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Pain appears to be a leading symptom of many diseases. Patients suffering from chronic pain are of high risk to develop comorbidities coming along with profound personal- and social disadvantages. Knowledge and awareness about pathomechanisms leading to chronic pain, the individual and social consequences of neuropathic pain as result of chronification as well as its high prevalence of therapy resistance are still not common amoung medical professionals. In daily practice patients are either subject to medical neglect in years of suffering or over-diagnosed and -treated. Pathophysiologically every pain condition depending on duration und intensity and independent from origin will provoke ongoing structural and functional changes in pain-conducting, -processing and -controlling parts of the nervous system. The resulting pain syndromes, which acquire neuropathic features along the chronification process, exhibit increasing resistance to conventional therapies. To recognize neuropathic pain components, in order to initiate correct diagnostics appears to be the first challenge. The second challenge includes the timely initiation of the correct therapy, in order to prevent further chronification. Only a third of the patients suffering from chronic neuropathic pain can be treated sufficiently using conservative strategies as medicated therapy, psycho-, physio- or occupational therapy in the long run. Different interventional treatment strategies have proven to be effective on short-, middle- or long-term outcome. Modern, minimally invasive methods of neuromodulation as spinal cord stimulation (SCS) and dorsal root ganglion stimulation (DRG) represent additional and effective options for pain management regarding individual improvement of pain and quality of life as well as the entailing costs. [ABSTRACT FROM AUTHOR]

Objective: To assess which radiological alignment parameters are associated with a satisfactory long‐term clinical outcome after performing lumbar spinal fusion for treating degenerative spondylolisthesis. Methods: This single‐center prospective study assessed the relation between radiological alignment parameters measured on standing lateral lumbar spine radiographs and the patient‐reported outcome using four different questionnaires (COMI, EQ‐5D, ODI and VAS) as primary outcome measures (level of evidence: II). The following spinopelvic alignment parameters were used: gliding angle, sacral inclination, anterior displacement, sagittal rotation, lumbar lordosis, sacral slope, pelvic tilt and pelvic incidence. Furthermore, the length of stay and perioperative complications were documented. Only cases from 2013 to 2015 of low‐grade degenerative lumbar spondylolisthesis (Meyerding grades I and II) were considered. The patients underwent open posterior lumbar fusion surgery by pedicle screw instrumentation and cage insertion. The operative technique was either a posterior lumbar interbody fusion (PLIF) or a transforaminal lumbar interbody fusion (TLIF) performed by three different senior orthopedic surgeons. Exclusion criteria were spine fractures, minimally invasive techniques, underlying malignant diseases or acute infections, previous or multisegmental spine surgery as well as preoperative neurologic impairment. Of 89 initially contacted patients, 17 patients were included for data analysis (11 males, six females). Results: The data of 17 patients after mono‐ or bisegmental lumbar fusion surgery to treat low‐grade lumbar spondylolisthesis and with a follow‐up time of least 72 months were analyzed. The mean age was 66.7 ± 11.3 years. In terms of complications two dural tears and one intraoperative bleeding occurred. The average body mass index (BMI) was 27.6 ± 4.4 kg/m2 and the average inpatient length of stay was 12.9 ± 3.8 days (range: 8–21). The long‐term clinical outcome correlated significantly with the change of the pelvic tilt (rs = −0.515, P < 0.05) and the sagittal rotation (rs = −0.545, P < 0.05). The sacral slope was significantly associated with the sacral inclination (rs = 0.637, P < 0.01) and the pelvic incidence (rs = 0.500, P < 0.05). In addition, the pelvic incidence showed a significant correlation with the pelvic tilt (rs = 0.709, P < 0.01). The change of the different clinical scores over time also correlated significantly between the different questionnaires. Conclusions: The surgical modification of the pelvic tilt and the sagittal rotation are the two radiological alignment parameters that can most accurately predict the long‐term clinical outcome after lumbar interbody fusion surgery. [ABSTRACT FROM AUTHOR]

Purpose: Various pathologies of the lumbosacral junction require fusion of the L5/S1 segment. However, pseudarthroses, which often come along with sacral screw loosening, are problematic. The aim of the present investigation was to elaborate the morphological features of the L5/S1 segment to define a so-called "safe zone" for bi- or tricortical screw placement without risking a damage of the iliac vessels. Methods: A total of one hundred computed tomographies of the pelvis were included in this investigation. On axial and sagittal slices, pedicle morphologies, the prevertebral position of the iliac vessels, the spinal canal and the area with the largest bone density were analyzed. Results: Beginning from the entry point of S1-srews iliac vessels were located at an average angle of 7° convergence, the spinal canal at 38°. Bone density was significantly higher centrally with a mean value of 276 Hounsfield Units compared to the area of the Ala ossis sacri. The largest intraosseous screw length could be achieved at an angle of 25°. The average pedicle width was 20 mm and the pedicle height 13 mm. Conclusions: A "safe-zone" for bicortical screw placement at S1 with regard to the course of the iliac vessels could be defined between 7° and 38° convergence. Regarding the area offering the largest bone density and the maximal possible screw length, a convergence of 25° is recommended at S1 to reduce the incidence of screw loosening. Screw diameter, as a further influence factor on screw holding, is limited by pedicle height not pedicle width. [ABSTRACT FROM AUTHOR]

