bluuebunny/crossref_metadata_2025 huggingface dataset:
Prostaglandins mediate bradykinin-induced reduction of exhaled nitric oxide in asthma
Authors: Kharitonov SA , Sapienza MM , Chung KF , Barnes PJ
Published: July 2002

Bradykinin (BK) is a mediator of inflammation in asthma with potent bronchoconstrictor actions. Endogenous release of nitric oxide may inhibit BK-induced bronchoconstriction. This study investigated whether bradykinin inhalation could modulate exhaled NO levels in normal and asthmatic subjects, and whether the bradykinin-induced effects were mediated through the production of cyclo-oxygenase products in patients with asthma, by studying the effect of the cyclo-oxygenase inhibitor, L-acetylsalicylic acid (L-ASA). Exhaled NO concentration and forced expiratory volume in one second (FEV1) were measured by chemiluminescence following inhalation of increasing concentrations of BK. In asthmatics (n=11), BK induced a dose-dependent decrease in exhaled NO concentration from 21.3+/-1.6 to 6.+/-0.5 parts per billion (ppb) (p<0.01) at the highest concentration, associated with a significant fall in FEV1. In normal subjects (n=10), the exhaled NO concentration fell from 7.2+/-0.13 to 4.3+/-0.51 ppb (p<0.001) 15 min, after a single inhalation of BK, but without a significant change in FEV1. In asthmatic subjects, pretreatment with inhaled L-ASA (90 x mg x mL(-1), 4 mL) did not alter exhaled NO levels, but prevented a BK-induced fall in exhaled NO concentration, as indicated by a significant increase in exhaled NO levels at the provocative concentration of BK causing a 20% fall in FEV1, (5.7 +/- 0.94 ppb after placebo and 12.0 +/- 1.8 ppb after L-ASA; p<0.05). L-ASA significantly reduced bronchial responsiveness to BK 3.9-fold (p<0.01). Inhaled bradykinin induced bronchoconstriction and a reduction in exhaled nitric oxide levels in asthmatic subjects, an effect that is partly mediated by cyclo-oxygenase products.
Persistent high BAL fluid granulocyte activation marker levels as early indicators of bronchiolitis obliterans after lung transplant
Authors: Riise GC , Andersson BA , Kjellstrom C , Martensson G , Nilsson FN , Ryd W , Schersten H
Published: July 2002

The major cause of mortality in the long-term in lung transplant recipients is chronic rejection. This is a fibroproliferative process in the small airways leading to obliterative bronchiolitis and progressive loss of lung function, both constituting the clinical entity bronchiolitis obliterans syndrome (BOS). Granulocyte activation has been implicated as one factor behind BOS. Granulocyte markers in bronchoalveolar lavage (BAL) fluid were prospectively and longitudinally studied in order to identify possible association with BOS. BAL fluid from 266 bronchoscopy procedures performed in twelve single lung, eight bilateral lung and five heart/lung transplant recipients were analysed. The majority (19 of 25) were studied for a period of 2 yrs after surgery. Myeloperoxidase (MPO), eosinophil cationic protein (ECP) and interleukin-8 (IL-8) levels were used as indirect markers of activation and attraction of granulocytes. Five patients developed BOS. Ninety-eight episodes of acute rejection, nine of bacterial infection, 19 of cytomegalovirus pneumonitis, nine of Pneumocystis carinii infection, two of aspergillus infection and two of respiratory syncytial virus infection were diagnosed. BOS patients had significantly higher mean levels of MPO, ECP and IL-8 compared to patients without BOS, irrespective of acute rejection status. Over time, the five patients with BOS had significantly elevated BAL fluid levels of MPO and ECP as well as neutrophil percentages, and in four patients this increase preceded the clinical diagnosis of BOS by several months. Elevated bronchoalveolar lavage fluid neutrophil percentage as well as levels of the granulocyte activation markers myeloperoxidase and eosinophil cationic protein appear to be early signs of development of BOS in lung transplant recipients.
Lung function and short-term outcome in young asthmatic children
Authors: Klug B , Bisgaard H
Published: July 2002

The aims of this study were to investigate lung function in 2-5-yr-old stable asthmatic children consecutively referred from general practitioners and to analyse the outcome on the basis of their requirement for antiasthmatic treatment and symptoms after 1.6-4.5 yrs. Lung function was measured in 110 children with a mean+/-SD age of 3.8+/-1.0 yrs using the interruptor technique (resistance assessed using the interruptor technique (Rint)), whole body plethysmography (specific airway resistance (sRaw) and respiratory resistance (Rrs,5)and reactance at 5 Hz (Xrs,5) using the impulse oscillation technique. Rint, sRaw, Xrs,5 and Rrs,5 were suggestive of impaired lung function in 44%, 14%, 11% and 7.5% of the children, respectively, with a predominance of children aged 2-3 yrs. Sixty-five per cent were treated with inhaled steroids, and 35% were treated only with beta2-agonists as needed; lung function was not significantly different between these two groups. Outcome after 2.9+/-0.7 yrs was not significantly different between children with Rint measurements above and those children with Rint measurements within the reference range at enrolment. Of these children, 58 and 59% were currently on antiasthmatic treatment, and 40% and 49% had current symptoms, respectively. Impairment of lung function may be a common finding in stable young asthmatic children, but apparently this is not a risk factor for persistence of asthmatic symptoms.
Alveolar macrophage immaturity in infants and young children
Authors: Grigg J , Riedler J , Robertson CF , Boyle W , Uren S
Published: July 2002

