Contaminación de la dentina con diferentes técnicas de secado / Contamination of dentin with different drying techniques

El secado es uno de los factores clave para lograr una adhesión micromecánica exitosa en la dentina con los sistemas adhesivos de grabado independiente. El objetivo de este trabajo fue comparar los residuos remanentes luego de cuatro procedimientos diferentes de secado en preparaciones ex vivo en dentina. Se utilizaron cinco terceros molares ex-vivo, en cada uno de los cuales se realizó una preparación dentinaria en piso y paredes con al menos un socavado. Las unidades experimentales fueron almacenadas en solución fisiológica durante 7 días. Las distintas técnicas de secado (G1- G8) se aplicaron, luego de que las preparaciones fueron tratadas con gel de ácido fosfórico al 37% (Blue Gel etch Megadental) durante 15s y lavadas con jeringa y agua a presión durante 15s (Técnica de Grabado Ácido o TGA), de la siguiente manera: algodón común (Condesa) (G1), papel tisú (Achiss) cortado a mano (G2) y con tijera (G3), esponja (Sharpys) (G4), papel tisú (Simplicity) cortado a mano (G5)(AU)

Hepatocyte growth factor is elevated in amniotic fluid from obese women and regulates placental glucose and fatty acid metabolism.

INTRODUCTION: To evaluate the impact of the pro-inflammatory cytokine hepatocyte growth factor (HGF) on the regulation of glucose and lipid placental metabolism. METHODS: HGF levels were quantified in amniotic fluid and placenta from control and obese women. 2-deoxy-glucose (2-DOG) uptake, glycolysis, fatty acid oxidation (FAO), fatty acid esterification, de novo fatty acid synthesis, triglyceride levels and carnitine palmitoyltransferase activities (CPT) were measured in placental explants upon addition of pathophysiological HGF levels. RESULTS: In obese women, total- and -activated-HGF levels in amniotic fluid were elevated ∼24%, and placental HGF levels were ∼3-fold higher than in control women. At a similar dose to that present in amniotic fluid of obese women, HGF (30 ng/mL) increased Glut-1 levels and 2-DOG uptake by ∼25-30% in placental explants. HGF-mediated effect on 2-DOG uptake was dependent on the activation of phosphatidylinositol 3-kinase signaling pathway. In addition, HGF decreased ∼20% FAO, whereas esterification and de novo fatty acid synthesis increased ∼15% and ∼25% respectively, leading to 2-fold triglyceride accumulation in placental explants. In parallel, HGF reduced CPT-I activity ∼70%. DISCUSSION: HGF is a cytokine elevated in amniotic fluid and placental tissue of obese women, which through its ability to stimulate 2-DOG uptake and metabolism impairs FAO and enhances esterification and de novo fatty acid synthesis, leading to accumulation of placental triglycerides.

Infralimbic cortex controls core body temperature in a histamine dependent manner.

An increase in body temperature accelerates biochemical reactions and behavioral and physiological responses. A mechanism to actively increase body temperature would be beneficial during motivated behaviors. The prefrontal cortex is implicated in organizing motivated behavior; the infralimbic cortex, a subregion of the medial prefrontal cortex, has the necessary connectivity to serve the role of initiating such thermogenic mechanism at the beginning of the appetitive phase of motivated behavior; further, this cortex is active during motivated behavior and its disinhibition produces a marked behavioral and vegetative arousal increase, together with increases in histamine levels. We wanted to explore if this arousal was related to histaminergic activation after pharmacological infralimbic disinhibition and during the appetitive phase of motivated behavior. We measured core temperature and motor activity in response to picrotoxin injection in the infralimbic cortex, as well as during food-related appetitive behavior, evoked by enticing hungry rats with food. Pretreatment with the H1 receptor antagonist pyrilamine decreased thermal response to picrotoxin and enticement and completely blunted motor response to enticement. Motor and temperature responses to enticement were also completely abolished by infralimbic cortex inhibition with muscimol. To assess if this histamine dependent temperature increase was produced by an active sympathetic mediated thermogenic mechanism or was just a consequence of increased locomotor activity, we injected propranolol (i.p.), a ß adrenergic receptor blocker, before picrotoxin injection into the infralimbic cortex. Propranolol reduced the temperature increase without affecting locomotor activity. Altogether, these results suggest that infralimbic activation is necessary for appetitive behavior by inducing a motor and a vegetative arousal increase mediated by central histamine.

