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Biomedical subjects

J Paul

Publications and source records attributed to J Paul.

At least 235 records · Page 13Linked to original sources
PubMed1982

A B1 repetitive sequence near the mouse beta-major globin gene.

A sequence which lies 2.8 kb to the 3' side of the BALB/c mouse beta-major globin gene has been identified by its ability to hybridise to a member of the human Alu repetitive sequence family. Nucleotide sequencing revealed a 133-bp region that shows 89% homology to the consensus sequence of the B1 family, the murine equivalent of the Alu family. To the 3' side of this sequence is a 31-bp region, C(A)3(C)2T(C)3G(C)11(A)9, which contains oligo(C) and oligo(A) tracts. The whole 164-bp sequence is flanked by a 16-bp imperfect direct repeat, G(A)4GGAGTCTCATAG. The orientation of the B1 sequence is such that transcription by RNA polymerase III would be expected to occur in the same direction as transcription of the neighbouring beta-major globin gene by RNA polymerase II.

Animals↗
PubMed1982

Effects of chloramphenicol on the development of immune responses to canine distemper virus in beagle pups.

The effect of oral chloramphenicol (CHPC) on the development of immune responses to canine distemper virus (CDV) in Beagle pups was studied. Dogs were treated with CHPC for 14 days at a dose of 50 mg/kg, three times a day. Hematologic changes in CHPC-treated dogs included: polychromasia, anisocytosis, and target cell formation of red blood cells concurrent with vacuolation of lymphocytes and basophilic granule formation in neutrophils. Dogs given this therapy showed normal in vivo and in vitro immune responses after CDV vaccination and survived a virulent CDV challenge, whereas untreated, unvaccinated dogs became ill or died after challenge exposure. The results of this study indicate that CHPC therapy does not interfere with either the prechallenge immune response to attenuated viral antigen or the efficient immune mechanisms invoked during virulent virus challenge.

Animals↗
PubMed1981

Biological and mechanical behavior of autologous pericardium used for tricuspid valvular replacement in dogs.

The fate of autologous pericardium when used to replace a tricuspid valve leaflet has been investigated in dogs. Changes have been studied by means of macroscopic, mechanical, histological, scanning electron microscopy, and in vitro culture techniques. In each of nine experiments the valve failed and death occurred within the first 15 post-operative days. Retraction, thickening of the cusp, fibrinous deposition and/or tissue rupture were associated with a decrease of resistance to traction tests, decrease of elasticity and increase of viscosity of the implanted tissue. The early behavior of autologous pericardium was characterized by precocious inflammatory reaction on the valve leaflets, focal disruption of the collagenous structure of the leaflets, absence of fibroblastic cell infiltration as confirmed by in vitro culture of implanted pericardium and the lack of endothelial-like cell surface at the 10th-15th postoperative day.

Animals↗
PubMed1981

Characterization of Alu family repetitive sequences which flank human beta-type globin genes.

Heteroduplex mapping has determined the size, location, and orientation of three Alu family sequences from the human beta-type globin gene cluster. Two of these sequences have the same orientation. One (231 bp long) is 2 kb to the 5' side of the B gamma-globin gene and the other (222 bp) is l kb 5' to the pseudo-beta-l-globin gene. The third (300 bp), 3-4 kb 3' to the pseudo-beta-l-globin gene, has the opposite orientation. Their orientations relative to five previously characterized Alu sequences from this cluster have been established. One of these, 2.5 kb 5' to the epsilon-globin gene, was shown by Southern blot hybridization to be similar but not identical to other family members, whereas the region separating it from a neighbouring inverted repeat is not widely distributed in the human genome.

Base Sequence↗
PubMed1981

Transfer and expression of herpes simplex virus thymidine kinase and human globin genes in mammalian cells studied by spot hybridization assays.

