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1.
Front Cell Dev Biol ; 9: 667246, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34026759

RESUMO

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.

2.
Interface Focus ; 10(2): 20190090, 2020 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-32194933

RESUMO

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.

3.
Int J Parasitol ; 48(13): 1017-1021, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30107148

RESUMO

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 (g 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 Peso
4.
Implement Sci ; 13(1): 54, 2018 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-29625615

RESUMO

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 Qualitativa
5.
Prog Mol Biol Transl Sci ; 144: 121-168, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27865457

RESUMO

Cancer has been recognized for thousands of years. Egyptians believed that cancer occurred at the will of the gods. Hippocrates believed human disease resulted from an imbalance of the four humors: blood, phlegm, yellow bile, and black bile with cancer being caused by excess black bile. The lymph theory of cancer replaced the humoral theory and the blastema theory replaced the lymph theory. Rudolph Virchow was the first to recognize that cancer cells like all cells came from other cells and believed chronic irritation caused cancer. At the same time there was a belief that trauma caused cancer, though it never evolved after many experiments inducing trauma. The birth of virology occurred in 1892 when Dimitri Ivanofsky demonstrated that diseased tobacco plants remained infective after filtering their sap through a filter that trapped bacteria. Martinus Beijerinck would call the tiny infective agent a virus and both Dimitri Ivanofsky and Marinus Beijerinck would become the fathers of virology. Not to long thereafter, Payton Rous founded the field of tumor virology in 1911 with his discovery of a transmittable sarcoma of chickens by what would come to be called Rous sarcoma virus or RSV for short. The first identified human tumor virus was the Epstein-Barr virus (EBV), named after Tony Epstein and Yvonne Barr who visualized the virus particles in Burkitt's lymphoma cells by electron microscopy in 1965. Since that time, many viruses have been associated with carcinogenesis including the most studied, human papilloma virus associated with cervical carcinoma, many other anogenital carcinomas, and oropharyngeal carcinoma. The World Health Organization currently estimates that approximately 22% of worldwide cancers are attributable to infectious etiologies, of which viral etiologies is estimated at 15-20%. The field of tumor virology/viral carcinogenesis has not only identified viruses as etiologic agents of human cancers, but has also given molecular insights to all human cancers including the oncogene activation and tumor suppressor gene inactivation.


Assuntos
Carcinogênese/patologia , Vírus/metabolismo , Animais , Humanos
6.
Epidemiol Infect ; 143(10): 2137-60, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25266682

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.


Assuntos
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/microbiologia
8.
Minerva Med ; 105(5): 413-21, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25000220

RESUMO

As the use of cross-sectional imaging increases so does the incidence of asymptomatic pancreatic cysts. Pancreatic neoplastic cysts can be broadly grouped into mucinous lesions and solid pseudopapillary neoplasms, which have malignant potential and serous lesions, which have negligible malignant potential. Non-neoplastic pancreatic cysts such as pseudocysts are not associated with malignant potential. It is important to identify those mucinous lesions with the highest potential of malignancy as identifying these lesions may allow prevention or early treatment of pancreatic carcinoma. The preoperative diagnosis of these cysts remains challenging with imaging alone often proving inadequate at making the diagnosis. Endoscopic ultrasound (EUS) can assess the morphology of cysts including identification of malignant characteristics of cysts as well as allowing aspiration of cyst fluid, which can be analysed for cytology, mucin, tumour markers, amylase and DNA analysis. Intraductal papillary mucinous neoplasms (IPMNs) can be subdivided into main duct IPMNs (MD-IPMN), branch duct IPMNs (BD-IPMN) and mixed type IPMNs which have feature of both the aforementioned. MD-IPMNs have the highest malignant potential and are often easier to identify on cross-sectional imaging due to the involvement of the main pancreatic duct. BD-IPMNs however can be difficult to distinguish from non-mucinous lesions such as pseudocysts, serous cyst adenomas and other benign cysts such as duplication cysts and in this group of lesions EUS is a valuable tool both to aid diagnosis and to identify BD-IPMNs, which should be considered for surgical resection.


