Vera Folnegović-Šmalc

Vitamin C status in chronic schizophrenia

Schizophrenic patients on the same hospital diet as control group subjects had significantly lower levels of fasting plasma vitamin C (p less than 0.05) and 6-hr urinary vitamin C excretion after an ascorbic acid load test (p less than 0.01). After administration of 70 mg of ascorbic acid for 4 weeks there was no longer any difference in plasma vitamin C levels between schizophrenics and control group subjects, but the urinary vitamin C excretion after the vitamin C loading test remained significantly lower in schizophrenics (p less than 0.05). The administration of 1 g ascorbic acid for 4 weeks, in addition to eliminating differences in the plasma vitamin C level, also increased the urinary vitamin C excretion of schizophrenic patients to the level of the control group subjects. The results of this study are in agreement with the hypothesis that schizophrenic patients require higher levels of vitamin C than the suggested optimal ascorbic acid requirement for healthy humans.

Physiological characteristics of platelet/circulatory serotonin: study on a large human population.

The aim of this work was the study of platelet/circulatory serotonin (5-hydroxytryptamine, 5-HT), specifically alternative ways of its measurement and main physiological characteristics. The study was performed on a large human population (N=500) of blood donors of both sexes over the course of a longer time period (17 months). Owing to the heterogeneity in measurement of circulatory serotonin encountered in the literature, three ways of expression were comparatively studied: per unit number of platelets, per unit mass of platelet protein and per unit volume of whole blood. Results demonstrated unimodal distribution of individual frequencies of platelet/circulatory serotonin in the human population with the mean values of 579+/-169 ng 5-HT/10(9) platelets; 332+/-89.9 ng 5-HT/mg protein and 130+/-42.3 ng 5-HT/ml blood (mean+/-S.D.). A progressive decrease of serotonin level with age (18-65 years) was demonstrated, reaching statistical significance between the extreme age groups. No significant differences in the serotonin level between the sexes were observed. No seasonal oscillations in platelet/circulatory serotonin were found. Platelet serotonin demonstrated intra-individual stability over time. Finally, regarding the methodology of measurement, our results demonstrated a good correlation among the above-mentioned ways of expression of platelet/circulatory serotonin. This indicates the possibility of intercomparison of the literature reports expressing this physiological parameter either as 5-HT concentration in platelets or as 5-HT level in the circulation.

Repeated Assessments of Endocrine- and Immune-Related Changes in Posttraumatic Stress Disorder

Objective: It is assumed that stress-related changes in the endocrine and immune systems are key mediators involved in the development of diseases associated with posttraumatic stress disorder (PTSD). Evidence suggests that those changes might be related to the duration of PTSD. The aim of our study was to investigate the differences in selected endocrine- and immune-related variables between PTSD patients and control subjects, and whether these differences persist over time. Methods: We assessed 39 Croatian war veterans with PTSD and 25 healthy volunteers (civilians without traumatic experience), all men, at two time points separated by 5.6 years (median; interquartile range: 5.4–6.3). Cortisol and prolactin levels were measured by radioimmunoassays while interleukin-6 and tumor necrosis factor-α were determined by enzyme-linked immunosorbent assays. Immune function was assessed by in vitro natural killer cell cytotoxicity (NKCC). Lymphocyte counts, immunophenotype and intracellular glucocorticoid receptor expression in various lymphocyte subsets were determined by three-color flow cytometry. Results: At the first assessment, moderate to large effect size estimates of differences between patients and controls were observed for most of the measured variables. Only prolactin levels and lymphocyte counts remained significantly elevated in PTSD patients at the second assessment with low to moderate effect size estimates of differences between patients and controls in other variables. Conclusion: Observed endocrine- and immune-related changes in PTSD over time may depend on the duration of the allostatic load posed by the disorder and its impact on interactions between the endocrine and immune systems involved in stress response.

