Deep Circumflex Iliac Artery-vascularized Iliac Bone Graft for Femoral Head Osteonecrosis: Computed Tomography Anatomical Study.

BACKGROUND: Deep circumflex iliac artery (DCIA)-vascularized iliac graft transposition is a method for treating femoral head osteonecrosis but with inconsistent efficacy. We aim to improve the method of this surgery by recommending the optimal location of the iliac pedicle to satisfy the vascular length for transposition and the blood supply of the vascularized iliac graft. METHODS: The DCIA and its surrounding tissues were assessed on computed tomography angiography images for 100 sides (left and right) of 50 patients. The length of the vascular pedicle required for transposition and the length of the pedicle at different iliac spine positions were compared. The diameter and cross-sectional area of the DCIA and the distance between the DCIA and iliac spine were measured at different points to assess blood supply. We also compared differences in sex and left-right position. RESULTS: The diameter and cross-sectional area of the DCIA gradually decreased after crossing the anterior superior iliac spine (ASIS), and it approached the iliac bone. However, when the DCIA was 4 cm behind the ASIS (54 sides, 54%), it coursed posteriorly and superiorly away from the iliac spine. The vascular length of the pedicle was insufficient to transpose the vascularized iliac graft to the desired position when it was within 1 cm of the ASIS. The vascular length requirement was satisfied, and the blood supply was sufficient when the pedicle was positioned at 2 or 3 cm. CONCLUSION: To obtain a satisfactory pedicle length and sufficient blood supply, the DCIA pedicle of the vascularized iliac graft should be placed 2 to 3 cm behind the ASIS. The dissection of DCIA has slight differences in sex and left-right position due to anatomical differences.

Effects of Cryopreservation and Replantation on Muscles: Application Scope of Limb Cryopreservation.

BACKGROUND: Wang successfully replanted the severed fingers of 2 patients after cryopreservation in 2002 and 2003, which has enabled us to share our own experience for the knowledge interests of our colleagues and to further develop this technology. METHODS: Fifteen healthy adult male Sprague-Dawley rats were selected and divided into 5 groups (group 1: normal control, group 2: cryopreservation with protectant, group 3: cryopreservation without protectant, group 4: 6-hour postoperative, and group 5: 72-hour postoperative). After harvesting the hind limbs, cryoprotectant was applied to 20 limbs, and the rest were cryopreserved without cryoprotectant for 15 days. After being thawed, the amputated limb was replanted in situ. Nerves, skins and gastrocnemius muscles were collected for hematoxylin and eosin staining, terminal deoxynucleotidyl transferase dUTP nick end labeling staining, and transmission electron microscopy observation. RESULTS: Muscle and skin tissues treated with cryoprotectant restored a better outline after being frozen than those not treated, whereas nerves were not significantly different between the 2 groups. After replantation, some of the myofibrils of the muscle were in disarray, but the sarcomere structure remained intact at approximately 6 hours postoperatively. At 72 hours, a transmission electron microscopy scan showed that the myofibrillar arrangement was disorderly, with segmental myofilament breakage, and the sarcomere structure was destroyed in some cases. In addition, the scan revealed increased apoptotic cells and collapse of basic structures in the skin and nerves. CONCLUSIONS: Relative to that of skin and neuronal tissue, the replantation of muscle tissues through the cryopreservation method is more difficult.

Anti-osteosarcoma property of decorin-modified titanium surface: A novel strategy to inhibit oncogenic potential of osteosarcoma cells.

Osteosarcoma is the most common bone sarcoma in adolescents. Decorin (DCN) has been proposed to be a new anti-osteosarcoma therapeutic strategy. Our previous study has loaded decorin on titanium (Ti) surface by polydopamine (DOPA) as an anchor to enhance osseointegration. In this study, we investigated the effect of decorin-coated Ti substrates (TI-DOPA-DCN) on the oncogenic potential of osteosarcoma cells SAOS-2. The substrates were placed in 24-well plates for cell culture. Cell viability was determined by Cell Counting Kit-8 (CCK8) assay. Apoptosis was evaluated by DAPI staining and Annexin V-FITC/PI double staining analysis. Cell cycle was analyzed by flow cytometry. Cell migration and invasion were evaluated by Transwell assay. For co-culture, the pre-osteogenic cells MEC3T3-E1 and osteosarcoma cells SAOS-2 were stained with cell membrane fluorescent dyes, and then mixed (1:1) for co-culture. The cells were observed under a fluorescence microscope at four time points of 24, 48, 72, and 96 h. The results showed that TI-DOPA-DCN substrate can selectively inhibit cell proliferation of osteosarcoma cells but not pre-osteoblasts. However, the cell cycle of SAOS-2 was not affected by TI-DOPA-DCN substrates. Both DAPI staining and Annexin V-FITC/PI double staining analysis revealed that TI-DOPA-DCN substrates induced apoptosis of osteosarcoma cells. Transwell assay showed that TI-DOPA-DCN substrates inhibited invasion and migration of osteosarcoma cells. Moreover, TI-DOPA-DCN substrates inhibited the growth of osteosarcoma cells but promoted that of pre-osteoblasts in the coculture system. Taken together, these findings suggested that decorin coating on Ti surface simultaneously inhibited the oncogenic potential of osteosarcoma cells but enhanced cell growth of pre-osteoblasts, which could be applied to surface modification of Ti orthopedic implant.

A symptomatic cyamella in the popliteus tendon causing snapping knee: a case report and literature review.

