Selection of RNase-resistant RNAs.

All RNA types are susceptible to ribonuclease (RNase) digestion, which might be a serious problem for several in vitro and in vivo applications. RNase resistance can be reached through chemical modifications or the selection of stable secondary structures via SELEX (systematic evolution of ligands by exponential enrichment). This chapter focuses on the selection of natural RNase-resistant RNAs, enriched by a selection process in the presence of RNase T1. Results of these investigations led to the identification of a particular structural motif, the tetraloop. Further applications could be the advised use of such motifs in order to reach higher stability of RNA molecules.

Cancer patients' search for information.

This study explored the information-seeking behavior of 257 cancer patients or their relatives who received specific, treatment-related information from the Illinois office of the Cancer Information Service (CIS); it also explored the information-seeking behavior of a sample of 262 other cancer patients matched for age, gender, race, cancer site, and type of hospital where first seen. Among the matched patients, 53% sought information from at least one source besides their physicians. These information seekers were similar to the selected CIS patients in many respects. Compared with patients who did not seek information, both CIS patients and these other information seekers were more likely to have felt more stressed when first diagnosed, to have sought a second opinion, to have been seen at more hospitals and by more physicians since diagnosis, to prefer greater information about and involvement in their treatment plans, and to have been less confident that physicians always have the most current cancer knowledge. The majority of both information-seeking groups sought explanatory information about their cancer or treatment, and most wanted information just after their diagnosis and before starting treatment. Those in the comparison sample, however, had less well-defined questions and consulted fewer sources; only a few of them received the type of information provided by the CIS, and they were less likely to discuss with their physicians the information obtained from various sources.

Purine activity of RNase T1RV is further improved by substitution of Trp59 by tyrosine.

Ribonuclease T1 is an enzyme that cleaves single-stranded RNA with high specificity after guanylyl residues. Although this enzyme is a very good characterized protein with respect to structure and enzymatic function, we were only recently successful in generating RNase T1-RV, a variant where the specificity was changed from guanine to purine. As this change of substrate specificity was made at the cost of activity, the aim was now to further improve the overall activity of the enzyme. Therefore, we have substituted the tryptophan in position 59 by tyrosine. This substitution led to an increase of enzymatic activity in comparison to variant RV to 425%. As the extent of this enhancement is unique so far we have crystallized and analyzed the structure of this variant in order to get more insights into the reasons for this. Here, we present the crystal structure of this so-called RNase T1-R2 at 2.1A resolution. The structure was determined by molecular replacement using the coordinates of the RV variant (PDB entry: 1Q9E). The data were refined to an R-factor of 18.7% and R(free) of 24%, respectively. The asymmetric unit contains three molecules and the crystal packing is very similar to that of variant RV.

Asking Sensitive Behavioral questions in Telephone Interviews.

This article presents the results of a small pilot study to test the feasibility of telephone interviews for collecting highly sensitive data for a study of the etiology of trophoblastic disease. The study design allowed us to compare data from telephone and face-to-face interviews. The results suggest that very sensitive information can be obtained by telephone and that respondents interviewed by telephone may be more willing to report socially proscribed behavior than respondents interviewed face-to-face. A number of unanswered issues are suggested for future research.

User interactions with the PDQ cancer information system.

Searches by end users and intermediaries on the online PDQ (Physician Data Query) cancer information system were observed. With the National Library of Medicine (NLM) menu-based interface, end users (physicians) averaged fewer steps per question, while with the BRS command-drive interface, intermediaries appeared to be more efficient. Cancer Information Service (CIS) searchers, who have more PDQ experience than end users or intermediaries, made greater use of command stacking to anticipate menu selections. Retrieval was more complete in the NLM system, where both the menus and predefined print formats assisted the searchers.

Patient use of treatment-related information received from the Cancer Information Service.

