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Lege Artis Medicinae

JANUARY 20, 2019

[Biological rhythms and ageing ]

PUREBL György

[Biological rhythms plays key role in maintaining health and preventing diseases. The changes of rhythms are normally associated to aging. Biological rhythms become more fragile along with the age and therefore they are connected to various age-related health problems. The interest about the strategies aiming to maintain or restore biological rhythms is increasing. There are evidences about the beneficial effect of rhythm restoration therapies in dementia and depression, but future studies are needed to clarify the general health promoting and also geroprotecting effect of these interventions. ]

Lege Artis Medicinae

JUNE 15, 2012

[Asserting basis-bolus principle by analogue insulin preparations in pre-pubertal child with diabetes]

BLATNICZKY László

[INTRODUCTION - The choice of insulin combination therapy in children with type 1 diabetes mellitus is determined basically by the diet as well as the age of the patient. However, life rhythms of individual children are widely different. As a consequence, insulin therapy must be tailored to individual needs, by chosing the optimal one from the available insulin products with different efficacy curves. The aim is, of course, to maintain near-normoglycaemia for years or decades. CASE STUDY - The author presents the case of a 10-year-old girl with diabetes for 4 years, whose insulin treatment has involved a number of combinations. Good metabolic balance could be obtained by premixed insulin preparations for more than two years. However, subsequent intensive treatment with human insulins had poor results. This was primarily due to the fact that the child had a rather hectic daily schedule and eating habits, although she ate - appropriately for her age - six meals per day. After changing the ratios of the meals while maintaining her six-mealsper- day regime, an analogue glargine/glulisine combination therapy was induced, with a significant increase in the basal/ bolus ratio. This treatment was successful: HbA1c level got to the target range, without changes - theoretically caused by the rapid analogue - in hypo- and hyperglycaemic periods before and after small meals, respectively. CONCLUSION - During the time of remission, treatment with premixed human insulin can maintain good metabolic balance even for years, while saving (at least) two pricks per day. Insulin treatment intensified by analogue insulins (glulisine/glargine) may be attempted in prepubertal children needing six meals a day, provided their lifestyle raises problems. Glargine, given in an increased ratio, can compensate the hyperglycaemic effect of minimised small meals.]

Hypertension and nephrology

FEBRUARY 20, 2012

[Chronotherapy of hypertension - individualized treatment according to the circadian blood pressure profile]

SZAUDER Ipoly, UJHELYI Gabriella

[The circadian (24 h) rhythm shows great importance in the pharmacotherapy of hypertension. There is growing interest in how to best tailor the treatment of hypertensive patients according to the circadian blood pressure pattern of each individual. Significant administration-time differences are in the chronokinetics of antihypertensive medication. The therapeutic coverage and efficacy of different antihypertensive drugs are all markedly dependent on the circadian time of drug administration. Administration of ACE inhibitors, ARBs, doxazosin and aspirin at bedtime, as opposed to upon wakening, results in an improved diurnal/nocturnal blood pressure ratio (recommended for nondipper type of hypertension). Other antihypertensive medications: calcium channel blockers and β receptor blockers are non effective at the circadian blood pressure pattern. Chronotherapy provides a means of individualizing the treatment of hypertension according to the circadian blood pressure profile of patients and constitutes a new option to optimize blood pressure control and reduce the risk of cardiovascular disease and the risk of end organ injury.]

Lege Artis Medicinae

DECEMBER 21, 2011

[Occurrence of cardiometabolic risk factors among shift workers]

