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1.
Int J Mol Sci ; 25(7)2024 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-38612548

RESUMEN

Protein phosphorylation is a prevalent translational modification, and its dysregulation has been implicated in various diseases, including cancer. Despite its significance, there is a lack of specific inhibitors of the FCP/SCP-type Ser/Thr protein phosphatase Scp1, characterized by high specificity and affinity. In this study, we focused on adnectin, an antibody-mimetic protein, aiming to identify Scp1-specific binding molecules with a broad binding surface that target the substrate-recognition site of Scp1. Biopanning of Scp1 was performed using an adnectin-presenting phage library with a randomized FG loop. We succeeded in identifying FG-1Adn, which showed high affinity and specificity for Scp1. Ala scanning analysis of the Scp1-binding sequence in relation to the FG-1 peptide revealed that hydrophobic residues, including aromatic amino acids, play important roles in Scp1 recognition. Furthermore, FG-1Adn was found to co-localize with Scp1 in cells, especially on the plasma membrane. In addition, Western blotting analysis showed that FG-1Adn increased the phosphorylation level of the target protein of Scp1 in cells, indicating that FG-1Adn can inhibit the function of Scp1. These results suggest that FG-1Adn can be used as a specific inhibitor of Scp1.


Asunto(s)
Anticuerpos , Dominio de Fibronectina del Tipo III , Proteínas Recombinantes , Aminoácidos Aromáticos , Fosfoproteínas Fosfatasas , Biblioteca de Péptidos
2.
Malar J ; 22(1): 208, 2023 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-37420265

RESUMEN

BACKGROUND: Understanding temporal and spatial dynamics of malaria transmission will help to inform effective interventions and strategies in regions approaching elimination. Parasite genomics are increasingly used to monitor epidemiologic trends, including assessing residual transmission across seasons and importation of malaria into these regions. METHODS: In a low and seasonal transmission setting of southern Zambia, a total of 441 Plasmodium falciparum samples collected from 8 neighbouring health centres between 2012 and 2018 were genotyped using molecular inversion probes (MIPs n = 1793) targeting a total of 1832 neutral and geographically informative SNPs distributed across the parasite genome. After filtering for quality and missingness, 302 samples and 1410 SNPs were retained and used for downstream population genomic analyses. RESULTS: The analyses revealed most (67%, n = 202) infections harboured one clone (monogenomic) with some variation at local level suggesting low, but heterogenous malaria transmission. Relatedness identity-by-descent (IBD) analysis revealed variable distribution of IBD segments across the genome and 6% of pairs were highly-related (IBD ≥ 0.25). Some of the highly-related parasite populations persisted across multiple seasons, suggesting that persistence of malaria in this low-transmission region is fueled by parasites "seeding" across the dry season. For recent years, clusters of clonal parasites were identified that were dissimilar to the general parasite population, suggesting parasite populations were increasingly fragmented at small spatial scales due to intensified control efforts. Clustering analysis using PCA and t-SNE showed a lack of substantial parasite population structure. CONCLUSION: Leveraging both genomic and epidemiological data provided comprehensive picture of fluctuations in parasite populations in this pre-elimination setting of southern Zambia over 7 years.


Asunto(s)
Malaria Falciparum , Malaria , Parásitos , Animales , Humanos , Plasmodium falciparum/genética , Malaria Falciparum/parasitología , Zambia/epidemiología , Análisis Espacial , Genómica
3.
Stat Med ; 42(9): 1445-1460, 2023 04 30.
Artículo en Inglés | MEDLINE | ID: mdl-36872556

RESUMEN

Protein microarrays are a promising technology that measure protein levels in serum or plasma samples. Due to their high technical variability and high variation in protein levels across serum samples in any population, directly answering biological questions of interest using protein microarray measurements is challenging. Analyzing preprocessed data and within-sample ranks of protein levels can mitigate the impact of between-sample variation. As for any analysis, ranks are sensitive to preprocessing, but loss function based ranks that accommodate major structural relations and components of uncertainty are very effective. Bayesian modeling with full posterior distributions for quantities of interest produce the most effective ranks. Such Bayesian models have been developed for other assays, for example, DNA microarrays, but modeling assumptions for these assays are not appropriate for protein microarrays. Consequently, we develop and evaluate a Bayesian model to extract the full posterior distribution of normalized protein levels and associated ranks for protein microarrays, and show that it fits well to data from two studies that use protein microarrays produced by different manufacturing processes. We validate the model via simulation and demonstrate the downstream impact of using estimates from this model to obtain optimal ranks.


