Number Of Cortices Research Articles

Türkiye’den Noccaea Moench (Brassicaceae) Cinsi Anatomisi Üzerine Katkılar

The anatomical properties of Noccaea camlikensis and N. cariensis were determined in this study. The roots have a secondary root type. The stem cross-sections have a single-layered epidermis, parenchymatous cortex, one layered distinct endodermis, vascular bundles with sclerenchymatic caps, and parenchymatic pith cells. Equifacial and bifacial mesophyll types are observed in the leaves, with multiple-layered palisade tissue, and the spongy parenchyma is well-developed. Vascular bundles are small in the leaves except in the leaf midrib. Anisocytic stomata type are observed in the surface sections. The assessment of anatomical characteristics of the studied Noccaea species, such as the number of cortex in the stem and the shape of midvein of leaf, are of taxonomical value.

Does Surgical Placement of Syndesmosis Screws Affect Breakage Rate? A Retrospective Comparative Study

Category:AnkleIntroduction/Purpose:Fixation of syndesmosis disruption with metal screws remains a frequent and efficacious treatment modality. Screw breakage remains a complication seen in many patients following metal fixation. Overtime physiologic rotation or the tibia and fibula can lead to bone erosion and pain in patients with screw breakage. The purpose of this study is to compare patients with syndesmosis screw breakage and patients with intact screws based surgically controlled variables.Methods:A retrospective analysis of patients who underwent syndesmotic screw fixation from 2008 - 2020 was performed. Ninety-seven patients were found to have syndesmosis screw breakage, of which 88 met inclusion criteria. A control group of patients without syndesmosis screw breakage was selected at random and analyzed until 88 patients met inclusion criteria. The number of screws used, width, length, fracture type and number of cortices were all collected. Further analysis included radiographic measurement syndesmosis screw angle and height of placement above the tibial plafond. A regression analysis was performed to compare to the two groups, including a separate analysis comparing unbroken screws within syndesmosis screw breakage cohort versus their broken screws, as this provided an absolute control group. A stratified analysis of screw placement and angle was also performed based on standard deviation.Results:The average screw width in the breakage group was 3.67 (SD =.38) and 4.06 (SD =0.04) in the intact group (P =<.001). Average screw angle was 94.82 (SD = 12.75) in the breakage group and 94.67 (SD 12.31) in the intact group (based on 90 degrees relative to tibial plafond). Screw placement of the tibial plafond was 20.39 (SD =10.389) in the breakage group and 16. 75 (SD = 9.28) in the intact group. 70.3% of broken screws were placed > 20mm above the tibial plafond, compared to 64.0% in the control group. Most screws were placed at angle > 82 degrees relative to the tibial plafond; 76% (n =92) of broken screws and 81.2% (n=211) of intact screws). Decreased screw width (P =<.001) and screw placement > 20mm above the tibial plafond (P =<.001) were all associated with an increased risk of screw breakage.Conclusion:Metal screw fixation remains an efficacious treatment method of syndesmotic disruption. Despite extensive research the cause of syndesmosis screw breakage and the necessity of screw removal remains without consensus. The is study aims to analyze surgical variables in attempt to find correlation with screw breakage. An increased BMI was seen to predispose to screw breakage. Placement of the syndesmosis screw <20 mm above the tibial plafond and increased screw width provide protection against syndesmosis breakage. No significant differences were found between groups based on screw angle, number of cortices, screw length, or number of screws used.

The anatomical, palynological and micromorphological aspects of three endemic Bellevalia species (Asparagaceae) in Turkey and their taxonomic importance

In the present research, anatomical, palynological and micromorphological characteristics of three endemic Bellevalia species (B. gracilis, B. malatyaensis and B. vuralii) for Turkey are carried out. This work reveals the descriptive characteristics of the examined species, and contribute to solving taxonomic problems. Anatomical studies were carried out on cross sections of root, scape and leaf. The metaxylem, the number of root cortex cells, and the number of cortex and sclerenchyma cells in the scape were found to be significant in terms of taxonomy. Pollen grains of all the examined species were monosulcate and heteropolar. In addition, seed and pollen surface ornamentation were photographed under SEM microscopy, which SEM micrographs showed that the exine sculpturing pattern is reticulate-perforate, and pollen muri walls of were different among the examined species. Conversely, seeds showed a general similarity of the surface among the studied species, all showing a reticulate faveolate ornamentation.

