An amendment to this paper has been published and can be accessed via a link at the top of the paper.

The efficacy of the newly developed anticoagulant rodenticide, difethialone, was evaluated against various rodent species in laboratory and fields. Difethialone at 0.025% concentration in the form of loose bait (broken wheat and rice + veg. oil + garlic powder) gave absolute mortality in Rattus rattus, Mus musculus, Funambulus pennanti, and Meriones hurrianae during 'no-choice' tests in one day feeding. No significant difference was noted in poison bait intake and mean days to death between two and three days poison feeding. Mean days to death were ranged between 2.9 to 5.70 in all the species tested. In fields, baiting with the same loose bait (0.025%) was performed in the live burrows and 88.89% control recorded on the 4th day after treatment. In another trial, three large hay stacks situated near wheat, barley and mustard crops were also treated with difethialone (0.025%) and 90.47, 94.44 and 80.00% kills were recorded respectively. The results of the present investigation prove high potency and acceptability of difethialone against both domestic as well as field rodents.

Objective

To investigate the changes in running biomechanics after training in form-focused running using ChiRunning versus not-form focused training and self-directed training in untrained individuals.

Design

Pilot study-randomized controlled trial.

Setting

Research institution with tertiary care medical center.

Participants

Seventeen subjects (9 men, 8 women) with prehypertension.

Methods

Twenty-two participants were randomized to 3 study arms but 17 completed the study. The study arms were: (1) group-based Form-Focused running using ChiRunning (enrolled, n = 10; completed, n = 7); (2) group-based conventional running (enrolled, n = 6; completed, n = 4); and (3) self-directed training with educational materials (enrolled, n = 6; completed, n = 6). The training schedule was prescribed for 8 weeks with 4 weeks of follow-up. All subjects completed overground running motion analyses before and after training. ClinicalTrials.gov identifier for this study is NCT0158718.

Outcomes

Ankle, knee, hip joint peak moments, and powers; average vertical loading rate (AVLR); impact peak; cadence; stride length; strike index; and stride reach. Paired t tests were used to compare differences within groups over time.

Results

Form-focused group reduced their Stride Reach (P = .047) after the training but not the other groups. Form-focused group showed a close to significant reduction in knee adduction moment (P = .051) and a reduction in the peak ankle eversion moment (P = .027). Self-directed group showed an increase in the running speed (P = .056) and increases in ankle and knee joint powers and moments.

Conclusions

There are differences in the changes in running biomechanics between individuals trained in running form that emphasizes mid-foot strike, greater cadence, and shorter stride compared with those not trained in the these techniques. These differences may be associated with reduced lower extremity stress in individuals trained in this running form, but more studies are needed to confirm these findings in larger samples.

Objective

To evaluate the association of fatty infiltration of the quadriceps and vastus medialis (VM) with an increase in knee cartilage, meniscus, or bone marrow lesions, using magnetic resonance imaging (MRI) in knee osteoarthritis (OA) over 3 years.

Methods

Participants (n = 69) with and without radiographic knee OA underwent MRI at baseline and 3 years later. Chemical shift-based water/fat MRI was used to quantify the intramuscular fat fraction and the lean anatomical cross-sectional area (ACSA) for the VM and entire quadriceps muscles. MRI images of the knee were analyzed using the semiquantitative modified whole-organ MRI score (mWORMS) grading to assess change in lesions in the articular cartilage, meniscus, and bone marrow. Logistic regression was used to assess whether baseline quadriceps and VM fat fraction and lean ACSA were associated with an increase in mWORMS scores. Odds ratios (ORs) were adjusted for age, sex, and body mass index.

Results

Overall, of the 69 subjects, 43 (62%) had an increase in cartilage lesions (26 of 43), meniscus lesions (19 of 43), or bone marrow lesions (22 of 43) scores. The quadriceps (OR 2.13 [95% confidence interval (95% CI) 1.09-4.15]) and VM (OR 2.05 [95% CI 1.25-3.36]) fat fraction were both associated with an increase in cartilage, meniscus, or bone marrow lesion scores over 3 years. The association of quadriceps or VM lean ACSA with the outcomes was not significant.

