RESUMEN
Degradation mechanisms affecting non-methane volatile organic compounds (VOCs) during gas uprising from different hypogenic sources to the surface were investigated through extensive sampling surveys in areas encompassing a high enthalpy hydrothermal system associated with active volcanism, a CH4-rich sedimentary basin and a municipal waste landfill. For a comprehensive framework, published data from medium-to-high enthalpy hydrothermal systems were also included. The investigated systems were characterised by peculiar VOC suites that reflected the conditions of the genetic environments in which temperature, contents of organic matter, and gas fugacity had a major role. Differences in VOC patterns between source (gas vents and landfill gas) and soil gases indicated VOC transformations in soil. Processes acting in soil preferentially degraded high-molecular weight alkanes with respect to the low-molecular weight ones. Alkenes and cyclics roughly behaved like alkanes. Thiophenes were degraded to a larger extent with respect to alkylated benzenes, which were more reactive than benzene. Furan appeared less degraded than its alkylated homologues. Dimethylsulfoxide was generally favoured with respect to dimethylsulfide. Limonene and camphene were relatively unstable under aerobic conditions, while α-pinene was recalcitrant. O-bearing organic compounds (i.e., aldehydes, esters, ketones, alcohols, organic acids and phenol) acted as intermediate products of the ongoing VOC degradations in soil. No evidence for the degradation of halogenated compounds and benzothiazole was observed. This study pointed out how soil degradation processes reduce hypogenic VOC emissions and the important role played by physicochemical and biological parameters on the effective VOC attenuation capacity of the soil.
RESUMEN
Landfills for solid waste disposal release to the atmosphere a large variety of volatile organic compounds (VOCs). Bacterial activity in landfill cover soils can play an important role in mitigating VOC emission. In order to evaluate the effects of degradation processes and characterize VOCs composition in landfill cover soil, gases from 60 sites and along 7 vertical profiles within the cover soil were collected for chemical and isotopic analysis at two undifferentiated urban solid waste disposal sites in Spain: (i) Pinto (Madrid) and (ii) Zurita (Fuerteventura, Canary Islands). The CO2/CH4 ratios and δ13C-CO2 and δ13C-CH4 values were controlled by either oxidation or reduction processes of landfill gas (LFG). VOCs were dominated by aromatics, alkanes and O-substituted compounds, with minor cyclics, terpenes, halogenated and S-substituted compounds. Degradation processes, depending on both (i) waste age and (ii) velocity of the uprising biogas through the soil cover, caused (i) an increase of degradation products (e.g., CO2, O-substituted compounds) and (ii) a decrease of degradable components (e.g., CH4, alkanes, alkylated aromatics, cyclic and S-substituted compounds). Terpenes, halogenated compounds, phenol and furans were unaffected by degradation processes and only depended on waste composition. These results highlight the fundamental role played by microbial activity in mitigating atmospheric emissions of VOCs from landfills. Nevertheless, the recalcitrant behaviour shown by compounds hazardous for health and environment remarks the importance of a correct landfill management that has to be carried out for years after the waste disposal activity is completed, since LFG emissions can persist for long time.
RESUMEN
Although the surgical procedures concerning the thyroid and the parathyroid glands are considered safe, the possible occurrence of complications (mainly hematoma and hypocalcemia) limit the short stay surgery. At our institution a 23-hour-surgery with overnight hospital stay for endocrine neck surgical procedures was introduced since 2004. The present case series analyses the institutional results. Over 1913 endocrine neck surgery procedures, 1730 patients (90,2%) were managed according to this model. Among these patients, 92 suffered from hypocalcemia, 12 from airways obstruction due to the hematoma, 5 from bilateral nerve palsy. 15 more patients had unpredictable general disease compromising the short-stay surgery management. The goal of the discharge after 23 hours was achieved in 92,8% of cases with a mean hospital stay of 1,1days. The 23-hour observation with an overnight surgery is feasible and safe if the correct indications are observed. A considerable volume of specific activity is needed.
