[Study on liver tissue derived-extracellular vesicles regulating the osteogenic differentiation ability of mesenchymal stem cells and promoting the healing of jaw bone defects]

Objective: To explore the biological process of liver tissue-derived extracellular vesicle (LT-EV) in promoting osteogenic differentiation of mesenchymal stem cells and healing of jaw defects to provide a feasible treatment method for the clinical treatment of jaw bone defects. Methods: Enzymatic hydrolysis and differential centrifugation were used to extract LT-EV, scanning electron microscopy, Western blotting, and nanoparticle tracking analyzers were used to identify and characterize LT-EV, and further to explore the biological functions of LT-EV through proteomics and Kyoto Encyclopedia of Genes and Genomes. Flow cytometry was used to detect LT-EV plasma concentration and to calculate the plasma half-life of LT-EV. Small animal in vivo imaging system was used to detect the biological distribution of LT-EV 24 hours after injection. Six C57BL/6 mice were divided into control group and LT-EV group (3 mice in each group) by simple random sampling method. All mice underwent jaw bone defect surgery and tail vein injection every 7 days (the control group was injected with phosphoric buffer saline, LT-EV group was injected with LT-EV), micro-CT was used to evaluate the degree of mouse jaw bone healing 28 days after surgery, HE staining was used to analyze the multi-organ biosafety of LT-EV, and immunofluorescence staining was used to detect the jaw bone expression of osteogenic marker proteins in the defect area. Human jaw bone mesenchymal stem cells (hJBMSC) induced by osteogenic differentiation were treated with LT-EV (obtained from orthognathic surgery patients provided by the Department of Traumatology and Orthognathic Surgery of the Third Affiliated Hospital of Air Force Medical University resected normal jaw bone fragments), and the difference in osteogenic differentiation ability between the hJBMSC group and the control group (phosphate buffer saline treatment) was compared, and the in vitro bone differentiation promoting effect of LT-EV was verified through alkaline phosphatase (ALP) staining and real-time quantitative PCR (qRT-PCR). Results: The yield of LT-EV was high, and proteomics and Kyoto Encyclopedia of Genes and Genomes showed that LT-EV contained a series of proteins that regulated cell biological functions. LT-EV injected into the tail vein could reach the mouse jaw bone defect area and promote the regeneration and repair of the jaw bone defect [the bone volume fractions of the LT-EV group and the control group were (36.06±4.20)% and (18.58±5.61)%, respectively; t=4.32, P=0.013], and had good biosafety. LT-EV could promote osteogenic differentiation of hJBMSC in vitro. Compared to the control group, ALP staining and osteogenic gene expression levels were significantly enhanced after osteogenic differentiation of hJBMSC (P<0.05). Conclusions: LT-EV exhibits a high yield, ease of acquisition, high biological safety, and excellent bone-promoting effects. It holds promise as a novel cell-free therapy strategy for regenerating craniofacial bone defects.

[Analysis of the differences in the characteristics of mesenchymal stem cells derived from jaw and long bones based on single-cell RNA-sequencing]

Objective: To study the whole bone marrow cellular composition of jaw and long bones, and further analyze the heterogeneity of mesenchymal stem cells (MSCs) derived from these two tissue, aiming at exploring the differences in functional characteristics of bone MSCs from different lineage sources. Methods: The Seurat package of R language was used to analyze the mandibular and femur whole bone marrow single-cell RNA-sequencing (scRNA-seq) datasets in the literature, and the subpopulations were annotated by reference to the marker genes reported by previous studies. The differentially expressed genes between mandible-derived MSCs (M-MSCs) and femur-derived MSCs (F-MSCs) were calculated, and cell-cell communication analysis between M-MSCs or F-MSCs with other cell populations was performed. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed on up-regulated and down-regulated differentially expressed genes of M-MSCs, and Gene Set Enrichment Analysis (GSEA) was performed on M-MSCs or F-MSCs. Results: cRNA-seq analysis showed that the mandible and femur had the same bone marrow cell composition, but there were differences in the proportion of specific cell populations. Also, there were significantly differentially expressed genes between M-MSCs and F-MSCs. In addition, cell-cell communication analysis revealed differences in numbers of ligand-receptor pairs between M-MSCs or F-MSCs with other cell populations. Furthermore, GO, KEGG and GSEA analysis showed that M-MSCs had higher extracellular matrix production potential than F-MSCs, but had lower ability to regulate other cells in the bone marrow, especially immune cells. Conclusions: M-MSCs and F-MSCs showed distinct differences in the gene expression pattern and up-regulated signaling pathways, which may be closely related to the developmental sources and functional characteristics of jaw and long bones.

