Evaluation of an antigen-capture EIA for the diagnosis of hepatitis E virus infection

An enzyme immunoassay (EIA) has been developed for hepatitis E virus (HEV) antigen (HEV-Ag) detection and marketed in China. This study aimed to evaluate the sensitivity of the assay and assess the value of HEV-Ag detection in the diagnosis of HEV infection in comparison with HEV RNA detection. Using serial dilutions of a genotype 4 HEV strain, significant correlation was found between the EIA (S/CO) and HEV RNA (IU/mL) concentration in the range 10(3.5) to 10(0.5) IU/mL HEV RNA, the Pearson correlation coefficient r approached 0.97. The EIA detection limit was 54.6 IU/mL, compared to 24 IU/mL for HEV RNA using real-time RT-PCR. In clinical samples from hepatitis E patients, the HEV-Ag and HEV RNA positivity rates were 55.6% (65/117) and 60.7% (71/117) in sera and 76.7% (56/73) and 84.9% (62/73) in stools, and the concordance of these two markers was 77.8% in sera and 80.8% in stools. In serum samples, the HEV-Ag positivity rate and the concordance between HEV-Ag and HEV RNA were inversely proportional to the presence of anti-HEV antibody. The presence of anti-HEV IgG could reduce the S/CO of the HEV-Ag EIA. These results reveal a significant correlation between the detection of HEV-Ag and HEV RNA. The sensitivity of the HEV-Ag EIA was lower than real-time RT-PCR but could be higher than conventional nested RT-PCR. Therefore, the detection of HEV-Ag in serum and faeces is valuable for the diagnosis and prognosis of HEV infection in developing regions where real-time RT-PCR is not available.

Prognostic nutritional index predicts survival and correlates with systemic inflammatory response in advanced pancreatic cancer

BACKGROUND

Recent studies have implied a prognostic value of the prognostic nutritional index (PNI) in certain types of human cancers. However, the value of PNI for predicting survival in patients with pancreatic cancer remains unknown. The goal of this study was to investigate the predictive significance of PNI in patients with advanced pancreatic cancer.

METHODS

A total of 321 consecutive patients with pathologically-confirmed locally advanced or metastatic pancreatic ductal adenocarcinoma (PDAC) were retrospectively recruited between January 2011 and August 2013. The patients were divided into a test set (n = 110) and a validation set (n = 211). We evaluated the association between PNI and overall survival (OS). The relationship between PNI and systemic inflammatory response markers, including the neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), and lymphocyte/monocyte ratio (LMR) was also assessed. In addition, the associations between PNI and the TNF-α were analyzed.

RESULTS

Kaplan-Meier analyses showed that a low PNI correlated significantly with a shorter OS in patients with advanced pancreatic cancer (190 days for patients with a low PNI vs. 290 days for patients with a high PNI, log-rank = 12.566, P < 0.001). Multivariate analysis identified PNI as an independent prognostic factor for OS (hazard ratio [HR]: 0.627, 95% confidence interval [CI]: 0.453-0.868, P = 0.003). PNI also correlated positively with NLR and PLR and negatively with LMR. Additionally, patients with a low PNI exhibited high levels of TNF-α.

CONCLUSIONS

Our results confirm that PNI is associated with the systemic inflammatory response and can be used to predict survival in advanced pancreatic cancer.

The left ventricular assist effect and biocompatibility study of a novel para-aortic counterpulsation device

OBJECTIVE

To evaluate the hemodynamic characteristics and biocompatibility of a new para-aortic counterpulsation device in animal experiment studies.

MATERIALS AND METHODS

Para-aortic counterpulsation device (PACD), a monoport device, consists of a blood chamber anastomosed to the descending aorta by means of a valveless graft and an air chamber connected to IABP machine. Hemodynamic parameters during the PACD-assisted beats were compared with those during the unassist beats. Acute heart failure was induced in all animals, and the hemodynamic effects of PACD were then reassessed.

RESULTS

We successfully induced heart failure in all cases, in conditions of which cardiac output (CO) and MAP decreased 17.6% and 27.7% respectively, and PCWP increased 57.7%. Hemodynamic indexes, cerebral and heart perfusion improved significantly after PACD assisting. PACD activation increased significantly CO and MAP 6.29% and 2.04% respectively. Both of SAP and DAP decreased significantly from 85.00 to 81.88 mmHg and 59.63 to 54.63 respectively, at the same time, MADP increased 19.4%, after PACD assist. The value of MDLMF, LMF and CSF was increased by 14.0%, 13.8% and 11.6% respectively. LCAF increased by 11.23%, after PACD assist. The PFH increased significantly in the first six hours. There was no statistically significant difference in the last two hours. When the acute animal experiments were completed, there were no infarct ischemic, thrombosis change in organs by Gross and histologic observation.

