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1.
Psychosom Med ; 63(6): 874-80, 2001.
Article in English | MEDLINE | ID: mdl-11719624

ABSTRACT

OBJECTIVE: First popularized as neurasthenia in the late 1800s by American George Beard, asthenia has been viewed by Russian psychologists and flight surgeons as a major problem that affects cosmonauts participating in long-duration space missions. However, there is some controversy about whether this syndrome exists in space; this controversy is attributable in part to the fact that it is not recognized in the current American psychiatric diagnostic system. METHODS: To address this issue empirically, we retrospectively examined the data from our 4 1/2-year, NASA-funded study of crew member and mission control interactions during the Shuttle/Mir space program. Three of the authors identified eight items of stage 1 asthenia from one of our measures, the Profile of Mood States (POMS). Scores on these items from 13 Russian and American crew members were compared with scores derived from the opinions of six Russian space experts. RESULTS: Crew members' scores in space were significantly lower than the experts' scores on seven of the eight items, and they generally were in the "not at all" to "a little" range of the item scales. There were no differences in mean scores before and after launch or across the four quarters of the missions. There were no differences in response between Russian and American crew members. CONCLUSIONS: We could not demonstrate the presence of asthenia in space as operationally defined using the POMS. However, the POMS addresses only emotional and not physiological aspects of the syndrome, and the subject responses in our study generally were skewed toward the positive end of the scales. Further research on this syndrome needs to be done and should include physiological measures and measures that are specific to asthenia.


Subject(s)
Asthenia/diagnosis , Space Flight , Adult , Cross-Cultural Comparison , Diagnostic Errors , Female , Humans , Male , Middle Aged , Mood Disorders/diagnosis , Retrospective Studies , Russia , Severity of Illness Index , Time Factors , United States
2.
Acta Astronaut ; 49(3-10): 243-60, 2001.
Article in English | MEDLINE | ID: mdl-11669114

ABSTRACT

BACKGROUND: Anecdotal reports from space and results from simulation studies on Earth have suggested that space crewmembers may experience decrements in their interpersonal environment over time and may displace tension and dysphoria to mission control personnel. METHODS: To evaluate these issues, we studied 5 American astronauts, 8 Russian cosmonauts, and 42 American and 16 Russian mission control personnel who participated in the Shuttle/Mir space program. Subjects completed questions from subscales of the Profile of Mood States, the Group Environment Scale, and the Work Environment Scale on a weekly basis before, during, and after the missions. RESULTS: Among the crewmembers, there was little evidence for significant time effects based on triphasic (U-shaped) or linear models for the 21 subscales tested, although the presence of an initial novelty effect that declined over time was found in three subscales for the astronauts. Compared with work groups on Earth, the crewmembers reported less dysphoria and perceived their crew environment as more constraining, cohesive, and guided by leadership. There was no change in ratings of mood and interpersonal environment before, during, and after the missions. CONCLUSIONS: There was little support for the presence of a moderate to strong time effect that influenced the space crews. Crewmembers perceived their work environment differently from people on Earth, and they demonstrated equanimity in mood and group perceptions, both in space and on the ground. Grant numbers: NAS9-19411.


Subject(s)
Adaptation, Psychological , Astronauts/psychology , Interpersonal Relations , Space Flight , Weightlessness , Aerospace Medicine , Affect , Group Processes , Humans , Models, Psychological , Regression Analysis , Russia , Social Isolation/psychology , Surveys and Questionnaires , United States
3.
Aviat Space Environ Med ; 72(5): 453-61, 2001 May.
Article in English | MEDLINE | ID: mdl-11346012

ABSTRACT

BACKGROUND: Anecdotal reports from space and results from simulation studies on Earth have suggested that space crewmembers may experience decrements in their mood and interpersonal environment during the 2nd half of the mission and that negative emotions may be displaced to outside monitoring personnel. METHODS: To evaluate these issues, we studied 5 American astronauts, 8 Russian cosmonauts, and 42 American and 16 Russian mission control personnel who participated in the Shuttle/Mir space program. Subjects completed questions from the Profile of Mood States, the Group Environment Scale (GES), and the Work Environment Scale (WES) on a weekly basis during the missions. Subscale scores from these measures were analyzed using a piecewise linear regression approach that analyzed normally distributed subscales using a mixed model and non-normally distributed subscales by dichotomizing the variables and using a generalized estimating equation. RESULTS: After protecting against possible Type I errors due to multiple significance tests, only weak support was found for the biphasic model: the only significant findings in favor of the hypothesized 2nd half decrements in the interpersonal environment were in crewmember GES Leader Support and astronaut WES Work Pressure. Strongly consistent confirmation was found on all six tested measures for the hypothesized displacement of tension and dysphoria from crewmembers to mission control personnel. The hypothesized displacement of tension and dysphoria from mission control personnel to management was found on five of the six tested measures. CONCLUSIONS: The absence of moderate to strong support for the biphasic model suggests that crewmember interpersonal functioning does not depend appreciably on 1st half/2nd half time effects. The consistent support found for the displacement of tension and dysphoria suggests that countermeasures need to be developed to deal with this phenomenon in both crewmembers and mission control personnel.


