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Biomedical subjects

A Moen

Publications and source records attributed to A Moen.

At least 19 recordsLinked to original sources
PubMed2005

A secondary hybrid zone between diploid Dactylorhiza incarnata ssp. cruenta and allotetraploid D. lapponica (Orchidaceae).

Secondary hybrid zones are not uncommon in Dactylorhiza, but knowledge of ecological and evolutionary consequences of hybridization are scarce. Here, we assess interploidal gene flow and introgression in a hybrid zone between diploid Dactylorhiza incarnata ssp. cruenta (2n = 2x = 40) and its putative allotetraploid derivative D. lapponica (2n = 4x = 80). Photometric quantification of DNA content and morphology confirmed that triploids are abundant in sympatric populations in our study area. Allozyme segregation patterns in D. lapponica supported an allopolyploid origin, although unbalanced genotypes suggested rare pairings between homoeologous chromosomes. Photometric data and chromosome counts suggest backcrossing between the triploid hybrid and D. lapponica, and hence some hybrid fertility. Triploids are morphologically more similar to the tetraploids than the diploids, maybe owing to the hybrid origin of both triploids and tetraploids. The diploids and tetraploids were not more similar in the parapatric populations compared to when they occur in allopatry. This indicates that backcrossing rarely leads to introgression, or alternatively that allopatric populations are not isolated enough to prevent influx of pollen from the other species. Despite some evidence of backcrossing, our study gives few indications that widespread hybridization entails local breakdown of species boundaries. Rather, the hybrid zone may be a transient phenomenon due to intensive mowing, resulting in the opening of habitats and hence bringing the parental species into close contact.

Chimera↗
PubMed2000

Reversal of meconium inhibition of pulmonary surfactant by ferric chloride, copper chloride, and acetic acid.

Meconium inhibits pulmonary surfactant function. We investigated the in vitro effect of meconium on three different commercial surfactants. The dynamic surface properties of these surfactants were evaluated at the concentration of 5 mg/ml with a pulsating bubble system. The inhibitory effect of 2.75 mg/ml meconium was significantly less on Alveofact than on Curosurf and Survanta. Ferric chloride and copper chloride completely reversed the inhibitory effect of meconium. Meconium also prevented effective spreading of surfactant in a Wilhelmy balance system, and this inhibitory effect was counteracted by addition of ferric chloride. Image analysis of Curosurf demonstrated that meconium reduced the total number of microbubbles in 15 light-microscopic fields (4.35 mm(2)) from 1,748 +/- 481 to 180 +/- 166. Ferric chloride restored the number of microbubbles. Addition of ferric chloride or copper chloride to surfactant/meconium lowers pH, and pH adjustment by acetic acid also reversed the inhibitory effect of meconium. Together with the fact that the iron-chelator deferoxamine did not attenuate the effect of ferric chloride this suggests that the observed contrainhibition is caused by lowering of pH, and that meconium inhibition of surfactant is pH-dependent. Lowering pH from 6.2 to 5-5.5 abolished the inhibitory effects of meconium on surfactant. Inhibition of 2.5 mg/ml of Curosurf with plasma could also be reversed by increasing amounts of ferric chloride. We conclude that the inhibitory effect of meconium on surfactant in vitro can be abolished by addition of ferric chloride, copper chloride, or acetic acid.

Acetic Acid↗
PubMed2000

Graduate education in nursing leadership through distance technologies: the Canada-Norway Nursing Connection.

The Canada-Norway Nursing Connection was a collaborative project designed to provide an international educational experience for graduate students in nursing via distance technology. Computer-conferencing and video-teleconferencing were used to address nursing leadership content through case studies. The same technologies were employed to develop the project. The processes of planning and implementing the international linkage are described. Agreement about goals, content, context for online discussion, delivery methods, academic expectations, language support, and logistics was essential. The media proved to be effective for students to gain understandings about nursing leadership, health care, and the forces influencing the nursing profession globally. Insights from the project provided a basis for the development of a model for interactive, international graduate education that will be of value to educators dedicated to helping students gain a global understanding of nursing and health care issues.

