IBD-Like Features in Syndromic Diarrhea/Trichohepatoenteric Syndrome.

BACKGROUND: Very early onset inflammatory bowel disease (VEOIBD) (inflammatory bowel disease [IBD] before 6 years of age) may manifest as a monogenic disease affecting the gastrointestinal tract. Syndromic diarrhea/trichohepatoenteric syndrome (SD/THE), a rare disorder caused by alteration of a complex involved in RNA degradation, has been reported to present with some degree of colitis and in some cases an IBD-like presentation. METHODS: We reviewed clinical and biological data of 4 previously published cases and added detailed data of 2 new cases of SD/THE with an IBD-like presentation. RESULTS: All the 6 patients presented with typical intractable diarrhea and hair abnormalities. The colon was affected in all of the patients: 1 had ileitis, 2 had panenteritis, and 2 presented with perianal disease. Fecal calprotectin level and erythrosedimentation rate were elevated in 2 cases each. All the therapeutic classes of IBD treatment (mesalazine, steroids, immunomodulators, and biological therapy) were used in the 6 cases. In 2 patients, treatment had no effect. Three showed a partial effect, and 1 patient sustained only a transient effect. CONCLUSIONS: SD/THE can have a similar presentation as VEOIBD, often as pancolitis. IBD treatments appear to have little efficacy for SD/THE, suggesting a different pathogenesis for the IBD-like features in SD/THE compared with classical IBD.

MYO5B and bile salt export pump contribute to cholestatic liver disorder in microvillous inclusion disease.

UNLABELLED: Microvillous inclusion disease (MVID) is a congenital disorder of the enterocyte related to mutations in the MYO5B gene, leading to intractable diarrhea often necessitating intestinal transplantation (ITx). Among our cohort of 28 MVID patients, 8 developed a cholestatic liver disease akin to progressive familial intrahepatic cholestasis (PFIC). Our aim was to investigate the mechanisms by which MYO5B mutations affect hepatic biliary function and lead to cholestasis in MVID patients. Clinical and biological features and outcome were reviewed. Pretransplant liver biopsies were analyzed by immunostaining and electron microscopy. Cholestasis occurred before (n = 5) or after (n = 3) ITx and was characterized by intermittent jaundice, intractable pruritus, increased serum bile acid (BA) levels, and normal gamma-glutamyl transpeptidase activity. Liver histology showed canalicular cholestasis, mild-to-moderate fibrosis, and ultrastructural abnormalities of bile canaliculi. Portal fibrosis progressed in 5 patients. No mutation in ABCB11/BSEP or ATP8B1/FIC1 genes were identified. Immunohistochemical studies demonstrated abnormal cytoplasmic distribution of MYO5B, RAB11A, and BSEP in hepatocytes. Interruption of enterohepatic BA cycling after partial external biliary diversion or graft removal proved the most effective to ensure long-term remission. CONCLUSION: MVID patients are at risk of developing a PFIC-like liver disease that may hamper outcome after ITx. Our results suggest that cholestasis in MVID patients results from (1) impairment of the MYO5B/RAB11A apical recycling endosome pathway in hepatocytes, (2) altered targeting of BSEP to the canalicular membrane, and (3) increased ileal BA absorption. Because cholestasis worsens after ITx, indication of a combined liver ITx should be discussed in MVID patients with severe cholestasis. Future studies will need to address more specifically the effect of MYO5B dysfunction in BA homeostasis.

Tricho-hepato-enteric syndrome (THE-S): two cases and review of the literature.

