Modulation of DNA repair capacity and mRNA expression levels of XRCC1, hOGG1 and XPC genes in styrene-exposed workers

Decreased levels of single-strand breaks in DNA (SSBs), reflecting DNA damage, have previously been observed with increased styrene exposure in contrast to a dose-dependent increase in the base-excision repair capacity. To clarify further the above aspects, we have investigated the associations between SSBs, micronuclei, DNA repair capacity and mRNA expression in XRCC1, hOGG1 and XPC genes on 71 styrene-exposed and 51 control individuals. Styrene concentrations at workplace and in blood characterized occupational exposure. The workers were divided into low (below 50 mg/m³) and high (above 50 mg/m³) styrene exposure groups. DNA damage and DNA repair capacity were analyzed in peripheral blood lymphocytes by Comet assay. The mRNA expression levels were determined by qPCR. A significant negative correlation was observed between SSBs and styrene concentration at workplace (R = − 0.38, p = 0.001); SSBs were also significantly higher in men (p = 0.001). The capacity to repair irradiation-induced DNA damage was the highest in the low exposure group (1.34 ± 1.00 SSB/10⁹ Da), followed by high exposure group (0.72 ± 0.81 SSB/10⁹ Da) and controls (0.65 ± 0.82 SSB/10⁹ Da). The mRNA expression levels of XRCC1, hOGG1 and XPC negatively correlated with styrene concentrations in blood and at workplace (p < 0.001) and positively with SSBs (p < 0.001). Micronuclei were not affected by styrene exposure, but were higher in older persons and in women (p < 0.001). In this study, we did not confirm previous findings on an increased DNA repair response to styrene-induced genotoxicity. However, negative correlations of SSBs and mRNA expression levels of XRCC1, hOGG1 and XPC with styrene exposure warrant further highly-targeted study.     

Assessment of nicotine dependence among adolescent and young adult smokers: A comparison of measures

Introduction

Tobacco use often starts in adolescence, yet assessment of dependence among adolescent smokers remains a challenge, particularly given the potential discord between self-reports of smoking behavior and actual use. We could find no prior study, among adolescents, that directly compares the association between objective biomarkers of tobacco exposure (e.g., cotinine) and multiple measures of dependence. This study examined the concurrent validity of two common dependence measures: the Fagerström Test for Nicotine Dependence (FTND) and the Hooked on Nicotine Checklist (HONC). We further examined the FTND by removing the one item on cigarettes smoked per day.

Methods

Based within a parent clinical trial for adolescent smoking cessation, eligible participants were 12–21 years old, smoking ≥ 5 cigarettes per day on average, and with urine cotinine > 100 ng/ml at baseline. Results are based on participants who completed each measure and who provided a urine cotinine sample at baseline (N = 73).

Results

Results showed that the FTND was associated with cotinine (p < 0.001; R² = 0.25), and that this relationship held true for the revised FTND as well (p < 0.001; R² = 0.18). However, the HONC was only marginally associated with cotinine (p = 0.06; R² = 0.09).

Discussion

Our results suggest that the FTND may be better associated with actual smoking behavior in adolescents as compared to the HONC. Pending replication, our data provide caution with regard to assessment of nicotine dependence at least among established adolescent smokers who have more entrenched smoking behavior.     

Radiopharmaceutical chemistry for positron emission tomography

Molecular imaging is an emerging technology that allows the visualization of interactions between molecular probes and biological targets. Molecules that either direct or are subject to homeostatic controls in biological systems could be labeled with the appropriate radioisotopes for the quantitative measurement of selected molecular interactions during normal tissue homeostasis and again after perturbations of the normal state. In particular, positron emission tomography (PET) offers picomolar sensitivity and is a fully translational technique that requires specific probes radiolabeled with a usually short-lived positron-emitting radionuclide. PET has provided the capability of measuring biological processes at the molecular and metabolic levels in vivo by the detection of the gamma rays formed as a result of the annihilation of the positrons emitted. Despite the great wealth of information that such probes can provide, the potential of PET strongly depends on the availability of suitable PET radiotracers. However, the development of new imaging probes for PET is far from trivial and radiochemistry is a major limiting factor for the field of PET. In this review, we provided an overview of the most common chemical approaches for the synthesis of PET-labeled molecules and highlighted the most recent developments and trends. The discussed PET radionuclides include ¹¹C (t_1/2 = 20.4 min), ¹³N (t_1/2 = 9.9 min), ¹⁵O (t_1/2 = 2 min), ⁶⁸Ga (t_1/2 = 68 min), ¹⁸F (t_1/2 = 109.8 min), ⁶⁴Cu (t_1/2 = 12.7 h), and ¹²⁴I (t_1/2 = 4.12 d).     

