882 resultados para Ineffective Nodulation


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Neurons in pelvic ganglia receive nicotinic excitatory post-synaptic potentials (EPSPs) from sacral preganglionic neurons via the pelvic nerve, lumbar preganglionic neurons via the hypogastric nerve or both. We tested the effect of a range of calcium channel antagonists on EPSPs evoked in paracervical ganglia of female guinea-pigs after pelvic or hypogastric nerve stimulation. omega-Conotoxin GVIA (CTX GVIA, 100 nM) or the novel N-type calcium channel antagonist, CTX CVID (100 nM) reduced the amplitude of EPSPs evoked after pelvic nerve stimulation by 50-75% but had no effect on EPSPs evoked by hypogastric nerve stimulation. Combined addition of CTX GVIA and CTX CVID was no more effective than either antagonist alone. EPSPs evoked by stimulating either nerve trunk were not inhibited by the P/Q calcium channel antagonist, omega-agatoxin IVA (100 nM), nor the L-type calcium channel antagonist, nifedipine (30 muM). SNX 482 (300 nM), an antagonist at some R-type calcium channels, inhibited EPSPs after hypogastric nerve stimulation by 20% but had little effect on EPSPs after pelvic nerve stimulation. Amiloride (100 muM) inhibited EPSPs after stimulation of either trunk by 40%, while nickel (100 muM) was ineffective. CTX GVIA or CTX CVID (100 nM) also slowed the rate of action potential repolarization and reduced afterhyperpolarization amplitude in paracervical neurons. Thus, release of transmitter from the terminals of sacral preganglionic neurons is largely dependent on calcium influx through N-type calcium channels, although an unknown calcium channel which is resistant to selective antagonists also contributes to release. Release of transmitter from lumbar preganglionic neurons does not require calcium entry through either conventional N-type calcium channels or the variant CTX CVID-sensitive N-type calcium channel and seems to be mediated largely by a novel calcium channel. (C) 2004 IBRO. Published by Elsevier Ltd. All rights reserved.

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Background: Clinicians frequently use lithium to augment antipsychotic medication in schizophrenia. Therefore, we undertook a systematic review and meta-analysis of the use of lithium in the treatment of schizophrenia. Data sources and study selection: Randomized controlled trials examining lithium (as a sole or an adjunctive compound) in participants with schizophrenia or related disorders were searched in the register of the Cochrane Schizophrenia Group. No language restrictions were applied. The Boolean phrase [lithium* or lithicarb or eskalith or lithobid or lithane or cibalith-s or quilonum or hypnorex] was used to locate articles. The search strategy initially identified 90 references. The authors of the included studies were contacted to obtain original patient data. The data were combined in a meta-analysis. The main outcome parameters were the number of patients with a clinically significant response and the number of patients leaving the studies early. Results: The meta-analysis includes 20 studies (N = 611). The evidence shows that lithium as a sole agent is ineffective in the treatment of schizophrenia. Eleven trials examined the augmentation of antipsychotics with lithium. More patients who received lithium augmentation than those who received antipsychotics alone were classified as responders. However, the superiority was not consistent across different response thresholds, and when patients with prominent affective symptoms were excluded from the analysis, the advantage of lithium augmentation was not significant (p = .07). Significantly more patients taking lithium left the trials early, suggesting a lower acceptability of lithium augmentation compared with that of taking antipsychotics alone. Conclusion: Despite some evidence in favor of lithium augmentation, the overall results are inconclusive. A large trial of lithium augmentation of antipsychotic medications will be required in order to detect a benefit of small effect size in patients with schizophrenia who lack affective symptoms.

