Lipid production by microalgae <Emphasis Type="Italic">Chlorella protothecoides</Emphasis> with volatile fatty acids (VFAs) as carbon sources in heterotrophic cultivation and its economic assessment

Volatile fatty acids (VFAs) that can be derived from food wastes were used for microbial lipid production by Chlorella protothecoides in heterotrophic cultures. The usage of VFAs as carbon sources for lipid accumulation was investigated in batch cultures. Culture medium, culture temperature, and nitrogen sources were explored for lipid production in the heterotrophic cultivation. The concentration and the ratio of VFAs exhibited significant influence on cell growth and lipid accumulation. The highest lipid yield coefficient and lipid content of C. protothecoides grown on VFAs were 0.187 g/g and 48.7 %, respectively. The lipid content and fatty acids produced using VFAs as carbon sources were similar to those seen on growth and production using glucose. The techno-economic analysis indicates that the biodiesel derived from the lipids produced by heterotrophic C. protothecoides with VFAs as carbon sources is very promising and competitive with other biofuels and fossil fuels.     

Tea Consumption and Cognitive Impairment: A Cross-Sectional Study among Chinese Elderly

Background

Laboratorial and epidemiological researches suggested that tea exhibited potential neuroprotective effect which may prevent cognitive impairment, but there were few data among the elderly aged 60 years and above in China.

Objective

The objective was to explore the relationship between characteristics of tea consumption and cognitive impairment.

Design

We analyzed the baseline data from Zhejiang Major Public Health Surveillance Program (ZPHS) which was conducted in 2014. Totally 9,375 residents aged 60 years and above were recruited in this study. Face-to-face interview based on a self-developed questionnaire was performed for each participant. Detailed tea consumption habits were included in the questionnaire. Cognitive impairment screening was performed by using Mini-Mental State Examination (MMSE). Education-specific cut-off points for Chinese were applied to determine the status of cognitive impairment. Logistic regression analysis was used to calculate odds ratios (ORs) of cognitive impairment associated with tea consumption.

Results

The means (SD) of MMSE scores for the subjects who did not consume tea and consumed <2 cups/d, 2–4 cups/d, ≥4 cups/d were 23.3 (SD = 5.61), 23.8 (SD = 5.60), 24.5 (SD = 5.63) and 25.0 (SD = 5.08), respectively. An inverse correlation was found between tea consumption (of all types) and prevalence of cognitive impairment. Volume of tea consumption was significantly associated with cognitive impairment: compared with non-consumption participants, those who consumed < 2 cups/d, 2–4 cups/d, and ≥4 cups/d were observed ORs of 0.77 (95% CI: 0.56, 1.07), 0.62 (95% CI: 0.47, 0.81), and 0.49 (95% CI: 0.36, 0.66), respectively. Compared with non-consumption, black tea presented a positive correlation with cognitive function after controlling for potential confounders (OR = 0.52, 95% CI: 0.28, 0.95), while green tea showed no significant difference (OR = 1.04, 95% CI: 0.72, 1.51). Participants who consumed weak tea, moderate tea or strong tea more often were observed a better cognitive status when compared with those who did not have tea, with an OR of 0.51 (95% CI: 0.28, 0.92), 0.32 (95% CI: 0.19, 0.56) and 0.42 (95% CI: 0.22, 0.78) after adjusting for the potential confounders. But there was no statistically significant difference between any two of these ORs.

Conclusion

Black tea consumption was association with better cognitive performance among the elderly aged 60 years and above in China, while green tea presented no correlation. The positive association of cognitive status with tea consumption was not limited to particular type of concentration.     

Finite Element Analysis of a New Pedicle Screw-Plate System for Minimally Invasive Transforaminal Lumbar Interbody Fusion

Purpose

Minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) is increasingly popular for the surgical treatment of degenerative lumbar disc diseases. The constructs intended for segmental stability are varied in MI-TLIF. We adopted finite element (FE) analysis to compare the stability after different construct fixations using interbody cage with posterior pedicle screw-rod or pedicle screw-plate instrumentation system.

Methods

A L3–S1 FE model was modified to simulate decompression and fusion at L4–L5 segment. Fixation modes included unilateral plate (UP), unilateral rod (UR), bilateral plate (BP), bilateral rod (BR) and UP+UR fixation. The inferior surface of the S1 vertebra remained immobilized throughout the load simulation, and a bending moment of 7.5 Nm with 400N pre-load was applied on the L3 vertebra to recreate flexion, extension, lateral bending, and axial rotation. Range of motion (ROM) and Von Mises stress were evaluated for intact and instrumentation models in all loading planes.

