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1.
Phys Chem Chem Phys ; 23(46): 26120-26129, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34559176

RESUMO

This study compares molecular calculations performed with molecular and periodic codes through an investigation of the solvation structures of alkali and alkaline earth metal ions in tetraglyme solution. The two codes are able to produce equivalent structural and energetic information at the same level of theory, and in the presence of the implicit solvation model or not. This comparison reveals that molecular optimisations can be performed with periodic codes and used directly as input models for interface or electrochemistry calculations in order to preserve the solvent-solute interaction and the cavitation energy. By a rigorous comparison, we have demonstrated that equivalent energetic values can be obtained with the conventional PBE-D3 and the newly developed SCAN-rVV10 functionals. Nevertheless, as far as the vibrational features are concerned and when the molecule possesses a highly conjugated system, the SCAN-rVV10 functional is required to describe the vibrational modes properly. The computed IR/Raman spectra can thus be used as essential information to determine the first solvation shell of metal ions in glyme-based solutions. In tetraglyme solution, the alkali and alkaline earth metal ions exhibit a diverse solvation structure. Small ions like Li+ and Mg2+ tend to adopt a coordination number of five or six, while larger ions, Na+, K+, and Ca2+, prefer an eight-coordinated environment, and the metal-ligand interaction increases in the order K+-O < Na+-O < Li+-O < Ca2+-O < Mg2+-O. The solvation spheres play a significant role in the stability and the reactivity of the solvated ions, and can thus be used as input models to construct the solvation structure in more sophisticated electrolytes, such as polyethylene oxide, or perform electrochemical calculations.

2.
Nano Lett ; 19(10): 7210-7216, 2019 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-31487461

RESUMO

At cryogenic temperature and at the single emitter level, the optical properties of single-wall carbon nanotubes depart drastically from that of a one-dimensional (1D) object. In fact, the (usually unintentional) localization of excitons in local potential wells leads to nearly 0D behaviors such as photon antibunching, spectral diffusion, inhomogeneous broadening, etc. Here, we present a hyperspectral imaging of this spontaneous exciton localization effect at the single nanotube level using a super-resolved optical microscopy approach. We report on the statistical distribution of the trap localization, depth, and width. We use a quasi-resonant photoluminescence excitation approach to probe the confined quantum states. Numerical simulations of the quantum states and exciton diffusion show that the excitonic states are deeply modified by the interface disorder inducing a remarkable discretization of the excitonic absorption spectrum and a quenching of the free 1D exciton absorption.

3.
Ultrasound Obstet Gynecol ; 54(5): 650-654, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30478919

RESUMO

OBJECTIVE: To evaluate whether an automated tool can recognize a structure of interest and measure fetal head circumference (HC), abdominal circumference (AC) and femur length (FL) on frozen two-dimensional ultrasound images. METHODS: Ultrasound examinations were performed in 100 singleton pregnancies between 20 and 40 weeks of gestation, ensuring an even distribution throughout gestational age. In each pregnancy, three standard biometric variables (HC, AC, FL) were measured each in three different images obtained for this purpose (i.e. nine independent image acquisitions). An algorithm (Philips Research) was used to detect the structure of interest and automatically place calipers for measurement. Caliper placement was assessed in two ways. First, subjective clinical assessment was performed to determine whether the caliper placement was correct, and caliper position was classified as 'acceptable for clinical use', 'minor adjustment required' or 'major adjustment required'. Second, the resulting automatic measurements were compared with manual measurements, taken in real time. Mean difference errors were calculated and expressed as percentages to correct for fetal growth with advancing gestation. RESULTS: After exclusion of one pregnancy due to missing images, a total of 891 images (297 for each biometric variable) from 99 pregnancies were analyzed. The algorithm failed to place calipers for the AC in nine images, whereas there were no failures in caliper placement for measurement of HC and FL. On subjective quality assessment of automatic caliper placement, in 475 (53.3%) images position of the calipers was judged to be clinically acceptable and did not require any adjustment, while in 317 (35.6%) and 90 images (10.1%) minor and major adjustments were required, respectively. The mean error between manual and automatic measurement of HC was -0.21 cm corresponding to a percentage error of -0.81% with 95% limits of agreement (LOA) between -3.73% and 2.12%. For AC and FL measurements, the mean error was, respectively, 0.72 cm (percentage error, 2.40%) with LOA between -9.48% and 14.27%, and 0.21 cm (percentage error, 3.76%) with LOA between -8.38% and 15.91%. CONCLUSIONS: The automated tool identified correctly the biometric variable of interest in 99% of frozen images. The resulting measurements had a high degree of accuracy and compared well with previously published manual-to-manual agreement. The measurements exhibited bias, with the automated tool underestimating biometry; this could be overcome by further improvements in the algorithm. Nevertheless, adjustable calipers for manual correction remains a requirement. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.


