Comparative physiological study of the wild type and the small colony variant of Pseudomonas aeruginosa 20265 under controlled growth conditions.

Small-colony variants (SCVs) of Pseudomonas aeruginosa are often found in chronically infected airways of patients suffering from cystic fibrosis. These slow-growing morphological variants have been associated with persistent and antibiotic-resistant infections. Nevertheless, the behavior of SCVs under varied availability of O2 and iron, two key variables relevant to the lung environment of CF patients and pathogenicity of P. aeruginosa, has not been systematically studied so far. In this work, the effects of O2 and iron were comparatively studied for a CF P. aeruginosa wild type (WT) strain and its SCV phenotype in a real-time controlled cultivation system. Significant differences in the behavior of these strains were observed and quantified. In general, SCV exhibited a higher fitness than the WT toward aerobic conditions. Under iron rich condition, and despite less release of total extracellular proteins, absence of flagellin and lower siderophore production, the SCV cells grown at fully aerobic conditions showed a higher specific growth rate and a significantly higher cytotoxicity in comparison with the WT cells. The strains behaved also differently towards iron limitation. The phenomena of limited O2 transfer from the gas to the liquid phase and enhancement of formation of virulence factors under conditions of iron limitation were much more profound in the SCV culture than in the WT culture. These results have important implications for better understanding the pathogenicity of P. aeruginosa and its small-colony variants.

Peter's anomaly: diagnosis by ultrasound biomicroscopy.

Peter's anomaly is a congenital corneal disorder characterized by a central leukoma and adhesions at the periphery of the corneal opacity. A 35-year-old man presented for clinical evaluation of suspected sclerocornea. High-resolution ultrasound biomicroscopy revealed iridocorneal adhesions throughout the anterior segment, a shallow anterior chamber, and abnormal hyper-reflectivity along the posterior corneal surface. Through ultrasound biomicroscopy, characteristics of Peter's anomaly were recognized, and a diagnosis was established. This case illustrates how ultrasound biomicroscopy aids in the clinical differentiation between Peter's anomaly and other causes of congenital corneal opacification.

Ethical considerations in home care of the oncology patient.

OBJECTIVES: To examine the context of home care and the values of providers and patients that lead to potential ethical conflicts. To discuss a normative model of ethical decision making, and to suggest resources for resolving ethical issues. DATA SOURCES: Published articles pertaining to ethical issues and home health care. CONCLUSIONS: Home care is a viable and beneficial alternative to hospital care for a variety of patients, yet home care can result in unique value conflicts between patients and their families, and patients and home care providers. Loss of privacy and determining who is in charge are several unique areas to home care that can lead to ethical problems. Policies, guidelines, value statements, and ethics committees are excellent resources to assist in ethical decision-making. IMPLICATIONS FOR NURSING PRACTICE: A workable method or model to resolve ethical problems, and resources to assist in ethical decision-making can provide home care providers with guidelines to analyze an ethical problem and the support to choose and act on the best option.

Whistleblowing in the OR: the ethical implications.

1. Whistleblowing highlights the positive social behavior that is intended to benefit others while concealing what is sometimes considered disloyal behavior. 2. Loyalty is one of the most important ethical values, but failure to recognize the limits of loyalty can lead to seriously unethical outcomes. 3. It is critical that the nurse contemplating whistleblowing exhaust all internal resources to resolve the wrongdoing before going outside the organization.