Nervio interóseo posterior: origen, localización y trayecto nervioso: una revisión / Posterior interosseous nerve: origin, location and nerve path: a review

RESUMEN: El nervio interóseo posterior (NIP) ha sido utilizado como sinónimo ocontinuación inmediata del ramo profundo del nervio radial (RPNR) al emerger en el compartimiento posterior del antebrazo. Su origen tampoco es claro, describiéndose como nervio interóseo posterior a su trayecto proximal, intermedio o distal al músculo supinador. El objetivo de esta revisión es detallar la visión de diversos autores respecto al origen y trayecto del NIP, proponiendo una correcta terminología para estas estructuras. Se realizó una revisión bibliográfica de varios textos y de algunos artículos utilizados para la enseñanza de la anatomía humana, publicados entre los años 1800 y la actualidad. En la búsqueda, se determinaron criterios de inclusión que consideraban, anatomía humana, escritos en español, francés o inglés y que aludieran al NIP. Tras la exploración inicial se localizaron 18 libros, procedentes de Francia, Rusia, España, Argentina, Estados Unidos, Canadá, Reino Unido, Alemania, India y México. Una descripción del NIP más precisa, en cuanto al origen, trayecto y función, es aquella postulada por la vertiente francesa, correspondiendo a un origen terminal del ramo profundo del nervio radial, luego de emitir sus ramos musculares. Este delgado nervio transcurre adosado a la membrana interósea para luego avanzar por el cuarto compartimiento extensor, distribuyéndose en las articulaciones dorsales del carpo a quienes inerva sensitiva y propioceptivamente.

SUMMARY: The posterior interosseous nerve (PIN) has been used as a synonym or immediate continuation of the deep branch of the radial nerve as it emerges in the posterior compartment of the forearm. Its origin is not clear either, being described as a posterior interosseous nerve to its proximal, intermediate or distal path to the supinator muscle. The objective of this review is to detail the vision of various authors regarding the origin and path of the PIN, proposing a correct terminology for these structures. A bibliographic review of several texts and some articles used for the teaching of human anatomy, published between the 1800s and the present day, was carried out. In the search, inclusion criteria were determined that considered human anatomy, written in Spanish, French or English and that alluded to the PIN. After the initial exploration, 18 books were located, coming from France, Russia, Spain, Argentina, the United States, Canada, the United Kingdom, Germany, India and Mexico. A more precise description of the PIN, in terms of origin, path and function, is that postulated by the French literature, corresponding to a terminal origin of the deep branch of the radial nerve, after emitting its muscular branches. This thin nerve runs attached to the interosseous membrane to then advance through the fourth extensor compartment, distributing itself in the dorsal carpal joints to which it innervates sensitively and proprioceptively.

Geochemical and isotopic evidence for pumping-induced impacts to bedrock groundwater quality in the City of Guelph, Canada.

Groundwater can be a key water resource in urban environments, providing a source of freshwater for community needs. The City of Guelph relies on groundwater for a population of over 130,000 people. Thus, groundwater quality is a critical component of long-term water management. This study assesses the effect of urban, industrial and agriculture activities on groundwater quality using a suite of multidisciplinary methods including geological, hydrological, geochemical, and isotopic tools. Multi-level systems (with depth-discrete ports), conventional well clusters, and municipal production wells were used to monitor hydraulic head and collect groundwater samples. Geochemical and isotopic measurements included redox parameters, major anions and cations, VOC, tritium and δ34S and δ18O in sulfate. Hydraulic head data show vertical gradient profiles characteristic of a multi-layered flow system within a shallow and deep Silurian bedrock aquifer and an intermediate aquitard varying in occurrence. Head loss disappears near production wells, showing enhanced vertical hydraulic connectivity between shallow and deep aquifers, attributed to pumping and long open intervals. Hydrochemical data show no impact of nitrate and high chloride is observed in the shallow and deep aquifer, attributed to seasonal road salt and the underlying aquitard unit, respectively. The aquitard unit also control the high sulfate in the deep aquifer which is supported by the isotope data on sulfate. Facilitated transport of shallow groundwater into the deeper aquifer is supported by the tritium data, showing the presence of recent groundwater throughout the whole depth of the two aquifers in some areas, likely due to the varying aquitard presence and enhanced vertical flow due to proximity from pumping municipal wells and active rock quarry. The results of this research suggest long term implications for groundwater resource management of sedimentary bedrock aquifers, where there is increasing groundwater demand due to population growth and potential for continual water quality degradation.

