Browsing by Author "Hrncic, Dragan (13907639700)"

The assessment of pain sensitivity in humans has been standardized using quantitative sensory testing, whereas in animals mostly paw withdrawal thresholds to diverse stimuli are measured. This study directly compares tests used in quantitative sensory testing (pinpricks, pressure algometer) with tests used in animal studies (electronic von Frey test: evF), which we applied to the dorsal hind limbs of humans after high frequency stimulation and rats after tibial nerve transection. Both experimental models induce profound mechanical hypersensitivity. At baseline, humans and rats showed a similar sensitivity to evF with 0.2 mm diameter tips, but significant differences for other test stimuli (all P < 0.001). When expressed as force divided by circumference, baseline thresholds for 0.8 mm probes were higher than for 0.2 mm in both species (both P < 0.001) suggesting spatial summation. At similar probe diameters, ramped stimuli showed higher baseline thresholds than stepped stimuli (P < 0.01) but similar sensitivity to change. For ramped stimuli sensitivity to change was higher with small probe tips than large blunt tips in both pain models (P < 0.01 in rat, P < 0.05 in humans). These data show that rat paw withdrawal threshold to punctate stimuli (0.2 mm diameter) can be used as surrogate parameters for human mechanical pain sensitivity, but probe size and shape should be standardized. Hypersensitivity to blunt pressure - the leading positive sensory sign after peripheral nerve injury in humans - is a novel finding in the tibial nerve transection model. By testing outside the primary zone of nerve damage (rat) or activation (humans), our methods likely involve effects of central sensitization in both species. © 2016 International Association for the Study of Pain.

The assessment of pain sensitivity in humans has been standardized using quantitative sensory testing, whereas in animals mostly paw withdrawal thresholds to diverse stimuli are measured. This study directly compares tests used in quantitative sensory testing (pinpricks, pressure algometer) with tests used in animal studies (electronic von Frey test: evF), which we applied to the dorsal hind limbs of humans after high frequency stimulation and rats after tibial nerve transection. Both experimental models induce profound mechanical hypersensitivity. At baseline, humans and rats showed a similar sensitivity to evF with 0.2 mm diameter tips, but significant differences for other test stimuli (all P < 0.001). When expressed as force divided by circumference, baseline thresholds for 0.8 mm probes were higher than for 0.2 mm in both species (both P < 0.001) suggesting spatial summation. At similar probe diameters, ramped stimuli showed higher baseline thresholds than stepped stimuli (P < 0.01) but similar sensitivity to change. For ramped stimuli sensitivity to change was higher with small probe tips than large blunt tips in both pain models (P < 0.01 in rat, P < 0.05 in humans). These data show that rat paw withdrawal threshold to punctate stimuli (0.2 mm diameter) can be used as surrogate parameters for human mechanical pain sensitivity, but probe size and shape should be standardized. Hypersensitivity to blunt pressure - the leading positive sensory sign after peripheral nerve injury in humans - is a novel finding in the tibial nerve transection model. By testing outside the primary zone of nerve damage (rat) or activation (humans), our methods likely involve effects of central sensitization in both species. © 2016 International Association for the Study of Pain.

The aim of this study was to examine the effects of a methionine-enriched diet on anxiety-related behavior in rats and to determine the role of the brain oxidative status in these alterations. Adult male Wistar rats were fed from the 30th to 60th postnatal day with standard or methionine-enriched diet (double content comparing with standard diet: 7.7 g/kg). Rats were tested in open field and light-dark tests and afterwards oxidative status in the different brain regions were determined. Hyperhomocysteinemia induced by methionine-enriched diet in this study decreased the number of rearings, as well as the time that these animals spent in the center of the open field, but increased index of thigmotaxy. Oxidative status was selectively altered in the examined regions. Lipid peroxidation was significantly increased in the cortex and nc. caudatus of rats developing hyperhomocysteinemia, but unaltered in the hippocampus and thalamus. Based on the results of this research, it could be concluded that hyperhomocysteinemia induced by methionine nutritional overload increased anxiety-related behavior in rats. These proanxiogenic effects could be, at least in part, a consequence of oxidative stress in the rat brain. © 2016, Canadian Science Publishing. All rights reserved.

The aim of this study was to examine the effects of a methionine-enriched diet on anxiety-related behavior in rats and to determine the role of the brain oxidative status in these alterations. Adult male Wistar rats were fed from the 30th to 60th postnatal day with standard or methionine-enriched diet (double content comparing with standard diet: 7.7 g/kg). Rats were tested in open field and light-dark tests and afterwards oxidative status in the different brain regions were determined. Hyperhomocysteinemia induced by methionine-enriched diet in this study decreased the number of rearings, as well as the time that these animals spent in the center of the open field, but increased index of thigmotaxy. Oxidative status was selectively altered in the examined regions. Lipid peroxidation was significantly increased in the cortex and nc. caudatus of rats developing hyperhomocysteinemia, but unaltered in the hippocampus and thalamus. Based on the results of this research, it could be concluded that hyperhomocysteinemia induced by methionine nutritional overload increased anxiety-related behavior in rats. These proanxiogenic effects could be, at least in part, a consequence of oxidative stress in the rat brain. © 2016, Canadian Science Publishing. All rights reserved.