Canada↗
PubMed1999

Representing nursing judgements in the electronic health record.

The naming of nursing phenomena and representing the phenomena in a standardized manner suitable for encoding in computer-based systems is a challenge for the nursing profession at the national and the international level. Considerable progress has been made in the development of classification systems for nursing practice. The focus of this article is on language systems developed to represent nursing judgements in computer-based systems, in particular the electronic health record. A review of two current systems and their proposed revisions (North American Nursing Diagnosis Association, NANDA, Taxonomies I and II, and the International Classification for Nursing Practice, ICNP, Alpha and Beta versions), according to the features suggested by the Computer-based Patient Record Institute (CPRI) for classification systems appropriate for implementation in computer-based systems, suggests that the evolving versions extend the current versions in terms of sufficient granularity (depth and level of detail) and atomic and compositional character. However, it is not clear from the literature available to date whether the characteristics that are most closely related to definition of a formal terminology (i.e. clear and non-redundant representation of concepts, syntax and grammar for logical constructions of compositional terms, synonyms and language independence) will be part of the evolving vocabularies. Formal terminology models and related tools have the potential to complement, extend, and refine existing nursing classification systems.

Humans↗
PubMed1998

Oxygen delivery and consumption in surfactant-depleted newborn piglets.

OBJECTIVE: To study the relationship between oxygen (O2) delivery (DO2) and O2 consumption (VO2) in surfactant-depleted newborn piglets. DESIGN: Prospective animal study. SETTING: Hospital surgical research laboratory. SUBJECTS: Twenty-six anesthetized and ventilated newborn piglets. INTERVENTIONS: Twenty of the animals were subjected to repeated saline lung lavages, and then assigned to either the saline group or the L-NAME group. The other six animals without lavage were studied as the control group. Piglets in the L-NAME group and the control group received 3 mg/kg of N(omega)-nitro-L-arginine methyl ester (L-NAME, an inhibitor of NO synthase) i.v.; and those in the saline group received the same volume of saline i.v. MEASUREMENTS AND RESULTS: Cardiac output (CO) was measured and arterial and mixed venous blood gases were analyzed. DO2, O2 extraction ratio (O2ER) and VO2 were calculated. Plasma hypoxanthine was analyzed. In the lung lavaged groups, cardiac index, DO2 and VO2 decreased significantly after L-NAME i.v. but not after saline i.v. Further, the decrease in VO2 in the L-NAME group correlated with the decrease in DO2 (r = 0.83, p < 0.001). In the control group, cardiac index and DO2, but not VO2, decreased significantly after L-NAME i.v. Simultaneously, O2ER increased significantly. Plasma hypoxanthine was not modified by lung lavage but increased after L-NAME i.v. in both the L-NAME and control groups. CONCLUSION: These data suggest that O2 supply dependency is present in surfactant-depleted newborn piglets.

Animals↗
PubMed1998

Acute effects on systemic circulation after intratracheal instillation of Curosurf or Survanta in surfactant-depleted newborn piglets.

Systemic vasodilatation in surfactant-depleted newborn piglets is induced by 200 mg/kg of modified porcine lung surfactant (Curosurf). The aim of this investigation was to study whether this effect is dependent on dose and could further be induced by instillation of a bovine surfactant preparation (Survanta). Twenty-two 3-5-d old piglets were subjected to repeated saline lung lavage and then randomized to one of three groups. Instillation of either Curosurf l00 mg/kg (n=8), Survanta l00 mg/kg (n=7) or Curosurf 200 mg/kg (n=7) was performed through the endotracheal tube. Systemic vascular resistance decreased 7 (+/-4)%, 15 (+/-12)% and 18 (+/-6)% in the three groups, respectively (p < 0.05 in all three groups). A significant difference between the high and low dose Curosurf groups was found (p < 0.05), whereas no significant difference was seen between the Curosurf 100 mg group and the Survanta group. The decrease in vascular resistance was compensated by an increase in cardiac output, resulting in a stable mean arterial blood pressure. In conclusion, both Curosurf and Survanta induce a significant decrease in systemic vascular resistance in surfactant-depleted newborn piglets. A more pronounced effect was observed after 200 mg/kg than after 100mg/kg of Curosurf.

