Catheter-Related Right Atrial Endocarditis in a Dialysis Patient.

Hemodialysis catheters are frequently used for vascular access in end-stage chronic kidney disease patients lacking mature arteriovenous fistula. The incidence of infective endocarditis in hemodialysis patients is higher than in the general population and is associated with severe and potentially life-threatening complications. A high index of suspicion is imperative for early diagnosis and timely intervention to enhance the prognosis of this high-mortality condition. Imaging studies, like transthoracic and transesophageal echocardiography, are crucial for prompt diagnosis. We present a case of a 36-year-old woman undergoing hemodialysis, whose prolonged use of a permanent catheter led to the development of infective endocarditis complicated with septic pulmonary embolism. Our case report presents an example of right atrial endocarditis with a poor outcome due to delayed diagnosis.

The European Portuguese Version of the Composite Physical Function Scale: Cross-Cultural Adaptation and Validation in Community-Dwelling Older Adults.

This study aims to perform the cross-cultural adaptation to European Portuguese of the Composite Physical Function Scale and to assess its validity and reliability in a sample of community-dwelling older adults. The scale was translated into European Portuguese, back translated, and piloted in a sample of 16 representative individuals. Its validity and reliability were tested in an independent sample of 114 community-dwelling older adults (52 were tested twice to assess test-retest reliability). The results showed that the scale had good internal consistency (α = .90), construct validity (ρ = .71) and measurement error (78.8% agreement), and excellent test-retest reliability (κ = .98). However, a ceiling effect was found as 28% of the participants achieved the highest possible score. Although the scale has good measurement properties, the presence of ceiling effects is indicative that this tool is not able to distinguish higher levels of intrinsic capacity within community-dwelling older adults.

A Prospective, Dual-Center Trial of Circumferential Radiofrequency Ablation of Anal High-Grade Squamous Intraepithelial Lesions Demonstrate Improved Long-term Efficacy Over Historical Controls of Targeted Ablation.