Asunto(s)
Análisis por Matrices de Proteínas , Humanos , Teorema de Bayes , Simulación por Computador , Análisis de Secuencia por Matrices de Oligonucleótidos
4.
Acta Neurochir (Wien) ; 165(3): 789-795, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36781462

RESUMEN

BACKGROUND: The clinical outcomes and radiographic changes of a one-stage procedure combining cervical laminoplasty and unilateral cervical foraminotomy for patients with coexisting cervical myelopathy and unilateral radiculopathy were evaluated. METHODS: Seven patients (two females and five males) with coexisting cervical myelopathy and unilateral cervical radiculopathy were included in this study. The mean age was 58.4 years (range 45-77 years). Cervical laminoplasty and unilateral cervical foraminotomy were performed on the recruited patients in a single stage. The quantitative clinical changes between the preoperative and 6-month postoperative assessment were analyzed using the Japanese Orthopedic Association (JOA) score, the JOA Cervical Myelopathy Evaluation Questionnaire (JOA-CMEQ), visual analog scale (VAS), and Neck Disability Index (NDI). Moreover, the preoperative and 6-month postoperative radiographic changes were assessed using the C2-7 angle and range of motion (ROM) between flexion and extension angle. RESULTS: There were significant differences in QOL in the JOA-CMEQ between the groups. Furthermore, the postoperative VAS values in the arms and hands generally improved, although not significantly, between the groups. CONCLUSIONS: The aforementioned surgical procedure may be safe and efficient for patients with coexisting cervical myelopathy and radiculopathy.


Asunto(s)
Foraminotomía , Laminoplastia , Radiculopatía , Enfermedades de la Médula Espinal , Masculino , Femenino , Humanos , Persona de Mediana Edad , Anciano , Radiculopatía/cirugía , Laminoplastia/métodos , Calidad de Vida , Resultado del Tratamiento , Vértebras Cervicales/cirugía , Enfermedades de la Médula Espinal/cirugía , Estudios Retrospectivos
5.
Int J Mol Sci ; 24(14)2023 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-37511324

RESUMEN

Metal ions are used in various situations in living organisms and as a part of functional materials. Since the excessive intake of metal ions can cause health hazards and environmental pollution, the development of new molecules that can monitor metal ion concentrations with high sensitivity and selectivity is strongly desired. DNA can form various structures, and these structures and their properties have been used in a wide range of fields, including materials, sensors, and drugs. Guanine-rich sequences respond to metal ions and form G-quadruplex structures and G-wires, which are the self-assembling macromolecules of G-quadruplex structures. Therefore, guanine-rich DNA can be applied to a metal ion-detection sensor and functional materials. In this study, the IRDAptamer library originally designed based on G-quadruplex structures was used to screen for Mn2+, which is known to induce neurodegenerative diseases. Circular dichroism and fluorescence analysis using Thioflavin T showed that the identified IRDAptamer sequence designated MnG4C1 forms a non-canonical G-quadruplex structure in response to low concentrations of Mn2+. A serum resistance and thermostability analysis revealed that MnG4C1 acquired stability in a Mn2+-dependent manner. A Förster resonance energy transfer (FRET) system using fluorescent molecules attached to the termini of MnG4C1 showed that FRET was effectively induced based on Mn2+-dependent conformational changes, and the limit of detection (LOD) was 0.76 µM for Mn2+. These results suggested that MnG4C1 can be used as a novel DNA-based Mn2+-detecting molecule.


Asunto(s)
Técnicas Biosensibles , G-Cuádruplex , ADN/química , Técnicas Biosensibles/métodos , Iones , Guanina/química
6.
Proteomics ; 22(3): e2100033, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34668656

RESUMEN

Technical variation, or variation from non-biological sources, is present in most laboratory assays. Correcting for this variation enables analysts to extract a biological signal that informs questions of interest. However, each assay has different sources and levels of technical variation, and the choice of correction methods can impact downstream analyses. Compared to similar assays such as DNA microarrays, relatively few methods have been developed and evaluated for protein microarrays, a versatile tool for measuring levels of various proteins in serum samples. Here, we propose a pre-processing pipeline to correct for some common sources of technical variation in protein microarrays. The pipeline builds upon an existing normalization method by using controls to reduce technical variation. We evaluate our method using data from two protein microarray studies and by simulation. We demonstrate that pre-processing choices impact the fluorescent-intensity based ranks of proteins, which in turn, impact downstream analysis.


