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Extreme heat is an increasing climate threat, most pronounced in urban areas where poor populations are at particular risk. We analyzed heat impacts and vulnerabilities of 1027 outdoor workers who participated in a KAP survey in Hanoi, Vietnam in 2018, and the influence of their mitigation actions, their knowledge of heat-risks, and access to early warnings. We grouped respondents by their main income (vendors, builders, shippers, others, multiple jobs, and non-working) and analyzed their reported heat-health impacts, taking into consideration socioeconomics, knowledge of heat impacts and preventive measures, actions taken, access to air-conditioning, drinking amounts and use of weather forecasts. We applied linear and logistic regression analyses using R. Construction workers were younger and had less knowledge of heat-health impacts, but also reported fewer symptoms. Older females were more likely to report symptoms and visit a doctor. Access to air-conditioning in the bedroom depended on age and house ownership, but did not influence heat impacts as cooling was too expensive. Respondents who knew more heat exhaustion symptoms were more likely to report impacts (p < 0.01) or consult a doctor (p < 0.05). Similarly, those who checked weather updates were more likely to report heat impacts (p < 0.01) and experienced about 0.6 more symptoms (p < 0.01). Even though occupation type did not explain heat illness, builders knew considerably less (40%; p < 0.05) about heat than other groups but were twice as likely to consult a doctor than street vendors (p < 0.01). Knowledge of preventive actions and taking these actions both correlated positively with reporting of heat-health symptoms, while drinking water did not reduce these symptoms (p < 0.01). Child carers and homeowners experienced income losses in heatwaves (p < 0.01). The differences support directed actions, such as dissemination of educational materials and weather forecasts for construction workers. The Red Cross assisted all groups with cooling tents, provision of drinks and health advice.
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Calor Extremo , Trastornos de Estrés por Calor , Calor Extremo/efectos adversos , Femenino , Calor , Humanos , Masculino , Percepción , VietnamRESUMEN
BACKGROUND AND PURPOSE: Our aim was to use 2D convolutional neural networks for automatic segmentation of the spinal cord and traumatic contusion injury from axial T2-weighted MR imaging in a cohort of patients with acute spinal cord injury. MATERIALS AND METHODS: Forty-seven patients who underwent 3T MR imaging within 24 hours of spinal cord injury were included. We developed an image-analysis pipeline integrating 2D convolutional neural networks for whole spinal cord and intramedullary spinal cord lesion segmentation. Linear mixed modeling was used to compare test segmentation results between our spinal cord injury convolutional neural network (Brain and Spinal Cord Injury Center segmentation) and current state-of-the-art methods. Volumes of segmented lesions were then used in a linear regression analysis to determine associations with motor scores. RESULTS: Compared with manual labeling, the average test set Dice coefficient for the Brain and Spinal Cord Injury Center segmentation model was 0.93 for spinal cord segmentation versus 0.80 for PropSeg and 0.90 for DeepSeg (both components of the Spinal Cord Toolbox). Linear mixed modeling showed a significant difference between Brain and Spinal Cord Injury Center segmentation compared with PropSeg (P < .001) and DeepSeg (P < .05). Brain and Spinal Cord Injury Center segmentation showed significantly better adaptability to damaged areas compared with PropSeg (P < .001) and DeepSeg (P < .02). The contusion injury volumes based on automated segmentation were significantly associated with motor scores at admission (P = .002) and discharge (P = .009). CONCLUSIONS: Brain and Spinal Cord Injury Center segmentation of the spinal cord compares favorably with available segmentation tools in a population with acute spinal cord injury. Volumes of injury derived from automated lesion segmentation with Brain and Spinal Cord Injury Center segmentation correlate with measures of motor impairment in the acute phase. Targeted convolutional neural network training in acute spinal cord injury enhances algorithm performance for this patient population and provides clinically relevant metrics of cord injury.
