bluuebunny/crossref_metadata_2025 huggingface dataset:
The pathophysiology of spasticity
Authors: Sheean G.
Published: March 2003

Spasticity is only one of several components of the upper motor neurone (UMN) syndrome, known collectively as the `positive' phenomena, that are characterized by muscle overactivity. Other components include tendon hyper‐reflexia, clonus, the clasp‐knife phenomenon, flexor and extensor spasms, a Babinski sign, and spastic dystonia. Spasticity is a form of hypertonia due to hyperexcitable tonic stretch reflexes. It is distinguished from rigidity by its dependence upon the speed of the muscle stretch and by the presence of other positive UMN signs. Hyperactive spinal reflexes mediate most of these positive phenomena, while others are due to disordered control of voluntary movement or abnormal efferent drive. An UMN lesion disturbs the balance of supraspinal inhibitory and excitatory inputs, producing a state of net disinhibition of the spinal reflexes. These include proprioceptive (stretch) and nociceptive (flexor withdrawal and extensor) reflexes. The clinical syndrome resulting from an UMN lesion depends more upon its location and extent, and the time since it occurred, than on the pathology of the lesion. However, the change in spinal reflex excitability cannot simply be due to an imbalance in supraspinal control. The delayed onset after the lesion and the frequent reduction in reflex excitability over time, suggests plasticity in the central nervous system. Knowledge of the electrophysiology and neurochemistry of spinal reflexes, together with the action of antispasticity drugs, helps us to understand the pathophysiology of spasticity.
Variation in the management of acute physiological parameters after ischaemic stroke: a European perspective
Authors: Bhalla A. , Tilling K. , Kolominsky‐Rabas P. , Heuschmann P. , Megherbi S. E. , Czlonkowska A. , Kobayashi A. , Mendel T. , Giroud M. , Rudd A. , Wolfe C.
Published: March 2003

Studies have shown significant variation in stroke case fatality across Europe. These variations suggest the need to explore whether differences in physiological support in acute stroke exist across Europe. Data were collected in four European centres over 6 months. These included clinical status and management of acute physiology (hydration, oxygenation, nutrition, hypertension, hyperglycaemia and temperature in the first week of ischaemic stroke) and survival at 3 months. Differences in acute supportive care between centres were adjusted for case mix. Patients admitted to centres in London (n = 106), Dijon (n = 95), Erlangen (n = 91) and Warsaw (n = 72) were studied. There were significant differences in incontinence, dysphasia, dysphagia, conscious level, pyrexia, hyperglycaemia and comorbidity between centres. After adjusting for case mix, there were significant differences in intravenous fluid use (P = 0.04), enteral feeding (P = 0.003), initiation of new antihypertensive therapy (P = 0.0006) and insulin therapy (P = 0.004) between centres, with the London centre having the lowest uptake of interventions. Three‐month case fatality rates varied from 10 to 28%. This pilot study shows significant variation in acute physiological support in acute stroke across four European centres, which remains unexplained by case mix. Further research is required to link variation in acute care with stroke outcome, to identify which interventions appear to be the most effective.
Neurological disorders associated with Mycoplasma pneumoniae infection
Authors: Sotgiu S. , Pugliatti M. , Rosati G. , Deiana G. A. , Sechi G. P.
Published: March 2003

Neurological syndromes caused by Mycoplasma pneumoniae (MP) infection are occasionally reported in adults, usually in the post‐infectious period, and three computed tomography documented cases have recently appeared in this journal. Here we present the cases of three young women with recent respiratory tract infection caused by MP some weeks prior to neurological complication documented by magnetic resonance imaging. Two cases suffered from demyelinating disorders of the central nervous system (CNS). The other case had a middle cerebral artery thrombosis, a rare complication of MP infection. Another potential risk factor for stroke in the latter case was the use of oral contraceptives. Recent infection with MP is discussed as a risk factor for cerebrovascular disorders and CNS demyelinating diseases.
The Role of Estrogen in Migraine: A Review and Hypothesis
Authors: Welch KMA , Darnley Deborah , Simkins Robert T
Published: March 2003

The epidemiological, clinical and basic science evidence for a role of estrogen in migraine is reviewed. The hypothesis is put forward that estrogen exerts its influence by modulating sympathetic control of the cerebral vasculature.
Epidermoid Tumour of the Posterior Fossa Causing Multiple Facial Pain a Case Report
Authors: Levyman Célio , Filho Americo dos Santos Poça Dagua , Volpato Margarete Mota , Settanni Flavio Aurelio Parente , Lima Wanderley Cerqueira de
Published: March 2003

A 53-year-old woman presented with three types of pain. The pains had characteristics of neuralgia of the fifth cranial nerve, ninth cranial nerve, and cluster headache. On further investigation, a tumour in the posterior fossa was observed and histologically shown to be an epidermoid tumour.
Migraine With Aura and Migraine Without Aura: An Epidemiological Study
Authors: Rasmussen Birthe Krogh , Olesen Jes
Published: March 2003

