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PURPOSE: The purpose of this study was to assess if multicriteria optimization could limit interoperator variability in radiation therapy planning and assess if this method could contribute to target volume coverage and sparing of organ at risk for intensity-modulated curative radiation therapy of head and neck cancers. MATERIAL AND METHODS: We performed a retrospective analysis on 20 patients treated for an oropharyngeal or oral cavity squamous cell carcinoma. We carried out a comparative dosimetric study of manual plans produced with Precision® software, compared with the plans proposed using the multicriteria optimization method (RayStation®). We assessed interoperator reproducibility on the first six patients, and dosimetric contribution in sparing organs at risk using the multicriteria optimization method. RESULTS: Median age was 69 years, most lesions were oropharyngeal carcinoma (65%), and 35% lesions were stage T3. First, we obtained a high degree of similarity between the four operator measurements for each patient at the level of each organ. Intraclass correlation coefficients were greater than 0.85. Second, we observed a significant dosimetric benefit for contralateral parotid gland, homolateral and contralateral masseter muscles, homolateral and contralateral pterygoid muscles and for the larynx (P<0.05). For the contralateral parotid gland, the mean dose difference between the multicriteria optimization and manual plans was -2.0Gy (P=0.01). Regarding the larynx, the mean dose difference between the two plans was -4.6Gy (P<0.001). CONCLUSION: Multicriteria optimization is a reproducible technique and faster than manual optimization. It allows dosimetric advantages on organs at risk, especially for those not usually taken into consideration in manual dosimetry. This may lead to improved quality of life.
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Órganos en Riesgo , Planificación de la Radioterapia Asistida por Computador , Radioterapia de Intensidad Modulada , Humanos , Estudios Retrospectivos , Planificación de la Radioterapia Asistida por Computador/métodos , Anciano , Masculino , Femenino , Persona de Mediana Edad , Radioterapia de Intensidad Modulada/métodos , Dosificación Radioterapéutica , Neoplasias de Cabeza y Cuello/radioterapia , Carcinoma de Células Escamosas de Cabeza y Cuello/radioterapia , Anciano de 80 o más Años , Neoplasias Orofaríngeas/radioterapia , Reproducibilidad de los Resultados , Neoplasias de la Boca/radioterapia , Carcinoma de Células Escamosas/radioterapia , Carcinoma de Células Escamosas/patología , Variaciones Dependientes del ObservadorRESUMEN
Introduction: Studies have consistently demonstrated increased stress sensitivity in individuals with psychosis. Since stress sensitivity may play a role in the onset and maintenance of psychosis, this could potentially be a promising target for treatment. The current study was the first to investigate whether reactivity to and recovery from daily-life stressors in psychosis change in response to treatment, namely virtual-reality-based cognitive behavioral therapy (VR-CBT). Methods: 116 patients were randomized to either VR-CBT or the waiting list control group (WL). Pre-treatment and post-treatment participants completed a diary ten times a day during six to ten days. Multilevel analyses were used to model the time-lagged effects of daily stressful events on negative affect (NA) and paranoia symptoms to examine reactivity and recovery. Results: There was a significant difference in NA reactivity. VR-CBT showed higher NA at post-treatment compared to pre-treatment than WL (bpre=0.14; bpost=0.19 vs bpre=0.18; bpost=0.14). There was a significant difference in NA recovery and paranoia recovery between the groups at lag 1: VR-CBT showed relatively lower negative affect (bpre=0.07; bpost=-0.06) and paranoia (bpre= 0.08; bpost=-0.10) at post-treatment compared to pre-treatment than WL (bpre=0.08; bpost=0.08; bpre=0.04; bpost=0.03). Conclusion: Negative affect and paranoia recovery improved in response to treatment. Increased NA reactivity may be explained by a decrease in safety behavior in the VR-CBT group. The discrepancy between reactivity and recovery findings may be explained by the inhibitory learning theory that suggests that an original threat reaction may not erase but can be inhibited as a consequence of exposure therapy.
