Skeletal muscle and bone marrow derived stromal cells: A comparison of tenocyte differentiation capabilities

This study investigated the comparative ability of bone marrow and skeletal muscle derived stromal cells (BMSCs and SMSCs) to express a tenocyte phenotype, and whether this expression could be augmented by growth and differentiation factor‐5 (GDF‐5). Tissue harvest was performed on the hind limbs of seven dogs. Stromal cells were isolated via serial expansion in culture. After four passages, tenogenesis was induced using either ascorbic acid alone or in conjunction with GDF‐5. CD44, tenomodulin, collagen I, and collagen III expression levels were compared for each culture condition at 7 and 14 days following induction. Immunohistochemistry (IHC) was performed to evaluate cell morphology and production of tenomodulin and collagen I. SMSCs and BMSCs were successfully isolated in culture. Following tenocytic induction, SMSCs demonstrated an increased mean relative expression of tenomodulin, collagen I, and collagen III at 14 days. BMSCs only showed increased mean relative expression of collagen I, and collagen III at 14 days. IHC revealed positive staining for tenomodulin and collagen I at 14 days for both cell types. The morphology of skeletal muscle derived stromal cells at 14 days had an organized appearance in contrast to the haphazard arrangement of the bone marrow derived cells. GDF‐5 did not affect gene expression, cell staining, or cell morphology significantly. Stromal cells from either bone marrow or skeletal muscle can be induced to increase expression of matrix genes; however, based on expression of tenomodulin and cell culture morphology SMSCs may be a more ideal candidate for tenocytic differentiation. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:1710–1718, 2012     

Anesthesia with sevoflurane and remifentanil under spontaneous respiration assisted with high‐frequency jet ventilation for tracheobronchial foreign body removal in 586 children

Background: Foreign body aspiration is a common life‐threatening event in young children. Tracheobronchial foreign body removal is usually performed by rigid tracheobronchoscopy under general anesthesia. Anesthetic and ventilation techniques vary greatly among anesthesiologists and institutions. In the present retrospective study, we report our anesthetic experience over 5 years. We describe complications and outcomes and analyze the clinical characteristics of anesthesia and ventilation. Methods: We retrospectively reviewed relevant clinical findings of 586 pediatric patients treated with rigid tracheobronchoscopy under general anesthesia. All procedures were performed under inhaled sevoflurane anesthesia combined with remifentanil infusion, with spontaneous respiration assisted by high‐frequency jet ventilation (HFJV) and topical airway anesthesia. Results: Among 586 patients, the foreign body was successfully removed by rigid tracheobronchoscopy in 558 patients, and no foreign body was found in 28 patients. Laryngospasm was observed during the procedure in five patients. Hypoxemia was observed in 15 patients (2.6%). No severe complications or deaths occurred. The mean operation time was 22 min and the average hospital stay was 2 days. Conclusion: Inhaled sevoflurane anesthesia combined with remifentanil infusion, with spontaneous respiration assisted by HFJV and topical airway anesthesia, is safe and effective for tracheobronchial foreign body removal.     

Laparoscopic live donor nephrectomy: Current practice and results of renal transplantation

Objective: In 2009, 1659 patients with end‐stage renal failure in Hong Kong were waiting for a renal transplant. The overall number of renal transplants carried out locally remains low, with an even lower number being live donor donations. Yet, live donor kidney transplantation yields results that are consistently superior to those of deceased donor kidney transplantation, and laparoscopic donor nephrectomy (LDN) is increasingly accepted worldwide as a safe and preferred surgical option. We aim to evaluate the outcome of LDN in our setting, and to compare with that of deceased donors in this retrospective review. Patients and Methods: A total of 12 patients received LDN over the study period of 2006–2009. Standard left transperitoneal LDN was carried out. Grafts including three with double vessels were prepared using the bench technique. The postoperative outcomes up to 1 year for both the donors and the recipients were studied. Contemporary results for the 47 deceased donor kidneys were studied and compared. Results: All donors had an eventful recovery. The operating time was 225.0 ± 67.4 min. The hospital stay was 5.6 ± 2.3 days. The recipient outcomes including hospital stay and creatinine levels at discharge and 1 year were 11 days, 121 umol/L and 116 umol/L, respectively. Specifically, no ureteric stricture or graft loss was noted at the 1‐year follow up. Recipient complications included haematoma (1 patient), renal artery stenosis (1 patient) and redo of vascular anastomosis (1 patient). In contrast, the deceased donor graft recipients had a hospital stay of 11 days, and creatinine levels of 205 umol/L on discharge and 205 umol/L at 1 year, respectively. The delayed graft function rates for the live donor and deceased donors group were 0% and 14.9%, whereas the 1‐year graft survival rates were 100% and 87.2% respectively. Conclusion: The results showed that the donor morbidity rate was low, as reflected by the short hospital stay. Also, the overall parameters of recipients were good. In particular, no ureteric stricture was noted, and graft survival was 100% at 1 year. Living donor kidney transplant program using the laparoscopic technique is a viable option to improve the pool of kidneys for transplantation.     