Subject(s)
Astronauts/psychology , Displacement, Psychological , Interprofessional Relations , Space Flight , Humans , Linear Models , Surveys and Questionnaires , Time Factors
4.
Gravit Space Biol Bull ; 14(2): 35-45, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11865867

ABSTRACT

Important psychosocial issues involving tension, cohesion, leader support, and displacement of negative emotions were evaluated in a 4 1/2-year study involving five U.S. and four Russian Shuttle/Mir space missions. Weekly mood and group climate questionnaires were completed by five U.S. astronauts, eight Russian cosmonauts, and 42 U.S. and 16 Russian mission control subjects. There were few findings that supported our hypothesized changes in tension, cohesion, and leader support in crew and ground subjects using various time models, although crewmembers reported decreasing leader support in the 2nd half of the missions, and astronauts showed some evidence of a novelty effect in the first few weeks. There was no evidence suggesting a 3rd quarter effect among crewmembers on any of the 21 subscales evaluated. In contrast, there was strong evidence to support the hypothesized displacement of tension and negative emotions from crewmembers to mission control personnel and from mission control personnel to management. There were several significant differences in response between Americans vs. Russians, crewmembers vs. mission control personnel, and subjects in this study vs. people in comparable groups on Earth. Subject responses before, during, and after the missions were similar, and we did not find evidence for asthenia in space. Critical incidents that were reported generally dealt with events on-board the Mir and interpersonal conflicts, although most of the responses were from a relatively small number of subjects. Our findings have implications for future training and lead to a number of countermeasures.


Subject(s)
Adaptation, Psychological , Astronauts/psychology , Cross-Cultural Comparison , Space Flight , Weightlessness , Aerospace Medicine , Affect , Asthenia/psychology , Displacement, Psychological , Group Processes , Humans , Interpersonal Relations , Russia , Social Isolation/psychology , Stress, Psychological , Surveys and Questionnaires , United States
5.
Acta Astronaut ; 48(5-12): 777-84, 2001.
Article in English | MEDLINE | ID: mdl-11858274

ABSTRACT

To improve the interpersonal climate of crewmembers involved with long-duration space missions, it is important to understand the factors affecting their interactions with each other and with members of mission control. This paper will present findings from a recently completed NASA-funded study during the Shuttle/Mir program which evaluated in-group/out-group displacement of negative emotions; changes in tension, cohesion, and leader support over time; and cultural differences. In-flight data were collected from 5 astronauts, 8 cosmonauts, and 42 American and 16 Russian mission control personnel who signed informed consent. Subjects completed a weekly questionnaire that assessed their mood and perception of their work group's interpersonal climate using questions from well-known, standardized measures (Profile of Mood States, Group and Work Environment Scales) and a critical incident log. There was strong evidence for the displacement of tension and dysphoric emotions from crewmembers to mission control personnel and from mission control personnel to management. There was a perceived decrease in commander support during the 2nd half of the missions, and for American crewmembers a novelty effect was found on several subscales during the first few months on-orbit. There were a number of differences between American and Russian responses which suggested that the former were less happy with their interpersonal environment than the latter. Mission control personnel reported more tension and dysphoria than crewmembers, although both groups scored better than other work groups on Earth. Nearly all reported critical incidents came from ground subjects, with Americans and Russians showing important differences in response frequencies.