Very little is known about alveolar macrophage (AM) immunological function in early childhood. Using nonbronchoscopic bronchoalveolar lavage (BAL), this study sought to compare the proportion, number, and function of AM between very young and older children. BAL fluid (BALF) leukocyte parameters were determined in 63 children, and data divided into 3 age groups: group 1 (<2 yrs), group 2 (> or =2-< or =5 yrs) and group 3 (> or =6-< or =17 years). In a further subgroup of children, AM function and immune receptor expression were assessed, and data categorized into two age groups: <2 yrs and > or =2 yrs of age. Compared to groups 2 and 3, the AM percentage in the BAL in group 1 was significantly increased (median: 98% versus 92% and 91%), as was the albumin-adjusted AM concentration. AM from children <2 yrs expressed less human leukocyte antigen (HLA)-DR (versus > or =2 yrs of age), were less effective in reducing nitro blue tetrazolium, and released less interleukin (IL)-1 and tumour necrosis factor on lipopolysaccharide stimulation. There was no difference in release of IL-6, expression of intercellular adhesion molecule-1 (CD54), and AM stimulation of allogeneic T-cells, between children <2 yrs and > or =2 yrs of age. It was concluded that the capacity of alveolar macrophage to stimulate T-cells is not enhanced in early childhood, and that immaturity of alveolar macrophage function may contribute to an increased susceptibility to respiratory infections in this age group.
Some thoughts on the advanced control of electric power plants
Authors: Rees N. W. , Lu C. X.
Published: July 2002

Over the last decade, there has been considerable change in the electric power generation industry. Larger, faster plants have been constructed and old plants have been forced to operate in a much more dynamic environment, thanks to strong competition and market forces. Massive changes have also occurred in information technology, designed to improve power plant performance, by including large amounts of computing and digital circuits, together with very advanced man-machine interface tools, allowing efficient information retrieval and display at reasonable cost. By contrast, the control systems implemented in the distributed control computer systems remain largely conventional control, a mix of various types of PID control and feedforward, which is not at all what is thought of as advanced control. This paper looks at this issue, and describes some of the advanced controllers that might be very effective in the industry, including many that are being offered to the industry by the control vendor companies. The paper then tries to give reasons why these systems have not been taken up in any significant way, and by using examples from our own experience, attempts to suggest how the situation might be improved.
Phosphorylcholine coating offers natural platelet preservation during cardiopulmonary bypass
Authors: De Somer F , Van Belleghem Y , Caes F , François K , Arnout J , Bossuyt X , Taeymans Y , Van Nooten G
Published: July 2002

Return of blood activated by tissue factor is the main culprit for triggering the coagulation cascade. When this activated blood is diverted from the cardiopulmonary bypass (CPB) circuit, it becomes possible to evaluate the effect of surface treatment on platelet and complement activation. Twenty adult patients undergoing elective coronary artery bypass grafting (CABG) were randomly assigned either to a control group ( n= 10) or to a group in which the CPB circuit was completely coated with phosphorylcholine ( n= 10). Plasma concentrations of platelet factor 4 (PF4), β-thromboglobulin (βTG), C3, C3d, C4, TCC, thrombin generation, haptoglobin and free haemoglobin, as well as blood loss, were measured. No significant differences between the two groups were found for haemolysis and thrombin generation. The mean total release of PF4 and βTG during CPB was 9338± 17303 IU/ml/CPB and 3790± 4104 IU/ml/CPB in the coated group versus 22192± 13931 IU/ml/CPB ( p= 0.011) and 8040± 3986 IU/ml/CPB ( p= 0.005) in the control group. Blood loss was 30% less in the coated group compared to the control group. Phosphorylcholine coating appears to have a favourable effect on blood platelets, which is most obvious after studying the changes during CPB. Clinically, this effect resulted in a 30% reduction in blood loss.
Coronary sinus rupture with retrograde cardioplegia
Authors: Kurusz Mark , Girouard Mark K , Brown Paul S
Published: July 2002

