ABSTRACT Appendicitis is the most frequent surgical disease in childhood, but it is very uncommon in the neonatal period. In this period of life, a delay in diagnosis (frequently due to the rareness of this pathology and lack of clinical suspicion) and consequently in therapeutic approach, frequently results in appendicular perforation and a subsequently poor evolution of this pathology. We present the case of a neonate with a history of Down’s syndrome and Fallot’s tetralogy. Due to her basal cardiopathy, she required surgical intervention to create a systemic-pulmonary fistula, as a temporary bridge until definitive cardiac surgery could be performed. In the postoperative period of this surgery she presented fever, acute abdomen and abdominal radiography compatible with pneumoperitoneum. An emergency laparotomy was performed, which revealed peritonitis secondary to a cecal gangrenous appendix with perforation in its middle third. Neonatal appendicitis is usually associated with diseases such as cystic fibrosis, necrotizing enterocolitis, or Hirschsprung’s disease, as in the case of our patient. In neonates with acute abdomen and presence of pneumoperitoneum, appendicitis must be part of the differential diagnosis and requires urgent surgical intervention. Despite this, it presents a high rate of morbidity and mortality. Once the definitive diagnosis is made, any basal pathology that justifies its presence should be discarded.

RESUMEN La apendicitis es la entidad quirúrgica más frecuente en la infancia, pero es poco habitual en el periodo neonatal. A esta edad, su retraso diagnóstico (habitual dada la rareza de esta patología y la falta de sospecha clínica) y consecuentemente terapéutico, hace frecuente la perforación apendicular y la mala evolución posterior de esta patología. Presentamos el caso de un neonato con antecedentes de síndrome de Down y tetralogía de Fallot. Debido a su cardiopatía basal, precisó una intervención quirúrgica para realizar la creación de una fístula sistémico-pulmonar, como puente temporal hasta la cirugía cardíaca definitiva. En el postoperatorio de esta intervención presentó fiebre, abdomen agudo y radiografía abdominal compatible con la presencia de neumoperitoneo. Se realizó una laparotomía urgente que evidenció una peritonitis secundaria a un apéndice cecal gangrenoso con perforación en su tercio medio. La apendicitis neonatal suele presentarse asociada a enfermedades como la fibrosis quística, la enterocolitis necrotizante, o la enfermedad de Hirschsprung, como fue el caso de nuestra paciente. La apendicitis debe formar parte del diagnóstico diferencial en los neonatos con un abdomen agudo y presencia de neumoperitoneo, ya que precisa intervención quirúrgica urgente, a pesar de lo cual presenta una alta tasa de morbimortalidad. Una vez realizado el diagnóstico definitivo, debería descartase la presencia de cualquier patología basal que justificara su presencia.

Abstract: This study analyses cost stickiness under the dilemma between current profitability and future sales increase. When activity decreases firms are faced to keep profitability adjusting resources, while they should also consider long term consequences and keep slack resources which allow building firms capacities to adapt to external challenges and take advantage of future opportunities. We find empirical evidence that changes in current firm profitability and one year ahead sales increase significantly influence resource adjustment in periods when sales decrease. We find a significant moderating effect of changes in profitability, as well as a significant stressing effect of one year ahead sales increase, on cost stickiness.

Resumen: Este estudio analiza la histéresis de los costes bajo el dilema de conseguir una rentabilidad inmediata o futuros incrementos de ventas. Cuando la actividad disminuye las empresas se enfrentan al dilema de mantener la rentabilidad recortando gastos, pero tienen que considerar también las consecuencias a largo plazo de mantener capacidad sobrante o recursos de holgura que les permitan construir capacidades para adaptarse a los desafíos que les plantea el entorno, así como afrontar con ventaja las oportunidades futuras. En este trabajo encontramos evidencia empírica de que los cambios en la rentabilidad presente, así como los aumentos futuros en las ventas influencian significativamente el ajuste de recursos de las empresas en los períodos en los que disminuyen las ventas. Encontramos un efecto moderador de los cambios en la rentabilidad presente, así como un efecto acentuador de los aumentos futuros en las ventas, en la histéresis de los costes.

