Identification of hepatic progenitor cells in the canine fetal liver

The liver plays essential roles in human and animal organisms, such as the storage, release, metabolism, and elimination of various endogenous or exogenous substances. Although its vital importance, few treatments are yet available when a hepatic failure occurs, and hence, the use of stem cells has arisen as a possible solution for both human and veterinary medicines. Previous studies have shown the existence of hepatic progenitor cells in human fetuses that were positive for EpCAM and NCAM. There is limited evidence, however, further identification and characterization of these cells in other species. Considering the similarity between dogs and humans regarding physiology, and also the increasing importance of developing new treatments for both veterinary and translational medicine, this study attempted to identify hepatic progenitor cells in canine fetal liver. For that, livers from canine fetuses were collected, cells were isolated by enzymatic digestion and cultured. Cells were characterized regarding morphology and expression of EpCAM, NCAM, Nestin, and Thy-1/CD90 markers. Our results suggest that it is possible to identify hepatic progenitor cells in the canine fetal liver; however, for therapeutic use, further techniques for cellular isolation and culture are necessary to obtain enriched populations of hepatic progenitors from the canine fetal liver.

Mesenchymal-like stem cells in canine ovary show high differentiation potential

OBJECTIVES

Recent studies have reported the existence of stem cells in ovarian tissue that show enhanced proliferative and differentiation potential compared to other adult tissues. Based on this evidence, we hypothesized that ovarian tissue contained mesenchymal-like stem cells (MSC) that could be isolated using a novel rapid plastic adhesion technique.

MATERIALS AND METHODS

We established MSC lines derived from ovarian and adipose tissue based on their ability to rapidly adhere to plastic culture dishes in the first 3 hours after plating and studied their potentiality in terms of molecular markers and differentiation capacity.

RESULTS

Morphological and kinetic properties of in vitro cultured ovarian MSC were similar to adipose-derived MSC, and both reached senescence after similar passage numbers. Ovarian-derived MSC expressed mesenchymal (CD90 and CD44) but not haematopoietic markers (CD34 and CD45), indicating similarity to adipose-derived MSC. Moreover, ovarian-derived MSC expressed NANOG, TERT, SOX2, OCT4 and showed extensive capacity to differentiate not only into adipogenic, osteogenic and chondrogenic tissue but also towards neurogenic and endodermal lineages and even precursors of primordial germ cells.

CONCLUSION

These results show for the first time the derivation of ovarian cells with the molecular properties of MSC as well as wide differentiation potential. Canine ovarian tissue is accessible, expandable, multipotent and has high plasticity, holding promise for applications in regenerative medicine.

Ageing studies of TPB in noble gas detectors for dark matter and neutrinoless ββ decay searches

Noble gases (Xe, Ar, Kr) are very attractive as detector media in Dark Matter search and neutrinoless double-beta decay experiments. However, the detection of their scintillation light (in the VUV spectral region) requires shifting the VUV light to visible light, where standard photosensors are more efficient. Tetraphenyl butadiene (TPB) is widely used as wavelength shifter, absorbing the VUV light and re-emitting in the blue region (~430nm). TPB is an organic molecule that may degrade due to exposure to environmental agents and also to ultraviolet light. In this work, we present TPB ageing studies due to exposure to VUV light, aiming at quantifying the reduction of the absolute fluorescence yield of TPB coatings of several thicknesses (130nm, 260nm, 390nm, 1600nm), exposed to various doses of VUV light at 170nm (similar to the Xe scintillation). In our setup, the VUV light is produced from a vacuum monochromator coupled to a deuterium lamp. The VUV exposure in our setup is compared to the exposure obtained in the electroluminescent gaseous Xe TPC of the NEXT-100 experiment for neutrinoless double-beta decay search.

Developing a methodology to predict PM10 concentrations in urban areas using generalized linear models

A methodology to predict PM10 concentrations in urban outdoor environments is developed based on the generalized linear models (GLMs). The methodology is based on the relationship developed between atmospheric concentrations of air pollutants (i.e. CO, NO2, NOx, VOCs, SO2) and meteorological variables (i.e. ambient temperature, relative humidity (RH) and wind speed) for a city (Barreiro) of Portugal. The model uses air pollution and meteorological data from the Portuguese monitoring air quality station networks. The developed GLM considers PM10 concentrations as a dependent variable, and both the gaseous pollutants and meteorological variables as explanatory independent variables. A logarithmic link function was considered with a Poisson probability distribution. Particular attention was given to cases with air temperatures both below and above 25°C. The best performance for modelled results against the measured data was achieved for the model with values of air temperature above 25°C compared with the model considering all ranges of air temperatures and with the model considering only temperature below 25°C. The model was also tested with similar data from another Portuguese city, Oporto, and results found to behave similarly. It is concluded that this model and the methodology could be adopted for other cities to predict PM10 concentrations when these data are not available by measurements from air quality monitoring stations or other acquisition means.

Kinetics data from bovine sex-specific embryo development from three different bulls

Here we present kinetics data from bovine sex-specific embryo development. Embryos were originated using sex-sorted semen from three different Nelore bulls, and semen from the same batch was used for X-and Y-chromosome spermatozoa sorting. Data was obtained for six time points (24, 48, 96, 120, and 144 h.p.i.). Analyses for each bull׳s embryos (1, 2 and 3) is presented for female and male groups separately. Also, grouped data analysis, considering bull and sex interaction, is shown. For further interpretation and discussion, see "Cell death is involved in sexual dimorphism during preimplantation development" (Oliveira et al., 2015 [1]).

Herbal tea extracts inhibit Cytochrome P450 3A4 in vitro

OBJECTIVES

Ciclosporin and sirolimus, two immunosuppressive agents with narrow therapeutic windows, are mainly metabolized by Cytochrome 3A4 (CYP3A4). A clinical case of toxic blood levels of these drugs after the consumption of a '24-flavours' tea was reported. This study aims to identify the causative ingredients of the 24-flavour herbal tea in the inhibition of CYP3A4 metabolism.

