Cardiac allograft atherosclerosis in the rat. The effect of histocompatibility factors, cyclosporine, and an angiotensin-converting enzyme inhibitor

Cardiac transplant atherosclerosis is thought to result from immune-mediated vessel wall injury. The present experiments were designed to test whether CsA alone or in combination with the ACE-inhibitor cilazapril has any effect on graft atherosclerosis in a rat cardiac transplant model. Cardiac grafts were transplanted heterotopically into either syngeneic or allogeneic recipients and followed by daily palpation; long-surviving grafts were removed after 100 days and the extent and degree of atherosclerosis was assessed using computerized morphometry. Atherosclerosis was more extensive in grafts removed from untreated allogeneic recipients compared with syngeneic recipients; CsA treatment increased the extent of atherosclerosis in syngeneic transplants. The extent and degree of vascular occlusion in allogeneic grafts from recipients treated with 15 mg/kg of CsA every other day was not different from that in grafts removed from recipients that received initially higher CsA doses. Cilazapril had no effect on the extent of graft atherosclerosis but decreased the degree of luminal narrowing in grafts from CsA-treated recipients significantly. Some grafts showed neovascularization in the subendocardial region adjacent to organized intraventricular clots, suggesting the release of angiogenic factors from such clots; such growth factors may contribute to the atherosclerotic vessel wall reaction in this model. We conclude that CsA promotes the development of graft atherosclerosis in heterotopically transplanted syngeneic cardiac grafts in the rat. We furthermore found that cilazapril has a beneficial effect on the degree of atherosclerosis in CsA-treated recipients.

Contrast-enhanced MR imaging of the liver

Postcontrast images with a 0.1 mmol/kg dose of a gadolinium chelate with extracellular distribution, when acquired dynamically during breath holding, can improve both differential diagnosis and lesion recognition in liver MR imaging. Initial results at 0.3 mmol/kg, compared with 0.1 mmol/kg, suggest a substantial improvement in lesion identification at the high dose, as assessed by using signal intensity difference divided by noise. Of the gadolinium chelates with predominantly renal excretion, only gadoteridol is presently approved in the United States at the high dose, with limited clinical evaluation for liver imaging performed to date. For linear chelates, such as gadopentetate dimeglumine and gadodiamide injection, the degree to which release of free gadolinium ion occurs is a possible issue because of lower in vivo stability (42,43). Preliminary results with hepatobiliary gadolinium chelates and iron particulate agents are favorable with regard to efficacy, although these agents remain in clinical trials.

Maternal umbilicus: ultrasound window to the gravid uterus

Transabdominal sonograms of 68 consecutive pregnant women were reviewed retrospectively. Images of fetal parts obtained through the umbilical window (UW) were compared with those obtained through the paraumbilical window (PUW) as to (1) thickness of tissue to amniotic cavity, (2) clarity of the part imaged, and (3) noise produced. The paraumbilical tissue thickness had a mean of 18 mm; the umbilical tissue thickness, a mean of 11 mm. In patients where the difference in thickness of their paraumbilical tissue and umbilical tissue was only 0 mm to 6 mm (group 1), the UW improved clarity in 10 of 34 (29%), reduced clarity in 3 of 34 (9%), and did not change clarity in 21 of 34 (62%). Improvement of images with use of the UW was not statistically significant. However, in the group of patients with the difference in tissue thickness between the paraumbilical and umbilical areas of > 6 mm (group 2), clarity was improved in 19 of 32 (60%), reduced in 2 of 32 (6%), and was unaltered in 11 of 32 (34%). In this group the image improvement with the UW was statistically significant. Images through the UW had relatively less noise. In group 1, noise was reduced in 12 of 35 (34%). The effect of the UW on noise reduction was more significant in group 2 (tissue thickness difference > 6 mm): 24 of 31 (77%) of cases.

Chronic renal allograft rejection in the rat. Transplantation-induced antibodies against basement membrane antigens

BACKGROUND

To obtain understanding of the immunologic mechanism of chronic rejection-associated glomerular and interstitial renal damage, we investigated the humoral immune response against donor type glomerular and tubular basement membrane proteins in rats with long-surviving renal transplants with and without chronic rejection.

