Artificial switches induce the bespoke production of functional compounds in marine microalgae Chlorella by neutralizing CO2.

To improve the CO2 tolerance of a marine microalga Chlorella sp. of which the production capacity has been demonstrated industrially, a mutant library was created and a strain hct53 was screened. Compared to the parental strain, hct53 shows a high CO2 capture capacity, while starch biosynthesis is compromised, with increases in health beneficial metabolites and antioxidant capacity. Global gene expression and genome-wide mutation distribution revealed that transcript choreography was concomitant with more active CO2 sequestration, an increase in the lipid synthesis, and a decrease in the starch and protein synthesis. These results suggest that artificial trait improvement via mutagenesis, couple with multiomics analysis, helps discover genetic switches that induce the bespoke conversion of carbon flow from "redundant metabolites" to valuable ones for functional food.

Risk factors for stroke in a population of central China: A cross-sectional study.

The incidence and mortality rates of stroke in China are higher than the world average, seriously endangering the public's health and quality of life. It is important to predict the incidence of stroke, identify the high-risk factors in the region, and raise the risk awareness of high-risk groups. This study sought to investigate and analyze the distribution of stroke population and the main risk factors for stroke occurrence in a Chinese population, and to predict the probability of stroke occurrence in high-risk groups with risk factors, so as to provide a scientific basis for the comprehensive prevention and treatment of stroke. A whole-group sampling method was used to investigate 1009 participants in Jingzhou city in central China, and a uniform questionnaire survey and related medical examinations were conducted. The risk factors for stroke in the area were analyzed by univariate analysis, and a multifactorial logistic regression prediction model was established based on the results of univariate analysis. The results of univariate and multifactorial logistic regression analyses suggested that gender, age, family history of stroke, hypertension, atrial fibrillation, diabetes, and sedentary lifestyle were significantly associated with an increased risk of stroke in the local population (all P < .05). The top 5 risk factors for stroke were atrial fibrillation (odds ratio [OR] = 5.225, 95% confidence interval [CI]: 2.826-9.663), sedentary lifestyle (OR = 2.701, 95% CI: 1.667-4.376), age (≥65 years) (OR = 2.593, 95% CI: 1.680-4.004), hypertension (OR = 2.106, 95% CI: 1.380-3.216), and gender (male) (OR = 2.099, 95% CI: 1.270-3.471). This study effectively identifies the high risk factors for stroke and provides scientific insights for risk assessment, intervention of risk factors, and decision making of health management departments in the central region of China. The modifable risk factors for stroke such as smoking, hypertension, atrial fibrillation, diabetes mellitus, and sedentary lifestyle were also observed. Our findings further highlight the significant of the primary and secondary prevention for stroke and reveal the potential targets to reduce the heavy stroke burden in China around the world.

Microalgal photoautotrophic growth induces pH decrease in the aquatic environment by acidic metabolites secretion.

BACKGROUND: Microalgae can absorb CO2 during photosynthesis, which causes the aquatic environmental pH to rise. However, the pH is reduced when microalga Euglena gracilis (EG) is cultivated under photoautotrophic conditions. The mechanism behind this unique phenomenon is not yet elucidated. RESULTS: The present study evaluated the growth of EG, compared to Chlorella vulgaris (CV), as the control group; analyzed the dissolved organic matter (DOM) in the aquatic environment; finally revealed the mechanism of the decrease in the aquatic environmental pH via comparative metabolomics analysis. Although the CV cell density was 28.3-fold that of EG, the secreted-DOM content from EG cell was 49.8-fold that of CV (p-value < 0.001). The main component of EG's DOM was rich in humic acids, which contained more DOM composed of chemical bonds such as N-H, O-H, C-H, C=O, C-O-C, and C-OH than that of CV. Essentially, the 24 candidate biomarkers metabolites secreted by EG into the aquatic environment were acidic substances, mainly lipids and lipid-like molecules, organoheterocyclic compounds, organic acids, and derivatives. Moreover, six potential critical secreted-metabolic pathways were identified. CONCLUSIONS: This study demonstrated that EG secreted acidic metabolites, resulting in decreased aquatic environmental pH. This study provides novel insights into a new understanding of the ecological niche of EG and the rule of pH change in the microalgae aquatic environment.

