Evaluation of Pelvic Floor Muscles in Pregnancy and Postpartum With Non-Invasive Magnetomyography

Objective: To record and characterize features of levator ani muscles (LAM) activity in pregnancy and postpartum using non-invasive and novel Magnetomyography (MMG) technique with amplitude and spectral parameters. Methods: Nulliparous women with uncomplicated pregnancies participated in the MMG data collection during rest and voluntary LAM contractions (Kegels) with modulated intensity in third trimester and approximately 2 months postpartum (PP). Simultaneous surface electromyography was recorded to document the recruitment of accessory muscles. Moderate strength Kegel (MK) MMG trials were analyzed. Amplitude and spectral parameters including root-mean square (RMS) amplitude, power spectrum density (PSD) and normalized PSD (rPSD) in three frequency bands (low, middle, high) were computed on MK epochs. Statistical comparisons between pregnancy and postpartum were calculated. Results: MMG recordings were measured from 10 pregnant women. Results showed decreased RMS and power between third trimester and postpartum, trending towards significance. rPSD values in the low frequency band decreased significantly (p = 0.028) from third trimester to postpartum, while significant increase was observed in the middle frequency band (p = 0.018). Conclusions: This study shows that MMG as non-invasive tool has the ability to detect and characterize changes of LAM activity with amplitude and spectral parameters during pregnancy and postpartum.

Coupling Analysis of Fetal and Maternal Heart Rates via Transfer Entropy Using Magnetocardiography

Recent studies have shown that occasional short term coupling between fetal and maternal cardiac systems occurs. Fetal magnetocardiography (fMCG) is a non-invasive technique that records the magnetic fields associated with the electrical activity of the fetal heart through sensors placed over the maternal abdomen. The fMCG allows accurate estimation of fetal heart rates (fHR) due to its high signal-to-noise ratio (SNR) and temporal resolution. In this study, we analyzed couplingbetween fHR and maternal heart rates (mHR) using Transfer Entropy (TE). TE determines coupling between two variables by quantifying the information transferred between them in both directions. In this work, we used 74 fMCG recordings to compute TE in both directions over 1-minute disjoint time windows (TW). We examined the effect of fetal movement (FM) as a factor of influence on the TE analysis. We identified 21 subjects with FM during the recording and separated them into two gestational age (GA) groups (GA1<32 and GA2≥32 weeks). Next, TE values were compared between TWs containing non- FM with TWs containing FM using Wilcoxon Signed-Rank test. In addition, we compared TE calculations for non-FM segments obtained from the 74 subjects using Rank-Sum test in the two GA groups. Our results showed that TE values from TWs containing FM are not significantly different than those computed for TWs of non-FM. In both directions, we found that TE values obtained from the 74 subjects did not show any significant difference between GA1 and GA2 which is consistent with previous studies. Our study suggests that FM does not affect the TE computations.

Selection of Reference Channels Based on Mutual Information for Frequency-Dependent Subtraction Method Applied to Fetal Biomagnetic Signals

OBJECTIVE

We propose a method that uses minimal redundancy and maximal relevance (mRMR) based on mutual information as criteria to automatically select references for the frequency-dependent subtraction (SUBTR) method to attenuate maternal (mMCG) and fetal (fMCG) magnetocardiograms of fetal magnetoencephalography recordings.

METHODS

mRMR is calculated between all channels and mMCG/fMCG target channels and the most promising sensors are used as references to perform SUBTR. We measured the performance of SUBTR at removing interferences in two steps for different number of references in 38 real datasets. The evaluation was based on the MCG amplitude reduction. We compared the performance of the mRMR approach with random selection of references.

RESULTS

Significant differences in interference removal were found when a distinct number of references were chosen by mRMR compared to random selection.

CONCLUSION

mRMR provides an effective tool to automatically select a set of featured references.

SIGNIFICANCE

Although we show the utility of the mRMR method to biomagnetic signals, the approach can easily be adapted to sensor array data from other applications.

Abstract P1-15-02: Gene expression profiling of doxorubicin cardiotoxicity in peripheral blood cells of breast cancer patients

Background: Doxorubicin (DOX), a widely used anti-cancer drug for treatment of breast cancer is known for its cardiotoxicity. DOX cardiotoxicity is cumulative-dose-dependent and begins with the first dose of chemotherapy. To date, no biomarker for early presymptomatic detection of DOX cardiotoxicity has been validated. Our previous data indicated that peripheral blood mononuclear cells (PBMCs) can be used as a surrogate tissue for identification of biomarkers for DOX cardiotoxicity. The aim of this study was to analyze PBMC gene expression induced by a single dose of DOX-based chemotherapy in breast cancer patients and correlated the data with DOX-induced cardiotoxicity.