Animals↗
PubMed1997

Introducing a module for laboratory test order entry and reporting of results at a hospital ward: an evaluation study using a multi-method approach.

The medical record system DocuLive EPR was installed at a "typical" ward at the Central Hospital of Akershus. Modules for laboratory order entry and reporting of results were evaluated prospectively using several information sources (hospital information systems, telephone records, user survey, semi-structured interviews with key informants). The main findings are discussed, and the lessons learned from the evaluation project are presented.

Attitude of Health Personnel↗
PubMed1997

Near-infrared monitoring of cerebral tissue oxygen saturation and blood volume in newborn piglets.

Near-infrared spectrophotometry (NIRS) potentially provides a tool for noninvasive tissue oxygenation and blood volume monitoring. Cerebral monitoring could be useful in the prevention of hypoxic ischemic brain injury in newborns. This study sought to validate such NIRS measurements in normoventilated, hypocapnic, and hypoxemic states in the brain of newborn piglets vs. arterial (SaO2) and sagittal sinus blood hemoglobin saturation (SssO2) and blood volume measurements with 99mTc-labeled erythrocytes. NIRS measurements of cerebral blood volume (CBV) were performed with both oxyhemoglobin and indocyanine green as tracers, and changes in CBV were monitored by following the change in the concentration of total hemoglobin (i.e., oxyhemoglobin + deoxyhemoglobin). NIRS CBV measurements did not correlate well with the radioactive measurements. NIRS measurements of oxygenation, however, correlated well with a weighted mean value of SaO2 and SssO2 (r = 0.90; P < 0.0001). Multiple linear regression of the oxygenation index (i.e., oxyhemoglobin - deoxyhemoglobin) on SaO2 and SssO2 suggested that NIRS sees hemoglobin in tissue in a venous-to-arterial ratio of 2:1. Therefore, in this study, NIRS reliably monitored changes in cerebral tissue oxygenation but not in CBV.

Animals↗
PubMed1997

Nursing documentation--beyond the question of structure.

In this paper experiences from a project to improve nursing documentation in a medium size Scandinavian acute care hospital are presented. The project has followed an action research approach to ensure close cooperation in a coordinated fashion over a period of time. In the paper it is explained that structural changes are not enough to ensure higher quality in the nursing documentation. A broader perspective on clinical practice is therefore presented in order to reflect the complexity of clinical practice and varying documentation needs.

Electronic Data Processing↗
PubMed1997

Acute effects on systemic and pulmonary hemodynamics of intratracheal instillation of porcine surfactant or saline in surfactant-depleted newborn piglets.

Surfactant instillation may affect systemic and pulmonary hemodynamics. The aim of this study was to investigate whether this effect is specific to surfactant or if it can be triggered by instillation of the same volume of saline. Piglets 3-5-d-old were subjected to repeated lung lavage using 20 mL/kg 0.9% saline until the partial pressure of arterial O2 was < 10 kPa and partial pressure of arterial CO2 was between 4.0 and 6.0 kPa with fraction of inspired oxygen (FiO2) 1.0 and peak inspiratory pressure 25 cm H2O. Porcine surfactant 200 mg/kg (80 mg/mL) or the same volume of 0.9% saline was instilled into the lungs through a feeding catheter entered through the endotracheal tube. Mean arterial blood pressure, pulmonary artery pressure, and cardiac output were measured continuously. There was a significant decrease in mean arterial blood pressure from 67 (+/- 13) mm Hg to 52 (+/- 18) mm Hg (p < 0.05) 210 s after instillation of surfactant. Systemic vascular resistance decreased from 0.42 (+/- 0.18) to 0.34 (+/- 0.18) mm Hg x mL-1 x min x kg (p < 0.05) from 0 min to 180 s after instillation of surfactant. In the group receiving saline instillations there were no significant changes in mean arterial blood pressure or systemic vascular resistance. A transient but significant increase in mean pulmonary artery pressure was seen 120 s after instillation in both groups with a return to presurfactant level 240 s after instillation. Pulmonary vascular resistance increased transiently and significantly only in the group receiving surfactant. We conclude that porcine surfactant causes a decrease in systemic vascular resistance, resulting in a decrease in mean arterial blood pressure in newborn lung-lavaged piglets not seen after instillation of the same volume of saline.

