93 research outputs found

    Navigating the Murk: Ethical and Practical Considerations for the Surgical Treatment of the Sacroiliac Joint Syndrome

    Get PDF
    The field of spine surgery has many controversies. The surgical treatment of the sacroiliac (SI) joint is, too, fraught with debate. The diagnosis of painful SI joints is currently limited to relief following “diagnostic” injections and pain generated from a suite of clinical maneuvers. Diagnoses of SI joint dysfunction are dependent entirely on patient-reported responses to provocative maneuvers and invasive procedures. There is a glaring lack of objective radiographic and objective physical examination findings for this syndrome. The evidence for treatment, and specifically for the surgical treatment of the SI joint is reviewed and critiqued. Although the surgical techniques are simple, consensus is elusive for both indication and optimal technique. Ethical principles for surgical innovation and practical considerations for the treatment of the SI joint syndrome are discussed at length. Discussed as well are key points to consider when providing informed consent to a patient before proceeding with surgical intervention for this procedure and diagnosis. Spine surgery is a field with considerable regional variation in practice. Even today, the precise indications for arthrodesis, extent, and approach, remain frequently debated; however, as much conversation takes place surrounding lumbar surgery, even more confusion, bias, opinion, and deliberation exists when surgical treatment of the SI joint is considered. This chapter discusses the unique challenges associated with the SI joint and provides practical considerations for the treatment thereof.Open access articleThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

    ANTERIOR CERVICAL SURGICAL RETRACTOR DESIGN

    Get PDF
    INTRODUCTION During anterior cervical surgeries such as discectomies and corpectomies (removal of the disc separating two vertebrae and removal of the vertebral body itself, respectively1), surgeons implement a retractor device to broaden the view of the spinal area on which they are operating.  The current devices have flaws; including a lack of stability, complicated mechanisms, multiple pieces, or difficulty stacking, and a new retractor is needed.  Stacking, occurs in a multiple level surgery, when more than two or more devices are needed simultaneously to hold the area open.  Our design utilizes the distraction screw to stabilize the retractor in position, without the impediment of the device becoming an obstacle for the surgeons to manoeuvre around. METHODS Based on the expertise of the experienced surgeons, multiple models will be drawn.  The most practical concept will then be developed on autoCAD software.  The lower width of the blades uses a simple rotation-linear motion system.  Meanwhile, the upper part of the blade is rotated about the lower part, allowing the blade to be used at an angle. RESULTS A physical model of the device (as seen in Figure 1 below) has yet to be printed and tested.  Nevertheless, the new model is placed within the patient, allowing the surgeons to work without worrying about the device being an obstruction.  The blades are angled wider at the top and narrower at the bottom), making it easier for the surgeons’ hands to fit in the small void in the patient’s neck. DISCUSSION AND CONCLUSIONS Since a prototype has not been created or clinically tested yet, all results and conclusions are merely speculations.  Our new device is: simple to use, less obstructive, and able to provide a broader view of the operating area.  In addition, in the rare event that these longer blades require stacking, it is very simple to implement.  The surgeon will simply place a second retractor on the second distraction screw. Since every patient is a different size, the blades must be interchangeable.  This way the surgeon can choose what length and height he/she wants the blade to be for each surgery.  Similar to the previous devices, the blades are curved at the bottom with teeth; this helps the device bite into the soft tissue and minimize slipping.  The blades will be made of titanium, which is strong, radiolucent, and easy to sterilize

    Methylprednisolone for acute spinal cord injury: An inappropriate standard of care