UNLABELLED: Tricho-hepato-enteric syndrome (THE-S) is characterized by severe infantile diarrhea, failure to thrive, dysmorphism, woolly hair, and immune or hepatic dysfunction. We report two cases of East Asian descent with THE-S who had remained undiagnosed despite extensive investigations but were diagnosed on whole exome sequencing (WES). Both cases presented with chronic diarrhea, failure to thrive, and recurrent infections. Case 1 had posteriorly rotated low set ears, mild retrognathia, and fine curly hypopigmented hair. She was managed with prolonged total parenteral nutrition and intravenous immunoglobulin infusions. Case 2 had sparse coarse brown hair as well as multiple lentigines and café-au-lait macules. She was managed with amino acid-based formula. For both cases, routine investigations were inconclusive. WES in both cases showed biallelic truncating mutations in TTC37 (c.3507T>G;p.Y1169X and c.3601C>T;p.R1201X in case 1 and c.3507T>G;p.Y1169X and c.154G>T;p.E52X in case 2), suggesting a diagnosis of THE-S. CONCLUSION: We present novel mutations in the TTC37 gene in two individuals of East Asian descent with the rare THE-S, detected by WES. Future identification of patients with THE-S and establishing genotype-phenotype correlations will aid in counseling the patients and their families. WHAT IS KNOWN: • Tricho-Hepato-Enteric syndrome (THE-S) is characterized by severe infantile diarrhea, failure to thrive, dysmorphism, woolly hair, and immune or hepatic dysfunction. • Complex patients with diagnostic dilemmas undergo extensive investigations. What is New: • This is a report of novel mutations in TTC37 in individuals of East Asian descent. • Whole exome sequencing (WES) can be useful in certain complex cases with diagnostic dilemmas.

Functional consequences of EpCam mutation in mice and men.

Congenital tufting enteropathy (CTE) is a severe diarrheal disease of infancy characterized by villous changes and epithelial tufts. We previously identified mutations in epithelial cell adhesion molecule (EpCAM) as the cause of CTE. We developed an in vivo mouse model of CTE based on EpCAM mutations found in patients with the aim to further elucidate the in vivo role of EpCAM and allow for a direct comparison to human CTE. Using Cre-LoxP recombination technology, we generated a construct lacking exon 4 in Epcam. Epcam(Δ4/Δ4) mice and CTE patient intestinal tissue integrity was analyzed by histology using both light immunohistochemistry and electron microscopy. Epcam(Δ4/Δ4) mice demonstrate neonatal lethality and growth retardation with pathological features, including epithelial tufts, enterocyte crowding, altered desmosomes, and intercellular gaps, similar to human CTE patients. Mutant EpCAM protein is present at low levels and is mislocalized in the intestine of Epcam(Δ4/Δ4) mice and CTE patients. Deletion of exon 4 was found to decrease expression of both EpCAM and claudin-7 causing a loss of colocalization, functionally disrupting the EpCAM/claudin-7 complex, a finding for the first time confirmed in CTE patients. Furthermore, compared with unaffected mice, mutation of Epcam leads to enhanced permeability and intestinal cell migration, uncovering underlying disease mechanisms.

A novel nonsense mutation in the EpCAM gene in a patient with congenital tufting enteropathy.

OBJECTIVES: Tufting enteropathy (TE) is a classical congenital disorder of the intestinal mucosa causing protracted diarrhea in infancy as a result of a dysfunctional epithelial cell barrier, which is mainly caused by mutations in the EpCAM gene and expression of a nonfunctional epithelial cell adhesion molecule in the intestine. We report here a novel nonsense mutation in a patient suspected of having TE, resulting in a complete absence of EpCAM in duodenal enterocytes. METHODS: A patient presenting with congenital diarrhea and suspected of having TE was screened for EpCAM mutations, and duodenal biopsies were stained for EpCAM using immunohistochemistry analysis. RESULTS: We identified a novel homozygous nonsense mutation in the EpCAM gene in a patient suspected of having TE, causing a complete loss of EpCAM expression in duodenal enterocytes. CONCLUSIONS: With screening analysis for EpCAM mutations and immunohistochemistry for EpCAM expression in duodenal enterocytes, we found a novel homozygous mutation in a patient with classical protracted diarrhea in infancy finally diagnosed as TE, which results in a complete absence of EpCAM and in dysfunctional barrier formation in duodenal enterocytes.

