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International Journal of Molecular... May 2024Astronauts on exploratory missions will be exposed to galactic cosmic rays (GCR), which can induce neuroinflammation and oxidative stress (OS) and may increase the risk...
Astronauts on exploratory missions will be exposed to galactic cosmic rays (GCR), which can induce neuroinflammation and oxidative stress (OS) and may increase the risk of neurodegenerative disease. As key regulators of inflammation and OS in the CNS, microglial cells may be involved in GCR-induced deficits, and therefore could be a target for neuroprotection. This study assessed the effects of exposure to helium (He) and iron (Fe) particles on inflammation and OS in microglia in vitro, to establish a model for testing countermeasure efficacy. Rat microglia were exposed to a single dose of 20 cGy (300 MeV/n) He or 2 Gy Fe (600 MeV/n), while the control cells were not exposed (0 cGy). Immediately following irradiation, fresh media was applied to the cells, and biomarkers of inflammation (cyclooxygenase-2 [COX-2], nitric oxide synthase [iNOS], phosphorylated IκB-α [pIκB-α], tumor necrosis factor-α [TNFα], and nitrite [NO]) and OS (NADPH oxidase [NOX2]) were assessed 24 h later using standard immunochemical techniques. Results showed that radiation did not increase levels of NO or protein levels of COX-2, iNOS, pIκB-α, TNFα, or NOX2 compared to non-irradiated control conditions in microglial cells ( > 0.05). Therefore, microglia in isolation may not be the primary cause of neuroinflammation and OS following exposures to helium or iron GCR particles.
Topics: Animals; Microglia; Cosmic Radiation; Oxidative Stress; Rats; Inflammation; Biomarkers; Nitric Oxide Synthase Type II; Iron; Cyclooxygenase 2; Helium; Tumor Necrosis Factor-alpha; NADPH Oxidase 2
PubMed: 38892109
DOI: 10.3390/ijms25115923 -
International Journal of Molecular... May 2024Astatine (At) is a cyclotron-produced alpha emitter with a physical half-life of 7.2 h. In our previous study, the At-labeled prostate-specific membrane antigen (PSMA)...
Astatine (At) is a cyclotron-produced alpha emitter with a physical half-life of 7.2 h. In our previous study, the At-labeled prostate-specific membrane antigen (PSMA) compound ([At]PSMA-5) exhibited excellent tumor growth suppression in a xenograft model. We conducted preclinical biodistribution and toxicity studies for the first-in-human clinical trial. [At]PSMA-5 was administered to both normal male ICR mice ( = 85) and cynomolgus monkeys ( = 2). The mice were divided into four groups for the toxicity study: 5 MBq/kg, 12 MBq/kg, 35 MBq/kg, and vehicle control, with follow-ups at 1 day ( = 10 per group) and 14 days ( = 5 per group). Monkeys were observed 24 h post-administration of [At]PSMA-5 (9 MBq/kg). Blood tests and histopathological examinations were performed at the end of the observation period. Blood tests in mice indicated no significant myelosuppression or renal dysfunction. However, the monkeys displayed mild leukopenia 24 h post-administration. Despite the high accumulation in the kidneys and thyroid, histological analysis revealed no abnormalities. On day 1, dose-dependent single-cell necrosis/apoptosis was observed in the salivary glands of mice and intestinal tracts of both mice and monkeys. Additionally, tingible body macrophages in the spleen and lymph nodes indicated phagocytosis of apoptotic B lymphocytes. Cortical lymphopenia (2/10) in the thymus and a decrease in the bone marrow cells (9/10) were observed in the 35 MBq/kg group in mice. These changes were transient, with no irreversible toxicity observed in mice 14 days post-administration. This study identified no severe toxicities associated with [At]PSMA-5, highlighting its potential as a next-generation targeted alpha therapy for prostate cancer. The sustainable production of At using a cyclotron supports its applicability for clinical use.
Topics: Animals; Male; Prostatic Neoplasms; Mice; Tissue Distribution; Mice, Inbred ICR; Astatine; Alpha Particles; Humans; Macaca fascicularis; Glutamate Carboxypeptidase II; Radiopharmaceuticals
PubMed: 38891856
DOI: 10.3390/ijms25115667 -
Journal of Translational Medicine Jun 2024This study developed a nomogram model using CT-based delta-radiomics features and clinical factors to predict pathological complete response (pCR) in esophageal squamous...
BACKGROUND
This study developed a nomogram model using CT-based delta-radiomics features and clinical factors to predict pathological complete response (pCR) in esophageal squamous cell carcinoma (ESCC) patients receiving neoadjuvant chemoradiotherapy (nCRT).
