Characterization of xanthine oxidase from Cellulosimicrobium funkei possessing hypoxanthine-metabolizing activity

AIMS

Purine-degrading enzymes are favourable as medications and diagnostic tools for hyperuricemia. This study aimed to characterize enzymes isolated from micro-organisms, which may be useful for developing a new prophylaxis for hyperuricemia.

METHODS AND RESULTS

Cellulosimicrobium funkei A153 was found to be a good catalyst for hypoxanthine degradation and could oxidize hypoxanthine to xanthine and further to uric acid. The enzyme catalysing this oxidation was purified, and its partial amino acid sequences were examined. Based on this information and genome sequencing results, this xanthine dehydrogenase family protein was cloned and expressed in Rhodococcus erythropolis L88. The recombinant enzyme with a His-tag was characterized. The enzyme was a xanthine oxidase as it could utilize molecular oxygen as an electron acceptor. It was stable under 50°C and exhibited maximum activity at pH 7·0. The k_cat , K_m and k_cat /K_m values for xanthine were 1·4 s^-1 , 0·22 mmol l^-1 and 6·4 s^-1  mmol^-1  l, respectively.

CONCLUSIONS

Xanthine oxidase is favourable for hyperuricemia medication because it oxidizes hypoxanthine, an easily adsorbed purine, to xanthine and further to uric acid, which are hardly adsorbed purines.

SIGNIFICANCE AND IMPACT OF THE STUDY

The enzyme is useful for decreasing serum uric acid levels via conversion of easily absorbed purines to hardly absorbed purines in the intestine. Enzymes from micro-organisms may be used as a novel prophylaxis for hyperuricemia.

Comparative Effectiveness of Coalitions Versus Technical Assistance for Depression Quality Improvement in Persons with Multiple Chronic Conditions

Significance

Prior research suggests that Community Engagement and Planning (CEP) for coalition support compared with Resources for Services (RS) for program technical assistance to implement depression quality improvement programs improves 6- and 12-month client mental-health related quality of life (MHRQL); however, effects for clients with multiple chronic medical conditions (MCC) are unknown.

Objective

To explore effectiveness of CEP vs RS in MCC and non-MCC subgroups.

Design

Secondary analyses of a cluster-randomized trial.

Setting

93 health care and community-based programs in two neighborhoods.

Participants

Of 4,440 clients screened, 1,322 depressed (Patient Health Questionnaire, PHQ8) provided contact information, 1,246 enrolled and 1,018 (548 with ≥3 MCC) completed baseline, 6- or 12-month surveys.

Intervention

CEP or RS for implementing depression quality improvement programs.

Outcomes and Analyses

Primary: depression (PHQ9 <10), poor MHRQL (Short Form Health Survey, SF-12<40); Secondary: mental wellness, good physical health, behavioral health hospitalization, chronic homelessness risk, work/workloss days, services use at 6 and 12 months. End-point regressions were used to estimate intervention effects on outcomes for subgroups with ≥3 MCC, non-MCC, and intervention-by-MCC interactions (exploratory).

Results

Among MCC clients at 6 months, CEP vs RS lowered likelihoods of depression and poor MHRQL; increased likelihood of mental wellness; reduced work-loss days among employed and likelihoods of ≥4 behavioral-health hospitalization nights and chronic homelessness risk, while increasing faith-based and park community center depression services; and at 12 months, likelihood of good physical health and park community center depression services use (each P<.05). There were no significant interactions or primary outcome effects for non-MCC.

Conclusions

CEP was more effective than RS in improving 6-month primary outcomes among depressed MCC clients, without significant interactions.

Comparative Effectiveness of Coalitions Versus Technical Assistance for Depression Quality Improvement in Persons with Multiple Chronic Conditions

SIGNIFICANCE

Prior research suggests that Community Engagement and Planning (CEP) for coalition support compared with Resources for Services (RS) for program technical assistance to implement depression quality improvement programs improves 6- and 12-month client mental-health related quality of life (MHRQL); however, effects for clients with multiple chronic medical conditions (MCC) are unknown.

OBJECTIVE

To explore effectiveness of CEP vs RS in MCC and non-MCC subgroups.

DESIGN

Secondary analyses of a cluster-randomized trial.

SETTING

93 health care and community-based programs in two neighborhoods.

