RESUMO
The bacterium Francisella tularensis causes the vector-borne zoonotic disease tularemia, and may infect a wide range of hosts including invertebrates, mammals and birds. Transmission to humans occurs through contact with infected animals or contaminated environments, or through arthropod vectors. Tularemia has a broad geographical distribution, and there is evidence which suggests local emergence or re-emergence of this disease in Europe. This review was developed to provide an update on the geographical distribution of F. tularensis in humans, wildlife, domestic animals and vector species, to identify potential public health hazards, and to characterize the epidemiology of tularemia in Europe. Information was collated on cases in humans, domestic animals and wildlife, and on reports of detection of the bacterium in arthropod vectors, from 38 European countries for the period 1992-2012. Multiple international databases on human and animal health were consulted, as well as published reports in the literature. Tularemia is a disease of complex epidemiology that is challenging to understand and therefore to control. Many aspects of this disease remain poorly understood. Better understanding is needed of the epidemiological role of animal hosts, potential vectors, mechanisms of maintenance in the different ecosystems, and routes of transmission of the disease.
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Doenças Transmissíveis Emergentes/epidemiologia , Doenças Transmissíveis Emergentes/veterinária , Francisella tularensis/isolamento & purificação , Tularemia/epidemiologia , Tularemia/veterinária , Zoonoses/epidemiologia , Zoonoses/microbiologia , Animais , Aves , Doenças Transmissíveis Emergentes/microbiologia , Europa (Continente)/epidemiologia , Humanos , Invertebrados , Mamíferos , Topografia Médica , Tularemia/microbiologiaRESUMO
Hemospray is a haemostatic agent licensed for endoscopic haemostasis of non-variceal upper gastrointestinal bleeding (NVUGIB) in Europe and Canada. Hemospray has been shown to be safe and effective in achieving haemostasis in bleeding peptic ulcers in a prospective clinical study and several further case series have described the use of hemospray in other non-variceal causes of gastrointestinal bleeding. Portal hypertensive gastropathy and colopathy are common in patients with portal hypertension. As hemospray is an easy to apply, non-contact method, which can cover large areas of mucosa, it may be of benefit in acute non-variceal portal hypertensive bleeding. We present data from the first four consecutive patients presenting to our institution with acute haemorrhage secondary to non-variceal diffuse portal hypertensive bleeding treated with hemospray.
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Hemorragia Gastrointestinal/etiologia , Hemorragia Gastrointestinal/terapia , Hemostáticos/administração & dosagem , Hipertensão Portal/complicações , Minerais/administração & dosagem , Idoso , Feminino , Hemostase Endoscópica/métodos , Humanos , Cirrose Hepática/complicações , Masculino , Pós/administração & dosagemRESUMO
AIMS: To determine the barriers to and enablers of engaging with specialist diabetes care and the service requirements of young adults with Type 1 diabetes mellitus from a low socio-economic, multicultural region. METHODS: A cross-sectional survey targeted 357 young adults with Type 1 diabetes, aged 18-30 years. Participants completed questions about barriers/enablers to accessing diabetes care and service preferences, self-reported HbA(1c), plus measures of diabetes-related distress (Problem Areas in Diabetes), depression/anxiety (Hospital Anxiety and Depression Scale), and illness perceptions (Brief Illness Perceptions Questionnaire). RESULTS: Eighty-six (24%) responses were received [55 (64%) female; mean ± sd age 24 ± 4 years; diabetes duration 12 ± 7 years; HbA(1c) 68 ± 16 mmol/mol (8.4 ± 1.5%)]. Logistical barriers to attending diabetes care were reported; for example, time constraints (30%), transportation (26%) and cost (21%). However, 'a previous unsatisfactory diabetes health experience' was cited as a barrier by 27%. Enablers were largely matched to overcoming these barriers. Over 90% preferred a multidisciplinary team environment, close to home, with after-hours appointment times. Forty per cent reported severe diabetes-related distress, 19% reported moderate-to-severe depressive symptoms and 50% reported moderate-to-severe anxiety. CONCLUSIONS: Among these young adults with Type 1 diabetes, glycaemic control was suboptimal and emotional distress common. They had identifiable logistical barriers to accessing and maintaining contact with diabetes care services, which can be addressed with flexible service provision. A substantial minority were discouraged by previous unsatisfactory experiences, suggesting health providers need to improve their interactions with young adults. This research will inform the design of life-stage-appropriate diabetes services targeting optimal engagement, access, attendance and ultimately improved healthcare outcomes in this vulnerable population.