Assuntos
Adenocarcinoma Mucinoso/diagnóstico por imagem , Carcinoma Ductal Pancreático/diagnóstico por imagem , Carcinoma Papilar/diagnóstico por imagem , Endossonografia , Neoplasias Pancreáticas/diagnóstico por imagem , Pseudocisto Pancreático/diagnóstico por imagem , Amilases/análise , Biomarcadores Tumorais/análise , Transformação Celular Neoplásica , Meios de Contraste , DNA de Neoplasias/análise , Aspiração por Agulha Fina Guiada por Ultrassom Endoscópico , Endossonografia/métodos , Humanos , Pseudocisto Pancreático/patologia , Fosfolipídeos , Vigilância da População , Valor Preditivo dos Testes , Hexafluoreto de Enxofre
9.
J Hepatol ; 60(2): 457-60, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24140803

RESUMO

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.


Assuntos
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 & dosagem
10.
Vet J ; 198(1): 267-70, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24075203

RESUMO

There is increasing evidence that the European wild rabbit (Oryctolagus cuniculus) is a wildlife reservoir for paratuberculosis and infected populations may contribute to the persistence of infection in livestock. The aim of this study was to test the hypothesis that farms with difficulties controlling paratuberculosis in their cattle herds have a higher prevalence of Mycobacterium avium subsp. paratuberculosis (MAP) infection in their rabbit populations. A total of 281 rabbits from 13 beef farms in the East of Scotland were randomly sampled in early spring 2007. Participating farms were in paratuberculosis control programmes under the Premium Cattle Health Scheme (PCHS), and were classified as 'responder' (paratuberculosis under control) or 'low responder' (a persistent number of paratuberculosis-positive cattle despite control measures in place) farms. Of the rabbits sampled, 23.8% tested positive for MAP, with those on 'low responder' farms having a greater probability of being infected (0.4) relative to rabbits on 'responder' farms (0.1). The association suggests that MAP-infected rabbits may contribute to the persistence of paratuberculosis in domestic livestock and undermine control strategies that focus on livestock alone. This study provides the first evidence of an association between the persistence of paratuberculosis in livestock despite the implementation of disease control strategies, and MAP-infected sympatric wild rabbit populations.


Assuntos
Doenças dos Bovinos/epidemiologia , Reservatórios de Doenças/veterinária , Mycobacterium avium subsp. paratuberculosis/isolamento & purificação , Paratuberculose/epidemiologia , Coelhos , Animais , Bovinos , Doenças dos Bovinos/microbiologia , Doenças dos Bovinos/prevenção & controle , Reservatórios de Doenças/microbiologia , Feminino , Masculino , Paratuberculose/microbiologia , Paratuberculose/prevenção & controle , Reação em Cadeia da Polimerase/veterinária , Prevalência , Escócia/epidemiologia
11.
Diabet Med ; 30(7): 878-84, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23659590

RESUMO

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 Jovem
12.
J Anim Sci ; 91(8): 3733-41, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23658359

RESUMO

To reduce reliance on imported soybean meal (SBM) in temperate environments, pea and faba bean may be alternative protein sources for pig diets. We assessed the effects of dietary pea and faba bean inclusion on grower and finisher pig performance and carcass quality. There were 9 dietary treatments tested on both grower (30 to 60 kg) and finisher (60 to 100 kg) pigs in a dose response feeding trial. The control diet included SBM at 14 and 12% for grower and finisher pigs, respectively, whereas in the test diets, pea or faba bean were included at 7.5, 15, 22.5, and 30%, gradually and completely replacing SBM. Diets were formulated to be isoenergetic for NE and with the same standard ileal digestible Lys content. After a 1-wk adaptation period, each diet was available on an ad libitum basis to 4 pens of pigs with 4 pigs per pen (2 entire males and 2 females) for 4 wk. Weekly BW for individual pigs, and pen intakes were recorded to assess ADG, ADFI, and G:F. Finisher pigs were then slaughtered at a commercial slaughter house to record carcass quality and assess skatole and indole concentration in the backfat. There were no effects (P > 0.10) on grower ADG, ADFI, and G:F, but pulse inclusion reduced finisher ADG (P = 0.04), with a quadratic effect of pulse inclusion (P = 0.03), as ADG tended to be reduced over initial inclusion levels only. There were no associated effects (P > 0.10) on ADFI or G:F, and pea and faba bean diets resulted in similar finisher performance. Increasing pulse inclusion linearly increased fecal DM content both in grower pigs (P = 0.02) and finisher pigs (P < 0.01). There were no effects on carcass quality or backfat skatole concentrations, but indole concentration was linearly reduced with increasing pulse inclusion (P = 0.05). It is concluded that pea and faba bean may be a viable alternative to SBM in grower and finisher pig diets.


