Studies of the small bowel surface by scanning electron microscopy in infants with persistent diarrhea

Fagundes-Neto, Ulysses; Martini-Costa, S. De; Pedroso, Margareth Zabeu; Scaletsky, Isabel C. A.

doi:10.1590/s0100-879x2000001200006

Cited by 25 publications

(16 citation statements)

References 20 publications

(16 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Alterations in small bowell could justify the extension of the diarrheiogenic process (6,16,17) . There are evidences that EAEC can colonize both, the small bowell and colonic mucosa, but there may be variations among different strains (22,23,24,45,46) .…”

Section: Discussionmentioning

confidence: 99%

“…Human and animal studies indicate that EAEC is able to bind to jejunal, ileal and colonic epithelium (23,40) . Several studies have demonstrated different degrees of alterations in the small bowel mucosa (16,17) due to persistent diarrhea. Enteric pathogens commonly cause illness by damaging the cells of the villous tip or secreting toxins, which bind to the enterocytes.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Pathophysiology of enteroaggregative Escherichia coli infection: an experimental model utilizing transmission electron microscopy

Andrade¹,

Freymüller

Fagundes-Neto³

2010

Arq. Gastroenterol.

View full text Add to dashboard Cite

-Context -Enteroaggregative Escherichia coli strains have been associated with persistent diarrhea in several developing countries. In vivo procedures with animal models as rat, rabbit and gnotobiotic piglets intestinal loops, in vitro assays with cellular lines like T84, Caco 2, HT29, HeLa e HEp-2 and in vitro organ culture with intestinal fragments have been applied to study these bacteria and their pathogenicity. Objectives -The present experimental research assessed the pathogenic interactions of three enteroaggregative Escherichia coli strains, using the in vitro organ culture, in order to observe and compare alterations in different regions of both, the ileal and the colonic mucosa. Methods -This study applied intestinal fragments from terminal ileum and colon that were excised from pediatric and adult patients that underwent colonoscopic procedures. Tissue was fixed for transmission electron microscopic study. Each bacterium was tested with three intestinal fragments for each region. Results -Enteroaggregative Escherichia coli strains colonized and provoked citotoxic effects in the ileal and colonic mucosa. Total or partial villi destruction, vacuolization of basal cytoplasm of the enterocytes, epithelium detachment, derangement of the structure and epithelial cell extrusion in ileal mucosa could explain the perpetuation of the diarrhea. Bacterial aggregates were seen in intestinal lumen associated with mucus and cellular debris and in the intercellular spaces of the destroyed epithelium, suggesting bacterial invasion that seemed to be secondary to the destruction of the tissue. Conclusions -Pathogenesis of persistent diarrhea should include alterations in the small bowel structures where the digestive-absorptive functions take place. In the colonic mucosa the inflammatory lesions could explain the occurrence of colitis.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Pathophysiology of enteroaggregative Escherichia coli infection: an experimental model utilizing transmission electron microscopy

Andrade¹,

Freymüller

Fagundes-Neto³

2010

Arq. Gastroenterol.

View full text Add to dashboard Cite

show abstract

“…However, a wide variety of post-PD pathological changes have been described by fairly small studies [33][34][35] . These studies indicate important fi ndings suggestive of chronic infl ammation and impaired mucosal integrity.…”

Section: Pathogenesis Of Pdmentioning

confidence: 99%

Persistent Diarrhea in Developing Countries

Bhutta¹

2005

Ann Nestlé [Engl]

View full text Add to dashboard Cite

Globally diarrheal diseases account for almost a fifth of all deaths of children under 5 years, with an estimated 2.2 million deaths annually. Of these deaths, a significant proportion are related to episodes of persistent diarrhea (PD; defined as diarrhea of >14 days with growth faltering). PD has been shown to identify children with a substantially increased diarrheal burden. These account for 36–54% of all diarrhea-related deaths. Although the exact pathogenesis of PD remains unclear, most episodes are related to prior acute infectious diarrhea with prolongation of the most recent episode. This may be related to several host factors such as preexisting undernutrition, micronutrient deficiency, immune deficiency and inappropriate therapy of the most recent acute diarrheal episode. The common final event appears to be prolonged intestinal mucosal injury and ineffective repair. In contrast to post-infectious PD, some infants may have severe intractable diarrhea due to a variety of disorders, many of which have a hereditary basis. These now form the dominant type of prolonged diarrhea in developed countries. The management of PD depends upon close attention to nutritional rehabilitation and early recognition of complications. Although a variety of pathogens have been associated with PD, there is little role for oral antimicrobial therapy in the routine treatment of PD. However, attention to rehydration, appropriate screening and treatment of systemic infections and enteral nutrition rehabilitation with easily digestible diets are critical in managing such children, frequently in ambulatory settings. Administration of zinc and vitamin A may shorten the duration of PD and also help reduce recurrences. However, the most important preventive strategies for PD are exclusive breastfeeding in the first 6 months of life, continued breast feeding for 2 years with appropriate complementary feeding and optimal management of acute diarrheal episodes.

