bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of exercise training on cardiac baroreflex sensitivity in patients with COPD
Authors: Costes F. , Roche F. , Pichot V. , Vergnon J.M. , Garet M. , Barthelemy J-C.
Published: February 2004

Decreased spontaneous cardiac baroreflex sensitivity (BRS), which could lead to the onset of cardiovascular events, has been demonstrated in chronic obstructive pulmonary disease patients. This study evaluates the effects of an exercise training programme on BRS.

Twenty-one chronic obstructive pulmonary disease patients (mean±sd age 62±9 yrs; forced expiratory volume in one second 43.6±18.1% of the predicted value) with mild hypoxaemia (arterial oxygen tension 8.96±1.18 kPa) were compared to 18 healthy age-matched subjects. BRS was calculated as the slope of the baroreflex sequences between spontaneous changes in systolic blood pressure and subsequent consecutive relative risk deviation length, and was measured in the supine position and following head-up tilt for sympathetic stimulation.

Pulmonary function test results and blood gas levels, measured only in patients, did not change after the training programme. Exercise training increased the maximal sustained workload (16.5%) and peak oxygen consumption (20.5%). Before training, BRS was lower in patients than in controls (2.7±1.5versus7.8±4.9 ms·mmHg−1) and tilting induced a smaller reduction in BRS (13versus34%). After training, BRS increased to 3.4±2.6 ms·mmHg−1in patients but remained lower than in controls. The response to the tilt test remained unchanged after training.

It is concluded that, in chronic obstructive pulmonary disease patients, exercise training is associated with a gain in spontaneous baroreflex sensitivity, reflecting cardiovascular benefits.
Follow-up of 452 totally implantable vascular devices in cystic fibrosis patients
Authors: Munck A. , Malbezin S. , Bloch J. , Gerardin M. , Lebourgeois M. , Derelle J. , Bremont F. , Sermet I. , Munck M-R. , Navarro J.
Published: February 2004

The use and complications of totally implantable vascular access devices (TIVADs) were examined during multiple courses of antibiotics in cystic fibrosis (CF) patients.

This retrospective study involved 36 CF centres. Risk factors for removal and septicaemia were sought by survival analysis of censored data. Multivariate Cox models were constructed with removal or septicaemia as the event and the characteristics of TIVADs as explanatory variables.

TIVADs (n=452) were implanted in 315 patients. The mean functional time per device was 32±25 months. Long-term complications occurred with 188 devices (42%); they consisted mainly of occlusion (21%, requiring removal in 77%), infection (9.3%, requiring removal in 85%; septicaemia in 7.3%; rate 0.3 per 1,000 days, Candida in 66%), and vascular thrombosis (4.7%, removal in 58%). Multivariate survival analysis showed that removal, whatever the reason, was associated with polyurethane (versussilicone) and routine use of the device for blood sampling (versusnever). No risk factors, including heparin lock, were identified for septicaemia or for removal for obstruction.

Totally implantable venous access devices appear to be safe and reliable for long-term intermittent venous access. Although retrospective, this study suggests that the characteristics of the material and blood sampling are risk factors for removal.
Low incidence of pulmonary complications following nonmyeloablative stem cell transplantation
Authors: Nusair S. , Breuer R. , Shapira M.Y. , Berkman N. , Or R.
Published: February 2004

Bone marrow transplantation is associated with pulmonary opportunistic infections and immune-mediated pulmonary processes such as idiopathic pneumonia syndrome and bronchiolitis obliterans. The aim of the present study was to test the hypothesis that nonmyeloablative stem cell transplantation (NST) has less adverse effects on the lungs.

A review was undertaken of the pulmonary complications occurring in 53 patients with various haematological malignancies, some of whom were considered high-risk patients with chemoresistant disease, who underwent fludarabine-based irradiation-free conditioning for NST performed between March 1996 and October 1998. All data related to transplant procedure, disease outcome, graft-versus-host disease (GVHD), chest imaging, microbial cultures and lung biopsies, were retrieved from information collected prospectively at the time of transplantation.

The median follow-up period after transplantation was 45 months, with 35 patients surviving >100 days. Approximately half of the patients displayed some form of GVHD, with 11% developing severe chronic GVHD. In 17 (32%) patients, the lungs were somehow adversely affected. Only two (3.8%) patients developed a clinical picture consistent with idiopathic pneumonia syndrome and none developed diffuse alveolar haemorrhage or bronchiolitis obliterans.

Dose-reduced conditioning is associated with a low rate of pulmonary toxicity and side-effects. These findings may extend understanding of significant immune-mediated complications occurring after bone marrow transplantation.
Prediction equations for normal and low lung function from the Health Survey for England
Authors: Falaschetti E. , Laiho J. , Primatesta P. , Purdon S.
Published: February 2004

The aim of this study was to derive new spirometric reference equations for the English population, using the 1995/1996 Health Survey for England, a large nationally representative cross-sectional study.

The measurements used were the forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) of a sample of 6,053 “healthy” (nonsmokers with no reported diagnosis of asthma or respiratory symptoms) White people aged ≥16 yrs. Multiple regression analysis, with age and height as predictors, was carried out to estimate prediction equations for mean FEV1, FVC and FEV1/FVC, separately for males and females. A method based on smoothing multiple estimates of the fifth percentiles of residuals was used to derive prediction equations for the lower limit of normal lung function.