Assuntos
Ração Animal/análise , Dieta/veterinária , Fabaceae/classificação , Suínos/crescimento & desenvolvimento , Fenômenos Fisiológicos da Nutrição Animal , Animais , Composição Corporal/efeitos dos fármacos , Feminino , Masculino
14.
Aliment Pharmacol Ther ; 37(6): 613-21, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23347334

RESUMO

BACKGROUND: As a non-invasive marker of gastrointestinal inflammation, faecal calprotectin (FC) is being increasingly used to guide the management of Crohn's disease. It is therefore a concern that studies have shown variability in day to day levels. AIM: To determine the degree of this intrapersonal variability in the context of quiescent Crohn's disease. METHODS: A single-centre prospective study was undertaken in 143 Crohn's disease patients in clinical remission. Three faecal calprotectin levels were analysed from stool samples on consecutive days. Consistency of faecal calprotectin levels was determined by measuring the intraclass correlation (ICC). Due to higher variability at higher faecal calprotectin levels, the ICC was calculated for the log-transformed values. The reliability of detecting a 'case' of active inflammation as defined for specific concentrations of faecal calprotectin was measured by the kappa statistic. RESULTS: Ninety-eight complete sets of results were obtained. The ICC was 0.84 (95% CI: 0.79-0.89), which represents low variability across samples. The kappa statistic for the reliability of detecting a case as defined by an FC level of >50 µg/g was substantial at 0.648 (0.511-0.769). CONCLUSIONS: Day to day variability of faecal calprotectin is low in our cohort of quiescent Crohn's disease patients and the reliability of defining a 'case' is moderately good. These data provide reassurance to clinicians using a single calprotectin sample to inform therapeutic strategies in this cohort.


Assuntos
Biomarcadores/análise , Doença de Crohn/diagnóstico , Fezes/química , Complexo Antígeno L1 Leucocitário/análise , Adulto , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Reprodutibilidade dos Testes
15.
Ann Oncol ; 22(12): 2661-2666, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22105611

RESUMO

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 Jovem
16.
Protein Eng Des Sel ; 24(3): 321-31, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21149386

RESUMO

Botulism, a disease of humans characterized by prolonged paralysis, is caused by botulinum neurotoxins (BoNTs), the most poisonous substances known. There are seven serotypes of BoNT (A-G) which differ from each other by 34-64% at the amino acid level. Each serotype is uniquely recognized by polyclonal antibodies, which originally were used to classify serotypes. To determine if there existed monoclonal antibodies (mAbs) capable of binding two or more serotypes, we evaluated the ability of 35 yeast-displayed single-chain variable fragment antibodies generated from vaccinated humans or mice for their ability to bind multiple BoNT serotypes. Two such clonally related human mAbs (1B18 and 4E17) were identified that bound BoNT serotype A (BoNT/A) and B or BoNT/A, B, E and F, respectively, with high affinity. Using molecular evolution techniques, it proved possible to both increase affinity and maintain cross-serotype reactivity for the 4E17 mAb. Both 1B18 and 4E17 bound to a relatively conserved epitope at the tip of the BoNT translocation domain. Immunoglobulin G constructed from affinity matured variants of 1B18 and 4E17 were evaluated for their ability to neutralize BoNT/B and E, respectively, in vivo. Both antibodies potently neutralized BoNT in vivo demonstrating that this epitope is functionally important in the intoxication pathway. Such cross-serotype binding and neutralizing mAbs should simplify the development of antibody-based BoNT diagnostics and therapeutics.


Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Especificidade de Anticorpos , Toxinas Botulínicas/imunologia , Sequência de Aminoácidos , Animais , Anticorpos Monoclonais/química , Anticorpos Monoclonais/genética , Anticorpos Neutralizantes/química , Afinidade de Anticorpos , Toxinas Botulínicas/química , Células CHO , Sequência Conservada , Cricetinae , Cricetulus , Reações Cruzadas , Evolução Molecular Direcionada , Mapeamento de Epitopos , Epitopos/imunologia , Feminino , Humanos , Imunoglobulina G/imunologia , Camundongos , Dados de Sequência Molecular , Estrutura Terciária de Proteína , Anticorpos de Cadeia Única/genética , Anticorpos de Cadeia Única/imunologia
17.
Eur Neuropsychopharmacol ; 20(8): 582-93, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20434890

