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1.
Front Nucl Med ; 4: 1398773, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39355209

RESUMO

Introduction: Pediatric patients have an increased risk of radiation-induced malignancies due to their ongoing development and long remaining life span. Thus, optimization of PET protocols is an important task in pediatric nuclear medicine. Long axial field-of-view (LAFOV) PET/CT has shown a significant increase in sensitivity, which provides an ideal opportunity for reduction of injected tracer activity in the pediatric population. In this study we aim to evaluate the clinical performance of a 2-[18F]FDG-tracer reduction from 3 MBq/kg to 1.5 MBq/kg on the Biograph Vision Quadra LAFOV PET/CT. Materials and methods: The first 50 pediatric patients referred for clinical whole-body PET/CT with 1.5 MBq/kg 2-[18F]FDG, were included. A standard pediatric protocol was applied. Five reconstructions were created with various time, filter and iteration settings. Image noise was computed as coefficient-of-variance (COV = SD/mean standardized-uptake-value) calculated from a spherical 20-50 mm (diameter) liver volume-of-interest. Sets of reconstructions were reviewed by one nuclear medicine physicians, who reported image lesions on a pre-defined list of sites. Paired comparison analysis was performed with significance at PB < 0.05 (Bonferroni corrected). Results: All reconstructions, except one, achieved a COVmean (0.08-0.15) equal to or lower than current clinical acceptable values (COVref ≤ 0.15). Image noise significantly improved with increasing acquisition time, lowering iterations (i) from 6i to 4i (both with five subsets) and when applying a 2 mm Gauss filter (PB < 0.001). Significant difference in lesion detection was seen from 150s to 300s and from 150s to 600s (PB = 0.006-0.007). 99% of all lesions rated as malignant could be found on the 150s reconstruction, while 100% was found on the 300s, when compared to the 600s reconstruction. Conclusion: Injected activity and scan time can be reduced to 1.5 MBq/kg 2-[18F]FDG with 5 min acquisition time on LAFOV PET/CT, while maintaining clinical performance in the pediatric population. These results can help limit radiation exposure to patients and personnel as well as shorten total scan time, which can help increase patient comfort, lessen the need for sedation and provide individually tailored scans.

2.
Am J Obstet Gynecol MFM ; : 101508, 2024 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-39357802

RESUMO

BACKGROUND: Following the results of the ARRIVE trial, which demonstrated a reduction in cesarean delivery with no increase in adverse perinatal outcomes after elective induction of labor (IOL) in low-risk nulliparous patients at 39 weeks' gestation compared with expectant management, the use of induction has increased. Current evidence is insufficient to recommend mid-high-dose over low-dose regimens for routine IOL. OBJECTIVE(S): We sought to evaluate the association of oxytocin regimen with cesarean delivery and an adverse perinatal composite outcome in low-risk nulliparous patients undergoing IOL at 39 weeks of gestation or greater. STUDY DESIGN: This is a secondary analysis of the NICHD Maternal-Fetal Medicine Units Network ARRIVE randomized trial. Patients induced with a mid-to high-dose oxytocin regimen (MHD; starting or incremental increase >2 mU/min) were compared with those receiving a low-dose oxytocin regimen (LD; starting and incremental increase ≤2 mU/min). The co-primary outcomes for this secondary analysis were 1) cesarean delivery and 2) composite of perinatal death or severe neonatal complications. Multivariable Poisson regression was used to estimate adjusted relative risks (aRR) and 97.5% confidence intervals (CI) for the co-primary endpoints, 95% CI for binomial outcomes and multinomial logistic regression was used to estimate adjusted odds ratios (aOR) and 95% CIs for multinomial outcomes. RESULTS: Of 6,106 participants enrolled in the primary trial, 2,933 underwent induction with oxytocin: 861 in the MHD group and 2,072 in the LD group. The lower frequency of cesarean delivery in the MHD group compared with the LD group (20.3% vs. 25.2%, RR 0.81, 95%CI (0.69-0.94)) was not significant after adjustment (aRR 0.90, 97.5%CI (0.76-1.07)). The composite of perinatal death or severe neonatal complications was more frequent in the MHD group compared with the LD group (6.7% vs. 4.3%, RR 1.55, 95%CI (1.13-2.14)) and remained significant after adjustment (aRR 1.61, 97.5%CI (1.11-2.35)). The majority of the cases in the composite were from the respiratory support (5.2% vs. 3.1%) component with an increase in transient tachypnea of the newborn (3.8% vs. 2.5%, aRR 1.63, 95% CI (1.04-2.54)). The duration of neonatal respiratory support for one day was significantly higher in the MHD group compared with the LD group (3.5% vs. 1.4%, aRR 2.59, 95%CI (1.52-4.39)); however, support beyond one day was not different between the two groups. The MHD group, when compared with the LD group had a higher operative vaginal delivery rate (10.0% vs. 7.0%, aRR 1.54, 95%CI (1.18-2.00)) and shorter duration of time from start of oxytocin to delivery [crude median (interquartile range) 12 (8-17) vs. 13 (9-19) hours, adjusted median difference -2 (-2 to -1), p<0.001], respectively. CONCLUSION(S): Mid-high-dose oxytocin regimen use for IOL in nulliparas at ≥ 39 weeks' gestation was not associated with improved maternal or neonatal outcomes compared with low-dose regimens. Although mid-high-dose oxytocin regimen use was associated with a shorter duration of labor, there was an increase in self-limited neonatal respiratory support and no difference in cesarean rates. More evidence is needed to define the magnitude of potential maternal and neonatal benefits and risks associated with oxytocin regimens.

