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Biomedical subjects

J Stark

Publications and source records attributed to J Stark.

At least 73 records · Page 4Linked to original sources
PubMed1996

Critical thinking for outcomes-based practice.

Critical thinking is a vital component in managing patient-related outcomes at the staff level. It involves making observations and then asking "why?" Critical thinkers explore connections between current events and other events, stretching the boundaries of the situation. This allows the critical thinker to make new associations, challenge the status quo, find subtle patterns, and arrive at new formulations to old issues. Although nurses are most often traditional thinkers, it is possible to develop or refine their critical thinking skills through participation in learning situations that focus on exploring new approaches to thinking.

Clinical Competence↗
PubMed1995

Multiple regions of yeast ribosomal protein L1 are important for its interaction with 5 S rRNA and assembly into ribosomes.

Yeast ribosomal protein L1 binds to 5 S rRNA and can be released from 60 S ribosomal subunits as an intact ribonucleoprotein particle. To identify residues important for binding of Saccharomyces cerevisiae rpL1 to 5 S rRNA and assembly into functional ribosomes, we have isolated mutant alleles of the yeast RPL1 gene by site-directed and random mutagenesis. The rpl1 mutants were assayed for association of rpL1 with 5 S rRNA in vivo and in vitro and assembly of rpL1 into functional 60 S ribosomal subunits. Consistent with previous data implicating the importance of the carboxyl-terminal 47 amino acids of rpL1 for binding to 5 S rRNA in vitro, we find that deletion of the carboxyl-terminal 8, 25, or 44 amino acids of rpL1 confers lethality in vivo. Missense mutations elsewhere in rpL1 also affect its function, indicating that multiple regions of rpL1 are important for its association with 5 S rRNA and assembly into ribosomes.

Alleles↗
PubMed1995

Left ventricular outflow tract obstruction in TGA: treatment with LV-to-PA valved conduit.

Progressive or recurrent left ventricular outflow tract obstruction after a previous Mustard or Senning operation represents a rare but challenging problem. The obstruction can be resected in some patients, but abnormal attachment of the mitral valve or a long fibromuscular tunnel represents a difficult surgical problem. Between 1979 and 1993, we encountered this type of left ventricular outflow tract obstruction in 10 patients, 4 to 13 years after the atrial repair. They ranged in age from 5 to 15 years (mean, 8.8 years) and weighed between 11.5 and 47 kg (mean, 25.3 kg). Operations were performed through a left thoracotomy with the patient on hypothermic cardiopulmonary bypass but without aortic cross-clamping. The left atrial appendage and descending aorta were cannulated. Good relief of the gradient was obtained in all patients (mean residual gradient, 14.8 mm Hg). All patients survived the operation. One patient died suddenly at home 6 months later; 2 patients required conduit replacement. All 9 long-term survivors are asymptomatic as of 6 months to 8 years after their conduit placement or replacement. We recommend the placement of a left ventricle-to-pulmonary artery valved conduit for the relief of severe left ventricular outflow tract obstruction arising after a Senning or Mustard operation that cannot be managed by other means.

Adolescent↗
PubMed1995

Replication-deficient adenovirus induces expression of interleukin-8 by airway epithelial cells in vitro.

Preclinical studies with first-generation adenovirus (Ad) vectors administered in vivo to the respiratory tract have demonstrated a nonspecific host response consisting, in part, of parenchymal neutrophil accumulation followed by mononuclear cell and macrophage accumulation. We hypothesized that the mechanism for this host response might be the elaboration of interleukin-8 (IL-8) and monocyte chemoattractant protein-1 (MCP-1) from the airway epithelium following the exposure to Ad. To evaluate this hypothesis, we infected A549 cells (a human-derived lung epithelial cell line) in vitro with an adenovirus type 5 (Ad5)-based vector expressing a nuclear targeted beta-galactosidase enzyme (Av1LacZ4). We found that cellular transduction was efficient, resulting in gene delivery to 85.5% +/- 3.9% of the cell monolayer after 96 hr. Importantly, IL-8 mRNA transcript levels in Av1LacZ4-transduced cells were significantly higher than uninfected controls by 24 hr and remained elevated for 96 hr. IL-8 protein secretion from Av1LacZ4-transduced cells was increased for the same period. The Av1LacZ4-transduced A549 cells also showed a neutrophil chemoattractant activity higher than control cells, measurable at 24 hr, and persisting for 96 hr. The chemoattractant activity could be neutralized by a specific monoclonal antibody to IL-8. Whereas Av1LacZ4 transduction induced IL-8 gene expression, there was a lack of expression of MCP-1 by A549 cells. These observations demonstrate that the gene delivery to the airway epithelium using the Ad5-based expression vector results in IL-8 gene activation in these cells, which may contribute to the described inflammatory host response.

Adenoviruses, Human↗
PubMed1995

Quo vadis paediatric cardiac surgery?

Some achievements in the treatment of congenital heart defects are discussed. Special comments are made about the persistent ductus arteriosus, atrial septal defect, transposition of the great arteries and the Fontan operation. The differences and similarities between 'corrective' and 'palliative' operations are discussed. The history of the development of supraregional centres in England and Wales is described and the current situation outlined. The relationship between the number of operations performed and results is emphasised. Current and future training of paediatric cardiac surgeons is discussed and proposals made for the future organisation of care for children with congenital heart defects. The author speculates about how these problems will be solved in view of the decreasing number of children with congenital heart defects. Impact of treatment on the families of patients with congenital heart defects is also considered.

