Two cerebral infarctions caused by thrombus and myxomatous embolus in a patient with cardiac myxoma: A case report.

An increasing number of cases of cerebral embolism caused by cardiac myxoma have been reported. However, cerebral infarction caused by different types of emboli obstructing different vascular regions within a short period of time has not been reported. This is the first report to histologically confirm cerebral infarctions independently caused by thrombus and myxomatous embolus in a patient with cardiac myxoma within a period of 23 days. The first cerebral infarction was due to embolization of thrombus to the right middle cerebral artery, whereas the second was due to embolization of tissue from a mucinous tumor to the left middle cerebral artery. Both cerebral infarctions underwent mechanical thrombectomy, but unfortunately, we ultimately failed to save the patient's life. Therefore, further attention should be paid to the surgical resection and treatment of cardiac myxoma.

Genetic influence of Apolipoprotein E gene ε2/ε3/ε4 isoforms on odds of mesial temporal lobe epilepsy.

OBJECTIVE: The potential correlation between the ε2/ε3/ε4 variants of the ApoE (Apolipoprotein E) gene and the odds of mesial temporal lobe epilepsy was investigated. METHODS: The database searching for eligible studies was performed in October 2020. A series of pooling analyses were conducted. RESULTS: We enrolled a total of twelve case-control studies for pooling. Within the pooling analysis of ε4, there was an increased risk of mesial temporal lobe epilepsy in cases under the models of carrier ε4 vs. ε3, ε3ε4 vs. ε3ε3, and ε3ε4+ε4ε4 vs. ε3ε3 [P < 0.05, odds ratio (OR) > 1], compared with controls. Moreover, we observed similar positive results in the subgroup analyses of "China" and "Population-based control" under the genetic models of ε4 (P < 0.05, OR > 1). Nevertheless, we did not detect the significant difference between the mesial temporal lobe epilepsy cases and controls in the pooling analyses of ε2 (all P > 0.05). CONCLUSION: The ε3ε4 genotype of ApoE seems to be linked to the risk of mesial temporal lobe epilepsy for patients in China. More sample sizes are required to confirm the potential role of ApoE isoforms in the susceptibility to diverse types of epilepsy from different origins.

Conferring thermotolerant phenotype to wild-type Yarrowia lipolytica improves cell growth and erythritol production.

In microbial engineering, heat stress is an important environmental factor modulating cell growth, metabolic flux distribution and the synthesis of target products. Yarrowia lipolytica, as a GARS (generally recognized as safe) nonconventional yeast, has been widely used in the food industry, especially as the host of erythritol production. Biomanufacturing economics is limited by the high operational cost of cooling energy in large-scale fermentation. It is of great significance to select thermotolerant Y. lipolytica to reduce the cooling cost and elucidate the heat-resistant mechanism at molecular level. For this purpose, we performed adaptive evolution and obtained a thermotolerant strain named Y. lipolytica BBE-18. Transcriptome analysis allows us to identify four genes in thiamine metabolism pathway that are responsible for the complicated thermotolerant phenotype. The heat-resistant phenotype was validated with the model strain Y. lipolytica Po1f by overexpression of single and combined genes. Then, conferring the thermotolerant phenotype to the wild-type Y. lipolytica BBE-17 enable the strain to produce three-times more erythritol of the control strain with 3°C higher than optimal cultivation temperature. To our knowledge, this is the first report on engineering heat-resistant phenotype to improve the erythritol production in Y. lipolytica. However, due to the increase of culture temperature, a large amount of adenosine triphosphate is consumed to ensure the life activities of Y. lipolytica which limits the potential of cell synthetic products to a certain extent. Even so, this study provides a reference for Y. lipolytica to produce other products under high temperature.

Long-term oral melatonin alleviates memory deficits, reduces amyloid-ß deposition associated with downregulation of BACE1 and mitophagy in APP/PS1 transgenic mice.

Melatonin is a tryptophan metabolite synthesized by the pineal gland. Recent research showed that melatonin has a protective effect in Alzheimer's disease (AD). However, its exact mechanism is still unclear. This study was designed to investigate the effects of long-term oral melatonin on spatial learning and memory, Aß deposition and soluble Aß levels, amyloidogenic amyloid precursor protein (APP) processing, mitochondrial structure and mitophagy in APP/PS1 transgenic mice, a model of AD. The spatial learning and memory ability of mice were examined by using the Morris water maze. Thioflavin S staining was used to observe Aß deposition. ELISA was used to evaluate the levels of Aß40 and Aß42. The expression levels of mitophagy proteins (PINK1, Parkin, LC3-II and LC3-I) and amyloidogenic APP processing proteins (BACE1, APP and CTFß) were examined by western blotting analysis. Finally, transmission electron microscopy was used to observe mitochondrial structure and mitophagy vesicles. Our results showed that APP/PS1 transgenic mice with long-term oral melatonin showed improved spatial learning, alleviated memory impairment, reduced Aß deposition and restrained damage of mitochondrial structure. In addition, the number of mitophagy vesicles and expression levels of mitophagy factors (PINK1, Parkin, LC3-II/LC3-I) were decreased, as was the expression levels of amyloidogenic APP processing proteins (BACE1, APP and CTFß). Long-term oral melatonin decreased Aß deposition and improved spatial learning and memory in APP/PS1 transgenic mice by a mechanism associated with down-regulation of BACE1 and mitophagy.