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Aprendizaje Profundo , Interpretación de Imagen Asistida por Computador/métodos , Trastornos Motores/etiología , Traumatismos de la Médula Espinal/complicaciones , Traumatismos de la Médula Espinal/diagnóstico por imagen , Contusiones/diagnóstico por imagen , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Imagen por Resonancia Magnética/métodos , MasculinoRESUMEN
BACKGROUND AND PURPOSE: There is an emerging need for biomarkers to better categorize clinical phenotypes and predict progression in amyotrophic lateral sclerosis. This study aimed to quantify cervical spinal gray matter atrophy in amyotrophic lateral sclerosis and investigate its association with clinical disability at baseline and after 1 year. MATERIALS AND METHODS: Twenty-nine patients with amyotrophic lateral sclerosis and 22 healthy controls were scanned with 3T MR imaging. Standard functional scale was recorded at the time of MR imaging and after 1 year. MR imaging data were processed automatically to measure the spinal cord, gray matter, and white matter cross-sectional areas. A statistical analysis assessed the difference in cross-sectional areas between patients with amyotrophic lateral sclerosis and controls, correlations between spinal cord and gray matter atrophy to clinical disability at baseline and at 1 year, and prediction of clinical disability at 1 year. RESULTS: Gray matter atrophy was more sensitive to discriminate patients with amyotrophic lateral sclerosis from controls (P = .004) compared with spinal cord atrophy (P = .02). Gray matter and spinal cord cross-sectional areas showed good correlations with clinical scores at baseline (R = 0.56 for gray matter and R = 0.55 for spinal cord; P < .01). Prediction at 1 year with clinical scores (R2 = 0.54) was improved when including a combination of gray matter and white matter cross-sectional areas (R2 = 0.74). CONCLUSIONS: Although improvements over spinal cord cross-sectional areas were modest, this study suggests the potential use of gray matter cross-sectional areas as an MR imaging structural biomarker to monitor the evolution of amyotrophic lateral sclerosis.
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Esclerosis Amiotrófica Lateral/patología , Sustancia Gris/patología , Médula Espinal/patología , Adulto , Esclerosis Amiotrófica Lateral/diagnóstico por imagen , Atrofia/diagnóstico por imagen , Atrofia/patología , Progresión de la Enfermedad , Femenino , Sustancia Gris/diagnóstico por imagen , Humanos , Interpretación de Imagen Asistida por Computador , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Médula Espinal/diagnóstico por imagenRESUMEN
Ossifying fibroma (OF) is a benign fibro-osseous lesion mainly occurring in young adults and seems to originate from the periodontal ligament. Aneurysmal bone cyst (ABC) is a benign intraosseous lesion characterized by blood-filled spaces of various sizes. These two lesions can specifically affect the jaws and are commonly described in the literature. However, few cases describing an association of OF and ABC have been reported in the literature, especially in the maxillary sinus. We report the case of a 40-year-old male patient affected with an asymptomatic lesion with a dual component of OF and ABC laying in the maxillary sinus. Our aim is to discuss its clinical and morphological features as well as treatment results.
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Quistes Óseos Aneurismáticos , Fibroma Osificante , Fístula , Adulto , Tratamiento Conservador , Femenino , Humanos , Masculino , Seno Maxilar , Embarazo , Adulto JovenRESUMEN
BACKGROUND: Temporal and frontotemporal skin defects can be repaired using various reconstruction procedures: temporojugal rotation-advancement flaps, frontotemporal advancement flaps, skin grafts, etc. We propose an alternative method using a rhomboid transposition flap, thus extending the possibilities for repair in this region. MATERIALS AND METHODS: This is a retrospective, non-comparative study of patients in whom a rhomboid transposition flap of the temporal or frontotemporal region was created between February 2008 and March 2010. Sex, age, hospitalization, histological type of the excised lesion, type of anaesthesia, defect size, possible occurrence of complications and outcome were compiled from the medical records. RESULTS: Eleven patients (five women and six men) of average age 76 years were included. The lesions were due in all cases to basal cell carcinoma. Five patients were ambulatory and seven were hospitalized. All patients underwent surgery under local anaesthesia in a single session. Hospitalized patients had more extensive cutaneous defects, were older and had more comorbidities. One patient presented incomplete lateral resection. The most frequent complication was bruising on the lower eyelid (5/11), and two more severe complications occurred: distal flap necrosis and haematoma. The aesthetic result was good for all patients after a mean 20months of follow-up. CONCLUSION: Rhomboid transposition flaps appear to be a reconstruction option that warrants consideration in cutaneous defects in the temporal or frontotemporal region.
