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1.
Vet Parasitol Reg Stud Reports ; 49: 101005, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38462306

RESUMO

Flystrike remains an important animal health issue on New Zealand sheep farms. To date no useful predictive tool to assist farmers to develop control options has been available. The aim of this study was to use National Institute of Water and Atmospheric Research (NIWA) virtual climate station data in New Zealand to develop a weather-based model to accurately predict the presence of Lucilia spp. on sheep farms throughout New Zealand. Three LuciTrap® baited fly traps were positioned on each of eight sheep farms throughout New Zealand (5 in the North Island and 3 in the South Island). The traps were put out for both the 2018-2019 and 2019-2020 seasons. They were emptied each week and the flies morphologically identified; with the counts of Lucilia cuprina and L. sericata combined as Lucilia spp. The count data for Lucilia spp. for each week of trapping was transformed into a binary outcome and a generalised linear mixed effects models fitted to the data, with farm as a random effect. The dependent variable was Lucilia spp. flies caught, yes or no, and the independent variables were mean weekly climate variables from the nearest NIWA virtual climate station to that farm. The model was trained on the 2018-2019 catch data and tested on the 2019-2020 catch data. A cut point was identified which maximised the model's ability to correctly predict whether Lucilia spp. were present or not for the 2019-2020 catch data, and the sensitivity, specificity, accuracy, and area under the curve (AUC) of the model calculated. The final model included just 3 significant variables, mean weekly 10 cm soil temperature, mean weekly soil moisture index, and mean weekly wind speed at 10 m. Mean weekly 10 cm soil temperature accounted for 64.7% of the variance explained by the model, mean weekly soil moisture index 34.7% and mean weekly wind speed at 10 m only 0.6%. The results showed that the predictive model had a sensitivity of 0.93 (95% CI = 0.80-0.98) and a specificity of 0.75 (95% CI = 0.62-0.85), using a cut point for the probability of Lucilia spp. being present on farm = 0.383. This model provides New Zealand farmers with a tool which will allow them to know when Lucilia spp. flies will likely be present and thus more accurately plan their interventions to prevent flystrike.


Assuntos
Dípteros , Miíase , Animais , Ovinos , Fazendas , Nova Zelândia/epidemiologia , Tempo (Meteorologia) , Miíase/veterinária , Calliphoridae , Solo
2.
Support Care Cancer ; 31(8): 459, 2023 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-37432501

RESUMO

PURPOSE: To determine the experiences, information, support needs and quality of life of women in the UK living with metastatic breast cancer (MBC) to provide content for educational materials. METHODS: An online survey, hosted for 3 months on a UK MBC charity website, comprised sections covering issues such as communication about MBC treatment and management, helpful and less helpful things that healthcare professionals, family and friends did or said and completion of the Patient Roles and Responsibilities Scale (PRRS). RESULTS: A total of 143 patients participated; 48/143(33%) presented de novo; 54/143(38%) had been living with MBC > 2 years. PRRS analysis revealed that MBC imposed a serious impact upon most respondents' own caring abilities and social lives. A majority 98/139 (71%) wished they had known more about MBC before their diagnosis; 63/134(47%) indicated that they still did not fully understand their illness; merely 78/139(56%) had access to a specialist nurse and only 69/135(51%) had been offered any additional support. Respondents reported little consideration given to their lifestyle/culture during consultations and inconsistent information, support services, continuity of care or access to clinical trials. They commented upon things health care professionals/friends and family did or said that were useful and cited other behaviours that were especially unhelpful. CONCLUSIONS: MBC exerted a deleterious impact upon patients' activities of daily living which were exacerbated in part by significant gaps in support, communication and information. IMPLICATIONS FOR CANCER SURVIVORS: LIMBER results are informing the content of educational materials currently being developed for patients' formal and informal carers.


