Impact of COVID-19 Treatment on Real-World Outcomes in Inflammatory Bowel Disease.

Background: While there are multiple safe and effective agents for COVID-19 treatment, their impact in inflammatory bowel disease (IBD) remains uncertain.

Aims: Our objective was to assess the effects of these therapies on both IBD and COVID outcomes.

Methods: A single-center retrospective study of adult patients with IBD who contracted COVID-19 between 12/2020 and 11/2022 was performed.

Phosphorus bioaccessibility measured in four amino acid-based formulas using in-vitro batch digestion translates well into phosphorus bioavailability in mice.

Objective: The aim of this study was to quantify the bioaccessibility of phosphorus from amino acid-based formulas (AAFs) under different digestive conditions.

Methods: We developed in-vitro batch digestion models with stomach digestion at different pH mimicking the normal digestive condition and conditions representing use of acid-suppressive medication. To validate bioaccessibility findings, we devised a low phosphorus murine model to test phosphorus bioavailability under compromised digestive conditions using proton pump inhibitors (PPIs) to neutralize stomach pH.

Slc20a1/Pit1 and Slc20a2/Pit2 are essential for normal skeletal myofiber function and survival.

Low blood phosphate (Pi) reduces muscle function in hypophosphatemic disorders. Which Pi transporters are required and whether hormonal changes due to hypophosphatemia contribute to muscle function is unknown. To address these questions we generated a series of conditional knockout mice lacking one or both house-keeping Pi transporters Pit1 and Pit2 in skeletal muscle (sm), using the postnatally expressed human skeletal actin-cre.

Transgenic mouse model for conditional expression of influenza hemagglutinin-tagged human SLC20A1/PIT1.

To further investigate the role of the phosphate (Pi) transporter PIT1 in Pi homeostasis and tissue mineralization, we developed a transgenic mouse expressing the C-terminal influenza hemagglutinin (HA) epitope-tagged human PIT1 transporter under control of the cytomegalovirus/chicken beta actin/rabbit beta-globin gene (CAG) promotor and a loxP-stop-loxP (LSL) cassette permitting conditional activation of transgene expression (LSL-HA-hPITtg/+). For an initial characterization of this conditional mouse model, germline excision of the LSL cassette was performed to induce expression of the transgene in all mouse tissues (HA-hPIT1tg/+). Recombination was confirmed using genomic DNA obtained from blood samples of these mice.

Intraperitoneal pyrophosphate treatment reduces renal calcifications in Npt2a null mice.

Mutations in the proximal tubular sodium-dependent phosphate co-transporters NPT2a and NPT2c have been reported in patients with renal stone disease and nephrocalcinosis, however the relative contribution of genotype, dietary calcium and phosphate, and modifiers of mineralization such as pyrophosphate (PPi) to the formation of renal mineral deposits is unclear. In the present study, we used Npt2a-/- mice to model the renal calcifications observed in these disorders. We observed elevated urinary excretion of PPi in Npt2a-/- mice when compared to WT mice.