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Immune surveillance and chemotherapy sensitivity play critical functions in the tumorigenesis of breast cancer (BC). Emerging findings have indicated that circular RNA (circRNA) and N6-methyladenosine (m6A) both participate in the BC tumorigenesis. Here, present study aimed to investigate the roles of m6A-modified circATAD2 on BC and explore better understanding for BC precision therapeutic. Results reported that m6A-modifid circRNA (m6A-circRNA) microarray revealed the m6A-circRNA landscape in BC. M6A-modifid circATAD2 upregulated in BC samples and was closely correlated to poor prognosis. Functionally, circATAD2 promoted the immune evasion of BC cells and reduced the CD8+ T cells’ killing effect. Mechanistically, MeRIP-seq unveiled the m6A modification in the 3’-UTR of PD-L1 mRNA, which was bound by circATAD2 and recognized by m6A reader IGF2BP3 to enhance PD-L1 mRNA stability and expression. In summary, these findings revealed the circATAD2/m6A/IGF2BP3/PD-L1 axis in BC immune surveillance, suggesting the potential that circATAD2 as a potential target for PD-L1-mediated BC. [ABSTRACT FROM AUTHOR]

Ubiquitin-proteasome system dysfunction triggers α-synuclein aggregation, a hallmark of neurodegenerative diseases, such as Parkinson's disease (PD). However, the crosstalk between deubiquitinating enzyme (DUBs) and α-synuclein pathology remains unclear. In this study, we observed a decrease in the level of ubiquitin-specific protease 14 (USP14), a DUB, in the cerebrospinal fluid (CSF) of PD patients, particularly females. Moreover, CSF USP14 exhibited a dual correlation with α-synuclein in male and female PD patients. To investigate the impact of USP14 deficiency, we crossed USP14 heterozygous mouse (USP14+/−) with transgenic A53T PD mouse (A53T-Tg) or injected adeno-associated virus (AAV) carrying human α-synuclein (AAV-hα-Syn) in USP14+/− mice. We found that Usp14 deficiency improved the behavioral abnormities and pathological α-synuclein deposition in female A53T-Tg or AAV-hα-Syn mice. Additionally, Usp14 inactivation attenuates the pro-inflammatory response in female AAV-hα-Syn mice, whereas Usp14 inactivation demonstrated opposite effects in male AAV-hα-Syn mice. Mechanistically, the heterodimeric protein S100A8/A9 may be the downstream target of Usp14 deficiency in female mouse models of α-synucleinopathies. Furthermore, upregulated S100A8/A9 was responsible for α-synuclein degradation by autophagy and the suppression of the pro-inflammatory response in microglia after Usp14 knockdown. Consequently, our study suggests that USP14 could serve as a novel therapeutic target in PD. [ABSTRACT FROM AUTHOR]

Purpose: There are undetectable levels of fat in fat-poor angiomyolipoma. Thus, it is often misdiagnosed as renal cell carcinoma. We aimed to develop and evaluate a multichannel deep learning model for differentiating fat-poor angiomyolipoma (fp-AML) from renal cell carcinoma (RCC). Methods: This two-center retrospective study included 320 patients from the First Affiliated Hospital of Sun Yat-Sen University (FAHSYSU) and 132 patients from the Sun Yat-Sen University Cancer Center (SYSUCC). Data from patients at FAHSYSU were divided into a development dataset (n = 267) and a hold-out dataset (n = 53). The development dataset was used to obtain the optimal combination of CT modality and input channel. The hold-out dataset and SYSUCC dataset were used for independent internal and external validation, respectively. Results: In the development phase, models trained on unenhanced CT images performed significantly better than those trained on enhanced CT images based on the fivefold cross-validation. The best patient-level performance, with an average area under the receiver operating characteristic curve (AUC) of 0.951 ± 0.026 (mean ± SD), was achieved using the "unenhanced CT and 7-channel" model, which was finally selected as the optimal model. In the independent internal and external validation, AUCs of 0.966 (95% CI 0.919–1.000) and 0.898 (95% CI 0.824–0.972), respectively, were obtained using the optimal model. In addition, the performance of this model was better on large tumors (≥ 40 mm) in both internal and external validation. Conclusion: The promising results suggest that our multichannel deep learning classifier based on unenhanced whole-tumor CT images is a highly useful tool for differentiating fp-AML from RCC. [ABSTRACT FROM AUTHOR]

