Determinación del área ventilatoria interumbral en individuos con diferentes capacidades de resistencia / Determining the ventilatory inter-threshold area in individuals with different endurance capacities

Existe un consenso general de que hay dos puntos de ruptura de la ventilación durante el ejercicio incremental, el umbral ventilatorio 1 (VT1) y el umbral ventilatorio 2 (VT2), que marcan los límites de la transición aeróbica-anaeróbica. El área interumbral se ha definido como un parámetro que relaciona los umbrales ventilatorios. El objetivo principal del presente estudio fue examinar el área entre los umbrales (ITA), es decir, el área entre VT1 y VT2 para la función ventilación/absorción de oxigeno. Seiscientos seis varones con diferentes estados de condición física, desarrollaron una prueba de esfuerzo incremental y se registraron los umbrales ventilatorios. EL ITA es un trapecio cuya área se calcula como la suma del área del triángulo y rectángulo que lo forman, tal como se muestra en la figura entre VT1 y VT2 y que permanecen por debajo de la función VO2/VE. La media de ITA para la función VO2-VE fue mayor en los ciclistas, como representantes de deportistas de resistencia, frente al área correspondiente a los estudiantes de educación física con menores niveles de resistencia (120±34 vs. 86±40L2/min2). Estos resultados sugieren que la determinación del ITA puede reflejar adecuadamente el estado metabólico durante el proceso de transición aeróbico-anaeróbico durante las pruebas de esfuerzo incrementales

There is a general consensus in the literature regarding the existence of two ventilation break points during incremental exercise, i.e., Ventilatory Threshold 1 (VT1) and Ventilatory Threshold 2 (VT2), which mark the boundaries of the aerobic-anaerobic transition. The Inter-Threshold Area (ITA) has been defined as a parameter that connects the ventilatory thresholds. The main aim of the present study was to examine the ITA i.e., the expressed area between VT1 and VT2 for the function: ventilation÷oxygen uptake (VE/VO2 in L2min2) in individuals with various endurance capacities. Six hundred and six men with different levels of endurance completed an incremental exercise test and their ventilatory thresholds were recorded. The ITA is a trapezoid whose area is calculated as the sum of the area of the triangle and rectangle that form it between VT1 and VT2 below the VO2/VE function. The mean ITA for the function VO2-VE was greater in cyclists, as the main representatives for endurance athletes, than the mean corresponding to physical education students, who averaged a lower endurance level (120±34 vs. 86±40L2/min2). The results suggest that the determination of the ITA can reflect metabolic status throughout the aerobic-anaerobic transition during maximal incremental exercise tests

Arsenic, cobalt and chromium food web biodilution in a Patagonia mountain lake.

Mussels, Diplon chilensis, from Lake Moreno, a double-basined mountain lake in southern Argentina, is known to have elevated concentrations of chromium (Cr, > 25 µg g⁻¹ dry weight DW) and arsenic (As, 35 µg g⁻¹ DW), attributed to untreated sewage. To further understand the trophodynamics of Cr, As and cobalt (Co), we investigated concentrations and transfer throughout the food web in each basin of Lake Moreno. Each basin differs in morphology in that the gently-sloping Lake Moreno West has more littoral habitat than deeper Lake Moreno East with its higher proportion of pelagic habitat. Despite the morphological differences, both basins share similar water quality parameters and species assemblages. As a result, Lake Moreno provides an exceptional opportunity to compare trophodynamics of elements that enable us to hypothesize pelagic-littoral habitat coupling in response to lake morphology as the underlying factor influencing both Cr pathway and Co and As trophodynamic modeling. Using stable isotopes of nitrogen (δ¹5N) and carbon (δ¹³C) to characterize metals trophodynamics in each basin, biodilution of As, Cr and Co were indicated by negative regressions. This is confirmed by elevated As, Co and Cr concentrations in phytoplankton (11.3±5.7, 7.4±4.9, 44.5±40.7 µg g⁻¹ DW respectively), while zooplankton and biofilm had the next elevated concentrations. Those elevated concentrations are in contrast with lower concentrations in sport fish such as rainbow trout (0.5±0.5, 0.2±0.3, 1.8±1.2 µg g⁻¹ DW). Higher concentrations of Cr in fish were associated with higher proportion of benthic/littoral prey items in western basin, and were confirmed by significant correlation with δ¹³C values. Arsenic, Co and Cr concentrations in fish, while elevated, do not post health risks to human or wildlife consumers.

Trophodynamics and distribution of silver in a Patagonia mountain lake.

