Coralline hydroxyapatite is a suitable bone graft substitute in an intra-articular goat defect model.

Intra-articular defects can be filled with an autologous bone graft taken from the iliac crest. This can be indicated after trauma or following correcting osteotomy. Patients may encounter donor site morbidity after this procedure. In this in vivo study, we studied if coralline hydroxyapatite (CHA) is a suitable material to replace autologous bone graft to fill a defect in the femoral trochlea of goats. CHA did not evoke any negative reaction in the synovium, and the articular cartilage was comparable to controls. In the bone graft group, we found scattered areas of (enchondral formed) bone. Most bone graft had been resorbed or remodeled, and the scarce remnants were incorporated into new bone. Resorption of CHA was limited or absent and most CHA was surrounded by new bone. In areas with fragmented CHA, close to the joint surface, numerous giant cells were found. The study shows that in this animal model, CHA inserted in a defect that directly communicates with the joint space incorporates into bone. This study did not show any negative effects of CHA in a joint environment.

Effect of bowel transection and fecal passage deprivation on the enteric nervous system in neonatal rats.

INTRODUCTION: A temporary stoma is a relatively common procedure at the neonatal age for a number of disorders. At birth, the enteric nervous system (ENS) is not fully developed; temporary colostomy causes morphological changes in the ENS. We studied whether transection of bowel or deprivation of stool is responsible for these changes. Moreover, reversibility of the ENS changes after stoma closure was investigated. METHODS: Male Lewis rats aged 3 weeks were randomly divided into 3 groups. Group 1 (stoma group) received a stoma (t = 0), stoma closure 2 weeks later (t = 1), and were killed 2 weeks after stoma closure; group 2 (transection group) had a colon transection and immediate anastomosis (t = 0) and were killed 2 weeks afterward. Group 3 (sham group) had no operation. In all groups, the nerve/muscle fiber ratio (NMR) in the proximal and distal colon was assessed with full thickness biopsy specimens at operation or after killing. The NMR in the stoma, transection, and sham group at t = 1 were used to assess the effect of deprivation of passage of feces and transection itself on the development of the ENS of the colon. Results of the stoma group at t = 1 and t = 2 were compared to assess possible reversibility of ENS changes after stoma closure. RESULTS: There was a significantly higher NMR in the distal colon compared to the proximal colon in both the stoma and transection groups at t = 1 (2.0 +/- 0.38, P < .001 and 2.8 +/- 0.97, P < .001, respectively), whereas there was no significant difference in NMR ratio at t = 1 (1.1 +/- 0.18, P = .34) in group 3. In group 1, the NMR ratio increased further after stoma closure to 3.1 +/- 0.37, P < .001, at t = 2. CONCLUSION: Transection of the bowel rather than deprivation of fecal passage causes nerve fiber hypertrophy in the distal colon of neonatal rats. Restoration of bowel continuity does not result in recovery of these ENS changes.

Effect of IGF-rich colostrum on bowel adaptation in neonatal piglets with short bowel syndrome.

BACKGROUND: Insulin-like growth factor 1 (IGF-1), a polypeptide growth factor with mitogenic effects on intestinal epithelial crypt cells occurs naturally in high concentrations in colostrum. The hypothesis for this study was that colostrum rich in IGF-1 could promote small bowel adaptation in neonatal piglets with short bowel syndrome. METHODS: Twenty-four piglets, aged 7 days, underwent 75% small bowel resection and were fed 525 kJ x kg(-1) x d(-1) (125 kcal) of colostrum-based formula (Rs(+)) or placebo formula (Rs(-)). Immunoglobulin G (IgG) accounted for 35% of the protein and was compensated with casein and whey protein in the control feed. The piglets were weighed daily and killed 28 days after surgery. Bowel samples were taken at surgery and at death. RESULTS: Relative body-weight increase did not differ between the Rs(+) and Rs(-) group (84% +/- 9% vs. 90% +/- 12%, P = 0.83). There was a significant relative increase in crypt depth in the Rs - compared with the Rs + group (201% +/- 15% vs. 147% +/- 17%, P = 0.02) and total protein (mg/cm bowel) (482 +/- 51 vs. 278 +/- 46, P = 0.008). Increase in villus length, DNA/RNA content, and mitotic index did not differ between groups. CONCLUSION: Colostrum supplement rich in IGF-1 has no benefits over protein-enriched feed with respect to growth and bowel adaptation in neonatal piglets with short bowel syndrome.

A successful short-bowel syndrome model in neonatal piglets.

BACKGROUND: With the higher survival rate of premature neonates as a result of improved neonatal intensive care, the incidence of necrotizing enterocolitis, and thus the incidence of short-bowel syndrome, is increasing. An appropriate animal model resembling the (premature) neonate with short-bowel syndrome suitable for clinically relevant neonatal bowel adaptation and intervention studies, is not available at present. The purpose of this study was the development of a short-bowel syndrome model that mimics the clinical state of the affected neonatal patient. METHODS: Sixteen 7-day-old piglets received either a small bowel transection (group A) or a 75% resection (group B). The piglets were fed 125 kcal/kg body weight per day, including additional electrolytes. The animals were weighed daily and were killed 28 days after surgery. Bowel samples were obtained at both time points. RESULTS: Mortality rates in groups A and B were 0% and 8%, respectively. Body weight gain was significantly higher in group A than in group B (156% vs. 93%; P = 0.01). Jejunal villus length was higher in group B than in group A (74% vs. -2%; P = 0.006), and crypt depth was higher in group B in both jejunum (201% vs. 67%; P = 0.001) and ileum, (197% vs. 20%; P = 0.001), than in group A. CONCLUSIONS: In 7-day-old piglets 75% small bowel resection leads to a clinical short-bowel syndrome, demonstrated by reduced weight gain and typical changes in bowel adaptation parameters. The excellent survival of the animals provides a possibility for the study of bowel adaptation in a neonatal model as well as in intervention studies.