Substituent-controlled construction of A4B2-hexaphyrins and A3B-porphyrins: a mechanistic evaluation.

A substituent-dependent construction of novel A3B-porphyrins along with A4B2-hexaphyrins was realized by the reactions of N-tosylimines and meso-aryl-substituted tripyrranes in the presence of Cu(OTf)2 as the catalyst. The reaction mechanism of the presented method was studied on model reactions by electrospray-ionization time-of-flight (HRESI-TOF) mass spectral analysis in a timely manner. The analytical results indicated that the observed azafulvene-ended di- and tripyrrolic intermediates are responsible for the formation of porphyrinogen and hexaphyrinogen forms.

Effects of gadodiamide and gadoteric acid on lung tissue: A comparative study.

We set out to investigate the effects of gadodiamide and gadoteric acid, used for magnetic resonance imaging, on the lungs. In this study, 32 male Sprague Dawley rats were used. These were allocated into four groups; The first group (control) was untreated. The second group received isotonic saline on the first and fourth days of the week for 5 weeks. Following the same schedule, the third and fourth groups received a total of 2 mg/kg gadodiamide and gadoteric acid, respectively, in place of saline. The alveolar Wall thickness was evaluated. Gadodiamide and gadoteric acid significantly increased the numbers of collagen-3 and caspase-3 positive cells in the lung tissue (p < 0.05). In addition, these two substances increased the alveolar Wall thickness (p < 0.05). Furthermore, they increased the levels of malondialdehyde and glutathione (p < 0.05). This study demonstrates that both linear and macrocyclic contrast agents are toxic for the lungs in rats.

Effect of the prenatal electromagnetic field exposure on cochlear nucleus neurons and oligodendrocytes in rats.

Electromagnetic radiation from elecromagnetic field (EMF) sources has been an important health concern for a long time. The vast majority of this exposure is due to the widespread use of mobile phones, an important source of the EMF. The EMF generated by mobile phones may have adverse effects on the various biological structures that regulate the body system and function. In this study, it was aimed to evaluate histopathologically the effects of 900-megahertz (MHz) EMF application in the prenatal period on the development of the ventral cochlear nucleus, which is the first place of hearing in the brainstem, at various time points of the postnatal period in rats. In the study, Sprague-Dawley pregnant rats were divided randomly into two groups as the control group and the EMF group. The rats in the EMF group were exposed to a 900-MHz EMF every day until birth, while no EMF was applied to the rats in the control group. Auditory brainstem responses of both groups were recorded on the postnatal 13th day, the day the hearing starts. Newborn rats were sacrificed by anesthesia on days 7, 10, 15, and 30. Contrary to the control group, structural damage in cochlear nuclear neurons and oligodendrocyte cell structures and increased caspase-3 activity were observed in the postnatal period in the EMF groups. However, no significant difference was observed between the groups in terms of structural damage and caspase-3 activity at different stages of the postnatal period when cochlear nucleus development was observed. According to ABS, there was no significant difference between the average latency of waves in both groups. In conclusion, this study shows that 900-MHz electromagnetic waves propagated from mobile phones during the prenatal period have no harmful effects on the development of the ventral cochlear nucleus of rats.

Comparison of effects of dexmedetomidine and amifostine against X-ray radiation-induced parotid damage.

Radiotherapy can be employed as a therapeutic modality alone in the early stages of cancer and is used together with other treatments such as surgery and chemotherapy in more advanced stages. However, exposure to ionizing radiation in association with radiotherapy affects several organs in the head and neck and can give rise to early and late side effects. Exposure to ionizing radiation used in radiotherapy is known to cause cell damage by leading to oxygen stress through the production of free oxygen radicals (such as superoxide radicals, hydroxyl radical, hydrogen peroxide, and singlet oxygen), depending on the total radiation dosage, the fractionation rate, radiosensitivity, and linear energy transfer. The purpose of the present study was to determine the potential protective role of a powerful and highly selective α2-adrenoreceptor agonist with a broad pharmacological spectrum against salivary gland damage induced by ionizing radiation exposure. Forty Sprague-Dawley rats were divided into five groups-control, ionizing radiation, ionizing radiation + dexmedetomidine (100 µg/kg), ionizing radiation + dexmedetomidine (200 µg/kg), and ionizing radiation + amifostine (200 mg/kg). Following exposure to ionizing radiation, we observed necrosis, fibrosis, and vascular congestions in parotid gland epithelial cells. We also observed increases in malondialdehyde (MDA) and cleaved Caspase-3 levels and a decrease in glutathione (GSH). In groups receiving dexmedetomidine, we observed necrotic epithelial cells, fibrosis and vascular congestion in parotid gland tissue, a decrease in MDA levels, and an increase in GSH. Dexmedetomidine may be a promising antioxidant agent for the prevention of oxidative damage following radiation exposure.

