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1.
Nutr Health ; 27(2): 273-281, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33331231

RESUMO

BACKGROUND: We report the design, protocol and statistical analysis plan for the Arkansas Active Kids (AAK) Study. The study investigates the complex relationships between factors that contribute to metabolic health and obesity status in prepubertal school-age children in the state of Arkansas. AIM: We aim to identify modifiable behavioral and environmental factors and phenotypes related to metabolic health that are associated with obesity status that, if addressed effectively, can aid in designing effective intervention strategies to improve fitness and reduce obesity in children. METHODS: We analyzed dietary and physical activity data from two national surveys (National Survey of Children's Health and Youth Risk Behavior Surveillance System). We then conducted detailed surveys to collect dietary, physical activity, socio-demographic, and environmental data from a sample of 226 prepubertal Arkansas children. In the same sample of prepubertal children, we also collected extensive physiologic data to further study associations between physical activity and metabolic health. RESULTS: All study visits included detailed measures of vital signs, energy expenditure, components of physical fitness, body composition and the collection of biological samples for determination of metabolic analytes. CONCLUSION: The observational, environmental and physiological results will be used to craft multivariate statistical models to identify which variables define 'phenotype signatures' that associate with fitness level and obesity status.


Assuntos
Obesidade Infantil , Adolescente , Arkansas , Criança , Exercício Físico , Humanos , Obesidade Infantil/epidemiologia , Obesidade Infantil/prevenção & controle , Aptidão Física , Instituições Acadêmicas
2.
J Neurosci ; 39(36): 7049-7060, 2019 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-31217331

RESUMO

It is a daily challenge for our brains to establish new memories via learning while providing stable storage of remote memories. In the adult vertebrate brain, bimodal regulation of the extracellular matrix (ECM) may regulate the delicate balance of learning-dependent plasticity and stable memory formation. Here, we trained adult male mice in a cortex-dependent auditory discrimination task and measured the abundance of ECM proteins brevican (BCN) and tenascin-R over the course of acquisition learning, consolidation, and long-term recall in two learning-relevant brain regions; the auditory cortex and hippocampus. Although early training led to a general downregulation of total ECM proteins, successful retrieval correlated with a region-specific and transient upregulation of BCN levels in the auditory cortex. No other parameter such as arousal or stress could account for the transient and region-specific BCN upregulation. This performance-dependent biphasic regulation of the ECM may assist transient plasticity to facilitate initial learning and subsequently promote the long-term consolidation of memory.SIGNIFICANCE STATEMENT The capacity to learn throughout life and at the same time guarantee lifelong storage and remote recall of established memories is a daily challenge. Emerging evidence suggests an important function of the extracellular matrix (ECM), a conglomerate of secreted proteins and polysaccharides in the adult vertebrate brain. We trained mice in an auditory long-term memory task and measured learning-related dynamic changes of the ECM protein brevican. Specifically, in the auditory cortex brevican is downregulated during initial learning and subsequently upregulated in exclusively those animals that have learned the task, suggesting a performance-dependent regulation in the service of memory consolidation and storage. Our data may provide novel therapeutic implications for several neuropsychiatric diseases involving dysregulation of the ECM.


Assuntos
Córtex Auditivo/metabolismo , Brevicam/genética , Consolidação da Memória , Animais , Córtex Auditivo/fisiologia , Percepção Auditiva , Brevicam/metabolismo , Discriminação Psicológica , Hipocampo/metabolismo , Hipocampo/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Regulação para Cima
3.
Nat Methods ; 13(8): 639-50, 2016 07 28.
Artigo em Inglês | MEDLINE | ID: mdl-27467727

RESUMO

Photoacoustic imaging (PAI) is an emerging tool that bridges the traditional depth limits of ballistic optical imaging and the resolution limits of diffuse optical imaging. Using the acoustic waves generated in response to the absorption of pulsed laser light, it provides noninvasive images of absorbed optical energy density at depths of several centimeters with a resolution of ∼100 µm. This versatile and scalable imaging modality has now shown potential for molecular imaging, which enables visualization of biological processes with systemically introduced contrast agents. Understanding the relative merits of the vast range of contrast agents available, from small-molecule dyes to gold and carbon nanostructures to liposome encapsulations, is a considerable challenge. Here we critically review the physical, chemical and biochemical characteristics of the existing photoacoustic contrast agents, highlighting key applications and present challenges for molecular PAI.


