Copper Centers in the Cryo-EM Structure of Particulate Methane Monooxygenase Reveal the Catalytic Machinery of Methane Oxidation.

The particulate methane monooxygenase (pMMO) is the first enzyme in the C1 metabolic pathway in methanotrophic bacteria. As this enzyme converts methane into methanol efficiently near room temperature, it has become the paradigm for developing an understanding of this difficult C1 chemistry. pMMO is a membrane-bound protein with three subunits (PmoB, PmoA, and PmoC) and 12-14 coppers distributed among different sites. X-ray crystal structures that have revealed only three mononuclear coppers at three sites have neither disclosed the location of the active site nor the catalytic mechanism of the enzyme. Here we report a cyro-EM structure of holo-pMMO from Methylococcus capsulatus (Bath) at 2.5 Å, and develop quantitative electrostatic-potential profiling to scrutinize the nonprotein densities for signatures of the copper cofactors. Our results confirm a mononuclear CuI at the A site, resolve two CuIs at the B site, and uncover additional CuI clusters at the PmoA/PmoC interface within the membrane (D site) and in the water-exposed C-terminal subdomain of the PmoB (E clusters). These findings complete the minimal set of copper factors required for catalytic turnover of pMMO, offering a glimpse of the catalytic machinery for methane oxidation according to the chemical principles underlying the mechanism proposed earlier.

Differential early predictive factors for upper and lower extremity motor recovery after ischaemic stroke.

BACKGROUND AND PURPOSE: Various clinical and neuroimaging predictive factors have been identified for the recovery of upper extremity (UE) motor function after stroke. However, few studies have addressed factors related to the recovery of lower extremity (LE) motor function after stroke or performed direct comparisons of UE and LE motor recovery in the same set of patients. In this study, predictive factors for UE and LE motor recovery after stroke were investigated using clinical and neuroimaging characteristics. METHODS: Forty-two subacute ischaemic stroke patients underwent structural and functional magnetic resonance imaging data acquisition and cognitive/behavioral assessments using the Fugl-Meyer assessment, the National Institutes of Health Stroke Scale (NIHSS) and the Mini-Mental State Examination (MMSE) 2 weeks after stroke onset. Neuroimaging factors, including corticospinal tract (CST) fractional anisotropy, lesion volume, CST lesion load and interhemispheric homotopic functional connectivity, were extracted. The outcome of motor function was assessed by Fugl-Meyer assessment scores 3 months after onset. RESULTS: Early clinical and neuroimaging factors for predicting motor recovery were noticeably different for UE and LE. UE motor function recovery was related to age, NIHSS, MMSE, CST lesion load, lesion volume, ipsilesional CST integrity and interhemispheric homotopic functional connectivity. In contrast, LE motor recovery was related to ipsilesional and contralesional CST integrity and MMSE. Specifically, LE recovery showed a strong relationship to the preservation of cognitive function compared with motor impairment. CONCLUSIONS: Our results indicate that different mechanisms underlie UE and LE motor recovery after stroke. LE motor recovery seems to be more intensively modulated by cognitive functions than UE.

Utilizing online stochastic optimization on scheduling of intensity-modulate radiotherapy therapy (IMRT).

According to Ministry of Health and Welfare of Taiwan, cancer has been one of the major causes of death in Taiwan since 1982. The Intensive-Modulated Radiation Therapy (IMRT) is one of the most important radiotherapies of cancers, especially for Nasopharyngeal cancers, Digestive system cancers and Cervical cancers. For patients, if they can receive the treatment at the earliest possibility while diagnosed with cancers, their survival rate increases. However, the discussion of effective patient scheduling models of IMRT to reduce patients' waiting time is still limited in literature. This study proposed a mathematical model to improve the efficiency of patient scheduling. The research was composed of two stages. In the first stage, the online stochastic algorithm was proposed to improve the performance of present scheduling system. In the second stage the impact of future treatment to reduce patients' waiting time was considered. A genetic algorithm (GA) was then proposed to solve the online stochastic scheduling problem. This research collected data from a practical medical institute and the proposed model was validated with real data. It contributes to both theory and practice by proposing a practical model to assist the medical institute in implementing patient scheduling in a more efficient manner.