In a cross-sectional study of headache disorders in a representative general population of 1,000 persons the epidemiology of migraine with aura (MA) and migraine without aura (MO) was analysed in relation to sex and age distribution, symptomatology and precipitants. The headache disorders were classified on the basis of a clinical interview as well as a physical and a neurological examination using the operational diagnostic criteria of the International Headache Society (IHS). Lifetime prevalence of MA was 5%, male:female ratio 1:2. Lifetime prevalence of MO was 8%, M:F ratio 1:7. Women, but not men, were significantly more likely to have MO than MA. Neither MA nor MO showed correlation to age in the studied age interval (25–64 years). Premonitory symptoms occurred in 16% of subjects with MA and in 12% with MO. One or more precipitating factor was present in 61% with MA and in 90% with MO. In both MA and MO the most conspicuous precipitating factor was stress and mental tension. Visual disturbances were the most common aura phenomenon occurring in 90% of subjects with MA. Aura symptoms of sensory, motor or speech disturbances rarely occurred without coexisting visual disturbances. The pain phase of MA fulfilled the criteria for MO of the IHS. Headache was, however, less severe and shorter lasting in MA than in MO. Onset at menarche, menstrual precipitation, menstrual problems, influence of pregnancy and use of oral contraceptives all showed some relationship with the presence of MO and less with MA. The present findings suggest that MA and MO share the pain phase. Among subjects with MA and MO, 50% and 62%, respectively, had consulted their general practitioner because of migraine. Selection bias in previous clinical studies is demonstrated by comparisons with the present unselected sample.
Twenty-Four-Hour Melatonin and Cortisol Plasma Levels in Relation to Timing of Cluster Headache
Authors: Leone M , Lucini V , D'Amico D , Moschiano F , Maltempo C , Fraschini F , Bussone G
Published: March 2003

The cyclic recurrence of cluster periods and the regular timing of headache occurrence in cluster headache (CH) induced us to study the circadian secretion of melatonin and cortisol in 12 patients with episodic CH, during a cluster period, and compare them with 7 age- and sex-matched healthy controls. Blood was sampled every 2, h for 24 h. All subjects were confined to a dark room from 22.00 to 08.00. Plasma melatonin levels were significantly reduced in CH patients (repeated measures ANOVA p < 0.03; mesor p < 0.02), and the cortisol mesor was significantly increased ( p < 0.03). Amplitudes and acrophases did not differ between the groups. Individual cosinor analysis showed that 4/12 (33.3%) CH patients had no significant melatonin rhythm, and that 5/11 (45.5%) had no cortisol rhythm. Group analysis of cosinor revealed significant rhythmicity of melatonin and cortisol secretion in both groups. In controls, the timing of melatonin and cortisol acrophase significantly correlated with each other, indicating that the biorhythm controllers for the secretion of these hormones were synchronized. Such correlation was not found in the CH patients; mesor, amplitude and acrophase of melatonin and cortisol did not correlate with duration of illness, duration of headache in course, or time since last headache attack.
Headache as A Surrogate Marker of the Molecular Mechanisms Implicated in Progressing Stroke
Authors: Leira R , Dávalos A , Aneiros á , Serena J , Pumar JM , Castillo J
Published: March 2003

The mechanism for headache in patients with acute ischaemic stroke are not completely understood. We analysed the relationship between headache and the early worsening of neurological symptoms in patients with acute ischaemic stroke, and we studied the possible biochemical mechanisms implicated. Headache at the onset of ischaemic stroke predicted progression with a sensitivity, specificity, and positive predictive value of 56%, 99%, and 98%, respectively. CSF concentrations of glutamate, Interleukin-6, and NO-m were significantly greater in patients with progressing stroke than in patients with nonprogressing stroke, and these biochemical markers were also significantly higher in patients with headache than in those without headache. Results of this study suggest that headache at the onset of ischaemic stroke is an independent predictor of neurological worsening and we hypothesize that headache might be a surrogate marker of the molecular mechanisms involved in neurological worsening after acute stroke.
Dementia in people with learning disability: a preliminary study into care staff knowledge and attributions
Authors: Whitehouse Richard , Chamberlain Paul , Tunna Kate
Published: March 2003

The present paper describes the findings of a pilot study funded by the NHS Executive Primary and Community Care Research Initiative Small Projects Scheme that investigated the knowledge and attributions of dementia held by care staff who work with older adults with learning disability. Meetings took place with 21 members of care staff identified as keyworkers to older adults with learning disability living in residential houses provided by Solihull Healthcare NHS Trust, Solihull, UK. The results suggest that staff have knowledge of ageing at a similar level to that of college students. Forgetfulness was the sign that they would most expect to see if they thought someone was suffering from dementia. When a change in behaviour was attributed to dementia, it was most likely to be viewed as ‘stable, uncontrollable’ with staff feeling pessimistic about being able to change the behaviour.
Over the top? Reducing staff training in physical interventions
Authors: Kaye Neil , Allen David
Published: March 2003

The use of emergency physical interventions on an acute admission unit for persons with learning disability and challenging behaviour was monitored over a 9‐month period. Only a minority of the physical interventions that were taught to staff were actually used in practice. Possible reasons for this discrepancy are discussed, and a number of potential sources of bias in estimating the original training requirements for the service identified. Implications for changing the training programme are described.
Petroleum infiltration of high‐grade basement, South Norway: Pressure‐Temperature‐time‐composition (P–T–t–X) constraints
Authors: Munz I. A. , Yardley B. W. D. , Gleeson S. A.
Published: March 2003