METHODS
The study retrospectively analyzed 232 ESCC patients who underwent pretreatment and post-treatment CT scans. Patients were divided into training (n = 186) and validation (n = 46) sets through fivefold cross-validation. 837 radiomics features were extracted from regions of interest (ROIs) delineations on CT images before and after nCRT to calculate delta values. The LASSO algorithm selected delta-radiomics features (DRF) based on classification performance. Logistic regression constructed a nomogram incorporating DRFs and clinical factors. Receiver operating characteristic (ROC) and area under the curve (AUC) analyses evaluated nomogram performance for predicting pCR.
RESULTS
No significant differences existed between the training and validation datasets. The 4-feature delta-radiomics signature (DRS) demonstrated good predictive accuracy for pCR, with α-binormal-based and empirical AUCs of 0.871 and 0.869. T-stage (p = 0.001) and differentiation degree (p = 0.018) were independent predictors of pCR. The nomogram combined the DRS and clinical factors improved the classification performance in the training dataset (AUC = 0.933 and AUC = 0.941). The validation set showed similar performance with AUCs of 0.958 and 0.962.
CONCLUSIONS
The CT-based delta-radiomics nomogram model with clinical factors provided high predictive accuracy for pCR in ESCC patients after nCRT.
Topics: Humans; Nomograms; Male; Female; Middle Aged; Neoadjuvant Therapy; Esophageal Squamous Cell Carcinoma; Esophageal Neoplasms; Tomography, X-Ray Computed; Chemoradiotherapy; ROC Curve; Treatment Outcome; Aged; Carcinoma, Squamous Cell; Reproducibility of Results; Adult; Area Under Curve; Retrospective Studies; Radiomics
PubMed: 38890720
DOI: 10.1186/s12967-024-05392-4 -
Cell Death & Disease Jun 2024Radiation therapy (RT) remains a common treatment for cancer patients worldwide, despite the development of targeted biological compounds and immunotherapeutic drugs....
Radiation therapy (RT) remains a common treatment for cancer patients worldwide, despite the development of targeted biological compounds and immunotherapeutic drugs. The challenge in RT lies in delivering a lethal dose to the cancerous site while sparing the surrounding healthy tissues. Low linear energy transfer (low-LET) and high linear energy transfer (high-LET) radiations have distinct effects on cells. High-LET radiation, such as alpha particles, induces clustered DNA double-strand breaks (DSBs), potentially inducing cell death more effectively. However, due to limited range, alpha-particle therapies have been restricted. In human cancer, mutations in TP53 (encoding for the p53 tumor suppressor) are the most common genetic alteration. It was previously reported that cells carrying wild-type (WT) p53 exhibit accelerated senescence and significant rates of apoptosis in response to RT, whereas cells harboring mutant p53 (mutp53) do not. This study investigated the combination of the alpha-emitting atoms RT based on internal Radium-224 (Ra) sources and systemic APR-246 (a p53 reactivating compound) to treat tumors with mutant p53. Cellular models of colorectal cancer (CRC) or pancreatic ductal adenocarcinoma (PDAC) harboring mutant p53, were exposed to alpha particles, and tumor xenografts with mutant p53 were treated using Ra source and APR-246. Effects on cell survival and tumor growth, were assessed. The spread of alpha emitters in tumors was also evaluated as well as the spatial distribution of apoptosis within the treated tumors. We show that mutant p53 cancer cells exhibit radio-sensitivity to alpha particles in vitro and to alpha-particles-based RT in vivo. APR-246 treatment enhanced sensitivity to alpha radiation, leading to reduced tumor growth and increased rates of tumor eradication. Combining alpha-particles-based RT with p53 restoration via APR-246 triggered cell death, resulting in improved therapeutic outcomes. Further preclinical and clinical studies are needed to provide a promising approach for improving treatment outcomes in patients with mutant p53 tumors.
Topics: Alpha Particles; Humans; Tumor Suppressor Protein p53; Animals; Mice; Radiation-Sensitizing Agents; Mutation; Quinuclidines; Cell Line, Tumor; Mice, Nude; Xenograft Model Antitumor Assays; Apoptosis; Neoplasms
PubMed: 38890278
DOI: 10.1038/s41419-024-06830-3 -
Nutrition, Metabolism, and... May 2024Systemic inflammation and oxidation are primary contributors to the development of atherosclerosis. Oxidation of low-density lipoprotein (LDL) particles within the...
BACKGROUND AND AIMS
Systemic inflammation and oxidation are primary contributors to the development of atherosclerosis. Oxidation of low-density lipoprotein (LDL) particles within the vascular endothelium has been hypothesized to be an initial step in the formation of atherosclerotic plaques, with inflammatory cytokines serving as the signaling mechanism for concomitant macrophage activation. Supplementation with the antioxidative macular xanthophylls (lutein [L], zeaxanthin [Z], and meso-zeaxanthin [MZ]) has been shown to aid in the reduction of inflammatory physiologic responses; therefore, we hypothesized that in our study population, supplementation with these xanthophylls would facilitate a systemic reduction in markers of inflammation and cardiovascular lipid oxidation.
