Os4BGlu14, a monolignol ß-Glucosidase, negatively affects seed longevity by influencing primary metabolism in rice.

KEY MESSAGE: Os4BGlu14, a monolignol ß-glucosidase, plays a negative role in seed longevity by affecting primary metabolism during seed development and aging. Seed longevity is a crucial trait in agriculture and in the conservation of germplasm resources. ß-Glucosidases (BGlus) are multifunctional enzymes that affect plant growth and their adaptation to the environment. The function of rice BGlus in seed longevity, however, remains unknown. We report here that Os4BGlu14, a rice ß-Glucosidase, negatively affected seed longevity during accelerated aging. Os4BGlu14 was highly expressed in rice embryos and induced by accelerated aging. Compared to the wild type, rice lines overexpressing Os4BGlu14 had significantly greater grain length, but smaller grain width and thickness. Overexpressing (OE) lines also showed lower starch but higher glucose contents. After accelerated aging treatment, OE lines displayed a significantly lower germination percentage than the wild type. Additionally, these lines had higher lignin accumulation before and after accelerated aging. Metabolome analysis detected 217 metabolites in untreated and aged rice seeds. Comparison of the differential metabolites between WT and OE5 revealed that ten key metabolites, four of which (e.g., uridine 5'-diphosphoglucose-glucose, UDPG) were increased, while the other six (e.g., γ-aminobutyric acid and methionine) were decreased, might be the crucial factors that lead to seed deterioration. Further analysis confirmed higher UDPG levels and more severe programmed cell death in OE lines than in the wild type. Furthermore, OE lines presented a lower germination rate after abscisic acid and paclobutrazol treatment during germination, compared to the wild type. Our study provides a basis for understanding the function of Os4BGlu14 in seed longevity in rice.

Differential degradation rate and underlying mechanism of a collagen/chitosan complex in subcutis, spinal cord and brain tissues of rat.

Degradation rate is an important index for evaluating biomaterials. The authors' aim was to determine whether the degradation rate of biomaterials is different in distinct tissues and to clarify the underlying mechanism of degradation. The collagen-chitosan (CG-CS) composite scaffolds were prepared using freeze-drying technology. The porosity, water absorption and swelling ratio of the scaffolds were tested in vitro. The scaffolds were implanted into the subcutis, spinal cord and brain tissues of SD rats, the rate of degradation was assessed by continuous monitoring of weight loss, the pathological changes of target areas were observed by histological staining, and matrix metalloproteinase 9 (MMP-9) and lysozyme were detected at the rapid stage of degradation of the scaffolds. Physical and chemical property testing confirmed that CG-CS composite scaffold components can meet the biological requirements of in vivo transplantation. The in vivo experimental results showed that the scaffolds were completely absorbed in the subcutis at 12 days, the scaffolds in the spinal cord and brain groups exhibited progressive mass loss starting from the 3rd week, and a substantial fraction of the scaffold was degraded at 12 weeks. HE staining found that compared with the spinal cord and brain groups, macrophages and capillaries appeared earlier in the subcutis group, and the number was significantly higher (P < 0.05). Western blot analysis showed that the MMP-9 and lysozyme levels in the subcutis were higher than those in the spinal cord and brain (P < 0.05). The results of in vivo experiments demonstrated that the CG-CS scaffold has good biocompatibility and biodegradability, while the rate of degradation was significantly different between the three tissues at the same time point. Macrophage behavior and vascularization in different parts of the body may result in control over the balance of degradation and reconstruction.

Cloning and functional analysis of Gb4CL1 and Gb4CL2 from Ginkgo biloba.

4-Coumarate-CoA ligase (4CL) gene plays vital roles in plant growth and development, especially the regulation of lignin metabolism and flavonoid synthesis. To investigate the potential function of 4CL in the lignin biosynthesis of Ginkgo biloba, this study identified two 4CL genes, Gb4CL1 and Gb4CL2, from G. biloba genome. Based on the phylogenetic tree analysis, Gb4CL1 and Gb4CL2 protein were classified into Class I, which has been confirmed to be involved in lignin biosynthesis. Therefore, it can be inferred that these two genes may also participate in lignin metabolism. The tissue-specific expression patterns of these two genes revealed that Gb4CL1 was highly expressed in microstrobilus, whereas Gb4CL2 was abundant in immature leaves. The onion transient expression assay indicated that Gb4CL1 was predominantly localized in the nucleus, indicating its potential involvement in nuclear functions, while Gb4CL2 was observed in the cell wall, suggesting its role in cell wall-related processes. Phytohormone response analysis revealed that the expression of both genes was upregulated in response to indole acetic acid, while methyl jasmonate suppressed it, gibberellin exhibited opposite effects on these genes. Furthermore, Gb4CL1 and Gb4CL2 expressed in all tissues containing lignin that showed a positive correlation with lignin content. Thus, these findings suggest that Gb4CL1 and Gb4CL2 are likely involved in lignin biosynthesis. Gb4CL1 and Gb4CL2 target proteins were successfully induced in Escherichia coli BL21 with molecular weights of 85.5 and 89.2 kDa, proving the integrity of target proteins. Our findings provided a basis for revealing that Gb4CL participated in lignin synthesis in G. biloba.

