Efficacy of Retreatment After Failed Direct-acting Antiviral Therapy in Patients With HCV Genotype 1-3 Infections

Hepatitis C virus infection is causing chronic liver disease, cirrhosis, and hepatocellular carcinoma. By combining direct-acting antivirals (DAAs), high sustained virologic response rates (SVRs) can be achieved. Resistance-associated substitutions (RASs) are commonly observed after DAA failure, and especially nonstructural protein 5A (NS5A) RASs may impact retreatment options.^1-3 Data on retreatment of DAA failure patients using first-generation DAAs are limited.^4-7 Recently, a second-generation protease- and NS5A-inhibitor plus sofosbuvir (voxilaprevir/velpatasvir/sofosbuvir [VOX/VEL/SOF]) was approved for retreatment after DAA failure.⁸ However, this and other second-generation regimens are not available in many resource-limited countries or are not reimbursed by regular insurance, and recommendations regarding the selection of retreatment regimens using first-generation DAAs are very important. This study aimed to analyze patients who were re-treated with first-generation DAAs after failure of a DAA combination therapy.

Lack of awareness in both patients and physicians contributes to a high rate of late presentation in a South West German HIV patient cohort

PURPOSE

To assess rate of late presentation with HIV in Southwestern Germany and to identify patient characteristics correlated with CD4 nadir.

METHODS

Patients with primary diagnosis who presented to one of ten participating clinics rated on knowledge and behavior towards HIV testing on a self-developed questionnaire, whereas clinical data was assessed by the physician.

RESULTS

161 patients were included. Risk factors were homosexual (59.5 %) or heterosexual contacts (26.8 %), drug use (2.0 %), migration (3.9 %), or others (7.8 %). 63.5 % had a CD4 T cell count < 350/µl. 52.5, 17.4, and 31.1 % were diagnosed in CDC stadium A, B or C, respectively. 209 disease episodes were reported, from whom 83.7 % had led to the diagnosis of HIV. 75.2 and 68.3 % said to have been well-informed about ways of transmission and testing offerings, respectively, and 20.4 % admitted to have psychologically repressed the possibility of being infected. 48 patients rated their personal behavioral risk as "high" or "very high". Of these, however, only ten had performed at test in the precedent year. Performing a regression analysis, younger age and previous testing were correlated with a higher CD4 T cell nadir (p = 0.005, and 0.018, resp.).

CONCLUSION

The rate of late presentation in this region was even higher compared to national or European surveys. Most infected patients perceived to have had only a low risk. Several disease episodes did not lead to the initiation of HIV testing by the physician.

Computed tomography angiography (CTA) to prove circulatory arrest for the diagnosis of brain death in the context of organ transplantation

QUESTION UNDER STUDY

For the determination of brain death (BD) in potential organ donors, confirmatory tests that show cessation of cerebral circulation are used in many countries. Conventional angiography is considered the golden standard among these ancillary examinations. In recent years other angiographic techniques such as CT angiography (CTA) have been increasingly employed to establish the diagnosis of BD. We report our experience with CTA in this setting.

MATERIAL AND METHODS

From 2007 to 2010, 29 patients were examined in order to determine BD using CTA. The studies consisted of an unenhanced head scan, a CT angiogram of the brain supplying vessels in the head and neck and a second head scan 80 seconds after contrast injection (venous phase). The studies were retrospectively re-evaluated by two experienced neuroradiologists according to the criteria accepted by the Swiss Academy of Medical Sciences.

RESULTS

In 22 patients, cessation of cerebral circulation was confirmed in the venous phase CT. In seven patients, cessation of brain circulation was not confirmed due to residual contrast enhancement in the relevant cerebral vessels, i.e. the M4-segments of the middle cerebral artery and/or the internal cerebral veins. In these patients, clinical re-evaluation after a minimum of six hours confirmed the diagnosis of BD. Using the clinical examination as the "golden standard," CTA achieved a sensitivity of 75.9%.

CONCLUSION

CTA is a useful additional tool for the confirmation of the diagnosis of brain death. Pooling of contrast in the relevant cerebral vessels, however, can be detected in up to 25% of CTAs in clinically brain dead patients.

Low-dose temporal bone CT in infants and young children: effective dose and image quality

BACKGROUND AND PURPOSE

The temporal bone is ideal for low-dose CT because of its intrinsic high contrast. The aim of this study was to retrospectively evaluate image quality and radiation doses of a new low-dose versus a standard high-dose pediatric temporal bone CT protocol and to review dosimetric data from the literature.

MATERIALS AND METHODS

Image quality and radiation doses were compared for 38 low-dose (80 kV/90-110 mAs) and 16 high-dose (140 kV/170 mAs) temporal bone CT scans of infants to 5-year-old children. The CT visualization quality of 23 middle and inner ear structures was subjectively graded by 3 neuroradiologists and 3 otologists by using a 5-point scale with scores 1-2 indicating insufficient and scores 3-5 indicating sufficient image quality. Effective doses of local and literature-derived protocols were calculated from dosimetric data by using NRPB-SR250 software.

RESULTS

Insufficient image-quality scores were more frequent in low-dose scans versus high-dose scans, but the difference was only statistically significant for otologists (6.0% versus 3.4%, P = .004) and not for neuroradiologists (1.2% versus 0.7%, P = .84). Image quality was critical for small structures (such as the stapes or lamella at the internal auditory canal fundus). Effective doses were 0.25-0.3 mSv for low-dose scans, 1.4-1.8 mSv for high-dose scans, and 0.9-2.6 mSv for literature-derived protocols.

CONCLUSIONS

The image quality of the new low-dose protocol remains diagnostic for assessing middle and inner ear anatomy despite a 3- to 8-fold dose reduction over previous and literature-derived protocols. However, image quality of small structures is critical and may be perceived as insufficient.

339 BIOENGINEERING OF THE MAMMARY GLAND OF LIVESTOCK: INCREASED PROPEPTIDE PROCESSING OF FACTOR IX IN THE MILK OF TRANSGENIC PIGS BY CO-EXPRESSION OF FURIN