Cognitive impairments in poly-drug ketamine users

Rationale

Cognitive impairment has been found to be reversible in people with substance abuse, particularly those using ketamine. Ketamine users are often poly-substance users. This study compared the cognitive functions of current and former ketamine users who were also abusing other psychoactive substances with those of non-users of illicit drugs as controls.

Methods

One hundred ketamine poly-drug users and 100 controls were recruited. Drug users were divided into current (n = 32) and ex-users (n = 64) according to the duration of abstinence from ketamine (> 30 days). The Beck Depression Inventory (BDI), the Hospital Anxiety Depression Scale (HADSA) and the Severity of Dependence Scale (SDS) were used to evaluate depression and anxiety symptoms and the severity of drug use, respectively. The cognitive test battery comprised verbal memory (Wechsler Memory Scale III: Logic Memory and Word List), visual memory (Rey–Osterrieth Complex Figure, ROCF), executive function (Stroop, Wisconsin Card Sorting Test, and Modified Verbal Fluency Test), working memory (Digit Span Backward), and general intelligence (Information, Arithmetic and Digit-Symbol Coding) tests.

Results

Current users had higher BDI and HADSA scores than ex-users (p < 0.001 for BDI and p = 0.022 for HADSA) and controls (p < 0.001 for BDI and p = 0.002 for HADSA). Ex-users had higher BDI (p = 0.006) but equal HADSA scores (p = 1.000) compared to controls. Both current and ex-users had lower scores on Logical Memory delayed recall (p = 0.038 for current users and p = 0.032 for ex-users) and ROCF delayed recall (p = 0.033 for current users and p = 0.014 for ex-users) than controls. Current users also performed worse on ROCF recognition than controls (p = 0.002). No difference was found between the cognitive functions of current and ex-users.

Conclusions

Ketamine poly-drug users displayed predominantly verbal and visual memory impairments, which persisted in ex-users. The interactive effect of ketamine and poly-drug use on memory needs further investigation.     

Abnormalities in the tricarboxylic acid (TCA) cycle in the brains of schizophrenia patients

Images of brain metabolism and measurements of activities of components of the electron transport chain support earlier studies that suggest that brain glucose oxidation is inherently abnormal in a significant proportion of persons with schizophrenia. Therefore, we measured the activities of enzymes of the tricarboxylic (TCA) cycle in dorsolateral-prefrontal-cortex from schizophrenia patients (N = 13) and non-psychiatric disease controls (N = 13): the pyruvate dehydrogenase complex (PDHC), citrate synthase (CS), aconitase, isocitrate dehydrogenase (ICDH), the alpha-ketoglutarate dehydrogenase complex (KGDHC), succinate thiokinase (STH), succinate dehydrogenase (SDH), fumarase and malate dehydrogenase (MDH). Activities of aconitase (18.4%, p < 0.05), KGDHC (26%) and STH (28.2%, p < 0.05), enzymes in the first half of the TCA cycle, were lower, but SDH (18.3%, p < 0.05) and MDH (34%, p < 0.005), enzymes in the second half, were higher than controls. PDHC, CS, ICDH and fumarase activities were unchanged. There were no significant correlations between enzymes of TCA cycle and cognitive function, age or choline acetyl transferase activity, except for aconitase activity which decreased slightly with age (r = 0.55, p = 003). The increased activities of dehydrogenases in the second half of the TCA cycle may reflect a compensatory response to reduced activities of enzymes in the first half. Such alterations in the components of TCA cycle are adequate to alter the rate of brain metabolism. These results are consistent with the imaging studies of hypometabolism in schizophrenia. They suggest that deficiencies in mitochondrial enzymes can be associated with mental disease that takes the form of schizophrenia.     

