Evaluación de efectos citotóxicos y genotóxicos con ensayo de micronúcleos en la mucosa bucal de pacientes con aparatología ortodóncica. Revisión de la literatura / Evaluation of cytotoxic and genotoxic effects with micronucleus test in the oral mucosa of patients with orthodontic appliances. Review of the literature

Las maloclusiones representan un problema de salud bucodental, que se resuelven mediante la colocación de aparatología ortodóncica fija (AOF). Esta aparatología provoca corrosión y liberación de iones metálicos por las aleaciones que la constituyen y por el tiempo prolongado del tratamiento. El objetivo de este trabajo fue analizar las alteraciones citotóxicas y genotóxicas de las células de la mucosa oral provocadas por el uso de AOF, reportadas en la literatura y evaluadas con ensayo de micronúcleos (MN); el cual es uno de los ensayos más utilizados para identificar el daño al ácido desoxirribonucleico (ADN). Se realizó una revisión de la literatura de los últimos 10 años, donde se incluye- ron nueve estudios, el 55% de estos mostró evidencia de daño citotóxico y genotóxico posterior a la terapia ortodóncica. El promedio de incremento de MN debido al uso de AOF en estos estudios, fue tres veces mayor con respecto a las células bucales sin trata- miento, este dato es similar a reportes de células orales precancerosas investigadas por otros autores. Además los artículos evaluados, reportaron alteración celular a partir de la primera semana de la colocación de los dispositivos y señalaron que hay una disminu- ción del daño con el tiempo de exposición. En conclusión, el ensayo de MN utilizado en la cavidad bucal demostró ser útil para detectar alteraciones en el ADN debido al uso de AOF. Los datos analizados permiten a los ortodoncistas implementar mejoras en la terapéutica ortodóncica.

Malocclusions represent an oral health problem, which is resolved by the placement of fixed orthodontic appliances (FOA). This orthodontic appliance causes corrosion and release of metal ions due to the alloys they constitute and due to the prolonged time of treatment. The objective of this work was to analyze the cytotoxic and genotoxic altera- tions from oral mucosa cells, caused by the use of FOA, reported in the literature and evaluated with micronucleus (MN) test, which is one of the most widely used tests to identify damage to deoxyribonucleic acid (DNA). A review of the literature of the last 10 years was carried out, where nine studies were included, 55% of these studies showed evidence of cytotoxic and genotoxic damage after orthodontic therapy. The increased average in MN due to the use of FOA in these studies, represent values of approximately three-fold more respect to oral cells without treatment, this data is similar to reports of precancerous oral cells that have been reported by other authors. Besides, the articles analyzed reported cell alterations after the first week of the devices placement and indica- ted a decrease in damage with exposure time. In conclusion, the MN test used in the oral cavity was useful in detecting DNA alterations due to the use of FOA. The data analyzed allow orthodontists to implement improvements in orthodontic therapy.

Consenso chileno para la atención integral de niños y adultos con fibrosis quística

Resumen La Fibrosis Quística (FQ) es la enfermedad hereditaria de pronóstico reservado más frecuente en raza blanca. Desde el año 2003, Chile inicia un Programa Nacional de Fibrosis Quística, de carácter integral, dirigido por la Unidad de Salud Respiratoria del Ministerio de Salud. Hasta la fecha, los principales resultados del Programa registran una significativa mayor sobrevida (promedio 27 años) y una significativa reducción en la edad de diagnóstico de los pacientes ingresados desde 2006 en adelante. El acceso a la canasta GES (Garantías Explícitas en Salud), la implementación del tamizaje neonatal en algunas regiones del país, la organización y la constitución de equipos entrenados en FQ de diversas especialidades, ha contribuido a mejorar los resultados. Si bien las principales manifestaciones son del aparato respiratorio y digestivo, el carácter multisistémico de la FQ obliga a conocer los distintos aspectos involucrados en su manejo, a fin de optimizar los resultados del tratamiento y los recursos invertidos, tanto en el sector público como privado. Este documento es una revisión y actualización sobre los principales aspectos del diagnóstico, seguimiento y tratamiento de las manifestaciones respiratorias y no respiratorias de la FQ.

