BackgroundThe excretory–secretory (ES) antigens of Trichinella spiralis muscle larvae (ML) are the most commonly used diagnostic antigens for trichinellosis. Their main disadvantage for the detection of anti-Trichinella IgG is false-negative results during the early stage of infection. Additionally, there is an obvious window between clinical symptoms and positive serology.MethodsELISA with adult worm (AW) ES antigens was used to detect anti-Trichinella IgG in the sera of experimentally infected mice and patients with trichinellosis. The sensitivity and specificity were compared with ELISAs with AW crude antigens and ML ES antigens.ResultsIn mice infected with 100 ML, anti-Trichinella IgG were first detected by ELISA with the AW ES antigens, crude antigens and ML ES antigens 8, 12 and 12 days post-infection (dpi), respectively. In mice infected with 500 ML, specific antibodies were first detected by ELISA with the three antigen preparations at 10, 8 and 10 dpi, respectively. The sensitivity of the ELISA with the three antigen preparations for the detection of sera from patients with trichinellosis at 35 dpi was 100 %. However, when the patients’ sera were collected at 19 dpi, the sensitivities of the ELISAs with the three antigen preparations were 100 % (20/20), 100 % (20/20) and 75 % (15/20), respectively (P < 0.05). The specificities of the ELISAs with the three antigen preparations were 98.11, 95.60 and 89.31 %, respectively (P < 0.05).ConclusionsThe sensitivity and specificity of the T. spiralis AW ES antigens were superior to those of the AW crude antigens and ML ES antigens. Thus, the AW ES antigens might serve as potential antigens for the early and specific serodiagnosis of trichinellosis.

BackgroundGlutathione-S-transferase (GST) is a widespread multigene family of detoxification enzymes. The vaccination of mice with recombinant GST of 24 kDa from Trichinella spiralis elicited a low immune protection against challenge infection. The objective of this study was to characterize the T. spiralis putative GST gene (TspGST) encoding a 30.8 kDa protein and to evaluate its potential as a candidate antigen for anti-Trichinella vaccine.MethodsThe full-length cDNA sequence of TspGST from T. spiralis muscle larvae (ML) was expressed in E. coli. The enzymatic activity and antigenicity of the rTspGST were identified by spectrophotometry, Western blot, and ELISA. The expression of TspGST at T. spiralis various stages was investigated by RT-PCR and indirect immunofluorescent test (IIFT). Serum level of total IgG, IgG1, and IgG2a antibodies against rTspGST were measured by ELISA. The immune protection produced by vaccination with rTspGST against T. spiralis was evaluated.ResultsThe sequencing results showed that the cDNA of TspGST was 840 bp, and encoded a protein of 279 amino acids, which had a molecular size of 30.8 kDa and a pI of 5.21. Its amino acid sequence shares 37% similarity with TsGST. The rTspGST protein had enzymatic activity of GST. On Western blot and ELISA analysis, the native TspGST protein with 30.8 kDa in crude antigens derived from adult worms (AW), newborn larvae (NBL), infective intestinal larvae (IIL) and ML was recognized by anti-rTspGST sera, but the ML ES antigens could be not recognized by anti-rTspGST sera. Expression of TspGST was found in all of T. spiralis various stages (AW, NBL, ML, and IIL). An immunolocalization analysis identified TspGST in different stages (mainly in cuticles) of the nematode. The mice vaccinated with the rTspGST elicited Th2-predominant immune responses, showed a 34.38% reduction of adult worms and a 43.70% reduction of muscle larvae.ConclusionsImmunization with rTspGST produced a partial immune protection, and the rTspGST could be regarded as a potential candidate target for an anti-Trichinella vaccine.

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The excretory-secretory (ES) antigens from Trichinella spiralis muscle larvae are the most commonly used diagnostic antigens for trichinellosis, but specific IgG antibodies were not detected in early stage of infection. The aim of this study was to identify early diagnostic antigens from ES proteins of intestinal infective larvae (IIL), the first invasive stage of T. spiralis. Six bands (92, 52, 45, 35, 32, and 29 kDa) of IIL ES proteins were recognized by infection sera in Western blotting as early as 10 days post infection. Total of 54 T. spiralis proteins in six bands were identified by shotgun LC-MS/MS, 30 proteins were annotated, and 27 had hydrolase activity. Several proteins (serine protease, putative trypsin, deoxyribonuclease II family protein, etc.) could be considered as the potential early diagnostic antigens for trichinellosis. Our study provides new insights for screening early diagnostic antigens from intestinal worms of T. spiralis.