Coagulation Factor IX is a vital protein that plays an important role in the blood coagulation cascade. Hereditary deficiency in the Factor IX gene can result in hemophilia type B, the second most common hemophilia. The milk of transgenic livestock can be an efficient vehicle for producing complex, post-translationally modified blood proteins. The advantages include decreased pathogen risk as well as 100-fold or more production efficiency over blood fractionation and cell culture biotechnology. Although the mammary gland can make many of the complex post-translational modifications necessary for biological function of blood proteins, improvements in propeptide cleavage and decreased proteolytic degradation are desirable. To explore the possibility of producing bioactive human Factor IX protein in pig milk, male and female Landrace fetal fibroblast cells were co-transfected by electroporation with 3 different transgene constructs, Factor IX (FIX), Furin, and SERPINA1. The SERPINA1 construct (containing a Neo selectable marker) was delivered into fetal fibroblasts at a 10-fold-lower molar concentration than the other 2 constructs. Following selection in Geneticin, the presence of all 3 genes was verified by PCR and then cells were used as donors for somatic cell nuclear transfer. Thirteen F0 female piglets from 3 potential different integrations were delivered, and 6 piglets were validated by PCR to be positive for all 3 genes. Among the 6 transgenic pigs, 3 are healthy and able to reach puberty. Milk was collected by induced lactation from 2 gilts. A short murine whey acidic protein promoter-Furin gene was used to limit Furin to the lowest levels needed for pro-FIX processing. Furin was expressed to increase propeptide cleavage efficiency, with the result being complete processing of pro-FIX to FIX at ∼0.3 g L–1 pro-FIX. Total FIX levels were ∼1 g L–1. SERPINA1 was also co-expressed at ∼1 g L–1 or more and this serine protease inhibitor did not seem to inhibit furin processing of the pro-FIX. Fifteen F0 male piglets from 3 potential different integration sites were delivered and all of them were positive for all 3 genes. Four F0 males were chosen to breed with wild-type females, and 5 litters of F1 piglets were born. Of 63 F1 piglets, 22 were tri-transgenic and 3 were di-transgenic (only carrying FIX and Furin). Two F1 females were mated with wild-type males, are confirmed to be pregnant, and will be used to determine the expression level and bioactivity of the Factor IX protein in the milk. Funded by the NIH NCRR (RR018877) and R01 HL078944.

58 HISTONE DEACETYLASES INHIBITOR, SCRIPTAID, IS BENEFICIAL TO THE REPROGRAMMING OF SOMATIC NUCLEI FOLLOWING NUCLEAR TRANSFER

Somatic cell nuclear transfer (SCNT) is a promising technology with potential applications in both agriculture and regenerative medicine. The reprogramming of differentiated somatic nuclei into totipotent embryonic state following NT is not efficient and the mechanism is currently unknown. However, accumulating evidence suggests that faulty epigenetic reprogramming is likely to be the major cause of low success rates observed in all mammals produced through SCNT. It has been demonstrated that increased histone acetylation in reconstructed embryos by applying histone deacetylases inhibitor (HDACi) such as trychostatin A (TSA) significantly enhanced the developmental competence in several species in vitro and in vivo. However TSA has been known to be teratogenic. Compared with TSA, Scriptaid is a low toxic but more efficient HDACi (Su GH et al. 2000 Cancer Res. 60, 3137–3142). The objectives of this study were: 1) to investigate and optimize the application Scriptaid to the NT using Landrace fetal fibroblast cells (FFCs) as donor; 2) investigate the effect of increased histone acetylation on the developmental competence of reconstructed embryos from NIH mini inbred FFCs in vitro and in vivo. The reconstructed embryos were treated with Scriptaid at different concentrations (0 nm, 250 nm, 500 nm and 1000 nm) after activation for 14 to 16 h. IVF embryos without treatment were produced as an additional control. Developmental rates to the 2-cell and blastocyst stage were determined. Developmental potential was determined by transferring Day 1 NT zygotes to the oviducts of surrogates on the day of, or one day after, the onset of estrus. Experiments were repeated at least 3 times and data were analyzed with chi-square tests using SAS 6.12 program (SAS institute, Inc., Cary, NC, USA). The percentage blastocyst of cloned embryos using Landrace FFCs as donors treated with 500 nm Scriptaid was the highest and was significantly higher than untreated group (25% v. 11%, P < 0.05). Percent cleaved was not different among four treatment groups. We used 500 nm Scriptaid for 14 to 16 h after activation for all subsequent experiments. Developmental rate to the blastocyst stage was significantly increased in cloned embryos derived from NIH mini inbred FFCs after treating with Scriptaid (21% v. 9%, P < 0.05), while the blastocyst rate in IVF group was 30%. Embryo transfer (ET) results showed that 5/6 (Transferred embryos No. were 190, 109, 154, 174, 152, and 190, respectively) surrogates (83%) became pregnant resulting in 2 healthy piglets from 2 litters (recipients received 190 and 154 embryos, respectively) in the Scriptaid treatment group, while no pregnancies were obtained in the untreated group from 5 ET (Embryos transferred No. are 140, 163, 161, 151 and 151, respectively). These results suggest that 500 nm Scriptaid treatment following activation increase both the in vitro and in vivo development of porcine SCNT embryos from NIH mini inbred FFCs and the hyperacetylation might actually improve reprogramming of the somatic nuclei after NT. Funding from the National Institutes of Health National Center for Research Resources RR018877.

31 PORCINE SKIN-DERIVED STEM CELLS MAY BE A SUPERIOR SOURCE OF DONOR NUCLEI FOR EFFICIENT GENETIC MODIFICATION OF CLONED EMBRYOS

Somatic cell nuclear transfer (SCNT) in pigs relies primarily on the utilization of fetal-derived fibroblast cells, and the resultant clones tend to exhibit a significant level of phenotypic instability, which may be due to epigenetic reprogramming and/or genomic damage in the donor cells. In addition to the compromised phenotypic stability, production of transgenic clones through SCNT is inefficient, because the restricted lifespan of somatic donor cells in culture can be limiting when the genetic modification requires selection. In contrast, stem cells proliferate rapidly and do not undergo senescence at a high rate, so the selection process can be extended. Since there is no report of an embryonic stem cell line derived in the pig that could contribute to the germ line, we decided to investigate the utility of porcine skin-derived stem cells (SSCs). Porcine SSCs were isolated from the skin on the back of day 35 to 50 Yorkshire fetuses. The SSCs were cultured continually in SSCs medium (DMEM/F12 containing B-27, 20 ng mL–1 of epidermal growth factor, and 40 ng mL–1 of basic fibroblast growth factor) at 37.8°C, 5% CO2, 95% air. The SSCs expressed the neural progenitor marker nestin, as well as genes that are critical for pluripotency, such as Oct4 and Stat3. The SSCs proliferated actively in vitro and retained a normal karyotype after long-term culture. Electron microscopy revealed 2 distinct cell types within the spheres; elongated cells at the sphere periphery had invaginated nuclear envelopes and prominent nucleoli, and these cells displayed few, but large elongated mitochondria with transversal cristae as well as large cisternae of rough endoplasmic reticulum. In contrast, the cells in the center of the spheres were predominantly round-shaped, with a large round nucleus or cuboidal. The SSCs can be genetically modified with long-term positive selection, and 50 μg mL–1 G418 appeared to be an appropriate dose of G418 for selection of the transfected SSCs. Finally, NT embryos reconstructed with SSCs showed high rates of pre- and post-implantation development.The cell number in the blastocyst stage embryos derived from cloning with the SSC was significantly higher than those of the blastocysts derived from IVF (28.5 ± 1.9, 16.8 ± 4.0, respectively, P < 0.05), although there was no significant difference in blastocyst formation rates between these groups (21 to 25%). Three of the animals became pregnant in 4 surrogate gilts which received cloned embryos and reached to term. Two healthy male cloned piglets and 1 healthy female cloned piglet are genetically identical to the SSCs. Funding for this study was provided by the National Institutes of Health.

