Insights into Superinfection Immunity Regulation of Xanthomonas axonopodis Filamentous Bacteriophage cf.

Filamentous bacteriophage cf infects Xanthomonas axonopodis pv. citri, a serious plant pathogen which causes citrus canker. To understand the immunity regulation of bacteria infected with bacteriophage cf, we applied DNA shuffling to mutate the cf intergenic region. One of the immunity mutants, cf-m3 (NCBI Taxonomy ID: 3050368) expressed a 106-109 fold greater superinfection ability compared with wild type cf. Nine mutations were identified on the cf-m3 phage, four of which were located within the coding region of an open reading frame (ORF165) for a hypothetical repressor, PT, and five located upstream of the PT coding region. A set of phages with mutations to the predicted PT protein or the upstream coding region were generated. All showed similarly low superinfection efficiency to wild type cf and no superinfection ability on cf lysogens. The results indicate that rather than superinfection inhibition, the PT protein and the un-transcribed cis element function individually as positive regulators of cf superinfection immunity. Greater superinfection ability depends on the simultaneous presence of both elements. This work yields further insight into the possible control of citrus canker disease through phages that overcome host superinfection immunity.

Alcohol Addiction, Gut Microbiota, and Alcoholism Treatment: A Review.

Alcohol addiction is a leading risk factor for personal death and disability. In 2016, alcohol use caused 2.2% of female deaths and 6.8% of male deaths, and disability-adjusted life years (DALYs) were 2.3% in female and 8.9% in male. Individuals with alcohol use disorder are at high risk of anxiety, depression, impaired cognition performance, and illicit drug use and are comorbid with liver disease, such as alcoholic hepatitis and liver cirrhosis, which is a major cause of personal death and disability worldwide. Psychological interventions, such as cognitive behavior therapy and motivational interviewing, as well as medical treatments, such as disulfiram, naltrexone, acamprosate, and nalmefene, are used for the treatment of alcohol addiction in Europe and the United States. However, the effect of current interventions is limited, and the need for additional interventions is substantial. Alcohol use impairs the intestinal barrier and causes changes to the intestinal permeability as well as the gut microbiota composition. Emerging studies have tried to reveal the role of the gut-brain axis among individuals with alcohol use disorder with or without alcohol liver disease. Bacterial products penetrate the impaired intestinal barrier and cause central inflammation; changes to the gut microbiota impair enterohepatic circulation of bile acids; alcohol abuse causes shortage of vital nutrients such as thiamine. Several studies have suggested that probiotics, through either oral administration or fecal microbiota transplantation, increased intestinal levels of potentially beneficial bacteria such as bifidobacteria and lactobacilli, improving the levels of liver-associated enzymes in patients with mild alcoholic hepatitis, and demonstrating beneficial psychotropic effects on anxiety and depression. In addition to medications for alcohol addiction, gene editing therapy such as clustered regularly interspaced short palindromic repeats (CRISPRs) may be another potential research target. Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH), which are associated with ADH and ALDH genes, are major enzymes involved in alcohol metabolism, and gene editing approaches may have the potential to directly modify specific genes to treat alcoholism caused by genetic defects. Further research is needed to study the effect of the combined treatment for alcohol addiction.

Opioid Addiction, Genetic Susceptibility, and Medical Treatments: A Review.

Opioid addiction is a chronic and complex disease characterized by relapse and remission. In the past decade, the opioid epidemic or opioid crisis in the United States has raised public awareness. Methadone, buprenorphine, and naloxone have proven their effectiveness in treating addicted individuals, and each of them has different effects on different opioid receptors. Classic and molecular genetic research has provided valuable information and revealed the possible mechanism of individual differences in vulnerability for opioid addiction. The polygenic risk score based on the results of a genome-wide association study (GWAS) may be a promising tool to evaluate the association between phenotypes and genetic markers across the entire genome. A novel gene editing approach, clustered, regularly-interspaced short palindromic repeats (CRISPR), has been widely used in basic research and potentially applied to human therapeutics such as mental illness; many applications against addiction based on CRISPR are currently under research, and some are successful in animal studies. In this article, we summarized the biological mechanisms of opioid addiction and medical treatments, and we reviewed articles about the genetics of opioid addiction, the promising approach to predict the risk of opioid addiction, and a novel gene editing approach. Further research on medical treatments based on individual vulnerability is needed.

