966 resultados para pharmaceutical drugs
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The trypanosomatid cytoskeleton is responsible for the parasite's shape and it is modulated throughout the different stages of the parasite's life cycle. When parasites are exposed to media with reduced osmolarity, they initially swell, but subsequently undergo compensatory shrinking referred to as regulatory volume decrease (RVD). We studied the effects of anti-microtubule (Mt) drugs on the proliferation of Leishmania mexicana promastigotes and their capacity to undergo RVD. All of the drugs tested exerted antiproliferative effects of varying magnitudes [ansamitocin P3 (AP3)> trifluoperazine > taxol > rhizoxin > chlorpromazine]. No direct relationship was found between antiproliferative drug treatment and RVD. Similarly, Mt stability was not affected by drug treatment. Ansamitocin P3, which is effective at nanomolar concentrations, blocked amastigote-promastigote differentiation and was the only drug that impeded RVD, as measured by light dispersion. AP3 induced 2 kinetoplasts (Kt) 1 nucleus cells that had numerous flagella-associated Kts throughout the cell. These results suggest that the dramatic morphological changes induced by AP3 alter the spatial organisation and directionality of the Mts that are necessary for the parasite's hypotonic stress-induced shape change, as well as its recovery.
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Stimulation of erythropoiesis is one of the most efficient ways of doping. This type of doping is advantageous for aerobic physical exercise and of particular interest to endurance athletes. Erythropoiesis, which takes place in bone marrow, is under the control of EPO, a hormone secreted primarily by the kidneys when the arterial oxygen tension decreases. In certain pathological disorders, such as chronic renal failure, the production of EPO is insufficient and results in anemia. The pharmaceutical industry has, thus, been very interested in developing drugs that stimulate erythropoiesis. With this aim, various strategies have been, and continue to be, envisaged, giving rise to an expanding range of drugs that are good candidates for doping. Anti-doping control has had to deal with this situation by developing appropriate methods for their detection. This article presents an overview of both the drugs and the corresponding methods of detection, and thus follows a roughly chronological order.
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BACKGROUND Functional brain images such as Single-Photon Emission Computed Tomography (SPECT) and Positron Emission Tomography (PET) have been widely used to guide the clinicians in the Alzheimer's Disease (AD) diagnosis. However, the subjectivity involved in their evaluation has favoured the development of Computer Aided Diagnosis (CAD) Systems. METHODS It is proposed a novel combination of feature extraction techniques to improve the diagnosis of AD. Firstly, Regions of Interest (ROIs) are selected by means of a t-test carried out on 3D Normalised Mean Square Error (NMSE) features restricted to be located within a predefined brain activation mask. In order to address the small sample-size problem, the dimension of the feature space was further reduced by: Large Margin Nearest Neighbours using a rectangular matrix (LMNN-RECT), Principal Component Analysis (PCA) or Partial Least Squares (PLS) (the two latter also analysed with a LMNN transformation). Regarding the classifiers, kernel Support Vector Machines (SVMs) and LMNN using Euclidean, Mahalanobis and Energy-based metrics were compared. RESULTS Several experiments were conducted in order to evaluate the proposed LMNN-based feature extraction algorithms and its benefits as: i) linear transformation of the PLS or PCA reduced data, ii) feature reduction technique, and iii) classifier (with Euclidean, Mahalanobis or Energy-based methodology). The system was evaluated by means of k-fold cross-validation yielding accuracy, sensitivity and specificity values of 92.78%, 91.07% and 95.12% (for SPECT) and 90.67%, 88% and 93.33% (for PET), respectively, when a NMSE-PLS-LMNN feature extraction method was used in combination with a SVM classifier, thus outperforming recently reported baseline methods. CONCLUSIONS All the proposed methods turned out to be a valid solution for the presented problem. One of the advances is the robustness of the LMNN algorithm that not only provides higher separation rate between the classes but it also makes (in combination with NMSE and PLS) this rate variation more stable. In addition, their generalization ability is another advance since several experiments were performed on two image modalities (SPECT and PET).