Currently, the effects of climate change lead to widespread processes of soil degradation in cattle regions, with serious environmental, social and economic consequences. This have especially significant in the karst regions of western Cuba, which coincides with the areas of highest agricultural production, population density and the most important water supply basins of several provinces. Based on researches carried out for more than three decades in reference livestock farms, and through a combination of qualitative and quantitative data, this article exposes the effects of intensive anthropogenesis and climate change on the spatial - temporal evolution of soil properties. Among them, the reduction of organic matter content, pH increase, compaction values with apparent density thresholds higher than 1.34 Mg.m-3, reinforcement of karstic-erosive processes, salinization, and others that coexist zonally and spatially in an essentially superficial domain (A + B0-50 cm), with a marked tendency to increase. These results should be interpreted as an indispensable basis for the design of mitigation and adaptation strategies with an agro-ecological approach in regions of Cuba

Actualmente, los efectos del cambio climático conducen a procesos generalizados de degradación de suelos en regiones ganaderas, con graves consecuencias ambientales, sociales y económicas. Esto tiene especial significación en las regiones cársicas del Occidente de Cuba, que coincide con las zonas de mayor producción agrícola, densidad de población y con las cuencas de abastecimiento de agua más importantes de varias provincias. A partir de investigaciones realizadas por más de tres décadas en establecimientos ganaderos de referencia, y mediante la combinación de datos cualitativos y cuantitativos, este artículo expone los efectos de la antropogénesis intensiva y el cambio climático en la evolución espacio - temporal de las propiedades de los suelos. Entre ellos, la disminución del contenido de materia orgánica, aumento del pH, valores de compactación con umbrales de densidad aparente superiores a 1.34 Mg.m-3, reforzamiento de los procesos cársico - erosivos, salinización, y otros que coexisten zonal y espacialmente en un dominio esencialmente superficial (A + B0-50 cm), con marcada tendencia a incrementarse. Estos resultados se deben interpretar como base indispensable para el diseño de estrategias de mitigación y adaptación con enfoque agroecológico en regiones de Cuba

Juvenis de pejerrey, Odontesthes bonariensis, foram expostos a Vermelho de Alizarina S (ARS) 0,1% de duas formas, sozinho ou com uma imersão anterior em 2,2% de solução salina (Indução osmótica, IO) para melhorar o método de marcação ARS. Os procedimentos foram realizados no campo e os peixes foram liberados em gaiolas (tanques-rede) de 1 m3 na lagoa "La Salada de Monasterio", Chascomús, Buenos Aires, Argentina. Após 73 dias, marcas claras foram observadas nos otólitos, raios da nadadeira caudal e escamas em ambos os tratamentos, sendo que a intensidade do sinal nas escalas de IO + ARS de peixe tratado foi superior. Por outro lado, não foram observados marcas no grupo controle sobre as mesmas estruturas. Aproximadamente um ano pós-tratamento (385 dias), apenas marcas nos raios da nadadeira caudal foram encontrados claramente nos peixes tratados com IO+ARS. Entre os peixes observados, após este período, não houve diferenças significativas no comprimento total ou peso entre o grupo controle e marcados, ademais, a mortalidade variou entre 30-40% em todas as gaiolas. Estes resultados fornecem fortes evidências e um grande potencial para aplicação desta técnica rentável de marcação que diferencia o pejerrey selvagem e o produzido em cativeiro. O sucesso na marcação dos raios da nadadeira caudal também é de grande importância, pois sua verificação é fácil e não requer o sacrifício de peixes

