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Biomedical subjects

H Manor

Publications and source records attributed to H Manor.

At least 55 records · Page 3Linked to original sources
PubMed1987

Diagnosis of varicocele and postoperative evaluation using inguinal ultrasonography.

Ultrasonographic real-time imaging and measurements of spermatic veins in the inguinal canal were evaluated in two groups of patients: 20 young men with varicocele and 18 controls. Examinations were performed with the patient in an upright relaxed position, and performing the Valsalva maneuver. The increase in diameter of the main vein during Valsalva maneuver was considered to quantitatively represent venous reflux. The data obtained were correlated with pre- and postoperative clinical findings. This method of evaluation proved to be a useful noninvasive diagnostic modality for detecting varicocele and for assessing treatment results. On the basis of venous diameters and reflux values, a classification of varicocele is proposed. Such an objective method of grading would eliminate the subjective impression and interpretation factors of the examiner.

Adolescent↗
PubMed1987

Unusual sequence element found at the end of an amplicon.

In a polyomavirus-transformed rat cell line, designated LPT, the polyomavirus DNA is integrated into a single chromosomal site. Treatment of LPT cells with carcinogens induces amplification of the integrated virus DNA and flanking cellular sequences. We show that the amplification is arrested within a specific cell DNA segment that maps 1.3 to 1.85 kilobases beyond one virus-cell DNA junction, defined as the left junction. We also present the sequence of an 897-base-pair fragment spanning the arrest site. This fragment contains an unusual sequence element, which consists of two contiguous components, a potential cruciform with stems of 6 base pairs and a d(G-A)27 X d(T-C)27 tract, and maps 1,497 to 1,564 nucleotides beyond the left junction. The possibility that this unusual sequence plays a role in the arrest of the amplification process is discussed.

Animals↗
PubMed1985

Patterns of methylation of polyomavirus DNA in polyoma-transformed rat cells.

The patterns of methylation of integrated polyomavirus (Py) DNA and flanking cellular sequences were determined in an inducible line of Py-transformed rat cells, designated LPT, by an analysis of cleavage patterns of LPT DNA generated by the restriction enzymes MspI, HpaII, and HhaI. The Py DNA in LPT cells is integrated into a single chromosomal site and includes whole viral genomes arranged in a head-to-tail configuration. Amplification of the viral DNA and synthesis of infectious virus can be induced in these cells by treatment with carcinogens. The experiments reported here show that in uninduced LPT cells only the late Py genes, which encode the Py capsid proteins, and sequences flanking one of the two viral DNA-cell DNA junctions are methylated. The early genes, encoding the Py T antigens, and sequences flanking the second junction are unmethylated. Since only the early genes are transcribed and translated in uninduced LPT cells, it is apparent that an inverse correlation exists between transcription and methylation of the integrated Py genes in LPT cells, as reported in other cellular and viral systems. The patterns of methylation of integrated Py genomes were also examined in cells of a subclonal derivative of the LPT line in which the virus cannot be activated. In these cells, not only the late Py genes were found to be methylated, but also the 3' portion of the early gene which encodes the Py large T antigen. These findings may have implications for understanding Py induction in LPT cells.

Animals↗
PubMed1985

Solitary eosinophilic granuloma of sternum: case report with review of the literature.

A solitary lesion in the distal sternum in a 30-year-old woman caused by eosinophilic granuloma (EG) is reported. Bone scan with 99Tcm was negative. Laboratory tests were completely normal. Although EG bone lesions have been discussed extensively in the literature only one similar case of solitary EG of the sternum has been published to date. A comprehensive summary of the literature is presented.

Adult↗
PubMed1985

Accessory urethral channel.

A case of accessory urethral channel with wide divergence of the pubes, suggesting a relationship to the exstrophy-epispadias complex, is described. The various embryogenic factors and possible modes of treatment are discussed.

Adolescent↗
PubMed1984

Mapping of polyadenylated transcripts of a monkey lymphotropic papova virus.

Polyadenylated transcripts of a monkey lymphotropic papovavirus (LPV), which can be propagated in monkey and human lymphoblastoid cell lines, were identified and mapped. Polyadenylated RNA was purified from cells of the human line BJA/B infected with LPV, and was hybridized with various LPV DNA fragments. The hybrids were treated with S1 endonuclease and analyzed by alkaline gel electrophoresis. This analysis revealed two groups of RNA molecules encoded in two regions of the LPV genome. One group includes four colinear transcripts of 2.3, 2.1, 1.85, and 1.2 kb, whose polyadenylated termini map at a single site on the LPV DNA. The second group includes two less-abundant transcripts of 1.8 and 1.95 kb. The polarities of the LPV transcripts were determined by hybridizing cDNA complementary to their 3' termini with LPV DNA fragments. The two groups were found to have opposite polarities. It is shown that the four major transcripts can be aligned with, and may be functionally related to, SV40 and polyoma virus "late" mRNAs. It is also inferred that the 1.8- and 1.95-kb RNA species may be functionally related to the "early" transcripts of these papovaviruses.

