Comparison of aortic valve gradient during exercise after aortic valve reconstruction

PURPOSE: Aortic valve preservation is a promising alternative to conventional composite replacement of aortic valve and ascending aorta. This approach may have a physiologic benefit compared with valve replacement similar to that seen in mitral valve reconstruction. We investigated aortic valve gradients at rest and during exercise in patients who had undergone valve-preserving aortic replacement and compared them with composite replacement of valve and aorta. METHODS: Four groups were studied: nine patients underwent composite valve replacement (group A: valve diameter, 23 to 27 mm), eight patients underwent remodeling of the aortic root (group B), and another nine patients had reimplantation of the aortic valve (group C). Healthy volunteers were studied as a control group (group D). Using continuous-wave Doppler echocardiography, all patients were examined on a bicycle ergometer for aortic valve gradients (0 to 75 W). RESULTS: There were no differences among the groups with respect to age, body surface, left ventricular end-diastolic diameter, fractional shortening, or left ventricular mass. Maximum resting gradients were significantly elevated in group A compared with groups B, C, and D (group A: 21.3 +/- 7.1 mm Hg; group B: 9.0 +/- 4.5 mm Hg; group C: 8.6 +/- 3.7 mm Hg; group D: 4.9 +/- 1.6 mm Hg; p < 0.05). At 75 W, group A exhibited significantly higher gradients than all other groups (group A: 31.3 +/- 7.5 mm Hg; group B: 13.9 +/- 6.6 mm Hg; group C: 12.8 +/- 3.5 mm Hg; group D: 9. 2 +/- 1.9 mm Hg; p < 0.05). There was no significant difference among the other groups. Both valve-preserving groups had only insignificantly higher gradients than the control group. CONCLUSION: Our data strongly support the suggestion that preserving the aortic valve restores nearly normal hemodynamic function of the aortic valve. Long-term observations will have to prove the clinical relevance of restoring physiologic aortic valve hemodynamics.     

Structured reporting in radiologic education – Potential of different PI-RADS versions in prostate MRI controlled by in-bore MR-guided biopsies

Objectives:To evaluate the efficiency of structured reporting in radiologic education – based on the example of different PI-RADS score versions for multiparametric MRI (mpMRI) of the prostate.Methods:MpMRI of 688 prostate lesions in 180 patients were retrospectively reviewed by an experienced radiologist and by a student using PI-RADS V1 and V2. Data sets were reviewed for changes according to PI-RADS V2.1. The results were correlated with results obtained by MR-guided biopsy. Diagnostic potency was evaluated by ROC analysis. Sensitivity, specificity and correct-graded samples were evaluated for different cutpoints. The agreement between radiologist and student was determined for the aggregation of the PI-RADS score in three categories. The student’s time needed for evaluation was measured.Results:The area under curve of the ROC analysis was 0.782/0.788 (V1/V2) for the student and 0.841/0.833 (V1/V2) for the radiologist. The agreement between student and radiologist showed a Cohen‘s weighted κ coefficient of 0.495 for V1 and 0.518 for V2. Median student’s time needed for score assessment was 4:34 min for PI-RADSv1 and 2:00 min for PI-RADSv2 (p < 0.001). Re-evaluation for V2.1 changed the category in 1.4% of all ratings.Conclusion:The capacity of prostate cancer detection using PI-RADS V1 and V2 is dependent on the reader‘s experience. The results from the two observers indicate that structured reporting using PI-RADS and, controlled by histopathology, can be a valuable and quantifiable tool in students‘ or residents’ education. Herein, V2 was superior to V1 in terms of inter-observer agreement and time efficacy.Advances in knowledge:Structured reporting can be a valuable and quantifiable tool in radiologic education. Structured reporting using PI-RADS can be used by a student with good performance. PI-RADS V2 is superior to V1 in terms of inter-observer agreement and time efficacy.     

Aging, long-distance running, and the development of musculoskeletal disability. A controlled study

Four hundred ninety-eight long-distance runners aged 50 to 72 years were compared with 365 community control subjects to examine associations of repetitive, long-term physical impact (running) with musculoskeletal disability and medical service utilization in a cross-section study. Runners had less physical disability than age-matched control subjects (p less than 0.01) and maintained more functional capacity (p less than 0.001) as measured by a modified Health Assessment Questionnaire Disability Index. Runners sought medical services less often, but one third of the visits that they did make were for running-related injuries. No differences were found between groups in conditions thought to predispose to osteoarthritis and musculoskeletal disability. Ligamentous laxity and family history of arthritis were similar in both groups. Runners demonstrated better cardiovascular fitness and weighed less. Differences persisted after adjustment for age, occupation, and sex, and after inclusion or exclusion of subjects with major medical problems. Musculoskeletal disability appeared to develop with age at a lower rate in runners (0.003 units per year versus 0.028) than in community control subjects, and the decreased rate was observed with both lower extremity and upper extremity functions. These data suggest positive effects of systematic aerobic running activity upon functional aspects of musculoskeletal aging.     

