945 research outputs found

    Relief of Cervicogenic Headaches after Single-Level and Multilevel Anterior Cervical Diskectomy: A 5-Year Post Hoc Analysis

    Get PDF
    Study Design Prospective study. Objective Because single-level disk arthroplasty or arthrodesis in the lower subaxial spine improves headaches after surgery, we studied whether this effect may be better appreciated after two-level arthroplasty. Methods We performed an independent post hoc analysis of two concurrent prospective randomized investigational device exemption trials for cervical spondylosis, one for single-level treatment and the other for two adjacent-level treatments. Results For the one-level study, baseline mean headache scores significantly improved at 60 months for both the cervical disk arthroplasty (CDA) and anterior cervical diskectomy and fusion (ACDF) groups (p \u3c 0.0001). However, mean improvement in headache scores was not statistically different between the investigational and control groups from 6 months through 60 months. For the two-level study, baseline mean headache scores significantly improved at 60 months for both the CDA and ACDF groups (p \u3c 0.0001). The CDA group demonstrated greater improvement from baseline at all points; this difference was statistically significant at 6, 12, 24, 36, and 48 months but not at 18 and 60 months. Conclusion Both CDA and ACDF at either one or two levels are associated with sustained headache relief from baseline. Patients undergoing two-level arthroplasty had significantly greater improvement in headache at all points except for at 18 and 60 months. This difference in improvement was not observed in patients undergoing single-level arthroplasty. The mechanism of greater headache relief after two-level arthroplasty remains unclear

    Síndrome de intestino corto en niños: actualidades en su diagnóstico y manejo

    Get PDF
    ResumenEl síndrome de intestino corto (SIC) se refiere a la suma de alteraciones funcionales que resultan de una reducción crítica en la longitud del intestino, y que en ausencia de un tratamiento adecuado se manifiestan con diarrea crónica, deshidratación crónica, desnutrición, pérdida de peso, deficiencia de nutrimentos y electrolitos, así como falla para crecer que se presenta con mayor frecuencia durante el periodo neonatal. El objetivo de este artículo es realizar una revisión de la literatura médica sobre la definición, las causas más frecuentes de SIC así como entender la fisiopatología, los factores pronósticos y tratamiento.Se realizó una búsqueda de artículos en PubMed, considerando la información existente en niños con SIC de 20 años hasta la fecha, utilizando las palabras clave “síndrome de intestino corto”. De un total de 784 artículos potenciales, se realizó una selección de 82 artículos donde realizamos la revisión de la literatura médica. Los pacientes con SIC son todo un reto para su tratamiento, por lo que se debe establecer un manejo multidisciplinario enfocado en mantener un soporte nutricional óptimo que cubra las necesidades para crecimiento, desarrollo y asimismo, disminuir al máximo la presencia de complicaciones a corto, mediano y largo plazo. El diagnóstico y manejo de un niño con SIC, implica un equipo de profesionales expertos en el manejo gastroenterológico, pediátrico y nutricional. El pronóstico del niño estará en función al manejo oportuno, así como longitud de la resección intestinal y presencia o no de válvula ileocecal.AbstractShort bowel syndrome (SBS) refers to the sum of the functional alterations that are the result of a critical reduction in the length of the intestine, which in the absence of adequate treatment, presents as chronic diarrhea, chronic dehydration, malnutrition, weight loss, nutriment and electrolyte deficiency, along with a failure to grow that is present with greater frequency during the neonatal period. The aim was to carry out a review of the literature encompassing the definition and the most frequent causes of SBS, together with an understanding of its physiopathology, prognostic factors, and treatment.An Internet search of PubMed articles was carried out for the existing information published over the last 20 years on SBS in children, using the keywords “short bowel syndrome”. From a total of 784 potential articles, 82 articles were chosen for the literature review. The treatment of patients presenting with SBS is quite a challenge and therefore it is necessary to establish multidisciplinary management with a focus on maintaining optimal nutritional support that covers the necessities of growth and development and at the same time provides a maximum reduction of short, medium, and long-term complications. The diagnosis and treatment of a child with SBS require a team of professionals that are experts in gastroenterologic, pediatric, and nutritional management. The outcome for the child will be directly related to opportune management, as well as to the length of the intestinal resection and the presence or absence of the ileocecal valve

    Isolation of a New Mexican Strain of Bacillus subtilis with Antifungal and Antibacterial Activities

