Determining optimal length of coracoid graft in the modified Bristow procedure for anterior shoulder instability: A three-dimensional finite element analysis.

BACKGROUND: There is a lack of consensus concerning the coracoid graft length in the modified Bristow procedure. OBJECTIVE: We attempted to determine the optimal graft length using the three-dimensional finite element method. METHODS: In a shoulder model with a 25% anterior glenoid defect, a coracoid graft of varying lengths (5, 10, 15, and 20 mm) was fixed using a half-threaded screw. First, a compressive load of 500 N was applied to the screw head to determine the graft failure load during screw tightening. Next, a tensile load (200 N) was applied to the graft to determine the failure load due to biceps muscle traction. RESULTS: In the screw compression, the failure loads in the 5-, 10-, 15-, and 20-mm models were 252, 370, 377, and 331 N, respectively. In the tensile load applied to the coracoid graft, the failure load exceeded 200 N for both the 5- and 10-mm models. CONCLUSION: The 5-mm graft had a high risk of fracture during intraoperative screw tightening. As for the biceps muscle traction, the 5- and 10-mm-grafts had a lower failure risk than the 15- and 20-mm-grafts. Therefore, we believe that the optimal length of the coracoid graft is 10 mm in the modified Bristow procedure.

[A CASE OF ANAPHYLAXIS INDUCED BY VITAMIN B1 DERIVATIVE IN VITAMIN B INFUSION FORMULATION FOR INTRAVENOUS INJECTION].

A woman in her 20s presented to our clinic with a lower gastrointestinal infection. When we administered intravenous antibacterial and vitamin infusions, she developed anaphylaxis. We performed skin tests to investigate the cause, and an intradermal test was positive for a 1% intravenous vitamin complex. We then performed a component-specific test, which was positive for thiamine disulfide phosphate, a vitamin B1 derivative. We therefore diagnosed anaphylaxis due to thiamine disulfide phosphate. No previous reports have described cross-reactivity between vitamin B1 derivatives. In our case, however, the patient tested positive for fluthiamine hydrochloride, suggesting cross-reactivity. Intravenous vitamin complexes are used in daily clinical practice and should be administered with caution because of the possibility of anaphylaxis, although it occurs infrequently.

Stabilization of radical active species in a MOF nanospace to exploit unique reaction pathways.

We synthesized a metal-organic framework (MOF) using a ligand bearing haloalkoxy chains as a radical precursor. The radicals generated in the MOF upon photoirradiation were stable even at 250 K or under an O2 atmosphere, despite radicals generated from the ligand decomposing at 200 K; thus, the regular arrangement of radicals effectively stabilized them. Moreover, a unique photoproduct was obtained only in the MOF, indicating that the confinement effect in the nanospace enabled a specific reaction that did not occur in the bulk state. We propose a new platform for exploring chemical reactions and materials based on reactive species.

Triplet Carbene with Highly Enhanced Thermal Stability in the Nanospace of a Metal-Organic Framework.

Triplet carbenes (TCs) are of great interest due to their magnetic properties and reactivity, which descend from TCs' unique electronic state. However, the reactivity and stability of TCs are usually a trade-off, and it is difficult to achieve both at the same time. In this work, we were able to enhance the thermal stability of a TC species while maintaining its reactivity by confining them in the nanospace of a metal-organic framework (MOF). We synthesized a new MOF using a TC precursor; subsequently, TCs were generated by photostimulation. The TCs generated in the MOF nanospace were detectable up to 170 K, whereas their non-MOF-confined counterparts (bare ligand) could not be detected above 100 K. In addition, the reactivity of TC generated in MOF with O2 was drastically improved compared to that of bare ligand. Our approach is generally applicable to the stabilization of highly reactive species, whose reactivity needs to be preserved.

Intra-articular biomechanical environment following modified Bristow and Latarjet procedures in shoulders with large glenoid defects: relationship with postoperative complications.

