What are the global patterns of microplastic ingestion by fish? A scientometric review.

The billions of tons of plastic released into the environment mostly fragment into smaller particles that reach rivers and oceans, posing toxicity risks to aquatic organisms. As fish serve as excellent environmental indicator organisms, this study aims to comprehensively review and quantify published data regarding the abundance of microplastics (MPs) ingested by fish through scientometric analysis. Systematic analysis reveals that global aquatic ecosystems are contaminated by MPs, with the characteristics of these contaminants stemming from inadequate disposal management practices. The abundance of MPs was recorded in several fish species, notably Cyprinus carpio in natural environments and Danio rerio in controlled environments. According to the surveyed studies, laboratory experiments do not accurately represent the conditions found in natural environments. The results suggest that, in natural environments, the predominant colors of MPs are blue, black, and red. Fibers emerged as the most prevalent type, with polyethylene (PE) and polypropylene (PP) being the most frequently identified chemical compositions. On the other hand, laboratory studies showed that the spheres and fragments ingested were predominantly polystyrene (PS) green, followed by the colors blue and red. This discrepancy complicates drawing accurate conclusions regarding the actual effects of plastic particles on aquatic biota. Given the enduring presence of plastic in the environment, it is imperative to consider and implement environmental monitoring for effective, long-term management.

Fumonisin-containing diets decrease the metabolic activity of myenteric neurons in rats.

Fumonisins are naturally occurring mycotoxins that contaminate food for human and animal consumption. They have neurotoxic effects, but the mechanisms by which these toxins affect the nervous system are not fully known. In the present study, male Wistar rats were fed between 21 and 63 days of age with diets that contained fumonisins B1+B2 at 0, 1, and 4 mg/kg. The following variables were assessed: food consumption, growth, body weight gain, and blood parameters. Morphoquantitave analyses of the most metabolically active myenteric neurons were performed, detected by NADH-diaphorase activity. Nitrergic neurons were detected by NADPH-diaphorase activity. The fumonisin-containing diets did not significantly alter food consumption or the body or plasma parameters. These diets decreased the metabolic activity of jejunal myenteric neurons, reducing neuronal density of the most metabolic active neurons by 30.8% and the cell body area by 4.3%. The diets also decreased the cell body area of nitrergic neurons by 22.1%. The effects of fumonisin B1 on the respiratory metabolism of isolated mitochondria in the brain and liver were also assessed. A decrease in oxygen consumption up to a 29% in the brain and 38% in the liver was observed in mitochondrial isolates to which 50 µM fumonisin B1 was added. The decrease in respiratory activity that was triggered by exposure to fumonisins was related to the lower metabolic activity of myenteric neurons, which had a negative impact on neuroplasticity of the enteric nervous system.

Chronic ingestion of deoxynivalenol-contaminated diet dose-dependently decreases the area of myenteric neurons and gliocytes of rats.

BACKGROUND: Deoxynivalenol (DON), a mycotoxin produced by Fusarium spp., is commonly found in cereals ingested by humans and animals. Its ingestion is correlated with hepatic, hematologic, renal, splenic, cardiac, gastrointestinal, and neural damages, according to dose, duration of exposure and species. In this work, the effects of the ingestion of DON-contaminated diet at concentrations considered tolerable for human and animal intake were assessed. METHODS: Male Wistar rats aging 21 days were allotted to five groups that were given, for 42 days, diets contaminated with different concentrations of DON (0, 0.2, 0.75, 1.75, and 2 mg kg-1 of chow). Food ingestion, bodyweight, oxidative status and morphometric analyses of gliocytes, and neurons of jejunal myenteric ganglia were recorded. KEY RESULTS: At these concentrations, there was no food rejection, decrease in bodyweight gain, changes in oxidative status, or loss of either neurons or gliocytes. However, DON decreased gliocyte area, general neuronal population, nitrergic, cholinergic and NADH-diaphorase positive subpopulations and, as a result, ganglion area. CONCLUSIONS & INFERENCES: It was concluded that, even in the absence of visible effect, DON exposure reduces cell body area of gliocytes and neurons of the myenteric plexus of the rat jejunum.

Effect of fumonisin-containing diet on the myenteric plexus of the jejunum in rats.