The clinical significance comparison of a latex agglutination based syphilis screening test at low antibody titer.

The rapid increase of syphilis underscores a tremendous need to carefully evaluate many new serological tests for syphilis and choose efficient and economical strategies for syphilis screening, especially in the case of primary infection with low antibody titer. Between 2011 and 2012, 73 patients' sera samples were included in this retrospective study. They were either TRUST or TPPA reactive, either LA (latex agglutination) based auto3 TP or CLIA (chemiluminescence assay) based Architect Syphilis TP assay reactive. The contradictory weak response samples were further examined by FTA-Abs method. TPPA could not give reactive results in samples with antibody concentration less than 10 mIU. Auto3 TP reagent shows good linearity at low antibody titers and was more sensitive than TPPA, while the former does not show significant superiority compared to the Architect Syphilis TP assay at low antibody titer, except that it is suitable for adaptation on diverse automated chemistry analyzers.

Clinical summary of pediatric acute lymphoblastic leukemia patients complicated with asparaginase-associated pancreatitis in SCCLG-ALL-2016 protocol.

Asparaginase-associated pancreatitis (AAP) is a common and fatal complication after ASNase treatment in acute lymphoblastic leukemia(ALL). Here, a total of 1063 pediatric ALL patients treated with SCCLG-ALL-2016 regimen were collected since October 2016 to June 2020, including 35 patients with AAP. The clinical characteristics of AAP and non-AAP patients were compared. In AAP patients, the possible factors that affected the recurrence of AAP were analyzed, and the possible risk factors related to ALL-relapse were discussed. The results showed that age was a risk factor (P = .017) that affect the occurrence of AAP. In AAP patients, AAP tended to develop after the second use of PEG-ASNase (25.71%). In the follow-up chemotherapy, 17 patients re-exposed to ASNase and 7 cases developed AAP again with a percentage was 41.2%. There were no special factors that related with the recurrence of AAP. This study also found no association between the occurrence of AAP and prognosis of ALL, with the 4-year incidence of ALL relapse in AAP and non-AAP patients were 15.9% v.s.11.7% (HR: 1.009, 95% CI:0.370-2.752, P = .986), and there were no special factors that related with the ALL relapse among AAP patients. Based on the above results, the occurrence of AAP is related to age and should be vigilant after the second use of PEG-ASNase after use in pediatric ALL patients. Moreover, AAP is not associated with ALL relapse, but there is a high AAP recurrence rate when re-exposure to ASNase.

[Preparation of a zinc porphyrinated nanofibrous membrane and its ammonia sensing property].

OBJECTIVE: To prepare a zinc porphyrinated polyimide nanofibrous membrane for rapid detection of trace amount of ammonia. METHODS: Zinc porphyrin chromophore was copolymerized into polyimide backbones and the according nanofibrous membrane was prepared by electrospinning technique. Ammonia detection was achieved by recording the color and spectral changes of the membrane before and after exposing to the target gas. The sensitivity, selectivity and detection limit of prepared membrane were further studied. RESULTS: The obtained nanofibrous membrane preserved typical photophysical properties of zinc porphyrin chromophores. When exposed to ammonia, a dual chromo and spectrum responses of the nanofibrous membrane were observed. The binding affinity constant and the detection limit of zinc porphyrinated polyimide nanofibrous membrane calculated from surface plasmon resonance (SPR) analysis and UV-vis were 3.33 X10³ L/mol and 3.13 mg/m³, respectively. CONCLUSION: The membrane prepared in this study exhibits good sensitivity, selectivity and reproducibility towards ammonia detection.

Amorphous Precursor-Mediated Calcium Phosphate Coatings with Tunable Microstructures for Customized Bone Implants.