BACKGROUND: Although coracoid transfers including the modified Bristow and Latarjet procedures are widely used to treat anterior shoulder instability, the influence of the choice of procedure on the biomechanical outcomes is not well characterized. We aimed to clarify the intra-articular stress distribution following these 2 procedures using 3-dimensional finite-element analysis and to investigate the role of stress distribution in the pathophysiology of postoperative complications. METHODS: Overall, 6 male patients aged 17-47 years with unilateral anterior shoulder instability were recruited. Computed tomographic digital imaging and communications in medicine (CT-DICOM) data of the contralateral (healthy) shoulder of each patient was obtained and used for developing the 3-dimensional normal glenohumeral joint model. A 25% bony defect was created in the anterior glenoid rim where the coracoid process was transferred in the standing and lying-down positions to create the Bristow and Latarjet models, respectively. The arm position was set as 0° or 90° abduction. The Young moduli of the humerus and scapula were calculated using CT data, and set as 35.0 MPa and 113.8 GPa for the articular cartilage and inserted screw, respectively. A compressive load (50 N) was applied to the greater tuberosity toward the center of the glenoid, and a tensile load (20 N) was applied to the tip of the coracoid in the direction of conjoint tendon. Elastic analysis was used to determine the equivalent stress distribution. RESULTS: A significant reduction in mean equivalent stress was observed within the glenoid cartilage for both models (P = .031); however, a new stress concentration appeared within the grafted coracoid-facing region of the humeral-head cartilage in both models. The proximal half of the coracoid graft exhibited lower equivalent stress than the distal half in 5 of the 6 Latarjet models, whereas the proximal half showed higher equivalent stress than the distal half in all 6 Bristow models. High stress concentration was identified at the midpoint of the inserted screw in Bristow models. DISCUSSION AND CONCLUSIONS: Intra-articular stress distribution may explain the different rates of postoperative complications associated with the modified Bristow and Latarjet procedures. New stress concentration within the humeral-head cartilage might contribute to the development of glenohumeral osteoarthritis following both procedures. Stress shielding in the proximal part of the coracoid graft might contribute to osteolysis following the Latarjet procedure. Surgeons should be aware of the risk of breakage of the inserted screw following the modified Bristow procedure.

Shoulder function after neck dissection: Assessment via a shoulder-specific quality-of-life questionnaire and active shoulder abduction.

OBJECTIVE: Neck dissection results in a high probability of postoperative shoulder functional impairment, even when the spinal accessory nerve is preserved. Therefore, surgeons must inform patients about the expected functional and qualitative recovery of shoulder function after surgery. METHODS: The present study included a prospective cohort of 66 patients (85 neck dissection sides) who underwent neck dissection between December 2015 and July 2017 at a single institution. The active shoulder abduction angles of the affected side and the patient-reported shoulder-specific quality-of-life recovery score of the Western Ontario Rotator Cuff (WORC) questionnaire were examined at 1, 3, 6, 9, and 12 months postoperatively. Additionally, the association between these outcomes and risk factors for shoulder impairment were investigated. RESULTS: The average active shoulder abduction angles were significantly improved at 3 and 6 months postoperatively compared with 1 month postoperatively (96.5 ± 4.3° at 1 month versus 110.1 ± 4.7° at 3 months, p = 0.035, and versus 142.0 ± 4.6° at 6 months, p < 0.0001). The proportion of patients who were unable to abduct their shoulders by 150° or more was significantly lower at 6 months postoperatively (41.5%) compared with 1 month postoperatively (82.4%, p < 0.0001). The WORC score significantly improved from 60.4 ± 2.4% at 1 month postoperatively to 67.9 ± 2.6% at 6 months postoperatively (p = 0.036). Multivariate analysis revealed that postoperative radiotherapy was a significant risk factor for shoulder impairment at 3 and 6 months postoperatively (p = 0.003 and p = 0.027, respectively), and that level V dissection and head and neck irradiation were significant risk factors for a worse shoulder outcome at 6 and 9 months postoperatively (respective p values for level V dissection and head and neck irradiation were p = 0.049 and p = 0.030 at 6 months postoperatively, and p = 0.016 and p = 0.013 at 9 months postoperatively). CONCLUSION: Satisfactory functional and qualitative recovery of shoulder function was achieved at 6 months after neck dissection. Postoperative radiotherapy was a predictor of poor shoulder function in the early postoperative period; both level V dissection and head and neck irradiation were predictors of poor shoulder function at 6 and 9 months after neck dissection.

Exploiting single-electron transfer in Lewis pairs for catalytic bond-forming reactions.

A single-electron transfer (SET) between tris(pentafluorophenyl)borane (B(C6F5)3) and N,N-dialkylanilines is reported, which is operative via the formation of an electron donor-acceptor (EDA) complex involving π-orbital interactions as a key intermediate under dark conditions or visible-light irradiation depending on the structure of the aniline derivatives. This inherent SET in the Lewis pairs initiates the generation of the corresponding α-aminoalkyl radicals and their additions to electron-deficient olefins, revealing the ability of B(C6F5)3 to act as an effective one-electron redox catalyst.

Enantioselective Diels-Alder reaction of 1,2-dihydropyridines with aldehydes using ß-amino alcohol organocatalyst.