Juveniles of pejerrey, Odontesthes bonariensis, were exposed to 0.1% Alizarin Red S (ARS) alone or with a previous immersion in 2.2% saline solution (Osmotic Induction, OI) to enhance the ARS marking method. Fish were marked in the field and immediately released in 1 m3 cages in "La Salada de Monasterio" lagoon, Chascomús, Buenos Aires , Argentina. After 73 days, clear marks were observed in the otoliths, caudal fin rays and scales with both treatments, being the intensity of the signal in the scales of OI+ARS treated fish higher. On the other hand, no marks were observed in the control group on the same structures. Approximately one year post-treatment (385 days), only marks in caudal fin rays were found clearly in OI+ARS treated fish. After this period, no significant differences in total length or weight between marked or control fish were observed and the mortality ranged between 30-40 % in all cages. These results provide strong evidence for the potential applicability of this cost-effective marking technique in differentiation of wild and hatchery-produced pejerrey. The success in the caudal fin rays marking is also important because it is easy to do and does not require the sacrifice of fish.

A temperatura da água não afeta apenas as taxas de crescimento no peixe-rei, mas também direciona o processo de diferenciação sexual. Este fato levanta o questionamento de quão diferente é o desenvolvimento de larvas do peixe-rei da mesma idade quando criadas em temperaturas diferentes. Este trabalho teve como objetivo apresentar uma descrição do de desenvolvimento de embriões e larvas do peixe-rei, Odontesthes bonariensis, e a influência da temperatura de criação no desenvolvimento das larvas. Neste trabalho, o desenvolvimento das larvas foi estudado em três temperaturas diferentes de cultivo. Foram consideradas as alterações ocorridas na morfologia geral, assim como na morfologia e na estrutura da nadadeira caudal dentro da variação termal da temperatura de determinação sexual desta espécie. A taxa de reabsorção da membrana embrionária, a formação da cauda e o formato do corpo foram selecionados para acompanhar os eventos que levam à aquisição da morfologia juvenil. O fenótipo juvenil foi definido quando a nadadeira caudal foi reabsorvida e a cauda adquiriu a estrutura homocerca. O momento no qual o fenótipo juvenil foi atingido, foi avaliado quanto à idade, tamanho e formato da larva, sendo que o tamanho resultou no melhor indicador do desenvolvimento do peixe-rei.

It is well known that in pejerrey water temperature not only affects growth rates but also directs the sexual differentiation process. This fact rise the question of how different the development of pejerrey larvae of the same age is when reared at different temperatures. A description of developmental stages for the embryonic and larval periods of the pejerrey, Odontesthes bonariensis, and the influence of rearing temperature on larval development are presented. Then, larval development was studied at three rearing temperatures, and changes in general morphology, fin morphology, and caudal fin structure have been taken into consideration within the thermal range involved in the temperature sex determination of this species. Fin fold reabsorption, caudal fin formation, and body shape were selected to follow the events leading to the acquisition of the juvenile morphology. The juvenile phenotype was defined when the fin fold was reabsorpted and the caudal fin acquired its definitive homocercal structure. The moment at which the juvenile phenotype was achieved, was evaluated in relation to larval age, size and, shape. The size resulted as the best indicator of development in pejerrey.

