Programas de optimización del uso de antimicrobianos en los servicios de urgencias españoles: Estudio PROA-URG / Antibiotic stewardship programs in the Spanish emergency services: PROA-URG Study

Introducción: Los programas de optimización de antimicrobianos (PROA) son herramientas clave en la adecuación de estos fármacos. La información disponible sobre la aplicación e indicadores para monitorizar estos programas en urgencias es limitada. El objetivo del estudio es conocer el grado de implantación de programas PROA en los servicios de urgencias, así como el uso de antimicrobianos en estas unidades. Material y métodos. Estudio multicéntrico retrospectivo. Se envió una invitación a todos los participantes del grupo de trabajo de farmacéuticos de urgencias REDFASTER-SEFH. Se utilizó un cuestionario de 21 ítems, contestado por un equipo formado por especialistas en los servicios de farmacia hospitalaria, urgencias, enfermedades infecciosas y microbiología. Resultados. 18 hospitales completaron la encuesta. Catorce (77,8%) disponían de un responsable PROA en la unidad. El valor de DDD por 1000 ingresos osciló entre 36,5 y 400,5 (mediana 100,4 [RIQ:57,2-157,3]). El grupo de carbapenémicos y macrólidos presentó una amplia variabilidad. Únicamente seis (33,3%) hospitales disponían de informe anual de resistencias específico para urocultivos y hemocultivos en urgencias. El porcentaje de multirresistentes en urocultivos fue del 12,5% y en hemocultivos del 12,2%. El porcentaje de adecuación en bacteremia de acuerdo con el resultado del hemocultivo fue del 81,0% (RIQ:74,6-85,0%), y en infección urinaria del 78,0% (RIQ:71,5-88,0%). Conclusiones. Pese a la existencia de responsables PROA, actividades formativas y guías de tratamiento en urgencias, la información sobre el uso de antimicrobianos y el perfil de resistencias en estas unidades es limitado. Futuras actividades han de ir encaminadas a mejorar la información sobre los resultados PROA propios para estas unidades. (AU)

Introduction: Antimicrobial stewardship programs (ASP) have become a key tool in the adaptation of these drugs to the health system. The information available on the application and indicators used in these programs in emergency departments is scarce. The objective of this study is to know theextent of ASP implementation in the emergency departments, as well as the use of antimicrobials in these units. Material and methods. Multicenter retrospective study. An invitation was sent to all participants of the REDFASTER-SEFH emergency pharmacist working group. A questionnaire was used consisting of 21 items, answered by a team made up of a pharmacist, emergency room specialist, infectious disease specialist and microbiologist. Results. Eighteen hospitals completed the survey. Fourteen (77.8%) had an ASP manager. The DDD value per 1000 admissions ranged between 36.5 and 400.5 (median: 100.4 [IQR:57.2-157.3]). Both carbapenem and macrolide group presented wide variability in use. Six (33.3%) hospitals had an annual report on the specific resistance profile for urine and blood cultures. The percentage of multi-drug resistant strains in urine cultures was 12.5% and in blood cultures 12.2%. The percentage of adequacy in the bacteremia treatment was 81.0% (IQR:74.6-85.0%), while in urinary tract infections was 78.0% (IQR:71.5-88.0). Conclusions: Despite the existence of ASP members in emergency services, as well as the training activity and local guidelines is common. knowledge of the use of antimicrobials and resistances is limited. Future activities must be aimed at improving information about the ASP results in these units. (AU)

Regio- and Stereoselectivity of the Norrish-Yang Photocyclization of Dialkyl 1,2-Diketones: Solution versus Solid State Photochemistry of Two Polymorphs.

As shown by X-ray crystallography, crystals of 3ß-acetoxy-16,17-seco-17,20-dioxopregn-5-ene-16-nitrile are dimorphic. The regioselectivity of the Norrish-Yang type II photocyclization under visible light of this steroidal 1,2-diketone, which bears primary, secondary, and tertiary nonequivalent abstractable γ-hydrogens, dramatically increases in the crystalline state of both polymorphs. X-ray crystallography and molecular mechanics calculations reveal crystal structure-solid state photochemistry relationships.

