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1.
Metrologia ; 53(5)2016.
Artigo em Inglês | MEDLINE | ID: mdl-32165768

RESUMO

Using a watt balance and a frequency comb, a mass-energy equivalence is derived. The watt balance compares mechanical power measured in terms of the meter, the second, and the kilogram to electrical power measured in terms of the volt and the ohm. A direct link between mechanical action and the Planck constant is established by the practical realization of the electrical units derived from the Josephson and the quantum Hall effects. By using frequency combs to measure velocities and acceleration of gravity, the unit of mass can be realized from a set of three defining constants: the Planck constant h, the speed of light c, and the hyperfine splitting frequency of 133Cs.

2.
Clin Exp Allergy ; 42(2): 284-92, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22181034

RESUMO

BACKGROUND: Although adrenaline is recommended as first line treatment for anaphylaxis, it is often not utilized. There has been a debate about when adrenaline autoinjectors should be prescribed and how many should be dispensed. OBJECTIVES: To see how many adrenaline autoinjectors were used during anaphylactic reactions and to determine why they were not used in situations where they were clinically indicated. METHODS: Patients were recruited prospectively at 14 paediatric allergy clinics throughout UK. Participants completed a questionnaire covering demographic data, atopic status and details of allergic reactions in the previous year and reasons for using more than one device. RESULTS: A total of 969 patients were recruited of whom 466 (48.1%, 95% CI: 37.9-58.2) had had at least one reaction in the previous year; 245 (25.3%, 95% CI: 16.2-34.4) of these reactions were anaphylaxis. An adrenaline autoinjector was used by 41 (16.7%, 95% CI: 11.7-21.3) participants experiencing anaphylaxis. Thirteen participants received more than one dose of adrenaline, for nine of these a health professional gave at least one. The commonest reasons for using more than one were severe breathing difficulties (40%), lack of improvement with first dose (20%) and miss-firing (13.3%). The commonest reasons for not using adrenaline in anaphylaxis were 'thought adrenaline unnecessary' (54.4%) and 'unsure adrenaline necessary' (19.1%). Many with wheeze did not use their autoinjector. CONCLUSIONS AND CLINICAL RELEVANCE: Adrenaline is used by only a minority of patients experiencing anaphylaxis in the community. Thirteen of the 41 patients with anaphylaxis who used their autoinjector needed another dose of adrenaline. Further research is needed to consider how to best encourage the usage of adrenaline when clinically indicated in anaphylaxis.


Assuntos
Agonistas alfa-Adrenérgicos/administração & dosagem , Anafilaxia/prevenção & controle , Epinefrina/administração & dosagem , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Injeções Subcutâneas/instrumentação , Injeções Subcutâneas/métodos , Masculino , Estudos Prospectivos , Reino Unido
3.
Orthopade ; 41(5): 346-53, 2012 May.
Artigo em Alemão | MEDLINE | ID: mdl-22552541

RESUMO

Muscle trauma in minimally invasive hip arthroplasty using a direct anterior approach was assessed by magnetic resonance imaging (MRI) in 25 patients preoperatively, as well as 6 months after total hip replacement. The MRI evaluation included the measurement of changes in muscle cross-sectional area (CSA = atrophy) and fatty infiltration of the muscles. Using MRI, preoperatively existing and operatively caused muscle tissue damage could be detected by assessing changes in muscle CSA and fatty infiltration. Even preoperatively, a muscular atrophy and fatty infiltration could be demonstrated in the diseased hip. Using the minimally invasive direct anterior approach, a postoperative significantly reduced CSA and significantly increased fatty degeneration was detected for the M. tensor fasciae latae and the M. glutaeus minimus. No increased damage of the M. glutaeus medius could be detected.