Assuntos
Diabetes Mellitus Tipo 1/terapia , Etnicidade , Acessibilidade aos Serviços de Saúde , Fatores Socioeconômicos , Adolescente , Adulto , Ansiedade/epidemiologia , Custos e Análise de Custo , Estudos Transversais , Depressão/epidemiologia , Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 1/psicologia , Feminino , Hemoglobinas Glicadas/análise , Acessibilidade aos Serviços de Saúde/economia , Acessibilidade aos Serviços de Saúde/estatística & dados numéricos , Humanos , Masculino , Inquéritos e Questionários , Fatores de Tempo , Meios de Transporte , Adulto JovemRESUMO
BACKGROUND: Von Hippel-Lindau (VHL) disease induces vascular neoplasms in multiple organs. We evaluated the safety and efficacy of sunitinib in VHL patients and examined the expression of candidate receptors in archived tissue. METHODS: Patients with VHL were given four cycles of 50 mg sunitinib daily for 28 days, followed by 14 days off. Primary end point was toxicity. Modified RECIST were used for efficacy assessment. We evaluated 20 archival renal cell carcinomas (RCCs) and 20 hemangioblastomas (HBs) for biomarker expression levels using laser-scanning cytometry (LSC). RESULTS: Fifteen patients were treated. Grade 3 toxicity included fatigue in five patients. Dose reductions were needed in 10 patients. Eighteen RCC and 21 HB lesions were evaluable. Six of the RCCs (33%) responded partially, versus none of the HBs (P = 0.014). LSC revealed that mean levels of phosphorylated vascular endothelial growth factor receptor-2 were lower in HB than in RCC endothelium (P = 0.003) and mean phosphorylated fibroblast growth factor receptor substrate-2 (pFRS2) levels were higher in HB (P = 0.003). CONCLUSIONS: Sunitinib treatment in VHL patients showed acceptable toxicity. Significant response was observed in RCC but not in HB. Greater expression of pFRS2 in HB tissue than in RCC raises the hypothesis that treatment with fibroblast growth factor pathway-blocking agents may benefit patients with HB.
Assuntos
Antineoplásicos/uso terapêutico , Indóis/uso terapêutico , Pirróis/uso terapêutico , Doença de von Hippel-Lindau/tratamento farmacológico , Adulto , Antineoplásicos/efeitos adversos , Carcinoma de Células Renais/tratamento farmacológico , Carcinoma de Células Renais/metabolismo , Feminino , Hemangioblastoma/tratamento farmacológico , Hemangioblastoma/metabolismo , Humanos , Indóis/efeitos adversos , Neoplasias Renais/tratamento farmacológico , Neoplasias Renais/metabolismo , Masculino , Pessoa de Meia-Idade , Tumores Neuroendócrinos/diagnóstico por imagem , Tumores Neuroendócrinos/tratamento farmacológico , Neoplasias Pancreáticas/diagnóstico por imagem , Neoplasias Pancreáticas/tratamento farmacológico , Projetos Piloto , Pirróis/efeitos adversos , Radiografia , Sunitinibe , Resultado do Tratamento , Adulto JovemRESUMO
The range of possibilities for future climate evolution needs to be taken into account when planning climate change mitigation and adaptation strategies. This requires ensembles of multi-decadal simulations to assess both chaotic climate variability and model response uncertainty. Statistical estimates of model response uncertainty, based on observations of recent climate change, admit climate sensitivities--defined as the equilibrium response of global mean temperature to doubling levels of atmospheric carbon dioxide--substantially greater than 5 K. But such strong responses are not used in ranges for future climate change because they have not been seen in general circulation models. Here we present results from the 'climateprediction.net' experiment, the first multi-thousand-member grand ensemble of simulations using a general circulation model and thereby explicitly resolving regional details. We find model versions as realistic as other state-of-the-art climate models but with climate sensitivities ranging from less than 2 K to more than 11 K. Models with such extreme sensitivities are critical for the study of the full range of possible responses of the climate system to rising greenhouse gas levels, and for assessing the risks associated with specific targets for stabilizing these levels.
