Identification of Per a 13 as a novel allergen in American cockroach.

BACKGROUND: Cockroaches are an important source of indoor allergens. Environmental exposure to cockroach allergens is closely associated with the development of immunoglobulin E (IgE)-mediated allergic diseases. However, the allergenic components in the American cockroaches are not fully studied yet. In order to develop novel diagnostic and therapeutic strategies for cockroach allergy, it is necessary to comprehensively investigate this undescribed allergen in the American cockroach. METHODS: The full-length cDNA of the potential allergen was isolated from the cDNA library of the American cockroach by PCR cloning. Both the recombinant and natural protein molecules were purified and characterized. The allergenicity was further analyzed by enzyme linked immunosorbent assay, immunoblot, and basophil activation test using sera from cockroach allergic patients. RESULTS: A novel allergen belonging to glyceraldehyde 3-phosphate dehydrogenase (GAPDH) was firstly identified in the American cockroach and named as Per a 13. The cDNA of this allergen is 1255 base pairs in length and contains an open reading frame of 999 base pairs, encoding 332 amino acids. The purified Per a 13 was fully characterized and assessed to react with IgEs from 49.3 % of cockroach allergic patients, and patients with allergic rhinitis were more sensitized to it. Moreover, the allergenicity was further confirmed by immunoblot and basophil activation test. CONCLUSIONS: We firstly identified GAPDH (Per a 13) in the American cockroach, which is a novel type of inhalant allergen derived from animal species. These findings could be useful in developing novel diagnostic and therapeutic strategies for cockroach allergy.

[Impact of a Sewage Treatment Plant on the Accumulation of Microplastics in Freshwater Organisms in the Lijiang River of the Guilin Urban Section].

Microplastics (MPs, particle size<5 mm), as a new pollutant, have attracted wide attention in recent years. The distributions of MPs in effluent of a sewage treatment plant (STP) were examined. Surface water, sediment, and freshwater organism samples were taken from the STP discharge outlet in the Lijiang River tributary (S1), the confluence of tributaries and main streams in the Lijiang River (S2), and downstream locations in the Lijiang River (S3). The impact of STP discharge effluent on the characteristics and spatial distribution of MPs pollution in freshwater organisms was studied. The results showed that the freshwater organisms had a probability of uptake of MPs by 94.2%. The mean abundance of MPs in S1 (2.7 n·ind-1) was significantly higher than that of S3 (1.9 n·ind-1, P<0.05). The MPs found in S1 and S3 were mainly <0.10 mm, accounting for 46.0% and 30.5%, respectively. The fiber type of MPs was observed in the body of freshwater organisms. Polyethylene terephthalate was the major polymer form in S1 organisms, while polypropylene was the major polymer form in S3. The effluent discharged from the STP led to the accumulation of MPs in freshwater organisms.

Aerobic removal of iodinated contrast medium by nano-sized zero-valent iron: A combination of oxidation and reduction.

The removal performance and mechanisms of diatrizoate (DTA), a typical iodinated contrast medium, from water by nano-sized zero-valent iron (nZVI) under aerobic conditions were investigated in this study. Reactive oxygen species (ROS) and transformation products were detected with electron spin resonance and liquid chromatography electrospray ionization tandem mass spectrometry, respectively. Furthermore, the effects of several operational parameters on DTA removal were illustrated. The results showed that nZVI had a much higher DTA removal ability compared to microscale zero-valent iron (mZVI) in the presence of oxygen. Moreover, the detection of ROS and I- as well as the analysis of intermediate products suggested a combination of oxidation and reduction pathways for DTA removal by nZVI under aerobic conditions. Additionally, a high dosage of nZVI and acidic conditions led to the enhancement of DTA removal, while nZVI aging, as well as chloride and nitrate ions in the solution, had negative effects on the degradation of DTA by nZVI in the presence of oxygen.

[Biomechanical research of antegrade intramedullary fixation for the metacarpal fractures].

OBJECTIVE: To study the biomechanical characteristics of antegrade intramedullary fixation for metacarpal fractures. METHODS: From March to May 2008, both the 4th and 5th metacarpals from 25 formalin embalmed cadaver hands had three-point bending test after transverse osteotomy followed by randomly fixation with one of the following three methods: plate and screw, antegrade intramedullary K-wire, crossed K-wire. While, both the 2nd and 3rd metacarpals had torsional loading test after the same management as the 4th and 5th metacarpal had undergone. RESULTS: In the three-point bending test, both the maximum bending moment (M(max)) and bending rigidity (EI) of the antegrade intramedullary K-wire were comparable with those of the plate and screw, and were significantly larger than those of the crossed K-wire. In the torsional loading test, the antegrade intramedullary K-wire had a statistically smaller maximum torque (T(max)) than the plate and screw, and had a comparable T(max) with the crossed K-wire; while, the torsional rigidity (GJ) of the intramedullary K-wire was statistically weaker than that of both the plate and screw and the crossed wire. CONCLUSIONS: One single antegrade intramedullary K-wire can provide a satisfactory M(max) and EI for metacarpal fixation and shows relatively weak in the torsional loading test. The injured finger should be well protected to avoid torsional deformity in clinical practice.

[Mutations in the D-loop region of mitochondrial DNA and the ROS level in the tissue of hepatocellular carcinoma].

