En Bloc Liver Kidney Transplantation Using Donor Splenic Artery as Inflow to the Kidney: Report of Two Cases.

The number of simultaneous liver-kidney transplants has been increasing. This surgery is associated with an increased risk of complications, longer duration of surgery and longer ischemia time for the renal allograft. Two patients listed for liver-kidney transplant at our center underwent en bloc combined liver-kidney transplantation using donor splenic artery as inflow. Patient 1 previously underwent cardiac catheterization that was complicated by a bleeding pseudoaneurysm of the right external iliac artery that required endovascular stenting of the external iliac artery and embolization of the inferior epigastric artery. Patient 2 was on vasopressor support and continuous renal replacement therapy at the time of transplant. In this paper, we described a novel technique of en bloc liver-kidney transplant with simultaneous reperfusion of both allografts using the donor splenic artery for renal inflow. This technique is useful for decreasing cold ischemia time and total operative time by simultaneous reperfusion of both allografts. It is a useful technical variant that can be used in patients with severe disease of the iliac arteries.

Management of duodenal injuries in children.

BACKGROUND/PURPOSE: The natural history and management of pediatric duodenal injuries are incompletely described. This study sought to review injury mechanism, surgical management, and outcomes from a collected series of pediatric duodenal injuries. METHODS: A retrospective chart review was conducted for a 10-year period of all children less than 18 years old treated for duodenal injuries at 2 pediatric trauma centers. RESULTS: Forty-two children were treated for duodenal injuries. There were 33 blunt and 9 penetrating injuries. Injuries were classified using the Organ Injury Scale for the Duodenum. Twenty-four patients underwent operative management by primary repair (18), duodenal resection and gastrojejunostomy (4), or pyloric exclusion (2). Duodenal hematomas were treated nonoperatively in 94% of cases. The average ISS for operative versus nonoperative cases was 23 and 10, respectively. Delay in diagnosis or operative intervention (>24 hours) was associated with increased complication rate (43% v 29%) and hospitalization (32 v 20 days). Nine children requiring surgery experienced delays and were most highly associated with foreign body, child abuse, and bicycle injuries. There were no deaths caused by duodenal injuries. CONCLUSIONS: Duodenal injuries in children were predominantly blunt and had a low mortality rate. When surgery was required, primary repair was usually feasible.

Three-dimensional imaging of embryonic mouse kidney by two-photon microscopy.

Developing mammalian embryonic kidney becomes progressively more elaborate as the ureteric bud branches into undifferentiated mesenchyme. Morphological perturbations of nephrogenesis, such as those seen in inherited renal diseases or induced in transgenic animals, require careful and often tedious documentation by multiple methodologies. We have applied a relatively quick and simple approach combining two-photon microscopy and advanced three-dimensional (3-D) imaging techniques to visualize and evaluate these complex events. As compared with laser confocal microscopy, two-photon microscopy offers superior optical sectioning deep into biological tissues, permitting analysis of large, heterogeneous, 3-D structures such as developing mouse kidney. Embryonic and newborn mouse kidneys were fluorescently labeled with lectins, phalloidin, or antibody. Three-dimensional image volumes were then collected. The resulting volume data sets were processed using a novel 3-D visualization technique. Reconstructed image volumes demonstrate the dichotomous branching of ureteric bud as it progresses from a simple, symmetrical structure into an elaborate, asymmetrical collecting system of multiple branches. Detailed morphology of in situ cysts was elucidated in a transgene-induced mouse model of polycystic kidney disease. We expect this integration of two-photon microscopy with advanced 3-D image analysis will provide a powerful tool for illuminating a variety of complex developmental processes in multiple dimensions.

Three-dimensional modeling of the effects of parathyroid hormone on bone distribution in lumbar vertebrae of ovariectomized cynomolgus macaques.

Biomechanical and quantitative computed tomography (QCT) analyses showed beneficial effects of parathyroid hormone (PTH (1-34)) on lumbar vertebrae from ovariectomized monkeys, even after withdrawal of treatment for 6 months. Adult cynomolgus monkeys were randomized, ovariectomized (except for sham ovariectomy controls), and treated subcutaneously with vehicle (OVX) or 5 micrograms/kg per day PTH (1-34) (PTH5) for 18 months. An additional group was treated subcutaneously with 5 micrograms/kg per day PTH (1-34) (PTH5W) for 12 months and then switched to vehicle for the remaining 6 months. Lumbar vertebrae were excised at necropsy, and L5 were serially scanned by QCT, using 70 x 70 x 500 microns voxels. PTH increased volumetric bone mineral density (BMD, mg/cm3) and bone mineral content (BMC, mg) for both PTH5 and PTH5W compared with OVX and Sham without inducing hypermineralization, without stimulating periosteal expansion, and without significant constriction of the neural canal. BMD values for the voxels were then averaged to create nearly isotropic voxels of 490 x 490 x 500 microns. Serial scans were stacked and a triangular surface mesh generated for each bone, using a 'marching cubes' algorithm. A smoothed version of each surface mesh was used to generate a tetrahedral element for three-dimensional finite element modeling. An isotropic Young's modulus for each tetrahedral element was calculated as a function of the original voxel BMDs. Linear elastic stress analysis was then performed for each finite element model in which a distributed load of 100 newtons (N) was applied to the top surface of the centrum, perpendicular to the bottom surface with the bottom surface constrained in the direction of loading. Analysis of the effective strain showed considerable reduction in vertebral strain for both PTH5 and PTH5W, compared with OVX. Compression testing of the adjacent L3 and L4 confirmed that vertebral strength and stiffness for PTH5 and PTH5W were significantly greater than for OVX. Histogram and QCT analyses showed PTH conversion of low-density bone (trabecular bone) into medium-density bone (more and thicker trabeculae) by stimulating bone apposition. PTH withdrawal induced conversion of medium-density into low-density and high-density bone with the latter higher than in OVX. These data show that even transient PTH treatment improves vertebral architecture and bone quality to reduce the likelihood of fracture, and that transient treatment is better than no PTH treatment at all.

