Biomedical subjects

R Hooley

Publications and source records attributed to R Hooley.

22 records · Page 2Linked to original sources

PubMed1990

Gibberellin perception in the Avena fatua aleurone.

Gibberellins (GAs) are a class of plant hormones involved in the regulation of plant growth and development. A useful model system for studying GA-action is the aleurone layer of cereal grain. In aleurone, GA induces a considerable increase in the rates of transcription of alpha-amylase genes, and this effect can be inhibited by another plant hormone abscisic acid. We anticipate that perception of GA by aleurone cells involves an interaction between the ligand and specific receptors and that this event leads to the observed stimulation in transcription of alpha-amylase, and probably other, aleurone genes. Hormone binding assays with aleurone have not revealed a candidate receptor, and the only aspect of signal transduction that is becoming understood is the likely interaction between specific trans-acting factors and cis-elements in the GA-regulation of alpha-amylase gene transcription. This paper describes the development of novel ways for identifying GA-receptors in aleurone protoplasts of Avena fatua that are based on the use of affinity and antibody probes in functional in vivo assays for GA-receptors. The implications of our current findings are discussed in relation to models of GA-action in aleurone.

Edible Grain↗

PubMed1986

Hormonal Regulation of alpha-Amylase Gene Transcription in Wild Oat (Avena fatua L.) Aleurone Protoplasts.

The time of appearance and relative amounts of alpha-amylase mRNA in wild oat (Avena fatua L.) aleurone protoplasts incubated with 1 micromolar gibberellin A(4) (GA(4)) were closely correlated with the amounts of alpha-amylase enzyme secreted by the protoplasts. In the absence of GA(4), or when protoplasts were incubated with 25 micromolar abscisic acid (ABA) together with 1 micromolar GA(4) no alpha-amylase mRNA was detected and only very low levels of alpha-amylase were secreted. Nuclei were isolated in high yields (65-71%) from aleurone protoplasts and in an in vitro transcription system displayed characteristics of a faithful DNA-dependent RNA synthesizing system. The time course of incorporation of [(3)H]-UTP suggested that the RNA synthesized was mainly ;run off' transcription and therefore that the transcripts produced in vitro were those being synthesized in the protoplasts at the times when the nuclei were isolated. By hybridizing in vitro synthesized [(32)P]RNA to barley alpha-amylase cDNA and control filters we have estimated that 90 +/- 10 ppm of the transcripts synthesized by nuclei isolated from GA(4) treated protoplasts can be attributed to alpha-amylase sequences and that statistically insignificant amounts of these transcripts are obtained from control and GA(4) plus ABA treatments. The results suggest that GA(4) and ABA influence the transcription of alpha-amylase genes in aleurone protoplasts of wild oat.

Journal Article↗

PubMed1983

The role of intravenous hyperalimentation in intestinal disease.

This article has dealt briefly with intravenous nutrition in intestinal disorders. The indications for its use and techniques of nutritional assessment have been stressed. The use of intravenous hyperalimentation in a few of the more common diseases of the small bowel and colon has been discussed. Every patient with disease of the small or large intestine has some degree of dysfunction in the gastrointestinal tract. In many instances, this functional impairment interferes with normal ingestion or absorption of nutrients and predisposes the patient to malnutrition. The presence of malnutrition increases the morbidity and mortality of surgery and can be reversed by using intravenous hyperalimentation. Those patients with extreme short bowel syndrome secondary to intestinal disease or its parenteral nutrition at home. We stress the importance of a team approach to hyperalimentation. The evolution of a team of nutritional experts will improve the care of the patient and the education of the patient and physician and make nutritional support more readily available to those medical and surgical patients in need.

Anthropometry↗

PubMed1980

Home parenteral nutrition for the short bowel syndrome. Psychological issues.

Home parenteral nutrition (HPN) for the short bowel syndrome represents a treatment modality that raises issues about prolonged machine dependency for living. Psychological reactions are described for patients with inflammatory bowel disorders and anatomical loss of small bowel. Liaison psychiatry involvement with 50 patients in the HPN program has identified such problems as grief reactions, depression, organic brain syndromes, drug dependency, and body image changes as they influence the initial adjustment to the in-hospital phase of HPN learning for patient and family. The importance of family and mental status examination are emphasized in the evaluation of the patient before and during the institution of an PHN program. Outlined are psychological parameters that need to be considered when assessing what factors might impede or enhance the acquisition and use of HPN information.

Adult↗