UNC45A deficiency causes microvillus inclusion disease-like phenotype by impairing myosin VB-dependent apical trafficking.

Variants in the UNC45A cochaperone have been recently associated with a syndrome combining diarrhea, cholestasis, deafness, and bone fragility. Yet the mechanism underlying intestinal failure in UNC45A deficiency remains unclear. Here, biallelic variants in UNC45A were identified by next-generation sequencing in 6 patients with congenital diarrhea. Corroborating in silico prediction, variants either abolished UNC45A expression or altered protein conformation. Myosin VB was identified by mass spectrometry as client of the UNC45A chaperone and was found misfolded in UNC45AKO Caco-2 cells. In keeping with impaired myosin VB function, UNC45AKO Caco-2 cells showed abnormal epithelial morphogenesis that was restored by full-length UNC45A, but not by mutant alleles. Patients and UNC45AKO 3D organoids displayed altered luminal development and microvillus inclusions, while 2D cultures revealed Rab11 and apical transporter mislocalization as well as sparse and disorganized microvilli. All those features resembled the subcellular abnormalities observed in duodenal biopsies from patients with microvillus inclusion disease. Finally, microvillus inclusions and shortened microvilli were evidenced in enterocytes from unc45a-deficient zebrafish. Taken together, our results provide evidence that UNC45A plays an essential role in epithelial morphogenesis through its cochaperone function of myosin VB and that UNC45A loss causes a variant of microvillus inclusion disease.

Aberrant Epithelial Differentiation Contributes to Pathogenesis in a Murine Model of Congenital Tufting Enteropathy.

BACKGROUND & AIMS: Congenital tufting enteropathy (CTE) is an intractable diarrheal disease of infancy caused by mutations of epithelial cell adhesion molecule (EpCAM). The cellular and molecular basis of CTE pathology has been elusive. We hypothesized that the loss of EpCAM in CTE results in altered lineage differentiation and defects in absorptive enterocytes thereby contributing to CTE pathogenesis. METHODS: Intestine and colon from mice expressing a CTE-associated mutant form of EpCAM (mutant mice) were evaluated for specific markers by quantitative real-time polymerase chain reaction, Western blotting, and immunostaining. Body weight, blood glucose, and intestinal enzyme activity were also investigated. Enteroids derived from mutant mice were used to assess whether the decreased census of major secretory cells could be rescued. RESULTS: Mutant mice exhibited alterations in brush-border ultrastructure, function, disaccharidase activity, and glucose absorption, potentially contributing to nutrient malabsorption and impaired weight gain. Altered cell differentiation in mutant mice led to decreased enteroendocrine cells and increased numbers of nonsecretory cells, though the hypertrophied absorptive enterocytes lacked key features, causing brush border malfunction. Further, treatment with the Notch signaling inhibitor, DAPT, increased the numbers of major secretory cell types in mutant enteroids (graphical abstract 1). CONCLUSIONS: Alterations in intestinal epithelial cell differentiation in mutant mice favor an increase in absorptive cells at the expense of major secretory cells. Although the proportion of absorptive enterocytes is increased, they lack key functional properties. We conclude that these effects underlie pathogenic features of CTE such as malabsorption and diarrhea, and ultimately the failure to thrive seen in patients.

Microvillous inclusion disease: a clinicopathologic study of 17 cases from the UK.