METHODS

Two commercially available 24-flavour tea products purchased in Hong Kong and the six plant constituents were tested for their CYP3A4 inhibitory effects utilizing an in-vitro fluorometric assay.

KEY FINDINGS

Of the commercially available teas available in Hong Kong, the most potent inhibitory effect was observed with the tea consumed in the initial clinical case. Of the six universal constituents, chrysanthemum exhibited the greatest inhibitory effect, with an IC50 of 95.7 μg/ml. Dandelion, liquorice and bishop's weed have IC50 of 140.6, 148.4 and 185.5 μg/ml, respectively. Field mint and Japanese honeysuckle have weaker inhibitory effect on CYP3A4 with IC50 of 1153.3 and 1466.3 μg/ml.

CONCLUSIONS

This study confirms the possible implication of herbal tea constituents in the inhibition of ciclosporin and sirolimus' CYP3A4 metabolism. Combined usage of herbal teas with drug should be closely monitored.

Pre-existing cross-reactive antibodies to avian influenza H5N1 and 2009 pandemic H1N1 in US military personnel

We studied cross-reactive antibodies against avian influenza H5N1 and 2009 pandemic (p) H1N1 in 200 serum samples from US military personnel collected before the H1N1 pandemic. Assays used to measure antibodies against viral proteins involved in protection included a hemagglutination inhibition (HI) assay and a neuraminidase inhibition (NI) assay. Viral neutralization by antibodies against avian influenza H5N1 and 2009 pH1N1 was assessed by influenza (H5) pseudotyped lentiviral particle-based and H1N1 microneutralization assays. Some US military personnel had cross-neutralizing antibodies against H5N1 (14%) and 2009 pH1N1 (16.5%). The odds of having cross-neutralizing antibodies against 2009 pH1N1 were 4.4 times higher in subjects receiving more than five inactivated whole influenza virus vaccinations than those subjects with no record of vaccination. Although unclear if the result of prior vaccination or disease exposure, these pre-existing antibodies may prevent or reduce disease severity.

Investigation of the binding and cleavage characteristics of N1 neuraminidases from avian, seasonal, and pandemic influenza viruses using saturation transfer difference nuclear magnetic resonance

Objectives

The main function of influenza neuraminidase (NA) involves enzymatic cleavage of sialic acid from the surface of host cells resulting in the release of the newly produced virions from infected cells, as well as aiding the movement of virions through sialylated mucus present in the respiratory tract. However, there has previously been little information on the binding affinity of different forms of sialylated glycan with NA. Our objectives were then to investigate both sialic acid binding and cleavage of neuraminidase at an atomic resolution level.

Design

Nuclear magnetic resonance (NMR) spectroscopy was used to investigate pH and temperature effects on binding and cleavage as well as to interrogate the selectivity of human-like or avian-like receptors for influenza neuraminidase N1 derived from a range of different influenza virus strains including human seasonal H1N1, H1N1pdm09 and avian H5N1.

Results

We demonstrated that an acidic pH and physiological temperature are required for efficient NA enzymatic activity; however a change in the pH had a minimum effect on the NA-sialic acid binding affinity. Our data comparing α-2,3- and α-2,6-sialyllactose indicated that the variation in neuraminidase activity on different ligands correlated with a change in binding affinity. Epitope mapping of the sialylglycans interacting with NAs from different viral origin showed different binding profiles suggesting that different binding conformations were adopted.

Conclusions

The data presented in this study demonstrated that physicochemical conditions (pH in particular) could affect the NA enzymatic activity with minor effect on ligand binding. NA cleavage specificity seemed to be associated with a difference in binding affinity to different ligands, suggesting a relationship between the two events. These findings have implications regarding the replication cycle of influenza infection in the host where different sialidase activities would influence penetration through the respiratory mucin barrier and the release of the newly generated virus from the infected cells.

Identification of a novel sulfonamide non-nucleoside reverse transcriptase inhibitor by a phenotypic HIV-1 full replication assay

Classical target-based, high-throughput screening has been useful for the identification of inhibitors for known molecular mechanisms involved in the HIV life cycle. In this study, the development of a cell-based assay that uses a phenotypic drug discovery approach based on automated high-content screening is described. Using this screening approach, the antiviral activity of 26,500 small molecules from a relevant chemical scaffold library was evaluated. Among the selected hits, one sulfonamide compound showed strong anti-HIV activity against wild-type and clinically relevant multidrug resistant HIV strains. The biochemical inhibition, point resistance mutations and the activity of structural analogs allowed us to understand the mode of action and propose a binding model for this compound with HIV-1 reverse transcriptase.

Macimorelin (AEZS-130)-stimulated growth hormone (GH) test: validation of a novel oral stimulation test for the diagnosis of adult GH deficiency

CONTEXT

In the absence of panhypopituitarism and low serum IGF-I levels, the diagnosis of adult GH deficiency (AGHD) requires confirmation with a GH stimulation test. Macimorelin is a novel, orally active ghrelin mimetic that stimulates GH secretion.

OBJECTIVE

The objective of the study was to determine the diagnostic efficacy and safety of macimorelin in AGHD.

DESIGN

This was a multicenter open-label study comparing the diagnostic accuracy of oral macimorelin with that of arginine+GHRH in AGHD patients and healthy, matched controls. After 43 AGHD patients and 10 controls were tested, the GHRH analog Geref Diagnostic [GHRH(1-29)NH2] became unavailable in the United States. The study was completed by testing 10 additional AGHD patients and 38 controls with macimorelin alone.

MAIN OUTCOME MEASURE

Peak GH area under the receiver operating characteristic curve after macimorelin was measured.

