Self-Organization and Phase Transitions in Driven Cellular Automata.

The Game of Life (GoL) cellular automaton is modified to inject order during execution of the state transition algorithm by making selected stable structures permanently active while interacting with normal active sites to create novel structures. A survey of the modified automaton's phenomenology and an analysis of its dynamics are presented in the context of the physics of the self-organization of matter by viewing the GoL as an artificial chemistry. These new structures become seeds for additional phases of structure building, analogous to nature's gravitational and thermodynamic churning of the geosphere that created material structures in phases, beginning the transition from geochemistry to prebiotic chemistry and laying foundational substrates for life-enabling organizational processes in an emerging biosphere. Evidence of selective self-assembly during phase transitions is reported where several GoL still life structures, configured as permanently active seeds evolving with random collections of active sites, resulted in geometrically identical structures as the GoL reached an equilibrium state of static density.

Feasibility of common bibliometrics in evaluating translational science.

INTRODUCTION: A pilot study by 6 Clinical and Translational Science Awards (CTSAs) explored how bibliometrics can be used to assess research influence. METHODS: Evaluators from 6 institutions shared data on publications (4202 total) they supported, and conducted a combined analysis with state-of-the-art tools. This paper presents selected results based on the tools from 2 widely used vendors for bibliometrics: Thomson Reuters and Elsevier. RESULTS: Both vendors located a high percentage of publications within their proprietary databases (>90%) and provided similar but not equivalent bibliometrics for estimating productivity (number of publications) and influence (citation rates, percentage of papers in the top 10% of citations, observed citations relative to expected citations). A recently available bibliometric from the National Institutes of Health Office of Portfolio Analysis, examined after the initial analysis, showed tremendous potential for use in the CTSA context. CONCLUSION: Despite challenges in making cross-CTSA comparisons, bibliometrics can enhance our understanding of the value of CTSA-supported clinical and translational research.

Amino-terminated PAMAM dendrimers electrostatically uptake numerous anionic indicators.

Generational trends in the uptake of multiple anionic indicators by unmodified commercially-available PAMAM dendrimers are described, and evidence of an electrostatic driving force in these high stoichiometry indicator-dendrimer interactions is offered.

Grading the graders: how hospitals in California and New York perceive and interpret their report cards.

BACKGROUND: Concerns about quality of care are increasing as hospitals struggle to lower costs. Hospital report cards are controversial, but little is known about their impact. OBJECTIVES: To determine whether recent hospital report cards are viewed more favorably than pioneering federal efforts; whether a report based on clinical data is viewed more favorably than one based on administrative data; and whether attitudes toward report cards are related to hospital characteristics. DESIGN: Mailed survey of chief executives at 374 California hospitals and 31 New York hospitals listed in report cards on myocardial infarction and coronary bypass mortality. SUBJECTS: Two-hundred-and-seventy-four hospitals in California (73.3% response) and 27 in New York (87.1% response). California hospitals were categorized on ownership, size, occupancy, risk-adjusted mortality, teaching status, patient volume, and surgical capability. MEASURES: Number of hospital units that received or discussed the report card, ratings of its quality, perceptions of its usefulness, and knowledge of its methods. RESULTS: In both states, report cards were widely disseminated within hospitals. The mean quality rating was higher (P = 0.0074) in New York than in California; New York respondents appeared to be more knowledgeable about key methods. One or more hospital characteristics was associated with each outcome measure. Leaders at high-mortality hospitals were especially critical and did not find the report useful, despite limited understanding of its methods. CONCLUSIONS: Recent hospital report cards were rated better than pioneering federal efforts. A report based on clinical data was rated better, understood better, and disseminated more often to key staff than one that was based on administrative data. Barriers to constructive use of outcomes data persist, especially at high mortality hospitals.

Interventional uroradiology.

The development of interventional uroradiologic techniques has had a major impact on the care of the urologic patient by allowing nonoperative treatment of many disease processes. This article will review percutaneous nephrostomy with emphasis on urologic calculi, interventional therapy for neoplasms and trauma of the urinary tract, diagnosis and treatment of renovascular hypertension, and the management of complications following renal transplantation.

The California Hospital Outcomes Project: how useful is California's report card for quality improvement?