Apical membrane permeability of MDCK cells.

The osmotic water permeability (Pf) and permeability to nonelectrolytes were determined for the apical membrane of clonal strain Madin-Darby canine kidney (MDCK) C12 cells cultured as cysts with the apical membrane facing the surrounding medium. Pf and solute permeabilities were calculated from the rate of volume change of cysts by digitizing images at 1-s intervals after instantaneous osmotic challenge. Image measurement was fully automated with the use of a program that separated the image of the cyst from the background by using adaptive intensity thresholding and shape analysis. Pf, calculated by curve fitting to the volume loss data, averaged 2.4 +/- 0.1 micron/s and was increased by addition of amphotericin B. The energy of activation for Pf was high (16.3 kcal/mol), and forskolin (50 microM) had no effect on Pf. Two populations of MDCK cysts were studied: those with two to three cells and those that appeared to be composed of only one cell. The Pf of multicell cysts was the same as single cell cysts, suggesting that paracellular water flow is not significant. Solute permeability was measured using paired osmotic challenges (sucrose and test solute) on the same cyst. Urea permeability was not different from zero, whereas the permeabilities of acetamide and formamide were consistent with their relative oil-water partition coefficients. Our data are similar to values from studies on the permeability properties of vesicles of water-tight epithelial apical membrane. The combination of the unique model of MDCK apical-out cysts and fully automated data analysis enabled determination of apical membrane permeability in intact epithelial cells with high precision.

Ultrastrucure of the superior oblique tendon.

Individual collagen fibers in the superior oblique tendon of patients with superior oblique palsy studied at 60,000x with transmission electron microscopy are fewer in number and larger in diameter when compared to normal fibers. The relationship of these changes to function and to gross morphologic changes are not clear.

Ultrasound and the blood-brain barrier.

High intensity focused ultrasound was employed to modify the permeability of the normal feline and canine blood-brain barrier (BBB) to a circulating vital dye--Evans blue (EB). The threshold doses (W sec/cm2) for focally increasing the permeability of the BBB in white matter (WM) and gray matter (GM) were as follows: internal capsule (WM)--340 to 680; thalamus (GM)--approximately 1326; and caudate nucleus (GM)--2284 to 2952. In the presence of supralesioning doses of ultrasound, the cross sectional area occupied by the EB was consistently greater than that of the attendant nonhemorrhagic lesion--thus suggesting that BBB changes may be inducible at sublesioning doses. These findings, in conjunction with those of others, suggest that high intensity focused ultrasound may have a role in the treatment of brain tumors based on cell destruction by two mechanisms: (a) direct, by the ultrasound and (b) indirect, by an antineoplastic agent which is delivered via an ultrasonically modified BBB.

High frequency ultrasonic imaging of skin: experimental results.

Experimental results are presented demonstrating the application of pulse echo ultrasound to imaging the skin. A laboratory prototype B-mode mechanical scanner was employed to obtain images of human skin, both in vitro and in vivo, using broadband pulsed ultrasound at 25 MHz. Images were formed by processing digitized A-mode waveforms and displaying the resulting two-dimensional cross sections using a digital imaging system. Images obtained by rectifying the A-modes are compared to those derived using a software-based cross-correlation technique. Scans of test targets demonstrate that an axial resolution of 100 m can be achieved at 25 MHz when the digital correlation method is employed. Lateral resolution is limited by the 0.25 mm half-power focal beamwidth of the transducer. Seventeen in vitro ultrasonic scans of human skin were compared to frozen section histology. Average skin depth was well correlated between the two techniques ( = 0.99, p less than 0.001). Application of cross-correlated processing to 25 MHz in vivo images produced good delineation of epidermis, papillary, and reticular dermis. Conversion to a 50 MHz transducer did not delineate skin layers as well as the 25 MHz transducer due to inherent difficulties with transducer reverberations.

Ultrasonic diagnostic system for interactive interrogation of adult brain through intact skull.

An integrated ultrasonic system has been developed employing static gray scale imaging, digital image processing, and analyses of quantitative ultrasonic backscatter for interactive interrogation of brain through the adult human skull. Operating at 750 kHz, to avoid severe spatial and temporal pulse distortion which accompany ultrasonic transkull transmission at higher frequencies, storage and image processing of successive images taken at selected gain settings in the same image plane allow the reconstruction of a composite cross-section of the brain and skull and enable visualization of internal brain structure. Analyses of digitized backscatter data obtained with the visualization transducer over selectable interrogation paths referenced to the cross-sectional image permit quantitative classification of tissue type independent of qualitative visual image analysis, such that enhanced diagnostic potential is provided. A previous paper described in detail the modifications of the commercial ultrasound diagnostic unit which serves as the core of this system. The present paper presents the rationale for the integrated system design approach, as well as a description of graphics display and tissue classification features which have been incorporated into the instrumentation configuration and are deemed necessary for successful transkull ultrasonic imaging and diagnosis.