Phosphorylation of collagen fibrils enhances intrafibrillar mineralization and dentin remineralization

The hierarchical assembly of nanoapatite within a type I collagen matrix was achieved through biomimetic mineralization in vitro, cooperatively regulated by non-collagenous proteins and small biomolecules. Here, we demonstrated that IP6 could significantly promote intrafibrillar mineralization in two- and three-dimensional collagen models through binding to collagen fibrils via hydrogen bonds (the interaction energy ∼10.21 kJ mol-1), as confirmed by the FTIR spectra and isothermal experimental results. In addition, we find that IP6 associated with dental collagen fibrils can also enhance the remineralization of calcium-depleted dentin and restore its mechanical properties similar to the natural dentin within 4 days. The promoting effect is mainly due to the chemical modification of IP6, which alters the interfacial physicochemical properties of collagen fibrils, strengthening the interaction of calcium phosphate minerals and mineral ions with collagen fibrils. This strategy of interfacial regulation to accelerate the mineralization of collagen fibrils is essential for dental repair and the development of a clinical product for the remineralization of hard tissue.

STMP and PVPA as Templating Analogs of Noncollagenous Proteins Induce Intrafibrillar Mineralization of Type I Collagen via PCCP Process

The phosphorylated noncollagenous proteins (NCPs) play a vital role in manipulating biomineralization, while the mechanism of phosphorylation of NCPs in intrafibrillar mineralization of collagen fibril has not been completely deciphered. Poly(vinylphosphonic acid) (PVPA) and sodium trimetaphosphate (STMP) as templating analogs of NCPs induce hierarchical mineralization in cooperation with indispensable sequestration analogs such as polyacrylic acid (PAA) via polymer-induced liquid-like precursor (PILP) process. Herein, STMP-Ca and PVPA-Ca complexes are proposed to achieve rapid intrafibrillar mineralization through polyelectrolyte-Ca complexes pre-precursor (PCCP) process. This strategy is further verified effectively for remineralization of demineralized dentin matrix both in vitro and in vivo. Although STMP micromolecule fails to stabilize amorphous calcium phosphate (ACP) precursor, STMP-Ca complexes facilely permeate into intrafibrillar interstices and trigger phase transition of ACP to hydroxyapatite within collagen. In contrast, PVPA-stabilized ACP precursors lack liquid-like characteristic and crystallize outside collagen due to rigid conformation of PVPA macromolecule, while PVPA-Ca complexes infiltrate into partial intrafibrillar intervals under electrostatic attraction and osmotic pressure as evidenced by intuitionistic 3D stochastic optical reconstruction microscopy (3D-STORM). The study not only extends the variety and size range of polyelectrolyte for PCCP process but also sheds light on the role of phosphorylation for NCPs in biomineralization.

Time evolution of moduli of a polymer-induced liquid precursor (PILP) of calcium carbonate

In situ AFM observations show that when PILP droplets contact a surface, their initial properties are either a liquid with a high interfacial tension (350 mJ m-2) or a soft gel-like material with a low modulus (less than 0.2 MPa). These findings suggest that PILP may initially be liquid-like to infiltrate collagen fibrils, enabling the production of interpenetrating composites, and/or become viscoelastic, to provide a means for moulding minerals.

Reversion of ACP Nanoparticles into Prenucleation Clusters via Surfactant for Promoting Biomimetic Mineralization: A Physicochemical Understanding of Biosurfactant Role in Biomineralization Process

Amphiphilic biomolecules are abundant in mineralization front of biological hard tissues, which play a vital role in osteogenesis and dental hard tissue formation. Amphiphilic biomolecules function as biosurfactants, however, their biosurfactant role in biomineralization process has never been investigated. This study, for the first time, demonstrates that aggregated amorphous calcium phosphate (ACP) nanoparticles can be reversed into dispersed ultrasmall prenucleation clusters (PNCs) via breakdown and dispersion of the ACP nanoparticles by a surfactant. The reduced surface energy of ACP@TPGS and the electrostatic interaction between calcium ions and the pair electrons on oxygen atoms of C-O-C of D-α-tocopheryl polyethylene glycol succinate (TPGS) provide driving force for breakdown and dispersion of ACP nanoparticles into ultrasmall PNCs which promote in vitro and in vivo biomimetic mineralization. The ACP@TPGS possesses excellent biocompatibility without any irritations to oral mucosa and dental pulp. This study not only introduces surfactant into biomimetic mineralization field, but also excites attention to the neglected biosurfactant role during biomineralization process.

[Clinical features and prognostic analysis of checkpoint inhibitor pneumonitis in patients with non-small cell lung cancer]

Objective: To describe the clinical characteristics of patients with non-small cell lung cancer (NSCLC) who developed checkpoint inhibitor pneumonitis (CIP) and to explore potential prognostic factors. Methods: NSCLC patients who were complicated with CIP after immune checkpoint inhibitors (ICIs) therapy in our institute were enrolled in this study from 1 July 2018 to 30 November 2022. Clinical data of NSCLC-CIP patients were collected, including clinical and radiological features and their outcomes. Results: Among the 70 enrolled NSCLC-CIP patients, there were 57 males (81%) and 13 females (19%). The mean age at the diagnosis of CIP was (65.2±6.3) years. There were 46 smokers (66%), 26 patients (37%) with emphysema, 19 patients (27%) with previous interstitial lung disease, and 26 patients (37%) with a history of thoracic radiation. The mean interval from the first application of checkpoint inhibitor to the onset of CIP was (122.7±106.9) days (range: 2-458 days). The main chest CT manifestations were coincided with non-specific interstitial pneumonia (NSIP) pattern and organizing pneumonia (OP) pattern. Most patients had grade 2 (21 cases) or grade 3 (34 cases) CIP. Seventeen patients had been concurrent with other immune-related adverse events such as rash, hepatitis, colitis, and thyroiditis. Half of the enrolled patients (36 patients/51%) had fever, and most patients had elevated C-reactive protein (52 patients/72%) and all patients had elevated erythrocyte sedimentation rate (70 patients/100%). Serum lactate dehydrogenase was elevated in 34 CIP patients. Prednisone≥1 mg·kg-1·d-1 (or equivalent) was the most commonly used initial treatment in CIP patients (50 patients/71.4%). Complications with pulmonary infections (OR=4.44, P=0.03), use of anti-fungal drugs (OR=5.10, P=0.03) or therapeutic dose of sulfamethoxazole (OR=4.86, P=0.04), longer duration of prednisone≥1 mg·kg-1·d-1 (or equivalent) (Z=-2.33, P=0.02) were probable potential risk factors for poor prognosis. Conclusions: Older males with smoking history might be predisposed to develop NSCLC-CIPs after ICIs therapy. NSIP pattern and OP pattern were common chest CT manifestations. Complications with pulmonary infections (especially fungal infection or Pneumocystis jirovecii pneumonia), longer duration, longer duration of high-dose corticosteroids were likely potential risk factors for poor prognosis.