BACKGROUND: Targeted ablation of anal canal high-grade dysplasia results in high recurrence over time. Circumferential radiofrequency ablation might decrease recurrence. OBJECTIVE: This study aimed to determine the safety and efficacy of circumferential radiofrequency ablation for anal high-grade dysplasia. DESIGN: This was a dual-center, prospective trial of circumferential radiofrequency ablation with a 1-year follow-up with longer follow-up data abstracted from medical records of study patients returning after trial for surveillance. Ten participants from the identically conducted pilot circumferential radiofrequency ablation trial were included to improve sample size for longer-term analysis. SETTINGS: This study included 3 surgeons at 2 sites. PATIENTS: The study included 51 patients undergoing circumferential radiofrequency ablation for anal canal high-grade dysplasia. INTERVENTION: Circumferential radiofrequency ablation of anal canal high-grade dysplasia and targeted radiofrequency ablation of recurrence. MAIN OUTCOME MEASURES: The primary outcome measures were circumferential radiofrequency ablation efficacy and associated morbidity. RESULTS: Fifty-one participants underwent circumferential radiofrequency ablation but 48 participants returned for 1 or more postprocedure high-resolution anoscopy and were evaluable. The mean age of participants was 43 years, most were male (94%), 33% were living with HIV, and 58% had 3 or more high-grade dysplasias treated. Sixty percent had no recurrence, whereas 19% had 1 recurrence, 15% had 2 recurrences, and 6% had 3 recurrences. Most recurrences (66%) developed within the first 6 months. Kaplan-Meier probability of recurrence combining both series was 19% at 3 months, 30% at 6 months, and approximately 40% after 6 months out to 30 months. Most common morbidities were pain (85.4%) lasting for a median of 21 (range, 4-91) days and bleeding (91%) lasting for a median of 21 (range, 5-87) days. Of those with pain and bleeding, 65% and 85%, respectively, described it as mild. No patients developed fistulas, stricture, or incontinence. No serious adverse events related to circumferential radiofrequency ablation occurred. Having a previous recurrence was the only significant predictor of a subsequent recurrence (HR, 28.53) for recurrence at 9 months or before. LIMITATIONS: Enrollment ended prematurely, 10 participants from the pilot study were combined to increase the sample size, and longer-term follow-up was collected retrospectively were the limitations of this study. CONCLUSIONS: Circumferential radiofrequency ablation has improved efficacy over targeted ablation but with increased pain and bleeding. See Video Abstract at http://links.lww.com/DCR/B973 . ESTUDIO PROSPECTIVO BICNTRICO SOBRE LA ABLACIN POR RADIOFRECUENCIA CIRCUNFERENCIAL DE LESIONES ANALES INTRAEPITELIALES ESCAMOSAS DE ALTO GRADO DEMOSTRANDO MAYOR EFICACIA A LARGO PLAZO CON RELACIN A CONTROLES HISTRICOS DE ABLACIN DIRIGIDA: ANTECEDENTES:La ablación dirigida de la displasia de alto grado en el canal anal proporciona como resultados una alta recidiva a largo plazo. La ablación por radiofrecuencia circunferencial podría disminuir la reincidencia.OBJETIVO:Determinar la seguridad y eficacia de la ablación por radiofrecuencia circunferencial para la displasia anal de alto grado.DISEÑO:Estudio prospectivo bicéntrico de ablación por radiofrecuencia circunferencial con un seguimiento de 1 año, en base al monitoreo prolongado de datos, obtenidos de los registros medicos, de todos los pacientes incluidos en el estudio y que fueron controlados clinicamente. Diez participantes del estudio piloto de ablación por radiofrecuencia circunferencial realizada de manera idéntica, se combinaron para mejorar el análisis del tamaño de la muestra a largo plazo.PACIENTES:Se incluyeron 51 pacientes sometidos a la ablación por radiofrecuencia circunferencial de una lesion displásica de alto grado en el canal anal.AJUSTES:Tres cirujanos en 2 centros.INTERVENCIÓN:Ablación por radiofrecuencia circunferencial de la displasia de alto grado en el canal anal y ablación por radiofrecuencia dirigida de la recidiva.PRINCIPALES MEDIDAS DE RESULTADOS:Las medidas primarias fueron la eficacia de la ablación por radiofrecuencia circunferencial y la morbilidad asociada.RESULTADOS:Cincuenta y un participantes se sometieron a la ablación por radiofrecuencia circunferencial, de los cuales, 48 regresaron para ser evaluados con ≥1 anuscopias de alta resolución, después del procedimiento. La edad media de los participantes fue de 43 años, en su mayoría hombres (94%), el 33% eran portadores de VIH y el 58% tenía ≥3 lesiones displásicas de alto grado tratadas. El sesenta por ciento no tuvo recidiva, mientras que el 19%, 15% y 6% tuvieron 1, 2 o 3 recidivas. La mayoría de las recaídas (66%) se desarrollaron dentro de los primeros 6 meses. La probabilidad de recurrencia de Kaplan-Meier combinando ambas series fue del 19 % a los 3 meses, del 30 % a los 6 meses y aproximadamente del 40 % entre los 6 y 30 meses. Los indicadores de morbilidad más frecuentes fueron, el dolor (85,4%) con una mediana de duración de 21 días (rango, 4-91) y sangrado (91%) con una mediana de duración de 21días (rango, 5-87). Aquellos pacientes con dolor (65%) y sangrado (85%) respectivamente, los describieron como leves. Ningún paciente desarrolló fístula, estenosis o incontinencia. No se produjeron eventos adversos graves relacionados con la ablación por radiofrecuencia circunferencial. Tener una recurrencia previa fue el único factor predictivo importante de una recidiva ulterior (RH 28,53) en casos de recaída a los 9 meses o antes.LIMITACIONES:Como el registro finalizó prematuramente, se agregaron 10 participantes del estudio piloto para aumentar el tamaño de la muestra. El seguimiento a largo plazo fué recopilado retrospectivamente.CONCLUSIONES:La ablación por radiofrecuencia circunferencial ha mejorado la eficacia sobre la ablación dirigida pero con dolor y sangrado mas importantes. Consulte Video Resumen en http://links.lww.com/DCR/B973 . ( Traducción-Dr. Xavier Delgadillo ).

Predictive Factors of Short-Term Related Musculoskeletal Pain in the Automotive Industry.

