RESUMEN
BACKGROUND: Allergy and allergic asthma are significant health burdens in developed countries and are increasing in prevalence. Dendritic cells (DCs) initiate immune responses to common aeroallergens, and ADAM10 has been demonstrated to be important for the development of adaptive responses. This study's objective was to understand the role of ADAM10 on DCs in the development of allergic and anaphylactic responses. METHODS: In this study, we used mouse models of allergic airway inflammation (house dust mice and Alternaria alternata) and OVA-induced models of active anaphylaxis to determine the DC-specific function of ADAM10 and Notch signaling. To examine TH 1 and TH 17 immunity infection with Anaplasma phagocytophilum and Citrobacter rodentium respectively, were used. RESULTS: Mice, which have ADAM10 deleted from DCs, have dramatic reductions in IgE production and do not develop significant TH 2 immune responses. Further, ADAM10DC-/- mice are resistant to IgE-mediated anaphylaxis. This response is selective for TH 2 immunity as TH 1 and TH 17 immunity is largely unaffected. Notch1, a known ADAM10 substrate, when knocked out of DCs (Notch1DC-/- ) demonstrated a similar reduction in anaphylaxis and IgE. Without ADAM10 and Notch1 signaling, DCs were unable to make cytokines that stimulate TH 2 cells and cytokines. Anaphylaxis and allergic lung inflammation were restored in ADAM10DC-/- with the overexpression of the Notch1-intracellular domain, confirming the role of Notch signaling. CONCLUSIONS: Targeting ADAM10 and Notch1 on DCs represent a novel strategy for modulating TH 2 immune responses and IgE production.
Asunto(s)
Proteína ADAM10/metabolismo , Secretasas de la Proteína Precursora del Amiloide/metabolismo , Células Dendríticas/inmunología , Células Dendríticas/metabolismo , Inmunoglobulina E/inmunología , Proteínas de la Membrana/metabolismo , Receptor Notch1/metabolismo , Proteína ADAM10/genética , Secretasas de la Proteína Precursora del Amiloide/genética , Anafilaxia/inmunología , Anafilaxia/metabolismo , Animales , Biomarcadores , Modelos Animales de Enfermedad , Expresión Génica , Hipersensibilidad/inmunología , Hipersensibilidad/metabolismo , Inmunoglobulina G/sangre , Inmunoglobulina G/inmunología , Interleucina-6/genética , Interleucina-6/metabolismo , Factor 4 Similar a Kruppel , Factores de Transcripción de Tipo Kruppel/genética , Factores de Transcripción de Tipo Kruppel/metabolismo , Proteínas de la Membrana/genética , Ratones , Ratones Noqueados , Pyroglyphidae/inmunología , Receptor Notch1/genética , Transducción de Señal , Células TH1/inmunología , Células TH1/metabolismo , Células Th17/inmunología , Células Th17/metabolismo , Células Th2/inmunología , Células Th2/metabolismoRESUMEN
CASE: An otherwise healthy 8-month-old boy presented with a pathologic fracture of the distal aspect of the radius. Further work-up demonstrated widespread osseous lesions of the axial and the appendicular skeleton with no soft-tissue or visceral involvement. CONCLUSION: Infantile myofibromatosis has a spectrum of severity that demands a careful and complete work-up. In rare cases such as the present one, it can manifest as multiple osseous lesions. The patient in the present case was managed conservatively, with no morbidity demonstrated at 1 year of follow-up.
RESUMEN
We report the novel HLA-Cw allele HLA-Cw*0751. The allele was identified during routine sequence-based typing in our laboratory. The novel allele is identical to Cw*07020101 except for a single nucleotide change in codon 90.2 in position 268. HLA-Cw*0751 allele possesses an adenine at position 268 in exon 2, while HLA-Cw*07020101 has a cytosine at this position. Although this substitution does not change serologic reactivity of HLA-Cw7 molecule, it changes the amino acid at codon 90 from an aspartic acid to an alanine. Aspartic acid is polar and acidic, while alanine is non-polar and neutral.
