Ozone-Induced Pulmonary Functional, Pathological, and Biochemical Changes in Normal and Vitamin C-Deficient Guinea Pigs

Since Vitamin C (ascorbate, AH₂) is an important airway antioxidantand is an essential component of tissue repair, and since acute(4 hr) O₃ toxicity is enhanced by AH₂ deficiency, we hypothesizedthat longer-term O₃ effects might also be increased. FemaleHartley guinea pigs (260–330 g) were fed either an AH₂-sufficientor an AH₂-deficient diet 1 week prior to exposure, and weremaintained on their respective diets during 1 week of continuousexposure to O₃ (0, 0.2, 0.4, and 0.8 ppm, 23 hr/day), and during1 week postexposure recovery in clean air. The AH₂-deficientdiet caused lung AH₂ to drop to about 30% of control in 1 week,and to below 10% by the end of exposure and recovery. Body weightgains during exposure were decreased in the 0.8 ppm O₃ group,while the AH₂ deficiency began to affect body weights only duringrecovery. O₃ caused a concentration-dependent decrease in totallung capacity, vital capacity, carbon monoxide diffusing capacity,nitrogen washout, and static compliance, while increasing forcedexpiratory flow rates and residual or end-expiratory volume(suggestive of pulmonary gas-trapping). The lung/body weightratio and fixed lung displacement volume were also increasedin O₃-exposed animals. Lung pathology consisted of mononuclearcell and neutrophil infiltration, airway as well as alveolarepithelial cell hyperplasia, and general decrease in epithelialcell cytoplasm. Thickening of the interstitium and an apparent increase in collagenstaining were seen at the terminal bronchiolar regions. Someof these effects were marginally exacerbated in AH2-defi- cientguinea pigs. One week postexposure to air reversed all O₃-inducedabnormalities, irrespective of AH₂ deficiency. Whole lung hydroxyprolineand desmosine were not changed at any time by either 0₃ or AH₂deficiency. Measurement of lung prolyl hydroxylase activitysuggested that AH₂ deficiency as well as 0₃ exposure may haveincreased the tissue levels of this enzyme. The lack of a significantincrease in toxicity with the longer-term exposure scenariosuggests that AH₂ has minimal influence on other compensatorymechanisms developed over time.     

Closing the theory—practice gap: a model of nursing praxis

Summary

• ? Despite the efforts of nursing theorists, educationalists and practitioners, the theory-practice gap continues to defy resolution. This paper argues that only by reconsidering the relation between theory and practice can the gap be closed.
• ? Drawing upon ideas from teaching and other practice-based disciplines, including nursing, the article suggests that the current model of viewing theory as informing and controlling practice should give way to a mutually enhancing model in which theory is derived from practice, and in turn influences future practice.
• ? This coming together of theory and practice is referred to as nursing praxis, and suggests that informal theory should be unique to each individual encounter with each patient.
• ? The clinical nurse is thus not only a practitioner, but a theorist and researcher, who responds to patients not according to some grand, inflexible theory, but by the process of reflection-in-action, drawing upon their expertise and a repertoire of past experiences and encounters.

     

SITE VARIABILITY IN A MULTISITE GERIATRIC DEPRESSION TRIAL

We studied differences in outcome and characteristics among 29 clinical sites of a multisite, double-blind antidepressant trial for geriatric depression. Six hundred and seventy-one outpatients aged 60 years or older (mean±SD=67.7±5.7) met DSM-III-R criteria for unipolar major depression, had baseline 17-item Hamilton Depression Rating Scale (HAMD₁₇) scores ≥16 and were randomized to fluoxetine (20 mg daily) or placebo. Effect sizes (ESs, expressed as mean differences between effects divided by the pooled standard deviation of the differences) were calculated for each site using selected outcome measures. ES ranged from 1.84 (favoring fluoxetine) to −0.91 (favoring placebo) for incidence of remitters (endpoint HAMD₁₇ total score of ≤8). A large, positive ES favoring fluoxetine for remission rates (ES≥0.65) was found at only six sites, moderate ES (0.35–0.64) at eight and small ES (0–0.34) at seven; ES favored placebo (<0) at eight of 29 sites. Private clinics showed an overall HAMD₁₇ ES for change scores more than twice that of university sites. These results suggest that individual practitioners may have vastly different clinical experiences in large, multisite trials for geriatric depression. Interrater reliability, subject selection, recruitment, inadequate or fixed dosing, few patients per site, brief study duration, heterogeneity of geriatric depression, financial incentive and characteristics of individual sites may contribute to response variability.     

Intensive Hypnotherapy for Smoking Cessation:A Prospective Study 1

This study reports on a prospective pilot trial of intensive hypnotherapy for smoking cessation. The hypnotherapy involved multiple individual sessions (8 visits) over approximately 2 months, individualization of hypnotic suggestions, and a supportive therapeutic relationship. Twenty subjects were randomly assigned to either an intensive hypnotherapy condition or to a wait-list control condition. The target quitting date was 1 week after beginning treatment. Patients were evaluated for smoking cessation at the end of treatment and at Weeks 12 and 26. Self-reported abstinence was confirmed by a carbon-monoxide concentration in expired air of 8 ppm or less. The rates of point prevalence smoking cessation, as confirmed by carbon-monoxide measurements for the intensive hypnotherapy group, was 40% at the end of treatment; 60% at 12 weeks, and 40% at 26 weeks (p < .05).     

BLACK PIGMENT STONE IN A MALE CHILD AGED TWO YEARS AND SEVEN MONTHS

A case of cholelithiasis is reported occurring in a boy aged two years and seven months. The patient presented with biliary colic, and cholecystectomy was performed. Detailed analysis of the stone, including electron-probe studies, showed it to be an example of a polybilirubinate stone, containing also calcium, carbonate, and phosphate, with some sulphur, sodium, and magnesium. There were also traces of chlorine, aluminium, copper, nickel, and manganese.     

Supraventricular Electrical Interaction in Conjoined Twins with Common Coronary Sinus

Conjoined twins with echocardiographic evidence of continuity of the coronary sinuses had identical heart rates on ECG. Both had broad, polyphasic QRS complexes, and various imaging modalities were unable to determine whether there was ventricular myocardial continuity. Administration of adenosine demonstrated that the broad polyphasic complexes were a "fusion" of the twins' individual QRS complexes, which could be clearly distinguished after administration of the drug. Ventricular pacing resulted in dissociation of the individual QRS complexes, thus demonstrating an absence of ventricular myocardial continuity. This was confirmed when the twins were successfully separated at the age of 10 months.     

Improving patient safety using the sterile cockpit principle during medication administration: a collaborative,unit-based project

Aim To implement the sterile cockpit principle to decrease interruptions and distractions during high volume medication administration and reduce the number of medication errors. Background While some studies have described the importance of reducing interruptions as a tactic to reduce medication errors, work is needed to assess the impact on patient outcomes. Methods Data regarding the type and frequency of distractions were collected during the first 11 weeks of implementation. Medication error rates were tracked 1 year before and after 1 year implementation. Results Simple regression analysis showed a decrease in the mean number of distractions, (β = −0.193, P = 0.02) over time. The medication error rate decreased by 42.78% (P = 0.04) after implementation of the sterile cockpit principle. Conclusions The use of crew resource management techniques, including the sterile cockpit principle, applied to medication administration has a significant impact on patient safety. Implications for nursing management Applying the sterile cockpit principle to inpatient medical units is a feasible approach to reduce the number of distractions during the administration of medication, thus, reducing the likelihood of medication error. ‘Do Not Disturb’ signs and vests are inexpensive, simple interventions that can be used as reminders to decrease distractions.