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D H Moore

Publications and source records attributed to D H Moore.

At least 163 records · Page 9Linked to original sources
PubMed1980

Variation in the baseline sister chromatid exchange frequency in human lymphocytes.

The utility of the sister chromatid exchange (SCE) assay for human population studies is potentially limited by the variability associated with individual baseline SCE Frequencies. This investigation identifies and quantifies the major sources of preparative and biological variation associated with the determination of baseline SCE frequencies in cultured human lymphocytes. Much of the variation in lymphocyte SCE frequencies is attributable to the amount of bromodeoxyuridine (BrdUrd) available per lymphocyte; the pooled coefficient of variation (CV) over the dose range of 10 to 160 micrometer is about 18%. Other variations in the baseline frequency result from culture-to-culture and slide-to-slide differences. The pooled coefficient of variation among donors is about 10%. The effect of cell-to-cell differences in baseline SCE frequency among donors can be minimized by increasing the number of cells scored per donor. When 20 cells are analyzed per individual the pooled cell-to-cell variation is 9% but when 40 or 80 cells are analyzed it is reduced to 6 and 4% respectively. For a single individual the cell-to-cell coefficient of variation at 100 micrometer BrdUrd is 40.8%. Under our experimental conditions, a 30% increase in SCE frequency between two cohort populations can be detected with a 95% probability at a 5% level of significance when 11 individuals per cohort are studied. For a longitudinal or in vitro dose response study of a single individual, a 50% increase in SCE frequency can be detected with a 95% probability at a 5% level of significance when 25 cells per sample are analyzed. These results indicate the feasibility of applying the SCE bioassay to humans as a measure of environmental stress.

Biological Assay↗
PubMed1979

Bioactivities and the effect of dilution on various milk-borne murine mammary tumor viruses.

Infectivity titrations of milk-borne murine mammary tumor virus (MuMTV) from different sources or prepared in different ways or stored for periods of time have been compared. Titration curves were in general reproducible for MuMTVs of different sources or handled in different ways and for different methods of measurement, such as hyperplastic alveolar nodule (HAN) development, tumor development, or MuMTV antigen secretion in third-lactation milk, The curves had characteristic shapes with a low incidence of infection at low dilutions of milk, high incidences at intermediate dilutions, and low incidences at high dilutions. Infectivity incidences were unaffected by dilution over the range 10(-2) to 10(-5). The curves did not change appreciably with time of storage of milk at liquid N2 temperature for periods up to 3 years. Rate zonal fractionation of RIII milk gave zones with bioactivities which were not proportional to B-particle content. Upon dilution, the bioactivity of Zone 3, rich in B particles, and Zone 5, poor in B particles, increased, while the bioactivity of all the other zones usually decreased with dilution. The low incidence of infection at low dilutions may have been due, in part, to an immune response of the inoculated mouse. Administration of inactivated virions 4 h prior to or with MuMTV inoculations gave some evidence in support of this hypothesis but the complexity of the bioassay system for MuMTV lends uncertainty to interpretation of results.

Age Factors↗
PubMed1979

Idiopathic mammary tumors in BALB/c mice.

A colony of BALB/c mice consisting of two sublines with a high incidence of mammary tumors was examined for the presence of a mammary tumor virus (MuMTV). The mammary tumor incidences in the two sublines were 18% and 35% at average tumor age 19-20 months. Over a period of 8 years, their milk at third to tenth lactations were monitored for the presence of MuMTV antigen,and the milk and tumors were examined for the presence of B particles. Neither antigen nor B particles were found. Milk and tumor extracts from the higher mammary tumor lines were also assayed for MuMTV bioactivity by intraperitoneal inoculation of weanling C57BL, BALB/c, and RIIIf females. No response was obtained, except possible in RIIIf. Both the MuMTV antigen incidence and the tumor incidence in inoculated RIIIf mice were somewhat elevated over controls. The question remains unanswered as to whether there is an active MuMTV in our colony of tumor-bearing BALB/c mice and, if there is, whether it is associated with B particles.

Animals↗
PubMed1979

Effect of parity regimen on the rate of occurrence of mammary tumors in A, C3H, and RIII mice.

The occurrence rates of mammary tumors as affected by breeding regimen (early in life, late, continuous, or not at all) in A, RIII, and C3H mice were observed. The response to the breeding regimen was different in each of the three strains. The C3H stock was affected least, although the tumor occurrence rate was slower in virgins. In both A and RIII, only one litter at puberty resulted in the tumors occurring over the greatest age range; and in RIII mice, the occurrence rate and the mean tumor age were similar to those of the virgins. Normal continuous breeding caused the earliest tumors in all three strains, although the RIII mice, breeding after 18 weeks of age also caused very early tumors. The response of RIII strain to parity variations was more like that of humans than was the response of either of the other strains. Removal of the milk-transmitted virus from these strains by foster-nursing resulted in vastly different mammary tumor occurrence rates, the quantitative changes being different in each mouse strain.