Autonomic neural regulation in mediating the brain-bone axis: mechanisms and implications for regeneration under psychological stress

Efficient regeneration of bone defects caused by disease or significant trauma is a major challenge in current medicine, which is particularly difficult yet significant under the emerging psychological stress in the modern society. Notably, the brain-bone axis has been proposed as a prominent new concept in recent years, among which autonomic nerves act as an essential and emerging skeletal pathophysiological factor related to psychological stress. Studies have established that sympathetic cues lead to impairment of bone homeostasis mainly through acting on mesenchymal stem cells (MSCs) and their derivatives with also affecting the hematopoietic stem cell (HSC)-lineage osteoclasts, and the autonomic neural regulation of stem cell lineages in bone is increasingly recognized to contribute to the bone degenerative disease, osteoporosis. This review summarizes the distribution characteristics of autonomic nerves in bone, introduces the regulatory effects and mechanisms of autonomic nerves on MSC and HSC lineages, and expounds the crucial role of autonomic neural regulation on bone physiology and pathology, which acts as a bridge between the brain and the bone. With the translational perspective, we further highlight the autonomic neural basis of psychological stress-induced bone loss and a series of pharmaceutical therapeutic strategies and implications toward bone regeneration. The summary of research progress in this field will add knowledge to the current landscape of inter-organ crosstalk and provide a medicinal basis for the achievement of clinical bone regeneration in the future.

Effect of bimatoprost sustained-release intracameral implant on intraocular pressure and medication burden in patients with prior glaucoma surgery

The present retrospective study evaluated intraocular pressure (IOP) and medication burden after bimatoprost sustained-release (bimatoprost SR, Durysta, Allergan) implantation in patients with glaucoma. A secondary objective was to examine an effect of bimatoprost SR in a subset of patients with prior minimally invasive and incisional glaucoma surgery. A retrospective chart review of 122 eyes that received bimatoprost SR by 6 glaucoma specialists at Wills Eye Hospital between March 2020 and September 2021 was performed. One hundred and eighteen eyes from 84 patients had a reduction in IOP (18.5±5.7mmHg vs. 16.0±5.4mmHg, P<0.01) and required fewer glaucoma medications (2.1±1.4 vs. 1.2±1.2, P<0.01) after bimatoprost SR implantation. In 41 eyes from 31 patients who previously underwent glaucoma surgery (including iStent, goniotomy, trabeculectomy, Xen Gel Stent, or tube shunt surgery), medication burden was decreased after bimatoprost SR implantation (1.9±1.3 vs. 1.0±1.0, P<0.001). These data suggest that bimatoprost SR is an efficacious treatment modality for glaucoma, even in post-surgical patients.

[Prevalence and risk factors of diabetic retinopathy in hospital patients]

Objective: To analyze the prevalence and risk factors of diabetic retinopathy (DR) in ophthalmic patients. Methods: A cross-sectional study was performed. Diabetic patients who were admitted to Department of Ophthalmology, Traditional Chinese Medicine Hospital of Muping between October 2012 and June 2013 were included. General information and medical history were obtained from each subject by questionaires. Laboratory and detailed ophthalmic examinations were performed during the study. DR was diagnosed and graded by mydriatic fundus photography. Prevalence of DR was calculated and logistic regression was used to analyze the relationship between DR and various factors. Results: A total of 676 diabetic patients were included, and 455 of them presented with DR at a morbidity rate of 67.31%. Among DR patients, the number of mild, moderate, severe non-proliferative diabetic retinopathy (NPDR) patients and proliferative diabetic retinopathy (PDR) patients were 211 (46.37%), 167 (36.70%), 57 (12.53%) and 20 (4.40%), respectively. There was no significant difference in the prevalence of DR among different age groups (χ(2)=6.527, P=0.089). However, there was a significant difference between different disease duration groups (χ(2)=39.401, P<0.001), as well as between insulin therapy group and non-insulin therapy group (χ(2)=7.378, P=0.007). The multivariate logistic regression analysis demonstrated the independent risk factors for DR occurrence were hemoglobin A1c (HbA1c) (OR=1.131, 95%CI: 1.022-1.252, P=0.011) and duration of diabetes (OR=1.077, 95%CI: 1.046-1.108, P<0.001). Conclusions: The prevalence of DR in ophthalmic patients was associated with duration of diabetes, HbA1c, obesity, smoke, nephropaty and insulin therapy. Increased HbA1c level and longer duration of diabetes were independent risk factors for DR in diabetic patients.