Silver (Ag) ions are among the most toxic metallic ions to aquatic biota. In southern Argentina, fish from Patagonian lakes have liver Ag concentrations [Ag] among the highest ever reported globally. Silver concentration in phytoplankton from Lake Moreno (1.82±3.00µgg(-1) dry weight, DW) was found to be significantly higher than [Ag] in zooplankton (0.25±0.13µgg(-1)). Values in snails and decapods (0.60±0.28µgg(-1) and 0.47±0.03µgg(-1) respectively), were higher than in insect larvae (0.28±0.39µgg(-1) for Trichoptera). We examined trophic transfer of Ag in the biota using stable nitrogen and carbon isotopes ratios (δ(15)N and δ(13)C respectively). Silver concentrations in the biota of Lake Moreno were not associated with any particular C source, as assessed by δ(13)C. Hepatic [Ag] significantly increased with trophic position, as measured by δ(15)N, within the brook trout sample set. Biodilution of Ag was observed between primary producers and small forage fish when whole body [Ag] was analyzed. Nevertheless, when considering whole food web biomagnification and hepatic [Ag] of top predator fish, a significant positive regression was found between [Ag] and trophic position, as measured by δ(15)N. The importance of species-specific and tissue-specific considerations to obtain more information on Ag trophodynamics than that usually presented in the literature is shown. To the best of our knowledge, this is the first study in assessing Ag trophodynamics and tissue-specific biomagnification in a whole freshwater food web.

Galaxias maculatus (Galaxiidae, Salmoniformes) infectados com Acanthostomoides apophalliformis (Digenea, Platyhelminthes) no Sul da Argentina. Histopatologia e ausência de mortalidade induzida / Galaxias maculatus (Galaxiidae, Salmoniformes) infected with Acanthostomoides apophalliformis (Digenea, Platyhelminthes) in Southern Argentina. Pathology and absence of parasite induced mortality

This study was conducted to analyze at histopathological level, lesions produced by Acanthostomoides apophalliformis in the native fish Galaxias maculatus, and relate them to quantitative results on parasite- induced fish mortality, in Lake Moreno, Southern, Argentina. Absence in most lesions of inflammatory reaction, unaltered hepatic parenchyma at a short distance from the foci of the lesions and viable appearance of parasites, all suggest a good reciprocal adaptation.. This hypothesis is reinforced by data showing the absence of A. apophalliformis induced mortality in the fish population.

Este estudo foi conduzido para analisar ao nível histopatológico, lesões produzidas por Acanthostomoides apophalliformis no peixe nativo Galaxias maculatus, e relacioná-las com os resultados do mortalidade induzida por parasitas na população dessa espécie, no lago Moreno, Parque Nacional Nahuel Huapi, Argentina. A ausência de inflamação na maioria das lesões, o fígado sem alterações em uma distância curta do foco das lesões e a aparência viável dos parasitas, sugerem uma boa relação parasita-hospedeiro. Esta hipótese é reforçada pelos dados que mostram a ausência de mortalidade induzida por A. apophalliformis na população dos peixes.

Evaluación del grado de conocimiento en alimentación de una población universitaria / Evaluation the degree of knowledge in diet and nutrition from High School Students

Fundamento: La influencia de una buena nutrición está directamente relacionada con el crecimiento de la población. Actualmente, existen numerosas evidencias epidemiológicas que ponen de manifiesto que la dieta constituye un importante factor de riesgo en el estado de salud; no obstante, es cierto que las intervenciones de educación nutricional contribuyen a la reducción de un número de enfermedades de origen nutricional. Métodos: Se ha realizado una evaluación del grado de conocimientos en materia de alimentación y nutrición de un colectivo de 51 personas(16 mujeres y 35 hombres), de edad comprendida entre los 18-23 años. Los sujetos participantes pertenecen a una residencia universitaria de la ciudad de Sevilla (España); éstos no cursan estudios universitarios en licenciaturas relacionadas con las ciencias de la salud. Para llevar a cabo dicho estudio, se ha utilizado el cuestionario de valoración de grado de información en alimentación, distribuido en la II Edición del Día Nacional de la Nutrición (28 Mayo2003). Resultados: Los resultados obtenidos muestran un desconocimiento en algunos conceptos relacionados con los alimentos, sus fuentes dietéticas y sus funciones en el organismo. Por otro lado, se observa la influencia de los medios de comunicación, y/o otras vías en la información y valoración que realizan los participantes sobre algunos alimentos. Conclusiones: La educación nutricional es necesaria para modificar aquellas conductas que reporten perjuicios a la salud, consiguiendo mejorar algunos hábitos que garanticen un buen estado de salud. Por último indicar que los medios de comunicación no deben constituirla base general del conocimiento en nutrición y alimentación de la población universitaria (AU)