Effects of long-term Doppler ultrasound exposure on cochlea and cochlear nucleus in prenatal period in an experimental model.

BACKGROUND: New generation Doppler ultrasonography (DUSG) application effects on cochlea and cochlear nucleus (CN) are unclear. We aimed to investigate the effects of new generation DUSG application at different frequencies in prenatal period on cochlea and CN in rats. OBJECTIVE: Twenty-four pregnant female rats were divided into three groups (n = 8). Group 1 was the control group and was not subjected to any treatment. Group 2 was determined as the USG every day (USGED) treatment group. Group 2 has received DUSG application every day from the 4th to 18th day (20 min/15 per day). Group 3 has received DUSG application as "2 days/one dose as every other day application" (USG2D1) from the 4th to 18th day (20 min/8 every other day). Twenty-four female rats were sacrificed in 21 days. Also, 24 pups were sacrificed after two days. First day after born, the cochlear activities of the right ears of all pups were examined using DPOAEs. Second day, neural tissues from CN were evaluated histopathologically and immunohistochemically. RESULTS: There was no any statistical difference between the groups in respect of histopathologically. USGED group showed mild caspase-3 positive neurons and glial cells. However, there was no significant difference between the USGED and other groups (p>.05). Similarly, the rats applied with USG2D1 had mild caspase-3 expression, but no significant difference between the USG2D1 and other groups (p>.05). Differences in DPOAE amplitudes, and therefore in cochlear activity, between the groups were revealed. The decrease in cochlear activity between the groups involved frequencies at 2, 8, 16, and 32 kHz (p<.05). CONCLUSIONS: Multiple administration of new generation DUSG to pregnant rats has not shown harmful effects on the cochlear neural tissue. High frequencies are more sensitive in cochlea to apply DUSG.

Can Dexmedetomidine Be Effective in the Protection of Radiotherapy-Induced Brain Damage in the Rat?

Approximately 7 million people are reported to be undergoing radiotherapy (RT) at any one time in the world. However, it is still not possible to prevent damage to secondary organs that are off-target. This study, therefore, investigated the potential adverse effects of RT on the brain, using cognitive, histopathological, and biochemical methods, and the counteractive effect of the α2-adrenergic receptor agonist dexmedetomidine. Thirty-two male Sprague Dawley rats aged 5-6 months were randomly allocated into four groups: untreated control, and RT, RT + dexmedetomidine-100, and RT + dexmedetomidine-200-treated groups. The passive avoidance test was applied to all groups. The RT groups received total body X-ray irradiation as a single dose of 8 Gy. The rats were sacrificed 24 h after X-ray irradiation, and following the application of the passive avoidance test. The brain tissues were subjected to histological and biochemical evaluation. No statistically significant difference was found between the control and RT groups in terms of passive avoidance outcomes and 8-hydroxy-2'- deoxyguanosine (8-OHdG) positivity. In contrast, a significant increase in tissue MDA and GSH levels and positivity for TUNEL, TNF-α, and nNOS was observed between the control and the irradiation groups (p < 0.05). A significant decrease in these values was observed in the groups receiving dexmedetomidine. Compared with the control group, gradual elevation was determined in GSH levels in the RT group, followed by the RT + dexmedetomidine-100 and RT + dexmedetomidine-200 groups. Dexmedetomidine may be beneficial in countering the adverse effects of RT in the cerebral and hippocampal regions.

The effect of white tea on serum TNF-α/NF-κB and immunohistochemical parameters in cisplatin-related renal dysfunction in female rats.