Fumonisins are mycotoxins that naturally occur as contaminants in grains that are destined for animal and human consumption. These mycotoxins cause hepatotoxic, nephrotoxic, carcinogenic, teratogenic, immunotoxic, and neurotoxic effects in different intensities based on dose, time of exposure, and animal species. In the present study, male Wistar rats were fed between postnatal days 21 and 63 with diets that contained fumonisins B1+B2 at concentrations of 1 and 3mg/kg. The objective of the present study was to evaluate the effects of fumonisins on food intake, growth, weight gain, serum activity of the alanine aminotransferase and aspartate aminotransferase enzymes, and quantitative and morphometric parameters of myenteric neurons in the jejunum that are immunoreactive to HuC/D protein and neuronal nitric oxide synthase enzyme (nNOS). Diets that contained fumonisins did not significantly alter food intake or body and blood parameters. We did not observe significant differences in the neuronal density and proportion of nitrergic neurons but found a significant reduction of cell body areas in both neuronal populations. This study is the first to report the effects of fumonisins in the enteric nervous system. The possible mechanisms by which fumonisins impair neuronal development and the use of the enteric nervous system as a tool for the study of the neurotoxic effects of fumonisins are discussed. In conclusion, fumonisin-containing food negatively affected the growth of myenteric neurons.

Effect of administering a diet contamined with fumonisins on the kidneys of wistar rats / Efeito da administração de ração contaminada com a micotoxina fumonisinas sobre os rins de ratos wistar

Fumonisins (FBs) are mycotoxins produced by Fusarium molds. Several works have shown contamination of maize by this toxin. Fumonisin B1 (FB-1) is found in greatest proportion (about 70%), resistant to several industrialization processes. In that context, the objective of this work was to analyze the effect of administering a diet contaminated with FB- 1 on the morphophysiology of the kidneys of 21-day old male Wistar rats. The animals were divided into 2 groups: G0 (with animals receiving feed free of FBs) and G6 (6mg of FB1 kg-1 of feed). The diet was administered during 42 days. After that period, the animals were placed in metabolic cages for urine collection, blood was collected for analysis of plasma creatinine, and the kidneys were fixed and stained with Masson's trichrome. We observed that FB1 administration did not affect feed intake, body weight gain and animal growth. The normal levels of plasma creatinine suggest that the toxin did not lead to glomerular lesion. There was also no change in water intake, osmolarity and excretion of sodium in urine. However, there was a significant increase in urine volume and potassium excretion in urine, with mild tubulointerstitial changes in the outer cortex for the group receiving the mycotoxin.

Fumonisinas (FBs) são micotoxinas produzidas por fungos do gênero Fusarium. Diversos trabalhos demonstraram a contaminação do milho por essa toxina. A fumonisina B1 (FB-1) é encontrada em maior proporção (cerca de 70%), sendo resistente a vários processos de industrialização. De acordo com este contexto, o trabalho em foco teve como objetivo analisar o efeito da administração de dieta contaminada com FB-1 sobre a morfofisiologia renal de ratos Wistar machos, com 21 dias de idade. Os animais foram divididos em 2 grupos: G0 (ração isenta de FBs) e G6 (alimentados com 6mg de FB1 kg-1 de ração). A dieta foi administrada por 42 dias. Após esse período, os animais foram colocados em gaiolas metabólicas para coleta da urina, o sangue foi coletado para análise da creatinina plasmática, e os rins fixados e corados pelo Tricrômico de Masson. Observou-se que a administração de FB1 não afetou o consumo de ração, o ganho de peso e crescimento dos animais. A normalidade nos níveis da creatinina plasmática sugere que a toxina não induziu lesão glomerular. Não houve alteração na quantidade de água ingerida, na osmolaridade e na excreção urinária do sódio. No entanto houve aumento significativo no volume urinário e na excreção urinária do potássio e presença de alterações tubulointersticiais de intensidade leve no córtex externo, no grupo que recebeu a micotoxina.

Morphometric and quantitative study of the myenteric neurons of the stomach of malnourished aging rats.

In this work, two groups of Wistar rats were fed ad libitum, one with standard chow (22% protein) and the other with hypoproteic chow (8% protein), from the 210th to the 345th day of life. Compared to the animals fed with standard chow, the animals fed with hypoproteic chow exhibited hypophagia (ingestion about 30% lower), mean weight gain 4.46% lower, greater amount of retroperitoneal and peri-epididymal fat (19% on average), lower Lee index, decrease of total plasma proteins and plasma globulins and maintenance of plasma albumin. The quantitative and morphometric analysis of the NADH-diaphorase positive myenteric neurons yielded a larger number of small neurons and a smaller number of medium neurons in the animals subjected to the hypoproteic chow, demonstrating that the neuronal growth was affected by the diet. In the animals fed with hypoproteic chow, a 20% decrease in the NADH-diaphorase positive neurons of the forestomach and a 10% decrease in those of the glandular stomach were observed.

