203 Genome Modifications by Sleeping Beauty Transposition and CRISPR/Cas9 to Improve Cow Milk Composition for Human Consumption

Genome manipulation of cattle represents a powerful tool to increase the nutritional value and reduce allergenicity of cow milk for human consumption. This could be accomplished by improving the amount of polyunsaturated fatty acids (ω-3 and ω-6) and simultaneously abolishing β-lactoglobulin (BLG), a potent allergen for predisposed humans. The aim of this study was to introduce the sequence for a desaturase construct (mFAT-2, from C. elegans), which is able to catalyse the synthesis of ω-3 and ω-6 fatty acids, into the bovine genome by Sleeping Beauty (SB) transposition, and simultaneously knocking out the bovine β-lactoglubulin gene using CRISPR/Cas9 system. The sgRNA (AAGTGCCTCCTGCTTGCCC) targeted to BLG exon 1 was synthesised as an oligo linker and cloned into the px459-Cas9. The mutation activity of the designed sgRNA at the target locus was determined by T7 endonuclease assay I (T7EI) mismatch detection assay. Briefly, bovine fetal fibroblasts (BFF) were seeded at 0.5 × 105 cells per well of a 24-well plate in triplicate, when the cells reached 80% confluence (12–24 h), cultures were transfected with 1 μg of px459-Cas9::BLG plasmid co-expressing Cas9 and sgRNA using polyethylenimine reagent (PEI; 3 ng μL−1). After 3 days of puromycin selection, genomic DNA from transfected cells were extracted and the sequence of interest was PCR-amplified and digested by T7EI restriction enzyme. Digestion products showed a mutation efficiency at the target locus of 29%. Subsequently, we chemically cotransfected 0.5 × 105 BFF with 0.5 μg of knockout vector (px459-Cas9::BLG) and 0.5 μg of SB plasmids (carrying mFAT-2 cDNA for mammary gland-specific expression) using 3 ng μL−1 PEI in triplicate. At 48 h post-transfection, cell cultures were subjected to 3 days of puromycin and 21 days of neomycin selection. PCR analysis of antibiotic resistant colonies revealed the presence of mFAT-2 transgene in almost 70% of the analysed cells lines. Genotyping of BLG exon 1 was performed by direct sequencing of PCR amplicons using primers flanking the target site. Despite the appreciable gene mutation activity of the sgRNA sequence previously determined by T7EI assay (29%), none of the cell lines analysed showed modification in the BLG target locus. We speculate that the SB vector might have disrupted the activity of targeting vector. We are currently performing additional experiments to accomplish gene addition (mFAT) and gene knockout (BGL) in one step using these highly efficient and precise transgenic tools. Genetically modified cells will be used as nuclear donor to produce transgenic cows by somatic cells nuclear transfer. The financial support of CONICET, UNRC and FONCYT is gratefully acknowledged.

356 SLEEPING BEAUTY TRANSGENESIS IN CATTLE

Transposon-mediated transgenesis is a well-established tool for genome modification in small animal models. However, translation of this active transgenic method to large animals warrants further investigations. Here, the Sleeping Beauty (SB) transposon system was assessed for stable gene transfer into the cattle genome. The transposon plasmids encoded a ubiquitously active CAGGS promoter-driven Venus reporter and a lens-specific α A-crystallin promoter driven tdTomato fluorophore, respectively. The helper plasmid carried the hyperactive SB100x transposase variant. In total, 50 in vitro-derived zygotes were co-injected (Garrels et al. 2011 PLoS ONE 6; Ivics et al. 2014 Nat. Protoc. 9) and cultured up to blastocyst stage (Day 8). Two blastocysts were Venus-positive and were transferred to synchronized heifers, resulting in one pregnancy. The resulting calf was normally developed and vital; however, it died shortly after cesarean section due to spontaneous bleeding from an undetected aneurism. Phenotypic analysis suggested that the calf was indeed double-transgenic, showing widespread expression of Venus and lens-specific expression of tdTomato. Genotyping and molecular analyses confirmed the integration of both reporter transposons and the faithful promoter-dependent expression patterns. Subdermal tissue of an ear biopsy was used to culture fibroblasts, which were employed in somatic cell nuclear transfer experiments. In total, 39 embryos were reconstructed, of which 34 underwent cleavage, and at the end of culture 12 morulas and 12 blastocysts were obtained. Ten of the blastocysts were Venus positive, and embryo transfer of Venus-positive blastocysts is planned. In summary, we showed that the cytoplasmic injection of SB components is a highly efficient method for transgenesis in cattle. Due to the modular composition of SB plasmids, even double transgenic cattle can be generated in a one-step procedure. Importantly, the SB-catalyzed integration seems to favour transcriptionally permissive loci in the genome, resulting in faithful and robust promoter-dependent expression of the transgenes. The transposon constructs carry heterospecific loxP sites, which will be instrumental for targeted insertion of functional transgenes by Cre recombinase-mediated cassette exchange.Financial support of DFG (Ku 1586/3-1), UNRC, CONICET and Agencia Nacional de Promoción Científica y Tecnológica de la Argentina (ANPCyT) is gratefully acknowledged.