3.
Microsc Microanal ; 2024 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-39270660

RESUMO

In the scanning transmission electron microscope, both phase imaging of beam-sensitive materials and characterization of a material's functional properties using in situ experiments are becoming more widely available. As the practicable scan speed of 4D-STEM detectors improves, so too does the temporal resolution achievable for both differential phase contrast (DPC) and ptychography. However, the read-out burden of pixelated detectors, and the size of the gigabyte to terabyte sized data sets, remain a challenge for both temporal resolution and their practical adoption. In this work, we combine ultra-fast scan coils and detector signal digitization to show that a high-fidelity DPC phase reconstruction can be achieved from an annular segmented detector. Unlike conventional analog data phase reconstructions from digitized DPC-segment images yield reliable data, even at the fastest scan speeds. Finally, dose fractionation by fast scanning and multi-framing allows for postprocess binning of frame streams to balance signal-to-noise ratio and temporal resolution for low-dose phase imaging for in situ experiments.

4.
BMC Med Imaging ; 24(1): 238, 2024 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-39261796

RESUMO

This systematic review aimed to evaluate the potential of deep learning algorithms for converting low-dose Positron Emission Tomography (PET) images to full-dose PET images in different body regions. A total of 55 articles published between 2017 and 2023 by searching PubMed, Web of Science, Scopus and IEEE databases were included in this review, which utilized various deep learning models, such as generative adversarial networks and UNET, to synthesize high-quality PET images. The studies involved different datasets, image preprocessing techniques, input data types, and loss functions. The evaluation of the generated PET images was conducted using both quantitative and qualitative methods, including physician evaluations and various denoising techniques. The findings of this review suggest that deep learning algorithms have promising potential in generating high-quality PET images from low-dose PET images, which can be useful in clinical practice.


Assuntos
Aprendizado Profundo , Tomografia por Emissão de Pósitrons , Doses de Radiação , Humanos , Tomografia por Emissão de Pósitrons/métodos , Processamento de Imagem Assistida por Computador/métodos
5.
Transl Cancer Res ; 13(8): 4290-4300, 2024 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-39262493