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To avoid delay in oncological treatment, a 6-weeks norm for time to treatment has been agreed on in The Netherlands. However, the impact of the COVID-19 pandemic on health systems resulted in reduced capacity for regular surgical care. In this study, we investigated the impact of the COVID-19 pandemic on time to treatment in surgical oncology in The Netherlands. METHODS: A population-based analysis of data derived from five surgical audits, including patients who underwent surgery for lung cancer, colorectal cancer, upper gastro-intestinal, and hepato-pancreato-biliary (HPB) malignancies, was performed. The COVID-19 cohort of 2020 was compared to the historic cohorts of 2018 and 2019. Primary endpoints were time to treatment initiation and the proportion of patients whose treatment started within 6 weeks. The secondary objective was to evaluate the differences in characteristics and tumour stage distribution between patients treated before and during the COVID-19 pandemic. RESULTS: A total of 14,567 surgical cancer patients were included in this study, of these 3292 treatments were started during the COVID-19 pandemic. The median time to treatment decreased during the pandemic (26 vs. 27 days, p < 0.001) and the proportion of patients whose treatment started within 6 weeks increased (76% vs. 73%, p < 0.001). In a multivariate logistic regression analysis, adjusting for patient characteristics, no significant difference in post-operative outcomes between patients who started treatment before or after 6 weeks was found. Overall, the number of procedures performed per week decreased by 8.1% during the pandemic. This reduction was most profound for patients with stage I lung carcinoma and colorectal carcinoma. There were fewer patients with pulmonary comorbidities in the pandemic cohort (11% vs. 13%, p = 0.003). CONCLUSIONS: Despite pressure on the capacity of the healthcare system during the COVID-19 pandemic, a larger proportion of surgical oncological patients started treatment within six weeks, possibly due to prioritisation of cancer care and reductions in elective procedures. However, during the pandemic, a decrease in the number of surgical oncological procedures performed in The Netherlands was observed, especially for patients with stage I disease.
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We investigate thermal and quantum phase transitions of the J_{1}-J_{2}-J_{3} transverse Ising model on the square lattice. The model is studied within a cluster mean-field decoupling, which allows us to describe phase diagrams and the free-energy landscape in the neighborhood of phase transitions. Our findings indicate that the third-neighbor coupling (J_{3}) can affect the nature of phase transitions of the model. In particular, ferromagnetic third-neighbor couplings favor the onset of continuous order-disorder phase transitions, eliminating the tricritical point of the superantiferromagnetic-paramagnetic (SAFM-PM) phase boundary. On the other hand, the enhancement of frustration introduced by weak antiferromagnetic J_{3} gives rise to the staggered dimer phase favoring the onset of discontinuous classical phase transitions. Moreover, we find that quantum annealed criticality (QAC), which takes place when the classical discontinuous phase transition becomes critical by the enhancement of quantum fluctuations introduced by the transverse magnetic field, is eliminated from the SAFM-PM phase boundary by a relatively weak ferromagnetic J_{3}. Nevertheless, this change in the nature of phase transitions can still be observed in the presence of antiferromagnetic third-neighbor couplings being also found in the staggered-dimer phase boundary. Therefore, our findings support that QAC persists under the presence of frustrated antiferromagnetic third-neighbor couplings and is suppressed when these couplings are ferromagnetic, suggesting that frustration plays a central role in the onset of QAC.
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Circulating sexual stages of Plasmodium falciparum (Pf) can be transmitted from humans to mosquitoes, thereby furthering the spread of malaria in the population. It is well established that antibodies (Abs) can efficiently block parasite transmission. In search for naturally acquired Ab targets on sexual stages, we established an efficient method for target-agnostic single B cell activation followed by high-throughput selection of human monoclonal antibodies (mAbs) reactive to sexual stages of Pf in the form of gamete and gametocyte extract. We isolated mAbs reactive against a range of Pf proteins including well-established targets Pfs48/45 and Pfs230. One mAb, B1E11K, was cross-reactive to various proteins containing glutamate-rich repetitive elements expressed at different stages of the parasite life cycle. A crystal structure of two B1E11K Fab domains in complex with its main antigen, RESA, expressed on asexual blood stages, showed binding of B1E11K to a repeating epitope motif in a head-to-head conformation engaging in affinity-matured homotypic interactions. Thus, this mode of recognition of Pf proteins, previously described only for PfCSP, extends to other repeats expressed across various stages. The findings augment our understanding of immune-pathogen interactions to repeating elements of the Plasmodium parasite proteome and underscore the potential of the novel mAb identification method used to provide new insights into the natural humoral immune response against Pf . Impact Statement: A naturally acquired human monoclonal antibody recognizes proteins expressed at different stages of the Plasmodium falciparum lifecycle through affinity-matured homotypic interactions with glutamate-rich repeats.
