Change in triggered EMG thresholds for thoracic pedicle screws caused by pneumothorax during surgery for adolescent idiopathic scoliosis. Report of two cases. / Alteración en los umbrales de estimulación de tornillos pediculares torácicos secundaria a neumotórax en cirugía por escoliosis idiopática del adolescente. A propósito de dos casos.

Posterior spinal instrumentation and fusion with pedicle screws inserted by free-hand technique and controlled by multimodal intraoperative monitoring is the most common technique in adolescent idiopathic scoliosis surgery. Pneumothorax is a described complication of this kind of procedure. Triggered electromyography is used to identify pedicle wall breakthrough and prevent neurological injuries. We report 2 clinical cases in which unilateral decrease in triggered electromyography values associate with ipsilateral pneumothorax. Postoperative chest radiographs need to be done in order to diagnose a pneumothorax. However, routinely performing a chest radiograph has been questioned because of the low incidence of this surgical complication. As a result of the association described in this article, we consider that when a unilateral decrease in triggered electromyography values is detected, a hidden pneumothorax should be suspected and ruled out.

Syncytiotrophoblast stress in early onset preeclampsia: The issues perpetuating the syndrome.

Preeclampsia is a pregnancy-specific syndrome characterized by a sudden increase in blood pressure accompanied by proteinuria and/or maternal multi-system damage associated to poor fetal outcome. In early-onset preeclampsia, utero-placental perfusion is altered, causing constant and progressive damage to the syncytiotrophoblast, generating syncytiotrophoblast stress. The latter leads to the detachment and release of syncytiotrophoblast fragments, anti-angiogenic factors and pro-inflammatory molecules into maternal circulation, resulting in the emergence and persistence of the characteristic symptoms of this syndrome during pregnancy. Therefore, understanding the origin and consequences of syncytiotrophoblast stress in preeclampsia is vital to develop new therapeutic alternatives, focused on reducing the burden of this syndrome. In this review, we describe five central characteristics of syncytial stress that should be targeted or prevented in order to reduce preeclampsia symptoms: histological alterations, syncytiotrophoblast damage, antiangiogenic protein export, placental deportation, and altered syncytiotrophoblast turnover. Therapeutic management of these characteristics may improve maternal and fetal outcomes.

The role of xenobiotic-metabolizing enzymes in the placenta: a growing research field.

Introduction: The placenta is a temporary and unique organ that allows for the physical connection between a mother and fetus; this organ regulates the transport of gases and nutrients mediating the elimination of waste products contained in the fetal circulation. The placenta performs metabolic and excretion functions, on the basis of multiple enzymatic systems responsible for the oxidation, reduction, hydrolysis, and conjugation of xenobiotics. These mechanisms give the placenta a protective role that limits the fetal exposure to harmful compounds. During pregnancy, some diseases require uninterrupted treatment even if it is detrimental to the fetus. Drugs and other xenobiotics alter gene expression in the placenta with repercussions for the fetus and mother's well-being.Areas covered: This review provides a brief description of the human placental structure and function, the main drug and xenobiotic transporters and metabolizing enzymes, placenta-metabolized substrates, and alterations in gene expression that the exposure to xenobiotics may cause.Expert opinion: Research should be focused on the identification and validation of biological markers for the assessment of the harmful effects of some drugs in pregnancy, including the evaluation of polymorphisms and methylation patterns in chorionic villous samples and/or amniotic fluid.

Infección quirúrgica profunda en cirugía instrumentada de raquis toracolumbar. Diez años de experiencia / Deep surgical site infection following thoracolumbar instrumented spinal surgery. Ten years of experience

