Criterios de retorno al trabajo y determinación del valor de vulnerabilidad por Covid-19 / Criteria for returning to work and determination of the vulnerability value for Covid-19

Resumen: Objetivo: Establecer criterios médicos de retorno al trabajo en personal con riesgo de complicaciones por Covid-19. Material y métodos. Se realizó una revisión sistemática para identificar las condiciones y las características clínicas que influyen en el riesgo de desarrollar Covid-19 grave. Resultados: Se ha demostrado incremento del riesgo en obesidad, edad >60 años, diabetes mellitus, hipertensión arterial, enfermedad pulmonar obstructiva crónica, enfermedad cardiovascular, enfermedad renal crónica y cáncer. Solamente en diabetes se ha estudiado si el control previo influye. Se proponen condiciones específicas y el nivel de riesgo epidemiológico para el retorno al trabajo. Conclusiones: El retorno laboral de estos grupos debe priorizarse buscando favorecer el control de la enfermedad, identificando el estado de salud que incrementa el riesgo y protegiendo el derecho al trabajo. Se presentan recomendaciones para guiar la reincorporación al trabajo.

Abstract: Objective: To establish medical criteria for return to work to people with increased risk of severe illness from Covid-19. Materials and methods. We performed a systematic review to identify the conditions and clinical characteristics that influence the risk of developing severe Covid-19. Results: Increased risk has been shown in obesity, age >60 years old, diabetes mellitus, arterial hypertension, chronic obstructive pulmonary disease, cardiovascular disease, chronic kidney disease and cancer. Only in diabetes it has been studied whether prior control influences. Specific medical conditions and epidemiological risk level for return to work are proposed. Conclusions: Return to work of vulnerable groups should be prioritized, seeking to promote disease control, identifying health conditions that increase risk, and protecting the right to work. We present recommendations to guide the return to work.

Desenvolvimento e caracterização de matrizes tridimensionais porosas a base de quitosana, gelatina e dentina em pó para aplicação em endodontia regenerativa / Development and characterization of three-dimensional porous chitosan, gelatin and dentin powder scaffolds for regenerative endodontics

A composição e arquitetura das matrizes desempenham um papel importante na regeneração tecidual, e a interação entre seus componentes pode influenciar no desenvolvimento celular. Assim, o objetivo do presente estudo foi desenvolver e analisar as características morfológicas, físico-químicas, biológicas e antimicrobianas de matrizes reticuladas ou não a base de quitosana, gelatina e dentina em pó. Matrizes sólidas de quitosana pura; quitosana e gelatina reticuladas ou não com genipina; quitosana, gelatina e dentina em pó reticuladas ou não, foram elaboradas através do método de congelamento e liofilização. As características morfológicas das matrizes foram analisadas por microscopia eletrônica de varredura. As características físico-químicas foram analisadas ensaio de degradação, embebição e liberação de proteínas. A citotoxicidade do meio condicionado com as matrizes nas células-tronco da papila dental foi avaliada pelo ensaio de MTT. A citotoxicidade das matrizes foi avaliada pelo ensaio de contato direto. A morfologia e adesão celular nas matrizes foram avaliadas por microscopia eletrônica de varredura e a proliferação celular pelo ensaio de MTT. A diferenciação das células nas matrizes foi avaliada pelo ensaio de vermelho de alizarina. O efeito antimicrobiano das matrizes foi avaliado pelo método de cultura bactéria, e a adesão das bactérias nas matrizes foi observada por microscopia eletrônica de varredura. Os dados obtidos foram comparados com nível de significância de 5%. Assim, todas as matrizes apresentaram estruturas porosas. A reticulação da matriz reduziu a taxa de degradação e embebição. Com exceção da quitosana pura, todas as matrizes liberaram proteínas. A adição de dentina em pó nas matrizes reticuladas compostas por quitosana e gelatina promoveu maior liberação de proteínas, adesão, proliferação e diferenciação celular. Adicionalmente, conferiu-lhe efeito bacteriostático sobre E. faecalis, limitando sua adesão à superfície da matriz. Assim, conclui-se que a matriz reticulada composta por quitosana e gelatina com adição de dentina em pó apresenta características morfológicas, físico-químicas, biológicas e antimicrobianas adequadas para seu potencial emprego na regeneração das estruturas do complexo dentinho-pulpar. Sendo a adição de dentina em pó determinante na melhoria dessas características.

5-Aminolevulinic acid photoactivated over planktonic and biofilm forms of Enterococcus faecalis as a pharmacological therapy alternative

The purpose of the study was to evaluate the antibacterial effect of protoporphyrin IX (PpIX) generated by the exogenous administration of 5-aminolevulinic acid or δ-ALA and activated with an argon laser over a planktonic and biofilm of Enterococcus faecalis (E. faecalis) as a pharmacological therapy alternative. A planktonic strain of E. faecalis was cultured with a solution of ∂-ALA (40 µg/mL)-thioglycolate solution for 13 min, and a biofilm of E. faecalis was cultured in a δ-ALA (80 µg/mL)-thioglycolate solution for 13 min. Then, both were irradiated with an argon laser. Finally, the antibacterial effect was evaluated by counting the CFU in planktonic form, and a LIVE/DEAD viability cell test. The production and accumulation of PpIX from exogenously administered δ-ALA on E. faecalis in planktonic and biofilm forms was confirmed by spectrofluorometry. The irradiation of PpIX with an argon laser produced an antibacterial effect on E. faecalis in planktonic and biofilm form, even without biofilm disruption, at a concentration of 40 µg/mL and 80 µg/mL of δ-ALA, respectively. The exogenous administration of δ-ALA in combination with laser irradiation on planktonic and biofilm forms of E. faecalis produces an effective antibacterial effect as complement or alternative to pharmacological therapies

