Gut microbiome resilience of green-lipped mussels, Perna canaliculus, to starvation

Host gut microbiomes play an important role in animal health and resilience to conditions, such as malnutrition and starvation. These host-microbiome relationships are poorly understood in the marine mussel Perna canaliculus, which experiences significant variations in food quantity and quality in coastal areas. Prolonged starvation may be a contributory factor towards incidences of mass mortalities in farmed mussel populations, resulting in highly variable production costs and unreliable market supplies. Here, we examine the gut microbiota of P. canaliculus in response to starvation and subsequent re-feeding using high-throughput amplicon sequencing of the 16S rRNA gene. Mussels showed no change in bacterial species richness when subjected to a 14-day starvation, followed by re-feeding/recovery. However, beta bacteria diversity revealed significant shifts (PERMANOVA p-value < 0.001) in community structure in the starvation group and no differences in the subsequent recovery group (compared to the control group) once they were re-fed, highlighting their recovery capability and resilience. Phylum-level community profiles revealed an elevation in dominance of Proteobacteria (ANCOM-BC p-value <0.001) and Bacteroidota (ANCOM-BC p-value = 0.04) and lower relative abundance of Cyanobacteria (ANCOM-BC p-value = 0.01) in the starvation group compared to control and recovery groups. The most abundant genus-level shifts revealed relative increases of the heterotroph Halioglobus (p-value < 0.05) and lowered abundances of the autotroph Synechococcus CC9902 in the starvation group. Furthermore, a SparCC correlation network identified co-occurrence of a cluster of genera with elevated relative abundance in the starved mussels that were positively correlated with Synechococcus CC9902... (AU)

The intestinal microbiota of a Risso’s dolphin (Grampus griseus): possible relationships with starvation raised by macro-plastic ingestion / La microbiota intestinal del delfín gris (Grampus griseus): posibles relaciones con la inanición provocada por la ingestión de macroplásticos

Ingesting marine plastics is increasingly common in cetaceans, but little is known about their potential effects. Here, by utilizing 16S rRNA gene sequencing, we profiled the intestinal bacterial communities of a stranded Risso’s dolphin (Grampus griseus) which died because of the ingestion of rubber gloves. In this study, we explored the potential relationships between starvation raised by plastic ingestion with the dolphin gut microbiota. Our results showed significant differences in bacterial diversity and composition among the different anatomical areas along the intestinal tract, which may be related to the intestinal emptying process under starvation. In addition, the intestinal bacterial composition of the Risso’s dolphin showed both similarity and divergence to that of other toothed whales, suggesting potential roles of both host phylogeny and habitat shaping of the cetacean intestinal microbiome. Perhaps, the microbiota is reflecting a potentially disordered intestinal microbial profile caused by the ingestion of macro-plastics which led to starvation. Moreover, two operational taxonomic units (0.17% of the total reads) affiliated with Actinobacillus and Acinetobacter lwoffii were detected along the intestinal tract. These bacterial species may cause infections in immunocompromised dolphins which are malnourished. This preliminary study profiles the intestinal microbiota of a Risso’s dolphin, and provides an additional understanding of the potential relationships between starvation raised by ingesting macro-plastics with cetacean gut microbiota.(AU)

Adelantar la muerte dejando de comer y beber. ¿Un nuevo tipo de "suicidio asistido"? / Hastening death by voluntary stopping of eating and drinking. A new mode of assisted suicide?

En los últimos años ha comenzado a aparecer en la literatura médica y bioética la dicción inglesa "voluntary stopping of eating and drinking". Se trata de una práctica que se propone con la "intención primaria" de anticipar la muerte de una persona que no quiere seguir viviendo, como alternativa a la eutanasia y al suicidio asistido. Algunos autores la presentan como una opción válida tanto desde el punto de vista ético como legal, sosteniendo que no se trata de un suicidio sino de una "muerte natural", en la línea de la limitación de tratamientos. En este artículo presentamos una síntesis de la bibliografía reciente, y una valoración crítica que llega a la conclusión que este tipo de acción difícilmente puede considerarse algo distinto a una modalidad de suicidio. Como consecuencia, el personal sanitario debería considerarla extraña al ethos médico y a la buena praxis clínica

In the last few years, the new catch phrase "voluntary stopping of eating and drinking" has made its appearance in the medical and bioethical literature. The practice, whose "primary intention" is to hasten the death of a person who does not want to continue living, has been proposed as an alternative to euthanasia and assisted suicide. Some authors present it as a valid option from both the ethical and legal point of view arguing that it is basically a "natural death" in the same line as a limitation of treatment and does not involve suicide. In this article we present a critical review of the recent literature and reach the conclusion that it is very difficult to consider this practice as anything other than a type of suicide. In consequence, healthcare workers should consider it alien to medical ethos and good clinical practice

