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1.
Transpl Infect Dis ; 17(5): 751-5, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26432076

RESUMO

Multidrug-resistant (MDR) cytomegalovirus (CMV) emerged after transient responses to ganciclovir, foscarnet, and cidofovir in a CMV-seropositive recipient who underwent allogeneic hematopoietic stem cell transplantation from a CMV-seronegative donor. Experimental treatments using leflunomide and artesunate failed. Re-transplantation from a CMV-seropositive donor supported by adoptive transfer of pp65-specific T cells and maribavir was followed by lasting suppression. This case illustrates that successful MDR CMV therapy may require individualized multidisciplinary approaches.


Assuntos
Infecções por Citomegalovirus/terapia , Farmacorresistência Viral Múltipla , Transplante de Células-Tronco Hematopoéticas , Hospedeiro Imunocomprometido , Transferência Adotiva , Antivirais/uso terapêutico , Terapia Combinada , Infecções por Citomegalovirus/imunologia , Quimioterapia Combinada , Humanos , Masculino , Pessoa de Meia-Idade
2.
Am J Transplant ; 14(12): 2887-92, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25359127

RESUMO

A 15-year-old boy with a posterior urethral valve received a deceased donor kidney transplant (KT) in March 2011. Basiliximab induction followed by tacrolimus-based triple medication was used as immunosuppression. Eleven months after KT, the graft function deteriorated and the biopsy demonstrated interstitial nephritis suggestive of acute rejection. BK polyomavirus (BKPyV) surveillance in urine and plasma was negative. The patient received methylprednisolone pulses and anti-thymocyte globulin. Immunohistochemistry was positive for simian virus 40 (SV40) large T-antigen (LTag) in the biopsies, and quantitative polymerase chain reaction for JC polyomavirus (JCPyV) indicated high viral loads in urine and borderline levels in plasma. Immunosuppression was reduced and follow-up biopsies showed tubular atrophy and interstitial fibrosis. Two years after KT, antibody-mediated rejection resulted in graft loss and return to hemodialysis. Retrospective serologic work-up indicated a primary JCPyV infection with seroconversion first for IgM, followed by IgG, but no indication of BKPyV infection. In the SV40 LTag positive biopsies, JCPyV deoxyribonucleic acid (DNA) with archetype noncoding control region was detected, while BKPyV DNA was undetectable. To the best of our knowledge, this is the first reported case of primary JCPyV infection as the cause of PyV-associated nephropathy in KT.


Assuntos
Rejeição de Enxerto/etiologia , Falência Renal Crônica/cirurgia , Transplante de Rim , Nefrite Intersticial/virologia , Infecções por Polyomavirus/virologia , Infecções Tumorais por Vírus/virologia , Adolescente , DNA Viral/genética , Rejeição de Enxerto/diagnóstico , Humanos , Imunossupressores/uso terapêutico , Vírus JC/patogenicidade , Falência Renal Crônica/complicações , Falência Renal Crônica/virologia , Masculino , Nefrite Intersticial/diagnóstico , Infecções por Polyomavirus/complicações , Complicações Pós-Operatórias , Prognóstico , Diálise Renal , Infecções Tumorais por Vírus/complicações , Carga Viral
3.
Rev Med Suisse ; 10(445): 1866-70, 2014 Oct 08.
Artigo em Francês | MEDLINE | ID: mdl-25417356

RESUMO

Molecular diagnostics methods are not limited to specialized centers anymore. They play an important role for the diagnostic of infections commonly encountered in the clinical practice. Especially the detection of pathogens difficult to cultivate, such as viruses, has been greatly improved by these methods. Often, PCR has become the gold standard for the diagnostics of these pathogens. However, PCR cannot be used in any case, and it is not fail proof. Therefore, it is important to know when to use molecular methods and what are their strengths and weaknesses, in order to prescribe them rationally. This article reviews the characteristics of molecular tests and their main indications in the ambulatory setting.