Subject(s)
Astronauts/psychology , Displacement, Psychological , Interpersonal Relations , Space Flight , Weightlessness , Adaptation, Psychological , Affect , Cross-Cultural Comparison , Group Processes , Humans , Russia , Stress, Psychological , Surveys and Questionnaires , United States
6.
Aviat Space Environ Med ; 71(9 Suppl): A11-6, 2000 Sep.
Article in English | MEDLINE | ID: mdl-10993303

ABSTRACT

BACKGROUND: Anecdotal reports from space and results from simulation studies on Earth suggest that interpersonal and cultural issues will have an impact on the interactions of crewmembers and mission control personnel during future long-duration space missions. METHODS: To evaluate this impact we studied 5 astronauts, 8 cosmonauts, and 42 American and 16 Russian mission control personnel who participated in the Shuttle/Mir space program. Subjects completed questions from the Profile of Mood States, the Group Environment Scale, and the Work Environment Scale on a weekly basis during the missions. Subscale scores from these measures were analyzed using a two-way ANOVA to examine mean differences as a function of country (American vs. Russian), group (crewmember vs. ground personnel), and their interaction. RESULTS: Americans scored higher on measures of vigor and work pressure, and Russians scored higher on measures of managerial control, task orientation, physical comfort, self discovery, and leader support (which also showed a significant interaction effect). Mission control subjects scored higher than crewmembers on four measures of dysphoric emotions, but both groups scored significantly lower than published norms from other studies. There were significant interaction effects for subscales measuring leader support, expressiveness, and independence, with the American astronauts scoring the lowest of all comparison groups on all three subscales. CONCLUSIONS: In future long-duration space missions, countermeasures should focus on providing support for crewmembers from a culture in the minority, and crews should include more than one representative from this culture. Positive aspects of the interpersonal environment should be enhanced. The needs of mission control personnel should be addressed as well as those of crewmembers.


Subject(s)
Affect , Interpersonal Relations , Space Flight , Time Factors , Adult , Cultural Characteristics , Female , Humans , International Cooperation , Male , Russia/ethnology , Stress, Psychological , United States/ethnology
7.
Acta Astronaut ; 47(2-9): 647-55, 2000.
Article in English | MEDLINE | ID: mdl-11708371

ABSTRACT

A number of interpersonal issues relevant to manned space missions have been identified from the literature. These include crew tension, cohesion, leadership, language and cultural factors, and displacement. Ground-based studies by others and us have clarified some of the parameters of these issues and have indicated ways in which they could be studied during actual space missions. In this paper, we summarize some of our findings related to social and cultural issues from a NASA-funded study conducted during several Shuttle/Mir space missions. We used standardized mood and group climate measures that were completed on a weekly basis by American and Russian crew and mission control subjects who participated in these missions. Our results indicated that American subjects reported more dissatisfaction with their interpersonal environment than their Russian counterparts, especially American astronauts. Mission control personnel were more dysphoric than crewmembers, but both groups were significantly less dysphoric than other work groups on Earth. Countermeasures based on our findings are discussed which can be applied to future multicultural space missions.


Subject(s)
Astronauts/psychology , Cross-Cultural Comparison , Social Isolation , Space Flight , Weightlessness , Adaptation, Psychological , Aerospace Medicine , Female , Group Processes , Humans , International Cooperation , Interpersonal Relations , Male , Psychological Tests , Russia , Stress, Psychological , United States
8.
J Basic Microbiol ; 38(4): 241-55, 1998.
Article in English | MEDLINE | ID: mdl-9791947

ABSTRACT

474 strains of the actinomycete genera Streptomyces (including species of the former genera Chainia and Streptoverticillium), Pseudonocardia and Micromonospora were examined for their ability to degrade quinate (Q) and p-hydroxybenzoate (pHB); selected strains were also tested for their capacity to catabolize benzoate (B). Whereas in the case of Q (5-10 g/l of a mineral salts agar medium) the growth response signalizes assimilation, pHB has to be supplied in lower concentration (routinely 0.3 g/l together with small amounts of peptone and yeast extract in liquid broth), and its degradation has to be determined spectrophotometrically. 27% of the streptomycete strains were able to grow with Q, and 57% with pHB. The three strains of "Chainia" that were tested metabolized Q and pHB, but none of the fourty species of "Streptoverticillium" showed this ability. 80% of the 30 strains of Psn. autotrophica grew with Q, and 100% degraded pHB and B. Two of the five Micromonospora strains gave a positive response with pHB, but not with Q.-Toluene treated cells (preincubated with Q, pHB or B, respectively) gave a positive Rothera reaction with protocatechuate or catechol respectively, thus demonstrating that these organisms employed the beta-ketoadipate pathway (orthofission) for the degradation of Q, pHB and B. The assay of five relevant enzymes in cell-free extracts of nine selected organisms showed that in nocardioform actinomycetes (Pseudonocardia, Rhodococcus) all enzymes of the protocatechuate branch of the ketoadipate pathway seem to be induced by beta-ketoadipate as demonstrated here for protocatechuate-3,4-dioxygenase. In contrast, in Streptomyces this enzyme appears to be induced by its substrate, protocatechuate, whereas the regulation of the other enzymes of this pathway remains to be elucidated.


