Viral transduction of male germline stem cells results in transgene transmission after germ cell transplantation in pigs.

Genetic modification of germline stem cells (GSCs) is an alternative approach to generate large transgenic animals where transgenic GSCs are transplanted into a recipient testis to generate donor-derived transgenic sperm. The objective of the present study was to explore the application of viral vectors in delivering an enhanced green fluorescent protein (EGFP) transgene into GSCs for production of transgenic gametes through germ cell transplantation. Both adeno-associated virus (AAV)- and lentivirus (LV)-based vectors were effective in transducing pig GSCs, resulting in the production of transgenic sperm in recipient boars. Twenty-one boars treated with busulfan to deplete endogenous GSCs and nine nontreated boars received germ cell transplantation at 12 wk of age. Semen was collected from recipient boars from 5 to 7 mo posttransplantation when boars became sexually mature, and semen collection continued for as long as 5 yr for some boars. The percentage of ejaculates that were positive for the EGFP transgene ranged from 0% to 54.8% for recipients of AAV vector-transduced germ cells (n = 17) and from 0% to 25% for recipients of LV vector-transduced germ cells (n = 5). When semen from two AAV recipients was used for in vitro fertilization (IVF), 9.09% and 64.3% of embryos were transgenic. Semen collected from two LV-vector recipients produced 7.7% and 26.3% transgenic IVF embryos. Here, we not only demonstrated AAV-mediated GSC transduction in another large animal model (pigs) but also showed, to our knowledge for the first time, that LV-mediated GSC transduction resulted in transgene transmission in pigs.

Impact of Rabeprazole on APO-Dabigatran Exposure in Healthy Volunteers.

Background: Dabigatran is effective and safe for stroke prevention in patients with atrial fibrillation and for venous thromboembolism prevention and treatment. In Canada, APO-dabigatran, a generic formulation, has been approved based on a bioequivalence study, but its bioavailability in settings of reduced gastric acidity has not been examined. Methods: Treatment With APO-Dabigatran Absorption (TADA) was an open-label crossover study in 46 healthy male volunteers, comparing the absorption of APO-dabigatran (150 mg) with vs without rabeprazole. The primary outcome was the 24-hour total dabigatran exposure as measured by area under the curve (AUC) and peak concentration (Cmax). Results: Compared with no rabeprazole pretreatment, the total dabigatran AUC (geometric mean [gmean] AUC0-tz: 567.2 vs 804 ngh/mL, and gmean AUC0-∞: 609.7 vs 804) and Cmax (gmean: 64.1 vs 104.4 ng/mL) were significantly reduced with rabeprazole. The percent gmean ratios for AUC0-tz, AUC0-∞, and Cmax (with rabeprazole vs without) were 70.5% (95% confidence interval [CI]: 51.9% to 95.7%), 71.8% (95% CI: 53.1% to 96.9%), and 61.4% (95% CI: 44.1% to 85.5%), respectively. With rabeprazole, the proportions of participants with > 50% reduction in AUC0-tz, AUC0-∞, and Cmax were 32.6%, 30.4%, and 39.1%, respectively. Conclusions: When APO-dabigatran is administered with rabeprazole, the exposure to dabigatran is reduced by about 30%, which is similar to the level observed with Pradaxa when it was co-administered with a proton pump inhibitor. However, the finding that one-third of participants had a > 50% reduction in exposure is concerning, and it highlights the need for caution in patients who have, or are at risk of, reduced gastric acidity.