Assessment of the Performance and Surface Alteration of Two Single-file Systems According to the Number of Uses

Abstract The aim of this study was to assess the performance and surface alteration of two single-file systems according to the number of uses. Ten WaveOne Primary files (25/.08) and ten One Shape NG files (25/.06) were used for instrumentation of mesial root canals of mandibular molars. Each instrument was cleaned and sterilized after the preparation of two root canals and then reused. The time spent for instrumentation of each root canal was recorded and analyzed by using t-test. Microphotographs of the surface of the instruments were taken with a scanning electron microscope at different magnifications (i.e. 18x, 160x, 500x and 1000x) and at a distance of 4 mm from the instrument's tip before being analyzed by four observers. Presence of disruption of cutting edge, crack, craters and unwinding was assessed and submitted to Fisher's exact test. Both systems showed manufacturing defects and cracks. The presence of disruption of cutting edges was major in WaveOne files from the sixth use, whereas One Shape NG files showed more unwinding. Only preparation time using WaveOne files was influenced by the number of uses. One can conclude that WaveOne files had more disruption of cutting edges and took longer time for root canal preparation from the sixth use onwards, whereas the One Shape NG files showed more unwinding at the tenth use.

Influencia de la medicación intracanal con pasta de hidróxido de calcio en la penetración del cemento obturador / obturadorInfluence of intracanal medication with calcium hydroxide paste in the penetration of the shutter cement / Influência da medicação intracanal com pasta de hidróxido de cálcio na infiltração do cimento obturador

La eliminación del hidróxido de calcio en el conducto radicular es determinante para el éxito del tratamiento endodóntico, los remanentes pueden interaccionar negativamente con los selladores endodónticos aumen-tando las filtraciones y disminuyendo la calidad de la obturación. Objetivo: Evaluar el efecto de la medicación intraconducto con pasta de hidróxido de calcio en la penetración del cemento obturador en el interior de los túbulos dentinarios. Materiales y métodos: 20 raíces distales de molares superiores se instrumentaron uti-lizando el Sistema Wave One Large 40/.08. Se dividieron aleatoriamente en dos grupos: uno obturado con técnica de cono único y cemento Ah plus con rodamina-B y otro obturado con la misma técnica y cemento Ah plus con rodamina B, previa colocación por 15 días y remoción mediante recapitulación de la pasta de hidróxido de calcio. Posteriormente los dientes fueron cortados transversalmente y se realizaron fotomicro-grafías del tercio cervical, medio y apical a través de la técnica de microscopia confocal de barrido por láser. La profundidad máxima de penetración fue determinada a través del programa Image J. Resultados: El ce-mento sellador Ah plus presentó menores valores de penetración cuando fue empleada previamente la pasta de hidróxido de calcio como medicación intracanal (p<0,01). El tercio del conducto con mayor penetración fue el tercio cervical seguido por el tercio medio y por último el apical (p<0,01). Conclusión: Los remanentes de hidróxido de calcio disminuyen la penetración del cemento sellador Ah plus en los túbulos dentinarios en todos los tercios del conducto radicular.

The elimination of calcium hydroxide in the root canal is decisive for the success of endodontic treatment, the remnants can interact negatively with endodontic sealants increasing filtrations and decreasing the quality of the seal. Objective: To evaluate the effect of intra-duct medication with calcium hydroxide paste on the pen-etration of the sealing cement inside the dentinal tubules. Materials and methods: 20 distal roots of upper molars were instrumented using the Wave One Large 40 / .08 System. They were randomly divided into two groups: one sealed with a single cone technique and Ah plus cement with rhodamine-B and another sealed with the same technique and Ah plus cement with rhodamine B, previous placement for 15 days and removal by recapping the paste calcium hydroxide. Subsequently, the teeth were cut transversely and photomicro-graphs of the cervical, middle and apical third were performed using the laser scanning confocal microscopy technique. The maximum depth of penetration was determined through the Image J program. Results: The Ah plus sealing cement had lower penetration values when the calcium hydroxide paste was previously used as an intra-channel medication (p <0.01). The third of the duct with the highest penetration was the cervical third followed by the middle third and finally the apical (p <0.01). Conclusion: Remaining calcium hydroxide decreases the penetration of the sealing cement Ah plus in the dentinal tubules in all thirds of the root canal.

A eliminação do hidróxido de cálcio do canal radicular é determinante para o sucesso do tratamento endo-dôntico; os remanescentes podem interagir negativamente com os cimentos endodônticos, aumentando as filtrações e diminuindo a qualidade do selamento. Objetivo: Avaliar o efeito da medicação intracanal com pasta de hidróxido de cálcio na penetração do cimento de selamento no interior dos túbulos dentinários. Materiais e métodos: 20 raízes distais de molares superiores foram instrumentadas usando o sistema Wave One Large 40 /.08. Eles foram divididos aleatoriamente em dois grupos: um selado com técnica de cone único mais cimento Ah plus com rodamina-B e outro selado com a mesma técnica e cimento Ah plus com rodami-na-B, prévia colocação por 15 dias e remoção recolocação da pasta hidróxido de cálcio. Posteriormente, os dentes foram cortados transversalmente e fotomicrografias do terço cervical, médio e apical foram realizadas pela técnica de microscopia confocal de varredura a laser. A profundidade máxima de penetração foi de-terminada pelo programa Image J. Resultados: O cimento selante Ah plus apresentou menores valores de infiltração quando a pasta de hidróxido de cálcio foi utilizada anteriormente como medicamento intracanal (p <0,01). O terço do conduto com maior penetração foi o terço cervical, seguido pelo terço médio e finalmente o apical (p <0,01). Conclusão: O hidróxido de cálcio restante diminui a penetração do cimento selante Ah plus nos túbulos dentinários em todos os terços do canal radicular.