Asunto(s)
Perfilación de la Expresión Génica , Análisis por Matrices de Proteínas , Simulación por Computador , Perfilación de la Expresión Génica/métodos , Análisis de Secuencia por Matrices de Oligonucleótidos/métodos
7.
FASEB J ; 35(6): e21673, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-34042213

RESUMEN

Lysophosphatidylinositol (LPI) is a glycero-lysophospholipid and a natural agonist against GPR55. The roles of the LPI/GPR55 axis in the pathogenesis of inflammation have been controversial. In the present study, we attempted to elucidate the roles of the LPI/GPR55 axis in inflammation, especially the secretion of inflammatory cytokines, IL-6 and TNF-α from macrophages. We treated RAW264.7 cells and mouse peritoneal macrophages (MPMs) with LPI and observed that LPI induced the secretion of IL-6 and TNF-α from these cells, as well as the phosphorylation of p38. These responses were inhibited by treatment with CID16020046 (CID), an antagonist against GPR55, or SB202190, an inhibitor of p38 cascade or knockdown of GPR55 with siRNA. Treatment with CID or ML-193, another antagonist against GPR55, attenuated the elevation of inflammatory cytokines in the plasma or tissue of db/db mice and in a septic mouse model induced using lipopolysaccharide, suggesting contributions to the improvement of insulin resistance and protection against organ injuries by treatment with CID or ML-193, respectively. In human subjects, although the serum LPI levels were not different, the levels of LPI in the lipoprotein fractions were lower and the levels in the lipoprotein-depleted fractions were higher in subjects with diabetes. LPI bound to albumin induced the secretion of IL-6 and TNF-α from RAW264.7 cells to a greater degree than LPI bound to LDL or HDL. These results suggest that LPI, especially the albumin-bound form, induced inflammatory cytokines depending on the GPR55/p38 pathway, which might contribute to the pathogenesis of obesity-induced inflammation and acute inflammation.


Asunto(s)
Albúminas/metabolismo , Citocinas/metabolismo , Diabetes Mellitus Experimental/inmunología , Diabetes Mellitus Tipo 2/inmunología , Mediadores de Inflamación/metabolismo , Lisofosfolípidos/farmacología , Macrófagos/inmunología , Animales , Diabetes Mellitus Experimental/tratamiento farmacológico , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patología , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/patología , Humanos , Sistema de Señalización de MAP Quinasas , Macrófagos/metabolismo , Macrófagos/patología , Ratones , Ratones Endogámicos C57BL
8.
J Gastroenterol Hepatol ; 37(4): 678-684, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-34911147

RESUMEN

BACKGROUND AND AIM: Recently, multimodal representation learning for images and other information such as numbers or language has gained much attention. The aim of the current study was to analyze the diagnostic performance of deep multimodal representation model-based integration of tumor image, patient background, and blood biomarkers for the differentiation of liver tumors observed using B-mode ultrasonography (US). METHOD: First, we applied supervised learning with a convolutional neural network (CNN) to 972 liver nodules in the training and development sets to develop a predictive model using segmented B-mode tumor images. Additionally, we also applied a deep multimodal representation model to integrate information about patient background or blood biomarkers to B-mode images. We then investigated the performance of the models in an independent test set of 108 liver nodules. RESULTS: Using only the segmented B-mode images, the diagnostic accuracy and area under the curve (AUC) values were 68.52% and 0.721, respectively. As the information about patient background and blood biomarkers was integrated, the diagnostic performance increased in a stepwise manner. The diagnostic accuracy and AUC value of the multimodal DL model (which integrated B-mode tumor image, patient age, sex, aspartate aminotransferase, alanine aminotransferase, platelet count, and albumin data) reached 96.30% and 0.994, respectively. CONCLUSION: Integration of patient background and blood biomarkers in addition to US image using multimodal representation learning outperformed the CNN model using US images. We expect that the deep multimodal representation model could be a feasible and acceptable tool for the definitive diagnosis of liver tumors using B-mode US.


Asunto(s)
Neoplasias Hepáticas , Área Bajo la Curva , Humanos , Neoplasias Hepáticas/diagnóstico por imagen , Redes Neurales de la Computación , Ultrasonografía/métodos
9.
J Infect Dis ; 223(2): 306-309, 2021 02 03.
Artículo en Inglés | MEDLINE | ID: mdl-32594154

RESUMEN

Removal of chloroquine from national malaria formularies can lead to the reversion of resistant Plasmodium falciparum to wild-type. We report a steep decline in chloroquine-resistant P falciparum within 10 years of national discontinuation of chloroquine monotherapy in Zimbabwe. Drug resistance surveillance is a vital component of malaria control programs, and the experience with chloroquine in Zimbabwe and elsewhere in sub-Saharan Africa is illustrative of the potentially rapid and dramatic impact of drug policy on antimalarial resistance.