JERMENDY György, NÁDASI Judit, HEGYI Ilona, VASAS István, HIDVÉGI Tibor

[INTRODUCTION - Shift workers have an impaired circadian rhythm, which might have an adverse effect on their health. In order to assess cardiometabolic risk in shift workers, a cross-sectional study was performed among active workers (aged 25-66 years, with a minimal shift working experience of 5 years). METHODS - In total 481 workers (121 men, 360 women) registered by the occupational health service were enrolled in our study. Most participants worked in the light industry (58.2%) or in public service (23.9%). Following questionnaire-based data recording, anthropometric measurements and physical examination were performed and fasting venous blood sample was taken for measuring laboratory parameters. Data from shift workers (n=234, 54 men and 180 women, age: 43.9±8.1 years) were compared with those of day workers (n=247, 67 men and 180 women, age: 42.8±8.5 years). RESULTS - Compared with day workers, shift workers had bigger weight (76.6±16.1 vs 73.9±17.6 kg; p<0.05), higher BMI index (27.5±5.3 vs 26.0±4.9 kg/m2; p<0.01) and systolic blood pressure (123±19 vs 119±16 mmHg, p<0.01), and higher prevalence rate of diabetes (4.3 vs 1.2 %; p<0.05) and cardiovascular diseases (3.8 vs 0.8 %; p<0.05). In addition, the proportion of participants who performed regular physical activity was lower (20.6 vs 38.7 %; p<0.001) and that of current smokers were higher (35.0 % vs 19.5 %; p<0.001) in shift workers than in day workers. In laboratory findings, only one difference has been found: HDL-cholesterol level was lower among women (shift workers versus workers: 1.56±0.32 vs 1.68±0.36 mmol/l; p<0.01). CONCLUSION - Long-term shift work (day-night) results in a less healthy lifestyle and worse cardiometabolic risk factors compared with day work. Thus, our study highlights the importance of measures for preventing cardiovascular diseases in shift workers.]

Clinical Neuroscience

MAY 20, 2011

[The role of sleep dynamics and delta homeostasis in cognitive functions]

HALÁSZ Péter

[The paper is aimed to introduce the neuronal network basis of dynamic sleep processes, including the micro-structure of sleep and the relationship of sleep dynamics with homeostatic regulation and plastic changes during sleep. Newer studies tend to show that beyond the wellknown long-term homeostatic and circadian regulation of NREM sleep, sleep is regulated by a stimulus and arousal dependent flexible defense system, the elements of which participate in sleep delta homeostasis. Within the EEG elements of sleep a more larger amount represents reactible type as it was thought previously.. Both the events of wake state and sensory input during sleep are shaping the sleep EEG in a function- and localisation specific way and the next day cognitive functios are determined by these changes.]

Clinical Neuroscience

MARCH 20, 2007

[SYNAPTIC CONNECTIONS OF GLUTAMATERGIC NERVE FIBRES IN THE RAT SUPRACHIASMATIC NUCLEUS]

KISS József, CSÁKI Ágnes, CSABA Zsolt, HALÁSZ Béla

[Background and purpose - The hypothalamic suprachiasmatic nucleus functioning as the principal circadian pacemaker in mammals, has a rich glutamatergic innervation. Nothing is known about the terminations of the glutamatergic fibres. The aim of the present investigations was to study the relationship between glutamatergic axon terminals and vasoactive intestinal polypeptide (VIP), GABA and arginine-vasopressin (AVP) neurons in the cell group. Methods - Double label immunocytochemistry was used and the brain sections were examined under the electron microscope. Vesicular glutamate transporter type 2 was applied as marker of the glutamatergic elements. Results - Glutamatergic fibers were detected in synaptic contact with GABAergic, VIP- and AVP-positive neurons forming asymmetric type of synapses. Conclusion - The findings are the first data on the synaptic contacts of glutamatergic axon terminals with neurochemically identified neurons in the suprachiasmatic nucleus.]

Clinical Neuroscience

DECEMBER 10, 2005

[PSYCHOPHYSIOLOGICAL AND CLINICAL ASPECTS OF THE EEG SYNCHRONIZATION RELATED TO COGNITIVE PROCESSES]

MOLNÁR Márk, CSUHAJ Roland, CSIKÓS Dóra, HAMVAI Csaba, CZIGLER Balázs, BÁLINT Andrea, GAÁL Zsófia Anna

[The authors review the various forms of EEG-synchronization with special emphasis on the characteristics of the induced and enhanced rhythms. The suggested role of the various EEG frequency bands in the cognitive processes is demonstrated by examples from the literature. The relationship between linear and nonlinear electrophysiological complexity and EEG synchronization is analyzed, with a touch on the use of Omega-complexity and synchronization likelihood methods. In the present study the EEG recorded during adding and subtracting tasks was analyzed with the above methods. It was found that during the adding task the theta band increased in the frontal area, which may be related to activation of working memory processes. Mapping the scalp-distribution of synchronization likelihood also confirmed increased synchronization in the frontal area in addition to which increased values were found in the left temporo-parietal area. The analysis of linear and nonlinear EEG synchronization associated with cognitive processing is suitable to explore the task-related and region specific features of these events.]