[Clinical analysis of COVID-19 in patients with preexisting interstitial lung abnormalities]

Objective: To describe the clinical characteristics of SARS-CoV-2 infected patients with interstitial lung abnormalities (ILA) during the COVID-19 pandemic. Methods: We respectively enrolled ILA patients who had been regularly followed up in Peking Union Medical College Hospital for more than six months since January 2021. Clinical data of these ILA patients were collected after the outbreak of COVID-19 pandemic (from December 2022 to January 2023), thirty-eight patients with preexisting ILA were enrolled. Among them, there were 34 ILA patients (20 males and 14 females) who were infected with SARS-CoV-2 during this period, with an average age of (64.0±8.8) years old (range: 41-80). There were 12 (35.3%) ILA patients who were suffered from COVID-19(pneumonia group) and others were the non-pneumonia group. The clinical characteristics, including vaccination status, features of COVID-19 and outcomes of the two groups were compared. Results: Regarding the subcategories of ILA, there were 7 cases of subpleural fibrotic ILA, 10 cases of subpleural non-fibrotic ILA, and 17 cases of non-subpleural ILA. Before SARS-CoV-2 infection, the average pulse oxygen saturation at rest was (97.38±0.87)% (range: 96%-99%); average forced vital capacity (FVC) was (97.6±18.1)% predicted (range: 65%-132%); and average diffusion capacity for carbon monoxide (DLCO) was (76.2±16.3)% predicted (range: 53%-108%). Nineteen patients had been vaccinated with 3 doses of SARS-CoV-2 vaccines, and 5 of them developed COVID-19. One patient had received one dose of vaccine and did not develop COVID-19. The other 14 patients had not been vaccinated, and seven of them developed COVID-19. Of the 12 patients with COVID-19, six were diagnosed with severe COVID-19, and the other 6 ILA patients were diagnosed with moderate COVID-19. Among them, 1 patient was complicated by deep vein thrombosis of left lower limb. All 6 patients with severe COVID-19 who were cured after systemic corticosteroids. As for the other six moderate COVID-19 patients, all were cured and/or improved greatly: two were treated with short-term oral corticosteroids, one was prescribed a dose of compound betamethasone, and the other two were not treated with systemic corticosteroids. Conclusion: Patients with ILA were predisposed to develop COVID-19 after infection with SARS-CoV-2, and more than half of them had severe COVID-19.

Intrafibrillar mineralization of type I collagen with calcium carbonate and strontium carbonate induced by polyelectrolyte-cation complexes

Calcium carbonate (CaCO3), possessing excellent biocompatibility, bioactivity, osteoconductivity and superior biodegradability, may serve as an alternative to hydroxyapatite (HAp), the natural inorganic component of bone and dentin. Intrafibrillar mineralization of collagen with CaCO3 was achieved through the polymer-induced liquid precursor (PILP) process for at least 2 days. This study aims to propose a novel pathway for rapid intrafibrillar mineralization with CaCO3 by sequential application of the carbonate-bicarbonate buffer and polyaspartic acid (pAsp)-Ca suspension. Fourier transform infrared (FTIR) spectroscopy, zeta potential measurements, atomic force microscopy/Kelvin probe force microscopy (AFM/KPFM), and three-dimensional stochastic optical reconstruction microscopy (3D STORM) demonstrated that the carbonate-bicarbonate buffer significantly decreased the surface potential of collagen and CO32-/HCO3- ions could attach to collagen fibrils via hydrogen bonds. The electropositive pAsp-Ca complexes and free Ca2+ ions are attracted to and interact with CO32-/HCO3- ions through electrostatic attractions to form amorphous calcium carbonate that crystallizes gradually. Moreover, like CaCO3, strontium carbonate (SrCO3) can deposit inside the collagen fibrils through this pathway. The CaCO3-mineralized collagen gels exhibited better biocompatibility and cell proliferation ability than SrCO3. This study provides a feasible strategy for rapid collagen mineralization with CaCO3 and SrCO3, as well as elucidating the tissue engineering of CaCO3-based biomineralized materials.

ACP-Mediated Phase Transformation for Collagen Mineralization: A New Understanding of the Mechanism

Despite significant efforts utilizing advanced technologies, the contentious debate surrounding the intricate mechanism underlying collagen fibril mineralization, particularly with regard to amorphous precursor infiltration and phase transformation, persists. This work proposes an amorphous calcium phosphate (ACP)-mediated pathway for collagen fibril mineralization and utilizing stochastic optical reconstruction microscopy technology, and has experimentally confirmed for the first time that the ACP nanoparticles can infiltrate inside collagen fibrils. Subsequently, the ACP-mediated phase transformation occurs within collagen fibrils to form HAP crystallites, and significantly enhances the mechanical properties of the mineralized collagen fibrils compared to those achieved by the calcium phosphate ion (CPI)-mediated mineralization and resembles the natural counterpart. Furthermore, demineralized dentin can be effectively remineralized through ACP-mediated mineralization, leading to complete restoration of its mechanical properties. This work provides a new paradigm of collagen mineralization via particle-mediated phase transformation, deepens the understanding of the mechanism behind the mineralization of collagen fibrils, and offers a new strategy for hard tissue repair.

Hyaluronic acid-mediated collagen intrafibrillar mineralization and enhancement of dentin remineralization

Non-collagenous proteins (NCPs) in the extracellular matrix (ECM) of bone and dentin are known to play a critical regulatory role in the induction of collagen fibril mineralization and are embedded in hyaluronic acid (HA), which acts as a water-retaining glycosaminoglycan and provides necessary biochemical and biomechanical cues. Our previous study demonstrated that HA could regulate the mineralization degree and mechanical properties of collagen fibrils, yet its kinetics dynamic mechanism on mineralization is under debate. Here, we further investigated the role of HA on collagen fibril mineralization and the possible mechanism. The HA modification can significantly promote intrafibrillar collagen mineralization by reducing the electronegativity of the collagen surface to enhance calcium ions (Ca2+) binding capacity to create a local higher supersaturation. In addition, the HA also provides additional nucleation sites and shortens the induction time of amorphous calcium phosphate (ACP)-mediated hydroxyapatite (HAP) crystallization, which benefits mineralization. The acceleration effect of HA on intrafibrillar collagen mineralization is also confirmed in collagen hydrogel and in vitro dentin remineralization. These findings offer a physicochemical view of the regulation effect of carbohydrate polymers in the body on biomineralization, the fine prospect for an ideal biomaterial to repair collagen-mineralized tissues.

The effect of calcium phosphate ion clusters in enhancing enamel conditions versus Duraphat and Icon

This study aimed to evaluate and compare the remineralisation, mechanical, anti-aging, acid resistance and antibacterial properties of calcium phosphate ion clusters (CPICs) materials with those of Duraphat and Icon. The remineralisation and mechanical properties were investigated using scanning electron microscopy, Fourier-transform infrared (FTIR) spectroscopy and nanoindentation. CPICs induced epitaxial crystal growth on the enamel surface, where the regrown enamel-like apatite layers had a similar hardness and elastic modulus to natural enamel (p > 0.05). Acid resistance and anti-aging properties were tested based on ion dissolution and surface roughness. CPICs exhibited similar calcium and phosphate ion dissolution to the control (p > 0.05), and its roughness decreased after thermocycling (p < 0.05), thereby decreasing the risk of enamel surface demineralisation. The minimum inhibitory concentration was 0.1 mg/ml, and the minimum bactericidal concentration ranged from 0.05 to 0.1 mg/ml. Overall, this biomimetic CPICs is a promising alternative to dental demineralisation.

Fabrication of ACP-CCS-PVA composite membrane for a potential application in guided bone regeneration

The barrier membranes of guided bone regeneration (GBR) have been widely used in clinical medicine to repair bone defects. However, the unmatched mechanical strength, unsuitable degradation rates, and insufficient regeneration potential limit the application of the current barrier membranes. Here, amorphous calcium phosphate-carboxylated chitosan-polyvinyl alcohol (ACP-CCS-PVA) composite membranes are fabricated by freeze-thaw cycles, in which the ATP-stabilized ACP nanoparticles are uniformly distributed throughout the membranes. The mechanical performance and osteogenic properties are significantly improved by the ACP incorporated into the CCS-PVA system, but excess ACP would suppress cell proliferation and osteogenic differentiation. Our work highlights the pivotal role of ACP in GBR and provides insight into the need for biomaterial fabrication to balance mechanical strength and mineral content.

A comparative study of pilomatricoma and epidermoid cyst with ultrasound

AIM

To explore and compare the ultrasonic (US) features of pilomatricoma (PM) and epidermoid cyst (EC) in the differential diagnosis and improve the accuracy of US diagnosis of PM.

MATERIALS AND METHODS

Three hundred and nine patients who underwent US examination before surgery with a histopathological diagnosis of PM or EC after surgery were analysed retrospectively. The patients were categorised into the training and validation sets according to the inspection times. Univariate analysis was undertaken on the US and clinical features of PM and statistically significant variables (p<0.05) were included in the multivariate logistic regression model to establish a diagnostic model.

