Biomedical subjects

C Stefanis

Publications and source records attributed to C Stefanis.

At least 19 recordsLinked to original sources

PubMed1998

A survey of bloodborne viruses and associated risk behaviours in Greek prisons.

AIMS: To determine HIV and hepatitis infection prevalence and correlates with risk behaviour. DESIGN: Cross-sectional study: voluntary, anonymous HIV, hepatitis (HCV, HBV and HDV) surveillance and questionnaire on risk factors. SETTING: Korydallos Prison, Athens and Ag. Stefanos Prison, Patra, Greece. PARTICIPANTS: Of 544 drug users imprisoned for drug related offences, all completed the questionnaire and 533 blood samples were collected. MEASUREMENTS: HIV (by anti-HIV-1), HCV (by anti-HCV), HBV (by anti-HBc, HBsAg) and HDV (by anti-HDV) prevalence. Data on demography, legal status, drug use, sharing of injecting equipment. FINDINGS: Of the 544 drug users, 375 (68.9%) had injected drugs (IDUs) at some time, 35% of whom had injected whilst in that prison. Of the 533 blood samples tested, one was positive for anti-HIV-1 (0.19%), 310 for anti-HCV (58.2%), 306/531 (57.6%) for anti-HBc, 34/527 (6.5%) for HBsAg and 12/527 (2.3%) for anti-HDV. Prevalence rates for IDUs only were 0.27% for HIV-1, 80.6% for hepatitis C, 62.7% for hepatitis B and 3.3% for hepatitis D. Ninety-two per cent of IDUs injecting in prison shared needles, indicating that IDUs inject less but share more during incarceration. Multiple logistic regression revealed needle-sharing as the most important risk factor for HCV infection in IDUs. Prior knowledge of a positive hepatitis result did not appear to inhibit IDUs from practising risky behaviours in prison. CONCLUSIONS: The epidemic of hepatitis B and C among imprisoned IDUs identified by this study constitutes a major public health problem. Prevention programmes, such as counselling, HBV vaccination, community-based methadone maintenance treatment and syringe exchange schemes, are necessary in order to prevent a further spread.

Adult↗

PubMed1996

Prolactin and TSH responses to TRH and to ECT in pre- and postmenopausal women with major depression.

The patterns of prolactin and thyrotropin (TSH) release after thyrotropin-releasing hormone (TRH) (0.4 mg i.v.) and during the first session of a course of electroconvulsive treatment (ECT) were studied in women with major depression, 16 in pre- and 29 in postmenopausal status. The prolactin responses to both stimuli were lower in postmenopausal women, whereas the TSH responses were not different. The known correlation between the maximal prolactin response to ECT and the maximal response to TRH was significantly stronger in the group of premenopausal women (r = .8648, versus .4249 in the postmenopausal group, p < .02). A common underlying mechanism promoting prolactin release for both stimuli can be suggested, which diminishes after menopause, probably an influence of estradiol on the affinity of dopaminergic and serotonergic receptors. That mechanism does not interfere with the TSH release either by ECT or by TRH.

Adult↗

PubMed1996

Effects of thyrotropin-releasing hormone administration on the electroconvulsive therapy induced prolactin responses and seizure time.

The effects of thyrotropin-releasing hormone (TRH) administration on electroconvulsive therapy (ECT)-induced prolactin (PRL) secretion and the duration of the seizure were studied in 14 depressed women. In a balanced order crossover design the patients were given 0.4 mg TRH or placebo intravenously 20 min before ECT during the first two sessions. In the third ECT session TRH was given just prior to ECT. ECT elicited the expected PRL response when given alone and when given 20 min after TRH when PRL plasma levels were high. During the coadministration design (third ECT session) PRL levels were raised not as a sum of the two stimuli but even significantly more. TRH failed to modify the duration of the seizure induced by ECT. Therefore, if TRH is involved in seizure modulation during ECT, our findings suggest a postictal rather than ictal role for TRH.

Adult↗

PubMed1996

Differential responsiveness of late passage C-6 glial cells and advanced passages of astrocytes derived from aged mouse cerebral hemispheres to cytokines and growth factors: glutamine synthetase activity.

In this study, we were interested to compare the responsiveness to growth factors, NGF, b-FGF and EGF and cytokines, IL1 beta, and TNF-alpha, in late passages (74-79) C6 glial cells committed astrocytes and astrocytes of advanced passages (26-28) in cultures derived from aged mouse cerebral hemispheres (MACH). Cultures were grown in either DMEM or chemically defined medium (CDM/TIPS) in order to test the effects of growth factors or cytokines. The activity of glutamine synthetase (GS), a marker for astrocytes, was used as a test parameter. We found that treatment with growth factors increased GS activity in both glial cell culture systems with the exception of EGF in C-6 glial cells. Treatment with cytokines markedly decreased GS activity in the late passage C6 glial cells whereas only TNF-alpha had a similar effect on MACH astrocytes. In view of the generally opposite effects of growth factors and cytokines on GS activity, we speculate that these molecules which are also endogenously present in glial cells may play a role in the maintenance of cellular homeostasis.