The enantioselective Diels-Alder reaction of 1,2-dihydropyridines with aldehydes using an easily prepared optically active ß-amino alcohol catalyst was found to provide optically active isoquinuclidines, an efficient synthetic intermediate of pharmaceutically important compounds such as oseltamivir phosphate, with a satisfactory chemical yield and enantioselectivity (up to 96%, up to 98% ee). In addition, the obtained highly optically pure isoquinuclidine was easily converted to an optically active piperidine having four successive carbon centers.

A heterogeneous palladium catalyst hybridised with a titanium dioxide photocatalyst for direct C-C bond formation between an aromatic ring and acetonitrile.

A palladium catalyst hybridised with a titanium dioxide photocatalyst can promote cyanomethylation of an aromatic ring by using acetonitrile, where the photocatalyst activates acetonitrile to form a cyanomethyl radical before the C-C bond formation using the palladium catalyst.

Solar-UV-signature mutation prefers TCG to CCG: extrapolative consideration from UVA1-induced mutation spectra in mouse skin.

UVA1 exerts its genotoxicity on mammalian skin by producing cyclobutane pyrimidine dimers (CPDs) in DNA and preferentially inducing solar-UV-signature mutations, C → T base substitution mutations at methylated CpG-associated dipyrimidine (Py-mCpG) sites, as demonstrated previously using a 364 nm laser as a UVA1 source and lacZ-transgenic mice that utilize the transgene as a mutational reporter. In the present study, we confirmed that a broadband UVA1 source induced the same mutation profiles in mouse epidermis as the UVA1 laser, generalizing the previous result from a single 364 nm to a wider wavelength range of UVA1 (340-400 nm). Combined with our previous data on the mutation spectra induced in mouse epidermis by UVB, UVA2 and solar UVR, we proved that the solar-UV-signature mutation is commonly observed in the wavelength range from UVB to UVA, and found that UVA1 induces this mutation more preferentially than the other shorter wavelength ranges. This finding indicates that the solar-UV-signature mutation-causing CPDs, which are known to prefer Py-mCpG sites, could be produced with the energy provided by the longer wavelength region of UVR, suggesting a photochemical reaction through the excitation of pyrimidine bases to energy states that can be accomplished by absorption of even low-energy UVR. On the other hand, the lower proportions of solar-UV-signature mutations observed in the mutation spectra for UVB and solar UVR indicate that the direct photochemical reaction through excited singlet state of pyrimidine bases, which can be accomplished only by high-energy UVR, is also involved in the mutation induction at those shorter wavelengths of UVR. We also found that the solar-UV signature prefers 5'-TCG-3' to 5'-CCG-3' as mutational target sites, consistent with the fact that UVA induces CPDs selectively at thymine-containing dipyrimidine sites and that solar UVR induces them preferably at Py-mCpG sites. However, the mutation spectrum in human p53 gene from non-melanoma skin cancers shows the opposite preference for 5'-CCG-3' sites. This apparent discrepancy in the site preference seems to result from the lack of 5'-TCG-3' sites mutable to missense mutations on the nontranscribed strand of human p53 gene, which should be evolutionally acquired under selective pressure from the sun.

The bystander effect is a novel mechanism of UVA-induced melanogenesis.

We successfully identified the bystander effect in B16 murine melanoma cells exposed to UVA irradiation. The effect was identified based on melanogenesis following the medium transfer of the B16 cells, which had been cultured for 24 h after being exposed to UVA irradiation, to nonirradiated cells (bystander cells). Our confirmation study of the functional mechanism of bystander cells confirmed the reduced levels of mitochondrial membrane potential 1-4 h after the medium transfer. In addition, we observed increased levels of intracellular oxidation after 9-12 h, and the generation of melanin radicals, including long-lived radicals, 24 h after medium transfer. Further analysis of bystander factors revealed that the administration of EGTA treatment at the time of medium transfer led to an inhibition of melanogenesis and to neutralization of the mitochondrial membrane potential level, as well as to the restoration of intracellular oxidation levels to those of controls. The results demonstrated that the UVA irradiation bystander effect in B16 cells, as indicated by melanogenesis, was induced by the increase in intracellular oxidation due to the mitochondrial activity of calcium ions, which were among the bystander factors involved in the increase.

Effect of the substitution pattern of alkyl side chain in a benzodithiophene core π-system on intra and inter-molecular charge carrier mobility.