BACKGROUND: Microvillous inclusion disease (MVID) is a rare congenital disease producing intractable secretory diarrhea in early infancy. It is characterized by diffuse intestinal villous atrophy with no inflammatory reaction. Ultrastructural identification of apical microvillous inclusions in the surface enterocytes is diagnostic. However, there is difficulty in the diagnosis of MVID due to the existence of variants (e.g., microvillous dystrophy), possible disease resolution, and tissue orientation for electron microscopy (EM). The authors analyzed materials from 4 patients with MVID from a single institution. The morphologic features, distribution of lesions, biomarkers, and complementary ultrastructural characteristics were studied. DESIGN: Materials of MVID cases were collected from 6 different hospitals in the United Kingdom between 1990 and 2008. Epidemiological data, including age range, median, mode, sex ratios, and follow-up, were retrieved. All intestinal biopsy specimens were analyzed histologically, histochemically (for PAS, n = 17), immunohistochemically (for CD10, n = 2 and polyclonal CEA, n = 4), and ultrastructurally (n = 9). RESULTS: Ultrastructurally, apical microvillous inclusions in surface enterocytes in duodenal biopsies were identified in all cases, while 1 case had variant morphology (microvillous dystrophy and very occasionally atypical microvillous inclusions). Tissue orientation for EM was supportive for identification of inclusions in apical enterocytes. Morphologically, a bubbly vacuolated appearance of the apical cytoplasm with extensive or patchy absence of the brush border with occasional cytoplasm inclusions was observed in the enterocytes. Some of these changes vaguely resembled gastric mucin cell metaplasia. Architecturally, villous blunting with either crypt hypoplasia or hyperplasia and absence of inflammation were common findings. The epithelial changes were also found in colon biopsies. PAS, CD10, and p-CEA showed a bright apical cytoplasmic blush/staining, which correlated ultrastructurally with apical granules with inclusions of variable electron density in all cases. These stains also highlighted the targetoid inclusions. CONCLUSION: Besides electron microscopy identification of inclusions, the light microscopic morphological features together with the biomarker studies highlighting the apical cytoplasmic blush are quite unique and diagnostic of MVID. Furthermore, it is the opinion of the authors that a diagnosis of MVID can be made without electron microscopy.

Loss of HAI-2 in mice with decreased prostasin activity leads to an early-onset intestinal failure resembling congenital tufting enteropathy.

Prostasin (CAP1/PRSS8) is a glycosylphosphatidylinositol (GPI)-anchored serine protease that is essential for epithelial development and overall survival in mice. Prostasin is regulated primarily by the transmembrane serine protease inhibitor, hepatocyte growth factor activator inhibitor (HAI)-2, and loss of HAI-2 function leads to early embryonic lethality in mice due to an unregulated prostasin activity. We have recently reported that critical in vivo functions of prostasin can be performed by proteolytically-inactive or zymogen-locked variants of the protease. Here we show that the zymogen form of prostasin does not bind to HAI-2 and, as a result, loss of HAI-2 does not affect prenatal development and survival of mice expressing only zymogen-locked variant of prostasin (Prss8 R44Q). Indeed, HAI-2-deficient mice homozygous for R44Q mutation (Spint2-/-;Prss8R44Q/R44Q) are born in the expected numbers and do not exhibit any obvious developmental abnormality at birth. However, postnatal growth in these mice is severely impaired and they all die within 4 to 7 days after birth due to a critical failure in the development of small and large intestines, characterized by a widespread villous atrophy, tufted villi, near-complete loss of mucin-producing goblet cells, loss of colonic crypt structure, and bleeding into the intestinal lumen. Intestines of Spint2-/-;Prss8R44Q/R44Q mice showed altered expression of epithelial junctional proteins, including reduced levels of EpCAM, E-cadherin, occludin, claudin-1 and -7, as well as an increased level of claudin-4, indicating that the loss of HAI-2 compromises intestinal epithelial barrier function. Our data indicate that the loss of HAI-2 in Prss8R44Q/R44Q mice leads to development of progressive intestinal failure that at both histological and molecular level bears a striking resemblance to human congenital tufting enteropathy, and may provide important clues for understanding and treating this debilitating human disease.

In Vivo DNA Re-replication Elicits Lethal Tissue Dysplasias.

