Theoretical study of correlations between the coordination structures and catalytic activities in polymer-stabilized au nanocluster catalysts.

Au nanoclusters (Au NCs) stabilized by poly(N-vinyl-2-pyrrolidone) and poly(allylamine), abbreviated to Au:PVP and Au:PAA, catalyze the aerobic oxidation of p-hydroxybenzyl alcohols, but the catalytic activity of Au:PVP is much higher than that of Au:PAA. To elucidate the correlations between the catalytic activities and coordination structures of the stabilizing polymer, the substrate accessibility on Au NCs was estimated by density functional theory (DFT) and molecular dynamics (MD) calculations. For MD simulations, we applied a systematic method to optimize the temperature parameters in temperature replica exchange molecular dynamics (T-REMD), and the coordination structures were comprehensively classified by multivariate analysis. The results show that the number of open active sites on the Au NCs is a good index for predicting the catalytic activities. © 2018 Wiley Periodicals, Inc.

Extent of Spin Contamination Errors in DFT/Plane-wave Calculation of Surfaces: A Case of Au Atom Aggregation on a MgO Surface.

The aggregation of Au atoms onto a Au dimer (Au2) on a MgO (001) surface was calculated by restricted (spin-un-polarized) and unrestricted (spin-polarized) density functional theory calculations with a plane-wave basis and the approximate spin projection (AP) method. The unrestricted calculations included spin contamination errors of 0.0⁻0.1 eV, and the errors were removed using the AP method. The potential energy curves for the aggregation reaction estimated by the restricted and unrestricted calculations were different owing to the estimation of the open-shell structure by the unrestricted calculations. These results show the importance of the open-shell structure and correction of the spin contamination error for the calculation of small-cluster-aggregations and molecule dimerization on surfaces.

A Diagnostic Scoring System for Sacroiliac Joint Pain Originating from the Posterior Ligament.

Objective: Sacroiliac joint (SIJ) pain originating from the posterior ligament manifests in not only the buttocks but also the groin and lower extremities and thus may be difficult to discern from pain secondary to other lumbar disorders. We aimed to develop a simple clinical diagnostic tool to help physicians distinguish between patients with SIJ pain originating from the posterior ligament and those with lumbar disc herniation (LDH) or lumbar spinal canal stenosis (LSS). Design: Prospective case-control study. Patients and Methods: We evaluated 62 patients with SIJ pain originating from the posterior ligament and 59 patients with LDH and LSS. Pain areas, pain increasing positions, provocation test, and tenderness points were investigated. A scoring system based on multivariate logistic regression equations using the investigated items was developed. Results: Two pain areas (the posterosuperior iliac spine (PSIS) detected by the one-finger test and groin), pain while sitting on a chair, provocation test, and two tenderness points (PSIS and the sacrotuberous ligament) had high odds ratios (range, 25.87­1.40) and were used as factors in the scoring system. An integer score derived from the regression coefficient and clinical experience was assigned to each identified risk factor. The sum of the risk score for each patient ranged from 0­9. This scoring system had a sensitivity of 90.3% and a specificity of 86.4% for a positivity cutoff point of 4. Conclusion: The scoring system can help distinguish between patients with SIJ pain originating from the posterior ligament and those with LDH and LSS.

Advances in Gold Catalysis and Understanding the Catalytic Mechanism.

When gold is deposited as nanoparticles (NPs) with mean diameters of 2-5 nm or clusters with mean diameters below 2 nm onto a variety of supports such as metal oxides, carbons, polymers, etc., the supported Au NPs exhibit unique catalytic properties, while bulk Au is almost inert as a catalyst. A lot of research works indicate that the key factors of the catalysis by supported Au NPs are the selection of the supports, the control of the Au NP size, the shape of the Au NPs, and the strong junction between Au NPs and the supports, because the perimeter zone around Au NPs acts as the active site for many reactions. In order to elucidate the origin of catalysis by supported Au NPs, the interplay between physicochemical analysis, computational studies, and rational experiments for catalysis by supported Au NPs is becoming more and more important. This article summarizes our experiences and progress in such interplay.

The diagnostic value of single-photon emission computed tomography/computed tomography for severe sacroiliac joint dysfunction.