Materials and Methods. Blood samples of 33 women treated for breast cancer with DOX-based chemotherapy were collected before the start and after the first cycle of chemotherapy. Total RNA was isolated from PBMC and whole-genome gene expression was performed using Illumina HumanHT-12 v4 Expression BeadChip array. Gene expression data were log2 – transformed and gene transcripts with average log2-intensities &gt; 7 were considered to be expressed. The group-specific means were analyzed via repeated-measures with ANOVA for expression changes after DOX. Genes with p-value&lt;0.05 were considered differentially expressed. Cardiac function was assessed before and after the completion of chemotherapy by echocardiogram and/or multigated acquisition scan. An absolute decrease of left ventricle ejection fraction &gt;10% or &lt;55% was considered abnormal. Differentially expressed genes (DEG) of patients who developed abnormal LVEF decrease were compared with DEG of patients who did not.

Results. A single dose of DOX-based chemotherapy resulted in 235 DEG in PBMC (P&lt;0.05, FDR&lt;0.05), mapped to cell death, oxygen transport and iron ion binding. Further analysis identified 87 DEG in the PBMC of eight (n=8) women who developed abnormal decline in LVEF from the baseline in comparison with women who did not (n=25). Most of the 87 DEG encode proteins secreted by activated neutrophils, such as alpha-defensins, arginase, cathepsin G, elastase, haptoglobin. The functional analysis of the 87 DEG showed enrichment for inflammatory response, immune response, cell death and peptidase activity.

Discussion. The results from this study indicated that elevated neutrophil-associated transcripts in the early stages of DOX-based chemotherapy were independent of the neutrophil count. These data suggest an association between the neutrophils activation after a single dose of DOX-based chemotherapy and later impairment of cardiac function. The early PBMC transcriptome signature can be used in the future development of biomarkers for DOX-associated cardiotoxicity.

Citation Format: Todorova VK, Siegel ER, Makhoul I, Marquette M, Wei JY, Klimberg VS. Gene expression profiling of doxorubicin cardiotoxicity in peripheral blood cells of breast cancer patients. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-15-02.

Mammaglobin B (SCGB2A1) is a novel tumour antigen highly differentially expressed in all major histological types of ovarian cancer: implications for ovarian cancer immunotherapy

Background:

We studied the genetic fingerprints of ovarian cancer and validated the potential of Mammaglobin b (SCGB2A1), one of the top differentially expressed genes found in our analysis, as a novel ovarian tumour rejection antigen.

Methods:

We profiled 70 ovarian carcinomas including 24 serous (OSPC), 15 clear-cell (CC), 24 endometrioid (EAC) and 7 poorly differentiated tumours, and 14 normal human ovarian surface epithelial (HOSE) control cell lines using the Human HG-U133 Plus 2.0 chip (Affymetrix). Quantitative real-time PCR and immunohistochemistry staining techniques were used to validate microarray data at RNA and protein levels for SCGB2A1. Full-length human-recombinant SCGB2A1 was used to pulse monocyte-derived dendritic cells (DCs) to stimulate autologous SCGB2A1-specific cytotoxic T-lymphocyte (CTL) responses against chemo-naive and chemo-resistant autologous ovarian tumours.

Results:

Gene expression profiling identified SCGB2A1 as a top differentially expressed gene in all histological ovarian cancer types tested. The CD8+ CTL populations generated against SCGB2A1 were able to consistently induce lysis of autologous primary (chemo-naive) and metastatic/recurrent (chemo-resistant) target tumour cells expressing SCGB2A1, whereas autologous HLA-identical noncancerous cells were not lysed. Cytotoxicity against autologous tumour cells was significantly inhibited by anti-HLA-class I (W6/32) monoclonal antibody. Intracellular cytokine expression measured by flow cytometry showed a striking type 1 cytokine profile (i.e., high IFN-γ secretion) in SCGB2A1-specific CTLs.

Conclusion:

SCGB2A1 is a top differentially expressed gene in all major histological types of ovarian cancers and may represent a novel and attractive target for the immunotherapy of patients harbouring recurrent disease resistant to chemotherapy.