Assuntos
Biometria/instrumentação , Desenvolvimento Fetal , Feto/diagnóstico por imagem , Adolescente , Adulto , Algoritmos , Automação , Feminino , Fêmur/diagnóstico por imagem , Fêmur/embriologia , Idade Gestacional , Cabeça/diagnóstico por imagem , Cabeça/embriologia , Humanos , Gravidez , Ultrassonografia Pré-Natal/métodos , Circunferência da Cintura , Adulto Jovem
4.
J Exp Bot ; 67(20): 5887-5900, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27639093

RESUMO

Programmed cell death (PCD) is a ubiquitous genetically regulated process consisting of the activation of finely controlled signalling pathways that lead to cellular suicide. PCD can be part of a developmental programme (dPCD) or be triggered by environmental conditions (ePCD). In plant cells, as in animal cells, extensive chromatin condensation and degradation of the nuclear DNA are among the most conspicuous features of cells undergoing PCD. Changes in chromatin condensation could either reflect the structural changes required for internucleosomal fragmentation of nuclear DNA or relate to large-scale chromatin rearrangements associated with a major transcriptional switch occurring during cell death. The aim of this review is to give an update on plant PCD processes from a chromatin point of view. The first part will be dedicated to chromatin conformational changes associated with cell death observed in various developmental and physiological conditions, whereas the second part will be devoted to histone dynamics and DNA modifications associated with critical changes in genome expression during the cell death process.


Assuntos
Apoptose/fisiologia , Cromatina/fisiologia , DNA de Plantas/fisiologia , Fenômenos Fisiológicos Vegetais , Plantas/metabolismo
5.
Phys Rev Lett ; 116(24): 247402, 2016 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-27367407

RESUMO

The narrow emission of a single carbon nanotube at low temperature is coupled to the optical mode of a fiber microcavity using the built-in spatial and spectral matching brought by this flexible geometry. A thorough cw and time-resolved investigation of the very same emitter both in free space and in cavity shows an efficient funneling of the emission into the cavity mode together with a strong emission enhancement corresponding to a Purcell factor of up to 5. At the same time, the emitted photons retain a strong sub-Poissonian statistics. By exploiting the cavity feeding effect on the phonon wings, we locked the emission of the nanotube at the cavity resonance frequency, which allowed us to tune the frequency over a 4 THz band while keeping an almost perfect antibunching. By choosing the nanotube diameter appropriately, this study paves the way to the development of carbon-based tunable single-photon sources in the telecom bands.

6.
J Evol Biol ; 29(1): 114-25, 2016 01.
Artigo em Inglês | MEDLINE | ID: mdl-26406269

RESUMO

Host specialization plays a key role in the extreme diversification of phytophagous insects. Whereas proximate mechanisms of specialization have been studied extensively, their consequences for species divergence remain unclear. Preference for, and performance on hosts are thought to be a major source of divergence in phytophagous insects. We assessed these major components of specialization in two moth species, the European corn borer (ECB) and the Adzuki bean borer (ABB), by testing their oviposition behaviour in different conditions (choice or no-choice set-ups) and their performances, by reciprocal transplant at the larval stage on the usual host and an alternative host plant. We demonstrated that both ABB and ECB have a strong preference for their host plants for oviposition, but that relative larval performances on the usual host and an alternative host differed according to the experiment and the trait considered (weight or survival). Finally, we show for the first time that the preference for maize in ECB conceals a strong avoidance of mugwort. The differences in performance, attraction and avoidance between ECB and ABB are discussed in the light of the underlying mechanisms and divergence process.