Subject(s)
2,4-Dichlorophenoxyacetic Acid/analogs & derivatives , Parabens/metabolism , Quinic Acid/metabolism , Streptomyces/classification , Streptomyces/enzymology , 2,4-Dichlorophenoxyacetic Acid/metabolism , Actinomycetales/classification , Actinomycetales/enzymology , Actinomycetales/metabolism , Benzoates/metabolism , Biodegradation, Environmental , Catechols/metabolism , Protocatechuate-3,4-Dioxygenase/metabolism , Shikimic Acid/metabolism , Soil Microbiology , Streptomyces/metabolism
9.
Vaccine ; 16(1): 92-8, 1998 Jan.
Article in English | MEDLINE | ID: mdl-9607015

ABSTRACT

The adjuvant activity of poly[di(carboxylatophenoxy)phosphazene] (PCPP) on the immunogenicity of formalin-inactivated influenza virions and commercial trivalent influenza vaccine was studied. Regardless of which antigen preparation is used, the addition of 100 micrograms PCPP enhances the HAI antibody response 10-fold over the levels elicited by the vaccine alone. Similarly, PCPP enhanced the IgM, IgG, and IgG1 ELISA antibody titers to influenza antigens at least 10-fold higher than the vaccine alone. In contrast, the IgG2a isotype titers were only enhanced about 2-fold. Immunization of aged mice (22 months old) with trivalent influenza vaccine alone did not sero-convert these mice as measured by HAI or ELISA whereas significant sero-conversion was achieved when mice were immunized with PCPP-formulated trivalent vaccine. The adjuvant activity of PCPP was shown to not be due to a site of injection depot effect. PCPP adjuvanticity was positively correlated to the molecular weight of the polymer.


Subject(s)
Adjuvants, Immunologic , Antibodies, Viral/immunology , Influenza Vaccines/immunology , Organophosphorus Compounds , Orthomyxoviridae/immunology , Polymers , Virion/immunology , Adjuvants, Immunologic/chemistry , Animals , Female , Mice , Mice, Inbred BALB C , Molecular Weight , Organophosphorus Compounds/chemistry , Polymers/chemistry
10.
J Fluoresc ; 4(4): 365-6, 1994 Dec.
Article in English | MEDLINE | ID: mdl-24233617

ABSTRACT

We synthesized two isomeric alkyldiacyl glycerols containing pyrene as a fluorescent reporter group bound to the omega end of both acyl chains. If located in the phospholipid monolayer of a vesicle both isomers showed intramolecular pyrene excimer fluorescence, indicating parallel orientation of both pyreneacyl chains in the lipid molecule. In micelles only pyrene monomer fluorescence was observed. Thus, in this system the labeled lipids adopt a conformation with both pyreneacyl chains extending into different directions. Using vesicles, lipase activities could be continuously determined from the increase of pyrene monomer fluorescence.

11.
Appl Environ Microbiol ; 58(12): 4068-71, 1992 Dec.
Article in English | MEDLINE | ID: mdl-1476446

ABSTRACT

Strains of Arthrobacter catalyze a hydrolytic dehalogenation of 4-chlorobenzoate (4-CBA) to p-hydroxybenzoate. The reaction requires ATP and coenzyme A (CoA), indicating activation of the substrate via a thioester, like that reported for Pseudomonas sp. strain CBS3 (J. D. Scholten, K.-H. Chang, P. C. Babbit, H. Charest, M. Sylvestre, and D. Dunaway-Mariano, Science 253:182-185, 1991). The dehalogenase genes of Arthrobacter sp. strain SU were cloned and expressed in Escherichia coli. Analyses of deletions indicate that dehalogenation depends on three open reading frames (ORFs) which are organized in an operon. There is extensive sequence homology to corresponding gene products in Pseudomonas sp. strain CBS3, suggesting that ORF1 and ORF2 encode a 4-CBA-CoA-ligase and a 4-CBA-CoA dehalogenase, respectively. ORF3 possibly represents a thioesterase, although no homology to the enzyme from Pseudomonas sp. strain CBS3 exists.


