Kinematic function of knee implant designs across a range of daily activities.

The aim of this randomized controlled trial was to measure and compare six-degree-of-freedom (6-DOF) knee joint motion of three total knee arthroplasty (TKA) implant designs across a range of daily activities. Seventy-five TKA patients were recruited to this study and randomly assigned a posterior-stabilized (PS), cruciate-retaining (CR), or medial-stabilized (MS) implant. Six months after surgery, patients performed five activities of daily living: level walking, step-up, step-down, sit-to-stand, and stand-to-sit. Mobile biplane X-ray imaging was used to measure 6-DOF knee kinematics and the center of rotation of the knee in the transverse plane for each activity. Mean 6-DOF knee kinematics were consistently similar for PS and CR, whereas MS was more externally rotated and abducted, and lateral shift was lower across all activities. Peak-to-peak anterior drawer for MS was also significantly lower during walking, step-up, and step-down (p < 0.017). The center of rotation of the knee in the transverse plane was located on the medial side for MS, whereas PS and CR rotated about the lateral compartment or close to the tibial origin. The kinematic function of MS was more similar to that of the healthy knee than PS and CR based on reduced paradoxical anterior translation at low flexion angles and a transverse center of rotation located in the medial compartment. Overall, 6-DOF knee joint motion for PS and CR were similar across all daily activities, whereas that measured for MS was appreciably different. The kinematic patterns observed for MS reflects a highly conforming medial articulation in the MS design.

A microCT imaging protocol for reproducible and efficient quantitative morphometric analysis (QMA) of joint structures of the in situ mouse tibio-femoral joint.

Micro-computed tomography (microCT) offers a three-dimensional (3D), high-resolution technique for the visualisation and analysis of bone microstructure. Using contrast-enhanced microCT, this capability has been expanded in recent studies to include cartilage morphometry and whole joint measures, known together as quantitative morphometric analysis (QMA). However, one of the main challenges in quantitative analysis of joint images is sensitivity to joint pose and alignment, which may influence measures related to both joint space and joint biomechanics. Thus, this study proposes a novel microCT imaging protocol for reproducible and efficient QMA of in situ mouse tibio-femoral joint. This work consists of two parts: an in situ diffusion kinetics study for a known cationic iodinated contrast agent (CA4+) for QMA of the cartilage, and a joint positioning and image processing workflow for whole joint QMA. In the diffusion kinetics study, 8 mice were injected at both of their tibio-femoral joints with distinct CA4+ concentrations and diffusion times. The mice were scanned at different time points after injection, and evaluated using attenuation and cartilage QMA measures. Results show that cartilage segmentation and QMA could be performed for CA4+ solution at a concentration of 48 mg/ml, and that reliable measurement and quantification of cartilage were achieved after 5 min of diffusion following contrast agent injection. We established the joint positioning and image processing workflow by developing a novel positioning device to control joint pose during scanning, and a spherical harmonics-based image processing workflow to ensure consistent alignment during image processing. Both legs of seven mice were scanned 10 times, 5 prior to receiving CA4+ and 5 after, and evaluated using whole joint QMA parameters. Joint QMA evaluation of the workflow showed excellent reproducibility; intraclass correlation coefficients ranged from 0.794 to 0.930, confirming that the imaging protocol enables reproducible and efficient QMA of joint structures in preclinical models, and that contrast agent injection did not cause significant alteration to the measured parameters.

Contrast-enhanced micro-computed tomography of articular cartilage morphology with ioversol and iomeprol.