80 CHOLESTEROL-LOADED METHYL-BETA-CYCLODEXTRIN IMPROVES BOAR SPERMATOZOA CRYOPROTECTANT ADDITION AND REMOVAL TOLERANCE

Difficulties associated with the cryopreservation of boar sperm include their sensitivities to osmotic stresses and chilling sensitivity. We investigated the effects of cholesterol-loaded cyclodextrin (CLC) on boar sperm motility and membrane integrity following exposure to various osmolalities. Samples were collected using the gloved hand method from crossbred boars, and ejaculates having greater than 75% motility were extended 1:3 with Androhep (Minitube Inc., Verona, WI) for this study. Samples were centrifuged at 700g for 5 min, and the resulting pellets were resuspended to 1.2 × 108 cells mL–1 in Androhep. Samples were then treated with 0, 1.5, or 3.0 mg of CLC/1.2 × 108 cells mL–1 for 10 min at room temperature. In experiment 1, samples were aliquoted into 1.5-mL centrifuge tubes, centrifuged at 700g for 5 min and the sperm exposed to Dulbecco’s PBS at different osmolalities for 5 min before being returned to 300 mOsm by adding Dulbecco’s PBS solutions at differing osmolalities. After returning the sperm to isosmotic conditions, sperm motility was analyzed. In experiment 2, samples were treated as in experiment 1 and following exposure to the various osmolalities, sperm were stained with Alexa 488-PNA and propidium iodide to determine sperm membrane integrity. Ten thousand sperm per treatment were analyzed by flow cytometry. Data were analyzed by standard ANOVA. The CLC-treated sperm (normalized means ± SEM; 33 ± 16, 80 ± 8, 86 ± 5, 100, 64 ± 4, 7 ± 3, 0 ± 0, respectively) exhibited greater percentages of motile cells following hypo-isosmotic exposure than control sperm (4 ± 1.6, 33 ± 9.6, 84 ± 7.1, 100, 37 ± 5.5, 3 ± 1.6, 0 ± 0, respectively), and there was a tendency for CLC-treated sperm (P = 0.0225) to maintain motility following hyper-isosmotic exposure. In addition, CLC-treated sperm (87 ± 4, 93 ± 1, 95 ± 1, 93 ± 2, 88 ± 4, 83 ± 3, 41 ± 9, respectively; P < 0.05) maintained greater percentages of membrane integrity following treatment with anisosmotic solutions compared with controls (29 ± 8, 63 ± 10, 81 ± 7, 92 ± 3, 73 ± 8, 44 ± 5, 21 ± 9, respectively). Using a combination of these osmotic tolerance data with previously published boar sperm membrane permeability characteristics, we mathematically modeled the number of steps needed for the addition or removal of cryoprotectants. Computer simulations indicate that an abrupt addition of 1 m glycerol will cause boar sperm to exceed their osmotic tolerance limits unless they are treated with 3 mg of CLC. Moreover, the addition of 1 m EG causes boar sperm to exceed all osmotic tolerance limits and therefore, the addition and removal of EG requires multiple-step protocols. However, the addition and removal of 1 m DMSO maintains volume excursions well within the osmotic tolerance limits with the addition of cholesterol (1.5 and 3 mg). Empirical data for addition of CPA have shown similar results as seen with the computer simulation. These data support the hypothesis that adding cholesterol to porcine sperm broadens their osmotic tolerance limits and potentially provide a mechanism to increase post-thaw survival of porcine sperm.

33 PRE-AND POST-IMPLANTATION DEVELOPMENT OF EMBRYOS CLONED FROM PORCINE SKIN-DERIVED SPHERE STEM CELLS

Although transgenic animals have been successfully cloned, the process is still inefficient. One of the limitations is the use of somatic donor cells that have a limited lifespan. If a genetic modification is made, the selection process must be initiated and completed rapidly or the cells will undergo senescence. Identification of a stem cell that would proliferate rapidly and not undergo senescence would prove to be very valuable. Here we report attempts at cloning by using porcine skin-derived sphere stem cells to determine if they are a suitable donor cell type. Skin-derived stem cells were isolated from fetal skin and express the neural progenitor marker NES, as well as genes that may be critical for pluripotency such as POU5F1 and STAT3. The skin-derived stem cells proliferate rapidly in vitro and retain a normal karyotype after long-term culture. In the present study, skin-derived stem cells were cultured and frozen in liquid nitrogen from passage 1 to passage 8. To investigate the developmental potential of the skin-derived stem cells, we performed nuclear transfer (NT) and compared their preimplantation developmental efficiency to that of the embryos derived from in vitro fertilization (IVF). Cumulus–oocyte complexes (COCs) were aspirated from antral follicles of ovaries from prepubertal gilts. Approximately, groups of 50-70 COCs were matured in vitro in 500 µL TCM-199 per culture well for 40–44 h at 38.5�C, in a humidified atmosphere of 5% CO2 in air. The donor cells were thawed and cultured one day before NT; skin-derived stem cells were pipetted vigorously in PBS-EDTA to isolate individual cells. For IVF, cryopreserved ejaculated spermatozoa were thawed and washed and then resuspended with fertilization medium (mTBM). The MII oocytes were co-incubated with sperm for 6 h, and then transferred to PZM3 and cultured. For NT and IVF, respectively, the percent cleavage at 48 h in PZM3 was 64.9 � 8.2% (169/208) and 62.1 � 3.1% (94/184) (P > 0.05), the percent blastocysts after 6 days was 21.5 � 5.8% (53/208) and 25.2 � 3.4% (46/184) (P > 0.05), and the number of nuclei per blastocyst was 28.5 � 1.9 (NT, maximum was 58) and 16.8 � 4.0 (IVF, maximum was 31) (P < 0.05). To determine development post-implantation, some cloned embryos were cultured in PZM3 for 15.5 h and an average of 112 cloned embryos were transferred to the oviducts of four naturally cycling gilts on Day 0–1 of standing estrus. Three of the animals were pregnant: one of them farrowed two male piglets on August 14th, with the other two due on September 8th and 9th. Future studies will involve performing NT and ET on skin-derived stem cells from a higher passage number to determine if they would be suitable for genetic modification prior to NT.

5 TRANSCRIPTIONAL PROFILING OF PIG IN IN VIVO, IN VITRO-FERTILIZED, AND NUCLEAR TRANSFER-DERIVED BLASTOCYSTS AND THE DONOR SOMATIC CELL LINE

