Toxoplasmosis is one of the world's most prevalent zoonoses. The causative agent, Toxoplasma gondii (Nicolle et Manceaux, 1908) is a facultative heteroxenic, polyxenic apicomplexan protist. There are several potential pathways of transmission within and between host species. Most infections with T. gondii result from close contact with pets/cats, ingestion of tissue cysts in undercooked meat of infected animals, and oocysts from food or water contaminated by feline faeces. Recently, epidemiological studies have shown that T. gondii infection plays a prominent role in the pathogenesis of several psychiatric disorders. This report reviews the association between T. gondii infection and patients with psychiatric disorders, particularly schizophrenia, depressive disorders and bipolar disorders.
Perinatal cerebral hypoxia represents a major cause of obstetric complications and the resulting transient oxygen deficiency might belong to early risk factors for schizophrenia. The aim of this study was to evaluate possible long-term behavioral changes induced by one hour of continuous bilateral common carotid artery occlusion in 12-day-old male rats. Post-ischemic behavioral disturbances were evaluated in social (play) behavior on postnatal day 22 (PND 22), open field test (PND 35 and 50) and prepulse inhibition of the acoustic startle reflex (PND 50). Transient ischemia in neonatal rats was not significantly altered in social dyadic interactions evaluated in pre-weaning pups, but resulted in enhanced locomotor activity in pubertal rats (PND 35) and impaired prepulse inhibition of the startle reflex in post- pubertal males (PND 50). These behavioral alterations suggest that perinatal hypoxic/ischemic insults may represent a risk factor for later manifestation of specific features relevant to schizophrenia in predisposed individuals., F. Tejkalová, M. Kaiser, J. Klaschka, F. Šťastný., and Obsahuje bibliografii a bibliografické odkazy
Numerous recent studies show that vitamin D deficiency potentiates various chronic physical and psychiatric disorders and diseases. It has been shown that a similar range of disorders is also associated with latent infection with Toxoplasma gondii (Nicolle et Manceaux, 1908). For instance, among cancer, diabetes and schizophrenia patients, we find a higher prevalence of both toxoplasmosis and vitamin D deficiency. Theoretically, therefore, vitamin D deficiency could be the missing link between toxoplasmosis and these disorders. We tested this hypothesis by searching for decreased vitamin D levels in the serum of subjects infected with T. gondii (furthermore called Toxoplasma-infected subjects) in two cross-sectional and one case-control study. Results of the first cross-sectional study (N = 72) suggest that Toxoplasma-infected neurasthenic patients have non-significantly lower levels of calcidiol than Toxoplasma-free patients (study A: P = 0.26 in women, P = 0.68 in men). However, two other studies (study B: N = 400; study C: N = 191) showed a non-significantly higher concentration of vitamin D in Toxoplasma-infected subjects than in Toxoplasma-free subjects both in men (study B: P = 0.70, study C: P = 0.55) and in women (study B: P = 0.64, study C: P = 0.12). Taken together, our preliminary results thus do not support the hypothesis that toxoplasmosis could be associated with vitamin D decrease.
Cell-mediated immunity (CMI) response of healthy humans and cancer (Ca) patients to specific tumor antigen and nonspecific (LDV -- lactate dehydrogenase virus) antigen, and of acute myocardial infarction (AMI) and schizophrenia (Sch) patients to nonspecific antigen was investigated. Large differences of CMI response of healthy humans in comparison with Ca, AMI, Sch patients were found. CMI response to antigens displays transferred information about cells under immune surveillance. LDV disturbs the oxidative energy production system. We assume that CMI response to LDV antigen monitors pathological states of mitochondrial energy production which results in disturbances of electromagnetic activity of living cells.
Alterations in phospholipid metabolism in blood elements have been proposed as the possible biochemical marker of schizophrenia. In the present study, we investigated the composition and membrane distribution of phospholipids in platelets of drug-free schizophrenic patients and controls. We have demonstrated that platelets of drug-free schizophrenics have significantly higher cytosolic Ca2+ levels in comparison with healthy controls. Platelets of drug-free schizophrenic patients have a lower content of phosphatidylinositol (PI). After thrombin activation, PI is the target of phospholipase C instead of phosphatidylinositol 4,5-bisphosphate (PIP2), which is hydrolyzed in platelets of controls. Alterations in the distribution of phospholipids were found in the plasma membrane of platelets of schizophrenic patients. We suggest that alterations in phospholipid metabolism might be evoked by a disturbance of calcium homeostasis in schizophrenic patients.