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Various methods are currently used to investigate human tissue differentiation, including human embryo culture and studies utilising pluripotent stem cells (PSCs) such as in vitro embryoid body formation and in vivo teratoma assays. Each method has its own distinct advantages, yet many are limited due to being unable to achieve the complexity and maturity of tissue structures observed in the developed human. The teratoma xenograft assay allows maturation of more complex tissue derivatives, but this method has ethical issues surrounding animal usage and significant protocol variation. In this study, we have combined three-dimensional (3D) in vitro cell technologies including the common technique of embryoid body (EB) formation with a novel porous scaffold membrane, in order to prolong cell viability and extend the differentiation of PSC derived EBs. This approach enables the formation of more complex morphologically identifiable 3D tissue structures representative of all three primary germ layers. Preliminary in vitro work with the human embryonal carcinoma line TERA2.SP12 demonstrated improved EB viability and enhanced tissue structure formation, comparable to teratocarcinoma xenografts derived in vivo from the same cell line. This is thought to be due to reduced diffusion distances as the shape of the spherical EB transforms and flattens, allowing for improved nutritional/oxygen support to the developing structures over extended periods. Further work with EBs derived from murine embryonic stem cells demonstrated that the formation of a wide range of complex, recognisable tissue structures could be achieved within 2-3 weeks of culture. Rudimentary tissue structures from all three germ layers were present, including epidermal, cartilage and epithelial tissues, again, strongly resembling tissue structure of teratoma xenografts of the same cell line. Proof of concept work with EBs derived from the human embryonic stem cell line H9 also showed the ability to form complex tissue structures within this system. This novel yet simple model offers a controllable, reproducible method to achieve complex tissue formation in vitro. It has the potential to be used to study human developmental processes, as well as offering an animal free alternative method to the teratoma assay to assess the developmental potential of novel stem cell lines.
RESUMO
A murine cloned Th cell line specific for the antigen conalbumin in the context of self I-A molecules can be activated by low concentrations of soluble antireceptor mAb. By using an antireceptor mAb to shared antigenic determinants on T cell receptors, we have shown that the ability to be activated by soluble antireceptor mAb is an unusual, although not unique, feature of this cloned T cell line. This activation does not involve occult APC, FcR, or interaction between individual cloned T cells, as limiting-dilution analysis shows that individual cells of this clone will grow in the presence of the antireceptor antibody and IL-1 as stimulus. This cloned T cell line is highly immunogenic in vivo, giving rise to antireceptor antibodies that stimulate its growth in both mice and rats. This response is not dependent upon exogenous T cells. Rather, the clone directly interacts with complementary B cells, as shown by the production of mAb in nude mice, and by production of stimulating antireceptor antibodies by purified B cells cultured with cloned Th cells in vitro. Several features of this cloned Th cell line, most especially its ability to be activated, rather than inhibited, by antireceptor antibodies, may account for its striking ability to directly activate B cells bearing complementary receptors. The direct interaction of the cloned Th cell with B cells bearing complementary receptors may serve as a model for receptor-receptor interactions in the generation of both T and B cell repertoires.
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Linfócitos B/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Linfócitos T/imunologia , Animais , Anticorpos Monoclonais/imunologia , Células Produtoras de Anticorpos/imunologia , Comunicação Celular , Linhagem Celular , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos BALB C , Ratos , Ratos EndogâmicosRESUMO
As the field of tissue engineering continues to advance rapidly, so too does the complexity of cell culture techniques used to generate in vitro tissue constructs, with the overall aim of mimicking the in vivo microenvironment. This complexity typically comes at a cost with regards to the size of the equipment required and associated expenses. We have developed a small, low-cost bioreactor system which overcomes some of the issues of typical bioreactor systems while retaining a suitable scale for the formation of complex tissues. Herein, we have tested this system with three cell populations/tissues: the culture of hepatocellular carcinoma cells, where an improved structure and basic metabolic function is seen; the culture of human pluripotent stem cells, in which the cultures can form more heterogeneous tissues resembling the in vivo teratoma and ex vivo liver tissue slices, in which improved maintenance of cellular viability is seen over the 3 days tested. This system has the flexibility to be used for a variety of further uses and has the potential to provide a more accessible alternative to current bioreactor technologies.
