Browsing by Author "Milenković, Sanja (13406392200)"

Introduction Lateralization of brain functions such as language and manual dominance (hand preferences and fine motor control) are most likely under genetic control. However, this does not preclude the effect of various environmental factors on functional brain lateralization. A strong association of non-right-handedness (left- and mixed-handedness) with various neurodevelopmental conditions (e.g. schizophrenia, autism, Rett syndrome) implies that in some cases, non-right-handedness may be acquired rather than inherited (i.e., pathologically determined). Objective The aim of the study was: (a) re-investigation of several known risk factors for left-handedness (age of mother and/or father, twin pregnancies, and birth order), and (b) examination of hitherto uninvestigated factors (type of birth, Apgar score, maternal smoking during pregnancy). Methods Putative, causative environmental agents for this shift in manual distributions are explored in a sample of 1031 high school students (404 males and 627 females) from Belgrade. Both pre-existing (age of parents, twin pregnancy, and birth order) and new (Apgar score, maternal smoking, type of birth) putative agents are examined. Results We found that maternal smoking and low Apgar score (2-6) can significantly increase risk for lefthandedness (p=0.046 and p=0.042, respectively). The remaining factors showed no significant association with left-handedness in adolescents. Conclusion Our study clearly demonstrates that left-handedness may be related to maternal smoking during pregnancy and a low Apgar score on birth.

Lateralization is one of the central questions in neurology, neuropsychology, and other related scientific disciplines. There has been very little change in the proportion of left-handers since the Upper Paleolithic Age about 10,000 years ago and it is estimated to be around 10%. As the history of human thinking has developed from superstition to science, the explanation of left-handedness transformed from “devil’s work” to neurological specificity. This paper presents this very interesting historical change by analyzing the data on left-handedness and the attitudes towards it in human societies from prehistory to today. Even in a relatively open-minded society, parents and teachers may encourage a left-handed child to switch to right-handedness to make their lives easier in a largely right-handed world. On the other hand, left-handedness is increasingly seen as a special gift, and left-handed people have started to favor themselves as more competent in relation to the right-handed people. © 2019, Serbia Medical Society. All rights reserved.

To date, lateralization in living beings is a phenomenon almost mythologically unexplored. Scientists have proved that lateralization is not exclusively a human feature. Investigations in molecular biology, protein structure, mobility of bacteria, and intracellular lateralization in ciliates, shows important and universal nature of lateralization in living systems. Dominant lateralization implies the appearance of a dominant extremity, or a dominant sense during the performance of complex psychomotor activities. Hand dominance is usually defined as a tendency to use one hand rather than another to perform most activities and this is considered to be the most obvious example of cerebral lateralization and exclusive characteristic of humans. However, there are some exceptions in other species. The dominant hand is able to perform more complex and subtle manual tasks than the non-dominant hand, and this behavioral superiority is the absolute result of additional cerebral support. The asymmetry of brain organization was confirmed in rats, chimpanzees, dogs and birds, some fishes and lizards. The relationships between hand dominance with brain structure and function remain far from clear. For a long time, lateralization was considered unique to humans, but recently it has become clear that lateralization is a fundamental characteristic of the organization of brain and behavior in all vertebrates. It has been questioned to what extent lateralization in humans and other vertebrates may be comparable. © 2016. Srpski Arhiv za Celokupno Lekarstvo. All right reserved.

Hand dominance is defined as a proneness to use one hand rather than another in performing the majority of activities and this is the most obvious example of cerebral lateralization and an exclusive human characteristic. Left-handed people comprise 6-14% of the total population, while in Serbia, this percentage is 5-10%, moving from undeveloped to developed environments, where a socio-cultural pressure is less present. There is no agreement between investigators who in fact may be considered a left-handed person, about the percentage of left-handers in the population and about the etiology of left-handedness. In the scientific literature left-handedness has been related to health disorders (spine deformities, immunological disorders, migraine, neurosis, depressive psychosis, schizophrenia, insomnia, homosexuality, diabetes mellitus, arterial hypertension, sleep apnea, enuresis nocturna and Down Syndrome), developmental disorders (autism, dislexia and sttutering) and traumatism. The most reliable scientific evidences have been published about the relationship between left-handedness and spinal deformities in school children in puberty and with traumatism in general population. The controversy of other results in up-to-now investigations of health aspects of left-handedness may partly be explained by a scientific disagreement whether writing with the left hand is a sufficient criterium for left-handedness, or is it necessary to investigate other parameters for laterality assessment. Explanation of health aspects of left-handedness is dominantly based on Geschwind-Galaburda model about "anomalous" cerebral domination, as a consequence of hormonal disbalance.