Influencia de la activación ultrasónica del Hipoclorito de Sodio y de la Clorhexidina sobre el biofilm: estudio exvivo / IInfluence of ultrasonic activation of sodium hypochlorite and chlorhexidine on biofilm: ex-vivo study

Objetivo: Determinar la influencia de la activación ultrasónica de dos soluciones irrigadoras sobre biofilm en raíces de piezas dentales recientemente extraídas con diagnóstico de necrosis y periodontitis apical crónica. Materiales y métodos: Se asignaron 8 raíces a cada grupo: NaOCl al 5% (G1) y CHX al 2% (G2). En el G1 se irrigó con 10 ml de NaOCl al 5%, luego se activaron 5 ml de la solución con PUI por 1 minuto, se continuó con EDTA y luego suero fisiológico. Se trabajó de la misma manera con G2, cambiando el irrigante principal. Se realizaron 8 cortes transversales por cada tercio (cervical y medio), se analizaron bajo microscopía óptica. La presencia de biofilm se analizó en el conducto principal, istmos y túbulos dentinarios. Los datos se sometieron al test de Fisher. Resultados: En el tercio cervical solo hubo diferencia estadística al comparar la limpieza en los túbulos dentinarios, ya que el 12,5% de las muestras del G1 presenta biofilm remanente comparado con el 50% correspondiente al G2. En el tercio medio, hubo más muestras de G2 con biofilm en los conductos principales e istmos, representada por el 75% y 60% respectivamente, y solo el 37,5% de las muestras de G1 mostraron resultado positivo al analizar los túbulos dentinarios. Conclusiones: El hipoclorito de sodio al 5% es más eficiente que la clorhexidina al 2% para eliminar el biofilm, porque deja más limpio el tercio medio. Ambas soluciones tienen un omportamiento similar en el tercio cervical de las muestras. (AU)

Objective: To determine the influence of ultrasonic activation of two irrigant solu-tions on biofilm in the roots of freshly extracted teeth diagnosed with necrosis and chronic apical periodontitis. Mate-rials and methods: Eight roots were assigned to each group: 5% NaOCl (G1) and 2% CHX (G2), both activated ultra-sonically. In G1 irrigation was performed with 10ml of 5% NaOCl, then 5ml were activated with PUI for 1 minute, and EDTA and saline were used next. The same procedure was performed with G2, changing the main irrigant. Eight cross sections were produced for each third (cervical and middle), which were analyzed using optical microscopy. The biofilm presence was analyzed in the main canal, isthmus and dentinal tubules. The data was subjected to the Fisher test. Results: In the cervical third, there was only a statistical difference when comparing the cleanness of the dentinal tubules, with 12.5% of the G1 samples displaying remnant biofilm, compared to 50% in G2. In the middle third, a greater number of G2 samples were found with biofilm on the main canals and isthmus (75% and 60%, respectively) and only 37.5% of the G1 samples tested positive when the dentinal tubules were analyzed. Conclusions: 5% sodium hypochlorite is more efficient than 2% chlorhexidine in eliminating biofilm, leaving the middle third cleaner. In the samples, both irri-gant solutions performed similarly in the cervical third. (AU)

Evaluation of the waveone gold and one shape new generation in reducing enterococcus faecalis from root canal

Abstract The aim of this study was to evaluate the WaveOne Gold and One Shape New Generation systems regarding the bacterial removal from root canals infected with Enterococcus faecalis by comparing them to the conventional WaveOne and One Shape systems. Forty-eight distobuccal root canals of maxillary molars sterilized with ethylene oxide were infected with E. faecalis for 21 days, and then root canal initial bacterial sample was collected with paper cones and plated on M-enterococcus agar. The specimens were randomly divided into 4 groups according to the instrumentation: WaveOne Gold, One Shape New Generation, WaveOne and One Shape. After instrumentation, samples were collected with use of scraping and paper cones at immediate and 7 days after instrumentation. The bacterial reduction was calculated and then made intragroup analysis by Friedman test and intergroup analysis by Kruskal-Wallis with Dunn's post-hoc test, all at 5% significance. All techniques significantly reduced the number of bacteria in the root canal (p<0.05). WaveOne Gold and One Shape New Generation promoted higher bacterial reduction than WaveOne and One Shape systems (p<0.05), but no significant difference was found between WaveOne Gold and One Shape New Generation or between WaveOne and One Shape (p>0.05). Novel single-file systems promote better bacterial removal than the conventional single-file systems.

Resumo A proposta deste estudo foi avaliar os sistemas WaveOne Gold e One Shape New Generation em relação à remoção bacteriana de canais infectados com Enterococcus faecalis, comparando-os com seus sistemas convencionais WaveOne e One Shape. Quarenta e oito canais disto vestibulares de molares superiores esterilizados em óxido de etileno foram contaminados com E. faecalis por 21 dias, e então acoleta bacteriana inicial foi feita com cone de papel e plaqueadas em M-enterococcus agar. Os espécimes foram aleatoriamente divididos em quarto grupos de acordo com a instrumentação: WaveOne Gold, One Shape New Generation, WaveOne e One Shape. Após instrumentação, amostras foram coletadas utilizando limagem e cones de papel imediatamente e 7 dias após o preparo. A redução bacteriana foi calculada e então feita análise intra grupos com teste de Friedman, e entre grupos utilizando Kruskal-Wallis e teste de Dunn, todos a 5% de significância. Todas as técnicas reduziram significantemente o número de bactérias do canal radicular (p<0.05). WaveOne Gold e One Shape New Generation promoveram maior redução bacteriana que WaveOne e One Shape (p<0.05), mas nenhuma diferença significante foi encontrada entre WaveOne Gold e One Shape New Generation ou entre WaveOne e One Shape (p>0.05). Novos sistemas de lima-única promovem melhor remoção bacteriana que seus sistemas convencionais.