Assuntos
Assistência Ambulatorial/métodos , Doenças Transmissíveis/diagnóstico , Técnicas de Diagnóstico Molecular/métodos , Prática Profissional , Assistência Ambulatorial/normas , Humanos , Técnicas Microbiológicas/métodos , Técnicas de Diagnóstico Molecular/normas , Patologia Molecular/métodos , Patologia Molecular/normas , Reação em Cadeia da Polimerase/métodos , Prática Profissional/normas , Manejo de Espécimes/normas
4.
Infection ; 40(6): 677-84, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22802096

RESUMO

BACKGROUND: The clinical characteristics of human metapneumovirus (hMPV)-associated lower respiratory tract infection (LRTI) after allogeneic hematopoietic stem cell transplantation (HSCT) is not well described. We describe the clinical course in eight HSCT recipients suffering from hMPV infection. METHODS: We prospectively included all patients with hMPV-associated LRTI after allogeneic HSCT during a period of 1 year. hMPV was diagnosed by multiplex polymerase chain reaction (PCR) from bronchoalveolar lavage (BAL). RESULTS: Eight patients with hMPV-associated LRTI were identified from 93 BAL samples. Three of the eight patients had co-infections with other pathogens. The median age of the patients was 45 years [interquartile range (IQR) 36.8-53.5], the median time posttransplant was 473 days (IQR 251-1,165), 5/8 patients had chronic graft-versus-host disease (cGvHD), and 6/8 patients received immunosuppression. Chest computed tomography (CT) scanning showed a ground-glass pattern in 7/8 patients. Seven of eight patients required hospitalization due to severe symptoms and hypoxemia. All were treated with intravenous immunoglobulin (IVIG), which was combined with oral ribavirin in six patients. The mortality rate was 12.5 % (1/8). CONCLUSIONS: hMPV-associated LRTI in allogeneic HSCT recipients are not uncommon and present with unspecific respiratory symptoms, ground-glass pattern in CT scanning, and co-infection.


Assuntos
Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Metapneumovirus/isolamento & purificação , Infecções por Paramyxoviridae/etiologia , Infecções Respiratórias/etiologia , Adulto , Antivirais/uso terapêutico , Quimioterapia Combinada , Feminino , Humanos , Hospedeiro Imunocomprometido , Imunoglobulinas Intravenosas/uso terapêutico , Masculino , Pessoa de Meia-Idade , Infecções por Paramyxoviridae/diagnóstico , Infecções por Paramyxoviridae/tratamento farmacológico , Infecções Respiratórias/diagnóstico , Infecções Respiratórias/tratamento farmacológico , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Ribavirina/uso terapêutico , Tomografia Computadorizada por Raios X , Transplante Homólogo
5.
J Clin Microbiol ; 49(4): 1382-8, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21325560

RESUMO

PCR-based molecular assays have a central role in polyomavirus diagnostics. To assure optimal performance, target sequences should be regularly updated according to newly available sequences. The aim of this study was to review our in-house polyomavirus BK (BKV) and JC (JCV) real-time PCR assays. Database analysis revealed variations in the BKV target region which might affect the assay performance, while no significant changes were found in the JCV target region. We compared two degenerate versions of our BKV primers which accommodated at least 95% of all published genetic variants. Dilutions of cloned viral genomic DNA and probit analysis indicated an analytical sensitivity of the updated BKV assay of 4.15 copies/reaction and that of the JCV assay was 3.37 copies/reaction. The specificity was assessed by testing JCV- and BKV-positive samples that showed no cross-reactivity. The performance of the original and updated BKV assay was compared in 101 urine and 200 plasma samples submitted to our routine diagnostic laboratory revealed similar quantitative results. We conclude that our JCV and updated BKV real-time PCR assays are robust and detect rare variants possibly encountered in the clinical routine.


Assuntos
Vírus BK/isolamento & purificação , Vírus JC/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , Polimorfismo Genético , Infecções por Polyomavirus/diagnóstico , Infecções por Polyomavirus/virologia , Virologia/métodos , Adulto , Vírus BK/genética , Primers do DNA/genética , Feminino , Humanos , Vírus JC/genética , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade
6.
J Neurosci ; 20(5): 1837-48, 2000 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-10684885

RESUMO

Disturbances of the serotoninergic neuromodulation in the cerebellar cortex have been involved in several types of ataxia, but the physiological action of serotonin in this structure remains poorly understood. We report that in slices of the rat cerebellar vermis, serotonin triggers the firing of an inhibitory interneuron presynaptic to Golgi cells. The Lugaro cell, a neglected interneuronal type, satisfies the expected criteria for this input, whereas basket cells, stellate cells, or Golgi cells do not. Lugaro cells are selectively excited by serotonin, and their firing behavior (sustained steady frequency in the 5-15 Hz range) resembles the pattern of occurrence of serotonin-evoked IPSCs in Golgi cells. Immunohistochemical stainings and single cell reconstructions show that Lugaro cell axons form a parasagittal plexus but also extend long transverse branches that run parallel to the parallel fibers and are partly myelinated. Electrophysiological data suggest that these transverse axons participate in synaptic contacts of the Lugaro cells with Golgi cells, and we calculated that in the intact cerebellum a given Lugaro cell contacts >100 Golgi cells. Serotonin modulation of Lugaro cells may constitute an intracortical switch involved in information patterning at the level of Golgi cells and granule cells populations, and particularly in synchronizations recorded along the transverse axis in vivo.


