The effect of phospholipase A2 on bacterial translocation in a cell culture model

The activity of phospholipase (PL)A2 is elevated in the intestinal epithelia of patients with inflammatory bowel disease (IBD). Recently, we reported that lysophosphatidylcholine (L-PC), the PLA2 hydrolysis product of phosphatidylcholine (PC), stimulates bacterial translocation (BT) in an enterocyte cell-culture model. These two observations stimulated us to examine the effects of extracellular PLA2 on intestinal epithelial permeability. Human Caco-2 enterocytes were grown to confluence on porous filters in the apical chamber of a two-chamber cell-culture system. Monolayer integrity and tight-junction permeability were measured by dextran blue (DB) permeability and transepithelial electric resistance (TEER). Monolayers were treated with PC, L-PC, or PLA2 with and without PC. The magnitude of BT was determined 2 h after treatment by adding Escherichia coli to the apical chamber followed by quantitatively culturing basal chamber samples. Thin-layer chromatography (TLC) was utilized to verify PLA2 hydrolysis of PC to L-PC. Statistical analysis was performed by one-way analysis of variance. The magnitude of BT across monolayers pretreated with PLA2 + PC significantly increased compared to either PC or PLA2 (6.83 +/- 0.069, 2.41 +/- 0.46, and 3.06 +/- 1.14 log10 colony forming units/ml, respectively, P < 0.05). Absence of DB-permeability in any group confirmed monolayer integrity. TLC of PL samples harvested from the apical monolayer surface confirmed PC hydrolysis. PLA2 mediates hydrolysis of PC to L-PC when both are applied to the apical surface of cultured enterocyte monolayers, resulting in increased BT and increased TEER with no damage to monolayer integrity. These observations may have implications in the pathogenesis and treatment strategies for IBD.

Confirmation of translocated gastrointestinal bacteria in a neonatal model

PURPOSE

The hypothesis that enteric bacteria translocate from the gastrointestinal (GI) tract to extraintestinal sites has been extensively studied. However, definitive evidence that spontaneous bacterial translocation and dissemination from the GI tract to extraintestinal sites occur in a neonatal model has been lacking. The aim of this study was to confirm this phenomenon by tracking enterally administered, plasmid-labeled bacteria to extraintestinal sites.

MATERIALS AND METHODS

Escherichia coli 07:K1 (E. coli K1) with and without a nontransferable, ampicillin resistance plasmid (pGEM-7) were used in this study. Newborn New Zealand white rabbit pups were separated into three treatment groups: transformed E. coli K1 (E. coli K1 + pGEM-7, n = 20), nontransformed E. coli K1 (n = 12), and control pups (no bacteria, n = 7). Pups were enterally fed 10% Formulac solution supplemented with a suspension of bacteria respective to their group. After the pups fed twice daily for 2 days, representative tissue specimens from the small bowel (SB), mesenteric lymph nodes (MLNs), spleen (SPL), and liver (LIV) were aseptically harvested and tested for culture growth in ampicillin-supplemented medium.

RESULTS

Positive growths of plasmid-induced ampicillin-resistant bacteria were detected in tissue specimens harvested from rabbits fed transformed E. coli K1, but were not detected in the other groups.

CONCLUSION

This experiment demonstrated conclusively that transformed E. coli K1 fed to healthy rabbit pups spontaneously translocated from the intestinal lumen and subsequently disseminated to the mesenteric lymph nodes, spleen, and liver.

Specialty networking in pediatric surgery: a paradigm for the future of academic surgery

OBJECTIVE

To review retrospectively a 4-year experience with pediatric surgical networking at a major academic medical center in the Midwest.

BACKGROUND

The growth of managed care in the United States during the past decade has had a major impact on the practice of medicine in general, but especially on academic medicine. In some academic medical centers, the loss of market share has not only affected clinical activity but has also compromised the educational and research missions of these institutions.

METHODS

At the authors' institution, a networking strategy in pediatric surgery was established in 1993 and implemented on July 1, 1994. In 1994, one new satellite practice was established; over the next 4 years, four additional practices were added, including one in another state. To assess the impact on financial status, clinical activity, education, and academic productivity, the following parameters were analyzed: gross and net revenue, surgical cases, clinic visits, ranking of the pediatric surgery residency, publications, grant support, and development and endowment funds.