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To determine the effects of nitrogen source on rates of net N transfer between plants connected by a common mycorrhizal network, we measured transfer of N supplied as (NH4NO3)-N-15-N-14 or (NH4NO3)-N-14-N-15 in three Casuarina/Eucalyptus treatments interconnected by a Pisolithus sp. The treatments were nonnodulated nonmycorrhizal/nonmycorrhizal; nonnodulated mycorrhizal/mycorrhizal; and nodulated mycorrhizal/mycorrhizal. Mycorrhization was 67% in Eucalyptus and 36% in Casuarina. N-2 fixation supplied 38% of the N in Casuarina. Biomass, N and N-15 contents were lowest in nonmycorrhizal plants and greatest in plants in the nodulated/mycorrhizal treatment. Nitrogen transfer was enhanced by mycorrhization and by nodulation, and was greater when N was supplied as (NH4+)-N-15 than (NO3-)-N-15. Nitrogen transfer rates were lowest in the nonmycorrhizal treatment for either N-15 source, and greatest in the nodulated, mycorrhizal treatment. Transfer was greater to Casuarina than to Eucalyptus and where ammonium rather than nitrate was the N source. Irrespective of N-15 source and of whether Casuarina or Eucalyptus was the N sink, net N transfer was low and was similar in both nonnodulated treatments. However, when Casuarina was the N sink in the nodulated, mycorrhizal treatment, net N transfer was much greater with (NH4+)-N-15 than with (NO3-)-N-15. High N demand by Casuarina resulted in greater net N transfer from the less N-demanding Eucalyptus. Net transfer of N from a non-N-2-fixing to an N-2-fixing plant may reflect the very high N demand of N-2-fixing species.

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Study objective: UK government policy mandates the introduction of 'intermediate care services' to reduce emergency admissions to hospital from the population aged 75 years or more. We evaluated one of these initiatives-the Keep Well At Home (KWAH) Project-in a West London Primary Care Trust. Design: KWAH involves a two-phase screening process, including a home visit by a community nurse. We employed cohort methods to determine whether KWAH resulted in fewer emergency attendances and admissions to hospital in the target population, from October 1999 to December 2002. Results: estimated levels of coverage in the two phases of screening were 61 and 32%, respectively. The project had not maintained records of which additional health and social care services had been delivered following screening. The rates of emergency admissions to hospital in the 9 months before screening were similar in practices that did and did not join the project (rate ratio (RR) = 1.05; 95% CI 0.95-1.17), suggesting absence of volunteer bias. Over the first 37 months of the project, there was no significant impact on either attendances at Accident & Emergency departments (RR = 1.02; 95% CI 0.97-1.06) or emergency admissions of elderly patients (RR = 0.98; 95% CI 0.93-1.05). Conclusion: the KWAH Project has been ineffective in reducing emergency admissions among the elderly. Significant questions arise in relation to selection of the screening instruments, practicality of achieving higher coverage of the eligible population, and creation of a new postcode lottery.

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Treatment of cut freesia var. Cote d'Azur flowers with methyl jasmonate (MeJA, 0.1 mu l MeJA l(-1)) vapour suppressed petal specking caused by Botrytis cinerea infection. MeJA efficacy was concentration and incubation temperature dependent. Disease severity, lesion numbers and lesion diameters decreased with increasing MeJA concentration from 0.025 to 0.1 mu l MeJA l(-1). However, there were no significant (P > 0.05) differences among MeJA concentrations examined. MeJA was more effective in reducing B. cinerea flower specking at 20 degrees C than at 12 degrees C. MeJA treatment was ineffective at 5 degrees C. At 20 degrees C, MeJA treatment at 0.1 mu l MeJA l(-1) reduced disease severity, lesion numbers and lesion diameters by 58, 50 and 48%, respectively, as compared to untreated controls. In a repeat experiment, disease severity, lesion numbers and lesion diameters on MeJA vapour treated flowers after 12 h of incubation were reduced by 68, 56 and 50%, respectively. MeJA did not exert direct antifungal activity in-vitro, suggesting that treatment in-vivo reduced B. cinerea-induced flower specking by induction of host defence responses. MeJA at 0.1 mu l MeJA l(-1) significantly (P < 0.05) increased vase life of cut freesia flowers and delayed senescence judged by lower wilt scores and higher fresh weights as compared to untreated controls. (c) 2005 Elsevier B.V. All rights reserved.