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Manganese is an attractive element for sustainable solutions. It is largely available in the earth's crust, making it ideal for cost-effective and large-scale applications. Especially MnO nanoparticles have recently received attention for applications in battery technology. However, manganese has many oxidation states that are energetically very similar, indicating that they may easily transform from one to the other. Herein, the reversible oxidation of MnO nanoparticles to Mn3 O4 studied with in situ transmission electron microscopy is shown. The oxygen sublattices of MnO and Mn3 O4 are found to be perfectly aligned, and an atomic mechanism where the transformation is facilitated by the migration of Mn cations on the shared O sublattice is proposed. Even when protected with an amorphous carbon layer, MnO particles are highly unstable and oxidize to Mn3 O4 in ethanol. The poor stability of MnO lacks discussion in many battery-related works, and strategies aimed at avoiding this should be developed.
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Malaria transmission-blocking vaccines (TBVs) aim to induce antibodies that block Plasmodium parasite development in the mosquito midgut, thus preventing mosquitoes from becoming infectious. While the Pro-domain and first of fourteen 6-Cysteine domains (Pro-D1) of the Plasmodium gamete surface protein Pfs230 are known targets of transmission-blocking antibodies, no studies to date have discovered other Pfs230 domains that are functional targets. Here, we show that a murine monoclonal antibody (mAb), 18F25.1, targets Pfs230 Domain 7. We generated a subclass-switched complement-fixing variant, mAb 18F25.2a, using a CRISPR/Cas9-based hybridoma engineering method. This subclass-switched mAb 18F25.2a induced lysis of female gametes in vitro. Importantly, mAb 18F25.2a potently reduced P. falciparum infection of Anopheles stephensi mosquitoes in a complement-dependent manner, as assessed by standard membrane feeding assays. Together, our data identify Pfs230 Domain 7 as target for transmission-blocking antibodies and provide a strong incentive to study domains outside Pfs230Pro-D1 as TBV candidates.
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Nanoscale forms of molybdenum trioxide have found widespread use in optoelectronic, sensing, and battery applications. Here, we investigate the thermal evolution of micrometer-sized molybdenum trioxide particles during in situ heating in vacuum using transmission electron microscopy and observed drastic structural and chemical changes that are strongly dependent on the heating rate. Rapid heating (flash heating) of MoO3 particles to a temperature of 600 °C resulted in large-scale formation of MoO2(001) nanosheets that were formed in a wide area around the reducing MoO3 particles, within a few minutes of time frame. In contrast, when heated more gently, the initially single-crystal MoO3 particles were reduced into hollow nanostructures with polycrystalline MoO2 shells. Using density functional theory calculations employing the DFT-D3 functional, the surface energy of MoO3(010) was calculated to be 0.187 J m-2, and the activation energy for exfoliation of the van der Waals bonded MoO3 (010) layers was calculated to be 0.478 J m-2. Ab initio molecular dynamics simulations show strong fluctuations in the distance between the (010) layers, where thermal vibrations lead to additional separations of up to 1.8 Å at 600 °C. This study shows efficient pathways for the generation of either MoO2 nanosheets or hollow MoO2 nanostructures with very high effective surface areas beneficial for applications.