The new equations fit the current English adult population considerably better than the European Coal and Steel Community equations, and the proportions of people with “low” (below the fifth percentile) lung function are closer to those expected throughout the whole adult age range (16 to >75 yrs). For the age ranges the studies share in common, the new equations give estimates close to those derived from other nonlinear equations in recent studies.

It is, therefore, suggested that these newly developed prediction equations be used for the White English population in both epidemiological studies and clinical practice.
Aerosol cyclosporin therapy in lung transplant recipients with bronchiolitis obliterans
Authors: Iacono A.T. , Corcoran T.E. , Griffith B.P. , Grgurich W.F. , Smith D.A. , Zeevi A. , Smaldone G.C. , McCurry K.R. , Johnson B.A. , Dauber J.H.
Published: February 2004

The majority of patients who develop bronchiolitis obliterans, after lung transplantation, die within 2–3 yrs after onset since treatment with conventional immunosuppression is typically ineffective. A case/control study was conducted in lung transplant recipients with biopsy-documented bronchiolitis obliterans to determine whether aerosol cyclosporin use contributed to increased survival.

The cases comprised 39 transplant recipients who received open-label aerosol cyclosporin treatment in addition to conventional immunosuppression. The controls were transplant recipients treated with conventional immunosuppression alone. There were 51 controls from the University of Pittsburgh Medical Center and 100 from a large multicentric database (Novartis Lung Transplant Database).

Forced expiratory volume in one second expressed as a percentage of the predicted value was an independent predictor of survival in all patients with bronchiolitis obliterans. Cox proportional-hazards analysis revealed a survival advantage for aerosol cyclosporin cases compared to the Pittsburgh control group. A survival advantage was also seen when comparing study cases to multicentric controls.

Aerosol cyclosporin, given with conventional immunosuppression to lung transplant recipients with bronchiolitis obliterans, provides a survival advantage over conventional therapy alone.
Preservation of post-transplant lung function with aerosol cyclosporin
Authors: Corcoran T.E. , Smaldone G.C. , Dauber J.H. , Smith D.A. , McCurry K.R. , Burckart G.J. , Zeevi A. , Griffith B.P. , Iacono A.T.
Published: February 2004

Post-lung transplant use of aerosol cyclosporin (ACsA) is considered by examining the relationship between deposited aerosol dose and effect.

In a sub-study of placebo controlled trials of ACsA as a rejection prophylaxis, 15 drug subjects received aerosol dose quantification tests to gage their ability to effectively deposit the nebulised drug in their transplanted lung(s). A total of seven placebo subjects received mock deposition tests. The deposited doses and mock doses were compared to changes in the forced expiratory volume in one second, at six time points during the 2‐yr trial period (ACsA was started within 6 weeks post-transplant).

Linear relationships were demonstrated between deposited dose and improvement in lung function in the drug subjects at all intervals. Mock dose data from placebo subjects did not demonstrate similar correlation. Based on these results, subjects were grouped by dose and compared. Subjects depositing ≥5 mg of the drug in the periphery of their transplant(s) had improving pulmonary function on average. Low-dose and placebo subjects demonstrated declines, more A2–A4 rejection events in the latter portion of the trial, and more chronic rejection beyond the end of the trial.

A dose-to-effect relationship is demonstrated for aerosol cyclosporin in terms of pulmonary function and biopsy proven rejection.
Central nervous system metastases of a pulmonary epitheloid haemangioendothelioma
Authors: Díaz R. , Segura Á. , Calderero V. , Cervera I. , Aparicio J. , Jordá M.V. , Pellín L.
Published: February 2004

The case of a 55‐yr-old male with a right pleural effusion and multiple bilateral nodules is reported. A diagnostic thoracothomy was necessary to obtain a definitive histological diagnosis.

During the postoperative course, the subject's neurological condition deteriorated and multiple cerebral mass lesions were discovered. The pathological analysis of both lung and cerebral tumours revealed an atypical endothelial cell proliferation; vascular immunohistochemical markers, such as factor VIII and CD34, were strongly positive. His general condition remained poor and the patient died 18 months after the initial diagnosis.

The final diagnosis was pulmonary epitheloid haemangioendothelioma with synchronous central nervous system dissemination, the first time the authors believe that association has been reported. Little is known of the prognosis and treatment of these tumours, due to their rarity. Negative prognostic factors appear to be the presence of symptoms, pleural effusion or multifocal presentations. Treatment should include surgical resection if possible; chemotherapy appears to have little effect. Watchful waiting is an acceptable option, especially in asymptomatic patients.
Inhaled steroids and mortality in COPD: bias from unaccounted immortal time
Authors: Suissa S.
Published: February 2004

A recent observational study, which suggested that inhaled corticosteroids (ICS) with or without long-acting bronchodilators are effective at reducing all-cause mortality in chronic obstructive pulmonary disease (COPD) patients, may be subject to immortal time bias.

This bias was assessed using a population-based cohort of 3,524 newly treated COPD patients from Saskatchewan, Canada, observed from 1990–1999. Regular users of bronchodilators or ICS were followed for 3 yrs, during which time 860 deaths occurred. Cox's proportional hazards model was used to compare the hierarchical intention-to-treat approach employed in the recent study, a technique subject to bias from two sources of immortal time, with the conventional intention-to-treat approach and the according-to-treatment approach.