Introduction: Lumbar and lumbosacral spinal fusion is an established procedure for the treatment of degenerative spondylolisthesis. However, the impact of reduction in the affected segment and of improvement in the radiological sagittal parameters on the clinical outcome remains unclear. Purpose of the study is to analyze the correlation between the radiological sagittal parameters and clinical outcome after lumbar spinal fusion in low-grade degenerative spondylolisthesis.Materials and Methods: In a monocentric prospective, clinical study, patients with low-grade degenerative spondylolisthesis of a single lumbar segment have been included. All patients received a lumbar spinal fusion according to the pathology of the treated segment. Patients attended clinical and radiological follow-up examination 1 and 2 years postoperatively. Clinical outcome was assessed using the Core Outcome Measurement Index (COMI), the Oswestry Disability Index (ODI) and the EuroQol 5D. The sagittal spinopelvic radiological parameters, sagittal rotation and anterior displacement of the affected segment and lumbar lordosis were assessed. The correlation between the sagittal radiological parameters and clinical outcome was analyzed using Spearman-Rho bi-serial test.Results: Sixty-two patients (35 female and 27 male) with an average age of 59.3 years were included in the study. All patients completed the follow-up examinations. Significant improvement in COMI, ODI and EuroQol 5D scores was shown in all follow-up examinations. Significant reduction in the anterior displacement was measured postoperatively, which was preserved during the follow-up. However, no correlation could be demonstrated between reduction in anterior displacement and improvement in clinical outcome. Nonetheless, correlation between correction of sagittal rotation and clinical outcome was shown.Conclusions: Reduction in anterior displacement of the affected segment in the surgical treatment of low-grade degenerative spondylolisthesis does not have an impact on the clinical outcome. [ABSTRACT FROM AUTHOR]

Bicortical screw fixation is an established technique to increase screw strength in vertebral bodies, although it is associated with several complications, for example screw-loosening. Cement augmentation can increase stability of screw-fixation but can also cause various complications, such as cement-leakage or cement embolism. In this study, we tested a new, multicortical screw fixation technique in the sacrum. Four fresh-frozen sacrums were used. In group 1, standard screw insertion, with sagittal parallel and axial convergent screw-drive was performed. In group 2, the screw-drive of the first screw was similar to the screw-drive in group 1. In addition, a second screw was inserted descending into the intended hole in the head of the screw and at a stable angle. Therefore, the screws of the multiloc humerus nail-system (Synthes) were used. The specimens were connected to a testing-machine and underwent cyclic axial loading with an increase in the load after each completed stage. Multicortical screw fixation leads to a significant increase in the number of completed cycles and a significantly increased load until failure. Multicortical screw fixation in the sacrum offers a stronger attachment of the screws. In the future, multicortical implants, which fulfil the criteria demanded in spine surgery, can offer higher stability and may decrease the loosening rates of the implanted screws. • Sacral bicortical screw fixation is commonly used for strength and stability. • This study tested a new, multicortical screw fixation technique. • Fresh-frozen sacrums were used to compare bicortical and multicortical techniques. • Multicortical screw fixation resulted in more strength, stability and load bearing. [ABSTRACT FROM AUTHOR]

If conservative treatment of osteoporotic vertebral compression fractures fails, vertebro- or kyphoplasty is indicated. Usually, polymethylmethacrylate cement (PMMA) is applied coming along with many disadvantageous features. Aluminum-free glass-polyalkenoate cement (GPC) appears to be a benefit alternative material. This study aimed at comparing the mean stress values in human vertebrae after kyphoplasty with PMMA and GPC (IlluminOss™) at hand of a finite element analysis. Three models were created performing kyphoplasty using PMMA or IlluminOss™, respectively, at two native, human lumbar vertebrae (L4) while one remains intact. Finite element analysis was performed using CT-scans of every vertebra. Moreover the PMMA-treated vertebra was used as a model as analyses were executed using material data of PMMA and of GPC. The unimpaired, spongious bone showed potentials of 0.25 MPa maximally. After augmentation stress levels showed fivefold increase, rising from externally to internally, revealing stress peaks at the ventral border of the spinal canal. At central areas of cement 1 MPa is measured in both types of cement. Around these central areas the von Mises stress decreased about 25-50% (0.5-0.75 MPa). If workload of 500 N was applied, the stress appeared to be more centralized at the IlluminOss™-model, similar to the unimpaired. Considering the endplates the GPC model also closely resembles the unimpaired. Comparing the PMMA-treated vertebral body and the GPC-simulation, there is an obvious difference. While the PMMA-treated model showed a central stress peak of 5 MPa, the GPC-simulation of the same vertebral body presents lower stress of 1.2-2.5 MPa. Finite element analysis showed that IlluminOss™ (GPC), used in kyphoplasty of vertebral bodies, creates lower level stress and strain compared to standardly used PMMA, leading to lower stress concentrations on the cranial and caudal vertebral surface especially. GPC appears to own advantageous biological and clinical relevant features. [ABSTRACT FROM AUTHOR]

Traumatic atlantoaxial dislocation due to ligamentous and combined osseous injuries rarely occurs in adults. There are only few cases published in the literature. In this level 4 study, a cohort of nine consecutive patients suffering from traumatic atlantoaxial dislocation has been analyzed regarding morphology of injury, trauma mechanism, and outcome since 2007. Three types of those injuries have been found regarding direction of dislocation indicating the underlying ligamentous injuries as well as the accompanying grade of instability. Firstly, there was rotatory dislocation, if the alar ligaments were injured. Secondly, there occurred horizontal dislocation, when transverse atlantal ligament was damaged additionally. Thirdly, excessive ligamentous injury led to distraction of the atlantoaxial complex resulting in dissociation of the atlas against the axis. Additionally fractures of the atlas as well as of the odontoid process (type II or III according to Anderson/D'Alonzo) were diagnosed frequently. Atlantoaxial dislocation injuries, especially distraction injuries, offer a high risk for accompanied neurovascular disorders deserving reduction followed by surgical fixation. Only rotatory injuries leading to ligamentous damage solitarily can safely be successfully treated conservatively. Understanding of the injuries' morphology is essential, in order to set the correct diagnosis and to implicate the most advantageous treatment regime. [ABSTRACT FROM AUTHOR]

Myelotomy is a surgical procedure allowing removal of extravasated blood and necrotic tissue that is thought to attenuate secondary injury as well as promote recovery in experimental spinal cord injury (SCI) models and humans. Here we examined in rat whether myelotomy at 48 h after low-thoracic compressive SCI provided any benefit over a 12 week period. Compared to animals receiving SCI alone, myelotomy worsened BBB scores (p < 0.05) and also did not improve plantar stepping, ladder climbing, urinary bladder voiding or sensory function (thermal latency) during the 12-week period. Quantitative analyses of tissue sections at 12 weeks showed that myelotomy also did not reduce lesion volume nor alter immunohistochemical markers of axons in spared white matter bridges, microglia, astrocytes or serotinergic fibres. However, myelotomy reduced synaptophysin expression, a marker of synaptic plasticity. We conclude that further studies are required to evaluate myelotomy after SCI. ( 142 words ). [ABSTRACT FROM AUTHOR]