OBJECTIVE: Nephrotoxicity is the most important side effect of the antineoplastic drug cisplatin, thereby restricting its use. The aim of this study was to investigate the protective effects of white tea infusions (WT) against renal damage induced by cisplatin (CP) in rats by biochemical and histopathological means. MATERIALS AND METHODS: This study used 24 female Sprague Dawley rats at 12-14 weeks of age and weighing 250-300 g. Rats were divided into three groups: Control, CP and CP + WT groups. CP was injected 7 mg/kg i.p as a single dose/rat in the CP group. White tea was given at a dose of 0.5% (w/v) for 4 weeks. At the end of the experiment, blood urea nitrogen (BUN), creatinine, uric acid, tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and nuclear factor kappa B (NF-κB) along with caspase-3 in the kidney were evaluated in study. RESULTS: BUN, creatinine, TNF-α, NF-κB and IL-6 levels of the CP group showed a statisically significant increase in comparison to the control group. TNF-α, NF-κB and IL-6 levels showed a statistically significant decrease in the CP + WT group with respect to the CP group. Caspase-3 levels in tubular epithelial cells decreased in CP + WT group compared with CP group (p = 0.02). CONCLUSION: White tea infusions reduced significantly the nephrotoxicity of CP. The anti-nephrotoxic feature of the infusion may be attributed primarily to its anti-inflammatory and anti-apoptotic characteristics.

Effects of gadolinium-based MRI contrast agents on liver tissue.

BACKGROUND: MRI with contrast is often used clinically. However, recent studies have reported a high accumulation of gadolinium-based contrast agents (GBCAs) in kidney, liver, and spleen tissues in several mouse models. PURPOSE: To compare the effects on liver tissue of gadolinium-based MRI contrast agents in the light of biochemical and histopathological evaluation. STUDY TYPE: Institutional Review Board (IRB)-approved controlled longitudinal study. ANIMAL MODEL: In all, 32 male Sprague-Dawley rats were divided into a healthy control group subjected to no procedure (Group 1), a sham group (Group 2), a gadodiamide group (Group 3), and a gadoteric acid group (Group 4). FIELD STRENGTH/SEQUENCE: Not applicable. ASSESSMENT: Liver tissues removed at the end of the fifth week and evaluated pathologically (scored Knodell's histological activity index [HAI] method by two histopathologists) immunohistochemical (caspase-3 and biochemical tests (AST, ALT, TAS, TOS, and OSI method by Erel et al) were obtained. STATISTICAL TESTS: Differences between groups were analyzed using the nonparametric Kruskal-Wallis test followed by the Tamhane test, and one-way analysis of variance (ANOVA) followed by Turkey's HSD test. RESULTS: An increase was observed in histological activity scores in sections from rats administered gadodiamide and gadoteric acid, and in caspase-3, AST and ALT values (P < 0.05). In contrast, we determined no change in TOS (P = 0.568 and P = 0.094, respectively), TAS (P = 0.151 and P = 0.055, respectively), or OSI (P = 0.949 and P = 0.494, respectively) values. DATA CONCLUSION: These data suggest that gadodiamide and gadoteric acid trigger hepatocellular necrosis and apoptosis by causing damage in hepatocytes, although no change occurs in total antioxidant and antioxidant capacity. LEVEL OF EVIDENCE: 1 Technical Efficacy: Stage 4 J. Magn. Reson. Imaging 2018;47:1367-1374.

An efficient removal of RB5 from aqueous solution by adsorption onto nano-ZnO/Chitosan composite beads.

In this study, the removal of Reactive Black 5 (RB-5) by nano-ZnO/Chitosan composite beads (nano-ZnO/CT-CB) from aqueous solution was investigated. ZnO nanoparticles were prepared by the via the microwave-assisted combustion technique. And then nano-ZnO/Chitosan composite beads were prepared by polymerization in the presence of nano-ZnO and chitosan. Characterization of composite beads were conducted using SEM, TEM, FTIR, TGA and XRD. Several important parameters influencing the removal of RB 5 such as contact time, pH and temperature were investigated systematically by batch experiments. At optimum conditions of pH 4 and adsorbent concentration of 0.2g, dye removal efficiency was found 76%. Langmuir, Freundlich and Temkin adsorption models were used to describe adsorption isotherms and constants. The maximum adsorption capacity (qm) by Langmuir isotherm has been found to be 189.44mg/g. Isotherms have also been used to obtain the thermodynamic parameters such as free energy, enthalpy and entropy of adsorption. The positive value of the enthalpy change (32.7kJ/mol) indicated that the adsorption is an endothermic process. The obtained results showed that the tested adsorbents are efficient and alternate low-cost adsorbent for removal of dyes from aqueous media.