RESUMO

Background: Apatinib is a tyrosine kinase inhibitor that has shown potential in combination with immune checkpoint inhibitors (ICIs) in gastric cancer (GC); however, its role in GC is unclear. This research aims to investigate the effect of low-dose apatinib in GC, and analyze the mechanisms of its underlying action. Methods: A mouse model of GC was established, and the experimental mice were divided into different groups for different treatment: group NS (normal saline), group A (low-dose apatinib 50 mg/kg), group B (high-dose apatinib 200 mg/kg), group C [programmed cell death protein 1 (PD-1) inhibitor monotherapy], and group D (PD-1 inhibitor combined with low-dose apatinib). After 14 days of treatment, the tumor and blood samples were collected from all mice for histological and cytokine detection. Results: Compared with the control group, mice in the low-dose apatinib group showed smaller tumor volumes and slower growth. CD31/α-smooth muscle actin (α-SMA) double staining revealed significantly higher coverage of perivascular cells in the low-dose apatinib group by contrast to the control and high-dose apatinib groups, suggesting that low-dose apatinib may alleviate hypoxia. Compared to the high-dose apatinib group, the expression of hypoxia inducible factor 1 alpha (HIF1α) significantly decreased in the low-dose apatinib group. Hematoxylin and eosin (HE) staining results showed a higher proportion of necrotic tumor tissues in the group of mice treated with low-dose apatinib combined with PD-1 inhibitor than in other groups. In addition, this combined treatment significantly reduced the expression of NG2 and HIF1α in mouse tumor tissues, indicating a more normalized vascular density, and also increased the proportion of CD8+ T cells. Conclusions: Low-dose apatinib enhances the antitumor effect of PD-1 inhibitor by normalizing tumor-related blood vessels, alleviating intratumor hypoxia and altering immunosuppressive microenvironment (IM).

6.
Transl Lung Cancer Res ; 13(8): 1877-1887, 2024 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-39263014

RESUMO

Background: Despite its efficacy in reducing lung cancer (LC)-specific mortality by 20%, screening with low-dose computed tomography (LDCT) in eligible groups remains low (5-16%). Black individuals are more commonly affected by LC than other racial/ethnic groups in the United States (U.S.) but less likely to undergo LC screening (LCS). Our study aimed to explore the knowledge and beliefs of Black individuals at high risk regarding LCS. Methods: Black individuals (n=17) who met the 2021 United States Preventive Services Task Force (USPSTF) LCS eligibility criteria were recruited in upstate New York. In-depth semi-structured interviews were conducted, audio recorded, and transcribed to explore knowledge and beliefs that could influence the uptake of LCS. A qualitative thematic analysis method was used to identify and analyze themes within the data. Results: We identified principal themes about LC and LCS. Although most participants reported that smoking was the major risk factor for LC, some participants placed more emphasis on other factors as the major risk factors for LC and de-emphasized the role of smoking. Most participants were not aware that screening for LC existed. Several barriers and facilitators for LCS were identified. Conclusions: Awareness about LCS among Black individuals is low. Addressing barriers may help increase LCS rates among Black individuals, ultimately reducing their LC mortality. The findings from our study have important implications in designing more effective interventions involving community health workers and healthcare clinicians to increase LCS uptake among Black individuals at high risk.

7.
Transl Lung Cancer Res ; 13(8): 1918-1928, 2024 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-39263020

RESUMO

Background: With increasing significance of lung cancer screening programs, it is essential to determine the group of participants, who would benefit the most from screening. In our study, we aimed to establish the correlation between lung emphysema and lung cancer risk. Methods: The study design was cross-sectional. Low-dose computed tomography (LDCT) scans of 896 subjects from MOLTEST-BIS lung cancer screening program, including 100 subjects with detected lung cancer, were visually evaluated for the presence, type and severity of emphysema. Quantitative emphysema evaluation was performed with Siemens syngo.via Pulmo 3D application. Results: Visually detected presence of centrilobular emphysema (CLE) correlated with male gender (P=0.02), age (P<0.001) and pack-years of smoking (P=0.004), as well as with quantitative assessment of Emphysema Index (EI) (P=0.008), and with emphysema clusters of given size (Clas 1-4) Clas 1, Clas 3 and Clas 4 (P<0.001). Visually assessed severity grade of emphysema correlated with age (P<0.001), pack-years of smoking history (P=0.002) and EI (P<0.001). There was a correlation between lung cancer occurrence and pack-years (P<0.001), age (P<0.001), and presence of CLE (P<0.001) but no correlation with gender (P=0.88) and EI (P=0.32) was found. In the logistic regression model pack-years, age, qualitative severity of CLE and Clas 1 were significant factors correlated with lung cancer occurrence (P<0.001). Conclusions: Qualitative and quantitative emphysema evaluation correlate with each other. Both, presence and severity of CLE correlate with higher incidence of lung cancer. Severity of visually assessed emphysema, age and pack-years of smoking are significant predictors of lung cancer occurrence.