Euendolithic Cyanobacteria and Proteobacteria Together Contribute to Trigger Bioerosion in Aquatic Environments.

Shellfish, mussels, snails, and other aquatic animals, which assimilate limestone (calcium carbonate, CaCO3) to build shells and skeletons, are effective carbon sinks that help mitigate the greenhouse effect. However, bioerosion, the dissolution of calcium carbonate and the release of carbon dioxide, hinders carbon sequestration process. The bioerosion of aquatic environments remains to be elucidated. In this study, the bioerosion of Bellamya spp. shells from the aquatic environment was taken as the research object. In situ microbial community structure analysis of the bioerosion shell from different geographical locations, laboratory-level infected culture, and validated experiments were conducted by coupling traditional observation and 16S rRNA sequencing analysis method. Results showed that bioeroders can implant into the CaCO3 layer of the snail shell, resulting in the formation of many small holes in the shell, which reduced the shell's density and made the shell fragile. Results also showed that bioeroders were distributed in two major phyla, namely, Cyanobacteria and Proteobacteria. Cluster analysis showed that Cyanobacteria sp. and two unidentified genera (Burkholderiaceae and Raistonia) were the key bioeroders. Moreover, results suggested that the interaction of Cyanobacteria and other bacteria promoted the biological function of "shell bioerosion." This study identified the causes of "shell bioerosion" in aquatic environments and provided some theoretical basis for preventing and controlling it in the aquatic industry. Results also provided new insights of cyanobacterial bioerosion of shells and microalgae carbon sequestration.

Deep Learning-Based Denoised MRI Images for Correlation Analysis between Lumbar Facet Joint and Lumbar Disc Herniation in Spine Surgery.

This work aimed to explore the relationship between spine surgery lumbar facet joint (LFJ) and lumbar disc herniation (LDH) via compressed sensing algorithm-based MRI images to analyze the clinical symptoms of patients with residual neurological symptoms after LDH. Under weighted BM3D denoising, Epigraph method was introduced to establish the novel CSMRI reconstruction algorithm (BEMRI). 127 patients with LDH were taken as the research objects. The BEMRI algorithm was compared with others regarding peak signal-to-noise ratio (PSNR) and structural similarity index (SSIM). Patients' bilateral LFJ angles were compared. The relationships between LFJ angles, lumbar disc degeneration, and LFJ degeneration were analyzed. It turned out that the PSNR and SSIM of BEMRI algorithm were evidently superior to those of other algorithms. The proportion of patients with grade IV degeneration was at most 31.76%. Lumbar disc grading was positively correlated with change grading of LFJ degeneration (P < 0.001). LFJ asymmetry was positively correlated with LFJ degeneration grade and LDH (P < 0.001). Incidence of residual neurological symptoms in patients aged 61-70 years was as high as 63.77%. The proportion of patients with severe urinary excretion disorders was 71.96%. Therefore, the BEMRI algorithm improved the quality of MRI images. Degeneration of LDH was positively correlated with degeneration of LFJ. Asymmetry of LFJ was notably positively correlated with the degeneration of LFJ and LDH. Patients aged 61-70 years had a high incidence of residual neurological symptoms after surgery, most of which were manifested as urinary excretion disorders.

Ultrahigh-cell-density heterotrophic cultivation of the unicellular green alga Chlorella sorokiniana for biomass production.