PURPOSE: We aimed to evaluate the value of single-photon emission computed tomography (SPECT)/computed tomography (CT) for the diagnosis of sacroiliac joint (SIJ) dysfunction. METHODS: SPECT/CT was performed in 32 patients with severe SIJ dysfunction, who did not respond to 1-year conservative treatment and had a score of >4 points on a 10-cm visual analog scale. We investigated the relationship between the presence of severe SIJ dysfunction and tracer accumulation, as confirmed by SPECT/CT. In cases of bilateral SIJ dysfunction, we also compared the intensity of tracer accumulation on each side. Moreover, we examined the relationship between the intensity of tracer accumulation and the different treatments the patients subsequently received. RESULTS: All 32 patients with severe SIJ dysfunction had tracer accumulation with a standardized uptake value (SUV) of >2.2 (mean SUV 4.7). In the 19 patients with lateralized symptom intensity, mean SUVs of the dominant side were significantly higher than those of the nondominant side. In 10 patients with no lateralization, the difference in the SUVs between sides was <0.6. Patients exhibiting higher levels of tracer accumulation required more advanced treatment. CONCLUSION: Patients with higher levels of tracer accumulation had greater symptom severity and also required more advanced treatment. Thus, we believe that SPECT/CT may be a suitable supplementary diagnostic modality for SIJ dysfunction as well as a useful technique for predicting the prognosis of this condition.

Refraction, beam splitting and dispersion of GHz surface acoustic waves by a phononic crystal.

We exploit a time-resolved ultrafast optical technique to study the propagation of point-excited surface acoustic waves on a microscopic two-dimensional phononic crystal in the form of a square lattice of holes in a silicon substrate. Constant-frequency images and the dispersion relation are extracted, and the latter measured in detail in the region around the phononic band gap. Mode conversion and refraction at the interface between the phononic crystal and surrounding non-structured silicon substrate is studied at constant frequencies. Symmetric phonon beam splitting, for example, is shown to lead to a striking Maltese-cross pattern when phonons exit a square region of phononic crystal excited near its center.

Ethnic Differences in Western and Asian Sacroiliac Joint Anatomy for Surgical Planning of Minimally Invasive Sacroiliac Joint Fusion.

Pain originating in the sacroiliac joint (SIJ) is a contributor to chronic lower back pain. Studies on minimally invasive SIJ fusion for chronic pain have been performed in Western populations. Given the shorter stature of Asian populations compared with Western populations, questions can be raised regarding the suitability of the procedure in Asian patients. This study investigated the differences in 12 measurements of sacral and SIJ anatomy between two ethnic populations by analyzing computed tomography scans of 86 patients with SIJ pain. Univariate linear regression was performed to evaluate the correlations of body height with sacral and SIJ measurements. Multivariate regression analysis was used to evaluate systematic differences across populations. Most sacral and SIJ measurements were moderately correlated with body height. The anterior-posterior thickness of the sacral ala at the level of the S1 body was significantly smaller in the Asian patients compared with the Western patients. Most measurements were above standard surgical thresholds for safe transiliac placement of devices (1026 of 1032, 99.4%); all the measurements below these surgical thresholds were found in the anterior-posterior distance of the sacral ala at the S2 foramen level. Overall, safe placement of implants was allowed in 84 of 86 (97.7%) patients. Sacral and SIJ anatomy relevant to transiliac device placement is variable and correlates moderately with body height, and the cross-ethnic variations are not significant. Our findings raise a few concerns regarding sacral and SIJ anatomy variation that would prevent safe placement of fusion implants in Asian patients. However, considering the observed S2-related anatomic variation that could affect placement strategy, sacral and SIJ anatomy should still be preoperatively evaluated.

Cervical pedicle screw insertion using a gutter entry point at the transitional area between the lateral mass and lamina.

