Seed Predators, not Herbivores, Exert Natural Selection on Solidago spp. in an Urban Archipelago.

The effects of urbanization on biodiversity are well established, as a growing city will reduce the size and diversity of patches of native plants. Recolonization of old patches and discovery of new ones by arthropod herbivores should occur as predicted by island biogeography theory. Although colonization represents an increase in biodiversity, such arrivals may exert new forms of natural selection on plants through herbivory and seed predation. Using a single species of old-field aster (Solidago altissima L.), we found that the level of natural selection by seed predators and herbivores follows patterns of island biogeography, with lower amounts of damage on smaller islands, where there are fewer species, and hypothetically smaller populations of arthropods. We also found that in an urban system, levels of herbivory are far below the tolerance levels of Solidago, and that seed predators are likely to be the only arthropod to cause reduced fitness. The pattern seen also implies that as a patch of Solidago grows through clonal expansion, it will come under higher selective pressure.

Arxula adeninivorans recombinant adenine deaminase and its application in the production of food with low purine content.

AIMS: Construction of a transgenic Arxula adeninivorans strain that produces a high concentration of adenine deaminase and investigation into the application of the enzyme in the production of food with low purine content. METHODS AND RESULTS: The A. adeninivorans AADA gene, encoding adenine deaminase, was expressed in this yeast under the control of the strong inducible nitrite reductase promoter using the Xplor(®) 2 transformation/expression platform. The recombinant enzyme was biochemically characterized and was found to have a pH range of 5.5-7.5 and temperature range of 34-46 °C with medium thermostability. A beef broth was treated with the purified enzyme resulting in the concentration of adenine decreasing from 70.4 to 0.4 mg l(-1). CONCLUSIONS: It was shown that the production of adenine deaminase by A. adeninivorans can be increased and that the recombinant adenine deaminase can be used to lower the adenine content in the food. SIGNIFICANCE AND IMPACT OF THE STUDY: Adenine deaminase is one component of an enzymatic system that can reduce the production of uric acid from food constituents. This study gives details on the expression, characterization and application of the enzyme and thus provides evidence that supports the further development of the system.

Arxula adeninivorans xanthine oxidoreductase and its application in the production of food with low purine content.

AIMS: Isolation and characterization of xanthine oxidoreductase and its application in the production of food with low purine content. METHODS AND RESULTS: The A. adeninivorans xanthine oxidoreductase is an inducible enzyme. The best inducers were identified by enzyme activity tests and real-time PCR and used to produce large amounts of the protein. Xanthine oxidoreductase was partially purified and biochemically characterized, showing pH and temperature optimum of 8·5 and 43°C, respectively. The enzyme decreased xanthine and hypoxanthine concentrations in yeast extract and was active simultaneously with other purine-degrading enzymes so that all of the substrates for uric acid production were reduced in a single step. CONCLUSIONS: It was shown that induced A. adeninivorans can produce sufficient amount of xanthine dehydrogenase and that the enzyme is able to reduce xanthine and hypoxanthine content in food, and when used in conjunction with other enzymes of the pathway, uric acid concentration is significantly reduced. SIGNIFICANCE AND IMPACT OF THE STUDY: Reduction in dietary purines is recommended to people suffering from hyperuricemia. Elimination of most purine-rich foods may affect balanced nutrition. Food with lowered purine concentration will assist in controlling the disease. This study is a continuation of previous studies that characterized and overexpressed other enzymes of the purine degradation pathway.

Neuro-QOL: brief measures of health-related quality of life for clinical research in neurology.