Microenvironmental Views on Mesenchymal Stem Cell Differentiation in Aging

Aging is characterized by common environmental changes, such as hormonal, immunologic, and metabolic disorders. These pathologic factors impair the capability of mesenchymal stem cells (MSCs) to generate and maintain functionalized tissue components, contributing to age-related tissue degeneration (e.g., osteoporosis). However, in organismal aging, whether the microenvironmental signals induce common or differential MSC compromise and how they interact at the molecular level in mediating the functional decline of MSCs are not fully understood. In this review, we discuss the respective contribution of microenvironmental pathologic factors to age-related MSC dysfunction-particularly, the shifted differentiation from osteoblasts to adipocytes of bone marrow-derived MSCs. The authors summarize recent works regarding mechanisms underlying MSC-biased differentiation under altered microenvironments, which involve the activation of key signaling pathways, intracellular oxidative stress, and posttranscriptional regulations. In addition, we compare the differential influences of systemic and local microenvironments on MSC differentiation based on our findings. The authors also propose strategies to rescue differentiation disorders of MSCs in aging via modulating microenvironments, by using signaling modulators, anti-inflammatory agents, antioxidants, and metabolic regulators and by promoting mobilization of systemic MSCs to local injury sites. The authors hope that these insights contribute to MSC-based organismal aging research and treatments.

Selecting the optimum conditions for two-dimensional difference gel electrophoresis of proteins expressed in Populus euphratica

We selected the optimum conditions for two-dimensional difference gel electrophoresis (2D-DIGE) of proteins expressed in the heteromorphic leaves of Populus euphratica Oliv. by adjusting the isoelectric focusing, the loading quantity, the concentration of the electrophoretic gel, and other parameters. The results of our study showed that protein separation was improved with many clear protein spots observed, and the differentiations were obvious. The findings of this study will be useful for future studies of protein expression in the heteromorphic leaves of P. euphratica.

Origin of quantum ring formation during droplet epitaxy

Droplet epitaxy of GaAs is studied in real time using in situ surface electron microscopy. The resulting movies motivate a theoretical model for quantum ring formation which can explain the origin of nanoscale features such as double rings observed under a variety of experimental conditions. Inner rings correspond to GaAs deposition at the droplet edge, while outer rings result from the reaction of Ga and As atoms diffusing along the surface. The observed variety of morphologies primarily reflects relative changes in the outer rings with temperature and As flux.

Abstract P3-08-06: Triple Negative Breast Cancer and BRCA Status: Implications for Genetic Counseling

BACKGROUND: Controversy exists whether women newly diagnosed with triple negative breast cancer (TNBC) should be referred to genetic counseling as they may be more likely to be BRCA carriers. However, prior studies included small numbers of carriers and their results have had limited influence on practice guidelines. The objective of this study was to determine the association of breast cancer molecular subtype and BRCA status in a large group of medically insured women.

METHODS: We examined a cohort of 2,105 women with breast cancer history tested for BRCA mutations in a large California health plan from 1997–2011. BRCA test results were recorded in the health plan's clinical genetics registry. Of the 2,105 breast cancer patients, 249 were BRCA mutation carriers (143 BRCA1 carriers, and 106 BRCA2 carriers). We conducted data linkages of all patients with the health plan's NCI-SEER affiliated tumor registry and identified ER, PR, and HER2. HER2 status was also captured from pathology reports using natural language processing. ER, PR, and HER2 status were assessed by immunohistochemical or FISH techniques. Patients were classified into four main biologic subtypes: triple negative (ER−/PR−/HER2−); luminal A (ER+ and/or PR+/HER2−); luminal B (ER+ and/or PR+/HER2+); and HER2-enriched (HER2+/ER−). We examined the association between molecular subtypes (collapsed into TNBC vs. non TNBC categories) and BRCA1/2 mutation status using contingency table analyses. P-values (two-sided) were estimated using chi-square analysis. Multivariable logistic regression was used to estimated adjusted odds ratios (OR) and 95% confidence intervals.

