Agricultural pesticide use and adenocarcinomas of the stomach and oesophagus.

AIMS: To evaluate the risk of the stomach and oesophageal adenocarcinomas associated with farming and agricultural pesticide use. METHODS: Population based case-control study in eastern Nebraska. Telephone interviews were conducted with men and women diagnosed with adenocarcinoma of the stomach (n = 170) or oesophagus (n = 137) between 1988 and 1993, and controls (n = 502) randomly selected from the same geographical area. Unconditional logistic regression was used to calculate adjusted odds ratios (ORs) for farming and for use of individual and chemical classes of insecticides and herbicides, including pesticides classified as nitrosatable (able to form N-nitroso compounds on reaction with nitrite). Non-farmers were used as the reference category for all analyses. RESULTS: Ever living or working on a farm, duration of farming, and size of the farm were not associated with stomach or oesophageal adenocarcinomas. There was no association for either cancer with ever-use of insecticides (stomach OR 0.9, 95% CI 0.6 to 1.4; oesophagus OR 0.7, 95% CI 0.4 to 1.1) or herbicides (stomach OR 0.9, 95% CI 0.5 to 1.4; oesophagus OR 0.7, 95% CI 0.4 to 1.2). Likewise, individual pesticides, including individual nitrosatable pesticides, were not significantly associated with risk. CONCLUSIONS: No significant associations were found between specific agricultural pesticide exposures and the risk of stomach or oesophageal adenocarcinomas among Nebraska farmers.

Distinctive gene expression profiles associated with Hepatitis B virus x protein.

Hepatitis B virus (HBV) is a major risk factor for the development of hepatocellular carcinoma (HCC). HBV encodes the potentially oncogenic HBx protein, which mainly functions as a transcriptional co-activator involving in multiple gene deregulations. However, mechanisms underlying HBx-mediated oncogenicity remain unclear. To determine the role(s) of HBx in the early genesis of HCC, we utilized the NCI Oncochip microarray that contains 2208 human cDNA clones to examine the gene expression profiles in either freshly isolated normal primary adult human hepatocytes (Hhep) or an HCC cell line (SK-Hep-1) ecotopically expressing HBx via an adenoviral system. The gene expression profiles also were determined in liver samples from HBV-infected chronic active hepatitis patients when compared with normal liver samples. The microarray results were validated through Northern blot analysis of the expression of selected genes. Using reciprocally labeling hybridizations, scatterplot analysis of gene expression ratios in human primary hepatocytes expressing HBx demonstrates that microarrays are highly reproducible. The comparison of gene expression profiles between HBx-expressing primary hepatocytes and HBV-infected liver samples shows a consistent alteration of many cellular genes including a subset of oncogenes (such as c-myc and c-myb) and tumor suppressor genes (such as APC, p53, WAF1 and WT1). Furthermore, clustering algorithm analysis showed distinctive gene expression profiles in Hhep and SK-Hep-1 cells. Our findings are consistent with the hypothesis that the deregulation of cellular genes by oncogenic HBx may be an early event that favors hepatocyte proliferation during liver carcinogenesis.

Laboratory automation: trajectory, technology, and tactics.

Laboratory automation is in its infancy, following a path parallel to the development of laboratory information systems in the late 1970s and early 1980s. Changes on the horizon in healthcare and clinical laboratory service that affect the delivery of laboratory results include the increasing age of the population in North America, the implementation of the Balanced Budget Act (1997), and the creation of disease management companies. Major technology drivers include outcomes optimization and phenotypically targeted drugs. Constant cost pressures in the clinical laboratory have forced diagnostic manufacturers into less than optimal profitability states. Laboratory automation can be a tool for the improvement of laboratory services and may decrease costs. The key to improvement of laboratory services is implementation of the correct automation technology. The design of this technology should be driven by required functionality. Automation design issues should be centered on the understanding of the laboratory and its relationship to healthcare delivery and the business and operational processes in the clinical laboratory. Automation design philosophy has evolved from a hardware-based approach to a software-based approach. Process control software to support repeat testing, reflex testing, and transportation management, and overall computer-integrated manufacturing approaches to laboratory automation implementation are rapidly expanding areas. It is clear that hardware and software are functionally interdependent and that the interface between the laboratory automation system and the laboratory information system is a key component. The cost-effectiveness of automation solutions suggested by vendors, however, has been difficult to evaluate because the number of automation installations are few and the precision with which operational data have been collected to determine payback is suboptimal. The trend in automation has moved from total laboratory automation to a modular approach, from a hardware-driven system to process control, from a one-of-a-kind novelty toward a standardized product, and from an in vitro diagnostics novelty to a marketing tool. Multiple vendors are present in the marketplace, many of whom are in vitro diagnostics manufacturers providing an automation solution coupled with their instruments, whereas others are focused automation companies. Automation technology continues to advance, acceptance continues to climb, and payback and cost justification methods are developing.