The adjusted rate ratio of death using the hierarchical intention-to-treat approach was 0.66 (95% confidence interval (CI) 0.57–0.76) for ICS use relative to bronchodilator use, compared with 0.75 (95% CI 0.62–0.90) with the conventional intention-to-treat approach. Conversely, the rate ratio was 0.94 (95% CI 0.81–1.09) with the according-to-treatment approach, which accounts for both sources of immortal time.

In this study, regular inhaled corticosteroid use in chronic obstructive pulmonary disease was not found to reduce all-cause mortality. Suggestion of this benefit from a previous observational study is the result of bias from unaccounted immortal time in its cohort design and analysis.
Additive preventive effect of influenza and pneumococcal vaccines in elderly persons
Authors: Christenson B. , Hedlund J. , Lundbergh P. , Örtqvist Å.
Published: February 2004

In 1999, all individuals ≥65 yrs of age (n=258,754) in Stockholm County, Sweden, were offered influenza and pneumococcal vaccination in a prospective study on the effectiveness of these vaccines in reducing the need for hospital treatment and death due to influenza, pneumonia and invasive pneumococcal disease (IPD). Data on hospitalisation and mortality during 1 yr were obtained from the administrative database in Stockholm County Council.

Vaccination was performed in 124,702 (48%) subjects; 72,107 had both vaccines, 29,346 only had the influenza vaccine and 23,249 only had the pneumococcal vaccine. Compared with the unvaccinated cohort, a lower incidence of hospitalisation for all end-point diagnoses was seen in vaccinated persons.

An additive effectiveness of vaccination was seen when both vaccines were given, with a reduction of hospital admissions for influenza (37%), pneumonia (29%) and IPD (44%). In-hospital mortality for pneumonia was significantly lower in those who received both vaccines, than in unvaccinated persons.

To conclude, vaccination with influenza and pneumococcal vaccines together was effective in reducing the need for hospital admission for influenza and pneumonia. There was a strong indication that pneumococcal vaccination alone, was effective not only in the prevention of invasive pneumococcal disease, but also of pneumonia overall, although to a low degree.
No further increase in asthma, hay fever and atopic sensitisation in adolescents living in Switzerland
Authors: Braun-Fahrländer C. , Gassner M. , Grize L. , Takken-Sahli K. , Neu U. , Stricker T. , Varonier H.S. , Wüthrich B. , Sennhauser F.H. ,   the Swiss Study on Childhood Allergy and Respiratory symptoms with respect to Air Pollution (SCARPOL) team
Published: February 2004

Prevalence rates of childhood asthma and allergy have been on the increase for several decades. The present study investigated whether this trend continued during the 1990s in adolescents living in Switzerland.

Between 1992 and 2000, the change in prevalence of specific immunoglobulin E to aeroallergens, asthma symptoms and hay fever symptoms assessed by parents' and students' answers to the International Study of Asthma and Allergies in Childhood questions was investigated using three cross-sectional surveys. In total 1,324 (74.9%), 1,668 (80.6%) and 1,250 (73.9%) adolescents participated.

Prevalence rates of asthma and current asthmatic symptoms remained constant, irrespective of whether the assessment was based on parental questionnaires or the student's self-completed written or video questionnaires (students' report of current wheeze 8.8, 7.3, and 8.3%). Similarly, no further increase was observed for reported hay fever rates and allergic sensitisation rates (positive multiscreen allergy test, SX1-test: 34.6, 38.9, and 35.6%, respectively). Although time trends in the occurrence of a series of known risk factors were recorded, none of these factors had a significant impact on asthma and allergy prevalence over time.

No further increase in asthma and allergy rates occurred during the 1990s in adolescents living in Switzerland. However, to adequately assess the trend a longer period of observation is needed.
Comparison of single-breath and tidal breathing exhaled nitric oxide levels in infants
Authors: Franklin P.J. , Turner S.W. , Mutch R.C. , Stick S.M.
Published: February 2004

The aim of this study was to compare two different methods, tidal breathing (TB) and single-breath (SB), for measuring fractional exhaled nitric oxide (FENO) in infants.

FENOwas measured in 71 infants with either recurrent wheeze (n=32), recurrent cough (n=16) or no symptoms (healthy, n=23) using both methods. For TB measurements five breaths were collected into a gas sampling bag (off-line reservoir sampling). The SB method was modified from the raised volume rapid thoraco-abdominal technique. Agreement between the two methods was investigated and both methods were used to compare FENOin infants with and without symptoms.

Flow dependence of SB FENOwas demonstrated using two expiratory flows (11 and 40 mL·s−1). There was a moderate correlation (r=0.60) but poor agreement between levels using the TB and SB methods. A significant difference in FENObetween healthy children and children with wheeze was found using the SB but not the TB method.

Due to lower expiratory flow and reduced nasal nitric oxide contamination the single-breath technique may be more sensitive than the tidal breathing method for detecting differences in exhaled nitric oxide between infants with and without respiratory symptoms.
A short-term comparison of two methods of sputum expectoration in cystic fibrosis
Authors: Chatham K. , Ionescu A.A. , Nixon L.S. , Shale D.J.
Published: February 2004

The aim of this study was to determine whether repeated maximum inspiratory vital capacity manoeuvres against a fixed resistance increased effective short-term sputum clearance in adults with cystic fibrosis (CF).