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Antígenos HLA-C/genética , Adenina/química , Alelos , Sustitución de Aminoácidos , Citosina/química , Antígenos HLA-C/química , HumanosRESUMEN
Centaurin beta4 proteins are products of the DDEF1 (development and differentiation-enhancing factor 1) locus on human chromosome 8q24.1-24.2. Recent reports have indicated that this region and its products are amplified during development of several human cancers. Centaurins are GAPs (GTPase-activating proteins) that, together with GEFs (guanine nucleotide-exchange factors), regulate cyclic activation of Arfs (ADP-ribosylation factors), members of the Ras GTPase superfamily. Centaurin beta4 proteins associate with a variety of cellular signalling components implicated in control of growth, survival and movement and may act to direct assembly and/or disassembly of molecular complexes in concert with Arf, lipid and protein phosphorylation signalling pathways.
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Proteínas Adaptadoras Transductoras de Señales/metabolismo , Neoplasias/metabolismo , Proteínas Adaptadoras Transductoras de Señales/genética , Empalme Alternativo , Animales , Humanos , Lípidos/química , Familia de Multigenes , Neoplasias/genética , Estructura Terciaria de Proteína , Transducción de Señal/fisiologíaRESUMEN
This study was undertaken to evaluate the efficacy and safety of olanzapine compared with fluphenazine in the treatment of patients who met the Diagnostic and Statistical Manual, fourth edition (DSM-IV) diagnostic criteria for schizophrenia or schizoaffective disorder. This was a long-term (22-week), randomized, double-blind, parallel clinical trial. Sixty patients (mean age, 35.4 years) were randomly assigned to either olanzapine (n=30) or fluphenazine (n=30). They received treatment at three centers in Croatia during a 22-week study period and were assessed weekly for the first 6 weeks and monthly thereafter. Efficacy was measured using the Brief Psychiatric Rating Scale (BPRS), the Positive and Negative Syndrome Rating Scale (PANSS) and the Clinical Global Impression (CGI) Severity and Improvement scores. The Hillside Akathisia Scale (HAS), Simpson-Angus Scale (SAS), Abnormal Involuntary Movement Scale (AIMS), vital signs, laboratory tests, and treatment-emergent adverse events were assessed to evaluate safety. The olanzapine group showed significantly greater mean decreases from baseline to endpoint for BPRS total (-25.8 vs. -16.5, P=.035), PANSS total (-45.7 vs. -29.5, P=.037), PANSS positive (-13.0 vs. -7.9, P=.034), and CGI Severity (-2.2 vs. -1.3, P=.031) scores. The olanzapine group showed greater mean decreases on all measures of extrapyramidal symptoms, significantly so for the SAS (-2.1 vs. 1.9, P=.004) and HAS (-3.4 vs. 2.6, P=.028). Patients in the fluphenazine group experienced a higher incidence of treatment-emergent adverse events (76.7% vs. 50.0%, P=.032). Weight gain was the most frequently reported adverse event in the olanzapine group (16.7% vs. 0.0%, P=.020). Akathisia (30.0% vs. 10.0%, P=.053) and insomnia (20.0% vs. 0.0%, P=.010) appeared most frequent in the fluphenazine group. Daily use of anticholinergics and benzodiazepines were both significantly greater for the fluphenazine group (P=.003 and.04, respectively). No significant changes were observed in vital signs, ECG, or clinical chemistry. The study indicates that olanzapine has advantages in both efficacy and safety compared to fluphenazine; however, the small sample size limits our ability to draw definitive conclusions.