8.
J Imaging Inform Med ; 2024 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-39261373

RESUMO

Deep learning-based denoising of low-dose medical CT images has received great attention both from academic researchers and physicians in recent years, and has shown important application value in clinical practice. In this work, a novel two-branch and multi-scale residual attention-based network for low-dose CT image denoising is proposed. It adopts a two-branch framework structure, to extract and fuse image features at shallow and deep levels respectively, to recover image texture and structure information as much as possible. We propose the adaptive dynamic convolution block (ADCB) in the local information extraction layer. It can effectively extract the detailed information of low-dose CT denoising and enables the network to better capture the local details and texture features of the image, thereby improving the denoising effect and image quality. Multi-scale edge enhancement attention block (MEAB) is proposed in the global information extraction layer, to perform feature fusion through dilated convolution and a multi-dimensional attention mechanism. A multi-scale residual convolution block (MRCB) is proposed to integrate feature information and improve the robustness and generalization of the network. To demonstrate the effectiveness of our method, extensive comparison experiments are conducted and the performances evaluated on two publicly available datasets. Our model achieves 29.3004 PSNR, 0.8659 SSIM, and 14.0284 RMSE on the AAPM-Mayo dataset. It is evaluated by adding four different noise levels σ = 15, 30, 45, and 60 on the Qin_LUNG_CT dataset and achieves the best results. Ablation studies show that the proposed ADCB, MEAB, and MRCB modules improve the denoising performances significantly. The source code is available at https://github.com/Ye111-cmd/LDMANet .

9.
Strahlenther Onkol ; 2024 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-39313732

RESUMO

PURPOSE: We evaluated the efficacy of low-dose radiotherapy for painful shoulder syndrome from an orthopedic perspective. METHODS: Patients with painful shoulder syndrome were recruited for this retrospective clinical quality assessment from January 2011 to December 2017. Patients were treated with a linear accelerator or an orthovoltage device at individual doses of 0.5-1.0 Gy and total doses of 3.0-6.0 Gy. To assess response, we used the von Pannewitz score with five levels: "worsened," "unaffected," "improved," "significantly improved," and "symptom free." "Good treatment success" was defined as "significantly improved" and "symptom free." Within-group and between-group differences were statistically evaluated. RESULTS: Of 236 recruited patients (150 women, 86 men; mean age 66.3 [range 31-96] years), 180 patients underwent radiotherapy with a linear accelerator and 56 with an orthovoltage device. Fractionation was 12â€¯× 0.5 Gy in 120 patients, 6â€¯× 0.5 Gy in 74, and 6â€¯× 1 Gy in 42 patients. Treatments were completed in one series for 223 and in two series at least 6 weeks apart for 13 patients. Of the 236 patients, 163 patients (69.1%) agreed to be re-interviewed at a median of 10.5 (range 4-60) months after radiotherapy completion. Directly after radiotherapy, 30.9% (73 patients) had "good treatment success," which had increased to 55.2% (90 patients) at follow-up. CONCLUSION: Protracted pain improvement with low-dose radiotherapy is possible in painful shoulder syndrome. Patients with refractory pain because of subacromial syndrome or shoulder osteoarthritis should also be evaluated for radiotherapy.