357 EARLY FETAL DEVELOPMENT OF NUCLEAR TRANSFER BOVINE EMBRYOS GENERATED FROM FIBROBLASTS GENETICALLY MODIFIED BY piggyBac TRANSPOSITION

Transposon-mediated transgenesis is a well-established tool for genome manipulation in small animal models. However, translation of this active transgenesis method to the large animal setting requires further investigation. We have previously demonstrated that a helper-independent piggyBac (PB) transposon system can efficiently transpose transgenes into the bovine genome [Alessio et al. 2014 Reprod. Domest. Anim. 49 (Suppl. 1), 8]. The aims of the current study were a) to investigate the effectiveness of a hyperactive version of the PB transposase, and b) to determine the ability of the genetically modified cells to support early embryo and fetal development upon somatic cell nuclear transfer (SCNT). Bovine fetal fibroblasts (BFF) were chemically transfected with either pmGENIE-3 (a helper-independent PB transposon conferring genes for hygromycin resistance and enhanced green fluorescent protein (EGFP); Urschitz et al. 2010 PNAS USA 107, 8117–8122), pmhyGENIE-3 (carrying an hyperactive version of the PB transposase; Marh et al. 2012 PNAS USA 109, 19 184–19 189), or pmGENIE-3/Δ PB (a control plasmid lacking a functional PB transposase). Upon transfection, cell cultures were subjected to 14 days of hygromycin selection. Antibiotic-resistant and EGFP+ colonies were counted and data analysed by ANOVA and Tukey's test. For SCNT, pmhyGENIE-3 and pmGENIE-3 polyclonal cell lines were selected by FACS and individual cells used as nuclear donors. Day 7 blastocysts were nonsurgically transferred to synchronized recipients. Conceptuses were recovered by Day 35 of gestation, observed under fluorescence excitation, and genotyped. The mean number of colonies in pmhyGENIE-3 group was significantly higher than those in pmGENIE-3 and the control group (324.0 ± 17.8 v. 100.0 ± 16.1 and 2.8 ± 0.8 respectively, n = 4–7; P < 0.05). The hyperactive transposase increased transgene integration efficiency 3.24 times compared with the conventional PB transposase. The SCNT and early fetal development data are summarised in Table 1. Phenotypic analysis revealed that both transgenic fetuses and the extraembryonic membranes expressed EGFP with no macroscopic evidence of variegated transgene expression. Molecular analysis by PCR confirmed that both fetuses carried the transposon DNA. Here, we demonstrate that a hyperactive version of the PB transposase is more active in bovine cells than the conventional PB transposase. In addition, SCNT embryos generated from genetically modified cells by the pGENIE transposon system can progress to early stages of fetal development. Table 1.SCNT and early fetal development of bovine fibroblasts transposed with piggyBac1 The financial support of UNRC, CONICET and ANPCyT from Argentina is gratefully acknowledged.