Immunohistological study of the effect of vascular Endothelial Growth Factor on the angiogenesis of mature root canals in rat molars

Abstract Tissue bioengineering has been applied to Endodontics to seek a more biological treatment. The presence of blood vessels is crucial for cell nutrition during tissue formation. Objective This study analysed the application of vascular endothelial growth factor (VEGF) in the angiogenesis of mature root canals. Material and methods Upper first molars of twelve 13-week old Wistar male rats were used. The root pulp of the mesiobuccal canal was removed and the root canal instrumented with K-files up to size #25. Periapical bleeding was induced into the root canal by introducing a #15 K-file beyond the apex. The teeth on the right side of the arch were filled up with blood clot (G1), whereas those on the left side were filled up with blood clot plus 50 ng/ml of VEGF (G2). Teeth were sealed with light-curing glass-ionomer cement and the animals were sacrificed after 60 days. The maxilla was dissected and fixed before obtaining serial sections for histological processing with haematoxylin-eosin (HE) and immunohistochemical factor-VIII. Immunohistochemical labelling was evaluated using scores for statistical analysis. Results Immunohistological analysis demonstrated the presence of angiogenesis in both groups, but with higher angiogenic maturation in G2 during the experimental period (p<0.05). HE staining showed connective tissue with absence of odontoblasts in all specimens. Conclusions It can be concluded that it is possible to obtain angiogenesis in mature root canals with or without the use of VEGF, although the latter tends to accelerate blood vessel formation.

Instrument Design May Influence Bacterial Reduction During Root Canal Preparation

Abstract The aim of this study was to evaluate the bacterial reduction promoted by ProTaper Next and Twisted File by comparing to ProTaper Universal and manual technique. Sixty distobuccal root canals of maxillary molars sterilized with ethylene oxide were contaminated with Enterococcus faecalis broth culture. After incubation for 21 days, bacterial samples were collected and cultured on m-Enterococcus agar plates. The root canals were divided into 4 groups, according to the system used for instrumentation: ProTaper Next, Twisted File, ProTaper Universal, and crown down manual technique. Other 8 uncontaminated root canals were control asepsis. Bacterial samples were collected immediately and 7 days after instrumentation. The bacterial reduction was calculated and then made intragroup analysis by paired t-test and intergroup analysis by ANOVA and Tukey tests, all at 5% significance. All techniques significantly reduced the bacterial number in the root canal (p<0.05). ProTaper Next and Twisted File resulted in more bacterial reduction than ProTaper Universal and manual technique (p<0.05). ProTaper Next and Twisted File were similar (p>0.05). It can be concluded that ProTaper Next and Twisted File promote a higher bacterial reduction than Protaper Universal and manual technique.

Resumo A proposta deste estudo foi avaliar a redução bacteriana promovida pelos sistemas ProTaper Next e Twisted File comparando-os ao sistema ProTaper Universal e técnica manual. Sessenta raízes disto vestibulares de molares superiores esterilizadas com óxido de etileno foram contaminadas com Enterococcus faecalis. Após incubação por 21 dias, amostras foram coletas e cultivadas em m-Enterococcus agar. Os canais foram divididos em 4 grupos de acordo com o sistema de instrumentação: ProTaper Next, Twisted File, ProTaper Universal, e técnica manual crown-down. Outros 8 canais não contaminados foram utilizados como controle de assepsia. Amostra bacteriana foi coletada imediatamente após o prepare e aos 7 dias. A redução bacteriana foi calculada, e então feita a análise intergrupos utilizando teste t-pareado, e análise entre grupos utilizando os testes ANOVA e Tukey, todos com 5% de significância. Todas as técnicas reduziram significantemente o número de bactérias no canal radicular (p<0.05). ProTaper Next e Twisted File resultaram em maior redução bacteriana que ProTaper Universal e técnica manual (p<0.05). ProTaper Next e Twisted File foram semelhantes (p>0.05). Pode-se concluir que ProTaper Next e Twisted File promovem maior redução bacteriana que Protaper Universal e técnica manual.

Evaluation of decellularized matrix and ß-tricalcium phosphate as biomaterials for bone neoformation: in vivo study / Evaluación de la matriz descelularizada y ß-fosfato tricálcico como biomateriales para neoformación ósea: estudio in vivo

The aim of this study was to evaluate histologically the effect of two biomaterials, a biomaterial derived from porcine Urinary submucosa Bladder Matrix (UBM) and beta-TriCalcium Phosphate (ß-TCP), on bone defects. Twenty male New Zealand rabbits were used; the models were divided in two groups: the UBM group; the ß-TCP group, and a Negative Control (NC) group. Five-mm defects were created in the femur of each model and then the different biomaterials were set in place depending on each group. At 4 and 8 weeks, the animals in the models were sacrificed and samples of the defect site were collected to perform a Hematoxylin and Eosin stain (H&E). Histologically, ß-TCP group at 4 and 8 weeks presented neoformation of bone-like and cartilage-like tissue, with the presence of inflammatory infiltrate; at 4 and 8 weeks, the UBM group presented neoformation of bone-like and cartilage-like tissue with a low presence of inflammatory infiltrate, and the NC group presented the formation of connective tissue and, in a low proportion, neoformation of bone tissue and cartilage. Both biomaterials, UBM and ß-TCP, exhibited the capacity to promote bone neoformation; however, the UBM-based biomaterial produced a better-organized tissue with a lower inflammatory response compared with the ß-TCP group.