10.
Maturitas ; 190: 108117, 2024 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-39317030

RESUMO

OBJECTIVES: Evidence suggests ethnicity-specific differences in postmenopausal symptoms, highlighting the need for therapies that are efficacious across different ethnicities. We evaluated the efficacy of an ultra-low dose combination of 0.5 mg estradiol and 0.25 mg dydrogesterone (E 0.5 mg/D 2.5 mg) in alleviating vasomotor symptoms across a multi-ethnic population. STUDY DESIGN: Data from two controlled trials were pooled to form a dataset of 583 postmenopausal women from across Europe and China. Participants were randomized to receive treatment with E 0.5 mg/D 2.5 mg or placebo for 12 weeks. MAIN OUTCOME MEASURES: The main efficacy variable was absolute change in the number of hot flushes from baseline to end of treatment. Health-related quality of life and safety were also assessed. RESULTS: Change in the number of hot flushes per day was greater with E 0.5 mg/D 2.5 mg versus placebo (mean difference - 1.5, 95 % confidence interval - 2.1, -1.0; p < 0.001). Participants treated with E 0.5 mg/D 2.5 mg reported improvement in health-related quality of life (including psychological symptoms, vaginal dryness), and high amenorrhea rates. Combined E 0.5 mg/D 2.5 mg was well tolerated: there were no differences between groups in the percentage of participants with at least one serious adverse event or treatment-emergent serious adverse events. Analysis of change in body weight indicated no differences between groups. CONCLUSIONS: This pooled analysis demonstrates the consistent efficacy of E 0.5 mg/D 2.5 mg in the treatment of menopause-related symptoms across a multi-ethnic population of postmenopausal women.

11.
Aquat Toxicol ; 276: 107106, 2024 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-39317138

RESUMO

Ionizing radiation, as an increasingly serious environmental pollutant, has aroused widespread public concern. Melatonin, as an indole heterocyclic compound, is known to have anti-inflammatory and antioxidant effects. However, few studies have considered the comprehensive impact of melatonin on radiation damage. In this study, we used zebrafish as experimental materials and employed methods such as acridine orange staining, enzyme-linked immunosorbent assay (ELISA), video tracking for automated behavior analysis, microscope imaging, and real-time fluorescence quantitative analysis. Zebrafish embryos at 2 h post-fertilization (hpf) were treated under four different experimental conditions to assess their growth, development, and metabolic consequences. Our findings indicate that 0.10 Gy gamma radiation significantly augments body length, eye area, spine width, and tail fin length in zebrafish, along with a marked increase in oxidative stress (P < 0.05). Moreover, it enhances cumulative swimming distance, time, and average speed, suggesting elevated activity levels. We observed circadian rhythm phase shifts, peak increases, and cycle shortening, accompanied by abnormal expression of genes pivotal to biological rhythms, exercise, melatonin synthesis, apoptosis/anti-apoptosis, and oxidation/antioxidant balance. The inclusion of melatonin (1 × 10-5 mol/L MLT) ameliorated these radiation-induced anomalies, while its independent effect on zebrafish was negligible. Melatonin can regulate oxidative stress responses, hinders apoptosis responses, and reprogramming the expression of rhythm-related genes in zebrafish embryos after reprogramming radiation stimulation. Overall, our research highlights melatonin's critical role in countering the biological damage inflicted by gamma radiation, proposing its potential as a therapeutic agent in radiation protection.

12.
Neonatology ; : 1-10, 2024 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-39317175

RESUMO

INTRODUCTION: Perinatal asphyxia initiates cytokine release and complement activation with risk of brain damage. We assessed the effect of nicotine on innate immunity and hypothesized that nicotine infusion in a newborn piglet model of asphyxia would decrease the immune response and be neuroprotective. METHODS: Newborn piglets (n = 41) were randomized to one of three groups after hypoxia: two groups receiving nicotine, (1) 18 µg/kg/h (n = 17), (2) 46 µg/kg/h (n = 15), and (3) control group receiving saline (n = 9). C3a, IL-6, TNF, and IL-10 were measured in plasma and IL-6 and IL-8 in microdialysis fluid from cerebral periventricular white matter, using immuno-assays. RESULTS: Plasma C3a and IL-6 increased significantly from start to end hypoxia (mean 4.4 ± 0.55 to 5.6 ± 0.71 ng/mL and 1.66 ± 1.04 to 2.68 ± 0.71 pg/mL, respectively), while IL-10 and TNF increased significantly after 4 h (mean 1.4 ± 1.08 to 2.9 ± 1.87 and 3.3 ± 0.67 to 4.0 ± 0.58 pg/mL, respectively) (p < 0.001 for all). IL-6 increased significantly (p < 0.001) in microdialysis samples from end hypoxia to end experiment (mean 0.65 ± 0.88 to 2.78 ± 1.84 ng/mL). No significant differences were observed between the nicotine groups and the control group neither in plasma nor in microdialysis samples. CONCLUSION: Hypoxia leads to rapid release of cytokines in plasma and cerebral microdialysis fluid, and complement activation measured on C3a. However, low-dose nicotine administration did not affect the immune response.