Assuntos
Especificidade de Hospedeiro , Mariposas/fisiologia , Animais , Aprendizagem da Esquiva/fisiologia , Feminino , Larva , Oviposição , Especificidade da Espécie , Zea mays
7.
BMC Cancer ; 15: 857, 2015 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-26546402

RESUMO

BACKGROUND: Malignant pleural mesothelioma (MPM) is a rare disease with poor prognosis in spite of significant improvement in survival, due to new chemotherapy regimens. We describe here patients' profiles and management in daily practice in France. METHODS: Observational retrospective study. Data were collected from medical files. All patients with histologically proven MPM diagnosed from January 2005 to December 2008 were included in the participating sites. RESULTS: Four hundred and six patients were included in 37 sites: mean age 68.9 ± 9.8 years, male predominance (sex ratio 3.27), latency of the disease 45.7 years, epithelioïd type 83 %. Diagnosis was made using thoracoscopy in 80.8 % of patients. Radical surgery was performed in 6.2 % of cases. Chemotherapy was administered to 74.6 % of patients. First line regimens consisted mainly of platinum + pemetrexed (91 %) or pemetrexed alone (7 %). Objective response rate was 17.2 % and another 41.6 % of patients experienced disease stabilization. Half of these patients underwent second line chemotherapy (platinium + pemetrexed 31.6 %, pemetrexed alone 24.6 %), resulting in a 6 % response rate. Third-line chemotherapy (56 patients) yielded disease control in 5.4 % of cases. CONCLUSIONS: The management of MPM in France is usually in accordance with guidelines. Response rates are somewhat lower than those described in clinical trials.


Assuntos
Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/terapia , Mesotelioma/diagnóstico , Mesotelioma/terapia , Neoplasias Pleurais/diagnóstico , Neoplasias Pleurais/terapia , Idoso , Gerenciamento Clínico , Feminino , França/epidemiologia , Humanos , Neoplasias Pulmonares/epidemiologia , Masculino , Mesotelioma/epidemiologia , Mesotelioma Maligno , Pessoa de Meia-Idade , Avaliação de Resultados em Cuidados de Saúde , Neoplasias Pleurais/epidemiologia , Estudos Retrospectivos , Fatores de Risco
8.
Ann Dermatol Venereol ; 142(2): 121-4, 2015 Feb.
Artigo em Francês | MEDLINE | ID: mdl-25554662

RESUMO

BACKGROUND: Allgrove syndrome or "Triple A syndrome" involves adrenal insufficiency as a result of resistance to adrenocorticotropic hormone (ACTH), achalasia and alacrima, often associated with neurological signs. Herein, we report a new case of this rare genetic disease, which is of interest because of its dermatological mode of discovery. PATIENTS AND METHODS: A 4-year-old child, born to parents related by first-degree consanguinity, presented oral hyperpigmentation and diffused acquired melanoderma, as well as long-standing dry-eye syndrome. Laboratory tests confirmed low adrenal insufficiency. The combination of alacrima and adrenal insufficiency prompted screening for Allgrove syndrome, which was confirmed by genetic analysis showing homozygous c.1331+1G>A mutation within intron 14 of the gene encoding for ALADIN protein. Both parents were heterozygous for the same mutation. Two years later, the onset of vomiting raised concerns about achalasia, which was confirmed by oesophageal manometry. The child received symptomatic treatment consisting of supplementary hydrocortisone and oesophageal dilatation. DISCUSSION: The present case serves as a reminder that Allgrove syndrome may be diagnosed by dermatologists. Therapy is cross-disciplinary, being based upon medical treatment for adrenal insufficiency with prescription of artificial tears in the event of alacrima. Achalasia is treated by oesophageal dilatation or by surgery.


Assuntos
Insuficiência Adrenal/patologia , Acalasia Esofágica/patologia , Insuficiência Adrenal/genética , Pré-Escolar , Acalasia Esofágica/genética , Feminino , Humanos , Fenótipo
9.
Rev Mal Respir ; 39(5): 498-501, 2022 May.
Artigo em Francês | MEDLINE | ID: mdl-35570033

RESUMO

The relationship between infectious disease and therapy with immune checkpoint inhibitors remains unknown. We report the case of a 50-year-old woman with metastatic lung adenocarcinoma who responded remarkably well to immunotherapy and underwent upper right lobectomy. Three weeks after hospital discharge, she was readmitted for severe dyspnea due to mainstem bronchus compression by mediastinal mass. Histological analysis of transbronchial needle aspiration revealed A. fumigatus. After six months of voriconazole regimen, her symptoms improved with the regression of bronchial compression. Postoperative progression of pseudo-tumoral mass in patients treated with long-term immunotherapy may be related to opportunistic infectious disease and requires investigation.


