Regulation of dendritic spine morphology by the rho family of small GTPases: antagonistic roles of Rac and Rho

Dendritic spines mediate most excitatory transmission in the mammalian CNS and have been traditionally considered stable structures. Following the suggestion that spines may 'twitch', it has been recently shown that spines are capable of rapid morphological rearrangements. Because of the role of the small GTPases from the Rho family in controlling neuronal morphogenesis, we investigated the effects of several members of this biochemical signaling pathway in the maintenance of the morphology of extant dendritic spines by combining biolistic transfection of pyramidal neurons in cultured cortical and hippocampal slices with two-photon microscopy. We find a variety of effects on the density and morphology of dendritic spines by expressing either constitutively active or dominant negative forms of several small GTPases of the Rho family, by blocking the entire pathway with Clostridium difficile toxin B or by blocking Rho with C3 transferase. We propose a model where Rac promotes spine formation, while Rho prevents it. We conclude that the small GTPases provide antagonistic control mechanisms of spine maintenance in pyramidal neurons.     

Computer aided vertebral visualization and analysis: a methodology using the sand rat,a small animal model of disc degeneration

Background

The purpose of this study is to present an automated system that analyzes digitized x-ray images of small animal spines identifying the effects of disc degeneration. The age-related disc and spine degeneration that occurs in the sand rat (Psammomys obesus) has previously been documented radiologically; selected representative radiographs with age-related changes were used here to develop computer-assisted vertebral visualization/analysis techniques. Techniques presented here have the potential to produce quantitative algorithms that create more accurate and informative measurements in a time efficient manner.

Methods

Signal and image processing techniques were applied to digitized spine x-ray images the spine was segmented, and orientation and curvature determined. The image was segmented based on orientation changes of the spine; edge detection was performed to define vertebral boundaries. Once vertebrae were identified, a number of measures were introduced and calculated to retrieve information on the vertebral separation/orientation and sclerosis.

Results

A method is described which produces computer-generated quantitative measurements of vertebrae and disc spaces. Six sand rat spine radiographs illustrate applications of this technique. Results showed that this method can successfully automate calculation and analysis of vertebral length, vertebral spacing, vertebral angle, and can score sclerosis. Techniques also provide quantitative means to explore the relation between age and vertebral shape.

Conclusions

This method provides a computationally efficient system to analyze spinal changes during aging. Techniques can be used to automate the quantitative processing of vertebral radiographic images and may be applicable to human and other animal radiologic models of the aging/degenerating spine.

     

The effects of decompression and exogenous NGF on compressed cerebral cortex

Using a rat epidural bead implantation model, we found that compression alone could reduce the overall and individual layer thicknesses of cerebral cortex with no apparent cell death. The dendritic lengths and spine densities of layer II/III and V pyramidal neurons started to decrease within 3 days of compression. Decompression for 14 days resulted in near complete to partial recovery of the cortical thickness and of the dendritic lengths of layer II/III and V pyramidal neurons, depending on the duration of the preceding compression. The recoverability was better following short (3-day) than long (1- or 3-month) periods of compression. The loss of dendritic spines nevertheless persisted. An intraventricular infusion of NGF was performed after decompressing the lesions following 3 days of cortical compression, and this increased the recovery of the spines but not the dendritic length of the cortical pyramidal neurons, nor did it alter the recovery of the cortical thickness. NGF also promoted the increase of the dendritic spines, but not the dendritic length of the cortical pyramidal neurons of normal animals. In short, the data show that a few days of compression alone can cause permanent cortical damage. Exogenous NGF, if applied topically, may restore the dendritic spine density of cortical neurons subjected to compression.     

Screening for spinal deformities in Minnesota schools

Early detection of spine deformities by school screening has proven to be an effective mechanism for early diagnosis. The forward bending test is a simple rapid method of detection and has been used in the Minnesota State screening program. Screening in Minnesota began in 2 rural communities and spread to include the whole state. Over 570,000 children have been screened to the end of the 1975/1976 school year. The prevalence rate of 4.0% of rational prominences is the same as that found in other screening programs. The findings of a large number of small curves and the nearly equal sex ratio were unexpected, but reflect the recent literature. Even though a large number of normal spines are referred for physician evaluation by the screening, the benefits are great. The curves are detected when they are small, allowing progressive deformities to be detected early, promptly braced and deterioration prevented. The need for future surgical correction is thus decreased. The routine screening in Minnesota of school children for spine deformities has proved to be an effective method for the early detection of spine deformities. The screening test is rapid and easy--"a 30-second investment for a lifetime of dividends."     