EXPERIMENTAL DESIGN

Sera from Lewis and Fisher 344 rats with long-surviving Fisher 344 and Lewis renal allografts were investigated by enzyme-linked immunosorbent assay and Western blot analysis using collagenase-digested renal basement membrane preparations from various strains of rats.

RESULTS

Kidneys from F344 strain donors transplanted into Lewis recipients developed glomerular lesions consistent with transplant glomerulopathy as well as chronic tubulointerstitial inflammation and fibrosis. Indirect immunofluorescence studies of the Lewis anti-Fisher 344 post-transplant sera showed the presence of antibodies that gave punctate staining in the glomeruli and bright, linear staining of the proximal tubular basement membrane. Dot blot analysis of the sera showed the presence of antibodies against Fisher and third party Brown Norway glomerular basement membranes, whereas no reactivity was found with recipient strain basement membranes. Western blot analysis with glomerular basement membrane preparations showed that the antibodies recognized several antigens under nonreducing (> 200 and approximately 100 kilodaltons) and reducing (> or = 200, approximately 200, approximately 90, approximately 50 to 60, and < 45 kilodaltons) conditions. Western blots with tubular basement membrane proteins showed antibodies against various antigens. Anti-basement membrane antibodies were not found after conventional immunizations with kidney homogenates or after transplantation of cardiac allografts. Fisher 344 rats with long-surviving Lewis renal transplants produced antibodies against laminin fragments, but these antibodies were not associated with transplant glomerulopathy.

CONCLUSIONS

We found that Lewis rats that carry a Fisher 344 renal allograft with transplant glomerulopathy produce antibodies against one or more novel antigen(s) of donor glomerular and tubular basement membranes. The role of these antibodies in the pathogenesis of transplant glomerulopathy and chronic rejection-associated tubulointerstitial inflammation remains to be established.

Glomerular capillary pressures in long-surviving rat renal allografts

Many renal transplants undergo gradual deterioration in structure and function in the months or years after transplantation. The processes that underlie this progressive decline have not been defined, and may include immunological and nonimmunological mechanisms. The present experiments were designed to investigate the glomerular capillary hydrostatic pressure in long-surviving rat renal transplants with or without chronic rejection. Stop-flow glomerular pressures were measured in F344 renal allografts with chronic rejection, syngeneic F344 grafts, and long-surviving syngeneic and allogeneic LEW grafts without chronic rejection; control measurements were done in nontransplanted intact animals or after subtotal renal ablation. Renal ablation or transplantation resulted in increased glomerular pressure in F344 but not LEW kidneys; the glomerular pressure in syngeneic F344 grafts was not different from that in allogeneic F344 grafts. There was no correlation between the mean arterial pressure and the glomerular capillary pressure. Our data suggest that the glomerular capillary pressure is determined by local intrarenal factors. The glomerular capillary pressure in allotransplanted kidneys resembles that of the donor kidney after subtotal renal ablation. The importance of increased glomerular pressure in the progressive decline of graft function of chronic rejection remains to be established.

Management of major biliary complications after laparoscopic cholecystectomy

OBJECTIVE

A total of 50 major bile duct injuries after laparoscopic cholecystectomy were managed by the Duke University Hepatobiliary Service from 1990-1992. The management of these complex cases is reviewed.

SUMMARY BACKGROUND DATA

Laparoscopic cholecystectomy is the preferred method for removing the gallbladder. Bile duct injury is the most feared complication of the new procedure.

METHODS

Review of videotapes, pathology, and management of the original operations were reviewed retrospectively, and the injuries categorized. Major biliary injury was defined as a recognized disruption of any part of the major extrahepatic biliary system. Biliary leakage was defined as a clinically significant biliary fistula in the absence of major biliary injury, i.e., with an intact extrahepatic biliary system.

RESULTS

Thirty-eight injuries were major biliary ductal injuries and 12 patients had simple biliary leakage. Twenty-four patients had the classic type injury or some variant of the classic injury. A standard treatment approach was developed which consisted of ERCP for diagnosis, preoperative PTC with the placement of stents, CT drainage immediately after the PTC for drainage of biliary ascites, and usually Roux-en-Y hepaticojejunostomy with placement of O-rings for future biliary access if necessary. Major ductal injuries were high in the biliary system involving multiple ducts in 31 of the 38 patients. Re-operation was required in 5 of the 38 patients with particularly complex problems.

