Search Results - (Author, Cooperation:A. J. Clark)

2013-07-23

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Adolescent ; Animals ; Body Mass Index ; Body Weight/*genetics ; Carrier Proteins/*genetics ; Child ; Child, Preschool ; Energy Metabolism/genetics ; Female ; Gene Deletion ; Humans ; Male ; Mice ; Mice, Knockout ; Obesity/*genetics/metabolism ; Receptor Activity-Modifying Proteins/genetics/*metabolism ; Receptor, Melanocortin, Type 4/genetics/*metabolism ; Young Adult

2018-06-30

American Physical Society (APS)

0031-9007

1079-7114

Physics

Nuclear Physics

2018-03-24

American Physical Society (APS)

0556-2813

1089-490X

Physics

Electroweak Interaction, Symmetries

2018-03-24

American Physical Society (APS)

0556-2821

1089-4918

Physics

General relativity, alternative theories of gravity

2018-05-05

American Physical Society (APS)

0031-9007

1079-7114

Physics

Nuclear Physics

2018-11-15

American Physical Society (APS)

0556-2813

1089-490X

Physics

Nuclear Structure

1546-1696

Nature Archives 1869 - 2009

Biology

Process Engineering, Biotechnology, Nutrition Technology

[Auszug] Nuclear transfer offers a cell-based route for producing precise genetic modifications in a range of animal species. Using sheep, we report reproducible targeted gene deletion at two independent loci in fetal fibro-blasts. Vital regions were deleted from the α(1,3)galactosyl transferase ...

Electronic Resource

1546-1696

Nature Archives 1869 - 2009

Biology

Process Engineering, Biotechnology, Nutrition Technology

[Auszug] Transgenic livestock may prove useful for the large scale production of valuable proteins. By targeting expression to the mammary gland these proteins could be harvested from milk. To this end, we have designed a hybrid gene to direct the synthesis of human anti-hemophilic factor IX to the mammary ...

Electronic Resource

1432-1440

Key words ACTH receptor ; Adrenal failure ; Autosomal recessive diseases ; Signal transduction ; Proopiomelanocortin

Springer Online Journal Archives 1860-2000

Medicine

Abstract  Familial glucocorticoid deficiency is a rare autosomal recessive disease characterised by resistance to the action of ACTH. A number of mutations in the ACTH receptor have been demonstrated in patients with this disorder which are likely to lead to loss of receptor function and thus would account for the syndrome. Several patients, however, do not have mutations in the ACTH receptor gene coding region, and it can be demonstrated by segregation analysis that another distant gene must account for the disease in some of these cases. The nature of several candidate genes for this normal receptor form of the disease is discussed.

Electronic Resource

1546-1696

Nature Archives 1869 - 2009

Biology

Process Engineering, Biotechnology, Nutrition Technology

[Auszug] To test whether foreign gene expression can be improved in transgenic mice by manipulating the site of integration, we co-integrated the efficiently expressed sheep β-lactoglobulin gene with two poorly expressed β-lactoglobulin-derived genes encoding human proteins. In each case, we ...

Electronic Resource

1432-0428

Home glucose monitoring ; capillary tubes

Springer Online Journal Archives 1860-2000

Medicine

Summary A formal evaluation of the Sarstedt capillary tube system for blood glucose sampling was undertaken. Results obtained with the method were found to be highly reproducible (coefficient of variation = 4.7%) and accurate (mean±SD difference between this system and a reference system =-0.14±0.45 mmol/l). A decline in glucose values by 10% occurred when they were stored for 48 h before analysis, and this decline persisted in samples kept at room temperature, but was abolished by storage at 4 °C.

