Addition of a Vascular Bundle Accelerates Bone Union in Femoral Bone Defects.

BACKGROUND: The Masquelet method has become increasingly popular for the treatment of bone defects in recent years. In this method, an induced membrane (IM) with abundant blood circulation, stem cells, and osteogenesis-promoting factors is formed by implanting bone cement during the first surgery. This IM stimulates bone formation in the bone defect after implantation of the bone graft during the second surgery. However, the Masquelet method requires two surgeries and thus a longer treatment period. In the present study, we investigated whether bone defects could be reconstructed in a single surgery by introducing a vascular bundle into the bone defect as an alternative to the IM, in addition to bone grafting. METHODS: Thirty-six 12-week-old female Sprague-Dawley rats were used. After creating a 5-mm long bone defect in the femur, a mixture of autologous and artificial bone was grafted into the defect, and a saphenous arteriovenous vascular bundle was introduced. The animals were divided into three groups: the control group (bone defect only), the BG group (bone grafting only), and the BG + V group (bone grafting + vascular bundle introduction). After surgery, radiological and histological evaluations were performed to assess osteogenesis and angiogenesis in bone defects. RESULTS: In the BG + V group, significant bone formation was observed in the bone defect on radiological and histological evaluations, and the amount of bone formation was significantly higher than that in the other two groups. Furthermore, cortical bone continuity was observed in many specimens in the BG + V group. On histological evaluation, the number of blood vessels was also significantly higher in the BG + V group than in the other two groups. CONCLUSION: Our results suggest that the introduction of a vascular bundle in addition to bone grafting can promote bone formation in bone defects and allow for complete bone defect reconstruction in a single surgery.

Skin extension with a digito-lateral flap and early active finger extension training for Dupuytren contracture: A retrospective study.

In the surgical management of Dupuytren contracture (DC), Y-V plasty (YV) and Z-plasty (ZP) are techniques often used for skin extension. However, achieving sufficient skin extension with these procedures alone is often difficult. Therefore, we addressed this issue with an adjunctive digito-lateral flap (DLF) and report the clinical results of the surgery using a DLF in addition to YV and ZP. Fifteen patients with DC (15 affected fingers) underwent partial fasciectomy using a DLF in addition to YV or ZP, and early active finger extension training was performed immediately after the operation. The flap survival rate, preoperative and postoperative extension angle, Tonkin contracture improvement (TCI) rate, and Tubiana staging grades were evaluated. The contracture sites were at 4 proximal interphalangeal (PIP) and 3 metacarpophalangeal (MP) joints of the little finger and 4 PIP and MP joints each of the ring and little fingers. All the flaps survived, and the extension angle improved at the final observation from a preoperative mean of -45° to -3° and -55° to 5° for the PIP and MP joints, respectively. One patient with PIP joint contracture treated in the early stage of the study experienced a persistent 5° limitation of extension, even though the TCI rate was satisfactory (91.9%) and the outcome was "good." Full extension of the joints was achieved in 15 patients, in whom the TCI rate was 100% and the outcome was "very good." This technique was able to solve 3 important steps to achieve full extension: intraoperatively, wound closure, and rehabilitation. We attained and maintained long-term full extension intraoperatively and immediately after surgery and obtained very good treatment results, as shown in this study. In conclusion, highly favorable clinical outcomes were achieved through the combination of a DLF with YV and ZP. Skin extension with a DLF is a useful surgical technique for DC.

Postoperative early and proactive grip strength training program for distal radius fractures promotes earlier recovery of grip strength: A retrospective study.

ABSTRACT: The use of volar locking plates (VLPs) for distal radius fractures has remarkably improved clinical outcomes; however, there are some reports of delayed recovery of grip strength. Since January 2019, we have been conducting an early and proactive grip strength training program (EGTP). In this program, 20 minutes of grip strength training-using a gripper with a load of 0.7 kg-was initiated from 2 weeks after surgery; the load was then gradually increased. From 6 weeks postsurgery, daily home grip strength training was performed using a gripper with a load of 5 kg, provided to the patient.We investigated whether the introduction of the EGTP could lead to earlier recovery of grip strength. We also examined whether the EGTP caused postoperative correction loss at the fractured site, or contributed to the early improvement of wrist function.Thirty-nine patients who underwent surgery using VLPs for distal radius fractures were included in this study; 20 followed the EGTP (EGTP group) and 19 patients did not (NGTP group). For these patients, grip strength and range of motion of the wrist joint were evaluated both 3 and 6 months postoperatively. The Quick Disabilities of the Arm, Shoulder, and Hand (qDASH) scores were also evaluated 6 months postoperatively. Additionally, corrective losses of radial inclination (RI), palmar tilt (PT), and ulnar variance (UV)-occurring from immediately postsurgery to 6 months after surgery-were evaluated.At both 3 and 6 months postoperatively, the grip strength of the EGTP group was significantly higher than that of the NGTP group. Regarding range of motion, only palmar flexion was significantly improved in the EGTP group at 3 months postoperatively. Conversely, no differences in corrective losses of RI, PT, and UV, or in qDASH scores, were observed between the two groups.The results of this study suggest that the EGTP can provide early recovery of grip strength and palmar flexion of the wrist without causing corrective loss at the fracture site.