Previous studies have shown coherence between obesity and higher rates of complications following spinal surgery. However, there is a lack of information about the influence of obesity and the mass of outer abdominal fat (OAF) on adjacent segment instability after spinal fusion surgery. Radiographs of 194 patients with spinal fusion surgery were assessed retrospectively. Radiographs were performed after surgery during two years' follow-up and signs of adjacent segment instability were documented. Patients were classified regarding their BMI and extent of OAF was assessed using CT at the umbilical level. In 20 patients (10.3%) instability of adjacent segments occurred during followup. In this cohort mean OAF was significantly thicker (28.07 mm) compared to the patients without instability (22.39) (P=0.038). A total of 45% of patients with instability showed OAF of more than 30 mm at time of intervention compared to 10% in those without signs of instability. There exists significant correlation between the extent of OAF and development of adjacent segment instability postoperatively. Thus, weight reduction before spinal surgery could potentially decrease risk of adjacent segment instability. [ABSTRACT FROM AUTHOR]

The new cluster compound K3Ga11-xInx, which exhibits a very small In/Ga phase width of x = 1.16 to 1.36 only, was obtained in the course of a systematic synthetic, crystallographic and bond theoretical investigation of mixed potassium trielides of the ternary system K-In-Ga. The compound, which was synthesized from nearly stoichiometric amounts of the elements at a maximum temperature of 500 °C, crystallizes in a new orthorhombic crystal structure type [space group Cmmm, a = 1577.9(5), b = 3355.1(8), c = 655.2(2) pm, Z = 10, R1 = 0.0471]. In the complex polyanion, the triels form two crystallographically different [Ga12] icosahedra, which are present in a 1:2 ratio and a previously unknown [M13] "double-cluster" consisting of two vertex-sharing [M7] pentagonal bipyramids. All clusters are connected among each other and via a four-bonded pure In and Ga atom [In(1), Ga(1)]. The polyanion of the compound with the overall formula K15M55 can thus be split up according to [Ga(1x)12][Ga(2x)12]2[M(3x)13]In(1)4Ga(1)2. Herein, the all-exo bonded closo icosahedra carry a charge of -2, the six four-bonded In/Ga contribute with a charge of -6 and the new [M13] "double-cluster" thus carries a charge of -3. Under the reasonable assumption of an "intermediate" interaction between the two cluster fragements, this charge, i.e. the presence of 15 skeleton electron pairs, is in accordance with the mno electron counting rules. FP-LAPW DFT band structure calculations of two ordered model compounds support this interpretation: The tDOS exhibits a small bandgap and the electron density map suggests a limited additional interaction between the Ga5 bases of the two bipyramidal cluster fragments. [ABSTRACT FROM AUTHOR]

Diameters of anterior and posterior atlantodental intervals (AADI and PADI) are diagnostically conclusive regarding ongoing neurological disorders in rheumatoid arthritis. MRI and X-ray are mostly used for patients’ follow-up. This investigation aimed at analyzing these intervals during motion of cervical spine, when transverse and alar ligaments are damaged. AADI and PADI of 10 native, human cervical spines were measured using lateral fluoroscopy, while the spines were assessed in neutral position first, in maximal inclination second, and in maximal extension at last. First, specimens were evaluated under intact conditions, followed by analysis after transverse and alar ligaments were destroyed. Damage of the transverse ligament leads to an increase of the AADI’s diameter about 0.65 mm in flexion and damage of alar ligaments results in significant enhancement of 3.59 mm at mean. In extension, the AADI rises 0.60 mm after the transverse ligament was cut and 0.90 mm when the alar ligaments are damaged. After all ligaments are destroyed, AADI assessed in extension closely resembles AADI at neutral position. Ligamentous damage showed an average significant decrease of the PADI of 1.37 mm in the first step and of 3.57 mm in the second step in flexion, while it is reduced about 1.61 mm and 0.41 mm in the extended and similarly in the neutrally positioned spine. Alar and transverse ligaments are both of obvious importance in order to prevent AAS and movement-related spinal cord compression. Functional imaging is necessary at follow-up in order to identify patients having an advanced risk of neurological disorders. [ABSTRACT FROM AUTHOR]

Purpose: The technique of pedicle screw stabilization is finding increasing popularity for use in the cervical spine. Implementing anterior transpedicular screws (ATPS) in cervical spine offers theoretical advantages compared to posterior stabilization. The goal of the current study was the development of a new setting for navigated insertion of ATPS, combining the advantage of reduced invasiveness of an anterior approach with the technical advantages of navigation.Methods: 20 screws were implanted in levels C3 to C6 of four cervical spine models (SAWBONES(®) Cervical Vertebrae with Anterior Ligament) with the use of 3D fluoroscopy navigation system [Arcadis Orbic 3D, Siemens and VectorVision fluoro 3D trauma software (BrainLAB)]. The accuracy of inserted screws was analyzed according to postoperative CT scans and following the modified Gertzbein and Robbins classification.Results: 20 anterior pedicle screws were placed in four human cervical spine models. Of these, eight screws were placed in C3, two screws in C4, six screws in C5, and four screws in C6. 16 of 20 screws (80 %) reached a grade 1 level of accuracy according to the modified Gertzbein and Robbins Classification. Three screws (15 %) were grade 2, and one screw (5 %) was grade 3. Grade 4 and 5 positions were not evident. Summing grades 1 and 2 together as "good" positions, 95 % of the screws achieved this level. Only a single screw did not fulfill these criteria.Conclusion: The setting introduced in this study for navigated insertion of ATPS into cervical spine bone models is well implemented and shows excellent results, with an accuracy of 95 % (Gertzbein and Robbins grade 2 or better). Thus, this preliminary study represents a prelude to larger studies with larger case numbers on human specimens. [ABSTRACT FROM AUTHOR]

