Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 32
Filtrar
1.
Ann Oncol ; 35(6): 559-568, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38142939

RESUMO

BACKGROUND: Osteosarcoma stratification relies on clinical parameters and histological response. We developed a new personalized stratification using less invasive circulating tumor DNA (ctDNA) quantification. PATIENTS AND METHODS: Plasma from patients homogeneously treated in the prospective protocol OS2006, at diagnosis, before surgery and end of treatment, were sequenced using low-passage whole-genome sequencing (lpWGS) for copy number alteration detection. We developed a prediction tool including ctDNA quantification and known clinical parameters to estimate patients' individual risk of event. RESULTS: ctDNA quantification at diagnosis (diagCPA) was evaluated for 183 patients of the protocol OS2006. diagCPA as a continuous variable was a major prognostic factor, independent of other clinical parameters, including metastatic status [diagCPA hazard ratio (HR) = 3.5, P = 0.002 and 3.51, P = 0.012, for progression-free survival (PFS) and overall survival (OS)]. At the time of surgery and until the end of treatment, diagCPA was also a major prognostic factor independent of histological response (diagCPA HR = 9.2, P < 0.001 and 11.6, P < 0.001, for PFS and OS). Therefore, the addition of diagCPA to metastatic status at diagnosis or poor histological response after surgery improved the prognostic stratification of patients with osteosarcoma. We developed the prediction tool PRONOS to generate individual risk estimations, showing great performance ctDNA quantification at the time of surgery and the end of treatment still required improvement to overcome the low sensitivity of lpWGS and to enable the follow-up of disease progression. CONCLUSIONS: The addition of ctDNA quantification to known risk factors improves the estimation of prognosis calculated by our prediction tool PRONOS. To confirm its value, an external validation in the Sarcoma 13 trial is underway.


Assuntos
Biomarcadores Tumorais , Neoplasias Ósseas , DNA Tumoral Circulante , Osteossarcoma , Humanos , Osteossarcoma/genética , Osteossarcoma/sangue , Osteossarcoma/patologia , Osteossarcoma/cirurgia , Osteossarcoma/mortalidade , Osteossarcoma/diagnóstico , DNA Tumoral Circulante/genética , DNA Tumoral Circulante/sangue , Masculino , Feminino , Neoplasias Ósseas/genética , Neoplasias Ósseas/patologia , Neoplasias Ósseas/sangue , Neoplasias Ósseas/cirurgia , Neoplasias Ósseas/mortalidade , Adulto , Adolescente , Prognóstico , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/sangue , Estudos Prospectivos , Adulto Jovem , Criança , Variações do Número de Cópias de DNA , Gradação de Tumores , Pessoa de Meia-Idade , Sequenciamento Completo do Genoma , Intervalo Livre de Progressão
2.
Neurosci Biobehav Rev ; 127: 184-192, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33930472

RESUMO

Bipolar disorder (BD) and borderline personality disorder (BPD) are serious and prevalent psychiatric diseases that share common phenomenological characteristics: symptoms (such as anxiety, affective lability or emotion dysregulation), neuroimaging features, risk factors and comorbidities. While several studies have focused on the link between stress and peripheral inflammation in other affective disorders such as anxiety or depression, fewer have explored this relationship in BD and BPD. This review reports on evidence showing an interplay between immune dysregulation, anxiety and stress, and how an altered acute neuroendocrine stress response may exist in these disorders. Moreover, we highlight limitations and confounding factors of these existing studies and discuss multidirectional hypotheses that either suggest inflammation or stress and anxiety as the primum movens in BD and BPD pathophysiology, or inflammation as a consequence of the pathophysiology of these diseases. Untangling these associations and implementing a transdiagnostic approach will have diagnostic, therapeutic and prognostic implications for BD and BPD patients.


Assuntos
Transtorno Bipolar , Transtorno da Personalidade Borderline , Ansiedade , Transtornos de Ansiedade , Humanos , Inflamação
3.
Eur Psychiatry ; 34: 56-63, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26945530

