Evaluation of early post-natal pig mammary gland development and human breast cancer gene expression.

Breast cancer is the second leading cause of death in women after lung cancer, and only 5% of patients with metastatic breast cancer survive beyond ten years of diagnosis. Considering the heterogeneous subclasses of breast cancer, current cancer models have shortfalls due to copy number variants, and genetic differences of humans and immunocompromised animal models. Preclinical studies indicate stem cell activity in early post-natal mammary development may be reactivated in the human adult as a trigger to initiate cell proliferation leading to breast cancer. The goal of the work reported herein was to compare genetic expression of early development, post-natal pig mammary glands to the literature reported genes implicated in different subclasses of human breast cancer. Differentially expressed genes associated with breast cancer and present in early developing pig samples include NUCB2, ANGPTL4 and ACE. Histological staining confirmed E-cadherin, Vimentin, N-cadherin, and Claudin-1, which are all implicated in malignant cancer. Due to the homology of gene expression patterns in the developing pig mammary gland and reported genes in human breast cancer profiles, this research is worthy of further study to address a potential model using mammary development cues to unravel breast cancer biology.

Efficacy of phage cocktail AB-SA01 therapy in diabetic mouse wound infections caused by multidrug-resistant Staphylococcus aureus.

BACKGROUND: Diabetic foot ulcer (DFU) is a serious complication of diabetes mellitus. Antibiotic-resistant Staphylococcus aureus is frequently isolated from DFU infections. Bacteriophages (phages) represent an alternative or adjunct treatment to antibiotic therapy. Here we describe the efficacy of AB-SA01, a cocktail of three S. aureus Myoviridae phages, made to current good manufacturing practice (cGMP) standards, and which has undergone two phase I clinical trials, in treatment of multidrug-resistant (MDR) S. aureus infections. RESULTS: Wounds of saline-treated mice showed no healing, but expanded and became inflamed, ulcerated, and suppurating. In contrast, AB-SA01 treatment decreased the bacterial load with efficacy similar or superior to vancomycin treatment. At the end of the treatment period, there was a significant decrease (p < 0.001) in bacterial load and wound size in infected phage- and vancomycin-treated groups compared with infected saline-treated mice. In phage-treated mice, wound healing was seen similar to vancomycin treatment. No mortality was recorded associated with infections, and post-mortem examinations did not show any evident pathological lesions other than the skin wounds. No adverse effects related to the application of phages were observed. CONCLUSION: Topical application of phage cocktail AB-SA01 is effective, as shown by bacterial load reduction and wound closure, in the treatment of diabetic wound infections caused by MDR S. aureus. Our results suggest that topical phage cocktail treatment may be effective in treating antibiotic-resistant S. aureus DFU infections.

Towards Human Translation of Lentiviral Airway Gene Delivery for Cystic Fibrosis: A One-Month CFTR and Reporter Gene Study in Marmosets.

Gene therapy continues to be a promising contender for the treatment of cystic fibrosis (CF) airway disease. We have previously demonstrated that airway conditioning with lysophosphatidylcholine (LPC) followed by delivery of a HIV-1-based lentiviral (LV) vector functionally corrects the CF transmembrane conductance regulator (CFTR) defect in the nasal airways of CF mice. In our earlier pilot study we showed that our technique can transduce marmoset lungs acutely; this study extends that work to examine gene expression in this nonhuman primate (NHP) 1 month after gene vector treatment. A mixture of three separate HIV-1 vesicular stomatitis virus G (VSV-G)-pseudotyped LV vectors containing the luciferase (Luc), LacZ, and hCFTR transgenes was delivered into the trachea through a miniature bronchoscope. We examined whether a single-dose delivery of LV vector after LPC conditioning could increase levels of transgene expression in the trachea and lungs compared with control (phosphate-buffered saline [PBS]) conditioning. At 1 month, bioluminescence was detected in vivo in the trachea of three of the six animals within the PBS control group, compared with five of the six LPC-treated animals. When examined ex vivo there was weak evidence that LPC improves tracheal Luc expression levels. In the lungs, bioluminescence was detected in vivo in four of the six PBS-treated animals, compared with five of the six LPC-treated animals; however, bioluminescence was present in all lungs when imaged ex vivo. LacZ expression was predominantly observed in the alveolar regions of the lung. hCFTR was detected by qPCR in the lungs of five animals. Basal cells were successfully isolated and expanded from marmoset tracheas, but no LacZ-positive colonies were detected. There was no evidence of an inflammatory response toward the LV vector at 1 month postdelivery, with cytokines remaining at baseline levels. In conclusion, we found weak evidence that LPC conditioning improved gene transduction in the trachea, but not in the marmoset lungs. We also highlight some of the challenges associated with translational lung gene therapy studies in NHPs.

Fetal cardiovascular response to acute hypoxia during maternal anesthesia.

Preclinical imaging studies of fetal hemodynamics require anesthesia to immobilize the animal. This may induce cardiovascular depression and confound measures under investigation. We compared the impact of four anesthetic regimes upon maternal and fetal blood gas and hemodynamics during baseline periods of normoxia, and in response to an acute hypoxic challenge in pregnant sheep. Merino ewes were surgically prepared with maternal and fetal vascular catheters and a fetal femoral artery flow probe at 105-109 days gestation. At 110-120 days gestation, ewes were anesthetized with either isoflurane (1.6%), isoflurane (0.8%) plus ketamine (3.6 mg·kg-1 ·h-1 ), ketamine (12.6 mg·kg-1 ·h-1 ) plus midazolam (0.78 mg·kg-1 ·h-1 ), propofol (30 mg·kg-1 ·h-1 ), or remained conscious. Following 60 min of baseline recording, nitrogen was administered directly into the maternal trachea to displace oxygen and induce maternal and thus fetal hypoxemia. During normoxia, maternal PaO2 was ~30 mmHg lower in anesthetized ewes compared to conscious controls, regardless of the type of anesthesia (p < .001). There was no effect of anesthesia on fetal mean arterial blood pressure (MAP; p > .05), but heart rate was 32 ± 8 bpm lower in fetuses from ewes administered isoflurane (p = .044). During maternal hypoxia, fetal MAP increased, and peripheral blood flow decreased in all fetuses except those administered propofol (p < .05). Unexpectedly, hypoxemia also induced fetal tachycardia regardless of the anesthetic regime (p < .05). These results indicate that despite maternal anesthesia, the fetus can mount a cardiovascular response to acute hypoxia by increasing blood pressure and reducing peripheral blood flow, although the heart rate response may differ from when no anesthesia is present.

Castration promotes welfare in group-housed male Swiss outbred mice maintained in educational institutions.

Educational institutions maintain group-housed mice of both sexes for training veterinarians and technicians in husbandry, medication, and sampling procedures. Mice kept in all-male groups may experience poor welfare due to fighting. Castrated mice may be used to replace gonadally intact males for such training programs. In this prospective cohort study, 80 castrated and 80 control (intact) male mice were studied over 3 mo to monitor aggression frequency and injury levels. Behavioral observations were performed twice weekly by using an all-occurrences sampling method to quantify behavioral events and the number and severity of bite wounds. Under these housing conditions, group-housed male mice castrated postpubertally exhibited significantly less aggression than did intact male mice. Castration therefore improves welfare in group-housed male mice and thus provides a husbandry alternative to individually housing animals in nonstudy situations.