OBJECTIVE: To address the need for brief, reliable, valid, and standardized quality of life (QOL) assessment applicable across neurologic conditions. METHODS: Drawing from larger calibrated item banks, we developed short measures (8-9 items each) of 13 different QOL domains across physical, mental, and social health and evaluated their validity and reliability. Three samples were utilized during short form development: general population (Internet-based, n = 2,113); clinical panel (Internet-based, n = 553); and clinical outpatient (clinic-based, n = 581). All short forms are expressed as T scores with a mean of 50 and SD of 10. RESULTS: Internal consistency (Cronbach α) of the 13 short forms ranged from 0.85 to 0.97. Correlations between short form and full-length item bank scores ranged from 0.88 to 0.99 (0.82-0.96 after removing common items from banks). Online respondents were asked whether they had any of 19 different chronic health conditions, and whether or not those reported conditions interfered with ability to function normally. All short forms, across physical, mental, and social health, were able to separate people who reported no health condition from those who reported 1-2 or 3 or more. In addition, scores on all 13 domains were worse for people who acknowledged being limited by the health conditions they reported, compared to those who reported conditions but were not limited by them. CONCLUSION: These 13 brief measures of self-reported QOL are reliable and show preliminary evidence of concurrent validity inasmuch as they differentiate people based upon number of reported health conditions and whether those reported conditions impede normal function.

Paget's disease of bone: the skeletal distribution, complications and quality of life as perceived by patients.

CONTEXT: Paget's disease of bone (PDB) is a focal disorder of bone metabolism with overgrowth of affected bone resulting in the skeletal complications of this disease. OBJECTIVE: This study examines what patients know about the skeletal distribution of their PDB, and correlates this with their reports of complications and quality of life. DESIGN: The New England Registry for PDB (NRPD) is a voluntary registry with a questionnaire linked to a radiographic database. Data were collected by mail beginning in 2001. SETTING: Ambulatory population. PATIENTS: Any patient with PDB living in New England was eligible to enroll; 285 elected to participate, mean age 73.2 years. MAIN OUTCOME MEASURES: Patients were asked what bones were affected by PDB, and whether they suffered complications from PDB. Radiographic studies were sought to corroborate their responses. An SF-12 was administered. RESULTS: Compared to the general population, they reported substantially lower levels of physical health (Physical Component Score (PCS) mean=40), and slightly better mental health (Mental Component Score (MCS) mean=52). There were more instances of agreement on disease presence and fewer instances on disagreement (p=0.001). Radiographic studies supported the presence of a complication from PDB when deformity, fracture and joint replacement had occurred, but were less correlative when headache or hearing loss was reported. CONCLUSIONS: Most patients with PDB are aware of the skeletal distribution of their disease; there is a reasonable correlate between complications ascribed to PDB and the presence of PDB on the radiograph except when headache or hearing loss is reported.

Novel metabolic routes during the oxidation of hydroxylated aromatic acids by the yeast Arxula adeninivorans.

AIM: To complete our study on tannin degradation via gallic acid by the biotechnologically interesting yeast Arxula adeninivorans as well as to characterize new degradation pathways of hydroxylated aromatic acids. METHODS AND RESULTS: With glucose-grown cells of A. adeninivorans, transformation experiments with hydroxylated derivatives of benzoic acid were carried out. The 12 metabolites were analysed and identified by high performance liquid chromatography and GC/MS. The yeast is able to transform the derivatives by oxidative and nonoxidative decarboxylation as well as by methoxylation. The products of nonoxidative decarboxylation of protocatechuate and gallic acid are substrates for further ring fission. CONCLUSION: Whereas other organisms use only one route of transformation, A. adeninivorans is able to carry out three different pathways (oxidative, nonoxidative decarboxylation and methoxylation) on one hydroxylated aromatic acid. The determination of the KM-values for protocatechuate and gallic acid in crude extracts of cells of A. adeninivorans cultivated with protocatechuate and gallic acid, respectively, suggests that the decarboxylation of protocatechuate and gallic acid may be catalysed by the same enzyme. SIGNIFICANCE AND IMPACT OF THE STUDY: This transformation pathway of protocatechuate and gallic acid via nonoxidative decarboxylation up to ring fission is novel and has not been described so far. This is also the first report of nonoxidative decarboxylation of gallic acid by a eukaryotic micro-organism.

[Relapse rate within 6 months after successful ECT: a naturalistic prospective peer- and self-assessment analysis]. / Rückfallraten innerhalb von 6 Monaten nach erfolgreicher EKT--Eine naturalistische prospektive Fremd- und Selbstbeurteilungsanalyse.