Objetivo: Describir las características y la evolución de la infección profunda en cirugía instrumentada de raquis toracolumbar (IPCITL) en nuestro centro en un periodo de 10años. Material y método: Estudio descriptivo retrospectivo. Se analizan datos del paciente (epidemiológicos/salud), datos operatorios, presentación de la infección, gérmenes cultivados, limpiezas quirúrgicas requeridas, extracción de los implantes y complicaciones significativas derivadas de la infección. Resultados: Se revisan 110 pacientes (80mujeres). El seguimiento medio tras el diagnóstico de infección fue de 3,6años. Etiologías más frecuentes: escoliosis idiopática del adolescente, deformidad del adulto y estenosis lumbar degenerativa. El 62% de pacientes presentaban algún dato clínico que les hacía proclives a la infección. La aparición de la infección fue precoz (0-3meses de la cirugía primaria) en el 60,4% de los casos, retardada (3-24meses) en el 11,7% y tardía (más de 24meses) en el 27%. Todos los pacientes fueron tratados mediante limpieza quirúrgica. El 25% necesitaron más de una limpieza. Se extrajeron los implantes en el 46% de los pacientes (en el 71% de ellos en la primera limpieza). Los gérmenes aislados con mayor frecuencia fueron Staphylococcus coagulasa-negativo, Propionibacterium acnes y Enterococcus. Hubo complicaciones significativas derivadas de la IPCITL en el 15% de casos. El 88% de ellas precisaron cirugías complejas para su tratamiento. Conclusiones: Las IPCITL tardías son más frecuentes de lo esperado según la literatura. En IPCITL globalmente predominan gérmenes cutáneos. Las IPCITL provocan una alta tasa de complicaciones, que habitualmente requieren tratamiento mediante cirugías complejas

Objective: To describe thee characteristics and evolution of deep surgical site infection following thoracolumbar instrumented spinal surgery (DSITIS) in our centre over a period of ten years. Material and method: Descriptive retrospective study. Patient data (epidemiological/health status), surgical data, infection characteristics/presentation, isolated microorganisms, required surgical debridements, implant removal and major complications linked to infection were evaluated. Results: We included 110 patients (80 females). Median follow-up after infection diagnosis was 3.6years. Adolescent idiopathic scoliosis, adult deformity and degenerative lumbar stenosis were the most frequent aetiologies. Sixty-two percent of the patients had at least one clinical feature that made them prone to infection. Infection presentation was early (0-3months from first surgery) in 60.4% of the cases, delayed (3-24months) in 11.7%, and late (more than 24months) in 27%. All patients were treated by surgical debridement. Twenty-five percent needed more than one surgical debridement. Implants were removed in 46% of the patients (71% in the first surgical debridement). The most frequent isolated microorganisms were coagulasa-negative Staphylococcus, Propionibacterium acnes and Enterococcus. Major complications appeared in 15% of the patients, and 88% of them required major surgeries. Conclusions: Late DSITIS is more frequent than previously reported. Skin microorganisms predominate among the DSITIS culprits. DSIITS produce a high rate of major complications that usually require major surgery for treatment

Deep surgical site infection following thoracolumbar instrumented spinal surgery. Ten years of experience. / Infección quirúrgica profunda en cirugía instrumentada de raquis toracolumbar. Diez años de experiencia.

OBJECTIVE: To describe the characteristics and evolution of deep surgical site infection following thoracolumbar instrumented spinal surgery (DSITIS) in our centre over a period of ten years. MATERIAL AND METHOD: Descriptive retrospective study. Patient data (epidemiological/health status), surgical data, infection characteristics/presentation, isolated microorganisms, required surgical debridements, implant removal and major complications linked to infection were evaluated. RESULTS: We included 110 patients (80 females). Median follow-up after infection diagnosis was 3.6years. Adolescent idiopathic scoliosis, adult deformity and degenerative lumbar stenosis were the most frequent aetiologies. Sixty-two percent of the patients had at least one clinical feature that made them prone to infection. Infection presentation was early (0-3months from first surgery) in 60.4% of the cases, delayed (3-24months) in 11.7%, and late (more than 24months) in 27%. All patients were treated by surgical debridement. Twenty-five percent needed more than one surgical debridement. Implants were removed in 46% of the patients (71% in the first surgical debridement). The most frequent isolated microorganisms were coagulasa-negative Staphylococcus, Propionibacterium acnes and Enterococcus. Major complications appeared in 15% of the patients, and 88% of them required major surgeries. CONCLUSIONS: Late DSITIS is more frequent than previously reported. Skin microorganisms predominate among the DSITIS culprits. DSIITS produce a high rate of major complications that usually require major surgery for treatment.

