Conditional deficiency of Rho-associated kinases disrupts endothelial cell junctions and impairs respiratory function in adult mice.

The Ras homology (Rho) family of GTPases serves various functions, including promotion of cell migration, adhesion, and transcription, through activation of effector molecule targets. One such pair of effectors, the Rho-associated coiled-coil kinases (ROCK1 and ROCK2), induce reorganization of actin cytoskeleton and focal adhesion through substrate phosphorylation. Studies on ROCK knockout mice have confirmed that ROCK proteins are essential for embryonic development, but their physiological functions in adult mice remain unknown. In this study, we aimed to examine the roles of ROCK1 and ROCK2 proteins in normal adult mice. Tamoxifen (TAM)-inducible ROCK1 and ROCK2 single and double knockout mice (ROCK1flox/flox and/or ROCK2flox/flox;Ubc-CreERT2) were generated and administered a 5-day course of TAM. No deaths occurred in either of the single knockout strains, whereas all of the ROCK1/ROCK2 double conditional knockout mice (DcKO) had died by Day 11 following the TAM course. DcKO mice exhibited increased lung tissue vascular permeability, thickening of alveolar walls, and a decrease in percutaneous oxygen saturation compared with noninducible ROCK1/ROCK2 double-floxed control mice. On Day 3 post-TAM, there was a decrease in phalloidin staining in the lungs in DcKO mice. On Day 5 post-TAM, immunohistochemical analysis also revealed reduced staining for vascular endothelial (VE)-cadherin, ß-catenin, and p120-catenin at cell-cell contact sites in vascular endothelial cells in DcKO mice. Additionally, VE-cadherin/ß-catenin complexes were decreased in DcKO mice, indicating that ROCK proteins play a crucial role in maintaining lung function by regulating cell-cell adhesion.

Measures for food allergy emergency in nurseries.

Background: As food allergy potentially can induce life-threatening anaphylaxis, measures for food allergy are required at nurseries caring for food allergy children, but a large-scale factual investigation has not been carried out. Objective: We evaluated measures for food allergy emergency in nurseries. Methods: A questionnaire survey regarding emergency measures in all authorized nurseries (411 facilities including 20,586 children) was conducted in Kawasaki city, Japan. Results: The recovery rate of the questionnaire was 46.5%, which include 14,343 children of 191 facilities in total. A total of 637 children (4.4%) in 157 facilities (82.2%) requires elimination diets that were suggested by physicians. Among them, 22 children had been suggested to undergo the use of epinephrine auto-injection kit for emergency. 161 facilities (84.3%) had set a specific manual for emergency of food allergy. Emergency cases over the past one year were 4 cases and there was no case that had been suggested to use epinephrine auto-injection kit. All were anaphylaxis and the causes of these included 2 accidental digestion of culprit foods and the causes of other 2 cases were unknown. A case who required no elimination diet showed first episode of anaphylaxis. All cases were recovered. Conclusion: High percentage of nurseries in Kawasaki city has cared for food allergy children. While many children with food allergy have been in nurseries, only several cases of anaphylaxis have been reported for a 1 year. Among 4 cases of anaphylaxis, no specific cause has been recognized in 2 cases and 1 case has been the first episode of anaphylaxis. While most of nurseries have set specific measures for emergency of food allergy, there is certain possibility that nursery staffs can encounter the first episode of anaphylaxis even if there is no food allergy child. For all nurseries, emergency measures for food allergy are vital.

Poor utility of serum interleukin-6 levels to predict indolent periprosthetic shoulder infections.

