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A Whittaker

Publications and source records attributed to A Whittaker.

29 records · Page 2Linked to original sources
PubMed1996

Qualitative methods in general practice research: experience from the Oceanpoint Study.

BACKGROUND: The Oceanpoint Study is a collaborative study between general practice and medical anthropology. METHODS: The study involved a qualitative ethnographic approach including long-term participant observation, in-depth interviews, health diaries and focus group discussions. Qualitative methods are suited to describing the phenomenological perspectives of people through the generation of rich detailed accounts which leave participants' perspectives intact. RESULTS: The use of these methods in this study has enabled the researchers to explore a range of community beliefs and practices concerning health and illness. The underlying concerns and approach of general practice medicine are similar to those of the qualitative research tradition. CONCLUSIONS: The experience of being a general practitioner parallels the experience of an ethnographer conducting qualitative research and the paper explores the similarities and differences between them and discusses the usefulness of such collaborative research.

Adult↗
PubMed1994

Structure and orientation of the pore-forming peptide, melittin, in lipid bilayers.

Ten analogues of the 26-residue, bee venom peptide, melittin (H3N(+)-GIGAVLKVLTTGLPALISWIKRKRQQ-CONH2), were synthesized, each with 13C enrichment of a single peptide carbonyl carbon. These peptides were incorporated into bilayers of the diether lipid, ditetradecylphosphatidylcholine, aligned between stacked glass plates. Solid-state 13C nuclear magnetic resonance spectra were obtained as a function of the angle between the bilayer planes and the magnetic field of the spectrometers, and at temperatures above and below the lipid gel-to-liquid crystalline transition temperature, Tc. For bilayers aligned with the normal along the applied magnetic field there was no shift in the carbonyl resonances of residues Ile2, Ala4, Leu9, Leu13, or Ala15, with minor changes for residues Val8 and Ile20, and small changes at Val5, Leu6 and Ile17 on immobilization of the peptide below Tc. In contrast, the spectra for bilayers aligned at right angles to the field showed greatly increased anisotropy below Tc for all analogues. From these experiments it was evident that the peptide was well-aligned in the bilayers and reoriented about the bilayer normal. The observed reduced chemical shift anisotropies and the chemical shifts were consistent with melittin adopting a helical conformation with a transbilayer orientation in the lipid membranes. With the exception of Ile17, there was no apparent difference between the behaviour of residues in the two segments that form separate helices in the water-soluble form of the peptide, suggesting that in membranes the angle between the helices is greater than the 120 degrees observed in the crystal form.

Amino Acid Sequence↗
PubMed1994

Bradykinin B2- and 5-hydroxytryptamine (5-HT2)-receptor stimulated increases in intracellular calcium in cultured guinea-pig aortic smooth muscle cells.

The effect of 5-hydroxytryptamine (5-HT) and bradykinin on intracellular free calcium concentration ([Ca2+]i) has been studied in cultured guinea-pig aortic smooth muscle cells loaded with the Ca(2+)-sensitive fluorescent dye fura-2. Bradykinin and 5-HT elicited rapid increases in [Ca2+]i with log EC50 values of -7.9 +/- 0.05 M (N = 3) and -6.1 +/- 0.1 M (N = 4), respectively. Both agonists stimulated the release of intracellular calcium (Ca2+ responses still present in the absence of extracellular calcium) and to a lesser extent Ca2+ influx (observed when extracellular calcium was re-applied to cells initially stimulated in nominally Ca(2+)-free buffer containing 0.1 mM EGTA). The B1-receptor antagonist des-Arg9,[Leu8]-bradykinin had no effect on calcium responses elicited 100 nM bradykinin, whereas the B2-receptor antagonist D-Arg[Hyp3,Thi5.8,D-Phe7]-bradykinin (10 microM) inhibited the response to 100 nM bradykinin by 43%. The bradykinin B2-receptor antagonist D-Arg[Hyp3,Thi5.8,D-Phe7]-bradykinin virtually abolished the response to 10 nM bradykinin (IC50 4 microM). No increase in [Ca2+]i was observed with the B1-receptor agonist des-Arg9-bradykinin (300 nM). The response to 5-HT (100 microM) was abolished by the 5-HT2 receptor antagonist ketanserin (IC50 = 2 +/- 0.4 nM; N = 3). These data suggest that in cultured guinea-pig aortic smooth muscle cells bradykinin B2- and 5-HT2-receptor activation stimulates the release of Ca2+ from intracellular stores and Ca2+ influx through Ca2+ entry pathways in the plasma membrane.

