) received PERT. Among those on PERT, 42% did not have a subsequent AP episode, during a mean 2.1 years of follow-up. Children with a SPINK1 mutation (P = 0.005) and those with ARP (compared with CP, P = 0.008) were less likely to have an AP episode after starting PERT. After initiation of PERT, the mean AP annual incidence rate decreased from 3.14 down to 0.71 (P < 0.001). DISCUSSION: In a retrospective analysis, use of PERT was associated with a reduction in the incidence rate of AP among children with pancreatic-sufficient ARP or CP. These results support the need for a clinical trial to evaluate the efficacy of PERT to improve clinical outcomes among children with ARP or CP.

Gamma irradiation is a proven sterilization method, but is not widely used on allografts for anterior cruciate ligament reconstruction (e.g., patella tendon) due to radiation-induced decreases in mechanical strength. Addressing this drawback would improve the safety and supply of allografts to meet current and future demand. It was hypothesized that genipin-induced collagen cross-linking would increase the tensile modulus of patella tendon tissue such that 5 MRad gamma irradiation would not reduce the tissue mechanical strength below the original untreated values. Optimized genipin treatment increased the tensile modulus of bovine tendons by ~2.4-fold. After irradiation, genipin treated tissue did not significantly differ from native tissue, proving the hypothesis. Optimized genipin treatment of human tendons increased the tensile modulus by ~1.3-fold. After irradiation, both control and genipin-treated tissues possessed ~50–60% of their native tendon modulus, disproving the hypothesis. These results highlight possible age- and species- dependent effects of genipin cross-linking on tendon tissue. Cross-linking of human allografts may be beneficial only in younger donor tissues. Future research is warranted to better understand the mechanisms and applications of collagen cross-linking for clinical use.

Pediatric MASLD (previously referred to as NAFLD) incidence has continued to rise along with the obesity pandemic. Pediatric MASLD increases the risk of liver fibrosis and cirrhosis in adulthood. Early detection and intervention can prevent and reduce complications. Liver biopsy remains the gold standard for diagnosis, although imaging modalities are increasingly being used. We performed a retrospective study of 202 children seen in a pediatric gastroenterology clinic with a complaint of abdominal pain, elevated liver enzymes or MASLD, or a combination of the three to evaluate screening methods for MASLD. A total of 134 of the 202 patients included in the study underwent laboratory testing and abdominal ultrasound. Ultrasound images were reviewed with attention to liver size and echotexture by a fellowship-trained pediatric radiologist for liver size and echotexture. Overall, 76.2% of the initial radiology reports correctly identified hepatomegaly based on age and 75.4% of the initial radiology reports correctly described hepatic echogenicity that was consistent with increased hepatic fat deposition. Use of screening ultrasound in concert with other clinical evaluations can be helpful to identify children at risk of MASLD. Utilizing ranges for liver span according to age can help to diagnose hepatomegaly, and understanding how to identify hepatic echogenicity is important for identifying possible hepatic steatosis.