Assuntos
Neoplasias da Mama , Síndrome Respiratória e Reprodutiva Suína , Suínos , Animais , Humanos , Feminino , Qualidade de Vida , Atividades Cotidianas , Neoplasias da Mama/terapia , Reino Unido
3.
J Phys Chem A ; 127(10): 2322-2335, 2023 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-36790472

RESUMO

The formation of molecular cocrystals in condensed aerosol particles has been recently proposed as an efficient pathway for generation of complex organics in Titan's atmosphere. It follows that cocrystal precipitation may facilitate the transport of biologically important precursors to the surface to be sequestered in an organic karstic and sand environment. Recent laboratory studies on these planetary minerals have predominantly synthesized cocrystals by the controlled freezing of binary mixtures from the liquid phase, allowing for their structural and spectroscopic characterization. However, these techniques are perhaps not best representative of aerosol nucleation and growth microphysics in planetary atmospheres. Herein, we report the first synthesis of the known 1:1 C6H6:C2H2 cocrystal using vapor deposition methods onto a cryogenically cooled substrate. Subsequent transmission FTIR spectroscopy has confirmed the formation of the empirical C6H6:C2H2 cocrystal structure via the observation of diagnostic infrared spectral features. Predicted by periodic-DFT calculations, altered vibrational profiles depict a changing site symmetry of the C6H6 and C2H2 components after transition to the cocrystal unit cell geometry. The 80 K temperature of the cocrystal phase transition overlaps with the condensation curves obtained for both species in Titan's lower stratosphere, revealing that the cocrystal may act as an important environment for photo- and radio-lytic processes leading to the formation of higher order organics in Titan's atmosphere. Such solid-state astrochemistry can now be pursued in oxygen-free laboratory settings under (ultra)high vacuum using standard surface science setups.

4.
BJA Educ ; 21(11): 426-432, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34707888
6.
Pharmazie ; 74(3): 131-135, 2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30961676

RESUMO

Propranolol is a popular ß adrenergic antagonists that, together with pindolol, binds also to serotoninergic receptors, namely 5-HT1A/B. In this work the rigidification of the propranolol structure by locking its hydroxyl group within a 1,3-dioxolane ring was investigated. Constrained derivatives of propranolol were synthesized, fully characterized and tested for their affinity at ß-adrenoreceptors and 5-HT1A/B/C receptors using radioligand binding assay. The constrained derivatives were inactive, as expected, at ß1/2/3 adrenergic receptors. Although less expected, these derivatives failed to bind also to 5-HT1A/B/C receptors. The rigidification of propranolol is detrimental for 5-HT1AR activity.


Assuntos
Antagonistas Adrenérgicos beta/química , Antagonistas Adrenérgicos beta/farmacologia , Propranolol/análogos & derivados , Propranolol/farmacologia , Antagonistas do Receptor 5-HT1 de Serotonina/química , Antagonistas do Receptor 5-HT1 de Serotonina/farmacologia , Antagonistas Adrenérgicos beta/síntese química , Linhagem Celular , Dioxolanos/química , Humanos , Propranolol/síntese química , Propranolol/química , Antagonistas do Receptor 5-HT1 de Serotonina/síntese química , Relação Estrutura-Atividade
7.
Nat Electron ; 2(10)2019.
Artigo em Inglês | MEDLINE | ID: mdl-32118196

RESUMO

A number of current approaches to quantum and neuromorphic computing use superconductors as the basis of their platform or as a measurement component, and will need to operate at cryogenic temperatures. Semiconductor systems are typically proposed as a top-level control in these architectures, with low-temperature passive components and intermediary superconducting electronics acting as the direct interface to the lowest-temperature stages. The architectures, therefore, require a low-power superconductor-semiconductor interface, which is not currently available. Here we report a superconducting switch that is capable of translating low-voltage superconducting inputs directly into semiconductor-compatible (above 1,000 mV) outputs at kelvin-scale temperatures (1K or 4 K). To illustrate the capabilities in interfacing superconductors and semiconductors, we use it to drive a light-emitting diode (LED) in a photonic integrated circuit, generating photons at 1K from a low-voltage input and detecting them with an on-chip superconducting single-photon detector. We also characterize our device's timing response (less than 300 ps turn-on, 15 ns turn-off), output impedance (greater than 1MΩ), and energy requirements (0.18fJ/µm2,3.24mV/nW).

