Quantitative analysis of microglia morphological changes in the hypothalamus of chronically stressed rats.

Based on the successful establishment of a rat model of chronic restraint stress, we used multiple algorithms to quantify the morphological changes of rat hypothalamic microglia from various perspectives, providing a pathomorphological basis for the subsequent study of molecular mechanisms of hypothalamic stress injury, such as neuroinflammation. To verify the successful establishment of the chronic stress model, an enzyme-linked immunosorbent assay was performed to detect serum glucocorticoid levels. Microglia labeled with Iba1 in frozen sections of rat hypothalamus were scanned and photographed at multiple levels using confocal microscopy. Subsequently, images were processed for external contouring and skeletonization, and morphological indices of microglia were calculated and analyzed using fractal, skeleton, and Sholl analysis. In addition, the co-expression of CD68 (a marker that can reflect phagocytic activity) and Iba1 was observed by immunofluorescence technique. Compared with the control group, microglia in the chronic stress group displayed reduced fractal dimension and lacunarity, increased density and circularity, enlarged soma areas, and shortened and reduced branches. Sholl analysis confirmed the reduced complexity of microglia following chronic stress. Meanwhile, microglia CD68 increased significantly, indicating that the microglia in the chronic stress group have greater phagocytosis activity. In summary, chronic restraint stress promoted the conversion of microglia in the rat hypothalamus to a less complex form, manifested as larger soma, shorter and fewer branches, more uniform and dense texture, and increased circularity; indeed, the shape of these microglia resembled that of amoeba and they displayed strong phagocytosis activity.

Case report: Myocarditis following COVID-19 protein subunit vaccination.

We report findings in a 34-year-old female patient who presented with fulminant myocarditis 8 days after receiving the first dose of the ZF2001 RBD-subunit vaccine against coronavirus disease 2019 (COVID-19). Autopsy showed severe interstitial myocarditis, including multiple patchy infiltrations of lymphocytes and monocytes in the myocardium of the left and right ventricular walls associated with myocyte degeneration and necrosis. This report highlights the details of clinical presentations and autopsy findings of myocarditis after ZF2001 (RBD-subunit vaccine) vaccination. The correlation between vaccination and death due to myocarditis is discussed.

Research on preparation of phosphate-modified animal glue binder for foundry use.

In this paper, three phosphates were used as modifiers to modify animal glue binder. The structural characteristics and thermal properties of animal glue binder treated with phosphates were studied by Fourier transform-infrared spectroscopy, gel permeation chromatography and derivative thermogravimetric analysis. The results showed that the modified animal glue binder had better sand tensile strength and lower viscosity than untreated animal glue binder. The best modification process was as follows: the optimal amount of sodium carbonate was 4 wt% to animal glue; the optimal weight ratio of the modifiers was sodium pyrophosphate : sodium tripolyphosphate : sodium hexametaphosphate : animal glue = 3 : 3 : 4 : 100, and the optimal reaction should be performed at 80°C for a reaction time of 120 min. A final tensile strength of approximately 3.20 MPa was achieved and the viscosity value was approximately 880 mPa s.

Restraint stress aggravates rat kidney injury caused by a crush injury through endoplasmic reticulum stress.

BACKGROUND: The present study aimed to determine whether restraint stress aggravates kidney injury caused by a crush injury through endoplasmic reticulum stress (ERS). METHODS: In this study, Sprague-Dawley rat restraint stress, crush injury, and stressful injury models consisting of restraint stress and crush injury were established. An ERS inhibitor, Salubrinal (Sal), was administered intraperitoneally 30 minutes before induction of daily injury in the stressful injury group. At the end of the experimental procedures, plasma levels of noradrenaline and adrenaline, creatine phosphokinase, creatinine, and blood urea nitrogen were measured. Kidneys were harvested, and paraffin-embedded sections of kidney tissues were processed for hematoxylin-eosin staining and TUNEL assay to verify pathologic changes. Western blot was used to determine the protein levels of glucose-regulated protein 78, CCAAT/enhancer-binding protein-homologous protein, caspase 12, caspase 3, and MCP-1 in kidney specimens. RESULTS: Compared with crush injury, the most significant changes in kidney injury occurred in the stressful injury group, which was inhibited by Sal. The results suggested that restraint stress aggravates kidney injury caused by a crush injury, and the mechanism might involve ERS. Further study showed that double attacks induced a significant increase in the levels of glucose-regulated protein 78, CCAAT/enhancer-binding protein-homologous protein, caspase 12, and caspase 3, which was inhibited by Sal. The same changes were observed using the TUNEL assay. Double attacks also induced an increased expression of the proinflammatory cytokine, MCP-1, which was inhibited by Sal. CONCLUSION: Apoptosis and inflammation induced by ERS are important mechanisms by which restraint stress aggravates kidney injury caused by a crush injury.

[Effects of megsin gene transfection on the expressions of MCP-1 and ICAM-1 in mouse glomerular mesangial cells].

AIM: To observe the effects of megsin gene transfection on the expressions of monocyte chemoattractant protein-1 (MCP-1) and intercellular adhesion molecule-1(ICAM-1). METHODS: Mouse glomerular mesangial cells were cultured in high glucose medium, and then cell proliferation was measured by MTT assay at 12, 24 and 48 h respectively. The expressions of megsin, MCP-1 and ICAM-1 in mesangial cells were detected by immunocytochemical staining and Western blotting. The concentration of type IV collagen in the culture supernatant of mesangial cells was measured by ELISA. RESULTS: Under high glucose concentration, the expressions of megsin, MCP-1 and ICAM-1 increased; the concentration of type IV collagen in the cell supernatant was elevated as well; and mesangial cell proliferation was enhanced. After megsin gene transfection, the above changes were more significant, but were abated following megsin shRNA/transfection. CONCLUSION: Megsin gene can up-regulate the expressions of MCP-1 and ICAM-1, promote mesangial cell proliferation and mesangial extracellular matrix accumulation.

