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B J Carter

Publications and source records attributed to B J Carter.

126 records · Page 7Linked to original sources
PubMed1976

Genome localization of adeno-associated virus RNA.

In previous work, linear duplex molecules of adeno-associated virus, type 2 (AAV2), DNA were cleaved with the restriction endonucleases R-EcoRI, R-HindII, and R-HindIII. The physical order of the specific fragments obtained was deduced and oriented with respect to the DNA strand polarity and the direction of transcription. Stable AAV RNA is transcribed only from 70% of the minus DNA strand. We report here RNA-DNA hybridization experiments using these restriction fragments to obtain a more accurate map of the portion of the AAV genome represented in stable RNA. The data obtained with several sets of restriction fragments annealed to either whole-cell RNA or poly(A)-containing RNA were internally consistent. The AAV RNA annealed with a continuous region of the AAV DNA, beginning at 0.18 map units (18%) from the left end of the molecule and ending at 0.88 map units. In addition, the restriction endonuclease BamHI was found to make one specific cleavage in AAV2 DNA at 0.22 map units, which is 0.04 map units (i.e., 160 nucleotides) to the right (""down stream'') of the point corresponding to the 5' end of the viral mRNA.

DNA Restriction Enzymes↗
PubMed1975

Physical map and strand polarity of specific fragments of adenovirus-associated virus DNA produced by endonuclease R-EcoRI.

Cleavage of adenovirus-associated virus type 2 (AAV2) DNA linear duplex monomers with the restriction endonuclease R-EcoRI yielded three fragments, A, B, and C, having approximate mol wt of 1.6 X 10(6), 1.1 X 10(6), and 1.3 X 10(5), respectively. Radioactive labeling the 5' termini of AAV DNA before cleavage with R-EcoRI showed that A and B were terminal fragments and C was internal. Separation of the complementary strands of fragments A and B showed that A contained the 5' terminus of the minus strand and the 3' terminus of the plus strand, and conversely for fragment B. The physical map of the AAV R-EcoRI fragments can thus be unambiguously determined and is drawn with B at the left-hand and A at the right-hand end. On this map, transcription of stable AAV mRNA from the minus strand proceeds from left to right, beginning in fragment B and terminating in fragment A. The asymmetry in distribution of thymidine between the AAV DNA plus and minus strands is preferentially located in fragment A, which represents the right-hand half of the duplex molecule. These experiments enable preparative separation of all four single-strand termini of AAV DNA and provide a basis for orientation of fragment maps derived by cleavage with other restriction enzymes.

DNA Restriction Enzymes↗
PubMed1974

Analysis of parvovirus mRNA by sedimentation and electrophoresis in aqueous and nonaqueous solution.

Adenovirus-associated virus (AAV)-specific RNA present in the cytoplasm of cells coinfected with a helper adenovirus was analyzed by sucrose gradient sedimentation and gel electrophoresis. In aqueous conditions both gels or gradients revealed three AAV RNA components corresponding to 30S, 27S, and 20S and having apparent molecular weights of 2.6 x 10(6), 1.75 x 10(6) to 1.8 x 10(6), and 0.9 x 10(6) to 1.0 x 10(6), respectively. In nonaqueous, denaturing solvents only the 20S AAV RNA species was observed. For this reason, and because they would be apparently significantly larger than a single AAV DNA strand, both the 30S and 27S species are believed to result from conformational or aggregation effects in the aqueous nondenaturing systems. It is concluded that only a single RNA molecule having a molecular weight of approximately 0.9 x 10(6) to 1.0 x 10(6) is synthesized by AAV.

Adenoviridae↗
PubMed1973

Self-complementarity of terminal sequences within plus or minus strands of adenovirus-associated virus DNA.

At least 70% of plus or minus strands of adenovirus-associated virus DNA contain self-complementary sequences at or near their termini. Self-annealing of these sequences generates circular molecules that are closed by duplex, hydrogen-bonded segments. The self-annealed segments are sensitive to exonuclease III and have a thermal stability comparable to that of double-stranded DNA molecules. Length measurements of double-stranded adenovirus-associated virus DNA molecules show a bimodal distribution, with the larger component being 10% shorter than SV40 DNA. The presence of self-complementary terminal sequences in single-stranded molecules of viral DNA has been observed previously only with DNA from adenoviruses. It is thus especially notable that adenovirus-associated virus replication is unconditionally dependent on a helper adenovirus. A possible role for terminal self-complementary sequences in viral DNA replication is suggested.

Adenoviridae↗
PubMed1972

Adenovirus-associated virus multiplication. 8. Analysis of in vivo transcription induced by complete or partial helper viruses.

