328 VERSATILE TRANSCRIPTION ACTIVATOR-LIKE EFFECTOR NUCLEASE (TALEN)-MEDIATED ENGINEERING OF OSSABAW MINIATURE SWINE

Transcription activator-like effector nucleases (TALEN) are programmable nucleases that join the modular DNA-binding domain of transcription activator-like (TAL) effectors with FokI endonuclease. TALEN-induced double-strand breaks can be used for gene inactivation via repair by nonhomologous end joining (NHEJ) or to stimulate homologous recombination with a user-specified template to create custom-designed disease alleles. Transfection of multiple TALEN pairs targeting the same chromosome can also produce chromosomal rearrangements such as large inversions and deletions. As genetic modification of primary pig fibroblast followed by cloning is the primary method used to generate transgenic swine, we tested our capacity to mimic multiple common mutation types in primary fibroblasts using TALEN. Either plasmids or mRNA encoding TALEN was transfected into 500 000 to 750 000 fibroblasts by nucleofection followed by 3 days of culture at 30°C before analysis of activity. With this approach, we found that over 65% of custom-designed TALEN displayed activity in pig fibroblasts with typical percentage of indel positive chromosomes ranging from 20 to 45%. Individual clones were derived by either co-selection with an unlinked selection transposon or by dilution cloning. Colonies with mono- and biallelic modification to the target loci were readily identified (up to 84 and 24%, respectively) and could be accomplished without the aid of selection. Co-transfection of 2 TALEN pairs directed to the same chromosome resulted in deletion or inversion of the intervening sequence in 10 and 4% of isolated colonies, respectively. In addition, co-transfection of TALEN with a homologous repair template enabled precise insertion of a novel restriction site in nearly 40% of treated cells, 3% of which were homozygous (n = 184 colonies). To prove that modified cells were suitable for generation of animals, we pooled several colonies of Ossabaw fibroblasts harboring TALEN-induced frame-shift mutations in the swine low-density lipoprotein receptor (LDLR) and used them as nuclear donors for cloning. Pregnancy was established in 7/9 transfers (100–150 embryos per transfer), and 6 pregnancies were carried to term, resulting in the live birth of 18 piglets. Three monoallelic frame-shift genotypes were observed among 9 piglets; as expected, each genotype was represented in the parental cell pool. The remaining 9 animals displayed an identical biallelic mutant genotype and are being investigated as a knockout model of familial hypercholesterolemia (FH). Finally, fibroblasts homozygous for a specified inactivating mutation were created by allele introgression and were cloned, demonstrating that gene editing can be used to create precise swine knock-ins in a single generation.

337 NONMEIOTIC INTROGRESSION OF QUANTITATIVE TRAIT NUCLEOTIDES AND CORRECTION OF CONGENITAL MUTATIONS IN LIVESTOCK WITH TRANSCRIPTION ACTIVATOR-LIKE EFFECTOR NUCLEASES

Genetic enhancement of livestock productivity and welfare are major goals of breeding and genetics programs. However, the introgression of desirable alleles across breeds is slow and inaccurate. The development of gene editing technologies would provide the opportunity to accelerate the genetic improvement of a diversity of livestock breeds. Transcription activator-like effector nucleases (TALEN) are programmable nucleases that join the modular DNA binding domain of transcription activator-like (TAL) effectors with FokI endonuclease. We found that TALEN could be easily manufactured and that 64% displayed activity in swine and cattle primary fibroblasts, with cleavage of 1.5 to 45% of chromosomes in cell populations, as measured by Surveyor assay. Clonal isolation and sequencing revealed that up to 84% of cells contained at least one modified allele, with up to 24% of cells containing biallelic or homozygous chromosomal modification. Co-transfection of a customized TALEN pair with a template containing a specific allele was effective at the nonmeiotic introgression of quantitative trait into naïve cattle breeds. We will also describe the repair of 2 recently described embryonic lethal mutations that are segregating in important dairy cattle breeds (JH1 and HH1). Injection of TALEN mRNA into the cytoplasm of pig and cattle zygotes was capable of inducing gene knockout (KO) in 27 to 75% of embryos analysed (n = 4–59), nearly half of which (8/19) harbored biallelic modification. We will present data describing efforts towards gene conversion by direct injection of livestock embryos. Finally, we will present alternative strategies for the incorporation of gene editing in livestock production systems by cloning or embryo treatment.