RESUMO
A replication-incompetent adenoviral vector encoding the heavy chain C-fragment (H(C)50) of botulinum neurotoxin type C (BoNT/C) was evaluated as a mucosal vaccine against botulism in a mouse model. Single intranasal inoculation of the adenoviral vector elicited a high level of H(C)50-specific IgG, IgG1 and IgG2a in sera and IgA in mucosal secretions as early as 2 weeks after vaccination. The antigen-specific serum antibodies were maintained at a high level at least until the 27th week. Immune sera showed high potency in neutralizing BoNT/C as indicated by in vitro toxin neutralization assay. The mice receiving single dose of 2 x 10(7) p.f.u. (plaque-forming unit) of adenoviral vector were completely protected against challenge with up to 10(4) x MLD(50) of BoNT/C. The protective immunity showed vaccine dose dependence from 10(5) to 2 x 10(7) p.f.u. of adenoviral vector. In addition, animals receiving single intranasal dose of 2 x 10(7) p.f.u. adenoviral vector could be protected against 100 x MLD(50) 27 weeks after vaccination. Animals with preexisting immunity to adenovirus could also be vaccinated intranasally and protected against lethal challenge with BoNT/C. These results suggest that the adenoviral vector is a highly effective gene-based mucosal vaccine against botulism.
Assuntos
Vacinas Bacterianas/imunologia , Toxinas Botulínicas/imunologia , Botulismo/prevenção & controle , Adenoviridae/genética , Animais , Anticorpos Antibacterianos/biossíntese , Botulismo/imunologia , Relação Dose-Resposta Imunológica , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Vetores Genéticos , Imunidade nas Mucosas , Camundongos , Camundongos Endogâmicos BALB C , Vacinação/métodos , Vacinas Sintéticas/imunologiaRESUMO
PURPOSE: There is a need for high quality evidence on the adverse effects of medical interventions to inform policy, practice and research. Methods to systematically review adverse effects have not been fully developed. We aimed to assess the current methods and reporting used by such reviews. METHODS: Survey of general medical, drug safety and pharmacology journals published in 2006. Methods including: searching, inclusion criteria, quality assessment and meta-analysis were assessed. RESULTS: Forty three systematic reviews from 2704 abstracts in 16 journals were included. The search strategy was not reported by 10 (23%) of reviews. The collection and reporting of the adverse effects from primary studies was described by 4/37 (12%) reviews and the quality of included studies was assessed by 15 (35%) of reviews. Meta-analysis on rare outcomes and handling of zero event data were inconsistent. A polarity in the standard of reporting between reviews was observed. The reporting standard we found was similar to another survey of systematic reviews. CONCLUSION: Reporting was poor with respect to searching and definition/collection of adverse effects and guidelines such as QUOROM and MOOSE could be employed by authors. Comprehensive and clear reporting should be enforced by journals. The low proportion of reviews assessing quality, and the inconsistencies observed when modelling rare event data reflect the need for empirical research to underpin methods in these areas.
Assuntos
Bases de Dados Bibliográficas , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Metanálise como Assunto , Literatura de Revisão como Assunto , Coleta de Dados , Interpretação Estatística de Dados , Humanos , Armazenamento e Recuperação da Informação , Controle de QualidadeRESUMO
Food processing surfaces fouled with organic material pose problems ranging from aesthetic appearance, equipment malfunction and product contamination. Despite the importance of organic soiling for subsequent product quality, little is known about the interaction between surfaces and organic soil components. A range of complex and defined food soils was applied to 304 stainless steel (SS) surfaces to determine the effect of type and concentration of soil on surface physicochemical parameters, viz surface hydrophobicity (DeltaG(iwi)), surface free energy (gamma(s)), Lifshitz van der Waals (gamma_LW(s)), Lewis acid base (gamma_AB(s)), electron acceptor (gamma_+(s) ) and electron donor (gamma_-(s) ) measurements. When compared to the control surface, changes in gamma_AB(s), gamma_+(s) and gamma_-(s) were indicative of surface soiling. However, soil composition and surface coverage were heterogeneous, resulting in complex data being generated from which trends could not be discerned. These results demonstrate that the retention of food soil produces changes in the physicochemical parameters of the surface that could be used to indicate the hygienic status of a surface.
