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Biomedical subjects

D Lane

Publications and source records attributed to D Lane.

At least 109 records · Page 6Linked to original sources
PubMed1985

Analysis of a region in plasmid R386 containing two functional replicons.

A miniplasmid has been obtained from R386 by ligating EcoRI fragments with a fragment carrying a kanamycin-resistance gene. It contains a 6.8-kb Eco fragment of R386 which hybridizes strongly with several IncFI plasmid DNAs but not with the primary or secondary replicons of the F plasmid. This mini-R386 is incompatible with certain IncFI plasmids, and it appears to be one example of a previously unidentified replicon widely distributed in the IncFI group. A region of R386 not closely linked to the 6.8-kb fragment is involved in copy number control of the mini-R386, and a sequence in the same region interacts with mini-F partition functions to cause incompatibility. The 6.8-kb fragment also restricts growth of T7 bacteriophage, and an adjacent fragment restricts phage T4 growth. A further R386 sequence, sharing homology with the F secondary replicon, is capable of autonomous replication. Hence R386, like F, contains at least two functional replicons.

Cell Division↗
PubMed1985

Location of rep and inc sequences in the F secondary replicon.

Miniplasmids derived by deletion of DNA from the F plasmid secondary replicon have been tested for the ability to replicate and to express incompatibility with the IncFI plasmid, ColV3-K30. The results demonstrate that the minimal rep region of the secondary replicon lies within a 1.9-kb sequence (33.7F-35.6F kb), and that an inc region, presumably involved in replication control, is present in a 0.45-kb portion of the rep region (33.7F-34.15F kb). In addition, the secondary replicon was found not to require DNA polymerase I activity.

Chromosome Mapping↗
PubMed1985

Forecasting demand for long-term care services.

This article analyzes three methods used to forecast the transition of long-term care clients through a variety of possible home and facility placements and levels of care. The test population (N = 1,653) is derived from the larger population of clients admitted in 1978 to British Columbia's newly established Long-Term Care program. The investigators have accumulated 5 years of service-generated data on moves, discharges, and deaths of these clients. Results show that the first-order Markov chain with stationary transition probabilities yields a superior forecast to state-by-state moving average growth and state-by-state regression analyses. The results of these analyses indicate that the Markov method should receive serious consideration as a tool for resource planning and allocation in long-term care.

Aged↗
PubMed1984

The mini-F primary origin. Sequence analysis and multiple activities.

The sequence of an 897 base-pair fragment (42.1 to 43.0 kilobase co-ordinates on the F genetic map) containing the primary origin (ori-1) of mini-F replication has been determined. It contains one significant open reading frame, which probably codes for part of the C protein thought to be necessary for ori-1 replication activity. Tests of the ability of the sequenced ori-1 region to direct replication of DNA polymerase I-dependent replicons revealed that ori-1 replication requires adjacent mini-F sequences, 43.0 to 43.9 kilobase co-ordinates on the F genetic map in cis as well as a trans-acting gene product, probably the E protein, from the essential replication region of mini-F. In addition, a sequence required for control of pif gene expression has been mapped to a 160 base-pair region immediately upstream from the C (pifC) gene, and the crossover site of a specific recA-independent recombination mechanism has been mapped to a 220 base-pair region on the side of the pif control sequence distal to the C gene.

Base Sequence↗
PubMed1983

A cryptic plasmid from Shigella sonnei.

pNZ500 is a 1.5 kb cryptic plasmid from a Shigella sonnei isolate. It was introduced into Escherichia coli by cotransformation, where it is maintained at about 30 copies per chromosome equivalent. Hybridization studies show that pNZ500 exhibits a high level of sequence similarity to other 1.5 kb plasmids found in different S. sonnei isolates but shares no homology with larger S. sonnei plasmids. pNZ500 shares a small degree of sequence homology with pBR322 and with pAC184. The homology with pBR322 is restricted to sequences close to the ori-bom region of this plasmid. Nevertheless, pNZ500 maintenance in E. coli is not dependent on DNA polymerase I activity, and does depend on continuing protein synthesis. pNZ500 encodes two polypeptide gene products whose monomer molecular weights are 24500 and 18000. The examination of host cells for the expression of possible plasmid phenotypes revealed no differences between cells bearing pNZ500 and plasmidless cells.

Bacterial Proteins↗
PubMed1982

Cellular proteins reactive with monoclonal antibodies directed against simian virus 40 T-antigen.

Several recently isolated monoclonal antibodies which reacted with simian virus 40 T antigens also reacted with proteins found in uninfected and untransformed cells. The proteins were different from each other, PAb419 reacting with a 35,000-molecular-weight protein, PAb427 reacting with a 75,000-molecular-weight phosphoprotein, PAb405 reacting with a 150,000-molecular-weight phosphoprotein, and PAb204 reacting with a 68,000-molecular-weight protein. It is suggested that although some of these cross-reactions may be fortuitous, they may, as an alternative, reflect similarities of shape and perhaps function between domains of the viral T antigen and the relevant host proteins.

Animals↗
PubMed1980

Characteristics of an SV40-plasmid recombinant and its movement into and out of the genome of a murine cell.

A bacterial plasmid carrying the early region of SV40 (pOT) has been stably established in high molecular weight (hmw) DNA of mouse L cells by selection for the herpes virus thymidine kinase (tk) gene. DNA blotting has demonstrated that most cell lines contain multiple discrete copies of pOT, generally with an intact SV40 early region. No free copies of pOT have been detected. Both pOT and tk sequences may be amplified up to 20-200 copies of the SV40 early region. In contrast to the uniform staining pattern normally observed in SV40-transformed lines, indirect immunofluorescence using antiserum to the SV40 T antigen has demonstrated that the expression of the early region is heterogeneous in these cell lines. This fraction expressing T is characteristic of a given cell line, and varies from 0 to 99% positive. Several pOT cell lines have been fused to simian cells, and replicating low molecular weight DNAs were isolated from the heterokaryons. Transformation of E. coli with this DNA demonstrates that pOT can be rescued from hmw DNA in L cells and reestablished as a plasmid in E. coli. Excision is generally precise when pOT is introduced to the murine cells as supercoiled molecule, and imprecise when pOT is introduced in linear form.

Animals↗
PubMed1980

Acute pneumonia and pneumothorax as a complication of transbronchial biopsy.

This report describes the development of an acute pneumonia and a pneumothorax after transbronchial biopsy with a fiberoptic bronchoscope. The patient was elderly and had a chronic bronchopneumonia. The literature is reviewed and it is concluded that elderly patients with chronic pyogenic pulmonary infections may represent a high risk category for this investigation.

Acute Disease↗