Roberto Delsignore

Neurotransmitter-neuroendocrine responses to experimentally induced aggression in humans: influence of personality variable

Aggressiveness was experimentally induced in 30 psychophysically healthy male subjects, 18-19 years old, divided into 15 cases with low normal and 15 with high normal basal aggressivity. Plasma norepinephrine (NE), epinephrine (EPI), growth hormone (GH), prolactin (PRL), cortisol (CORT) and testosterone (Te) concentrations were measured in basal conditions and during experimentally induced aggressiveness. Basal Te and stimulated NE, GH and Cort levels were higher in subjects with high-normal than in those with low-normal aggressiveness, suggesting that the functional tonus of the NE system and of the NE-dependent hormonal axes might be a modulator of the behavioral parameter.

Neurotransmitters, neuroendocrine correlates of sensation-seeking temperament in normal humans.

Correlations between sensation-seeking (SS) personality dimension and plasma concentrations of norepinephrine (NE), epinephrine, and NE-dependent testosterone (T), cortisol and prolactin (PRL) were studied in 74 physically and psychologically healthy male volunteers, in order to see whether or not the noradrenergic system is involved in the modulation of this personality trait. Novelty-seeking scores by the Temperament and Character Inventory and SS scores on a Visual Analog Scale were positively correlated with plasma NE, T and PRL levels, suggesting that NE and the downstream cascade of NE-dependent hormones, together with other monoaminergic changes, might be responsible for the development and the degree of this temperamental character.

Clonidine and opiate receptor antagonists in the treatment of heroin addiction

Good results in detoxification methods have been reached using both together clonidine and opiate receptors antagonists. One hundred fifty-two heroin-abusing patients were studied evaluating withdrawal symptoms after therapy with (a) clonidine only, (b) clonidine and naltrexone, (c) clonidine and naloxone, and (d) placebos. Treatment results, emotional and behavioral changes, and involvement in psychosocial programs were evaluated after a 6-month follow-up. Although opiate antagonists were able to induce slight and transient withdrawal signs and symptoms, there was, in the group of patients treated with clonidine and naltrexone together, a low percentage of catabolites in urine and an improvement in mood and family relationships. Furthermore, the patients that underwent longer naltrexone treatment showed a stronger involvement in psychosocial programs, and even their relatives demonstrated more interest in the recovery program. A decrease in the difficulties of accepting an opiate antagonists treatment and a different evaluation of withdrawal syndrome were the results of an early use of naltrexone.

Regional cerebral blood flow and comorbid diagnosis in abstinent opioid addicts.

Studies using single photon emission computed tomography (SPECT) have found low cerebral blood flow (CBF) in frontal and parietal cortices in patients with chronic opiate dependence. In the present study, SPECT with 99mTc-HMPAO as tracer was used to compare 27 detoxified opiate addicts with nine healthy control subjects. All the subjects were evaluated with clinical psychiatric (DSM-IV), psychometric and neuropsychological measures. Compared with normal control subjects, the addicts showed a non-significant reduction of whole brain perfusion values. Significant hypoperfusion in the right frontal and left temporal lobes was found in addicts with comorbid depression, and a significant decrease in CBF in the right frontal lobe was observed in those with antisocial tendencies. A significant negative correlation emerged between Depression subscale scores on the Minnesota Multiphasic Personality Inventory and left temporal CBF in the patients. No significant correlations were found, however, between measures of cognition and CBF in opiate addicts. The asymmetrical findings in CBF that characterized the addicts relative to normal control subjects may be more closely related to mood and behavioral traits than to substance abuse, per se.

Effects of fluoxetine and ca-acetyl-homotaurinate on alcohol intake in familial and nonfamilial alcoholic patients

Abstract We evaluated the ability of fluoxetine, an inhibitor of serotonin up-take, and Ca-acetyl-homotaurinate, a GABAergic derivative of taurine, to counteract ethanol intake in familial and nonfamilial alcoholic patients. Fluoxetine, homotaurinate, or placebo were administered for 1 month each, in random order, to both groups of patients. The mean number of alcoholic drinks were measured during the 2 weeks before treatment (baseline) and during the 3 months of treatment. The nonfamilial alcoholic patients showed a slight response to fluoxetine; however, the mean number of alcoholic drinks significantly decreased ( P P

Neuroendocrine Responses to Emotional Arousal in Normal Women

The neuroendocrine effects of many stressful challenges and experimentally induced emotional states have been investigated in humans, but few data are available concerning the psychobiological correlates of the emotional arousal induced by TV violence, fear and conflictual emotions. In this study we evaluated cardiovascular, hormonal and mood changes induced by the view of a violent or, in random order, neutral movie in 20 healthy young women. The emotional arousal was associated with a significant increase in heart rate, systolic blood pressure and significant changes in self-evaluated mood states. beta-Endorphin, adrenocorticotrophic hormone, epinephrine and growth hormone showed a significant increase during emotional arousal, with a significant interaction mood-time. Cortisol increased significantly during the violent movie (areas under curves analysis), but not significant interaction mood-time has been demonstrated. Prolactin and norepinephrine levels did not show a significant change during the emotional stimulus. Our data evidence the existence of neuroendocrine changes associated with the defence mechanism and aroused by movie violence and conflictual situations.

