The personality traits and social characteristics of Croatian heroin addicts and cannabis users

The purpose of this study was to investigate differences in social characteristics (level of education, working and family status, and criminal record) between heroin addicts, cannabis users and a control group. Additional goal was to explore the possibility of discerning subjects of different addiction status (of both gender) based on their scores on Eysenck Personality Questionnaire (EPQ). In comparison to the control group, heroin addicts and cannabis users had lower level of education, were more frequently unemployed and with criminal record, and more often came from dysfunctional families. In cannabis users the frequency of these characteristics was generally lower than in heroin addicts. Proportion of correct classification of subjects in groups of different addiction status based on the EPQ scores was 23.3% for males (higher than by chance alone), and 30% for females.     

Serum concentrations of macro and trace elements in heroin addicts of the Canary islands

Na, K, Ca, Mg, P, Fe, Cu, Zn and Se concentrations were determined in the serum of 106 heroin addicts and were compared with the concentrations obtained in a control group formed of 186 apparently healthy individuals. Heroin addicts displayed K and Se mean concentrations lower (p < 0.05), and Na, Mg, P mean concentrations and a Cu/Zn ratio higher (p < 0.05) than those mean values observed in the control group. The Mg and P concentrations in the serum of heroin addicts tended to normalize when age increased. The heroin addicts included in the methadone maintenance treatment program had higher serum mean concentrations of K and Mg than the heroin addicts in the detoxification process. The Na, K and Mg concentrations displayed highly significant correlations, with a different behavior for the heroin addicts group and the control group. When applying factor analysis and representing the scores of the first and second factors, the heroin addicts tended to differentiation from the control group. However, methadone substitution treatment was not able to normalize these concentrations.     

Event-related potentials in a Go/Nogo task of abnormal response inhibition in heroin addicts

Inhibitory control dysfunction is regarded as a core feature in addicts. The major objective of this study was to explore the time course of response inhibition in chronic heroin addicts and provide the neu-rophysiological evidence of their inhibitory control dysfunction. The amplitudes and latencies of ERP components were studied in fourteen heroin addicts (mean duration of heroin use being (13.54±5.71) years (Mean±SD), average abstinence being ((4.67±6.44) months)) and fourteen matched healthy con-trols with a visual Go/Nogo task. Our results showed that heroin addicts demonstrated significantly larger Go-N2 amplitudes which results in a decreased N2 Go/Nogo effect, but no statistically significant differences were found between heroin addicts and controls in P3. The ERP data suggest that fronto-central areas of heroin addicts were impaired during the inhibition process (200—300 ms) and over-activated to targets. The impaired early process might reflect an abnormal conflict monitoring process in heroin addicts. These results consolidate the inhibitory control dysfunction hypothesis in chronic heroin users.     

Failure of the gamma-aminobutyric acid (GABA) derivative, baclofen, to stimulate growth hormone secretion in heroin addicts.

In order to establish possible alterations in the gamma aminobutyric acid (GABA)ergic control of growth hormone (GH) secretion in heroin addicts, ten patients (age, 25.8 +/- 1.07 yr (mean +/- SE); duration of heroin addiction, range 3-8 yr; weight, 67.3 +/- 0.87 kg body weight), and ten age (29.1 +/- 0.84 yr)- and weight (69.7 +/- 0.87 kg)-matched normal controls were tested with the GABAergic B-receptor agonist baclofen (10 mg p.o. at 09.00 h) (experimental test) or a placebo (control test). Blood samples for GH assay were taken every 15 min for the next 150 min. Normal controls underwent one control and one experimental test. Heroin addicts were submitted to both baclofen and placebo test twice, once around the time of their admission to a recovery community for drug abusers, when they were still assuming heroin, and again after two months of permanence in the community. From the time of their admission to the community, the patients were forbidden to use heroin. For two weeks after admission they were treated with clonidine and acetylsalicilic acid to attenuate withdrawal symptoms. Thereafter, the patients underwent a period of wash-out of pharmacological treatments for at least 6 weeks before being retested. Basal GH levels were similar in normal controls and heroin addicts in all tests and remained unmodified during control tests in all subjects. The administration of baclofen increased four times the serum GH levels within 120 minutes in the normal controls, whereas it did not modify serum GH concentrations in heroin addicts either during the period of drug abuse or after two months of abstinence. These data show that the control of GH secretion mediated by GABAergic B-receptors is impaired in heroin addicts. It is hypothesized that this neuroendocrine alteration might represent a trait marker of heroin addiction, or more likely, that it was a consequence of a long addiction to heroin persisting after two months of abstinence.     