RESULTS

The results demonstrated that the multivariate logistic regression model for PM was statistically significant (p<0.001). The risk factors included posterior echo attenuation and hypoechoic halos (odds ratio [OR] = 9.277, 10.254) and the protective factors included age, diameter thickness, and posterior echo enhancement (OR=0.936, 0.302, 0.156). The performance of the diagnostic model was tested using the training set (area under the receiver operating characteristic curve [AUC] = 0.974, 95% confidence interval [CI] = 0.955-0.994) and the validation set (AUC = 0.967, 95% CI = 0.926-1.000), which demonstrated good discriminant ability.

CONCLUSIONS

The diagnostic accuracy for PM was higher than that for EC when the nodule is characterised by posterior echo attenuation, hypoechoic halos, smaller thickness, and younger age. The US diagnostic model developed may be used to guide the diagnosis of PM.

Regulation of Hydroxyapatite Nucleation In Vitro through Ameloblastin-Amelogenin Interactions

Amelogenin (Amel) and ameloblastin (Ambn) are two primary extracellular enamel matrix proteins that play crucial roles for proper thickness, prismatic structure, and robust mechanical properties. Previous studies have shown that Amel and Ambn bind to each other, but the effect of their coassembly on the nucleation of hydroxyapatite (HAP) is unclear. Here, we systematically investigated the coassembly of recombinant mouse Amel and Ambn in various ratios using in situ atomic force microscopy, dynamic light scattering, and transmission electron microscopy. The size of protein particles decreased as the Ambn:Amel ratio increased. To define the coassembly domain on Ambn, we used Ambn-derived peptides and Ambn variants to examine their effects on the amelogenin particle size distribution. We found that the peptide sequence encoded by exon 5 of Ambn affected Amel self-assembly but the variant lacking this sequence did not have any effect on Amel self-assembly. Furthermore, through monitoring the pH change in bulk mineralization solution, we tracked the nucleation behavior of HAP in the presence of Ambn and Amel and found that their coassemblies at different ratios showed varying abilities to stabilize amorphous calcium phosphate. These results demonstrated that Ambn and Amel coassemble with each other via a motif within the sequence encoded by exon 5 of Ambn and cooperate in regulating the nucleation of HAP crystals, enhancing our understanding of the important role of enamel matrix proteins in amelogenesis.

Intrafibrillar Mineralization and Immunomodulatory for Synergetic Enhancement of Bone Regeneration via Calcium Phosphate Nanocluster Scaffold

Inspired by the bionic mineralization theory, organic-inorganic composites with hydroxyapatite nanorods orderly arranged along collagen fibrils have attracted extensive attention. Planted with an ideal bone scaffold will contribute greatly to the osteogenic microenvironment; however, it remains challenging to develop a biomimetic scaffold with the ability to promote intrafibrillar mineralization and simultaneous regulation of immune microenvironment in situ. To overcome these challenges, a scaffold containing ultra-small particle size calcium phosphate nanocluster (UsCCP) is prepared, which can enhance bone regeneration through the synergetic effect of intrafibrillar mineralization and immunomodulatory. By efficient infiltration into collagen fibrils, the UsCCP released from the scaffold achieves intrafibrillar mineralization. It also promotes the M2-type polarization of macrophages, leading to an immune microenvironment with both osteogenic and angiogenic potential. The results confirm that the UsCCP scaffold has both intrafibrillar mineralization and immunomodulatory effects, making it a promising candidate for bone regeneration.

[Retrospective analysis and a cross-sectional questionnaire survey of lung cancer concomitant with interstitial lung disease]

Objective: To describe the clinical characteristics and prognosis of lung cancer concomitant with interstitial lung disease (LC-ILD), and to understand the current status of knowledge of LC-ILD by physicians in the departments related to the treatment of the disease. Methods: We conducted a retrospective analysis of in-hospitalized pathology identified lung cancer (LC) patients who were admitted to our hospital between January 2014 and December 2018. After reviewing their chest CT imagings and pathological reports, 70 patients who were concomitant with interstitial lung disease (ILD) were enrolled in our study. On the other hand, a cross-sectional survey using an online questionnaire was conducted in LC-ILD management doctors who came from 29 provincial hospitals. The perceptions of demographic features, LC characteristics and management, ILD characteristics and management, and the prognosis of LC-ILD were investigated. Results: Among the 70 enrolled LC-ILD cases, there were 52 males, and the mean age was (64.3±7.63) years (ranged from 49 years to 84 years). There were 51 patients who were older than 59 years. The most common pathological pattern of LC was adenocarcinoma. Most of them were diagnosed with LC and ILD simultaneously, and they were usually treated with chemotherapy while unresectable. There were 11 patients (15.7%) with positive EGFR or ALK mutation. Forty-five patients (64.3%) died during the follow-up, and 33 were died from LC progression. There were no significant differences between the surgical group and non-surgical group on age, pathological patterns, EGFR or ALK mutation. However, LC-ILD patients in the surgical group were diagnosed with earlier TNM classification and with better prognosis. A total of 1 014 doctors answered the questionnaire completely. In the feedback, patients aged 60 years and older (785 doctors/77.4%), and male patients (720 doctors/71%) were the predominant LC-ILD patients. Adenocarcinoma (390 doctors/38.5%), adenocarcinoma or squamous-cell cancer (SCC) (182 doctors/17.9%), and SCC (151 doctors/14.9%) were considered as the common pathological patterns of LC-ILD patients. In most doctors' feedback, the EGFR or ALK mutation was not common for LC-ILD: low (646 doctors/63.7%) or hardly (306 doctors/30.5%) positive mutation. The diagnosis of ILD was earlier than LC (506 doctors/49.9%) or there was no identified precedence of LC and ILD diagnosis (208 doctors/20.5%). Most of the doctors (693 doctors/68.3%) agreed that the vital factor for surgery or not was the severity of ILD for LC-ILD patients. There were great divergences on the treatment protocol both for the advanced LC and ILD. The patients with LC-ILD were died mostly from LC progression and ILD exacerbation (542 doctors/53.5%), followed by ILD exacerbation (237 doctors/23.4%) or LC progression (226 doctors/22.3%). Conclusions: The elderly male patients were predisposed to LC-ILD, and adenocarcinoma was the common pathological pattern. The LC-ILD patients with non-advanced LC who were performed with surgery had better prognosis. However, it is recommended to consider whether to perform surgery in combination with the severity of the ILD.

[Host factors and characteristics of hospitalized patients with pneumocystis jirovecii pneumonia]

Objectives: To describe the underlying diseases, microbiologic examination and severity of hospitalized patients with Pneumocystis jirovecii pneumonia (PJP) in a tertiary Chinese hospital. Methods: We conducted a retrospective analysis of 485 identified PJP patients who were admitted to our hospital between January 2013 and December 2021. Results: Among the 485 enrolled PJP cases, there were 237 males and 248 females, aging (53.3±16.2) years (range from 14 y to 88 y). They were divided into 8 subgroups with variable underlying diseases. There were 209 cases with connective tissue diseases(CTD), 27 cases with non-hematologic malignancies, 38 cases with hematologic malignancies, 81 cases with kidney diseases, 33 cases with idiopathic interstitial pneumonia(IIP), 30 cases infected with human immunodeficiency virus (HIV), and 42 cases with miscellaneous underlying diseases. In the CTD group, there was more females than males, while male patients were predominant in both the malignant and the HIV groups. The Pneumocystis was identified in 44.95%(218/485) sputum samples and 92.01%(265/288) bronchoscopic samples. Pneumocystis asci were observed at direct microscopic examination with Grocott's methenamine silver stain in 4.95%(24/485)sputum samples and 9.72%(28/288)bronchoscopic samples. Pneumocystis DNA fragments were identified by PCR analysis in 43.09%(209/485)sputum samples and 90.63%(261/288)bronchoscopic samples. Among the 8 groups, cytomegaviremia and respiratory failure were most common in the HIV-infected PJP group, but the rates of mechanic ventilation, intensive care unit (ICU) admission and death were the lowest. There were less PJP patients in the IIP group (IIP-PJP) who received mechanic ventilation and admitted to ICU than the other groups except HIV-infected PJP group. However, the mortality rate was highest for the IIP-PJP group. Conclusions: CTD was the most common predisposed underlying disease for our enrolled PJP cases. Cytomegaviremia and respiratory failure were common in HIV-infected PJP patients, but the prognosis of HIV-PJP was slightly better than the others. The disease was more severe, rapidly progressive and fatal in the IIP-PJP group.