Biomechanical evaluation of syndesmotic fixation techniques via finite element analysis: Screw vs. suture button

Background and ObjectiveTibiofibular syndesmotic injuries may cause degenerative changes, reduction in ankle function and compromising ankle stability. Different fixation techniques try to restore its functionality. Screw-fixation is the gold-standard. Recently, suture-button fixation has aroused the attention because it allows for physiologic micromotion while maintaining an accurate reduction. The aim of this study is to compare the biomechanical behaviour of both fixation techniques using the finite element method. MethodsA three-dimensional finite element model of the tibiofibular joint was reconstructed simulating the intact ankle and the injured syndesmosis. Then, different methods of syndesmosis fixation were analysed: screws (number of cortices, number of screws and distance between screws) and suture buttons (single, double parallel and double divergent with a sensitivity analysis on the pretension forces) configuration. Ligaments and cartilages were included and simulated as spring elements. Physiological loads during stance phase were simulated. ResultsSyndesmosis widening and von Mises stresses were computed. Syndesmosis widening in the injured configuration compromised joint stability (2.06 mm), whereas using a single quadricortical screw (0.18 mm) stiffened the joint. Syndesmosis widening using suture-buttons were closer to syndesmosis widening of the intact ankle configuration (0.97 mm). Von Mises stresses were higher for the titanium screws than for the suture buttons. ConclusionsA detailed biomechanical comparison among different syndesmotic fixation was performed. Suture buttons have advantages with regard to syndesmosis widening in comparison to screw fixation. This fact supports the good long-term clinical results obtained with suture buttons fixation. The proposed methodology could be an efficient tool for preoperative planning.

Removal of Syndesmotic Screw After Fixation in Ankle Fractures: A Systematic Review.

Syndesmotic injuries can occur with ankle fractures and can lead to destabilization of the ankle joint. As a result, it usually requires a transyndesmotic screw insertion to stabilize it. Currently, there is no consensus on the type, amount and diameter of screws used, the number of cortices needed to be engaged, the recommended time to weight-bearing, and whether the screw should be removed in these types of injuries. The aim of this study is to evaluate the evidence comparing the removal and non-removal of syndesmotic screws in open and closed ankle fractures that are associated with unstable syndesmosis in terms of functional, clinical, and radiological evidence. The study also looked at the evidence behind broken screw effects.The literature search was conducted on March 16, 2021, using the Ovid Medline and Embase databases. The literature was eligible if it aimed to compare syndesmotic screw removal and retention in ankle fractures. One study found that those with a broken screw had a better clinical outcome than those with an intact screw. The studies were excluded if they were biomechanical studies, case reports, or were relevant but had no adequate English translation.Initially, 53 studies were included but after scanning for eligibility, 11 were identified (including those added from references). Nine were cohort studies, seven of which did not find any difference in functional outcome between routine removal and retention of the syndesmotic screw. Two studies found there were better clinical outcomes in the broken screw group. Another study found that there were slightly worse functional outcomes in patients with intact screws as compared with those with broken, loosened, or removed screws. Two studies were randomized control studies that no significant functional outcomes between removed and intact syndesmotic screws. However, the majority of these studies had a high risk of bias.Overall, the current literature provides no evidence to support routine removal of syndesmotic screws. Keeping in mind the clear complications and financial burden, syndesmotic screw removal should not be performed unless there is a clear indication. Furthermore, removal in the clinic, with the use of prophylactic antibiotics should be considered if indicated in cases with pain or loss of function. Further research in a structured randomized controlled trial (RCT) to examine if there is any difference in short- or long-term outcomes between removed, intact, loose, or broken syndesmotic screws might be beneficial. A multinational protocol for randomized control trials (RODEO-trial) is an example of such a study to determine the usefulness of on-demand and routine removal of screws.

