Association between plasma imatinib levels and response to treatment of chronic myeloid leukemia in patients from Manaus, Brazil.

INTRODUCTION: Imatinib mesylate (IM) is the drug of choice for the treatment of chronic myeloid leukemia (CML). However, despite most of the results obtained with this therapy being positive, some patients still present a suboptimal therapeutic response or still develop some type of resistance. Therefore, the aim of this study was to evaluate IM plasma levels in CML patients treated at a referral unit in Manaus and correlate them with variables that might interfere with these levels. METHODS: Data from 52 patients were obtained through a standardized questionnaire containing clinical, sociodemographic, lifestyle, and use of other medication information, as well as an estimate of therapeutic adherence. Additionally, blood collection was performed to measure the plasma concentration of the drug using the HPLC-UV technique. Molecular studies were done to identify the presence of polymorphism in the ABCG2 C421A membrane transporter. RESULTS: Most patients were male with a mean age of 52 ± 12.3 years (95% CI 49.0-55.9). There was a high variation in drug concentrations in the range from 0 to 4694 ng/mL, with a mean of 1558.59 ± 989.79 ng/mL (95% CI 1283.0-1834.1). CONCLUSION: Approximately two-thirds of patients were classified in the drug-level range considered therapeutic, and there was a correlation between plasma concentration and higher molecular response. Additionally, most individuals had the normal genotype for the ABCG2 C421A polymorphism but further studies should be performed to reveal the role of this variable in the outcome of the disease in this population.

Changes in the input-output relation of the Hoffmann reflex recruitment curve after submaximal fatiguing contraction of the antagonist muscles.

PURPOSE: The central nervous system adapts strategies to compensate the decreased motor capacities of a fatigued muscle. However, data on neurophysiological adaptations of muscles other than those under fatigue are scarce. The present study was designed to evaluate the effects of submaximal fatiguing contraction (leading to a task failure) induced in ankle dorsiflexors muscles on the excitability of the Hoffmann reflex (H-reflex) of an ankle plantarflexor (soleus muscle). MATERIALS AND METHODS: Twenty-three physically active males (75.5 ± 8.3 kg; 1.77 ± 0.08 m; 27.0 ± 8.0 years) were asked to maintain the contraction level of the right ankle dorsiflexors at 60% of the maximal isometric voluntary contraction (MIVC). Task failure was defined when the force level dropped below 40% MIVC for 5 consecutive seconds. The input-output relation of the ascending limb of the recruitment curve of the soleus H-reflex was examined at 0 min, 5 min, 10 min, 15 min and 20 min after the task failure. RESULTS: The amplitude parameter representing the first recruited motoneurons (threshold H-reflex - H@th) was significantly higher at 5 min, 10 min, 15 min and 20 min after task failure as compared to control (Hth) (p < 0.05). On the other hand, the parameter that represents the activation of the relatively higher threshold motoneurons (H@100) was reduced (as compared to control - H100), but only at 20 min after the task failure (p < 0.05). CONCLUSIONS: These results suggest differential reflex modulation of the soleus H-reflex after fatigue of the ankle dorsiflexors, that probably reflects neuronal adaptations underlying motor control around the ankle joint.

Therapeutic Elastic Tapes Applied in Different Directions Over the Triceps Surae Do Not Modulate Reflex Excitability of the Soleus Muscle.

