J Horácek

The Police Academy of the Czech Republic in Prague, Praha, Praha, Czech Republic

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Publications (135)133.88 Total impact

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    Clinical EEG and neuroscience: official journal of the EEG and Clinical Neuroscience Society (ENCS) 12/2013; 44(4):E1-121. · 1.82 Impact Factor
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    ABSTRACT: OBJECTIVEs: Ketamine and other NMDA (N-methyl-D-aspartate) antagonists produce fast-acting antidepressant-like effects, although the underlying mechanism is unclear. Furthermore, high affinity NMDA antagonists such as ketamine are associated with psychotomimetic effects. To date the link between the antidepressant and psychotomimetic effects of ketamine has not been explored. We examined the relationship between the antidepressant and psychotomimetic effects of a single ketamine infusion in subjects diagnosed with major depressive disorder. METHODS: In a double-blind, cross-over, placebo-controlled, two weeks clinical trial we studied the effects of ketamine (0.54 mg/kg within 30 min) in a group of 27 hospitalized depressive patients. RESULTS: Higher intensity of psychotomimetic symptoms, measured using BPRS, during ketamine administration correlated with alleviation in mood ratings during the following week with maximum on day seven. Ketamine was superior to placebo in all visits (day 1, 4, and 7) assessed by MADRS with effect size (Cohen s d) of 0.62, 0.57, and 0.44 respectively. There was no significant correlation between ketamine and nor-ketamine plasma levels and MADRS score change at any study time point. CONCLUSION: The substantial relationship between ketamine's antidepressant and psychotomimetic effects was found. This relationship could be mediated by the initial steps of ketamine's action, trough NMDA receptors, shared by both ketamine's clinical effects.
    Neuro Endocrinol Lett. 01/2013; 34(4):287-293.
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    ABSTRACT: Low-frequency repetitive transcranial magnetic stimulation (LF-rTMS) of the left temporo-parietal cortex (LTPC) has been proposed as a useful therapeutic method for auditory hallucinations (AHs). Stereotactic neuronavigation enables the magnetic coil to be targeted according to the individual parameters obtained from neuroimaging. Individualized rTMS neuronavigated according to 18-fluorodeoxyglucose positron emission tomography ((18)FDG PET) allows us to focus the coil explicitly on a given area with detected maxima of specific abnormalities, thus presuming a higher therapeutic effect of the method. The objective of this study is to test clinical efficacy of neuronavigated LF-rTMS administered according to the local maxima of (18)FDG PET uptake of LTPC and to compare it with treatment effects of standard and sham rTMS. In a double-blind, sham-controlled design, patients with AHs underwent a 10-day series of LF-rTMS using (1) (18)FDG PET-guided "neuronavigation," (2) "standard" anatomically guided positioning, and (3) sham coil. The effect of different rTMS conditions was assessed by the Auditory Hallucinations Rating Scale (AHRS) and the Positive and Negative Syndrome Scale (PANSS). Fifteen patients were randomized to a treatment sequence and ten of them completed all three treatment conditions. The intention-to-treat analysis of AHRS score change revealed superiority of the (18)FDG PET-guided rTMS over both the standard and the sham rTMS. The analyses of the PANSS scores failed to detect significant difference among the treatments. Our data showed acute efficacy of (18)FDG PET-guided rTMS in the treatment of AHs. Neuronavigated rTMS was found to be more effective than standard, anatomically guided rTMS.
