The aim of the current study was to investigate the simultaneous measurement of plasma p-aminohippuric acid (PAH) clearance as a potential marker to assess effective renal plasma flow (eRPF) and tubular secretion (TS), and the plasma clearance of iohexol (IOH) as a marker of the glomerular filtration rate in poultry species. The PAH was administered intravenously (IV) to broiler chickens, layers, turkeys, Muscovy ducks, and pigeons. Each animal received successively a single bolus dose of 10 mg PAH/kg bodyweight (BW) and 100 mg PAH/kg BW to assess the eRPF and TS, respectively. Simultaneously with both PAH administrations, a single IV bolus of 64.7 mg/kg BW of IOH was administered. A high linear correlation (R² = 0.79) between eRPF, based on the clearance of the low dose of PAH, and BW was observed for the poultry species. The correlation between TS, based on the clearance of the high dose of PAH, and BW was moderate (R² = 0.50). Finally, a moderate correlation (R² = 0.68) was demonstrated between GFR and eRPF and between GFR and TS (R² = 0.56). This presented pharmacokinetic approach of the simultaneous administration of IOH and PAH enabled a simultaneous evaluation of eRPF/TS and GFR, respectively, in different poultry species.

Aims: Approximately 10% to 20% of knee arthroplasty patients are not satisfied with the result, while a clear indication for revision surgery might not be present. Therapeutic options for these patients, who often lack adequate quadriceps strength, are limited. Therefore, the primary aim of this study was to evaluate the clinical effect of a novel rehabilitation protocol that combines low-load resistance training (LL-RT) with blood flow restriction (BFR).Methods: Between May 2022 and March 2024, we enrolled 45 dissatisfied knee arthroplasty patients who lacked any clear indication for revision to this prospective cohort study. All patients were at least six months post-surgery and had undergone conventional physiotherapy previously. The patients participated in a supervised LL-RT combined with BFR in 18 sessions. Primary assessments included the following patient-reported outcome measures (PROMs): Knee injury and Osteoarthritis Outcome Score (KOOS); Knee Society Score: satisfaction (KSSs); the EuroQol five-dimension five-level questionnaire (EQ-5D-5L); and the pain catastrophizing scale (PCS). Functionality was assessed using the six-minute walk Test (6MWT) and the 30-second chair stand test (30CST). Follow-up timepoints were at baseline, six weeks, three months, and six months after the start.Results: Six weeks of BFR with LL-RT improved all the PROMs except the sports subscale of the KOOS compared to baseline. Highest improvements after six weeks were found for quality of life (QoL) (mean 28.2 (SD 17.2) vs 19 (SD 14.7); p = 0.002), activities of daily living (mean 54.7 (SD 18.7) vs 42.9 (SD 17.3); p < 0.001), and KSSs (mean 17.1 (SD 8.8) vs 12.8 (SD 6.7); p < 0.001). PROMs improvements continued to be present at three-month and six-month follow-up compared to baseline. However, no significant differences were observed in the paired comparisons of the six-week, three-month, and six-month follow-up. The same trends are observed for the 6MWT and 30CST.Conclusion: The reported regime demonstrates improved QoL and function of dissatisfied knee arthroplasty patients. In light of this, the pathway described may provide a valuable and safe treatment option for dissatisfied knee arthroplasty patients for whom therapeutic options are limited.Cite this article: Bone Joint J 2024;106-B(12):1416–1425.