Experimental study of speckle patterns generated by low-coherence semiconductor laser light.

Speckle is a wave interference phenomenon that has been studied in various fields, including optics, hydrodynamics, and acoustics. Speckle patterns contain spectral information of the interfering waves and of the scattering medium that generates the pattern. Here, we study experimentally the speckle patterns generated by the light emitted by two types of semiconductor lasers: conventional laser diodes, where we induce low-coherence emission by optical feedback or by pump current modulation, and coupled nanolasers. In both cases, we analyze the intensity statistics of the respective speckle patterns to inspect the degree of coherence of the light. We show that the speckle analysis provides a non-spectral way to assess the coherence of semiconductor laser light.

Experimental study of modulation waveforms for entraining the spikes emitted by a semiconductor laser with optical feedback.

The entrainment phenomenon, by which an oscillator adjusts its natural rhythm to an external periodic signal, has been observed in many natural systems. Recently, attention has focused on which are the optimal conditions for achieving entrainment. Here we use a semiconductor laser with optical feedback, operating in the low-frequency fluctuations (LFFs) regime, as a testbed for a controlled entrainment experiment. In the LFF regime the laser intensity displays abrupt spikes, which can be entrained to a weak periodic signal that directly modulates the laser pump current. We compare the performance of three modulation waveforms for producing 1:1 locking (one spike is emitted in each modulation cycle), as well as higher order locking regimes. We characterize the parameter regions where high-quality locking occurs, and those where the laser emits spikes which are not entrained to the external signal. The role of the modulation amplitude and frequency, and the role of the dc value of the laser pump current (that controls the natural spike frequency) in the entrainment quality are discussed.

Experimental characterization of the transition to coherence collapse in a semiconductor laser with optical feedback.

Semiconductor lasers with time-delayed optical feedback display a wide range of dynamical regimes, which have found various practical applications. They also provide excellent testbeds for data analysis tools for characterizing complex signals. Recently, several of us have analyzed experimental intensity time-traces and quantitatively identified the onset of different dynamical regimes, as the laser current increases. Specifically, we identified the onset of low-frequency fluctuations (LFFs), where the laser intensity displays abrupt dropouts, and the onset of coherence collapse (CC), where the intensity fluctuations are highly irregular. Here we map these regimes when both, the laser current and the feedback strength vary. We show that the shape of the distribution of intensity fluctuations (characterized by the standard deviation, the skewness, and the kurtosis) allows to distinguish among noise, LFFs and CC, and to quantitatively determine (in spite of the gradual nature of the transitions) the boundaries of the three regimes. Ordinal analysis of the inter-dropout time intervals consistently identifies the three regimes occurring in the same parameter regions as the analysis of the intensity distribution. Simulations of the well-known time-delayed Lang-Kobayashi model are in good qualitative agreement with the observations.

Detection of Zika virus RNA in semen of asymptomatic blood donors.

OBJECTIVES: Zika virus (ZIKV) transmission through semen donation has never been reported but the risk is supported by the detection of ZIKV in semen and the demonstration of ZIKV sexual transmission. The potential impact of ZIKV on assisted reproductive procedures should be evaluated. METHODS: We tested longitudinally collected semen samples provided by asymptomatic blood donors who tested positive for ZIKV RNA in plasma during ZIKV outbreaks in Puerto Rico and Florida in 2016. RESULTS: Five of the 14 (35.7%) asymptomatic blood donors provided semen samples that tested positive for ZIKV RNA, with ZIKV RNA loads ranging from 8.03 × 103 to 2.55 × 106 copies/mL. Plasma collected at the same time as the semen tested negative for ZIKV RNA for most ZIKV RNA-positive semen collections; all corresponding plasma samples tested positive or equivocal for anti-ZIKV IgG antibodies and all except one tested positive for ZIKV IgM antibodies. The rate of detection of ZIKV RNA in semen in asymptomatic donors is not significantly different from the rate previously reported for symptomatic patients. CONCLUSIONS: Our results that show a high percentage of detection of ZIKV RNA in the semen of asymptomatic men confirm that ZIKV is a new threat for reproductive medicine and should have important implications for assisted reproductive technology. We recommend that semen donations from men at risk for ZIKV infection should be tested for ZIKV RNA, regardless of symptoms of ZIKV infection.