Lasso loop technique using bioabsorbable thread to treat intra-articular distal radius fracture.

ABSTRACT: This article introduces our lasso loop technique (LLT) using a bioabsorbable thread for the treatment of intra-articular distal radius fractures with displaced dorsal bone fragment containing articular surface (DBF). We also examined whether the articular gap is sufficiently reduced and maintained by the LLT, along with the results of other radiological and clinical evaluations. We retrospectively reviewed 19 patients who underwent LLT for intra-articular distal radius fracture with a displaced DBF. Patient radiographic images and medical records were used to investigate radiological characteristics, symptoms, physical findings, and the Quick Disabilities of the Arm, Shoulder, and Hand scores. Sagittal-view computed tomography showed that the mean preoperative articular gap was 2.6 mm, but the gap was reduced by LLT, and the gap immediately postoperatively was <1.0 mm in all patients. No re-displacement of the DBF was evident from immediately postoperatively to 6 months postoperatively. Postoperatively, no losses of correction in palmar tilt, radial inclination, or ulnar variance were seen in the evaluation of plain radiographs, and satisfactory joint range of motion, grip strength, and the Quick Disabilities of the Arm, Shoulder, and Hand score were obtained. No significant complications due to LLT were observed. LLT appears to offer a simple and effective procedure to reduce displaced DBF with little risk of complications. LLT may become a useful option in the treatment of intra-articular distal radius fractures with displaced DBF.

Combined administration of rifampicin, ethambutol, and clarithromycin for the treatment of tenosynovitis of the hand caused by Mycobacterium avium complex: Case series and literature review.

ABSTRACT: We report the clinical results and problems of combined administration of rifampicin, ethambutol, and clarithromycin (REC) for the treatment of Mycobacterium avium complex (MAC) infection of the hand (hand MAC).Participants included 7 patients with hand MAC. After resection of the infected lesion, REC was prescribed for 12 months. For these patients, the site of infection, clinical course after initiation of REC, adverse drug effects (ADEs), and incidence of recurrence were evaluated.Sites of infection were the flexor tenosynovium in 5 patients, extensor tenosynovium in 1 patient, and both flexor and extensor tenosynovium in 1 patient. ADEs of REC occurred in 5 patients, and included visual disturbance caused by ethambutol in 2 patients, liver function abnormality caused by rifampicin in 2 patients, and fever with diarrhea caused by rifampicin in 1 patient. For 2 of these 5 patients, desensitization therapy was applied and REC was able to be reinstated. In the remaining 3 patients, the causative drugs were discontinued and levofloxacin, a new quinolone, was administered. Complete healing was achieved in 5 patients, and recurrence was observed in 2 patients. These 2 patients with recurrence included 1 patient in whom REC was completed and 1 patient in whom REC therapy was modified due to ADE.REC provided relatively good clinical results as a treatment for hand MAC. However, recurrences were observed even after the completion of REC and the use of an alternative drug. Optimal duration of REC and appropriate alternative drugs need to be identified in the future.

Effects of VEGF on Prefabricated Vascularized Bone Allografts in Rats.

BACKGROUND: Massive bone defects after wide resection of malignant bone tumors or a serious injury require treatment using vascularized bone grafts. Although cadaveric bone allografts combined with vascularized bone autografts are currently thought to be ideal in terms of size and durability, this treatment requires the scarification of healthy bone tissue. In a previous study, we attempted to improve this situation by prefabricating a vascularized bone allograft in recipient rats. In this study, we added vascular endothelial growth factor (VEGF)-containing hydroxyapatite/collagen composite (HAp/Col) to a prefabricated vascularized bone allograft to stimulate angiogenesis, which is known to be important for bone formation. METHODS: Sprague Dawley rats (n = 50) were used as donors and Wistar rats (n = 50) as recipients. All rats were 9 weeks old. The recipient rats were divided into five groups according to the use of vascular bundles, HAp/Col, and an additive substance (VEGF). The bone allografts collected from the donors were transplanted into the thigh region of the recipients, and a saphenous vein and 10 µg HAp/Col with VEGF were inserted into the bone allografts through the slit. After 4 weeks, the transplanted bone allografts were harvested, and histologic and genetic evaluations were performed in relation to bone formation and resorption. RESULTS: The results showed that, compared with the control group, the implantation of the vascular bundles and VEGF-containing HAp/Col significantly stimulated angiogenesis and bone formation in the rats with the bone allografts. However, histological and genetic evaluations of bone resorption revealed that resorption was not observed in any group. CONCLUSION: These results suggest that VEGF-containing HAp/Col effectively stimulates angiogenesis and bone formation, but not bone resorption, in prefabricated vascularized bone allografts. This method could therefore become a useful tool for treating large bone defects.