The objective of this study was to perform transcriptional profiling between in vivo (IVV), in vitro-fertilized (IVF), and nuclear transfer (NT) blastocyst stage embryos, along with the donor cell line used for NT, in order to identify candidate genes that may contribute to the suboptimal phenotypes of cloned pigs. IVV samples were collected surgically 8 days post-estrus. IVF and NT embryos were transferred into recipient gilts on Day 0 or 1 of estrus and were subsequently collected 6 days later by uterine flush. NT oocytes were activated using one of three methods:NT-1 (electrical activation/fusion), NT-2 (electrical activation/fusion + treatment with proteasomal inhibitor MG 132), or NT-3 (electrical fusion + thimerosal/dithiothreitol (DTT) activation). NT was performed by using pCAG-EGFP positive fetal fibroblast cells to avoid collection of parthenogenetic blastocysts. Donor cells were collected post-NT in pools of 100. Three pools of 10–15 embryos were collected for each treatment. Each pool was analyzed twice, resulting in three biological and two technical replicates. A reference design was used and the reference RNA represented a pool of both reproductive and non-reproductive tissues. Total RNA was isolated by using Trizol (Invitrogen, Carlsbad, CA, USA) and amplified by using an Ovation Ribo-SPIA linear amplification kit (NuGEN Technologies, Inc., San Carlos, CA, USA). Amplified cDNA from blastocysts or cells was labeled with Cy5 and compared to cDNA from the reference sample labeled with Cy3. The cDNAs were hybridized to an in-house printed pig reproductive tissue-specific 19 968 spot cDNA microarray. Microarray images were acquired using a GenePix� 4000B scanner. Spot quality was assessed and results files were constructed using GenePix Pro 4.0. Lowess normalization and analysis was performed in Genespring 7.3.1 (Agilent Technologies, Inc., Palo Alto, CA, USA). Two comparisons were made: IVF versus IVV, and a comparison of all treatments IVV, IVF, NT-1, NT-2, NT-3, and donor cell line. ANOVA (P < 0.05) was performed with the Benjamini and Hochberg False Discovery Rate multiple correction test. The IVF and IVV comparison resulted in 0 differentially detected cDNAs. The IVV, IVF, NT-1, NT-2, NT-3, and donor cell line comparison detected 1477 differentially detected cDNAs, including heat shock proteins (HSPD1 and HSPE1), which are lowly expressed in the donor cell line, and X inactive-specific transcript (XIST), which has higher expression in IVV and IVF compared to that in NT blastocysts. A standard correlation was performed on both comparisons. The R2 value for the IVV and IVF comparison was 0.892, while the R2 value for all samples was 0.716. These results illustrate that IVV and IVF blastocysts, developed within the uterus, are nearly identical. However, a comparison of blastocysts in all treatments including NT and the donor cell line revealed many differentially expressed genes that can be further evaluated for biological function and usefulness as potential markers of quality embryo development after NT.

Production of endothelial nitric oxide synthase (eNOS) over-expressing piglets

Vascular function, vascular structure, and homeostasis are thought to be regulated in part by nitric oxide (NO) released by endothelial cell nitric oxide synthase (eNOS), and NO released by eNOS plays an important role in modulating metabolism of skeletal and cardiac muscle in health and disease. The pig is an optimal model for human diseases because of the large number of important similarities between the genomic, metabolic and cardiovascular systems of pigs and humans. To gain a better understanding of cardiovascular regulation by eNOS we produced pigs carrying an endogenous eNOS gene driven by a Tie-2 promoter and tagged with a V5 His tag. Nuclear transfer was conducted to create these animals and the effects of two different oocyte activation treatments and two different culture systems were examined. Donor cells were electrically fused to the recipient oocytes. Electrical fusion/activation (1 mM calcium in mannitol: Treatment 1) and electrical fusion (0.1 mM calcium in mannitol)/chemical activation (200 microM Thimerosal for 10 min followed by 8 mM DTT for 30 min: Treatment 2) were used. Embryos were surgically transferred to the oviducts of gilts that exhibited estrus on the day of fusion or the day of transfer. Two cloned transgenic piglets were born from Treatment 1 and low oxygen, and another two from Treatment 2 and normal oxygen. PCR, RT-PCR, Western blotting and immunohistochemistry confirmed that the pigs were transgenic, made message, made the fusion protein and that the fusion protein localized to the endothelial cells of placental vasculature from the conceptuses as did the endogenous eNOS. Thus both activation conditions and culture systems are compatible with development to term. These pigs will serve as the founders for a colony of miniature pigs that will help to elucidate the function of eNOS in regulating muscle metabolism and the cardiorespiratory system.

374 PRODUCTION OF TRANSGENIC CLONED PIGLETS BY USING PORCINE FETAL FIBROBLASTS OVEREXPRESSING ENDOTHELIAL NITRIC OXIDE SYNTHASE

Vascular function, vascular structure, and homeostasis are thought to be regulated in part by endothelial nitric oxide synthase (eNOS). In addition, eNOS plays an important role in modulating metabolism of skeletal and cardiac muscle in health and disease. The pig is an optimal model for human diseases because of the large number of important similarities between the genomic, metabolism, and cardiovascular systems of pigs and humans. The main goal of this study was to produce pigs that carry an endogenous eNOS gene driven by a Tie-2 promoter and tagged with a V5 His tag so that a better understanding of cardiovascular regulation by eNOS can be gained. Nuclear transfer was conducted to create these animals, and the effects of two different oocyte activation treatments and two different culture systems were examined. Mature oocytes were purchased from BoMed, Inc. (Maidson, WI, USA) and enucleated by micromanipulation. Donor cells were injected into the perivitelline space and electrically fused to the recipient oocyte. Treatment 1 consisted of electrical fusion/activation in 1 mM calcium in mannitol; Treatment 2 consisted of electrical fusion in 0.1 mM calcium in mannitol, followed by chemical activation in 200 �M thimerosal for 10 min followed by 8 mM DTT for 30 min. The fusion rate (71% vs. 82%) was lower (P < 0.0001) in Treatment 2 than in Treatment 1. For those oocytes that fused, the cleavage rates (5.9% vs. 0.4%) at 14-18 h were higher (P < 0.0001) for Treatment 2. Fused oocytes were cultured for 12-18 h in 5% O2, 5% CO2, 90% N2 (low oxygen) or 5% CO2 in air (normal oxygen), and were then surgically transferred to the oviducts of gilts that exhibited estrus on the day of fusion or the day of transfer. In February four cloned transgenic piglets were born (birth weights were 495, 595, 965, and 685 g). Two were from Treatment 1 and low oxygen, and the other two were from Treatment 2 and normal oxygen, and all are currently healthy. PCR, RT-PCR, and Western blotting analysis confirmed that the pigs were transgenic, made message, and made the fusion protein. Immunohistochemistry confirmed that the fusion protein localized in the endothelial cells of the placental vasculature from the conceptuses as did the endogenous eNOS. In addition to the transgenic males, four wild-type females were born (birth weights were 585 (this one died on Day 4) 445, 930, and 585 g). All four were from Treatment 2 and low oxygen, and three are healthy. In conclusion, viable piglets were produced from both Treatments 1 and 2, as well as in both high and low oxygen conditions. Thus, both activation conditions and culture systems are compatible with development to term. These pigs will serve as the founders for a colony of miniature pigs that will help to elucidate the function of eNOS in regulating muscle metabolism and the cardiorespiratory system. This work was funded by a grant from the NIH RR18276 and Food for the 21st Century.

