851 resultados para Persistent efficacy


Relevância:

100.00% 100.00%

Publicador:

Resumo:

The present study aimed to evaluate the persistent efficacy of a 3.5% doramectin* (700μg/kg) formulation compared to 3.15% ivermectin** (630μg/kg) treatment, administered subcutaneously at a dose of 1mL/50kg body weight in cattle experimentally infected with gastrointestinal nematodes. Seventy-two male crossbred Holstein cattle that were negative for helminth infection were divided into nine groups. Treatments of 3.5% doramectin (Groups 2, 4, 6 and 8) and 3.15% ivermectin (Groups 3, 5, 7 and 9) were administered on days 49, 42, 35 and 28 prior to challenge with infectious nematode larvae (L3). Animals in the control group (Group 1) received saline solution on day 49 before challenge. Beginning on day zero, each animal received 50mL orally of a mixed culture containing approximately 3,000 third stage larvae (L3) of Haemonchus (60%), Oesophagostomum (20%), Cooperia (15%) and Trichostrongylus (5%) for seven consecutive days, resulting in a total challenge of 21,000 larvae/animal. Due to the large number of cattle, autopsies were performed between days 28 and 35 after the last day of inoculation. The formulation containing doramectin (700 mcg/kg) achieved persistent efficacy against H. placei and C. punctata for 49 and 35days, respectively. The persistent efficacy of ivermectin (630 mcg/kg) against H. placei lasted for 49days, but this treatment was ineffective against C. punctata. Both formulations demonstrated persistent efficacy against T. axei for 49days. The persistent efficacy of doramectin (700 mcg/kg) and ivermectin (630 mcg/kg) lasted for 49 and 42days against O. radiatum, respectively. © 2012 Elsevier Ltd.

Relevância:

70.00% 70.00%

Publicador:

Resumo:

As a result of the need to develop new active principles for the control of endoparasites in ruminants, the present in vivo study evaluated a formulation containing 24% Aurixazol (48 mg/kg), a parasiticide molecule based on disophenolate of levamisole. Two experiments were conducted: one evaluating the anthelmintic efficacy of 24% Aurixazol (48 mg/kg) against gastrointestinal nematodes in naturally infected sheep, compared to an association of ivermectin (0.2 mg/kg) + albendazole (5.0 mg/kg) + levamisole (7.5 mg/kg) (IAL), and a second one which evaluated the persistent efficacy of the same formulation against immature stages (L4) and adults of Haemonchus contortus in experimentally infected animals. In experiment I, against H. contortus, the formulation of Aurixazol and the IAL association reached efficacies (arithmetic means) of 99.32% and 96.11%, respectively. For Trichostrongylus colubriformis, the efficacy values were 88.92% and 98.08% for Aurixazol and the IAL association, respectively. Both formulations were totally effective against Oesophagostomum columbianum (100%). The results of the statistical analysis demonstrated that the mean parasitic burden of treated animals was significantly different (P ≤ 0.05) compared to the average number of helminths diagnosed in animals from the control group for H. contortus, T. colubriformis and O. columbianum. Comparing only the treated groups, it was possible to verify that the average number of H. contortus recovered from animals treated with Aurixazol was different (P ≤ 0.05) when compared to the mean amount recovered from sheep treated with the IAL association. When evaluating the prevention of H. contortus infection in experiment II, Aurixazol did not present preventive efficacy. Up until 21 days after treatment the groups treated with Aurixazol contained less adults and L4 of H. contortus (P ≤ 0.05) when compared to the non-medicated control group. However, future studies will be necessary to assess the effectiveness of Aurixazol against nematode strains resistant to levamisole and disophenol, but the efficacy results described in this study allow to state that Aurixazol can, associated with other measures, become an important tool in the control of sheep nematodes. © 2013.

Relevância:

70.00% 70.00%

Publicador:

Resumo:

These guidelines have been prepared to assist in the planning, conduct and interpretation of studies for the assessment of the efficacy of acaricides (excluding vaccines and other bio-control agents) against single and multi-host ticks (Ixodidae) on ruminants. Information is provided on the selection of animals, dose determination, dose confirmation and field studies, record keeping and result interpretation. The use of pen facilities is advocated for dose determination and confirmation studies for defining therapeutic and persistent efficacy. A minimum of two studies per tick species for which claims are sought is recommended for each dose determination and dose confirmation investigation. If dose confirmation studies demonstrate greater than 95% efficacy the sponsor may proceed to field studies, where a minimum of two studies per geographical location is preferred to confirm the therapeutic and persistent efficacy under field conditions. If dose confirmation studies demonstrate less than 95% efficacy then longer-term field studies can be conducted over two tick seasons with a minimum of two studies per geographical location. These studies can incorporate other control methods such as tick vaccines, to demonstrate stable long-term tick management. Specific advice is also given on conducting studies with paralysis ticks. These guidelines are also intended to assist investigators on how to conduct specific experiments, to provide specific information for registration authorities involved in the decision-making process, to assist in the approval and registration of new acaricides, and to facilitate the worldwide adoption of standard procedures. (c) 2005 Elsevier B.V. All rights reserved.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Persistent pain is a commonly experienced symptom. It affects 25% of community-dwelling older adults and up to 80% of nursing home residents, and can have a major impact on quality of life and functional capacity. Unfortunately pain in older patients is often undertreated and misunderstood. Assessment of pain type and severity is important. Most older people, even with moderately impaired cognition, are able to self-report pain. Validated assessment tools using non-verbal pain cues are available for people with more advanced cognitive impairment. Management of pain in older people can be challenging. Physiological changes may impact on pain perception and the pharmacodynamics and pharmacokinetics of medications. Older people are often more sensitive to the adverse effects of analgesic medications and are at risk of drug–drug interactions due to the presence of co-morbidities and polypharmacy. In general, analgesic medications should be commenced at low doses, titrated based on effect and tolerability, and regularly reviewed. Contemporary pain management often utilises multiple analgesics in lower doses to optimise efficacy and avoid dose-related toxicity. A bio-psycho-social approach to the management of persistent pain, utilising a multidisciplinary team and including non-drug strategies, may produce the best results. The goal of pain management is not always to eliminate pain, since this may not be attainable, but rather to enhance function and improve quality of life. This article discusses persistent non-cancer pain in older people, its assessment and management, and the risks and benefits of pharmacological treatment in this population.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Experience-dependent long-lasting increases in excitatory synaptic transmission in the hippocampus are believed to underlie certain types of memory(1-3). Whereas stimulation of hippocampal pathways in freely moving rats can readily elicit a long-term potentiation (LTP) of transmission that may last for weeks, previous studies have failed to detect persistent increases in synaptic efficacy after hippocampus-mediated learning(4-6). As changes in synaptic efficacy are contingent on the history of plasticity at the synapses(7), we have examined the effect of experience-dependent hippocampal activation on transmission after the induction of LTP, We show that exploration of a new, non-stressful environment rapidly induces a complete and persistent reversal of the expression of high-frequency stimulation-induced early-phase LTP in the CA1 area of the hippocampus, without affecting baseline transmission in a control pathway. LTP expression is not affected by exploration of familiar environments. We found that spatial exploration affected LTP within a defined time window because neither the induction of LTP nor the maintenance of long-established LTP was blocked. The discovery of a novelty-induced reversal of LTP expression provides strong evidence that extensive long-lasting decreases in synaptic efficacy may act in tandem with enhancements at selected synapses to allow the detection and storage of new information by the hippocampus.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Respiratory syncytial virus (RSV) is an important cause of severe upper and lower respiratory disease in infants and in the elderly. There are 2 main RSV subtypes A and B. A recombinant vaccine was designed based on the central domain of the RSV-A attachment G protein which we had previously named G2Na (aa130–230). Here we evaluated immunogenicity, persistence of antibody (Ab) response and protective efficacy induced in rodents by: (i) G2Na fused to DT (Diphtheria toxin) fragments in cotton rats. DT fusion did not potentiate neutralizing Ab responses against RSV-A or cross-reactivity to RSV-B. (ii) G2Nb (aa130–230 of the RSV-B G protein) either fused to, or admixed with G2Na. G2Nb did not induce RSV-B-reactive Ab responses. (iii) G2Na at low doses. Two injections of 3 µg G2Na in Alum were sufficient to induce protective immune responses in mouse lungs, preventing RSV-A and greatly reducing RSV-B infections. In cotton rats, G2Na-induced RSV-reactive Ab and protective immunity against RSV-A challenge that persisted for at least 24 weeks. (iv) injecting RSV primed mice with a single dose of G2Na/Alum or G2Na/PLGA [poly(D,L-lactide-co-glycolide]. Despite the presence of pre-existing RSV-specific Abs, these formulations effectively boosted anti-RSV Ab titres and increased Ab titres persisted for at least 21 weeks. Affinity maturation of these Abs increased from day 28 to day 148. These data indicate that G2Na has potential as a component of an RSV vaccine formulation.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Neem leaves, neem cake (a by-product left after the extraction of oil from neem seed) and a commercially refined product aza (azadirachtin) extracted from seed were evaluated. Aqueous extracts of crude neem formulations used as a seedling dip treatment significantly reduced the number of females and egg masses in roots whereas the refined one did not. A split-root technique was used to demonstrate the translocation of active compounds within a plant and their subsequent effect on the development of nematodes. When applied to the root portion all formulations significantly reduced the number of egg masses and eggs per egg mass. Whereas on the untreated root portion, neem cake at 3% w/w and aza at 0.1% w/w significantly reduced the number of egg masses as compared with neem leaves at 3% w/w, aza at 0.05% and control. All the neern formulations significantly reduced the number of eggs per egg mass on' the untreated root portion. The effect of neem leaves and cake on the development of root-knot nematodes was tested at 2, 4, 6, 8, and 16 weeks after their application to soil. Even after 16 weeks all the treatments significantly reduced the galling index and number of egg masses but their effectiveness declined over time. After storing neem leaves, cake and aza for 8 months under ambient conditions the efficacy of neem leaves and aza, against root-knot nematodes, remained stable whereas that of cake declined. (c) 2006 Elsevier Ltd. All rights reserved.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Background and purpose: The aim of this report is to study mechanisms of G protein activation by agonists. Experimental approach: The association and dissociation of guanosine 5'-O-(3-[S-35] thio) triphosphate ([S-35] GTP gamma S) binding at G proteins in membranes of CHO cells stably transfected with the human dopamine D-2short receptor was studied in the presence of a range of agonists. Key results: Binding of [S-35] GTPgS was dissociable in the absence of agonist and dissociation was accelerated both in rate and extent by dopamine, an effect which was blocked by the dopamine D-2 receptor antagonist raclopride and by suramin, which inhibits receptor/G protein interaction. A range of agonists of varying efficacy increased the rate of dissociation of [S-35] GTPgS binding, with the more efficacious agonists resulting in faster dissociation. Agonists were able to dissociate about 70% of the pre-bound [S-35] GTPgS, leaving a component which may not be accessible to the agonist-bound receptor. The dissociable component of the [S-35] GTPgS binding was reduced with longer association times and increased [S-35] GTPgS concentrations. Conclusions and implications: These data are consistent with [S-35] GTPgS binding being initially to receptor-linked G proteins and then to G proteins which have separated from the agonist bound receptor. Under the conditions used typically for [S-35] GTPgS binding assays, therefore, much of the agonist-receptor complex remains in proximity to G proteins after they have been activated by agonist.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Objective: This study aimed to evaluate prospectively the influence and the evolution of periodontal disease (PD) in rheumatoid arthritis (RA) patients submitted to anti-tumor necrosis factor (TNF) therapy. Methods: Eighteen patients with RA (according to the American College of Rheumatology criteria) were assessed for PD before (BL) and after 6 months (6M) of anti-TNF treatment: 15 infliximab, 2 adalimumab, and 1 etanercept. Periodontal assessment included plaque and gingival bleeding indices, probing pocket depth, cementoenamel junction, and clinical attachment level. Rheumatologic evaluation was performed blinded to the dentist's assessment: demographic data, clinical manifestations, and disease activity (Disease Activity Score using 28 joints [DAS28], erythrocyte sedimentation rate [ESR], and C-reactive protein [CRP]). Results: The median age and disease duration of patients with RA were 50 years (25-71 y) and 94% were female. Periodontal disease was diagnosed in 8 patients (44.4%). Comparing BL to 6M, periodontal parameters in the entire group remained stable (P > 0.05) throughout the study (plaque and gingival bleeding indices, probing pocket depth, cementoenamel junction, and clinical attachment level), whereas an improvement in most analyzed RA parameters was observed in the same period: DAS28 (5.5 vs. 3.9, P = 0.02), ESR (21 vs. 12.5 mm/first hour, P = 0.07), and CRP (7.8 vs. 2.8 mg/dL, P = 0.25). Further analysis revealed that this improvement was restricted to the group of patients without PD (DAS28 [5.5 vs. 3.6, P = 0.04], ESR [23.0 vs. 11.5 mm/first hour, P = 0.008], and CRP [7.4 vs. 2.1, P = 0.01]). In contrast, patients with PD had lack of response, with no significant differences in disease activity parameters between BL and 6M: DAS28 (5.2 vs. 4.4, P = 0.11), ESR (17.0 vs. 21.0, P = 0.56), and CRP (9.0 vs. 8.8, P = 0.55). Conclusions: This study supports the notion that PD may affect TNF blocker efficacy in patients with RA. The possibility that a sustained gingival inflammatory state may hamper treatment response in this disease has high clinical interest because this is a treatable condition.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Over the past years, evidence for the efficacy of psychological therapies in schizophrenia has been summarized in a series of meta-analyses. The present contribution aims to provide a descriptive survey of the evidence for the efficacy of psychological therapies as derived from these meta-analyses and to supplement them by selected findings from an own recent meta-analysis. Relevant meta-analyses and randomized controlled trials were identified by searching several electronic databases and by hand searching of reference lists. In order to compare the findings of the existing meta-analyses, the reported effect sizes were extracted and transformed into a uniform effect size measure where possible. For the own meta-analysis, weighted mean effect size differences between comparison groups regarding various types of outcomes were estimated. Their significance was tested by confidence intervals, and heterogeneity tests were applied to examine the consistency of the effects. From the available meta-analyses, social skills training, cognitive remediation, psychoeducational coping-oriented interventions with families and relatives, as well as cognitive behavioral therapy of persistent positive symptoms emerge as effective adjuncts to pharmacotherapy. Social skills training consistently effectuates the acquisition of social skills, cognitive remediation leads to short-term improvements in cognitive functioning, family interventions decrease relapse and hospitalization rates, and cognitive behavioral therapy results in a reduction of positive symptoms. These benefits seem to be accompanied by slight improvements in social functioning. However, open questions remain as to the specific therapeutic ingredients, to the synergistic effects, to the indication, as well as to the generalizability of the findings to routine care.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