Fluid inclusion data provide pressure–temperature–time–composition (P–T–t–X) constraints for an episode of petroleum infiltration of the crystalline basement in South Norway. Petroleum inclusions associated with pyrobitumen occur in postmetamorphic quartz veins in the Modum Complex. Three groups of fluid compositions have been shown, ranging from CH4 ± CO2 to condensates with alkanes up to C15. The range in fluid composition is a result of petroleum decomposition at high temperature. Globular and massive pyrobitumen occurs in the quartz veins or in associated vein systems. Reflectance (%Rm) measurements of 3.20–3.35 correspond to a maximum temperature of 207–214°C for the pyrobitumen associated with group II and III inclusions. Geothermometry of chlorites included in the quartz show results of 226–231°C. Pressure conditions of trapping for all three groups of inclusion fluids have been estimated to 520–985 bar at 220°C. The pressure range is probably a result of fluctuations caused by repeated fracture opening and sealing due to seismic activity coupled with mineral growth. A lack of systematic textural relationships between the three groups of inclusions and similar pressure–temperature estimates for all fluid types indicate trapping at similar times and a process of rapid change. Fluid migration in fractures from an overlying, overpressured sedimentary basin into a dry, crystalline basement best explains the observed P–T–t–X constraints.
The role of patch area and habitat diversity in explaining native plant species richness in disturbed suburban forest patches in northern Belgium
Authors: Honnay O. , Endels P. , Vereecken H. , Hermy M.
Published: March 2003

Relatively easy measurable patch characteristics (especially habitat diversity measures) have proven to be valuable indicators of forest plant species richness in forest fragments of relatively undisturbed areas. Urban and suburban forest patches, however, are characterized by a specific landscape ecological context implying that specific processes may influence ecosystem functioning and hence that other abiotic indicators for plant diversity are more appropriate. We studied the relation between functional ecological plant species groups and suburban forest patch characteristics such as patch area, habitat diversity and isolation. Some components of species richness were related to the isolation of the patches. In contrast to previous similar large‐scale fragmentation studies in more rural areas, further results stressed the overwhelming importance of patch area relative to habitat variables in determining species richness. This suggests (1) the occurrence of density‐dependent species extinction processes in small forest patches; or (2) the existence of external deterministic factors which put a major constraint on species richness in small patches. We tend to support the latter hypothesis and propose forest disturbance and associated black cherry (Prunus serotina Ehrh.) invasion as such a possible external factor. Small forest patches may be more sensitive to disturbance and biological invasion due to various reasons. Hence large forest patches are to be preferred for plant conservation in the suburban area.
The impact of the invasive alien grass Cortaderia jubata (Lemoine) Stapf on an endangered mediterranean‐type shrubland in California
Authors: Lambrinos John G.
Published: March 2003

Abstract. Since its introduction in the late 1800s, the perennial tussock grass Cortaderia jubata (Lemoine) Stapf has become an increasingly frequent member of coastal plant communities in California and Oregon. In this study, the community changes associated with C. jubata invasion into the mediterranean‐type vegetation of Vandenberg Air Force Base, California were examined. Pristine plots of maritime chaparral were compared with spatially and topographically matched plots dominated by C. jubata. Aerial photographs indicated that the invaded plots had previously been shrubland. C. jubata invasion created a structurally less complex perennial grassland that was markedly depauperate in native shrub species. The absence of native shrubs depressed native richness in jubata grassland, but the greater richness of both native and alien herbaceous species made overall richness in jubata grassland indistinguishable from maritime chaparral. Vegetational differences were associated with differences in arthropod and small mammal populations between vegetation types. Arthropod abundance and order diversity were lower in plots dominated by C. jubata than in adjacent chaparral. Insect traps in C. jubata plots contained a significantly smaller proportion of Hymenoptera and Homoptera and a significantly greater proportion of Aràneae than traps in maritime chaparral. Rodent activity was significantly lower while rabbit activity was significantly greater in jubata grassland compared to maritime chaparral. This study indicates that the presence of C. jubata can dramatically alter the mediterranean‐type landscape of central California. While it is likely that the initial establishment of C. jubata is associated with disturbances that are common in this ecosystem, the ability of C. jubata to expand from founding populations and to persist for long periods of time pose a serious threat to the native diversity of these unique systems.
Species richness and endemism of plant and bird communities along two gradients of elevation, humidity and land use in the Bolivian Andes
Authors: Kessler Michael , Herzog Sebastian K. , Fjeldså Jon , Bach Kerstin
Published: March 2003