ß-Casomorphin increases fat deposition in broiler chickens by modulating expression of lipid metabolism genes.

ß-Casomorphin is an opioid-like bioactive peptide derived from ß-casein of milk that plays a crucial role in modulating animal's feed intake, growth, nutrient utilization and immunity. However, the effect of ß-casomorphin on lipid metabolism in chickens and its mechanism remain unclear. The aim of this study was to investigate the effects of ß-casomorphin on fat deposition in broiler chickens and explore its mechanism of action. A total of 120 21-day-old Arbor Acres male broilers (747.94±8.85 g) was chosen and randomly divided into four groups with six replicates of five birds per replicate. Three groups of broilers were injected with 0.1, 0.5 or 1.0 mg/kg BW of ß-casomorphin in 1 ml saline for 7 days, whereas the control group received 1 ml saline only. The results showed that subcutaneous administration of ß-casomorphin to broiler chickens increased average daily gain, average daily feed intake and fat deposition, and decreased feed : gain ratio (P<0.05). The activity of malate dehydrogenase in the pectoral muscle, liver and abdominal adipose tissue was also increased along with the concentrations of insulin, very-low-density lipoprotein and triglyceride in the plasma (P<0.05). The activity of hormone-sensitive lipase in the liver and abdominal adipose tissue and the concentration of glucagon in the plasma were decreased by injection with ß-casomorphin (P<0.05). Affymetrix gene chip analysis revealed that administering 1.0 mg/kg BW ß-casomorphin caused differential expression of 168 genes in the liver with a minimum of fourfold difference. Of those, 37 genes are directly involved in lipid metabolism with 18 up-regulated genes such as very low density lipoprotein receptor gene and fatty acid synthase gene, and 19 down-regulated genes such as lipoprotein lipase gene and low density lipoprotein receptor gene. In conclusion, ß-casomorphin increased growth performance and fat deposition of broilers. Regulation of fat deposition by ß-casomorphin appears to take place through changes in hormone secretion and enzyme activities by controlling the gene expression of lipid metabolism and feed intake, increasing fat synthesis and deposition.

[Risk factors related to HIV new infections among men who have sex with men in a cohort study].

Objectives: To analyze and understand the risk factors related to HIV new infections among men who have sex with men (MSM). Methods: A longitudinal observational study among MSM was conducted to collect information on HIV related behaviors and sero-conversion. Univariate and multivariate generalized estimating equations (GEE) were used to discuss the risk factors for HIV new infection. Results: A total number of 4 305 MSM were followed during 2013-2015. Among those self-reported MSM who are seeking partners on the Interner tended to have higher proportion on receptive anal intercourse and consistent condom use during anal intercourse than the subgroups seeking their partners in gay bars or bathrooms. HIV incidence among followed MSM during the study period appeared as 4.3/100 person years, with adjusted RR (aRR) of HIV infection for receptive anal intercourse as group 2.20 (95% CI: 1.49-3.24) times than that of insertion anal intercourse group. Those who used rush-poppers (aRR=1.55, 95% CI: 1.10-2.17), unprotected anal intercourse (aRR=2.24, 95%CI: 1.62-3.08), and those with syphilis infection (aRR=2.95, 95%CI: 2.00-4.35) were also risk factors for HIV new infections. After controlling other factors, the relationship between the ways of seeking partners and HIV new infection was not statistical significant. Conclusion: Risk factors for HIV new infection among MSM appeared complex and interactive, suggesting that further studies are needed to generate tailored strategies for the prevention of HIV epidemic among MSM population.

Effect of gut stress induced by oxidized wheat gluten on the growth performance, gut morphology and oxidative states of broilers.