CONCLUSIONS

PACD with good biological compatibility significantly reduced the left ventricular afterload, increased diastolic arterial pressure and myocardial perfusion, improved heart function and cerebral perfusion.

Intracerebroventricular transplanted bone marrow stem cells survive and migrate into the brain of rats with Parkinson's disease

In this study, 6-hydroxydopamine was stereotaxically injected into the right substantia nigra compact and ventral tegmental area of rats to establish Parkinson's disease models. The rats then received a transplantation of bone marrow stromal cells that were previously isolated, cultured and labeled with 5-bromo-2'-deoxyuridine in vitro. Transplantation of the bone marrow stromal cells significantly decreased apomorphine-induced rotation time and the escape latency in the Morris water maze test as compared with rats with untreated Parkinson's disease. Immunohistochemical staining showed that, 5-bromo-2'-deoxyuridine-immunoreactive cells were present in the lateral ventricular wall and the choroid plexus 1 day after transplantation. These immunoreactive cells migrated to the surrounding areas of the lateral cerebral ventricle along the corpus callosum. The results indicated that bone marrow stromal cells could migrate to tissues surround the cerebral ventricle via the cerebrospinal fluid circulation and fuse with cells in the brain, thus altering the phenotype of cells or forming neuron-like cells or astrocytes capable of expressing neuron-specific proteins. Taken together, the present findings indicate that bone marrow stromal cells transplanted intracerebroventricularly could survive, migrate and significantly improve the rotational behavior and cognitive function of rats with experimentally induced Parkinson's disease.

Clinical implications of systemic inflammatory response markers as independent prognostic factors for advanced pancreatic cancer

BACKGROUND

Cancer-associated inflammation is a key molecular feature of pancreatic ductal adenocarcinoma. In this study, we systematically evaluated the prognostic relevance of systemic inflammatory response (SIR) markers in patients with advanced pancreatic cancer.

METHODS

A total of 321 consecutive patients with pathologically-confirmed locally advanced or metastatic pancreatic adenocarcinoma were retrospectively recruited. The patients were divided into a test set (n = 110) and a validation set (n = 211). The associations between overall survival (OS) and clinically available SIR markers including white blood cell (WBC) count, absolute neutrophil count, absolute lymphocyte count, absolute monocyte count, platelet count, neutrophil-lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR) and lymphocyte/monocyte ratio (LMR) were analyzed using Kaplan-Meier curves and multivariate Cox proportional models.

RESULTS

High WBC count, neutrophil count, monocyte count, NLR, PLR and low LMR were significantly associated with decreased OS in the test set. Using the validation set for confirmation, we found also in multivariate analysis an independent value of WBC count (hazard ratio (HR): 2.176, 95% confidence interval (CI): 1.560-3.035, P < 0.001), neutrophil count (HR: 2.807, 95% CI: 2.000-3.940, P < 0.001), monocyte count (HR: 1.848, 95% CI: 1.315-2.598, P < 0.001), NLR (HR: 2.204, 95% CI: 1.590-3.055, P < 0.001), PLR (HR: 1.537, 95% CI: 1.114-2.122, P = 0.009) and LMR (HR: 0.569, 95% CI: 0.412-0.784, P = 0.001) for OS in patients with advanced pancreatic cancer.

CONCLUSIONS

Our study confirmed that SIR markers can be used to determine optimal therapeutic strategies for individual patients and to predict pancreatic cancer prognosis.

A Model-Free Machine Learning Method for Risk Classification and Survival Probability Prediction

Risk classification and survival probability prediction are two major goals in survival data analysis since they play an important role in patients' risk stratification, long-term diagnosis, and treatment selection. In this article, we propose a new model-free machine learning framework for risk classification and survival probability prediction based on weighted support vector machines. The new procedure does not require any specific parametric or semiparametric model assumption on data, and is therefore capable of capturing nonlinear covariate effects. We use numerous simulation examples to demonstrate finite sample performance of the proposed method under various settings. Applications to a glioma tumor data and a breast cancer gene expression survival data are shown to illustrate the new methodology in real data analysis.

Detection of enterovirus 71 gene from clinical specimens by reverse-transcription loop-mediated isothermal amplification

PURPOSE

The objective of this study was to develop a sensitive, specific and rapid approach to diagnose hand foot and mouth disease (HFMD) for an early treatment by using loop-mediated isothermal amplification (LAMP) technique.

