Supra-treatment threshold neonatal jaundice: Incidence in HIV-exposed compared to non-exposed neonates at Queen Elizabeth Central Hospital in Blantyre, Malawi

Introduction Jaundice is the yellowish pigmentation of the skin, sclera, and mucous membranes resulting from bilirubin deposition. Children born to mothers with HIV are more likely to be born premature, with low birth weight, and to become septic—all risk factors for neonatal jaundice. Further, there has been a change in the prevention of mother-to-child transmission (PMTCT) of HIV guidelines from single-dose nevirapine to a six-week course, all of which theoretically put HIV-exposed newborns at greater risk of developing neonatal jaundice. Aim We carried out a study to determine the incidence of severe and clinical neonatal jaundice in HIV-exposed neonates admitted to the Chatinkha Nursery (CN) neonatal unit at Queen Elizabeth Central Hospital (QECH) in Blantyre. Methods Over a period of four weeks, the incidence among non-exposed neonates was also determined for comparison between the two groups of infants. Clinical jaundice was defined as transcutaneous bilirubin levels greater than 5 mg/dL and severe jaundice as bilirubin levels above the age-specific treatment threshold according the QECH guidelines. Case notes of babies admitted were retrieved and information on birth date, gestational age, birth weight, HIV status of mother, type of feeding, mode of delivery, VDRL status of mother, serum bilirubin, duration of stay in CN, and outcome were extracted. Results Of the 149 neonates who were recruited, 17 (11.4%) were HIV-exposed. One (5.88%) of the 17 HIV-exposed and 19 (14.4%) of 132 HIVnon- exposed infants developed severe jaundice requiring therapeutic intervention (p = 0.378). Eight (47%) of the HIV-exposed and 107 (81%) of the non-exposed neonates had clinical jaundice of bilirubin levels greater than 5 mg/dL (p < 0.001). Conclusions The study showed a significant difference in the incidence of clinical jaundice between the HIV-exposed and HIV-non-exposed neonates. Contrary to our hypothesis, however, the incidence was greater in HIVnon- exposed than in HIV-exposed infants.

Epigenetic regulation in neural crest development : role of DNA methyltransferases 3A and 3B

The neural crest is a group of migratory, multipotent stem cells that play a crucial role in many aspects of embryonic development. This uniquely vertebrate cell population forms within the dorsal neural tube but then emigrates out and migrates long distances to different regions of the body. These cells contribute to formation of many structures such as the peripheral nervous system, craniofacial skeleton, and pigmentation of the skin. Why some neural tube cells undergo a change from neural to neural crest cell fate is unknown as is the timing of both onset and cessation of their emigration from the neural tube. In recent years, growing evidence supports an important role for epigenetic regulation as a new mechanism for controlling aspects of neural crest development. In this thesis, I dissect the roles of the de novo DNA methyltransferases (DNMTs) 3A and 3B in neural crest specification, migration and differentiation. First, I show that DNMT3A limits the spatial boundary between neural crest versus neural tube progenitors within the neuroepithelium. DNMT3A promotes neural crest specification by directly mediating repression of neural genes, like Sox2 and Sox3. Its knockdown causes ectopic Sox2 and Sox3 expression at the expense of neural crest territory. Thus, DNMT3A functions as a molecular switch, repressing neural to favor neural crest cell fate. Second, I find that DNMT3B restricts the temporal window during which the neural crest cells emigrate from the dorsal neural tube. Knockdown of DNMT3B causes an excess of neural crest emigration, by extending the time that the neural tube is competent to generate emigrating neural crest cells. In older embryos, this resulted in premature neuronal differentiation. Thus, DNMT3B regulates the duration of neural crest production by the neural tube and the timing of their differentiation. My results in avian embryos suggest that de novo DNA methylation, exerted by both DNMT3A and DNMT3B, plays a dual role in neural crest development, with each individual paralogue apparently functioning during a distinct temporal window. The results suggest that de novo DNA methylation is a critical epigenetic mark used for cell fate restriction of progenitor cells during neural crest cell fate specification. Our discovery provides important insights into the mechanisms that determine whether a cell becomes part of the central nervous system or peripheral cell lineages.