Conocimiento y creencias sobre infección por clamidia en población joven. Revisión narrativa / Knowledge and beliefs about chlamydia infection in a young population. Narrative review

RESUMEN Introducción: La Chlamydia trachomatis es una de las infecciones de transmisión sexual más comunes en la población menor de 25 años, causante de graves problemas para la salud pública y la calidad de vida de las personas. Objetivo: Describir el conocimiento y creencias en la población joven entre 15 y 25 años, en relación a la infección por Clamidia, enmarcado en el contexto chileno e internacional. Métodos: Revisión narrativa que incluye 14 artículos cualitativos y cuantitativos de los últimos 10 años, en idioma inglés y español. Resultados: Existe desconocimiento sobre la infección por Clamidia, en cuanto a las características clínicas, el medio de transmisión y las pruebas diagnósticas, lo que genera que la población joven subestime el riesgo percibido y aumente conductas sexuales riesgosas. Por otro lado, se observa que el conocimiento aumenta de forma proporcional a la edad de la población, nivel educacional e historia previa de ITS. Conclusión: El déficit de conocimientos frente a las conductas sexuales de riesgo en la población joven favorece a un aumento en la prevalencia la infección por Clamidia, por lo cual es de suma importancia realizar nuevos estudios con el fin de aportar datos para potenciar programas de salud orientados a la concientización de los jóvenes frente a esta infección para así lograr disminuir la incidencia de esta enfermedad y sus complicaciones.

SUMMARY Introduction: Chlamydia trachomatis is one of the most common sexually transmitted infections in the population under 25 years old, causing serious problems for public health and the people's quality of life. Objective: Describe the knowledge and beliefs in the young population between 15 and 25 years old, related to Chlamydia infection in the Chilean and international context. Methods: Narrative review that includes qualitative and quantitative articles of the last 10 years, published in English and Spanish. Results: There is a lack of knowledge about Chlamydia infection, in the clinical characteristics, the transmission, and in the diagnostic tests, which causes the young population to underestimate the perceived risk and increase risky sexual behaviors. On the other hand, it is observed that knowledge increases proportionally to the population's age, educational level, and previous history of STIs. Conclusion: The lack of knowledge about risky sexual behavior in young population increase the prevalence of Chlamydia infection, due to this generates risky behaviors in the population, due to this, it is very important to conduct new studies in order to provide data to promote health programs oriented to raising awareness of young people against this infection and thus achieve to reduce the incidence of this disease and complications.

Partial nitrification enhances natural attenuation of nitrogen in a septic system plume.

Natural attenuation of nitrogen (N) was investigated in a well characterized septic system plume at a campground in Ontario, Canada. Total inorganic N (TIN) concentrations in deeper portions of the plume were about one third of the septic tank value of 40.7mgL-1. NH4+ and NO3- isotopic characterization were used to provide insight into potential attenuation processes. Concentrations of NH4+ and NO3- were highly variable in the plume, but approached the septic tank TIN value in some shallow zones and exhibited δ15N values like the tank value of +6‰. However, isotopic enrichment (up to +24‰ for NH4+ and +45‰ for NO3-) and declining TIN concentrations in the deeper zones indicated that anaerobic ammonium oxidation contributed to the TIN attenuation. The degree of isotopic enrichment increased at lower NH4+ concentrations and was consistent with Rayleigh-type distillation with an enrichment factor (Ɛ) of -5.1‰. Additionally, decreasing DOC values with depth and the concomitant enrichment of δ15NNO3 and δ18ONO3, suggested that denitrification was also active. The N attenuation observed in the Killarney plume was partly due to incomplete nitrification that occurred because of the shallow water table, which varied from only 0.2-0.7m below the tile bed infiltration pipes. Moreover, some of the monitoring locations with the shallowest water table distances from the infiltration pipes, had the highest degree of TIN attenuation (70-90%) in the plume. This behavior suggests that controlling water table distance from the infiltration pipes could be a useful mechanism for enhancing N attenuation in septic system plumes.

Distinct Dual C-Cl Isotope Fractionation Patterns during Anaerobic Biodegradation of 1,2-Dichloroethane: Potential To Characterize Microbial Degradation in the Field.