Asunto(s)
Cloroquina/farmacología , Resistencia a Medicamentos , Malaria Falciparum/epidemiología , Malaria Falciparum/parasitología , Carga de Parásitos , Plasmodium falciparum/efectos de los fármacos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Cloroquina/uso terapéutico , Femenino , Humanos , Lactante , Malaria Falciparum/tratamiento farmacológico , Masculino , Persona de Mediana Edad , Vigilancia en Salud Pública , Adulto Joven , Zimbabwe/epidemiología
10.
Malar J ; 20(1): 14, 2021 Jan 06.
Artículo en Inglés | MEDLINE | ID: mdl-33407488

RESUMEN

BACKGROUND: Microscopy and rapid diagnostic tests (RDTs) are the main techniques used to diagnose malaria. While microscopy is considered the gold standard, RDTs have established popularity as they allow for rapid diagnosis with minimal technical skills. This study aimed to compare the diagnostic performance of two Plasmodium falciparum histidine-rich protein 2 (PfHRP2)-based RDTs (Paracheck Pf® Test (Paracheck) and Malaria Pf™ ICT (ICT)) to polymerase chain reaction (PCR) in a community survey. METHODS: A cross-sectional study was conducted between October 2012 and December 2014 in Mutasa District, Manicaland Province, eastern Zimbabwe. Households were randomly selected using satellite imagery, and 224 households were visited. Residents present in the household on the date of the visit were recruited for the study. Participants of all age groups from the selected households were screened with Paracheck and ICT RDTs in parallel. Dried blood spots (DBS) and thin and thick smears were collected. Parasite DNA extracted from the DBS was subjected to nested PCR targeting the Plasmodium cytochrome b mitochondrial gene. Data analysis was performed using the Cohen's Kappa test to determine the interrater agreement and the sensitivity and specificity of the diagnostic test were reported. RESULTS: Results from a total of 702 participants were analysed. Most were females, 397 (57%), and the median age of participants was 21 years with an interquartile range of 9-39 years. Of those who were screened, 8 (1.1%), 35 (5.0%), and 21 (2.9%) were malaria parasite positive by microscopy, RDT and PCR, respectively. Paracheck and ICT RDTs had a 100% agreement. Comparing RDT and PCR results, 34 participants (4.8%) had discordant results. Most of the discordant cases were RDT positive but PCR negative (n = 24). Half of those RDT positive, but PCR negative individuals reported anti-malarials to use in the past month, which is significantly higher than reported anti-malarial drug use in the population (p < 0.001). The participant was febrile on the day of the visit, but relying on PfHRP2-based RDT would miss this case. Among the diagnostic methods evaluated, with reference to PCR, the sensitivity was higher with the RDT (52.4%) while specificity was higher with the microscopy (99.9%). The positive predictive value (PPV) was higher with the microscopy (87.5%), while the negative predictive values were similar for both microscopy and RDTs (98%). Overall, a strong correlated agreement with PCR was observed for the microscopy (97.9%) and the RDTs (95.2%). CONCLUSIONS: Paracheck and ICT RDTs showed 100% agreement and can be used interchangeably. As malaria transmission declines and Zimbabwe aims to reach malaria elimination, management of infected individuals with low parasitaemia as well as non-P. falciparum infection can be critical.


Asunto(s)
Malaria Falciparum/epidemiología , Parasitemia/epidemiología , Plasmodium falciparum/aislamiento & purificación , Adolescente , Adulto , Niño , Preescolar , Estudios Transversales , Pruebas Diagnósticas de Rutina/métodos , Femenino , Humanos , Malaria Falciparum/parasitología , Masculino , Persona de Mediana Edad , Parasitemia/parasitología , Prevalencia , Sensibilidad y Especificidad , Adulto Joven , Zimbabwe/epidemiología
11.
Malar J ; 19(1): 175, 2020 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-32381005

RESUMEN

BACKGROUND: Reactive case detection (RCD) seeks to enhance malaria surveillance and control by identifying and treating parasitaemic individuals residing near index cases. In Zambia, this strategy starts with passive detection of symptomatic incident malaria cases at local health facilities or by community health workers, with subsequent home visits to screen-and-treat residents in the index case and neighbouring (secondary) households within a 140-m radius using rapid diagnostic tests (RDTs). However, a small circular radius may not be the most efficient strategy to identify parasitaemic individuals in low-endemic areas with hotspots of malaria transmission. To evaluate if RCD efficiency could be improved by increasing the probability of identifying parasitaemic residents, environmental risk factors and a larger screening radius (250 m) were assessed in a region of low malaria endemicity. METHODS: Between January 12, 2015 and July 26, 2017, 4170 individuals residing in 158 index and 531 secondary households were enrolled and completed a baseline questionnaire in the catchment area of Macha Hospital in Choma District, Southern Province, Zambia. Plasmodium falciparum prevalence was measured using PfHRP2 RDTs and quantitative PCR (qPCR). A Quickbird™ high-resolution satellite image of the catchment area was used to create environmental risk factors in ArcGIS, and generalized estimating equations were used to evaluate associations between risk factors and secondary households with parasitaemic individuals. RESULTS: The parasite prevalence in secondary (non-index case) households was 0.7% by RDT and 1.8% by qPCR. Overall, 8.5% (n = 45) of secondary households had at least one resident with parasitaemia by qPCR or RDT. The risk of a secondary household having a parasitaemic resident was significantly increased in proximity to higher order streams and marginally with increasing distance from index households. The adjusted OR for proximity to third- and fifth-order streams were 2.97 (95% CI 1.04-8.42) and 2.30 (95% CI 1.04-5.09), respectively, and that for distance to index households for each 50 m was 1.24 (95% CI 0.98-1.58). CONCLUSION: Applying proximity to streams as a screening tool, 16% (n = 3) more malaria-positive secondary households were identified compared to using a 140-m circular screening radius. This analysis highlights the potential use of environmental risk factors as a screening strategy to increase RCD efficiency.


