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Microbeam Radiation Therapy opens a several days vessel permeability window for small molecules in brain tumor vessels.
No full textPURPOSE
Synchrotron microbeam radiation therapy (MRT), based on an inhomogeneous geometric and microscopic irradiation pattern of the tissues with high dose and high dose rate X-rays, enhances the permeability of brain tumor vessels. This study attempts to determine time and size range of the permeability window induced by MRT in the blood brain (tumor) barrier.
METHODS AND MATERIALS
Rats-bearing 9L gliomas were exposed to MRT, either unidirectional (tumor dose 406 Gy), or bidirectional (crossfired) (2 × 203 Gy). We measured vessel permeability to molecules of 3 sizes (Gd-DOTA, Dotarem®, 0.56 kDa; gadolinium-labeled albumin, ∼74 kDa; gadolinium-labeled IgG, 160 kDa) by daily in vivo magnetic resonance imaging (MRI), from 1 day before to 10 days post-irradiation.
RESULTS
An equivalent tumor dose of bidirectional MRT delivered from two orthogonal directions increased tumor vessel permeability for the smallest molecule tested more effectively than unidirectional MRT. Bidirectional MRT also affected the permeability of normal contralateral vessels to a different extent than unidirectional MRT. Conversely, bidirectional MRT did not modify the permeability of normal or tumor vessels for both larger molecules (74 and 160 kDa).
CONCLUSIONS
High-dose bidirectional (cross-fired) MRT induced a significant increase in tumor vessel permeability for small molecules between the first and the seventh day after irradiation, while permeability of vessels in normal brain tissue remained stable. Such a permeability window could facilitate an efficient and safe delivery of intravenous small molecules (≤0.56 kDa) to tumoral tissues. A permeability window was not achieved by molecules larger than gado-grafted albumin (74 kDa). Vascular permeability for molecules between these two sizes has not been determined
Seizure Cycles under Pharmacotherapy.
No full textOBJECTIVE
This study was undertaken to determine the effects of antiseizure medications (ASMs) on multidien (multiday) cycles of interictal epileptiform activity (IEA) and seizures and evaluate their potential clinical significance.
METHODS
We retrospectively analyzed up to 10 years of data from 88 of the 256 total adults with pharmacoresistant focal epilepsy who participated in the clinical trials of the RNS System, an intracranial device that keeps records of IEA counts. Following adjunctive ASM trials, we evaluated changes over months in (1) rates of self-reported disabling seizures and (2) multidien IEA cycle strength (spectral power for periodicity between 4 and 40 days). We used a survival analysis and the receiver operating characteristics to assess changes in IEA as a predictor of seizure control.
RESULTS
Among 56 (33.3%) of the 168 adjunctive ASM trials suitable for analysis, ASM introduction was followed by an average 50 to 70% decrease in multidien IEA cycle strength and a concomitant 50 to 70% decrease in relative seizure rate for up to 12 months. Individuals with a ≥50% decrease in IEA cycle strength in the first 3 months of an ASM trial had a higher probability of remaining seizure responders (≥50% seizure rate reduction, p < 10-7 ) or super-responders (≥90%, p < 10-8 ) over the next 12 months.
INTERPRETATION
In this large cohort, a decrease in multidien IEA cycle strength following initiation of an adjunctive ASM correlated with seizure control for up to 12 months, suggesting that fluctuations in IEA mirror "disease activity" in pharmacoresistant focal epilepsy and may have clinical utility as a biomarker to predict treatment response. ANN NEUROL 2024
Influence of RNA circularity on Target RNA-Directed MicroRNA Degradation.