RESUMO

BACKGROUND: Previous functional magnetic resonance imaging studies in bipolar disorder (BD) have evidenced changes in functional connectivity (FC) in brain areas associated with emotion processing, but how these changes vary with mood state and specific clinical symptoms is not fully understood. METHODS: We investigated resting-state FC between a priori regions of interest (ROIs) from the default-mode network and key structures for emotion processing and regulation in 27 BD patients and 27 matched healthy controls. We further compared connectivity patterns in subgroups of 15 euthymic and 12 non-euthymic patients and tested for correlations of the connectivity strength with measures of mood, anxiety, and rumination tendency. No correction for multiple comparisons was applied given the small population sample and pre-defined target ROIs. RESULTS: Overall, regardless of mood state, BD patients exhibited increased FC of the left amygdala with left sgACC and PCC, relative to controls. In addition, non-euthymic BD patients showed distinctive decrease in FC between right amygdala and sgACC, whereas euthymic patients showed lower FC between PCC and sgACC. Euthymic patients also displayed increased FC between sgACC and right VLPFC. The sgACC-PCC and sgACC-left amygdala connections were modulated by rumination tendency in non-euthymic patients, whereas the sgACC-VLPFC connection was modulated by both the current mood and tendency to ruminate. CONCLUSION: Our results suggest that sgACC-amygdala coupling is critically affected during mood episodes, and that FC of sgACC play a pivotal role in mood normalization through its interactions with the VLPFC and PCC. However, these preliminary findings require replication with larger samples of patients.


Assuntos
Transtorno Bipolar/fisiopatologia , Encéfalo/fisiopatologia , Vias Neurais/fisiopatologia , Adulto , Tonsila do Cerebelo/fisiopatologia , Transtorno Bipolar/psicologia , Mapeamento Encefálico/métodos , Estudos de Casos e Controles , Transtorno Ciclotímico/fisiopatologia , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Lobo Occipital/fisiopatologia
4.
Rev Med Suisse ; 10(444): 1835-7, 2014 Oct 01.
Artigo em Francês | MEDLINE | ID: mdl-25417342

RESUMO

Risk is an unavoidable "partner" of the life course for single home dwelling elderly, especially in the older age. The primary concerned person is not the only one to make decisions, his/her proxy and the community care professionals are also involved. Crisscrossing the point of view of these three types of actors with the same situation shows that risk is a notion which has to be problematized. Due to the large part of underlying life principles its understanding can't easily be objectified nor easy to reach by consensus. The three case studies presented suggest a dynamic grid of interpretation for an approach of risk concept.


Assuntos
Idoso , Serviços de Assistência Domiciliar , Apego ao Objeto , Características de Residência , Idoso de 80 Anos ou mais , Feminino , Serviços de Assistência Domiciliar/organização & administração , Serviços de Assistência Domiciliar/provisão & distribuição , Humanos , Relações Interpessoais , Aceitação pelo Paciente de Cuidados de Saúde/psicologia , Autonomia Pessoal , Risco
5.
Dalton Trans ; 40(45): 12028-32, 2011 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-21858343

RESUMO

Reaction of the Single Molecule Magnet [Mn(12)O(12)(CH(3)CO(2))(16)(H(2)O)(4)] (Mn(12)) with mesogenic dendritic ligands Li (i = 4, 5) quantitatively yields functional clusters [Mn(12)O(12)(Li-H)(16)(H(2)O)(4)] (i = 4, 5) that self-organize into a thermotropic SmA-type liquid crystalline phase. The perturbation of the molecular interface by methylation of the terminal mesogenic cyanobiphenyl groups induces a significant decrease of the clearing temperature without affecting the magnetic properties and the supramolecular organization of the Mn(12)-based clusters.

7.
Chirality ; 18(6): 406-12, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16575878

RESUMO

Circularly polarized luminescence (CPL) from selected transitions of Eu(III) in resolved single crystals of Na3[Eu(ODA)3].2NaClO4.6H2O are compared to CPL results obtained from solutions containing perturbed racemic mixtures of Eu(2,6-pyridine-dicarboxylate)3 (3-) and enantiomerically pure d-f helicate LambdaLambda-(-)EuCr(L8)3] in order to determine an empirical relationship between helicity and CPL spectra. Comparison of the CPL results, even for the magnetic dipole allowed transitions of Eu(III) where one measures large chiral discrimination, shows that the signs and magnitudes do not correlate with the overall helicity of the Eu(III) site. It is concluded that the symmetry of the Eu(III) site in LambdaLambda-(-)EuCr(L8)3 is not close enough to D3 to allow for the confirmation of the presumed spectra:structure correlation.

