Suicide by ethylene glycol/brake oil poisoning—a case report

Background Brake fluid is used for automobiles. It is a mixture of different glycol derivatives including ethylene glycol and diethylene glycol (DEG) which are metabolized into various toxic metabolites. Fatalities following brake fluid ingestion are rare in forensic practice. Here, we report a case of suicide by brake fluid ingestion complicated with severe renal failure and esophageal and gastric erosions. Case presentation A 52-year-old male, with a history of alcohol dependence and comorbid moderate depression, ingested a bottle of brake fluid (100ml) mixed with alcohol. He had defaulted psychiatric follow-up. He developed severe metabolic acidosis and acute renal failure which necessitated intensive care, other supportive management, and the antidote; ethyl alcohol. On the 2nd day of admission, he developed upper gastrointestinal bleeding with melena. He also had seizures and cardiovascular complications. He died 12 days after hospital admission, and the manner of death was concluded as suicidal. The autopsy revealed congested and edematous brain, flabby and pale heart without evidence of infarction, erythematous trachea, bilateral diffuse pulmonary edema, congested liver, ulcer over the lower 1/3 of the esophagus, and few ulcers in the stomach. Also, the kidneys were edematous, diffusely necrosed, and there were adrenal hemorrhages. Conclusions This case report highlights the severity of effects of brake fluid poisoning including the corrosive effect on gastrointestinal mucosa which is rarely encountered in clinical practice.

Provision of instructions to drink ad libitum or according to thirst sensation: impact during 120 km of cycling in the heat in men

The terms drinking to thirst and ad libitum drinking are used interchangeably, but should they? We investigated the differences in how athletes consume fluids during exercise when instructed to drink according to thirst or ad libitum. Using a randomized, crossover and counterbalanced design, 10 males (27 ± 4 y) cycled 120 km (48 ± 4% of peak power, 33°C, 40% relative humidity) on two occasions, while drinking water according to thirst or ad libitum. Participants covered the cycling trials in 222 ± 11 min (p = 0.29). Although the body mass loss at the end of exercise and total volume of water consumed were similar between trials, thirst perception before each sip and the volume consumed per sip were significantly higher with thirst than ad libitum drinking, whereas the total number of sips was significantly lower with thirst than ad libitum drinking. Perceived exertion, rectal temperature and heart rate were all significantly higher with thirst than ad libitum drinking, but the difference was trivial. In conclusion, thirst and ad libitum drinking are associated with different drinking patterns, but equally maintain fluid balance during prolonged exercise. The terms drinking to thirst and ad libitum drinking can be used interchangeably for guiding fluid intake during prolonged exercise. NOVELTY • Both strategies are associated with different patterns of fluid ingestion during prolonged exercise, but are equally effective in maintaining fluid balance; • Perceived exertion, rectal temperature and heart rate are regulated dissimilarly by thirst and ad libitum drinking, but the difference is trivial.

Behavioral variation according to feeding organ diversification in glossiphoniid leeches (Phylum: Annelida)

Adaptive radiation is a phenomenon in which various organs are diversified morphologically or functionally as animals adapt to environmental inputs. Leeches exhibit a variety of ingestion behaviors and morphologically diverse ingestion organs. In this study, we investigated the correlation between behavioral pattern and feeding organ structure of leech species. Among them, we found that Alboglossiphonia sp. swallows prey whole using its proboscis, whereas other leeches exhibit typical fluid-sucking behavior. To address whether the different feeding behaviors are intrinsic, we investigated the behavioral patterns and muscle arrangements in the earlier developmental stage of glossiphoniid leeches. Juvenile Glossiphoniidae including the Alboglossiphonia sp. exhibit the fluid ingestion behavior and have the proboscis with the compartmentalized muscle layers. This study provides the characteristics of leeches with specific ingestion behaviors, and a comparison of structural differences that serves as the first evidence of the proboscis diversification.