3,7-Didocecyl-2,6-di(5-phenylthiophen-2-yl)benzo[1,2-b:3,4-b']dithiophene (1) and its 4,8-didodecyl isomer 2 were prepared as the representative soluble X- and cross-shaped π-conjugated oligomer systems to provide insight into the effect of the substitution pattern of the alkyl side chain on electronic properties. The absorption and emission spectra as well as CV data showed the relatively longer effective conjugation of cross-shaped 2. The intrinsic charge-carrier mobilities were then estimated by flash-photolysis time-resolved microwave conductivity (FP-TRMC) method and compared with their top contact FET properties. It was found that, although the TRMC method showed the higher mobility of 2 than 1, the FET performance of 1 after appropriate conditioning and thermal annealing was superior to that of 2. The effective conjugation of cross-shaped 2 is well reflected in the intramolecular mobility of positive holes estimated by FP-TRMC, showing striking contrast to the rather higher mobility of X-shaped 1 observed by FET as well as TOF measurements as the long-range translational motion of the carriers. This strongly suggests that the intermolecular packing of these compounds plays a significant role in the range of hole mobility of <∼10(-2) cm(2) V(-1) s(-1).

Negative and positive ion trapping by isotopic molecules in cryocrystals in case of solid parahydrogen containing electrons and H(6) (+) radical cations.

We performed electron spin resonance studies of trapped electrons and H(6) (+) radical cations produced by radiolysis of solid parahydrogen (p-H(2)), p-H(2)-ortho-D(2) (o-D(2)), and p-H(2)-HD mixtures. Yields of trapped electrons, H(6) (+) radical cations, and its isotopic analogs H(6-n)D(n) (+) (4>or=n>or=1) increased with increasing o-D(2) and HD concentrations in solid p-H(2). Electrons were found trapped near an o-D(2) or an HD in solid p-H(2) due to the long-range charge-induced dipole and quadrupole interactions between electrons and isotopic hydrogen molecules. H(6) (+) radical cations diffuse in solid p-H(2) by repetition of H(6) (+)+H(2)-->H(2)+H(6) (+) and are trapped by ortho-D(2) or HD to form H(6-n)D(n) (+) (4>or=n>or=1) as isotope condensation reactions. Decay behaviors of these cations by the repetition, isotope condensation, and geminate recombination between electrons and H(6-n)D(n) (+) (4>or=n>or=0) were reproduced by determining the corresponding reaction rate constants k(1), k(2), and k(3). Values of 0.045 and 0.0015 L mol(-1) min(-1) were obtained for k(1) (H(6) (+)+D(2)-->H(2)+H(4)D(2) (+)) and k(2) (H(4)D(2) (+)+D(2)-->H(2)+H(2)D(4) (+)), respectively, and the value was quasinull for k(3) (H(2)D(4) (+)+D(2)-->H(2)+D(6) (+)). These rate constants suggest that hole mobility drastically decreased in the repetition reaction when H(6) (+) radical cations acting as hole carriers formed H(4)D(2) (+) or H(2)D(4) (+). HD and D(2) molecules, therefore, act as electron and hole acceptors in irradiated solid p-H(2)-o-D(2) and p-H(2)-HD mixtures.

Electron spin resonance spectroscopy of molecules in large precessional motion: a case of H6(+) and H4D2(+) in solid parahydrogen.

We have measured electron spin resonance (ESR) spectra of H6+ and H4D2(+) ions produced in gamma-ray irradiated solid parahydrogen. Anisotropic hyperfine-coupling constants for H6(+) and H4D2(+) determined by the analysis of ESR lines at 4.2K were -0.06 and -0.12 mT, respectively, which were opposite in sign to and much smaller than theoretical results of 1.17-1.25 mT. Although no change was observed in H6(+), the constant for H4D2(+) increased to be 1.17 mT at 1.7 K, which is very close to the theoretical value. We concluded that H6+ both at 4.2 and 1.7 K and H4D2(+) at 4.2K should be in a large precessional motion with the angle of 57-59 degrees, but the precession of H4D2(+) is stopped at 1.7 K.

Electron spin resonance study on H6+, H5D+, H4D2+, and H2D4+ in solid parahydrogen.

We carried out an electron spin resonance (ESR) study on hydrogen ion radicals produced by radiolysis of solid para-H(2). In addition to quartet ESR lines proposed to be H(2) (+)-core H(6) (+) (D(2d)) ions in solid para-H(2) [T. Kumada et al., Phys. Chem. Chem. Phys. 7, 776 (2005)], we newly observed totally more than 50 resolved lines in gamma-ray irradiated solid para-H(2)-ortho-D(2) (1 mol %) and para-H(2)-HD (1 mol %) mixtures. We assigned these lines to be isotope substituents of H(2) (+)-core H(6) (+) ions such as H(5)D(+), H(4)D(2) (+), and H(2)D(4) (+) throughout the comparison of their ESR parameters with theoretical results. These results provide a conclusive evidence that H(2) (+)-core H(6) (+) ions are generated in irradiated solid hydrogens. Analysis of the EPR spectrum and ab initio calculations predicts D(2d) symmetry of the H(6) (+) ions, whereas a lowering symmetry (D(2d)-->C(2v)) induced by asymmetric nuclear wave function is observed in H(5)D(+) and H(4)D(2) (+). We also observed isotope-substitution reactions such as H(6) (+)+D(2)-->H(4)D(2) (+)+H(2) and H(6) (+)+HD-->H(5)D(+)+H(2), which are analogous to the well-known isotope-condensation reactions of H(3) (+) in dark nebula, H(3) (+)+HD-->HD(2) (+)+H(2) and HD(2) (+)+HD-->D(3) (+)+H(2).