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BACKGROUND AND OBJECTIVES: Recently, the US Food and Drug Administration approved the tau-binding radiotracer [18F]flortaucipir and an accompanying visual read method to support the diagnostic process in cognitively impaired patients assessed for Alzheimer disease (AD). Studies evaluating this visual read method are limited. In this study, we evaluated the performance of the visual read method in participants along the AD continuum and dementia with Lewy bodies (DLB) by determining its reliability, accordance with semiquantitative analyses, and associations with clinically relevant variables. METHODS: We included participants who underwent tau-PET at Amsterdam University Medical Center. A subset underwent follow-up tau-PET. Two trained nuclear medicine physicians visually assessed all scans. Inter-reader agreement was calculated using Cohen κ. To examine the concordance of visual read tau positivity with semiquantification, we defined standardized uptake value ratio (SUVr) positivity using different threshold approaches. To evaluate the prognostic value of tau-PET visual read, we performed linear mixed models with longitudinal Mini-Mental State Examination (MMSE). RESULTS: We included 263 participants (mean age 68.5 years, 45.6% female), including 147 cognitively unimpaired (CU) participants, 97 amyloid-positive participants with mild cognitive impairment or AD dementia (AD), and 19 participants with DLB. The visual read inter-reader agreement was excellent (κ = 0.95, CI 0.91-0.99). None of the amyloid-negative CU participants (0/92 [0%]) and 1 amyloid-negative participant with DLB (1/12 [8.3%]) were tau-positive. Among amyloid-positive participants, 13 CU participants (13/52 [25.0%]), 85 with AD (85/97 [87.6%]), and 3 with DLB (3/7 [42.9%]) were tau-positive. Two-year follow-up visual read status was identical to baseline. Tau-PET visual read corresponded strongly to SUVr status, with up to 90.4% concordance. Visual read tau positivity was associated with a decline on the MMSE in CU participants (ß = -0.52, CI -0.74 to -0.30, p < 0.001) and participants with AD (ß = -0.30, CI -0.58 to -0.02, p = 0.04). DISCUSSION: The excellent inter-reader agreement, strong correspondence with SUVr, and longitudinal stability indicate that the visual read method is reliable and robust, supporting clinical application. Furthermore, visual read tau positivity was associated with prospective cognitive decline, highlighting its additional prognostic potential. Future studies in unselected cohorts are needed for a better generalizability to the clinical population. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that [18F]flortaucipir visual read accurately distinguishes patients with low tau-tracer binding from those with high tau-tracer binding and is associated with amyloid positivity and cognitive decline.
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Enfermedad de Alzheimer , Disfunción Cognitiva , Enfermedad por Cuerpos de Lewy , Humanos , Femenino , Anciano , Masculino , Enfermedad de Alzheimer/metabolismo , Enfermedad por Cuerpos de Lewy/complicaciones , Estudios Prospectivos , Reproducibilidad de los Resultados , Proteínas tau/metabolismo , Péptidos beta-Amiloides/metabolismo , Tomografía de Emisión de Positrones/métodos , Disfunción Cognitiva/complicaciones , Amiloide/metabolismoRESUMEN
OBJECTIVES: Non-carious tooth wear often has a multifactorial etiology and may lead to functional or aesthetically related problems. The most common complaints associated with tooth wear are dissatisfaction with dental appearance and a negative impact on the experienced Oral Health Related Quality of Life (OHRQoL). The aim of this study was to investigate the change in OHRQoL and the perception of aesthetics, following restorative treatment of moderate to severe tooth wear patients, with a five-year follow-up. METHODS: An explorative study, based on prospective data, was performed. OHRQoL and the perception of aesthetics were measured with the OHIP-NL and OES-NL. These questionnaires were completed before treatment, one month after treatment, and at 1-, 3- and 5-years post-treatment. Treatment involved full mouth reconstruction with composite resin restorations. The data was analysed as repeated measures by using a linear mixed-effects model. RESULTS: One hundred and twenty-three tooth wear patients that received restorative rehabilitation were included (97 males, 26 females, 37.5 ± 8.8 years-old). Data showed a statistically significant increase in both experienced OHRQoL and orofacial appearance after restorative treatment. The OHIP-scores remained stable over time, while the OES-scores slightly decreased during the years after treatment. Regarding the seven domains of the OHIP, the largest difference in OHIP-score was found in the domain of 'Psychological Discomfort'. The mean overall OHIP-score was 1.8 at baseline and 1.3 at the 5-years recall. The mean OES score increased from 41.8 at baseline to 66.1 at the 5-years follow-up. CONCLUSIONS: Tooth wear patients reported significant improvements in their OHRQoL and their perception of orofacial aesthetics after restorative treatment. This increase remained at least five years post-treatment. CLINICAL SIGNIFICANCE: The clinical impact of restorative treatment for tooth wear patients is considerable. This paper emphasizes the need to include a discussion of the patient related outcome measures when planning care.