[Ultrasonographic and clinical methods in the management of prolonged pregnancy]

AIM

The aim of this study was to evaluate the role of Bishop score, sonographic measurements of uterine cervical length and maternal characteristics, as predictors of spontaneous onset of labor within 24 hours, as well as response to induction in prolonged pregnancies.

METHODS

Pregnancies with gestational age over 280 days were followed as outpatient. Patients were included in the study if spontaneous delivery occurred between 286 and 295 days of gestation, or in pregnancies with gestational age of 291-293 days who required labor induction. Data about Bishop score, ultrasonographic cervical characteristics (length, funneling, volume) and maternal features (parity, body mass index and age) registered at the last control immediately before the delivery were retrieved from clinical charts.

RESULTS

Data from 195 patients were available. Bishop score and, in particular, ultrasonographic cervical length can predict the spontaneous onset of labor with a positive predictive value (PPV) of 22% and 44%, respectively in 24 hours. On the other hands, in patients requiring labor induction, parity and ultrasonographic cervical length remained the only predictive parameters with a PPV of 39% and 42%, respectively. In term of predictive performance, the value of 30 mm was identified as the best cut-off value for the ultrasonographic cervical length (specificity 59% and sensitivity 69%).

CONCLUSION

In prolonged pregnancies, Bishop score and ultrasonographic cervical length were shown to be relevant in the prediction of spontaneous onset of labor, while in patients who required labor induction, ultrasonographic cervical length represented the only clinic parameter predicting the onset of labor.

Genotypes B and C hepatocellular carcinoma-associated hepatitis B virus pre-S mutants: their detection among F1b and A2 - but not F4 - isolates from Argentina

Prevalence rates of hepatocellular carcinoma (HCC)-associated hepatitis B virus (HBV) pre-S mutants among most genotypes are still lacking. In this study, viral (sub)genotypes of 70 Argentine nucleotide sequences (33 newly obtained) were determined by phylogenetic analysis, and the presence of such mutants was assessed in the American continent for the first time. Nucleotide substitutions of the pre-S2 start codon were observed in 10% of the HBV/A2 sequences. Ten per cent of the HBV/A2 and 12.5% of the HBV/F1b - but none of HBV/F4 - exhibited a deletion in the pre-S1/pre-S2 region. The contribution of these variants to liver cirrhosis (LC) and/or HCC development among HBV/F and HBV/A isolates deserves further prospective clinical studies.

EEG spike source localization before and after surgery for temporal lobe epilepsy: a BOLD EEG-fMRI and independent component analysis study

Simultaneous measurements of EEG-functional magnetic resonance imaging (fMRI) combine the high temporal resolution of EEG with the distinctive spatial resolution of fMRI. The purpose of this EEG-fMRI study was to search for hemodynamic responses (blood oxygen level-dependent--BOLD responses) associated with interictal activity in a case of right mesial temporal lobe epilepsy before and after a successful selective amygdalohippocampectomy. Therefore, the study found the epileptogenic source by this noninvasive imaging technique and compared the results after removing the atrophied hippocampus. Additionally, the present study investigated the effectiveness of two different ways of localizing epileptiform spike sources, i.e., BOLD contrast and independent component analysis dipole model, by comparing their respective outcomes to the resected epileptogenic region. Our findings suggested a right hippocampus induction of the large interictal activity in the left hemisphere. Although almost a quarter of the dipoles were found near the right hippocampus region, dipole modeling resulted in a widespread distribution, making EEG analysis too weak to precisely determine by itself the source localization even by a sophisticated method of analysis such as independent component analysis. On the other hand, the combined EEG-fMRI technique made it possible to highlight the epileptogenic foci quite efficiently.

Differences in memory performance and other clinical characteristics in patients with mesial temporal lobe epilepsy with and without hippocampal atrophy

Mesial temporal lobe epilepsy (MTLE) is usually accompanied by memory deficits due to damage to the hippocampal system. In most studies, however, the influence of hippocampal atrophy (HA) is confounded with other variables, such as: type of initial precipitating injury and pathological substrate, effect of lesion (HA) lateralization, history of febrile seizures, status epilepticus, age of seizure onset, duration of epilepsy, seizure frequency, and antiepileptic drugs (AEDs). To investigate the relationship between memory deficits and these variables, we studied 20 patients with MTLE and signs of HA on MRI and 15 MTLE patients with normal high-resolution MRI. The findings indicated that (1) HA, earlier onset of seizures, longer duration of epilepsy, higher seizure frequency, and AEDs (polytherapy) are associated with memory deficits; and (2) there is a close relationship between deficits of verbal memory and left HA, but not between visual memory and right HA.