Food Entrainment, Arousal, and Motivation in the Neonatal Rabbit Pup

In the newborn rabbit, the light entrainable circadian system is immature and once a day nursing provides the primary timing cue for entrainment. In advance of the mother’s arrival, pups display food anticipatory activity (FAA), and metabolic and physiological parameters are synchronized to this daily event. Central structures in the brain are also entrained as indicated by expression of Fos and Per1 proteins, GFAP, a glial marker, and cytochrome oxidase activity. Under fasting conditions, several of these rhythmic parameters persist in the periphery and brain, including rhythms in the olfactory bulb (OB). Here we provide an overview of these physiological and neurobiological changes and focus on three issues, just beginning to be examined in the rabbit. First, we review evidence supporting roles for the organum vasculosum of lamina terminalis (OVLT) and median preoptic nucleus (MnPO) in homeostasis of fluid ingestion and the neural basis of arousal, the latter which also includes the role of the orexigenic system. Second, since FAA in association with the daily visit of the mother is an example of conditioned learning, we review evidence for changes in the corticolimbic system and identified nuclei in the amygdala and extended amygdala as part of the neural substrate responsible for FAA. Third, we review recent evidence supporting the role of oxytocinergic cells of the paraventricular hypothalamic nucleus (PVN) as a link to the autonomic system that underlies physiological events, which occur in preparation for the upcoming next daily meal. We conclude that the rabbit model has contributed to an overall understanding of food entrainment.

Therapeutic hypothermia and outcome in hyponatraemic encephalopathy secondary to maternal water intoxication

Misguided encouragement to consume large volumes of water during labour for pain relief results in dilutional hyponatraemia in mothers and their babies presenting with neurological dysfunction. We report three babies who were encephalopathic with seizures in the background of hyponatraemia secondary to maternal ingestion of large volumes of water and mild perinatal asphyxia. All babies underwent therapeutic hypothermia in addition to sodium supplementation with fluid restriction. Their neurodevelopment was appropriate for age. This case series highlights the dilemma that could arise with hyponatraemic encephalopathy and mild perinatal asphyxia in the first 6 hours of life, which is the window of opportunity for therapeutic hypothermia for hypoxic-ischaemic encephalopathy. It is important to educate pregnant mothers in labour on the adverse effects of excessive fluid ingestion.

Distribution of plasma copeptin levels and influence of obesity in children and adolescents

In recent years, a more stable AVP surrogate, called copeptin, has been used as an adjuvant diagnostic tool for dysnatremia in adults and appears to be promising even in the pediatric age. The aim of this study is to present the distribution of plasma copeptin in a large pediatric cohort and to observe the influence of fluid consumption and obesity on its values. A cohort of 128 children and adolescents was divided into two groups on the basis of nocturnal deprivation (group A) or free access to oral fluids in the 6–8 h before blood collection (group B). At all distribution percentiles, copeptin levels were higher (p < 0.0001) in group A, as were plasma sodium levels and osmolality (p = 0.02 and p = 0.008, respectively). The influence of BMI on copeptin levels was investigated by dividing the cohort into nonobese (group C) and obese children and adolescents (group D). Copeptin levels were higher in group D (p = 0.04).Conclusion: The measurement of copeptin could represent a useful tool for the diagnostic pathway of dysnatremic conditions, but its interpretation should take into consideration the state of hydration. Furthermore, it could also be a promising marker for obesity and metabolic syndrome, although this hypothesis needs further studies to be confirmed. What is Known:• Copeptin use as a diagnostic tool in AVP-related disorders, such as diabetes insipidus or syndrome of inappropriate secretion of antidiuretic hormone, is well established in adults• In pediatric age, few studies are available, but the preliminary data, including our previous study, seems to be promising. What is New:• In this study, we represent the distribution of copeptin levels in a pediatric cohort and show the significant influence of fluid ingestion on its plasma levels.• Also BMI seems to be a significant variable on copeptin levels and may be used as an obesity marker in pediatric age

Diversification of leech proboscis structure according to prey ingestion behavior