381 PRODUCTION OF A TRANSGENIC PIGLET BY A NEW SPERM INJECTION TECHNIQUE

The technique for intracytoplasmic sperm injection (ICSI) has, until now, focused on scoring the tail of the sperm prior to catching and aspiration into the injection pipette. This is in spite of the fact that damage to the head would more closely simulate what occurs during normal fertilization. In addition, to aid in visualizing the injection process so that a reduced volume can be injected, the oocyte is generally centrifuged to clear a portion of the cytoplasm. Thus, with conventional ICSI, the sperm are immobilized with polyvinylpyrrolidone, repeatedly frozen and thawed, treated with DTT or Triton X-100, and severed between the head and tail; the oocyte is centrifuged or activated. All of the above treatments are designed to compensate for the intrinsic defects in conventional ICSI. Our objective was to use a modified ICSI procedure whereby aggressively motile sperm were captured onto the broken tip of an injection pipette and then injected into noncentrifuged oocytes. Damage to the head of the sperm occurred on the pipette or while pushed through the zona pellucida. These procedures are based on the work of Yong et al. 2003 Hum. Reprod. 18, 2390, where they achieved an improvement in development in vitro as compared to conventional methods. Ovaries were collected from prepubertal gilts, and oocytes were aspirated and matured in vitro. Sperm were collected from a transgenic boar carrying the green fluorescent protein (GFP) and frozen. After thawing, aggressively motile sperm were captured and injected through the zona pellucida and into the cytoplasm of the in vitro-matured oocytes. A total of 452 injected oocytes (43-171 oocytes per recipient) were surgically transferred into the oviduct of six surrogate gilts. Two gilts (33%) became pregnant. One gave birth to a healthy male piglet. GFP expression was observed in the nose and hooves by direct epifluorescent examination of the newborn piglet. This pattern of GFP expression is identical to that in non-ICSI-derived GFP pigs in this line. This result showed for the first time that this new sperm injection technique could be used for production of a viable transgenic piglet using in vitro-matured oocytes and frozen-thawed sperm.

101 CRYOPRESERVATION OF PORCINE EMBRYOS DERIVED FROM SOMATIC CELL NUCLEAR TRANSFER

In the production of cloned pigs, a large number of nuclear transfer (NT) embryos generally need to be transferred into a single surrogate. Thus, attempts to conduct embryo transfer can be frustrating when either a synchronized surrogate is not available, or enough NT embryos are not produced. This problem would be solved if one could cryopreserve the porcine nuclear transfer embryos. Cryopreservation of porcine embryos has been successful only for in vivo-derived embryos. In vitro-derived porcine embryos are sensitive to chilling, and this sensitivity has been attributed to the lipid droplets in the cytoplasm. In previous reports, the viability of cyropreserved embryos was improved by removal of lipid drops from the cytoplasm. Therefore we designed a procedure to cryopreserve cloned blastocysts by a combination of the open pulled straw (OPS) vitrification method with removal of lipid drops from the oocyte. In vitro-matured MII oocytes were enucleated, and centrifuged (10 000 rpm, 5 min) to polarize the lipid droplets. This was followed by removal of the polarized lipid droplets and transfer of a donor fetal-derived fibroblast cell into the perivitelline space by micromanipulation. After electrical activation and fusion, the NT embryos were cultured in PZM-3 medium with 4 mg/mL BSA. Day 5 and Day 6 blastocysts (manipulation day was Day 0) were vitrified by equilibration with 25 mM HEPES-buffered TCM-199 containing 10% ethylene glycol, 10% DMSO, and 20% fetal calf serum for 2 min, followed by exposure to 20% ethylene glycol and 20% DMSO. Embryos were loaded into an OPS straw and immediately plunged into liquid nitrogen. The process from exposure of embryos to vitrification solution to plunging was 25–30 s. Embryos were thawed by immersing the end of the OPS straw in 0.3 M sucrose in which embryos were kept for 5 min, and then in 0.2 M sucrose for 5 min. Some embryos were cultured in PZM-3 for 12 h to determine the percentage and cell number of re-expanded blastocysts. The others were transferred to the uterus of a surrogate gilt within 3 h of thawing. Lipid removal appeared to have no harmful effect on embryo development and cell number of the blastocysts. Interestingly, a higher blastocyst percentage (28.8%, 178/619) was obtained with NT embryos from which the lipid had been removed as compared to normal NT (19.6%, 44/225; P < 0.01). The cell number (31.2 ± 7.7) of re-expanded blastocysts in the delipation group was comparable with normal NT blastocysts (33.6 ± 14.1, P = 0.33). The survival rate of blastocysts after freezing and thawing was enhanced after delipation (delipation group: 66.7%, 14/21; normal NT group: 21.9%, 9/42; P < 0.01). Two hundred and fourteen delipatized NT blastocysts were transferred to four surrogates after freezing and thawing. Three of the surrogates showed a delayed estrus cycle and one is still pregnant as confirmed by ultrasound scanning. We show that the combination of the OPS vitrification method with removal of lipid drops of oocyte cytoplasm might be an efficient way to cryopreserve porcine NT blastocysts. Funding for this project was from the NIH HL51670 and RR018877 and Food for the 21st Century.

316 SUPPLEMENTAL CYSTEINE PRESENCE DURING THE DECONDENSATION OF SPERM CHROMATIN IMPROVES FERTILIZATION AND BLASTOCYST FORMATION AFTER INTRACYTOPLASMIC SPERM INJECTION IN PIGS

The effect of a cysteine supplement in culture media for oocytes matured in vitro after intracytoplasmic sperm injection (ICSI) on fertilization and embryo development were examined. In the first experiment, sperm injected oocytes were cultured in NCSU23 (control) or NCSU23 supplemented with 0.57–3.71 mM cysteine (0.57–3.71 Cys) for 12 h after ICSI, and then fixed to observe pronuclear formation. In the second experiment, to examine the appropriate duration time of cysteine supplement to support fertilization, sperm-injected oocytes were transferred into NCSU23 following culture in NCSU23 supplemented with 1.71 mM cysteine for 1, 2, 3, 4, 5, 6, or 9 h after ICSI, and then fixed at 12 h. At the same time, morphological changes of sperm heads in oocytes cultured in NCSU23 (1.71 Cys) were observed. In the third experiment, to examine the developmental ability of ICSI embryos fertilized in NCSU23 (1.71 Cys), sperm injected oocytes were cultured under the following conditions for a total of 168 h; NCSU23 (control), NCSU23 (1.71 Cys) for 3 h followed by transfer into NCSU23 (1.71 Cys-3 h), NCSU23 (1.71 Cys) for 12 h followed by transfer in NCSU23 (1.71 Cys-12 h), or NCSU23 (1.71 Cys) (1.71 Cys). Data were pooled from at least five replicates. Values in each replicate were analyzed using one-way ANOVA. Significance of differences was assessed by Student's t-test. Culture with several concentrations of cysteine for 12 h showed that 1.71–3.71 Cys significantly (P < 0.05) increased fertilization rates above controls or 0.57 Cys (56–60%, 35%, or 48%, respectively). Culture for several duration times with 1.71 Cys showed that fertilization rates increased as the duration time increased to 3 h which was significantly (P < 0.05) higher than controls (68% and 34%, respectively), and culture times of greater than 3 h did not increase fertilization rates (58–68%). At 3 h, 59% of oocytes cultured in NCSU23 (1.71 Cys) had decondensed sperm heads and 16% of those had enlarged sperm heads. At 6 h, 50% of oocytes cultured in NCSU23 (1.71 Cys) had male pronuclei. Blastocyst formation rate in 1.71 Cys-3 h was 29% which was higher than for controls (20%). On the other hand, 1.71 Cys-12 h cultures showed low blastocyst formation rates, and continuous culture in NCSU23 (1.71 Cys) for 168 h (1.71 Cys) significantly (P < 0.05) decreased blastocyst rates (16% and 7%, respectively). We found that the supplement of 1.71 mM cysteine to NCSU23 for culture of oocytes after ICSI improved fertilization rates. However, the presence of 1.71 mM cysteine for 12 h or longer after ICSI had adverse effects on embryo development. Since 1.71 mM cysteine supplement for 3 h after ICSI improved blastocyst formation with the same fertilization rates as when supplemented for 12 h, the presence of cysteine only during the decondensation of sperm chromatin was found to be associated with the improvement of fertilization and also the promotion of blastocyst formation.