PURPOSE: The purpose of this study was to describe a free-hand pedicle screw insertion technique and to evaluate the accuracy of pedicle screw placement and validity of pedicle screw fixation in patients with subaxial cervical spine injuries. METHODS: We retrospectively reviewed 32 consecutive patients with subaxial cervical spine injuries who underwent posterior cervical fixation using our cervical pedicle screw (CPS) insertion technique. We also assessed the clinical and radiological outcomes and the accuracy of pedicle screw placement. RESULTS: The mean preoperative kyphosis was 4.0°, which was corrected to -5.2° after the operation, and the mean kyphosis angle was -4.4° at the final follow-up. The mean preoperative disc height ratio was 81.9%, and it improved to 105.4% after the operation, which was maintained until the final follow-up measurement of 103.4%. Bony union was achieved, and there were no instrumentation failures in any patient. Overall, 127 pedicle screws were inserted, of which 112 (88.1%) were classified as grade 1 (exact intrapedicular screw positioning), 10 (7.8%) as grade 2 (perforation <50% of the screw diameter), and 5 (3.9%) as grade 3 (perforation more than 50% of the screw diameter). CONCLUSION: In our technique, a gutter is created using a high-speed burr at the transitional area between the lateral mass and lamina similar to the procedure in double-door laminoplasty to identify an entry point for CPS insertion. It is easy for general spine surgeons to identify a CPS insertion entry point using our technique.

The use of antibiotic-impregnated fibrin sealant for the prevention of surgical site infection associated with spinal instrumentation.

PURPOSE: The purpose of this study was to determine if the use of antibiotic-impregnated fibrin sealant (AFS) was effective in preventing surgical site infections (SSI) associated with spinal instrumentation. METHODS: In a preliminary study, five pieces of vancomycin-impregnated fibrin sealant, five nuts that were not treated with the sealant, and five nuts that were treated with the sealant were subjected to agar diffusion testing. In a clinical study, the rates of deep SSI were compared between 188 patients who underwent procedures involving spinal instrumentation without AFS (group 1) and 196 patients who underwent procedures involving spinal instrumentation with AFS (group 2). RESULTS: All five pieces of vancomycin-impregnated fibrin sealant and the five nuts treated with the sealant exhibited antimicrobial efficacy, while the five untreated nuts did not exhibit antimicrobial efficacy in the agar diffusion test. In the clinical study, 11 (5.8 %) of the 188 patients in group 1 acquired a deep SSI, while none (0 %) of the 196 patients in group 2 acquired a deep SSI. CONCLUSION: The present study demonstrated that the application of AFS to spinal instrumentation yielded good clinical outcomes in terms of the prevention of postoperative spinal infections. It is hoped that limiting AFS use to patients requiring spinal instrumentation and those with risk factors for SSI will reduce the overall costs while preventing SSIs.

Combined posterior and delayed staged mini-open anterior short-segment fusion for thoracolumbar burst fractures.

STUDY DESIGN: A prospective study. OBJECTIVES: To assess the outcome of patients with a single thoracolumbar burst fracture treated with circumferential short-segment fusion consisting of posterior reduction, short-segment fusion, and delayed staged mini-open anterior short-segment fusion. SUMMARY OF BACKGROUND DATA: The surgical treatment of thoracolumbar burst fractures remains controversial. In attempting to combine the advantages of posterior procedures, including initial correction of kyphosis and early decompression, and those of anterior procedures, including direct decompression and restoration of anterior column support, a combined posterior and delayed staged anterior procedure seems to be a reasonable choice. However, conventional combined procedures are invasive. METHODS: We prospectively selected 28 consecutive patients with single thoracolumbar burst fracture for circumferential short-segment fusion consisting of posterior reduction, short-segment fusion, and delayed staged mini-open anterior short-segment fusion. The pedicle screw systems were removed after confirmation of posterior bony fusion to preserve as many motion segments as possible in those patients who could be treated with circumferential monosegmental fusion. Radiographic and clinical assessment of 28 patients who received this treatment was carried out. RESULTS: The mean loss of correction of kyphosis between the time of the combined procedure and final follow-up was 3.7 degrees (range, 0 to 10.2 degrees). Bony fusion was eventually achieved in all patients. There were 15 cases with monosegmental and 13 cases with bisegmental circumferential fusion. All 10 patients with initial neurological deficit improved by at least 1 Frankel grade: 3 improved by 1 grade, 5 improved by 2 grades, and 2 improved by 3 grades. In total, 27 patients, who were P1 or P2 on the Denis pain scale, were considered to have obtained clinically satisfactory results. CONCLUSIONS: This combined procedure is less invasive than the conventional combined one, and finally achieves shorter stabilization, resulting in preservation of motion segments. It thus seems to be a reasonable treatment option for thoracolumbar burst fractures.

Three-Year Clinical Outcomes after Minimally Invasive Sacroiliac Joint Arthrodesis Using Triangular Implants in Japan: A Pilot Study of Five Cases.