[Clinical analysis of autoimmune diseases associated with interstitial lung diseases initially presented with idiopathic pulmonary fibrosis]

Objectives: To describe the clinical characteristics of patients with autoimmune diseases associated interstitial lung diseases (AID-ILD) initially presented with idiopathic pulmonary fibrosis (IPF) in a tertiary Chinese hospital. Methods: We conducted a retrospective analysis of 14 patients diagnosed with AID-ILD during the IPF follow-up between January 2016 and December 2021. Among the 14 enrolled AID-ILD cases, there were 13 males and 1 female, (69.71±9.07) years old (range from 55 y to 87 y). Results: Detailed clinical consultation and further laboratory analysis were performed during the follow-up when the IPF patients showed exaggerated dyspnea (7 cases), fever of unknown causes (6 cases), microscopic hematuria (5 cases), arthralgia and swelling (4 cases), arthralgia (2 cases), morning stiffness (2 cases) and renal failure (2 cases). Finally, 6 patients showed positive MPO-ANCA, one patient showed positive PR3-ANCA and 7 patients showed positive anti-CCP. During the IPF periods, 7 patients had received antifibrotic agents and 5 patients had been prescribed with N-acetylcysteine, and 1 patient had received antifibrotic agents after N-acetylcysteine. Among them, no medication was prescribed for one IPF patient. After they were diagnosed with AID-ILD, glucocorticoids and/or immunosuppressants were added for 13 of them. Thirteen of cases improved or stable after these treatments, but one didn't show significant changes. Conclusions: AID-UIP, especially ANCA-UIP, AAV-UIP or RA-UIP should be considered when the IPF patients showed fever of unknown origin, microscopic hematuria and/or arthritis related symptoms. They might benefit from the add-on glucocorticoids and/or immunosuppressants.

Promotion of collagen mineralization and dentin repair by succinates

Biomineralization of collagen fibers is regulated by non-collagenous proteins and small biomolecules, which are essential in bone and teeth formation. In particular, small biomolecules such as succinic acid (SA) exist at a high level in hard tissues, but their role is yet unclear. Here, our work demonstrated that SA could significantly promote intrafibrillar mineralization in two- and three-dimensional collagen models, where the relative mineralization rate was 16 times faster than the control group. Furthermore, the FTIR spectra and isothermal experimental results showed that collagen molecules could interact with SA via a hydrogen bond and that the interaction energy was about 4.35 kJ mol^-1. As expected, the SA-pretreated demineralized dentin obtained full remineralization within two days, whereas it took more than four days in the control group, and their mechanical properties were considerably enhanced compared with those of the demineralized one. The possible mechanism of the promotion effect of SA was ultimately illustrated, with SA modification strengthening the capacity of the collagen matrix to attract more calcium ions, which might create a higher local concentration that could accelerate the mineralization of collagen fibers. These findings not only advance the understanding of the vital role of small biomolecules in collagen biomineralization but also facilitate the development of an effective strategy to repair hard tissues.

[Histological regression and clinical benefits in patients with liver cirrhosis after long-term anti-HBV treatment]

Objective: Our study aims to determine histological regression and clinical improvement after long-term antiviral therapy in hepatitis B virus-related cirrhosis patients. Methods: Treatment-naïve chronic hepatitis B patients with histologically or clinically diagnosed liver cirrhosis were enrolled. Liver biopsies were performed after 5 years entecavir-based antiviral treatment. Patients were followed up every 6 months. Cirrhosis regression was evaluated based on Metavir system and P-I-R score. Clinical improvement was evaluated before and after the long-term treatment. Kruskal Wallis test and Wilcoxon signed-rank test were used for continuous variables, Fisher's exact test was used for categorical variables and multivariate analysis was performed using logistic regression analysis. Results: Totals of 73 patients with HBV-related liver cirrhosis were enrolled. Among them, 30 (41.1%) patients were biopsy proved liver cirrhosis and the remaining 43 (58.9%) cirrhotic patients were diagnosed by clinical features. Based on Metavir system and P-I-R score, 72.6% (53/73) patients attained histological regression. Furthermore, 30.1% (22/73) were defined as significant regression (Metavir decrease ≥2 stage), 42.5% (31/73) were mild regression (Metavir decrease 1 stage or predominantly regressive by P-I-R system if still cirrhosis after treatment) and 27.4% (20/73) were the non-regression. Compared to levels of clinical characteristics at baseline, HBV DNA, ALT, AST, liver stiffness(decreased from 12.7 to 6.4 kPa in significant regression, from 18.1 to 7.3 kPa in mild regression and from 21.4 to 11.2 kPa in non-regression)and Ishak-HAI score significantly decreased after 5 years of anti-HBV treatment, while serum levels of platelets and albumin improved remarkably (P<0.05). In multivariate analysis, only the pre-treatment liver stiffness level was associated with significant regression (OR=0.887, 95%CI: 0.802-0.981, P=0.020). Conclusions: After long-term antiviral therapy, patients with HBV-related cirrhosis are easily to attain improvements in clinical parameters, while a certain percentage of these patients still cannot achieve histological reversal.

Dual Functions of MDP Monomer with De- and Remineralizing Ability

Methacryloyloxydecyl dihydrogen phosphate (MDP) has been speculated to induce mineralization, but there has been no convincing evidence of its ability to induce intrafibrillar mineralization. Polymers play a critical role in biomimetic mineralization as stabilizers/inducers of amorphous precursors. Hence, MDP-induced biomimetic mineralization without polymer additives has not been fully verified or elucidated. By combining 3-dimensional stochastic optical reconstruction microscopy, surface zeta potentials, contact angle measurements, inductively coupled plasma-optical emission spectroscopy, transmission electron microscopy, atomic force microscopy, and Fourier transform infrared spectroscopy with circular dichroism, we show that amphiphilic MDP can not only demineralize dentin by releasing protons as an acidic functional monomer but also infiltrate collagen fibrils (including dentin collagen), unwind the triple helical structure by breaking hydrogen bonds, and finally immobilize within collagen. MDP-bound collagen functions as a huge collagenous phosphoprotein (HCPP), in contrast to chemical phosphorylation modifications. HCPP can induce biomimetic mineralization itself without polymer additives by alternatively attracting calcium and phosphate through electrostatic attraction. Therefore, we herein propose the dual functions of amphiphilic MDP monomer with de- and remineralizing ability. MDP in the free state can demineralize dentin substrates by releasing protons, whereas MDP in the collagen-bound state as HCPP can induce intrafibrillar mineralization. The dual functions of MDP monomer with de- and remineralization properties might create a new epoch in adhesive dentistry and preventive dentistry.

