Encoding Conceptual Graphs by Labeling RAAM

The meaning of medical texts... In this paper we discuss the possibility to memorize and retrieve natural language sentences and especially medical language sentences given in this kind of formalism with the use of the LRAAM model [Spe93b, Spe93a]. In Section 2 we explain the idea underlying conceptual graphs. In Section 3 we briefly expose the access by content capabilities of the LRAAM and suggest a generalization of the access by content procedures introducing the concept of Generalized Hopfield Network. A discussion on the impact of this generalization on knowledge extraction from a database of conceptual graphs is given in the conclusion

Non-toxic potentiation of cancer chemotherapy by combined C and K3 vitamin pre-treatment.

The influence on the survival of ascitic liver tumor (TLT)-bearing mice of combined vitamins C and K3 administered before or after a single i.p. dose of 6 different cytotoxic drugs, all commonly used in human cancer therapy, was investigated. Combined i.p. administration of these vitamins produced a distinct chemotherapy-potentiating effect for all drugs examined, especially when injected before chemotherapy. This potentiating treatment did not increase the general and organ toxicity that accompanies cancer chemotherapy. The possible generation of peroxides followed by membrane lipid alteration, DNase activation and DNA destruction by combined vitamin C and K3 in catalase-deficient cancer cells might be involved in the mechanisms of this selective potentiation

Influence of the nature and the dose of the initiator on the development of premalignant and malignant lesions in rat hepatocarcinogenesis.

Using a triphasic protocol recently described to induce malignant tumors in rat liver, the question has been asked whether both the nature and the dose of the initiator influence the carcinogenic process. Two nitrosamines (diethylnitrosamine DEN and N-nitrosomorpholine NNM) have been used to initiate that process. With regard to the premalignant stages appearing in the liver up to 19 weeks after initiation, there is a dose-dependent relationship between the dose of initiator and both the percentage of the parenchyma occupied by and the number of GGT+ lesions. DEN is always more potent than equivalent doses of NNM. With regard to malignant tumors appearing within the period of observation (up to 44 weeks), the two highest doses (100 and 200 mg/kg) of DEN appear to be the only carcinogenic treatments. Cancer incidence (percentage of rats bearing histologically characterized malignant tumor) is the same after both treatments, but the tumor yield (number of tumors per rat bearing macroscopic tumors) is higher (+/- 2X) after 200 mg/kg than after 100 mg/kg

Morphological alterations and DNase deficiency in phenobarbital promotion of N-nitrosomorpholine initiated rat hepatocarcinogenesis.

Tumorigenic effect in rat liver was increased when phenobarbital was given chronically after N-nitrosomorpholine. In these rats the liver parenchyma surrounding pre- and neo-plastic lesions demonstrated distinct, mainly centrilobular zones of hypertrophic hepatocytes with abundant eosinophilic, filamentous cytoplasm, increase in nucleic acids and decrease in DNase activity. These alterations might be considered as signs of tumor-promoting activity of phenobarbital