Cystic Fibrosis (CF) is the most frequent hereditary disease in whites, with a reserved prognosis. Since 2003, Chile began a comprehensive National Cystic Fibrosis Program, directed by the Respiratory Health Unit of the Ministry of Health. To date, the main results of the Program record a significantly longer survival (average 27 years) and a significant reduction in the age of diagnosis of patients admitted from 2006 onwards. Access to Chilean Explicit Health Guarantees, the implementation of neonatal screening in some regions of the country, the organization and setting up of CF-trained teams of various specialties, has contributed to improving results. Although the main manifestations are of the respiratory and digestive system, the multisystemic nature of CF makes it necessary to know the different aspects involved in its management, in order to optimize the results of the treatment and the resources invested, both in the public and private sectors. This document is a review and an update on the main aspects of the diagnosis, monitoring and treatment of the respiratory and non-respiratory manifestations of CF.

Matrix Isolation Spectroscopy and Nuclear Spin Conversion of Propyne Suspended in Solid Parahydrogen.

Parahydrogen (pH2) quantum solids are excellent matrix isolation hosts for studying the rovibrational dynamics and nuclear spin conversion (NSC) kinetics of molecules containing indistinguishable nuclei with nonzero spin. The relatively slow NSC kinetics of propyne (CH3CCH) isolated in solid pH2 is employed as a tool to assign the rovibrational spectrum of propyne in the 600-7000 cm-1 region. Detailed analyses of a variety of parallel (ΔK = 0) and perpendicular (ΔK=±1) bands of propyne indicate that the end-over-end rotation of propyne is quenched, but K rotation of the methyl group around the C3 symmetry axis still persists. However, this single-axis K rotation is significantly hindered for propyne trapped in solid pH2 such that the energies of the K rotational states do not obey simple energy-level expressions. The NSC kinetics of propyne follows first-order reversible kinetics with a 287(7) min effective time constant at 1.7 K. Intensity-intensity correlation plots are used to determine the relative line strengths of individual ortho- and para-propyne rovibrational transitions, enabling an independent estimation of the ground vibrational state effective A″ constant of propyne.

Consenso chileno para la atención integral de niños y adultos con fibrosis quística / Chilean consensus for the integral care of children and adults with cystic fibrosis

Cystic Fibrosis (CF) is the most frequent hereditary disease in whites, with a reserved prognosis. Since 2003, Chile began a comprehensive National Cystic Fibrosis Program, directed by the Respiratory Health Unit of the Ministry of Health. To date, the main results of the Program record a significantly longer survival (average 27 years) and a significant reduction in the age of diagnosis of patients admitted from 2006 onwards. Access to Chilean Explicit Health Guarantees, the implementation of neonatal screening in some regions of the country, the organization and setting up of CF-trained teams of various specialties, has contributed to improving results. Although the main manifestations are of the respiratory and digestive system, the multisystemic nature of CF makes it necessary to know the different aspects involved in its management, in order to optimize the results of the treatment and the resources invested, both in the public and private sectors. This document is a review and an update on the main aspects of the diagnosis, monitoring and treatment of the respiratory and non-respiratory manifestations of CF.