Gender differences in abusers of amphetamine-type stimulants and ketamine in southwestern China

The objective of this study was to investigate abuse conditions of new-type drugs for users who are seeking treatment, gender differences, and differences between the amphetamine-type stimulants (ATS) users and mixed amphetamine-type stimulants and ketamine (ATS + K) poly-drug users. A retrospective analysis was conducted of patients with a final diagnosis of the substance use disorder according to the Diagnoses and Statistical Manual of Mental Disorders Fourth Edition (DSM-IV) who underwent treatment for exposure to new-type drugs at the mental health center of the West China Hospital from March 2009 to May 2011. A questionnaire was used to collect information about socio-demographics, drug abuse conditions and psychiatric co-morbidities. Male subjects were older (p = 0.026), had low level education (p = 0.003), were less previously married (p < 0.001), were more likely to be employed and to hold higher status jobs (p = 0.007); 77.1% of subjects had a psychotic disorder, 28.0% of subjects had a mood disorder, 39.7% had an anxiety disorder, and 45.0% had a cognitive impairment disorder. More men used methamphetamine MA (p < 0.001), tobacco (p = 0.014) and more than one drug substance (p = 0.004) compared to women; women were more vulnerable to mood disorders (p = 0.034) than men. For the males, the ATS + K patients were more likely to use 3, 4-methylenedioxymethamphetamine MDMA (p < 0.001) and develop more psychotic disorders (p = 0.04) than the ATS patients; for females, the ATS + K patients were more likely to use MDMA (p = 0.002), alcohol (p = 0.014) and develop more cognitive impairment disorder (p = 0.034). The present study found that the new-type drug patients have a high degree of psychiatric morbidities; more men were using MA, tobacco and multi-substance and more women patients experience mood disorder in the gender differences. For the males, the ATS + K patients were more likely to use MDMA (3, 4-methylenedioxymethamphetamine) and develop more psychotic disorders than the ATS patients; for females, the ATS + K patients were more likely to use MDMA, alcohol and develop more cognitive impairment disorder. These results suggested that the psychiatrists should focus on the mood disorder among females, psychotic disorders among males who abuse ATS and ketamine, and cognitive impairment disorder for the females who abuse ATS and ketamine.     

Anterior Cingulate Glutamate Levels Related to Clinical Status Following Treatment in First-Episode Schizophrenia

Many patients with schizophrenia show a limited symptomatic response to treatment with dopaminergic antipsychotics. This may reflect the additional involvement of non-dopaminergic neurochemical dysfunction in the pathophysiology of the disorder. We tested the hypothesis that brain glutamate levels would differ between patients with first-episode psychosis who were symptomatic compared with those with minimal symptoms following antipsychotic treatment. Proton magnetic resonance spectroscopy (1H-MRS) spectra were acquired at 3 Tesla in the anterior cingulate cortex and left thalamus in 15 patients with first-episode psychosis in symptomatic remission, and 17 patients with first-episode psychosis who were still symptomatic following at least one course of antipsychotic treatment. Metabolite levels were estimated in ratio to creatine (Cr) using LCModel. Levels of glutamate/Cr in the anterior cingulate cortex were significantly higher in patients who were still symptomatic than in those in remission (T(30)=3.02; P=0.005). Across the entire sample, higher levels of glutamate/Cr in the anterior cingulate cortex were associated with a greater severity of negative symptoms (r=0.42; P=0.017) and a lower level of global functioning (r=−0.47; P=0.007). These findings suggest that clinical status following antipsychotic treatment in schizophrenia is linked to glutamate dysfunction. Treatment with compounds acting on the glutamatergic system might therefore be beneficial in patients who respond poorly to dopaminergic antipsychotics.     