8.
Leukemia ; 19(12): 2082-9, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16121218

RESUMO

From 1989 to 1998, 341 children were included in the French multicentric LAME (Leucémie Aiguë Myéloblastique Enfant) trials. A total of 309 children were registered in the LAME 89/91 protocol. This intensive regimen included an induction phase (mitoxantrone plus cytarabine), two consolidation courses, one containing timed-sequential high-dose cytarabine, asparaginase and amsacrine; 276 (90%) achieved a CR. The 5-year overall survival (OS) and event-free survival (EFS) were 60+/-4 and 48+/-4%, respectively. From 1997, timed-sequencing of the LAME SP induction chemotherapy led to an unacceptable frequency of consolidation delay; future improvements are unlikely to come from further increases in intensity. The role of allogenic bone-marrow transplantation from an HLA-identical sibling in CR1 was examined. The disease-free survival (DFS) was 52+/-4% for non-allografted patients and 57+/-7% for allografted patients (P=NS); a better OS for allografted patients was shown and could be related either to allo-BMT early in CR1 or to a second allo-BMT in CR2. For the complete responders after consolidation therapy, the 5-year OS was significantly better in patients randomized for no maintenance therapy (MT-) than in patients randomized for MT (77.6+/-8 vs 59+/-8%; P=0.05), while the 5-year DFS was not significantly different. Exposure to low-dose MT might contribute to clinical drug resistance and treatment failure in relapsing patients.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Protocolos Antineoplásicos/normas , Leucemia Mieloide Aguda/terapia , Adolescente , Transplante de Medula Óssea , Criança , Pré-Escolar , Relação Dose-Resposta a Droga , Seguimentos , França , Humanos , Lactente , Recém-Nascido , Leucemia Mieloide Aguda/mortalidade , Indução de Remissão , Medição de Risco , Análise de Sobrevida , Resultado do Tratamento
10.
Pediatr Blood Cancer ; 43(7): 770-6, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15390280

RESUMO

OBJECTIVE: To develop an objective tool for assessing disease activity in patients with Langerhans cell histiocytosis (LCH). METHOD: Scoring system was developed and applied to a database containing information on 612 patients. RESULTS: At diagnosis, the score distribution was highly asymmetrical: the score was between 0 and 2 in 74% of cases, 3-6 in 16%, 7-10 in 3%, and more than 10 in 6%. The 5-year mortality rates were 1, 4.4, and 43.4%, respectively, among patients with initial scores of 0-2, 3-6, and >6. Stability or an increase of the score at 6 weeks was highly predictive of death among patients with initial scores above 6, while score stability had no significant impact on vital outcome among patients with low or moderate scores at diagnosis. CONCLUSIONS: This LCH disease activity score provides an objective tool for assessing disease severity, both at diagnosis and during follow-up and treatment.


Assuntos
Histiocitose de Células de Langerhans/diagnóstico , Índice de Gravidade de Doença , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Interpretação Estatística de Dados , Bases de Dados Factuais , Histiocitose de Células de Langerhans/tratamento farmacológico , Histiocitose de Células de Langerhans/mortalidade , Humanos , Valor Preditivo dos Testes , Distribuições Estatísticas , Análise de Sobrevida , Fatores de Tempo
11.
Bone Marrow Transplant ; 31(12): 1097-103, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12796789

RESUMO

The aim of this study was to assess the results of hematopoietic stem cell transplantation (HSCT) in refractory Langerhans cell histiocytosis (LCH). Among 85 patients with LCH and hematological dysfunction diagnosed in France between 1987 and 2000, eight received HSCT in six institutions. Median age at diagnosis was 0.54 years. The median LCH activity score at diagnosis was 10 (range 3-20). All patients responded poorly to initial chemotherapy. At the time of HSCT, the median activity score was 16.5 (range 7-18). HSCT was autologous in three cases and allogeneic in five cases. The conditioning regimen consisted of TBI in two cases and chemotherapy alone in six cases. Conditioning had to be attenuated in two patients. All patients had persistent active disease after autologous HSCT, which was fatal in two cases and controlled by chemotherapy in one case. After allogeneic HSCT, two patients died from toxicity and three had complete responses; two patients had had no recurrences after 21 months and 7 years of follow-up, while the other patient relapsed and died from sepsis related to splenectomy. HSCT for refractory LCH can thus be highly toxic but can also achieve sustained disease control.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Histiocitose de Células de Langerhans/terapia , Quimera , Feminino , França , Sobrevivência de Enxerto , Doença Enxerto-Hospedeiro/etiologia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Humanos , Lactente , Masculino , Prognóstico , Estudos Prospectivos , Estudos Retrospectivos , Condicionamento Pré-Transplante , Transplante Autólogo , Transplante Homólogo
12.
Stem Cells ; 20(5): 394-401, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12351810

