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1.
Nature ; 609(7925): 83-88, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-36045241

RESUMO

Classical mechanisms of volcanic eruptions mostly involve pressure buildup and magma ascent towards the surface1. Such processes produce geophysical and geochemical signals that may be detected and interpreted as eruption precursors1-3. On 22 May 2021, Mount Nyiragongo (Democratic Republic of the Congo), an open-vent volcano with a persistent lava lake perched within its summit crater, shook up this interpretation by producing an approximately six-hour-long flank eruption without apparent precursors, followed-rather than preceded-by lateral magma motion into the crust. Here we show that this reversed sequence was most likely initiated by a rupture of the edifice, producing deadly lava flows and triggering a voluminous 25-km-long dyke intrusion. The dyke propagated southwards at very shallow depth (less than 500 m) underneath the cities of Goma (Democratic Republic of the Congo) and Gisenyi (Rwanda), as well as Lake Kivu. This volcanic crisis raises new questions about the mechanisms controlling such eruptions and the possibility of facing substantially more hazardous events, such as effusions within densely urbanized areas, phreato-magmatism or a limnic eruption from the gas-rich Lake Kivu. It also more generally highlights the challenges faced with open-vent volcanoes for monitoring, early detection and risk management when a significant volume of magma is stored close to the surface.

2.
Eur J Med Genet ; 52(6): 386-92, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19635601

RESUMO

Cerebral proliferative glomeruloid vasculopathy (PGV) is a severe disorder of brain angiogenesis, resulting in abnormally thickened and aberrant perforating vessels, forming glomeruloids with inclusion-bearing endothelial cells. This peculiar vascular malformation was delineated by Fowler in 1972 as a stereotyped lethal fetal phenotype associating hydranencephaly-hydrocephaly with limb deformities, called Fowler syndrome (FS) or "proliferative vasculopathy and hydranencephaly-hydrocephaly" or "encephaloclastic proliferative vasculopathy" (OMIM#225790). In PGV, the disruptive impact of vascular malformation on the developing central nervous system (CNS) is now well admitted. However, molecular mechanisms of abnormal angiogenesis involving the CNS vasculature exclusively remain unknown, as no genes have been localized nor identified to date. We observed the pathognomonic FS vascular malformation in 16 fetuses, born to eight families, four consanguineous and four non-consanguineous. A diffuse form of PGV affecting the entire CNS and resulting in classical FS in 14 cases, can be contrasted to two cases with focal forms, confined to restricted territories of the CNS. Interestingly in PGV, immunohistological response to a marker of pericytes (SMA, Smooth in PGV Muscle Actin), was drastically reduced as compared to a match control. Our studies has expanded the description of FS to additional phenotypes, that could be called Fowler-like syndromes and suggest that the pathogenesis of PGV may be related to abnormal pericyte-dependent remodelling of the CNS vasculature, during CNS angiogenesis. Gene identification will determine the molecular basis of PGV and will help to know whether the Fowler-like phenotypes are due to the same underlying molecular mechanisms.


Assuntos
Vasos Sanguíneos/patologia , Encéfalo/irrigação sanguínea , Doenças Fetais/diagnóstico por imagem , Neovascularização Patológica , Aborto Induzido , Feminino , Humanos , Masculino , Gravidez , Resultado da Gravidez , Síndrome , Ultrassonografia
3.
Best Pract Res Clin Obstet Gynaecol ; 15(2): 323-31, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11358406

RESUMO

When a pregnant woman has been declared dead because of brain death or cerebral death and a permanent vegetative state, the life and wellbeing of her fetus become a matter of crucial consideration. The possible options are an immediate caesarean section, continuation of efforts to maintain the organ functions of the woman to allow her fetus to mature, or discontinuation of the woman's somatic organ support. The decisions depend on the viability of the fetus, the probable health status of the fetus, any wish expressed by the mother and the commitment of her next of kin. Maintaining the pregnancy in order for the fetus to become more mature requires counselling of the woman's partner or family members. Immediate recourse of caesarean section should be withheld if the fetus is too immature or has a probable poor health status. Terminally ill pregnant women may require treatments which are potentially harmful to their fetus. Medical abortion early in pregnancy or premature delivery later in pregnancy are the usually recommended options. When the fetus is viable although extremely premature, delivery should not be imposed on a woman concerned with the risk of leaving a possibly handicapped child after her death.


