Neuroendocrine response to a psychosocial stress test is not related to schizotypy but cortisol elevation predicts inflexibility of semantic memory retrieval

An altered stress response can contribute to the transition from preclinical psychotic symptoms to the clinical manifestation of schizophrenia and other psychotic disorders. The present study was aimed at testing the hypotheses that (i) the autonomic and neuroendocrine responses under psychosocial stress are dysregulated in individuals with high psychosis proneness (schizotypy); (ii) the magnitude of post-stress autonomic activation and cortisol release predicts alterations in semantic memory retrieval. The study was performed in 73 healthy individuals of both sexes with either high or low schizotypal traits preselected out of 609 individuals using the Schizotypal Personality Questionnaire. A psychosocial stress procedure based on public speech was used as a stress model. We found that individuals with high schizotypy engaged in less adaptive emotional stress-coping strategies than low schizotypy individuals. Yet, the neuroendocrine, immune, and sympathetic activation in response to the stress test was not different between the groups. Irrespective of the exposure to the stressor, individuals with high schizotypy were less fluent when retrieving associations from semantic memory. In addition, we demonstrated that acute psychosocial stress reduced the flexibility of semantic memory retrieval. The post-stress mental inflexibility was reliably predicted by the concomitant elevation of cortisol concentrations in saliva. The present study thus brings novel evidence indicating that the acute psychosocial challenge impairs retrieval flexibility in the semantic domain, which may be due to neuroendocrine activation.

Salivary testosterone, testosterone/cortisol ratio and non-verbal behavior in stress

The relationship between hormone release and non-verbal communication under stress conditions is still not sufficiently explored. The aim of the present study was to test the hypothesis that salivary testosterone concentrations and testosterone/cortisol (T/C) ratios correlate positively with assertive behavior representing a non-aggressive form of dominance during an acute stress situation. As a stress model, a socially evaluated cold pressor test was investigated in healthy men. The non-verbal behavior was analyzed according to the ethological coding system for interviews described by Troisi (1999). Salivary testosterone concentrations did not change throughout the stress test. The T/C ratios decreased significantly over time only in subjects showing high stress perception. The duration of affiliative and the frequency of flight behavior was higher in subjects with high stress perception compared to those with low stress perception. A significant positive correlation between the duration of prosocial behavior and values of T/C ratios was found in the whole sample. The area under the curve values of testosterone positively correlated with the duration of assertive behavior in the group with high stress perception and negatively in the other group. Our findings allow suggesting that the changes in non-verbal behavior during acute psychosocial stress situations may be more pronounced in subjects showing high stress perception. Obtained results motivate further research on a better understanding of the consequences of the lack of sense of full facial expressions, such as wearing face masks, on the balance between hormones and non-verbal behavior under stress conditions.

Visual evoked responses to a gamma-frequency flicker are enhanced in acute schizophrenia

Disturbances of visual perception, such as illusions and hallucinations, are a hallmark of psychotic disorders. In perceptual processes, synchronous neuronal activity in gamma frequencies (> 30 Hz) is considered to play a major role. Steady-state visual evoked potentials (ssVEP) allow for testing the ability of the visual cortex to support synchronous neural responses to periodically flickering light. We employed photic stimulation at 40 Hz in order to specifically drive cortical gamma synchrony. In acute schizophrenia patients, compared to healthy control subjects, we found significantly increased evoked synchrony at 40 Hz, but decreased synchrony in the alpha band (8–13 Hz). Linear decomposition of ssVEP waveforms separated the activity of independent neural sources and revealed their different dynamics in the patients and the controls. The results indicate an aberrant processing of transient visual events in acute schizophrenia.

Cardiovascular diseases and molecular variants of the renin-angiotensin system components in Slovak population

Cardiovascular diseases associated with molecular variants of individual components of renin-angiotensin system are reported to constitute inherited predisposition in humans. Molecular variant frequencies are race- and population-dependent. We examined frequencies of the M235T variant of angiotensinogen gene and I/D polymorphism of gene for angiotensin-converting enzyme in Slovak population: in hypertensive patients, coronary heart disease (CHD), dilated cardiomyopathy (DCM) and myocardial infarction (MI) patients compared to healthy subjects. Frequency of M235T was significantly increased in hypertensive, CHD and DCM patients compared to controls (0.48 and 0.50 vs. 0.40, p < 0.001). Significant increase in D allele frequency compared to controls was observed in the group of patients after MI (0.58 vs. 0.50, p < 0.001), CHD (0.59 vs. 0.50, p < 0.001) and DCM (0.60 vs. 0.50, p < 0.001). These results correlate with other Caucasian populations. In Slovak population, M235T is associated with increased blood pressure and D allele of ACE gene is associated with MI, chronic CHD and DCM, rather than with hypertension. Our results suggest that in Slovak population, D alelle and M235T variant represent a risk factor for several cardiovascular diseases and these polymorphisms might have a cumulative effect on development of cardiovascular diseases.