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INTRODUCTION Vitamin D deficiency produces inadequate bone mineralization, proximal muscle weakness, abnormal gait and increased risk of falls and fractures. Moreover, in epidemiological studies, has been associated with increased risk of cancer, autoimmune diseases, type 1 and 2 diabetes, rheumatoid arthritis, multiple sclerosis, infectious diseases, cardiovascular diseases and depression. When synthesis through the skin by sun exposure is not possible and the patient can not eat by mouth, as in the advanced stages of various neurological diseases, the supply of vitamin D has to be done by enteral nutrition. OBJECTIVES The aim of this study is to review the role of vitamin D in a common group of neurological conditions that often require artificial nutrition and analyze whether the vitamin D of different enteral nutrition formulas is adequate to meet the needs of this group of patients. RESULTS Numerous studies have shown the association between vitamin D deficiency and increased incidence of dementia, stroke and other neurodegenerative diseases. Interventions aimed to increase levels of vit. D and its effects on functional (falls, pain, quality of life) and cardiovascular goals (cardiovascular death, stroke, myocardial infarction, cardiovascular risk factors) have obtained as highlight data a clear reduction of falls and fractures, while the evidence for the other parameters studied is still limited and inconsistent. The content of calcium and vitamin D of enteral formulas is legislated in our country. The total amount of vitamin D for a daily intake of 1,500-2,000 kcal ranges between 300 and 1,600 IU/d (mean ± SD: 32.9 ± 8.5 mg/100 kcal) in the complete formulas for enteral nutrition most commonly used. 50% of the diets studied, for an intake of 2,000 kcal/d, and 90% for an intake of 1,500 kcal/d, provide less than 600 IU/d of vitamin D. DISCUSSION Some revised recently guidelines published recommendations of daily intake of vitamin D. The document published by the U.S. Institute of Medicine recommended for adults between 19 and 70 years, 600 IU/d and up from 70, proposes 800 IU/d of vitamin D. These amounts are deemed insufficient by other scientific societies to state that to achieve blood levels of 25 (OH) D equal or greater than 30 ng/ml may be required a daily intake of 1,500-2,000 IU and a number two or three times higher if previous deficiency exists. CONCLUSIONS Further controlled studies are needed to ascertain which is the appropriate dose of vitamin D in advanced stages of neurological disease, where sun exposure is difficult and unlikely. We suggest that the vitamin D content should probably be reconsidered in enteral nutrition formulas, which, in light of recent publications appear as clearly insufficient for standard energy intakes (1,500-2,000 kcal).
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BACKGROUND Persistence of anti-tumor necrosis factor (TNF) therapy in rheumatoid arthritis (RA) is an overall marker of treatment success. OBJECTIVE To assess the survival of anti-TNF treatment and to define the potential predictors of drug discontinuation in RA, in order to verify the adequacy of current practices. DESIGN An observational, descriptive, longitudinal, retrospective study. SETTING The Hospital Clínico Universitario de Valladolid, Valladolid, Spain. PATIENTS RA patients treated with anti-TNF therapy between January 2011 and January 2012. MEASUREMENTS Demographic information and therapy assessments were gathered from medical and pharmaceutical records. Data is expressed as means (standard deviations) for quantitative variables and frequency distribution for qualitative variables. Kaplan-Meier survival analysis was used to assess persistence, and Cox multivariate regression models were used to assess potential predictors of treatment discontinuation. RESULTS In total, 126 treatment series with infliximab (n = 53), etanercept (n = 51) or adalimumab (n = 22) were administered to 91 patients. Infliximab has mostly been used as a first-line treatment, but it was the drug with the shortest time until a change of treatment. Significant predictors of drug survival were: age; the anti-TNF agent; and the previous response to an anti-TNF drug. LIMITATION The small sample size. CONCLUSION The overall efficacy of anti-TNF drugs diminishes with time, with infliximab having the shortest time until a change of treatment. The management of biologic therapy in patients with RA should be reconsidered in order to achieve disease control with a reduction in costs.
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Mice infected with Schistosoma mansoni were treated with oxamniquine, praziquantel, artesunate at the pre-patent phase, aiming at observing schistogram alterations. Half of the animals were perfused five days post-treatment for counting and classification of immature worms, based on pre-established morphological criteria (schistogram); the remaining animals were evaluated 42 or 100 days after infection and perfusion of the portal-system was performed for collection and counting of adult worms and oogram. It was observed that oxamniquine and artesunate treatment administered at the pre-postural phase causes significant reduction in the number of immature and adult worms. However, there was little reduction with praziquantel when used at the dose of 400 mg/kg for treatments administered 14, 15, 21 or 23 days post-infection. Artesunate was responsible for significant alterations in development of young worms, as well as for a higher number of worms presenting intestinal damages. Immature adult worms were detected in mice treated with artesunate or oxamniquine at the pre-patent phase of infection and recovered by perfusion 100 days after infection. Schistogram proved to be a very useful tool for experimental evaluation of the activity of antischistosomal drugs and a good model to identify the most sensitive stages to drugs.