[Clinical characteristics of arrhythmia-onset sarcoidosis cases]

Objective: To describe the clinical characteristics of sarcoidosis patients with arrhythmia as the primary or main manifestation. Methods: We conducted a retrospective analysis of arrhythmia-onset sarcoidosis cases between January 2017 and December 2020. Their clinical manifestations, radiological features, treatment and prognosis were reviewed and analyzed. Results: This study consisted of 3 females and 1 male, with a mean age of 51 years (range from 42 to 58 years old). Arrhythmia was the first or main clinical manifestation for all 4 cases, involving Ⅲ° atrioventricular block (AVB) (n=1), Ⅱ° type Ⅱ AVB (n=1), and frequent ventricular premature beats and short array ventricular tachycardia (n=2). Three cases were diagnosed with respiratory sarcoidosis simultaneously during the diagnostic evaluation for arrhythmia. One case was diagnosed with sarcoidosis because of abnormal chest CT images due to cervical lymph node enlargement 5 years after arrhythmia. All 4 cases were confirmed as presenting epithelioid cell granulomatous inflammation by bronchoscopic biopsies. Late gadolinium enhancement with cardiac magnetic resonance (LGE-CMR) imaging was arranged for two cases. Both of them had typical imaging findings of cardiac sarcoidosis. Three cases were confirmed of cardiac involvement through positron emission computed tomography (PET)-CT. None of the enrolled four cases were arranged with endomyocardial biopsy. All four cases were improved with oral corticosteroids, immunosuppressants and anti-arrhythmic medications. Two cases underwent cardiac pacemaker implantation. Conclusions: The possibility of cardiac sarcoidosis should be considered in middle-aged and elderly patients with unexplained high-degree AVB or ventricular arrhythmia. Chest CT is recommended for routine screening for those cases. LGE-CMR and/or PET-CT is recommended for them to confirm the diagnosis of cardiac sarcoidosis. Corticosteroids and immunosuppressants are effective for these patients.

Tannic acid induces dentin biomineralization by crosslinking and surface modification

It is currently known that crosslinking agents can effectively improve the mechanical properties of dentin by crosslinking type I collagen. However, few scholars have focused on the influence of crosslinking agents on the collagen-mineral interface after crosslinking. Analysis of the Fourier transform infrared spectroscopy (FTIR) results showed that hydrogen bonding occurs between the tannic acid (TA) molecule and the collagen. The crosslinking degree of TA to collagen reached a maximum 41.28 ± 1.52. This study used TA crosslinked collagen fibers to successfully induce dentin biomineralization, and the complete remineralization was achieved within 4 days. The crosslinking effect of TA can improve the mechanical properties and anti-enzyme properties of dentin. The elastic modulus (mean and standard deviation) and hardness values of the remineralized dentin pretreated with TA reached 19.1 ± 1.12 GPa and 0.68 ± 0.06 GPa, respectively, which were close to those of healthy dentin measurements, but significantly higher than those of dentin without crosslinking (8.91 ± 1.82 GPa and 0.16 ± 0.01 GPa). The interface energy between the surface of collagen fibers and minerals decreased from 10.59 mJ m^-2 to 4.19 mJ m^-2 with the influence of TA. The current work reveals the importance of tannic acid crosslinking for dentin remineralization while providing profound insights into the interfacial control of biomolecules in collagen mineralization.

Deep and compact dentinal tubule occlusion via biomimetic mineralization and mineral overgrowth

Dentinal tubule (DT) occlusion by desensitizing agents has been widely applied to inhibit the transmission of external stimuli that cause dentin hypersensitivity (DH). However, most desensitizing agents merely accomplish porous blocking or the formation of a superficial tubular occlusion layer, resulting in a lack of mechanical and acid resistance and long-term stability. Herein, combining biomimetic mineralization and mineral overgrowth of the dentinal matrix was shown to effectively occlude DTs, resulting in the formation of a compact and deep occluding mineral layer that is strongly bound to the organic matrix on tubule walls. This DT occlusion method could achieve both mechanical resistance and acid resistance, demonstrating the potential of an inexpensive, long-term, and efficient therapy for treating DH.

Oriented Crystallization of Hydroxyapatite in Self-Assembled Peptide Fibrils as a Bonelike Material

Controlling oriented crystallization is key to producing bonelike composite materials with a well-organized structure. However, producing this type of composite material using synthetic biopolymers as scaffolds is challenging. Inspired by the molecular structure of collagen-I, a collagenlike peptide─(Pro-Hyp-Gly)₁₀ (POG10)─was designed to produce self-assembled fibrils that resemble the structure of collagen-I fibrils. In addition, the oriented mineralization of HAP crystals is formed in the fibrils that reproduces a bonelike material similar to collagen-I fibril mineralization. Unlike collagen-I fibrils, POG10 fibrils do not contain gap spaces. The molecular simulation results indicate that in addition to space confinement, the molecular field generated by POG10 can also confine the orientation of HAP, enriching our understanding of physical confinement and shedding light on the design of synthetic biopolymer scaffolds for bonelike material fabrication.

Characterizing the impact of high temperature during grain filling on phytohormone levels, enzyme activity and metabolic profiles of an early indica rice variety

Global warming results in high temperature stress (HTS), which presents severe challenges worldwide for modern agricultural production and will have significant impacts on the yield and quality of crops. Accumulation of photosynthetic products, activity of enzymes involved in sucrose-starch metabolism, phytohormone levels and metabolic profiling using LC-MS were analysed in the flag leaves and/or developing grains subjected to HTS during the grain-filling stage of an indica rice. HTS induced significant yield loss and reduced the grain quality, with lower amylose content. HTS reduced photosynthetic product accumulation in flag leaves and reduced starch accumulation in developing grains, compared to growth under normal temperatures. The activity of enzymes related to sucrose-starch metabolism were dis-regulated in developing grains grown under high temperature (HT). Moreover, phytohormone homeostasis in flag leaves and developing grains was also dramatically disturbed by HT. Metabolic profiling detected many metabolites with remarkably different relative fold abundances at different time points in the developing grain at HT versus normal temperatures, these metabolites were enriched in several HTS response pathways. The change in phytohormone ratio and auxin level might be associated with the reduction in photosynthetic products and their translocation, and ultimately with reduced starch accumulation in the developing grain. The detected metabolites might have different roles in response to the HTS in developing grain at different development stages. These results provide a theoretical reference and basis for future rice production towards higher quality and yield when grown under HTS.

Diagnostic value of maximum signal intensity on T1-weighted MRI images for differentiating parotid gland tumours along with pathological correlation

AIM

To investigate the efficacy of the maximum signal intensity of tumour on T1-weighted magnetic resonance imaging (MRI) images for differentiating Warthin's tumours (WTs) from pleomorphic adenomas (PAs) and malignant tumours (MTs).

MATERIALS AND METHODS

One hundred and fifty-four histopathologically confirmed parotid tumours, including 76 PAs, 45 WTs, and 33 MTs, were analysed. MRI results were compared with pathological findings. The maximum signal intensity of tumour and the average signal intensity of spinal cord were measured on T1-weighted images, then the tumour-to-spinal cord signal intensity ratio (T1-max-SIR) was calculated. The distribution of T1-max-SIRs among the three groups of tumours was analysed using the Mann-Whitney U-test. Receiver operating characteristic curves were generated to assess the ability of T1-max-SIRs to differentiate parotid tumours. In addition, the interobserver agreement between readers was assessed using interclass correlation coefficient (ICC).

RESULTS

T1-max-SIRs were higher in WTs than in PAs (p<0.001) and MTs (p<0.001), and no significant difference was found between PAs and MTs (p=0.151). The area under the curve (AUC) of T1-max-SIRs for differentiating WTs from PAs was 0.901, with a sensitivity of 91.1% and a specificity of 82.9%. The AUC of T1-max-SIRs for differentiating WTs from MTs was 0.851, with a sensitivity of 88.9% and a specificity of 78.8%. Readers had excellent interobserver agreement on T1-max-SIRs (ICC = 0.989; 95% confidence interval, 0.985-0.992).

CONCLUSIONS

T1-max-SIRs can be useful for differentiating WTs from PAs and MTs with high diagnostic efficiency.