Animals↗
PubMed1997

Nitric oxide contributes to surfactant-induced vasodilation in surfactant-depleted newborn piglets.

To investigate whether nitric oxide (NO) is involved in surfactant-induced systemic and pulmonary vasodilatation in newborn piglets with surfactant deficiency, 2-6-d-old piglets were subjected to repeated saline lung lavages. They were then randomly assigned to one of two groups (seven in each group): the N(omega)-nitro-L-arginine methyl ester (L-NAME) group received 3 mg/kg L-NAME i.v. 45 min before endotracheal instillation of 200 mg/kg porcine surfactant; the saline group received saline i.v. at the same time point, and instillation of 200 mg/kg surfactant. Mean arterial blood pressure, systemic vascular resistance, pulmonary arterial pressure, and pulmonary vascular resistance increased significantly after injection of L-NAME (all p < 0.01), whereas the cardiac index decreased significantly (p < 0.05). Saline injection did not change any variable. Significant decreases in mean arterial blood pressure (from a mean +/- SD of 66 +/- 10 to 53 +/- 9 mm Hg, p < 0.01), pulmonary arterial pressure (from 29 +/- 6 to 23 +/- 6 mm Hg, p < 0.01), and systemic vascular resistance (from 0.40 +/- 0.13 to 0.33 +/- 0.12 mm Hg/mL/min/kg, p < 0.05) were observed only in the saline group after surfactant instillation, whereas the decrease in pulmonary vascular resistance was not significant after surfactant instillation (p = 0.06). In contrast to the saline group, these variables were not modified in the L-NAME group after surfactant instillation. We conclude that the vasodilatory effect of porcine surfactant instillation in newborn piglets with surfactant deficiency is associated with activation of NO synthase.

Animals↗
PubMed1996

Hemodynamics and tissue blood flow after porcine surfactant replacement in surfactant-depleted newborn piglets.

In 22 newborn piglets we studied the effect of hypovolemia or hypoxemia on hemodynamics and regional blood flow after instillation of porcine surfactant. Surfactant deficiency was obtained by repeated lung lavage, and blood flow measurements were carried out using radioactive microspheres. Three groups of piglets were studied, controls (n = 8), hypovolemia (n = 7), and hypoxemia (n = 7). Three to five minutes after instillation of surfactant, mean arterial blood pressure decreased significantly in all three groups with a mean decrease (+/- SD) of 31(+/- 12), 33(+/- 9), and 29(+/- 9) mm Hg, respectively (p < 0.01 in all three groups). Systemic vascular resistance decreased significantly in all three groups immediately after surfactant instillation (p < 0.01) and returned to presurfactant level after 60 min. Blood flow did not change after surfactant instillation in any of the three groups, in neither skin, muscle, pancreas, brain, nor retina. In liver, kidney, intestine, and choroidea there was a decrease in blood flow immediately after instillation with return to presur-factant levels within 60 min. Hypoxemia or hypovolemia before surfactant instillation did not increase the hemodynamic instability. The decrease in mean arterial blood pressure was caused by a vasodilation and not by a reduced cardiac output.

Animals↗
PubMed1995

Release of xanthine oxidase to the systemic circulation during resuscitation from severe hypoxemia in newborn pigs.