Calcium phosphate (CaP) is frequently used as coating for bone implants to promote osseointegration. However, commercial CaP coatings via plasma spraying display similar microstructures, and thus fail to provide specific implants according to different surgical conditions or skeletal bone sites. Herein, inspired by the formation of natural biominerals with various morphologies mediated by amorphous precursors, CaP coatings with tunable microstructures mediated by an amorphous metastable phase are fabricated. The microstructures of the coatings are precisely controlled by both polyaspartic acid and Mg2+ . The cell biological behaviors, including alkaline phosphatase activity, mineralization, and osteogenesis-related genes expression, on the CaP coatings with different microstructures, exhibit significant differences. Furthermore, in vivo experiments demonstrate the osseointegration in different types of rats and bones indeed favors different CaP coatings. This biomimetic strategy can be used to fabricate customized bone implants that can meet the specific requirements of various surgery conditions.

Hot melt extrusion technology for improved dissolution, solubility and "spring-parachute" processes of amorphous self-micellizing solid dispersions containing BCS II drugs indomethacin and fenofibrate: Profiles and mechanisms.

Many strategies have been employed to improve oral drug delivery. One such approach involves the use of supersaturable delivery systems such as amorphous self-micellizing solid dispersions (SmSDs). SmSDs have attracted more attention recently, but little is known regarding the impact of production methods on profiles and internal mechanisms of final SmSDs in spite of its importance. In this study, amorphous SmSDs containing self-micellizing Soluplus® and BCS II drug (either indomethacin (IND) or fenofibrate (FEN)) were generated using various methods: solvent evaporation (SOL), freeze-drying (FD), microwave radiation-quench cooling (MQC), and hot melt extrusion (HME). Microscopic morphology, amorphous state, thermal behavior, dissolution/solubility, and "spring-parachute" data were used to assemble physicochemical profiles for SmSD systems prepared using each method. Analysis of intermolecular interactions, solubilization, and crystallization inhibition further uncovered internal mechanisms explaining observed physicochemical properties. Generally, SmSD/IND and SmSD/FEN systems generated using HME exhibited superior dissolution, solubility, and spring-parachute profiles. The superior advantages of HME-generated SmSD/IND systems were attributed to relatively stronger intermolecular interactions than observed in SmSD/IND systems fabricated using other methods. Moreover, self-micellizing Soluplus® carrier was able to solubilize IND or FEN and suppress drug crystallization from a supersaturated state, which seemed to be an important mechanism for the properties enhancement caused by SmSD/FENHME. This knowledge should be useful for guiding further development of self-micellizing solid dispersions and for gaining deeper understanding of how HME technology can improve supersaturable drug delivery based on SmSDs strategy.

Sutureless fixation of amniotic membrane patch as a therapeutic contact lens by using a polymethyl methacrylate ring and fibrin sealant in a rabbit model.

PURPOSE: To introduce and evaluate a sutureless technique by using a polymethyl methacrylate (PMMA) ring and fibrin sealant to fix an amniotic membrane (AM) patch on the ocular surface as a therapeutic contact lens in a rabbit model. METHODS: PMMA rings were fabricated by duplicating an impression of a rabbit conjunctival fornix. The central cornea of the left eye in 16 rabbits was deepithelialized (diameter = 10 mm). A human AM patch was fixed to the ocular surface by using either a PMMA ring and fibrin sealant or interrupted 10-0 nylon sutures. The fibrin sealant was used to create the PMMA ring-AM complex but not to attach the AM/PMMA ring to the ocular surface. The rabbits were followed up with slit-lamp examination and fluorescein staining for 7 days. Reepithelialization and complications were recorded. RESULTS: The corneal epithelial defect was recovered in each rabbit of both groups after 5 days. In the sutureless group, all membranes remained in place and intact during the follow-up period. One eye was noted to have a partial conjunctival epithelial defect caused by exposure to the PMMA ring. In contrast, >50% of rabbits in the interrupted suture group exhibited complications including conjunctival edema, suture loosening, patch detachment, bleeding, and conjunctival epithelial defects. CONCLUSIONS: The sutureless technique that uses a PMMA ring and fibrin sealant for AM patch placement has a lower incidence of complications than the interrupted suture method. This sutureless technique may promote increased clinical use of AM patch by alleviating patients' pain and shortening surgical time.

High in vitro antibacterial activity of Pac-525 against Porphyromonas gingivalis biofilms cultured on titanium.