Psychological Distress is Correlated with Erectile Dysfunction Among Patients Receiving Methadone Maintenance in Taiwan.

OBJECTIVE: Although erectile dysfunction (ED) is prevalent in patients receiving long-term methadone maintenance, studies in Chinese culture exploring the relationship between psychological distress and ED are scarce. METHODS: One hundred eighty-seven male patients in methadone maintenance treatment were assessed in this cross-sectional study. Instruments included the Opiate Treatment Index (OTI) to evaluate the health-related consequences of methadone treatment and the Chinese Health Questionnaire-12 (CHQ-12) for the assessment of psychological distress, respectively. ED was defined by the International Index of Erectile Function 15. Quality of life was measured using the European Quality of Life-5 Dimensions. We constructed a multiple linear regression model to examine the associations between the determinants and ED. RESULTS: The CHQ-12 score had a significant relationship with the severity of ED after controlling for all important variables. The social functioning domain of the OTI and methadone dose was also significantly correlated with ED. CONCLUSIONS: The strong relationship between psychological distress and ED emphasized the importance of both diagnosis and management of ED among methadone patients receiving long-term maintenance treatment. The etiological relationship between methadone dose and ED require further investigation.

Psychometric evaluation, using Rasch analysis, of the WHOQOL-BREF in heroin-dependent people undergoing methadone maintenance treatment: further item validation.

BACKGROUND: The brief version of World Health Organization Quality of Life assessment (WHOQOL-BREF), a useful outcome measure for clinical decision making, has been evaluated using classical test theory (CTT) for psychometric properties on heroin-dependent patients. However, CTT has a major disadvantage of invalid summated score, and using Rasch models can overcome the shortcoming. The purpose of this study was using Rasch models to evaluate the psychometric properties of the WHOQOL-BREF for heroin-dependent patients, and the hypothesis was that each WHOQOL-BREF domain is unidimensional. METHODS: Two hundred thirty six participants (24 females, mean [SD] age = 38.07 [7.44] years, first used heroin age = 26.13 [6.32] years), with a diagnosis of opioid dependence, were recruited from a methadone maintenance treatment program. Each participant filled out the WHOQOL-BREF. Parallel analysis (PA) and Rasch rating scale models were used for statistical analyses. RESULTS: Based on the PA analyses, four domains of the WHOQOL-BREF were unidimensional. The Rasch analyses showed three negatively worded items (2 in Physical and 1 in Psychological) reported as misfits that may not contribute to the Physical and Psychological domains; one positively worded item in the Physical domain may be redundant. All values for the separation indices were above 2 except for the person separation index in the Physical domain (1.93). Category functioning and item independency of four WHOQOL-BREF domains were supported by the Rasch analyses, and there were 5 items showing the differential item function (DIF) for positive versus negative HIV (human immunodeficiency virus) infection. CONCLUSIONS: The WHOQOL-BREF is a valid outcome measure for assessing general quality of life for substance abusers in terms of physical, psychological, social, and environmental factors. It can also be used as a treatment outcome measure to evaluate the effect of treatments for substance abusers. However, the three misfit negatively worded items should be used with caution because the substance abuser may not fully understand their meaning. Future research may apply cognitive interviews to determine the cognitive functioning of substance abusers and their interpretation of negatively worded items.

Negative Impacts of Self-Stigma on the Quality of Life of Patients in Methadone Maintenance Treatment: The Mediated Roles of Psychological Distress and Social Functioning.

