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PURPOSE: The main challenges in revision total hip arthroplasty (rTHA) are the treatment of the bone loss and the pre-operative planning. 3D-printed models may enhance pre-operative planning. The aim of the study is to compare the intra- and peri-operative results and costs for Paprosky type 3 rTHAs planned with 3D-printed models to ones accomplished with the conventional imaging techniques (X-rays and CT scan). METHODS: Seventy-two patients with Paprosky type 3 defect underwent rTHA between 2014 and 2021. Fifty-two patients were treated with standard planning and 20 were planned on 3D-printed models. Surgical time, intra-operative blood loss, number of transfused blood units, number of post-operative days of hospitalization, and use of acetabular rings were compared between the two groups. A costs comparison was also performed. RESULTS: The 3D-printed group showed reduced operative time (101.8 min (SD 27.7) vs. 146.1 min (SD 49.5), p < 0.001) and total days of hospitalization (9.3 days (SD 3.01) vs. 12.3 days (SD 6.01), p = 0.009). The cost of the procedures was significantly lower than the control group, with an adjusted difference of 4183 euros (p = 0.004). No significant differences were found for the number of total transfused blood units and blood loss and the number of acetabular rings. CONCLUSION: The use of 3D-printed models led to a meaningful cost saving. The 3D-printed pre-operative planning for complex rTHAs seems to be effective in reducing operating time, hospital stay and overall costs.
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Artroplastia de Reemplazo de Cadera , Prótesis de Cadera , Humanos , Artroplastia de Reemplazo de Cadera/efectos adversos , Radiografía , Tomografía Computarizada por Rayos X , Acetábulo/diagnóstico por imagen , Acetábulo/cirugía , Reoperación , Estudios de Casos y Controles , Impresión Tridimensional , Estudios RetrospectivosRESUMEN
BACKGROUND AND PURPOSE: The aim was to identify the clinical and diagnostic investigations that may help to support a diagnosis of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) in patients not fulfilling the European Federation of Neurological Societies and Peripheral Nerve Society (EFNS/PNS) electrodiagnostic criteria. METHODS: The data from patients with a clinical diagnosis of CIDP included in a national database were retrospectively reviewed. RESULTS: In all, 535 patients with a diagnosis of CIDP were included. This diagnosis fulfilled the EFNS/PNS criteria in 468 patients (87.2%) (definite in 430, probable in 33, possible in three, while two had chronic immune sensory polyradiculopathy). Sixty-seven patients had a medical history and clinical signs compatible with CIDP but electrodiagnostic studies did not fulfill the EFNS/PNS criteria for CIDP. These patients had similar clinical features and frequency of abnormal supportive criteria for the diagnosis of CIDP compared to patients fulfilling EFNS/PNS criteria. Two or more abnormal supportive criteria were present in 40 (61.2%) patients rising to 54 (80.6%) if a history of a relapsing course as a possible supportive criterion was also included. Increased cerebrospinal fluid proteins and response to immune therapy most frequently helped in supporting the diagnosis of CIDP. Response to therapy was similarly frequent in patients fulfilling or not EFNS/PNS criteria (87.3% vs. 85.9%). CONCLUSIONS: Patients with a clinical diagnosis of CIDP had similar clinical findings, frequency of abnormal supportive criteria and response to therapy compared to patients fulfilling EFNS/PNS criteria. The presence of abnormal supportive criteria may help in supporting the diagnosis of CIDP in patients with a medical history and clinical signs compatible with this diagnosis but non-diagnostic nerve conduction studies.
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Polirradiculoneuropatía Crónica Inflamatoria Desmielinizante , Bases de Datos Factuales , Humanos , Conducción Nerviosa , Nervios Periféricos , Polirradiculoneuropatía Crónica Inflamatoria Desmielinizante/diagnóstico , Estudios RetrospectivosRESUMEN
BACKGROUND AND PURPOSE: The role of lifestyle and dietary habits and antecedent events has not been clearly identified in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). METHODS: Information was collected about modifiable environmental factors and antecedent infections and vaccinations in patients with CIDP included in an Italian CIDP Database. Only patients who reported not having changed their diet or the lifestyle habits investigated in the study after the appearance of CIDP were included. The partners of patients with CIDP were chosen as controls. Gender-matched analysis was performed with randomly selected controls with a 1:1 ratio of patients and controls. RESULTS: Dietary and lifestyle data of 323 patients and 266 controls were available. A total of 195 cases and 195 sex-matched controls were used in the analysis. Patients eating rice at least three times per week or eating fish at least once per week appeared to be at decreased risk of acquiring CIDP. Data on antecedent events were collected in 411 patients. Antecedent events within 1-42 days before CIDP onset were reported by 15.5% of the patients, including infections in 12% and vaccinations in 1.5%. Patients with CIDP and antecedent infections more often had an acute onset of CIDP and cranial nerve involvement than those without these antecedent events. CONCLUSIONS: The results of this preliminary study seem to indicate that some dietary habits may influence the risk of CIDP and that antecedent infections may have an impact on the onset and clinical presentation of the disease.
