[Proximal tibial aspect ratio and matching of tibial component in total knee arthroplasty: a narrative review].

Proximal tibial aspect ratio (PTAR) is closely related to age, disease status and cutting parameters with considerable inter-individual variation independent of gender and race, nevertheless the aspect ratio of tibial components from different manufacturers remains relatively constant from smallest to largest size. As a result, component mismatching is an unavoidable dilemma during tibia preparation in total knee arthroplasty (TKA). Various prosthesis systems all can achieve more than 80% coverage on proximal tibia, whereas their optimal fit rates are generally not more than 50%. It is difficult for symmetrical components to avoid anteroposterior mismatch, internal malrotation tends to occur when maximum coverage is pursued on the resected surface with a medial dominant plateau or lower PTAR. Although it is easier to achieve a balance of rotation and coverage with anatomical components, significant anteromedial overhang tends to appear on the resected surface with a symmetrical or lateral dominant plateau. Further researches should focus on the law of inter-individual variability of proximal tibial morphology, the quantitative definition of "ideal matching" safety zone of key morphological parameters on different areas of proximal tibia and the methodology of realizing"ideal matching"in the majority patients with the least amount of component sizes. In addition, with the rapid development of additive manufacturing and digital orthopedic technology, individual customized implant is expected to become a breakthrough point in the field of TKA component fitting.

[Rotational alignment of the tibial component in total knee arthroplasty:a narrative review].

Component malrotation is one of the major causes of failure in total knee arthroplasty.Based on previous researches,Insall line has excessive external rotation tendency.Although Akagi line is the most recognized anatomical axis at present,it still has a certain tendency of internal rotation.The tibial posterior condylar axis is not suitable for symmetrical component and yet the Curve-on-Curve technique is not suitable for anatomic component.In addition,reference to any fixed anatomical markers cannot ensure the rotation consistency of tibiofemoral component in extension position.Although range of motion technique is beneficial to tibiofemoral rotation synchronization,its clinical effect seems to be unstable.Nevertheless,Patients can obtain good postoperative results with all major techniques.Before the recognized "gold standard" is defined,orthopedic surgeons can determine the rotation alignment of tibial component according to their most accustomed surgical method.With a deeper understanding of knee anatomy,biomechanics and kinematics,digital assistive technology may be expected to become a breakthrough in the tibial rotational alignment.

Dexmedetomidine regulate the malignancy of breast cancer cells by activating α2-adrenoceptor/ERK signaling pathway.

OBJECTIVE: Breast cancer is one of the most aggressive and pervasive cancers identified in females. Dexmedetomidine (Dex) is an efficient anesthetic used in surgery. Our study aimed to explore the role of Dex in the malignancy of breast cancer cells in vitro and in vivo. Further, we investigate the molecular mechanism involved in the function of Dex on breast cancer cells. MATERIALS AND METHODS: The methyl thiazolyl tetrazolium (MTT) assay was applied to detect cell proliferation. The migration and invasion capacity of MDA-MB-231 cells was tested by wound healing assay and transwell assay. Western blot analysis was performed to quantify the protein expression levels of α2-adrenoceptor and ERK. RESULTS: The proliferation, migration and invasion ability of MDA-MB-231 cells was gradually increased after treatment of Dex in a dose-dependent manner in vitro. In addition, Dex could significantly elevate the volume and weight of xenotransplant tumor in vivo. Furthermore, Dex up-regulated the protein level of a2-adrenoceptor and consistently enhanced the phosphorylation of ERK without changing the total level of it. Similarity, over-expression of a2-adrenoceptor via its agonist Clonidine could mimic the function of Dex on breast cancer. CONCLUSIONS: These data suggest that Dex could promote the proliferation, migration and invasion of breast cancer cells through the activation of α2B-adrenoceptor /ERK signaling.

Tramadol regulates proliferation, migration and invasion via PTEN/PI3K/AKT signaling in lung adenocarcinoma cells.

OBJECTIVE: Tramadol is used mainly for the treatment of moderate to severe chronic cancer pain. However, the effect of tramadol on lung cancer remains unclear. Therefore, it is important to explore the mechanism accounting for the function of tramadol on lung cancer. MATERIALS AND METHODS: We investigated the effects of tramadol on the proliferation, migration and invasion in human lung adenocarcinoma cells in vitro by CCK-8 assay, wound healing assay and Transwell assay, respectively. We also explored the potential mechanism of tramadol on lung cancer cells by Western blotting. RESULTS: A549 and PC-9 cells were incubated with 2 µM tramadol for different time (0, 7, 14 and 28 d). The in vitro experiments showed that tramadol treatment significantly inhibited cell proliferation, migration and invasion in a time-dependent manner. Moreover, administration of tramadol suppressed tumor growth in vivo. The data also revealed that tramadol could up-regulate the protein expression level of PTEN and consistently inhibit the phosphorylation level of PI3K and Akt, whereas the total level of PI3K and Akt remain unchanged. CONCLUSIONS: These findings indicated that tramadol inhibited proliferation, migration and invasion of human lung adenocarcinoma cells through elevation of PTEN and inactivation of PI3K/Akt signaling.

Triterpenoids from Pulsatilla chinensis.

A new lupane type triterpenic acid, pulsatillic acid, and two new lupane type triterpenoid glycosides, pulsatilloside A and B, along with the known 23-hydroxybetulinic acid were isolated from the roots of Pulsatilla chinensis. Their structures were characterized as 3-oxo-23-hydroxy-lup-20(29)-en-28-oic acid, 3 beta, 23-dihydroxy-lup-20(29)-en-28-oic acid 3-O-alpha-L-arabinopyranoside and 3 beta, 23-dihydroxy-lup-20(29)-en-28-oic acid 28-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranoside on the basis of hydrolysis and spectral evidence including two-dimensional relay HOHAHA, one-dimensional multiple relay COSY and ROESY NMR techniques. Pulsatillic acid exhibited cytotoxic activities against P-388, Lewis lung carcinoma and human large-cell lung carcinoma.