Predictors of antipsychotic-induced weight gain in first-episode psychosis: conclusions from a randomized, double-blind, controlled prospective study of olanzapine, risperidone, and haloperidol

BACKGROUND: Antipsychotic-induced weight gain is one of the most distressing adverse effects being observed in recent times. Most studies have been limited by several confounders. AIM: To evaluate the predictors of antipsychotic-induced weight gain in drug-naive patients with first-episode psychosis treated with olanzapine, risperidone, or haloperidol and compare them with a healthy matched control group. METHODS: Newly diagnosed patients with first-episode schizophrenia treated with antipsychotic medication-olanzapine, risperidone, or haloperidol-and matched healthy controls were followed for 6 weeks. Body mass index (BMI), waist circumference, and weight changes and proportions of subjects with more than 7% weight gain were calculated. The predictors of weight gain were explored. RESULTS: Ninety-nine patients with first-episode schizophrenia and 51 healthy controls were examined. Waist circumference (r = -0.25; P < 0.01) and weight (r = -0.24; P < 0.01) at baseline in addition to the disease process (P < 0.001) as well as antipsychotic use (P < 0.001) were associated with greater increases in weight and BMI. Olanzapine (77%) had greater clinically significant weight gain as compared with risperidone (63%) and haloperidol (22%). Lower BMI at baseline and a diagnosis of undifferentiated schizophrenia were associated with antipsychotic-induced weight gain. CONCLUSIONS: The results confirm clinically significant and substantial weight gain induced by antipsychotic treatment in drug-naive patients with first-episode schizophrenia and identify several risk factors for weight gain such as lower BMI scores, use of olanzapine, and a diagnosis of undifferentiated schizophrenia.     

The impact of pregaming on subsequent blood alcohol concentrations: An event-level analysis

Pregaming has been highlighted as an especially deleterious college drinking ritual. The present study assessed (a) event-level associations between pregaming and biologic samples of blood alcohol concentration (BrAC) and (b) the impact of one's alcohol-related behaviors (measured by AUDIT-C scores) on the likelihood that respondents would report pregaming prior to a night out drinking. The sample included adult (n = 1029; collegiate and non-college-affiliated) bar patrons in a southeastern college community. Multiple and linear regressions were conducted to determine the association between pregaming and BrAC levels, and pregaming and the presence of an alcohol use disorder, respectively. After controlling for the influence of time of data collection, gender, age, college student status, and ethnicity, the linear regression model explained 15.5% (R² = .155) of the variance in BrAC levels (F (10, 915) = 16.838, p < 0.001), of which 10.8% was accounted for by self-reported pregaming alone. Furthermore, pregamers exhibited significantly higher BrACs compared to non-pregamers (β = .332, p < .001). Logistic regression analyses indicated that AUDIT-C scores were the only significant predictor of pregaming status (OR = 1.305, Wald = 64.843), such that respondents with higher AUDIT-C scores (B = 0.266) were more likely to pregame. This event-level study highlights the practice of pregaming as an insidious behavior associated with enhanced levels of drinking behavior and overall intoxication.     

Individualized smoking cessation treatment in an outpatient setting: Predictors of outcome in a sample with psychiatric and addictions co-morbidity

Objective

Patients with psychiatric disorders have higher rates of smoking and greater difficulty quitting smoking. However, few studies have compared patients with schizophrenia or schizoaffective disorders to patients with other psychiatric diagnoses without psychosis, addressing ability to quit and differences in treatment characteristics.

Method

A retrospective chart review was conducted on a sample of 165 cigarette smokers admitted to an outpatient smoking cessation clinic located in a large inner-city psychiatric hospital. Patients with schizophrenia and schizoaffective disorder (n = 55) were matched for age and sex at a ratio of 1:2 with a comparison group without psychosis (n = 110) from the same clinic. Primary outcomes of interest were quit status (7-day point prevalence) and significant reduction in cigarettes per day (≥ 50% but not quit) at final treatment session.

Results

There were no significant differences between groups for end-of-treatment quit rate or significant reduction (≥ 50%) in cigarettes per day. Patients with schizophrenia made significantly more visits to the clinic and were in treatment for a longer period of time. A greater number of individual treatment sessions and being male were the most significant predictors of cessation.

Conclusion

Patients with schizophrenia were as likely to quit smoking as a comparison group of patients with a high rate of other psychiatric comorbidities without psychosis. Findings suggest treatment success in this population requires an extended number of clinic visits, group therapy, and possibly higher doses of nicotine replacement.     

Factors associated with weight changes in successful quitters participating in a smoking cessation program

Objective

To identify possible predictors of post-cessation weight gain in smoking abstainers.