Cetoacidosis no diabética en una mujer embarazada, debido a inanición aguda con gripe A (H1N1) concomitante e insuficiencia respiratoria / Nondiabetic ketoacidosis in a pregnant woman due to acute starvation with concomitant influenza A (H1N1) and respiratory failure

Raramente se reporta la acidosis metabólica resistente de riesgo debido a cetoacidosis no diabética por inanición a corto plazo. La cetoacidosis grave debida a inanición es una situación infrecuente y lo es más aún durante el embarazo con situación clínica estresante concomitante. Este informe de un caso presenta a una mujer no diabética ingresada en cuidados intensivos debido a insuficiencia respiratoria tipo 1 durante el tercer trimestre de embarazo, con acidosis metabólica grave resistente a tratamiento médico. Diagnosticamos a la paciente de cetoacidosis por inanición, basándonos en su historia y la ausencia de otras causas de acidosis metabólica con anión gap elevado, tras la realización de un análisis riguroso de su trastorno ácido-base

Threatening refractory metabolic acidosis due to short-term starvation nondiabetic ketoacidosis is rarely reported. Severe ketoacidosis due to starvation itself is a rare occurrence, and more so in pregnancy with a concomitant stressful clinical situation. This case report presents a nondiabetic woman admitted in intensive care for respiratory failure type 1 during the third trimester of pregnancy with a severe metabolic acidosis refractory to medical treatment. We diagnosed the patient with acute starvation ketoacidosis based on her history and the absence of other causes of high anion gap metabolic acidosis after doing a rigorous analysis of her acid-base disorder

Trastornos neurológicos relacionados con la malnutrición en la Guerra Civil Española (1936-1939) / Neurological changes related to malnutrition during the Spanish civil war (1936-1939)

En esta conferencia, dictada en el marco de las Jornadas Internacionales de Neurociencias, Quito, Mayo 31 a Junio 1, 2013, se hizo una exposición de lo que fueron las situaciones de hambruna acaecidas en España durante la Guerra Civil de 1936-39. Su capital, Madrid sufrió durante todo ese periodo racionamientos de alimentos, agua y leche. Esta situación dio lugar a unas condiciones que pusieron de manifiesto las relaciones entre sistema nervioso y alimentación. La población madrileña estuvo sometida a un verdadero experimento de hipo alimentación, análogo al que se puede realizar en el laboratorio. Al concluir la guerra, la Dirección General de Sanidad y el Instituto de Investigaciones Médicas, con la colaboración de la Fundación Rockefeller, realizaron una serie de encuestas clínicas y de consumo alimentario entre la población de Madrid. Hubo tres situaciones médicas que tuvieron especial relevancia durante la Guerra Civil y durante la posguerra: La epidemia de pelagra, la aparición de latirismo y el denominado síndrome de Vallecas. La aparición de casos de pelagra fue trascendental porque permitió, a partir de una avitaminosis conocida, replantearse toda la sintomatología inespecífica que se había estado observando. La pelagra pasó a ser la enfermedad carencial más prevalente, y la más claramente vinculada a la alimentación. El latirismo es una intoxicación crónica producida por la acumulación de neurotoxinas. Se debe al consumo frecuente de almortas (Lathyrus sativus). La almorta es toxica solo cuando constituye más del 30% de las calorías diarias consumidas durante un período continuado de dos a tres meses. El Latirismo volvería a afectar a los españoles durante los años 1941 y 1942, en los llamados "años del hambre" de la posguerra, cuando, debido a la escasez de alimentos, fue consumida gran cantidad de harina de almortas. Las neuropatías carenciales observadas en Madrid durante la Guerra Civil dieron lugar a descripciones clínicas novedosas y originales. En niños de colegios del barrio de Vallecas se describió un síndrome carencial, probable mente de vitaminas del complejo B, que originaba calambres musculares y debilidad muscular, que se dio en llamar síndrome de Vallecas. Se destacó la pobreza en grasas de la dieta y una ligera disminución de la cifra de calcio, ya muy pobre, en el grupo con calambres. Tanto con la administración de tabletas conteniendo una proporción adecuada de calcio y fósforo como con la ingestión diaria de 4 a 6 miligramos de tiamina, consiguieron hacer desaparecer los calambres musculares o aminorar considerablemente su frecuencia e intensidad (AU)