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Conducta Alimentaria , Estilo de Vida , Polirradiculoneuropatía Crónica Inflamatoria Desmielinizante/epidemiología , Adulto , Niño , Bases de Datos Factuales , Femenino , Humanos , Infecciones/complicaciones , Italia/epidemiología , Masculino , Persona de Mediana Edad , Factores de RiesgoRESUMEN
Colloidal suspensions of oxocarbon-encapsulated gold nanoparticles have been synthesized in a one-step procedure by pulsed-laser ablation (PLA) at 532 nm of a solid gold target placed in aqueous solution containing CO2 absorbers, but without any stabilizing agent. Multi-wavelength surface enhanced Raman spectroscopy allows the identification of adsorbed amorphous carbon and graphite, Au-carbonyl, Au coordinated CO2-derived bicarbonates/carbonates and hydroxyl groups around the AuNPs core. Scanning electron microscopy, energy dispersive x-ray analysis and high resolution transmission electron microscopy highlight the organic shell structure around the crystalline metal core. The stability of the colloidal solution of nanocomposites (NCs) seems to be driven by solvation forces and is achieved only in neutral or basic pH using monovalent hydroxide counter-ions (NaOH, KOH). The NCs are characterized by a blue shift of the localized surface plasmon resonance (LSPR) band typical of metal-ligand stabilization by terminal π-back bonding, attributed to a core charging effect caused by Au-carbonyls. Total organic carbon measurements detect the final content of organic carbon in the colloidal solution of NCs that is about six times higher than the value of the water solution used to perform PLA. The colloidal dispersions of NCs are stable for months and are applied as analytical probes in amino glycoside antibiotic LSPR based sensing.
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BACKGROUND: Current cancer mortality statistics are important for public health decision-making and resource allocation. Age-standardized rates and numbers of deaths are predicted for 2016 in the European Union (EU). PATIENTS AND METHODS: Population and death certification data for stomach, colorectum, pancreas, lung, breast, uterus, prostate, leukaemias and total cancers were obtained from the World Health Organization database and Eurostat. Figures were derived for the EU, France, Germany, Italy, Poland, Spain and the UK. Projected numbers of deaths by age group were obtained for 2016 by linear regression on estimated numbers of deaths over the most recent time period identified by a joinpoint regression model. RESULTS: Projected total cancer mortality trends for 2016 in the EU are favourable in both sexes with rates of 133.5/100 000 men and 85.2/100 000 women (8% and 3% falls since 2011) corresponding to 753 600 and 605 900 deaths in men and women for a total number of 1 359 500 projected cancer deaths (+3% compared with 2011, due to population ageing). In men, lung, colorectal and prostate cancer have fallen 11%, 5% and 8%, respectively, since 2011. Breast and colorectal cancer trends in women are favourable (8% and 7% falls, respectively), but lung and pancreatic cancer rates have risen 5% and 4% since 2011 reaching rates of 14.4 and 5.6/100 000 women. Leukaemias show favourable projected mortality for both sexes and all age groups, with stronger falls in the younger age groups. All ages rates are 4.0/100 000 men and 2.5/100 000 women, with falls of 14% and 12% respectively. CONCLUSION: The 2016 predictions for EU cancer mortality confirm the favourable trends in rates particularly for men. Lung cancer is likely to be the leading site for female cancer rates. Continuing falls in mortality, larger in children and young adults, are predicted in leukaemias, essentially due to advancements in management and therapy, and their subsequent adoption across Europe.