Assuntos
Morte Encefálica , Ética Médica , Cuidados Paliativos/métodos , Complicações na Gravidez/terapia , Aborto Terapêutico/psicologia , Adulto , Cesárea/psicologia , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Cuidados Paliativos/psicologia , Gravidez , Complicações na Gravidez/psicologia
4.
Psychosom Med ; 63(3): 502-4, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11382279

RESUMO

OBJECTIVE: Recent studies have indicated that the inflammatory cytokines could be implicated in anorexia nervosa and in its complications. To determinate the potential role of interleukins (IL-1, IL-2, IL-4, IL-6, IL-10), interferon (IFN gamma), tumor necrosis factor (TNF-alpha), and transforming growth factor (TGF-beta2) in anorexia nervosa, serum concentrations of these cytokines were measured in patients suffering from anorexia nervosa in comparison to healthy subjects. METHOD: Twenty-nine anorexic women according to DSM-IV criteria participated in the study. The control group consisted of 20 healthy women without eating disorders, mood disorders, and immunological disorders. RESULTS: We find that serum IL-2 and TGF-beta2 concentrations were both significantly decreased in anorexic patients, although the other cytokines did not differ significantly between the two groups. CONCLUSION: Our results show that in patients with anorexia nervosa, there are lower levels of specific cytokines (especially IL-2 and TGF-beta2). These levels may reflect the combination of impaired nutrition and weight loss, therefore, the dysregulation of these cytokines may contribute in anorexia's complications. Follow-up studies should examine the effects of parameters such as starvation, psychopathologic factors, and psychoneuroendocrinological perturbation which could affect interplay between cytokines, neuropeptides, and neurotransmitters.


Assuntos
Anorexia Nervosa/metabolismo , Citocinas/metabolismo , Adolescente , Adulto , Feminino , Humanos , Interleucina-2/sangue , Linfotoxina-alfa/sangue
5.
BJOG ; 108(12): 1251-4, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11843387

RESUMO

OBJECTIVE: To determine whether there is an association between early recurrent miscarriage (before 10 weeks of pregnancy) and Factor V Leiden and G20210A prothrombin mutations. DESIGN: A prospective study. SETTING: Department of Gynaecology and Obstetrics, Saint Antoine Hospital, Paris, France. POPULATION: Two groups of women: those with early unexplained recurrent miscarriage before 10 weeks of pregnancy (n = 260) and control healthy women without a previous history of thromboembolism (n = 240). METHODS: Screening for defects in the protein C anticoagulant pathway was performed using the anticoagulant response to agkistrodon confortrix venom (ACV test). Protein C and Factor V Leiden mutation testing was performed for each low ACV level. Each sample was tested for the G20210A prothrombin mutation. RESULTS: Factor V Leiden and G20210A mutations were found to be associated with early recurrent spontaneous miscarriage before 10 weeks of pregnancy, the odds ratios being 2.4 (95% CI 1-5) and 2.7 (95% CI 1-7), respectively. Similar results were found whether or not women had had a previous live birth. CONCLUSIONS: Early recurrent miscarriage before 10 weeks of pregnancy is significantly associated with Factor V or G20210A prothrombin mutations. These results indicate a possible role for anticoagulant prevention in these early miscarriages.


Assuntos
Aborto Habitual/genética , Fator V/genética , Mutação/genética , Protrombina/genética , Adulto , Feminino , Heterozigoto , Homozigoto , Humanos , Gravidez , Estudos Prospectivos , Fatores de Risco
6.
Ann Med Interne (Paris) ; 151 Suppl B: B20-6, 2000 Oct.
Artigo em Francês | MEDLINE | ID: mdl-11104940

RESUMO

Drug abuse, a general public health problem, concerns a growing number of the pregnant women. Pregnancy in a drug addict is a high risk condition. The prevention of neonatal and pediatric complications involving both organic and psychological conditions, requires early individual medical, psychological and social support adapted to each pregnant addict. The risk for the mother and the fetus warrant prescription of substitution therapy during pregnancy. Published results concerning pregnancies in women on substitution therapy have been encouraging and clearly show a decrease in maternal and fetal complications. These studies are however difficult to conduct and carry a certain number of biases related to the social and economical context of the patients and also to the type of drug abuse (multiple drugs, drug combinations, psychostimulants, smoking, alcohol).