In this lecture, given at the International Conferences on Neuroscience, in Quito, May 31st-June 1st of 2013, the topic of famine situations during the Spanish Civil War, 1936-1939, was approached. Madrid, the capital of Spain, was under food, water and milk rationing during that period. This situation led to conditions that showed the relationships between the nervous system and nutrition. The Madrilenian population was submitted to a real experiment of hyponutrition, similar to the one that may be reproduced at the laboratory. At the end of the war, the National Direction on Health and the Institute of Medical Investigations, with the collaboration of the Rockefeller Foundation, carried out a series of clinical and food consumption surveys among the Madrilenian population. There were three medical situations that were of particular relevance during the Civil War and after it: the pellagra epidemics, the onset of lathyrism, and the socalled Vallecas syndrome. The occurrence of pellagra cases was paramount because it allowed reconsidering all the unspecific symptoms observed from an already known vitamin deficiency. Pellagra became the most prevalent deficitrelated disease, and most clearly related to nutrition. Lathyrism is a chronic intoxication produced by the accumulation of neurotoxins. It is due to common intake of chickling peas (Lathyrus sativus). Chickling peas are toxic only if they represent more than 30% of the daily calories consumed for a prolonged period greater than two to three months. Lathyrism would reoccur in the Spanish population after the war, in 1941 and 1942, the so called "famine years", when due to the scarcity of foods chickling pea flour was again consumed in high amounts. Deficiency-related neuropathies observed in Madrid during the Civil War led to new and original clinical descriptions. In children from schools of the Vallecas neighborhood, a deficiency syndrome, likely related to vitamin B complex deficiency, was described, which manifested by muscle cramps and weakness, and was termed the Vallecas syndrome. Poor fat content in the diet and a light decrease in calcium levels, which were already very low, were observed in the group with cramps. Both the administration of tablets containing an adequate amount of calcium and phosphorus and the daily intake of 4-6 milligrams of thiamine, achieved a considerable reduction in the frequency and severity of the cramps, or their complete resolution (AU)

Self-starvation in the rat: running versus eating

Rats given the combination of unrestricted access to an activity wheel and restricted access to food can lose weight to the extent that they will die unless removed from these conditions. Although this has been known for forty years, why this happens has remained unclear. The phenomenon is paradoxical in that one might expect such rats to eat more as their weight decreases, but in fact they eat less than resting controls. This lecture first examines some of the factors than influence whether self-starvation will occur, such as age, time of food access, type of food and ambient temperature. It then compares competing explanations such as circadian adaptation, thermo-regulation and food aversion learning. As so often in psychology, it turns out that self starvation results from a combination of many separate factors. The general implications of this research are examined, including whether it provides a useful animal model for human anorexia nervosa (AU)

Las ratas sometidas simultáneamente a restricción de comida y acceso a una rueda de actividad pierden peso hasta el extremo de morir si no son retiradas a tiempo de estas condiciones. Aunque este hecho es conocido desde hace cuarenta años, la razón por la cual esto sucede permaneces in resolver. Lo paradójico de este fenómeno reside en que, aunque sería esperable que las ratas comiesen más a medida que su peso disminuye, en realidad estos animales comen menos que sus controles sedentarios. En esta conferencia se examina, en primer lugar, algunos factores que influyen en el desarrollo de la auto-inanición como son la edad, el tiempo de acceso a la comida, el tipo de comida y la temperatura ambiental. A continuación se comparan algunas explicaciones tales como la adaptación del ritmo circadiano, la termorregulación y la aversión adquirida a la comida. Tal como ocurre con frecuencia en psicología, la auto-inanición es el resultado de diferentes factores. Finalmente, se examinarán algunas implicaciones más generales de esta investigación, incluida su posible utilidad como modelo animal para el estudio de la anorexia nerviosa en humanos (AU)

Beta-Galactosidase activity of Escherichia coli under long-term starvation, alterations in temperature, and different nutrient conditions in lake water

beta-Galactosidase activity of Escherichia coli was investigated in response to long-term starvation, changes in temperature and the presence of certain nutrient sources in lake water. beta-Galactosidase activity decreased markedly in filtered-autoclaved lake water at 25 degrees C and 37 degrees C, whereas it remained almost constant at 4 degrees C and 15 degrees C for 60 days. Increases in beta-galactosidase activity were observed in response to the following nutrient sources: glycine, serine, methionine and ammonium sulfate at 4 degrees C; glycine and ammonium sulfate at 15 degrees C; glycine, serine, methionine and ammonium sulfate at 30 degrees C. Glycine addition led to an increase in beta-galactosidase activity of almost five and seven orders of magnitude at 15 degrees C and 30 degrees C, respectively. In addition, L-methionine had the strongest influence on beta-galactosidase activity, which was detected as an increase of seven and eleven orders of magnitude at 4 degrees C and 30 degrees C, respectively. The effect of several amino acids and other nitrogen sources depended on the concentration of the nutrient source and the temperature. The results showed that, in lake water, long-term starvation, temperature change, and variations in nitrogen sources alter beta-galactosidase activity. Those effects should be taken into account when monitoring coliforms from the environment (AU)

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