Xanthine oxidase may contribute to oxygen free radical formation during reoxygenation after hypoxia, but in humans the enzyme is present in substantial amounts only in the liver and intestine. We developed a sensitive assay for xanthine oxidase using 14C-xanthine as substrate and investigated whether xanthine oxidase was released into the systemic circulation when 19 newborn pigs were resuscitated after severe hypoxemia. In five piglets plasma xanthine oxidase concentrations increased from undetectable levels to a median value of 8 (range 4-18) microU/ml after 30 min of reoxygenation. In these pigs serum aspartate aminotransferase increased from 45 to 148 U/l, while alanine aminotransferase was unchanged (28-31 U/l). The release of xanthine oxidase did not seem to correlate with the severity of the histological brain damage after 4 days. We conclude that only low levels of xanthine oxidase are released to the systemic circulation after severe hypoxemia in newborn pigs.

Alanine Transaminase↗
PubMed1992

[Deaths caused by antidepressive agents and neuroleptics. Risk groups illustrated by a forensic material].

At the Institute of Forensic Medicine, University of Oslo, legal autopsy was performed on 153 persons who died from poisoning by neuroleptics and/or antidepressants from 1986 to 1989. In one third of the cases, only neuroleptics were found at autopsy, and in little less than half of these cases the post mortem blood concentrations were considered rather low in relation to the fatal outcome. A larger proportion of alcohol abusers were found in the group with low post mortem concentrations of neuroleptics than in the rest of the material. This group contained mainly men and was further characterized by a high proportion of unintentional deaths. In the light of these facts the authors speculate whether neuroleptics represent increased risk of sudden death among alcohol abusers. The deaths due to an overdose of antidepressants were mostly suicides, and involved high post mortem blood concentrations of the drugs.

Adolescent↗
PubMed1992

Shifting the financial burden: the VA ambulatory care discharge policy.

The Department of Veterans Affairs is a primary source of health care services for many of the nation's uninsured and underinsured. Changes in congressionally mandated eligibility criteria and limited increases in appropriations have forced the Department to adopt a policy of discharging chronic but stable outpatients who have been treated for non-service-connected health conditions. Survey data from one VA medical center suggest that many, but not all, of those discharged: 1) have either Medicare or private insurance coverage; 2) have not sought or found alternative physician services in their local communities; 3) have discontinued taking previously prescribed medications; 4) report worsened health status since discharge; and, 5) have been hospitalized. In general, discharged patients from the lowest income group report the greatest financial access barriers. Preliminary analyses of the discharge policy suggest the potential for decreased access to needed medical services due to financial factors and cost-shifting from the VA to patients and other federal, state and local payers and providers.

Chronic Disease↗
PubMed1992

Hypoxemia and reoxygenation with 21% or 100% oxygen in newborn pigs: changes in blood pressure, base deficit, and hypoxanthine and brain morphology.

To study whether room air is as effective as 100% O2 in resuscitation after hypoxia, hypoxemia (PaO2 2.3-4.3 kPa) was induced in newborn pigs (2-5 d old) by ventilation with 8% O2 in nitrogen. When systolic blood pressure had fallen to 20 mm Hg, animals were randomly reoxygenated with either 21% O2 (group 1, n = 9) or 100% O2 (group 2, n = 11) for 20 min followed by 21% O2 in both groups. Controls (group 3, n = 5) were ventilated with 21% O2 throughout the experiment. Base deficit peaked at 31 +/- 5 mmol/L (mean +/- SD) for both hypoxic groups at 5 min of reoxygenation and then normalized over the following 3 h. There were no statistically significant differences between the two groups during reoxygenation concerning blood pressure, heart rate, base deficit, or plasma hypoxanthine. Hypoxanthine peaked at 165 +/- 40 and 143 +/- 42 mumol/L in group 1 and 2 (NS), respectively, and was eliminated monoexponentially in both groups with an initial half-life for excess hypoxanthine of 48 +/- 21 and 51 +/- 27 min (NS), respectively. Blinded pathologic examination of cerebral cortex, cerebellum, and hippocampus after 4 d showed no statistically significant differences with regard to brain damage. We conclude that 21% O2 is as effective as 100% O2 for normalizing blood pressure, heart rate, base deficit, and plasma hypoxanthine after severe neonatal hypoxemia in piglets and that the extent of the hypoxic brain damage is similar in the two groups.

Animals↗