Assuntos
Córtex Cerebelar/fisiologia , Inibição Neural/fisiologia , Serotonina/fisiologia , 6-Ciano-7-nitroquinoxalina-2,3-diona/farmacologia , Potenciais de Ação/efeitos dos fármacos , Potenciais de Ação/fisiologia , Animais , Calbindina 2 , Córtex Cerebelar/química , Antagonistas de Aminoácidos Excitatórios/farmacologia , Interneurônios/química , Interneurônios/fisiologia , Interneurônios/ultraestrutura , Masculino , Fibras Nervosas Mielinizadas/química , Fibras Nervosas Mielinizadas/fisiologia , Inibição Neural/efeitos dos fármacos , Técnicas de Patch-Clamp , Ratos , Ratos Wistar , Proteína G de Ligação ao Cálcio S100/análise , Serotonina/farmacologia , Transmissão Sináptica/efeitos dos fármacos , Transmissão Sináptica/fisiologia
7.
J Neurosci ; 21(16): 6045-57, 2001 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-11487628

RESUMO

In the rat cerebellum, Golgi cells receive serotonin-evoked inputs from Lugaro cells (L-IPSCs), in addition to spontaneous inhibitory inputs (S-IPSCs). In the present study, we analyze the pharmacology of these IPSCs and show that S-IPSCs are purely GABAergic events occurring at basket and stellate cell synapses, whereas L-IPSCs are mediated by GABA and glycine. Corelease of the two transmitters at Lugaro cell synapses is suggested by the fact that both GABA(A) and glycine receptors open during individual L-IPSCs. Double immunocytochemical stainings demonstrate that GABAergic and glycinergic markers are coexpressed in Lugaro cell axonal varicosities, together with the mixed vesicular inhibitory amino acid transporter. Lugaro cell varicosities are found apposed to glycine receptor (GlyR) clusters that are localized on Golgi cell dendrites and participate in postsynaptic complexes containing GABA(A) receptors (GABA(A)Rs) and the anchoring protein gephyrin. GABA(A)R and GlyR/gephyrin appear to form segregated clusters within individual postsynaptic loci. Basket and stellate cell varicosities do not face GlyR clusters. For the first time the characteristics of GABA and glycine cotransmission are compared with those of GABAergic transmission at identified inhibitory synapses converging onto the same postsynaptic neuron. The ratio of the decay times of L-IPSCs and of S-IPSCs is a constant value among Golgi cells. This indicates that, despite a high cell-to-cell variability of the overall IPSC decay kinetics, postsynaptic Golgi cells coregulate the kinetics of their two main inhibitory inputs. The glycinergic component of L-IPSCs is responsible for their slower decay, suggesting that glycinergic transmission plays a role in tuning the IPSC kinetics in neuronal networks.


Assuntos
Sistemas de Transporte de Aminoácidos Neutros , Sistemas de Transporte de Aminoácidos , Cerebelo/metabolismo , Glicina/metabolismo , Inibição Neural/fisiologia , Sinapses/metabolismo , Proteínas de Transporte Vesicular , Ácido gama-Aminobutírico/metabolismo , Animais , Proteínas de Transporte/metabolismo , Cerebelo/citologia , Estimulação Elétrica , Feminino , Antagonistas GABAérgicos/farmacologia , Antagonistas de Receptores de GABA-A , Proteínas da Membrana Plasmática de Transporte de Glicina , Técnicas In Vitro , Cinética , Masculino , Potenciais da Membrana/efeitos dos fármacos , Potenciais da Membrana/fisiologia , Rede Nervosa/metabolismo , Inibição Neural/efeitos dos fármacos , Técnicas de Patch-Clamp , Ratos , Ratos Sprague-Dawley , Ratos Wistar , Receptores de GABA-A/metabolismo , Receptores de Glicina/antagonistas & inibidores , Receptores de Glicina/metabolismo , Serotonina/farmacologia , Estricnina/farmacologia , Proteínas Vesiculares de Transporte de Aminoácidos Inibidores
8.
Minerva Anestesiol ; 81(10): 1079-85, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25697881

