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.

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.