Results

All reconstructive conditions displayed decreased motion at L4–L5. The pedicle screw-plate system offered equal ROM to pedicle screw-rod system in unilateral or bilateral fixation modes respectively. Pedicle screw stresses for plate system were 2.2 times greater than those for rod system in left lateral bending under unilateral fixation. Stresses for plate were 3.1 times greater than those for rod in right axial rotation under bilateral fixation. Stresses on intervertebral graft for plate system were similar to rod system in unilateral and bilateral fixation modes respectively. Increased ROM and posterior instrumentation stresses were observed in all loading modes with unilateral fixation compared with bilateral fixation in both systems.

Conclusions

Transforaminal lumbar interbody fusion augmentation with pedicle screw-plate system fixation increases fusion construct stability equally to the pedicle screw-rod system. Increased posterior instrumentation stresses are observed in all loading modes with plate fixation, and bilateral fixation could reduce stress concentration.     

Complete Blood Count Reference Intervals for Healthy Han Chinese Adults

Background

Complete blood count (CBC) reference intervals are important to diagnose diseases, screen blood donors, and assess overall health. However, current reference intervals established by older instruments and technologies and those from American and European populations are not suitable for Chinese samples due to ethnic, dietary, and lifestyle differences. The aim of this multicenter collaborative study was to establish CBC reference intervals for healthy Han Chinese adults.

Methods

A total of 4,642 healthy individuals (2,136 males and 2,506 females) were recruited from six clinical centers in China (Shenyang, Beijing, Shanghai, Guangzhou, Chengdu, and Xi’an). Blood samples collected in K2EDTA anticoagulant tubes were analyzed. Analysis of variance was performed to determine differences in consensus intervals according to the use of data from the combined sample and selected samples.

Results

Median and mean platelet counts from the Chengdu center were significantly lower than those from other centers. Red blood cell count (RBC), hemoglobin (HGB), and hematocrit (HCT) values were higher in males than in females at all ages. Other CBC parameters showed no significant instrument-, region-, age-, or sex-dependent difference. Thalassemia carriers were found to affect the lower or upper limit of different RBC profiles.

Conclusion

We were able to establish consensus intervals for CBC parameters in healthy Han Chinese adults. RBC, HGB, and HCT intervals were established for each sex. The reference interval for platelets for the Chengdu center should be established independently.     

24h Urinary Protein Levels and Urine Protein/Creatinine Ratios Could Probably Forecast the Pathological Classification of HSPN

This study aimed to assess the relevance of laboratory tests in Henoch-Schönlein purpura nephritis (HSPN) classification, and determine accurate classification factors. This prospective study included 694 HSPN patients who underwent ultrasound-guided percutaneous renal biopsy (PRB). Renal specimens were scored according to International Study of Kidney Disease in Children (ISKDC) classification. Meanwhile, blood samples were immediately collected for laboratory examination. The associations between laboratory parameters and HSPN classification were assessed. Significant differences in levels of serum Th1/Th2 cytokines, immunoglobulins, T-lymphocyte subsets, complement, and coagulation markers were obtained between HSPN patients and healthy children. Interestingly, 24h urinary protein (24h-UPRO) levels and urine protein/urine creatinine ratios could determine HPSN grade IIb, IIIa, and IIIb incidences, with areas under ROC curve of 0.767 and 0.731, respectively. At 24h-UPRO >580.35mg/L, prediction sensitivity and specificity were 75.2% and 70.0%, respectively. These values became 53.0% and 82.3%, respectively, with 24h-UPRO exceeding 1006.25mg/L. At urine protein/urine creatinine > 0.97, prediction sensitivity and specificity were 65.5% and 67.2%, respectively, values that became 57.4% and 80.0%, respectively, at ratios exceeding 1.2. Cell and humoral immunity, coagulation and fibrinolytic systems are all involved in the pathogenesis of HSPN, and type I hypersensitivity may be the disease trigger of HSPN. 24h-UPRO levels and urine protein/creatinine ratios could probably forecast the pathological classification of HSPN.     

