Obtaining Adequate Tension for Extensor Hallucis Longus Tendon Rupture Repair Using Wide-Awake Surgery: A Case Report.

Wide-awake surgery has potential advantages for treating extensor or flexor tendon injury. We present a case of chronic extensor hallucis longus injury treated with turn-down reconstruction using wide-awake surgery with a selective nerve block. To the best of our knowledge, this is the first such case reported. The patient had dropped a knife proximal to the right hallux metatarsophalangeal joint. Because direct suturing was thought to be difficult, turn-down reconstruction was performed under a selective nerve block. At 8 months postoperatively, the hallux had 75° of extension in the metatarsophalangeal joint and -5° of extension in the interphalangeal joint, similar to those of the healthy foot. The Japanese Society for Surgery of the foot objective hallux scale score had improved from 87 to 100, and the subjective scores in the subcategories of pain and pain-related, physical functioning and daily living, and shoe-related in the self-administered foot evaluation questionnaire had improved from 82.8 to 94.4, 97.7 to 100, and 50 to 83.3, respectively. Turn-down reconstruction using wide-awake surgery with a selective nerve block can be used for chronic extensor hallucis longus rupture and can be expected to provide good results.

Involvement of Zizimin2/3 in the age-related defect of peritoneal B-1a cells as a source of anti-bacterial IgM.

Zizimin2 (Ziz2), also known as dedicator of cytokinesis 11 (DOCK11), is a guanine nucleotide exchange factor that is predominantly expressed in lymphoid tissues. Recent findings demonstrated that Ziz2 is involved in the development of B cells, including germinal centre B cells and marginal zone B cells. However, limited information is currently available on the roles of Ziz2 in B-1 cells, a B-cell subset that resides in body cavities and contributes to protection against foreign pathogens in a T-cell-independent manner. We herein show that Ziz2 and its widely expressed isoform Ziz3 (also known as DOCK10) may be involved in defective production of anti-bacterial IgM by aged B-1a cells, a CD5+ subset of B-1 cells. Natural IgM against typical bacterial epitopes was defectively produced by peritoneal B-1a cells from aged mice. The down-regulation of Ziz2/3 in B-1a cells appeared to be responsible for this defective IgM production, as demonstrated by Ziz2/3 double-knockout mice. Mechanistically, lower levels of basal AKT phosphorylation did not allow for the differentiation of Ziz2/3-deficient B-1a cells into plasma cells. Defective production of anti-bacterial IgM was not fully rescued by immunization, resulting in slightly weaker protection in Ziz2/3-deficient mice. Thus, the down-regulation of Ziz2/3 in B-1a cells may at least partly account for defective protection in aged mice.

An Alumina Ceramic Total Talar Prosthesis for Osteonecrosis of the Talus.

BACKGROUND: Treatment of osteonecrosis of the talus is challenging. Total talar replacement has the potential to restore the function of the ankle joint without an associated leg-length discrepancy. The purpose of the present study was to investigate postoperative function and pain after total talar replacement in patients with osteonecrosis of the talus. METHODS: Fifty-five ankles in fifty-one consecutive patients with osteonecrosis of the talus who were treated with a total talar replacement from 2005 to 2012 were included in the investigation. Scores according to the Japanese Society for Surgery of the Foot (JSSF) ankle-hindfoot scale and the Ankle Osteoarthritis Scale (AOS) were assessed before surgery and at the final follow-up evaluation. RESULTS: According to the JSSF ankle-hindfoot scale, the score for pain improved from a mean (and standard deviation) of 15 ± 9.4 points (range, 0 to 20 points) to 34 ± 5.6 points (range, 20 to 40 points); the score for function, from 21.2 ± 9.7 points (range, 4 to 38 points) to 45.1 ± 4.0 points (range, 37 to 50 points); the score for alignment, from 6.0 ± 2.8 points (range, 5 to 10 points) to 9.8 ± 0.9 points (range, 5 to 10 points); and the total score, from 43.1 ± 17.0 points (range, 11 to 68 points) to 89.4 ± 8.4 points (range, 76 to 100 points). According to the AOS scale, the score for "pain at its worst" improved from a mean of 6.1 ± 3.3 points (range, 0 to 9.9 points) to 2.0 ± 1.7 points (range, 0 to 6.3 points). CONCLUSIONS: Prosthetic talar replacement is a useful procedure for patients with osteonecrosis of the talus as it maintains ankle function.