Contexte: Le dabigatran est une option thérapeutique sûre et efficace pour prévenir les accidents vasculaires cérébraux chez les patients atteints de fibrillation auriculaire et pour prévenir et traiter les thromboembolies veineuses. Au Canada, APO-dabigatran (une version générique) a été homologué sur la base d'une étude de bioéquivalence, mais sa biodisponibilité en contexte d'acidité gastrique réduite n'a pas été évaluée. Méthodologie: L'étude TADA ( T reatment with A PO- D abigatran A bsorption) est une étude croisée menée en mode ouvert auprès de 46 hommes volontaires en bonne santé, afin de comparer l'absorption d'APO-dabigatran (à 150 mg) avec et sans rabéprazole. Le critère d'évaluation principal était l'exposition totale sur 24 heures au dabigatran, telle que mesurée par la surface sous la courbe (SSC) et la concentration maximale (Cmax). Résultats: Par rapport à une administration sans prétraitement par rabéprazole, une réduction significative de la SSC totale du dabigatran (moyenne géométrique [MG] SSC0-tz : 567,2 par rapport à 804 ngh/ml; MG SSC0-∞ : 609,7 par rapport à 804 ngh/ml) et de la Cmax (MG : 64,1 par rapport à 104,4 ng/ml) a été observée avec la prise de rabéprazole. Les ratios des MG en pourcentage de la SSC0-tz, de la SSC0-∞, et de la Cmax (avec et sans rabéprazole) étaient de 70,5 % (intervalle de confiance [IC] à 95 % : 51,9 % à 95,7 %), 71,8 % (IC à 95 % : 53,1 % à 96,9 %) et 61,4 % (IC à 95 % : 44,1 % à 85,5 %), respectivement. Les proportions de participants chez qui une réduction de > 50 % de la SSC0-tz, de la SSC0-∞ ou de la Cmax a été notée avec l'administration du rabéprazole s'élevaient à 32,6 %, 30,4 % et 39,1 %, respectivement. Conclusions: Lors de l'administration d'APO-dabigatran en concomitance avec le rabéprazole, l'exposition au dabigatran était réduite d'environ 30 %, une valeur comparable à la réduction observée lors de l'administration de Pradaxa en concomitance avec un inhibiteur de la pompe à protons. La réduction de > 50 % de l'exposition médicamenteuse chez le tiers des participants n'en est pas moins préoccupante et démontre la nécessité de faire preuve de prudence lorsque l'acidité gastrique est réduite ou risque d'être réduite chez un patient.

Rivaroxaban for the prevention of major adverse cardiovascular events in patients with coronary or peripheral artery disease.

In the COMPASS trial, the combination of rivaroxaban 2.5 mg twice daily and low-dose aspirin 75-100 mg daily produced a net clinical benefit of 20% in patients with chronic atherosclerotic vascular disease because it reduced major adverse events by 24% and overall mortality by 18% despite an initial increase in major bleeding. In this paper, we examine the rationale for targeting coagulation factor Xa in patients with atherosclerosis, summarize the pharmacology of the 2.5-mg dose, review the trials that led to the approval of the combination of rivaroxaban and aspirin for the long-term management of patients with chronic coronary artery disease or peripheral artery disease and discuss who would benefit the most. We also address the unresolved issues and challenges in the implementation of this therapy.

Effect of gender on computerized electrocardiogram measurements in college athletes.

BACKGROUND: Broad criteria for classifying an electrocardiogram (ECG) as abnormal and requiring additional testing prior to participating in competitive athletics have been recommended for the preparticipation examination (PPE) of athletes. Because these criteria have not considered gender differences, we examined the effect of gender on the computerized ECG measurements obtained on Stanford student athletes. Currently available computer programs require a basis for "normal" in athletes of both genders to provide reliable interpretation. METHODS: During the 2007 PPE, computerized ECGs were recorded and analyzed on 658 athletes (54% male; mean age, 19 +/- 1 years) representing 22 sports. Electrocardiogram measurements included intervals and durations in all 12 leads to calculate 12-lead voltage sums, QRS amplitude and QRS area, spatial vector length (SVL), and the sum of the R wave in V5 and S wave in V2 (RSsum). RESULTS: By computer analysis, male athletes had significantly greater QRS duration, PR interval, Q-wave duration, J-point amplitude, and T-wave amplitude, and shorter QTc interval compared with female athletes (all P < 0.05). All ECG indicators of left ventricular electrical activity were significantly greater in males. Although gender was consistently associated with indices of atrial and ventricular electrical activity in multivariable analysis, ECG measurements correlated poorly with body dimensions. CONCLUSION: Significant gender differences exist in ECG measurements of college athletes that are not explained by differences in body size. Our tables of "normal" computerized gender-specific measurements can facilitate the development of automated ECG interpretation for screening young athletes.