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Biomedical subjects

R S Markin

Publications and source records attributed to R S Markin.

At least 55 records · Page 3Linked to original sources
PubMed1992

Hepatic retransplantation: University of Nebraska Medical Center experience.

The lack of an artificial liver makes liver retransplantation a unique, life-saving procedure when all the other alternatives to save a failed graft have been exhausted. On the other hand, the shortage of donors in line with the increasing number of end-stage liver disease patients who are waiting in long recipient lists represents a dilemma and raises the question of most appropriate recipient selection. In this report, we retrospectively analyzed the results of 350 primary, 48 secondary, and 5 tertiary hepatic transplants performed between July 1985 and January 1990 at University of Nebraska Medical Center. The same immunosuppression protocol was used in each case and the maintenance immunosuppressive therapy consisted of a cyclosporine (CyA) and steroids. The overall survival rate of 80.5% at 1 year which was achieved in the primary grafting group was significantly better than the secondary grafting group (63.0%, p less than 0.05). However, this difference was not significant in pediatric patients and their rates were 73.8% and 71.6% in primary and secondary grafting groups, respectively. When the retransplanted patients were considered as deaths unless secondary grafting was performed, the overall patient survival rate of 69.7% in primary grafting group at 1 yr increased to 77.8% in the retransplanted group and this difference was significant (p less than 0.05). Blood loss and operating time were found to be lower in the retransplanted group. Furthermore, the decrease of the operating time in the retransplanted pediatric patients reached statistical significance (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Liver transplantation at the University of Nebraska Medical Center from 1985 to 1992.

Based on our 7 and one-half-year experience with liver transplantation at the University of Nebraska Medical Center: 1. Success and growth of the program has been, in part, the result of close interaction and support of the various specialists involved. 2. We have demonstrated that outstanding patient and graft survival rates can be obtained with cyclosporine/prednisone immunosuppression. 3. Few, if any, technical contraindications exist to liver transplantation. 4. Surgical advances have allowed allografts to be salvaged which would otherwise require replacement. 5. Routine donor-liver biopsy prior to implantation has reduced the rate of primary nonfunction. 6. New strategies to improve survival for patients with hepatitis-B-related liver disease and hepatic malignancies undergoing liver transplantation need to be developed. 7. The management of patients with fulminant hepatic failure is evolving and now includes innovative approaches such as the use of ECLS and auxiliary transplants.

Academic Medical Centers↗
PubMed1992

Laboratory automation systems. An introduction to concepts and terminology.

The concept of laboratory automation has existed for years; such automation has been used primarily in nonclinical and industrial settings. The next step is to implement automation systems in the clinical laboratory. A laboratory automation system consists of robots, conveyor systems, machine vision, and computer hardware and software. Specimen movement and result reporting are based on the identification of specimens using bar coded specimens and bar coded specimen carriers. The implementation of a laboratory automation system is dependent on the presence of a laboratory information system. An interface between the laboratory information system and the laboratory automation system provides the information required to move the specimen through the laboratory. The reporting of results is dependent on the laboratory information system or manual input, depending on the type of work cell in which the results are produced. The greatest hurdle to overcome in developing and implementing a laboratory automation system is the integration of systems, including commercial laboratory instrumentation and user-defined work cells. The barriers to implementation primarily are proprietary in nature: instrument software and instrument hardware. When the instrument manufacturers realize the necessity for development of electronic and physical integration, the proliferation of laboratory automation systems will occur. Several opportunities exist for the reduction in laboratory expenses and the development of new positions, such as "robotechnologist," a staff member who would function in a manner similar to the current laboratory information systems manager. This article describes the author's concepts of laboratory automation.

Automation↗
PubMed1992

The impact of transplantation on the clinical laboratory. Experience at the University of Nebraska with bone marrow and liver transplantation.

The number of both bone marrow and solid organ transplantation programs has increased significantly during the past several years. The implementation of these programs and their growth have had a significant impact on the clinical laboratories that are involved in the support of these programs. Between 1983 and 1985, two major organ transplantation programs were implemented at the University of Nebraska Medical Center, Omaha. The clinical laboratories at the University of Nebraska Medical Center have seen a 217% increase in procedure volume and a 165% increase in full-time equivalents during an 8-year period from 1983 to 1991 as a result of these programs. The laboratory procedures that are performed on patients who are undergoing transplantation currently generate approximately $9 million in charges per year. In the present article, I discuss the effect of bone marrow and liver transplantation programs on the entire laboratory and individual laboratory sections.

Academic Medical Centers↗
PubMed1991

Neonatal hepatitis and extrahepatic biliary atresia associated with cytomegalovirus infection in twins.

Prenatally acquired cytomegalovirus infection in twins was temporally associated with a discordant development of neonatal hepatitis and extrahepatic biliary atresia. This case presents evidence suggesting an association between perinatal cytomegalovirus infection and selected extrahepatic biliary atresia and neonatal hepatitis. Congenital cytomegalovirus infections and cytomegalovirus hepatitis are also discussed.

Biliary Atresia↗
PubMed1991

Clinical spectrum of fungal infections after orthotopic liver transplantation.

During a 50-month period, we identified 91 episodes of fungal infection in 72 liver transplant recipients (23.8%). Candida species accounted for 83.5% of cases. Clinical patterns of fungal infections included disseminated infection (19), peritonitis (17), pneumonitis (15), multiple sites of colonization (13), fungemia (11), and other sites (16). The diagnosis of fungal infection was usually made in the first 2 months (84.7% of cases), at a mean time of 16 days after transplantation. Risk factors for fungal infections included retransplantation, Risk score, intraoperative transfusion requirement, urgent status, Roux limb biliary reconstruction (in adults), steroid dose, bacterial infections and antibiotic therapy, and vascular complications. Fungal infections were successfully treated with amphotericin B in 63 cases (74.1%) but were associated with diminished patient survival (50% vs 83.5%). Fungal infection is a frequent source of early morbidity and can be related to well-defined risk factors, suggesting the need for effective prophylaxis.