CONTEXT: Elastic taping has been widely used for either to facilitate or to inhibit muscle contraction. The efficacy of elastic taping is allegedly ascribed to physiological mechanisms related to subcutaneous tissue and muscle stimulation as a result of tape tension and direction. However, the underlying mechanisms that support the use of elastic taping are still unclear. OBJECTIVE: To investigate changes in electrophysiological responses after 48 hours of tape application in different directions on the calf muscles of healthy individuals. DESIGN: Within-subjects design. SETTING: Research laboratory. PARTICIPANTS: Twenty-seven physically active males (age 18.0 [4.2] y, height 1.65 [0.07] m, body mass 62.3 [10.3] kg) participated. INTERVENTIONS: Soleus H-reflex responses were evoked through stimulation of the tibial posterior nerve with 2- to 4-second interval between stimuli (32 sweeps) for each condition (baseline: without tape; facilitation: tape applied from muscle origin to insertion; inhibition: tape applied from muscle insertion to origin). MAIN OUTCOME MEASURES: The H-reflex amplitude values were normalized by the maximal direct response (Mmax). Parameters were estimated from a sigmoidal fit of the H-reflex recruitment curve (ascending limb). RESULTS: No significant differences were found for the parameters derived from the recruitment curve of the H-reflex among the conditions (P > .05). CONCLUSIONS: The authors' findings showed that, irrespective of the direction of tape application, the elastic tape applied over the triceps surae does not generate any significant alteration on the excitability of the reflex pathway for different subpopulations of motor units. The authors therefore suggest a re-examination of the current recommendations on taping direction in clinical and sports activities.

Diversity of metallo-ß-lactamase-encoding genes found in distinct species of Acinetobacter isolated from the Brazilian Amazon Region.

BACKGROUND: The multidrug resistance (MDR) phenotype is frequently observed in Acinetobacter baumannii, the most clinically relevant pathogenic species of its genus; recently, other species belonging to the A. calcoaceticus-A. baumannii complex have emerged as important MDR nosocomial pathogens. OBJECTIVES: The present study aimed to verify the occurrence of metallo-ß-lactamase genes among distinct Acinetobacter species in a hospital located in the Brazilian Amazon Region. METHODS: Antimicrobial susceptibility profiles were determined by broth microdilution. The genetic relationships among these isolates were assessed by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Pyrosequencing reads of plasmids carrying the bla NDM-1 gene were generated using the Ion Torrent™ platform sequencing. FINDINGS: A total of six isolates carried bla NDM-1: A. baumannii (n = 2), A. nosocomialis (n = 3), and A. pittii (n = 1); three carried bla IMP-1: A. baumannii, A. nosocomialis, and A. bereziniae. Resistance to colistin was observed for an NDM-1-producing A. nosocomialis isolate. Diverse PFGE patterns and sequence types were found among A. nosocomialis and A. baumannii isolates. The bla NDM-1 sequence was inserted in a Tn125 transposon, while the bla IMP-1 was found as a gene cassette of the class 1 integron In86. MAIN CONCLUSIONS: To the best of our knowledge, this is the first report describing the dissemination of bla NDM-1 among distinct Acinetobacter species recovered from the same hospital in South America.

Population Pharmacokinetic Model of Piperacillin in Critically Ill Patients and Describing Interethnic Variation Using External Validation.

Objectives: This study aimed to develop a piperacillin population PK model for critically ill Brazil-ian patients and describe interethnic variation using an external validation. Methods: Plasma samples were obtained from 24 ICU patients during the fifth day of piperacillin treatment and assayed by HPLC-UV. Population pharmacokinetic modelling was conducted using Pmetrics. Empiric dose of 4 g IV 6- and 8-hourly were simulated for 50 and 100% fT > MIC and the probabil-ity of target attainment (PTA) and the fractional target attainment (FTA) determined. Results: A two-compartment model was designed to describe the pharmacokinetics of critically ill Brazillian patients. Clearance and volume of distribution were (mean ± SD) 3.33 ± 1.24 L h−1 and 10.69 ± 4.50 L, respectively. Creatinine clearance was positively correlated with piperacillin clearance and a high creatinine clearance was associated with lower values of PTA and FTA. An external vali-dation was performed using data from two different ethnic ICU populations (n = 30), resulting in acceptable bias and precision. Conclusion: The primary pharmacokinetic parameters obtained from critically ill Brazilian patients were similar to those observed in studies performed in critically ill patients of other ethnicities. Based on our results, the use of dose adjustment based on creati-nine clearance is required in Brazilian patients.