This study investigates, for the first time, dual C-Cl isotope fractionation during anaerobic biodegradation of 1,2-dichloroethane (1,2-DCA) via dihaloelimination by Dehalococcoides and Dehalogenimonas-containing enrichment cultures. Isotopic fractionation of 1,2-DCA (εbulkC and εbulkCl) for Dehalococcoides (-33.0 ± 0.4‰ and -5.1 ± 0.1‰) and Dehalogenimonas-containing microcosms (-23 ± 2‰ and -12.0 ± 0.8‰) resulted in distinctly different dual element C-Cl isotope correlations (Λ = Δδ13C/Δδ37Cl ≈ εbulkC/εbulkCl), 6.8 ± 0.2 and 1.89 ± 0.02, respectively. Determined isotope effects and detected products suggest that the difference on the obtained Λ values for biodihaloelimination could be associated with a different mode of concerted bond cleavage rather than two different reaction pathways (i.e., stepwise vs concerted). Λ values of 1,2-DCA were, for the first time, determined in two field sites under reducing conditions (2.1 ± 0.1 and 2.2 ± 2.9). They were similar to the one obtained for the Dehalogenimonas-containing microcosms (1.89 ± 0.02) and very different from those reported for aerobic degradation pathways in a previous laboratory study (7.6 ± 0.1 and 0.78 ± 0.03). Thus, this study illustrates the potential of a dual isotope analysis to differentiate between aerobic and anaerobic biodegradation pathways of 1,2-DCA in the field and suggests that this approach might also be used to characterize dihaloelimination of 1,2-DCA by different bacteria, which needs to be confirmed in future studies.

Thermodynamic and hydrochemical controls on CH4 in a coal seam gas and overlying alluvial aquifer: new insights into CH4 origins.

Using a comprehensive data set (dissolved CH4, δ(13)C-CH4, δ(2)H-CH4, δ(13)C-DIC, δ(37)Cl, δ(2)H-H2O, δ(18)O-H2O, Na, K, Ca, Mg, HCO3, Cl, Br, SO4, NO3 and DO), in combination with a novel application of isometric log ratios, this study describes hydrochemical and thermodynamic controls on dissolved CH4 from a coal seam gas reservoir and an alluvial aquifer in the Condamine catchment, eastern Surat/north-western Clarence-Moreton basins, Australia. δ(13)C-CH4 data in the gas reservoir (-58‰ to -49‰) and shallow coal measures underlying the alluvium (-80‰ to -65‰) are distinct. CO2 reduction is the dominant methanogenic pathway in all aquifers, and it is controlled by SO4 concentrations and competition for reactants such as H2. At isolated, brackish sites in the shallow coal measures and alluvium, highly depleted δ(2)H-CH4 (<310‰) indicate acetoclastic methanogenesis where SO4 concentrations inhibit CO2 reduction. Evidence of CH4 migration from the deep gas reservoir (200-500 m) to the shallow coal measures (<200 m) or the alluvium was not observed. The study demonstrates the importance of understanding CH4 at different depth profiles within and between aquifers. Further research, including culturing studies of microbial consortia, will improve our understanding of the occurrence of CH4 within and between aquifers in these basins.

Performance of different assessment methods to evaluate contaminant sources and fate in a coastal aquifer.

The present study deals with the application of different monitoring techniques and numerical models to characterize coastal aquifers affected by multiple sources of contamination. Specifically, equivalent freshwater heads in 243 monitoring wells were used to reconstruct the piezometric map of the studied aquifer; flow meter tests were carried out to infer vertical groundwater fluxes at selected wells; deuterium and oxygen isotopes were used to identify the groundwater origin, and tritium was analyzed to estimate the residence time; compound-specific isotope analyses and microbial analyses were employed to track different sources of contamination and their degradation; numerical modelling was used to estimate and verify groundwater flow direction and magnitude throughout the aquifer. The comparison of the information level for each technique allowed determining which of the applied approaches showed the best results to locate the possible sources and better understanding of the fate of the contaminants. This study reports a detailed site characterization process and outcomes for a coastal industrial site, where a comprehensive conceptual model of pollution and seawater intrusion has been built using different assessment methods. Information and results from this study encourages combining different methods for the design and implementation of the monitoring activities in real-life coastal contaminated sites in order to develop an appropriate strategy for control and remediation of the contamination.