13.
Cancer ; 2024 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-39302232

RESUMO

The American Cancer Society National Lung Cancer Roundtable strategic plan for provider engagement and outreach addresses barriers to the uptake of lung cancer screening, including lack of provider awareness and guideline knowledge about screening, concerns about potential harms from false-positive examinations, lack of time to implement workflows within busy primary care practices, insufficient infrastructure and administrative support to manage a screening program and patient follow-up, and implicit bias based on sex, race/ethnicity, social class, and smoking status. Strategies to facilitate screening include educational programming, clinical reminder systems within the electronic medical record, decision support aids, and tools to track nodules that can be implemented across a diversity of practices and health care organizational structures. PLAIN LANGUAGE SUMMARY: The American Cancer Society National Lung Cancer Roundtable strategic plan to reduce deaths from lung cancer includes strategies designed to support health care professionals, to better understand lung cancer screening, and to support adults who are eligible for lung cancer screening by providing counseling, referral, and follow-up.

14.
Cancer ; 2024 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-39302237

RESUMO

Lung cancer in women is a modern epidemic and represents a global health crisis. Cigarette smoking remains the most important risk factor for lung cancer in all patients and, among women globally, rates of smoking continue to increase. Although some data exist supporting sex-based differences across the continuum of lung cancer, there is currently a dearth of research exploring the differences in risk, biology, and treatment outcomes in women. Consequently, the American Cancer Society National Lung Cancer Roundtable recognizes the urgent need to promote awareness and future research that will close the knowledge gaps regarding lung cancer in women. To this end, the American Cancer Society National Lung Cancer Roundtable Task Group on Lung Cancer in Women convened a summit undertaking the following to: (1) summarize existing evidence and identify knowledge gaps surrounding the epidemiology, risk factors, biologic differences, and outcomes of lung cancer in women; (2) develop and prioritize research topics and questions that address research gaps and advance knowledge to improve quality of care of lung cancer in women; and (3) propose strategies for future research. PLAIN LANGUAGE SUMMARY: Lung cancer is the leading cause of cancer mortality in women, and, despite comparatively lower exposures to occupational and environmental carcinogens compared with men, disproportionately higher lung cancer rates in women who ever smoked and women who never smoked call for increased awareness and research that will close the knowledge gaps regarding lung cancer in women.

15.
Int J Radiat Biol ; : 1-19, 2024 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-39302823

RESUMO

To quantitatively investigate the effects of chronic low-dose internal exposure to Cesium-137 on DNA damage, carcinogenicity, and offspring over multiple generations. The potential genetic risk in humans was predicted based on next-generation murine mutation rates to confirm the reasonableness of the current Cesium-137 dose limits for food. Cesium-137 (100 Bq/mL) was provided in drinking water to A/J mice, facilitating chronic, low-dose, low-dose-rate internal exposure through sibling mating over 25 generations (G25). The A/J mice were compared with a control strain with the same origin ancestry (no Cesium-137 water) for DNA double-strand breaks (DSBs), oxidative stress, chromosome aberrations, micronucleus test results, whole genome analysis, carcinogenicity, tumor growth rate, and immune competence. Compared to the control group, DNA DSBs and oxidative stress were significantly increased in the Cesium-137 group. However, no significant differences were observed between the groups regarding chromosome aberration, micronuclei, or the whole genome sequence mutation analysis. Although the carcinogenic rate did not differ between the groups, the rate of tumor growth was significantly suppressed in the Cesium-137 group. The anti-tumor cytokine trend in the Cesium-137 group likely contributed to this effect. No pathological or genetic effects were observed in the offspring of mice drinking water containing 100 Bq/mL Cesium-137 after G25. The contribution of low dose-rate radiation to carcinogenicity was not additive but growth-inhibitory. Although the negative data are not conclusive, these findings are deemed highly reliable.

