The role of oxygen therapy in the recovery phase of day surgery

Oxygen therapy in the inpatient setting is standard practice in the postoperative phase. The aim of this study was to evaluate the need for the routine use of oxygen in the transit phase from the operating theatre to recovery, and its continued use in recovery, in patients undergoing day surgery. ASA I–II patients undergoing body surface surgery, using anaesthetic agents with a rapid recovery profile, are not subject to many of the factors that predispose to postoperative hypoxaemia. This study showed that in our unit the majority of patients do not require oxygen therapy in the theatre-recovery transit phase, and that attention to patient positioning, airway patency, and elimination of the second gas effect may be sufficient. Each day surgery unit (DSU) must make decisions on the need for postoperative oxygen therapy based on the unit layout and the condition of the patient.     

Role of stromal populations in hemopoietic stem cell proliferation. I. Physically distinct subpopulations of hemopoietic stem cells and stromal progenitors determine long-term culture hemopoiesis

The in vitro study of stem-cell-stromal-cell interactions has previously been made possible by the existence of a technique for long-term murine marrow culture, but the occurrence of both stem cells and stromal cells in fresh bone marrow (BM) explants and the heterogeneity of stromal cells have delayed functional categorization. Therefore, single-cell suspensions of murine BM were passed over nylon wool columns to allow fractionation of cells having distinctive function for in vitro hemopoiesis. A subpopulation of nylon-column-nonadherent (NNA) cells (20% +/- 1% total cells) is devoid of stromal progenitors that form the in vitro microenvironment, but the NNA subpopulation has control numbers of hemopoietic colony-forming cells, GM-CFU-C, and high-proliferative-potential colony forming cells (HPP-CFC). This subpopulation also produces control numbers of in vivo spleen colony-forming cells, CFU-S, and has control numbers of primitive, noncycling colony-forming cells that resist in vitro treatment with 5-fluorouracil (5-FU). By contrast, nylon-adherent populations, when eluted by mechanical agitation (MA) (41% +/- 1%) or by subsequent EDTA treatment (CA) (6% +/- 1%) could reform the hemopoietic microenvironment in vitro. Stromal progenitor cells were negative for surface markers Thy-1 and Mac-1. When NNA stem cells were added to culture with nylon-adherent stromal fractions, lodgement of stem cells occurred, resulting in stem cell proliferation for up to three months.     

Characteristics of female psychiatrists

OBJECTIVE: This study assessed within-gender differences between psychiatrists and other physicians by using data taken from a large national sample of U.S. female physicians. METHOD: The authors used data from the Women Physicians' Health Study, a large, national questionnaire-based survey conducted in 1993-1994, to compare characteristics of female psychiatrists (N=570) with those of other female physicians (N=3,875). RESULTS: Psychiatrists were older, in poorer health, less likely to be married, more likely to be current or ex-smokers, and more likely to be politically liberal than were the other female physicians. Psychiatrists were somewhat (although not necessarily significantly) more likely than the other female physicians to report having had personal or family histories of various psychiatric disorders. Psychiatrists were more likely to have a solo practice and less likely to be in a group practice. They worked fewer hours than the other female physicians but reported comparable hourly incomes. Psychiatrists did not differ from the other female physicians in perceived work amount, work stress, work control, or career satisfaction. Their satisfaction with their specialty was, however, greater than that of the other female physicians. For nearly all of the 14 preventive health care counseling practices examined, the amount of preventive counseling psychiatrists reported performing, the clinical relevance they ascribed to those practices, their self-confidence in performing the practices, and the amount of training they reported receiving in preventive counseling practices was significantly lower than that of primary care practitioners and lower than or comparable to that of other specialists. CONCLUSIONS: Female psychiatrists significantly differ from other female physicians with regard to a number of personal and professional dimensions.     

