A cytochrome P450 and a ferredoxin isolated from Mycobacterium sp. strain HE5 after growth on morpholine.

A cytochrome P450 and an iron-sulfur protein, whose expression was specifically induced during growth of Mycobacterium sp. strain HE5 on morpholine as the sole source of carbon, nitrogen, and energy were purified to apparent homogeneity. Due to the lack of enzymatic activity, carbon monoxide difference spectra and determination of the acid-labile sulfur, respectively, were used to detect the proteins during purification. The cytochrome P450, designated P450mor, was characterized as a monomer with an apparent molecular mass of 44.7 kDa. The amino acid sequence of an internal peptide comprising 19 amino acids was identical to the sequence derived from a gene encoding a cytochrome P450 from Mycobacterium smegmatis mc(2)155 suggested to be involved in the utilization of piperidine and pyrrolidine. The iron-sulfur protein was characterized as a ferredoxin exhibiting a molecular mass of 6.8 kDa and named Fdmor. An identity of 48-77% was obtained for the 30 N-terminal amino acids of Fdmor and the corresponding sequences of different 3Fe-4S-ferredoxins known to be involved in P450-dependent reactions. From these data we concluded that growth of Mycobacterium sp. strain HE5 on morpholine led to the expression of a cytochrome P450-dependent monooxygenase system composed of at least two different proteins.

Outcome of double-blind, placebo-controlled food challenge tests in 107 children with atopic dermatitis.

BACKGROUND AND OBJECTIVE: Little is known about late phase clinical reactions during oral food challenges and the value of specific IgE in terms of sensitivity and specificity. METHODS: We therefore analysed retrospectively the clinical outcome of 387 oral provocations during double-blind, placebo-controlled food challenge tests in 107 children with atopic dermatitis. RESULTS: Eighty-seven (81%) children showed a positive clinical reaction to at least one challenge. The vast majority of children (94%) showed clinical symptoms to one or two allergens. One hundred and thirty-one of 259 (51%) of verum challenges and 1/128 (0.8%) placebo challenge were assessed as positive. Oral provocations with hen's egg showed the highest percentage of positive reactions (70%). Sensitivity of specific IgE to the four allergens tested was 90%, specificity 30%. Sensitivity of the parental history as a predictive factor was 48%, specificity 72%. Ninety-two of 131 (70%) children with positive verum provocations showed early reactions, 33 (25%) late and six (5%) combined early and late reactions. In 84/131 (64%) positive provocations one organ system was involved, while in 44 (34%) provocations two and in three (2%) challenges three organ systems were involved. Skin reactions were the most frequent clinical manifestation leading to positive reactions followed by gastro-intestinal and respiratory symptoms. There was no correlation between titration dose and specific IgE. The subgroup of non-sensitized children did not differ in terms of sex, age or titration dose from the total study population. CONCLUSION: Double-blind, placebo-controlled oral food challenges are helpful in distinguishing children with clinically manifested symptoms from those with food sensitization. Accurately identifying children with a clinical relevant food allergy may help to prescribe specific diets on a scientific basis, avoiding dietary limitations which may be unnecessary or even harmful.

Closing the clinical laboratory testing loop with information technology.

Information technology can enhance the effectiveness of the part of the laboratory testing loop that occurs outside of the clinical laboratory. That external component involves the presentation of laboratory results and related information to physicians and the reception of physician requests for follow-up testing. Improvements made in the clinician-computer interface can conceivably enhance the quality of information transfer of this part of the testing loop and thereby improve the effectiveness of the entire loop. Our experience has been that results presentation is easier to address than order reception and that the economic benefits from improved result presentation can be substantial. Improving order reception requires more finesse, especially with the limitations of today's health systems and their information systems in mind. For instance, effective computer-based management of prospectively developed orders (eg, clinical protocols) not only can have a substantial positive impact on test use, but is actually welcomed by clinicians. Application of information technology at the clinician-computer interface has good potential to foster more appropriate use of clinical laboratory resources.

The clinical workstation as a means of improving laboratory use.

