Carcinoma of the anus in Crohn's disease.

The incidence of gastrointestinal cancer in patients with Crohn's disease may be slightly increased. We report 2 cases of squamous cell carcinoma of the anus occurring in patients with distal Crohn's disease.

Carrageenan: a review of its effects on the immune system.

Carrageenans (kappa, lambda and iota) are sulphated polysaccharides isolated from marine algae that can markedly suppress immune responses both in vivo and in vitro. Impairment of complement activity and humoral responses to T-dependent antigens, depression of cell-mediated immunity, prolongation of graft survival and potentiation of tumour growth by carrageenans have been reported. The mechanism responsible for carrageenan-induced immune suppression is believed to be its selective cytopathic effect on macrophages. This property of carrageenan has led to its adoption as a tool for analysing the role of these cells in the induction and expression of immune reactivity. Systemic administration of carrageenan may, however, induce disseminated intravascular coagulation and inflict damage on both the liver and kidney. This is an important consideration in the interpretation of the effects of carrageenan in vivo and precludes its use as a clinical immune suppressant.

Sausage digit due to radish bacillus.

We wish to draw attention to a very characteristic but little known syndrome. An elderly woman presented with a 'sausage finger', rheumatological jargon used to describe diffuse swelling of the digit. This proved to be a proliferative tenosynovitis caused by an atypical mycobacterium, Mycobacterium terrae, or the radish bacillus.

Histological and ultrastructural changes following carrageenan injection in the mouse.

Mice were injected intravenously with either uncharacterised potassium carrageenan or purified iota carrageenan and tissue was examined by light and electron microscopy 1 hr and 24 hr later. The survival of animals injected with these carrageenans was monitored over a 6-month period. Histological examination of liver and kidney was carried out on animals which died during this time and in the surviving mice at 28 weeks. Histological and ultrastructural evidence of disseminated intravascular coagulation was observed within 24 hr of carrageenan injection. The changes were more severe in animals given potassium carrageenan. Electro-microscopic examination of liver revealed carrageenan within membrane-bound vacuoles in Küpffer cells. These cells were largely unaffected by phagocytosis of iota carrageenan but uptake of potassium carrageenan resulted in marked ultrastructural changes and occasional damage to adjacent hepatocytes. Mice given potassium carrageenan had the poorer long-term survival and many animals in this group showed chronic renal damage with features which suggested obstructive nephropathy. A smaller proportion of mice injected with iota carrageenan displayed similar changes. There was no evidence of long-term hepatotoxicity in either group although both types of carrageenan persisted within liver macrophages for at least 6 months after injection.

Serum IgG, IgM and slow alpha-globulin levels in carrageenan-treated rats.

Serum levels of IgM, IgG, slow alpha 1- and slow alpha 2-globulins were measured either by quantitative radial immunodiffusion (IgG) or immunoelectrophoresis (IgM and slow alpha-globulins) during the 3-week period after i.p. injection of 50 mg potassium carrageenan. There was a significant elevation in levels of IgM and slow alpha 1-globulin, maximal on Day 4 and returning to normal by Day 14. Slow alpha 2-globulin was detectable within 24 h, reached a peak at Day 2, and was no longer measurable in most rats by Day 14. Levels of IgG however, were unaffected by carrageenan injection.

Preservation of carrageenan-induced immune suppression with alleviation of toxicity in aprotinin-treated mice.

Although the immunosuppressive effect of carrageenan was unimpaired in aprotinin-treated mice, the extent of intravascular coagulation induced by this macrophage toxic agent was substantially reduced. Use of antiproteases such as aprotinin may prove beneficial in management of this adverse side effect of certain immunotherapeutic agents.

Effect of carrageenan on activity of the mononuclear phagocyte system in the mouse.

Injection of 5 mg carrageenan caused hepatosplenomegaly and thymic involution and resulted in temporary blockade of the mononuclear phagocyte system (MPS). Impaired MPS activity was shown by decreased hepatic phagocytosis of i.v. injected colloidal carbon and 51Cr-labelled sheep red blood cells (SRBC). Depression of Kupffer cell activity was dependent on carrageenan dose, route of administration and interval between carrageenan and particle injection. Reduction in hepatic uptake of SRBC was accompanied by increased localization of these cells within the spleen.

Alleviation of carrageenan-induced hepatotoxicity and acronecrosis by aprotinin.

Carrageenan was found to be hepatotoxic in mice. Raised serum transaminase activity after i.p. injection of carrageenan was correlated with histopathological changes in the liver. These included necrosis of individual hepatocytes and focal areas of necrosis, with associated fibrin thrombi, 12 h after carrageenan injection. Increased mitotic activity was observed at 72 h and extramedullary haemopoiesis was noted at Day 5. Acronecrosis, a further manifestation of intravascular coagulation, was evident within 24 h of carrageenan injection, becoming clearly demarcated by Day 5. Treatment with the anti-protease aprotinin alleviated both the hepatotoxicity and the incidence and extent of acronecrosis induced by carrageenan. The possible mechanism underlying the in vivo toxicity of carrageenan and its alleviation by aprotinin is discussed in the light of these and other findings.

Evaluation of a teaching hospital necropsy service.

The information returned to the hospital clinician after a necropsy was investigated in a series of 1000 patients. It was found that specific clinical queries were answered in 83% of cases, that the necropsy corrected the major clinical diagnosis in 36% of cases, and that 29% of cases were used for undergraduate or postgraduate teaching. The results demonstrate the continuing value of the necropsy as an investigative and educative procedure.