RESULTS

Fifty AGHD subjects and 48 controls were evaluated. Peak GH levels in AGHD patients and controls after macimorelin were 2.36 ± 5.69 and 17.71 ± 19.11 ng/mL, respectively (P < .0001). With macimorelin, the receiver operating characteristic analysis yielded an optimal GH cut point of 2.7 ng/mL, with 82% sensitivity, 92% specificity, and 13% misclassification rate. For subjects receiving both tests, macimorelin showed discrimination comparable with arginine+GHRH (area under the receiver operating characteristic curve 0.99 vs 0.94, respectively, P = .29). Obesity (body mass index > 30 kg/m(2)) was present in 58% of subjects, and peak GH levels were inversely associated with body mass index in controls (r = -0.37, P = .01). Using the separate cut points of 6.8 ng/mL for nonobese and 2.7 for obese subjects reduced the misclassification rate to 11%. Only 1 drug-related serious adverse event, an asymptomatic QT interval prolongation on the electrocardiogram, was reported.

CONCLUSION

Oral macimorelin is safe, convenient, and effective in diagnosing AGHD with accuracy comparable with the arginine+GHRH test.

Development of a multiplex phenotypic cell-based high throughput screening assay to identify novel hepatitis C virus antivirals

Hepatitis C virus (HCV) infection is a global health concern with chronic liver damage threatening 3% of the world's population. To date, the standard of care is a combination of pegylated interferon-alpha with ribavirin, and recently two direct acting antivirals have entered the clinics. However, because of side effects, drug resistance and viral genotype-specific differences in efficacy current and potentially also future therapies have their limitations. Here, we describe the development of a phenotypic high-throughput assay to identify new cross-genotype inhibitors with novel mechanism of action, by combining a genotype (gt) 1 replicon with the infectious HCV gt2 cell culture system. To develop this phenotypic multiplex assay, HCV reporter cells expressing RFP-NLS-IPS and gt1b replicon cells expressing NS5A-GFP were co-plated and treated with compounds followed by inoculation with gt2a HCV. At 72h post treatment, RFP translocation as a marker for HCV infection and GFP fluorescence intensity as a marker for gt1 RNA replication were measured. Additionally, the total cell number, which serves as an indicator of cytotoxicity, was determined. This phenotypic strategy supports multi-parameter data acquisition from a single well to access cross-genotypic activity, provides an indication of the stage of the viral life cycle targeted, and also assesses compound cytotoxicity. Taken together, this multiplex phenotypic platform facilitates the identification of novel compounds for drug development and chemical probes for continuing efforts to understand the HCV life cycle.

PP124. Trofoblastic invasion: The role of subunits STAT1 and STAT3

INTRODUCTION

The trophoblastic migration/invasion are controlled by cytokines and growth factors that use intracellular pathways of signal to promote the regulation of gene expression, proliferation, cells differentiation, angiogenesis and embryonic development. The most important mediator of cytokine in trophoblastic invasion is the Janus-Kinase/signal transducer and activator of transcription (JAK/STAT). STATs are amino acids, compounds of 700-850 variable long-chain with isoforms α and β and molecular weight between 83-113kDa. The role of these factors in the pregnancy set up may contribute to adopt interventions that could contribute to prophylaxis and/or treatment of abnormalities in the course of gestation when installed early.

OBJECTIVES

Search on database the role of STAT in the process of trophoblastic invasion with emphasis on subunits STAT1 and STAT3.

METHODS

This is a review performed on PubMed database. Have been included Studies found from 1992 (the year of discovery of STATs) until July 2011, without language restriction. The descriptors were: "Signal transducers and activators of transcription "and" Trophoblast". In the end we excluded bibliographical review.

RESULTS

Five of the six selected papers studied the role of STAT3 in the physiology of the trophoblastc invasion process. One of them, indirectly by selection process of lactobacilli of vaginal flora endogenous, during change of vaginal pH on pregnancy, altering the release of greater or lesser number of Interleukin-10 which modulates the activation JAK/STAT. Among them, one of the study refers to involvement of STAT1 in the immunomodulation of interface fetus-mother.

CONCLUSION

STAT3 is directly involved in the process of trophoblast invasion either in its endometrium adherence to, angiogenesis, invasion and regulation of invasion. And STAT1 is involved in immunomodulation through its suppression by trophoblast STAT utron. Several soluble factors that are generally present in the decidua, especially hepatocyte growth factor, granulocyte macrophagocytic-colony stimulating factors, interleukin-6, interleukin-11 and inhibition leukemia factor , which have been described by using the JAK-STAT activating STAT1 and STAT3 for intracellular signaling and from this process may influence the invasion trophoblast.

PP176. SFLT-1: A possibility of precocious diagnosis of preeclampsia

INTRODUCTION

Preeclampsia (PE) affects 5-8% of all pregnant women and can trigger a severe gestational hypertension framework and eventually develop into eclampsia and HELLP syndrome. Anticipating the damage would be important in order to establish procedures that can reduce adverse outcomes. For this reason, many researches are undertaken to identify ways to make a diagnosis of preeclampsia as early as possible. It has been highlighted in literature the study: the sFlt1 (soluble fms-like tyrosine kinase-1) has been implicated in the precocious diagnosis of pre eclampsia. The sFlt1 is an anti-angiogenic factor produced in response to oxidative stress derived from the deleterious effects of pre-eclampsia.

OBJECTIVES

The objective of the study was to evaluate the role of Soluble fms-like tyrosine kinase-1 in the diagnosis of preeclampsia.

METHODS

This is a review conducted in the database PubMed and Lilacs. For this purpose, we used the following MeSH, "Vascular Endothelial Growth Factor Receptor-1" OR "FLT1 protein, human" AND "Pre-Eclampsia/diagnosis" in PubMed and "Pre-eclampsia" AND "SFLT1A" in Lilacs, resulting in 84 papers. After reading the abstracts of these studies, we selected the articles analyzed taking into consideration the criteria for inclusion and exclusion. We excluded publications that were not in the period under study (2008 to July 2011) and by study design. Including only case-control, cohort and prospective observational. For a critical analysis of the material, we used the following indicators: researcher, years, central theme, participants, study design and primary outcome.