Primary drug-resistance in HIV-positive patients on initiation of first-line antiretroviral therapy in Germany

BACKGROUND

Resistance against antiretroviral drugs in previously untreated HIV-infected persons is of growing relevance. The aim of the study is to determine the prevalence of resistance-associated mutations in this patient group.

METHODS

In a prospective multicenter-study in Nordrhein-Westfalen, Germany, genotypic resistance testing was performed in untreated HIV-positive patients before administration of first-line highly active antiretroviral therapy (HAART).

RESULTS

Between January 2001 and August 2002 resistance testing was performed in 184 therapy-naive individuals. HAART was initiated in 143 patients, who were included into the study. 70.6 % were males, mean age was 39 years, mean duration of diagnosis of HIV-infection was 1.5 years. The proportion of cases at CDC stage C was 45.4%, mean CD4-cell count was 199 /ml, mean viral load was 206,855 copies/ml. Resistance-associated mutations were detected in 20 patients (14.0%). 10.5% showed mutations indicating nucleoside reverse transcriptase inhibitor- (NRTI) resistance (M41L, E44D, D67N, T69D/N, L74V, V118I, M184V, L210W, K219Q), 2.8% showed non-nucleoside reverse transcriptase inhibitor (NNRTI) resistance (K103N, V108I, Y181C), and 2.1% showed protease-inhibitor- (PI) associated resistance (V82A, L90M), respectively. Multi-class-resistance was found in 2.1%, mutations indicating revertant variants of resistant strains were found in 4.2% (T215C/E/L/S). 86.7% of the isolates showed secondary mutations in the protease gene. No significant difference in the distribution of the parameters age, sex, duration of HIV diagnosis, CDC stage, CD4-cell count, and viral load, between groups with and without resistance was identified.

CONCLUSION

The prevalence of primary resistant virus strains can be estimated at 14% in chronically infected HAART-naive HIV-patients in Germany. The majority of these cases show NRTI-associated resistance. Resistance against NNRTI or PI as well as multi-class-resistance is of low prevalence. No risk factor of predictive value can be identified for the diagnosis of resistance mutations in the individual. In conclusion, routine genotypic resistance testing in untreated HIV-positive patients should be performed before administration of first-line HAART in this region.

Mosaic gene expression in nuclear transfer-derived embryos and the production of cloned transgenic pigs from ear-derived fibroblasts

Genetically modified domestic animals have many potential applications ranging from basic research to production agriculture. One of the goals in transgenic animal production schemes is to reliably predict the expression pattern of the foreign gene. Establishing a method to screen genetically modified embryos for transgene expression before transfer to surrogates may improve the likelihood of producing offspring with the desired expression pattern. In order to determine how transgene expression may be regulated in the early embryo, we generated porcine embryos from two distinct genetically modified cell lines by using the nuclear transfer (NT) technique. Both cell lines expressed the enhanced green fluorescent protein (eGFP); the first was a fibroblast cell line derived from the skin of a newborn pig that expressed eGFP, whereas the second was a fetal derived fibroblast cell line into which the eGFP gene was introduced by a retroviral vector. The reconstructed embryos were activated by electrical pulses and cultured in NCSU23. Although the in vitro developmental ability of each group of NT embryos was not different, the eGFP expression pattern was different. All embryos produced from the transduced fetal cell line fluoresced, but only 26% of the embryos generated from the newborn cell line fluoresced, and among those that did express eGFP, more than half had a mosaic expression pattern. This was unexpected because the fetal cell line was not clonally selected, and each cell had potentially different sites of integration. Embryos generated from the newborn cell line were surgically transferred to five surrogate gilts. One gilt delivered four female piglets, all of which expressed eGFP, and all had microsatellites identical to the donor. Here we demonstrate that transgene expression in all the blastomeres of an NT embryo is not uniform. In addition, transgene expression in a genetically manipulated embryo may not be an accurate indicator of expression in the resulting offspring.

Long-term efficacy and safety of ritonavir/indinavir at 400/400 mg twice a day in combination with two nucleoside reverse transcriptase inhibitors as first line antiretroviral therapy

OBJECTIVE

To determine the long-term antiretroviral efficacy and tolerability of dual protease inhibitor (PI) therapy with indinavir (IDV)/ritonavir (RTV) at 400/400 mg twice a day (BID) in combination with two nucleoside reverse trancriptase inhibitors (NRTIs).

DESIGN AND METHODS

In an open-label, uncontrolled multicentre clinical trial, antiretroviral therapy naive patients (n = 93) with a high median baseline HIV-1 RNA level of 210 000 copies/mL (range 17 000-2 943 000) and a median CD4 cell count of 195 copies/microL (range 4-656 copies/microL) were started on a regimen of either zidovudine (ZDV)/lamivudine (3TC) (49%), stavudine (d4T)/3TC (38%) or d4T/didanosine (ddI) (14%) plus RTV and IDV, each at 400 mg BID. CD4 cell counts and HIV RNA were determined at 4-week intervals for a duration of 72 weeks. Statistical analysis was performed on treatment as well as by intent to treat, where missing values were counted as failures.

RESULTS

HIV RNA levels below the limit of detection were achieved in 59.5% (< 80 copies/mL) and 63% (< 500 copies/mL) of patients according to the intent to treat analysis at week 72. In the on treatment analysis, the proportion of patients reaching an undetectable viral load was 94.5% (< 80 copies/mL) and 100% (< 500 copies/mL), respectively. Apart from diarrhoea and nausea, serum lipid abnormalities were identified as the most prominent adverse reaction. No cases of nephrotoxicity occurred during the entire observation period of 72 weeks.

CONCLUSIONS

Our results demonstrate that quadruple therapy with RTV/IDV and two NRTIs induces potent, durable and safe HIV suppression and might be particularly beneficial as a first line therapy for patients with a high baseline viral load.

Production of nuclear transfer-derived swine that express the enhanced green fluorescent protein

The ability to add or delete specific genes in swine will likely provide considerable benefits not just to agriculture but also to medicine, where pigs have potential as models for human disease and as organ donors. Here we have transferred nuclei from a genetically modified fibroblast cell line to porcine oocytes, matured in vitro under defined culture conditions, to create piglets expressing enhanced green fluorescent protein. The nuclear transfer-derived piglets were of normal size, although some mild symptoms of "large offspring syndrome" were evident. These experiments represent a next step towards creating swine with more useful genetic modifications.

