Early aspirin therapy may reduce hepatic artery thrombosis in liver transplantation.

BACKGROUND: Hepatic artery thrombosis (HAT) remains among the leading causes of early graft loss after liver transplantation. Our transplant center began using universal aspirin prophylactic therapy immediately posttransplantation in 2007. The aim of this study was to determine the safety and efficacy of early aspirin therapy on clinical outcomes. METHODS: This large-scale, cross-sectional analysis included all adult liver transplantations performed between 2000 and 2009. Pediatric and multiorgan transplants were excluded. Patients were grouped and compared based on whether they received early initiation of aspirin 325 mg PO daily posttransplantation. RESULTS: A total of 541 adult liver transplantations occurred during the study period; 439 had complete documentation and were analyzed. Clinical outcomes show aspirin patients had similar rates of early and late HAT, but had significantly lower early HAT, defined as HAT occurring within the first 30 days posttransplant, leading to graft loss. Other clinical outcomes were similar between groups including bleeding events and wound complications. CONCLUSIONS: Immediate initiation of aspirin therapy after liver transplantation may reduce the rate of HAT leading to early graft loss, without increasing bleeding or other complication rates.

Case report: gastrointestinal hemorrhage caused by a pancreas transplant arteriovenous fistula with large psuedoanuerysm 9 years after transplantation.

Reported cases of arteriovenous fistulae in transplant recipients are uncommon. We present a case of an arteriovenous fistula associated with a large pseudoaneurysm in the root of the small bowel mesentery of a pancreas transplant. Uniquely, in our case, the arteriovenous fistula presented with an episode of gastrointestinal (GI) hemorrhage 9 years postoperatively. Radiographic imaging including coronal computed tomography angiogram and conventional angiogram demonstrated an arteriovenous fistula in the patient's pancreas transplant between the distal superior mesenteric artery (SMA) and superior mesenteric vein (SMV) with 6 cm aneurysmal dilatation. The tremendous flow in the fistula in the root of the graft small intestine mesentery led to graft duodenal mucosal congestion and lower GI hemorrhage. After successful embolization of the SMA-SMV fistula and pseudoaneurysm using interventional radiographic techniques, the arteriovenous fistula remained thrombosed. The patient had no further episodes of GI bleeding and her endoscopic evaluation was otherwise negative. The presence of arteriovenous fistulae and pseudoaneurysms in pancreas transplant recipients is uncommon, but has been previously documented. This case is further distinguished from previous reports by the notable 9-year interval between transplantation and the onset of hemorrhage. Historically, symptomatic vascular malformations have been associated with significant patient morbidity and mortality. Successful patient management involves timely and accurate diagnosis and intervention.

Potential differences in kidney allograft outcomes between ethnicities when converting to sirolimus base immunosuppression.

OBJECTIVE: The aim of this study was to determine whether ethnicity impacts graft outcomes in kidney transplant patients converted to sirolimus (SRL) and maintained on either calcineurin inhibitors (CI) or mycophenolate mofetil (MMF) with steroids. METHODS: This study analyzed kidney transplants converted to SRL and transplanted between July 1991 and April 2007. Patients were divided into 4 groups: group 1: African-Americans converted to SRL + CI; group 2: non-African-Americans converted to SRL + CI; group 3: African-Americans converted to SRL + MMF; group 4: non-African-Americans converted to SRL + MMF. RESULTS: A total of 242 patients was included. Demographics, baseline immunosuppression, and reason for SRL conversion were similar among groups. Patients converted to SRL + CI regimens had significantly higher rates of acute rejection before SRL conversion, but equal rates after conversion. Development of proteinuria was similar across groups. African-American patients converted to SRL + MMF tended to have poorer outcomes compared with African-American patients converted to SRL + CI. Non-African-American patients converted to SRL + MMF tended to have better graft outcomes compared with non-African-American patients converted to SRL + CI. CONCLUSIONS: African-Americans converted to SRL may benefit from continued CI, whereas non-African-Americans converted to SRL seem to have better outcomes with MMF. Further prospective studies are warranted to confirm these findings.

