Surface integrity and corrosion performance of biomedical magnesium-calcium alloy processed by hybrid dry cutting-finish burnishing.

Biodegradable magnesium-calcium (MgCa) alloy is a very attractive orthopedic biomaterial compared to permanent metallic alloys. However, the critical issue is that MgCa alloy corrodes too fast in the human organism. Compared to dry cutting, the synergistic dry cutting-finish burnishing can significantly improve corrosion performance of MgCa0.8 (wt%) alloy by producing a superior surface integrity including good surface finish, high compressive hook-shaped residual stress profile, extended strain hardening in subsurface, and little change of grain size. A FEA model was developed to understand the plastic deformation of MgCa materials during burnishing process. The measured polarization curves, surface micrographs, and element distributions of the corroded surfaces by burnishing show an increasing and uniform corrosion resistance to simulated body fluid.

DNA Methylation and microRNA patterns are in association with the expression of BRCA1 in ovarian cancer.

Ovarian cancer is the sixth most prevalent cancer in women and is considered the most lethal gynecological malignancy. It can be inherited as a familial disease but also has a strong spontaneous occurrence. Although the disease is associated with genome instability brought on by genetics and environmental factors there is evidence that mutations in the gene encoding for the breast cancer type 1 susceptibility protein (BRCA1) or its down-regulation are involved in its development. Down-regulation of BRCA1 expression by hypermethylation of its promoter may account for some cases of ovarian cancer but this does not explain the cause of the majority of the disease. This review explores the role of BRCA1 promoter hypermethylation and micro-RNAs (miRNA) involved in the regulation of BRCA1 and their role in ovarian cancer development as well as some of the exciting discoveries which could lead to targeting miRNA with a view to restoring BRCA1 expression in diseased tissues.

Morphometric and hormonal study of the effect of utrica diocia extract on mammary glands in rats / Estudio morfométrico y hormonal del efecto de extracto de utrica diocia en glándulas mamarias en ratas

Urtica diocia is a multipurpose herb in traditional medicine. Its hydroalcoholic extract (20, 50 and 100 mg/kg) administered interaperitoneally to Wistar female rats for 21 consequent days resulted in significant increase in the number of alveoli of mammary glands in doses of 20 and 50 mg/kg. Changes in serum prolactin and alveolar diameter were not significant in comparison with control group. Also, there was an increase in serum prolactin and alveolar diameter in doses of 20 and 50 mg/kg. Utrica diocia extract has positive effects on mammary glands.

Urtica diocia es una hierba de usos múltiples en la medicina tradicional. Su extracto hidroalcohólico (20, 50 y 100 mg/kg) administrado por vía intraperitoneal en ratas hembras Wistar de 21 días resultaron en un aumento significativo en el número de alvéolos de las glándulas mamarias en dosis de 20 y 50 mg/kg. Los cambios en la prolactina sérica y el diámetro alveolar no fueron significativos en comparación con el grupo control. Además, hubo un aumento en la prolactina sérica y en el diámetro alveolar en dosis de 20 y 50 mg/kg. El extracto de Urtica diocia tiene efectos positivos sobre las glándulas mamarias.

Morphometrical analysis of the effect of nicotine administration on brain's prefrontal region in male rat / Análisis morfométrico del efecto de la administración de nicotina sobre la región prefrontal del cerebro en rata macho

Nicotine is the most important alkaloid compound in tobacco. One of the major effects of nicotine is stimulation of mesocorticolimbic system. Prefrontal cortex plays a pivotal role in personality and mental state. It is considered the main cause of addiction as it is located in mesocorticolimbic dopamine system. Twenty four male rats were divided into four groups based on nicotine administration dose (0, 0.5, 1 and 1.5 g/kg). After animals were anesthetized, their brains were fixed using transcardiac method. Tissue processing and Golgi staining were performed and the stained tissue sections were analyzed by optic microscope and Motic software. By increasing the dose, nicotine significantly decreased the number of neuronal processes. In the higher dose, nicotine caused a significant decrease and increase in the size of pericarions and dendritic spines, respectively (p<0.05). Nicotine administration can decrease the size of pericarion and number of dendritic spines in the prefrontal cortex.

La nicotina es el compuesto alcaloide más importante del tabaco. Uno de sus principales efectos es la estimulación del sistema mesocorticolímbico. La corteza prefrontal desempeña un papel fundamental en la personalidad y estado mental. Esta es considerada la principal causa de la adicción, ya que se encuentra en el sistema mesocorticolímbico dopaminérgico. Veinticuatro ratas macho fueron divididas en cuatro grupos basados en la dosis de administración de nicotina (0, 0,5, 1 y 1,5 g/kg). Luego fueron anestesiados y sus cerebros se fijaron mediante perfusión transcardíaca. Se realizó el procesamiento de tejidos y las secciones bajo tinción de Golgi fueron analizadas mediante microscopia óptica y el software Motic. Con el aumento de dosis, la nicotina redujo significativamente el número de procesos neuronales. En la dosis más alta, la nicotina causó una disminución y aumento significativo en el tamaño de pericarion y espinas dendríticas, respectivamente (p<0,05). La administración de nicotina puede disminuir el tamaño del pericarion y el número de espinas dendríticas en la corteza prefrontal.