Quantitative identification of dynamical transitions in a semiconductor laser with optical feedback.

Identifying transitions to complex dynamical regimes is a fundamental open problem with many practical applications. Semi- conductor lasers with optical feedback are excellent testbeds for studying such transitions, as they can generate a rich variety of output signals. Here we apply three analysis tools to quantify various aspects of the dynamical transitions that occur as the laser pump current increases. These tools allow to quantitatively detect the onset of two different regimes, low-frequency fluctuations and coherence collapse, and can be used for identifying the operating conditions that result in specific dynamical properties of the laser output. These tools can also be valuable for analyzing regime transitions in other complex systems.

p53 mutations cooperate with oncogenic Kras to promote adenocarcinoma from pancreatic ductal cells.

Pancreatic cancer is one of the most lethal malignancies, with virtually all patients eventually succumbing to their disease. Mutations in p53 have been documented in >50% of pancreatic cancers. Owing to the high incidence of p53 mutations in PanIN 3 lesions and pancreatic tumors, we interrogated the comparative ability of adult pancreatic acinar and ductal cells to respond to oncogenic Kras and mutant Tp53(R172H) using Hnf1b:CreER(T2) and Mist1:CreER(T2) mice. These studies involved co-activation of a membrane-tethered GFP lineage label, allowing for direct visualization and isolation of cells undergoing Kras and mutant p53 activation. Kras activation in Mist1(+) adult acinar cells resulted in brisk PanIN formation, whereas no evidence of pancreatic neoplasia was observed for up to 6 months following Kras activation in Hnf1beta(+) adult ductal cells. In contrast to the lack of response to oncogenic Kras alone, simultaneous activation of Kras and mutant p53 in adult ductal epithelium generated invasive PDAC in 75% of mice as early as 2.5 months after tamoxifen administration. These data demonstrate that pancreatic ductal cells, whereas exhibiting relative resistance to oncogenic Kras alone, can serve as an effective cell of origin for pancreatic ductal adenocarcinoma in the setting of gain-of-function mutations in p53.

Desarrollo de casos clínicos transversales: experiencia dinamizadora de la Unidad Docente de Toxicología de la Universidad de Barcelona / Development of transversal clinical cases: creating a dynamic experience for the Toxicology Teaching Unit of the Barcelona University

Se ha puesto en marcha un proyecto de innovación docente basado en el desarrollo de casos clínicos transversales a lo largo de las diferentes asignaturas del Grado de Farmacia. El objetivo es favorecer un aprendizaje integrador entre materias del grado, durante la carrera universitaria de los alumnos, mediante la elaboración de material docente adecuado para un uso transversal. También se propone desarrollar un "estilo" de comunicación entre profesores y un nuevo modelo de enseñanza en la universidad, que permita generar estrategias de coordinación del profesorado y de elaboración de materiales de uso común. La Unidad de Toxicología del Departamento de Salud Pública ha sido uno de los dinamizadores de este proyecto. Se ha escogido el alcohol como primer caso, introduciendo un personaje, Sam, un paciente de 20 años, que se inicia muy joven y del que veremos su evolución clínica. Sobre el guion básico del caso clínico, se han propuesto una serie de contenidosymaterialesespecíficosencadaunadelas asignaturas.El proyecto se inició en febrero de 2012, mediante una presentación a los alumnos de la asignatura de Bioquímica de primer curso, de los objetivos, la proyección de un documental, así como la distribución de un díptico informativo, y un posterior seminario. Los profesores consideramos muy satisfactoria y productiva esta experiencia. Creemos, que esta forma de trabajo en grupo colaborativo es una excelente herramienta para el aprendizaje de los alumnos y la formación del profesorado (AU)