CONCLUSIONS

Successful management of bile duct injury after laparoscopic cholecystectomy requires careful understanding of the mechanisms, considerable preoperative assessment by experts, and a multidisciplinary approach.

Budd-Chiari syndrome in autosomal dominant polycystic kidney disease: a complication of nephrectomy in patients with liver cysts

We report two patients with autosomal dominant polycystic kidney disease (ADPKD) who developed the Budd-Chiari syndrome following bilateral nephrectomy. Both patients had massive cystic enlargement of the liver. Neither had any other identifiable risk factors for the Budd-Chiari syndrome. We suggest that removal of the kidneys may predispose toward anatomic obstruction of the inferior vena cava or hepatic veins by liver cysts. Nephrectomy should be approached cautiously in ADPKD patients with extensive involvement of the liver by cysts.

The effect of interferon gamma on epidermal growth factor receptor expression in normal and malignant ovarian epithelial cells

OBJECTIVE

We examined the effect of interferon gamma on proliferation and epidermal growth factor receptor expression in ovarian cancer cell lines and normal ovarian epithelial cells.

STUDY DESIGN

The tritiated thymidine incorporation assay was used to assess the effect of interferon gamma on proliferation. Scatchard analysis of anti-epidermal growth factor receptor antibody binding, and Western blotting of immunoprecipitates was used to assess the effect of interferon gamma on epidermal growth factor receptor expression.

RESULTS

Although interferon gamma elicited 30% to 40% decreases in proliferation, epidermal growth factor receptor expression was strikingly increased in all four ovarian cancer cell lines. Scatchard analysis indicated that this increase occurred primarily at the cell surface, but total cellular receptor levels also were increased. In contrast, interferon gamma treatment of normal ovarian epithelial cells affected neither proliferation nor epidermal growth factor receptor levels.

CONCLUSION

Because the up-regulation of epidermal growth factor receptors by interferon gamma appears to be confined to malignant cells, interferon gamma may facilitate immunotherapy and imaging of ovarian cancers by means of immunoconjugates directed against the epidermal growth factor receptor.

Left ventricular mass quantitation using single-phase cardiac magnetic resonance imaging

Magnetic resonance imaging (MRI) has been used to measure left ventricular (LV) mass in animals with superior accuracy. However, its use in cardiac patients has been limited by the long total scan times necessitated by imaging the heart at end-diastole at each of 8 to 10 slice locations. Recent canine studies showed that LV mass may be determined accurately, with considerable timesavings, by use of sequential images throughout the cardiac cycle (single-phase MRI). Twenty normal subjects underwent spin-echo MRI to determine the relationship between LV mass computed from single-phase MRI and results obtained from the more time-consuming end-diastolic MRI (which was used as the reference standard for this study). The left ventricle was spanned with 2 interleaved series of 5 short-axis 1 cm thick slices. 5 images, evenly spaced throughout the cardiac cycle, were obtained at each slice location in all subjects. LV mass ranged from 86 to 198 g. Although end-diastolic LV mass exceeded single-phase results by an average of 5 g (p less than 0.002), there was a close correlation between the 2 (slope = 0.99; r = 0.96). Although LV mass derived from end-diastolic images exceeded single-phase results, this difference is unlikely to be clinically significant and is small compared with the standard error of echocardiographic methods. Furthermore, when the order in which single-phase images were selected was reversed, there was improved agreement with end-diastolic MRI.(ABSTRACT TRUNCATED AT 250 WORDS)