Participation of protein kinases and phosphatases in the progesterone-induced acrosome reaction and calcium influx in human spermatozoa.

In human spermatozoa, protein kinases have a role in the acrosome reaction (AR) induced by a variety of stimuli. However, there is disagreement or a lack of information regarding the role of protein kinases and phosphatases in the progesterone (P)-induced increase in intracellular calcium concentration ([Ca2+ ]i ). In addition, there are no studies regarding the role of Ser/Thr and Tyr phosphatases and there are contradictory results regarding the role of Tyr kinases in the P-induced acrosome reaction. Here, we performed a simultaneous evaluation of the involvement of protein kinases and phosphatases in the P-induced acrosome reaction and in the P-induced calcium influx. Motile spermatozoa were capacitated for 18 h and different aliquots were allocated to treated or control groups and then evaluated for their ability to undergo the acrosome reaction and to increase [Ca2+ ]i in response to P. The acrosome reaction was evaluated using Pisum sativum agglutinin (PSA)-FITC, and [Ca2+ ]i was evaluated using fura 2AM. At all of the concentrations tested, PKA inhibitors significantly reduced the percentage of the P-induced acrosome reaction (p < 0.001). However, only the highest concentrations of PKA inhibitors reduced the P-induced calcium influx; lower concentrations of PKA inhibitors did not affect it. Similar results were apparent for PKC inhibitors and for tyrosine kinase inhibitors. None of the Ser/Thr phosphatase inhibitors affected the P-induced acrosome reaction or the P-induced calcium influx, except for the PP2B inhibitors that significantly reduced the P-induced acrosome reaction without affecting calcium influx. Finally, the protein tyrosine phosphatase inhibitors significantly blocked the P-induced acrosome reaction and reduced the amplitude of the P-induced calcium transient (p < 0.001) as well as the amplitude of the plateau phase (p < 0.01). The data suggest that protein kinases and possibly PP2B have a role on the acrosome reaction at some point downstream of calcium entry and that Tyr phosphatases have a role on the acrosome reaction upstream of calcium entry.

Initial Report on the Results of the Kidney Transplant Program at the Bajio Regional High Specialty Hospital.

BACKGROUND: We present the first results of our program, which is characterized by its acceptance of any candidate with chronic renal failure. Therefore, we serve all patients, regardless of their social security and socioeconomic status. METHODS: We conducted a retrospective, descriptive, cross-sectional study describing the characteristics of patients who received kidney transplants in the period from 2008 to 2015. Descriptive statistics were used to evaluate our findings. RESULTS: A total of 708 transplants were performed, with 377 (53%) involving a living donor and 331 (47%) involving deceased donors. The patients' mean age was 26 years (±12.7 SD), with a range of 5 to 69 years. Of these patients, 488 were male (68.9%), and 423 (59.7%) had no social security. The replacement therapy prior to transplantation was peritoneal dialysis in 40% of cases, hemodialysis in 57% of cases, and 3% of patients had no prior therapy. The blood group distribution was 436 (61%) type O; 177 (25%) type A; 78 (11%) type B; and 8 (1%) type AB. The average hospital stay for a living donor transplant was 9 days and 13 days in the case of a deceased donor. CONCLUSIONS: This study describes the basic clinical and epidemiological characteristics of our transplant population. These results can be used as a basis for future descriptive and prospective studies at our institution or in other inter-agency and national projects. We also highlight the rapid development of the kidney transplant program at the Bajio Regional High Specialty Hospital.

Tratamiento de la escoliosis juvenil: aumentar el tiempo entre alargamientos con la técnica de barras de crecimiento no debe comprometer necesariamente el crecimiento torácico / Treatment of juvenile scoliosis: increasing the lengthening interval with the growing rod technique should not necessarily compromise thoracic growth