El objetivo de este estudio fue evaluar histológicamente el efecto de dos biomateriales: derivado de matriz de submucosa de vejiga urinaria porcina (UBM) y b-fosfato tricálcico (ß-TCP) en defectos óseos. Veinte conejos macho de raza Nueva Zelanda fueron empleados para este estudio; los modelos fueron divididos en dos grupos: UBM, ß-TCP y un grupo control negativo. Se crearon defectos de 5 mm en el fémur de cada uno de los modelos y posteriormente se colocó el biomaterial correspondiente de acuerdo a cada uno de los grupos. A las 4 y 8 semanas los modelos fueron sacrificados y se tomaron muestras del sitio del defecto óseo para realizar una tinción de Hematoxilina y Eosina. Histológicamente el grupo de ß-TCP tanto a las 4 como a las 8 semanas mostró neoformación de tejido óseo y tejido cartilaginoso con presencia de infiltrado inflamatorio; el grupo de UBM a las 4 y 8 semanas presentó neoformación de tejido óseo, tejido cartilaginoso y un bajo infiltrado inflamatorio; el grupo control negativo presentó formación de tejido conectivo y en baja proporción neoformación de tejido óseo y cartílago. Ambos biomateriales, UBM y ß-TCP mostraron la capacidad de promover la neoformación de tejido óseo; sin embargo, el biomaterial basado en UBM produjo un tejido mejor organizado y un menor infiltrado inflamatorio en comparación con el ß-TCP.

Regeneración in vitro de plantas de piña ( Ananas comosus ) ecotipo amazónico Gobernadora / In vitro regeneration of Amazonian pineapple ( Ananas comosus ) plants ecotype Gobernadora

Resumen En Venezuela existen cultivares y ecotipos de piña (A. comosus) de importancia local, entre ellos los amazónicos, cultivados principalmente por los aborígenes Piaroa. Ellos siembran los propágulos lo cual restringe la disponibilidad de material para el cultivo a gran escala. Se abordó la limitación recurriendo al cultivo de tejidos vegetales para la propagación in vitro de plantas de piña, ecotipo amazónico Gobernadora, mediante embriogénesis somática (ES) y organogénesis adventicia (OA). El material vegetal empleado correspondió a secciones basales e intermedias de hojas. Sólo las secciones de base foliar (SBF) fueron morfogénicamente inducidas. El mayor número de vitroplantas (1,58 plantas/explante) se obtuvo del callo embriogénico inducido en medio MS con Picloram 10 mg.L-1 + Tidiazuron 2 mg.L-1, transferido a MS sin hormonas. En el proceso organogénico, se obtuvo el mayor número de plantas/explante (5) por vía directa en MS con ácido naftalenoacético 5 mg.L-1 + bencilaminopurina 0,25 mg.L-1, transferido a MS. Siendo este último el mejor sistema de cultivo in vitro por su productividad y por ser una ruta que minimiza la variación somaclonal.

Abstract There are a number of pineapple (Ananas comosus) cultivars and ecotypes of local commercial importance in Venezuela, among them the Amazonian ones, cultivated mainly by the aboriginal Piaroa, are of relevance. They sow the propagules, which restricts the availability of material for large-scale cultivation. This limitation was approached by plant tissue culture for in vitro propagation of Amazonian pineapple plants, Gobernadora ecotype, through somatic embryogenesis (ES) and adventitious organogenesis (OA). Basal and intermediate sections of leaves were tested. Only the leaf base sections (FBS) were morphogenically induced. The highest number of vitroplants (1.58 plants / explant) was obtained from the embryogenic callus induced in MS medium with Picloram 10 mg.L-1 + Thidiazuron 2 mg.L-1, transferred to MS medium without hormones. In the organogenic process, the highest number of plants / explants (5) was obtained directly in MS with naphthaleneacetic acid 5 mg.L-1 + benzylaminopurine 0.25 mg.L-1, transferred to MS. The latter being the best in vitro culture system due to its productivity and for being a method that minimizes somaclonal variation.

Parámetros biológicos básicos para la conservación de Pseudocurimata lineopunctata (Characiformes, Curimatidae) en el Río Anchicayá, Valle del Cauca, Colombia / Basic biological parameters for Pseudocurimata lineopunctata (Characiformes, Curimatidae) conservation in the Anchicayá River of the Cauca Valley, Colombia