BACKGROUND: Up to 100% relapse rate after successful electroconvulsive therapy (ECT) poses a challenge for patients and psychiatrists. The aim of the study was to evaluate the outcome of patients affected by major depression after the successful course of acute ECT. METHODS: 84 patients recruited in a randomized double blind multicenter study designed to investigate the optimal stimulation placement in acute ECT had a follow up under naturalistic conditions between the 5th and 7th month. Outcome, maintenance therapy and patients; attitude were evaluated with semi structured questionnaires by patients and the study raters. RESULTS: 82.14% (68/84) questionnaires of the patients and 83.3% (70/84) of the rater were returned. 98% of the patients had at least one antidepressant; only in 23% (20/68) lithium was prescribed. 35% (7/20) of the patients with lithium and 57% (16/28) without lithium had a relapse within the first 6 months (OR 0.6) in a median of 2.5 months. Only one institution offered maintenance ECT in 8.3% (7/84) patients. For 52.2% of the patients ECT was a helpful treatment an 49.3% would recommend the therapy to their relatives. The vast majority (59.4%) wishes a better information about the ECT and 21.4% feel frightening about the therapy. CONCLUSIONS: The results show a high relapse rate and highlight the meaning of maintenance medication especially for a lithium combination therapy, as stated before. In regard to the subjective sensation the patients claim a better education about the ECT and anyway one of four patients feel frightening about the therapy.

Analysis of patient and proxy ratings on the Dysexecutive Questionnaire: an application of Rasch analysis.

BACKGROUND: We provide an alternate method of analysing self-report and proxy-report data on subjective complaints of dysexecutive symptoms among a group of patients with traumatic brain injury. OBJECTIVE: The purpose of this study was to examine differences in the ratings of patients and proxies on a measure of the dysexecutive syndrome and further explore the insight impairment problem in patients with traumatic brain injury. METHODS: Rasch analysis was conducted on the ratings of the Dysexecutive Questionnaire (DEX) by a sample of patients and their proxies. RESULTS: While the average scores based on patient and proxy ratings were approximately the same (mean patient raw score = 30.12 and mean proxy raw score = 31.32), differential item functioning was found in five DEX items. As a result, the relationship between measures obtained from patient and proxy ratings was only in the moderate range (intraclass correlation = 0.46). CONCLUSIONS: Identification of differential item functioning in five of the 20 DEX items reflected the different perspectives of patients and their proxies in reporting the frequency of dysexecutive behaviour and suggests that these ratings are not interchangeable.

Equating EORTC QLQ-C30 and FACT-G scores and its use in oncological research.

OBJECTIVE: To investigate the equivalence of the European Organization for Research and Treatment of Cancer Core Questionnaire (EORTC QLQ-C30) and the Functional Assessment for Cancer Therapy-General (FACT-G) on the basis of corresponding subscales, and where appropriate to derive a scheme for converting QLQ-C30 scores into FACT-G scores and vice versa for use in oncological research. METHOD: A calibration sample of 737 cancer patients (mean age 51.4+/-7.6 (SD), 63% female, 25% with current chemotherapy) who filled in both quality of life (QOL) questionnaires was used. Both classical test theory and the Rasch measurement model were applied. RESULTS: Three of the four subscales common to both QOL instruments (physical, emotional, functional) proved suitable for equating (acceptable inter-correlations of corresponding subscales physical (r=0.77), emotional domain (r=0.60) role/functional (r=0.63) relative to their internal consistency, sufficient unidimensionality of pooled subscales, satisfactory fit to the Rasch model). Conversion tables for these subscales were generated. CONCLUSIONS: The conversion tables developed in this study (physical, emotional and functional/role domain) appear promising for the comparison between EORTC QLQ-C30 and FACT-G scores of patient samples.

Stroke Impact Scale-16: A brief assessment of physical function.