16.
Nucl Med Mol Imaging ; 58(6): 341-353, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39308490

RESUMO

Purpose: Ionizing radiation-based technologies are extensively used in the diagnosis and treatment of diseases. While utilizing the technologies, exposure to a certain amount of radiation is unavoidable. Data can be obtained from participants who received radiation during medical imaging and therapeutic purposes to predict the effects of low-dose radiation. Methods: To understand the effects of low-dose radiation, participants (n = 22) who received radioactive I-131 for scan/therapy were used as a model in this study. Blood samples were drawn pre- and post-administration of I-131. Biological effects were measured using markers of DNA damage (γ-H2AX, micronucleus (MN), and chromosomal aberrations (CA)) and response to damage through gene expression changes (ATM, CDKN1A, DDB2, FDXR, and PCNA) in blood samples. Results: Mean frequency of γ-H2AX foci in pre-samples was 0.28 ± 0.16, and post-samples were 1.03 ± 0.60. γ-H2AX foci frequency obtained from post-samples showed significant (p < 0.0001) and a heterogeneous increase in all the participants (received I-131 for scan/therapy) when compared to pre-samples. A significant increase (p < 0.0001) in MN and CA frequency was also observed in participants who received the I-131 therapy. Gene expression analysis indicates that all genes (ATM, CDKN1A, DDB2, FDXR, and PCNA) were altered in post-samples, although with varying degrees, suggesting that the cellular responses to DNA damage, such as damage repair, cell cycle regulation to aid in repair and apoptosis are increased, which priority is given to repair, followed by apoptosis. Conclusion: The results of this study indicate that the participants who received I-131 (low doses of ß- and γ-radiation) can produce substantial biological effects.

17.
Eur J Immunol ; : e2451268, 2024 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-39285833

RESUMO

Follicular helper (Tfh), peripheral helper (Tph), and regulatory (Treg) T cells are involved in myasthenia gravis (MG) pathogenesis, an autoimmune disorder arising from autoantibodies targeting neuromuscular junction proteins. This study explores the impact of low-dose IL-2 on Tfh, Tph, and Treg cells in vitro in MG. Acetylcholine-receptor antibody-positive MG (AChR-MG), muscle-specific kinase antibody-positive MG (MuSK-MG) patients, and healthy controls (HC) were studied. Blood cells were cultured with/without IL-2 and compared by the ratios of IL-2 stimulated/unstimulated cultures. In both AChR-MG and MuSK-MG patients, CD25+FoxP3+Tregs were lower, while CXCR5+PD-1+ or ICOS+Tfh and CXCR5-PD-1+ or ICOS+Tph cells were higher compared with HC. Among the MG group, the FoxP3+ Treg cells in AChR-MG patients were even lower compared with MuSK-MG patients. In vitro IL-2 stimulation increased Tregs in all groups while decreasing PD-1+/ICOS+Tfh and PD-1+/ICOS+Tph populations. The fold-increase ratio of Tregs and the fold-decrease ratio of PD-1+ or ICOS+Tfh and ICOS+Tph cells in AChR-MG and MuSK-MG patients were greater than in HCs. Low-dose IL-2 treatment may balance Tfh, Tph, and Treg cells in MG patients, offering a potential opportunity for disease modulation.