Dendritic spine morphology determines membrane-associated protein exchange between dendritic shafts and spine heads

The purpose of this study was to examine whether variability in the shape of dendritic spines affects protein movement within the plasma membrane. Using a combination of confocal microscopy and the fluorescence loss in photobleaching technique in living hippocampal CA1 pyramidal neurons expressing membrane-linked GFP, we observed a clear correlation between spine shape parameters and the diffusion and compartmentalization of membrane-associated proteins. The kinetics of membrane-linked GFP exchange between the dendritic shaft and the spine head compartment were slower in dendritic spines with long necks and/or large heads than in those with short necks and/or small heads. Furthermore, when the spine area was reduced by eliciting epileptiform activity, the kinetics of protein exchange between the spine compartments exhibited a concomitant decrease. As synaptic plasticity is considered to involve the dynamic flux by lateral diffusion of membrane-bound proteins into and out of the synapse, our data suggest that spine shape represents an important parameter in the susceptibility of synapses to undergo plastic change.     

Segmentation of hip cartilage in compositional magnetic resonance imaging: A fast,accurate, reproducible,and clinically viable semi‐automated methodology

Manual segmentation is a significant obstacle in the analysis of compositional MRI for clinical decision‐making and research. Our aim was to produce a fast, accurate, reproducible, and clinically viable semi‐automated method for segmentation of hip MRI. We produced a semi‐automated segmentation method for cartilage segmentation of hip MRI sequences consisting of a two step process: (i) fully automated hierarchical partitioning of the data volume generated using a bespoke segmentation approach applied recursively, followed by (ii) user selection of the regions of interest using a region editor. This was applied to dGEMRIC scans at 3T taken from a prospective longitudinal study of individuals considered at high‐risk of developing osteoarthritis (SibKids) which were also manually segmented for comparison. Fourteen hips were segmented both manually and using our semi‐automated method. Per hip, processing time for semi‐automated and manual segmentation was 10–15, and 60–120 min, respectively. Accuracy and Dice similarity coefficient (DSC) for the comparison of semi‐automated and manual segmentations was 0.9886 and 0.8803, respectively. Intra‐observer and inter‐observer reproducibility of the semi‐automated segmentation method gave an accuracy of 0.9997 and 0.9991, and DSC of 0.9726 and 0.9354, respectively. We have proposed a fast, accurate, reproducible, and clinically viable semi‐automated method for segmentation of hip MRI sequences. This enables accurate anatomical and biochemical measurements to be obtained quickly and reproducibly. This is the first such method that shows clinical applicability, and could have large ramifications for the use of compositional MRI in research and clinically. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:2280–2287, 2018.

     

Effects of synaptic activity on dendritic spine motility of developing cortical layer v pyramidal neurons

It is increasingly clear that dendritic spines play an important role in compartmentalizing post-synaptic signals and that their dynamic morphological properties have functional consequences. Here, we examine this issue using two-photon microscopy to characterize spine motility on layer V pyramidal neurons in acute slices of the developing mouse cortex. In this system, all spine classes except filopodia become less dynamic as development proceeds. General manipulations of activity (TTX or KCl treatment) do not alter spine dynamics, although increased glutamatergic transmission (AMPA or NMDA treatment) stabilizes developing cortical spines. These effects on spine dynamics do not appear to be related to AMPA or NMDA receptor expression as assessed with immunolabeling, as there is no correlation between spine motility and AMPA (GluR1/2) or NMDA (NR1/NR2B) receptor subunit expression on a spine by spine basis. These results indicate that activity through glutamatergic synapses is important for regulating spine motility in the developing mouse cortex, and that the relative complement of receptors, while different across morphological classifications, cannot account for differences in dynamic structural changes in dendritic spines.     