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Nonimmediate drug hypersensitivity reactions (DHRs) are difficult to manage in daily clinical practice, mainly owing to their heterogeneous clinical manifestations and the lack of selective biological markers. In vitro methods are necessaryto establish a diagnosis, especially given the low sensitivity of skin tests and the inherent risks of drug provocation testing. In vitro evaluation of nonimmediate DHRs must include approaches that can be applied during the different phases of the reaction. During the acute phase, monitoring markers in both skin and peripheral blood helps to discriminate between immediate and nonimmediate DHRs with cutaneous responses and to distinguish between reactions that, although they present similar clinical symptoms, are produced by different immunological mechanisms and therefore have a different treatment and prognosis. During the resolution phase, in vitro testing is used to detect the response of T cells to drug stimulation; however, this approach has certain limitations, such as the lack of validated studies assessing sensitivity. Moreover, in vitro tests indicate an immune response that is not always related to a DHR. In this review, members of the Immunology and Drug Allergy Committee of the Spanish Society of Allergy and Clinical Immunology (SEAIC) provide an overview of the most widely used in vitro tests for evaluating nonimmediate DHRs.
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Raman spectroscopy has become an attractive tool for the analysis of pharmaceutical solid dosage forms. In the present study it is used to ensure the identity of tablets. The two main applications of this method are release of final products in quality control and detection of counterfeits. Twenty-five product families of tablets have been included in the spectral library and a non-linear classification method, the Support Vector Machines (SVMs), has been employed. Two calibrations have been developed in cascade: the first one identifies the product family while the second one specifies the formulation. A product family comprises different formulations that have the same active pharmaceutical ingredient (API) but in a different amount. Once the tablets have been classified by the SVM model, API peaks detection and correlation are applied in order to have a specific method for the identification and allow in the future to discriminate counterfeits from genuine products. This calibration strategy enables the identification of 25 product families without error and in the absence of prior information about the sample. Raman spectroscopy coupled with chemometrics is therefore a fast and accurate tool for the identification of pharmaceutical tablets.
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The treatment of essential hypertension is based essentially on the prescription of four major classes of antihypertensive drugs, i.e. blockers of the renin-angiotensin system, calcium channel blockers, diuretics and beta-blockers. In recent years, very few new drug therapies of hypertension have become available. Therefore, it is crucial for physicians to optimize their antihypertensive therapies with the drugs available on the market. In each of the classes of antihypertensive drugs, questions have recently been raised: are angiotensin-converting enzyme (ACE) inhibitors superior to angiotensin II receptor blockers (ARB)? Is it possible to reduce the incidence of peripheral oedema with calcium antagonists? Is hydrochlorothiazide really the good diuretic to use in combination therapies? The purpose of this review is to discuss these various questions in the light of the most recent clinical studies and meta-analyses. These latter suggest that ACE inhibitors and ARB are equivalent except for a better tolerability profile of ARB. Third generation calcium channel blockers enable to reduce the incidence of peripheral oedema and chlorthalidone is certainly more effective than hydrochlorothiazide in preventing cardiovascular events in hypertension. At last, studies suggest that drug adherence and long-term persistence under therapy is one of the major issues in the actual management of essential hypertension.
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Purpose. To survey the management of patients with neovascular age-related macular degeneration (nvAMD) in Spain. Methods. An observational retrospective multicenter study was conducted. The variables analyzed were sociodemographic characteristics, foveal and macular thickness, visual acuity (VA), type of treatment, number of injections, and the initial administration of a loading dose of an antiangiogenic drug. Results. 208 patients were followed up during 23.4 months in average. During the first and second years, patients received a mean of 4.5 ± 1.8 and 1.6 ± 2.1 injections of antiangiogenic drugs, and 5.4 ± 2.8 and 3.6 ± 2.2 follow-up visits were performed, respectively. The highest improvement in VA was observed at 3 months of follow-up, followed by a decrease in the response that stabilized above baseline values until the end of the study. Patients who received an initial loading dose presented greater VA gains than those without. Conclusions. Our results suggest the need for a more standardized approach in the management and diagnosis of nvAMD receiving VEGF inhibitors. To achieve the visual outcomes reported in pivotal trials, an early diagnosis, proactive approach (more treating than follow-up visits), and a close monitoring might be the key to successfully manage nvAMD.