Animals↗
PubMed1979

Do homologous chromosomes differ? A preliminary investigation based on DNA measurements.

This paper is concerned with the problem of deciding whether measurements from homologous chromosomes differ. First, a general mathematical model is proposed for studying the distribution of chromosome measurements. Next, log-likelihood ratios are used to test for correlation between homolog pairs and for differences between homolog means and variances. The tests are applied to measurments on 1946 pairs of chromosomes from 10 normal individuals. Test results are interpreted taking into account the large number (2025 total tests) required by the study. Our results demonstrate that, at the current level of resolution, most homologs do not show differences in DNA content. However, there is some evidence that several homologs pairs differ by small amounts of DNA (less than 0.2% of the autosomal genome). Power studies indicate that sample sizes of 20 to 30 measurements are required to detect differences of this size.

Chromosomes, Human↗
PubMed1979

A template method for decomposing flow cytometry histograms of human chromosomes.

A new method for decomposing flow cytometry histograms of isolated human metaphase chromosomes is described and tested. The method is based on fitting a template, composed of the means of all chromosomes of a normal karyotype to the flow histogram. The utility of the method is demonstrated by application to flow measurements of chromosomes from a normal person and comparing the results with those obtained by conventional cytophotometry. The power of the method for detecting gross chromosomal abnormalities, such as trisomy 21, as well as more subtle variations such as a single translocation, is determined for simulated data.

Chromosome Aberrations↗
PubMed1978

Immunization of mice against murine mammary tumor virus infection and mammary tumor development.

Formalin-inactivated whole murine mammary tumor virus (MuMTV), VuMTV membranes, the acid-soluble component of MuMTV, and purified MuMTV glycoprotein with a molecular weight of 55,000 (gp55; also designated as gp52) were used as vaccines in an attempt to identify the MuMTV antigen(s) that can protect mice from exogenous MuMTV infection and subsequent tumor development. Formalin-inactivated whole MuMTV, MuMTV membranes, and purified MuMTV gp55 were effective immunogens, whereas the acid-soluble component of MuMTV (which consists mainly of MuMTV gp55) failed to protect mice from challenge with live virus. These results suggest that (a) MuMTV gp55 is the major immunizing antigen and (b) its native conformation must be maintained for it to be an effective vaccine.

Acids↗
PubMed1978

Observations on the question of horizontal transmission of mouse mammary tumor virus.

Antigen and tumor incidences in BALB/c and C57BL mice after living as weanlings for 5 weeks in cages with mouse mammary tumor virus-infected females were compared with control BALB/c and C57BL mice living in the same laboratory. All mice were bred continuously, and third-lactation milks were tested for mouse mammary tumor virus antigen by Ouchterlony microimmunodiffusion test. Mammary tumor incidences in the cagemates were not significantly different from those in the controls, although the antigen incidences were significantly greater. However, phosphate-buffered salt solution (0.02 M phosphate, pH 7.4; 0.15 M NaCl; and 0.1% bovine serum albumin) and sham-inoculated mice also had elevated antigen incidences. Repeat tests of milks at the fourth or fifth lactations indicated that more than 50% of those positive at the third became negative at later lactations.

Animals↗
PubMed1977

RNase H and RNA-directed DNA polymerase: associated enzymatic activities of murine mammary tumor virus.

The RNA-directed DNA polymerase of murine mammary tumor virus, a type B RNA tumor virus, was purified sequentially through DEAE-cellulose, phosphocellulose (step gradient), and phosphocellulose (linear salt gradient) chromatography followed by glycerol sedimentation centrifugation. During all stages of purification, coincident peaks of RNA-directed DNA polymerase activity, templated by polyribocytidylate-oligodeoxyguanidylate, and RNase H digestion of [3H]polyriboadenylate-polydeoxythymidylate were observed, and both enzymatic activities displayed a cation preference for magnesium. Under conditions that removed adventitiously associated nucleases, RNase H activity was found to co-purify with polymerase. The specificity of this nuclease was assayed with various prepared substrates, which indicated that the polymerase-associated RNase H activity was directed only against the RNA strand of an RNA-DNA hybrid. It is highly probable that RNase H (RNA-DNA hybrid: ribonucleotide-hydrolase, EC 3.1.4..34) and RNA-directed DNA polymerase of type B viruses are associated enzymatic activities analogous to those observed for avian and mammalian type C RNA tumor viruses.