Coronary sinus (CS) rupture occurring during retrograde cardioplegia (RCP) is a rare complication. Patients with left ventricular hypertrophy are at higher risk for injury to the CS. The patient was a 66-year-old female with hypertension, ischemic cardiomyopathy and dysrhythmias, who had evidence of an anterior wall myocardial infarction, congestive heart failure and angina. During coronary artery bypass surgery, antegrade cardioplegia was initially administered, but aortic insufficiency prevented adequate myocardial cooling. RCP was then administered and the heart cooled appropriately. After approximately 300 ml of blood cardioplegic solution had been given, the CS pressure suddenly dropped from 30 mmHg to zero. RCP administration was stopped, and the surgeon palpated a hematoma over the area of the CS, which later ruptured upon rotation of the heart. A primary repair could not be performed, so a pericardial patch was placed over the area of disruption, which appeared to provide adequate hemostasis. The patient was weaned from cardiopulmonary bypass (CPB), but began to bleed freely from the CS distal to the pericardial patch. The patient was placed back on CPB to allow further repair of the CS, but the tissues were thin and friable and the ventricle disassociated from the ventricular septum. The situation was deemed not salvageable and further attempts at repair were stopped. The perfusionist should monitor infusion pressures and the CS waveform during RCP delivery. Changes in the waveform may indicate cannula malposition, loss of balloon seal, or, more rarely, CS rupture; such changes should prompt immediate cessation of RCP delivery.
Different patterns of heparin resistance: therapeutic implications
Authors: Ranucci Marco , Isgrò Giuseppe , Cazzaniga Anna , Ditta Antonio , Boncilli Alessandra , Cotza Mauro , Carboni Giovanni , Brozzi Simonetta
Published: July 2002

Heparin resistance (HR) during cardiac operations is a common feature. Its aetiology often recognizes a decrease in circulating antithrombin III (AT III) due to a preoperative heparin treatment. Nevertheless, some papers highlighted the existence of HR in patients with normal values of AT III. This paper was designed in order to identify this subgroup of AT III-independent heparin-resistant patients. Five hundred consecutive patients scheduled for coronary revascularization with cardiopulmonary bypass were enrolled in this prospective trial. HR was identified in 104 (20.8%) patients. Thirty-six of them (7.2% of the total population) had a preoperative AT III activity ≥100%, and were defined as AT III-independent heparin-resistant patients. This subgroup significantly differs from the AT III-dependent heparin-resistant group being affected by a less severe degree of HR and including less patients pretreated with heparin. Unlike the other heparin-resistant patients, these subjects do not respond to AT III supplementation aimed at reaching supranormal AT III activity values.
Repair of hypoplastic left heart syndrome of a 4.25-kg Jehovah’s witness
Authors: Forest Richard J , Groom Robert C , Quinn Reed , Donnelly Jon , Clark Cantwell
Published: July 2002

The care of patients who refuse homologous transfusions has challenged cardiac surgery teams to refine blood conservation techniques and question standard trans-fusion practices. We cared for a newborn child with hypoplastic left heart syndrome (HLHS) whose parents refused to give consent to care for the child that involved the transfusion of homologous blood. A Norwood Stage I procedure was planned with the understanding that transfusions would be avoided, if possible. A court order was obtained that specified the conditions under which the attending physicians would transfuse the newborn. The birth weight of the patient was 4.25 kg. A low prime cardiopulmonary bypass (CPB) circuit and aggressive blood conservation techniques that included modified ultrafiltration (MUF) allowed the completion of the repair and CPB portion of the operation without the use of blood. The lowest hematocrit during CPB was 20%. After an unsuccessful attempt to separate from CPB, blood was transfused. Recovery was consistent for HLHS patients following Norwood Stage I. However, at 1 month postoperatively, the patient did require a shunt reduction for pulmonary overcirculation. Norwood Stage II repair was completed at age 4 months without donor blood. The key to a successful outcome is a well-thoughtout plan by the surgeon, anesthesiologist and perfusionist. This plan should include careful monitoring of the patient’s oxygenation and cardiovascular status.
Assessment of activities of daily living with an ambulatory monitoring system: a comparative study in patients with chronic low back pain and nonsymptomatic controls
Authors: Spenkelink C D , Hutten M MR , Hermens H J , Greitemann B OL
Published: July 2002

Objective: The aim of this study was twofold: (1) to investigate whether differences in activities of daily living exist between patients with chronic low back pain (CLBP) and nonsymptomatic controls; (2) to investigate the day-today variability in daily activities.

Design: Physical activities were measured over a 24-hour period with an ambulant monitoring system.

Setting: Measurements were carried out in the subject's own environment.

Subjects: Forty-seven CLBP patients and 10 nonsymptomatic controls participated in this study.

Results: On group level, CLBP patients show a lower activity pattern compared with controls, especially during the evening. This is re‘ected in a lower walking step frequency during the day and evening, more lying time during the day and a lower physical activity level, less standing time and more lying time during the evening. The day-to-day variability in activity pattern is high and similar for both the patient and control group.

Conclusion: The lower activity level especially found during the evening might indicate that patients need all their capacity to perform the tasks imposed during the day and as a consequence have less capacity left for their leisure time, in general the evening. This suggests the existence of an imbalance between the patient's physical capacity and the imposed environmental load. The large but similar day-to-day variability in activity pattern, which does not support the clinical findings of ‘bad days’ in CLBP patients, suggests the need for repeated measures.
Speech and language therapy for dysarthria due to nonprogressive brain damage: a systematic Cochrane review
Authors: Sellars Cameron , Hughes Thomas , Langhorne Peter
Published: July 2002

Background: Dysarthria is a common sequel of nonprogressive brain damage (typically stroke and traumatic brain damage). Impairment-based therapy and a wide variety of compensatory management strategies are undertaken by speech and language therapists with this patient population.