The Iho670 fibers of the hyperthermophilic crenarchaeon of Ignicoccus hospitalis were shown to contain several features that indicate them as type IV pilus-like structures. The application of different visualization methods, including electron tomography and the reconstruction of a three-dimensional model, enabled a detailed description of a hitherto undescribed anchoring structure of the cell appendages. It could be identified as a spherical structure beneath the inner membrane. Furthermore, pools of the fiber protein Iho670 could be localized in the inner as well as the outer cellular membrane of I. hospitalis cells and in the tubes/vesicles in the intermembrane compartment by immunological methods. [ABSTRACT FROM AUTHOR]

Abstract: The goal of this study was to investigate the effect of plasma treatment on the wettability and dissolution of fenofibrate compacts. Contact angle measurements and intrinsic dissolution rate studies of untreated and plasma-treated fenofibrate compacts were conducted. The contact angle data clearly show that the wettability of the tablet surface increased with the duration of plasma treatment. Analyses of stability revealed that the surfaces which were plasma-treated for more than 1min regained some degree of hydrophobicity after storage in air. Since their hydrophobic recovery finally reached the level observed with 1min plasma-treated fenofibrate compacts it was deduced that permanent incorporation of hydrophilic groups had already attained saturation upon plasma irradiation for 1min. Dissolution studies revealed the advantages of the hydrophilized surface of plasma-treated fenofibrate compacts. Due to the improved wettability of plasma-treated fenofibrate its intrinsic dissolution rate was vastly increased compared to untreated fenofibrate. This study thus demonstrates the potential of plasma treatment to enhance the wettability and dissolution behavior of poorly water-soluble drugs. [Copyright &y& Elsevier]

ATP synthase catalyzes ATP synthesis at the expense of an electrochemical ion gradient across a membrane that can be generated by different exergonic reactions. Sulfur reduction is the, main energyyielding reaction in the hyperthermophilic strictly anaerobic Crenarchaeon Ignicoccus hospitalis. This organism is unusual in having an inner and an outer membrane that are separated by a huge intermembrane compartment. Here we show, on the basis of immuno-EM analyses of ultrathin sections and immunofluorescence experiments with whole I. hospitalis cells, that the ATP synthase and H2:sulfur oxidoreductase complexes of this organism are located in the outer membrane. These two enzyme complexes are mandatory for the generation of an electrochemical gradient and for ATP synthesis. Thus, among all prokaryotes possessing two membranes in their cell envelope (including Planctomycetes, Gram-negative bacteria), I. hospitalis is a unique organism, with an energized outer membrane and ATP synthesis within the periplasmic space. In addition, DAPI staining and EM analyses showed that DNA and ribosomes are localized in the cytoplasm, leading to the conclusion that in I. hospitalis energy conservation is separated from information processing and protein biosynthesis. This raises questions regarding the function of the two membranes, the interaction between these compartments, and the general definition of a cytoplasmic membrane. [ABSTRACT FROM AUTHOR]

Background: Microglial activation is one hallmark of Alzheimer disease (AD) neuropathology but the impact of the regional interplay of microglia cells in the brain is poorly understood. We hypothesized that microglial activation is regionally synchronized in the healthy brain but experiences regional desynchronization with ongoing neurodegenerative disease. We addressed the existence of a microglia connectome and investigated microglial desynchronization as an AD biomarker. Methods: To validate the concept, we performed microglia depletion in mice to test whether interregional correlation coefficients (ICCs) of 18 kDa translocator protein (TSPO)-PET change when microglia are cleared. Next, we evaluated the influence of dysfunctional microglia and AD pathophysiology on TSPO-PET ICCs in the mouse brain, followed by translation to a human AD-continuum dataset. We correlated a personalized microglia desynchronization index with cognitive performance. Finally, we performed single-cell radiotracing (scRadiotracing) in mice to ensure the microglial source of the measured desynchronization. Results: Microglia-depleted mice showed a strong ICC reduction in all brain compartments, indicating microglia-specific desynchronization. AD mouse models demonstrated significant reductions of microglial synchronicity, associated with increasing variability of cellular radiotracer uptake in pathologically altered brain regions. Humans within the AD-continuum indicated a stage-depended reduction of microglia synchronicity associated with cognitive decline. scRadiotracing in mice showed that the increased TSPO signal was attributed to microglia. Conclusion: Using TSPO-PET imaging of mice with depleted microglia and scRadiotracing in an amyloid model, we provide first evidence that a microglia connectome can be assessed in the mouse brain. Microglia synchronicity is closely associated with cognitive decline in AD and could serve as an independent personalized biomarker for disease progression. [ABSTRACT FROM AUTHOR]

Purpose The atlantoaxial joint represents the most mobile joint complex within the spine, secured by ligaments and capsules. Integrity of the atlantoaxial joint is crucial with respect to the mobility of the head and the upper spine. Atlantoaxial rotatory dislocation is the most common type of injury within this joint in children and is characterized by a typical position of the head (cock robin position). Nevertheless, this type of injury is frequently overlooked. The purpose of the current study was threefold. First, the characteristics of the patients with atlantoaxial dislocation were identified. Next, we checked if the time to treatment did influence the type of treatment. Finally, we checked if the age of the child at the time of treatment influenced the type of treatment. Methods Forty-four children, who were treated consecutively due to atlantoaxial dislocation at a single spine center between September 1993 and October 2018, are analyzed retrospectively regarding age, sex, symptoms, etiology, time to diagnosis, time to treatment, and outcome. Results Forty-four children (30 girls, mean age 8.9 years) were included in the study. The cock robin head position was found in all of them, but neurological deficits were not found in any of them. In 21 patients, dislocation was caused by previous infection (Grisel's syndrome), whereas in 19 patients, dislocation was due to minor trauma. In 4 cases, etiology remained unknown. Mean time to sufficient treatment was 178 days. Eighteen patients received closed reduction and immobilization after 57 days at mean. Open reduction followed by temporary fixation was done in 12 patients after a mean time gap of 188 days. Bony atlantoaxial fusion was necessary in 14 children, who were diagnosed after 319 days on average. Invasiveness of treatment was dependent on the time delay between development of dislocation and treatment; a significant difference was found between invasiveness of treatment and time to treatment (Kruskal–Wallis test, p < 0,05). Moreover, older children were treated significantly more often with fusion than younger ones (χ 2 , p = 0,002). Conclusion Young girls are predisposed to incur an atlantoaxial rotatory dislocation, which usually occurs due to minor trauma or infection. The cock robin position is characteristic, but neurological deficits are not common. There is a need for early and sufficient treatment because delayed treatment necessitates more invasive treatment, thus leading to a complete loss of function of the most mobile joint within the spine. Finally, older children are predisposed to more invasive treatment strategies. [ABSTRACT FROM AUTHOR]