BACKGROUND: Hospital report cards have proliferated in the 1990s but remain controversial because risk-adjusted outcomes measures are complex and have uncertain validity. Despite this controversy, little is known about their value and impact. METHODS: A two-stage survey of hospital leaders in California was undertaken in September 1996 and July 1997 to explore how the 1996 reports and data from the California Hospital Outcomes Project (CHOP) were used to improve organizations' performance. In the first stage, a questionnaire was mailed to the chief executive officer of each hospital in the report. In the second stage, a stratified random sample of the respondents who indicated a willingness to provide further information was interviewed. RESULTS: Thirty-nine interviews were completed, representing 87% yield after replacing informants who failed to return six messages. About three-quarters of the interviewees found some aspect of the CHOP report to be useful, especially for benchmarking performance, improving ICD-9-CM (International Classification of Diseases, 9th Revision, Clinical Modification) coding, and educating physicians about documentation and clinical pathways. The most common criticisms were that the reports were not timely and described death rates without providing practical information about the process of care. DISCUSSION: Although the 1996 CHOP reports and data were widely disseminated within hospitals, most reported uses did not directly affect the process of care for patients with acute myocardial infarction. This finding reflects two critical weaknesses of the project--nontimely data and lack of information about the process of care. Nevertheless, hospital quality managers recognize that public report cards are here to stay, and some carefully studied their outcomes data to identify areas for improvement.

Elective cervical discectomy in California: postoperative in-hospital complications and their risk factors.

STUDY DESIGN: A retrospective cohort study of short-term outcomes after elective cervical discectomy in California hospitals. OBJECTIVES: To compare the frequency of elective cervical discectomy across population strata, to determine the frequency of adverse outcomes in the early postoperative period, and to identify risk factors for such outcomes. SUMMARY OF BACKGROUND DATA: Previous cervical discectomy series have been too small to analyze risk factors for early complications, and have originated from centers that may not adequately represent the population. METHODS: Computerized hospital discharge abstracts were obtained from the California Office of Statewide Health Planning and Development. Inclusion and exclusion criteria were applied to identify 10,416 routine discectomies at 257 hospitals in 1990-1991. Several categories of postoperative complications were identified, along with inpatient deaths, early reoperations, and nursing home transfers. Logistic regression was used to estimate the independent effects of patient characteristics on short-term outcomes. RESULTS: After adjustment for age and gender, blacks were 51% and Hispanics were 24% as likely as whites to undergo elective cervical discectomy. Overall, 6.7% of patients had one or more reported postoperative complications: 1.8% had noninfectious surgical complications, 1.8% had infectious complications, 4.0% had other medical complications, and 0.35% had unplanned reoperations before discharge. Fourteen inpatient deaths were reported (0.13%). Congestive heart failure, alcohol/drug abuse, chronic lung disease, previous spine surgery, psychological disorders, and chronic musculoskeletal disorders were independently associated with postoperative complications. Even after adjustment, risk was higher with advancing age, higher among women than among men, and higher after posterior fusion than after discectomy without fusion. CONCLUSIONS: The ethnic disparity in cervical discectomy rates suggests overuse among whites or underuse among minority populations. The complication rates reported here are similar to those synthesized from previous literature, except that the lower incidence of neurologic complications reflects our inability to distinguish preoperative from postoperative deficits. Important comorbidities should be identified and treated, if appropriate, before cervical spine surgery.

The California Hospital Outcomes Project: using administrative data to compare hospital performance.

BACKGROUND: The California Hospital Outcomes Project was created by an act of the state legislature in 1991. The California Office of Statewide Health Planning and Development (OSHPD) publishes annual reports on risk-adjusted hospital outcomes for medical, surgical, and obstetric patients. These outcomes indicators were chosen: in-hospital mortality within 30 days (acute myocardial infarction [AMI]), reported post-operative complications (diskectomy, delivery), post-operative length of stay (diskectomy), and readmission within 6 weeks (delivery). Project reports are based on discharge abstracts submitted by hospitals and edited by OSHPD. For each outcome, two risk adjustment models were used to estimate expected and risk-adjusted hospital outcome rates, along with p values representing the likelihood that the observed number of adverse outcomes occurred by chance. RESULTS: The first hospital outcomes report was distributed to hospitals in June 1993 and released to the public in December 1993. The total number of hospitals labeled as "better than expected" was 14 for AMI, 5 for cervical diskectomy, and 25 for lumbar diskectomy. The second hospital outcomes report was distributed to hospitals in June 1995. RESPONSE AND CONCLUSIONS: Letters submitted for 168 hospitals in response to the 1993 report demonstrated that hospitals had studied and used project results to evaluate their coding practices and quality of care. Media coverage of the 1993 report was balanced but sometimes critical of OSHPD's failure to identify "worse" hospitals. In response to providers' concerns, OSHPD has undertaken a validation study to explore whether differences in coding, unmeasured risk factors, or processes of care explain the reported differences in risk-adjusted outcome rates.

