Axial assembly of AuNR for tumor theranostics via Zn2+-GSH chelation induced degradation of AuNR@ZIF-8 heterostructures

Tumor microenvironment responsive photothermal ablation is a noninvasive and accurately targeted approach for cancer therapy. Herein, an intracellular directional assembly strategy for enhanced photothermal therapy (PTT) was realized by using ZIF-8 encapsulated Au nanorod (AuNR) heterostructure as the precursor of photothermal convertible material. The ZIF-8 shell selectively degraded in tumor cells upon the chelation between GSH and Zn2+, while the as-formed Zn(SG) connected the released AuNR in end-to-end fashion. The coating of ZIF-8 shell significantly improves the stability and targeting of AuNR, and the released Zn2+ shielded the GSH binding site on the lateral side of AuNR, increased the plasmonic coupling efficiency of AuNR assembly geometer. This design enabled atomic-economical, efficient and low-side effect targeted photothermal therapy through the effective integration of heterostructures.

Progress in the Mechanism of the Effect of Fe3O4 Nanomaterials on Ferroptosis in Tumor Cells

Ferroptosis is a new form of iron-dependent programmed cell death discovered in recent years, which is caused by the accumulation of lipid peroxidation (LPO) and reactive oxygen species (ROS). Recent studies have shown that cellular ferroptosis is closely related to tumor progression, and the induction of ferroptosis is a new means to inhibit tumor growth. Biocompatible Fe₃O₄ nanoparticles (Fe₃O₄-NPs), rich in Fe²⁺ and Fe³⁺, act as a supplier of iron ions, which not only promote ROS production but also participate in iron metabolism, thus affecting cellular ferroptosis. In addition, Fe₃O₄-NPs combine with other techniques such as photodynamic therapy (PDT); heat stress and sonodynamic therapy (SDT) can further induce cellular ferroptosis effects, which then enhance the antitumor effects. In this paper, we present the research progress and the mechanism of Fe₃O₄-NPs to induce ferroptosis in tumor cells from the perspective of related genes and chemotherapeutic drugs, as well as PDT, heat stress, and SDT techniques.

Biologic Mechanisms of Macrophage Phenotypes Responding to Infection and the Novel Therapies to Moderate Inflammation

Pro-inflammatory and anti-inflammatory types are the main phenotypes of the macrophage, which are commonly notified as M1 and M2, respectively. The alteration of macrophage phenotypes and the progression of inflammation are intimately associated; both phenotypes usually coexist throughout the whole inflammation stage, involving the transduction of intracellular signals and the secretion of extracellular cytokines. This paper aims to address the interaction of macrophages and surrounding cells and tissues with inflammation-related diseases and clarify the crosstalk of signal pathways relevant to the phenotypic metamorphosis of macrophages. On these bases, some novel therapeutic methods are proposed for regulating inflammation through monitoring the transition of macrophage phenotypes so as to prevent the negative effects of antibiotic drugs utilized in the long term in the clinic. This information will be quite beneficial for the diagnosis and treatment of inflammation-related diseases like pneumonia and other disorders involving macrophages.

Integration and Quantitative Visualization of 3,3',5,5'-Tetramethylbenzidine-Probed Enzyme-Linked Immunosorbent Assay-like Signals in a Photothermal Bar-Chart Microfluidic Chip for Multiplexed Immunosensing

The photothermal effect shows significant promise for various biomedical applications but is rarely exploited for microfluidic lab-on-a-chip bioassays. Herein, a photothermal bar-chart microfluidic immunosensing chip, with the integration of the conventional 3,3',5,5'-tetramethylbenzidine (TMB)-probed enzyme-linked immunosorbent assay (ELISA)-like system, was developed based on exploiting the photothermal pumping technique for visual bar-chart microfluidic immunosensing. Both the sandwich ELISA-like system and the photothermal pumping protocol were integrated into a single photothermal bar-chart chip. On-chip immunocaptured iron oxide nanoparticles catalyzed the oxidation of the chromogenic substrate, TMB, to produce a sensitive photothermal and chromogenic dual-functional probe, oxidized TMB. As the result of heat generation and the subsequent production of elevating vapor pressure in the sealed microfluidic environment, the on-chip near-infrared laser-driven photothermal effect of the probe served as a dose-dependent pumping force to drive the multiplexed quantitative display of the immunosensing signals as visual dye bar charts. Prostate-specific antigen as a model analyte was tested at a limit of detection of 1.9 ng·mL^-1, lower than the clinical diagnostic threshold of prostate cancer. This work presents a new perspective for microfluidic integration and multiplexed quantitative bar-chart visualization of the conventional TMB-probed ELISA signals possibly by means of an affordable handheld laser pointer in a lab-on-a-chip format.

Development of Poloxamer Hydrogels Containing Antibacterial Guanidine-Based Polymers for Healing of Full-Thickness Skin Wound

A series of hydrogels containing guanidine-based polymers using a poloxamer as the matrix were prepared to provide novel wound dressings with antibacterial and repairing-promotion properties for skin wounds. Herein, we developed a series of antibacterial hydrogels, the cationic guanidine-based polymer polyhexamethylene guanidine hydrochloride (PHMG) with poloxamer aqueous solution (12%, w/w) simplified as PHMGP, chitosan (CS)-cross-linked PHMG (referred to as PHMC) with poloxamer aqueous solution simplified as PHMCP, and hyaluronic acid (HA)-modified PHMG (referred to as PHMH) with poloxamer aqueous solution simplified as PHMHP, for enhancing full-thickness skin wound healing. The characterizations, antimicrobial activity, cytotoxicity, and in vivo full-thickness wound-healing capability of these hydrogels were analyzed and evaluated. The results show that though PHMGP possesses great bactericide properties, its cytotoxicity is too strong to support skin regeneration. However, after modified with CS or HA, PHMCP and PHMHP showed good biocompatibility and antimicrobial properties against Gram-positive and Gram-negative bacteria that are commonly present in injured skin. Both PHMCP and PHMHP hydrogels exhibited upgraded wound-healing efficiency in full-thickness skin defects, characterized by a shorter wound closure time, faster re-regeneration, and the earlier formation of skin appendages, compared with those of control or pure poloxamer treatments. Their biological mechanism was detected. Both PHMCP and PHMHP can regulate the related biofactors during the skin repair process such as interleukin-1β (IL-1β), interleukin-6 (IL-6), transforming growth factor beta-1(TGF-β1), alpha-smooth muscle actin (α-SMA), and vascular endothelial growth factor, to promote wound healing with less serious scarring. In short, hydrogels with excellent capabilities to inhibit microorganism infection and promote wound healing were developed, which will shed light on designing and producing wound dressings with promising applications in future.

In-Situ Mutation Detection by Magnetic Beads-Probe Based on Single Base Extension and Its Application in Genotyping of Hepatitis B Virus Pre-C Region 1896nt Locus Single Nucleotide Polymorphisms

Hepatitis B virus (HBV) is closely related to occurrence and development of viral hepatitis. A mutation of 1896nt locus in its pre-C region can promote replication of HBV DNA and improve stability of pre-genome RNA structure, and can even help HBV evade immune clearance. In this study, magnetic beads-probe (MBs@probe) method, combined with single base extension (SBE) technology, was developed for in-situ mutation detection of HBV pre-C region 1896nt locus. Before successfully completing the genotyping of 165 HBV samples, the crucial reaction conditions were first optimized, such as SBE temperature, MBs size and amount, and probe concentration on the surface of MBs. Experimental results showed that these conditions had significant effects on MBs@probe in-situ mutation detection. Comprehensive considerations, such as 58 °C of SBE temperature, high fluorescence intensity and signal-to-noise ratios (SNRs) were obtained when MBs@probe complex was made by 100 μg of 300 nm-MBs and 3.0 μM of probes in the system. Finally, 1896nt locus mutation in pre-C region of 165 HBV samples was successfully genotyped, among which 71 HBV samples were wild types and the remaining 94 samples were mutant types. Meanwhile, 14 randomly chosen samples were taken to further analyze fluorescence intensity and SNRs respectively, and sequencing results for the first two samples were consistent with results from the MBs@probe in-situ mutation detection method. Compared with two-color fluorescence hybridization (TCFH) genotyping technology, this method generally improves the SNRs to more than 10 (which is more than 2-fold), has higher reliability and is more suitable to detect SNPs for known sites.

Identification of candidate genes for the diagnosis and treatment of cholangiocarcinoma using a bioinformatics approach

Cholangiocarcinoma (CCA) is a biliary epithelial tumor with poor prognosis. As the key genes and signaling pathways underlying the disease have not been fully elucidated, the aim of the present study was to improve the understanding of the molecular mechanisms associated with CCA. The microarray datasets GSE26566 and GSE89749 were downloaded from the Gene Expression Omnibus and differentially expressed genes (DEGs) between CCA and normal bile duct samples were identified. Gene and pathway enrichment analyses were performed, and a protein-protein interaction network was constructed and analyzed. A total of 159 DEGs and 10 hub genes were identified. The functions and pathways of the DEGs were mainly enriched in ‘heparin binding’, ‘serine-type endopeptidase activity’, ‘calcium ion binding’, ‘pancreatic secretion’, ‘fat digestion and absorption’ and ‘protein digestion and absorption’. Survival analysis revealed that the upregulated expression of carboxypeptidase B1 and Kruppel like factor 4 was significantly associated with lower overall survival rate. In summary, the present study identified DEGs and hub genes associated with CCA, which may serve as potential diagnostic and therapeutic targets for the disease.

A Highly Sensitive Strategy for Low-Abundance Hepatitis B Virus Detection via One-Step Nested Polymerase Chain Reaction, Chemiluminescence Technology and Magnetic Separation

Hepatitis B virus (HBV) has been always threatening to health. It is significant to establish an effective strategy for HBV carriers and hepatitis B patients diagnosis at early stage of infection in clinic. Herein, we combined nested PCR, chemiluminescence assay and magnetic separation technology to establish a highly sensitive and stable strategy for low-abundance HBV-DNA detection. Six types of monodisperse Fe₃O₄ magnetic beads (MBs) were fabricated and coated with SiO₂ layer (MBs@SiO₂). The effect of MBs@SiO₂ size on HBV-DNA extraction and chemiluminescence assay was explored, and results displayed that the MBs@SiO₂-F particles with largest size were much more suitable for HBV-DNA extraction than others, and MBs@SiO₂-C with the size range between 330 nm-450 nm performed best in chemiluminescence assay. As one of key factors, the concentration (or density) of the probe fixed on MBs@SiO₂ surface was optimized for chemiluminescence assay, exhibiting the best assay result when reaction system contained 2.0 μM of probe. Finally, under the best reaction conditions, low-abundance HBV serum specimens were sensitively and stably detected, and the result of HBV specimen with 34 copy/mL loads showed significant difference with negative and blank (p < 0.001).

An Aptamer-Based Probe for Molecular Subtyping of Breast Cancer

Molecular subtyping of breast cancer is of considerable interest owing to its potential for personalized therapy and prognosis. However, current methodologies cannot be used for precise subtyping, thereby posing a challenge in clinical practice. The aim of the present study is to develop a cell-specific single-stranded DNA (ssDNA) aptamer-based fluorescence probe for molecular subtyping of breast cancer.

Methods: Cell-SELEX method was utilized to select DNA aptamers. Flow cytometry and confocal microscopy were used to study the specificity, binding affinity, temperature effect on the binding ability and target type analysis of the aptamers. In vitro and in vivo fluorescence imaging were used to distinguish the molecular subtypes of breast cancer cells, tissue sections and tumor-bearing mice.

Results: Six SK-BR-3 breast cancer cell-specific ssDNA aptamers were evolved after successive in vitro selection over 21 rounds by Cell-SELEX. The Kd values of the selected aptamers were all in the low-nanomolar range, among which aptamer sk6 showed the lowest Kd of 0.61 ± 0.14 nM. Then, a truncated aptamer-based probe, sk6Ea, with only 53 nt and high specificity and binding affinity to the target cells was obtained. This aptamer-based probe was able to 1) differentiate SK-BR-3, MDA-MB-231, and MCF-7 breast cancer cells, as well as distinguish breast cancer cells from MCF-10A normal human mammary epithelial cells; 2) distinguish HER2-enriched breast cancer tissues from Luminal A, Luminal B, triple-negative breast cancer tissues, and adjacent normal breast tissues (ANBTs) in vitro; and 3) distinguish xenografts of SK-BR-3 tumor-bearing mice from those of MDA-MB-231 and MCF-7 tumor-bearing mice within 30 min in vivo.

Conclusion: The results suggest that the aptamer-based probe is a powerful tool for fast and highly sensitive subtyping of breast cancer both in vitro and in vivo and is also very promising for the identification, diagnosis, and targeted therapy of breast cancer molecular subtypes.

A Portable Multi-Channel Turbidity System for Rapid Detection of Pathogens by Loop-Mediated Isothermal Amplification

This study aimed at developing a portable multi-channel turbidity system (21 cm in length, 15.5 cm in width and 11.5 cm in depth) by real-time loop-mediated isothermal amplification (LAMP) method for rapid detection of pathogens. The developed system herein includes temperature control unit, photoelectric detection unit, turbidity calibration unit, power management unit, human machine unit, communication unit and ARM-based microcontroller. The coefficient of variation for eight channels is less than 0.25% in noise analysis. Legionella bacteria (LEG) and H7 subtype virus (H7) were successively detected by the designed and developed system within 60 minutes. Moreover, its specificity for LEG is satisfactory and its sensitivity for H7 is 10 copies/mL. Besides, this system for point-of-care diagnosis allows a rapid, small size, low cost, and automatic detection with the characteristics of high-efficiency, excellent stability and high uniformity.

Injectable hydrogels for cartilage and bone tissue engineering

Tissue engineering has become a promising strategy for repairing damaged cartilage and bone tissue. Among the scaffolds for tissue-engineering applications, injectable hydrogels have demonstrated great potential for use as three-dimensional cell culture scaffolds in cartilage and bone tissue engineering, owing to their high water content, similarity to the natural extracellular matrix (ECM), porous framework for cell transplantation and proliferation, minimal invasive properties, and ability to match irregular defects. In this review, we describe the selection of appropriate biomaterials and fabrication methods to prepare novel injectable hydrogels for cartilage and bone tissue engineering. In addition, the biology of cartilage and the bony ECM is also summarized. Finally, future perspectives for injectable hydrogels in cartilage and bone tissue engineering are discussed.

Tissue-specific effects of estrogen on glycerol channel aquaporin 7 expression in an ovariectomized mouse model of menopause

OBJECTIVE

Elevated fat mass and redistribution of body fat are commonly observed in postmenopausal women. Aquaporin 7 (AQP7), a unique glycerol permeable integral membrane protein, has been associated with the onset of obesity. We hypothesized that estrogen supplementation could counteract this fat accumulation and redistribution through tissue-specific modulation of AQP7.

METHODS

We measured fat depot weight, adipocyte size, and the expression of AQP7 and glycerol kinase (GK) in visceral and subcutaneous fat tissues of ovariectomized mice supplemented with or without 17β-estradiol.

RESULTS

Removal of the ovaries resulted in a significant decrease in AQP7 expression and an increase in GK expression in visceral adipocyte tissue; expression of AQP7 and GK in subcutaneous adipose tissue remained unaltered. Supplementation with estrogen significantly restored the visceral, but not subcutaneous, fat depot mass and adipocyte size to those of sham-operated mice. A marked increase in the expression of AQP7 and a reduction of GK were observed selectively in the visceral fat depots in estrogen-treated mice.

CONCLUSIONS

Our results suggest that estrogen has tissue-specific effects on AQP7 expression, and modulation of AQP7 by estrogen alters the balance of adipocyte metabolism between adipose tissue depots.

Integration of Nucleic Acid Extraction Protocol with Automated Extractor for Multiplex Viral Detection

The isolation of nucleic acids (NA) is the preliminary step to carry out genetic studies and DNA biosensor development. The presence of inhibitors in the purified NA interferes with the downstream application. These salts and other organic contaminations particularly challenge the analytical sensitivity of DNA biosensors. The detailed study was carried out to optimize the factors which might affect viral nucleic acid purification. The results suggested that 6 M guanidinium hydrochloride salt concentration was critical for NA isolation. The inverse relation has been found in the pH of the lysis buffer and quality and quantity of NA. The NA yield was relatively stable at pH 4–5. It has been observed that the use of carrier RNA was indispensable for viral genome isolation. The addition of ethanol to lysate in 1:1 ratio greatly improved NA recovery. The elution efficiency of DNase and RNase free water, 1× TE buffer and 1× PCR buffer was compared. The carrier RNA was best eluted in DNase and RNase free water and 1× TE buffer. It was further demonstrated that this method can be automatized for high throughput detection. A simple experiment was conducted to optimize the different parameters of an automated NA extractor to simultaneously extract HBV DNA and HCV RNA. The purified NA was successfully amplified in PCR and RT-PCR to verify the reliability of the established protocol. Thus a semi-automated system for the simultaneous detection of multiple viruses has been demonstrated.

Genetic Variation of BCL2 (rs2279115), NEIL2 (rs804270), LTA (rs909253), PSCA (rs2294008) and PLCE1 (rs3765524, rs10509670) Genes and Their Correlation to Gastric Cancer Risk Based on Universal Tagged Arrays and Fe3O4 Magnetic Nanoparticles

With the help of Fe3O4 nagnetic nanoparticles as a solid carrier and an excellent tool for separation, six SNP loci (rs2279115 of BCL2 gene, rs804270 of NEIL2 gene, rs909253 of LTA gene, rs2294008 of PSCA gene, rs3765524 and rs10509670 of PLCE1 gene) were selected to evaluate their relation to gastric cancer risk. Using two kinds of functionalized magnetic nanoparticles and universal tagged arrays, the whole operation procedure including genome DNA extraction and SNP genotyping was performed. All genotypes and allele frequencies were calculated in the cases and controls respectively to analyze their association with gastric cancer risk. Totally 200 pathological samples and 134 normal control subjects were collected. The results demonstrated that four SNP loci (rs2279115, rs804270, rs909253 and rs3765524) showed a potential association with gastric cancer risk, and the other two (rs2294008, rs10509670) possessed no difference/association among cases and controls.

New species, hyper-diversity and potential importance of Calonectria spp. from Eucalyptus in South China

Plantation forestry is expanding rapidly in China to meet an increasing demand for wood and pulp products globally. Fungal pathogens including species of Calonectria represent a serious threat to the growth and sustainability of this industry. Surveys were conducted in the Guangdong, Guangxi and Hainan Provinces of South China, where Eucalyptus trees in plantations or cuttings in nurseries displayed symptoms of leaf blight. Isolations from symptomatic leaves and soils collected close to infected trees resulted in a large collection of Calonectria isolates. These isolates were identified using the Consolidated Species Concept, employing morphological characters and DNA sequence comparisons for the β-tubulin, calmodulin, histone H3 and translation elongation factor 1-alpha gene regions. Twenty-one Calonectria species were identified of which 18 represented novel taxa. Of these, 12 novel taxa belonged to Sphaero-Naviculate Group and the remaining six to the Prolate Group. Southeast Asia appears to represent a centre of biodiversity for the Sphaero-Naviculate Group and this fact could be one of the important constraints to Eucalyptus forestry in China. The remarkable diversity of Calonectria species in a relatively small area of China and associated with a single tree species is surprising.

Applications of Magnetic Nanoparticles in Targeted Drug Delivery System

Magnetic nanoparticles (MNPs) are a special kind of nanomaterials and widely used in biomedical technology applications. Currently they are popularly customized for disease detection and treatment, particularly as drug carriers in drug targeted delivery systems, as a therapeutic in hyperthermia (treating tumors with heat), and as contrast agents in magnetic resonance imaging (MRI). Due to their biocompatibility and superparamagnetic properties, MNPs as next generation drug carriers have great attraction. Although the potential benefits of MNPs are considerable, any potential toxicity associated with these MNPs should be identified distinctly. The drug loading capability and the biomedical properties of MNPs generated by different surface coatings are the most sensitive parameters in toxicity. A lot of organic and inorganic materials are utilized as coating materials for surface functionalization and reducing toxicity of MNPs. pH or temperature sensitivity materials are widely used to manage drug loading and targeted release. In addition, MNPs can be controlled and directed to the desired pathological region by using external magnetic files (EMF). The realization of targeted drug delivery has decreased the dosage and improved the efficiency of drugs, which results in reduced side effects to normal tissues. This review discussed the possible organ toxicities of MNPs and their current advances as a drug delivery vehicle.

Detection of Pseudomonas aeruginosa based on magnetic enrichment and nested PCR

Pseudomonas aeruginosa is a common opportunistic pathogen in clinics. The species-specific ecfX gene of Pseudomonas aeruginosa has high specificity. In this experiment, we are intended to develop a new method for the detection of Pseudomonas aeruginosa based on magnetic enrichment and nested PCR, and the specific ecfX gene of Pseudomonas aeruginosa was used as the detection object. The genomic DNA of Pseudomonas aeruginosa was extracted using amino-modified magnetic nanoparticles (MNPs). The ecfX gene was amplified by nested PCR and the product of PCR was detected by agarose gel electrophoresis. The results showed that the optimal annealing temperature was 64 degrees C and 62 degrees C respectively in the first and the second rounds of PCR. The lowest concentration of Pseudomonas aeruginosa that could be detected was 10 cfu/mL. The method provides a reliable, timely and accurate technology for early detection of Pseudomonas aeruginosa. Furthermore, the method can shorten the procedure and time from DNA extraction to detection, which made automation more convenient.

Application of functional microsphere in human hepatitis B virus surface antigen detection

A novel and simple emulsifier-free emulsion polymerization technique was developed for preparation of mono-dispersed amino functionalized polymer microspheres with well defined diameters (about 400 nm). Various characterization methods demonstrated that the obtained amino microspheres had a uniform size and good dispersity which were confirmed by scanning electron microscope (SEM). Zeta potential and Fourier transform infrared spectrometer (FT-IR) demonstrated that amino groups have been successfully introduced to the microsphere surface. These functionalized microspheres have been shown to be efficient and controllable carriers capable of immobilizing and enriching monoclonal antibodies. Moreover, a newest chemiluminescent enzyme-linked immunoassay (ELISA) approach has been developed for human Hepatitis B virus surface antigen (HBsAg) detection. HBsAg was sandwiched between goat anti-HBsAg polyclonal antibody and mouse anti-HBsAg antibody. Alkaline phosphatase (ALP) conjugated horse anti-mouse immunnogloblin was used to bond with monoclonal antibody. Finally, chemiluminesent (CL) signals were recorded after adding 3-(2-spiroadamantane)-4-methoxy-4-(3-phosphoryloxy) phenyl-1,2-dioxetane (AMPPD) which was used as a chemiluminescent substrate reagent of ALP. This novel chemiluminescent ELISA assay was proved to be of excellent specificity and high sensitivity when using ALP and AMPPD luminescence systems for specific HBsAg detection.

Magnetic beads-based chemiluminescent assay for ultrasensitive detection of pseudorabies virus

A rapid, ultrasensitive and economical Pseudorabies virus (PRV) detection system based on magnetic beads (MBs) and chemiluminescence was developed in this paper. The carboxyl functionalized MBs (MBs-COOH) were covalently coupled with aminated DNA probes for capturing PRV biotinylated amplicon, the product of polymerase chain reaction (PCR). Agarose gel electrophoresis analysis approved the reliability of biotinylated amplicon. The MBs composites were incubated with alkaline phosphatase labeled streptavidin (ALP-SA) and chemiluminescene was determined by subsequently adding 3-(2'-spiroadamantane)-4-methoxy-4-(3"-phosphoryloxy)phenyl-1,2-dioxetane (AMPPD). The optimal conditions of the PRV detection method were 10 microM for probe concentration, 50 degrees C for hybridization temperature and 30 min for hybridization time. The limit of detection (LOD) was as low as 100 amol/5 pM of amplicon which proved that this approach for PRV detection was ultrasensitive.

An automatic high-throughput single nucleotide polymorphism genotyping approach based on universal tagged arrays and magnetic nanoparticles

Recent developments in highly parallel genome-wide studies are transforming the association of human health and diseases. In these studies, multiple SNP loci from large amount of samples need to be investigated to obtain a result with a high degree of confidence. Herein, we describe a novel, cost-effective and automated method for high-throughput single nucleotide polymorphisms (SNPs) genotyping based on universal tagged array and magnetic separation. By using two kinds of functionalized magnetic nanoparticles, the whole operation procedure including genome DNA extraction and SNP genotyping can be automatically performed by JANUS automated workstation (Perkin Elmer Inc.). Four different SNPs loci from 80 samples were scored using only one pair of universal dual-color probes, the phase of numerous SNPs can be automated assessed simultaneously. The results demonstrated that the expected scores and good discrimination were obtained between the two alleles from these four SNP loci. Due to adequately taking the advantages of high parallel read-out and intrinsically scalable properties of microarray, and the automated magnetic separation handling technology is highly adaptable fro multiplexing sample preparation and automated SNP analysis, also avoid the complex procedure including purification and concentration, the new strategy is high-throughput, simple, flexible, cost-effective, and will be very suitable for large-scale genotyping.

Highly sensitive and rapid detection of Pseudomonas aeruginosa based on magnetic enrichment and magnetic separation

A method for highly sensitive and rapid detection of Pseudomonas aeruginosa, based on magnetic enrichment and magnetic separation, is described in this paper. The magnetic nanoparticles (MNPs) were applied to adsorb genome DNA after the sample was lysed. The DNA binding MNPs were directly subjected to polymerase chain reaction (PCR) to amplify gyrB specific sequence of Pseudomonas aeruginosa. The biotin labeled PCR products were detected by chemiluminescence when they were successively incubated with the probes-modified MNPs and alkaline phosphatase (ALP) labeled streptavidin (SA). Agarose gel electrophoresis analyses approved the method of in situ PCR to be highly reliable. The factors which could affect the chemiluminiscence were studied in detail. The results showed that the MNPs of 400 nm in diameter are beneficial to the detection. The sequence length and the binding site of the probe with a target sequence have obvious effects on the detection. The optimal concentration of the probes, hybridization temperature and hybridization time were 10 μM, 60 ºC and 60 mins, respectively. The method of in situ PCR based on MNPs can greatly improve the utilization rate of the DNA template ultimately enhancing the detection sensitivity. Experiment results proved that the primer and probe had high specificity, and Pseudomonas aeruginosa was successfully detected with detection limits as low as 10 cfu/mL by this method, while the detection of a single Pseudomonas aeruginosa can also be achieved.

Conditions of polymerase chain reaction amplification by magnetic enrichment and nanoscale detection sensitivity

In this research, we reported a method of polymerase chain reaction (PCR) amplification by means of magnetic enrichment. First, after denaturation, the target sequence was combined with biotin-modified specific primer through hybridization and enriched at the surface of gamma-Fe2O3 by biotin-avidin special interaction. Then single target sequence was gained through denaturation, and general PCR amplification was performed. The experiment conditions such as the hybridization temperature between target sequence and biotin-modified specific primer, and the dosage of magnetic nanoparticles gamma-Fe2O3 were optimized. Finally, the sensitivity of the method was checked. The lowest concentration of target sequence was detected as low as 5 x 10(-7) ng/mL. This simple method could provide a quick and early diagnosis of malignant infectious diseases such as SARS, avian flu and swine flu etc., that occur occasionally nowadays.

Low prevalence of human papillomavirus (HPV) in Chinese patients with breast cancer

This retrospective study investigated the presence of human papillomavirus (HPV) in Chinese women with breast cancer, and the correlation between HPV infection and carcinogenesis. Tumour and non-cancerous breast tissue samples were obtained from 62 female patients with breast cancer; normal breast tissue samples were obtained from 46 women without breast cancer. HPV DNA was detected by nested polymerase chain reaction using consensus primers; HPV subtypes were determined by reverse dot blot and pyrosequencing analyses. HPV was found in tumour tissue samples from four of the 62 patients (6.5%), while no HPV DNA was detected in either the non-cancerous samples from patients with breast cancer or from the normal breast tissue controls. Of the four HPV-positive cases, three were HPV 16 positive (75%) and one was HPV 18 positive (25%). The low frequency of HPV detected in this study suggests that this infection is not a major risk factor in breast cancer development.

Prevalence of human papillomavirus in Chinese patients with colorectal cancer

AIM

The prevalence of human papillomavirus (HPV) was determined in Chinese patients with colorectal cancer (CRC). The study also aimed to determine whether the HPV DNA peripheral blood (PB) assay can be used to diagnose HPV-related CRC.

METHOD

Tumour tissue, noncancerous colorectal tissue and whole-blood samples were obtained from 96 patients with CRC. In addition, 32 colorectal tissue samples were harvested from patients without CRC, and 48 whole-blood samples were collected from healthy blood donors. HPV DNA was detected by means of a nested polymerase chain reaction (PCR) using consensus primers, and HPV genotypes were determined by reverse Southern blot and pyrosequencing.

RESULTS

HPV DNA was detected in 32 of the 96 patients with CRC, and colorectal tissues from the 32 control patients without CRC were negative for HPV DNA (P < 0.001). Among 48 healthy donors, three had detectable levels of HPV DNA in their PB. Patients with CRC did not have significantly higher levels of HPV DNA than controls. The HPV prevalence in tumour tissues was higher than that in noncancerous colorectal tissues (P < 0.001) or that in PB samples (P < 0.001). No correlation between the presence of HPV and demographic or medical characteristics was observed. HPV 16 was the viral type most frequently detected and was found in 33 (94%) of 35 HPV-positive patients.

CONCLUSION

HPV infection may be a risk factor for CRC. However, detection of HPV DNA in PB does not appear to reflect the HPV status of CRC.

[The extracting of left ventricular contour based on adaptive directional filter]

This paper proposes the adaptive directional filter, which is exploited for the extracting of left ventricular(LV) contour. This algorithm could produce the exact ridge point by applying directional filter with smoothing operator in the angiography images damaged by noise the Edge Directional Vector as the result of this filter is efficient for predicting the edge ahead, while the filter parameters is adaptive. This proposed method provides the more precise and more automatic--extracting LV contour only with fewer interactions. The experimental results show that this proposed algorithm could improve the accuracy and reproducibility, and reduce the computational consumption remarkably.

Congenital choledochal cyst with pancreatitis

OBJECTIVE

To understand the relationship among congenital choledochal cyst, anomalous junction of pancreaticobiliary duct (AJPBD) and pancreatitis.

METHODS

25 children with choledochal cyst treated in our hospital were included in this study. Their ages ranged from 2 months to 14 years. Intraoperative cholangiography was performed in 24 children. Pancreatic samples obtained from the head and body of the pancreas at operation were observed under light and electron microscope. Serum amylase was analyzed one week before and after operation respectively. Bile amylase in the cyst and gallbladder was measured at operation.

RESULTS

The incidence of AJPBD was 70%. Inflammatory cell infiltration and fibrous hyperplasia were seen in the pancreatic specimens of 5 children, of whom 4 had AJPBD. No ultrastructural changes were found in 2 children without AJPBD, while different changes were seen in 6 with AJPBD, including those showing no pathological changes under light microscope. All the changes became more severe as the age of the patient increased. The bile and serum amylase levels were higher in children with AJPBD than those without AJPBD (P < 0.05).

CONCLUSION

Congenital choledochal cyst has a close relationship with AJPBD and pancreatitis. Pancreatic pathological changes have a long and chronic course from ultrastructural changes to macroscopic changes for the developing of pancreatitis.

Haptotactic and growth stimulatory effects of fibrin(ogen) and thrombin on cultured fibroblasts

We tested the ability of purified, ultraviolet C virally inactivated components of human fibrin sealant (FS) to modulate the chemotaxis, adherence, and proliferation of cultured cells. A fibrin clot formed on a near-confluent layer of human fibroblasts (HFs) recruited cells from the surrounding area. Thrombin (Thr) enhanced HF proliferation by a factor of 1.5 to 1.8, whereas fibrinogen (Fib) exerted only a minimal proliferative effect. We developed a new cell haptotactic/attachment assay by using Thr and Fib covalently bound to Sepharose beads (SBs). The kinetics of cell binding were approximately equivalent for beads coated with either protein. Uncoated SBs or fibrinogen-bound SBs (Fib-SB) pretreated with plasmin did not attract HFs. AlphaThr-SB induced a positive migratory response that was not affected by blocking its proteolytic site, whereas gammaThr-SB elicited no response. X irradiation of HFs at a dose of 6 Gy showed that the migratory response of HF is independent of proliferation, as confirmed by a bromodeoxyuridine uptake assay. Several types of cultured cells (murine fibroblasts, smooth muscle cells, aortic endothelial cells, and murine mammary carcinoma cells) also attached to Fib-SB. By contrast, human keratinocytes, human ovarian carcinoma cells, murine macrophage-like cells, leukemic cells, and murine mast cells did not attach. Our results provide some mechanistic insights into the haptotactic and proliferative effects of Fib and Thr on different cells.

Combination of cisplatin and radiation in cell culture: effect of duration of exposure to drug and timing of irradiation

Responses to the combination of cisplatin (CDDP) and radiation in experimental and clinical studies have been reported to vary from high radiosensitization to clear sub-additivity. We examined the combined effect of CDDP with ionizing radiation in both murine mammary adenocarcinoma (EMT-6) and human ovarian carcinoma (OV-1063) cells with special reference to the duration of CDDP exposure and timing of irradiation. Cell survival was measured with a colorimetric assay of cell density. The nature of interaction of cisplatin and radiation was evaluated using isobolograms and a combination index (CI). Exposure of both cell lines to CDDP for 24 hr before irradiation yielded an additive or slightly sub-additive response only if the exposure was extended for a few more hours after irradiation. In EMT-6 cells, the combination of radiation with subsequent continuous as well as short-term (4 to 6 hr) CDDP treatment was found to have a clear sub-additive effect; dose escalation of each modality reduced the additional effect of the other. The sub-additive effect may be explained by a radiation-induced arrest of cells in late S phase, which was dose- and time-dependent. Post-radiation exposure to CDDP further increased the S-phase arrest. In contrast, a 2 hr post-radiation drug exposure resulted in a supra-additive combined effect. Our results stress the crucial role of the timing and the doses of both modalities as well as the duration of post-radiation drug exposure on their combined effect.

[Effects of low concentration carbon monoxide on human physiological function]

Human volunteers were exposed to various low concentrations of carbon monoxide (CO) in a closed cabin. The results showed that 35 mg/m3 of CO caused slight subjective symptoms and reduction in contrast vision, operating efficiency and T-wave of ECG. At 80 mg/m3 and 115 mg/m3 the above changes were more severe and a rise in hearing threshold level was observed. It demonstrated that an inhibitory effect on the CNS and heart were caused by low concentrations of CO. According to the absorption curves for human exposed to CO, it is suggested that the sense effect level and vision effect level for CO are 7% COHb, and the hearing effect level is 9% COHb.

Virucidal treatment of blood protein products with UVC radiation

The virus safety of blood derivatives continues to be of concern, especially with respect to nonenveloped and/or heat-stable viruses. Previously, we demonstrated that treatment of whole plasma, AHF concentrate or fibrinogen with short wavelength ultraviolet light (UVC) results in the inactivation of > or = 10(6) infectious doses (ID) of encephalomyocarditis virus (EMCV), hepatitis A virus (HAV) and porcine parvovirus (PPV), each of which is nonenveloped. Protein recovery was enhanced greatly by inclusion of the flavonoid, rutin, added prior to UVC exposure to quench reactive oxygen species. We now report on the treatment of albumin and intravenous immune globulin (IVIG) isolated by a previously described, integrated chromatographic method. Albumin was treated with either 0.1 or 0.2 J/cm2 UVC in the presence of 0.8 or 1.6 mM rutin; IVIG was treated with either 0.05 or 0.1 J/cm2 UVC in the presence of 0.5 or 1.0 mM rutin. Our results show that > or = 10(6.9) ID of EMCV and PPV were inactivated under each of the conditions studied except the treatment of albumin with 0.1 J/cm2 UVC in the presence of 1.6 mM rutin where 10(4.3) ID of EMCV and > or = 10(6.9) ID of PPV were killed. It appears that the sensitivity of PPV to UVC exceeds that of EMCV and that virus kill with UVC is higher in IVIG than in albumin. In the absence of rutin, UVC increased the extent of aggregation of both albumin and IVIG by two- to three-fold. With rutin present, the increase in albumin aggregation was reduced, and it was virtually eliminated by subsequent processing on Sephacryl S-200, a step in the existing procedure designed to remove aggregates. The increase in aggregation of IVIG appeared to be eliminated on inclusion of either 0.5 mM or 1 mM rutin. We conclude that both albumin and IVIG can be treated with UVC to inactivate > or = 10(6) ID of nonenveloped viruses. The inclusion of rutin during treatment helps protect against protein aggregation.

Protecting fibrinogen with rutin during UVC irradiation for viral inactivation

Fibrinogen solutions were irradiated with UVC (254 nm) to inactivate contaminating viruses. In order to protect fibrinogen during UVC irradiation, 0.5 mM rutin was added prior to UVC exposure and subsequently removed during processing. Viral kill by 0.1 J/cm2 UVC resulted in the following inactivation values (log 10): non-lipid-enveloped viruses: Parvo > or = 5.5; encephalomyocarditis virus > or = 6.5; hepatitis A virus > or = 6.5: lipid-enveloped viruses: human immunodeficiency virus > or = 5.7; vesicular stomatitis virus > or = 5.7. Fibrinogen irradiated with 0.5 mM rutin did not significantly differ from unirradiated material in terms of clot time and breaking strength. In the absence of rutin, UVC irradiation of fibrinogen at similar fluence led to loss of solubility, increased clot time and the cleavage of fibrino-peptides that reacted with dinitrophenyl hydrazine as a test for ketonic carbonyl groups. High-performance liquid chromatography and mass spectrometry data showed that rutin exposed to UVC formed numerous breakdown, oxidation and combinational products. Experiments with 3H-rutin showed that after UVC irradiation, subsequent processing by a C18 resin and alcohol precipitation removed > 99% rutin, representing < 10 ppm rutin in the final fibrinogen preparations. Residual 3H-rutin was not covalently bonded to the fibrinogen. Immunochemical studies with rabbit antisera to UVC irradiated (with rutin) fibrinogen showed the absence of neoimmungens. By all measures, rutin prevents fibrinogen degradation during virucidal UVC irradiation.

Reduction of the systemic toxicity of cisplatin by intra-arterial hepatic route administration for liver malignancies

Cisplatin (CDDP) administration by the intra-arterial hepatic route (i.a.h.) in patients with primary or metastatic liver malignancies could enhance the anti-tumor activity of the drug and reduce its systemic toxicity. The aim of the present study was to compare Pt pharmacokinetics and the toxicity of the circulating drug after i.a.h. versus intravenous (i.v.) administration. CDDP pharmacokinetics was followed-up in 11 i.a.h. courses given to 7 patients with liver malignancies and compared with 19 i.v. courses in 15 patients with cancer of different origins. The Pt level in blood was monitored by sensitive atomic absorption spectrometry. The dose given was in the range of 25-80 mg/m2/treatment. For analysis and for comparison purposes, the data from both CDDP treatments were normalized to a standard dose of 35 mg/m2. The mean peak Pt level for i.a.h. treatment was found to be about half of the mean peak value for i.v. administration with a similar dose-independent bi-exponential rate of elimination i.a.h. CDDP treatment was relatively well tolerated with no symptoms of either nephro- or neurotoxicity. For in vitro evaluation of peripheral CDDP toxicity, a sensitive ovarian carcinoma cell line, OV-1063, was used. A cytotoxic effect was recorded only within 2 hr following high-dose i.v. CDDP treatment. A substantial fraction of the drug given by the i.a.h. route was found to be extracted by the liver in the first passage, with reduced drug level in the peripheral blood plasma relative to the dose given. This may explain the apparent diminution of side-effects following i.a.h. CDDP treatment.

Sub-additive effect of the combination of radiation and cisplatin in cultured murine and human cell lines

The use of cisplatin (CDDP) as a potential radiosensitizer in tumors is controversial. Reports about CDDP interaction with radiation range from high radiosensitization to a clear sub-additive effect. We examined the effect of the combination of different concentrations of CDDP with radiation in murine mammary adenocarcinoma (EMT-6) and human ovarian carcinoma (OV-1063) cell lines. CDDP was given in the dose range of 0.01-3.0 micrograms/ml and radiation in the dose range of 1-6 Gy. A methylene blue assay of cell density was used for the evaluation of cell survival and rate of proliferation in 96-microwell plates. The validity of this assay for evaluation of cell survival was verified by colony-forming assay and radiolabeled thymidine uptake. The dose response to CDDP for both OV-1063 and EMT-6 cells lines was examined; the ID50 was 0.06 and 0.9 micrograms/ml respectively. A sub-additive effect of the combination of radiation with CDDP was clearly observed in the two cell lines tested; the increase in dose of each modality resulted in a decrease of the relative contribution on the effect of the other. These findings question the rationale of combining CDDP with radiation for the enhancement of tumor response, since with the increase in the dose of either modality the additional effect of the other decreases.

Packaging zinc, fibrinogen, and factor XIII in platelet alpha-granules

Zinc(II) accumulated by platelets has profound effects on platelet activity. This study is focused on the distribution of Zn(II) between human platelet subcellular compartments. After incubation with 86Rb+ and platelet lysis, the organelles were separated by sucrose density gradient centrifugation. Fibrinogen served as a marker for alpha-granules. 86Rb+ and factor XIII served as markers for the cytoplasmic fractions. Zn(II) was found to be distributed between the cytoplasm and the alpha-granules, with variations between different individual units. The total platelet Zn concentration and its relative subcellular distribution were dependent on its extracellular level. Incubation of platelets with 100 microM Zn(II) resulted in a twofold increase of its level in the cytoplasm and by one order of magnitude in the alpha-granules. In addition to the anticipated factor XIII activity in the cytoplasmic pool fraction, we found thrombin-inducible factor XIII activity within the alpha-granules. Immunoblotting confirmed the presence of both the a and b subunits of plasma factor XIII (a2b2 form) in the alpha-granules. As fibrinogen is not synthesized in the platelet, we propose that by virtue of their mutual binding, fibrinogen, Zn(II) and plasma factor XIII-a2b2 are simultaneously taken up into the alpha-granules by endocytosis, presumably through the vehicle of the GPIIb/IIIa fibrinogen receptor. A rationale for co-packaging these components within the alpha-granules is that Zn(II) inhibits factor XIII activity and thereby prevents the premature cross-linking of the concentrated fibrinogen prior to platelet activation and secretion. By contrast, cytoplasmic Zn(II) may increase platelet responsiveness to agonists due to its interaction with cytoplasmic modulators of platelet activity.

Noninvasive follow-up of platinum pharmacokinetics in the skin of patients on cisplatin chemotherapy

BACKGROUND

Treatment with high-dose cisdiammine-dichloroplatinum (II) (cisplatin, cDDP) often is associated with late complications, predominated by peripheral neuropathy. Pt deposition in different tissues may play a key role in the induction of many of these effects. Main topics of interest include the relationship between cDDP doses given during treatment and the long-term pharmacokinetics of the drug complexes in normal tissues and blood. Noninvasive examination of Pt in tissues during and after cDDP treatment are needed to clarify these points.

METHODS

A novel, high-sensitivity diagnostic x-ray spectrometry (DXS) method was used for the fast, noninvasive analysis of Pt in external tissues of patients with cancer treated with courses of cDDP. The Pt in a small skin area was excited by a monochromatic soft x-ray beam (14.6 KeV) and the spectral L lines emitted from the tissue were detected. A limit of detection below 1 microgram/g wet weight was reached. The pharmacokinetics of Pt in blood was investigated in parallel with the use of high-sensitivity, flameless atomic absorption spectrometry (AAS).

RESULTS

Follow-up of Pt concentrations in the skin of patients with cancer by DXS before cDDP treatment, during treatment, and up to 4 months after its completion, showed prolonged Pt deposition that corresponded to the net cumulative doses of the drug. Pt clearance from the skin fitted a monoexponential curve with a half-life of about 30 days. In comparison, the pharmacokinetics of total Pt in plasma showed a much faster, biexponential clearance with half-lives of 41 minutes and 5.2 days, respectively.

CONCLUSIONS

The amount of nonspecific Pt deposition in the tissues was found to depend on the total doses administered, the time interval between the courses, and the slow rate of clearance. Noninvasive measurements of tissue Pt levels may serve as a major tool in the evaluation of the induction of late cDDP complications.

A sensitive noninvasive analysis of Pt in external tissues. Followup of Pt deposition following cisplatin treatment

Noninvasive analysis of heavy elements in external tissues by diagnostic-x-ray spectrometry (DXS) is presented. Pt can be detected accurately with sensitivity below 1 microgram/g wet weight of tissue. In the present paper the possibility to monitor Pt accumulation and clearance in the external tissues of cancer patients treated with cisplatin [Cis-diamminedichloroplatinum (II)-cDDP] chemotherapy is reported. The DXS method is based on x-ray fluorescence analysis. Heavy elements in the small skin area of interest are analyzed by their excitation with a monochromatic soft x-ray beam of 14.6 KeV. Spectral L lines of heavy metals such as Pt are detected with minimum interference by other elements in the tissues. Skin Pt levels up to about 6 micrograms/g were observed following several courses of cDDP treatment. The Pt seemed to be homogeneously distributed in different skin areas with similar levels in the dermis and epidermis. The rate of clearance of Pt from the skin (50% in about 30 days) was slower by three orders of magnitude than its clearance from plasma. Further studies may use DXS to establish the accurate kinetics of Pt deposition and clearance in tissues of cDDP treated patients, as well as the exact relation between tissue Pt levels and the development of the drug related late complications.

Platelet multielemental composition, lability, and subcellular localization

Diagnostic X-ray spectrometry (DXS), based on X-ray fluorescence, was used to quantitate directly the multiple elemental composition of washed, intact human platelets (n = 16), with the following results: K = 3.08 +/- 1.00 mg/g, Ca = 1.18 +/- 0.29 mg/g, Zn = 35 +/- 9 micrograms/g. These values show that washed platelets contain significant pools of K, Ca, and Zn, the latter some 30-60-fold higher than plasma levels. Dialysis of whole platelets against cation exchange resin (Chelex-100) did not extract Ca(II) and Zn(II) sequestered within whole cells. To identify the subcellular locale of the elements, platelet lysate was subjected to 30-70% sucrose gradient ultracentrifugation and subcellular enriched fractions were obtained. Fractions were analyzed by DXS (for elements), electron microscopy (for dense granules), and subcellular markers fibrinogen and von Willebrand factor. In contrast to Ca and K, which accumulate in the dense granules and the cytoplasm, respectively, Zn appears to be distributed in the alpha-granules (40%) and the cytoplasm (60%). The subcellular distribution of Zn(II) is discussed within the context of the sensitivity of platelet response to the availability of Zn(II) and the platelet release reactions following stimulation.