Patients and methods

A sample of 607 successful abstainers seen at the Centre for Tobacco-Dependent in Prague, Czech Republic, between 2005 and 2010, was included in this analysis. This sample was followed up for 1 year and included 47.9% women (N = 291) with the mean age of 48 years (18–85).

Findings

Post-cessation weight gain occurred in 88.6% of the 607 abstainers. The mean weight gain after one year post-quit was 5.1 kg (95% confidence interval 4.7–5.5 kg). Baseline characteristics associated with increased weight gain included a higher baseline smoking rate (p < 0.001), more severe cigarette dependence (p = 0.003), less physical activity (p = 0.008), and a report of increased appetite on the baseline assessment of withdrawal symptoms (p < 0.001).

Conclusions

Smokers who are more dependent and have minimal physical activity are at increased risk for post-cessation weight gain. For these smokers, incorporating interventions targeting the weight issue into tobacco dependence treatment is recommended. Further research should be done to identify reasons for this important quitting complication.     

Effects of adult-onset choline deprivation on the activities of acetylcholinesterase, (Na,K)- and Mg-ATPase in crucial rat brain regions

Choline (Ch) plays an important role in brain neurotransmission, while Ch-deprivation (CD) has been linked to various pathophysiological states. Prolonged ingestion of Ch-deficient diet (CDD) is known to produce CD causing a reduction of rat brain acetylcholine (ACh) levels, as well as memory and growth disorders. The aim of this study was to investigate the effect of a 2-month adult-onset CD on the activities of acetylcholinesterase (AChE), (Na⁺,K⁺)- and Mg²⁺-ATPase in crucial brain regions of male rats. Adult rats were divided into two groups (control and CD). The CD group was fed with CDD for 2-months. At the end of the second month, rats were sacrificed by decapitation and the brain regions were rapidly removed. Enzyme activities were measured spectrophotometrically in the homogenated frontal cortex, hippocampus, hypothalamus, cerebellum, and pons. In CD rats, AChE activity was found statistically significantly increased in the hippocampus and the cerebellum (+28%, P < 0.001 and +46%, P < 0.001, respectively, as compared to control), while it was found unaltered in the other three regions (frontal cortex, hypothalamus and pons). (Na⁺,K⁺)-ATPase activity was found increased by CD in the frontal cortex (+30%, P < 0.001), decreased in both hippocampus and hypothalamus (−68%, P < 0.001 and −51%, P < 0.001, respectively), and unaltered in both cerebellum and pons. No statistically significant changes were observed in the activities of Mg²⁺-ATPase in the frontal cortex and the hypothalamus, while statistically significant increases were recorded in the hippocampus (+21%, P < 0.01), the cerebellum (+85%, P < 0.001) and the pons (+19%, P < 0.05), as compared to control levels. Our data suggest that adult-onset CD can have significant effects on the examined brain parameters in the examined crucial brain regions, as well as that CD is a metabolic disorder towards which different and brain region specific neurophysiological responses seem to occur. Following a 2-month adult-onset CD, the activity of AChE was found to be increased in the hippocampus and the cerebellum and unaltered in the other three regions (frontal cortex, hypothalamus and pons), while Na⁺,K⁺-ATPase activity was found to be increased in the frontal cortex, decreased in both hippocampus and hypothalamus, and unaltered in both cerebellum and pons. Moreover, Mg²⁺-ATPase activity was found to be unaltered in the frontal cortex and the hypothalamus, and increased in the hippocampus, the cerebellum and the pons. The observed differentially affected activities of AChE, (Na⁺,K⁺)-ATPase and Mg²⁺-ATPase (induced by CD) could result in modulations of cholinergic neurotransmission, neural excitability, metabolic energy production, Mg²⁺ homeostasis and protein synthesis (that might have a variety of neurophysiological consequences depending on the brain region in which they seem to occur).     