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Atrición Dental , Desgaste de los Dientes , Masculino , Femenino , Humanos , Adulto , Persona de Mediana Edad , Estudios de Seguimiento , Calidad de Vida , Estudios Prospectivos , Estética Dental , Desgaste de los Dientes/rehabilitación , Encuestas y Cuestionarios , Percepción , Salud BucalRESUMEN
BACKGROUND: Primary antibody deficiencies (PAD) are characterized by a heterogeneous clinical presentation and low prevalence, contributing to a median diagnostic delay of 3-10 years. This increases the risk of morbidity and mortality from undiagnosed PAD, which may be prevented with adequate therapy. To reduce the diagnostic delay of PAD, we developed a screening algorithm using primary care electronic health record (EHR) data to identify patients at risk of PAD. This screening algorithm can be used as an aid to notify general practitioners when further laboratory evaluation of immunoglobulins should be considered, thereby facilitating a timely diagnosis of PAD. METHODS: Candidate components for the algorithm were based on a broad range of presenting signs and symptoms of PAD that are available in primary care EHRs. The decision on inclusion and weight of the components in the algorithm was based on the prevalence of these components among PAD patients and control groups, as well as clinical rationale. RESULTS: We analyzed the primary care EHRs of 30 PAD patients, 26 primary care immunodeficiency patients and 58,223 control patients. The median diagnostic delay of PAD patients was 9.5 years. Several candidate components showed a clear difference in prevalence between PAD patients and controls, most notably the mean number of antibiotic prescriptions in the 4 years prior to diagnosis (5.14 vs. 0.48). The final algorithm included antibiotic prescriptions, diagnostic codes for respiratory tract and other infections, gastro-intestinal complaints, auto-immune symptoms, malignancies and lymphoproliferative symptoms, as well as laboratory values and visits to the general practitioner. CONCLUSIONS: In this study, we developed a screening algorithm based on a broad range of presenting signs and symptoms of PAD, which is suitable to implement in primary care. It has the potential to considerably reduce diagnostic delay in PAD, and will be validated in a prospective study. Trial registration The consecutive prospective study is registered at clinicaltrials.gov under NCT05310604.
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Patients with more severe forms of tooth wear may require restorative rehabilitation. The decision to commence treatment must be taken carefully and there are a multitude of factors to consider. Alongside the clinical signs and symptoms typically associated with tooth wear, there is also the need to assess the impact of the condition on the patient's oral health-related quality of life. As part of the discussions relating to the attainment of informed consent for the restoration of the worn dentition, not only is it relevant to appropriately appraise the risks, benefits, costs, reasonable alternatives and likely prognosis of the proposed treatments, but to also elaborate on the expected impact of the intervention on the patient's oral health-related quality of life. The aim of this article is to review the evidence relating to the impact of the quality of life with the management of tooth wear, with the introduction of the concept of an evidence-based approach to decision-making when planning care.
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Atrición Dental , Desgaste de los Dientes , Humanos , Calidad de Vida , Desgaste de los Dientes/terapia , Desgaste de los Dientes/diagnóstico , Consentimiento InformadoRESUMEN
PURPOSE: Tau pathology is associated with concurrent atrophy and decreased cerebral blood flow (CBF) in Alzheimer's disease (AD), but less is known about their temporal relationships. Our aim was therefore to investigate the association of concurrent and longitudinal tau PET with longitudinal changes in atrophy and relative CBF. METHODS: We included 61 individuals from the Amsterdam Dementia Cohort (mean age 65.1 ± 7.5 years, 44% female, 57% amyloid-ß positive [Aß +], 26 cognitively impaired [CI]) who underwent dynamic [18F]flortaucipir PET and structural MRI at baseline and 25 ± 5 months follow-up. In addition, we included 86 individuals (68 CI) who only underwent baseline dynamic [18F]flortaucipir PET and MRI scans to increase power in our statistical models. We obtained [18F]flortaucipir PET binding potential (BPND) and R1 values reflecting tau load and relative CBF, respectively, and computed cortical thickness from the structural MRI scans using FreeSurfer. We assessed the regional associations between i) baseline and ii) annual change in tau PET BPND in Braak I, III/IV, and V/VI regions and cortical thickness or R1 in cortical gray matter regions (spanning the whole brain) over time using linear mixed models with random intercepts adjusted for age, sex, time between baseline and follow-up assessments, and baseline BPND in case of analyses with annual change as determinant. All analyses were performed in Aß- cognitively normal (CN) individuals and Aß+ (CN and CI) individuals separately. RESULTS: In Aß+ individuals, greater baseline Braak III/IV and V/VI tau PET binding was associated with faster cortical thinning in primarily frontotemporal regions. Annual changes in tau PET were not associated with cortical thinning over time in either Aß+ or Aß- individuals. Baseline tau PET was not associated with longitudinal changes in relative CBF, but increases in Braak III/IV tau PET over time were associated with increases in parietal relative CBF over time in Aß + individuals. CONCLUSION: We showed that higher tau load was related to accelerated cortical thinning, but not to decreases in relative CBF. Moreover, tau PET load at baseline was a stronger predictor of cortical thinning than change of tau PET signal.