Asunto(s)
Monitoreo Fisiológico/estadística & datos numéricos , Paratiroidectomía , Cuidados Posoperatorios/estadística & datos numéricos , Complicaciones Posoperatorias/epidemiología , Tiroidectomía , Humanos , Tiempo de Internación/estadística & datos numéricos , Factores de Tiempo , Resultado del TratamientoRESUMEN
BACKGROUND AND AIMS: Recent epidemiological studies showed an increase in ulcerative colitis among children, especially in its aggressive form, requiring surgical treatment. Although medical therapeutic strategies are standardized, there is still no consensus regarding indications, timing and kind of surgery. This study aimed to define the surgical management of paediatric ulcerative colitis and describe attitudes to it among paediatric surgeons. METHODS: This was a retrospective cohort study. All national gastroenterology units were invited to participate. From January 2009 to December 2013, data on paediatric patients diagnosed with ulcerative colitis that required surgery were collected. RESULTS: Seven units participated in the study. Seventy-one colectomies were performed (77.3% laparoscopically). Main surgical indications were a severe ulcerative colitis attack (33.8%) and no response to medical therapies (56.3%). A three-stage strategy was chosen in 71% of cases. Straight anastomosis was performed in 14% and J-pouch anastomosis in 86% of cases. A reconstructive laparoscopic approach was used in 58% of patients. Ileo-anal anastomosis was performed by the Knight-Griffen technique in 85.4% and by the pull-through technique in 9.1% of patients. Complications after colectomy, after reconstruction and after stoma closure were reported in 12.7, 19.3 and 35% of cases, respectively. CONCLUSIONS: This study shows that there is general consensus regarding indications for surgery. The ideal surgical technique remains under debate. Laparoscopy is a procedure widely adopted for colectomy but its use in reconstructive surgery remains limited. Longer follow-up must be planned to define the quality of life of these patients.
Asunto(s)
Actitud del Personal de Salud , Colitis Ulcerosa/cirugía , Gastroenterología , Proctocolectomía Restauradora/métodos , Adolescente , Niño , Preescolar , Colitis Ulcerosa/tratamiento farmacológico , Colostomía/efectos adversos , Defecación , Resistencia a Medicamentos , Incontinencia Fecal/etiología , Femenino , Humanos , Italia , Masculino , Reservoritis/etiología , Proctocolectomía Restauradora/efectos adversos , Estudios Retrospectivos , Índice de Severidad de la EnfermedadAsunto(s)
Daño del ADN , Reparación del ADN , ADN , Técnicas Genéticas , Mutagénesis , Oligonucleótidos/química , AnimalesRESUMEN
Several researches have been devoted to structure-activity relationship and to post-SELEX modifications of the thrombin binding aptamer (TBA), one of the first aptamers discovered by the SELEX methodology. However, no studies on TBA dealing with the effects of introduction of inversion of polarity sites have been reported yet. In this frame, we have undertaken the synthesis and the study of a mini-library composed of several TBA analogues containing a 3'-3' or a 5'-5' inversion of polarity site at different positions into the sequence. Particularly, in this article, we present preliminary results about their structural and biological properties.
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Aptámeros de Nucleótidos/química , Trombina/antagonistas & inhibidores , Secuencia de Bases , Dicroismo Circular , Biblioteca de Genes , Modelos Moleculares , Resonancia Magnética Nuclear Biomolecular , Conformación de Ácido Nucleico , Técnica SELEX de Producción de Aptámeros , TermodinámicaRESUMEN
Preliminary NMR studies on structure formed by sequence 3'-TGA-5'-5'-GGT-3' are described. We proposed the formation of a tetramolecular quadruplex in which strands are equivalent to each other and three G-tetrads are present. The possibility of the occurrence of an A-tetrad also is discussed.
Asunto(s)
Oligodesoxirribonucleótidos/química , Secuencia de Bases , Modelos Moleculares , Resonancia Magnética Nuclear Biomolecular , Conformación de Ácido NucleicoRESUMEN
Previous research has shown that the immunomodulatory peptide alpha-melanocyte-stimulating hormone (alpha-MSH) and its carboxy-terminal tripeptide KPV (Lys-Pro-Val alpha-MSH11-13) have antimicrobial influences. By inserting a Cys-Cys linker between two units of KPV, we designed the dimer [Ac-CKPV]2 that showed excellent candidacidal effects in pilot tests and was the subject of further investigations. [Ac-CKPV]2 was active against azole-resistant Candida spp. Therefore, the molecule appeared a promising candidate for therapy of fungal infections and was the subject of a structural study. 1H-NMR and restrained mechanic and dynamic calculations suggest that the peptide adopts an extended backbone structure with a beta-turn-like structure. These results open a pathway to development of additional novel compounds that have candidacidal effects potentially useful against clinical infections.
