Comparison of growth factor and cytokine expression in patients with degenerated disc disease and herniated nucleus pulposus

Objectives

This study was conducted to investigate the expression of cytokines and growth factors in disc specimens obtained from patients with herniated nucleus pulposus (HNP) and degenerated disc disease (DDD).

Design and methods

MRI and Western blot analyses were performed to evaluate the levels of disc degeneration and the expression levels of cytokines and growth factors.

Results

The levels of TNF-α and IL-8 were significantly greater in the DDD group than in the HNP group, but no statistical differences were observed in the expression of IL-1β, IL-6 and IL-12 between the HNP and DDD groups. In addition, the expression of TGF β, VEGF and NGF was significantly higher in the DDD group than in the HNP group.

Conclusion

The greater levels of cytokine and growth factor expression in the DDD group than in the HNP explain why discogenic patients usually have more severe back pain than patients with herniated discs.     

Biophysical study of bioactive-substance conformation and interaction with drugs in solution

The interaction of salicylic acid (S.A), salicylamide (S.M) with nucleic acid base derivatives such as 9-ethyl adenine (A), 1-cyclohexyl uracil (U), 2′, 3′-benzylidine-5′ trityl-cytidine (C), guanosine-2′, 3′, 5′-isobutylate (G) has been spectroscopically investigated to determine the binding mechanism. NMR, and IR spectra were measured in nonpolar solvents. The association constant K of the formation of complex was calculated from the IR spectra. Compounds S.A and a form a 1∶1 or 1∶2 cyclic hydrogen-bonded complex depending on the sample concentration. Compounds S.A and U form a 1∶1 or 1∶2 hydrogen-bonded complex on the sample concentration. Compounds S.A and C form a 2∶1 hydrogen-bonded complex at low concentration (0.0016M). Compound S.A binds compound G, but its binding does not completely break the self-association of compound G. Compound S.M binds compounds A,U,C,G very weakly.     

2,3,7,8-TCDD neurotoxicity in neuroblastoma cells is caused by increased oxidative stress, intracellular calcium levels, and tau phosphorylation

One of the most notorious environmental toxicants, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), easily accumulates in the environment and most organisms, including humans, because of its high lipophilicity and resistance to degradation. TCDD exposure causes a variety of adverse health effects in humans including immunotoxicity, hepatotoxicity, neurotoxicity, and carcinogenesis. For the most part, studies regarding the adverse effects of TCDD on the central nervous system (CNS) have been limited to neurodevelopmental processes. In this study, we investigated the neurotoxicity of TCDD in neuronal cells using a neuroblastoma cell line (clone N2a) and explored the possible mechanisms of action. MTT and Comet assays were conducted to determine if TCDD is cytotoxic and if it causes DNA damage, respectively. The results of these assays revealed that treatment with 100, 300, 500 and 1000 nM TCDD decreased the viability of N2a cells and increased DNA damage in a dose-dependent manner compared to controls. Additionally, a malondialdehyde (MDA) assay was performed to determine if TCDD induces lipid peroxidation. The results of this assay revealed that 100, 300 and 500 nM TCDD induced lipid peroxidation in a dose-dependent manner. Finally, TCDD neurotoxicity (300 nM or higher) in N2a cells was accompanied by elevated intracellular calcium levels. These increased calcium levels increased the phosphorylation of tau via up-regulation of phospho-glycogen synthase kinase-3beta (GSK-3beta). Taken together, these results indicate that TCDD exposure induces neurotoxicity in N2a cells by increasing DNA damage, oxidative stress and intracellular calcium levels. The TCDD-mediated increase of tau phosphorylation in particular indicates an important role for tau hyperphosphorylation in TCDD-induced neurotoxicity.     

Skin irritation and histopathologic alterations in rats exposed to lightstick contents,UV radiation and seawater

Lightsticks are fishing gadgets that provide fluorescent lighting when two organic solutions are mixed. In NE Brazil, low-income coastal residents ignore their conventional use and collect lightsticks stranded on beaches. The lightstick solution is then used for various purposes, including direct human skin exposure. We assessed the reactions and possible cell damages on the skin of Wistar rats. Animals were exposed to lightstick contents, UV radiation and/or seawater. Lightstick exposure led to erythemas, oedemas and vesicles. Histopathologic alterations included proliferation of the epidermis and inflammatory infiltrates. In spite of the short time of experimentation (4 days), the rats exposed to the lightstick content alone and together with UV radiation and/or seawater provided evidence of irritation/alteration reactions that may evolve into skin cancer. Our results demonstrated a few of the potential problems associated with lightstick dumping into the ocean and highlight the need for further investigations about this new type of marine pollutant.     

Enhancement of dielectric performance of encapsulation in barium titanate oxide using size-controlled reduced graphene oxide

Ferroelectric barium titanate (BTO) powder particles were encapsulated by three different sizes of reduced graphene oxide (rGO) platelets. The size of the graphene oxide (GO) platelets is controlled by varying the horn type ultrasonic times, i.e. 0, 30, and 60 min, respectively, and they are reduced with hydrazine to obtain rGO-encapsulated BTO (rGO@BTO) film. The rGO@BTO film exhibits an increase in the dielectric characteristics due to the interfacial polarization. These improved characteristics include a dielectric constant of 194 (a large increment of 111%), along with the dielectric loss of 0.053 (a slight increment of 13%) at 1 kHz, compared to the pure BTO dielectric film. The improvement in the dielectric constant of the rGO@BTO is attributed to the encapsulation degree between the rGO platelets and BTO powder particles, which results in the interfacial polarization and micro-capacitor effect in a dielectric film, and also contributes to a low dielectric loss. Therefore, a suitable size of rGO platelets for encapsulation is essential for high-dielectric performance.

The controlled graphene size affected the dielectric performance of graphene encapsulated BaTiO₃ (rGO@BTO) particles. The dielectric performance increased by 33% higher than the dielectric constant after 1 h, while maintaining the low dielectric loss.     

Dietary mineral and trace element intake and squamous cell carcinoma of the esophagus in a Chinese population

Few studies have been conducted in low-selenium areas of China to assess the relationships between dietary intake of selenium and zinc and the risk of squamous cell carcinoma of the esophagus (SCCE). We studied dietary mineral and trace element intake and risk of SCCE in a population- based, case-control study in Taixing, China, in 2000. A total of 218 SCCE patients and 415 population healthy controls were interviewed using a standard dietary and health questionnaire. The median and quartiles were calculated to represent the average level and distribution of selected dietary minerals and trace elements estimated by the Chinese Standard Tables of Food Composition. The adjusted odds ratios (ORs) comparing the highest with the lowest quartiles were 0.30 (95% confidence intervals, CIs = 0.13-0.67) for selenium intake and 0.28 (95% CI = 0.11-0.70) for zinc intake with obvious dose-dependent patterns (P values for trend = 0.01). The adjusted OR for the combined effect of selenium and zinc intake was 0.53 (95% CI = 0.29-0.96) after controlling for potential confounding factors, including age, gender, educational level, body mass index, and total energy intake. Our results suggested that the potential joint effect of zinc and selenium might contribute to SCCE risk. Increased dietary intake of selenium and zinc may decrease the risk of SCCE in a low-selenium area of China.