Role of afferent innervation and neuronal activity in dendritic development and spine maturation of fascia dentata granule cells

By using slice cultures of hippocampus as a model, we have studied the development of dendritic spines in fascia dentata granule cells. We raised the question as to what extent spine development is dependent on a major afferent input to these neurons, the fibers from the entorhinal cortex and neuronal activity mediated by these axons. Our results can be summarized as follows: (i) the entorhino-hippocampal projection develops in an organotypic manner in co-cultures of entorhinal cortex and hippocampus. Like in vivo, entorhinal fibers, labeled by anterograde tracing with biocytin, terminate in the outer molecular layer of the fascia dentata. (ii) The layer-specific termination of entorhinal fibers is not altered by the blockade of neuronal activity with tetrodotoxin. Likewise, the differentiation of the dendritic arbor of postsynaptic granule cells does not require neuronal activity. Blockade of neuronal activity did not affect the mean spine number of granule cell dendrites in entorhino-hippocampal co-cultures, but led to a relative increase in thin, long filiform spines that are characteristic of immature neurons. (iii) The maturation of the granule cell dendritic arbor is, however, controlled by the afferent fibers from the entorhinal cortex in an activity-independent manner. In single slice cultures of hippocampus lacking entorhinal input, Golgi-impregnated granule cells have much shorter, less branched dendrites when compared with granule cells in entorhino-hippocampal co-cultures. This reduction in dendritic length in granule cells lacking entorhinal input results in a lower mean total number of spines per neuron, but the mean number of spines per microm is not reduced in the absence of entorhinal innervation. These results indicate that innervation by fibers from the entorhinal cortex, but not neuronal activity mediated via these axons, is essential for the normal development of the granule cell dendritic arbor. Neuronal activity is required, however, for the maturation of dendritic spines.     

Clinical validation of coronal and sagittal spinal curve measurements based on three-dimensional vertebra vector parameters

Background context

For many decades, visualization and evaluation of three-dimensional (3D) spinal deformities have only been possible by two-dimensional (2D) radiodiagnostic methods, and as a result, characterization and classification were based on 2D terminologies. Recent developments in medical digital imaging and 3D visualization techniques including surface 3D reconstructions opened a chance for a long-sought change in this field. Supported by a 3D Terminology on Spinal Deformities of the Scoliosis Research Society, an approach for 3D measurements and a new 3D classification of scoliosis yielded several compelling concepts on 3D visualization and new proposals for 3D classification in recent years. More recently, a new proposal for visualization and complete 3D evaluation of the spine by 3D vertebra vectors has been introduced by our workgroup, a concept, based on EOS 2D/3D, a groundbreaking new ultralow radiation dose integrated orthopedic imaging device with sterEOS 3D spine reconstruction software.

Purpose

Comparison of accuracy, correlation of measurement values, intraobserver and interrater reliability of methods by conventional manual 2D and vertebra vector–based 3D measurements in a routine clinical setting.

Study design

Retrospective, nonrandomized study of diagnostic X-ray images created as part of a routine clinical protocol of eligible patients examined at our clinic during a 30-month period between July 2007 and December 2009.

Patient sample

In total, 201 individuals (170 females, 31 males; mean age, 19.88 years) including 10 healthy athletes with normal spine and patients with adolescent idiopathic scoliosis (175 cases), adult degenerative scoliosis (11 cases), and Scheuermann hyperkyphosis (5 cases). Overall range of coronal curves was between 2.4 and 117.5°. Analysis of accuracy and reliability of measurements was carried out on a group of all patients and in subgroups based on coronal plane deviation: 0 to 10° (Group 1; n=36), 10 to 25° (Group 2; n=25), 25 to 50° (Group 3; n=69), 50 to 75° (Group 4; n=49), and above 75° (Group 5; n=22).

Methods

All study subjects were examined by EOS 2D imaging, resulting in anteroposterior (AP) and lateral (LAT) full spine, orthogonal digital X-ray images, in standing position. Conventional coronal and sagittal curvature measurements including sagittal L5 vertebra wedges were determined by 3 experienced examiners, using traditional Cobb methods on EOS 2D AP and LAT images. Vertebra vector–based measurements were performed as published earlier, based on computer-assisted calculations of corresponding spinal curvature. Vertebra vectors were generated by dedicated software from sterEOS 3D spine models reconstructed from EOS 2D images by the same three examiners. Manual measurements were performed by each examiner, thrice for sterEOS 3D reconstructions and twice for vertebra vector–based measurements. Means comparison t test, Pearson bivariate correlation analysis, reliability analysis by intraclass correlation coefficients for intraobserver reproducibility and interrater reliability were performed using SPSS v16.0 software.