Chronic osteomyelitis secondary to human bite: a case report

ABSTRACT

We report a case of a human bite that was initially inadequately treated and progressed to chronic osteomyelitis, finally resulting in digital amputation. Human bites are seemingly innocuous, but if neglected, may lead to subsequent infection and morbidity. Persistence of symptoms should alert the practitioner to the possibility of infection extending to the soft tissue or bone. Bacteriological studies commonly yield mixed aerobic and anaerobic flora. Early debridement and antibiotic treatment may prevent development of severe soft tissue or bone infection.

KEY WORDS

human bite, osteomyelitis, amputation.

Restricted spirometry in the Burden of Lung Disease Study

BACKGROUND

The presence of restrictive lung disease has classically required the measure of total lung capacity to document 'true' restriction, which has limited its detection in large population-based studies.

METHODS

We used spirometric data to classify people with restricted spirometry (forced expiratory volume in 1 second [FEV(1)]/forced vital capacity ≥ 0.70 and FEV(1) < 80% predicted) in the Burden of Lung Disease (BOLD) Study and determined the relation between this finding and demographic factors and the presence of chronic diseases, including diabetes mellitus, hypertension and cardiovascular disease.

RESULTS

Overall, we found that 11.7% of men (546/4664) and 16.4% of women (836/5098) had restricted spirometry. Prevalence varied widely by site, from a low of 4.2% among males in Sydney, Australia, to a high of 48.7% among females in Manila, The Philippines. Compared to people with normal lung function, those with restricted spirometry had a higher prevalence of diabetes (12.2% vs. 4.6%), heart disease (15.0% vs. 7.7%) and hypertension (38.8% vs. 22.8%).

CONCLUSIONS

Restricted spirometry is a common finding in population studies. Additional research is needed to better define and describe the mechanisms that lead to restricted spirometry and potential interventions.

Compressive elasticity of three-dimensional nanofiber matrix directs mesenchymal stem cell differentiation to vascular cells with endothelial or smooth muscle cell markers

The importance of mesenchymal stem cells (MSC) in vascular regeneration is becoming increasingly recognized. However, few in vitro studies have been performed to identify the effects of environmental elasticity on the differentiation of MSC into vascular cell types. Electrospinning and photopolymerization techniques were used to fabricate a three-dimensional (3-D) polyethylene glycol dimethacrylate nanofiber hydrogel matrix with tunable elasticity for use as a cellular substrate. Compression testing demonstrated that the elastic modulus of the hydrated 3-D matrices ranged from 2 to 15 kPa, similar to the in vivo elasticity of the intima basement membrane and media layer. MSC seeded on rigid matrices (8-15 kPa) showed an increase in cell area compared with those seeded on soft matrices (2-5 kPa). Furthermore, the matrix elasticity guided the cells to express different vascular-specific phenotypes with high differentiation efficiency. Around 95% of MSC seeded on the 3-D matrices with an elasticity of 3 kPa showed Flk-1 endothelial markers within 24h, while only 20% of MSC seeded on the matrices with elasticity >8 kPa demonstrated Flk-1 marker. In contrast, ∼80% of MSC seeded on 3-D matrices with elasticity >8 kPa demonstrated smooth muscle α-actin marker within 24h, while fewer than 10% of MSC seeded on 3-D matrices with elasticity <5 kPa showed α-actin markers. The ability to control MSC differentiation into either endothelial or smooth muscle-like cells based purely on the local elasticity of the substrate could be a powerful tool for vascular tissue regeneration.

The response scale for the intellectual disability module of the WHOQOL: 5-point or 3-point?

OBJECTIVE

To deal with the question of whether a 5-point response Likert scale should be changed to a 3-point scale when used in the field testing of people with intellectual disabilities (IDs), which was raised after the pilot study of World Health Organization Quality of Life (WHOQOL)-DIS, a module being developed with the World Health Organization measure of quality of life for disabilities.

