No abstract

Background: Peritendinous injection of local anesthetics, alone or in combination with corticosteroids, is widely used in the treatment of tendinopathies. Toxicity of local anesthetics has been demonstrated in many cells, including myocytes, chondrocytes, and neurons. Bupivacaine and lidocaine are known to have time- and dose-dependent cytotoxicity in these cells. The effects of these agents on the tendon remain unknown. Purpose: To show histological and biomechanical effects after the injection of different local anesthetics and steroids, both single and combined, at different concentrations into the peritendinous sheath of rat Achilles tendon. Study Design: Controlled laboratory study. Methods: In the study, 100 rats were divided into 10 groups with equal body weights. Inflammation was induced in both Achilles tendons of each rat by means of the ball drop technique; 7 hours later, injections were made into the peritendinous sheaths of both Achilles tendons using lidocaine, bupivacaine, and dexamethasone as appropriate for the rat’s group. At the end of the first week, the right Achilles tendons of the rats were removed for histological study. Left Achilles tendons were evaluated in terms of biomechanics. Results: Histological findings demonstrated that the group with the most toxicity to the tendon was the group that received injection of dexamethasone alone. The groups with the least toxicity were those receiving dexamethasone combined with low- or high-dose bupivacaine. Biomechanical findings showed that the experimental groups had similar results to each other with the exception of the groups receiving 0.25% bupivacaine alone and dexamethasone alone, in which tendons revealed higher tensile strength. Conclusion: Local anesthetic and steroid applications have different histological and biomechanical effects on the tendon. Although the dexamethasone-injected group was the most affected in terms of histology, these changes could not be demonstrated biomechanically. Clinical Relevance: In future clinical studies, the effect of steroids on the tendon should be investigated more comprehensively. Whether biomechanical results overlap with histological results should be investigated further.

The increase in autoimmune diseases in recent years has drawn attention back to the thymus, with new approaches to improve and/or restore immune function being investigated. As the primary lymphoid organ responsible for functional T cell development, studies on the pre-/post-natal development of this organ and T lymphocytes in human and other species are of special interest. During our screening studies we observed structures that had not been described or mentioned previously, and named them "epitheliostromal sheaths". Associated with these unique structures were also small attached lobules (possibly reflecting the maturational stages of thymic lobules), which the authors consider as markers of histogenesis and the growth of the organ during early childhood; these findings are thus presented to researchers in this field. Approximately 1000 sections prepared from infantile thymic tissues of partial biopsy specimens were immunostained and examined. Specimens were taken from ten patients (with informed consent) in the age range of 4-9 years who underwent surgery due to congenital cardiovascular anomalies but were otherwise normal. Digital images of interest were captured to describe them in detail. Determining the immunophenotype of the compartments in these newly developing lobules assisted us greatly in defining compartments and their growth order. In summary, our findings suggest a niche-based thymus growth mechanism during childhood. We presented our findings, hoping to provide additional insight to researchers aiming to restore thymus function in adulthood and improve its immunological functions.

Trophoblasts perform different functions depending on their location. This study aimed to obtain structural clues about the functions of villous and extravillous trophoblasts by using light and electron microscopy. Term placenta samples were obtained from 10 healthy pregnant women following cesarean sections. Frozen sections were stained with hematoxylin-eosin, semithin sections were stained with toluidine blue and examined with a light microscope, while thin sections were contrasted using uranyl acetate-lead citrate and evaluated under an electron microscope. Fine structural features of villous trophoblasts overlapped some villous stromal cells. In addition to the usual appearance of mature capillaries in villous stroma, we demonstrated and reported maturational stages of angiogenetic sprouts in term placenta. Extravillous trophoblasts were classified according to their location: fibrinoid, chorion, trophoblastic, column, maternal vascular endothelium, or decidua. All of these trophoblasts shared some ultrastructural features but also were distinct from each other. In decidua, it was noted that the endothelial lining of some vessels was invaded by a few endovascular trophoblasts with irregular microvilli. These cells shared some ultrastructural properties with both villous trophoblasts and stromal cells. Examination showed that angiogenesis was still present in term placentas and that trophoblasts, endothelial and stromal cells have very similar properties ultrastructurally, suggesting they represent transformational forms.

BackgroundSugammadex is a modified gamma‐cyclodextrin that has been developed with the goal of reversing the steroidal neuromuscular blocking agents. The aim of the present study is to investigate the effects of different sugammadex doses on embryologic and neural tube development in an early‐stage chick embryo model.MethodsA total of 100 specific pathogen‐free, fertilized domestic chicken eggs were randomly divided into five groups (n = 20, each), and placed in an automatic cycle incubator. The eggs in the “control (C)” group were incubated without administration of any drug till the end of the experiment. Sub‐blastodermic administration of 0.9% NaCl as vehicle control (VC) and different doses of sugammadex solutions prepared with the latter [2 mg/mL (LD), 4 mg/mL (MD), 16 mg/mL (HD)] were performed at 30 hr of incubation. All embryos were removed from the eggs at 72 hr when they were expected to reach Hamburger‐Hamilton (HH) stages 19–20, then they were fixed, and evaluated histo‐morphologically.ResultsEmbryonic development was not observed in 11 eggs (1 in C, 1 in VC; 3 in LD, 3 in MD, and 3 in HD). All the developed embryos were compatible with the HH stages 19–20. A neural tube closure defect was detected in one embryo in the HD group. No statistically significant difference was found between the groups in terms of embryonic and neural tube developments.ConclusionsNo significant association was found between the drug and adverse outcomes; however, a trend with dosing was seen. Further studies are required before conclude on safety and extrapolate these results to human beings.