Serum amyloid A (SAA): a novel biomarker for uterine serous papillary cancer

Background:

Uterine serous papillary carcinoma (USPC) is a biologically aggressive variant of endometrial cancer. We investigated the expression of Serum Amyloid A (SAA) and evaluated its potential as a serum biomarker in USPC patients.

Methods:

SAA gene and protein expression levels were evaluated in USPC and normal endometrial tissues (NEC) by real-time PCR, immunohistochemistry (IHC), flow cytometry and by a sensitive bead-based immunoassay. SAA concentration in 123 serum samples from 51 healthy women, 42 women with benign diseases, and 30 USPC patients were also studied.

Results:

SAA gene expression levels were significantly higher in USPC when compared with NEC (mean copy number by RT–PCR=162 vs 2.21; P=0.0002). IHC revealed diffuse cytoplasmic SAA protein staining in USPC tissues. High intracellular levels of SAA were identified in primary USPC cell lines evaluated by flow cytometry and SAA was found to be actively secreted in vitro. SAA concentrations (μg ml⁻¹) had a median (95% CIs) of 6.0 (4.0–8.9) in normal healthy females and 6.0 (4.2–8.1) in patients with benign disease (P=0.92). In contrast, SAA values in the serum of USPC patients had a median (95% CI) of 15.6 (9.2–56.2), significantly higher than those in the healthy group (P=0.0005) and benign group (P=0.0006). Receiver operating characteristics (ROC) analysis of serum SAA to classify advanced- and early-stage USPC yielded an area under the ROC curve of 0.837 (P=0.0024).

Conclusion:

SAA is not only a liver-secreted protein but is also a USPC cell product. SAA may represent a novel biomarker for USPC to assist in staging patients preoperatively, and to monitor early-disease recurrence and response to therapy.

Venous thromboembolism (VTE) and erythropoiesis-stimulating agents (ESAs) in breast cancer: a single tertiary care center experience from the University of Arkansas for Medical Sciences (UAMS)

Abstract #6137

Introduction: ESAs have been associated with increased rates of death, myocardial infarction, stroke and venous thromboembolism(VTE) in dialysis patients especially when targeted to higher hemoglobin levels. VTE and progression of cancer have also been reported in cancer patients receiving ESAs with chemo- and/ or radiotherapy, without a strict correlation with hemoglobin levels. ESAs are the subject of intense scrutiny by the FDA and the center for Medicare and Medicaid Services. We conducted a retrospective cohort study of a relatively homogeneous group of breast cancer patients. The objectives were to detect any increased risk of VTE with ESA exposure, and to correlate it with the hemoglobin/hematocrit levels.&#x2028; Methods: Data were extracted from Logician, an electronic medical record database used in the Medical Oncology Clinic at UAMS. The study cohort included breast cancer patients treated at UAMS with chemotherapy between July 1, 2004 and July 1, 2007. Patients with prior history of VTE were excluded. The patients were followed until September 9, 2007 for ESA(Erythropoietin/Darbepoietin) exposure and development of VTE. The association between ESA exposure and VTE development was assessed using Cox regression with ESA exposure as a time-dependent covariate, and the results were reported as the hazard ratio (HR) along with associated chi-square statistic and p value.&#x2028; Results: 483 patients (482 female, 1 male) met the study inclusion criteria. Median (range) age was 56 yrs (27-89). 107 (22%) were African American, 361 (75%) were Caucasian, and 15 (3%) in other categories. 9 out of the total 483 pts (1.86%) developed a VTE [7 Deep Vein Thromboses (DVTs) and 2 pulmonary embolism (PE)]. 63 subjects (13%) were exposed to ESAs during the study period, and 1 of them developed a DVT. The mean Hgb/Hct in the 62 patients exposed to ESAs who did not develop VTE was 11.34/35.26; the 1 patient exposed to ESA with DVT had a Hgb/Hct of 12.5/37.9. Among the 420 patients not exposed to ESAs, 6 developed a DVT; their mean Hgb/Hct was 12.95/39.4. The 414 pts without a DVT had mean Hgb/Hct of 12.66/38.55. Comparisons of the Hgb/Hct values in the various groups with or without VTE and, with or without ESA exposure showed no significant differences between any of the groups. Cox regression showed little evidence of increased risk with ESA use for either VTEs in general (HR=1.83; X21=0.57, P=0.45) or DVT in particular (HR=1.08; X21=0.005, P=0.94).&#x2028; Conclusions: The number of VTEs in the study patients was very small, and much lower than previous reports. There was no evidence of increased risk of VTE from ESA exposure. However, due to the small number of events, this study lacked the power to detect an ESA effect unless the effect was huge. On the other hand, the very small number of VTEs in the ESA- exposed patients to may reflect our conservative ESA usage in breast cancer patients, and is reassuring that when used appropriately, ESA use is safe.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6137.