A teaching innovation project based on the development of clinical cases across different subjects of Pharmacy Degree has been launched. The aim of this project is to promote integrative learning between the subjects, along the academic career, bydevelopingteachingmaterialssuitablefortransversaluse. Italso aims to develop a "style" of communication among teachers and a new model of teaching at the University by generating strategies for teachers' coordination and development of common teaching materials. The Toxicology Unit of the Department of Public Health has been one of the promoters of this project. Alcohol was chosen as first case by introducing a character, Sam, a patient of 20 years, who started very young in alcohol consumption and his clinical course will be seen along the different years. On the basic script of the case, a number of specific contents have been proposed to be covered in each subject. The project started in February 2012 with a presentation to the students of the first year degree, in the subject of Biochemistry, the objectives, a documentary film, the distribution of an informative leaflet and subsequent seminar. Teachers considered the experience as very satisfying and productive and trusted that the way of working in a collaborative group is an excellent tool for student's learning and teacher's training (AU)

Esencia de menta al 1, 6% como espasmolítico intestinalen la colangiopancreatografía retrógrada endoscópica / 1.6% Peppermint oil solution as intestinal spasmolytic in retrograde endoscopic cholangiopancreatography

Objetivos: La aparición de peristaltismo intestinal puede dificultar la realización de exploraciones o intervenciones mediante colangiopancreatografía retrógrada endoscópica(CPRE). Con el fin de disminuirlo es frecuente la utilización de espasmolíticos sistémicos, pese a los efectos adversos anticolinérgicos que presentan. Se propuso formular una preparación de esencia de menta al 1,6% de uso local para evitar estos efectos adversos. Método: Se formuló la preparación de la esencia de menta al 1,6% según la bibliografía encontrada. La efectividad de la fórmula fue valorada de manera semicualitativa según la disminución del peristaltismo. Resultados: Se ensayaron 2 emulgentes siendo polisorbato el más adecuado. El estudio piloto llevado a cabo en 8 pacientes demostró su efectividad y seguridad en la disminución del peristaltismo intestinal. Conclusiones: La esencia de menta al 1,6% constituye una alternativa efectiva y segura a la utilización de espasmolíticos sistémicos. Se requieren posteriores estudios incluyendo un mayor número de pacientes para establecer su utilidad en la práctica clínica habitual (AU)

Objectives: Intestinal peristalsis can impede explorations and interventions using retrograde endoscopic cholangiopancreatography. Systemic spasmolytics are frequently employed to reduce this phenomenon, in spite of the adverse anti-cholinergic effects they are associated with. We proposed a formula using 1.6% peppermint oil solution with local use in order to avoid these adverse side effects. Method: We formulated a preparation of 1.6% peppermint oil solution in accordance with the medical literature. The effectiveness of the formula was evaluated in a semi-qualitative manneraccording to the reduction in peristalsis. Results: We tested two different emulgents, and polysorbate provided the best results. The pilot study carried out with 8 patients demonstrated its effectiveness and safety in reducing intestinal peristalsis. Conclusions: 1.6% peppermint oil solution constitutes an effective and safe alternative to the use of systemic spasmolytics. More studies are needed with a larger sample size in order to establish its usefulness in normal clinical practice (AU)

Zero-lag synchronization and bubbling in delay-coupled lasers.

We show experimentally that two semiconductor lasers mutually coupled via a passive relay fiber loop exhibit chaos synchronization at zero lag, and study how this synchronized regime is lost as the lasers' pump currents are increased. We characterize the synchronization properties of the system with high temporal resolution in two different chaotic regimes, namely, low-frequency fluctuations and coherence collapse, identifying significant differences between them. In particular, a marked decrease in synchronization quality develops as the lasers enter the coherence collapse regime. Our high-resolution measurements allow us to establish that synchronization loss is associated with bubbling events, the frequency of which increases with increasing pump current.

Metabolic syndrome in Mediterranean women with polycystic ovary syndrome: when and how to predict its onset.