RESUMO

Partial D(2/3) dopamine (DA) receptor agonists provide a novel approach to the treatment of the motor symptoms of Parkinson's disease (PD) that may avoid common dopaminergic side-effects, including dyskinesia and psychosis. The present study focussed on the in vivo pharmacological and therapeutic characterisation of the novel D(2/3) receptor partial agonist and full 5-HT(1A) receptor agonist pardoprunox (SLV308; 7-[4-methyl-1-piperazinyl]-2(3H)-benzoxazolone monochloride). Pardoprunox induced contralateral turning behaviour in rats with unilateral 6-hydroxydopamine-induced lesions of the substantia nigra pars compacta (SNpc) (MED=0.03mg/kg; po). In 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated common marmosets, pardoprunox dose-dependently increased locomotor activity (MED=0.03mg/kg; po) and decreased motor disability (MED=0.03mg/kg; po). The effects of pardoprunox were reversed by the D(2) antagonist sulpiride. In contrast pardoprunox attenuated novelty-induced locomotor activity (MED=0.01mg/kg; po), (+)-amphetamine-induced hyperlocomotion (MED=0.3mg/kg; po) and apomorphine-induced climbing (MED=0.6mg/kg; po) in rodents. Pardoprunox also induced 5-HT(1A) receptor-mediated behaviours, including flat body posture and lower lip retraction (MED=0.3mg/kg; po) and these were reversed by the 5-HT(1A) receptor antagonist WAY100635. Collectively, these findings demonstrate that pardoprunox possesses dopamine D2/3 partial agonist effects, 5-HT1A agonist effects and reduces parkinsonism in animal models. functional DA D(2) receptor partial agonist activity and is effective in experimental models predictive of efficacy in PD. The presence of functional 5-HT(1A) agonist activity might confer anti-dyskinetic activity and have effects that control neuropsychiatric components of PD.


Assuntos
Benzoxazóis/farmacologia , Agonistas de Dopamina/farmacologia , Transtornos Parkinsonianos/tratamento farmacológico , Piperazinas/farmacologia , Receptores de Dopamina D2/agonistas , Receptores de Dopamina D3/agonistas , Agonistas do Receptor 5-HT1 de Serotonina , Animais , Apomorfina/farmacologia , Callithrix , Feminino , Masculino , Camundongos , Atividade Motora/efeitos dos fármacos , Oxidopamina , Transtornos Parkinsonianos/fisiopatologia , Transtornos Parkinsonianos/psicologia , Ratos , Ratos Wistar , Receptor 5-HT1A de Serotonina/metabolismo , Receptores de Dopamina D2/metabolismo , Receptores de Dopamina D3/metabolismo , Sulpirida/farmacologia
18.
Protein Eng Des Sel ; 23(4): 311-9, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20156888

RESUMO

Botulism is caused by the botulinum neurotoxins (BoNTs), the most poisonous substance known. Because of the high potency of BoNT, development of diagnostic and therapeutic antibodies for botulism requires antibodies of very high affinity. Here we report the use of yeast mating to affinity mature BoNT antibodies by light chain shuffling. A library of immunoglobulin light chains was generated in a yeast vector where the light chain is secreted. The heavy chain variable region and the first domain of the constant region (V(H)-C(H)1) from a monoclonal antibody was cloned into a different yeast vector for surface display as a fusion to the Aga2 protein. Through yeast mating of the two haploid yeasts, a library of light chain-shuffled Fab was created. Using this approach, the affinities of one BoNT/A and two BoNT/B scFv antibody fragments were increased from 9- to more than 77-fold. Subcloning the V-genes from the affinity-matured Fab yielded fully human IgG1 with equilibrium binding constants for BoNT/A and BoNT/B of 2.51 x 10(-11) M or lower for all three monoclonal antibodies. This technique provides a rapid route to antibody affinity maturation.