Clinical analysis of osteonecrosis of the femoral head induced by steroids

Objective: To explore the clinical characteristics of osteonecrosis of the femoral head (ONFH) induced by steroids. Methods: From January 2000 to October 2009, 497 hips in 270 cases of ONFH induced by steroids were studied. A questionnaire was administered when the patients were admitted; the questions concerned the underlying disease, duration of steroid usage, total dosage of steroid, incubation period (time interval between commencement of steroid therapy and onset of pain), severity of pain, location of initial complaint, primary diagnosis, time lag from onset of pain to final diagnosis and physical signs when admitted. The correlations between pain and Association Research Circulation Osseous (ARCO) stage, bone marrow edema (BME) and lesion size were analyzed. Results: The median of time between commencing steroid medication and developing ONFH for the 269 cases was 18 months (range, 2–384 months). 78.82% cases presented with pain within three years of steroid initiation, only 10.41% patients first complained of pain six or more years after commencing steroid therapy. Fifty‐six cases (20.82%) were misdiagnosed, lumbar disorders being the most frequent misdiagnoses. 79.29% of symptomatic hips presented with abnormal physical tests. Of 420 symptomatic hips, 166 hips were type C1, 223 hips type C2; 299 hips had collapsed; and there was BME in 209 hips. Conclusion: Most patients with ONFH induced by steroids complained of pain within 3 years of commencing steroid therapy. Pain was associated with lesion size, collapse and BME. Atypical location of pain, failure to perform a physical examination and MRI findings were the main causes of misdiagnoses.     

Identification of HLA‐DR4‐restricted immunogenic peptide derived from xenogenic porcine major histocompatibility complex class I molecule

Park C‐S, Kim K‐H, Im S‐A, Song S, Lee C‐K. Identification of HLA‐DR4‐restricted immunogenic peptide derived from xenogenic porcine major histocompatibility complex class I molecule. Xenotransplantation 2012; 19: 317–322. © 2012 John Wiley & Sons A/S. Abstract: Indirect recognition of xenoantigens has been implicated as the major mechanism underlying xenospecific CD4⁺ T‐cell activation in chronic rejection. We identified swine leukocyte antigen (SLA)‐derived immunogenic peptides that are presented in the context of human HLA‐DR4 molecules. The SLA class I‐derived peptides that bind HLA‐DRB1*0401, a representative of the DR4 supertype, were predicted using a computer‐assisted algorithm. The candidate peptides were synthesized, and their binding capacities to HLA‐DRB1*0401 were compared in a competitive ELISA using biotinylated hemagglutinin reporter peptides [HA_307‐319]. Peptide‐11 (LRSWTAADTAAQISK) was determined to exhibit the most potent binding capacity to HLA‐DRB1*0401 in vitro and thus selected for in vivo immunization. Immunization of HLA‐DRB1*0401‐transgenic mice with peptide‐11 elicited potent CD4⁺ Th1 responses. Peptide‐11 shares homology to α2 domains of three SLA‐1 alleles, six SLA‐2 alleles, and 14 SLA‐3 alleles. Thus, this study has important implications not only for the identification of an immunogenic indirect epitope shared by diverse SLA class I alleles, but also for the development of epitope‐specific immunoregulation strategies.     

大连市潜水员股骨头坏死发病率的流行病学调查报告

 目的 调查大连市潜水员股骨头坏死发病率。方法 对2010 年1 月至2010 年12 月所有大连市注册在职潜水员855 名进行统一体格检查, 填写调查表, 项目包括身高、体重、血压及髋关节检查。摄髋关节正位及蛙位X线片, 对具有髋部症状但X 线片未见异常者采用MR 检查, 确诊股骨头坏死。结果 调查期间股骨头坏死发病人数为68 例, 发病率为7.95%(68/855)。68 例股骨头坏死患者中Ficat I期12 例12 髋、 II期40 例47 髋、III期3 例3 髋、IV期13 例15 髋。大连市在职潜水员年龄18~55 岁, 平均(32.6±5.5)岁;股骨头坏死发病年龄主要集中于30~50 岁, 占总发病人数的83.82%(57/68), 各年龄组发病率差异有统计学意义。按学历统计发病率的结果为小学10.58%(38/359)、初中6.28%(28/446)、高中4.26%(2/47)、大学(0/3), 各组差异有统计学意义。按工龄统计发病率的结果为5 年内4.55%(20/440)、6~10 年9.69%(28/289)、11~15 年13.04%(12/92)、16~20 年21.05%(4/19)、20 年以上26.67%(4/15), 各组差异有统计学意义。按企业性质统计发病率的结果为个体11.88%(19/160), 私营企业8.41%(38/452), 国家企业4.53%(11/243)。结论 股骨头坏死在潜水员中有较高的发病率, 不同的工作条件、工作时间发病率差异较大。     

Surgical strategy for the management of sacral giant cell tumors: a 32-case series