O efeito do peso vivo às 17 semanas de idade de galinhas poedeiras nos parâmetros produtivos e de qualidade do ovo durante a fase de postura

Dissertação de Mestrado em Engenharia Zootécnica/Produção Animal

Evaluación de pollos camperos en producción intensiva y semi-intensiva con suplementación de extracto de quillaja y residuos de hortalizas

En la presente investigación se evaluó: la ganancia diaria de peso, consumo semanal, índice de productividad, mortalidad, conversión alimenticia, costo por kg de carne, pigmentación en tarsos, porcentaje de grasa y el efecto del extracto de quillaja como coccidiostato, bajo dos sistemas de crianza, intensiva y semi-intensiva. El extracto de quillaja fue utilizado al 0,1% de inclusión en el alimento. La investigación se llevó a cabo en la provincia del Azuay, cantón Cuenca, parroquia San Joaquín, sector Balzay Bajo. Se utilizaron 300 pollitos camperos de la estirpe Hubbard variedad redbro S de 1 día de edad. Las aves se distribuyeron de forma aleatoria en un diseño de bloques al azar con 3 tratamientos, cada uno con 5 repeticiones y con 20 pollitos por unidad experimental. Los tratamientos fueron: T1: testigo, aves alojadas en sistema intensivo; T2: aves alojadas en sistema intensivo, más una dieta modificada que consistía en la adición de extracto de quillaja al 0,1%; T3: sistema semi-intensivo con la misma dieta del T2, las aves de este tratamiento a partir del día 28 de edad tuvieron acceso a un área verde delimitada, la cual poseía una mezcla forrajera de raigrás-alfalfa y además se adicionaron a su alimentación residuos de hortalizas propias de la zona. La investigación duró 56 días, no se evidenciaron diferencias significativas en ganancia diaria de peso, índice de productividad, índice de conversión, costo por kg de carne y porcentaje de grasa (p>0,05), mientras que consumo semanal y mortalidad, mostraron diferencias significativas (p<0,05). En las demás variables se evidenció mejor intensidad de pigmentación en T3 (p<0,05), mientras que en la infestación por coccidios no se observó diferencia entre tratamientos (p>0,05), lo que indica que la aplicación de extracto de quillaja tuvo un efecto similar al programa anticoccidial utilizado en T1

Efeito da disponibilidade de alimento no investimento maternal de Volatinia jacarina (Aves : Thraupidae)

Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Biológicas, Departamento de Ecologia, Programa de Pós-Graduação em Ecologia, 2016.

The influence of triiodothyronine (T-3) on the early development of piracanjuba (Brycon orbignyanus)

This paper reports the triiodothyronine's (T-3) effects on the early growth and survival of piracanjuba (Brycon orbignyanus) produced from fertilized eggs hormone exposed The study was carried out in two phases In the first phase, eggs divided in 6 batches were Immersed in T-3 solutions 0 01, 0 05, 0 1, 0 5 ppm, 1 ppm and control (no T-3) After a 15-min immersion, eggs were transferred to incubators where larvae were kept up to 72 h after hatching Larval weight, length and yolk sac volume were determined every 12 h Sixty and 72 h after hatching, larvae exposed to 0 5 ppm T-3 were significantly heavier than the others, and those exposed to 1 ppm T-3 showed the lowest weight The yolk sac absorption was not affected In the second experimental phase, the resulting fry from the first phase were stocked into 3 boxes per treatment (5 larvae L-1) and fed with plankton, fish larvae and feed prepared in the hatchery (48% CP) in the first 3 days, plankton and feed from the 4th to the 10th day and only feed in the next (last) 5 days Fry weight, length and specific growth rate were determined at 1, 5, 10 and 15 days Survival was calculated in the last day In the 15th day, fry length did not differ among treatments but the weight of the control group was higher Higher survival in the T-3-treated groups suggested lower predation among fry The results allowed us to conclude that there was no expressive effect of T-3 on the growth, but it improved the survival of the piracanjuba progeny

Ablação ocular no camarão Macrobrachium rosenbergii (De Man) (Crustacea, Decapoda, Palaemonidae): efeitos sobre a reprodução, pigmentação epidérmica e atividade alimentar