Assuntos
Neoplasias Pulmonares , Mediastinite , Aspergillus , Feminino , Humanos , Imunoterapia , Pulmão/patologia , Neoplasias Pulmonares/complicações , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/cirurgia , Mediastinite/diagnóstico , Mediastinite/etiologia , Mediastinite/terapia , Pessoa de Meia-Idade
10.
Biotechnol Adv ; 56: 107916, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35122986

RESUMO

Growing concern regarding non-biodegradable plastics and the impact of these materials on the environment has promoted interest in biodegradable plastics. The intensification of separate biowastes collection in most European countries has also contributed to the development of biodegradable plastics, and the subject of their end-of-life is becoming a key issue. To date, there has been relatively little research to evaluate the biodegradability of biodegradable plastics by anaerobic digestion (AD) compared to industrial and home composting. However, anaerobic digestion is a particularly promising strategy for treating biodegradable organic wastes in the context of circular waste management. This critical review aims to provide an in-depth update of anaerobic digestion of biodegradable plastics by providing a summary of the literature regarding process performance, parameters affecting biodegradability, the microorganisms involved, and some of the strategies (e.g., pretreatment, additives, and inoculum acclimation) used to enhance the degradation rate of biodegradable plastics. In addition, a critical section is dedicated to suggestions and recommendations for the development of biodegradable plastics sector and their treatment in anaerobic digestion.


Assuntos
Plásticos Biodegradáveis , Gerenciamento de Resíduos , Anaerobiose , Morte , Humanos
11.
J Hosp Infect ; 120: 123-126, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34822950

RESUMO

Few data are available on the efficacy of 0.5% aqueous sodium hypochlorite (SH) for skin disinfection before peripheral catheter insertion. A total of 239 patients were randomly assigned to either one application of SH alone or one application of SH preceded by one application of 70% ethanol (ET-SH). Catheter colonization, defined as a catheter tip culture growing >1000 cfu of a micro-organism per millilitre, occurred in 29 patients (33% of 89 colonizations per 1000 catheter-days) in the SH group and in 31 patients (33% of 126 colonizations per 1000 catheter-days) in the ET-SH group.


Assuntos
Anti-Infecciosos Locais , Cateterismo Venoso Central , Catéteres , Desinfecção , Etanol/farmacologia , Humanos , Projetos Piloto , Pele , Hipoclorito de Sódio/farmacologia
12.
Drug Test Anal ; 14(11-12): 1984-1994, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34453778

RESUMO

The purpose of this pilot study was to investigate the effects of the transfusion of one erythrocyte concentrate on the number of circulating red blood cell extracellular vesicles (RBC-EVs) and their clearance time. Six, healthy volunteers donated their blood and were transfused with their RBC concentrate after 35-36 days of storage. One K2 EDTA and one serum sample were collected before donation, at four timepoints after donation and at another six timepoints after transfusion. RBC-EVs were analyzed on a Cytek Aurora flow cytometer. A highly significant increase (p < 0.001) of RBC-EVs from an average of 60.1 ± 19.8 (103 /µL) at baseline to 179.3 ± 84.7 (103 /µL) in the first 1-3 h after transfusion could be observed. Individual differences in the response to transfusion became apparent with one volunteer showing no increase and another an increased concentration at one timepoint after donation due to an influenza infection. We concluded that in an individualized passport approach, increased RBC-EVs might be considered as additional evidence when interpreting suspicious Athletes Biological Passport (ABPs) but for this additional research related to sample collection and transport processes as well as method development and harmonization would be necessary.


Assuntos
Dopagem Esportivo , Vesículas Extracelulares , Humanos , Projetos Piloto , Eritrócitos , Transfusão de Sangue
13.
Ann Oncol ; 19(11): 1875-81, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18641004

RESUMO

BACKGROUND: A relation between telomere attrition in early carcinogenesis and activation of DNA damage response (DDR) has been proposed. We explored telomere length and its link with DDR in colorectal multistep carcinogenesis. PATIENTS AND METHODS: We studied normal mucosa, low-grade dysplasia (LGD) and high-grade dysplasia (HGD) and invasive carcinoma (IC) in matched human colon specimens by evaluating p-ataxia telangiectasia mutated (ATM), p-checkpoint kinase 2 (Chk2), c-H2AX, TRF1 and TRF2 expressions by immunohistochemistry. FISH was used to assess telomere length. RESULTS: Telomeres shortened significantly from normal (N) to LGD and HGD (P < 0.0001; P = 0.012), then increased in length in IC (P = 0.006). TRF1 and TRF2 expressions were diminished from N to LGD and HGD (P = 0.004, P < 0.0001, ns) and were reexpressed at the invasive stage (P = 0.053 and P = 0.046). Phosphorylated ATM, Chk2 and H2AX appeared already in LGD (respectively, P = 0.001, P = 0.002 and P = 0.02). Their expression decreased from HGD to IC (respectively, P = 0.03, P = 0.02 and P = 0.37). These activating phosphorylations were inversely correlated with telomere length and TRF1/2 expression. CONCLUSION: In a model of colon multistep carcinogenesis, our data indicate that telomeric length and protein expression levels are inversely correlated with the activation of the DDR pathway.


