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Three consecutive randomized open studies have been carried out to determine the optimal dosage of low molecular weight heparin (LMWH) in the prevention of postoperative thrombosis in general surgery (892 patients). All patients undergoing abdominal, gynaecological, thoracic or urological surgery were over 40 years old and presented at least one of the following risk factors for thrombosis: previous thromboembolism, obesity, varicose veins, malignancy (30 per cent), pre-operative hospitalization over 5 days, oestrogen therapy, chronic cardiac disease or bronchitis. Isotopic venous thrombosis and bleeding complications were assessed after subcutaneous administration of a LMWH fragment (LMWH, Enoxaparine) or unfractionated heparin (UH). The three studies compared 3 × 5000 units UH daily with 1 × 60 mg, 1 × 40 mg, 1 × 20 mg LMWH daily. Thromboembolic events rates were not significantly different from group to group (UH: 3.8 per cent, 2.7 per cent, 7.6 per cent respectively compared with LMWH: 2.9 per cent, 2.8 per cent, 3.8 per cent). Bleeding episodes including wound haematoma formation, perioperative blood losses and systemic haemorrhage were not significantly different in patients receiving LMWH or UH. Significant decreases in haematocrit and haemoglobin were only observed in patients receiving 60 mg Enoxaparine (as compared to UH). An analysis using the ‘intention to treat’ approach gave results consistent with those of an analysis of good compliers. An overview of isotopic thromboses in the three studies gave no evidence of differences amongst the effects of the three doses of LMWH (P = 0.20), and pooling the results of the three studies using the Mantel-Haenszel procedure gave no evidence of a global difference between Enoxaparine and UH (P = 0.54). These results suggest that an optimal dosage of 20 mg/day of Enoxaparine is safe and effective in the prevention of postoperative thrombosis in this population.

Calcitonin- and serotonin-storing cells have been immunocharacterized in prostate gland, urethra, urinary bladder and anal canal. In addition, a few hCG and somatostatin immunoreactive cells have been detected in prostate gland. All these cells were dispersed throughout the epithelial lining. In the anal canal, calcitonin cells were exclusively confined to the anal ducts and anal transitional zone epithelium. Calcitonin and serotonin cells were seen in some examples of prostatic adenocarcinoma. Combined techniques most often showed coexistence of calcitonin and serotonin immunoreactivities in the same endocrine cell. hCG immunoreactive cells corresponded to a subpopulation of serotonin-, calcitonin-storing cells. Calcitonin and serotonin cells were present in most organs which originated from the cloaca. In this territory, this distinctive endocrine pattern could be regarded as an excellent marker of cloacal derived tissues. These tissues constitute an additional site for extrathyroid C-cells. It is likely that calcitonin cells are a component of some prostatic adenocarcinomas.

Endocrine cells are a normal constituent of the prostate gland, prostatic urethra and urinary bladder mucosa. Positive results using immunohistochemical technics were obtained only with antiserotonin antibodies. In normal tissues, there was a close similarity between the distribution of argyrophilic cells (Grimelius) and serotonin-storing cells. Some striking features were the patchy distribution of endocrine cells, the presence of slender cytoplasmic processes occasionally reaching the luminal surface and the paucity of specialized cells in bladder mucosa. It is unlikely that endocrine cells participate in conventional neoplasms of prostate and bladder. Exceptions are lobular hyperplasia, certain adenocarcinomas of prostate and inverted papilloma of bladder.

A systematic detection of endocrine cells in the renal pelvis and ureter was carried out, using Grimelius stain and immunohistochemical techniques. Ninety specimens of pelvic and ureteral mucosae were investigated. Throughout the pelvic urothelium, endocrine cells were very uncommon, patchily distributed, and serotonin-storing. They have been disclosed in only two cases among normal-appearing transitional epithelium. Whether cells so scanty are normal and permanent inhabitants of this territory is debatable. The material examined did not provide opportunity to demonstrate endocrine cells throughout the normal ureter. Surprisingly, one case of supernumerary ureter with an ectopic distal orifice into the urethra harbored abundant serotonin cells. This remarkable endocrine profile, which departed appreciably from that of normal ureter, showed a close similarity with that of the urethra. This raises the question whether such endocrine differentiation might reflect, for this ectopic ureteric bud, urogenital sinus origin rather than wolffian origin.