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Antipsicóticos/uso terapéutico , Benzodiazepinas/uso terapéutico , Flufenazina/uso terapéutico , Esquizofrenia/tratamiento farmacológico , Adolescente , Adulto , Anciano , Análisis de Varianza , Método Doble Ciego , Femenino , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Olanzapina , Escalas de Valoración Psiquiátrica/estadística & datos numéricos , Resultado del TratamientoRESUMEN
Clozapine has been the gold standard for treatment of patients with refractory schizophrenia but is associated with serious safety liabilities. This has prompted the search for therapeutic alternatives for treatment-resistant schizophrenia. The objective of this study was to compare the efficacy and safety of olanzapine versus clozapine in schizophrenic patients who failed to respond adequately to antipsychotic medication or who experienced intolerable adverse effects associated with the medication. This 18-week, randomized, double-blind, parallel study compared treatment with either olanzapine (5-25 mg/day, n=75) or clozapine (100-500 mg/day, n=72) in patients with schizophrenia who were nonresponsive to, or intolerant of, standard acceptable antipsychotic therapy. At the 18-week endpoint, no statistically significant differences were found between olanzapine and clozapine in any efficacy measure used: Positive and Negative Syndrome Scale (PANSS) total, positive, negative, or general psychopathology or Clinical Global Impression severity (CGI-S). Response rates based on the criteria of Kane et al. [Arch. Gen. Psychiatry 45 (1988) 789] were also not significantly different between olanzapine-treated (57.9%) and clozapine-treated patients (60.8%). There were no significant differences in measurements of extrapyramidal symptoms or electrocardiography, and no clinically and statistically significant changes were seen in vital signs or laboratory measures in either group. Both treatments were well tolerated. Olanzapine demonstrated similar efficacy to clozapine in patients who had failed previous treatment because of lack of efficacy (treatment resistance) or intolerable side effects (treatment intolerance). Olanzapine therefore presents a safe alternative in the treatment of refractory schizophrenia.
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Antipsicóticos/uso terapéutico , Clozapina/uso terapéutico , Pirenzepina/análogos & derivados , Pirenzepina/uso terapéutico , Esquizofrenia/tratamiento farmacológico , Adolescente , Adulto , Anciano , Antipsicóticos/efectos adversos , Enfermedades de los Ganglios Basales/etiología , Benzodiazepinas , Peso Corporal/efectos de los fármacos , Clozapina/efectos adversos , Método Doble Ciego , Resistencia a Medicamentos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Olanzapina , Pirenzepina/efectos adversos , Escalas de Valoración PsiquiátricaRESUMEN
Since its inception, continuous renal replacement therapy (CRRT) has been performed in critical care units with or without the involvement of nephrology nursing support (1,2). It is apparent that the issue of providing care to patients requiring this therapy is not so much a debate on the nursing control of CRRT, but a focused discussion on the nursing management and delivery of care to the patient receiving CRRT in the intensive care setting. Although the choice of a nursing care model for CRRT is dependent on many clinical and organisational factors, the use of one nursing specialty to deliver CRRT care can leave gaps in practice. The Joint or Collaborative Nephrology/critical care nursing model brings the highest level of nursing expertise to the bedside. The joint model tends to promote collaboration between two distinct nursing specialties, with opportunities for setting joint standards and promoting research. With this in mind, this discussion will examine some of the factors affecting structuring of nursing care, describe nursing models currently in use, compare the attributes of each, and conclude which model is preferred for the delivery of nursing care for CRRT.
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Cuidados Críticos/organización & administración , Modelos de Enfermería , Rol de la Enfermera , Terapia de Reemplazo Renal/enfermería , Competencia Clínica/normas , Conducta Cooperativa , Humanos , Relaciones Interprofesionales , Nefrología , Grupo de Atención al Paciente/organización & administración , Autonomía Profesional , Especialidades de Enfermería/organización & administraciónRESUMEN
The advent of high-throughput methods for the analysis of global gene expression, together with the Malaria Genome Project open up new opportunities for furthering our understanding of the fundamental biology and virulence of the malaria parasite. Serial analysis of gene expression (SAGE) is particularly well suited for malarial systems, as the genomes of Plasmodium species remain to be fully annotated. By simultaneously and quantitatively analyzing mRNA transcript profiles from a given cell population, SAGE allows for the discovery of new genes. In this study, one reports the successful application of SAGE in Plasmodium falciparum, 3D7 strain parasites, from which a preliminary library of 6880 tags corresponding to 4146 different genes was generated. It was demonstrated that P. falciparum is amenable to this technique, despite the remarkably high A-T content of its genome. SAGE tags as short as 10 nucleotides were sufficient to uniquely identify parasite transcripts from both nuclear and mitochondrial genomes. Moreover, the skewed A-T content of parasite sequence did not preclude the use of enzymes that are crucial for generating representative SAGE libraries. Finally, a few modifications to DNA extraction and cloning steps of the SAGE protocol proved useful for circumventing specific problems presented by A-T rich genomes.
