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Biomedical subjects

S B Moore

Publications and source records attributed to S B Moore.

At least 19 recordsLinked to original sources

Ischemic-type biliary complications after orthotopic liver transplantation.

Nonanastomotic biliary strictures that involve only the biliary tree of the graft occur after orthotopic liver transplantation in patients with hepatic artery thrombosis, chronic ductopenic rejection and ABO blood group incompatibility. This complication may also occur in the absence of these known risk factors. The major focus of our study was to evaluate the risk factors for nonanastomotic biliary stricturing of unknown cause after orthotopic liver transplantation. Results demonstrate that the development of biliary strictures is strongly associated with the duration of cold ischemic storage of allografts in both Euro-Collins solution and University of Wisconsin solution. Results also demonstrate that strictures are not associated with the type of biliary reconstruction, the primary liver disease, cytomegalovirus infection, allograft rejection or the presence of a positive lymphocytotoxic crossmatch. More recently, we have markedly reduced the occurrence of nonanastomotic biliary stricturing by decreasing the ischemia time of our allografts. Thus nonanastomotic biliary strictures appear to be the result of the ischemia/reperfusion-induced tissue injury associated with the harvest and implantation of allografts.

Adenosine

Lack of association between cytomegalovirus infection, HLA matching and the vanishing bile duct syndrome after liver transplantation.

In this study we evaluated the association between cytomegalovirus infection alone or in relation to human leukocyte antigen matching and the development of vanishing bile duct syndrome, a form of chronic hepatic allograft rejection. A total of 81 consecutive liver transplant recipients were studied. Cytomegalovirus infection developed in 46 recipients (57%), and vanishing bile duct syndrome occurred in 9 recipients (11%). Cytomegalovirus infection developed in only five of the nine patients with vanishing bile duct syndrome. Univariate analysis of pretransplant recipient/donor cytomegalovirus serological tests and human leukocyte antigen typing showed they were not significant risk factors for the development of vanishing bile duct syndrome. Time-dependent analysis of cytomegalovirus infection after transplantation as a risk factor for vanishing bile duct syndrome, in a multivariate analysis with human leukocyte antigen match, showed no statistical significance. In our study, no association was found between cytomegalovirus infection alone or in relation to class I or II human leukocyte antigen match and the subsequent development of vanishing bile duct syndrome.

Acyclovir

Mayo Clinic experience with allogeneic and syngeneic bone marrow transplantation, 1982 through 1990.

Between April 1982 and July 1990, 101 patients underwent allogeneic or syngeneic bone marrow transplantation at the Mayo Clinic. This patient population consisted of 30 with acute nonlymphocytic leukemia, 25 with acute lymphoblastic leukemia, 29 with chronic granulocytic leukemia, and 17 with other diseases (aplastic anemia in 7, myelodysplastic syndrome in 5, and lymphoma in 5). The results achieved in our patients who underwent transplantation in first complete remission of both acute nonlymphocytic leukemia and acute lymphoblastic leukemia compare favorably with previously reported results. Only 1 of 15 patients (7%) with acute nonlymphocytic leukemia and 2 of 8 patients (25%) with acute lymphoblastic leukemia who underwent transplantation in first complete remission had a relapse. Thus, we recommend early bone marrow transplantation during initial complete remission for patients with either of these disorders who have adverse prognostic factors. In contrast, of 12 patients with either acute nonlymphocytic leukemia or acute lymphoblastic leukemia who underwent transplantation during relapse, 11 died within 6 months. Therefore, such patients should be offered new experimental treatments. Our patients with chronic granulocytic leukemia fared better when they underwent transplantation early during the course of their disease rather than during the accelerated or blast phase. Prospective studies are needed to determine the best approach in these patients.

Academic Medical Centers

Simplified enrollment for autologous transfusion: automatic referral of presurgical patients for assessment for autologous blood collections.