Evaluation of body growth and myoenteric neurons of Wistar rats after neonatal treatment with monosodium glutamate

This work aimed at evaluating how the neonatal treatment with monosodium glutamate reflects on body parameters and on myoenteric neurons of Wistar rats. Male rats were injected with monosodium glutamate during the first five postnatal days. Body growth was recorded until the age of 90 days, when the animals were killed. Fasting plasma glucose, caloric density and weight of organs were assayed. Gastric and duodenal whole-mounts stained with NADH diaphorase were observed for neuronal numbers and sizes. Growth, relative weight of organs and testicular caloric density of the injected rats were smaller than those of the controls, while their Lee index and relative fat content were greater. The number of duodenal neurons and the mean size of gastric neurons were smaller in the injected animals. These results are discussed in light of the endocrine, autonomic and behavioral changes stemming from the lesion of the hypothalamic arcuate nucleus by monosodium glutamate.

Avaliação do crescimento corporal e dos neurônios mioentéricos de ratos Wistar após tratamento neonatal com glutamato monossódico. Este trabalho objetivou avaliar como o tratamento neonatal com glutamato monossódico se reflete em parâmetros corporais e nos neurônios mioentéricos de ratos Wistar. Ratos machos foram injetados com glutamato monossódico durante os primeiros 5 dias após o nascimento. O crescimento corporal foi registrado até os 90 dias, quando os animais foram sacrificados. Glicose plasmática de jejum, densidade calórica e peso dos órgãos foram avaliados. Preparados de membrana gástricos e duodenais corados com NADH-diaforase foram observados quanto a número e tamanho dos neurônios. Crescimento, peso relativo dos órgãos e densidade calórica testicular dos ratos injetados foram menores que nos controles, enquanto o índice de Lee e o conteúdo relativo de gordura foram maiores. O número de neurônios duodenais e o tamanho médio dos neurônios gástricos foram menores nos animais injetados. Esses resultados são discutidos a luz das alterações endócrinas, autonômicas e comportamentais resultantes da lesão do núcleo arqueado hipotalâmico pelo glutamato monossódico.

Variação anatômica do músculo tibial anterior / Anatomical variation of tibialis anterior muscle

O músculo tibial anterior tem sido usado em muitas aplicações clínicas como um elemento de reconstrução, especialmente nas lesões do terço distal da perna. Este artigo descreve o achado de uma variação anatômica bilateral no músculo tibial anterior. Em um cadáver masculino de cor negra, com 53 anos de idade, em ambos os membros, o músculo tibial anterior estava fixado ao retináculo distal dos músculos extensores (fáscia do dorso do pé) e com um tendão supranumerário para a cabeça do primeiro osso metatarsal.

Variação anatômica do músculo grácil: relato de caso / Anatomical variation of the gracilis muscle: a case report

The gracilis muscle has very constant anatomy patterns. The removal of this muscle does not entail any important functional loss of the lower limb function. Therefore, the gracilis muscle has been used in many clinical settings as an element of reconstruction. This article reports a variation of the gracilis muscle anatomy. In a 53-year-old black man corpse, the right gracilis muscle was found divided proximally into two heads the originated separately from the pubic bone and joined 9 cm above knee joint. Onlu one tendon fixed the two heads distally at the tibia. In the left lower limb of the same corpse, the muscle had only one belly originated from the pubis, immediately lower to the pubic tubercle at the inferior ramus of the pubis.

Density and morphometry of myenteric neurons of the ileum of rats subjected to chronic alcoholism

This work verified the changes caused by ethanol ingestion on the myenteric neurons of the ileum of rats subjected to chronic alcoholism. Twenty rats (Rattus norvegicus) were divided in control (GC) and alcoholic (GA) groups during 210 days. The animals from group GA received sugar-cane brandy diluted to 30 GL and those from group GC received water. Both groups were fed with rodent chow ad libitum. The ileum was prepared as whole-mounts for neuronal staining according to Barbosa (1978) and Gabella (1979). The neurons were counted and the cell bodies were measured. The statistical analysis revealed a significant decrease in the number of large neurons in GA compared with GC, while there was a significant increase in the number of small neurons in GA. There was a smaller body growth in GA, thus causing a smaller spread of the nerve cells and a larger number of neurons evidenced by the techniques of Giemsa and NADH-diaphorase in the alcoholic animals than in the controls, and a decrease in the size of the cell bodies, evidenced by the increase in the proportion of small neurons and decrease in the proportion of large nerve cells.