ResumenPseudocurimata lineopunctata representa un importante aporte nutricional para las comunidades locales en Colombia y Ecuador. A pesar que su captura anual es baja (590 kg/año), no hay restricciones sobre el tamaño mínimo, y esta especie está catalogada como vulnerable en riesgo de extinción moderada por la Corporación Autónoma Regional del Valle del Cauca (Colombia). Para apoyar los programas de conservación, se requiere de datos biológicos de las especie. Por lo tanto, los objetivos de este estudio fueron describir la proporción de sexos, la distribución, el tamaño en relación al peso, las fases macroscópicas de la madurez reproductiva, fecundidad y talla de primera madurez sexual para P. lineopunctata. Las muestras de peces fueron capturados con redes por nueve meses (Febrero-Octubre) en 2007. La longitud total (Lt) de los peces capturados varió entre 10.7 y 16.5 cm, con peso total (Pt) entre 25.0 y 67.5 g. Las hembras representaron el 52.6 % del grupo de muestra mientras que los machos el 47.4 %, y se observaron diferencias en la proporción de sexos en relación con el tamaño del pez. Durante todos los meses muestreados se capturaron ejemplares en estado de madurez avanzado. Con base en el análisis de los índices gonadosómatico, (IGS), gonádico (IG) y de condición (K), se postula que habría dos máximos de desove, uno de junio-julio y otro en septiembre-octubre. La talla de primera madurez sexual para las hembras fue determinada en 9.2 cm y para los machos en 10.1 cm de Lt. La fecundidad absoluta fue estimada en 3 598 ovocitos/♀, con una fecundidad relativa de 84 ovocitos/g♀. Se hace necesario realizar investigaciones adicionales que aumenten la información sobre la reproducción de esta especie, con la finalidad de apoyar futuros programas de repoblamiento.

Abstract:Pseudocurimata lineopunctata represents an important nutritional source for local human communities in Colombia and Ecuador. Although the yearly catch of this fish is low (590 kg/year), there are no restrictions on minimum size, and this species is categorized as vulnerable with moderate extinction risk by the Regional Autonomous Corporation of the Cauca Valley (Colombia). To support conservation programs, biological data of the target species are required. Therefore, the aims of this study were to describe the sex ratio, distribution, size to weight ratio, macroscopic stages of reproductive maturity, fecundity, and size at first sexual maturity for P. lineopunctata. For this, fish samples were captured with nets over nine months (February-October) in 2007. The total length (Lt) of the captured fish ranged between 10.7 and 16.5 cm, with total weight (Pt) between 25.0 and 67.5 g. Females represented 52.6 % of the sample group while males represented 47.4 %, and differences in sex ratio were observed in relation to fish size. For all sampled months, the fish captured showed an advanced maturity state. Based on analyses of the gonadosomatic index (IGS), gonadic index (IG), and Fulton's condition factor (K), and two spawning peaks were determined, one in June-July, and the other in September-October. The size at first sexual maturity was 9.2 cm for females and 10.1 cm for males. Absolute fecundity was estimated as 3 598 oocytes/ g♀. It is necessary to carry out additional investigations on the reproduction of this species, to support future repopulation programs. Rev. Biol. Trop. 65 (1): 239-253. Epub 2017 March 01.

Parámetros biológicos de Pseudocurimata boulengeri (Characiformes: Curimatidae) en el embalse Chongón, Ecuador / Biological parameters of Pseudocurimata boulengeri (Characiformes: Curimatidae) inhabiting the Chongón dam, Ecuador

ResumenPseudocurimata boulengeri, es una especie endémica del Ecuador, que da sustento a un importante grupo de familias de pescadores. Los antecedentes biológicos para esta especie corresponden a reportes en los sistemas loticos de la Provincia de los Ríos, se desconoce si estos parámetros siguen igual tendencia en un sistema lentico. En este trabajo se describe la proporción de sexo, la relación talla peso total, el desarrollo gonadal, la época de desove y el tamaño de primera madurez reproductiva de P. boulengeri, en el embalse de Chongón, Ecuador. Se capturaron peces con redes de enmalle (2.5") entre 2003 y 2009. La longitud total (Lt) de los peces capturados fue de 10.5 a 36.0 cm, el desove ocurre de noviembre a marzo y el tamaño de primera madurez para las hembras se estimó en 17.96 cm (Lt) y para los machos en 20.05 cm (Lt). La proporción de machos y hembras entre mayo y octubre, se ajusta a lo esperado (1:1), mientras que entre noviembre y abril, la proporción de hembras fue mayor que los machos, situación que coincide con la época de desove. Las características limnéticas y productivas del embalse, harían que esta especie pueda disponer de una mayor cantidad de alimento y un ambiente más favorable que le permitiría tener una postura más extendida en el año.

AbstractPseudocurimata boulengeri is an endemic species of Ecuador, which sustains a large group of fisher families. The biological data of this species correspond to reports from lotic systems of Los Ríos province; nevertheless, their trend in a lentic system is not yet known. This paper describes the sex ratio, length-weight relationship, gonad development, spawning season and size at reproductive maturity of P. boulengeri, inhabiting the lentic system of Chongón dam, Ecuador. Fish were caught between 2003 and 2009 using gill nets (2.5"). The total length (Lt) of caught specimens ranged from 10.5 to 35.5 cm, spawning occurred between the months of October and March, and size at first maturity for females was estimated at 17.9 cm (Lt) and 20.0 cm (Lt) for males. Between May and October male and female ratios were as expected (1:1), whereas for May, November and April, females ratios were higher than males, situation that coincided with the spawning season. The limnetic conditions and high production characteristics of Chongón dam, have promoted the availability of a great amount of food for this species, which may have allowed P. boulengeri to have a more extended reproductive season in this favorable environment.