RESULTS: TNBC subtype was strongly associated with BRCA status (P &lt; 0.0001). Women with TNBC tumors were five-fold more likely to be BRCA carriers than women who had non-TNBC breast tumors (OR = 5.6, 95% CI: 4.1–7.5). Specifically, the association of TNBC with BRCA1 was more robust (OR = 12.2, 95% CI: 8.3–17.9). Adjusting for age and stage of breast cancer diagnosis and race/ethnicity did not materially modify the association between TNBC and BRCA1 status. TNBC was not associated with BRCA2 status (OR = 1.6, 95% CI: 0.9–2.7).

Circulating thrombomodulin and vascular cell adhesion molecule-1 and renal vascular lesion in patients with lupus nephritis

Currently, the detection of renal vascular lesions (VLS) in lupus nephritis (LN) mainly depends on biopsy examination, and lack surrogate biomarkers for clinical dynamic evaluation. The aim of the present study is to explore the correlation between circulatory endothelial damage biomarkers and VLS. Soluble E-selectin, thrombomodulin (TM) and vascular cell adhesion molecule-1 (VCAM-1) were measured by ELISA. TM and VCAM-1 levels both were significantly elevated in LN with VLS than in LN without VLS (P < 0.01). However, the serum E-selectin was not significantly changed in LN patients with and without VLS. A positive correlation was found between TM and serum creatinine (r = 0.617, P < 0.05) in patients with vascular lesions. In order to further analyse the relationship between TM level and severity degree of vascular lesions in LN patients, we subdivided the patients with vascular lesions into two groups: with thrombotic microangiopathy (TMA) and without TMA. TM level of the patients with TMA is significantly higher than those without TMA (P < 0.01). In conclusion, combined with renal pathological examination, monitoring the circulatory levels of TM and VCAM-1, can provide circulating biomarkers of VLS in LN patients.

High efficient encapsulation of plasmid DNA in PLGA microparticles by organic phase self-emulsification

To overcome the drawbacks of encapsulating plasmid DNA (pDNA) in poly (D,L-lactic-co-glycolic acid) (PLGA) by water-in-oil-in-water double-emulsion solvent-evaporation method, we have developed a novel procedure for encapsulating pDNA in PLGA microparticles called DNA organic phase self-emulsification (DOPSM). This method was based on both the extraction plasmid DNA from aqueous phase into organic phase and the spontaneous emulsification DNA in organic phase by solvent diffusion method. The efficiency of extraction plasmid DNA into organic phase is 99% and the concentration of pDNA in organic phase is up to 2.4 mg/ml. The efficiency of microencapsulation of plasmid DNA in PLGA is up to 76% and can be enhanced by lowering the pH of aqueous solution of emulsion. The microparticles size of PLGA of pDNA is in a narrow range of 1-2 microm. This procedure does not involve the high mechanical energy to emulsify which may damage the integrity of pDNA. This method can be applied to encapsulate the pDNA into microparticles of other biocompatible polymers with high efficiency.

[The application of adaptive line enhancement filter in extracting cutaneous electrogastrogram]

Based on the principle of adaptive filtering, The higher signal-to-noise ratio of electrogastrogram data can be extracted from abdomen skin with the adaptive line enhancement filter. The design method of feedback factor and filtering coefficient is introduced in this paper. Experimental and practical results show the method is effective.

[Analytic solution and experimental verification of pressure control function of the sealed module of manned space vehicle]

OBJECTIVE

The analytic solution of the overall pressure and oxygen partial pressure in the scaled module of manned space vehicle was deduced, it can be used by ECLSS overall engineering designer to predict the pressure control parameters when space flight or ground test is operating.

METHOD

According to different gas supply situations and the role of pressure control zone prescribed by ECLSS, the flight duration was divided into several segments under the role of pressure control zone, and the differential equations were solved.

RESULT

The analytic solutions of the total pressure and partial pressure of oxygen were obtained, and the theoretical curve corresponds well to the test value.

CONCLUSION

The analytic solutions obtained were valid, and satisfied the requirement of engineering accuracy.