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Carcinoma Basocelular/cirugía , Cara/cirugía , Neoplasias Faciales/cirugía , Procedimientos de Cirugía Plástica , Colgajos Quirúrgicos , Anciano , Contusiones/epidemiología , Contusiones/etiología , Estética , Femenino , Estudios de Seguimiento , Frente/cirugía , Hematoma/epidemiología , Hematoma/etiología , Humanos , Masculino , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología , Estudios Retrospectivos , Técnicas de SuturaRESUMEN
OBJECTIVE: The authors had for aim to describe the epidemiological and clinical characteristics, and the treatment of patients presenting with skin and soft tissue infections due to Panton-Valentine leukocidin (PVL) producing Staphylococcus aureus in the Nord-Pas-de-Calais (NPDC) region, North of France. METHODS: We included patients presenting with PVL producing S. aureus infection from seven hospitals in the NPDC region, between February 2004 and April 2008. We retrospectively collected patient data using a standardized questionnaire. The features of patients presenting with skin and soft tissue were then analyzed. RESULTS: PVL producing S. aureus was isolated from 64 patients. Fifty-four patients presented with skin and soft tissue infections. The mean age of patients was 23.8 years (63% male patients). The mean number of persons living with the infected patient was 4.5 (vs. 2.5 in NPDC). The lesions were abscesses with inflammatory signs in 64.8% of the cases (20% were necrotic). Among the patients, 70.3% carried a methicillin resistant strain. Antibiotics per os were used for 83.3% of patients; the first-line antibiotics were considered inadequate in 53.3% of the cases. Among the patients, 83.3% underwent surgery. Fourteen out of 38 patients with available data had been exposed to antibiotic therapy during the three months before hospital management. CONCLUSION: Recent exposure to antibiotics and living with a high number of persons are reasons to suspect a PVL producing S. aureus infection in patients with skin abscess.
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Toxinas Bacterianas/biosíntesis , Exotoxinas/biosíntesis , Leucocidinas/biosíntesis , Infecciones de los Tejidos Blandos/microbiología , Infecciones Estafilocócicas/microbiología , Infecciones Cutáneas Estafilocócicas/microbiología , Staphylococcus aureus/metabolismo , Adolescente , Niño , Femenino , Humanos , Lactante , Masculino , Estudios Retrospectivos , Infecciones de los Tejidos Blandos/epidemiología , Infecciones Estafilocócicas/epidemiología , Infecciones Cutáneas Estafilocócicas/epidemiología , Adulto JovenRESUMEN
OBJECTIVE: The aim of this study was to provide a quantification of taurodontism in Hypohidrotic Ectodermal Dysplasia (HED) and to report its occurrence in a cohort of HED patients to assess phenotypic-genotypic correlations. PATIENTS AND METHODS: Of 68 HED patients retrospectively reviewed, 16 patients aged 7-51 years were selected and compared with a control sample (n = 351). The pulp surface index of the first lower permanent molar was calculated from the panoramic radiograph of each individual, and statistical comparisons between the HED patients and the control sample were performed. RESULTS: Whatever the genetic disorder, 81.25% of the HED patients exhibited a relative enlargement (>or=1 s.d.) of the pulp. Major deviations (>5 s.d.) were respectively related to men affected by large deletion of the EDA gene or missense mutation. The autosomal recessive form was linked to a relative moderate pulp enlargement (3.44 s.d.). In NEMO forms, the increase of pulp size in men appeared to be less marked than in EDA mutations. CONCLUSION: This study provides for the first time an objective assessment of pulp enlargement in HED patients, and the various degrees of taurodontism depicted could be interesting dental phenotypic markers of HED forms.