MATERIALS AND METHODS

A reverse-transcription loop-mediated isothermal amplification (RT-LAMP) for detecting EV71 virus was developed, the specificity and sensitivity of RT-LAMP was tested, and the clinical specimens was assayed by the RT-LAMP comparing with conventional reverse-transcription polymerase chain reaction (RT-PCR) and real-time PCR.

RESULTS

A total of 116 clinical specimens from the suspected HFMD individual were detected with the RT-LAMP. The detection rate for EV71 was 56.89% by RT-LAMP, 41.38% by real-time PCR and 34.48% by RT-PCR. The minimum detection limit of RT-LAMP was 0.01 PFU, both of RT-PCR and real-time PCR was 0.1PFU. Non-cross-reactive amplification with other enteroviruses was detected in the survey reports.

CONCLUSIONS

The effectiveness of RT-LAMP is higher than RT-PCR and real-time PCR. The protocol is easy to operate and time saving. It was not an expensive instrument, which was needed; it is an applicable method for rapid diagnosis of the disease, especially in resource-poor countries or in developing countries.

On optimal treatment regimes selection for mean survival time

In clinical studies with time-to-event as a primary endpoint, one main interest is to find the best treatment strategy to maximize patients' mean survival time. Due to patient's heterogeneity in response to treatments, great efforts have been devoted to developing optimal treatment regimes by integrating individuals' clinical and genetic information. A main challenge arises in the selection of important variables that can help to build reliable and interpretable optimal treatment regimes as the dimension of predictors may be high. In this paper, we propose a robust loss-based estimation framework that can be easily coupled with shrinkage penalties for both estimation of optimal treatment regimes and variable selection. The asymptotic properties of the proposed estimators are studied. Moreover, a model-free estimator of restricted mean survival time under the derived optimal treatment regime is developed, and its asymptotic property is studied. Simulations are conducted to assess the empirical performance of the proposed method for parameter estimation, variable selection, and optimal treatment decision. An application to an AIDS clinical trial data set is given to illustrate the method.

Age-related alterations in the metabolic profile in the hippocampus of the senescence-accelerated mouse prone 8: a spontaneous Alzheimer's disease mouse model

Alzheimer's disease (AD), the most common age-dependent neurodegenerative disorder, produces a progressive decline in cognitive function. The metabolic mechanism of AD has emerged in recent years. In this study, we used multivariate analyses of gas chromatography-mass spectrometry measurements to determine that learning and retention-related metabolic profiles are altered during aging in the hippocampus of the senescence-accelerated mouse prone 8 (SAMP8). Alterations in 17 metabolites were detected in mature and aged mice compared to young mice (13 decreased and 4 increased metabolites), including metabolites related to dysfunctional lipid metabolism (significantly increased cholesterol, oleic acid, and phosphoglyceride levels), decreased amino acid (alanine, serine, glycine, aspartic acid, glutamate, and gamma-aminobutyric acid), and energy-related metabolite levels (malic acid, butanedioic acid, fumaric acid, and citric acid), and other altered metabolites (increased N-acetyl-aspartic acid and decreased pyroglutamic acid, urea, and lactic acid) in the hippocampus. All of these alterations indicated that the metabolic mechanisms of age-related cognitive impairment in SAMP8 mice were related to multiple pathways and networks. Lipid metabolism, especially cholesterol metabolism, appears to play a distinct role in the hippocampus in AD.

The non-aggregated aggrecan in the human intervertebral disc can arise by a non-proteolytic mechanism

Analysis of both the aggregated and non-aggregated fractions of aggrecan isolated from adult human intervertebral disc using immunoblotting with antibodies specific for the different domains constituting the aggrecan core protein or atomic force microscopy revealed that many components contained the G1 domain. However, little of the disc aggrecan was able to reform aggregates with hyaluronan, as determined by gel filtration chromatography, suggesting that the G1 domains had been rendered non-functional. Since previous studies have shown that disc aggrecan undergoes non-enzymatic glycation with age, the functional effect of such modification was investigated in vitro using bovine aggrecan isolated from young animals. Incubation of monomeric aggrecan with ribose to induce glycation rendered it unable to form complexes with hyaluronan stable to agarose gel electrophoresis or gel filtration chromatography. Similarly, extended treatment of intact proteoglycan aggregate with ribose resulted in destabilisation of the complex with separation of the aggrecan from the hyaluronan. Although it is clear that proteolysis occurs in the intervertebral disc and gives rise to some non-aggregating molecules, a different mechanism is required to explain the presence of many non-aggregating molecules bearing the G1 domain. The products of non-enzymatic glycation of the globular domains of aggrecan would account for this phenomenon and explain why some of the non-aggregating molecules are still large proteoglycans. While such molecules may be retained in the nucleus pulposus, they may be able to diffuse within it, reducing the ability of the tissue to resist compression under asymmetric loading such as bending and ultimately contributing to disc degeneration.