Effect of platelet suppressant treatment with dipyridamole and aspirin on exercise performance and platelet survival time in coronary disease.

Platelets may contribute to the pathogenesis of atherosclerotic coronary artery disease (CAD), and platelet reactivity may be activated by exercise. Fourteen men with CAD participated in a double-blind, crossover study of aspirin (ASA), dipyridamole (DPY), ASA-DPY, and placebo. The ASA therapy increased platelet survival time (autologous labelling with 51Cr), but had no effect on either the duration of angina-limited treadmill exercise or the heart rate-systolic blood pressure product (x 10(-2)) at peak exercise. The combination DPY-ASA had a greater effect on platelet survival, but did not substantially increase the duration of exercise. Administration of DPY alone at a higher dosage increased the exercise duration and had a similar effect on platelet survival. At the time that control exercise was completed with the higher dosage of DPY, the rate-pressure product was decreased. The results suggest that DPY and ASA favorably alter the platelet survival in men with CAD, and that DPY, but not ASA, favorably alters exercise performance. Although ASA and ASA-DPY may alter platelet response to exercise, the effect is not shown in hemodynamic measurements during exercise. In higher dosages, DPY may be an effective coronary vasodilator for men with CAD.

Platelet suppressant therapy in patients with prosthetic cardiac valves. Relationship of clinical effectiveness to alteration of platelet survival time.

Platelet survival time (SURV) has correlated with thromboembolism in patients with prosthetic cardiac valves. Sulfinpyrazone increases SURV. SURV (autologous labeling with 51Chromium) was measured in 126 patients who had aortic or mitral valve replacement. These patients were followed prospectively. Ninety-four with shortened SURV received sulfinpyrazone; 32 with normal SURV were not treated with platelet suppressants. Eighty-seven patients were anticoagulated with warfarin--67 with shortened SURV and 20 with normal SURV. Eleven patients have had thromboembolism, and all had shortened SURV (2.4 +/- 0.08 days; average half-time +/- SEM; normal 3.7 +/- 0.03 days; n = 26) none had an increase of SURV with sulfinpyrazone (2.3 +/- 0.09 days). Of 83 patients with shortened SURV who did not have embolism, sulfinpyrazone increased SURV in 59 (71%) 2.6 +/- 0.05 to 2.9 +/- 0.06 days). Of 35 patients with shortened SURV who failed to increase SURV with sulfinpyrazone, 11 (31%) had embolism; none of 59 (0%) with an increase of SURV with sulfinpyrazone had thromboembolism. These results suggest that patients with thromboembolism after prosthetic cardiac valve replacement have shortened SURV and that patients treated with slufinpyrazone who have thromboembolism do not have an increased SURV.

Platelet survival time and thromboembolism in patients with mitral valve prolapse.

Thromboembolism (TE) occurs in about 20% of patients with rheumatic mitral valve disease, and platelet survival time in these patients has correlated with TE. In patients with mitral valve prolapse, TE appears to occur very infrequently. Platelet survival (autologous labeling with chromium-51) was performed in 26 patients with mitral prolapse. Five patients had a history of stroke, as well as normal cerebrovascular arteriography and shortened platelet survival (average half-time +/- SEM 2.3 +/- 0.18 days; normal half-time 3.7 +/- 0.03 days; n = 26; p less than 0.01). Platelet survival was shortened in seven of 21 patients without TE (33%) (3.3 +/- 0.06 days; p less than 0.01 vs patients with TE). In 138 patients with rheumatic heart disease, platelet survival was shortened in 40 of 41 (98%) with a history of TE (2.3 +/- 0.08 days) and in 76 of 97 (78%) without TE (2.9 +/- 0.07 days; p less than 0.001 vs patients with TE). In patients with mitral prolapse, sulfinpyrazone increased platelet survival (2.4 +/- 0.16 to 2.7 +/- 0.19 days; n = 7; p less than 0.05). Our results suggest that platelet survival time is shortened in patients with mitral prolapse and rheumatic heart disease who have had TE. Of those without TE there is an increased frequency of shortened platelet survival in patients with rheumatic heart disease (78%) compared with those with mitral prolapse (33%), consistent with the infrequency of TE in mitral prolapse.