Asunto(s)
Antifúngicos/farmacología , Candida/efectos de los fármacos , alfa-MSH/química , Espectroscopía de Resonancia Magnética , Oligopéptidos/química , Conformación Proteica , alfa-MSH/análogos & derivados , alfa-MSH/farmacologíaRESUMEN
Two new metabolites, named halipeptins A and B, have been isolated from the marine sponge Haliclona sp. Their structures were determined by extensive use of one- and two-dimensional NMR experiments, mass spectrometry, and UV and IR spectroscopy. Halipeptin A is a novel 17-membered cyclic depsipeptide, consisting of five residues including two alanines (with L stereochemistry) and three new residues that appear to be previously undescribed from natural sources: 1,2-oxazetidine-4-methyl-4-carboxylic acid, 3-hydroxy-2,2,4-trimethyl-7-methoxydecanoic acid (HTMMD), and N-methyl-delta-hydroxyisoleucine. The HTMMD residue is substituted with 3-hydroxy-2,2,4-trimethyl-7-hydroxydecanoic acid in halipeptin B. Halipeptin A was found to possess very potent anti-inflammatory activity in vivo, causing about 60% inhibition of edema in mice at the dose of 300 microg/kg (i.p.).
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Antiinflamatorios no Esteroideos/química , Depsipéptidos , Péptidos Cíclicos/química , Péptidos Cíclicos/aislamiento & purificación , Poríferos/química , Animales , Antiinflamatorios no Esteroideos/aislamiento & purificación , Antiinflamatorios no Esteroideos/farmacología , Relación Dosis-Respuesta a Droga , Edema/tratamiento farmacológico , Humanos , Leucemia L1210/tratamiento farmacológico , Masculino , Ratones , Pruebas de Sensibilidad Microbiana , Resonancia Magnética Nuclear Biomolecular , Péptidos Cíclicos/farmacología , Conformación Proteica , Espectrometría de Masa Bombardeada por Átomos Veloces , Estereoisomerismo , Células Tumorales Cultivadas/efectos de los fármacosRESUMEN
The S100 subfamily of EF-hand proteins is distinguished by the binding of Zn(2+) in addition to Ca(2+). In an effort to understand the role of Zn(2+) in modulating the activity of S100 proteins, we have carried out heteronuclear NMR studies of Zn(2+)-bound S100A2 and obtained near complete resonance assignments. This analysis revealed an equilibrium between multiple isoforms due to cis-trans isomerism of proline residues in flexible regions of the protein. The secondary structure of S100A2 has been determined based on the NMR chemical shift index (CSI) technique. The protein is found to possess essentially the same secondary structure found in other S100 proteins such as S100A6 and S100B. Homology models have been built based on the high resolution three-dimensional structures of other S100 proteins. The models predict two Zn(2+) binding clusters, one involving residues His17-Cys21-Cys93 and the other Cys2-His39, and with Cys86 participating in either the N-terminal or the C-terminal binding site.