To determine the short-term associations between biomechanical risk factors and musculoskeletal symptoms in the upper limbs and low back in an automotive company, a longitudinal study with a follow-up of 4 days was conducted in a sample of 228 workers of the assembly and paint areas. Data were analyzed using generalized estimating equations, calculating the crude and adjusted model for age, sex, seniority, and intensity of pain at baseline. The interactions found were the same for both models. Workers were divided in low-risk and high-risk group for posture, force, exposure, percentage of cycle time with the arm at/above shoulder level, and with the trunk flexed or/and strongly flexed. The predictive factors showed by time × group effect were found between pain intensity on the left shoulder for posture (ß = 0.221, p < 0.001), percentage of time with the trunk flexed (ß = 0.136, p = 0.030) and overall exposure (ß = 0.140, p = 0.013). A time × group interactions were observed, namely between neck pain and posture (ß = 0.218, p = 0.005) and right wrist and force (ß = 0.107, p = 0.044). Workers in the high-risk group were more prone to report unfavorable effects on their self-reported musculoskeletal pain, across a workweek when exposed to specific risk factor, being posture important to neck, right wrist and left shoulder pain.

MDR-1 function protects oocyte mitochondria against the transgenerational effects of nitrogen mustard exposure.

Oocytes are vulnerable to alkylating agents like nitrogen mustard (NM), which can cause mitochondrial dysfunction associated with increased oxidative stress. Because mitochondria are maternally inherited, NM exposure affects oocyte mitochondrial physiology and compromises future progeny. Multidrug resistance transporters (MDRs) are transmembrane proteins that efflux such cytotoxic substances; MDR-1 is expressed in oocyte plasma and mitochondrial membranes and protects against oxidative stress. Our objective was to investigate how loss of MDR-1 can modulate oocyte response to NM transgenerationally. Wild Type (WT) and Mdr1a mutant female mice were injected intraperitoneally with sterile saline (control) or 0.1 mg/kg NM. 48 h post-injection, females were either sacrificed for F0 studies or mated with control males to yield F1 pups. After weaning, F1 females were sacrificed or mated to yield F2 pups. Germinal vesicle oocytes were assessed for mitochondrial membrane potential and reactive oxygen species (ROS) levels. NM exposed oocytes of both genotypes exhibited significantly higher ROS than controls in F0 and F1. NM F2 oocytes of neither genotype exhibited significantly higher ROS, though variation in Mdr1a mutants led to an upward trend. NM oocytes of both genotypes exhibited significantly disrupted mitochondrial membrane potential in F0. WT regained normalcy by F1 whereas Mdr1a mutants were unable to by F2. Our data suggest that Mdr1a mutants exhibit transgenerational mitochondrial dysfunction following toxic challenge that persists, implying that MDR-1 protects against toxicant-induced mitochondrial stress. Women without functional MDR-1 exposed to environmental toxicants could therefore be at risk for passing on compromised mitochondria to future offspring.

Responsiveness of the Calf-Raise Senior test in community-dwelling older adults undergoing an exercise intervention program.

INTRODUCTION: Mobility significantly depends on the ankle muscles' strength which is particularly relevant for the performance of daily activities. Few tools are available, to assess ankle strength with all of the measurement properties tested. The purpose of this study is to test the responsiveness of Calf-Raise Senior Test (CRS) in a sample of elderly participants undergoing a 24-week community exercise program. METHODS: 82 older adults participated in an exercise program and were assessed with CRS Test and 30-second chair stand test (CS) at baseline and at follow-up. Effect size (ES), standardized response mean (SRM) and minimal detectable change (MDC) measures were calculated for the CRS and CS tests scores. ROC curves analysis was used to define a cut-off representing the minimally important difference of Calf-Raise Senior test. RESULTS: Results revealed a small (ES = 0.42) to moderate (SRM = 0.51) responsiveness in plantar-flexion strength and power across time, which was lower than that of CS test (ES = 0.64, SRM = 0.67). The responsiveness of CRS test was more evident in groups of subjects with lower initial scores. A minimal important difference (MID) of 3.5 repetitions and a minimal detectable change (MDC) of 4.6 was found for the CRS. CONCLUSION: Calf-Raise Senior Test is a useful field test to assess elderly ankle function, with moderate responsiveness properties. The cutoff scores of MDC and MID presented in this study can be useful in determining the success of interventions aiming at improving mobility in senior participants.

Joint moments' contributions to vertically accelerate the center of mass during stair ambulation in the elderly: An induced acceleration approach.

