bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cardiovascular responses to circulating catecholamines in normal pregnancy and in pregnancy‐induced hypertension
Authors: Nisell Henry , Hjemdahl Paul , Linde Birgitta 
Published: April 2008

Summary. Patients with pregnancy‐induced hypertension (PIH) and healthy pregnant and non‐pregnant women were compared with regard to cardiovascular responses to i.v. infusions of noradrenaline (NA) and adrenaline (ADR). This resulted in physiologically relevant concentrations in arterial plasma (maximally 10 nmol/litre for NA and 6 nmol/litre for ADR). Non‐pregnant women responded to NA with concentration‐dependent increases in blood‐pressure, which were caused by peripheral vasoconstriction, as systemic vascular resistance (SVR) was increased by 21%. Cardiac output was reduced by 6%. ADR caused concentration‐dependent decreases in SVR (to values 36% below basal) and calf vascular resistance (CVR), as well as increases in cardiac output. Healthy pregnant women responded to NA with similar increases in blood‐pressure, but this was due to stroke volume‐dependent increases in cardiac output (11%) and not due to vasoconstriction. ADR‐induced vasodilatation was attenuated in this group. Cardiac responses to ADR were unaffected by pregnancy. PIH patients demonstrated an enhanced systolic blood‐pressure response to NA (19% increase vs 7–8% in the other groups) due to the combined effects of vasoconstriction (11% increase in SVR) and an essentially unchanged cardiac output. ADR‐induced decreases in CVR and diastolic blood‐pressure were similar to those found in the non‐pregnant group. Increases in heart rate were less pronounced, but cardiac output increased as normal.These results indicate that normal pregnancy is associated with attenuated vascular responses to circulating catecholamines. PIH patients do not seem to have undergone this normal adaptation of the vascular system to pregnancy.
Spectral analysis with digital presentation of C‐W Doppler signals in the evaluation of carotid stenosis
Authors: Jungquist G. , Olivecrona H. , Kendrup I. , Bornmyr S. , Norrving B. , Takolander R. , Lindell S. E. 
Published: April 2008

Summary. Using a continuous‐wave ultrasound Doppler system with spectral analysis (FFT) and digital processing and presentation, the Doppler shift characteristics of the carotid arteries were studied in 40 healthy subjects (20 men and 20 women; average age 69 years). The reference values, thus obtained, were applied to the analysis of sonograms from 46 carotid arteries, which were also studied angiographically. Stenoses which reduced the diameter of the internal carotid artery by more than 30% could be identified with a sensitivity of 97% and a specificity of 100%. The results extend previous experience that spectral analysis improves the usefulness of the ultrasound Doppler system in the evaluation of carotid artery disease. The addition of digital processing and presentation of the Doppler shift characteristics increases the diagnostic precision and provides a permanent record.The importance of well‐trained sonographers and adequate reference values is emphasized.
Relationships between skin temperature and perfusion in the arm and leg
Authors: Stoner H. B. , Barker P. , Riding G. S. G. , Hazlehurst D. E. , Taylor L. , Marcuson R. W. 
Published: April 2008

Summary. Relationships between skin temperature (Tsk) and perfusion have been studied to provide a basis for the use of Tsk in the non‐invasive assessment of limb circulation in peripheral vascular disease.Raising the ambient temperature (Ta) from 20 to 30°C increased the perfusion of the glabrous skin of the hands and feet without changing that of the skin of the forearm or calf. On a fractional basis the response in the hand and foot was the same. Tsk was higher in the arms than the legs and in the proximal than distal parts of the limbs. A fall in Tsk was often seen when Ta rose from 20 to 25°C and was attributed to counter‐current cooling. Subsequently Tsk rose even in regions where there was no increase in skin perfusion. Tsk can only be related to its perfusion in the fingers, palm and toes. Forearm Tsk was related to the perfusion of the digits. This relationship implies a link with the arterial inflow to the limb which determines the size of its thermal core. Heat conduction from the core seemed important for the skin of areas like the forearm and calf where the constant, low perfusion limited the amount of heat which could be transported to it directly by the blood.The importance of conduction was supported by studies, at Ta 20°C, on subjects during calf muscle exercise and on patients with arterio‐venous fistulae. Here an increase in the arterial inflow to the limb was associated with a rise in Tsk of the forearm/calf unrelated to the perfusion of its skin.
Cardiac contractility, central haemodynamics and blood pressure regulation during semistarvation
Authors: Stokholm K. H. , Breum L. , Astrup A. 
Published: April 2008