Traumatic aortic tear: screening with chest CT

Dynamic chest computed tomography (CT) was performed in 326 patients who had undergone abdominal CT for blunt trauma to evaluate the role of chest CT in screening for thoracic aortic injury. Evidence of mediastinal bleeding constituted an abnormal CT examination. The results were correlated with those from aortography in 131 patients. The chest radiographs were abnormal in 127 patients (39%). Of those 127 patients, chest CT scans were abnormal in 39 patients; an aortic tear was present in eight of those patients (21%). The remaining 88 patients had normal CT scans and no aortic injury. Of the 199 patients with normal radiographs, 15 had abnormal CT scans and 184 had normal CT scans and no aortic injury. There were no false-negative CT scans; 79% of patients with normal CT scans had false-positive chest radiographs. With CT there was a significant improvement over plain radiography in specificity, accuracy, and predictive value of positive results. If chest CT were used as an adjunct to chest radiography in the screening for traumatic aortic tear, the need for aortography would decrease by 56%. Chest CT can safely help discriminate candidates for aortography, is cost-effective, and, in hemodynamically stable patients, should be incorporated in the screening for traumatic aortic tear.

Macrophage subpopulations in normal and transplanted heart and kidney tissues in the rat

The purpose of the present study was to investigate the phenotype of macrophages that infiltrate normal and transplanted rat tissues. The macrophage monoclonal antibodies ED1, ED2, ED3, 52-1D4, ER15, and OX43, together with antibodies against lymphocyte and class II MHC antigens, were used in an indirect immunofluorescence technique with sections of normal tissues and heart and renal grafts that experienced long-term survival or rejection. A small number of ED1- and ED3-positive interstitial cells were detected in normal heart and renal tissues and their number increased dramatically in rejection. Normal heart tissue contained a population of ED2-positive cells with dendritic morphology that was not detected in renal tissue. Following transplantation, a diffuse increase of rounded ED2-positive cells was observed in heart grafts; no ED2-positive cells were detected in grafts removed after 20-30 days from nonimmunosuppressed recipients. Grafts from CsA-treated animals or grafts that survived greater than 50 days in nonimmunosuppressed recipients exhibited the interstitial dendritic pattern of ED2-positive cells. Only very few rounded ED2-positive cells were observed in renal allografts; if present, they were mostly located in the medulla. OX43, which bound in normal tissues to vessel endothelium and a population of macrophages, stained in allografts an additional small population of graft-infiltrating cells, and in F344 renal allografts a population of multinucleated giant cells. We conclude that the posttransplant macrophage infiltration pattern of heart and renal allografts, defined by the monocyte/macrophage antibodies ED1, ED3, 52-1D4, and ER15, is very similar for both types of organs, although the antibody ED2 and the endothelial-macrophage antibody OX43 revealed remarkable differences between the two types of organ allografts.

Magnetic resonance imaging of an infected urethral diverticulum: a case report

We present a case report of a urethral diverticulum where magnetic resonance imaging suggested infected contents of the urethral diverticulum besides providing superb detail of periurethral anatomy. The critical clinical question was answered.

The value of non-contrast-enhanced CT in blunt abdominal trauma

The usefulness of non-contrast CT, limited to the upper abdomen, in conjunction with conventional IV contrast-enhanced scanning was studied prospectively in 190 patients who had sustained blunt abdominal trauma. In 78, visceral injuries were confirmed at surgery or at follow-up CT. Of the patients with injuries, 14 (18%) had hyperdense hematomas on the non-contrast studies that became isodense after IV administration of contrast material. These hematomas generally were small and posed an immediate threat to life in only one patient (0.5% of all subjects). In 13% of patients with injury (5% of the total), the additional information did influence treatment planning (surgery in two and intensive conservative treatment in eight). Compared with conventional contrast scanning, the combined non-contrast-contrast technique increased the scanning time only by about 5 1/2 min, but it improved the sensitivity and accuracy of CT in detecting visceral injuries from 74% and 84% to 92% and 91%, respectively (p less than or equal to .003 and p less than or equal to .04). Although contrast-enhanced scanning alone accurately depicts visceral injuries requiring surgical treatment, the incorporation of a non-contrast sequence can detect a subgroup of patients who require intensive conservative management with bed rest and close observation. This additional information can be obtained expeditiously, with minimal additional effort or intervention. The use of non-contrast scanning alone is not recommended.