Multiple lines of evidence to demonstrate vinyl chloride aerobic biodegradation in the vadose zone, and factors controlling rates.

A field-based investigation was conducted at a contaminated site where the vadose zone was contaminated with a range of chlorinated hydrocarbons. The investigation consisted of groundwater and multilevel soil-gas monitoring of a range of contaminants and gases, along with isotope measurements and microbiology studies. The investigation provided multiple lines of evidence that demonstrated aerobic biodegradation of vinyl chloride (VC) was occurring in the vadose zone (i) above the on-site source zone, and (ii) above the downgradient off-site groundwater plume location. Data from both the on-site and off-site locations were consistent in showing substantially greater (an order of magnitude greater) rates of VC removal from the aerobic vadose zone compared to more recalcitrant contaminants trichloroethene (TCE) and tetrachloroethene (PCE). Soil gas VC isotope analysis showed substantial isotopic enrichment of VC (δ¹³C -5.2 to -10.9‰) compared to groundwater (δ¹³C -39.5‰) at the on-site location. Soil gas CO2 isotope analysis at both locations showed that CO2 was highly isotopically depleted (δ¹³C -28.8 to -33.3‰), compared to soil gas CO2 data originating from natural sediment organic matter (δ¹³C= -14.7 to -21.3‰). The soil gas CO2 δ¹³C values were consistent with near-water table VC groundwater δ¹³C values (-36.8 to -39.5‰), suggesting CO2 originating from aerobic biodegradation of VC. Bacteria that had functional genes (ethene monooxygenase (etnC) and epoxyalkane transferase (etnE)) involved in ethene metabolism and VC oxidation were more abundant at the source zone where oxygen co-existed with VC. The distribution of VC and oxygen vadose zone vapour plumes, together with long-term changes in soil gas CO2 concentrations and temperature, provided information to elucidate the factors controlling aerobic biodegradation of VC in the vadose zone. Based on the overlapping VC and oxygen vadose zone vapour plumes, aerobic vapour biodegradation rates were independent of substrate (VC and/or oxygen) concentration. The high correlation (R=0.962 to 0.975) between CO2 concentrations and temperature suggested that aerobic biodegradation of VC was controlled by bacterial activity that was regulated by the temperature within the vadose zone. When assessing a contaminated site for possible vapour intrusion into buildings, accounting for environmental conditions for aerobic biodegradation of VC in the vadose zone should improve the assessment of environmental risk of VC intrusion into buildings, enabling better identification and prioritisation of contaminated sites to be remediated.

Determinación de la dimensión vertical oclusal en desdentados totales: comparación de métodos convencionales con el craneómetro de Knebelman / Determination of oclusal vertical dimension in edentulous: comparison of conventional methods with Knebelman craneometer

Objetivo: Se realizó una investigación cuyo propósito fue comparar la DVO determinada mediante métodos convencionales y la determinada por el craneómetro de Knebelman en el mismo paciente. Método: Se consideró como metodología convencional la DVO medida estando el paciente con sus prótesis en máxima intercuspidación. El estudio se realizo en una muestra de 45 individuos desdentados totales y parciales sin referencia oclusiva, rehabilitados con prótesis removible en la en la Clínica Integral del Adulto I y II. Los resultados fueron analizados empleando el test t pareado expresado en mm. de la DVO determinada con cada metodología. Resultado: Se encontraron diferencias significativas entre ambas mediciones y se empleó el test Chi-Cuadrado para analizar la influencia en la magnitud de la DVO observada cuando se emplea una o más referencias en su determinación, donde no se encontraron diferencias significativas. El rango de diferencias entre ambas metodologías de determinación en promedio fue de 2.93 mm considerado no relevante desde el punto de vista clínico. Conclusión: En este contexto el craneómetro de Knebelman puede ser un valioso instrumento que permita simplificar la determinación de la DVO en pacientes desdentados.