Human parvovirus B19 infection in acute fulminant liver failure.

We previously reported detection of human parvovirus B19 DNA in livers from patients requiring transplantation for acute fulminant liver failure. In this study, we used immune adherence PCR (IA-PCR) to bind B19 virions in recipient native liver onto solid phase with specific monoclonal antibodies followed by PCR amplification of virion DNA. IA-PCR had sensitivity and specificity similar to conventional PCR. We examined liver tissue from 16 patients with non-A, non-B, non-C, non-E (NA-E) acute fulminant liver failure (AFLF) (6 of unknown etiology associated with aplastic anemia (AA), 4 of unknown etiology without AA; and 6 patients with AFLF of known etiology). IA-PCR detected B19 virions in 5 of 6 (83%) of livers from patients with idiopathic NA-E AFLF associated with AA and in 2 of 3 (75%) without AA, compared to 1 of 6 (17%) of livers from patients with AFLF of known etiology and to 6 of 34 (18%) of 34 control patients with chronic or neoplastic liver disease. Viral mRNA encoding the structural protein was detected in the liver tissue from three B19 IA-PCR positive patients with AFLF. Detection of B19 virions and mRNA for capsid proteins provided strong evidence for B19 infection during the course of NA-E AFLF and argues for involvement of B19 virus in liver injury.

The effect of ursodeoxycholic acid on the florid duct lesion of primary biliary cirrhosis.

The frequency with which florid duct lesions are seen in needle-biopsy specimens of the liver was assessed in patients with primary biliary cirrhosis (PBC) enrolled in a 2-year randomized, double-blind, placebo-controlled trial of ursodeoxycholic acid (UDCA) versus placebo. Paired biopsy specimens obtained at entry and after 2 years on medication were reviewed blindly and mostly simultaneously by a panel of 5 hepatopathologists who, earlier, had characterized the florid duct lesion, which has been well described in the pathology literature. Florid duct lesions at entry were identified in approximately 36%. Patients with earlier disease showed florid duct lesions much more frequently than those with more advanced disease. The prevalence of florid duct lesions in 60 patients receiving placebo medication fell from 38.3% to 21.7%, P =. 025, over the period of 2 years. The prevalence of florid duct lesions also decreased in the 55 patients receiving UDCA, from 32.7% to 18.2%, P =.046. The prevalences of these lesions in the placebo and UDCA patients at entry and at 2 years were not significantly different from each other. The findings suggest that UDCA does not prevent ongoing bile duct destruction in patients with PBC. Instead, they support the impression that UDCA exerts its beneficial effects by protecting against the consequences of bile duct destruction.

Dietary lignin, and insoluble fiber, enhance uterine cancer but did not influence mammary cancer induced by N-methyl-N-nitrosourea in rats.

Previous investigations suggested potential breast cancer-preventive properties of dietary fiber from cabbage. The purpose of the present investigation was to determine whether lignin, a component of cabbage fiber, would protect against mammary carcinogenesis by N-methyl-N-nitrosourea (MNU) in Sprague-Dawley rats. A six-week study was conducted using diets containing 0.5-5% dietary wood lignin (a readily available, purified source). These diets were well tolerated by the rats, and a carcinogenesis study using 5 mg MNU/100 g body wt i.v. at 50 days of age was conducted, with the 2.5% lignin diet fed from 6 through 8 weeks of age followed by 5% lignin diet until 20 weeks after MNU. Dietary lignin and MNU treatment increased food consumption (p < 0.05), and body weight was slightly reduced at 10 and 20 weeks after MNU in the MNU-5% lignin diet group (p < 0.05). Serum estradiol was not altered by dietary lignin or MNU treatment, but uterine weights were highest in the MNU-control diet group 4 and 12 weeks after MNU. Expression of creatine kinase B, and estrogen-responsive gene, was lower in eh uteri of the MNU-lignin diet group than in other groups at 20 weeks. Mammary carcinogenesis was not altered by dietary lignin. However, uterine endometrial adenocarcinoma was observed only in the MNU-lignin diet group (4 carcinomas/40 effective rats) (p < 0.05).