Ethnic diversity of DNA methylation in the OPRM1 promoter region in lymphocytes of heroin addicts

The μ-opioid receptor is the site of action of many endogenous opioids as well as opiates. We hypothesize that differences in DNA methylation of specific CpG dinucleotides between former severe heroin addicts in methadone maintenance treatment and control subjects will depend, in part, upon ethnicity. DNA methylation analysis of the μ-opioid receptor gene (OPRM1) promoter region was performed on African-Americans (118 cases, 80 controls) and Hispanics (142 cases, 61 controls) and these were compared with a similar Caucasian cohort from our earlier study. In controls, a higher methylation level was found in the African-Americans compared with the Hispanics or Caucasians. Significant experiment-wise differences in methylation levels were found at the −25 and +12 CpG sites in the controls among the three ethnicities. The overall methylation level of the CpG sites were significantly higher in the former heroin addicts when compared with the controls (point-wise P = 0.0457). However, in the African-Americans, the degree of methylation was significantly decreased experiment-wise in the former heroin addicts at the +12 CpG site (P = 0.0032, Bonferroni corrected general estimating equations). In Hispanics, the degree of methylation was increased in the former heroin addicts at the −25 (P < 0.001, experiment-wise), −14 (P = 0.001, experiment-wise), and +27 (P < 0.001, experiment-wise) CpG sites. These changes in methylation of the OPRM1 promoter region may lead to altered expression of the μ-opioid receptor gene in the lymphocytes of former heroin addicts who are stabilized in methadone maintenance treatment.     

Enhanced assays detect increased chromosome damage and sister-chromatid exchanges in heroin addicts

To refine previous studies of chromosome damage (CD) and sister-chromatid exchanges (SCE) in heroin addicts, we applied new methods developed in our laboratory to enhance detection of the cytogenetic effects of low-level radiation exposure in hospital workers. For CD analysis, we applied our thymidine-fluorodeoxyuridine-caffeine (TFC) enhancement procedure in which cells at setup receive 1 x 10(-7) M fluorodeoxyuridine to inhibit thymidylate synthetase and 4 X 10(-5) M thymidine to satisfy the induced requirement, and then in G2 receive 2.2 mM caffeine to modulate DNA repair. For SCE enhancement, caffeine treatment was initiated in G1 at 19 h before harvest. Using both standard and enhanced procedures for CD and SCE analysis, blood samples were evaluated from 20 street heroin addicts and 22 controls. Standard 2-day CD and 3-day SCE assays showed small, insignificant genotoxic increases in addicts while the enhanced CD and SCE assays showed highly significant increases. Most CD events were in the form of chromatid and chromosome breaks. There were no rings and only a few dicentrics were observed in the TFC-enhanced cultures. Although quadriradials are rare, 10 were found in addict TFC-cultures and 3 in control TFC-cultures. With the standard CD assay, the mean number of chromosome breaks per 100 cells was 0.727 for controls and 1.056 for addicts (not significant). With the TFC-enhanced assay, the same measure showed 1.483 chromosome breaks for controls and 5.143 for addicts (highly significant, ANOVA: p less than 0.0001). A highly significant difference was also observed for chromatid-type damage with the TFC-enhanced assay (chromatid breaks per 100 cells: 16.793 for controls; 48.191 for addicts). The SCE data also showed significant differences with the enhanced assay. Scoring 25 cells/condition, standard SCE cultures showed 10.892 SCE/cell for controls and 11.732 SCE/cell for addicts (not significant). With CAF enhancement there were 13.08 SCE/cell for controls and 17.05 SCE/cell for addicts (ANOVA: p less than 0.008). These findings indicate that detection of CD and SCE effects can be significantly enhanced by the use of these new procedures. The finding of greatly increased chromatid damage in the addicts with the TFC procedure suggests that at least part of the CD detected occurred in vitro and is not a product of prior in vivo damage. Therefore exposure to this drug and perhaps other environmental agents may not only leave a residue of DNA or chromosome damage but may also induce a sensitivity to further genotoxic damage that is revealed by using the enhanced procedures.     