Chaotic EEG patterns during recall of stressful memory related to panic attack

Chaotic transitions likely emerge in a wide variety of cognitive phenomena and may be linked to specific changes during the development of mental disorders. They represent relatively short periods in the behavior of a system, which are extremely sensitive to very small changes. This increased sensitivity has been suggested to occur also during retrieval of stressful emotional experiences because of their fragmentary, temporally and spatially disorganized character. To test this hypothesis we recorded EEG during retrieval of fearful memories related to panic attack in 7 patients and retrieval of anxiety-related memories in 11 healthy controls. Nonlinear data analysis of EEG records showed a statistically significant increase in degree of chaotic dynamics after retrieval of stressful memories in majority of patients as well as in control subjects. This change correlated with subjective intensity of anxiety induced during the memory retrieval. The data suggest a role of nonlinear changes of neural dynamics in the processing of stressful anxiety-related memories, which may play an important role in the pathophysiology of panic disorder.

Initial experiences with novel therapy for pulmonary hypertension in Slovakia

Pulmonary hypertension (PH) is the most serious and potentially devastating chronic disorder of the pulmonary circulation with diverse etiologies and pathogenesis characterized by abnormal increased vasoconstriction and vascular remodelling. Current specific therapy of PH is based on an understanding of its pathogenesis and is acting through pathogenic pathways and therefore changes therapeutic strategy, effectively improves clinical course and prolongs life. The authors discuss the actual classification, pathogenesis in short and particularly actual treatment modalities and the impact on the natural history of this disorder. In chronic thromboembolic pulmonary hypertension is pulmonary endarterectomy if correct indicated the curable method, warranted substantial improvement of life quality and survival. These novel therapies of PH were absent in Slovakia until recently. The authors present initial experiences, results of PH management up to date on the basis of cooperation with PH centres in Austria and Czech Republic (Tab. 1, Fig. 6, Ref. 32).

Endothelial dysfunction and the clinical application

The vascular endothelium is a large organ that secretes numerous factors regulating vascular tone, cell growth, platelet and leukocyte interactions and thrombogenesis. Endothelial dysfunction is an early event in atherogenesis and is also important in establish coronary artery disease. Over the past decade a noninvasive technique has evolved to evaluate flow-mediated vasodilation, an endothelium-dependent function. Procedure is realised on the brachial artery. The stimulus provokes the endothelium to release nitric oxide with subsequent vasodilation that can be imaged and quantitated as the index of vasomotor function. (Fig. 1, Ref. 2.).

The internal mammary artery bypass--the principles of preoperative and postoperative diagnosis using colour-duplex ultrasound

BACKGROUND

The aim of the study was the assessment of functional characteristics of the left internal mammary artery (LIMA) bypass in patients after coronary artery bypass grafting (CABG) in comparison with the native LIMA using colour-duplex ultrasound as the non-invasive diagnostic method.

METHODS

We examined 303 patients after myocardial revascularization with the internal mammary artery bypass using the Hewllett Packard 2500, 5500 ultrasound units. Using the 7.5 MHz linear transducer we detected the LIMA from the left supraclavicular approach. We assessed the peak systolic velocity (PSV--cm/s), peak diastolic velocity (PDV--cm/s), end-diastolic velocity (EDV--cm/s) and we calculated the peak systolic/peak diastolic velocity ratio (SDVR) and resistance index RI (PSV-EDV/PSV). The obtained parameters were compared with the native LIMA flow characteristics of the 70 consecutive patients before CABG.

RESULTS

We observed the transformation of internal mammary artery flow from the predominantly systolic high resistance type of the native LIMA, to the low resistance biphasic waveform after its use as a coronary artery graft. We detected a significant increase of diastolic flow velocities and a significant decrease of resistance and of the SDVR ratio. In dysfunctional grafts we found a decrease of diastolic flow and an increase of LIMA resistance and SDVR.

