[Calcified cerebral metastasis]. / Metástasis cerebral calcificada.

A hyperdense intraparenchymal lesion on a cerebral computed tomography (CT) usually corresponds to an acute hematoma; however, it is sometimes necessary to rule out a metastatic cause. Focal calcifications in the brain are common and are most often due to granulomas (tuberculosis, cysticercosis...), hamartomas, and primary brain tumors. Cerebral metastases are the most common intracranial neoplasm; however, their rate of calcification in classic series is only approximately 1%. We report the case of a completely calcified cerebral metastasis studied by CT and magnetic resonance imaging (MRI) that was interpreted as acute hemorrhage on the first CT examination.

Histochemical study of glycoconjugates in the nasal mucosa of the rat and guinea pig.

A histochemical study was carried out on the glycoconjugates of the nasal mucosa of rat and guinea pig using conventional techniques and peroxidase-labelled lectins. Both the respiratory mucosa and neuroepithelium were studied. Sulphate and sialic acid groups were found in the mucous layer of the neuroepithelia, Bowman's glands and goblet cells. In contrast, the nasal glands did not possess these groups, and only a few showed neutral mucins. Carbohydrate residues were more numerous in the acini of the Jacobson glands. Thus, the nasal glands in the rat and guinea pig are probably of a serous type because of the scarcity of carbohydrate residues.

Lectin histochemistry of the olfactory surface in two teleostean fishes.

A histochemical study on carbohydrate sequences in the epithelial surface of the olfactory organs in 2 teleostean species was carried out by means of lectins conjugated with peroxidase. At the same time, the distribution of the 2 kinds of epithelium are found, and the influence of decalcification with HNO3 in the pattern of reactivity to the lectins used were studied. The 2 components which reacted with the lectins were: 1. the apical surface of the olfactory epithelium, which was rich in L-mannose, N-acetyl-glucosamine, or sialic acid residues, and 2. the goblet cells which presented N-acetyl-glucosamine or sialic acid and N-acetyl-galactosamine. In neither site were found residues of L-fucose. The non-olfactory epithelium, where the goblet cells were located, showed signs of proceeding from a metaplasia of the olfactory epithelium. The decalcification in general terms supposed an intensification of the binding of the lectins to the tissues studied, and also the presence of new affinities which were not found without this treatment. In conclusion, the olfactory epithelium of these 2 teleostean fishes showed a rich layer of carbohydrates on its surface that is probably not only secreted by the goblet cells but also by the supporting cells.

Freezing of the esophagus: histological changes and immunological response.

Experimental freezing of the esophagus was accomplished in canines. The temperature used was from -10 degrees C. to -20 degrees C., for from two to ten minutes. Histological studies revealed cryonecrosis, limited to the cells immediately in contact with the probe surface, edema and cryothrombosis, as the most outstanding and significant histological lesions. Preliminary evaluation of the effects of in situ freezing of the esophagus is suggestive of the development of a cellular response. This response appeared to be directed to antigens present in extracts of esophageal mucosa and muscularis. Repeated in situ freezing of the esophagus resulted in the development of an increased (i.e., anamnestic), immunologic response to mucosa and muscularis antigens. The results of this experiment suggest the use of freezing techniques as an alternative to total esophageal resection for early carcinoma of the esophagus. The 98% cure rate of freezing techniques in the squamous cell carcinoma of the skin encourages us to emphasize the possibility of using this technique with a similar degree of success in early carcinoma of the esophagus.

An experimental study on the significance of muscle tissue interposition on fracture healing.

Ten ulnae of mongrel dogs were osteotomized and a 3 to 5 mm cylindrical segment of bone removed from each shaft. In 10 ulnae of the opposite forelimb, living muscle tissue was placed in the resection site. The control ulnae (Set 1, Set 2) revealed 60 per cent unions, while the experimental ulnae revealed 100 per cent non-unions as determined by radiological and histological examination. Although necrotic muscle will be invaded by primitive bone, healing is certainly delayed or does not occur. A large muscle mass contributes a barrier too large to be successfully incorporated into the healing process of a fracture of the shaft of a long bone. On the basis of this experiment fractures should be opened and obstructing tissue removed whenever conservative measures fail to remove muscle interposition.