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Biomedical subjects

M J Fagan

Publications and source records attributed to M J Fagan.

At least 37 records · Page 2Linked to original sources
PubMed1995

Pediatric asthma care in US emergency departments. Current practice in the context of the National Institutes of Health guidelines.

OBJECTIVES: To determine whether US emergency department care for pediatric asthma conforms to the National Institutes of Health guidelines and whether the guidelines are likely to be adopted in clinical practice. DESIGN: Mail survey conducted from January to April 1992, and stratified by hospital type (children's, public and community). SETTINGS: Emergency departments of US hospitals. PARTICIPANTS: Simple stratified random sample of emergency department directors from 376 sampled hospitals. MEASUREMENTS: Self-reported data on emergency department pediatric asthma care, and knowledge and attitudes about the National Institutes of Health guidelines. Data are reported as mean (+/- SE). RESULTS: Sixty-eight percent of the surveyed emergency department directors responded. During 1991, there were an estimated 1.6 million visits for pediatric asthma care. Asthma accounted for 16.9% (+/- 9.0%) of all pediatric emergency department visits. Only 2.1% (+/- 1.0%) reported the use of written protocols or guidelines, with significant variation by hospital type. Sixty-seven percent (+/- 3.0%) reported the use of pulse oximetry. Eighty percent reported the use of beta-agonists by inhalation as the initial treatment. Only 44.7% (+/- 2.9%) reported the use of steroids if there was a poor response to the initial treatment. An estimated 45.5% (+/- 3.9%) of respondents had heard of the guidelines at the time of this survey; approximately 24% reported that they had read the guidelines. Most respondents reported that the guidelines were credible, clear and concise, and likely to be adopted in their emergency department. CONCLUSIONS: These data suggest that reported pediatric asthma care in US emergency departments differs substantially from the National Institutes of Health guidelines, with considerable variation by hospital type. The guidelines appear to provide an acceptable tool for emergency departments to use in assessing their pediatric asthma care. However, in light of the lack of evidence that the guidelines will improve outcomes, the impact of national guideline adoption remains unclear.

Asthma↗
PubMed1995

Glucose metabolism in 'Sphingomonas elodea': pathway engineering via construction of a glucose-6-phosphate dehydrogenase insertion mutant.

'Sphingomonas (formerly Pseudomonas) elodea' produces the industrially important polysaccharide gellan when grown in media containing glucose. Glucose catabolic enzymes and enzymes of central carbon metabolism were assayed in crude extracts of glucose-grown cultures of this bacterium. Based on these analyses it was concluded that glucose is converted to either gluconate or glucose 6-phosphate and that both of these products are converted to 6-phosphogluconate, a precursor for the Entner-Doudoroff (ED) and pentose phosphate pathways. Phosphoglucoisomerase (Pgi) activity was detected, but the lack of phosphofructokinase activity indicated that the Embden-Meyerhof glycolytic pathway is non-functional for glucose degradation. Thus, this bacterium utilizes glucose mainly via the ED and pentose phosphate pathways. Enzyme analyses suggested the involvement of glucose-6-phosphate dehydrogenase (Zwf) in glucose utilization and CO2 production. The zwf gene was cloned from 'S. elodea' and partially sequenced, and a null zwf mutant was constructed. This mutant exhibited no Zwf activity in in vitro assays, grew normally on glucose minimal medium and accumulated biomass (cells plus gellan) and produced CO2 at the same rates as the parental strain. Potential explanations for this finding are provided. Clones carrying the pgi gene were isolated fortuitously.

Amino Acid Sequence↗
PubMed1994

P-type ATPases of eukaryotes and bacteria: sequence analyses and construction of phylogenetic trees.

