Proprietary non-animal stabilized hyaluronic acid/dextranomer gel (NASHA/Dx) for endoscopic treatment of grade IV vesicoureteral reflux: Long-term observational study.

BACKGROUND: Since 1993, children aged >1 year with persistent grade III-V vesicoureteral reflux (VUR) and febrile urinary tract infections (UTIs) attending Uppsala University Hospital have undergone endoscopic injection with proprietary non-animal stabilized hyaluronic acid/dextranomer gel (NASHA/Dx; Deflux®). OBJECTIVE: Investigate long-term incidence of UTI, bladder dysfunction, ureteral reimplantation and overall clinical findings following endoscopic injection of NASHA/Dx. STUDY DESIGN: Children with grade IV VUR diagnosed by voiding cystourethrogram (VCUG) and dilating VUR persisting for >1 year were included in this study. 15-25 years after endoscopic treatment, patients' hospital charts were studied. Information on bladder function and UTIs was obtained via questionnaire, 8-18 years after endoscopic treatment. RESULTS: 185 patients (69 boys, 116 girls) were included in the study; 237 grade IV VUR ureters were treated. All study patients were diagnosed with VUR after a febrile UTI (i.e. pyelonephritis). According to the last voiding cystourethrogram, 69% of ureters showed a positive response (VUR grade 0-I), 7% had VUR grade II and 23% had VUR grade ≥ III. 46 patients (25%) required ureteral reimplantation during follow-up. Among patients treated during the second 5-year period compared with the first (1998-2003 versus 1993-1998), there was a significant decrease in the rate of ureteral reimplantation (31% vs 16%; p = 0.0365). This difference may be attributable to developments over time in the injection technique. UTIs occurred in 30 patients (21% of the evaluable population): 28 females and 2 males. Febrile UTIs were reported in 14 patients (10%), all females. Forty-nine patients (34%) had bladder problems (e.g. underactivity, overactivity, incontinence). Five patients underwent ureteral reimplantation 'late', 6-10 years after the last endoscopic injection. In one male patient, calcification around the NASHA/Dx implantation site was observed during routine examination 2 years after endoscopic treatment; no intervention was required. No safety issues were observed in the remaining 97% of the study population. CONCLUSIONS: This study represents the longest published follow-up of Grade IV VUR patients undergoing endoscopic treatment. Three-quarters of patients did not need ureteral reimplantation. Optimal injection technique and higher injection volume were associated with a reduced ureteral reimplantation rate. Treatment with NASHA/Dx was durable and well tolerated: long-term risks of UTI, bladder dysfunction and recurrent VUR were low.

Genes regulating tight junctions and cell adhesion are altered in early experimental necrotizing enterocolitis.

BACKGROUND/PURPOSE: Necrotizing enterocolitis (NEC) represents one of the gravest complications in preterm infants and carries significant morbidity and mortality. Increased intestinal permeability may play an important role in the pathogenesis of NEC. In this study we investigated the genes regulating structural proteins such as tight junctions (TJ) and cell adhesion in a neonatal rat model of early NEC. METHODS: The studies were performed on Sprague-Dawley rat pups. Experimental NEC was induced using hypoxia/re-oxygenation treatment on day 1 after birth. Intestinal specimens from the ileum were obtained, mRNA was purified, and the transcriptome was analyzed using microarray. RESULTS: We found several TJ genes such as claudins 1, 8, 14, 15, and gap junction protein to be affected. Alterations in genes involved in the inflammatory response was confirmed, along with several genes regulating proteins used as biomarkers for NEC. CONCLUSION: This study indicates that tight junctions and cell adhesion may play a critical role in the pathogenesis of early experimental NEC. Better understanding of the pathogenesis of NEC may lead to novel strategies for the prevention and treatment of NEC.

Intraluminal intestinal microdialysis detects markers of hypoxia and cell damage in experimental necrotizing enterocolitis.

BACKGROUND/PURPOSE: Necrotizing enterocolitis (NEC) represents one of the gravest complications in premature infants and carries significant morbidity and mortality. There is a great need for improved diagnostic methods to reduce the severity and incidence of NEC. The aim of the study was to investigate if intraluminal microdialysis can detect intestinal ischemia in newborn rats with induced experimental NEC. METHODS: The studies were performed on 1-day-old Sprague-Dawley rat pups. Experimental NEC was induced using hypoxia/reoxygenation treatment. Microdialysis catheters were rectally inserted and placed in the rectosigmoid part of the colon. Microdialysate levels of glucose, lactate, pyruvate, and glycerol were measured. Intestinal specimens were collected at the end of the experiments for microscopic evaluation. RESULTS: Intraluminal microdialysis revealed signs of intestinal hypoxia and cellular damage, with a marked increase of lactate and glycerol. Microscopic evaluation confirmed intestinal damage in the NEC group. CONCLUSION: Intraluminal microdialysis can detect intestinal hypoxic stress and mucosal cell membrane decay in a rat model of NEC. Intestinal intraluminal microdialysis is easily accessible through the rectum and may be a useful noninvasive complement to other methods in the assessment of NEC.