PARTICIPANTS

Of 4,440 clients screened, 1,322 depressed (Patient Health Questionnaire, PHQ8) provided contact information, 1,246 enrolled and 1,018 (548 with ≥3 MCC) completed baseline, 6- or 12-month surveys.

INTERVENTION

CEP or RS for implementing depression quality improvement programs.

OUTCOMES AND ANALYSES

Primary: depression (PHQ9 <10), poor MHRQL (Short Form Health Survey, SF-12<40); Secondary: mental wellness, good physical health, behavioral health hospitalization, chronic homelessness risk, work/workloss days, services use at 6 and 12 months. End-point regressions were used to estimate intervention effects on outcomes for subgroups with ≥3 MCC, non-MCC, and intervention-by-MCC interactions (exploratory).

RESULTS

Among MCC clients at 6 months, CEP vs RS lowered likelihoods of depression and poor MHRQL; increased likelihood of mental wellness; reduced work-loss days among employed and likelihoods of ≥4 behavioral-health hospitalization nights and chronic homelessness risk, while increasing faith-based and park community center depression services; and at 12 months, likelihood of good physical health and park community center depression services use (each P<.05). There were no significant interactions or primary outcome effects for non-MCC.

CONCLUSIONS

CEP was more effective than RS in improving 6-month primary outcomes among depressed MCC clients, without significant interactions.

A Community-Partnered, Participatory, Cluster-Randomized Study of Depression Care Quality Improvement: Three-Year Outcomes

OBJECTIVE

Community Partners in Care, a community-partnered, cluster-randomized trial with depressed clients from 93 Los Angeles health and community programs, examined the added value of a community coalition approach (Community Engagement and Planning [CEP]) versus individual program technical assistance (Resources for Services [RS]) for implementing depression quality improvement in underserved communities. CEP was more effective than RS in improving mental health-related quality of life, reducing behavioral health hospitalizations, and shifting services toward community-based programs at six months. At 12 months, continued evidence of improvement was found. This study examined three-year outcomes.

METHODS

Among 1,004 participants with depression who were eligible for three-year follow-up, 600 participants from 89 programs completed surveys. Multiple regression analyses estimated intervention effects on poor mental health-related quality of life and depression, physical health-related quality of life, behavioral health hospital nights, and use of services.

RESULTS

At three years, no differences were found in the effects of CEP versus RS on depression or mental health-related quality of life, but CEP had modest effects in improving physical health-related quality of life and reducing behavioral health hospital nights, and CEP participants had more social- and community-sector depression visits and greater use of mood stabilizers. Sensitivity analyses with longitudinal modeling reproduced these findings but found no significant differences between groups in change from baseline to three years.

CONCLUSIONS

At three years, CEP and RS did not have differential effects on primary mental health outcomes, but CEP participants had modest improvements in physical health and fewer behavioral health hospital nights.

Comparative Effectiveness of Two Models of Depression Services Quality Improvement in Health and Community Sectors

OBJECTIVE

The effectiveness of community coalition building and program technical assistance was compared in implementation of collaborative care for depression among health care and community sector clients.

METHODS

In under-resourced communities, within 93 programs randomly assigned to coalition building (Community Engagement and Planning) or program technical assistance (Resources for Services) models, 1,018 clients completed surveys at baseline and at six, 12, or 36 months. Regression analysis was used to estimate intervention effects and intervention-by-sector interaction effects on depression, mental health-related quality of life, and community-prioritized outcomes and on services use.

RESULTS

For outcomes, there were few significant intervention-by-sector interactions, and stratified findings suggested benefits of coalition building in both sectors. For services use, at 36 months, increases were found for coalition building in primary care visits, self-help visits, and appropriate treatment for community clients and in community-based services use for health care clients.

CONCLUSIONS

Relative to program technical assistance, community coalition building benefited clients across sectors and shifted long-term utilization across sectors.