No full textA subset of circular RNAs (circRNAs) and linear RNAs have been proposed to 'sponge' or block microRNA activity. Additionally, certain RNAs induce microRNA destruction through the process of Target RNA-Directed MicroRNA Degradation (TDMD), but whether both linear and circular transcripts are equivalent in driving TDMD is unknown. Here, we studied whether circular/linear topology of endogenous and artificial RNA targets affects TDMD. Consistent with previous knowledge that Cdr1as (ciRS-7) circular RNA protects miR-7 from Cyrano-mediated TDMD, we demonstrate that depletion of Cdr1as reduces miR-7 abundance. In contrast, overexpression of an artificial linear version of Cdr1as drives miR-7 degradation. Using plasmids that express a circRNA with minimal co-expressed cognate linear RNA, we show differential effects on TDMD that cannot be attributed to the nucleotide sequence, as the TDMD properties of a sequence often differ when in a circular versus linear form. By analysing RNA sequencing data of a neuron differentiation system, we further detect potential effects of circRNAs on microRNA stability. Our results support the view that RNA circularity influences TDMD, either enhancing or inhibiting it on specific microRNAs
DFL: Dynamic Federated Split Learning in Heterogeneous IoT
Get PDFFederated Learning (FL) in edge Internet of Things (IoT) environments is challenging due to the heterogeneous nature of the learning environment, mainly embodied in two aspects. Firstly, the statistically heterogeneous data, usually non-independent identically distributed (non-IID), from geographically distributed clients can deteriorate the FL training accuracy. Secondly, the heterogeneous computing and communication resources in IoT devices often result in unstable training processes that slow down the training of a global model and affect energy consumption. Most existing solutions address only the unilateral side of the heterogeneity issue but neglect the joint problem of resources and data heterogeneity for the resource-constrained IoT. In this article, we propose Dynamic Federated split Learning (DFL) to address the joint problem of data and resource heterogeneity for distributed training in IoT. DFL enhances training efficiency in heterogeneous dynamic IoT through resource-aware split computing of deep neural networks and dynamic clustering of training participants based on the similarity of their sub-model layers. We evaluate DFL on a real testbed comprising heterogeneous IoT devices using two widely-adopted datasets, in various non-IID settings. Results show that DFL improves training performance in terms of training time by up to 48%, accuracy by up to 32%, and energy consumption by up to 62.8% compared to classic FL and Federated Split Learning in scenarios with both data and resource heterogeneity
Nogo-A neutralization in the central nervous system with a blood-brain barrier-penetrating antibody.
No full textThe poor penetration of monoclonal antibodies (mAb) across the blood-brain barrier (BBB) impedes the development of regenerative therapies for neurological diseases. For example, Nogo-A is a myelin-associated protein highly expressed in the central nervous system (CNS) whose inhibitory effects on neuronal plasticity can be neutralized with direct administration of 11C7 mAb in CNS tissues/fluids, but not with peripheral administrations such as intravenous injections. Therefore, in the present study, we engineered a CNS-penetrating antibody against Nogo-A by combining 11C7 mAb and the single-chain variable fragment (scFv) of 8D3, a rat antibody binding transferrin receptor 1 (TfR) and mediating BBB transcytosis (11C7-scFv8D3). The binding of 11C7-scFv8D3 to Nogo-A and to TfR/CD71 was validated by capture ELISA and Biolayer Interferometry. After intravenous injection in mice, capture ELISA measurements revealed fast plasma clearance of 11C7-scFv8D3 concomitantly with brain and spinal cord accumulation at levels up to 19 fold as high as those of original 11C7 mAb. 11C7-scFv8D3 detection in the parenchyma indicated effective blood-to-CNS transfer. A single dose of 11C7-scFv8D3 induced stronger activation of the growth-promoting AkT/mTOR/S6 signaling pathway than 11C7 mAb or control antibody. Taken together, our results show that BBB-crossing 11C7-scFv8D3 engages Nogo-A in the mouse CNS and stimulates neuronal growth mechanisms
Characteristics, Prevalence, and Clinical Relevance of Juxtacortical Paramagnetic Rims in Patients With Multiple Sclerosis.
No full textBACKGROUND AND OBJECTIVES
A subgroup of patients with multiple sclerosis (MS) presents focal paramagnetic rims at the border between cortex and white matter (juxtacortical paramagnetic rims [JPRs]). We investigated the presence of this finding in our in vivo MS cohort and explored its potential clinical relevance. Moreover, we exploited postmortem MRI of fixed whole MS brains to (1) detect those rims and (2) investigate their histologic correlation.
METHODS
Quantitative susceptibility mapping (QSM) and magnetization-prepared 2 rapid acquisition gradient-echo (MP2RAGE) images at 3T-MRI of 165 patients with MS from the in vivo cohort were screened for JPRs and the presence of cortical lesions. Five postmortem brains from patients with MS were imaged with 3T-MRI to obtain QSM and MP2RAGE sequences. Tissue blocks containing JPRs were excised and paraffin-embedded slices stained by immunohistochemistry for myelin basic protein (for myelin) and anti-CR3/43 (for major histocompatibility complex II-positive microglia/macrophages). DAB-Turnbull stain was performed to detect iron.
