Microvillus inclusion disease: a subtotal enterectomy as a bridge to transplantation

Diet management in congenital diarrheas and enteropathies - general concepts and disease-specific approach, a narrative review

Congenital diarrheas and enteropathies (CODE) are a group of rare, heterogenous, monogenic disorders that lead to chronic diarrhea in infancy. Definitive treatment is rarely available, and supportive treatment is the mainstay. Nutritional management in the form of either specialized formulas, restrictive diet, or parenteral nutrition support in CODE with poor enteral tolerance is the cornerstone of CODE treatment and long-term growth. The evidence to support the use of specific diet regimens and nutritional approaches in most CODE disorders is limited due to the rarity of these diseases and the scant published clinical experience. The goal of this review was to create a comprehensive guide for nutritional management in CODE, based on the currently available literature, disease mechanism, and the PediCODE group experience. Enteral diet management in CODE can be divided into 3 distinct conceptual frameworks: nutrient elimination, nutrient supplementation, and generalized nutrient restriction. Response to nutrient elimination or supplementation can lead to resolution or significant improvement in the chronic diarrhea of CODE and resumption of normal growth. This pattern can be seen in CODE due to carbohydrate malabsorption, defects in fat absorption, and occasionally in electrolyte transport defects. In contrast, general diet restriction is mainly supportive. However, occasionally it allows parenteral nutrition weaning or reduction over time, mainly in enteroendocrine defects and rarely in epithelial trafficking and polarity defects. Further research is required to better elucidate the role of diet in the treatment of CODE and the appropriate diet management for each disease.

Experimental Studies on the Impact of the Projected Ocean Acidification on Fish Survival, Health, Growth, and Meat Quality; Black Sea Bream (Acanthopagrus schlegelii), Physiological and Histological Studies

Simple Summary

This study’s data suggest that under the projected scenarios of ocean acidification by 2100 and beyond, significant negative impacts on growth, health, and meat quality are expected, particularly on black sea bream, and will be susceptible to the scientifically approved fish having a weaker resistance to diseases and environmental changes if CO₂ emissions in the atmosphere are not curbed. Knowing the expected consequences, mitigation measures are urgently needed.

Abstract

Acidification (OA), a global threat to the world’s oceans, is projected to significantly grow if CO₂ continues to be emitted into the atmosphere at high levels. This will result in a slight decrease in pH. Since the latter is a logarithmic scale of acidity, the higher acidic seawater is expected to have a tremendous impact on marine living resources in the long-term. An 8-week laboratory experiment was designed to assess the impact of the projected pH in 2100 and beyond on fish survival, health, growth, and fish meat quality. Two projected scenarios were simulated with the control treatment, in triplicates. The control treatment had a pH of 8.10, corresponding to a pCO₂ of 321.37 ± 11.48 µatm. The two projected scenarios, named Predict_A and Predict_B, had pH values of 7.80-pCO₂ = 749.12 ± 27.03 and 7.40-pCO₂ = 321.37 ± 11.48 µatm, respectively. The experiment was preceded by 2 weeks of acclimation. After the acclimation, 20 juvenile black sea breams (Acanthopagrus schlegelii) of 2.72 ± 0.01 g were used per tank. This species has been selected mainly due to its very high resistance to diseases and environmental changes, assuming that a weaker fish resistance will also be susceptibly affected. In all tanks, the fish were fed with the same commercial diet. The seawater’s physicochemical parameters were measured daily. Fish samples were subjected to physiological, histological, and biochemical analyses. Fish growth, feeding efficiency, protein efficiency ratio, and crude protein content were significantly decreased with a lower pH. Scanning electron microscopy revealed multiple atrophies of microvilli throughout the small intestine’s brush border in samples from Predict_A and Predict_B. This significantly reduced nutrient absorption, resulting in significantly lower feed efficiency, lower fish growth, and lower meat quality. As a result of an elevated pCO₂ in seawater, the fish eat more than normal but grow less than normal. Liver observation showed blood congestion, hemorrhage, necrosis, vacuolation of hepatocytes, and an increased number of Kupffer cells, which characterize liver damage. Transmission electron microscopy revealed an elongated and angular shape of the mitochondrion in the liver cell, with an abundance of peroxisomes, symptomatic of metabolic acidosis.

[Clinical features and MYO5B mutations of a family affected by microvillus inclusion disease]

Microvillus inclusion disease (MVID) is an autosomal recessive disorder caused by biallelic mutations in the MYO5B or STX3 gene. Refractory diarrhea and malabsorption are the main clinical manifestations. The aim of this study was to investigate the clinical features and MYO5B gene mutations of an infant with MVID. A 21-day-old female infant was referred to the hospital with the complaint of diarrhea for 20 days. On physical examination, growth retardation of the body weight and length was found along with moderately jaundiced skin and sclera. Breath sounds were clear in the two lungs and the heart sounds were normal. The abdomen was distended and the veins in the abdominal wall were observed. The liver and spleen were not palpable. Biochemical analysis revealed raised serum total bile acids, bilirubin, transaminases and γ-glutamyl transpeptidase while decreased levels of serum sodium, chloride, phosphate and magnesium. Blood gas analysis indicated metabolic acidosis. The preliminary diagnosis was congenital diarrhea, and thus parenteral nutrition was given along with other symptomatic and supportive measures. However, diarrhea, metabolic acidosis and electrolyte disturbance were intractable, and the cholestatic indices, including transaminases, γ-glutamyl transpeptidase, bilirubin and total bile acids, remained at increased levels. One month later, the patient was discharged and then lost contact. On genetic analysis, the infant was proved to be a compound heterozygote of the c.310+2Tdup and c.1966C>T(p.R656C) variants of the gene MYO5B, with c.310+2Tdup being a novel splice-site mutation. MVID was thus definitely diagnosed.