Driven to make timely decisions, doctors may act with less than all of the relevant patient data. Sub-optimal use of clinical laboratory resources can result. Our clinicians' workstation (CWS) is meant to provide doctors and nurses ready access to laboratory results in a form that makes the data easy to review and use. In addition, the workstation provides immediate feedback regarding blood orders, to encourage appropriate clinical practice. Feedback is based on the medical staff's clinical guidelines that have been incorporated into an embedded expert system. CWS also helps blood bank physicians to monitor, review and control requests for special needs such as irradiated products. Challenges to system acceptance await those trying to bring functional decision support to the clinical environment. Among these are barriers to understanding and cooperation posed by departmental boundaries and interacting professional cultures as well as the politics of hospital-based information systems.

A clinician's workstation for improving laboratory use. Integrated display of laboratory results.

Physicians are often forced to make decisions about the use of laboratory resources without adequate access to earlier results and related supporting information. Less than optimal use of the laboratory may result. The authors developed and deployed a clinical workstation meant to provide ready access to laboratory information that is presented in a format well-matched to the patient monitoring task. The workstation was one element of a multifaceted effort to improve blood component use in adult and pediatric bone marrow transplantation units. It was the sole intervention focused on improving laboratory testing. In the 2 years since the introduction of the workstation, median charges of bone marrow transplantation cases for laboratory test fell by 32%. This reduction in charges has been maintained for 2 years. Better informed physicians appear to use laboratory resources more sparingly.

Integrating legacy laboratory information systems into a client-server world: the University of Minnesota Clinical Workstation (CWS) project.

The development of an innovative clinical decision-support project such as the University of Minnesota's Clinical Workstation initiative mandates the use of modern client-server network architectures. Preexisting conventional laboratory information systems (LIS) cannot be quickly replaced with client-server equivalents because of the cost and relative unavailability of such systems. Thus, embedding strategies that effectively integrate legacy information systems are needed. Our strategy led to the adoption of a multi-layered connection architecture that provides a data feed from our existing LIS to a new network-based relational database management system. By careful design, we maximize the use of open standards in our layered connection structure to provide data, requisition, or event messaging in several formats. Each layer is optimized to provide needed services to existing hospital clients and is well positioned to support future hospital network clients.

The deployment of a World Wide Web (W3) based medical information system.

The development of Web technologies has revolutionized information dissemination on the Internet. The University of Minnesota Hospital and Clinic's Web Clinical Information System (CIS) demonstrates the use of the Web as an infrastructure for deploying a medical information system at a fraction of the developmental cost of more traditional client server systems. This Web CIS has been deployed since December 1994. It makes available laboratory results, including a radically improved clinical microbiology reporting system, ad hoc laboratory order entry, and an embedded expert system protocol laboratory ordering system. It provides these services to any physician or patient care area with TCP (or SLIP/PPP) connection to our hospital network backbone, whether the client computer is running MS Windows, the Macintosh OS, or X-Windows. A formal evaluation of one of this systems subcomponents, the display of clinical microbiology information, demonstrated a significant savings in clinician time (43% p < .001) and substantial reduction in interpretive errors (0 vs 15 p < .01).

Maternal time and the care of disabled children.

Caring for disabled children has become increasingly the responsibility of parents, even when the medical care is complex. To assess the time commitment required, 133 mothers of disabled children were asked to estimate by specific task categories the extra time required to care for the children. Total average daily care time was reported at 12 hours and 6 minutes, with 6 hours and 30 minutes consumed in "vigilant" tasks (i.e., watching a child who cannot be left alone and/or providing emotional support). Multiple regression analysis showed an increase in total caregiving hours associated with a younger child who was more physically and mentally impaired, and who required more medical treatments. The amount of time required by parents to care for their chronically ill children of necessity results in lost opportunities. Because this burden is experienced primarily by women and because professional nurses could alleviate some of the burden, this issue deserves further study.

Determinants of home care nursing hours for technology-assisted children.