Two-step liquid-phase microextraction and high-performance liquid chromatography for the simultaneous analysis of the enantiomers of mefloquine and its main metabolite carboxymefloquine in plasma.

A method for the simultaneous analysis of the enantiomers of mefloquine (MQ) and its main metabolite carboxymefloquine (CMQ) in plasma is described for the first time. The assay involves two-step liquid-phase microextraction (LPME) and enantioselective high-performance liquid chromatography. In the first LPME step, the enantiomers of MQ were extracted from an alkalinized sample through a thin layer of di-n-hexyl ether immobilized in the pores of the hollow fiber and into 0.01 M perchloric acid as acceptor solution. In the second LPME step, the same sample was acidified to enable the extraction of CMQ using the same organic solvent and 0.05 M sodium hydroxide as acceptor phase. The analytes were resolved on a Chirobiotic T column in the polar-organic mode of elution and detected at 285 nm. The recovery rates from 1 mL of plasma were in the range 35-38%. The method presented limits of quantification of 50 ng/mL for all analytes and was linear up to 1,500 and 3,000 ng/mL for the enantiomers of MQ and CMQ, respectively. The plasmatic concentrations of (+)-(RS)-MQ were higher than those of (-)-(SR)-MQ after oral administration of the racemic drug to rats.

Enantioselective determination of chloroquine and its n-dealkylated metabolites in plasma using liquid-phase microextraction and LC-MS.

A selective method using three-phase liquid-phase microextraction (LPME) in conjunction with LC-MS-MS was devised for the enantioselective determination of chloroquine and its n-dealkylated metabolites in plasma samples. After alkalinization of the samples, the analytes were extracted into n-octanol immobilized in the pores of a polypropylene hollow fiber membrane and back extracted into the acidic acceptor phase (0.1 M TFA) filled into the lumen of the hollow fiber. Following LPME, the analytes were resolved on a Chirobiotic V column using methanol/ACN/glacial acetic acid/diethylamine (90:10:0.5:0.5 by volume) as the mobile phase. The MS detection was carried out using multiple reaction monitoring with ESI in the positive ion mode. The optimized LPME method yielded extraction recoveries ranging from 28 to 66%. The method was linear over 5-500 ng/mL and precision (RSD) and accuracy (relative error) values were below 15% for all analytes. The developed method was applied to the determination of the analytes in rat plasma samples after oral administration of the racemic drug.

Liquid-phase microextraction combined with high-performance liquid chromatography for the enantioselective analysis of mefloquine in plasma samples.

A simple and rapid method, which involves liquid-phase microextraction (LPME) followed by HPLC analysis using Chiralpak AD column and UV detection, was developed for the enantioselective determination of mefloquine in plasma samples. Several factors that influence the efficiency of three-phase LPME were investigated and optimized. Under the optimal extraction conditions, the mean recoveries were 33.2 and 35.0% for (-)-(SR-)-mefloquine and (+)-(RS)-mefloquine, respectively. The method was linear over 50-1500 ng/ml range. Within-day and between-day assay precision and accuracy were below 15% for both enantiomers at concentrations of 150, 600 and 1200 ng/ml. Furthermore, no racemization or degradation were seen with the method described.

Genetic polymorphisms of CYP2B6*6, CYP2C8*3 and CYP2D6*4 in vivax malaria patients from Brazilian Amazon