Animals↗

PubMed1996

Stimulation of glutamine synthetase activity by excitatory amino acids in astrocyte cultures derived from aged mouse cerebral hemispheres may be associated with non-N-methyl-D-aspartate receptor activation.

We have been using glial cells derived from aged mouse cerebral hemispheres (MACH) at several passages to study the responsiveness of astrocytes to microenvironmental signals in culture. In the present study, we examined the effects of excitatory amino acids on the activity of glutamine synthetase, a marker for astrocytes. MACH glia cell passages 25 to 29 were used. Culture groups were Dulbecco's modified Eagle's medium +10% fetal bovine serum (control); glutamate 100 microM; gamma-amino-3-hydroxy-5-methyl isoxazole-4-propionic acid (AMPA) 50 microM; kainic acid 10 microM; N-methyl-D-aspartate (NMDA) 10 microM. In all treated groups glutamine synthetase activity was significantly higher than in controls. We speculate that this increase represents an enhanced differentiation of immature astrocytes. In a second series, we examined the effects of glutamate receptor antagonists on glutamine synthetase activity as follows. MACH cultures were treated with glutamate 100 microM in combinations with either L(+)-2-amino-3-phosphonopropionic acid (L-AP3; 50 microM); D(-)-2-amino-5-phosphonopentanoic acid (D-AP5; 50 microM) or 6,7-dinitroquinoxaline-2,3-dione (DNQX, 50 microM). The increase in GS activity produced by glutamate was inhibited by the non-selective NMDA receptor antagonist, DNQX, but not by the metabotropic receptor antagonist, L-AP3 or a selective NMDA receptor antagonist, D-AP5. We also found that in cultures treated with glutamate, a number of astrocytes resembled "reactive astrocytes" morphologically. These astrocytes were absent in cultures treated with glutamate+DNQX. The findings provide supportive evidence that astrocytes from aged mouse cerebral hemispheres respond to excitatory amino acids and that this response is mediated by non-NMDA receptor activation.

2-Amino-5-phosphonovalerate↗

PubMed1996

GHQ-28 as an aid to detect mental disorders in neurological inpatients.

The prevalence of mental disorders (DSM-IIIR criteria) among 107 neurological inpatients was estimated, as well as the extent to which disorders were detected by neurologists. The validity of the scaled version of the General Health Questionnaire (GHQ-28) was evaluated using Receiver Operating Characteristic (ROC) analysis and DSM-IIIR as external criteria. Of the 107 patients who submitted to a structured psychiatric interview (SCID-R), 56 (52.3%) showed evidence of a mental disorder. Major depressive episode (n = 16), generalized anxiety disorders (n = 13) and dysthymia (n = 12) were the most frequent diagnoses. The neurologists recognized only 13/107 cases (12.1%). Significantly more women than men exhibited some form of mental disorder. The validation of GHQ-28 in the series of 107 neurological inpatients indicated that the best trade-off between sensitivity and specificity was the cut-off score of 5/6. The high occurrence of mental disorder, in association with the low rate of detection by the neurologists, points to the need for special attention to be paid to this problem by staff and experts.

Adjustment Disorders↗

PubMed1995

Acute tolerance to the excitatory effects of opioids in the rat hippocampus.

Prolonged iontophoretic administrations of delta- and mu-selective opioid receptor agonists were conducted in the hippocampus of rats, in order to study the possible development of acute tolerance to the excitatory effects of the opioids. Acute tolerance (AT) to the excitatory effects of the delta-selective opioid receptor agonist Tyr-D-Ser-Gly-Phe-Leu-Thr (DSLET) was observed when the drug was applied locally for 3-5 min in the CA1 hippocampal pyramidal neurons. The acute tolerance was expressed as a decrease in the commissurally evoked spike responsiveness during peptide's administration and led to a long-lasting potentiation of the population spike (PS) upon its withdrawal. In all cases, where AT and spike potentiation were evident, the population excitatory postsynaptic potential (pEPSP) remained unaltered. Pharmacological studies of AT and long-lasting spike potentiation showed the following: (1) the nonselective opioid receptor antagonist, naloxone, while effective in blocking the excitatory effects of DSLET when applied prior and during the application of the latter, failed to exhibit any effect on the long-lasting potentiating effect of the opioid; and (2) during the spike potentiation phase, administration of DSLET exhibited a depressant effect towards baseline values. This depressant effect of the opioid was evident 2-3 min from the beginning of the application and was completely antagonized by naloxone. The above results show that the development of acute tolerance to the excitatory effects of the DSLET led to long-lasting spike potentiation, which manifests a withdrawal phenomenon.