Heterotrophic cultivation of Chlorella has achieved commercial success, but the application of Chlorella biomass is still limited due to the high cost of biomass production. In this study, an effective and industrially scalable heterotrphic cultivation technology has been developed for a production strain Chlorella sorokiniana GT-1. Under the optimized culturing conditions, the ultrahigh biomass concentration of 271 and 247 g L-1 was achieved in 7.5 L bench-scale and 1000 L pilot-scale fermenters, respectively. Technoeconomic (TE) analysis indicated that the production cost of C. sorokiniana GT-1 could be reduced to $1601.27 per ton of biomass if the biomass concentration reached 200 g L-1 , which is 24.2% lower than that of the reported highest Chlorella biomass production through fermentation with the same TE model. Under the same growth conditions, the maximum biomass concentration of a low-starch mutant SLM2 was reduced to 93 g L-1 , which was 54% lower than that of the wild type, indicating the capabilities of C. sorokiniana GT-1 cells in accumulating large amounts of starch are essential for achieving the ultrahigh-cell-density under the heterotrophic conditions. In addition, the ultrahigh-cell-density growth potential of C. sorokiniana GT-1 cells was inferred to be related to the intrinsic biological characteristics including the tolerance to low dissolved oxygen and a moderate doubling time under the heterotrophic conditions as well. The breakthrough in cultivation technology is promising for Chlorella industry and would expand its applications in food and feed.

Water reuse and growth inhibition mechanisms for cultivation of microalga Euglena gracilis.

BACKGROUND: Microalgae can contribute to more than 40% of global primary biomass production and are suitable candidates for various biotechnology applications such as food, feed products, drugs, fuels, and wastewater treatment. However, the primary limitation for large-scale algae production is the fact that algae requires large amounts of fresh water for cultivation. To address this issue, scientists around the world are working on ways to reuse the water to grow microalgae so that it can be grown in successive cycles without the need for fresh water. RESULTS: In this study, we present the results when we cultivate microalgae with cultivation water that is purified and reused. Specifically, we purify the cultivation water using an ultrafiltration membrane (UFM) treatment and investigate how this treatment affects: the biomass and biochemical components of the microalgae; characteristics of microalgae growth inhibitors; the mechanism whereby potential growth inhibitors are secreted (followed using metabolomics analysis); the effect of activated carbon (AC) treatment and advanced oxidation processes (AOPs) on the removal of growth inhibitors of Euglena gracilis. Firstly, the results show that E. gracilis can be only cultivated through two growth cycles with water that has been filtered and reused, and the growth of E. gracilis is significantly inhibited when the water is used a third time. Secondly, as the number of reused water cycles increases, the Cl- concentration gradually increases in the cultivation water. When the Cl- concentration accumulates to a level of fivefold higher than that of the control, growth of E. gracilis is inhibited as the osmolality tolerance range is exceeded. Interestingly, the osmolality of the reused water can be reduced by replacing NH4Cl with urea as the source of nitrogen in the cultivation water. Thirdly, E. gracilis secretes humic acid (HA)-which is produced by the metabolic pathways for valine, leucine, and isoleucine biosynthesis and by linoleic acid metabolism-into the cultivation water. Because HA contains large fluorescent functional groups, specifically extended π(pi)-systems containing C=C and C=O groups and aromatic rings, we were able to observe a positive correlation between HA concentration and the rate of inhibition of E. gracilis growth using fluorescence spectroscopy. Moreover, photosynthetic efficiency is adversely interfered by HA, thereby reductions in the synthetic efficiency of paramylon and lipid in E. gracilis. In this way, we are able to confirm that HA is the main growth inhibitor of E. gracilis. Finally, we verify that all the HA is removed or converted into nutrients efficiently by AC or UV/H2O2/O3 treatments, respectively. As a result of these treatments, growth of E. gracilis is restored (AC treatment) and the amount of biomass is promoted (UV/H2O2/O3 treatment). CONCLUSIONS: These studies have important practical and theoretical significance for the cyclic cultivation of E. gracilis and for saving water resources. Our work may also provide a useful reference for other microalgae cultivation.

Trophic Transition Enhanced Biomass and Lipid Production of the Unicellular Green Alga Scenedesmus acuminatus.