Conclusion

These longitudinal findings using quantitative MRI methods for assessment of muscle adiposity highlight the role of quadriceps adiposity, specifically in the VM, in knee OA progression. However, studies in larger cohorts are needed to confirm these findings.

Objective

To establish a novel method of quantifying meniscal deformation using loaded MRI. More specifically, the goals were to evaluate the (1) accuracy, (2) inter-rater reliability, (3) intra-rater reliability, and (4) scan-rescan reliability. The secondary purpose of this experiment was to evaluate group differences in meniscal deformation in participants with and without radiographic knee OA.

Materials and methods

Weight-bearing 3-T MRIs of the knee in full extension and 30° of flexion were processed to create 3D models of meniscal deformation. Accuracy was assessed using a custom-designed phantom. Twenty-one participants either with or without signs of OA were evaluated, and another six participants (14 knees, one subject was scanned twice) underwent repeated imaging to assess scan-rescan reproducibility. Intraclass correlation coefficient (ICC), root-mean squared error (RMSE), and root-mean-square percent coefficient-of-variation (RMS%CV) analyses were performed. Exploratory comparisons were made between those with and without OA to evaluate potential group differences.

Results

All variables were found to be accurate with RMSE ranging from 0.08 to 0.35 mm and 5.99 to 14.63 mm(2). Reproducibility of peak anterior-posterior meniscal deformation was excellent (ICC > 0.821; p < 0.013) with RMS%CV for intra-rater ranging from 0.06 to 1.53 % and 0.17 to 1.97 %, inter-rater ranging from 0.10 to 7.20 % and 3.95 to 18.53 %, and scan-rescan reliability ranging from 1.531 to 7.890 % and 4.894 to 9.142 %, for distance and area metric, respectively. Participants with OA were found to have significantly greater anterior horn movement of both the medial (p = 0.039) and lateral meniscus (p = 0.015), and smaller flexed medial meniscus outer area (p = 0.048) when compared to controls.

Conclusions

MRI-based variables of meniscus deformation were found to be valid in participants with and without OA. Significant differences were found between those with and without radiographic OA; further study is warranted.

Objective

To investigate the differences in hip movement patterns during different daily and athletic activities in persons with cam-type femoroacetabular impingement (FAI) with and without cartilage lesions compared with control subjects in a preliminary study.

Design

Controlled laboratory study using a cross-sectional design.

Setting

Research institution with a tertiary care medical center.

Participants

Fifteen subjects [M:F, 13:2; age, 31.6 ± 9.7 years (range, 22-52 years); body mass index, 24.9 ± 4.6 (range, 18.8-38.4); FAI:control, 7:8].

Methods

All subjects had 3-Tesla magnetic resonance imaging of the hip and also underwent 3-dimensional motion capture during walking, deep-squat, and drop-landing tasks. Experienced radiologists graded cartilage lesions on clinical magnetic resonance images.

Outcomes

Peak kinematic and kinetic variables were compared between subjects who did and did not have FAI, and subjects who had FAI and cartilage lesions were compared with subjects who did not have cartilage lesions.

Results

Subjects who had FAI demonstrated no significant differences for walking or drop landing compared with control subjects. However, during the deep-squat task, subjects with FAI adducted more and had a greater internal rotation moment. Subjects who had cartilage lesions in the presence of a cam lesion demonstrated (1) no difference for walking; (2) greater adduction, greater internal rotation moment, and lower transverse plane range of motion during the deep-squat task; and (3) greater adduction and lower internal rotation during the drop-landing task compared with subjects who did not have cartilage lesions.

Conclusions

We observed differences in movement patterns between subjects who had FAI compared with control subjects. However, the differences were more pronounced between subjects with FAI who had cartilage lesions compared with subjects who did not have cartilage lesions. These findings highlight the importance of understanding the complex interplay between bony morphologic features, cartilage lesions, and movement patterns in persons with cam-type FAI.

Background

The objective of this pilot study was to evaluate cartilage T1ρ and T2 relaxation times and knee mechanics during walking and drop-landing for individuals with anterior cruciate ligament reconstruction (ACL-R).