Assuntos
Meios de Contraste/química , Diagnóstico por Imagem/métodos , Técnicas Fotoacústicas/métodos , Imagem Corporal Total/métodos , Animais , Humanos , Nanopartículas/química
4.
BMC Vet Res ; 15(1): 344, 2019 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-31619238

RESUMO

BACKGROUND: African animal trypanosomosis remains the major constraint of livestock production and livelihood of pastoral communities in Cameroon. Despite several decades of vector and parasite control efforts, it has not been eradicated. Alternative and sustainable control strategies require a sound knowledge of the local species, strains and vectors. In the Sudano-Sahelian and Guinea Savannah of Cameroon the prevalence and genetic diversity of trypanosomes infecting cattle was investigated by microscopy of cattle blood buffy coat and molecular methods using generic primers targeting parts of the internal transcribed spacer 1 (ITS-1) and encoded glycosomal glyceraldehyde 3-phosphate dehydrogenase-gene (gGAPDH). RESULTS: A total of 1176 randomly chosen cattle from five divisions in the Sudano-Sahelian and Guinea Savannah of Cameroon were examined. The overall prevalence of trypanosomes by microscopy was 5.9% (56/953) in contrast to 53.2% (626/1176) when molecular tools were used. This indicated a limited sensitivity of microscopy in subclinical infections with frequently low parasitemia. Three trypanosome species were identified by light microscopy: T. vivax (2.3%), T. brucei (3.7%) and T. congolense (3.0%), whereas five were identified by PCR, namely T. grayi/T. theileri (30.8%), T. vivax (17.7%), T. brucei (14.5%) and T. congolense (5.1%). Unexpected cases of T. grayi (n = 4) and T. theileri (n = 26) were confirmed by sequencing. Phylogenetic analysis of the gGAPDH revealed the presence of T. vivax, clade A and T. vivax clade C, which were co-endemic in the Faro et Deo division. T. grayi/T. theileri were the predominant species infecting cattle in tsetse free areas. In contrast, T. vivax, T. brucei and T. congolense were more abundant in areas where the Glossina-vectors were present. CONCLUSIONS: The abundance of pathogenic trypanosomes in tsetse infested areas is alarming and even more, the occurrence of T. vivax, T. brucei, T. congolense, T. theileri and T. grayi in tsetse-free areas implies that tsetse control alone is not sufficient to control trypanosomosis in livestock. To implement control measures that reduce the risk of spread in tsetse free areas, close monitoring using molecular tools and a thorough search for alternative vectors of trypanosomes is recommended.


Assuntos
Doenças dos Bovinos/epidemiologia , Trypanosoma/isolamento & purificação , Tripanossomíase Africana/epidemiologia , Animais , Buffy Coat/parasitologia , Camarões/epidemiologia , Bovinos , Doenças dos Bovinos/parasitologia , Feminino , Genes de Protozoários , Insetos Vetores , Masculino , Prevalência , Trypanosoma/classificação , Trypanosoma/genética , Tripanossomíase Africana/parasitologia , Tripanossomíase Africana/prevenção & controle , Moscas Tsé-Tsé
5.
BMC Microbiol ; 18(Suppl 1): 180, 2018 11 23.
Artigo em Inglês | MEDLINE | ID: mdl-30470197

RESUMO

BACKGROUND: Tsetse flies are vectors of trypanosomes, parasites that cause devastating disease in humans and livestock. In the course of vector control programmes it is necessary to know about the Glossina species present in the study area, the population dynamics and the genetic exchange between tsetse fly populations. RESULTS: To achieve an overview of the tsetse fly diversity in Nigeria and at the Nigeria-Cameroon border, tsetse flies were trapped and collected between February and March 2014 and December 2016. Species diversity was determined morphologically and by analysis of Cytochrome C Oxidase SU1 (COI) gene sequences. Internal transcribed spacer-1 (ITS-1) sequences were compared to analyse variations within populations. The most dominant species were G. m. submorsitans, G. tachinoides and G. p. palpalis. In Yankari Game Reserve and Kainji Lake National Park, G. submorsitans and G. tachinoides were most frequent, whereas in Old Oyo National Park and Ijah Gwari G. p. palpalis was the dominant species. Interestingly, four unidentified species were recorded during the survey, for which no information on COI or ITS-1 sequences exists. G. p. palpalis populations showed a segregation in two clusters along the Cameroon-Nigerian border. CONCLUSIONS: The improved understanding of the tsetse populations in Nigeria will support decisions on the scale in which vector control is likely to be more effective. In order to understand in more detail how isolated these populations are, it is recommended that further studies on gene flow be carried out using other markers, including microsatellites.


Assuntos
Variação Genética , Filogenia , Moscas Tsé-Tsé/classificação , Moscas Tsé-Tsé/genética , Animais , Camarões , DNA Intergênico/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Feminino , Controle de Insetos , Insetos Vetores/classificação , Insetos Vetores/parasitologia , Masculino , Repetições de Microssatélites , Nigéria , Dinâmica Populacional
6.
Am J Trop Med Hyg ; 110(6): 1127-1136, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38697074

