ABSTRACT
Although it is clear that opening-wedge high tibial osteotomy (HTO) changes alignment in the coronal plane, which is its objective, it is not clear how this procedure affects knee kinematics throughout the range of joint movement and in other planes. Our research question was: how does opening-wedge HTO change three-dimensional tibiofemoral and patellofemoral kinematics in loaded flexion in patients with varus deformity?Three-dimensional kinematics were assessed over 0° to 60° of loaded flexion using an MRI method before and after opening-wedge HTO in a cohort of 13 men (14 knees). Results obtained from an iterative statistical model found that at six and 12 months after operation, opening-wedge HTO caused increased anterior translation of the tibia (mean 2.6 mm, p < 0.001), decreased proximal translation of the patella (mean -2.2 mm, p < 0.001), decreased patellar spin (mean -1.4°, p < 0.05), increased patellar tilt (mean 2.2°, p < 0.05) and changed three other parameters. The mean Western Ontario and McMaster Universities Arthritis Index improved significantly (p < 0.001) from 49.6 (standard deviation (sd) 16.4) pre-operatively to a mean of 28.2 (sd 16.6) at six months and a mean of 22.5 (sd 14.4) at 12 months. The three-dimensional kinematic changes found may be important in explaining inconsistency in clinical outcomes, and suggest that measures in addition to coronal plane alignment should be considered.
Subject(s)
Bone Anteversion/surgery , Imaging, Three-Dimensional , Knee Joint/physiopathology , Magnetic Resonance Imaging/methods , Osteoarthritis, Knee/surgery , Osteotomy/methods , Adult , Biomechanical Phenomena , Bone Anteversion/complications , Female , Follow-Up Studies , Humans , Knee Joint/surgery , Male , Middle Aged , Models, Statistical , Osteoarthritis, Knee/complications , Osteoarthritis, Knee/physiopathology , Range of Motion, Articular , Treatment Outcome , Weight-BearingABSTRACT
Russet Burbank potato plants have been genetically improved to resist insect attack and damage by Colorado potato beetles (Leptinotarsa decemlineata (Say)) by the insertion of a cryIIIA gene encoding the insect control protein of Bacillus thuringiensis var. tenebrionis. A modified gene that dramatically improved plant expression of this protein was utilized. Its expression in Russet Burbank potato plants resulted in protection from damage by all insect stages in the laboratory and in dramatic levels of protection at multiple field locations. Analysis of these genetically modified potatoes indicated that they conform to the standards for Russet Burbank potatoes in terms of agronomic and quality characteristics including taste.
Subject(s)
Bacterial Proteins/genetics , Bacterial Toxins , Coleoptera , Endotoxins , Insect Control/methods , Plants, Genetically Modified , Solanum tuberosum/genetics , Amino Acid Sequence , Animals , Bacillus thuringiensis Toxins , Bacterial Proteins/pharmacology , Base Sequence , Feeding Behavior , Genetic Engineering , Genetic Vectors , Hemolysin Proteins , Insecticides/pharmacology , Molecular Sequence Data , Transformation, GeneticABSTRACT
A laboratory-selected colony of Heliothis virescens displaying a 20- to 70-fold level of resistance to Bacillus thuringiensis proteins was evaluated to identify mechanism(s) of resistance. Brush-border membrane vesicles were isolated from larval midgut epithelium from the susceptible and resistant strains of H. virescens. Two B. thuringiensis proteins, CryIA(b) and CryIA(c), were iodinated and shown to specifically bind to brush-border membrane vesicles of both insect strains. Multiple changes in the receptor-binding parameters were seen in the resistant strain as compared with the susceptible strain. A 2- to 4-fold reduction in binding affinity was accompanied by a 4- to 6-fold increase in binding-site concentration for both proteins. Although these two B. thuringiensis proteins competed for the same high-affinity binding site, competition experiments revealed different receptor specificity toward these proteins in the resistant H. virescens line. The H. virescens strains were not sensitive to a coleopteran-active protein, CryIIIA, nor did these proteins compete with the CryIA proteins for binding. Complexity of the mechanism of resistance is consistent with the complex mode of action of B. thuringiensis proteins.
Subject(s)
Bacillus thuringiensis/metabolism , Bacterial Proteins/metabolism , Bacterial Toxins , Endotoxins , Lepidoptera/metabolism , Microvilli/metabolism , Pest Control, Biological , Animals , Bacillus thuringiensis/genetics , Bacillus thuringiensis Toxins , Bacterial Proteins/genetics , Bacterial Proteins/pharmacology , Binding, Competitive , Digestive System/metabolism , Genes, Bacterial , Hemolysin Proteins , Kinetics , Larva , Lepidoptera/drug effects , Protein BindingABSTRACT
The host range and relative efficacy of three purified Bacillus thuringiensis insect control proteins were determined against 17 different agronomically important insects representing five orders and one species of mite. The three B. thuringiensis proteins were single gene products from B. thuringiensis ssp. kurstaki HD-1 (CryIA(b)) and HD-73 (CryIA(c)), both lepidopteran-specific proteins, and B. thuringiensis ssp. tenebrionis (CryIIIA), a coleopteran-specific protein. Seven insects showed sensitivity to both B. thuringiensis ssp. kurstaki proteins, whereas only 1 of the 18 insects was sensitive to B. thuringiensis ssp. tenebrionis protein. The level of B. thuringiensis ssp. kurstaki protein required for 50% mortality (LC50) varied by 2000-fold for these 7 insects. A larval growth inhibition assay was developed to determine the amount of B. thuringiensis ssp. kurstaki protein required to inhibit larval growth by 50% (EC50). This extremely sensitive assay enabled detection of B. thuringiensis ssp. kurstaki HD-73 levels as low as 1 ng/ml.