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Including positive end-expiratory pressure (PEEP) in the manual resuscitation bag (MRB) may render manual hyperinflation (MHI) ineffective as a secretion maneuver technique in mechanically ventilated patients. In this study we aimed to determine the effect of increased PEEP or decreased compliance on peak expiratory flow rate (PEF) during MHI. A blinded, randomized study was performed on a lung simulator by 10 physiotherapists experienced in MHI and intensive care practice. PEEP levels of 0-15 cm H2O, compliance levels of 0.05 and 0.02 L/cm H2O, and MRB type were randomized. The Mapleson-C MRB generated significantly higher PEF (P < 0.01, d = 2.72) when compared with the Laerdal MRB for all levels of PEEP. In normal compliance (0.05 L/cm H2O) there was a significant decrease in PEF (P < 0.01, d = 1.45) for a PEEP more than 10 cm H2O in the Mapleson-C circuit. The Laerdal MRB at PEEP levels of more than 10 cm H2O did not generate a PEF that is theoretically capable of producing two-phase gas-liquid flow and, consequently, mobilizing pulmonary secretions. If MHI is indicated as a result of mucous plugging, the Mapleson-C MRB may be the most effective method of secretion mobilization.

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1. Management decisions regarding invasive plants often have to be made quickly and in the face of fragmentary knowledge of their population dynamics. However, recommendations are commonly made on the basis of only a restricted set of parameters. Without addressing uncertainty and variability in model parameters we risk ineffective management, resulting in wasted resources and an escalating problem if early chances to control spread are missed. 2. Using available data for Pinus nigra in ungrazed and grazed grassland and shrubland in New Zealand, we parameterized a stage-structured spread model to calculate invasion wave speed, population growth rate and their sensitivities and elasticities to population parameters. Uncertainty distributions of parameters were used with the model to generate confidence intervals (CI) about the model predictions. 3. Ungrazed grassland environments were most vulnerable to invasion and the highest elasticities and sensitivities of invasion speed were to long-distance dispersal parameters. However, there was overlap between the elasticity and sensitivity CI on juvenile survival, seedling establishment and long-distance dispersal parameters, indicating overlap in their effects on invasion speed. 4. While elasticity of invasion speed to long-distance dispersal was highest in shrubland environments, there was overlap with the CI of elasticity to juvenile survival. In shrubland invasion speed was most sensitive to the probability of establishment, especially when establishment was low. In the grazed environment elasticity and sensitivity of invasion speed to the severity of grazing were consistently highest. Management recommendations based on elasticities and sensitivities depend on the vulnerability of the habitat. 5. Synthesis and applications. Despite considerable uncertainty in demography and dispersal, robust management recommendations emerged from the model. Proportional or absolute reductions in long-distance dispersal, juvenile survival and seedling establishment parameters have the potential to reduce wave speed substantially. Plantations of wind-dispersed invasive conifers should not be sited on exposed sites vulnerable to long-distance dispersal events, and trees in these sites should be removed. Invasion speed can also be reduced by removing seedlings, establishing competitive shrubs and grazing. Incorporating uncertainty into the modelling process increases our confidence in the wide applicability of the management strategies recommended here.

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Neutrophilic lung inflammation is an essential component of host defense against diverse eukaryotic and prokaryotic pathogens, but in chronic inflammatory lung diseases, such as chronic obstructive lung disease (COPD), severe asthma, cystic fibrosis, and bronchiolitis, it may damage the host. Glucocorticosteroids are widely used in these conditions and in their infectious exacerbations; however, the clinical efficacy of steroids is disputed. In this study, we used a proteomic approach to identify molecules contributing to neutrophilic inflammation induced by transnasal administration of lipopolysaccharide (LPS) that were also resistant to the potent glucocorticosteroid dexamethasone (Dex). We confirmed that Dex was biologically active at both the transcript (suppression of GM-CSF and TNFalpha transcripts) and protein levels (induction of lipocortin) and used 2D-PAGE/MALDI-TOF to generate global expression profiles, identifying six LPS-induced proteins that were Dex resistant. Of these, S100A8, a candidate neutrophil chemotactic factor, was profiled in detail. Steroid refractory S100A8 expression was highly abundant, transcriptionally regulated, secreted into lung lavage fluid and immunohistochemically localized to tissue infiltrating neutrophils. However, in marked contrast to other vascular beds, neutralizing antibodies to S100A8 had only a weak anti-neutrophil recruitment effect and antibodies against the related S100A9 were ineffective. These data highlight the need for extensive in vivo profiling of proteomically identified candidate molecules and demonstrates that S100A8, despite its abundance, resistance to steroids and known chemotactic activity, is unlikely to be an important determinant of LPS-induced neutrophilic lung inflammation in vivo.