INTRODUCTION: Sacroiliac joint (SIJ) arthrodesis using a minimally invasive technique, particularly the triangular implant system, is performed in patients with SIJ dysfunction in the United States and Europe. We report three-year clinical outcomes of the first minimally invasive SIJ arthrodesis procedures using the implants performed in Japan. METHODS: Five patients (one man and four women; age: 56.4±16.9 years) with SIJ pain who underwent SIJ arthrodesis using a triangular implant system in 2017 were included. In addition to operation time and blood loss, pain intensity (visual analog scale [VAS]) and functional impairment (Oswestry disability index [ODI]) were assessed preoperatively and at a 36-month follow-up. Implant loosening and osseous bridging across the joint were evaluated using computed tomography images, and patients' satisfaction with the surgery was also assessed at 12 and 36 months. RESULTS: The surgical time was 67.7±13.1 minutes, and blood loss was 7.4±6.9 mL. The mean VAS value improved significantly from 88.0±8.4 mm to 33.6±31.9 mm at 3 months and was maintained at 46.4±30.9 mm at 36 months (P<0.05). The mean ODI improved significantly from 76.4%±3.8% to 46.2%±21.9% at 6 months postoperatively (P<0.05) but had no significant improvements thereafter: 46.94±23.7% (12 months) and 66.4±8.6% (36 months). Three of five patients presented with at least one implant loosening on the sacrum side. No patient had osseous bridging across the joint. A total of 80% (4/5) of patients reported satisfaction with the surgery at 12 months and 60% (3/5) at 36 months. CONCLUSIONS: The mean VAS value and ODI significantly improved until 6 months after the surgery. However, the mean ODI was reaggravated at 36 months after the surgery. Osseous bridging across the joint was not observed in all patients. We should carefully keep an eye on further long-term results to evaluate the implant.

Nanostructured LiMnO2 with Li3PO4 Integrated at the Atomic Scale for High-Energy Electrode Materials with Reversible Anionic Redox.

Nanostructured LiMnO2 integrated with Li3PO4 was successfully synthesized by the mechanical milling route and examined as a new series of positive electrode materials for rechargeable lithium batteries. Although uniform mixing at the atomic scale between LiMnO2 and Li3PO4 was not anticipated because of the noncompatibility of crystal structures for both phases, our study reveals that phosphorus ions with excess lithium ions dissolve into nanosize crystalline LiMnO2 as first evidenced by elemental mapping using STEM-EELS combined with total X-ray scattering, solid-state NMR spectroscopy, and a theoretical ab initio study. The integrated phase features a low-crystallinity metastable phase with a unique nanostructure; the phosphorus ion located at the tetrahedral site shares faces with adjacent lithium ions at slightly distorted octahedral sites. This phase delivers a large reversible capacity of ∼320 mA h g-1 as a high-energy positive electrode material in Li cells. The large reversible capacity originated from the contribution from the anionic redox of oxygen coupled with the cationic redox of Mn ions, as evidenced by operando soft XAS spectroscopy, and the superior reversibility of the anionic redox and the suppression of oxygen loss were also found by online electrochemical mass spectroscopy. The improved reversibility of the anionic redox originates from the presence of phosphorus ions associated with the suppression of oxygen dimerization, as supported by a theoretical study. From these results, the mechanistic foundations of nanostructured high-capacity positive electrode materials were established, and further chemical and physical optimization may lead to the development of next-generation electrochemical devices.

L2-L3 flexion-distraction injury treated by posterior fusion using ultra-high molecular weight polyethylene tape in a 7-year-old boy.

A 7-year-old boy was sitting in the back seat of a car wearing a lap seatbelt when the car was involved in a head-on collision with another vehicle. Radiographs revealed mild scoliosis, anterior column compression of L3 and enlargement of both the intervertebral foramen and interspinous distance between L2 and L3. Computed tomography revealed bilateral L2-L3 facet joint disruption with fracture of the L2 spinous process. Magnetic resonance imaging revealed rupture of the posterior ligamentous complex. An open reduction and posterior fusion with autologous bone graft using 5-mm-wide ultra-high molecular weight polyethylene tape sublaminar wiring was performed. Three months after surgery, bony fusion of L2-L3 was observed. At 6 months after surgery, the patient was asymptomatic and had resumed previous activities.