In the 1980s home care, in contrast to hospital care, was reported substantially to reduce costs for third-party payers who provided funding for technology-assisted children. Savings were realized primarily because parents substituted for nurses, eliminating or reducing those costs. Third-party payers' savings thus were directly related to the number of hours parents assumed care. Because home care relies on parents doing some of the work of nurses, decisions regarding nursing hours must consider family factors in addition to medical factors. We evaluated the number of nursing hours 31 Minnesota families with technology-assisted children received, as well as the factors that determined the allotment of nursing hours. Most families (96.8%) received some hours of nursing hours. Most families (96.8%) received some hours of professional nursing care per day, and 16.1% received 24-hour care. Multiple regression, however, showed that family factors, rather than the child's medical condition, influenced the number of hours, with married, lower-income families with a younger child receiving the fewest. Further discussion and study are recommended to understand more fully the impact family factors have on the allotment of nursing hours and home care costs.

Self-concept of children and adolescents with cleft lip and/or palate.

The self-concept of 105 children (8 to 11 years) and adolescents (12 to 18 years) with cleft lip and/or palate (CLP) was studied using the Piers-Harris Children's Self-Concept Scale and selected demographic and medical variables. Results indicated that most (98%) of children had average or above average self-concept scores. Further analysis, however, demonstrated an interaction between age and gender: adolescent girls experienced a more negative self-concept in comparison to younger girls and adolescent boys experienced a more positive self-concept in comparison to younger boys. In addition, popularity cluster scores for all children were below the mean for the normed population. Because children with CLP have additional difficulties (i.e., facial disfigurement, speech and language deficits, multiple surgeries), professionals should intercede to prevent or interrupt negative psychosocial outcomes, particularly for adolescent girls.

Design and preliminary evaluation of an expert system for platelet request evaluation.

In spite of growing awareness of the potential risks associated with transfusion, the number of platelet units transfused in the United States continues to increase each year. There is a growing interest in ensuring that all transfusions are administered for appropriate reasons. Prospective review of requests for transfusions has been used to accomplish this goal. Although successful in reducing the number of inappropriate transfusions, this review method requires great time commitments by blood bank personnel and physicians. A knowledge-based system (ESPRE) that aids hospital blood bank personnel in the review of requests for platelet transfusions has been developed. The system automatically obtains most of the required patient data via a direct link to the hospital's main laboratory computers. The system generates a printed report that includes a list of patient-specific data, a list of the conditions for which a transfusion would be appropriate for the particular patient (given the clinical condition), and the conclusions drawn by the system. During a preliminary clinical evaluation of ESPRE, 73 randomly selected platelet transfusion requests were evaluated for approval by laboratory personnel and ESPRE. Overall, ESPRE would have approved 71 of the requests and laboratory staff would have approved 72. Forty-four percent of the requests would have been approved for the same reasons given by the staff. There were only three disagreements on final approval between ESPRE and blood bank personnel. This computerized expert system is a promising approach to the prospective review of all platelet transfusions.

ESPRE--expert system for platelet request evaluation.

The expert system for platelet request evaluation (ESPRE) is being developed to support independent learning and decision making regarding the use of platelet transfusions while physicians are actively engaged in clinical practice. The knowledge of transfusion medicine incorporated in ESPRE has been largely gathered from blood bank physicians responsible for determining the appropriateness of blood product administration. Knowledge acquisition methods have included structured and unstructured interviews with protocol analysis using real and fabricated transfusion cases and critiques of an expert system prototype's conclusions. For knowledge representation, ESPRE uses frames with embedded production rules to provide processing efficiency and facilitate knowledge base development. ESPRE automatically acquires key laboratory findings from a laboratory information system. Systems such as ESPRE require careful evaluation and, if proven effective and accurate, present to laboratorians a new tool for delivering high-quality and individually adapted health care.

Computerized collection and analysis of dietary intake information.

A computer system has been developed which facilitates standardized and in-depth collection and analysis of dietary intake information required for nutritional research. The system uses a hierarchically arranged database of food descriptions. A user identifies a consumed food by traversing a hierarchy and reaching a leaf node food item via a succession of selections from menu displays. If a food contains ingredients or was cooked with additional fat or salt, multiple traversals of the food hierarchies are necessary. The system assigns one or more food codes and determines the gram weight of the food consumed using everyday measures such as cups, slices, ounces, etc. It then uses these food codes and gram weights to calculate nutrient content. Utilizing binary trees and physical pointers to expedite data retrieval from this nearly 10 Mbyte database permits the system's use in conducting real-time interactive interviews.