METHODS AND RESULTS
In this double-blind placebo-controlled supplementation study, participants were randomly allocated to receive the active intervention containing L (10 mg) + MZ (10 mg) + Z (2 mg) or placebo (containing sunflower oil). Serum concentrations of carotenoids (assessed by HPLC), inflammatory cytokines (IL-6, IL-1β, TNF-α) and oxidized LDL (OxLDL; by solid-phase sandwich ELISA) were measured at baseline and at 6-months. Results showed that over the supplementation period, compared to placebo, the active group demonstrated statistically significant increases in serum concentrations of L, Z, & MZ (p < 0.05), reductions in inflammatory cytokines IL-1β (p < 0.001) and TNF-α (p = 0.003), as well as a corresponding reduction in serum OxLDL (p = 0.009).
CONCLUSIONS
Our data show that L, Z, & MZ supplementation results in decreased serum IL-1β, TNF-α, and OxLDL. This suggests that these carotenoids are acting systemically to attenuate oxidative lipid products and inflammation, thus reducing their contribution to atherosclerotic plaque formation.
PubMed: 38890092
DOI: 10.1016/j.numecd.2024.05.009 -
Health Physics Jun 2024Imaging plates can measure isotopes with alpha decay (such as radon and its progeny, americium, and so on). However, the detection efficiency of imaging plates is...
Imaging plates can measure isotopes with alpha decay (such as radon and its progeny, americium, and so on). However, the detection efficiency of imaging plates is affected by alpha particle energy, types of imaging plates, and the overlapping effect. In this study, simulations were performed to analyze the relationship between detection efficiency and these three influence factors. The research findings suggest that BAS-TR and BAS-MS are well-suited for the detection of alpha particles with energy levels below 6.83 MeV and above, respectively. The track overlap effect correction method proposed in this study is applicable to both BAS-TR and BAS-MS image plates. The measurement results of radon progeny demonstrate that the correction method enhances the detection efficiency from 0.203 to 0.288. This study presents a valuable approach for selecting the appropriate image plate and correcting the track overlap effect in the measurement of alpha radioactive material concentration and other related information.
PubMed: 38888445
DOI: 10.1097/HP.0000000000001828 -
Clinical Oral Investigations Jun 2024Longitudinal assessment of the role of specific proteins on radiotherapy caries (RC) onset in head and neck cancer patients(HNC) up to one-year post-IMRT using a 5000ppm...
Longitudinal study of the role of salivary proteins on radiation-related caries onset in head and neck cancer patients using 5000 ppm fluoride dentifrice up to one-year post-intensity modulated radiotherapy.
OBJECTIVES
Longitudinal assessment of the role of specific proteins on radiotherapy caries (RC) onset in head and neck cancer patients(HNC) up to one-year post-IMRT using a 5000ppm fluoride paste daily.
MATERIALS AND METHODS
Dental status/salivary protein data were obtained from 40 HNC patients pre-IMRT, six months (T1) and 12 months (T2) post-IMRT (ethical approval/consent). DMFT/salivary parameters were quantified, including flow rate, mucin 5B/7, Immunoglobulin A (IgA), cystatin S and α-amylase.
RESULTS
45% patients had at least one carious lesion at T2, a significant reduction in the number of remaining teeth (65% <21), salivary flow rate (< 50%) and, protein secretion (< 0.05) post-IMRT. T1 IgA concentration/secretion rate was associated with RC (p < 0.05). Finally, IgA and total protein concentration obtained at T1 could provide a predictive pattern (AUC 82.3%) for the patients more predisposed to developing RC at T2.
CONCLUSIONS
This study demonstrated the significant association of RC with salivary proteins in HNC patients treated with IMRT, revealing the potential role of salivary proteins in the early diagnosis of RC.
CLINICAL RELEVANCE
This research contributes to revealing salivary proteins association with RC, and its role in early diagnosis. Therefore, this could be the first step towards personalized medicine approaches to improve this group quality-of-life.
Topics: Humans; Dental Caries; Male; Salivary Proteins and Peptides; Head and Neck Neoplasms; Female; Middle Aged; Longitudinal Studies; Radiotherapy, Intensity-Modulated; Dentifrices; Aged; Fluorides; Adult; DMF Index; Immunoglobulin A; Saliva
PubMed: 38886263
DOI: 10.1007/s00784-024-05788-y -
ACS Nano Jun 2024Lanthanide vanadate (LnVO) nanoconstructs have generated considerable interest in radiotherapeutic applications as a medium for nanoscale-targeted drug delivery. For...