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Predicción , Leucemia/mortalidad , Pronóstico , Adulto , Factores de Edad , Anciano , Niño , Europa (Continente)/epidemiología , Femenino , Humanos , Leucemia/clasificación , Leucemia/patología , Masculino , Persona de Mediana EdadRESUMEN
BACKGROUND: Cancer mortality statistics for 2015 were projected from the most recent available data for the European Union (EU) and its six more populous countries. Prostate cancer was analysed in detail. PATIENTS AND METHODS: Population and death certification data from stomach, colorectum, pancreas, lung, breast, uterus, prostate, leukaemias and total cancers were obtained from the World Health Organisation database and Eurostat. Figures were derived for the EU, France, Germany, Italy, Poland, Spain and the UK. Projected 2015 numbers of deaths by age group were obtained by linear regression on estimated numbers of deaths over the most recent time period identified by a joinpoint regression model. RESULTS: A total of 1,359,100 cancer deaths are predicted in the EU in 2015 (766,200 men and 592,900 women), corresponding to standardised death rates of 138.4/100,000 men and 83.9/100,000 women, falling 7.5% and 6%, respectively, since 2009. In men, predicted rates for the three major cancers (lung, colorectum and prostate) are lower than in 2009, falling 9%, 5% and 12%. Prostate cancer showed predicted falls of 14%, 17% and 9% in the 35-64, 65-74 and 75+ age groups. In women, breast and colorectal cancers had favourable trends (-10% and -8%), but predicted lung cancer rates rise 9% to 14.24/100,000 becoming the cancer with the highest rate, reaching and possibly overtaking breast cancer rates--though the total number of deaths remain higher for breast (90 800) than lung (87 500). Pancreatic cancer has a negative outlook in both sexes, rising 4% in men and 5% in women between 2009 and 2015. CONCLUSIONS: Cancer mortality predictions for 2015 confirm the overall favourable cancer mortality trend in the EU, translating to an overall 26% fall in men since its peak in 1988, and 21% in women, and the avoidance of over 325,000 deaths in 2015 compared with the peak rate.
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Neoplasias Pulmonares/mortalidad , Mortalidad/tendencias , Neoplasias/mortalidad , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Unión Europea , Femenino , Estudios de Seguimiento , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Pronóstico , Tasa de Supervivencia , Factores de Tiempo , Salud de la Mujer , Adulto JovenRESUMEN
We demonstrate that Surface Plasmon Resonance spectroscopy can be used for the accurate and simultaneous determination of the thickness and refractive index of transparent thin thermally deposited organic films. The experimental approach is based on a two-metal deposition or a two-thickness method. These methods have been applied to an encapsulated sample containing a thin film of commercial tris(8-hydroxyquinoline) (Alq3). The accuracy of the measurement depends on the control of the film deposition process and suggests the use of SPR spectroscopy as inexpensive and valuable metrology tool for small molecule organic thin films.
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We describe the performance of a second-harmonic interferometer (SHI) to measure, on an optical path exceeding 12 m, the electron plasma density of two plasmoids formed in separate theta-pinch chambers and then merged in a central compression chamber after undergoing acceleration and compression. The excellent mechanical stability and a time resolution better than 50 ns suggest the application of SHI, especially in pulsed plasma devices with limited optical accesses.
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Second-harmonic interferometry (SHI) is proposed for measuring the electro-optic (EO) coefficients of massive media. It combines the advantages of interferometric techniques with the mechanical stability of single-beam methods, simultaneously skimming the wavelength dispersion of the EO response. For demonstrating the effectiveness of the SHI technique, the EO coefficients r(33)(T) and r(13)(T) of the EO crystal lithium niobate are measured simultaneously at 1064 and 532 nm.
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We studied the potentials of All Optical Switches (AOS) based on the intensity-dependent coupling and decoupling of light into the SPP modes (Surface Plasmon Polaritons) of a sinusoidally corrugated thin metal film (TMF), due to Kerr induced refractive index changes of the surrounding dielectrics. The ideal device has two spatially separated outputs, collecting the reflected and transmitted light and the active volume can be as small as 10(-2) mm(3). Gold and PTS (poly-(2,4-hexadiyne-1,6-diol bis(p-toluene sulfonate) are the materials considered. Losses are limited to 1.5 dB,while a 20 dB extinction ratio per gate has been theoretically demonstrated with signal pulsewidths of 5-10 ps , using a maximum optical switching peak power of 11 kW.