RESUMO

BACKGROUND: Augmented renal clearance (ARC) or renal hyperfiltration is increasingly reported in intensive care unit (ICU) patients. The goal of this analysis was to study the epidemiology of ARC in a cohort of mixed ICU patients METHODS: Single center retrospective cohort study of adult ICU patients (12/2008-2/2010). When data were available, urinary creatinine clearance (CLCR) was calculated for all patients throughout their ICU stay. ARC was defined as a body surface adjusted CLCR≥130 mL/min/1.73m2. We sought to study the incidence of ARC and identify patient characteristics associated with ARC. RESULTS: A total of 1081 patients were included in the analysis, generating 4472 ICU patient days. Median age was 62 y (IQR 50-72), and 63% were male. The initial CLCR was 86 (39-151) mL/min and the maximal CLCR was 145 (76-237) mL/min. ARC occurred in 55.8% of patients, and was about as frequent in men and women (37%% vs. 35%%, P=0.73). Patients with ARC were younger (57 vs. 67 years, P<0.001) and were less frequently treated with vasopressors (27% vs. 39%, P<0.01). ARC incidence was 36.6 ARC days per 100 ICU days. ARC throughout the ICU stay occurred in 32.8% of patients. CONCLUSION: ARC was a frequent finding in this cohort of ICU patients, with more than half of the patient expressing ARC at least once during their ICU stay, and an incidence of 36.6 ARC days/100 patient days.


Assuntos
Injúria Renal Aguda/terapia , Cuidados Críticos/métodos , Hemofiltração/estatística & dados numéricos , Injúria Renal Aguda/epidemiologia , Idoso , Estudos de Coortes , Feminino , Humanos , Incidência , Testes de Função Renal , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
9.
Protein Sci ; 7(3): 673-80, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9541399

RESUMO

One of the main difficulties with blood substitutes based on hemoglobin (Hb) solutions is the auto-oxidation of the hemes, a problem aggravated by the dimerization of Hb tetramers. We have employed a method to study the oxyHb tetramer-dimer equilibrium based on the rate of auto-oxidation as a function of protein concentration. The 16-fold difference in dimer and tetramer auto-oxidation rates (in 20 mM phosphate buffer at pH 7.0, 37 degrees C) was exploited to determine the fraction dimer. The results show a transition of the auto-oxidation rate from low to high protein concentrations, allowing the determination of the tetramer-dimer dissociation coefficient K4,2 = [Dimer] 2/[Tetramer]. A 14-fold increase in K4,2 was observed for addition of 10 mM of the allosteric effector inositol hexaphosphate (IHP). Recombinant hemoglobins (rHb) were genetically engineered to obtain Hb with a lower oxygen affinity than native Hb (Hb A). The rHb alpha2beta2 [(C7) F41Y/(G4) N102Y] shows a fivefold increase in K4,2 at pH 7.0, 37 degrees C. An atmosphere of pure oxygen is necessary in this case to insure fully oxygenated Hb. When this condition is satisfied, this method provides an efficient technique to characterize both the tetramer-dimer equilibrium and the auto-oxidation rates of various oxyHb. For low oxygen affinity Hb equilibrated under air, the presence of deoxy subunits accelerates the auto-oxidation. Although a full analysis is complicated, the auto-oxidation studies for air equilibrated samples are more relevant to the development of a blood substitute based on Hb solutions. The double mutants, rHb alpha2beta2 [(C7) F41Y/(G4) N102A] and rHb alpha2beta2 [(C7) F41Y/(E10) K66T], show a lower oxygen affinity and a higher rate of oxidation than Hb A. Simulations of the auto-oxidation rate versus Hb concentration indicate that very high protein concentrations are required to observe the tetramer auto-oxidation rate. Because the dimers oxidize much more rapidly, even a small fraction dimer will influence the observed oxidation rate.


