Early steps in neural development

We studied early neurulation events in vitro by transplanting quail Hensen's node, central prenodal regions (before the nodus as such develops), or upper layer parts of it on the not yet definitively committed upper layer of chicken anti-sickle regions (of unincubated blastoderms), eventually associated with central blastoderm fragments. We could demonstrate by this quail-chicken chimera technique that after the appearance of a pronounced thickening of the chicken upper layer by the early inductive effect of neighboring endophyll, a floor plate forms by insertion of Hensen's node-derived quail cells into the median part of the groove. This favors, at an early stage, the floor plate "allocation" model that postulates a common origin for notochord and median floor plate cells from the vertebrate's secondary major organizer (Hensen's node in this case). A comparison is made with results obtained after transplantation of similar Hensen's nodes in isolated chicken endophyll walls or with previously obtained results after the use of the grafting procedure in the endophyll walls of whole chicken blastoderms.

Multilayer vs. monolayer amniotic membrane transplantation for deep corneal ulcer treatment

The purpose of the study was to evaluate the efficacy of multilayer amniotic transplantation (AMT) for reconstruction of corneal stroma and epithelium. Corneal ulcer (28) was a consequence of a previous infectious or neurotrophic keratitis. In the first group (17) ulcer was covered with monolayer AM, while in the other group (11) there were two or more layers of AM situated in the ulcer and the whole cornea was covered with AM sheet. Monolayer AMT was successful in 64% while the multilayer AMT success rate was 72%. AM gradually dissolved within 3-6 postoperative weeks. AM transplantation facilitates rapid healing of corneal epithelium, reduces inflammation and stimulates epithelial cell regrowth. In eyes with deep corneal ulcer multilayer technique proved to be better then monolayer procedure.

The preparation of lyophylised of fetal membrane for biological dressing

The preparation of lyophylised fetal membrane was performed between November 1982 and May 1984, and the membrane was applied to a variety of wounds. The result of the study was impressive, the biologic dressing property did fairly well, and the utilization of this fetal membrane was convenient in time and place.

[An experimental induction of teratomatous tumor in rats]

Extrauterine implantation of the fetal membrane was performed in Wistar King A strain rats by the technique of fetectomy at the time of the twentieth gestational day. Thirty-five rats received fetectomy alone, and in nineteen rats the fetectomy was combined with 7,12-dimethylbenz (a) anthracene (DMBA) application. The results obtained were as follows: In the fetectomy group, 23(65.7%) tumors 17(73.9%) mature teratomas and 6(26.1%) yolk sac tumors occurred. In the group which also received the application of DMBA, the tumors were found in seven of 19 rats (36.8%). The incidence of yolk sac tumor was 28.6% in this group and the remaining five tumors were mature teratomas. The direct application of the carcinogen did not affect the incidence or histology of the induced tumor. To identify the exact histogenesis of these teratomatous tumors from the fetal membrane, further research is necessary.

Amnion graft for treatment of congenital absence of the vagina

The successful application of an amniotic membrane graft in the treatment of congenital absence of the vagina is described. Follow up with vaginal smears and vaginal biopsies revealed that amnion when used alone with mesenchyme applied to the host gives protection to the underlying granulation tissue and facilitates epithelialization.

In search of an ideal skin substitute

A review of skin substitutes currently in use is presented. These include allografts, xenografts, embryonic membranes, tissue derivatives and synthetic skin substitutes. Clinical results from Langerhans cell depressed cadaver allografts on burned patients and crural ulcers are presented.

Management of the pelvic floor after pelvic exenteration

At the Mayo Clinic, 198 exenterative operations were performed from 1950 through 1971. Although the 5-year survival rate of all patients was 33%, bowel obstruction occurred in 11.6% of patients and intestinal fistula formation in 12.6%. The majority of patients with these complications had had previous pelvic irradiation. The difficulty in dealing with the large raw area in the pelvis is discussed with a review of the various methods that have been tried to date to reperitonealize the pelvis and thereby, it is hoped, prevent adhesions or fistula formation.

[Repair of prenatally ruptured omphalocele and the paraumbilical abdominal wall defect with the infant's own fetal membranes (author's transl)]

Since 1971, 35 children with prenatally ruptured omphalocele and paraumbilical abdominal wall defects were operated on in the surgical clinic of the Cologne Children's Hospital. 45.7% of them survived compared with 29.2% in earlier years. This improved chance of survival is attributed the use of the child's own fetal membranes.

[Use of amniotic membranes as biological dressings. Preliminary report]

The authors compared the results obtained with the use of amniotic membranes as biological dressings in the treatment of 15 patients with skin loose of different etiology and that obtained with the conventional therapy. The associated benefits obtained with this treatment were lessen of the pain, low incidence of infections, early cicatrization of the wounds and shortening of the hospital time. The primary observations permit a wide investigation about the therapeutic usefulness of this kind of biological dressings.