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Biomedical subjects

J D Martin

Publications and source records attributed to J D Martin.

At least 73 records · Page 4Linked to original sources
PubMed1983

The effect of estrogen receptor status on survival in patients with endometrial cancer.

This study demonstrates a significantly increased survival time for women with estrogen receptor-positive adenocarcinoma of the endometrium when compared with that of those with estrogen receptor-negative tumors (p less than 0.05). This prognostic factor provides information which is additional to, and independent of, that provided by the histologic grade and myometrial penetration of the tumor.

Adenocarcinoma↗
PubMed1983

Characterization of tissue culture-induced heterogeneity in DNAs of independent isolates of JC virus.

After several serial passages at low multiplicities of infection in primary human foetal glial cells at 37 degrees C, the DNA of prototype (MAD-1) JC virus and that of MAD-2 and MAD-3 are typically heterogeneous in size, but DNAs of MAD-4 and MAD-6 are relatively homogeneous. A similar dichotomy was observed in the DNAs of six isolates propagated more recently in glial cultures at 39 degrees C under similar conditions of brief passage in vitro at low multiplicities of infection: the DNAs of two (MAD-9 and -10) were heterogeneous, but the DNAs of four others (MAD-8, -11, -12 and -14) were homogeneous. Therefore, the propensity of the viral genome to sustain deletions was an intrinsic property of each isolate. However, actual induction and maintenance of the presumably defective DNAs was influenced by the relative proportions of permissive spongioblasts and semi-permissive astrocytes in the glial cultures and by the multiplicity of infection. Deletions in MAD-1 DNA were confined to the presumptive early region and spanned the BamHI cleavage site (map position 0.505). The heterogeneity was more complex in the DNAs of MAD-2 and MAD-3, but again most of the deletions, which ranged up to 12% of full-length DNA, spanned the BamHI site. We propose that the differential susceptibility to deletion among isolates is a consequence of natural genetic variation in JC virus.

Chromosome Deletion↗
PubMed1983

Relationship of hostility and white space responses on the Rorschach.

The present study was conducted to assess the relationship between hostility and white space responses on the Rorschach. The Rorschach was administered individually to 80 volunteer students on the university campus. 71 subjects were undergraduates and 9 were graduates. The mean age for the group was 24 yr. Among the males, 19 were white and 4 were non-white; among the females, 49 were white and 8 were non-white. Level of hostility was determined by Elizur's scoring of content and by adding all the weights for each subject's protocol. Percent was obtained for each subject by dividing the total of such responses by R or total number of responses. A significant correlation of .20 was obtained between level of hostility and white space responses. A correlation of .46 between total responses and white space responses was also significant. Gender and level of hostility correlated -.33. A multiple regression analysis gave an r of .51 for the combination of gender and total responses and level of hostility.

Adult↗
PubMed1983

Intercorrelations among white space responses on Rorschach, ego strength, conformity, and self-esteem.

The present study was undertaken to determine the magnitude of relationship between the white space responses (S) on the Rorschach and ego strength, as determined by Barron's Ego Strength Scale. Correlations between the white space response (S) and conformity, as measured by the conformity scale of the Jackson Personality Inventory, and S and self-esteem, as measured by the self-esteem scale of the Jackson Personality Inventory, were also investigated. For 44 female and 12 male undergraduates the correlation between white space responses and ego strength was non-significant, as were correlations between white space responses and ego strength, conformity, and self-esteem. Intercorrelations among ego strength, conformity, and self-esteem were significant. Also, white space responses (S) and the total number of responses (R) were significantly correlated.

Adolescent↗
PubMed1983

Naturally occurring and passage-induced variation in the genome of JC virus.

We have examined both the naturally occurring and passage-induced variation in the genome of the human polyomavirus, JCV. JCV DNA was extracted directly from diseased brain tissue of ten cases of progressive multifocal leukoencephalopathy (PML) and the DNA population from any one case was homogeneous with respect to length and restriction endonuclease cleavage patterns. However, a comparison of cloned JCV DNAs revealed that the viral DNAs derived from different cases of PML were not identical. We identified a hypervariable region near the origin of DNA replication, and we demonstrated that there are two genetically distinguishable subtypes of the virus. After growth in vitro, the DNA from certain isolates of JCV became heterogeneous in size. Deletions of up to 12% of the genome occurred after as few a three low multiplicity passages in human glial cells. Most of the deletions mapped within the region presumed to code for T antigen. In addition, we examined the physical properties of JCV from brain and, as expected, they were typical of the polyomavirus genus.

Brain↗
PubMed1982

Is progressive multifocal leukoencephalopathy a chronic disease because of defective interfering particles or temperature-sensitive mutants of JC virus?

JC virus was examined for temperature sensitivity and for evidence of defective interfering particles as a means of explaining the slow chronic nature of progressive multifocal leukoencephalopathy (PML). JC virus direct from the brain tissue of seven persons with PML was not temperature sensitive as indicated by in vitro assay at 37 and 39 degrees C. In fact, more cells contained viral antigen at 39 than at 37 degrees C. The amount of infectious virus also was increased at 39 degrees C. Virions isolated directly from diseased brain tissue had a higher buoyant density than did virus from the same PML patient passaged in culture and containing genomic deletions. In contrast to DNA from culture-passed virus, DNA extracted from virions direct from brain tissue was homogeneous in length. In 13 separate cases examined, the viral DNA direct from the brain was homogeneous although variations in length were noted among DNAs from different cases. Restriction enzyme cleavage patterns identified all as JC virus DNA. It was concluded that neither temperature sensitivity nor DI particles can be used to explain the slow, progressive nature of PML.