We studied the patterns of species richness and range–size rarity (as a measure of endemism) of two plant groups (Pteridophyta, Bromeliaceae) and birds along two gradients of elevation, humidity and human land use in a forested Andean valley. Both transects covered the transition from an arid valley bottom through a cloud forest zone to relictual high‐elevation Polylepis forest, but transects differed in overall precipitation. Plants were surveyed in 88 plots of 400 m2 each, while birds were detected primarily through visual observations and tape recordings over areas of 0.3–1.5 km2. Global range sizes of all species were mapped on 1°‐grids and range‐size rarity was calculated as the mean inverse range size of all species recorded in elevational steps of 200 m. Patterns of species richness and range–size rarity were mainly unrelated between and within study groups. Monotonic increases and decreases and hump‐shaped patterns were observed for species richness as well as range–size rarity. Several of these patterns can be interpreted in the light of the ecological requirements of each taxonomic group, e.g. dependence of fern species richness on humidity or of bird richness on habitat complexity. Species richness of ferns and birds peaked at higher elevations along the less rainy transect, possibly as a result of higher levels of solar radiation and ecosystem productivity. Patterns of species richness and endemism of the study groups are causally unrelated and cannot be used to predict those of other groups at the spatial scale of this study. Human impact was highest in areas of mostly low to intermediate species richness, but was often high in zones of high endemism.
Differential rates of invasion in three related alien oak gall wasps (Cynipidae: Hymenoptera)
Authors: Walker P. , Leather S. R. , Crawley M. J.
Published: March 2003

Abstract. Three related species of oak gall wasps,Andricus corruptrix(Schlechtendal),A. kollari(Hartig) andA. lignicola(Hartig) have entered Britain since the introduction of Turkey oak,Quercus cerrisL. in 1735. Their lifecycles involve alternating generations between an agamic generation on the native oak species (Q. petraea,Q. robur andtheir hybridQ. x. rosacea), and a smaller, sexual generation on the alienQ. cerris. In examining the distributions of these insects andQ. cerris, we hypothesized that: (1) the invasion will spread more rapidly in places where both host trees are equally abundant than through regions where one of the tree species is substantially less common than the other; (2) interspecific competition between these bud‐galling species will lead to a negative correlation between their abundances at a particular site; (3) differential recruitment of natural enemies from the native hymenopteran fauna will slow the rate of spread in a species‐specific manner.A. kollariarrived nearly 200 years ago and is now found throughout the British Isles, wherever Turkey oak is grown.A. lignicolaandA. corruptrixhave been here for 30 years, after establishing in S.E. England.A. lignicolais in its final rapid stages of range expansion across England, southern Scotland and N.E. Scotland.A. corruptrixis just beginning to spread through Central and S.W. England. It has occupied proportionally fewer sites behind its invasion front than have the other two species, but is no less abundant at these sites. Nevertheless, distance leaps of up to 50 km were identified inA. lignicolain N.E. Scotland, and the possibility of long‐distance transport of infected trees through the horticulture and forestry trades remains. The co‐occurrence of mature individuals of both hostQuercusspecies does appear to have increased their rates of colonization inA. lignicolaandA. corruptrix. There is no evidence, however, to suggest that interspecific competition between the three alien gall formers is an important factor in determining their distributions and abundance within their invaded ranges. All three species have recruited parasitoids and inquilines rapidly from the native fauna; attack rates were highly variable, but showed no evidence of density dependence across sites.
Grazing and community structure as determinants of invasion success by Scotch broom in a New Zealand montane shrubland
Authors: Bellingham P. J. , Coomes D. A.
Published: March 2003

Abstract. Scotch broom (Cytisus scoparius (L.) Link; Fabaceae) is a problematic invasive plant in many countries, and while attention has been paid to traits that make it a successful invader, there has been less focus on the properties of ecosystems that it invades. We conducted an experiment in a New Zealand montane shrubland with tussock grasses that has been invaded by Scotch broom to determine features that rendered it susceptible to invasion. We planted broom seedlings into the shrubland (control) and into three treatments: (1) resident shrubs removed, (2) tussocks removed and (3) shrubs and tussocks removed. We measured broom seedling mortality and growth over two growing seasons. The site was grazed by sheep in the first season, and scarcely grazed in the second, wetter season. Survivorship across all treatments after 19 months was 42%, and was lowest where shrubs were retained but tussocks removed. Broom seedlings grew taller and had greater leaf areas in treatments that retained shrubs. Neighbouring (within 49 cm) shrubs had no effects on survivorship or growth of broom seedlings. Neighbouring tussocks increased survivorship of broom seedlings but depressed their growth. Grazing by sheep was the most important determinant of survivorship and growth of broom seedlings, and effects were uniform regardless of experimental treatments. Initial high mortality of seedlings (48% in the first 3 months) was due to grazing, and height growth was often negative during periods of grazing. In the second growing season when the site was less grazed and there was greater rainfall, there was a rapid increase in height across all treatments. Continued grazing of the site by sheep is likely to be the chief means of retarding the invasion.
Large‐scale terrestrial gastropod community composition patterns in the Great Lakes region of North America
Authors: Nekola Jeffrey C.
Published: March 2003