Significado de las vivencias de niños y niñas afectados por el VIH/SIDA, adscritos a un centro de atención y apoyo / Meaning of the live experiences of children suffering of HIV/AIDS, care for a support center

Esta investigación de corte cualitativo con diseño fenomenológico, buscó a través de los talleres lúdicos, la observación participante y la entrevista semiestructurada, comprender el significado de las vivencias de niños y niñas de 7 a 16 años de edad afectados por el VIH/SIDA, adscritos a un centro de atención y apoyo para el VIH/SIDA, entendiendo la vivencia como el resultado de la relación del sujeto con los diversos objetos y eventos que constituyen los aspectos dinámicos de su mundo y que componen su historia. Los significados de estos niños/as acerca de la vivencia de estar afectados por el VIH/SIDA giran en torno al señalamiento, la discriminación, el ser portador social del virus, miedo de revelar la condición en la escuela por el rechazo que puede causarles, la no satisfacción de sus demandas ontológicas por su institucionalización y la resignificación de sus vivencias que los lleva a tener conductas preventivas y ser educadores de la enfermedad.

This qualitative research with a phenomenological design, searched throughout playful workshops, partaker observation and semi-structured interview, understand the meaning of the experiences of children from 7 to 16 years old affected by HIV/AIDS, care for a support center for HIV/AIDS. Understanding the experience as the result of the subject's relationship with the different objects and events that constitute the dynamic aspects of their world and that comprise their story. The meanings of these children on the experience of being affected by HIV/AIDS revolve around tagging, discrimination, carrying the virus socially, fear to reveal the condition at school that can cause rejection, the failure to meet their ontological demands for their institutionalization and the significance of their experiences that leads to preventive behaviors and develop educators of the disease.

Decreased mitochondrial fatty acid oxidation in placentas from women with preeclampsia.

Preeclampsia is a leading cause of maternal and fetal morbidity and mortality in high and low-income countries. The aetiology of preeclampsia is multifactorial and remains obscure. Some evidences suggest that altered placental fatty acid oxidation might play a role in the pathogenesis of preeclampsia. To reveal if placental fatty acid oxidation is reduced in preeclampsia, we evaluate the expression levels of enzymes of mitochondrial fatty acid oxidation using quantitative Real-time PCR and the fatty acid oxidation rate in placental explants. We found that long-chain 3-hydroxyacyl-CoA dehydrogenase levels and fatty acid oxidation capacity were significantly reduced in placentas from women with preeclampsia.

Telangiectasia esencial progresiva: una rara entidad / Progressive essential telangiectasia: a rare disorder

La telangiectasia esencial progresiva (TEP) es una entidad infrecuente que afecta preferentemente a mujeres de edad media. Clínicamente se caracteriza por el desarrollo progresivo de vasos telangiectásicos que inicialmente aparecen en la región distal de las extremidades inferiores y posteriormente se extienden de forma ascendente hacia el tronco y los miembros superiores. Describimos un nuevo caso de TEP en una mujer de 53 años. Se realiza diagnóstico diferencial con otras entidades caracterizadas por el desarrollo de múltiples telangiectasias (AU)

Progressive essential telangiectasia (PET) is a rare skin disorder that affects mainly middle-age women. It is clinically characterized by the development of telangiectases which first appear on distal lower extremities and progressively spread to the trunk and upper limbs. We report a new case of PET in a 53-year-old woman. Differential diagnosis should be performed with other diseases characterized by the development of multiple telangiectasias (AU)

Evidence for multiple nitrate uptake systems in the yeast Hansenula polymorpha.