Assuntos
Artroplastia de Quadril/efeitos adversos , Imageamento por Ressonância Magnética/métodos , Procedimentos Cirúrgicos Minimamente Invasivos/efeitos adversos , Músculo Esquelético/lesões , Músculo Esquelético/patologia , Osteoartrite do Quadril/patologia , Osteoartrite do Quadril/cirurgia , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
4.
J Viral Hepat ; 18(1): 70-6, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20196807

RESUMO

Asian Americans represent an important cohort at high risk for viral hepatitis. To determine the prevalence of Hepatitis B virus (HBV) and Hepatitis C virus (HCV) infection and HBV vaccination in a Vietnamese community, a total of 322 Vietnamese subjects from a local doctor's office and annual Vietnamese Health Fair were included in this study. Demographic and clinical data were collected. 2.2% of the screened cohort tested positive for anti-HCV and 9.3% tested positive for HBsAg. Unlike HBV-positive subjects, HCV-positive subjects had significantly higher liver enzymes (P = 0.0045 and P = 0.0332, respectively). The HBV-positive group was more likely to report jaundice (P = 0.0138) and a family history of HBV (P = 0.0115) compared to HBV-negative subjects. Forty-eight patients (15.5%) reported a family history of liver disease (HBV, HCV, HCC, cirrhosis, other). Of this 48, 68.8% reported no personal history of HBV vaccination and 77.1% reported no family history of vaccination for HBV. Among the 183 subjects without a family history of liver disease, 156 (85.2%) reported no personal history of vaccination and 168 (91.8%) reported no family history of vaccination. HBV vaccination rates in those reporting a family history of liver disease were significantly higher (P =0.020). There was a high prevalence of HBV infection in this community screening. Nevertheless, the rate for HBV vaccination was low. The low prevalence of abnormal liver enzymes in HBV-positive subjects emphasizes the need for screening to be triggered by risk factors and not by abnormal liver enzymes.


Assuntos
Serviços de Saúde Comunitária/métodos , Hepacivirus/imunologia , Vírus da Hepatite B/imunologia , Hepatite B/diagnóstico , Hepatite C/diagnóstico , Adulto , Emigrantes e Imigrantes , Hepatite B/epidemiologia , Antígenos de Superfície da Hepatite B/sangue , Vírus da Hepatite B/isolamento & purificação , Hepatite C/epidemiologia , Anticorpos Anti-Hepatite C/sangue , Humanos , Programas de Rastreamento , Pessoa de Meia-Idade , Prevalência , Vietnã/etnologia , Virginia/epidemiologia
5.
Drugs Future ; 35(3): 183-195, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-22287818

RESUMO

Viruses have long been considered potential anticancer treatments. Wild-type viruses have been tested as anticancer agents in clinical trials since the 1960s. The possibility of viral oncolysis as an alternate cancer therapy was transformed by the emergence of modern genetic engineering. The herpes simplex virus (HSV) family offers particular advantages for use as a viral oncolytic. The engineered vectors that make up oncolytic HSVs (oHSVs) have demonstrated remarkable safety in clinical trials, with some evidence of efficacy. The past decade has seen a focus on increasing the efficacy of oncolytic vectors by adding exogenous transgenes to enhance tumor destruction. The current paper describes the various strategies for engineering HSV for increased cancer tissue specificity and efficacy. Presented are the rationale, preclinical data and clinical data where available. This is meant to illustrate a basic framework for the development of a novel therapy meant to exploit the viral life cycle for the killing of cancer.

6.
Cancer Immunol Immunother ; 58(9): 1355-62, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19266198

RESUMO

The concept of using replicating oncolytic viruses in cancer therapy dates to the beginning of the twentieth century. However, in the last few years, an increasing number of pre-clinical and clinical trials have been carried out with promising preliminarily results. Novel, indeed, is the suggestion that viral oncolytic therapy might not operate exclusively through an oncolysis-mediated process but additionally requires the "assistance" of the host's immune system. Originally, the host's immune response was believed to play a predominant obstructive role against viral replication, hence limiting the anti-tumor efficacy of viral vectors. Recent data, however, suggest that the immune response may also play a key role in promoting tumor destruction in association with the oncolytic process. In fact, immune effector pathways activated during oncolytic virus-induced tumor rejection seem to follow a similar pattern to those observed when the broader phenomenon of immune-mediated tissue-specific rejection occurs in other immune-related pathologies. We recently formulated the "Immunologic Constant of Rejection" hypothesis, emphasizing commonalties in transcriptional patterns observed when tissue-destruction occurs: whether with a favorable outcome, such as in tumor rejection and pathogen clearance; or a destructive one, such as in allograft rejection or autoimmunity. Here, we propose that a similar mechanism induces clearance of virally infected tumors and that such a mechanism is primarily dependent on innate immune functions.