1,5-Hydrogen Atom Transfer/Surzur-Tanner Rearrangement: A Radical Cascade Approach for the Synthesis of 1,6-Dioxaspiro[4.5]decane and 6,8-Dioxabicyclo[3.2.1]octane Scaffolds in Carbohydrate Systems.

The 1,5-HAT-1,2-(ester)alkyl radical migration (Surzur-Tanner rearrangement) radical/polar sequence triggered by alkoxyl radicals has been studied on a series of C-glycosyl substrates with 3-C-(α,ß-d,l-glycopyranosyl)1-propanol and C-(α-d,l-glycopyranosyl)methanol structures prepared from chiral pool d- and l-sugar. The use of acetoxy and diphenoxyphosphatoxy as leaving groups provides an efficient construction of 10-deoxy-1,6-dioxaspiro[4.5]decane and 4-deoxy-6,8-dioxabicyclo[3.2.1]octane frameworks. The alkoxyl radicals were generated by the reaction of the corresponding N-alkoxyphthalimides with group 14 hydrides [n-Bu3SnH(D) and (TMS)3SiH], and in comparative terms, the reaction was also initiated by visible light photocatalysis using the Hantzsch ester/fac-Ir(ppy)3 procedure. Special attention was devoted to the influence of the relative stereochemistry of the centers involved in the radical sequence on the reaction outcome. The addition of BF3•Et2O as a catalyst to the radical sequence resulted in a significant increase in the yields of the desired bicyclic ketals.

Safety and effectiveness of a four-factor prothrombin complex concentrate for vitamin K antagonist reversal following a fixed-dose strategy.

OBJECTIVES: Early reversal of anticoagulation improves outcomes in major bleeding and emergency surgery. To reverse vitamin K antagonists (VKA), vitamin K in addition to prothrombin complex concentrate (PCC) is recommended. Dosing recommendations for VKA reversal provided by the manufacturer are 25-50 IU/kg depending on the baseline international normalised ratio (INR). Nevertheless, we recommend an initial fixed dose of 1000 IU, and additional 500 IU doses evaluated on a case-by-case basis. As there is a paucity of clinical data demonstrating the efficacy and safety of this strategy, we designed this study to assess the effectiveness and safety of a four-factor (4F)-PCC for VKA reversal following a fixed-dose strategy. METHODS: This was a retrospective study of adult patients who received 4F-PCC for VKA reversal. The primary outcome was INR correction. INR correction was achieved if the first INR draw after 4F-PCC was ≤1.5. Safety outcome was any confirmed thromboembolic event within 3 months after 4F-PCC. Secondary outcomes included activated partial thromboplastin time (aPTT) correction, as well as haemostatic effectiveness for bleeding patients. RESULTS: A total of 145 patients were included: 106 (73.1%) in the bleeding group and 39 (26.9%) in the emergency surgery group. The INR target was reached in 102 (70.3%) patients (p<0.0001). In one case, a thromboembolic complication was possibly related to 4F-PCC. The aPTT ratio target was reached in 113 (77.9%) patients (p<0.0001), and 79 of the 106 (74.5%) patients reversed for bleeding achieved haemostatic effectiveness. CONCLUSIONS: After 4F-PCC, the majority of patients achieved the target INR, meaning 4F-PCC is a useful modality for rapid INR reduction. The safety profile may be considered acceptable. Fixed-dose 4F-PCC was able to restore haemostasis rapidly while minimising the risk of adverse events and optimising available resources.

Hospital pharmacist experience in a multidisciplinary team in special care settings.