RESULTS

Gross and net revenue increased from $3,273,000 and $302,000 in 1993 to $10,087,000 and $2,826,000, respectively, in 1998. Surgical cases and clinic visits increased from 1240 and 3751 in 1993 to 5872 and 11,604, respectively, in 1998. At the medical center's children's hospital, surgical cases and clinic visits increased from 1240 and 3751 to 2592 and 4729 during the same time period. During this 4-year period, the faculty increased from 4 to 11. Since 1997, the National Resident Matching Program has provided data on how pediatric surgery residency candidates ranked a training program. In 1997, this program received the second-most one to five rankings; in 1998, it tied for first. This exceeds the faculty's perception of previous years' rankings. Publications increased from 26 in 1993 to a peak number of 62 in 1996; in 1997 and 1998 the publications were 48 and 37, respectively. External grant support increased from $139,882 in 1993 to a total of $6,109,971 in 1998. Development and endowment funds increased from $103,559 in 1993 to $2,702,2777 in 1998.

CONCLUSIONS

Pediatric surgical networking at the authors' institution has had a markedly positive impact on finances, clinical activity, education, and academic productivity during a 4-year period. The residency training program appears to have improved in popularity among candidates, probably because of the increased referral of complex cases to the medical center from the various networking satellites. External grant support and basic laboratory research significantly increased, most likely because of the greater number of faculty with protected time for research recruited. Development and endowment funds dramatically grew because of the excellent fiscal health of the pediatric surgical program. This experience may serve as a model for other academic surgical specialties.

An analysis of the morbidity and mortality of short-bowel syndrome in the pediatric age group

Twenty-two children with short-bowel syndrome (SBS) were treated at the C. S. Mott Children's Hospital in the University of Michigan Medical Center between June 1983 and May 1993. Definition of SBS was loss of 70% or more of the total small bowel. Seventeen of these children are currently alive, a 77% survival rate. Patients were followed for a mean of 1,148 days. The mean age of SBS development was 71 days of life. The only predictive indicator of patient survival was direct bilirubin levels. Sixty-seven percent of the children died if they had a direct bilirubin of > 4 mg/dl > or = 6 months duration.

Prenatal diagnosis of congenital cystic adenomatoid malformation and its postnatal presentation, surgical indications, and natural history

BACKGROUND/PURPOSE

Regression of a cystic adenomatoid malformation (CAM) in a fetus is well described. Little, however, is known about the postnatal course of these infants. This study attempts to correlate the prenatal course of CAMs with postnatal symptoms, radiological manifestations, and need for surgery.

METHODS

The clinical course of patients with a CAM diagnosed prenatally were retrospectively reviewed. Inclusion in the study required a prenatal ultrasound scan documenting a CAM.

RESULTS

Over 10 years, 14 patients with a CAM were diagnosed prenatally. Six (43%) showed a partial in utero regression. Four patients were symptomatic at birth and underwent a resection as newborns. Ten patients were asymptomatic at birth, and eight of these had normal chest x-rays. Elective resection has been performed in 3 of these 10, and two additional children are scheduled to undergo an excision near 1 year of age. The remaining five patients have undergone follow-up nonoperatively for a mean of 36 +/- 15 months. Of the seven asymptomatic patients not undergoing immediate surgery, only one has shown a slight postnatal regression, despite five of these showing regression in utero. None have become symptomatic.

CONCLUSIONS

The results suggest that regression of a CAM on prenatal ultrasound scan is common, but this process does not continue after birth. A normal chest x-ray does not indicate complete regression of a CAM; a computed tomography (CT) scan is required to evaluate such patients, and will generally demonstrate a CAM. Asymptomatic patients with a CAM may be followed up nonoperatively with no apparent adverse effects. The decision and timing of an excision in an asymptomatic patient remains controversial among pediatric surgeons.