Microalgal heterotrophic cultivation is an emerging technology that can enable producing high cell-density algal cell cultures, which can be coupled with photoautotrophic cultivation for valuable chemicals such as lipids manufacturing. However, how the heterotrophically grown algal cells respond to the lipid-inducing conditions has not been fully elucidated so far. In this study, when the heterotrophically grown Scenedesmus acuminatus cells were subjected to the high light (HL) and nitrogen-limited (NL) conditions, both the biomass and lipid productivity were enhanced as compared to that of the photoautotrophically grown counterparts. The chlorophyll a fluorometry analysis showed that the Fv/Fm and Y(II) of the heterotrophically grown cells subjected to the HL and NL conditions was recovered to the maximum value of 0.75 and 0.43, respectively, much higher than those of the photoautotrophically grown cells under the same stress conditions. Transcriptomic analysis revealed that heterotrophically grown cells fully expressed the genes coding for the photosystems proteins, including the key photoprotective proteins D1, PsbS, light-harvesting-complex (LHC) I and LHC II. Meanwhile, downregulation of the carotenoid biosynthesis and upregulation of the glycolysis/gluconeogenesis, tricarboxylic acid (TCA) cycle and oxidative phosphorylation pathways were observed when the heterotrophically grown cells were subjected to the HL and N-limited conditions for lipid production. It was deduced that regulation of these pathways not only enhanced the light utilization but also provided the reducing power and ATP by which the biomass accumulation was significantly elevated. Besides, upregulation of the acetyl-CoA carboxylase/biotin carboxylase, digalactosyl diacylglycerol synthase and diacylglycerol acyltransferase 2 encoding genes may be attributable to the enhanced lipid production. Understanding the cellular responses during the trophic transition process could guide improvement of the strength of trophic transition enhancing microalgal biomass and lipid production.

Pre-concentration of microalga Euglena gracilis by alkalescent pH treatment and flocculation mechanism of Ca3(PO4)2, Mg3(PO4)2, and derivatives.

BACKGROUND: Microalgae are widely be used in carbon sequestration, food supplements, natural pigments, polyunsaturated fatty acids, biofuel applications, and wastewater treatment. However, the difficulties incurred in algae cell separation and harvesting, and the exorbitant cost required to overcome these challenges, are the primary limitations to large-scale industrial application of microalgae technology. RESULTS: Herein, we explore the potential of inducing flocculation by adjusting the pH for pre-concentrating Euglena gracilis. Our results demonstrate that flocculation can be induced by increasing the medium pH to 8.5; however, most of the algae cells were broken by increasing the pH > 10. Magnesium phosphate, calcium phosphate, and their derivatives precipitation jointly led to flocculation, although calcium phosphate and its derivatives precipitation had a greater effect. CONCLUSIONS: This study demonstrates that pH treatment-induced flocculation is efficient and feasible for the pre-concentration of E. gracilis under a pilot-scale culture system. Moreover, it also maintained the microalgae cells' integrity, chlorophyll production, and increased paramylon production. These findings provide a theoretical basis for reducing the cost of large-scale E. gracilis harvesting; as well as provide a reference for harvesting other microalgae.

Immune activation of murine RAW264.7 macrophages by sonicated and alkalized paramylon from Euglena gracilis.

BACKGROUND: Euglena is a new super health food resource that is rich in the natural polysaccharide paramylon, a linear ß-1,3-glucan with various biological activities including activity on the immune system in different cell lines and animals. Despite these reports, the immune regulation mechanism of paramylon is still unclear. RESULTS: We investigate the signaling pathways paramylon impacts in immune macrophages. In RAW264.7 macrophages, sonicated and alkalized paramylon oligomers up-regulated inducible nitric oxide synthase (iNOS) and increased secretion of nitric oxide (NO), interleukin (IL)-6 and tumor necrosis factor (TNF)-α, in a concentration-dependent manner. In addition, paramylon activated the nuclear factor-κB(NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways and inhibiting these pathways attenuated the paramylon-induced secretion of the above immune-mediators. CONCLUSIONS: These results demonstrate that Euglena gracilis paramylon modulates the immune system via activation of the NF-κB and MAPK signaling pathways and thus has potential therapeutic benefits.