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Expresión Génica/genética , Genoma de Protozoos , Plasmodium falciparum/genética , Animales , Núcleo Celular/genética , ADN Complementario/genética , ADN Protozoario/genética , Etiquetas de Secuencia Expresada , Técnicas Genéticas , Biblioteca Genómica , Mitocondrias/genética , ARN Mensajero/genética , Análisis de SecuenciaRESUMEN
Plasmodium falciparum is a protozoan parasite responsible for the most severe forms of human malaria. All the clinical symptoms and pathological changes seen during human infection are caused by the asexual blood stages of Plasmodium. Within host red blood cells, the parasite undergoes enormous developmental changes during its maturation. In order to analyse the expression of genes during intraerythrocytic development, DNA microarrays were constructed and probed with stage-specific cDNA. Developmental upregulation of specific mRNAs was found to cluster into functional groups and revealed a co-ordinated programme of gene expression. Those involved in protein synthesis (ribosomal proteins, translation factors) peaked early in development, followed by those involved in metabolism, most dramatically glycolysis genes. Adhesion/invasion genes were turned on later in the maturation process. At the end of intraerythrocytic development (late schizogony), there was a general shut-off of gene expression, although a small set of genes, including a number of protein kinases, were turned on at this stage. Nearly all genes showed some regulation over the course of development. A handful of genes remained constant and should be useful for normalizing mRNA levels between stages. These data will facilitate functional analysis of the P. falciparum genome and will help to identify genes with a critical role in parasite progression and multiplication in the human host.
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Eritrocitos/parasitología , Perfilación de la Expresión Génica , Análisis de Secuencia por Matrices de Oligonucleótidos/métodos , Plasmodium falciparum/genética , Animales , Moléculas de Adhesión Celular/genética , Análisis por Conglomerados , Citoesqueleto/genética , Glucólisis/genética , Humanos , Plasmodium falciparum/patogenicidad , Biosíntesis de Proteínas/genéticaRESUMEN
The advent of high-density gene array technology has revolutionized approaches to drug design, development, and characterization. At the laboratory level, the efficient, consistent, and dependable exploitation of this complex technology requires the stringent standardization of protocols and data analysis platforms. The Affymetrix YE6100 expression GeneChip platform was evaluated for its performance in the analysis of both global (6,000 yeast genes) and targeted (three pleiotropic multidrug resistance genes of the ATP binding cassette transporter family) gene expression in a heterologous yeast model system in the presence and absence of the antimalarial drug chloroquine. Critical to the generation of consistent data from this platform are issues involving the preparation of the specimen, use of appropriate controls, accurate assessment of experiment variance, strict adherence to optimized enzymatic and hybridization protocols, and use of sophisticated bioinformatics tools for data analysis.
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Antimaláricos/farmacología , Cloroquina/farmacología , Farmacorresistencia Microbiana/genética , Análisis de Secuencia por Matrices de Oligonucleótidos/instrumentación , Saccharomyces cerevisiae/genética , Transportadoras de Casetes de Unión a ATP/genética , Algoritmos , Resistencia a Múltiples Medicamentos/genética , Análisis de Secuencia por Matrices de Oligonucleótidos/métodos , ARN Mensajero/genética , Saccharomyces cerevisiae/efectos de los fármacosRESUMEN
Organ transplantation has become an accepted treatment method for a multitude of conditions once deemed untreatable. Increasing numbers of patients are treated by nurse practitioners before and after transplantation in a variety of settings, such as primary and specialty care clinics, urgent care, critical care units, and long-term care facilities. This article outlines the role of the acute care nurse practitioner in the management of adult transplant recipients in a variety of health care settings and reviews the problems and interventions specific to this patient group. Emphasis is placed on the referral process and collaboration with the transplantation team in patient management.