Background: The influence of a good nutrition is directly related to the growth of the population. At the moment many epidemiological studies showed that diet is an important factor of risk in the health state; despite it is certain that health nutritional program could reduce a number of diseases, which have a nutritional origin. Methods: It has been made an evaluation of the degree of knowledge in diet and nutrition. The study subjects were fifty-one (sixteen women and thirty-five men) of age between the 18-23 years. The participant subjects live in a residence from Seville (Spain); these students do not study in degrees related to health sciences. In order to carry out this study the questionnaire of valuation of degree of knowledge in diet and nutrition were distribuited in the Second Edition of the Nutritional Day in Spain (28 th May2003).Results: The results showed ignorance in some concepts related which foods, their dietetic sources as their functions. By another side is observed the influence of mass media and/or others ways in the information and valuation that the participants make on Some of foods. Conclusions: The health nutritional programme becomes necessary to improve a nutritional healthy habbits. On the other hand mass media like publicity does not have to be the general base of the knowledge in nutrition and feeding in High School students (AU)

[Spontaneous cervical emphysema and pneumomediastinum with voice disorders]. / Neumomediastino y enfisema cervical espontáneos con alteración en la voz.

Spontaneous cervical emphysema and pneumomediastinum, occurring in the absence of previous disorders or provocating factors, is very rare. The predominant symptoms are retroesternal pain, dyspnea, dysphagia and neck pain. The diagnosis is established radiologically. The evolution is generally good and conservative therapy leads to recovery in most patients. We present an unusual case of pneumomediastinum, cervical and retropharyngeal emphysema that spread to cavum; the suspected symptom was voice alteration as reported by the parents.

Infections by helminth parasites in "Puyenes", Galaxias maculatus (Galaxiidae, Salmoniformes), from Southern Argentina with special reference to Tylodelphys barilochensis (Digenea, Platyhelminthes)

The occurrence of Tylodelphys barilochensis, Acanthostomoides apophalliformis, Contracaecum sp. and Camallanus corderoi infecting Galaxias maculatus ("puyenes") was quantified for the first time in Lake Nahuel Huapi, southern Argentina. T. barilochensis was recorded in this lake for the first time. The role of G. maculatus population in transmission of parasites to the salmonids is more important for Contracaecum sp. (prevalence 14-34 per cent) and A. apophalliformis (prevalence 30-54 per cent) than for C. corderoi (prevalence 6-8 per cent). The absence of Diphyllobothrium spp. in samples shows that the G. maculatus population does not play any role in the life cycles of these important zoonotic parasites. The sex of the host had no effect on T. barilochensis abundance. Statistical differences in T. barilochensis abundance between "puyenes" of the same size class between sampling stations and positive correlation between prevalence of infected snails and T. barilochensis abundance in fish suggest that different stocks have been sampled. Factors influencing T. barilochensis abundance are discussed.

Infections by helminth parasites in "puyenes", Galaxias maculatus (Galaxiidae, Salmoniformes), from Southern Argentina with special reference to Tylodelphys barilochensis (Digenea, Platyhelminthes).

The occurrence of Tylodelphys barilochensis, Acanthostomoides apophalliformis, Contracaecum sp. and Camallanus corderoi infecting Galaxias maculatus ("puyenes") was quantified for the first time in Lake Nahuel Huapi, southern Argentina. T. barilochensis was recorded in this lake for the first time. The role of G. maculatus population in transmission of parasites to the salmonids is more important for Contracaecum sp. (prevalence 14-34%) and A. apophalliformis (prevalence 30-54%) than for C. corderoi (prevalence 6-8%). The absence of Diphyllobothrium spp. in samples shows that the G. maculatus population does not play any role in the life cycles of these important zoonotic parasites. The sex of the host had no effect on T. barilochensis abundance. Statistical differences in T. barilochensis abundance between "puyenes" of the same size class between sampling stations and positive correlation between prevalence of infected snails and T. barilochensis abundance in fish suggest that different stocks have been sampled. Factors influencing T. barilochensis abundance are discussed.

Diphyllobothrium dendriticum and Diphyllobothrium latum in fishes from southern Argentina: association, abundance, distribution, pathological effects, and risk of human infection.

Diphyllobothrium dendriticum and Diphyllobothrium latum are reported for the first time from Argentina. The following species from Lake Moreno (southern Argentina) were studied to determine whether plerocercoids were present: 11 brook trout (Salvelinus fontinalis), 32 perca (Percichthys sp.), 21 pejerrey (Patagonina hatcheri), and 114 rainbow trout (Oncorhynchus mykiss). Brook trout harbored both species (27.3% prevalence of D. dendriticum and 9.0% of D. latum); perca harbored only D. latum (18.7% prevalence); pejerrey were not infected and rainbow trout also harbored both species, with significant association. Diphyllobothrium latum was less abundant (1.4 plerocercoids/fish, 28.0% prevalence) than D. dendriticum (7.2 plerocercoids/fish, 57.8% prevalence) implying a lower health risk for humans. For both parasites, rainbow trout seem to be more important than the other host species studied. There is no evidence that either of the species is more harmful to the host. The lack of significant weight variation of the liver as related to intensity of infection strongly suggests that competition for energy is not an important aspect of the host pathology.