This study analyze the consequences of unilateral and bilateral ablation based on ovigerous percentage, consecutive spawns, and secondary effects of the surgical process in the females of Macrobrachium rosenbergii (De Man, 1879). Two experiments were carried out with four and seven months old females in intermolt stage. Each experiment was comprised of control, unilateral and bilateral ablation. Eyestalk ablation was done with a bistoury with a topic hot cauterization followed by application of antibiotic pomades. The animals were maintained at constant temperature (28 ± 1,05ºC) and photoperiod of 12L: 12D within fibercement boxes with sandy bottom and biological filter. Females were observed once a day during fourteen weeks, registering gonadal condition, ecdysis and presence of spermatophore (mating) and spawning. Unilateral ablation technique is more efficient due to the anticipation of the first spawn, repeatability between spawns, expressive rate of ovigerous females and survival, that favored its applicability. Bilateral eyestalk ablation produced the mortality of ali the females with change in coloration and food activity patterns. These results corroborate other observations on penaeid shrimps. though bilateral ablation on some lobsters was a success. These results showing an interespecific variation and can be used in aquaculture projects.

Biologia reprodutiva da Tainha, Mugil curema valenciennes, 1836 (osteichthyes: mugilidade) nas águas costeiras do Rio Grande do Norte

The marine fish white mullet, Mugil curema Valenciennes, 1836 (Osteichthyes: Mugilidae) exhibits a wide geographical distribution, being common in the Brazilian coast and is an important component of the artisanal fisheries. The objective of this study was to investigate the reproductive biology of M. curema in the coastal waters of Rio Grande do Norte. Fish samples were captured on a monthly basis during August, 2008 to July, 2009. The fish specimens were numbered, weighed, measured, dissected and their gonads were removed, weighed, their sex and gonadal development were identified. The length-weight relationship was determined for males and females. The sex ratio, the size at first gonadal maturation and gonadosomatic index (GSI) were calculated and ovarian development was investigated using macroscopic and histological techniques. The fecundity, spawning type and the reproductive period of the species were determined. A total of 366 specimens (186 males and 180 females) were captured. The sex ratio was 1:1 and the females were heavier than males. The estimated values of the angular coefficient for both sexes suggest that the species has isometric growth. The size at which 50% of the population began the process of maturation was 25.9 cm of total length for grouped sex. The macroscopic characteristics of the ovaries showed four stages of development: immature, maturing, mature and spent. However, the microscopic characteristics of the ovaries showed five stages of development: immature, early maturing, late maturing, mature and spent. The development of oocytes indicated five phases: Chromatin-nucleolus (phase I), initial perinucleolar (phase II), final perinuclear (phase II), formation of vitelline vesicle or yolk (phase III), vitellogenic (phase IV) and complete vitellogenesis (phase V). The species has a prolonged spawning period, with two peaks coinciding with the rainy season.

The Role of the Transcription Factor Ets1 in Melanocyte Development

Melanocytes, pigment-producing cells, derive from the neural crest (NC), a population of pluripotent cells that arise from the dorsal aspect of the neural tube during embryogenesis. Many genes required for melanocyte development were identified using mouse pigmentation mutants. The deletion of the transcription factor Ets1 in mice results in hypopigmentation; nevertheless, the function of Ets1 in melanocyte development is unknown. The goal of the present study was to establish the temporal requirement and role of Ets1 in murine melanocyte development. In the mouse, Ets1 is widely expressed in developing organs and tissues, including the NC. In the chick cranial NC, Ets1 is required for the expression of Sox10, a transcription factor critical for the development of melanocytes, enteric ganglia, and other NC derivatives. Using a combination of immunofluorescence and cell survival assays Ets1 was found to be required between embryonic days 10 and 11, when it regulates NC cell and melanocyte precursor (melanoblast) survival. Given the requirement of Ets1 for Sox10 expression in the chick cranial NC, a potential interaction between these genes was investigated. Using genetic crosses, a synergistic genetic interaction between Ets1 and Sox10 in melanocyte development was found. Since Sox10 is essential for enteric ganglia formation, the importance of Ets1 on gut innervation was also examined. In mice, Ets1 deletion led to decreased gut innervation, which was exacerbated by Sox10 heterozygosity. At the molecular level, Ets1 was found to activate a Sox10 enhancer critical for Sox10 expression in melanoblasts. Furthermore, mutating Ets1 at a site I characterized in the spontaneous variable spotting mouse pigmentation mutant, led to a 2-fold decrease in enhancer activation. Overexpression and knockdown of Ets1 did not affect Sox10 expression; nonetheless, Ets1 knockdown led to a 6-fold upregulation of the transcription factor Sox9, a gene required for melanocyte and chondrocyte development, but which impairs melanocyte development when its expression is prolonged. Together, these results suggest that Ets1 is required early during melanocyte development for NC cell and melanoblast survival, possibly acting upstream of Sox10. The transcription factor Ets1 may also act indirectly in melanocyte fate specification by repressing Sox9 expression, and consequently cartilage fate.