Polycystic ovary syndrome (PCOS) is associated with the metabolic syndrome (MetS). The metabolic disorders are not universal and may vary with race, age and phenotype. Our purpose was to determine the clinical and biochemical characteristics of Mediterranean PCOS women with MetS, compare them with non-MetS PCOS patients, and assess the ability of clinical data and biochemical tests to predict these abnormalities within our population. A total of 218 subjects, 196 PCOS women and 22 controls, undergo a physical examination and laboratory evaluation for a diagnosis of MetS. MetS was categorized according to NCEP ATP III guidelines. PCOS patients were analyzed separately and compared in three subgroups: three or more MetS criteria, two criteria, one or no criteria. The overall prevalence of MetS was 21.4%. Women with MetS had higher glucose (G) levels than PCOS women with two criteria (5.7 ± 1.5 vs 5 ± 0.4, p < 0.05). Both groups were comparable for all the other parameters. Waist circumference (WC), body mass index (BMI), systolic (SBP) and diastolic blood pressure (DBP), bioavailable testosterone (uT), triglycerides (TG) and insulin (I) levels were significantly higher and sex hormone-binding globulin (SHBG) levels, high-density lipoprotein (HDL), HOMA and QUICKI indexes significantly lower in both groups, MetS and patients with two criteria, compared with women with one or no criteria and the control group. WC, HDL and TG were the best predictors of PCOS patients at risk for MetS. In conclusion, we recommend considering PCOS patients with two criteria of MetS as having the same risk as patients with the full syndrome. Waist circumference with HDL and triglycerides is an efficient combined test to identify PCOS women at risk for metabolic and cardiovascular diseases.

[1.6% peppermint oil solution as intestinal spasmolytic in retrograde endoscopic cholangiopancreatography]. / Esencia de menta al 1,6% como espasmolítico intestinal en la colangiopancreatografía retrógrada endoscópica.

OBJECTIVES: Intestinal peristalsis can impede explorations and interventions using retrograde endoscopic cholangiopancreatography. Systemic spasmolytics are frequently employed to reduce this phenomenon, in spite of the adverse anti-cholinergic effects they are associated with. We proposed a formula using 1.6% peppermint oil solution with local use in order to avoid these adverse side effects. METHOD: We formulated a preparation of 1.6% peppermint oil solution in accordance with the medical literature. The effectiveness of the formula was evaluated in a semi-qualitative manner according to the reduction in peristalsis. RESULTS: We tested two different emulgents, and polysorbate provided the best results. The pilot study carried out with 8 patients demonstrated its effectiveness and safety in reducing intestinal peristalsis. CONCLUSIONS: 1.6% peppermint oil solution constitutes an effective and safe alternative to the use of systemic spasmolytics. More studies are needed with a larger sample size in order to establish its usefulness in normal clinical practice.

Dual-lag synchronization between coupled chaotic lasers due to path-delay interference.

We study experimentally the synchronization dynamics of two semiconductor lasers coupled unidirectionally via two different delayed paths. The emitter laser operates in a chaotic regime characterized by low-frequency fluctuations due to optical feedback and induces a synchronized dynamical activity in the receiver laser, which operates in the continuous-wave regime when uncoupled. Different delays in the two coupling paths lead to the coexistence of two time lags in the synchronized dynamics of the oscillators. This dual-lag synchronization degrades the average synchronization quality of the system of coupled lasers and hinders the transmission of information between them. Numerical simulation results agree with the experimental observations, and allow us to explore this phenomenon in a wide parameter range, and quantify the degree of signal transmission degradation caused by this chaotic path-delay interference.

Análisis tridimensional del movimiento de la columna lumbar en sujetos normales y pacientes con lumbalgia crónica / Tridimensional analysis of lumbar spinal mobility in normal subjects and low back pain patients