Mammary Tumor Virus, Mouse↗
PubMed1977

The metabolism of the neuroleptic agent 1 (4'-fluorophenyl)-4-(cyclohexyl-1'-piperzinyl-4'-carboxylated)-butan-1-one hydrochloride in rats and man.

1. An oral dose the neuroleptic agent 1-(4'-fluorophenyl)-4-(cyclohexyl-1'-(14C)piperazinyl-4'-carboxylate)butan-1-one was mainly eliminated in the urine within 12 h by rats and man. During 5 days, 63-6% and 83-3% was eliminated in the urine of rats and man respectively. 2. Plasma concentrations in man related a maximum during 30 min to 1 h, representing 1-43 microgram equiv./ml. The proportion of unchanged drug in plasma decreased from 48% at 15 min to less than 10% after 1 h. 3. Seven major radioactive components were detected in the chloroform extract of basified rat urine and five major components in similar extracts of human urine. The major rat metabolites were isolated and identified by mass spectrometry as components resulting from mono- and dihydroxylation in the cyclohexane ring, reduction of the keto group to a secondary alcohol and hydrolysis and decarboxylation of the cyclohexylcarbamoyl group. The major metabolite in the rat urine extract was the dihydroxylated secondary alcohol derivative while the major human metabolite was the monohydroxylated secondary alcohol derivative. The metabolites were also partly eliminated as conjugates.

Administration, Oral↗
PubMed1977

Quantification by DNA-based cytophotometry of the 9q+/22q-chromosomal translocation associated with chronic myelogenous leukemia.

DNA-based cytophotometry was used to analyze metaphase chromosomes in four patients with chronic myelogenous leukemia. In three of these patients, both Philadelphia chromosome (Ph1)-positive and Ph1-negative cells were measured. On the basis of these three patients, the characteristic 9q+/22q- translocation of chronic myelogenous leukemia involves the net transfer of 0.325% of the autosomal genome; there is no evidence of net gain or loss of DNA (apart from duplication of the Ph1 chromosome in one patient), and no significant difference is found in the amount of DNA transferred in different patients. Significant differences are found among patients in the derived Chromosomes 9 and the Ph1 chromosomes and are ascribed to preexisting variations in the Ph1-negative cells of these patients. There is no evidence in these patients of any further cytogenetic lesion associated with chronic myelogenous leukemia.

Adolescent↗
PubMed1976

Satellite DNA and cytogenetic evolution. DNA quantity, satellite DNA and karyotypic variations in kangaroo rats (genus Dipodomys).

The genus Dipodomys (kangaroo rats) exhibits major interspecies variations in the proportions of highly reiterated satellite DNA sequences in the genome as well as in the chromosome number and the proportions of uni-armed and bi-armed chromosomes. For nearly all of the approximately 22 species of the genus and several subspecies, liver DNA was distributed in neutral CsCl buoyant density gradients into four fractions; principal DNA (1.698 g/ml), intermediate-density DNA (1.702 G/ML), MS satellite (1.707 g/ml) and HS (heavy satellites (1.713 g/ml). The total nuclear DNA content of diploid liver cells measured in eleven species by quantitative cytophotometry, ranged from 6.9 to 10.9 pg. These data were correlated with known features of the karotypes of individual species. The salient findings were: (1) that interspecies variations in diploid chromosome number cluster at 52-54, 60-64 and 70-72 (2) that high total nuclear DNA was associated with high chromosome number, and with relatively large amounts of satellite DNA (3) that a high ratio of HS satellites to intermediate-density DNA was generally correlated with a predominance of metacentric and submetacentric chromosomes (high fundamental number). The relationships of satellite DNA to karyotype structure reveal a new level of hierarchy in the genome that appears capable of exerting global control over environmental adaptation and the evolution of new species. This mechanism is consistent with recent hypotheses that changes in the macro-structure of the genome are more important than point mutations in facilitating the rapid phases of animal evolution.

Animals↗
PubMed1976

In vitro susceptibility of mink lung cells to the mouse mammary tumor virus.

Lung cells from mink embryos were infected in vitro with a purified mammary tumor virus isolated from RIII mouse milk. Specific virus antigen at the cell surface was detected by membrane immunofluorescence; B-type virions budding from the cell membrane were seen by electron microscopy. Nucleic acid hybridization confirmed replication and specificity of the virus produced.

Animals↗