Assuntos
Efeito Citopatogênico Viral/imunologia , Terapia Genética , Neoplasias/imunologia , Neoplasias/terapia , Terapia Viral Oncolítica , Poxviridae/genética , Efeito Citopatogênico Viral/genética , Humanos , Neoplasias/genética
7.
Morphologie ; 93(300): 9-12, 2009 Mar.
Artigo em Francês | MEDLINE | ID: mdl-19394885

RESUMO

UNLABELLED: The infrahyoid flap is used in head and neck reconstruction, especially in oral defect. This study is designed to determine vascular pedicles and innervation of the infrahyoid muscles and flap. MATERIALS AND METHOD: The neck regions of 12 injected cadavers were investigated bilaterally. RESULTS: The arterial pedicles of the infrahyoid muscles are the superior and inferior thyroid arteries. The arterial pedicles of the flap are the superior thyroid artery. The venous pedicles of the muscles and flap are the superior thyroid, lingual and facial veins. The infrahyoid flap is innervated by the ansa cervicalis. CONCLUSION: The infrahyoid flap seems to be an excellent flap for oral, oropharynx and superior facial part reconstruction. It can be harvested easily in the same operation area.


Assuntos
Músculos do Pescoço/irrigação sanguínea , Músculos do Pescoço/inervação , Retalhos Cirúrgicos/irrigação sanguínea , Retalhos Cirúrgicos/inervação , Cadáver , Humanos , Procedimentos de Cirurgia Plástica/métodos
8.
Trop Biomed ; 35(2): 383-391, 2018 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33601812

RESUMO

Borago officinalis L. (Boraginaceae) is a plant of the Boraginaceae family, used in Algeria for food and medicinal purposes. This study reports the effect of flavonoids extracted from the aerial part of Borago officinalis L. (Boraginaceae) on the larvae and engorged adult females of the brown dog tick Rhipicephalus sanguineus (Latreille, 1806) using adults immersion test (AIT) and larval immersion test (LIT). For this purpose, the larvae and engorged female of Rhipicephalus sanguineus (Latreille, 1806) were exposed to serial dilutions of flavonoids extract (50 mg/ml, 25 mg/ml, 12.5 mg/ml and 6.25 mg/ml) using "dipping method" in vitro. The plant extract was obtained by fractionation using appropriate solvents. The extraction yield is 22% with a flavonoids concentration equal to 129.12 µg equivalent of quercetin/ml of the extract. The chromatographic analysis by high performance thin layer chromatography (HPTLC) reveals the presence of gallic acid, vanillic acid, kaempferol, dihydroxybenzoic and quercetin. The results obtained show that the flavonoids extract of Borago officunalis L. (Boraginaceae) considerably reduces the oviposition and the hatching rate of the eggs of Rhipicephalus sanguineus (Latreille, 1806) and was shown to be toxic against newly hatched larvae of Rhipicephalus sanguineus (Latreille, 1806) (P < 0.05).