Thiazolidinedione (TZD) exposure and risk of squamous cell carcinoma of head and neck (SCCHN)

1511

Background: Peroxisome proliferator-activated receptor γ (PPARγ), a nucleic acid receptor, heterodimerizes with retinoic acid X receptor (RXR). Ligand activation of RXR leads to decreased proliferation of SCCHN cell lines. TZDs (syn: glitazones), used to treat diabetes mellitus (DM), are ligands for the RXR:PPARγ heterodimer. A retrospective study of diabetics attending the Veterans Affairs (VA) health care system was undertaken to assess the association between TZD exposure and the risk of developing SCCHN. Methods: Data were obtained from the electronic patient database VISN 16 (covering 10 VA institutions) for males aged ≥40 presenting with DM and no prior SCCHN between 10/01/96 and 12/31/03. DM and SCCHN diagnoses were identified using ICD9 codes. Subjects were followed until 12/31/05, and analyzed for SCCHN risk via Cox regression, using time-dependent covariates to model exposure to TZDs, insulin and other anti-DM agents. Results: 130,406 subjects met the study criteria. Median (quartiles) age at DM presentation was 64 (55–72).18.5% were African-American, 61.3% were Caucasian, and 20.2% were other/unknown. The table shows TZD exposure, SCCHN incidence and hazard ratios for SCCHN with exposure to TZD alone or in combination with insulin and other anti-DM agents after adjusting for age, race, BMI, and HbA1C. Conclusions: A 41%-55% reduction in the risk of SCCHN was observed in diabetic subjects treated with TZD alone, with insulin, and with other anti-DM agents. The decrease was statistically significant (P<0.05) for TZD alone and TZD with other agents, but not for TZD with insulin. These findings suggest a protective effect of TZD on the development of SCCHN. The mechanism is not clearly known but possibly mediated through RXR:PPARγ pathway.

[Table: see text]

No significant financial relationships to disclose.

Contribution of de novo point mutations to the overall mutational burden in mitochondrial DNA of adult rats

This study analyzed the incidence of point mutations in mitochondrial DNA of brain and muscle tissues from young (6-month) and old (24-month) male F344 rats. Coding sequence mutations in subunit 5 of the NADH dehydrogenase gene were detected after high-fidelity PCR amplification and cloning by denaturing gradient gel electrophoresis (DGGE) assay followed by sequencing of detected mutants. In total, almost a thousand individual clones were analyzed both in brain and muscle samples. On average, mtDNA from brain tissue showed a 66% increase with age in mutation frequencies (2.3+/-1.9 vs. 3.8+/-4.5 x 10(-4) mutations/bp, mean+/-SD), which failed to reach statistical significance (p=0.45). Muscle tissues yielded substantially fewer mutants with average mutant frequencies for both young and old rats almost 10 times lower than the corresponding values in the brain tissue (0.3+/-0.4 and 0.5+/-0.6 x 10(-4), respectively). The difference in mutation accumulation between muscle and brain was highly significant in both the younger group (Chi-squared=9.7, p < or = 0.01) and in older animals (Chi-squared=10.9, p < or = 0.001). Molecular analysis of the mutated sequences revealed that almost half were identical sequences recurring in different samples and tissues. Our findings indicate that the process of mutation accumulation in mitochondria begins in the germ-line and/or during earlier stages of life, contributing up to half of the total mutational burden, whereas de novo spontaneous formation of point mutations in adulthood is far less than was anticipated.

Enhancing communications and connectivity in Africa: the multilateral initiative on malaria (MIM) model

The U.S. National Library of Medicine, working in concert with the Multilateral Initiative on Malaria (MIM), has developed and implemented a unique organizational and technical strategy to connect malaria research sites to the Internet for purposes of facilitating North-South scientific communications and access to electronic information resources on the Web. The model employs microwave and VSAT technologies, and shares bandwidth and costs among participating malaria research sites and their respective research funders in Mali, Kenya, Ghana, Tanzania and other sub-Saharan locations affiliated with MIM. The concept of institutional partnership is an essential element of this information technology capacity building effort, which may find applicability in other developing regions of the world with similar communications and research networking needs and capabilities.