Twenty adults with CF were randomised to receive, on alternate days, either standardised physiotherapy (SP) for 30 min, comprising postural drainage and the active cycle of breathing technique, or a series of resistive inspiratory manoeuvres (RIM) at 80% of their maximum sustained inspiratory pressure developed between residual volume and total lung capacity during the first 4 days of the treatment of an exacerbation of respiratory symptoms. Expectorated sputum was collected during and for 30 min after each treatment and weighed. Total protein, immunoreactive interleukin (IL)‐8 and human neutrophil elastase (HNE) concentrations, and the amount of each component expectorated, were determined.

Compared with SP, RIM increased sputum weight two-fold, independent of treatment order or day. The concentrations of protein, IL-8 and HNE in sputum were similar for both treatments, while the quantity expectorated was greater with RIM treatment.

In conclusion, short-term resistive inspiratory manoeuvres treatment was more effective at clearing sputum and inflammatory mediators than standardised physiotherapy.
Primary pulmonary hypertension in families with hereditary haemorrhagic telangiectasia
Authors: Abdalla S.A. , Gallione C.J. , Barst R.J. , Horn E.M. , Knowles J.A. , Marchuk D.A. , Letarte M. , Morse J.H.
Published: February 2004

Primary pulmonary hypertension (PPH) is a rare but severe and progressive disease characterised by obstructive lesions of small pulmonary arteries. Patients with PPH often have mutations in the bone morphogenetic protein receptor type II (BMPR2) gene, whereas some carry mutations in the activin receptor-like kinase 1 (ALK‐1) gene, generally associated with hereditary haemorrhagic telangiectasia (HHT) type 2, a vascular dysplasia affecting multiple organs. The aim of this study was to determine whether members of families with PPH and confirmed or probable HHT hadALK‐1mutations.

ALK‐1andBMPR2mutation analysis was performed on deoxyribonucleic acid from affected members of four families with PPH and confirmed or suspected HHT.

ALK‐1mutations were identified in all four families and three novel mutations found in exon 10, leading to truncated proteins. In the fourth family, a missense mutation, previously reported in four independent HHT families, was detected in exon 8. Analysis of theBMPR2gene revealed no exonic mutations in the probands with both PPH and HHT.

The present data bring to 10 the number of reported families with primary pulmonary hypertension and hereditary haemorrhagic telangiectasia type 2, representing 16% of the 61 families with known activin receptor-like kinase 1 mutations. Such mutations might predispose to primary pulmonary hypertension, and specialists should be aware of the potential link between these two disorders.
Response of pulmonary tuberculomas to anti-tuberculous treatment
Authors: Lee H.S. , Oh J.Y. , Lee J.H. , Yoo C.G. , Lee C‐T. , Kim Y.W. , Han S.K. , Shim Y‐S. , Yim J-J.
Published: February 2004

Pulmonary tuberculomas are well-circumscribed masses caused byMycobacterium tuberculosis. However, the response of tuberculomas to anti-tuberculous (TB) treatment has not been well defined as yet.

The response of pulmonary tuberculomas to anti‐TB treatment was retrospectively reviewed in 45 patients diagnosed between January 1997 and December 2001. The areas of pulmonary tuberculomas were estimated by calculating products of the longest and their perpendicular short diameters on chest radiographs. The response to anti‐TB treatment was categorised as “decreased” (>25% reduction in areaversusits initial area), “increased” (>25% increase) and “no change” (the remainder).

The mean of treatment duration was 11.5±3.6 months. Three months after treatment, 18 patients (40.0%) were categorised as decreased, 25 (55.6%) as no change and two (4.4%) as increased. Twelve months after treatment, out of 42 patients available for chest radiographs, 32 patients (76.2%) were categorised as decreased, nine (21.4%) as no change and one patient (2.4%) as increased. At the last follow-up (mean follow-up 27.0±10.2 months), 37 patients (82.2%) were categorised as decreased.

The majority of pulmonary tuberculomas were decreased by anti-tuberculosis treatment during and even after treatment, although a transient enlargement during the early period of treatment was observed infrequently.
Strategies to increase limited donor resources
Authors: de Perrot M. , Weder W. , Patterson G.A. , Keshavjee S.
Published: February 2004

A number of strategies have been advocated to increase the number of lung donors including: 1) improvement in donor resuscitation; 2) better methods of lung preservation; 3) extension of the lung donor selection criteria; 4) development of a living-related lung donor programme; and 5) utilisation of nonheart beating donors.

Other strategies such as the split-lung technique and techniques of lung reduction to accommodate large lungs into a small-size recipient have also been used successfully. In this article, each of these strategies have been reviewed and some recommendations are suggested based on the authors' own experience and that of the literature.
Effects of obesity upon genioglossus structure and function in obstructive sleep apnoea
Authors: Carrera M. , Barbé F. , Sauleda J. , Tomás M. , Gómez C. , Santos C. , Agustí A.G.N.
Published: February 2004

Obesity is a common feature of the obstructive sleep apnoea syndrome. It can influence the structure and function of skeletal muscles. However, its effects upon the upper airway muscles have not been explored directly.

This study assessed the structure and function of the genioglossus in patients with obstructive sleep apnoea syndrome and in healthy subjects (with and without obesity, defined by a body mass index >30 kg·m−2). Further, to investigate the effects of continuous positive airway pressure (CPAP) treatment, patients with obstructive sleep apnoea syndrome after at least 1 yr under CPAP were also studied.