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Background More than 50% of patients with Crohn's disease become either steroid resistant or dependent. Accordingly, development of new treatments for steroid-dependent Crohn's disease is a research priority. Aim To evaluate CDP571, a humanized antibody to tumour necrosis factor-α, for the treatment of steroid-dependent Crohn's disease. Methods Patients with steroid-dependent Crohn's disease (n = 271) were enrolled in a 36-week, double-blind, placebo-controlled trial. Steroid dependence was defined as use of prednisolone or prednisone (15–40 mg/day) or budesonide (9 mg/day) for ≥8 weeks, a previous failed attempt to decrease or discontinue steroids within 8 weeks of screening, and a Crohn's Disease Activity Index score of ≤150 points. Patients were randomized to receive intravenous CDP571 10 mg/kg or placebo 8-weekly through to week 32. Steroids were then tapered using a defined schedule. The primary efficacy endpoint was the percentage of patients with steroid sparing, defined as discontinuation of steroid therapy without a disease flare (Crohn's Disease Activity Index score ≥220 points) at week 36. Results Steroid sparing occurred in 53 of 181 (29.3%) CDP571 patients and 33 of 90 (36.7%) placebo patients (P = 0.24). Adverse events occurred at similar frequencies in both treatment groups. Conclusions CDP571 was ineffective for sparing steroids in patients with steroid-dependent Crohn's disease. CDP571 was well tolerated.

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Reforestation in tropical areas is usually attempted by planting seedlings but, direct seeding (the artificial addition or sowing of seed) may be an alternative way of accelerating forest recovery and successional processes. This study investigated the effects of various sowing treatments (designed to create different microsite conditions for seed germination) and seed sizes on the early establishment and growth of directly sown rainforest tree species in a variety of experimental plots at three sites in the wet tropical region of north-cast Queensland, Australia. The different sowing treatments were found to have significant effects on seedling establishment. Broadcast sowing treatments were ineffective and resulted in very poor seedling establishment and high seed wastage. Higher establishment rates occurred when seeds were buried. Seed size was found to be an important factor affecting establishment in relation to micro-site condition. In general, larger seeded species had higher establishment rates at all three sites than species of small and intermediate seed size, but only in sowing treatments where seeds were buried. Overall these results suggest that direct sowing of seed can be used as a too] to accelerate recolonisation of certain rainforest tree species on degraded tropical lands, but initial success will be dependent on the choice of sowing method and its suitability for the seed types selected. The results also indicate that the recruitment of naturally dispersed tree species at degraded sites is likely to be severely limited by the availability of suitable microsites for seed germination. Consequently the natural recovery of degraded sites via seed rain can be expected to be slow and unpredictable, particularly in areas where soil compaction has occurred. (c) 2006 Elsevier B.V. All rights reserved.

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The failures of traditional target-species management have led many to propose an ecosystem approach to fisheries to promote sustainability. The ecosystem approach is necessary, especially to account for fishery-ecosystem interactions, but by itself is not sufficient to address two important factors contributing to unsustainable fisheries: inappropriate incentives bearing on fishers and the ineffective governance that frequently exists in commercial, developed fisheries managed primarily by total-harvest limits and input controls. We contend that much greater emphasis must be placed on fisher motivation when managing fisheries. Using evidence from more than a dozen natural experiments in commercial fisheries, we argue that incentive-based approaches that better specify community and individual harvest or territorial rights and price ecosystem services and that are coupled with public research, monitoring, and effective oversight promote sustainable fisheries.

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Experiments to design physical activity programs that optimize their osteogenic potential are difficult to accomplish in humans. The aim of this article is to review the contributions that animal studies have made to knowledge of the loading conditions that are osteogenic to the skeleton during growth, as well as to consider to what extent animal studies fail to provide valid models of physical activity and skeletal maturation. Controlled loading studies demonstrate that static loads are ineffective, and that bone formation is threshold driven and dependent on strain rate, amplitude, and duration of loading. Only a few loading cycles per session are required, and distributed bouts are more osteogenic than sessions of long duration. Finally, animal models fail to inform us of the most appropriate ways to account for the variations in biological maturation that occur in our studies of children and adolescents, requiring the use of techniques for studying human growth and development.