Effect of aspartic acid on the crystallization kinetics of ACP and dentin remineralization

Type I collagen and non-collagen proteins are the main organic components of dentin. This study aimed to investigate the biomimetic remineralization of demineralized dentin by aspartic acid (Asp), which is abundant in non-collagenous proteins (NCPs). Asp was added to a mineralizing solution containing polyacrylic acid (PAA) to explore the mechanism of Asp regulating the pure amorphous calcium phosphate (ACP) phase transition process. The remineralization process and superstructure of the remineralized layer of demineralized dentin were evaluated and analyzed by transmission electron microscope (TEM) and scanning electron microscope (SEM), and the biological stability of the remineralized layer was investigated by collagenase degradation experiment. It demonstrated that Asp promoted the crystallization kinetics of PAA-stabilized amorphous calcium phosphate to hydroxyapatite (HAP), and shortened the remineralization time of demineralized dentin from 7 days to 2 days. The newly formed remineralized dentin had similar morphology and biological stability to the natural dentin layer. The presence of a large number of Asp residues in NCPs promoted the phase transformation of ACP, and further revealed the mechanism of action of NCPs in dentin biomineralization. This experiment also showed that Asp promoted the biomimetic remineralization of dentin; the morphology and hierarchical structure of remineralized layer was similar to that of natural teeth, and had good biological properties.

Epstein - Barr Virus (EBV) Associated B-Cell Lymphoma: An Unusual Involvement Of The Heart And Kidney In An HIV Positive Patient With Concurrent Cytomegalovirus (CMV) Pneumonia And Pneumocystis Jirovecii Pneumonia (PCP)

Introduction/Objective

We report a 68-year-old man with Human immunodeficiency virus (HIV) infection and significant weight loss during the past two years who presented with dyspnea. He was not receiving any treatment for HIV infection, and his viral load and CD4 count were 178000 copies/ml and 8 cells/mm3, respectively. The radiologic examination was concerning for Pneumocystis jirovecii pneumonia. The Bronchoalveolar lavage was positive for Pneumocystis jirovecii. The patient expired despite the comprehensive treatment, and the autopsy was requested.

Methods

The autopsy showed heavy lungs with diffuse consolidation and white discoloration involving all lobes. The left ventricular wall and right kidney cortex showed foci of white discoloration measuring 1 and 0.8 cm, respectively.

Results

The microscopic examination of lungs showed concurrent CMV pneumonia, and PCP confirmed by immunohistochemical staining for CMV and GMS special stain. The histologic evaluation of the heart and the right kidney and immunohistochemical staining for CD20 and CD3 in addition to in situ hybridization (ISH) for EBER revealed infiltrative malignant cells, which were positive for CD20 and EBER and negative for CD3. The EBV associated B-cell lymphoma involving the heart, and the right kidney was diagnosed

Conclusion

EBV is involved in human lymphomagenesis, particularly in HIV patients. There is a tendency for the lymphoma to involve the extranodal sites, including the CNS, gastrointestinal tract, liver, and bone marrow. However, the involvement of the heart and kidneys occurs very rarely. The autopsy findings of Lung co-infection with PCP and CMV and EBV associated lymphoma involving atypical locations is a rare and unique combination of AIDS-defining illnesses in this patient.

Omega-3 polyunsaturated fatty acids prevent progression of liver fibrosis and promote liver regeneration after partial hepatectomy in cirrhotic rats

OBJECTIVE

To assess the effect of omega-3 polyunsaturated fatty acids (n-3 PUFA) on liver regeneration of rats with liver cirrhosis after hepatectomy and antifibrosis.

MATERIALS AND METHODS

Omega-3 polyunsaturated fatty acids were intravenously injected in n-3 PUFA group 3 days before the operation to 1 day after partial hepatectomy. 70% hepatectomy was performed in rats, which were subsequently divided into 4 groups, namely normal and hepatectomy group (PH); liver cirrhosis and hepatectomy group (LC+PH); liver cirrhosis, n-3 PUFA (1 mL/kg), and hepatectomy group (LC+n-3 PUFA+PH); liver cirrhosis, n-3 PUFA (2 mL/kg) and hepatectomy group (LC+n-3PUFA*+PH). Body/liver weight ratios, serum parameters, histopathological examination, immunostaining, inflammatory cytokine and quantification of mRNA expression were also investigated.

RESULTS

Liver regeneration was significantly delayed compared with PH group 7 days after hepatectomy (PH) in LC+PH group. Besides, liver regeneration of LC+n-3 PUFA*+PH group increased significantly compared with LC+PH group 7 days after PH. In LC+PH group, liver cirrhotic was significantly higher compared with LC+n-3 PUFA+PH group 7 days after PH. In the meantime, liver cirrhosis of LC+n-3 PUFA*+PH group was significantly reduced compared with LC+n-3 PUFA+PH group 7 days after PH. Anti-inflammatory cytokine IL-10 was increased and pro-inflammatory cytokine IL-6 was decreased in LC+n-3 PUFA*+PH group compared with LC+PH group. N-3 PUFA also suppressed increments in mRNA expression for transforming growth factor-β and up-regulated the expression of matrix metalloproteinase-9 and matrix metalloproteinase-1 in the liver.

CONCLUSIONS

The mentioned results clearly show that n-3 PUFA reduces liver fibrosis and promotes liver regeneration, even under cirrhotic conditions. This could be a potentially useful treatment for liver cirrhosis.

[The clinical features and prognosis of 32 cases of pulmonary actinomycosis]

Objectives: To describe the clinical features and prognosis of pulmonary actinomycosis in a tertiary Chinese hospital. Methods: We conducted a retrospective analysis of 32 patients diagnosed with pulmonary actinomycosis between January 2013 and December 2019. General characteristics, clinical manifestations, lab data, chest CT imaging, treatment and follow-up information were reviewed and analyzed. Results: This study consisted of 19 males and 13 females, with a mean age of (58±12) years, ranging from 16 to 76 years. There were 26 cases with co-morbidities. Among them, there were 16 cases with pulmonary co-morbidity. Sixteen cases had a smoking history. Eight cases, 5 men and 3 women, with a mean age of (48±8) years, ranging from 41 to 58 years, received thoracic surgery for diagnosis. The remaining 24 cases who did not receive thoracic surgery consisted of 14 males and 8 females, with a mean age of (54±14)years, ranging from 16 to 76 years. Cough (25cases), expectoration (21 cases) and fever (16 cases) were the common clinical manifestations. The erythrocyte sedimentation rate (ESR) ranged from 2 to 114 mm/1 h, with a mean value of (28±31) mm/1 h. The ESR was elevated (>20 mm/1 h) in 15 cases. The C-reactive protein (CRP) ranged from 1 to 116 mg/L, with a mean value of (28±45) mg/L. The CRP was elevated (>8 mg/L) in 16 cases. Localized air-space consolidation (18 cases), pulmonary mass or nodules (16 cases) were the common chest CT manifestations. When compared with non-surgical cases, fever was the sole characteristic that was less common in cases with thoracic surgery (1 case in surgical group vs 11 cases in non-surgical group, P<0.05). Actinomyces spp. was found in 7 cases (87.5%) who received thoracic surgery, in 16 (61.5%) specimens collected through bronchoscopy and in 10 (55.6%) sputum samples of good quality. All of our enrolled cases were administrated with oral antibiotics, and 14 cases were prescribed with intravenous antibiotics initially. Among them, 27 cases were administrated with more than one antibiotic. Penicillin, ampicillin and amoxillin were prescribed for 25 cases. Finally, 30 cases showed improvement or cure in our hospital. Conclusions: Pulmonary actinomycosis tended to develop in aged patients with co-morbidities. Cough, expectoration, fever and localized air-space consolidation were the common clinical and radiological manifestations, respectively. Actinomyces spp. could be found more easily in the surgically resected tissues than other specimens. The prognosis of our enrolled cases was good after treatment with combined antibiotics.