SUMMARYEight obese patients were studied before and after 2 weeks of treatment by a very‐low‐calorie diet (VLCD). Cardiac output and central blood volume (pulmonary blood volume and left atrial volume) were determined by indicator dilution (125I‐albumin) and radionuclide angiocardiography (first pass and equilibrium technique by [99Tcm]red blood cells). Cardiac output decreased concomitantly with the reduction in oxygen uptake as the calculated systemic arteriovenous difference of oxygen was unaltered. There were no significant decreases in left ventricular contractility indices, i.e. the ejection fraction, the peak ejection rate and changes in end‐systolic volume. Also the diastolic function evaluated by the peak filling rate remained normal. Furthermore, no sign of backward failure could be demonstrated since the central blood volume was not significantly increased. Both systolic and diastolic blood pressure (BP) declined. The fall in BP was caused by the reduction in cardiac output as the total peripheral resistance was unchanged. Finally, the decline in total blood volume was not significant. These findings together with a reduction in heart rate indicated that a reduced sympathetic tone via increased capacitance of the venous bed was the main operator of a reduced venous return. Thus, the haemodynamic alterations in obese patients during short‐term semistarvation may be caused by the fall in oxygen uptake and produced mainly by changes in the sympathetic tone.
Blood volume distribution during head‐up tilt induced central hypovolaemia in man
Authors: MatZen S. , Perko G. , Groth S. , Friedman D. B. , Secher N. H. 
Published: April 2008

Summary. We evaluated regional electrical impedance (Z°) at 2.5 and 100 kHz to separate intra‐ and extracellular fluid changes and correlated Z° over the thorax (TI) to relative changes in the central blood volume (CBV) induced by head‐up tilt. In nine experiments head‐up tilt resulted in normotensive central hypovolaemia associated with a 3·7 & 0·4 Ohm (mean f SE) increase in TI100 kHz after 60 min. In 24 experiments presyncopal symptoms were induced after 43±2 min, when TI100kHz had increased 4·2 ± 0·2 Ohm. Head‐up tilt instantly decreased the activity of technetium labelled erythrocytes (99Tcm) over the thorax by 24 ± 2%, and increased 99Tcm over the thigh by 68±10% (P< 0·01, n = 8) with no further changes during the sustained tilt. Haematocrite increased during head‐up tilt from 43·1 ± 0·3 to 47·9 ± 0·6% (P<0·01, n= 8). Accordingly, the increase in TI (6·3 ± 0·6 vs. 4·5 0·4 Ohm, n= 6) and the decrease in Z° through one leg (7·2 ± 1·2 vs. 2·8 ± 0·5 Ohm, n= 6) at 2·5 kHz was more pronounced than at 100 kHz. Also the changes in TI were correlated to CBV as calculated from 99Tcm and haematocrite (r = 0.90, P < 0·01). The results suggest that:(1) Hypovolaemic shock is associated with a faster increase of TI than normotensive head‐up tilt.(2) Head‐up tilt is characterized by an initial decrease in CBV followed by a further decrease in plasma volume, which eventually leads to hypovolaemic shock.(3) Blood volume changes during head‐up tilt are reflected in regional Z°.
Effect of acute acidosis and alkalosis on leucine kinetics in man
Authors: Straumann E. , Keller U. , Kury D. , Bloesch D. , Thélin A. , Arnaud M. J. , Stauffacher W. 
Published: April 2008