Subject(s)
Arthrobacter/genetics , Arthrobacter/metabolism , Chlorobenzoates/metabolism , Genes, Bacterial , Hydrolases/genetics , Amino Acid Sequence , Base Sequence , Biodegradation, Environmental , Chromosome Mapping , Cloning, Molecular , DNA, Bacterial/genetics , Gene Expression Regulation, Bacterial , Molecular Sequence Data , Open Reading Frames , Operon
12.
Appl Environ Microbiol ; 58(6): 1874-7, 1992 Jun.
Article in English | MEDLINE | ID: mdl-1622263

ABSTRACT

Rhodococcus sp. strain B4, isolated from a soil sample contaminated with polycyclic aromatic hydrocarbons, grows with naphthalene as the sole source of carbon and energy. Salicylate and gentisate were identified as intermediates in the catabolism of naphthalene. In contrast to the well-studied catabolic pathway encoded by the NAH7 plasmid of Pseudomonas putida, salicylate does not induce the genes of the naphthalene-degradative pathway in Rhodococcus sp. strain B4. The key enzymes of naphthalene degradation in Rhodococcus sp. strain B4 have unusual cofactor requirements. The 1,2-dihydroxynaphthalene oxygenase activity depends on NADH and the salicylate 5-hydroxylase requires NADPH, ATP, and coenzyme A.


Subject(s)
Gentisates , Naphthalenes/metabolism , Rhodococcus/metabolism , Biodegradation, Environmental , Hydroxybenzoates/metabolism , Mixed Function Oxygenases/metabolism , NADP/metabolism , Oxygen Consumption , Rhodococcus/growth & development , Rhodococcus/isolation & purification , Salicylates/metabolism , Salicylic Acid , Soil Microbiology , Species Specificity
13.
Appl Environ Microbiol ; 57(3): 665-71, 1991 Mar.
Article in English | MEDLINE | ID: mdl-2039229

ABSTRACT

A new plasmid, pA387, has been isolated from "Amycolatopsis sp." (DSM 43387). This plasmid could be isolated from liquid culture as well as mycelium from agar plates by a modified procedure. Plasmid pA387 is about 29.6 kb and can be cured at low frequency by protoplasting and ethidium bromide and heat treatment. Hybridization experiments showed that this plasmid is present in free form and does not integrate into the chromosome. A hybrid plasmid was constructed by cloning a 5.1-kb fragment of pA387 into the Escherichia coli vector pDM10. This hybrid plasmid, termed pRL1, could be transformed into Amycolatopsis mediterranei and A. orientalis by electroporation. A transformation frequency of 2.2 x 10(3) transformants per micrograms of DNA at 12.5 kV/cm and a pulse duration of 10.8 ms was obtained in A. mediterranei, whereas 1.1 x 10(5) transformants per microgram of DNA were obtained at a field strength of 7.5 kV/cm and a pulse duration of 7.6 ms in A. orientalis. Plasmid pRL1 is the first hybrid plasmid which could be used successfully for the transformation of A. mediterranei. The plasmid has a rather high copy number, is genetically stable, and can be easily reisolated from A. mediterranei. Plasmid pRL1 will be useful for further construction of a shuttle vector for E. coli and A. mediterranei and becomes the basis for the development of gene cloning techniques in Amycolatopsis spp.


Subject(s)
Nocardia/genetics , Plasmids , Cloning, Molecular , DNA Replication , DNA, Bacterial/genetics , Genes, Bacterial , Genetic Vectors , Restriction Mapping , Transformation, Genetic
14.
Appl Environ Microbiol ; 56(5): 1459-64, 1990 May.
Article in English | MEDLINE | ID: mdl-2339895

ABSTRACT

Eight actinomycetes of the genera Amycolatopsis and Streptomyces were tested for the degradation of aromatic compounds by growth in a liquid medium containing benzoate, monohydroxylated benzoates, or quinate as the principal carbon source. Benzoate was converted to catechol. The key intermediate in the degradation of salicylate was either catechol or gentisate, while m-hydroxybenzoate was metabolized via gentisate or protocatechuate. p-Hydroxybenzoate and quinate were converted to protocatechuate. Catechol, gentisate, and protocatechuate were cleaved by catechol 1,2-dioxygenase, gentisate 1,2-dioxygenase, and protocatechuate 3,4-dioxygenase, respectively. The requirement for glutathione in the gentisate pathway was dependent on the substrate and the particular strain. The conversion of p-hydroxybenzoate to protocatechuate by p-hydroxybenzoate hydroxylase was gratuitously induced by all substrates that were metabolized via protocatechuate as an intermediate, while protocatechuate 3,4-dioxygenase was gratuitously induced by benzoate and salicylate in two Amycolatopsis strains.