8.
Vet Parasitol ; 243: 226-234, 2017 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-28807298

RESUMO

Haemaphysalis longicornis is the only species of tick present in New Zealand which infests livestock and is also the only competent vector for Theileria orientalis. Since 2012, New Zealand has suffered from an epidemic of infectious bovine anaemia associated with T. orientalis, an obligate intracellular protozoan parasite of cattle and buffaloes. The aim of this study was to predict the spatial distribution of habitat suitability of New Zealand for the tick H. longicornis using a simple rule-based climate envelope model, to validate the model against published data and use the validated model to project an expansion in habitat suitability for H. longicornis under two alternative climate change scenarios for the periods 2046-2065 and 2081-2100, relative to the climate of 1981-2010. A rule-based climate envelope model was developed based on the environmental requirements for off-host tick survival. The resulting model was validated against a maximum entropy environmental niche model of environmental suitability for T. orientalis transmission and against a H. longicornis occurrence map. Validation was completed using the I-similarity statistic and by linear regression. The H. longicornis climate envelope model predicted that 75% of cattle farms in the North Island, 3% of cattle farms in the South Island and 54% of cattle farms in New Zealand overall have habitats potentially suitable for the establishment of H. longicornis. The validation methods showed an acceptable level of agreement between the envelope model and published data. Both of the climate change scenarios, for each of the time periods, projected only slight to moderate increases in the average farm habitat suitability scores for all the South Island regions. However, only for the West Coast, Marlborough, Tasman, and Nelson regions did these increases in environmental suitability translate into an increased proportion of cattle farms with low or high H. longicornis habitat suitability. These results will have important implications for the geographical progression of Theileria-associated bovine anaemia (TABA) in New Zealand and will also be of interest to Haemaphysalis longicornis researchers in Australia, Japan, Korea and New Zealand.


Assuntos
Distribuição Animal , Mudança Climática , Ecossistema , Ixodidae/fisiologia , Modelos Biológicos , Animais , Previsões , Nova Zelândia
9.
Appl Opt ; 54(11): 3218-24, 2015 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-25967306

RESUMO

We demonstrate for the first time, to the best of our knowledge, that a Sagnac interferometer can threshold the energies of pulses. Pulses below a given threshold T are suppressed, while those above this threshold are normalized. The device contains an in-loop tunable isolator and 10.4 m of a highly doped silica fiber. We derive an analytical model of the nonlinear optical loop mirror's pulse energy transfer function and show that its energy transfer function approximates a step function for very high phase shifts (>π). We reveal some limitations of this approach, showing that a step-function transfer function necessarily results in pulse distortion in fast, nonresonant all-optical devices.

10.
Vet Parasitol ; 193(1-3): 8-14, 2013 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-23332122

RESUMO

The development of sensitive PCR-based species-specific diagnostics and parasite genotyping methods offer the opportunity to provide important and detailed information on the infection dynamics of tick-borne disease. In this study we have exploited such tools to investigate the infection kinetics and parasite diversity within Theileria parva in a single farm in Uganda. Initial analysis of a sample of cattle showed high levels of infection with three Theileria species and Ehrlichia bovis, with most animals being infected with more than one pathogen. To study the infection dynamics, newborn calves were sampled longitudinally and it was shown that all animals became infected with T. parva, T. mutans, T. velifera and E. bovis with the average time to first infection being 53, 74, 116 and 109 days, respectively. However, the majority of these calves cleared the infections with T. parva and E. bovis but remained infected with the other two species of Theileria. In order to investigate the diversity of infecting genotypes of T. parva, samples from six calves were genotyped with a single mini-satellite marker at time points over a nine-month period. Each animal was infected with multiple different sets of genotypes and these were lost over different periods of time, implying that immunity is induced against particular infecting strains. To undertake a higher resolution analysis of parasite genotypes, samples from 30 calves were genotyped with a full panel of 12 micro- and mini-satellite markers but, due to the presence of mixed infections, only 16 samples could be used to generate parasite multi-locus genotypes (MLGs). A high degree of diversity of T. parva was seen on the farm, although some MLGs occurred more than once. Similarity analysis demonstrated a level of sub-structuring and the T. parva population was found to be in linkage disequilibrium. The basis for this high diversity coupled with apparent sub-structuring is discussed in relation to the possible causes.