Abstract Genetic variability in the host metabolism of antimalarial drugs influenced by the polymorphisms of cytochrome P450 (CYP) could lead to significant changes in antimalarial treatment response. However, little is known about the frequency of alleles CYP2B6, CYP2C8, and CYP2D6 in an Amazonian population, especially with vivax malaria. Therefore, this study aimed to determine the frequency of CYP alleles CYP2B6*6, CYP2C8*3, and CYP2D6*4 in patients with vivax malaria. The study included 231 patients with vivax malaria treated at a health care reference in Manaus, northern Brazil. A sample of peripheral blood from each subject was collected to perform DNA extraction and genotypic analysis. Genotyping of polymorphisms was performed by allelic discrimination using Real-time polymerase chain reaction. The CYP2D6*4 allele was the most prevalent among patients who developed severe malaria. The frequencies of the CYP2B6*6 and CYP2D6*4 were not different between the severe and uncomplicated malaria. There was a significant association between heterozygous CYP2D6*4 and severe cases of malaria. The results are in agreement with other reports described in the literature for different populations. Future studies are needed to understand the clinical implications of the polymorphisms in patients with vivax malaria.

[Use of psychoactive drugs by health sciences undergraduate students at the Federal University in Amazonas, Brazil]. / Uso de psicotrópicos entre universitários da área da saúde da Universidade Federal do Amazonas, Brasil.

A survey was conducted with 521 undergraduate health sciences students from the Federal University in Amazonas, Manaus, Brazil. Lifetime alcohol consumption was reported by 87.7% students, as compared to 30.7% for tobacco, with the latter reported more frequently by males (39.7%). The most common illicit drugs were solvents (11.9%), marijuana (9.4%), amphetamines and anxiolytics (9.2% each), cocaine (2.1%), and hallucinogens (1.2%). The main reason for illicit drug use was curiosity. Lifetime use of anabolic steroids was reported by 2.1% of the students. Alcohol abuse in the previous 30 days was reported by 12.4% of the students. Events following drinking included: fights (4.7%), accidents (2.4%), classroom absenteeism (33.7%), and job absenteeism (11.8%). Another important finding was that 47.3% of students drove after drinking. Opinions on drug abuse and patterns agree with those from similar studies in other regions of Brazil.

Prolonged use of Kinesiotaping does not enhance functional performance and joint proprioception in healthy young males: Randomized controlled trial.

OBJECTIVES: The aim of this study was to investigate the effects of continuous (48-hour) use of Kinesiotaping (KT) on functional and proprioceptive performance in healthy, physically active men. METHOD: Twenty-six healthy, physically active men (21.8±2.2 years old) were randomly allocated into two groups: 1) Kinesiotaping group (KG, tape applied with 40% tension for rectus femoris activation); 2) Control (CG, tape applied over rectus femoris without additional tension). Subjects attended the laboratory on five separate occasions: 1) familiarization; 2) baseline measurement without tape (BL); 3) immediately post-tape application (T0); 4) 24h (T24); and 5) 48h (T48) post-tape application. The outcomes were distance in the single (SHT) and triple hop tests (THT), vertical jump height (VJH), vertical jump power (VJP), and rate of force development (RFD). A mixed-model ANOVA was applied to verify differences between and within groups. RESULTS: No significant (p >0.05) differences were found in the SHT and THT between groups and moments. Likewise, the main effects for VJH, VJP, and RFD were not significant (p >0.05). CONCLUSION: The present study demonstrated no significant immediate or prolonged (48h) effects of KT on functional and proprioceptive performance.

Kinesiotaping enhances the rate of force development but not the neuromuscular efficiency of physically active young men.

INTRODUCTION: Investigations on the effects of KT on human performance have been increasing in the last few years. However, there is a paucity of studies investigating its effects on neuromuscular efficiency (NME) and rate of force development (RFD). OBJECTIVE: To evaluate the NME and RFD of the soleus and gastrocnemius muscles in physically active individuals under KT application. METHOD: Twenty young males (79.7±8.2kg; 1.78±0.05m; 24.7±4.4years) performed three conditions in a randomized order: (1) Baseline (BL, no tape); (2) Activation (ACTIKT, tape for muscle activation); and (3) Inhibition (INHIKT, tape for muscle inhibition). The tape was applied along the lateral and medial border of gastrocnemius with 30% tension for 48h. Peak torque (PT), RFD and NME were measured at BL and 48h after ACTIKT and INHIKT by performing a maximum isometric contraction. RESULTS: The RFD was significantly higher in ACTIKT compared to BL at 0-30 (P=0.010), 0-50 (P=0.008) and 0-100ms (P=0.007). The PT and NME did not differ among conditions (P>0.05). CONCLUSION: KT applied for muscle activation yielded a higher RFD during the initial phase of the muscle contraction. However, KT has no enhancement effect on NME and peak torque.

