In vitro study on the alterations of brain tubulin structure and assembly affected by magnetite nanoparticles.

In recent decades, considerable efforts have been made to understand the mechanism of memory, cognition, and relevant neurodegenerative diseases in the human brain. Several studies have shown the importance of microtubule proteins in the memory mechanism and memory dysfunction. Microtubules possess dynamicity, which is essential for functions of neuronal networks. Microtubule-associated proteins, i.e., tau, play vital roles in microtubule stability. On the other hand, the ferromagnetic mineral magnetite (Fe(3)O(4)) has been detected in the normal human brain, and elevated levels of magnetite are also observed in the brains of Alzheimer's disease patients. Therefore, we propose that a relationship between microtubule organization in axons and brain magnetite nanoparticles is possible. In this study we found alterations of microtubule polymerization in the presence of increasing concentrations of magnetite through transmission electron microscopy images and a turbidimetry method. Structural changes of microtubule and tau protein, as an essential microtubule-associated protein for tubulin assembly, were detected via circular dichroism spectroscopy, intrinsic fluorescence, and 8-anilino-1-naphthalenesulfonic acid fluorometry. We predicted three possible binding sites on tau protein and one possible binding site on tubulin dimer for magnetite nanoparticles. Magnetite also causes the morphology of PC12 cells to change abnormally and cell viability to decrease. Finally, we suggest that magnetite changes microtubule dynamics and polymerization through two paths: (1) changing the secondary and tertiary structure of tubulin and (2) binding to either tubulin dimer or tau protein and preventing tau-tubulin interaction.

Etiological approach of chylothorax in Babol, northern Iran.

BACKGROUND: Chylothorax results from leakage of lymph in the pleural cavity because of thoracic duct injury which is associated with severe metabolic disorders. The aim of this study was to evaluate the rate of chylothorax and its causes among hospitalized patients in Shahid Beheshti Hospital of Babol city, North of Iran. METHODS: In this cross-sectional study, all patients with chylothorax admitted to the surgery department of Shahid Beheshti Hospital during 2002-2015 were included. Information including gender, age, duration of symptoms, laboratory findings, causes of disease and the type of treatment were extracted from the patients' records. RESULTS: Of the 42 patients, 27 (64.3%) were men and 15 (35.7%) were women. The mean age of the study population was 51.03±16.95. The most common clinical symptoms were dyspnea (66.7%) and dyspnea with cough (21.4%), respectively. In all patients, the pleural fluid triglyceride level was greater than 110 mg/dl, whereas the presence of lymphatic in pleural fluid was eventful in 18 (42.8%) patients. The causes of the disease were traumatic (54.8%), non-traumatic (38.1%) and unknown (7.1%), which were not significantly correlated with gender. Nineteen (45.2%) patients were operated, 16 (38.1%) patients received supportive therapy, and 7 (16.7%) patients had the treatment of the underlying conditions and then supportive therapy. CONCLUSION: According to the results, trauma was the most common cause of chylothorax. Therefore, identification and control of the traumatic factors seem to be the steps to prevent and reduce the chylothorax incidence and its complications.

Safranal as a novel anti-tubulin binding agent with potential use in cancer therapy: An in vitro study.

Safranal, a component of saffron, indicates anti-tumor activities; however, the precise mechanism of this effect has remained elusive. In this study we investigated tubulin assembly and structure in the presence of safranal to open the new horizons about the potential of safranal as an anti-tumor agent via microtubule disfunction. Anti-microtubule activity of safranal was evaluated by turbidimetric method and transmission electron microscopy (TEM). Safranal (0.1-70µM) was incubated with tubulin (5µM) and tubulin structural changes was surveyed using fluorometry. Tubulin binding site with safranal was estimated by molecular docking. Microtubule polymerization decreased significantly in the presence of safranal, regardless of its concentration and the IC50 value was obtained 72.19µM. Safranal was situated between α and ß tubulin closer to α-tubulin and hydrogen bond with Gly 142 and hydrophobic interactions played critical roles for safranal molecule stabilization in binding site. It seems that decline of tubulin assembly could result from tubulin structural changes through safranal bindings between alpha and beta tubulin with ΔG(0) of -5.63kcal/mol. Safranal can be taken into account as an anticancer agent; however, in vivo experiments are required to confirm this conclusion.