Syndesmosis Screw Breakage: An Analysis of Current Literature

Category:Ankle; TraumaIntroduction/Purpose:Syndesmosis screw fracture is a common occurrence post syndesmosis screw fixation. The purpose of this study is to analyze all studies that include syndesmosis injury fixed with syndesmosis screws based on patient, screw, and surgical/rehabilitation characteristics. An emphasis will be placed on patients who suffered syndesmosis screw fracture following fixation. To date, no review has examined patient, screw, and surgical/rehabilitation characteristics with an emphasis on screw fractures in this patient population.Methods:Of the 482 articles assessed for eligibility, a total 52 articles were selected for full-text review. Following further inclusion criteria requirement 21 articles were included in the study. Each study was analyzed based on patient, screw, and surgical/rehabilitation characteristics. Patient demographics and comorbidities of gender, age, BMI, smoking, alcohol abuse, diabetes, soft tissue conditions were included. Screw characteristics that were included were screw material, number of screws, screw width, number of cortices, and number of patients with screw fracture (screw fracture rate). Surgical/rehabilitation characteristics included ankle position, screw placement above tibial plafond, screw angle, routine removal, rehabilitation process, and time to full weight bearing.Results:A total of 1,196 patients, 761 men and 440 females, were included in the analysis. The average number of patients in each study was 59.80±39.41(12-161). Comprehensive screw, surgical, and rehabilitation + outcome data can be seen in Table 1, 2, and 3, respectively. Nine studies reported on ankle position during surgery; dorsiflexion was the most common. Fourteen reported on placement of the screw above the tibial plafond, with 2 cm being the most common. Five reported on screw angle. 141 patients had a fractured screw(s). The average fracture rate was 11.41%. Five of the 21 studies reported BMI. Three studies stratified data comparing broken screw versus intact screw patients. Five reported on diabetes, one on alcohol abuse, and one study reported on comorbidities.Conclusion:In conclusion, analysis of syndesmosis screw fracture patients versus those with no fracture was difficult due to lack of differentiation in almost all the studies. Notably, syndesmosis screw fracture studies under report patient characteristics, specifically BMI. Comorbidities, especially BMI, are potential cofounding variables within this patient population and could contribute to screw failure. Future studies should include both BMI and comorbidities when analyzing patients whose syndesmosis fixation resulted in screw breakage.

Operative Treatment of Syndesmotic Injuries With Assisted Arthroscopic Reduction

There continues to be a lack of consensus on the proper treatment of syndesmotic injuries in the literature. Currently, much of the operative debate lies between using a suture-button technique or transsyndesmotic screw fixation to treat the injury. There are further arguments surrounding screw fixation involving the size and number of the screws, the number of cortices, and whether or not the hardware is to be removed. For patients presenting with a syndesmotic injury, it is important to properly diagnose and address the type of injury in order to prevent long-term morbidity and ultimately, degenerative arthritis. In the case of unstable syndesmotic injuries, we advocate the use of screw fixation, using 2, fully threaded, 4.0-mm cortical screws through 4 cortices and removal of the hardware 3 months postoperatively. Level of Evidence: Level IV.

Microglial Activation After Systemic Stimulation With Lipopolysaccharide and Escherichia coli.

Background: Microglial activation after systemic infection has been suggested to mediate sepsis-associated delirium. A systematic review of animal studies suggested distinct differences between microglial activation after systemic challenge with live bacteria and lipopolysaccharide (LPS). Here, we describe a mouse model of microglial activation after systemic challenge with live Escherichia coli (E. coli) and compare results with systemic challenge with LPS.Methods: Sixty mice were intraperitoneally injected with E. coli (1 × 104 colony-forming units) and sacrificed at 12, 20, 48, and 72 h after inoculation. For 48 and 72 h time points, mice were treated with ceftriaxone. Thirty mice were intraperitoneally injected with LPS (5 mg/kg) and sacrificed 3 and 48 h after inoculation; 48 control mice were intraperitoneally injected with isotonic saline. Microglial response was monitored by immunohistochemical staining with Iba-1 antibody and flow cytometry; and inflammatory response by mRNA expression of pro- and anti-inflammatory mediators.Results: Mice infected with live E. coli showed microglial activation 72 h post-inoculation, with increased cell number in cortex (p = 0.0002), hippocampus (p = 0.003), and thalamus (p = 0.0001), but not in the caudate nucleus/putamen (p = 0.33), as compared to controls. At 72 h, flow cytometry of microglia from E. coli infected mice showed increased cell size (p = 0.03) and CD45 expression (p = 0.03), but no increase in CD11b expression, and no differences in brain mRNA expression of inflammatory mediators as compared to controls. In mice with systemic LPS stimulation, microglial cells were morphologically activated at the 48 h time point with increased cell numbers in cortex (p = 0.002), hippocampus (p = 0.0003), thalamus (p = 0.007), and caudate nucleus/putamen (p < 0.0001), as compared to controls. At 48 h, flow cytometry of microglia from LPS stimulated mice showed increased cell size (p = 0.03), CD45 (p = 0.03), and CD11b (p = 0.04) expression. Brain mRNA expression of TNF-α (p = 0.02), IL-1β (p = 0.02), and MCP-1 (p = 0.03) were increased as compared to controls.Interpretation: Systemic challenge with live E. coli causes a neuro-inflammatory response, but this response occurs at a later time point and is less vigorous as compared to LPS stimulation.The E. coli model mimics the clinical situation of infection associated delirium more closely than stimulation with supra-natural LPS.

