The amino acid metabolomics signature of differentiating myocardial infarction from strangulation death in mice models.

This study differentiates myocardial infarction (MI) and strangulation death (STR) from the perspective of amino acid metabolism. In this study, MI mice model via subcutaneous injection of isoproterenol and STR mice model by neck strangulation were constructed, and were randomly divided into control (CON), STR, mild MI (MMI), and severe MI (SMI) groups. The metabolomics profiles were obtained by liquid chromatography-mass spectrometry (LC-MS)-based untargeted metabolomics. Principal component analysis, partial least squares-discriminant analysis, volcano plots, and heatmap were used for discrepancy metabolomics analysis. Pathway enrichment analysis was performed and the expression of proteins related to metabolomics was detected using immunohistochemical and western blot methods. Differential metabolites and metabolite pathways were screened. In addition, we found the expression of PPM1K was significantly reduced in the MI group, but the expression of p-mTOR and p-S6K1 were significantly increased (all P < 0.05), especially in the SMI group (P < 0.01). The expression of Cyt-C was significantly increased in each group compared with the CON group, especially in the STR group (all P < 0.01), and the expression of AMPKα1 was significantly increased in the STR group (all P < 0.01). Our study for the first time revealed significant differences in amino acid metabolism between STR and MI.

CCK1R2R-/- ameliorates myocardial damage caused by unpredictable stress via altering fatty acid metabolism.

The heart is the main organ of the circulatory system and requires fatty acids to maintain its activity. Stress is a contributor to aggravating cardiovascular diseases and even death, and exacerbates the abnormal lipid metabolism. The cardiac metabolism may be disturbed by stress. Cholecystokinin (CCK), which is a classical peptide hormone, and its receptor (CCKR) are expressed in myocardial cells and affect cardiovascular function. Nevertheless, under stress, the exact role of CCKR on cardiac function and cardiac metabolism is unknown and the mechanism is worth exploring. After unpredictable stress, a common stress-inducing model that induces the development of mood disorders such as anxiety and reduces motivated behavior, we found that the abnormal contraction and diastole of the heart, myocardial injury, oxidative stress and inflammation of mice were aggravated. Cholecystokinin A receptor and cholecystokinin B receptor knockout (CCK1R2R-/-) significantly reversed these changes. Mechanistically, fatty acid metabolism was found to be altered in CCK1R2R-/- mice. Differential metabolites, especially L-tryptophan, L-aspartic acid, cholesterol, taurocholic acid, ADP, oxoglutaric acid, arachidonic acid and 17-Hydroxyprogesterone, influenced cardiac function after CCK1R2R knockout and unpredictable stress. We conclude that CCK1R2R-/- ameliorated myocardial damage caused by unpredictable stress via altering fatty acid metabolism.

Abnormal fatty acid metabolism and ceramide expression may discriminate myocardial infarction from strangulation death: A pilot study.

Determining myocardial infarction (MI) and mechanical asphyxia (MA) was one of the most challenging tasks in forensic practice. The present study aimed to investigate the potential of fatty acid (FAs) metabolism, and lipid alterations in determining MI and MA. MA and MI mouse models were constructed, and metabolic profiles were obtained by LC-MS-based untargeted metabolomics. The metabolic alterations were explored using the PCA, OPLS-DA, the Wilcoxon test, and fold change analysis. The contents of lipid droplets (LDs) were detected by the transmission scanning electron microscope and Oil red O staining. The immunohistochemical assay was performed to detect CD36 and dysferlin. The ceramide was assessed by LC-MS. PCA showed considerable differences in the metabolite profiles, and the well-fitting OPLS-DA model was developed to screen differential metabolites. Thereinto, 9 metabolites in the MA were reduced, while metabolites were up- and down-regulated in MI. The increased CD36 suggested that MI and MA could enhance the intake of FAs and disturb energy metabolism. The increased LDs, decreased dysferlin, and increased ceramide (C18:0, C22:0, and C24:0) were observed in MI groups, confirming the lipid deposition. The present study indicated significant differences in myocardial FAs metabolism and lipid alterations between MI and MA, suggesting that FAs metabolism and related proteins, certain ceramide may harbor the potential as biomarkers for discrimination of MI and MA.

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.

[Cardiac Ultrastructure and Changes of HSP70 and HIF-1α Expression in Electric Shock Death Rats].

OBJECTIVE: To observe cardiac ultrastructure and the expression of heat shock protein 70 (HSP70) and hypoxia inducible factor-lα (HIF-lα) in electric shock death rats and to explore the application of these indexes as the basis of medical identification in electric shock death. METHODS: Seventy-two SD rats were randomly divided into electric shock death group, postmortem electric shock group and the control group. The changes of myocardial ultrastructure were observed by transmission electron microscope, and the expressions of myocardial HSP70 and HIF-1α were observed by immunohistochemical technology. RESULTS: Myocardial myofibril fracture, mitochondrial cristae and membrane dissolution, and disordered arrangement of Z lines and M lines were observed in electric shock rats. HSP70 and HIF-lα were strong positive expressions in the electric shock death group, significantly compared with the control and postmortem electric shock groups (P < 0.05). CONCLUSION: The expressions of HSP70 and HIF-lα were obviously increased in electric shock death group, which may be used as the diagnostic indicator of electric shock death.