9.
Odontol. sanmarquina (Impr.) ; 24(3): 269-276, jul.-sept. 2021.
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1255460

RESUMO

El síndrome X frágil (SXF) es un trastorno ligado al cromosoma X, en el brazo largo Xq27.3, que provoca diversas alteraciones como problemas de conducta, deficiencia intelectual, macroorquidia, pabellones auditivos grandes y prominentes, paladar profundo y ojival, prognatismo mandibular, maloclusión y anomalías dentarias. El objetivo de este informe fue presentar el caso clínico de una paciente de 16 años con SXF, leucodermia, que se sometió a un tratamiento ortopédico funcional de los maxilares para la corrección del apiñamiento dentario. En el examen clínico se observaron timidez, ansiedad, inestabilidad emocional, trastornos conductuales esporádicos asociados a discapacidad intelectual leve, alteraciones craneofaciales y oclusales. Luego del estudio, evaluación radiográfica panorámica y trazados cefalométricos, se decidió instalar un dispositivo ortopédico funcional de maxilar, tipo Pistas Planas Indirectas, para posterior tratamiento ortodóncico correctivo. Bien al inicio del tratamiento se observó dificultad de comprensión y colaboración por parte de la paciente y su responsable (madre) y, luego de 5 meses, aún con mejoras en las funciones estomatognáticas, se inició el tratamiento ortodóntico con dispositivo fijo, el que fue concluido luego de dos años. El éxito del tratamiento de ortopedia funcional de los maxilares y/u ortodóntico, principalmente en el SXF, se basa en el abordaje comportamental y motivación en todas las etapas del tratamiento por el profesional, así como en un ambiente familiar colaborativo.


The Fragile-X Syndrome (FXS) is a disorder linked to X chromosome, on the long arm Xq27.3, causing several changes such as behavioral problems, intellectual disability, macroorchidism, large and prominent auricles, deep and ogival palate, mandibular prognathism, increased mandibular angle, malocclusion, and dental anomalies. The objective was to present a case of a 16-year-old patient with FXS, leukoderma, submitted to orthopedic functional maxillary treatment to correct dental crowding. In general, clinical examination, behavioral changes such as shyness, anxiety, emotional lability, sporadic disturbances of behavior associated with mild mental disabilities were remarkable. After panoramic radiographic evaluation and cephalometric tracings, it was decided to install the functional orthopedic appliance of the jaws, Indirect Flat Planes type, for later corrective orthodontic treatment. At beginning of treatment, there was a difficulty in understanding and collaborating, not only from the patient's side but also from the mother's. After five months, even with the improvement in stomatognathic functions, orthodontic treatment with a fixed appliance was started, which was concluded after two years. Success of functional and / or orthodontic jaw orthopedics treatment, especially in FXS, is based on behavioral approach and motivation in all stages, by the professional as well as a collaborative family environment.

10.
Rev Sci Instrum ; 87(6): 061301, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27370418

RESUMO

A precise instrument, called a watt balance, compares mechanical power measured in terms of the meter, the second, and the kilogram to electrical power measured in terms of the volt and the ohm. A direct link between mechanical action and the Planck constant is established by the practical realization of the electrical units derived from the Josephson and the quantum Hall effects. We describe in this paper the fourth-generation watt balance at the National Institute of Standards and Technology (NIST), and report our initial determination of the Planck constant obtained from data taken in late 2015 and the beginning of 2016. A comprehensive analysis of the data and the associated uncertainties led to the SI value of the Planck constant, h = 6.626 069 83(22) × 10(-34) J s. The relative standard uncertainty associated with this result is 34 × 10(-9).