Platelet serotonin concentration and monoamine oxidase type B activity in female patients in early, middle and late phase of Alzheimer's disease

Alzheimers disease (AD) is a progressive, neurodegenerative disorder with unclear aetiology. Cognitive impairment in AD might be associated with altered serotonergic system. The aim of the study was to determine platelet serotonin (5-HT) concentrations and platelet monoamine oxidase type B (MAO-B) activity in patients with different severity of AD. Platelet 5-HT concentrations and MAO-B activity were determined spectrofluorimetrically in 74 female patients with AD (NINCDS-ADRDA, DSM-IV-TR criteria), subdivided according to the Mini Mental State Examination (MMSE) scores in three groups with a) 23 patients in early (MMSE scores 19-24), b) 23 patients in middle (MMSE 10-18), and c) 28 patients in late (MMSE 0-9) phase of AD, and in 49 age-matched healthy women. Platelet 5-HT concentrations and MAO-B activity were similar between all patients with AD and healthy subjects, but were significantly lower in patients in the late phase of AD than in other phases of AD, and in healthy controls. The significant correlations were found between MMSE scores and platelet 5-HT concentrations, MAO-B activity and age. Lower platelet 5-HT concentration and MAO-B activity in the late phase of AD suggested that these markers might indicate severity and/or clinical progress of AD.

Double-blind, randomized comparison of olanzapine versus fluphenazine in the long-term treatment of schizophrenia

This study was undertaken to evaluate the efficacy and safety of olanzapine compared with fluphenazine in the treatment of patients who met the Diagnostic and Statistical Manual, fourth edition (DSM-IV) diagnostic criteria for schizophrenia or schizoaffective disorder. This was a long-term (22-week), randomized, double-blind, parallel clinical trial. Sixty patients (mean age, 35.4 years) were randomly assigned to either olanzapine (n=30) or fluphenazine (n=30). They received treatment at three centers in Croatia during a 22-week study period and were assessed weekly for the first 6 weeks and monthly thereafter. Efficacy was measured using the Brief Psychiatric Rating Scale (BPRS), the Positive and Negative Syndrome Rating Scale (PANSS) and the Clinical Global Impression (CGI) Severity and Improvement scores. The Hillside Akathisia Scale (HAS), Simpson-Angus Scale (SAS), Abnormal Involuntary Movement Scale (AIMS), vital signs, laboratory tests, and treatment-emergent adverse events were assessed to evaluate safety. The olanzapine group showed significantly greater mean decreases from baseline to endpoint for BPRS total (-25.8 vs. -16.5, P=.035), PANSS total (-45.7 vs. -29.5, P=.037), PANSS positive (-13.0 vs. -7.9, P=.034), and CGI Severity (-2.2 vs. -1.3, P=.031) scores. The olanzapine group showed greater mean decreases on all measures of extrapyramidal symptoms, significantly so for the SAS (-2.1 vs. 1.9, P=.004) and HAS (-3.4 vs. 2.6, P=.028). Patients in the fluphenazine group experienced a higher incidence of treatment-emergent adverse events (76.7% vs. 50.0%, P=.032). Weight gain was the most frequently reported adverse event in the olanzapine group (16.7% vs. 0.0%, P=.020). Akathisia (30.0% vs. 10.0%, P=.053) and insomnia (20.0% vs. 0.0%, P=.010) appeared most frequent in the fluphenazine group. Daily use of anticholinergics and benzodiazepines were both significantly greater for the fluphenazine group (P=.003 and.04, respectively). No significant changes were observed in vital signs, ECG, or clinical chemistry. The study indicates that olanzapine has advantages in both efficacy and safety compared to fluphenazine; however, the small sample size limits our ability to draw definitive conclusions.

Posttraumatic stress disorder and platelet serotonin measures

The role of serotonin (5HT) in the pathophysiology of posttraumatic stress disorder (PTSD) has been suggested by the overlap in clinical symptoms between PTSD and psychiatric conditions in which a serotonin dysfunction is implicated, as well as by the therapeutic efficiency of 5HT-related drugs (antidepressants, selective serotonin reuptake inhibitors and monoamine oxidase inhibitors) in alleviating symptoms in PTSD. In the present study, the blood platelet, which has been proposed as a peripheral model for the central serotonergic neurons, has been used to search for alterations in 5HT mechanisms in PTSD. Platelet serotonin level and kinetics of serotonin transporter and monoamine oxidase (MAO-B) were assessed in 63 combat-related PTSD patients and 43 sex and age-matched control subjects. A significant reduction in maximal velocity of platelet MAO-B (approx. 30%), with no changes in the enzyme affinity was observed in our patient sample. Conversely, no alterations in kinetic parameters (V(max), K(m)) of platelet serotonin transporter, as well as in platelet 5HT level, were found in the PTSD group.