Refined protocols of tamoxifen injection for inducible DNA recombination in mouse astroglia

Inducible DNA recombination of floxed alleles in vivo by liver metabolites of tamoxifen (TAM) is an important tool to study gene functions. Here, we describe protocols for optimal DNA recombination in astrocytes, based on the GLAST-CreERT2/loxP system. In addition, we demonstrate that quantification of genomic recombination allows to determine the proportion of cell types in various brain regions. We analyzed the presence and clearance of TAM and its metabolites (N-desmethyl-tamoxifen, 4-hydroxytamoxifen and endoxifen) in brain and serum of mice by liquid chromatographic-high resolution-tandem mass spectrometry (LC-HR-MS/MS) and assessed optimal injection protocols by quantitative RT-PCR of several floxed target genes (p2ry1, gria1, gabbr1 and Rosa26-tdTomato locus). Maximal recombination could be achieved in cortex and cerebellum by single daily injections for five and three consecutive days, respectively. Furthermore, quantifying the loss of floxed alleles predicted the percentage of GLAST-positive cells (astroglia) per brain region. We found that astrocytes contributed 20 to 30% of the total cell number in cortex, hippocampus, brainstem and optic nerve, while in the cerebellum Bergmann glia, velate astrocytes and white matter astrocytes accounted only for 8% of all cells.

Age exacerbates abnormal protein expression in a mouse model of Down syndrome

The Ts65Dn is a popular mouse model of Down syndrome (DS). It displays DS-relevant features of learning/memory deficits and age-related loss of functional markers in basal forebrain cholinergic neurons. Here we describe protein expression abnormalities in brain regions of 12-month-old male Ts65Dn mice. We show that the magnitudes of abnormalities of human chromosome 21 and non–human chromosome 21 orthologous proteins are greater at 12 months than at ∼6 months. Age-related exacerbations involve the number of components affected in the mechanistic target of rapamycin pathway, the levels of components of the mitogen-activated protein kinase pathway, and proteins associated with Alzheimer's disease. Among brain regions, the number of abnormalities in cerebellum decreased while the number in cortex greatly increased with age. The Ts65Dn is being used in preclinical evaluations of drugs for cognition in DS. Most commonly, drug evaluations are tested in ∼4- to 6-month-old mice. Data on age-related changes in magnitude and specificity of protein perturbations can be used to understand the molecular basis of changes in cognitive ability and to predict potential age-related specificities in drug efficacies.

Economic impact of syndesmosis hardware removal

Ankle syndesmosis injuries are commonly seen with 5–10% of sprains and 10% of ankle fractures involving injury to the ankle syndesmosis. Anatomic reduction has been shown to be the most important predictor of clinical outcomes. Optimal surgical management has been a subject of debate in the literature. The method of fixation, number of screws, screw size, and number of cortices are all controversial. Postoperative hardware removal has also been widely debated in the literature. Some surgeons advocate for elective hardware removal prior to resuming full weightbearing. Returning to the operating room for elective hardware removal results in increased cost to the patient, potential for infection or complication(s), and missed work days for the patient. Suture button devices and bioabsorbable screw fixation present other options, but cortical screw fixation remains the gold standard. This retrospective review was designed to evaluate the economic impact of a second operative procedure for elective removal of 3.5mm cortical syndesmosis screws. Two hundred and two patients with ICD-9 code for “open treatment of distal tibiofibular joint (syndesmosis) disruption” were identified. The medical records were reviewed for those who underwent elective syndesmosis hardware removal. The primary outcome measurements included total hospital billing charges and total hospital billing collection. Secondary outcome measurements included average individual patient operative costs and average operating room time. Fifty-six patients were included in the study. Our institution billed a total of $188,271 (USD) and collected $106,284 (55%). The average individual patient operating room cost was $3579. The average operating room time was 67.9min. To the best of our knowledge, no study has previously provided cost associated with syndesmosis hardware removal. Our study shows elective syndesmosis hardware removal places substantial economic burden on both the patient and the healthcare system.