Asunto(s)
Proteínas de Ciclo Celular , Factores Quimiotácticos/química , Proteínas S100/química , Zinc/química , Proteínas de Unión al Calcio/química , Proteínas Portadoras/química , Humanos , Espectroscopía de Resonancia Magnética/métodos , Modelos Moleculares , Factores de Crecimiento Nervioso/química , Conformación Proteica , Reproducibilidad de los Resultados , Proteína A6 de Unión a Calcio de la Familia S100 , Proteína A7 de Unión a Calcio de la Familia S100 , Subunidad beta de la Proteína de Unión al Calcio S100 , Homología de Secuencia de AminoácidoRESUMEN
BACKGROUND: Non-valvular paroxysmal atrial fibrillation is a common clinical condition associated with a high risk of thromboembolism and hemodynamic problems which increase with the duration of arrhythmia. Therefore, even if arrhythmia ceases spontaneously within 24 hours in about half of the patients, a higher early conversion rate is desirable. Propafenone either by intravenous or oral load has been shown effective in conversion to sinus rhythm. METHODS: We consecutively randomized all emergency patients with non-valvular atrial fibrillation lasting no more than 48 hours to either intravenous or oral initial load of propafenone. They all received further oral doses if still on atrial fibrillation after the initial load. Exclusion criteria were: mean ventricular rate < 65 b/min, age > 75 years, recent acute myocardial infarction, overt heart failure, conduction defects, ventricular preexcitation, thyroid dysfunction, renal or hepatic insufficiency, pregnancy, current treatment with propafenone or other antiarrhythmic drugs, and intolerance to propafenone. Primary and secondary end-points were the conversion to sinus rhythm within 12 and 48 hours of randomization respectively. RESULTS: Ninety-seven patients were randomized to intravenous (n = 49) or oral (n = 48) treatment. Overall, sinus rhythm restoration occurred in 83.3% of patients within 12 hours and in 98.9% at 24 hours. Recovery rate resulted significantly greater for intravenous treatment at 1 and 3 hours (p < 0.001 and p = 0.001, respectively). At 6, 12 and 24 hours no significant difference between the two groups was observed (p = 0.77, p = 0.81 and p = 0.99, respectively). No patient needed treatment suspension. CONCLUSIONS: In patients with recent-onset non-valvular atrial fibrillation treated with propafenone within 48 hours, conversion to sinus rhythm occurred in more than 80% within 12 hours. Even if intravenous initial load appears to be slightly more rapid, the oral way is easier to administer and cheaper. The choice may depend on the specific organization of the single emergency room.
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Antiarrítmicos/administración & dosificación , Fibrilación Atrial/tratamiento farmacológico , Propafenona/administración & dosificación , Administración Oral , Adulto , Anciano , Anciano de 80 o más Años , Fibrilación Atrial/fisiopatología , Presión Sanguínea , Servicio de Urgencia en Hospital , Femenino , Frecuencia Cardíaca , Humanos , Infusiones Intravenosas , Masculino , Persona de Mediana EdadRESUMEN
CONTEXT: Intermittent use (i.e., a few nights per week) of hypnotic medication is often recommended for the treatment of chronic insomnia despite an absence of efficacy and safety data using this regimen. STUDY OBJECTIVES: To evaluate the clinical efficacy and safety of intermittent pharmacotherapy for chronic insomnia. DESIGN AND SETTING: Randomized, double-blind, placebo-controlled, parallel groups, clinical trial at six sleep research sites. PATIENTS: One hundred-sixty-three (115 women, 48 men; mean age 44.1+ SE. 0.9 years), DSM-IV-defined primary insomnia patients were randomized, 134 patients completed the study. INTERVENTIONS: Eight weeks of treatment with either zolpidem 10 mg or placebo. Patients were instructed to take medication when they felt they needed it, but at least three and no more than five times per week. MAIN OUTCOME MEASURES: Investigator and Patient Global Ratings were the primary outcome variables. Secondary measures from daily questionnaires to assess efficacy, rebound insomnia and drug taking behavior. RESULTS: The Investigator's Global Rating indicated that intermittent use of zolpidem produced a significantly better therapeutic effect and significantly reduced insomnia severity throughout the 8-week study relative to placebo. Zolpidem was found to be effective in initiating and maintaining sleep on nights taken, as compared to placebo, based upon the Patient's Global Ratings and all subjective sleep variables. No evidence of rebound insomnia was found on nights that zolpidem was not taken. The number of nights a pill was taken did not differ between groups, nor did frequency of pill taking change in either group across the duration of the study. There were no significant effects of treatment upon quality of life or neurocognitive measures. CONCLUSIONS: Zolpidem 10 mg is effective in treating insomnia when used intermittently, without evidence of discontinuation effects or increased frequency of pill taking.