Falls are a serious problem faced by the elderly. Older adults report mostly to fall while performing locomotor activities, especially the ones requiring stair negotiation. During these tasks, older adults, when compared with young adults, seem to redistribute their lower limb joint moments. This may indicate that older adults use a different strategy to accelerate the body upward during these tasks. The purposes of this study were to quantify the contributions of each lower limb joint moment to vertically accelerate the center of mass during stair ascent and descent, in a sample of community-dwelling older adults, and to verify if those contributions were correlated with age and functional fitness level. A joint moment induced acceleration analysis was performed in 29 older adults while ascending and descending stairs at their preferred speed. Agreeing with previous studies, during both tasks, the ankle plantarflexor and the knee extensor joint moments were the main contributors to support the body. Although having a smaller contribution to vertically accelerate the body, during stair descent, the hip joint moment contribution was related with the balance score. Further, older adults, when compared with the results reported previously for young adults, seem to use more their knee extensor moment than the ankle plantarflexor moment to support the body when the COM downward velocity is increasing. By contributing for a better understanding of stair negotiation in community dwelling older adults, this study may help to support the design of interventions aiming at fall prevention and/or mobility enhancement within this population.

Effect of 6-month community-based exercise interventions on gait and functional fitness of an older population: a quasi-experimental study.

BACKGROUND: Gait ability in older adults has been associated with independent living, increased survival rates, fall prevention, and quality of life. There are inconsistent findings regarding the effects of exercise interventions in the maintenance of gait parameters. OBJECTIVES: The aim of the study was to analyze the effects of a community-based periodized exercise intervention on the improvement of gait parameters and functional fitness in an older adult group compared with a non-periodized program. METHODS: A quasi-experimental study with follow-up was performed in a periodized exercise group (N=15) and in a non-periodized exercise group (N=13). The primary outcomes were plantar pressure gait parameters, and the secondary outcomes were physical activity, aerobic endurance, lower limb strength, agility, and balance. These variables were recorded at baseline and after 6 months of intervention. RESULTS: Both programs were tailored to older adults' functional fitness level and proved to be effective in reducing the age-related decline regarding functional fitness and gait parameters. Gait parameters were sensitive to both the exercise interventions. CONCLUSION: These exercise protocols can be used by exercise professionals in prescribing community exercise programs, as well as by health professionals in promoting active aging.

Baccharis reticularia DC. and Limonene Nanoemulsions: Promising Larvicidal Agents for Aedes aegypti (Diptera: Culicidae) Control.

Baccharis reticularia DC. is a plant species from the Asteraceae family that is endemic to Brazil. Despite the great importance of Baccharis genus, no study has been carried out regarding either the phytochemical composition of B. reticularia or the evaluation of its larvicidal potential. Considering the intrinsic immiscibility of essential oils, this study shows larvicidal nanoemulsions containing the B. reticularia phytochemically characterized essential oil and its main constituent against Aedes aegypti. The major compound found was d-limonene (25.7%). The essential oil inhibited the acetylcholinesterase, one of the main targets of insecticides. The required hydrophile-lipophile balance of both nanoemulsions was 15.0. The mean droplet sizes were around 90.0 nm, and no major alterations were observed after 24 h of preparation for both formulations. After 48 h of treatment, the estimated LC50 values were 118.94 µg mL-1 and 81.19 µg mL-1 for B. reticularia essential oil and d-limonene nanoemulsions, respectively. Morphological alterations evidenced by scanning electron micrography were observed on the larvae treated with the d-limonene nanoemulsion. This paper demonstrated a simple and ecofriendly method for obtaining B. reticularia essential oil and d-limonene aqueous nanoemulsions by a non-heating and solvent-free method, as promising alternatives for Aedes aegypti control.

Community-Based Exercise Intervention for Gait and Functional Fitness Improvement in an Older Population: Study Protocol.

Functional fitness (FF) and gait ability in older populations have been associated with increased survival rates, fall prevention, and quality of life. One possible intervention for the improvement of FF is well-structured exercise programs. However, there are inconsistent findings regarding the effects of exercise interventions in the maintenance of gait parameters. The aim of this protocol is to develop a community-based exercise intervention targeting an older population. The intervention aim is the improvement of gait parameters and FF. A control trial with follow-up will be performed. The primary outcome variables will be plantar pressure gait parameters. The secondary outcome variables will be aerobic endurance, lower limb strength, agility, and balance. These variables will be recorded at baseline and after 12, 24, and 36 weeks, in the intervention and control groups. If effective, this protocol can be used by exercise professionals in improving community exercise programs.

Inter-session agreement and reliability of the Global Gait Asymmetry index in healthy adults.