Summary. The effects of acute pH changes on whole body leucine kinetics (1‐13C‐leucine infusion technique) were determined in normal subjects. Plasma insulin, glucagon, and growth hormone concentrations were kept constant by somatostatin and replacement infusions of the three hormones.When acidosis was produced by ingestion of NH4CI (4 mmol kg‐1 p. os; n = 8) arterialized pH decreased within 3 h from 7.39±0.01 to 7.31 ±0.01 (P<0.001) and leucine plasma appearance increased by 0.13 ±0.04 μmol kg‐1 min‐1 (P<0.02); in contrast, when alkalosis was produced by intravenous infusion of 4 mmol kg‐1 NaHCO3 (n= 1, pH 7.47 ±0.01), leucine plasma appearance decreased by ‐0.09 ± 0.04 (xmol kg‐1 min‐1 (P<0.01 vs. acidosis). Whole body leucine flux also increased during acidosis compared to alkalosis (P<0.05), suggesting an increase in whole body protein breakdown during acidosis. Apparent leucine oxidation increased during acidosis compared to alkalosis (P=0.05). Net forearm leucine exchange remained unaffected by acute pH changes.Plasma FFA concentrations decreased during acidosis by ‐107 ±67 μmol l‐1 (P<0.05) and plasma glucose increased by 1.90±0.25 mmol l‐1 (P<0.02); in contrast, alkalosis resulted in an increase in plasma FFA by 83 ± 40 (μmol 1‐1 (P<0.02; P<0.01 vs. acidosis), suggesting an increase in lipolysis; plasma glucose decreased compared to acidosis (P<0.01).The data demonstrate that acute metabolic acidosis and alkalosis, as they occur in clinical conditions, influence protein breakdown, and in the opposite direction, lipolysis.
Haemodynamic and neurohumoral effects of cold pressor test in severe heart failure
Authors: Westheim A. , Os I. , Thaulow E. , Kjeldsen S. E. , Eritsland J. , Eide I. K. 
Published: April 2008

Summary.The effect of a cold pressor test (CPT) on haemodynamics in relation to general and regional sympathetic activity and arginin vasopressin (AVP), was studied in eleven patients with severe congestive heart failure (CHF). Compared to an age‐matched control group (C), resting arterial plasma noradrenaline (NA) (419 ±77 vs. 182 ±15 pg ml‐1), and adrenaline (A) (142 ±28 vs 54 ±10 pg ml‐1) were higher (P<0.05) in CHF. AVP showed no significant difference (14±4 vs. 9±4 pg ml‐1). During CPT systolic and diastolic blood pressure and systemic vascular resistance increased (P<0.01), as did NA (δ 114±39 pg ml‐1, P<0.01), A (δ 33 ± 10 pg ml, P<0.01) and heart rate (δ 10 beats min‐1, P<0.01). The myocardial v‐a difference of NA decreased (P<0.05), but was unchanged across the renal vascular bed during CPT. The a‐v difference of NA in the hepatic vascular bed, and fractional extraction of A in the coronary sinus, renal and hepatic vascular beds remained unchanged during CPT. AVP did not change significantly and no change in cardiac index or left ventricular filling pressure was observed during CPT.These data suggest that despite an increased activation of the sympathetic nervous system at rest, a further increase in blood pressure and catecholamines took place during CPT. Thus, the effect of a CPT which activates the central sympathetic system seems not to be altered in patients with severe CHF.
Effects of mental state on heart rate and blood pressure variability in men and women
Authors: Madden K. , Savard G. K. 
Published: April 2008

Summary. The effect of different mental states on autonomic modulation of the cardiovascular system was assessed in healthy, normotensive men (n=18) and women (n=12). Heart rate variability (HRV), systolic blood pressure variability (BPV) and arterial baroreflex function were assessed during 4 tests at rest ((10 min+5 min recovery)×4):

Control (spontaneous breathing, (SB)
Mental distraction (SB+word puzzle)
Conscious control of breathing (paced at SB rate) and
Mental stress (SB+computer quiz).

There were no significant gender differences in the responses to the interventions in terms of arterial (spontaneous) baroreflex (SPBX) control of HR, and indices of time and frequency domains of HRV and BPV, with the exception of the sympathetic indicator of HRV (low frequency power/total power; P<0.01) which was lower in women during control and mental stress tests. Conscious control of breathing at SB did not alter HRV, BPV or SPBX in either men or women. Mental distraction and mental stress led to decreases in indices of time and frequency domains of HRV and BPV in all subjects, as well as increases in HR during distraction and in systolic BP during stress. These findings suggest that in studies of cardiovascular control:

Paced breathing at SB can be used for individuals with irregular breathing patterns
The extent of mental stress achieved is intervention‐specific and for the most part, independent of gender and
Resting assessment of HRV, BPV and SPBX can be made by having subjects sit quietly without interventions in a controlled laboratory setting.
Multimethod Evaluation of Health Policy Change: An Application to Medicaid Managed Care in a Rural State
Authors: Waitzkin Howard , Schillaci Michael , Willging Cathleen E. 
Published: April 2008

Objective. To answer questions about the impacts of Medicaid managed care (MMC) at the individual, organizational/community, and population levels of analysis.Data Sources/Study Setting. Multimethod approach to study MMC in New Mexico, a rural state with challenging access barriers.Study Design. Individual level: surveys to assess barriers to care, access, utilization, and satisfaction. Organizational/community level: ethnography to determine changes experienced by safety net institutions and local communities. Population level: analysis of secondary databases to examine trends in preventable adverse sentinel events.Data Collection/Extraction Methods. Survey: multivariate statistical methods, including factor analysis and logistic regression. Ethnography: iterative coding and triangulation to assess documents, field observations, and in‐depth interviews. Secondary databases: plots of sentinel events over time.Principal Findings. The survey component revealed no consistent changes after MMC, relatively favorable experiences for Medicaid patients, and persisting access barriers for the uninsured. In the ethnographic component, safety net institutions experienced increased workload and financial stress; mental health services declined sharply. Immunization rate, as an important sentinel event, deteriorated.Conclusions. MMC exerted greater effects on safety net providers than on individuals and did not address problems of the uninsured. A multimethod approach can facilitate evaluation of change in health policy.
Effect of Eliminating Behavioral Health Benefits for Selected Medicaid Enrollees
Authors: McConnell K. John , Wallace Neal T. , Gallia Charles A. , Smith Jeanene A. 
Published: April 2008

Objective. To determine the extent to which the elimination of behavioral health benefits for selected beneficiaries of Oregon's Medicaid program affected general medical expenditures among enrollees using outpatient mental health and substance abuse treatment services.Data Source/Study Setting. Twelve months of claims before and 12 months following a 2003 policy change, which included the elimination of the behavioral health benefit for selected Oregon Medicaid enrollees.Study Design. We use a difference‐in‐differences approach to estimate the change in general medical expenditures following the 2003 policy change. We compare two methodological approaches: regression with propensity score weighting; and one‐to‐one covariate matching.Principal Findings. Enrollees who had accessed the substance abuse treatment benefit demonstrated substantial and statistically significant increases in expenditures. Individuals who accessed the outpatient mental health benefit demonstrated a decrease or no change in expenditures, depending on model specification.Conclusions. Elimination of the substance abuse benefit led to increased medical expenditures, although this offset was still smaller than the total cost of the benefit. In contrast, individuals who accessed the outpatient mental health benefit did not exhibit a similar increase, although these individuals did not include a portion of the Medicaid population with severe mental illnesses.
Seed Market Privatisation and Farmers’ Access to Crop Technologies: The Case of Hybrid Pearl Millet Adoption in India
Authors: Matuschke Ira , Qaim Matin 
Published: April 2008

AbstractIn India, pearl millet is a typical subsistence crop. Nonetheless, use of hybrid seeds is widespread. The first pearl millet hybrids were introduced in 1965 by the public sector. Yet, starting in the late 1980s, market liberalisation led to an increasing role of private companies in seed development and distribution. Although several studies showed that proprietary pearl millet hybrids are more productive than public hybrids and open‐pollinated varieties, the impacts of privatisation on farmers’ technology access and overall innovation rates are not yet well understood. This paper analyses the dynamics of adoption using duration models and farm survey data collected in the state of Maharashtra. The results show that education, short distances to main information sources and good market infrastructure speeded up the adoption of pearl millet hybrids. Likewise, the increasing role of private seed companies had a positive and accelerating effect on technology diffusion in the small farm sector.
Hepatitis B Virus Infection and the Dialysis Patient
Authors: Fabrizi Fabrizio , Messa Piergiorgio , Martin Paul 
Published: April 2008

