Vedrana Ivić

Background/Objectives: The ketogenic diet (KD) induces profound metabolic shifts, yet the sex-specific long-term effects on skeletal muscle metabolism and sterol homeostasis across tissues remain insufficiently characterized. This study tested the hypothesis that a prolonged KD would elicit distinct, sex-dependent metabolic and sterol adaptations in mice. Methods: We examined how a 12-week KD, compared with a standard diet, affected body mass, the skeletal muscle metabolome, hepatic lipid and collagen content, and sterol profiles in the skeletal muscle, liver, spleen, and serum in male and female C57BL/6J mice. Three-month-old mice of both sexes were randomized to a KD or standard diet and evaluated using the histological quantification of hepatic steatosis and collagen deposition, matrix-assisted laser desorption/ionization time-of-flight imaging mass spectrometry (MALDI-TOF IMS) of skeletal muscle, and LC-MS/MS-based sterol profiling. Results: The KD induced rapid body mass gain in males and delayed weight gain in females, promoted hepatic steatosis in both sexes, and generated clearly segregated, sex- and diet-specific skeletal muscle metabolomic signatures. These signatures included reduced tricarboxylic acid cycle precursors and a marked decrease in S-adenosylmethionine in KD-fed females. Across tissues, the KD consistently suppressed precursor sterols, including 7-dehydrocholesterol and desmosterol in the skeletal muscle, liver, and spleen, while elevating serum cholesterol and desmosterol (male-biased), with changes generally more pronounced in males. Conclusions: Collectively, these findings demonstrate that a long-term KD drives sex- and organ-specific metabolic remodeling, with evidence of greater metabolic flexibility but a shared risk of hepatic steatosis in females. These results underscore the importance of personalized, sex-stratified approaches when considering long-term ketogenic interventions.

Cortisol is built into the circadian clock mechanism, but it is also the body’s natural response to stress. Insight into sex-specific cortisol fluctuations may elucidate individual differences in physiological and pathological patterns. This cross-sectional study examined sex-specific adaptation to stress induced by COVID-19 pandemic and lockdown in foreign medical students at I. Horbachevsky Ternopil National Medical University, Ukraine (TNMU). Salivary cortisol was analyzed using cluster-based mathematical modeling to identify natural groupings in the data. Perceived stress was measured using Perceived stress scale-10 (PSS-10). The academic success was accessed from the official records of the TNMU. Average value of area under the curve (AUC) of daily salivary cortisol from the whole sample showed that men had higher cortisol than women. Mathematical clustering explained shift of the cortisol peak, and divided sample into 5 clusters—two of which had predicted daily cortisol pattern and represented most participants (65.6% men and 73.6% women), while the rest had aberrant daily cortisol pattern. Females had higher total PSS-10 score than males. PSS-10 subscales correlated with aberrant daily cortisol pattern. Unexpectedly, COVID-related circumstances did not have impact on participants’ academic success.

Pregnancy presents specific metabolic demands, and disruption caused by a high-fat high-sugar diet (HFHSD) have been associated with significant complications, including maternal health risk, fetal developmental issues, and infertility. Obesity-related changes in the uterine tissues may contribute to these challenges. This study analyzed structural changes in the uterus and adipose tissue of pregnant rats on gestation day 22 fed an HFHSD using various staining techniques. Hematoxylin and eosin staining showed morphological changes in the adipose tissue and the uterine structure, including the lumen size and the thickness of the myometrium, endometrium, and perimetrium. The amount of collagen in the uterus was determined by PicroSirius red staining, while PAS-D staining was used to observe glycogen content. Key protein expressions, such as insulin and leptin receptors and UCP1 and UCP3, were analyzed by immunohistochemistry. The HFHSD promoted hypertrophy of visceral and gonadal adipocytes, suggesting metabolic alterations. By the end of pregnancy, a significant reduction in uterine lumen size was observed. Additionally, a decrease in insulin and higher leptin receptor expressions in the myometrium indicated significant physiological alteration. These findings offer insight into how an HFHSD affects uterine structure and function during late pregnancy but should be interpreted within the physiological context of gestation-related metabolic changes. Further research is needed to understand the functional consequences of these alterations on reproductive and metabolic health.