RESUMO

Platelet-activating factor (PAF), a phospholipid mediator with a wide range of actions on mature leukocytes, acts through PAF-receptors (PAF-Rs) on the membranes of responsive cells. No results are available concerning the putative presence of PAF-Rs on leukemic blasts. Using multiparameter flow cytometry, we assessed intracellular and membrane PAF-Rs on blast cells of acute myeloid leukemic (AML) and acute lymphoid leukemic (ALL) patients. Membrane PAF-Rs were documented in 7/15 cases of ALL and 0/28 cases of AML. Putative intracellular PAF-Rs were found in blasts of 8/8 ALL and 13/13 AML patients. Vitamin D(3) and dimethyl sulfoxide that induced the expression of PAF-Rs on the membrane of the human promyelocytic leukemia cell line, HL60, failed to induce their expression on the membranes of CD34(+) AML blasts. The lack of membrane PAF-Rs on the membranes of AML blasts confirms that these receptors represent a marker of mature cells and that their membrane induction is a consequence of cell maturation and differentiation.


Assuntos
Membrana Celular/imunologia , Células-Tronco Hematopoéticas/imunologia , Líquido Intracelular/imunologia , Leucemia Linfoide/imunologia , Leucemia Mieloide Aguda/imunologia , Fator de Ativação de Plaquetas/imunologia , Glicoproteínas da Membrana de Plaquetas/imunologia , Receptores de Superfície Celular/imunologia , Receptores Acoplados a Proteínas G , Doença Aguda , Adulto , Idoso , Antígenos CD/imunologia , Antígenos CD34/imunologia , Antígenos de Diferenciação Mielomonocítica/imunologia , Biomarcadores Tumorais/imunologia , Biomarcadores Tumorais/metabolismo , Diferenciação Celular/imunologia , Membrana Celular/metabolismo , Feminino , Citometria de Fluxo , Células-Tronco Hematopoéticas/metabolismo , Humanos , Líquido Intracelular/metabolismo , Leucemia Linfoide/metabolismo , Leucemia Mieloide Aguda/metabolismo , Ativação Linfocitária/imunologia , Masculino , Fator de Ativação de Plaquetas/metabolismo , Glicoproteínas da Membrana de Plaquetas/metabolismo , Receptores de Superfície Celular/metabolismo , Lectina 3 Semelhante a Ig de Ligação ao Ácido Siálico
13.
Eur J Nutr ; 41(2): 54-60, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12083314

RESUMO

UNLABELLED: BACKGROUND Numerous studies have shown that dietary plant sterols (phytosterols and phytostanols) and their esters can decrease cholesterol absorption. However, few researchers have examined the effects of plant sterols on cholesterol absorption and synthesis using stable isotope tracers, instead of relying on endogenous pathway precursors. Further, we have worked with non-esterified lecithin-solubilized stanols as opposed to the more frequently studied esterified sterols and stanols. The vehicle was an oil-in-water liquid emulsion rather than the more common spread vehicle typically employed. AIM OF THE STUDY: To determine the effects of relatively low doses of lecithin-solubilized non-esterified stanols in liquid emulsions on cholesterol absorption and synthesis in mildly hypercholesterolemic subjects. METHODS: In a randomized, double blind crossover design, 12 mildly hypercholesterolemic men received either a free phytostanol supplement (3 g/d in 3 servings) or a control treatment for 3 days. Cholesterol endogenous synthesis rate was determined using the rate of incorporation of deuterium from body water into newly formed cholesterol molecules. Cholesterol absorption at the intestinal level was determined using the dual isotope method using 13C cholesterol injected intravenously and 180 cholesterol given orally. RESULTS: Cholesterol absorption was 55.7 +/- 6.5 % for the control and 33.5 +/- 5.3% for the phytostanol treatment. This massive reduction of the cholesterol absorption did not induce, on average, a difference in cholesterol endogenous synthesis which was measured at 0.074 +/- 0.0015 pool/d for plant sterols and 0.0736 +/- 0.0015 pool/d for controls (p > 0.05). CONCLUSIONS: The results demonstrated that lecithin-solubilized stanols administrated during a short period of time (3 days) in an oil-in-water emulsion can dramatically decrease cholesterol absorption, without a consistent, concomitant increase in synthesis, which is highly suggestive of effective LDL cholesterol lowering. The effects of synthesis should be verified in a longer study with more subjects.