BACKGROUND: Infection after shoulder arthroplasty can present a diagnostic challenge. The purpose of this study was to evaluate the utility of serum interleukin-6 (IL-6) levels in diagnosis of periprosthetic infection in patients undergoing revision shoulder arthroplasty. METHODS: We prospectively enrolled 69 patients who underwent revision shoulder arthroplasty at one institution. All patients underwent a standard preoperative and intraoperative workup for infection, which included shoulder aspirate culture, erythrocyte sedimentation rate, C-reactive protein level, tissue culture, and frozen section analysis. In addition, serum levels of IL-6 were measured preoperatively in all patients. Infection classification was divided into 4 groups, (1) definite, (2) probable, (3) possible, and (4) no infection, on the basis of previously reported criteria using intraoperative cultures and preoperative and intraoperative findings of infections. RESULTS: Of the 69 patients, 24 were classified as having a definite or probable infection. Propionibacterium acnes was the offending organism for the majority of these cases (20 of 24, 83%). IL-6 was not a sensitive marker of infection for these patients (sensitivity: 3 of 24, 12%; specificity: 3 of 45, 93%). The sensitivity of serum IL-6 was lower compared with erythrocyte sedimentation rate (sensitivity: 10 of 24, 42%; specificity: 37 of 45, 82%) and C-reactive protein level (sensitivity: 11 of 24, 46%; specificity: 42 of 45, 93%). For the non-P. acnes cases (1 Staphylococcus aureus, 1 Enterobacter cloacae, 2 coagulase-negative Staphylococcus species), the sensitivity of IL-6 was 25% (1 of 4). CONCLUSION: Serum IL-6 is not an effective marker for diagnosis of infection in shoulder arthroplasty. On the basis of this large prospective study, we do not recommend its use as a preoperative diagnostic test in patients undergoing revision shoulder arthroplasty.

The Role of the Pathologist in Diagnosing Periprosthetic Infection.

Most patients who undergo total joint arthroplasty experience dramatic relief of pain and improved ambulation for many years, but some eventually develop pain, often accompanied by radiographic evidence of bone resorption around their implants. The most frequent cause of device failure is osteolysis, but infection is another important cause of pain and arthroplasty failure. The distinction between infection and aseptic loosening is important because the 2 conditions are treated very differently. The purpose of this article is to summarize the role of the anatomic and clinical pathologist in helping distinguish aseptic loosening from infection.

Biomechanical and histological evaluations of the doubled semitendinosus tendon autograft after anterior cruciate ligament reconstruction in sheep.

BACKGROUND: A sheep or goat anterior cruciate ligament (ACL) reconstruction model with the semitendinosus tendon autograft has not as of yet been established. HYPOTHESIS: The semitendinosus tendon graft may be necrotized after ACL reconstruction until 12 weeks. Structural properties of the femur-graft-tibia complex may not be restored to the normal ACL level even at 12 months after surgery. STUDY DESIGN: Controlled laboratory study. METHODS: Thirty-eight mature sheep were used. In each animal, the right knee underwent ACL reconstruction using the semitendinosus tendon autograft. Two of them were not tested because of pneumonia. Twenty of 36 sheep were used for biomechanical evaluations. Five randomly selected animals were sacrificed at 0, 12, 24, or 52 weeks after surgery. In each animal, both the knees were harvested, and the left knee was used to obtain the control data. The remaining 16 sheep were used for histological evaluation. Two or 3 randomly selected animals were sacrificed at 0, 2, 6, 12, 24, or 52 weeks after surgery. RESULTS: The tendon graft was predominantly acellular at 2 weeks. Although cell infiltration increased at 6 weeks, the core portion remained necrotic even at 12 weeks. At 24 and 52 weeks, the necrotic lesion disappeared in the core portion. In each period, the anteroposterior translation of the reconstructed knee remained significantly greater than that of the control (P < .0001). At 52 weeks, the maximum load of the femur-graft-tibia complex was significantly lower than that of the femur-ACL-tibia complex (P < .0001), although there was no significant difference in the cell density, the tissue dimensions, the stiffness, and the elongation at failure between the 2 complexes. CONCLUSION: The sheep ACL reconstruction model showed predominant intrinsic fibroblast necrosis in the tendon autograft until 12 weeks. Although the structural properties of the femur-graft-tibia complex gradually improved, they were not completely restored to the femur-ACL-tibia complex level even at 52 weeks. CLINICAL RELEVANCE: Remodeling of the semitendinosus tendon autograft after ACL reconstruction is not different from that of the bone-tendon-bone graft. This study has suggested that vigorous activity should not be permitted for patients in the early periods after ACL reconstruction using semitendinosus tendon autografts, which are necrotized and weakened after surgery.

Gender-based differences in outcome after anatomic double-bundle anterior cruciate ligament reconstruction with hamstring tendon autografts.

