Immediate and short-term effects of gait retraining on the knee joint moments and symptoms in patients with early tibiofemoral joint osteoarthritis: a randomized controlled trial

OBJECTIVE

To evaluate the effectiveness of a knee adduction moment (KAM) gait retraining in patients with early knee osteoarthritis up to 6 months post-training.

METHOD

We conducted a single blinded randomized controlled trial on a total of 23 patients with early knee osteoarthritis who were randomly allocated to the gait retraining group and walking exercise group. Twenty of them completed the corresponding training and the 6-month evaluation. We measured KAM, knee flexion moment (KFM) and western ontario and McMaster universities osteoarthritis index (WOMAC) osteoarthritis index before, immediate after, and 6 months after training. A repeated measures analysis of covariance (ANCOVA) was used to compare KAM, KFM and WOMAC osteoarthritis index scores across the three time points i.e., pre-training, post-training, and 6-month follow-up with gender, knee osteoarthritis severity, and pre-training KAM, KFM and WOMAC scores set as covariates. Post-hoc analyses were conducted when indicated.

RESULTS

Significant time × group interactions were found for both KAM and WOMAC osteoarthritis index scores (P < 0.002). No interaction was found for KFM (P = 0.123). KAM after gait retraining was significantly lower than the pre-training value (P < 0.001) and such effect was maintained at 6-month follow-up (P = 0.01). There was no significant difference in the KAM across time in the walking exercise group (P > 0.208). WOMAC osteoarthritis index score after training and score at the 6-month follow-up were significantly improved in the gait retraining group (P = 0.001), while the WOMAC osteoarthritis index score remained similar.

CONCLUSIONS

Gait retraining is an effective intervention to reduce KAM during walking and to improve the symptoms of patients with early knee osteoarthritis in short term.

Immediate effects of modified landing pattern on a probabilistic tibial stress fracture model in runners

BACKGROUND

Tibial stress fracture is a common injury in runners. This condition has been associated with increased impact loading. Since vertical loading rates are related to the landing pattern, many heelstrike runners attempt to modify their footfalls for a lower risk of tibial stress fracture. Such effect of modified landing pattern remains unknown. This study examined the immediate effects of landing pattern modification on the probability of tibial stress fracture.

METHODS

Fourteen experienced heelstrike runners ran on an instrumented treadmill and they were given augmented feedback for landing pattern switch. We measured their running kinematics and kinetics during different landing patterns. Ankle joint contact force and peak tibial strains were estimated using computational models. We used an established mathematical model to determine the effect of landing pattern on stress fracture probability.

FINDINGS

Heelstrike runners experienced greater impact loading immediately after landing pattern switch (P<0.004). There was an increase in the longitudinal ankle joint contact force when they landed with forefoot (P=0.003). However, there was no significant difference in both peak tibial strains and the risk of tibial stress fracture in runners with different landing patterns (P>0.986).

INTERPRETATION

Immediate transitioning of the landing pattern in heelstrike runners may not offer timely protection against tibial stress fracture, despite a reduction of impact loading. Long-term effects of landing pattern switch remains unknown.

Barley low molecular weight β-glucan potently induces maturation of mouse dendritic cells

BACKGROUND

Accumulating evidence indicates that non-toxic immunostimulants with strong differentiation/maturation-inducing activity for dendritic cells (DCs) might be useful for preventing or even curing cancer.

MATERIALS AND METHODS

Mouse bone marrow (BM) cells were cultured in the presence of various glucans and their differentiation/maturation-inducing activities were compared by measuring cytokines secreted in the culture medium.

RESULTS

Barley-derived β-glucan with an average molecular weight of 2 kDa (BBG-Low) remarkably stimulated the formation of mature DCs from immature mouse DCs. The amount of interleukin-6 produced by sequential treatment of BM cells with granulocyte-macrophage colony-stimulating factor and 10 μg/mL of BBG-Low was approximately 30 times higher than that obtained by a similar sequential treatment using barley β-glucan of 40-70 kDa instead of BBG-Low.

CONCLUSION

BBG-Low induces the formation of mature DCs from immature DCs and suggests that BBG-Low will be useful as a potent nontoxic immunostimulator.

[A preliminary study on the occlusal contact changes during retention in adolescent patients]

OBJECTIVE

To evaluate the changes of the occlusal contact characteristics in adolescent patients during 12 months after active orthodontic treatment.

METHODS

Twenty adolescent patients with Hawley retainers after active orthodontic treatment were divided into none occlusal interference group and occlusal interference group. The occlusion of the patients was examined with T-Scan II system directly after the appliance removal (T1) and after an average retention period of 12 months (T2). The changes of occlusal contact characteristics were observed.

RESULTS

The disclusion time during protrusion, left and right lateral movements reduced significantly. The average disclusion time decreased [from (1.07 ± 0.87), (0.91 ± 0.47), (0.76 ± 0.43) s to (0.43 ± 0.25), (0.67 ± 0.41), (0.50 ± 0.27) s] significantly (P < 0.05). The occlusal interference disappeared in 4 patients and 1 patient with occlusal interference showed masticatory muscle symptom. The dynamic occlusion [from (1.25 ± 1.11), (0.84 ± 0.15), (0.52 ± 0.49) s to (0.35 ± 0.15), (0.36 ± 0.15), (0.33 ± 0.11) s] improved significantly (P < 0.05) in none occlusal interference group after retention and no statistical differences were found in the occlusal interference group (P > 0.05).

CONCLUSIONS

The overall dynamic occlusion improved after retention in patients with retainers. The presence of occlusal interference affected the self-improvement process and increased the chance of the disorders of stomatognathic system, such as mandibular abnormal movements. Therefore, functional occlusion evaluation and final detailing were needed before appliance removal.