Assuntos
Neoplasias Colorretais/genética , Dano ao DNA , Lesões Pré-Cancerosas/genética , Telômero/metabolismo , Telômero/patologia , Anticorpos Antineoplásicos/análise , Proteínas Mutadas de Ataxia Telangiectasia , Proteínas de Ciclo Celular/biossíntese , Quinase do Ponto de Checagem 2 , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Proteínas de Ligação a DNA/biossíntese , Regulação para Baixo , Células HT29 , Histonas/biossíntese , Humanos , Imuno-Histoquímica , Hibridização in Situ Fluorescente , Inclusão em Parafina , Lesões Pré-Cancerosas/metabolismo , Lesões Pré-Cancerosas/patologia , Proteínas Serina-Treonina Quinases/biossíntese , Proteínas de Ligação a Telômeros , Proteína 1 de Ligação a Repetições Teloméricas/biossíntese , Proteína 2 de Ligação a Repetições Teloméricas/biossíntese , Proteínas Supressoras de Tumor/biossíntese
14.
Rev Mal Respir ; 25(1): 50-8, 2008 Jan.
Artigo em Francês | MEDLINE | ID: mdl-18288051

RESUMO

INTRODUCTION: Several techniques for video-assisted pulmonary lobectomy have been reported. However full thoracoscopic lobectomy, i.e., without the help of a utility incision has seldom been performed. We report our results based on a series of resections for benign or metastatic conditions where mediastinal lymphadenectomy is not indicated. PATIENTS AND METHODS: Fifty-six patients (29 males and 27 females) with a mean age of 46 years (range: 8-82 years) had an attempted major pulmonary resection (54 lobectomies and 2 segmentectomies) via thoracoscopy alone for either a benign lesion (30 cases) or a metastasis (26 cases). RESULTS: There was no operative mortality. Six patients required conversion to thoracotomy (11%). In the 50 remaining patients who underwent an exclusively thoracoscopic operation, there was 1 intra-operative complication that was managed thoracoscopically. The duration of the procedure ranged from 65 to 230 minutes (mean: 157 minutes). Intra-operative blood loss was 55 cc (range: 0 to 200 cc) in the "metastasis group" and 109 cc (range: 0 to 280 cc) in the "benign lesion group". There were 5 postoperative complications (10%). Postoperative duration of stay ranged from 3 to 15 days (Mean: 6.7 days). All patients were seen at the first postoperative month and no clinical or radiological complication was noticed. CONCLUSION: Full thoracoscopic lobectomies are feasible and safe provided appropriate equipment is used and the surgical team is experienced in endoscopic surgery.


Assuntos
Pneumopatias/cirurgia , Pneumonectomia/métodos , Toracoscopia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Feminino , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias
15.
Rev Mal Respir ; 33(5): 343-9, 2016 May.
Artigo em Francês | MEDLINE | ID: mdl-26520776

RESUMO

INTRODUCTION: The objectives of outpatient surgery are to reduce the risks related to the hospitalization, to improve the postoperative recovery and to optimize contact with family physicians. The objective of this work is to present the first unit of outpatient pulmonary surgery and to report the results of the resections of pulmonary nodules in outpatient surgery in the setting of early discharge. METHODS: The indications for the resection of nodules were discussed in a multidisciplinary thoracic oncology meeting. The patients underwent resection of one or more lung nodules by thoracoscopy after verification that they met the anaesthetic and surgical criteria for ambulatory surgery. We analyzed the characteristics of the population, the duration of surgery, the type of resection, the time of the chest drain removal and the postoperative follow-up. RESULTS: Between November 2013 and December 2014, 51 patients underwent sub-lobar pulmonary resections. Among them 7 patients (4 men and 3 women), with an average age of 57.6 years (39-64) and histories of malignant tumor, underwent 7 atypical resections and two segmentectomies in outpatient surgery (3 patients had two resections). The average operating time was 53.75min (30-90). The chest drain was removed before the third hour in 8 cases and on the third day in one case. The average tumor diameter was 10.375mm (6-23). The histology revealed a metastasis of colorectal carcinoma in 4 cases, a metastasis of a renal carcinoma in 1 case, an in situ adenocarcinoma in 1 case and a benign tumor in 3 cases. Neither recurrence nor complication was observed during an average follow-up of 6 months. CONCLUSION: Thanks to a protocol of early mobilisation and discharge included in a well established clinical care pathway, thoracoscopic resection of lung nodules is feasible, with safety in properly selected and prepared patients in outpatient surgery.


