33 research outputs found

    Bentho-Pelagic Divergence of Cichlid Feeding Architecture Was Prodigious and Consistent during Multiple Adaptive Radiations within African Rift-Lakes

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    <b>Background</b> How particular changes in functional morphology can repeatedly promote ecological diversification is an active area of evolutionary investigation. The African rift-lake cichlids offer a calibrated time series of the most dramatic adaptive radiations of vertebrate trophic morphology yet described, and the replicate nature of these events provides a unique opportunity to test whether common changes in functional morphology have repeatedly facilitated their ecological success.<p></p> <b>Methodology/Principal Findings</b> Specimens from 87 genera of cichlid fishes endemic to Lakes Tanganyka, Malawi and Victoria were dissected in order to examine the functional morphology of cichlid feeding. We quantified shape using geometric morphometrics and compared patterns of morphological diversity using a series of analytical tests. The primary axes of divergence were conserved among all three radiations, and the most prevalent changes involved the size of the preorbital region of the skull. Even the fishes from the youngest of these lakes (Victoria), which exhibit the lowest amount of skull shape disparity, have undergone extensive preorbital evolution relative to other craniofacial traits. Such changes have large effects on feeding biomechanics, and can promote expansion into a wide array of niches along a bentho-pelagic ecomorphological axis.<p></p> <b>Conclusions/Significance</b> Here we show that specific changes in trophic anatomy have evolved repeatedly in the African rift lakes, and our results suggest that simple morphological alterations that have large ecological consequences are likely to constitute critical components of adaptive radiations in functional morphology. Such shifts may precede more complex shape changes as lineages diversify into unoccupied niches. The data presented here, combined with observations of other fish lineages, suggest that the preorbital region represents an evolutionary module that can respond quickly to natural selection when fishes colonize new lakes. Characterizing the changes in cichlid trophic morphology that have contributed to their extraordinary adaptive radiations has broad evolutionary implications, and such studies are necessary for directing future investigations into the proximate mechanisms that have shaped these spectacular phenomena

    The technique of S2-alar-iliac screw fixation: a literature review

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    The distal fixation in thoracolumbar deformity surgery can be challenging for spine surgeons. When isolated S1-pedicle screws are utilized as the sole distal fixation in long thoracolumbar posterior constructs, there is a high rate of failure, due to loosening, breakage, and pseudarthrosis. Unfortunately, with iliac screw fixation the entry point at the posterior superior iliac spine requires considerable soft tissue dissection and may potentially increase the likelihood of wound complications. S2-alar-iliac (S2AI) screw fixation technique was developed recently to provide increased fixation with a lower profile screw and rod construct. These screws can be inserted with percutaneous or free hand techniques. This fixation also has comparable biomechanical properties to the S1 iliac screw. This technique may provide advantages such as decreased rates of reoperation, surgical site infection, wound dehiscence and symptomatic screw prominence as compared to traditional iliac screw fixation. The purpose of this manuscript is to review the S2AI screw fixation literature including anatomy, technique, biomechanics, and clinical outcomes

    31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two

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    Background The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd. Methods We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background. Results First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001). Conclusions In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival

    Perioperative considerations in nonagenarians

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    Objective: The nation\u27s aging population presents novel perioperative challenges. Potential benefits of operative interventions must be scrutinized in relation to recoverable quality of life. The purpose of this study is to evaluate common risk calculators used for medical decision making in a nonagenarian patient population. Methods: Retrospective medical record review was performed on patients 90 years or older who underwent operative interventions requiring anesthesia at a large academic medical center between January 1, 2013, and December 31, 2017. GraphPad 8.2.1 was used for statistical analysis. Results: Significant differences were found when data were stratified by age for elective versus emergent cases (P value \u3c .0001), ability to return to baseline function (P value = .0062), and mortality (P value \u3c .0001). Significant differences were found in emergent and elective cases, ability to return to baseline function, readmissions, and mortality (all P values \u3c .0001) when stratified by American Society of Anesthesiologists score. Ability of patients to return to baseline functionality after intervention was influenced by their preintervention level of functionality (P value = .0008). American College of Surgeons and Portsmouth Physiologic and Operative Severity Score for Enumeration of Mortality and Morbidity risk calculators underestimated the need for rehabilitation and overestimated mortality for this population (all P values \u3c .0001). Conclusion: Perioperative cares of the extreme geriatric population are complex and should be approached collaboratively. Rehabilitation and postoperative assistance resources should be assessed and used fully. Input from palliative care teams should be sought appropriately. End-of-life and escalation-of-care discussions should ideally be organized prior to emergent interventions. Frailty and risk calculators should be used and considered for formal implementation into the preoperative workflow

    Improving Social Engagement and Initiations between Children with Autism Spectrum Disorder and Their Peers in Inclusive Settings.