11.
Mol Immunol ; 34(5): 379-89, 1997 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9293771

RESUMO

Genetic restriction of immune responses to malaria antigens is an important issue for a better comprehension of malaria immunity as well as for development of subunit vaccines. To experimentally define the major histocompatibility complex restriction of immune responses to the highly repetitive Plasmodium falciparum high-molecular-weight antigen Pf332, H-2-congenic mice were immunized with EB200, a recombinant fragment of Pf332 consisting of degenerate repeat motifs. Strong B- and T-cell responses were elicited in H-2d and H-2k mice whereas responses in H-2b, H-2q and H-2s mice were of lower magnitude. The T-cell specificity elicited by EB200 was defined by in vitro proliferative responses to a panel of overlapping peptides spanning EB200. Dominant epitopes were identified for H-2d and H-2k mice, respectively, and an additional epitope was recognized by all five mouse strains. Selected EB200-derived peptides were further investigated for their ability to elicit T-cell help when injected as multiple antigen peptides. Defined H-2d- and H-2k-restricted T-cell epitopes generated high antibody levels in the respective mouse strains, as did several peptides lacking defined epitopes indicating the presence of additional H-2d- and H-2k-restricted, cryptic or subdominant T-cell epitopes in EB200. The biased H-2 restriction pattern of T-cell epitopes in Pf332 and, as previously reported, in structurally related repeats in the malaria antigens Pf11.1 and Pf155/RESA may be explained by a shared motif for H-2d and H-2k class II-restricted T-cell epitopes, as revealed by alignment of these sequences.


Assuntos
Antígenos de Protozoários/química , Epitopos de Linfócito T/química , Antígenos H-2/imunologia , Plasmodium falciparum/imunologia , Proteínas de Protozoários/química , Sequência de Aminoácidos , Animais , Anticorpos Antiprotozoários/biossíntese , Especificidade de Anticorpos , Antígenos de Protozoários/genética , Antígenos de Protozoários/imunologia , Epitopos de Linfócito T/genética , Epitopos de Linfócito T/imunologia , Antígenos H-2/química , Antígenos H-2/genética , Ativação Linfocitária , Malária/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Dados de Sequência Molecular , Fragmentos de Peptídeos/imunologia , Proteínas de Protozoários/genética , Proteínas de Protozoários/imunologia , Sequências Repetitivas de Ácido Nucleico , Homologia de Sequência de Aminoácidos
13.
Cell Death Dis ; 6: e1725, 2015 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-25880092

RESUMO

Disrupting particular mitochondrial fission and fusion proteins leads to the death of specific neuronal populations; however, the normal functions of mitochondrial fission in neurons are poorly understood, especially in vivo, which limits the understanding of mitochondrial changes in disease. Altered activity of the central mitochondrial fission protein dynamin-related protein 1 (Drp1) may contribute to the pathophysiology of several neurologic diseases. To study Drp1 in a neuronal population affected by Alzheimer's disease (AD), stroke, and seizure disorders, we postnatally deleted Drp1 from CA1 and other forebrain neurons in mice (CamKII-Cre, Drp1lox/lox (Drp1cKO)). Although most CA1 neurons survived for more than 1 year, their synaptic transmission was impaired, and Drp1cKO mice had impaired memory. In Drp1cKO cell bodies, we observed marked mitochondrial swelling but no change in the number of mitochondria in individual synaptic terminals. Using ATP FRET sensors, we found that cultured neurons lacking Drp1 (Drp1KO) could not maintain normal levels of mitochondrial-derived ATP when energy consumption was increased by neural activity. These deficits occurred specifically at the nerve terminal, but not the cell body, and were sufficient to impair synaptic vesicle cycling. Although Drp1KO increased the distance between axonal mitochondria, mitochondrial-derived ATP still decreased similarly in Drp1KO boutons with and without mitochondria. This indicates that mitochondrial-derived ATP is rapidly dispersed in Drp1KO axons, and that the deficits in axonal bioenergetics and function are not caused by regional energy gradients. Instead, loss of Drp1 compromises the intrinsic bioenergetic function of axonal mitochondria, thus revealing a mechanism by which disrupting mitochondrial dynamics can cause dysfunction of axons.