Electronic Resource

1420-9071

Gene transfer ; gene modification ; gene expression ; livestock ; transgenic animal ; pharmaceutical proteins ; milk composition

Springer Online Journal Archives 1860-2000

Biology

Medicine

Abstract There is every reason to expect that it will be possible within the next few years to begin to use farm animals to produce large quantities of some of the human proteins that are needed for the treatment of disease. Revolutionary new opportunities for the production of novel proteins in milk have been created by the development of methods for gene transfer. Exploitation of these opportunities depends upon selection and cloning of milk protein genes and identification of the sequences that govern tissue specific hormonally induced expression in the mammary gland. Studies with three genes, ovine β-lactoglobulin, rat β-casein and whey acidic protein of rat and mouse, suggest that they may all meet this requirement. Fragments of the ovine β-lactoglobulin, murine whey acidic protein and rabbit β-casein genes have directed production of novel proteins in the milk of transgenic mice, sheep, rabbits and pigs. The proteins were biologically active and usually co-migrated with authentic proteins. In early experiments, protein concentration was low, but our recent observations suggest that fusion genes containing genomic clones direct production of concentrations of protein that are suitable for commercial exploitation. In the longer term, two approaches may offer the potential of more reliable expression. Control elements capable of directing expression that is independent of site of insertion of the gene, but dependent on the number of copies of the gene, have been identified for a small number of genes. The availability of such elements for the milk protein genes would increase the reliability of gene expression considerably. Alternatively, targeted mutation of genes may allow the insertion of coding sequences within an existing gene so avoiding position effects.

Electronic Resource

1432-1106

Nucleus accumbens ; Electrolytic lesion ; PREE ; Locomotion

Springer Online Journal Archives 1860-2000

Medicine

Summary The partial reinforcement extinction effect (PREE) refers to the increased resistance to extinction observed in animals trained on a partial reinforcement (PR) schedule compared with those trained on a schedule of continuous reinforcement (CR). It has been suggested that the PREE is dependent upon the integrity of the septo-hippocampal system, but recent evidence has indicated that the role originally proposed for the lateral septal nucleus may in fact be subserved by the nucleus accumbens. Experiment I therefore tested the effects of electrolytic lesions of the nucleus accumbens on the PREE. These lesions abolished the PREE, the abolition resulting from a decreased rate of extinction in the lesion CR rats coupled with an increased rate of extinction in the PR rats. These results clearly implicate the nucleus accumbens in the development of the PREE, and suggest that theoretical models of the PREE based simply upon consideration of septohippocampal interactions need radical revision. The lesion also enhanced running speeds in acquisition in both the CR and the PR groups. Experiment II therefore assessed spontaneous locomotor activity and the locomotor response to amphetamine challenge at two doses. The lesion produced no increase in spontaneous locomotion; an enhanced increase in response to 1 mg/kg amphetamine; and no changes in the stereotyped behaviours induced by 10 mg/kg amphetamine.

Electronic Resource

1432-1211

Springer Online Journal Archives 1860-2000

Biology

Medicine

Electronic Resource

1432-2048

Key words:Colletotrichum ; Defense response (active) ; Phaseolus ; Gene expression ( pgip) ; Plant-pathogen interaction ; Polygalacturonase-inhibiting protein (gene expression)

Springer Online Journal Archives 1860-2000

Biology

Abstract. Expression of the polygalacturonase-inhibiting-protein gene ( pgip) during development of French bean (Phaseolus vulgaris L. cv. Red Kidney) was analysed in various organs, including leaves, stems and roots of etiolated and light-grown seedlings, light-grown adult plants, as well as flowers, pods, and seeds. In light-grown seedlings and plants, pgip transcripts were detected in all tissues examined, with higher levels found in the transition zone between the elongating and mature region of young hypocotyls, and in the basal region of the stem of adult plants. In etiolated hypocotyls, levels of pgip transcripts in the elongating region were five- to six fold higher than in light-grown hypocotyls. High levels of transcripts were also observed in pods. Accumulation of pgip mRNA was also followed in both compatible and incompatible race-cultivar interactions between Colletotrichum lindemuthianum races α and γ, respectively, and P. vulgaris by Northern blot analysis and in situ hybridisation. In situ experiments showed, in incompatible interactions, a rapid, intense and transient accumulation of pgip mRNA in epidermal cells proximal to the site of infection, and, less intense, within the cortical parenchyma underneath. In compatible interactions, no substantial accumulation of pgip mRNA was observed in hypocotyls; a very weak accumulation was observed in leaves during lesion formation.