Asunto(s)
Pruebas Diagnósticas de Rutina/estadística & datos numéricos , Malaria Falciparum/epidemiología , Adolescente , Adulto , Niño , Preescolar , Estudios Transversales , Erradicación de la Enfermedad/estadística & datos numéricos , Humanos , Lactante , Recién Nacido , Malaria Falciparum/prevención & control , Persona de Mediana Edad , Plasmodium falciparum/aislamiento & purificación , Prevalencia , Adulto Joven , Zambia/epidemiología
12.
BMC Public Health ; 20(1): 1083, 2020 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-32646393

RESUMEN

BACKGROUND: Many countries are striving to become malaria-free, but global reduction in case estimates has stagnated in recent years. Substandard and falsified medicines may contribute to this lack of progress. Zambia aims to eliminate their annual burden of 1.2 million pediatric malaria cases and 2500 child deaths due to malaria. We examined the health and economic impact of poor-quality antimalarials in Zambia. METHODS: An agent-based model, Substandard and Falsified Antimalarial Research Impact (SAFARI), was modified and applied to Zambia. The model was developed to simulate population characteristics, malaria incidence, patient care-seeking, disease progression, treatment outcomes, and associated costs of malaria for children under age five. Zambia-specific demographic, epidemiological, and cost inputs were extracted from the literature. Simulations were run to estimate the health and economic impact of poor-quality antimalarials, the effect of potential artemisinin resistance, and six additional malaria focused policy interventions. RESULTS: We simulated annual malaria cases among Zambian children under five. At baseline, we found 2610 deaths resulting in $141.5 million in annual economic burden of malaria. We estimated that elimination of substandard and falsified antimalarials would result in an 8.1% (n = 213) reduction in under-five deaths, prevent 937 hospitalizations, and realize $8.5 million in economic savings, annually. Potential artemisinin resistance could further increase deaths by 6.3% (n = 166) and cost an additional $9.7 million every year. CONCLUSIONS: Eliminating substandard and falsified antimalarials is an important step towards a malaria-free Zambia. Beyond the dissemination of insecticide-treated bed nets, indoor residual spraying, and other malaria control measures, attention must also be paid to assure the quality of antimalarial treatments.


Asunto(s)
Antimaláricos/normas , Antimaláricos/uso terapéutico , Medicamentos Falsificados/provisión & distribución , Malaria/tratamiento farmacológico , Malaria/epidemiología , Antimaláricos/provisión & distribución , Artemisininas , Niño , Preescolar , Simulación por Computador , Medicamentos Falsificados/economía , Humanos , Renta , Lactante , Malaria/mortalidad , Modelos Económicos , Modelos Teóricos , Aceptación de la Atención de Salud , Zambia
13.
J Infect Dis ; 219(8): 1254-1263, 2019 04 08.
Artículo en Inglés | MEDLINE | ID: mdl-30445612

RESUMEN

BACKGROUND: Southern Province, Zambia has experienced a dramatic decline in Plasmodium falciparum malaria transmission in the past decade and is targeted for elimination. Zambia's National Malaria Elimination Program recommends reactive case detection (RCD) within 140 m of index households to enhance surveillance and eliminate remaining transmission foci. METHODS: To evaluate whether RCD captures local transmission, we genotyped 26 microsatellites from 106 samples collected from index (n = 27) and secondary (n = 79) cases detected through RCD in the Macha Hospital catchment area between January 2015 and April 2016. RESULTS: Participants from the same RCD event harbored more genetically related parasites than those from different RCD events, suggesting that RCD captures, at least in part, infections related through local transmission. Related parasites clustered in space and time, up to at least 250 m from index households. Spatial analysis identified a putative focal transmission hotspot. CONCLUSIONS: The current RCD strategy detects focal transmission events, although programmatic guidelines to screen within 140 m of index households may fail to capture all secondary cases. This study highlights the utility of parasite genetic data in assessing programmatic interventions, and similar approaches may be useful to malaria elimination programs seeking to tailor intervention strategies to the underlying transmission epidemiology.