A spot hybridization assay has been developed for rapid estimations of specific DNA sequences in whole mammalian cells or DNA. This method is applicable to gene-transfer studies in determining the copy number(s) of foreign DNA(s) introduced into mammalian cells. A similar assay has been developed for determining amounts of specific RNA sequences in mammalian cells. It is also shown that this method is applicable to gene-transfer studies and in particular to determining the expression of foreign genes introduced into cells.

Animals↗
PubMed1981

DNA binding proteins in chromatin structure and function.

The binding of chromosomal proteins to cloned mouse and human globin genes can be determined by transferring proteins from one dimensional electrophoretic separations on to nitrocellulose paper and exposing them to nick translated cloned globin DNAs. The usefulness of this technique is assessed in the case of RNA polymerases isolated from mouse Ascites tumor cells where a specific initiation site for transcription of mouse beta globin DNA can be demonstrated.

Animals↗
PubMed1981

Cell-cycle dependence of induced hemoglobin synthesis in Friend erythroleukemia cells temperature-sensitive for growth.

Friend erythroleukemia cells temperature-sensitive (ts) for growth have been used to study the cell-cycle dependence of erythroid differentiation. ts cells accumulated hemoglobin in response to inducer when replicating optimally at permissive temperatures. However, when arrested in the G1 phase of the cell cycle at a nonpermissive temperature, ts cells did not accumulate hemoglobin or globin mRNA nor did they differentiate terminally. Under these conditions, the viability of ts cells treated with inducer at the nonpermissive temperature remained high (70% of that of cells induced at the permissive temperature) as judged by cloning experiments. Total RNA and protein synthesis of G1 cells treated with inducer was 44-48% of that of randomly proliferating induced cells, in contrast to thymidine incorporation into DNA which decreased to 2% of that of cells replicating at the permissive temperature. Furthermore, G1 ts cells treated with inducer accumulated hemoglobin when released from growth arrest at the permissive temperature in the presence (but not in the absence) of inducer. These results are consistent with a requirement for a cell cycle-dependent event prior to commitment to differentiation.

Animals↗
PubMed1981

In vivo release of a heparin-like factor in dogs during profound hypothermia.

Experimentally induced hypothermia (20 degrees C) for 60 minutes in dogs provokes a significant decrease in the platelet count, which reverses during subsequent rewarming, and the constant release of a heparin-like factor, which reacts as a specific inhibitor of factor Xa. This phenomenon is also rapidly reversible, and heparin values are not significantly different from control levels after 90 minutes of rewarming. The mean maximal concentration of heparin-like material is 0.54 U/ml, or about double control levels. Its half-life is approximately 90 minutes. The level of circulating antithrombin III was not modified during hypothermia and rewarming.

Animals↗
PubMed1980

Repetitive DNA sequences near three human beta-type globin genes.

Five repetitive DNA sequences, of average length 259 bp, have been identified in the intergenic regions which flank three human beta-tupe globin genes. A pair of inverted repeat sequences, separated by 919 bp, was found 1.0 kb to the 5' side of the epsiln-globin gene. Each contains a homologous Alu I site. Another repetitive sequence, with the same orientation as the inverted repeat sequence closest to the epsilon-globin gene, lies about 2.2 kb to the 5' side of the delta-globin gene. A pair of inverted repeat sequences, with the same relative orientations as the other pair and separated by about 800 bp, was found about 1.5 kb to the 3' side of the beta-globin gene.

Base Sequence↗
PubMed1980

Transcription of Friend virus proviral sequences in isolated nuclei.

Transcription studies using isolated Friend nuclei and Escherichia coli polymerase are presented. Combination of the techniques of thiol-Sepharose chromatography and cDNA-Sepharose hybridisation has resulted in a system in which the transcription of the Friend virus proviral sequences with endogenous and E. coli polymerase can be examined. The results show that the percentage of Friend viral-specific sequences in RNA transcribed by E. coli RNA polymerase and by endogenous RNA polymerase in isolated nuclei are similar. The percentage of viral-specific sequences synthesized in isolated nuclei is similar to that found in Friend cell nuclear RNA.

Animals↗