Hansenula polymorpha mutants disrupted in the high-affinity nitrate transporter gene (YNT1) are still able to grow in nitrate. To detect the nitrate transporter(s) responsible for this growth a strain containing disruption of the nitrate assimilation gene cluster and expressing nitrate reductase gene (YNR1) under the control of H. polymorpha MOX1 (methanol oxidase) promoter was used (FM31 strain). In this strain nitrate taken up is transformed into nitrite by nitrate reductase and excreted to the medium where it is easily detected. Nitrate uptake which is neither induced by nitrate nor repressed by reduced nitrogen sources was detected in the FM31 strain. Likewise, nitrate uptake detected in the strain FM31 is independent of both Ynt1p and Yna1p and is not affected by ammonium, glutamine or chlorate. The inhibition of nitrite extrusion by extracellular nitrite suggests that the nitrate uptake system shown in the FM31 strain could also be involved in nitrite uptake.

Cloning, sequencing, and expression of H.a.YNR1 and H.a.YNI1, encoding nitrate and nitrite reductases in the yeast Hansenula anomala.

A single Hansenula anomala genomic DNA fragment containing the genes H.a.YNR1 (yeast nitrate reductase) and H.a.YNI1 (yeast nitrite reductase) encoding nitrate and nitrite reductase, respectively, was isolated from a lambda EMBL3 genomic DNA library. As probe, a 3.2 kb DNA fragment isolated from a lambda gt11 H. anomala genomic DNA library screened with antiserum anti-NR from H. anomala was used. H. a.YNR1 and H.a.YNI1 genes are separated by 473 bp and encode putative proteins of 870 and 1077 amino acids, respectively, with great similarity to nitrate and nitrite reductases from other organisms. Northern blot analysis revealed that both genes are highly expressed in nitrate, very low in nitrate plus ammonium, and no expression was detected in ammonium or nitrogen-free media. Levels of nitrate reductase and nitrite reductase were very low or undetectable by Western blot analysis in nitrogen-free and ammonium media, whereas both proteins were present in nitrate and ammonium plus nitrate media. The nucleotide sequence Accession No. is AF123281.

One-step, PCR-mediated, gene disruption in the yeast Hansenula polymorpha.

Previous evidence based on the experience of our laboratory showed that one-step gene disruption in the yeast Hansenula polymorpha is not straightforward. A systematic study of several factors which could affect gene disruption frequency was carried out. We found that the more critical factor affecting one-step gene disruption in H. polymorpha is the length of the target gene region flanking the marker gene. Target gene regions of about 1 kb flanking the marker gene were necessary to obtain a disruption frequency of about 50%. However, the gene marker, either homologous or heterologous, the locus and the strain examined did not significantly affect the frequency of disruption; the highest disruption frequency obtained for the YNR1 gene was in the strain HMI39, using the Saccharomyces cerevisiae URA3 gene as a marker. Since long regions flanking the gene marker do not allow the easy PCR-mediated strategies, developed for S. cerevisiae, to obtain constructs to disrupt a given gene in H. polymorpha, an alternative PCR strategy was developed.

Absceso cerebeloso por colesteatoma: a propósito de un caso / Braian abcess for cholesteatoma: a propos the a case a purpose