OBJECTIVES: To 1) develop a short instrument (Stroke Impact Scale-16 [SIS-16]) to assess physical function in patients with stroke at approximately 1 to 3 months poststroke using items from the composite physical domain of the Stroke Impact Scale (SIS) version 3.0, and 2) compare the SIS-16 and a commonly used disability measure, the Barthel Index (BI), in terms of their ability to discriminate disability. METHODS: A total of 621 subjects enrolled in the GAIN Americas randomized stroke trial were included in this study. Rasch analysis, which models the probability of a subject's response to an item using both subject ability and item difficulty, was used to construct the SIS-16, describe its properties, and compare its ordering and range of item difficulties to those of the BI. Box plots and analysis of variance were used to examine differences in BI and SIS-16 scores across modified Rankin categories. RESULTS: The study sample had an average age of 68 +/- 12.4 years and 56% were men. Stroke diagnoses were classified as minor in 91 patients (NIH Stroke Scale score [NIHSS] 0 to 5), moderate in 304 (NIHSS 6 to 13), and major in 226 (NIHSS >/= 14). Twelve of the original 28 items in the SIS version 3.0 composite physical domain were eliminated to produce the SIS-16, with a minimal loss of reliability. As compared to the BI, the SIS-16 contains more difficult items that can differentiate patients with less severe limitations, and therefore has less pronounced ceiling effects. SIS-16 scores were significantly different across Rankin levels 0 to 1, 2, 3, 4, and 5, whereas BI was significantly different only across Rankin levels 0 to 2, 3, 4, and 5. CONCLUSION: Compared to the BI, the SIS-16 is an excellent collection of items suitable for assessing a wide range of physical function limitations of patients with stroke at 1 to 3 months poststroke. Because of a less pronounced ceiling effect, the SIS-16 can differentiate lower levels of disability as compared to the BI.

Development and measurement properties of the Orthotics and Prosthetics Users' Survey (OPUS): a comprehensive set of clinical outcome instruments.

The need to measure and evaluate orthotics and prosthetics (O&P) practice has received growing recognition in the past several years. Reliable and valid self-report instruments are needed that can help facilities evaluate patient outcomes. The objective of this project was to develop a set of self-report instruments that assess functional status, quality of life, and satisfaction with devices and services that can be used in an orthotics and prosthetics clinic. Selecting items from a variety of existing instruments, the authors developed and revised four instruments that differentiate patients with varying levels of lower limb function, quality of life, and satisfaction with devices and services. Evidence of construct validity is provided by hierarchies of item difficulty that are consistent with clinical experience. For example, with the lower limb function instrument, running one block was much more difficult than walking indoors. The instruments demonstrate adequate internal consistency (0.88 for lower limb function, 0.88 for quality of life, 0.74 for service satisfaction, 0.78 for device satisfaction). The next steps in their research programme are to evaluate sensitivity and construct validity. The Orthotics and Prosthetics Users' Survey (OPUS) is a promising self-report instrument which may, with further development, allow orthotic and prosthetic practitioners to evaluate the quality and effectiveness of their services as required by accreditation standards such as those of the American Board for Certification in Orthotics and Prosthetics that mandate quality assessment.

Outcomes of cardiopulmonary arrest in an acute rehabilitation setting.

OBJECTIVE: Fifty consecutive cases of cardiopulmonary arrest with administration of cardiopulmonary resuscitation (CPR) during a 6-yr period at a freestanding academic acute rehabilitation hospital were identified. DESIGN: Medical records of 49 patients were available for review. Outcomes of survival of arrest, survival to 24 hr postarrest, survival to discharge from the hospital were determined, and chi2 or Fisher's exact tests were performed to investigate relationships between survival and admission functional status, age, gender, and medical comorbidities. RESULTS: Forty-three percent of patients survived the initial arrest, 37% survived to 24 hr post-CPR, and 18% survived to hospital discharge. We were unable to identify any statistically significant predictors of survival post-CPR. Six of the nine survivors returned to the acute rehabilitation setting after cardiopulmonary arrest, and five of these patients made significant functional gains. CONCLUSIONS: Outcomes after CPR in patients undergoing acute rehabilitation in one setting were not significantly different from those reported for patients in other healthcare settings. These data may be used by healthcare professionals to enhance discussions concerning advance healthcare planning (including resuscitation plans) with patients and families. Larger studies are needed to clarify the prognostic role of prior functional status in predicting CPR outcomes, particularly in the context of various diagnostic categories and age groups.