[Biological monitoring of occupational exposure to desflurane]

In these last years Desflurane (D) has become used, alone or in combination with nitrous oxide, in surgical procedures. Occupational exposed groups include anesthesiologists, other physicians, (e.g. surgeons) and operating room nurses. Desflurane is a halogenated methylethylether which is administered by inhalation. Desflurane is halogenated exclusively with fluorine. The blood/gas partition coefficient of Desflurane is 0.42. Changes in the clinical effects of Desflurane rapidly follow changes in the inspired concentration. Studies in man indicate that Desflurane washes into the body rapidly. It also washes out of the body rapidly, allowing flexibility in adjustment of the depth of anaesthesia. Desflurane is eliminated via the lungs, undergoing only minimal metabolism (0.02%). In order to investigate the role of urinary D as an indicator of occupational exposure to Desflurane (CI, ppm), CI was measured in 21 members of operating room staffs. For the measurement of environmental concentration of Desflurane (CI), the ambient air was sampled using personal passive dosimeters. The analyte was desorbed by a water-methanol mixture and was analysed by means a gas chromatograph--mass spectrometer (GC-MSD) and headspace technique. The biological monitoring of exposed workers was conducted by determining the concentration of Desflurane in urine (Cu, microgram/L). Urine concentrations of Desflurane were determined by headspace analysis using GC-MSD. Significant correlations were found between the environmental Desflurane concentration and the urinary concentrations. The correlation between CI (ppm) and Cu (microgram/L) was: Log D (Cu, microgram/L) = .191 + .922 * LogCI; r = .916 On the basis of the equation it was possible to establish tentatively the biological limit values corresponding to the respective occupational exposure limit values proposed for Desflurane.

[Monitoring air dispersed concentrations of aldehydes during the use of ortho-phthalaldehyde and glutaraldehyde for high disinfection of endoscopes]

Solutions of glutaraldehyde (GTA) and ortho-phthalaldehyde (OPA) can both be used for low-temperature disinfection of endoscopes. Currently, GTA is being replaced by OPA (an aromatic dialdehyde) at the San Matteo Hospital, as OPA is less dangerous for health care workers than GTA, but has a similar capacity to kill viruses, bacteria and spores. The aim of the study was to compare air levels of GTA and OPA in several endoscopy units at our hospital. The air samples were analysed by means of both Infrared Spectroscopy (IR) and HPLC-UV (High Performance Liquid Chromatography with UV detection). The HPLC method gave a much lower aldehyde value when using OPA (8.4 micrograms/m3) compared to that obtained when GTA was used to disinfect endoscopes (21.279.3 micrograms/m3). Both HPLC and IR methods detected low levels of OPA in air, the mean values being below 10 micrograms/m3. In addition, we studied the resistance of various types of gloves to OPA. Tests showed that OPA permeated vinyl gloves more rapidly (26,628 ng/cm2 per hour) than nitrile gloves (13.9 ng/cm2 per hour).

Urinary determination of N-acetyl- S-( N-methylcarbamoyl)cysteine and N-methylformamide in workers exposed to N, N-dimethylformamide

OBJECTIVES

We conducted this biomonitoring study with the aim of evaluating the correlation between the excretion of N-methylformamide (NMF) (mainly from N-hydroxy- N-methylformamide) and N-acetyl- S-( N-methylcarbamoyl)cysteine (AMCC), and levels of exposure to N, N-dimethylformamide (DMF) among occupationally exposed subjects.

METHODS

Exposure levels were determined by personal sampling: breathing zone air samples were collected by means of passive samplers. DMF collected by the charcoal in personal samplers was analysed after extraction with methanol by a gas chromatograph. For the purpose of biological monitoring the levels of NMF and AMCC were measured in pre-shift and post-shift samples. Determinations were carried out by, respectively, gas chromatography and high performance liquid chromatography (HPLC).

