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Peter White

Publications and source records attributed to Peter White.

43 records · Page 3Linked to original sources
PubMed2002

Patient satisfaction with bronchoscopy.

We conducted a cohort study to characterize patient satisfaction with flexible bronchoscopy (FB) and to determine patient characteristics, care factors, and patient evaluations of bronchoscopy that are associated with a patient's willingness to return for repeat FB. Physicians and patients completed surveys between February 1997 and June 1998. Data from 481 patients were analyzed. Over 80% of the patients rated physicians as very good or excellent, but they were least satisfied with the information that they were provided about FB, waiting time before and after FB, and the FB environment. Seventy-one percent of the patients would definitely return, and 22% would probably return for a repeat FB. Better health status (odds ratio [OR] 1.4; 95% confidence interval [CI], 1.1-1.7), not being bothered by scope insertion (OR 2.0; 95% CI, 1.2-3.3), better rating of information quality (OR 1.2; 95% CI, 1.0-1.3), and better rating of physician quality (OR 1.1; 95% CI, 1.0-1.2) were associated with patients reporting that they would definitely return for a repeat FB. Although patient satisfaction with providers is high, there are specific patient and process of care factors that should be improved. Sicker patients may be at a risk of dissatisfaction with FB. Process of care measures that could improve satisfaction with FB include providing better information to patients and optimizing the experience of bronchoscope insertion.

Adolescent↗
PubMed2002

129X1/SvJ mouse strain has a novel defect in inflammatory cell recruitment.

Vitamin D-binding protein (DBP) has been reported to contribute to innate immunity. To verify prior in vitro and cell-based observations supporting this role, we assessed the ability of a recently developed DBP-null mouse line to recruit neutrophils and macrophages to a site of chemical inflammation. The interrupted DBP allele had been generated by homologous recombination in 129X1/SvJ embryonic stem cells and these cells were subsequently used to generate a line of DBP(-/-) (null) mice. Initial studies revealed a marked defect in the ability of these DBP(-/-) mice to recruit cells to the peritoneum after localized thioglycolate injection. However, progressive outcrossing of the DBP(-/-) mice to the C57BL/6J strain, conducted to provide a uniform genetic background for comparison of DBP-null and control mice, resulted in a progressive increase in cell recruitment by the DBP(-/-) mice and a loss in their apparent recruitment defect when compared with the DPB wild-type controls. These data suggested that the observed recruitment phenotype initially attributed to the absence of DBP was not linked to the DBP locus, but instead reflected the underlying genetic composition of the 129X1/SvJ ES cells used for the initial DBP gene disruption. A profound cell recruitment defect was confirmed in the 129X1/SvJ mice by direct analysis. Each of three commonly used inbred lines was discovered to have a distinct level of cell recruitment to a uniform stimulus (C57BL/6J > BALB/c > CD1 > 129X1/SvJ). Thus, this study failed to support a unique role for DBP in cellular recruitment during a model inflammatory response. Instead, the data revealed a novel and profound defect of cell recruitment in 129X1/SvJ mice, the strain most commonly used for gene deletion studies.

Animals↗
PubMed2002

Decreased actin solubility observed during ATP-depletion is mimicked by severing agents but not depolymerizing agents in isolated and cultured proximal tubular cells.

The microvilli of the apical membrane of proximal tubule (PT) cells are supported by the underlying actin cytoskeleton. Ischaemic or anoxic ATP-depletion leads to the disruption of the actin cytoskeleton, resulting in microvillar retraction and loss of membrane polarity. Using isolated PT cells, we have previously demonstrated that actin filaments (F-actin) are likely severed during ATP-depletion. A sequential extraction protocol revealed a decrease in actin solubility, resulting in the sequestration of a distinct F-actin pool with the insoluble cellular complex in ATP-depleted PT cells. We demonstrate here that decreased actin solubility is not only a reliable end-marker of ATP-depletion induced injury in freshly isolated PT cells, but also serves as a biochemical marker in the cultured proximal tubular cell line LLC-PK1. In the present studies, we also investigated specific actin-binding drugs to determine if they mimic the effects observed during energy depletion. Jasplakinolide (JP), a compound which binds F-actin and prevents depolymerization, did not effect actin solubility during ATP-depletion. Furthermore, swinholide A (SA), an F-actin severing agent, resulted in decreased actin solubility, mimicking the effects of ATP-depletion. Interestingly, latrunculin A (LA), an agent which depolymerizes F-actin, did not reduce actin solubility, but rather resulted in an increase in digitonin-soluble actin. Taken collectively, our results support previous work and suggest that disruption of the actin cytoskeleton during ATP-depletion is mediated by F-actin severing/fragmentation and not depolymerization. The differential effects of F-actin disrupting agents and the consistencies observed in both models of ischaemic injury will provide a basis for a more detailed understanding of the pathological events of PT-cell dysfunction.