Age and history of cardiac disease as risk factors for cardiac complications after peripheral vascular surgery in diabetic patients.

OBJECTIVE: To examine the relationship of age and clinical factors to postoperative cardiovascular events in a cohort of diabetic patients undergoing peripheral vascular surgery. PATIENTS AND METHODS: In this cohort study, 316 diabetic patients were followed up prospectively after femoral-to-distal artery bypass surgery. The major end points of the study were all-cause mortality and cardiac morbidity (cardiac events defined as nonfatal myocardial infarction, unstable angina, and congestive heart failure). RESULTS: The overall postoperative cardiac event rate was 17.1% (54/316), with a 7.6% (24/316) rate of postoperative death or nonfatal myocardial infarction. Older diabetic patients (> or = 65 years) had a complication rate of 19.9% (43/216) compared with an 11.0% (11/100) complication rate in younger diabetic patients (< 65 years) (P = .02). Younger diabetic patients with a clinical history of coronary artery disease had an event rate of 18.2% (39/216) compared with an event rate of 2.4% (1/42) in younger diabetic patients without known cardiac disease (P = .02). In contrast, event rates were similar (20.7% [150/208] vs 18.2% [66/108]) in older diabetic patients with or without prior evidence of cardiac disease. CONCLUSION: Advanced age and clinical evidence of coronary artery disease are important determinants of postoperative outcome in diabetic patients undergoing peripheral vascular surgery.

Partial credit model and pivot anchoring.

This article contains information on the Rasch measurement partial credit model: what it is, how it differs from other Rasch models, when to use it, and how to use it. The calibration of instruments with increasingly complex items is described, starting with dichotomous items and moving on to polychotomous items using a single rating scale, and mixed polychotomous items using multiple rating scales, and instruments in which each item has its own rating scale. It also introduces a procedure for aligning rating scale categories to be used when more than one rating scale is used in a single instrument. Pivot anchoring is defined and an illustration of its use with the mental health scale of the SF-36 that contains positive and negative worded items is provided. It finally describes the effect of pivot anchoring on step calibrations, the item hierarchy, and person measures.

Prophylactic amrinone for weaning from cardiopulmonary bypass.

This prospective, randomised, double-blind, controlled clinical study was performed at a single tertiary referral centre to test the hypothesis that the prophylactic administration of amrinone before separation of a patient from cardiopulmonary bypass decreases the incidence of failure to wean, and to identify those patients who could be predicted to benefit from such pre-emptive management. Two hundred and thirty-four patients, scheduled to undergo elective cardiac surgery, were randomly allocated to receive either a bolus dose of 1.5 mg x kg(-1) amrinone over 15 min, followed by an infusion of 10 microg x kg(-1) x min(-1), or a bolus of placebo of equal volume followed by an infusion of placebo. Treatment with amrinone or placebo was initiated upon release of the aortic cross-clamp, before weaning from cardiopulmonary bypass. Anaesthetic technique, monitoring and myocardial preservation methods were standardised for both groups. Significantly fewer patients failed to wean in the group that received prophylactic amrinone than in the control group (7 vs. 21%, p = 0.002). Amrinone improved weaning success regardless of left ventricular ejection fraction, although this benefit was statistically significant only in the group with left ventricular ejection fractions > 55%. Of the 32 patients who failed to wean from cardiopulmonary bypass, 14 had normal pre-operative left ventricular ejection fractions.

Measurement properties of the Galveston Orientation and Amnesia Test (GOAT) and improvement patterns during inpatient rehabilitation.

OBJECTIVES: To determine the measurement properties of the Galveston Orientation and Amnesia Test (GOAT) using the Rasch model and rating scale analysis (RSA). DESIGN: Calibration of data collected weekly during rehabilitation. SETTING: Six inpatient rehabilitation facilities. PARTICIPANTS: 77 patients admitted for their first rehabilitation after traumatic brain injury. RESULTS: Rescoring the items as dichotomies, three strata of posttraumatic amnesia (PTA) were identified. All items cohered to define a single construct and the item hierarchy confirmed their hypothesized ordering. CONCLUSIONS: Equal-interval measures of PTA were developed that exhibited good reliability and validity. A self-scoring key was developed to more efficiently assess PTA.