    Get PDF
    N 1987, high forceps were used to deliver a newborn girl in a hospital in Southern California. Acute SCI remains a devastating condition, and little progress has been made toward improving or curing neurological outcome. However, since the results of NASCIS II were published in 1990, the use of MP in the treatment of this disorder has become an accepted standard. 3,7 The 1-year follow-up results from NASCIS II have been reported 4 but were less publicized. Since early and 1-year results from NASCIS III have become available, acute care medical institutions are presently faced with the decision of whether to incorporate the recommended 48-hour protocol proposed in this latest study into their existing 24-hour protocols. Methods. Published results from NASCIS II and III were reviewed in the context of the original study design, including primary outcomes compared with post-hoc comparisons. Data were retroconverted from tabular form back to raw form to allow direct inspection of changes in treatment groups. These findings were further analyzed with respect to justification of practice standards. Although well-designed and well-executed, both NASCIS II and III failed to demonstrate improvement in primary outcome measures as a result of the administration of methylprednisolone. Post-hoc comparisons, although interesting, did not provide compelling data to establish a new standard of care in the treatment of patients with acute SCI. Conclusions. The use of methylprednisolone administration in the treatment of acute SCI is not proven as a standard of care, nor can it be considered a recommended treatment. Evidence of the drug's efficacy and impact is weak and may only represent random events. In the strictest sense, 24-hour administration of methylprednisolone must still be considered experimental for use in clinical SCI. Forty-eight-hour therapy is not recommended. These conclusions are important to consider in the design of future trials and in the medicolegal arena. KEY WORD

    Surgical Decision Making for Unstable Thoracolumbar Spine Injuries: Results of a Consensus Panel Review by the Spine Trauma Study Group

    Get PDF
    Objectives: The optimal surgical approach and treatment of unstable thoracolumbar spine injuries are poorly defined owing to a lack of widely accepted level I clinical literature. This lack of evidence based standards has led to varied practice patterns based on individual surgeon preferences. The purpose of this study was to survey the leaders in the field of spine trauma to define the major characteristics of thoracolumbar injuries that influence their surgical decision making. In the absence of good scientific data, expert consensus opinions may provide surgeons with a practical framework to guide therapy and to conduct future research. Methods: A panel of 22 leading spinal surgeons from 20 level I trauma centers in seven countries met to discuss the indications for surgical approach selection in unstable thoracolumbar injuries. Injuries were presented to the surgeons in a case scenario survey format. Preferred surgical approaches to the clinical scenarios were tabulated and comments weighed. Results: All members of the panel agreed that three independent characteristics of thoracolumbar injuries carry primary importance in surgical decision making: the injury morphology, the neurologic status of the patient, and the integrity of the posterior ligaments. Six clinical scenarios based on the neurologic status of the patient (intact, incomplete, or complete) and on the status of the posterior ligamentous complex (intact or disrupted) were created, and consensus treatment approaches were described. Additional circumstances capable of altering the treatments were acknowledged. Conclusions: Decision making for the surgical treatment of thoracolumbar injuries is largely dependent on three patient characteristics: injury morphology, neurologic status, and posterior ligament integrity. A logical and practical decision-making process based on these characteristics may guide treatment even for the most complicated fracture patterns

    Aesthetic response to color combinations: preference, harmony, and similarity

    Get PDF
    Previous studies of preference for and harmony of color combinations have produced confusing results. For example, some claim that harmony increases with hue similarity, whereas others claim that it decreases. We argue that such confusions are resolved by distinguishing among three types of judgments about color pairs: (1) preference for the pair as a whole, (2) harmony of the pair as a whole, and (3) preference for its figural color when viewed against its colored background. Empirical support for this distinction shows that pair preference and harmony both increase as hue similarity increases, but preference relies more strongly on component color preference and lightness contrast. Although pairs with highly contrastive hues are generally judged to be neither preferable nor harmonious, figural color preference ratings increase as hue contrast with the background increases. The present results thus refine and clarify some of the best-known and most contentious claims of color theorists

    Low oxygen affects photophysiology and the level of expression of two-carbon metabolism genes in the seagrass <i>Zostera muelleri</i>

    Get PDF
    © 2017, Springer Science+Business Media B.V. Seagrasses are a diverse group of angiosperms that evolved to live in shallow coastal waters, an environment regularly subjected to changes in oxygen, carbon dioxide and irradiance. Zostera muelleri is the dominant species in south-eastern Australia, and is critical for healthy coastal ecosystems. Despite its ecological importance, little is known about the pathways of carbon fixation in Z. muelleri and their regulation in response to environmental changes. In this study, the response of Z. muelleri exposed to control and very low oxygen conditions was investigated by using (i) oxygen microsensors combined with a custom-made flow chamber to measure changes in photosynthesis and respiration, and (ii) reverse transcription quantitative real-time PCR to measure changes in expression levels of key genes involved in C4 metabolism. We found that very low levels of oxygen (i) altered the photophysiology of Z. muelleri, a characteristic of C3 mechanism of carbon assimilation, and (ii) decreased the expression levels of phosphoenolpyruvate carboxylase and carbonic anhydrase. These molecular-physiological results suggest that regulation of the photophysiology of Z. muelleri might involve a close integration between the C3 and C4, or other CO2 concentrating mechanisms metabolic pathways. Overall, this study highlights that the photophysiological response of Z. muelleri to changing oxygen in water is capable of rapid acclimation and the dynamic modulation of pathways should be considered when assessing seagrass primary production

