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1.
Commun Biol ; 7(1): 563, 2024 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-38740899

RESUMEN

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.


Asunto(s)
Receptor alfa de Estrógeno , Proteolisis , Proteína Supresora de Tumores del Síndrome de Von Hippel-Lindau , Humanos , Receptor alfa de Estrógeno/metabolismo , Proteína Supresora de Tumores del Síndrome de Von Hippel-Lindau/metabolismo , Proteína Supresora de Tumores del Síndrome de Von Hippel-Lindau/genética , Femenino , Proteolisis/efectos de los fármacos , Animales , Administración Oral , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Línea Celular Tumoral , Ratones , Antineoplásicos/farmacología , Antineoplásicos/administración & dosificación
2.
Am J Trop Med Hyg ; 2024 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-38697074

RESUMEN

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.

3.
Sci Rep ; 13(1): 10031, 2023 06 20.
Artículo en Inglés | MEDLINE | ID: mdl-37340068

RESUMEN

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.


Asunto(s)
Anticuerpos , Antígenos , Ligandos , Unión Proteica , Sitios de Unión , Cinética
4.
Res Sq ; 2023 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-37214831

RESUMEN

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.

5.
Front Mol Biosci ; 10: 1136975, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37033448

RESUMEN

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.

6.
Med Sci Sports Exerc ; 53(11): 2225-2232, 2021 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-34280939

RESUMEN

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.


Asunto(s)
Adiposidad/fisiología , Presión Sanguínea , Capacidad Cardiovascular , Obesidad Infantil/fisiopatología , Alanina Transaminasa/sangre , Niño , Femenino , Tasa de Filtración Glomerular , Homeostasis , Humanos , Hipertensión/sangre , Hipertensión/fisiopatología , Resistencia a la Insulina , Lípidos/sangre , Masculino , Consumo de Oxígeno , Obesidad Infantil/sangre
7.
PLoS Negl Trop Dis ; 15(6): e0009323, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-34106914

RESUMEN

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.


Asunto(s)
Enfermedades de los Bovinos/parasitología , Trypanosoma/clasificación , Tripanosomiasis Africana/parasitología , Zoonosis/parasitología , Animales , Bovinos , Enfermedades de los Bovinos/sangre , Enfermedades de los Bovinos/epidemiología , Chad/epidemiología , Humanos , Especificidad de la Especie , Tripanosomiasis Africana/sangre , Tripanosomiasis Africana/epidemiología
8.
Nutr Health ; 27(2): 273-281, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33331231

RESUMEN

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.


Asunto(s)
Obesidad Infantil , Adolescente , Arkansas , Niño , Ejercicio Físico , Humanos , Obesidad Infantil/epidemiología , Obesidad Infantil/prevención & control , Aptitud Física , Instituciones Académicas
10.
J Phys Chem Lett ; 11(19): 8406-8416, 2020 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-32924494

RESUMEN

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.

11.
Chem Sci ; 11(18): 4578-4583, 2020 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-34122915

RESUMEN

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.

12.
BMC Vet Res ; 15(1): 344, 2019 Oct 16.
Artículo en Inglés | MEDLINE | ID: mdl-31619238

RESUMEN

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.


Asunto(s)
Enfermedades de los Bovinos/epidemiología , Trypanosoma/aislamiento & purificación , Tripanosomiasis Africana/epidemiología , Animales , Capa Leucocitaria de la Sangre/parasitología , Camerún/epidemiología , Bovinos , Enfermedades de los Bovinos/parasitología , Femenino , Genes Protozoarios , Insectos Vectores , Masculino , Prevalencia , Trypanosoma/clasificación , Trypanosoma/genética , Tripanosomiasis Africana/parasitología , Tripanosomiasis Africana/prevención & control , Moscas Tse-Tse
13.
Parasit Vectors ; 12(1): 481, 2019 Oct 14.
Artículo en Inglés | MEDLINE | ID: mdl-31610794

RESUMEN

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.


Asunto(s)
Variación Genética , Insectos Vectores/parasitología , Trypanosoma/genética , Tripanosomiasis Africana/parasitología , Moscas Tse-Tse/parasitología , Animales , ADN Intergénico/química , ADN Intergénico/aislamiento & purificación , ADN Protozoario/aislamiento & purificación , Humanos , Insectos Vectores/clasificación , Nigeria/epidemiología , Filogenia , Reacción en Cadena de la Polimerasa , Prevalencia , Especificidad de la Especie , Trypanosoma/clasificación , Trypanosoma/aislamiento & purificación , Trypanosoma congolense/clasificación , Trypanosoma congolense/genética , Trypanosoma congolense/aislamiento & purificación , Trypanosoma vivax/clasificación , Trypanosoma vivax/genética , Trypanosoma vivax/aislamiento & purificación , Tripanosomiasis Africana/epidemiología , Tripanosomiasis Africana/transmisión , Moscas Tse-Tse/clasificación
14.
Cancer Res ; 79(20): 5407-5417, 2019 10 15.
Artículo en Inglés | MEDLINE | ID: mdl-31455691

RESUMEN

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.