The effect of walnut on the weight, blood glucose and sex hormones of diabetic male rats / Efecto del nogal sobre el peso, glucosa en la sangre y hormonas sexuales de ratas macho diabéticas

Diabetes leads to reproductive dysfunctions by producing free radicals. It seems that using walnut can be effective in the damage induced by diabetes. The aim of the present study was to evaluate the effects of walnut consumption on sex hormones in diabetic Wistar male rats induced by STZ (streptozotocin). Diabetes animals were induced by STZ (60 mg/kg). Rats were randomly divided into 5 groups (n=6), including normal diet and healthy (Sham), Diabetic by normal diet (control) and diabetic by 6, 9 and 12% walnut in their diet (experimental groups), and were examined for 6 weeks. Body weight, blood glucose (3 times), and sex hormones (testosterone, FSH and LH) were measured. Overall, in terms of the mean index, there was a significant difference in the percentage of weight changes between the groups (p<0.001). Blood glucose (3 times) significantly increased in experimental and control groups in comparison with sham group (p<0.001). FSH concentration significantly decreased in control group (p<0.05) and testosterone hormone decreased in experimental and control groups compared to sham group (p<0.05). Oral administration of walnut seems to prevent severe weight loss in the experimental models of diabetic rats and exerts appropriate and useful changes in blood glucose level as well as positive effects on the secretion of sex hormones.

La diabetes conduce a disfunciones reproductivas mediante la producción de radicales libres. Parece que el uso del nogal puede ser eficaz para contrarestar el daño inducido por la diabetes. El objetivo fue evaluar los efectos del consumo de nueces sobre las hormonas sexuales en ratas Wistar macho diabéticas, inducidas por estreptozotocina (STZ). La diabetes en los animales fue inducida por STZ (60 mg/kg). Los animales fueron divididos aleatoriamente en 5 grupos (n= 6 ): saludable con dieta normal (Sham), diabéticos con dieta normal (control) y diabéticos con consumo de nogal en 6, 9 y 12% en su dieta (grupos experimentales), quienes se examinaron durante 6 semanas, donde se midieron el peso corporal, glucosa en la sangre (3 veces) y hormonas sexuales (testosterona , FSH y LH). En general, en términos del índice promedio, hubo una diferencia significativa en el porcentaje de cambios de peso entre los grupos (p<0,001). La glucosa en sangre aumentó significativamente en los grupos experimentales y de control en comparación con el grupo Sham (p<0,001). La concentración de FSH se redujo significativamente en el grupo control (p<0,05); la testosterona disminuyó en los grupos experimentales y control en comparación con el grupo sham (p<0,05). La administración oral de nogal parece prevenir la pérdida severa de peso en los modelos experimentales de ratas diabéticas y ejerce cambios apropiados y útiles en el nivel de glucosa en la sangre, así como efectos positivos sobre la secreción de hormonas sexuales.

Protective effect of curcumin against nicotine-induced damage on reproductive parameters in male mice / Efecto protector de la curcumina contra el daño inducido por la nicotina sobre los parámetros reproductivos en ratones machos

Nicotine consumption can decrease fertility drive in males through inducing oxidative stress and DNA damage. The color of turmeric is because of a substance called curcumin for which some anti-oxidative and anti-inflammatory properties have been identified. In this study, various doses of curcumin (10, 30 and 60 mg/kg) and curcumin plus nicotine (10, 30 and 60 mg/kg) were administered intraperitoneally to male mice for 28 consequent days and reproductive parameters were determined. The results indicated that nicotine administration (0.5 mg/kg) significantly decreased testosterone level, count and motility of sperms, and testis weight compared to control group. However, increasing the dose of curcumin significantly increased reproductive indices in most of the groups. Thus, it seems that curcumin inhibits nicotine-induced adverse effects on reproductive parameters.

El consumo de nicotina puede disminuir la fertilidad en los hombres mediante la inducción de estrés oxidativo y daño del ADN. El color de la cúrcuma se debe a una sustancia llamada curcumina en la cual se han identificado algunas propiedades anti-oxidantes y anti-inflamatorias. En este estudio se administraron diferentes dosis de curcumina (10, 30 y 60 mg/kg) y de curcumina más nicotina (10, 30 y 60 mg/kg) por vía intraperitoneal a ratones machos durante 28 días consecutivos y se determinaron los parámetros reproductivos. La administración de nicotina (0,5 mg/kg) disminuyó significativamente el nivel de testosterona, el número y motilidad de los espermatozoides, y peso de los testículos en comparación con el grupo control. Sin embargo, el incremento de la dosis de curcumina aumentó significativamente los índices reproductivos en la mayoría de los grupos. Este estudio sugiere que la curcumina inhibe los efectos adversos inducidos por la nicotina sobre los parámetros reproductivos.

