Uremic Toxins and Ciprofloxacin Affect Human Tenocytes In Vitro

Unveiling the association between fluoroquinolones and aortic diseases using real-world database analysis and pharmacological experiments

Fluoroquinolones, which are widely used antibiotics, have been linked to aortic disease, which prompted an FDA warning in 2018. Recent reports have challenged the perception that fluoroquinolones pose a significant risk for vascular diseases. This study aimed to investigate whether fluoroquinolones increase the risk of aortic diseases by focusing on the onset of aortic dissection. Levofloxacin (LVFX), a fluoroquinolone, was studied in vitro using cultured vascular cells and in vivo using a mouse model prone to aortic dissection. Risk of adverse drug events was analyzed using VigiBase, a global safety database, and a retrospective cohort analysis was conducted using the JMDC Claims database. LVFX resulted in endothelial cell injury and increased matrix metalloproteinases in vitro. However, in vivo studies showed no significant effect on elastin degradation or aortic dissection incidence. The effect of LVFX on endothelial injury was altered during the onset of dissection, exacerbating injury before onset but inhibiting it afterward. Safety database analysis showed no significant risk signals for aortic dissection associated with fluoroquinolones, which was supported by findings in the receipt database. Inconsistencies were observed in the in vitro and in vivo actions of fluoroquinolones and differences in their effects on aortic dissection and aneurysms. Despite cytotoxicity, the risk of aortic dissection was not significantly increased in clinical scenarios. Based on our findings, concerns regarding aortic diseases do not justify discontinuation of fluoroquinolone use. Further studies are needed to elucidate the conflicting actions of fluoroquinolones, taking into account background pathophysiology such as infection and inflammation.

Patellar tendon biomechanical and morphologic properties and their relationship to serum clinical variables in persons with prediabetes and type 2 diabetes

Tendon biomechanical properties and fibril organization are altered in patients with diabetes compared to healthy individuals, yet few biomarkers have been associated with in vivo tendon properties. We investigated the relationships between in vivo imaging-based tendon properties, serum variables, and patient characteristics across healthy controls (n = 14, age: 45 ± 5 years, body mass index [BMI]: 24 ± 1, hemoglobin A1c [HbA1c]: 5.3 ± 0.1%), prediabetes (n = 14, age: 54 ± 5 years, BMI: 29 ± 2; HbA1c: 5.7 ± 0.1), and type 2 diabetes (n = 13, age: 55 ± 3 years, BMI: 33 ± 2, HbA1c: 6.7 ± 0.3). We used ultrasound speckle-tracking and measurements from magnetic resonance imaging (MRI) to estimate the patellar tendon in vivo tangent modulus. Analysis of plasma c-peptide, interleukin-1β (IL-1β), IL-6, IL-8, tumor necrosis factor-α (TNF-α), adiponectin, leptin, insulin-like growth factor 1 (IGF-1), and C-reactive protein (CRP) was completed. We built regression models incorporating statistically significant covariates and indicators for the clinically defined groups. We found that tendon cross-sectional area normalized to body weight (BWN CSA) and modulus were lower in patients with type 2 diabetes than in healthy controls (p < 0.05). Our regression analysis revealed that a model that included BMI, leptin, high-density lipoprotein (HDL), low-density lipoprotein (LDL), age, and group explained ~70% of the variability in BWN CSA (R2 = 0.70, p < 0.001). For modulus, including the main effects LDL, groups, HbA1c, age, BMI, cholesterol, IGF-1, c-peptide, leptin, and IL-6, accounted for ~54% of the variability in modulus (R2 = 0.54, p < 0.05). While BWN CSA and modulus were lower in those with diabetes, group was a poor predicter of tendon properties when considering the selected covariates. These data highlight the multifactorial nature of tendon changes with diabetes and suggest that blood variables could be reliable predictors of tendon properties.

Bilateral rupture of the quadricipital tendon in patients with chronic kidney disease: The peculiarities of management (case report)

INTRODUCTION

Bilateral forms of quadricipital tendon rupture are rare. They are usually associated with predisposing factors, such as secondary hyperparathyroidism due to chronic renal failure, which need to be treated to avoid recurrence.

PRESENTATION OF CASE

A 38-year-old man with a medical history of chronic kidney failure was presented to the hospital for bilateral quadricipital tendon ruptures after a low-energy trauma. Ruptures were in the midportion of the tendon on the right side and in the level of patellar insertion on the left side. We performed a surgical reparation. One year after surgery, he consulted for a recurrence of the left quadricipital tendon rupture after an impeded extension movement. Biology showed secondary hyperparathyroidism due to chronic renal failure. Surgical reparation and reconstruction by a graft tendon were performed. As for his secondary hyperparathyroidism, he got a sub-parathyroidectomy after medical treatment failure. Recovery was remarkably uneventful.

DISCUSSION

Despite the early diagnosis and treatment of a bilateral quadricipital tendons rupture, our patient had an iterative rupture. His secondary hyperparathyroidism due to chronic renal failure may weaken the tendon system through physiological and histological modifications, as it is reported in the literature. As a result, treating a bilateral rupture as a banal post-traumatic lesion without management of the predisposing factors may lead to recurrences.

CONCLUSION

A non or low-traumatic tendon rupture in a patient with a history of chronic renal failure needs to identify secondary hyperparathyroidism, which must be treated to avoid recurrences.

Decellularization of Dense Regular Connective Tissue-Cellular and Molecular Modification with Applications in Regenerative Medicine

Healing of dense regular connective tissue, due to a high fiber-to-cell ratio and low metabolic activity and regeneration potential, frequently requires surgical implantation or reconstruction with high risk of reinjury. An alternative to synthetic implants is using bioscaffolds obtained through decellularization, a process where the aim is to extract cells from the tissue while preserving the tissue-specific native molecular structure of the ECM. Proteins, lipids, nucleic acids and other various extracellular molecules are largely involved in differentiation, proliferation, vascularization and collagen fibers deposit, making them the crucial processes in tissue regeneration. Because of the multiple possible forms of cell extraction, there is no standardized protocol in dense regular connective tissue (DRCT). Many modifications of the structure, shape and composition of the bioscaffold have also been described to improve the therapeutic result following the implantation of decellularized connective tissue. The available data provide a valuable source of crucial information. However, the wide spectrum of decellularization makes it important to understand the key aspects of bioscaffolds relative to their potential use in tissue regeneration.

Editorial for Special Issue: Achilles Curse and Remedy: Tendon Diseases from Pathophysiology to Novel Therapeutic Approaches

In Greek mythology, Achilles, the Greek hero, is almost invulnerable-except for his Achilles heel, whose injury resulted in his death[...].