Metabolomic profiling of goslings with visceral gout reveals a distinct metabolic signature

1.The objective of the experiment was to analyse serum profiles of goslings with visceral gout and compare them with those of healthy individuals to identify differentially-abundant metabolites as potential biomarkers. 2.Untargeted gas chromatography and time-of-flight mass spectrometry (GC-TOF-MS) metabolomic profiling was used to compare the serum metabolome of 15 goslings (Anser cygnoides) with gout and 15 healthy goslings (control). 3.Goslings with gout had a metabolic profile distinct from that of the controls, with 45 metabolite levels differing significantly (VIP > 1; P < 0.05) between both groups. Nine metabolites (hydrocortisone, glucose, trans-4-hydroxy-L-proline, galactose, 2-deoxy-D-galactose, beta-mannosylglycerate, d-glucoheptose, zymosterol, and hypoxanthine) were selected through receiver operating characteristics (ROC) analysis (area under curve (AUC) score ≥0.85) as potential biomarkers. Pathway analysis revealed that metabolites with differing levels were mainly involved in galactose, arginine and proline and purine metabolisms. 4.These results provided new insights into the pathogenesis of gout. Increased xanthine and hypoxanthine with decreased hydrocortisone provide promising biomarkers for gosling gout diagnosis. The findings suggested that hepatic metabolic disorders frequently occur in the development of avian gout.

[CD137 signaling promotes angiogenesis through regulating macrophage M1/M2 polarization]

Objective: To investigate whether CD137 signaling can promote angiogenesis via regulating macrophage M1/M2 polarization. Methods: (1) The primary peritoneal macrophages in mice induced by 3% thiglycollate broth were divided into three groups: control group, CD137 signaling activated group and CD137 signaling inhibited group. Various specific markers of M1 and M2 macrophages were detected to observe the phenotype change of macrophages, and the macrophages protein expression of CD137, CD86 and CD206 was detected by flow cytometry (FCM). The protein and mRNA expression of induced nitric oxide synthase (iNOS), arginase Ⅰ(Arg-1) was determined by Western blot and RT-PCR, respectively. The secretion levels of IL-12 and IL-10 in culture supernatant of macrophages were detected by ELISA. (2) Macrophages were co-cultured with the endothelial cells (bEnd.3), and macrophages were implanted in the upper chamber, endothelial cells were implanted in stromal glue of the lower chamber. The experiment was divided into three groups: the control group, CD137 signaling activated group and peroxisome proliferator-activated receptor-γ (PPAR-γ) inhibited group, and tube formation ability of endothelial cells in each group was determined. Results: (1) The purity of primary peritoneal macrophages in mice was (97.93±1.31)%. The expression of CD137 on the surface of macrophages was (97.40±2.70)%. (2) Compared with control group, the mRNA and protein expression levels of Arg-1 were significantly increased and the mRNA and protein expression of iNOS were significantly decreased in CD137 signaling activated group (all P<0.05). Compared with CD137 signaling activated group, the mRNA and protein expression of Arg-1 were significantly lower and the mRNA and protein expression levels of iNOS were significantly higher in CD137 signaling inhibited group (all P<0.05). FCM results showed that the average fluorescence intensity of CD206 was higher, while the average fluorescence intensity of CD86 was lower in CD137 signaling activated group than in control group (P<0.05, P<0.01, respectively); the expression of CD206 was significantly lower, while the expression of CD86 was higher, in the CD137 signaling inhibited group than in CD137 signaling activated group (P<0.05, P<0.01, respectively). ELISA results showed that the secretion of IL-10 was higher, and the secretion level of IL-12 was significantly lower in CD137 signaling activated group than in control group (both P<0.01); the secretion of IL-10 was significantly lower and the secretion of IL-12 was significantly higher in CD137 signaling inhibited group than in CD137 signaling activated group (both P<0.05). (3) Values of the formation of tube length and branch number were both longer in CD137 signaling activated group than control group (P<0.05). The formation of the tube length and branch number were less in PPAR-γ inhibited group than in CD137 signaling activated group (P<0.05). Conclusion: CD137 signaling can promote angiogenesis by regulating macrophage M1/M2 polarization.

Polydopamine Promotes Dentin Remineralization via Interfacial Control

Biomineralization has intrigued researchers for decades. Although mineralization of type I collagen has been universally investigated, this process remains a great challenge due to the lack of mechanistic understanding of the roles of biomolecules. In our study, dentine was successfully repaired using the biomolecule polydopamine (PDA), and the remineralized dentine exhibited mechanical properties comparable to those of natural dentine. Detailed analyses of the collagen mineralization process facilitated by PDA showed that PDA can promote intrafibrillar mineralization with a decreased heterogeneous nucleation barrier for hydroxyapatite (HAP) by reducing the interfacial energy between collagen fibrils and amorphous calcium phosphate (ACP), resulting in the conversion of an increasing amount of nanoprecursors into collagen fibrils. The present work highlights the importance of interfacial control in dentine remineralization and provides profound insight into the regulatory effect of biomolecules in collagen mineralization as well as the clinical application of dentine restoration.

Safety, feasibility, and effect of an enhanced nutritional support pathway including extended preoperative and home enteral nutrition in patients undergoing enhanced recovery after esophagectomy: a pilot randomized clinical trial

The aims of this pilot study are to evaluate the feasibility, safety, and effectiveness of conducting an enhanced nutritional support pathway including extended preoperative nutritional support and one month home enteral nutrition (HEN) for patients who underwent enhanced recovery after esophagectomy. We implemented extended preoperative nutritional support and one month HEN after discharge for patients randomized into an enhanced nutrition group and implemented standard nutritional support for patients randomized into a conventional nutrition group. Except the nutritional support program, both group patients underwent the same standardized enhanced recovery after surgery programs of esophagectomy based on published guidelines. Patients were assessed at preoperative day, postoperative day 7 (POD7), and POD30 for perioperative outcomes and nutritional status. To facilitate the determination of an effect size for subsequent appropriately powered randomized clinical trials and assess the effectiveness, the primary outcome we chose was the weight change before and after esophagectomy. Other outcomes including body mass index (BMI), lean body mass (LBM), appendicular skeletal muscle mass index (ASMI), nutrition-related complications, and quality of life (QoL) were also analyzed. The intention-to-treat analysis of the 50 randomized patients showed that there was no significant difference in baseline characteristics. The weight (-2.03 ± 2.28 kg vs. -4.05 ± 3.13 kg, P = 0.012), BMI (-0.73 ± 0.79 kg/m2 vs. -1.48 ± 1.11 kg/m2, P = 0.008), and ASMI (-1.10 ± 0.37 kg/m2 vs. -1.60 ± 0.66 kg/m2, P = 0.010) loss of patients in the enhanced nutrition group were obviously decreased compared to the conventional nutrition group at POD30. In particular, LBM (48.90 ± 9.69 kg vs. 41.96 ± 9.37 kg, p = 0.031) and ASMI (7.56 ± 1.07 kg/m2 vs. 6.50 ± 0.97 kg/m2, P = 0.003) in the enhanced nutrition group were significantly higher compared to the conventional nutrition group at POD30, despite no significant change between pre- and postoperation. In addition, European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 scores revealed that enhanced nutritional support improved the QoL of patients in physical function (75.13 ± 9.72 vs. 68.33 ± 7.68, P = 0.009) and fatigue symptom (42.27 ± 9.93 vs. 49.07 ± 11.33, P = 0.028) compared to conventional nutritional support. This pilot study demonstrated that an enhanced nutritional support pathway including extended preoperative nutritional support and HEN was feasible, safe, and might be beneficial to patients who underwent enhanced recovery after esophagectomy. An appropriately powered trial is warranted to confirm the efficacy of this approach.

Surface-anchored framework for generating RhD-epitope stealth red blood cells

Rhesus D (RhD) is one of the most important immunogenic antigens on red blood cells (RBCs). However, the supply of RhD-negative blood frequently faces critical shortages in clinical practice, and the positive-to-negative transition of the RhD antigen remains a great challenge. Here, we developed an alternative approach for sheltering the epitopes on RhD-positive RBCs using a surface-anchored framework, which is flexible but can achieve an optimal shield effect with minimal physicochemical influence on the cell. The chemical framework completely obstructed the RhD antigens on the cell surface, and the assessments of both blood transfusion in a mouse model and immunostimulation with human RhD-positive RBCs in a rabbit model confirmed the RhD-epitope stealth characteristics of the engineered RBCs. This work provides an efficient methodology for improving the cell surface for universal blood transfusion and generally indicates the potential of rationally designed cell surface engineering for transfusion and transplantation medicine.