METHODS

Three possible ways were used to generate hypothetical data by merging a 5-point scale into a 3-point scale. The analyses were based on both item response theory and classical measurement theory. The partial credit model for polytomous response was performed for item evaluation; the confirmatory factor analysis was used to check construct validity, the Cronbach's alpha for domain reliability, and correlation analyses for the relationship between the 5-point scale and the generated 3-point scale.

RESULTS

Most items with a 5-point response scale had disordered response options and/or unequal-length intervals between successive response options; these deficiencies were removed or improved without decline of validity and reliability in the hypothetical data of 3-point scales.

CONCLUSION

Instead of the 5-point scale, a 3-point scale could be used for IDs in the field test of developing the module WHOQOL-DIS.

MC0553: A phase II safety and efficacy study with the VEGF receptor tyrosine kinase inhibitor pazopanib in patients with metastatic urothelial cancer

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Background: Vascular endothelial growth factor (VEGF) and platelet derived growth factor (PDGF) are produced by bladder cancer cell lines in vitro and expressed in human tumor tissues. Preclinical studies have also shown that bladder cancer cell lines express VEGF receptor 1 and 2 on their surface membrane. Pazopanib is a vascular endothelial receptor tyrosine kinase inhibitor with anti-angiogenesis and antitumor activity in several preclinical models. A two-stage phase II study was conducted to assess the activity and toxicity profile of pazopanib administered to patients with metastatic, urothelial carcinoma.

Methods: Patients with one prior systemic therapy for recurrent, metastatic urothelial carcinoma were eligible. Patients received pazopanib at a dose of 800 mg orally daily for 4 week cycle.

Results: Nineteen patients were enrolled. Median age was 66 years, with > 89% of patients presenting poorly differentiated bladder cancer. Adverse event data is available on 18 patients. No grade 4 or 5 events have been experienced. Nine patients have experienced 11 grade 3 adverse events of which 7 were deemed at least possibly related to treatment. Most common toxicities were anemia, thrombocytopenia, leucopenia and fatigue. For stage 1, none of the first 16 evaluable patients were deemed success (CR or PR) by the RECIST criteria during the first four 4-week cycles of treatment. Median progression- free survival was 1.9 months. This met the futility stopping rule of interim analysis, and therefore, the trial was recommended to be permanently closed. Correlative studies including measurement of VEGF levels in archived tissues and blood are pending.

Conclusions: Pazopanib did not show activity in urothelial carcinoma patients. The role of anti-VEGF therapies in urothelial carcinoma may need further evaluation in rational combination strategies.

[Table: see text]

Phase II multicenter study of erlotinib with radiation therapy (RT) for elderly patients (pts) with esophageal carcinoma (EC): Final report

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Background: Elderly pts with comorbidities have limited Rx options for localized EC. High EGFR expression correlates with poor response to RT. We examined the safety and efficacy of erlotinib, an oral EGFR tyrosine kinase inhibitor with RT in these pts.

Methods: Pts older than 65 yrs ineligible for platinum based Rx with carcinoma of the thoracic esophagus or gastroesophageal junction received erlotinib 150mg PO QD for one year starting D1 of RT [50.4 Gy D1-28 (M-F) at 1.8 Gy per fraction]. Assessments- mucosal response by EGD 4-8 wks post RT; RECIST response by CT q3mo. Endpoints: Primary- overall survival (OS), secondary- quality of life (QOL) using the FACT-E QOL tool, progression free survival (PFS) and toxicity; correlative- pre-treatment tumor EGFR and pEGFR expression by immunohistochemistry (IHC).

Results: The study was closed after 17 of planned 35 pts were included due to poor accrual. Baseline characteristics: median age 78 yrs (66-91); gender M/F: 11/6; ECOG PS 0/1/2=2/12/3; stage I-1, II=5, III=7 and IVa= 4; histology: adenocarcinoma 16, squamous cell 1; dysphagia at baseline 13/17 (76%). Median OS was 7.3 months (95% CI: 4.5-22.3) with 12 pts dead (5 alive, 3 still on treatment). Reason for coming off study (n=14): disease progression (n=6), toxicity (n=5), withdrew consent, completed one year of treatment, death from unrelated cause (n=1 each). There were 2 mucosal CRs and one residual carcinoma in situ, 3 partial endoscopic responses of the 9 pts who had post RT endoscopy. Estimated PFS is 5.3 months (95% CI: 2.4-11). Sites of progression- distant 3, locoregional 6, unknown 5 and too early 3. Estimated one year survival is 26 %, 3 pts lived >12 months. Smoking status- current/past/never 3/12/2. Treatment related toxicities (any grade n=or>5) were, rash (16), fatigue (16), diarrhea (11), lymphopenia (10), anorexia (7) and dehydration (6) and 21 grade 3/4 toxicities occurred. IHC results- EGFR, neg: 1/16; pos: 15/16 and pEGFR, neg: 2/16; pos:14/16.