Centrifugal microfluidic platform for single-cell level cardiomyocyte-based drug profiling and screening

Drug screening and profiling is an important phase in drug discovery, development, and marketing. However, some profiling tests are not routinely done because of the needed additional technical skills and costly maintenance, which leads to cases of unexpected side effects or adverse drug reactions (ADRs). This study presents the design and operation of a microfluidic chip for single-cell level drug screening and profiling as an alternative platform for this purpose. Centrifugation was utilized to trap isolated single and groups of primary cultured neonatal rat cardiomyocytes in the same chip. In the off-spin operation of the chip, the cells can be observed under a microscope and movies of the beat motion can be recorded. The beat profiles of the cells were generated by image correlation analysis of the recorded video to study the contractile characteristics (beating rate, beating strength, and inter-beat duration). By utilizing this non-invasive tool, long term continuous monitoring, right after trapping, was made possible and cell growth and dynamics were successfully observed in the chip. Media and liquid replacement does not require further centrifugation but instead utilizes capillary flow only. The effect of carbachol (100 μM) and isoproterenol (4 μg mL(-1)) on single cells and groups of cells was demonstrated and the feature for immunostaining (β-actin) applicability of the chip was revealed. Furthermore, these findings can be helpful for the headway of non-invasive profiling of cardiomyocytes and for future chip design and operation of high-throughput lab-on-a-chip devices.

An optical spectrum of the afterglow of a γ-ray burst at a redshift of z = 6.295

The prompt gamma-ray emission from gamma-ray bursts (GRBs) should be detectable out to distances of z > 10 (ref. 1), and should therefore provide an excellent probe of the evolution of cosmic star formation, reionization of the intergalactic medium, and the metal enrichment history of the Universe. Hitherto, the highest measured redshift for a GRB has been z = 4.50 (ref. 5). Here we report the optical spectrum of the afterglow of GRB 050904 obtained 3.4 days after the burst; the spectrum shows a clear continuum at the long-wavelength end of the spectrum with a sharp cut-off at around 9,000 A due to Lyman alpha absorption at z approximately 6.3 (with a damping wing). A system of absorption lines of heavy elements at z = 6.295 +/- 0.002 was also detected, yielding the precise measurement of the redshift. The Si ii fine-structure lines suggest a dense, metal-enriched environment around the progenitor of the GRB.

The spin temperature of NH3 in Comet C/1999S4 (LINEAR)

A high-dispersion spectrum of Comet C/1999S4 (LINEAR) was obtained in the optical region with the high-dispersion spectrograph on the Subaru telescope when the comet was 0.863 astronomical units from the Sun before its disintegration. We obtained high signal-to-noise ratio emission lines of the cometary NH2 bands from which an ortho-to-para ratio (OPR) of 3.33 +/- 0.07 was derived on the basis of a fluorescence excitation model. Assuming that cometary NH2 mainly originates from ammonia through photodissociation, the derived OPR of NH2 molecules should reflect that of ammonia, which provides information on the environment of molecular formation or condensation and of the thermal history of cometary ices. Assuming that the OPR of ammonia in comets was unchanged in the nucleus, the derived spin temperature of ammonia (28 +/- 2 kelvin) suggests that a formation region of the cometary ammonia ice was between the orbit of Saturn and that of Uranus in the solar nebula.

Detection of Lead in the Carbon-rich, Very Metal-poor Star LP 625-44: A Strong Constraint on s-Process Nucleosynthesis at Low Metallicity

We report the detection of the Pb i lambda4057.8 line in the very metal-poor (&sqbl0;Fe&solm0;H&sqbr0;=-2.7), carbon-rich star, LP 625-44. We determine the abundance of Pb (&sqbl0;Pb&solm0;Fe&sqbr0;=2.65) and 15 other neutron-capture elements. The abundance pattern between Ba and Pb agrees well with a scaled solar system s-process component, while the lighter elements (Sr-Zr) are less abundant than Ba. The enhancement of s-process elements is interpreted as a result of mass transfer in a binary system from a previous asymptotic giant branch (AGB) companion, an interpretation strongly supported by radial velocity variations of this system. The detection of Pb makes it possible, for the first time, to compare model predictions of s-process nucleosynthesis in AGB stars with observations of elements between Sr and Pb. The Pb abundance is significantly lower than the prediction of recent models (e.g., Gallino et al.), which succeeded in explaining the metallicity dependence of the abundance ratios of light s-elements (Sr-Zr) to heavy ones (Ba-Dy) found in previously observed s-process-enhanced stars. This suggests that one should either (1) reconsider the underlying assumptions concerning the (13)C-rich s-processing site ((13)C pocket) in the present models or (2) investigate alternative sites of s-process nucleosynthesis in very metal-poor AGB stars.