[The structure, shape, spectral characteristics and photochemical reaction of nano Eu : CaWO4].

The samples were pretreated by controlling PH in the process of Pechini, and after sintering and grind, the nano Eu-doped tungstate with different granularity was obtained in the result. The structure was characterized by XRD, and the diffuse scattering spectra and the crystal microstructure were characterized by HRTEM and spectrometer. It was found from high efficient decomposition of rhodamine that the nano-materials obtained have good catalytic effect of light.

[Determination of nutrient fungus dietary fiber and structural characterization].

The simultaneous determination of trace elements in ultrafine agaric was carried out by inductively coupled plasma atomic emission spectrometry (ICP-AES). The experiments were done using wet acid digestion sample preparation. The samples were dissolved at 120 degrees C constant temperature. The requirements of determination by ICP-AES can be satisfied at an acidity controlled less than 10%. The method is simple, rapid and economic. National standard material GBW07602 was detected by authentication. Its accuracy is between 1.12% and 6.15. The precision is between 0.41% and 5.69%. At thesame time, the surface structure of ultrafine agaric powder was examined by scanning electron microscope. And the dietary fiber was determined for fungus protein, crude fat, crude fiber, moisture and ash content by chemical analysis. The study on external and internal relevance of agaric could provide a new approach to scientific research on the development and application of fungus dietary fiber.

[Study of microelements in plant's ash and environmental soil by microwave digestion ICP-AES].

A model MDS-2002A microwave digestion sample preparation system with auto control pressure in obturation was developed for the determination of microelements in clearing-up plant's ash and environment soil sample by ICP-AES. The authors discussed sample preparation result influenced by mixed acid system, scale of mixed acid dispensation, proportion between solid and liquid and time of microwave clearing. Excellent project was A2B1C2, work procedure 2 in microwave process. When the dispensation scale was 6 : 2 : 1 : 1 and mixed acid system was HNO3-HCl-HF-HClO4, the result was the best in 10 min of microwave clearing at highest power. The reagent was dried at constant temperature electric heating board, with its salinity being dissolved by aqua fortis. The method was validated through the soil (GBW07401) and plant (GBW07603) for national standard matter. The relative error of its result is between 0.00% and 7.14%, and the relative standard deviation is between 0.87% and 5.25%. The method is quick, handy, saving reagent and completely digesting in dealing with plant's ash and soil sample, and the accuracy and precision of results are satisfying.

[Study of the elements determination method in animal fur by microwave digestion ICP-AES].

Considering the complex matrix of the sample, the animal fur is carried on to the sample pretreatment method studies specially. The microwave closed system has its unique merit: The microwave radiation has the very strong penetrability and the rapid in-depth heating function. After absorbing microwave the sample and the molecules of reactant may carry on the reaction in short time. But the microwave power is very weak, reaction consumes much time, the resolution is also incomplete. Besides the output excessively is high dispels in the pot the reagent differential pressure to increase the test solution to produce the storm rapidly to boil. As a result of those flaws, the minute step microwave heating digestion method is used to digest test specimen after treated by the acid pickling over night. In the experiment, the specialized microwave reactor is replaced by civil microwave; the microwave heating technology is adopted. According to the different characteristics of reagents, different allocated proportion and the test solution volume of nitric acid, hydrogen peroxide, hydrochloric acid and the water are tested separately. Meanwhile, in order to optimize the experimental condition, the different response power and respond time is also studied. At last, the experimental condition is determined: HNO3-H2O2-HCl-H2O acid system is chose(four reagent allocated proportions are 8:1:1:5); test specimen is heated up 10 minutes when the output is 150 W and 5 minutes when the output is 360 W continuously; carries on the test specimen airtight resolution processing animal fur by the sample. To guarantee the standard solution system is consistent with the biological sample substrate, the artificial simulation biology sample substrate is used to match law configuration standard solution; the ration the substrate element calcium is added. To eliminate disturbance of the sample complex substrate, the substrate match law, which reduces the substrate element disturbance is used. Inductive coupling plasma atom emission spectral analysis technology is also adopted in the experiment. This method has several advantages: the rapidity of the examination, the scope width of the examination, low consumption of test specimens and low limitation of picking out. This method is able to simultaneously examine the aluminum, the iron, the calcium, the magnesium, the boron, the barium, the cadmium, the cobalt, the copper, the chromium, the manganese, the molybdenum, the nickel, the phosphorus, the lead, the strontium, the zinc, the titanium, 18 kind of constants and trace element existed in the animal fur. There kinds of animal furs were examined. Basically, the constants of calcium were close. The content of magnesium and strontium in the furs of the herbivorous were higher than the omnivorous and the carnivorous, while the content of phosphorus in the furs of the herbivorous was lower than the other tow, so did the trace element, namely aluminum, iron, copper, zinc. It was obvious that only in the fur of the carnivorous was the content trace element titanium included. Based on the examination result, we could draw the conclusion that contain connection, which may explain the intrinsic and the external relationship concerning the animal, exists between the animal habit and the element content in their body. This method sends the standard material GBW07601 confirmation after the national person, obtains the method relative error in between 0.83%-9.59%, the relatively standard deviation between 0.81%-5.20%. The limitation of picking out, the accuracy and the accuracy each examination target is obtained in the animal fur by the actual sample analysis in the confirmation, which can satisfy the biological sample examination request.