The COVID-19 pandemic is placing huge strain on health systems and professionals. Emergency departments and their pharmacy services have been the first to face this challenge before any other pharmacy units. This article provides a description of the experience of two public hospitals  located in the Autonomous Community of Madrid, Spain. Team working and  reciprocal trust have made it possible to meet the unprecedented demand for  health services and has facilitated rapid decision making. Strategies have been  developed to guarantee the availability, distribution and safe use of medications. Other strategies have included favoring communication within Emergency  Departments pharmacy services, and between these services and Emergency  Departments during the pandemic. Multidisciplinary cooperation and information  sharing have traditionally formed the base for efficient and quality work, along  with solid technologies that guarantee a safe use of medications. The crucial role of information and communication technologies during the pandemic may give  rise to a new model of pharmaceutical care, which should not replace face-to- face Emergency Department pharmacist support and advice. Promoting the re- humanization of healthcare and pharmacy services is essential. An adequate  technical training and the development of abilities such as flexibility, planning  and coordination skills, and an assertive communication and management of  emotions will be key to the successful management of unimaginable settings in  the future.

La actual pandemia ha puesto al límite la capacidad de respuesta del sistema  sanitario y a sus profesionales. Los primeros en enfrentarse a este reto han sido  los servicios de urgencias y, con ellos, los farmacéuticos ligados a estas  unidades, que han precedido a los del resto de áreas del servicio de farmacia. En este artículo se narra la experiencia en dos hospitales públicos de la Comunidad  de Madrid. El trabajo en equipo y la confianza mutua han permitido abordar una demanda asistencial desorbitada y una rápida toma de decisiones. Se han  desarrollado estrategias para garantizar la disponibilidad y la dispensación de  medicamentos, y favorecer la mejora en la seguridad de su utilización. Fomentar la comunicación dentro del propio servicio y con urgencias ha sido otra de las  estrategias imprescindibles potenciadas durante la pandemia. La cooperación  multidisciplinar y la coordinación de la información siempre serán la base de un  trabajo eficiente y de calidad, junto con sistemas informáticos bien desarrollados como pieza clave en la seguridad del proceso de utilización de medicamentos. El  impulso de las tecnologías para la información y la comunicación durante la  pandemia quizá permita un nuevo modelo de atención farmacéutica que no  debería sustituir la actividad presencial del farmacéutico en urgencias; es  imprescindible retomar e impulsar la humanización desde los diferentes  estamentos. Una buena formación técnica y el desarrollo de habilidades como  flexibilidad, capacidad de organización y coordinación, comunicación y gestión de las emociones serán imprescindibles para afrontar futuras e inimaginables situaciones.

Synthetic Approaches to Phosphasugars (2-oxo-1,2-oxaphosphacyclanes) Using the Anomeric Alkoxyl Radical ß-Fragmentation Reaction as the Key Step.

The anomeric alkoxyl radical ß-fragmentation (ARF) of carbohydrates possessing an electron-withdrawing group (EWG) at C2, promoted by PhI(OAc)2/I2, gives rise to an acyclic iodide through which a pentavalent atom of phosphorus can be introduced via the Arbuzov reaction. After selective hydrolysis and subsequent cyclization, the phosphonate or phosphinate intermediates can be converted into 2-deoxy-1-phosphahexopyranose and 2-deoxy-1-phosphapentopyranose sugars. The ARF of carbohydrates with an electron-donor group (EDG) at C2 proceeds by a radical-polar crossover mechanism, and the cyclization occurs by nucleophilic attack of a conveniently positioned phosphonate or phosphinate group to the transient oxocarbenium ion. This alternative methodology leads to 5-phosphasugars with a 4-deoxy-5-phosphapentopyranose framework. The structure and conformation of the 2-oxo-1,2-oxaphosphinane and 2-oxo-1,2-oxaphospholane ring systems in different carbohydrate models have been studied by NMR and X-ray crystallography.