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Hipnóticos y Sedantes/administración & dosificación , Hipnóticos y Sedantes/uso terapéutico , Piridinas/administración & dosificación , Piridinas/uso terapéutico , Trastornos del Inicio y del Mantenimiento del Sueño/tratamiento farmacológico , Análisis de Varianza , Método Doble Ciego , Esquema de Medicación , Humanos , Encuestas y Cuestionarios , Factores de Tiempo , ZolpidemRESUMEN
The marine product petrosaspongiolide M is a novel inhibitor of phospholipase A2 (PLA2), showing selectivity for secretory PLA2 versus cytosolic PLA2, with a potency on the human synovial enzyme (group II) similar to that of manoalide. This compound was more potent than manoalide on bee venom PLA2 (group III) and had no effect on group I enzymes (Naja naja and porcine pancreatic PLA2). Inhibition of PLA2 was also observed in vivo in the zymosan-injected rat air pouch, on the secretory enzyme accumulated in the pouch exudate. Petrosaspongiolide M decreased carrageenan paw edema in mice after the oral administration of 5, 10, or 20 mg/kg. This marine metabolite (0.01-1.0 micromol/pouch) induced a dose-dependent reduction in the levels of prostaglandin (PG)E2, leukotriene B4, and tumor necrosis factor-alpha in the mouse air pouch injected with zymosan 4 h after the stimulus. It also had a weaker effect on cell migration. The inflammatory response of adjuvant arthritis was reduced by petrosaspongiolide M, which also inhibited leukotriene B4 levels in serum and PGE2 levels in paw homogenates. In contrast with indomethacin, this marine compound did not reduce PGE2 levels in stomach homogenates. Petrosaspongiolide M is a new inhibitor of secretory PLA2 in vitro and in vivo, with anti-inflammatory properties in acute and chronic inflammation.
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Antiinflamatorios no Esteroideos/farmacología , Inhibidores Enzimáticos/farmacología , Inflamación/tratamiento farmacológico , Ácido Oleanólico/análogos & derivados , Fosfolipasas A/antagonistas & inhibidores , Animales , Artritis Experimental/tratamiento farmacológico , Supervivencia Celular/efectos de los fármacos , Dinoprostona/metabolismo , Edema/inducido químicamente , Edema/tratamiento farmacológico , Exudados y Transudados/enzimología , Exudados y Transudados/metabolismo , Humanos , Técnicas In Vitro , Inflamación/patología , Leucocitos/efectos de los fármacos , Leucotrieno B4/metabolismo , Masculino , Ratones , Ácido Oleanólico/farmacología , Fosfolipasas A2 , Poríferos/química , Ratas , Ratas Endogámicas Lew , Ratas Wistar , Factor de Necrosis Tumoral alfa/metabolismo , Células U937RESUMEN
Five new bioactive sesterterpenes (1-5) have been isolated from the New Caledonian marine sponge Petrosaspongia nigra Bergquist and named petrosaspongiolides M-R. Their chemical structures were determined from 1D and 2D NMR studies and MS data. All compounds inhibited different preparations of phospholipase A2 (PLA2) by irreversibly blocking these enzymes (particularly human synovial and bee venom, see Table 3), with IC50 values in the micromolar range. Interestingly, these compounds displayed a much lower activity (or no activity at all) toward porcine pancreas and Naja naja venom PLA2 enzymes. The most potent compound, 1 (IC50 1.6 and 0.6 microM for human synovial and bee venom PLA2 enzymes, respectively), was slightly more active than manoalide (6) (IC50 3.9 and 7.5 microM) under our experimental conditions. Compound 3 is more selective, inhibiting human synovial PLA2 to a greater extent than bee venom PLA2.