Assuntos
Oxiemoglobinas/química , Adulto , Regulação Alostérica , Dimerização , Compostos Férricos/química , Compostos Ferrosos/química , Haptoglobinas/química , Humanos , Ligação de Hidrogênio , Lisina , Substâncias Macromoleculares , Oxirredução , Fenilalanina , Proteínas Recombinantes , Relação Estrutura-Atividade
10.
Protein Sci ; 1(1): 145-50, 1992 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-1363932

RESUMO

Models for the structure of the fibers of deoxy sickle cell hemoglobin (Hb Hb S, beta 6 Glu-->Val) have been obtained from X-ray and electron microscopic studies. Recent molecular dynamics calculations of polymer formation give new insights on the various specific interactions between monomers. Site-directed mutagenesis with expression of the Hb S beta subunits in Escherichia coli provides the experimental tools to test these models. For Hb S, the beta 6 Val residue is intimately involved in a specific lateral contact, at the donor site, that interacts with the acceptor site of an adjacent molecule composed predominantly of the hydrophobic residues Phe 85 and Leu 88. Comparing natural and artificial mutants indicates that the solubility of deoxyHb decreases in relation to the surface hydrophobicity of the residue at the beta 6 position with Ile > Val > Ala. We also tested the role of the stereospecific adjustment between the donor and acceptor sites by substituting Trp for Glu at the beta 6 location. Among these hydrophobic substitutions and under our experimental conditions, only Val and Ile were observed to induce polymer formation. The interactions for the Ala mutant are too weak whereas a Trp residue inhibits aggregation through steric hindrance at the acceptor site of the lateral contact. Increasing the hydrophobicity at the axial contact between tetramers of the same strand also contributes to the stability of the double strand. This is demonstrated by associating the beta 23 Val-->Ile mutation at the axial contact with either the beta 6 Glu-->Val or beta 6 Glu-->Ile substitution in the same beta subunit.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Hemoglobina Falciforme/química , Hemoglobina Falciforme/genética , Conformação Proteica , Alanina/química , Alanina/genética , Escherichia coli/genética , Glutamatos/química , Glutamatos/genética , Ácido Glutâmico , Humanos , Isoleucina/química , Isoleucina/genética , Mutagênese Sítio-Dirigida , Oxigênio/metabolismo , Engenharia de Proteínas , Proteínas Recombinantes/química , Solubilidade , Relação Estrutura-Atividade , Valina/química , Valina/genética
11.
Protein Sci ; 5(1): 114-20, 1996 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8771203

RESUMO

Based on the properties of two low oxygen affinity mutated hemoglobins (Hb), we have engineered a double mutant Hb (rHb beta YD) in which the beta F41Y substitution is associated with K82D. Functional studies have shown that the Hb alpha 2 beta 2(C7)F41Y exhibits a decreased oxygen affinity relative to Hb A, without a significantly increased autooxidation rate. The oxygen affinity of the natural mutant beta K82D (Hb Providence-Asp) is decreased due to the replacement of two positive charges by two negative ones at the main DPG-binding site. The functional properties of both single mutants are interesting in the view of obtaining an Hb-based blood substitute, which requires: (1) cooperative oxygen binding with an overall affinity near 30 mm Hg at half saturation, at 37 degrees C, and in the absence of 2,3 diphosphoglycerate (DPG), and (2) a slow rate of autooxidation in order to limit metHb formation. It was expected that the two mutations were at a sufficient distance (20 A) that their respective effects could combine to form low oxygen affinity tetramers. The double mutant does display additive effects resulting in a fourfold decrease in oxygen affinity; it can insure, in the absence of DPG, an oxygen delivery to the tissues similar to that of a red cell suspension in vivo at 37 degrees C. Nevertheless, the rate of autooxidation, 3.5-fold larger than that of Hb A, remains a problem.


Assuntos
Hemoglobinas/genética , Mutação , Oxigênio/metabolismo , Hemoglobinas/metabolismo , Cinética , Oxirredução , Ligação Proteica , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo
12.
FEBS Lett ; 374(1): 39-42, 1995 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-7589508

RESUMO

In the stereochemical model proposed by Perutz [1], the Fe-His(F8) bond plays a significant role in the allosteric transition in hemoglobin and the resulting cooperativity in ligand binding. When this bond is ruptured, there is a loss in the transmission of the information concerning ligand binding; examples are Hb(NO)4 in the presence of inositol hexakisphosphate (IHP), or nickel substituted Hb hybrids which, despite being liganded, exhibit deoxy-like properties. To study the effects of the loss of the iron proximal histidine bond, we have engineered the alpha 2 beta 2(F8)H92A recombinant Hb. The replacement of the highly conserved proximal histidine F8 residue by an alanine results in a low affinity for the heme group and a loss of the allosteric properties; kinetics of CO recombination after photodissociation show only the rapid bimolecular phase, characteristic of the high affinity R-state. However, a significant amount of deoxy (T-state) kinetics are observed after addition of external effectors such as IHP. The iron-histidine bond is apparently crucial for the heme-heme interaction, but the allosteric equilibrium may still be influenced by external constraints.


