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1.
Org Biomol Chem ; 16(41): 7753-7759, 2018 11 07.
Artículo en Inglés | MEDLINE | ID: mdl-30299446

RESUMEN

Thioacetates as precursors of thiols are interesting starting points for synthesizing other organosulfur compounds. Herein, we propose a simple, efficient and fast method to obtain organic thioacetates using water as a solvent. Taking into account the great attention that has been paid toward environmentally friendly synthetic procedures in the past decades, we prove the role and the strength of the thioacetate anion as a nucleophile for nucleophilic displacement reactions in an aqueous medium. The reactions were carried out under pH control, to prevent the decomposition of the mesylate starting materials, using potassium carbonate as a safe and mild base. A simple work up allows products to be obtained with excellent yield and acceptable purity.

2.
Mult Scler ; 18(6): 835-42, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22127896

RESUMEN

BACKGROUND: Over recent years numerous patients with severe forms of multiple sclerosis (MS) refractory to conventional therapies have been treated with intense immunosuppression followed by autologous haematopoietic stem cell transplantation (AHSCT). The clinical outcome and the toxicity of AHSCT can be diverse, depending on the various types of conditioning protocols and on the disease phase. OBJECTIVES: To report the Italian experience on all the consecutive patients with MS treated with AHSCT with an intermediate intensity conditioning regimen, named BEAM/ATG, in the period from 1996 to 2008. METHODS: Clinical and magnetic resonance imaging outcomes of 74 patients were collected after a median follow-up period of 48.3 (range = 0.8-126) months. RESULTS: Two patients (2.7%) died from transplant-related causes. After 5 years, 66% of patients remained stable or improved. Among patients with a follow-up longer than 1 year, eight out of 25 subjects with a relapsing-remitting course (31%) had a 6-12 months confirmed Expanded Disability Status Scale improvement > 1 point after AHSCT as compared with one out of 36 (3%) patients with a secondary progressive disease course (p = 0.009). Among the 18 cases with a follow-up longer than 7 years, eight (44%) remained stable or had a sustained improvement while 10 (56%), after an initial period of stabilization or improvement with median duration of 3.5 years, showed a slow disability progression. CONCLUSIONS: This study shows that AHSCT with a BEAM/ATG conditioning regimen has a sustained effect in suppressing disease progression in aggressive MS cases unresponsive to conventional therapies. It can also cause a sustained clinical improvement, especially if treated subjects are still in the relapsing-remitting phase of the disease.


Asunto(s)
Trasplante de Células Madre Hematopoyéticas , Esclerosis Múltiple Crónica Progresiva/cirugía , Esclerosis Múltiple Recurrente-Remitente/cirugía , Acondicionamiento Pretrasplante/métodos , Adolescente , Adulto , Distribución de Chi-Cuadrado , Evaluación de la Discapacidad , Progresión de la Enfermedad , Supervivencia sin Enfermedad , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Trasplante de Células Madre Hematopoyéticas/mortalidad , Humanos , Italia , Estimación de Kaplan-Meier , Imagen por Resonancia Magnética , Persona de Mediana Edad , Esclerosis Múltiple Crónica Progresiva/diagnóstico , Esclerosis Múltiple Crónica Progresiva/mortalidad , Esclerosis Múltiple Recurrente-Remitente/diagnóstico , Esclerosis Múltiple Recurrente-Remitente/mortalidad , Valor Predictivo de las Pruebas , Sistema de Registros , Índice de Severidad de la Enfermedad , Factores de Tiempo , Acondicionamiento Pretrasplante/efectos adversos , Acondicionamiento Pretrasplante/mortalidad , Trasplante Autólogo , Resultado del Tratamiento , Adulto Joven
3.
Parkinsonism Relat Disord ; 12(5): 289-95, 2006 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-16554183

RESUMEN

A decline in verbal fluency is the most consistent neuropsychological sequela of deep brain stimulation (DBS) for Parkinson's disease. We assessed clinical correlates and switching and clustering subcomponents in 26 parkinsonians undergoing subthalamic DBS. Post-surgical motor improvement was accompanied by worsening at both letter and category fluency tasks. Total number of words and switches decreased, while average cluster size was unchanged. Worsening tended to be prominent in patients with baseline poorer cognitive status and more depressed mood. Impairment of shifting suggests prefrontal dysfunction, possibly due to disruption of fronto-striatal circuits along the surgical trajectory and/or to high frequency stimulation itself.


