The healing of visceral and parietal peritoneum has been investigated using conventional light microscopy, Hautchen preparations, and by using 1 μ sections of epoxy‐resin‐embedded material to follow the activity of peritoneal macrophages labelled with polystyrene spheres (0.79 μ in diameter). Healing has been found to occur rapidly and for the most part without adhesion formation. Parietal peritoneum and caecum are covered by a new mesothelial membrane in 8 days, while the liver is covered in 7 days. It has not been possible to support the theory that peritoneal macrophages are transformed into mesothelial cells via fibroblasts. The results obtained in the present investigation suggest that the new mesothelial layer is derived directly from the subperitoneal fibroblast.

A study was performed to test the hypothesis that renal allograft recipients are at high risk of developing anal human papillomavirus (HPV) infection and anal intraepithelial neoplasia (AIN). A total of 133 renal allograft recipients and 145 control patients underwent anoscopy and biopsy. A polymerase chain reaction was used to detect HPV16 DNA in biopsy samples. A histological diagnosis of anal HPV infection or AIN was made in 32 allograft recipients (HPV infection, five; AIN I, 20; AIN II, three; AIN III, three; AIN III and anal cancer, one). One subject with AIN was detected in the control group. HPV16 DNA was detected in 47 and 12.4 per cent of anal biopsies in the allograft and control groups respectively. Renal allograft recipients are at high risk of developing anal HPV infection and neoplasia (P < 0.05). Further studies are required to determine whether screening anal examination is required in organ allograft recipients.

1, Observations have been made by light and electron microscopy of the development of peritoneal adhesions in lhe rat following abdominal surgery.2. Essentially the changes which occurred were those which are seen in healing by fibrosis, except that in many areas of adhesions numerous eosinophils were observed by electron microscopy. In areas where eosinophils were numerous little profijeration of fibroblasts was seen. Conversely in sites where fibroplasia and collagen formation were well advanced no eosinophils were seen.3. The role of the eosinophil in the development of adhesions is discussed and it is suggested that the presence of eosinophiis with their associated antihistamine activity may hold in check the proliferation of' fibroblasts while a new mesothelium is formed and thus prevent adhesion formation.

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