This study explored patient information-seeking behavior and how such behavior might affect patient-physician interaction or health-care decisions. Telephone interviews were conducted with 257 patients with cancer and their relatives who called the National Cancer Institute's Cancer Information Service (CIS) and who received treatment-related information. Results indicated that these patients were generally very satisfied with communication from their treating physicians, had strong information needs, and preferred to participate in their treatment plans. They sought information from CIS just after diagnosis (49%) or during treatment (31%). Many of these patients (42%) discussed the CIS information with their physicians and 19% of these physicians sought more information or consulted a CIS referral. CIS referrals were contacted personally by 18% of patients. Stepwise discriminant analyses indicated that, compared with patients who did not, patients with either of these outcomes were more stressed by their disease and had been seen at more hospitals. Additionally, patients who shared CIS information with their physicians were also younger and more trusting that their physicians had current knowledge. Patients who themselves contacted a CIS referral were also more educated, had higher information needs, were less satisfied with the clarity of physicians' answers to their questions, called CIS earlier in their illness, and called specifically for a referral. Overall, these patients' most common information needs were for exploring all treatment options and being knowledgeable when discussing treatment plans with physicians. The information received from CIS satisfied these needs and was often communicated to their physicians.

Preferences of community physicians for cancer screening guidelines.

OBJECTIVE: To assess factors related to consensus among community physicians regarding appropriate screening intervals for eight cancer screening procedures for which guidelines have been published. DESIGN: Interviews were conducted with a national random sample of 3436 physicians in family practice, internal medicine, general surgery, and gynecology by mail or telephone or both. The overall response rate was 67%. MEASUREMENTS: Consensus by specialization and by physician and practice characteristics on the appropriate screening intervals for early detection of cancers of the breast, cervix, colon and rectum, and lung for asymptomatic adults at normal risk. RESULTS: More than 60% of the physicians surveyed agreed on the length of the screening intervals for six of eight procedures. Consensus most closely followed American Cancer Society- and National Cancer Institute-recommended screening intervals for all procedures except chest roentgenogram. Acceptance of screening intervals was not related to the extent of agreement among published guidelines. Surgeons tended to favor more aggressive screening than family physicians and internists; gynecologists most consistently favored aggressive screening for cancers occurring in women. Older physicians and those in solo practice tended to favor outmoded procedures such as routine chest roentgenograms and to be more conservative about screening intervals. CONCLUSIONS: Physicians stated that they follow the American Cancer Society and National Cancer Institute guidelines for cancer screening more than the guidelines published by their own specialty societies, but they also reported procedures not recommended in any guidelines. These findings suggest that changing physician screening practices will be difficult.

Prescribe for health. Improving cancer screening in physician practices serving low-income and minority populations.

OBJECTIVE: To evaluate a health maintenance organization (HMO)-sponsored intervention to improve cancer screening in private physician practices serving low-income, minority populations. DESIGN: A randomized controlled trial with preintervention and postintervention measurements. Measurements were obtained by abstracting information from independent random samples of medical charts (N = 2316 at preintervention and 2238 at postintervention). SETTING: Forty-seven primary care physician practices located in low-income and minority urban neighborhoods in Chicago, Ill. INTERVENTION: Practices were encouraged to adopt an office chart reminder system and to use a patient health maintenance card. Activities to facilitate the adoption of these items and for compliance with cancer screening guidelines included on-site training and start-up assistance visits, a physician continuing medical education seminar, and quality assurance visits with feedback to physicians. MAIN OUTCOME MEASURES: The proportions of patients with a chart-documented mammogram, clinical breast examination, Papanicolaou smear, or fecal occult blood slide test in the 2 years before preintervention and postintervention chart abstractions. RESULTS: Between baseline and postintervention, there was a net increase in the proportion of HMO members in the intervention, compared with the control practices, who received in the preceding 2 years a Papanicolaou smear (11.9%) and a fecal occult blood slide test (14.1%). There was a net increase in the proportion of non-HMO patients in the intervention compared with the control practices who received a clinical breast examination (15.3%) and a fecal occult blood slide test (20.2%). CONCLUSIONS: Implementation of an HMO-mediated, multicomponent intervention to improve cancer screening was feasible and effective for the Papanicolaou smear, fecal occult blood slide test, and the clinical breast examination, but not for mammography.