RESULTS

The final results of this study were composed of seven articles and are shown for each target outcome. These vary according to gestational age at which PE is installed and the marker studied (sFlt1 alone or its relation to PlGF - sFlt1/PIGF). Six studies showed greater levels of sFlt1 for the preeclampsia groups when compared to the control group. Significantly differences in antiangiogenic factors seric levels were not found among preeclamptic and eclamptic patients. When associated with another factor, like PIGF, a greater efficacy in the diagnosis of early preeclampsia is shown. Of the studies analyzed, only one (Lynch et al) showed no significant difference between the values of sFlt-1 in groups of early PE, late PE and control for gestational ages between 10 and 15 weeks. As for the relation sFlt-1/PIGF, five studies have considered it even better for PE diagnosis when compared to sFlt-1 isolated.

CONCLUSION

The dosage of sFlt1 may be a relevant resource for the early diagnosis of preeclampsia before the installation of target organ damage, especially if measured in the period between 12 and 28 weeks of gestational age. Whereas sFlt-1 manifests itself before the 20th week, that may be interesting clinical point of view since it is this phase that settles the most severe cases, when the adoption of care could prevent further risks. The relationship sFlt1/PIGF, was more appropriate than the measurement of sFlt1 alone. Additional studies are needed to: amplification of the number of women evaluated, establishing gestational age appropriate for study, serum standard and need to consider the relationship between sFlt1 and other factors pro and/or anti-angiogenic.

Analysis of exosome release and its prognostic value in human colorectal cancer

A significant proportion of extracellular nucleic acids in plasma circulate highly protected in tumor-specific exosomes, but it is unclear how the release of exosomes is modulated in carcinogenesis. We quantified by cytometry exosomes in plasma of 91 colorectal cancer patients to evaluate their potential as a tumor indicator and their repercussions on diagnosis and prognosis. We examined the involvement of TSAP6, a TP53-regulated gene involved in the regulation of vesicular secretion, in levels of circulating exosomes in plasma of colorectal patients and in HCT116 TP53-(wild-type and null) human colorectal cancer cell lines. The fraction of exosomes in cancer patients was statistically higher than in healthy controls (mean rank ¼ 53.93 vs. 24.35). High levels of exosomes in plasma of patients correlated with high levels of carcino-embryonic antigen (P ¼ 0.029) and with poorly differentiated tumors (P ¼ 0.039) and tended to have shorter overall survival than patients with low levels (P ¼ 0.056). Release of exosomes did not correlate with TSAP6 expression; and regulation of TSAP6 by TP53 was not shown either in tumor samples or in HCT116 cell lines. Although it was not suggested that the TP53/TSAP6 pathway regulates the release of exosomes into the plasma of colorectal cancer patients, the level of circulating exosomes may be used as a tumor indicator, because it correlates with poor prognosis parameters and shorter survival.

Discovery and optimization of 2,4-diaminoquinazoline derivatives as a new class of potent dengue virus inhibitors

The results of a high-throughput screening assay using the DENV-2 replicon showed that the 2,4-diaminoquinazoline derivative 4a has a high dengue virus inhibitory activity (EC(50) = 0.15 μM). A series of 2,4-diaminoquinazoline derivatives based on 4a as a lead compound were synthesized and subjected to structure-antidengue activity relationship studies. Among the series of 2,4-diaminoquinazoline derivative probed, 4o was observed to display both the highest antiviral potency (EC(50) = 2.8 nM, SI > 1000) and an excellent pharmacokinetic profile.

Transmission of pandemic influenza H1N1 (2009) in Vietnamese swine in 2009-2010

BACKGROUND

The pandemic of 2009 was caused by an H1N1 (H1N1pdm) virus of swine origin. This pandemic virus has repeatedly infected swine through reverse zoonosis, although the extent of such infection in swine remains unclear.

OBJECTIVE

This study targets small and commercial pig producers in North Vietnam, in order to estimate the extent of H1N1pdm infection in swine and to identify the risk factors of infection.

METHODS

Virologic and serologic surveillance of swine was carried out in 2009-2010 in pig farms (38 swabs and 1732 sera) and at a pig slaughterhouse (710 swabs and 459 sera) in North Vietnam. The sera were screened using a influenza type A-reactive ELISA assay, and positive sera were tested using hemagglutination inhibition tests for antibody to a panel of H1-subtype viruses representing pandemic (H1N1) 2009 (H1N1pdm), triple reassortant (TRIG), classical swine (CS), and Eurasian avian-like (EA) swine lineages. Farm-level risk factors were identified using a zero-inflated negative binomial model.

RESULTS

We found a maximal seroprevalence of H1N1pdm of 55·6% [95% CI: 38·1-72·1] in the slaughterhouse at the end of December 2009, 2 weeks after the peak of reported human fatalities with H1N1pdm. Farm-level seroprevalence was 29% [95% CI: 23·2-35·7]. In seropositive farms, within-herd seroprevalence ranged from 10 to 100%. We identified an increased risk of infection for farms that specialized in fattening and a decreased risk of infection in farms hiring external swine workers.

CONCLUSIONS

Our findings suggest extensive reverse-zoonotic transmission from humans to pigs with subsequent onward transmission within pig herds.

Looking for avian influenza in remote areas. A case study in Northern Vietnam

Epidemiological surveys of avian influenza infections rarely focus on backyard poultry systems in remote locations because areas with low levels of poultry production are considered to have little influence on the emergence, re-emergence, persistence or spread of avian influenza viruses. In addition, routine disease investigations in remote areas often are neglected due to the lower availability and relatively high cost of veterinary services there. A bank of avian sera collected in 2005 from ethnic minority households in Ha Giang province (Northern Vietnam), located on the Chinese border, was analysed to estimate the seroprevalence of avian influenza virus (AIV) during a H5N1 epidemic and to identify potential risk factors for infection. The results suggest that the chicken population had been exposed to AIV with a seroprevalence rate of 7.2% [1.45; 10.5]. The H5 and H9 subtypes were identified with a seroprevalence of 3.25% [2.39; 4.11] and 1.12% [0.61; 1.63], respectively. The number of inhabitants in a village and the distance to the main national road were the most influential risk factors of AIV infection, and high-risk clusters were located along the road leading to China. These two results suggest a virus spread through commercial poultry exchanges and a possible introduction of AIV from southern China. Remote areas and small-scale farms may play an under-estimated role in the spread and persistence of AIV.