Surgical treatment of 42 patients with cerebral schistosomiasis caused by Schistosoma japonicum.

OBJECTIVE: To investigate the clinical value of surgical treatment for cerebral schistosomiasis. METHODS: The clinical data of 42 patients with cerebral schistosomiasis caused by Schistosoma japonicum undergoing surgical therapy were analyzed retrospectively. RESULTS: There were 25 cases undergoing total resection of schistosomal granulomas and 17 cases undergoing partial resection of the lesions involving the functional areas or more than 2 lobes, and none died of the surgery. The post-surgical follow-up showed that 31 cases recovered completely and returned to the normal work and life, 2 developed mild weaknesses of all extremities, 3 had post-surgical epileptic seizures, 2 died of schistosomal hepatic cirrhosis, and 1 died naturally. CONCLUSION: Surgical treatment is an effective approach for cerebral schistosomiasis.

[Preliminary study on establishing an animal model of neuroschistosomiasis by direct injection of Schistosoma japonicum eggs through skull].

OBJECTIVE: To establish an experimental model of neuroschistosomiasis and investigate the model establishment factors. METHODS: Rabbits were used for the animal model and Schistosoma japonicum eggs (1 mg/ml) were directly injected into the brain by two ways of a bone drill or needle. The symptoms were observed and in the first and second week and later, the rabbits' brains were removed for pathological examinations. RESULTS: One to two weeks after the injection of schistosome eggs, the rabbits had various neurological symptoms such as loss of appetite, hemiparesis, seizure, etc. The pathological analysis showed the schistosome egg granuloma inflammatory reaction among 90% rabbits. CONCLUSION: This new method of direct injection of S. japonicum eggs through skull into the brain provides a good and easy animal model of neuroschistosomiasis.

Microsurgery Resection of Intrinsic Insular Tumors via Transsylvian Surgical Approach in 12 Cases.

OBJECTIVE: To investigate the clinical characteristics, operative methods, and diffusion tensor imaging (DTI) in the resection of intrinsic insular gliomas via transsylvian approach. METHODS: From June 2008 to June 2010, 12 patients with intrinsic insular gliomas were treated via transsylvian microsurgical approach, with preoperative magnetic resonance imaging diffusion tensor imaging (MR DTI) evaluation. The data of these patients were retrospectively analyzed. RESULTS: All patients had astrocytoma, including 8 patients of Grades I to II, 2 patients of Grades III to IV, and 2 patients of mixed glial tumors. The insular tumors were completely removed in 9 patients, whereas they were only partially removed from 3 patients. No death was related to the operations. Two patients had transient aphasia, 2 experienced worsened hemiplegia on opposite sides of their bodies, and 2 had mild hemiplegia and language function disturbance. CONCLUSIONS: Most of the insular gliomas are of low grade. By evaluating the damage of the corticospinal tract through DTI and using ultrasonography to locate the tumors during operation, microsurgery treatment removes the lesions as much as possible, protects the surrounding areas, reduces the mobility rate, and improves the postoperative quality of life.

Clinical and imaging characteristics of cerebral schistosomiasis.

In recent years, there has been a trend for increased incidence of cerebral schistosomiasis. It is often misdiagnosed because of the diversity of clinical symptoms. We wished to explore clinical characteristics and imaging findings in cerebral schistosomiasis. We retrospectively analyzed clinical data, laboratory tests, CT, and MRI results in 11 patients with cerebral schistosomiasis. All patients had chronic cerebral schistosomiasis (five with epilepsy type, five with brain tumor type, and one patient with stroke type). All patients with brain tumor type were misdiagnosed as having gliomas. There were typical findings on CT and MRI. In conclusion, clinical manifestations of cerebral schistosomiasis are variable, and the rate of misdiagnosis is high. For more precise diagnosis, a combination of laboratory and imaging data is required.

Establishment of a cerebral schistosomiasis experimental model in rabbits.