Assuntos
Complicações na Gravidez , Transtornos Relacionados ao Uso de Substâncias , Anormalidades Induzidas por Medicamentos/etiologia , Aborto Espontâneo/etiologia , Adulto , Feminino , Retardo do Crescimento Fetal/induzido quimicamente , Infecções por HIV/complicações , Hepatite B/complicações , Hepatite C/complicações , Humanos , Recém-Nascido , Metadona/uso terapêutico , Entorpecentes/uso terapêutico , Síndrome de Abstinência Neonatal/diagnóstico , Trabalho de Parto Prematuro/etiologia , Gravidez , Complicações na Gravidez/diagnóstico , Complicações na Gravidez/reabilitação , Complicações Infecciosas na Gravidez/diagnóstico , Fatores de Risco , Transtornos Relacionados ao Uso de Substâncias/complicações , Transtornos Relacionados ao Uso de Substâncias/reabilitação
7.
Nature ; 408(6811): 457-60, 2000 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-11100724

RESUMO

Stress changes in the Earth's crust are generally estimated from model calculations that use near-surface deformation as an observational constraint. But the widespread correlation of changes of earthquake activity with stress has led to suggestions that stress changes might be calculated from earthquake occurrence rates obtained from seismicity catalogues. Although this possibility has considerable appeal, because seismicity data are routinely collected and have good spatial and temporal resolution, the method has not yet proven successful, owing to the non-linearity of earthquake rate changes with respect to both stress and time. Here, however, we present two methods for inverting earthquake rate data to infer stress changes, using a formulation for the stress- and time-dependence of earthquake rates. Application of these methods at Kilauea volcano, in Hawaii, yields good agreement with independent estimates, indicating that earthquake rates can provide a practical remote-sensing stress meter.

8.
Science ; 288(5475): 2343-6, 2000 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-10875914

RESUMO

After a magnitude 7.2 earthquake in 1975 and before the start of the ongoing eruption in 1983, deformation of Kilauea volcano was the most rapid ever recorded. Three-dimensional numerical modeling shows that this deformation is consistent with the dilation of a dike within Kilauea's rift zones coupled with creep over a narrow area of a low-angle fault beneath the south flank. Magma supply is estimated to be 0.18 cubic kilometers per year, twice that of previous estimates. The 1983 eruption may be a direct consequence of the high rates of magma storage within the rift zone that followed the 1975 earthquake.

9.
Psychiatry Res ; 87(1): 77-82, 1999 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-10512157

RESUMO

The autoantibodies that react with dopamine and serotonin are of interest in the study of bulimia nervosa. These neurotransmitters play an important role in appetite control, sexual and social behavior, and stress responses, all of which form a part of the clinical picture of bulimia nervosa. Are these autoantibodies involved in the serotoninergic hypofunctioning present in bulimia nervosa? Are they a part of an immunity regulation system essential for the cerebral system's homeostasis? To address these questions, 31 bulimic females (diagnosed according to DSM-III-R criteria) were compared with 10 control subjects (matched to the patients for sex, age, and demographic/psychosocial features). Measurement of the activity of natural autoantibodies reacting with dopamine, dopamine-beta-hydroxylase and serotonin was performed by an enzyme-linked immunosorbent assay (ELISA) for typical immunoglobulins (IgG, IgM, IgA). All of the autoantibodies of the IgG type were lower in the bulimic group than in the control group, a difference that was statistically significant for IgG anti-serotonin and IgG anti-dopamine. There was a trend for the amount of IgM anti-dopamine to be lower in patients than in controls. Dopamine and serotonin are specific components of brain cells. It can therefore be hypothesized that these antigens acting with autoantibodies could be the antigenic cerebral targets reacting with 'anti-brain' antibodies. The study of these specific autoantibodies provides information about the immunological characteristics that may be related to brain disturbances.


Assuntos
Autoanticorpos , Bulimia/imunologia , Dopamina/imunologia , Neuroimunomodulação/fisiologia , Serotonina/imunologia , Adulto , Autoanticorpos/análise , Autoanticorpos/imunologia , Bulimia/fisiopatologia , Estudos de Casos e Controles , Dopamina beta-Hidroxilase/imunologia , Feminino , Humanos , Imunoglobulina A/análise , Imunoglobulina M/análise , Estatísticas não Paramétricas
10.
Hum Reprod ; 14(8): 2106-9, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10438434

