Activation of vascular protein kinase C-beta inhibits Akt-dependent endothelial nitric oxide synthase function in obesity-associated insulin resistance

Activation of protein kinase C (PKC) in vascular tissue is associated with endothelial dysfunction and insulin resistance. However, the effect of vascular PKC activation on insulin-stimulated endothelial nitric oxide (NO) synthase (eNOS) regulation has not been characterized in obesity-associated insulin resistance. Diacylglycerol (DAG) concentration and PKC activity were increased in the aorta of Zucker fatty compared with Zucker lean rats. Insulin-stimulated increases in Akt phosphorylation and cGMP concentration (a measure of NO bioavailability) after euglycemic-hyperinsulinemic clamp were blunted in the aorta of fatty compared with lean rats but were partly normalized after 2 weeks of treatment with the PKCbeta inhibitor ruboxistaurin (LY333531). In endothelial cell culture, overexpression of PKCbeta1 and -beta2, but not PKCalpha, -delta, or -zeta, decreased insulin-stimulated Akt phosphorylation and eNOS expression. Overexpression of PKCbeta1 and -beta2, but not PKCalpha or -delta, also decreased Akt phosphorylation stimulated by vascular endothelial growth factor (VEGF). In microvessels isolated from transgenic mice overexpressing PKCbeta2 only in vascular cells, Akt phosphorylation stimulated by insulin was decreased compared with wild-type mice. Thus, activation of PKCbeta in endothelial cells and vascular tissue inhibits Akt activation by insulin and VEGF, inhibits Akt-dependent eNOS regulation by insulin, and causes endothelial dysfunction in obesity-associated insulin resistance.     

Efficacy of 3-dimensional endorectal ultrasonography compared with conventional ultrasonography and computed tomography in preoperative rectal cancer staging

BACKGROUND: This study was performed to verify reports of the decreased accuracy of endorectal ultrasonography (EUS) in preoperative staging of rectal cancer, and to compare the efficacy of 3-dimensional (3D) EUS with that of 2-dimensional (2D) EUS and computed tomography (CT). METHODS: Eighty-six consecutive rectal cancer patients undergoing curative surgery were evaluated by 2D EUS, 3D EUS, and CT scan. RESULTS: The accuracy in T-staging was 78% for 3D EUS, 69% for 2D EUS, and 57% for CT (P < .001-.002), whereas the accuracy in evaluating lymph node metastases was 65%, 56%, and 53%, respectively (P < .001-.006). Examiner errors were the most frequent cause of misinterpretation, occurring in 47% of 2D EUS examinations and in 65% of 3D EUS examinations. By eliminating examiner errors, the accuracy rates in T-staging and lymph node evaluation could be improved to 88% and 76%, respectively, for 2D EUS, and to 91% and 90%, respectively, for 3D EUS. Conical protrusions along the deep tumor border on 3D images were correlated closely with infiltration grade, advanced T-stage, and lymph node metastasis. CONCLUSIONS: We found that 3D EUS showed greater accuracy than 2D EUS or CT in rectal cancer staging and lymph node metastases. Concrete 3D images based on tumor biology appear to provide more accurate information on tumor progression.     

Effect of Inner Taper Angle of Acetabular Metal Shell on the Malseating and Dissociation Force of Ceramic Liner

Background

Malseating of ceramic liner appeared as a matter of concern in multibearing metal, although multibearing cup can be coupled with hard liners as well as polyethylene liner. In this metal shell, the inner taper angle should be 10° for the modularity, while standard metal shells for ceramic liner have an inner taper angle of 18°. However, there has been no study in the effect of taper angle to the risk of malseating. We evaluated whether the taper angle of metal shell might affect the malseating of ceramic liner, and dissociation force of ceramic liner from metal shell.

A Novel Surgical Technique for Neglected Volar Dislocation of the Lunate: Cases Report and Literature Review

Background

Treatments for chronic perilunate or lunate dislocations are very difficult and associated with poor prognoses. There is no established treatment method and are still many controversies.

Case Presentation

We reported three cases of chronic neglected lunate volar dislocation treated with a novel surgical technique. All three cases were males with wrist pain and tingling sensation. Radiographs confirmed chronic volar dislocation of the lunate. Open reduction was performed by combined volar and dorsal approaches. After anatomical reduction, scapholunate and lunotriquetral interosseous ligament reconstructions were performed with the palmaris longus tendon and synthetic tape. The patients had an uneventful postoperative period with satisfactory functional outcomes at the last follow-up.

Conclusions

We believe that open reduction and interosseous ligament reconstruction using the autogenous tendon and synthetic tape may be a valuable option for treating chronic volar dislocation of the lunate.     