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Since 2002, the usually uncommon endemic filamentous brown alga Hincksia sordida (Harvey) Silva (Ectocarpales, Phaeophyta) has formed nuisance blooms annually during spring/early summer at Main Beach, Noosa on the subtropical east Australian coast. The Hincksia bloom coincides with the normally intensive recreational use of the popular bathing beach by the local population and tourists. The alga forms dense accumulations in the surf zone at Main Beach, giving the seawater a distinct brown coloration and deterring swimmers from entering the water. Decomposing algae stranded by receding tides emit a nauseating sulphurous stench which hangs over the beach. The stranded algal biomass is removed from the beach by bulldozers. During blooms, the usually crowded Main Beach is deserted, bathers preferring to use the many unaffected beaches on the Sunshine Coast to the south of Main Beach. The bloom worsens with north-easterly winds and is cleared from Noosa by south easterly winds, observations which have prompted the untenable proposal by local authorities that the bloom is forming offshore of Fraser Island in the South Pacific Ocean. The Noosa River estuarine system/Laguna Bay is the more probable source of the bloom and the nutrient inputs into this system must be substantial to generate the high bloom biomass. Current mitigation procedures of removing the blooming alga off the beach with bulldozers treat the symptom, not the cause and are proving ineffective. Environmental management must be based on science and the Noosa bloom would benefit greatly from the accurate ecological data on which to base management options. (c) 2006 Elsevier Ltd. All rights reserved.

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Eczema is common, occurring in 15%-20% of infants and young children. For some infants it can be a severe chronic illness with a major impact on the child's general health and on the family. A minority of children will continue to have eczema as adults. The exact cause of eczema is not clear, but precipitating or aggravating factors may include food allergens (most commonly, egg) or environmental allergens/irritants, climatic conditions, stress. and genetic predisposition. Management of eczema consists of education; avoidance of triggers and allergens; liberal use of emollients or topical steroids to control inflammation; use of antihistamines to reduce itch; and treatment of infection if present. Treatment with systemic agents may be required in severe cases, but must be supervised by an immunologist. Urticaria (hives) may affect up to a quarter of people at some time in their lives. Acute urticaria is more common in children, while chronic urticaria is more common in adults. Chronic urticaria is not life-threatening, but the associated pruritus and unsightly weals can cause patients much distress and significantly affect their daily lives. Angioedema coexists with urticaria in about 50% of patients. It typically affects the lips, eyelids, palms, soles and genitalia. Management of urticaria is through education; avoidance of triggers and allergens (where relevant); use of antihistamines to reduce itch; and short-term use of corticosteroids when antihistamine therapy is ineffective. Referral is indicated for patients with resistant disease.

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Legume plants carefully control the extent of nodulation in response to rhizobial infection. To examine the mechanism underlying this process we conducted a detailed analysis of the Lotus japonicus hypernodulating mutants, har1-1, 2 and 3 that define a new locus, HYPERNODULATION ABERRANT ROOT FORMATION (Har1), involved in root and symbiotic development. Mutations in the Har1 locus alter root architecture by inhibiting root elongation, diminishing root diameter and stimulating lateral root initiation. At the cellular level these developmental alterations are associated with changes in the position and duration of root cell growth and result in a premature differentiation of har1-1 mutant root. No significant differences between har1-1 mutant and wild-type plants were detected with respect to root growth responses to 1-aminocyclopropane1-carboxylic acid, the immediate precursor of ethylene, and auxin; however, cytokinin in the presence of AVG (aminoetoxyvinylglycine) was found to stimulate root elongation of the har1-1 mutant but not the wild-type. After inoculation with Mesorhizobium loti, the har1 mutant lines display an unusual hypernodulation (HNR) response, characterized by unrestricted nodulation (hypernodulation), and a concomitant drastic inhibition of root and shoot growth. These observations implicate a role for the Har1 locus in both symbiotic and non-symbiotic development of L. japonicus, and suggest that regulatory processes controlling nodule organogenesis and nodule number are integrated in an overall mechanism governing root growth and development.