Results

In comparison with manual 2D methods, only small and nonsignificant differences were detectable in vertebra vector–based curvature data for coronal curves and thoracic kyphosis, whereas the found difference in L1–L5 lordosis values was shown to be strongly related to the magnitude of corresponding L5 wedge. Intraobserver reliability was excellent for both methods, and interrater reproducibility was consistently higher for vertebra vector–based methods that was also found to be unaffected by the magnitude of coronal curves or sagittal plane deviations.

Conclusions

Vertebra vector–based angulation measurements could fully substitute conventional manual 2D measurements, with similar accuracy and higher intraobserver reliability and interrater reproducibility. Vertebra vectors represent a truly 3D solution for clear and comprehensible 3D visualization of spinal deformities while preserving crucial parametric information for vertebral size, 3D position, orientation, and rotation. The concept of vertebra vectors may serve as a starting point to a valid and clinically useful alternative for a new 3D classification of scoliosis.     

Automated registration of hip and spine for longitudinal QCT studies: integration with 3D densitometric and structural analysis

To eliminate user interaction in longitudinal quantitative computed tomography (QCT) measurements of bone mineral density (BMD) and geometry, we have developed and optimized an automated registration algorithm for QCT images of the hip and spine and integrated it with a previously developed 3D densitometric and structural analysis program. With registration, the follow-up images are automatically aligned with respect to the baseline scans, and the bone quantification of the aligned follow-up scan is initiated based on the bone morphometric features defined on the baseline scan. To validate the algorithm, we analyzed 20 pairs of repeat QCT images (10 hip pairs and 10 spine pairs) acquired on a modern multi-slice CT scanner, with repositioning between each scan pair to simulate repeat visits. Bone measurements obtained with automatic registration achieved comparable or improved precision errors compared to those obtained by careful manual analysis of the follow-up scans. The algorithm we have developed was based on the mutual information approach, with simplex optimization under a multi-resolution scheme. The average registration time was 2.3 min for a hip pair and 1.1 min for a vertebra pair using a standard desktop computer. Based on the reduced user interaction, high degree of precision, and short execution time, this is a promising technique for monitoring therapy in patients and clinical trials.     

The screening of more than 2,000 schoolgirls for bacteriuria using an automated fluorescence microscopy system

Summary After initial evaluation of a manual fluorescence microscopy system on a variety of urines the method was automated and subsequently tested in a population survey of urinary tract infection in schoolgirls. This automated Bactoscan system allowed a rapid analysis of urine samples and with the introduction of modifications to the staining protocol it correctly eliminated 91% of samples as being not significantly infected.     

Three dimensional analysis of brace biomechanical efficacy for patients with AIS

Purpose

Corrective three dimensional (3D) effect of different braces is debatable. We evaluated differences in in-brace radiographic correction comparing a custom thoracic-lumbo-sacral-orthosis (TLSO) (T) brace to a Chêneau type TLSO (C) brace using 3D EOS reconstruction technology. Our primary research question was the 3D effect of brace on the spine and in particularly the apical vertebra rotation (AVR).

Methods

This was a retrospective comparative analysis of patients with adolescent idiopathic scoliosis who had orthogonal AP and lateral X-rays with and without brace. A 3D image of the spine was reconstructed. Coronal, sagittal and axial spine parameters were measured before bracing and then on the first post-brace X-ray. Brace efficacy in controlling coronal, sagittal and axial parameters was evaluated.

Results

Eighteen patients treated with the C brace and ten patients treated with the T brace were included. No difference was found regarding patients’ age, gender, magnitude of Cobb angle, sagittal parameters or AVR at inclusion. Following bracing, AVR was significantly reduced by the C brace compared to the T brace [average correction of 8.2° vs. 4.9° (P = 0.02)]. Coronal and sagittal correction did not differ significantly between the two groups.

Conclusions

By utilizing a novel 3D reconstruction technology, we were able to demonstrate that braces differ in their immediate effects on the spine. Although clinical relevance should be evaluated in a future trial we feel that the ability to measure treatment effects in 3D, and especially the transverse plane, is an important tool when evaluating different treatments.     

