Search

Computer-assisted surgery is now a common procedure in the field of orthopedics. We present two patients who developed myositis ossificans, a rare complication after navigated knee surgery. Due to careful follow-up and conservative treatment, surgical excision was avoided in both patients with good clinical results. Development of myositis ossificans after navigated knee surgery should be considered in cases of thigh pain and restricted range of motion of the knee., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Snapping pes syndrome is defined as a snapping sensation in the medial knee caused by pes anserinus and rarely occurs. Snapping pes syndrome after unicompartmental knee arthroplasty (UKA) has not been reported yet. We experienced two cases with this syndrome after UKA. Conservative treatment was effective in one case, while surgical excision of the gracilis tendon was necessary to relieve painful snapping in the other case. The main cause of the first case might be posteromedial overhang of the tibial tray that reached up to 5 mm. The probable cause of the second case was posteromedial overhang of the mobile bearing.

Purpose: the efficacy and safety of using a suspensory button for femoral fixation in anatomical anterior cruciate ligament (ACL) reconstruction with bone-patellar tendon-bone (BPTB) graft have not been established. The purpose of the current study was to evaluate bone plug integration onto the femoral socket and migration of the bone plug and the EndoButton (EB) (Smith & Nephew, Andover, MA, USA) after rectangular tunnel ACL reconstruction with BPTB autograft., Methods: thirty-four patients who underwent anatomical rectangular ACL reconstruction with BPTB graft using EB for femoral fixation and in whom three-dimensional (3D) computed tomography (CT) was performed one week and one year after surgery were included in this study. Bone plug integration onto the femoral socket, bone plug migration, soft tissue interposition, EB migration and EB rotation were evaluated on 3D CT. The clinical outcome was also assessed and correlated with the imaging outcomes., Results: the bone plug was integrated onto the femoral socket in all cases. The incidence of bone plug migration, soft tissue interposition, EB migration and EB rotation was 15, 15, 9 and 56%, respectively. No significant association was observed between the imaging outcomes. The postoperative mean Lysholm score was 97.1 ± 5.0 points. The postoperative side-to-side difference, evaluated using a KT-2000 arthrometer, averaged 0.5 ± 1.3 mm. There were no complications associated with EB use. Imaging outcomes did not affect the postoperative KT side-to-side difference., Conclusions: the EB is considered a reliable device for femoral fixation in anatomical rectangular tunnel ACL reconstruction with BPTB autograft., Level of Evidence: Level IV, therapeutic case series.

Background: Bone cutting error can be one of the causes of malalignment in unicompartmental knee arthroplasty (UKA). The amount of cutting error in total knee arthroplasty has been reported. However, none have investigated cutting error in UKA. The purpose of this study was to reveal the amount of cutting error in UKA when open cutting guide was used and clarify whether cutting the tibia horizontally twice using the same cutting guide reduced the cutting errors in UKA., Methods: We measured the alignment of the tibial cutting guides, the first-cut cutting surfaces and the second cut cutting surfaces using the navigation system in 50 UKAs. Cutting error was defined as the angular difference between the cutting guide and cutting surface., Results: The mean absolute first-cut cutting error was 1.9° (1.1° varus) in the coronal plane and 1.1° (0.6° anterior slope) in the sagittal plane, whereas the mean absolute second-cut cutting error was 1.1° (0.6° varus) in the coronal plane and 1.1° (0.4° anterior slope) in the sagittal plane. Cutting the tibia horizontally twice reduced the cutting errors in the coronal plane significantly (P<0.05)., Conclusion: Our study demonstrated that in UKA, cutting the tibia horizontally twice using the same cutting guide reduced cutting error in the coronal plane., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Dihydrouridine (D) is formed by tRNA dihydrouridine synthases (Dus). In mesophiles, multiple Dus enzymes bring about D modifications at several positions in tRNA. The extreme-thermophilic eubacterium Thermus thermophilus, in contrast, has only one dus gene in its genome and only two D modifications (D20 and D20a) in tRNA have been identified. Until now, an in vitro assay system for eubacterial Dus has not been reported. In this study, therefore, we constructed an in vitro assay system using purified Dus. Recombinant T. thermophilus Dus lacking bound tRNA was successfully purified. The in vitro assay revealed that no other factors in living cells were required for D formation. A dus gene disruptant (Δdus) strain of T. thermophilus verified that the two D20 and D20a modifications in tRNA were derived from one Dus protein. The Δdus strain did not show growth retardation at any temperature. The assay system showed that Dus modified tRNA(Phe) transcript at 60°C, demonstrating that other modifications in tRNA are not essential for Dus activity. However, a comparison of the formation of D in native tRNA(Phe) purified from the Δdus strain and tRNA(Phe) transcript revealed that other tRNA modifications are required for D formation at high temperatures., (© The Authors 2015. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.)