Long-term efficacy of induction therapy with anti-interleukin-2 receptor antibodies or thymoglobulin compared with no induction therapy in renal transplantation.

BACKGROUND: Although the utility of antibody induction therapy has been demonstrated in clinical trials, the ideal regimen to use based on patient risk factors has not been fully elucidated. The objectives of this study were to determine the impact of either anti-interleukin-2 receptor antibodies (IL-2RA) or thymoglobulin induction therapies versus no induction therapy on acute rejection rates and on 3-year graft survival rates. METHODS: This retrospective analysis compared 3 patient groups-those who did not receive induction, those who received IL-2RA induction, and those who received thymoglobulin induction. RESULTS: Three hundred eleven patients were included in this study. Patients were well matched for demographic and immunologic characteristics in the noninduced and IL-2RA induction therapy groups; the thymoglobulin induction group included significantly higher risk patients. The acute rejection rates were significantly lower in the IL-2RA and thymoglobulin groups when compared with the no induction therapy group (28% vs 15% vs 41%, respectively; P = .001), which was confirmed with multivariate analysis. The 3-year graft loss rates (no induction 21% vs IL2-RA induction 19% vs thymoglobulin induction 25%; P > .50) and creatinine concentrations (no induction 1.8 +/- 0.7, IL-2RA induction 2.0 +/- 1.0, and thymoglobulin induction 1.9 +/- 1.2; P = .47) were similar between all groups. CONCLUSION: The use of induction therapy significantly reduces the incidence of acute rejection. The use of thymoglobulin induction equalizes 3-year graft survival rates in high-risk patients to those seen in low-risk patients receiving either no induction or IL-2RA induction.

Polarization-modulated second harmonic generation imaging: method for quantitative assessment of disorganization in anulus.

An experimental method for quantifying disorder within the anulus fibrosus is described based on polarization-modulated second harmonic generation imaging (PM-SHG-I). This method is demonstrated by imaging the anular lamellar architecture of a mouse model of compressive loading. Results were consistent with those obtained in an earlier study where organization was quantified directed secants image analysis on photomicrographs. In this study the orientation within individual lamellia is quantified by average orientation of the collagen molecules within a defined volume of a single lamellar as measured by the PM-SHG-I. Lamellar boundaries can be identified through the SHG intensity images, and confirmed through co-registration with photomicrographs of the same region. The orientation within the lamellar is quantified by the polarization angle of the maximum second harmonic intensity. PM-SHG-I offers several advantages as compared with the method of directed secants: first, it is nondestructive, allowing repeated measurements of the same tissue; second, images are captured on the order of seconds and capable of obtaining information up to a depth of 200-300 microns, thus allowing for real-time assessment of load damage; third, organization is measured at a much higher resolution, as it is based on disorder within the molecular arrays of a single lamella.

O2-dependent prostanoid synthesis activates functional PGE receptors on corpus cavernosum smooth muscle.

We have previously demonstrated that decreased O2 tension inhibits prostaglandin synthesis from human corpus cavernosum smooth muscle cells in static culture over 8-18 h (R. B. Moreland et al., Molecular Urology 2: 41-47, 1998). In this report, an experimental system was designed that allowed determination of the effects of O2 tension changes over the time frame of physiological penile erection. Human corpus cavernosum smooth muscle cells were cultured on microcarrier beads in enclosed stirrer flasks so that rapid changes of O2 tension could be modulated. After 18 h of equilibration at 30-40 mmHg to simulate blood PO2 at penile flaccidity, O2 tension was increased to 100 mmHg for 1 h and then returned to 30-40 mmHg. Media samples were withdrawn for prostanoid synthesis and cell samples were taken for cAMP determinations. After 18 h of 30-40 mmHg PO2 values, prostanoid synthesis by human corpus cavernosum smooth muscle cells was low (0.1-0.7 pmol/10(6) cells). When PO2 was increased to 100 mmHg, a rapid increase in PGE2 >> PGF2alpha > PGD2 was observed (thromboxane A2 was undetectable), which peaked at 5.7 pmol PGE2/10(6) cells. Increased O2 tension correlated with increased PGE2 and increased intracellular synthesis of cAMP. The prostaglandin G/H synthase inhibitor indomethacin or the E prostanoid (EP2)-selective antagonist AH-6809 each inhibited the O2-tension-dependent increases in cAMP. These data support a role of differential O2 tension in the penis in the smooth muscle synthesis of PGE2, which in turn increases cAMP synthesis via EP2 receptors.