AbstractPrevention of nosocomial transmission of hepatitis B virus (HBV) has been a signal achievement in the management of chronic kidney disease. The rate of serum hepatitis B surface antigen (HBsAg) seropositivity in patients on maintenance hemodialysis in the developed world is currently low (0–10%) but outbreaks of acute HBV infection continue to occur in this setting. The prevalence of HBV infection within dialysis units in developing countries appears higher (2–20%) based on relatively few reports. Although data are limited, HBV infection in dialysis population diminishes survival; HBV viral load in HBsAg‐positive dialysis patients is reportedly low and stable over time. Updated recommendations for the management of HBsAg chronic carriers on maintenance dialysis have been issued. No rigorously controlled treatment trials for treatment of hepatitis B with either interferon or lamivudine therapy in dialysis patients are currently available.
Determining Care Management Activities Associated with Mastery and Relationship Strain for Dementia Caregivers
Authors: Connor Karen I. , McNeese‐Smith Donna K. , Vickrey Barbara G. , Van Servellen Gwen M. , Chang Betty L. , Lee Martin L. , Vassar Stefanie D. , Chodosh Joshua 
Published: April 2008

OBJECTIVES: To identify specific care management activities within a dementia care management intervention that are associated with 18‐month change in caregiver mastery and relationship strain.DESIGN: Exploratory analysis, using secondary data (care management processes and caregiver outcomes) from the intervention arm of a clinic‐level randomized, controlled trial of a dementia care management quality improvement program.SETTING: Nine primary care clinics in three managed care and fee‐for‐service southern California healthcare organizations.PARTICIPANTS: Two hundred thirty‐eight pairs: individuals with dementia and their informal, nonprofessional caregivers.MEASUREMENTS: Care management activity types extracted from an electronic database were used as predictors of caregiver mastery and relationship strain, which were measured through mailed surveys. Multivariable linear regression models were used to predict caregiver mastery and relationship strain.RESULTS: For each care manager home environment assessment, caregiver mastery increased 4 points (range 0–100, mean±standard deviation 57.1±26.6, 95% confidence interval (CI)=2.4–5.7; P=.001) between baseline and 18 months. For every action linking caregivers to community agencies for nonspecific needs, caregiver mastery decreased 6.2 points (95% CI=−8.5 to −3.9; P<.001). No other care management activities were significantly associated with this outcome, and no specific activities were associated with a change in caregiver relationship strain.CONCLUSION: Home assessments for specific needs of caregivers and persons with dementia are associated with improvements in caregivers' sense of mastery. Future work is needed to determine whether this increase is sustained over time and decreases the need for institutionalization.
The Confusion Assessment Method: A Systematic Review of Current Usage
Authors: Wei Leslie A. , Fearing Michael A. , Sternberg Eliezer J. , Inouye Sharon K. 
Published: April 2008

OBJECTIVES: To examine the psychometric properties, adaptations, translations, and applications of the Confusion Assessment Method (CAM), a widely used instrument and diagnostic algorithm for identification of delirium.DESIGN: Systematic literature review.SETTING: Not applicable.MEASUREMENTS: Electronic searches of PubMED, EMBASE, PsychINFO, CINAHL, Ageline, and Google Scholar, augmented by reviews of reference listings, were conducted to identify original English‐language articles using the CAM from January 1, 1991, to December 31, 2006. Two reviewers independently abstracted key information from each article.PARTICIPANTS: Not applicable.RESULTS: Of 239 original articles, 10 (4%) were categorized as validation studies, 16 (7%) as adaptations, 12 (5%) as translations, and 222 (93%) as applications. Validation studies evaluated performance of the CAM against a reference standard. Results were combined across seven high‐quality studies (N=1,071), demonstrating an overall sensitivity of 94% (95% confidence interval (CI)=91–97%) and specificity of 89% (95% CI=85–94%). The CAM has been adapted for use in the intensive care unit, emergency, and institutional settings and for scoring severity and subsyndromal delirium. The CAM has been translated into 10 languages where published articles are available. In application studies, CAM‐rated delirium is most commonly used as a risk factor or outcome but also as an intervention or reference standard.CONCLUSION: The CAM has helped to improve identification of delirium in clinical and research settings. To optimize performance, the CAM should be scored based on observations made during formal cognitive testing, and training is recommended. Future action is needed to optimize use of the CAM and to improve the recognition and management of delirium.