RESUMO

Animal African trypanosomiasis, also known as nagana, is caused by Trypanosoma species, which cause significant clinical diseases and lead to losses in animal production. We carried out a cross-sectional survey to investigate the composition of vectors and parasite diversity in two districts in the eastern region of Ghana where pigs and cattle were exposed to tsetse bites. We performed cytochrome c oxidase subunit 1 polymerase chain reaction (PCR) to identify tsetse species and internal transcribed spacer 1 PCR to identify Trypanosoma species. Also, we investigated the source of tsetse blood meal based on mitochondrial cytochrome b gene sequence analysis. A total of 229 tsetse, 65 pigs, and 20 cattle were investigated for trypanosomes. An overall vector density of 4.3 tsetse/trap/day was observed. A trypanosome prevalence of 58.9% (95% CI = 52.5-65.1%), 46.2% (95% CI = 34.6-58.1%), and 0.0% (95% CI = 0.0-16.1%) in tsetse, pigs, and cattle, respectively, was detected. Trypanosoma congolense was predominant, with a prevalence of 33.3% (95% CI = 73.3-86.5%) in tsetse. There was evidence of multiple infections in tsetse and pigs. Approximately 39% of the tsetse were positive for multiple infections of T. congolense and Trypanosoma simiae. Parasite prevalence in pigs across the communities was high, with significant differences associated between locations (χ2 = 28.06, 95% CI = 0.05-0.81, P = 0.0009). Tsetse blood meal analysis revealed feeding on domestic Sus scrofa domesticus (pigs) and Phacochoerus africanus (warthogs). Infective tsetse may transmit trypanosomes to livestock and humans in the communities studied.


Assuntos
Trypanosoma , Tripanossomíase Africana , Moscas Tsé-Tsé , Animais , Gana/epidemiologia , Moscas Tsé-Tsé/parasitologia , Bovinos , Tripanossomíase Africana/transmissão , Tripanossomíase Africana/epidemiologia , Tripanossomíase Africana/veterinária , Suínos , Trypanosoma/isolamento & purificação , Trypanosoma/genética , Trypanosoma/classificação , Estudos Transversais , Doenças dos Suínos/transmissão , Doenças dos Suínos/epidemiologia , Doenças dos Suínos/parasitologia , Insetos Vetores/parasitologia , Florestas , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/transmissão , Doenças dos Bovinos/parasitologia , Prevalência , Feminino
7.
Commun Biol ; 7(1): 563, 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38740899

RESUMO

Targeting the estrogen receptor alpha (ERα) pathway is validated in the clinic as an effective means to treat ER+ breast cancers. Here we present the development of a VHL-targeting and orally bioavailable proteolysis-targeting chimera (PROTAC) degrader of ERα. In vitro studies with this PROTAC demonstrate excellent ERα degradation and ER antagonism in ER+ breast cancer cell lines. However, upon dosing the compound in vivo we observe an in vitro-in vivo disconnect. ERα degradation is lower in vivo than expected based on the in vitro data. Investigation into potential causes for the reduced maximal degradation reveals that metabolic instability of the PROTAC linker generates metabolites that compete for binding to ERα with the full PROTAC, limiting degradation. This observation highlights the requirement for metabolically stable PROTACs to ensure maximal efficacy and thus optimisation of the linker should be a key consideration when designing PROTACs.


Assuntos
Receptor alfa de Estrogênio , Proteólise , Proteína Supressora de Tumor Von Hippel-Lindau , Humanos , Receptor alfa de Estrogênio/metabolismo , Proteína Supressora de Tumor Von Hippel-Lindau/metabolismo , Proteína Supressora de Tumor Von Hippel-Lindau/genética , Feminino , Proteólise/efeitos dos fármacos , Animais , Administração Oral , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Camundongos , Antineoplásicos/farmacologia , Antineoplásicos/administração & dosagem
8.
Front Mol Biosci ; 10: 1136975, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37033448

RESUMO

Purpose: To evaluate the association of platelet (PL) mitochondria respiration with markers of cardiovascular health in children ages 7-10 years. Methods: PL mitochondrial respiration (n = 91) was assessed by high resolution respirometry (HRR): Routine (R) respiration, complex (C) I linked respiration (CI), and maximal uncoupled electron transport capacity of CII (CIIE) were measured. The respiratory control ratio (RCR) was calculated as the ratio of maximal oxidative phosphorylation capacity of CI and CI leak respiration (PCI/LCI). Peak V ˙ O2 (incremental bike test) and body composition (dual-energy X-ray absorptiometry) were measured. Multiple generalized linear regression analysis was used to model the association of measures by HRR with variables of interest: adiposity, low-density lipoprotein (LDL-C) and triglyceride (TG) status (normal vs. elevated) HOMA2-IR, blood pressure status (normal vs. high), and demographics. Results: R and CI-linked respiration positively associated with adiposity, high blood pressure (HBP), and peak V ˙ O2. R and CI-linked respiration had inverse association with age and elevated LDL-C. CIIE was higher in children with elevated LDL-C (log-ß = -0.54, p = 0.010). HBP and peak V ˙ O2 interacted in relation to RCR (log-ß = -0.01, p = 0.028). Specifically, RCR was lowest among children with HBP and low aerobic capacity (i.e., mean peak V ˙ O2 -1SD). HOMA2-IR did not associate with measures of PL mitochondria respiration. Conclusion: In PL, R and CI-linked mitochondrial respiration directly associate with adiposity, peak V ˙ O2 and HBP. Elevated LDL-C associates with lower CI-linked respiration which is compensated by increasing CII respiration. PL bioenergetics phenotypes in children associate with whole-body metabolic health status.