Sociální kognicí, tedy způsobem, jakým si lidé představují, vnímají a vyvozují závěry o duševních a emocionálních stavech druhých lidí, se zabývá několik teorií. Mezi nejvlivnější patří Teorie mysli (ToM), méně známý je koncept interpersonální decentrace (ID), kterou Feffer definuje jako schopnost brát v úvahu vlastní pocity a myšlenky zároveň s pocity a myšlenkami druhého. Autoři provedli výzkum ID u 50 hospitalizovaných pacientů s poruchou psychotického spektra (z toho 45 se schizofrenií) s cílem popsat jejich výkony v oblasti ID, ověřit vztah mezi mírou ID a vybranými proměnnými, a srovnat zjištění se studiemi realizovanými na jiných populacích. K posuzování míry ID využili Tematický apercepční test (TAT), konkrétně následujících deset karet: 1, 2, 3BM, 4, 5, 6GF, 8BM, 10, 12M, 13MF. Získaných 500 příběhů vyhodnotili dle manuálu z hlediska ID. Výzkumný soubor tvořilo 36 mužů a 14 žen ve věku 19-70 let s průměrnou délkou vzdělání 12 let. Celkově byla míra ID u hospitalizovaných pacientů stabilně velmi nízká a statisticky signifikantně nižší, než ukazují dostupná data jiných klinických skupin. Toto zjištění je v souladu s poznatky ToM. Výsledky v oblasti ID v rámci zkoumaného souboru nesouvisí s pohlavím, vzděláním, přítomností partnerského vztahu a závažností, což podporuje hypotézu, že jde o stabilní osobnostní rys osob se schizofrenií, a může se jednat o prodrom psychotického onemocnění. Tento závěr by byl v souladu s neurovývojovou hypotézou schizofrenie, avšak vyžaduje další ověření, nejlépe longitudinální výzkum dětí od předškolního věku do dospělosti., Objectives. The purpose of this study was to describe interpersonal decentering (ID), a less know concept of social cognition, in patients with schizophrenia. Sample and setting. The research sample included 50 hospitalized patients (36 males, 14 females) with phychotic spectrum disorder (45 with schizophrenia) aged 19-70. For assessment of ID ten cards of the Thematic Apperception Test (TAT): 1, 2, 3BM, 4, 5, 6GF, 8BM, 10, 12M, 13MF were used. 500 TAT stories were collected and scored according to the manual of ID. Hypotheses. The aim was to describe the performances of ID, verigy the correlation between ID and selected variables, and compare the findings with studies realized in other populations. Statistical analysis. To verify the hypotheses, Pearson's correlation coefficient and Student's t-test were calculated. Results. The levels of ID in the sample were consistently very low and statistically significantly lower than the available data of other clinical groups. This finding is consistent with the findings of other concepts of social cognition, e.g. Theory of Mind. Results of ID in the sample were not significantly related to gender, education, presence of partner relationship and severity of disorder. This findings support the hypothesis that ID is a stable personality trait of people with schizophrenia, and may be prodrom of psychotic illness. Study limitation. The main limitation of the study is that all participants were inpatients and their ID results might differ from the outpatient population. The conclusion corresponds with the neurodevelopmental hypothesis of schizophrenia but requires further verification, prefarably longitudinal research of children from preschool age to adulthood., Martin Lečbych, Kristýna Hosáková., and Obsahuje bibliografii a bibliografické odkazy
Předkládaná výzkumná studie se zabývá zmapováním diskurzů o schizofrenii v českém prostředí. V rámci výzkumu byly prováděny polostrukturované rozhovory o schizofrenii s laiky, s lidmi s diagnózou a s odborníky (N = 15). Přepsané rozhovory byly následně analyzovány jedním z přístupů diskurzivní analýzy – kritickou diskurzivní psychologií. Celkem bylo identifikováno 13 odlišných interpretačních repertoárů, které respondenti využívali pro konstruování schizofrenie a člověka s diagnózou. Také byly zmapovány pozice, které tyto repertoáry umožňují zaujmout, důsledky, jaké identifikované repertoáry přináší, a repertoáry byly zasazeny do globálních diskurzů. Respondenti zaujímali větší množství mnohdy protichůdných repertoárů. V diskusi byly následně konfrontovány výsledky s relevantními studiemi. Dále byly popsány limity předkládané studie a návrhy možných navazujících výzkumů a aplikace do praxe. and The presented research study deals with the mapping of discourses on schizophrenia in the Czech environment. The research conducted semi-structured interviews on schizophrenia with lay people, people with diagnosis and experts (N = 15). Those transcribed interviews were subsequently analyzed by one of the discoursive analysis approach – critical discursive psychology. Overall, 13 different interpretative repertoires used by respondents for the construction of schizophrenia and schizophrenic people were identified. Positions that could be hold thanks to these repertoires and consequences of these repertoires were also described. Respondents used a larger number of often conflicting repertoires. Results were confronted with relevant studies in discussion. Further, limits of this study were described as well as suggestions of possible follow-up research and practical application.