Anesthetics are essential agents that are frequently used in clinical practice to induce a reversible loss of consciousness and sensation by depressing the central nervous system. The inhalational anesthetics isoflurane and sevoflurane are preferred due to their rapid induction and recovery times and ease of administration. Despite their widespread use, the exact molecular mechanisms by which these anesthetics induce anesthesia are not yet fully understood. In this study, the age-dependent effects of inhalational anesthetics on two demyelination models were investigated: congenital (B4galnt1-null) and chemically induced (cuprizone). Various motor and cognitive tests were used to determine sensitivity to isoflurane and sevoflurane anesthesia. B4galnt1-null mice, which exhibit severe motor deficits due to defects in ganglioside synthesis, showed significant impairments in motor coordination and balance in all motor tests, which were exacerbated by both anesthetics. Cuprizone-treated mice, which mimic the demyelination in B4galnt1-null mice, also showed altered, age-dependent sensitivity to anesthesia. The study showed that older mice exhibited more pronounced deficits, with B4galnt1-null mice showing the greatest susceptibility to sevoflurane. These differential responses to anesthetics suggest that age and underlying myelin pathology significantly influence anesthetic effects.

Ageing is a complex biological process with variations among individuals, leading to the development of ageing clocks to estimate biological age. Glycans, particularly in immunoglobulin G (IgG), have emerged as potential biomarkers of ageing, with changes in glycosylation patterns correlating with chronological age.For precision analysis, three different plasma pools were analysed over 26 days in tetraplicates, 312 samples in total. In short-term variability analysis, two cohorts were analysed: AstraZeneca MFO cohort of 26 healthy individuals (median age 20) and a cohort of 70 premenopausal Chinese women (median age 22.5) cohort monitored over 3 months. Long-term variability analysis involved two adult men aged 47 and 57, monitored for 5 and 10 years, respectively. Samples were collected every 3 months and 3 weeks, respectively. IgG N-glycan analysis followed a standardized approach by isolating IgG, its subsequent denaturation and deglycosylation followed by glycan cleanup and labelling. Capillary gel electrophoresis with laser-induced fluorescence (CGE-LIF) and ultra-performance liquid chromatography analyses were employed for glycan profiling. Statistical analysis involved normalization, batch correction, and linear mixed models to assess time effects on derived glycan traits.The intermediate precision results consistently exhibited very low coefficient of variation values across all three test samples. This consistent pattern underscores the high level of precision inherent in the CGE method for analysing the glycan clock of ageing. The AstraZeneca MFO cohort did not show any statistically significant trends, whereas the menstrual cycle cohort exhibited statistically significant trends in digalactosylated (G2), agalactosylated (G0) and fucosylation (F). These trends were attributed to the effects of the menstrual cycle. Long-term stability analysis identified enduring age-related trends in both subjects, showing a positive time effect in G0 and bisected N-acetylglucosamine, as well as a negative time effect in G2 and sialylation, aligning with earlier findings. Time effects measured for monogalactosylation, and F remained substantially lower than ones observed for other traits.The study found that IgG N-glycome analysis using CGE-LIF exhibited remarkably high intermediate precision. Moreover, the study highlights the short- and long-term stability of IgG glycome composition, coupled with a notable capacity to adapt and respond to physiological changes and environmental influences such as hormonal changes, disease, and interventions. The discoveries from this study propel personalized medicine forward by deepening our understanding of how IgG glycome relates to age-related health concerns. This study underscores the reliability of glycans as a biomarker for tracking age-related changes and individual health paths.