The study found that obese and nonobese patients showed differentin vitrogeniglossus endurance properties. In obese patients, geniglossus endurance was indistinguishable from normal while, nonobese patients, at diagnosis, showed increased genioglossus fatigability; this was not observed in patients treated with CPAP. By contrast, patients with obstructive sleep apnoea syndrome showed at diagnosis a higher percentage of type II fibres than controls and patients under CPAP treatment independently of obesity. This difference is mainly due to a predominance of subtype IIb fibre. This difference was not observed in the group of patients treated with CPAP. Genioglossus twitch force was normal in all patients.

These results suggest that different pathogenic mechanisms may underlie the development of obstructive sleep apnoea syndrome in obese and nonobese patients. This observation may have potential clinical implications.
Geomorphological applications of cosmogenic isotope analysis
Authors: Cockburn Hermione A.P. , Summerfield Michael A.
Published: February 2004

Cosmogenic isotope analysis involves the measurement of cosmogenic nuclides that have accumulated in the upper few metres of the Earth’s surface as a result of interactions between cosmic rays and target elements. The concentrations of these cosmogenic nuclides can provide quantitative estimates of the timing and rate of geomorphic processes. In dating applications the concentration of cosmogenic nuclides is interpreted as reflecting the time elapsed since a surface exposure event. However, over most of the Earth’s surface for most of the time the landsurface experiences incremental denudation and in these circumstances cosmogenic nuclide concentrations are related to the rate of denudation. Applications of event dating using cosmogenic isotopes include constructional landforms such as volcanic and depositional features, fault displacement, meteorite impacts, rapid mass movement, bedrock surfaces rapidly eroded by fluvial or wave action or exposed by glacial retreat, and the burial of sediment or ice. Strategies for quantifying rates of incremental change include estimates of denudation rates from site-specific samples and from fluvial sediment samples reflecting catchment-wide rates, and measurements of cosmogenic nuclide concentrations in soils and regolith to quantify rates of rock weathering. The past decade has seen a rapid growth in applications of cosmogenic isotope analysis to a wide range of geomorphological problems, and the technique is now playing a major role in dating and quantifying rates of landscape change over timescales of several thousands to several millions of years.
Observation and simulation of dew in rural and urban environments
Authors: Richards K.
Published: February 2004

Dew has broad relevance to physical geography and many human activities. This paper reviews the observation and simulation of rural and urban dew, and the implications of dew as a climatic phenomenon. There is no universal protocol for measuring dew (i.e., condensation on cooled surfaces), its component fluxes (dewfall and distillation) or guttation, which is ‘dewdrops’ exuded from leaves. The many methods that exist to measure dew and surface moisture range from simple visual assessment, to electronic wetness sensors, lysimetry and remote sensing. Most studies of dew are rural; urban dew data are rare and studies seldom address dew in patchy landscapes, e.g., a forest clearing. Hardware dew models are rare. Numerous numerical models exist to simulate or forecast dew on rural crops but few address dew for surfaces other than leaves, e.g., a cocoa pod or road. There is a general consensus in the literature that dew is reduced or absent in cities because of the urban heat island effect and reduced vapour supply. However, little data exist to test this. Given the broad relevance of dew to many topics, future studies of dew in complex landscapes, including urban areas, would prove valuable.
Artificial drainage of peatlands: hydrological and hydrochemical process and wetland restoration
Authors: Holden J. , Chapman P. J. , Labadz J. C.
Published: February 2004

Peatlands have been subject to artificial drainage for centuries. This drainage has been in response to agricultural demand, forestry, horticultural and energy properties of peat and alleviation of flood risk. However, there are several environmental problems associated with drainage of peatlands. This paper describes the nature of these problems and examines the evidence for changes in hydrological and hydrochemical processes associated with these changes. Traditional black-box water balance approaches demonstrate little about wetland dynamics and therefore the science of catchment response to peat drainage is poorly understood. It is crucial that a more process-based approach be adopted within peatland ecosystems. The environmental problems associated with peat drainage have led, in part, to a recent reversal in attitudes to peatlands and we have seen a move towards wetland restoration. However, a detailed understanding of hydrological, hydrochemical and ecological process-inter-actions will be fundamental if we are to adequately restore degraded peatlands, preserve those that are still intact and understand the impacts of such management actions at the catchment scale.
Interactive effects of the ACE DD polymorphism with the NOS III homozygous G849T (Glu298→Asp) variant in determining endothelial function in coronary artery disease
Authors: Schmidt Michael A , Chakrabarti Anjan K , Kehrer Chris , Pfeninnger Dana , Brook Robert D , Kaciroti Niko , Duvernoy Claire , Killeen Anthony A , Rajagopalan Sanjay
Published: February 2004

The products of nitric oxide synthase (NOS) and angiotensin-converting enzyme (ACE) play a critical role in determining vessel wall structure and function. Polymorphisms in both genes have been independently demonstrated to influence propensity to cardiovascular events. The purpose of this study was to determine the influence of the homozygous G849T(Glu298 Asp) polymorphism in NOS III on peripheral conduit artery endothelial function and to elucidate the modifier role, if any, of a common ACE polymorphism.