Assuntos
Theileria parva/genética , Theileriose/parasitologia , Animais , Animais Recém-Nascidos , Bovinos , Variação Genética , Genótipo , Filogenia , Theileriose/epidemiologia , Uganda/epidemiologia
12.
Mol Pharm ; 9(4): 874-82, 2012 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-22380593

RESUMO

Advancements toward an improved vaccine against Bacillus anthracis, the causative agent of anthrax, have focused on formulations composed of the protective antigen (PA) adsorbed to aluminum hydroxide. However, due to the labile nature of PA, antigen stability is a primary concern for vaccine development. Thus, there is a need for a delivery system capable of preserving the immunogenicity of PA through all the steps of vaccine fabrication, storage, and administration. In this work, we demonstrate that biodegradable amphiphilic polyanhydride nanoparticles, which have previously been shown to provide controlled antigen delivery, antigen stability, immune modulation, and protection in a single dose against a pathogenic challenge, can stabilize and release functional PA. These nanoparticles demonstrated polymer hydrophobicity-dependent preservation of the biological function of PA upon encapsulation, storage (over extended times and elevated temperatures), and release. Specifically, fabrication of amphiphilic polyanhydride nanoparticles composed of 1,6-bis(p-carboxyphenoxy)hexane and 1,8-bis(p-carboxyphenoxy)-3,6-dioxaoctane best preserved PA functionality. These studies demonstrate the versatility and superiority of amphiphilic nanoparticles as vaccine delivery vehicles suitable for long-term storage.


Assuntos
Antígenos de Bactérias/química , Bacillus anthracis/imunologia , Nanopartículas/química , Polianidridos/química , Estabilidade Proteica
13.
Biotechnol Bioeng ; 109(4): 971-82, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22124969

RESUMO

The characterization of host cell protein (HCP) content during the production of therapeutic recombinant proteins is an important aspect in the drug development process. Despite this, key components of the HCP profile and how this changes with processing has not been fully investigated. Here we have investigated the supernatant HCP profile at different times throughout culture of a null and model GS-CHO monoclonal antibody producing mammalian cell line grown in fed-batch mode. Using 2D-PAGE and LC-MS/MS we identify a number of intracellular proteins (e.g., protein disulfide isomerise; elongation factor 2; calreticulin) that show a significant change in abundance relative to the general increase in HCP concentration observed with progression of culture. Those HCPs that showed a significant change in abundance across the culture above the general increase were dependent on the cell line examined. Further, our data suggests that the majority of HCPs in the supernatant of the cell lines investigated here arise through lysis or breakage of cells, associated with loss in viability, and are not present due to the secretion of protein material from within the cell. SELDI-TOF and principal components analysis were also investigated to enable rapid monitoring of changes in the HCP profile. SELDI-TOF analysis showed the same trends in the HCP profile as observed by 2D-PAGE analysis and highlighted biomarkers that could be used for process monitoring. These data further our understanding of the relationship between the HCP profile and cell viability and may ultimately enable a more directed development of purification strategies and the development of cell lines based upon their HCP profile.


Assuntos
Anticorpos Monoclonais/biossíntese , Células CHO/metabolismo , Meios de Cultivo Condicionados/análise , Imunoglobulina G/biossíntese , Proteínas/análise , Proteômica , Animais , Anticorpos Monoclonais/genética , Técnicas de Cultura Celular por Lotes/métodos , Biomarcadores , Reatores Biológicos , Células CHO/citologia , Sobrevivência Celular , Cromatografia Líquida de Alta Pressão , Cricetinae , Cricetulus , Eletroforese em Gel Bidimensional , Glutamato-Amônia Ligase/biossíntese , Glutamato-Amônia Ligase/genética , Imunoglobulina G/genética , Focalização Isoelétrica , Tamanho da Partícula , Proteínas/metabolismo , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes de Fusão/isolamento & purificação , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Fatores de Tempo
15.
Int J Parasitol ; 41(9): 951-7, 2011 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-21683704