Autosomal dominant familial frontonasal dermoid cysts: a mother and her identical twin daughters.

A dermoid cyst is an ectodermal cyst that contains an epithelial lining as well as adnexal structures, and may occur in numerous areas of the body. The nasal dermoid accounts for 1% of all dermoid cysts and 3-12% of head and neck dermoid cysts. While there have been familial cases reported, a genetic inheritance for nasal dermoids has not been suggested. We present the first reported case of a mother and her identical twin daughters who were all found to have evidence of frontonasal dermoid cysts. Our case and a review of literature seem to implicate an autosomal dominant inheritance in certain instances of nasal dermoids.

Healing large tympanic membrane perforations using hyaluronic acid, basic fibroblast growth factor, and epidermal growth factor.

Large tympanic membrane perforations usually require a surgical tympanoplasty for closure. Reducing surgical costs and risks has encouraged investigators to examine nonsurgical office procedures for healing these perforations. Growth accelerators are the most promising agents. We study here the closure of large acute perforations using weekly applications of 1 mg of 1% hyaluronic acid (HA), 0.4 microg basic fibroblast growth factor (bFGF), or 1.0 microg epidermal growth factor (EGF) directly to the tympanic membranes of the experimental ears. Control ears were treated with 0. 1 mL Vasocidin. Complete closure was obtained in 100% of the ears treated with HA and EGF and 85.7% of those treated with bFGF by day 21, compared with 63.6% of the controls by day 32. Moderate-to-severe ipsilateral and contralateral external canal hypertrophy was noted in 14.2% and 37.5% of the ears treated with bFGF and HA, respectively, but was not seen in ears treated with EGF or in the control group.

The stability of proton T2 effects of oxygen-17 water in experimental cerebral ischemia.

The gerbil model of unilateral cerebral ischemia has been used to test the temporal and spatial stability of the MRI T2 effects of oxygen-17 water. Following unilateral carotid ligation, symptomatic animals were given a single large intraperitoneal injection of H2(17)O and the distribution and stability of the brain T2 effects were followed with a spin-echo sequence. In contrast to the ischemic areas, the perfused tissue shows a marked and prolonged loss in intensity with little evidence of diffusion of the T2 effect of 17O into the ischemic tissue.

Improved sensitivity of proton MR to oxygen-17 as a contrast agent using fast imaging: detection in brain.

The potential utility of H2(17)O as a contrast agent has been demonstrated in biological solutions and isolated tissues but its use has been impaired by the need to run heavily T2-weighted spin-echo images. By choosing an appropriate steady-state free precession experiment sensitive to T1/T2, we have improved the available contrast-to-noise per unit time by more than a factor of 5. This allows easy measurement of the proton effects for concentrations as low as 0.4% H2(17)O in less than 1 min. Injection into small animals produces a marked reduction in the overall image intensity. Consecutive imaging at the rate of one every 52 s has been used to follow the rate of change in brain image intensity immediately after injection.

Multiple field strength in vivo T1 and T2 for cerebrospinal fluid protons.

To estimate the feasibility of measuring in vivo CSF protein, oxygen, or other solutes through their effect on proton relaxation times, the T1 and T2 of CSF protons has been measured within the human lateral ventricles. T1 was measured at 6.25, 25.4, and 60.1 MHz with a two-point method. T2 was measured at 6.25 and 25.4 MHz using the CPMG sequence to acquire 8 echo images. The T1 was 4.3 s with no evidence of field dependence. The T2 was 2 s. Although these values approach those for water at the same temperature it is possible that the T1 is influenced by the normal oxygen concentration. Calculations based on the relaxivity of dissolved protein indicate that the use of these methods for the detection of elevated levels of CSF protein would be less sensitive than existing methods.