Mammalian DNA replication origins are "licensed" by the loading of DNA helicases, a reaction that is mediated by CDC6 and CDT1 proteins. After initiation of DNA synthesis, CDC6 and CDT1 are inhibited to prevent origin reactivation and DNA overreplication before cell division. CDC6 and CDT1 are highly expressed in many types of cancer cells, but the impact of their deregulated expression had not been investigated in vivo. Here, we have generated mice strains that allow the conditional overexpression of both proteins. Adult mice were unharmed by the individual overexpression of either CDC6 or CDT1, but their combined deregulation led to DNA re-replication in progenitor cells and lethal tissue dysplasias. This study offers mechanistic insights into the necessary cooperation between CDC6 and CDT1 for facilitation of origin reactivation and describes the physiological consequences of DNA overreplication.

The Association Between Fecal Biomarkers of Environmental Enteropathy and Rotavirus Vaccine Response in Nicaraguan Infants.

BACKGROUND: Environmental enteropathy (EE) is a common intestinal condition among children living in low- and middle-income countries and is associated with diminished enteric immunity to gastrointestinal pathogens, and possibly to oral vaccine antigens. The goal of this study was to examine associations between biomarkers of EE and immunogenicity to the pentavalent rotavirus vaccine (RV5). METHODS: Infants were recruited 1 day before their first RV5 immunization in León, Nicaragua, from public health rosters. Infants provided a preimmunization blood and stool sample, and a second blood sample 1 month after receipt of RV5. We measured immunoglobin A (IgA) seroconversion to the first dose of RV5 and concentrations of 4 previously identified fecal biomarkers of EE (alpha-1 antitrypsin, neopterin, myeloperoxidase and calprotectin). We then assessed associations between concentrations of these biomarkers, both individually and as combined scores, and seroconversion to the first dose of RV5. RESULTS: Of the 43 enrolled infants, 24 (56%) seroconverted after the first dose of RV5. As compared with infants who seroconverted, those who did not seroconvert had higher median concentrations of both myeloperoxidase (3.1 vs. 1.1 µg/mL, P = 0.002) and calprotectin (199.1 vs. 156.2 µg/mL, P = 0.03). Further, those who did not seroconvert had a higher median combined score of the 4 biomarkers as compared with those who seroconverted (6.5 vs. 4.5, P = 0.017). CONCLUSIONS: We found an association between biomarkers of EE and seroconversion to the first dose of RV5. It is possible that interventions that prevent or ameliorate EE may also improve oral rotavirus vaccine response.

Contractile forces at tricellular contacts modulate epithelial organization and monolayer integrity.

Monolayered epithelia are composed of tight cell assemblies that ensure polarized exchanges. EpCAM, an unconventional epithelial-specific cell adhesion molecule, is assumed to modulate epithelial morphogenesis in animal models, but little is known regarding its cellular functions. Inspired by the characterization of cellular defects in a rare EpCAM-related human intestinal disease, we find that the absence of EpCAM in enterocytes results in an aberrant apical domain. In the course of this pathological state, apical translocation towards tricellular contacts (TCs) occurs with striking tight junction belt displacement. These unusual cell organization and intestinal tissue defects are driven by the loss of actomyosin network homoeostasis and contractile activity clustering at TCs, yet is reversed by myosin-II inhibitor treatment. This study reveals that adequate distribution of cortical tension is crucial for individual cell organization, but also for epithelial monolayer maintenance. Our data suggest that EpCAM modulation protects against epithelial dysplasia and stabilizes human tissue architecture.

Pathogenesis of rotavirus diarrhea.

Rotavirus diarrhea is a major cause of infantile gastroenteritis worldwide. This review is mainly devoted to the effects of Rotavirus on intestinal epithelial transport and to the pathophysiological mechanisms proposed to underlie the intestinal fluid secretion caused by the virus.

Nitrogen balance during recovery from secretory diarrhea of cholera in children.

