Although 9.4 T magnetic resonance imaging (MRI) has been tested in healthy volunteers, its safety in diabetic patients is unclear. Furthermore, the effects of high static magnetic fields (SMFs), especially gradient vs. uniform fields, have not been investigated in diabetics. Here, we investigated the consequences of exposure to 1.0-9.4 T high SMFs of different gradients (>10 T/m vs. 0-10 T/m) on type 1 diabetic (T1D) and type 2 diabetic (T2D) mice. We found that 14 h of prolonged treatment of gradient (as high as 55.5 T/m) high SMFs (1.0-8.6 T) had negative effects on T1D and T2D mice, including spleen, hepatic, and renal tissue impairment and elevated glycosylated serum protein, blood glucose, inflammation, and anxiety, while 9.4 T quasi-uniform SMFs at 0-10 T/m did not induce the same effects. In regular T1D mice (blood glucose ≥16.7 mmol/L), the >10 T/m gradient high SMFs increased malondialdehyde ( P<0.01) and decreased superoxide dismutase ( P<0.05). However, in the severe T1D mice (blood glucose ≥30.0 mmol/L), the >10 T/m gradient high SMFs significantly increased tissue damage and reduced survival rate. In vitro cellular studies showed that gradient high SMFs increased cellular reactive oxygen species and apoptosis and reduced MS-1 cell number and proliferation. Therefore, this study showed that prolonged exposure to high-field (1.0-8.6 T) >10 T/m gradient SMFs (35-1 380 times higher than that of current clinical MRI) can have negative effects on diabetic mice, especially mice with severe T1D, whereas 9.4 T high SMFs at 0-10 T/m did not produce the same effects, providing important information for the future development and clinical application of SMFs, especially high-field MRI.

9.4 T 核磁共振成像（MRI）已经在健康志愿者中进行了检测，但其对糖尿病患者的影响尚不清楚。稳态强磁场（SMFs），尤其是梯度和/或均匀稳态强磁场对糖尿病的影响也未进行研究。该研究旨在探究不同梯度（>10 T/m 和 0–10 T/m）的1.0–9.4 T高场SMFs对1型糖尿病（T1D）和2型糖尿病（T2D）小鼠的影响。我们发现持续14小时的梯度（高达55.5 T/m）高场（1.0–8.6 T）SMFs处理后，对T1D和T2D小鼠均可产生有害影响，包括：脾脏、肝脏和肾脏组织损伤，以及糖基化血清蛋白、血糖、炎症和焦虑水平升高等；而近均匀SMFs（0–10 T/m，~9.4 T）却没有出现以上现象。在普通的T1D小鼠（血糖≥16.7 mmol/L）肾脏组织中，>10 T/m的梯度高场SMFs增加了组织丙二醛水平（ P<0.01），减少超氧化物歧化酶的含量（ P<0.05）。然而，在严重的T1D小鼠（血糖≥30.0mmol/L）中，>10 T/m梯度高场SMFs不仅明显增加多组织损伤，还降低了严重的T1D小鼠的存活率。体外细胞研究表明，梯度高场SMFs增加了MS-1细胞的活性氧水平，并促进细胞凋亡，减少了MS-1细胞数量和细胞增殖。因此，我们的研究表明，长期暴露于>10 T/m梯度SMFs（比目前临床MRI高35–1380倍）高场（1.0–8.6 T）对糖尿病小鼠，尤其是对严重的T1D小鼠产生有害影响。相反，0–10 T/m的~9.4 T近均匀高场SMFs却没有负面影响，这为SMFs特别是高场MRI的未来发展和临床应用提供了重要信息。.

• Klíčová slova
• Gradient static magnetic field, Magnetic resonance imaging (MRI), Quasi-uniform static magnetic field, Type 1 diabetes, Type 2 diabetes,
• MeSH
• diabetes mellitus 1. typu * veterinární   MeSH
• diabetes mellitus 2. typu * veterinární   MeSH
• experimentální diabetes mellitus * MeSH
• krevní glukóza MeSH
• magnetické pole MeSH
• myši MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• krevní glukóza MeSH

Cell-cycle progression is regulated by numerous intricate endogenous mechanisms, among which intracellular forces and protein motors are central players. Although it seems unlikely that it is possible to speed up this molecular machinery by applying tiny external forces to the cell, we show that magnetic forcing of magnetosensitive bacteria reduces the duration of the mitotic phase. In such bacteria, the coupling of the cell cycle to the splitting of chains of biogenic magnetic nanoparticles (BMNs) provides a biological realization of such forcing. Using a static gradient magnetic field of a special spatial configuration, in probiotic bacteria E. coli Nissle 1917, we shortened the duration of the mitotic phase and thereby accelerated cell division. Thus, focused magnetic gradient forces exerted on the BMN chains allowed us to intervene in the processes of division and growth of bacteria. The proposed magnetic-based cell division regulation strategy can improve the efficiency of microbial cell factories and medical applications of magnetosensitive bacteria.