Adult↗
PubMed1980

Integration pattern of human JC virus sequences in two clones of a cell line established from a JC virus-induced hamster brain tumor.

The physical state of the JC virus (JCV) genome was studied in two clonal cell lines (clones 2 and 7) derived from a tissue culture cell line (HJC-15) established from a hamster brain tumor induced by JCV. Saturation-hybridization and reassociation kinetic analyses, using in vitro (32)P-labeled JCV DNA, indicated that clone 7 and 2 cells contain 9 to 10 and 4 to 5 copies per cell, respectively, of all or most of the viral genome. Both cell DNAs were analyzed by using the Southern blotting procedure with three restriction endonucleases: XhoI, which does not cleave JCV DNA; EcoRI, which cleaves once; and HindIII, which cleaves three times. With each DNA, a variety of JCV-specific DNA fragments were detected. The following conclusions are possible: (i) JCV DNA is integrated into cell DNA in both clonal lines; (ii) both clonal lines contain multiple copies of the viral genome integrated in a tandem head-to-tail orientation; (iii) neither clonal line contains detectable free-form I, II, or III JCV DNA; (iv) each clonal line contains multiple independent sites of JCV DNA integration; and (v) most or all of the sites of integration on the cellular or the viral genome, or both, are different in clone 7 DNA than in clone 2 DNA. Thus, although both clone 7 and clone 2 cells were established from the HJC-15 tumor cell line, they differ in the copy number and integration pattern of JCV DNA.

Animals↗
PubMed1979

The effect of ribonuclease on the replicative forms of Sindbis virus RNA.

Three species of double-stranded RNA, designated RF I, RF II, and RF III in order of decreasing size (25), are produced by ribonuclease treatment of extracts of chicken embryo cells infected for 6 hours with Sindbis virus. Only one class of replicative form RNA is present in extracts not treated with ribonuclease; this class contains some molecules which can be enzymatically cleaved to produce the other two replicative forms. At a low level of enzyme (0.001 microgram/ml) the major species obtained was RF I, the replicative form of the genome. When the enzyme concentration was increased 10-, 100-, and 1000-fold, there was a progressive increase in the proportions of RF's II and III and a concomitant decrease in the proportion of RF I. The generation of RF's II and III by nuclease resulted in the ratio expected for these two species if they are produced by cleavage of RF I-like molecules. In preparations of isolated double-stranded RNA, only RF I and replicative intermediate RNA were present. Mild nuclease treatment of these preparations converted the replicative intermediates primarily to RF I. Higher enzyme levels generated greater proportions of RF II and RF III, but RF I-like molecules were the major source for these increased proportions. Treatment of the isolated naturally occurring replicative form with 0.01 microgram of ribonuclease per ml cleaved some molecules migrating as RF I during gel electrophoresis into molecules which migrated as RF II and RF III.

Animals↗
PubMed1979

Restriction endonuclease cleavage map of the DNA of JC virus.

A physical map of the sites cleaved by the following restriction endonucleases was derived for the DNA of JC virus, a human polyomavirus: EcoRI, HpaI, and PstI (one site each); HindII (four sites); and HindIII (three sites). By agarose gel electrophoresis of fragmented DNA, the size of full-length DNA of JC virus was estimated to be 5,125 +/- 105 base pairs (98 +/- 2% of the length of simian virus 40 DNA).

DNA Restriction Enzymes↗
PubMed1979

Infectivity of the DNA from four isolates of JC virus.

The infectivity of JC virus DNA was demonstrated in its most permissive cell culture, primary human fetal glial cells. The amount of infectivity observed in these heterogeneous cultures varied considerably between batches of cells. Contrary to results obtained with the papovaviruses simian virus 40 and BK virus, the calcium technique (F. L. Graham and A. J. van der Eb, Virology 52:456--467, 1973) was found to be more efficient at promoting JC virus DNA infectivity than the DEAE-dextran method (J. H. McCutchan and J. S. Pagano, J. Natl. Cancer Inst. 41:351--357, 1968): maximum infectivity titers of 4 x 10-(4) and 6 x 10(3) fluorescent cell units per microgram of DNA, respectively. These values represent an approximate recovery of infectivity from virus of between 0.02 and 0.14%. Comparisons of infectivity of DNAs obtained from four isolates of JC virus and which differed in their degrees of heterogeneity did not reveal significant differences. The JC virus DNA was not infectious in primary human fetal lung and kidney cells.

Antigens, Viral↗
PubMed1978

Oestrogen receptor studies in carcinoma of the endometrium, carcinoma of the uterine cervix and other gynaecological malignancies.

The tissues from 30 cases of endometrial cancer and 44 cases of cervical cancer were examined for oestrogen receptor activity. Twenty of the endometrial and 9 of the cervical tumours contained oestrogen receptor levels above 4 fmol/mg protein. The proportion of oestrogen receptor-positive tumours was significantly greater in adenocarcinomas of the cervix than in squamous carcinomas of the cervix. Tissues from 3 mixed mesodermal tumours of the uterus, 2 carcinomas of the vagina, a carcinoma in situ of the cervix and a carcinoma in situ of the endometrium were receptor-negative. One ovarian carcinoma and a single case of uterine sarcoma were receptor-positive. The implications of these findings in relation to hormonal therapies are discussed.

Adenocarcinoma↗