Introducción. La medición precisa de la movilidad lumbar permite una estimación de la severidad de las lumbalgias, monitorizar su evolución y valorar la efectividad del tratamiento. Se presentan los resultados obtenidos con el análisis computarizada del movimiento (análisis 3D) en sujetos con lumbalgia y un grupo de control para valorar las diferencias entre ambas poblaciones. Material y métodos. Se han estudiado 47 pacientes con lumbalgia crónica y 33 voluntarios sanos mediante análisis 3D del movimiento lumbar. Las mediciones se realizaron en una sesión única, estudiando los movimientos de flexión, extensión, y flexiones laterales derecha e izquierda, asimismo la velocidad de flexión. Para la determinación de la sensibilidad y especificidad se recurrió al análisis de las curvas (ROC). Resultados. El rango de movilidad fue mayor en los varones en todos los ejes del movimiento, aunque el análisis de la varianza permite ver que no existían diferencias significativas (p>0,05). Los valores medios de la población de control fueron considerablemente mayores en todas las variables, con diferencias altamente estadísticas (flexión p=0,0001; extensión p=0,05; flexión derecha p=0,0027; flexión izquierda p=0,0002; velocidad de flexión p=0,00001). Se presentan los valores de corte de cada variable, con indicación de su sensibilidad y especificidad. Discusión y conclusiones. En la población estudiada la movilidad lumbar valorada por análisis 3D del movimiento lumbar es similar en ambos sexos, aunque muestras mayores son necesarias para confirmar este dato. La conclusión principal del estudio es destacar la excelente capacidad de esta técnica de valoración funcional para discriminar a los pacientes con dolor lumbar crónico de la población normal. Aunque se trata de un hecho conocido, la abrumadora evidencia estadística y los valores normativos presentados muestran que la técnica constituye una excelente herramienta en el diagnóstico de la patología lumbar dolorosa crónica, destacando en este sentido la velocidad de flexión de la columna lumbar(AU)

Introduction. Accurate measurement of lumbar spine mobility can help to assess the severity of a low back pain, monitoring its course and evaluating treatment effectivity. The results obtained with the Inclinometer and 3D Movement Analysis (optoelectronic) in a group of patients and controls are presented to evaluate the differences with both techniques between both populations. Material and methods. A total of 47 subjects with chronic low back pain and 33 healthy controls were studied using both the Double Inclinometer technique and 3D Movement Analysis of the lumbar spine. Measurements were obtained in a single session of flexion, extension, right and left lateral flexions and flexion velocity. Results. Range of motion was greater in men than in women in all directions of movement, however, based on the analysis of the variance, the differences were not statistically significant (p>0.05). Mean values were significantly higher in all variables in healthy subjects (flexion p=0.0001; extension p=0.05; R lateral flexion p=0.0027; L lateral flexion, p=0.0002; flexion velocity p=0.00001). Cutoff values for each variable are shown, indicating their sensitivity and specificity. Discussion and conclusions. In the population studied by 3D Movement Analysis, lumbar mobility was similar en both genders, however, larger samples are needed to confirm these data. The main conclusion of the study is that this technique has excellent capacity to discriminate patients suffering chronic lumbar pain from the normal population. While restriction of motion is a well-known fact, the overwhelming statistical evidence and the normative data presented show that motion analysis is an excellent tool in the diagnosis of chronic low back pain, that is especially useful appears the velocity of flexion(AU)

Magnetoencephalographic pattern of epileptiform activity in children with early-onset autism spectrum disorders.

OBJECTIVE: To provide further data around magnetoencephalographic (MEG) findings in early-onset autism spectrum disorders (ASD). METHODS: Thirty-six children (mean age 7 years) diagnosed of PDD (DSM-IV, ICD-10) were studied. There were 22 children with autistic disorder, 9 with Asperger's syndrome, and 5 with pervasive developmental disorder not otherwise specified (PDD-NOS). According to the Childhood Autism Rating Scale (CARS), the autistic disorder was mild to moderate in 11, and severe in 11. Neuroimaging studies using three-dimensional MRI as well as simultaneous MEG-EEG and fusion techniques through magnetic source imaging (MSI) were performed, with the aid of anesthesia in non-cooperative patients. RESULTS: Most patients had no EEG abnormalities. All ASD children showed common specific abnormalities in the shape of low amplitude monophasic and biphasic spikes (isolated or short bursts) as well as acute waves, predominantly distributed in the perisylvian areas. In Asperger's syndrome, epileptiform spikes were mostly found in the right hemisphere. No lateralized epileptiform activity was observed in non-Asperger's autistic patients. CONCLUSIONS: MEG epileptiform activity is frequently documented in children with early-onset ASD. SIGNIFICANCE: Subclinical epileptiform activity is present especially in the perisylvian regions for many patients with ASD.