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Modelos Teóricos , Refractometría/instrumentación , Procesamiento de Señales Asistido por Computador/instrumentación , Resonancia por Plasmón de Superficie/instrumentación , Simulación por Computador , Diseño de Equipo , Análisis de Falla de Equipo , Luz , Dispersión de RadiaciónRESUMEN
Neurophysiological and neuroimaging studies suggest that pain may play a major role in determining cortical somatosensory rearrangements even in the adult brain. The re-organizational power of pain, however, has been tested in models in which massive deafferentation co-existed with pain (e.g. in phantom pain). Moreover, information on whether spinal and brainstem changes contribute to pain-related plasticity in humans is meagre. We used the non-invasive somatosensory evoked potentials technique in patients with right primary trigeminal neuralgia and no clinical signs of large-diameter fibers of trigeminal deafferentation to assess whether pain may induce plastic changes at multiple levels in the somatosensory system. Subcortical and cortical potentials evoked by stimulation of the right median and posterior tibial nerves ipsilateral to the facial pain were compared with those obtained following stimulation of the left median and tibial nerves and with those obtained in a control group tested in comparable conditions. Amplitudes of parietal N20 and P27 and frontal N30 potentials observed following stimulation of the right median nerve ipsilateral to the facial pain were greater than those of the left median nerve and showed a positive correlation with magnitude of pain. This right-left asymmetry was absent following stimulation of the patients' tibial nerves and in control subjects. No changes were found in spinal N13 and brainstem P14. That facial pain is associated with neuroplastic changes within the somatic cortical representation of the hand suggests a pain-related topographic cortical reorganisation.
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Potenciales Evocados Somatosensoriales , Cara/inervación , Mano/inervación , Plasticidad Neuronal/fisiología , Neuralgia del Trigémino/fisiopatología , Anciano , Mapeo Encefálico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Dolor/fisiopatología , Tacto/fisiologíaRESUMEN
Ten patients with idiopathic dystonia and twelve healthy controls were tested with pairs of non-noxious electrical stimuli separated by different time intervals. Stimuli were delivered (i) to the pad of the index finger (same-point condition), (ii) to the pad and to the base of the index finger (same-finger condition) and (iii) to the pad of the index and ring fingers (different-fingers condition). Subjects were asked to report if they perceived single or double stimuli in the first condition and synchronous or asynchronous stimuli in the second and third conditions. STDTs were significantly higher in dystonic than control subjects in all three conditions. Results extend current knowledge on deficits of somesthetic temporal discrimination in dystonia by showing that temporal deficits are not influenced by spatial variables.
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Distonía/fisiopatología , Trastornos de la Percepción/fisiopatología , Tacto , Adulto , Estudios de Casos y Controles , Discriminación en Psicología , Estimulación Eléctrica , Retroalimentación , Femenino , Dedos , Humanos , Masculino , Trastornos de la Percepción/etiología , Umbral Sensorial , Percepción del TiempoRESUMEN
Motor evoked potentials (MEPs) to transcranial magnetic stimulation (TMS) of the left motor cortex were recorded from the right first dorsal interosseous (FDI), abductor pollicis brevis (APB), abductor digiti minimi (ADM), flexor carpi radialis (FCR), extensor carpi radialis (ECR) in 17 normal subjects, before and after painful application of capsaicin on the skin overlying the right FDI and FCR muscles. The amplitude of MEPs from the FDI and FCR was significantly reduced from 20 to 30 min after the application of capsaicin over the FDI and FCR muscles, respectively, then progressively returned to the basal values. A similar trend of MEPs inhibition was observed for APB and FCR muscles, but this reduction was not significant. Indices of peripheral nerve (M-wave) and spinal cord excitability (F and H waves) did not change throughout the experiments. Motor cortex inhibition induced by tonic cutaneous pain is maximal to muscles adjacent to the painful area. This inhibition may be due to the activation of the C fibres which mediate 'slow' nociception and might be important to alert subject to possible phasic nociceptive events that may occur close to the painful area.