ESPRE: a knowledge-based system to support platelet transfusion decisions.

ESPRE is a knowledge-based system which aids in the review of requests for platelet transfusions in the hospital blood bank. It is a microcomputer-based decision support system written in LISP and utilizes a hybrid frame and rule architecture. By automatically obtaining most of the required patient data directly from the hospital's main laboratory computers via a direct link, very little keyboard entry is required. Assessment of time trends computed from the data constitutes an important aspect of this system. To aid the blood bank personnel in deciding on the appropriateness of the requested transfusion, the system provides an explanatory report which includes a list of patient-specific data, a list of the conditions for which a transfusion would be appropriate for the particular patient (given the clinical condition), and the conclusions drawn by the system. In an early clinical evaluation of ESPRE, out of a random sample of 75 platelet transfusion requests, there were only three disagreements between ESPRE and blood bank personnel.

Novel approach to bacterial identification that uses the autobac system.

A new system for the rapid identification of gram-negative bacilli on the Autobac system is described. This system utilizes growth inhibition profiles to a panel of differentially inhibitory chemical agents. These profiles are analyzed with a two-stage quadratic discriminant analysis to arrive at the organism identification. The system identifies 30 different groups of gram-negative bacilli, including the most clinically significant Enterobacteriaceae and glucose nonfermenters. A total of 3,726 strains, distributed among the 30 groups, was tested. The Autobac system agreed with the conventional biochemical identification 88.4% of the time. When the individual group results were weighted to reflect clinical frequency, the result was a 93.1% agreement.

Accuracy and precision of the autobac system for rapid identification of Gram-negative bacilli: a collaborative evaluation.

Gram-negative bacilli were identified within 3 to 6 h by determining susceptibility to 18 different antibacterial agents in the Autobac I system and by applying a two-stage quadratic discriminant analysis to the susceptibility patterns. The Autobac system was compared with standard reference methods for identifying glucose nonfermenters and glucose fermenters. Intralaboratory and interlaboratory precision of the Autobac system was comparable to that of the reference methods. Sensitivity (accuracy) and specificity of the two systems were also comparable, although there were some differences with certain species. Autobac responses were considered to be equivocal (needing additional tests) if the relative probability of an accurate identification was less than 0.70. Only 5% of 2,889 strains produced such equivocal results; a similar number of strains gave low probability levels with the reference methods. When the two systems disagreed, an independent reference laboratory arbitrated, confirming 49% of the Autobac responses and 36% of the reference identifications. With equivocal responses excluded, the overall accuracy of the Autobac system was 95.3% compared with 95.9% for the reference method. The respective accuracy estimates would be 93.8% and 93.1% if all first-choice identifications were evaluated.

Automated, rapid identification of bacteria by pattern analysis of growth inhibition profiles obtained with Autobac 1.

A scheme for identifying bacteria has been devised which utilizes the inhibition patterns obtained by Autobac 1 with routine and unusual antimicrobial agents and with other differentially inhibitory chemical compounds. Over 600 compounds were initially identified from the literature, and over 125 of these were selected for further testing on the basis of antibacterial activity most conducive to the instrument-generated differential scheme. Numerical growth index information derived by light scatter comparisons from the instrument were analyzed by computer, utilizing the quadratic discriminant function statistical technique. In comparison with conventional methods, accuracy for the 10 bacterial genera studied was 95% or greater. Results indicate a potential for both bacterial identification and antimicrobial agent susceptibility testing in the clinical laboratory within 3 to 5 h when using this automated approach.

Computer-assisted bacterial identification utilizing antimicrobial susceptibility profiles generated by autobac 1.

A computer program was developed to identify bacteria solely on the basis of their relative susceptibility to various antimicrobial agents. A sample of 481 clinical isolates from nine of the most commonly isolated gram-negative groups was identified by the quadratic discriminant function technique. Various combinations of antimicrobials were tried, and one set of 18 resulted in a more than 97% correlation with conventional identification procedures. The antimicrobial set could be decreased to 14, while a better than 95% correlation with the conventional procedures was maintained.