To explore the relationship between ROS level and mutations in D-Loop region of mtDNA, mutations in the D-Loop region of mtDNA and the ROS level in primary hepatocarcinoma tissues were studied. We amplified the D-Loop region of mtDNA of 20 hepatocarcinomas and their adjacent tissue by PCR and then sequencing. ROS in tissue was measured by flow cytometry. mtDNA mutations were detected in 40% (8 of 20) tumor samples. 53 point mutations were detected in eight tumour samples, including 2 insertions, 11 deletions and 40 point mutations. 75% point mutations were T-C and C-T transition. They were four microsatellites among the mutations. Mutations in the adjacent tissues were always companied with mutations in tumour tissues. The mutation frequency in tumour tissues was higher than that in adjacent tissue. There was a larger unidentified deletion. The ROS level in hepatocarcinoma tissue was much higher than control (P<0.01). Meanwhile, we found the ROS level in hepatocarcinoma tissues with mutated mtDNA D-Loop was higher than that hepatocarcinoma tissue normal mtDNA D-Loop, and the ROS level in hepatocarcinoma adjacent tissue with mutated mtDNA D-Loop was higher than that in hepatocarcinoma adjacent tissue with normal mtDNA D-Loop. It was concluded that the D-Loop region of mitochondrial DNA was a highly polymorphoric and mutable region and mutation rate was relatively high in patients with hepaticellular carcinoma, and the abnormal ROS level might be the point mutation in the mitochondrial DNA and hepatocarcinogenesis related to ROS.

Herpes simplex virus thymidine kinase and ganciclovir suicide gene therapy for human pancreatic cancer.

AIM: To investigate the in vitro effects of suicide gene therapy system of herpes simplex virus thymidine kinase gene (HSV-TK) in combination with the treatment of nucleotide analog-ganciclovir (GCV) on human pancreatic cancer, and to provide a novel clinical therapeutic method for human pancreatic cancer. METHODS: We used a replication defective recombinant retrovirus vector GINaTK (bearing HSV-TK gene) to make packaging cell PA317 produce progeny virions. We then transferred the HSV-TK gene to target cells SW1990 using these progeny virions, and treated these gene-modified tumor cells with GCV to study the sensitivity of the cells to GCV and their bystander effects by routine MTT-method. RESULTS: Packaging cell PA317/TK was successfully constructed, and we acquired SW1990/TK through virus progeny infection. These gene-modified pancreatic cancer cells were sensitive to the treatment of GCV compared with unmodified tumor cells (t=4.15, n=10, P<0.0025). We also observed a remarkable bystander effect by mixing two kinds of cells at different ratio. CONCLUSION: Our data demonstrate that HSV-TK/GCV suicide gene therapy system is effective for treating experimental human pancreatic cancer, which is largely resistant to the common therapies, so the suicide gene therapy system may be a potential treatment approach for pancreatic cancer.

Relationship between telomerase activity and its subunit expression and inhibitory effect of antisense hTR on pancreatic carcinoma.

AIM: To directly investigate the relationship between telomerase activity and its subunit expression and the inhibitory effect of antisense hTR on pancreatic carcinogenesis. METHODS: We examined the telomerase activity and its subunit expression by cell culture, polymerase chain reaction (PCR), PCR-silver staining, PCR-ELISA, DNA sequencing, MTT and flow cytometry methods. RESULTS: PCR-silver staining and PCR-ELISA methods had the same specificity and sensitivity as the TRAP method. Telomerase activity was detected in the extract of the 10(th),20(th) and 30(th) passages of P3 cells,while it was absent in fibroblasts. Furthermore, after the 30th generation, the proliferation period of fibroblast cells was significantly prolonged. Telomerase activity and hTERTmRNA were detected in two pancreatic carcinoma cell lines, but were found to be negative in human fibroblast cells. Telomerase activity and hTERTmRNA were tested in pancreatic carcinoma specimens of 24 cases. The telomerase activity was positive in 21 of the 24 cases (87.5 %), and the hTERTmRNA in 20 cases (83.3 %). In adjacent normal tissues positive rates were both 12.5 %. There was a significant difference between the two groups. This indicated a significant correlation between the expression level of telomerase activity and histologic differentiation, metastasis and advanced clinical stage of pancreatic carcinoma. Our findings showed that the expressions of hTR and TP1mRNA were not correlated with the activity of telomerase but the expression of hTERTmRNA was. After treatment with PS-ODNs, telomerase activity in P(3) cells weakened and the inhibiting effect became stronger with an increase in PS-ODNs concentration. There was a significant difference between different PS-ODN groups (P<0.05). Inhibition of telomerase activity occurred most significant with PS-ODN1. The results of the FCM test of pancreatic cancer P(3) cells showed an increase in the apoptotic rate with increasing PS-ODN1 and PS-ODN2 concentrations. CONCLUSION: The expression of telomerase activity has a significant relationship to carcinogenesis. A strong correlation exists between telomerase activity and hTERTmRNA expression. The up-regulation of hTERTmRNA expression may play a critical role in human carcinogenesis. The expression of telomerase activity and its subunit level in pancreatic carcinoma significantly correlate with the clinical stage of pancreatic carcinoma and hence, may be helpful in its diagnosis and prognosis. The anti-hTR complementary to the template region of hTR is sufficient to inhibit P3 cell telomerase activity and cell proliferation in vitro, and can lead to a profound induction of programmed cell death.

[Inhibition effects of phosphorothioate-modified antisense hTR on the telomerase activity and the growth of P3 cells derived from pancreatic cancer in culture].

This paper is to investigate PS-ODN's (antisense-PS-ODN of hTR,sense-PS-ODN of hTR and random sequence) effects on telomerase activity and proliferation of P3 pancreatic cancer cells,and to find a novel method for gene therapy of pancreatic cancer. The results indicate that the anti-hTR complementary to the template region of hTR is sufficient to inhibit P3 cell telomerase activity and cell proliferation in vitro,and as a result, they can lead to a profound induction of programmed cell death. Telomerase represents an interesting and promising anticancer drug target and anti-telomerase technology may have potential significance in tumor therapy.