BACKGROUND: Although previous studies suggested that female patients are predisposed to increase graft laxity compared with male patients after single-bundle anterior cruciate ligament reconstruction using autogenous hamstring tendons, there have been no studies specifically examining gender-based differences in outcome after anatomic double-bundle anterior cruciate ligament reconstruction with hamstring tendon autografts. HYPOTHESES: (1) Female patients have significantly smaller hamstring graft diameters than do men for anatomic double-bundle anterior cruciate ligament reconstruction surgery; (2) female patients will have increased graft laxity compared with male patients after anatomic double-bundle anterior cruciate ligament reconstruction using autogenous hamstring tendons. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: The consecutive 174 patients who underwent anatomic double-bundle anterior cruciate ligament reconstruction using autogenous hamstring tendons were enrolled. Of these patients, 49 women and 73 men were prospectively evaluated 2 years after surgery. RESULTS: The diameters for anteromedial and posterolateral grafts in the female group were significantly smaller than those in the male group. On Lachman testing, 98% of the female group and 97% of the male group were rated as negative. Regarding the pivot-shift test, 80% of the female group and 85% of the male group were rated as negative. No significant differences were found between the female and male groups in these tests. The average side-to-side differences in the KT-2000 knee ligament arthrometer values were 1.3 mm in the female group and 1.4 mm in the male group; this difference between females and males was not statistically significant. The average Lysholm scores were 96.7 points in the female group and 97.2 points in the male group. Thirty-five cases (73%) in the female group and 54 cases (74%) in the male group were graded as normal on the International Knee Documentation Committee (IKDC) evaluation. There were no significant differences in Lysholm score or IKDC evaluation between the female and male groups. CONCLUSION: The results of assessment for ligament laxity at the 2-year postoperative evaluation in the female group were approximately identical to those of the male group after anatomic double-bundle anterior cruciate ligament reconstruction using autogenous hamstring tendons. Therefore, the present study suggests that anatomic double-bundle anterior cruciate ligament reconstruction using autogenous hamstring tendons provides satisfactory knee stability to female patients as well as male patients.

Extramedullary hematopoiesis in unusual locations in hematologically compromised and noncompromised patients.

Extramedullary hematopoiesis (EMH) occurs as a compensatory reaction to an underlying hematologic abnormality. EMH is most commonly seen in the liver and spleen but rarely has been reported in other locations, as well. On rare occasions, EMH may mimic a neoplasm in hematologically noncompromised patients. In this report, we present three cases of EMH in unusual locations, two in the presacral soft tissue and one in the synovial lining of the knee joint. The patients with presacral masses had no hematologic abnormality. In all patients with EMH, imaging plays an important role in both localization of the lesion and guidance for the biopsy; when imaging results are correlated with histological findings, the diagnosis of EMH can be confirmed.

Local administration of autologous synovium-derived cells improve the structural properties of anterior cruciate ligament autograft reconstruction in sheep.

BACKGROUND: The structural properties of a tendon autograft deteriorate during the remodeling phase after anterior cruciate ligament (ACL) reconstruction. HYPOTHESIS: A local application of autologous synovium-derived cells cultured in medium supplemented with transforming growth factor ß (TGFß) may inhibit the deterioration of structural properties of the tendon graft after ACL reconstruction. STUDY DESIGN: Controlled laboratory study. METHODS: Fifty-two mature sheep were used. In each animal, the right knee underwent ACL reconstruction using the semitendinosus tendon autograft; then, the animals were divided into 5 groups of 10. No additional treatments were applied in group 1, whereas fibrin sealant was applied around the graft in group 2. In group 3, autologous synovium-derived cells cultured in standard medium were applied around the graft with fibrin sealant, whereas autologous synovium-derived cells cultured in TGFß-supplemented medium were applied with fibrin sealant in group 4. In group 5, fibrin sealant containing 20 ng of TGFß was applied around the graft. Each animal was sacrificed at 12 weeks after the surgery. In each group, 7 and 3 sheep were used for biomechanical and histologic evaluations, respectively. The remaining 2 sheep were used to confirm whether the applied cells infiltrated the graft at 1 week after surgery. RESULTS: Confocal microscope observations showed that the applied cells that were labeled before implantation infiltrated into the superficial portion of the graft at 1 week. Biomechanically, the maximum load and the stiffness of groups 4 and 5 were significantly greater than those of groups 1, 2, and 3. Histologically, necrotic lesions were observed in the core portion of the midsubstance in groups 1 and 2. In groups 3, 4, and 5, no necrotic lesions were found in the midsubstance. CONCLUSION: A local application of autologous synovium-derived cells cultured in TGFß-supplemented medium or a fibrin sealant containing TGFß significantly inhibits the natural deterioration of the structural properties of the tendon graft after ACL reconstruction. CLINICAL RELEVANCE: Administration of autologous synovium-derived cells cultured in TGFß-supplemented medium or TGFß and fibrin glue alone can be a potential cell-based therapy to prevent graft deterioration after transplantation or accelerate mechanical restoration of the deteriorated graft.