Computer tomography assessment of pedicle screw placement in thoracic spine: comparison between free hand and a generic 3D-based navigation techniques

Introduction

Although pedicle screw fixation is a well-established technique for the lumbar spine, screw placement in the thoracic spine is more challenging because of the smaller pedicle size and more complex 3D anatomy. The intraoperative use of image guidance devices may allow surgeons a safer, more accurate method for placing thoracic pedicle screws while limiting radiation exposure. This generic 3D imaging technique is a new generation intraoperative CT imaging system designed without compromise to address the needs of a modern OR.

Aim

The aim of our study was to check the accuracy of this generic 3D navigated pedicle screw implants in comparison to free hand technique described by Roy-Camille at the thoracic spine using CT scans.

Material and methods

The material of this study was divided into two groups: free hand group (group I) (18 patients; 108 screws) and 3D group (27 patients; 100 screws). The patients were operated upon from January 2009 to March 2010. Screw implantation was performed during internal fixation for fractures, tumors, and spondylodiscitis of the thoracic spine as well as for degenerative lumbar scoliosis.

Results

The accuracy rate in our work was 89.8 % in the free hand group compared to 98 % in the generic 3D navigated group.

Conclusion

In conclusion, 3D navigation-assisted pedicle screw placement is superior to free hand technique in the thoracic spine.     

Heterogeneous spine loss in layer 5 cortical neurons after spinal cord injury

A large thoracic spinal cord injury disconnects the hindlimb (HL) sensory-motor cortex from its target, the lumbar spinal cord. The fate of the synaptic structures of the axotomized cortical neurons is not well studied. We evaluated the density of spines on axotomized corticospinal neurons at 3, 7, and 21 days after the injury in adult mice expressing yellow fluorescence protein in a subset of layer 5 neurons. Spine density of the dendritic segment proximal to the soma (in layer 5) declined as early as 3 days after injury, far preceding the onset of somatic atrophy. In the distal segment (in layer 2/3), spine loss was slower and less severe than in the proximal segment. Axotomy of corticospinal axons in the brainstem (pyramidotomy) induced a comparable reduction of spine density, demonstrating that the loss is not restricted to the neurons axotomized in the thoracic spinal cord. Surprisingly, in both forms of injury, the spine density of putative non-axotomized layer 5 neurons was reduced as well. The spine loss may reflect fast rearrangements of cortical circuits after axotomy, for example, by a disconnection of HL cortical neurons from synaptic inputs that no longer provide useful information.     

Ability of a novel system for neonatal extracorporeal renal replacement therapy with an ultra-small volume circuit to remove solutes <Emphasis Type="Italic">in vitro</Emphasis>

Background

We automated our manual, syringe-driven extracorporeal renal replacement therapy (eRRT) system with an ultra-small volume circuit (3.2 ml) that is suitable for neonates without blood priming. Our objective was to determine the solute clearance and water balance of the automated and manual systems in vitro.

Methods

Stored whole blood samples containing exogenous urea, creatinine (Cr), potassium (K), and ammonia (NH₃) to imitate acute kidney injury (AKI) and hyperammonemia were dialyzed for 3 h (blood flow, 4.0 ml/min; dialysate flow, 600 ml/h) with a continuous infusion of heparin. Solute clearance and sample weight were then compared with values before dialysis.

Results

The median clearance of blood urea nitrogen, Cr, K, and NH₃ ranged from 1.7 to 2.3 and from 2.4 to 2.6 ml/min, and the median weight of the samples was decreased by 3.8 g and increased by 8.3 g after 3 h of dialysis using the manual and automated systems, respectively.

Conclusions

The automated system effectively cleared solutes, but safety concerns were associated with platelet consumption and fluid balance. Additional studies are needed to establish the safety and accuracy of this novel system for clinical use in neonates and preterm infants.

     

Three-dimensional morphology study of surgical adolescent idiopathic scoliosis patient from encoded geometric models

Purpose

The classification of three-dimensional (3D) spinal deformities remains an open question in adolescent idiopathic scoliosis. Recent studies have investigated pattern classification based on explicit clinical parameters. An emerging trend however seeks to simplify complex spine geometries and capture the predominant modes of variability of the deformation. The objective of this study is to perform a 3D characterization and morphology analysis of the thoracic and thoraco/lumbar scoliotic spines (cross-sectional study). The presence of subgroups within all Lenke types will be investigated by analyzing a simplified representation of the geometric 3D reconstruction of a patient’s spine, and to establish the basis for a new classification approach based on a machine learning algorithm.