Las infecciones de origen otógeno tales como otitis media, otomastoiditis y colesteatoma pueden complicarse con infecciones a nivel del sistema nervioso central. Se presenta el caso de un escolar de 12 años de edad, con otomastoiditis y colesteatoma del oído derecho, quien desarrolló un absceso cerebeloso, el cual fue diagnosticado por resonancia magnética nuclear. Mediante este estudio se le hizo seguimiento para evaluar respuesta al tratamiento médico y tomar la decisión de tratamiento quirúrgico. Los sígnos y síntomas iniciales fueron inespecíficos, desarrollando posteriormente hipertensión endocraneana y síndrome de lesión de ocupación de espacio de fosa posterior. Se realizó resonancia magnética nuclear (RMN) confirmándose el diagnóstico de hidrocefalia obstructiva y cerebelitis bilateral a predominio derecho. Se procedió a colocar válvula de derivación ventricular peritoneal y antibioticoterapia. A las 4 semanas se realizó RMN de control evidenciándose absceso cerebeloso derecho por lo que se decide practicar exéresis del mismo, de cuyo material extraído se logró aislar Bacteroides fragilis. Evoluciona satisfactoriamente. Posteriormente se realiza resección del colesteatoma. El paciente egresa con parálisis facial periférica posterior a cirugía del colesteatoma. La audiometría revela ausencia total de audición por el oído derecho. El propósito de presentar este caso es resaltar la alta incidencia de complicaciones intracraneales que tienen las infecciones otógenas y la importancia del diagnóstico precoz y tratamiento adecuado de estas afecciones

[Action-oriented participant research as a strategy for training and evaluation in health education]. / La investigación-acción-participante como estrategia para la capacitación y evaluación en educación sanitaria.

In this article we present the results of a study on educational practices at the "Escuela de Malariología y Saneamiento Ambiental 'Dr. Arnoldo Gabaldón'" (EMSA), a pioneering institution in training health personnel, pertaining to the Ministry of Health and Social Assistance in Venezuela. This study was developed as an experiment in action-oriented participant research, i. e. authorities, teachers, and students were committed to an evaluation of the educational practices in which they were involved. The main results of this cooperative inquiry were: a theoretical reconstruction of the models of health education employed by EMSA; a critical analysis of those models; and the design and testing of an alternative model centered on community participation.

Evaluacion de la calidad de los reactivos que se utilizan en la tecnica de contrainmunoelectroforesis para la determinacion de anticuerpos antirrabicos / Evaluation of the quality of the reagents employed in the counterimmunoelectrophoresis technique for the determination of rabies antibodies

En este estudio se comprobo que el Instituto Butantan produce antigenos y sueros indicadores que se pueden utilizar con exito en la prueba de contrainmunoelectroforesis para titular anticuerpos antirrabicos en personas inmunizadas. No se pudieron demostrar diferencias estadisticamente significativas entre los resultados de las pruebas de estandarizacion realizadas en el Instituto Butantan y las pruebas de control de referencia llevadas a cabo en el Centro Panamericano de Zoonosis. Se propone que el Instituto Butantan produzca y distribuya a nivel nacional los reactivos para que los laboratorios de diagnostico apliquen la tecnica de contrainmunoelectroforesis para la determinacion de anticuerpos antirrabicos.

[Quality of the reagents used in counterimmunoelectrophoresis technique for the determination of antirabies antibodies]. / Evaluación de la calidad de los reactivos que se utilizan en la tecnica de contrainmunoelectroforesis para la determinación de anticuerpos antirrábicos.

This study demonstrated that the antigens and indicator sera produced by the Butantan Institute may be employed with success in the counterimmunoelectrophoresis technique for the titration of rabies antibodies in sera from immunized individuals. No statistically significant differences were demonstrated between the results obtained in the standardization tests carried out at the Butantan Institute and the reference control tests performed at the Pan American Zoonoses Center. It is proposed that the Butantan Institute be in charge of the production and distribution of these reagents at the national level.

Binding characteristics of IgA 16.4.12E, a monoclonal antibody with specificity for the nonreducing terminal epitope of alpha-(1----6)-dextrans. Comparisons between IgA hybridoma 16.4.12E and myeloma W3129.