There has been a growing effort in restoring gait symmetry in clinical conditions associated with pronounced gait asymmetry. A prerequisite to achieve this is that the chosen approach can accurately assess symmetry and detect/impose changes that exceed the natural day to day variability. Global symmetry indices are superior to local and discrete indices because they capture the patient's overall gait symmetry. However, their repeatability is unknown. This study assessed the inter-session agreement and reliability of the Global Gait Asymmetry index. Twenty-three healthy individuals participated in two 3D gait analyses, performed approximately one week apart. The 95% limits of agreement, standard error of measurement, smallest detectable change, and intraclass correlation coefficient were analysed. The obtained values showed this index has poor agreement and reliability between sessions. Therefore, it cannot be used to assess the patient's progress overtime nor to compare symmetry levels among groups.

Contributo do programa de estimulação na atenção - PEA - para alterações atencionais em alunos com TDAH / Contribution of the stimulation program in the attention - PEA - for attentional changes in students with ADHD

As alterações na capacidade atencional em alunos em idade escolar transformam-se num problema na vida académica e pessoal. Este estudo centra-se na aplicação de um Programa de Estimulação na Atenção - PEA - em alunos com TDAH. Antes da aplicação do programa aferiu-se a capacidade atencional dos participantes, bem como no final das 12 sessões previstas na intervenção com o mesmo. O objetivo foi o de obter evidências de sucesso no aumento dos níveis de atenção numa amostra brasileira. Participaram 50 estudantes, ambos os sexos, idade entre 8 e 12 anos, cursando a fase do fundamental I e II. Foram utilizados os instrumentos: Programa de Estimulação da Atenção-PEA; Questionário do Professor; Questionário do Aluno e o Mapa da Atenção. Os dados indicaram que o programa produziu incremento da atenção em todas as dimensões analisadas. O PEA constitui um instrumento que reuniu, na generalidade, resultados de evidência de sucesso, os quais permitem a administração e utilização para finalidades de intervenção nas funções da atenção em alunos com TDAH

Changes in attentional ability in school-age students become a problem in academic and personal life. This study focuses on the application of a Program of Attention Stimulation - PEA - in students with ADHD. Before the application of the program, participants attentional capacity was assessed as well as at the end of the 12 sessions scheduled for intervention with the participants. The objective was to obtain evidences of success in increasing attention levels in a Brazilian sample. Fifty students, both sexes, aged between 8 and 12 years, participated in the Fundamental I e II. The following instruments were used: Program of Stimulation of Attention-PEA; Teacher's Questionnaire; Student Questionnaire and Attention Map. The results indicated that the program produced increased attention in all dimensions analyzed. The PEA is an instrument that has generally gathered evidence of success that allows administration and use for intervention purposes in the attention functions in students with ADHD.

Three dimensional multi-segmental trunk kinematics and kinetics during gait: Test-retest reliability and minimal detectable change.

BACKGROUND AND AIM: Trunk kinematics and kinetics can contribute to more detailed information on gait impairment, however, data about reliability and measurement error of multi-segment trunk on three-dimensional gait analysis (3DGA) is lacking. The aim of this study is to investigate test-retest reliability and MDC of 3DGA kinematic and kinetic data in a sample of healthy individuals, using a two rigid segment model for the trunk. METHODS: A test-retest study with a median interval of 7 days and a sample of 23 healthy individuals was conducted. Anthropometric, time-distance parameters and peak values for lower limb and trunk joint angles/moments were computed. The intraclass correlation coefficient (ICC3,k), standard error of measurement (SEM), minimal detectable change (MDC) and 95% limits of agreement (LOA) were calculated. RESULTS: We found acceptable test-retest reliability for most joint angles and a SEM ≤4°. The ICCs were above 0.7 for joint moments and the SEM and MDC were ≤0.2Nm/kg and ≤0.6Nm/kg, respectively. Bland-Altman plots with 95% LOA revealed a good agreement and time-distance parameters were all highly repeatable (majority ICCs>0.90). CONCLUSIONS: The results of this study suggest varied reliability indices for multi-segment trunk joint angles and moments during gait and an acceptable level of error, particularly for sagittal plane parameters. Some parameters showed wide 95% CIs for ICCs and higher SEM%. However, we believe that this study provides preliminary data regarding reliability indices for multi-segment trunk during gait, which may be valuable for clinical reasoning and decision making when dealing with movement disorders.

Test-retest reliability and minimal detectable change of three-dimensional gait analysis in chronic low back pain patients.