Assuntos
Assistência Ambulatorial/métodos , Procedimentos Clínicos , Nódulos Pulmonares Múltiplos/cirurgia , Pneumonectomia/reabilitação , Cirurgia Torácica Vídeoassistida/reabilitação , Adulto , Procedimentos Clínicos/organização & administração , Procedimentos Clínicos/normas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nódulos Pulmonares Múltiplos/reabilitação , Duração da Cirurgia , Alta do Paciente , Pneumonectomia/métodos , Estudos Retrospectivos , Toracoscopia/métodos , Toracoscopia/reabilitação , Fatores de Tempo
16.
Am J Psychiatry ; 149(7): 924-30, 1992 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-1609873

RESUMO

OBJECTIVE: The authors investigated a possible cortical brain dysfunction associated with infantile autism. METHOD: They measured regional cerebral blood flow with single photon emission computed tomography (SPECT) and xenon-133 in 21 children with primary autism (according to DSM-III-R criteria). Five cortical brain areas including frontal, temporal, and sensory association cortices were examined in order to test the recent hypothesis of cerebral dysfunction in primary autism. Anatomical references for each subject were obtained with computerized tomography or magnetic resonance imaging and were used to delimit the regions of interest for SPECT analysis. RESULTS: When the results from the group with primary autism were compared with an age-matched group of nonautistic children with slight to moderate language disorders (N = 14), no cortical regional abnormalities were found. CONCLUSIONS: It appears that there is no regional cortical dysfunction in primary autism; however, in light of methodological limitations, one cannot exclude the possibility of more localized or subcortical brain dysfunctions in autism.


Assuntos
Transtorno Autístico/diagnóstico por imagem , Córtex Cerebral/irrigação sanguínea , Circulação Cerebrovascular , Tomografia Computadorizada de Emissão de Fóton Único , Transtorno Autístico/diagnóstico , Criança , Pré-Escolar , Diagnóstico Diferencial , Feminino , Humanos , Transtornos da Linguagem/diagnóstico , Transtornos da Linguagem/diagnóstico por imagem , Imageamento por Ressonância Magnética , Masculino , Tomografia Computadorizada por Raios X , Radioisótopos de Xenônio
17.
Arch Neurol ; 44(7): 715-8, 1987 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-3496075

RESUMO

Sixteen patients with stroke, five patients with permanent regressive ischemic neurologic deficit, and three patients with transient ischemic attacks were studied by single photon emission computed tomography performed within the first hour (early scan) and four hours (delayed scan) after injection of N-isopropyl-p-iodoamphetamine-iodine-123 (IMP). These patients were classified into three groups according to their clinical improvement three months later, and results of single photon emission computed tomography were compared with computed tomographic scan results and correlated to the clinical outcome. Regional brain hypoactivity of IMP differed in some cases between early and delayed IMP scans, showing in those cases a "redistribution" activity. The amplitude of this redistribution was significantly correlated with the clinical outcome of patients with stroke, whereas the value of hypoactivity on early IMP scan did not show such a correlation. The higher the redistribution amplitude was, the better was the clinical outcome. Comparative regional brain hypoactivity of IMP on early and delayed scans could represent a prognostic index of clinical recovery inasmuch as it gives information concerning viability of ischemic brain tissue.