Parallel increases in sister-chromatid exchanges at base level and with UV treatment in human opiate users

The SCE base level frequency and SCE levels induced by far-UV (254 nm) treatment of cells in early G1 and early S phases of the cell cycle were significantly higher in leukocytes from heroin addicts as compared to controls. The increased SCE levels in addicts was greatest at base level and smallest after UV irradiation of cells in S phase. These results corroborate and extend our previous findings of increased chromosome damage and reduced DNA-repair synthesis in heroin users. Since opiates do not directly damage DNA, the elevated cytogenetic effects associated with opiate use probably arise from secondary promotional effects related to opiate-mediated alterations in leukocyte metabolism.     

Serum Proteomic Analysis Reveals High Frequency of Haptoglobin Deficiency and Elevated Thyroxine Level in Heroin Addicts

Heroin addiction is a chronic, complex disease, often accompanied by other concomitant disorders, which may encumber effective prevention and treatment. To explore the differences in expression profiles of serum proteins in control and heroin addicts, we used two-dimensional electrophoresis coupled to MALDI-TOF/TOF, and identified 4 proteins of interest. Following validation of the increase in serum transthyretin, we assessed serum levels of thyroid stimulating hormone (TSH), triiodothyronine (T3), and thyroxine (T4), and observed a robust increase in T4 in heroin addicts compared to controls. In addition, we performed haptoglobin (Hp) phenotyping, and showed that the frequency of Hp0 (serum devoid of haptoglobin) was significantly higher in heroin addicts. Altogether, these findings indicated that: (1) thyroid hormone imbalance is present in heroin addicts; (2) anhaptoglobinemia (Hp0) might a risk factor or a deleterious effect of heroin abuse.     

HCV and HIV Infection among Heroin Addicts in Methadone Maintenance Treatment (MMT) and Not in MMT in Changsha and Wuhan,China

Objective

To compare HCV and HIV infection among heroin addicts in MMT and not in MMT in two large cities in central China.

Methods

A total of 541 heroin addicts were recruited from MMT clinics and voluntary detoxification centers in Changsha and Wuhan, China. Structured questionnaires collected data on their socio-demographics, clinical status, risk behaviors, and their knowledge of HIV. Their HIV serostatus and Hepatitis C virus (HCV) serostatus were determined by testing antibodies in blood serum.

Results

We observed a higher prevalence of HCV infection among MMT heroin addicts (82.3%) than that in the non-MMT group (50.6%). However, our findings indicated that the heroin addicts in MMT had less drug or sexual HIV/HCV risk behaviors and more knowledge about HIV than non-MMT addicts. The heroin addicts in MMT had a significantly higher percentage of individuals who always used condoms (44.9%) compared with patients in the non-MMT group (14.6%, p = 0.039), and they had more knowledge about HIV than non-MMT individuals (p<.001). The percentage of HIV-positive addicts in the MMT group (0.7%) and non-MMT group (0.8%) were almost same.