Objective: The purpose of this investigation was to compare the OVD obtained with the conventional methods and the one that is obtained with the Knebelman craniometric system in the same patient. Methods: The OVD considered as "conventional" was the one obtained with the patient using his/her dental prosthesis in maximum intercuspidation. This study was made using a sample of 45 edentulous and partially edentulous subjects, all treated with full removable denture and RPD in "Odontologia Integral del Adulto I & II". The results were analyzed using pair comparison system for the different OVD obtained with both methods (all expressed in millimeters). Results: Significant differences were found between both methods. The Chi-Square test to analyze de influence in the OVD when one or more references are used, didn´t show any significant differences. The average discrepancy between the two methods was 2.93 mm, which is considered as not clinically significant. Conclusion: In this context the Knebelman craneometer can be considered as an important instrument to simplify the determination of the OVD in edentulous patients.

Natural attenuation of septic system nitrogen by anammox.

On-site disposal of sewage in septic systems can lead to groundwater plumes with NO(3)(-)-N concentrations exceeding the common drinking water limit of 10 mg/L. Currently, denitrification is considered as the principal natural attenuation process. However, at a large seasonal-use septic system in Ontario (256 campsites), a suboxic zone exists where nitrogen removal of up to 80% occurs including removal of NH(4)(+)-N. This zone has both NO(3)(-)-N and NH(4)(+)-N at >5 mg/L each. In the distal NH(4)(+)-rich zone, NH(4)(+)-N concentrations (8.1 ± 8.0 mg/L) are lower than in the proximal zone (48 ± 36 mg/L) and NH(4)(+)-N is isotopically enriched (concentration-weighted mean δ(15)N of +15.7‰) compared to the proximal zone (+7.8‰). Furthermore, δ(15)N-NH(4)(+) isotopic enrichment increases with depth in the distal zone, which is opposite to what would result if nitrification along the water table zone was the mechanism causing NH(4)(+) depletion. Bacterial community composition was assessed with molecular (DNA-based) analysis and demonstrated that groundwater bacterial populations were predominantly composed of bacteria from two Candidatus genera of the Planctomycetales (Brocadia and Jettenia). Together, these data provide strong evidence that anaerobic ammonium oxidation (anammox) plays an important role in nitrogen attenuation at this site.

[Acquired hemophilia A treated with rituximab. Report of one case]. / Hemofilia adquirida tratada con anti CD20, un anticuerpo anti linfocito B.

We report a 54-year-old male presenting with a history or recurrent nose bleeds and ecchymoses. The coagulation study showed a prolonged partial thromboplastin time, a factor VIII of 8% and a high inhibitor titer (193 Bethesda units). A diagnosis of acquired hemophilia A was reached. The patient was initially treated with cyclophosphamide for seven months without response. Therefore rituximab in doses of 375 mglm²/week for four weeks was started. After starting treatment, the patient had a hematoma in the psoas muscle with a concomitant factor VIII of less than 5%, that was treated with local measures. Thereafter, a progressive reduction in inhibitor titers was observed, until its disappearance at five months of treatment. Factor VIII levels normalized and the patient has not experienced abnormal bleeding episodes. The patient remains in remission after 67 months of follow up. Rituximab, a chimeric monoclonal antibody against the protein CD 20 is an effective treatment in acquired hemophilia A.

Hemofilia adquirida tratada con anti CD20, un anticuerpo anti linfocito B / Acquired hemophilia a treated with rituximab. Report of one case

We report a 54-year-old male presenting with a history or recurrent nose bleeds and ecchymoses. The coagulation study showed a prolongedpartial thromboplastin time, a factor VIII of 8 percent and a high inhibitor titer (193 Bethesda units). A diagnosis of acquired hemophilia A was reached. The patient was initially treated with cyclophosphamide for seven months without response. Therefore rituximab in doses of 375 mglm²Iweek for four weeks was started. After starting treatment, the patient had a hematoma in the psoas muscle with a concomitantfactor VIII ofless than 5 percent, thatwas treated with local measures. Thereafter, aprogressive reduction in inhibitor titers was observed, until its disappearance atfive months of treatment. Factor VIII levéis normalized and the patient has not experienced abnormal bleeding episodes. The patient remains in remission after 67 months offollow up. Rituximab, a chimeric monoclonal antibody against theprotein CD 20 is an effective treatment in acquired hemophilia A.