Identification of functional bradykinin B(2) receptors endogenously expressed in HEK293 cells

The human embryonic kidney (HEK) 293 cell line is widely used in cell biology research. Although HEK293 cells have been meticulously studied, our knowledge about endogenous G protein-coupled receptors (GPCR) in these cells is incomplete. While studying the effects of bradykinin (BK), a potent growth factor for renal cells, we unexpectedly discovered that BK activates extracellular signal-regulated protein kinase 1 and 2 (ERK) in HEK293 cells. Thus, we hypothesized that HEK293 cells possess endogenous BK receptors. RT-PCR demonstrated the presence of mRNAs for BK B₁ and BK B₂ receptors in HEK293 cells. Western blotting with BK B₁ and BK B₂ receptor antibodies confirmed this result at the protein level. To establish that BK receptors are functional, we employed fluorescent measurements of intracellular Ca²⁺, measured changes in extracellular acidification rate (ECAR) as a reflection of the Na⁺/H⁺ exchange (NHE) with a Cytosensor™ microphysiometer, and assessed ERK activation by Western blotting with a phospho-specific ERK antibody. Exposure of HEK293 cells to BK produced a concentration-dependent rise in intracellular Ca²⁺ (EC₅₀ = 36.5 ± 8.0 × 10⁻⁹ M), a rapid increase in tyrosine phosphorylation of ERK (EC₅₀ = 9.8 ± 0.4 × 10⁻⁹ M), and elevation in ECAR by ∼20%. All of these signals were blocked by HOE-140 (B₂ receptor antagonist) but not by des-Arg¹⁰-HOE-140 (B₁ receptor antagonist). We conclude that HEK293 cells express endogenous functional BK B₂ receptors, which couple to the mobilization of intracellular Ca²⁺, increases in ECAR and increases in ERK phosphorylation.     

The lipid lowering drug lovastatin protects against doxorubicin-induced hepatotoxicity

Ambient particulate matter (PM) can increase the incidence of arrhythmia. However, the arrhythmogenic mechanism of PM is poorly understood. This study investigated the arrhythmogenic mechanism of PM. In Sprague-Dawley rats, QT interval was increased from 115.0 ± 14.0 to 142.1 ± 18.4 ms (p = 0.02) after endotracheal exposure of DEP (200 μg/ml for 30 min, n = 5). Ventricular premature contractions were more frequently observed after DEP exposure (100%) than baseline (20%, p = 0.04). These effects were prevented by pretreatment of N-acetylcysteine (NAC, 5 mmol/L, n = 3). In 12 Langendorff-perfused rat hearts, DEP infusion of 12.5 μg/ml for 20 min prolonged action potential duration (APD) at only left ventricular base increasing apicobasal repolarization gradients. Spontaneous early afterdepolarization (EAD) and ventricular tachycardia (VT) were observed in 8 (67%) and 6 (50%) hearts, respectively, versus no spontaneous triggered activity or VT in any hearts before DEP infusion. DEP-induced APD prolongation, EAD and VT were successfully prevented with NAC (5 mmol/L, n = 5), nifedipine (10 μmol/L, n = 5), and active Ca^2 +/calmodulin-dependent protein kinase II (CaMKII) blockade, KN 93 (1 μmol/L, n = 5), but not by thapsigargin (200 nmol/L) plus ryanodine (10 μmol/L, n = 5) and inactive CaMKII blockade, KN 92 (1 μmol/L, n = 5). In neonatal rat cardiomyocytes, DEP provoked ROS generation in dose dependant manner. DEP (12.5 μg/ml) induced apoptosis, and this effect was prevented by NAC and KN 93. Thus, this study shows that in vivo and vitro exposure of PM induced APD prolongation, EAD and ventricular arrhythmia. These effects might be caused by oxidative stress and CaMKII activation.     

Carbon monoxide feedback in a motivational decision support system for nicotine dependence among smokers with severe mental illnesses

Health concerns are common reasons for wanting to quit smoking among smokers with mental illnesses. Motivational interventions have used feedback from a carbon monoxide monitor to increase awareness of health concerns, but this device is not commonly available. Whether brief motivational interventions can be effective without this feedback is unknown. Using a randomized controlled trial, this study tested the effect of carbon monoxide feedback within a brief, multi-component, computerized motivational intervention among 124 smokers with schizophrenia or mood disorders. The main outcome was initiating cessation treatment over two months. Although participants in the carbon monoxide group increased their knowledge about the carbon monoxide, (χ² = 6.97, df = 1, p = .008), the main and secondary outcomes did not differ significantly between groups. Overall, 32% of participants initiated treatment. This study suggests that a computerized motivational decision support system can lead users to initiate cessation treatment, and that carbon monoxide feedback is not a necessary component.     

