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Biomedical subjects

C A Akle

Publications and source records attributed to C A Akle.

12 recordsLinked to original sources

Endoprostheses for colonic strictures.

BACKGROUND: Patients who present with large bowel obstruction often undergo emergency surgical intervention with its attendant risk of morbidity and death. A colostomy may be inevitable and this detracts from the patient's quality of life, especially when palliation is the only option. METHODS: This review examines the possibility of a more conservative approach using metallic stents to relieve colonic obstruction, either as the first stage of a curative surgical procedure or for palliation without surgery. The various stents available are examined. RESULTS: Case reports show that relief of obstruction can be achieved in over 80 per cent of patients, allowing subsequent elective surgery or achieving palliation for several months. Complications are rare but include colonic perforation, particularly when predilatation of the stricture has to be performed. Such complications are generally recognized early and patients can proceed to surgery and colostomy, as would previously have been conventional treatment; on occasion a small leak may be treated conservatively with success. The advent of newer endoprostheses which do not require active dilatation may improve the rate of successful deployment and lessen the risk of perforation. CONCLUSION: The development of new endoprostheses has allowed their adaptation for use in the colon and, perhaps, the distal small bowel. The technology is evolving rapidly and warrants serious consideration in selected patients with large bowel obstruction before embarking on surgery. There is an urgent need for a controlled trial to establish whether such intervention for malignant strictures, potentially curable by surgery, leads to an increased risk of metastatic disease.

Adult

Immunogenicity of human amniotic epithelial cells after transplantation into volunteers.

Human amniotic epithelial cells do not express on their surfaces HLA-A, B, C, and DR antigens, or beta 2-microglobulin. In vitro these cells synthesise the enzymes lacking in patients with selected enzymatic deficiencies: the survival of a transplanted monolayer of human amniotic epithelial cells was therefore investigated in seven volunteers. None of the volunteers showed clinical signs of acute rejection, and amniotic epithelial cells were demonstrated by biopsy up to 7 weeks after implantation. HLA antibodies were not detected in samples of serum from four volunteers thoroughly investigated, and there was no in-vitro lymphocyte reaction to the amniotic cells in two of them. The results suggest that acute immune rejection does not occur after the transplantation of human amniotic epithelial cells.

Adult

Permeability of the amniotic membrane and its potential application for transplantation purposes.

Uncertainty still exists as to the immunologic and physiologic properties of human amnion. It is clear, however, that these cells have a unique function and ultrastructure and may lack histocompatibility antigens. This raises the possibility of using the amnion for the replacement of a defective tissue or to protect an incompatible graft. In addition, the amniotic epithelial cells could be used to treat patients with inborn errors of metabolism. With this in mind, we have investigated the in vitro transfer of a number of compounds across the human amniotic membrane and furthermore have assessed the suitability of the amnion for transplantation purposes in an experimental model.

Amnion