Adaptación del sistema espiga muñón en relación a la preparación del conducto / Fit of the cast post and core system with different canal preparations

Se realizó un estudio in vitro que tuvo por objetivo medir el grado de adaptación del sistema espiga muñón, debido a que es uno de los factores fundamentales para lograr un buen anclaje de estos artificios, medido a nivel del núcleo de éste con respecto a los planos radiculares y de la espiga a las paredes del conducto, cuando es conformado con fresas Peeso y cuando es conformado usando fresas Peeso terminando con fresas del sistema Mooser. Seleccionamos 40 dientes que se dividieron al azar en dos grupos de 20, denominados P y M, respectivamente. Se confeccionó en cada muestra, previamente tratado su conducto mediante método indirecto, un perno muñón colado que fue probado en la preparación donde se midió el ajuste del muñón propiamente tal, después de logrado el asentamiento adecuado mediante desgastes en las interferencias de la espiga fueron cementados, posteriormente se realizaron dos cortes transversales a todo el espesor de la raíz a diferentes alturas, donde se midió la interfase entre la espiga y las paredes del conducto (adaptación). Los resultados fueron analizados utilizando los test de Mann-Whitney, Tukey y test T pareado, con software Systat versión 11, encontrándose que la mejor adaptación se observa en las muestras del grupo M en los dos sitios observados, comparadas con las del grupo P Estas diferencias son estadísticamente significativas.

We carried out a research aimed to determine the adaptation of the system called cast post and core, because it's one of the main factors to achieve a good adaptation of these devices measured from the core of this device to radicular plan, and from the post to the canal protesic's surface, when this one was prepared with Peeso's burs, and when was also prepared starting with Peeso's burs but finishing with Mooser system's burs. For that objective, we selected 40 teeth that were divided randomly into two groups of 20, called P and M respectively. A cast post and core was made in each sample through indirect method, previously treated the protesic canal. The cast post and core was tested in the preparation where the fit of the core was measured. Once achieved the proper settlement through the wearing out of the post's interferences and once the cast post and core was cemented, we made two cross cuttings to the thickness of the root at two differents levels, where the interface between the post and canal protesic's surface was measured (adaptation). The results were analyzed using the Mann-Whithny test, Tukey and paired T test, with Systast software version 11, having found that the best adaptation was observed in the samples of group M at the two points analyzed, compared to group P. These differences are statistically significant.

Carbon and chlorine isotope fractionation during aerobic oxidation and reductive dechlorination of vinyl chloride and cis-1,2-dichloroethene.

The study investigated carbon and chlorine isotope fractionation during aerobic oxidation and reductive dechlorination of vinyl chloride (VC) and cis-1,2-dichloroethene (cDCE). The experimental data followed a Rayleigh trend. For aerobic oxidation, the average carbon isotope enrichment factors were -7.2 per thousand and -8.5% for VC and cDCE, respectively, while average chlorine isotope enrichment factors were only -0.3 per thousand for both compounds. These values are consistent with an initial transformation by epoxidation for which a significant primary carbon isotope effect and only a small secondary chlorine isotope effect is expected. For reductive dechlorination, larger carbon isotope enrichment factors of -25.2 per thousand for VC and -18.5 per thousand for cDCE were observed consistent with previous studies. Although the average chlorine isotope enrichmentfactors were larger than those of aerobic oxidation (-1.8 per thousand for VC, -1.5 per thousand for cDCE), they were not as large as typically expected for a primary chlorine isotope effect suggesting that no cleavage of C-Cl bonds takes place during the initial rate-limiting step. The ratio of isotope enrichment factors for chlorine and carbon were substantially different for the two reaction mechanisms suggesting that the reaction mechanisms can be differentiated at the field scale using a dual isotope approach.

Compound-specific carbon isotope analysis of volatile organic compounds in water using solid-phase microextraction.

The compound-specific isotope analysis technique in conjunction with solid-phase microextraction using a carboxen-polydimethylsiloxane fiber was tested and implemented for isotopes analyses of organic compounds aiming for environmental application in contaminated groundwater. delta(13)C values of several chlorinated methanes and ethenes, toluene and chlorobenzene were determined using a gas chromatograph coupled to an isotope ratio mass spectrometer through a combustion interface. Direct and headspace solid-phase microextraction (D-SPME, HS-SPME) methods were tested in order to determine the optimum conditions to obtain reproducible delta(13)C values at very low concentration (microg/L range) and, to elucidate the carbon isotopic effects associated with the competitive extraction. For D-SPME, higher accuracy and precision of delta(13)C results were obtained with no salted aqueous standards. Despite that the delta(13)C of those compounds analyzed with both methods showed similar precision (<0.5 per thousand) and accuracy, the highest sensitivity was reached with HS-SPME. Furthermore, the delta(13)C values of cis-1,2-dichloroethylene, chorinated methanes and aromatic compounds obtained using HS-SPME showed measurable deviations with respect to the isotopic composition of pure phase compounds, however, these deviations are constant according to the analytical uncertainties, indicating that they are not affected by competitive extraction, and they could be corrected using standard correction technique based on internal calibrated standards.