[Genetic diversity of different geographical populations of Oxya chinensis based on AFLP analysis]

In order to study the genetic diversity and genetic structure of populations, 7 populations of Oxya chinensis from 7 provinces (or cities) of China were analyzed using AFLP technique. A total of 336 reproducible bands were amplified with 7 primer combinations from 128 individuals. Two hundred and ninety-two bands (86.90%) were polymorphic. High genetic diversity was found among O. chinensis populations and Wanning population had higher genetic diversity than other populations. Mantel test (r=0.27, P=0.89) suggested that there was no significant association between genetic distance and geographic distance. Remarkable genetic differentiation was found among populations. Unweighted pair group method average (UPGMA) tree showed that the 7 O. chinensis populations were divided into 3 groups: Changping of Beijing, Tai-yuan of Shanxi and Jining of Shandong populations in the north; Hanzhong of Shaanxi, Changsha of Hunan and Laibin of Guangxi populations in the south; and Wanning of Hainan population. Principal component analysis indicated significant genetic differentiation of the north and the south populations and island and continent populations existed in the 7 O. chinensis populations because of geographic isolation.

Dendritic cell differentiation and tumor cell apoptosis induced by components of a poly-phenylpropanoid polysaccharide complex

BACKGROUND

As part of the indigenous folk medicine in Japan, aqueous extracts of pine cones have been used for over a century to treat cancer and other illnesses and references to their use can be found in ancient Greek literature. However, the mechanisms by which such extracts work are largely unknown.

MATERIALS AND METHODS

Murine bone marrow (BM)-derived dendritic cells (DCs) and human monocyte U937 cells were treated in vitro with an extract prepared from pine cones (termed poly-phenylpropanoid polysaccharide complex, PPC).

RESULTS

The components of the PPC were separated into different molecular weight fractions with distinct biological activities. One fraction, consisting of relatively high molecular weight material, was found to induce the differentiation of murine BM cells into immature DC, as well as the maturation of immature DCs into mature DCs. A second fraction, consisting of low molecular weight material, was found to inhibit the in vitro growth of the U937 cells and two other human cancer cell lines. The inhibition of tumor cell growth was found to be associated with the generation of reactive oxygen species (ROS) and the induction of a mitochondria-dependent apoptotic pathway.

CONCLUSION

The effects on dendritic cells and the inhibition of tumor growth, if they occur to a significant level in vivo, could help explain the apparent usefulness of PPC in the treatment of cancer.

Mitogen-activated protein kinase-dependent apoptosis in norcan-tharidin-treated A375-S2 cells is proceeded by the activation of protein kinase C

BACKGROUND

We have reported that norcantharidin (NCTD) induces human melanoma A375-S2 cell apoptosis and that the activation of caspase and the mitochondrial pathway are involved in the apoptotic process. This study aimed at investigating the roles of mitogen-activated protein kinase (MAPK) and protein kinase C (PKC) in A375-S2 cell apoptosis induced by NCTD.

METHODS

We assessed the effects of NCTD on cell growth inhibition using the 3-(4,5-dimethylthiazol-2-yl)-2,5-dipheyltetrazolium bromide (MTT) assay, DNA fragmentation (DNA agarose gel electrophoresis), and MAPK protein levels (Western blot analysis) in A375-S2 cells. Photomicroscopic data were also collected.

RESULTS

The NCTD inhibitory effect on A375-S2 cells was partially reversed by MAPK and PKC inhibitors. The expression of phosphorylated JNK and p38 also increased after the treatment with NCTD, and inhibitors of c-Jun NH2-terminal kinase (JNK) and p38 (SP600125 and SB203580, respectively) had significant inhibitory effects on the upregulation of phosphorylated JNK and p38 expression. Simultaneously, the PKC inhibitor staurosporine blocked the upregulation of phosphorylated JNK and phosphorylated p38, but had little effect on extracellular signal-regulated kinase (ERK) expression.

CONCLUSION

These results suggest that the activation of JNK and p38 MAPK promotes the process of NCTD-induced A375-S2 cell apoptosis and that PKC plays an important regulation role in the activation of MAPKs.

Norcantharidin induces human melanoma A375-S2 cell apoptosis through mitochondrial and caspase pathways

Norcantharidin (NCTD) is the demethylated form of cantharidin, which is the active substance of mylabris. To examine the pathway of NCTD-induced A375-S2 cell death, 3-(4, 5-dimethylthiazol-2-yl)-2, 5-dipheyltetrazolium bromide (MTT) assay, photomicroscopical observation, DNA agarose gel electrophoresis, caspase activity assay and Western blot analysis were carried out. A375-S2 cells treated with NCTD exhibited several typical characteristics of apoptosis. The inhibitory effect of NCTD on human melanoma, A375-S2 cells, was partially reversed by the inhibitors of pan-caspase, caspase-3 and caspase-9. The activities of caspase-3 and -9 were significantly increased after treatment with NCTD at different time. The expression of inhibitor of caspase-activated DNase was decreased in a time-dependent manner, simultaneously, the ratio of Bcl-2/Bax or Bcl-xL/Bax was decreased and the expression ratio of proteins could be reversed by caspase-3 inhibitor. The expression of cytochrome c in cytosol was increased after NCTD treatment and caspase- 3 inhibitor had no significant effect on the up-regulation of cytochrom c. These results suggest that NCTD induced A375-S2 cell apoptosis and the activation of caspase and mitochondrial pathway were involved in the process of NCTD-induced A375-S2 cell apoptosis.