We implemented a pilot program at our institution for automatic referral of patients for presurgical assessment for preoperative and intraoperative collection of autologous blood. Although patients and clinicians support the use of autologous transfusion, often a request for collection of autologous blood is not initiated. During 11 months, 269 patients (82%) of three orthopedic surgeons entered the program, and 218 underwent operation and were dismissed from the hospital. A total of 940 units of autologous blood (675 preoperatively and 265 intraoperatively) was collected from these 218 patients, and 84% of the units were transfused. Throughout hospitalization, 86% of the patients received only autologous blood, whereas 14% received various proportions of homologous and autologous blood. In contrast, only 26% of a concomitant control group of 220 consecutive orthopedic surgical patients not participating in the automatic-referral program received only autologous blood. Thus, the automatic-referral program increased the percentage of elective orthopedic surgical patients who received only autologous blood from 26% to 86% (P less than 0.001). This study also showed that the same amount of blood was used for autologous transfusions as was routinely used for homologous transfusions in similar cases. The automatic-referral system was convenient for physicians and patients and offered the benefits of reduction of transfusion-associated risks and amelioration of patient anxieties.

Blood Transfusion, Autologous

Clinical and prognostic implications of HLA B8 in corticosteroid-treated severe autoimmune chronic active hepatitis.

To assess the clinical and prognostic implications of human leukocyte antigen B8 in corticosteroid-treated severe autoimmune chronic active hepatitis, 81 consecutive patients were tested for histocompatibility antigens on the A and B loci, treated with corticosteroids, and followed prospectively for 111 +/- 8 mo. The 47 patients with HLA-B8 were younger (38 +/- 2 yr vs. 48 +/- 2 yr; p less than 0.01), had higher serum levels of aspartate aminotransferase (658 +/- 60 U/L vs. 465 +/- 49 U/L; p = 0.02) and bilirubin (7 +/- 1 mg/dl vs. 2.8 +/- 0.4 mg/dl; p = 0.003), and more commonly had histologic features of bridging necrosis, multilobular necrosis, and cirrhosis (85% vs. 56%; p less than 0.01) at presentation than the 34 patients without HLA-B8. Remission (79% vs. 71%), relapse after drug withdrawal (76% vs. 71%), treatment failure (13% vs. 6%), progression to cirrhosis (46% vs. 32%), and death from liver failure (6% vs. 3%) occurred as frequently in patients with and without HLA-B8. Importantly, HLA-B8-negative patients with HLA-A1 relapsed less frequently than HLA-B8-positive patients with and without HLA-A1- and HLA-B8-negative counterparts without HLA-A1. It is concluded that HLA-B8-positive patients are younger and have more severe disease at presentation than HLA-B8-negative patients. The HLA-B8 phenotype does not influence the response to corticosteroid therapy. HLA-B8-negative patients with HLA-A1 relapse less frequently than other phenotypes.

Adult

Persistent centrilobular necroses in hepatic allografts.

A biopsy study of 60 allografts from 53 patients after orthotopic liver transplantation (OLT) revealed prominent centrilobular necrosis (CN) in 18% of the grafts that were suitable for analysis. The lesions often had a "punched-out" appearance, sometimes with unusual features such as giant cell formation. Persistent CN developed 4 weeks to 6 months after OLT, and persisted in two cases for 2 years and longer. In some instances, CN disappeared or healed by scarring. We found no association between CN and rejection arteritis or arteriopathy. Ductopenic (chronic) rejection subsequently occurred in six of eight livers with CN. Overall, patients with persistent CN had a worse prognosis than control patients. A comparison of cases with matched controls failed to reveal significant differences with respect to perioperative factors such as ischemia time, immunologic test results such as lymphocyte crossmatches, drug administration--in particular, of azathioprine, frequency of cellular (acute) rejection or infection episodes, or frequency of complications affecting major hepatic vessels or bile ducts. Morphologic evidence suggests that in some instances, rejection-induced endotheliitis/phlebitis of hepatic vein branches may lead to sinusoidal outflow blockage, sinusoidal dilatation, and dropout of hepatic cell plates. Although potentially reversible conditions such as ischemia or adverse drug reactions are among the possible causes of CN, severe rejection leading to ductopenia appears to be the most important underlying condition. Thus, presence of CN in repeated biopsy specimens from allografts should be considered a warning sign of irreversible rejection.

Adult

Posttransfusion purpura: the therapeutic value of PlA1-negative platelets.

A case of PlA1-associated posttransfusion purpura (PTP) is reported, in which a previously sensitized patient developed life-threatening thrombocytopenia, purpura, hematuria, and bronchial bleeding. The patient was transfused with PlA1-negative single-donor apheresis platelets (from four different donors) on four occasions. The first transfusion resulted in a 1-hour posttransfusion increment of 57 x 10(9) per L. The use of two additional PlA1-negative apheresis platelets provided support for a tracheostomy. Bronchial bleeding leading to respiratory arrest was controlled with a fourth transfusion. All PlA1-negative platelet transfusions resulted in transient increases in the patient's platelet count. This is the first reported case of repeated, transiently effective transfusion of PlA1-negative platelets demonstrated during the acute phase of thrombocytopenia.