Objective: To determine the efficacy of speech and language therapy interventions for adults with dysarthria following nonprogressive brain damage.

Design: Systematic review.

Search strategy: This review has drawn on the search strategies developed for the following Cochrane Groups as a whole: Stroke, Injuries, and Infectious Diseases. Relevant trials were identified in the Specialised Registers of Controlled Trials. We also searched the trials register of the Cochrane Rehabilitation and Related Therapies Field. The Cochrane Controlled Trials Register, MEDLINE, EMBASE, CINAHL, PsycLIT, and Linguistics and Language Behavior Abstracts were electronically searched. Hand-searching of the International Journal of Language and Communication Disorders and of reference lists from relevant articles and conference proceedings was also undertaken. Colleagues were approached to identify other possible published and unpublished studies.

Selection criteria: Unconfounded randomized controlled trials.

Data collection and analysis: One reviewer assessed trial quality. Two co-reviewers were available to examine any potential trials for possible inclusion in the review.

Main results: No trials of the required standard were identified.

Reviewers' conclusions: There is no evidence of the quality required by this review to support or refute the effectiveness of speech and language therapy interventions for dysarthria following nonprogressive brain damage. There is an urgent need for good quality research in this area.
Systematic reviews in rehabilitation for stroke: issues and approaches to addressing them
Authors: Greener J , Langhorne P
Published: July 2002

Objectives: To describe the problems encountered when undertaking systematic reviews of rehabilitation and to give advice to reviewers about ways of addressing these issues.

Background: Evidence-based practice has become established as a way of linking clinical practice with research evidence. The most robust evidence is usually considered to be that from randomized controlled trials, and from systematic reviews of these trials. However, most reviews have focused on drug and surgical interventions, and few reviews have been produced in the field of rehabilitation. This may be due to the unique difficulties that are posed by reviews in this area.

Experience of systematic reviews in aphasia: We describe the challenges that occurred when carrying out systematic reviews of speech and language therapy for aphasia following stroke, and of ways to deliver rehabilitation services to people who have suffered a stroke. Issues arose at all stages of the reviews and included: using expertise; planning the review; defining the health care problem, patients, outcomes and interventions of interest; searching for, interpreting and synthesizing the results of the studies identified; and deriving implications from the review. Suggestions made to address these challenges include: developing a suitable team of reviewers; using inclusive and broad criteria for inclusion of trials to a review; developing appropriate search strategies; and using caution in arriving at conclusions. It is important to be explicit about decisions made during the review process concerning how to handle the challenges. Practical advice about carrying out reviews in the field of stroke rehabilitation is likely to be helpful to reviewers of other rehabilitative interventions. There are likely to be relatively few studies available for such reviews, and limitations in drawing specific practical conclusions. Such undertakings are, however, useful in setting the agenda for further research.
Cognitive assessment and neurological rehabilitation
Authors: Wade Derick T
Published: July 2002

Two recent studies evaluating cognitive assessment in patients with multiple sclerosis and stroke found no benefit from providing information derived from a full cognitive assessment, and one study also failed to find any benefit following specific ‘cognitive treatments’. These studies might suggest that rehabilitation teams do not need clinical psychologists. However it is already known that isolated assessment does not affect outcome, and the nature and context of the assessments and interventions in these studies simply reinforces this. Thus, given the frequency of cognitive de.cits in these patients and given the strong evidence in favour of multi disciplinary teamwork in rehabilitation, these studies could be used as strong evidence that clinical psychologists should be integral members of all neurological rehabilitation teams.
Managing depression in brain injury rehabilitation: the use of an integrated care pathway and preliminary report of response to sertraline
Authors: Turner-Stokes Lynne , Hassan Nibras , Pierce Katherine , Clegg Frances
Published: July 2002

Aims: To use data generated from an integrated care pathway (ICP) to describe the characteristics of patients presenting with depression in a brain injury rehabilitation programme and to assess their response to treatment with sertraline.

Setting: A regional rehabilitation unit providing inpatient rehabilitation for young patients (16–65) with severe complex disabilities.

Design: Prospective cohort study of 82 patients admitted to the unit during the 15-month period between between 1 September 1999 and 1 December 2000. Response to sertraline was assessed in an open-label, before-andafter study design

Methods and design: All admissions were screened and included in the ICP if there was clinical suspicion of depression, past or present. Anti-depressant medication was prescribed, where appropriate, according to the ICP protocol. Depression was diagnosed on clinical grounds against DSM-IV criteria, and measured where feasible using the Beck Depression Inventory (BDI-II) administered by interview, pretreatment and at 6–8 weeks.

Results: Of 82 admissions 41 (50%) were managed using the ICP and 27 (64%) were either started on or changed to sertraline – 21 for depression ± lability and six for emotional lability only. All of the depressed patients improved clinically at some level and no signi”cant side-effects were observed. The BDI-II was assessable in 17/21 who showed a mean improvement of 14.5 ± 9.7 (con”dence interval (CI) 9.3–19.7, p < 0.001). Eleven patients (52%) had previously failed to respond with a different selective serotonin re-uptake inhibitor (SSRI) agent but still made a signi”cant response when changed to sertraline with a mean reduction in BDI-II of 16.3 ± 10.9 (CI 8.4–24.11, p < 0.001).