Lipid rafts, specialised microdomains within cell membranes, play a central role in orchestrating various aspects of neurodevelopment, ranging from neural differentiation to the formation of functional neuronal networks. This review focuses on the multifaceted involvement of lipid rafts in key neurodevelopmental processes, including neural differentiation, synaptogenesis and myelination. Through the spatial organisation of signalling components, lipid rafts facilitate precise signalling events that determine neural fate during embryonic development and in adulthood. The evolutionary conservation of lipid rafts underscores their fundamental importance for the structural and functional complexity of the nervous system in all species. Furthermore, there is increasing evidence that environmental factors can modulate the composition and function of lipid rafts and influence neurodevelopmental processes. Understanding the intricate interplay between lipid rafts and neurodevelopment not only sheds light on the fundamental mechanisms governing brain development but also has implications for therapeutic strategies aimed at cultivating neuronal networks and addressing neurodevelopmental disorders.

The aim of this study was to determine the effects of altered ganglioside composition on the expression of Cx37, Cx40, Cx43, Cx45, and Panx1 in different kidney regions of St8sia1 gene knockout mice (St8sia1 KO) lacking the GD3 synthase enzyme. Experiments were performed in twelve male 6-month-old mice: four wild-type (C57BL/6-type, WT) and eight St8sia1 KO mice. After euthanasia, kidney tissue was harvested, embedded in paraffin wax, and processed for immunohistochemistry. The expression of connexins and Panx1 was determined in different regions of the kidney: cortex (CTX.), outer stripe of outer medulla (O.S.), inner stripe of outer medulla (IN.S.), and inner medulla (IN.MED.). We determined significantly lower expression of Cx37, Cx40, Cx45, and Panx1 in different parts of the kidneys of St8sia1 KO mice compared with WT. The most consistent decrease was found in the O.S. where all markers (Cx 37, 40, 45 and Panx1) were disrupted in St8si1 KO mice. In the CTX. region, we observed decrease in the expression of Cx37, Cx45, and Panx1, while reduced expression of Cx37 and Panx1 was more specific to IN.S. The results of the present study suggest that deficiency of GD3 synthase in St8sia1 KO mice leads to disruption of renal Cx expression, which is probably related to alteration of ganglioside composition.

The study aimed to determine whether the exposure to chronic stress and/or performance of gonadectomy might lead to disturbance in the expression of connexin (Cx) 37, 40 and 43 in the spinal cord (SC), as a potential explanation for sex differences in stress-related chronic pain conditions. After the rats were sham-operated or gonadectomized, three 10-day sessions of sham or chronic stress were applied. Immunohistochemistry and transmission electron microscopy (TEM) were used to examine Cx localization and expression in the SC. The gonadectomy resulted in an increase of Cx37 expression in the dorsal horn (DH) of the female rats, but chronic stress suppressed the effects of castration. In male rats, only the combined effects of castration and chronic stress increased Cx37 expression. The influence of chronic stress on the DH Cx40 expression was inversely evident after the castration: increased in the ovariectomized female rats, while decreased in the orchidectomized male rats. We did not find any effect of chronic stress and castration, alone or together, on Cx43 expression in the DH, but the percentage of Cx43 overlapping the astrocyte marker glial fibrillary acidic protein (gfap) increased in the male stressed group after the castration. In conclusion, the association of the chronic stress with sex hormone depletion results in disturbances of the SC Cx expression and might be a possible mechanism of disturbed pain perception after chronic stress exposure.

Introduction: Clance Impostor Phenomenon Scale (CIPS) is the most common and psychometrically sound instrument used to measure the impostor phenomenon. The aim of this study was to translate and make a cultural adaptation of the CIPS from English into Croatian. Materials and Methods: The translation process included two independent forward translations, combination of the forward translations into one single translation, back-translation, back-translation review, pre-piloting and drafting of the final translation after several revisions and minor adjustments by a professional reviewer. Results: We noticed no semantic differences when comparing the original and the back-translated versions of the CIPS. Thus, the final translation was only slightly changed in comparison with the first version. Conclusions: The version of the CIPS which was translated and culturally adapted into Croatian represents a reliable translation ready to be used in Croatia and Bosnia and Herzegovina.