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Copyright of Acta Ortopédica Mexicana is the property of Sociedad Mexicana de Ortopedia, AC and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Ortopédica Mexicana is the property of Sociedad Mexicana de Ortopedia, AC and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

There are various approaches and surgical techniques with the objective of nerve root decompression, restrict mobility, and fusion of the listhesis. Among the techniques, posterior interbody fusion combines direct and indirect root decompression with the fusion between vertebral bodies, placing an autologous bone graft between transverse apophysis and vertebral bodies. Transforaminal lumbar and posterior interbody fusion, on the same way, look to decompress and fuse but with a different approach to the spine. The anterior approach for interbody fusion provides a better fusion rate. Lateral lumbar interbody fusion is considered less invasive, with an anterolateral transpsoas approach. The lumbar fusion technique in degenerative spondylolisthesis must be individualized. Non-fusion decompression is considered a less invasive procedure. Various studies suggest that decompression has better results when fusion is added. Surgery had several potential benefits and greater improvement in those patients who fail conservative management. An optimal technique is not conclusively identified.

Lumbar degenerative spondylolisthesis is the result of the progression from degenerative changes in the intervertebral disc and facet joints that lead to destabilizing one or more vertebral segments. It is characterized by the anterior sliding of the vertebral body secondary to the sagittalization of the facet joints. Wiltse, Newman, and Macnab classified it as type III. It is a pathology typical of elderly patients that predominate in women with a ratio of 5:1 compared to men; the most affected segment is L4-L5, the listhesis rarely exceeds 30% slip. It may or may not generate clinical manifestations, and the severity of these does not always correlate with the degree of sliding. The cardinal symptom is lumbar pain with or without radicular pain. Neurogenic claudication occurs in 75% of patients; it is caused by blood hypoperfusion secondary to the compression of the nerve roots, manifesting as pain in the lower limbs with variable walking distances. For the diagnosis of degenerative spondylolisthesis, comprehensive evaluation with static, dynamic radiographic studies in a standing position and magnetic resonance imaging are essential. The conservative treatment is the first-line therapy; it includes analgesics, anti-inflammatories, physiotherapy.

The Os odontoideum is a variable oval or round ossicle with a smooth cortical border, which partially corresponds to the odontoid process, without having continuity with the rest of C2 bone. The multifactorial etiology causes instability and clinically translates into pain and compression data into neural structures. The treatment of choice is surgical and techniques have been developed that focus on preserving the stability of the segment. We present the case of a 23-year-old female patient, who begins to suffer at 8 years of age, refers to moderate to severe cervicalgia, which develops with paresthesias in the left hemisphere and later paresis of the left thoracic limb. Physical examination showed hypoaesthesia of the left hemisphere, as well as paresis of the left thoracic limb. Extension studies demonstrate chronic axonal lesion from C1 to C3, predominantly left, imaging studies showing axial instability and magnetic resonance bulbar compression. The patient receives surgical treatment consisting of posterior fixation C1-C2, evolving satisfactorily.

Introducción: Los cambios en el ligamento flavum (LF) relacionados con la degeneración son secundarios al proceso de envejecimiento o a la inestabilidad mecánica. Estudios anteriores han indicado que LF con envejecimiento muestra pérdida de fibras elásticas y aumento del contenido de colágeno, la pérdida de elasticidad puede hacer que el LF se pliegue en el canal espinal, disminuyendo su espacio., Material Y Métodos: Se incluyeron 67 pacientes operados de estenosis lumbar espinal (LSS), hernia de disco lumbar (LDH) y espondilolistesis degenerativa (LDS). Se obtuvieron muestras de LF de pacientes que tenían LSS (39), LDH (22) y LDS (6). Se examinaron especímenes con respecto a metaplasia condroide, calcificación, fragmentación de fibras de colágeno, degeneración quística, apariencia fibrilar e hipercelularidad., Resultados: Los cambios histopatológicos más frecuentes fueron la hialinización y la fragmentación de las fibras de colágeno (34%), neovascularización en 40.3%, y la disposición irregular de las fibras elásticas es el cambio más frecuente con 56.7% del total de muestras. Existe una diferencia en la presencia de cambios en el LF, de acuerdo con el diagnóstico, siendo estadísticamente significativo para la fragmentación de las fibras de colágeno (p = 0.045), la degeneración quística (p = 0.001), la apariencia fibrilar (p = 0.007) y la hipercelularidad (p = 0.005) todos ellos, siendo más frecuentes en el grupo LDS. El grupo LHD presentó fragmentación de las fibras de colágeno en 45.5% (p = 0.045) y la apariencia fibrilar en 4.5% (p = 0.009)., Conclusiones: No hay evidencia de hipertrofia celular en los análisis histopatológicos, el engrosamiento del LF se puede ver por abultamiento del mismo, seguido de colapso del segmento de movimiento.

