The development of efficient molecular imaging probes with high specificity, high sensitivity, and low toxicity is the core in promoting the development of cancer molecular imaging technology. Natural expressed purified protein-based nanocage with self-assembling ability to form intrinsically cavity structure has been widely used to prepare various molecular imaging probes of cancer for its ideal physical properties, excellent biological compatibility, exceptional biodegradability as well as diverse engineering strategies. This paper focuses on the research progress of natural protein-based nanocage from the following aspects: various types of protein-based nanocages of different origins and compositions, cargos loading mechanisms, functionalization strategies, and their recent advances in cancer molecular imaging.

Objective To detect the mutations of the marOR gene and study the relations with the expressing level of the acrAB-tolC efflux pump in Shigella. Methods marOR genes were amplified by PCR for 100 clinical isolates and 5 reference strains of Shigella. The PCR products were digested by restriction endonuclease Taq Ⅰ , then analyzed by single strand conformation polymorphism(SSCP). The marOR genes of the mutated strains and sensitive strain were sequenced and the expressing leveLs of acrA, acrB and talC were determined by RT-PCR. Susceptibility tests of tetracycline (TE), chloramphenicol (C), ampicillin (Am) , gentamycin (GM), norfloxacin (NOR) and selectrin (SMZ-TMP) were performed in sequenced strains. Results marOR genes were found in all strains detected. SSCP analysis found the rate of mutations in marOR genes was 23%. Among 11 marOR gene-mutated strains which were sequenced, there were 9 strains having a four-base absence and three single-base mutations in different loci. The expressing levels of the acrAB-tolC efflux pump in the 11 strains were higher than those in sensitive strains and reference strain. Furthermore the 11 strains were multi-drug resistance. Conclusion The mutation rate of marOR gene in Shigella was high and the acrAB-tolC efflux pump genes were over-expressive in marOR gene-mutated strains which were multi-antibiotic resistance in the study.

Objective To detect the influence of marOR mutations on antibiotic resistance in Shigella spp. Methods The marOR gene with four-base deletion was amplified by overlap PCR, then inserted in a T-vector and transformed into DH5α. The clone of marOR gene with four-base deletion and three point mutations was prepared from the strain having these mutations. Electrophoresis and sequencing were preformed to certify the correction of the cloned genes. Drug susceptibility tests were preformed for the strains harbouring the different clones [DH5α, DH5α (T), DH5α (marOR), DH5α (marOR-CATT), DH5α(marOR-CATT + 3m)]. Results Compared with the control strain (DH5α-T), the antibiotic resistances of marOR with four-base deletion [DH5α (marOR-CATT)] were higher to streptomycin, tobramycin, cefazolin and cefalexin, and the antibiotic resistances of marOR with four-base deletion and three point mutations [DH5α (marOR-CATT + 3m)] were higher to streptomycin and to tetracycline. The antibiotic resistances of DH5α (marOR-CATT) and DH5α (marOR-CATT +3m) to streptomycin, tetracycline, chloramphenicol, cefazolin, levofloxacin, ciprofloxacin and norfloxacin were higher than DH5α (marOR). The diameters of the antibiotics except the trimethoprim between DH5α (marOR-CATT) and DH5α (marORCATT +3m) had not significant disparity. Conclusion The four-base deletion in 1376-1379 sites of the marOR gene increased the resistance of Shigella spp to some antibiotics. The point mutations in 1411, 1417,1435 sites of the marOR gene have little influence on the antibiotic resistance of Shigella spp.

With the discovery of exosomes,new pathways of intercellular information and material exchange mediated by exosomes are attracting more and more attention from researchers. The process of exo-some production overlaps with many viral assembly and outflow pathways,suggesting that exosomes may be related to viral infections. In vitro experiments also show that exosomes play a very important role in viral in-fections. On one hand,exosomes can transfer viral nucleic acids and proteins,and may change microenviron-ment to promote the spread of infection. On the other hand,exosomes can induce immune responses by activa-ting antiviral pathways or transferring antiviral molecules. Do they promote or suppress the spread of infec-tion? What are the factors that affect their functions? In this paper,we review the role of exosomes in viral in-fection in order to provide a reference for better understanding the process of viral infection and immune re-sponses,and to provide a new train of thoughts for the prevention,diagnosis and treatment of viral diseases.

Objective:To investigate the correlations between cerebral β-amyloid (Aβ) deposition assessed by 18F-florbetapir (AV45) PET imaging and clinical cognitive symptoms in patients with subtle cognitive decline (SCD) and mild cognitive impairment (MCI). Methods:Data of twenty-four patients (11 males, 13 females, age: (63.2±7.6) years) diagnosed as SCD ( n=15) or MCI ( n=9) from December 2018 to March 2019 in Shanghai Jiao Tong University Affiliated Sixth People′s Hospital were collected prospectively. All patients underwent 18F-AV45 PET imaging, brain MRI T 1 scan and Mini-Mental State Examination (MMSE) within two weeks. 18F-AV45 PET images were analyzed visually (positive, mild positive, negative). After being pretreated according to the MRI, 18F-AV45 PET images were analyzed semi-quantitatively by calculating the standardized uptake value ratio (SUVR) of Aβ deposition in 8 regions of interest (ROIs; frontal lobe, lateral parietal lobe, lateral temporal lobe, medial temporal lobe, occipital lobe, basal ganglia, posterior cingulate and precuneus), with cerebellar gray matter as the reference. Partial correlation coefficients between regional SUVRs and MMSE score were calculated. Results:18F-AV45 PET imaging showed that 16 patients with positive results and 8 patients with mild positive results. MMSE score of 24 patients was 28.2±2.0, and the SUVR was 0.93-1.87. Correlation analysis revealed that Aβ deposition in frontal cortex ( r=-0.432), posterior cingulate lobe ( r=-0.434) and precuneus ( r=-0.418) was negatively correlated with MMSE score (all P<0.05); and no significant correlations between SUVR and MMSE in other brain regions were found ( r values: from -0.412 to -0.110, all P>0.05). Conclusion:18F-AV45 PET imaging can noninvasively detect brain Aβ deposition in patients, and can effectively reflect the clinical cognitive status of patients with SCD and MCI to a certain extent.

Objective:To collect data on urinary flow rate in the elderly female population across the country and to analyze the range of reference values.Methods:This study enrolled 333 subjects from July 2020 to June 2022.The study implementation process was divided into two steps.In the first step, subjects completed an electronic questionnaire, which included basic information about the subject, a short form for urinary incontinence, and a scoring form for the symptoms of overactive bladder syndrome.In the second step, the staff introduced the use of a mobile uroflowmetric device and distributed the instrument and materials.Uroflow rate data were automatically uploaded to a cloud database via the mobile phone.Subsequently, two or more physicians specializing in urinary control performed Uroflow rate-qualifying screenings and conducted statistical analyses.Results:A total of 333 subjects were enrolled in the study, and the researchers collected 1375 qualified urine flow rate records using a mobile urine flow rate instrument.The age of the subjects ranged from 60 to 84 years, with a mean age of 69 years.The reference ranges for urinary flow rate were found to be 24.8-26.2 s, with a mean urinary flow rate of 12.2-12.9 ml/s, a maximum urinary flow rate of 22.2-23.4 ml/s, and a time to peak of 8.5-9.7 s. The study observed a tendency for both maximal and mean urinary flow rates to decrease in older women as their age increased(Pearson correlation coefficient: -0.1, P<0.001). Conclusions:The uroflow rate of older women decreases with aging.Specifically, the average uroflow rate of women over 80 years old is lower than that of other age groups.This study aims to establish normal uroflow parameters for uroflowmetry in healthy older women in China.

Background The human body is usually exposed to a variety of heavy metals at the same time, and different types and concentrations of heavy metals may have complex interactions during their absorption and metabolism in the human body. Seminal fructose is an important energy source for sperm movement. A large number of studies have shown that metal exposure may impair semen quality, and seminal fructose is an important factor affecting male reproduction, so it is necessary to investigate the relationship between mixed heavy metal exposure and seminal fructose to explore the mechanism of semen quality damage caused by metal exposure. Objective To understand the status of common heavy metal exposure in men of childbearing age in Puyang City, Henan Province, and to study the relationship between mixed exposure to heavy metals and seminal fructose, as well as potential interactions among heavy metals. Methods Volunteers were recruited from the Puyang Maternal and Child Health Hospital Reproductive Center for a cross-sectional survey on general demographic characteristics, smoking, alcohol consumption, and other information. Semen samples were collected to detect 12 metals such as vanadium (V), manganese (Mn), cobalt (Co), nickel (Ni), zinc (Zn), selenium (Se), silver (Ag), cadmium (Cd), barium (Ba), thallium (Tl), iron (Fe), and lead (Pb) in seminal plasma and seminal fructose. After correcting for selected confounding factors, a Bayesian kernel machine regression (BKMR) model was used to evaluate the impact of seminal plasma heavy metal mixed exposure and its interactions on seminal fructose. Results A total of 825 adult males were enrolled. The concentrations in M (P₂₅, P₇₅) of V, Mn, Co, Ni, Zn, Se, Ag, Cd, Ba, Tl, Fe, and Pb in seminal plasma were 0.39 (0.28, 0.54), 12.31 (8.92, 17.52), 0.26 (0.18, 0.38), 5.15 (3.32, 8.64), 182159.80 (121847.80, 199144.50), 13.61 (10.55, 17.68), 0.03 (0.02, 0.04), 0.34 (0.27, 0.46), 8.64 (5.94, 13.43), 0.06 (0.05, 0.08), 168.74 (114.17, 259.45), and 1.69 (1.15, 2.36) μg·L⁻¹ respectively. The Spearman correlation results indicated that there was a negative correlation between V, Mn, Co, Zn, Se, Ba, Tl, or Fe in seminal plasma and seminal fructose (P<0.05), and the values of r (95%CI) were −0.044 (−0.087, −0.001), −0.129 (−0.171, −0.087), −0.055 (−0.099, −0.012), −0.099 (−0.143, −0.056), −0.053 (−0.097, −0.010), −0.068 (−0.111, −0.025), −0.095 (−0.138, −0.052), and −0.082 (−0.125, −0.039), respectively. The results of multiple linear regression indicated that there was a negative correlation between the exposure level of Cd, Mn, Zn, Ag, Ba, Tl, or Fe in seminal plasma and seminal fructose (P<0.05), the values of associated β (95%CI) were −0.551 (−0.956, −0.147), −0.315 (−0.419, −0.212), −0.187 (−0.272, −0.103), −0.161 (−0.301, −0.021), −0.188 (−0.314, −0.062), −1.159 (−2.170, −0.147), and −0.153 (−0.230, −0.076), respectively. The BKMR model analysis showed that seminal fructose level decreased with the increase of plasma metal mixed exposure concentration. Compared with all metal exposure at P₅₀, the seminal fructose level decreased by 0.2374 units when all metal exposure was at P₇₅. Seminal plasma Zn [posterior inclusion probabilities (PIPs)=1.0000] had the strongest effect on seminal fructose, followed by Mn (PIPs=0.5872), Se (PIPs=0.5656), and Ba (PIPs=0.5398). The univariate exposure-response curve showed a negative approximate linear correlations between Ba or Mn and seminal fructose, a positive linear correlation between Se and seminal fructose, and an approximate inverted U-shaped association between Zn and seminal fructose. No significant interaction between studied metals was found. Conclusion Mixed metal exposure may lead to decrease of seminal fructose, in which Zn, Mn, Se, and Ba may play an important role. Mn and Zn exposure may reduce the level of seminal fructose, Se may increase the level of seminal fructose, and there may be a threshold effect between Zn exposure and seminal fructose level. No interaction between different metals on seminal fructose is found.