Assuntos
Queijo/análise , Peixes , Indústria de Processamento de Alimentos/métodos , Indústria de Processamento de Alimentos/normas , Carne/análise , Aço Inoxidável/química , Animais , Fenômenos Químicos , Contaminação de Equipamentos , Interações Hidrofóbicas e Hidrofílicas , Higiene/normas , Compostos Orgânicos/análise , Propriedades de SuperfícieRESUMO
Botulinum neurotoxin (BoNT), the most poisonous substance known, causes naturally occurring human disease (botulism) and is one of the top six biothreat agents. Botulism is treated with polyclonal antibodies produced in horses that are associated with a high incidence of systemic reactions. Human monoclonal antibodies (mAbs) are under development as a safer therapy. Identifying neutralizing epitopes on BoNTs is an important step in generating neutralizing mAbs, and has implications for vaccine development. Here, we show that the three domains of BoNT serotype A (BoNT/A) can be displayed on the surface of yeast and used to epitope map six mAbs to the toxin domains they bind. The use of yeast obviates the need to express and purify each domain, and it should prove possible to display domains of other BoNT subtypes and serotypes for epitope mapping. Using a library of yeast-displayed BoNT/A binding domain (H(C)) mutants and selecting for loss of binding, the fine epitopes of three neutralizing BoNT/A mAbs were identified. Two mAbs bind the C-terminal subdomain of H(C), with one binding near the toxin sialoganglioside binding site. The most potently neutralizing mAb binds the N-terminal subdomain of H(C), in an area not previously thought to be functionally important. Modeling the epitopes shows how all three mAbs could bind BoNT/A simultaneously and may explain, in part, the dramatic synergy observed on in vivo toxin neutralization when these antibodies are combined. The results demonstrate how yeast display can be used for domain-level and fine mapping of conformational BoNT antibody epitopes and the mapping results identify three neutralizing BoNT/A epitopes.
Assuntos
Anticorpos Antibacterianos/imunologia , Anticorpos Monoclonais/imunologia , Toxinas Botulínicas Tipo A/imunologia , Clostridium botulinum/imunologia , Mapeamento de Epitopos , Biblioteca de Peptídeos , Especificidade de Anticorpos , Complexo Antígeno-Anticorpo , Toxinas Botulínicas Tipo A/química , Humanos , Modelos Moleculares , Mutagênese , Testes de Neutralização , Estrutura Terciária de Proteína , Saccharomyces cerevisiaeRESUMO
Of anthropogenic methane emissions, 40% can be attributed to agriculture, the majority of which are from enteric fermentation in livestock. With international commitments to tackle drivers of climate change, there is a need to lower global methane emissions from livestock production. Gastrointestinal helminths (parasitic worms) are globally ubiquitous and represent one of the most pervasive challenges to the health and productivity of grazing livestock. These parasites influence a number of factors affecting methane emissions including feed efficiency, nutrient use, and production traits. However, their effects on methane emissions are unknown. This is to our knowledge the first study that empirically demonstrates disease-driven increases in methane (CH4) yield in livestock (grams of CH4 per kg of dry matter intake). We do this by measuring methane emissions (in respiration chambers), dry matter intake, and production parameters for parasitised and parasite-free lambs. This study shows that parasite infections in lambs can lead to a 33% increase in methane yield (gâ¯CH4/kg DMI). This knowledge will facilitate more accurate calculations of the true environmental costs of parasitism in livestock, and reveals the potential benefits of mitigating emission through controlling parasite burdens.
Assuntos
Gases de Efeito Estufa/metabolismo , Metano/metabolismo , Doenças dos Ovinos/metabolismo , Doenças dos Ovinos/parasitologia , Trichostrongyloidea/fisiologia , Tricostrongiloidíase/veterinária , Análise de Variância , Ração Animal , Animais , Digestão , Ingestão de Alimentos , Fezes/química , Gases de Efeito Estufa/química , Contagem de Ovos de Parasitas/veterinária , Ovinos , Tricostrongiloidíase/metabolismo , Aumento de PesoRESUMO
BACKGROUND: This study aimed to identify barriers and enablers for dentists managing non-cavitated proximal caries lesions using non- or micro-invasive (NI/MI) approaches rather than invasive and restorative methods in New Zealand, Germany and the USA. METHODS: Semi-structured interviews were conducted, focusing on non-cavitated proximal caries lesions (radiographically confined to enamel or the outer dentine). Twelve dentists from New Zealand, 12 from Germany and 20 from the state of Michigan (USA) were interviewed. Convenience and snowball sampling were used for participant recruitment. A diverse sample of dentists was recruited. Interviews were conducted by telephone, using an interview schedule based on the Theoretical Domains Framework (TDF). RESULTS: The following barriers to managing lesions non- or micro-invasively were identified: patients' lacking adherence to oral hygiene instructions or high-caries risk, financial pressures and a lack of reimbursement for NI/MI, unsupportive colleagues and practice leaders, not undertaking professional development and basing treatment on what had been learned during training, and a sense of anticipated regret (anxiety about not restoring a proximal lesion in its early stages before it progressed). The following enablers were identified: the professional belief that remineralisation can occur in early non-cavitated proximal lesions and that these lesions can be arrested, the understanding that placing restorations weakens the tooth and inflicts a cycle of re-restoration, having up-to-date information and supportive colleagues and work environments, working as part of a team of competent and skilled dental practitioners who perform NI/MI (such as cleaning or scaling), having the necessary resources, undertaking ongoing professional development and continued education, maintaining membership of professional groups and a sense of professional and personal satisfaction from working in the patient's best interest. Financial aspects were more commonly mentioned by the German and American participants, while continuing education was more of a focus for the New Zealand participants. CONCLUSIONS: Decisions on managing non-cavitated proximal lesions were influenced by numerous factors, some of which could be targeted by interventions for implementing evidence-based management strategies in practice.
