[Genetic defects as markers of tumor development]. / Geneticheskie defekty kak markery opukholevogo rosta.

Carcinogenesis is long-term multistep accumulation of defects of genes responsible for cell division, DNA repair, and apoptosis. The functions of these genes are known both for norm and for pathologies caused by their damage and resulting in "asocial" cell behavior. Owing to the recent progress in studying the mechanisms of carcinogenesis, some genetic defects may be considered from the applied point of view (as tumor markers rather than as pathogenetic factors) and employed in diagnostics. Thus detection of mutant alleles in biological fluids (e.g., beyond the tumor) suggests higher risk of carcinogenesis. Genetic defects are a new class of tumor markers and have a substantial diagnostic potential. In contrast to known protein markers (alpha-fetoprotein, etc.) used in clinical practice, DNA markers are oncospecific (as these are in direct cause-and-effect relationships with carcinogenesis) and universal (as there is not a single tumor cell without a genetic defect). Analysis of DNA markers may be employed not only in diagnostics or tumor growth monitoring (assessment of treatment efficiency, early detection of recurrence or metastasis), but also (prospectively) in screening (tumor detection at the presymptomatic stage, identification of high-risk groups). Theoretical grounds, prospects, problems, and methods of this new field are considered.

Detection of mutant k-ras sequences in the urine of cancer patients.

DNA fragments from apoptotic cells crossing the renal barrier retain their matrix functions, which allows PCR identification of mutant sequences in excreted DNA. We investigated the possibility of detecting k-ras mutations in urinary DNA of tumor patients (colon cancer). In some patients with k-ras codon 12 mutations in tumor cell DNA the same changes were detected in the urinary DNA. The possibility of using this approach for early diagnosis and monitoring of tumors is discussed.

[Analysis of DNA excreted from the body as an approach to diagnosis and monitoring tumor growth]. / Analiz ékskretiruemoi iz organizma DNK kak podkhod k vyiavleniiu rastushchei v organizme opukholi.

Proceeding from their early data showing that some portion of DNA originating from apoptotic cells can enter the blood stream and pass through the renal barrier by preserving its template capabilities, the authors analyzed urine DNA from 29 patients with colorectal cancer. PCR was used to compare DNA samples from the normal mucosa surrounding the tumor and from the urine collected just prior to surgery. Six microsatellite loci were studied with oligonucleotide primers. The following results were obtained: i) 3 cases showed differences in one of the studied loci in normal and tissue DNA; ii) some patients displayed changes in urine DNA microsatellite loci, namely: disappearance of some alleles (loss of heterozygocity) and appearance of new ones; iii) there were no differences in microsatellite patterns of lymphocytic DNA (taken as a control) and urine DNA in healthy donors. The findings are discussed in view of current concepts of tumor clonal heterogeneity and interpreted as a promising approach to diagnosing and monitoring tumor growth.

Genetic analysis of DNA excreted in urine: a new approach for detecting specific genomic DNA sequences from cells dying in an organism.

BACKGROUND: Cell-free DNA from dying cells recently has been discovered in human blood plasma. In experiments performed on animals and humans, we examined whether this cell-free DNA can cross the kidney barrier and be used as a diagnostic tool. METHODS: Mice received subcutaneous injections of either human Raji cells or purified (32)P-labeled DNA. DNA was isolated from urine and analyzed by measurement of radioactivity, agarose gel electrophoresis, and PCR. In humans, the permeability of the kidney barrier to polymeric DNA was assessed by detection in urine of sequences that were different from an organism bulk nuclear DNA. RESULTS: In the experiments on laboratory animals, we found that approximately 0.06% of injected DNA was excreted into urine within 3 days in a polymeric form and that human-specific ALU: sequences that passed through the kidneys could be amplified by PCR. In humans, male-specific sequences could be detected in the urine of females who had been transfused with male blood as well as in DNA isolated from urine of women pregnant with male fetuses. K-ras mutations were detected in the urine of patients with colon adenocarcinomas and pancreatic carcinomas. CONCLUSIONS: The data suggest that the kidney barrier in rodents and humans is permeable to DNA molecules large enough to be analyzed by standard genetic methodologies.