Three hundred and ninety-seven consecutive subjects presenting to the cardiac catheterization laboratory of the University of Michigan over a period of 18 months were recruited. DNA was extracted and polymerase chain reaction (PCR) analysis for ACE and NOS polymorphisms performed. Patients with homozygosity for G849T at both loci (TT) who belong to DD and II ACE genotype (groups 1 and 2) and those who are negative for this polymorphism (GG) and belong to either DD or II genotype (groups 3 and 4) were identified. The four groups then underwent determination of conduit endothelial function. Heterozygosity of Glu298-Asp or the ID variant of the ACE were not studied.

Median FMD value in the TT-DD group was 0.20 (-3.17, 2.01) compared with 2.23% (-0.29, 4.17) in the GG-II group. Median values in the TT-II and the GG-DD groups were 3.04 (-1.16, 6.61) and 2.46% (-1.83, 6.52) respectively. These values were not statistically significant (p > 0.05 by one-way ANOVA). Median nitroglycerin-mediated dilation in the four groups did not differ between the four groups (p = NS by ANOVA). Atherosclerosis burdens as assessed by angiography were not different across the groups.

In conclusion, the homozygous NOS III variant (GG) status does not seem to interact additively with the ACE homozygous DD genotype in determining flow-mediated vasodilation in individuals with established atherosclerosis and pre-existent endothelial dysfunction.
Neovascularization in intimal hyperplasia is associated with vein graft failure after coronary artery bypass surgery
Authors: Baklanov Dmitri V , Peters Kevin G , Seidel Amy L , Taylor Doris A , Annex Brian H
Published: February 2004

Vein graft atherosclerosis is the major limitation of arterial bypass surgery. This study was carried out to determine if the number of microvessels per area of intimal hyperplasia correlated with vein graft disease. Vein grafts (n=24, graft age range 2-19 years) were taken from 22 patients undergoing redo-coronary artery bypass surgery. Mean age of the patients was 68 6 9 years; 92% were males. Samples were divided into three groups (n=8 per group): in group I segments were from grafts without angiographic or histologic disease, in groups II and III segments were from grafts with significant angiographic stenosis, without (group II) and with (group III) atheroma. Intimal hyperplasia was identified by Masson staining, morphometric analysis was performed with NIH image analysis software. Microvessels in the intimal hyper-plasia were identified using immunohistochemical techniques. significance was determined by single-factor ANOVA p, 0.05.

The mean area of intimal hyperplasia was similar in groups I and II at 1.06 6 0.25mm2 and 0.97 6 0.37mm2, respectively. The extent of intimal hyperplasia was significantly greater in group III, 1.70 6 0.62mm2 (p < 0.01). In group I, the microvessel count in the intimal hyperplasia was 5.62 6 3.89 vessels/mm2, while in group III it was 15.26 6 3.66/mm2 (p < 0.01 versus group I). Interestingly the number of microvessels per area of intimal hyperplasia in group II was similar to that in group III).

In this study, the extent of neovascularization in intimal hyperplasia correlated with stenoses in human vein grafts. Strategies designed to limit neovascularization in intimal hyperplasia may lead to novel therapies to prevent vein graft failure.
Oral L-arginine and vitamins E and C improve endothelial function in women with type 2 diabetes
Authors: Regensteiner Judith G , Popylisen Shawn , Bauer Timothy A , Lindenfeld JoAnn , Gill Edward , Smith Susan , Oliver-Pickett Cheryl K , Reusch Jane EB , Weil John V
Published: February 2004

Endothelial dilator function is impaired in people with type 2 diabetes mellitus (T2DM). Prior research indicates that this can be improved with intravenous administration of ascorbate or L-arginine, but whether these agents have this effect when administered by the clinically practical oral route is unknown. To investigate this question, 10 premenopausal women with T2DM and 10 healthy, premenopausal, non-diabetic women received, in random sequence, a 1-week administration of oral L-arginine (9 g daily) or vitamins E (1800 mg) and C (1000 mg) with an intervening 1-week washout period. Flow-mediated brachial artery dilation (FMD) was measured by ultrasonography and forearm blood flow was measured by plethysmography before and following blood pressure cuff-induced forearm ischemia before and after each week of treatment. At baseline, the women with T2DM had lesser FMD responses (0.028 ± 0.006 cm vs 0.056 ± 0.008 cm, p, 0.05). Post-ischemic forearm hyperemia was reduced at baseline in T2DM compared with controls (16.4 ± 1.8 vs 26.0 ± 1.4 ml 100 ml-1 min-1, p <0.05). Administration of L-arginine caused a 50 ± 12% increase in FMD in T2DM (p < 0.05) and raised post-ischemic forearm blood flow by 29 ± 8% (p < 0.05). No significant changes were seen in controls. Administration of vitamins E and C in women with T2DM produced an increase in the brachial artery diameter response of 79 ± 15% (p < 0.05), but did not significantly increase the hyperemic blood flow response (p = NS). No significant changes in the responses of controls from pre to post vitamin administration were observed. We concluded that administration of two types of oral agents improved measures of endothelial function in people with T2DM.
Plasma asymmetric dimethylarginine modifies the effect of pravastatin on myocardial blood flow in young adults
Authors: Janatuinen Tuula , Laakso Juha , Laaksonen Reijo , Vesalainen Risto , Nuutila Pirjo , Lehtimäki Terho , Raitakari Olli T , Knuuti Juhani
Published: February 2004