Despite the fact that there are not a few relative studies, the effects of geometrical confinement on droplets' generation at micro-T-junctions are not explicitly addressed. A three-dimensional volume of fluid (VOF) CFD model is developed here to study this classic microfluidics problem. The micro-T-junctions are designed with arms of a same hydraulic diameter but different width-to-depth ratios (χ = 1/10–10), covering both deep-style ( χ < 1) and flat-style T-junctions ( χ > 1) . It is found that the width-to-depth ratio (confinement style) shows complex effects on the dynamics of droplets' generation. At χ ≤ 1 / 10 , droplets are failed to be generated at the T-junctions. Compared to the normal T-junctions ( χ > 1 ), the deep-style T-junctions ( 1 / 6 < χ < 1) show much higher generation frequency of droplets at Ca c > 0.06 and the volume of generated droplets scales with Ca c - 1 instead of typical Ca c - 0.33 . The comparative study of two paired T-junctions with reciprocal width-to-depth ratio (e.g., a deep-style T-junction, χ = 1/3 and a flat-style T-junction, χ = 3) explicitly illustrates that the geometrical confinement stabilizes the generation dynamics of droplets at T-junctions. The mechanism for the stabilization effect is discussed. It provides some new insights in terms of designing devices of droplets' generation. [ABSTRACT FROM AUTHOR]

Oral squamous cell carcinoma (OSCC) is one of the most common malignant tumors of the head and neck with poor prognosis. This study aimed to explore the role of lnc-METRNL-1 in occurrence and prognosis of OSCC patients. Expression of lnc-METRNL-1 was compared between OSCC samples and paracancerous samples from The Cancer Genome Atlas (TCGA) database. Additionally, the lnc-METRNL-1 expression in cell lines was detected by using qRT-PCR. The overall survival (OS) was estimated based on the Kaplan–Meier and the immune cell infiltration was evaluated using CIBERSORT. Significantly enriched biological pathways were identified by Gene-set enrichment analysis (GSEA). Differential expression analysis was done in edgeR package. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways of differential expression genes were conducted using DAVID version 6.8. The lnc-METRNL-1 expression in OSCC was significantly lower than that in paracancerous samples, and patients with low lnc-METRNL-1 expression had poorer OS. Additionally, lnc-METRNL-1 was significantly down-regulated in OSCC cell lines compared with normal cell line. High expression of lnc-METRNL-1 was closely associated with the activation of several tumor metabolic and metabolism-related pathways. Besides, aberrant lnc-METRNL-1 expression was found to be related to the differential infiltration of immune cells in tumor tissue, such as regulatory T cells, and Macrophages. Low lnc-METRNL-1 expression was probably a poor prognostic biomarker for OSCC patients. Moreover, the potential role of lnc-METRNL-1 in the onset of OSCC was partly revealed. [ABSTRACT FROM AUTHOR]

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) had become a global concern because of its unexpectedly high pathogenicity and transmissibility. SARS-CoV-2 variants that reduce the immune protection elicited from previous vaccination or natural infection raise challenges in controlling the spread of the pandemic. The development of universal vaccines against these variants seems to be a practical solution to alleviate the physical and economic effects caused by this disease, but it is hard to achieve. In this review, we describe the high mutation rate of RNA viruses and dynamic molecular structures of SARS-CoV-2 variants in several major neutralizing epitopes, trying to answer the question of why universal vaccines are difficult to design. Understanding the biological basis of immune evasion is crucial for combating these obstacles. We then summarize several advancements worthy of further study, including heterologous prime-boost regimens, construction of chimeric immunogens, design of protein nanoparticle antigens, and utilization of conserved neutralizing epitopes. The fact that some immunogens can induce cross-reactive immune responses against heterologous coronaviruses provides hints for universal vaccine development. We hope this review can provide inspiration to current universal vaccine studies. [ABSTRACT FROM AUTHOR]