Assuntos
Região CA1 Hipocampal/fisiologia , Dinaminas/fisiologia , Mitocôndrias/metabolismo , Neurônios/fisiologia , Animais , Axônios/fisiologia , Região CA1 Hipocampal/metabolismo , Dinaminas/deficiência , Dinaminas/genética , Dinaminas/metabolismo , Metabolismo Energético , Feminino , Masculino , Camundongos , Camundongos Knockout , Neurônios/metabolismo , Sinapses/fisiologia
14.
AIDS ; 14(15): 2273-81, 2000 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-11089615

RESUMO

OBJECTIVE: To determine the overall distribution of drug-resistance mutations to nucleoside reverse transcriptase inhibitors of HIV strains recovered from the lymph nodes (LN) and peripheral blood mononuclear cell (PBMC) compartments of four HIV-infected patients receiving zidovudine and didanosine and to compare them with antiretroviral-naive patients. DESIGN: Molecular comparison of major and minor HIV-1 env and pol region variants residing in LN and PBMC compartments. MATERIALS AND METHODS: Proviral DNA sequences were amplified by PCR from both PBMC and LN compartments, cloned into PGEM-T II Easy vector and sequenced. The clones were subjected to molecular and phylogenetic analysis. RESULTS: Comparison of PBMC and LN-derived HIV-1 variants in the env V3 region showed that nucleotide and amino acid variability was a characteristic feature of LN-derived variants. In contrast, a majority of resistance mutations to reverse transcriptase inhibitors were localized in the PBMC compartment rather than in LN, which is thought to be a reservoir of HIV. CONCLUSIONS: Distinct compartmentalization or independent evolution of pol and env gene variants between LN and PBMC could be due to the differential selection pressure imposed by the combination drug regimen, hence the bimodal distribution of resistance variants between LN and PBMC compartments.


Assuntos
Fármacos Anti-HIV/uso terapêutico , Infecções por HIV/tratamento farmacológico , HIV-1/genética , Leucócitos Mononucleares/virologia , Linfonodos/virologia , Mutação , Didanosina/uso terapêutico , Resistência Microbiana a Medicamentos/genética , Evolução Molecular , Genes env , Genes pol , Variação Genética , Proteína gp120 do Envelope de HIV/genética , Infecções por HIV/sangue , Humanos , Masculino , Fragmentos de Peptídeos/genética , Fatores de Tempo , Zidovudina/uso terapêutico
15.
Immunol Lett ; 61(2-3): 201-4, 1998 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9657276

RESUMO

The route and method used to immunize mice with antigen-expressing DNA plasmids have an impact on the resulting T-helper cell response and IgG subclass distribution. Previous findings further indicate that the intracellular targeting of expressed antigens influences the differentiation of naive T-cells into either a Th1 or a Th2 type of response. In the present study, we analyzed the levels of IgG1 and IgG2a antibodies, as correlates of Th2 and Th1 responses, respectively, after intramuscular injection of mice with plasmids encoding a chimeric protein containing a Plasmodium falciparum blood stage antigen expressed in two different forms. One plasmid expresses the antigen in a secreted form as it is preceded by a signal sequence while expression from the other plasmid, lacking this sequence, results in cytoplasmic localization of the antigen. Mice immunized with the plasmid encoding secreted antigen responded with predominantly IgG1 antibodies. In contrast, sera from mice immunized with the plasmid expressing cytosolic protein displayed a mixed IgG1/IgG2a profile. In line with previous findings, our results suggest that the intracellular targeting of proteins expressed by DNA plasmids is an important factor for the differentiation of Th cells and the resulting subclass pattern of IgG responses.


Assuntos
Anticorpos Antiprotozoários/imunologia , Antígenos de Protozoários/genética , Imunoglobulina G/imunologia , Plasmodium falciparum/imunologia , Sinais Direcionadores de Proteínas/imunologia , Proteínas de Protozoários/genética , Vacinas Protozoárias/imunologia , Vacinas de DNA/imunologia , Animais , Antígenos de Protozoários/imunologia , Vetores Genéticos , Camundongos , Proteínas de Protozoários/imunologia , Vacinação
16.
Neuroreport ; 12(14): 3029-32, 2001 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-11568631

RESUMO

Bacterial DNA and synthetic oligodeoxynucleotides (ODN) containing unmethylated CpG motifs stimulate cells of the immune system to secrete a variety of cytokines and chemokines. This function can be carried out by microglia and astrocytes in the CNS. To evaluate the effect of CpG ODN on microglia and astrocytes, purified cells were isolated and cultured in vitro. CpG ODN rapidly up-regulated their production of IL-1beta, IL-6, IL-12, TNFalpha, MIP-1alpha and/or MIP-1beta. In vivo, systemically administered CpG ODN up-regulated the expression of mRNA encoding cytokines and chemokines in normal mouse brain. These findings suggest that CpG ODN can directly activate immune cells of the CNS.