Assuntos
Sítio Alostérico , Hemoglobinas/química , Alanina/química , Sítio Alostérico/efeitos dos fármacos , Hemoglobinas/genética , Histidina/química , Imidazóis/farmacologia , Mutagênese Sítio-Dirigida , Compostos de Fenilureia/farmacologia , Ácido Fítico/farmacologia , Proteínas Recombinantes de Fusão/química
13.
J Comp Neurol ; 377(4): 550-64, 1997 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-9007192

RESUMO

Amyloid precursor protein (APP) is a transmembrane glycoprotein which is believed to promote neural cell adhesion, neural survival, and neuritogenesis. The present study was undertaken to determine whether APP could be detected within different types of astroglial cells present in the central nervous system (CNS) of neonatal or adult rats. The localization of this protein within glial cells was studied by using a monoclonal antibody (Mab22C11) that recognizes all APP isoforms and in addition cross-reacts with APP-like proteins. In the brain of neonatal rats, Mab22C11 immunostaining was associated with numerous elongated radial glia-like structures. In the intact brain and spinal cord of adult rats, Mab22C11 immunostaining was associated with (i) numerous neuron-like structures and (ii) glial structures immunostained for glial fibrillary acidic protein (GFAP) and/or vimentin, including tanycytes mostly located in the mediobasal hypothalamus, fibrous astrocytes located in the white matter and ependymocytes bordering the ventricles. On the other hand, all the GFAP-immunostained astrocytes located in the grey matter were Mab22C11 negative. In the lesioned brain and spinal cord of adult rats, Mab22C11 immunostaining was associated with intensely GFAP-immunostained reactive astrocytes located close to a surgical lesion, but not with those induced by Wallerian degeneration that appear at a distance from a lesion. Electron microscopic observations further indicated that in all these labeled astroglial cells, Mab22C11 immunostaining was mainly localized to the limiting plasma membrane and the membrane of intracytoplasmic cisternae and vesicles. These data indicate that Mab22C11 antibody induces strong immunostaining of specific astroglial cells of the neonatal and adult rat CNS that support axonal outgrowth, therefore suggesting that an APP-like protein associated with these cells participates in their axonal outgrowth promoting properties.


Assuntos
Precursor de Proteína beta-Amiloide/imunologia , Astrócitos/química , Axônios/fisiologia , Encéfalo/metabolismo , Regeneração Nervosa/fisiologia , Proteínas do Tecido Nervoso/análise , Animais , Animais Recém-Nascidos , Anticorpos Monoclonais , Especificidade de Anticorpos , Western Blotting , Encéfalo/fisiologia , Encéfalo/ultraestrutura , Masculino , Microscopia Confocal , Ratos , Ratos Sprague-Dawley
14.
Neuroscience ; 95(1): 173-82, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10619473

RESUMO

Transection of the spinal cord yields a permanent deficit due to the interruption of descending and ascending tracts which subserve the supraspinal control of spinal cord functions. We have shown previously that transplantation below the level of the section of embryonic monoaminergic neurons can promote the recovery of some segmental functions via a local serotonergic and noradrenergic reinnervation. Moreover, the up-regulation of the corresponding receptors resulting from the section was corrected by the transplants. The aim of the present work was to determine whether such a graft could also influence non-monoaminergic local neurons, the GABAergic interneurons of the spinal cord. Following spinal cord transection, the number of cells which express glutamate decarboxylase (mol. wt 67,000) messenger RNA--a marker of GABA synthesis--increased significantly below the lesion compared with the intact animal. In contrast, in lesioned animals which had been grafted one week later with raphe neuroblasts, this number was close to control level. These post-grafting modifications were further associated with increased GABA immunoreactivity in the host tissue. These data suggest that the graft of embryonic raphe cells which compensates the deficit of serotonin in the distal segment also regulates the expression of the GABAergic phenotype in the host spinal cord. This regulation could be mediated by the re-establishment of a local functional innervation by both serotonin and GABAergic transplanted neurons and/or by trophic factors released from the embryonic cells. It appears then that grafted cells influence the host tissue in a complex manner, through the release and/or regulation of several neurotransmitter systems.