Previous studies suggest that the reduction of SMAD3 (mothers against decapentaplegic homolog 3) has a great impact on tumor development, but its exact pathological function remains unclear. In this study, we found that the protein level of SMAD3 was greatly reduced in human-grade IV glioblastoma tissues, in which LAMP2A (lysosome-associated membrane protein type 2A) was significantly up-regulated. LAMP2A is a key rate-limiting protein of chaperone-mediated autophagy (CMA), a lysosome pathway of protein degradation that is activated in glioma. We carefully analyzed the amino-acid sequence of SMAD3 and found that it contained a pentapeptide motif biochemically related to KFERQ, which has been proposed to be a targeting sequence for CMA. In vitro, we confirmed that SMAD3 was degraded in either serum-free or KFERQ motif deleted condition, which was regulated by LAMP2A and interacted with HSC70 (heat shock cognate 71 kDa protein). Using isolated lysosomes, amino-acid residues 75 and 128 of SMAD3 were found to be of importance for this process, which affected the CMA pathway in which SMAD3 was involved. Similarly, down-regulating SMAD3 or up-regulating LAMP2A in cultured glioma cells enhanced their proliferation and invasion. Taken together, these results suggest that excessive activation of CMA regulates glioma cell growth by promoting the degradation of SMAD3. Therefore, targeting the SMAD3–LAMP2A-mediated CMA-lysosome pathway may be a promising approach in anti-cancer therapy. [ABSTRACT FROM AUTHOR]

Hydrogels have been extensively favored as drug and cell carriers for the repair of knee cartilage defects. Recruiting mesenchymal stem cells (MSCs) in situ to the defect region could reduce the risk of contamination during cell delivery, which is a highly promising strategy to enhance cartilage repair. Here, a cell-free cartilage tissue engineering (TE) system was developed by applying an injectable chitosan/silk fibroin hydrogel. The hydrogel system could release first stromal cell-derived factor-1 (SDF-1) and then kartogenin (KGN) in a unique sequential drug release mode, which could spatiotemporally promote the recruitment and chondrogenic differentiation of MSCs. This system showed good performance when formulated with SDF-1 (200 ng/mL) and PLGA microspheres loaded with KGN (10 μΜ). The results showed that the hydrogel had good injectability and a reticular porous structure. The microspheres were distributed uniformly in the hydrogel and permitted the sequential release of SDF-1 and KGN. The results of in vitro experiments showed that the hydrogel system had good cytocompatibility and promoted the migration and differentiation of MSCs into chondrocytes. In vivo experiments on articular cartilage defects in rabbits showed that the cell-free hydrogel system was beneficial for cartilage regeneration. Therefore, the composite hydrogel system shows potential for application in cell-free cartilage TE. Schematic illustration of functional injectable hydrogel system for cartilage regeneration. (1) Preparation of hydrogel with the function for spatiotemporal releasing SDF-1 and KGN; (2) Spatiotemporal regulation of MSCs recruitment and chondrogenic differentiation by hydrogel in vitro; (3) Implantation of hydrogel and cartilage regeneration. [ABSTRACT FROM AUTHOR]

Purpose: We aimed to explore whether complete eradication of tumor burden with stereotactic body radiotherapy (SBRT) would affect the outcomes of oligometastatic renal cell carcinoma (RCC). Materials and methods: Patients diagnosed with extracranial oligometastatic RCC (no more than five metastases) between 2007 and 2019 were reviewed. Those without nephrectomy were excluded. SBRT to all, some and no lesions were defined as complete, incomplete, and no SBRT. Progression-free survival (PFS) and cancer-specific survival (CSS) were analyzed using Kaplan–Meier method, Cox regression model and the Fine and Gray method. Result: A total of 101 patients were included, 51.5% of whom had < 3 metastases. Forty (39.6%) patients received complete SBRT, and 61 (60.4%) received no or incomplete SBRT. The 1-year LC rate was 97.3%. The complete SBRT group had significantly longer PFS (26.0 vs 18.8 months; p = 0.043) and CSS (not reached vs. 55.3 months; p = 0.012) compared with the no or incomplete SBRT group. In multivariate analysis, ECOG 0–1 (HR 0.389, 95% CI 0.167–0.906, p = 0.029) and complete SBRT were prognostic factors for CSS (HR 0.307, 95% CI 0.108–0.876, p = 0.027). Complete SBRT was associated with improved CSS in the subgroups of patients with age < 55 years, ECOG 0–1, clear-cell histology, IMDC intermediate/poor risk, metachronous metastasis, and < 3 lesions. Conclusion: Complete eradication of tumor burden with SBRT was associated with better survival in patients with oligometastatic RCC. The recommendation of SBRT to all lesions should be individualized. [ABSTRACT FROM AUTHOR]

Objective: To access the surgical and oncological outcomes of simultaneous thulium laser enucleation of bladder tumor (ThuLEBT) and thulium laser enucleation of prostate (ThuLEP) in patients with non-muscle invasive bladder tumor (NMIBC) and benign prostatic hyperplasia (BPH). Patients and methods: Between June 2009 and June 2017, 118 men with NMIBC who underwent simultaneous ThuLEBT and ThuLEP and fulfilled the inclusion criteria were matched with 118 patients who received ThuLEBT alone. Clinicopathological parameters, surgical outcome data and oncological outcomes were retrospectively analyzed and compared. Results: The patients who underwent simultaneous ThuLEBT and ThuLEP experienced a longer length of operation time (70.4 vs. 25.5 min; p < 0.001), but there were no statistically significant differences in catheterization period, hospital stay and complication between the two groups. At a mean follow-up of 58.7 and 55.8 months in ThuLEBT/ThuLEP group and ThuLEBT group, no significant differences in overall recurrence rates, progression rates, recurrence in the bladder neck/prostatic fossa and mean elapsed time to recurrence were detected. The 5-year recurrence-free probability was 73.2% for ThuLEBT/ThuLEP and 69.2% for ThuLEBT (p = 0.361). Conclusions: Our results indicate that simultaneous ThuLEBT and ThuLEP can be safely performed without increasing the surgical risk and the risk of tumor recurrence and progression in patients with NMIBC and BPH, and it may be preferred alternative for select patients. [ABSTRACT FROM AUTHOR]

To investigate the effect of hydrogen-rich water on myocardial tissue metabolism in a myocardial ischemia-reperfusion injury (MIRI) rat model. Twelve rats were randomly divided into a hydrogen-rich water group and a control group of size 6 each. After the heart was removed, it was fixed in the Langendorff device, and the heart was perfused with 37 °C perfusion solution pre-balanced with oxygen. The control group was perfused with Kreb's-Ringers (K-R) solution, and the hydrogen-rich water group was perfused with K-R solution + hydrogen-rich water. Liquid Chromatograph Mass Spectrometer (LC-MS) analysis platform was used for metabolomics research. Principle component analysis (PCA), partial least squares discriminant analysis (PLS-DA), orthogonal partial least squares discriminant analysis (OPLS-DA), Variable importance in projection (VIP) value of OPLS-DA model (threshold value ≥1) were employed with independent sample T Test (p < 0.05) to find differentially expressed metabolites, and screen for differential metabolic pathways. VIP (OPLS-DA) analysis was performed with T test, and the metabolites of the control group and the hydrogen-rich water group were significantly different, and the glycerophospholipid metabolism was screened. Seven myocardial ischemia-reperfusion injury (MIRI)-related signaling pathways were identified, including glycerophospholipid metabolism, glycosylphosphatidylinositol (GPI) anchored biosynthesis, and purine metabolism, as well as 10 biomarkers such as phosphatidylcholine, phosphatidylethanolamine and phosphatidylserine. Hydrogen-rich water regulates the metabolic imbalance that could change MIRI myocardial tissue metabolism, and alleviate ischemia-reperfusion injury in isolated hearts of rats through multiple signaling pathways. [ABSTRACT FROM AUTHOR]

Accurate determination of the drug-to-antibody ratio (DAR) of interchain cysteine-linked antibody–drug conjugates (ADCs) is challenging. High-resolution mass spectrometry (HRMS) analysis of the ADCs at the intact or subunit level provides a feasible way to measure the DAR. However, the measured DAR is usually lower than the true DAR because of the variation in ionization efficiency between different DAR species. In this work, we developed a novel standard-free HRMS method involving isotope-labeled payload conjugation, protease digestion, and liquid chromatography–HRMS (LC-HRMS) analysis for accurate determination of the DAR of the interchain cysteine-linked ADCs with cleavable or non-cleavable linkers. Isotope-labeled payload conjugations eliminated the structural and chemical differences between different DAR species and ensured that the drugs or payload-containing peptides could be separated from each other in the mass spectrometer. A papain digestion strategy for ADCs with cleavable linkers showed a DAR of 3.79, with a relative standard deviation (RSD) of 0.48 (n = 3). Similarly, the trypsin and chymotrypsin digestion strategy that is applicable to ADCs with non-cleavable linkers showed a DAR of 3.77 and an RSD of 0.86 (n = 3). The DAR determined by this method was consistent with the DAR of the ADCs that was measured by the UV/Vis method. This method will be very useful to researchers working in the field of ADC discovery and development. [ABSTRACT FROM AUTHOR]

As an organic-inorganic composite material, sticky rice slurry-lime mortar (SLM) is being used more and more as a repair material in the preservation of cultural heritage. Taking advantage of environmental scanning electron microscopy and the digital-image correlation technique, the microdeformation and damage mechanisms of SLM subject to wetting/drying are investigated in this study. Three wetting-drying cycles between 20 and 98 % relative humidity (RH) are carried out with different hydric loading rates (i.e., 10 % RH/min, 40 % RH/min, instantaneous RH change). Micro-observation and full-field strain measurement are performed on a domain of size 400 $$\times $$ 345 $$\upmu $$ m $$^2$$ . The results reveal that SLM subject to wetting-drying exhibits a heterogeneous strain field that correlates well with the heterogeneous microstructure of the SLM. In the first cycle, the global swelling strain is 0.25 % when RH increases from 20 to 98 %; when re-drying back to 20 % RH, we found an irreversible strain 0.04 %. The latter is demonstrated to arise from the propagation of pre-existing microcracks during the drying path. However, in the following two wetting-drying cycles, the microcracks become stable, and the irreversible strain changes slightly. [ABSTRACT FROM AUTHOR]

Purpose: To assess the prognostic value of histological parameters in patients with clinical stage I nonseminomatous germ cell tumors (NSGCTs) undergoing active surveillance post-orchiectomy. Methods: Prognoses and recurrence patterns were investigated in 78 patients with CSI NSGCT who underwent orchiectomy. Immediately following orchiectomy, patients participated in active surveillance between 1999 and 2013 at Sun Yat-sen University Cancer Center, Guangzhou, China. Results: 23.1 % of the 78 investigated patients with CSI NSGCT relapsed, within a median time of 5.6 months It was determined using multivariate analysis that lymph vascular invasion (LVI) (OR 6.521; 95 % CI 1.872-22.721; p = 0.003) and the predominant presence of yolk sac tumor (greater than 50 %) (OR 3.537; 95 % CI 1.076-11.628; p = 0.038) independently correlated with relapse-free survival (RFS). Patients were categorized accordingly into three risk groups: low risk [<50 % presence of yolk sac tumor and LVI (−); n = 41], intermediate risk [50 % or greater presence of yolk sac tumor and LVI (+); n = 29], and high risk [50 % or greater presence of yolk sac tumor and LVI (+); n = 8]. Relapse rates of the low-risk, intermediate-risk, and high-risk groups were 7.3, 31.0, and 75.0 %, respectively. Conclusions: LVI and a predominant presence of yolk sac tumor are crucial risk factors for relapse of CSI NSGCT. For patients without either of these risk factors, active surveillance post-orchiectomy is a safe and effective approach for the initial management of CSI NSGCT. [ABSTRACT FROM AUTHOR]

Purpose: The most appropriate procedure for surgical treatment of severe acromioclavicular (AC) joint dislocation was still not clear. The purpose of this study is to evaluate the outcomes of coracoclavicular (CC) reconstruction with ligament augmentation and reconstruction system (LARS) artificial ligaments for the treatment of acute complete AC joint dislocation. Methods: Twenty-four patients (16 male and 8 female, ages ranged from 21 to 45) with acute complete AC joint dislocations were treated with CC reconstruction using LARS artificial ligaments. All these dislocations were unstable injuries. Clinical evaluation was used by the Constant scores and VAS. The radiographic evaluation consisted of Zanca radiographs for bilateral AC joint and axillary radiographs for the injured shoulder. Results: All patients had follow-up times of 36 months (range 6-60). The Constant scores rose from 62.3 ± 6.9 preoperatively to 94.5 ± 9.3 at final evaluation ( P < 0.05). Preoperative VAS scores were 5.1 ± 1.7, and the VAS scores at the last review were 0.7 ± 1.4 ( P < 0.05). Follow-up radiographs showed anatomical reduction in 20 patients and slight loss of reduction in 4 patients. Calcification of CC ligament in 4 patients, degenerative change around the AC joint in 2 patient and clavicular osteolysis around screws in one patient were found. Conclusions: LARS artificial ligament for reconstruction of CC can provide immediate stability and allow early shoulder mobilization with good functional results and few complications. This procedure was an effective and safe method to treat grade III and more AC joint dislocations. Level of evidence: IV. [ABSTRACT FROM AUTHOR]

Excessive estrogenic influence is known to be associated with initiation/promotion of endometrial cancer (EC). Common variants among genes coding for enzymes in sex steroid biosynthetic pathways may influence the risk of EC. Cytochrome P450c17α (CYP17), a gene that codes for a key enzyme (cytochrome P450c17α) in a rate-limiting step of estrogen biosynthesis has attracted considerable attention as a candidate gene for EC. The relationship between CYP17 and EC has been reported in various ethnic groups; however, these studies have yielded contradictory results. To investigate this inconsistency, we performed a meta-analysis of 13 studies involving a total of 3,258 cases and 4,614 controls for −34T>C (rs743572) polymorphism of the CYP17 gene to evaluate the effect of CYP17 on genetic susceptibility for EC. An overall random effects odds ratio of 0.71 (95 % confidence interval 0.58-0.88, P = 0.001) was found under recessive genetic model. Stratified analysis based on ethnicity, sample size and Hardy-Weinberg equilibrium status was conducted to explore potential heterogeneity. This meta-analysis demonstrated that the C allele of −34T>C in CYP17 is a protective factor associated with decreased EC susceptibility, but these associations vary in different ethnic populations. [ABSTRACT FROM AUTHOR]

Somatic embryogenesis was induced from leaf and stem of chrysanthemum ( cv. Yuukou) using various combinations of plant growth regulators. About 93 and 63 % of somatic embryogenesis were respectively induced from leaf and stem cultured in Murashige and Skoog (MS) medium supplemented with 6-benzyladenine (BA) and a-naphthalene acetic acid (NAA). Somatic embryogenesis was more readily induced from leaf, yielding 100 % regeneration rate in MS medium supplement with 0.6 mg/L BA and 1.8 mg/L NAA. Plants were efficiently regenerated from leaf in medium lacking growth regulators, yielding a regeneration rate of 98 %. Micro-morphology analysis revealed the presence of individual somatic embryo and there is no vascular bundle connection between the new embryo structure and the parental tissue. In this study, an efficient system for plant regeneration via somatic embryogenesis from leaves and stems of chrysanthemum was achieved. The result may facilitate mass production of high-quality chrysanthemum seedings for the commercial market. [ABSTRACT FROM AUTHOR]

Microarray technology has been proved to be greatly helpful for biomedical and biological diagnosis. And the evaluation of its biological applications lies in the detection sensitivity, which requires high intensity and stability of the signal. Recently, several nanomaterials, especially semiconductor nanomaterials, due to their excellent fluorescence properties, have been widely used to construct microarrays for biosensors. Here, we presented an approach for constructing CdSe/ZnS quantum dot (QD) microarray in microfluidic channels on a glass slide by photolithography. The conditions for immobilizing stable and uniform QD microarray on the glass slide were optimized. Several types of QD microarrays with different emission wavelengths and modified groups were constructed using silanization and lithography technology. Based on the fluorescence quenching effect of Cu on QDs, the microfluidic chip with QD microarray was applied for the determination of Cu. 1 nmol/L Cu could be detected by this method. [ABSTRACT FROM AUTHOR]