    European Archives of Psychiatry and Clinical Neuroscience 09/2012; · 2.75 Impact Factor
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    ABSTRACT: Background: Dental procedures on intellectually disabled patients represent a clinical challenge. The oral administration of sedating drugs can remediate the problems with cooperation and enable the medical procedures to take place. Standard guidelines are lacking for oral sedation of the intellectually disabled. To compare two oral combinations of sedating drugs in terms of time to the onset and achievement of full sedation, vital signs, behavioral measures and safety. In a group of 29 intellectually disabled patients we compared two oral combinations for analgosedation: ketamine (5 mg/kg) - clonidine 2 µg/kg - midazolam 0.3 mg/kg (N=17) or ketamine 5 mg/kg - midazolam 0.3 mg/kg (N= 12 patients). Drugs were dissolved in a sweet drink. Full sedation was achieved within 25 min. in 27 patients and serious side effects were not detected. Clonidine in combination with ketamine and midazolam did not exert any significant effect by means of the onset of sedation, time to the achievement of full sedation, vital signs and behavioral measures of sedation (Vancouver Interaction and Calmness Scale) and agitation (Pittsburgh Agitation Scale). Our study is the first to document that oral administration of ketamine and midazolam in low doses represents a safe and effective method of premedication in intellectually disabled patients indicated for dental procedures. Clonidine co-administration did not exert any substantial benefit and should be left out in this clinical setting.
    Neuro endocrinology letters 08/2012; 33(4):380-4. · 0.93 Impact Factor
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    ABSTRACT: This review focuses on the relationship between psychotropic drugs and adult hippocampal neurogenesis. Adult neurogenesis is important for learning and memory, as well as for depression and anxiety. There is some evidence that chronic treatment with opiates, stimulants and entactogens decreases neurogenesis and consequently impairs cognitive function, as well as inducing depressive-like behaviour in animals during drug withdrawal. On the other hand, NMDA receptor antagonists increase neurogenesis, but negatively affect cognitive function and have an antidepressant-like profile. We suggest that drug-induced changes in neurogenesis have a greater and more concise effect on emotive state reflecting the direction of influencing new cells proliferation than the performance of cognitive tasks. In this review we provide some evidence for this assumption.
    Neuroscience Research 03/2012; 73(2):93-8. · 2.20 Impact Factor
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    ABSTRACT: Abstract Objectives. To address the role of latent T. gondii infection in schizophrenia we studied the influence of latent toxoplasmosis on brain morphology. Methods. An optimized voxel-based morphometry of magnetic resonance imaging was analyzed by analysis of variance with diagnosis and seropositivity as factors in 44 schizophrenic patients (12 T. gondii positive) and 56 controls (13 T. gondii positive). Results. Grey matter (GM) volume was reduced in schizophrenia patients compared with controls in the cortical regions, hippocampus and in the caudate. In the schizophrenia sample we found a significant reduction of GM volume in T. gondii positive comparing with T. gondii-negative patients bilaterally in the caudate, median cingulate, thalamus and occipital cortex and in the left cerebellar hemispheres. T. gondii-positive and -negative controls did not differ in any cluster. Among participants seropositive to T. gondii the reduction of GM in the schizophrenia subjects was located in the same regions when comparing the entire sample (11,660 over-threshold voxels (P ≤ 0.05, FWR corrected). The differences between T. gondii-negative patients and controls consisted only of 289 voxels in temporal regions. Conclusions. Our study is the first to document that latent toxoplasmosis reduces GM in schizophrenia but not in controls.
    The World Journal of Biological Psychiatry 05/2011; 13(7):501-9. · 3.57 Impact Factor
  • European Neuropsychopharmacology - EUR NEUROPSYCHOPHARMACOL. 01/2011; 21.
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    ABSTRACT: The regulator of G-protein signaling (RGS) molecules represent a class of proteins that modulate the signaling activity of G-protein coupled receptors. Regulator of G-protein signaling 4 (RGS4) is of particular interest in schizophrenia due to reported downregulation of RGS4 transcripts in schizophrenia as well as a connection between RGS4 and a number of receptors implicated in schizophrenia. The mechanism of RGS4 involvement in the pathophysiology of this illness is not clear. To elucidate thise role of RGS4 in pathophysiology of schizophrenia, we silenced RGS4 using siRNAs in human neuroblastoma cell lines and we studied the effects of differential RGS4 expression by microarray. The cell lines with downregulated expression of RGS4 showed 67 genes with changed expression (30 underexpressed and 37 overexpressed). We have detected three subgroups of genes which might be implicated in schizophrenia pathophysiology: histone genes, which suggest epigenetic mechanisms of the disease; genes for transcription factors associated with other genes relevant to schizophrenia pathology (BDNF and DISCI1) and a heterogeneous group containing genes for G-proteins (GPR50 and GPR64) and calcium binding proteins.