The effects of aqueous extract of Boswellia Serrata on hippocampal region CA1 and learning deficit in kindled rats.

Temporal lobe epilepsy (TLE) is a disorder of the central nervous system in which hippocampus is mostly involved and causes memory impairment. Kindling is a model of inducing epilepsy which is created through pentylenetetrazol (PTZ) administration. This study examines the role of the aqueous extract of Boswellia on the learning and development of brain (formation of dendritic branches and axons) of the PTZ-induced kindled rats. The study is conducted on sixty-four male rats divided into 8 groups. Kindling seizures are induced by three injections of 25 mg/kg of PTZ every 15 min. The aqueous extracts (0, 0.1, 0.5, 1 g/kg, i.p) are administrated to all animals for three consecutive days. Passive avoidance learning of animals is examined using shuttle box apparatus and step-through latency (STL) method. Rats are anesthetized and their brains are fixed by transcardial perfusion method and are analyzed by morphometric methods after applying Golgi and Cresyl violet staining methods. PTZ-induced kindling indicates a significant decrease in the number of pyramidal neurons and dendritic spines in hippocampal region cornu ammonis (CA1). The STL of the kindled rats is significantly reduced compared with control ones. Also, Boswellia extract dramatically increased the number of neuronal processes in CA1 region and improves passive-avoidance learning ability in both control and PTZ-kindled animals in 1 g/kg dose administration of Boswellia extract, especially at high doses can eliminate adverse effects of seizures on cognitive function in hippocampal area CA1 in rats.

The apoptotic effects of sirtuin1 inhibitor on the MCF-7 and MRC-5 cell lines.

Sirtuin1 (SIRT1) is an enzyme that deacetylates histones and several nonhistone proteins including p53 during stress and plays an important role in the survival of tumor cells. Hereby, this study describes the potency of salermide as a SIRT1 inhibitor to induce apoptosis in the MCF-7 and MRC-5 cell lines. MCF7 and MRC-5 cell lines were cultured in RPMI-1640 and treated with or without salermide at concentration of 80.56 µmol/L, based on the half-maximal inhibitory concentration (IC50) index at different times (24, 48 and72 h). The IC50 value was established for the salermide in MCF-7. The percentage of apoptotic cells was measured by flow cytometry. Real-time quantitative RT-PCR was performed to estimate the mRNA expression of sirtuin1 in MCF-7 and MRC-5 with salermide at different times. ELISA and Bradford protein techniques were used to detect endogenous levels of total and acetylated p53 protein generated in MCF-7 and MRC-5 cells. Our findings indicated that salermide can induce apoptosis in MCF-7 significantly more effective than MRC-5 cells. We showed that the expression of SIRT1 was dramatically down-regulated by increasing the time of salermide treatment in MCF-7 but not MRC-5 and that the acetylated and total p53 protein levels were increased more in MCF-7 than MRC-5. Salermide, by decreasing the expression of sirtuin1 gene, can induce acetylation of P53 protein and consequently induce significant cell death in MCF-7 that was well tolerated in MRC-5.

Surface integrity of biodegradable Magnesium-Calcium orthopedic implant by burnishing.

Magnesium-Calcium (MgCa) alloy as an emerging biodegradable implant material has received considerable attention in orthopedic fixation applications. The biodegradable MgCa alloys avoid stress shielding and secondary surgery inherent with permanent metallic implant materials. They also provide sufficient mechanical strength in load carrying applications as opposed to biopolymers. However, the key issue facing a biodegradable MgCa implant is the fast corrosion in the human body environment. The ability to adjust the degradation rate of MgCa alloys is critical in the successful development of biodegradable orthopedic materials. Burnishing as a low plastic deformation process is a promising technique to tune surface integrity of MgCa implant surface for biodegradation control. However, the poor ductility of MgCa alloys imposes a great challenge for burnishing. This study focuses on the basic understanding of surface mechanical behavior of burnished biodegradable MgCa0.8 (wt%) alloy. The effects of burnishing parameters, i.e., pressure, feed, speed, number of path, and burnishing pattern on surface integrity factors such as surface topography, roughness, microhardness, microstructure, and residual stresses are investigated. The burnished surfaces are shinier and smoother than the as-machined ones. The MgCa alloy can be safely burnished at suitable burnishing conditions since no cracks are produced at the surface and in the subsurface. The microstructure including grain size does not show a noticeable change after burnishing. The machined surfaces are harder than the burnished ones down to the deep subsurface (∼200 µm) as opposed to the shallow hardened depth (∼50 µm) in cutting. Residual stresses are highly compressive especially at low burnishing pressure.