Screw loosening is a major complication following spondylodesis. While several modifications increase screw stability, some, such as screw augmentation, are associated with potential complications; new techniques are needed to minimize the risk of screw loosening without increasing complication rates. 13 fresh-frozen human lumbar vertebral bodies (L1 to L5) were dissected. In group 1 (n = 7), pedicle screws were implanted conventionally, while in group 2 (n = 6), the screws were positioned divergent in the sagittal pathway. Screw stability was tested under cyclic axial load; one testing-cycle included 1000 repetitions. The first cycle started with a load of 100 N while the load was increased by +20 N in each following cycle until failure. Failure was defined by either a >5 mm movement of the screw heads or triggering of the switch-off threshold. Average number of cycles until failure was increased in group 2 compared with group 1 (12,046 vs 9761 cycles), as was the average load to failure (Fmax 313 N vs 260 N). Overall, in group 2, the number of cycles until screw loosening or failure increased by 23% (p = 0.28), while the required force increased by 20% (p = 0.3). Statistically significant correlation between BMD and increased number of cycles completed as well as with increased load (p < 0.01) could be observed. The results demonstrate, that divergent screw-drift of pairs of screws in the sagittal plane tends to increase stability, especially in vertebral bodies with lower bone density. Moreover, we could demonstrate a correlation between BMD and stability of screw-fixation. • Lumbar parallel screw fixation is commonly used for strength and stability. • This study tested a new, diverging screw fixation technique. • Fresh-frozen vertebral bodies were used to compare parallel and diverging screw fixation. • Diverging screw fixation tends to offer more strength and stability in poor bone-quality. [ABSTRACT FROM AUTHOR]

Study Design: Four orthopedic spine surgeons measured the radiological parameters of pedicle screws in the cervical spine using apostoperative computed tomography (CT) scan. Purpose: This study analyzed the insertion angle of CT-navigated insertion of pedicle screws in the subaxial cervical spine and classified them according to their position. Overview of Literature: Overall, a pedicle transverse angle of 33.6°-50.2° with a mean angle of 45° relative to the midline has been reported in the literature. Methods: The insertion angles of 87 pedicle screws inserted using CT-based navigation in the subaxial cervical spine were measured in the postoperative CT. The screw positioning was determined according to the modified Gertzbein and Robbins classification. Results: Total 89.3% (n=78) of the pedicle screws inserted using CT-based navigation showed good placement. The mean insertion angle of the pedicle screws that showed good positioning was 29.9°±9.9°. The pedicle screws showing bad positioning had a mean insertion angle of 26.8°±10.5° (p =0.157). The interobserver reliability showed a reliable measurement intraclass correlation coefficient: 0.994 (95% confidence interval, 0.992-0.996). Conclusions: The present results show that the insertion angle of the pedicle screws in the subaxial cervical spine was smaller than the actual pedicle transverse angle, as per the literature. One reason for this discrepancy could be that the navigation systems allow the insertion of cervical pedicle screws with a lower convergence. [ABSTRACT FROM AUTHOR]

• Biomechanical simulation of axial force induction testing C1/2 Harms Construct. • Lateral Mass screws construct resulted from 142.04 µm/m to 188.54 µm/m. • Pedicle screws construct resulted from 165.98 µm/m to 195.95 µm/m. • Pedicle screws in a C1/2 Harms Construct were not superior compared to lateral mass screws. The use of the posterior arch of C1 as pedicle has shown beneficial stability regarding screw loosening, however, the C1 pedicle screw placement is challenging. Therefore, the study aimed to analyse the bending forces of the Harms construct used in fixation of C1/C2 when using pedicle screws compared to lateral mass screws. Five cadaveric specimens with a mean age of 72 years at death and bone mineral density measuring for 512.4 Hounsfield Units (HU) on average were used. A custom-made biomechanical setup was used to test the specimens with a C1/C2 Harms construct each with the use of lateral mass screws and pedicle screws in sequence. Strain gauges were used to analyse the bending forces from C1 to C2 in cyclic axial compression (μm/m). All underwent cyclic biomechanical testing using 50, 75 and 100 N. In all specimens, placement of lateral mass screws and pedicle screws was feasible. All underwent cyclic biomechanical testing. For the lateral mass screw, a bending of 142.04 µm/m at 50 N, 166.56 µm/m at 75 N and 188.54 µm/m at 100 N was measured. For the pedicle screws, bending force was slightly elevated with 165.98 µm/m at 50 N, 190.58 µm/m at 75 N and 195.95 µm/m at 100 N. However, bending forces did not vary significantly. In all measurements, no statistical significance was found when comparing pedicle screws and lateral mass screws. The lateral mass screw used in the Harms Construct to stabilize C1/2 showed less bending forces, therefore the construct with lateral mass screws appears more stable in axial compression compared to the one with pedicle screws. However, bending forces did not vary significantly. [ABSTRACT FROM AUTHOR]