    Neuro endocrinology letters 01/2011; 32(3):246-52. · 0.93 Impact Factor
  • European Psychiatry - EUR PSYCHIAT. 01/2011; 26:695-696.
  • European Neuropsychopharmacology - EUR NEUROPSYCHOPHARMACOL. 01/2011; 21.
  • European Psychiatry - EUR PSYCHIAT. 01/2011; 26:2124-2124.
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    ABSTRACT: Augmentation therapy with serotonin-1A receptor (5-HT1A) partial agonists has been suggested to ameliorate psychotic symptoms in patients with schizophrenia. The objective of the present study was to examine the effect of repeated administration of tandospirone (0.05 and 5 mg/kg) on locomotor activity in a novel environment and on sensorimotor gating in rats treated with the N-methyl-D-aspartate receptor antagonist MK-801, which has been used in animal models of schizophrenia. Furthermore, we sought to determine whether the effect of tandospirone on these behavioural measures is blocked by WAY 100635 (0.3 mg/kg), a 5-HT1A receptor antagonist, and whether there is an interaction between haloperidol (0.1 mg/kg; a dopamine-D2 receptor antagonist) and tandospirone. Tandospirone at 5 mg/kg, but not 0.05 mg/kg, decreased locomotor activity in saline or MK-801-treated rats, which were not affected by co-treatment with WAY 100635. Haloperidol decreased locomotion both in saline and MK-801-treated animals, and this effect was not evident in the latter group receiving the higher dose of tandospirone. Tandospirone (5 mg/kg)-induced disruption of sensorimotor gating in saline or MK-801-treated animals was reversed by WAY-100635, but not by haloperidol. These findings suggest that behavioural changes induced by tandospirone are not fully blocked by 5-HT1A antagonists and that tandospirone (5 mg/kg) potentiates the effect of MK-801. Overall, these findings point to an interaction between NMDA and 5-HT(1A) receptors. Part of the effect of tandospirone on locomotor activity may be mediated by the actions of its active metabolites on other neurotransmitter systems.
    Psychopharmacology 10/2010; 212(2):267-76. · 4.06 Impact Factor
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    ABSTRACT: An analysis of incidence of congenital heart defects (CHD) in the Czech Republic in the 1994 - 2008 period. An assessment of absolute numbers, frequencies and incidences for particular selected diagnoses according to 10th decennial revision of International Classification of Diseases (ICD-10). An analysis of pre- and postnatal incidences of selected diagnoses and of a secondary prevention measures efficiency in the Czech Republic. A retrospective epidemiological analysis of congenital anomalies from the database of the National Register of Birth Defects (NRBD) of the Czech Republic. Data from the NRBD from the 1994 - 2008 period were used. In our study, CHD incidences (ICD-10 Q20-Q28 Congenital malformations of the circulatory system group) in the Czech Republic were analyzed. First, CHD incidences in births were assessed - absolute numbers, frequencies and incidences for particular selected diagnoses. Second, absolute numbers, frequencies and incidences of particular selected diagnoses in prenatally diagnosed fetuses and a secondary prevention measures efficiency in selected CHD were evaluated. In a third part, survival of babies with CHD during the first year of their life was analyzed. In the period under the study, there were a total of 1 472 610 life births in the Czech Republic. Congenital malformations of the circulatory system (Q20-Q28) present more than 40% of all registered congenital anomalies and are themselves the most frequent birth defect group in births in the Czech Republic. As a whole, 29 133 CHD were diagnosed (197.83 per 10 000 live births) in 18 811 children (127.53 per 10 000 live births) in this period, which presents more than 36% of children born with a congenital anomaly in the Czech Republic during 1994 - 2008. CHD most frequently diagnosed in births were congenital malformations of cardiac septa (total 16 428, 145.05 per 10 000 live births, more than 55% of all CHD) and congenital malformations of great arteries (total 5389, 47.58 per 10 000 live births, more than 18% of all CHD). Further, prenatally