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Enfermedad de Alzheimer , Disfunción Cognitiva , Humanos , Femenino , Persona de Mediana Edad , Anciano , Masculino , Proteínas tau/metabolismo , Adelgazamiento de la Corteza Cerebral , Tomografía de Emisión de Positrones , Enfermedad de Alzheimer/metabolismo , Péptidos beta-Amiloides/metabolismo , Atrofia/diagnóstico por imagen , Circulación Cerebrovascular , Disfunción Cognitiva/metabolismoRESUMEN
The amyloid cascade hypothesis has strongly impacted the Alzheimer's disease research agenda and clinical trial designs over the past decades, but precisely how amyloid-ß pathology initiates the aggregation of neocortical tau remains unclear. We cannot exclude the possibility of a shared upstream process driving both amyloid-ß and tau in an independent manner instead of there being a causal relationship between amyloid-ß and tau. Here, we tested the premise that if a causal relationship exists, then exposure should be associated with outcome both at the individual level as well as within identical twin-pairs, who are strongly matched on genetic, demographic and shared environmental background. Specifically, we tested associations between longitudinal amyloid-ß PET and cross-sectional tau PET, neurodegeneration and cognitive decline using genetically identical twin-pair difference models, which provide the unique opportunity of ruling out genetic and shared environmental effects as potential confounders in an association. We included 78 cognitively unimpaired identical twins with [18F]flutemetamol (amyloid-ß)-PET, [18F]flortaucipir (tau)-PET, MRI (hippocampal volume) and cognitive data (composite memory). Associations between each modality were tested at the individual level using generalized estimating equation models, and within identical twin-pairs using within-pair difference models. Mediation analyses were performed to test for directionality in the associations as suggested by the amyloid cascade hypothesis. At the individual level, we observed moderate-to-strong associations between amyloid-ß, tau, neurodegeneration and cognition. The within-pair difference models replicated results observed at the individual level with comparably strong effect sizes. Within-pair differences in amyloid-ß were strongly associated with within-pair differences in tau (ß = 0.68, P < 0.001), and moderately associated with within-pair differences in hippocampal volume (ß = -0.37, P = 0.03) and memory functioning (ß = -0.57, P < 0.001). Within-pair differences in tau were moderately associated with within-pair differences in hippocampal volume (ß = -0.53, P < 0.001) and strongly associated with within-pair differences in memory functioning (ß = -0.68, P < 0.001). Mediation analyses showed that of the total twin-difference effect of amyloid-ß on memory functioning, the proportion mediated through pathways including tau and hippocampal volume was 69.9%, which was largely attributable to the pathway leading from amyloid-ß to tau to memory functioning (proportion mediated, 51.6%). Our results indicate that associations between amyloid-ß, tau, neurodegeneration and cognition are unbiased by (genetic) confounding. Furthermore, effects of amyloid-ß on neurodegeneration and cognitive decline were fully mediated by tau. These novel findings in this unique sample of identical twins are compatible with the amyloid cascade hypothesis and thereby provide important new knowledge for clinical trial designs.