Animals↗
PubMed1983

"Onion skin" replication of integrated polyoma virus DNA and flanking sequences in polyoma-transformed rat cells: termination within a specific cellular DNA segment.

Replication of integrated polyoma virus DNA and flanking cellular sequences was studied in an inducible line of polyoma-transformed rat cells, designated the LPT line, that contains a single viral integration site. Chromosomal DNAs were purified from LPT cells treated with the virus-inducing agent mitomycin C and from untreated cells and were digested with restriction enzymes. The digests were analyzed by the Southern blotting technique. The virus DNA and a recombinant plasmid containing flanking cell DNA were used as hybridization probes. The analysis showed that mitomycin C treatment caused a more than 10-fold amplification of restriction fragments extending up to about 2.0 kilobase pairs into the cellular DNA flanking one end of the viral insertions, defined as the left joint. Fragments extending beyond this region were not amplified. These results showed that (i) integrated polyoma virus DNA undergoes multiple rounds of replication in mitomycin C-treated LPT cells and (ii) the replication extends into the flanking sequences and is arrested within a 0.40-kilobase-pair cellular DNA segment located about 2.0 kilobase pairs beyond the left joint. This segment may include a terminator of a normal cellular replicon.

Cell Line↗
PubMed1983

Integration of polyoma virus DNA into chromosomal DNA in transformed rat cells causes deletion of flanking cell sequences.

In order to find out whether polyoma virus (Py) integration into chromosomes causes rearrangements in the cell DNA flanking the integration site, we have mapped the flanking sequences in the inducible LPT line of Py-transformed rat cells and the corresponding sequences in normal rat fibroblasts, and then compared the two maps. To carry out this study we have cloned a segment including Py DNA and flanking sequences in the bacteriophage vector lambda gt WES and subcloned the flanking cell DNA in a bacterial plasmid. We performed a Southern blot analysis of LPT and rat fibroblast DNA digested with various restriction enzymes and used the cloned flanking cell DNA and Py DNA as hybridization probes. Autoradiography of the LPT DNA blots revealed two sets of fragments. One set includes fragments containing both Py and cell DNA sequences; the second set consists of fragments which contain no virus DNA sequences, and are identical to the fragments observed in the corresponding normal rat DNA digests. These data indicate that LPT cells are heterozygous with respect to the Py inserts. The same data were used to map the flanking sequences in the two types of cells. A comparison between the two maps revealed that a 3.0 kb cell DNA segment, which is located next to the unoccupied integration site in the normal rat chromosomes, has been deleted from the LPT chromosome which carries Py DNA, but not from the LPT chromosome which does not carry the virus DNA. The implications for papovavirus integration are discussed.

Animals↗
PubMed1982

Integration site of polyoma virus DNA in the inducible LPT line of polyoma-transformed rat cells.

The structure of the polyoma virus (Py) integration site in the inducible LPT line of Py-transformed rat cells was determined by biochemical methods of gene mapping. LPT cell DNA was digested with various restriction enzymes. The digestion products were electrophoresed in agarose gels and transferred onto nitrocellulose sheets by Southern blotting. Fragments containing viral or cell DNA sequences, or both, were identified by hybridization with Py DNA or with a cloned flanking cell DNA probe. Cleavage of LPT DNA with enzymes that restrict the Py genome once generated linear Py DNA molecules and two fragments containing both cell and viral DNA sequences. Cleavage of LPT DNA with enzymes which do not restrict Py DNA generated series of fragments whose lengths were found to differ by increments of a whole Py genome; the smallest fragment in each series was found to be longer than the viral genome. These data indicate that LPT cultures contain Py insertions of various lengths integrated into the same chromosomal site in all the cells. The length heterogeneity of the viral insertions is due to the presence of 0, 1, 2, 3. . . Py genomes arranged in a direct tandem repeat within invariable sequences of viral DNA. Double-digestion experiments were also carried out with the above enzymes and with enzymes that cleave the Py genome at multiple sites. The data obtained in these experiments were used to construct a physical map of the integration site. This map showed that the early region of the virus remained intact even in the smallest insertion (which contains no whole duplicated genomes), whereas the late region was partially duplicated and split during integration. The smallest insertion is colinear with the Py physical map over a region including the entire Py genome and at least a part of the duplicated segment. This structure could give rise to nondefective circular viral DNA molecules by single homologous recombination events. Similar recombination events may occur at a higher frequency in the longer insertions, which include longer regions of homology, and may yield many more free viral genomes. The presence of these insertions in LPT cells could thus be one of the factors which account for the high inducibility of the LPT line.

Animals↗
PubMed1980

Electron microscopic demonstration of the presence of amplified sequences at the 5'-ends of the polyoma virus late mRNAs.