Asunto(s)
Malaria Falciparum/transmisión , Plasmodium falciparum/genética , Erradicación de la Enfermedad/métodos , Técnicas de Genotipaje , Humanos , Malaria Falciparum/parasitología , Repeticiones de Microsatélite/genética , Vigilancia de la Población , Análisis Espacio-Temporal , Zambia/epidemiología
14.
Am J Epidemiol ; 188(12): 2120-2130, 2019 12 31.
Artículo en Inglés | MEDLINE | ID: mdl-31062839

RESUMEN

Malaria transmission in northern Zambia has increased in the past decade, despite malaria control activities. Evidence-based intervention strategies are needed to effectively reduce malaria transmission. Zambia's National Malaria Control Centre conducted targeted indoor residual spraying (IRS) in Nchelenge District, Luapula Province, from 2014 to 2016 using the organophosphate insecticide pirimiphos-methyl. An evaluation of the IRS campaign was conducted by the Southern Africa International Centers of Excellence for Malaria Research using actively detected malaria cases in bimonthly household surveys carried out from April 2012 to July 2017. Changes in malaria parasite prevalence after IRS were assessed by season using Poisson regression models with robust standard errors, controlling for clustering of participants in households and demographic, geographical, and climatological covariates. In targeted areas, parasite prevalence declined approximately 25% during the rainy season following IRS with pirimiphos-methyl but did not decline during the dry season or in the overall study area. Within targeted areas, parasite prevalence declined in unsprayed households, suggesting both direct and indirect effects of IRS. The moderate decrease in parasite prevalence within sprayed areas indicates that IRS with pirimiphos-methyl is an effective malaria control measure, but a more comprehensive package of interventions is needed to effectively reduce the malaria burden in this setting.


Asunto(s)
Insecticidas , Malaria/epidemiología , Control de Mosquitos/métodos , Mosquitos Vectores , Compuestos Organotiofosforados , Adolescente , Niño , Preescolar , Femenino , Humanos , Malaria/prevención & control , Malaria/transmisión , Masculino , Zambia/epidemiología
15.
Malar J ; 18(1): 78, 2019 Mar 13.
Artículo en Inglés | MEDLINE | ID: mdl-30866956

RESUMEN

BACKGROUND: The Plasmodium falciparum histidine-rich protein II (PfHRP2) is a common biomarker used in malaria rapid diagnostic tests (RDTs), but can persist in the blood for up to 40 days following curative treatment. The persistence of PfHRP2 presents a false positive limitation to diagnostic interpretation. However, the in vivo dynamics and compartmentalization underlying PfHRP2 persistence have not been fully characterized in the plasma and erythrocyte (RBC) fraction of the whole blood. METHODS: The kinetics and persistence of PfHRP2 in the plasma and RBC fractions of the whole blood were investigated post-treatment in human clinical samples and samples isolated from BALB/c mice infected with a novel transgenic Plasmodium berghei parasite engineered to express PfHRP2 (PbPfHRP2). RESULTS: PfHRP2 levels in human RBCs were consistently 20-40 times greater than plasma levels, even post-parasite clearance. PfHRP2 positive, DNA negative, once-infected RBCs were identified in patients that comprised 0.1-1% of total RBCs for 6 and 12 days post-treatment, even post-atovaquone-proguanil regimens. Transgenic PbPfHRP2 parasites in BALB/c mice produced and exported tgPfHRP2 to the RBC cytosol similar to P. falciparum. As in humans, tgPfHRP2 levels were found to be approximately 20-fold higher within the RBC fraction than the plasma post-treatment. RBC localized tgPfHRP2 persisted longer than tgPfHRP2 in the plasma after curative treatment. tgPfHRP2 positive, but DNA negative once-infected RBCs were also detected in mouse peripheral blood for 7-9 days after curative treatment. CONCLUSIONS: The data suggest that persistence of PfHRP2 is due to slower clearance of protein from the RBC fraction of the whole blood. This appears to be a result of the presence PfHRP2 in previously infected, pitted cells, as opposed to PfHRP2 binding naïve RBCs in circulation post-treatment. The results thus confirm that the extended duration of RDT positivity after parasite clearance is likely due to pitted, once-infected RBCs that remain positive for PfHRP2.


Asunto(s)
Antígenos de Protozoos/sangre , Antimaláricos/administración & dosificación , Eritrocitos/química , Malaria Falciparum/tratamiento farmacológico , Malaria Falciparum/patología , Plasma/química , Proteínas Protozoarias/sangre , Animales , Modelos Animales de Enfermedad , Femenino , Humanos , Ratones , Ratones Endogámicos BALB C , Factores de Tiempo
16.
Malar J ; 18(1): 400, 2019 Dec 04.
Artículo en Inglés | MEDLINE | ID: mdl-31801548