BACKGROUND: Patients who require extracorporeal membrane oxygenation (ECMO) postsurgery for congenital heart disease (CHD) frequently experience severe bleeding episodes. Whereas recombinant-activated factor VII (rFVIIa) has proven efficacy in counteracting intractable hemorrhage in various scenarios, its use in patients on ECMO is limited by the increased risk for thrombotic events. METHODS: Between December 2004 and January 2006, ECMO was used in 10 pediatric patients following cardiac surgery, of whom seven were treated with rFVIIa because of intractable hemorrhage. Their medical records were reviewed with respect to variations in chest tube output and transfusion requirements, occlusion of or thrombus formation in the ECMO circuit and the occurrence of thromboembolic events. Outcome and rate of ECMO circuit occlusion were compared with historic controls. RESULTS: Three patients died, and four survived (none of the deaths was attributable to thrombus formation or bleeding). All patients were treated with aprotinin prior to and during rFVIIa therapy. Two patients developed an occlusion of the oxygenator, one after receiving co-medication with a FXIII concentrate, another after RBC transfusion in the ECMO system. In two patients, thrombus formation was observed in the ECMO system on inspection after discontinuation. Thromboembolic events were not observed. CONCLUSIONS: Recombinant-activated factor VII in a median dosage of 90 microg.kg(-1) was used in seven pediatric patients on ECMO. Rates of ECMO system occlusions and mortality did not differ from historic controls. Neither the reduction of chest tube output nor the blood product transfusion requirements did reach statistical significance.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Background: Dyspnea is a common and distressing symptom among patients with advanced cancer. The role of bilevel positive airway pressure (BIPAP) and Vapotherm in the relief of dyspnea have not been well defined. We aimed to determine and to compare the efficacy of BIPAP and VapoTherm for cancer related dyspnea. Methods: In this randomized, open-label, crossover study, we randomly assigned advanced cancer patients with persistent dyspnea >=3/10 to either Vapotherm for 2 hours followed by BiPAP for 2 hours, or BiPAP followed by Vaptherm. A variable washout period was instituted between interventions. The primary end point was change in numeric rating scale before and after each intervention. We planned to enroll 50 patients in total. Results: Among the 803 patients screened over the last 8 months, 62 (26%) were eligible, and 16 (2%) were enrolled so far. Five patients completed the entire study successfully, 4 discontinued the study prematurely due to prolonged relief of dyspnea, and 7 dropped out for various reasons, including inability to tolerate BiPAP (N=3), anxiety (N=2), fatigue (N=1) and pain requiring opioids (N=1). The median baseline numeric rating score for dyspnea was 7/10 (interquartile range (IQR) 5-8), and the median baseline Borg score was 4/10 (3-7). Interim analysis revealed that BiPAP was associated with a median change in numeric rating score of -3 (N=10, IQR -6.3 to -1, p=0.007) and modified Borg score of -1 (N=10, IQR -3 to 0.3, p=0.058), while Vapotherm was associated with a median change in numeric rating score of -2 (N=9, IQR -3 to -1, p=0.011) and modified Borg score of -2.5 (N=8, IQR -5.5 to -0.1, p=0.051). Among the 5 individuals who completed the entire study, 2 preferred Vapotherm, 2 favored BiPAP, and 1 liked both. The respiratory rate decreased and the oxygen saturation improved with both interventions. No significant toxicities were observed. Conclusions: We were successfully able to enroll patients onto this clinic trial. Our preliminary results suggest that BiPAP and Vapotherm are highly efficacious in providing relief for patients with persistent refractory dyspnea. A direct comparison of the two interventions will be done upon study completion. Further research is necessary to confirm our findings.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