La Fibrosis Quística (FQ) es la enfermedad hereditaria de pronóstico reservado más frecuente en raza blanca. Desde el año 2003, Chile inicia un Programa Nacional de Fibrosis Quística, de carácter integral, dirigido por la Unidad de Salud Respiratoria del Ministerio de Salud. Hasta la fecha, los principales resultados del Programa registran una significativa mayor sobrevida (promedio 27 años) y una significativa reducción en la edad de diagnóstico de los pacientes ingresados desde 2006 en adelante. El acceso a la canasta GES (Garantías Explícitas en Salud), la implementación del tamizaje neonatal en algunas regiones del país, la organización y la constitución de equipos entrenados en FQ de diversas especialidades, ha contribuido a mejorar los resultados. Si bien las principales manifestaciones son del aparato respiratorio y digestivo, el carácter multisistémico de la FQ obliga a conocer los distintos aspectos involucrados en su manejo, a fin de optimizar los resultados del tratamiento y los recursos invertidos, tanto en el sector público como privado. Este documento es una revisión y actualización sobre los principales aspectos del diagnóstico, seguimiento y tratamiento de las manifestaciones respiratorias y no respiratorias de la FQ.

A HElium NanoDroplet Isolation (HENDI) investigation of the weak hydrogen bonding in the propyne dimer (CH3CCH)2.

A HElium Nanodroplet Isolation (HENDI) experiment was performed to explore the absorption spectra of the propyne monomer (CH3CCH), dimer and (CH3CCH)≥3 multimers in the vicinity of the CH stretch region ν1 of the monomer. Ab initio calculations were performed at the MP2 level to document the potential energy surface of the dimer. This provided the necessary parameters to simulate the absorption spectrum of the dimer and thus facilitate the interpretation of the experiment. The central result was to observe three isomers of the dimer, hence reflecting the complexity of the weak CHπ H-bonding when several H-donors are at play.

Predicting in-hospital mortality in older general surgical patients.

Introduction A significant number of emergency general surgical admissions occur in older patients. Clinical decision making in this group is challenging and current risk prediction tools extrapolate data from cohorts of younger patients. This is the first UK study to examine risk factors predicting in-hospital mortality in older acute surgical patients undergoing comprehensive geriatric assessment. Methods This was a prospective study of consecutive patients aged ≥75 years admitted non-electively to general surgery wards between September 2014 and February 2017 who were reviewed by an elderly medicine in-reach service. Results A total of 577 patients were included with a mean age of 82.9 years. There was a female predominance (56%). The majority were living at home alone or with carers (93%) and most were independent in basic activities of daily living (79%). Over two-thirds (69%) were mobile with no walking aids or use of a walking stick and overt here-quarters (79%) had no cognitive impairment. Seventy-seven per cent of patients were managed non-operatively. The in-hospital mortality rate was 6.9%. Female sex (p=0.031), dependence in activities of daily living (p<0.001), cognitive impairment (p<0.001) and incontinence (p<0.001) were predictors of in-hospital mortality. ASA (American Society of Anesthesiologists) grade ≥3 was also associated with increased in-hospital mortality (odds ratio: 5.3, 95% confidence interval: 2.6-10.7). Conclusions Older general surgical patients present a high level of complexity. This study highlights the predictive role of mobility, functional and cognitive impairment when assessing this population. Accurate risk stratification requires global assessment by teams experienced in care of the older patient rather than the traditional focus on co-morbidities.

Score clínico para el descarte de neumonía por Mycoplasma pneumoniae / Clinical score to rule out pneumonia due to Mycoplasma pneumoniae