Recent trends in clinical laboratory automation.

A convergence of concepts has allowed clinical laboratory automation to proceed in a greater number of laboratories: developing automation control interfaces, direct track sampling, and adopting a universal interface. The laboratory automation system (LAS) must interface to the laboratory information system (LIS), which provides the information necessary for routing and scheduling and for future rules-based processing, an important component of the LAS. The automation system also must operate in a real-time or near real-time environment and use the single tube per carrier paradigm. LAS capabilities should span the clinical laboratory and run parallel to the LIS with respect to information flow. The laboratory automation software will control the automated technology and the transportation system that binds clinical laboratory instruments together. It must be able to both drive the hardware components and interface with patient information sources, and it should further the goals of the health-care delivery system by supporting outcomes optimization and utilization management of laboratory resources. The development of workcells based on disciplines such as chemistry or hematology is having and will continue to have a significant effect on the acceptance of clinical laboratory automation technologies.

A pilot study of soluble adhesion molecules as surrogate markers for acute liver allograft rejection.

BACKGROUND: Tissue endothelial adhesion molecule expression is increased during acute liver allograft rejection. Soluble forms exist, but their correlation to rejection and their clinical value have not been determined. METHODS: We studied endothelial adhesion molecule tissue expression and soluble levels in blood and bile and correlated these to the clinical course of 11 adult patients followed for 30 consecutive days after liver transplantation. RESULTS: Three biopsies showing acute rejection demonstrated increased intercellular adhesion molecule (ICAM)-1 but not endothelial leukocyte adhesion molecule-1 expression on hepatic endothelial cells during rejection. Vascular cell adhesion molecule (VCAM)-1 staining was focally increased in two of three specimens. Levels of soluble ICAM-1 or soluble VCAM-1 by ELISA did not distinguish acute rejection from nonrejection conditions. CONCLUSION: We confirmed that endothelial ICAM-1 expression is more intense in rejecting allografts and is more sensitive than changes in VCAM-1 or endothelial leukocyte adhesion molecule-1. However, soluble adhesion molecule determination was not useful in the accurate detection of acute rejection.

Correlation of mucosal disaccharidase activities with histology in evaluation of rejection following intestinal transplantation.

Following intestinal transplantation, we have found that recovery from severe rejection may be difficult to identify. In this study we sought to ascertain whether concurrent determination of mucosal disaccharidase activities and histologic assessment improves the accuracy of diagnosis of rejection. Histologic changes were graded blindly using a standard set of diagnostic criteria, and these changes were compared over time to maltase, sucrase, lactase, and palatinase activities in four pediatric patients under treatment for severe rejection. The histologic criteria, which included magnitude of enterocyte loss, degree of granulation tissue, severity of villus atrophy, and frequency of apoptosis and cryptitis, were found to correlate with one another over time irrespective of outcome (r = 0.72 to r = 0.85). Enzyme activities were also correlated with each other over time (r = 0.64 to r = 0.80). However, the correlation between histologic diagnosis and enzyme activity was weaker (r = -0.48 to r = -0.57). Furthermore, neither histologic nor enzyme evaluation early in the course of rejection predicted ultimate clinical outcome. The results of this investigation show that determination of mucosal disaccharidase activity provides no additional useful information concerning efficacy of anti-rejection therapy as compared to histologic analysis alone.

Clinical denouement and mutation analysis of patients with cystic fibrosis undergoing liver transplantation for biliary cirrhosis.