The immunosenescence-related gene Zizimin2 is associated with early bone marrow B cell development and marginal zone B cell formation.

We originally cloned and identified murine Zizimin2 (Ziz2, Dock11) as a guanine nucleotide exchange factor (GEF) for Cdc42 and demonstrated that it activated the formation of filopodia. Since its expression pattern is restricted in immune tissues and Rho GTPases such as Cdc42 function in B cell development and immune responses, we expected Ziz2 to also be associated with B cell development and immune responses. However, the function of Ziz2 has not yet been fully examined in vivo. We also recently discovered that Ziz2 expression levels in immune tissues were reduced with aging in the mouse, suggesting that its expression is also associated with the mechanisms of immuno-senescence. To gain insights into the mechanisms underlying immuno-senescence, we generated Ziz2 knock out (KO) mice and examined the functions of Ziz2 in B cell development and immune responses. We also obtained Zizimin3 (Ziz3; Dock10) KO mice and examined the functions of Ziz3. The results revealed that Ziz2 KO mice had a higher percentage of early bone marrow B cells (Fraction A), but a reduced fraction of marginal zone (MZ) B cells. In addition, an examination of B cell-specific Ziz2 KO mice revealed that Ziz2 was intrinsically required for MZ B cell development, but not for mature follicular B cells. However, immune responses against NP-CGG (T cell-dependent), TNP-LPS (T cell-independent, TI, type I), and TNP-Ficoll (TI, type II) were not altered in KO mice. We finally demonstrated that CD1d-positive MZ B cell region outside CD169-positive marginal metallophilic macrophages (MMM) was narrowed in Ziz2 KO mice. Furthermore, MMM morphology appeared to be altered in Ziz2 KO mice. In conclusion, we herein showed that Ziz2 was associated with early bone marrow B cell development, MZ B cell formation, MZ B number/localization around MZ, and MMM morphology which may explain in part the mechanism underlying immuno-senescence.

Human cardiac stem cells with reduced notch signaling show enhanced therapeutic potential in a rat acute infarction model.

BACKGROUND: Because human cardiac stem cells (CSC) have regeneration potential in damaged cardiac tissue, there is increasing interest in using them in cell-based therapies for cardiac failure. However, culture conditions, by which CSCs are expanded while maintaining their therapeutic potential, have not been optimized. We hypothesized that the plating cell-density would affect proliferation activity, differentiation and therapeutic potential of CSCs through the Notch signaling pathway. METHODS AND RESULTS: Human CSCs were plated at 4 different densities. The population doubling time, C-KIT positivity, and dexamethasone-induced multidifferentiation potential were examined in vitro. The therapeutic potential of CSCs was assessed by transplanting them into a rat acute myocardial infarction (AMI) model. The low plating density (340cells/cm(2)) maintained the multidifferentiation potential with greater proliferation activity and C-KIT positivity in vitro. On the other hand, the high plating density (5,500cells/cm(2)) induced autonomous differentiation into endothelial cells by activating Notch signaling in vitro. CSCs cultured at low or high density with Notch signal inhibitor showed significantly greater therapeutic potential in vivo compared with those cultured at high density. CONCLUSIONS: CSCs cultured with reduced Notch signaling showed better cardiomyogenic differentiation and therapeutic potentials in a rat AMI model. Thus, reducing Notch signaling is important when culturing CSCs for clinical applications.

Rhof promotes murine marginal zone B cell development.