Salmonella Enterica serovar Typhimurium Infection in Mouse Pregnancy

Salmonella are Gram-negative, intracellular food-borne pathogens that cause pregnancy complications. In pregnant mice, Salmonella enterica serovar Typhimurium (S.Tm) infection results in placental bacterial replication, inflammation, necrosis, and fetal loss by unknown mechanisms. Necroptosis, or programmed necrosis mediated by RIPK3 (receptor-interacting protein kinase 3), an inflammatory cell death pathway, is implicated in the pathogenesis of S.Tm in non-pregnant mice. This goal of this thesis was to investigate the role of necroptosis in the pathogenesis of S.Tm infection during mouse pregnancy. I hypothesized that elimination of the key necroptotic cell death protein RIPK3 would decrease placental inflammation and trophoblast cell death, and increase conceptus survival compared to controls. Mice expressing a functional Slc11a1 (encodes the natural resistance-associated macrophage protein 1, NRAMP1) gene with or without RIPK3 function (Ripk3-/-Slc11a1+/+ compared to Slc11a1+/+) were infected with 103 S.Tm by tail vein injection on gestational day (GD) 12. Mice were euthanized on GD 14 (48h post-infection) or GD 15 (72h post-infection) and implantation sites (IS) and maternal serum were harvested for analyses. In nearly all challenged mice (except one outlier), S.Tm were detected in most IS within a litter but there was limited immune cell infiltration, placental damage or cell death in Slc11a1 competent mice regardless of Ripk3 gene deletion. Maternal serum cytokine analyses confirmed lack of maternal immune responses to S.Tm infection. IS amongst the litter of a single dam (Ripk3-/-Slc11a1+/+ at 72h postinfection) displayed heavy but not universal placental S.Tm infection of decidual tissues and spongiotrophoblast, associated with elevated maternal serum pro-inflammatory cytokines. S.Tm infection of the fetal yolk sac (YS) was observed in 54.5% of IS from this dam. YS infection was confirmed in archival samples in mice expressing Ripk3 with intact Slc11a1 and in mice lacking functional Slc11a1. In Slc11a1 incompetent mice, S.Tm were detected in placental labyrinthine trophoblast. Based on the available data, this thesis suggests that Ripk3 and necroptosis have no significant roles in either promotion or prevention of progressive Salmonella infection during mouse pregnancy. It also provides pilot data that NRAMP1 controls placental localization and lethality due to YS infection.

Branqueamento dentário

A estética dentária tem recebido bastante enfoque nos últimos anos, particularmente devido à importância a que a população atribui à aparência estética do sorriso. É, assim, desejado um sorriso o mais branco possível e que de preferência seja fácil de obter, eficaz, rápido, económico e que seja o menos invasivo possível. No entanto, muitos pacientes apresentam frequentemente dentes com cor alterada, comprometendo desta forma a estética do sorriso. O branqueamento dentário é uma técnica não invasiva, conservadora que não altera a forma natural do dente, e que permite alterações estéticas consideráveis. A procura de uma melhoria estética a todos os níveis, leva a que o Branqueamento dentário se apresente hoje como método de eleição para a remoção da pigmentação dentária. Recorre-se assim a substâncias oxidantes, que na maioria dos casos têm origem no Peróxido de Hidrogénio (H2O2). Um dos efeitos secundários ao Branqueamento, prende-se com a sensibilidade dentária, sendo que esta pode originar algum desconforto ou mesmo ser condicionante para a não realização ou término do tratamento. Para se atingir sucesso num tratamento branqueador é da maior importância o diagnóstico preciso da etiologia da alteração de cor, por isso uma anamnese detalhada e um exame clínico e dentário são da maior importância para se poder aconselhar o paciente pelo melhor tratamento a adotar. O objetivo deste trabalho foi avaliar a informação científica disponível sobre as técnicas disponíveis para realizar branqueamento dentário, vantagens e desvantagens de cada técnica, agentes branqueadores utilizados, mecanismos de ação e os seus efeitos adversos. Para tal foi efetuada uma pesquisa nas bases de dados PubMed e B-On de artigos publicados entre 2006-2016 com as seguintes palavras-chave: dental bleaching, teeth whitening, peroxides, branqueamento dentário, clareamento dentário. O branqueamento dentário, apresenta algumas limitações e contra-indicações, assim como vários efeitos adversos, que devem ser do conhecimento do Médico para este poder intervir devidamente. Foi percetível que um tratamento branqueador depende de inúmeros fatores e que a forma de atuação do profissional é tão importante para o sucesso do tratamento como o tipo de agente branqueador utilizado.