Using biotechnology to increase the growth rates of fish is likely to reduce production costs per unit of food. Among vertebrates, fish appear to occupy a unique position, when growth patterns are considered. With few exceptions, fish species tend to grow indeterminately, implying that size is never fixed. Both hyperplasia and hypertrophy contribute to post-larval muscle growth in fish. Growth hormone (GH) - Insulin-like Growth Factor I (IGF-I) is the most important growth axis in fish. Our experimental model, the pejerrey, Odontesthes bonariensis (Ateriniformes) is a South American inland water fish considered to be a promising species for intensive aquaculture. However, one major drawback to achieve this goal is its slow growth in captivity. In order to understand how growth is regulated in this species, our first objective was to characterized pejerrey GH- IGF-I axis. We first cloned and characterized pejerrey (pj) GH, IGF-I and the growth hormone receptors (GHRs) I and II. In addition to providing valuable data for evolutionary comparison of GH, investigation of GH action in teleosts is particularly important because of its potential application in aquaculture. GH can not only promote the somatic growth in fish but also lower dietary protein requirements. A prerequisite for providing sufficient amounts of GH for basic research and aquaculture application is a large-scale production of GH. For that purpose, recombinant pjGH was expressed in a bacterial system. Protocols for solubilization and proper folding were achieved. Activity of recombinant pjGH was assessed in fish by measuring the liver IGF-I response to different doses of GH. IGF-I transcript was measured in the liver after pjGHr in vivo stimulation by means of quantitative real-time PCR assays. A dose-dependent response of IGF-I mRNA was observed after pjGHr administration, and reached a 6 fold IGF-I maximum increase over control group when 2.5 µg pjGH /g-body weight were injected. Temporal analysis of hepatic IGF-I mRNA levels showed that administration of a single dose of pjGHr into juvenile pejerrey resulted in a significant increase (P<0.02) 9 hours post injection. These results demonstrates that recombinant pjGH could promote a dramatic response in liver, increasing the IGF-I mRNA level. We also study the effect of GH on muscle growth after oral administration. A significant association between GH doses and mean fiber area (MFA) was observed even with a caloric restrictive diet. MFA increased 3.7 µm² per each unit of GH supplied indicating that GH promoted white muscle hypertrophy. These preliminary data indicates that GH could be absorbed by the intestine in an active form and promote somatic growth.

A maturação ovocitária final (FOM) é um processo complexo que envolve mecanismos genéticos, bioquímicos e morfológicos que conduzem à transformação de um ovócito pós-vitelogênico em um ovócito apto a ser fertilizado. Esse processo está regulado pelo hormônio esteróide indutor da maturação ovocitária final (MIS), o qual é sintetizado no folículo. Em outras espécies de Sciaenidae, o MIS foi identificado como um derivado hidroxilado da progesterona 17, 20beta, 21-trihydroxy-4-pregnen-3-one (20beta-S). Micropogonias furnieri é um recurso superexplorado na costa uruguaia, contudo, seus processos endócrinos são pouco conhecidos. O objetivo deste trabalho foi pesquisar quais esteróides são sintetizados in vitro pelos folículos em maturação de M. furnieri. Fragmentos de ovários (1 g) foram incubados em três estágios diferentes: pós-vitelogênese (PV), em maturação (Mtg) e maduros (M) com 1 mig/g de progesterona tritriada (P) durante 30, 60 e 180 min. Depois da extração dos esteróides com etanol e diclorometano, esses foram purificados e identificados utilizando-se TLC, rpHPLC e oxidação enzimática. Foram identificados dois derivados de progesterona com idênticas propriedades cromatográficas ao 20beta-S e 17,20beta-dihydroxy-4-pregnen-3-one (17,20beta-P), os quais, em outras espécies de peixes, apresentam atividade biológica como o MIS. A 17,20beta-P foi observada claramente nos estágios Mtg e M e confirmada pela oxidação com a enzima 20beta-HSD. A 20beta-S foi claramente observada nos ovários em maturação (Mtg). Os resultados não permitiram confirmar que 20beta-S é o hormônio mais sintetizado nos estágios estudados, como ocorre em outras espécies de ciaenídeos, mas a presença de uma síntese diferencial no estágio de maturação sugere que 20beta-S esteja atuando como o MIS em M. furnieri.

