ABSTRACT
BACKGROUND: Alginates are polysaccharides used in a wide range of industrial applications, with their functional properties depending on their molecular weight. In this study, alginate production and the expression of genes involved in polymerization and depolymerization in batch cultures of Azotobacter vinelandii were evaluated under controlled and noncontrolled oxygen transfer rate (OTR) conditions. RESULTS: Using an oxygen transfer rate (OTR) control system, a constant OTR (20.3 ± 1.3 mmol L 1 h 1 ) was maintained during cell growth and stationary phases. In cultures subjected to a controlled OTR, alginate concentrations were higher (5.5 ± 0.2 g L 1 ) than in cultures under noncontrolled OTR. The molecular weight of alginate decreased from 475 to 325 kDa at the beginning of the growth phase and remained constant until the end of the cultivation period. The expression level of alyA1, which encodes an alginate lyase, was more affected by OTR control than those of other genes involved in alginate biosynthesis. The decrease in alginate molecular weight can be explained by a higher relative expression level of alyA1 under the controlled OTR condition. CONCLUSIONS: This report describes the first time that alginate production and alginate lyase (alyA1) expression levels have been evaluated in A. vinelandii cultures subjected to a controlled OTR. The results show that automatic control of OTR may be a suitable strategy for improving alginate production while maintaining a constant molecular weight.
Subject(s)
Polysaccharide-Lyases/metabolism , Oxygen Transfer , Azotobacter vinelandii/metabolism , Oxygen/metabolism , Gene Expression , Polymerase Chain Reaction , Azotobacter vinelandii/genetics , Alginates/metabolism , Fermentation , Molecular WeightABSTRACT
Resumen Introducción: La hipercolesterolemia familiar homocigótica (HFHo) se caracteriza por niveles muy elevados de cLDL y por enfermedad aterosclerótica temprana. Aunque la frecuencia es baja (1/300.000), las complicaciones son muy severas y pueden ser evitadas. Encontrar y tratar esta población de manera temprana podría reducir la mortalidad. Se describen 36 casos en Colombia, en donde se calcula que haya entre 160 y 200 casos. Resultados: Un total de 36 pacientes con fenotipo sugestivo de HFHo fueron identificados y tratados en un período de observación de cuatro años. La media de edad fue 27 años (24 mujeres). 34 pacientes tuvieron un puntaje según la Red de Clínicas de Lípidos de Holanda (RCLH) mayor de 8 (diagnóstico definitivo) y los restantes 2 tenían puntaje equivalente a diagnóstico probable. Un cuarto de los casos procedían de la costa norte colombiana. En las pruebas genéticas, 14 fueron homocigóticos verdaderos para mutación del gen que codifica para el receptor de LDL (LDLR), 12 heterocigóticos compuestos, 2 heterocigóticos dobles y uno autosómico recesivo (LDLRAP1); 5 pacientes fueron heterocigóticos simples (LDLR) y 2 pacientes no autorizaron la prueba. En los homocigóticos verdaderos, la variante más frecuente encontrada fue la c.11G>A. 14 pacientes cursaron con enfermedad coronaria, 9 con estenosis carotídea, 8 con estenosis aórtica y 2 tuvieron ataques cerebrovasculares (ACV). 34 pacientes recibían estatinas (24 rosuvastatina), 30 recibían ezetimibe, 2 recibían evolocumab y 20 recibían lomitapide (dosis promedio 12,7mg). Ninguno recibió aféresis de cLDL. Los medicamentos, en general, fueron bien tolerados y la reducción promedio de cLDL con la terapia fue de 533,7mg/dl a 245,1mg/dl (54%). Conclusiones: Todos los pacientes recibieron tratamiento hipolipemiante y se encontraron alteraciones genéticas diagnósticas en todos aquellos que autorizaron el examen. Los niveles elevados de cLDL conllevan tanto riesgo que el tratamiento debe establecerse aún sin conocer el diagnóstico genético.
Abstract Background: Homozygous familial hypercholesterolemia (HoFH) is characterized for very high levels of cLDL and early cardiovascular disease. Although incidence is low (1/300 000), complications are very severe and can be avoided. Finding and treating this population promptly could reduce mortality. We describe 36 cases in Colombia, where 160 to 200 cases are expected. Results: 36 patients with phenotype of HoHF were identified and treated in a follow-up of 4 years. The mean age was 27 years (24 women). 34 of them had at least 8 points in the FH Dutch Lipid Clinic Criteria (definitive diagnosis) and two had probable diagnosis. A quarter of the cases came from the Colombian North Coast. In molecular tests, 14 were true homozygous for LDLR, 12 were compound heterozygous for LDLR, 2 double heterozygous and one was autosomal recessive; 5 were heterozygous and 2 patients did not authorized genetic test. In true homozygous subjects, the most frequent variant was c.11G>A. 14 patients had coronary disease, 9 carotid stenosis, 8 aortic stenosis and 2 had stroke. 34 patients were on statins (25 rosuvastatin), 30 were receiving ezetimibe, 2 were receiving a PSCK9 inhibitor (evolocumab) and 20 were on lomitapide with mean doses of 12.7mg. None received lipoprotein apheresis. Medications were very well tolerated. Changes in cLDL after therapy was from 533.7 mg/dL to 245 mg/dL, (54%). Conclusions: Treatment was started in all patients. We found genetic mutations in all patients with genetic tests. The high levels of cLDL mean such a high risk that treatment must be started promptly, even without a genetic test.
