Fluorescent magnetic Fe3 O4 /rare Earth colloidal nanoparticles for dual-modality imaging.

Fluorescent magnetic colloidal nanoparticles (FMCNPs) are produced by a two-step, seed emulsifier-free emulsion polymerization in the presence of oleic acid and sodium undecylenate-modified Fe3 O4 nanoparticles (NPs). The Fe3 O4 /poly(St-co-GMA) nanoparticles are first synthesized as the seed and Eu(AA)3 Phen is copolymerized with the remaining St and GMA to form the fluorescent polymer shell in the second step. The uniform core-shell structured FMCNPs with a mean diameter of 120 nm exhibit superparamagnetism with saturation magnetization of 1.92 emu/g. Red luminescence from the FMCNPs is confirmed by the salient fluorescence emission peaks of europium ions at 594 and 619 nm as well as 2-photon confocal scanning laser microscopy. The in vitro cytotoxicity test conducted using the MTT assay shows good cytocompatibility and the T2 relaxivity of the FMCNPs is 353.86 mM(-1) S(-1) suggesting its potential in magnetic resonance imaging (MRI). In vivo MRI studies based on a rat model show significantly enhanced T2 -weighted images of the liver after administration and prussian blue staining of the liver tissue slice reveals accumulation of FMCNPs in the organ. The cytocompatibility, superparamagnetism, and excellent fluorescent properties of FMCNPs make them suitable for biological imaging probes in MRI and optical imaging.

Clinical Value of COVID-19 Chest Radiography and High-Resolution CT Examination.

BACKGROUND: Novel coronavirus disease 2019 (COVID-19) pneumonia remains a matter of concern. Chest CT findings of COVID-19 pneumonia have been reported widely, while there is relatively rare research on chest X-ray (CXR). OBJECTIVE: The study was aimed to compare the CXR and chest CT findings of patients with confirmed COVID-19 infection and to explore their respective clinical values. METHODS: 28 inpatients with COVID-19 pneumonia who underwent both CXR and CT were included. The pulmonary manifestations of the lesions were recorded. Ground-glass opacity (GGO), consolidation, and fibrosis were quantified in CXR and chest CT separately. Consistency was analyzed using Fleiss' kappa and intraclass correlation coefficient. The stages of the disease in CXR and chest CT were evaluated. RESULTS: Approximately 67.9% (19/28) of subjects had abnormal findings on CXR. The common manifestations in CXR were ground-glass opacities (GGO) (100%, 19/19) and consolidation (68.4%, 13/19). 92.9% (26/28) of patients had abnormal manifestations on CT. The common manifestations in CT were GGO (88.5%, 23/26), consolidation (69.2%, 18/26), reticular opacity (69.2%, 18/26) and nodule (46.2%, 12/26). Among the abnormalities between CXR and CT, only consolidation was consistent (κ=0.510). GGO (ICC=0.501) and consolidation (ICC=0.431) scores were consistent in CXR and chest CT. The results of staging were the same in 14 cases, most of them were in stage I and stage II. While in other cases with inconsistent results, CT was more advanced in the disease stage than CXR, mainly stage III and stage IV. CONCLUSION: CXR is helpful to observe the change of the pulmonary lesions in patients with confirmed COVID-19 pneumonia. CT can be used for early diagnosis and staging of lesions.

Headache frequency associates with brain microstructure changes in patients with migraine without aura.