Conclusion

Our study indicated that the rate of HCV infection among heroin addicts among MMT or non-MMT settings in central China is very high. The non-MMT heroin addicts have higher risk of becoming infected with HCV in the future, while at present they have lower rates of HCV infection than MMT heroin addicts. Although rates of HIV infection among MMT and non-MMT heroin addicts are low now, they are all at great risk of becoming infected with HIV in the future, especially for non-MMT heroin addicts. We should use the MMT sites as a platform to improve the control of HCV and HIV infection in heroin addicts.     

Constitutive heterochromatin polymorphism and chromosome damage in viral hepatitis

The frequencies of chromosomal aberrations and sister-chromatid exchanges (SCEs) were scored in relation to constitutive heterochromatin in 100 patients with viral hepatitis B, 100 patients with viral hepatitis A and 100 age- and sex-matched normal controls. 23.4%, 15% and 4% of the cells showed chromosomal aberrations in patients with hepatitis B, hepatitis A and normal controls respectively. Non-random involvement of chromosomal aberrations were also noted in chromosome 1 of patients with hepatitis B and A as compared to normal controls. The frequencies of SCEs (mean +/- S.D.) were found to be 10.40 +/- 2.83 in hepatitis B and 8.70 +/- 2.34 in hepatitis A. These values were significantly higher than the SCE frequency (mean +/- S.D.) of 5.88 +/- 2.25 observed in normal controls (P less than 0.001). The intra-chromosomal distribution of SCEs revealed a relatively increased incidence of SCEs in chromosome 1 of patients with hepatitis B and A as compared to normal controls. Analysis of constitutive heterochromatin polymorphism showed chromosome 1 qh+ to be the most frequent variant in patients with hepatitis B and A as compared to normal controls. The increased involvement of C-band variant 1 qh+ in patients with hepatitis B and A as compared to normal controls may indicate that extra heterochromatin offers additional sites for viral integration.     

Increase of sister chromatid exchanges in excision repair deficient xeroderma pigmentosum

Summary The distribution of spontaneous sister chromatid exchanges (SCEs) was studied in PHA-stimulated lymphocytes from 15 patients affected by xeroderma pigmentosum (XP). The study of unscheduled DNA synthesis (UDS) in twelve of these patients showed that seven were deficient and five proficient. The number of SCEs in XP patient cells was higher than in those of 19 controls, and the distributions of SCEs per cell were significantly different. However, the results varied when XP patients were considered in relation to their UDS: the group of XP patients with proficient UDS did not differ, whereas the group of XP patients with deficient UDS was very significantly different from controls. The group not tested for UDS was similar to the deficient UDS group. The possible relationship between the increase of SCEs and the type of DNA repair defect is discussed.     

SCE frequencies in lymphocytes of systemic lupus erythematosus patients

The frequency of sister-chromatid exchanges (SCEs) was investigated in peripheral lymphocytes of lupus erythematosus patients and compared with values obtained for healthy controls. Irrespective of the kind of medical treatment, an increased level of spontaneously occurring SCEs could be demonstrated in lupus patients. In addition to spontaneously occurring SCEs, mitomycin C (MMC)-induced SCEs were evaluated. No difference between patients and controls was found with respect to MMC-induced SCEs.     

Biomarkers in styrene-exposed boatbuilders.

14 fiberglass-reinforced plastics (FRP) boatbuilders were compared with 9 unexposed controls with respect to several chemical specific and nonspecific biomarkers measured in peripheral blood. Biomarkers included styrene-hemoglobin adducts (styrene-Hb), sister-chromatid exchanges (SCEs), micronuclei (MN), single-strand breaks (SSBs) and N-acetoxy-2-acetylaminofluorene-induced DNA binding (NA-AAF binding) as a measure of susceptibility to DNA damage. Workers' exposures averaged 11 ppm (8-h TWA; geometric mean) and ranged from 0.6 to 44 p.p.m. Mandelic acid levels were measured in end-of-shift urine samples and reflected an average styrene exposure equivalent to 15 p.p.m. There was a large though not significant difference in levels of styrene-Hb adducts among exposed workers and controls, largely the consequence of a single heavily-exposed individual with an extremely high level of adducts. Significant differences between biomarker levels in exposed workers and controls were observed with MN, SSBs and NA-AAF binding. No significant differences were seen in mean levels of SCEs nor in the incidence of cells with a high frequency of SCEs. The data suggest that exposure to levels of styrene in occupational settings near or below the current OSHA standard (50 p.p.m.) can induce damage at the cellular/molecular level. Appropriately-selected panels of biomarkers can be useful in identifying potentially harmful exposures.     