Assessment of radiologic progression in rheumatoid arthritis. A randomized, controlled trial

Radiologic assessment of progressive joint destruction in rheumatoid arthritis is generally considered to be the ultimate standard for evaluation of treatment. We compared alternative radiologic techniques by performing a randomized, controlled trial in which hand films of rheumatoid arthritis patients were read by several skilled observes. The number of joints evaluated (34 versus 18) was found to make relatively little difference, but the number of readers and their experience level was critical. Films should be read in pairs. Joint space narrowing and erosion scores were shown to contribute independent information. Use of recommended techniques can reduce the number of patients required and, thus, can reduce the cost of a clinical trial by more than half and can substantially increase the sensitivity and efficiency of a trial. Therefore, critical selection of the method of assessing study endpoint is of great importance.     

An analysis of the american rheumatism association criteria for rheumatoid arthritis

When a community-derived population of 840 rheumatoid arthritis patients was used to test the American Rheumatism Association's 11 diagnostic criteria for rheumatoid arthritis, these criteria divided patients into 3 reasonably distinct classifications (probable, definite, and classic). The severity of disease increased in direct proportion to the number of positive criteria. Three criteria involve invasive procedures that are rarely performed; they are unnecessary for effective use of the other 8 criteria. Although 256 possible combinations of these 8 criteria exist, the criteria function principally to classify patients into only 7 major clinical syndromes, each of which corresponds to a major clinical presentation. By identifying the logical interrelationships between criteria in this report, we have confirmed their applicability and provided insight into the manner by which criteria classify patients.     

Microanalysis of Worn Surfaces of Selected Rotating Parts of an Internal Combustion Engine

The present paper analyzes the damage of surfaces at spots of frictional contact, namely, the friction nodes on a camshaft and the connecting rod pins of a crankshaft. The resulting wear of the monitored friction nodes reduces the technical life of the machines, which can lead to the decommissioning of the machine. Wear was assessed by measuring roughness and microhardness and by observing the microstructures of the materials. The results of the experiments show that the rotating parts displayed visible wear on the cams, as well as on the connecting rod pins. The experiments revealed that wear was caused by the heating of the material to a high temperature during the operation of the machine and that there was a gradual cooling and tempering of the material, which led to a reduction in the microhardness of the monitored object. Lower microhardness values can be a cause of greater wear of the monitored objects. When comparing the microhardness of the used and the new camshaft, the hardened layer of the new camshaft from secondary production has a significantly smaller thickness compared to worn cams, which leads to the finding of a different material quality compared to the original parts from primary production. This fact indicates that the wear of a new camshaft as a spare part can contribute to the shortening of the technical life of friction nodes.     

A canadian study of the total medical costs for patients with systemic lupus erythematosus and the predictors of costs

Objective. We conducted a cost identification analysis on 164 consecutive patients with systemic lupus erythematosus (SLE) who entered the Montreal General Hospital Lupus Registry between January 1977 and January 1990, compared their costs to the population of Quebec, and determined the predictors of cost. Methods. In January 1990 and 1991, participants completed questionnaires on health services utilization and on employment history over the preceding 6 months, as well as on functional, psychological, and social well-being. The societal burden of SLE was determined in terms of direct costs (all resources consumed in patient care) and indirect costs (wages lost due to lack of work force participation because of morbidity). Results. The mean total annual cost for 1989, as assessed in January 1990 and expressed in 1990 Canadian dollars, was $13,094. Although only 44% of the patients were fully employed, indirect costs were responsible for 54% of this total ($7,071). Ambulatory costs, primarily diagnostic procedures, medications, and visits to health care professionals, comprised 55% of direct costs ($3,331). The results of the 1990 cost determination were similar. On average, hospitalizations among SLE patients were 4 times more frequent than among the general population of Quebec (matched for age and sex), and the number of ambulatory visits to physicians was double that for the average resident of Quebec. Higher 1989 values of creatinine and a poorer level of physical functioning were the best predictors of higher 1990 direct costs (R² = 0.29). A poorer SLE well-being score, a combination of education and employment status, and a weaker level of social support were the best predictors of higher indirect costs (R² = 0.29). Conclusion. The direct and indirect costs for patients with SLE are substantial, and their respective predictors are distinct. Direct costs arise from organic complications which induce functional disability. Predictors of indirect costs are potentially amenable to psychological or social interventions and may be more easily modified than the determinants of direct costs, thereby improving patient outcome while simultaneously reducing disease costs.