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Cavidad Pulpar/anomalías , Displasia Ectodermal Anhidrótica Tipo 1/diagnóstico , Displasia Ectodérmica Anhidrótica Tipo 3/diagnóstico , Displasia Ectodérmica Hipohidrótica Autosómica Recesiva/diagnóstico , Anomalías Dentarias/genética , Adolescente , Adulto , Estudios de Casos y Controles , Niño , Preescolar , Análisis Mutacional de ADN , Cavidad Pulpar/diagnóstico por imagen , Displasia Ectodermal Anhidrótica Tipo 1/complicaciones , Displasia Ectodermal Anhidrótica Tipo 1/genética , Displasia Ectodérmica Anhidrótica Tipo 3/complicaciones , Displasia Ectodérmica Anhidrótica Tipo 3/genética , Displasia Ectodérmica Hipohidrótica Autosómica Recesiva/complicaciones , Displasia Ectodérmica Hipohidrótica Autosómica Recesiva/genética , Ectodisplasinas/genética , Femenino , Humanos , Quinasa I-kappa B/genética , Masculino , Persona de Mediana Edad , Diente Molar/anomalías , Diente Molar/diagnóstico por imagen , Mutación Missense , Radiografía , Estudios Retrospectivos , Eliminación de Secuencia , Anomalías Dentarias/etiología , Adulto JovenRESUMEN
BACKGROUND: Leflunomide is prescribed in inflammatory rheumatisms. Cutaneous side effects have rarely been described. We report the case of a patient presenting skin necrosis attributed to this drug. PATIENTS AND METHODS: A 73-year-old woman had been taking leflunomide for psoriatic arthritis for one year and subsequently, developed three abdominal ulcerations and necrosis of one hallux. No immunological, vascular or neoplastic aetiology was found. Corticotherapy was started, based on a hypothesis of vasculitis, but lesions progressed, leading to amputation of the hallux. Leflunomide was stopped and the ulcerations healed completely within 12 weeks, whereas prolonged local treatment had failed to yield any improvement. DISCUSSION: Skin necrosis due to leflunomide is rare; we found seven cases in the literature. Ulcerations may occur anywhere. Potentially life-threatening glomerulonephritis with mesangial deposits may be associated. Discontinuation of leflunomide followed by wash-out with cholestyramine allows healing. Corticosteroids or cyclophosphamide are sometimes necessary. The ulcerations appear to be result from excessive immunomodulation in the skin or from an inhibiting role of leflunomide on the epidermal growth factor receptor. CONCLUSION: In the absence of any demonstrated aetiology in patients presenting ulcerations or skin necrosis, a contributory role of leflunomide must be considered, even in cases of prolonged use.
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Antiinflamatorios no Esteroideos/efectos adversos , Artritis Psoriásica/tratamiento farmacológico , Isoxazoles/efectos adversos , Piel/patología , Abdomen/patología , Anciano , Femenino , Estudios de Seguimiento , Humanos , Leflunamida , Necrosis , Piel/efectos de los fármacos , Factores de TiempoRESUMEN
Vertebral osteomyelitis is a quite rare but severe cause of back pain in adults. Various causative organisms have been reported. Pasteurella species have rarely been isolated. We report here a case of vertebral osteomyelitis and consecutive cauda equina syndrome due to Pasteurella dagmatis in a 60-year-old diabetic man.
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Osteomielitis/microbiología , Infecciones por Pasteurella/diagnóstico , Columna Vertebral/microbiología , Diabetes Mellitus Tipo 2/complicaciones , Humanos , Masculino , Persona de Mediana Edad , Osteomielitis/complicaciones , Polirradiculopatía/microbiologíaRESUMEN
Following the recent discussion on the puzzling nature of the interactions in the nanotubular system Na(2)V(3)O(7), we present a detailed ab initio microscopic analysis of its electronic and magnetic properties. By means of a nontrivial downfolding study we propose an effective model in terms of tubes of nine-site rings with the geometry of a spin-diamond necklace with frustrated inter-ring interactions. We show that this model provides a quantitative account of the observed magnetic behavior.
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OBJECTIVES: To evaluate the efficiency and acceptance of digital pen and paper technology for real-time clinical data acquisition. METHODS: A prospective interventional unblinded study involving consecutive patients in two clinical settings during a defined time-frame was proposed. The first trial was designed as a stress test to evaluate acceptance in a workload-intensive environment. Acceptance was assessed using observations and a satisfaction questionnaire. The second trial was intended to determine the reliability of data acquisition in a controlled environment. Reliability was assessed by comparing the performance of the digital pen against scanner analysis and a double human blinded acquisition. RESULTS: Overall, users were satisfied with the use of the digital pen (median 3 on a Likert-scale (-5, 5)). Without any specific user training, successful data acquisition was greater than 80%. Use of this technology required less adaptation than standard computer devices, and was easy to learn and use. Ergonomic problems shaded the perception of the technology by inducing an increased cognitive load. Digitalized data was missing either because of a bug or due to lack of data validation. The reliability obtained with the digital pen was significantly lower to that obtained with the scanner. CONCLUSIONS: Natural technology such as the digital pen proved to be a good tool in stressful clinical environments without interfering with the normal workload or increasing the time for data acquisition. However, in order to improve quality of data acquisition, designing acquisition forms specifically for the use of digital pens is of paramount importance.
