Epidemiologic-hygienic aspects of the assessment of carcinogenic risk in methacrylate production

The authors studied oncologic mortality among the workers exposed to some acryl monomers. The oncologic risk was estimated for the individuals exposed to acrylonitrile, methyl methacrylate, methyl- and butyl acrylate, methacrylic acid. Occurrence of the malignancies appeared to depend on the dose of methyl methacrylate.     

Our general chronic pain (centers for treatment chronic pain: therapeutic and organizational work principles)]

Management of chronic pain is now not only medical but a very important social and economic problem. The approaches to its management in specialized pain control centers are discussed basing on the 20-year experience of the first such center in Russia: pain control clinic with therapeutic and diagnostic center "Integrative Medicine" at Research Center of Surgery. The problems of personnel for such pain control centers, cost-effect issues, diagnostic and therapeutic methods including an advanced technique, resonance electropuncture analgesia and therapy, are reviewed.     

Carbohydrate hydrolysis and absorption in the human small intestine in aging

Veterinary dental materials (e.g. documents, images, continuing education courses, message boards, bibliographic search options) that are available as electronic media are described. These include materials available on the Internet or via commercial on-line services such as AOL-VIN and Compuserve-NOAH, and off-line materials such as CD-i, CD-ROM and floppy disk programs.     

Insulin concentration in plasma from the femoral, hepatic and pancreatico-duodenal veins of dogs under standard conditions and in corisone glucose tolerance tests

In comparing the results of glucose tolerance tests conducted against the background of cortisone action and without it the former one proved to have advantages over the latter one in studying the incretory function of the pancreas. A biphasic character of insulin secretion in glucose loading was revealed with the aid of this test. Secretion of insulin by the pancreas was better reflected by the dynamics of insulin content in the blood of the pancreatic-duodenal vein that by the dynamics of its content in the blood of the peripheral veins.     

Typing of freshly isolated strains of Salmonella typhi using bacteriophages and colicins

The effect of ketamine administered to 20 rabbits in a single dose and in fractionated doses on the blood clotting system was studied. The following blood clotting indices were determined: thrombelastography (TEG), plasma thrombin time, platelet count, euglobulin lysis time. No statistically significant differences were observed in the activity of clotting and fibrinolysis systems in the group of animals receiving a single dose of ketamine and in the group receiving fractionated doses. The obtained results suggest that ketamine as an agent used for dissociative anaesthesia can be administered safely in serious conditions associated with disturbances in the haemostasis system.     

Lack of evidence for a polymorphism at codon 160 of human O6-alkylguanine-DNA alkyltransferase gene in normal tissue and cancer

O6-benzylguanine (BG) is a potent, specific inactivator of the DNA repair protein O6-alkylguanine-DNA alkyltransferase (AGT), which enhances sensitivity to nitrosoureas in cells and tumor-bearing animals. BG is presently undergoing clinical trials for development as an agent to enhance the therapeutic index of alkylating agent chemotherapy. It has been reported that a polymorphism exists in the human agt gene, with about 15% of the Japanese population having arginine at codon 160 instead of glycine on the polypeptide (Y. Imai et al., Carcinogenesis, 16: 2441-2445, 1995). The resultant mutant AGT protein is equally effective against both methylated DNA as compared with wild type protein. However, this mutant AGT protein was less sensitive to inactivation by BG with a 20-fold increase in the ED50 value. This observation raised the possibility that a subpopulation of patients may be resistant to BG due to a single base change. We have demonstrated that this alteration also reduces the sensitivity to O6-benzyl-8-oxoguanine, an equally potent, yet much longer-lived human metabolite of BG. To test the possibility that this germ-line mutation of the agt gene might explain resistance to BG and O6-benzyl-8-oxoguanine of patients on our Phase I clinical trials, we evaluated the DNA from lymphocytes of 18 patients. The G160R mutation was not found in any of the 18 patients. To determine the frequency of this mutation in the United States population, DNA from 181 healthy individuals were investigated and, again, the mutation was not observed in this cohort. Therefore, if the mutation exists, it is in statistically <1.6% of the United States noncancerous population. To investigate the possibility that this mutation might be somatic, we evaluated genomic DNA samples from 94 human primary cancers of four different histological subtypes (brain, colon, esophageal, and head and neck). Again, none were found to have the G160R mutation.