R Ghassemifar | PubMed Health

PubMed1992

A double-embedding technique for thin tissue membranes.

A new double-embedding technique for thin tissue membranes is presented. This technique is useful for thin membranes such as mesenteric membranes from rodents, which usually measure only 10 microns in thickness. Several membranes are fixed and mounted on four needles located at the bottom of a plastic box. The box is filled with agarose at 50 C and then allowed to solidify. The agarose block is then removed, dehydrated in alcohol, cleared with HistoPetrol (isoparaffin hydrocarbons), permeated with paraffin and sectioned. The morphology is comparable to that obtained with methacrylate plastic embedding but is less time-consuming, less hazardous since no plastic hardener and activator are used and makes immunohistochemical studies easier.

Animals↗

PubMed1991

Experimental mast cell activation improves connective tissue repair in the perforated rat mesentery.

The participation of mast cells in connective tissue repair was studied using the perforated-rat-mesentery model. Perforation of mesenteric membranes was performed during laparotomy of anesthetized Sprague-Dawley rats. Laparotomy significantly reduced the histamine content of the mesenteric membranes on day 1 postoperatively and perforation as such reduced the histamine content even more on days 1-10. Mast cell activation induced by a single intraperitoneal injection of Compound 48/80 two days prior to operation, significantly improved healing on days 5-7 postoperatively. Daily injections of Compound 48/80 for 5 days prior to operation showed significantly better healing compared to such injections for five days postoperatively. Administration of lupitidine, a long acting histamine H2-receptor antagonist, two times daily starting on the day of 48/80 injection to day 4 after operation did not apparently affect healing. The results indicate that mast cells may be activated during normal wound healing and that a preoperative, pharmacological activation improves healing. Furthermore, histamine does not seem to be of major importance for the beneficial effect of such mast cell activation on connective tissue repair.

Animals↗