Opening wedge high tibial osteotomy affects both the lateral patellar tilt and patellar height.

In the current study, we evaluated changes in the patellofemoral joint indices in 49 knees from 39 patients (11 men and 28 women with a median age of 64 years; range 53-79) who had undergone an opening wedge high tibial osteotomy (OWHTO). Osteoarthritis had been diagnosed in 39 knees and osteonecrosis in the other 10 knees in this patient cohort. Radiographs showing anteroposterior and true lateral views of the knee joints while standing, and also skyline views while standing with a 30 degrees flexion, were taken both pre- and postoperatively. Radiographic assessments were then performed using the following five parameters: femorotibial angle (FTA), modified Blackburne-Peel ratio (mBP), tibial slope (TS), lateral patellar tilt (LPT), and lateral patellar shift (LPS). The average LPT decreased significantly from 7.4 degrees + or - 3.7 degrees to 5.2 degrees + or - 3.6 degrees (P < 0.01). Patients treated with a greater than 15 degrees correction showed a significantly bigger change in their LPT than those with corrections of 15 degrees or less. No statistical differences were found between the preoperative (10.2 + or - 4.5%) and postoperative (10.2 + or - 4.7%) LPS measurements. Changes in the radiographic parameters were also observed in the patellofemoral joint after OWHTO. It is unclear to what extent the postoperative patellar shift and tilt affects the long-term clinical outcomes but our current results suggest that OWHTO negatively affects the congruency of the patellofemoral joint and should not exceed a correction of 15 degrees .

One-stage anatomic double-bundle anterior and posterior cruciate ligament reconstruction using the autogenous hamstring tendons.

This is the first report of an anatomic double-bundle ACL and PCL reconstruction procedure with the autogenous hamstring tendons. We prepare two pairs of the doubled tendon grafts, to which a polyester tape and an Endobutton-CL are attached using our original technique at the tibial and femoral ends, respectively. Under arthroscopic and fluoroscopic observations, two tibial tunnels for PCL reconstruction are created so that they pass through the posteromedial and anterolateral bundle attachments, respectively. Then, we create two tibial tunnels for anatomic double-bundle ACL reconstruction so that each tunnel axis is aimed at a targeted point on the femoral condyle. Using the outside-in technique, two femoral tunnels for PCL reconstruction are created so that the tunnel outlets are located at the center of the anterolateral and posteromedial bundle attachments. Then, two femoral tunnels for anatomic double-bundle ACL reconstruction are created with the trans-tibial tunnel technique. After the two grafts have been placed for PCL reconstruction, the two grafts are placed for ACL reconstruction. After all the femoral graft ends are fixed, the knee joint is reduced to the full extension position, and then, the four tibial tape portions are simultaneously fixed with the turn-buckle stapling technique.

A predictive factor for acquiring an ideal lower limb realignment after opening-wedge high tibial osteotomy.