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Cornea transplantation is one of the most performed graft procedures worldwide with an impressive success rate of 90%. However, for "high-risk" patients with particular ocular diseases in addition to the required surgery, the success rate is drastically reduced to 50%. In these cases, cyclosporin A (CsA) is frequently used to prevent the cornea rejection by a systemic treatment with possible systemic side effects for the patients. To overcome these problems, it is a challenge to prepare well-tolerated topical CsA formulations. Normally high amounts of oils or surfactants are needed for the solubilization of the very hydrophobic CsA. Furthermore, it is in general difficult to obtain ocular therapeutic drug levels with topical instillations due to the corneal barriers that efficiently protect the intraocular structures from foreign substances thus also from drugs. The aim of this study was to investigate in vivo the effects of a novel CsA topical aqueous formulation. This formulation was based on nanosized polymeric micelles as drug carriers. An established rat model for the prevention of cornea graft rejection after a keratoplasty procedure was used. After instillation of the novel formulation with fluorescent labeled micelles, confocal analysis of flat-mounted corneas clearly showed that the nanosized carriers were able to penetrate into all corneal layers. The efficacy of a 0.5% CsA micelle formulation was tested and compared to a physiological saline solution and to a systemic administration of CsA. In our studies, the topical CsA treatment was carried out for 14 days, and the three parameters (a) cornea transparency, (b) edema, and (c) neovascularization were evaluated by clinical observation and scoring. Compared to the control group, the treated group showed a significant higher cornea transparency and significant lower edema after 7 and 13 days of the surgery. At the end point of the study, the neovascularization was reduced by 50% in the CsA-micelle treated animals. The success rate of cornea graft transplantation was 73% in treated animals against 25% for the control group. This result was as good as observed for a systemic CsA treatment in the same animal model. This new formulation has the same efficacy like a systemic treatment but without the serious CsA systemic side effects. Ocular drug levels of transplanted and healthy rat eyes were dosed by UPLC/MS and showed a high CsA value in the cornea (11710 ± 7530 ng(CsA)/g(tissue) and 6470 ± 1730 ng(CsA)/g(tissue), respectively). In conclusion, the applied formulation has the capacity to overcome the ocular surface barriers, the micelles formed a drug reservoir in the cornea from, where a sustained release of CsA can take place. This novel formulation for topical application of CsA is clearly an effective and well-tolerated alternative to the systemic treatment for the prevention of corneal graft rejection.
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Background: Current guidelines underline the limitations of existing instruments to assess fitness to drive and the poor adaptability of batteries of neuropsychological tests in primary care settings. Aims: To provide a free, reliable, transparent computer based instrument capable of detecting effects of age or drugs on visual processing and cognitive functions. Methods: Relying on systematic reviews of neuropsychological tests and driving performances, we conceived four new computed tasks measuring: visual processing (Task1), movement attention shift (Task2), executive response, alerting and orientation gain (Task3), and spatial memory (Task4). We then planned five studies to test MedDrive's reliability and validity. Study-1 defined instructions and learning functions collecting data from 105 senior drivers attending an automobile club course. Study-2 assessed concurrent validity for detecting minor cognitive impairment (MCI) against useful field of view (UFOV) on 120 new senior drivers. Study-3 collected data from 200 healthy drivers aged 20-90 to model age related normal cognitive decline. Study-4 measured MedDrive's reliability having 21 healthy volunteers repeat tests five times. Study-5 tested MedDrive's responsiveness to alcohol in a randomised, double-blinded, placebo, crossover, dose-response validation trial including 20 young healthy volunteers. Results: Instructions were well understood and accepted by all senior drivers. Measures of visual processing (Task1) showed better performances than the UFOV in detecting MCI (ROC 0.770 vs. 0.620; p=0.048). MedDrive was capable of explaining 43.4% of changes occurring with natural cognitive decline. In young healthy drivers, learning effects became negligible from the third session onwards for all tasks except for dual tasking (ICC=0.769). All measures except alerting and orientation gain were affected by blood alcohol concentrations. Finally, MedDrive was able to explain 29.3% of potential causes of swerving on the driving simulator. Discussion and conclusions: MedDrive reveals improved performances compared to existing computed neuropsychological tasks. It shows promising results both for clinical and research purposes.