The effect of mucin on bacterial translocation in I-407 fetal and Caco-2 adult enterocyte cultured cell lines

Although the intestinal mucosa forms a crucial barrier between the host and the environment, bacterial translocation (BT) occurs frequently in neonates and may be a source of sepsis. The intestinal mucous gel layer is thought to be a vital component of the gut barrier and is composed, in part, of a family of glycoproteins known as mucins. Our aim was to study the effects of mucin on BT in an enterocyte cell-culture model using a fetal (I-407) and an adult (Caco-2) intestinal cell line. I-407 and Caco-2 cells were grown to confluence on porous filters in a two-chamber Transwell system. The integrity of the monolayers was confirmed by transepithelial electrical resistance (TEER) and permeability using the macromolecule dextran blue. Cells were treated with mucin (40 mg/ml) prior to inoculation of 1 x 10(6) Escherichia coli C25. The magnitude of BT was determined quantitatively by culturing the samples from the basal chamber of the wells and was expressed as log 10 [Colony Forming Units (CFU)/ml]. Statistical analysis was performed by the Mann-Whitney U test with statistical significance at P < 0.05. Mucin inhibited BT across both fetal and adult cultured enterocyte monolayers; however, the inhibitory effect was less on the fetal cells compared to the adult cells. Dextran-blue studies showed that monolayers were intact throughout the experiments. Despite 98% inhibition of BT, mucin had a statistically significant effect on post-bacterial inoculation TEER in Caco-2 cells and no effect in I-407 cells. The ability of mucin, a mucous-barrier glycoprotein, to inhibit BT across immature intestinal enterocytes, as in the neonate, may be diminished compared to mature adult enterocytes.

The effect of phospholipids and mucin on bacterial internalization in an enterocyte-cell culture model

A primary component of the intestinal mucous layer that functions as a barrier to luminal bacteria is mucin, a high-molecular-weight glucoprotein. In addition, the mucous layer also contains other important elements such as phospholipids (PLs), which may effect bacterial translocation (BTL). It has been reported that mucin inhibits Escherichia coli translocation; however, the effect of PLs on intestinal permeability is still controversial. We have recently reported that the concentration of mucous PLs is higher in neonatal as compared to adult rabbits. The functional significance of these biochemical differences on BTL remains to be determined. The aim of this study was to evaluate the effect of PL and mucin composition on BTL in a human enterocyte-cell culture model. Human enterocyte Caco-2 cells were seeded in 24-well tissue-culture plates and grown for 14 days to confluence. The monolayers were pretreated with phosphate buffered saline as control, 10 mg/ml or 20 mg/ml mucin, 0. 5 mM or 1.0 mM PL mixture based on neonatal (NPL) and adult (APL) composition, and 10 mg/ml mucin with 0.5 mM either APL or NPL mixtures 30 min before a 120-min incubation period at 37 degrees C with 10(8) colony forming units (CFU) of E. coli C25. Non-internalized bacteria were killed by the addition of gentamicin. Internalized bacteria were quantified by counting CFU from enterocyte-cell lysates grown on MacConkey's agar. Mucin inhibited bacterial internalization, while both compositions of PLs promoted it. Mucin added to the PL solution also diminished the stimulatory effect of PLs on bacterial internalization. These results indicate that the increased concentration of PLs found in the intestinal mucous layer of neonates, and/or the alteration in the balance between PLs and mucin, may play a role in the increased BTL seen in neonates.

Enterocolitis

Enterocolitis continues to be the major cause of morbidity and mortality in patients with Hirschsprung's disease. The exact etiology of Hirschsprung's-associated enterocolitis is not known. This review focuses on the clinical aspects, etiology, and therapy of Hirschsprung's-associated enterocolitis.

The lateral approach for open splenectomy

BACKGROUND

Laparoscopic splenectomy (LS) has been used increasingly to treat children with hematologic disorders and has been reported to have advantages over open splenectomy performed through a standard vertical or subcostal incision. The authors perform open splenectomy (OS) through a lateral, muscle-splitting approach, and believe their approach is more reasonable in comparison with LS.

METHODS

Thirty-nine consecutive open splenectomies performed between 1991 and 1995 were reviewed retrospectively and compared with recent reports of LS. The series included 24 boys and 15 girls with an average age of 9 years and average weight of 37.5 kg. Indications included immune thrombocytopenic purpura (n = 20), hereditary spherocytosis (n = 18), and sickle cell anemia (n = 1). The operation was performed with the child in the lateral decubitus position through a left upper abdominal muscle-splitting incision (off the 11th rib), sparing the rectus muscle.

RESULTS

All 39 cases were completed without intraoperative complications with an average surgical time of 98.0 minutes (range, 30 to 302). The average surgical blood loss was 89 mL (range, 10 to 300). The children started feeding an average of 1.2 days (range, 0 to 4) postoperatively, were on a regular diet at an average of 2.0 days (range, 1 to 6) postoperatively, and had an average length of stay of 2.7 days (range, 1 to 6). There was no mortality or morbidity.