[Thalamic spectroscopy using magnetic resonance in autism]. / Espectroscopía talámica por resonancia magnética en el autismo.

OBJECTIVE: To evaluate the cerebral metabolic changes in paediatric patients using proton magnetic resonance spectroscopy. PATIENTS AND METHODS: We studied 31 patients diagnosed as having autism (autistic group) using cerebral magnetic resonance and hydrogen spectroscopy, together with 15 patients without autism (control group). The groups were sub divided according to age: 0-3 years, 4-7 years and 8-13 years. The morphology of the brain was studied using magnetic resonance and hydrogen spectroscopy of the thalamus. In each case we evaluated the presence of morphological changes in the brain and the concentrations of the cerebral metabolites N acetyl aspartate(NAA), choline (Cho) and creatinine (Cr) by measuring the coefficients NAA/Cr, NAA/Cho and Cho/Cr coefficients, and also any anomalous concentrations of other metabolites. RESULTS: No morphological changes were seen in the brains studied. There was no significant increase in minor metabolites in any of the groups studied. Significant differences in the NAA/Cho and NAA/Cr coefficients between the control and autistic groups were only seen in the oldest subgroup (8-13 years), but in the other groups the differences were not significant. The results in the sub group of older autistic children are similar to those of the younger subgroups in both autistic and control groups. CONCLUSION: The spectroscopic findings showed similar recordings in the control group and in the autistic group up to the age of 7 years with reduced thalamic NAA in autistic patients older than this. This suggests interruption and regression in the process of neuronal maturity, in which the thalamus also plays a part.

[Effect of cyclosporin and tacrolimus on lipoprotein oxidation after renal transplantation]. / Efecto de ciclosporina y tacrólimus sobre la oxidación de las lipoproteínas después del trasplante renal.

BACKGROUND: Cyclosporin A is a lipogenic immunosuppressor that can induce posttransplant hyperlipidaemia. Oxidation of low-density lipoprotein (LDL) has been recognized as a major atherogenic factor. Tacrolimus seems to be less lipogenic with an apparently better cardiovascular profile than CsA. METHODS: We have studied the lipidic profile and the oxidation of HDL and LDL in 20 renal transplant patients, 12 male and 8 female, mean age 45 +/- 10 year, who where switched from CsA to tacrolimus due to CsA adverse effects. LDL were determined by ultracentrifugation. Oxidation study before and 6 months after conversion to tacrolimus was performed by adding CuSO4. RESULTS: After conversion, systolic blood pressure (BP) decreased from 154 +/- 21 to 133 +/- 21 mm Hg (p = 0.008), diastolic BP from 97 +/- 13 to 77 +/- 15 mm Hg (p = 0.016), total cholesterol from 6.08 +/- 0.9 to 5.68 +/- 1.1 mmol/l (p = 0.02), LDL-chol from 3.29 +/- 1.01 to 2.96 +/- 0.3 mmol/l (p = 0.04) and apo-B lipoprotein from 1.42 +/- 0.28 to 1.15 +/- 0.34 mg/dl (p = 0.003). The oxidation of LDL improved after conversion: the initial dienic compounds decreased from 95 +/- 20 to 63 +/- 12 umol/g and the final DC from 207 +/- 56 to 107 +/- 35 umol/g. Lag-phase increased from 33 +/- 21 to 45 +/- 17 min (p < 0.05). CONCLUSION: Tacrolimus has improved hyperlipidaemia in our cyclosporin previously treated patients and increased the resistance to oxidation of high and low-density lipoproteins.

Practical protocols for stepwise solid-phase synthesis of cysteine-containing peptides.