BACKGROUND -This study aimed to determine five-year efficacy of catheter ablation for persistent atrial fibrillation (PsAF) using AF termination as a procedural endpoint. METHODS AND RESULTS -150 patients (57±10 years) underwent PsAF ablation using a stepwise ablation approach (pulmonary vein isolation, electrogram-guided and linear ablation) with the desired procedural endpoint being AF termination. Repeat ablation was performed for recurrent AF or atrial tachycardia (AT). AF was terminated by ablation in 120 patients (80%). Arrhythmia-free survival rates after a single procedure were 35.3±3.9%, 28.0±3.7%, and 16.8±3.2% at 1, 2, and 5 years, respectively. Arrhythmia-free survival rates after the last procedure (mean 2.1±1.0 procedures) were 89.7±2.5%, 79.8±3.4%, and 62.9±4.5%, at 1, 2, and 5 years, respectively. During a median follow-up of 58 (IQR 43-73) months following the last ablation procedure, 97 of 150 (64.7%) patients remained in sinus rhythm without antiarrhythmic drugs (AADs). Another 14 (9.3%) patients maintained sinus rhythm after re-initiation of AADs, and an additional 15 (10.0%) patients regressed to paroxysmal recurrences only. Failure to terminate AF during the index procedure (HR 3.831; 95%CI: 2.070-7.143; p<0.001), left atrial diameter ≥50mm (HR 2.083; 95%CI: 1.078-4.016; p=0.03), continuous AF duration ≥18 months (HR 1.984; 95%CI: 1.024-3.846; p<0.04) and structural heart disease (HR 1.874; 95% CI: 1.037-3.388; p=0.04) predicted arrhythmia recurrence. CONCLUSIONS -In patients with PsAF, an ablation strategy aiming at AF termination is associated with freedom from arrhythmia recurrence in the majority of patients over a 5-year follow up period.Procedural AF non-termination and specific baseline factors predict long-term outcome after ablation.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