9.
Sci Rep ; 13(1): 10031, 2023 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-37340068

RESUMO

The quantification of the number of targets in biological systems is an important parameter to assess the suitability of surface markers as targets for drugs, drug delivery and medical imaging. Likewise, quantifying the interaction with the target in terms of affinity and binding kinetics is essential during drug development. Commonly used approaches to quantify membrane antigens on live cells are based on manual saturation techniques that are labour-intensive, require careful calibration of the generated signal and do not quantify the binding rates. Here, we present how measuring interactions in real-time on live cells and tissue under ligand depletion conditions can be used to simultaneously quantify the kinetic binding parameters as well as the number of available binding sites in a biological system. Suitable assay design was explored with simulated data and feasibility of the method verified with experimental data for exemplary low molecular weight peptide and antibody radiotracers as well as fluorescent antibodies. In addition to revealing the number of accessible target sites and improving the accuracy of binding kinetics and affinities, the presented method does not require knowledge about the absolute signal generated per ligand molecule. This enables a simplified workflow for use with both radioligands and fluorescent binders.


Assuntos
Anticorpos , Antígenos , Ligantes , Ligação Proteica , Sítios de Ligação , Cinética
10.
Res Sq ; 2023 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-37214831

RESUMO

Background Tsetse flies are cyclical vectors of African trypanosomiasis. They have established symbiotic associations with different bacteria, which influence certain aspects of their physiology. The vector competence of tsetse flies for different trypanosome species is highly variable and is suggested to be affected by various factors, amongst which are bacterial endosymbionts. Symbiotic interactions may provide an avenue for the disease control. The current study provided the prevalence of 3 tsetse symbionts in Glossina species from Cameroon, Chad and Nigeria. Results Tsetse flies were collected from five different locations and dissected. DNA was extracted and polymerase chain reaction PCR was used to detect the presence of Sodalis glossinidius , Spiroplasma sp and Wolbachia using specific primers. A total of 848 tsetse samples were analysed: Glossina morsitans submorsitans (47.52%), Glossina palpalis palpalis (37.26%), Glossina fuscipes fuscipes (9.08%) and Glossina tachinoides (6.13%). Only 95 (11.20%) were infected with at least one of the 3 symbionts. Among the infected, 6 (6.31%) were carrying mixed infection ( Wolbachia and Spiroplasma ). The overall symbiont prevalence was 0.88%, 3.66% and 11.00% respectively, for Sodalis , Spiroplasma and Wolbachia . Prevalence varied between countries and tsetse species. No Spiroplasma was detected in samples from Cameroon and no Sodalis was found in samples from Nigeria. Conclusion The present study revealed for the first time, the presence of infection by Spiroplasma in tsetse in Chad and Nigeria. These findings provide useful information to the repertoire of bacterial flora of tsetse flies and incite to more investigations to understand their implication in the vector competence of tsetse flies.

11.
JAMA ; 306(3): 287-93, 2011 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-21771989

RESUMO

CONTEXT: National recommendations for the prevention and treatment of obesity emphasize reducing energy intake. Foods purchased in restaurants provide approximately 35% of the daily energy intake in US individuals but the accuracy of the energy contents listed for these foods is unknown. OBJECTIVE: To examine the accuracy of stated energy contents of foods purchased in restaurants. DESIGN AND SETTING: A validated bomb calorimetry technique was used to measure dietary energy in food from 42 restaurants, comprising 269 total food items and 242 unique foods. The restaurants and foods were randomly selected from quick-serve and sit-down restaurants in Massachusetts, Arkansas, and Indiana between January and June 2010. MAIN OUTCOME MEASURE: The difference between restaurant-stated and laboratory-measured energy contents, which were corrected for standard metabolizable energy conversion factors. RESULTS: The absolute stated energy contents were not significantly different from the absolute measured energy contents overall (difference of 10 kcal/portion; 95% confidence interval [CI], -15 to 34 kcal/portion; P = .52); however, the stated energy contents of individual foods were variable relative to the measured energy contents. Of the 269 food items, 50 (19%) contained measured energy contents of at least 100 kcal/portion more than the stated energy contents. Of the 10% of foods with the highest excess energy in the initial sampling, 13 of 17 were available for a second sampling. In the first analysis, these foods contained average measured energy contents of 289 kcal/portion (95% CI, 186 to 392 kcal/portion) more than the stated energy contents; in the second analysis, these foods contained average measured energy contents of 258 kcal/portion (95% CI, 154 to 361 kcal/portion) more than the stated energy contents (P <.001 for each vs 0 kcal/portion difference). In addition, foods with lower stated energy contents contained higher measured energy contents than stated, while foods with higher stated energy contents contained lower measured energy contents (P <.001). CONCLUSIONS: Stated energy contents of restaurant foods were accurate overall. However, there was substantial inaccuracy for some individual foods, with understated energy contents for those with lower energy contents.


