Transformation of carrots with mutant acetolactate synthase for Orobanche (broomrape) control

Parasitic Orobanche spp are major constraints to vegetable crop production in the Mediterranean basin (to eastern Europe) and in localized places in India, China and the USA. Transgenic target-site herbicide resistance (eg, to acetolactate synthase inhibitors) allows for movement of unmetabolized herbicide through the crop to the photosynthate sink in the parasite, as well as through the soil. We report the successful engineering of a mutant acetolactate synthase (ALS) gene into carrot, allowing control of broomrape already in heterozygotes of the first back-crossed generation, by imazapyr, an imidazolinone ALS inhibitor. It is expected that homozygotes will have higher levels of resistance.     

Bending Characteristics of Polymethylmethacrylate Columns,Connecting Bars of Carbon Fiber,Titanium, and Stainless Steel Used in External Skeletal Fixation and an Acrylic Interface

Objective: To (1) mechanically evaluate polymethylmethacrylate (PMMA) columns of various sizes and compare them to connecting bar materials (carbon fiber composite, titanium, stainless steel) and (2) compare the properties of an intact PMMA column to those of an acrylic interface. Study Design: Experimental mechanical study. Sample Population: Experiment 1: 6 groups of 6 specimens each; experiment 2: 2 groups of 12 specimens each. Methods: All specimens were tested in 3‐point bending. Stiffness, yield strength, and ultimate strength values were calculated for each specimen. Results: PMMA 1 columns (23.25 mm) compared favorably to titanium or stainless‐steel bars. PMMA 3 columns (30.15 mm) and carbon fiber bars had similar yield strength but PMMA 3 columns were less stiff than carbon fiber bars. PMMA 3 columns had lower bending modulus and a higher variability in their mechanical properties than PMMA 1 or PMMA 2 (25.64 mm) columns. Acrylic interface specimens were less strong but as stiff as intact specimens. Conclusion: An acrylic interface was easily created and had acceptable biomechanical characteristics. Clinical Relevance: PMMA 2 and PMMA 3 columns are not recommended for clinical use at this time. Further tests are needed to analyze an acrylic patch in a more clinically relevant loading model.     

Ulnar ostectomy decreases the stability of canine cadaver carpi as assessed with stress radiography

Distal ulnar ostectomy may be performed palliatively in patients with distal ulnar osteosarcoma. Concurrent arthrodesis of the carpus has been proposed to counteract joint instability following transection of carpal ligaments associated with removal of the distal ulna. The objective of this prospective one group pretest, posttest study was to assess stability of the carpus following distal ulnar ostectomy using pre‐ and postoperative stress radiographic views in a group of canine cadaver limbs. Seven thoracic limbs from six canine cadavers weighing more than 20 kg were obtained. Lateral and dorsopalmar, extended lateral, medial stress, and lateral stress radiographs were made before and after distal ulnar ostectomy. Presurgical canine cadaver carpal angle measurements were as follows (mean ± standard deviation): extension 205.9° ± 5.4; medial stress 25.1° ± 5.7; and lateral stress 13.3° ± 5.2°. Cadaver limb joint angles exceeded those previously reported in live dogs. A significant increase in carpal angle was noted following ulnar ostectomy. The mean increases in carpal angle were as follows: (mean ± standard deviation (95% confidence interval)): extension 6.2° ± 4.9 (2.6–9.8) (P = 0.007); medial stress 3.2° ± 3.0 (1.0–5.5) (P = 0.015); lateral stress 6.2° ± 5.2 (2.4–10.1) (P = 0.010). Findings from this cadaver study support the use of supplementary stabilization for clinical patients undergoing distal ulnar ostectomy. Future studies are needed in clinical patients to evaluate changes in limb positioning and gait associated with distal ulnar ostectomy.