Subject(s)
Humans , Male , Female , Adult , Hypercholesterolemia , Alleles , Genetics , Hyperlipoproteinemia Type II , Lipids , Cholesterol, LDL , MutationABSTRACT
Azotobacter vinelandii is a gram-negative soil bacterium that produces two biopolymers of biotechnological interest, alginate and poly(3-hydroxybutyrate), and it has been widely studied because of its capability to fix nitrogen even in the presence of oxygen. This bacterium is characterized by its high respiration rates, which are almost 10-fold higher than those of Escherichia coli and are a disadvantage for fermentation processes. On the other hand, several works have demonstrated that adequate control of the oxygen supply in A. vinelandii cultivations determines the yields and physicochemical characteristics of alginate and poly(3-hydroxybutyrate). Here, we summarize a review of the characteristics of A. vinelandii related to its respiration systems, as well as some of the most important findings on the oxygen consumption rates as a function of the cultivation parameters and biopolymer production.
Subject(s)
Respiration , Biopolymers/biosynthesis , Azotobacter vinelandii/physiology , Polyesters , Alginates , Gram-Negative Bacteria/physiology , Hydroxybutyrates , Nitrogen FixationABSTRACT
Reseña: El propósito de este estudio es evaluar la aplicación clínica e indicación de los criterios apropiados para la ecocardiografía de estrés de acuerdo a la Fundación del Colegio Americano de Cardiología/Sociedad Americana de Ecocardiografía, en la práctica diaria de un centro cardiovascular de referencia. Materiales y métodos: Fueron incluidos los estudios consecutivos realizados entre enero de 2012 y julio de 2013. Los datos fueron revisados, analizados y clasificados por cuatro cardiólogos expertos teniendo en cuenta: la demografía, la especialidad que refiere, la indicación primaria y su clasificación final como apropiados, inapropiados o inciertos. Resultados: Un total de 1.556 estudios fueron incluidos inicialmente, 450 fueron excluidos por estar relacionados con programas de trasplante de órgano sólido y en 170 no se pudo determinar una indicación clara para el estudio. Los 936 estudios restantes (85%) fueron analizados para la determinación de criterios apropiados. De estos 679 (73%) tenían una indicación apropiada, 70 (7%) eran inciertos y 187 (20%) fueron inapropiados. Cuatrocientos veintiocho (46%) fueron referidos por medicina interna, 375 (40%) por cardiología, 51 (5%) por anestesiología y 82 (10%) por medicina general y otras especialidades. Un total de 159 (17%) estudios arrojaron un resultado anormal, todos ellos estaban apropiadamente indicados, ninguno fue anormal en los inapropiadamente indicados. Conclusiones: La revisión de la aplicación de los criterios apropiados para la ecocardiografía de estrés no solo permite una implementación clínica efectiva en un centro cardiovascular de referencia, sino que también estratifica razonablemente la posibilidad de tener un resultado anormal en aquellos con una indicación apropiada. Sin embargo, esto debería validarse extensamente en una cohorte multicéntrica.
Background: The purpose of this study is to evaluate the clinical application and assessment of appropriate criteria for the indication of stress echocardiograms according to the American College of Cardiology Foundation/American Society of Echocardiography in daily clinical practice at a cardiovascular reference center. Materials and methods: All consecutive studies carried out between January 2012 and July 2013 were included. The data was reviewed, analyzed and classified by four expert cardiologists regarding issues such as demography, referred specialty, primary indication and its final classification as appropriate, inappropriate or uncertain. Results: A total of 1,556 studies were initially included, 450 which were excluded as being related to program of solid organ transplantation and 170 as no clear indication of the study could be determined. Therefore, the remaining 936 were analyzed for the evaluation of appropriateness criteria. Of these 679 (73%) had appropriate indication, 70 (7%) were uncertain and 187 (20%) inappropriate. 428 (46%) were referred by internal medicine, 375 (40%) by cardiology, 51 (5%) by anesthesiology and 82 (10%) by general medicine and other specialties. A total of 159 (17%) studies rendered an abnormal result, all of them which were properly indicated, and no one was abnormal in the inappropriately indicated. Conclusions: Reviewing appropriateness criteria for SE not only allows an effective characterization and clinical performance in a single center, but also reasonably stratifies the possibility of having an abnormal result in those with an appropriate indication. However, this should be validated extensively in a multicenter cohort.