RESUMEN

BACKGROUND: While the utility of parasite genotyping for malaria elimination has been extensively documented in low to moderate transmission settings, it has been less well-characterized in holoendemic regions. High malaria burden settings have received renewed attention acknowledging their critical role in malaria elimination. Defining the role for parasite genomics in driving these high burden settings towards elimination will enhance future control programme planning. METHODS: Amplicon deep sequencing was used to characterize parasite population genetic diversity at polymorphic Plasmodium falciparum loci, Pfama1 and Pfcsp, at two timepoints in June-July 2016 and January-March 2017 in a high transmission region along the international border between Luapula Province, Zambia and Haut-Katanga Province, the Democratic Republic of the Congo (DRC). RESULTS: High genetic diversity was observed across both seasons and in both countries. No evidence of population structure was observed between parasite populations on either side of the border, suggesting that this region may be one contiguous transmission zone. Despite a decline in parasite prevalence at the sampling locations in Haut-Katanga Province, no genetic signatures of a population bottleneck were detected, suggesting that larger declines in transmission may be required to reduce parasite genetic diversity. Analysing rare variants may be a suitable alternative approach for detecting epidemiologically important genetic signatures in highly diverse populations; however, the challenge is distinguishing true signals from potential artifacts introduced by small sample sizes. CONCLUSIONS: Continuing to explore and document the utility of various parasite genotyping approaches for understanding malaria transmission in holoendemic settings will be valuable to future control and elimination programmes, empowering evidence-based selection of tools and methods to address pertinent questions, thus enabling more efficient resource allocation.


Asunto(s)
Variación Genética , Malaria Falciparum/prevención & control , Plasmodium falciparum/genética , República Democrática del Congo/epidemiología , Malaria Falciparum/epidemiología , Estaciones del Año , Zambia/epidemiología
17.
Hepatol Res ; 49(3): 304-313, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30182424

RESUMEN

AIM: Liver fibrosis caused by congestive hepatopathy has emerged as an important complication after Fontan procedure. We evaluated the utility of the hepatic vein (HV) waveform using Doppler ultrasound for identification of liver fibrosis in Fontan patients. METHODS: We investigated the HV waveforms in 41 Fontan patients and assessed correlations with clinical parameters, liver fibrosis markers, and hemodynamic data. RESULTS: Based on our preliminary analysis of 64 adult patients with chronic liver disease who underwent liver biopsy, we classified HV waveforms into five types with reference to the degree of flattening (from type 1, normal triphasic waveform; to type 5, a monophasic waveform indicating cirrhosis), and confirmed a significant correlation between waveform pattern and fibrosis stage. Notably, we detected HV waveforms in all of the Fontan patients and classified them into five types. The HV waveform pattern positively correlated with γ-glutamyl transferase and hyaluronic acid levels, and negatively correlated with albumin level and platelet count, but did not correlate with central venous pressure or brain natriuretic peptide level, suggesting that HV waveform could reflect pathophysiological changes in the liver without being affected by hepatic congestion. The highest area under the receiver operating characteristic curve of the HV waveform for detecting advanced liver fibrosis, as defined by ultrasonic findings and clinical features, was 0.829 (81.8% sensitivity, 73.3% specificity), which was higher than that of other non-invasive fibrosis markers. CONCLUSIONS: Hepatic vein waveforms change in accordance with liver fibrosis progression in Fontan patients, and can be a useful indicator of liver fibrosis after the Fontan procedure.

18.
Int J Health Geogr ; 18(1): 19, 2019 08 19.
Artículo en Inglés | MEDLINE | ID: mdl-31426819

RESUMEN

BACKGROUND: Human movement is a driver of malaria transmission and has implications for sustainable malaria control. However, little research has been done on the impact of fine-scale movement on malaria transmission and control in high-transmission settings. As interest in targeted malaria control increases, evaluations are needed to determine the appropriateness of these strategies in the context of human mobility across a variety of transmission settings. METHODS: A human mobility study was conducted in Nchelenge District, a high-transmission setting in northern Zambia. Over 1 year, 84 participants were recruited from active malaria surveillance cohorts to wear a global positioning system data logger for 1 month during all daily activity. Participants completed a survey questionnaire and underwent malaria testing and treatment at the time of logger distribution and at collection 1 month later. Incident malaria infections were identified using polymerase chain reaction. Participant movement was characterized throughout the study area and across areas targeted for an indoor residual spraying (IRS) intervention. Participant movement patterns were compared using movement intensity maps, activity space plots, and statistical analyses. Malaria risk was characterized across participants using spatial risk maps and time spent away from home during peak vector biting hours. RESULTS: Movement data were collected from 82 participants, and 63 completed a second study visit. Participants exhibited diverse mobility patterns across the study area, including movement into and out of areas targeted for IRS, potentially mitigating the impact of IRS on parasite prevalence. Movement patterns did not differ significantly by season or age, but male participants traveled longer distances and spent more time away from home. Monthly malaria incidence was 22%, and malaria risk was characterized as high across participants. Participants with incident parasitemia traveled a shorter distance and spent more time away from home during peak biting hours; however, these relationships were not statistically significant, and malaria risk score did not differ by incident parasitemia. CONCLUSIONS: Individual movement patterns in Nchelenge District, Zambia have implications for malaria control, particularly the effectiveness of targeted IRS strategies. Large and fine-scale population mobility patterns should be considered when planning intervention strategies across transmission settings.