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Actitud del Personal de Salud , Actitud hacia los Computadores , Procesamiento Automatizado de Datos/instrumentación , Sistemas de Información en Hospital , Sistemas de Registros Médicos Computarizados , Satisfacción del Paciente , Evaluación de la Tecnología Biomédica , Anestesia Obstétrica , Ergonomía , Hospitales Universitarios , Humanos , Papel , Evaluación de Procesos, Atención de Salud , Estudios Prospectivos , Encuestas y Cuestionarios , Suiza , Triaje , Carga de Trabajo/psicologíaRESUMEN
The influence of dissolved inorganic nitrogen (DIN) enrichments on cell-normalized carbon uptake rate, chlorophyll a content, and apparent cell size of a picoeukaryote (<1 microm) ( Ostreococcus tauri, the smallest eukaryotic cell) from a natural summer phytoplanktonic assemblage (<200 microm) in a northern Mediterranean Lagoon (Thau Lagoon) was studied in 20-L enclosures in June 1995. The natural planktonic community was incubated in situ for 24 h with initial ammonium and nitrate enrichments and compared to a control without enrichment. O. tauri cell-normalized productivity was estimated from the combination of flow cytometric (FCM) enumeration and 2-h (radioactive) carbonate incorporation measured on post-incubation size fractions (<1microm). No difference between the effects of the two DIN sources of enrichment on the studied biological parameters was measured during this experiment. Growth of natural O. tauri was perturbed by the low DIN availability in the control with drastic changes in cell productivity, chlorophyll content, and cell cycle (from the variations in apparent cell size) as compared to the DIN sufficiency conditions. On the other hand, a very high specific growth rate for natural O. tauri, up to 8 day(-1) under DIN enrichments, has been estimated from production and abundance data obtained during this experiment. This supports values measured in culture and suggests that the yearly high contribution of picophytoplankton to the total primary production in Thau Lagoon is likely to be due to their high growth rate rather than the previously suggested lack of grazing pressure.
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Carbono/metabolismo , Chlorophyta/metabolismo , Compuestos de Nitrógeno/farmacología , Fitoplancton/metabolismo , Carbonatos/metabolismo , División Celular/efectos de los fármacos , Chlorophyta/efectos de los fármacos , Chlorophyta/crecimiento & desarrollo , Citometría de Flujo , Francia , Mar Mediterráneo , Compuestos de Nitrógeno/metabolismo , Fitoplancton/efectos de los fármacosRESUMEN
OBJECTIVE AND METHOD: We have evaluated the sensitivity of a diagnostic algorithm for all patients suspected of pulmonary embolism using: D-Dimer, lower limb venous ultrasonography and helical computed tomography. To validate this approach, a lung scan is systematically carried out if the pulmonary embolism diagnosis is not withheld as a result of the algorithm. Clinical tests are organised between the 3rd and 6th month. RESULTS: Two hundred patients were involved between January 1998 and October 1999. One hundred and six pulmonary embolisms were diagnosed. Out of the 200 ultrasonography tests carried out we found: 71 proximal deep-vein thrombosis (popliteal or supra-popliteal), 33 distal thrombosis (infra-popliteal). Ninety-two cases were negative (4 tests non conclusive). We have deduced that a deep-vein thrombosis permits the diagnosis of thrombo-embolic illness without any further diagnostic approach (no computed tomography). Out of the 129 computed tomographies carried out we found: 35 pulmonary embolisms and 23 other diagnoses. Seventy-one lung scans were therefore carried out. We recorded 7 discordances (scans showed high and very high probability for pulmonary embolism whilst computed tomographies did not): pulmonary angiography was negative 4 times and diagnosed pulmonary embolism once and two patients refused to take the test (Table 2). There are two recurrences in the follow-up: proximal thrombosis and a pulmonary embolism. This involved two patients who had refused to undergo pulmonary angiography. CONCLUSION: This diagnostic approach therefore seems satisfactory but would require further investigation on a wider scale.