diagnosed CHD were analyzed. Incidences for particular diagnoses as well as percentage of pregnancy termination were assessed. A rate of prenatally diagnosed was 11.35% in discordant ventriculoarterial connection (Q20.3), 8.35% in discordant atrioventricular connection (Q20.5), 49.41% in hypoplastic left heart syndrome (Q23.4), 7.64% in coarctation of aorta (Q25.1) and 9.71% in tetralogy of Fallot (Q21.3). These anomalies were parts of chromosomal syndromes in 42.58% and non-chromosomal syndromes in 9.33%. There were also associated malformations (from other systems than circulatory one). The most frequent were congenital malformations of the nervous system (Q00-Q07) - 14.59%, congenital malformations and deformations of the musculoskeletal system (Q65-Q79) - 12.44%, cleft lip and cleft palate (Q35-Q37) - 7.42% and congenital malformations of the urinary system (Q60-Q64) - 6.70%. In children born with a CHD, 84.53% were associated with other anomaly, out of which more than 70% were CHD only. Only about 14% were associated with anomalies from other (non-circulatory system) groups. Perinatal mortality was highest in hypoplastic left heart syndrome (Q23.4) - 327.103 per thousand and in tetralogy of Fallot (Q21.3) - 6.565 per thousand. The study presents current results of analysis of CHD incidences in the Czech Republic in the 1994 - 2008 period. Children born with a CHD make more than 36% out of all children born with a congenital anomaly. CHD themselves represents an important part (more than 40%) of all diagnosed congenital anomalies in the Czech Republic. Over the period of the study there was a slight increase of diagnosed CHD during 1994 - 1999 followed by a slight decrease from 2000 with an exception of 2007 year. The most frequent of diagnosed CHD were ventricular septal defect (Q21.0) and atrial septal defect (Q21.1). Both defects incidences changes influence not only a total CHD but also a total congenital anomalies incidence. An influence of prenatal diagnostics among the five selected CHD was most important in hypoplastic left heart syndrome (Q23.4), less so in others. In prenatal diagnostics group, it is necessary to distinguish between those anomalies, which led to pregnancy termination (parts of both chromosomal and non-chromosomal syndromes and/or association with other severe anomalies) and those in which pregnancy leads to a delivery (late diagnostics, operabile defects, parental decision). CHD can be a part of chromosomal syndromes. In our study, in prenatally diagnosed CHD it was more than 42%. A presence of other associated diagnoses of congenital anomalies in births will significantly influence infant mortality and morbidity.
    Ceska gynekologie / Ceska lekarska spolecnost J. Ev. Purkyne 05/2010; 75(3):221-42.
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    ABSTRACT: There is accumulating evidence that disturbances in N-methyl-D: -aspartate receptor (NMDA-R) functioning are associated with the pathogenesis of schizophrenia. To assess actual changes in the expression of the GluN1 subunit and its isoforms, we measured absolute differences in the levels of mRNA/protein for panGluN1 (eight isoforms altogether) as well as the mRNA individual isoforms in the postmortem left/right hippocampus of patients with schizophrenia in comparison with non-psychiatric subjects. There were no significant differences in the panGluN1 subunit mRNA expression, but the absolute left/right differences were much more pronounced in the patients with schizophrenia. Protein levels of the GluN1 subunit in the left hippocampus in male schizophrenic patients were lower than controls. The expression of the NR1-4b isoform was attenuated in the left, whereas the NR1-2b was reduced in the right hippocampus of schizophrenic patients. Isoforms associated with the efficiency of NMDA-induced gene expression and with phosphorylation occurred more commonly in schizophrenic hippocampi. In summary, our study suggests that NMDA-R hypofunction in schizophrenia might be selectively dependent on the dysregulation of GluN1 subunit expression, which exhibits a somewhat different expression in the left/right hippocampus of psychotic patients.