Background contextSurgical treatment of sacral giant cell tumors (GCTs) is associated with a high rate of complications, and there is controversy over which type of surgical treatment is optimal.PurposeTo develop an optimal treatment strategy for sacral GCTs.Study design/settingRetrospective/academic medical center.Patient sampleA total of 32 patients (18 women and 14 men) with sacral GCT who underwent surgery between August 1996 and August 2008.Outcome measuresLocal recurrence rate, surgical margins, blood loss, sacral nerve root preservation, and complications.MethodsThe medical charts of 32 patients were reviewed.ResultsPatients underwent either wide resection (n=2), marginal resection (n=11), marginal resection plus curettage (n=12), or curettage alone (n=7). The curettage group and the wide resection group had the highest and lowest amounts of blood loss (4,500 vs. 1,300 mL, respectively). During follow-up (median, 42 months), 12 patients (37.5%) had local recurrence, including five of seven in the curettage group. The recurrence rate was significantly lower in the marginal excision group compared with that in the curettage group (18.2% vs. 71.4%, respectively; p=.049). Five patients had bladder dysfunction, and two patients had bowel dysfunction. Four patients who underwent marginal resection had lower limb dysfunction. Overall survival was 93.6%, and 2-year recurrence-free survival was 84.4%.ConclusionsChoosing an optimal surgical margin in the treatment of sacral GCTs is of great importance for local recurrence control and sacral nerve root preservation. Curettage alone should not be used to treat sacral GCT.     

Minimally invasive percutaneous osteosynthesis for proximal humeral shaft fractures with the PHILOS through the deltopectoral approach

Purpose

The aim of this study was to evaluate clinical outcomes and complications following minimally invasive plate osteosynthesis (MIPO) with the proximal humeral internal locking system (PHILOS) for treating proximal humeral shaft fracture through the deltopectoral approach.

Methods

Between November 2008 and March 2010, 74 patients with unilateral proximal humeral shaft fractures were treated using the MIPO technique with the PHILOS through the deltopectoral approach. Patients received an average follow-up of 16.9 (range, 12–24) months, and the final follow-up included anteroposterior and lateral imaging and recording of postoperative complications. The Constant–Murley shoulder score was used to evaluate function.

Results

No intraoperative complications occurred. Postoperative complications included subacromial impingement in four patients. There was no deep infection, neurovascular damage, breakage or implant loosening. All fractures united in an average time of 17.4 (15–25) weeks. In terms of function, the Constant–Murley score was 85.8 points on average (range, 67–100). The range of motion of the involved shoulder was satisfactory, and pain-free in 83.8 % of patients.

Conclusions

Using the MIPO technique with the PHILOS through the deltopectoral approach is a valid and safe method of treating proximal humeral shaft fractures.     

Differences between the Vastus Lateralis and Gastrocnemius Lateralis in the Assessment Ability of Breakpoints of Muscle Oxygenation for Aerobic Capacity Indices During an Incremental Cycling Exercise

In recent years, breakpoints (Bp) of muscle oxygenation have been measured in local muscles using near infrared spectroscopy (NIRS) to assess (predict) systemic aerobic capacity indices [lactate threshold (LT), gas exchange threshold (GET) and maximal oxygen uptake (VO_2peak)]. We investigated muscular differences in the assessment (predictive) ability of the Bp of muscle oxygenation for aerobic capacity indices during incremental cycling exercise on the aerobic capacity indices. Thirty-one active college students were recruited for an incremental cycling exercise test, during which NIRS muscle oxygenation in the vastus lateralis (VL) and gastrocnemius lateralis (GL), blood lactate concentration and cardiopulmonary variables were measured simultaneously in a multi-modality approach. A linear regression model was used to analyse the relationship between the Bp of the muscle oxygenation index (OI) and the systemic aerobic capacity indices. The Bp of the muscle OI in both the VL (BpVL) and GL (BpGL) were significantly correlated with the aerobic capacity indices. Additionally, the BpVL had a better goodness-of-fit [higher coefficient of determination (R², p < 0.001) and lower root mean squared error (RMSE, p < 0.03)] in the linear regressions and occurred earlier than the BpGL. In conclusion, both the BpVL and the BpGL could be measured by NIRS to assess the systemic aerobic capacity indices; however, there were muscular differences in the assessment ability of the Bp of muscle oxygenation.

Key points

• The breakpoints (Bp) of muscle oxygenation index in both vastus lateralis (VL) and gastrocnemius lateralis (GL) could be detected to indicate the breaking up of the oxygen supply-consumption balance by NIRS.
• The Bp of muscle oxygenation index in both VL (BpVL) and GL (BpGL) were significantly correlated with the systemic aerobic capacity indices.
• The BpVL owned higher assessment (predictive) ability when the Bp (BpVL and BpGL) of muscle oxygenation index was used to assess (predict) systemic aerobic capacity indices.

Key words: Maximal incremental exercise test, aerobic capacity index, assessment ability, near infrared spectroscopy, linear regression.