OBJECTIVE: To describe the clinical characteristics of patients with cystic fibrosis considered for liver transplantation and the clinical outcome after transplantation. METHODS: Patient charts were reviewed. Mutation analysis was performed on blood or liver tissue samples with a panel of 17 mutations. RESULTS: Eight patients (five girls) with cystic fibrosis have undergone orthotopic liver transplantation for biliary cirrhosis. Mean age at transplantation was 12.0 years +/- 7.7 years (range, 9 months to 23 years). Preoperatively, seven patients had mild to moderate pulmonary dysfunction and one moderate to severe pulmonary dysfunction. All patients required pancreatic enzyme replacement, and four patients required insulin for diabetes mellitus. The 1-year survival rate was 75%, with no deaths related to septic events. Mean time of follow-up the six operative survivors was 4.1 years +/- 1.9 years. Pulmonary function testing, in those serially tested, showed that forced expiratory volume in 1 second was maintained or improved and that forced vital capacity improved after transplantation. Mutation analysis showed the following genotypes: four patients, delta F508/delta F508; one patient, delta F508/N1303K; and three patients, delta F508/unknown. CONCLUSIONS: Despite the high risk of transplantation, these encouraging results indicate that liver transplantation should be considered for patients with cystic fibrosis and complications of end-stage liver disease. We could not demonstrate an unusual pattern of CF gene mutations in these patients with severe liver disease. It appeared that immunosuppressive agents did not have a deleterious effect on pulmonary function.

Parvovirus B19 as a possible causative agent of fulminant liver failure and associated aplastic anemia.

We recently observed that more than one third of pediatric patients who presented with non-A, non-B fulminant liver failure (FLF) also developed aplastic anemia (AA) either before or shortly after liver transplantation. Factors involved in the suppression of bone marrow could be the same as those causing hepatic failure. We considered parvovirus B19 a candidate etiologic agent because of the known tropism of B19 for erythroid precursors. Archived liver and serum from six patients undergoing liver transplantation for non-A, non-B, non-C FLF with associated AA were analyzed for the presence of B19 DNA and anti-B19 serology. An age- and gender-matched control group (N = 44) was analyzed in parallel. B19 DNA studies and anti-B19 serology were performed in a blinded fashion. B19 serologies were performed by antibody capture enzyme-linked immunosorbent assay (ELISA). B19 DNA was detected after polymerase chain reaction (PCR) amplification of target B19 DNA sequences in liver and serum. Liver tissue showed evidence of B19 DNA in four of six (66%) patients with FLF and associated AA. Two of 4 patients with cryptogenic FLF but without AA had B19 DNA detected in the liver tissue. Of the 34 remaining controls, only 5 (15%) showed evidence of B19 DNA in liver tissue (66% vs. 15%, P = .016). B19 DNA was not detected in any of the test or control sera. This study provides evidence to support the role of parvovirus B19 in the development of FLF and associated AA.

Reliability and predictive value of the National Institute of Diabetes and Digestive and Kidney Diseases Liver Transplantation Database nomenclature and grading system for cellular rejection of liver allografts.

Pathologists participating in the National Institute of Diabetes and Digestive and Kidney Diseases Liver Transplant Database (LTD) created a histopathological grading system for acute liver allograft rejection, and tested it first for inter- and intra-rater reliability among a group of five pathologists experienced in liver and transplantation pathology. Specimens from post-transplantation biopsies from 48 patients with rejection, hepatitis, or other diagnosis(es) were reviewed. There was moderate to good (kappa = 0.40 to 0.55) inter-rater and good (kappa = 0.55 to 0.58) intrarater agreement for the diagnosis and exact grading of mild, moderate, or severe acute rejection, which improved when a short clinical history was provided. Thus, the scheme was reproducible, and few of the disagreements among the pathologists would have affected treatment decisions. Secondly, the ability of the grading system to predict an unfavorable short- or long-term outcome from the initial histopathological diagnosis of cellular rejection was tested on groups of 168 and 133 patients, respectively, from the three LTD clinical centers, who were followed up for at least 6 months after the first onset of rejection. This analysis showed that a higher histopathological grade of acute rejection on first biopsy diagnosis was significantly associated (P < or = .006) with both an unfavorable short-term outcome, defined by failure of the episode to resolve within 21 days or the need for aggressive immunosuppressive treatment, and a long-term outcome defined by death or retransplantation from rejection within 6 months of onset. Lastly, an analysis was performed to determine whether subjective rejection grading by the pathologist or certain "objective" histopathological features identified by logistic regression modeling were more accurate in predicting an unfavorable outcome.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical laboratory automation: concepts and designs.