Experiencias del farmacéutico de hospital en el equipo pluridisciplinar en unidades especiales / Hospital pharmacist experience in a multidisciplinary team in special care settings

La actual pandemia ha puesto al límite la capacidad de respuesta del sistema sanitario y a sus profesionales. Los primeros en enfrentarse a este reto han sido los servicios de urgencias y, con ellos, los farmacéuticos ligados a estas unidades, que han precedido a los del resto de áreas del servicio de farmacia. En este artículo se narra la experiencia en dos hospitales públicos de la Comunidad de Madrid. El trabajo en equipo y la confianza mutua han permitido abordar una demanda asistencial desorbitada y una rápida toma de decisiones. Se han desarrollado estrategias para garantizar la disponibilidad y la dispensación de medicamentos, y favorecer la mejora en la seguridad de su utilización. Fomentar la comunicación dentro del propio servicio y con urgencias ha sido otra de las estrategias imprescindibles potenciadas durante la pandemia. La cooperación multidisciplinar y la coordinación de la información siempre serán la base de un trabajo eficiente y de calidad, junto con sistemas informáticos bien desarrollados como pieza clave en la seguridad del proceso de utilización de medicamentos. El impulso de las tecnologías para la información y la comunicación durante la pandemia quizá permita un nuevo modelo de atención farmacéutica que no debería sustituir la actividad presencial del farmacéutico en urgencias; es imprescindible

The COVID-19 pandemic is placing huge strain on health systems and professionals. Emergency departments and their pharmacy services have been the first to face this challenge before any other pharmacy units. This article provides a description of the experience of two public hospitals located in the Autonomous Community of Madrid, Spain. Team working and reciprocal trust have made it possible to meet the unprecedented demand for health services and has facilitated rapid decision making. Strategies have been developed to guarantee the availability, distribution and safe use of medications. Other strategies have included favoring communication within Emergency Departments pharmacy services, and between these services and Emergency Departments during the pandemic. Multidisciplinary cooperation and information sharing have traditionally formed the base for efficient and quality work, along with solid technologies that guarantee a safe use of medications. The crucial role of information and communication technologies during the pandemic may give rise to a new model of pharmaceutical care, which should not replace face-to-face Emergency Department pharmacist support and advice. Promoting the re-humanization of healthcare and pharmacy services is essential. An adequate technical training and the development of abilities such as flexibility, planning and coordination skills, and an assertive

Reductive Radical Cascades Triggered by Alkoxyl Radicals in the ß-Cyclodextrin Framework.

The generation and fate of 2I-VII,3I-VII,6II-VII-icosa- O-methyl-ß-cyclomaltoheptaos-6I- O-yl radical under reductive conditions is described. Two radical cascade reactions are involved: the main one is triggered by a 1,8-HAT of the hydrogen at 5VIIC. The radical can reach the anomeric hydrogen at 1VC three sugar units ahead using a six-step sequence. The different hydrogen donor ability of the group 14 hydrides permits one to selectively stop the cascade at 5VIIC, 2VIC, and 4VIC to obtain ß-CD with a ß-l-Ido p unit, acyclic hepta-, and hexa-saccharide structures, respectively.

Perception survey on the value of the hospital pharmacist at the emergency department / Encuesta de percepción del valor del farmacéutico de hospital en el servicio de urgencias

Objective: To determine the perception and evaluation of the Emergency pharmacist by the medical and nursing staff at the Emergency department. Methods: A multicenter study based on a survey sent to the Spanish Society of Hospital Pharmacists (SEFH) for Emergency pharmacists (EPh) to distribute among the Emergency staff. Descriptive statistics were used, with a 95% confidence interval. Results: 102 (12%) questionnaires were completed by 73 Emergency Physicians (71.6%) and 29 Emergency Nurses (28.4%), out of 835 surveys sent. The most common pharmaceutical activities, and perceived as more relevant for patient safety, were: consultation solution, prescription validation, and medication reconciliation. 63% of respondents supported the prospective review of high-risk medications, while 89% believed that the Pharmacist improves the quality of care. EPh are considered useful for training healthcare staff and patients, and 77% of respondents considered them as an integral member of the team. They would resort more to Pharmacists if they were present at the hospital department. Conclusions: The results show the acceptance of Hospital Pharmacists in the Emergency Department; their functions are known and valued. They are considered an integral member of the team, who will provide safety and improve patient care Medication reconciliation and prescription validation are highlighted because of their relevance in terms of safety. Further studies are needed to assess health outcomes and their economic impact (AU)