CONCLUSION

The colour-duplex ultrasound is a perspective non-invasive method for the postoperative follow-up of patients with the LIMA graft. It allows the assessment of the bypass flow characteristics, functional status and patency and it could contribute to the early diagnosis of bypass failure. (Fig. 6, Tab. 4, Ref. 21.)

Value of echocardiography in results evaluation of transcatheter atrial septal defect closure in adults

Transcatheter closure of secundum atrial septal defect using Amplatzer occluder is accepted treatment modality. Transthoracic (TTE) and transoesophageal (TEE) echocardiography provides indispensable informations in the selection of eligible atrial septal defects, evaluates the exact size, location and morphology of the defect. In the closure procedure assistance of TEE enables precise determination of device size, correct placement of the device and immediate and follow-up closure results assessment. The present prospective study was performed in order to investigate the value of both approaches--TTE and TEE in the intermediate-term follow-up. Before, during transcatheter defect closure and in the follow-up echocardiography studies [TTE and TEE] were performed in 33 adult patients with secundum atrial septal defect with fulfilled TEE criteria. Correct placement of the device without interference with surrounding structures under TEE monitoring was possible in all patients. Immediate complete closure was achieved in 49% of patients, after 3 months in 94%. TEE findings corresponded well with TTE. In the follow-up echocardiographic signs of right ventricle overload retreated. Results indicate that TEE provides valued data for the selection and closure procedure. TTE is a sufficient reliable approach for results evaluation in intermediate follow-up. Echocardiography plays crucial role in the safety and efficacy assessment of transcatheter treatment of secundum atrial septal defect.

[80th anniversary of the Slovak Medical Society in Bratislava (1920-2000), and its significance in the development of medicine in Slovakia]

The establishment of the Slovak Medical Society (SMS) in Bratislava on 13th June 1920 (until 1939, the society was included into the Czechoslovak Medical Society) represents one of the most important milestones in the modern history of Slovak medicine. It was founded in direct consequence of the establishment of the first faculty of the Comenius University, namely the Medical Faculty. SMS began to issue its own journal Bratislavské lekárske listy (Bratislava Medical Journal) which was the first medical journal published in Slovakia after the origin of the Czechoslovak Republic. Eighty years of the existence of SMS which by its 2500 members forms the largest medical association, prove that the share of this society and its contribution to the development of Slovak medicine are essential. For many years, the society has been the only forum for Slovak physicians and scientific workers of the Medical Faculty where they could meet and increase their expertise. The society has witnessed also the significant material and moral support and co-operation between Czech and Slovak physicians during the period of the first Czechoslovak Republic.

[Cardiovascular diseases at the turn of the millenium]

The coronary disease of the heart (CDH) will be the most frequent cause of mortality and inability to work in the 21st century not only in industrially advanced countries but also in the developing countries. This unfavourable, assumedly paradoxical tendency persevering despite the significant progress in diagnosis and therapy is caused by two circumstances: ageing of population (prolonged mean life expectancy) and the increase in the number of individuals afflicted with (CDH) and living up to high age. In result of this development, the rapid increase in the prevalence of heart failure, especially in the aged, becomes the main cause of mortality, morbidity and hospitalisation.

[Heart transplantation--one possibility in the treatment of advanced congestive heart failure]

The authors present epidemiological data about congestive heart failure, its most common etiology and prognosis. They justify the performance of heart transplantation (HTx) in the treatment of congestive heart failure. They analyze the present state of HTx in the world and describe also the history of HTx in Slovakia. They present the review of contraindications and indications for the inclusion of recipients into the HTx programme and describe the further fates of these patients. They regard the HTx as an integral component of the therapeutical approach to the precisely defined group of patients with otherwise refractory congestive heart failure. (Tab. 4, Fig. 6, Ref. 38.)

[Vectorcardiographic and chronotopocardiographic study of septal hypoperfusion]

The study has been carried out in 73 patients (63 men and 10 women), aged between 22 and 59 years, suffering from angina pectoris. The localization in space of the extremities of the initial QRS vectors (10 and 20 ms) is an indicator which is relatively very sensitive to the disturbance in the myocardial irrigation in the regions around the septum and the adjacent ventricular wall. A good relationship has been found namely with the data obtained with thallium scintigraphy after effort. The sensitivity of the vectocardiographic method, like that of dipolar chronotopocardiography, was clearly superior to that of scalar graphs.