Study Design: This single-center retrospective study analyzed patients with chronic low back pain (CLBP) who underwent endoscopic facet joint denervation (EFJD) between April 2018 and May 2019. Purpose: This study was designed to investigate the effectiveness of EFJD in treating CLBP. Overview of Literature: CLBP is a challenging burden to healthcare systems worldwide. As up to 45% of cases originate from the lumbar facet joints, sufficient therapy strategies must be developed. EFJD offers a precise depiction of the dorsal medial ramus and the facet joint capsule. Methods: In this study, 64 patients who underwent EFJD were included. The main outcome of interest was patients' Visual Analog Scale (VAS) pain score, which was recorded at 3-time points (i.e., before operation and 6 weeks and 12 months after surgery). Results: EFJD effectively reduced the VAS pain scores by 58% in the short term (6 weeks) and 38% in the long term (12 months). Patients with isolated facet joint osteoarthritis benefited more (p <0.001). Conclusions: EFJD is a good treatment alternative for CLBP originating from the facet joints, particularly in patients with isolated facet joint osteoarthritis. Moreover, this method can address not only the dorsal medial ramus but also the surrounding tissue (e.g., facet joint capsule, facet joint effusion, and osteophytes) as the origin of CLBP. [ABSTRACT FROM AUTHOR]

Ignicoccus hospitalis forms many cell surface appendages, the Iho670 fibers (width, 14 nm; length, up to 20 μm), which constitute up to 5% of cellular protein. They are composed mainly of protein Iho670, possessing no homology to archaeal flagellins or fimbrins. Their existence as structures different from archaeal flagella or fimbriae have gone unnoticed up to now because they are very brittle. [ABSTRACT FROM AUTHOR]

Communicative alignment refers to adaptation to one's communication partner. Temporal aspects of such alignment have been little explored. This article examines temporal aspects of lexical and syntactic alignment (i.e., tendencies to use the interlocutor's lexical items and syntactic structures) in task-oriented discourse. In particular, we investigate whether lexical and syntactic alignment increases throughout the discourse and whether alignment contributes to speedy task completion. We present data from a text-based chat game in which participants instructed each other on where to place objects in a grid. Our methodological approach allows calculating a robust baseline and revealed reliable lexical and syntactic alignment. However, only lexical alignment, but not syntactic alignment, was sensitive to temporal aspects in that only lexical alignment increased throughout the discourse and positively affected task completion time. We discuss how these results relate to the communicative task and mention implications for models of alignment. [ABSTRACT FROM PUBLISHER]

Colloidal iron oxides (FeOx) are increasingly released to the environment due to their use in environmental remediation and biomedical applications, potentially harming living organisms. Size and composition could affect the bioavailability and toxicity of such colloids. Therefore, we investigated the toxicity of selected FeOx with variable aggregate size and variably composed FeOx-associated organic matter (OM) toward the nematode Caenorhabditis elegans. Ferrihydrite colloids containing citrate were taken up by C. elegans with the food and accumulated inside their body. The toxicity of ferrihydrite, goethite, and akaganeite was dependent on aggregate size and specific surface area, with EC50 values for reproduction ranging from 4 to 29 mg Fe L-1. Experiments with mutant strains lacking mitochondrial superoxide dismutase (sod-2) showed oxidative stress for two FeOx and Fe3+-ions, however, revealed that it was not the predominant mechanism of toxicity. The OM composition determined the toxicity of mixed OM-FeOx phases on C. elegans. FeOx associated with humic acids or citrate were less toxic than OM-free FeOx. In contrast, soil-derived ferrihydrite, containing proteins and polysaccharides from mobile OM, was even more toxic than OM-free Fh of similar aggregate size. Consequently, the careful choice of the type of FeOx and the type of associated OM may help in reducing the ecological risks if actively applied to the subsurface. [ABSTRACT FROM AUTHOR]

Abstract: Bacterial motility is driven by the rotation of flagellar filaments that supercoil. The supercoiling involves the switching of coiled-coil protofilaments between two different states. In archaea, the flagellar filaments responsible for motility are formed by proteins with distinct homology in their N-terminal portion to bacterial Type IV pilins. The bacterial pilins have a single N-terminal hydrophobic α-helix, not the coiled coil found in flagellin. We have used electron cryo-microscopy to study the adhesion filaments from the archaeon Ignicoccus hospitalis. While I. hospitalis is non-motile, these filaments make transitions between rigid stretches and curved regions and appear morphologically similar to true archaeal flagellar filaments. A resolution of ~7.5Å allows us to unambiguously build a model for the packing of these N-terminal α-helices, and this packing is different from several bacterial Type IV pili whose structure has been analyzed by electron microscopy and modeling. Our results show that the mechanism responsible for the supercoiling of bacterial flagellar filaments cannot apply to archaeal filaments. [Copyright &y& Elsevier]

Ignicoccus hospitalis, a hyperthermophilic, chemolithoautotrophic crenarchaeon was found to possess a new CO2 fixation pathway, the dicarboxylate/4-hydroxybutyrate cycle. The primary acceptor molecule for this pathway is acetyl coenzyme A (acetyl-CoA), which is regenerated in the cycle via the characteristic intermediate 4-hydroxybutyrate. In the presence of acetate, acetyl-CoA can alternatively be formed in a one-step mechanism via an AMP-forming acetyl-CoA synthetase (ACS). This enzyme was identified after membrane preparation by two-dimensional native PAGE/SDS-PAGE, followed by matrix-assisted laser desorption ionization-time of flight tandem mass spectrometry and N-terminal sequencing. The ACS of I. hospitalis exhibits a molecular mass of ∼690 kDa with a monomeric molecular mass of 77 kDa. Activity tests on isolated membranes and bioinformatic analyses indicated that the ACS is a constitutive membrane-associated (but not an integral) protein complex. Unexpectedly, immunolabeling on cells of I. hospitalis and other described Ignicoccus species revealed that the ACS is localized at the outermost membrane. This perfectly coincides with recent results that the ATP synthase and the H2:sulfur oxidoreductase complexes are also located in the outermost membrane of I. hospitalis. These results imply that the intermembrane compartment of I. hospitalis is not only the site of ATP synthesis but may also be involved in the primary steps of CO2 fixation [ABSTRACT FROM AUTHOR]