CONCLUSIONS

Open lateral splenectomy is performed with shorter surgical times, less blood loss, an excellent cosmetic result, no complications, and a length of stay comparable to any of the published series on laparoscopic splenectomy in children. This approach provides a reasonable basis for comparison with laparoscopic splenectomy.

The association of large ovarian cysts with cloacal exstrophy

BACKGROUND/PURPOSE

Cloacal exstrophy can now be managed with excellent survival rates and reasonable long-term outcomes with many of these patients living into their late teens and early adulthood. In this report, the authors describe for the first time the association of large ovarian cysts with cloacal exstrophy.

METHODS

From 1974 to 1996, 12 patients with cloacal exstrophy have been treated at C.S. Mott Children's Hospital. Massive ovarian cysts developed in four of these. These patients represent the subjects of this study.

RESULTS

All four patients have been followed up beyond puberty and massive ovarian cysts have developed, which have caused significant morbidity. Three patients have required surgical intervention. All the patients had reached menarche before the development of the cysts. In all cases, the presentation was severe pelvic pain. Urinary tract obstruction from the large pelvic cysts developed in three of the four. The cysts were bilateral in three of four patients and measured 8 to 10 cm in diameter on ultrasound scan or computed tomography (CT). Cyst aspiration was attempted in two cases and was unsuccessful. Three of the four patients have required bilateral salpingo-oophorectomy. The indications for surgery were uncontrollable pelvic pain in one and urinary obstruction and uncontrollable pelvic pain in two. Surgical findings demonstrated massive thin-walled cysts with essentially no normal ovarian tissue in association with duplicated mullerian structures. The pathology findings were corpus luteal cyst in two and mucinous cystadenoma in one. The fourth patient with an 8- x 10-cm unilateral cyst is being followed up.

CONCLUSIONS

The authors have described, for the first time, the association of massive ovarian cysts with cloacal exstrophy. These cysts can lead to severe pelvic pain and urinary tract obstruction. Bilateral oophorectomy has been required in most of these patients.

Firearm ownership in households with children

BACKGROUND/PURPOSE

Increased morbidity and mortality rates in children injured by firearms has been well documented during this past decade. The aim of this study was to determine the socioeconomic factors affecting firearm ownership in families with children living in suburban/rural versus inner-city environments, and to identify predictors of firearm ownership in these families.

METHODS

Parents of children less than 19 years old seen in a suburban (n = 751) or inner-city hospital (n = 406) anonymously completed a questionnaire regarding firearm ownership.

RESULTS

Firearm ownership was 54% in rural locations, versus 18% among inner-city residents (P< .05). Firearm ownership in white households was 45% versus 20% in African-American households (P< .05). Mean number of all types of firearms in white households was 3.38 versus 1.78 in black households (P< .001). Firearm ownership was 19% in the less than $20,000 income bracket, significantly lower than households with greater incomes, and was significantly lower in households in which parents had the least education (19.7%) versus those with college degrees (38.5%; P< .05). Firearm owners of rifles and shotguns significantly more often cited hunting, collection, and target shooting as reasons for owning firearms, in contrast to revolver owners who cited protection and collection as reasons for firearm ownership (P < .05).

CONCLUSIONS

Firearm ownership is higher in rural, caucasian versus inner-city African-American residents and is significantly less in households with lower income and educational levels. Significant predictors for firearm ownership were number of parents in households, educational level of parents, and population of residence.

Surgical treatment of gastroesophageal reflux in children: a combined hospital study of 7467 patients

OBJECTIVE

To review retrospectively the combined clinical experience with the surgical treatment of persistently symptomatic gastroesophageal reflux (SGER) in childhood from seven large children's surgery centers in the United States.

DESIGN

During the past 20 years, 7467 children <18 years of age underwent antireflux operations for SGER at the seven participating hospitals. Fifty-six percent were neurologically normal (NN) and 44% were neurologically impaired (NI). The most frequent diagnostic studies were upper gastrointestinal series (68%), esophageal pH monitoring (54%), gastric emptying study (32%), and esophagoscopy (25%). The age at operation was under 12 months in 40% and 1 to 10 years in 48%. The type of fundoplication was Nissen (64%), Thal (34%), and Toupet (1.5%). A gastric emptying procedure was performed on 11.5% of NN patients and 40% of NI patients. Laparoscopic fundoplication was performed on 2.6% of patients.