Introduction: Recently, remnant-preserving anterior cruciate ligament (ACL) reconstruction has been increasingly performed to achieve revascularization, cell proliferation, and recovery of high-quality proprioception. However, poor arthroscopic visualization makes accurate socket placement during remnant-preserving ACL reconstruction difficult. This study describes a surgical technique used to create an anatomical femoral socket with a three-dimensional (3D) fluoroscopy based navigation system during technically demanding remnant-preserving ACL reconstruction., Surgical Technique: After a reference frame was attached to the femur, an intraoperative image of the distal femur was obtained, transferred to the navigation system and reconstructed into a 3D image. A navigation computer helped the surgeon visualize the entire lateral wall of the femoral notch and lateral intercondylar ridge, even when the remnant of the ruptured ACL impeded arthroscopic visualization of the bone surface. When a guide was placed, the virtual femoral tunnel overlapped the reconstructed 3D image in real time; therefore, only minimal soft tissue debridement was required., Materials and Methods: We treated 47 patients with remnant-preserving ACL reconstruction using this system. The center of the femoral socket aperture was calculated according to the quadrant technique using 3D computed tomography imaging., Results: The femoral socket locations were considered to be an anatomical footprint in accordance with previous cadaveric studies., Conclusions: The 3D fluoroscopy-based navigation can assist surgeons in creating anatomical femoral sockets during remnant-preserving ACL reconstruction.

Purpose: The purpose of this study was to retrospectively evaluate femoral tunnel widening (TW) and migration of the femoral tunnel aperture after anatomic anterior cruciate ligament (ACL) reconstructions with hamstring grafts and bone-patellar tendon-bone (BPTB) grafts., Methods: Of the 105 consecutive patients who underwent ACL reconstruction, the 52 patients who underwent isolated ACL reconstruction and in whom tunnel measurement could be obtained by computed tomography were included in this study. In 26 patients, double-bundle reconstruction (DBR) of the ACL using hamstring tendons was performed. These patients were compared with 26 patients in whom rectangular tunnel ACL reconstruction using BPTB grafts (BPTBR) was performed. Femoral tunnel aperture positioning and TW were investigated postoperatively using 3-dimensional computed tomographic images, which were performed a week and a year after surgery in all patients., Results: In DBR, the average diameter of the anteromedial (AM) femoral tunnel increased by 34.0% in the horizontal direction and 28.2% in the vertical direction, whereas that of the posterolateral (PL) femoral tunnel increased by 58.2% and 73.4%, respectively, at 1 year after surgery compared with 1 week after surgery. The percentage TW value of the PL tunnel was significantly greater than that of the AM tunnel. In BPTBR, the average diameter increased by 22.0% and 17.1%, respectively. The percentage TW value of the PL tunnel in DBR was significantly greater than that of the femoral tunnel in BPTBR. Each tunnel aperture migrated distally ("shallow") in the horizontal direction and high in the vertical direction. AM and PL tunnel apertures in DBR migrated in the vertical direction significantly more than they did in BPTBR. No significant differences between the 2 groups were found in clinical outcomes., Conclusions: The femoral PL tunnel aperture in DBR showed significantly more widening than did the AM tunnel aperture in DBR and the femoral tunnel aperture in BPTBR. Also, greater migration of the femoral tunnel aperture in the vertical direction because of TW was observed in DBR than in BPTBR., Level of Evidence: Level IV, therapeutic case series., (Copyright © 2014 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Background: The target volume for postoperative breast irradiation is the remaining breast tissue, and the axillary region is not an intentional target volume., Patients and Methods: Between 2001 and 2009, eligible women with pT1-2cN0/pN0(sn) breast cancer underwent breast-conserving therapy without axillary dissection. Treatment outcomes between 2 radiotherapy planning groups, high tangent fields with 2-dimensional (2-D) simulation-based planning and 3-dimensional (3-D) computed tomography-based planning with a field-in-field technique, were compared. The correlating factors for axillary failure were also calculated., Results: In total, 678 patients were eligible. As of May 2009, the median follow-up times for the 2-D (n = 346) and 3-D (n = 332) groups were 94 and 52 months, respectively. Patient characteristics were balanced, except for a younger population in the 2-D group and more lymphovascular invasion in the 3-D group. On multivariate analysis, 2-D planning was the only risk factor for axillary failure. In the 2-D and 3-D groups, the 5-year cumulative incidences of axillary failure were 8 (3.1%) and 1 (0.3%) (log-rank p = 0.009), respectively. The respective 5-year overall survival rates were 97.4 and 98.4% (p = 0.4)., Conclusion: High tangent irradiation with 3-D planning improved axillary control compared to that with 2-D planning, suggesting that optimizing axillary dose distribution may impact outcomes.