In vitro culture of bovine embryos in murine ES cell conditioned media negatively affects expression of pluripotency-related markers OCT4, SOX2 and SSEA1

Despite extensive efforts, establishment of bovine embryonic stem (ES) cell lines has not been successful. We hypothesized that culture conditions for in vitro-produced (IVP) embryos, the most used source of inner cell mass (ICM) to obtain ES cells, might affect their undifferentiated state. Therefore, the aim of this work was to improve pluripotency of IVP blastocysts to produce suitable ICM for further culturing. We tested KSR and foetal calf serum (FCS) supplements in SOF medium and ES cell conditioned medium (CM) on IVC (groups: KSR, KSR CM, FCS and FCS CM). Cleavage and blastocyst rates were similar between all groups. Also, embryonic quality, assessed by apoptosis rates (TUNEL assay), total cell number and ICM percentage did not differ between experimental groups. However, expression of pluripotency-related markers was affected. We detected down-regulation of OCT3/4, SOX2 and SSEA1 in ICM of FCS CM blastocysts (p < 0.05). SOX2 gene expression revealed lower levels (p < 0.05) on KSR CM blastocysts and a remarkable variation in SOX2 mRNA levels on FCS-supplemented blastocysts. In conclusion, pluripotency-related markers tend to decrease after supplementation with ES cell CM, suggesting different mechanisms regulating mouse and bovine pluripotency. KSR supplementation did not differ from FCS, but FCS replacement by KSR may produce blastocysts with stable SOX2 gene expression levels.

Early development and putative primordial germ cells characterization in dogs

Previously, three distinct populations of putative primordial germ cells (PGCs), namely gonocytes, intermediate cells and pre-spermatogonia, have been described in the human foetal testis. According to our knowledge, these PGCs have not been studied in any other species. The aim of our study was to identify similar PGC populations in canine embryos. First, we develop a protocol for canine embryo isolation. Following our protocol, 15 canine embryos at 21-25 days of pregnancy were isolated by ovaryhysterectomy surgery. Our data indicate that dramatic changes occur in canine embryo development and PGCs specification between 21 to 25 days of gestation. At that moment, only two PGC populations with distinct morphology can be identified by histological analyses. Cell population 1 presented round nuclei with prominent nucleolus and a high nuclear to cytoplasm ratio, showing gonocyte morphology. Cell population 2 was often localized at the periphery of the testicular cords and presented typical features of PGC. Both germ cell populations were positively immunostained with anti-human OCT-4 antibody. However, at day 25, all cells of population 1 reacted positively with OCT-4, whereas in population 2, fewer cells were positive for this marker. These two PGCs populations present morphological features similar to gonocytes and intermediate cells from human foetal testis. It is expected that a population of pre-spermatogonia would be observed at later stages of canine foetus development. We also showed that anti-human OCT-4 antibody can be useful to identify canine PGC in vivo.

EPAS1 mRNA in plasma from colorectal cancer patients is associated with poor outcome in advanced stages

The presence of free nucleic acids in plasma has been detected in cancer patients and is associated with poor prognosis. In the present study, the mRNA levels of three genes (EPAS1, KIAA0101 and UBE2D3) in plasma from colorectal cancer patients were analyzed. These genes were selected from a previous study of genomic profiles, discriminating between healthy controls and colorectal cancer patients. mRNA levels were analyzed by real-time PCR in the plasma of 154 patients with colorectal cancer. The association of plasma mRNA levels with clinicopathological parameters and patient survival were analyzed. High levels of EPAS1 in the plasma were associated with patients aged over 50 years, relapse of disease and patient mortality. When patients were divided into two groups, early (I and II) and advanced (III and IV) stages, an association was observed between high levels of EPAS1 mRNA and worse disease-free and overall survival in advanced stages. The expression of KIAA0101 and UBE2D3 was not associated with poor prognosis. Thus, our results suggest that EPAS1 mRNA levels may be an indicator of poor prognosis in colorectal cancer patients at advanced stages, obtained by a non-invasive method.

Production of influenza pseudotyped lentiviral particles and their use in influenza research and diagnosis: an update

Pseudotyped viral particles are being used as safe surrogates to mimic the structure and surface of many viruses, including highly pathogenic viruses such as avian influenza H5N1, to investigate biological functions mediated by the envelope proteins derived from these viruses. The first part of this article evaluates and discusses the differences in the production and characterization of influenza pseudoparticles. The second part focuses on the applications that such a flexible tool can provide in modern influenza research, in particular in the fields of drug discovery, molecular biology and diagnosis.

Kinetics of neutralizing antibodies in patients naturally infected by H5N1 virus

BACKGROUND

Little is known about the kinetics of anti-H5 neutralizing antibodies in naturally H5N1-infected patients with severe clinical illness or asymptomatic infection.

METHODS

Using H5N1 microneutralisation (MN) and H5-pseudotype particle-based microneutralisation assays (H5pp) we analyzed sera sequentially obtained from 11 severely ill patients diagnosed by RT-PCR (follow-up range 1-139 weeks of disease onset) and 31 asymptomatically infected individuals detected in a sero-epidemiological study after exposure to H5N1 virus (follow-up range: 1-2 month-11 months after exposure).

RESULTS

Of 44 sera from 11 patients with H5N1 disease, 70% tested positive by MN (antibody titre > or = 80) after 2 weeks and 100% were positive by 3 weeks after disease onset. The geometric mean MN titers in severely ill patients were 540 at 1-2 months and 173 at 10-12 months and thus were higher than the titers from asymptomatic individuals (149 at 1-2 months, 62.2 at 10-12 months). Fractional polynomial regression analysis demonstrated that in all severely ill patients, positive titers persisted beyond 2 years of disease onset, while 10 of 23 sera collected 10-11 months after exposure in asymptomatically infected individuals tested negative.