Assuntos
Tomada de Decisões , Cárie Dentária/terapia , Esmalte Dentário , Odontólogos/psicologia , Padrões de Prática Odontológica/estatística & dados numéricos , Cárie Dentária/classificação , Feminino , Humanos , Entrevistas como Assunto , Masculino , Pesquisa QualitativaRESUMO
BACKGROUND AND PURPOSE: Chronic morphine administration produces tolerance in vivo and attenuation of mu opioid receptor (MOR)-mediated G-protein activation measured in vitro, but the relationship between these adaptations is not clear. The present study examined MOR-mediated G-protein activation in the CNS of mice with different levels of morphine tolerance. EXPERIMENTAL APPROACH: Mice were implanted with morphine pellets, with or without supplemental morphine injections, to induce differing levels of tolerance as determined by a range of MOR-mediated behaviours. MOR function was measured using agonist-stimulated [(35)S]guanylyl-5'-O-(gamma-thio)-triphosphate ([(35)S]GTPgammaS) and receptor binding throughout the CNS. KEY RESULTS: Morphine pellet implantation produced 6-12-fold tolerance in antinociceptive assays, hypothermia and Straub tail, as measured by the ratio of morphine ED(50) values between morphine-treated and control groups. Pellet implantation plus supplemental injections produced 25-50-fold tolerance in these tests. In morphine pellet-implanted mice, MOR-stimulated [(35)S]GTPgammaS binding was significantly reduced only in the nucleus tractus solitarius (NTS) and spinal cord dorsal horn in tissue sections from morphine pellet-implanted mice. In contrast, MOR-stimulated [(35)S]GTPgammaS binding was significantly decreased in most regions examined in morphine pellet+morphine injected mice, including nucleus accumbens, caudate-putamen, periaqueductal gray, parabrachial nucleus, NTS and spinal cord. CONCLUSIONS AND IMPLICATIONS: Tolerance and the regional pattern of apparent MOR desensitization were influenced positively by the level of morphine exposure. These results indicate that desensitization of MOR-mediated G-protein activity is more regionally widespread upon induction of high levels of tolerance, suggesting that this response contributes more to high than low levels of tolerance to CNS-mediated effects of morphine.
Assuntos
Analgésicos Opioides/farmacologia , Tolerância a Medicamentos , Proteínas de Ligação ao GTP/metabolismo , Morfina/farmacologia , Receptores Opioides mu/metabolismo , Analgésicos Opioides/administração & dosagem , Animais , Sítios de Ligação , Sistema Nervoso Central , Relação Dose-Resposta a Droga , Guanosina 5'-O-(3-Tiotrifosfato) , Hipotermia/induzido quimicamente , Masculino , Camundongos , Morfina/administração & dosagem , Medição da Dor , Células do Corno Posterior , Núcleo Solitário , Cauda/efeitos dos fármacosRESUMO
Most patients with Parkinson's disease (PD) develop dyskinesia and other motor complications after prolonged L-dopa use. We now report on the relationship between L-dopa dose and the duration and severity of dyskinesia in L-dopa-primed MPTP-treated primates with marked nigral degeneration mimicking late stage PD. With increasing doses of L-dopa, locomotor activity increased and motor disability declined. The duration of dyskinesia following L-dopa administration increased dose-dependently, and showed a linear correlation with total locomotor activity. In addition, the time-course of dyskinesia paralleled closely that of locomotor activity in a dose-dependent manner. In contrast, severity of dyskinesia showed a non-linear correlation with total locomotor activity, low doses of L-dopa eliciting severe dyskinesia for short periods of time. The threshold for dyskinesia induction and the antiparkinsonian effects of L-dopa appear very similar in primed MPTP primates mimicking late stage PD. Reducing individual doses of L-dopa to avoid severe dyskinesia can markedly compromise the antiparkinsonian response. Our results extend the relevance of the dyskinetic MPTP-treated primate in studying the genesis of involuntary movements occurring in L-dopa treated patients with PD.
