Randall C. Dunn

Evaluation of the SprayGel™ adhesion barrier in the rat cecum abrasion and rabbit uterine horn adhesion models

OBJECTIVE To evaluate the efficacy of a new adhesion barrier in the prevention of postoperative adhesion formation. DESIGN A double-blind controlled study of the efficacy of SprayGel in reducing postoperative adhesion formation in two animal models. SETTING Animal care facility of a contract testing laboratory. ANIMAL(S) Sixteen Sprague-Dawley male rats were randomly allocated into two groups in the cecum abrasion model. Twenty New Zealand white female rabbits were randomly allocated into two groups in the uterine horn abrasion model. INTERVENTION(S) In the rat model, the cecum was abraded with gauze and the abdominal wall was abraded with a scalpel. Treated animals received SprayGel coating on injured surfaces; control animals received no treatment. In the rabbit model, uterine horns were abraded with a scalpel. Treated animals received SprayGel coating on injured surfaces; control animals received no treatment. MAIN OUTCOME MEASURE(S) Postoperative adhesion formation. RESULT(S) In the rat model, SprayGel was found to significantly reduce the incidence of adhesions, which formed in 7 of 8 control rats compared with 1 of 8 treated rats. In the rabbit model, SprayGel was found to significantly reduce both the extent and severity of adhesions. CONCLUSION(S) Application of SprayGel in two animal models reduced formation of postoperative adhesions. Further investigation in large animal and clinical settings is warranted.

Efficacy of a resorbable hydrogel barrier, oxidized regenerated cellulose, and hyaluronic acid in the prevention of ovarian adhesions in a rabbit model.

OBJECTIVE To compare the efficacy of a resorbable hydrogel material with oxidized regenerated cellulose and hyaluronic acid in an ovarian adhesion model. DESIGN Controlled, blinded, and randomized study involving female rabbits. SETTING Academic research environment. INTERVENTIONS A water-soluble hydrogen precursor was applied to the ovary as a liquid and converted to a hydrogel by exposure to long wavelength ultraviolet light, a 0.4% solution of hyaluronic acid was applied to the ovary, or an oxidized regenerated cellulose patch was applied to the ovary after wedge resectioning. MAIN OUTCOME MEASURES Extent and severity of adhesion formation. RESULTS Application of the hydrogel reduced adhesion formation by 88%. Neither oxidized regenerated cellulose nor hyaluronic acid reduced adhesion formation. CONCLUSION The photopolymerized, resorbable hydrogel material is highly effective for the reduction of periovarian adhesions in this model.

Reduction of postoperative adhesions by N,O-carboxymethylchitosan: a pilot study

OBJECTIVE To examine the logistics, safety, and efficacy of N,O-carboxymethylchitosan (NOCC) in reducing adhesions in women. DESIGN Multicenter, prospective, randomized, reviewer-blinded clinical trial. SETTING Gynecologic practices. PATIENT(S) Thirty-four patients were enrolled; 17 in each group were available for the safety analysis and 16 for the efficacy analysis. INTERVENTION(S) Adhesion reduction by administration of NOCC vs. Ringers lactate at the conclusion of the initial surgical procedure, as assessed at second-look laparoscopy. The NOCC was applied as 200 mL of a 1% NOCC gel that was tamped in place, followed by 100 mL of 2% NOCC solution. Efficacy was assessed by covariate analysis. MAIN OUTCOME MEASURE(S) Safety and postoperative adhesion formation. RESULT(S) Groups did not differ in age, ethnicity distribution, height, weight, or body mass index. No deaths or serious adverse events were attributable to NOCC, and no adverse events were definitively or probably related to NOCC administration. Adhesions recurred at 61% of sites in controls and 38% of sites in NOCC recipients. De novo grade 1a and 1b adhesions tended to occur more commonly in controls than NOCC recipients. Adhesion extent and severity at second look were also less in NOCC recipients. CONCLUSION(S) Intraperitoneal use of NOCC gel and solution appears to be safe. Despite the small sample, strong trends were identified for reduction of occurrence, extent, and severity of adhesion recurrence and de novo adhesion formation.

Low Blastocyst Formation Rates in Day-2 Fertilized Oocytes

Purpose:To examine the blastocyst formation rates of day-2 fertilized oocytes.Methods:A retrospective study of the outcomes/blastocyst formation of day-2 fertilized oocytes was undertaken.Results:Fertilization rates of day-1 and -2 oocytes by intracytoplasmic sperm injection were similar. The development frequencies to four cells were similar. However, the blastulation rates were significantly lower from the day-2 fertilized eggs. The fertilization rates from day-2 conventional in vitro fertilization reinsemination were lower than the fertilization rates of day-1 oocytes. The blastulation rates from day-2 fertilized eggs were also lower than the rates from day-1 fertilized eggs in the in vitro fertilization group.Conclusions:Fertilization is not a good indicator to predict the viability of fertilized oocytes. Day-2 fertilized oocytes had significantly lower blastocyst formation rates than the rates from day-1 fertilized oocytes.

Growth factor effects on endometrial epithelial cell differentiation and protein synthesis in vitro*†*Supported by The Women’s Fund, Houston, Texas, and by grant HD25189 from the National Institutes of Health, Bethesda, Maryland.†Presented at the 47th Annual Meeting of The American Fertility Society, Orlando, Florida, October 19 to 24, 1991.

OBJECTIVE To develop a baseline for projected studies of a rat endometriosis model. DESIGN We investigated the effects of two macrophage-related growth factors, platelet-derived growth factor (PDGF) and transforming growth factor-beta (TGF-beta), on proliferation, in vitro differentiation, and protein secretion of uterine epithelial cells from immature rats. Uterine epithelial cells grown on matrix covered filters were treated with growth factors (GFs) or estrogen and/or P. Incorporation of [35S]methionine by polarized uterine epithelial cell proteins and secretion of labeled proteins into apical and basal culture medium were examined. SETTING Department of Cell Biology, Baylor College of Medicine, Houston, Texas. MAIN OUTCOME MEASURES Cell associated and secreted proteins were resolved by gel electrophoresis, fluorography, and immunoblotting. Proliferation was quantified by cell counts in parallel cultures by hemocytometer. RESULTS Estrogen and P increase protein synthesis by uterine epithelium. Transforming growth factor-beta depressed protein synthesis and secretion in uterine epithelial cells. Platelet-derived growth factor appears to have no effect on epithelial protein synthesis or secretion and does not modulate the effect of TGF-beta. Estrogen and P increase complement component 3 (C3) production by epithelial cells. CONCLUSION Macrophage-secreted GFs may play a role in the development and maintenance of ectopic endometrial tissue. Both TGF-beta and ovarian steroids may participate in the dynamic regulation of protein synthesis by ectopic uterine epithelium. These molecules may indirectly affect the macrophage-stromal axis through nonspecific modulation of C3 secretion. Platelet-derived growth factor appears to have no direct effect on uterine epithelial cells. The recognized effect of PDGF on ectopic endometrial tissue is most likely mediated via the stromal component.