    Get PDF
    Although several strains of B. subtilis with antifungal activity have been isolated worldwide, to date there are no published reports regarding the isolation of a native B. subtilis strain from strawberry plants in Mexico. A native bacterium (Bacillus subtilis 21) demonstrated in vitro antagonistic activity against different plant pathogenic fungi. Under greenhouse conditions, it was shown that plants infected with Rhizoctonia solani and Fusarium verticillioides and treated with B. subtilis 21 produced augment in the number of leaves per plant and an increment in the length of healthy leaves in comparison with untreated plants. In addition, B. subtilis 21 showed activity against pathogenic bacteria. Secreted proteins by B. subtilis 21 were studied, detecting the presence of proteases and bacteriocin-like inhibitor substances that could be implicated in its antagonistic activity. Chitinases and zwittermicin production could not be detected. Then, B. subtilis 21 could potentially be used to control phytopathogenic fungi that infect strawberry plants

    GRB 221009A: A light dark matter burst or an extremely bright Inverse Compton component?

    Full text link
    Gamma-ray bursts (GRBs) have been considered as potential very high-energy photon emitters due to the large amount of energy released as well as the strong magnetic fields involved in their jets. However, the detection of TeV photons is not expected from bursts beyond a redshift of z0.1z\gtrsim 0.1 due to their attenuation with the extragalactic background light (EBL). For these reasons, the recent observation of photons with energies of 18 and 251 TeV from GRB 221009A (z=0.151) last October 9th, 2022 has challenged what we know about the TeV-emission mechanisms and the extragalactic background. In order to explain the TeV observations, recent works exploring candidates of dark matter have started to appear. In this paper, we discuss the required conditions and limitations within the most plausible scenario, synchrotron-self Compton (SSC) radiation in the GRB afterglow, to interpret the one 18-TeV photon observation besides the EBL. To avoid the Klein-Nishina effect, we find an improbable value of the microphysical magnetic parameter below 10610^{-6} for a circumburst medium value >1cm3> 1{\rm cm^{-3}} (expected in the collapsar scenario). Therefore, we explore possible scenarios in terms of ALPs and dark photon mechanisms to interpret this highly-energetic photon and we discuss the implications in the GRB energetics. We find that the ALPs and dark photon scenarios can explain the 18 TeV photon but not the 251 TeV photon.Comment: 15 pages, 5 figures, 4 table

    Linfangiectasia intestinal primaria: 20 años de experiencia en el Instituto Nacional de Pediatría