Electron microscopic techniques were used to examine the structure of the leader sequences at the 5'-ends of the late polyoma virus mRNAs. The three late mRNA's were partially purified and hybridized to an E. coli plasmid containing two polyoma virus genomes inserted in tandem. The hybrids were spread by the cytochrome c-formamide technique and visualized in the electron microscope. These studies revealed that whereas the body of a given mRNA molecule can hybridize with only one of the two corresponding body sequences in the two adjacent viral genomes, the leader of the same mRNA molecule can hybridize with both copies of the leader sequence-specific DNA. The mVP1 and mVP3 RNA species thus generated hybrids containing two loops, while mVP2 molecules formed hybrids containing one loop. Hence, the leaders of the three polyoma virus late mRNA species must contain two or more repeats of a sequence transcribed from a unique DNA segment. Length measurements showed that most leaders in the late mRNA's consist of at least 200 nucleotides and some contain up to 500 nucleotides, whereas the basic repeat sequence contains about 60 nucleotides.

Base Sequence↗
PubMed1979

Electron microscopic mapping of RNA transcribed from the late region of polyoma virus DNA.

The polyoma virus (Py) RNA species transcribed from the L DNA strand of the "late" region of the Py genome in Py-infected mouse cells have been mapped by hybridization with specific fragments of Py DNA followed by electron microscopic visualization of the hybrids. Total cellular polyadenylated Py-specific RNA molecules having an S value in the range of 16S to 20S were purified by oligodeoxythymidylic acidcellulose column chromatography, preparative hybridization with Py DNA, and sucrose gradient centrifugation. Cytoplasmic Py-specific RNA was similarily purified, except that it was not fractionated by sucrose gradient centrifugation. Hybrids of these RNA molecules and Py DNA fragments were spread for electron microscopy by either the cytochrome c technique or the bacteriophage T4 gene 32 protein method. The polyadenylic acid at the 3'-end of the RNA in the hybrids was identified by labeling with simian virus 40 DNA circles to which polybromodeoxyuridylic acid tails had been covalently attached. These experiments revealed the presence of three L DNA strand transcripts in both RNA preparations. Two of these RNA molecules were found to be spliced from chains transcribed from two noncontiguous parts of the late region. The third molecule either is a continuous transcript of the entire late region or contains a splicing feature which is too small to be reliably observed by the electron microscope methods used. The 5'-ends of the three RNA species map within a region extending from 68 to 70 map units on the Py restriction endonuclease map. Each of the two spliced molecules contains a 5'-terminal leader sequence transcribed from a DNA segment with an estimated length of 60 to 110 nuvleotides. The 3'-ends of the leaders map at 66.7 +/- 1.0 and 66.4 +/- 0.50 map units. In these molecules the 5'-ends of the other part (the main body) map at 59.4 +/- 0.90 and 49.4 +/- 2.0 map units, respectively. The 3'-termini of all three RNA species map at 24 to 25 map units.

DNA, Viral↗
PubMed1979

Secondary structures in polyoma DNA.

Three reproducible secondary-structure features were observed on single strands of polyoma virus DNA mounted for electron microscopy by the T4 gene 32 protein technique: (i) a hairpin fold-back extending from 92.9 +/- 0.8 to 95.0 +/- 0.7 map units; (ii) a small loop extending from 63.2 +/- 3.1 to 68.5 +/- 2.8 map units; and (iii) a big loop extending from 51.9 +/- 2.3 to 68.9 +/- 2.1 map units. Both loops are bounded by inverted repeat stems of length 40 +/- 20 base pairs. The stem sequences around 68.5 and 68.9 of the large and small loops overlap, either partially or completely. Several lines of evidence indicate that the inverted repeat stems of the two secondary-structure loops lie in the regions of polyoma virus DNA flanking and probably very close to the sequences that are spliced out in the formation of the late 16S and 18S messages, whereas the hairpin fold-back appears to map at a splicing point of an early message. These structures may therefore be important for the processing of the primary transcripts to form the early and late messages.

DNA Restriction Enzymes↗
PubMed1978

Polyoma virus-specific RNA synthesis in an inducible line of polyoma virus-transformed rat cells.

Viral RNA present in the inducible LPT clone 1A of polyoma virus-transformed rat cells was characterized before and after mitomycin C induction by hybridization with 32P-labeled separated E and L strands of polyoma viral DNA restriction endonuclease fragments. In clone 1A cells maintained under normal growth conditions, the cytoplasm contained a transcript of the E-strand DNA from the "early" region similar to that previously identified in lytically infected cells, as well as minor quantities of RNA complementary to less than one-half of the L- and the E-strand DNA from the "late" region. Nuclei of normally growing cells contained the same species found in the cytoplasm, as well as an additional abundant RNA complementary to one-half of the L-strand DNA of the late region. No significant changes occurred in the cytoplasmic viral RNA after mitomycin C treatment before the onset of viral DNA replication, but the concentration of the nuclear L-strand DNA transcript diminished. After the onset of viral DNA replication after mitomycin C treatment, transcripts of virtually the entire L-strand DNA were found in the nuclei, and a 10-fold increase was observed in the abundance of RNA transcribed from the E strand of the early region. In the cytoplasm, the abundance of the early RNA increased about 25-fold and late RNA complementary to the L-strand DNA of the late region was found in a similar quantity. The synthesis of both the early and the late RNA species was inhibited if viral DNA replication was blocked with 5-fluorodeoxyuridine. We conclude that the induction of viral DNA replication in LPT cells is not determined at the level of mRNA synthesis.

Animals↗