A conserved guanosine at position 18 (G18) in the D-loop of tRNAs is often modified to 2'-O-methylguanosine (Gm). Formation of Gm18 in eubacterial tRNA is catalyzed by tRNA (Gm18) methyltransferase (TrmH). TrmH enzymes can be divided into two types based on their substrate tRNA specificity. Type I TrmH, including Thermus thermophilus TrmH, can modify all tRNA species, whereas type II TrmH, for example Escherichia coli TrmH, modifies only a subset of tRNA species. Our previous crystal study showed that T. thermophilus TrmH is a class IV S-adenosyl-l-methionine-dependent methyltransferase, which maintains a topological knot structure in the catalytic domain. Because TrmH enzymes have short stretches at the N and C termini instead of a clear RNA binding domain, these stretches are believed to be involved in tRNA recognition. In this study, we demonstrate by site-directed mutagenesis that both N- and C-terminal regions function in tRNA binding. However, in vitro and in vivo chimera protein studies, in which four chimeric proteins of type I and II TrmHs were used, demonstrated that the catalytic domain discriminates substrate tRNAs from nonsubstrate tRNAs. Thus, the N- and C-terminal regions do not function in the substrate tRNA discrimination process. Pre-steady state analysis of complex formation between mutant TrmH proteins and tRNA by stopped-flow fluorescence measurement revealed that the C-terminal region works in the initial binding process, in which nonsubstrate tRNA is not excluded, and that structural movement of the motif 2 region of the catalytic domain in an induced-fit process is involved in substrate tRNA discrimination.

Purpose: We analyzed whether axillary nodal irradiation could control clinically node-negative disease, including those patients with a positive sentinel lymph node biopsy (SLNB), most of whom received regional nodal irradiation. We also evaluated toxicity profiles that resulted from nodal irradiation., Patients and Methods: From 1988 to 2011, 2107 patients with cT1-T2N0M0 breast cancer underwent breast conservation therapy in the absence of axillary dissection: nx group (n = 1548), without any axillary surgery; the sn(-) group (n = 518), with a negative SLNB; and sn(+) group (n = 104), with a positive SLNB., Results: The median follow-up times were 88, 56, and 55 months for the nx, sn(-), and sn(+) groups, respectively. The nx group had more risk factors than did the other 2 groups in terms of age, grade, or T stage. Ninety-eight percent of the sn(-)group received only tangent irradiation, and 100% and 83% of the sn(+) and nx group, respectively, received additional regional nodal irradiation. The 5-year cumulative incidences of axillary failure and regional nodal failure were 34, 3, and 0 (2.7%, 0.7%, and 0%; P = .02, log-rank test) and 57, 4, and 0 (4.4, 1%, and 0; P = .04), respectively. Overall survival rates in 5 years were 96.4%, 98.9%, and 97.6% (P = .03), respectively. Symptomatic but transient radiation pneumonitis developed in 31, 16, and 6 (2.0%, 3.1%, and 5.7%). Mild arm edema was observed in 1, 4, and 0 (0.06%, 0.8%, and 0%) in the nx, sn(-), sn(+) groups, respectively., Conclusions: Treatment without axillary dissection showed excellent outcomes with negligible toxicity for patients with clinically node negative, including those with a positive SLNB. Regional nodal irradiation after a positive SLNB is a reasonable alternative to axillary dissection., (Copyright © 2013 Elsevier Inc. All rights reserved.)