Assuntos
Anfetaminas , Isquemia Encefálica/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Radioisótopos do Iodo , Tomografia Computadorizada de Emissão , Adulto , Idoso , Isquemia Encefálica/fisiopatologia , Feminino , Humanos , Iofetamina , Ataque Isquêmico Transitório/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Prognóstico , Fatores de Tempo
18.
J Nucl Med ; 36(12): 2169-74, 1995 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8523099

RESUMO

UNLABELLED: The aim of this work was to study cerebral function in vertically infected children with human immunodeficiency virus 1 (HIV-1). METHODS: PET with 18F-labeled fluorodeoxyglucose (FDG) was performed in eight children (2.5-5.5 yr): three with severe neurological symptoms and five without. Quantitative analysis was based on gray matter cortical and subcortical regions of interest for which glucose utilization was measured. RESULTS: Diffuse hypometabolism and subcortical hypermetabolism were found in the three children with severe neurological signs; the five other children had temporo-occipital cortical hypometabolism, mainly on the right side. CONCLUSION: Functional cerebral abnormalities seem to precede clinical symptoms in HIV-1infection of the brain in children.


Assuntos
Complexo AIDS Demência/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Desoxiglucose/análogos & derivados , Radioisótopos de Flúor , HIV-1 , Tomografia Computadorizada de Emissão , Síndrome da Imunodeficiência Adquirida/transmissão , Estudos de Casos e Controles , Pré-Escolar , Feminino , Fluordesoxiglucose F18 , Soropositividade para HIV , Humanos , Transmissão Vertical de Doenças Infecciosas , Masculino
19.
J Nucl Med ; 34(10): 1717-21, 1993 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8410289

RESUMO

A dopamine deficiency has been implicated in Rett syndrome, a progressive encephalopathy in girls that involves movement, tonus and cognitive disorders. To test the hypothesis that striatal D2 receptors increase in number in early stages of the disease, we measured the binding potential of 123I-Iodolisuride, a specific D2 ligand, in eleven Rett children aged 4-15 yr (7.9 +/- 3.5 yr) (mean +/- s.d.) and eight control subjects aged 3.5-13 yr (8.1 +/- 3.8 yr) who exhibited other neurological disorders. Regional cerebral blood flow (rCBF) was also measured with SPECT using 133Xe. The binding potential for 123I-ILIS and D2 receptors was significantly higher in Rett (0.45) than in controls (0.23) (p < 0.01). An increase in 123I-ILIS binding due to increased rCBF in patients' striata was excluded. Our results are consistent with a higher density of D2 receptors in young patients suffering from Rett syndrome because of reduced dopaminergic neurotransmission.


Assuntos
Corpo Estriado/diagnóstico por imagem , Corpo Estriado/metabolismo , Receptores de Dopamina D2/metabolismo , Síndrome de Rett/diagnóstico por imagem , Tomografia Computadorizada de Emissão de Fóton Único , Adolescente , Circulação Cerebrovascular , Criança , Pré-Escolar , Epilepsia/diagnóstico por imagem , Epilepsia/metabolismo , Epilepsia/fisiopatologia , Feminino , Humanos , Radioisótopos do Iodo , Lisurida/análogos & derivados , Imageamento por Ressonância Magnética , Masculino , Ensaio Radioligante , Síndrome de Rett/metabolismo , Síndrome de Rett/fisiopatologia
20.
J Nucl Med ; 33(5): 696-703, 1992 May.
Artigo em Inglês | MEDLINE | ID: mdl-1569478

RESUMO

Regional cerebral blood flow (rCBF) was studied by SPECT using 133Xe in 42 children, aged 2 days to 19 years, considered as neurologically normal. rCBF was measured on cortical regions and on the cerebellum and thalamus. Curves for reference values and standard deviation were defined for each region. At birth, cortical rCBFs were lower than those for adults; after birth they increased until 5 or 6 yr of age to values 50%-85% higher than those for adults and thereafter decreased, reaching adult levels between 15 and 19 yr. Neonatal values of rCBF on cerebellum and thalamus were slightly higher than adult level, but not significantly; after age 1, they followed the common pattern for cortical curves. When rCBFs were expressed in percent global CBF, they were lower at birth than adult levels in the cortex, then increased and reached a plateau corresponding to the adult value before the second year of age. The time needed to reach normal adult values differed for each cortical region. The shortest time was found on the primary cortex and the longest on the associative cortex. Cognitive development of the child seems to be related to changes in blood flow of the corresponding brain regions.


Assuntos
Encéfalo/diagnóstico por imagem , Circulação Cerebrovascular/fisiologia , Tomografia Computadorizada de Emissão de Fóton Único , Adolescente , Encéfalo/crescimento & desenvolvimento , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Valores de Referência , Radioisótopos de Xenônio
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