INTRODUCCIÓN: La prueba de oro para el diagnóstico de la neumonía secundaria a Mycoplama pneumoniae es la detección de IgM en pruebas seriadas, ya que una prueba aislada para IgM tiene una sensibilidad del 31,8%. Al existir un cuadro clínico diferenciable de la neumonía por M. pneumoniae de otras etiologías es posible realizar un score clínico para su diagnóstico temprano. OBJETIVO: Elaboración de un score clínico para el descarte de neumonía secundaria a M. pneumoniae. METODOLOGÍA: Se evaluaron 302 expedientes; población de 0 a 18 años con diagnóstico de neumonía. Se obtuvieron 2 grupos: Mycoplasma positivo y Mycoplasma negativo, y utilizando distintas variables en la historia clínica se elaboró un score clínico. RESULTADOS: Treinta y cuatro casos se clasificaron en Mycoplasma positivo y 268 en Mycoplasma negativo. Las variables relevantes para la elaboración del score fueron edad, días con tos y días con fiebre, con lo que se conformó el score tos, edad, fiebre (TEF). Se asignaron rangos para cada variable y puntos para cada rango. Un valor de igual o mayor a 5 equivale a un score positivo. Se aplicó el score TEF a los 302 casos resultando ahora en 164 casos Mycoplasma positivo y 138 Mycoplasma negativo. Este score resultó en una sensibilidad del 85% y especificidad del 49%. CONCLUSIÓN: El score TEF tuvo mejor sensibilidad que otras herramientas diagnósticas clínicas. Con un valor predictivo negativo del 96% es posible descartar anticipadamente una neumonía por M. pneumoniae. Se requiere realizar un estudio prospectivo para verificar la utilidad de nuestro score

INTRODUCTION: The gold standard for the diagnosis of pneumonia secondary to Mycoplasma pneumoniae is the serial measurement of IgM, since an isolated test for IgM has a poor sensitivity of 31.8%. A pneumonia due to Mycoplasma pneumoniae could be of clinically different origins, thus it is possible to perform a clinical score for its early diagnosis. OBJECTIVE: To develop a clinical score in order to rule out a pneumoniae secondary to Mycoplasma pneumoniae. METHODOLOGY: A total of 302 patients from 0 to 18 years-old, with a diagnosis of pneumonia were evaluated and divided into two groups: Mycoplasma positive and Mycoplasma negative. Using different variables in the medical records a clinical score was calculated. RESULTS: Of the 302 cases studied, 34 were classified as Mycoplasma positive and 268 as Mycoplasma negative. The variables relevant to the calculation of the score were age, days with fever, and days with cough, thus providing the CAF (Cough, Age, Fever) score. Ranges were assigned for each variable and points were given for each range. A value greater than or equal to 5 meant a positive score. The CAF score was applied to the 302 cases, resulting in 164 cases of Mycoplasma positive and 138 cases of Mycoplasma negative. The CAF score had a sensitivity of 85% and specificity of 49%. CONCLUSION: The CAF score had better sensitivity than other clinical diagnostic tools. With a negative predictive value of 96% it is possible to rule out a pneumonia secondary to M. pneumoniae. The study requires a prospective study to verify the usefulness of our score

[Clinical score to rule out pneumonia due to Mycoplasma pneumoniae]. / Score clínico para el descarte de neumonía por Mycoplasma pneumoniae.

INTRODUCTION: The gold standard for the diagnosis of pneumonia secondary to Mycoplasma pneumoniae is the serial measurement of IgM, since an isolated test for IgM has a poor sensitivity of 31.8%. A pneumonia due to Mycoplasma pneumoniae could be of clinically different origins, thus it is possible to perform a clinical score for its early diagnosis. OBJECTIVE: To develop a clinical score in order to rule out a pneumoniae secondary to Mycoplasma pneumoniae. METHODOLOGY: A total of 302 patients from 0 to 18 years-old, with a diagnosis of pneumonia were evaluated and divided into two groups: Mycoplasma positive and Mycoplasma negative. Using different variables in the medical records a clinical score was calculated. RESULTS: Of the 302 cases studied, 34 were classified as Mycoplasma positive and 268 as Mycoplasma negative. The variables relevant to the calculation of the score were age, days with fever, and days with cough, thus providing the CAF (Cough, Age, Fever) score. Ranges were assigned for each variable and points were given for each range. A value greater than or equal to 5 meant a positive score. The CAF score was applied to the 302 cases, resulting in 164 cases of Mycoplasma positive and 138 cases of Mycoplasma negative. The CAF score had a sensitivity of 85% and specificity of 49%. CONCLUSION: The CAF score had better sensitivity than other clinical diagnostic tools. With a negative predictive value of 96% it is possible to rule out a pneumonia secondary to M. pneumoniae. The study requires a prospective study to verify the usefulness of our score.