BACKGROUND: Cyamella,the sesamoid bones of the popliteus muscle, are rare in humans. Snapping knee is an uncommon problem which can be difficult to diagnose. CASE PRESENTATION: In this case, we report a 24-year-old male with snapping knee caused by symptomatic cyamella in the popliteus tendon. A large cyamella was identified upon surgery and was removed. Postoperatively, the patient had immediate relief of preoperative symptoms, and there were no signs of recurrence after 1 years of follow-up. CONCLUSIONS: Although not previously suggested, symptomatic cyamella in the popliteus tendon should be considered as part of the differential diagnosis of the snapping knee.

Extra-articular tenosynovial chondromatosis of the left ring finger in a 23-year-old man: A case report and literature review.

Tenosynovial chondromatosis is an extra-articular version of articular synovial chondromatosis and a relatively rare condition that can affect the tendon sheath, bursa, or joint synovial tissue. Tenosynovial chondromatosis is rarely reported in the literature and is often misdiagnosed. In the present study, a case of extra-articular tenosynovial chondromatosis of the left ring finger in a 23-year-old man is reported. Three different-sized nodules were identified upon surgery and all were removed via synovectomy. The patient was symptom free 6 months postoperatively, and there were no signs of recurrence after 1.5 years of follow-up. The literature describing tenosynovial chondromatosis in the fingers is also reviewed.

Chaperonin containing T-complex polypeptide subunit eta is a potential marker of joint contracture: an experimental study in the rat.

Joint contracture is a fibroproliferative disorder that restricts joint mobility, resulting in tissue degeneration and deformity. However, the etiology of joint contracture is still unknown. Chaperonin containing T-complex polypeptide subunit eta (CCT-eta) is reported to increase in fibrotic diseases. The purpose of this study was to investigate whether CCT-eta is implicated in joint contracture and to determine the role of CCT-eta in the progression of joint contracture by analyzing a rat model. We immobilized the left knee joint of rat by internal fixation for 8 weeks. The non-immobilized right leg served as a control. The range of motion (ROM) of the knee was investigated. Fibroblasts were obtained from the posterior joint capsule of the joints. The outcome was followed by quantitative real-time polymerase chain reaction (qRT-PCR), Western blot, fibroblast migration assay, and collagen assay. The effect of CCT-eta on the functions of fibroblasts was observed by utilizing a short inhibitory RNA (siRNA) targeting CCT-eta. The ROM of the immobilized joints was significantly limited compared to the contralateral joints (p < 0.05). Fibroblasts derived from the contractive joints showed higher mRNA and protein expressions of CCT-eta in parallel with alpha-smooth muscle actin (α-SMA) compared to the cells from the contralateral knees (p < 0.05). siRNA-mediated downregulation of CCT-eta inhibited the expressions of both CCT-eta and α-SMA. Moreover, the reduction of CCT-eta also significantly decreased fibroblast functions such as cell mobility and collagen synthesis (all p < 0.05). Our findings indicate that CCT-eta appears to be a potential marker of joint contracture disease.

The cyanate and 2-phosphaethynolate anion congeners ECO- (E = N, P, As, Sb, Bi): prelude to experimental characterization.

Pioneering synthetic research by the groups of Grutzmacher and Goicoechea have made possible the preparation of 2-phosphaethynolates (PCO(-)). The obvious question arises: can progress be made toward AsCO(-), SbCO(-), and BiCO(-)? Here the properties of all five anion congeners ECO(-) (E = N, P, As, Sb, Bi) were systematically investigated using ab initio coupled-cluster methods with correlation-consistent basis sets cc-pVXZ (X = D, T, Q). These anions exhibit linear structures with significant natural bond orbital negative charge on both the E and O atoms. These species should react with electrophiles via attack at either center. On going from nitrogen to bismuth, with the atomic radius increasing, the bond between E and C becomes weaker, while the C-O bond tends to be slightly stronger. By the time one gets to BiCO(-), the C-O bond distance is 1.181 Å, indicating a very strong double bond. Relative to the PCO(-) anion, which is reactive toward several unsaturated compounds, the As/Sb/BiCO(-) anions may undergo cycloaddition more readily with unsaturated substrates. The dissociation energy of the E-C bond, except for that of NCO(-), is predicted to be much less than that of the C-O bond. These dissociation energies are 76 kcal/mol (P(-)-CO), 58 kcal/mol (As(-)-CO), 37 kcal/mol (Sb(-)-CO), and 28 kcal/mol (Bi(-)-CO). Even the BiCO(-) anion should be achievable in the laboratory. The vibrational frequencies for these anions are predicted, and our results should assist in the experimental characterization and exploration of the heavier congeners ECO(-).

Mechanism for the autophosphorylation of CheA histidine kinase: QM/MM calculations.

The CheA histidine kinase, a model of TCS (the two-component system), mediates the signal transduction pathway of bacterial chemotaxis via autophosphorylation. Since the TCSs are rarely found in mammalians, they have become attractive targets for the development of new antibiotics. To characterize the autophosphoryl-transfer mechanism of CheA histidine kinase, molecular dynamics simulations combined with quantum mechanics/molecular mechanics calculations were employed on the constructed 3D model of P1-P4-ATP complex. A two-step reaction mechanism was proposed and confirmed by our computations: the autophosphoryl-transfer reaction takes place followed by a rapid and reversible conformational change from ground state to prechemistry state. In addition, a two-dimensional potential energy surface was calculated for autophosphorylation, and the transition state displays an associative character. Moreover, we found Lys48 serves as the catalytic acid to stabilize transition state through a water-mediated proton-transfer pathway, and Glu67 acts as not only a hydrogen bond acceptor but also a structure anchor to modulate the imidazole ring of His45 in the active site. Our findings clearly provide a detailed autophosphoryl-transfer mechanism of CheA histidine kinase and thus are important for discovering new antibiotics.