Genotype-independent decrease in plasma dopamine beta-hydroxylase activity in Alzheimer's disease

The noradrenergic system is involved in the etiology and progression of Alzheimers disease (AD) but its role is still unclear. Dopamine beta-hydroxylase (DBH) as a catecholamine-synthesizing enzyme plays a central role in noradrenaline (NA) synthesis and turnover. Plasma DBH (pDBH) activity shows wide inheritable interindividual variability that is under genetic control. The aim of this study was to determine pDBH activity, DBH (C-970T; rs1611115) and DBH (C1603T; rs6271) gene polymorphisms in 207 patients with AD and in 90 healthy age-matched controls. Plasma DBH activity was lower, particularly in the early stage of AD, compared to values in middle and late stages of the disease, as well as to control values. Two-way ANOVA revealed significant effect of both diagnosis and DBH (C-970T) or DBH (C1603T) genotypes on pDBH activity, but without significant diagnosis×genotype interaction. No association was found between AD and DBH C-970T (OR=1.08, 95% CI 1.13-4.37; p=0.779) and C1603T (OR=0.89; 95% CI 0.36-2.20; p=0.814) genotypes controlled for age, gender, and ApoE4 allele. The decrease in pDBH activity, found in early phase of AD suggests that alterations in DBH activity represent a compensatory mechanism for the loss of noradrenergic neurons, and that treatment with selective NA reuptake inhibitors may be indicated in early stages of AD to compensate for loss of noradrenergic activity in the locus coeruleus.

Baseline level of platelet-leukocyte aggregates, platelet CD63 expression, and soluble P-selectin concentration in patients with posttraumatic stress disorder: A pilot study

Platelets may have an important role in the development of cardiovascular disease (CVD) as a result of chronic stress. We conducted a pilot study to evaluate the effect of posttraumatic stress disorder (PTSD) on baseline platelet activation. Platelet-leukocyte aggregates (PLA) and CD63 expression were measured by flow cytometry, and soluble (s)P-selectin concentration was determined in sera of 20 Croatian male combat veterans with PTSD and 20 healthy civilians. Groups were matched in sex, age, body mass index (BMI) and traditional CVD risk factors. Our data showed no differences in measured parameters. Other platelet activation markers should be determined and a larger sample size used in future studies.

Catatonic schizophrenia in Croatia

Abstract A representative sample of schizophrenic subjects was collected for epidemiological and clinical follow-up in 1972 from the pool of 8069 patients registered in the Croatian Psychotics Case Register (CPCR). This sample comprised 402 patients (207 males and 195 females), who were followed up until 1990/91. The diagnosis of schizophrenia, catatonic type according to ICD-8 (V/295.2), was made in 59 cases (14.7 %; 28 males, 31 females) at least once in the course of the follow-up. This study presents data concerning the diagnostic instability of the catatonic subtype during the long-term follow-up. As subtype diagnoses were frequently changed over the course of illness, at the end of the follow-up, the diagnosis of catatonic schizophrenia was only confirmed in 11 (18.6 %) cases. Positive family history of psychosis was found in 44.1 % of catatonic patients, a percent significantly greater than the corresponding figure for all non-catatonic schizophrenic subtypes combined (20.1 %). This study provides preliminary evidence that the catatonic subtype of schizophrenia is a separate diagnostic entity with a high familial loading.

No association between histamine N-methyltransferase functional polymorphism Thr105Ile and Alzheimer's disease

Several abnormalities, including lower histamine levels in brain, elevated serum histamine and degeneration of histaminergic neurons in tuberomammillary nucleus, were described in the histaminergic system of patients with Alzheimers disease (AD). Histamine is a central neurotransmitter with several functions in brain including regulation of memory, cognition, locomotion, and is degraded in part by histamine N-methyltransferase (HNMT). A common Thr105Ile polymorphism within HNMT gene results in decreased enzyme activity. The Thr105Ile polymorphism was associated with Parkinsons disease, essential tremor, attention-deficit hyperactivity disorder (ADHD), asthma and alcoholism, thus we tested possible association of HNMT functional polymorphism with AD. We have tested 256 AD cases and 1190 healthy controls of Croatian origin. Thr105Ile polymorphism was determined by TaqMan RT-PCR Genotyping Assay and EcoRV digestion. Prevalence of functional HNMT polymorphism among all tested groups was similar and frequency of less active Ile105 variant was 11.5% among AD patients and 13.4% for healthy controls (p=0.26, X(2)=1.25). Our results indicate lack of the association of HNMT Thr105Ile functional polymorphism with Alzheimers disease.