Inhibitory effect of dexamethasone on Lewis mice lung cancer cells

Recent studies have found that glucocorticoids are closely associated with oncogenesis and the development of many types of tumors. The aim of this study was to observe the effect of dexamethasone on the growth and angiogenesis of transplanted Lewis lung carcinoma in mice. Lewis lung carcinoma cells were inoculated subcutaneously into the right axilla of C57BL/6 mice, and the mice were randomly divided into 3 groups: the control group, cisplatin group, and dexamethasone group. From day 7 after inoculation, all the mice were given different treatments for 10 days, and changes in xenograft tumor volumes were monitored. All mice were sacrificed on day 17, and the tumors were obtained and weighed and the tumor inhibitory rate was calculated. The expression levels of hypoxia inducible factor 1α (HIF-1α) and vascular endothelial growth factor (VEGF), as well as the microvessel density (MVD) in the tumor mass, were measured by immunohistochemistry. Tumor growth was suppressed in the cisplatin group and dexamethasone group. The weights of tumors were markedly decreased in the cisplatin group and dexamethasone group compared with the control group (P < 0.05). The expression levels of HIF-1α and VEGF and the MVD were significantly lower in the cisplatin group and dexamethasone group than in the control group (P < 0.05). However, these levels were not significantly different between the cisplatin group and dexamethasone group (P > 0.05). Dexamethasone can effectively inhibit the growth and angiogenesis of Lewis lung carcinoma by inhibiting the expression of HIF-1α and VEGF.

Safety and immunogenicity of an oral DNA vaccine encoding Sip of Streptococcus agalactiae from Nile tilapia Oreochromis niloticus delivered by live attenuated Salmonella typhimurium

Attenuated Salmonella typhimurium SL7207 was used as a carrier for a reconstructed DNA vaccine against Streptococcus agalactiae. A 1.02 kb DNA fragment, encoding for a portion of the surface immunogenic protein (Sip) of S. agalactiae was inserted into pVAX1. The recombinant plasmid pVAX1-sip was transfected in EPC cells to detect the transient expression by an indirect immunofluorescence assay, together with Western blot analysis. The pVAX1-sip was transformed by electroporation into SL7207. The stability of pVAX1-sip into Salmonella was over 90% after 50 generations with antibiotic selection in vitro while remained stable over 80% during 35 generations under antibiotic-free conditions. The LD50 of SL/pVAX1-sip was 1.7 × 10(11) CFU/fish by intragastric administration which indicated a quite low virulence. Tilapias were inoculated orally at 10(8) CFU/fish, the recombinant bacteria were found present in intestinal tract, spleens and livers and eventually eliminated from the tissues 4 weeks after immunization. Fish immunized at 10(7), 10(8) and 10(9) CFU/fish with different immunization times caused various levels of serum antibody and an effective protection against lethal challenge with the wild-type strain S. agalactiae. Integration studies showed that the pVAX1-sip did not integrate with tilapia chromosomes. The DNA vaccine SL/pVAX1-sip was proved to be safe and effective in protecting tilapias against S. agalactiae infection.

Safe and efficient local gene delivery into skeletal muscle via a combination of Pluronic L64 and modified electrotransfer

Efficient DNA electrotransfer into muscles can be achieved by combining two types of electronic pulses sequentially: short high-voltage (HV) pulse for the cell electropermeabilization and long low-voltage (LV) pulse for the DNA electrophoresis into cells. However, the voltages currently applied can still induce histological and functional damages to tissues. Pluronic L64 has been considered as a molecule possessing cell membrane-disturbing ability. For these reasons, we hope that L64 can be used as a substitute for the HV pulse in cell membrane permeabilization, and a safe LV pulse may still keep the ability to drive plasmid DNA across the permeabilized membrane. In this work, we optimized the electrotransfer parameters to establish a safe and efficient procedure using a clinically applied instrument, and found out that the critical condition for a successful combination of electrotransfer with L64 was that the injection of plasmid/L64 mixture should be applied 1 h before the electrotransfer. In addition, we revealed that the combined procedure could not efficiently transfer plasmid into solid tumor because the uncompressed plasmid may rapidly permeate the leaky tumor vessels and flow away. Altogether, the results demonstrate that the combined procedure has the potential for plasmid-based gene therapy through safe and efficient local gene delivery into skeletal muscles.

