New composite tissue allograft model of vascularized bone marrow transplant: the iliac osteomyocutaneous flap

Vascularized bone marrow transplant (VBMT) induces donor-specific chimerism in experimental models across the major histocompatibility barrier. An experimental model for immunotolerance studies should sustain a high antigenicity with low morbidity. Accordingly, we introduced an iliac bone osteomusculocutaneous (IBOMC) transplant model in rat. It consists of a large skin component and an abundant bone marrow cells (BMC) population. We tested this model with isograft transplantations between Lewis rats (RT1^l) and with allograft transplantation between Lewis-Brown Norway (LBN RT1^l + n) donors and Lewis (RT1^l) recipients under low dose of cyclosporine A monotherapy. Immunologic responses were tested for donor cell engraftment and chimerism induction. All isografts survived indefinitely and allografts were viable at 200 days post-transplant under low dose of cyclosporine A. Microangiography of the graft revealed preservation of skin, muscle, and bone components. Histologic examination confirmed viability of all allograft components without signs of rejection. Long-term engraftment of donor-origin (RT1ⁿ) BMC was confirmed by donor-specific chimerism (1.2%) in peripheral blood and bone marrow (1.65%) compartments and by engraftment into lymphoid organs of recipients. The IBOMC transplant proved to be a reliable composite tissue allotransplantation (CTA) model. Moreover, because of its robust bone marrow component and large skin component, it is applicable to studies on immunologic responses in CTA.     

Interatrial shunt: diagnosis of patent foramen ovale and atrial septal defect with 64-row coronary computed tomography angiography

Purpose  

The aim of this study was to investigate the frequency with which interatrial shunts are found during routine coronary computed tomography (CT) angiography and to describe imaging characterizations of patent foramen ovale (PFO), atrial septal defect (ASD), and atrial septal aneurysm (ASA).     

Endogenous thrombospondin-1 is a cell-surface ligand for regulation of integrin-dependent T-lymphocyte adhesion

Lymphocyte adhesion to cells and extracellular matrix (ECM) via integrins plays a pivotal role for the function of the immune system. We show here that endogenous thrombospondin-1 (TSP-1) is a cell-surface ligand for cis interaction of surface receptors in T lymphocytes controlled by integrins and the T-cell antigen receptor (TCR/CD3). Stimulation of CD3 triggers rapid surface expression of TSP-1 in quiescent T cells, whereas activated cells express TSP-1 constitutively. Endogenous TSP-1 is attached to lipoprotein receptor-related protein 1 (LRP1/CD91) and calreticulin (CRT) on the cell surface through its NH2-terminal domain. Adhesion via integrins to ICAM-1 or ECM components up-regulates TSP turnover dramatically from a low level in nonadherent cells, whereas CD3 stimulation inhibits TSP turnover through interference with CD91/CRT-mediated internalization. Integrin-associated protein (IAP/CD47) is essential for TSP turnover and adhesion through interaction with the C-terminal domain of TSP-1 in response to triggering signals delivered at the NH2-terminal. These results indicate that endogenous TSP-1 connects separate cell-surface receptors functionally and regulates T-cell adhesion.     

Loop security and tensile properties of polyblend and traditional suture materials

Tensile and knot properties of new generation (polyblend) and traditional suture materials in orthopedic surgery were investigated in standard laboratory conditions. Study focused on Fiberwire No. 5 and 2, Ethibond No. 5, 2 and 00, Orthocord No. 2, MaxBraid No. 2, Prolene No. 0 and 00, PDS No. 0 and 00, and Vicryl No. 2, 0 and 00. A 27-cm suture loop was fastened with 10 knots for ten samples for each type. Test parameters were tensile load to failure, elongation at failure point and knot slippage, and volume of 10-fold knots. Results were compared using ANOVA test. Failure load of No. 5 Fiberwire (625.0 ± 30.0 N) was significantly higher compared to all other suture types. Tensile strengths of MaxBraid No. 2 (287 ± 11 N) was significantly stronger compared to two other No. 2 polyblend sutures types and Ethibond No. 5. Knot slippage of Fiberwire No. 5 (14 ± 1.9 mm) was significantly higher compared to all other suture types. Ethibond No. 2 (0.1 ± 0.3 mm) had the lowest knot slippage. Elongation at the failure point of Fiberwire No. 2 (5%) was significantly lower than all other suture types. Mean calculated knot volume of #5 Fiberwire (73 ± 6.9 mm³) was significantly higher compared to #5 Ethibond (53 ± 4.8 mm³). Results of the study proved presence of significant differences between tensile and knot properties of various suture types and sizes. Loop security of larger diameter sutures is not always higher than thinner sutures. Suture elongation and knot slippage are important failure modes for high-diameter sutures and short-suture loops.     

Evaluation of thiol-disulphide homeostasis in radiation workers

Purpose: To evaluate thiol-disulphide homeostasis – a novel, easily calculated, readily available, and relatively cheap oxidative stress marker – in radiation workers and compare the results with healthy controls.

