The role of luminal nutrients in intestinal injury from mesenteric reperfusion and platelet-activating factor in the developing rat

Necrotizing enterocolitis (NEC) develops primarily after the onset of enteral feeds in the premature infant. The purpose of this study was to evaluate the influence of intestinal luminal nutrients on histologic injury and the oxidant response in a rat model of NEC. On postnatal Days 10 and 35, Sprague-Dawley rats (total n = 81) underwent abdominal laparotomy. A control group received sham-injury only. The ischemia groups received a single intraluminal injection of 0.25 ml (Day 10) or 1.0 ml (Day 35) of lactose (8.6 g/dl), casein (2.2 g/dl), corn oil (4.4 g/dl), or infant formula (Similac; 20 g/dl). After injection of the nutrient solutions, ischemia groups underwent mesenteric occlusion for 1 hr and intraluminal injection of platelet-activating factor (50 microgram/kg). Necropsies were performed after 6 hr or at demise. Intestinal samples were taken for histology, total glutathione (GSH; an antioxidant), and conjugated dienes (a lipid peroxidation product). Histologic injury was scored from 0 (normal) to 5 (transmural necrosis). Microscopic injury scores in the oil group were significantly higher than the casein group (P < 0.05) and trended toward being higher in the formula group (P = 0.085) at age 10 days. Total GSH activity was significantly higher in the sham groups than all ischemia groups on Day 10 (P < 0.001) and than the corn oil group on Day 35 (P < 0.05). GSH activity did not differ among ischemia groups. Conjugated diene concentrations were significantly higher in the casein group than the lactose and sham groups at age 10 days (P < 0.05) only. We conclude that intraluminal lipids may augment intestinal ischemic injury in the newborn (age 10 days) but not the weanling rat. While oxygen-free radicals were present during injury, lipid peroxidation from oxygen radicals was not responsible for this increase in histologic injury.

Hydrometrocolpos and segmental colonic dilatation in a girl with megacystis-microcolon-intestinal hypoperistalsis syndrome

OBJECTIVE

To report a case of a newborn female infant noted to have features of the megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS) with the additional features of hydrometrocolpos and segmental colonic dilatation and review the literature.

METHODOLOGY

The details of the case were collated and compared with the previous published experience with this condition.

RESULTS

Thus far there have been 58 previous cases of MMIHS described, only four of which have had colonic dilatation. A number of concurrent anomalies have been described, but not the hydrometrocolpos or dysmorphic features seen in this patient.

CONCLUSION

This case appears to be MMIHS with additional features not previously recorded.

Clostridium difficile diarrhea: pathogenesis, epidemiology, and treatment

Clostridium difficile, the bacterium responsible for antibiotic-associated diarrhea and colitis, has become a significant cause of morbidity and prolonged hospital stays, largely because of the increasing use of broad-spectrum antibiotics. This gram-positive organism, which can lay dormant in its spore form in the environment for extended periods of time, proliferates in the colon when the normal colonic flora is compromised by antibiotic use. C. difficile produces intestinal inflammation and diarrhea through the elaboration of two protein exotoxins, toxin A and toxin B. The spectrum of clinical manifestations ranges from mild diarrhea that resolves with the cessation of the offending antibiotic, to fulminant pseudomembranous colitis complicated by megacolon and perforation. Our ability to meet the challenge offered by this organism has been enhanced by the development of new diagnostic modalities as well as the development of new therapeutic regimens. Through further investigation of the structure and function of toxins A and B and further study of the interaction of C. difficile with the normal colonic flora, advances will continue to be made in the prevention and treatment of antibiotic-associated colitis.

Pseudomembranous colitis following prophylactic antibiotic use in primary cesarean section

A report of a hospital outbreak of pseudomembranous colitis in three patients given prophylactic antibiotic therapy before and after primary cesarean section is presented. All patients shared the same ward and labor and delivery room, and the colitis occurred within an 8-day period. The diagnosis of pseudomembranous colitis was suspected clinically and confirmed by limited colonoscopy and biopsy followed by stool culture and toxin assay for Clostridium difficile. The high carrier rate of Clostridium difficile in the female urogenital tract and altered colonic motility during pregnancy, in addition to antibiotic use, may have contributed to the establishment of this disease. When diarrhea develops postoperatively in patients who have undergone cesarean section, pseudomembranous colitis as a potential serious complication must be kept in mind and necessary precautions taken to impede cross-contamination and development of secondary cases.

[Enteral yersiniosis--a serious disease? Current knowledge of clinical aspects, diagnosis and therapy]

Enteral yersiniosis is caused either by Y. enterocolitica 0-group I (syn. serotype 0:3) and 0-group V (syn. serotype 0:9) or Y. pseudotuberculosis type I-VI. The clinical symptoms are mostly like enteritis, enterocolitis, acute abdomen, mesenteric lymphadenitis, or ileitis terminalis. Post-infection reactions are possible like septicemia, arthritis and erythema nodosum. Only cultural and serological examinations confirm the diagnosis of enteral yersiniosis. In the judgement of serological results it is necessary to consider the cross-reactions of Y. enterocolitica 0-group V to Brucella abortus, Brucella melitensis and Brucella suis and also to the antigenic community of Y. pseudotuberculosis type II respectively IV to Salmonella group B respectively D. With exception of septicemia, it is not necessary to treat enteral yersiniosis with antibiotics.

Prevention of necrotising enteritis in Papua New Guinea by active immunisation

Necrotising enteritis (pig-bel) caused by Clostridium welchii type C is a major cause of illness and death in the Highlands of Papua New Guinea. In a controlled trial of active immunisation with a clostridial toxoid prepared from type-C cultures the incidence of pig-bel in over 2500 immunised children within 24 months of immunisation was less than an eighth of that in a control group. Necrotising enteritis in Papua New Guinea is now a preventable disease.