Compared with other industries, automation in the healthcare arena has been slow to evolve. Changes in reimbursement for services provided are forcing hospitals and other healthcare providers to look for more cost effective mechanisms to provide all forms of health related services. Clinical laboratory services are essential to the support of hospital operations and most clinic operations. The current paradigm for clinical laboratory operations is based upon a mix of both batch and random access testing and is highly dependent upon clinical laboratory personnel. Changes in the paradigm for clinical laboratory operations may result in a significant cost savings when fully implemented while maintaining a high level of quality and service for the patients. Several different laboratory organization structures are discussed. The Nebraska automation project is described including the development of a modular conveyor system, the use of automated guided vehicles, software, and network architectures. Future directions for the development of clinical laboratory operations including the creation of a "docking device" to link automation systems to instruments is proposed.

Aplastic anemia after liver transplantation for fulminant liver failure.

We determined the incidence and outcome of aplastic anemia among 56 patients who underwent liver transplantation for fulminant liver failure at the University of Nebraska Medical Center between July 1985 and December 1993. Aplastic anemia developed in 6 of 18 (33%) children and 1 of 19 (5%) adults who had fulminant non-A, non-B hepatitis; no cases of aplastic anemia occurred among patients with other causes of fulminant liver failure. None of these patients had evidence of a preexisting hematological disorder or infection with hepatitis C virus (as determined with a second-generation ELISA). Aplastic anemia was diagnosed at a median of 4 wk after the onset of hepatitis, with five cases seen before transplantation. Six patients received antithymocyte globulin to promote remission of aplastic anemia. Three children died (fungal infection in two, intracranial hemorrhage in one)--one at 43, one at 108 and one at 119 days after transplantation--without remission of aplastic anemia. Among the four surviving patients, with median follow-up of 25 mo, complete and partial remission of aplastic anemia have occurred in three and one, respectively. Liver allograft function is stable in all surviving patients. The data demonstrate that aplastic anemia is a common complication among children who undergo liver transplantation for fulminant non-A, non-B hepatitis. It is associated with a high rate of mortality, although most survivors appear to have full hematological recovery.

Intrahepatic arteriopathy associated with primary nonfunction of liver allografts.

In this report we describe two cases of liver allograft primary non-function in which the donor organs were obtained from patients with a long-standing history of hypertension and placed in normotensive 2 recipients. Examination of these failed grafts showed marked luminal narrowing of the medium and large intrahepatic arteries along with extensive hepatocellular necrosis. No evidence of cellular allograft rejection was present. Preoperative frozen section evaluation of the donor liver failed to detect any pathological changes in the donor organs. Morphometric studies showed a statistically significant luminal narrowing of the medium arteries in these patients compared with controls with graft failure because of other causes (P < .0001). To our knowledge there are no previous reports describing this finding in the literature. We hypothesize that the arterial narrowing in these livers resulted in compromised blood flow to the organ after transplantation into a normotensive patient. Further studies are necessary to determine the frequency of these changes in the hypertensive population. Such studies may lead to the development of criteria that will identify potential donors who are likely to have such changes before organ procurement.

Epstein-Barr virus hepatitis after liver transplantation.

OBJECTIVES: The purpose of this study was to review our experience with Epstein-Barr virus (EBV) hepatitis after liver transplantation. METHODS: During a 68-month period, we performed 668 liver transplants and 585 patients. We identified 11 patients (2 percent), including 5 adults and 6 children with EBV hepatitis after liver transplantation. The diagnosis of EBV hepatitis was established by evaluating allograft biopsies. The histology was confirmed by the use of polymerase chain reaction technology. RESULTS: The average time of diagnosis after liver transplantation was 45 days. Eight of eleven cases occurred within the first six months after transplantation. After the diagnosis of EBV hepatitis, treatment consisted of a decrease in immunosuppression plus antiviral therapy and intravenous immunoglobulin. The one-year actuarial survival for patients with EBV hepatitis, was 73 percent (8 of 11). Two patients died of progressive multi-organ EBV involvement. To determine the risk of developing EBV hepatitis, we reviewed our experience with the administration of antilymphocyte preparations in 585 patients. The patients found to have a significantly greater risk of developing EBV hepatitis included those receiving more than one course of antilymphocyte therapy or greater than a total dose of 70 milligrams of OKT3 in a single course. CONCLUSIONS: EBV hepatitis after liver transplantation is an infrequent event, which may be treated successfully. The occurrence of EBV hepatitis appears closely linked to the use of antilymphocyte preparations.