Conclusions: The ICP was practical to use and provided systematic data on assessment of depression and response to treatment in ‘real-life’ clinical practice in a brain injury rehabilitation setting. Sertraline appears to be useful and well-tolerated in this context. A full placebo-controlled study is now required.
Which cancer patients are referred to Hospital at Home for palliative care?
Authors: Grande G E , McKerral A , Todd C J
Published: July 2002

Previous research has shown that palliative home care use is influenced by variables such as age, socioeconomic status, presence of an informal carer, diagnosis, and care dependency. However, there is little information on its association with other health service use. This study compared 121 cancer patients referred to Hospital at Home (HAH) for palliative care with a sample of 206 cancer patients not referred who died within the same period. Electronic record linkage of NHS databases enabled investigation of patients' total input of care in their last year of life. Univariate analysis showed that patients referred to HAH were younger, lived in less deprived areas, were less likely to have been diagnosed within a month of death and to have causes other than cancer recorded on their death certificate. They were furthermore more likely to have had specialist oncology input, Macmillan nursing, Marie Curie nursing, acute hospital care, and district nursing before their last month of life. When care was received, patients referred to HAH received more hours of district nursing care. However, patients not referred to HAH began their acute hospital and district nursing input earlier (further from death) than those referred. Multivariate logistic regression analysis showed HAH referral to be negatively associated with breast and genitourinary cancers and number of noncancer causes recorded on the death certificate. Referral was significantly positively associated with specialist oncology input, Marie Curie nursing, and a late start (close to death) of acute hospital and district nursing care. It is hypothesised that referral to palliative home care is more likely among patients who have had prior contact with cancer services or are most clearly identified as cancer patients, and whose illness progression is manifested by a relatively short but intensive period of care prior to death.
Commercial cultures: Transcending the cultural and the economic
Authors: Jackson Peter
Published: July 2002

In recent years there have been repeated calls for a convergence between ‘the cultural’ and ‘the economic’. This paper provides a specific take on these issues through an exploration of the contested geographies of contemporary commercial culture. Traditionally, ‘culture’ has been associated with meaning and creativity, with works of the imagination and aesthetic practices that are far removed from the pursuit of economic profit. By contrast, ‘commerce’ has conventionally been regarded with disdain by critically minded social scientists, signalling a vulgar and materialistic world, devoid of morality, where human agency is subordinated to the logic of capital. This paper aims to challenge such dualistic thinking by exploring the commodification of cultural difference and by demonstrating that the rational calculus of the market is inescapably embedded in a range of cultural practices. The argument moves from an analysis of linear commodity chains to an exploration of more complex circuits and networks, illustrated with examples from contemporary commodity culture, looking specifically at the food and fashion sectors. Rather than demonstrating complexity for its own sake, the objective is to identify new forms of understanding and new possibilities for intervention in what can sometimes seem like an all-encompassing ‘consumer culture’ where every act of resistance is immediately recuperated in successive rounds of commodification.
Conceptualizing agriculture: a critique of post-productivism as the new orthodoxy
Authors: Evans Nick , Morris Carol , Winter Michael
Published: July 2002

It has become fashionable to conceptualize recent shifts in agrarian priorities as a ‘postproductivist’ transition from a previously ‘productivist’ agriculture. This notion became more popular throughout the 1990s as a way to capture in one convenient package the complex changes experienced by both the agricultural sector specifically and within rural areas more generally. However, the widespread and uncritical use of such an all-encompassing term is rather surprising given debates elsewhere in human geography on the rejection of dualistic thinking. Yet, in agricultural and rural studies, the active creation and reinforcement of a productivist/post-productivist dualism has emerged as a means of explaining the uneven development of rural areas. This paper develops a critique of post-productivism to demonstrate its invalidity, presenting empirical evidence to refute five supposed characteristics relating to quality food, pluriactivity, sustainability, production dispersion and regulation. It is argued that future progress in agricultural research will only be made if post-productivism is abandoned. Effort should be refocused upon understanding deeper processes underpinning agricultural change using existing theoretical perspectives developed in human geography but which lack application in the agricultural context. Ecological modernization is provided as a brief exemplar of how such progress may be achieved.
‘Nice maps, shame about the theory’? Thinking geographically about the economic
Authors: Lee Roger
Published: July 2002

What can geography tell us about the economy other than drawing maps of it? The spatiality of economic activity points towards the practical and performative complexity of the economic as well as to the complexity of geography in its embedding of the economic. While the synthetic nature of geography – its raison d'être is the relationships between, rather than the separation of, processes and things – disrupts economy in profound ways, its treatment by nonpractitioners is weak and over-narrowly interpreted. At the same time, a tendency for geographers to sidestep certain economic imperatives undermines more culturally and socially inflected interpretations of economy. What is at issue here, however, is not simply an attempt to reconcile two disciplines or to reclaim either one of them but a need to embed the one relationally in the other in mutually formative ways. This involves a transcendence of disciplinary perspectives by stressing the complex practices of social reproduction operating at all scales from the ultralocal to the hyperglobal. It is this stress on practice and instance, rather than a determinative claim for place or space, that makes geography matter in the construction of understandings of the economy.
Vegetation growth in rivers: influences upon sediment and nutrient dynamics
Authors: Clarke Stewart J.
Published: July 2002