RESULTS

Good to excellent results were achieved in 95% of NN and 84.6% of NI patients. Major complications occurred in 4.2% of NN and 12.8% of NI patients. The most frequent complications were recurrent reflux attributable to wrap disruption (7.1%), respiratory (4.4%), gas bloat (3.6%), and intestinal obstruction (2.6%). Postoperative death occurred in 0.07% of NN and 0.8% of NI patients. Reoperation was performed in 3.6% of NN and 11.8% of NI patients. The results and complications were similar among the participating hospitals and did not seem related to the type of fundoplication used.

CONCLUSION

The excellent results (94% cure) and low morbidity with gastroesophageal fundoplication with or without a gastric emptying procedure from a large combined hospital study indicate that operation should be used early for SGER in NN children and to facilitate enteral feedings and care in NI children.

The effect of epidermal growth factor on bacterial translocation in newborn rabbits

PURPOSE

Epidermal growth factor (EGF), which is present in breast milk, has both trophic and maturational effects on intestinal mucosa. The aim of this study is to determine the effect of EGF on spontaneous intestinal bacterial translocation (BT) in formula-fed newborn rabbits, who have a high incidence of BT compared with breast-fed newborn rabbits.

METHODS

Sixty-one rabbit pups were divided into three groups: EGF(-), n=24, EGF(+), n=22, and breast-fed animals, n=15. Both the EGF(-) and EGF(+) groups were gavage fed a standard artificial formula three times daily. EGF was administered subcutaneously three times daily (1.5 microg/g body weight per day) in the EGF(+) group. The breast-fed group was fed by their mothers ad libitum. At 7 days of age, all rabbits were killed, and the mesenteric lymph nodes (MLN), liver, and spleen were cultured qualitatively for bacterial growth, while the cecum and ileum were quantitatively cultured. To determine the effect of EGF on mucus-producing cells, goblet cell numbers in the small intestine were quantified histologically.

RESULTS

There was no BT to MLN, spleen, or liver in the breast-fed group. The incidence of BT to MLN and spleen was significantly lower in the EGF(+) compared with EGF(-) group; (EGF[+]: MLN, 45%; spleen, 32%; Liver, 27%; EGF[-]: MLN, 79%; Spleen 67%; Liver 29%; in EGF[+] MLN and Spleen P<.05 vEGF[-]). There was no significant difference in cecal and ileal bacterial colonization between the EGF(+) and EGF(-) groups. The number of goblet cells in the small intestine was significantly lower in the EGF(-) group compared with the EGF(+) group as follows: EGF(+), 14+/-3; EGF(-), 9+/-3; breast-fed, 11+/-5 goblet cells per 100 epithelial cell nuclei; P=.013.

CONCLUSIONS

(1) EGF caused a significant decrease in spontaneous bacterial translocation in formula-fed newborn rabbits and was associated with an increase in the goblet cell number of the small intestine. (2) These changes occurred in spite of the fact that no changes in small bowel bacterial colonization were observed. (3) These results suggest, but do not prove, that EGF may provide protection for neonates from gut origin infection by improving the mucosal barrier function through increased goblet cell production, thus decreasing the incidence of spontaneous bacterial translocation in the newborn.

Long-term outcome for infants and children with sacrococcygeal teratoma: a report from the Childrens Cancer Group

BACKGROUND/PURPOSE

Sacrococcygeal teratomas (SCT) are a relatively uncommon tumor affecting neonates, infants, and children. This study was designed to determine the effect of therapy on the long-term outcome of neonates and children with sacrococcygeal teratomas (SCT).

METHODS

The authors conducted a retrospective review of children with SCT treated at 15 Childrens Cancer Group institutions from 1972 to 1994.