Rapid opiate detoxication in outpatient treatment. Relationship with naltrexone compliance

A variety of detoxification methods have been utilized for the treatment of heroin withdrawal before individuals begin long-term opiate-free and naltrexone programs. While methadone in decreasing doses is still widely used for detoxication procedures, rapid and ultrarapid protocols including clonidine and opiate receptors antagonists have been proposed. This study compares the efficacy of different detoxification methods and investigates possible changes in naltrexone compliance. Ninety-eight heroin-addicted individuals were studied to evaluate withdrawal symptoms, craving, mood, urine toxicologic screens, and drop-out rate during therapy with: Group A: clonidine only (5 days); Group B: clonidine, oxazepam, baclofen, and ketoprofene with naloxone and naltrexone (2 days); and Group C: methadone in decreasing doses (10 days). Naltrexone compliance and relapse rates were evaluated during a 6-month follow-up period. Rapid detoxification with opiate antagonists (Group B) induced slight and transient withdrawal symptoms, and resulted in a significantly lower percentage of heroin catabolites in urine controls during the detoxification procedure, lower negative and positive craving, less mood problems, and higher compliance in extended naltrexone treatment. In comparison with clonidine only (Group A) and methadone (Group C), the early use of naltrexone during detoxification in combination with benzodiazepines and clonidine facilitated extended naltrexone acceptance and improved the recovery outcome in outpatients.

Effects of (±) 3,4-methylene–dioxymethamphetamine (ecstasy) on dopamine system function in humans

Twelve (+/-) 3,4-methylenedioxymethamphetamine (MDMA) users, who did not show other drug dependencies or prolonged alcohol abuse (group A), and 12 control subjects (group B) were included in the study. Prolactin (PRL) and growth hormone (GH) responses to the dopaminergic agonist bromocriptine (BROM) and psychometric measures were evaluated 3 weeks after MDMA discontinuation. PRL decreased both in A and B subjects after BROM suppression, without any significant difference between the two groups. PRL responses to BROM in MDMA users were in the normal range. In contrast, GH responses to BROM stimulation were found significantly reduced in ecstasy users, in comparison with control subjects (P < 0.001; F = 6.26). MDMA users showed higher scores on the Novelty Seeking (NS) scale at the Three dimensional Personality Questionnaire (TPQ), on direct aggressiveness subscale at Buss Durkee Hostility Inventory (BDHI), on subscale D (depression) at Minnesota Multiphasic Personality Inventory (MMPI 2) and on Hamilton Depression Rating Scale (HDRS) than control subjects. PRL areas under the curves (AUCs) showed a significant inverse correlation with NS scores both in A and B subjects. GH AUCs directly correlated with NS scores in healthy subjects, but not in MDMA users. No other psychometric measure correlated with hormonal responses. GH AUCs were inversely correlated with the measures of MDMA exposure (r = -0.48; P < 0.01). Lower GH response to BROM in A subjects (MDMA users) could reflect reduced D2 receptor sensitivity in the hypothalamus, possibly due to increased intrasynaptic dopamine concentration. Although the hypothesis of dopaminergic changes associated with a premorbid condition cannot be completely excluded, the inverse correlation between DA receptors sensitivity and the extent of ecstasy exposure may suggest a direct pharmacological action of MDMA on brain dopamine function in humans.

Lofexidine versus clonidine in rapid opiate detoxification

The aim of the present study is to evaluate lofexidine and clonidine, in an accelerated opiate detoxification procedure (3 days), without anaesthesia. Forty heroin-dependent individuals were detoxified, evaluating withdrawal symptoms, craving levels, mood changes, urine toxicologic screens, and dropout during therapy with either (1) clonidine, oxazepam, baclofen, and ketoprofene, with naloxone and naltrexone for 3 days (20 subjects) or (2) lofexidine, oxazepam, baclofen, and ketoprofene with naloxone and naltrexone for 3 days (20 subjects). Both clonidine and lofexidine rapid detoxifications were found effective. The subjects treated with lofexidine showed significantly lower levels of withdrawal symptoms, fewer mood problems, less sedation and hypotension. No significant differences in craving levels, morphine metabolites in urine, or dropout rate were evidenced between the two groups. The early use of naltrexone during detoxification in combination with either alpha-2-agonist facilitated the acceptance for long-term naltrexone treatment. Lofexidine appeared to be more useful than clonidine in a 3-day accelerated opiate detoxification, not only to counteract withdrawal symptoms, but also in the treatment of dysphoria and mood changes. Because lofexidine does not produce hypotension, safe outpatient treatment, without hospital support, could be possible.

Impact of XIAP protein levels on the survival of myeloma cells

XIAP is the best characterized and the most potent direct endogenous caspase inhibitor and is considered a key actor in the control of apoptotic threshold in cancer cells. The results of this study demonstrate that a decrease in XIAP level in myeloma cells shifts the balance toward apoptosis. Background XIAP is the best characterized and the most potent direct endogenous caspase inhibitor and is considered a key actor in the control of apoptotic threshold in cancer cells. In this report, we specifically addressed XIAP regulation and function in myeloma cells. Design and Methods XIAP and its endogenous inhibitor XAF-1 protein levels and their regulation were assessed by immunoblot analysis in myeloma cell lines or primary myeloma cells. XIAP knockdown by RNA interference was used to evaluate XIAP impact on in vitro drug sensitivity and in vivo tumor growth. Results Our results indicate that myeloma cells expressed high levels of XIAP protein that were tightly regulated during growth factor stimulation or stress condition. Of note, an increased XIAPlevel was evidenced during the blockade of the canonical cap-dependent translation by the mTOR inhibitor rapamycin, supporting the hypothesis of a functional IRES sequence in XIAP mRNA. In addition, caspase-mediated XIAP cleavage correlated to an apoptotic process occurring upon cell treatment with the proteasome inhibitor bortezomib. Importantly, XIAP knockdown using RNA interference enhanced drug sensitivity and decreased tumor formation in NOD/SCID mice. Finally, myeloma cells also expressed the XIAP inhibitor XAF-1 that interacted with XIAP in viable myeloma cells. Conclusions Altogether, our data argue for a delicate control of XIAP function in myeloma cells and stimulate interest in targeting XIAP in myeloma treatment.