Abstract:Previous ordination studies of land snail community composition have been limited to four or fewer habitat types from sites separated by no more than 300 km. To investigate the nature of large‐scale patterns, North American land snail assemblages at 421 sites, representing 26 habitat types and covering a 1400 × 800 km area, were ordinated using global, nonmetric multi‐dimensional scaling (NMDS). These data were then subjected to model‐based cluster analysis and kmeans clustering to identify the main compositional groups and most important environmental covariables. Six primary compositional groups were identified. Three of these largely represent upland forest and rock outcrop sites, while the remaining largely represent either lowland forest, lowland grassland or upland grassland habitats. The geographical location and moisture level of sites also influences community composition. A strong compositional difference exists between sites having duff vs. turf soil surface layers. Only 8% of sites were improperly classified when soil surface architecture was used as the sole predictor variable. Fully 43% of taxa exhibited significant preferences towards one of these surface types, while only 15% of relatively common (10 + occurrence) taxa showed no preferences. Twelve groups of closely related taxa within the same genus had members that favoured different surface types, indicating that differential selection pressures have existed over evolutionary time scales. While turf faunas appeared unaffected by anthropogenic disturbance, duff faunas were strongly impacted, suggesting that their conservation will require protection of soil surface architecture.
Potentiation by nitric oxide synthase inhibitor and calcium channel blocker of aspartame‐induced antinociception in the mouse formalin test
Authors: Abdollahi Mohammad , Nikfar Shekoufeh , Abdoli Narges
Published: March 2003

By applying a 12 day regimen of the non‐calorific sweetener, aspartame, in combination with representative compounds of the calcium channel blocker and nitric oxide synthase inhibitor, we tried to investigate using a formalin‐test in mice the relative role of aspartame on pain and its mechanism of action. Verapamil (2, 3.5, 5, 7.5 mg/kg) induced significant (P < 0.01) antinociception in both phases of the formalin test. L‐Nitro‐arginine‐methyl‐ester (L‐NAME) at the doses used, induced significant (P < 0.01) antinociception in early phase (1, 2, 5, 10 mg/kg) and late phase (5, 10 mg/kg). Twelve days of treatment in animals by aspartame (0.16% w/v) significantly induced antinociception in both phases of the formalin test. Both verapamil (5 mg/kg) and L‐NAME (10 mg/kg) significantly (P < 0.01) potentiated aspartame‐induced antinociception in both phases of formalin test. The present findings support the hypothesis that the activation of NMDA receptors by aspartame modulates pain‐related behaviour via a nitric oxide/cGMP/glutamate release cascade. It is concluded that aspartame would be a good analgesic agent if it would be used in combination with a calcium channel blocker or NOS inhibitor.
Effect of endogenous catecholamine on myocardial stunning in a simulated ischemia model
Authors: Ishiguro Yoshiki , Morgan James P.
Published: March 2003

During ischemia, large amounts of catecholamine are released to the myocardium from the sympathetic nerve endings in the heart. It has not been clearly shown whether the released catecholamine has detrimental or beneficial effects on postischemic myocardial contractile function. The aim of the present study was to investigate the effect of endogenous catecholamine released during ischemia on myocardial contractile function, using ferret papillary muscles in a stimulated ischemia model.

Papillary muscles were excised and mounted in organ baths containing oxygenated physiological salt solution at 37 °C. In order to eliminate the effect of endogenous catecholamine, a subset of animals was reserpinized for 2 days prior to the experiments. Muscles were stabilized for 1 h, and stretched to the length at which maximal isometric tension developed. Ischemia was simulated by changing the solution to liquid fluorocarbon bubbled with 95% N2 and 5% CO2. After 20 min of ischemia, the bathing medium was replaced with oxygenated physiological salt solution and developed tension was measured for 60 min. Pharmacologic agents with specific effects on myocardial autonomic pathways were used to investigate the cellular mechanisms of the observed effects.

Tension recovery of reserpinized muscles was significantly better than control muscles (65.5 ± 2.8% vs. 54.9 ± 5.0%, P < 0.01). Exogenously administered β‐adrenergic antagonists did not attenuate stunning in control muscles; whereas forskolin and carbachol exacerbated stunning.

These results indicate that catecholamine released during ischemia exacerbates myocardial stunning and overrides the effect of clinically relevant concentrations of β‐adrenergic antagonists, which may limit their ability to protect myocardium from acute ischemic insult. The effect of endogenous catecholamine was simulated by forskolin, but not attenuated by carbachol, which suggests that changes in the contractile apparatus activated by excess cyclic AMP were relevant to the mechanical dysfunction that developed.
Inflammation, infection and antimicrobial therapy in coronary heart disease – where do we currently stand?
Authors: Ngeh Joseph , Gupta Sandeep
Published: March 2003

Traditional atherosclerotic risk factors such as hypertension, smoking, hyperlipidaemia and diabetes mellitus, account for only about 50% of the clinical occurrence of coronary heart disease (CHD). The infectious hypothesis proposes that various microorganisms, in particular, Chlamydia pneumoniae, may serve as potential etiological factors, linking inflammation and atherosclerosis (or its clinical manifestations). Evidence from seroepidemiology, pathology, animal models, molecular biology and immunology, and human antibiotic intervention studies, collectively have suggested a largely positive association between C. pneumoniae infection and CHD. As CHD is a multifactorial disease, it is possible that C. pneumoniae may interact with conventional cardiovascular risk factors and predispose certain genetically susceptible people to atherosclerotic disease. However, the precise nature of a causal or coincidental link between C. pneumoniae and CHD remains to be determined. The results of ongoing antibiotic intervention studies may help to further clarify the role of infection and inflammation in CHD, but until such a role is proven beyond reasonable doubt, antimicrobial therapy cannot yet be justified in the treatment or prevention of CHD. A current perspective is presented in this review.
Influence of Trimetazidine on the synthesis of complex lipids in the heart and other target organs
Authors: Sentex E. , Héliès‐Toussaint C. , Rousseau D. , Lucien A. , Ferrary E. , Grynberg A.
Published: March 2003