CONCLUSIONS

Our results indicate that people with asymptomatic H5N1 infection have lower H5N1 antibody titres compared to those with severe illness and that in many asymptomatically infected patients the antibody titer decreased to levels below the threshold of positivity within one year. These data are essential for the design and interpretation of sero-epidemiological studies.

Formation of virus-like particles from human cell lines exclusively expressing influenza neuraminidase

The minimal virus requirements for the generation of influenza virus-like particle (VLP) assembly and budding were reassessed. Using neuraminidase (NA) from the H5N1 and H1N1 subtypes, it was found that the expression of NA alone was sufficient to generate and release VLPs. Biochemical and functional characterization of the NA-containing VLPs demonstrated that they were morphologically similar to influenza virions. The NA oligomerization was comparable to that of the live virus, and the enzymic activity, whilst not required for the release of NA-VLPs, was preserved. Together, these findings indicate that NA plays a key role in virus budding and morphogenesis, and demonstrate that NA-VLPs represent a useful tool in influenza research.

Prevalence of antibodies against avian influenza A (H5N1) virus among Cullers and poultry workers in Ho Chi Minh City, 2005

BACKGROUND

Between 2003 and 2005, highly pathogenic avian influenza A (H5N1) viruses caused large scale outbreaks in poultry in the Ho Chi Minh City area in Vietnam. We studied the prevalence of antibodies against H5N1 in poultry workers and cullers who were active in the program in Ho Chi Minh City in 2004 and 2005.

METHODOLOGY/PRINCIPAL FINDINGS

Single sera from 500 poultry workers and poultry cullers exposed to infected birds were tested for antibodies to avian influenza H5N1, using microneutralization assays and hemagglutination inhibition assay with horse blood. All sera tested negative using microneutralization tests. Three samples showed a 1ratio80 titer in the hemagglutination inhibition assay.

CONCLUSIONS/SIGNIFICANCE

This study provides additional support for the low transmissibility of clade 1 H5N1 to humans, but limited transmission to highly exposed persons cannot be excluded given the presence of low antibody titers in some individuals.

Heterosubtype neutralizing responses to influenza A (H5N1) viruses are mediated by antibodies to virus haemagglutinin

Background

It is increasingly clear that influenza A infection induces cross-subtype neutralizing antibodies that may potentially confer protection against zoonotic infections. It is unclear whether this is mediated by antibodies to the neuraminidase (NA) or haemagglutinin (HA). We use pseudoviral particles (H5pp) coated with H5 haemagglutinin but not N1 neuraminidase to address this question. In this study, we investigate whether cross-neutralizing antibodies in persons unexposed to H5N1 is reactive to the H5 haemagglutinin.

Methodology/Principal Findings

We measured H5-neutralization antibody titers pre- and post-vaccination using the H5N1 micro-neutralization test (MN) and H5pp tests in subjects given seasonal vaccines and in selected sera from European elderly volunteers in a H5N1 vaccine trial who had detectable pre-vaccination H5N1 MN antibody titers. We found detectable (titer ≥20) H5N1 neutralizing antibodies in a minority of pre-seasonal vaccine sera and evidence of a serological response to H5N1 in others after seasonal influenza vaccination. There was excellent correlation in the antibody titers between the H5N1 MN and H5pp tests. Similar correlations were found between MN and H5pp in the pre-vaccine sera from the cohort of H5N1 vaccine trial recipients.

Conclusions/Significance

Heterosubtype neutralizing antibody to H5N1 in healthy volunteers unexposed to H5N1 is mediated by cross-reaction to the H5 haemagglutinin.

Imprinted gene expression in in vivo- and in vitro-produced bovine embryos and chorio-allantoic membranes

Cloning by nuclear transfer is often associated with poor results due to abnormal nuclear reprogramming of somatic donor cells and altered gene expression patterns. We investigated the expression patterns of imprinted genes IGF2 and IGF2R in 33- to 36-day bovine embryos and chorio-allantoic membranes derived from in vivo- and in vitro-produced embryos by somatic cell nuclear transfer (SCNT), parthenogenetic activation, and in vitro fertilization (IVF). There was a lower IGF2 expression rate in the SCNT (0.19) and parthenogenetic (0.02) groups when compared to in vivo and IVF embryos (2.01; P < 0.05). In the chorio-allantoic membranes, IGF2 showed a baseline expression pattern (P < 0.05) in parthenotes (0.001) when compared to in vivo, IVF (3.13), and SCNT (0.98) groups. IGF2R was less expressed (P < 0.05) in SCNT chorio-allantoic membranes (0.25) when compared to the in vivo group. The low expression of IGF2 in parthenogenetic embryos and chorio-allantoic membranes confirms its imprinted status in cattle. Alterations in the relative frequency of IGF2 and IGF2R transcripts were observed in SCNT-derived bovine embryos and chorio-allantoic membranes, respectively, supporting the hypothesis that abnormalities in the expression of imprinted genes are causes of the low efficiency of SCNT procedures in this species.

High-throughput screening using pseudotyped lentiviral particles: a strategy for the identification of HIV-1 inhibitors in a cell-based assay

Two decades after its discovery the human immunodeficiency virus (HIV) is still spreading worldwide and killing millions. There are 25 drugs formally approved for HIV currently on the market, but side effects as well as the emergence of HIV strains showing single or multiple resistances to current drug-therapy are causes for concern. Furthermore, these drugs target only 4 steps of the viral cycle, hence the urgent need for new drugs and also new targets. In order to tackle this problem, we have devised a cell-based assay using lentiviral particles to look for post-entry inhibitors of HIV-1. We report here the assay development, validation as well as confirmation of the hits using both wild-type and drug-resistant HIV-1 viruses. The screening was performed on an original library, rich in natural compounds and pure molecules from Traditional Chinese Medicine pharmacopoeia, which had never been screened for anti-HIV activity. The identified hits belong to four chemical sub-families that appear to be all non-nucleoside reverse transcriptase inhibitors (NNRTIs). Secondary tests with live viruses showed that there was good agreement with pseudotyped particles, confirming the validity of this approach for high-throughput drug screens. This assay will be a useful tool that can be easily adapted to screen for inhibitors of viral entry.