[Antihypertensive efficacy, tolerance and safety of lisinopril (sinopril) and captopril (capoten) in patients with mild and moderate arterial hypertension]. / Antigipertenzivnaia éffektivnost', perenosimost' i bezopasnost' lizinoprila (sinoprida) i kaptoprila (kapotena) u bol'nykh miagkoi i umerennoi arterial'noi gipertoniei.

AIM: To compare effectiveness, tolerance and safety of two inhibitors of angiotensin-converting enzyme--sinopril (lisinopril) and capoten (captopril)--in outpatient treatment of patients with mild and moderate hypertension. MATERIALS AND METHODS: The patients were randomly assigned to sinopril or capoten groups. Sinopril was given in daily dose 10-40 mg, capoten--in daily dose 25-100 mg for 8 weeks. In insufficient antihypertensive effect of monotherapy on day 21, hydrochlortiaside was added. The effect was judged by influence on arterial pressure, heart rate, tolerance (questionnaire), safety (blood count, urinalysis. ECG). RESULTS: Sinopril produced good antihypertensive effect in 73.3% of patients (monotherapy) and 88.9% (combined therapy). For capoten it was 68.9 and 82.2%, respectively. The time of the beginning of the antihypertensive effect (4-20 days after the start of the treatment) for sinopril and copoten differed insignificantly and depended on hypertension severity (mild or moderate). Tolerance of both drugs was good, serious side effects were absent. Discontinuation of the drugs was needed in 4% of patients, only. No negative action on bioelectric activity of the heart, clinical and biochemical blood indices were found. CONCLUSION: Sinopril and capoten demonstrate high antihypertensive activity.

[A preclinical trial of iodoantipyrine safety]. / Doklinicheskaia otsenka bezopasnosti iodantipirina.

Detailed preclinical study of the safety of the new antiviral agent iodantipyrine was conducted. In LD50 parameters it was found to be related to moderately toxic drugs. Long-term administration in doses of 50, 100, and 250 mg/kg did not cause any essential functional and structural disorders in the organs and systems of rats and dogs. Iodantipyrine does not possess mutagenic and allergenic properties and does not affect the reproductive function.

[Opposite effect of p53 on nucleotide metabolizing enzyme activity in Rat1 cells and their sublines, transformed by N-RAS or v-mos oncogenes]. / Protivopolozhnye éffekty p53 na aktivnost' fermentov nukleinovogo obmena v kletkakh Rat1 i ikh subliniiakh, transformirovannykh onkogenami N-RAS ili v-mos.

The effects of exogenous human p53 and its various mutants (Ala-141, His-175, His-194, Trp-248, His-273) on two key enzymes of purine uptake, adenosine deaminase (AD) and hypoxanthine phosphoribosyl transferase (HPRT), has been studied in Rat 1 immortalized fibroblasts and their sublines transformed by N-RAS or v-mos oncogenes. Introduction into Rat1 cells of both wild type (wt) and mutant p53 produced a 2- to 7.5-fold increase in the AD activity, p53 mutants having a stronger effect than p53wt. In contrast, the HPRT activity decreased 8- to 10-fold in cells containing exogenous p53wt, while p53 mutants partly lost their ability to inhibit HPRT. Transformation of Rat1 by ras or mos oncogenes was also accompanied by an increase in the AD activity (4-5-fold and 1.5-2-fold, respectively) as well as by suppression of HPRT (20-fold and 2-fold, respectively). However, simultaneous expression of exogenous p53 and ras or p53 and mos produced opposite effects, i.e., a dramatic decrease in the AD activity and complete (p53wt, His-273) or partial (His-175, Trp-248) restoration of the HPRT activity. Possible functional significance and mechanisms of AD and HPRT regulation by p53 as well as the role of modifications of activity of nucleotide synthesis enzymes in the cooperative effect of predominant oncogenes and mutant p53 oncogenes in tumour transformation are discussed.