Assuntos
Colesterol/biossíntese , Colesterol/farmacocinética , Hipercolesterolemia/tratamento farmacológico , Fitosteróis/farmacologia , Fitoterapia , Adulto , Isótopos de Carbono , Colesterol/sangue , LDL-Colesterol/sangue , LDL-Colesterol/efeitos dos fármacos , Estudos Cross-Over , Deutério , Suplementos Nutricionais , Método Duplo-Cego , Emulsões , Humanos , Hipercolesterolemia/metabolismo , Absorção Intestinal/efeitos dos fármacos , Cinética , Masculino , Pessoa de Meia-Idade , Isótopos de Oxigênio , Fitosteróis/uso terapêutico
14.
Chemistry ; 7(14): 3014-24, 2001 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-11495428

RESUMO

The segmental ligand 2-[6-(N,N-diethylcarbamoyl)pyridin-2-yl]-1,1'-dimethyl-5,5'-methylene-2'-(6-methylpyridine-2-yl)bis[1H-benzimidazole] (L3) reacts with a stoichiometric mixture of LnIII (Ln = La, Eu, Gd) and M(II) (M = Zn, Fe) in acetonitrile to produce selectively the heterodimetallic triple-stranded helicates (HHH)-[LnM(L3)3]5+. In these complexes, M(II) is pseudooctahedrally coordinated by the three wrapped bidentate binding units, thus forming a noncovalent tripod which organizes the three unsymmetrical tridentate segments to give ninefold coordination to LnIII. The introduction of a methyl group at the 6 position of the terminal pyridine in L3 sterically reduces the complexing ability of the bidentate segment for M(II). Spectroscopic (ESI-MS, UV/Vis/NIR, NMR), magnetic and electrochemical measurements show that 1) the head-to-head-to-head triple helical complexes (HHH)-[LnM(L3)3]5+ are quantitatively formed in solution only for ligand concentrations larger than 0.01 M, 2) FeII adopts a pure high-spin electronic configuration in (HHH)-[LnFe(L3)3]5+ and 3) the FeII/FeIII oxidation process is prevented by steric constraints. Detailed photophysical studies of (HHH)-[Eu-Zn(L3)3]5+ confirm that the pseudotricapped trigonal-prismatic lanthanide coordination site is not affected by the methyl groups bound to the terminal pyridine, thus leading to significant Eu-centered emission upon UV irradiation. In (HHH)-[EuFe(L3)3]5+, a resonant intramolecular Eu-->Fe(II)hs energy transfer partially quenches the Eu-centered luminescence; however, the residual red emission demonstrates that high-spin iron(II) is compatible with the sensitization of Eu(III) in heterodimetallic d-f complexes. The influence of the electronic configuration of Fe(II) on the efficiency of Eu(III)-->Fe(II) energy-transfer processes is discussed together with its consequence for the design of optically active spin-crossover supramolecular devices.

15.
Rapid Commun Mass Spectrom ; 15(14): 1207-13, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11445904

RESUMO

A number of dietary components and drugs are known to inhibit the absorption of dietary and biliary cholesterol, but at the same time can compensate by increasing cholesterol synthesis. It is, therefore, necessary to have a convenient and accurate method to assess both parameters simultaneously. Hence, we validated such a method in humans using on-line gas chromatography(GC)/combustion and GC/pyrolysis/isotope-ratio mass spectrometry (IRMS). Cholesterol absorption was measured using the ratio of [(13)C]cholesterol (injected intravenously) to [(18)O]cholesterol (administered orally). Simultaneously, cholesterol synthesis was measured using the deuterium incorporation method. Our methodology was applied to 12 mildly hypercholesterolemic men that were given a diet providing 2685 +/- 178 Kcal/day (mean +/- SD) and 255 +/- 8 mg cholesterol per day. Cholesterol fractional synthesis rates ranged from 5.0 to 10.5% pool/day and averaged 7.36% +/- 1.78% pool/day (668 +/- 133 mg/day). Cholesterol absorption ranged from 36.5-79.9% with an average value of 50.8 +/- 15.4%. These values are in agreement with already known data obtained with mildly hypercholesterolemic Caucasian males placed on a diet similar to the one used for this study. However, our combined IRMS method has the advantage over existing methods that it enables simultaneous measurement of cholesterol absorption and synthesis in humans, and is therefore an important research tool for studying the impact of dietary treatments on cholesterol parameters.