Neuroimaging studies have implicated abnormal brain microstructure in episodic migraine (EM), but whether the pattern is altered during migraine chronification is not well known. Fifty-six patients with migraine without aura, including 39 EM patients and 17 chronic migraine (CM) patients, and 35 healthy controls (HCs) were enrolled. Voxel-based morphometry analysis was performed to assess gray matter (GM) volume differences among groups and their association with clinical feature was examined. Compared with the HC group, both migraine groups showed increased GM volume in the periaqueductal grey matter (PAG) and decreased GM volume in the anterior cingulate cortex (ACC). The left hippocampus/parahippocampal gyrus (PHG) volume of the HC group was smaller than that of the EM group, but was larger than that of the CM group. For the dorsolateral prefrontal cortex (dlPFC), the EM group showed the smallest GM volume while the CM group had the largest volume. Higher headache frequency was associated with greater GM volume in the PAG and dlPFC, but was associated with smaller GM volume in the ACC and hippocampus/PHG across all patients. GM volume changes in regions involved in pain generation and control are potential neural mechanism underlying migraine, and are associated with migraine types and headache frequency.

Inspiratory and Expiratory Chest High-resolution CT: Small-airway Disease Evaluation in Patients with COVID-19.

BACKGROUND: An outbreak of coronavirus disease 2019 (COVID-19) has occurred worldwide. However, the small-airway disease in patients with COVID-19 has not been explored. AIM: This study aimed to explore the small-airway disease in patients with COVID-19 using inspiratory and expiratory chest high-resolution computed tomography (CT). METHODS: This multicenter study included 108 patients with COVID-19. The patients were classified into five stages (0-IV) based on the CT images. The clinical and imaging data were compared among CT images in different stages. Patients were divided into three groups according to the time interval from the initial CT scan, and the clinical and air trapping data were compared among these groups. The correlation between clinical parameters and CT scores was evaluated. RESULTS: The clinical data, including age, frequency of breath shortness and dyspnea, neutrophil percentage, lymphocyte count, PaO2, PaCO2, SaO2, and time interval between the onset of illness and initial CT, showed significant differences among CT images in different stages. A significant difference in the CT score of air trapping was observed between stage I and stage III. A low negative correlation was found between the CT score of air trapping and the time interval between the onset of symptoms and initial CT. No significant difference was noted in the frequency and CT score of air trapping among different groups. CONCLUSION: Some patients with COVID-19 developed small-airway disease. Air trapping was more distinguished in the early stage of the disease and persisted during the 2-month follow-up. Longer-term follow-up studies are needed to confirm the findings.

Clinical characteristics and changes of chest CT features in 307 patients with common COVID-19 pneumonia infected SARS-CoV-2: A multicenter study in Jiangsu, China.

OBJECTIVE: The study was aimed to describe the clinical characteristics and evaluate the dynamic changes of chest CT features in the first three weeks in the common type fo COVID-19 pneumonia patients in Jiangsu Province. METHODS: 307 patients infected SARS-CoV-2 classified as common type were enrolled in the study. 628 chest CT scans were divided into three groups based on the time interval between symptoms and chest CT scan. The clinical characteristics were descriptively analyzed.The chest CT features were quantitatively evaluated. Mann-Whitney U test was used to test the differences in three groups and between men and women. Spearman rank correlation was used to test the association between the arterial blood gas(ABG) analysis results and chest CT scores. RESULTS: Fever (69.1%) and cough (62.8%) were common symptoms. 111(36.2%) patients were anorexia. GGO was the most common manifestation of COVID-19 pneumonia, which could be followed by consolidation and fibrosis. Lower lobe or subpleural region was the most common distribution form of lesion. More lung lobes were involved in the third week. Total chest CT scores in the second week were higher than the first week. Fibrosis Scores increased in the second and third week. Total CT score, GGO score and fibrosis score of male patients were significantly higher than female in the second week. Male patients had higher consolidation score and fibrosis score than female in the third week. Total CT score and GGO score had weak to moderate correlation with arterial blood gas indices. CONCLUSION: Changes in chest CT were difficult to assess quantitatively in the first third weeks. Male patients recovered slower than female in the second week. Although CT score had correlations with arterial blood gas indices, long-term follow-up of pulmonary function test is needed to determine the recovery of lung.

High-resolution Chest CT Features and Clinical Characteristics of Patients Infected with COVID-19 in Jiangsu, China.