RESUMO

Ivermectin (IVM) resistance is an emerging problem for the control of gastrointestinal nematodes of cattle such as Cooperia oncophora and Ostertagia ostertagi. Although there is still a poor understanding of the molecular basis of macrocyclic lactone (ML)-resistance, it is clear that IVM exerts its activity by binding to glutamate-gated chloride (GluCl) channels within the parasite's neuromuscular system. One of the GluCl genes (avr-14) encodes, via alternative splicing, two subunits, AVR-14A and AVR-14B; the latter is suggested to be the main target for IVM. The genomic DNA (gDNA) sequence of avr-14 in C. oncophora contains 21 exons separated by 20 introns and spans approximately 10 kb of gDNA. Intron 13 contains a sequence with high homology to a mammalian mariner transposase. The L256F polymorphism in the avr-14 gene, which was shown to be associated with IVM resistance in a UK isolate of C. oncophora, was not found in the IVM-resistant C. oncophora and O. ostertagi isolates investigated in this study. However, genetic analyses on C. oncophora indicated a loss in allelic diversity of the avr-14 gene in the resistant isolates compared with the susceptible isolate. This suggests that the avr-14 gene, or another genetically linked locus, is under selection in these Belgian C. oncophora isolates. Comparison of the full-length avr-14B coding sequence in the susceptible and resistant C. oncophora isolates did not show any polymorphisms specifically linked to IVM resistance, although a decrease in the number of avr-14B isoforms was observed in the resistant isolates compared with the susceptible one. Measuring the transcription levels of avr-14B in adult male and female C. oncophora and O. ostertagi worms showed significantly lower levels in resistant worms compared with susceptible ones. Whether the down-regulation of this IVM target actually contributes to the resistance mechanism in these worms remains unclear.


Assuntos
Antinematódeos/farmacologia , Doenças dos Bovinos/parasitologia , Resistência a Medicamentos , Proteínas de Helminto/genética , Ivermectina/farmacologia , Ostertagia/genética , Trichostrongyloidea/genética , Tricostrongiloidíase/veterinária , Sequência de Aminoácidos , Animais , Bovinos , Doenças dos Bovinos/tratamento farmacológico , Feminino , Proteínas de Helminto/metabolismo , Masculino , Dados de Sequência Molecular , Ostertagia/efeitos dos fármacos , Ostertagia/metabolismo , Transcrição Gênica/efeitos dos fármacos , Trichostrongyloidea/efeitos dos fármacos , Trichostrongyloidea/metabolismo , Tricostrongiloidíase/tratamento farmacológico , Tricostrongiloidíase/parasitologia
16.
Br J Anaesth ; 106(3): 352-8, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21258074

RESUMO

BACKGROUND: This study evaluated whether an objective tool would provide a more reliable and valid assessment of perioperative risk compared with the ASA-physical status (ASA-PS) in children. METHODS: A system-based risk assessment tool was developed using these categories: Neurological, Airway, Respiratory, Cardiovascular, and Other (NARCO) with a subcomponent grading surgical severity (SS). Anaesthesiologists reviewed the preoperative assessments and assigned NARCO, SS, and ASA-PS scores independently. Perioperative outcomes were recorded by trained observers. Validity and reliability of the tools were evaluated. RESULTS: NARCO correlated with ASA-PS (ρ=0.664; P<0.01) supporting its criterion validity. Inter-rater reliability of the measures was supported (intraclass correlation coefficients 0.71-0.96; κ 0.43-0.87) except for the Airway category. Measures of exact agreement were slightly better for NARCO compared with ASA-PS. NARCO, SS, and ASA-PS scores correlated significantly with perioperative escalation of care, adverse events (AE), hospital length of stay, and admission status. Correlations between NARCO and ASA-PS and outcomes improved when SS was factored into their coding. There were significant, but low, correlations between all measures and mortality. The odds of having escalation of care, AE, and mortality were 5-47 times greater among children with higher risk scores. CONCLUSIONS: Findings suggest that all measures of outcome have acceptable to excellent reliability with a slight improvement in agreement for the NARCO compared with the ASA-PS. This study supports the validity of both the NARCO and the ASA-PS in predicting perioperative risk in children with a slight improvement in correlations when combined with the SS score.


