Publications by authors named "Y I Malidelis"

In the rat, experimental manipulations that cause activation of the magnocellular neurosecretory neurones result in the synthesis, in addition to vasopressin (AVP) and oxytocin (OXY), of other neurotransmitters or peptides, including tyrosine hydroxylase (TH), the first and rate limiting enzyme for catecholamine biosynthesis. In the human neonate, our previous study showed that TH was selectively increased in AVP neurones of subjects that died from prolonged perinatal hypoxia. The purpose of the present study was to quantitatively investigate the expression of TH, AVP, OXY and neurophysin in magnocellular neurones of the human neonate in relation to the severity/duration of perinatal hypoxia, as estimated by neuropathological criteria.

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The purpose of this study was to determine whether the increased expression of tyrosine hydroxylase (TH), the first and limiting enzyme in catecholamine synthesis in vasopressin (VP) neurons of the human neonate, represents a primary developmental phenomenon or reflects a secondary phenomenon related to the activation of VP systems due to perinatal hypoxia. Using immunohistochemistry, we investigated TH expression in the supraoptic nucleus (SON) of 15 human neonates at autopsy in relation to the age and severity/duration of hypoxic injury that was estimated on the basis of neuropathological criteria. Increased expression of TH was observed selectively in VP-synthesizing neurons of neonates who experienced prolonged perinatal hypoxia; was not related to the age, body weight/percentile, brain weight, or head perimeter of the subjects but depended on the neuropathological grade of the hypoxic injury (p < 0.

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Dysfunction in water intake and metabolism has frequently been reported in schizophrenia. The general population of schizophrenics under neuroleptic treatment secretes lower amounts of vasopressin than controls at comparable values of plasma osmolality. The purpose of the present study was to investigate the synthetic activity of vasopressin neurons of the dorsolateral supraoptic nucleus in schizophrenia on postmortem material using a battery of histochemical activity markers.

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Previous studies indicated that in the human paraventricular nucleus (PVN) and in the supraoptic nucleus (SON) tyrosine hydroxylase (TH) - the first and rate-limiting enzyme in catecholamine synthesis - is localized mainly in magnocellular neurosecretory neurons. Individual differences were observed among control subjects in number and distribution of TH-immunoreactive (IR) perikarya, indicating that antemortem factors may regulate TH expression. Since a large number of TH-IR perikarya were observed in subjects who suffered from somatic illnesses leading to prolonged osmotic or nonosmotic stimulation of vasopressin (VP) release, we suggested that TH expression is related to the activation of VP neurons.

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Our previous studies indicated that in the human paraventricular (PVN) and supraoptic (SON) nuclei, tyrosine hydroxylase (TH)--the first and rate-limiting enzyme in catecholamine synthesis--is localized mainly in magnocellular neurons and that antemortem factors regulate its expression. The purpose of the present study was to investigate the distribution of TH-immunoreactive (TH-IR) perikarya of the hypothalami of a large sample of well-documented adult subjects without neurological, psychiatric or endocrinological disease in order to identify factors that could regulate the expression of TH in the human neurosecretory neurons. Our material consisted of the hypothalami of 38 subjects studied immunohistochemically for TH using the peroxidase-antiperoxidase method.

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