Istanbul Arel University

Polycyclic aromatic hydrocarbons (PAHs) were assessed in surface water and sediments of the Nilüfer Stream, Bursa, Türkiye, to characterize their distribution, sources, water-sediment interactions, and associated ecological and human health risks. Samples collected from seven sites (S1-S7) revealed that the dissolved- and particulate-phase PAH concentrations in the waters ranged from 2.3 to 1118.5 μg/L and 0.3 to 422.0 μg/L, respectively, while sediments contained 32.2-836.6 ng/g dry weight. Upstream sites (S1-S2) exhibited minimal contamination, whereas downstream locations (S3-S7) reflected increasing PAH loads influenced by mixed urban, industrial, and agricultural pressures. Ring-distribution profiles showed LMW dominance in the dissolved phase and stronger MMW-HMW enrichment in particulate phase and sediments, while diagnostic ratios indicated predominantly pyrogenic inputs, particularly traffic emissions and biomass/coal combustion. Principal Component Analysis (PCA) further supported these findings, with PC1 capturing the majority of variance across dissolved- and particulate phases, and sediment as a unified pyrogenic factor, and PC2 distinguishing high-temperature industrial combustion from medium-temperature domestic heating, especially in downstream segments. Ecological risk indices (M-ERM-Q, M-PEL-Q, TEQCARC, MEQ) indicated low-to-moderate potential adverse effects, mainly in sediments. Water-sediment partitioning suggested that sediments act as long-term sinks modulated by organic carbon and hydrodynamics. Incremental Lifetime Cancer Risk (ILCR) values indicated negligible risk at S1-S2 but moderate cancer risk at S3-S7 for adults and children through ingestion and inhalation. Overall, the study provides a comprehensive spatial-temporal evaluation of PAH behavior in a mixed land-use watershed and integrates source-diagnostic and risk-based evidence to support targeted mitigation strategies in urban-industrial river systems.

Ischemia-reperfusion injury is a well-recognized challenge in reconstructive flap surgery, often leading to partial or total tissue necrosis. In this experimental study, we aimed to evaluate the protective effects of lutein-a non-provitamin A carotenoid known for its antioxidant and anti-inflammatory actions-against ischemia-reperfusion -induced damage in a rat epigastric flap model.

Sixteen Sprague-Dawley rats were randomized to receive either intraperitoneal lutein (0.5 mg/kg) or saline prior to inducing 10 h of ischemia. Flap viability was assessed macroscopically on postoperative day 10, and biochemical and histopathological analyses were conducted to explore underlying mechanisms.

Compared to controls, lutein-treated animals demonstrated significantly larger flap survival areas (21.18 ± 0.88 cm² vs. 8.42 ± 1.15 cm², p < 0.05), lower malondialdehyde levels (p < 0.01) and myeloperoxidase levels (p < 0.05), and higher glutathione (p < 0.05) and nitric oxide concentrations (p < 0.01), suggesting reduced oxidative stress and improved vascular function. Histological examination revealed less necrosis, edema, and neutrophil infiltration in the Lutein group, alongside enhanced fibroblast activity, collagen deposition, and neovascularization. Additionally, increased epidermal thickness and a notable rise in lymphocyte infiltration indicated the potential modulation of the adaptive immune response during repair.

Taken together, our findings suggest that lutein exerts a multifaceted protective effect on ischemic flap tissue and may serve as a useful adjunct in reconstructive surgery, particularly in settings with high risk of ischemia-reperfusion injury. Given its safety and supplement status, these preclinical findings support further exploration in human studies.

This study investigated the relationship between thyroid function and key perinatal factors, including mode of delivery, gestational age, and clinical condition, by comparing 152 neonates hospitalized in the neonatal intensive care unit (NICU) with 50 healthy newborns. Thyroid function tests (capillary thyroid-stimulating hormone (cTSH), venous TSH (vTSH), and free T4) were evaluated according to gestational age, delivery mode, and inferred exposure to povidone-iodine used for cesarean skin preparation. Serum free T4 concentrations were significantly lower in preterm and NICU infants compared with term controls (p = 0.007), while cTSH and vTSH levels were not significantly different. Among NICU infants, those delivered by cesarean section had lower free T4 levels than those born vaginally (p = 0.039), and free T4 was particularly reduced in infants with sepsis (p = 0.022). A moderate correlation between cTSH and vTSH was observed (ρ = 0.50, p < 0.001). These findings indicate that lower free T4 levels in preterm and clinically ill neonates likely represent transient, adaptive responses rather than permanent hypothyroidism, and that differences by delivery mode may reflect a combination of perinatal factors and inferred iodine exposure.