Pancreatic sarcomatoid carcinoma: CT, MRI, and 18F-FDG PET/CT features

AIM

To investigate computed tomography (CT), magnetic resonance imaging (MRI), and combined 2-[¹⁸F]-fluoro-2-deoxy-d-glucose (¹⁸F-FDG) positron-emission tomography (PET)/CT features of pancreatic sarcomatoid carcinoma (PSC).

MATERIALS AND METHODS

The hospital database was searched retrospectively for the patients with PSC confirmed at histopathology after surgery. Ten patients who underwent unenhanced and enhanced CT (n=4), unenhanced and enhanced MRI (n=2), ¹⁸F-FDG PET/CT (n=2), and both enhanced CT and ¹⁸F-FDG PET/CT (n=2) were enrolled. Two patients underwent additional delayed PET/CT. The maximum standardised uptake value (SUVmax) was measured on PET/CT images.

RESULTS

Eleven lesions were detected in 10 patients. Solid and cystic components (n=6), intratumoural haemorrhage (n=1), nodular calcification (n=2), main pancreatic duct dilatation resulted from lesion obstruction (n=5) or compression (n=3), cholangiectasis (n=5), vascular and peripheral organ invasion (n=5 and 6, respectively), hepatic and lymphatic metastases (n=4 and 2, respectively) were detected. All five lesions in four patients who underwent PET/CT showed intense FDG uptake on PET/CT with SUVmax (16, range 10.9-21.1). Increase of FDG uptake (SUVmax = 18.9, 20.1, and 27.3, respectively) was revealed on the delayed scan of three lesions in two patients.

CONCLUSIONS

PSCs were more commonly ill-defined solid cystic masses, which caused pancreatic duct obstruction/compression without pancreatic parenchymal atrophy, and these masses on PET/CT showed high FDG uptake on both initial and delayed PET/CT.

Anisotropic Epitaxial Behavior in the Amorphous Phase-Mediated Hydroxyapatite Crystallization Process: A New Understanding of Orientation Control

The precise control of crystallization is a key in the construction and engineering of crystalline materials, especially in biomineralization. Although it is generally accepted that biomineral crystals have evolved from their amorphous precursors, there are intense debates about crystallographic orientation control. By using in situ high-resolution transmission electron microscopy, we herein reveal that hydroxyapatite (HAP) is produced through its epitaxial growth from amorphous calcium phosphate with a preferential c-axis orientation. Abnormally but interestingly, this anisotropic epitaxial crystallization priority along the c-axis is not affected by the existing HAP crystalline substrate, which is exactly the same on either {002} or {100} facets. Molecular dynamics simulations suggest this preference is correlated with the interfacial energetic controls at the amorphous-crystalline transition frontier. The orientation control of biominerals here shows the key role of the interface energy, rather that the organic molecules or matrices, which provides a complementary understanding of the general c-axis orientation control of HAP in various biomineralization cases and aids in the development of an alternative strategy for crystallization control of functional materials.

Promotion effect of immobilized chondroitin sulfate on intrafibrillar mineralization of collagen

Chondroitin sulfate (CS) is widespread in mineralized tissues and is considered to play crucial roles during the mineralization process. However, its role in biomineralization remains controversial. In the present study, CS is immobilized to collagen fibrils to mimic its state in biomineralization. The results demonstrate that immobilized CS on collagen fibrils accelerates calcium phosphate nucleation and significantly promotes collagen mineralization by accumulating calcium ions in collagen fibrils. The stochastic optical reconstruction microscopy results confirm that CS gives the specific nucleation sites for calcium phosphate to preferentially form, the improved intrafibrillar heterogeneous nucleation of calcium phosphate facilitates intrafibrillar mineralization. It is found remarkably accelerated remineralization of CS immobilized demineralized dentin is achieved. This study offers insight on the understanding of the function of the biomacromolecule CS on the biomineralization front. In addition, CS effectively promotes intrafibrillar mineralization, which highlights fine prospect for CS to reconstruct collagen-mineralized tissues as a natural material.

Identification and characterisation of a novel FT orthologous gene in London plane with a distinct expression response to environmental stimuli compared to PaFT

FLOWERING LOCUS T (FT) is a key integrator of environmental signals and internal cues, and codes for florigen-like activity which regulates the transition from vegetative to reproductive growth in flowering plants. Unlike annual plants, perennial tree species undergo several years of vegetative growth prior to the transition to the reproductive stage, as characterised by the ability to form flower buds. Thereafter, trees in temperate regions typically display an annual growth cycle involving distinct vegetative growth, flowering and dormancy stages. In London plane (Platanus acerifolia Willd.), a FT-like gene has previously been identified. Here, we report the isolation of a novel FT orthologous gene, PaFTL, and investigate the functions of PaFT and PaFTL through the analysis of expression profiles and transgenic phenotypes. PaFT displayed the highest levels of expression during tree dormancy, and similarly elevated expression levels were seen under conditions of low temperature and short days (LT/SD). In contrast, PaFTL transcripts were up-regulated during the floral transition phase, the early stages of inflorescence development and throughout the main flowering period, whereas expression levels were low and variable during dormancy and in response to LT/SD treatments. Ectopic expression of 35s::PaFTL in tobacco produced a phenotype similar to that with PaFT, namely, advanced floral initiation. Overall, the results suggest that PaFT and PaFTL have both conserved and diverse functions in floral initiation, floral development and dormancy regulation.

Calcium Phosphate Nanocluster-Loaded Injectable Hydrogel for Bone Regeneration

Bone is a hierarchical tissue in which the extracellular matrix consists of hydroxyapatite (HAP) crystals embedded in the collagen matrix. Artificial bone regeneration remains a great challenge due to the difficulty of balancing the chemical composition, biological compatibility, and mechanical performance of the implant. Biomineralization starts from the formation of a hydrogel-like biomacromolecule matrix in many cases, while the mineralization of HAP often builds from amorphous calcium phosphate (ACP) nanoclusters. Inspired by these discoveries, here we use a hydrogel loaded with ∼1 nm sized polymer-stabilized ACP nanoclusters (cluster-loaded hydrogel) as an injectable bone regeneration material. The hydrogel is biocompatible and stabilizes the ACP clusters such that they could efficiently infiltrate into collagen fibrils leading to intrafibrillar mineralization of HAP nanocrystals. Ex vivo results reveal that the cluster-loaded hydrogel has an excellent bone affinity as well as provides a suitable environment for the proliferation and differentiation of bone cells. In vivo experiments with rat bone show that the cluster-loaded hydrogel can generate HAP-based fillings within bone defects with perfect bonding to the surrounding tissue and a mechanical performance comparable with native bone. The fluidity of the hydrogel is further beneficial by providing a feasible minimally invasive bone healing procedure via syringe injection. The discovery and utilization of the cluster-loaded hydrogel described here provide a promising bioinspired approach for bone tissue regeneration.

Osteoporotic Bone Recovery by a Highly Bone-Inductive Calcium Phosphate Polymer-Induced Liquid-Precursor

Osteoporosis is an incurable chronic disease characterized by a lack of mineral mass in the bones. Here, the full recovery of osteoporotic bone is achieved by using a calcium phosphate polymer-induced liquid-precursor (CaP-PILP). This free-flowing CaP-PILP material displays excellent bone inductivity and is able to readily penetrate into collagen fibrils and form intrafibrillar hydroxyapatite crystals oriented along the c-axis. This ability is attributed to the microstructure of the material, which consists of homogeneously distributed ultrasmall (≈1 nm) amorphous calcium phosphate clusters. In vitro study shows the strong affinity of CaP-PILP to osteoporotic bone, which can be uniformly distributed throughout the bone tissue to significantly increase the bone density. In vivo experiments show that the repaired bones exhibit satisfactory mechanical performance comparable with normal ones, following a promising treatment of osteoporosis by using CaP-PILP. The discovery provides insight into the structure and property of biological nanocluster materials and their potential for hard tissue repair.