Interaction of sanguinarine and its dihydroderivative with the Na/K-ATPase. Complex view on the old problem

The effects of sanguinarine (SG) and its metabolite dihydrosanguinarine (DHSG) on Na⁺/K⁺-ATPase were investigated using fluorescence spectroscopy. The results showed that the enzyme in E1 conformation can bind both charged and neutral (pseudobase) forms of SG with a K_D = 7.2 ± 2.0 μM or 11.7 ± 0.9 μM, while the enzyme in E2 conformation binds only the charged form of SG with a K_D = 4.7 ± 1.1 μM. Fluorescence quenching experiments suggest that the binding site in E1 conformation is located on the surface of the enzyme for both forms but the binding site in E2 conformation is protected from the solvent. We found no evidence for interaction of Na⁺/K⁺-ATPase and DHSG. This implies that any in vivo effect of SG attributable to inhibition of Na⁺/K⁺-ATPase can be considered only prior to SG → DHSG transformation in the gastro-intestinal tract and/or blood. Hence, Na⁺/K⁺-ATPase inhibition will be effective in SG topical application but its duration will be very limited in SG oral or parenteral administration.     

Caregiver and self-report of mental health symptoms in 9-year old children with prenatal cocaine exposure

Objective

To assess the effect of prenatal cocaine exposure on mental health symptoms in 9-year old children controlling for potential confounders.

Methods

332 children (170 prenatally cocaine-exposed (PCE), 162 non cocaine-exposed (NCE) were assessed using self (Dominic Interactive; DI) and caregiver report (Child Behavior Checklist; CBCL).

Results

Higher levels of PCE were associated with caregiver report of clinically elevated aggressive and delinquent behavior. With each increased unit of PCE, children were 1.3 times more likely to be rated as aggressive (OR = 1.30, 95% CI: 1.02-1.67, p < 0.04). For each increased unit of PCE, girls were 2 times more likely to be rated as having delinquent behavior (OR = 2.08, 95% CI: 1.46-2.96, p < 0.0001). PCE status was also associated with increased odds of delinquent behavior (OR = 2.41; 95% CI: 1.16-4.97, p = 0.02), primarily due to the increased risk among girls with PCE. While girls with PCE status were 7 times more likely than NCE girls to have delinquent behaviors (OR = 7.42; 95% CI: 2.03-27.11, p < 0.002) boys with PCE did not demonstrate increased risk (OR = 0.98; 95% CI: 0.36-2.65, p > 0.97). Foster or adoptive parents were more likely to rate their PCE children as having more thought problems, inattention, delinquent behavior, aggression, externalizing and overall problems (p < 0.05) than biologic mothers or relative caregivers. Higher 2nd trimester tobacco exposure was associated with increased odds of caregiver reported anxiety (OR = 1.73; 95% CI 1.06-2.81, p < 0.03) and marijuana exposure increased the odds of thought problems (OR = 1.68; 95% CI 1.01-2.79, p < 0.05). Children with PCE self-reported fewer symptoms of oppositional defiant disorder (ODD) compared to NCE children (OR = 0.44, 95% CI: 0.21-0.92, p < 0.03). Greater tobacco exposure was associated with increased odds of child reported ODD (OR = 1.24; 95% CI 1.03-1.78, p < 0.03).

Conclusion

Higher PCE was associated with disruptive behaviors including aggression and delinquent behavior among girls by caregiver report, but not child report. These findings highlight the need for early behavioral assessment using multiple informants in multi-risk children.     

Genetic influences on craving for alcohol

Introduction

Craving is being considered for inclusion in the Diagnostic and Statistical Manual (DSM) DSM-5. However, little is known of its genetic underpinnings — specifically, whether genetic influences on craving are distinct from those influencing DSM-IV alcohol dependence.