Public library consumer health information pilot project: results of a National Library of Medicine evaluation

In October 1998, the National Library of Medicine (NLM) launched a pilot project to learn about the role of public libraries in providing health information to the public and to generate information that would assist NLM and the National Network of Libraries of Medicine (NN/LM) in learning how best to work with public libraries in the future. Three regional medical libraries (RMLs), eight resource libraries, and forty-one public libraries or library systems from nine states and the District of Columbia were selected for participation. The pilot project included an evaluation component that was carried out in parallel with project implementation. The evaluation ran through September 1999. The results of the evaluation indicated that participating public librarians were enthusiastic about the training and information materials provided as part of the project and that many public libraries used the materials and conducted their own outreach to local communities and groups. Most libraries applied the modest funds to purchase additional Internet-accessible computers and/or upgrade their health-reference materials. However, few of the participating public libraries had health information centers (although health information was perceived as a top-ten or top-five topic of interest to patrons). Also, the project generated only minimal usage of NLM's consumer health database, known as MEDLINEplus, from the premises of the monitored libraries (patron usage from home or office locations was not tracked). The evaluation results suggested a balanced follow-up by NLM and the NN/LM, with a few carefully selected national activities, complemented by a package of targeted activities that, as of January 2000, are being planned, developed, or implemented. The results also highlighted the importance of building an evaluation component into projects like this one from the outset, to assure that objectives were met and that evaluative information was available on a timely basis, as was the case here.

G7: a framework for international cooperation in medical informatics

The world's major economic powers, the G7, have initiated a collaborative International research and demonstration program to exploit the benefits of information and communications technology for society. The Global Healthcare Applications Project (GHAP) is investigating a variety of informatics applications in disease specific domains, telemedicine, and multilingual textual and image database systems. This paper summarizes the nine GHAP sub-projects undertaken to date, with emphasis on those in which the U.S. is a participant. The growing use of smart card technology, especially in Europe, is adding new impetus for similar medical and health experiments in the U.S. A pilot project now underway in several Western states is described.

Evaluating Internet end-to-end performance: overview of test methodology and results

OBJECTIVE

An evaluation of Internet end-to-end performance was conducted for the purpose of better understanding the overall performance of Internet pathways typical of those used to access information in National Library of Medicine (NLM) databases and, by extension, other Internet-based biomedical information resources.

DESIGN

The evaluation used a three-level test strategy: 1) user testing to collect empirical data on internet performance as perceived by users when accessing NLM Web-based databases, 2) technical testing to analyze the Internet paths between the NLM and the user's desktop computer terminal, and 3) technical testing between the NLM and the World Wide Web ("Web") server computer at the user's institution to help characterize the relative performance of Internet pathways.

MEASUREMENTS

Time to download the front pages of NLM Web sites and conduct standardized searches of NLM databases, data transmission capacity between NLM and remote locations (known as the bulk transfer capacity [BTC]), "ping" round-trip time as an indication of the latency of the network pathways, and the network routing of the data transmissions (number and sequencing of hops).

RESULTS

Based on 347 user tests spread over 16 locations, the median time per location to download the main NLM home page ranged from 2 to 59 seconds, and 1 to 24 seconds for the other NLM Web sites tested. The median time to conduct standardized searches and get search results ranged from 2 to 14 seconds for PubMed and 4 to 18 seconds for Internet Grateful Med. The overall problem rate was about 1 percent; that is, on the average, users experienced a problem once every 100 test measurements. The user terminal tests at five locations and Web host tests at 13 locations provided profiles of BTC, RTT, and network routing for both dial-up and fixed Internet connections.

CONCLUSION

The evaluation framework provided a profile of typical Internet performance and insights into network performance and time-of-day/day-of-week variability. This profile should serve as a frame of reference to help identify and diagnose connectivity problems and should contribute to the evolving concept of Internet quality of service.