Clonidine improved laboratory-measured decision-making performance in abstinent heroin addicts

Background

Impulsivity refers to a wide spectrum of actions characterized by quick and nonplanned reactions to external and internal stimuli, without taking into account the possible negative consequences for the individual or others, and decision-making is one of the biologically dissociated impulsive behaviors. Changes in impulsivity may be associated with norepinephrine. Various populations of drug addicts all performed impulsive decision making, which is a key risk factor in drug dependence and relapse. The present study investigated the effects of clonidine, which decreased norepinephrine release through presynaptic alpha-2 receptor activation, on the impaired decision-making performance in abstinent heroin addicts.

Methodology/Principal Findings

Decision-making performance was assessed using the original version of Iowa Gambling Task (IGT). Both heroin addicts and normal controls were randomly assigned to three groups receiving clonidine, 0, 75 µg or 150 µg orally under double blind conditions. Psychiatric symptoms, including anxiety, depression and impulsivity, were rated on standardized scales. Heroin addicts reported higher scores on the Barratt Impulsiveness Scale and exhibited impaired decision-making on the IGT. A single high-dose of clonidine improved the decision-making performance in heroin addicts.

Conclusions/Significance

Our results suggest clonidine may have a potential therapeutic role in heroin addicts by improving the impaired impulsive decision-making. The current findings have important implications for behavioral and pharmacological interventions targeting decision-making in heroin addiction.     

Induction of sister-chromatid exchanges in ICR 2A frog cells exposed to 265-313 nm monochromatic ultraviolet wavelengths and photoreactivating light

Exposure of ICR 2A frog cells to 265 nm, 289 nm, 302 nm or 313 nm monochromatic ultraviolet (UV) wavelengths induced the formation of sister-chromatid exchanges (SCEs). However, treatment of cells with photoreactivating light (PRL) following the UV irradiations resulted in a lower level of SCEs compared with cells incubated in the dark. Hence, it can be concluded that pyrimidine dimers are the principal photoproducts responsible for the induction of SCEs in cells exposed to 265-313 nm UV due to the specificity of DNA photolyase for the light-dependent monomerization of dimers in DNA. It was also found that the maximum yield of induced SCEs in 313 nm-irradiated cells was only about 7 SCEs per cell whereas the plateau values for the shorter wavelengths were approximately 15-20 SCEs per cell. In addition, treatment of cells with 313 nm plus 265 nm light resulted in a lower level of SCEs than in cells exposed to 265 nm UV alone. These results can be interpreted in the context of a replication model for SCE, in which the high level of non-dimer damages produced in the DNA of 313 nm-irradiated cells inhibits the induction of SCEs by the pyrimidine dimers that are also produced by this wavelength.     

Assessment of DNA damage in women using oral contraceptives

The effect of the use of an oral contraceptive (OC) on the frequency of sister chromatid exchanges (SCEs) and on the response in the alkaline comet assay (single-cell gel electrophoresis (SCGE)) was investigated in 18 women taking contraceptive pills daily for 24 months. As controls, fertile women were included with regular menstrual cycles who received no OC drugs. A significant increase in the number of lymphocytes with DNA migration and an increased frequency of SCE per metaphase were observed in OC users as compared with their age-matched untreated controls (P<0.005). As higher incidences of spontaneous SCEs in peripheral blood lymphocytes have been reported to occur in females during pregnancy due to profound changes in the levels of certain sex hormones such as progesterone and estrogen, particularly during the last trimester, 17 pregnant women served as positive controls in this study in order to test the rate of genetic damage due to those changes. Higher frequencies of SCEs and comet responses were observed in pregnant women than in their matched controls. However, no statistically significant difference in DNA damage was observed between OC users and pregnant women (P>0.05). This study underscores the fact that prolonged and extensive use of these drugs in our daily life may be hazardous and also, that OC users should be aware of multifactorial risk factors (environmental, genetic and life style patterns) that may be responsible for additional DNA damage.     