RhoF is a member of the Rho GTPase family that has been implicated in various cell functions including long filopodia formation, adhesion, and migration of cells. Although RhoF is expressed in lymphoid tissues, the roles of RhoF in B cell development remain largely unclear. On the other hand, other members of the Rho GTPase family, such as Cdc42, RhoA, and Rac, have been intensively studied and are known to be required for B cell development in the bone marrow and spleen. We hypothesized that RhoF is also involved in B cell development. To examine our hypothesis, we analyzed B cell development in RhoF knockout (KO) mice and found a significant reduction in marginal zone (MZ) B cells in the spleen, although T cell development in the thymus and spleen was not affected. Consistent with these results, the width of the MZ B cell region in the spleen was significantly reduced in the RhoF KO mice. However, the antigen-specific antibody titer of IgM and IgG3 after MZ B cell-specific antigen (T cell-independent antigen, type I) stimulation was not affected by RhoF deletion. Furthermore, we demonstrated that RhoF was dispensable for stromal cell-derived factor-1α- and B lymphocyte chemoattractant-induced B cell migration. These results suggest that RhoF promotes MZ B cell development in the spleen.

Identification of mouse colony-forming endothelial progenitor cells for postnatal neovascularization: a novel insight highlighted by new mouse colony-forming assay.

INTRODUCTION: Endothelial progenitor cells (EPCs) play a critical role in restoration of ischemic diseases. However, the actual status of EPC development and the mechanisms of EPC dysfunctions in patients with various ischemic diseases remain unknown. METHODS: To investigate the detailed function of EPCs in experimental murine models, we have established an EPC colony forming assay (EPC-CFA) in murine EPCs. The abilities of murine EPCs in differentiation, adhesive capacity, proliferative potency, and transplantation in vitro and in vivo were then examined. RESULTS: Peripheral blood mononuclear cells (PB-MNCs), bone marrow mononuclear cells (BM-MNCs) or bone marrow c-Kit+/Sca-1+ lineage negative (BM-KSL) cells differentiated into two types of EPC colony forming units (EPC-CFUs), large sized EPC (large-EPC)-CFUs and small sized EPC (small-EPC)-CFUs. Gene expression analysis demonstrated that both EPC-CFU-derived cells expressed eNOS, Flk-1 and VE-cadherin, markers of endothelial cells (ECs), although the small-EPCs derived from small-EPC-CFU were higher in number and showed more immature features (higher population of KSL cells). Functionally, the large-EPCs derived from large-EPC-CFU had higher adhesive capacity but lower proliferative potency than small-EPCs, showing improved tubular forming capacity and incorporation potency into primary EC-derived tube formation. Importantly, hindlimb ischemia increased the frequencies of large-EPC-CFUs differentiated from PB-MNCs and bone marrow. Actually, transplantation of large-EPCs into ischemic hindlimb enhanced neovascularization in hindlimb ischemia model, although small-EPCs or murine ECs did not, suggesting that large-EPC-CFUs might play an important role in restoration of ischemic diseases. CONCLUSIONS: We demonstrated, using a murine ischemia model, that the EPC-CFA could be a useful way to investigate the differentiation levels of murine EPCs, further providing a crucial clue that large-EPC-CFU status may be more functional or effective EPCs to promote neovascularization.

Impact of cardiac stem cell sheet transplantation on myocardial infarction.

PURPOSE: Myocardial infarction (MI) remains a major cause of mortality because of the limited regenerative capacity of the myocardium. Transplantation of somatic tissue-derived cells into the heart has been shown to enhance the endogenous healing process, but the magnitude of its therapeutic effects is dependent upon the cell-source or cell-delivery method. We investigated the therapeutic effects of C-Kit positive cardiac cell (CSC) cell-sheet transplantation therapy in a rat model of MI. METHODS AND RESULTS: CSCs of human origin were sorted and cultured to generate scaffold-free CSC cell-sheets. One-layered or 3-layered cell-sheets were transplanted into nude rats 1 h after left coronary artery ligation. We observed a significant increase in the left ventricular ejection fraction and a significant decrease in left ventricular systolic dimension at 2 and 4 weeks in the 3-layer group, but not in the 1-layer or sham groups. Consistently, there was less accumulation of interstitial fibrosis in the 3-layer group than in the 1-layer or sham groups. Moreover, capillary density was significantly greater in the 3-layer group than in the 1-layer or sham groups. CONCLUSIONS: The 3-layered cell-sheet improved cardiac function associated with angiogenic and anti-fibrotic effects. Thus, CSC is a promising cell-source to use with the cell-sheet method for the treatment of cardiac failure, as long as a sufficient number of cells are delivered.