This study was to investigate the effect of oxidized wheat gluten (OG) on growth performance, gut morphology and its oxidative states of broilers. One hundred and eighty-day-old male broilers (10 chicks/pen) were randomly allocated into three dietary treatments: control diet (CON), diet with 8% wheat gluten (WG) and diet with 8% OG with six pens/treatment. Body weight (BW) (21 and 35 days) and average daily gain (ADG) (1-21 days and 22-35 days) decreased (p < .05) and feed conversion ratio (FCR) (1-21 days and 22-35 days) increased (p < .05) in OG treatment. Feed intake (FI) decreased (p < .05) in WG and OG treatments during 22-35 days. However, FI was not influenced by dietary treatments during 1-21 days (p > .05). The OG-fed broilers had a lower faecal pH value (p < .05) and higher faecal moisture content (p < 05) at 14, 21, 28 and 35 days. Villus height, crypt depth and V/C value were not different (p > .05) among treatments at 21 and 35 days. Lipid peroxidation (LPO) (21 and 35 days) and malondialdehyde (MDA) (35 days) content in crop of OG treatment increased (p < .05). Oxidized glutathione (GSSG) (21 days), LPO (21 and 35 days) and MDA (21 and 35 days) content in ileum of OG treatment increased (p < .05). The reduced glutathione/oxidized glutathione (GSH/GSSG) (21 days) and (GSH) (35 days) in ileum of OG treatment decreased (p < .05). The present findings indicate that OG might be a stressor for broiler gut, which could induce oxidative stress both in crop and in ileum, and the diarrhoea as well. The growth performance of broiler was consequently depressed.

Co-aggregation of major psychiatric disorders in individuals with first-degree relatives with schizophrenia: a nationwide population-based study.

A previous genetic study has suggested that schizophrenia, bipolar disorder, major depressive disorder, autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD) share common disease-associated genes. However, whether individuals with first-degree relatives (FDRs) with schizophrenia have a higher risk of these major psychiatric disorders requires further investigation. This study used Taiwan's National Health Insurance Research Database and identified 151 650 patients with schizophrenia and 227 967 individuals with FDRs with schizophrenia. The relative risks (RRs) of schizophrenia and other major psychiatric disorders were assessed in individuals with FDRs with schizophrenia. The individuals with FDRs with schizophrenia exhibited higher RRs (95% confidence interval) of major psychiatric disorders, namely schizophrenia (4.76, 4.65-4.88), bipolar disorder (3.23, 3.12-3.35), major depressive disorder (2.05, 2.00-2.10), ASD (2.55, 2.35-2.77) and ADHD (1.31, 1.25-1.37) than were found in the total population. Several sensitivity analyses were conducted to confirm these results. A dose-dependent relationship was observed between the risks of major psychiatric disorders and the numbers of FDRs with schizophrenia. The increased risks of major psychiatric disorders were consistent in different family relationships, namely among parents, offspring, siblings and twins. Our study supports the familial dose-dependent co-aggregation of schizophrenia, bipolar disorder, major depressive disorder, ASD and ADHD, and our results may prompt governmental public health departments and psychiatrists to focus on the mental health of individuals with FDRs with schizophrenia.

Recovery-related indicators of motor network plasticity according to impairment severity after stroke.

BACKGROUND AND PURPOSE: Brain connectivity analysis has been widely used to investigate brain plasticity and recovery-related indicators of patients with stroke. However, results remain controversial because of interindividual variability of initial impairment and subsequent recovery of function. In this study, we aimed to investigate the differences in network plasticity and motor recovery-related indicators according to initial severity. METHODS: We divided participants (16 males and 14 females, aged 54.2 ± 12.0 years) into groups of different severity by Fugl-Mayer Assessment score, i.e. moderate (50-84), severe (20-49) and extremely severe (<20) impairment groups. Longitudinal resting-state functional magnetic resonance imaging data were acquired at 2 weeks and 3 months after onset. The differences in network plasticity and recovery-related indicators between groups were investigated using network distance and graph measurements. RESULTS: As the level of impairment increased, the network balance was more disrupted. Network balance, interhemispheric connectivity and network efficiency were recovered at 3 months only in the moderate impairment group. However, this was not the case in the extremely severe impairment group. A single connection strength between the ipsilesional primary motor cortex and ventral premotor cortex was implicated in the recovery of motor function for the extremely severe impairment group. The connections of the ipsilesional primary motor cortex-ventral premotor cortex were positively associated with motor recovery as the patients were more severely impaired. CONCLUSIONS: Differences in plasticity and recovery-related indicators of motor networks were noted according to impairment severity. Our results may suggest meaningful implications for recovery prediction and treatment strategies in future stroke research.