Abstract: In the last years Supported Ionic Liquid Phase (SILP) catalysis has attracted growing interest for continuous gas phase reactions. The concept combines in a unique manner the advantages of traditional homogeneous and heterogeneous catalysis by making use of the extremely low vapor pressure of an ionic liquid film on support. In this way, continuous gas phase reactions with macroscopically solid but microscopically homogeneous catalyst materials have been successfully realized. However—so far—continuous gas-phase SILP catalysis has only been demonstrated for reactions with relatively simple selectivity problems (such as, regioselectivity, chemoselectivity). This study demonstrates the successful application of a SILP catalyst in continuous gas phase asymmetric hydrogenation. The hydrogenation of methyl acetoacetate (MAA) is presented using an immobilized dibromo[3-(2,5-(2R,5R)-dimethylphospholanyl-1)-4-di-o-tolylphosphino-2,5-dimethylthio-phene]-ruthenium (Ru1Br2) catalyst. [Copyright &y& Elsevier]

In the biogeography of microorganisms, the habitat size of an attached-living bacterium has never been investigated. We approached this theme with a multilocus sequence analysis (MLSA) study of new strains of Rhodopirellula sp., an attached-living planctomycete. The development of an MLSA for Rhodopirellula baltica enabled the characterization of the genetic diversity at the species level, beyond the resolution of the 16S rRNA gene. The alleles of the nine housekeeping genes acsA, guaA, trpE,purH, glpF,fumC, icd, gIyA, and mdh indicated the presence of 13 genetically defined operational taxonomic units (OTUs) in our culture collection. The MLSA-based OTUs coincided with the taxonomic units defined by DNA-DNA hybridization experiments. BOX-PCR supported the MLSA.based differentiation of two closely related OTUs. This study established a taxon-area relationship of cultivable Rhodopirellula species. In European seas, three closely related species covered the Baltic Sea and the eastern North Sea, the North Atlantic region, and the southern North Sea to the Mediterranean. The last had regional genotypes, as revealed by BOX-PCR. This suggests a limited habitat size of attached-living Rhodopirellula species. [ABSTRACT FROM AUTHOR]

Abstract SCI is followed by dramatic upregulation of chondroitin sulfate proteoglycans (CSPGs) which limit axonal regeneration, oligodendrocyte replacement and remyelination. The recent discovery of the specific CSPGs signaling receptor protein tyrosine phosphatase sigma (RPTPσ) provided an opportunity to refine the therapeutic approach to overcome CSPGs inhibitory actions. In previously published work, subcutaneous (s.c.) delivery of 44 μg/day of a peptide mimetic of PTPσ called intracellular sigma peptide (ISP), which binds to PTPσ and blocks CSPG-mediated inhibition, facilitated recovery after contusive SCI. Since this result could be of great interest for clinical trials, we independently repeated this study, but modified the method of injury as well as peptide application and the dosage. Following SCI at the Th10-segment, 40 rats were distributed in 3 groups. Animals in group 1 (20 rats) were subjected to SCI, but received no treatment. Rats in group 2 were treated with intraperitoneal (i.p.) injections of 44 μg/day ISP (SCI + ISP44) and animals of group 3 with s.c. injections of 500 μg/day ISP (SCI + ISP500) for 7 weeks after lesioning. Recovery was analyzed at 1, 3, 6, 9 and 12 weeks after SCI by determining (i) BBB-score, (ii) foot-stepping angle, (iii) rump-height index, (iv) number of correct ladder steps, (v) bladder score and (vi) sensitivity (withdrawal latency after thermal stimulus). Finally, we determined the amount of serotonergic fibers in the preserved neural tissue bridges (PNTB) around the lesion site. Our results show that, systemic therapy with ISP improved locomotor, sensory and vegetative recovery which correlated with more spared serotonergic fibers in PNTB. Highlights • ISP was applied two modes: 44 μg/day i.p. and 500 μg/day s.c for 7 weeks after SCI. • Recovery was analyzed at 1, 3, 6, 9 and 12 weeks after SCI. • We determined the spared serotonergic axons in preserved neural tissue bridges (PNTB). • Systemic therapy with ISP improved locomotor, sensory and vegetative recovery. • This correlated with more spared serotonergic fibers in PNTB [ABSTRACT FROM AUTHOR]

Background: We compared functional, electrophysiological and morphological parameters after SCI in two groups of rats Sprague Dawley (SD) rats with normal vision and blind rats from a SD-substrain “Royal College of Surgeons” (SD/RCS) who lose their photoreceptor cells after birth due to a genetic defect in the retinal pigment epithelium. For these animals skin-, intramuscular-, and tendon receptors are major available means to resolve spatial information. Objective: The purpose of this study was to check whether increased sensitivity in SD/RCS rats would promote an improved recovery after SCI. Methods: All rats were subjected to severe compression of the spinal cord at vertebra Th8, spinal cord segment Th10. Recovery of locomotion was analyzed at 1, 3, 6, 9, and 12 weeks after SCI using video recordings of beam walking and inclined ladder climbing. Five functional parameters were studied: foot-stepping angle (FSA), rump-height index (RHI) estimating paw placement and body weight support, respectively, number of correct ladder steps (CLS) assessing skilled hindlimb movements, the BBB-locomotor score and an established urinary bladder score (BS). Sensitivity tests were followed by electrophysiological measurement of M- and H-wave amplitudes from contractions of the plantar musculature after stimulation of the tibial nerve. The closing morphological measurements included lesion volume and expression of astro- and microglia below the lesion. Results: Numerical assessments of BBB, FSA, BS, lesion volume and GFAP-expression revealed no significant differences between both strains. However, compared to SD-rats, the blind SD/RCS animals significantly improved RHI and CLS by 6 – 12 weeks after SCI. To our surprise the withdrawal latencies in the blind SD/RCS rats were longer and the amplitudes of M- and H-waves lower. The expression of IBA1-immunoreactivity in the lumbar enlargement was lower than in the SD-animals. Conclusion: The longer withdrawal latencies suggest a decreased sensitivity in the blind SD/RCS rats, which promotes better recovery after SCI. In this way our results provide indirect support to earlier work showing, that hypersensitivity and chronic pain after contusive SCI impair the recovery of locomotor function. [ABSTRACT FROM AUTHOR]