    Get PDF
    ResumenAntecedentesLa linfangiectasia intestinal primaria es una enfermedad congénita rara descrita por Waldmann en 1961, y que es consecuencia de una obstrucción del drenaje linfático del intestino delgado con dilatación secundaria de los vasos linfáticos, que distorsionan la arquitectura de las vellosidades ocasionando pérdida de linfa hacia la luz intestinal,dando como resultado una enteropatía perdedora de proteínas y malabsorción de nutrimentos.ObjetivoDescribir las características clínicas, bioquímicas, radiológicas, endoscópicas e histológicas en niños con linfangiectasia intestinal primaria.MétodoEstudio observacional, descriptivo, transversal y retrospectivo de niños con linfangiectasia intestinal primaria que fueron vistos en el Servicio de Gastroenterología y Nutrición del Instituto Nacional de Pediatría desde el 1 de enero de 1992 al 30 de septiembre de 2012, en donde se revisaron los expedientes clínicos de los niños con este diagnóstico.ResultadosSe encontraron 4 pacientes con linfangiectasia intestinal primaria, 3 de ellos diagnosticados antes de los 3 años; todos se presentaron con diarrea crónica, edema, linfopenia, hipocalcemia, hipoalbuminemia e hipogammaglobulinemia, y en 3 pacientes, con hipocolesterolemia, y con tránsito intestinal, endoscopia y biopsias intestinales características de esta enfermedad.ConclusionesLa linfangiectasia intestinal debe sospecharse ante un cuadro de diarrea crónica, enteropatía perdedora de proteínas, que se acompaña de edema a cualquier nivel, así como hipoalbuminemia, hipocalcemia, linfopenia, hipogammaglobulinemia e hipocolesterolemia como los principales hallazgos bioquímicos de esta entidad. Ante esta enfermedad debe realizarse estudio de serie esofagogastroduodenal con tránsito intestinal y endoscopia con toma de biopsias a nivel de duodeno. El tratamiento incluye dieta y administración periódica de albúmina y gammaglobulina.AbstractBackgroundPrimary intestinal lymphangiectasia is a rare congenital disease described by Waldmann in 1961 that is a consequence of obstruction of the lymphatic drainage of the small bowel with secondary lymph vessel dilation. This distorts the architecture of the villi and causes a leakage of lymph into the intestinal lumen, resulting in protein-losing enteropathy and malabsorption.AimTo describe the clinical, biochemical, radiologic, endoscopic, and histologic characteristics in children with primary intestinal lymphangiectasia.MethodA retrospective observational, descriptive, cross-sectional study was conducted that reviewed the case records of children diagnosed with primary intestinal lymphangiectasia that were seen at the Department of Gastroenterology and Nutrition of the Instituto Nacional de Pediatría within the time frame of January 1, 1992 to September 30, 2012.ResultsFour patients were found that presented with primary intestinal lymphangiectasia. Three of them had been diagnosed before 3 years of age. All the patients presented with chronic diarrhea, edema, lymphopenia, hypocalcemia, and hypogammaglobulinemia, and 3 patients presented with hypocholesterolemia. Bowel transit time, endoscopy, and intestinal biopsies were characteristic of this pathology.ConclusionsIntestinal lymphangiectasia should be suspected when there is a clinical picture of chronic diarrhea and protein-losing enteropathy accompanied with edema at any level, as well as hypoalbuminemia, hypocalcemia, lymphopenia, hypogammaglobulinemia, and hypocholesterolemia, which are the main biochemical findings of this pathology. All children presenting with intestinal lymphangiectasia should undergo an upper gastrointestinal series with bowel transit time and endoscopy with biopsies taken at the level of the duodenum. Treatment includes diet and the periodic administration of albumin and gamma globulin

    Genotoxic and Cytotoxic Studies of Beta-Sitosterol and Pteropodine in Mouse

    Get PDF
    Beta-sitosterol (BS) and pteropodine (PT) are constituents of various plants with pharmacological activities potentially useful to man. The chemicals themselves possess biomedical properties related to the modulation of the immune and the nervous systems, as well as to the inflammatory process. Therefore, safety evaluation of the compounds is necessary in regard to their probable beneficial use in human health. The present study evaluates their genotoxic and cytotoxic potential by determining the capacity of the compounds to induce sister chromatid exchanges (SCE), or to alter cellular proliferation kinetics (CPK) and the mitotic index (MI) in mouse bone marrow cells. Besides, it also determines their capacity to increase the rate of micronucleated polychromatic erythrocytes (MNPE) in peripheral mouse blood, and the relationship polychromatic erythrocytes/normochromatic erythrocytes (PE/NE) as an index of cytotoxicity. For the first assay, four doses of each compound were tested: 200, 400, 600, and 1000 mg/kg in case of BS, and 100, 200, 300, and 600 mg/kg for PT. The results in regard to both agents showed no SCE increase induced by any of the tested doses, as well as no alteration in the CPK, or in the MI. With respect to the second assay, the results obtained with the two agents were also negative for both the MNPE and the PE/NE index along the daily evaluation made for four days. In the present study, the highest tested dose corresponded to 80% of the LD(50) obtained for BS and to 78% in the case of PT. The results obtained establish that the studied agents have neither genotoxic nor cytotoxic effect on the model used, and therefore they encourage studies on their pharmacological properties

    Readiness Potential in Parkinson's Disease: Effects of L-Dopa Therapy and Brain Transplants

    Get PDF
    Accurate local positioning systems usually use a network of anchor nodes at known locations to track mobile nodes based on the measurement of the time of arrival (TOA) at anchor nodes of beacon signals transmitted by the mobile nodes. To localize the mobile node either TOA processing, where the unknown transmit time is estimated along with the node location, or time difference of arrival (TDOA) processing, where the transmit time is eliminated before estimating the node location, can be used. We show that the position error bound of both these formulations are the same by analyzing the Cramér-Rao lower bound. When processing data collected in field trials, however, we observed that the TOA processing yields better localization accuracy, and explain this behavior using differential geometry-based curvature measures that show that the TDOA cost function has greater degree of non-linearity.T. Sathyan, M. Hedley, M. Mallic
    corecore