Rating scale analysis of the Agitated Behavior Scale.

OBJECTIVE: Evaluate the measurement properties of the Agitated Behavior Scale (ABS) using rating scale analysis. SAMPLES: Sample 1: 900 observations of 100 individuals with traumatic brain injury; Sample 2: 204 observations of 102 persons with dementia; Sample 3: 241 observations of 6 individuals with anoxia. RESULTS: The calibration indicated that the rating scale was used as intended. The hierarchies of item difficulty were similar across samples. Person and item separation values were within the acceptable range for the TBI sample. Generally, the items work well together, however 3 items misfit the measurement model moderately. CONCLUSIONS: Agitation as measured by the ABS is best represented as a unitary construct. Results provide additional support for the reliability and validity of the ABS.

Rating scale analysis of the Neurobehavioral Cognitive Status Examination.

OBJECTIVE: Evaluate the measurement properties of the Neurobehavioral Cognitive Status Examination (NCSE) using rating scale analysis. DESIGN: Calibration of item responses collected as part of a study examining characteristics of case-management programs and treatment outcomes. SETTING: Three outpatient rehabilitation facilities. PARTICIPANTS: Convenience sample of 186 community-dwelling adults with TBI. RESULTS: Several rating scale analyses were performed to construct a unidimensional measure. Deletion of easy and misfitting items created a better targeted test (generated more spread among individuals) without increased error. CONCLUSIONS: If used with a community-based sample, three strata can be differentiated despite a skewed distribution. Recommended applications are with samples with considerably more cognitive impairment.

Relationship between cognitive impairments and rated activity restrictions in stroke patients.

OBJECTIVE: To investigate the relationship between cognitive impairments and rated activity restrictions. DESIGN: Comparison of neuropsychological tests and activity questionnaires. Activity ratings were made by staff and stroke patients. SETTING: Two neurological rehabilitation hospitals. PARTICIPANTS: Eighty-seven stroke patients. RESULTS: Moderately high correlations were found between cognitive test scores and activity ratings made by staff members. In contrast, correlations between ratings made by patients and cognitive tests were much lower. There was also little agreement between the staffs' ratings and the patients' own ratings. Multiple regression analyses indicate that cognitive impairments account for 28.9% of the variance in the activity rating made by the staff members. The coefficient of determination was slightly higher when age, time since onset of illness, and depression scores were included as predictors. CONCLUSIONS: These findings provide partial support for a hierarchical structure of the "International Classification of Impairment, Activities and Participation" model of the World Health Organization.

Medical complications during acute rehabilitation following spinal cord injury--current experience of the Model Systems.

OBJECTIVES: To examine the frequency of common secondary medical complications during acute rehabilitation in persons with new spinal cord injury (SCI). DESIGN: Survey and analysis of data in the National SCI Statistical Center (NSCISC) database. SETTING: Eighteen Model System SCI Centers located in urban, public medical centers around the United States. SUBJECTS: A total of 1,649 persons with new SCI entered into the NSCISC database between 1996 and mid-1998. RESULTS: Since 1992, the number of days from injury to admission to rehabilitation has steadily decreased, resulting in the increased potential to develop common secondary medical complications during rehabilitation hospitalization. Pressure ulcers occur with high frequency and were found to have developed in 23.7% of patients during rehabilitation. In addition, autonomic dysreflexia and atelectasis/pneumonia also occur with relative frequency during rehabilitation. Conversely, deep vein thrombosis and pulmonary embolism have decreased, most likely because of greater awareness of their potential to develop, as well as improved methods of prophylaxis. Cardiopulmonary arrest and gastrointestinal hemorrhage occur with relatively small frequency. The frequency of renal complications is difficult to gauge because of the decreasing number of patients who have any renal testing performed during rehabilitation hospitalization. CONCLUSION: The continued declining lengths of acute care hospitalization after SCI have resulted in the occurrence in the rehabilitation setting of medical complications that were previously seen in acute care. Greater awareness and attention to these conditions are necessary to reduce their occurrence, so that obstacles to recovery and functional improvement after SCI are minimized.