IgA 16.4.12E is a murine monoclonal antibody obtained following immunization with isomaltohexose linked to keyhole limpet hemocyanin. We have studied its interaction with methyl alpha-D-glucopyranoside and its derivatives bearing deoxy or deoxyfluoro groups, and with the methyl alpha-glycosides of a series of isomalto-oligosaccharides, some bearing deoxy or deoxy-fluoro groups at selected positions. From the data it is concluded that the antibody binds optimally to 4 sequential glucopyranosyl residues and that the protein subsite possessing the major affinity binds the terminal, nonreducing glucosyl group of that antigenic epitope. All the hydroxyl groups of that terminal glucosyl group are involved in hydrogen bonding, some in a donating and some in an accepting capacity. In the last part of the paper we report the construction of a possible model of the antibody, derived from its known amino acid sequence and the known crystalline structures of two closely related antibodies. It shows a pronounced cavity in the general immunoglobulin combining area which is flanked by 2 solvent-exposed tryptophanyl residues. A model recently reported for anti-dextran IgA W3129 shows a similar cavity with one such residue. Guided by hydrogen bonds, experimentally deduced from the comparison of the affinities of variously derivatized ligands, we suggest a speculative fitting for the nonreducing terminus of the dextran antigen, in the respective cavities of both IgA 16.4.12E and W3129.

[Hepatic abscess in children: analysis of 20 cases]. / Abscesos hepáticos en niños: análisis de 20 casos.

Between March 1986 and March 1989, 20 children were diagnosed as having liver abscesses at the Pediatric Department of the Central Hospital in Valencia. 10 were amebic and 10 pyogenic abscesses. 85% occurred in children and 15% in infants. 15 of them (75%) were located in the right lobe, 80% of amebic abscesses had positive serological tests. An etiologic agent was found in 50% of the pyogenic abscesses (3: E. coli, 2: S. Aureus). 80 to 90% of patients presented abnormal prothrombin time. Sedimentation rate was very high in both groups, even at the discharge time. Hepatomegaly, fever, anemia and abdominal pain were the main clinical features. The macroscopic aspect of the aspirate was not helpful in the diagnosis. 60% of amebic liver abscesses needed only medical treatment but 80% of pyogenic abscesses deserved medical treatment and needle aspiration.

The involvement of dimethyl sulfoxide in a bacteriotoxic response of the Ames assay tester strains TA98 and TA100.

Dimethyl sulfoxide is a widely accepted and recommended solvent in which to dissolve compounds to be tested for mutagenicity via the Ames Salmonella/mammalian microsome assay. Using tester strains TA98 and TA100, we observed a bacteriotoxic response with various fractions isolated from beer when dissolved in DMSO but not when dissolved in water. Further characterization of the role of solvent in simple model systems consisting of butanol, DMSO and bacteria strongly suggests a chemical reaction occurs between dimethyl sulfoxide and specific chemical constituents of the test substance, nutrient broth, or the Ames bacterial strains. The result of such an interaction could be misinterpreted as a toxic response to the test substance when, in fact, the bacteriotoxicity could be due to another compound, chemically distinct from the test substance.

Isquenia intestinal en la cirugia re / Intestinal ischemia in the repairing surgery of the abdominal aorta

La isquemia intestinal es una complicacion grave de la cirugia reconstructiva de la aorta abdominal, que involucra generalmente el colon izquierdo, mas raramente el intestino delgado o ambos simultaneamente. Es mas frecuente como complicacion de la aneurismectomia. La incidencia de esta complicacion se ve del 0.2 al 10% de los casos. Los autores lal observaron 7 veces en 216 intervenciones de reconstruccion aortica (3.24%). La mortalidad global de la colitis isquemica es del 40%, cuando la isquemia es transmural la mortalidad del 90%. De los 7 casos a los que hacen referencia los autores 5 fallecieron (71,42%). Los autores discuten los distintos factores que pueden condicionar la instalacion de una isquemia intestinal. Se discute la prevencion de esta complicacion por medidas que deben ser tomadas en el pre e intraoperatorio. Se destacan los elementos clinicos que permitem realizar el diagnostico de isquemia constituida, asi como las medidas paraclinicas que la certificaram.