Hydrological and geomorphological research in river environments has largely ignored the influence of instream vegetation growth; focusing rather on the role of riparian vegetation as a control on bank stability or as a potential buffer for dissolved and particulate material entering the channel from the hillslope. However, in many lowland streams instream vegetation may be abundant and reach high levels of biomass during the growing season. These instream plants (macrophytes) have a significant effect on flow, sediment and nutrient dynamics. Plant growth may cause increased frictional resistance to flow and through flow diversion may have a short-to medium-term influence on instream channel geomorphology. Additionally, this effect of plants upon flow velocities within the channel has an impact on sedimentation patterns. Rooted plants also function as a link between bed sediments and the water column, thus plants have a key role in the cycling of nutrients between these two components of the fluvial system. This, combined with the uptake and temporary storage of nutrients by the plants and the retention of fine sediments within dense plant stands, has the result that plants within rivers are an integral component of nutrient dynamics. A review of research on the role of macrophytes in fluvial system nutrient dynamics is presented and identifies the need for an increased understanding and recognition of the role of plants in the functioning of fluvial systems as a whole.
Effects of butylparaben on the male reproductive system in rats
Authors: Oishi Shinshi
Published: July 2002

Parabens are a group of compounds widely used as preservatives in foodstuffs, cosmetics, toiletries and pharmaceuticals. These compounds are known to exert a weak estrogenic activity, with butylparaben showing the most potent activity among methyl-, ethyl- and propyl esters in in vitro recombinant yeast assay and in in vivo uterotrophic assay. To account for potential reproductive effects in male animals, butylparaben was administered to 3-week- old Wistar rats divided in groups of eight subjects, at doses of 0.00%, 0.01%, 0.10% and 1.00% with the animal’s diet. After 8 weeks, the rats were killed by decapitation and the weights of the testes, epididymides, prostates, seminal vesicles and preputial glands were recorded. The absolute and relative weights of epididymides were decreased in a dose-dependent manner and the decrease was statistically significant at 0.10% and above. The cauda epididymal sperm reserve of all treated groups was significantly decreased. The sperm count of the group receiving the highest dose was 58.2% of control values. The daily sperm production (DSP) in the testis was also significantly lower in all treated groups when compared to controls. Serum testosterone concentration was lowered dose-dependently and was significant at 0.1% or more. The daily intake of butylparaben that caused these disruptions is similar to the lower level of acceptable daily intake (ADI) for parabens in the European Community (EC) and in Japan. The results of the present experiments show for the first time that exposure of a postweaning mammal to butylparaben had an adverse effect on the secretion of testosterone and in the functions of the male reproductive system.
Marine radiocarbon reservoir corrections for the midto late Holocene in the eastern subpolar North Atlantic
Authors: Reimer P. J. , McCormac F. G. , Moore J. , McCormick F. , Murray E. V.
Published: July 2002

The time dependency of the regional difference ΔR in the marine radiocarbon reservoir correction is an important issue for the calibration of marine radiocarbon ages and also provides information about past ocean circulation changes. Few measurements of Holocene reservoir corrections are available for the climatically important North Atlantic. We determined ΔR for intervals during the past 6100 years before present (BP) by comparing radiocarbon ages of 31 marine and terrestrial sample pairs from 14 archaeological sites from the coast of Ireland, Scotland and the Orkney Islands. We find that, while a time dependency in ΔR for this region cannot be ruled out, within the error of the determinations, the ΔR appears to have been constant for at least the last 2000 and possibly the last 6000 years. This work results in a recommendation for ΔR of 33 +93 for the region.
Stratigraphy, age and formation of peaty earth hummocks (pounus), Finnish Lapland
Authors: Van Vliet-Lanoe Brigitte , Seppala Matti
Published: July 2002

Detailed investigations of peaty earth hummocks called pounus were carried out in northemmost Finnish Lapland in the vicinity of the Kevo Subarctic Research Station. Pounus are complex, often vegetated, cryogenic mounds formed partly of peat. Some have a core of mineral soil or several large stones, or just one frost-heaved boulder covered by peat. They belong to the same group of earth hummocks as thufur and non-sorted circles. The typology of pounus is described and compared with other types of cryogenic earth hummocks. Stratigraphical study of pounus shows how cryoturbation has deformed the previous soil horizons of typical Arctic podzols and has been followed by intense peat growth and later frost reactivation. Microstructures in pounus confirm the frost activity and several phases of peat growth during their formation. Alternating warmer and dryer conditions with water-table rise and renewed peat formation could be inferred. The present stage of development is frost reactivation and peat growth. Pounus are relatively young features. The maximum age for pounu development corresponds with the age of peat formation. Peat of a boulder pounu yielded a data of 330 + 70 BP and a minerogenic pounu gave an age of 710 + 50 BP. The Sphagnum peat formation on peat pounus started intensively about 1000 BP. They are random surficial forms with variable control by frost heave and vegetation growth, independent of the presence or absence of permafrost. They are related to a dynamic snowcover in areas of open birch stands or tundra and their development is polygenetic with alternating frost disturbance and phases of humification or podzolization. Pounus act thermally as a biological refuge in the autumn and spring. At present, perennial frozen cores seem to be common, especially in large peat pounus. Pounu development, as with other earth hummocks, occurs after the main phase of interglacial pedogenesis and can be considered as an indicator of a general cooling trend, developing mostly during the second half of the Holocene. Pounus' relation to climatic change is discussed. Pounus can be considered as an indication of a general cooling trend associated with progressive depletion of summer insolation. Hummock extent is coherent and parallel with trends in permafrost growth, but not directly linked to it.
Buried salt-marsh edges and tide-level cycles in the mid-Holocene of the Caldicot Level (Gwent), South Wales, UK
Authors: Allen J. R. L. , Haslett S. K.
Published: July 2002