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Enfermedad Aguda/enfermería , Continuidad de la Atención al Paciente/organización & administración , Perfil Laboral , Enfermeras Practicantes/organización & administración , Trasplante de Órganos/enfermería , Adulto , Conducta Cooperativa , Humanos , Servicios de Información , Internet , Grupo de Atención al Paciente/organización & administración , Derivación y ConsultaRESUMEN
Rapid changes in health care toward cost-effective managed care have resulted in the evolution of the transplant advanced practice nurse to address the care needs of a specific patient population. This article describes the evolution of this role at one institution. The specific responsibilities of the transplant advanced practice nurse are delineated, and phases of development for the experienced clinical nurse specialist entering the role as a novice nurse practitioner are identified and discussed.
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Perfil Laboral , Enfermeras Clínicas/organización & administración , Enfermeras Practicantes/organización & administración , Trasplante/enfermería , Análisis Costo-Beneficio , Cuidados Críticos , Humanos , Programas Controlados de Atención en Salud , Evaluación de Necesidades , Enfermeras Clínicas/educación , Enfermeras Clínicas/psicología , Enfermeras Practicantes/educación , Enfermeras Practicantes/psicología , Desarrollo de ProgramaAsunto(s)
Plasmodium falciparum/enzimología , Telomerasa/antagonistas & inhibidores , Animales , Diseño de Fármacos , Resistencia a Medicamentos , Inhibidores Enzimáticos/farmacología , Eritrocitos/parasitología , Humanos , Hibridación de Ácido Nucleico , Nucleósidos/farmacología , Nucleótidos/farmacología , Plasmodium falciparum/efectos de los fármacos , Plasmodium falciparum/crecimiento & desarrollo , Reacción en Cadena de la Polimerasa/métodos , Secuencias Repetitivas de Ácidos Nucleicos , Sensibilidad y Especificidad , Telomerasa/metabolismoRESUMEN
A guanidinium isothiocyanate (GITC) lysis solution was evaluated for its efficacy in preserving nucleic acids for subsequent analysis after prolonged storage at room temperature. Aliquots of thyroid crude cell lysates were stored at 22 degrees C for 8 weeks in the GITC solution. Crude cell lysates stored for 2 weeks in the GITC solution consistently provided adequate RNA and DNA for reverse transcriptase-polymerase chain reaction (RT-PCR) and PCR, respectively, of beta 2-microglobulin, thyroid stimulating hormone receptor (TSHR), and thyroglobulin. Interestingly, the thyroglobulin and TSHR messages from thyroid fine needle aspirate samples were detected by RT-PCR only when stored at room temperature for less than 1 week, whereas the RT-PCR product for beta 2-microglobulin was detectable in 95% of the samples at 3 months. In addition, thyroglobulin DNA was amplified by PCR in nearly all samples stored at 22 degrees C for 2 months. These data suggest that GITC solutions can be used to preserve nucleic acids in most circumstance until transported to laboratories equipped and staffed with appropriate resources.
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ADN/química , Preservación Biológica/métodos , ARN Mensajero/química , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Biopsia con Aguja , Tampones (Química) , Fraccionamiento Celular/métodos , ADN/aislamiento & purificación , Guanidinas , Humanos , Isotiocianatos , ARN Mensajero/aislamiento & purificación , Receptores de Tirotropina/genética , Soluciones , Espectrofotometría , Temperatura , Tiroglobulina/genética , Glándula Tiroides/química , Glándula Tiroides/patología , Microglobulina beta-2/genéticaRESUMEN
Continuous renal replacement therapy (CRRT) is performed in critical care units around the world with various levels of involvement from critical care and nephrology nurses. In this article, factors affecting the delivery of nursing care and the particular expertise nephrology and critical care nurses have in the area of CRRT are examined. Based on this discussion, three proposed models of nursing care for the patient receiving CRRT are discussed: the Nephrology Nursing Model, the Critical Care Model, and the Collaborative Model. Based on related research findings and a comparison of the models, the Collaborative Model is the preferred one, as it brings the highest level of expertise directly to the patient. For the Collaborative Model to work, a framework for collaboration and a high degree of commitment from both specialties must be maintained.