Assuntos
Ingestão de Energia , Análise de Alimentos , Rotulagem de Alimentos , Alimentos/estatística & dados numéricos , Legislação sobre Alimentos , Restaurantes/estatística & dados numéricos , Arkansas , Calorimetria , Dieta , Revelação , Humanos , Indiana , Massachusetts , Obesidade/prevenção & controle , Controle de Qualidade , Reprodutibilidade dos Testes
12.
Med Sci Sports Exerc ; 53(11): 2225-2232, 2021 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-34280939

RESUMO

INTRODUCTION: High blood pressure (HBP) in children causes preclinical damage to the heart and accelerates atherosclerosis. Current pharmacological treatments have limited ability to prevent end-organ damage, particularly that of the kidneys. A contrasting element between adult versus pediatric HPB treatment is the emphasis in adults on exercise regimens that target increments in cardiorespiratory fitness (CRF; peak oxygen consumption [V˙O2peak]). The aim of this study was to evaluate the association of CRF with blood pressure percentiles and blood pressure status in children with normal and excessive adiposity (NA vs EA). An exploratory aim was to measure associations of CRF with (a) other cardiovascular disease risk factors commonly found in children with HBP and (b) kidney function. METHODS: Children (n = 211) attended one study visit. CRF was measured using an incremental bike test and body composition by dual-energy x-ray absorptiometry. Fat-free mass (FFM) index was calculated as kilograms of FFM per square meter. Multiple logistic and linear regression analyses were used to model the probability of HBP and other variables of interest (plasma lipids, HOMA2-IR, alanine aminotransferase, and estimated glomerular filtration rate) against V˙O2peak. RESULTS: CRF interacted with adiposity status in predicting the probability of HBP. Each additional milliliter per minute per FFM index in V˙O2peak decreased the odds of HBP by 8% in the EA group only (odds ratio = 0.92, 95% confidence interval = 0.87-0.99). Systolic and diastolic blood pressure percentiles decreased, and estimated glomerular filtration rate increased with increasing CRF in both adiposity-level groups. HOMA2-IR and alanine aminotransferase decreased with increasing CRF in children with EA only. CONCLUSIONS: Higher CRF associated with decreased probability of clinical HBP, lower insulin resistance, and improved liver function in children with EA. Yet blood pressure percentiles and kidney function improved with increasing CRF irrespective of adiposity status.


Assuntos
Adiposidade/fisiologia , Pressão Sanguínea , Aptidão Cardiorrespiratória , Obesidade Infantil/fisiopatologia , Alanina Transaminase/sangue , Criança , Feminino , Taxa de Filtração Glomerular , Homeostase , Humanos , Hipertensão/sangue , Hipertensão/fisiopatologia , Resistência à Insulina , Lipídeos/sangue , Masculino , Consumo de Oxigênio , Obesidade Infantil/sangue
13.
PLoS Negl Trop Dis ; 15(6): e0009323, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34106914

RESUMO

BACKGROUND: African trypanosomes are parasites mainly transmitted by tsetse flies. They cause trypanosomiasis in humans (HAT) and animals (AAT). In Chad, HAT/AAT are endemic. This study investigates the diversity and distribution of trypanosomes in Mandoul, an isolated area where a tsetse control campaign is ongoing, and Maro, an area bordering the Central African Republic (CAR) where the control had not started. METHODS: 717 human and 540 cattle blood samples were collected, and 177 tsetse flies were caught. Trypanosomal DNA was detected using PCR targeting internal transcribed spacer 1 (ITS1) and glycosomal glyceraldehyde-3 phosphate dehydrogenase (gGAPDH), followed by amplicon sequencing. RESULTS: Trypanosomal DNA was identified in 14 human samples, 227 cattle samples, and in tsetse. Besides T. b. gambiense, T. congolense was detected in human in Maro. In Mandoul, DNA from an unknown Trypanosoma sp.-129-H was detected in a human with a history of a cured HAT infection and persisting symptoms. In cattle and tsetse samples from Maro, T. godfreyi and T. grayi were detected besides the known animal pathogens, in addition to T. theileri (in cattle) and T. simiae (in tsetse). Furthermore, in Maro, evidence for additional unknown trypanosomes was obtained in tsetse. In contrast, in the Mandoul area, only T. theileri, T. simiae, and T. vivax DNA was identified in cattle. Genetic diversity was most prominent in T. vivax and T. theileri. CONCLUSION: Tsetse control activities in Mandoul reduced the tsetse population and thus the pathogenic parasites. Nevertheless, T. theileri, T. vivax, and T. simiae are frequent in cattle suggesting transmission by other insect vectors. In contrast, in Maro, transhumance to/from Central African Republic and no tsetse control may have led to the high diversity and frequency of trypanosomes observed including HAT/AAT pathogenic species. Active HAT infections stress the need to enforce monitoring and control campaigns. Additionally, the diverse trypanosome species in humans and cattle indicate the necessity to investigate the infectivity of the unknown trypanosomes regarding their zoonotic potential. Finally, this study should be widened to other trypanosome hosts to capture the whole diversity of circulating trypanosomes.