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Vías Aferentes/fisiología , Capsaicina/efectos adversos , Potenciales Evocados Motores/fisiología , Corteza Motora/fisiología , Inhibición Neural/fisiología , Nociceptores/fisiología , Dolor/fisiopatología , Adulto , Vías Aferentes/efectos de los fármacos , Vías Eferentes/efectos de los fármacos , Vías Eferentes/fisiología , Estimulación Eléctrica , Electromiografía , Potenciales Evocados Motores/efectos de los fármacos , Femenino , Lateralidad Funcional/fisiología , Humanos , Masculino , Contracción Muscular/efectos de los fármacos , Contracción Muscular/fisiología , Inhibición Neural/efectos de los fármacos , Vías Nerviosas/fisiología , Nociceptores/efectos de los fármacos , Dolor/inducido químicamente , Dimensión del Dolor , Piel/efectos de los fármacos , Piel/inervación , Corteza Somatosensorial/fisiología , Estimulación Magnética TranscranealRESUMEN
Studies suggest that pain may play a major role in determining cortical rearrangements in the adult human somatosensory system. Most studies, however, have been performed under conditions whereby pain coexists with massive deafferentation (e.g., amputations). Moreover, no information is available on whether spinal and brainstem changes contribute to pain-related reorganizational processes in humans. Here we assess the relationships between pain and plasticity by recording somatosensory-evoked potentials (SEPs) in patients who complained of pain to the right thumb after a right cervical monoradiculopathy caused by compression of the sixth cervical root, but did not present with clinical or neurophysiological signs of deafferentation. Subcortical and cortical potentials evoked by stimulation of digital nerves of the right thumb and middle finger were compared with those obtained after stimulation of the left thumb and middle finger and with those obtained in a control group tested in comparable conditions. Amplitudes of spinal N13, brainstem P14, parietal N20 and P27, and frontal N30 potentials after stimulation of the painful right thumb were greater than those of the nonpainful left thumb and showed a positive correlation with magnitude of pain. This right-left asymmetry was absent after stimulation of the patients' middle fingers and in control subjects. Results suggest that chronic cervical radicular pain is associated with changes in neural activity at multiple levels of the somatosensory system. The absence of correlation between the amplitude of spinal, brainstem, and cortical components of SEPs suggests that enhancement of cortical activity is not a simple amplification of subcortical enhancement.
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Potenciales Evocados Somatosensoriales , Dolor de Cuello/fisiopatología , Plasticidad Neuronal , Dimensión del Dolor , Radiculopatía/fisiopatología , Adulto , Tronco Encefálico/fisiopatología , Estimulación Eléctrica , Electromiografía , Femenino , Dedos/inervación , Lóbulo Frontal/fisiopatología , Humanos , Desplazamiento del Disco Intervertebral/complicaciones , Masculino , Persona de Mediana Edad , Dolor de Cuello/etiología , Examen Neurológico , Pruebas Neuropsicológicas , Lóbulo Parietal/fisiopatología , Radiculopatía/etiología , Reproducibilidad de los Resultados , Médula Espinal/fisiopatología , Pulgar/inervación , Pulgar/fisiopatologíaRESUMEN
Cell proliferation and death account for the refinement of the cell number during corticogenesis. These processes have been investigated in the human developing telencephalon (12th-24th week of gestation) and cerebellum (16th-24th week). Only foetal brains, which had normal neuropathological examination, were utilised. Cell proliferation was analysed by classical histology and PCNA immunohistochemistry; cell death was investigated by the TUNEL method, which makes evident the different stages of apoptosis. High figures of mitotic nuclei were seen in the ventricular zone at the 12th-15th week of gestation, before sharply declining. The decrease of the proliferating cells occurs synchronously in both frontal and occipital germinal zones. Conversely, a slow increase of the number of the mitotic cells was observed in the more dorsal regions, probably due to the presence of proliferating glial elements. The amount of apoptotic nuclei was always remarkably low in the transient compartments of the wall of the telencephalon. The moderate number of apoptotic cells suggests that cellular mechanisms other than apoptosis are involved in the dissolution of the ventricular zone. Neither proliferating nor apoptotic cells were seen in the cortical plate. The topography of cell proliferation and death in the developing cerebellum did not account for a mutual relationship between the two events. The prolonged duration of the cell-cycle in the human developing CNS may explain its increased vulnerability to various DNA-damaging conditions, which can lead to either destructive lesions or malformations.