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Discinesia Induzida por Medicamentos/fisiopatologia , Levodopa/administração & dosagem , Intoxicação por MPTP/fisiopatologia , Animais , Callithrix , Relação Dose-Resposta a Droga , Feminino , Levodopa/toxicidade , Masculino , Atividade Motora/efeitos dos fármacos , Atividade Motora/fisiologia , Índice de Gravidade de DoençaRESUMO
The structural organization of intracisternal A-particle genes has been studied, using isolates from a mouse gene library in lambda phage Charon 4A. The predominant gene form among the isolates was 7.3 kilobases (kb) in length. R-loops between the 7-kb (35S) A-particle genomic ribonucleic acid and several of these genes were colinear, with no visible evidence of intervening deoxyribonucleic acid sequences. One recombinant was found with an A-particle gene that contained a 1.7-kb deletion. Using the deletion as a reference, the deoxyribonucleic acid and ribonucleic acid homology regions were localized with respect to one another and to the restriction map: the 5' terminus of the ribonucleic acid was several hundred base pairs within the 5' end of the deoxyribonucleic acid homology region. Restriction endonuclease fragments encompassing the 5' and 3' regions of one 7.3-kb gene were separately subcloned into pBR322. Heteroduplexes between the two subclones revealed an approximately 300-base pair segment of terminally redundant sequences. The cloned 3' fragment hybridized with restriction fragments from the 5' end of several other A-particle genes, demonstrating the presence of common (though not necessarily identical) terminally repeated sequences. A-particle genes varied in the occurrence of specific restriction sites at characteristic internal loci. However, heteroduplexes between several variant 7.3-kb genes showed continuous homology regions even when spread under stringent hybridization conditions. The relative abundance of restriction site variants was highly conserved in 12 laboratory strains of Mus musculus, in embryonic and adult tissues of a single inbred strain, and in the SC-1 cell line of feral mouse origin, but appeared to differ in a feral Japanese substrain, Mus musculus molossinus. Some evidence suggests that subsets of A-particle genes may have similar flanking sequences. The results are discussed in terms of the evolution of this multigene family.
Assuntos
Genes de Partícula A Intracisternal , Genes Virais , Camundongos/genética , Proto-Oncogenes , Retroviridae/genética , Animais , Evolução Biológica , Linhagem Celular , Mapeamento Cromossômico , DNA/genética , DNA/ultraestrutura , Masculino , Camundongos/microbiologia , Camundongos Endogâmicos , Família Multigênica , Sequências Repetitivas de Ácido NucleicoRESUMO
BACKGROUND: There are a number of different drug treatments for acute migraine, including currently four triptans, with several more likely to become available in the future. There is a need for evidence-based information to help determine the balance of benefit and harm for acute migraine treatment. OBJECTIVES: To quantitatively assess the efficacy of a single dose of rizatriptan (Maxalt) for treating a single migraine attack using the outcomes of headache response and pain-free response at half-an-hour, one hour, two hours, and sustained relief over 24 hours. To express efficacy in terms of numbers-needed-to-treat (NNTs). SEARCH STRATEGY: Trials were identified by searching MEDLINE (1966-July 2000), EMBASE (1980-June 2000), the Cochrane Library (Issue 3, 2000) and the Oxford Pain Relief Database (1950-1994). Date of last search: July 2000. SELECTION CRITERIA: The inclusion criteria were randomised, placebo-controlled trials of rizatriptan for acute migraine; double-blind design; International Headache Society diagnostic criteria for migraine with or without aura; single migraine attack; single-dose treatment at standard doses; adult population; baseline pain of moderate or severe intensity using a four-point standardised rating scale; dichotomous or percentage data for at least one of the main efficacy outcomes; and full journal publication. DATA COLLECTION AND ANALYSIS: Main outcomes considered were i) headache response at two hours, ii) headache response at one hour, iii) pain-free response at two hours, iv) sustained relief over 24 hours, v) pain-free response at 24 hours and vi) adverse effects. Minor outcomes were headache response and pain-free response at half-an-hour and four hours, and pain-free response at one hour. Dichotomous or percentage data were extracted and used to calculate the relative benefit (RB) and number-needed-to-treat (NNT) for each outcome. MAIN RESULTS: Seven trials met our inclusion criteria, with 2626 patients given rizatriptan and 902 given placebo. Significant benefit of rizatriptan over placebo was shown for both doses of rizatriptan (5 mg and 10 mg) for all five main efficacy outcomes (ranging from one to 24 hours). A dose response was seen for the main outcomes. It was not possible to analyse adverse effects information in a meaningful way. AUTHORS' CONCLUSIONS: Rizatriptan 5 mg and 10 mg are effective in treating acute migraine, with a dose-related increase in efficacy.