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Enfermedad de Alzheimer , Disfunción Cognitiva , Humanos , Gemelos Monocigóticos/genética , Proteínas tau/genética , Proteínas tau/metabolismo , Estudios Transversales , Tomografía de Emisión de Positrones/métodos , Enfermedad de Alzheimer/diagnóstico por imagen , Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/metabolismo , Amiloide/metabolismo , Proteínas Amiloidogénicas , Disfunción Cognitiva/diagnóstico por imagen , Disfunción Cognitiva/genética , Disfunción Cognitiva/metabolismo , Péptidos beta-Amiloides/metabolismoRESUMEN
Malaria transmission-blocking vaccines (TBVs) aim to induce antibodies that interrupt malaria parasite development in the mosquito, thereby blocking onward transmission, and provide a much-needed tool for malaria control and elimination. The parasite surface protein Pfs48/45 is a leading TBV candidate. Here, we isolated and characterized a panel of 81 human Pfs48/45-specific monoclonal antibodies (mAbs) from donors naturally exposed to Plasmodium parasites. Genetically diverse mAbs against each of the three domains (D1-D3) of Pfs48/45 were identified. The most potent mAbs targeted D1 and D3 and achieved >80% transmission-reducing activity in standard membrane-feeding assays, at 10 and 2 µg/mL, respectively. Co-crystal structures of D3 in complex with four different mAbs delineated two conserved protective epitopes. Altogether, these Pfs48/45-specific human mAbs provide important insight into protective and non-protective epitopes that can further our understanding of transmission and inform the design of refined malaria transmission-blocking vaccine candidates.
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Culicidae , Vacunas contra la Malaria , Malaria Falciparum , Malaria , Animales , Humanos , Plasmodium falciparum , Culicidae/metabolismo , Proteínas Protozoarias , Anticuerpos Monoclonales , Malaria Falciparum/prevención & control , Anticuerpos AntiprotozoariosRESUMEN
Infertility affects around 7% of the male population and can be due to severe spermatogenic failure (SPGF), resulting in no or very few sperm in the ejaculate. We initially identified a homozygous frameshift variant in FKBP6 in a man with extreme oligozoospermia. Subsequently, we screened a total of 2,699 men with SPGF and detected rare bi-allelic loss-of-function variants in FKBP6 in five additional persons. All six individuals had no or extremely few sperm in the ejaculate, which were not suitable for medically assisted reproduction. Evaluation of testicular tissue revealed an arrest at the stage of round spermatids. Lack of FKBP6 expression in the testis was confirmed by RT-qPCR and immunofluorescence staining. In mice, Fkbp6 is essential for spermatogenesis and has been described as being involved in piRNA biogenesis and formation of the synaptonemal complex (SC). We did not detect FKBP6 as part of the SC in normal human spermatocytes, but small RNA sequencing revealed that loss of FKBP6 severely impacted piRNA levels, supporting a role for FKBP6 in piRNA biogenesis in humans. In contrast to findings in piRNA-pathway mouse models, we did not detect an increase in LINE-1 expression in men with pathogenic FKBP6 variants. Based on our findings, FKBP6 reaches a "strong" level of evidence for being associated with male infertility according to the ClinGen criteria, making it directly applicable for clinical diagnostics. This will improve patient care by providing a causal diagnosis and will help to predict chances for successful surgical sperm retrieval.
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Azoospermia , Infertilidad Masculina , Animales , Azoospermia/genética , Humanos , Infertilidad Masculina/genética , Elementos de Nucleótido Esparcido Largo , Masculino , Ratones , ARN Interferente Pequeño/metabolismo , Semen , Espermatogénesis/genética , Proteínas de Unión a Tacrolimus/genética , Proteínas de Unión a Tacrolimus/metabolismo , Testículo/patologíaRESUMEN
Individuals infected with P. falciparum develop antibody responses to intra-erythrocytic gametocyte proteins and exported gametocyte proteins present on the surface of infected erythrocytes. However, there is currently limited knowledge on the immunogenicity of gametocyte antigens and the specificity of gametocyte-induced antibody responses. In this study, we assessed antibody responses in participants of two controlled human malaria infection (CHMI) studies by ELISA, multiplexed bead-based antibody assays and protein microarray. By comparing antibody responses in participants with and without gametocyte exposure, we aimed to disentangle the antibody response induced by asexual and sexual stage parasites. We showed that after a single malaria infection, a significant anti-sexual stage humoral response is induced in malaria-naïve individuals, even after exposure to relatively low gametocyte densities (up to ~1,600 gametocytes/mL). In contrast to antibody responses to well-characterised asexual blood stage antigens that were detectable by day 21 after infection, responses to sexual stage antigens (including transmission blocking vaccine candidates Pfs48/45 and Pfs230) were only apparent at 51 days after infection. We found antigens previously associated with early gametocyte or anti-gamete immunity were highly represented among responses linked with gametocyte exposure. Our data provide detailed insights on the induction and kinetics of antibody responses to gametocytes and identify novel antigens that elicit antibody responses exclusively in individuals with gametocyte exposure. Our findings provide target identification for serological assays for surveillance of the malaria infectious reservoir, and support vaccine development by describing the antibody response to leading vaccine antigens after primary infection.