OBJECTIVE: The present study aimed to establish a cerebral schistosomiasis model in rabbits, to provide a valuable tool for morphological analysis, clinical manifestation observation, as well as investigations into immunological reactions and pathogenesis of focal inflammatory reaction in neuroschistosomiasis (NS). METHODS: Sixty New Zealand rabbits were randomly assigned into operation, sham-operation and normal groups. Rabbits in the operation group received direct injection of dead schistosome eggs into the brain, while their counterparts in the sham-operation group received saline injection. Rabbits in the normal group received no treatment. Base on the clinical manifestations, rabbits were sacrificed on days 3, 5, 7, 10, 20, and 30 post injection, and brain samples were sectioned and stained with hematoxylin-eosin. Sections were observed under the microscope. RESULTS: The rabbits in the operation group exhibited various neurological symptoms, including anorexy, partial and general seizures, and paralysis. The morphological analysis showed several schistosome eggs in the nervous tissue on day 3 post operation, with very mild inflammation. On days 7-10 post operation, several schistosome eggs were localized in proximity to red blood cells with many neutrophilic granulocytes and eosinophilic granulocytes around them. The schistosome eggs developed into the productive granuloma stage on days 14-20 post operation. On day 30, the schistosome eggs were found to be in the healing-by-fibrosis stage, and the granuloma area was replaced by fibrillary glia through astrocytosis. The sham-operation group and the normal group showed negative results. CONCLUSION: This method might be used to establish the cerebral schistosomiasis experimental model. Several factors need to be considered in establishing this model, such as the antigenic property of eggs, the time of scarification, and the clinical manifestations.

Research development of the pathogenesis pathways for neuroschistosomiasis.

The infection of the central nervous system (CNS) by schistosome may or may not have clinical manifestations. When symptomatic, neuroschistosomiasis (NS) is one of the most severe presentations of schistosome infection. Among the NS symptoms, cerebral invasion is mostly caused by Schistosoma japonicum (S. japonicum), and the spinal cord symptoms are mainly caused by S. mansoni or S. haematobium. There are 2 main pathways by which schistosomes cause NS: egg embolism and worm migration, via either artery or vein system, especially the valveless perivertebral Batson's plexus. The adult worm migrates anomalously through the above pathways to the CNS where they lay eggs. Due to the differences in species of schistosomes and stages of infection, mechanisms vary greatly. The portal hypertension with hepatosplenic schistosomiasis also plays an important role in the pathogenesis. Here the pathways through which NS occurs in the CNS were reviewed.

[Surgical treatment of patients with cerebral schistosomiasis].

Clinical data from 48 cases with cerebral schistosomiasis, who received surgery, were analyzed retrospectively. Surgical treatment was performed when the patient had the following conditions: mass focus confirmed by CT scanning, cranial hypertension, or ineffective drug therapy, or indistinguishable from glioma by iconographic diagnosis. Treatment of praziquantel was given when the patients got improved. Among the 48 patients with surgical treatment, 35 cases recovered, 8 showed an exacerbation of hemiparalysis, 5 had hemianesthesia, and epilepsy occurred in 2 cases, no cases died during or after the operation. Surgery combined with praziquantel therapy has been an effective way for the treatment of cerebral schistosomiasis.

Rapid natural resolution of intracranial hematoma.

OBJECTIVE: To investigate the clinical characteristics of intracranial hematoma and the mechanism involved in its rapid natural resolution. METHODS: Seventeen cases of intracranial hematoma with typical clinical and CT manifestations were retrospectively studied. RESULTS: Intracranial hematoma was found obviously decreased in size within 72 h after its occurrence in 8 cases. The rest 9 cases presented complete resolution. CONCLUSIONS: Rapid natural resolution of acute epidural hematoma is mostly found in teenagers and the resolution is correlated with cranial fracture at the hematoma site. As for acute subdural hematoma, its rapid resolution is associated with the transfer of cerebrospinal fluid toward subdural space, the lavage effect, and the compression caused by the increased intracranial pressure or the space left resulting from redistribution of the hematoma in brain atrophy.