Effect of recombinant bovine somatotropin (bST) on follicular population and on in vitro buffalo embryo production

The objective of this study was to evaluate the effect of bovine somatotropin (bST) on ovarian follicular population in buffalo heifers and its influence on oocyte quality, recovery rates and in vitro embryo production. We tested the hypothesis that bST treatment in buffalo females submitted to an ovum pick-up (OPU) program would improve the number of follicles recruited, oocyte quality and in vitro embryo production. A total of 10 heifers were assigned into two treatment groups: group bST (n=5; receiving 500 mg of bST in regular intervals) and control group (n=5; without additional treatment). Both groups were subjected to OPU sessions twice a week (every 3 or 4 days), for a total of 10 sessions per female, although due to procedural problems, only the first five OPU sessions produced embryos. The number of follicles and the diameters were recorded at all OPU sessions. The harvested oocytes were counted and classified according to their quality as either A, B, C, D or E, with A and B considered good quality. Cleavage and blastocyst production rates were evaluated 2 and 7 days after in vitro fertilization, respectively. The bST treatment increased the total number of antral follicles (>3mm in diameter; 12.2 compared with 8.7; p<0.05) and of small antral follicles (<5mm; 9.1 compared with 6.5; p<0.05) per OPU session. The bST also tended to increase the number of oocytes recovered per session (5.2 compared with 4.1; p=0.07), and enhanced the percentage of good quality oocytes (48.8% compared with 40.6%; p=0.07). bST showed no effect on cleavage and blastocyst production rates (p>0.05). The significant effects of performing repeated OPU sessions were decreasing the follicular population (p<0.001) as well as the number of follicles aspirated (p<0.001), and oocytes recovered (p<0.02). In conclusion, bST treatment improves the follicular population, demonstrating its possible application in buffalo donors submitted to OPU programs.

Placentation in cloned cattle: Structure and microvascular architecture

To elucidate the morphological differences between placentas from normal and cloned cattle pregnancies reaching term, the umbilical cord, placentomes and interplacentomal region of the fetal membranes were examined macroscopically as well as by light and scanning electron microscopy. In pregnancies established by somatic nucleus transfer (NT), the umbilical cord and fetal membranes were edematous. Placentomal fusion was common, resulting in increased size and a decreased number of placentomes. Extensive areas of the chorioallantoic membrane were devoid of placentomes. An increased number of functional or accessory microcotyledons (<1 cm) were present at the maternally oriented surface of fetal membranes. Extensive areas of extravasated maternal blood were present within the placentomes and in the interplacentomal region. The crypts on the caruncular surface were dilated and accommodated complexes of more than one primary villus, as opposed to a single villus in non-cloned placentae. Scanning electron microscopy of blood vessel casts revealed that there was also more than one stem artery per villous tree and that the ramification of the vessels failed to form dense complexes of capillary loops and sinusoidal dilations as in normal pregnancies. At the materno-fetal interface, however, the trophoblast and uterine epithelium had normal histology. In conclusion, the NT placentas had a range of pathomorphological changes; this was likely associated with the poor clinical outcome of NT pregnancies.

Role of roscovitine and IBMX on kinetics of nuclear and cytoplasmic maturation of bovine oocytes in vitro

The 3-isobutyl-1-methylxanthine (IBMX) is able to prevent resumption of meiosis by maintaining elevated cyclic AMP (cAMP) concentrations in the oocyte, and roscovitine, a purine known to specifically inhibit MPF kinase activity, maintains bovine oocytes at the germinal vesicle (GV) stage. The present study was conducted to analyze whether cytoplasmic maturation (examined by the pattern of cortical granule (CG) distribution) of bovine oocytes is improved during meiotic arrest with IBMX and roscovitine. Oocytes were matured in vitro in a 10% Knockout(SR) supplemented TCM-199 medium (Control) with either 0.5 mM IBMX or 25 microM roscovitine (ROSC). Oocytes were stained with fluorescein isothiocyanate conjugated Lens culinaris agglutinin (FITC-LCA) for CG evaluation and with Hoechst 33342 for nuclear stage assessment. At 16 h of culture, the percentage of oocytes remaining in the GV stage was higher (P < 0.05) in the ROSC group (32.41%) compared with the Control and IBMX groups (8.61% and 9.73%, respectively). At 24 h of culture, progression of meiosis to M II stage was retarded (P < 0.05) in the ROSC group (24.05%) compared to the Control (60.20%), whereas the IBMX group (33.88%) showed no significant difference to the other two groups. At 16 h of maturation, the proportion of oocytes with CG in clusters (immature cytoplasm) was similar between the groups, as was the percentage of peripheral CG (mature) at 24 h of maturation. The results of the present study demonstrated that the meiotic inhibitors IBMX and roscovitine delay the progression of nuclear maturation without affecting cytoplasmic maturation, assessed by the analysis of CG repositioning.

Hemagglutinin pseudotyped lentiviral particles: characterization of a new method for avian H5N1 influenza sero-diagnosis

BACKGROUND

Highly pathogenic avian influenza (HPAI) H5N1 has spread globally in birds and infected over 270 humans with an apparently high mortality rate. Serologic studies to determine the extent of asymptomatic H5N1 infection in humans and other mammals and to investigate the immunogenicity of current H5N1 vaccine candidates have been hampered by the biosafety requirements needed for H5N1 micro-neutralization tests.

OBJECTIVE

Development of a serodiagnostic tool for highly pathogenic influenza that reproduces H5N1 biology but can be used with less biohazard.

STUDY DESIGN

We have generated and evaluated H5 hemagglutinin pseudotyped lentiviral particles encoding the luciferase reporter (H5pp).

RESULTS

H5pp entry into target cells depends on alpha2-3 cell surface sialic acids and requires low pH for membrane fusion. H5pp infectivity is specifically neutralized by sera from patients and animals infected with H5N1 and correlates well with conventional microneutralization test.

CONCLUSIONS

H5pp reproduce H5N1 influenza virus entry into target cells and potentially provides a high-throughput and safe method for sero-epidemiology.