Analgesics↗

PubMed1995

Association of biogenic amine metabolites with symptomatology in delusional (psychotic) and nondelusional depressed patients.

1. The levels of the main norepinephrine, serotonin, and dopamine metabolite excretion in the urine, MHPG, 5HIAA and HVA respectively, were measured in 84 patients with major depressive disorder, 34 delusional (psychotic) and 50 nondelusional (DSM-III-R criteria). 2. Associations with the 17 items of the HDRS were evaluated using the multiple regression analysis model. In the delusional group, MHPG excretion was positively related to the scores in the items of depressed mood (p = 0.04), middle insomnia (p = 0.008) and genital symptoms (p = 0.001). 5HIAA excretion was negatively associated with late insomnia (p = 0.02), work and interests (p = 0.001) and genital symptoms (p = 0.007). HVA was positively related to agitation (p = 0.043). In the nondelusional group the only association found was between agitation and HVA excretion (p = 0.03).

Adult↗

PubMed1995

Patterns of alcohol consumption and related problems in the general population of Greece.

This paper focuses on patterns of alcohol consumption and related problems, based on a nation-wide home survey sample of 4290 respondents aged 12-64 years. The prevalence of lifetime, past year and past month alcohol use, as well as levels of quantity of alcohol consumed and the reported alcohol-related problems, are presented. Frequency and quantity of consumption increases as age increases. Males were found to drink alcohol more frequently and in higher quantities than females. A higher proportion of young adults reported alcohol-related problems, in comparison to the other age groups. Regional variations in the frequency of consumption of alcohol were observed. However, no differences were found in the geographic distribution of persons of all age groups reporting alcohol-related problems. Respondents of all groups with two or more alcohol related problems expressed a high number of dysphoric and depressive symptoms. Finally, a stepwise discriminant analysis revealed certain socio-demographic, familial, psychological and medical factors to discriminate optimally the "problem" and "non-problem" drinkers in both adolescent and adult age groups.

Adolescent↗

PubMed1995

Familial correlates of drug and alcohol use in a nationwide general population survey.

Familial correlates such as parental stability and past family medical history of respondents reporting recent illicit and licit unprescribed drug use or 'problematic' drinking, in a nationwide general population sample in Greece, were explored. The type of survey was cross-sectional and the respondents, aged 12-64, were interviewed in their homes with a multidimensional structured questionnaire. Familial pathology was recorded by the Family Medical History Index, an originally developed instrument. An association between familial instability and illicit or unprescribed drug use was observed. Higher levels of familial pathology expressed in the form of prevalence of mental or somatic illness, excessive tobacco smoking, alcohol and drug use was found to be related with higher rates of illicit or unprescribed drug use and 'problematic' drinking among the probands. These results are discussed within the context of the limitations of the study and the usefulness of obtaining information on the family atmosphere of drug users.

Adolescent↗

PubMed1994

Dimensionality alterations of the hippocampal electroencephalographic activity following the induction of long-term potentiation in rats.

In the present in vivo experimental study the complexity alterations of the hippocampal electroencephalographic (EEG) activity were investigated prior and during the maintenance phase of long-term potentiation (LTP), using analytical methods based on the recent concepts of deterministic chaos. LTP was induced in the hippocampal dentate hilus after stimulation of the medial perforant path of the rat's brain. During the experimental procedure hippocampal EEG epochs were recorded prior and after the induction of LTP. Dimensionality computations performed on these epochs showed a maintained relative reduction in the correlation dimension during the maintenance phase of LTP. This result might suggest that different functional states of the brain are governed by different degrees of complexity and that the altered efficacy in the information process, as it is achieved by the induction of LTP, modifies the spontaneous EEG activity of the potentiated hippocampal area in a plastic manner.

Animals↗

PubMed1994

The prognostic importance of delusions in depression: a 6-year prospective follow-up study.

The authors followed 32 delusional and 41 unipolar non-delusional depressed patients 6 years after hospital discharge. Long-term outcome, as determined by the frequency of the relapses, number of hospitalizations, chronic course of illness as well as clinical status and global functioning at the end of the 6-year period, failed to differentiate the two patient groups. Discontinuation of maintenance medication in both groups or of antipsychotics in the delusional group was associated with a high rate of relapses. Our findings indicate that delusional depression has a similar clinical course to that of non-delusional depression, underline the importance of psychoprophylactic treatment and question the efficacy of monotherapy with antidepressants in the prevention of relapses of delusional depression.