Objetivo. Evaluar el crecimiento longitudinal del tórax y el control de la deformidad en una serie de pacientes con escoliosis juvenil tratados con barras de crecimiento aumentando los intervalos de tiempo entre alargamientos más de seis meses. Material y métodos. Estudio retrospectivo de ocho pacientes midiendo las siguientes variables: el ángulo de Cobb, la traslación vertebral apical, el balance coronal, la longitud torácica T1-L1, la cifosis torácica T5-T12, el ángulo de cifosis de unión proximal (CUP) y la lordosis lumbar. Se registraron las complicaciones. Resultados. Se evaluaron cinco escoliosis idiopáticas y tres casos de sindrómica (media de edad 9,4 ± 1,5 años). Se realizó una cirugía inicial y un promedio de dos retensados por paciente. El tiempo medio entre retensados fue de 15,7 meses. La corrección coronal final de la curva principal fue del 58%. La longitud torácica (T1-L1) preoperatoria fue de 20,8 cm, postoperatoria de 24,4 cm, y final de 26 cm. Al final del seguimiento el crecimiento medio del tórax fue de 5,2 cm. La cifosis preoperatoria (T5-T12) fue 33,5°, y final 32,1°. El cambio en el ángulo CUP fue de 2,5° en el seguimiento final. La mayoría de las complicaciones estuvieron relacionadas con la instrumentación. Se encontraron dos infecciones superficiales de la herida. Conclusión. En pacientes con escoliosis juvenil en formas «menos graves» tratados mediante barras de crecimiento, es posible espaciar los alargamientos más de un año y con ello disminuir el número de cirugías y al mismo tiempo controlar la deformidad y permitir el crecimiento longitudinal torácico (AU)

Objective. Serial lengthening with growing rods is recommended every six months for the treatment of early onset scoliosis. The objective of this study was to evaluate the longitudinal growth of the thorax and control of the deformity in a series of patients with juvenile scoliosis when time intervals were increased between lengthenings. Material and methods. Retrospective study of eight patients. The following variables were measured: the Cobb angle, the apical vertebral translation, the coronal balance, thoracic T1-L1 length, thoracic T5-T12 kyphosis, the proximal junctional kyphosis (PJK) angle, and the lumbar lordosis. Complications were recorded. Results. Five idiopathic and three syndromic scoliosis cases (mean age 9.4 ± 1.5 years) were evaluated. The initial surgery was followed by with an average of two distractions per patient. The mean time between distractions was 15.7 months. The final coronal main curve correction was 58%. Apical translation and coronal balance were improved and maintained after the surgeries. The thoracic (T1-L1) preoperative length was 20.8 cm, the postoperative length was 24.4 cm, and the final length was 26 cm. At the end of follow-up, the average growth of the thorax was 5.2 cm. The preoperative (T5-T12) kyphosis was 33.5°, and final 32.1°. The change in the PJK angle was 2.5° at the end of follow-up. Most complications were related to instrumentation. Two superficial wound infections were encountered. Conclusion. For less severe juvenile scoliosis patients treated with growing rods, spacing out lengthenings over more than a year can decrease the number of surgeries, while still controlling the deformity and allowing longitudinal thoracic growth (AU)

[Treatment of juvenile scoliosis: Increasing the lengthening interval with the growing rod technique should not necessarily compromise thoracic growth]. / Tratamiento de la escoliosis juvenil: aumentar el tiempo entre alargamientos con la técnica de barras de crecimiento no debe comprometer necesariamente el crecimiento torácico.

OBJECTIVE: Serial lengthening with growing rods is recommended every six months for the treatment of early onset scoliosis. The objective of this study was to evaluate the longitudinal growth of the thorax and control of the deformity in a series of patients with juvenile scoliosis when time intervals were increased between lengthenings. MATERIAL AND METHODS: Retrospective study of eight patients. The following variables were measured: the Cobb angle, the apical vertebral translation, the coronal balance, thoracic T1-L1 length, thoracic T5-T12 kyphosis, the proximal junctional kyphosis (PJK) angle, and the lumbar lordosis. Complications were recorded. RESULTS: Five idiopathic and three syndromic scoliosis cases (mean age 9.4 ± 1.5 years) were evaluated. The initial surgery was followed by with an average of two distractions per patient. The mean time between distractions was 15.7 months. The final coronal main curve correction was 58%. Apical translation and coronal balance were improved and maintained after the surgeries. The thoracic (T1-L1) preoperative length was 20.8 cm, the postoperative length was 24.4 cm, and the final length was 26 cm. At the end of follow-up, the average growth of the thorax was 5.2 cm. The preoperative (T5-T12) kyphosis was 33.5°, and final 32.1°. The change in the PJK angle was 2.5° at the end of follow-up. Most complications were related to instrumentation. Two superficial wound infections were encountered. CONCLUSION: For less severe juvenile scoliosis patients treated with growing rods, spacing out lengthenings over more than a year can decrease the number of surgeries, while still controlling the deformity and allowing longitudinal thoracic growth.