Respuesta al tratamiento periodontal de diabéticos tipo 2 con mal control metabólico y obesos intolerantes a la glucosa, con periodontitis severa / Impact of the periodontal therapy in both clinical and metabolic parameters in type 2 diabetic and prediabetic obese patients with severe periodontitis

Diabetes Mellitus (DM) es un factor de riesgo para periodontitis, a su vez, el control metabólico de los diabéticos se dificulta por la presencia de la infección periodontal, aumentando el riesgo de complicaciones crónicas y eventualmente, la mortalidad por diabetes. Ambas enfermedades se relacionan porque los mediadores de inflamación generados en la infección periodontal y la translocación de bacterias de la cavidad oral a la circulación sistémica, podrían actuar como agravantes de la insulino resistencia y deteriorar el control glicémico. Es evidente que el tratamiento oportuno de la periodontitis mejoraría la calidad de vida de los diabéticos; ayudándolos a alcanzar y mantener un adecuado control metabólico. El presente estudio evaluó el impacto de un protocolo de terapia periodontal en parámetros clínicos y metabólicos de pacientes DM2 y obesos prediabéticos, con el fin de contribuir a la inclusión de los diabéticos descompensados y prediabéticos en tratamientos periodontales exitosos, sin aumentar su riesgo médico. Se seleccionó a 9 individuos con DM2 descompensados y 7 obesos intolerantes a la glucosa, todos con Periodontitis Crónica Generalizada Severa. Los pacientes fueron sometidos a tratamiento periodontal, sin modificar las indicaciones médicas, de acuerdo a un protocolo diseñado por nosotros. Los diabéticos mostraron una leve disminución en la HbA1c a los 6 meses de realizado el tratamiento periodontal, no se registraron complicaciones, ni perdieron su condición de pacientes ambulatorios. La respuesta al tratamiento periodontal, fue similar en ambos grupos, con mejoría en todos los parámetros clínicos. Aunque los resultados obtenidos no son estadísticamente significativos, son muy promisorios.

Diabetes Mellitus (DM) is a risk factor for periodontitis, at the same time, the metabolic control of diabetic patients gets more difficult due to the presence of periodontal infection, increasing the risk of chronic complications and possibly, death by diabetes. It is recognized that both diseases are related because the inflammation factors generated by the periodontitis as well as the oral cavity bacteria in the systemic circulation, may act as aggravating factor for insulin resistance and worsen the glycemic control. It is clear that an opportune treatment of PD would improve the quality of life and the metabolic control of diabetic patients. The objectives of the current paper are to evaluate the impact of the periodontal therapy in both clinical and metabolic parameters in type 2 diabetic and prediabetic obese patients and to demonstrate that uncontrolled diabetics can be treated successfully, without increasing their medical risk. Nine DM2 and 7 glucose intolerant obese patients were selected. All of them suffering severe chronic periodontitis. All patients were treated following a protocol designed by us and medical indications were not modified. The DM2 patients showed approximately a 1 percent decrease in HbA1C after 6 months of the periodontal treatment. No complication was observed and no patient needed major medical assistance. The response to the periodontal treatment was similar in both groups, with a significant improvement in clinical parameters. Although the decrease in HbA1C was not statistically significant, our results are very promising at the clinical setting.

Evolution of ecotoxicity upon Fenton's oxidation of phenol in water.