Asunto(s)
Cognición/fisiología , Estimulación Encefálica Profunda/efectos adversos , Enfermedad de Parkinson/complicaciones , Enfermedad de Parkinson/terapia , Trastornos del Habla/etiología , Subtálamo/fisiología , Conducta Verbal/fisiología , Anciano , Ganglios Basales/cirugía , Análisis por Conglomerados , Depresión/psicología , Electrodos Implantados , Femenino , Humanos , Masculino , Persona de Mediana Edad , Vías Nerviosas/fisiología , Examen Neurológico , Procedimientos Neuroquirúrgicos , Enfermedad de Parkinson/psicología , Trastornos del Habla/psicología
4.
Protein Pept Lett ; 12(4): 357-62, 2005 May.
Artículo en Inglés | MEDLINE | ID: mdl-15907181

RESUMEN

In this paper we describe a reductive amination procedure that can be employed in the preparation of a novel class of pseudopeptides in which a specific amide bond is replaced by a CH(Ar)NH group. The developed methodology, performed using NaBH(3)CN and TiCl(4), is characterized by the formation of diastereomeric intermediates in a relative 1:1 ratio. It provides aryl aminomethin pseudopeptides in moderate but satisfactory yields and with definite stereochemistry on the asymmetric centres next to the modified peptide bond.


Asunto(s)
Cetonas/química , Péptidos/química , Péptidos/síntesis química , Aminación , Bencilaminas/química , Borohidruros/química , Dipéptidos/síntesis química , Indicadores y Reactivos/química , Conformación Molecular , Titanio/química
5.
J Org Chem ; 70(10): 3892-7, 2005 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-15876076

RESUMEN

[reactions: see text] An efficient and general solution-phase method for the site-specific N-methylation of peptides has been developed. This novel procedure involves synthesis of N-nosyl protected peptides and their subsequent N-methylation with diazomethane. Its efficiency was proved by the successful synthesis of various hindered oligopeptides containing N-methyl amino acid residues with excellent yield and purity. The method is particularly attractive in that the adopted conditions do not cause any detectable racemization of the peptide stereocenters and the process does not require chromatographic purification of the methylated products. A further advantage is the compatibility of this methodology with Fmoc solution-phase peptide synthesis.


Asunto(s)
Péptidos/química , Diazometano/química , Metilación , Biosíntesis de Péptidos Independientes de Ácidos Nucleicos , Soluciones/química
6.
J Pept Res ; 63(4): 383-7, 2004 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-15102056

RESUMEN

A novel procedure for the deprotection of the carboxyl group of amino acid methyl esters is presented. The process is carried out by the reagent system aluminium trichloride/N,N-dimethylaniline that can successfully be applied to unblock the carboxyl moiety either of N-Fmoc-protected amino acid methyl esters and N-Fmoc-protected short dipeptide methyl esters. The chiralities of the optically pure amino acid or peptide precursors are maintained totally unchanged.


Asunto(s)
Compuestos de Aluminio/química , Aminoácidos/química , Compuestos de Anilina/química , Cloruros/química , Dipéptidos/química , Dipéptidos/síntesis química , Ésteres/química , Fluorenos/química , Cloruro de Aluminio , Estereoisomerismo
7.
Neurology ; 62(1): 41-5, 2004 Jan 13.
Artículo en Inglés | MEDLINE | ID: mdl-14718695

RESUMEN

OBJECTIVE: To evaluate the cognitive performance of patients with idiopathic REM sleep behavior disorder (RBD). METHODS: The authors studied 17 consecutive patients with idiopathic RBD vs 17 age- and education-matched control subjects. Tests given to each patient and control included Mini-Mental State Examination, verbal and spatial short-term memory, visual selective attention, verbal fluency, prose memory, visuoconstructional abilities, spatial learning, and executive function tests. A self-administered depression rating scale was also used. RESULTS: RBD patients had significantly lower scores than control subjects in two tests: copy of Rey-Osterrieth Figure and Corsi Supraspan Learning. No correlation was found between the results of neuropsychological tests and RBD duration or with polysomnographic findings. CONCLUSIONS: Visuospatial constructional dysfunction and altered visuospatial learning may be present in idiopathic RBD. A neuropsychological assessment may be indicated in RBD patients.


Asunto(s)
Trastornos del Conocimiento/diagnóstico , Pruebas Neuropsicológicas/estadística & datos numéricos , Trastorno de la Conducta del Sueño REM/diagnóstico , Anciano , Anciano de 80 o más Años , Trastornos del Conocimiento/complicaciones , Electroencefalografía , Electromiografía , Femenino , Humanos , Aprendizaje , Masculino , Persona de Mediana Edad , Polisomnografía , Trastorno de la Conducta del Sueño REM/complicaciones , Valores de Referencia , Percepción Espacial , Terminología como Asunto
8.
Brain Res Bull ; 61(1): 87-92, 2003 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-12788211