RESULTS
JPRs are present in approximately 10% of in vivo patients and are associated with increased cortical lesion load. One of the 5 postmortem brains showed JPRs. Histologically, JPRs correspond to an accumulation of activated iron-laden phagocytes and are associated with demyelination of the whole overlying cortical ribbon.
DISCUSSION
JPRs are a novel potential MRI biomarker of focal cortical demyelination, which seems related to global cortical pathology and might be useful for diagnostic and stratification purposes in a clinical setting
The art of hijacking: how Nsp1 impacts host gene expression during coronaviral infections.
Get PDFNon-structural protein 1 (Nsp1) is one of the first proteins produced during coronaviral infections. It plays a pivotal role in hijacking and rendering the host gene expression under the service of the virus. With a focus on SARS-CoV-2, this review presents how Nsp1 selectively inhibits host protein synthesis and induces mRNA degradation of host but not viral mRNAs and blocks nuclear mRNA export. The clinical implications of this protein are highlighted by showcasing the pathogenic role of Nsp1 through the repression of interferon expression pathways and the features of viral variants with mutations in the Nsp1 coding sequence. The ability of SARS-CoV-2 Nsp1 to hinder host immune responses at an early step, the absence of homology to any human proteins, and the availability of structural information render this viral protein an ideal drug target with therapeutic potential
Geographies of Food: Global visions of healthy and unhealthy food
No full textThe book offers a multi-scale, epistemically diverse, and sense-making perspectives on the food system. The book argues that sustainable food system transformation is a complex proposition that can better thrive upon the inclusion of consumer perspectives. The book brings together scholarly works of scholars and practitioners who bring to bear the uniqueness of places, cultures, histories and interactions in the milieu of food
Optimistic vs Pessimistic Message Framing in Communicating Prognosis to Parents of Very Preterm Infants: The COPE Randomized Clinical Trial.
Get PDFIMPORTANCE
In the neonatal intensive care unit, there is a lack of understanding about how best to communicate the prognosis of a serious complication to parents.
OBJECTIVE
To examine parental preferences and the effects of optimistic vs pessimistic message framing when providing prognostic information about a serious complication.
DESIGN, SETTING, AND PARTICIPANTS
This crossover randomized clinical trial was conducted at a single German university medical center between June and October 2021. Eligible participants were parents of surviving preterm infants with a birth weight under 1500 g. Data were analyzed between October 2021 and August 2022.
INTERVENTIONS
Alternating exposure to 2 scripted video vignettes showing a standardized conversation between a neonatologist and parents, portrayed by professional actors, about the prognosis of a hypothetical very preterm infant with severe intraventricular hemorrhage. The video vignettes differed in the framing of identical numerical outcome estimates as either probability of survival and probability of nonimpairment (optimistic framing) or a risk of death and impaired survival (pessimistic framing).
MAIN OUTCOMES AND MEASURES
The primary outcome was preference odds (ratio of preference for optimistic vs pessimistic framing). Secondary outcomes included state anxiety, perceptions of communication, and recall of numerical estimates.
RESULTS
Of 220 enrolled parents (142 [64.5%] mothers; mean [SD] age: mothers, 39.1 [5.6] years; fathers, 42.7 [6.9] years), 196 (89.1%) preferred optimistic and 24 (10.1%) preferred pessimistic framing (preference odds, 11.0; 95% CI, 6.28-19.10; P < .001). Preference for optimistic framing was more pronounced when presented second than when presented first (preference odds, 5.41; 95% CI, 1.77-16.48; P = .003). State anxiety scores were similar in both groups at baseline (mean difference, -0.34; -1.18 to 0.49; P = .42) and increased equally after the first video (mean difference, -0.55; 95% CI, -1.79 to 0.69; P = .39). After the second video, state anxiety scores decreased when optimistic framing followed pessimistic framing but remained unchanged when pessimistic framing followed optimistic framing (mean difference, 2.15; 95% CI, 0.91 to 3.39; P < .001). With optimistic framing, participants recalled numerical estimates more accurately for survival (odds ratio, 4.00; 95% CI, 1.64-9.79; P = .002) but not for impairment (odds ratio, 1.50; 95% CI, 0.85-2.63; P = .16).
CONCLUSIONS AND RELEVANCE
When given prognostic information about a serious complication, parents of very preterm infants may prefer optimistic framing. Optimistic framing may lead to more realistic expectations for survival, but not for impairment.
TRIAL REGISTRATION
German Clinical Trials Register (DRKS): DRKS00024466
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