Obtaining a correct postoperative limb alignment is an important factor in achieving a successful clinical outcome after an opening-wedge high tibial osteotomy (OWHTO). To better predict some of the aspects that impact upon the clinical outcomes following this procedure, including postoperative correction loss and over correction, we examined the changes in the frontal plane of the lower limb in a cohort of patients who had undergone OWHTO using radiography. Forty-two knees from 33 patients (23 cases of osteoarthritis and 10 of osteonecrosis) underwent a valgus realignment OWHTO procedure and were radiographically assessed for changes that occurred pre- and post-surgery. The mean femorotibial angle (FTA) was found to be 182.1 +/- 2.0 degrees (12 +/- 2.0 anatomical varus angulation) preoperatively and 169.6 +/- 2.4 degrees (10.4 +/- 2.4 anatomical valgus angulation) postoperatively. These measurements thus revealed significant changes in the weight bearing line ratio (WBL), femoral axis angle (FA), tibial axis angle (TA), tibia plateau angle (TP), tibia vara angle (TV) and talar tilt angle (TT) following OWHTO. In contrast, no significant change was found in the weight bearing line angle (WBLA) after these treatments. To assess the relationship between the correction angle and these indexes, 42 knees were divided into the following three groups according to the postoperative FTA; a normal correction group (168 degrees < or = FTA < or = 172 degrees ), an over-correction group (FTA < 168 degrees ), and an under-correction group (FTA > 172 degrees ). There were significant differences in the delta angle [DA; calculated as (pre FTA - post FTA) - (pre TV - post TV)] among each group of patients. Our results thus indicate a negative correlation between the DA and preoperative TA (R(2) = 0.148, p < 0.05). Hence, given that the correction errors in our patients appear to negatively correlate with the preoperative TA, postoperative malalignments are likely to be predictable prior to surgery.

Clinical results and radiographical evaluation of opening wedge high tibial osteotomy for spontaneous osteonecrosis of the knee.

We evaluated the clinical outcomes, in terms of early weight bearing, of using opening wedge high tibial osteotomy (OWHTO) to treat spontaneous osteonecrosis of the medial femoral condyle of the knee (SONK) using TomoFix and artificial bone substitute. Damaged cartilage tissue was removed and drilling of the necrotic area followed by OWHTO was performed in 30 knees from 30 patients with an average age of 71 years (range 58-82) at the time of operation. Patients were allowed to undertake partial weight-bearing exercises 1 week after the osteotomy procedure, with all patients performing full weight-bearing exercise at 2 weeks post-surgery. The mean follow-up period was 40 months (range 24-62). All of the SONK patients could walk with a full weight-bearing load, using only a T-cane, at 2 weeks after undergoing OWHTO. Clinical assays, including the mean American Knee Society Score and Function Score, showed significant improvements from 51 to 93 points, and 58 to 93 points, respectively. Prior to surgery, the average femoro-tibial angle (FTA) during standing was 181 (1 degree anatomical varus) and had significantly changed to 170 (10 degrees valgus) at the time of follow-up. There were no cases of non-union, or implant failure in any of our patients. In addition, none of the patients could sit in the Japanese style prior to surgery, but 21 of 30 patients (70%) could do so after treatment. Arthroscopic findings could be observed in 24 out of 30 cases at implant removal. Necrotic area in each case was covered with fibrous cartilage-like tissue completely. Drilling of the necrotic area followed by OWHTO with TomoFix and artificial bone substitute is an effective treatment for SONK as it results in pain alleviation and regeneration of the fibrous cartilage tissue over the necrotic legion. In addition, an early weight-bearing exercise program is possible after this procedure and full weight-bearing can be achieved at two weeks after surgery.

Simultaneous anterior and posterior cruciate ligament reconstruction in chronic knee instabilities: surgical concepts and clinical outcome.

The purpose of this study was to evaluate the clinical results of simultaneous arthroscopically assisted reconstruction of anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) using autogenous tendon grafts in chronic knee injuries. Nineteen patients (17 men and 2 women) with chronic multi-ligamentous injuries underwent one-stage ACL and PCL reconstruction. ACL, PCL and medial collateral ligament were reconstructed in seven knees, and ACL, PCL and posterolateral structure were reconstructed in two knees. Function of the operated knee was evaluated according to the International Knee Documentation Committee (IKDC) and Lysholm scale. Anterior and posterior knee laxity was examined with a KT-2000 arthrometer. Eighteen of 19 patients were able to return for follow-up and were evaluated objectively and subjectively. The average patient age at surgery was 30.5 years, and the average postoperative follow-up was 3.5 years. No patients showed loss of knee extension more than 5 degrees , while three patients revealed loss of knee flexion more than 16 degrees . The mean postoperative total anterior-posterior side-to-side difference was 1.9 +/- 1.5 mm at 20 degrees and 2.1 +/- 1.9 mm at 70 degrees . The average of the Lysholm score was 95.1 points at the final follow-up. At the IKDC evaluation, three patients were grade A, 11 were grade B, 3 were grade C, and 1 patient was grade D. The results showed the effectiveness and safety of one-stage reconstruction of combined ligamentous injuries of the knee that can adequately restore satisfactory stability.