Nonoperative treatment of adult splenic trauma: development of a computed tomographic scoring system that detects appropriate candidates for expectant management

We reviewed the charts of 87 patients with documented splenic injuries resulting from blunt trauma admitted to a regional trauma referral center during the 32-month period beginning in January 1984. Delayed celiotomy was defined as surgical intervention for splenic injury after a trail of nonoperative management lasting at least 24 hours. Delayed celiotomy was not required in any of the 16 cases in the pediatric age group (age less than or equal to 17 years) who were initially managed nonoperatively. In contrast, of the 27 adults who were initially treated nonoperatively, ten (37%) ultimately required celiotomy. Although splenorrhaphy was successfully performed in 21 of 44 patients undergoing early operation, all ten of the patients requiring celiotomy after an unsuccessful trial of observation underwent splenectomy rather than a spleen-preserving procedure. Of the 27 adults who were initially managed nonoperatively, 24 had abdominal computed tomography (CT) performed during their initial diagnostic evaluation. Twenty-three of these scans were reviewed by one of the authors. A CT scoring system was developed, based on the degree of splenic parenchymal and capsular injury and the amount of fluid in the abdomen and the pelvis. Adult patients who were successfully treated without operation had a significantly (p = 0.011) lower total CT score than did patients who required delayed celiotomy. No adult with a total CT score less than 2.5 required delayed operative intervention. These data support

CT of the pancreas with a fat-density oral contrast regimen

Visualization of the head of the pancreas by CT was prospectively evaluated in two groups of 100 patients who did not have pancreatic disease. Patients were given either a fat-density oral contrast material (12.5% corn-oil emulsion and metoclopramide) or a conventional high-density oral contrast material (barium suspension or iodinated solution). There was no statistically significant difference in the subjects' tolerance to the two regimens. There was, however, a significant improvement in ability to distinguish the head of the pancreas from the duodenal C-loop when the fat-density contrast material was given. When pancreaticoduodenal discrimination was graded, patients given corn-oil emulsion and metoclopramide received an average score of 0.94, whereas those given the high-density agent received an average score of 0.74, with 1.00 being the highest possible score (p less than .005). These data suggest that for routine CT evaluation of the head of the pancreas, a combination of corn-oil emulsion and metoclopramide may be superior to the conventional high-density oral contrast agents given without metoclopramide.

The normal diameter of the fetal aorta and pulmonary artery: echocardiographic evaluation in utero

Measurements of the fetal aorta and pulmonary artery can aid in the detection and diagnosis of congenital heart defects. In a prospective study of 403 normal fetuses whose gestational ages were between 14 and 42 weeks, two-dimensional (2D) real-time and M-mode echocardiography were used to measure the diameters of the aortic root and the pulmonary artery in utero. The goals were to establish norms for the diameters of these structures as a function of both gestational age and biparietal diameter, to compare measurements obtained in systole and diastole, and to compare 2D and M-mode measurements. A high correlation was found between measurements made during systole and diastole (r = .994 for aorta, r = .996 for pulmonary artery) and between 2D and M-mode measurements for each vessel (r = .992 for aorta, r = .973 for pulmonary artery). The differences between systolic and diastolic measurements and between M-mode and 2D measurements were small (2.2-4.6%) for both the aorta and the pulmonary artery. The norms established here provide an objective standard for comparison when a cardiac anomaly involving a fetal aorta or pulmonary artery of abnormal size is suspected. The results indicate that a sonographic facility need not have M-mode equipment to obtain technically adequate measurements.

Fat-density oral contrast agent for abdominal CT

To overcome the problem of inadequate mixing of gastrointestinal (GI) tract contents with conventional high-density oral contrast agents in abdominal computed tomography (CT), a flavored 12.5% corn oil emulsion (COE) was tested as an oral contrast agent in 62 patients. The results were compared with those obtained from 105 patients who received high-density oral contrast agents. A simple patient preparation regimen for the COE was developed, which appears to be reasonably well tolerated by the patients and yields diagnostic studies comparable to those obtained with conventional agents. Use of the COE resulted in consistent discrimination of the GI tract and depiction of the GI wall. Preliminary data suggest that it may be particularly useful for CT evaluation of the stomach, duodenum, and pancreas; in patients suspected of having solid tumors; and in thin people.