Non-ionic, low-osmolar contrast agents (CAs) used for computed tomography, such as Optiray (ioversol) and Iomeron (iomeprol), are associated with the reduced risk of adverse reactions and toxicity in comparison with ionic CAs, such as Hexabrix. Hexabrix has previously been used for imaging articular cartilage but has been commercially discontinued. This study aimed to evaluate the efficacy of Optiray and Iomeron as alternatives for visualisation of articular cartilage in small animal joints using contrast-enhanced micro-computed tomography (CECT). For this purpose, mouse femora were immersed in different concentrations (20%-50%) of Optiray 350 or Iomeron 350 for periods of time starting at five minutes. The femoral condyles were scanned ex vivo using CECT, and regions of articular cartilage manually contoured to calculate mean attenuation at each time point and concentration. For both CAs, a 30% CA concentration produced a mean cartilage attenuation optimally distinct from both bone and background signal, whilst 5-min immersion times were sufficient for equilibration of CA absorption. Additionally, plugs of bovine articular cartilage were digested by chondroitinase ABC to produce a spectrum of glycosaminoglycan (GAG) content. These samples were immersed in CA and assessed for any correlation between mean attenuation and GAG content. No significant correlation was found between attenuation and cartilage GAG content for either CAs. In conclusion, Optiray and Iomeron enable high-resolution morphological assessment of articular cartilage in small animals using CECT; however, they are not indicative of GAG content.

Plant growth promoting bacteria associated with corm of Crocus sativus during three growth stages.

Corm, being a unit of reproduction and storage, plays an indispensable role in the life cycle of Crocus sativus (saffron). This study deals with the screening of bacteria isolated from cormosphere (area surrounding the corm sheath) of C. sativus during three growth stages for biofertilizer and biocontrol property. Out of 1000 protease producing bacteria isolated from the cormosphere (soil adhering corm sheath in analogy to rhizosphere), three plant growth promoting (PGP) Bacilli namely Bacillus thuringiensis DC1, B. megaterium VC3 and B. amyloliquefaciens DC8 were selected based on multiple and maximum PGP traits along with corm rot pathogen antagonism. To evaluate in vivo efficacy of the consortia, pot trials were conducted and a significant increase in number and length of both, shoot and root were observed. Further, the disease incidence in test corms was reduced by threefold as compared to control and the number of daughter corms produced in pot trials was also increased. Since corm is a unit of reproduction/propagation, increase in its number is of major significance. This is the first report on isolation and characterization of Plant growth promoting bacteria from any cormosphere.

Incidence of Haemoproteus columbae in pigeons of Jammu district.

Haemoproteus columbae is the major protozoan infection reported in pigeon and appeared in the erythrocyte of the peripheral circulation. Incidence and parasitaemia of H. columbae in pigeon was studied in different localities of Jammu, India for a period from April to September 2010 using thin blood smear examination. Of the 150 pigeons (wild: 70, domestic: 80), 92 (61.33 %) were found to be infected with H. columbae. Domestic pigeon showed higher incidence rate (74.28 %) than the wild (50 %). Mature and immature gametocyte encircled the erythrocyte nucleus to form a halter shaped appearance were characteristic feature of the parasite. Pseudolynchia canariensis, the vector for H. columbae was also recovered from beneath the feathers of pigeons. No other haemoprotozoan parasite was observed in the blood smear of examined pigeon. Counting of infected erythrocyte revealed higher affection of 1-2 erythrocytes indicative of milder infection in the birds. A long term study within bird population is essential in order to disclose seasonal variation in parasite, vector density and age of infection such as nesting area.

Multifocal skeletal tuberculosis involving the lumbar spine and iliac bone, mimicking a malignant bone tumour: a case report.

ABSTRACT: Multifocal osteoarticular tuberculosis is uncommon and accounts for approximately10% of all cases of osteoarticular tuberculosis. Concomitant vertebral and iliac bone tuberculosis has not been reported in the literature to date. We report one such case for its unusual clinical and radiological presentation, which had presentation more similar to a malignant bone tumour than an infection. KEY WORDS: Skeletal tuberculosis, multifocal osteoarticular tuberculosis.

Multifocal Skeletal Tuberculosis Involving the Lumbar Spine and Iliac Bone, Mimicking a Malignant Bone Tumour: A Case Report

Multifocal osteoarticular tuberculosis is uncommon and accounts for approximately10% of all cases of osteoarticular tuberculosis. Concomitant vertebral and iliac bone tuberculosis has not been reported in the literature to date. We report one such case for its unusual clinical and radiological presentation, which had presentation more similar to a malignant bone tumour than an infection.