Bone Union Enhancement by bFGF-Containing HAp/Col in Prefabricated Vascularized Allo-Bone Grafts.

BACKGROUND: We have developed a prefabricated vascularized allo-bone graft (PVAG) by implanting the saphenous vascular bundles of recipient rats into transplanted donor bones in a flow-through manner. We previously demonstrated that the angiogenetic and bone formative abilities of the PVAG are stimulated by the addition of a basic fibroblast growth factor (bFGF)-containing hydroxyapatite/collagen (HAp/Col). This study aimed to demonstrate that the bone union ability of the PVAG is similarly stimulated by the bFGF-containing HAp/Col composite. METHODS: Sprague-Dawley donor rats (n = 32) and Wistar recipient rats (n = 32) were used in this study. The PVAG was fixed to the femur of the recipient rat using K-wire (dimeter: 0.7 mm) pinning, followed by suturing with a 4-0 nylon suture. Recipients were divided into four groups: with or without vascular bundles, and with or without bFGF-containing HAp/Col. Rats were sacrificed 6 weeks after transplantation, and bone union, bone resorption, and angiogenesis were radiologically and histologically evaluated. RESULTS: Radiological analysis revealed a significant increase in callus formation and union rate, while histological analysis showed a significant increase in bone formation and angiogenesis in the group treated with both vascular bundles and bFGF. Bone resorption did not significantly increase in any of the evaluated groups. CONCLUSION: Osteogenic cells, osteoconductive scaffolds, growth factors, and mechanical environment are known to be important factors in the process of fracture healing. The PVAG developed herein contains osteogenic cells, osteoconductive scaffolds, and growth factors. In addition, the PVAG is rigidly fixed to the fracture site, providing a stable mechanical environment. Together, these four factors contributed to a good bone union. Furthermore, this method did not promote bone resorption. Thus, the addition of a vascular bundle and bFGF-containing HAp/Col makes it possible to create an ideal vascularized allo-bone graft for the reconstruction of massive bone defects.

Superconductivity in a Scandium Borocarbide with a Layered Crystal Structure.

The discovery of nearly room-temperature superconductivity in superhydrides has motivated further materials research for conventional superconductors. To realize the moderately high critical temperature (Tc) in materials containing light elements, we explored new superconducting phases in a scandium borocarbide system. Here, we report the observation of superconductivity in a new ternary Sc-B-C compound. The crystal structure, which was determined through a Rietveld analysis, belongs to tetragonal space group P4/ncc. By complementarily using the density functional theory calculations, a chemical formula of the compound was found to be expressed as Sc20C8-xBxC20 (x = 1 or 2). Interestingly, a small amount of B is essential to stabilize the present structure. Our experiments revealed the typical type-II superconductivity at Tc = 7.7 K. Additionally, we calculated the density of states within a first-principles approach and found that the contribution of the Sc-3d orbital was mainly responsible for the superconductivity.

Synthesis and Superconductivity of a Strontium Digermanide SrGe2-δ with ThSi2 Structure.

We have succeeded in crystallizing a new strontium digermanide (SrGe2-δ) with the ThSi2-type structure (tetragonal SrGe2), which is theoretically predicted to compete with the EuGe2-type one (trigonal SrGe2) under pressure. The tetragonal SrGe2 appeared as a metastable phase in samples at approximately 900 °C under a pressure of 2 GPa. X-ray diffraction studies show that the tetragonal SrGe2 is formed by the reaction between trigonal SrGe2 and excess Sr. The composition of the tetragonal SrGe2 was analyzed to be SrGe1.66(4). Lattice parameters for the tetragonal SrGe2 are determined to be a = 4.559(4) Å and c = 14.42(1) Å. The tetragonal SrGe2 shows metallic resistivity behavior and exhibits superconductivity with a critical temperature (Tc) of 7.3 K, which is the highest among compounds with the ThSi2-type structure. Superconducting properties of the tetragonal SrGe2, such as the upper critical field, and the effect of pressure on Tc, are presented and superconductivity is discussed on the basis of electronic band structure calculations.