Morphological, anatomical, palynological, and micromorphological characters of 2 endemic species of Ornithogalum (O. chetikianum and O. demirizianum) in Turkey

In this investigation, the comparative morphological, anatomical, palynological, and micromorphological characters of Ornithogalum chetikianum Uysal, Ertuğrul & Dural and O. demirizianum Malyer & Koyuncu, which belong to Ornithogalum subgenus Myogalum (=Honorius) (Asparagaceae), are presented. In accordance with the new observations, dimensions of some morphological characters are revised as distinct from the previous description of the species. Anatomical investigations of roots, scapes, and leaves were found to be useful for taxonomy. Some anatomical characters, such as the number of protoxylem arms in the root, the number of cortex and sclerenchyma layers in the scape, and type of mesophyll cells in the leaf, provide information of taxonomical significance. Pollen grains of O. chetikianum are monosulcate, but the pollen grains of O. demirizianum are both monosulcate and zonosulcate (10%). As a result of this study, some pollen characteristics such as aperture type, pollen shape, and exine ornamentation were demonstrated to be different between the species. Capsules and seeds of the species are different from one another, especially in their shapes. The investigated species are compared with the other studied species in the subgenus Myogalum.

Biomechanical Evaluation of Anterior Thoracic Salvage Screws in the Osteoporotic Thoracic Spine

Controlled, cadaveric implantation trial. Evaluation of revision thoracic screw fixation: with revision from unicortical screws to bicortical screws, to larger diameter screws, and the addition of bone cement. Limited data is available regarding the effect of salvage screws on fixation quality in the anterior thoracic spine. Biomechanical studies in the cervical spine and the lumbar spine demonstrate dramatic decreases in fixation in salvage situations. Seventy-two cadaveric thoracic vertebrae from 6 specimens were DEXA scanned at T1-T12. A control screw and a second identical screw were placed in each segment. One screw was then removed and replaced with a revision screw. Varying screw diameter, the number of cortices, and the addition of 1.5 cm of bone cement was evaluated in a pairwise fashion. Comparisons were made using descriptive statistical analysis and a general linear statistical model. Bone mineral density had a significant effect on the pullout force. Pullout force did not vary significantly with control screw diameter. Revision of a smaller diameter bicortical to a larger diameter bicortical screw resulted in a decrease in pullout strength for 4-5 mm screws by 40.1% (P=0.02) and 5-7 mm screws by 63.7% (P=0.05). When a 4 mm bicortical screw is revised to a 5 mm unicortical screw, the pullout force decreases by 67.7% (P<0.001). There was a nonsignificant increase (44%) in pullout with revision of a unicortical 4 mm screw to a bicortical 4 mm screw. If a bicortical screw is revised to a unicortical screw with 1.5 cm of cement, the pullout strength is increased by 240% (P<0.001). When the use of salvage screws is required, the surgeon should anticipate a significant decrease in the holding force compared with the original screw regardless of screw size unless a unicortical screw is revised to a bicortical screw or cement is added to the construct.

The Effect of Obesity on Early Failure After Operative Syndesmosis Injuries

The goal of this investigation was to determine if obese patients with syndesmotic injuries have a higher incidence of early postoperative failure compared with nonobese patients. Retrospective cohort study. Level 1 urban trauma center. Two hundred thirteen patients with operative syndesmotic injuries were divided into 2 cohorts: obese and nonobese. All syndesmotic injuries were confirmed by intraoperative stress testing, reduced, and stabilized with internal fixation. Fixation of displaced syndesmosis injuries with solid 3.5- and 4.5-mm screws. The primary outcome was early failure of fixation, defined as revision surgery within 3 months for ankle mortise and/or syndesmosis displacement. Two hundred thirteen patients were identified with operative syndesmosis injuries, of which 102 (48%) were obese and 111 (52%) were nonobese. Fifteen percent (n = 15) of patients in the obese cohort sustained a failure of fixation compared with 1.8% (n = 2) of patients in the nonobese cohort (P = 0.0005). Diabetes mellitus, smoking status, and the type of construct used (eg, screw caliber, number of screws, and number of cortices) were not predictive of loss of reduction. Adjusting for injury severity, obese patients were 12 times more likely to suffer a loss of reduction compared with nonobese patients (odds ratio = 12.0, P = 0.02). There is a strong association between obesity and loss of reduction after operative treatment of the syndesmosis. Further research is warranted to determine if a stronger mechanical construct or more conservative postoperative protocol can reduce the risk of loss of reduction in obese patients who sustain a syndesmotic injury.