Trimetazidine exerts antianginal properties at the cellular level, without haemodynamic effect in clinical and experimental conditions. This cytoprotection was attributed to a decreased utilization of fatty acids for energy production, balanced by an increased incorporation in structural lipids. This study evaluated the influence of Trimetazidine on complex lipid synthesis from [2‐3H] glycerol, in ventricular myocytes, isolated rat hearts and in vivo in the myocardium and several other tissues. In cardiomyocytes, Trimetazidine increased the synthesis of phosphatidyl‐choline (+ 80%), phosphatidyl‐ethanolamine (+ 210%), phosphatidyl‐inositol (+ 250%) and cardiolipid (+ 100%). The common precursor diacylglycerol was also increased (+ 40%) whereas triacylglycerol was decreased (−70%). Similar results were obtained in isolated hearts with 10 μM Trimetazidine (phosphatidyl‐choline + 60%, phosphatidyl‐ethanolamine + 60%, phosphatidyl‐inositol + 100% and cardiolipid + 50%), the last two phospholipids containing 85% of the radioactivity. At 1 μM, Trimetazidine still stimulated the phospholipid synthesis although the difference was found significant only in phosphatidyl‐inositol and cardiolipid. In vivo studies (10 mg/kg per day for 7 days and 5 mg/kg, i.p. before the experiment) revealed significant changes in the intracellular lipid biosynthesis, with increased labelling of phospholipids and reduced incorporation of glycerol in nonphosphorous lipids. Trimetazidine increased the glycerol uptake from plasma to the other tissues (liver, cochlea, retina), resulting in an altered lipid synthesis. The anti‐anginal properties of Trimetazidine involve a reorganisation of the glycerol‐based lipid synthesis balance in cardiomyocytes, associated with an increased uptake of plasma glycerol that may contribute to explain the pharmacological properties reported in other organs.
Relationships between the antihypertensive effects of bisoprolol and levels of plasma atrial natriuretic peptide in hypertensive patients
Authors: Baláti Beáta , Phung Henry , Pousset Françoise , Isnard Richard , Boisvieux Anne , Carayon Alain , Komajda Michel , Lechat Philippe
Published: March 2003

Previous studies have demonstrated that beta‐blockade increases the levels of plasma atrial natriuretic peptide (ANP), but relationships between this effect and the antihypertensive action of beta‐blockade remain unknown. In this study we investigated the amplitude and determinants of bisoprolol‐induced ANP increase and the relationships between this increase and the antihypertensive effect of bisoprolol. Nineteen patients with mild to moderate hypertension were included in the study. In the first phase of the study (cross‐over, placebo controlled, randomized phase), the effects of 10 mg bisoprolol on plasma ANP at rest and during exercise were compared to placebo. The antihypertensive action of bisoprolol was then evaluated after a 2‐week period of treatment (10 mg/day) using ambulatory blood pressure monitoring. Bisoprolol significantly increased plasma ANP level at rest (from 30.6 ± 20.5 to 42.8 ± 35.6; P < 0.05) and also during exercise (from 54.7 ± 44.3 to 119.1 ± 159.9; pg/mL ± SD; P < 0.05). Plasma ANP at rest was not significantly correlated with left ventricular mass. After the 15 days of treatment, the bisoprolol‐induced daytime diastolic blood pressure reduction was significantly correlated to the initial bisoprolol‐induced plasma ANP increase (r=0.49, P=0.035). These results suggest that the antihypertensive effect of beta‐blocking agents could be partly mediated by an increase of ANP release.
Determination of enalapril and enalaprilat by enzyme linked immunosorbent assays: application to pharmacokinetic and pharmacodynamic analysis
Authors: Matalka Khalid , Arafat Tawfiq , Hamad Mohammad , Jehanli Ahmed
Published: March 2003