RESULTS AND CONCLUSIONS

The mean time-weighted average (TWA) exposure was approximately half (13.5 mg/m(3)) of the current threshold limit value, the range of the values was from 0.4 to 75.2 mg/m(3). Environmental DMF concentrations exhibited a significant correlation with the specific mercapturic acid (AMCC) collected at the end of the working week (AMCC Friday morning mg/l=1.384xDMF (mg/m(3))+8.708; r(2)=0.47; P<0.008]; hence urinary AMCC represents an index of the average exposure during several preceding working days, making it possible to calculate the approximate relationship between DMF uptake and excretion of this metabolite. A significant correlation was found also between the daily excretion of NMF and the corresponding levels of DMF in air. The equation of the regression line was: NMF (mg/g creatinine)=0.936xDMF (mg/m(3))+7.306; r(2)=0.522 ( P<0.0001).

[High-pressure liquid chromatography (HPLC) with UV developer for the analysis of N-acetyl-S-(N-methylcarbomoyl)cysteine (AMCC)]

N,N-dimethylformamide (DMF) is a solvent widely used to prepare synthetic fibers. Biomonitoring of DMF is usually performed by measuring urinary N-methylformamide, which allows us to estimate exposure during the working day. An alternative biomarker is the mercapturic acid N-acetyl-S-(N-methylcarbamoyl)cysteine (AMCC) whose excretion accounts for about 13% of the absorbed DMF dose. Owing to its slow excretion (mean half-life = 23 hours) the urinary levels of AMCC at the end of a workweek reflect the cumulative dose of DMF during the whole week. Methods given in literature for measuring AMCC need the derivatization of the molecule before analysis. The paper describes a method for the determination of urinary AMCC by high-performance liquid chromatography (HPLC) with direct UV detection. Samples were purified by solid phase extraction with C18 and ENV+ cartridges, then 10 microliters were directly injected onto an Aminex HPX-87H Ion Exclusion column maintained at a temperature of 37 degrees C. Analyses were performed by isocratic run with 1 mM sulphuric acid delivered at 0.85 mL/min. The detector was set at 196 nm. Under these conditions, AMCC eluted at 11.1 min., and the detection and quantification limits were 1.32 mg/L and 3.96 mg/L, respectively. The performance of the method was evaluated on samples containing 25 mg/L and 400 mg/L of AMCC: each sample was analysed three times. The mean recovery of the extraction procedure was 88.3%. The precision (CV%) and the accuracy (Error%) ranged from 0.8% to 2.9%, and from -1.2% to +3.2%. The calibration curve was linear up to a concentration of 1000 mg/L, the coefficient of correlation was r = 0.9997. AMCC was measured in urine samples from 30 exposed and 20 unexposed (smokers and nonsmokers) subjects. Measurable amounts of AMCC were found in all of the samples from workers exposed to DMF; on the contrary, none of the samples from unexposed subjects contained this metabolite. The proposed method is sufficiently sensitive and specific for the evaluation of occupational exposure to DMF, thus it could be useful for the biological monitoring of workers exposed to this solvent.

[Biological monitoring of occupational exposure to sevoflurane]

