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Objective: To study the hypoglycemic effect and mechanism of guar gum manno-oligosaccharides (GMOS) on streptozotocin-induced diabetic mice. Methods: GMOS was administered to diabetic mice for 6 weeks, and the changes in body mass and insulin resistance were monitored. Furthermore, indicators of glucose and lipid metabolism such as glucose (GLU), insulin (INS), high density lipoprotein cholesterol (HDL-C), and low density lipoprotein cholesterol (LDL-C) were determined. Hepatic histopathological changes were observed, and the expression of proteins involved in the adenosine monophosphate-activated protein kinase (AMPK)/peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) signaling pathway and the activity of antioxidant enzymes in the liver were detected. Results: GMOS effectively relieved the body mass loss of diabetic mice, significantly alleviated glucose tolerance (30.3%) and enhanced insulin sensitivity (34.6%). Compared with the model group, GMOS decreased the levels of GLU, glycosylated serum protein (GSP) and LDL-C by 38.6%, 29.5%, and 27.3%, respectively, and increased the levels of insulin and HDL-C significantly. Moreover, GMOS reduced oxidative damage, activated the AMPK/PGC-1α signaling pathway, and improved the activities of superoxide dismutase (SOD) and catalase (CAT) in the liver. Conclusion: GMOS could reduce blood glucose and mitigate glucose and lipid metabolism disorder and oxidative stress caused by diabetes mellitus, indicating its potential as a functional food ingredient against diabetes.

Objective: To analyze the clinical features and genetic changes of 3 children in short stature with ACAN gene mutation. Methods: The clinical data, laboratory examinations, and genetic testing results of 3 children with ACAN gene mutations diagnosed with short stature at our pediatric endocrine disease clinic from 2018 to 2020 were collected, and the literature was reviewed for analysis and summary. Results: All the three children had a short family history, and their clinical manifestations were short stature. One patient had a slight limitation of the flexion activity of the thoracolumbar spine, and no other system abnormalities were found. Among them, the oldest of the 3 children was 5 years and 1 month, and the bone age was roughly consistent with or slightly advanced than the actual age, and the peak growth hormone challenge in 2 cases was less than 10 μg/L. The variations in the ACAN gene are c.G1877A and c.7360, respectively_ 7361del and c.7038_ 7039insCGGTGT, case 1 and case 2 are novel mutations that have not been reported in major databases. After the application of recombinant human growth hormone, the height of all three children improved. Reviewing the literature at home and abroad, we found that there were 120 children and 216 relatives reported at present. Among them, there were 80 ACAN gene variants related to short stature registered in HGMD, of which short stature was the most important clinical manifestation, followed by skeletal dysplasia. Conclusions: Mutations of ACAN gene mainly lead to short stature and skeletal dysplasia in children, and their clinical bone phenotypes are diverse, which can also only be manifested as short stature. For children with short stature, especially those with short stature family history, no matter whether they have skeletal abnormalities, they should be alert to this gene mutation.

In this study, beef was marinated with different low-sodium salt substitutes and heated and aged by employing superheated steam roasting and traditional roasting to investigate the effects of the various substitutes on the physicochemical properties, texture profile, sensory properties, volatile compounds, microstructural characteristics, and safety of cured and aged beef. Twenty kilograms of beef were arbitrarily divided into five treatments and pickled with different low-sodium salt substitutes. The results revealed no significant differences in saltiness, physicochemical characteristics, texture profile, or volatile compounds between the T2 and T3 and T1 (100% NaCl, T1; 75% KCl + 25% NaCl, T2; 50% KCl + 50% NaCl, T3) samples. Furthermore, the T4 and T5 (50% NaCl + 25% KCl + 20% MgCl2 + 5% CaCl2, T4; 100% yeast extract, T5) samples had lower saltiness than the T1 sample. The plasmolysis percentage and osmotic pressure of the T2 and T3 samples were lower than those of the T1 sample. Therefore, reducing sodium by substituting NaCl with 50% KCl or 75% KCl maintained an acceptable sensory and safety profile for beef consumption.

Objective: To explore the genotype and clinical phenotype of congenital generalized lipodystrophy type 1(CGL1), and to improve awareness of the disease. Methods: A patient with severe acanthosis nigricans was diagnosed as having CGL1, and the clinical information and results of laboratory and gene tests were analyzed. Five Chinese cases with CGL1 in the database were literaturally reviewed. Results: The patient was a girl(10 years and 11 months), who had significantly acanthosis nigricans and body subcutaneous fat loss. The examination of the girl showed hyperinsulinemia, impaired glucose tolerance, advanced bone age, low adiponectin and polycystic ovary. The compound heterozygous mutations were identified, which was c.646A>T:p.K216*(PVS1_Strong+ PM2+PM3 ( inherited from her father) and c.406G>A:p.G136R(PM3_Strong+PM1+PM2+PP3 (inherited from her mother) in AGPAT2 gene. The mutation of two gene loci could be pathogenic, which had not been reported in CNKI database. All 5 Chinese cases in CNKI database were reported before (including 2 males and 3 females, and age was between 66 days and 26 years old) showed the absence of adipose tissue, in which two patients presented severe acanthosis nigricans. Conclusions: The CGL1 is rare in Chinese population, and it should be considered as the patients present the acanthosis nigricans and absence of adipose tissue, and its diagnosis depends gene detection.