Subject(s)
Actinomycetales/metabolism , Benzoates/metabolism , Hydroxybenzoates/metabolism , Parabens/metabolism , Streptomyces/metabolism , Benzoic Acid , Glutathione/metabolism , Salicylates/metabolism , Salicylic Acid
15.
Intervirology ; 30(6): 323-9, 1989.
Article in English | MEDLINE | ID: mdl-2559901

ABSTRACT

The comparison of the Saccharomonospora phages phi SaC1, phi SaG1, phi SaV1, phi SaV2, phi SaV3, and Tm1 demonstrated that they all belong to a single group of closely related actinophages: they were similar with regard to host range, virion mophology (B1 type), genome length (43-45 kb), and GC content of their genomes (63, 3% G + C). Furthermore, DNA-DNA hybridization showed that the phage genomes had a high degree of homology to each other. The phages are, therefore, proposed as representatives of a new bacteriophage species in the sense of the ICTV.


Subject(s)
Actinomycetaceae , Bacteriophages/genetics , Bacteriophages/growth & development , Bacteriophages/ultrastructure , Base Composition , DNA Restriction Enzymes , DNA, Viral/genetics , Sequence Homology, Nucleic Acid
16.
Biochem Biophys Res Commun ; 140(3): 916-23, 1986 Nov 14.
Article in English | MEDLINE | ID: mdl-3778492

ABSTRACT

The respiratory quinone composition of 5 members of the genus Nocardia was examined. All species contained a hitherto unknown cyclic vitamin K-like molecule as their predominant lipoquinone. On the basis of mass spectrometry, 1H and 13C nuclear magnetic resonance spectrometry, the novel quinone was shown to correspond to (2E, 14E, 18E, 22E)-2-[3,7, 11,15,19,23-hexamethyl-25-(2,6,6-trimethylcyclohex-2- enyl)pentacosa-2, 14,18,22-tetraenyl]-3-methyl-1,4-naphthoquinone. Results indicate this molecule may represent a valuable phylogenetic marker for the prokaryote genus Nocardia.


Subject(s)
Nocardia/metabolism , Vitamin K 1/analogs & derivatives , Vitamin K/analogs & derivatives , Chromatography, High Pressure Liquid , Chromatography, Thin Layer , Magnetic Resonance Spectroscopy , Mass Spectrometry , Molecular Conformation , Nocardia/genetics , Phylogeny , Vitamin K/biosynthesis
18.
J Physiol ; 325: 419-21, 1982 Apr.
Article in English | MEDLINE | ID: mdl-7108781

ABSTRACT

1. The gastrin bioactivity and immunoreactivities of human, porcine and feline antral extracts were compared. 2. Human and porcine had similar activities but cat had much less. 3. The ratio of gastrin bioactivity to immunoreactivity was much greater with feline antral extracts than with human and porcine extracts.


Subject(s)
Gastrins/analysis , Pyloric Antrum/analysis , Animals , Biological Assay , Cats , Humans , Radioimmunoassay , Swine
20.
Arch Toxicol Suppl ; 4: 81-2, 1980.
Article in English | MEDLINE | ID: mdl-6933972

ABSTRACT

After administration of carcinogens to laboratory animals reduced induction of some enzymes has been found which is believed to be associated with the carcinogenic process. It is suggested that this effect may be used for the testing of chemical substances for carcinogenicity. For this purpose the dietary induction of pyruvate kinase in rat liver was investigated after feeding 2-acetylaminofluorene. The induced activity in the animals fed the carcinogen was found to be significantly lower than in the control, however, the extent of this reduction was too low to be used for testing chemical substances for carcinogenicity.


Subject(s)
2-Acetylaminofluorene/pharmacology , Liver/enzymology , Pyruvate Kinase/biosynthesis , Animals , Enzyme Induction/drug effects , Fasting , Male , Rats
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