Adult↗

PubMed1994

Effects of monoamine oxidase A inhibition on plasma biogenic amine metabolites in depressed patients.

The main metabolites of noradrenalin, dopamine, and serotonin-3-methoxy-4-hydroxyphenylglycol (MHPG), homovanillic acid (HVA), and 5-hydroxyindoleacetic acid (5-HIAA), respectively--were estimated in plasma of 21 depressed patients before and after 2 and 4 weeks of treatment with the monoamine oxidase-type A (MAO-A) inhibitor moclobemide (mean final daily dose = 8.9 mg/kg body weight). The treatment caused significant mean reductions in plasma MHPG and HVA (46% and 30%, respectively), while plasma 5-HIAA was unchanged. Multiple regression analysis revealed associations between reductions in MHPG and changes on the anxiety-somatization factor of the Hamilton Rating Scale for Depression (HRSD), and between reductions in HVA and changes in the HRSD factors cognitive disturbance and retardation.

Adult↗

PubMed1994

Biogenic amine metabolites in delusional (psychotic) depression and melancholia subtypes of major depression.

1. The levels of the urinary main metabolites of norepinephrine 3-methoxy-4-hydroxyphenylglycol (MHPG), of dopamine homovanillic acid (HVA) and of serotonin 5-hydroxyindoleacetic acid (5-HIAA) were measured in 84 patients with major depressive disorder, 34 delusional and 50 nondelusional. Melancholia subtype was also defined (N = 62). 2. MHPG was significantly higher in the delusional depressed group (p = 0.023). Female patients with delusional major depression also had significantly higher HVA excretion than female patients with non delusional major depression (p = 0.036). 5-HIAA excretion was similar in the two patient subgroups. 3. No significant differences in the three monoamine metabolites were found between the melancholic and nonmelancholic depressed patients.

Biogenic Amines↗

PubMed1994

Prolactin and TSH responses to TRH and to haloperidol in schizophrenic patients before and after treatment.

The prolactin (PRL) and the TSH responses to thyrotropin releasing hormone (TRH, 0.4 mg i.v.) and to haloperidol (5 mg i.m.) were studied in 11 male schizophrenic patients in a drug-free state and after treatment with haloperidol, 60 mg daily. The PRL responses observed after i.m. haloperidol in the drug-free state, on average 35.4 ng/ml, were abolished after treatment, indicating complete receptor blockade, while the PRL responses to TRH were preserved, although moderately reduced (from 19.4 to 14.8 ng/ml on average). The TSH responses to TRH were unaltered by the treatment (means 8.25 and 7.74 mIU/l). The results show that the TSH and partially the PRL releasing actions of TRH are not mediated via receptors that are effectively blocked by haloperidol.

Adult↗

PubMed1994

Adolescent drinking and alcohol-related problems in a nationwide general population.

A sample of 1,325 adolescents drawn from a nationwide multistage probability master sample of 4,290 persons were interviewed at their homes in 1984. The purpose of this study was to investigate the patterns and quantity of alcohol consumption and related problems. Moreover, mental health status of respondents and "risk" factors were explored. Alcohol use increased from the very young to the older ones and decreased between lifetime and past week frequencies. Of adolescents, 18% reported two or more alcohol-related problems including suffering from depressive symptoms. Discriminant analysis revealed 14 predictors with high discriminating power between problematic and nonproblematic drinking.

Adaptation, Psychological↗

PubMed1993

Criminality in a sample of drug abusers in Greece.

Criminality as expressed by self-reported arrests and convictions was studied in a sample of 294 drug--mainly heroin--abusing subjects, 77.6% of whom had been arrested and 57.1% convicted. The majority had more than one arrest or conviction for a variety of crimes. Arrests and convictions for other than drug offences outnumbered the drug offences. Only a minority of the subjects were responsible for the majority of criminal acts. In half of the subjects, involvement in criminality predated initiation to heroin use. Gender, polydrug use, unemployment, low education level--not injecting heroin as main mode of use--were found to be among the main factors significantly predicting criminality.

Adult↗

PubMed1993

Evaluation of TSH and prolactin responses to TRH as predictors of the therapeutic effect of ECT in depression.

In a group of 42 unipolar depressed patients with melancholia the thyrotropin (TSH) and prolactin (PRL) responses to TRH were studied in relation to the clinical response to an ECT course. Patients were categorized as responders or nonresponders using as criterion a 50% reduction in the Hamilton Rating Scale for Depression score. Comparison between responders and nonresponders with respect to the TSH and PRL responses to TRH did not reveal any significant differences. Thus, TSH and PRL responses were not proved to have a predictive value for the therapeutic ECT response in melancholia.

Aging↗