Effects of branched-chain amino acids and vitamin D supplementation on physical function, muscle mass and strength, and nutritional status in sarcopenic older adults undergoing hospital-based rehabilitation: A multicenter randomized controlled trial.

AIM: To investigate the effects of branched-chain amino acids and vitamin D supplementation on physical function, muscle strength, muscle mass, and nutritional status in sarcopenic older adults undergoing hospital-based rehabilitation. METHODS: We carried out an 8-week, multicenter, randomized, controlled, blinded outcome, two-cohort parallel group intervention trial of sarcopenic older adults undergoing in-hospital rehabilitation. The eligibility criteria included older adults (aged ≥65 years) with low muscle strength (handgrip strength) and low muscle mass (calf circumference) according to the cut-off values for older Asians. The intervention group received branched-chain amino acids and vitamin D supplementation, whereas the control group did not. Both groups underwent low-intensity resistance training in addition to the post-acute rehabilitation program. The primary outcome of physical function (Functional Independence Measure-motor scores), and the secondary outcomes of muscle strength (handgrip strength), muscle mass (calf circumference) and nutritional status (body mass index) were measured at baseline and at the end of the intervention. RESULTS: Finally, a total of 68 patients were analyzed (intention-to-treat analysis): 35 in the intervention group and 33 in the control group. Functional Independence Measure-motor scores increased significantly in both groups over time (P < 0.05). However, no treatment-by-time effects were observed (median estimated difference 2.4, 95% confidence interval -1.2 to 7.1). Handgrip strength, calf circumference and body mass index increased significantly in both groups over time (P < 0.05), with significantly greater improvements in the intervention group (P = 0.041, 0.033 and 0.035, respectively). CONCLUSIONS: We showed that an 8-week intervention of branched-chain amino acids and vitamin D supplementation with low-intensity resistance training improves muscle-related outcomes in sarcopenic older adults undergoing hospital-based rehabilitation (UMIN000006238). Geriatr Gerontol Int 2019; 19: 12-17.

Hospital dental hygienist intervention improves activities of daily living, home discharge and mortality in post-acute rehabilitation.

AIM: To examine the effects of oral management provided by dental hygienists (DH) on patient outcomes in post-acute rehabilitation. METHODS: We carried out a retrospective cohort study with 1056 patients newly admitted to a post-rehabilitation hospital in Japan. DH care was defined as two or more consecutive instances of oral management provided by a ward DH during hospitalization. The primary outcome was the motor domain of Functional Independence Measure score at discharge. Other outcomes included the rate of home discharge; length of stay, all-cause in-hospital mortality, and oral, swallowing and nutritional status at discharge. Propensity score matching was carried out to control and adjust for patients' backgrounds to compare outcomes between patients who did or did not receive DH care. RESULTS: Of 1056 patients enrolled (mean age 71 years; 52.0% women; 73.1% with oral problems), 415 (39.3%) received DH care. Multivariate analyses using pair-matched patients showed that DH care was significantly associated with higher motor domain of Functional Independence Measure score at discharge (ß = 0.281, P = 0.041), shorter length of stay (ß = 0.446, P = 0.044), higher rate of home discharge (odds ratio 1.202, 95% confidence interval 1.026-1.491, P = 0.037) and lower mortality (hazard ratio 0.818, 95% confidence interval 0.738-0.952, P = 0.037) after adjusting for potential covariates. CONCLUSIONS: DH oral management improves patient outcomes, including activities of daily living, home discharge and in-hospital mortality in post-acute rehabilitation. Early detection of oral problems, early oral treatment by dental professionals, and cooperation between medical and dental professionals should be implemented. Geriatr Gerontol Int 2019; 19: 189-196.

Sarcopenia is associated with worse recovery of physical function and dysphagia and a lower rate of home discharge in Japanese hospitalized adults undergoing convalescent rehabilitation.