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Algoritmos , Productos de Degradación de Fibrina-Fibrinógeno/análisis , Embolia Pulmonar/diagnóstico , Trombosis de la Vena/diagnóstico , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores/análisis , Femenino , Francia , Hospitales Generales , Humanos , Extremidad Inferior/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Vena Poplítea/diagnóstico por imagen , Embolia Pulmonar/sangre , Embolia Pulmonar/diagnóstico por imagen , Estudios Retrospectivos , Sensibilidad y Especificidad , Tomografía Computarizada Espiral , Ultrasonografía , Trombosis de la Vena/sangre , Trombosis de la Vena/diagnóstico por imagenRESUMEN
In summer 2000, symptoms similar to Pelargonium zonate spot virus (PZSV) were observed for the first time on tomato plants in southeastern France. The plants were from commercial glasshouse fresh-market crops. Symptoms observed were chlorotic mottling with bright yellow distinct rings on leaves and curved line patterns on stems. Fruit symptoms included chlorotic and necrotic spotting, marked concentric ring patterns, and distortions. Diagnosis was made from symptomatic leaves and fruits by mechanical inoculation on a set of host plants. Local chlorotic and necrotic lesions were observed on Chenopodium amaranticolor, C. quinoa, Cucumis sativus cv. Marketer, Cucumis melo cv. Vedrantais, Phaseolus vulgaris cv. Pinto, Vicia faba cv. D'Aguadulce, Vigna unguiculata cv. Black Eye, and systemic symptoms were observed on Capsicum annuum cvs. Yolo Wonder, Yolo Y, Florida VR2, and Criollo de Morelos 334, Datura stramonium, Lycopersicon esculentum cvs. Momor and Stevens, L. hirsutum (PI 134417 and PI 247087), Nicotiana benthamiana, N. clevelandii, N. tabacum cv. Xanthi nc, Ocimum basilicum cv. Latino, Petunia hybrida cv. Rose du ciel, and Physalis floridana. No reaction was observed on Pisum sativum cv. Douce Provence, Salvia splendens cv. Etna, or Zinnia elegans cv. Liliput. Symptoms on tomato of PZSV, Parietaria mottle virus (PMoV), and Tomato spotted wilt virus (TSWV) are similar, particularly those elicited in fruits. Therefore, the field samples were checked using double-antibody sandwich enzyme-linked immunosorbent assay against antisera of the type-strain of PZSV and tomato strain of PMoV and their homologous antigenes, which were supplied by D. Gallitelli and P. Roggero respectively, and our antiserum of TSWV. Electron microscopy of negatively stained preparations from leaves of tomato and D. stramonium showed that the sap contained very few paraspheric shaped particles, 26 to 29 nm in diameter. Three isolates collected from two different regions (Vaucluse and Bouches du Rhône) showed a very close serological relationship with the Italian type-strain of PZSV and tested negative against antisera of PMoV and TSWV. The French isolates were biologically different from the type-strain, but were similar to the Spanish strain of PZSV because they infected D. stramonium, N. benthamiana, O. basilicum, and V. unguiculata (2). Moreover, in transverse tissue sections, virions were not observed in the nucleus and tubular structures, unlike the Italian isolates, (1) but were present in the cytoplasm and particularly in the mesophyll cells. There are only a few records of the occurrence and distribution of PZSV in Mediterranean countries. References: (1) M. A Castellano and G. P Martelli. Phytopathol. Mediterr. 20:64, 1981. (2) M. Luis-Arteaga. Plant Dis. 84:807, 2000.
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Thermodynamic experiments as well as Raman scattering have been used to study the magnetic instabilities in the spin-tetrahedra systems Cu(2)Te(2)O(5)X(2), X = Cl and Br. While the phase transition observed in the Cl system at T(N) = 18.2 K is consistent with 3D antiferromagnetic ordering, the phase transition at T(o) = 11.4 K in the Br system has several unusual features. We propose an explanation in terms of weakly coupled tetrahedra with a singlet-triplet gap and low-lying singlets.
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Neurons in culture rely on the supply of exogenous cysteine for their glutathione synthesis. After application of cysteine to neuron-rich primary cultures, the glutathione content was doubled after a 4-hr incubation. The dipeptide cysteinylglycine (CysGly) was able to substitute for cysteine as exogenous glutathione precursor. In kidneys, the ectopeptidase aminopeptidase N (ApN) has been reported to hydrolyze CysGly. Expression of mRNA of ApN in rat brain and cultured rat neurons was demonstrated by reverse transcriptase polymerase chain reaction and sequencing of the cDNA fragment obtained. In addition, the presence of ApN protein in cultured neurons was demonstrated by its immunocytochemical localization. In the presence of an activity-inhibiting antiserum against ApN the utilization of CysGly as neuronal glutathione precursor was completely prevented, whereas that of cysteine plus glycine was not affected. The data presented demonstrates that cultured rat neurons express ApN and that this ectopeptidase participates in the utilization of CysGly as precursor for neuronal glutathione.