[Prognostic factors of the crankshaft phenomenon in patients with scoliosis and open triradiate cartilage. Is the double approach the solution?]. / Factores pronósticos del fenómeno de crankshaft en los pacientes con escoliosis y cartílago trirradiado abierto. ¿Es el doble abordaje la solución?

OBJECTIVE: To study young patients after scoliosis surgery in order to determine risk and prevention factors for developing a crankshaft phenomenon (CP). MATERIAL AND METHODS: Retrospective study of a cohort of 26 skeletally immature patients. Six were excluded due to progression of various conditions. Crankshaft was defined as an increase in the Cobb angle >10°, or an increase in the Mehta angle (DAVC) >10°, or any decrease in the apex-rib thoracic distance, or increase in the apical vertebral translation (AVT). Patients with and without CP development were compared in order to analyse preoperative, surgical and postoperative risk factors, as well as the influence of different surgical techniques. RESULTS: The mean follow-up was 83.9 months. Nine patients (45%) developed the crankshaft phenomenon. Only immaturity parameters were associated with development of CP. No preoperative or postoperative radiographic parameters appeared to influence its development. The amount of correction may be a protective factor (41.4 vs. 61.4%; P=.06). The double approach was able to prevent the development of CP (0%) compared with single posterior instrumentation (44%), P=.02. DISCUSSION: None of these preoperative factors seemed to predispose to CP: gender or aetiology, T5-T12 kyphosis or apical hypokyphosis, coronal Cobb, vertebral rotation, or DAVC. The residual postoperative Cobb, achieved kyphosis, or wired instrumentation versus hooks, also seemed to have no influence. CONCLUSION: In patients with open triradiate cartilage under 11 years of age, it seems advisable to correct by double approach to avoid the appearance of the crankshaft phenomenon.

Factores pronósticos del fenómeno de crankshaft en los pacientes con escoliosis y cartílago trirradiado abierto. ¿Es el doble abordaje la solución? / Prognostic factors of the crankshaft phenomenon in patients with scoliosis and open triradiate cartilage. Is the double approach the solution?

Objetivo. Estudiar los pacientes inmaduros con cartílago trirradiado abierto, operados de escoliosis, en busca de factores de riesgo y de prevención para desarrollar un fenómeno de crankshaft (CP). Material y métodos. Estudio retrospectivo de una cohorte de 26 pacientes esqueléticamente inmaduros. Seis se excluyeron por progresión de distinta etiología. Se definió crankshaft como un aumento del Cobb mayor de 10°, o un incremento en la diferencia del ángulo de Mehta (diferencia ángulo vértebra-costilla, DAVC) mayor de 10°, o cualquier disminución de la distancia ápex-costilla torácica o aumento de la traslación vertebral apical lumbar (AVT, sigla del inglés apical vertebral translation). Se compararon los pacientes con y sin desarrollo de CP para analizar los factores de riesgo preoperatorios, quirúrgicos y postoperatorios. Se estudió la influencia de las distinta técnicas quirúrgicas. Resultados. El seguimiento medio fue de 83,9 meses. Nueve pacientes (45%) desarrollaron el CP. Solo los parámetros de inmadurez ósea se asociaron al desarrollo de CP. Ningún parámetro radiográfico preoperatorio o postoperatorio parece influir en su desarrollo. La cantidad de corrección podría ser un factor de protección (41,4 vs. 61,4%; p = 0,06). El doble abordaje fue capaz de evitar el desarrollo de CP (0%) en comparación con la instrumentación única posterior (44%), p = 0,02. Discusión. No se ha conseguido demostrar que los siguientes factores preoperatorios predispongan a la aparición de crankshaft: sexo o etiología, cifosis T5-T12, hipocifosis apical, Cobb coronal, rotación vertebral o DAVC. Tampoco parecen influir el Cobb postoperatorio residual, la cifosis conseguida, o la instrumentación con alambres frente a ganchos. Conclusión. En los pacientes con cartílago trirradiado abierto menores de 11 años parece aconsejable corregir la escoliosis mediante doble abordaje para evitar el fenómeno del cigüeñal o CP (progresión de la deformidad tras una artrodesis posterior por crecimiento anterior vertebral) (AU)