Evaluación de tres microdietas en el destete de Lenguado Paralichthys adspersus (Steindachner, 1867) paralichthyidae, en condiciones de laboratorio

El lenguado peruano Paralichthys adspersus es una especie que presenta gran calidad nutricional y alto valor económico, Se distribuye desde Paita (norte de Perú) hasta el golfo de Arauco (Chile). En el Perú el cultivo de lenguado se desarrolla a nivel experimental y comercial (pequeña escala), sin embargo la investigación realizada es escasa. Durante el proceso de producción de semilla, el periodo de destete, etapa durante la cual el alimento vivo es sustituido por microdietas balanceadas, resulta ser un punto crítico debido a la alta mortalidad que genera en comparación a otras etapas del cultivo. El objetivo del presente estudio es evaluar el efecto del uso de 3 microdietas (dos experimentales y una comercial) en el destete de Paralichthys adspersus, evaluando el crecimiento (longitud y peso) y la supervivencia. En el ensayo se utilizó la dieta comercial Otohime, y las experimentales, elaboradas con procesos diferentes, MEM (Micro-Extrusion Marumerization) y PARA (Particle Assisted Rotational Agglomeration) desarrolladas en el Servicio de Investigación Agrícola (ARS) del departamento de Agricultura de los Estados Unidos (USDA) -Fish Technology Center. El ensayo inició con peces de 35 días de edad con un peso seco promedio de 0,96±0,52 mg y una talla promedio de 9,55±0,84 mm, los cuales se distribuyeron en nueve tanques de 150L a razón de 400 individuos T-1. Se seleccionaron al alzar tres tanques por cada tratamiento. Estos se denominaron T1, T2 y T3, en cada uno se utilizó una microdieta (Otohime, MEM y PARA respectivamente) para realizar el destete. Los resultados muestran que para los tratamientos T1, T2 y T3 la longitud promedio final alcanzada fue de 15,9 ± 3,2, 14,3 ± 1,72 y 14,4 ± 2,28 mm y el peso seco promedio alcanzado fue de 8,83 ± 5,37, 5,53 ± 2,85 y 7,10 ± 3,56 mg existiendo diferencias significativas solo entre los tratamientos T1 y T2 (p<0,05). La supervivencia media fue de 18,1, 16,3 y 15,2 % (Tratamientos T1, T2 y T3 respectivamente). Además se evaluó el efecto de las dietas sobre los procesos de pigmentación y metamorfosis, cuantificando para cada caso la cantidad de peces que presentan pigmentación normal y la cantidad de los que alcanzaron a completar la metamorfosis, resultando que no existen diferencias significativas entre los tratamientos (p>0,05).

Evaluación de las propiedades clinimétricas de la escala POSAS y su aplicación en pacientes de la Fundación del Quemado en Bogotá