Combining genetically-encoded biosensors with high throughput strain screening to maximize erythritol production in Yarrowia lipolytica.

Erythritol is an important sweetener ingredient and chemical precursor for synthesizing materials with phase transition behavior. Commercial erythritol is primarily produced by industrial fermentation. Further strain engineering necessitates the development of high throughput screening method for rapid detection and screening of mutant strain libraries. In this work, we took advantage of the erythritol-responsive transcription factor EryD, and constructed a sensor-regulator system for rapid screening and characterization of erythritol overproducers. We configured the optimal architecture of the EryD sensor-regulator construct with improved sensitivity, specificity and dynamic response range. Coupled with mutagenesis and strain screening based on biosensors, we rapidly screened and characterized a strain library containing 1152 mutants derived from combined UV and ARTP mutagenesis, in a relatively short period of time (1 week). The optimal strain produced more than 148 g/L erythritol in bench-top reactors. This work provides a reference for other metabolic engineering researchers to develop industrially-relevant strains. The reported framework enables us to rapidly improve strain performance and engineer efficient microbial cell factories for industrial applications.

Stress tolerance phenotype of industrial yeast: industrial cases, cellular changes, and improvement strategies.

Yeast is widely used in the baking, biocontrol, brewing, and bio manufacturing industries. In the baking industry alone, around two million tons of yeast are consumed worldwide every year. While yeast brings delicious and healthy lives to humans, we find that stress resistance of yeast is essential for the development of bioindustry. Whether during baking, biocontrol, brewing, bio manufacturing, or in other industries, yeast faces a variety of environmental stresses that have a great impact on its activity, transformation ability, etc., which make the production process uncertain. Therefore, robust yeast strains that can resist various environmental and endogenous stresses are needed. In recent years, many studies have investigated the stress resistance of laboratory strains and specific methods to improve stress resistance; however, applying these findings to industrial yeast is difficult. In this paper, based on summarizing the work of predecessors, we put forward the main steps to improve the stress resistance of industrial yeast systematically, which may provide a reference for researchers.

Stimulatory effects of amino acids on γ-polyglutamic acid production by Bacillus subtilis.

This paper is about study to increase the γ-PGA yield by developing new methods. The effect of various amino acids on production of γ-PGA by Bacillus subtilis Z15 was investigated. The γ-PGA yield was increased 23.18%, 12.15% and 31.46%, respectively, with 3 g/L aspartic acid (0 h), 1.5 g/L phenylalanine (0 h) and 7 g/L glutamic acid (24 h). Additonally, crude extract of glutamic acid after isoelectric crystallization (CEGA)could be a replacement for glutamate for γ-PGA production. Then, response surface methodology (RSM) was used for further optimization. The final media ingredient of amino acids were obtained as follow: CEGA 9 g/L, aspartic acid 4 g/L, phenylalanine 1.55 g/L. By applying this receipt in 5-L bioreactor, the γ-PGA yield reached 42.92 ± 0.23 g/L after 44 h, which is 63.1% higher than the control without amino acids for production. In addition, amino acids could shorten the lag phase and the average fermentation time (44 h versus 48 h). Fermentation with amino acids addition can be an positive option for γ-PGA production.

A novel cleaning process for industrial production of xylose in pilot scale from corncob by using screw-steam-explosive extruder.

Steam explosion is the most promising technology to replace conventional acid hydrolysis of lignocellulose for biomass pretreatment. In this paper, a new screw-steam-explosive extruder was designed and explored for xylose production and lignocellulose biorefinery at the pilot scale. We investigated the effect of different chemicals on xylose yield in the screw-steam-explosive extrusion process, and the xylose production process was optimized as followings: After pre-impregnation with sulfuric acid at 80 °C for 3 h, corncob was treated at 1.55 MPa with 9 mg sulfuric acid/g dry corncob (DC) for 5.5 min, followed by countercurrent extraction (3 recycles), decoloration (activated carbon dosage 0.07 g/g sugar, 75 °C for 40 min), and ion exchange (2 batches). Using this process, 3.575 kg of crystal xylose was produced from 22 kg corncob, almost 90 % of hemicellulose was released as monomeric sugar, and only a small amount of by-products was released (formic acid, acetic acid, fural, 5-hydroxymethylfurfural, and phenolic compounds were 0.17, 1.14, 0.53, 0.19, and 1.75 g/100 g DC, respectively). All results indicated that the screw-steam-explosive extrusion provides a more effective way to convert hemicellulose into xylose and could be an alternative method to traditional sulfuric acid hydrolysis process for lignocellulose biorefinery.