Objective. To study young patients after scoliosis surgery in order to determine risk and prevention factors for developing a crankshaft phenomenon (CP). Material and methods. Retrospective study of a cohort of 26 skeletally immature patients. Six were excluded due to progression of various conditions. Crankshaft was defined as an increase in the Cobb angle >10°, or an increase in the Mehta angle (DAVC) >10°, or any decrease in the apex-rib thoracic distance, or increase in the apical vertebral translation (AVT). Patients with and without CP development were compared in order to analyse preoperative, surgical and postoperative risk factors, as well as the influence of different surgical techniques. Results. The mean follow-up was 83.9 months. Nine patients (45%) developed the crankshaft phenomenon. Only immaturity parameters were associated with development of CP. No preoperative or postoperative radiographic parameters appeared to influence its development. The amount of correction may be a protective factor (41.4 vs. 61.4%; P=.06). The double approach was able to prevent the development of CP (0%) compared with single posterior instrumentation (44%), P=.02. Discussion. None of these preoperative factors seemed to predispose to CP: gender or aetiology, T5-T12 kyphosis or apical hypokyphosis, coronal Cobb, vertebral rotation, or DAVC. The residual postoperative Cobb, achieved kyphosis, or wired instrumentation versus hooks, also seemed to have no influence. Conclusion. In patients with open triradiate cartilage under 11 years of age, it seems advisable to correct by double approach to avoid the appearance of the crankshaft phenomenon (AU)

Adaptive broadband continuum source at 1200-1400 nm based on an all-fiber dual-wavelength master-oscillator power amplifier and a high-birefringence fiber.

We experimentally analyze the stimulated Raman scattering characteristics of a high-birefringence fiber (HBF), which presents an extraordinary level of spectral broadening incurred by the strong nonlinear interaction between the pump and Stokes pulses via the polarization-mode dispersion and group-velocity dispersion of the fiber. We also investigate the impact of the inter-pulse time-delay on the additional spectra broadening when dual-wavelength pump pulses are used. Exploiting these unique SRS properties of the HBF, we develop a novel Raman continuum source based on an all-fiber dual-wavelength master-oscillator power amplifier that can generate a dip-free spectrum in the 1200-1400-nm spectral range. We finally obtain a broadband continuum having an average power of ~840 mW and a 3-dB bandwidth of ~240 nm centered at 1200-1400 nm, which also represents a good spectral flatness and conversion efficiency. This type of source is very useful and important for optical coherence tomography applications, for example.

Construction and validation of a dose-response curve using the comet assay to determine human radiosensitivity to ionizing radiation.

Individual radiosensitivity is an individual characteristic associated with an increased reaction to ionizing radiation. The purpose of our work is to establish a dose-response curve useful to classify individuals as radiosensitive or radioresistant. Thus, a dose-response curve was constructed by measuring in vitro responses to increasing doses (0 to 8 Gy) of gamma radiation in the comet assay. The obtained curve fit well with a linear equation in the range of 0 to 8 Gy. The overall dose-response curve was constructed for percent DNA in tail, as a measure of the genetic damage induced by irradiation. To probe the goodness of the constructed curve, a validation study was carried out with whole blood from two donors in a blind study. Results show that, for the two applied doses (2 and 6 Gy), the obtained values fit well inside the interval of confidence of the curve. In conclusion, our results demonstrate the usefulness of the comet assay in determining individual responses to defined doses of gamma radiation. The standard dose-response curve constructed may be used to detect individuals departing from reference values.