Electronic Resource

1617-4623

Introns ; Mammary gland ; Ovine genome ; Splicing ; Transgenes

Springer Online Journal Archives 1860-2000

Biology

Abstract Eukaryotic pre-mRNAs undergo a variety of post-transcriptional modifications, including the removal of intronic sequences by splicing, leading to creation of a functional mRNA. We have compared the processing of transcripts generated from ovineβ-lactoglobulin gene constructs in stably transfected cells and in transgenic mice. In both the in vitro and in vivo model systems the removal of the middle two introns resulted in the inefficient splicing of the downstream, terminal intron. This intron-containing transcript was detected in the cytoplasmic RNA fraction. Thus, the initial in vitro analysis in cell lines of minigene constructs destined for expression in transgenic animals may provide a rapid and reliable indicator of the processing efficiency of the pre-mRNA produced by the construct in vivo. This is in contrast to the apparent limitations of in vitro systems in the analysis of transcription regulatory elements required for transgene expression.

Electronic Resource

1617-4623

Springer Online Journal Archives 1860-2000

Biology

Summary A double male strain ofE. coli K12 is capable of siring F′ progeny at a frequency approximately 103 to 105 times greater than that shown by normal Hfr strains. The F′ derivatives are merodiploid for approximately 30% of the standardE. coli map. The F′ element inherited by these progeny is called F20. Anomalies in the donor characteristics of the F′ progeny are explained by a description of the possible recombinant types in which markers heterozygous in the merodiploid strains are reassorted and by an analysis of the concept of the F′ strain. Characterization of the F′ progeny biochemically and morphologically is also discussed.

Electronic Resource

1573-2932

AOT40 ; assimilation rate ; autumn leaf discoloration ; biomass ; chlorophyll fluorescence ; critical level ; visible symptoms

Springer Online Journal Archives 1860-2000

Energy, Environment Protection, Nuclear Power Engineering

Abstract This investigation is intended to add to the quantitative information about the sensitivity of European deciduous tree species to environmentally realistic ozone (O3) exposure in respect to the established critical level of an AOT40 of 10 ppm.h (6-month growing season, daylight hours). Cuttings (without leaves) of Fagus sylvatica L., Sorbus aucuparia, L., Carpinus betulus L., Fraxinus excelsior L., and cuttings and seedlings of Prunus serotina Ehrh. were exposed during one growing season either to filtered air, to which 50 % of ambient O3 concentration was added, or to 50 % + 30 ppb O3, resulting in a final AOT40 of 0.3 and 20.7 ppm.h, respectively. The foliage formed per tree varied between and within the species, but was not significantly modified by O3, whereas the number of symptomatic leaves per tree significantly increased in the 50 % + 30 ppb O3 regime. By mid July light-green spots appeared in the leaves (except C. betulus), which developed into stippling (F. excelsior), red (P. serotina) or necrotic spots by September. The CO3-assimilation rate decreased more with increasing visual symptoms (earliest in 20- day-old leaves) than with age-dependent leaf discoloration in F. sylvatica, F. excelsior, and P. serotina (not in C. betulus). The dark-adapted photosystem II quantum yield (Fv/Fm) slightly declined with leaf age, but a considerable reduction became apparent in 107-day-old leaves with O3-symptoms only. By late morning yield reduction in light-adapted leaves were exaggerated in such leaves from the 50 % + 30 ppb O3 regime. The above mentioned responses were not reflected in significant changes of the net biomass production during the experiment. The critical level, therefore, is based on visual and functional symptoms rather than on production.

Electronic Resource

0044-8249

Chemistry ; General Chemistry

Wiley InterScience Backfile Collection 1832-2000

Chemistry and Pharmacology

Electronic Resource

0730-2312

milk/protein ; transgenic ; bovine ; dairy industry ; Life and Medical Sciences ; Cell & Developmental Biology

Wiley InterScience Backfile Collection 1832-2000

Biology

Chemistry and Pharmacology

Medicine

Milk and milk products comprise a substantial fraction of the protein intake of the industrialised West. The establishment of germline manipulation techniques in cows offers opportunities for directly manipulating milk composition to produce products with enhanced nutritional and processing properties. The major milk proteins are encoded by a small number of abundantly expressed single-copy genes and a number of possible manipulations are described. Milk proteins exhibit complex interactions with each other and with other constituents of milk. It will, therefore, be necessary to utilise model systems to evaluate the consequences of these proposed changes before embarking upon the costly and time-consuming process of manipulating the bovine genome.

2 Ill.

Electronic Resource