Assuntos
Indicadores Básicos de Saúde , Cuidados Pré-Operatórios/métodos , Adolescente , Criança , Pré-Escolar , Humanos , Lactente , Recém-Nascido , Complicações Intraoperatórias , Assistência Perioperatória/métodos , Complicações Pós-Operatórias , Prognóstico , Psicometria , Medição de Risco/métodos
17.
Vet Parasitol ; 175(3-4): 212-9, 2011 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-21074945

RESUMO

Cape buffalo (Syncerus caffer) are considered to be an important reservoir for various tick-borne haemoparasites of veterinary importance. In this study we have compared the haemoparasite carrier prevalence in buffalo from four geographically isolated national parks in Uganda [Lake Mburo National Park (LMNP), Queen Elizabeth National Park (QENP), Murchison Falls National Park (MFNP) and Kidepo Valley National Park (KVNP)]. Differences were seen in haemoparasite prevalence in buffalo from the four national parks. All the buffalo sampled in LMNP were carriers of Theileria parva however, buffalo from MFNP and KVNP, which are both located in the north of Uganda, were negative for T. parva. Interestingly, 95% of buffalo in the northern part of QENP were T. parva positive, however all buffalo sampled in the south of the park were negative. A high multiplicity of infection was recorded in all the buffalo found to be carrying T. parva, with evidence of at least nine parasite genotypes in some animals. Most of the buffalo sampled in all four national parks were carriers of T. mutans and T. velifera, however none were carriers of T. taurotragi, Babesia bovis, Babesia bigemina, Ehrlichia bovis or Ehrlichia ruminantium. All the buffalo sampled from LMNP were positive for T. buffeli and T. sp. (buffalo) however, buffalo from the parks in the north of the country (KVNP and MFNP) were negative for these haemoparasites. Anaplasma centrale and Anaplasma marginale were circulating in buffalo from all four national parks. T. parva gene pools from two geographically separated populations of buffalo in two of the national parks in Uganda (LMNP and QENP) were compared. The T. parva populations in the two national parks were distinct, indicating that there was limited gene flow between the populations. The results presented highlight the complexity of tick-borne pathogen infections in buffalo and the significant role that buffalo may play as reservoir hosts for veterinary haemoparasites that have the potential to cause severe disease in domestic cattle.


Assuntos
Biodiversidade , Búfalos/parasitologia , Portador Sadio/veterinária , Theileria parva/genética , Theileriose/epidemiologia , Animais , Portador Sadio/epidemiologia , Portador Sadio/parasitologia , Bovinos , Reservatórios de Doenças/parasitologia , Reservatórios de Doenças/veterinária , Repetições Minissatélites/genética , Hibridização de Ácido Nucleico , Reação em Cadeia da Polimerase , Prevalência , Sensibilidade e Especificidade , Theileriose/parasitologia , Doenças Transmitidas por Carrapatos/epidemiologia , Doenças Transmitidas por Carrapatos/parasitologia , Doenças Transmitidas por Carrapatos/veterinária , Uganda/epidemiologia
19.
Biotechnol Bioeng ; 107(1): 85-95, 2010 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-20506289