    Disentangling the relative effects of bushmeat availability on human nutrition in central Africa

    Get PDF
    We studied links between human malnutrition and wild meat availability within the Rainforest Biotic Zone in central Africa. We distinguished two distinct hunted mammalian diversity distributions, one in the rainforest areas (Deep Rainforest Diversity, DRD) containing taxa of lower hunting sustainability, the other in the northern rainforest-savanna mosaic, with species of greater hunting potential (Marginal Rainforest Diversity, MRD). Wild meat availability, assessed by standing crop mammalian biomass, was greater in MRD than in DRD areas. Predicted bushmeat extraction was also higher in MRD areas. Despite this, stunting of children, a measure of human malnutrition, was greater in MRD areas. Structural equation modeling identified that, in MRD areas, mammal diversity fell away from urban areas, but proximity to these positively influenced higher stunting incidence. In DRD areas, remoteness and distance from dense human settlements and infrastructures explained lower stunting levels. Moreover, stunting was higher away from protected areas. Our results suggest that in MRD areas, forest wildlife rational use for better human nutrition is possible. By contrast, the relatively low human populations in DRD areas currently offer abundant opportunities for the continued protection of more vulnerable mammals and allow dietary needs of local populations to be met

    Comparative genomics reveals diversity among xanthomonads infecting tomato and pepper

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Bacterial spot of tomato and pepper is caused by four <it>Xanthomonas </it>species and is a major plant disease in warm humid climates. The four species are distinct from each other based on physiological and molecular characteristics. The genome sequence of strain 85-10, a member of one of the species, <it>Xanthomonas euvesicatoria </it>(<it>Xcv</it>) has been previously reported. To determine the relationship of the four species at the genome level and to investigate the molecular basis of their virulence and differing host ranges, draft genomic sequences of members of the other three species were determined and compared to strain 85-10.</p> <p>Results</p> <p>We sequenced the genomes of <it>X. vesicatoria </it>(<it>Xv</it>) strain 1111 (ATCC 35937), <it>X. perforans </it>(<it>Xp</it>) strain 91-118 and <it>X. gardneri </it>(<it>Xg</it>) strain 101 (ATCC 19865). The genomes were compared with each other and with the previously sequenced <it>Xcv </it>strain 85-10. In addition, the molecular features were predicted that may be required for pathogenicity including the type III secretion apparatus, type III effectors, other secretion systems, quorum sensing systems, adhesins, extracellular polysaccharide, and lipopolysaccharide determinants. Several novel type III effectors from <it>Xg </it>strain 101 and <it>Xv </it>strain 1111 genomes were computationally identified and their translocation was validated using a reporter gene assay. A homolog to Ax21, the elicitor of XA21-mediated resistance in rice, and a functional Ax21 sulfation system were identified in <it>Xcv</it>. Genes encoding proteins with functions mediated by type II and type IV secretion systems have also been compared, including enzymes involved in cell wall deconstruction, as contributors to pathogenicity.</p> <p>Conclusions</p> <p>Comparative genomic analyses revealed considerable diversity among bacterial spot pathogens, providing new insights into differences and similarities that may explain the diverse nature of these strains. Genes specific to pepper pathogens, such as the O-antigen of the lipopolysaccharide cluster, and genes unique to individual strains, such as novel type III effectors and bacteriocin genes, have been identified providing new clues for our understanding of pathogen virulence, aggressiveness, and host preference. These analyses will aid in efforts towards breeding for broad and durable resistance in economically important tomato and pepper cultivars.</p
    • 

    corecore