    Neurochemical Research 03/2010; 35(7):994-1002. · 2.13 Impact Factor
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    ABSTRACT: The aim of this study was to describe sex differences in the behavioural effects of N,N-diethyllysergamide (LSD) (locomotor activity and other behavioural repertoire in the open field) and its effects on sensorimotor gating in rats (prepulse inhibition (PPI) of the acoustic startle reaction). Three groups of animals were analysed: males, oestral and pro-oestral phase females (EP females), and metoestral and dioestral phase females (MD females). LSD (5, 50 and 200 microg/kg subcutaneously) attenuated locomotor activity and normal behavioural repertoire, and induced flat body posture, wet dog shakes and disrupted PPI. The most prominent behavioural findings of LSD were for LSD 200 microg/kg which suppressed almost all behavioural activity. LSD had mainly inhibitory locomotor effects in males and MD females, yet in EP female rats LSD increased locomotion during the second half of testing period. The main sex differences were observed in locomotor and exploratory behaviour. Both EP and MD females were less sensitive to hypolocomotor effects of LSD and had less pronounced thigmotaxis than males. Further EP females had increased rearing after LSD 5microg/kg. On the contrary although LSD disrupted PPI in males and MD female rats, EP females were protected from this disruptive effect. Thus, EP females seem to have a lower sensitivity to LSD behavioural actions.
    Progress in Neuro-Psychopharmacology and Biological Psychiatry 02/2010; 34(4):588-96. · 3.55 Impact Factor
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    ABSTRACT: An analysis of occurrence of birth defects in the Czech Republic regions in 1994 - 2007. An assessment of total numbers and relative incidences of birth defects in births according to Tenth Revision of International Classification of Diseases (ICD-10). TYP OF STUDY: Retrospective epidemiological analysis of birth defects incidences in the Czech Republic and its particular regions from the Czech National Birth Defects Register database. Data from the National Birth Defects Register (Institute for Health Information and Statistics) in the Czech Republic in the 1994 - 2007 period were used. In this study, particular diagnoses--as they were registered in the National Register--were analyzed. The diagoses in study were divided into following eleven birth defects groups according to ICD-10 classification: (Q00-Q07) nervous system, (Q10-Q18) eye, ear, face and neck, (Q20-Q28) circulatory system, (Q30-Q34) respiratory system, (Q35-Q37) cleft lip and cleft palate, (Q38-Q45) digestive system, (Q50-Q56) genital organs, (Q60-Q64) urinary system, (Q65-Q79) musculoskeletal system, (Q80-Q89) other defects and (Q90-Q99) chromosomal abnormalities, not elsewhere classified. Prenataly diagnosed cases were not included. Birth defects in births were analyzed both in terms of the whole Czech Republic and its 14 particular administrative regions: Prague (the Capital City), Stredoceský, Jihoceský, Plzenský, Karlovarský, Ustecký, Liberecký, Královéhradecký, Pardubický, Vysocina, Jihomoravský, Olomoucký, Zlínský and Moravskoslezský. During 1994 - 2007 period, totally 1,353,040 children were born on the area of the Czech Republic, out of which 44,343 with a birth defect (totally 65,186 birth defects diagnoses). The diagoses in study were divided into eleven groups according to ICD-10 classification. Further, particular diagnoses according to ICD-10 and their verbal descriptions are presented in tables. Each group is accompanied by data on its total number and a relative incidence (per 10,000 live births) with a 95% C.I. A relative frequency of the birth defects groups in study (in % from the total number of birth