Methods

Three-dimensional reconstructions of coronal and sagittal standing radiographs of 663 patients, for a total of 915 visits, covering all types of deformities in adolescent idiopathic scoliosis (single, double and triple curves) and reviewed by the 3D Classification Committee of the Scoliosis Research Society, were analyzed using a machine learning algorithm based on stacked auto-encoders. The codes produced for each 3D reconstruction would be then grouped together using an unsupervised clustering method. For each identified cluster, Cobb angle and orientation of the plane of maximum curvature in the thoracic and lumbar curves, axial rotation of the apical vertebrae, kyphosis (T4–T12), lordosis (L1–S1) and pelvic incidence were obtained. No assumptions were made regarding grouping tendencies in the data nor were the number of clusters predefined.

Results

Eleven groups were revealed from the 915 visits, wherein the location of the main curve, kyphosis and lordosis were the three major discriminating factors with slight overlap between groups. Two main groups emerge among the eleven different clusters of patients: a first with small thoracic deformities and large lumbar deformities, while the other with large thoracic deformities and small lumbar curvature. The main factor that allowed identifying eleven distinct subgroups within the surgical patients (major curves) from Lenke type-1 to type-6 curves, was the location of the apical vertebra as identified by the planes of maximum curvature obtained in both thoracic and thoraco/lumbar segments. Both hypokyphotic and hyperkypothic clusters were primarily composed of Lenke 1–4 curve type patients, while a hyperlordotic cluster was composed of Lenke 5 and 6 curve type patients.

Conclusion

The stacked auto-encoder analysis technique helped to simplify the complex nature of 3D spine models, while preserving the intrinsic properties that are typically measured with explicit parameters derived from the 3D reconstruction.

     

Comparison of lumbar spine fusion using mixed and cloned marrow cells.

STUDY DESIGN: Prospective study on lumbar spine fusion using cloned and mixed marrow cells. OBJECTIVE: To analyze the effectiveness of cloned osteoprogenitor cells in spine fusion and their differentiation in vivo using a traceable gene. SUMMARY OF BACKGROUND DATA: Although autografts are currently the standard for stable spine fusion, supply is limited. Alternative graft materials need to be developed and evaluated. METHODS: An osteoprogenitor cell, D1-BAG, cloned from mouse bone marrow and transduced with LacZ and neomycin resistance genes, and mixed marrow stromal cells from marrow blowouts were used in athymic rats to establish posterior spinal fusion; 2 x 10(6) cells in 100 microL Matrigel were implanted into the lumbar fusion bed in 36 animals, whereas Matrigel without cells was used in 16 animals as control. Rats were killed at 2, 3, 6, and 9 weeks, and the spines were evaluated by manual palpation, radiographs, and histology. RESULTS: Two weeks after surgery radiopaque tissue was seen at transplantation sites with D1-BAG cells but not at sites with mixed marrow stromal cells. Successful spine fusion at 6 and 9 weeks was observed in 8 of 8 (100%) animals receiving DI-BAG cells, 4 of 8 (50%) in mixed marrow stromal cells, and 0 of 8 (0%) in control animals. CONCLUSIONS: Compared with mixed marrow stromal cells, cloned osteoprogenitor cells can produce a larger amount of mature osseous tissue at an earlier time point during spine fusion.     

Automation of human semen analysis using a novel artificial intelligence optical microscopic technology

Current semen analysis still commonly depends on a manual microscopy method in clinical laboratories worldwide. However, some of the major disadvantages of this technique are that it is labour‐intensive, subjective, laboratory‐based and time‐consuming. Although computer‐assisted semen analysers (CASAs) have enabled partial automation of routine semen analysis, they lack wider acceptance due to their complicated operation. Therefore, the development of an accessible, rapid and standardised method for semen analysis is urgently needed. Here, we describe the development and clinical testing of a novel, automated, artificial intelligence optical microscopic (AIOM)‐based technology, LensHooke? X1 PRO (X1 PRO), designed for the quantitative measurement of sperm concentration, motility and seminal pH. We observed high degree of correlation in the results of concentration, progressive motility and progressively motile sperm concentration between the X1 PRO semen analyser and manual method using 135 clinical semen samples. In addition, the seminal pH results obtained by X1 PRO and manual methods were comparable (p = .12). In summary, our results showed that new X1 PRO semen analyser is a reliable diagnostic tool for routine semen analysis providing clinically acceptable results based on World Health Organization (WHO) 5th Edition guidelines.     