18.
Artigo em Inglês | MEDLINE | ID: mdl-39278738

RESUMO

BACKGROUND AND AIMS: Body composition has been linked with clinical and prognostic outcomes in patients with cancer and cardiovascular diseases. Body composition analysis in lung cancer screening (LCS) is very limited. This study aimed at assessing the association of subcutaneous fat volume (SFV) and subcutaneous fat density (SFD), measured on chest ultra-low dose computed tomography (ultra-LDCT) images by a fully automated artificial intelligence (AI)-based software, with clinical and anthropometric characteristics in a LCS population. METHODS AND RESULTS: Demographic, clinical, and dietary data were obtained from the written questionnaire completed by each participant at the first visit, when anthropometric measurements, blood sample collection and chest ultra-LDCT were performed. Images were analyzed for automated 3D segmentation of subcutaneous fat and muscle. The analysis included 938 volunteers (372 females); men with a smoking history of ≥40 pack-years had higher SFV (p = 0.0009), while former smokers had lower SFD (p = 0.0019). In female participants, SFV and SFD differed significantly according to age. SFV increased with rising BMI, waist circumference, waist-hip ratio, and CRP levels ≥2 mg/L (p < 0.0001), whereas SFD decreased with rising BMI, waist circumference, waist-hip ratio, and CRP levels ≥2 mg/L (p < 0.001) in both sexes. SFV was associated with glycemia and triglycerides levels (p = 0.0067 and p=<0.0001 in males, p = 0.0074 and p < 0.0001 in females, respectively), while SFD with triglycerides levels (p < 0.0001). CONCLUSION: We observed different associations of SFV and SFD with age and smoking history between men and women, whereas the association with anthropometric data, CRP, glycemia and triglycerides levels was similar in the two sexes.

19.
Phys Med Biol ; 2024 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-39284350

RESUMO

OBJECTIVE: The study aims to reduce the imaging radiation dose in Adaptive Radiotherapy (ART) while maintaining high-quality CT images, critical for effective treatment planning and monitoring. APPROACH: We developed the Prior-aware Learned Primal-Dual Network (pLPD-UNet), which uses prior CT images to enhance reconstructions from low-dose scans. The network was separately trained on thorax and abdomen datasets to accommodate the unique imaging requirements of each anatomical region. MAIN RESULTS: The pLPD-UNet demonstrated improved reconstruction accuracy and robustness in handling sparse data compared to traditional methods. It effectively maintained image quality essential for precise organ delineation and dose calculation, while achieving a significant reduction in radiation exposure. SIGNIFICANCE: This method offers a significant advancement in the practice of ART by integrating prior imaging data, potentially setting a new standard for balancing radiation safety with the need for high-resolution imaging in cancer treatment planning.

20.
Indian J Radiol Imaging ; 34(4): 636-639, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39318580

RESUMO

Aim This article determines the compliance rates with low-dose aspirin (LDA) and outcomes in a group of pregnant women identified at high risk for preeclampsia (PE) and fetal growth restriction (FGR) at 11 to 14 gestational weeks (GWs) in a rural district of central India. Methods A single, experienced fetal radiologist assessed all enrolled pregnant women using trimester-specific antenatal screening protocols that included mean arterial blood pressure assessment, and fetal ultrasound and Doppler studies. A trimester-specific individualized risk for preterm PE and FGR was estimated for each woman. Pregnant women categorized as high risk for preterm PE or FGR based on a 1 in 150 criteria at 11 to 14 GW were recommended LDA 150 mg once daily at bedtime. Outcome measures included compliance with LDA assessed, incidence of PE and FGR, preterm delivery (<37 GW), birth weight, stillbirths, and perinatal mortality. Results The data of 488 pregnant women with longitudinal trimester-specific assessments from 11 to 14 GW till childbirth was analyzed. At the third trimester assessment, 215 (80.83%) of the high-risk women were compliant with LDA. The incidence of PE, FGR, and preterm births was significantly higher in LDA noncompliant women, and the mean birth weight was significantly higher in LDA-compliant high-risk women. Conclusion Good compliance for LDA is possible in rural populations with adequate counseling. Starting LDA at 11 to 14 GW for high-risk pregnant women lowered the incidence of PE, FGR, and preterm birth rates and improved birth weight in the study population.

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