RESUMO

The objective of this study of patients with habitual abortion (HA), was to determine their autoimmune profile and to try to prevent new abortions using low-dose aspirin for 7 months with prednisone in the first trimester only, or with low-dose aspirin alone. A total of 678 healthy patients with three or more HA were investigated for antiphospholipid antibodies, antinuclear and antithyroid antibodies. Among these patients, 277 pregnant women were treated, 214 were given prednisone and aspirin (161 autoantibody-negative and 53 autoantibody-positive women), and 63 autoantibody-negative women received aspirin alone. Autoantibodies were present in 33.9% of the patients, in 82.6% of them anticardiolipin antibodies were found to be isolated or associated with antiprothrombin, antithyroid, circulating anticoagulant, antinuclear or anti-beta2 glycoprotein 1 antibodies. In autoantibody-negative pregnant women treated by prednisone and aspirin or aspirin alone, the success rate of live births was 90.7% (146 out of 161) and 74.6% (47 out of 63) respectively (P < 0.01). In autoantibody-positive patients treated with prednisone and aspirin the success rate was 84.9% (45 out of 53) (not significant). Prednisone and aspirin seemed to be as efficient in autoantibody-negative or positive women but better than aspirin alone in autoantibody-negative women. A double-blind trial is in progress to confirm these results.


Assuntos
Aborto Habitual , Anti-Inflamatórios não Esteroides/administração & dosagem , Anti-Inflamatórios/administração & dosagem , Aspirina/administração & dosagem , Autoimunidade , Prednisona/administração & dosagem , Aborto Habitual/imunologia , Aborto Habitual/prevenção & controle , Adulto , Anticorpos Antinucleares/imunologia , Anticorpos Antifosfolipídeos/imunologia , Feminino , Humanos , Gravidez , Resultado da Gravidez , Glândula Tireoide/imunologia
11.
Am J Reprod Immunol ; 42(1): 1-13, 1999 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10429761

RESUMO

PROBLEM: Th2 cytokines and Fas/Fas ligand interactions are proposed to be part of the placental barrier that contribute to the success of allogeneic pregnancy. To fully understand the role regulation of Th2 cytokines, we must isolate and identify the cells that produce them. We also need to assess the requirement for Fas/Fas ligand interaction in facilitating a successful allogeneic pregnancy. METHOD OF STUDY: To assess the site of production of Th2 cytokines, we used immunohistochemistry sections from placental and decidual tissue obtained at various stages of gestation in mice and humans. We used mice that are genetically deficient in Fas/Fas ligand interactions and raised specific anti-paternal CTLs by anti-paternal immunization of the mother before mating. RESULTS: The detailed results show that in both species the bulk of Th2 production may come from non-lymphoid tissues in the placenta and decidua, with a major role for trophoblasts. This raises questions about the mechanism(s) by which alloimmunization enhances local Th2 cytokine production. This issue is discussed. CONCLUSIONS: The success of allopregnancy in mice with circulating anti-paternal CTLs and deficient Fas/Fas ligand interactions rules out a mandatory role for such a mechanism in ensuring the success of allogeneic pregnancy.


Assuntos
Citocinas/biossíntese , Glicoproteínas de Membrana/metabolismo , Placenta/imunologia , Células Th2/imunologia , Trofoblastos/imunologia , Receptor fas/metabolismo , Animais , Decídua/imunologia , Decídua/metabolismo , Proteína Ligante Fas , Feminino , Humanos , Imuno-Histoquímica , Hibridização In Situ , Troca Materno-Fetal/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos CBA , Camundongos Endogâmicos DBA , Placenta/metabolismo , Gravidez , Baço
12.
Artigo em Francês | MEDLINE | ID: mdl-9265070

RESUMO

Looking for the etiology of hydramnios which became symptomatic at 21 weeks' gestation ultrasonography revealed a hepatic vascular abnormality without other symptoms. The suspected diagnosis was agenesis of the ductus venosus with creation of a high grade arteriovenous shunt between the umbilical vein and the inferior vena cava. Agenesis of the ductus venosus may be one expression of the different possible systemic-portal-umbilical abnormalities. Physiological consequences vary according to the type of substitutive anastomoses.


Assuntos
Feto/irrigação sanguínea , Fígado/irrigação sanguínea , Fígado/embriologia , Poli-Hidrâmnios/etiologia , Ultrassonografia Pré-Natal , Veias Umbilicais/anormalidades , Veia Cava Inferior/anormalidades , Adulto , Feminino , Humanos , Circulação Hepática , Gravidez , Segundo Trimestre da Gravidez , Veias Umbilicais/diagnóstico por imagem , Veia Cava Inferior/diagnóstico por imagem
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