The amino acid sequences of 47 P-type ATPases from several eukaryotic and bacterial kingdoms were divided into three structural segments based on individual hydropathy profiles. Each homologous segment was (1) multiply aligned and functionally evaluated, (2) statistically analyzed to determine the degrees of sequence similarity, and (3) used for the construction of parsimonious phylogenetic trees. The results show that all of the P-type ATPases analyzed comprise a single family with four major clusters correlating with their cation specificities and biological sources as follows: cluster 1: Ca(2+)-transporting ATPases; cluster 2: Na(+)- and gastric H(+)-ATPases; cluster 3: plasma membrane H(+)-translocating ATPases of plants, fungi, and lower eukaryotes; and cluster 4: all but one of the bacterial P-type ATPases (specific for K+, Cd2+, Cu2+ and an unknown cation). The one bacterial exception to this general pattern was the Mg(2+)-ATPase of Salmonella typhimurium, which clustered with the eukaryotic sequences. Although exceptions were noted, the similarities of the phylogenetic trees derived from the three segments analyzed led to the probability that the N-terminal segments 1 and the centrally localized segments 2 evolved from a single primordial ATPase which existed prior to the divergence of eukaryotes from prokaryotes. By contrast, the C-terminal segments 3 appear to be eukaryotic specific, are not found in similar form in any of the prokaryotic enzymes, and are not all demonstrably homologous among the eukaryotic enzymes. These C-terminal domains may therefore have either arisen after the divergence of eukaryotes from prokaryotes or exhibited more rapid sequence divergence than either segment 1 or 2, thus masking their common origin. The relative rates of evolutionary divergence for the three segments were determined to be segment 2 < segment 1 < segment 3. Correlative functional analyses of the most conserved regions of these ATPases, based on published site-specific mutagenesis data, provided preliminary evidence for their functional roles in the transport mechanism. Our studies define the structural and evolutionary relationships among the P-type ATPases. They should provide a guide for the design of future studies of structure-function relationships employing molecular genetic, biochemical, and biophysical techniques.

Adenosine Triphosphatases↗
PubMed1988

Relationship between nurses' assessments of perfusion and toe temperature in pediatric patients with cardiovascular disease.

This descriptive study reports on 17 children who had undergone open-heart surgery. The children were assessed for 6 hours after surgery and once at 18 hours after operation to determine relationship between two scales assessing peripheral perfusion and the temperature of the great toe. There were 119 individual assessments. The scales used to assess the quality of peripheral pulses, extremity warmth, and capillary refill were (1) those representative of assessment scales used in common nursing practice and (2) more specific scales that attempt to "quantify" the qualitative assessment of peripheral perfusion. The more specific set of scales was used by "trained observers," with the bedside nurse using the nurses' scales. Results demonstrated that both sets of scales and observers were accurate in assessing peripheral perfusion as measured by the actual toe temperature. Analyses revealed which scales were better than others, and a method of assessing peripheral perfusion that includes the best components of all scales is suggested.

Adolescent↗
PubMed1986

Role of the collar on the femoral stem of cemented total hip replacements.

Three dimensional finite element models with realistic loading conditions were used to analyse the role of the collar of cemented total hip stems. Three types of implant were considered: large collared stems, small collared stems and totally collarless stems. A computer model of the natural femur provided an indication of the bone stresses before hip replacement, and thus aided the identification of possible mechanisms of bone resorption. In particular, resorption of the medial femoral neck was examined, and its effect on the stress distribution within the stem-cement-bone structure is discussed. The results indicate that loss of bone at the femoral neck is a serious symptom for any design of implant. The factors leading to the resorption are complex but it is clear that it is not a consequence of simple stress shielding of the bone. The most likely cause is the manner in which the stem moves within the femoral shaft, which is a function of whether the stem is collared or not.

Biomedical Engineering↗
PubMed1985

Tropical pulmonary eosinophilia associated with pleural effusions.

A 28-year-old Indian female presented with shortness of breath, white cell count of 27,400 with 39% eosinophils, and increased interstitial markings and bilateral pleural effusions on chest x-ray. Although the clinical presentation was consistent with tropical pulmonary eosinophilia (TPE), to our knowledge there has been only one previous report in the world's literature of pleural effusion associated with TPE. We suggest that pleural effusions are not incompatible with the diagnosis of TPE and that TPE be added to the list of conditions causing eosinophilic pleural effusions.

Adult↗