Large enhancement of superconducting transition temperature of SrBi3 induced by Na substitution for Sr.

The Matthias rule, which is an empirical correlation between the superconducting transition temperature (Tc) and the average number of valence electrons per atom (n) in alloys and intermetallic compounds, has been used in the past as a guiding principle to search for new superconductors with higher Tc. The intermetallic compound SrBi3 (AuCu3 structure) exhibits a Tc of 5.6 K. An ab-initio electronic band structure calculation for SrBi3 predicted that Tc increases on decreasing the Fermi energy, i.e., on decreasing n, because of a steep increase in the density of states. In this study, we demonstrated that high-pressure (~ 3 GPa) and low-temperature ( < 350 °C) synthesis conditions enables the substitution of Na for about 40 at.% of Sr. With a consequent decrease in n, the Tc of (Sr,Na)Bi3 increases to 9.0 K. A new high-Tc peak is observed in the oscillatory dependence of Tc on n in compounds with the AuCu3 structure. We have shown that the oscillatory dependence of Tc is in good agreement with the band structure calculation. Our experiments reaffirm the importance of controlling the number of electrons in intermetallic compounds.

Crystal structure and superconductivity of BaIr2Ge7 and Ba3Ir4Ge16 with two-dimensional Ba-Ge networks.

The Ba-Ir-Ge ternary compounds BaIr2Ge7 and Ba3Ir4Ge16 exhibit superconductivity (SC) at 2.5 and 5.2 K, respectively. Detailed single-crystal structural analysis revealed that these compounds share unique quasi-two-dimensional networks composed of crown-shaped Ge rings that accommodate Ba atoms at the center, referred to as "edge-shared crown-shaped BaGe16 polyhedra". The layered Ba-Ge network yielded a modest anisotropy of 1.3-1.4 in the upper critical field, which is in good agreement with the band structure calculations. The Ba-Ge structural unit is similar to cage structures seen in various clathrates in which the anharmonic vibration of the central atoms, the so-called "rattling" behavior, brings about strong-coupling SC. However, each Ba-Ge unit is relatively small compared to these materials, which likely excludes the possibility of unconventional SC.

Cc.snf5, a gene encoding a putative component of the SWI/SNF chromatin remodeling complex, is essential for sexual development in the agaricomycete Coprinopsis cinerea.

We characterized a Coprinopsis cinerea mutant strain, Spe20, defective in fruiting initiation, which was isolated after restriction enzyme-mediated integration (REMI) mutagenesis of a homokaryotic fruiting strain, 326. A plasmid rescue followed by complementation experiments, RACE, and cDNA analyses revealed that the gene, a mutation of which is responsible for the phenotype, is predicted to encode a protein that exhibits a high similarity to yeast Snf5p, a key component of the chromatin remodeling complex SWI/SNF, and named Cc.snf5. Cc.Snf5 is, however, different from Snf5p in that the former has, in addition to an Snf5 domain comprising N-terminal repeat1 (rp1) and C-terminal repeat2 (rp2) subdomains in a middle region, a GATA Zn-finger domain in a C-terminal region. In strain Spe20, plasmid pPHT1 used for REMI is inserted in the ORF encoding rp2. This raised the possibility that in strain Spe20, the disrupted Cc.Snf5 is functionally active albeit incompletely because it retains rp1. Thus, we disrupted the whole SNF5 domain and its downstream peptide and found that the disruption results in inhibition of not only fruiting initiation but also dikaryon development, a prerequisite for fruiting. We also found that specific disruption of the Zn-finger domain results in inhibition of fruiting initiation. These results indicate that Cc.Snf5 plays an essential role in sexual development of C. cinerea.

Oxidation of ferrocene derivatives in desorption/lonization on porous silicon.

In matrix-assisted laser desorption/ionization (MALDI), the true molecular structures of some analytes are not represented by the observed ions due to a redox reaction. In earlier reports, electron transfer from analyte to chemical matrix has been proposed for the oxidation of ferrocene derivatives in MALDI. To address such a redox phenomenon in laser desorption/ionization processes, two ferrocene derivatives, FcCH2CH2Fc and FcCH2NMe2 [Fc:(CsHs)Fe(CsH4)], were analyzed by a matrix-free method, desorption/ionization on porous silicon (DIOS). The oxidized species, Fc+CH2NMe2 and FcCH2CH2Fc+, were detected in the DIOS mass spectra. The results suggested that electron transfer from the analytes to the sample target occurs during the ionization process.