We have developed two enzyme linked immunosorbent assay (ELISA) methods for determining enalapril and enalaprilat in plasma. In this study, 48 healthy subjects received an oral dose of either 10 or 20 mg of enalapril and plasma concentrations of enalapril and enalaprilat were determined by their specific ELISA methods. These plasma concentrations and blood pressure measurements were applied to evaluate the pharmacokinetic (PK) and pharmacodynamic (PD) parameters of both enalapril and enalaprilat. The enalapril values for the area under the curve (AUC0→∞) were 480 ± 216 and 832 ± 325 ngh/mL, maximum plasma concentrations (Cmax) were 310 ± 187 and 481 ± 185 ng/mL, and times required to reach the maximum concentration (tmax) were 1.13 ± 0.22 and 1.09 ± 0.33 h for 10 and 20 mg doses, respectively. The enalaprilat values for AUC0→∞ were 256 ± 122 and 383 ± 158 ngh/mL, Cmax values were 57 ± 29 and 72.9 ± 33.6 ng/mL and tmax values were 4.28 ± 1.45 and 4.05 ± 01.22 h for 10 and 20 mg doses, respectively. The Cmax values of enalapril were ∼10 times higher than those in the literature, which were determined by angiotensin converting enzyme (ACE) inhibition assays following alkaline hydrolysis, but similar to those of enalaprilat. The PD profiles revealed a significant correlation between enalaprilat concentrations in plasma and the decrease in systolic and diastolic blood pressures (r=−0.95 with P < 0.001 and r=−0.95 with P < 0.001), respectively, following a single oral dose of enalapril. These ELISA methods have the advantage of being simple, accurate, sensitive, and do not depend on enalaprilat binding to ACE. Such methods can be used for analysis and kinetic testing of enalapril and enalaprilat in biological fluids.
Taichiquan acutely increases heart rate variability
Authors: Väänänen Janne , Xusheng Sun , Wang Shixuan , Laitinen Tomi , Pekkarinen Heikki , Länsimies Esko
Published: March 2003

A group of 15 elderly men and 14 young male students of physical education made twice a series of Taichiquan (TCQ) practices. Their electrocardiograms were recorded on tape‐recorder and heart rates and heart rate variability (HRV) were calculated from digitized data. Here we report the results of recordings in supine positions before and after the first and second series of TCQ. Intervals between heart beats (RRIs) and their standard deviation (SDNN) increased in older men from recordings before the exercise to postexercise. In young subjects the SDNN and total variance (TV) of RRIs increased. HRV increases immediately after TCQ‐exercise in young and old male healthy subjects. Whether these practices have permanent effects and effects in patients need controlled and prospective studies.
Oxygen desaturation during oesophageal manometry
Authors: Walamies Markku A.
Published: March 2003

Eighteen generally fit clinical patients were monitored with pulse oximetry. Mean oxygen saturation levels were lower (P<0·05) during oesophageal manometry (97·7–97·3%) than before it (98·3%). Fourteen out of seventeen (successful) traces had short 4–8% desaturation episodes, and in worst cases there were 8–9 episodes. It seems, therefore, that even patients with no predisposing factors than perhaps smoking and mild bronchial asthma are vulnerable to some oxygen desaturation in oesophageal manometry.
Effects of athletic training on heart rate variability triangular index
Authors: Kouidi E. , Haritonidis K. , Koutlianos N. , Deligiannis A.
Published: March 2003

The purpose of this study was to assess the heart rate variability triangular index (HRVI) in elite track and field athletes. Sixty healthy males (mean aged 22·1 ± 3·5 years) −15 long distance runners (group A), 15 speed runners (Group B), 15 throwers (Group C) and 15 non‐trained subjects (Group D) were submitted to spiroergometric test, m‐mode echocardiography and 24‐h ambulatory ECG monitoring. The HRVI, mean heart rate, mean interval between two consecutive R waves of the QRS complexes (R–R interval) and standard deviation of the R–R (SDRR) were assessed through time domain method on computed 24‐h Holter recordings. The HRVI and the SDRR were 62·2 ± 9·6 and 220 ± 40 ms correspondingly in group A, 52·7 ± 6·0 and 210 ± 40 ms in B, 44·5 ± 5·3 and 180 ± 40 ms in C, 39·3 ± 6·4 and 180 ± 30 ms in D. The HRVI and the mean R–R were found to differ statistically between groups A, B and C versus D (P<0·05). However, the higher value in HRVI was found in group A. Maximal oxygen consumption (VO2max) was 62·0 ± 4·4 ml kg−1 min−1 in group A, 52·7 ± 6·0 in group B, 44·6 ± 5·3 in C and 41·6 ± 6·0 in D. The higher value in VO2max was also found in group A. The left ventricular mass index (LVMI) and end‐diastolic volume index (EDVI) were 136 g m−2 and 83 ml m−2 correspondingly in group A, 136 and 79 in B, 124 and 56 in C and 88 and 55 in group D. The HRVI was found to have a significant relationship with VO2max and EDVI only in group A. On the other hand, no significant relationships were found between HRVI and LVMI in all groups. It is concluded, that the enhanced HRVI in athletes is affected by exercise training pattern. Moreover, HRVI depends on the level of VO2max in endurance‐trained, but is independent from the extent of myocardial hypertrophy in all types of training.
Effect of standing on short term heart rate variability across age
Authors: Srinivasan K. , Sucharita S. , Vaz Mario
Published: March 2003

This study examined the response of heart rate variability measures to standing in three age groups of male subjects: Children (6–11 years), young adults (20–30 years) and elderly (60–70 years). Supine and standing heart rate variability indices were measured in all the subjects using power spectral analysis. The effect of posture on heart rate variability was assessed using the change in heart rate variability measures over resting values during the first 2 min following active standing. There was an attenuated response in normalized low frequency (LF) and high frequency (HF) power to standing in the elderly as compared with young adults and children. Heart rate variability responses to standing were highest in the young adults, followed by the children and the elderly, although the differences between the young adults and children were not significant. More studies are needed to characterize HRV responses to posture in children.
Techno‐Arrogance and Halfway Technologies: Salmon Hatcheries on the Pacific Coast of North America
Authors: Meffe Gary K.
Published: March 2003