Lanthanide vanadate (LnVO) nanoconstructs have generated considerable interest in radiotherapeutic applications as a medium for nanoscale-targeted drug delivery. For cancer treatment, LnVO nanoconstructs have shown promise in encapsulating and retaining radionuclides that emit alpha-particles. In this work, we examined the structure formation of LnVO nanoconstructs doped with actinium (Ac) and radium (Ra), both experimentally and using large-scale atomistic molecular dynamics simulations. LnVO nanoconstructs were synthesized via a precipitation method in aqueous media. The reaction conditions and elemental compositions were varied to control the structure, fluorescence properties, and size distribution of the LnVO nanoconstructs. LnVO nanoconstructs were characterized by X-ray diffraction, Raman spectroscopy, and fluorescence spectroscopy. Molecular dynamics simulations were performed to obtain a fundamental understanding of the structure-property relationship between radionuclides and LnVO nanoconstructs at the atomic length scale. Molecular dynamics simulations with well-established force field (FF) parameters show that Ra atoms tend to distribute across the nanoconstructs' surface in a broader coordination shell, while the Ac atoms are arranged inside a smaller coordination shell within the nanocluster. The Ba atoms prefer to self-assemble around the surface. These theoretical/simulation predictions of the atomistic structures and an understanding of the relationship between radionuclides and LnVO nanoconstructs at the atomic scale are important because they provide design principles for the future development of nanoconstructs for targeted radionuclide delivery.
PubMed: 38885179
DOI: 10.1021/acsnano.3c13213 -
GeroScience Jun 2024Beyond their activity in hemostasis and thrombosis, recent advances attribute platelets a pro-youthful role capable to attenuate immune senescence and age-related...
Beyond their activity in hemostasis and thrombosis, recent advances attribute platelets a pro-youthful role capable to attenuate immune senescence and age-related neuroinflammation. Previous studies from our group associated a polymorphic haplotype variant in the BPIFB4 gene (LAV-BPIFB4) with exceptional longevity. Transfer of the LAV-BPIFB4 in preclinical models has proved strategic to cope with frailty conditions, aging-related events, e.g., cardiovascular ones, and immune dysfunction mainly through a favorable conditioning of the immune system. However, whether platelets participate in LAV-BPIFB4 therapeutic action is currently unknown. Herein, we discovered that platelets were instrumental in boosting the favorable health outcomes of the systemic AAV-LAV-BPIFB4 gene transfer in vivo, as the α-CD42b platelet depletion completely abolished the vascular protective action of LAV-BPIFB4 and suppressed its pro-resolutive CD206 + anti-/CD86 + pro-inflammatory Ly6C + monocyte skewing to LPS stimulation. Of note, this is associated with a huge drop in the protective levels of BPIFB4 in the plasma of AAV-LAV-BPIFB4-injected C57BL/6 mice, indicating that plasma circulating platelets may be a reservoir of the BPIFB4 protein. Indeed, we noticed that BPIFB4 was released by human platelets, a process that is amplified in LAV-allele carrier donors. Accordingly, lentivirus-mediated overexpression of human LAV-BPIFB4 isoform, but not WT-BPIFB4 isoform was able in leading differentiated megakaryocytes to release more platelet-like-particles enriched for BPIFB4. In addition, in vitro, the M2 macrophage polarization increased when releasate from platelets, and even more from LAV pre-stimulated once, was added in monocyte cell culture. Our data suggest that platelet release of BPIFB4 and of yet-to-be-determined unidentified factors mediates the therapeutic efficacy of LAV-BPIFB4 treatment.
PubMed: 38884925
DOI: 10.1007/s11357-024-01242-9 -
Radiation and Environmental Biophysics Jun 2024The epidemiological approach to converting radon exposure to effective dose is examined. Based on the definition of the effective dose, the dose conversion is obtained...
The epidemiological approach to converting radon exposure to effective dose is examined. Based on the definition of the effective dose, the dose conversion is obtained from the equivalence of lung-specific detriment associated with low-LET radiation and with radon exposure. This approach most reliably estimates effective dose per radon exposure on the basis of epidemiological data and implicitly includes the radiation weighting factor required to calculate the effective dose from radon exposure using the dosimetric approach, applying biokinetic and dosimetric models. Consistency between the results of the epidemiological and dosimetric approaches is achieved by using a radiation weighting factor of about 10 for alpha particles instead of the current ICRP value of 20. In contrast, the epidemiological approach implemented in ICRP 65, and referred to as dose conversion convention, was based on direct comparison of total radiation detriment with lung detriment from radon exposure. With the revision of radiation detriments in ICRP 103, this approach can be judged to overestimate the effective dose per radon exposure by about a factor of two because the tissue weighting factor for lung differs from the value of relative detriment to which it relates.
PubMed: 38884804
DOI: 10.1007/s00411-024-01077-0