Introduction Controversial results on the relationship between the left-handedness and neurotic disturbances have been obtained in so far investigations. Objective The aim of this study was to investigate the link between the left-handedness and neurotic disturbances in an adult urban population. Methods A cross-sectional study was performed on 1,202 adult residents of the Stari Grad municipality in Belgrade, out of which 401 were males (33,4%) and 801 were females (66,6%). A questionnaire was used as an investigation instrument, with questions concerning age, gender, writing hand and neurotic disturbances: tension, agressiveness, anger, nervousness, weepiness and seclusion. Results Left-handedness was found in 60 subjects (5%) and it was statistically more frequent in males (7.7%) compared to females (3.6%) (p=0.003). A decreasing trend of proportion of left-handed males was found in relation to aging. In the age group 18 to 39 years, agressiveness, as a specific neurotic disturbance, was significantly more frequent in left-handed males in comparison to right-handers (p=0.035). In the age group 40 to 59 years, neurotic disturbances were more common among left-handed males compared to right-handers (p=0.030). There were no significant diferences in the proportion of neurotic disturbances between the left-handed and the right-handed females. Conclusion From a public health point of view, left-handed men may be regarded as a relatively vulnerable population category concerning mental health.

Background: Precautionary allergen labels (PAL) should be used to indicate the possibility of allergen presence in the food. This study aimed to determine the prevalence and types of precautionary labeling statements on different pre-packaged food products in retail stores in Belgrade, Serbia, as well as to assess consumers’ attitudes and behavior towards PAL statements. Methods: This was a descriptive study. The following characteristics of 1404 pre-packaged foods were ana-lyzed: prevalence of PAL, listed food allergens on PAL, and the types of the advisory terminology. In the group of 275 participants (94 with food allergies, and 181 persons who purchasing food for a household member with food allergy) reading practice of PAL, purchasing practice based on PAL, and the opinion about PAL statements credibility were evaluated. Results: Overall, 33.9% of products had precautionary statements for one or more allergens. “Tree nuts” were the most common allergens listed in the PAL. The most common type of PAL was “May contain traces of x [allergen]” (52.7%). The PAL was always read by half of the participants. Less than half (43.3%) of the participants incorrectly believed that PAL is regulated by national law. A quarter of participants thought that the PAL statements are trustworthy. Conclusion: PAL statements frequently are not user-friendly and are not providing sufficient protection for food allergic patients. To gain buyers’ confidence, protect health and provide security, the necessity for the strategies that would regulate PAL by the law exists. © 2022 Davidović et al. Published by Tehran University of Medical Sciences.

Background: Although behavioural dominance of the right hand in humans is likely to be under genetic control, departures from this population norm, i.e. left- or non-right-handedness, are believed to be influenced by environmental factors. Among many such environmental factors including, for example, low birth weight, testosterone level, and maternal age at birth, season of birth has occasionally been investigated. The overall empirical evidence for the season of birth effect is mixed. Methods: We have investigated the effect of season of birth in an epidemiologically robust sample of randomly selected young people (n = 977), all born in the same year. A Kolmogorov-Smirnov type statistical test was used to determine season of birth. Results: Neither the right-handed nor the non-right-handed groups demonstrated birth asymmetry relative to the normal population birth distribution. There was no between-group difference in the seasonal distribution of birth when comparing the right-handed to the non-right-handed groups. Conclusion: The present study failed to provide support for a season of birth effect on atypical lateralisation of handedness in humans. © 2008 Milenković et al; licensee BioMed Central Ltd.

Throughout human history left-handedness has been considered as sinful. It has been associated with the devil, weakness, female gender, unhealthiness, evil, something that has to be turned to a "good" - right side by force. Left-handedness is being more and more acceptable at rational level, but in everyday life it is still considered to be unusual if someone writes with the left hand. Lessening of the number of lefthanders is associated with ageing. There are about 13% lefthanders among people in twenties and less than 1% lefthanders among those in eighties. This finding may be explaned with more pronounced socio-cultural pressure on left-handed people in the past, compared to nowadays. On the other hand, this may also support the hypothesis about a reduced life span of lefthanded people. With cross-exercising of left-handedness, certain typical characteristics and behavioural patterns appear in these people. This was a sort of provoked behaviour and an attack on the integrity of an emotional attitude toward oneself. Stuttering may also appear as a consequence of unsuccessful cross-exercising of left-handedness. The hypothesis about left-handedness as an advantage is supported with the reports about relatively more lefthanders in some specific groups such as: mathematicians, sculptors, architects, painters, musicians, actors, tennis players, as well as famous army commanders and rulers.