The diagnostic value of 99mTc-IgG scintigraphy in the diabetic foot and comparison with 99mTc-MDP scintigraphy

Diabetic foot infection is the most common etiology of nontraumatic amputation of the lower extremities, and early diagnosis is of great importance in its management. The aim of this prospective study was to evaluate the strength of 99mTc-IgG scintigraphy in diagnosis of osteomyelitis of the diabetic foot and to compare 99mTc-IgG scintigraphy with 99mTc-methylene diphosphonate (MDP) scintigraphy. Methods: A prospective university hospital-based study was performed over 24 mo. Eighteen patients with type II diabetes and foot ulcers (15 men and 3 women; age range, 45-80 y) were referred for imaging because of clinically suspected osteomyelitis. Early (5-h) and late (24-h) 99mTc-IgG scanning and 3-phase skeletal scintigraphy were completed for all patients at a 3- to 4-d interval. Regions of interest over the involved bony sites and the contralateral normal sites were drawn, and the abnormal-to-normal ratios were acquired for both 99mTc-IgG and 99mTc-MDP studies. Results: From a total of 23 lesions, we observed 10 sites of osteomyelitis, 10 sites of cellulitis, and 3 sites of aseptic inflammation confirmed by MRI, clinical presentation, histopathologic examination, and follow-up evaluation as a gold standard. Both 99mTc-IgG and 99mTc-MDP scanning showed excellent sensitivity for diagnosis of osteomyelitis, but the specificity was significantly lower (69.2% and 53.8%, respectively). Sensitivity, specificity, and accuracy in the diagnosis of osteomyelitis were, respectively, 100%, 53.8%, 73.9% for 99mTc-MDP scanning; 100%, 69.2%, 82.6% for 5-h 99mTc-IgG scanning; and 60%, 76.9%, 69.5% for 24-h 99mTc-IgG scanning. There was no significant difference between the semiquantitative indices of 5-h and 24-h 99mTc-IgG scanning for inflammation, cellulitis, and osteomyelitis. Conclusion: Although both 99mTc-IgG and 99mTc-MDP scintigraphy have high sensitivity for the diagnosis of osteomyelitis, the specificity of these studies is poor. For 99mTc-IgG scintigraphy, 5-h images appear to be adequate, and there is little benefit to performing additional imaging at 24 h. © 2011 by the Society of Nuclear Medicine, Inc

The Effectiveness of Synthesized Zinc-Amino Chelates in Supplying Zinc for Wheat

This pot experiment was carried out to investigate the efficacy of certain Zn-amino chelates, i.e. Zn-glycine [Zn(Gly)2], Zn-arginine [Zn(Arg)2] and Zn-histidine [Zn(His)2] in supplying zinc for wheat was compared with a commercial Zn-sulfate fertilizer. Three wheat cultivars, differing in Zn-efficiency, including Back Cross Rowshan, Kavir and Durum were planted at Research Greenhouse of Isfahan University of Technology, Isfahan, Iran, in 2010. Fertilizer treatments were applied at planting and tillering stages, with 20 mg Zn per kg soil. Results showed that soil application of Zn fertilizers increased shoot Zn content of all three wheat cultivars in comparison with control (no addition of Zn) treatment. Shoot Zn content of Durum cultivar treated with Zn(Gly)2 was 33.3% higher than Zn-sulfate. The effect of Zn-amino chelates on activity of catalase (CAT) and ascorbate proxidase (APX) was dependent on the amino chelate type and wheat cultivar. Zinc-amino chelates resulted in increase of CAT activity in the leaves of Kavir and Back Cross Rowshan cultivars, while they were ineffective in Durum cultivar. In all three wheat cultivars, leaf activity of APX was also significantly increased by Zn(His)2 and Zn(Arg)2 over the Zn-sulfate treatment. According to the results of the present study, Zn-amino chelates could play more effective role in improving plant Zn nutrition status and increasing yield and seed quality of wheat by increasing Zn uptake and activities of CAT and APX enzymes

Using TCP models to understand bandwidth assurance in a differentiated services network, Nortel

Abstract—In this paper, a comprehensive analytical model to predict the bandwidth achieved by aggregates of TCP flows in a Diffserv network is presented. The model predicts achieved bandwidth in three different cases: an over-provisioned network, an under-provisioned network, and a nearprovisioned network. In developing the model, we ensure that all parameters are measurable using standard tools and information available from routers and network management tools in today’s networks. Simulation was used to establish the validity of the model and understand its scope of applicability and limitations. Using the model, we explain why achieved excess bandwidth is based on factors such as RTT, packet size, and CIR. Finally, we present a novel extension of the model to predict the bandwidth of TCP flows in a Diffserv network with multiple congested nodes. Index terms—Assured Forwarding PHB, Diffserv, multipl