Immunoexpression patterns for Hypoxia-inducible Factor-1α and von Hippel-Lindau protein, in relation to Hsp90, of human brain tumors.

The pathogenesis of many tumors, including brain tumors, has been associated with hypoxia, which induces the transcriptional activity of hypoxia-inducible Factor-1α (HIF-1α). HIF-1α is normally degradated by the von Hippel-Lindau protein (pVHL) but, in hypoxia, pVHL/HIF-1α interaction is inhibited resulting in the nuclear accumulation of HIF-1α. Hsp90 (Heat shock protein 90), as a chaperone protein, plays a critical role for both stabilization of HIF-1α and degradation of pVHL. The aim of this study was to estimate immunohistochemically the expression levels of HIF-1α and pVHL, in relation to Hsp90, in different types of human brain tumors (42 gliomas, 9 medulloblastomas, and 38 meningiomas) using specific antibodies. The tumors were further divided into two groups according to the age of patients (≥19 years old or ⟨19 years old). Nuclear, for HIF-1α, and cytoplasmic, for pVHL and Hsp90, localization was detected in a high percentage of tumor cells in the majority of tumors. In astrocytomas, a significant, grade-dependent relationship for HIF-1α immunoexpression was observed (p⟨0.05). Furthermore, there was a significant correlation between pVHL and Hsp90 immunoexpression (p⟨0.01). The group of ≥19 years old patients with glioblastomas (WHO grade IV) demonstrated significantly increased immunoexpression for HIF-1α compared to pVHL (p⟨0.0001) and Hsp90 expression (p⟨0.01). In medulloblastomas, a significant correlation of HIF-1α with Hsp90 immunoexpression (p⟨0.05) was found. In meningiomas, no significant correlation for the expression of the three proteins was detected (p≥0.05). These results indicate that HIF-1α/pVHL/Hsp90 interactions may be implicated in biology of different types of brain tumors through different signaling mechanisms.

Nursing activities and use of time in the postanesthesia care unit.

Specialty areas, such as the PACU, are currently characterized by a shortage of qualified nursing personnel along with the pressure for a most cost-conscious function of services. These, in combination with both the increasing acuity of patients and the advances of science and technology, have rendered necessary the investigation of how existing personnel can be better used. The work sampling approach has been widely used in different clinical settings to offer data about the amount of time nurses devote to specific activities. The aim of the current study was to categorize and quantify the activities of nurses employed in the PACU of the General University Hospital of Patras, Greece, and to identify differences with regard to shifts, varying nurse-patient ratios, and nurses' experiences. In the first phase, a classification form, which included all nursing activities, was constructed. This was based on literature review, researchers' experience, and semistructured personnel interviews. In the second phase, the researchers observed all PACU nurses, and activities were recorded on an hourly check sheet. A total of 4,320 observations were collected from 9/1/2004 to 9/30/2004. Nurses spent 35.2% of their time on direct clinical care, 11.6% on patient assessment, 7.0% on communication with patients, 7.2% on communication with other persons, 8.6% on clerical nursing duties, 9.3% on documentation, 2.3% on non-nursing duties, and 18.8% on personal activities. Variations in the use of time were found between shifts, different nurse-patient ratios, and PACU experience. Methods of decreasing time when the nurse-patient ratio is inappropriate and increasing time allocated to direct care activities are proposed.