Humankind has adopted an arrogant and ultimately self‐defeating attitude toward nature that places technological mastery over nature at the forefront of our approach to many environmental problems. This “techno‐arrogance” fails to recognize limitations on, and ramifications of, attempted control of nature. An example of techno‐arrogance is the flawed attempt to recover Pacific salmonid fisheries through technological application in the form of hatcheries. Countless salmon stocks have declined precipitously over the last century as a result of overfishing and widespread habitat destruction. A central feature of recovery efforts has been to build many hatcheries to produce large quantities of fish to restock streams. This approach addresses the symptoms but not the causes of the declines (an example of a halfway technology), because the habitats remain largely unsuitable for salmon. There are at least six reasons why the hatchery approach will ultimately fail: (1) data demonstrate that hatcheries are not solving the problem—salmon continue to decline despite decades of hatchery production; (2) hatcheries are costly to run, and divert resources from other efforts, such as habitat restoration; (3) hatcheries are not sustainable in the long term, requiring continual input of money and energy, (4) hatcheries are a genetically unsound approach to management that can adversely affect wild populations; (5) hatchery production leads to increased harvest of declining wild populations of salmon; and (6) hatcheries conceal from the public the truth of real salmon decline. I recommend that salmonid management turn from the symptoms to the causes of decline. Overharvest and habitat destruction must be directly addressed in a major, landscape‐level effort, on a scale comparable to the hatchery program, if salmonid fisheries are to remain a part of the ecological recreational, commercial and asthetic arenas in the long term.
Natural Capital and Sustainable Development
Authors: COSTANZA ROBERT , DALY HERMAN E.
Published: March 2003

Abstract: A minimum necessary condition for sustainability is the maintenance of the total natural capital stock at or above the current level. While a lower stock of natural capital may be sustainable, society can allow no further decline in natural capital given the large uncertainty and the dire consequences of guessing wrong. This “constancy of total natural capital” rule can thus be seen as a prudent minimum condition for assuring sustainability, to be relaxed only when solid evidence can be offered that it is safe to do so.

We discuss methodological issues concerning the degree of substitutability of manufactured for natural capital, quantifying ecosystem services and natural capital, and the role of the discount rate in valuing natural capital. We differentiate the concepts of growth (material increase in size) and development (improvement in organization without size change). Given these definitions, growth cannot the sustainable indefinitely on a finite planet. Development may be sustainable, but even this aspect of change may have some limits. One problem is that current measures of economic well‐being at the macro level (i.e., the Gross National Product) measure mainly growth, or at best conflate growth and development. This urgently requires revision.

Finally, we suggest some principles of sustainable development and describe why maintaining natural capital stocks is a prudent and achievable policy for insuring sustainable development. There is disagreement between technological optimists (who see technical progress as eliminating all resource constraints to growth and development) and technological skeptics (who do not see as much scope for this approach and fear irreversible use of resources and damage to natural capital). By maintaining natural capital stocks (preferably by using a natural capital depletion tax), we can satisfy both the skeptics (since resources will be conserved for future generations) and the optimists (since this will raise the price of natural capital depletion and more rapidly induce the technical change they predict).
Has Pine Growth Declined in the Southeastern United States?*
Authors: ZEIDE BORIS
Published: March 2003

Abstract:The United States Forest Service inventory specialists discovered that since 1972 a significant decline has occurred in growth of natural pine stands in the southeastern United States. This decline was puzzling because neither internal nor external changes in stand conditions were a sufficient explanation. Nor did related observations help solve the puzzle: pine plantations in the same region showed no growth reduction; the decline was not associated with an increased level of pollution; no excessive loss of needles or change in needle coloration were found. Reexamination of the original inventory data that included the latest, third, growth period revealed that high basal area increments during 1961–72 were due to abnormally low basal areas at the 1961 inventory (third inventory). These data suggest forest decline prior to 1961, rather than after this date. A more plausible explanation is the deficiency of the data especially that collected during the third inventory when, for the first time, point sampling was used instead of fixed area plots. An analysis of increments from remeasured plots, numerous outliers, and inconsistencies in relationships between other variables raise further questions about the validity of the data. It seems that the reported forest decline is an artifact of shifting inventory protocols, the complexities of point sampling, and faulty treatment of the data. We need to know the true state of the nation's forests—both over‐estimates and under‐estimates of decline ultimately defeat sound management. My analysis concludes with the following suggestions for a revision of the Forest Service inventory system: incorporate forest inventory into the wider framework of Geographic Information Systems (GIS); make forest inventory useful to practicing foresters and not just to regional or national planners; use fixed area methods instead of point sampling; establish external quality control and quality assurance procedure, and develop procedures that take into account mutual correlation among plots by utilizing concepts of geostatistics, spatial analysis, and time series analysis.