OBJECTIVE: The aim of this study was to evaluate the effect of sarcopenia on functional outcomes, including activities of daily living (ADLs); dysphagia status; and the rate of home discharge, among hospitalized adults receiving convalescent rehabilitation. METHODS: A retrospective cohort study was conducted with 898 patients newly admitted to in-hospital convalescent rehabilitation wards at a single rehabilitation hospital in Japan. Baseline sarcopenia was diagnosed using muscle mass index and handgrip strength according to the criteria of the European Working Group on Sarcopenia in Older People, with the cutoff values of the Asian Working Group for Sarcopenia. The primary outcome was ADLs, assessed by Functional Independence Measure motor (FIM-motor) score at hospital discharge. The secondary outcomes included dysphagia, assessed by the Food Intake Level Scale (FILS), at discharge, and the rate of home discharge. Three multivariate analyses revealed an association between sarcopenia and the clinical outcomes. Each analysis adjusted for the following confounders: age, sex, time from onset, premorbid ADLs, comorbidities, cognitive level, nutritional status, major drugs, and admission diagnoses. RESULTS: After enrollment, 795 patients (mean age 74.9 ± 13.2 y; 59% women) were included in the final analysis. Admission diagnoses included stroke (n = 276; 34.7%), musculoskeletal disorders (n = 382; 48.1%), and hospital-associated deconditioning (n = 137; 17.2%). Of the 795 patients examined, 402 (50.6%) had sarcopenia. The multiple linear regression analysis showed that sarcopenia was independently associated with FIM motor score at discharge in patients with all disease types (ß = -0.189 [stroke], -0.240 [musculoskeletal disorders], -0.230 [hospital-associated deconditioning]; all P < 0.05), with FILS score at discharge only in patients with musculoskeletal disorders (ß = -0.271, P < 0.001), but not in patients with stroke (ß = -0.061, P = 0.375) or those with hospital-associated deconditioning (ß = -0.131, P = 0.070). The multiple logistic regression analysis showed that sarcopenia was associated with rate of home discharge in all disease types (odds ratio [OR], 0.201; 95% confidence interval [CI], 0.067-0.597 for stroke; OR, 0.242; 95% CI, 0.076-0.772 for musculoskeletal disorders; OR, 0.121; 95% CI, 0.110-0.347 for hospital-associated deconditioning; all P < 0.05). CONCLUSIONS: Sarcopenia is associated with worse recovery of ADLs and dysphagia and a lower rate of home discharge in hospitalized adults undergoing convalescent rehabilitation. Early detection of sarcopenia and treatment by rehabilitation nutrition should be implemented in this population.

Systemic Inflammation in the Recovery Stage of Stroke: Its Association with Sarcopenia and Poor Functional Rehabilitation Outcomes.

OBJECTIVE: The aim of our study was to investigate how systemic inflammation relates to sarcopenia and its impact on functional outcomes in the recovery stages of stroke. METHODS: A retrospective cohort study was performed in consecutive patients admitted to convalescent rehabilitation wards following stroke. Patients with acute or chronic high-grade inflammatory diseases were excluded. Systemic inflammation was evaluated using the modified Glasgow Prognostic Score (mGPS). Sarcopenia was defined as a loss of skeletal muscle mass and decreased muscle strength, with the cut-off values set by the Asian Working Group for Sarcopenia. The primary outcome was the motor domain of the Functional Independence Measure (FIM-motor). Univariate and multivariate analyses were used to determine whether mGPS was associated with sarcopenia and FIM-motor at discharge. RESULTS: The study included 204 patients (mean age 74.1 years, 109 men). mGPS scores of 0, 1, and 2 were assigned to 149 (73.0%), 40 (19.6%), and 13 (6.4%) patients, respectively. Sarcopenia was diagnosed in 81 (39.7%) patients and was independently associated with stroke history (odds ratio [OR] 1.890, P=0.027), premorbid modified Rankin scale (OR 1.520, P=0.040), body mass index (OR 0.858, P=0.022), and mGPS score (OR 1.380, P=0.021). Furthermore, the mGPS score was independently associated with sarcopenia (OR 1.380, P=0.021) and FIM-motor at discharge (ß=-0.131, P=0.031). CONCLUSION: Systemic inflammation is closely associated with sarcopenia and poor functional outcomes in the recovery stage of stroke. Early detection of systemic inflammation and sarcopenia can help promote both adequate exercise and nutritional support to restore muscle mass and improve post-stroke functional recovery.

Occult spinal canal stenosis due to C-1 hypoplasia in children with Down syndrome.