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    Children with Asperger's Disorder often have difficulty with peer relationships and socialization. The current study assessed whether peer social interactions would improve in school settings if an intervention was designed that incorporated the children with Asperger's interests. Three children who were fully-included in regular education classes but did not interact with peers prior to intervention participated in this research. Social lunch clubs, open to both the study participants and their typical peers, were implemented twice weekly during regular lunchtime periods. Results showed that all three children increased their time engaged with peers as a result of the clubs. While their initiations greatly improved over baseline levels and approximated their peers, they were often initiating below the level of most of their peers. Implications for improving peer social interactions for children with Asperger's Disorder are discussed

    Improving Social Engagement and Initiations Between Children With Autism Spectrum Disorder and Their Peers in Inclusive Settings

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    Children with Asperger’s Disorder often have difficulty with peer relationships and socialization. The current study assessed whether peer social interactions would improve in school settings if an intervention was designed that incorporated the children with Asperger’s interests. Three children who were fully-included in regular education classes but did not interact with peers prior to intervention participated in this research. Social lunch clubs, open to both the study participants and their typical peers, were implemented twice weekly during regular lunchtime periods. Results showed that all three children increased their time engaged with peers as a result of the clubs. While their initiations greatly improved over baseline levels and approximated their peers, they were often initiating below the level of most of their peers. Implications for improving peer social interactions for children with Asperger’s Disorder are discussed

    Risk Factors for Medical and Surgical Complications After 1–2-Level Anterior Cervical Discectomy and Fusion Procedures

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    Background Postoperative complications after anterior cervical discectomy and fusion (ACDF) have a significant impact on clinical outcomes and health care resource use. Identifying predictive factors for complications after ACDF may allow for the modification of care protocols to mitigate complication risk. The purpose of this study is to determine risk factors for the incidence of medical and surgical complications up to 2 years postoperatively after ACDF procedures. Methods A prospectively maintained surgical registry of patients who underwent primary, 1–2-level ACDF was retrospectively reviewed. The incidence of medical and surgical complications up to 2 years postoperatively was determined. Patients were classified according to demographic, comorbidity, and procedural characteristics. Bivariate Poisson regression with robust error variance was used to determine if an association existed between the incidence of medical or surgical complications and patient characteristics. A final multivariate model including all patient and procedural characteristics as controls was created using backwards, stepwise regression until only those variables with P \u3c .05 remained. Results A total of 310 patients were included. Upon bivariate analysis, age \u3e50 years was identified as a risk factor for medical complications after ACDF procedures. Additionally, bivariate analysis identified ageless Charlson comorbidity index ≥2, operative duration \u3e60 minutes, and 2-level procedures as risk factors for surgical complications after ACDF. Upon multivariate analysis, age \u3e50 years was identified as an independent risk factor for medical complications (relative risk [RR] = 3.6, P = .005), while operative time \u3e60 minutes was identified as an independent risk factor for surgical complications after ACDF (RR = 4.5, P = .017). Conclusions The results of this study demonstrate that older age and longer operative time were independent risk factors for medical and surgical complications, respectively, following ACDF. Patients with these risk factors should be counseled regarding their increased risk of postoperative complications and should undergo more vigilant monitoring to aid in complication avoidance. Level of Evidence 3. Clinical Relevance Surgeons should consider the elevated risk of postoperative complications in \u3e50 years old patients and \u3e60 min procedures

    Impact of Body Mass Index on Surgical Outcomes, Narcotics Consumption, and Hospital Costs Following Anterior Cervical Discectomy and Fusion

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    OBJECTIVE Given the increasing prevalence of obesity, more patients with a high body mass index (BMI) will require surgical treatment for degenerative spinal disease. In previous investigations of lumbar spine pathology, obesity has been associated with worsened postoperative outcomes and increased costs. However, few studies have examined the association between BMI and postoperative outcomes following anterior cervical discectomy and fusion (ACDF) procedures. Thus, the purpose of this study was to compare surgical outcomes, postoperative narcotics consumption, complications, and hospital costs among BMI stratifications for patients who have undergone primary 1- to 2-level ACDF procedures. METHODS The authors retrospectively reviewed a prospectively maintained surgical database of patients who had undergone primary 1- to 2-level ACDF for degenerative spinal pathology between 2008 and 2015. Patients were stratified by BMI as follows: normal weight (\u3c 25.0 kg/m2), overweight (25.0–29.9 kg/m2), obese I (30.0–34.9 kg/m2), or obese II–III (≥ 35.0 kg/m2). Differences in patient demographics and preoperative characteristics were compared across the BMI cohorts using 1-way ANOVA or chi-square analysis. Multivariate linear or Poisson regression with robust error variance was used to determine the presence of an association between BMI category and narcotics utilization, improvement in visual analog scale (VAS) scores, incidence of complications, arthrodesis rates, reoperation rates, and hospital costs. Regression analyses were controlled for preoperative demographic and procedural characteristics. RESULTS Two hundred seventy-seven patients were included in the analysis, of whom 20.9% (n = 58) were normal weight, 37.5% (n = 104) were overweight, 24.9% (n = 69) were obese I, and 16.6% (n = 46) were obese II–III. A higher BMI was associated with an older age (p = 0.049) and increased comorbidity burden (p = 0.001). No differences in sex, smoking status, insurance type, diagnosis, presence of neuropathy, or preoperative VAS pain scores were found among the BMI cohorts (p \u3e 0.05). No significant differences were found among these cohorts as regards operative time, intraoperative blood loss, length of hospital stay, and number of operative levels (p \u3e 0.05). Additionally, no significant differences in postoperative narcotics consumption, VAS score improvement, complication rates, arthrodesis rates, reoperation rates, or total direct costs existed across BMI stratifications (p \u3e 0.05). CONCLUSIONS Patients with a higher BMI demonstrated surgical outcomes, narcotics consumption, and hospital costs comparable to those of patients with a lower BMI. Thus, ACDF procedures are both safe and effective for all patients across the entire BMI spectrum. Patients should be counseled to expect similar rates of postoperative complications and eventual clinical improvement regardless of their BMI
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