RESULTS

One hundred twenty-six children presented with SCT diagnosed prenatally (n = 32), at birth (n = 79), or later in infancy (n = 15). For neonates, complete resection was performed except in two babies with lethal associated defects. All others (n = 15) underwent resection at the age of diagnosis. Six had a sacral mass identified at birth but had delayed surgery (1.5 to 11 months) and of these, two were malignant. Resection was via sacral (n = 96) or abdominosacral (n = 28) approach. Histology showed mature teratoma (MT, 69%), immature teratoma (IT, 20%), or endodermal sinus tumor (EST, 11%) at presentation. Seven neonates (5.6%) died of perioperative complications, whereas the remaining 117 were available for long-term follow-up. Between 6 and 34 months postresection, recurrent disease developed in 9 of 80 MT patients (11%) followed-up for a mean of 5 years. Recurrent disease was MT (n = 2) and EST (n = 7). The recurrent EST patients were treated with adjuvant chemotherapy. Six are alive with mean follow-up of 114 months, whereas one with metastatic disease was lost to follow-up. Recurrence (MT) developed in only 1 of 24 IT patients, and all are alive and well at mean follow-up of 39 months. Patients presenting with EST (n = 13) underwent excision, with two dying from non-EST causes. Six EST patients received no chemotherapy, with two of the six (33%) experiencing recurrence within 11 months and both disease free after salvage chemotherapy. The remaining five EST patients received adjuvant chemotherapy; four are alive and one died of metastatic disease. Of the 18 EST patients followed-up after resection (presentation, 11, recurrent teratoma, 7), 16 (89%) are free of disease with a mean follow-up of 91 months.

CONCLUSIONS

(1) Benign teratomas have a significant recurrence rate mandating close follow-up for more than 3 years. (2) Surgical resection alone is adequate therapy for nonmetastatic malignant tumors. (3) Survival for malignant lesions with metastases is excellent with modern chemotherapy.

Immediate and long-term results of surgical management of low imperforate anus in girls

BACKGROUND

The majority of girls with imperforate anus are reported to have a malformation of the low variety. Despite this, much of the literature has focused on the more complex, high lesions.

METHODS

This study reviews our experience with 44 girls with low imperforate anus from a 22-year period.

RESULTS

The incidence of associated anomalies was 61%, which is higher than generally reported. All patients in the study had anal fistulae. Fifty-seven percent had perineal fistulae, 23% had fourchette fistulae, and 20% had vestibular fistulae. Cutback anoplasty was performed in 55%, Potts transfer anoplasty was used in 27%, and 18% of patients were treated with either limited posterior sagittal anorectoplasty or anterior sagittal anorectoplasty. Surgical complications were uncommon. Long-term follow-up was carried out by telephone survey. This showed 89% of the girls to be successfully toilet trained. However, 47% of patients experience at least occasional soilage or episodic fecal incontinence.

CONCLUSIONS

Low imperforate anus can be successfully treated using a variety of procedures without colostomy. Most girls with low imperforate anus are successfully toilet trained, but problems with continence persist in a significant number of these patients.

Changes, with age, in the phospholipid content of the intestinal mucus layer of the newborn rabbit

BACKGROUND/PURPOSE

The high incidence of bacterial translocation in newborns is thought to be caused, in part, by the immaturity of the intestinal mucosal barrier. Recently, intestinal mucus phospholipids (PL) have been reported to be important factors in the function of this mucosal barrier. The aim of this study was to quantify changes, with age, in the intestinal mucus PL of the newborn rabbit.

METHODS

Mucus was gently scraped from the small intestinal mucosal surface of rabbits of different ages (0, 7, 14, and 28 days old and adult; n = 6 for all groups). PL was extracted from the mucus and was separated by two-dimensional thin-layer chromatography. The isolated phospholipid spots were quantified for their phosphorus content.

RESULTS

Total PL content of the mucus decreased significantly with age (day 0, 21+/-2; day 7, 16+/-4; day 14, 9+/-3; day 28, 2+/-1; adult, 1+/-1 micromol/g wet mucus; P = .0001). Phosphatidylcholine and phosphatidylethanolamine levels in the adult rabbits were significantly lower in comparison with the 0-, 7-, and 14-day-old pups (P < .05). In contrast, lysophosphatidylcholine and lysophosphatidylethanolamine were significantly higher in the 28-day-old and adult rabbits in comparison with the 0-, 7-, and 14-day-old pups (P < .05). Phosphatidylinositol + phosphatidylserine levels in 7-day-old rabbits was significantly higher compared with adult rabbits. There was no significant difference in the composition of sphingomyeline between groups.