Assuntos
Astrócitos/efeitos dos fármacos , Quimiocinas/imunologia , Citocinas/imunologia , Gliose/imunologia , Microglia/efeitos dos fármacos , Oligodesoxirribonucleotídeos/farmacologia , Regulação para Cima/imunologia , Animais , Astrócitos/citologia , Astrócitos/imunologia , Células Cultivadas , Sistema Nervoso Central/efeitos dos fármacos , Sistema Nervoso Central/imunologia , Sistema Nervoso Central/metabolismo , Quimiocina CCL3 , Quimiocina CCL4 , Quimiocinas/genética , Citocinas/genética , Relação Dose-Resposta a Droga , Encefalite/induzido quimicamente , Encefalite/imunologia , Encefalite/metabolismo , Gliose/induzido quimicamente , Gliose/metabolismo , Interleucinas/genética , Interleucinas/imunologia , Proteínas Inflamatórias de Macrófagos/genética , Proteínas Inflamatórias de Macrófagos/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Microglia/citologia , Microglia/imunologia , Oligodesoxirribonucleotídeos/imunologia , Oligodesoxirribonucleotídeos/metabolismo , RNA Mensageiro/efeitos dos fármacos , RNA Mensageiro/metabolismo , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/imunologia
17.
Am J Trop Med Hyg ; 60(1): 30-4, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9988318

RESUMO

The genetic diversity displayed by Plasmodiumfalciparum field isolates, the occurrence of variant forms of the parasite at different frequencies in different geographic areas, and the complexity of the infections represent major obstacles for the development of effective malaria control measures. However, since most of the existing studies have been performed in regions where P. falciparum transmission is high, little is known about the diversity and complexity of parasite populations circulating in areas of low malaria endemicity. We investigated the extent of genetic polymorphism in P. falciparum field isolates from Honduras, a region where its transmission is low and seasonal. Allelic diversity was analyzed in the highly polymorphic parasite genes encoding the merozoite surface proteins- (MSP-1) and -2 (MSP-2) and the glutamate-rich protein (GLURP) by the polymerase chain reaction. Gene polymorphism was also assessed in the EB200 region derived from the highly size polymorphic Pf332 gene. Limited size polymorphism was detected in all genes analyzed, with four and three variants for the MSP-1 and MSP-2 alleles, respectively, and two size variants for the GLURP and Pf332 genes. Moreover, based on the studied genetic markers, most infections consisted of only a few genetically distinct parasite clones. These results suggest that the P. falciparum parasite populations circulating in this region are genetically homogeneous and point to an association between the extent of parasite genetic diversity and the intensity of malaria transmission.


Assuntos
Antígenos de Protozoários , Variação Genética , Malária Falciparum/patologia , Parasitemia/parasitologia , Plasmodium falciparum/genética , Alelos , Animais , Antígenos de Superfície/genética , Estudos Transversais , Marcadores Genéticos , Genótipo , Honduras/epidemiologia , Humanos , Malária Falciparum/epidemiologia , Proteína 1 de Superfície de Merozoito/genética , Parasitemia/epidemiologia , Reação em Cadeia da Polimerase , Polimorfismo Genético , Proteínas de Protozoários/genética
18.
FEMS Immunol Med Microbiol ; 18(3): 193-202, 1997 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9271170