RESUMEN

The aims of this study were to assess cognitive function in obstructive sleep apnea (OSA) patients and to evaluate the effect of short- and long-term treatment with continuous positive airway pressure treatment (CPAP). A battery of neuropsychological tests, the Epworth Sleepiness Scale (ESS), and the Beck Inventory Scale were administered to 23 patients with severe OSA (age: 56.5+/-6.13; AHI: 54.9+/-13.37) and to 23 age- and education-matched controls. The OSA patients were evaluated in a baseline condition and in two follow-up treatment sessions (after 15 days and 4 months of CPAP, respectively). At baseline, OSA patients had a significant impairment, compared to controls, in tests of sustained attention, visuospatial learning, executive function, motor performance, and constructional abilities. The longitudinal evaluation showed that after a 15-days CPAP treatment attentive, visuospatial learning, and motor performances returned to normal levels. A 4-months CPAP treatment did not result in any further improvement in cognitive tests. Performance on tests evaluating executive functions and constructional abilities was not affected by short- and long-term treatment with CPAP. The findings of this study confirm the hypothesis of partial reversibility of cognitive dysfunction in OSA patients after CPAP.


Asunto(s)
Trastornos del Conocimiento/terapia , Respiración con Presión Positiva , Apnea Obstructiva del Sueño/terapia , Atención , Estudios de Casos y Controles , Trastornos del Conocimiento/etiología , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Desempeño Psicomotor , Índice de Severidad de la Enfermedad , Apnea Obstructiva del Sueño/complicaciones , Encuestas y Cuestionarios , Factores de Tiempo
9.
J Org Chem ; 66(21): 7002-7, 2001 Oct 19.
Artículo en Inglés | MEDLINE | ID: mdl-11597220

RESUMEN

In this article we describe a versatile and straightforward preparative approach to chiral aryl alpha-amino ketones via a Friedel-Crafts-type reaction of stable and enantiomerically pure N-Fmoc protected L-amino acid chlorides with toluene in the presence of aluminum trichloride. The developed methodology provided aryl alpha-amino-p-methylphenyl ketones, which can be obtained and isolated as free bases or recovered as their N-acetyl derivatives, after treatment with acetic anhydride in chloroform at room temperature, subsequent to the Lewis acid induced removal of the 9-fluorenylmethoxycarbonyl protecting group. The Friedel-Crafts-like process and the cleavage of the amino function masking group can selectively be performed since, as verified in all cases, the alpha-aminoacylation step occurred with kinetics that were faster than those required to remove the N-protection. The presented approach was also explored as a facile and useful synthetic tool for the preparation of optically pure ketone di- and tripeptides. These compounds can be obtained in exceptionally overall yields without need of chromatographic purification. Moreover, either aryl alpha-amino ketones or modified di- and tripeptides, in all cases, can be isolated in very high chemical and optical purity without recourse to resolution of diastereomeric mixtures, since the chiralities of the asymmetric amino acid educts were completely conserved throughout the entire process.


Asunto(s)
Cetonas/síntesis química , Péptidos/síntesis química , Dipéptidos/síntesis química , Cetonas/química , Péptidos/química , Estereoisomerismo
10.
Minerva Anestesiol ; 62(11): 357-61, 1996 Nov.
Artículo en Italiano | MEDLINE | ID: mdl-9102585

RESUMEN

METHODS: 50 ASA I-IV patients (62-90 aged, mean 78.54 +/- 6.48) were submitted to subarachnoidal selective anaesthesia with hyperbaric 1% bupivacaine and morphine for hip surgery. The aim of the study was to evaluate the clinical effectiveness of this anaesthetic technique. Ketamine 0.25 mg/kg and propofol 0.5 mg/kg were administered intravenously before positioning the patients homolaterally to the sick hip. The subarachnoidal puncture was effected at L2-L3 or L3-L4 level with a 22 gauge Quinke or Whitacre needle. The mean dose of bupivacaine was 7.72 +/- 0.81 mg and the mean dose of morphine was 0.23 +/- 0.03 mg. No patient needed general anaesthesia; 3 patients needed small boluses of ketamine and propofol or fentanyl (50 gamma) before the end of surgery. Ephedrine (5 mg) was administered to 5 patients to counteract hypotension by sympathetic block. Only one patient needed extra analgesia up to 8 hours after surgery (Ketorolac 60 mg). RESULTS: The morphine side effects were 3 cases of itch (6%), 4 cases of drowsiness (8%), 5 cases of nausea and vomiting (10%), 1 case of herpes labialis (2%); the subarachnoidal puncture caused one case of headache. CONCLUSIONS: The authors believe that such an easily executable anaesthetic technique is safe enough even in elderly patients.


Asunto(s)
Anestesia Raquidea/métodos , Fracturas de Cadera/cirugía , Anciano , Anciano de 80 o más Años , Efedrina , Femenino , Fentanilo , Humanos , Ketamina , Masculino , Persona de Mediana Edad , Medicación Preanestésica , Propofol , Espacio Subaracnoideo
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