Repeated stress induces dendritic spine loss in the rat medial prefrontal cortex

The prefrontal cortex (PFC) plays an important role in higher cognitive processes, and in the regulation of stress-induced hypothalamic-pituitary-adrenal (HPA) activity. Here we examined the effect of repeated restraint stress on dendritic spine number in the medial PFC. Rats were perfused after receiving 21 days of daily restraint stress, and intracellular iontophoretic injections of Lucifer Yellow were carried out in layer II/III pyramidal neurons in the anterior cingulate and prelimbic cortices. We found that stress results in a significant (16%) decrease in apical dendritic spine density in medial PFC pyramidal neurons, and confirmed a previous observation that total apical dendritic length is reduced by 20% in the same neurons. We estimate that nearly one-third of all axospinous synapses on apical dendrites of pyramidal neurons in medial PFC are lost following repeated stress. A decrease in medial PFC dendritic spines may not only be indicative of a decrease in the total population of axospinous synapses, but may impair these neurons' capacity for biochemical compartmentalization and plasticity in which dendritic spines play a major role. Dendritic atrophy and spine loss may be important cellular features of stress-related psychiatric disorders where the PFC is functionally impaired.     

Accuracy and reliability of coronal and sagittal spinal curvature data based on patient-specific three-dimensional models created by the EOS 2D/3D imaging system

Background context

Three-dimensional (3D) deformations of the spine are predominantly characterized by two-dimensional (2D) angulation measurements in coronal and sagittal planes, using anteroposterior and lateral X-ray images. For coronal curves, a method originally described by Cobb and for sagittal curves a modified Cobb method are most widely used in practice, and these methods have been shown to exhibit good-to-excellent reliability and reproducibility, carried out either manually or by computer-based tools. Recently, an ultralow radiation dose–integrated radioimaging solution was introduced with special software for realistic 3D visualization and parametric characterization of the spinal column.

Purpose

Comparison of accuracy, correlation of measurement values, intraobserver and interrater reliability of methods by conventional manual 2D and sterEOS 3D measurements in a routine clinical setting.

Study design/setting

Retrospective nonrandomized study of diagnostic X-ray images created as part of a routine clinical protocol of eligible patients examined at our clinic during a 30-month period between July 2007 and December 2009.

Patient sample

In total, 201 individuals (170 females, 31 males; mean age, 19.88 years) including 10 healthy athletes with normal spine and patients with adolescent idiopathic scoliosis (175 cases), adult degenerative scoliosis (11 cases), and Scheuermann hyperkyphosis (5 cases). Overall range of coronal curves was between 2.4° and 117.5°. Analysis of accuracy and reliability of measurements were carried out on a group of all patients and in subgroups based on coronal plane deviation: 0° to 10° (Group 1, n=36), 10° to 25° (Group 2, n=25), 25° to 50° (Group 3, n=69), 50° to 75° (Group 4, n=49), and more than 75° (Group 5, n=22).

Methods

Coronal and sagittal curvature measurements were determined by three experienced examiners, using either traditional 2D methods or automatic measurements based on sterEOS 3D reconstructions. Manual measurements were performed three times, and sterEOS 3D reconstructions and automatic measurements were performed two times by each examiner. Means comparison t test, Pearson bivariate correlation analysis, reliability analysis by intraclass correlation coefficients for intraobserver reproducibility and interrater reliability were performed using SPSS v16.0 software (IBM Corp., Armonk, NY, USA). No funds were received in support of this work. No benefits in any form have been or will be received from a commercial party related directly or indirectly to the subject of this article.

Results

In comparison with manual 2D methods, only small and nonsignificant differences were detectable in sterEOS 3D–based curvature data. Intraobserver reliability was excellent for both methods, and interrater reproducibility was consistently higher for sterEOS 3D methods that was found to be unaffected by the magnitude of coronal curves or sagittal plane deviations.

Conclusions

This is the first clinical report on EOS 2D/3D system (EOS Imaging, Paris, France) and its sterEOS 3D software, documenting an excellent capability for accurate, reliable, and reproducible spinal curvature measurements.