Method

Analyses were conducted in a sample of unrelated adults ascertained for alcohol dependence (N = 3976). Factor analysis was performed to examine how alcohol craving loaded with the existing DSM-IV alcohol dependence criteria. For genetic analyses, we first examined whether genes in the dopamine pathway, including dopamine receptor genes (DRD1, DRD2, DRD3, DRD4) and the dopamine transporter gene (SLC6A3), which have been implicated in neurobiological studies of craving, as well as alpha-synuclein (SNCA), which has been previously found to be associated with craving, were associated with alcohol craving in this sample. Second, in an effort to identify novel genetic variants associated with craving, we conducted a genomewide association study (GWAS). For variants that were implicated in the primary analysis of craving, we conducted additional comparisons — to determine if these variants were uniquely associated with alcohol craving as compared with alcohol dependence. We contrasted our results to those obtained for DSM-IV alcohol dependence, and also compared alcohol dependent individuals without craving to non-dependent individuals who also did not crave alcohol.

Results

Twenty-one percent of the full sample reported craving alcohol. Of those reporting craving, 97.3% met criteria for DSM-IV alcohol dependence with 48% endorsing all 7 dependence criteria. Factor analysis found a high factor loading (0.89) for alcohol craving. When examining genes in the dopamine pathway, single nucleotide polymorphisms (SNPs) in DRD3 and SNCA were associated with craving (p < 0.05). There was evidence for association of these SNPs with DSM-IV alcohol dependence (p < 0.05) but less evidence for dependence without craving (p > 0.05), suggesting that the association was due in part to craving. In the GWAS, the greatest evidence of association with craving was for a SNP in the integrin alpha D (ITGAD) gene on chromosome 7 (rs2454908; p = 1.8 × 10^− 6). The corresponding p-value for this SNP with DSM-IV alcohol dependence was similar (p = 4.0 × 10^− 5) but was far less with dependence without craving (p = 0.02), again suggesting the association was due to alcohol craving. Adjusting for dependence severity (number of endorsed criteria) attenuated p-values but did not eliminate association.

Conclusions

Craving is frequently reported by those who report multiple other alcohol dependence symptoms. We found that genes providing evidence of association with craving were also associated with alcohol dependence; however, these same SNPs were not associated with alcohol dependence in the absence of alcohol craving. These results suggest that there may be unique genetic factors affecting craving among those with alcohol dependence.     

Relations between strain and gender dependencies of irinotecan toxicity and UGT1A1, CES2 and TOP1 expressions in mice

Irinotecan hydrochloride (CPT-11) can display severe toxicities in individual cancer patients. CPT-11 is bio-activated through CES, detoxified through UGT1A1 and inhibits TOP1. CPT-11 toxicity and UGT1A1, CES2 and TOP1 mRNAs and UGT1A1 protein were determined in male and female C57BL/6, B6D2F1 and B6CBAF1, as potential models for tailoring CPT-11 delivery. CPT-11 was administered intravenously (40–90 mg/kg/day for 4 days at 7 h after light onset). The relations between dose and lethal toxicity or body weight loss were steep and similar in C57BL/6 (lethality, p = 0.001; weight loss, p = 0.002) and B6D2F1 (p = 0.01; p = 0.03, respectively), but weak in B6CBAF1. Females displayed less toxicity than males (p < 0.001). Mean mRNA expression of UGT1A1 was highest in B6CBAF1 (p = 0.039) and in females (p < 0.001). Both CES2 and TOP1 varied according to strain and gender (p < 0.001). The three gene expression data explained the most severe toxicity of CPT-11 in male B6D2F1, but displayed inconsistent relations with toxicity in the other groups. Mean UGT1A1 protein expression was highest in males as compared to females, and so by ∼8-fold in C57BL/6 as compared to B6D2F1 (p < 0.0001). Genetic background and gender significantly altered the molecular prediction of irinotecan toxicity by UGT1A1, CES2 and TOP1 mRNA expressions.     

Validation of the Drinking Context Scale (DCS-9) for use with non-adjudicated first-year college students

The Drinking Context Scale (DCS-9) has been used to measure the impact of drinking during social, emotional, and situational contexts. Psychometric properties remain unevaluated in a population of non-adjudicated first-year college students in the southeast. Liseral 8.8 was used to test the factorial validity of the DCS, using Confirmatory Factor Analysis. The original three factor model for the DCS represented acceptable fit to the data (χ² = 36.72, df = 24, p = 0.047, CFI = 0.991, SRMR = .0406) supporting its use with first-year college students. Invariance between gender, ethnic group, and geographical regions should be examined by future researchers.