A sample of heroin users (n = 250) in methadone maintenance treatment (MMT) was used in this cross-sectional study to clarify the mechanisms of the effects of stigma on quality of life (QoL) through psychological distress and social functioning. All the participants had their self-stigma, psychological distress, social functioning, and QoL measured. Psychological distress and social functioning were proposed to be mediators between self-stigma and QoL. Several linear models using structural equation modeling were conducted to examine the mediated effects. The negative effects of self-stigma on QoL were significantly mediated by psychological distress, as self-stigma directly and significantly influenced psychological distress, but not social functioning. This study demonstrated a linear model describing the effects of self-stigma on QoL for opioid-dependent individuals; psychological distress was also an important mediator between self-stigma and their QoL. Clinicians were able to notice the importance of reducing self-stigma for opioid-dependent individuals according to the following results: higher levels of self-stigma were associated with high psychological distress, decreased social functioning, and impaired QoL. Our mediation findings suggest that treating psychological distress is better than treating social functioning if we want to eliminate the effects of self-stigma on QoL for heroin users.

Psychological distress mediated the effects of self-stigma on quality of life in opioid-dependent individuals: A cross-sectional study.

BACKGROUND: Both stigma and psychological distress affect quality of life (QOL). This study is an attempt to determine the effects of these two factors on QOL and to explore possible mediation effects between psychological distress and self-stigma in opioid-dependent individuals. METHODS: This cross-sectional study comprised 268 consecutive, treatment-seeking opioid-dependent individuals who were interviewed using the brief version of the World Health Organization Quality of Life instrument (WHOQOL-BREF), the Self-Stigma Scale-Short (SSS-S), the Chinese Health Questionnaire-12 (CHQ-12), and the Opiate Treatment Index (OTI). A series of regression models were constructed to determine if the SSS-S and CHQ-12 predict the WHOQOL-BREF scores. Moreover, a comparison of the potential mediation effects of psychological distress (as assessed by the CHQ-12) was made between the SSS-S and the WHOQOL-BREF using the Baron and Kenny procedure (including three separate regressions), along with the Sobel test. RESULTS: The CHQ-12 score was predictive of the scores for the four domains and almost all facets of the WHOQOL-BREF except the item, "Dependence on medical aids." Nonetheless, the SSS-S score predicted three of the four facets of the social QOL after adjustment of the CHQ-12 score. Psychological distress completely mediated the relation between self-stigma and the physical, psychological, and environmental domains, and partially mediated the relationship between self-stigma and social QOL (two-tailed Sobel test: p = 0.02 for each domain). CONCLUSIONS: Psychological distress has a significant impact on the QOL of treated opioid users. It appears to be a core element in reducing the negative effects of self-stigma on aspects of QOL.

Opioid users with comorbid hepatitis C spent more time in agonist therapy: A 6-year observational study in Taiwan.

BACKGROUND: Hepatitis C virus (HCV) infection is highly prevalent among opioid agonist therapy (OAT) patients, but little is known about long-term OAT use among this population. METHODS: Subjects diagnosed as opioid dependence were recruited from Mar. 2006 to Jul. 2008 in a psychiatry center in southern Taiwan with the OAT censored in 2012, and their socio-demographics, drug use characteristics, and markers of blood-borne infection were assessed at entry. Correlates with HCV infection and OAT retention were analyzed by multivariate logistic regression. Retention (OAT utilization) was defined as the in-treatment period of OAT during the 6-year observation period. RESULTS: A total of 983 patients (88.3% men) were included. The prevalences of HCV and HIV infection were 91.4% and 17.9%, respectively. The mean duration of OAT during the study period was 2.3±0.8years. Significant correlates with HCV infection were retention of at least three years in OAT (AOR: 4.24, 95%CI: 1.49-12.03), ever sharing injection equipment (AOR: 227.04, 95%CI: 57.22-900.87), not living with family (AOR: 5.54, 95%CI: 1.45-21.16), lower educational attainment (AOR: 2.10, 95%CI: 1.15-3.82) and previous drug offense (AOR: 6.35, 95%CI: 1.69-23.83). Significant correlates with retention were HCV infection (AOR: 2.53, 95%CI: 1.30-4.93) and divorced or separation in marriage (AOR: 0.65, 95%CI: 0.44-0.96). CONCLUSIONS: This six-year observational study revealed a better retention in OAT if opioid-dependent individuals had comorbid hepatitis C. This provided opportunities for OAT patients with HCV infection to obtain medical treatment while staying in an OAT program. Further research could explore the possibility of eradicating comorbid HCV infection among these long-term treatment cases.