OBJECT: Little has been published about subclinical spinal canal stenosis due to C-1 hypoplasia in patients with Down syndrome. In this paper the authors performed a matched comparison study with cross-sectional survey to investigate occult spinal canal stenosis due to C-1 hypoplasia in children with Down syndrome. METHODS: A total of 102 children with Down syndrome ranging in age from 10 to 15 years were matched according to age and physique with 176 normal children. In all participants, the anteroposterior (AP) diameter of C-1 and the atlas-dens interval (ADI) were measured on plain lateral x-ray images of the cervical spine. The cross-sectional area of the atlas was also measured from a cross-sectional computed tomography image of C-1. RESULTS: Eight children (6.7%) with Down syndrome developed atlantoaxial subluxation associated with myelopathy. The difference in the ADI between the patients and controls was not statistically significant. The average AP diameter of the atlas and the spinal canal area along the cross-section of the atlas were significantly smaller in children with Down syndrome than those in the control group. CONCLUSIONS: Atlantoaxial instability and occult spinal canal stenosis due to C-1 hypoplasia in patients with Down syndrome may significantly increase the risk of myelopathy.

Large-scale screening for candidate genes of ossification of the posterior longitudinal ligament of the spine.

Ossification of the posterior longitudinal ligament of the spine (OPLL) is the predominant myelopathy among Japanese, and is usually diagnosed by ectopic bone formation in the paravertebral ligament in Japanese and other Asians. To detect genetic determinants associated with OPLL, we performed an extensive nonparametric linkage study with 126 affected sib-pairs using markers for various candidate genes by distinct analyses, SIBPAL and GENEHUNTER. Eighty-eight candidate genes were selected by comparing the genes identified by complementary DNA (cDNA) microarray analysis of systematic gene expression profiles during osteoblastic differentiation of human mesenchymal stem cells with the genes known to be involved in bone metabolism. Of the 24 genes regulated during osteoblastic differentiation, only one, the alpha B crystalline gene, showed evidence of linkage (p = 0.016, nonparametric linkage [NPL] score = 1.83). Of 64 genes known to be associated with bone metabolism, 7 showed weak evidence of linkage by SIBPAL analysis (p < 0.05): cadherin 13 (CDH13), bone morphogenetic protein 4 (BMP4), proteoglycan 1 (PRG1), transforming growth factor beta 3 (TGFb3), osteopontin (OPN), parathyroid hormone receptor 1 (PTHR1), and insulin-like growth factor 1 (IGF1). Among these genes, BMP4 (NPL = 2.23), CDH13 (NPL = 2.00), TGFb3 (NPL = 1.30), OPN (NPL = 1.15), and PTHR1 (NPL = 1.00) showed evidence of linkage by GENEHUNTER. Only BMP4 reached criteria of suggestive evidence of linkage. Because this gene is a well-known factor in osteogenetic function, BMP4 should be screened in further study for the polymorphism responsible.

Retrospective analysis of neurological outcome after intra-arterial thrombolysis in basilar artery occlusion.

BACKGROUND: Basilar artery occlusion usually has a very poor outcome and is associated with a high mortality rate. Local intra-arterial thrombolysis may improve the clinical outcome and reduce mortality in the treatment of acute basilar artery occlusion. We evaluated the possible variables affecting recanalization and clinical outcome in patients with basilar artery occlusions undergoing thrombolytic therapy. METHODS: We analyzed retrospectively the clinical course and outcome of a series of 26 patients between 1998 and 2001. All patients who were examined within 24 hours after onset of symptoms underwent emergency cerebral angiography and subsequent intra-arterial thrombolysis. Three patients additionally received percutaneous transluminal angioplasty of underlying stenosis at the site of thrombosis. RESULTS: Outcome was good in 9 patients (34.6%) and poor in 17 (65.4%). Recanalization could be achieved in 24 patients (92.3%) and was not affected by age, sex, site of occlusion, etiology, thrombolytic drugs, or time interval. Good outcome was associated with younger age, good initial clinical condition, and no evidence of brain stem infarction. There was no association between the interval (greater or less than 6 hours) from the onset of symptoms until the end of thrombolysis and survival. CONCLUSIONS: We confirm that intra-arterial thrombolysis reduces mortality in basilar artery occlusion. Young patients (<75 years) without any infarct in brain stem before the start of treatment seem to be the ideal candidates for thrombolysis. Basilar artery thrombosis could and should be reopened, even late (after 6 hours) after symptom onset.