Conclusions: For elderly pts with localized EC and no chemotherapy options, erlotinib monotherapy with RT is a tolerable therapy with modest activity. Further studies are needed to define the role of EGFR inhibition with RT in EC.

No significant financial relationships to disclose.

Biohybrid nanofiber constructs with anisotropic biomechanical properties

Synthetic implant materials often lack of the anisotropic mechanical properties and cell-interactive surface which are shown by natural tissues. For example, engineered vascular grafts need to be developed to address the mechanical and biological problems associated with the graft materials. This study has demonstrated a double-electrospinning fabrication process to produce a poly(ε-caprolactone)-fibroin multilayer composite which shows well-integrated nanofibrous structure, endothelial-conducive surface and anisotropic mechanical property, suitable as engineered vascular constructs. Electrospinning parameters such as voltage, solution concentration, feed rate, and relative humidity were optimized to obtain defect-free, uniform nanofibers. To mimic the different mechanical properties of natural vessels in the circumferential and longitudinal directions, a rotating cylinder was used as collector, resulting in the production of constructs with anisotropic properties. The combination of the collector shape and the collector rotation allows us to produce a tubular structure with tunable anisotropic mechanical properties. Fourier transform infrared spectroscopy, differential scanning calorimetry, and uniaxial tensile tests were used to characterize the electrospun constructs. Cell cultures with primary endothelial cells demonstrated that cells showed spread morphology and strong adhesion on fibroin richer surfaces. The platform for producing robust multilayer scaffolds with intermixing nanofiber structure, tunable anisotropy ratio, and surface with specific compositions may hold great potential in tissue engineering applications.

GaN nanowire functionalized with atomic layer deposition techniques for enhanced immobilization of biomolecules

We report the use of atomic layer deposition (ALD) coating as a nanobiosensor functionalization strategy for enhanced surface immobilization that may enable higher detection sensitivity. Three kinds of ALD coating films, Al(2)O(3), TiO(2), and SiO(2), were grown on the gallium nitride nanowire (GaN NW) surfaces and characterized with high-resolution transmission electron microscopy (HRTEM) and vacuum Fourier transform infrared spectroscopy (FTIR). Results from HRTEM showed that the thicknesses of ALD-Al(2)O(3), ALD-TiO(2) and ALD-SiO(2) coatings were 4-5 nm, 5-6 nm, and 12-14 nm, respectively. Results from FTIR showed that the OH contents of these coatings were, respectively, ∼6.9, ∼7.4, and ∼9.3 times that of piranha-treated GaN NW. Furthermore, to compare protein attachments on the different surfaces, poly(ethylene glycol) (PEG)-biotin was grafted on the OH-functionalized GaN NW surfaces through active Si-Cl functional groups. Streptavidin protein molecules were then attached to the biotin ends via specific binding. The immobilized streptavidin molecules were examined with scanning electron microscopy, HRTEM, and fluorescent imaging. Results from HRTEM and energy-dispersive X-ray revealed that the nitrogen concentrations on the three ALD coatings were significantly higher than that on the piranha-treated surface. Results from fluorescent imaging further showed that the protein attachments on the Al(2)O(3), TiO(2), and SiO(2) ALD coatings were, respectively, 6.4, 7.8, and 9.8 times that of piranha-treated surface. This study demonstrates that ALD coating can be used as a functionalization strategy for nanobiosensors because it is capable of creating functional groups with much higher density compared to widely used acid modifications, and among the three ALD coatings, ALD-SiO(2) yielded the most promising results in OH content and protein attachment.