Mitochondrial dysfunction is increasingly recognized as a key factor in Alzheimer’s disease (AD) pathogenesis, but the precise relationship between mitochondrial dynamics and proteinopathies in AD remains unclear. This study investigates the role of mitochondrial dynamics and function in the hippocampal tissue and peripheral blood mononuclear cells (PBMCs) of 5xFAD transgenic mice, as a model of AD. The levels of mitochondrial fusion proteins OPA1 and MFN2 and fission proteins DRP1 and phospho-DRP1 (S616) at 3, 6, and 9 months of age were assessed. Western blot analysis revealed significantly lower levels of OPA1 and MFN2 in the hippocampus of 6- and 9-month-old transgenic (TG) 5xFAD mice compared to controls (CTR), while DRP1 and pDRP1 levels were increased in 9-month-old TG mice. Additionally, MFN2 were decreased in the PBMCs of 9-month-old TG mice, indicating systemic mitochondrial alterations. Ultrastructural analysis of hippocampal tissues showed substantial alterations in mitochondrial morphology, including abnormalities in size and shape, a preponderance of teardrop-shaped mitochondria, and alterations in the somatic mitochondria-ER complex. Notably, mitochondria-associated ER contact sites were more distant in TG mice, suggesting functional impairments. Flow cytometric measurements demonstrated decreased mitochondrial membrane potential and mass, along with increased superoxide production, in the PBMCs of TG mice, particularly at 9 months, highlighting compromised mitochondrial function. Levels of key mitochondrial proteins including VDAC, TOM2O, and mitophagy-related protein PINK1 levels altered in both central and peripheral tissue of TG mice. These findings suggest that mitochondrial dysfunction and altered dynamics are early events in AD development in 5xFAD mice, manifesting in both central and peripheral tissues, and support the notion that mitochondrial abnormalities are an integral component of AD pathology. These insights might lead to the development of targeted therapies that modulate mitochondrial dynamics and function to mitigate AD progression.
Vascular structures are in greater danger during lumbar surgery. The purpose of this study is to describe the morphology of the inferior vena cava (IVC) related to the lumbar vertebra and aortic bifurcation (AB) and assessing the role of demographic values in these relations to decrease the risk of complications in the surgical interventions. The study was performed on Multidetector Computed Tomography (MDCT) images of 100 male and 100 female cases with an age range from 50 to 84 years. The morphometric values of the IVC obtained from the coronal, sagittal and the axial reformatted images were measured and compared with the demographic values. The distance from the IVC to the 1 st lumbar vertebra (L1) and 2 nd lumbar vertebra (L2) were measured as (26.5 mm and 18.1 mm) in males and (21.1 mm and 14.2 mm) in females with a high level of significance between genders; the distance from the IVC to the iliocaval confluence (IC), 3 rd lumbar vertebra (L3) and 4 rd lumbar vertebra (L4) were measured as (6.5 mm, 10.5 mm and 6.9 mm) in males and (4.9 mm, 9.1 mm and 5.5 mm) in females with significance between genders. The level of the IC was detected 46 % of males, 39 % of females at the level of lower third of L4. The vertical distance between the IC and the AB was measured and negative correlation between genders based on age was detected. Demographic values are important to consider the relationship of the IVC, the lumbar vertebra and the AB. The IVC was located further from the lumbar vertebra in males compared to females. Age increase played role in the approaching of the AB and the IC to each other in both gender and the IC to the promontory level in males.
10 July 2020 in Journal of Orthopaedic Surgery and Research
BackgroundEFECE systems are newly defined internal fixation systems, which are suitable for patella fracture fixation. The aim of this study was to compare the fixation strength of EFECE Systems with tension band wiring for transverse patellar fracture simulation on fresh frozen cadaver models.MethodsQuadriceps tendon-patella-patellar tendon (QT-P-PT) complex was prepared from human cadavers. After simulation of a transverse patella fracture, in group 1, 5 patella were fixed with a pair of 1.2mm EFECE wires and 4 EFECE devices. In group 2, 5 patella were fixed with a pair of 1.2mm Kirschner wires (K-wire) and a cerclage wire according to the tension band technique.Using a testing device with custom-made jaws, increasing distraction force was applied to these QT-P-PT complexes. Extension of these complexes with the distraction forces was observed. The maximum distraction force and the elongation during maximum force were evaluated.ResultsAfter 5 experiments with the EFECE systems, there was no EFECE wire breakage or EFECE wire-EFECE device catching failure. The median maximum force was 740N (720-810N). During maximum distraction force the median extension was 2.5mm (1.6-2.5mm). After 5 experiments with the tension band technique, there was no K-wire breakage. The median maximum force was 330N (240-510N). During this maximum distraction force the median extension was 3.4mm (2.2-3.8mm).ConclusionsBased on the biomechanical advantages, patella fracture treatment with EFECE systems may constitute a reasonable alternative in the treatment of patella fractures.
28 January 2021 in Journal of Comparative Neurology
Objective: The aim of this study was to provide anatomic considerations in the first metatarsophalangeal joint (FMPJ) innervation and to evaluate the feasibility of the denervation surgery in the treatment of hallux rigidus. Methods: In this cadaveric study, 14 fresh frozen cadaveric transtibial amputation specimens was used. For nerve dissection, dorsal and plantar longitudinal incision centered over the FMPJ were performed. Deep peroneal and dorsomedial cutaneous nerves were dissected in the dorsal aspect of the joint. Medial plantar nerve branches, medial and lateral hallucal nerves, were dissected in the plantar aspect of the joint. The presence, number, and location of articular branches to the FMPJ capsule were recorded. Dorsal and plantar incision length for proper dissection were also recorded. Results: Nerve dissection of the 14 specimens revealed the following number of articular branches from the relevant nerves: 14 from dorsomedial cutaneous nerves, 11 from deep peroneal nerves, 6 from medial hallucal nerve, and 5 from lateral hallucal nerve. Dorsal incision mean length was 60.53 (range, 42.48˗85.12) mm, and the plantar incision mean length was 88.08 (range, 77.32˗111.21) mm. Conclusion: Evidence from this study has shown that partial dorsal denervation of the FMPJ may be a technically feasible procedure along with the presence of superficially easily dissected nerves with relatively small incision. Level of Evidence: Level 5 Cite this article as: Çatal B, Keskinbora M, Keskinöz EN, et al. Is denervation surgery possible in the treatment of hallux rigidus? An anatomic study of cadaveric specimens. Acta Orthop Traumatol Turc 2021; 55(4): 327–331.