Changes in screening behaviors and attitudes toward screening from pre-test genetic counseling to post-disclosure in Lynch syndrome families.

The purpose of this study was to examine colonoscopy adherence and attitudes toward colorectal cancer (CRC) screening in individuals who underwent Lynch syndrome genetic counseling and testing. We evaluated changes in colonoscopy adherence and CRC screening attitudes in 78 cancer-unaffected relatives of Lynch syndrome mutation carriers before pre-test genetic counseling (baseline) and at 6 and 12 months post-disclosure of test results (52 mutation negative and 26 mutation positive). While both groups were similar at baseline, at 12 months post-disclosure, a greater number of mutation-positive individuals had had a colonoscopy compared with mutation-negative individuals. From baseline to 12 months post-disclosure, the mutation-positive group demonstrated an increase in mean scores on measures of colonoscopy commitment, self-efficacy, and perceived benefits of CRC screening, and a decrease in mean scores for perceived barriers to CRC screening. Mean scores on colonoscopy commitment decreased from baseline to 6 months in the mutation-negative group. To conclude, adherence to risk-appropriate guidelines for CRC surveillance improved after genetic counseling and testing for Lynch syndrome. Mutation-positive individuals reported increasingly positive attitudes toward CRC screening after receiving genetic test results, potentially reinforcing longer term colonoscopy adherence.

Oncology nurses' knowledge, practice, and educational needs regarding cancer genetics.

This study evaluated oncology nurses' knowledge of cancer genetics and related topics, and identified current practice patterns and perceived educational needs in this area. A 54-item study questionnaire was mailed to a random sample of 1,200 Oncology Nursing Society (ONS) members and 75 members of the ONS-Cancer Genetics Special Interest Group; 656 (51%) of those eligible responded. After exclusions, we analyzed 573 responses. Most respondents were Caucasian, female, and worked in hospital or outpatient settings. Half were staff nurses and 8% specialized in cancer genetics. Respondents with higher levels of nursing education or with continuing education in cancer genetics, who worked in positions other than staff nurses, and whose primary practice area was cancer genetics had significantly higher mean scores overall on questions measuring knowledge of cancer genetics and related areas. Higher perceived educational needs to improve knowledge or practice related to cancer genetics at basic, intermediate or advanced levels were associated with all or some of the following variables: lower education; hospital/ outpatient or managed care/private practice settings; lack of continuing education in cancer genetics, and positions other than advanced practice nurses. Although nearly half of the respondents had received patient inquiries regarding cancer genetics, only 35% were aware of referral resources and 26% had made such referrals. These findings may be used to develop targeted educational approaches that prepare oncology nurses to incorporate cancer genetics into any level of practice.

Shigella sonnei strains isolated from U.S. summer students in Guadalajara, Mexico, from 1986 to 1992.

Plasmid DNA analysis and antibiotic susceptibilities were used to study strains of Shigella sonnei isolated from U.S. travelers to Guadalajara, Mexico, over a period of seven years (1986 to 1992). One hundred sixty-one isolates were analyzed. By the use of cluster analysis, eight different plasmid profiles were identified during this interval. At any point in time, three to seven different plasmid profiles were present in this population. The introduction of strains that carried a new plasmid with a molecular mass of 5.1 MDa was coincidental with an increase in isolation of S. sonnei in 1988. This new plasmid was present in 87.5% of the isolates that were resistant to chloramphenicol. Shigellosis in Guadalajara follows a pattern of hyperendemic transmission with transient peaks of high-frequency isolation of S. sonnei. This pattern results from the concurrent presence of a heterogeneous group of strains as opposed to the widespread transmission of one or a few clones.

Myocardial perfusion with rubidium-82. I. Measurement of extraction fraction and flow with external detectors.

Accurate measurement of the regional extraction of a diffusible radiopharmaceutical is essential for the quantifying of regional blood flow, and may also provide an important physiologic or diagnostic indicator of the cellular viability of an organ in man through external detection by positron emission tomography. However, extraction fraction of a diffusible tracer usually decreases as flow increases, and thus noninvasive methods for measuring flow are nonlinear unless the extraction fraction can be measured independently. This report describes the theoretical basis and documents the applicability of this theory for determining, with external detectors, the first-pass regional extraction fraction of rubidium-82 by the heart, following a single intravenous bolus injection of the tracer. Measurement of extraction fraction was found to be independent of flow, thereby making it possible to determine accurately with a single intravenous bolus injection of rubidium-82, the regional blood flow in the myocardium at up to five times normal resting flow.

Myocardial perfusion with rubidium-82. II. Effects of metabolic and pharmacologic interventions.

In order to validate a new method for quantifying coronary blood flow, we injected intravenously a bolus of rubidium-82 (Rb-82) into 28 open-chested dogs under a wide range of flow and physiologic conditions, using beta probes to monitor myocardial radioactivity. Extraction fraction and perfusion were measured using a functional model that separates the data into the free and trapped myocardial rubidium. Extraction and uptake of rubidium were lower during acidosis than during alkalosis and were unchanged by glucose-insulin, digoxin, or propranolol. Myocardial flow, as indicated by rubidium, correlated linearly with simultaneous measurements of flow by microspheres in the same sample volume over a wide range of flow (r = 0.97, n = 106, range 0.02-7.76 ml/min/g). Regional myocardial blood flow can be accurately determined using generator-produced Rb-82. Studies using current state-of-the-art, fast positron-emission tomographic cameras are required to determine the utility of this approach in man.