Assuntos
Doenças dos Bovinos/parasitologia , Trypanosoma/classificação , Tripanossomíase Africana/parasitologia , Zoonoses/parasitologia , Animais , Bovinos , Doenças dos Bovinos/sangue , Doenças dos Bovinos/epidemiologia , Chade/epidemiologia , Humanos , Especificidade da Espécie , Tripanossomíase Africana/sangue , Tripanossomíase Africana/epidemiologia
14.
J Phys Chem Lett ; 11(19): 8406-8416, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32924494

RESUMO

The benzothiazolium salt, Thioflavin T (ThT), has been widely adopted as the "gold-standard" fluorescent reporter of amyloid in vitro. Its properties as a molecular rotor result in a large-scale (∼1000-fold) fluorescence turn-on upon binding to ß-sheets in amyloidogenic proteins. However, the complex photophysics of ThT combined with the intricate and varied nature of the amyloid binding motif means these interactions are poorly understood. To study this important class of fluorophores, we present a detailed photophysical characterization and comparison of a novel library of 12 ThT-inspired fluorescent probes for amyloid protein (PAPs), where both the charge and donor capacity of the heterocyclic and aminobenzene components have been interrogated, respectively. This enables direct photophysical juxtaposition of two structural groups: the neutral "PAP" (class 1) and the charged "mPAP" fluorophores (class 2). We quantify binding and optical properties at both the bulk and single-aggregate levels with some derivatives showing higher aggregate affinity and brightness than ThT. Finally, we demonstrate their abilities to perform super-resolution imaging of α-synuclein fibrils with localization precisions of ∼16 nm. The properties of the derivatives provide new insights into the relationship between chemical structure and function of benzothiazole probes.

15.
Chem Sci ; 11(18): 4578-4583, 2020 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-34122915

RESUMO

Neurodegenerative diseases such as Alzheimer's and Parkinson's are associated with protein misfolding and aggregation. Recent studies suggest that the small, rare and heterogeneous oligomeric species, formed early on in the aggregation process, may be a source of cytotoxicity. Thioflavin T (ThT) is currently the gold-standard fluorescent probe for the study of amyloid proteins and aggregation processes. However, the poor photophysical and binding properties of ThT impairs the study of oligomers. To overcome this challenge, we have designed Thioflavin X, (ThX), a next-generation fluorescent probe which displays superior properties; including a 5-fold increase in brightness and 7-fold increase in binding affinity to amyloidogenic proteins. As an extrinsic dye, this can be used to study unique structural amyloid features both in bulk and on a single-aggregate level. Furthermore, ThX can be used as a super-resolution imaging probe in single-molecule localisation microscopy. Finally, the improved optical properties (extinction coefficient, quantum yield and brightness) of ThX can be used to monitor structural differences in oligomeric species, not observed via traditional ThT imaging.

16.
J Immunother Cancer ; 7(1): 181, 2019 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-31300044

RESUMO

BACKGROUND: High response rates of metastatic melanoma have been reported upon immune checkpoint inhibition by PD-1 blockade alone or in combination with CTLA-4 inhibitors. However, the majority of patients with a primary resistance to anti-PD-1 monotherapy is also refractory to a subsequent combined checkpoint inhibition. In BRAF wildtype patients with a primary resistance to PD-1 inhibitors, therapeutic options are therefore limited and immune-related adverse events (irAE) have to be taken into consideration when discussing a subsequent immunotherapy. CASE PRESENTATION: We report the case of a 68-year-old male patient with metastatic melanoma who experienced an acute renal failure with nephrotic syndrome due to a minimal change disease developing after a single dose of the anti-PD-1 antibody pembrolizumab. A kidney biopsy revealed a podocytopathy without signs of interstitial nephritis. Renal function recovered to almost normal creatinine and total urine protein levels upon treatment with oral steroids and diuretics. Unfortunately, a disease progression (PD, RECIST 1.1) was observed in a CT scan after resolution of the irAE. In a grand round, re-exposure to a PD-1-containing regime was recommended. Consensually, a combined immunotherapy with ipilimumab and nivolumab was initiated. Nephrotoxicity was tolerable during combined immunotherapy and a CT scan of chest and abdomen showed a deep partial remission (RECIST 1.1) after three doses of ipilimumab (3 mg/kg) and nivolumab (1 mg/kg). CONCLUSION: This case illustrates that a fulminant response to combined checkpoint inhibition is possible after progression after anti-PD-1 monotherapy and a severe irAE.