Synthesis and photovoltaic properties of new donor–acceptor (D–A) copolymers based on benzo[1,2-b:3,4-b′:6,5-b′′] trithiophene donor and different acceptor units (P1 and P2)

A power conversion efficiency of about 5.26% has been achieved for the device based onP1:PC71BM.

The pathology of selenium deficiency in Cyprinus carpio L

Selenium is essential for the normal life processes, and all animals, including fish, need this inorganic element. In order to research the pathology of selenium deficiency in common carp, Cyprinus carpio L., 360 juvenile carp were allocated to three treatments. Each treatment containing 120 fish was randomly divided into four groups, fed with purified diets containing selenium at 0, 0.15, 0.30 and 0.45 mg kg(-1). The results indicated that the morbidity and mortality rates of the test groups were negatively correlated with the level of selenium in the diets. The morbidity and mortality rates were, respectively, 46.7%, 33.3%, 13.3%, 0 and 26.7% 16.7%, 6.7%, 0. The affected fish exhibited pathological changes, such as 'thin back disease' and lordosis. Histologically, there was no abnormality observed in muscles, liver and pancreas. Ultrastructurally, there was swelling of the mitochondria of the cardiac muscle cells, the liver cells and renal tubular epithelial cells, with disintegration and lysis of the cristae of the mitochondria which vesiculated. Serum glutamic oxaloacetic transaminase and glutamic pyruvic transaminase levels were increased and the activity of the serum glutathione peroxidase and the serum superoxide dismutase was decreased; in contrast, the serum malonaldehyde concentration was increased.

Analysis of the factor XI variant Arg184Gly suggests a structural basis for factor IX binding to factor XIa

BACKGROUND

A patient with factor XI (FXI) deficiency was reported with an Arg184Gly substitution in the FXI A3 domain. The A3 domain contains an exosite required for binding of FIX to activated FXI (FXIa).

OBJECTIVE

To test the effects of the Arg184Gly substitution on FIX activation, and to characterize the FIX-binding site on FXIa.

METHODS

Recombinant FXIa and FIX variants were used to identify residues involved in FIX activation by FXIa. Analysis of the FXI structure was used to identify potential FIX-binding sites.

RESULTS

The Km for FIX activation by FXIa-Gly184 was approximately three-fold higher than for FXIa, suggesting that Arg184 is part of the exosite. Arg184 and the adjacent residues, Ile183 and Asp185, contribute to charged and hydrophobic areas that are not present in the FXI homolog prekallikrein (PK). Replacing residues 183-185 with alanine abolished exosite activity, similarly to replacement of the entire A3 domain with the A3 domain from PK (FXIa/PKA3). Reintroducing FXI residues 183-185 into FXIa/PKA3 partially restored the exosite, and replacing residues 183-185 and 260-264 completely restored exosite function. FIX in which the Ω-loop (residues 4-11) was replaced with the FVII Ω-loop was activated poorly by FXIa, suggesting that the FIX Ω-loop binds to FXIa.

CONCLUSIONS

The results support a model in which the Ω-loop of FIX binds to an area on FXIa composed of residues from the N-terminus and C-terminus of the A3 domain. These residues are buried in zymogen FXI, and must be exposed upon conversion to FXIa to permit FIX binding.

A 90-day subchronic toxicity study of neem oil, a Azadirachta indica oil, in mice

To determine the no-observed-adverse-effect level (NOAEL) of exposure and target organs of neem oil for establishing safety criteria for human exposure, the subchronic toxicity study with neem oil in mice was evaluated. The mice (10 per sex for each dose) was orally administered with neem oil with the doses of 0 (to serve as a control), 177, 533 and 1600 mg/kg/day for 90 days. After the treatment period, observation of reversibility or persistence of any toxic effects, mice were continuously fed without treatment for the following 30 days. During the two test periods, the serum biochemistry, organ weight and histopathology were examined. The results showed that the serum biochemistry and organ coefficient in experimental groups had no statistical difference compared with those of the control group. At the 90th day, the histopathological examinations showed that the 1600 mg/kg/day dose of neem oil had varying degrees of damage on each organ except heart, uterus and ovarian. After 30-day recovery, the degree of lesions to the tissues was lessened or even restored. The NOAEL of neem oil was 177 mg/kg/day for mice and the target organs of neem oil were determined to be testicle, liver and kidneys.