•Objetivos: Se tradujo, adaptó y evaluaron las propiedades clinimétricas de la escala POSAS en pacientes con cicatrices hipertróficas (CHT) y queloides (CQ) cómo secuelas de quemadura, que fueron manejados con Z plastias en la Fundación del Quemado en Bogotá (Colombia), entre Junio de 2015 a Abril de 2016. •Métodos: Estudio de evaluación de las propiedades clinimétricas de una escala. Se hizo una traducción y adaptación transcultural siguiendo el método de traducción-retrotraducción. Se aplicó el instrumento adaptado a cincuenta y dos pacientes (n=52) antes y después de la intervención quirúrgica. Se evaluó la validez, confiabilidad, sensibilidad al cambio y la utilidad de la escala. •Resultados: Se hallaron diferencias significativas en los puntajes obtenidos del Observador y del Paciente, antes y después de la intervención quirúrgica (p<0.000); a excepción de prurito. La escala POSAS demostró ser altamente confiable para la Escala del Observador y del Paciente (α = 0.912 y 0.765). Hubo alta correlación en las evaluaciones de dos observadores para las variables ordinales de la Escala del Observador (r>0.6). La concordancia entre las evaluaciones de dos observadores para las variables categóricas de la Escala del Paciente fue buena para la evaluación antes de la intervención para pigmentación y relieve (κ>0.61). Se demostró que el instrumento es capaz de detectar cambios clínicos en el tiempo (p<0.0000), a excepción de prurito (p= 0.271). •Conclusiones: La escala POSAS demostró ser un instrumento válido, confiable y útil para evaluar la calidad de la cicatriz en pacientes con CHT y CQ cómo secuelas de quemadura.

Láser Q-Switched en el manejo de ocronosis exógena: revisión sistemática de la literatura

Antecedentes: La ocronosis Exógena (OE) es una enfermedad subdiagnosticada y de difícil manejo (1). El láser Q-Switched (QS) surge como una alternativa para el tratamiento de esta (2). Objetivo: Describir las características de los pacientes, del láser QS y los desenlaces en el tratamiento de OE. Métodos: Se realizó una búsqueda de la literatura en las bases PubMed, Embase, PMC, Scielo, Elselvier, BMJ Case Reports, Journal of Medical Case Reports, Cases Journal e International Medical Case Reports Journal, desde enero del 2000 a marzo del 2016, pacientes con ocronosis exógena, 18 a 70 años, tratados con láser QS. Los artículos fueron evaluados mediante la herramienta de evaluación de validez y valor educativo de reportes de caso descrito por Pierson (3). Resultados: Se encontraron 256 artículos, 63 fueron seleccionados: 28 repetidos y 31 no cumplieron criterios de inclusión. Se escogieron 4 artículos que reportan 12 casos de pacientes con ocronosis exógena diagnosticada mediante estudio histopatológico y tratada con láser QS. Discusión: Hay poca experiencia con el láser QS en OE. En la práctica clínica se usa para tatuajes y patologías pigmentarias dérmicas con resultados satisfactorios. El pigmento dérmico en OE y la corta duración de pulso de láser QS, podrían ser el pilar de tratamiento para OE. Conclusión: El láser QS puede ser útil para el tratamiento en OE, con nivel de evidencia 3 y grado de recomendación D. Se sugiere realizar estudios clínicos con mayor grado de evidencia.

Kinetic and mechanistic studies on unconventional antioxidant activities of natural compounds

In chapter one, the autoxidation kinetics of natural oil substrates, including, triglyceric sunflower oil, olive oil, terpenic squalene, and p-cymene were calibrated through differential oximetry methods. Calibration allows their use as reference oxidizable substrates for further studies, e.g. for quantitative testing of antioxidants under biomimetic settings. Several essential oils samples, of different botanical species or different productions of same species were studied for their antioxidant activity in inhibited autoxidation kinetics. Their antioxidant activities were matched with their composition analyzed by GC-MS. In chapter two, the molecular mechanism of the synergy between the common phenolic antioxidants such as tocopherol and catechols with widespread essential component gamma-terpinene was studied through lipid oxidation kinetics. Wherein, gamma-terpinene was able to disclose the key intermediacy HOO·, which acted as a reducing agent regenerating the phenolic antioxidant. This counterintuitive role of HOO· radicals was further investigated in detail and allowed to rationalize for the first time the purported antioxidant behavior of PDA melanin nanoparticles. It will also open to a deeper understanding of the redox biology of quinones. Regarding melanin, its role is broadly important in living organisms and its control, including its inhibition, is of great importance with several relevant applications ranging from food preservation to control of human skin pigmentation. In chapter three, an oximetry method combined with the traditional UV-Vis spectroscopy was developed to study the tyrosinase inhibition kinetics, which allowed identifying Glabridin (from G. glabra, L.), as one of the most effective natural tyrosinase inhibitors.