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Biomedical subjects

L Palego

Publications and source records attributed to L Palego.

25 records · Page 2Linked to original sources

Platelet markers in suicide attempters.

1. The authors measured 3H-imipramine (3H-IMI) binding and serotonin (5HT) uptake parameters as well as sulphotransferase activity in platelets of suicide attempters. 2. Platelet 3H-IMI binding sites and 5HT uptake are related to similar sites and processes present in the brain, and sulphotransferase (ST) is an enzyme involved in the catabolism of cathecholamines. 3. The results showed the presence of a decreased density of both 3H-IMI binding and of 5HT uptake sites, with no change in ST activity in suicide attempters, as compared with healthy controls. 4. The reduced 3H-IMI binding and 5HT uptake may be related to a hypofunction of presynaptic serotonergic mechanisms which might be altered in suicidal behavior.

Adolescent↗

Human platelet sulfotransferase shows seasonal rhythms.

Our study aimed to investigate the possible presence of seasonal changes in platelet phenolsulfotransferase (ST) in a group of 20 healthy, drug-free subjects of both sexes between 24 and 37 years of age. Blood samples were taken four times a year in the period immediately following the equinoxes and the solstices. The results showed that both Sts underwent seasonal changes: the lowest values were found in autumn and in winter, and the highest in the summer. A positive correlation between the two STs and the length of the photoperiod was observed in winter whereas in the spring we detected a negative correlation between the TL ST and the photoperiod length. Future studies should clarify whether platelet ST of patients with mood disorders shows a similar seasonality.

Adult↗

Localization and gene expression of serotonin 1A (5HT1A) receptors in human brain postmortem.

We investigated the binding parameters, i.e. the maximum binding capacity (Bmax) and the dissociation constant (Kd), of [3H]8-hydroxy-2-(di-N-propylamino)tetralin ([3H]8-OH-DPAT) labeling the serotonin receptor of the 1A type (5HT1A), and the distribution of the mRNA encoding it in some human brain areas obtained from autoptic samples. The results showed that the Bmax was significantly higher in the hippocampus than in the prefrontal cortex and the striatum, while the Kd had the inverse, although not significant, pattern. The expression study revealed that 5HT1A mRNA distribution in the hippocampus and prefrontal cortex was consistent with the data of the [3H]8-OH-DPAT binding. A different result was obtained in the striatum where no 5HT1A mRNA expression was detected, despite the measurement of specific [3H]8-OH-DPAT binding. These findings underline the different nature of [3H]8-OH-DPAT binding sites in different brain areas and the need for further studies on 5HT receptor gene expression in human brain.

Aged↗

Platelet 3H-imipramine binding and sulphotransferase activity in primary headache.

We investigated platelet 3H-imipramine (3H-IMI) binding, a putative peripheral serotonergic marker, and the activity of sulphotransferase (ST), an enzyme involved in the catabolism of catecholamines and phenolic compounds, in 14 patients suffering from migraine without aura (MWoA) and in 10 with tension-type headache (TH), as compared with a group of controls. The possible relationships between the biological parameters and clinical features were also examined. The results showed that the two groups of patients had a lower number of 3H-IMI binding sites and a lower activity of the thermolabile form of ST, which acts preferentially on monoamine substrates, than the healthy controls, with no intergroup differences. Significant correlations between psychopathological rating scales and characteristics of the illness were observed in the patients with TH. The decreased number of platelet 3H-IMI binding sites is suggestive of a presynaptic serotonergic dysfunction and confirms the involvement of 5HT in primary headaches. The reduced ST activity might produce changes in the level of sulphated biogenic amines, including dopamine and tyramine, which might have an additional role in the pathophysiology of some aspects of primary headache.

Adolescent↗

Immune cell imbalance in major depressive and panic disorders.

We investigated subsets of peripheral immunologic cells in 12 drug-free patients affected by major depression according to DSM-III-R criteria, and who had recent evidence of somatic diseases. They were compared with 10 drug-free depressives, with 10 patients with panic disorder, and with 12 healthy volunteers, all without somatic disease. The immune subsets were measured by flow cytometry. The results showed that both groups of depressives had the same abnormalities in immune cells compared with the healthy volunteers or the panic disorder patients; in particular they presented a lower number of CD3+, CD8+ and HLA-DR+. The patients with panic attacks did not differ from healthy controls, except for CD4+ cells which were significantly lowered, even in comparison with the depressive groups. These data, although preliminary and in a small sample, suggest that some immune parameters may be influenced by the presence of a major psychiatric disorder.

Adolescent↗