Alterations of (CA)n DNA repeats and tumor suppressor genes in human gastric cancer.

We have examined whether alterations of simple (CA)n DNA repeats, as observed in human colon cancers, occur during human gastric carcinogenesis and whether such alterations reflect genomic instability that could lead to other genetic changes. A total of 22 gastric cancer samples were analyzed: 15 well or moderately differentiated adenocarcinomas, 6 signet-ring cell carcinomas, and 1 poorly differentiated adenocarcinoma. When (CA)n repeat sequences were examined at 10 loci, one adenocarcinoma showed a loss of repeat sequences at five loci, three adenocarcinomas gained a repeat at one locus, and one adenocarcinoma had new, repeated sequences at five loci. Three samples showed mutations in the p53 gene, two in exon 5 (both GC to AT transition at a CpG dinucleotide) and one in exon 7 (AT to GC transition). Only one sample with a p53 mutation also showed altered (CA)n repeats. A putative tumor suppressor gene, connexin 32, was not altered as assessed by single-strand conformation polymorphism analysis. These results suggest that genomic instability revealed by (CA)n repeat changes does not seem to contribute to induction of point mutations in p53 or connexin 32 genes but may participate in loss of heterozygosity at APC/MCC loci. The results are consistent with the hypothesis that different mechanisms are involved in the gain and loss of (CA)n repeats.

Human p53, mutated at codon 273, causes distinct effects on nucleotide biosynthesis salvage pathway key enzymes in Rat-1 cells and in their derivatives expressing activated ras oncogene.

The introduction of human p53 with mutation at codon 273 into Rat-1 cells induces changes in the salvage pathway of nucleotide synthesis. In cells expressing the mutant p53 the activities of hypoxanthine phosphoribosyl transferase (HPRT) and thymidide kinase (TK) decrease 3.5- and 2-3-fold, respectively, while the activities of adenosine deaminase and uridine kinase, in contrast, increase correspondingly 2.5- and 1.5-fold. On the other hand, in cells transformed by ras oncogene, which causes dramatical reduction in HPRT activity as well as enhancement of TK function, the expression of exogeneous p53 leads to the opposite effects and causes the reversion of activities of both enzymes to the levels found in parental cells.

[The function of 2 detoxifying body systems in workers of the petrochemical industry]. / Sostoianie dvukh detoksitsiruiushchikh sistem organizma u rabotnikov neftekhimicheskogo proizvodstva.

Studies of the immune status and antipyrine test helped to analyse the status of the two body detoxicants--the immune system and the system of microsomal hepatic oxygenases in petrochemical production workers suffering from the chronic bronchitis and bronchial asthma. Immune deficiency of T and B cells, decreased function of cytochrome P-450 containing monooxygenase system were revealed, which indicates complicated relations between the two body detoxicant systems.

[Comparative analysis of indicators of the immune status of population of the Eastern regions of the USSR]. / Sravnitel'nyi analiz pokazatelei immunnogo statusa naseleniia vostochnykh regionov SSSR.

Altogether 1,500 healthy residents of seven cities situated in the Asian part of the USSR were examined. In Novosibirsk, Tomsk, Tyumen, Norilsk, Magadan, Yakutsk and Ussuriisk, the people were examined for the blood levels of T and B lymphocytes, the ratio of regulatory subclasses of T lymphocytes, the concentration of IgG, IgM and IgA, and for the content of immune complexes. Analysis was made of the general and regional regularities in changes seen in the immune system depending on climatic and geographic factors. Parameters of the populations similarity in the regions with different environmental conditions were delineated.

[Complex study of various pathogenetic and physiologic parameters of the health status of watchmen in the oil industry]. / Kompleksnoe izuchenie nekotorykh tsitogeneticheskikh i fiziologicheskikh parametrov zdorov'ia u vakhtovykh rabochikh-neftianikov.