RESUMO

With the trend towards the generation and production of increasing numbers of complex biopharmaceutical (protein based) products, there is an increased need and requirement to characterize both the product and production process in terms of robustness and reproducibility. This is of particular importance for products from mammalian cell culture which have large molecular structures and more often than not complex post-translational modifications (PTMs) that can impact the efficacy, stability and ultimately the safety of the final product. It is therefore vital to understand how the operating conditions of a bioprocess affect the distribution and make up of these PTMs to ensure a consistent quality and activity in the final product. Here we have characterized a typical bioprocess and determined (a) how the time of harvest from a mammalian cell culture and, (b) through the use of an ultra scale-down mimic how the nature of the primary recovery stages, affect the distribution and make up of the PTMs observed on a recombinant IgG(4) monoclonal antibody. In particular we describe the use of rapid whole antibody analysis by mass spectrometry to analyze simultaneously the changes that occur to the cleavage of heavy chain C-terminal lysine residues and the glycosylation pattern, as well as the presence of HL dimers. The time of harvest was found to have a large impact upon the range of glycosylation patterns observed, but not upon C-terminal lysine cleavage. The culture age had a profound impact on the ratio of different glycan moieties found on antibody molecules. The proportion of short glycans increased (e.g., (G0F)(2) 20-35%), with an associated decrease in the proportion of long glycans with culture age (e.g., (G2F)(2) 7-4%, and G1F/G2F from 15.2% to 7.8%). Ultra scale-down mimics showed that subsequent processing of these cultures did not change the post-translational modifications investigated, but did increase the proportion of half antibodies present in the process stream. The combination of ultra scale-down methodology and whole antibody analysis by mass spectrometry has demonstrated that the effects of processing on the detailed molecular structure of a monoclonal antibody can be rapidly determined early in the development process. In this study we have demonstrated this analysis to be applicable to critical process design decisions (e.g., time of harvest) in terms of achieving a desired molecular structure, but this approach could also be applied as a selection criterion as to the suitability of a platform process for the preparation of a new drug candidate. Also the methodology provides means for bioprocess engineers to predict at the discovery phase how a bioprocess will impact upon the quality of the final product.


Assuntos
Anticorpos Monoclonais/análise , Centrifugação/métodos , Espectrometria de Massas/métodos , Mapeamento de Peptídeos/métodos , Processamento de Proteína Pós-Traducional , Proteínas Recombinantes/análise , Animais , Células CHO , Cricetinae , Cricetulus
20.
Eukaryot Cell ; 9(2): 336-43, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19966032

RESUMO

The P2 aminopurine transporter, encoded by TbAT1 in African trypanosomes in the Trypanosoma brucei group, carries melaminophenyl arsenical and diamidine drugs into these parasites. Loss of this transporter contributes to drug resistance. We identified the genomic location of TbAT1 to be in the subtelomeric region of chromosome 5 and determined the status of the TbAT1 gene in two trypanosome lines selected for resistance to the melaminophenyl arsenical, melarsamine hydrochloride (Cymelarsan), and in a Trypanosoma equiperdum clone selected for resistance to the diamidine, diminazene aceturate. In the Trypanosoma brucei gambiense STIB 386 melarsamine hydrochloride-resistant line, TbAT1 is deleted, while in the Trypanosoma brucei brucei STIB 247 melarsamine hydrochloride-resistant and T. equiperdum diminazene-resistant lines, TbAT1 is present, but expression at the RNA level is no longer detectable. Further characterization of TbAT1 in T. equiperdum revealed that a loss of heterozygosity at the TbAT1 locus accompanied loss of expression and that P2-mediated uptake of [(3)H]diminazene is lost in drug-resistant T. equiperdum. Adenine-inhibitable adenosine uptake is still detectable in a DeltaTbat1 T. b. brucei mutant, although at a greatly reduced capacity compared to that of the wild type, indicating that an additional adenine-inhibitable adenosine permease, distinct from P2, is present in these cells.


Assuntos
Proteínas de Membrana Transportadoras/genética , Proteínas de Protozoários/genética , Tripanossomicidas/farmacologia , Trypanosoma brucei brucei/efeitos dos fármacos , Regiões 3' não Traduzidas , DNA de Protozoário/metabolismo , Diminazena/análogos & derivados , Diminazena/farmacologia , Resistência a Medicamentos/genética , Proteínas de Membrana Transportadoras/metabolismo , Fases de Leitura Aberta , Proteínas de Protozoários/metabolismo , Trypanosoma brucei brucei/genética , Trypanosoma brucei brucei/metabolismo
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