Cardiology↗
PubMed1995

Late outcome of survivors of intervention for neonatal aortic valve stenosis.

BACKGROUND: This study examined the late outcome after intervention for neonatal aortic valve stenosis. METHODS: Seventy-three neonates (59 boys and 14 girls) underwent intervention for critical aortic valve stenosis during the first 30 days of life at two institutions, The Hospital for Sick Children, London, and Duke University Medical Center, Durham, North Carolina. Procedures performed include closed valvotomy (n = 12), open valvotomy with inflow occlusion (n = 14), open valvotomy with cardiopulmonary bypass (n = 33), balloon valvotomy (n = 12), and other procedures (n = 2). The mean age at the first intervention was 8 +/- 1 days. RESULTS: The hospital mortality was 52.1%. The mean duration of follow-up for the hospital survivors (n = 35) was 8.3 +/- 1.1 years. The actuarial survival for the hospital survivors was 93.3% +/- 4.7% at 10 years and 83.9% +/- 9.8% at 15 years, whereas event-free survival (reintervention, endocarditis, or early death) was 61.8% +/- 9.3% at 5 years, 34.2% +/- 10.8% at 10 years, and 27.4% +/- 10.6% at 15 years. Three patients have died and 11 patients have required aortic valve replacement during the follow-up period. The age at the initial intervention, the type of initial intervention, and the year of initial intervention were not predictive of early death or need for reintervention. At last follow-up, 26 of the long-term survivors (n = 32) were in functional class I and 6 were in functional class II. CONCLUSIONS: Aortic stenosis in the neonatal period is a difficult problem with a high initial mortality. Late survival and functional class are excellent for patients surviving the initial hospitalization, but most require further intervention within 10 years.

Aortic Valve Stenosis↗
PubMed1994

Tricuspid valve abnormalities in patients with atrioventricular discordance: surgical implications.

From 1975 to 1990, 90 patients (age, 6 months to 30 years; mean, 9.1 years) underwent operation for defects associated with atrioventricular discordance. Twenty-one had an anatomically abnormal tricuspid (systemic) atrioventricular valve (SAVV) of the following types: Ebstein, 11; straddling, 6; and dysplastic, 4. Sixteen valves were regurgitant: regurgitation was trivial to mild in nine and moderate to severe in seven. Two patients underwent a successful Fontan-type operation. None of the 5 patients with a competent SAVV underwent valve repair or replacement; 1 of these patients died. A ventricular septal defect was closed in 14 and an extracardiac valved conduit was placed in 7. Sixteen had a regurgitant valve: it was replaced in 10 and repaired in 2 (early mortality, 25%). All 4 patients who did not undergo repair or replacement of their regurgitant SAVV died. Two patients died late after repeat replacement. Four other reoperations (closure of a residual ventricular septal defect, SAVV replacement, left ventricle-to-pulmonary artery conduit replacement, and a redo Fontan procedure) were successful. Two patients are lost to follow-up, and 9 have been followed up for them 27 to 156 months (median, 117 months). All were well when last seen. We suggest that an abnormal regurgitant SAVV should be replaced. Alternatively, a "double-switch" procedure that leaves the tricuspid valve in the pulmonary circulation may be used.

Adolescent↗
PubMed1994

Competitive and territorial fighting: two types of offense in the rat.

Two types of fighting (offense) were compared and contrasted in three experiments on the laboratory rat. In Experiment 1, competitive fighting was obtained in pairs of hungry cagemates by placing one food pellet into their food hopper. In Experiment 2, territorial fighting was obtained by introducing an unfamiliar intruder into the home cage of a male and female pair. Both types of fighting had the same motor patterns. Whereas territorial fighting is strongest against intruders of the same sex, competitive fighting is stronger against the smaller opponent (in this case female) regardless of the sex of the test animal. Whereas territorial fighting is stronger in males, competitive fighting is stronger in females. Whereas gonadectomy reduces territorial fighting in males but not females, it reduces competitive fighting in both sexes. In experiment three, it was shown that food deprivation increases competitive fighting, while it reduces territorial fighting. On the basis of these findings a revised model of the organization of the offense motivational system is proposed.

Aggression↗
PubMed1994

Acute renal failure in trauma: current perspectives.

Trauma complicated by acute renal failure provides a challenge for the members of the critical care team. Clinicians face a wide range of clinical problems complicated by a climbing mortality rate, as high as 70%. To meet this challenge, clinicians need an understanding of the most recent studies, so they can determine whether the findings can be translated into practice. In addition, prevention needs to be made the frontline of care, and when this is not possible, the second consideration must be directed at selecting therapeutic modalities for the creation of a nonoliguric acute tubular necrosis. These efforts will assure that patients receive the most current and comprehensive care. This article supports these efforts by providing an explanation of the pathogenesis of acute tubular necrosis on a cellular level and interpreting this information on a renal structural level, as well as into the clinical practice by including a description of a variety of medical and nursing modalities as found in the literature.

Acute Kidney Injury↗
PubMed1994

The nurse moderator role in making the critical difference.

The Making the Critical Difference continuing education program offers the critical care nurse a unique opportunity to assume the nurse moderator role. This article guides the nurse in the preparation for this role by providing detailed explanations and practical advice.

Critical Care↗