Assuntos
Antineoplásicos Imunológicos/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Melanoma/complicações , Melanoma/tratamento farmacológico , Síndrome Nefrótica/etiologia , Idoso , Antineoplásicos Imunológicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Substituição de Medicamentos , Humanos , Ipilimumab/administração & dosagem , Testes de Função Renal , Masculino , Melanoma/diagnóstico , Terapia de Alvo Molecular/efeitos adversos , Síndrome Nefrótica/diagnóstico , Nivolumabe/administração & dosagem , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Resultado do Tratamento
17.
Cancer Res ; 79(20): 5407-5417, 2019 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-31455691

RESUMO

Reactive oxygen species play an important role in cancer, however, their promiscuous reactivity, low abundance, and short-lived nature limit our ability to study them in real time in living subjects with conventional noninvasive imaging methods. Photoacoustic imaging is an emerging modality for in vivo visualization of molecular processes with deep tissue penetration and high spatiotemporal resolution. Here, we describe the design and synthesis of a targeted, activatable probe for photoacoustic imaging, which is responsive to one of the major and abundant reactive oxygen species, hydrogen peroxide (H2O2). This bifunctional probe, which is also detectable with fluorescence imaging, is composed of a heptamethine carbocyanine dye scaffold for signal generation, a 2-deoxyglucose cancer localization moiety, and a boronic ester functionality that specifically detects and reacts to H2O2. The optical properties of the probe were characterized using absorption, fluorescence, and photoacoustic measurements; upon addition of pathophysiologic H2O2 concentrations, a clear increase in fluorescence and red-shift of the absorption and photoacoustic spectra were observed. Studies performed in vitro showed no significant toxicity and specific uptake of the probe into the cytosol in breast cancer cell lines. Importantly, intravenous injection of the probe led to targeted uptake and accumulation in solid tumors, which enabled noninvasive photoacoustic and fluorescence imaging of H2O2. In conclusion, the reported probe shows promise for the in vivo visualization of hydrogen peroxide. SIGNIFICANCE: This study presents the first activatable and cancer-targeted hydrogen peroxide probe for photoacoustic molecular imaging, paving the way for visualization of hydrogen peroxide at high spatiotemporal resolution in living subjects.Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/79/20/5407/F1.large.jpg.


Assuntos
Adenocarcinoma/química , Adenocarcinoma/diagnóstico por imagem , Corantes Fluorescentes/análise , Peróxido de Hidrogênio/análise , Imagem Óptica/métodos , Técnicas Fotoacústicas/métodos , Piperazinas/análise , Absorção de Radiação , Adenocarcinoma/secundário , Animais , Linhagem Celular Tumoral , Desoxiglucose/farmacocinética , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/farmacocinética , Corantes Fluorescentes/toxicidade , Xenoenxertos , Humanos , Peróxido de Hidrogênio/farmacologia , Neoplasias Hepáticas/química , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/secundário , Células MCF-7 , Camundongos , Camundongos Nus , Imagem Molecular/métodos , Transplante de Neoplasias , Estresse Oxidativo , Piperazinas/síntese química , Piperazinas/farmacocinética , Piperazinas/toxicidade , Distribuição Tecidual
18.
Parasit Vectors ; 12(1): 481, 2019 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-31610794

RESUMO

BACKGROUND: Trypanosomes cause disease in humans and livestock in sub-Saharan Africa and rely on tsetse flies as their main insect vector. Nigeria is the most populous country in Africa; however, only limited information about the occurrence and diversity of trypanosomes circulating in the country is available. METHODS: Tsetse flies were collected from five different locations in or adjacent to protected areas, i.e. national parks and game reserves, in Nigeria. Proboscis and gut samples were analysed for trypanosome DNA by molecular amplification of the internal transcribed spacer 1 (ITS1) region and part of the trypanosome specific glycosomal glyceraldehyde-3-phosphate dehydrogenase (gGAPDH) gene. RESULTS: The most abundant Trypanosoma species found in the tsetse gut was T. grayi, a trypanosome infecting crocodiles. It was ubiquitously distributed throughout the country, accounting for over 90% of all cases involving trypanosomes. Trypanosoma congolense was detected in gut samples from all locations except Cross River National Park, but not in the proboscis, while T. brucei (sensu lato) was not detected at all. In proboscis samples, T. vivax was the most prominent. The sequence diversity of gGAPDH suggests that T. vivax and T. grayi represent genetically diverse species clusters. This implies that they are highly dynamic populations. CONCLUSIONS: The prevalence of animal pathogenic trypanosomes throughout Nigeria emphasises the role of protected areas as reservoirs for livestock trypanosomes. The genetic diversity observed within T. vivax and T. grayi populations might be an indication for changing pathogenicity or host range and the origin and consequences of this diversity has to be further investigated.