Isotopic composition as a tool for assessment of origin and dynamic of organic matter in tropical freshwater.

The isotopic composition (13C and 15N) and C:N ratio of sediment and particulate were investigated to assess the origin and dynamic of the organic matter in two river basins located in the Parana State, Brazil. The main sources of organic matter, plants, litter and soil, were analyzed in the study. This study was carried out during the dry and wet seasons. Although organic matter contribution for the particulate material has been mixed, the main contribution in the two seasons for both rivers was autochthonous characterized by delta13C and C:N ratio values ranging from -31.0 to -21.8 per thousand and from 5.1 to 11.4, respectively. The soil with delta13C values ranging from -25.9 to -20.6 per thousand, and C:N ratio from 10.2 to 15.8, was the main carbon source for the river sediment for the two tributaries in the wet and dry seasons. The sediment delta15N values for both the rivers in the wet season showed an 15N enrichment trend in most of studied sites when compared to the dry season values, suggesting major input of nutrients as dissolved organic nitrogen and sewage nitrate. In the dry season, 14N enriched compounds, could have been used by phytoplankton, causing 15N enrichment. The isotope and C:N ratio data clearly showed that the agricultural activity has been influencing the origin and dynamic of organic matter in the two rivers, with potential biochemical consequences for the lower basin of the major Tibagi river.

Autotrasplante (AT) de progenitores hematopoyéticos en mieloma múltiple: Experiencia clínica / Autologous transplant (AT) with peripheral-blood stem-cell rescue for multiple myeloma: A clinical experience

Background:Multiple myeloma is rarely curable. Advances in high dose chemotherapy and stem cell transplantation have improved overall survival and event-free disease periods, but relapses are inevitable. Aim: To report our experience with AT in multiple myeloma, between 1994 and 2003. Material and Methods: Retrospective analysis of 20 patients (12 women), with a mean age of 51.1 years. VAD (vincristine, doxorubicin and dexamethasone) was used as initial therapy in 19 patients. High dose cyclophosphamide (11 patients) and variations of VAD regimen (7) associated with granulocyte colony stimulating factor were used for peripheral-blood stem cell harvest. The conditioning regimen consisted of melphalan 200 mg/m2 followed by the reinfusion of peripheral-blood stem cells 24 hours later. The median number of CD34 cells infused was 3,3x106/kg. Three patients were subjected to a second auto graft and one to a non-myeloablative transplant. Mean follow up was 35.5 months. Results: Mucositis and febrile neutropenia were common complications. The median number of days for neutrophyl engraftment was 9 (range 8-11) and for platelets, 10 (range 7-13). No patient died. Complete remission was obtained in 60% (12/20), progession-free survival was 30 months and overall median survival, 47 months. Conclusions: The AT with high-dose melphalan is a safe procedure in our hospital, without mortality and engraftment in all the patients. Complete remission and progression free survival were similar to those reported abroad but the overall median survival was lower.

Effect of source variability and transport processes on carbon isotope ratios of TCE and PCE in two sandy aquifers.