The conserved U54 in tRNA is often modified to 5-methyluridine (m(5)U) and forms a reverse Hoogsteen base pair with A58 that stabilizes the L-shaped tRNA structure. In Gram-positive and some Gram-negative eubacteria, m(5)U54 is produced by folate/FAD-dependent tRNA (m(5)U54) methyltransferase (TrmFO). TrmFO utilizes N(5),N(10)-methylenetetrahydrofolate (CH(2)THF) as a methyl donor. We previously reported an in vitro TrmFO assay system, in which unstable [(14)C]CH(2)THF was supplied from [(14)C]serine and tetrahydrofolate by serine hydroxymethyltransferase. In the current study, we have improved the TrmFO assay system by optimization of enzyme and substrate concentrations and introduction of a filter assay system. Using this assay, we have focused on the tRNA recognition mechanism of TrmFO. 42 tRNA mutant variants were prepared, and experiments with truncated tRNA and microhelix RNAs revealed that the minimum requirement of TrmFO exists in the T-arm structure. The positive determinants for TrmFO were found to be the U54U55C56 sequence and G53-C61 base pair. The gel mobility shift assay and fluorescence quenching showed that the affinity of TrmFO for tRNA in the initial binding process is weak. The inhibition experiments showed that the methylated tRNA is released before the structural change process. Furthermore, we found that A38 prevents incorrect methylation of U32 in the anticodon loop. Moreover, the m(1)A58 modification clearly accelerates the TrmFO reaction, suggesting a synergistic effect of the m(5)U54, m(1)A58, and s(2)U54 modifications on m(5)s(2)U54 formation in Thermus thermophilus cells. The docking model of TrmFO and the T-arm showed that the G53-C61 base pair is not able to directly contact the enzyme.

Cleavage of introns from precursor transfer RNAs (tRNAs) by tRNA splicing endonuclease (EndA) is essential for tRNA maturation in Archaea and Eukarya. In the past, archaeal EndAs were classified into three types (α'2, α4 and α2β2) according to subunit composition. Recently, we have identified a fourth type of archaeal EndA from an uncultivated archaeon Candidatus Micrarchaeum acidiphilum, referred to as ARMAN-2, which is deeply branched within Euryarchaea. The ARMAN-2 EndA forms an ε2 homodimer and has broad substrate specificity like the α2β2 type EndAs found in Crenarchaea and Nanoarchaea. However, the precise architecture of ARMAN-2 EndA was unknown. Here, we report the crystal structure of the ε2 homodimer of ARMAN-2 EndA. The structure reveals that the ε protomer is separated into three novel units (αN, α and βC) fused by two distinct linkers, although the overall structure of ARMAN-2 EndA is similar to those of the other three types of archaeal EndAs. Structural comparison and mutational analyses reveal that an ARMAN-2 type-specific loop (ASL) is involved in the broad substrate specificity and that K161 in the ASL functions as the RNA recognition site. These findings suggest that the broad substrate specificities of ε2 and α2β2 EndAs were separately acquired through different evolutionary processes.

Papillomatous digital dermatitis (PDD) is an infectious foot disease of cattle that is prevalent throughout the world. Although it has been prevalent in Japan since the first case was reported in 1992, full epidemiological and bacteriological examinations have not been conducted. We collected 91 lesions of PDD from 80 dairy cattle on 12 farms in eight regions of Japan to isolate the spirochetes that are frequently detected in lesions. We isolated 40 strains of spirochetes from 24 cattle (30.0%) by a simple two-step culture technique, in which the biopsy samples were incubated at 4 degrees C for 48 to 72 h in an enrichment broth supplemented with antibiotics, which improved the rate of isolation, and then inoculated on selective agar plates. All spirochetes examined were catalase positive and oxidase negative and showed weak beta-hemolytic activity. Enzyme activities were identical to those of Treponema phagedenis ATCC 27087. Sequencing of the 16S rRNA gene showed that all strains isolated had >99% identity to those of the T. phagedenis type strain and of T. phagedenis-like strains isolated from PDD lesions in the United States and Europe. Pulsed-field gel electrophoresis and PCR-based random amplified polymorphism DNA methods revealed considerable diversity among strains isolated not only from different cattle but also from the same individuals. These findings may provide further evidence for the role of these treponemes in the pathogenesis of persistent PDD.