Osteolipoma arising adjacent to the sternoclavicular joint. A case report.

A 45-year-old woman presented with one-year history of a mass on her chest. Computed tomography and magnetic resonance imaging demonstrated a tumour near the sternoclavicular joint. The tumour was diagnosed as osteolipoma histologically after resection. Osteolipoma is a rare tumour and this may be the first report of osteolipoma arising adjacent to the sternoclavicular joint.

Heterotopic ossification of the distal portion of biceps femoris: case report and review of the literature.

Heterotopic ossification is the formation of mature lamellar bone in soft tissue. We report a very unusual case of heterotopic ossification arising in the distal portion of the biceps femoris muscle. A 29-year-old woman presented with knee pain after playing golf. She had had no apparent history of trauma. Radiography of the knee showed a calcified mass adjacent to the lateral side of her knee joint. The radiological diagnosis was calcification of the lateral collateral ligament. The pain soon disappeared without treatment. At the age of 45 years, she complained of a growing mass in her left knee that was occasionally painful. Computed tomography and magnetic resonance imaging demonstrated a well matured ossified mass in the lateral side of her left knee. Radiologically and macroscopically, it was found to be in continuity with the distal part of biceps femoris. The mass was excised en bloc. Microscopically, the lesion was mainly composed of well-matured lamellar bone with bone marrow and islands of cartilage showing enchondral ossification. No apparent zoning was found. Cellular atypia was not observed. Extraskeletal osteosarcoma was ruled out. The mass was diagnosed as a heterotopic ossification arising from the distal part of biceps femoris.

Long-lived mutagenic radicals induced in mammalian cells by ionizing radiation are mainly localized to proteins.

We have provided evidence that long-lived radicals, produced by ionizing radiation, are highly mutagenic and transforming in mammalian cells. Long-lived radicals are scavenged effectively by vitamin C or by epigallocatechin-3-O-gallate (EGCG). Long-lived radicals are not involved in lethality or in the induction of chromosome aberrations. We now report the results of experiments that define the relative amounts of long-lived radicals in DNA and proteins and identify the major protein radicals as sulfinyl radicals (R-CH2-S-O*). To make these assignments, yields of long-lived radicals in gamma-irradiated salmon sperm DNA and albumin were compared by ESR. ESR spectra of long-lived radicals produced in irradiated Syrian hamster embryo (SHE) cells were analyzed precisely and compared with ESR parameters obtained by density functional theory calculations. Long-lived radicals yields of 99.8% were produced in proteins. We also identified a new type of long-lived radical as H-added phenylalanine radicals. While our evidence does not rule out the possibility of important biological consequences of the low-level long-lived radicals created by radiation, it implicates radicals in proteins as playing a key role in genetic effects of ionizing radiation. We suggest that these novel radicals, wherever they reside, need to be considered in explanations of biological sequela of radiation.

Experimental fascial autografting for the supraspinatus tendon defect: remodeling process of the grafted fascia and the insertion into bone.

To elucidate the postoperative histologic changes of fascial autografting, tendinous defects (1.5 x 1.5 cm) were created close to the supraspinatus insertion and were covered by fascial autografts in 21 rabbits. Shoulders harvested on the fourth day and 1, 2, 3, 4, 6, and 8 weeks after surgery were examined histologically and immunohistochemically. At the fascia-bone junction, chondrocytes started to appear at 2 weeks after surgery and increased rapidly thereafter. Although a tidemark was not seen, remodeling of direct insertion with fibrocartilage was almost complete by 8 weeks. The distribution of collagen types II and III represented a pattern similar to that of a normal supraspinatus tendon insertion. In the grafted fascia, the cellular density showed a marked increase over time (r2 = 0.74, P <.0001). Our study revealed that both the tendinous tissue and its insertion were reformed after this procedure. Fascial autografting might be useful for repairing a supraspinatus tendon defect.