Methods

Nine patients (6 men and 3 women, age 35.8 ± 5.4 years, BMI 23.5 ± 2.5 kg/m(2)) participated 1.5 ± 0.8 years after single-bundle two-tunnel ACL reconstruction. Peak knee adduction moment (KAM), flexion moment (KFM), extension moment (KEM), and peak varus were calculated from kinematic and kinetic data obtained during walking and drop-landing tasks. T1ρ and T2 times were calculated for medial femur (MF), and medial tibia (MT) cartilage and compared between subjects with low KAM and high KAM. Biomechanical variables were compared between limbs.

Results

The high KAM group had higher T1ρ for MT (p=0.01), central MT (p=0.05), posterior MF (p=0.04), posterior MT (p=0.01); and higher T2 for MT (p=0.02), MF (p=0.05), posterior MF (p=0.002) and posterior MT (p=0.01). During walking, ACL-R knees had greater flexion at initial contact (p=0.04), and lower KEM (p=0.02). During drop-landing, the ACL-R knees had lower KAM (p=0.03) and KFM (p=0.002).

Conclusion

Patients with ACL-R who have higher KAM during walking had elevated MR relaxation times in the medial knee compartments. These data suggest that those individuals who have undergone ACL-R and have higher frontal plane loading, may be at a greater risk of knee osteoarthritis.

Purpose

To introduce and validate an automated unsupervised multi-parametric method for segmentation of the subcutaneous fat and muscle regions to determine subcutaneous adipose tissue (SAT) and intermuscular adipose tissue (IMAT) areas based on data from a quantitative chemical shift-based water-fat separation approach.

Materials and methods

Unsupervised standard k-means clustering was used to define sets of similar features (k = 2) within the whole multi-modal image after the water-fat separation. The automated image processing chain was composed of three primary stages: tissue, muscle, and bone region segmentation. The algorithm was applied on calf and thigh datasets to compute SAT and IMAT areas and was compared with a manual segmentation.

Results

The IMAT area using the automatic segmentation had excellent agreement with the IMAT area using the manual segmentation for all the cases in the thigh (R(2): 0.96) and for cases with up to moderate IMAT area in the calf (R(2): 0.92). The group with the highest grade of muscle fat infiltration in the calf had the highest error in the inner SAT contour calculation.

Conclusion

The proposed multi-parametric segmentation approach combined with quantitative water-fat imaging provides an accurate and reliable method for an automated calculation of the SAT and IMAT areas reducing considerably the total postprocessing time.

Background

Understanding the acute response of healthy knee cartilage to running may provide valuable insight into functional properties. In recent years, quantitative magnetic resonance (MR) imaging techniques (T1(ρ) and T2 relaxation measurement) have shown tremendous potential and unique ability to noninvasively and quantitatively determine cartilage response to physiologic levels of loading occurring with physiologic levels of exercise.

Purpose

To measure the short-term changes in MR T1(ρ) and T2 relaxation times of knee articular cartilage and meniscus in healthy individuals immediately after 30 minutes of running.

Study design

Descriptive laboratory study.

Methods

Twenty young healthy volunteers, aged 22 to 35 years, underwent 3T MR imaging of the knee before and immediately after 30 minutes of running. Quantitative assessment of the cartilage and menisci was performed using MR images with a T1(ρ) and T2 mapping technique. After adjusting for age, sex, and body mass index, repeated-measures analysis of variance was used to determine the effects of running on MR relaxation times.

Results

The post-run T1(ρ) and T2 measurement showed significant reduction in all regions of cartilage except the lateral tibia when compared with the pre-run condition. The medial tibiofemoral (T1(ρ): 9.4%, P < .0001; T2: 5.4%, P = .0049) and patellofemoral (T1(ρ): 12.5%, P < .0001; T2: 5.7%, P = .0007) compartments experienced the greatest reduction after running. The superficial layer of the articular cartilage showed significantly higher change in relaxation times than the deep layer (T1(ρ): 9.6% vs 8.2%, P = .050; T2: 6.0% vs 3.5%, P = .069). The anterior and posterior horns of the medial meniscus (9.7%, P = .016 and 11.4%, P = .001) were the only meniscal subregions with significant changes in T1(ρ) after running.

Conclusion

Shorter T1(ρ) and T2 values after running suggest alteration in the water content and collagen fiber orientation of the articular cartilage. Greater changes in relaxation times of the medial compartment and patellofemoral joint cartilage indicate greater load sharing by these areas during running.