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Malaria Falciparum , Malaria , Anticuerpos Antiprotozoarios , Humanos , Inmunidad Humoral , Plasmodium falciparumRESUMEN
Objective: To assess adherence to statin therapy and its association with sociodemographic data, medical characteristics, LDLc levels, and LDLc target attainment in real-world T2D patients treated in secondary care. Research Design and Methods: Cross-sectional analyses were performed on baseline data of 393 patients in the DIAbetes and LifEstyle Cohort Twente (DIALECT). The medication possession ratio (MPR), calculated with pharmacy dispensing data, was used to determine adherence to statins for an intended period of 24 months. Statins were included in the analyses if they were used for at least six consecutive months with at least three dispenses. Adherence was defined as an MPR ≥80%. Associations with adherence were assessed using descriptive statistics and binary logistic regression. Results: Overall, 80% of the patients had a statin prescription and of those, 89% were adherent. The proportion of patients who reached LDLc targets of ≤2.5 mmol/L and <1.8 mmol/L differed significantly between the adherent, nonadherent and non-statin group (90% vs. 74% vs. 46%; p < 0.01 and 56% vs. 26% vs. 6%; p < 0.01, respectively). Serum LDLc levels were lower in the adherent versus the nonadherent and non-statin group (1.76 ± 0.60 vs. 2.23 ± 0.90 vs. 2.71 ± 0.67 mmol/L; p < 0.01). Higher HbA1c levels were independently associated with nonadherence (OR: 1.05, 95% CI 1.01-1.08; p < 0.01). Mediation adherence (OR: 2.88, 95% CI 1.04-7.97; p = 0.041) and lower BMI (OR: 0.88, 95% CI 0.81-0.96; p < 0.01) were independently associated with attaining the LDLc target of ≤2.5 mmol/L. Conclusion: In patients with T2D treated in secondary care, statin adherence was relatively high and was associated with significantly lower LDLc levels. It is important to identify nonadherence as it appeared an important determinant of failure to reach LDLc targets. The finding that many patients who failed to attain LDLc targets did not receive statin treatment offers an opportunity to improve diabetes care.
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Malaria transmission blocking vaccines (TBV) aim to induce antibodies that can interrupt Plasmodium falciparum development in the mosquito midgut and thereby prevent onward malaria transmission. A limited number of TBV candidates have been identified and only three (Pfs25, Pfs230 and Pfs48/45) have entered clinical testing. While one of these candidates may emerge as a highly potent TBV candidate, it is premature to determine if they will generate sufficiently potent and sustained responses. It is therefore important to explore novel candidate antigens. We recently analyzed sera from naturally exposed individuals and found that the presence and/or intensity of antibodies against 12 novel putative surface expressed gametocyte antigens was associated with transmission reducing activity. In this study, protein fragments of these novel TBV candidates were designed and heterologously expressed in Drosophila melanogaster S2 cells and Lactococcus lactis. Eleven protein fragments, covering seven TBV candidates, were successfully produced. All tested antigens were recognized by antibodies from individuals living in malaria-endemic areas, indicating that native epitopes are present. All antigens induced antigen-specific antibody responses in mice. Two antigens induced antibodies that recognized a native protein in gametocyte extract, and antibodies elicited by four antigens recognized whole gametocytes. In particular, we found that antigen Pf3D7_0305300, a putative transporter, is abundantly expressed on the surface of gametocytes. However, none of the seven novel TBV candidates expressed here induced an antibody response that reduced parasite development in the mosquito midgut as assessed in the standard membrane feeding assay. Altogether, the antigen fragments used in this study did not prove to be promising transmission blocking vaccine constructs, but led to the identification of two gametocyte surface proteins that may provide new leads for studying gametocyte biology.