Effects of dietary and pharmacologic alteration of serum lipids on platelet survival time.

Platelet survival time (SURV) (autologous labelling with 51Chromium) was shortened (3 +/- 0.03 days; average t 1/2 +/- SEM; normal t 1/2 3.7 +/- 0.03 days) in 88 out of 128 (69%) men with coronary disease. In 35 out of 47 men with hyperprebetalipoproteinemia, SURV was shortened (3 +/- 0.09 days) (74%). Of 30 men with hyperbetalipoproteinemia, SURV was shortened (2.5 +/- 0.10 days) in 26 (87%). Of 51 men without hyperlipoproteinemia, SURV was normal (3.3 +/- 0.10 days) in 24 (47%). Dietary alteration of serum triglyceride was undertaken in 12 men with hyperprebetalipoproteinemia, and in eight a decrease of triglyceride of more than 75 mg% was achieved (324 +/- 21-219 +/- 18 mg%; P less than 0.001) with an increase of SURV (2.2 +/- 0.11-2.8 +/- 0.13 days; P less than 0.001). In four, serum triglyceride increased by more than 75 mg% (279 +/- 14-451 +/- 28 mg%) and SURV decreased (2.7 +/- 0.16-2.3 +/- 0.21 days). Cholestyramine (16 g g.d.) and diet decreased serum cholesterol (348 +/- 7.6-319 +/- 6.3 mg%; P less than 0.001) in 15 men with hyperbetalipoproteinemia and SURV increased (2.3 +/- 0.08-2.7 +/- 0.07 days; P less than 0.001). Results suggest that SURV is shortened in men with coronary disease, particularly in those with hyperlipoproteinemia, and that alteration of triglyceride and cholesterol are associated with alteration of SURV.

Platelet-suppressant therapy in patients with coronary artery disease.

Platelets may contribute to the pathogenesis of atherosclerosis and to the complications of coronary atherosclerosis, acute myocardial infarction, unstable angina, and sudden cardiac death. In addition, platelets may contribute to saphenous vein aortocoronary graft occlusion. Of 104 men with coronary artery disease, platelet survival (SURV) (chromium51 labeling) was shortened in 68% (3.1+/-0.03 days [average+/-SEM]; normal, 3.7+/-0.03 days; P greater than .001). Three platelet-suppressant drugs, sulfinpyrazone, clofibrate, and dipyridamole increased SURV. Saphenous vein graft occlusion was associated with shortened SURV. Of 36 men with occlusion of at least one graft, SURV was shortened in 35 (2.5+/-0.08 days), whereas in 19 with all grafts open, SURV was shortened in six (3.5+/-0.10 days; P less than .01). These drugs increased SURV (2.3 +/- 0.08 to 2.7 +/- 0.11 days; P less than 0.1) and were associated with improved graft patency (four of 32 grafts after initial bypass vs 30 of 34 grafts open after second operation).

Abnormal platelet survival time in men with myocardial infarction and normal coronary arteriogram.

Platelet survival time was measured in eight men who had an acute transmural myocardial infarction and were subsequently found to have a normal coronary arteriogram. Platelet survival (chromium-51 labeling) was shortened in all men (2.4 +/- 0.11 days; average half-time +/- standard error of the mean) and different from that in eight age-matched normal men (3.7 +/- 0.08 days) (P less than 0.001). Three patients had recurrent venous thromboembolism and one had had iliofemoral arterial thromboembolism. Platelet survival was shortened (2.9 +/- 0.12 days) in 11 of 16 age-matched men with transmural infarction who had arteriographic evidence of coronary obstructive disease. These results suggest that platelet survival time is shortened in patients with infarction who subsequently are shown to have a normal coronary arteriogram and that arterial thrombosis may be responsible for the infarction.