Combining stratigraphical, sedimentological and biofacial (foraminifera) approaches, a high-resolution, time-constrained study has been made of a mid-Holocene ( c. 5800–4900 14C yrs BP) estuarine succession ( c. 2 m) continuously exposed for 1.75 km between two major, late-Holocene palaeochannels. The succession displays great lateral variation in bed thickness and facies; bounded by two laterally extensive peats, it consists of silts split by an impersistent, thin peat. A depositional hiatus gradually rises southwestward through the silts from the top of the lower extensive peat to the base of the higher bed, dividing the succession into two depositional sequences. Sequence I, restricted to the southwestern part of the section, ranges from the lower peat to the sharp top of a thin, laterally impersistent, silty peat (cockle-bed peat). It presents vertically symmetrical patterns of texture and environment, broadly from organic marsh and high salt marsh to middle marsh and back to high marsh. Sequence II, overlying the depositional break, is best developed in the northeastern and central parts of the section, beginning in the latter with an erosively based silt (cockle bed) with a life-assemblage of Cardium edule, Hydrobia ventrosa and ostracods. Environmentally, Sequence II is vertically symmetrical only in the northeastern section, where a high salt marsh was succeeded by a low/middle marsh followed by a high marsh overlain by an organic marsh. Asymmetrical patterns of texture and environment prevail in the central section, where the cockle bed appears. Through annually banded deposits that progressively coarsen, a mudflat or low marsh gave way upward to a middle marsh and finally to high and then organic marshes. Sequence I registers a rise of tide level lasting several hundred radiocarbon years. It appears to represent an estuarine marsh with a depositional edge which overlooked to the northeast a largely exposed shelf formed by the lower extensive peat. Sequence II arose much more rapidly, during a further tide-level rise that lasted only 100–200 years. A new marsh formed in the northeastern part of the section, but a wide, brackish, rapidly infilling embayment lay between this marsh and the previous one to the southwest. Differential autocompaction strongly influenced the rate of accumulation of both sequences, creating bed thickness variations of twofold or more. The mid-Holocene estuary experienced subtle, local geographical changes in addition to the gross changes indicated by the silt-peat alternation.
Exposure to low-level chemicals and ionizing radiation: reactive oxygen species and cellular pathways
Authors: Lehnert B E , Iyer R
Published: July 2002

Reactive oxygen species (ROS), which contribute to the energy landscapes in and around cells, play numerous roles in maintaining normal cell homeostasis as components of signaling pathways. Excessively high levels of ROS, on the other hand, can lead to pronounced DNA damage and a variety of cellular responses, including cell cycle arrests, senescence, apoptosis and possibly cancer. Far less is known, however, about how supra-basal levels of ROS that can be generated in response to low doses of ionizing radiation or chemicals in the environment may bring about untoward or perhaps even beneficial cellular responses. Even so, some evidence suggests that adaptive responses that have been associated with ROS-generating stimuli can have protective effects by fundamentally altering subsequent cellular dose-response profiles to otherwise detrimental stresses. Yet, even these seemingly favorable ‘adaptive’ effects may have longer-term untoward consequences. Other effects that have been associated with supra-basal levels of ROS, such as enhanced states of cell proliferation, potentially could have a protective function. But again, such increases in cell growth, which may be accompanied by greater than normal ROS-mediated damage to DNA, as well may ultimately favour the expansion of cells with heritable mutations. Unfortunately, the state of the art of our current understanding of how elevated but still low-level increases in ROS that may be induced by environmental stimuli presently precluded incorporation of supra-basal ROS-associated mechanisms in predictive risk assessment models, both at the population level and at the level of individualized risk assessment.
Unusual neurotoxic envenomations byVipera aspis aspis snakes in France
Authors: de Haro L , Robbe-Vincent A , Saliou B , Valli M , Bon C , Choumet V
Published: July 2002