Adolescent↗
PubMed1991

Syndrome of multiple bowel perforations in liver transplant recipients.

In an analysis of surgical complications following 500 consecutive orthotopic liver transplants, we identified 12 patients who developed the syndrome of multiple bowel perforations that was not due to iatrogenic injury. All cases occurred in small children (mean weight: 9.0 kg), who represented 7% of the pediatric population. Each patient had a minimum of three perforations. The typical intraoperative findings were pin-point perforations in areas of normal-appearing bowel. With only one possible exception (a patient with cytomegalovirus enteritis), no specific etiology could be determined. Management was based on multiple exploratory laparotomies and individualized operative procedures. All patients are currently alive (mean follow-up: 34.9 months). The pathogenesis of the syndrome of multiple bowel perforations remains unclear but is possibly multifactorial or related to high doses of steroids. Aggressive surgical management with semiopen treatment of peritonitis and frequent explorations has afforded excellent results.

Child, Preschool↗
PubMed1991

gamma-Aminobutyric acid localization and function as modulator of cholinergic neurotransmission in rat antral mucosal/submucosal fragments.

gamma-Aminobutyric acid, a neurotransmitter in the central nervous system, has been shown to be present in and synthesized and secreted by rodent and feline myenteric plexus neurons. The aims of the present studies were to measure gamma-aminobutyric acid concentrations and synthesis and to establish cellular localization and uptake of gamma-aminobutyric acid by immunocytochemistry and autoradiography, respectively, within mucosal and submucosal tissues of the rat antrum. Direct demonstration of [3H]gamma-aminobutyric acid release and the effects of exogenous gamma-aminobutyric acid and muscimol, a GABA alpha agonist, on [3H]acetylcholine release from antral mucosal/submucosal fragments were examined in perifusion experiments. gamma-Aminobutyric acid content and synthesis, as reflected by glutamic acid decarboxylase activity, were present within antral mucosa at levels two to three times that of the body and muscular layers of both the gastric body and antrum. gamma-Aminobutyric acid was identified immunocytochemically, principally in mucosal epithelial cells of the antrum. Exogenous gamma-aminobutyric acid and muscimol were capable of stimulating acetylcholine release through a GABA alpha receptor-mediated mechanism that was abolished by tetrodotoxin. These results indicate that gamma-aminobutyric acid is present in and taken up by epithelial cells of the gastric antrum and that gamma-aminobutyric acid is capable of being synthesized by antral mucosal/submucosal tissues. Furthermore, these studies suggest that a peripheral gamma-aminobutyric acid mechanism that may modulate cholinergic neurotransmission and endocrine cell function exists within the antrum.

Acetylcholine↗
PubMed1991

Endoscopy in the diagnosis of gastrointestinal Mycobacterium avium-intracellulare infection.

Two cases of mycobacterium avium-intracellulare (MAI) infection in association with acquired immunodeficiency syndrome (AIDS) are presented to highlight the distinctive upper gastrointestinal endoscopic appearances: 2 X 4 mm diameter, white nodules with intervening erythema and hemorrhagic erosions covered the mucosa of the second part of the duodenum. Histological evaluation of these nodules revealed diffuse expansion of the lamina propria by macrophages that contained numerous intracellular and extracellular acid-fast organisms. We conclude that endoscopy with endoscopic biopsy may represent the most rapid and sensitive diagnostic tool available in this disease.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Successful prophylaxis of cytomegalovirus disease after primary CMV exposure in liver transplant recipients.

UNLABELLED: During a 38-month period, we studied 320 liver transplants in 283 recipients (202 adults, 81 children). CMV disease was documented in 85 patients (30.0%) The major risk factor for CMV disease was primary CMV exposure (transplanting a seropositive allograft into a seronegative recipient). A total of 42 patients (14.8%) had primary CMV exposure. Twenty-one patients were historical controls, while the next 21 received prophylaxis for CMV infection in a nonrandomized trial of consecutive study groups. The regimen of prophylaxis consisted of intravenous immune globulin (IgG; 0.5 g/kg) at weekly intervals for 6 weeks and acyclovir for 3 months. CMV prophylaxis resulted in a dramatic reduction in the incidence of CMV disease (71.4% vs. 23.8%, (P less than 0.01). All cases of CMV were treated with intravenous ganciclovir (5 mg/kg b.i.d. for 14 days), with 5 patients in the control group developing recurrent CMV disease (33.3% relapse). In the 16 patients receiving prophylaxis who did not develop CMV disease, all developed positive CMV-IgG titers with the passive administration of IgG. However, none developed any evidence of CMV infection or viral shedding as assessed by IgM titers and surveillance viral cultures. Four deaths occurred (all control patients), but none were related to CMV disease. Overall patient and graft survivals after primary CMV exposure were 90.5% and 82.2%, respectively, after a mean follow-up of 14 months. CONCLUSION: Primary CMV exposure is a major risk factor for CMV disease in liver transplant recipients. Intravenous IgG plus acyclovir is safe and effective in preventing CMV infection and disease in this setting. Because of the scarcity of donor organs, we do not advocate protective matching to avoid primary CMV exposure but rather recommend prophylaxis to prevent CMV disease in this high-risk group.

Acyclovir↗