Assuntos
Colesterol/biossíntese , Cromatografia Gasosa-Espectrometria de Massas/métodos , Absorção Intestinal/fisiologia , Colesterol/análise , Colesterol na Dieta/análise , Humanos , Hipercolesterolemia/sangue , Isótopos , Masculino , Pessoa de Meia-Idade , Valores de Referência , Reprodutibilidade dos Testes
16.
Arch Pediatr ; 8(6): 614-6, 2001 Jun.
Artigo em Francês | MEDLINE | ID: mdl-11446184

RESUMO

UNLABELLED: Hodgkin's disease without peripheral lymphadenopathy or hepatosplenomegaly is exceptional. CASE REPORT: Hodgkin's disease was revealed by lung nodules, one of them cavitating, with mediastinal enlargement. Diagnosis was confirmed on a video-assisted pleuroscopic biopsy. CONCLUSION: Hodgkin's disease should be considered in case of mediastinal enlargement with lung nodules.


Assuntos
Doença de Hodgkin/patologia , Neoplasias Pulmonares/patologia , Adolescente , Biópsia , Diagnóstico Diferencial , Humanos , Masculino , Mediastino/patologia , Cirurgia Torácica Vídeoassistida
17.
Inorg Chem ; 40(12): 2642-51, 2001 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-11375674

RESUMO

The planar aromatic tridentate ligand 2,6-bis(1-S-neopentylbenzimidazol-2-yl)pyridine (L(11)) reacts with Ln(III) (Ln = La-Lu) in acetonitrile to give the successive complexes [Ln(L(11))(n)](3+) (n = 1-3). However, stability constants determined by spectrophotometry and NMR titrations show that formation of the tris complexes is not favored, log K(3) being around 1 for La(III) and Eu(III), while no such species could be evidenced for the smaller Lu(III) ion. The X-ray structures of L(11) (monoclinic, P2(1), a = 13.4850(12) A, b = 12.0243(11) A, c = 16.4239(14) A, beta = 103.747(7) degrees ), [La(ClO(4))(2)(L(11))(2)](3)[La(ClO(4))(2)(H(2)O)(L(11))(2)](ClO(4))(4).15MeCN (1a, monoclinic, P2(1), a = 21.765(4) A, b = 30.769(6) A, c = 21.541(5) A, beta = 116.01(3) degrees ), and [Eu(L(11))(3)](ClO(4))(3).4.28MeCN (5a, monoclinic, P1, a = 14.166(3) A, b = 19.212(4) A, c = 21.099(4) A, alpha = 108.91(3) degrees, beta = 98.22(3) degrees, gamma = 108.40(3) degrees ) have been solved. In 1a, two different types of complex cations are evidenced, both containing 10-coordinate La(III) ions. In the first type, both perchlorate anions are bidentate, while in the second type, one perchlorate is monodentate, the 10th coordination position being occupied by a water molecule. In 5a the three ligands are not equivalent. Ligands A and B are wrapped in a helical way and are mirror images of each other, while ligand C lies almost perpendicular to the two other ones. This stems from the steric hindrance generated by the bulky neopentyl groups with the consecutive loss of any stabilizing interstrand pi-stacking interactions. This explains the low stability of the tris complexes and the difficulty of isolating them and points to the importance of the steric factors in the design of self-assembled triple helical lanthanide-containing functional edifices [Ln(L(i))(3)](3+).


Assuntos
Benzimidazóis/química , Metais Terras Raras/química , Compostos Organometálicos/química , Piridinas/química , Benzimidazóis/síntese química , Benzimidazóis/isolamento & purificação , Cristalografia por Raios X , Metais Terras Raras/síntese química , Metais Terras Raras/isolamento & purificação , Conformação Molecular , Estrutura Molecular , Compostos Organometálicos/síntese química , Compostos Organometálicos/isolamento & purificação , Piridinas/síntese química , Piridinas/isolamento & purificação , Espectrofotometria , Termodinâmica
18.
Arch Pediatr ; 7(4): 388-90, 2000 Apr.
Artigo em Francês | MEDLINE | ID: mdl-10793926

RESUMO

UNLABELLED: Recurrent pancreatitis is seldom associated with CFTR (Cystic Fibrosis Transmembrane Regulator) gene mutation. CASE REPORT: A 17-year-old boy presented with isolated idiopathic pancreatitis. CFTR gene mutations study revealed delta F508 heterozygous mutation. CONCLUSION: Mutations for the CFTR gene should be explored in case of recurrent pancreatitis.


Assuntos
Regulador de Condutância Transmembrana em Fibrose Cística/genética , Fibrose Cística/genética , Pancreatite/etiologia , Doença Aguda , Adolescente , Fibrose Cística/complicações , Heterozigoto , Humanos , Masculino , Mutação Puntual , Recidiva
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA