Characteristics and interplay of esophageal microbiota in esophageal squamous cell carcinoma.

BACKGROUND: Esophageal microbiota may influence esophageal squamous cell carcinoma (ESCC) pathobiology. Therefore, we investigated the characteristics and interplay of the esophageal microbiota in ESCC. METHODS: We performed 16S ribosomal RNA sequencing on paired esophageal tumor and tumor-adjacent samples obtained from 120 primarily ESCC patients. Analyses were performed using quantitative insights into microbial 2 (QIIME2) and phylogenetic investigation of communities by reconstruction of unobserved states 2 (PICRUSt2). Species found to be associated with ESCC were validated using quantitative PCR. RESULTS: The microbial diversity and composition of ESCC tumor tissues significantly differed from tumor-adjacent tissues; this variation between subjects beta diversity is mainly explained by regions and sampling seasons. A total of 56 taxa were detected with differential abundance between the two groups, such as R. mucilaginosa, P. endodontalis, N. subflava, H. Pylori, A. Parahaemolyticus, and A. Rhizosphaerae. Quantitative PCR confirmed the enrichment of the species P. endodontalis and the reduction of H. Pylori in tumor-adjacent tissues. Compared with tumor tissue, a denser and more complex association network was formed in tumor-adjacent tissue. The above differential taxa, such as H. Pylori, an unclassified species in the genera Sphingomonas, Haemophilus, Phyllobacterium, and Campylobacter, also participated in both co-occurrence networks but played quite different roles. Most of the differentially abundant taxa in tumor-adjacent tissues were negatively associated with the epidermal growth factor receptor (EGFR), erb-b2 receptor tyrosine kinase 2 (ERBB2), erb-b2 receptor tyrosine kinase 4 (ERBB4), and fibroblast growth factor receptor 1 (FGFR1) signaling pathways, and positively associated with the MET proto-oncogene, receptor tyrosine kinase (MET) and phosphatase and tensin homolog (PTEN) signaling pathways in tumors. CONCLUSION: Alterations in the microbial co-occurrence network and functional pathways in ESCC tissues may be involved in carcinogenesis and the maintenance of the local microenvironment for ESCC.

Polyethylene glycol loxenatide (PEX168) in subjects with renal impairment: A pharmacokinetic study.

AIMS: Type 2 diabetes mellitus (T2DM) is commonly complicated by renal impairment. Polyethylene glycol loxenatide (PEX168) is a novel long-acting glucagon-like peptide-1 receptor agonist for T2DM. PEX168 pharmacokinetics was studied to identify requirements for dose-modification in T2DM complicated by renal impairment. METHODS: This was a single-centre, open-labelled, parallel-group, single-dose, phase I clinical trial of patients with mild and moderate renal impairment, and with or without T2DM. Age-, sex- and body mass index-matched subjects with normal renal function, and with or without T2DM were recruited as controls. Subjects received a single abdominal subcutaneous injection of PEX168 200 µg. Pharmacokinetic samples were taken at 0, 24, 48, 72, 96, 120, 144, 216, 312, 480, 648 and 720 hours. RESULTS: Twenty-three patients were included in the pharmacokinetics analysis. Vz/F and CL/F were lower in the moderate impairment group than in the other groups. The mean t1/2 (163 hours) in the moderate impairment group was prolonged compared to the mild impairment (117 hours) and normal (121 hours) groups. AUC0-inf increased by 13 and 100.7% in patients with mild and moderate renal impairment, respectively. Most adverse events were mild gastrointestinal disorders, with only 1 serious adverse event observed. CONCLUSION: A single dose of 200 µg of PEX168 was in general well tolerated in patients with renal impairment. The in vivo clearance rate of PEX168 in patients with moderate renal impairment is slower than in patients with mild renal impairment and normal renal function and dose adjustment might be required (ClinicalTrials.org #NCT02467790).

Stabilization of residues obtained from the treatment of laboratory waste: Part 2--transformation of plasma vitrified slag into composites.

The Sustainable Environment Research Center of National Cheng Kung University in Taiwan has set up a treatment plant to dispose of laboratory waste. In the treatment process, the residue from the incineration system and the physical and chemical system is vitrified by a plasma melting system. Part 1 of this study described the treatment path of metals during vitrification. In Part 2, plasma vitrified slag is reused by using a molding technology. Unsaturated polyester resin and glass fiber were used as the molding material and additive, respectively, in the molding process. With an appropriate mixing ratio of unsaturated polyester resin, glass fiber, and slag, the physical properties of composites improved, and the ultimate tensile strength reached 17.6 MPa. However, an excess amount of slag reduced the strength and even retarded the production of composites. Differential thermal analysis and the water bathing test results show that the composite decomposed at 80 degrees C and that it vaporized at 187 degrees C. Although the unsaturated polyester resin decomposed, the metal encapsulated in the slag did not leach out. The results show that the reuse of slag using molding technology should be taken into consideration.

Silencing of the MYCN gene by siRNA delivered by folate receptor-targeted liposomes in LA-N-5 cells.

INTRODUCTION: MYCN amplification is highly associated with malignancy and correlates with poor prognosis in patients with neuroblastoma. MATERIALS AND METHODS: We developed a novel liposome-MYCN siRNA-folic acid complex, and the transfection efficacy was measured in LA-N-5 cells by cy-3 fluorescence density in each microgram of protein from the transfected cell lysate. MYCN expression and cell growth were studied with quantitative RT-PCR and MTT assays, and the expression of MYCN protein was studied with Western blot, respectively. An SCID mouse model with subcutaneous LA-N-5 xenografted tumor was established. The animals were divided into four groups (n = 5) and they were peritoneally injected with liposome-encapsulated MYCN siRNA (siRNA 125 µg/kg/day), lipid-encapsulated control siRNA, MYCN siRNA, or liposome only, respectively, for 5 consecutive days. The animals were killed 24 h after the last injection, and the expression of MYCN mRNA in tumor tissue was detected by RT-PCR. RESULTS: Our results are as follows: the transfect efficacy reached 1808.5 ± 140.2 pg siRNA/µg protein in LA-N-5 lysates after treatment with 100 nmol/L MYCN siRNA encapsulated with lipid, and fluorescence could be visualized in 92% of LA-N-5 cells after transfection. At 72 h post-transfection, MYCN mRNA expression in LA-N-5 cells was downregulated by 79.2%, MYCN protein was downregulated by 71.3% and cell growth was inhibited by 66.2%, as measured by MTT assay. In the in vivo study, MYCN mRNA expression was knocked down 53.1% in tumor tissues with injection of liposome-encapsulated MYCN siRNA as compared to control siRNA. CONCLUSION: These results suggest that targeted delivery of MYCN siRNA by folate receptor-targeted lipid vesicles into LA-N-5 cells is efficacious and capable of suppressing MYCN mRNA expression both in vitro and in vivo.

Sugar-mediated chitosan/poly(ethylene glycol)-beta-dicalcium pyrophosphate composite: mechanical and microstructural properties.

The microstructural and mechanical properties of sugar-mediated chitosan/poly(ethylene glycol)-based scaffolds and composites, which are composed of beta-dicalcium pyrophosphate (beta-DCP) and sugar-mediated scaffolds, were investigated. All of the scaffolds were prepared by various freeze-drying protocols. The differences in the freeze-drying process of the sugar-mediated chitosan/poly(ethylene glycol) scaffold for three types of sugar (sucrose, glucose, and D-fructose) were determined by scanning electron microscopic observation, water retention, density, and porosity analyses. The sugar-mediated scaffolds prepared by scheme I of the freeze-drying process show large pores, poorly connective interlayers, and disintegrated inner structures, different from the small pores and well-connective channel structures as shown in the scheme II freeze-drying process. The key factors for controlling pore structure and size in the scheme I freeze-drying process were formulation and composition, but for the scheme II freeze-drying process, the key factor was freeze protocol. The composite scaffolds were macroporous, and the microstructure changed considerably with added beta-DCP content. The incorporation of beta-DCP granules caused a significant enhancement of compressive modulus and yield strength. The increased mechanical strength may be attributable not only to the physical complexation between the sugar-mediated scaffold and beta-DCP, but also the chemical reaction to apatite formed on the cell wall.

Synthesis of nanosized chitosan-poly(acrylic acid) particles by a dropping method.

Deoxyribonucleic acid (DNA) vaccines are being investigated extensively because of their excellent potential over conventional protein ones. A suitable DNA carrier, consisting of uniformly dispersed chitosan-poly(acrylic acid) particles with an average size of 30 nm, was successfully synthesized by a dropping method with a ratio of chitosan solution to poly(acrylic acid) solution of 1:1 and was incubated in a buffer solution with a pH value of 3.0. The particle size increased from 35.76 to 45.90 nm when the pH value of the buffer solution was increased from 3.0 to 7.4. After freeze-drying, the non-incubated mixed solution showed a membranous morphology. A powdered product was formed from the mixed solution as incubated in buffer solution with pH values of 3.0 and 5.3. However, when the mixed solution was incubated in a buffer solution of pH 7.4, a mixture of membrane and powder was obtained.

[Ex vivo chemical modification of graft cells by methoxy polyethylene glycol alleviates graft versus host disease after haploidentical stem cell transplantation in mice].

This study was aimed to explore the effect of ex vivo chemical modification of graft cells with methoxy polyethylene glycol (mPEG) on graft versus host disease (GVHD) after haploidentical stem cell transplantation in neonatal mice and its influence on activity of the stem cells. The modified and non-modified spleen cells of adult CB6F1 mice were injected into the abdominal cavity of neonatal BALB/c mice with 5x10(6) spleen cells per mouse, and GVHD were measured by spleen index (SI). Furthermore, the modified and non-modified mixture of bone marrow and spleen cells (BMS) were transplanted to haploidentical lethally irradiated adult BALB/c mice via tail vein with 2x10(5) BMS per mouse, and the colony forming units of spleens (CFU-S) were counted on the eighth day after irradiation. The results indicated that SI1 in modification group were lower than that in non-modification group, and SI2 in modification group was <1.3, showing that GVHD in modification group were less severe. The numbers of CFU-S formed in both modification group and non-modification group were not significantly different (p>0.05), indicating that the activity of the stem cells were not affected by mPEG modification. In conclusion, the modification of graft cells with mPEG alleviates GVHD after haploidentical stem cell transplantation in neonatal mice, and do not influence the activity of the stem cells.

Effects of sugar cross-linking agents and thermal treatment on the culture of fibroblasts in vitro on a (PEG/chitosan) membrane.

The influences of sugar and a thermal treatment process on the properties of a PEG/chitosan membrane were investigated in this study. With increasing thermal treatment temperature, the cross-linking density was increased and the crystal structure was distorted in the sugar-mediated polyblend. The coloration of the samples intensified from yellow or brown to dark brown during the heat exposure, indicating that a Schiff base was formed. The presence of cross-linking was determined from the FTIR spectrum, a solubility test, and water uptake. The C=N bonding shown in the FTIR spectrum indicates that a Maillard reaction occurred in the sugar-mediated polyblend. The water uptake ability of the samples tested was in the following sequence: sucrose > glucose > D-fructose, which was inverse to the trend of the cross-linking density. The compatibility of the polyblend and the sugar-mediated polyblend with fibroblasts was demonstrated. The thermal treatment has an insignificant effect on cell attachment on chitosan and the other polyblends, but different types of sugar and the cross-linking density changed the cell behavior. Consequently, chitosan/PEG6K cross-linked with sucrose at a concentration of 10 wt% and 120 degrees C thermal treatment shows potential for biomedical applications.

[Effect of chemical modification of grafts on the survival improvement post haploidentical bone marrow transplantation in mice].

OBJECTIVE: Human leukocyte antigen (HLA) haploidentical bone marrow is a potential source of donor to children for its availability. The drawback is deleterious graft versus host disease (GVHD) reaction post transplantation because of the incompatibility of HLA antigen expression between donors and recipients, in which donor T lymphocyte is stimulated to proliferate and differentiate. The methoxy polyethylene glycol (mPEG) is a kind of amphoteric compound without immunogenicity, which was used to modify various proteins covalently and to prepare the versatile blood type. If mPEG modification blocks the activation of T cells in grafts, GVHD reaction probably would become less serious and transplantation might become successful. The aim of this study was to verify the improvement of haploidentical bone marrow transplantation (BMT) in a murine model by using mPEG of certain concentration to modify the grafts. METHODS: Male BALB/c mice were chosen as the donor, and female CB(6)F(1) mice as the recipient. There were three groups of mPEG modification, non-modification and irradiation control, and 20 mice in each group. The modified and non-modified mixture of bone marrow and spleen cells (as T lymphocytes) were transplanted to haploidentical lethally irradiated CB(6)F(1) mice via the tail vein. After the transplant, the hematopoietic recovery, survival rate, acute graft versus host disease (aGVHD) and chromosomal karyotype were analyzed and compared with controls. RESULTS: Seventy-five percent (15/20) of mice survived in the group of mPEG modification, while only 40% (8/20) survived in the group without the modification (chi(2) = 5.01, P = 0.025). And 100% mice died in the group of the irradiation control within 2 weeks. The hematopoietic recovery in the group of mPEG modification was show n to be faster than that in the group without modification (P < 0.05). Histopathological examination of the skin, liver and intestine showed typical signs of aGVHD, but the GVHD grading in the group of modification was less severe. The recipient mice in both groups of transplantation surviving for more than 75 days showed complete donor-type implantation by the chimerism examination. CONCLUSION: The modification of grafts by mPEG could alleviate aGVHD and improve the survival rate of mice after the haploidentical bone marrow transplantation.