Antigens, Human Platelet

Minimal-exposure transfusion and the committed donor.

Autologous blood (collected preoperatively or salvaged intraoperatively) is the safest blood available for transfusion, but its use is not always feasible. It may be possible to decrease a patient's exposure to homologous donors. Pediatric cardiac surgery patients frequently are unable to donate autologous blood preoperatively. Since 1984, attempts have been made to provide parental apheresis platelets and intraoperative blood salvage to such patients to decrease their donor exposure. Further decreases in donor exposure have been the object of a program of collecting from one committed donor all the blood a patient is anticipated to need. This article reviews the experience with 50 pediatric cardiac surgery patients on such a program, in whom the mean decrease in homologous-donor exposure was 57 percent (range, 12-93%). Thirteen of these patients received only homologous blood products from one committed donor, for a mean decrease in homologous-donor exposure of 80 percent (range, 50-93%). A comparison of 12 of these 13 recipients with a matched control group showed no significant difference in red cell transfusion practice but a significant difference in the number of homologous-donor exposures per m2 of body surface area (BSA) (mean donor exposures/m2 of BSA: patients = 1.5, controls = 10.5). The use of one committed donor and autologous blood can provide a minimal-exposure transfusion.

Adolescent

Roles of the neutrophil and other mediators in adult respiratory distress syndrome.

The adult respiratory distress syndrome (ARDS) and transfusion-related acute lung injury (TRALI) are characterized by diffuse, acute lung injury. Most likely, TRALI is a type of ARDS although it is associated with a much lower morbidity and mortality than found with classic ARDS. For years, the pathogenesis of ARDS has been explained by the complement hypothesis in which pulmonary neutrophilic sequestration and degranulation follow complement-mediated neutrophil chemotaxis. A definitive role for the neutrophil in diffuse, acute lung injury, however, has not been established. Although numerous chemoattractants for neutrophils are generated in the lungs and, through degranulation and formation of toxic oxygen free radicals, the neutrophil is fully capable of causing tissue injury, substantial evidence refutes the requirement for neutrophils in diffuse, acute lung injury. Other potential factors in the pathogenesis of ARDS include primary endothelial cell injury, alveolar macrophage activity, and hemostatic disorders.

Chemotaxis, Leukocyte

Morning admission for a same-day surgical procedure: resolution of a blood bank problem.

To minimize the risks associated with an elective surgical procedure on the day of admission without adequate time for blood bank serologic analysis, we implemented two administrative changes: (1) collection of blood samples from patients on the evening before operation and (2) a system for recommending a 3-hour delay of the operation in those cases without such a sample. During a 4-month period before implementation of these changes, 70 patients had serologic problems; morning blood samples had been obtained from 36 of these patients. For a comparable time after implementation of these changes, a serologic problem was encountered in 41 surgical cases, in 7 of which morning blood samples had been obtained. Similarly, the number of cases in which the operation was begun before resolution of a serologic problem decreased from 19 to 3. These decreases occurred despite a 13.4% increase in total morning-admission cases between the first and second study periods. Although no patient experienced adverse transfusion-related events during either study period, simple administrative changes that necessitated no increases in costs were instrumental in substantially decreasing the risks to patients.

Blood Banks

Delayed hemolysis resulting from anti-A1 after liver transplantation.

The authors report a case of a delayed hemolytic transfusion reaction in a type A2 recipient of a type O liver allograft. An anti-A1 antibody reactive at 37 degrees C in the indirect antiglobulin test was identified both in the patient's serum and in an eluate. Hemolysis secondary to the production of anti-A1 has been reported to be extremely rare. The English-language literature has six cases before 1979. During the 1980s, an additional seven cases were reported; six involved transplantation of a solid organ, and in each such case the donor was type O and the recipient was type A1 or A2. Recommendations regarding transfusion practice in such cases are made. An association among the transplantation of a type O organ to a type A recipient, the use of cyclosporine, and an apparent increase in the occurrence of clinically significant anti-A1 is suggested.

Autoantibodies