Caracterización morfométrica de la gallina de cuello desnudo (Gallus domesticus nudicollis) en la región ch’ortí de Chiquimula, Guatemala / Morphometric characterization of chickens naked neck (Gallus domesticus nudicollis) in the ch’ortí, region, Guatemala

Se caracterizaron morfométrica, faneróptica y morfológicamente a gallinas y gallos de cuello desnudo (324 hembras, 60 machos) en los cuatro municipios de la región ch’ortí de Chiquimula. Las variables evaluadas fueron 18 cuantitativas para la hembra y 16 para el macho, nueve cualitativas y ocho índices zoométricos. El análisis de las variables zoométricas se realizó a través del procedimiento análisis univariado, con medidas de tendencia central y medidas de dispersión, y para analizar la proporcionalidad y armonía entre las diversas regiones corporales mediante la correlación de Pearson. Los resultados principales son: peso de 1.84 kg/hembra y 2.29 kg/macho; alzada 27.84 cm/hembra y 32.51 cm/macho; metatarso 10.25 cm/hembra y 11.76 cm/macho; ambos tienen más alzada que longitud, inclinados hacia adelante; en cuanto a sus perímetros, el abdominal es el mayor y curvado característica de las gallinas ponedoras y una grupa alargada con dorso plano. Sus índices corporales son aves alargadas, con capacidad reproductiva (índice pélvico 71.82%) y poca formación de músculo para la producción de carne (índice compacidad 6.80%/hembra y 7.03%/macho), cabeza alargada, tórax elíptico y miembros fuertes y altos. Las características morfológicas y fanerópticas describen un ave de piel blanca, metatarso amarillo, plumas en garganta, cresta simple con barbilla y orejuelas, los colores de pluma son la combinación de marrón, negro, gris y blanco, el color de la cáscara varia del blanco al marrón claro y con una armonización corporal hasta del 61% lo que le da una homogeneidad medianamente aceptable a la morfoestructura de la gallina.

Hens and roosters naked neck (324 females and 60 males) were characterized morphological and phenotypically in four villages of the ch’ortí area in the province of Chiquimula. Variables evaluated were 18 quantitative for females and 16 for males, nine qualitative and eight zoometrics ranges. The zoometric variables analyzed were made according to the univariate analysis procedure with measurements of central tendency and dispersion measurements to analyze the proportion and harmony between the different corporeal areas we used the Pearson correlation. In the results weight of 1.84 kg/female and 2.29 kg/male; raised 27.84 cm/female and 32.51cm/male; metatarsal 10.25 cm/female and 11.76 cm/male; the hen has more height than length, raised in the front, concerning to the perimeters, the abdominal is the biggest and curved, which is characteristic in lay eggs hens with flat dorsal. Corporeal indices, they are elongated birds, reproductive capability (pelvic index 71.82%) and less muscles developed to produce meat as food for humans (compactness index 6.80% female and 7.03% male), elongated head, elliptical thorax and long and strong extremities. Phenotypically and morphologically characteristics describe a bird with white skin, yellow metatarsus, feathering on the throat, simple crest, chin and earlobes, the feathering colors are a combination of brown, black, grey, and white, and the colors of the egg shell are from white to light brown, and also has a good corporal harmony up to 61%, which brings an acceptable mild homogeneity comparable to the structure of a hen.

Chemical treatment of the intra-canal dentin surface: a new approach to modify dentin hydrophobicity

Objective: This study evaluated the hydrophobicity of dentin surfaces that were modified through chemical silanization with octadecyltrichlorosilane (OTS). Material and Methods: An in vitro experimental study was performed using 40 human permanent incisors that were divided into the following two groups: non-silanized and silanized. The specimens were pretreated and chemically modified with OTS. After the chemical modification, the dentin hydrophobicity was examined using a water contact angle measurement (WCA). The effectiveness of the modification of hydrophobicity was verified by the fluid permeability test (FPT). Results and Conclusions: Statistically significant differences were found in the values of WCA and FPT between the two groups. After silanization, the hydrophobic intraradicular dentin surface exhibited in vitro properties that limit fluid penetration into the sealed root canal. This chemical treatment is a new approach for improving the sealing of the root canal system.

Propuesta de un nuevo puntaje para optimizar estimados ecográficos de peso fetal: estudio piloto / New score to optimize ultrasound fetal weight estimation: a pilot study

Introducción: La estimación del peso fetal es importante para las decisionesobstétricas; la precisión de los estimados ecográficos no ha sido estudiada. Objetivos: Determinar la precisión del estimado ecográfico del peso fetal mediante un puntaje basado en parámetros clínicos, ecográficos y maternos. Diseño: Estudio de tipo transversal. Lugar: Hospital Nacional Guillermo Almenara Irigoyen, Lima, Perú. Participantes: 130 gestantes y sus fetos. Intervenciones: Se consignó datos clínicos, ecográficos y maternos. Se procedió a dicotomizar los aciertosentre menor o igual a mas o menos10 por ciento (acertadas) y mayor a mas o menos 10 por ciento (erradas) del peso real. Se analizó las variables clínicas, ecográficas y maternas mediante el uso de las curvas ROC, para identificar aquellas que tuvieron más influencia en la precisión ecográfica. Con las variables identificadas, se procedió al desarrollo de un modelo de regresión logística, para establecer un puntaje que estimara la probabilidad devariación, teniendo como punto de corte mas o menos 10 por ciento del peso real. Principales medidas de resultados: Precisión de un puntaje que relaciona la edad gestacional con la circunferencia abdominal y el diámetro biparietal del feto, el ponderado clínico y el peso materno. Resultados: El nuevo puntaje tuvo un buena capacidad de discriminación de las ecografías, según su variación a mas o menos 10 por ciento del peso real (área bajo la curva ROC: 0,76 p menor que 0,001). Según los puntajes obtenidos, se obtuvo tres grupos: rendimiento alto 20 por ciento, rendimiento convencional 44,4 por ciento y rendimiento bajo 71,2 por ciento. Conclusiones: El nuevo puntaje propuesto tiene la capacidad de estimar la probabilidad de variación de los estimados ecográficos mayores al mas o menos 10 por ciento del pesoreal, conformando tres grupos de rendimiento: alto, convencional y bajo.

