Relationship between multidrug resistance,hypersensitivity to resistance modifiers and cell volume in Chinese hamster ovary cells.

We have previously shown that very high levels of hypersensitivity to several resistance modifiers are correlated with increasing multidrug resistance in a series of Chinese hamster ovary cell lines. We have now selected a new member of the series which is an exception to this correlation in that although it is almost twice as multidrug resistant as the cell line from which it was derived, it shows much less hypersensitivity to resistance modifiers. Level of resistance modifier hypersensitivity correlated with the level of reduction of verapamil accumulation in these cells, and with the density of P-glycoprotein, but since the selection of this cell line has involved a doubling of cell volume, it was not correlated with total amount of P-glycoprotein.     

Are all data types and connectivity models created equal? Validating common connectivity approaches with dispersal data

Aim

There is enormous interest in applying connectivity modelling to resistance surfaces for identifying corridors for conservation action. However, the multiple analytical approaches used to estimate resistance surfaces and predict connectivity across resistance surfaces have not been rigorously compared, and it is unclear what methods provide the best inferences about population connectivity. Using a large empirical data set on puma (Puma concolor), we are the first to compare several of the most common approaches for estimating resistance and modelling connectivity and validate them with dispersal data.

Location

Southern California, USA.

Methods

We estimate resistance using presence‐only data, GPS telemetry data from puma home ranges and genetic data using a variety of analytical methods. We model connectivity with cost distance and circuit theory algorithms. We then measure the ability of each data type and connectivity algorithm to capture GPS telemetry points of dispersing pumas.

Results

We found that resource selection functions based on GPS telemetry points and paths outperformed species distribution models when applied using cost distance connectivity algorithms. Point and path selection functions were not statistically different in their performance, but point selection functions were more sensitive to the transformation used to convert relative probability of use to resistance. Point and path selection functions and landscape genetics outperformed other methods when applied with cost distance; no methods outperformed one another with circuit theory.

Main conclusions

We conclude that path or point selection functions, or landscape genetic models, should be used to estimate landscape resistance for wildlife. In cases where resource limitations prohibit the collection of GPS collar or genetic data, our results suggest that species distribution models, while weaker, may still be sufficient for resistance estimation. We recommend the use of cost distance‐based approaches, such as least‐cost corridors and resistant kernels, for estimating connectivity and identifying functional corridors for terrestrial wildlife.

     

The development of patient information leaflets. Care of the mouth after radiotherapy

Objectives: Describe the methodology used to produce a patient leaflet on care of the mouth after radiotherapy. Design: Prospective study to design a patient information leaflet. Setting and Subjects : Patients undergoing radiotherapy for oral cancer. Intervention: After a review of the relevant literature, a patient questionnaire was produced. This was then completed by patients undergoing radiotherapy treatment and gave an indication of the problems being encountered. Healthcare professionals were surveyed for their views. A leaflet was then produced according to published guidelines. It was taken back to another group of patients and a further version produced after input from a health promotion group. Results: A leaflet was produced after wide consultation and survey. Conclusion: Considerable effort must to be put into the production of patient information leaflet. It must be discussed with patients in the target group if it is to be sensitive, understood and find acceptance among its users     

Isolation and molecular identification of planctomycete bacteria from postlarvae of the giant tiger prawn, Penaeus monodon.

Bacteria phenotypically resembling members of the phylogenetically distinct planctomycete group of the domain Bacteria were isolated from postlarvae of the giant tiger prawn, Penaeus monodon. A selective medium designed in the light of planctomycete antibiotic resistance characteristics was used for this isolation. Planctomycetes were isolated from both healthy and monodon baculovirus-infected prawn postlarvae. The predominant colony type recovered from postlarvae regardless of viral infection status was nonpigmented. Other, less commonly observed types were pink or orange pigmented. A planctomycete-specific 16S rRNA-directed probe was designed and used to screen the isolates for their identity as planctomycetes prior to molecular phylogenetic characterization. 16S rRNA genes from nine prawn isolates together with two planctomycete reference strains (Planctomyces brasiliensis and Gemmata obscuriglobus) were sequenced and compared with reference sequences from the planctomycetes and other members of the domain Bacteria. Phylogenetic analyses and sequence signatures of the 16S rRNA genes demonstrated that the prawn isolates were members of the planctomycete group. Five representatives of the predominant nonpigmented colony type were members of the Pirellula group within the planctomycetes, as were three pink-pigmented colony type representatives. Homology values and tree topology indicated that representatives of the nonpigmented and pink-pigmented colony types formed two discrete clusters within the Pirellula group, not identical to any known Pirellula species. A sole representative of the orange colony type was a member of the Planctomyces group, virtually identical in 16S rDNA sequence to P. brasiliensis, and exhibited distinctive morphology.     

Control of woolly aphid, Eriosoma lanigerum (Hausmann) (Hemiptera: Pemphigidae) on mature apple trees using insecticide soil-root drenches

Abstract Woolly aphid, Eriosoma lanigerum , is an important pest of apples that infests both the aerial and root parts of the tree. Root colonies are protected from the pesticide sprays applied during the growing season and the climatic effects of winter. Consequently, root colonies are a major source of aerial re-infestation in the following spring. Imidacloprid, the first of a new group of insecticides from the chloronicotinyl family, is known to provide excellent control of woolly aphid on trees up to 7-years-old when applied as a root soil drench. This study compared the effects of a single application of chlorpyrifos, imidacloprid, pirimicarb or vamidothion, applied as a root drench over four growing seasons. A soil wetting agent was added to each chemical to improve soil saturation and penetration. Imidacloprid provided excellent control of woolly aphid on the trees that were 17-years-old at the start of the study and continued to do so for four seasons. Pirimicarb appeared to offer some suppression of woolly aphid during the first season but not in subsequent seasons, while chlorpyrifos and vamidothion failed to control woolly aphid in any season. The potential role for imidacloprid in IPM programs is discussed.     

A rapid technique for the analytical and preparative isolation of transfer RNA from reaction mixtures

The isolation of enzymically modified tRNA's from enzyme reaction mixtures is usually achieved by one of two general methods. Amino-acyl synthetase reactions are easily assayed by filter paper techniques (1) in which the tRNA is precipitated on filters of materials such as cellulose ester or glass fiber. After drying, the filters can be counted by several techniques. The limitations of this technique include unknown counting efficiency and loss of the sample. In cases in which recovery of the tRNA is desired the usual procedure involves phenol extraction of the tRNA followed by selective precipitation with salts and/or organic solvents.     

Membrane Attachment of R-Factor Deoxyribonucleic Acid in Compatible and Incompatible Cell Pairs Following Conjugation

Superinfection of an Escherichia coli R(+) strain with a closely related R-factor was associated with the accumulation of replicative intermediates of the superinfecting deoxyribonucleic acid. This deoxyribonucleic acid remains associated with a rapidly sedimenting cell component.