Estimation of life expectancy and the expected years of life lost among heroin users in the era of opioid substitution treatment (OST) in Taiwan.

BACKGROUND: Opioid substitution treatment (OST) has been implemented in Taiwan since 2006. We estimated the life expectancy (LE) and expected years of life lost (EYLL) in a cohort of heroin users stratified by OST for comparison. METHODS: A total of 1283 heroin users recruited from 2006 to 2008 were linked to the National Mortality Registry until the end of 2011. Among them, 983 received OST, while 300 did not. Kaplan-Meier estimation for survival was performed, and it was extrapolated to 50 years to obtain the LE using a semi-parametric method. We further estimated the EYLL for both cohorts by subtracting their life expectancies from the age- and sex-matched referents of the general population. Cause-specific standardized mortality ratios (SMRs) were calculated and compared with the national cohort to validate the representativeness of this sample. RESULTS: After extrapolation to 50 years of survival, the estimated average LE and EYLL were 27.4 and 10.6 for OST subjects, respectively, while those of the non-OST were 20.2 and 18.4 years. The all-cause mortality rates (per 1000 person-years) in the observational period for the OST and non-OST group were 15.5 and 23.9, respectively, representing a 7.5- and 10.2-fold SMR compared to the general population, indicating a high representativeness for our sample. But SMR of suicide mortality elevated 16.2 and 3.1 folds in OST and non-OST group, respectively. CONCLUSIONS: OST saves 7.8 EYLL more than non-OST after accounting for lead time bias. Effective suicide prevention programs could enhance its life-saving effect, especially among those co-morbid with depressive disorders.

Development and validation of molecular markers for characterization of Boehmeria nivea var. nivea and Boehmeria nivea var. tenacissima.

BACKGROUND: The root of Boehmeria spp (ramie) is a hepatoprotective Chinese herbal medicine. Medicinal properties vary between Boehmeria nivea var. nivea and Boehmeria nivea var. tenacissima, which are local species found in Taiwan. As commercial preparations may use either species, there is a need for a rapid and simple assay to identify variants for quality control. METHODS: Four methods were developed and tested for their applicability in differentiating the two species. These methods were random amplified polymorphic DNA (RAPD); sequence characterized amplified regions (SCAR); single nucleotide polymorphisms (SNP) and cleaved amplified polymorphic sequences (CAPS). RESULTS: Three RAPD markers were developed that produced unique bands in B. nivea var. tenacissima and B. nivea var. nivea. Based on sequenced RAPD bands, one SCAR marker was developed that produced a single DNA band in B. nivea var. nivea. Two SNP markers differentiated between B. nivea var. nivea and B. nivea var. tenacissima based on single nucleotide substitutions. A pair of CAPS oligonucleotides was developed by amplifying a 0.55-kb DNA fragment that exhibited species-specific digestion patterns with restriction enzymes Alf III and Nde I. Consistent results were obtained with all the four markers on all tested Boehmeria lines. CONCLUSION: The present study demonstrates the use of the RAPD, SCAR, SNP and CAPS markers for rapid identification of two closely related Boehmeria species.

DOMINO1, a member of a small plant-specific gene family, encodes a protein essential for nuclear and nucleolar functions.

Arabidopsis embryos carrying the domino1 mutation grow slowly in comparison with wild type embryos and as a consequence reach only the globular stage at desiccation. The primary defect of the mutation at the cellular level is the large size of the nucleolus that can be observed soon after fertilization in the nuclei of both the embryo and the endosperm. The ultrastructure of mutant nucleoli is drastically different from wild type and points to a fault in ribosome biogenesis. DOMINO1 encodes a protein, which belongs to a plant-specific gene family sharing a common motif of unknown function, present in the tomato DEFECTIVE CHLOROPLASTS AND LEAVES (LeDCL) protein. Using a GFP protein fusion, we show that DOMINO1 is targeted to the nucleus. We propose that inactivation of DOMINO1 has a negative effect on ribosome biogenesis and on the rate of cell division.