A method to measure the frequencies of individual half cells in a dumbbell cavity.

Dumbbell fabrication is a midprocess for manufacturing an elliptical superconducting rf cavity. In order to understand how a welding shrinkage affects a dumbbell's frequencies and length, we need to measure the exact frequencies of each individual half cell of a dumbbell. To improve such a calculation precision and to simplify the calculation formulae, based on a two-coupled oscillator model and a cavity perturbation theory, a new formula to calculate the individual half-cell frequencies of a dumbbell or the individual cavity frequencies of a two-cavity coupling system has been developed, and its performance has been confirmed by using a dumbbell simulation. This formula can be applied to any kind of rf cavities with electric, magnetic, or electromagnetic coupling, if a coupling hole between two coupling cavities is small compared to the wavelength. Compared to other calculation formulae, this formula simplifies the calculation process of the individual resonator frequencies of a coupling system considerably, and it can also improve the calculation precision than that of a normal calculation method. Another advantage of this new method is that we do not need to consider a coupling factor between two resonators during a testing for an individual resonator frequency of an oscillator. The developed formula has been successfully used to tune the PEFP dumbbells.

[Effects of puerarin on renal function, expressions of MMP-2 and TIMP-2 in diabetic rats].

AIM: To investigate the effect of puerarin on expressions of MMP-2 and TIMP-2 in the kidney of diabetic rats. METHODS: Uninephrectomized male Wistar rats were used to induce diabetes by intraperitoneal injection of streptozocin (65 mg x kg(-1)). Puerarin was given daily by intraperitoneal injection from the third day of induction of diabetes for 16 weeks. Using in situ hybridization and immunohistochemistry to detect MMP-2, TIMP-2 mRNA expressions and MMP-2, TIMP-2, collagen IV and Laminin expressions in diabetic kidneys with image analysis system, Flow cytometry was used to detect the expressions of TGFbeta1, MMP-2 and TIMP-2. RESULTS: Compared with those in kidneys of control group, expressions of MMP-2 mRNA and proteins were lower, while the expressions of both TGFbeta1 and TIMP-2 were higher in the diabetic kidney (P < 0.05). The level of MMP-2 expression was advanced, while expression of TIMP-2 was reduced by puerarin treatment (P < 0.05). CONCLUSION: Puerarin showed some renal protective effect on diabetic nephropathy, partly through inhibition of excessive deposition of glomeruli extracellular matrix by up-regulating MMP-2 and down-regulating TIMP-2 expressions besides reducing the blood glucose.

[Change of vascular endothelial growth factor and its receptors expression in acute myeloid leukemia before and after treatment].

OBJECTIVE: To explore the role of angiogenesis in bone marrow in acute myeloid leukemia (AML). METHODS: Bone marrow culture supernatant was assayed for vascular endothelial growth factor (VEGF) by ELISA, bone marrow biopsies from 28 newly diagnosed AML patients were assayed for microvessel density (MVD), VEGF and its receptors KDR, Flt-1 by immunohistochemical staining before and after induction chemotherapy. RESULTS: Culture supernatant of AML bone marrow mononuclear cells showed higher amount of VEGF (425.31 ng/L) than that of control (140.12 ng/L). The VEGF and KDR expressions and MVD were significantly higher in newly diagnosed AML patients (78.6%, 78.6% and 7.1%, respectively) than that of control group (P < 0.05). There was a positive correlation between VEGF, KDR and MVD. The positive rate of VEGF, KDR and MVD reduced to normal after the patients achieved complete remission, while in non-remission patients did not. Kaplan-Meier analysis showed that the survival time was longer in VEGF negative group than in VEGF positive group. The pre-treatment MVD and VEGF had no correlation with survival time. CONCLUSIONS: There is remarkable angiogenesis in AML and VEGF/KDR signaling pathway takes an important role in the pathological angiogenesis. VEGF could be used as a prognostic factor in AML.

[Effects of benazepril on apoptosis in the kidney of diabetic rats].

AIM: To investigate the effects of angiotensin converting enzyme inhibitor (ACEI) on apoptosis and the expression of Fas and Fas-L in the kidney of diabetic rats. METHODS: Uninephrectomized Spraque-Dawley rats were used to induce diabetes by intraperitoneal injection of streptozotocin (65 mg.kg-1). Benazepril (10 mg.kg-1) was given daily by gavage from the next day of the induction to diabetes for 12 weeks. Apoptosis was evaluated by means of terminal-deoxynucleotidyl transferase mediated d-UTP nick end labeling (TUNEL). Flow cytometry and immunohistochemistry were used to detect the expression of Fas and Fas-L. RESULTS: Compared with those in the kidneys of control group, apoptotic cells were more in number and the expression of Fas and Fas-L was higher in the diabetic kidneys (P < 0.05). The number of apoptotic cells and the level of expression of Fas and Fas-L were reduced by benazepril treatment (P < 0.05). CONCLUSION: Angiotensin converting enzyme inhibitor benazepril showed some renal protective effect on diabetic nephropathy, partly through inhibiting apoptosis by down-regulating Fas and Fas-L expression.