The aim of the study was to compare the effects of high-intensity interval training (HIIT) and nutrition advice on cardiometabolic biomarkers, hormonal parameters, and cardiorespiratory fitness in adolescent girls with obesity. Adolescent girls with obesity (n = 44, aged 13–19 years) were randomized into a 12-week intervention as follows: (i) dietary advice and HIIT (n = 22), and (ii) dietary advice only (n = 22). The concentration of biomarkers of inflammation, biochemical and hormonal testing, oral glucose tolerance test, cardiorespiratory fitness, physical activity levels, and nutrition were assessed. After a 3-month intervention, the diet+HIIT group significantly increased insulin sensitivity index (–0.34 ± 1.52 vs. 1.05 ± 3.21; p = 0.001) and work load (0.6 ± 11.3 W vs. 14.6 ± 20.2 W; p = 0.024) and decreased glucose area under the curve (–0.29 ± 4.69 vs. −0.98 ± 4.06; p = 0.040), insulin area under the curve (−9.65 ± 117.9 vs. −98.7 ± 201.8; p = 0.003), and high-sensitivity C-reactive protein (hs-CRP) (0.12 ± 1.92 mg/L vs. −1.47 ± 3.67 mg/L; p = 0.039) in comparison with the diet group. Regarding within-group changes, both groups had significant improvements in body mass index (BMI), BMI-standard deviation score, body fat percentage, and systolic blood pressure. Positive impact on waist circumference, waist circumference/height ratio, diastolic blood pressure, hs-CRP, work load, maximal heart rate, and resting heart rate was observed only after the diet+HIIT intervention. No significant change was noted in peak oxygen uptake, lipid profile, and hormonal parameters between groups after intervention. Novelty • HIIT and nutrition advice increased insulin sensitivity and decreased BMI, bodyfat, systolicbloodpressure, and diastolicblood pressure. • Nutrition advice decreased BMI, body fat, and systolic blood pressure in adolescent girls with obesity. © 2020, Canadian Science Publishing. All rights reserved.

The aim of the study was to compare the effects of high-intensity interval training (HIIT) and nutrition advice on cardiometabolic biomarkers, hormonal parameters, and cardiorespiratory fitness in adolescent girls with obesity. Adolescent girls with obesity (n = 44, aged 13–19 years) were randomized into a 12-week intervention as follows: (i) dietary advice and HIIT (n = 22), and (ii) dietary advice only (n = 22). The concentration of biomarkers of inflammation, biochemical and hormonal testing, oral glucose tolerance test, cardiorespiratory fitness, physical activity levels, and nutrition were assessed. After a 3-month intervention, the diet+HIIT group significantly increased insulin sensitivity index (–0.34 ± 1.52 vs. 1.05 ± 3.21; p = 0.001) and work load (0.6 ± 11.3 W vs. 14.6 ± 20.2 W; p = 0.024) and decreased glucose area under the curve (–0.29 ± 4.69 vs. −0.98 ± 4.06; p = 0.040), insulin area under the curve (−9.65 ± 117.9 vs. −98.7 ± 201.8; p = 0.003), and high-sensitivity C-reactive protein (hs-CRP) (0.12 ± 1.92 mg/L vs. −1.47 ± 3.67 mg/L; p = 0.039) in comparison with the diet group. Regarding within-group changes, both groups had significant improvements in body mass index (BMI), BMI-standard deviation score, body fat percentage, and systolic blood pressure. Positive impact on waist circumference, waist circumference/height ratio, diastolic blood pressure, hs-CRP, work load, maximal heart rate, and resting heart rate was observed only after the diet+HIIT intervention. No significant change was noted in peak oxygen uptake, lipid profile, and hormonal parameters between groups after intervention. Novelty • HIIT and nutrition advice increased insulin sensitivity and decreased BMI, bodyfat, systolicbloodpressure, and diastolicblood pressure. • Nutrition advice decreased BMI, body fat, and systolic blood pressure in adolescent girls with obesity. © 2020, Canadian Science Publishing. All rights reserved.