Final oocyte maturation (FOM) is a process involving a complex set of genetical, biochemical, and morphological mechanisms. FOM involves the shift of a post-vitellogenic follicle to a pre-ovulated oocyte, which is necessary for fertilization by spermatozoan to occur. This process is regulated by a maturation-inducing steroid (MIS) at the follicular level. In other species of scienids fish the MIS, a hydroxilated derivatives of progestagen 17, 20beta, 21-trihydroxy-4-pregnen-3-one (20beta-S), was identified. Although Micropogonias furnieri is the second fishery resource of Uruguay, basic knowledge about its endocrine process is very scarce. The aim of this work was to investigate what steroids are synthesized in vitro by the oocyte follicle of M. furnieri during the maturation process. Fragments of ovary (1 g) in three stages: post-vitellogenic (PV), maturing (Mtg), and mature (M) were incubated with 1 mug.g-1 of tritiated progesterone (P) at 30, 60, and 180 min. After extraction with ethanol and dichloromethane, steroid metabolites were purified by TLC and rpHPLC. Two progesterone derivatives with identical chromatographic properties of 20beta-S and 17,20beta-dihydroxy-4-pregnen-3-one (17,20beta-P) were purified. In other Teleost fish these steroids are biologically activ as MIS. The 17,20beta-P was clearly detected in Mtg and M stages and confirmed by enzymatic oxidation with enzyme 20beta-HSD. The 20beta-S was strongly detected in all Mtg oocytes. The results do not corroborate 20beta-S as a major hormone synthesized in the ovary in FOM as occurs in other scienid fish. A differential steroid synthesis in the advanced oocyte stages suggests that the 20beta-S is acting as a MIS in M. furnieri.

Ten patients treated with vincristine were submitted for electrophysiological examination. It was investigated the number of motor units within the thenar muscle following a technique described previously (Sica et al. — 1974); motor and sensitive conduction velocities as well as motor distal latencies in the median nerve were studied following conventional techniques. The behaviour of the evoked muscle potential with repetitive supramaximal stimulation over the median nerve was also investigated. The findings were compared with control groups. The estimated number of motor units was disminished in eight of ten patients and the average number was significantly different from the control group (control 318 ± 71 UM; patients 174 ± 84 UM; P < 0.001). The potential amplitudes in most of the surviving units were reduced, others remaining within the normal range. This makes apparent that the peripherical nervous system fails to compensate adequatly and, furthermore, a loss of individual muscle fibres occurs within some individual units. The conduction velocities of the fastest conducting motor nerve fibres were reduced and motor distal latencies prolongued (Table 1). Maximal impulse conduction velocities were measured in sensory fibres. In 5 of 7 subjets investigated the values laied just beyond the lower limit of the normal range. The amplitude of the sensory orthodromic evoked potential in the median nerve at the wrist was disminished almost in the whole group. The decremental muscle response to repetitive nerve stimulation, can be interpreted as the result of the damage at the neural apparatus at the motor end plate; it was observed in 57% of the patients. In summary, evidences have been registered showing that the nervous supply to the muscle is affected in patients treated with vincristine; the motor unit behaviour under this conditions is discussed.

Diez pacientes afectados por diversas patologías que requerían tratamiento crónico con Vincristina, fueron sometidos a estudios electrofisiológicos en los que se valoró: el número de unidades motoras (UM) funcionantes en los músculos de la eminencia tenar, los valores de los incrementos medios de UM, velocidad de conducción motora y su latencia residual en el nervio mediano, la velocidad de conducción sensitiva del mismo nervio y el estado de la transmisión neuromuscular. Los valores obtenidos fueron comparados con grupos controles. Los resultados mostraron disminución del número de UM; las UM remanentes presentaron amplitud reducida junto a otras cuyo tamaño no superaba el del grupo control, hecho que sugiere la incapacidad de lograr una reinervación adecuada. Las velocidades de conducción motora y sensitiva mostraron valores diminuídos, con mayor compromiso en los segmentos distales. Junto a estos datos se halló respuesta miasteniforme al estímulo repetitivo. Todos estos resultados permiten postular la existencia de un compromiso de la unidad motora, abarcando todos sus segmentos, en pacientes intoxicados con Vincristina.