Adenine, guanine and pyridine nucleotides in blood during physical exercise and restitution in healthy subjects

Maximal physical exertion is accompanied by increased degradation of purine nucleotides in muscles with the products of purine catabolism accumulating in the plasma. Thanks to membrane transporters, these products remain in an equilibrium between the plasma and red blood cells where they may serve as substrates in salvage reactions, contributing to an increase in the concentrations of purine nucleotides. In this study, we measured the concentrations of adenine nucleotides (ATP, ADP, AMP), inosine nucleotides (IMP), guanine nucleotides (GTP, GDP, GMP), and also pyridine nucleotides (NAD, NADP) in red blood cells immediately after standardized physical effort with increasing intensity, and at the 30th min of rest. We also examined the effect of muscular exercise on adenylate (guanylate) energy charge—AEC (GEC), and on the concentration of nucleosides (guanosine, inosine, adenosine) and hypoxanthine. We have shown in this study that a standardized physical exercise with increasing intensity leads to an increase in IMP concentration in red blood cells immediately after the exercise, which with a significant increase in Hyp concentration in the blood suggests that Hyp was included in the IMP pool. Restitution is accompanied by an increase in the ATP/ADP and ADP/AMP ratios, which indicates an increase in the phosphorylation of AMP and ADP to ATP. Physical effort applied in this study did not lead to changes in the concentrations of guanine and pyridine nucleotides in red blood cells

Use of Antibiotic-impregnated Polymethylmethacrylate (PMMA) Plates for Prevention of Periprosthetic Infection in Breast Reconstruction

Background:. Periprosthetic infections remain a major challenge for breast reconstruction. Local antibiotic delivery systems, such as antibiotic beads and spacers, have been widely used within other surgical fields, but their use within plastic surgery remains scarce. In this study, we demonstrate the use of antibiotic-impregnated polymethylmethacrylate (PMMA) plates for infection prophylaxis in tissue expander (TE)-based breast reconstruction. Methods:. A retrospective review of patients who underwent immediate breast reconstruction with prepectoral TEs over the span of 5 years performed by two surgeons was completed, revealing a total of 447 patients. Data pertaining to patient demographics, operative details, and postoperative outcomes were recorded. Fifty patients underwent TE reconstruction with the addition of a PMMA plate (Stryker, Kalamazoo, Michigan) impregnated with tobramycin and vancomycin. Antibiotic plates were removed at the time of TE-to-implant exchange. Patient-matching analysis was performed using the 397 patients without PMMA plates to generate a 50-patient nonintervention cohort for statistical analysis. Results:. The intervention cohort (n = 50) and 1:1 patient-matched nonintervention cohort (n = 50) demonstrated no statistically significant differences in patient demographics or operative characteristics other than PMMA plate placement. The rate of operative periprosthetic infection was 4% in the intervention group and 14% in the nonintervention group (P = 0.047). The rate of TE explantation was also reduced in the intervention group (6% versus 18%; P = 0.036). Follow-up averaged 9.1 and 8.9 months for the intervention and nonintervention groups, respectively (P = 0.255). Conclusion:. Local antibiotic delivery using antibiotic-impregnated PMMA plates can be safely and effectively used for infection prevention with TE-based breast reconstruction