Sevoflurane has been used in the last few years in brief surgical operations, either alone or in combination with nitrous oxide. Occupationally exposed groups include anesthesiologists, surgeons and operating room nurses. In 1977 the National Institute for Occupational Safety and Health (NIOSH) recommended that occupational exposure to halogenated anesthetic agents (halothane, enflurane, and isoflurane), when used as the sole anesthetic, should be controlled so that no worker would be exposed to time-weighted average concentrations greater than 2 ppm during anesthetic administration. When halogenated anesthetics are associated with nitrous oxide, NIOSH recommends that the limit value should not exceed 0.5 ppm. We think these recommendations can be extended to sevoflurane. Metabolism of sevoflurane is catalyzed by cytochrome P-450; this involves oxidation of the fluoromethyl side chain of the molecule, followed by glucuronidation. Two urinary metabolites of sevoflurane have been identified: inorganic fluoride (which, however, is not specific) and a non-volatile compound that yields hexafluoroisopropanol (HFIP) when digested with the enzyme beta-glucuronidase. In order to investigate the role of urinary HFIP as an indicator of occupational exposure to sevoflurane (CI, ppm), CI was measured in 145 members of 18 operating room staffs. The measurements of the time-weighted average of CI in the breathing zone were made by means of diffusive personal samplers. Each sampler was exposed during the whole working period. Sevoflurane was desorbed with CS2 from charcoal and the concentrations were measured on a gas chromatograph (GC) equipped with a mass selective detector (MSD). The GC was equipped with a 25 meter cross-linked phenylmethylsilicon column (internal diameter 0.2 mm). GC conditions were as follows: injector column temperature = 200 degrees C; column temperature = 30 degrees C; carrier gas = helium; injection technique of samples = splitless. The analytical conditions for the MSD were the following: ion mass monitored = 131 m/e; dwell time = 50 msec; selected ion monitoring window time = 0.1 amu; electromultiplier = 400 V. Urine samples were collected near the end of the shift and were analyzed for HFIP by head-space gas chromatography after glucuronide hydrolysis. 0.5 ml of urine and 1.5 ml of 10 M sulfuric acid were added to 21.8 ml headspace vials. The vials were immediately capped, vortexed, and loaded into the headspace autosampler. Samples were maintained at 100 degrees C for 30 min, after which glucuronide hydrolysis was 99% complete. Analyses were performed on a GC equipped with a MSD. The analytical conditions for urine analysis were as follows: cross-linked 5% phenylmethylsilicon column (internal diameter 0.2 mm, length 25 m); column temperature = 35 degrees C; carrier gas = helium. The analytical conditions for the MSD were: monitored ions = 51.05 and 99; dwell time = 100 ms; selected ion monitoring window time = 0.1 amu; electromultiplier voltage = 2000 Volt. With our analytical procedure, the detection limit of HFIP in urine was 20 micrograms/L. The variation coefficient (CV) for HFIP measurement in urine was 8.7% (on 10 determinations; mean value = 1000 micrograms/L). The median value of CI was 0.77 ppm (Geometric Standard Deviation = 4.08; range = 0.05-27.9 ppm). The correlation between CI and HFIP (Cu, microgram/L) was: Log Cu (microgram/L) = 0.813 x Log CI (ppm) + 2.517 (r = 0.79, n = 145, p < 0.0001). On the basis of the equation it was possible to establish tentatively the biological limit values corresponding to the respective occupational exposure limit values proposed for sevoflurane. According to our experimental results, HFIP values of 488 micrograms/L and 160 micrograms/L correspond to airborne sevoflurane concentrations of 2 and 0.5 ppm respectively.

The distribution of D1S80 (pMCT118) alleles in a southern Italian population sample

A population study on the distribution of alleles for the D1S80 locus (pMCT118) was carried out on 141 unrelated and healthy blood donors from the province of Messina (Eastern Sicily). Forty-two different genotypes and 16 different alleles were observed and two of these were found to be relatively common in the sample. Hardy-Weinberg equilibrium was tested using a preliminary simple chi-square method by binning in five groups and an exact test. The results demonstrated that the population was in HWE for both tests. A comparison of our data with other population studies showed that the distributions of alleles were similar.

[Preliminary comparative results of the detection of hepatitis B antigen (HBAg) in the blood of mental patients, using several methods in common use]

Radioimmunoassay (RIA), immunoelectrophoresis (IEP) and latex agglutination (L-HHA) were compared in the detection of hepatitis B antigen in sera from 494 mental patients. Positivity was observed in 39 subjects (7.9%) with RIA, 14 (2.8%) with IEP, and 8 (1.6%) with L-HHA. The dilution titres noted with RIA were many times and significantly higher than those obtained with the other two methods. Antigen was again detected in over 50% of those subjects on whom it was possible to repeat the tests one year later. The advantages of RIA are stressed.