This study describes nitrogen balance in children during recovery from severe cholera (bacteriologically confirmed). The subjects were six male children aged 12 to 24 months and weighing 6.29 to 9.86 kg (on recovery). They initially presented with dehydration and base deficit acidosis due to acute watery diarrhea. Nitrogen balance promptly improved with milk feeding even before diarrhea was fully controlled and irrespective of the clinical severity of the disease. There was no increase in stool volume and systemic acid base status remained unaffected when milk feeding was introduced. There was little nitrogen loss in the stool and the apparent absorption of protein was substantial. The negative nitrogen balance that occurred was largely due to the lack of intake. Early feeding and liberal intake appears to produce a more favorable impact than the cautious introduction of food. The common practice of restricting food during recovery from acute diarrhea is inappropriate in cholera.

Carbohydrate malabsorption in infants with rotavirus diarrhea.

We studied a group of patients with rotavirus diarrhea to determine the association of carbohydrate malabsorption during diarrhea with the degree of acidosis and severity of purging. Unlike enterotoxigenic diarrhea in which the metabolic acidosis is due to loss of bicarbonate in an alkaline stool, patients with rotavirus develop a metabolic acidosis while passing an acid stool with little detectable bicarbonate. Also unlike enterotoxigenic diarrhea, rotavirus stool contains large quantities of reducing substances suggesting significant carbohydrate malabsorption. Our findings are consistent with the hypothesis that carbohydrate malabsorption is an important secondary pathophysiological mechanism in the rotavirus diarrhea syndrome. This model for rotavirus diarrhea helps to explain the electrolyte and acid-base pattern of the rotavirus stool and stresses the importance of further nutrition balance studies to determine the optimal dietary management of patients with rotavirus diarrhea.

Zinc and copper balance studies in infants receiving total parenteral nutrition.

To determine the adequacy of zinc and copper supplementation for infants receiving total parenteral nutrition (TPN), we performed 24-h balance studies in infants with diarrhea and infants who had recently undergone surgery. Measurements were made at base line, 1, and 2 wk. Mean serum Zn and Cu levels of the diarrhea group remained normal and were low in the postoperative group but normalized over the study period. Mean 24-h Zn and Cu balances were positive in infants with diarrhea and negative in postoperative infants. The high Zn and Cu content in the gastrointestinal fluid loss associated with surgery may have accounted in part for this finding. Normal serum levels of Zn and Cu did not guarantee positive balance. No significant changes were found in serum albumin, alkaline phosphatase, or ceruloplasmin. The current Zn and Cu recommendations may be appropriate only for hospitalized infants who have no excessive gastrointestinal fluid losses.

Breast-feeding and food intake among children with acute diarrheal disease.

To quantitate reduced food intake during diarrhea and to assess possible means of promoting such intake, the 24-hr food and breast milk intakes of 41 children 6 to 35 months divided into three groups were measured. The energy and protein intake of 15 children hospitalized with acute watery diarrhea averaged 75 kcal/kg and 0.96 g/kg, respectively. The energy and protein consumption of another group of 15 children with diarrhea whose mothers received intensive education to promote food intake during hospitalization averaged 60.9 kcal/kg and 0.70 g/kg, respectively. These intake levels were significantly lower than 129.9 kcal/kg and 1.89 g/kg observed among healthy control children. These results suggest that child anorexia may be an important cause of reduced food intake during diarrhea. Anorexia was not overcome with intensive educational efforts. Breast milk was found to be important nutrient source with breast-fed children better protected against reduced intake during diarrhea.

PIP: The 24-hour food and breast milk intakes of 41 children age 6 to 35 months (divided into 3 groups) were measured in order to quantitate reduced food intake during diarrhea and to assess possible means of promoting such intake. The children had attended the International Center for Diarrheal Disease Research, Bangladesh situated in Matlab thana. 1 group of 15 children received routine hospital care for diarrheal illness, including oral hydration. The mothers of a 2nd group of 15 children received intensive dietary education in addition to routine diarrhea therapy for the child. A 3rd group consisted of 11 healthy control children who accompanied their mothers to Matlab for surgical family planning services. The energy and protein intake of the 15 hospitalized children averaged 75/kcal/kg and 0.96 g/kg, respectively. The energy and protein consumption of the children whose mothers received intensive education averaged 60.9 kcal/kg and 0.70 k/kg, respectively. These intake levels were significantly lower than 129.9 kcal/kg and 1.89 g/kg observed among the control children. The findings suggest that child anorexia may be an important cause of reduced food intake during diarrhea, and intensive educational efforts failed to overcome anorexia. Breast milk was found to be an important nutrient source with breast-fed children better protected against reduced intake during diarrhea.