In order to investigate the potential of short antimicrobial peptides (AMPs) as alternative antibacterial agents during the treatment of peri-implantitis, the cytotoxic activity of three short AMPs, that is, Pac-525, KSL-W, and KSL, was determined using the MTT assay. The antimicrobial activity of these AMPs, ranging in concentration from 0.0039 mg/mL to 0.5 mg/mL, against the predominant planktonic pathogens, including Streptococcus sanguis, Fusobacterium nucleatum, and Porphyromonas gingivalis, involved in peri-implantitis was investigated. Furthermore, 2-day-old P. gingivalis biofilms cultured on titanium surfaces were treated with Pac-525 and subsequently observed and analysed using confocal laser scanning microscopy (CLSM). The average cell proliferation curve indicated that there was no cytotoxicity due to the three short AMPs. The minimum inhibitory concentration and minimum bactericidal concentration values of Pac-525 were 0.0625 mg/mL and 0.125 mg/mL, respectively, for P. gingivalis and 0.0078 mg/mL and 0.0156 mg/mL, respectively, for F. nucleatum. Using CLSM, we confirmed that compared to 0.1% chlorhexidine, 0.5 mg/mL of Pac-525 caused a significant decrease in biofilm thickness and a decline in the percentage of live bacteria. These data indicate that Pac-525 has unique properties that might make it suitable for the inhibition the growth of pathogenic bacteria around dental implants.

Synthesis, crystal structures, luminescence properties of two metal coordination polymers derived from 5-substituted isophthalate and flexible bis (triazole) ligands.

Two new metal complexes, [Ni(btx)(nip)(H2O)]n (1), {[Cd(btx)(mip)(H2O)]·H2O}n (2) (btx=1,4-bis(1,2,4-triazol-1-ylmethyl)benzene, H2nip=5-nitroisophthalic acid, H2mip=5-methyisophthalic acid) were synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction methods, IR spectroscopy, TGA and elemental analysis. Complex 1 features a 3D metal-organic framework with three-fold interpenetrating CdSO4-type topology. Complex 2 exhibits a 2D network with square grid units, which is further extended into a rare 3,5T1 three-dimensional supramolecular network via three modes of classical OH⋯O hydrogen bonds. In addition, luminescence properties of 1 and 2 have also been investigated in the solid state.

[Analysis of relationship between the detection of Enterococcus faecalis in post-treatment endodontic disease and clinical symptom or sign].

OBJECTIVE: To detect the Enterococcus faecalis (E. faecalis) in post-treatment endodontic disease, and to analyze the relationship between the occurrence of E. faecalis and clinical symptom. METHODS: 108 teeth which need root canal retreatment were collected, and the clinical symptoms and physical signs were recorded. Bacterium samples from root canal were taken, and genome DNA from bacterial samples were extracted. The occurrence of E. faecalis by means of the polymerase chain reaction was investigated. RESULTS: The detection rate of E. faecalis in cases of root canal retreatment was 47.2%, while in cases with symptoms or signs, or cases with both symptoms and signs, the root canal E. faecalis detection rates were 52.6%, 57.9%, 62.5%. The detection rates of E. faecalis between cases with clinical symptom and without clinical symptom demonstrated statistical significance (P < 0.05). The detection rates between cases with both clinical symptom and manifestly aneretic root and cases without clinical symptom and manifestly aneretic root had statistical significance (P < 0.05). In the group of clinical symptom, the detection rate of E. faecalis in cases with biting pain was 66.7%, clearly higher than those without biting pain (P < 0.05). CONCLUSION: The occurrence of E. faecalis in cases of root canal retreatment correlates with clinical symptoms.

[Degradation of electrodeposited calcium phosphate and calcium phosphate-chitosan coatings in vitro].

OBJECTIVE: To investigate the degradation of electrodeposited calcium phosphate (ECP) coating and calcium phosphate/chitosan (ECPC) coating in vitro. METHODS: Osteoclasts were isolated from neonatal rabbit long bone cavities and incubated with ECP and ECPC coatings. Calcium ion concentrations in the culture medium were analyzed at 3 days and 6 days. The osteoclastic resorption was observed with scanning electron microscope. RESULTS: Both coatings demonstrated osteoclastic resorption lacunae. The calcium ion concentrations of the culture mediums were decreased when incubated with calcium phosphate coatings (P < 0.05). Compared with coatings cultured with osteoclasts, the calcium ion concentrations of those cultured without osteoclasts were higher on day 3 (P > 0.05) but lower on day 6 (P < 0.05). CONCLUSIONS: Both ECP and ECPC coatings can be resorbed by osteoclasts in vitro and can dissolve in the culture medium.