Assuntos
Variação Genética , Insetos Vetores/parasitologia , Trypanosoma/genética , Tripanossomíase Africana/parasitologia , Moscas Tsé-Tsé/parasitologia , Animais , DNA Intergênico/química , DNA Intergênico/isolamento & purificação , DNA de Protozoário/isolamento & purificação , Humanos , Insetos Vetores/classificação , Nigéria/epidemiologia , Filogenia , Reação em Cadeia da Polimerase , Prevalência , Especificidade da Espécie , Trypanosoma/classificação , Trypanosoma/isolamento & purificação , Trypanosoma congolense/classificação , Trypanosoma congolense/genética , Trypanosoma congolense/isolamento & purificação , Trypanosoma vivax/classificação , Trypanosoma vivax/genética , Trypanosoma vivax/isolamento & purificação , Tripanossomíase Africana/epidemiologia , Tripanossomíase Africana/transmissão , Moscas Tsé-Tsé/classificação
19.
Paediatr Anaesth ; 18(9): 823-30, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18768042

RESUMO

BACKGROUND: The electroencephalographic Narcotrend Index (NI) may potentially help to titrate sedative medication during diagnostic and therapeutic procedures in children. METHODS: With local ethics committee approval and informed parental consent, 31 patients, aged 8.9 +/- 4.3 years, scheduled for elective upper gastrointestinal endoscopy were enrolled in this prospective, double-blinded observational study. Initially, patients received a single dose of intravenous piritramide 0.1 mg x kg(-1), followed by propofol 2 mg x kg(-1) and, if necessary, additional propofol doses (0.5 mg x kg(-1)) to achieve and maintain a level of deep sedation throughout the procedure. Sedation was assessed by the University of Michigan Sedation Scale (UMSS). We investigated the relationship between depth of sedation, and the NI, and the classical EEG parameters (cEEG), total EEG power (Power), spectral edge (SEF) and median frequency, and relative power in the beta, alpha, theta and delta bands. The performance of the NI and cEEG parameters was evaluated by prediction probability (P(K)), receiver operating characteristic (ROC) and Spearman rank order correlation analysis. RESULTS: Mean P(K) values for NI (0.88) vs UMSS were higher than for the other cEEG parameters, except for Power (0.82) and SEF(0.81). Spearman correlation analysis revealed superiority of the NI over all cEEG parameters. The area under the curve for the NI was 0.93, which was superior to all other EEG parameters beside Power (0.86) and relative power in alpha (0.82). CONCLUSIONS: The results of this study suggest that the NI may be an objective nondisruptive tool for assessment of hypnotic depth in children under propofol-induced procedural sedation.


Assuntos
Analgesia/métodos , Anestésicos Intravenosos/farmacologia , Sedação Consciente/métodos , Eletroencefalografia/métodos , Endoscopia Gastrointestinal , Propofol/farmacologia , Adolescente , Analgesia/instrumentação , Área Sob a Curva , Encéfalo/efeitos dos fármacos , Criança , Pré-Escolar , Estado de Consciência/efeitos dos fármacos , Método Duplo-Cego , Eletroencefalografia/instrumentação , Humanos , Lactente , Monitorização Intraoperatória/métodos , Valor Preditivo dos Testes , Estudos Prospectivos , Padrões de Referência , Projetos de Pesquisa , Resultado do Tratamento
20.
Z Psychosom Med Psychother ; 54(3): 227-40, 2008.
Artigo em Alemão | MEDLINE | ID: mdl-18713536

RESUMO

OBJECTIVE: This study examines the relationship between personality characteristics, depression symptoms, demographic profile, and the amount of the tinnitus-related distress experienced. METHOD: 121 patients suffering from tinnitus were examined by unique testing in a tinnitus-practice via three questionnaires over a period of 22 months. RESULTS: A relationship between the severity of tinnitus-related distress and demographic profile as well as a relationship between depression symptoms and the severity of the tinnitus-related distress could be shown. Also, significant results were observed within the personality range in the areas of "impulsiveness," "aggressiveness," "demands," "physical discomfort," "health worries," und "emotionality." DISCUSSION: Patients suffering severely from tinnitus represent a clinically relevant group for psychotherapeutic treatment. Especially persons with comorbid symptoms of depression should be screened regularly and offered additional psychotherapeutic or psychiatric treatment.


Assuntos
Transtorno Depressivo/diagnóstico , Transtornos da Personalidade/diagnóstico , Transtornos Psicofisiológicos/psicologia , Zumbido/psicologia , Adaptação Psicológica , Adulto , Idoso , Comorbidade , Transtorno Depressivo/psicologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Transtornos da Personalidade/psicologia , Inventário de Personalidade , Psicoterapia , Qualidade de Vida/psicologia , Encaminhamento e Consulta , Papel do Doente
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