Lege Artis Medicinae

JANUARY 20, 2003

[Advances in sleep diagnostics]

HORVÁTH Róbert

[Despite the insufficient financial support, the number of the laboratories for sleep diagnostics and the examined patients are rising. The CPAP (Continuous Positive Airway Pressure) equipment playing the main role in the treatment of the obstructive sleep apnoe syndrome (OSAS) is recently available from three neurological centres (Budapest, Debrecen, Pécs). These centres can prescribe the machine as a ”model experiment” with 85% support given by the State Health Care. The increase of the number of the licensed hospitals is expected in the near future, the only condition is the polysomnography background. Differential diagnostics (narcolepsy, RLS, PLMS, sleepdependent laryngospasm, disorders of the circadian rhythm) and the follow-up of the CPAP using patients (indication, contraindication, compliance, CPAP pressure setting, CPAP therapy control) have been emphasized.]

Clinical Neuroscience

JANUARY 30, 2010

[How does the brain create rhythms?]

SZIRMAI Imre

[Connection was found between rhythmic cortical activity and motor control. The 10 Hz μ-rhythm and the 20-30 Hz bursts represent two functional states of the somatomotor system. A correspondence of the central μ-rhythm of the motor cortex and the physiological hand tremor (8-12 Hz) is presumed. The precise tuning of the motor system can be estimated by the frequency of repetitive finger movements. In complex tapping exercise, the index finger is the most skillful, the 3rd, 4th and 5th fingers keep rhythm with less precision. It was found that the organization of mirror movements depends on the cortical representation of fingers. Mirror finger movements are more regular if the subject begins the motor action with the 5th (small) finger. Concerning cortical regulation of finger movements, it was suggested that there are two time-keeping systems in the brain; one with a sensitivity above and another with a sensitivity below the critical frequency of 3 Hz. The preferred meter which helps to maintain synchronous finger movements is the cadence of 4/4 and 8/8. We observed that the unlearned inward-outward sequential finger movement was equally impaired in nonmusician controls and patients with Parkinson-disease. In movement disorders, the ability of movement and the “clock-mechanism” are equally involved. The polyrhythmic finger movement is not our inborn ability, it has to be learned. The “timer” function, which regulates the rhythmic movement, is presumably localised in the basal ganglia or in the cerebellum. The meter of the music is built on the reciprocal values of 2 raised to the second to fifth power (1/12, 1/22, 1/23, 1/24, 1/25). The EEG frequencies that we consider important in the regulation of cons-cious motor actions are approximately in the same domain (4, 8, 16, 32, 64 Hz). During music performance, an important neural process is the coupling of distant brain areas. Concerning melody, the musical taste of Europeans is octavebased. Musical ornaments also follow the rule of the gothic construction, that is: pursuit of harmony towards the single one rising from the unification of 8-4-2 classes. Leibnitz concerned music as the unconscious mathematics of the soul. Movement-initiating effect of music is used in rehabilitation of patients with movement disorders. The meter and rhythm have superiority over the melody. It is possible that rhythmic movements can be generated also in the absence of sensory input and the central oscillators can produce “fictive motor patterns”.]

Lege Artis Medicinae

JULY 27, 2009

[Melatonin, sleep and the circadian rhythm: theoretical considerations and their chronopharmacological applications ]

BÓDIZS Róbert

[The predictive homeostasis of living organisms is an anticipatory adaptation to rhythmical environmental changes. A good example for this is the circadian rhythm preparing the organism for the alternation of day and night. The circadian rhythm of melatonin production anticipates the timing and duration of nocturnal sleep of human subjects. It also induces a sleep-like stimulusprocessing mode of the brain and - in case of adequate environmental circumstances - a soporific and in part, a sleep-inducing effect. Specificities of melatonin effects on sleep are the reduction of slow-wave EEG activity, as well as the increase in seep EEG spindling and REM sleep time. Like other substances with hypnotic properties, melatonin decreases core body temperature, but has also a strong chronobiotic effect that is expressed as rapid and strong phase shifts of the circadian rhythm, depending on the time of day of melatonin administration. Because light acutely suppresses melatonin production, adequately timed light exposition, containing also low wavelength components, together with exogenous melatonin, could be useful in treating jet-lag syndrome and other circadian rhythm disorders.]