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A Gough

Publications and source records attributed to A Gough.

71 records · Page 4Linked to original sources
PubMed1989

Chromosome mapping of the human gene encoding the 68-kDa nuclear antigen (p68) by using the polymerase chain reaction.

Chromosome mapping by Southern analysis of DNA from somatic cell hybrids is often unsuccessful when only cDNA probes are available. p68 is a putative RNA helicase that is antigenically related to the simian virus 40 large tumor antigen. By using the polymerase chain reaction and oligode-oxynucleotide primers based on the cDNA sequence, we have identified introns in the p68 gene. Comparison of human and mouse DNA fragments amplified with these primers revealed length differences that allowed us to identify the human gene. Application of this technique to DNA from human-mouse somatic cell hybrids and cell lines derived from them by chromosome-mediated gene transfer allowed us to map p68 to the distal part of the long arm of chromosome 17.

Amino Acid Sequence↗
PubMed1988

Analysis of rhodamine and fluorescein-labeled F-actin diffusion in vitro by fluorescence photobleaching recovery.

Properties of filamentous acetamidofluorescein-labeled actin and acetamidotetramethylrhodamine-labeled actin (AF and ATR-actin, respectively) were examined to resolve discrepancies in the reported translational diffusion coefficients of F-actin measured in vitro by FPR and other techniques. Using falling-ball viscometry and two independent versions of fluorescence photobleaching recovery (FPR), the present data indicate that several factors are responsible for these discrepancies. Gel filtration chromatography profoundly affects the viscosity of actin solutions and filament diffusion coefficients. ATR-actin and, to a lesser degree, AF-actin show a reduction in viscosity in proportion to the fraction labeled, presumably due to filament shortening. Actin filaments containing AF-actin or ATR-actin are susceptible to photoinduced damage, including a covalent cross-linking of actin protomers within filaments and an apparent cleavage of filaments detected by a decrease of the measured viscosity and an increase in the measured filament diffusion coefficients. Quantum yields of the two photoinduced effects are quite different. Multiple cross-links are produced relative to each photobleaching event, whereas less than 1% filament cleavage occurs. Substantial differences in the filament diffusion coefficients measured by FPR are also the result of differences in illumination geometry and sampling time. However, under controlled conditions, FPR can be used as a quantitative tool for measuring the hydrodynamic properties of actin filaments. Incremented filament shortening caused by photoinduced cleavage or incremental addition of filament capping proteins produces a continuous and approximately linear increase of filament diffusion coefficients, indicating that filaments are not associated in solution. Our results indicate that actin filaments exhibit low mobilities and it is inferred that actin filaments formed in vitro by column-purified actin, under standard conditions, are much longer than has conventionally been presumed.

Actins↗
PubMed1982

Role of the bilayer in the shape of the isolated erythrocyte membrane.

The determinants of cell shape were explored in a study of the crenation (spiculation) of the isolated erythrocyte membrane. Standard ghosts prepared in 5 mM NaPi (pH 8) were plump, dimpled disks even when prepared from echinocytic (spiculated) red cells. These ghosts became crenated in the presence of isotonic saline, millimolar levels of divalent cations, 1 mM 2,4-dinitrophenol or 0.1 mM lysolecithin. Crenation was suppressed in ghosts generated under conditions of minimal osmotic stress, in ghosts from red cells partially depleted of cholesterol, and, paradoxically, in ghosts from red cells crenated by lysolecithin. The susceptibility of ghosts to crenation was lost with time; this process was potentiated by elevated temperature, low ionic strength, and traces of detergents or chlorpromazine. In that ghost shape was influenced by a variety of amphipaths, our results favor the premise that the bilayer and not the subjacent protein reticulum drives ghost crenation. The data also suggest that vigorous osmotic hemolysis induces a redistribution of lipids between the two leaflets of the bilayer which affects membrane contour through a bilayer couple mechanism. Subsequent relaxation of that metastable distribution could account for the observed loss of crenatability.

Chlorpromazine↗
PubMed1980

Relationship between amino acid dose and gastric secretory response.

Gastric secretory dose-response studies, using an 8.5% mixed L-amino acid solution as the agonist, were carried out in three dogs with Heidenhain pouches and gastric fistulae. Secretory responses of the Heidenhain pouches were measured during two hour infusions of amino acids given at rates of 0, 0.05, 0.1, 0.2, 0.4, 0.8, and 1.6 g/kg/h and plasma amino nitrogen was measured before and during the infusion. Three separate studies at each dose level were made in each dog. The maximum secretory response occurred at the dose of 0.4 g/kg/h and amounted to approximately 20% of the maximal histamine response. Larger doses produced no additional increase in secretion or an actual decrease in secretory rate. It is concluded that the solution of amino acids used acts as a modest gastric agonist and that increases in plasma amino nitrogen such as may be observed after a protein meal are capable of eliciting a slight, but definite, gastric secretory response.

Amino Acids↗
PubMed1978

Radiological evaluation of the cardiac apex in Jamaican children.

The position of the clinical apex beat projected on chest radiographs was compared to different points on the cardiac outline which have been regarded as the radiological apex. Good correlation was found between the clinical apex and the most lateral point of the left cardiac border, but not with the cardiophrenic angle or the lower end of the long diameter of the heart. The mid-clavicular line cannot be used to define the upper limit of the normal sized heart on radiographs as in clinical practice, because in many of the subjects the heart extended outside the mid-clavicular line.

Child↗
PubMed1978

Position of the apex beat in childhood.

The position of the apex beat in relation to the midclavicular and nipples lines and the intercostal spaces was studied in 353 healthy Jamaican children from birth to 10 years. The traditional use of the midclavicular line as a reference point in relation to the apex beat is not an accurate index of normal heart size at all ages. For this purpose actual measurement of the apex beat, which ranges between 2.8 and and 5.4 cm from the midline, should be made. However, for a rough estimate of normal cardiac size the midclavicular line may be used. In contrast, the nipple line lies outside the apex beat at all ages; it should not be used in the clinical evaluation of normal cardiac size. From birth to age 3 years the apex beat is located in the 4th intercostal space and with increasing age gradually moves into the 5th space in most children.

Anthropometry↗
PubMedDate not supplied

New treatments in ulcer healing and wound infection.

This review examines several of the recently introduced wound care products that have been put forward as treatment modalities for the diabetic foot ulcer. Discussed are the results of clinical trials with the platelet-derived growth factor, becaplermin, the tissue-engineered products Dermagraft and Apligraf, and Hyaff which is an ester of hyaluronic acid. In patients with an infected foot ulcer, encouraging results were obtained with the granulocyte-colony stimulating factor, Filgrastim.

Becaplermin↗
PubMedDate not supplied

HLA-DR4 and career prospects in rheumatology: is there a link?

OBJECTIVE: To determine whether HLA type is associated with career progress in rheumatology. DESIGN: Comparison of HLA type after HLA analysis of samples of venous blood. SETTING: Department of Rheumatology Research, University of Birmingham. SUBJECTS: All (37) staff in the department. RESULTS: All the senior academics and most staff with a PhD expressed HLA-DR4. The prevalence of expression in each of these groups was significantly greater than that found in the controls. None of the junior doctors or secretaries expressed DR4. CONCLUSION: The junior doctors in the department have poor career prospects as HLA-DR4 seems to be associated with academic achievement.

Career Choice↗