Culture of mature trophoblastic giant cells from bovine placentomes

The mostly binucleate trophoblast giant cells (TGC) found in bovine placentomes, in addition to synthesizing and releasing hormones play an important role in fetal development and maternal adaptation to pregnancy. Placentomes from early gestation were collected, and for isolation of mature TGC, three cellular disaggregation methods, mechanical (MECH), enzymatic by trypsin (TRYP) or collagenase (COLL) were compared to each other. Further on, the cell survival in culture medium (DMEM) supplemented with either 10% fetal calf serum (FCS) or 10% serum replacement (SR) on culture plates free of any substrate was evaluated over a period of 90 days by trypan blue exclusion. The cells were further characterized by HOECHST 33342 nuclear staining, and immunocytochemical staining with monoclonal antibodies against vimentin and cytokeratin. A mean total rate of TGC survival of 82.56% was recorded. Statistical analysis showed significantly higher survival rates after enzymatic disaggregation with COLL (86.23%) than following MECH (80.38%) or TRYP (80.91%) treatment. Supplementation of DMEM with FCS resulted in significantly higher cellular survival rates (87.13%) when compared to the addition of SR (77.73%). Analysis of the influence of both, disaggregation method and medium supplementation on TGC survival revealed statistically significant differences between the following groups: MECH-SR (71.09%) was significantly lower than all other groups; TRYP-SR (78.03%) was significantly different from all other groups; TRYP-FCS (83.43%) and COLL-SR (84.08%) were significantly lower than MECH-FCS (89.98%) which together with COLL-FCS (88.25%) showed the highest cellular survival rate. In summary, our results show that TGC isolated from early gestation placentomes may be viable for more than 90 days of culture. However, whether these TGC produce placental lactogen throughout this period has yet to be determined.

Determination of glyoxylyl-peptide concentration using oxime chemistry and RP-HPLC analysis

Glyoxylyl-peptides are useful peptide derivatives in the context of hydrazone, oxime or thiazolidine ligations. We describe a method for the determination of glyoxylyl-peptide concentration based on the reaction of the alpha-oxo aldehyde group with an excess of O-benzylhydroxylamine. The amount of O-benzylhydroxylamine necessary to convert the alpha-oxo aldehyde group into the corresponding O-benzyloxime was determined by RP-HPLC analysis and corresponded to the quantity of glyoxylyl-peptide used in the experiment. The method is rapid, sensitive, accurate and allows the automated analysis of several samples.

Analysis of long-term gene expression in neurons of the hippocampal subfields following traumatic brain injury in rats

After experimental traumatic brain injury (TBI), widespread neuronal loss is progressive and continues in selectively vulnerable brain regions, such as the hippocampus, for months to years after the initial insult. To clarify the molecular mechanisms underlying secondary or delayed cell death in hippocampal neurons after TBI, we compared long-term changes in gene expression in the CA1, CA3 and dentate gyrus (DG) subfields of the rat hippocampus at 24 h and 3, 6, and 12 months after TBI with changes in gene expression in sham-operated rats. We used laser capture microdissection to collect several hundred hippocampal neurons from the CA1, CA3, and DG subfields and linearly amplified the nanogram samples of neuronal RNA with T7 RNA polymerase. Subsequent quantitative analysis of gene expression using ribonuclease protection assay revealed that mRNA expression of the anti-apoptotic gene, Bcl-2, and the chaperone heat shock protein 70 was significantly downregulated at 3, 6 (Bcl-2 only), and 12 months after TBI. Interestingly, the expression of the pro-apoptotic genes caspase-3 and caspase-9 was also significantly decreased at 3, 6 (caspase-9 only), and 12 months after TBI, suggesting that long-term neuronal loss after TBI is not mediated by increased expression of pro-apoptotic genes. The expression of two aging-related genes, p21 and integrin beta3 (ITbeta3), transiently increased 24 h after TBI, returned to baseline levels at 3 months and significantly decreased below sham levels at 12 months (ITbeta3 only). Expression of the gene for the antioxidant glutathione peroxidase-1 also significantly increased 6 months after TBI. These results suggest that decreased levels of neuroprotective genes may contribute to long-term neurodegeneration in animals and human patients after TBI. Conversely, long-term increases in antioxidant gene expression after TBI may be an endogenous neuroprotective response that compensates for the decrease in expression of other neuroprotective genes.

Sexing of murine and bovine embryos by developmental arrest induced by high-titer H-Y antisera

Murine and bovine embryos at the late morula stage were cultured in medium containing high-titer rat H-Y antisera. After 12h of incubation, embryos blocked at the late morulae stage were classified as males and those at the blastocyst stage were classified as females. Sexing of murine embryos by PCR and cytogenetics revealed that 83% of the embryos classified as males and 82% of those classified as females had their sex correctly predicted (P < 0.05). Bovine embryos were transferred to recipient females. Pregnancy rates were 71.4% (10/14) for embryos classified as males and 68.8% (11/16) for embryos classified as females. The sex was correctly predicted for 80% (8/10) of the embryos classified as males and for 81.8% (9/11) of those classified as females (overall accuracy, 80.9%, P < 0.05). Therefore, the induction of developmental arrest by high-titer male-specific antisera was an efficient strategy for non-invasive embryo sexing. The procedure was straightforward and has considerable commercial potential for sexing bovine embryos.

Computer simulation of an adaptive damage-bone remodeling law applied to three unit-bone bars structure

It is well admitted that the mechanical loading plays an important role in the growth and maintenance of our skeleton, and that microdamage (i.e.: microcracks) occurs naturally when the bone is overloaded during day-to-day activities. It is also argued, from experimental and theoretical viewpoint, that the cells which built and rebuilt the skeleton are sensitive for both strain and microdamage. The recent damage-bone remodeling theory is employed here to study the mechanical response of the three unit-bone bars that simulate bone trabeculae in the form of truss. It is shown that under constant load, such a structure exhibit inhomogeneous strain and it's response to external applied load depends strongly upon the manner in which the microdamage is distributed.