Patterns of cytokine secretion in murine leishmaniasis: correlation with disease progression or resolution.

Susceptibility or resistance to infection with Leishmania major correlates with the ability of mice to produce characteristic panels of lymphokines in response to the parasite. To investigate the role of antigen-presenting cells in this phenomenon, we developed a model system which used congenic (H-2d) susceptible and resistant mice. L. major-specific T cells were isolated from infected BALB/c and B10.D2 mice, and the cells were restimulated in vitro on syngenic or congenic antigen-presenting cells. BALB/c L. major-reactive T cells restimulated with either antigen-presenting cell produced high levels of interleukin-4 and low levels of gamma interferon. In contrast, T cells from B10.D2 mice produced gamma interferon. Radiation-induced chimeras reconstituted with BALB/c bone marrow also produced more interleukin-4 in response to L. major than did chimeras reconstituted with B10.D2 bone marrow. To test whether this pattern of cytokine secretion was unique to infection with L. major, we infected the mice with a second intracellular pathogen, Mycobacterium bovis BCG. Mycobacterium-specific T cells from both BALB/c and B10.D2 mice produced interleukin-2 and no interleukin-4. Finally, when BALB/c mice were vaccinated with avirulent L. major, the induced resistance correlated with reduced production of interleukin-4 but no increase in gamma interferon production. Instead, T cells from the vaccinated mice produced high levels of tumor necrosis factor. This suggests that tumor necrosis factor, in addition to gamma interferon, may be involved in resistance to L. major and that interleukin-4 may inhibit the leishmanicidal activity of tumor necrosis factor and/or gamma interferon.     

Half‐fourier‐acquisition single‐shot turbo spin‐echo (HASTE) MRI of the lung at 3 Tesla using parallel imaging with 32‐receiver channel technology

Purpose

To assess the feasibility of half‐Fourier‐acquisition single‐shot turbo spin‐echo (HASTE) of the lung at 3 Tesla (T) using parallel imaging with a prototype of a 32‐channel torso array coil, and to determine the optimum acceleration factor for the delineation of intrapulmonary anatomy.

Materials and Methods

Nine volunteers were examined on a 32‐channel 3T MRI system using a prototype 32‐channel‐torso‐array‐coil. HASTE‐MRI of the lung was acquired at both, end‐inspiratory and end‐expiratory breathhold with parallel imaging (Generalized autocalibrating partially parallel acquisitions = GRAPPA) using acceleration factors ranging between R = 1 (TE = 42 ms) and R = 6 (TE = 16 ms). The image quality of intrapulmonary anatomy and subjectively perceived noise level was analyzed by two radiologists in consensus. In addition quantitative measurements of the signal‐to‐noise ratio (SNR) of HASTE with different acceleration factors were assessed in phantom measurements.

Results

Using an acceleration factor of R = 4 image blurring was substantially reduced compared with lower acceleration factors resulting in sharp delineation of intrapulmonary structures in expiratory scans. For inspiratory scans an acceleration factor of 2 provided the best image quality. Expiratory scans had a higher subjectively perceived SNR than inspiratory scans.

Conclusion

Using optimized multi‐element coil geometry HASTE‐MRI of the lung is feasible at 3T with acceleration factors up to 4. Compared with nonaccelerated acquisitions, shorter echo times and reduced image blurring are achieved. Expiratory scanning may be favorable to compensate for susceptibility associated signal loss at 3T. J. Magn. Reson. Imaging 2009;30:541–546. © 2009 Wiley‐Liss, Inc.     

Predicting late-onset growth abnormalities using growth velocity between trimesters

Objectives.?To determine whether growth velocity parameters derived from routine prenatal ultrasound measurements at first, second and third trimester can identify normal growth at term as well as late-onset growth abnormalities.

Material and methods.?Longitudinal study of fetal growth in normal singleton pregnancies with three normal ultrasound examinations and delivered at term. Fetuses were classified into 3 groups (?<?10th percentile, 10–90th percentile, >?90th percentile) based on birth weight. Multiple regression on birth weight classification was used to build up a prediction equation of fetal growth potential (FGP) based on fetal biometry and fetal growth velocity parameters between ultrasound examinations. Best cut-off value for FGP predicting growth restriction and macrosomia were defined.

Results.?356 pregnancies were included. Fetal biometry growth velocities between examinations were calculated for all measurements. Using best cut-off values, the estimated sensitivity, specificity and odds ratio were: 60% [44;74], 91%[89;92] and 14.55 [6.30;33.98] and 53% [36;69], 89%[88;91] and 10 [4.27;23.49] for the prediction of growth restriction and macrosomia, respectively.

Discussion.?Fetal growth potential can be derived and calculated from standard ultrasound measurements. It can improve identification of these fetuses at risk for late-onset growth abnormalities and their related morbidity.     

Rotator cuff lesions of the shoulder: evaluation by direct sagittal CT arthrography

Direct sagittal computed tomographic scanning (DSCT) of the shoulder was performed in 42 symptomatic patients, six healthy volunteers, and two cadaver shoulders. Axial CT scanning and double-contrast arthrography with plain radiographs were performed in 41 patients for comparison. DSCT enabled correct identification of 27 of 29 lesions in 24 patients. Seventeen patients had normal shoulders. Axial CT scanning and DSCT together enabled correct identification of all lesions and were markedly superior to plain-film arthrography. DSCT enabled diagnosis of all cases of complete rotator cuff tear plus three cases of incomplete tear and three of rotator cuff atrophy not identified by the other techniques. Axial CT scanning was better than DSCT for diagnosis of Bankart lesions.     