Vipera aspis aspis (V.a.a.) is the most dangerous poisonous snake in South-Eastern France. The clinical symptoms observed after V.a.a. envenomations involve mostly local signs (pain, edema) associated in the more severe cases with systemic symptoms (gastro-intestinal and cardiovascular manifestations). Since 1992, several unusual cases of moderate and severe `neurotoxic’ envenomations by V.a.a. snakes have been reported in a very localized area in South-Eastern France. Most of the human patients mainly suffered neurological signs owing to cephalic muscle paralysis. Drowsiness and dyspnea were observed for the most severe cases. Envenomed animals suffered respiratory distress and paralysis. The local signs were never as severe as observed after envenomations by vipers in other French regions. Human patients with moderate or severe clinical features received two intravenous injections of Viperfav2 antivenom, the first dose inducing the decrease of the neurological signs and the second reducing significantly the edema. Neurotoxic components immunologically cross-reacting with toxins from V. ammodytes ammodytes venom from Eastern Europe were detected in the blood of all patients suffering neurological symptoms after a V.a.a. bite. The protective efficacy of various antivenoms was evaluated in mice. The existence of geographical variations in the composition of V.a.a. venom emphasizes on the use of polyvalent antivenom in the treatment of viper envenomations in France. Human & Experimental Toxicology (2002) 21, 137 – 145.
Treatment strategies for early presenting acetaminophen overdose: a survey of medical directors of poison centers in North America and Europe
Authors: Kozer E , McGuigan M
Published: July 2002

Background: Acetaminophen is frequently used in self-poisoning in Western countries. Although treatment withN-acetylcysteine (NAC) reduces liver injury, no consensus exists on the preferred management of acetaminophen toxicity. Objectives: To describe the approach taken by toxicologists in North America and Europe toward the management of acetaminophen toxicity. Methods: Medical directors of poison centers in the US, Canada, and Europe were surveyed by means of a questionnaire presenting two clinical scenarios of acetaminophen overdose: a healthy adolescent with no risk factors who had an acute ingestion of acetaminophen, and an adult with both acute ingestion and possible risk factors. For each case, several questions about the management of these patients were asked. Results: Questionnaires were sent to medical directors of 76 poison centers in North America and 48 in Europe, with response rates of 62% and 44%, respectively. Forty percent of responders suggested using charcoal 4 hours after ingestion of a potential toxic dose of acetaminophen, and 90% recommended treatment with NAC when levels were above 150 μg/mL but below 200 μ g/mL 4 hours after ingestion. Duration of treatment with oral NAC ranged from 24 to 96 hours; 38 responders suggested a duration of 72 hours. Of 49 centers recommending oral NAC, 18 (36.7%) said they might consider treatment for less than 72 hours. Eleven of 29 (37.9%) responders suggested treatment with intravenous NAC for more than 20 hours as their usual protocol or a protocol for specific circumstances. Conclusions: Our study showed large variability in the management of acetaminophen overdose. Variations in treatment protocols should be addressed in clinical trials to optimize the treatment for this common problem.
Analysis of repeated events
Authors: Cook R J , Lawless J F
Published: July 2002

Events that may occur repeatedly for individual subjects are of interest in many medical studies. We review methods of analysis for repeated events, emphasizing that the approach taken in a given study should allow clinical questions to be addressed as directly as possible. Methods based on full models for event processes as well as on simpler ‘marginal’ assumptions are considered. The treatment of dependent terminating events related to the recurrent events is also discussed. We apply various methods of analysis to studies involving pulmonary exacerbations in persons with cystic fibrosis, and the occurrence of bone metastases and skeletal events in cancer patients, respectively. Most of the methodology considered can be implemented with existing software.
The SIS and SOE in Norway 1940-1945: Conflict or Co-operation?
Authors: Herrington Ian
Published: July 2002

There is a historical consensus that the Secret Intelligent Services (SIS) and Special Operations Executive (SOE) were from the summer of 1940 locked into a conflict at the highest level, based on rivalry and jealousy, and which at times threatened the very existence of the SOE. It has also been claimed that the operational priority given to the SIS along Norway’s west coast significantly restricted SOE operations into the country. However, examination of the SOE archives now available at the Public Record Office in London and at the Norwegian Resistance Museum in Oslo appear to show that at a sectional and operational level within Norway the relationship between the SOE and SIS was not fraught with the same difficulties. These files also appear to indicate that the SIS operational priority had very little impact on SOE operations. The archives provide numerous examples of co-operation between the two organizations that operated extensively in Norway from the summer of 1940. They exchanged intelligence, shared clandestine radio stations, and used the same fishing boats to transport agents to Norway; several SIS agents moved on to work for the SOE. Both organizations from an early stage, in order to recruit Norwegian agents, were also required to work with the Norwegian authorities based in London. It was a relationship more often built on co-operation than conflict.
Interwar British Experiments with Pilotless Aircraft
Authors: Farquharson John
Published: July 2002

This article assesses British attempts at the production of a viable pilotless aircraft in the 1920s and early 1930s, a scheme initiated by Lord Trenchard as chief of the air staff. There were effectively two ways in which an unmanned plane could be made: either mechanically, by gyroscopic controls, or by radio guidance. Since the second method had scarcely been technically developed at the time, the main emphasis in this account falls on the mechanical model, Larynx. The manufacture and testing of Larynx, both in Britain and in Iraq, are described here, and the reasons for the termination of the experiments in 1936 are discussed. By then piloted bombers were held to be a better option.