Elevated plasma levels of the endogenous nitric oxide synthase inhibitor asymmetric dimethylarginine (ADMA) are related to decreased myocardial vasodilatory capacity and increased risk of acute coronary events. As statin treatment is known to increase nitric oxide bioavailability and enhance myocardial function, we tested whether ADMA concentration modi-fies the effect of pravastatin on myocardial blood flow in young adults with mild hypercholesterolemia. Fifty-one men (35 ± 4 years) were randomly assigned to receive either pravastatin (40 mg/day) or placebo for 6 months. Myocardial blood flow was measured at rest and during adenosine-induced hyperemia using positron emission tomography and oxygen-15-labeled water at baseline and after treatment. Plasma ADMA levels were assessed with high performance liquid chromatography. Low baseline plasma ADMA concentration (< median) predicted a significant improvement of adenosine-induced blood flow after statin intervention (baseline to follow-up change +35%, p = 0.004), whereas high baseline ADMA (≥ median) was associated with no increase in adenosine-induced flow.
Deferoxamine-fibrin accelerates angiogenesis in a rabbit model of peripheral ischemia
Authors: Chekanov Valeri S , Zargarian Mehdi , Baibekov Iskander , Karakozov Paul , Tchekanov Guennady , Hare John , Nikolaychik Victor , Bajwa Tanvir , Akhtar Masood
Published: February 2004

The intramuscular (IM) injection of a modified fibrin meshwork plus deferoxamine was tested in a rabbit model of acute hind-limb ischemia. After excision of the left external iliac and femoral arteries, 12 rabbits at the Milwaukee Heart Institute were divided into two groups: control and fibrin meshwork plus deferoxamine (FDEF) IM. The rabbits underwent angiography before surgery, immediately after, and 1 month postoperatively. These data were compiled through counting by means of a grid overlay. Another 12 rabbits at the Vakhidov Center of Surgery, which did not undergo angiography, underwent lower limb-calf blood pressure (LCBP) measurements made immediately after surgery and at postoperative days 10, 20 and 30. Biopsies from thigh skeletal muscles of rabbits that had L-CBP measurements underwent alkaline phosphatase staining on day 30 to determine the percentage of biopsied area that was occupied by capillaries. The number of arteries and arterioles crossing 71 grid intersections immediately post-surgery decreased from 30.2 6 2.3 to 18.0 6 2.0 (p, 0.05). One month post-surgery this number increased to 29.2 6 2.4 in controls (p, 0.05 vs immediately post-surgery) and to 59.6 6 3.2 in the FDEF group (p, 0.001 vs immediately post-surgery). By day 30 the L-CBP ratio improved in the FDEF group (0.8 6 0.02) vs controls (0.3 6 0.04). By day 30 the capillary density increased from that of normal muscle tissue (198.6 6 12.9/mm2) to 292 612.4/mm2 in the FDEF group (p, 0.05), but decreased in the control group to 98.7 6 7.7/mm2. IM injection of FDEF considerably accelerated angiogenesis in severely ischemic hind-limb tissue in this model, making it a viable treatment method for clinical use in patients who have critical limb ischemia.
Iron and peripheral arterial disease: revisiting the iron hypothesis in a different light
Authors: Ramakrishna Gautam , Rooke Thom W , Cooper Leslie T
Published: February 2004

The relationship between iron status and atherosclerosis has long been a topic of debate in the literature. Despite more than 25 years of research, there is no consensus regarding a causal relationship. To date, the vast majority of studies have focused on iron burden with respect to a hypothesized role in the onset and progression of coronary artery disease. However, the effect of iron in the coronary arterial system may differ mechanistically and therefore clinically from its effect in the peripheral arterial system. This review will summarize the biochemical, pathologic, animal, and clinical research data with respect to iron and atherosclerosis. This background will be expanded upon to provide insights into ongoing studies and paths for future investigations into the role of iron and peripheral arterial disease.
Fibrinogen - marker or mediator of vascular disease?
Authors: Reinhart Walter H
Published: February 2004

Fibrinogen plays a key role in platelet aggregation, the final step of the coagulation cascade, i.e. the formation of fibrin, and it is a major determinant of plasma viscosity and erythrocyte aggregation. It is both constitutively expressed and inducible during an acute phase reaction. Increased plasma fibrinogen levels are associated with an increased risk of coronary heart disease and myocardial infarction. The question as to whether fibrinogen is only a marker of the inflammatory process involved in atherosclerosis or a mediator, i.e. a pathogenic factor, has not yet been answered. Human in vivo studies do not permit a conclusive answer to this question. If it is a pathogenic factor, fibrinogen lowering would be a therapeutic option. Selective fibrinogen-lowering agents do not exist however. All agents that lower fibrinogen also have other cardiovascular effects such as a decrease in cholesterol or inflammation. Newer information stems from molecular biology. Polymorphisms in the human fibrinogen gene with higher fibrinogen levels do not increase the risk for myocardial infarction. Fibrinogen knockout mice crossed with an atherosclerosis-susceptible strain (apoprotein E null mice) did not show a decreased extent of atherosclerosis despite the absence of fibrinogen, and a mouse strain over-expressing fibrinogen did not show an increased degree of atherosclerosis. Thus, fibrinogen seems to be a marker rather than a mediator of vascular disease, which would make selective fibrinogen lowering a useless preventive or therapeutic strategy.
Acquired arteriovenous malformation induced by pressure: a case report
Authors: Mekkes JR , Pasch MC , Meijs M , Smitt JH Sillevis
Published: February 2004