CONCLUSION

Significant changes in the content and composition of the intestinal mucus phospholipids were observed during the first month of life in rabbits.

Conservative management of mesenchymal hamartoma of the liver

The natural history of mesenchymal hamartoma of the liver is poorly understood. This case demonstrates the course of a biopsy-proven mesenchymal hamartoma using sequential computed tomography (CT) examinations. These CT scans show initial expansion of the lesion with subsequent involution. The spontaneous resolution in this patient suggests the possibility of conservative management of asymptomatic mesenchymal hamartomas. The case is presented, and the literature on mesenchymal hamartoma is reviewed.

Intestinal permeability to small- and large-molecular-weight substances in the newborn rabbit

BACKGROUND/PURPOSE

The authors have previously reported the occurrence of spontaneous bacterial translocation (BT) and its resolution with age in the newborn rabbit. They have also reported a close correlation between small bowel bacterial colonization (BC-SB) and BT at 1 week of age, suggesting that the presence of luminal bacteria and their production of endotoxins may increase the intestinal permeability. The aim of this study was to evaluate intestinal permeability to small and large molecules in the newborn rabbit and to correlate it with BT.

MATERIALS AND METHODS

New Zealand White rabbits (n = 96) 1, 7, 14, 21, and over 120 days (adult) of age were given either C14-labeled ethylene diamine tetraacetic acid (EDTA) (MW 290) or C14-Dextran (MW 70,000) via an orogastric tube at 1 mCi per 100 g of body weight. Five hours later, blood, urine, liver, and intestine were collected, and scintillation counting was performed after solubilization. In a separate series of rabbits (n = 136), the incidence of BT, BC-SB, and small intestinal surface area (SA) were measured.

RESULTS

Total permeability to Dextran decreased with age and was significantly reduced at 14 days of age. In contrast, total permeability to EDTA increased and was maximal in 7- to 14-day-old rabbits and began to decrease at 21 days of age. The incidence of BC-SB rapidly increased at 7 days of age and reached 100% at 14 days of age. The incidence of BT peaked at 7 days of life (30%) and then decreased with age. SA increased rapidly in the first 3 weeks and SA growth rate of 21-day-old rabbits was almost 1,400% compared with 1-day-old rabbits.

CONCLUSIONS

This study has shown an age-related reduction of intestinal permeability to large (Dextran) and small (EDTA) molecular weight particles. However, intestinal permeability to EDTA had a different pattern than Dextran, suggesting that there may be different mechanisms of intestinal permeability to different size molecules. Intestinal permeability to EDTA closely correlated with bacterial colonization and bacterial translocation, suggesting that changes in the intestinal bacterial environment may affect the intestinal permeability, possibly by activating the immune system secondary to increases in endotoxins and bacteria.

Efficacy of the straight endorectal pull-through in the management of familial adenomatous polyposis--a 16-year experience

From 1979 to 1995, 27 patients who had familial adenomatous polyposis (FAP) were treated at the authors' institution. Most patients (n = 23) presented as a result of a previous family history of FAP. Eighteen patients presented with symptomatic colonic disease that included bloody stools (n = 14), diarrhea (n = 10), and abdominal pain (n = 6). Treatment consisted of a total colectomy, rectal mucosectomy, and straight endorectal pull-through (ERPT) in 26 of 27 patients. One patient preferred to undergo an ileoanal J pouch reconstruction. A temporary diverting loop ileostomy was performed in 25 patients and closed at an average of 100 days after the ERPT. Follow-up has been achieved in 100% of the patients and ranges from 6 to 182 months with an average of 48 months. Postoperative complications included partial bowel obstruction (two patients, one requiring enterolysis); and mild pouchitis (one patient). Two of the 27 patients required proctectomy and permanent ileostomy procedures, one for rectal cancer that was present microscopically in the initial rectal specimen from the ERPT and the other because of recurrent anastomotic complications. No patient required revision of the straight pull-through to a pouch or takedown of the pull-through as a result of persistent diarrhea or dissatisfaction. All of the patients are continent, and 80% deny any soiling during bouts of gastroenteritis. The mean number of bowel movements reported was 10 per day at the first postoperative clinic visit with a gradual decreased to six per day after 2 years. Initial use of bulking (62%) and antimotility agents (88%) decreased significantly over the course of follow-up to 29% and 67%, respectively at the most recent follow-up (average, 48 months) of each patient. Pelvic sepsis, which occurs in 8% of most series of patients who have pouches, did not occur in any of our patients. Pouchitis, a common complication with pouches (23%), occurred in only one of the patients and was mild and easily treated medically. This series demonstrates that total colectomy with rectal mucosectomy and straight ERPT eliminates the risk of colorectal cancer and achieves continence with a low complication rate and excellent functional results and patient satisfaction.