Off-label and unlicensed utilization of drugs in a Brazilian pediatric hospital.

AIM: To describe the off-label and unlicensed utilization patterns of drugs in a Brazilian pediatric hospital. METHODS: The research consisted of a descriptive, prospective and cross-sectional study. RESULTS: A total of 1,158 medicines were prescribed for 320 patients, accounting for 65 different drugs. Regarding the classification of drug utilization, the majority of the drugs were prescribed as in-label (57.2%), followed by off-label (36.4%) and by unlicensed (6.3%). The prevalences of unlicensed and off-label utilization of drugs in the studied population were 20.9 and 77.8%, respectively. Polypharmacy was highly associated to both off-label and unlicensed regimen (OR 12.9; 95% CI 3.07-54.2 and OR 3.68; 95% CI 2.02-6.69, respectively) whereas preschool children were less prone to unlicensed prescription (OR 0.39; 95% CI 0.19-0.79). Sex and length of hospitalization were not related to these outcomes. CONCLUSIONS: Further studies are necessary to verify the impact of this pattern on the occurrence of adverse drug events.

Objetivo: Describir los patrones de utilizacion de medicamentos off-label y sin licencia en un hospital pediatrico de Brasil. Métodos: La investigacion consistio en un estudio descriptivo, prospectivo y de corte transversal. Resultados: Un total de 1.158 medicamentos fueron prescritos para 320 pacientes, que representan 65 farmacos diferentes. En cuanto a la clasificacion de la utilizacion de medicamentos, la mayoria de los medicamentos fueron prescritos como en la ficha tecnica (57,2%), seguido off-label (36,4%) y por sin licencia (6,3%). Las prevalencias de uso sin licencia y off-label de drogas en la poblacion estudiada fueron 20,9 y 77,8%, respectivamente. La polifarmacia fue muy asociada a ambos off-label y el regimen sin licencia (OR 12,9; IC del 95%: 3,07 a 54,2 y OR 3,68; IC del 95%: 2,02 a 6,69, respectivamente), mientras que los ninos en edad preescolar fueron menos propensos a prescripcion sin licencia (OR 0,39; 95% CI 0,19-,79). El sexo y la duracion de la hospitalizacion no estaban relacionadas con estos resultados. Conclusiones: Son necesarios mas estudios para verificar el impacto de este patron en la ocurrencia de eventos adversos en los medicamentos.

Current bioanalytical methods for pharmacokinetic studies of drugs used in neglected tropical diseases.

Neglected tropical diseases are conditions directly associated to poverty and affect millions of people in tropical areas. Considering the necessity of pharmacokinetic and therapeutic drug monitoring studies to assess the disposition of agents clinically employed in the treatment of these diseases, especially in the involved population, this article will overview the current bioanalytical methods developed in the last 10 years, particularly those fully validated and using standard techniques, such as chromatographic procedures combined or not with mass spectrometry. The characteristics of each assay reported will be summarized and critically discussed. Furthermore, emphasis will also be given to the pros and cons in order to highlight the application of each method, especially in routine laboratories.