Common Pitfalls in Syndesmotic Rupture Management

Syndesmotic injuries occur in up to 11% of all ankle injuries. Whereas the optimal fixation of syndesmotic injuries remains controversial, pitfalls in their management can lead to poor outcomes. This is a retrospective study of all ankle fractures operated on at a level 1 trauma center over a 7-year period. All cases with syndesmotic fixation were classified and patients' notes and x-rays were reviewed. The timing of definitive syndesmotic fixation, the type of fixation (screw size and number, number of cortices), and the number of unplanned, syndesmotic-related reoperations were recorded. Seventy syndesmotic ruptures were operated on during the study period. There were 19 unplanned reoperations. The 3 reasons for reoperation identified were failure to diagnose the syndesmotic injury 9/19 (47%), failure to achieve an anatomic reduction 6/19 (31%), and loss of reduction due to fixation failure 4/19 (21%). The type of fixation was not correlated with the failure rate, nor were the experience of the surgeon, the gender or the age of the patient. The reoperation rate for syndesmotic fixation may be higher than previously thought. In order to reduce the pitfalls in their treatment, we emphazise the importance of 3 critical points in the management of these injuries: suspect the injury, document the stability of the syndesmosis, and reduce the fibula anatomically. Level III, retrospective comparative series.

Maternal immune activation increases neonatal mouse cortex thickness and cell density.

Autism is a debilitating neuropsychiatric disorder affecting children and young adults during the most vulnerable points in psychological and social development. With an estimated incidence of one in 88 births, autism spectrum disorder is characterized by impaired social interaction and communication, and restricted interests and stereotyped behaviors that occur before the age of three. Epidemiologic studies have suggested a role for environmental factors in the development of both autism and schizophrenia (Patterson 2009). A well-documented environmental risk factor for developing these neuropsychiatric diseases is maternal infection during pregnancy. Multiple studies have correlated a high prevalence of influenza infection with a high rate of schizophrenic births several months afterwards (Brown 2011; Mednick et al. 1988). The most direct evidence of this relationship comes from prospective studies involving banked serum from women who were pregnant in the 1960s, and follow-up work examined their offspring over 20 years later. Among mothers with serologically-verified influenza infection, schizophrenia risk was increased 3–7 fold in the offspring (Brown and Susser 2002). Similar evidence links other maternal infections, such as rubella, toxoplasma, and genital/reproductive infections, with subsequent schizophrenia in the offspring (Babulas et al. 2006; Brown et al. 2005). A correlation between autism and maternal viral infection was recently established by a large study of the Danish medical records (Atladottir et al. 2010). Autism risk is reportedly increased almost 200-fold with a maternal rubella infection (Chess 1977). Maternal infections including toxoplasmosis, syphilis, varicella, and rubeola during pregnancy are associated with autism in small case studies, summarized in Ciaranello and Ciaranello (1995). These findings suggest a potential role for infection during pregnancy in the etiology of at least some cases of autism. In studies aimed at modeling a viral infection during pregnancy in mice, a non-infectious Toll-like receptor 3 (TLR3) agonist, polyI:C has been injected into the mother during pregnancy and importantly this intervention altered the behavior of the adult offspring in a manner resembling autism (Patterson 2009). The mice show decreased social interaction, abnormal vocalizations, increased anxiety, and poor performance on latent inhibition and prepulse inhibition tests. Concurrent with these behavioral changes, some histologic changes reminiscent of the human disease have been documented such as fewer Purkinje cells in the cerebellum as seen in autism (Shi et al. 2009) and reduced cortical parvalbumin reactivity as seen in schizophrenia (Meyer et al. 2008). The mechanism by which maternal immune activation causes the behavioral changes has also been investigated and implicates the cytokines, particularly interleukin-6, which are produced at the site of immune stimulation but then travel throughout the maternal circulation to interfere with fetal development (Hsiao and Patterson 2011; Smith et al. 2007). Importantly, the abnormal levels of pro-inflammatory cytokines and growth factors present in the maternal immune-exposed fetal brains could potentially alter proliferation or migration of the neural progenitor cells destined to form the cerebral cortex. Studies of the human autism brain are also consistent with the notion that autism might arise from an activation of the immune system to trigger abnormal brain development. Analyses of postmortem brain tissue and CSF from individuals with autism have established that cytokines, chemokines, and growth factors are increased (Vargas et al. 2005). Similarly, transcripts for immunity-related genes are elevated in autism postmortem brain tissues (Voineagu et al. 2011). In addition to the increase of cyto-kines, chemokines, and growth factors, individuals with autism are reported to display an increased head circumference, brain volume, and neuron number in cortex at the onset of symptoms in early childhood (Schumann and Nordahl 2010; Courchesne et al. 2011). Potentially also related to the excess of cortical neurons, minicolumns, a vertically oriented cluster of neurons spanning the cortical layers within the cerebral cortex, are more numerous and display a greater dispersion due to a decreased alignment of pyramidal cells along the core axis (Casanova and Trippe 2009). In aggregate, these studies support a model where maternal immune activity during pregnancy might promote an increase of cytokine, chemokines, and growth factors that promotes the generation of an excess number of cortical neurons in-utero. We directly test the hypothesis that maternal immune activation during pregnancy is sufficient to trigger an expansion of the cortical neuron population by measuring cortical thickness and cell density in the neonatal cortex at postnatal day 0 (P0) following in utero maternal intraperi-toneal polyI:C injections.