Avidin-biotin affinity chromatography: application to the isolation of human placental insulin receptor.

The ligand N alpha, B1-(6-biotinylamido)hexanoyl-insulin was attached noncovalently to Sepharose 4B immobilized succinoylavidin to form an insulin-affinity resin. This resin was used to isolate highly purified insulin receptor from human placental tissue by a four step process involving (i) preparation of a crude membrane fraction, (ii) solubilization with Triton X-100, (iii) wheat germ agglutinin purification, and (iv) insulin-affinity chromatography. NaDodSO4/PAGE of the purified 125I-labeled receptor under nonreducing conditions showed the presence of a major component with an approximate molecular weight of 350,000 and a minor component with a molecular weight of approximately equal to 166,000. Based on the assumption that the degree of labeling is comparable in both components, the material corresponding to the Mr 350,000 peak represents approximately equal to 94% of the receptor preparation as determined by scanning the autoradiograms. The specific insulin binding capacity of the preparation is 18 +/- 6 micrograms of 125I-labeled insulin per mg of protein as determined by the polyethylene glycol assay and analyzed by Scatchard plot. Insulin binding activity was stable at 4 degrees C and pH 7.6 for at least 12 weeks but was destroyed by freezing and thawing. The availability of highly purified receptor afforded the opportunity to explore its precipitability by polyethylene glycol under assay conditions. Whereas trichloroacetic acid precipitated 95% of the 125I-labeled receptor, polyethylene glycol precipitated only 30%. If the specific activity of the receptor is corrected for incomplete precipitability by polyethylene glycol, the apparent specific binding would be 3.5 +/- 1.2 mol of insulin per mol of receptor. These results are in disagreement with the current receptor model, which postulates that 1 mol of receptor (Mr, 350,000) binds 2 mol of insulin. Clearly, the problems associated with the method available for determining insulin binding are sufficiently serious to preclude their use in determining receptor valence.     

109Use of EPR Spectroscopy to Measure Tissue Oxygen in an Ischemic Flap Model

Methods to reliably measure tissue oxygenation in situ are currently lacking. We have developed a vertically oriented, dorsal, bipedicle flap model that is easy to perform, reliably reproduces tissue ischemia, eliminates craniocaudal variation, and is amenable to studying therapeutic modalities. The effect of narrowing this flap on tissue oxygenation measured with Licox electrodes has previously been presented. In this study we utilize in situ EPR spectroscopy to demonstrate the oxygen gradient in the flap as a function of flap width and placement of a silicone sheet directly under the flap. The effect of wound healing over a 2 week period is demonstrated. Twenty four, 300 gm male Sprague‐Dawley rats underwent creation of the bipedicle flap according to the following groups: 2.5 cm flap with silicone, 2.0 cm flap without silicone, 2.0 cm flap with silicone. Each group of 6 animals was injected with EMS char at 2 cm intervals along the flap and one injection in the control, non‐ischemic tissue. A 4^th group underwent 2.0 cm flaps with silicone and use of lithium phthalocyanin as the paramagnetic material. Wound measurements and EPR spectroscopy were performed on days 3, 7, 10 and 14. On day 14, after EPR measurements, the animals were sacrificed and their wounds excised. One flap and one control wound were preserved for histologic analysis, the other flap and control wounds were prepared for lactate measurements. EPR spectroscopy demonstrated a gradient of oxygen that was lowest in the center of the flap and greatest at either end. Changes in the oxygen gradient correlated with narrowing and placement of the intervening silicone sheet. This new technology has never been utilized in an animal model of impaired wound healing. Comparison of recently developed paramagnetic materials for optimal tissue oxygen and free radical measurements will be presented.     

Soluble CD30 concentrations in ESRD patients with and without panel reactive HLA antibodies

BACKGROUND: In this retrospective study we compared accuracy of panel reactive antibodies (PRA) with serum soluble CD30 (sCD30) contents in predicting acute rejection crisis post-renal transplant. METHODS: Pre-transplant sera from 115 patients were evaluated for their PRA and sCD30 concentrations. All patients received calcineurin inhibitor-based immunosuppressive therapy. Objective measurements for rejection were biopsy-proven acute rejection (AR) episodes within first six months of the transplant. Post-transplant sera of patients with AR were tested for the presence of donor-specific HLA antibodies (DSA). RESULTS: Overall AR rate was 16% (18/115). Patients positive for PRA and sCD30 tests were at significantly higher risk for AVR compared with those patients negative for both the tests (36% vs. 5%, p=0.01). Among negative PRA patients risk for AR was significantly elevated if they were also tested positive for sCD30 concentrations (21% vs. 5%, p=0.04). Of the 18 patients with AR, 14 were positive for sCD30, and 13 of them (93%) developed DSA post-transplant (p=0.001). CONCLUSION: These data showed that patients positive for sCD30 contents are at high risk for the development of DSA and AR post-transplant regardless of their pre-transplant PRA.