RESUMO

The presence of a signal sequence preceding the gene encoding a target antigen in a DNA vaccine should facilitate secretion of the in vivo translated antigen. The immune responses elicited upon injection with such a vector could differ from those induced by the same vector lacking a signal sequence. In the present study, the humoral responses elicited in mice immunized with two plasmids, either containing or lacking the human tissue plasminogen activator signal sequence, were compared. Both plasmids encode the chimeric antigen ZZN4, containing a malaria antigen Pf332-derived sequence (N4) linked to a bacterial fusion partner (ZZ). In vitro transfection of COS cells with each plasmid and treatment of the transfectants with brefeldin A confirmed that secretion of ZZN4 via the endoplasmic reticulum and Golgi pathway only occurred in cells transfected with the signal peptide-encoding plasmid. Repeated intramuscular injections of mice with either of the plasmids elicited comparable antibody responses to ZZN4 with regard to kinetics, specific IgG levels and persistence. These results indicate that in vivo transfection of muscle cells by either of these two plasmids generated comparable levels of antigen available for B-cell recognition and for uptake by antigen-presenting cells, despite the differential intracellular targeting of the encoded antigen. The relevance of these findings for the design of DNA vaccine vectors is discussed.


Assuntos
Anticorpos Antiprotozoários/imunologia , Vacinas Antimaláricas/imunologia , Ativadores de Plasminogênio/imunologia , Plasmodium falciparum/imunologia , Sinais Direcionadores de Proteínas/imunologia , Vacinas de DNA/imunologia , Animais , Anticorpos Antiprotozoários/biossíntese , Células COS , Feminino , Vetores Genéticos , Antígenos H-2/imunologia , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos CBA , Ativadores de Plasminogênio/genética , Sinais Direcionadores de Proteínas/genética , Proteínas de Protozoários/genética , Proteínas de Protozoários/imunologia , Vacinas Sintéticas/genética , Vacinas Sintéticas/imunologia
19.
FEMS Immunol Med Microbiol ; 12(3-4): 175-86, 1995 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8745001

RESUMO

Two different expression systems were investigated for the production of an 80 amino acid polypeptide, M3, from the C-terminus of the Plasmodium falciparum blood stage antigen Pf155/RESA in an attenuated Salmonella typhimurium vaccine strain. Upon expression, the malarial polypeptide was targeted either to the periplasm as a soluble fusion protein containing two IgG-binding domains (ZZ) from the staphylococcal protein A or, to the bacterial surface as an insert within a chimeric outer membrane protein A (OmpA) derived from Escherichia coli and Shigella dysenteriae. Both the ZZM3 and the OmpAM3 proteins were stably expressed in the periplasm or on the surface of Salmonella, respectively. The ZZ expression system yielded 10-100 times more malarial immunogen than did the OmpA system. Live recombinant Salmonella expressing ZZM3 or OmpAM3 were used to immunize mice intraperitoneally. Both the ZZM3 and OmpAM3 genes persisted for up to three weeks in bacteria isolated from different lymphoid organs. Bacteria expressing ZZM3 induced antibodies to M3, ZZ and to the Pf155/RESA antigen whereas, bacteria producing OmpAM3 induced similar levels of antibodies reactive with M3 but not with Pf155/RESA. Both recombinants induced a memory response of antibodies reactive with both M3 and Pf155/RESA. The high levels of M3 produced by the ZZ expression system make it suitable for the expression of heterologous antigens in Salmonella. Nevertheless, in spite of the quantitative difference in M3 expression, the ZZ and OmpA constructs elicited comparable immune responses to M3.


Assuntos
Anticorpos Antiprotozoários/biossíntese , Plasmodium falciparum/imunologia , Proteínas de Protozoários/genética , Proteínas de Protozoários/imunologia , Salmonella typhimurium/genética , Salmonella typhimurium/imunologia , Vacinas Sintéticas , Animais , Antígenos de Protozoários/imunologia , Antígenos de Superfície , Proteínas da Membrana Bacteriana Externa/imunologia , Sequência de Bases , Western Blotting , Camundongos , Camundongos Endogâmicos CBA , Dados de Sequência Molecular , Plasmídeos/genética , Proteínas Recombinantes de Fusão/imunologia , Proteína Estafilocócica A/imunologia
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