The role of soot particles as ice nuclei (IN) in heterogeneous freezing processes in the atmosphere remains uncertain. Determination of the freezing efficiency of soot is complicated by the changing properties of soot particles undergoing atmospheric aging processes. In this study, the heterogeneous freezing temperatures of droplets in contact with fresh and oxidized soot particles were determined using an optical microscope apparatus equipped with a sealed cooling stage and a CCD video camera. Experiments were also conducted using fresh and oxidized polycyclic aromatic hydrocarbons (PAHs), including anthracene, pyrene, and phenanthrene, as potential ice nuclei. Chemical changes at the surface of the aerosols caused by exposure to ozone were characterized using Fourier transform infrared spectroscopy with horizontal attenuated total reflectance (FTIR-HATR). In addition, Brunauer-Emmett-Teller (BET) measurements were used to determine the specific surface areas of the soot particles. Mean freezing temperatures on fresh particles ranged from -19 to -24 °C, depending on the IN composition and size. In all cases, exposure to ozone facilitated ice nucleation at warmer temperatures, by 2-3 °C, on average. In addition, nucleation rate coefficients for a single temperature and IN type increased by as much as 4 orders of magnitude because of oxidation. Furthermore, a fraction of the oxidized soot particles froze at temperatures above -10 °C. A modified version of classical nucleation theory that accounts for a range of contact angles on nucleation sites within an IN population was used to derive the probability of freezing as a function of temperature for each type of IN. In summary, our results suggest that atmospheric oxidation processes may both extend the range over which particles can act as ice nuclei to warmer temperatures and increase heterogeneous nucleation rates on soot and pollutant aerosols.

Background: Ligamentoplasty is a dynamic stabilization method used to treat lumbar stenosis and resect lumbar herniated discs with good results. The objective of this paper is to report preliminary results of the utility of ligamentoplasty to prevent adjacent segment disease above the arthrodesis., Material and Methods: Two groups of patients with degenerative lumbar spondylolisthesis who underwent circumferential arthrodesis. In 23 patients a dynamic stabilization system was placed in the segment above (group L), while this system was not used in 35 patients (group S). Degeneration and disease of the segment above were assessed. The statistical analysis was done with the SPSS 15.0 software., Results: At the one-year follow-up, the incidence rate of adjacent segment degeneration was 11% for group L and 0% for group S; at the two-year follow-up it was 13% in both groups; at three years, 0% for group L and 19% for group S; at four years, 25% for group L and 0% for group S. At five years, 50% for group L and 0% for group S. Clinically significant radiculopathy occurred in two patients five years after surgery, one of whom also had adjacent segment disease., Conclusions: Based on the follow-up, at this moment it is not possible to show the utility of dynamic stabilization through ligamentoplasty to avoid adjacent segment disease above the arthrodesis.