Complex examination of oil industry workers and those engaged in nonproductive area (control group) was undertaken. It was established that in both groups there were persons with a high level of cells with cytogenetic disturbances (micronuclear test). However, as opposed to control group, oil industry workers had higher levels of systolic and pulse pressure. Besides it was shown that after 12 hours of work at an oil field under winter conditions in the north area of the Tomsk Region they had higher body temperature. It appeared that these persons primarily had the longest term of professional service. Further examination of persons with especially high level of micronuclei cells showed that they had elevated lymphocyte amount with chromosome impairments and some parameters of T- and B-immunoreactivity, phagocytosis and activity of normal killer cells were changed.

[The pool of free purine and pyrimidine nucleosides and bases in the thymocytes, and splenic T- and B-lymphocytes of C3HA mice during the growth of solid hepatoma 22a]. / Analiz pula svobodnykh purinovykh i pirimidinovykh nukleozidov i osnovanii v timotsitakh, T- i B-limfotsitakh selezenki myshei C3HA v protsesse rosta solidnoi gepatomy 22a.

Using reverse phase ion pair high performance liquid chromatography, the levels of free adenosine, inosine, adenine, xanthine, hypoxanthine, guanine and deoxycytidine in thymocytes and splenic T- and B-lymphocytes of C3HA mice, were studied under normal conditions and at different times (5 hrs, 1, 2, 3, 4, 5, 8 and 20 days) after transplantation of solid hepatoma 22a. The adenosine and inosine levels in thymus and spleen lymphocytes were 5 to 10 times as low as that of purine bases. Inosine was totally absent in T-and B-lymphocytes. The absolute content of adenine and guanine in thymus and spleen lymphocytes was higher compared to purine bases. It was shown that in all cases studied the decrease in hypoxanthine, xanthine and guanine levels in T- and B-lymphocytes during maximal tumour growth, i.e., on the 5th and 8th post-inoculation days as well as at the terminal period (20th day), was correlated with the decrease in the adenosine deaminase and functional activities of these cells. The level of free adenine in thymocytes and spleen T-lymphocytes during tumour growth showed a 2-4-fold increase in comparison with normal values. A dramatic decrease of intracellular concentration of deoxycytidine was observed in thymocytes and spleen T- and B-lymphocytes beginning with the 5th hour and over the whole subsequent period. The key role of the deoxycytidine decline during tumour growth as a possible cause of simultaneous impairment of DNA synthesis and purine deoxyribonucleoside phosphorylation in lymphocytes is discussed.

[Change in activity of enzymes for purine metabolism and RNA and DNA biosynthesis in macrophages, reflecting impairment of their functions in neoplastic growth]. / Izmenenie aktivnosti fermentov purinovogo obmena i biosinteza RNK i DNK v makrofagakh, otrazhaiushchie narushenie ikh funktsii pri zlokachestvennom roste.

The changes in the biochemical parameters of peritoneal macrophages and their coupling to the secretory and phagocytic functions in CH3A mice during the growth of the reinoculated solid hepatoma 22a were studied. The DNA and RNA synthesis during the active tumour growth was more intense than that in resident macrophages. The activity of uridine kinase increased up to 156.0 +/- 12.0 nmol/hour/10(8) but was absent in resident macrophages. This was accompanied by a 7.2-fold increase of interleukin-1 synthesis as determined by the [3H]thymidine incorporation into thymocyte DNA in response to concanavalin A administration to C3H mice. Similar changes were observed in peptone-stimulated macrophages. A specific feature of macrophages from tumour-bearing mice was the impairment of activity of purine exchange enzymes and the efficiency of phagocytosis that were unobserved in peptone-stimulated macrophages. The activity of adenosine deaminase and purine nucleoside phosphorylase was inhibited as a result of their preincubation with zymosan, a phagocytosis-stimulating agent. This was accompanied by a significant decrease of the first chemiluminescence peak resulting from disturbances in Fc-reception. Macrophages of tumour-bearing animals possessed an increased 2.2-fold activity of membrane-bound AMP 5'-nucleotidase concomitant with the lack or decrease of the amplitude of the second chemiluminescence peak reflecting the disturbances in digestion resulting from phagocytosis.