BACKGROUND: A pneumonia associated with the coronavirus disease 2019 (COVID-19) recently emerged in China. It was recognized as a global health hazard. METHODS: 234 inpatients with COVID-19 were included. Detailed clinical data, chest HRCT basic performances and certain signs were recorded Ground-glass opacity (GGO), consolidation, fibrosis and air trapping were quantified. Both clinical types and CT stages were evaluated. RESULTS: Most patients (approximately 90%) were classified as common type and with epidemiologic history. Fever and cough were main symptoms. Chest CT showed abnormal attenuation in bilateral multiple lung lobes, distributed in the lower and/or periphery of the lungs (94.98%), with multiple shapes. GGO and vascular enhancement sign were most frequent seen, followed by interlobular septal thickening and air bronchus sign as well as consolidation, fibrosis and air trapping. There were significant differences in most of CT signs between different stage groups. The SpO2 and OI were decreased in stage IV, and the CT score of consolidation, fibrosis and air trapping was significantly lower in stage I (P<0.05). A weak relevance was between the fibrosis score and the value of PaO2 and SpO2 (P<0.05). CONCLUSIONS: Clinical performances of patients with COVID-19, mostly with epidemiologic history and typical symptoms, were critical valuable in the diagnosis of the COVID-19. While chest HRCT provided the distribution, shape, attenuation and extent of lung lesions, as well as some typical CT signs of COVID-19 pneumonia.

Folate-bovine serum albumin functionalized polymeric micelles loaded with superparamagnetic iron oxide nanoparticles for tumor targeting and magnetic resonance imaging.

Polymeric micelles functionalized with folate conjugated bovine serum albumin (FA-BSA) and loaded with superparamagnetic iron oxide nanoparticles (SPIONs) are investigated as a specific contrast agent for tumor targeting and magnetic resonance imaging (MRI) in vitro and in vivo. The SPIONs-loaded polymeric micelles are produced by self-assembly of amphiphilic poly(HFMA-co-MOTAC)-g-PEGMA copolymers and oleic acid modified Fe3O4 nanoparticles and functionalized with FA-BSA by electrostatic interaction. The FA-BSA modified magnetic micelles have a hydrodynamic diameter of 196.1 nm, saturation magnetization of 5.5 emu/g, and transverse relaxivity of 167.0 mM(-1) S(-1). In vitro MR imaging, Prussian blue staining, and intracellular iron determination studies demonstrate that the folate-functionalized magnetic micelles have larger cellular uptake against the folate-receptor positive hepatoma cells Bel-7402 than the unmodified magnetic micelles. In vivo MR imaging conducted on nude mice bearing the Bel-7402 xenografts after bolus intravenous administration reveals excellent tumor targeting and MR imaging capabilities, especially at 24h post-injection. These findings suggest the potential of FA-BSA modified magnetic micelles as targeting MRI probe in tumor detection.

Conjugation of functionalized SPIONs with transferrin for targeting and imaging brain glial tumors in rat model.

Currently, effective and specific diagnostic imaging of brain glioma is a major challenge. Nanomedicine plays an essential role by delivering the contrast agent in a targeted manner to specific tumor cells, leading to improvement in accurate diagnosis by good visualization and specific demonstration of tumor cells. This study investigated the preparation and characterization of a targeted MR contrast agent, transferrin-conjugated superparamagnetic iron oxide nanoparticles (Tf-SPIONs), for brain glioma detection. MR imaging showed the obvious contrast change of brain glioma before and after administration of Tf-SPIONs in C6 glioma rat model in vivo on T2 weighted imaging. Significant contrast enhancement of brain glioma could still be clearly seen even 48 h post injection, due to the retention of Tf-SPIONs in cytoplasm of tumor cells which was proved by Prussian blue staining. Thus, these results suggest that Tf-SPIONs could be a potential targeting MR contrast agent for the brain glioma.