A multicentre, double-blind, randomized study to compare the safety and efficacy of once-daily ORG 10172 and twice-daily low-dose heparin in preventing deep-vein thrombosis in patients with acute ischaemic stroke.

A multicentre, double-blind, randomized study was performed in 179 patients with acute ischaemic stroke resulting in limb paresis. The purpose was to compare the safety and efficacy of Org 10172 (1250 anti-Xa Units s.c. once daily) and heparin sodium (5000 IU s.c. twice daily) in preventing deep-vein thrombosis (DVT). Prophylaxis started within 72 hours of the onset of stroke and continued for at least 9 days. To detect DVT, patients underwent a daily 125I-fibrinogen leg scanning which, if found positive, was followed by venography. A first computed tomography scan of the brain was performed at screening to rule out cerebral haemorrhage and a second at cessation of treatment to detect any haemorrhagic transformations. At the 2-3-months' follow-up period the patients were examined for signs and symptoms of DVT or pulmonary embolism. On an intention-to-treat analysis, DVT occurred in 14.6% of patients receiving Org 10172 and in 19.8% of those receiving heparin during the treatment period (p = 0.392, NS). Pulmonary embolism was diagnosed in one patient in each group. Major conversion to a symptomatic haemorrhagic brain infarct was found in one patient in each group. Death occurred in 13.5% of patients treated with Org 10172 and in 6.7% of patients treated with heparin (p = 0.135, NS). Deaths were mainly related to pulmonary infection and cerebral oedema, thus considered to be due directly to the clinical status of the patients. 1250 anti-Xa Units of Org 10172 once daily is both safe and as effective as 5000 IU of heparin sodium twice daily given for DVT prophylaxis in patients with acute ischaemic stroke of recent onset.

Stroke epidemiology in Novi Sad.

Since the organization of CINDI (Countrywide Integrated Non-Communicable Disease Intervention Programme) and MONICA (Monitoring of Trends and Determinants of Cardiovascular Disease) in 1983 over the whole territory of Novi Sad community it has been found that the incidence of stroke has decreased from 2.68 to 2.36%, the mortality from 67.1 to 42.2% and the number of registered stroke survivors (morbidity prevalence) has increased almost three times. The subjects, material and methods as well as the results obtained so far are presented in this paper.

S-100 protein in soft-tissue tumors derived from Schwann cells and melanocytes.

In soft tissues outside the central nervous system, S-100 protein is found normally only in Schwann cells. Using the peroxidase-antiperoxidase immunohistochemical method S-100 was also found in tumors derived from Schwann cells and melanocytes, including neurofibromas, neurilemomas, granular cell myoblastomas, cutaneous nevi, and malignant melanomas. S-100 was not detected in malignant Schwannomas, neuroblastomas, oat cell carcinomas, medullary carcinomas of the thyroid, paragangliomas, or meningiomas. S-100 was also absent from neoplasms of soft tissues not usually considered to arise from cells of neural crest origin. S-100 appears to be a useful marker for identifying neoplasms derived from Schwann cells and melanocytes.

Ultrastructural changes accompanying the growth of isolated oligodendrocytes.

The changes in the ultrastructure of oligodendrocytes with time in culture were examined by transmission electron microscopy. Oligodendrocytes were isolated from ovine white matter and maintained in Dulbecco's modified Eagle's medium supplemented with 20% horse serum. One day after being placed in plastic culture dishes, most cells aggregate into clusters that do not attach to the surface for several days. Cells within these clusters form junctional complexes resembling gap junctions, their nuclear chromatin becomes uniformly dispersed, they are rich in polyribosomes, and their cytoplasm is less osmiophilic than oligodendrocytes in ovine white matter or cells fixed immediately after isolation. After several days in culture, the cells become attached to the plastic surface, chromatin once again becomes clumped beneath the nuclear membrane, rough endoplasmic reticulum accumulates within the cytoplasm and the cells extend long processes containing cytoplasmic organelles. From these observations, it appears that oligodendrocytes undergo a transient dedifferentiation during their recovery from the trauma of isolation, not unlike the central chromatolysis seen in neurons following axonal injury. After acclimatization to tissue culture conditions, isolated oligodendrocytes show many of the morphologic features seen in vivo and therefore offer a good model to study myelination.