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P Holmes

Publications and source records attributed to P Holmes.

At least 19 recordsLinked to original sources
PubMed1992

Two consecutive thunderstorm associated epidemics of asthma in the city of Melbourne. The possible role of rye grass pollen.

OBJECTIVE: To document the clinical impact and identify the meteorological and environmental circumstances surrounding two epidemics of asthma exacerbations associated with thunderstorms in the city of Melbourne and to find a possible aetiology for these events. DESIGN: Collection of meteorological and environmental data from the Victorian Bureau of Meteorology and the Environment Protection Authority; collection of clinical data from metropolitan emergency departments and the Victorian Ambulance Service; and study of a cohort of affected patients with asthma and a control group of asthmatics who were not affected by the storms. SETTING: Tertiary institution. PATIENTS: Twelve storm-affected patients with asthma and 16 asthmatics not affected by the storms. INTERVENTION: Administration of a questionnaire, medical interview, pulmonary function tests and skin prick tests with common allergens. MAIN OUTCOME AND RESULTS: Both epidemics caused a major increase in the number of hospital attendances and admissions because of asthma exacerbation (five to ten fold rise). These events could not be related to atmospheric pollution or specific meteorological features of the storms. Patients affected by the second storm were significantly more likely to suffer from hay fever (P less than 0.05), rye grass pollen allergy (P less than 0.05) and allergy to rainfall released rye grass starch granules (P less than 0.025). CONCLUSIONS: Late spring thunderstorms in the city of Melbourne can trigger epidemics of asthma attacks. The seasonal nature of the phenomenon and the pattern of allergic responses found in affected patients suggest a possible aetiological role for rye grass pollen.

Air Pollution↗
PubMed1992

The rough (ro+) gene as a dominant P-element marker in germ line transformation of Drosophila melanogaster.

We describe a new vector for the P-element-mediated introduction of gene constructs into the germ line of Drosophila melanogaster. The P-element vector carries 6.8 kb of genomic DNA containing the rough gene (ro) from D. melanogaster and a polylinker (MCS) containing ten unique cloning sites. To demonstrate its utility, we have cloned into the MCS of this vector, the firefly luciferase (Luc)-encoding gene (luc) under the control of the D. melanogaster hsp70 promoter and have transformed flies with the resultant P-element. Single insertions of this element, whether in the hemizygous or homozygous condition, completely rescued the ro- mutation and directed heat-inducible synthesis of Luc mRNA and enzyme.

Animals↗
PubMed1992

Mechanism of grass-pollen-induced asthma.

Many asthmatics are sensitive to rye-grass pollen, but pollen grains are too large to penetrate the lower airways. Our aim was to investigate the mechanism by which rye-grass pollen causes asthma. A major allergen of rye-grass pollen, Lol pIX, is located in intracellular starch granules within pollen grains. In-vitro tests showed that pollen grains are ruptured in rainwater by osmotic shock, each grain releasing about 700 starch granules into the environment. These granules are small enough to enter the airways (less than 3 microns in diameter). The starch granules were present in atmospheric samples taken during the pollen season, and showed a 50-fold increase in atmospheric concentration on days following rainfall. Isolated granules elicited IgE-mediated responses in asthmatic patients, and 4 patients with rainfall-associated asthma who underwent an inhalation challenge test had striking bronchial constriction after exposure to starch granules. Starch granules released from rye-grass pollen seem to be capable of causing asthma.

Allergens↗
PubMed1992

Controllability and duration of stress alter central nervous system depressant-induced sleep time in rats.

Rats were exposed to either 80 escapable shocks or yoked inescapable shocks and then injected with several hypnotic doses of sodium pentobarbital, midazolam, or ethanol; their sleep-time duration was compared with that of naive controls. Inescapable shock exposure resulted in a significant increase in ethanol-induced sleep time compared with the escapable shock and naive control groups. Both escape and yoked groups showed an increase in barbiturate-induced sleep time compared with controls, although no difference was observed for midazolam. Acute stress (twenty 5-s inescapable shocks) did not alter the depressant-induced sleep time for any of the drugs tested. These results illustrate the importance of psychological aspects of stress and its influence on the potency of certain depressants.

Animals↗
PubMed1988

"Don't tell us--show us": the use of role play in the teaching of psychoanalytic theory.

The psychological concepts associated with psychoanalysis are sometimes considered to be precious and somewhat irrelevant by professionals working with disturbed adolescents. Discussions (at a theoretical level) of these ideas may not highlight their usefulness in clinical situations. This paper describes the use of active role play techniques in a staff training group designed to teach about the "Inner World of the Adolescent". The fundamental features of "transference" and "counter-transference" were brought alive during these groups, and several other theoretical contributions of modern psychoanalysis were demonstrated within the setting of a training session. These groups were not intended to train "therapists", but to support and improve existing styles of work with adolescents.

Adolescent↗
PubMed1987

A model for the periodic synaptic inhibition of a neuronal oscillator.

We develop a simple, piecewise linear differential equation with discontinuous jumps, which captures the essential characteristics of more complicated equations modelling the dynamics of neuronal oscillators, such as those due to Hodgkin & Huxley (1952), Fitzhugh (1960, 1961), and Nagumo et al. (1962). We investigate the effects of periodically applied stimuli of various durations and compare phase-transition curves or Poincaré maps for our model with numerically computed maps from the 'full' equations. We describe some aspects of the qualitative behaviour and bifurcations of these iterated one-dimensional mappings and attempt to relate them to experimental observations.

Action Potentials↗
PubMed1985

Fate of receptor-bound human chorionic gonadotrophin in pseudopregnant rat ovaries perfused in vitro.

Pseudopregnant rats were injected with [125I] hCG, anaesthesized 1 h later and after cannulation of the aorta the ovaries were isolated and perfused with Gey & Gey buffer containing 0.2% BSA. The release of radioactivity was monitored for 2 h and analyzed by gel filtration. Five to ten per cent of the radioactivity was released within 2 h and represented small molecular weight peptides and iodotyrosine and [125I]hCG. Analysis of the ovarian radioactivity prior to and after perfusion revealed that virtually all hCG was receptor-bound. Loading the medium with unlabelled hCG displaced [125I]hCG from the receptor but did not enhance its degradation. Histological examination showed that the ovarian tissues were still intact after the 2 h perfusion. Immunohistochemical studies revealed a localization of the hCG at the cell periphery both prior to and after perfusion. These results provide evidence showing that the rate of internalization of receptor-hCG complexes in rat luteal cells is slow in vivo.

Animals↗
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Expert Testimony↗