Subject(s)
Echocardiography , Cardiology , Diagnosis , IschemiaABSTRACT
We evaluated the combined effect of decreasing the temperature to a mild hypothermia range (34 and 31ºC) and switching to a slowly metabolizable carbon source (glucose substituted by galactose) on the growth and production of a recombinant human tissue plasminogen activator (rh-tPA) by Chinese hamster ovary cells in batch and semi-perfusion cultures. In batch cultures using glucose as a carbon source, decreasing the temperature caused a reduction in cell growth and an increase in specific productivity of rh-tPA of 32 percent at 34ºC and 55 percent at 31ºC, compared to cultures at 37ºC. Similar behaviour was observed in cultures at 34ºC using galactose as a carbon source. Nonetheless, at 31ºC, the specific productivity of rh-tPA strongly decreased (about 58 percent) compared to the culture at 37ºC. In semi-perfusion culture, the highest rh-tPA specific productivity was obtained at 34ºC. Similarly, whether a decrease in the temperature is accompanied of the replacement of glucose by galactose, the rh-tPA specific productivity improved about 112 percent over that obtained in semi-perfusion culture carried out at 37ºC with glucose as the carbon source. A semi-perfusion culture strategy was implemented based on the combined effect of the chosen carbon source and low temperatures, which was a useful approach for enhance the specific productivity of the recombinant protein.
Subject(s)
CHO Cells , Cold Temperature , Galactose , Glutamic Acid , Tissue Plasminogen Activator , Cell Culture Techniques , TemperatureABSTRACT
When assessing a patient with depression it is crucial not to miss a diagnosis of bipolar depression. In this review we suggest that it can be achieved, first, by consistently using standardised diagnostic criteria (e.g. DSM-IV-TR or ICD 10) and, second, by ascertaining the presence of some clinical features. The latter include previous episodes of mood elevation, current or past episodes of psychotic depression, onset of recurrent depressive disorder before the age of 25, a strong family history of mood disorder and suicide, lack of response or wearing off of response to well conducted antidepressant treatment, and an unusually fast response to antidepressants with features of elation. Although more and better research is required to establish the validity, sensitivity, specificity, and predictive value of each one of these features we suggest that from a practical point of view they would increase clinicians awareness of bipolar depression.
Subject(s)
Humans , Bipolar Disorder/diagnosis , Depressive Disorder/diagnosis , Bipolar Disorder/therapy , Depressive Disorder/therapy , Diagnosis, DifferentialABSTRACT
Se expone el aporte conceptual, administrativo y ético de dos personajes claves en la historia de la psiquiatría: William Tuke y John Conolly. Se efectúa un recuento historico y se esbozan elementos para una reflexión sobre la realidad de los enfermos y servicios psiquiátricos en el Chile actual
Subject(s)
Humans , Psychiatry/history , History, 19th Century , EnglandABSTRACT
Este trabajo describe la expresión verbal de hostilidad mediante el método de análisis de contenido de Gottschalk y cols. en 96 mujeres que presentaban el antecedente de intento de suicidio, dividiendo este grupo en mujeres que reiteran una tentativa autolítica (n=56) y las que efectúan el intento por primera vez (n=40). Los resultados muestran que el mayor promedio corresponde a Hostilidad dirigida hacia adentro y el menor a Hostilidad dirigida haca afuera encubierta. Las medias de expresión de hostilidad en los grupos de repetidoras versus no repetidoras no mostraron diferencias significativas. En los análisis ed correlaciones aparece como relevante que en el grupo de las no repetidoras, la Hostilidad hacia afuera manifiesta se correlaciona en forma directa con: no arrepentimiento frente al intento y la Escala de Intención Suicida;...
Subject(s)
Humans , Female , Hostility , Suicide, Attempted , Women , LanguageABSTRACT
El psiquiatra enfrenta diariamente situaciones que demandan una evaluación de riesgo suicida. Algunos trastornos psiquiátricos, esquizofrenia, depresión, abuso de alcohol/sustancias y trastornos de la personalidad, conllevan una mayor vulnerabilidad al suicidio. Otro importante factor de riesgo es el antecedente de conducta suicida previa. Este trabajo aborda la evaluación de la conducta suicida desde las perspectivas clínicas y psicológicas. Su propósito es contribuir a la identificación de grupos de alto riesgo, con fines preventivos y terapéuticos
Subject(s)
Humans , Male , Female , Suicide/psychology , Depressive Disorder/epidemiology , Stress, Psychological/epidemiology , Mental Disorders/epidemiology , Mood Disorders/epidemiology , Psychiatric Status Rating Scales , Risk Factors , Schizophrenia/epidemiology , Self-Injurious Behavior/epidemiology , Suicide, Attempted/psychology , Suicide, Attempted/statistics & numerical dataABSTRACT
Se expone en forma docente la patología conveniente a la luxación congénita de rodilla. Se analizo la experiencia del Hosp. San Juan de Dios