Tumor markers have been of vital importance in cancer diagnosis, treatment and monitoring. However, the sensitivity of current tumor markers for early diagnosis is low, reducing the clinical usefulness of tumor markers. Quantum dots are new fluorescent nanoparticles with unique photophysical and chemical properties, thus having a great potential impact on the investigation of cancer pathogenesis, early diagnosis, targeted therapy, prognosis and monitoring, when combined with tumor markers. The current research is focused on the detection of specific tumor markers or molecules based on tangible carriers such as cells and tissues. One of the most promising clinical applications would be to explore the potential of this highly sensitive labeling technique for the detecting and imagining tumor markers in serum and other body fluids, where some progresses have already been made recently. How to detect early cancer based solely on invisible carriers would be the next step of quantum dots bio-probes in clinical use, so as to develop a new detection technique with greater sensitivity, specificity, rapidity and availability. [ABSTRACT FROM AUTHOR]

Based on tapping mode AFM imaging, a method was demonstrated to evaluate compression elasticity of single double-stranded DNA (dsDNA) molecules in the force region. With images under ambient conditions, Young's moduli of dsDNA in compression were calculated. Results demonstrated that Young's moduli of dsDNA can be simply deduced according to the proposed model. The method can also be used to evaluate the compression elasticity of similar soft nanomaterials. [ABSTRACT FROM AUTHOR]

The history, characteristic, operation modes and coupling techniques of atomic force microscopy (AFM) are introduced. Then the application in cell biology is reviewed in four aspects: cell immobilization methods, cell imaging, force spectrum study and cell manipulation. And the prospect of AFM application in cell biology is discussed. [ABSTRACT FROM AUTHOR]

Objective: To study the effects of 18β-glycyrrhetinic acid (GA) on proliferation inhibition, apop- totic induction, and the relationship between GA-induced apoptosis and intracellular Ca2+ concentration in human breast carcinoma (MCF-7) cells. Methods: After MCF-7 cells were treated with GA at the concentrations from 50 μmol/L to 250 μmol/L for 24 h, cell viability of proliferation was assessed by MTT assay. After the cells were treated with 100 μmol/L, 150 μmol/L, and 200 μmol/L GA for 24 h, the rates of cell apoptosis were examined by terminal deoxynucleotide transferase mediated dUTP nick-end-labeling method and flow cytometry with Annexin V/propidium iodide fluorescent stain. After the cells treated with 150 μmol/L GA for 24 h, intracellular Ca2+ concentration was measured by Fure-2 fluorescein load method. Results: After the cells were treated with GA at the concentrations from 100 μmol/L to 250 μmol/L, the rates of proliferative inhibition were increased significantly (P<0.05 and P<0.01) in a dose- dependent fashion. IC50 of the proliferation inhibition was 234.33 μmol/L. Treated with 100 μmol/L, 150 μmol/L, and 200 μmol/L, the rates of cell apoptosis were increased significantly (P<0.01). Intracellular Ca2+ concentration after treatment with GA was higher evidently than that of control (P<0.05). Conclusion: 18β-glycyrrhetinic acid has the effects of the proliferation inhibition and the apoptotic induction on MCF-7 cells. The rise of intracellular Ca2+ level may be depended on apoptosis induced by GA in MCF-7 cells. [ABSTRACT FROM AUTHOR]

A kind of PH gradient microfluidic chips through soft-lithography microfabrication for isoelectric focusing (IEF) and high performance liquid chromatography (HPLC) is introduced here. These pH gradient chips have the advantages such as easy fabrication, controllable pH range and precision, isoelectric focusing and separation at the same time, low voltage for isoelectric focusing, and time stable pH gradient. This method has potential application to sample preparation, separation and analysis of microfluidic chips. [ABSTRACT FROM AUTHOR]

Examines the effects of Li+ and PEG on DNA uptake in yeast. Factor affecting the binding of plasmid DNA to cell surfaces; Transformation frequency of intact yeast cells; Identification of the bacterial cell wall.