Actins↗
PubMed2002

Outcome from mechanical ventilation after autologous peripheral blood stem cell transplantation.

STUDY OBJECTIVE: To report the outcome of patients with autologous peripheral blood stem cell transplantation (PBSCT) receiving mechanical ventilation. DESIGN: Retrospective observational study. SETTING: Active hematopoietic stem cell transplantation center and a university hospital medical ICU. PATIENTS: Patients with autologous PBSCT receiving mechanical ventilation. METHOD: A review of the medical records of patients with autologous PBSCT receiving mechanical ventilation. Data collection was restricted to the first episode of mechanical ventilation. RESULTS: A total of 78 autologous PBSCT patients received mechanical ventilation for > 24 h. Twenty patients (26%) were extubated and discharged alive from the hospital. Thirteen hospital survivors (60%) were alive at 6 months. Lung injury (LI), vasopressor use, and hepatic and renal failure (HRF) were used to predict survival after mechanical ventilation. Sixty patients (76%) had no organ failure, or had isolated LI or only required treatment with vasopressors. Their hospital survival and 6-month survival were 32% and 20%, respectively. Hospital and 6-month survival for the patients with HRF or LI and vasopressor use was 6% and 0%, respectively. CONCLUSIONS: Prolonged mechanical ventilation and aggressive ICU support is justified for autologous PBSCT patients receiving mechanical ventilation with no organ failure, or who have only isolated LI, or who only require treatment with vasopressors.

Adult↗
PubMed2002

Aerobic fitness, fatigue, and physical disability in systemic lupus erythematosus.

OBJECTIVE: To measure aerobic fitness, muscle strength, fatigue, and physical disability in patients with systemic lupus erythematosus (SLE). METHODS: Ninety-three patients with SLE and 41 sedentary controls were recruited into the study. Aerobic fitness was assessed by monitoring peak and submaximal oxygen uptake, heart rate, duration of exercise, and perceived exertion during a treadmill-walking test. Strength was measured using voluntary isometric quadriceps contraction. Symptomatic measures included physical and mental fatigue, mood, sleep, and functional incapacity. RESULTS: Compared to sedentary controls patients with SLE had significantly reduced levels of aerobic fitness (mean VO2peak SLE patients, 23.2 ml/kg/min vs controls, 29.6 ml/kg/min; p < 0.001) and reduced exercise capacity (mean exercise duration SLE patients, 10.4 min vs controls, 13.1 min; p < 0.001). The SLE patients also had reduced muscle strength (mean maximum voluntary quadriceps contraction SLE patients, 298 N vs controls, 376 N; p = 0.003). Resting lung function was also significantly worse in the SLE patients (mean FEV, SLE patients, 2.6 l vs controls, 2.9 l; p = 0.002). Fatigue (p < 0.001), depressed mood (p < 0.001), poor sleep quality (p < 0.001), and functional incapacity (p < 0.001) were all significantly greater in the SLE patients. Linear regression models suggested that physical disability correlated with aerobic fitness (p < 0.001), fatigue (p = 0.005), body mass index (p = 0.01), and depression (p = 0.05) and that fatigue correlated with depression (p < 0.001). CONCLUSION: Patients with SLE were less fit with reduced exercise capacity, reduced muscle strength, more fatigue, and greater disability compared to sedentary controls. Treatments developed to manage depression and improve aerobic fitness should be considered in the overall treatment of fatigue and disability in SLE.

Adult↗