Asunto(s)
Adenocarcinoma/química , Adenocarcinoma/diagnóstico por imagen , Colorantes Fluorescentes/análisis , Peróxido de Hidrógeno/análisis , Imagen Óptica/métodos , Técnicas Fotoacústicas/métodos , Piperazinas/análisis , Absorción de Radiación , Adenocarcinoma/secundario , Animales , Línea Celular Tumoral , Desoxiglucosa/farmacocinética , Colorantes Fluorescentes/síntesis química , Colorantes Fluorescentes/farmacocinética , Colorantes Fluorescentes/toxicidad , Xenoinjertos , Humanos , Peróxido de Hidrógeno/farmacología , Neoplasias Hepáticas/química , Neoplasias Hepáticas/diagnóstico por imagen , Neoplasias Hepáticas/secundario , Células MCF-7 , Ratones , Ratones Desnudos , Imagen Molecular/métodos , Trasplante de Neoplasias , Estrés Oxidativo , Piperazinas/síntesis química , Piperazinas/farmacocinética , Piperazinas/toxicidad , Distribución Tisular
15.
J Immunother Cancer ; 7(1): 181, 2019 07 12.
Artículo en Inglés | MEDLINE | ID: mdl-31300044

RESUMEN

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.


Asunto(s)
Antineoplásicos Inmunológicos/efectos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Melanoma/complicaciones , Melanoma/tratamiento farmacológico , Síndrome Nefrótico/etiología , Anciano , Antineoplásicos Inmunológicos/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Sustitución de Medicamentos , Humanos , Ipilimumab/administración & dosificación , Pruebas de Función Renal , Masculino , Melanoma/diagnóstico , Terapia Molecular Dirigida/efectos adversos , Síndrome Nefrótico/diagnóstico , Nivolumab/administración & dosificación , Receptor de Muerte Celular Programada 1/antagonistas & inhibidores , Resultado del Tratamiento
16.
J Neurosci ; 39(36): 7049-7060, 2019 09 04.
Artículo en Inglés | MEDLINE | ID: mdl-31217331

RESUMEN

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.


Asunto(s)
Corteza Auditiva/metabolismo , Brevicano/genética , Consolidación de la Memoria , Animales , Corteza Auditiva/fisiología , Percepción Auditiva , Brevicano/metabolismo , Discriminación en Psicología , Hipocampo/metabolismo , Hipocampo/fisiología , Masculino , Ratones , Ratones Endogámicos C57BL , Regulación hacia Arriba
17.
BMC Microbiol ; 18(Suppl 1): 180, 2018 11 23.
Artículo en Inglés | MEDLINE | ID: mdl-30470197

RESUMEN

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.


Asunto(s)
Variación Genética , Filogenia , Moscas Tse-Tse/clasificación , Moscas Tse-Tse/genética , Animales , Camerún , ADN Intergénico/genética , Complejo IV de Transporte de Electrones/genética , Femenino , Control de Insectos , Insectos Vectores/clasificación , Insectos Vectores/parasitología , Masculino , Repeticiones de Microsatélite , Nigeria , Dinámica Poblacional
19.
Pediatrics ; 141(5)2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-29669752

RESUMEN

An effective faculty mentoring program (FMP) is 1 approach that academic departments can use to promote professional fulfillment, faculty retention, and mitigate the risks of faculty burnout. Mentoring has both direct benefits for junior faculty mentees as they navigate the academic promotion process with their mentors, in addition to broader departmental and institutional benefits, with regard to recruitment, retention, and academic productivity. We describe a successful FMP model that has been adapted for use in 6 other pediatrics departments, summarizing the key personnel, mentoring process, and program evaluation methods. Important lessons learned and a generalizable mentoring "model" are provided. Program evaluation indicates a positive effect for the FMP on enhanced faculty self-efficacy, job satisfaction, and career development. The importance of communication, oversight, feedback, accountability, and valuing all faculty members is emphasized. Strategies to promote faculty engagement and the critical role of departmental leadership in prioritizing mentorship are discussed. The success of academic medical departments is inextricably linked to its commitment to the career development of individual faculty members at all levels and in all academic pathways. With our findings, we support the positive impact of a formal FMP in promoting enhanced self-efficacy and career satisfaction, which directly benefits the department and institution through enhanced productivity, retention, successful promotion, and overall professional fulfillment.


Asunto(s)
Centros Médicos Académicos/organización & administración , Docentes Médicos/educación , Tutoría , Agotamiento Profesional/prevención & control , Comunicación , Eficiencia , Docentes Médicos/psicología , Humanos , Satisfacción en el Trabajo , Liderazgo , Evaluación de Programas y Proyectos de Salud , Autoeficacia , Responsabilidad Social , Desarrollo de Personal
20.
R Soc Open Sci ; 5(2): 171399, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29515860

RESUMEN

Protein aggregation into amyloid deposits and oxidative stress are key features of many neurodegenerative disorders including Parkinson's and Alzheimer's disease. We report here the creation of four highly sensitive bifunctional fluorescent probes, capable of H2O2 and/or amyloid aggregate detection. These bifunctional sensors use a benzothiazole core for amyloid localization and boronic ester oxidation to specifically detect H2O2. We characterized the optical properties of these probes using both bulk fluorescence measurements and single-aggregate fluorescence imaging, and quantify changes in their fluorescence properties upon addition of amyloid aggregates of α-synuclein and pathophysiological H2O2 concentrations. Our results indicate these new probes will be useful to detect and monitor neurodegenerative disease.

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