Diversity of metallo-b-lactamase-encoding genes found in distinct species of Acinetobacter isolated from the Brazilian Amazon Region

BACKGROUND The multidrug resistance (MDR) phenotype is frequently observed in Acinetobacter baumannii, the most clinically relevant pathogenic species of its genus; recently, other species belonging to the A. calcoaceticus-A. baumannii complex have emerged as important MDR nosocomial pathogens. OBJECTIVES The present study aimed to verify the occurrence of metallo-β-lactamase genes among distinct Acinetobacter species in a hospital located in the Brazilian Amazon Region. METHODS Antimicrobial susceptibility profiles were determined by broth microdilution. The genetic relationships among these isolates were assessed by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Pyrosequencing reads of plasmids carrying the bla NDM-1 gene were generated using the Ion Torrent™ platform sequencing. FINDINGS A total of six isolates carried bla NDM-1: A. baumannii (n = 2), A. nosocomialis (n = 3), and A. pittii (n = 1); three carried bla IMP-1: A. baumannii, A. nosocomialis, and A. bereziniae. Resistance to colistin was observed for an NDM-1-producing A. nosocomialis isolate. Diverse PFGE patterns and sequence types were found among A. nosocomialis and A. baumannii isolates. The bla NDM-1 sequence was inserted in a Tn125 transposon, while the bla IMP-1 was found as a gene cassette of the class 1 integron In86. MAIN CONCLUSIONS To the best of our knowledge, this is the first report describing the dissemination of bla NDM-1 among distinct Acinetobacter species recovered from the same hospital in South America.

Prolonged use of Kinesiotaping does not enhance functional performance and joint proprioception in healthy young males: Randomized controlled trial

ABSTRACT Objectives The aim of this study was to investigate the effects of continuous (48-hour) use of Kinesiotaping (KT) on functional and proprioceptive performance in healthy, physically active men. Method Twenty-six healthy, physically active men (21.8±2.2 years old) were randomly allocated into two groups: 1) Kinesiotaping group (KG, tape applied with 40% tension for rectus femoris activation); 2) Control (CG, tape applied over rectus femoris without additional tension). Subjects attended the laboratory on five separate occasions: 1) familiarization; 2) baseline measurement without tape (BL); 3) immediately post-tape application (T0); 4) 24h (T24); and 5) 48h (T48) post-tape application. The outcomes were distance in the single (SHT) and triple hop tests (THT), vertical jump height (VJH), vertical jump power (VJP), and rate of force development (RFD). A mixed-model ANOVA was applied to verify differences between and within groups. Results No significant (p >0.05) differences were found in the SHT and THT between groups and moments. Likewise, the main effects for VJH, VJP, and RFD were not significant (p >0.05). Conclusion The present study demonstrated no significant immediate or prolonged (48h) effects of KT on functional and proprioceptive performance.

Determination of beta-artemether and its main metabolite dihydroartemisinin in plasma employing liquid-phase microextraction prior to liquid chromatographic-tandem mass spectrometric analysis.

A method for the determination of artemether (ART) and its main metabolite dihydroartemisinin (DHA) in plasma employing liquid-phase microextraction (LPME) for sample preparation prior to liquid chromatography-tandem mass spectrometry (LC-MS-MS) was developed. The analytes were extracted from 1mL of plasma utilizing a two-phase LPME procedure with artemisinin as internal standard. Using the optimized LPME conditions, mean absolute recovery rates of 25 and 32% for DHA and ART, respectively, were achieved using toluene-n-octanol (1:1, v/v) as organic phase with an extraction time of 30min. After extraction, the analytes were resolved within 5min using a mobile phase consisting of methanol-ammonium acetate (10mmolL(-1), pH 5.0, 80:20, v/v) on a laboratory-made column based on poly(methyltetradecylsiloxane) attached to a zirconized-silica support. MS-MS detection was employed using an electrospray interface in the positive ion mode. The method developed was linear over the range of 5-1000ngmL(-1) for both analytes. Precision and accuracy were within acceptable levels of confidence (<15%). The assay was applied to the determination of these analytes in plasma from rats treated with ART. The two-phase LPME procedure is affordable and the solvent consumption was very low compared to the traditional methods of sample preparation.

Determination of Cu, Fe, Mn, and Zn in the leaves and tea of Arrabidaea chica (Humb. & Bompl.) Verl.