Objective: To measure fetal and maternal plasma homocysteine (Hcy) concentrations in uncomplicated pregnancies. Methods: Paired maternal venous and fetal umbilical cord blood (n = 81) samples were evaluated for plasma Hcy and vitamin B12 levels, in addition to eight neonatal umbilical cord blood samples obtained immediately following delivery. Results: Both fetal and maternal Hcy concentrations were positively correlated with advancing gestational age (ρ = 0.44, p < 0.0001; and ρ = 0.27, p < 0.05, respectively). Fetal plasma Hcy concentrations [2.2 μmol/l (IQR: 2.0-3.2)] were significantly lower than both neonatal umbilical vein [5.0 μmol/l (IQR: 4.4-6.5); p < 0.001] and maternal plasma Hcy levels [4.4 μmo/l (IQR: 3.4-5.4); p < 0.001]. In addition, Hcy values at term were higher in the umbilical vein compared with the umbilical artery [5.0 μmol/l (IQR: 3.4-5.4) versus 4.2 μmol/l (IQR: 3.7-5.5), respectively; p = 0.016]. Significant correlation was noted and between fetal and maternal Hcy levels (ρ = 0.50, p < 0.0001), while fetal Hcy was negatively correlated with maternal B12 concentrations (ρ = -0.32, p < 0.001). Conclusions: Fetal Hcy levels were significantly lower than maternal and neonatal levels and correlated with gestational age across the second half of pregnancy. © 2014 Informa UK Ltd. All rights reserved.

Neuroactive steroids are a type of steroid hormones produced within the nervous system or in peripheral glands and then transported to the brain to exert their neuromodulatory effects. Neuroactive steroids have pleiotropic effects, that include promoting myelination, neuroplasticity, and brain development. They also regulate important physiological functions, such as metabolism, feeding, reproduction, and stress response. The homoeostatic processes of metabolism and reproduction are closely linked and mutually dependent. Reproductive events, such as pregnancy, bring about significant changes in metabolism, and metabolic status may affect reproductive function in mammals. In females, the regulation of reproduction and energy balance is controlled by the fluctuations of oestradiol and progesterone throughout the menstrual cycle. Neurosteroids play a key role in the neuroendocrine control of reproduction. The synthesis of neuroestradiol and neuroprogesterone within the brain is a crucial process that facilitates the release of GnRH and LH, which in turn, regulate the transition from oestrogen-negative to oestrogen-positive feedback. In addition to their function in the reproductive system, oestrogen has a key role in the regulation of energy homoeostasis by acting at central and peripheral levels. The oestrogenic effects on body weight homoeostasis are primarily mediated by oestrogen receptors-α (ERα), which are abundantly expressed in multiple brain regions that are implicated in the regulation of food intake, basal metabolism, thermogenesis, and brown tissue distribution. The tight interplay between energy balance and reproductive physiology is facilitated by shared regulatory pathways, namely POMC, NPY and kisspeptin neurons, which are targets of oestrogen regulation and likely participate in different aspects of the joint control of energy balance and reproductive function. The aim of this review is to present a summary of the progress made in uncovering shared regulatory pathways that facilitate the tight coupling between energy balance and reproductive physiology, as well as their reciprocal interactions and the modulation induced by neurosteroids. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2024.

Neuroactive steroids are a type of steroid hormones produced within the nervous system or in peripheral glands and then transported to the brain to exert their neuromodulatory effects. Neuroactive steroids have pleiotropic effects, that include promoting myelination, neuroplasticity, and brain development. They also regulate important physiological functions, such as metabolism, feeding, reproduction, and stress response. The homoeostatic processes of metabolism and reproduction are closely linked and mutually dependent. Reproductive events, such as pregnancy, bring about significant changes in metabolism, and metabolic status may affect reproductive function in mammals. In females, the regulation of reproduction and energy balance is controlled by the fluctuations of oestradiol and progesterone throughout the menstrual cycle. Neurosteroids play a key role in the neuroendocrine control of reproduction. The synthesis of neuroestradiol and neuroprogesterone within the brain is a crucial process that facilitates the release of GnRH and LH, which in turn, regulate the transition from oestrogen-negative to oestrogen-positive feedback. In addition to their function in the reproductive system, oestrogen has a key role in the regulation of energy homoeostasis by acting at central and peripheral levels. The oestrogenic effects on body weight homoeostasis are primarily mediated by oestrogen receptors-α (ERα), which are abundantly expressed in multiple brain regions that are implicated in the regulation of food intake, basal metabolism, thermogenesis, and brown tissue distribution. The tight interplay between energy balance and reproductive physiology is facilitated by shared regulatory pathways, namely POMC, NPY and kisspeptin neurons, which are targets of oestrogen regulation and likely participate in different aspects of the joint control of energy balance and reproductive function. The aim of this review is to present a summary of the progress made in uncovering shared regulatory pathways that facilitate the tight coupling between energy balance and reproductive physiology, as well as their reciprocal interactions and the modulation induced by neurosteroids. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2024.