BackgroundPrevious study showed that Trichinella spiralis proteasome subunit beta type-7 (Tspst) gene is an up-regulated gene in intestinal infective larvae (IIL) compared to muscle larvae (ML), which was screened by using suppression subtractive hybridization (SSH) and confirmed by real-time PCR. Tspst may be related to the larval invasion of intestinal epithelial cells (IECs). The aim of this study was to identify Tspst and to investigate its immune protection against intestinal T. spiralis infection.MethodsThe Tspst gene encoding a 29 kDa protein from T. spiralis infective larvae was cloned, and recombinant Tspst protein (rTspst) was produced in an Escherichia coli expression system. The rTspst was used to immunize BALB/c mice. Anti-rTspst antibodies were used to determine the immunolocolization of Tspst in the parasite. Transcription and expression of Tspst at T. spiralis different developmental stages were observed by RT-PCR and immunofluorescence test (IFT). The in vitro or in vivo immune protection of anti-rTspst serum or rTspst against intestinal T. spiralis infection in BALB/c mice was evaluated.ResultsAnti-rTspst serum recognized the native Tspst protein with 29 kDa in ML crude antigens. Transcription and expression of gene was observed at all T. spiralis different developmental stages (IIL, adult worms, newborn larvae, and ML). An immunolocalization analysis identified Tspst in the cuticle and internal organs of the parasite. An in vitro invasion assay showed that, when anti-rTspst serum, serum of mice infected with T. spiralis or normal mouse serum were added to the medium, the invasion rate of the infective larvae in an IEC monolayer was 25.2%, 11.4%, and 79%, respectively (P < 0.05), indicating that anti-rTspst serum partially prevented the larval invasion of IECs. After a challenge infection with T. spiralis muscle larvae, mice immunized with rTspst conferred a 45.7% reduction in adult worm burden in intestines.ConclusionsIn the present study, Tspst was first identified and characterized. Tspst is an invasion-related protein of T. spiralis IIL and could be considered as a potential vaccine candidate antigen against intestinal T. spiralis infection that merits further study.

The goal of this evaluation was to examine the mechanisms of Shenqi Fuzheng injection (SFI), an extract made from the plants Radix Astragali and Radix Codonopsis, in the process of chemotherapy sensitivity in non-small-cell lung cancer (NSCLC) cells. We investigated the expression of mitofusin-2 (Mfn2), a mitochondrial GTPase that may be related to chemoresistance, and found that Mfn2 expression was lower in human cisplatin-resistant lung carcinoma A549/DDP cells than in cisplatin-susceptible A549 cells. Chemosensitivity to cisplatin was restored in A549/DDP cells following supplementation in conjunction with SFI treatment, the effect of which we evaluated via cell cycle, apoptosis, and cell signaling analysis. We found that the combined use of A549/DDP cells with SFI and cisplatin enhanced cell cycle arrested in the G2/M phase, which was accompanied by upregulation of p53 and p21 protein expression and induced mitochondrial apoptosis in conjunction with the upregulation of Bax and the downregulation of Bcl-2 protein expression. Moreover, cell cycle arrest and mitochondrial apoptosis coincided with the upregulation of Mfn2 expression, which, in turn, was related to the increased mitochondrial membrane permeabilization and elevated reactive oxygen species. In summary, our findings suggest that the effect of SFI in increasing chemotherapy sensitivity in cisplatin resistance of NSCLCs occurs through cell cycle arrest and the initiation of mitochondrial apoptosis involved in the upregulation of Mfn2 expression.

Previous studies have demonstrated that ovariectomy may lead to a reduction in antioxidative biomarkers in the myocardium, thus suggesting that estrogens may serve a protective role in the suppression of oxidative stress. Lycium barbarum polysaccharides (LBP) are a well-known antioxidant Chinese traditional medicine, which appear to have a similar function to estrogens with regards to the regulation of cardiac function. In the present study, 30 Sprague-Dawley rats were randomly divided into the following groups: Sham operation group, ovariectomized (OVX) group, estradiol valerate group, high-dose LBP (LBP-H) group and low-dose LBP (LBP-L) group. All of the rats were provided tap water, estradiol valerate or LBP for 12 weeks. In addition, all rats were ovariectomized, with the exception of rats in the sham operation group, which underwent fat removal only. Reactive oxygen species (ROS), malondialdehyde (MDA), glutathione peroxidase (GSH-px), catalase (CAT) and superoxide dismutase activities were subsequently examined. The protein expression levels of cleaved caspase-9, cleaved caspase-3 and phosphorylated-protein kinase B (p-Akt) were also assessed. The results demonstrated that high-dose LBP decreased the enhanced levels of ROS and MDA in OVX rats, whereas GSH-px and CAT activities were increased in the LBP-H group compared with in OVX rats. Furthermore, the expression levels of cleaved caspase-9 and cleaved caspase-3 were significantly upregulated in the OVX group, whereas high-dose LBP exerted protective effects on OVX rats by decreasing the expression of apoptotic proteins. Conversely, p-Akt expression was decreased in the OVX group and was increased in the LBP-H group. These results indicated that LBP is essentially involved in cardiac protection by inhibiting apoptosis in response to oxidative stress. In addition, improvement of antioxidant status by LBP is associated with the Akt signaling pathway in the myocardium of OVX rats.

A trigonometric polynomial Coons patch analogous to the standard bicubic Coons patch, with two shape parameters, is presented in this work. The proposeded patch not only has the same properites to the standard bicubic Coons patch, but also can be adjusted by altering values of the shape parameters when the interpolation conditions are fixed. Given proper conditions, the proposed patch can accurately represent torus and ellipsoid.