Objetivo: Determinar la percepción y valoración del farmacéutico de Urgencias por el personal médico y de enfermería de este servicio. Métodos: Estudio multicéntrico basado en una encuesta que se envió a la SEFH para que los farmacéuticos de Urgencias lo dirigieran al personal de esta unidad. Se aplica una estadística descriptiva con intervalos de confianza del 95%. Resultados: 102 (12%) encuestas cumplimentadas por 73 médicos (71,6%) y 29 enfermeras (28,4%) de Urgencias, de un total de 835 enviadas. Se aprecian como actividades farmacéuticas más comunes y relevantes para la seguridad del paciente: la resolución de consultas, la validación de prescripciones y la conciliación de la medicación. El 63% apoya la validación prospectiva de los medicamentos de alto riesgo. Para el 89% el farmacéutico mejora la calidad de la atención. Lo consideran útil en la formación del personal sanitario y de los pacientes y, para un 77% del total, es parte integral del equipo. Recurren más a él si está presente en el servicio. Conclusiones: Los resultados muestran la aceptación del farmacéutico de hospital en Urgencias; se conocen y valoran sus funciones. Es considerado parte integral del equipo, aporta seguridad y mejora la atención de los pacientes. Se refuerzan la conciliación de la medicación y la validación de las prescripciones por su relevancia en la seguridad. Su visibilidad facilita que recurran a sus servicios, si bien un reciente informe de la SEFH refleja una reducida presencia en las Urgencias hospitalarias. Hacen falta más estudios que valoren los resultados en salud y su repercusión económica (AU)

Perception survey on the value of the hospital pharmacist at the emergency department.

OBJECTIVE: To determine the perception and evaluation of the Emergency pharmacist by the medical and nursing staff at the Emergency department. METHODS: A multicenter study based on a survey sent to the Spanish Society of Hospital Pharmacists (SEFH) for Emergency pharmacists (EPh) to distribute among the Emergency staff. Descriptive statistics were used, with a 95% confidence interval. RESULTS: 102 (12%) questionnaires were completed by 73 Emergency Physicians (71.6%) and 29 Emergency Nurses (28.4%), out of 835 surveys sent. The most common pharmaceutical activities, and perceived as more relevant for patient safety, were: consultation solution, prescription validation, and medication reconciliation. 63% of respondents supported the prospective review of high-risk medications, while 89% believed that the Pharmacist improves the quality of care. EPh are considered useful for training healthcare staff and patients, and 77% of respondents considered them as an integral member of the team. They would resort more to Pharmacists if they were present at the hospital department. CONCLUSIONS: The results show the acceptance of Hospital Pharmacists in the Emergency Department; their functions are known and valued. They are considered an integral member of the team, who will provide safety and improve patient care. Medication reconciliation and prescription validation are highlighted because of their relevance in terms of safety. Further studies are needed to assess health outcomes and their economic impact.