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PURPOSE: The perioperative treatment of patients on dual antiplatelet therapy after myocardial infarction, cerebrovascular event or coronary stent implantation represents an increasingly frequent issue for urologists and anesthesiologists. We assess the current scientific evidence and propose strategies concerning treatment of these patients. MATERIALS AND METHODS: A MEDLINE and PubMed search was conducted for articles related to antiplatelet therapy after myocardial infarction, coronary stents and cerebrovascular events, as well as the use of aspirin and/or clopidogrel in the context of surgery. RESULTS: Early discontinuation of antiplatelet therapy for secondary prevention is associated with a high risk of coronary thrombosis, which is further increased by the hypercoagulable state induced by surgery. Aspirin has recently been recommended as a lifelong therapy. Clopidogrel is mandatory for 6 weeks after myocardial infarction and bare metal stents, and for 12 months after drug-eluting stents. Surgery must be postponed beyond these waiting periods or performed with patients receiving dual antiplatelet therapy because withdrawal therapy increases 5 to 10 times the risk of postoperative myocardial infarction, stent thrombosis or death. The shorter the waiting period between revascularization and surgery the greater the risk of adverse cardiac events. The risk of surgical hemorrhage is increased approximately 20% by aspirin and 50% by clopidogrel. CONCLUSIONS: The risk of coronary thrombosis when antiplatelet agents are withdrawn before surgery is generally higher than the risk of surgical hemorrhage when antiplatelet agents are maintained. However, this issue has not yet been sufficiently evaluated in urological patients and in many instances during urological surgery the risk of bleeding can be dangerous. A thorough dialogue among surgeon, cardiologist and anesthesiologist is essential to determine all risk factors and define the best possible strategy for each patient.
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OBJETIVE: To report the data of the Home Parenteral Nutrition (HPN) registry of the NADYA-SENPE working group for the years 2011 and 2012. METHODOLOGY: We compiled the data from the on-line registry introduced by reviewers of NADYA group responsible for monitoring of NPD introduced by since January 1, 2011 to december 31, 2012. Included fields were: age, sex, diagnosis and reason for HPN, access path, complications, beginning and end dates, complementary oral or enteral nutrition, activity level, autonomy degree, product and fungible material supply, withdrawal reason and intestinal transplant indication. RESULTS: Year 2010: 184 patients from 29 hospitals , representing a rate of 3.98 patients/million inhabitants/ year 2011, with 186 episodes were recorded NPD . During 2012, 203 patients from 29 hospitals , representing a rate of 4.39 patients/million inhabitants/year 2012 , a total of 211 episodes were recorded NPD . CONCLUSIONS: We observe an increase in registered patients with respect to previous years.Neoplasia remains as the main pathology since 2003. Although NADYA is consolidated registry and has been indispensable source of information relevant to the understanding of the progress of Home Artificial Nutrition in our country, there is ample room for improvement. Especially that refers to the registration of pediatric patients and the registration of complications.
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Objectives: To measure the positive predictive value (PPV) of the cost of drug therapy (threshold = 2000 Swiss francs [CHF], US$1440, <euro>1360) as a screening criterion for identifying patients who may benefit from medication review (MR). To describe identified drug-related problems (DRPs) and expense problems (EPs), and to estimate potential savings if all recommendations were accepted. Setting Five voluntary Swiss community pharmacies. Methods: Of 12,680 patients, 592 (4.7%) had drug therapy costs exceeding 2000 CHF over a six-month period from July 1 to December 31, 2002. This threshold limit was set to identify high-risk patients for DRPs and EPs. Three pharmacists consecutively conducted a medication review based on the pharmaceutical charts of 125 sampled patients who met the inclusion criterion. Main outcome measure: The PPV of a threshold of 2000 CHF for identifying patients who might benefit from a MR: true positives were patients with at least one DRP, while false positives were patients with no DRP. Results: The selection based on this criterion had a PPV of 86% for detecting patients with at least one DRP and 95% if EPs were also considered. There was a mean of 2.64 (SD = 2.20) DRPs per patient and a mean of 2.14 (SD = 1.39) EPs per patient. Of these patients, 90% were over 65 years old or were treated with at least five chronic medications, two common criteria for identifying patients at risk of DRPs. The main types of DRPs were drug-drug interactions, compliance problems and duplicate drugs. Mean daily drug cost per patient was CHF 14.87 (US$10.70, <euro>10.10). A potential savings of CHF 1.67 (US$1.20, <euro>1.14) per day (11%) was estimated if all recommendations to solve DRPs and EPs suggested herein were implemented. Conclusion: Further studies should investigate whether the potential benefit of medication reviews in preventing DRPs and containing costs in this patient group can be confirmed in a real practice environment. [Authors]