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Unidades de Cuidados Intensivos/organización & administración , Personal de Enfermería en Hospital , Personal de Enfermería en Hospital/organización & administración , Terapia de Reemplazo Renal/métodos , Humanos , Modelos Organizacionales , Personal de Enfermería en Hospital/normas , Manejo de Atención al Paciente , Estados UnidosRESUMEN
OBJECTIVES: The purpose of this investigation was to determine the feasibility of using the polymerase chain reaction to detect bacteria in amniotic fluid and to compare pregnancy outcomes in subsets of women categorized by amniotic fluid culture, polymerase chain reaction, and interleukin-6 findings. STUDY DESIGN: Amniotic fluid from 54 pregnancies with preterm labor and no clinical evidence of intraamniotic infection was evaluated with use of the polymerase chain reaction, interleukin-6, and bacterial culture. Gestational age, newborn weight, and time between amniocentesis and delivery were compared between subsets of women categorized by these tests. RESULTS: With use of the polymerase chain reaction <100 bacteria per milliliter could be detected in amniotic fluid. A total of 55.5% of the amniotic fluid samples were polymerase chain reaction positive, whereas 9.2% of culture results were positive. Birth weights and gestational age at delivery were less and time from amniocentesis to delivery was shorter in the polymerase chain reaction-positive group (p < 0.05). Nine samples (15%) had elevated interleukin-6 concentrations; of these, six were polymerase chain reaction positive. CONCLUSIONS: The polymerase chain reaction is a sensitive means of detecting bacteria in amniotic fluid. These results provide further evidence of an association between preterm delivery and intraamniotic infection. Not all amniotic fluid samples with elevated interleukin-6 levels have bacteria detectable by the polymerase chain reaction. We anticipate that the polymerase chain reaction will provide another avenue for the detection of bacteria in amniotic fluid.
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Líquido Amniótico/microbiología , Bacterias/aislamiento & purificación , Trabajo de Parto Prematuro/microbiología , Reacción en Cadena de la Polimerasa , Adulto , Amniocentesis , Líquido Amniótico/química , Peso al Nacer , Parto Obstétrico , Estudios de Factibilidad , Femenino , Edad Gestacional , Humanos , Recién Nacido , Interleucina-6/análisis , Embarazo , Resultado del Embarazo , Sensibilidad y Especificidad , Factores de TiempoRESUMEN
Archival pathological specimens are a source of RNA and DNA for clinical surveillance or retrospective studies. We employed a modification of the acid guanidium thiocyanate-phenol-chloroform extraction method for the recovery of total RNA from formalin-fixed, paraffin-embedded neoplastic thyroid tissue. The extracted RNA was used for reverse transcription of ptc and subsequent amplification of the complementary DNA (cDNA) by the reverse transcription-polymerase chain reaction (RT-PCR). In lieu of 32P-labeled DNA for hybridization studies, we supplemented the nucleotide pool in the amplification reaction with a modified pyrimidine, digoxigenin-11-dUTP. Digoxigenin-11-dUTP was incorporated directly into the PCR product, eliminating the need for hybridization, posthybridization washes, and prolonged autoradiography. These products were resolved by electrophoresis on agarose gels, Southern blotted to nylon membranes, and rapidly detected by chemiluminescence. This nonradioisotopic method has expedited and reduced the cost for molecular investigations with archival pathological specimens by providing equal sensitivity to or greater sensitivity than that of DNA-labeled radionuclides without the associated biological hazards.