Response to a fluid load in athletes with a history of exercise induced hyponatremia

PURPOSE: To determine whether athletes who had previously developed hyponatremia during an ultradistance triathlon show an impaired ability to excrete a large fluid load compared with athletes who had completed the same race without developing hyponatremia. METHODS: Six athletes who had developed hyponatremia ([Na] < 135 mmol x L(-1)) in the 1997 Ironman Triathlon (study cases) were compared with six athletes who completed the same race without hyponatremia (controls). All participants consumed 3.4 L of water over 2 h at rest. Weight, urine output, urine electrolytes, serum [Na(+)], hemoglobin, and hematocrit were measured every 30 min. Changes in plasma volume and residual fluid volume in the gut were estimated from these data. RESULTS: There were no significant differences between cases and controls in any parameters measured. Maximal rates of urine production (+/- SD) (1043 +/- 331 mL x h(-1) for cases, 878 +/- 168 mL x h(-1) for controls) were substantially behind the rate of fluid intake (1500 mL x h(-1)). Consequent to fluid retention, serum [Na(+)] fell progressively in both groups. Five cases and four controls developed hyponatremia. There was an inverse correlation between change in body weight and change in [Na(+)] (r = -0.67). Estimated changes in the intra- and extra-cellular fluid volumes could account for all the retained fluid, and there was little evidence for fluid accumulation in the bowel. CONCLUSION: When evaluated at rest, there does not appear to be any unique pathophysiological characteristic that explains why some athletes develop hyponatremia in response to fluid overload during prolonged exercise. Rather, hyponatremia was induced with equal effect in both cases and controls, consequent to progressive fluid overload of all the body fluid compartments and without evidence for fluid retention in the small bowel.     

Radiolabeling and in vivo behavior of copper-64-labeled cross-bridged cyclam ligands.

Macrocyclic chelators and their metal complexes have widespread applications in the biomedical sciences, including radiopharmaceutical chemistry. The use of copper radionuclides in radiopharmaceuticals is increasing. Macrocyclic chelators have been found to have enhanced in vivo stability over acyclic chelators such as ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DTPA). The currently used chelators of choice for labeling copper radionuclides to biological molecules are analogues of TETA (1,4,8,11-tetraazacyclotetradecane-1,4,8,11-tetraacetic acid); however, recent reports have demonstrated evidence of in vivo instability of the radio-Cu(II)-TETA complexes. A new class of structurally reinforced macrocycles, the "cross-bridged" cyclam derivatives, form highly stable complexes with Cu(II) that are resistant to dissociation in strong acid. Here, we evaluate a series of (64)Cu(II) cross-bridged macrocyclic complexes for biological stability and in vivo behavior. The ligands evaluated include the parent ligand, 1,4,8,11-tetraazabicyclo[6.6.2]hexadecane (1), and three 4,11-di-pendant arm derivatives: 4,11-bis(carboxymethyl)-1,4,8,11-tetraazabicyclo[6.6.2]hexadecane (2); 4,11-bis(N,N-diethyl-amidomethyl)-1,4,8,11-tetraazabicyclo[6.6.2]hexadecane (3); and 4,11-bis(amidoethyl)-1,4,8,11-tetraazabicyclo[6.6.2]hexadecane (4). Copper-64 formed complexes with ligands 1-4 in high radiochemical yields. The (64)Cu-2 complex was neutral, while (64)Cu complexes of 1, 3, and 4 were positively charged. All complexes showed no decomposition in rat serum out to 24 h. Biodistribution experiments in Sprague-Dawley rats indicated that (64)Cu-1, -3, and -4 were taken up by the liver and kidney and cleared slowly over 24 h, whereas (64)Cu-2 cleared rapidly from all tissues. The rapid clearance of the (64)Cu-2 complex from the blood and liver, as well as liver metabolism experiments in rats, suggests that it is highly stable in vivo. A bifunctional chelator of 2 is a significant candidate for labeling copper radionuclides to biological molecules for diagnostic imaging and targeted radiotherapy.     

Addressing the community research needs of baccalaureate students

This article describes a course designed to prepare RN-BSN students to assimilate relevant research findings into clinical practice. The course was developed as faculty accepted the challenge of providing didactic content completely online. Guided by two faculty members, two groups of students developed research proposals to respond to community needs identified by a local hospital and a nursing center.     

Activities of cholic acid-derived antimicrobial agents against multidrug-resistant bacteria

Cationic cholic acid derivatives displayed potent and broad-spectrum activity against multidrug-resistant Gram-negative and -positive bacteria. Specific examples were effective permeabilizers of the outer membranes of many strains of multidrug-resistant Gram-negative bacteria and sensitized these to hydrophobic antibiotics. We also prepared a new cholic acid derivative with improved apparent selectivity for prokaryote membranes.