Transitioning to the Internet: results of a National Library of Medicine user survey

In late 1995, several months prior to the introduction of Internet Grateful Med, the National Library of Medicine (NLM) conducted a customer survey as part of its efforts to make a transition from Grateful Med to new forms of electronic information access and retrieval. A questionnaire survey was mailed to a sample of 2,500 online users randomly selected from domestic users (excluding fixed-fee users) who searched NLM databases during the second quarter of 1995. The final response rate was nearly 83% of eligible respondents. About 70% of NLM customers responding already had access to the Internet, and of those, more than 90% had access to the World Wide Web. However, only 26% of customers with Internet access were using the Internet to access NLM databases. Health care providers account for about 46% of NLM customers but, as a group, search NLM databases relatively infrequently even though they have higher-end equipment. Librarians and information professionals represent about one-fifth of NLM customers and are by far the most intensive users, but tend to have lower-end equipment. Overall, the survey results provide a strong basis for the transition to Internet-based delivery of NLM online database services, including Internet Grateful Med and the NLM family of World Wide Web sites. However, Internet access is uneven, especially in rural areas and at hospitals. This reinforces the need for continuing special outreach efforts directed at improving access for rural and hospital-based users and rural libraries, upgrading computer equipment for medical librarians, and training health care providers in more effective use of Internet-based biomedical information resources.

Outreach activities of the National Library of Medicine: a five-year review

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Use of MEDLINE by physicians for clinical problem solving

OBJECTIVE

To understand the ways in which computer-mediated searching of the biomedical literature affects patient care and other professional activities. Undertaken to determine the ways in which on-line access to the biomedical literature via the National Library of Medicine's MEDLINE database "makes a difference" in what physicians do when confronted with a medical problem requiring new or additional information.

DESIGN

An adaptation of the Critical Incident Technique used to gather detailed reports of MEDLINE search results that were especially helpful (or not helpful) in carrying out the individual's professional activities. The individual physician was the source of the patient care incident reports. One thousand one hundred fifty-eight reports were systematically analyzed from three different perspectives: (1) why the information was sought; (2) the effect of having (or not having) the needed information on professional decisions and actions; and (3) the outcome of the search.

PARTICIPANTS AND SETTING

Telephone interviews were carried out with a purposive sample of 552 physicians, scientists, and other professionals working in a variety of clinical care and other settings. Of these, 65% were direct users of MEDLINE throughout the United States, and 35% had MEDLINE searches conducted for them either at a major health sciences center or in community hospitals.

RESULTS

Three comprehensive and detailed inventories that describe the motivation for the searches, how search results affected the actions and decisions of the individual who initiated the search, and how they affected the outcome of the situation that motivated the search.

CONCLUSIONS

MEDLINE searches are being carried out by and for physicians to meet a wide diversity of clinical information needs. Physicians report that in situations involving individual patients, rapid access to the biomedical literature via MEDLINE is at times critical to sound patient care and favorably influences patient outcomes.

Evaluating the impact of MEDLINE using the Critical Incident Technique

An adaptation of the Critical Incident Technique for the evaluation of an online information system is described. 552 users of the National Library of Medicine's MEDLINE database, interviewed by telephone and responding to a highly structured set of open-ended questions, reported 1,158 incidents in which the results of a MEDLINE search was especially helpful (or not helpful) in carrying out professional activities. Systematic analysis of these "critical incidents" produced three comprehensive and detailed views of the purposes and outcomes of MEDLINE searches: (1) why information is sought from MEDLINE; (2) the impact of MEDLINE-derived information on medical decision-making; and (3) the ultimate outcome of having (or not having) the desired information on medical situations prompting a MEDLINE search. Results revealed that MEDLINE is used to satisfy a diversity of medical needs concerning patient care, the progress of biomedical research, the quality of education received by health professionals in training, the safety and effectiveness of health care institutions, the operation of the system of third-party reimbursement, for legal decisions, and for the knowledge of the public.

Production of Epoxides from α,β-Halohydrins by Flavobacterium sp

The relative activity of Flavobacterium whole cells on the enzymatic synthesis of epoxides from α,β-chlorohydrins, -bromohydrins, and -iodohydrins is described.

The hepatitis knowledge base. A prototype information transfer system

The Hepatitis Knowledge Base is a prototype computerized information-transfer system aimed at supporting the health practitioner's day-to-day diagnosis, prognosis, and treatment decisions concerned with viral hepatitis. An overview of information-transfer problems in biomedicine is presented and issues pertinent to the knowledge-base concept are discussed. The following research activities are described: selection and organization of the content of the initial draft of the complete Hepatitis Knowledge Base; the method for consensus development by a nationally distributed panel of collaborating experts on the subject matter; methods for updating the knowledge base and maintaining its currency over time; use of a computer conferencing network as the principal medium of communication among the geographically dispersed experts and the project staff; support of on-line access to the knowledge-base contents; and formative evaluation of the above methods and limited field testing of the access system.