show abstract

“…Uma grande quantidade de muco recobrindo a superfície epitelial do jejuno foi observada na maioria dos pacientes, e, em alguns deles, foi caracterizada a existência de uma crosta mucofibrinosa em contato direto com os enterócitos. Isso muito provavelmente foi o que causou, por processo obstrutivo, um grave prejuízo na absorção dos nutrientes da dieta, contribuindo, dessa forma, para a perpetuação da síndrome de má absorção, descrita na quase totalidade dos pacientes investigados 29 . Os pacientes manifestaram alergia às proteínas heterólogas, tais como do leite de vaca e soja, intolerância à lactose e aos monossacarídeos da dieta, além de colite confirmada pelo estudo da biópsia retal 29 .…”

Section: Fisiopatologiaunclassified

Persistent diarrhea: still an important challenge for the pediatrician

Andrade¹,

Fagundes-Neto²

2011

J Pediatr (Rio J)

View full text Add to dashboard Cite

Objective: To provide recent guidelines to reduce the incidence of diarrheal diseases. We discuss the definition, clinical aspects, pathophysiology, diagnosis, management, and prevention of persistent diarrhea.Sources: Electronic search of the MEDLINE database, Google search. Summary of the findings:Acute diarrhea may be caused by a variety of agents, including bacterial, viral, and protozoan pathogens. The top priority in treatment of diarrhea is replacement of fluid and electrolytes losses, particularly at the acute stage, and, under certain circumstances, eradication of the enteropathogenic agent. On the other hand, treatment of persistent diarrhea should focus on prevention and management of food intolerance and malnutrition.Conclusions: Promotion of breastfeeding, adequate interventions in the treatment of acute diarrheal episodes, introduction of safe dietary strategies for prevention of malnutrition, and improvements in sanitation and hygiene conditions, including sewage and clean water, are essential measures for the reduction of diarrheal morbidity and mortality rates in children under 5 years of age.J Pediatr (Rio J). 2011;87(3):199-205: Malnutrition, morbidity, mortality, diarrhea, food hypersensitivity, breastfeeding. ResumoObjetivo: Fornecer as diretrizes mais recentes de diminuição da incidência da doença diarreica, abordando os aspectos clínicos, a etiologia, a fisiopatologia, o diagnóstico, o manejo terapêutico e a profilaxia da diarreia persistente. Fontes dos dados:Busca eletrônica de dados recentes na base de dados MEDLINE, e também usando a ferramenta Google. Síntese dos dados:Existem vários possíveis agentes etiológicos envolvidos, incluindo vírus, bactérias e parasitas. O tratamento deve ser voltado para a dieta, além da reposição das perdas hidroeletrolíticas, especialmente durante a fase aguda da diarreia, para evitar seu prolongamento. Na grande maioria dos episódios, os antimicrobianos não estão indicados. Por outro lado, o tratamento da diarreia persistente deve ser reforçado no sentido de evitar as intolerâncias alimentares e a desnutrição. Conclusões:O estímulo ao aleitamento materno, a introdução de estratégias alimentares seguras no sentido de evitar a desnutrição proteico-calórica, a abordagem adequada do episódio agudo e a melhoria das condições sanitárias e de higiene são medidas a serem estimuladas com o objetivo de diminuir a morbimortalidade pela doença diarreica em crianças menores de 5 anos de idade ao redor do mundo.J Pediatr (Rio J). 2011;87(3):199-205: Desnutrição, morbidade, mortalidade, diarreia, hipersensibilidade alimentar, aleitamento materno.

show abstract

Studies of the small bowel surface by scanning electron microscopy in infants with persistent diarrhea

Cited by 25 publications

References 20 publications

Pathophysiology of enteroaggregative Escherichia coli infection: an experimental model utilizing transmission electron microscopy

Pathophysiology of enteroaggregative Escherichia coli infection: an experimental model utilizing transmission electron microscopy

Persistent Diarrhea in Developing Countries

Persistent diarrhea: still an important challenge for the pediatrician

Contact Info

Product

Resources

About