Assuntos
Anticorpos Monoclonais/genética , Toxinas Botulínicas/imunologia , Embaralhamento de DNA , Saccharomyces cerevisiae/genética , Anticorpos Monoclonais/química , Anticorpos Monoclonais/imunologia , Afinidade de Anticorpos , Epitopos/química , Epitopos/imunologia , Humanos , Saccharomyces cerevisiae/metabolismo
19.
Exp Neurol ; 221(1): 79-85, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19833125

RESUMO

We previously showed that continuous infusion of rotigotine resulted in less dyskinesia than repeated pulsatile rotigotine administration or repeated oral administration of L-DOPA in MPTP-treated marmosets. Now we investigate whether continuous rotigotine delivery modifies established dyskinesia induced by prior exposure to repeated pulsatile administration of L-DOPA or rotigotine in MPTP-treated common marmosets. Repeated oral administration of L-DOPA or subcutaneous bolus administration of rotigotine over 28 days improved motor deficits but resulted in the onset of dyskinesia of moderate intensity. When these animals were switched to a 28-day continuous infusion of rotigotine, the reversal of motor disability was maintained. In those animals initially treated with L-DOPA, there was a small reduction in dyskinesia intensity but a significant reduction in the duration of dyskinesia. However, in animals initially treated with repeated bolus administration of rotigotine, dyskinesia intensity was significantly reduced. Initial treatment with a continuous infusion of rotigotine for 28 days reversed motor disability and resulted in a low incidence of dyskinesia. On switching to repeated oral administration of L-DOPA, the improvement in motor disability was maintained but the propensity of L-DOPA to provoke dyskinesia was not affected. In addition, while the continuous delivery of rotigotine prevented the expression of dyskinesia, the previously demonstrated ability of dopamine agonists to prime for dyskinesia could not be avoided. These data suggest that dyskinesia induced by pulsatile drug treatment may be improved by switching to continuous rotigotine delivery. In addition, while continuous delivery of rotigotine may prime for dyskinesia, it does not lead to its expression.


Assuntos
Dopaminérgicos/administração & dosagem , Dopaminérgicos/farmacologia , Discinesia Induzida por Medicamentos , Levodopa/efeitos adversos , Atividade Motora/efeitos dos fármacos , Tetra-Hidronaftalenos/administração & dosagem , Tetra-Hidronaftalenos/farmacologia , Tiofenos/administração & dosagem , Tiofenos/farmacologia , Animais , Callithrix , Avaliação da Deficiência , Modelos Animais de Doenças , Dopaminérgicos/efeitos adversos , Esquema de Medicação , Sistemas de Liberação de Medicamentos , Feminino , Intoxicação por MPTP/tratamento farmacológico , Masculino , Estatísticas não Paramétricas , Tetra-Hidronaftalenos/efeitos adversos , Tiofenos/efeitos adversos , Fatores de Tempo
20.
J Affect Disord ; 122(1-2): 1-9, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19926140

RESUMO

BACKGROUND: Our aim was to analyse existing data on the efficacy and tolerability of valproate for the treatment of acute bipolar depression. METHODS: Randomized controlled trials comparing valproate with placebo were identified using searches of electronic databases in October 2008. Outcomes investigated were depression, anxiety, hypomania, attrition, and adverse events. Trial quality was assessed, and data were summarized using meta-analyses. RESULTS: Four randomized, controlled, doubleblind trials of 142 participants were included. Trial quality was good, although individual study sample sizes were small. Study duration was six weeks (2 studies) and eight weeks (2 studies). Meta-analysis showed a significant difference in favour of valproate for reduction in depressive symptoms, both on depression symptom scales (standardized mean difference (SMD) -0.35 (95% confidence interval, -0.69, -0.02)), and participants with at least 50% improvement in symptoms - relative risk (RR) 2.00 (1.13, 3.53). Effects on anxiety symptoms were small, SMD -0.32 (-0.72, 0.08) and inconclusive (p=0.12). No evidence of a difference in mania symptoms, withdrawal for any reason, lack of effectiveness or adverse events was detected. Nausea occurred more frequently with valproate compared with placebo though the difference was not significant, RR 2.01 (0.98, 4.11). Other adverse events occurring more frequently with valproate (somnolence, fatigue/muscle weakness, headache, diarrhoea and dry mouth) did not differ significantly between treatment groups. LIMITATIONS: Sample sizes were small warranting a larger study to confirm or disprove these findings. CONCLUSIONS: Valproate is effective for the reduction of depressive symptoms of acute bipolar depression, and was well tolerated.


Assuntos
Anticonvulsivantes/uso terapêutico , Transtorno Bipolar/tratamento farmacológico , Ácido Valproico/uso terapêutico , Doença Aguda , Afeto/efeitos dos fármacos , Anticonvulsivantes/efeitos adversos , Transtorno Bipolar/diagnóstico , Transtorno Bipolar/psicologia , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto , Resultado do Tratamento , Ácido Valproico/efeitos adversos
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