Development and viability of pig oocytes matured in a protein-free medium containing epidermal growth factor

This study examined the ability of epidermal growth factor (EGF) to improve the developmental competence of pig oocytes matured in a protein-free (PF) in vitro maturation (IVM) system. Oocyte maturation was done in one of three media: 1. PF-TCM: tissue culture medium (TCM) 199 + 0.1% polyvinylalcohol (PVA); 2. PF-TCM+EGF: PF-TCM + 10 ng/ml EGF; and 3. +ve CONT: North Carolina State University (NCSU) 23 medium + 10% porcine follicular fluid. All media contained 0.57 mM cysteine. Hormonal supplements, 0.5 microg/mL LH and 0.5 microg/mL FSH, were present only for the first half (20 to 22 h) of the culture period. After maturation, oocytes were co-incubated with frozen-thawed spermatozoa for 5 to 6 h and transferred to embryo culture medium, NCSU 23 containing 0.4% BSA, for 144 h. In Experiment 1, differences in cumulus expansion were observed for oocytes matured in +ve CONT (Category 4), PF-TCM (Category 2) and PF-TCM+EGF (Category 3). However, no significant differences in nuclear maturation to metaphase II stage were observed. In Experiment 2, no differences in fertilization parameters were observed. Significant (P < 0.01) differences in cleavage rates were observed among the three media for a proportion of the oocytes matured (52, 60 and 69% in PF-TCM, PF-TCM+EGF, and +ve CONT, respectively). Oocytes matured in PF-TCM showed the lowest (P < 0.01) blastocyst development (22%). However, the same rate of blastocyst development was obtained for +ve CONT (37%) and PF-TCM+EGF (37%). Blastocyst cell numbers were significantly higher when oocytes were matured in the presence of EGF (26 vs. 37 to 41). In Experiment 3, oocytes matured in PF-TCM+EGF had a significantly (P < 0.05) higher intracellular glutathione (GSH) concentration (5.9 vs. 11.4 pmol/oocyte) compared with PF-TCM. Twenty-two of 25 embryo transfer recipients became pregnant (Experiment 4). Four animals returned to estrus in within 60 days. Six pregnant animals slaughtered at 26 to 45 days had 43 fetuses (range: 4 to 12) and the remaining 12 animals farrowed 82 piglets (range: 3 to 12). These results indicate that EGF enhances the developmental competence of pig oocytes matured in a protein-free culture medium which is correlated with higher GSH level in oocytes. Birth of piglets indicate that embryos derived from oocytes matured in the presence of EGF are viable.

Efficacy and safety of twice daily first-line ritonavir/indinavir plus double nucleoside combination therapy in HIV-infected individuals. German Ritonavir/Indinavir Study Group

OBJECTIVE

To evaluate the virological efficacy and safety of quadruple therapy with two nucleoside analogues and ritonavir (400 mg twice daily) plus indinavir (400 mg twice daily) combination in antiretroviral therapy-naive patients.

DESIGN AND METHODS

An open-label, uncontrolled multicentre trial. Antiretroviral therapy-naive patients (n = 90) with high median baseline HIV RNA levels of 220,000 copies/ml (range, 36,000-2,943,000 copies/ml) and median CD4 cell count of 189 x 10(6)/l (range, 4-656 x 10(6)/l) were started on a twice daily regimen of either zidovudine/lamivudine (49%), stavudine/lamivudine (38%) or stavudine/didanosine (13%) plus ritonavir 400 mg twice daily and indinavir 400 mg twice daily combination therapy. CD4 cell counts and HIV RNA were determined at weeks 0, 4, 8, 12, 16, 20, and 24. Statistical analysis was performed on treatment as well as intent-to-treat, where missing values were accounted for as failure.

RESULTS

In the intent-to-treat analysis at week 24, the proportion of patients with HIV RNA of < 500 copies/ml, and < 80 copies/ml was 86.7% and 71.1%, respectively. In the on-treatment analysis at week 24, 80.0% of patients had undetectable viral load in the ultrasensitive assay (< 80 copies/ml; n = 80). The quadruple therapy was well tolerated except for mild diarrhoea, initial nausea and increased triglyceride levels. Treatment was stopped in seven (7.7%) patients because of adverse events and three (3.3%) were lost to follow-up.

CONCLUSIONS

Our preliminary data suggest that the protease inhibitor combination ritonavir/indinavir plus double nucleoside therapy appears to be effective and safe in short-term treatment (up to 24 weeks).

Presence of epidermal growth factor during in vitro maturation of pig oocytes and embryo culture can modulate blastocyst development after in vitro fertilization

The present study examined the effect of epidermal growth factor (EGF) during in vitro maturation (IVM) and embryo culture on blastocyst development in the pig. In experiment 1, cumulus oocyte complexes were cultured in North Carolina State University (NCSU) 23 medium containing porcine follicular fluid, cysteine, hormonal supplements, and with or without EGF (0-40 ng/ml) for 20-22 hr. They then were cultured for an additional 20-22 hr without hormones. After maturation, cumulus-free oocytes were co-incubated with frozen-thawed spermatozoa for 5-6 hr. Putative embryos were transferred to NCSU 23 containing 0.4% BSA and cultured for 144 hr. In experiment 2, oocytes were matured in medium containing 10 ng/ml EGF, inseminated, and putative embryos were cultured in the presence of 0-40 ng/ml EGF. In experiment 3, oocytes were cultured in the presence of 0, 10 and 40 ng/ml EGF to examine the kinetics of meiotic maturation. In experiment 4, 2- to 4-cell and 8-cell to morula stage embryos derived from oocytes matured with 10 ng/ml EGF were transferred to the oviduct and uterus, respectively, of each of three recipient gilts (3 and 4 days post-estrus, respectively). The presence or absence of EGF during IVM did not affect cumulus expansion, nuclear maturation, fertilization parameters, or cleavage rate. However, compared to no addition (21%), presence of 1 (33%) and 10 ng/ml EGF (42%) during IVM increased (P < 0.01) the rate of blastocyst development in a concentration-dependent manner. Compared to 10 ng/ml EGF, higher concentrations (20 and 40 ng/ml) reduced (P < 0.01) blastocyst development in a concentration-dependent manner (35% and 24%, respectively). No difference was observed between no addition and 40 ng/ml EGF (22%). Compared to no addition and 10 ng/ml EGF, a significantly (P < 0.001) higher proportion (25% vs. 55%) of oocytes reached metaphase II stage 33 hr after IVM with 40 ng/ml EGF. However, no difference was observed at 44 hr. Transfer of embryos to six recipient gilts resulted in three pregnancies and birth of 18 piglets. The results show that EGF at certain concentrations in IVM medium can influence the developmental competence of oocytes. However, addition of EGF during the culture of pig embryos derived from oocytes matured in the presence of EGF is without effect. Birth of piglets provides evidence that embryos derived from oocytes matured in a medium containing EGF are viable.

