Radiation-induced brain injury causes significant neurotoxicity and cognitive dysfunction in patients undergoing radiotherapy for brain tumors. This study aimed to evaluate the neuroprotective effects Show more
Radiation-induced brain injury causes significant neurotoxicity and cognitive dysfunction in patients undergoing radiotherapy for brain tumors. This study aimed to evaluate the neuroprotective effects of intranasal ketamine on radiation-induced brain injury, specifically focusing on its modulation of perineuronal networks (PNNs), extracellular matrix components, and neuroinflammation. Eighteen male New Zealand White Rabbits were divided into three groups: normal controls, irradiation (IR) with saline (IR + saline), and IR with ketamine (IR + ketamine). Whole-brain IR (20 Gy) was applied to the IR groups, and ketamine (2 mg/kg/day) was administered intranasally for 15 days. Biochemical markers, including malondialdehyde (MDA), tumor necrosis factor-alpha (TNF-α), brain-derived neurotrophic factor (BDNF), ADAMTS4, and syndecan-1 levels, were measured. Histopathological analysis of hippocampal and cerebellar regions assessed neuronal survival and astrogliosis. Magnetic resonance spectroscopy (MRS) evaluated lactate and Ketamine administration significantly reduced oxidative stress (MDA) and inflammatory markers (TNF-α) while restoring BDNF levels compared to the IR + saline group. ADAMTS4 and syndecan-1 levels were reduced, changes consistent with PNN-associated extracellular matrix dynamics, but without direct confirmation by core PNN markers such as aggrecan or WFA staining. Histopathology showed increased neuronal survival and decreased reactive astrogliosis in ketamine-treated groups. Intranasal ketamine demonstrates significant neuroprotective effects in a radiation-induced brain injury model by reducing oxidative stress and inflammation, modulating extracellular matrix components, and preserving neuronal integrity. These findings highlight ketamine's potential as a therapeutic agent, although direct PNN markers and broader cytokine panels were not assessed. Overall, ketamine showed neuroprotective effects across biochemical, histological, and MRS-supported metabolic readouts. Show less
Previous studies have pointed out a link between vitamin D status and metabolic traits, however, consistent evidence has not been provided yet. This cross-sectional study has used a nutrigenetic appro Show more
Previous studies have pointed out a link between vitamin D status and metabolic traits, however, consistent evidence has not been provided yet. This cross-sectional study has used a nutrigenetic approach to investigate the interaction between metabolic-genetic risk score (GRS) and dietary intake on serum 25-hydroxyvitamin D [25(OH)D] concentrations in 396 unrelated Turkish adults, aged 24-50 years. Serum 25(OH)D concentration was significantly lower in those with a metabolic-GRS ≥ 1 risk allele than those with a metabolic-GRS < 1 risk allele ( Show less
Cytokines are major mediators of COVID-19 pathogenesis and several of them are already being regarded as predictive markers for the clinical course and outcome of COVID-19 cases. A major pitfall of ma Show more
Cytokines are major mediators of COVID-19 pathogenesis and several of them are already being regarded as predictive markers for the clinical course and outcome of COVID-19 cases. A major pitfall of many COVID-19 cytokine studies is the lack of a benchmark sampling timing. Since cytokines and their relative change during an infectious disease course is quite dynamic, we evaluated the predictive value of serially measured cytokines for COVID-19 cases. In this single-center, prospective study, a broad spectrum of cytokines were determined by multiplex ELISA assay in samples collected at admission and at the third day of hospitalization. Appropriateness of cytokine levels in predicting mortality were assessed by receiver-operating characteristic (ROC) analyses for both sampling times in paralel to conventional biomarkers. At both sampling points, higher levels of IL-6, IL-7, IL-10, IL-15, IL-27 IP-10, MCP-1, and GCSF were found to be more predictive for mortality (p<0.05). Some of these cytokines, such as IL-6, IL-10, IL-7 and GCSF, had higher sensitivity and specificity in predicting mortality. AUC values of IL-6, IL-10, IL-7 and GCSF were 0.85 (0.65 to 0.92), 0.88 (0.73 to 0.96), 0.80 (0.63 to 0.91) and 0.86 (0.70 to 0.95), respectively at hospital admission. Compared to hospital admission, on the 3rd day of hospitalization serum levels of IL-6 and, IL-10 decreased significantly in the survivor group, unlike the non-survivor group (IL-6, p = 0.015, and IL-10, p = 0.016). Our study results suggest that single-sample-based cytokine analyzes can be misleading and that cytokine levels measured serially at different sampling times provide a more precise and accurate estimate for the outcome of COVID-19 patients. Show less