This work deals with the evolution of intermediates and ecotoxicity upon Fenton's oxidation of phenol in aqueous solution. The EC50 values of the intermediates identified in the oxidation pathway of phenol have been measured. Some of these compounds, mainly hydroquinone and p-benzoquinone, showed toxicity levels much higher than phenol itself. Depending on the operating conditions, these intermediates could be completely transformed into organic acids, mainly oxalic and formic. Ecotoxicity values substantially lower than those expected from the chemical composition were measured in the reaction samples. This is explained by a reduction of the concentration of aromatic intermediates when the pH was adjusted at 6-8 (according to what is required by the standard bioassay ISO 11348-3). Formation of complexes between hydroquinone and p-benzoquinone at increasing pH can remove from solution those highly toxic intermediates whose very low EC50 values give rise to a high ecotoxicity even at fairly low concentrations. This together with the enhanced decomposition of residual H202 at increasing pH represent important beneficial effects of the neutralization step following Fenton treatment which allow a complementary cleaning of the effluent.

Phenol oxidation by a sequential CWPO-CWAO treatment with a Fe/AC catalyst.

Catalytic wet peroxide oxidation (CWPO) of phenol with a homemade Fe/activated carbon (Fe/AC) catalyst has been studied in a stainless steel fixed-bed reactor at different operating conditions (T=23-100 degrees C, P(T)=1-8atm, W=0-2.5g, and tau=20-320g(CAT)h/g(Phenol)). The results show that, thanks to the incorporation of Fe on the activated carbon, phenol conversion improved dramatically, reaching a 90% at 65 degrees C, 2atm, and 40g(CAT)h/g(Phenol). However, TOC conversion values remain fairly low, (around 5% at 40g(CAT)h/g(Phenol)), and no improvement was obtained with the inclusion of Fe. The presence of Fe seems to promote the nondesirable coupling reactions that take place in CWPO of phenol due to the condensation of the ring intermediates (the primary phenol oxidation products). These condensation products are quite refractory to CWPO at the conditions employed. Taking advantage of the high phenol conversions in CWPO and the high phenol mineralization in CWAO, along with the good stability of the Fe/AC catalyst, a CWPO-CWAO sequential treatment has been successfully performed by using a fixed-bed and trickle-bed reactor in series. A CWPO treatment at ambient conditions followed by a CWAO treatment at mild conditions (100 degrees C and 8atm) is presented as high efficiency process for the decontamination of phenolic wastewaters.

Evolution of toxicity upon wet catalytic oxidation of phenol.

This work reports on the evolution of the toxicity of phenol-containing simulated wastewater upon catalytic wet oxidation with a commercial copper-based catalyst (Engelhard Cu-0203T). The results of the study show that this catalyst enhances detoxification, in addition to its effect on the oxidation rate. The EC50 values of the intermediates identified throughout the oxidation route of phenol have been determined and used to predict the evolution of toxicity upon oxidation. The predicted values have been compared with the ones measured directly from the aqueous solution during the oxidation process. To learn about the evolution of toxicity through out the routes of phenol oxidation, experiments have been performed with simulated wastewaters containing separately phenol, catechol, and hydroquinone as original pollutants. The significant increase of toxicity observed during the early stages of phenol oxidation is not directly related to the development of the brown color that derives mainly from catechol oxidation. This increase of toxicity is caused by the formation of hydroquinone and p-benzoquinone as intermediates, the former showing the highest toxicity. Furthermore, synergistic effects, giving rise to a significant increase of toxicity, have been observed. These effects derive from the interactions among copper leached from the catalyst and catechol, hydroquinone, and p-benzoquinone and demand that close attention be paid to this potential problem in catalytic wet oxidation.

Environmental transformation of the Bilbao estuary, N. Spain: microfaunal and geochemical proxies in the recent sedimentary record.