[Dynamic changes of LDH and HBDH activity in rabbit serum after low voltage electrical injury].

OBJECTIVE: To investigate changes of LDH and HBDH activity in rabbit serum after non-thermal low voltage electrical injury and to provide diagnostic criteria for non-thermal low voltage electrical injury. METHODS: Forty New Zealand rabbits were randomly distributed into control group and electrical injury group (EI-groups; designated 7 time points: 0 h, 2 h, 4 h, 12 h, 1 d, 2 d, 3 d), 5 rabbits per each group. EI-groups were treated with the method of non-thermal low voltage electrical injury established in our laboratory. Ventricular blood (5 mL) was obtained under anesthesia at designated time points after electrical injury. The activities of LDH and HBDH were measured. RESULTS: Dynamic changes were observed with certain patterns from target serum enzyme activities after electrical injury. Compared with control group, the activities of LDH increased markedly at 4 h, 12 h, and on days 1, 2, and 3 after injury (4 h, 12 h, and day 1 P<0.01; day 2 and day 3 P<0.05). Activities of HBDH increased markedly at day 2 and day 3 after injury (P<0.05). The ratio of HBDH/LDH decreased markedly at 2 h, 4 h, and 12 h after injury (P<0.01). CONCLUSION: Dynamic changes of LDH and HBDH activities may be useful in diagnosis of non-thermal low voltage electrical injury and in estimation of post injury intervals.

[Determination of trace elements in natural grapestone by inductively coupled plasma atomic emission spectrometry].

Determination of trace elements in natural grapestone was studied by inductively coupled plasma atomic emission spectrometry (ICP-AES). Comparison was made between dry incineration and acid clearing up in terms of interference of organic component in natural grapestone. By analyzing the plant standard substance GBW 07603(National Standard Substance), the data show that HNO3-HClO4 disposed samples are better than dry incinerated ones. The accuracy is 1. 06-8. 82, the precision is 1. 35%-8. 88%. The comparative experiment of trace elements determination was carried out for grapestone and herbs. The data show that grapestone is valuable for medicine and nutrition.

[Determination of rare earth and microelements in Chinese herbal medicine by inductively coupled plasma mass spectrometry].

In this article, through the condition experiment of simultaneous determination of rare earth and trace elements in wolfsbane by inductively coupled plasma mass spectrometry (ICP-MS), the methods of low temperature ashing and nitric acid-overoxidation hydrogen (HNO3-H2O2) were compared. It was proved that the sample disposed with low temperature ashing for microelements and the sample disposed with acid digestion for rare earth satisfied the request for the method of determination. The accuracy is between 1.21% and 15.15%, and the precision is between 0.38% and 8.54%. The data of the experiment proved that the method completely satisfied the request for the determination of rare earth and microelements in the sample of Chinese herbal medicine.

[Determination of rare-earth and trace elements in teeth enamel by inductively coupled plasma mass spectroscopy].

Determination of rare earth and trace elements in teeth enamel was studied by inductively coupled plasma mass spectroscopy. The sample was completely dissolved by HNO3-H2O2. The range of precision is 0.50%-6.79% given by the relative standard deviation and the range of accuracy is 94.45%-104.78% obtained by measuring standard recovery rate. The above data satisfied completely the requirements of biological sample. While this study provides experimental data of rareearth and trace elements of teeth enamel for carious teeth and none carious teeth of human for prevention and cure of decayed tooth. A reasonable method is provided for mouth medicine research.

[Study on the determination of microelements in forest frog by inductively coupled plasma atomic emission spectroscopy].

In this paper, several trace elements in the forest frog samples were investigated by inductively coupled plasma atomic emission spectrometry (ICP-AES). During the experiment 5.00 mL HNO3 and 0.50 mL HClO4 were added to the sample, which then remained 24 hours before being heated to 120 degrees C and solved. This method can not only meet the requirement of ICP-AES, but also has many merits, such as simplicity, rapidity, precision and economy. The range of relative error was 0.17%-10.0% and the range of precision was 0.43%-9.96% for these elements.