Background: Total lumbar disc replacement was developed to avoid the drawbacks of arthrodesis. This procedure should be done cautiously due to the various already known complications. The purpose of this study is to assess the clinical and radiographic results after single-level lumbar arthroplasty with the Prodisc-L, Maverick and Charité prostheses at our service., Material and Methods: A retrospective study was performed comparing the clinical and radiographic results of three groups of patients who underwent total lumbar disc arthroplasty from January 2000 to December 2007., Results: Twenty-one lumbar prosthetic surgeries were performed. The Prodisc device was used in 13 patients, the Maverick in 4, and the Charité in 4. After the application of the Stauffer-Coventry scale, 16 patients reported excellent results and 5 good results. The mean preoperative interbody height was 7.9 mm and the mean postoperative height was 12.91 mm. The mean differential angle in the dynamic films was 5.47 degrees preoperatively and 4.61 postoperatively; the mean angle in neutral position was 13.38 preoperatively and 19.61 postoperatively., Conclusions: This study showed that the clinical result was good in all three groups. Mobility was better maintained with the Charité prosthesis compared to the Prodisc and Maverick devices. The three prostheses are appropriate for the treatment of lumbar degenerative disc disease.

Background: Burn injury is frequently complicated by bacterial infection. Following burn injury, exposure to endotoxin produces a measurable decrease in cardiomyocyte sarcomere contractile function. Lipopolysaccharide-binding protein (LBP) is an acute phase protein that potentiates the recognition of lipopolysaccharide (LPS) by binding to the lipid A moiety of LPS. In this study, we sought to determine the effect of recombinant rat LBP (rLBP) on cardiomyocyte sarcomere function after burn or sham injury in the presence or absence of bacterial endotoxin., Methods: Rats underwent a full-thickness 30% total body surface area scald or sham burn. At 24 h post-injury, cardiomyocytes were isolated, plated at 50,000 cells/well, and incubated with 50 μg/mL LPS and rLBP or chloramphenicol acetyltransferase (BVCat, an irrelevant control protein produced using the same expression system as rLBP) at concentrations by volume of 1%, 5%, 10%, and 30%. Subsets of cardiomyocytes were incubated with 5% rat serum or 30% rLBP and blocking experiments were conducted using an LBP-like synthetic peptide (LBPK95A). In vitro sarcomere function was measured using a variable rate video camera system with length detection software., Results: Co-culture of burn and sham injury derived cardiomyocytes with high-dose rLBP in the presence of LPS resulted in a significant reduction to the functional impairment observed in peak sarcomere shortening following exposure to LPS alone. LBP-like peptide LBPK95A at a concentration of 20 μg/mL, in the presence of LPS, abolished the ability of 30% rLBP and 5% rat serum to restore peak sarcomere shortening of cardiomyocytes isolated following burn injury to levels of function exhibited in the absence of endotoxin exposure., Conclusions: In the setting of LPS challenge following burn injury, rLBP at high concentrations restores cardiomyocyte sarcomere contractile function in vitro. Rather than potentiating the recognition of LPS by the cellular LPS receptor complex, rLBP at high concentrations likely results in an inhibitory binding effect that minimizes the impact of endotoxin exposure on cardiomyocyte function following thermal injury., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Tetrathiomolybdate (TM), a drug developed for the treatment of Wilson's disease, produces an antiangiogenic effect by reducing systemic copper levels. Several angiogenic cytokines appear to depend on normal levels of copper for activity. In both animal tumor models and in cancer patients, TM therapy has proved effective in inhibiting the growth of tumors. We have hypothesized that the activities of fibrotic and inflammatory cytokines are also subject to modulation by the availability of copper in a manner similar to angiogenic cytokines. As a first step in evaluating whether TM plays a therapeutic role in diseases of inflammation and fibrosis, we studied the effects of TM on a murine model of bleomycin-induced pulmonary fibrosis. Oral TM therapy resulted in dose-dependent reduction in serum ceruloplasmin, a surrogate marker of systemic copper levels. Significant decreases in systemic copper levels were associated with marked reduction in lung fibrosis as determined on the basis of histopathologic findings and a biochemical measure of fibrosis. The protection afforded by TM was also reflected in significantly reduced bleomycin-induced body-weight loss. In the next phase of this work, we will seek to determine the mechanisms by which TM brings about this therapeutic benefit.