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Muerte Celular/fisiología , Corteza Cerebelosa/patología , Telencéfalo/patología , División Celular/fisiología , Corteza Cerebelosa/metabolismo , Desarrollo Embrionario y Fetal/fisiología , Edad Gestacional , Humanos , Etiquetado Corte-Fin in Situ , Telencéfalo/embriologíaRESUMEN
Vesication and skin irritation studies were conducted in hairless guinea-pigs to determine the vesicant and skin irritation potential of chemically-neutralized Chemical Agent Identification Sets (CAIS). The CAIS are training items that contain chemical warfare-related material--sulfur mustard (HD), nitrogen mustard (HN) or lewisite (L)--and were declared obsolete in 1971. Animals were dosed topically with 'test article'--neat HD, 10% agent/chloroform solutions or product solutions (waste-streams) from neutralized CAIS--and evaluated for skin-damaging effects (gross and microscopic). Product solutions from the chemical neutralization of neat sulfur mustard resulted in microvesicle formation. All agent-dosed (HD or agent/chloroform solutions) sites manifested microblisters as well as other histopathological lesions of the skin. Waste-streams from the neutralization of agent (agent/chloroform or agent/charcoal) were devoid of vesicant activity. Cutaneous effects (erythema and edema) were consistent with the skin-injurious activity associated with the neutralizing reagent 1,3-dichloro-5,5-dimethylhydantoin (DCDMH). Chemical neutralization of CAIS was effective in eliminating/reducing the vesicant property of CAIS containing agent in chloroform or agent on charcoal but was inefficient in reducing the vesicant potential of CAIS containing neat sulfur mustard.
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Arsenicales , Vesícula , Sustancias para la Guerra Química/toxicidad , Hidantoínas/toxicidad , Irritantes/toxicidad , Enfermedades de la Piel/inducido químicamente , Animales , Intoxicación por Arsénico , Vesícula/inducido químicamente , Vesícula/tratamiento farmacológico , Sustancias para la Guerra Química/metabolismo , Cobayas , Masculino , Mecloretamina/toxicidad , Gas Mostaza/toxicidad , Enfermedades de la Piel/tratamiento farmacológico , Factores de TiempoRESUMEN
A method of detecting signature methylphosphonic acid (MPA) breakdown products of V and G nerve agents in environmental samples was developed using capillary ion electrophoresis with conductivity detection. The electrolyte (30 mM L-histidine, 30 mM 2-(N-morpholino)ethanesulfonic acid, 0.7 mM tetradecyltrimethylammonium hydroxide, and 0.03 weight% Triton X-100) allowed baseline separation of MPA, ethyl methylphosphonic acid (EMPA), isopropyl methylphosphonic acid (IMPA), and pinacolyl methylphosphonic acid (PMPA) in less than 10 min. Detector response was linear in the 6-60 micrograms/ml concentration range (correlation coefficient = 0.99) with a detection limit around 6 micrograms/ml. The application of this method for screening MPA, EMPA, IMPA, and PMPA in surface water, groundwater, and soil extracts is demonstrated.
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Sustancias para la Guerra Química , Electroforesis Capilar/métodos , Compuestos Organofosforados/análisis , Suelo/análisis , Agua/análisis , Sustancias para la Guerra Química/análisis , Sustancias para la Guerra Química/química , Sistema Nervioso/efectos de los fármacos , Organofosfonatos/análisis , Soman/análogos & derivados , Soman/análisisRESUMEN
Refinement of the cell number by programmed cell death is a major morphogenetic mechanism of the developing central nervous system (CNS) in vertebrates including mammals, which determines to a significant degree its mature cytoarchitecture. We have examined the topography and the extent of cell death in different regions of the human CNS prenatally (11 fetuses), and in the early post-natal weeks (three newborns). Attention was focused on the wall of the telencephalon during a relatively short time period (12th-23rd week of gestation), corresponding to the time of major proliferation in the ventricular zone and to the peak of neuronal migration; both these mechanisms are crucial for corticogenesis. The TUNEL method was used, allowing the recognition of cell death because of its ability to label blunt ends of double-stranded DNA breaks. Morphological features of nuclei at different stages of apoptosis were identified, providing better evidence of the extent of the process than histological stains. Cell labelling was seen in either post-mitotic elements in the ventricular zone, or along the migratory pathways in the intermediate zone and subplate at all prenatal ages examined. No apoptotic nuclei were seen in the cortical plate. These findings suggest that apoptotic cell death drives the selection of cells which are committed to play a role during the early stages of corticogenesis. Lack of evidence of clonally related apoptotic cells also indicates that cell death occurs randomly. Therefore, molecular signals from the surrounding microenvironment seem to be necessary for the apoptotic pathway to be turned on, thus determining the fate of post-mitotic cells.