Intestinal ischemia measured by intraluminal microdialysis.

OBJECTIVE: To evaluate the possibility of detecting intestinal ischemia by intraluminal microdialysis and comparing the ileum and colon. METHODS: The studies were performed on male Sprague-Dawley rats. In the first part of the study, microdialysis catheters were placed in the sigmoid part of the colon and in the subcutaneous adipose tissue. In the second part of the study, microdialysis catheters were placed in the lumen of the ileum and the colon. The infrarenal aorta was clamped proximal to the cranial mesenteric artery. Microdialysate levels of glucose, lactate, pyruvate and glycerol were measured. Intestinal specimens were removed at the end of the ischemic period for microscopic evaluation. RESULTS: Intraluminal microdialysis could detect early signs of ischemic injury in the ileum, as well as in the colon, with a marked increase of lactate, lactate/pyruvate ratio and glycerol. The increased levels of intraluminal glycerol showed a positive correlation to prolonged ischemia and to higher degrees of intestinal damage. CONCLUSION: Intraluminal measurement of glycerol is a good marker for intestinal ischemia. Intraluminal microdialysis in the colon is easily accessible through the rectum, and may prove to be a valuable clinical tool for diagnosing intestinal ischemia.

T-cell inhibition does not aggravate bacterial translocation from rat small bowel.

BACKGROUND: T-cell mediated immunity has been proposed to have an important function in the defence against translocating microbes from the gastrointestinal tract. After small bowel transplantation massive T-cell immunosuppression is necessary to avoid rejection. As a consequence, infections with intestinal bacteria are the main contributors to mortality in this setting. This could further imply that T cells are important in limiting bacterial translocation. In a model for bacterial translocation from small bowel in the rat we examined the outcome of T-cell inactivation. METHODS: The studies were performed in a model of bacterial translocation from a Thiry-Vella loop of small bowel in the rat. The animals were treated with an anti-alpha/beta T-cell receptor monoclonal antibody (R73). Inhibition of T-cell activation was also made using the immunosuppressive drug cyclosporin A. All animals were sacrificed on day 3 postoperatively and translocation to the mesenteric lymph nodes, liver, spleen, lung and blood was evaluated. RESULTS: Treatment with R73 resulted in an almost complete labelling of T cells but did not result in any increased bacterial translocation compared to animals treated with saline. Neither did immunosuppression with cyclosporin A. CONCLUSIONS: In the model of bacterial translocation from a defunctionalised loop of small bowel the inhibition of T cells does not increase bacterial translocation to mesenteric lymph nodes or promote the systemic spread of the translocating bacteria. This indicates that T cells do not have any important protective function against translocating microbes from defunctionalised small bowel.

The effect of mesenteric lymphadenectomy and Kupffer cell depletion on bacterial translocation.

BACKGROUND: Infectious complications are associated with high morbidity in patients with short bowel syndrome and after small bowel transplantation. Bacterial translocation from the intestine is probably an essential factor in the genesis of these infections. In a model for bacterial translocation in the rat we examined the consequence of mesenteric lymphadenectomy and the depletion of Kupffer cells. MATERIALS AND METHODS: The effect of mesenteric lymphadenectomy was studied in two different models; in rats where a Thiry-Vella loop had been created from small bowel and in rats that had received a syngeneic small bowel transplant. To study the role of the Kupffer cells, rats with Thiry-Vella loops were treated intravenously with the Kupffer cell inhibitor gadolinium chloride. All animals were sacrificed on Day 3 postoperatively and the bacterial translocation to the mesenteric lymph nodes, liver, spleen, lung, and blood was evaluated. RESULTS: Removal of the mesenteric lymph nodes did not result in any increased bacterial translocation in animals with a Thiry-Vella loop. However, the inactivation of Kupffer cells with gadolinium chloride produced a more severe translocation to the liver, spleen, and lungs. After small bowel transplantation the bacterial translocation to the spleen was increased in animals without mesenteric lymph nodes. CONCLUSIONS: In the model of bacterial translocation from a defunctionalized loop of small bowel the inhibition of Kupffer cells will promote the systemic spread of the translocating bacteria. This indicates an important protective function of the Kupffer cells against translocating microbes.