The distribution and abundance of benthic foraminifera and a range of elements have been analysed in six long cores (up to 10 m long) from the Bilbao estuary, N. Spain, to document environmental transformation of this estuarine ecosystem and to determine sediment contamination levels. Three different environmental zones could be distinguished in the recent sedimentary record based on its microfaunal and geochemical contents. Initially, a pre-industrial zone containing very abundant and diverse foraminiferal assemblages together with baseline metal levels. Secondly, an older industrial zone exhibiting co-existence of abundant and diverse foraminiferal assemblages with high concentrations of metals. Finally, a younger industrial zone with extreme concentrations of metals and barren of indigenous foraminifera. This environmental transformation has been caused by the discharge of untreated domestic and industrial effluents during the last 150 years. The occurrence of foraminifera in the two industrial zones and along the estuary is not related to defined levels of metals, and this seems to confirm oxygen limitation as the key factor to explain complete estuarine defaunation during deposition of the younger industrial zone (period 1950-2000). Effectiveness of current regeneration schemes could be assessed using microfaunal and geochemical proxies as environmental quality indicators.

Single-tube balanced heminested PCR for detecting Mycobacterium tuberculosis in smear-negative samples.

In order to achieve more sensitive and specific results for the rapid diagnosis of tuberculosis, we have developed a new method, named balanced heminested PCR, which avoids the inconvenience of asymmetric amplification and has the advantages of single-tube heminested PCR. This was achieved by replacing the outer primer that participates in both rounds of amplification in the standard heminested technique by another primer containing the sequence of the inner primer attached at its 5' end. When both techniques were tested for the IS6110 target of Mycobacterium tuberculosis complex in 80 smear-negative culture-positive sputum samples and 60 control samples, the results showed 100% specificity for both techniques and sensitivities of 60 and 75% for heminested PCR and balanced heminested PCR, respectively (P = 0.02). In conclusion, the balanced heminested technique shows a higher sensitivity than that of the standard heminested, and it could be applied to any PCR by attaching the inner primer at the 5' end of the opposite outer primer. Thus, the balanced heminested technique provides a target for the inner primer in both strands, avoiding asymmetric amplification and thereby resulting in a more efficient amplification, and, in practice, a higher sensitivity without loss of specificity and with a minimum risk of cross-contamination.

Efectividad de productos sintéticos sobre formas inmaduras de Fasciola Hepática en ratones CD-1 infestados artificialmente

Se realizó un ensayo para evaluar la actividad fasciolicida de cinco productos químicos derivados benzimidazólicos nuevos a 100 y 200 mg/kg de peso por vía oral, y el triclabendazol a 40 y 80 mg/kg de peso en tamizaje primario con formas inmaduras de Fasciola hepática, en ratones invalidos artificialmente. Como criterio de efectividad se analizó el promedio de F. Hepática en el grupo tratado comparado con el control, así como el índice hepático, el grado de lesiones del bazo y las muertes ocurridas en cada grupo. De los compuestos benzimidazólicos demostraron una efectividad no significativa al compararlos con el control infestado y no tratado (71,83 por ciento Beta y AHC-15; 64,79 por ciento AHC-56). El triclabendazol a 80 mg/kg de peso tuvo 100 por ciento de efectividad, mientras que a 40 mg/kg de peso disminuyó a un 53,52 por ciento

Changes in chromosomal localization of heterochromatin-binding proteins during the cell cycle in Drosophila.

We examined the heterochromatic binding of GAGA factor and proliferation disrupter (Prod) proteins during the cell cycle in Drosophila melanogaster and sibling species. GAGA factor binding to the brownDominant AG-rich satellite sequence insertion was seen at metaphase, however, no binding of GAGA factor to AG-rich sequences was observed at interphase in polytene or diploid nuclei. Comparable mitosis-specific binding was found for Prod protein to its target satellite in pericentric heterochromatin. At interphase, these proteins bind numerous dispersed sites in euchromatin, indicating that they move from euchromatin to heterochromatin and back every cell cycle. The presence of Prod in heterochromatin for a longer portion of the cell cycle than GAGA factor suggests that they cycle between euchromatin and heterochromatin independently. We propose that movement of GAGA factor and Prod from high affinity sites in euchromatin occurs upon condensation of metaphase chromosomes. Upon decondensation, GAGA factor and Prod shift from low affinity sites within satellite DNA back to euchromatic sites as a self-assembly process.