Cytogenetic studies on blood lymphocytes from patients with Schistosoma mansoni

Chromosomal aberrations and sister chromatid exchange (SCE) frequencies were studied in peripheral blood lymphocytes from 10 patients with Schistosoma mansoni prior to initiation of chemotherapy. The mean frequencies of chromatid and chromosome breaks for the patients were 1.80 and 2.30%, respectively, which were significantly higher (P less than 0.01) than the means 0.35 and 0.30%, scored for 20 healthy controls. Significant increase in the mean frequency of SCEs in the patients (9.1 +/- 0.5 SCE/cell) was noticeable when compared with the controls (6.2 +/- 0.1 SCEs/cell). Reductions in the lymphocyte divisions and replications in the patients were also observed. These results indicate that infection with S. mansoni could have in vivo mutagenic effects on human chromosomes.     

Sister-chromatid exchanges in lymphocytes of workers at a phosphate fertilizer factory

The frequencies of sister-chromatid exchange (SCE) in peripheral blood lymphocytes of 40 workers at a phosphate fertilizer factory in North China were studied. HF and SiF₄ are main air pollutants in the factory, there is also some dust containing fluoride, phosphate fog, NH₃ and SO₂. It was shown that the chemicals caused an increase in SCE, and also induced cell mitotic delays. The mean SCEs/cell of the workers and the non-exposed controls were 7.47 ± 0.31 and 4.94 ± 0.14 (p < 0.01) respectively. SCEs/cell in 75% of 40 workers were higher than 6 while 40 controls all had values lower than 6. SCE frequencies of the workers increased with length of the chemical exposure period up to 10 years. Smoking enhanced the SCE frequencies induced by the chemicals.     

Loss of Protein Kinase C-αβ in Brain of Heroin Addicts and Morphine-Dependent Rats

Abstract: The biochemical status of human brain protein kinase C (PKC)-αβ during opiate dependence was studied by means of immunoblotting techniques in postmortem brain of heroin addicts who had died by opiate overdose. In the frontal cortex, a marked decrease (53%, p < 0.05) in the immunoreactivity of PKC-αβ was found in heroin addicts compared with matched controls. The loss of PKC-αβ in the brain of human addicts paralleled that observed in the frontal cortex of rats after chronic treatment with morphine (10–100 mg/kg i.p. for 5 days) (PKC-αβ decreased by 34%, p < 0.05). Chronic treatment with naloxone (1 mg/kg i.p. every 12 h for 5 days) did not alter PKC-αβ immunoreactivity in the rat brain. However, in morphine-dependent rats, naloxone-precipitated withdrawal induced a rapid and strong behavioral reaction with a concomitant up-regulation of PKC-αβ immunoreactivity to control values. These results indicated that the decrease of brain PKC-αβ induced by heroin/morphine is a μ-opioid receptor-mediated effect. The chronic administration of opiates has been associated with a marked sensitization of the adenylyl cyclase/cyclic AMP system, although this phenomenon is not exclusive of the opioid system but the general cellular adaptation to chronic inhibition of adenylyl cyclase. In this context, chronic treatment of rats with other inhibitory agonists (e.g., clonidine, 1 mg/kg i.p. every 12 h for 14 days) acting through receptors (e.g., α₂-adrenoceptors) also coupled to adenylyl cyclase did not alter brain PKC-αβ immunoreactivity. Together these findings suggest that the brain PKC system might play a major role in opiate addiction.