Birth of piglets preselected for gender following in vitro fertilization of in vitro matured pig oocytes by X and Y chromosome bearing spermatozoa sorted by high speed flow cytometry

The present study examined the ability to establish pregnancies after transfer of pig embryos derived from in vitro fertilization (IVF) of in vitro matured (IVM) oocytes by X and Y chromosome-bearing spermatozoa sorted by flow cytometry. Cumulus-oocyte complexes (COC) were cultured in BSA-free NCSU-23 medium containing porcine follicular fluid (10%), cysteine (0.1 mg/mL), epidermal growth factor (10 ng/mL), LH (0.5 microgram/mL) and FSH (0.5 microgram/mL) for 22 h, then the oocytes were cultured without hormonal supplements for an additional 22 h. Boar semen was collected and prepared by flow cytometry sorting of X and Y chromosome bearing spermatozoa. After IVM, cumulus-free oocytes were co-incubated with sorted X or Y spermatozoa (2 x 10(4)/mL) for 6 to 7 h in modified Tris-buffered medium containing 2.5 mM caffeine and 0.4% BSA. After IVF, putative embryos were transferred to NCSU-23 medium containing 0.4% BSA for culture. A portion of the oocytes was fixed 12 h after IVF, the remainder were cultured up to 96 h. At 96 h after IVF, 8-cell to morula stage embryos (n = 30 to 35) from each gender were surgically transferred to the uterus of recipient gilts. Insemination of IVM pig oocytes with X- or Y-bearing sperm cells did not influence the rate of penetration (67 vs 80%), polyspermy (40 vs 53%), male pronuclear formation (95 vs 96%), or mean number of spermatozoa per oocyte (1.6 vs 1.6), respectively. Furthermore, no difference was observed between cleavage rates at 48 h after IVF (X, 49 vs Y, 45%). Transfer of embryos derived from X-bearing spermatozoa to 18 recipients resulted in 5 pregnancies and delivery of 23 females and 1 male piglet. Similarly, transfer of embryos derived from Y-bearing sperm cells to 10 recipients resulted in 3 pregnancies, with 9 male piglets delivered. The results show that X- and Y-bearing spermatozoa sorted using USDA sperm sexing technology can be successfully used in an IVM-IVF system to obtain piglets of a predetermined sex.

Coculture with follicular shell pieces can enhance the developmental competence of pig oocytes after in vitro fertilization: relevance to intracellular glutathione

The present study examined the effect of follicular shell pieces (FSP) during in vitro maturation (IVM) of porcine oocytes on 1) in vitro fertilization (IVF) parameters, 2) subsequent embryo development, 3) oocyte glutathione (GSH) concentration, and 4) viability after embryo transfer. Cumulus-oocyte complexes were cultured in North Carolina State University (NCSU) 23 medium containing porcine follicular fluid, cysteine, and hormonal supplements and with or without FSP for 20-22 h. They were then cultured in the same medium but without hormonal supplements for an additional 20-22 h. After culture, cumulus-free oocytes were coincubated with frozen-thawed spermatozoa for 5-6 h. Putative zygotes were transferred to NCSU 23 containing 0.4% BSA and cultured for 144 h. In comparisons between the presence and absence of FSP, no differences were observed in fertilization parameters. At 48 h, no mean differences were found in cleavage rates. However, at 144 h, the proportion of embryos that developed to the blastocyst stage was significantly (p < 0.01) higher (18% vs. 36%) for oocytes cocultured with FSP. A significantly (p < 0.05) higher GSH concentration was found in oocytes matured with FSP as determined by dithionitrobenzoic acid-glutathione disulfide (DTNB-GSSG) reductase recycling assay. Transfer of embryos to 9 recipients resulted in 5 pregnancies with the birth of 18 live piglets. The results provide clear evidence of the beneficial effect of FSP during IVM of pig oocytes cultured in the presence of cysteine on subsequent embryo development to the blastocyst stage. The birth of piglets confirms the viability of IVM-IVF-derived embryos.

Technical note: porcine non-surgical embryo transfer

The cervix is a barrier for transferring porcine embryos non-surgically. A non-surgical embryo transfer instrument composed of four parts has been developed that allows the delivery of embryos into the lumen of one uterine horn. Part 1, a modified artificial insemination spirette, is used to produce a cervical lock and to assist in manipulating Part 2 through the cervix. Part 2 is made of stainless steel tubing with a unique curved tip that can be manipulated through the folds of the cervix. Part 3 is a testing bar to ensure that the tip of Part 2 reaches the bifurcation of the uterus. Part 4, a disposable tubing complex for embryo delivery, is composed of a soft plastic leader tubing, a double opened connector for embryo loading and unloading, a semi-hard plastic tubing, and a hard tubing with a water-sealable plunger. Embryos (4-cell to blastocyst stages) were surgically collected and maintained in vitro up to 5 h before the non-surgical embryo transfer. Five of 16 recipients became pregnant (31%) and farrowed an average of 6.2 +/- 3.1 pigs per litter. This easily learned non-surgical embryo transfer technique will simplify embryo transfer in the swine industry and may lead to improvements in swine breeding and scientific research.

Developmental ability of porcine oocytes matured and fertilized in vitro

The developmental abilities of porcine oocytes matured and fertilized in vitro were examined in vivo and in vitro. Cumulus-oocyte complexes were cultured in mM199 supplemented with 10% porcine follicular fluid (PFF) and hormonal supplements (PMSG, hCG and estradiol-17beta) for 20 h and then without hormonal supplements for an additional 20 h. In Experiment 1, oocytes were then co-cultured for 6 h with spermatozoa which had been preincubated with 1% PFF (PFF-treated) or without (control). Oocytes were transferred to oviducts of gilts or cultured in modified Whitten's medium for 5 d. The percentages of oocytes with monospermic penetration (59%, 42 71 ) and with monospermic penetration and male and female pronuclei (32%, 23 71 ) were higher (P < 0.01) in the PFF-treated group than in controls (25%, 18 71 and 8%, 6 71 , respectively). After 5 d, the percentages of oocytes that developed to the morula or blastocyst stages in vitro and in vivo in the PFF-treated group (10%, 28 288 and 13%, 41 318 , respectively) were also higher (P < 0.05) than in controls (2%, 6 284 and 6%, 16 248 , respectively). Whereas some oocytes that were matured and fertilized in vitro developed to the blastocyst stage after 5 d in vivo culture (3%, 9 288 in PFF-treated group and 2%, 6 284 in control), no blastocysts were observed after 5 d when oocytes were cultured in vitro. When the progression of in vitro development of porcine oocytes that were matured and fertilized in vitro was examined in Experiment 2, morulae appeared after 72 h of culture, and 3% (3 100 ) of the oocytes developed to the blastocyst stage after 144 h (6 d) of culture. These results demonstrate that decreasing polyspermic penetration and increasing monospermic male pronuclear formation, as a result of PFF treatment of maturing spermatozoa, improved the developmental ability of porcine oocytes matured and fertilized in vitro. However, development in vitro was delayed by approximately 24 h compared with in vivo development, most of the embryos were blocked at the morula stage.