Bispectrum analysis of focal ischemic cerebral EEG signal using third-order recursion method

In this paper, a model for Sprague-Dawley (SD) rat focal ischemic cerebral injury is presented. Based on this experimental model, the electroencephalogram (EEG) from the ischemic region and from a normal region are collected during the first 30 min of ischemia. The EEG bispectrum analysis is carefully investigated by using the third-order recursion method. We found that some characteristics of the bispectrum are very sensitive to focal ischemic cerebral injury. The maximum magnitude and the weighted center of EEG bispectrum (WCOB) change according to the extent and the place of the injury region. The bispectrum analysis results have been verified by the heat shock protein (HSP) test. The study indicates that the EEG bispectrum analysis may be useful to distinguish the ischemic region from the normal one and to estimate the ischemic extent.

[Exercise ECG test as a method for non-invasive detection of myocardial ischemia]

OBJECTIVE

To improve the exercise ECG analysis for non-invasively detection of myocardial ischemia.

METHOD

The newly developed measuring system of exercise ECG defines ST segment area and STA/HR slope as the new characteristic parameters, thus can sensitively detect myocardial ischemia. Some methods were proposed to reduce noise and artifacts for effective sampling of exercise ECG.

RESULT

14 exercise ECG records were sampled and analyzed in clinical exercise test. It was found that the new parameters are very effective and sensitive to myocardial ischemia. The results show that the method is reliable and stable.

CONCLUSION

The method improves one of the evaluating indexes of exercise ECG analysis. It is quite promising for clinical application in future.

[Adult diarrhea rotavirus in Jilin, China]

In May 1986, an outbreak of epidemic acute diarrhea occurred in one city and three counties in Yanbian area. The diarrheal cases were seen in all age groups, the majority of the cases were seen in adult age group. No bacterial pathogens were isolated in 22 fecal samples examined, however rotavirus like particles of 52-68 nm in diameter were found in 50% (11/22) of fecal samples by the immunoelectron microscopy using convalescent sera. Examination by the adult diarrhea rotavirus (ADRV) ELISA kit showed positive reaction in 86% (6/7) of fecal extracts, however in all 22 fecal extracts examination using ELISA kit for detection of group A rotavirus showed negative reaction. The PAGE patterns of viral RNAs similar to those of ADRV were seen in 13 out of 22 fecal extracts. The detection rate by PAGE analysis was 59%. Based on the above data, the etiological agent of the epidemic acute diarrhea, which occurred in Yanbian area, was identified to be ADRV.

Isolation and purification of a small peptide with activity of increasing E-receptor expression from calf thymus

A small peptide of molecular mass lower than 1,000 daltons was isolated and purified from a crude extract of calf thymus. It has been demonstrated to have the activity of increasing E-rosette formation and E-receptor expression of human and porcine T-lymphocytes with three different in vitro assays. Amino acid composition analysis showed that this peptide consists of glutamic acid, aspartic acid and glycine residues at a molecular ratio of 3:3:2. A hypothesis of a multi-factoral and multi-staged mechanism of regulation of thymocyte differentiation and maturation in the thymus is proposed.

Inhibition of the production of a soluble helper mediator by cyclosporin A results in the failure to generate alloreactive cytolytic cells in mixed-lymphocyte culture

The mechanism of action of cyclosporin A (CsA) in inhibiting the induction of alloreactive cytolytic T lymphocytes (CTL) in mixed-lymphocyte culture (MLC) was investigated. CsA at concentrations of 10(-3) to 10(-1) micrograms/ml completely prevented the generation of CTL. However, the addition of culture supernatants from mitogen-activated lymphocytes to MLC not only significantly reversed the suppressive effect of CsA but also fully restored the reactivity of lymphocytes already treated with CsA. By measuring the presence of a soluble helper mediator (SHF) in MLC supernatants, we found that CsA-treated lymphocytes produced no SHF, possibly interleukin 2 (IL-2). The effect of CsA on receptors for IL-2 was subsequently studied and it was found that the binding capacity of 125I-labeled IL-2 to lymphocytes was not altered by the presence of CsA. These findings suggest that the prevention of helper cells from producing SHF, rather than the inhibition of the response of effector cells to SHF, is a possible explanation for the immunosuppression mediated by CsA.