Assuntos
Transplante de Células , Transplante de Tecido Fetal , Núcleos da Rafe/embriologia , Traumatismos da Medula Espinal/fisiopatologia , Traumatismos da Medula Espinal/cirurgia , Ácido gama-Aminobutírico/metabolismo , Animais , Embrião de Mamíferos/citologia , Feminino , Imuno-Histoquímica , Hibridização In Situ , Interneurônios/fisiologia , Fenótipo , Núcleos da Rafe/citologia , Ratos , Ratos Sprague-Dawley , Medula Espinal/metabolismo , Traumatismos da Medula Espinal/genética , Traumatismos da Medula Espinal/patologia
16.
J Nephrol ; 12(1): 18-23, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10202998

RESUMO

Among other neuropeptides and neurohormones, growth hormone (GH) and somatostatin (SRIF) have been shown to modulate the development of glomerular injury in various renal diseases. In particular, GH is implicated in the induction of glomerular hypertrophy and sclerosis in partial nephrectomy and diabetic nephropathy. While GH effects on glomerular hypertrophy are likely mediated by insulin-like growth factor I (IGF-I), GH effects on glomerular sclerosis are independent of IGF-I. Those effects rather require multiple signaling pathways functioning in series, e.g. angiotensin II binding preceding transforming growth factor beta (TGF-beta) release, or pro-inflammatory factor release preceding repair/scarring processes. In contrast with GH, SRIF administration prevents the development of glomerular lesions in experimental diabetes, partial nephrectomy and immune glomerulonephritis. Inhibitory effects of SRIF on glomerular hypotrophy may be through a decrease in GH secretion and/or IGF-I expression or through a direct blockade of glomerular cell proliferation. The mechanisms underlying the anti-inflammatory effects of SRIF are most likely a deactivation of inflammatory cells related in part to an upregulated response of these cells to glucocorticoids. Additional studies will be required to further define the role of GH and SRIF in the development of glomerular injury and, hence, to identify new targets for a therapeutic approach in glomerular diseases.


Assuntos
Nefropatias Diabéticas , Glomerulonefrite/etiologia , Hormônio do Crescimento Humano/fisiologia , Glomérulos Renais , Somatostatina/fisiologia , Humanos , Fator de Crescimento Insulin-Like I/fisiologia
17.
Transfus Clin Biol ; 2(6): 463-7, 1995.
Artigo em Francês | MEDLINE | ID: mdl-8646342

RESUMO

The search for human Hb variants exhibiting a low oxygen affinity without requiring 2,3-diphosphoglycerate, together with a low oxygation rate, is of an increased interest in the view of producing an artificial oxygen carrier. We have synthesized the recombinant Hb beta 41Phe-->Tyr (rHb beta F41Y) which exhibits a low oxygen affinity due to the stabilization of the deoxy state of tetrameric Hb [1]. Interestingly, the autooxydation rate for this mutant is similar to that for Hb A. We have associated the mutation beta F41Y with the naturally occurring beta 82Lys-->Asp substitution (Hb Providence) known to be responsible for a low oxygen affinity [2]. The second-site mutation further decreases the oxygen affinity of the rHb beta F41Y. The effects of the beta F41Y and K82D mutations are additive, resulting in a four fold decrease in oxygen affinity of the artificial mutant Hb beta F41Y-K82D, compared to Hb A. In spite of the marked decrease in oxygen affinity, the autooxydation rate is 2- to 3 fold larger than that of Hb A. These data show that it is possible to adjust the oxygen binding properties of human Hb by using protein engineering methods. Because of the low oxygen affinity coexisting with a moderately increased autooxydation rate, this variant is a good candidate for the development of a Hb-based oxygen carrier.