Introduction: Fetal weight estimation is important for obstetrical decisions;accuracy of ultrasound fetal weight estimations has not been studied. Objective: To determine ultrasound fetal weight estimations precision by developing a score based on clinical, ultrasound and maternal parameters. Design: Cross sectional study. Setting: Guillermo Almenara Irigoyen National Hospital, Lima, Peru. Participants: 130 pregnant women and their fetuses. Interventions: Clinical, ultrasound and maternal data were collected. We dichotomized predictions as actual birth weight less or equal to mor or less 10 per cent (correct) and more than more or less 10 per cent(erroneous). We analyzed clinical, ultrasonographic and maternal variables using ROC curves in order to identify those with more influence in ultrasound accuracy. With such identified variables we developed a logistic regression model to establish a score that would estimate the probability of variation, having a per cent 10 per cent of real fetal birth weight cut point. Main outcome measures: Precision ofa score that relates gestational age and both fetal abdominal circumference andbiparietal diameter, clinical fetal weight estimation and maternal weight. Results: The resulting score had a good capacity of discrimination of ultrasonographic fetal weight estimations according to their variation to more or less 10 per cent of real birth weight (area under the curve ROC: 0,76 p minor that 0,001). Three groups resulted: high performance 20 per cent, conventional performance 44,4 per cent, and low performance 71,2 per cent. Conclusions: The new score proposed estimates the probability of variation of fetal weight above mroe or less 10 per cent of real birth weight, with three groups of performance: high, conventional and low.

Inhibición del desarrollo embrionario por la 5Ó-Noretisterona / Embryo development inhibition by 5Ó-Norethisterone

Introducción. La 5Ó-Noretisterona (5Ó-NET) es un metabolito sintético que tiene alta afinidad por el receptor de progesterona e inhibe la acción de este esteroide natural. En conejas gestantes se demostró que la administración de este compuesto durante los primeros días post-coito inhibe tanto la implantación del ovocito como la actividad del Factor de Embarazo Temprano (FET), dicho factor es producido por el ovocito una vez que se ha llevado a cabo la fertilización. Sin embargo, en éstos trabajos no desmuestran si este compuesto ejerce acciones deletéreas sobre el ovocito en desarrollo, previas a la implantación. Objetivo. Analizar el efecto in vitro e in vivo de 5Ó-NET sobre el desarrollo del ovocito desde la etapa post-fertilización hasta la formación de la mórula. Material y métodos. Los gametos fueron obtenidos de ratones hembras de la cepa Balb/C y de machos C57BL/6J. La fertilización se llevó a cabo tanto in vitro como in vivo utilizando técnicas previamente descritas, con algunas modificaicones. Una vez que se observó la formación de los cuerpos polares, se inició la administración de 5Ó-NET a diferentes dosis al medio de cultivo y se incubaron a 37ºC, 5 por ciento CO2 y 95 por ciento aire. Los cambios en la estructura y morfología fueron analizados a diferentes tiempos de incubación por microscopio de luz (400x). Un total de 153 ovocitos fueron analizados en el modelo in vivo y de 142 en los experimentos in vitro. En ambos casos el análisis estadístico se hizo mediante la prueba de x2 con Ó=0.05. Resultados. El análisis estadístico en ambos modelos muestra que la presencia de 5Ó-NET en el medio de cultivo ejerce efectos deletéreos sobre el desarrollo y morfología de los ovocitos fertilizados, reflejándose en la destrucción de los blastómeros y la aparición de granulaciones en su interior

Reducción del contenido de fibra cruda en pasta de cártamo (Carthamus tinctorius L) y su posible utilización en la alimentación humana / Reduction of crude fibre content in sofflower meal (Carthamus tinctorius L) and the feasibility of using in human food

El objetivo del trabajo fue reducir el contenido de fibra cruda (FC) y cuantificar el contenido de compuestos fenólicos (CF) e inhibidores de tripsina (IT) en pasta de cártamo (PC) para plantear su posible utilización en la alimentación humana. A la PC se le efectuó una molienda en licuadora y en molino de martillos, posteriormente se clasificó por tamaño de partícula y se comparó con la PC(23,3 por ciento de PC, 22,4 por ciento de proteína y 1,75 por ciento de CF) y sus respectivas fracciones. La molienda en molino de martillos resultó más efectiva ya que en la fracción de finos (60,5 por ciento) el contenido de PC se redujo en un 36,3 por ciento, la proteína y los CF se concentraron en 39,3 y 50,3 por ciento, respectivamente. La prueba de IR resultó negativa. La molienda y tamizado resultó ser un método sencillo y económico de separación de fibra en la PC, que permite concentrar proteína y obtener un adecuado rendimiento de material, características por las cuales es posible plantear su utilización en la alimentación humana, en niveles de incorporación no elevados

Estudio de hiperbilirrubinemia en el Hospital Cantonal de Yaruquí

El presente trabajo es un estudio retrospectivo de hiperbilirrubinemia que va desde 1994 (mes en el que a través de la autogestión se obtiene el equipo de fototerapia para el hospital). De los resultados obtenidos se concluye que la mayoría de pacientes atendidos pertenecen al sitio donde se halla ubicado el hsopital, en cuanto al sexo no hay mayor diferencia. La hiperbilirrubinemia se presenta con mayor frecuencia en primigestas y multíparas, no así en Gran multíparas. Clínicamente se determinó la gravedad de la ictericia por zonas y horas de vida en que apareció. De los diagnósticos obtenidos se puede ver que la hiperbilirrubinemia se presentó en recién nacidos a término con peso adecuado para la edad gestacional...