Objetivo: Determinar la percepción y valoración del farmacéutico de Urgencias por el personal médico y de enfermería de este servicio.Métodos: Estudio multicéntrico basado en una encuesta que se envió a la SEFH para que los farmacéuticos de Urgencias lo dirigieran al personal de esta unidad. Se aplica una estadística descriptiva con intervalos de confianza del 95%.Resultados: 102 (12%) encuestas cumplimentadas por 73 médicos (71,6%) y 29 enfermeras (28,4%) de Urgencias, de un total de 835 enviadas. Se aprecian como actividades farmacéuticas más comunes y relevantes para la seguridad del paciente: la resolución de consultas, la validación de prescripciones y la conciliación de la medicación. El 63% apoya la validación prospectiva de los medicamentos de alto riesgo. Para el 89% el farmacéutico mejora la calidad de la atención. Lo consideran útil en la formación del personal sanitario y de los pacientes y, para un 77% del total, es parte integral del equipo. Recurren más a él si está presente en el servicio. Conclusiones: Los resultados muestran la aceptación del farmacéutico de hospital en Urgencias; se conocen y valoran sus funciones. Es considerado parte integral del equipo, aporta seguridad y mejora la atención de los pacientes. Se refuerzan la conciliación de la medicación y la validación de las prescripciones por su relevancia en la seguridad. Su visibilidad facilita que recurran a sus servicios, si bien un reciente informe de la SEFH refleja una reducida presencia en las Urgencias hospitalarias. Hacen falta más estudios que valoren los resultados en salud y su repercusión económica.

Radical-Mediated C-H Functionalization: A Strategy for Access to Modified Cyclodextrins.

A simple and efficient radical C-H functionalization to access modified cyclodextrins (CDs) has been developed. The well-defined conformation of glycosidic and aglyconic bonds in α-, ß-, and γ-CDs favors the intramolecular 1,8-hydrogen atom transfer (HAT) promoted by the 6I-O-yl radical, which abstracts regioselectively the hydrogen at C5II of the contiguous pyranose. The C5II-radical evolves by a polar crossover mechanism to a stable 1,3,5-trioxocane ring between two adjacent glucoses or alternatively triggers the inversion of one α-d-glucose into a 5-C-acetoxy-ß-l-idose unit possessing a 1C4 conformation. The 6I,IV- and 6I,III-diols of α- and ß-CDs behave similarly to the monoalcohols, forming mostly compounds originating from two 1,8-HAT consecutive processes. In the case of 6I,II-diols the proximity of the two 6-O-yl radicals in adjacent sugar units allows the formation of unique lactone rings within the CD framework via a 1,8-HAT-ß-scission tandem mechanism. X-ray diffraction carried out on the crystalline 1,4-bis(trioxocane)-α-CD derivative shows a severe distortion toward a narrower elliptical shape for the primary face.

Easy access to modified cyclodextrins by an intramolecular radical approach.

A simple method to modify the primary face of cyclodextrins (CDs) is described. The 6(I)-O-yl radical of α-, ß-, and γ-CDs regioselectively abstracts the H5(II), located in the adjacent D-glucose unit, by an intramolecular 1,8-hydrogen-atom-transfer reaction through a geometrically restricted nine-membered transition state to give a stable 1,3,5-trioxocane ring. The reaction has been extended to the 1,4-diols of α- and ß-CD to give the corresponding bis(trioxocane)s. The C2-symmetric bis(trioxocane) corresponding to the α-CD is a stable crystalline solid whose structure was confirmed by X-ray diffraction analysis. The calculated geometric parameters confirm that the primary face is severely distorted toward a narrower elliptical shape for this rim.

Photochemistry of α-diketones in carbohydrates: anomalous Norrish type†II photoelimination and Norrish-Yang photocyclization promoted by the internal carbonyl group.

A series of four α-diketones placed as 1α-pyruvoyl tethers on D-glucopyranose and D-glucopyranosiduronic acid skeletons was prepared in order to determine the influence of captodative and stereoelectronic effects on the regioselectivity of the hydrogen atom transfer (HAT) in Norrish type II photochemical processes. We observed that the 1,5-HAT regioselectivity can be switched between the two potentially abstractable syn-1,3-diaxial hydrogens at H6 and H8. Highly unusual photoproducts from Norrish type II photoelimination and Norrish-Yang photocyclization initiated by the excited internal carbonyl group were obtained, in some cases in excellent synthetic yield. The 1,5-HAT transition state in the Norrish type II photoelimination was investigated by photochemical experiments in the crystalline state.