Arrabidaea chica (Humb. & Bompl.) Verl. is an herb popularly used in the treatment of anemia in the Brazilian Amazon region, and little is known about its mineral content. Therefore, the elemental contents of Cu, Fe, Mn, and Zn were determined in the dried leaves and tea obtained by decoction and infusion of the three varieties of the medicinal plant using flame atomic absorption spectrometry after acid wet digestion of the samples. In general, the levels of the minerals are in good agreement with other studies involving medicinal plants, and the variety AC2 had the highest concentrations of all elements both in dried leaves and tea. Iron was found to be the most abundant in dried leaves (38.4-115.5 µg g(-1)), whereas manganese had the highest extraction efficiencies both in decoction (56.1-62.7%) and infusion (45.6-63.6%). Additionally, the decoction was more efficient in the extraction of almost all elements. The consumption of the decoction of variety AC2 may contribute to a small proportion to the daily requirements of Mn.

Efeitos de diferentes intervalos de recuperação no volume completado e na percepção subjetiva de esforço em homens treinados / Effects of different rest intervals in volume completed and perceived exertion in trained men

O objetivo do estudo foi comparar o efeito de dois intervalos de recuperação (IR) na cadeira extensora unilateral sobre o volume completado em três séries, no volume total de treino e na percepção subjetiva de esforço (PSE). Doze homens jovens, todos com pelo menos um ano de experiência no treinamento resistido. Os indivíduos realizaram 4 sessões de testes com intervalos de 48hs entre elas. Nas sessões 1 e 2 foram realizados teste e re-teste de 10RM. Nas sessões 3 e 4 realizaram três séries de 10RM. O IR entre as séries foram de 90 e 120s, contrabalanceados entre os dias de teste. A análise estatística foi a ANOVA de medidas repetidas. O teste T-Student para variáveis dependentes foi utilizado para comparar o somatório do volume total de treino nos dois intervalos distintos. Tanto 120 como 90s não conseguiram manter o volume ao longo das três séries, no entanto, com a utilização do IR de 120s foi possível realizar um maior volume total de treino. Em relação a PSE foram encontradas diferenças significativas intraseqüências apenas no IR90s na 3ª série quando comparada com 1ª e 2ª série de 90s, e inter sequências foram encontradas diferenças apenas com a 1ª série de 120s comparada com a 3ª série de 90s. O estudo indicou que o IR de 120s é superior ao de 90s no volume total de treino, entretanto, para manutenção do volume entre ás séries um IR superior deve ser realizado. E a utilização da PSE para identificar intensidade de esforço realizado, parece ser um bom método, visto que o IR de 90s acarretou diferenças entre as séries, o mesmo não aconteceu quando o IR de 120s foi utilizado.

The aim of this study was to compare the effect of two intervals of recovery (IR) in the unilateral knee extension on the volume completed in three series, the total volume of training and perceived exertion (RPE). Twelve young men, all with at least one year of experience in resistance training. The subjects performed 4 test sessions at intervals of 48 hours between them. In sessions 1 and 2 were tested and re-test of 10RM. In sections 3 and 4 had three sets of 10RM. The IR series were between 90 and 120s, counterbalanced between test days. Statistical analysis was ANOVA with repeated measures. The T-Student test for dependent variables was used to compare the sum of the total volume of training in two distinct ranges. Both 120 and 90s failed to maintain the volume along the three series, however, using the IR 120s could carry a greater volume of training. For RPE significant differences were found only in intrasequence IR90s in 3rd grade when compared with 1st and 2nd series of 90s and between sequences differences were found only with the 1st series of 120 compared with the 3rd set of 90s. The study indicated that the IR of 120 is higher than the 90s in the total volume of training, however, to keep volume between sets an IR system must be done. And the use of the RPE to identify intensity of effort appears to be a good method, since the IR 90s caused differences between the series, it did not happen when the IR of 120 was used.