Biological characterization of Drosophila Rapgap1, a GTPase activating protein for Rap1.

The activity of Ras family proteins is modulated in vivo by the function of GTPase activating proteins, which increase their intrinsic rate of GTP hydrolysis. We have isolated cDNAs encoding a GAP for the Drosophila Rap1 GTPase. Drosophila Rapgap1 encodes an 850-amino acid protein with a central region that displays substantial sequence similarity to human RapGAP. This domain, when expressed in Escherichia coli, potently stimulates Rap1 GTPase activity in vitro. Unlike Rap1, which is ubiquitously expressed, Rapgap1 expression is highly restricted. Rapgap1 is expressed at high levels in the developing photoreceptor cells and in the optic lobe. Rapgap1 mRNA is also localized in the pole plasm in an oskar-dependent manner. Although mutations that completely abolish Rapgap1 function display no obvious phenotypic abnormalities, overexpression of Rapgap1 induces a rough eye phenotype that is exacerbated by reducing Rap1 gene dosage. Thus, Rapgap1 can function as a negative regulator of Rap1-mediated signaling in vivo.

Characterization of rho GTPase family homologues in Drosophila melanogaster: overexpressing Rho1 in retinal cells causes a late developmental defect.

The rho family of GTPases has been implicated in regulating changes in cell morphology in response to extracellular signals. We have cloned three widely expressed members of this family from Drosophila melanogaster; a rho homologue (Rho1) and two rac homologues (Rac1 and Rac2). Flies harbouring a Rho1 transgene that is specifically expressed in the eye exhibit a dramatic dose dependent disruption of normal eye development. Flies bearing at least two copies of the transgene display a severe rough eye phenotype characterized by missing secondary and tertiary pigment cells, a substantial reduction in the number of photoreceptor cells and a grossly abnormal morphology of the rhabdomeres. Cell fate determination in the imaginal disc occurs normally and abnormalities become manifest late in pupariation, coincident with the phase when the cells undergo major morphological changes. This phenotype is modified by mutations at several other loci that have been implicated in signal transduction, but not by mutations in ras pathway components.

Unilateral renal papillectomy via laser or incisional techniques: chronic functional effects in the dog.

OBJECTIVE: To determine if selective renal papillectomy would impair urinary concentrating ability, thereby decreasing urinary calcium concentration. METHODS: Left papillectomy was performed in dogs using either incisional (n = 6) or Neodymium:yttrium-aluminum-garnet (Nd:YAG) laser (n = 5) techniques. Split renal function studies were then performed four months postoperatively to determine the effect on multiple parameters including inulin and para-aminohippurate (PAH) clearance, free water reabsorption, and calcium concentrations. Partially infarcted kidneys (n = 6) were evaluated in a similar fashion to determine the role of impaired glomerular filtration rate (GFR) in the observed concentrating defect occurring after papillectomy. RESULTS: Papillectomized kidneys demonstrated impaired free water reabsorption, resulting in a decreased urinary osmolality and an increased fractional excretion of water. Osmolar clearance [Na+] and Na+ excretion were unaffected by papillectomy, whereas [Ca++] was significantly reduced. While a slight defect in free water reabsorption existed following partial infarction, urinary osmolality was only minimally decreased, fractional excretion of water was unchanged, and Na+ excretion was decreased. CONCLUSIONS: The concentrating defect induced by papillectomy via either sharp excision or laser ablation is due to loss of medullary tissue and is greater than the defect resulting from impaired GFR, which is presumably due to decreased medullary solute delivery and increased flow of water in remaining nephrons. Since the physiologic consequences of papillectomy (formation of less concentrated urine with decreased [Ca++]) have potential clinical applicability, further study of this concept is warranted.