Arteriovenous malformations may be congenital or acquired. In the latter case, usually a traumatic injury to the arteries precedes the arteriovenous anastomoses. Two elderly patients presented with large, purple-colored verrucous tumors on the buttocks. Both patients were obese and immobile, and reported repeated bleeding from the lesions after minor trauma. The tumors were soft and could be emptied by applying pressure. Doppler examination revealed arterial pulsations over the lesions. Both cases were diagnosed as pressure-induced arteriovenous malformations. The lesions are assumed to have been caused by tissue damage in the deep subcutis induced by decubitus.
Synthesis, Electronic Properties, and Applications of Indium Oxide Nanowires
Authors: LI C , ZHANG D , HAN S , LIU X , TANG T , LEI B , LIU Z , ZHOU C
Published: February 2004

Abstract: Single‐crystalline indium oxide nanowires were synthesized using a laser ablation method and characterized using various techniques. Precise control over the nanowire diameter down to 10 nm was achieved by using monodisperse gold clusters as the catalytic nanoparticles. In addition, field effect transistors with on/off ratios as high as 104 were fabricated based on these nanowires. Detailed electronic measurements confirmed that our nanowires were n‐type semiconductors with thermal emission as the dominating transport mechanism, as revealed by temperature‐dependent measurements. Furthermore, we studied the chemical sensing properties of our In2O3 nanowire transistors at room temperature. Upon exposure to a small amount of NO2 or NH3, the nanowire transistors showed a decrease in conductance of up to five or six orders of magnitude, in addition to substantial shifts in the threshold gate voltage. Our devices exhibit significantly improved chemical sensing performance compared to existing solid‐state sensors in many aspects, such as the sensitivity, the selectivity, the response time and the lowest detectable concentrations. We have also demonstrated the use of UV light as a “gas cleanser” for In2O3 nanowire chemical sensors, leading to a recovery time as short as 80 seconds.
Molecular Electronics on Silicon: An Ultrahigh Vacuum Scanning Tunneling Microscopy Study
Authors: GUISINGER NATHAN P. , BASU RAJIV , BALUCH ANDREW S. , HERSAM MARK C.
Published: February 2004

Abstract: An ultrahigh vacuum scanning tunneling microscope (STM) was employed as a tool to characterize two distinct molecular electronic strategies on the Si(100) surface. Initially, the self‐directed growth of one‐dimensional styrene molecular chains on hydrogen‐passivated Si(100) was investigated. High‐resolution empty states imaging of these styrene nanostructures confirms alignment of phenyl groups along the chain. However, attempts at STM charge transport measurements were limited by tip induced desorption of styrene molecules. Consequently, an alternative oxygen radical chemistry was also investigated. In particular, the chemical adsorption of 2,2,6,6‐tetramethyl‐1‐piperidinyloxy (TEMPO) onto clean Si(100) leads to the formation of an exceptionally stable silicon‐oxygen bond that can withstand high bias charge transport measurements up to ± 5 volts. Direct charge transport measurements through individual TEMPO molecules on degenerately n‐type doped Si(100) reveal room temperature negative differential resistance behavior for negative sample biases exceeding ‐ 3 volts.
An Overview of the First Half‐Century of Molecular Electronics
Authors: HUSH NOEL S.
Published: February 2004

Abstract: The seminal ideas from which molecular electronics has developed were the theories of molecular conduction advanced in the late 1940s by Robert S. Mulliken and Albert Szent‐Gyorgi. These were, respectively, the concept of donor‐acceptor charge transfer complexes and the possibility that proteins might in fact not be insulators The next two decades saw a burgeoning of experimental and theoretical work on electron transfer systems, together with a lone effort by D.D. Eley on conduction in proteins. The call by Feynman in his famous 1959 lecture There's Plenty of Room at the Bottom for chemists, engineers and physicists to combine to build up structures from the molecular level was influential in turning attention to the possibility of engineering single molecules to function as elements in information‐processing systems. This was made tangible by the proposal of Aviram and Ratner in 1974 to use a Mulliken‐like electron donor‐acceptor molecule as a molecular diode, generalizing molecular conduction into molecular electronics. In the early 1970s the remarkably visionary work of Forrest L. Carter of the U.S. Naval Research Laboratories began to appear: designs for molecular wires, switches, complex molecular logic elements, and a host of related ideas were advanced. Shortly after that, conferences on molecular electronics began to be held, and the interdisciplinary programs that Feynman envisaged. There was a surge in both experimental and theoretical work in molecular electronics, and the establishment of many research centres. The past five years or so have seen extraordinarily rapid progress in fabrication and theoretical understanding. The history of how separate lines of research emanating from fundamental insights of about 50 years ago have coalesced into a thriving international research program in what might be called the ultimate nanotechnology is the subject of this review; it concentrates on the lesser‐appreciated early developments in the field.
Understanding Charge Transport in Molecular Electronics
Authors: KUSHMERICK J J. , POLLACK S K. , YANG J C. , NACIRI J , HOLT D B. , RATNER M A. , SHASHIDHAR R
Published: February 2004

Abstract: For molecular electronics to become a viable technology the factors that control charge transport across a metal‐molecule‐metal junction need to be elucidated. We use an experimentally simple crossed‐wire tunnel junction to interrogate how factors such as metal‐molecule coupling, molecular structure, and the choice of metal electrode influence the current‐voltage characteristics of a molecular junction.