Studie analyzuje, srovnává a hodnotí několik hypotéz vysvětlující vznik symptomů schizofrenie, které vznikly v rámci teorie osobních konstruktů. Jejím cílem je zprostředkovat komplexní přehled vývoje na tomto poli od padesátých let minulého století až po současný výzkum. Přehled propojuje teoretická zpracování, empirický výzkum a implikace pro psychoterapii. Začíná základními teoretickými poznatky George Kellyho a hodnotí jejich rozpracování a empirické testování v díle Dona Bannistera, jeho spolupracovníků a následovníků. Zaměřuje se především na vztah mezi konstruktivistickými diagnostickými dimenzemi (volnost – vázanost, fragmentace – integrace, diferenciace – monolitičnost) a symptomy schizofrenie. Závěrečné oddíly se zaměřují na současný výzkum, který je ovlivněn příbuznými přístupy sociálního konstrukcionizmu, narativní psychologie a teorie dialogického já. and Schizophrenia from the point of view of psychology of personal constructs: theory, research, psychotherapy
The study analyses, compares and evaluates several hypotheses explaining symptoms of schizophrenia within the personal construct theory. It aims to provide a complex overview of development in this field from fifties of the last century until current research. The overview connects theoretical considerations, empirical research and implications for psychotherapy. It begins with basic notions of George A. Kelly and reviews their elaboration and empirical testing made by Don Bannister and his collaborators and followers. It focuses especially on relationships between constructivist diagnostic dimensions (loosening - tightening, fragmentation - integration, differentiation – monolithic structure) and symptoms of schizophrenia. Last sections focus on recent research that is influenced by related approaches of social constructionism, narrative psychology and of the theory of dialogical self.
Individuals serologically positive for the chronic infection with the parasite Toxoplasma gondii (TG) display certain personality traits differently from uninfected individuals. Experimental data in mice demonstrate that TG infection modulates behaviour. However, psychiatric patients with a personality disorder have not yet been investigated systematically. In our sample containing 896 psychiatric inpatients with the primary diagnoses of schizophrenia, major depression, schizoaffective or bipolar disorder and 214 psychiatrically unaffected controls (same geographic region, sampled during same time period) we analysed for effects of the additional diagnosis of a personality disorder in the patients. Psychiatrically, a patient can meet the criteria of a personality disorder additionally to any of the mentioned primary diagnoses. We applied logistic regression and cross-table statistics, separated groups by the presence/absence of a personality disorder (ICD-10) and adjusted for age between groups. We found that among all patients the additional diagnosis of a personality disorder was significantly associated with TG infection. Furthermore, only in the patients with an additional personality disorder medium titre responses (1:16-1:64) were associated with chronic course and high C-reactive protein (CRP) levels whereas high titre response (>1:64) was associated with a more acute recurrent clinical course. In the older individuals only there was a preponderance of medium titre responses (1:16-1:64) among the patients with personality disorder compared to those without and controls. We conclude that TG infection and the host's response to it make a difference for the diagnosis of a personality disorder. Our data support that TG infection can modulate human behaviour and personality traits.
We tested risperidone and ritanserin, serotonin-S2 receptor antagonists, for their effects on in vitro polyclonal IgG and IgM synthesis by human peripheral blood mononuclear cells (PBMC) stimulated with pokeweed mitogen (PWM). On the basis of the previously reported effect on immune function in vivo risperidone in this study was tested in three different groups of PBMC: healthy donors as well as schizophrenic patients before risperidone treatment and schizophrenic patients after the treatment with risperidone. IgG and IgM production after 7 days of culture was measured by ELISA. Risperidone decreased IgG synthesis (p<0.05) in PBMC of healthy subjects only at the highest concentration (10~6 M) and IgG synthesis enhanced by 5-HT was antagonized by risperidone. This effect, however, was not statistically significant. Neither risperidone nor ritanserin, in the concentration range 10-8- 10~6M, affected IgM synthesis in this group. Risperidone did not affect the production of IgG and IgM by PBMC of schizophrenic subjects in PWM-stimulated cultures both before and after risperidone therapy. The spontaneous production of IgG in PBMC of schizophrenic subjects before therapy was decreased (p<0.05) at concentrations 10-6-10~7 M of risperidone. We conclude that risperidone and ritanserin did not increase polyclonal IgG and IgM synthesis in vitro in contrast to neuroleptics currently used in clinical practice.