Oral copper supplementation: effect on copper and zinc balance during acute gastroenteritis in infants.

To evaluate the effect of copper supplementation during recovery from acute diarrhea, we randomly assigned 14 hospitalized infants to receive either 80 micrograms copper sulfate.kg body wt-1.d-1 or a placebo. Metabolic balance and plasma copper and zinc concentrations were measured before randomization (period 1) and 6 d after admission (period 2). Fifteen control subjects were studied after respiratory illness. Fecal copper was not affected by supplementation; fecal zinc during period 2 rose significantly only in the copper-supplemented group. Copper retention was significantly higher in the supplemented infants; plasma concentrations increased for period 2 but were similar to those in the placebo group. Zinc concentrations improved over time in both groups but zinc retention was higher in the placebo group for period 2. A significant interference by copper supplementation on zinc absorption was noted. Copper supplementation during the early phase of recovery from diarrhea is not recommended.

Factors affecting the integrity of the intestinal mucosa of Gambian children.

The interrelationship between diarrhea, malnutrition, and small bowel integrity was investigated prospectively in 68 Gambian infants aged 0-18 mo. Profiles of growth and morbidity were recorded for 8 mo. Each month intestinal permeability was measured by the differential uptake of orally administered lactulose (L) and mannitol (M). In well infants the mean L:M ratio was 0.42 (range 0.11-1.42). This ratio was increased slightly for underweight (60-80% wt for age) infants (mean 0.52) but considerably for those with marasmus (less than 60% wt for age) (mean 1.3, p less than 0.001), for those with acute or chronic diarrhea (mean 1.0 and 2.85, respectively; p less than 0.001), or with measles (mean 1.4, p less than 0.001). Sequential studies of ward patients with malnutrition and diarrhea showed a rapid fall in L:M ratios with resolution of diarrhea. These studies suggest that damage to the small intestine may play an important part in the development of infant malnutrition in The Gambia.

A critique of oral therapy of dehydration due to diarrheal syndromes.

PIP: Under the circumstances of limited health resources and immediate need for preventing the dehydration associated with diarrhea in infants, breastfeeding should be encouraged throughout the diarrheal episode. When this is not possible because of cessation or failure of lactation, an oral electrolyte solution should be administered. It should be sterile and provide a quantity of electrolytes not greatly in excess of 30 mEq/liter of sodium and potassium. There should be little possibility of an error in the dilution of the mixture if it is to be supplied in powdered form. Milk should be reintroduced after 24 hours and the electrolyte mix rapidly discontinued so as to minimize nutritional deficits. If no such electrolyte mixture is available, it is reasonable to alternate feedings of commercial soft drinks or bland teas with milk feedings. There should be specific instructions that the infant should be brought to the hydration center if more than 3 sequential feedings are lost by vomiting, if fever is present, or it the stools exceed the volume of 3 feedings. In general, dehydration of less than 5% of body weight can be managed by this program in the house, dehydration greater than 5% but less than 10% requires supervision by health authorities, and dehydration greater than 10% requires intravenous therapy in a hydration center. In those countries with cholera and during epidemics of shigellosis or enterotoxigenic Escherichia coli, solutions containing 90 mEq/liter of sodium should be given under ambulatory supervision. This solution should be discontinued when fecal losses moderate (less than 60 ml/kg/day) and the lower electrolyte solution (30 mEq/liter) substituted.^ieng