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.

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.

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.

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.

Spinal cord degeneration in AIDS.

Ten months before his death, a 36-year-old homosexual man with AIDS developed progressive symmetric paraparesis with muscle wasting, paresthesias, reflex-uninhibited bladder function, and bowel incontinence. Neuropathologic postmortem examination revealed a symmetric degeneration of the lateral and anterior pyramidal tracts as well as the posterior columns. Scattered microglial nodules were present in the brain and spinal cord. The cause of this spinal cord complication remains uncertain. Possible etiologies of the demyelinating process include infectious, parainfectious, nutritional, paraneoplastic, and toxic causes.

Serum myoglobin determination: laboratory and clinical evaluation.

Quality assurance examination of a commercially available radioimmunoassay kit for determination of serum myoglobin level conformed the measurement to be accurate, precise, and reproducible under all assay performance variables. Initial clinical evaluation in patients admitted to the Coronary Care Unit revealed comparable diagnostic parameters and earlier detection when compared with the present standard indicator of myocardial necrosis, creatine phosphokinase MB isoenzyme. Interpretation that an elevated myoglobin reflects acute myocardial infarction should be made only in the appropriate clinical context.

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.

Evaluation of saphenous vein bypass surgery with multistage treadmill test and ventricular function studies.

The study includes 50 patients with severe, stable angina who have undergone the saphenous vein bypass operation. Patients were evaluated preoperatively and postoperatively with regard to exercise tolerance, incidence of stress-induced agina, ST-segment changes of ischemia, and ventricular function as indicated by stroke work index (LVSWI) and ejection fraction. Comparisons were made between patients with complete revascularization (CR) and patients with postoperative residual ischemia (RI). Results revealed that exercise duration improved significantly in both the CR and RI groups. In the CR group, angina and ischemic ST changes were completely eliminated. In the RI group, there was a 25 percent incidence of stress angina and a 50 percent incidence of ischemic ST-segment changes. In neither group was the ejection fraction significantly different from preoperative values. LVSWI decreased significantly in both groups postoperatively.

Elastase production in clinical isolates of Aspergillus.

Clinical isolates of Aspergillus species were tested, both retrospectively and prospectively, for elastase activity using rose bengal-elastin agar plates. Patient records were then reviewed to determine the clinical diagnosis including the presence or absence of aspergillosis. All isolates that caused invasive aspergillosis produced elastase, but not all isolates producing elastase were associated with invasive disease.

Inhibition of alpha-aminoadipate-semialdehyde dehydrogenase from Trichosporon adeninovorans by lysine and lysine analogues.

The alpha-aminoadipate-semialdehyde dehydrogenase (EC 1.2.1.31) of Trichosporon adeninovorans, an enzyme of lysine biosynthesis, was partially purified, some properties of the enzyme were studied and a novel regulatory pattern was found. The Km values of the enzyme were estimated to be 0.78 mM for alpha-aminoadipate, 1.0 mM for ATP, 0.23 mM for NADPH and 0.77 mM for MgCl2. It is demonstrated that the enzyme can be regulated by lysine and lysine analogues. L-Lysine (Ki of 0.09 mM), S-(beta-aminoethyl)-L-cysteine (Ki of 0.007 mM) and delta-hydroxylysine (Ki of 1.65 mM) inhibited the enzyme activity. The inhibition was competitive with respect to alpha-aminoadipate and non-competitive with respect to both ATP and NADPH.

Investigation of possible interaction between pinaverium bromide and digoxin.

A single-blind study was carried out in 25 patients, who were receiving maintenance therapy for congestive heart failure with digoxin, to investigate the effect on steady-state plasma digoxin levels of concomitant administration of the spasmolytic, pinaverium bromide (50 mg 3-times daily). Patients received pinaverium bromide for 12 days followed by placebo for a further 7 days. Assessment of the results in 21 patients showed no evidence of any statistically significant variations in plasma digoxin levels during either treatment period or in the clinical observations which might indicate drug interaction.

Paecilomyces variotii. An unusual cause of isolated sphenoid sinusitis.

Isolated fungal sphenoid sinusitis is an unusual head and neck infection. We describe the first reported case (to our knowledge) of Paecilomyces variotii sphenoid sinusitis. In addition, it represents one of the few reported cases of isolated fungal sphenoid sinusitis. Diagnosis and management of this condition are described. Aggressive surgical management is advocated when fungal sphenoid sinusitis is suspected.

Probe radiocardiography: validation of a technique to routinely determine left ventricular ejection fraction.

We investigated the probability of obtaining a valid radiocardiogram with the first commercially available cardiac probe and a peripheral injection of the radiopharmaceutical. Measurements of left ventricular ejection fraction (LVEF) were obtained in a series of 15 patients undergoing cardiac catheterization. Probe LVEF determinations using central, peripheral and rapid sequential injections correlated well with each other and with ventriculography (r = .88--.98). By documenting its accuracy and precision, this study confirms the validity of a new technique for measuring LVEF.

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.

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.

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.