defects) is as follows: (Q00-Q07) nervous system 2.10, (Q10-Q18) eye, ear, face and neck 4.76, (Q20-Q28) circulatory system 39.63, (Q30-Q34) respiratory system 1.03, (Q35-Q37) cleft lip and cleft palate 3.67, (Q38-Q45) digestive system 4.05, (Q50-Q56) genital organs 10.93, (Q60-Q64) urinary system 7.08, (Q65-Q79) musculoskeletal system 18.90, (Q80-Q89) other defects 5.55 and (Q90-Q99) chromosomal abnormalities 2.28. Relative number of birth defects per region (in % from the total number of birth defects) and deviations from a mean incidence of birth defects in the Czech Republic (total Czech Republic expressed as 100%, in brackets) were calculated for each particular region: Prague (the Capital City) 10.75 (97.82), Stredoceský 11.27 (102.25), Jihoceský 6.13 (99.53), Plzenský 5.27 (105.03), Karlovarský 3.09 (134.15), Ustecký 8.67 (118.03), Liberecký 4.38 (82.93), Královéhradecký 5.41 (112.14), Pardubický 5.04 (110.32), Vysocina 5.11 (99.43), Jihomoravský 10.76 (79.11), Olomoucký 6.16 (79.47), Zlínský 5.58 (90.60) and Moravskoslezský 12.39 (105.91). The study gives updated results of incidences analysis of birth defects in births in the Czech Republic and its 14 administrative regions during the 1994 - 2007 period. Variance in birh defects occurrence was found, reflecting more a distribution of incidences according to smaller administrative units (districts) than to a regional distribution. Less important differences in birth defects groups incidences between particular regions were also found.
    Ceska gynekologie / Ceska lekarska spolecnost J. Ev. Purkyne 02/2010; 75(1):15-40.
  • European Neuropsychopharmacology - EUR NEUROPSYCHOPHARMACOL. 01/2010; 20.
  • European Neuropsychopharmacology - EUR NEUROPSYCHOPHARMACOL. 01/2010; 20.
  • European Neuropsychopharmacology - EUR NEUROPSYCHOPHARMACOL. 01/2010; 20.
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    ABSTRACT: Theta cordance is a novel quantitative electroencephalography (QEEG) measure that correlates with cerebral perfusion. A series of clinical studies has demonstrated that the prefrontal theta cordance value decreases after 1 week of treatment in responders to antidepressants and that this effect precedes clinical improvement. Ketamine, a non-competitive antagonist of N-methyl-D-aspartate (NMDA) receptors, has a unique rapid antidepressant effect but its influence on theta cordance is unknown. In a double-blind, cross-over, placebo-controlled experiment we studied the acute effect of ketamine (0.54 mg/kg within 30 min) on theta cordance in a group of 20 healthy volunteers. Ketamine infusion induced a decrease in prefrontal theta cordance and an increase in the central region theta cordance after 10 and 30 min. The change in prefrontal theta cordance correlated with ketamine and norketamine blood levels after 10 min of ketamine infusion. Our data indicate that ketamine infusion immediately induces changes similar to those that monoamineric-based antidepressants induce gradually. The reduction in theta cordance could be a marker and a predictor of the fast-acting antidepressant effect of ketamine, a hypothesis that could be tested in depressive patients treated with ketamine.
    Psychological Medicine 12/2009; 40(9):1443-51. · 5.59 Impact Factor

Publication Stats

625 Citations
133.88 Total Impact Points

Institutions

  • 2012
    • The Police Academy of the Czech Republic in Prague
      Praha, Praha, Czech Republic
  • 2004–2012
    • Prague Psychiatric Center
      Praha, Praha, Czech Republic
  • 1999–2009
    • Charles University in Prague
      • Psychiatrické centrum Praha
      Praha, Hlavni mesto Praha, Czech Republic
  • 2006–2008
    • Thomayerova nemocnice
      Praha, Praha, Czech Republic
  • 1998–2007
    • Ústav pro péči o matku a dítě
      Praha, Praha, Czech Republic