Chlorinated ethenes often migrate over extended distances in aquifers and may originate from different sources. The aim of this study was to determine whether stable carbon isotope ratios remain constant during dissolution and transport of chlorinated ethenes and whether the ratios can be used to link plumes to their sources. Detailed depth-discrete delineation of the carbon isotope ratio in a tetrachloroethene (PCE) plume and in a trichloroethene (TCE) plume was done along cross-sections orthogonal to groundwater flow in two sandy aquifers in the Province of Ontario, Canada. At the TCE site, TCE concentrations up to solubility were measured in one high concentration zone close to the bottom of the aquifer from where dense non-aqueous phase liquid (DNAPL) was collected. A laboratory experiment using the DNAPL indicated that only very small carbon isotope fractionation occurs during dissolution of TCE (0.26 per thousand), which is consistent with field observations. At most sampling points, the delta(13)C of dissolved TCE was similar to that of the DNAPL except for a few sampling points at the bottom of the aquifer close to the underlying aquitard. At these points, a (13)C enrichment of up to 2.4 per thousand was observed, which was likely due to biodegradation and possibly preferential diffusion of TCE with (12)C into the aquitard. In contrast to the TCE site, several distinct zones of high concentration were observed at the PCE site and from zones to zone, the delta(13)C values varied substantially from -24.3 per thousand to -33.6 per thousand. Comparison of the delta(13)C values in the high concentration zones made it possible to divide the plume in the three different domains, each probably representing a different episode and location of DNAPL release. The three different zones could still be distinguished 220 m from the DNAPL sources. This demonstrates that carbon isotope ratios can be used to differentiate between different zones in chlorinated ethene plumes and to link plume zones to their sources. In addition, subtle variations in delta(13)C at plume fringes provided insight into mechanisms of plume spreading in transverse vertical direction. These variations were identified because of the high-resolution provided by the monitoring network.

Carbon isotopes as a tool to evaluate the origin and fate of vinyl chloride: laboratory experiments and modeling of isotope evolution.

Accumulation of vinyl chloride (VC) is often a main concern at sites contaminated with chlorinated ethenes and ethanes due to its high toxicity. Since there can be several possible sources of VC and ethene at such sites, assessing the origin and fate of VC can be complicated. Aim of this study was to evaluate carbon isotope fractionation associated with various anaerobic processes that lead to the production of VC and ethene in view of using isotopes to evaluate the origin and fate of these compounds in groundwater. Microcosms were constructed using sediments and groundwater from a contaminated site and amended with potential precursors for VC and ethene production. In the microcosms with dichloroethene isomers, sequential reductive dechlorination was observed, and isotopic enrichmentfactors of -19.9 +/- 1.5 per thousand for cis-1,2-dichloroethene, -30.3 +/- 1.9 per thousand for trans-1,2-dichloroethene, and -7.3 +/- 0.4 per thousand for 1,1-dichloroethene were obtained. In microcosms with chlorinated ethanes, 1,2-dichloroethane (1,2-DCA) and 1,1,2-trichloroethane (1,1,2-TCA) were predominantly transformed by dichloroelimination to ethene and VC, respectively, and enrichmentfactors of -32.1 +/- 1.1 per thousand for 1,2OCA and -2.0 +/- 0.2 per thousand for 1,1,2-TCA were observed. Except for 1,1,2-TCA, a strong 13C enrichment in each of the potential precursor of VC was observed, which opens the possibility to trace the origin of VC based on the isotope ratio of potential precursors. Furthermore, it was possible to model the isotope evolution of VC present as substrate or intermediate product as a function of time. The study demonstrates that carbon isotope ratios can potentially be used for qualitative and possibly quantitative evaluation of the origin and fate of VC at sites with complex contaminant mixtures.

Hydrogen and carbon isotope fractionation during aerobic biodegradation of benzene.

The main aim of the study was to evaluate hydrogen and carbon isotope fractionation during biodegradation of benzene as a possible tool to trace the process in contaminated environments. Aerobic biodegradation of benzene by two bacterial isolates, Acinetobacter sp. and Burkholderia sp., was accompanied by significant hydrogen and carbon isotope fractionation with hydrogen isotope enrichment factors of -12.8 +/- 0.7 per thousand and -11.2 +/- 1.8 per thousand, respectively, and average carbon isotope enrichment factors of -1.46 +/- 0.06 per thousand and -3.53 +/- 0.26 per thousand, respectively. Inorganic carbon produced by Acinetobacter sp. was depleted in 13C by 3.6-6.2 per thousand as compared to the initial delta13C of benzene, while the produced biomass was enriched in 13C by 3.8 per thousand. The secondary aim was to determine isotope ratios of benzenes from different manufacturers with regard to the use of isotopes for source differentiation. While two of the four analyzed benzenes had similar delta13C values, each of them had a distinct delta2H-delta13C pair and delta2H values spread over a range of 66.5 per thousand. Thus, combined analyses of hydrogen and carbon isotopes may be a more promising approach to trace sources and/or biodegradation of benzene than measuring carbon isotopes only.