¿Mejora la liberación posterior ampliada a múltiples niveles la corrección de la curva en la escoliosis idiopática del adolescente? / Can multiple-level posterior release improve curve correction in adolescent idiopathic scoliosis?

Objetivo: Comparar los resultados de la corrección por vía posterior con una construcción híbrida mediante el empleo de una liberación posterior clásica y la liberación posterior ampliada (LPA). Material y métodos: Efectuamos un estudio de cohortes retrospectivo con 46 pacientes diagnosticados de escoliosis idiopática del adolescente (EIA). Se realizó una corrección por vía posterior mediante el empleo de una instrumentación híbrida. En el primer grupo se realizó una liberación posterior estándar (LPE) y en el segundo se realizó una LPA, y se resecaron todos los ligamentos posteriores y se realizó una facetectomía amplia bilateral. Se compararon los resultados de las mediciones en telerradiografías anteroposteriores y laterales preoperatorias, postoperatorias y a los 2 años. Se valoraron los resultados clínicos mediante el cuestionario SRS 22. Resultados: No hubo diferencias en cuanto al sexo, edad, tipo de curva, niveles instrumentados, tiempo quirúrgico o Cobb preoperatorio (LPE: 60°±10°; LPA: 59°±8°) de la curva principal. En el grupo de LPA la corrección obtenida fue significativamente mayor en el postoperatorio (p<0,001) y a los 2 años (p<0,05). La corrección de la curva proximal y lumbar resultó similar en ambos grupos y no se encontraron diferencias significativas. Las complicaciones menores fueron similares en ambos grupos y no existieron complicaciones graves. Conclusión: La LPA a múltiples niveles mejora la corrección de la curva principal en el plano coronal en los pacientes con EIA, sin aumento de la incidencia de complicaciones, además de aumentar la superficie de artrodesis y facilitar la introducción del alambrado (AU)

Purpose: To compare the results of posterior correction using hybrid instrumentation and classical posterior release with those obtained with an extended posterior release. Material and methods: We carried out a retrospective cohort study of 46 patients diagnosed with adolescent idiopathic scoliosis (AIS). A posterior correction was carried out using hybrid instrumentation. In the first group, a standard posterior release (SPR) was performed, whereas in the second an extended release (EPR) was carried out, resecting all posterior ligaments and performing an extended bilateral facetectomy. The results of the measurements were compared using pre-op, post-op and 2-year-follow-up anteroposterior and lateral teleradiographs. Clinical results were evaluated using the SRS 22 questionnaire. Results: There were no differences as regards gender, age, curve type, instrumented levels, OR time or pre-op Cobb's angle (SPR: 60°±10°; EPR: 59°±8°) of the principal curve. In the extended release group the correction obtained was significantly greater at post-op (p<0.001) and at 2 years (p<0.05). Correction of the proximal and lumbar curve was similar in both groups, with no significant differences. Minor complications were similar in both groups, with no serious complications. Conclusion: Multiple-level posterior release improves correction of the principal curve on the coronal plane in patients with AIS, without an increase in the complications rate. The procedure also extends the arthrodesed area and facilitates introduction of the wires (AU)

Intraspecific functional diversity in hosts and its effect on disease risk across a climatic gradient.

The effects of host biodiversity on disease risk may vary greatly depending on host population structure and climatic conditions. Agricultural diseases such as potato late blight, caused by Phytophthora infestans, provide the opportunity to study the effects of intraspecific host diversity that is relatively well-defined in terms of disease resistance phenotypes and may have functional impacts on disease levels. When these systems are present across a climatic gradient, it is also possible to study how season length and conduciveness of the environment to disease may influence the effects of host diversity on disease risk. We developed a simple model of epidemic progress to evaluate the effects on disease risk of season length, environmental disease conduciveness, and host functional divergence for mixtures of a susceptible host and a host with some resistance. Differences in disease levels for the susceptible vs. resistant genotypes shifted over time, with the divergence in disease levels first increasing and then decreasing. Disease reductions from host diversity were greatest for high host divergence and combinations of environmental disease conduciveness and season length that led to moderate disease severity. We also compared the effects of host functional divergence on potato late-blight risk in Ecuador (long seasons), two sites in Peru (intermediate seasons) in El Niño and La Niña years, and the United States (short seasons). There was some evidence for greater disease risk reduction from host diversity where seasons were shorter, probably because of lower regional inoculum loads. There was strong evidence for greater disease reduction when host functional divergence was greater. These results indicate that consideration of season length, environmental conduciveness to disease, and host functional divergence can help to explain the variability in disease response to host diversity.