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Antígenos CD13/genética , Sistema Nervioso Central/enzimología , Cisteína/metabolismo , Dipéptidos/metabolismo , Glutatión/biosíntesis , Glicina/metabolismo , Neuronas/enzimología , Animales , Antígenos CD13/antagonistas & inhibidores , Antígenos CD13/metabolismo , Células Cultivadas , Cisteína/farmacología , ADN Complementario/metabolismo , Dipéptidos/farmacología , Feto , Glicina/farmacología , Inmunohistoquímica , Enfermedades Neurodegenerativas/enzimología , Enfermedades Neurodegenerativas/fisiopatología , Estrés Oxidativo/fisiología , ARN Mensajero/metabolismo , Ratas , Ratas Wistar , Especies Reactivas de Oxígeno/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
The synthesis, spectroscopic properties, and electrochemistry of six different alkyl- and aryl-substituted Co(III) corroles are presented. The investigated compounds contain methyl, ethyl, phenyl, or substituted phenyl groups at the eight beta-positions of the corrole macrocycle and four derivatives also contain a phenyl group at the 10-meso position of the macrocycle. Each cobalt corrole undergoes four reversible oxidations in CH(2)Cl(2) containing 0.1 M tetra-n-butylammonium perchlorate and exists as a dimer in its singly and doubly oxidized forms. The difference in potential between the first two oxidations is associated with the degree of interaction between the two corrole units of the dimer and ranges from an upper value of 0.62 V, in the case of (Me(6)Et(2)Cor)Co, to a lower value of about 0.17 V, in the case of four compounds which have a phenyl group located at the 10-meso position of the macrocycle. These Co(III) corroles strongly coordinate two pyridine molecules or one carbon monoxide molecule in CH(2)Cl(2) media, and ligand binding constants were evaluated using spectroscopic and electrochemical methods. The structure of (Me(4)Ph(5)Cor)Co(py)(2) was also determined by X-ray diffraction. Crystal data: (Me(4)Ph(5)Cor)Co(py)(2).3CH(2)Cl(2).H(2)O, orthorhombic, a = 19.5690(4) A, b = 17.1070(6) A, c = 15.9160(6) A, V = 5328.2(5) A(3), space group Pna2(1), Z = 2, 35 460 observations, R(F) = 0.069.
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The synthesis, spectroscopic properties, and electrochemistry of (BCA)Co(2) and (BCB)Co(2) are described where BCA and BCB represent biscorroles linked by an anthracenyl (A) or a biphenylenyl (B) bridge. The pyridine and CO binding properties of (BCA)Co(2) and (BCB)Co(2) are also presented, and one of the compounds in its pyridine-ligated form, (BCA)Co(2)(py)(3), is structurally characterized. The data on the biscorroles are compared on one hand to the monocorrole having the same substitution pattern and on the other hand to bisporphyrins having two Co(II) ions and the same anthracenyl or biphenylenyl linkers in order to better understand the interaction which occurs between the two corrole macrocycles. A parallel study on five different Co(III) phenyl-substituted corroles showed that bis-pyridine and mono-CO adducts are readily formed from the complexes in CH(2)Cl(2). This present paper examines how the ligand binding properties and electrochemistry of these Co(III) corroles are modified by the anthracenyl or biphenylenyl bridge which links the two macrocycles in a face to face orientation. An X-ray crystal structure was obtained for the tris-pyridine adduct of the anthracenyl bridged derivative, (BCA)Co(2)(py)(3), and gives the following results: C(127)H(99)Co(2)N(11).2CHCl(3), M = 2135.90, triclinic, space group P&onemacr;, a = 13.2555(5) A, b = 18.6406(8) A, c = 22.2140(9) A, alpha = 94.186(9) degrees, beta = 102.273(9) degrees, gamma = 94.205(9) degrees, V = 5326.8(4) A(3), 9293 independent reflections collected, R(F) = 0.066.