Sequential Norrish type†II photoelimination and intramolecular aldol cyclization of α-diketones: synthesis of polyhydroxylated cyclopentitols by ring contraction of hexopyranose carbohydrate derivatives.

The excitation of the innermost carbonyl of nono-2,3-diulose derivatives by irradiation with visible-light initiates a sequential Norrish type II photoelimination and aldol cyclization process that finally gives polyfunctionalized cyclopentitols. The rearrangement has been confirmed by the isolation of stable acyclic photoenol intermediates that can be independently cyclized by a thermal 5-(enolexo)-exo-trig uncatalyzed aldol reaction with high diastereoselectivity. In this last step, the large deuterium kinetic isotope effect found for the 1,5-hydrogen atom transfer seems to indicate that the aldol reaction runs through a concerted pericyclic mechanism. Owing to the ready availability of pyranose sugars of various configurations, this protocol has been used to study the influence of pyranose ring-substituents on the diastereoselectivity of the aldol cyclization reaction. In contrast with other pyranose ring contraction methodologies no transition-metal reagents are needed and the sequential rearrangement occurs simply by using visible light and moderate heating (0 to 60 °C).

Intramolecular 1,8-hydrogen atom transfer reactions in disaccharide systems containing furanose units.

A previously developed 1,8-hydrogen atom transfer (HAT) reaction promoted by 6-O-yl alkoxyl radicals between the two pyranose units in Hexp-(1→4)-Hexp disaccharides has been extended to other systems containing at least a furanose ring in their structures. In Penf-(1→3)-Penf (A) and Hexp-(1→3)-Penf (B) disaccharides, the 1,8-HAT reaction and concomitant cyclization to a 1,3,5-trioxocane ring are in competition with radical ß-scission of the C4-C5 bond and formation of dehomologated products. The influence of the stereoelectronic ß-oxygen effect on the ß-scission and consequently on the 1,8-HAT reaction has been studied using the four possible isomeric d-furanoses. d-xylo- and d-lyxo-derivatives afforded preferentially 1,8-HAT products, whereas d-arabino- and d-ribo-derivatives gave exclusively direct ß-scission of the alkoxyl radical. When the 6-O-yl radical is on a pyranose ring, as occurs in Penf-(1→4)-Hexp (C), it has been shown to provide the cyclized products exclusively.

Intramolecular 1,8-hydrogen-atom transfer reactions in (1-->4)-O-disaccharide systems: conformational and stereochemical requirements.

The stereochemical and conformational factors controlling the intramolecular hydrogen-atom transfer (HAT) reaction between the two pyranose units in a (1-->4)-O-disaccharide when promoted by a primary 6-O-yl radical are studied. Models with alpha-D-Glcp-(1-->4)-beta-D-Glcp, alpha-L-Rhamp-(1-->4)-alpha-D-Galp or alpha-D-Manp-(1-->4)-beta-L-Gulp skeletons led exclusively to the abstraction of the hydrogen from H--C-5' and the formation, through a nine-membered transition state, of a 1,3,5-trioxocane ring system in a stable boat-chair conformation. Notwithstanding, derivatives of alpha-L-Rhamp-(1-->4)-alpha-D-Glcp or alpha-D-Manp-(1-->4)-alpha-D-Galp exclusively abstract the hydrogen from H--C-1' through a seven-membered transition state and, therefore, lead to an interglycosidic spiro ortho ester.

Intramolecular 1,8-hydrogen atom transfer. Stereoselectivity of the hexopyranos-5'-yl radical reactions in Hex p-(1-->4)-Hex p disaccharide systems.

The stereoselective reduction of hexopyranos-5'-yl radicals in alpha-D-Hex p-(1-->4)-D-Hex p disaccharide models is described. These radicals are generated from a 6-O-yl radical located in the other monosaccharic unit through a 1,8-hydrogen atom transfer. The reaction, which is strongly influenced by steric and stereoelectronic effects, permits in some cases the transformation of alpha-D-Hex p-(1-->4)-D-Hex p into beta-L-Hex p-(1-->4)-D-Hex p disaccharides in a single step with high diastereoselectivity.