Assuntos
Transtornos de Enxaqueca/tratamento farmacológico , Agonistas do Receptor de Serotonina/uso terapêutico , Triazóis/uso terapêutico , Doença Aguda , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto , TriptaminasRESUMO
BACKGROUND: Eletriptan (Relpax) is a new triptan soon to be made available by prescription for the treatment of acute migraine. Currently five triptans are available by prescription and more are under development. In light of the many drugs for treating acute migraine, there is a need for evidence-based assessments to help determine the relative efficacy and harm of these treatments. OBJECTIVES: To determine the efficacy of eletriptan for treating a single migraine attack using the outcomes of headache response and pain-free response at 0.5, 1, 2 and 4 hours, and sustained relief over 24 hours. To express efficacy in terms of number-needed-to-treat (NNT). To determine the adverse effects of a single dose of eletriptan and express this in terms of number-needed-to-harm (NNH). To allow for the comparison of the efficacy of eletriptan with other migraine treatments evaluated systematically in the same way. SEARCH STRATEGY: Data from all Phase III randomised placebo-controlled trials were made available by the manufacturer, Pfizer Inc. To date, these trials comprise the only data on eletriptan relevant to this review in a published or unpublished form; thus, searches of electronic databases for further trials of eletriptan were not conducted. Date of last search: January 2000. SELECTION CRITERIA: Trials of eletriptan for acute migraine; randomised allocation to treatment groups, including a placebo group; double-blind design; International Headache Society diagnostic criteria for migraine with or without aura; single migraine attack; single-dose treatment at standard doses; adult population; baseline pain of moderate or severe intensity using a 4-point standardised rating scale (0 = no pain, 1 = mild pain, 2 = moderate pain and 3 = severe pain); and dichotomous or percentage data for at least one of the main efficacy outcomes. DATA COLLECTION AND ANALYSIS: Trials were scored for quality and data extracted by two independent reviewers. Dichotomous or percentage data were extracted and pooled to calculate the relative benefit (RB) or relative risk (RR) and NNTs or NNHs for a number of outcomes for eletriptan 20 mg, 40 mg and 80 mg. The main outcomes considered were headache response at 1 and 2 hours, pain-free response at 2 hours, sustained relief over 24 hours and adverse effects. Minor outcomes considered were headache response at 0.5 and 4 hours, and pain-free response at 0.5, 1 and 4 hours. MAIN RESULTS: Six trials met the inclusion criteria. Significant benefit of eletriptan over placebo was shown for eletriptan 20 mg, 40 mg and 80 mg for the primary efficacy outcomes of headache response and pain-free response at 2 hours. For headache response at 2 hours, the NNTs (with 95% confidence intervals) were 4.4 (3.4 to 6.2), 2.9 (2.6 to 3.3) and 2.6 (2.4 to 3.0) for eletriptan 20 mg, 40 mg and 80 mg, respectively. For pain-free response at 2 hours, the NNTs were 9.9 (6.9 to 18), 4.0 (3.6 to 4.5) and 3.7 (3.4 to 4.2), for eletriptan 20 mg, 40 and 80 mg, respectively. There was no significant difference in the incidence of major adverse effects between any dose of eletriptan and placebo. The incidence of minor adverse effects was significantly higher for all eletriptan doses than for placebo, with NNHs of 11 (95% confidence interval, 6.2 to 39), 7.0 (5.2 to 11) and 3.7 (3.1 to 4.5) for eletriptan 20 mg, 40 mg and 80 mg, respectively. AUTHORS' CONCLUSIONS: Eletriptan 20 mg, 40 mg and 80 mg are effective for the treatment of an acute migraine attack. Effectiveness is dose-related, with statistically significant differences between doses for pain-free response and 24-hour outcomes. Eletriptan compares well with other triptans available for outcomes measured up to 2 hours and provides meaningful relief for 24 hours. Taken as a single dose, eletriptan was well tolerated and caused no major harm. The incidence of minor harm was dose-dependent, with 80 mg giving significantly more adverse effects than 40 mg.