Bone Tunnel Diameter Measured with CT after Anterior Cruciate Ligament Reconstruction Using Double-Bundle Auto-Hamstring Tendons: Clinical Implications

ObjectiveTo evaluate the correlation between bone tunnel diameter after anterior cruciate ligament (ACL) reconstruction measured by computed tomography (CT) using multiplanar reconstruction (MPR) and stability or clinical scores.ResultsThe tibial bone tunnels for the anteromedial bundles were significantly widened at T2 compared with T1 (observer 1, 0.578 mm to 0.698 mm, p value of < 0.001; observer 2, 0.581 mm to 0.707 mm, p value of < 0.001). There was no significant correlation between the diameter at T2 and stability or clinical scores and between the interval change ratio ([T2 - T1] / T1) and stability or clinical scores (corrected p values for all were 1.0). Intraobserver agreement for measurements was excellent (> 0.8) for both observers. Interobserver agreement for measurement was excellent (> 0.8) except for the most distal portion of the femoral bone tunnel for anterior medial bundle in immediate postoperative CT, which showed moderate agreement (concordance correlation coefficient = 0.6311).ConclusionNeither the diameter nor its change ratio during interval follow-up is correlated with stability or clinical scores.     

Ultrasound-Guided Percutaneous Removal of Wooden Foreign Bodies in the Extremities with Hydro-Dissection Technique

ObjectiveWe described the technique of ultrasound (US)-guided percutaneous removal of the foreign bodies (FB) with hydro-dissection in the radiologic department and presented video files of several cases.ResultsThe mean time required for the entire procedure was approximately 20 minutes. There were no significant complications during the US-guided removal or long-term complications after the procedure. All 4 FBs were successfully removed from the soft tissue under US guidance.ConclusionUltrasound-guided percutaneous removal of the FBs with hydro-dissection in the radiology department is a less invasive and safe method over surgical removal in the operating room. Additionally, the use of a guide wire and serial dilator may help minimize soft tissue injury and facilitate the introduction of forceps.     

Weight loss may be a better approach for managing musculoskeletal conditions than increasing muscle mass and strength

To prevent or remedy musculoskeletal conditions, the relationship between obesity and the characteristics of muscle mass and strength need to be clarified. [Subjects and Methods] A total of 259 Japanese males aged 30–64 years were classified into 4 groups according to the Japanese obesity criteria. Body composition was evaluated, and handgrip strength and knee extensor strength were measured for the upper and lower extremities, respectively. Physical performance was evaluated with a jump test. [Results] Obesity was positively correlated with skeletal muscle mass index, percentage of whole-body fat, and leg muscle strength and negatively correlated with the percentage of muscle mass index, body weight-normalized handgrip strength, and knee extensor strength, and the jump test results. [Conclusion] Weight loss may be a better approach than increasing muscle mass and strength to improve musculoskeletal conditions in obese adult males.Key words: Obesity, Muscle mass, Muscle strength     

Comparison of neck and upper-limb muscle activities between able-bodied and paraplegic individuals during wheelchair propulsion on the ground

[Purpose] This study compared the muscle activities of the neck and upper-limb muscles between able-bodied individuals and persons with paraplegia during wheelchair propulsion on the ground. [Subjects and Methods] The muscle activities of the neck and upper-limb muscles of 8 normal individuals and 8 individuals with paraplegia were analyzed during wheelchair propulsion. The activities of the latissimus dorsi, pectoralis major, anterior/posterior deltoids, triceps brachii, extensor carpi radialis, and sternocleidomastoid muscles were assessed. [Results] The paraplegic group showed significantly higher sternocleidomastoid activity than the normal group. Latissimus dorsi activity was also higher in the paraplegia group than in the normal group, but the difference was not significant. There were no significant differences in the other muscle activities between groups. [Conclusion] Paraplegic patients tend to use the sternocleidomastoid and latissimus dorsi muscles with greater degrees of activity. Therefore, physiotherapists should not overlook the treatment of these muscles for paraplegic patients who are long-term wheelchair users.Key words: Wheelchair propulsion, Muscle activities, Upper-limb muscle     

Crystal structure of a central stalk subunit C and reversible association/dissociation of vacuole-type ATPase

The vacuole-type ATPases (V-ATPases) exist in various intracellular compartments of eukaryotic cells to regulate physiological processes by controlling the acidic environment. The crystal structure of the subunit C of Thermus thermophilus V-ATPase, homologous to eukaryotic subunit d of V-ATPases, has been determined at 1.95-A resolution and located into the holoenzyme complex structure obtained by single particle analysis as suggested by the results of subunit cross-linking experiments. The result shows that V-ATPase is substantially longer than the related F-type ATPase, due to the insertion of subunit C between the V(1) (soluble) and the V(o) (membrane bound) domains. Subunit C, attached to the V(o) domain, seems to have a socket like function in attaching the central-stalk subunits of the V(1) domain. This architecture seems essential for the reversible association/dissociation of the V(1) and the V(o) domains, unique for V-ATPase activity regulation.     

Ghrelin enhances the proliferating effect of thyroid stimulating hormone in FRTL-5 thyroid cells

Ghrelin regulates cell proliferation through the growth hormone secretagogue receptor (GHS-R). We confirmed the expression of GHS-R in FRTL-5 thyroid cells and investigated the effects of ghrelin in thyrocytes using FRTL-5 cells. Ghrelin increased intracellular calcium levels but not intracellular cyclic AMP levels. Ghrelin activated Erk within 2min, then activated Akt and STAT3. Erk phosphorylation was inhibited by the calcium inhibitor cyclopiazonic acid (CPA). Ghrelin alone did not stimulate FRTL-5 cell proliferation but enhanced the effects of thyroid stimulating hormone (TSH). Pretreatment with TSH potentiates the growth effects of ghrelin in thyroid cells, and p66Shc, a growth factor receptor adaptor protein, might mediate these synergistic effects. Ghrelin phosphorylated TSH-induced p66Shc, which was inhibited by CPA. Ghrelin did not affect the proliferation of ARO cells, which showed no increased expression of p66Shc after TSH treatment. Thus, ghrelin-induced intracellular calcium signaling enhanced the TSH-induced proliferation of thyrocytes, possibly mediated by the p66Shc pathway.     

Sec63 and Xbp1 regulate IRE1α activity and polycystic disease severity

The HSP40 cochaperone SEC63 is associated with the SEC61 translocon complex in the ER. Mutations in the gene encoding SEC63 cause polycystic liver disease in humans; however, it is not clear how altered SEC63 influences disease manifestations. In mice, loss of SEC63 induces cyst formation both in liver and kidney as the result of reduced polycystin-1 (PC1). Here we report that inactivation of SEC63 induces an unfolded protein response (UPR) pathway that is protective against cyst formation. Specifically, using murine genetic models, we determined that SEC63 deficiency selectively activates the IRE1α-XBP1 branch of UPR and that SEC63 exists in a complex with PC1. Concomitant inactivation of both SEC63 and XBP1 exacerbated the polycystic kidney phenotype in mice by markedly suppressing cleavage at the G protein–coupled receptor proteolysis site (GPS) in PC1. Enforced expression of spliced XBP1 (XBP1s) enhanced GPS cleavage of PC1 in SEC63-deficient cells, and XBP1 overexpression in vivo ameliorated cystic disease in a murine model with reduced PC1 function that is unrelated to SEC63 inactivation. Collectively, the findings show that SEC63 function regulates IRE1α/XBP1 activation, SEC63 and XBP1 are required for GPS cleavage and maturation of PC1, and activation of XBP1 can protect against polycystic disease in the setting of impaired biogenesis of PC1.