Materials and methods: A total of 108 participants were enrolled in the study including 63 hospital workers occupationally exposed to ionizing radiation in the units of interventional radiology, interventional cardiology and nuclear medicine. A control group consisted of 45 individuals staff in the same hospital. Serum thiol-disulphide homeostasis measurement was investigated via the spectrophotometric method newly described by Erel and Ne?elio?lu.

Results: The mean serum native thiol levels of radiation workers (528.96?±?86.42?μmol/l) was significantly lower than control subjects (561.05?±?104.83?μmol/l) (p?=?.045). The mean serum total thiol levels of radiation workers (547.70?±?91.50?μmol/l) was lower than control subjects (580.36?±?112.24?μmol/l). Nevertheless, there was no significant difference between total thiol of exposed workers and controls.

Conclusions: The results show that long-term low dose ionizing radiation may lead to oxidative stress and have side-effects in antioxidant thiol groups. We may suggest supporting radiation workers by safe antioxidant nutritional formulations and following up via both physical dosimetry and biodosimetric methods.     

Diagnostic value of color Doppler ultrasonography and MDCT angiography in complications of hemodialysis fistulas and grafts

Purpose

The purpose of the study was to compare the diagnostic value of color Doppler ultrasonography (CDUS) and multidetector computed tomography (MDCT) angiography against that of digital subtraction angiography (DSA) or surgery in the evaluation of failing hemodialysis arteriovenous fistulas (AVFs).

Materials and methods

CDUS and MDCT angiography were performed with 41 patients (24 men, 17 women; mean age 55.8) with dysfunctional hemodialysis fistulas. The presence of stenosis, thrombosis, aneurysm, pseudoaneurysm and seroma were recorded. The sensitivity, specificity, positive and negative predictive values (PPV and NPV) and accuracy of CDUS and MDCT angiography were calculated both individually and in combination for the detection of vascular segments with significant stenosis, thrombosis, aneurysms, pseudoaneurysms, perivascular complications and stenosis subgroups.

Results

Sixty-four segmental lesions were diagnosed by DSA or surgery. Sensitivity, specificity, PPV, NPV and accuracy of CDUS for all vascular tree lesions were 85.9%, 99.2%, 96.4%, 96.7% and 94.5%, respectively. For MDCT angiography the figures were 96.8%, 99.6%, 98.4%, 99.2% and 98.5%, respectively. When both tests were used in combination, sensitivity, specificity, PPV, NPV and accuracy for all vascular tree lesions rose to 100%.

Conclusion

Combined use of MDCT and CDUS for diagnosis of AVF dysfunctions is of equivalent value to surgery or DSA, a gold standard technique.     

Initial experience of 3 tesla apparent diffusion coefficient values in differentiating benign and malignant thyroid nodules

Purpose:

To evaluate the role of diffusion‐weighted magnetic resonance imaging (DWMRI) in differentiating benign and malignant thyroid nodules using a 3 Tesla (T) MRI scanner.

Materials and Methods:

Twenty‐eight nodules in 25 patients and 14 healthy control cases were included in the study. DWMRI was acquired with 6 b values with a 3T MRI scanner. The apparent diffusion coefficient (ADC) values of the nodules were calculated from reconstructed ADC map images and were compared with the final histopathological diagnoses.

Results:

The mean ADC value of the benign nodules was 1548 ± 353.4 (×10^?6 mm²/s), and the mean ADC of the malignant nodules was 814 ± 177.12 (×10^?6 mm²/s). The normal thyroid tissue had a mean ADC value of 1323.43 ± 210.35 × 10^?6 mm²/s (958–1689 × 10^?6 mm²/s) in the healthy control group. The ADC values were significantly different among the three groups (P = 0.001). An ADC value of 905 × 10^?6 mm²/s was determined to be the cutoff value for differentiating benign and malignant nodules, with 90% (55.5–98.3) sensitivity and 100% (81.3–100.0) specificity.

Conclusion:

This study suggests that the ADC values of nodules measured with a 3T MRI scanner could help in differentiating benign thyroid nodules from malignant nodules. J. Magn. Reson. Imaging 2013;37:1077–1082. © 2012 Wiley Periodicals, Inc.

     

MR fluoroscopy-guided transthoracic fine-needle aspiration biopsy: feasibility

The purpose of this study was to evaluate the feasibility of using an open-configuration magnetic resonance (MR) imaging system with MR fluoroscopic guidance to perform percutaneous transthoracic fine-needle aspiration biopsy in patients with lung masses. Percutaneous transthoracic aspiration biopsies were performed with MR fluoroscopic guidance in 14 patients. The masses were 2-7 cm in diameter (mean, 4.1 cm). The needle was positioned by using a free-hand technique with MR fluoroscopic guidance. The needle tip reached the target lesion, and biopsy was performed. Analysis of the biopsy specimens facilitated a specific diagnosis in all patients. Pneumothorax was noted in two patients (14%) with chronic obstructive pulmonary disease. Study results showed that the described MR fluoroscopy-guided transthoracic biopsy technique can be used safely and successfully for lung masses. MR fluoroscopy can be used to reach the target lesion easily and accurately.