[Alcohol drinking parties and consumption of alcohol and other drugs in youth]. / El botellón y el consumo de alcohol y otras drogas en la juventud.

The main aim of this paper is to analyze the relationships of involvement in the "botellon" (meetings of youth in public places to drink, chat, etc.) with alcohol/other drug abuse and vandalism in young people. A school survey was performed in centres of Compulsory Secondary School (E.S.O.), high school, professional training and University education in Lugo, NW Spain. The sample (aged 12 to 30) was split into three groups according to alcohol use and botellon involvement; drug abuse, drug-related problems and vandalism were assessed in each group. Results indicate that regular botellon attendants display more problems with alcohol and other drugs, as well as higher involvement in vandalism; this relationship is stronger among young students. The increase in adolescent risk associated with the practice of the botellon is explained by peer group pressure to use drugs and the greater accessibility of alcohol/other drugs in these contexts.

El botellón y el consumo de alcohol y otras drogas en la juventud / «Botellon» and alcohol and other drug use in youth

El objetivo de este trabajo es analizar la relación existente entre la participación en el botellón (reuniones de jóvenes en espacios públicos para beber, charlar, etc.), el abuso de alcohol y otras drogas y la realización de conductas vandálicas en jóvenes. Para ello se ha realizado una encuesta escolar en centros educativos de Secundaria, Bachillerato, ciclos de Formación Profesional y Universidad en la ciudad de Lugo. La muestra, de edades comprendidas entre los 12 y los 30 años, fue dividida en tres grupos en función de su consumo de alcohol y la participación en el botellón, y se analizó el nivel de abuso de drogas, los problemas asociados con esos abusos y el grado de implicación en actos vandálicos. Los resultados muestran que aquellos que participan habitualmente en el botellón presentan mayores problemas con el alcohol y otras drogas. Son también los que más actos vandálicos realizan. Esa relación se observa con mayor intensidad en los estudiantes más jóvenes. El incremento del riesgo en los adolescentes asociado a la práctica del botellón es explicado por la presión del grupo de amigos hacia el consumo y por la mayor accesibilidad al alcohol y otras drogas en estos contextos (AU)

The main aim of this paper is to analyze the relationships of involvement in the "botellon" (meetings of youth in public places to drink, chat, etc.) with alcohol/other drug abuse and vandalism in young people. A school survey was performed in centres of Compulsory Secondary School (E.S.O.), high school, professional training and University education in Lugo, NW Spain. The sample (aged 12 to 30) was split into three groups according to alcohol use and botellon involvement; drug abuse, drug-related problems and vandalism were assessed in each group. Results indicate that regular botellon attendants display more problems with alcohol and other drugs, as well as higher involvement in vandalism; this relationship is stronger among young students. The increase in adolescent risk associated with the practice of the botellon is explained by peer group pressure to use drugs and the greater accessibility of alcohol/other drugs in these contexts (AU)

Intramolecular 1,8- versus 1,6-hydrogen atom transfer between pyranose units in a (1-->4)-disaccharide model promoted by alkoxyl radicals. Conformational and stereochemical requirements.

[reaction: see text] The stereochemical and conformational factors controlling the intramolecular hydrogen atom transfer (HAT) reaction between the two pyranose units in a (1-->4)-disaccharide when promoted by a primary 6-O-yl radical are studied. Models with alpha-d-Glcp-(1-->4)-beta-d-Glcp or alpha-l-Rhamp-(1-->4)-alpha-d-Galp skeletons lead exclusively to the abstraction of H-C-5' and the formation, through a nine-membered transition state, of a 1,3,5-trioxocane ring system in a stable boat-chair conformation. Notwithstanding, derivatives of alpha-l-Rhamp-(1-->4)-alpha-d-Glcp abstract exclusively H-C-1' through a seven-membered transition state and therefore lead to an interglycosidic spiro ortho ester.