INTRODUCTION Mitral isthmus (MI) ablation is an effective option in patients undergoing ablation for persistent atrial fibrillation (AF). Achieving bidirectional conduction block across the MI is challenging, and predictors of MI ablation success remain incompletely understood. We sought to determine the impact of anatomical location of the ablation line on the efficacy of MI ablation. METHODS AND RESULTS A total of 40 consecutive patients (87% male; 54 ± 10 years) undergoing stepwise AF ablation were included. MI ablation was performed in sinus rhythm. MI ablation was performed from the left inferior PV to either the posterior (group 1) or the anterolateral (group 2) mitral annulus depending on randomization. The length of the MI line (measured with the 3D mapping system) and the amplitude of the EGMs at 3 positions on the MI were measured in each patient. MI block was achieved in 14/19 (74%) patients in group 1 and 15/21 (71%) patients in group 2 (P = NS). Total MI radiofrequency time (18 ± 7 min vs. 17 ± 8 min; P = NS) was similar between groups. Patients with incomplete MI block had a longer MI length (34 ± 6 mm vs. 24 ± 5 mm; P < 0.001), a higher bipolar voltage along the MI (1.75 ± 0.74 mV vs. 1.05 ± 0.69 mV; P < 0.01), and a longer history of continuous AF (19 ± 17 months vs. 10 ± 10 months; P < 0.05). In multivariate analysis, decreased length of the MI was an independent predictor of successful MI block (OR 1.5; 95% CI 1.1-2.1; P < 0.05). CONCLUSIONS Increased length but not anatomical location of the MI predicts failure to achieve bidirectional MI block during ablation of persistent AF.