Clozapine and desmethylclozapine: correlation with neutrophils and leucocytes counting in Mexican patients with schizophrenia.

Purpose: The aim of present study is to measure plasma clozapine (CLZ) and N-desmethyl clozapine (DMC) as biomarkers to correlate drug concentrations with the appearance of preclinical adverse hematic effects.

Methods: A high-performance liquid chromatographic method, using a diode-array (ultraviolet) detector, was validated to obtain reliable concentrations of CLZ and DMC, its main metabolite, in plasma of 41 schizophrenic patients taking CLZ. Blood neutrophils and leucocytes counting were concurrently assessed as a proxy to subclinical adverse reactions.

Ultrastructural changes and immunolocalization of P-selectin in platelets from patients with major depression.

Depression is considered an important risk factor in patients with cardiovascular disease (CVD). Although the biological mechanism is unknown, it has been suggested that hyperactivity of platelets may have an important role in the onset and evolution of cardiovascular damage. The goals of this study were to evaluate by transmission electron microscopy and immunohistochemistry the presence of ultra-structural variations in platelets from individuals with recent diagnosis of major depression disease (MDD, patients without previous anti-depressant treatment and from healthy control subjects.

Auditory brainstem responses as a clinical evaluation tool in children after perinatal encephalopathy.

Unlabelled: Auditory brainstem responses (ABR) reveals the neurophysiological status of the neural axis. In this study we compared the ABR of healthy children, under 1-year-old, with children who suffered from perinatal encephalopathy (PE).

Objective: The purpose of this study was to characterize the ABR differences between children with PE and healthy children in order to identify groups with specific neurophysiological profiles, associated with their neurological condition.

Methodologic pitfalls in measurement of 5-hydroxytriptamine uptake transporters in human platelets by [3H]-paroxetine binding assay.

Background: Studies in platelet of 5-HT uptake transporters have been performed using binding assay methodology designed for ligand-receptor interactions; however, uptake transporters present requirements that may question the validity of these particular binding assays.

Methods: To explore methodologic aspects that may be crucial to the validity of these assays, we studied the binding of [3H]-paroxetine to platelet membranes of healthy subjects under different conditions of time, temperature, and protein concentrations.

Results: A correlation between protein concentration in incubation media and percentage of specific binding of [3H]-paroxetine was found: the lower the protein concentrations (10 and 20 microg/mL) in incubation media, the lower the percentage of specific [3H]-paroxetine binding.

Diurnal variations of extrapyramidal symptoms induced by haloperidol in schizophrenic subjects.

Despite the fact that the circadian variations in the density of striatal dopaminergic D2 receptors are well documented, there are few reports concerning whether these variations may regulate the extrapyramidal symptoms produced by antipsychotic drugs. To test this hypothesis, we selected 18 male hospitalized schizophrenic subjects, who had been treated for 2 wk with 10 mg haloperidol three times a day. The extrapyramidal symptoms were evaluated 1 h after each haloperidol administration (e.