Leg lengthening by distraction osteogenesis using the Ilizarov apparatus: a novel concept of tibia callus subsidence and its influencing factors

This article studies the incidence and magnitude of delayed callus subsidence, which will also help in study the hypothesis of three cortex corticalisation to determine the time of fixator removal during distraction osteogenesis (DO). Eighty-one tibia segments with mean lengthening of 7.7 +/- 2.9 cm were studied with age, gender, skeletal maturity, amount and percentage of lengthening, callus pattern, callus shape, number of cortices seen at the time of fixator removal, bone mineral density (BMD) ratio, and callus diameter ratio analysed for their effect on callus subsidence. All segments had tibia callus subsidence ranging from 4 mm to 3.2 cm with 54% having significant subsidence of more than 1 cm. Multivariate regression analysis revealed only the amount of lengthening and callus patterns to be significant. In conclusion, we can say that tibia callus subsidence is a significant delayed complication and factors affecting it can be used to determine the time of fixator removal.

Altered sensory experience induces targeted rewiring of local excitatory connections in mature neocortex.

Experience-dependent plasticity in adulthood is slower than during development. Previous experience can accelerate adult cortical plasticity. However, the contributions of functional synaptic changes and modifications in neuronal structure to the acceleration of adult cortical plasticity remain unclear. If structural remodeling was important then it should be exhibited by neuronal connections that have altered during plasticity. We trimmed rodents' whiskers to induce experience-dependent plasticity and reconstructed pairs of layer 2/3 (L2/3) pyramidal neurons after electrophysiological recording. We reported recently that local excitatory connections strengthen without a change in synapse number in cortex with retained sensory input (spared) (Cheetham et al., 2007). Here, we show that strengthened connections are rewired. The rewiring involves remodeling of the axonal arbor of excitatory connections with only minor changes in postsynaptic dendritic trees. The axonal remodeling resulted in a greater length of presynaptic axon close to postsynaptic dendrites at existing local excitatory connections in spared cortex. In control cortex, the length of axon close to dendrite in unconnected pairs of L2/3 pyramidal neurons was similar to that in synaptically connected pairs of L2/3 pyramidal neurons. This finding suggests that the probability of forming a synapse and, therefore, establishing a connection, is not driven solely by the length of axon close to dendrite. The axonal remodeling that we describe is not associated with altered synapse number, but instead increases the number of sites where synapses could be formed between synaptically connected neurons with minimal structural changes. This enables rapid and cost-efficient rewiring of local excitatory connections when re-exposed to similarly altered sensory experience in adulthood.

