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Biomedical subjects

P Farrell

Publications and source records attributed to P Farrell.

17 recordsLinked to original sources
PubMed1991

Kinetic modeling as a prescription aid in peritoneal dialysis.

Methods for calculating fluid and mass removal in peritoneal dialysis are presented in order to aid clinicians in their care and management of patients and to assist them in their understanding of the physiological mechanisms which govern peritoneal transport. These methods are based on the Pyle-Popovich peritoneal mass transport model which encompasses both diffuse and convective transport as well as lymphatic flow and residual renal function. Algebraic solutions to the mass balance equations governing solute transport are provided. Since these solutions are expressed explicitly as functions of time, they are easily programmed for use on a personal computer or calculator. This offers considerable advantage over the more computer-intensive numerical solutions which had been previously required since one can now calculate both mass removal and changes in blood concentration at the end of an exchange without requiring any intermediate calculations. This computational advantage and the ability to model changes in blood concentration are shown to be of particular importance when modeling more dynamic therapies such as CCPD or Tidal peritoneal dialysis. Finally, the model and solutions, when assessed clinically among 5 patients on two separate occasions, resulted in predicted fluid and mass removals which were in high concordance with measured fluid and mass removals (concordance correlation coefficients in excess of 0.97). Our findings suggest that kinetic modeling can provide the kind of analytical tools necessary to guide clinicians in their care and management of peritoneal dialysis patients.

Algorithms↗
PubMed1990

Paradigm case analysis and stimulated recall: strategies for developing clinical reasoning skills.

Development of clinical reasoning skills was a major objective of a collaborative venture between a university school of nursing and a tertiary care teaching hospital. Two elective courses and an 8-month practicum were offered at the graduate level to students specializing in perinatal nursing. Through analysis of their own cases and those of clinical experts, students gained expertise in tracing the development of their decision-making skills. In the clinical practicum, where it was less feasible for the student and preceptor to withdraw from the clinical setting to discuss the decision-making process, "stimulated recall" was employed. This strategy uses segments of nurses' actual practice, on site, at the time of care delivery. In this way, the total context of the clinical reasoning process of nurses can be examined. In this paper, the two strategies are discussed with illustrations from the actual teaching/learning situations.

Decision Making↗
PubMed1990

Development and validation of an index for scoring baseline respiratory disease in the very low birth weight neonate. Severity Index Development and Validation Panels and Newborn Lung Project.

An accurate description of the population at risk for neonatal chronic lung disease is clearly of prime importance for comparative studies and the planning of interventions. Attempts to explain variations in chronic lung disease rates in such studies have been compromised by lack of a way of estimating the severity of the initial pulmonary disease as a risk factor. Therefore, a severity index was developed for use in very low birth weight (less than 1501 g) neonates. Special emphasis was placed on applicability of the index in the multicenter observational setting. Development followed a clinician panel approach, with the resulting index designed to capture clinical judgment of severity. The index was validated prospectively on neonates in a neonatal intensive care unit, and retrospectively using charts from nine hospitals nationwide. Correlations of the index with clinical judgment in the two samples were .95 and .93, respectively. In an additional validation the index combined with birth weight correctly predicted oxygen dependence status at 30 days in 36 of 42 neonates consecutively admitted to five neonatal intensive care units (P = .002). Birth weight and the severity index contributed about equally to the prediction, and therefore they seem to represent partly independent components of baseline propensity for prolonged oxygen dependence.

Apgar Score↗
PubMed1989

Neonatal screening for cystic fibrosis in Wisconsin.