This study details a series of conditions that may be applied to ensure 'safe' incorporation of cysteine with minimal racemization during automated or manual solid-phase peptide synthesis. Earlier studies from our laboratories [Han et al. (1997) J. Org. Chem. 62, 4307-4312] showed that several common coupling methods, including those exploiting in situ activating agents such as N-[(dimethylamino)-1H-1,2,3-triazolo[4,5-b]pyridin-1-ylmethylene]-N-methylmethanaminium hexafluorophosphate N-oxide (HATU), N-[1H-benzotriazol-1-yl)-(dimethylamino)methylene]-N-methylmethanaminium hexafluorophosphate N-oxide (HBTU), and (benzotriazol-1-yl-N-oxy)tris(dimethylamino)phosphonium hexafluorophosphate (BOP) [all in the presence of N-methylmorpholine (NMM) or N,N-diisopropylethylamine (DIEA) as a tertiary amine base], give rise to unacceptable levels (i.e. 5-33%) of cysteine racemization. As demonstrated on the tripeptide model H-Gly-Cys-Phe-NH(2), and on the nonapeptide dihydrooxytocin, the following methods are recommended: O-pentafluorophenyl (O-Pfp) ester in DMF; O-Pfp ester/1-hydroxybenzotriazole (HOBt) in DMF; N,N'-diisopropylcarbodiimide (DIPCDI)/HOBt in DMF; HBTU/HOBt/2,4,6-trimethylpyridine (TMP) in DMF (preactivation time 3.5-7.0 min in all of these cases); and HBTU/HOBt/TMP in CH(2)Cl(2)/DMF (1:1) with no preactivation. In fact, several of the aforementioned methods are now used routinely in our laboratory during the automated synthesis of analogs of the 58-residue protein bovine pancreatic trypsin inhibitor (BPTI). In addition, several highly hindered bases such as 2,6-dimethylpyridine (lutidine), 2,3,5,6-tetramethylpyridine (TEMP), octahydroacridine (OHA), and 2,6-di-tert-butyl-4-(dimethylamino)pyridine (DB[DMAP]) may be used in place of the usual DIEA or NMM to minimize cysteine racemization even with the in situ coupling protocols.

Efecto de ciclosporina y tacrólimus sobre la oxidación de las lipoproteínas después del trasplante renal / Effect of cyclosporin and tacrolimus on the oxidation of lipoproteins after kidney transplantation

La ciclosporina es un inmunosupresor capaz de inducir dislipemia después del trasplante renal. La oxidación de las lipoproteínas de baja densidad (LDL) constituye un factor aterogénico importante que puede estar presente en los trasplantados renales. Tacrólimus parece mostrar un perfil aparentemente menos aterogénico que la ciclosporina. Hemos estudiado el perfil lipídico y la oxidación de las LDL en 20 trasplantados renales, 12 hombres y 8 mujeres, con edad media de 45 ñ 10 años, que fueron convertidos de CsA a tacrolimus por diversos efectos adversos de CsA. Se estudió la oxidación de las LDL antes y seis meses después de la conversión, mediante adición de sulfato de cobre. Después de la conversión, la PA sistólica descendió de 154 ñ 21 a 133 ñ 21 mmHg (p = 0,008), la PA diastólica de 97 ñ 13 a 77 ñ 15 mmHg (p = 0,016), el colesterol total de 6,08 ñ 0,9 a 5,68 ñ 1,1 (p = 0,02), el col-LDL de 3,29 ñ 1,10 a 2,96 ñ 0,3 (p = 0,04) y las apolipoproteínas B de 1,42 ñ 0,28 a 1,15 ñ 0,34 (p = 0,003). La oxidación de las LDL mejoró, disminuyendo la generación de compuestos diénicos iniciales de 95 ñ 20 a 63 ñ 12 umol/g y los CD finales de 207 ñ 56 a 107 ñ 35 umol/g. La fase lag aumentó de 33 ñ 21 a 45 ñ 17 minutos (p < 0,05).En conclusión, Tacrólimus mejoró la dislipemia de nuestros pacientes trasplantados renales previamente inmunosuprimidos con ciclosporina, incrementando la resistencia a la oxidación de las lipoproteínas de baja densidad. (AU)