Assuntos
Hemoglobinas/metabolismo , Oxigênio/sangue , Proteínas Recombinantes/metabolismo , Regulação Alostérica , Ácido Aspártico/química , Hemoglobinas/genética , Humanos , Cinética , Lisina/química , Mutação , Oxirredução , Fenilalanina/química , Proteínas Recombinantes/genética , Tirosina/química
18.
Parasite ; 7(3): 167-72, 2000 Sep.
Artigo em Francês | MEDLINE | ID: mdl-11031751

RESUMO

The present review underlines the knowledge of Cryptosporidium, especially its biodiversity and transmission. The presence of the parasite in different mammal host species is discussed with real, potential risk of transmission to humans. The potential role of insects in mechanical transmission of the parasite is evaluated by experimental protocols. The cost of cryptosporidiosis at health and economic levels are mentioned, which emphasises the importance of detection and identification of the parasite in the environment and in wild mammal species, using specific molecular tools. Potential measures to be accomplished in order to fight off cryptosporidiosis are also noted.


Assuntos
Animais Selvagens/parasitologia , Criptosporidiose/transmissão , Vetores de Doenças , Animais , Cryptosporidium , Ecossistema , Humanos , Insetos Vetores , Fatores de Risco
19.
Presse Med ; 26(12): 555-7, 1997 Apr 12.
Artigo em Francês | MEDLINE | ID: mdl-9161429

RESUMO

OBJECTIVES: We searched for signs of metabolic acidosis and associated hyperlactatemia in case of sodium valproate overdose. PATIENTS AND METHODS: A retrospective study was conducted in the toxicology intensive care unit at the Fernand Widal hospital from 1990 to 1995. Patients retained for study had sodium valproate levels above the therapeutic range (> 600 mumol/l). Data collected included past history, intubation for mechanical ventilation, administration of catecholamines and infusion of bicarbonate or sodium lactate, and blood pressure. Laboratory tests included serum sodium valproate, pH, PCO2, bicarbonate, anion balance and lactate. RESULTS: The study included 22 consecutive patients. None had a history of liver disease. Thirteen patients were intubated before admission to intensive care. Two received catecholamines. None of the patients received bicarbonate or sodium lactate. Mean blood pressure was 118 +/- 16 mmHg, mean serum sodium valproate was 2668 +/- 2437 mumol/l, mean pH was 7.41 +/- 0.08, mean PO2 35.6 +/- 8.0, mean anion imbalance 23.2 +/- 6.0 mmol/l and mean lactate 5.0 +/- 2.1 mmol/l. There was a significant correlation between lactase and pH (p < 0.003). CONCLUSION: We found metabolic acidosis with major anion imbalance and high lactate levels in patients with acute sodium valproate intoxication. Hyperlactatemia could be due to the direct effect of sodium valproate or to an unknown mechanism.


Assuntos
Acidose/etiologia , Lactatos/sangue , Ácido Valproico/intoxicação , Doença Aguda , Adulto , Feminino , Humanos , Unidades de Terapia Intensiva , Masculino , Estudos Retrospectivos
20.
Bull Acad Natl Med ; 182(1): 101-12; discussion 112-5, 1998.
Artigo em Francês | MEDLINE | ID: mdl-9622936

RESUMO

The diagnosis of Deep Venous Thrombosis (DVT) by duplex ultrasound is absolutely possible out of specialized centers. Low Molecular Weight Heparins (LMWH) allow to obtain a greater efficacy and safety compared to Unfractionated Heparin (UFH). The control of LMWH is very reduced. Two studies have just been published on the topic of treatment of DVT at home. The group of patients treated at home with LMWH is not presenting more complications than the group of patients initially treated at the hospital with UFH. Nevertheless, these studies concern a very selective population of patients. Our center has been proceeding to a study for 4 years (1993-1997) in comparing the treatment at home of proximal DVT by LMWH then oral anticoagulant, to the initial treatment (10 days) in hospital by also using LMWH then oral anticoagulant. The first results show that there is no difference between both groups in terms of end-points: death, extension or recurrence of the thrombus, pulmonary embolism, bleeding. Therefore, the treatment of some type of proximal DVT is possible at home. Nevertheless, it is necessary to be very cautions as the population studied so far is a selected one. Etiologies of DVT are a constant obsessive fear. DVT or pulmonary embolism represents a real general disease which is going to progress along life. The intervention of a specialized center is always necessary. It is a work in team which must get the upper hand compared to an isolated medical action.


Assuntos
Assistência Ambulatorial/métodos , Tromboflebite/tratamento farmacológico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticoagulantes/uso terapêutico , Feminino , França , Heparina de Baixo Peso Molecular/uso terapêutico , Humanos , Masculino , Pessoa de Meia-Idade , Tromboflebite/diagnóstico
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