Restricted expression of new guanine nucleotide exchange factor Zizimin2 in aged acquired immune system.

The activity of various biological functions, such as nervous, endocrine and immune systems including acquired immunity, is known to decline along with aging. To elucidate the molecular mechanism of this phenomenon, we here compared the number of thymocytes, splenocytes, and bone marrow lymphocytes in young and aged mice and found the age-related functional fragility of the immune system. However, the molecular mechanisms or even the key molecules remain elusive. Therefore, we further focused on a candidate for immunosenesence-related molecules, Zizimin2, which we have recently isolated and identified as a novel guanine nucleotide exchange factor that is highly expressed in murine splenic germinal center B cells after immunization with a T cell-dependent antigen. Here, we showed that endogenous Zizimin2 protein as well as mRNA expression levels in immune organs are strictly suppressed in aged mice. We further observed that the serum antigen specific antibody response is hampered in aged mice compared to that in young animals. Moreover, the Zizimin2 mRNA expression level was not activated after immunization in aged mice. Taken together, these data suggested that Zizimin2 is associated with the reduction of immune response in acquired immunity along with aging.

Arthroscopic ankle arthrodesis for hemophilic arthropathy: two cases report.

In the second decade of life, the ankle joint can be considered as the most common site for haemophilic arthropathy. To the best of our knowledge, no detailed reports have been published regarding arthroscopic ankle arthrodesis with haemophilic arthropathy. The aim of this paper is to report the outcomes of arthroscopic ankle arthrodesis in haemophilic arthropathy of the hindfoot. We performed three arthroscopic ankle arthrodeses in two patients. Case 1 was a 26-year-old man and case 2 was a 25-year-old man. The follow-up periods ranged from 2 year and 4 months to 6 years and one month. Union was obtained in all three ankles. All the arthroscopic ankle arthrodeses stopped or significantly reduced recurrent joint bleeding. With our procedure, we achieved pain relief and walking ability improvement. The mean American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot scale scores were 39 (range: 32-52) points preoperatively and 80 (range: 74-92) points postoperatively. Our cases achieved high satisfaction levels with pain relief and minimal complications for arthroscopic ankle arthrodesis, and case 2 who originally underwent arthroscopic arthrodesis of the left ankle demanded the same operation for his right ankle. We consider that arthroscopic ankle arthrodesis is an effective technique for haemophilic arthropathy.

Repair process after fibrocartilaginous enthesis drilling: histological study in a rabbit model.

BACKGROUND: Disorders of the enthesis are often a consequence of sports injuries. However, there is uncertainty regarding the process of mechanical stress-related injuries at the enthesis and the subsequent repair process of the injured tissues. To elucidate the repair process of the fibrocartilaginous enthesis, we studied the repair of injured fibrocartilaginous enthesis and the morphological characteristics of the repaired tissue. METHODS: We drilled 0.5-mm holes in the right tibial insertion of the patellar tendon of Japanese white rabbits, with their own left sides serving as controls. Specimens harvested at 1, 2, 4, 6, 8, and 12 weeks were examined histologically. Morphologically, the ratios of calcified fibrocartilage-bone interface lengths to enthesial lengths were compared between the control and surgical groups. RESULTS: Repair initiation was observed in the deep bone layer at 1 week, with remarkable progress at 2 weeks. Repair at the enthesis and neoosteogenesis in deep bone layers were detected at 4 weeks, and the drill hole disappeared at 6 weeks. The tendon was partially invaded by fibrocartilage-covered chondroid bone at 8 weeks, and regenerated fibrocartilaginous enthesis and increased calcified fibrocartilage-bone interface irregularity was identified at 12 weeks. The ratios of calcified fibrocartilage-bone interface lengths to enthesial lengths were significantly greater in the surgical group than in the control group. CONCLUSIONS: Repair progressed from bone to fibrocartilage and ended at fibrous tissue. Cancellous bone disruption triggered repair in all layers. Removal of the subchondral plate enabled infiltration of nutrients via blood vessels, with the underlying bone acting as a scaffold for the regenerating fibrocartilage.