Asunto(s)
Sistemas de Información Geográfica , Malaria/epidemiología , Malaria/transmisión , Control de Mosquitos/métodos , Movimiento , Conducta Espacial , Adolescente , Adulto , Anciano , Estudios Transversales , Interpretación Estadística de Datos , Femenino , Estudios de Seguimiento , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Movimiento/fisiología , Conducta Espacial/fisiología , Factores de Tiempo , Adulto Joven , Zambia/epidemiología
19.
Chem Pharm Bull (Tokyo) ; 66(3): 243-250, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29491258

RESUMEN

Phosphodiesterase (PDE) 10A is a dual hydrolase of cAMP and cGMP and highly expressed in striatal medium spiny neurons. Inhibition of PDE10A modulates the activity of medium spiny neurons (MSN) via the regulation of cAMP and cGMP. Signal control of MSN is considered associated with psychotic symptoms. Therefore PDE10A inhibitor is expected as a therapeutic method for psychosis disease such as schizophrenia. Avanafil (1) is a PDE5 inhibitor (treatment for erectile dysfunction) discovered by our company. We paid attention to the homology of PDE10A and PDE5 and took advantage of PDE5 inhibitor library to discover PDE10A inhibitors, and found a series of compounds that exhibit higher potency for PDE10A than PDE5. We transformed the afforded derivatives, which had weak inhibitory activity against PDE10A, and discovered stilbene as a PDE10A inhibitor. Brain penetration of this compound was improved by further conversion of N-containing heterocycles and their substituents. The afforded dimethylaminopyrimidine was effective for rat conditioned avoidance response (CAR) test; however, it did not exhibit good brain penetration. We performed in-depth optimization focusing on substituents of the quinoxaline ring, and produced 3-methyl-7-fluoro quinoxaline. This compound was the most effective in rat CAR test due to its strong PDE10A inhibitory activity and good pharmacokinetics.


Asunto(s)
Inhibidores de Fosfodiesterasa/química , Hidrolasas Diéster Fosfóricas/química , Pirimidinas/química , Pirimidinas/farmacología , Quinoxalinas/química , Animales , Reacción de Prevención/efectos de los fármacos , Sitios de Unión , Cristalografía por Rayos X , Evaluación Preclínica de Medicamentos , Concentración 50 Inhibidora , Simulación de Dinámica Molecular , Inhibidores de Fosfodiesterasa/metabolismo , Inhibidores de Fosfodiesterasa/farmacología , Hidrolasas Diéster Fosfóricas/metabolismo , Pirimidinas/síntesis química , Quinoxalinas/síntesis química , Quinoxalinas/farmacología , Ratas , Relación Estructura-Actividad
20.
No Shinkei Geka ; 46(10): 917-924, 2018 Oct.
Artículo en Japonés | MEDLINE | ID: mdl-30369495

RESUMEN

In recent years, stereotactic electroencephalography(SEEG)has been focused on as a new invasive method for epileptic focus detection. Although the covering area of the brain surface is smaller than the invasive estimation with subdural electrodes, SEEG can evaluate foci that are deeply seated, noncontiguous leaves, and/or bilateral hemispheres. In addition, SEEG can capture consecutive changes in seizure activity in three dimensions. Due to the development of neuroimaging, computer-assisted, and robotic surgery technology, SEEG insertion began to be commonly used worldwide. Although the approximate complication rates of SEEG are estimated as 1% to 3%, which is lower than that of subdural electrode implantation, the risks of major complications, such as permanent neurological deficit and death, are equivalent. Therefore, meticulous procedure must be needed. To introduce SEEG for intractable partial epilepsy, we acquired approval from the institutional review board and concurrently imported surgical devices and electrodes from the manufacturer in the United States for two surgical candidates. We safely performed SEEG insertion, focal identification, and brain functional mapping by cortical electrical stimulation in two cases. Insertion was difficult for some electrodes, which could be due to the lack of adequate surgical device and large skull angle. Hopefully, the official installation of SEEG will be planned in the near future. We hereby reported tips and pitfalls of SEEG implantation through our own experience in a single institute.


Asunto(s)
Electroencefalografía , Epilepsias Parciales , Epilepsia , Mapeo Encefálico , Electrodos Implantados , Epilepsias Parciales/diagnóstico , Epilepsia/diagnóstico , Humanos , Técnicas Estereotáxicas
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