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Carcinoma Papilar/genética , Reacción en Cadena de la Polimerasa/métodos , Proto-Oncogenes/genética , Neoplasias de la Tiroides/genética , Cartilla de ADN , Nucleótidos de Desoxiuracil/química , Digoxigenina/análogos & derivados , Digoxigenina/química , Electroforesis en Gel de Agar/métodos , Formaldehído , Humanos , Indicadores y Reactivos , Hibridación de Ácido Nucleico , Adhesión en Parafina , Radioisótopos de Fósforo , ARN/aislamiento & purificación , ADN Polimerasa Dirigida por ARN , Glándula Tiroides/patología , Fijación del Tejido , Microglobulina beta-2RESUMEN
Drug resistance in Plasmodium falciparum is an expanding problem in most endemic areas. Recent studies have suggested the potential involvement of genes in the MDR gene family in resistance to quinoline-containing compounds in P. falciparum. In this study a molecular analysis of pfmdr 1 in recent isolates from Thailand was done (1) to further examine the role of pfmdr 1 in drug-resistant isolates and (2) to examine the reported association of pfmdr 1 intragenic alleles and chloroquine resistance. Most of the isolates (10 of 11) were resistant to all compounds tested. Analysis of pfmdr 1 revealed an apparent association between increased gene copy number and increased level of expression of pfmdr 1 and decreased susceptibility to mefloquine and halofantrine. Sequence analysis of pfmdr 1 in these isolates revealed no association of intragenic alleles with chloroquine resistance.
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Resistencia a Medicamentos/genética , Genes Protozoarios , Plasmodium falciparum/efectos de los fármacos , Plasmodium falciparum/genética , Animales , Antimaláricos/farmacología , Secuencia de Bases , ADN Protozoario/genética , Amplificación de Genes , Humanos , Malaria Falciparum/tratamiento farmacológico , Mefloquina/farmacología , Datos de Secuencia Molecular , Fenantrenos/farmacología , Plasmodium falciparum/aislamiento & purificación , ARN Mensajero/genética , ARN Protozoario/genética , TailandiaRESUMEN
The emergence of chloroquine resistance in Plasmodium falciparum has necessitated the development of alternate strategies for chemotherapy and chemoprophylaxis. One approach has been the identification of drugs that do not possess any intrinsic antimalarial activity when used alone but that potentiate the effect of currently available antimalarial drugs, such as chloroquine. We identified fluoxetine hydrochloride (Prozac), a commonly prescribed antidepressant, as another resistance modulator for drug-resistant P. falciparum. Studies with chloroquine-resistant clones and isolates from various geographical locations confirmed our initial observations with a chloroquine-resistant P. falciparum clone, W2. Fluoxetine concentrations of 500 nM were found to effectively modulate chloroquine resistance by 66% in clone W2. In comparison, verapamil at similar concentrations was observed to modulate chloroquine resistance in clone W2 by 61%. Neither fluoxetine nor verapamil was observed to possess any innate antimalarial activity. These data augment the current description of the chloroquine resistance phenotype and may provide additional insights into lead-directed synthesis of new antimalarial drugs.
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Cloroquina/farmacología , Fluoxetina/farmacología , Plasmodium falciparum/efectos de los fármacos , Animales , Farmacorresistencia Microbiana , Sinergismo Farmacológico , Pruebas de Sensibilidad Microbiana , Fenotipo , Plasmodium falciparum/aislamiento & purificación , Verapamilo/farmacologíaRESUMEN
The rapid dissemination of chloroquine-resistant Plasmodium falciparum in West Africa has been well documented and represents a significant health threat to autochthonous populations. The methodical development of alternative chemotherapeutic agents demands that dispensing new antimalarial drugs (mefloquine, halofantrine, and artemisinine [qinghaosu]) be closely monitored in order to protect their clinical utility. Indeed, mefloquine-resistant strains of P. falciparum have been reported. We present data from experiments in vitro on the innate resistance of P. falciparum isolates to mefloquine as well as a disturbing observation of transient resistance to artemisinine. The implications for the extended efficacy of these new antimalarial drugs are addressed.