• Klíčová slova
• bacterial division, biomagnetic effects, intracellular forces, magnetic field, mitosis,
• MeSH
• buněčné dělení MeSH
• buněčný cyklus MeSH
• Escherichia coli * metabolismus   MeSH
• magnetické pole * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The diffusion of biologically active molecules is a ubiquitous process, controlling many mechanisms and the characteristic time scales for pivotal processes in living cells. Here, we show how a high static magnetic field (MF) affects the diffusion of paramagnetic and diamagnetic species including oxygen, hemoglobin, and drugs. We derive and solve the equation describing diffusion of such biologically active molecules in the presence of an MF as well as reveal the underlying mechanism of the MF's effect on diffusion. We found that a high MF accelerates diffusion of diamagnetic species while slowing the diffusion of paramagnetic molecules in cell cytoplasm. When applied to oxygen and hemoglobin diffusion in red blood cells, our results suggest that an MF may significantly alter the gas exchange in an erythrocyte and cause swelling. Our prediction that the diffusion rate and characteristic time can be controlled by an MF opens new avenues for experimental studies foreseeing numerous biomedical applications.

• Klíčová slova
• drug diffusion, hemoglobin, magnetic field, molecular diffusion, red blood cells,
• MeSH
• difuze MeSH
• erytrocyty metabolismus   MeSH
• hemoglobiny metabolismus   MeSH
• kyslík metabolismus   MeSH
• léčivé přípravky metabolismus   MeSH
• magnetické pole * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• hemoglobiny MeSH
• kyslík MeSH
• léčivé přípravky MeSH

Studies have shown that 9.4 Tesla (9.4 T) high-field magnetic resonance imaging (MRI) has obvious advantages in improving image resolution and capacity, but their safety issues need to be further validated before their clinical approval. Meanwhile, emerging experimental evidences show that moderate to high intensity Static Magnetic Fields (SMFs) have some anti-cancer effects. We examined the effects of two opposite SMF directions on lung cancer bearing mice and found when the lung cancer cell-bearing mice were treated with 9.4 T SMFs for 88 h in total, the upward 9.4 T SMF significantly inhibited A549 tumor growth (tumor growth inhibition=41%), but not the downward 9.4 T SMF. In vitro cellular analysis shows that 9.4 T upward SMF treatment for 24 h not only inhibited A549 DNA synthesis, but also significantly increased ROS and P53 levels, and arrested G2 cell cycle. Moreover, the 9.4 T SMF-treatments for 88 h had no severe impairment to the key organs or blood cell count of the mice. Our findings demonstrated the safety of 9.4 T SMF long-term exposure for their future applications in MRI, and revealed the anti-cancer potential of the upward direction 9.4 T SMF.

• Klíčová slova
• 9.4 T static magnetic field (SMF), Cell cycle, Lung cancer, P53, ROS,
• Publikační typ
• časopisecké články MeSH

Interactions between magnetic fields (MFs) and living cells may stimulate a large variety of cellular responses to a MF, while the underlying intracellular mechanisms still remain a great puzzle. On a fundamental level, the MF - cell interaction is affected by the two broken symmetries: (a) left-right (LR) asymmetry of the MF and (b) chirality of DNA molecules carrying electric charges and subjected to the Lorentz force when moving in a MF. Here we report on the chirality-driven effect of static magnetic fields (SMFs) on DNA synthesis. This newly discovered effect reveals how the interplay between two fundamental features of symmetry in living and inanimate nature-DNA chirality and the inherent features of MFs to distinguish the left and right-manifests itself in different DNA synthesis rates in the upward and downward SMFs, consequently resulting in unequal cell proliferation for the two directions of the field. The interplay between DNA chirality and MF LR asymmetry will provide fundamental knowledge for many MF-induced biological phenotypes.

• Klíčová slova
• DNA synthesis, biomagnetic effects, homochirality, left-right asymmetry, magnetic field,
• Publikační typ
• časopisecké články MeSH