Predictors of Functional Outcome Following Transsyndesmotic Screw Fixation of Ankle Fractures

Given the continued debate regarding syndesmotic screw fixation, we reviewed our institution's series of ankle syndesmotic screw insertions: 1) to examine technical aspects of syndesmotic screw fixation; and 2) to identify predictors of function and quality of life utilizing validated instruments. Retrospective observational study (level IV). Three university hospitals. All patients with ankle injuries who received syndesmotic screw fixation at 3 university-affiliated hospitals from 1998 to 2001. A combined hospital database for all 3 university affiliated hospitals was searched to identify all ankle fractures. Potentially eligible patients' charts were hand searched to determine the use of syndesmotic screw fixation. Radiographs from each patient were assessed for final eligibility for study inclusion. Baseline demographic information, fracture type (Lauge-Hansen, AO Weber), radiographic measurements of syndesmotic reduction, type of implants (number of screws, number of cortices, screw size), and screw removal at follow-up were determined. All radiographs were standardized for magnification. Patients also reported return to work, a visual analogue ankle pain score, and completed 2 functional outcomes instruments (Short Musculoskeletal Functional Assessment Index, Olerud and Molander Scale). Return to work, a visual analogue ankle pain score, and 3 functional outcomes instruments (Short Musculoskeletal Functional Assessment Index, Olerud and Molander Scale). Of 425 ankle fractures treated, 51 fractures had syndesmotic screw fixation. Patients were often males (67%), mean age 40.0 +/- 18.0 years, with sedentary occupations (88%), and twisting injuries (80%). Seventy percent of injuries were pronation external rotation injuries, and 30% were supination external rotation injuries. The ankle was dislocated in 45% of cases. The most common constructs for fixation included lateral plates with syndesmotic screws (45%). The majority of constructs included a single 3.5-mm cortical screw through 3 cortices of bone. Based upon postoperative x-rays, 16% of syndesmoses were not reduced. Additionally, 8 patients were deemed have inappropriate/lack of indications for syndesmotic screw insertion. At final follow-up (N = 39 patients, mean 18.1 months), patients achieved good function and quality of life (mean scores: Short Musculoskeletal Functional Assessment functional index = 11.4 +/- 10.6, Short Musculoskeletal Functional Assessment bother index = 13.5 +/- 13.1, Olerud and Molander = 74.1 +/- 23.4, visual analogue pain scale = 1.7 +/- 1.9). The only significant predictor of functional outcome was reduction of the syndesmosis (P = 0.04). This variable alone accounted for 18% of the variation in Short Musculoskeletal Functional Assessment Index physical function scores and 15% of the variance in the Olerud and Molander (running subscale) outcome measure. Our findings suggest: 1) technical aspects of syndesmotic screw fixation vary between surgeons; 2) 16% of syndesmotic screws may have been unnecessary; and 3) despite variability in technique and indications, anatomic reduction of syndesmosis was significantly associated with improved Short Musculoskeletal Functional Assessment Index functional outcome. Larger, prospective studies are needed to further explore our findings.

Interobserver and intraobserver variation in the assessment of the healing of tibial fractures after intramedullary fixation.

The reliability of the radiological assessment of the healing of tibial fractures remains undetermined. We examined the inter- and intraobserver agreement of the healing of such fractures among four orthopaedic trauma surgeons who, on two separate occasions eight weeks apart, independently assessed the radiographs of 30 patients with fractures of the tibial shaft which had been treated by intramedullary fixation. The radiographs were selected from a database to represent fractures at various stages of healing. For each radiograph, the surgeon scored the degree of union, quantified the number of cortices bridged by callus or with a visible fracture line, described the extent and quality of the callus, and provided an overall rating of healing. The interobserver chance-corrected agreement using a quadratically weighted kappa (kappa) statistic in which values of 0.61 to 0.80 represented substantial agreement were as follows: radiological union scale (kappa= 0.60); number of cortices bridged by callus (kappa = 0.75); number of cortices with a visible fracture line (kappa= 0.70); the extent of the callus (kappa = 0.57); and general impression of fracture healing (kappa = 0.67). The intraobserver agreement of the overall impression of healing (kappa = 0.89) and the number of cortices bridged by callus (kappa = 0.82) or with a visible fracture line (kappa = 0.83) was almost perfect. There are no validated scales which allow surgeons to grade fracture healing radiologically. Among those examined, the number of cortices bridged by bone appears to be a reliable, and easily measured radiological variable to assess the healing of fractures after intramedullary fixation.