Background: Following spinal cord injury (SCI), exercise training provides a wide range of benefits and promotes activitydependent synaptic plasticity. Whole body vibration (WBV) in SCI patients improves walking and spasticity as well as bone and muscle mass. However, little is known about the effects of timing or frequency of intervention. Objective: To determine which WBV-onset improves locomotor and bladder functions and influences synaptic plasticity beneficially. Methods: SCI was followed by WBV starting 1, 7, 14, 28 days after injury (WBV1, WBV7, etc.) and continued for 12 weeks. Intact animals and those receiving SCI but no WBV (No WBV), SCI plus WBV twice daily (2×WBV) and SCI followed by passive hindlimb flexion-extension (PFE) served as controls. Locomotor [BBB rating, foot stepping angle (FSA) and rump-height index (RHI)] as well as bladder function were determined at 1, 3, 6, 9, and 12 weeks. Following perfusion fixation at 12 weeks, lesion volume and immunofluorescence for astrogliosis (GFAP), microglia (IBA1) and synaptic vesicles (synaptophysin, SYN) were determined. Results: Compared to the No WBV group, the WB7 and WBV14 groups showed significantly faster speeds of BBB score recovery though this effect was temporary. Considering RHI we detected a sustained improvement in the WBV14 and PFE groups. Bladder function was better in the WBV14, WBV28, 2×WBV and PFE groups. Synaptophysin levels improved in response to WBV7 and WBV14, but worsened after WBV28 in parallel to an increased IBA1 expression. Correlation- and principal components analysis revealed complex relationships between behavioural (BBB, FSA, RHI) and morphological (GFAP, IBA1, SYN) measurements. Conclusions: WBV started 14 days after SCI provides the most benefit (RHI, bladder); starting at 1day after SCI provides no benefit and starting at 28 days may be detrimental. Increasing the intensity of WBV to twice daily did not provide additional benefit. [ABSTRACT FROM AUTHOR]

Ignicoccus hospitalis, a hyperthermophilic, chemolithoautotrophic Crenarchaeon, is the host of Nanoarchaeum equitans. Together, they form an intimate association, the first among Archaea. Membranes are of fundamental importance for the interaction of I. hospitalis and N. equitans, as they harbour the proteins necessary for the transport of macromolecules like lipids, amino acids, and cofactors between these organisms. Here, we investigated the protein inventory of I. hospitalis cells, and were able to identify 20 proteins in total. Experimental evidence and predictions let us conclude that 11 are soluble cytosolic proteins, eight membrane or membrane-associated proteins, and a single one extracellular. The quantitatively dominating proteins in the cytoplasm (peroxiredoxin; thermosome) antagonize oxidative and temperature stress which I. hospitalis cells are exposed to at optimal growth conditions. Three abundant membrane protein complexes are found: the major protein of the outer membrane, which might protect the cell against the hostile environment, forms oligomeric complexes with pores of unknown selectivity; two other complexes of the cytoplasmic membrane, the hydrogenase and the ATP synthase, play a key role in energy production and conversion. [ABSTRACT FROM AUTHOR]

Background: Thoracolumbar spine fractures in multiple-injured patients are a common injury pattern. The appropriate timing for the surgical stabilization of vertebral fractures is still controversial. The purpose of this study was to analyse the impact of the timing of spinal surgery in multiple-injured patients both in general and in respect to spinal injury severity. Methods: A retrospective analysis of multiple-injured patients with an associated spinal trauma within the thoracic or lumbar spine (injury severity score (ISS) >16, age >16 years) was performed from January 2012 to December 2016 in two Level I trauma centres. Demographic data, circumstances of the accident, and ISS, as well as time to spinal surgery were documented. The evaluated outcome parameters were length of stay in the intensive care unit (ICU) (iLOS) and length of stay (LOS) in the hospital, duration of mechanical ventilation, onset of sepsis, and multiple organ dysfunction syndrome (MODS), as well as mortality. Statistical analysis was performed using SPSS. Results: A total of 113 multiple-injured patients with spinal stabilization and a complete dataset were included in the study. Of these, 71 multiple-injured patients (63%) presented with an AOSpine A-type spinal injury, whereas 42 (37%) had an AOSpine B-/C-type spinal injury. Forty-nine multiple-injured patients (43.4%) were surgically treated for their spinal injury within 24 h after trauma, and showed a significantly reduced length of stay in the ICU (7.31 vs. 14.56 days; p < 0.001) and hospital stay (23.85 vs. 33.95 days; p = 0.048), as well as a significantly reduced prevalence of sepsis compared to those surgically treated later than 24 h (3 vs. 7; p = 0.023). These adverse effects were even more pronounced in the case where cutoffs were increased to either 72 h or 96 h. Independent risk factors for a delay in spinal surgery were a higher ISS (p = 0.036), a thoracic spine injury (p = 0.001), an AOSpine A-type spinal injury (p = 0.048), and an intact neurological status (p < 0.001). In multiple-injured patients with AOSpine A-type spinal injuries, an increased time to spinal surgery was only an independent risk factor for an increased LOS; however, in multiple-injured patients with B-/C-type spinal injuries, an increased time to spinal surgery was an independent risk factor for increased iLOS, LOS, and the development of sepsis. Conclusion: Our data support the concept of early spinal stabilization in multiple-injured patients with AOSpine B-/C-type injuries, especially of the thoracic spine. However, in multiple-injured patients with AOSpine A-type injuries, the beneficial impact of early spinal stabilization has been overemphasized in former studies, and the benefit should be weighed out against the risk of patients' deterioration during early spinal stabilization. [ABSTRACT FROM AUTHOR]