Complications after gastric transposition in children

BACKGROUND AND OBJECTIVE

Esophagogastrostomy with gastric transposition, a procedure for replacement of the esophagus in cases of esophageal atresia, is increasing in popularity among pediatric surgeons. This study was undertaken to document the differences between postoperative complications in children and those reported in adults.

PATIENTS AND METHODS

The authors reviewed the medical records and radiologic images for details of complications in 6 children (5 boys and 1 girl) who underwent esophagogastrostomy with gastric transposition for esophageal atresia. Follow-up ranged from 18 months to 12 years. The observations were compared with complications in adults, as reported in the literature.

RESULTS

The complications of gastric transposition were classified as early (up to 1 month after surgery) of late (more than 1 month after surgery). They included anastomotic leak (in 1 patient), hernia (in 1) and recurrent structure (in 3). In 1 patient mediastinal abscess developed secondary to esophageal perforation, which occurred during a dilation procedure for stricture.

CONCLUSIONS

Postoperative complications of gastric transposition occur less commonly in children than in adults. Benign stricture, which may occur both early and late, is the most common problem.

Long-term stooling patterns in infants undergoing primary endorectal pull-through for Hirschsprung's disease

Primary endorectal pull-through (ERPT) has become an increasingly popular method of caring for neonates and young infants who have Hirschsprung's disease. This study evaluated the long-term stooling patterns and continence rates of patients who had a primary ERPT as a young infant. The records of 24 infants who underwent a primary ERPT for Hirschsprung's disease were reviewed. The patients' families (those patients over 3 years of age, n = 12) underwent a detailed interview that graded continence from 0 (poor) to 10 (normal). Mean age at ERPT was 15 +/- 17 days (range, 2 to 67). Mean follow-up was 1,036 +/- 614 days. Nine patients suffered from 20 episodes of enterocolitis. Stooling frequency declined rapidly in the first 6 months after the ERPT (r2 = 1.00) and more slowly after this time (r2 = 0.79). Continence was graded as normal (10) in one, good (6 to 9 points) in nine, and fair (1 to 5) in two patients, both of whom had total colonic disease. The authors conclude that a primary ERPT in the young infant who has Hirschsprung's disease can yield excellent results including normalization of stooling frequency and good to excellent levels of continence.

Use of cholecystokinin to prevent the development of parenteral nutrition-associated cholestasis

BACKGROUND

Neonates are at high risk for the development of parenteral nutrition-associated cholestasis when receiving a prolonged course of total parenteral nutrition (TPN). Although this cholestasis is of unknown etiology, it may result from a lack of gastrointestinal hormone formation, including cholecystokinin, which normally occurs after enteral feedings.

METHODS

Two groups of neonates were studied. The treatment group consisted of 21 consecutive, prospectively enlisted neonates receiving TPN for > 14 days. The nontreatment group consisted of 21 infants from the 2 years preceding the study who were matched to the treatment group by gestational age, diagnosis, and duration of TPN. The major outcome determinant was direct bilirubin. Cholestasis was defined as a direct bilirubin > 2.0 mg/dL and was considered severe if the direct bilirubin was > 5.0 mg/dL after other causes were ruled out.

RESULTS

The mean direct bilirubin levels in the nontreated group progressively rose over time, whereas the mean direct bilirubin the treated group remained level. The incidence of infants with a direct bilirubin > 2.0 mg/dL was 24% and 43% in the CCK+ and CCK- groups, respectively, and was not significant (p = .14). The percentage of infants with a direct bilirubin > 5.0 mg/dL was 9.5% and 38% in the treatment and nontreatment groups, respectively, and was significant, p = .015.

CONCLUSIONS

Levels of direct bilirubin were lower in the treated compared with the nontreated group. These findings suggest that cholecystokinin prophylaxis in high-risk neonates may help prevent the development of parenteral nutrition-associated cholestasis.