Primary care physicians have been very cooperative in referring screened patients to the two designated CF centers in Wisconsin--the University of Wisconsin Cystic Fibrosis Center, and the center at the Medical College of Wisconsin in Milwaukee--and their help has made this study possible. By 1990, we anticipate that meaningful clinical comparisons between the screened and control groups will be possible, and at that time we can begin to obtain some definitive answers concerning the benefits and potential risks of neonatal screening for cystic fibrosis. At this time, it would be premature to make a decision concerning the efficacy of screening for cystic fibrosis for the State of Wisconsin. It is very important that the study go to completion before making conclusive recommendations. We are eager to meticulously document the natural history of CF by following study patients for a long time. Answers to questions concerning rate of decline of the IRT value in true positives, psychosocial risks of screening to true positives, effect on future reproductive plans, and the cost effectiveness of the screening program will not be available for at least two more years. False positive IRT results seem to be related to perinatal asphyxia. We postulate the mechanism is ischemia in the pancreas related to hypoxia during the perinatal period leading to transient release of trypsin from the pancreas into the bloodstream. Decline of the IRT result over time is of great interest because a repeat blood sampling approach would hopefully eliminate several false positives.(ABSTRACT TRUNCATED AT 250 WORDS)

Cystic Fibrosis↗
PubMed1987

Epstein-Barr virus gene expression in P3HR1-superinfected Raji cells.

The pattern of Epstein-Barr virus (EBV) RNAs expressed in Raji cells superinfected with P3HR1 EBV was examined. RNAs whose expression was of an immediate-early type (resistant to treatment of the cells with anisomycin) were identified. These RNAs, encoding the EBV reading frames BZLF1 and BRLF1, were probably expressed from defective virus within the P3HR1 preparation, and some of them were responsible for the induction of the EBV productive cycle in the Raji cells. The structures of the B95-8 RNAs equivalent to the anisomycin-resistant RNAs were determined. The RNA encoding the BZLF1 reading frame contained two splices which extended and modified the reading frame from that previously described.

Anisomycin↗
PubMed1985

Lifestyle counselling: the need for diagnostic clarity.

Three approaches to changing lifestyle behaviours are hypothesized. The argument that diagnostic accuracy is essential for selection of appropriate nursing interventions is developed and illustrated with clinical examples. The diagnoses of information deficiency, information and behavioural control deficiency, and contextual awareness deficiency guide the interventions for the problem of obesity.

Adult↗
PubMed1984

Spliced RNA from the IR1-U2 region of Epstein-Barr virus: presence of an open reading frame for a repetitive polypeptide.

We have constructed a cDNA library from the cytoplasmic RNAs of Raji cells, a Burkitt's lymphoma cell line latently infected with Epstein-Barr virus. We report here the characterization of a cDNA representing a spliced RNA transcribed from the IR1-U2 region of the viral genome. The cDNA is 1007 bp long. The 5' region contains three tandem repeats of two exons, 66 and 132 bp, which are transcribed from the IR1 repeats. The 3' region is formed from four exons transcribed from U2. An open reading frame extends from the 5' end to position 784, and includes the repeats. This reading frame presumably corresponds to the carboxy-terminal 261 amino acids of a polypeptide containing several repeats of a 66 amino acid sequence. Since it would be encoded by the IR1-U2 region of the viral genome, the putative polypeptide might be involved in the process of growth-transformation of B-lymphocytes.

Amino Acid Sequence↗
PubMed1980

Double-stranded RNA and the enzymology of interferon action.

Extracts from interferon-treated, not virus-infected Ehrlich ascites tumor cells differ in various biochemical characteristics from extracts of control cells. We studied three enzymes whose level is enhanced in cells upon treatment with IF and which are causing some of the differences. (2'-5')(A)n synthetase, an enzyme converting ATP into a series of (2'-5') linked oligoadenylates ((2'-5')(An)) in the presence of dsRNA was purified to homogeneity and characterized. The second enzyme, RNase L, a latent endonuclease, which can be activated by (2'-5')(A)n to cleave single-stranded RNAs, was purified several hundredfold. The activation of this enzyme is reversible and is lost upon removal of (2'-5')(A)n. The activation is not accompanied by a large change in shape of conformation of the enzyme. The third enzyme is a protein kinase which if activated by dsRNA can phosphorylate the peptide chain initiation factor eIF-2 and a protein designated P1 of 67,000 daltons. This enzyme was purified several thousandfold. The most highly purified preparation consists of three proteins with P1 as the most abundant component.

2',5'-Oligoadenylate Synthetase↗