BACKGROUND: Isolated organ perfusion with hyperthermia and melphalan with or without tumor necrosis factor-alpha has been effectively used to treat regionally confined, unresectable malignancies of both the limb and liver. Many patients, however, will eventually relapse at distant sites. We used reverse transcription-polymerase chain reaction (RT-PCR) to determine whether significant tumor microembolization occurs in patients undergoing isolated limb perfusion (ILP), isolated hepatic perfusion (IHP), or hepatic resection. METHODS: Primers specific for the human tyrosinase gene or carcinoembryonic antigen gene were designed for RT-PCR to screen melanoma or colon adenocarcinoma, respectively. RNA from human melanoma lines (Pmel and 1286) and human colon adenocarcinoma lines (H508 and HT29) were used to generate positive control cDNA. Normal human blood was inoculated with tumor cells at concentrations that ranged from 10(-2) to 10(5) tumor cells/ml of blood to define the sensitivity. Systemic and perfusate blood samples were drawn from 15 patients (8 patients underwent IHP, 5 patients underwent ILP, and 2 patients underwent resection) before the start of the operation, immediately before and during the perfusion, and postoperatively. Mononuclear cell fractions were separated from the blood samples and RNA was extracted for the RT-PCR assay. Standard primers for human beta-actin were used to confirm that cDNA was generated after the RT reaction. RESULTS: RT-PCR assay sensitivity was determined to be 10 tumor cells/ml of whole blood. Of the 8 IHP patients, 6 had colon metastases and 2 had ocular melanoma metastases to the liver. All 5 ILP patients had in transit melanoma of the extremity. Two patients with colon metastases to the liver were found to have resectable disease. There were no detectable circulating tumor cells in the systemic circulation either preoperatively or postoperatively in all 15 patients that were screened. CONCLUSIONS: RT-PCR is a highly sensitive method of detecting tumor cells in perfusate or blood. Manipulation of the limb or liver followed by resection or isolated hyperthermic perfusion does not cause detectable release of circulating tumor cells. The late development of distant metastases observed in many of these patients does not correlate with the ability to measure circulating tumor cells during regional therapy.

Adenocarcinoma↗

PubMedDate not supplied

Required steps for the validation of a Laboratory Information Management System.

The task of managing laboratory data is not a new one. Over the past two decades, the use of Laboratory Information Management Systems (LIMS) has revolutionized how laboratories manage their data. A LIMS is more than software; it has become the workhorse of the laboratory, encompassing laboratory work-flow combined with user input, data collection, instrument integration, data analysis, user notification, and delivery of information and reporting. Types of organizations that utilize LIMS vary greatly from research laboratories to manufacturing laboratories to environmental testing laboratories. Commercially-available LIMS have been around since the 1980s. In addition, many laboratories have designed, implemented, and maintained in-house LIMS. The heart of any LIMS is the software. Like other laboratory systems, the LIMS software is subject to quality control and quality assurance checks. In regulatory environments this associated QA/QC is referred to as "system validation." The primary purpose of system validation is to ensure that the software is performing in a manner for which it was designed. For example, the system acceptance criteria should be established and tested against quantifiable tasks to determine if the desired outcome has been achieved. LIMS features, such as autoreporting, reproducibility, throughput, and accuracy must be quantifiable and verifiable. System validation ensures that the entire system has been properly tested, incorporates required controls, and maintains and will continue to maintain data integrity. Laboratories must establish protocols and standards for the validation process and associated documentation. Although vendors of commercial LIMS perform initial internal system validations, the system must be revalidated whenever the end user, vendor or third party adds modifications or customizations to the LIMS. Currently, detailed guidance regarding system validation of LIMS is not available to the user. The issue is addressed in Good Automated Laboratory Practices (GALP) and National Environmental Laboratory Accreditation Conference (NELAC) documents which indicate specific requirements or recommendations for operational checks and periodic testing; however, it is up to the laboratory to determine suitable methods to accomplish these tasks. Proper validation of a LIMS will allow a laboratory to comply with regulations and also provide comprehensive documentation on the system that is necessary to troubleshoot future problems.

Clinical Laboratory Information Systems↗

PubMedDate not supplied

Nurses oppose American Medical Association's proposal: AMA's proposal.

Explore the source record for details and available documents.

American Medical Association↗