The dynamics of electron adducts of 2'-deoxynucleotides and oligonucelotides (ODNs) were measured spectroscopically by nanosecond pulse radiolysis. The radical anions of the nucleotides were produced within 10 ns by the reaction of hydrated electrons (e(aq)(-)) and were protonated to form the corresponding neutral radicals. At pH 7.0, the radical anion of deoxythymidine (dT(*-)) was protonated to form the neutral radical dT(H)(*) in the time range of microseconds. The rate constant for the protonation was determined as 1.8 x 10(10) M(-1) s(-1). In contrast, the neutral radical of dC(H)(*) was formed immediately after the pulse, suggesting that the protonation occurs within 10 ns. The transient spectra of excess electrons of the double-stranded ODNs 5'-TAATTTAATAT-3' (AT) and 5'-CGGCCCGGCGC-3' (GC) differed from those of pyrimidine radicals (C and T) and their composite. In contrast, the spectra of the electron adducts of the single-stranded ODNs GC and AT exhibited characteristics of C and T, respectively. These results suggest that, in duplex ODNs, the spectral intermediates of G-C and A-T anions complex were formed. On the microsecond time scale, the subsequent changes in absorbance of the ODN AT had a first-order rate constant of 4 x 10(4) s(-1), reflecting the protonation of T.

The deprotonation of guanine cation radical (G+*) in oligonucleotides (ODNs) was measured spectroscopically by nanosecond pulse radiolysis. The G+* in ODN, produced by oxidation with SO4-*, deprotonates to form the neutral G radical (G(-H)*). In experiments using 5-substituted cytosine-modified ODN, substitution of the cytosine C5 hydrogen by a methyl group increased the rate constant of deprotonation, whereas replacement by bromine decreased the rate constant. Kinetic solvent isotope effects on the kinetics of deoxyguanosine (dG) and ODN duplexes were examined in H2O and D2O. The rate constant of formation of G(-H)* in dG was 1.7-fold larger in H2O than D2O, whereas the rate constant in the ODN duplex was 3.8-fold larger in H2O than D2O. These results suggest that the formation of G(-H)* from G+* in the ODN corresponds to the deprotonation of the oxidized hydrogen-bridged (G+*-C) base pair by a water molecule. The characteristic absorption maxima of G+* around 400 nm were shifted to a longer wavelength in the order of G

Background: Breast cancer is likely to have systemic involvement. However, to the authors' knowledge there are few reports to date regarding clinically detected patterns of metastasis, meticulously studied in regard to the natural history of breast cancer, including unusual sites of metastasis., Methods: Patients treated for invasive breast cancer from April 1983 to May 2007 were retrospectively analyzed. Patterns of clinically apparent tumor recurrence, focusing especially on unusual metastases, were studied as well as possible risk factors for unusual metastases and their influence on survival., Results: Overall, 3783 patients were eligible for the current analysis. The median duration of follow-up was 5.0 years (range, 0.6 years-20.4 years). Cumulative 5-year and 10-year survival rates were 89.7% and 81.5%, respectively. "Unusual metastasis" was defined as systemic failure with a frequency of < or =1%; in the current series; it was observed in 85 (2.2%) patients %. Of those, 70 (82%) had preceding metastasis in the usual sites. The median duration until the development of usual and unusual metastasis was 2.3 years and 3.6 years, respectively (P < .0001). Among 764 patients with distant metastasis, the 5-year cumulative overall survival rate in those with or without unusual metastasis was 53.5% and 53.4 years, respectively (P = .33). No risk factors for unusual metastasis were identified., Conclusions: This retrospective study examined the frequency of unusual metastases in a large number of Japanese patients with initially nonmetastatic breast cancer. The prognosis of patients with unusual metastases was found to be similar to that of patients with metastasis only at more usual sites., (2008 American Cancer Society)

We report the first direct observation of charge transport dynamics using time-resolved microwave conductivity and transient absorption spectroscopy techniques on the photolysis of an anthraquinone-bound DNA complex.

Previous studies showed that attentional task performance of schizophrenics was significantly inferior to that of normals. The classical Stroop Color-Word Interference Test is an example of such attentional tasks and performance on the "reverse" Stroop task is reported to discriminate schizophrenics from normals better than the regular Stroop task. These results suggest that schizophrenics are more susceptible to "reverse" Stroop interference in reading incongruent word-color combinations than normals. The group version of the Stroop and reverse-Stroop Color-Word Test, where the response is to choose a matching alternative, was used to test the hypothesis. The results virtually supported the hypothesis. In addition, interference was closely related to the patient's control of impulsiveness. It was suggested that schizophrenics have generation (or translation) deficits between different codes.