BACKGROUND AND AIM: Three-dimensional gait analysis (3DGA) can provide detailed data on gait impairment in chronic low back pain (CLBP) patients. However, data about reliability and measurement error of 3DGA in this population is lacking. The aim of this study is to investigate test-retest reliability and minimal detectable change of 3DGA in a sample of CLBP patients. METHODS: A test-retest study was conducted with a sample of 14 CLBP patients that underwent two biomechanical gait assessments with an interval of 7.6 ± 1.8 days. Anthropometric and time-distance parameters, as well as peak values for lower limb and trunk joint angles and moments, were computed. Intraclass Correlation Coefficient (ICC3,k) and their 95% confidence intervals were calculated. Standard error of measurement (SEM), minimal detectable change (MDC) and limits of agreement (LOA) were also estimated. RESULTS: The obtained ICC values demonstrate high test-retest reliability for most joint angles, with low SEM (< 2.5°) values. Although joint moments showed lower reliability than joint angles, the majority of the ICCs were above 0.7 and the SEM and MDC values were low (≤ 0.06 Nm/kg and ≤ 0.18 Nm/kg). Bland-Altman plots with 95% LOA revealed a good agreement and time-distance parameters were all highly repeatable (ICCs > 0.86). CONCLUSIONS: The results of this study show high test-retest reliability for lower limb and trunk joint angles, and time-distance parameters during gait in CLBP individuals, together with a low measurement error. These results also support the use of this method in clinical assessments of CLBP patients' gait patterns.

Synergistic interaction between ankle and knee during hopping revealed through induced acceleration analysis.

The forces produced by the muscles can deliver energy to a target segment they are not attached to, by transferring this energy throughout the other segments in the chain. This is a synergistic way of functioning, which allows muscles to accelerate or decelerate segments in order to reach the target one. The purpose of this study was to characterize the contribution of each lower extremity joint to the vertical acceleration of the body's center of mass during a hopping exercise. To accomplish this, an induced acceleration analysis was performed using a model with eight segments. The results indicate that the strategies produced during a hopping exercise rely on the synergy between the knee and ankle joints, with most of the vertical acceleration being produced by the knee extensors, while the ankle plantar flexors act as stabilizers of the foot. This synergy between the ankle and the knee is perhaps a mechanism that allows the transfer of power from the knee muscles to the ground, and we believe that in this particular task the net action of the foot and ankle moments is to produce a stable foot with little overall acceleration.

Sensitivity of joint kinematics and kinetics to different pose estimation algorithms and joint constraints in the elderly.

The purpose of this research was to study the sensitivity of lower limb joint kinematics and kinetics, calculated during different functional tasks (walking, stair descent and stair ascent) in a sample of older adults, to different pose estimation algorithms and models' joint constraints. Three models were developed and optimized differently: in one model, each segment had 6 degrees of freedom (segment optimization, SO), while in the other two, global optimization (GO) was used, with different joint constraints: (1) GO, allowing all joint rotations; (2) GOR, allowing three rotations at the hip, one at the knee (flexion/extension) and two at the ankle (dorsi/plantar flexion and eversion/inversion). The results showed that joint angles are more sensitive to the model's constraints than joint moments and, the more restrictive the model, the higher the differences between models, especially for the frontal and transverse planes (max. RMS difference during gait: 11.7 degrees (64%) vs 0.12 N·m/kg (35.4%). In addition, except for knee abduction/adduction angle, differences between SO and GO models were relatively low. Since GO avoids the nonanatomical dislocations sometimes observed in SO, choosing this model seems to be reasonable for future studies with a similar sample and study design.

A versatile and efficient approach for the synthesis of chiral 1,3-nitroamines and 1,3-diamines via conjugate addition to new (S,E)-γ-aminated nitroalkenes derived from L-α-amino acids.

New chiral (S,E)-γ-N,N-dibenzylated nitroalkenes 2a-c were synthesized from natural L-(α)-amino acids in five steps with overall yields of 68-88%. The conjugate addition of hydride, methoxide, nitronate and azide nucleophiles to 2a-c led to the corresponding chiral 1,3-nitroamines in 74-90% yield. The conjugate addition of cyanide anion to 2a,b was followed by HNO2 elimination affording chiral aminated acrylonitriles (73-98%). On the other hand, the azide anion reacted with 2a, in acetonitrile, via a [3 + 2]-cycloaddition in which HNO2 was lost, providing the corresponding 1,2,3-triazole derivative. Direct reduction of 1,3-nitroamine derivatives 9a,b produced the corresponding 1,3-diamines in good yields.