The immunohistology of CD40 in human oral epithelium in health and disease

BACKGROUND: CD40 has a role in the regulation of immune responses, cell proliferation and migration, and apoptosis. Little is known of its distribution in oral mucosal pathology. METHODS: Oral keratinocyte lines were tested for CD40 protein by Western blotting. Immunohistochemistry was used to stain paraffin sections of oral mucosa in health and in inflammatory, reactive, dysplastic and malignant disease. RESULTS: Western blotting confirmed the presence of CD40 in oral keratinocytes. CD40 was generally expressed by keratinocytes in the basal layer, with variable parabasal expression. Langerhans cells also stained positively. Expression was lost in nine of 33 (27%) epithelial dysplasias, seven of which were severe. Eighty-one percent of well, 69% of moderately and 50% of poorly differentiated oral squamous cell carcinomas (OSCC) expressed CD40. Overall, 45 of 65 (69%) OSCC were positive. The pattern of expression was unrelated to tumour differentiation. CONCLUSION: CD40 expression by basal and parabasal oral keratinocytes is physiological. Expression is lost in approximately one-third of oral epithelial dysplasias and OSCC. The significance of such loss remains unknown, but may be related to immunological or other abnormalities of keratinocyte homeostasis.     

Deep venous thrombosis and pulmonary embolism. The importance of heightened awareness.

Left untreated, deep venous thrombosis and pulmonary embolism have a high rate of mortality and long-term morbidity. Physicians therefore must maintain a high index of suspicion for these conditions. Accurate diagnosis is facilitated by knowing the most common sites of thrombus formation, the likelihood of propagation, which patients are at greatest risk, signs and symptoms, and which tests to order. Prompt administration of anticoagulants and, in some cases, thrombolytic agents can minimize the consequences of these diseases. Interruption of the inferior vena cava, thrombectomy, and thromboembolectomy are other treatment options.     

Pancreatic islet transplantation future prospects

There is good evidence that the long-term complications of diabetes are caused by poor control of blood sugar, even in patients where intensive glucose monitoring is used to control insulin therapy. Pancreatic transplantation offers the potential for normalisation of glucose metabolism, but at the cost of major surgery and immunosuppression. The possibility of separating the insulin-secreting tissue from the exocrine gland has many attractions. Isolated pancreatic islets are small enough to allow transplantation as free grafts by an injection technique. Furthermore, it may be possible to modify the graft in such a way as to prevent rejection with minimal or no immunosuppression. For pancreatic islet transplantation to become useful in clinical practice it will be necessary to develop efficient techniques for harvesting viable islet tissue in adequate quantities, identify a suitable site for transplantation and prevent rejection. Over the past 20 years experimental models of islet transplantation have proven the potential of this approach, but until recently it has not been possible to translate these experiments into clinical practice. Recently, there have been significant advances in the techniques available for separation of islets from the pancreas of large mammals and man, and recent clinical trials of islet transplantation have shown evidence of short-term function. However, significant problems remain, particularly those of rejection and the maintenance of long-term function, before introduction of clinical islet transplantation as standard therapy for diabetes can be expected.     

Corticosteroid therapy in Riedel's thyroiditis.

We report a case of Riedel''s thyroiditis presenting with a systemic illness, life-threatening stridor and a stony hard goitre. Diagnosis was confirmed by open thyroid biopsy. Treatment with corticosteroid resulted in a dramatic improvement. A possible autoimmune mechanism in the pathogenesis of Riedel''s thyroiditis is discussed.