We have analyzed ribonucleic acid (RNA) synthesized in KB cells co-infected with adenovirus-associated virus (AAV) type 2 and either adenovirus type 2 (Ad2) or herpes simplex virus type 1 (HSV-1). With either type of helper virus, synthesis of AAV RNA was readily detected by deoxyribonucleic acid (DNA)-RNA hybridization. As is the case for AAV RNA synthesized with helper Ad2, the AAV RNA synthesized with HSV-1 as helper annealed only to the thymidine-rich (minus) AAV DNA strand. In addition, AAV RNA synthesized with either type of helper (i) contained similar nucleotide sequences as determined by hybridization inhibition tests and (ii) had a mean molecular weight of approximately 7.5 x 10(5) based on sedimentation in dimethylsulfoxide-sucrose gradients. These experiments suggest that the restricted helper function of HSV-1 is not due to abnormal transcription of the AAV genome. Since the mean molecular weight of AAV RNA is equivalent to 40 to 50% of the AAV genome, as few as two or three AAV RNA species may be transcribed in vivo. In contrast to adenovirus RNA, cleavage of AAV RNA after transcription was not observed.

Adenoviridae↗
PubMed1972

Adenovirus-associated virus multiplication. IX. Extent of transcription of the viral genome in vivo.

Nucleic acid hybridization procedures were used to measure the extent of transcription of adenovirus-associated virus (AAV) deoxyribonucleic acid (DNA) in KB cells in the presence of either adenovirus or herpes simplex virus as the helper. Annealing of AAV ribonucleic acid to AAV DNA was monitored by a hybridization inhibition assay on nitrocellulose filters or by hydroxyapatite chromatography. These experiments confirmed the previous observation that, in the presence of either type of helper virus, only one strand of AAV DNA (the thymidine-rich or "minus" strand) is transcribed in vivo. However, it was found that only 70 to 80% of this strand appears to be transcribed in vivo. Furthermore, studies with minus strands employing hydroxyapatite chromatography and nuclease S(1), which specifically degrades single-stranded DNA, indicated that up to 20% of the minus strand is self-complementary. It seems likely that these self-complementary sequences account for the bulk of that portion of the minus strand (20 to 30%) which is not transcribed in vivo.

Adenoviridae↗
PubMedDate not supplied

Transforming growth factor type e is a novel mediator of wound repair.

Transforming growth factor type e is a potent mitogen for epithelial and fibroblastic cells in vitro. It is primarily produced by epithelial tissues and cells, including normal skin keratinocytes. In this study we examined the effects of transforming growth factor type e in vivo and in vitro. On application of transforming growth factor type e to the chorioallantoic membrane of 8-day-old chick embryos, we noted a prominent thickening of the membrane caused primarily by fibroblastic and epithelial proliferation. In a subsequent study, transforming growth factor type e suspended in Matrigel was injected subcutaneously into the abdominal wall of Swiss National Institutes of Health mice. Significant influx of first neutrophils and then macrophages into the gel of transforming growth factor type e-treated mice, but not of control mice, was observed. Transforming growth factor type e also exhibited a potent chemoattractive effect on the J774 macrophage cell line in vitro. In transcutaneous mouse wounds, topical administration of transforming growth factor type e led first to an influx of neutrophils and macrophages, followed by an increased formation of granulation tissue in the transforming growth factor type e-treated wounds. These results suggest that transforming growth factor type e plays an important role in wound healing as a chemoattractant for neutrophils and macrophages and as a mitogen for epithelial and fibroblastic cells.

Journal Article↗
PubMedDate not supplied

Surviving breast cancer: a problematic work re-entry.

This article presents a paradigm case of a problematic work re-entry experience of a breast cancer survivor (Kathy). The case was drawn from a qualitative descriptive study of 25 long-term survivors of breast cancer. The study describes the lived experience and practical "know how" of survivors. Study participants completed three in-depth process interviews that were transcribed and analyzed for common themes. The paradigm case presented here is one of five paradigms that emerged from the data. The case demonstrates the profound impact of a negative work re-entry experience on a cancer survivor's reformulating sense of self. In addition to pericarditis and lymphedema, Kathy experienced long-term emotional distress. Although work provided a primary source of meaning, Kathy ultimately gave up her desire to return to work. Predominant features of the case include: a breach of confidentiality of medical information in the work setting; absence of resources and support to assist with work re-entry and the management of social stigma; difficulty in talking with colleagues and others about her health; and difficulty in asking for and receiving assistance. The understandings set forth from Kathy's experience can guide clinicians to explore the meaning of work in the lives of their patients and can encourage the development and use of work re-entry programs.

Adaptation, Psychological↗