[HIV infection and associated factors in HIV-antibody positive clients of female sex workers recently reported in Shaanxi province].

Objective: To investigate the current status of HIV infection and the related factors in HIV antibody positive clients of female sex workers (FSWs) recently reported in Shaanxi province. Methods: The HIV/AIDS cases newly diagnosed in males living in Shaanxi from January 1th of 2013 to June 30th of 2014 were selected and those infected through " commercial heterosexual behavior" were identified. The information about their demographic characteristics, previous unprotected heterosexual sex and the sample sources were collected, and serum or plasma samples were collected from them and tested with BED-CEIA. The proportion of recent HIV infections and associated factors were investigated. Results: The proportion of recent HIV infection and HIV-antibody detection rate in 212 HIV antibody positive male clients of FSWs were 25.5% and 6.6% respectively. The cases who had the educational level of junior middle school or high middle school were wore likely to have long term HIV infections than those with lower educational level (aOR=0.28, 95% CI: 0.08-0.93). Compared with patients identified by hospitals or sexually transmitted diseases clinics, recent HIV infections were more likely to be found through preoperative test or blood transfusion test (aOR=3.14, 95% CI: 1.06-9.30) and blood donation test (aOR=4.19, 95% CI:1.01-17.42). Compared with the cases who had commercial sex only in Xi' an or other province or both in Xi' an and other province, the cases who had commercial sex in other cities in Shaanxi were more likely to be infected recently (aOR=0.19, 95%CI: 0.07-0.57). Compared with the cases had temporary heterosexual sex partner, those who had no temporary sex partners were more likely to be infected recently (aOR=9.03, 95% CI: 3.00-27.18) (P<0.05). Conclusions: The proportion of recent HIV infections among HIV antibody positive clients of FSWs was high and the HIV-antibody detection rate among them was low. The educational level, sample source, geographic area and temporary heterosexual partner were related factors for recent HIV infection. The HIV infection in the clients of FSWs, especially those with lower educational level, was serious in Shaanxi. It is necessary to strengthen behavior intervention and improve HIV defection according to the characteristics of this population.

[HIV/STD prevalence and related behaviors among male STD clinic attendees in Xi'an and Xianyang cities, Shaanxi province].

Objective: To compare the prevalence of HIV/STD and related health care seeking behaviors among male STD clinic attendees between Xi'an and Xianyang cities. Methods: During June and July 2016, 206 male STD clinic attendees were studied in Xi'an city, with another 221 male STD clinic attendees in Xianyang city. Cross-sectional questionnaire survey was used to collect attendees'behavioral information. Blood samples were collected via HIV/HCV/Syphilis testing. Results: The prevalence rate of HIV infection was 2.4% (5/206) in Xi'an and 0.9% (2/221) in Xianyang, with no statistical significant difference between the two cities. The prevalence rate of syphilis was 4.9% (10/206) in Xi'an, which was significantly lower than 13.6% (30/221) in Xianyang. The proportion of respondents, diagnosed with other sexually transmitted diseases, in Xi'an was higher than that of Xianyang. The proportions of commercial heterosexual sex and sex with temporary sexual partners in the past 3 months were 18.0% (37/206) and 15.5% (32/206) in Xi'an, lower than 46.6% (103/221) and 15.8% (35/221) in Xianyang (χ(2)=39.70, Р<0.01; χ(2)=0.01, P=0.93) . The proportions of condom use with commercial sex workers or temporary sexual partners in the past 3 months among Xi'an were 37.8% (14/37) and 6.3% (2/32) , lower than 93.1% (95/102) and 57.1% (20/35) in Xianyang (χ(2)=49.06, Р<0.01; χ(2)=19.63, Р<0.01) . Conclusion: Differences were noticed between Xi'an and Xianyang city in terms of STD and HIV prevalences, behaviors related to commercial sex and use of condoms among the male STD clinic attendees that calling for targeted actions in control of high risk behavlors in both HIV/AIDS and STDs transmission.