Laminaripentaose (L5)‐producing β‐1,3‐glucanases can preferentially cleave the triple‐helix curdlan into β‐1,3‐glucooligosaccharides, especially L5. In this study, a newly identified member of the glycoside hydrolase family 64, β‐1,3‐glucanase from Streptomyces pratensis (SpGlu64A), was functionally and structurally characterized. SpGlu64A shared highest identity (30%) with a β‐1,3‐glucanase from Streptomyces matensis. The purified SpGlu64A showed maximal activity at pH 7.5 and 50 °C, and exhibited strict substrate specificity toward curdlan (83.1 U·mg−1). It efficiently hydrolyzed curdlan to produce L5 as the end product. The overall structure of SpGlu64A consisted of a barrel domain and a mixed (α/β) domain, which formed an unusually wide groove with a crescent‐like structure. In the two complex structures (SpGlu64A–L3 and SpGlu64A–L4), two oligosaccharide chains were captured and the triple‐helical structure was relatively compatible with the wide groove, which suggested the possibility of binding to the triple‐helical β‐1,3‐glucan. A catalytic framework (β6–β9–β10) and the steric hindrance formed by the side chains of residues Y161, N163, and H393 in the catalytic groove were predicted to complete the exotype‐like cleavage manner. On the basis of the structure, a fusion protein with the CBM56 domain (SpGlu64A–CBM) and a mutant (Y161F; by site‐directed mutation) were obtained, with 1.2‐ and 1.7‐fold increases in specific activity, respectively. Moreover, the combined expression of SpGlu64A–CBM and ‐Y161F improved the enzyme activity by 2.63‐fold. The study will not only be helpful in understanding the reaction mechanism of β‐1,3‐glucanases but will also provide a basis for further enzyme engineering. [ABSTRACT FROM AUTHOR]

In heterogeneous catalysis, uncovering the dynamic evolution of active sites in the working conditions is crucial to realizing increased activity and enhanced stability of catalyst in Fenton-like activation. Herein, we capture the dynamic changes in the unit cell of Co/La-SrTiO3 catalyst during the exemplary peroxymonosulfate activation process using X-ray absorption spectroscopy and in situ Raman spectroscopy, revealing the substrate tuned its structural evolution, which is the reversible stretching vibration of O-Sr-O and Co/Ti-O bonds in different orientations. This process effectively promotes the generation of key SO5* intermediates, which is beneficial to the formation of 1O2 and SO4•− from persulfate on the Co active site. Density functional theory and X-ray absorption spectroscopy show that the optimized structural distortion enhanced the metal-oxygen bond strength by tuning the eg orbitals and increased the number of transferred electrons to peroxymonosulfate by about 3-fold, achieving excellent efficiency and stability in removing organic pollutants. Uncovering the dynamic evolution of active sites in the working conditions is crucial to realizing increased activity and enhanced stability of catalyst in Fenton-like activation. Herein, the authors capture the dynamic changes in the unit cell of Co/La-SrTiO3 catalyst during the exemplary peroxymonosulfate activation process. [ABSTRACT FROM AUTHOR]

This study sought to identify a reference tissue‐based quantification approach for improving the statistical power in detecting changes in brain glucose metabolism, amyloid, and tau deposition in Alzheimer's disease studies. A total of 794, 906, and 903 scans were included for 18F‐FDG, 18F‐florbetapir, and 18F‐flortaucipir, respectively. Positron emission tomography (PET) and T1‐weighted images of participants were collected from the Alzheimer's disease Neuroimaging Initiative database, followed by partial volume correction. The standardized uptake value ratios (SUVRs) calculated from the cerebellum gray matter, centrum semiovale, and pons were evaluated at both region of interest (ROI) and voxelwise levels. The statistical power of reference tissues in detecting longitudinal SUVR changes was assessed via paired t‐test. In cross‐sectional analysis, the impact of reference tissue‐based SUVR differences between cognitively normal and cognitively impaired groups was evaluated by effect sizes Cohen's d and two sample t‐test adjusted by age, sex, and education levels. The average ROI t values of pons were 86.62 and 38.40% higher than that of centrum semiovale and cerebellum gray matter in detecting glucose metabolism decreases, while the centrum semiovale reference tissue‐based SUVR provided higher t values for the detection of amyloid and tau deposition increases. The three reference tissues generated comparable d images for 18F‐FDG, 18F‐florbetapir, and 18F‐flortaucipir and comparable t maps for 18F‐florbetapir and 18F‐flortaucipir, but pons‐based t map showed superior performance in 18F‐FDG. In conclusion, the tracer‐specific reference tissue improved the detection of 18F‐FDG, 18F‐florbetapir, and 18F‐flortaucipir PET SUVR changes, which helps the early diagnosis, monitoring of disease progression, and therapeutic response in Alzheimer's disease. [ABSTRACT FROM AUTHOR]