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4-Butirolactona/análogos & derivados , Inhibidores Enzimáticos/aislamiento & purificación , Fosfolipasas A/antagonistas & inhibidores , Poríferos/química , Terpenos/aislamiento & purificación , 4-Butirolactona/química , 4-Butirolactona/aislamiento & purificación , 4-Butirolactona/farmacología , Animales , Venenos de Abeja/enzimología , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Humanos , Espectroscopía de Resonancia Magnética , Estructura Molecular , Páncreas/enzimología , Fosfolipasas A2 , Espectrometría de Masa Bombardeada por Átomos Veloces , Porcinos , Líquido Sinovial/enzimología , Terpenos/química , Terpenos/farmacologíaRESUMEN
STUDY OBJECTIVES: Various aspects of human performance were assessed in children after sleep loss. PARTICIPANTS: Sixteen children (7 males, 9 females) between the ages of 10 and 14 years. DESIGN AND INTERVENTIONS: Children were randomly assigned to either a control (CTRL) group, with 11 hours in bed, or an experimental sleep restriction (SR) group, with 5 hours in bed, on a single night in the sleep laboratory. MEASUREMENTS: Both groups were evaluated the following day with a battery of performance and sleepiness measures. Psychomotor and cognitive performance tests were given during four 1-hour testing sessions at 2-hour intervals. RESULTS: A multiple sleep latency test (MSLT) documented shorter latencies for SR children than controls. Significant treatment differences were discovered in three of four variables of verbal creativity, including fluency, flexibility, and average indices. There were also group differences found on the Wisconsin Card Sorting Test (WCST), which may be indicative of difficulty learning new abstract concepts. Measures of rote performance and less-complex cognitive functions, including measures of memory and learning and figural creativity, did not show differences between groups, perhaps because motivation could overcome sleepiness-related impairment for these tasks. CONCLUSIONS: Higher cognitive functions in children, such as verbal creativity and abstract thinking, are impaired after a single night of restricted sleep, even when routine performance is relatively maintained.
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Trastornos del Conocimiento/diagnóstico , Trastornos del Conocimiento/etiología , Síndromes de la Apnea del Sueño/complicaciones , Síndromes de la Apnea del Sueño/diagnóstico , Enfermedad Aguda , Adolescente , Niño , Preescolar , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Pruebas Neuropsicológicas , Desempeño Psicomotor , Factores de TiempoRESUMEN
Between July 1992 and June 1993, 61 patients with severe community-acquired pneumonia were admitted to our semi-intensive care unit. For all patients chest X-ray, blood gas analysis while breathing room air, Gram stain and culture of bronchoaspirate, determination of acute and convalescent anti-body titers for Legionella pneumophila, Mycoplasma pneumoniae and Chlamydia pneumoniae, blood culture when body temperature was greater than 38 degrees C, and pharyngeal swab for C. pneumoniae detection by means of an indirect immunofluorescence test were obtained. Among the patients enrolled, 15 suffered from chronic obstructive pulmonary disease, 18 had serious chronic diseases, 9 were immunodeficient and 15 had cardiovascular diseases, and only 4 had no underlying disease. Etiologic diagnosis was reached in 30 cases (49%). As expected, due to the high rate of seriously ill patients, gram-negative pathogens were identified most commonly (15%), followed by Streptococcus pneumoniae (10%) and, surprisingly, by C. pneumoniae (10%). These data, showing the possible emergence of Pseudomonas aeruginosa and C. pneumoniae, warrant further studies in order to verify whether the epidemiological pattern of severe community-acquired pneumonia is actually changing.
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Infecciones por Chlamydia , Chlamydophila pneumoniae , Infecciones Comunitarias Adquiridas/microbiología , Neumonía/microbiología , Anciano , Anciano de 80 o más Años , Infecciones Bacterianas , Femenino , Humanos , Masculino , Persona de Mediana Edad , Mortalidad , Neumonía/diagnóstico por imagen , Neumonía/mortalidad , Radiografía TorácicaRESUMEN
The present study was designed to investigate systolic time intervals (STI) in 100 normal subjects undergoing continuous-maximal supine cycle ergometry and to search for possible linear correlations between STI (dependent variables) and heart rate, diastolic blood pressure, systolic blood pressure, age, sex, weight, and height (independent variables), by stepwise regression analysis. The only significant correlation discovered in the study was between the contractility index (isometric contraction time-ICT) and the total work produced by each participant. Exercise tolerance was limited primarily by shortening of the ICT interval, all subjects discontinuing the test when ICT reached 13.7 +/- 7 ms.
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Prueba de Esfuerzo , Frecuencia Cardíaca , Contracción Miocárdica , Esfuerzo Físico , Sístole , Adulto , Electrocardiografía , Femenino , Humanos , Masculino , Monitoreo Fisiológico , Fonocardiografía , Análisis de RegresiónRESUMEN
Echocardiography was used to explore the influence of independent variables (age, body surface area and heart rate) on the mean circumferential shortening velocity (MVCF) in 183 healthy subjects. Multiple stepwise regression analysis shows that heart rate is the only variable of the three just mentioned that influences MVCF. A regression equation is evolved and proposed as an index of MVCF correction for varying heart rates.