Collagen-Like Proteins (ClpA,ClpB, ClpC,and ClpD) Are Required for Biofilm Formation and Adhesion to Plant Roots by Bacillus amyloliquefaciens FZB42

The genes of collagen-like proteins (CLPs) have been identified in a broad range of bacteria, including some human pathogens. They are important for biofilm formation and bacterial adhesion to host cells in some human pathogenic bacteria, including several Bacillus spp. strains. Interestingly, some bacterial CLP-encoding genes (clps) have also been found in non-human pathogenic strains such as B. cereus and B. amyloliquefaciens, which are types of plant-growth promoting rhizobacteria (PGPR). In this study, we investigated a putative cluster of clps in B. amyloliquefaciens strain FZB42 and a collagen-related structural motif containing glycine-X-threonine repeats was found in the genes RBAM_007740, RBAM_007750, RBAM_007760, and RBAM_007770. Interestingly, biofilm formation was disrupted when these genes were inactivated separately. Scanning electron microscopy and hydrophobicity value detection were used to assess the bacterial cell shape morphology and cell surface architecture of clps mutant cells. The results showed that the CLPs appeared to have roles in bacterial autoaggregation, as well as adherence to the surface of abiotic materials and the roots of Arabidopsis thaliana. Thus, we suggest that the CLPs located in the outer layer of the bacterial cell (including the cell wall, outer membrane, flagella, or other associated structures) play important roles in biofilm formation and bacteria-plant interactions. This is the first study to analyze the function of a collagen-like motif-containing protein in a PGPR bacterium. Knocking out each clp gene produced distinctive morphological phenotypes, which demonstrated that each product may play specific roles in biofilm formation. Our in silico analysis suggested that these four tandemly ranked genes might not belong to an operon, but further studies are required at the molecular level to test this hypothesis. These results provide insights into the functions of clps during interactions between bacteria and plants.     

Sec22 Regulates Endoplasmic Reticulum Morphology but Not Autophagy and Is Required for Eye Development in Drosophila

The endoplasmic reticulum (ER) is a highly dynamic organelle that plays a critical role in many cellular processes. Abnormal ER morphology is associated with some human diseases, although little is known regarding how ER morphology is regulated. Using a forward genetic screen to identify genes that regulated ER morphology in Drosophila, we identified a mutant of Sec22, the orthologs of which in yeast, plants, and humans are required for ER to Golgi trafficking. However, the physiological function of Sec22 has not been previously investigated in animal development. A loss of Sec22 resulted in ER proliferation and expansion, enlargement of late endosomes, and abnormal Golgi morphology in mutant larvae fat body cells. However, starvation-induced autophagy was not affected by a loss of Sec22. Mosaic analysis of the eye revealed that Sec22 was required for photoreceptor morphogenesis. In Sec22 mutant photoreceptor cells, the ER was highly expanded and gradually lost normal morphology with aging. The rhabdomeres in mutants were small and sometimes fused with each other. The morphology of Sec22 mutant eyes resembled the eye morphology of flies with overexpressed eyc (eyes closed). eyc encodes for a Drosophila p47 protein that is required for membrane fusion. A loss of Syntaxin5 (Syx5), encoding for a t-SNARE on Golgi, also phenocopied the Sec22 mutant. Sec22 formed complexes with Syx5 and Eyc. Thus, we propose that appropriate trafficking between the ER and Golgi is required for maintaining ER morphology and for Drosophila eye morphogenesis.     

The Orphan Nuclear Receptor NR4A1 Protects Pancreatic β-Cells from Endoplasmic Reticulum (ER) Stress-mediated Apoptosis

The role of NR4A1 in apoptosis is controversial. Pancreatic β-cells often face endoplasmic reticulum (ER) stress under adverse conditions such as high free fatty acid (FFA) concentrations and sustained hyperglycemia. Severe ER stress results in β-cell apoptosis. The aim of this study was to analyze the role of NR4A1 in ER stress-mediated β-cell apoptosis and to characterize the related mechanisms. We confirmed that upon treatment with the ER stress inducers thapsigargin (TG) or palmitic acid (PA), the mRNA and protein levels of NR4A1 rapidly increased in both MIN6 cells and mouse islets. NR4A1 overexpression in MIN6 cells conferred resistance to cell loss induced by TG or PA, as assessed by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, and TUNEL assays indicated that NR4A1 overexpression also protected against ER stress-induced apoptosis. This conclusion was further confirmed by experiments exploiting siRNA to knockdown NR4A1 expression in MIN6 cells or exploiting NR4A1 knock-out mice. NR4A1 overexpression in MIN6 cells reduced C/EBP homologous protein (CHOP) expression and Caspase3 activation induced by TG or PA. NR4A1 overexpression in MIN6 cells or mouse islets resulted in Survivin up-regulation. A critical regulatory element was identified in Survivin promoter (−1872 bp to −1866 bp) with a putative NR4A1 binding site; ChIP assays demonstrated that NR4A1 physically associates with the Survivin promoter. In conclusion, NR4A1 protects pancreatic β-cells against ER stress-mediated apoptosis by up-regulating Survivin expression and down-regulating CHOP expression, which we termed as “positive and negative regulation.”