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Biomedical subjects

C Farrelly

Publications and source records attributed to C Farrelly.

11 recordsLinked to original sources
PubMed2004

Genes and equality.

The way people think about equality as a value will influence how they think genetic interventions should be regulated. In this paper the author uses the taxonomy of equality put forth by Derek Parfit and applies this to the issue of genetic interventions. It is argued that telic egalitarianism is untenable and that deontic egalitarianism collapses into prioritarianism. The priority view maintains that it is morally more important to benefit the people who are worse off. Once this precision has been given to the concerns egalitarians have, a number of diverse issues must be considered before determining what the just regulation of genetic interventions would be. Consideration must be given to the current situation of the least advantaged, the fiscal realities behind genetic interventions, the budget constraints on other social programmes egalitarians believe should receive scarce public funds, and the interconnected nature of genetic information. These considerations might lead egalitarians to abandon what they take to be the obvious policy recommendations for them to endorse regarding the regulation of gene therapies and enhancements.

Ethics, Medical↗
PubMed1996

Sodium picosulphate compared with polyethylene glycol solution for large bowel lavage: a prospective randomised trial.

Mechanical efficiency, patient acceptability and minimal biochemical perturbation are important factors in the choice of lavage solution for bowel preparation. This prospective randomised trial of 59 patients compared a polyethylene glycol bowel lavage solution (Klean Prep) to a sodium picosulphate solution (Picolax) considering their efficacy from both colonoscopists' and radiologists' points of view, patient acceptibility, and plasma biochemical changes. The sodium picosulphate solution was more acceptable to patients than the polyethylene glycol, and resulted in significantly less nausea and vomiting (p = 0.0025), and far fewer consumption difficulties (p < 0.0001). Mean plasma biochemical changes were significantly different for magnesium (p < 0.001), chloride (p < 0.01) and potassium (p < 0.02). Because neither lavage solution displayed a marked advantage for the colonoscopist or radiologist, and sodium picosulphate was more acceptable to patients, sodium picosulphate is the preferred solution for bowel preparation. The changes in plasma biochemistry values are unlikely to cause clinical problems.

Adolescent↗
PubMed1995

Gas exchange in the insect tracheal system.

The role of the insect tracheal system in gas exchange during cyclic ventilation is investigated using mathematical models. Three models are presented, one to describe the important elements of gas exchange during each of the three phases of cyclic ventilation. The effects of normobaric hypoxia on gas exchange are then examined, first assuming the initial parameter values set for the tracheal system and, second, assuming conditions of tracheal hypertrophy produced by an increase in the cross-sectional area of the tubes in the tracheal system. An increase in tracheal tube cross-sectional area is an important adaptation to normobaric hypoxia, but only if the tracheae themselves are the primary sites of resistance to gas exchange. Under conditions where the spiracles are the sites of resistance to gas exchange, volume expansion of the tracheae, not an increased cross-sectional area per se, is the important adaptation to normobaric hypoxia.

Adaptation, Physiological↗
PubMed1994

GAS EXCHANGE THROUGH THE LUNGS AND GILLS IN AIR-BREATHING CRABS

Lung and gill performance in gas exchange have been evaluated in eight species of air-breathing crabs with two different lung circulatory designs, those with portal systems and smooth lung linings, and those without portal systems and with invaginated and evaginated lung linings. In all species, the lungs were extremely effective in oxygen uptake whilst the performance of the gills was inferior. An exception to this was Gecarcoidea natalis, which has gills highly modified for aerial gas exchange; its gills and lungs were equally efficient in O2 uptake. The relative efficiencies of the lungs and gills in CO2 excretion differed between species, with the gills being the major site of CO2 loss in the more amphibious species and the lungs having an increasingly important role in the more terrestrial crabs. The presence or absence of lung portal systems was not found to correlate with either saturation rates or efferent oxygen concentrations, with both lung types being extremely efficient in O2 uptake. The lungs with portal systems showed a large increase in oxygen content in the first lacunar bed and progressively smaller increases in the next two; these lungs may, therefore, have some reserve for exercise.

Journal Article↗
PubMed1992

Adaptations in skeletal muscle capillarity following changes in oxygen supply and changes in oxygen demands.

The effects of changes in oxygen supply and oxygen demands on fiber cross-sectional areas, capillary densities and capillary to fiber ratios were determined in three skeletal muscles of rat. The muscles examined were the vastus lateralis, soleus, and diaphragm. Reduced oxygen supply was produced by subjecting rats to ambient hypoxia, and increased oxygen demands were produced by subjecting rats to low ambient temperatures or treatment with thyroxin. Capillaries were visualized by injecting fluorescent dyes into the circulation. Muscles were quick frozen at resting lengths to preserve normal fiber geometry and were subsequently sectioned on a cryostat. All of the muscles sampled from animals in the experimental groups had elevated capillary densities. However, capillary to fiber ratios were not increased significantly in any muscle, for any experimental condition. Thus, all of the observed differences in capillarity were due to changes in the intrinsic rate of muscle fiber growth. Further, the relations of capillary density and capillary to fiber ratio to fiber area were the same as those obtained during normal maturation, suggesting that capillary growth is closely linked to the intrinsic rate of fiber growth.

Adaptation, Physiological↗
PubMed1992

Capillary perfusion in skeletal muscle.

Timed perfusions of capillaries in soleus, vastus lateralis, and diaphragm of rats were determined by injecting a fluorescent dye into the aorta or right atrium. At preselected time intervals after dye injection, the circulation was interrupted, skeletal muscles were excised and frozen, and numerical counts of capillaries were made from transverse sections of the muscles. When fluorescent dye was injected into the right atrium or injected relatively slowly into the aorta, 100% of the capillaries contained dye by 3 s in vastus lateralis, 5 s in diaphragm, and 7 s in soleus. Rapid injection into the aorta delayed capillary filling. The rapid appearance of dye in skeletal muscle microvasculature suggests that either all capillaries are open to plasma flow all of the time or that the time constant for reopening of closed capillaries is very short. Furthermore, the patterns of capillary filling in skeletal muscle appear to be independent of muscle fiber type.

Animals↗
PubMed1984

Occult neuroblastoma presenting with opsomyoclonus: utility of computed tomography.

The clinical and radiographic findings in 10 children with neuroblastoma presenting with opsomyoclonus are described and the literature is reviewed. Children with opsomyoclonus are often a diagnostic dilemma, as they may not have a palpable tumor or increased urinary catecholamines. Computed tomography (CT) is the most sensitive imaging method in locating tumors (100%) compared with plain radiography of the chest and abdomen (sensitivity 40%), excretory urography (50%), and 99mTc radionuclide bone scans (50%). The use of body CT significantly shortened the interval between initial presentation and final diagnosis and avoided multiple hospitalizations and unnecessary investigations for patients with persistent opsomyoclonus. Since most neuroblastomas are solitary lesions that may arise in the adrenal glands or along the sympathetic chain from the neck down into the pelvis, our policy is to use plain radiography, sonography, and 99mTc methylene diphosphonate (MDP) bone scans for the preliminary investigation of patients with opsomyoclonus. Body CT can then be tailored to suit the needs of the individual patients.

Abdominal Neoplasms↗
PubMed1984

CT manifestations of Menkes' kinky hair syndrome (trichopoliodystrophy).

A patient with Menkes' syndrome is reported. This patient has survived to the age of six years without mental retardation, and shows previously unreported computed tomographic (CT) findings of tortuous vessels and unusual osseous manifestations of undertubulation of long bones and posterior vertebral body scalloping.

Bone and Bones↗