Arthroscopic physeal sparing all inside repair of the tibial avulsion fracture in the anterior cruciate ligament: technical note

We describe a new and effective arthroscopic physeal sparing repair of the tibial eminence avulsion fracture using all an inside repair technique. The treatment of ACL avulsion is controversial, especially in skeletally immature patients, with concerns about physeal damage, and a more reliable way of fixation is still being pursued for small or comminuted fragments. Screw fixation and suture cerclage has some limitations, especially in the small fragment or skeletally immature patients. We fixed avulsion fragment using all inside repair between the distal portion of the ACL and transverse ligament and periosteum. A crescent suture hook loaded with NO. 0 PDS is introduced and the suture hook pierces the transverse intermeniscal ligament and periosteum. The half length of the PDS is now advanced out through the hook and the end is brought out to the anterolateral portal. With the suture hook located intra-articularly and loaded with half the length of the original PDS, the suture hook repierces the transverse intermeniscal ligament at 5 mm on the side and the remaining half length of PDS is now advanced out through the hook and the end is brought out to the anterolateral portal. After that procedure, the suture hook loaded with NO. 0 absorbable Maxon is introduced through the anteromedial portal for the role of shuttle relay. The suture hook pierces the ACL just above the superior border of the avulsion fragment, the Maxon is now advanced out through the hook and the end is brought out to the anterolateral portal. Subsequently, the suture hook is removed and a suture retriever is introduced through the anterolateral portal. PDS and Maxon are held together and retrieved out of the anterolateral portal by the suture retriever at the same time. Our technique has advantages in small comminuted fractures and skeletally immature patients.     

Sirolimus inhibits platelet-derived growth factor-induced collagen synthesis in rat vascular smooth muscle cells

Vascular smooth muscle cell (VSMC) proliferation and extracellular matrix (ECM) accumulation play key roles in the development and the progression of vascular remodeling such as transplant arteriosclerosis and restenosis. The present study examined the effects of sirolimus (SRL) on platelet-derived growth factor (PDGF)-induced fibronectin secretion, collagen synthesis, and the related signaling pathways including reactive oxygen species (ROS) and mitogen-activated protein kinases (MAPK) in rat VSMCs. Primary rat VSMCs were isolated from male Sprague-Dawley rats. Growth arrested, synchronized cells were treated with various concentrations of SRL before the addition of PDGF at 10 ng/mL. Proliferating cell nuclear antigen expression, fibronectin secretion, and the activation of extracellular signal-regulated protein kinase (ERK) and p38 MAPK were assessed by Western blot analysis, collagen synthesis by [(3)H]-proline incorporation, and cellular ROS by flow cytometry. PDGF (10 ng/mL) increased VSMC proliferation by 1.7-fold, fibronectin secretion by 1.5-fold, collagen synthesis by 2.1-fold, cellular ROS by 1.6-fold, and activation of ERK and p38 MAPK by 3.3- and 3.9-fold compared to controls. SRL above 1 nmol/L inhibited PDGF-induced VSMC proliferation and collagen synthesis but not PDGF-induced fibronectin secretion, cellular ROS, and activation of ERK and p38 MAPK. These data demonstrated that PDGF increased ECM synthesis as well as proliferation through cellular ROS and subsequent MAPK activation and that SRL inhibited PDGF-induced VSMC proliferation and collagen synthesis in a cellular ROS- and MAPK activation-independent way.     

Effects of obesity on lower urinary tract symptoms in Korean BPH patients

We analyzed the effects of obesity on lower urinary tract symptoms （LUTSs） in Korean benign prostatic hyperplasia （BPH） patients. This is a multicenter, cross-sectional, prospective study conducted in four centers in Korea. A total of 602 men with LUTSs secondary to BPH were included. BPH/LUTSs cases were men aged ≥ 40 years with intemational prostate symptom scores （IPSS） ≥ 8 points. Height, weight and waist circumference were measured. Among the 602 patients, 156 patients had a waist circumference above 90 cm, representing central obesity, and 215 patients had a body mass index above 25 kg m2. Waist circumference was positively correlated with prostate volume （P = 0.034）. Men with waist circumference 〉 90 cm experienced a 1.36-fold increased risk of severe LUTSs （95% CI 0.82-2.41） compared with men with waist circumference ≤ 90 cm. Prostate volume was positively correlated with urgency and nocturia in men with central obesity. In this population of Korean men diagnosed with BPH, central obesity rather than overall obesity seems to be the more important predictor of LUTSs correlated with BPH.     

Posterolateral corner anatomy and its anatomical reconstruction with single fibula and double femoral sling method: anatomical study and surgical technique

This paper reports a novel method for reconstructing the posterolateral structures [lateral collateral ligament (LCL), popliteus tendon, popliteofibular ligament] based on an anatomical study of a cadaveric dissection. The popliteus tendon was found to always be attached to the anterior–inferior portion of the femoral attachment site of the LCL, and the average distance from the origin of the popliteal tendon in the femoral side to that of the LCL was 18.5 mm (17–20). The insertion site of the LCL in the fibular side was located anterior–inferior-superficially and the popliteofibular ligament was inserted into the posterior–superior-deep portion around the styloid process. Two femoral tunnels and one fibular head tunnel were made at the proximal and distal portion of the anatomical insertion sites.