Gating of two-pore domain K+ channels by extracellular pH.

Potassium channels have a conserved selectivity filter that is important in determining which ions are conducted and at what rate. Although K+ channels of different conductance characteristics are known, they differ more widely in the way their opening and closing, the gating, is governed. TASK and TALK subfamily proteins are two-pore region KCNK K+ channels gated open by extracellular pH. We discuss the mechanism for this gating in terms of electrostatic effects on the pore changing the occupancy and open probability of the channels in a way reminiscent of C-type inactivation gating at the selectivity filter. Essential to this proposed mechanism is the replacement of two highly conserved aspartate residues at the pore mouth by asparagine or histidine residues in the TALK and TASK channels.

Vascular endothelial growth factor plasma levels in patients with systemic lupus erythematosus and primary antiphospholipid syndrome.

The objective of this study was to assess the possible role of vascular endothelial growth factor (VEGF) in the pathogenesis of systemic lupus erythematosus (SLE) and primary antiphospholipid syndrome (PAPS). We studied 28 patients with SLE, 10 patients with PAPS, and 24 healthy controls. VEGF plasma levels were measured by ELISA. Immunolocalization of VEGF was done in renal tissue from SLE patients and cadaveric controls. Our results showed that VEGF plasma levels were increased in SLE patients compared with PAPS and controls. The correlation between clinical manifestations and VEGF levels revealed that SLE patients with renal failure had significantly increased plasma VEGF levels (134.1 + 91.0 pg/ml) compared with SLE patients with normal renal function (42.9 + 19.0 pg/ml), PAPS patients (41.9 + 26.6 pg/ml), and controls (36.2 + 27.0 pg/ml; P < 0.01). Immunostaining showed a strong expression of VEGF in SLE renal tissue samples. Our preliminary results indicate that VEGF is increased in plasma from patients with lupus nephritis and a moderate degree of renal failure and is overexpressed in renal tissue from these patients.

Protective effect of S-adenosyl-l-methionine on liver damage induced by biliary obstruction in rats: a histological, ultrastructural and biochemical approach.

In human and experimental CCl4-liver damage, S-adenosyl-l-methionine-synthetase and/or the intrahepatic content of S-adenosyl-l-methionine, are diminished and in human cirrhosis phospholipid methyltransferase is markedly reduced. Therefore the aim of this study was to investigate the effect of S-adenosyl-l-methionine administration on liver damage induced by 15-day bile duct ligation. Liver damage was analyzed by histological, ultrastructural and biochemical techniques. Biliary obstruction produced an increase in collagen content, dilation of the bile canaliculi and disorganization of mitochondria. These effects were not observed in the bile-duct-ligated group receiving S-adenosyl-l-methionine. Biochemical results showed that bile duct ligation increased serum bilirubins, and alkaline phosphatase and gamma-glutamyl transpeptidase activities. These effects were prevented significantly by S-adenosyl-l-methionine. On the other hand, glycogen content in the liver was depleted while lipid peroxidation was increased by biliary obstruction, S-adenosyl-l-methionine administration prevented these effects. In the bile-duct-ligated group, hepatocyte and erythrocyte plasma membrane Na+/K+ and Ca(2+)-ATPase were lower than in the control group (p < 0.05). Administration of S-adenosyl-l-methionine preserved ATPase activities. The exogenous S-adenosyl-l-methionine supply is probably responsible for restoring transmethylation lost in liver diseases.

Simple determination of ranitidine in dosage forms by in-phase selective AC polarography.

A new AC polarographic method for the determination of pharmaceutical forms of ranitidine is proposed, based on the electroactivity of the ranitidine nitro group. Individual and composite assays as well as recovery studies are described. Results show adequate precision and accuracy. Sample preparation is easy and no excipient separation is required.