Douglas C. Stahl

Liquid chromatography/microspray mass spectrometry for bacterial investigations.

Cellular proteins (biomarkers) specific to any individual microorganism, determined by the direct mass spectral analysis of the corresponding intact cellular suspension, can be applied for the rapid and specific identification of the organisms present in unknown samples. The components of the bacterial suspensions, after a rapid separation over a C18 reversed-phase microcapillary column, were directly subjected to on-line electrospray ionization followed by analysis using an ion trap tandem mass spectrometer. This approach is equally effective for gram-positive as well as gram-negative bacteria but has a distinct advantage over our earlier reported method involving matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS). During electrospray ionitation mass spectrometry (ESI-MS), liquid samples can be directly analyzed and there is the potential for developing tandem mass spectral methods for more specific identification of the individual organisms present in crude bacterial mixtures. The total analysis time leading to unambiguous bacterial identification in samples was less than 10 minutes and the results were quite reproducible. Miniaturization of the instrumentation along with total automation of this simple process could have immense impact on field operations. Routine, rapid, cost-effective field monitoring of environmental samples, agricultural products, samples from food processing, industrial sites and health institutions for suspected bacterial contamination could be a reality in the near future. Potential utility in biological, medical, bioprocessing, pharmaceutical, and other industrial research is also enormous.

Mass spectral investigations on microorganisms

Bacterial cells undergo lysis readily, when suspended in mild aqueous acids, and release the cellular proteins along with other biomolecules. Molecular masses of the protein biomarkers released in-situ from individual intact bacterial cells could be directly measured by mass spectrometry. Limited sample clean up may be required at times, prior to mass spectral analysis, to remove any ionizable impurities such as salts, buffers and deergents. The marker proteins specific for individual genus, species and strains were determined by the comparison of the biomarkers measured for several closely related organisms. Even though there is a probability of over 4000 cellular proteins expressed in any single bacterial cell, only a small fraction of the projected marker proteins are identified consistently during the process. This could be due to the variation in the ionization properties of the proteins and the limited energy available to prompt their ionization. Variation in the sample processing and culture conditions had little effect in the marker proteins observed during the process. This experimental procedure enables the distinction of gram positive as well as gram negative cellular pathogens and their corresponding non-pathogenic counterparts. The identity of few bacterial cells present in unknown samples can be easily, rapidly and accurately established by adopting a procedure involving simple sample processing followed by direct mass spectral analysis and data processing. Thus, an uncomplicated approach has been developed to resolve a complex problem involving cellular pathogens. This method has enormous application potential in the rapid identification and subsequent prevention of any potential health hazard caused by the pathogenic bacteria, either under natural or induced conditions. There is a great potential for the total automation of the entire process in the future for simpler but more effective unattended operations in the laboratory as well as in the field.

GDSI: a Web-based decision support system to facilitate the efficient and effective use of clinical practice guidelines

Clinical practice guidelines (CPGs) are systematically developed healthcare recommendations designed to improve quality and control costs by reducing errors, minimizing practice variability, and promoting best practices. Although considerable effort and resources have been applied to CPG design, development, and deployment, the impact of CPGs on clinician behavior is inconsistent at best. The biomedical literature suggests that CPG efficacy could be improved using information systems that make CPGs and related patient-specific decision support functions available and easier to use at the point of care. This approach also depends upon the ability to integrate CPG information systems into the clinician workflow. Based on an analysis of the barriers to efficient and effective guideline use, researchers from City of Hope National Medical Centers Division of Information Sciences were motivated to develop a Web-based expert system to facilitate CPG utilization in a variety of clinical environments. The resulting Graphical Decision Support Interface (GDSI) employs a relational database-driven state machine architecture adapted from an instrument control system developed by one of the authors. The user interface was designed to facilitate clinician interaction with large, complex decision hierarchies. As users enter information about an individual patient, the system computes additional derived values and provides context-specific recommendations. It also documents when and why clinicians intentionally deviate from guideline recommendations to assist with organizational benchmarking and CPG modification efforts. This report describes the GDSI prototype and our experience with the translation of breast cancer treatment guidelines into algorithms with explicit states and decision points. It also describes a pilot study of the system at two Southern California cancer treatment facilities. Preliminary results suggest that the GDSI system is well received among clinicians and is capable of making a positive contribution toward CPG development and use. Lessons learned and directions for future research are also discussed.

Increasing Clinical Trial Awareness and Accrual Via the Web

The tremendous public and professional demand for online cancer information (Benjamin et al., 1996) is part of an emerging health care delivery paradigm in which information technology helps individuals access information about their medical conditions and potential treatment options (Widman & Tong, 1997). The Internet has had an impact on the evolving relationship between patients and physicians. There has been a growing movement advocating the view that patients are healthcare consumers with rights to information, interaction with health professionals, and participation in decision making (Sutherland et al., 1989). “Baby boomer” and post-baby boomer patient populations are found to be more autonomous, assertive, and demanding than patients of the past (Huber, 1993).

Evaluating the impact of Clinical Trials On-line on clinical trial awareness and accrual

Clinical trials are essential for understanding the effects of different cancer treatment approaches and the value of their interaction. A prerequisite for completion of a clinical trial is the accrual of an adequate number of patients. Although surveys of the general public have shown widespread support for the concept of clinical trials, it is widely reported that only 1-3% of the 1.2 million patients diagnosed with cancer in the United States each year are enrolled. Explaining clinical trials to patients and their families, remembering active trials to a particular malignancy, and paper based distribution of clinical trial information have been identified among several major obstacles to enrolment. Improved information distribution methods, heightened public awareness, and the dissemination of clinical trial synopses have been suggested as strategies to help overcome them. Based on an analysis of the barriers to clinical trial enrolment and the emergence of the Internet as part of a new paradigm in healthcare information delivery, City of Hope National Medical Center was motivated to develop a Web enabled database of oncology clinical trials information called Clinical Trials On-Line (CTOL). The article describes CTOL and the methods employed to assess its impact. A summary of the different types of interactions, inquiries, and outcomes generated by CTOL during its first 30 weeks of operation are presented. The quantitative and qualitative data suggest that CTOL is capable of making a positive contribution toward increased clinical trial awareness and accrual.