Background Adaptive radiation is a phenomenon in which various organs are diversified morphologically or functionally as animals adapt to environmental inputs such as diet and circumstance. Although previous studies have addressed changes caused by various external pressures, the evidence for variation in invertebrates is not well known. Leeches comprise a carnivorous or ectoparasitic group of animals that feed on a wide range of prey. They exhibit a corresponding variety of ingestion behaviors and morphological diversity of mouthparts and gut specializations. However, research on the diversity of ingestion behaviors and the internal structure of feeding organs in leeches is little known. In this study, we use histological analyses, fluorescent labeling and immunohistochemistry to reveal the detailed proboscis structure in the family Glossiphoniidae, while also suggesting the diversification of proboscises.Results We identified the feeding behavior of rhynchobdellid leeches, which have the proboscises. Alboglossiphonia sp. swallows prey whole using its proboscis, whereas other leeches exhibit typical fluid-sucking behavior. Glossiphoniid leeches exhibit fluid ingestion behavior along with clear arrangement of longitudinal muscles, circular muscles surrounding the lumen, and radial muscles, while Alboglossiphonia sp., which displays macrophagous ingestion like salifid Barbronia sp., has a partial circular muscle distribution and spacious lumen that extends to longitudinal muscle layer. To address whether the different feeding behaviors are intrinsic, we investigated the behavioral patterns and muscle arrangements in the earlier developmental stage of glossiphoniid leeches. Juvenile Glossiphoniidae including the Alboglossiphonia sp. exhibit the fluid ingestion behavior and have the proboscis with the compartmentalized muscle layers.Conclusions Genetic, morphological and behavioral differences between juvenile and adult stages of Alboglossiphonia sp. suggest their adult feeding biology has diverged from ancestral glossiphoniid leeches, while retaining developmental vestiges of the typical juvenile feeding morphology currently observed across Glossiphoniidae. This study provides the characteristics of leeches with specific ingestion behaviors, and a comparison of structural differences that serves as the first evidence of the proboscis diversification.

Diversification of Leech Proboscis Structure According to Prey Ingestion Behavior

Background Adaptive radiation is a phenomenon in which various organs, depending on their diet and circumstance, are diversified morphologically or functionally as animals adapt to the environment. Although previous studies on changes caused by various external pressures have been well studied, the evidence for variation in invertebrates is not well known. We used freshwater leeches as an invertebrate model to observe their specific trophic niche and diversity of ingestion organ. Our results show convergent evolution according to structural changes through a representative species Alboglossiphonia sp., and the origin from common ancestor due to the remaining fluid ingestion behavior of the larval stages as a vestige.Results We identified the feeding behavior of rhynchobdellid leeches, which have the proboscis. Alboglossiphonia sp. swallows the entire prey using its proboscis, whereas proboscis leeches exhibit typical fluid-sucking behavior. We observed that proboscis of fluid-sucking leeches encompasses compartmentalized and dense muscle layers. In contrast, macrophagous leeches have relatively simple esophagus structures. To address whether the different feeding behaviors were intrinsic, we investigated the behavioral pattern and muscle arrangement in the earlier developmental stage of rhynchobdellid leeches. Interestingly, juveniles of the macrophagous leech as well as fluid-sucking leeches have the proboscis with the compartmentalized muscle layers and exhibit fluid-sucking behaviorsConclusions Animals have adapted various ways to obtain the energy needed for their survival. Diversification and evolution of ingestion methods across species further exhibit the functional morphology of the ingestion organ. However, information on ingestion behavior and internal structure is still lack and unclear, especially in invertebrate models. Our results suggest that the proboscis leeches have originated from the common fluid-sucking glossiphoniid ancestor and species diversification has led to modifications in the structure of the feeding tube. Together, leeches represent a comparative model for esophagus development according to the ingestion pattern based on diverse muscular arrangement in proboscis.

Thirst as an ingestive behavior: A brief review on physiology and assessment

Background: Thirst is a sensation normally aroused by a lack of water and associated with a desire to drink more fluid. Aim: The aims of this brief review are twofold: (a) to summarize the thirst mechanism in how it is initiated and diminished, and (b) to describe techniques to assess human thirst accurately in a variety of situations. Discussion: Thirst is maintained via a feedback-controlled mechanism, regulated by central and peripheral factors, as well as social and psychological cues. Most studies of thirst have focused on the initiation of water intake and the neural mechanisms responsible for this vital behavior. Less attention has been paid to the stimuli and mechanisms that terminate a bout of drinking and limit fluid ingestion, such as oropharyngeal and gastric signals, coupled with osmotic sensations. Thirst perception is typically assessed by subjective ratings using a variety of questionnaires, rankings, or visual analog scales. However, the appropriate perceptual tool may not always be used for the correct assessment of thirst perception. Conclusions: In considering the many factors involved in thirst arousal and inhibition, similar questions need to be considered for the correct assessment of this ingestive behavior.