Animals↗
PubMed1993

Isolation of mutations affecting neural circuitry required for grooming behavior in Drosophila melanogaster.

We have developed a screen for the isolation of mutations that produce neural defects in adult Drosophila melanogaster. In this screen, we identify mutants as flies unable to remove a light coating of applied dust in a 2-hr period. We have recovered and characterized six mutations and have found that they produce coordination defects and some have reduced levels of reflex responsiveness to the stimulation of single tactile sensory bristles. The grooming defects produced by all six of the mutations are recessive, and each of the mutations has been genetically mapped. We have also used our assay to test the grooming ability of stocks containing mutations that produce known neural defects.

Animals↗
PubMed1992

Erythropoietin use in the critical care setting.

Biotechnology products signify a major advancement in our world today. Products resulting from biotechnology will revolutionize how health care is delivered. One of these technologic breakthroughs is recombinant human erythropoietin (epoetin). Its impact on the delivery of care to the anemic renal patient is changing the roles of nurses who provide care for these patients. Epoetin alfa has virtually eliminated the necessity of transfusions in the renal patient population, while simultaneously improving the quality of life for those patients and their families. To appropriately monitor the patient receiving epoetin therapy, the nurse must understand iron physiology and metabolism, factors that influence blood pressure, and factors that can blunt the response to epoetin therapy, and still appreciate the individual nursing requirements of each patient. Such juggling of information demands that the critical care nurse be alert to the subtle changes occurring within the patient, thereby allowing sound decisions based on astute nursing assessment.

Anemia↗
PubMed1992

Problems of drug abuse, HIV and AIDS: the burden of care in one general practice.

Responsibility for many of the problems of intravenous drug abuse and human immunodeficiency virus (HIV) infection lies with community care agencies, such as general practitioners, community psychiatric and district nurses and drug agencies. It is in general practice that this burden is most clearly observed, given that general practitioners are in charge of the day-to-day care of patients. In an attempt to quantify this workload in an inner city practice with 11,200 patients, data were gathered from several sources relating to drug use and HIV infection. The study identified 432 patients who had consulted with problems of drug abuse and/or HIV infection over the period 1981-90. Among this group of patients 161 (37%) were HIV antibody positive. Among 191 drug abusers who were still registered with the practice in 1990 dihydrocodeine was the most commonly prescribed substitute treatment (130 patients) and only nine patients were prescribed methadone. Forty seven per cent of drug users continued to inject drugs occasionally. However, analysis of urine samples revealed that there was a shift away from injecting mainly heroin to multiple drug use, including benzodiazepines, usually originating from prescribed sources. Drug abusers who were HIV positive consulted their general practitioner significantly more often over one year than those who were not (mean 24.9 versus 15.8 consultations, P < 0.01). However, there was no significant difference between these two groups in terms of days spent in hospital. A total of 61 patients were referred to a community psychiatric nurse over an eight month period.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMedDate not supplied

Quality of care for women in northeast Thailand: intersections of class, gender, and ethnicity.

Based upon ethnographic fieldwork in a rural village community in Northeast Thailand, this article explores issues relating to the quality of care received in reproductive health services from the perspective of village women. Inequalities of power fundamental to gender, class, and ethnic relations are described as elements affecting the service-giving process. The subordinate position of village women is subtly reinforced in the spatial organization, style of communication, and management of the services.

Ethnicity↗