Kinetic alterations in rat liver microsomal cholecalciferol 25-hydroxylase associated with phenobarbital administration

The kinetics of cholecalciferol 25-hydroxylase in vitamin D-depleted rat liver microsomes, before and after phenobarbital induction, were studied. Three days of pretreatment with phenobarbital altered significantly both the apparent K_m and the V_max of the hydroxylase. Untreated vitamin D-repleted rats had lower cytochrome P-450 content and aminopyrine demethylase activity than the vitamin D-depleted animals. Phenobarbital administration reversed this nutritional effect on aminopyrine demethylase but not on cytochrome P-450 content. Furthermore, vitamin D deficiency potentiated the phenobarbital inductive effect upon microsomal protein. No inhibition of aminopyrine demethylase could be elicited in the presence of cholecalciferol or 25-hydroxycholecalciferol either prior to or after phenobarbital treatment, suggesting that these two oxidases are different entities.     

Radioprotective effect of atorvastatin against ionizing radiation-induced nephrotoxicity in mice

Purpose: Kidneys are exposed to ionizing radiation during radiotherapy in patients with abdominal malignancy. The aim of this study is to investigate the protective effect of atorvastatin (ATV) against ionizing radiation-induced nephrotoxicity in mice.

Materials and methods: Sixty male BALB/c mice were randomly divided into six groups (10 mice per group); control, irradiation (IR), IR plus ATV (10, 20 and 50?mg/kg) and only ATV (50?mg/kg). ATV groups received ATV for seven days via oral gavage before exposure to IR. Animals were exposed to 2?Gy whole body of X-ray on day 8. After exposure to IR, biochemical, histological and immunohistological assays were performed.

Results: ATV significantly decreased the level of oxidative stress biomarkers in irradiated mice in comparison with IR alone. A significant reduction in the urea and creatinine levels was observed in ATV plus IR group compared to IR alone. Tubular degeneration, glomerular atrophy, interstitial expansion and fibrosis were observed in irradiated mice. Tubular degeneration and atrophy in the kidneys of IR plus ATV group were less than IR group. In addition, pre-treated animal with ATV significantly showed reduction in caspase-3 immunoreactivity.

Conclusion: ATV has significant protective effect against radiation-induced nephrotoxicity in mice and is a promising medication for protection of patients during radiotherapy.     

High dose Allura Red,rather than the ADI dose,induces structural and behavioral changes in the medial prefrontal cortex of rats and taurine can protect it

Allura Red is a food color that can lead to neurotoxicity. Taurine is an organic compound that can act as a neuroprotectant. This study aimed to assess the effects of Allura Red with or without taurine consumption on rats’ medial Prefrontal Cortex (mPFC). The subjects were divided into six groups as follows: distilled water, taurine (200?mg/kg/day), and low (7?mg/kg/day?=?acceptable daily dose), and high (70?mg/kg/day) doses of Allura Red with or without taurine consumption for six weeks. The results of novel objects recognition and eight-arm radial maze tests indicated impairment of memory in the Allura Red groups. Subsequently, their brains were analyzed using stereological methods. Both doses of Allura Red caused an increase in working and reference memory errors during the acquisition and retention phases in comparison to the distilled water group (p?<?0.01). Additionally, the high dose of Allura Red led to a reduction in the volume of mPFC (35%) and its subdivisions, number of neurons (59%) and glial cells (46%), length of dendrites, and number of spines (mushroom and thin) per dendritic length in comparison to the distilled water group (p?<?0.05). The low dose group only showed a reduction in the number of glial cells. However, simultaneous treatment of rats with taurine plus Allura Red prevented the above-mentioned changes. The acceptable daily dose of Allura Red could bring about impairment in spatial learning and memory as well as in the number of glial cells. On the other hand, the high dose of Allura Red could impair learning, memory, and mPFC structure. Thus, taurine could act as a neuroprotectant.     

Subacute Sclerosing Panencephalitis in Children: The Archetype of Non-Vaccination

Subacute sclerosing panencephalitis (SSPE) is a late complication of measles virus infection that occurs in previously healthy children. This disease has no specific cure and is associated with a high degree of disability and mortality. In recent years, there has been an increase in its incidence in relation to a reduction in vaccination adherence, accentuated by the COVID-19 pandemic. In this article, we take stock of the current evidence on SSPE and report our personal clinical experience. We emphasise that, to date, the only effective protection strategy against this disease is vaccination against the measles virus.     

Teaching evidence-based medicine more effectively

Evidence-based Medicine (EBM) is becoming an integral component of graduate medical education competency and a requirement for grad medical education practice-based learning core competency. This study tries to compare the efficacy of conferences utilizing small-group discussions with the traditional conference method in enhancing EBM competency. The participants in this randomized controlled trial (RCT) were 170 members of the medical faculty who were divided into two groups of 86 (intervention) and 84 (control). Following the intervention, EBM competency was assessed by a written examination. statistical analysis made use of chi-square test, independent sample t-test and relative risks for univariate analysis. Mantel-Hanszel was used for bivariate analysis. Cox proportional hazard models were used to evaluate multivariate-adjusted associations between EBM educational intervention and EBM knowledge, attitude and skills. A new indicator of number needed to intervention (NNI) was defined and computed. Results: The results proved conference along with small-group discussion to be a more effective teaching method with P=0.001 on knowledge, P<0.001 for attitude and skills P<0.001 in an EBM exam when compared with medical faculty members who did not participate in EBM educational intervention (n=84). Moreover, they had also increased confidence with critical appraisal skills, and searching EBM resources. Conclusions: Conferences followed by small-group discussions significantly enhance EBM knowledge, attitude, critical appraisal skills and literature review skills.     

The effect of aerobic exercises among women with mild and moderate irritable bowel syndrome: A pilot study

Background

Irritable Bowel Syndrome (IBS) is a functional bowel disorder characterized by abdominal pain or discomfort. Although patients with IBS are commonly recommended to increase their physical activity, after reviewing the literature, it was found that no study has assessed the effect of aerobic exercises on the severity of symptoms and quality of life in patients with IBS. Therefore the aim of the present study was to evaluate the effect of aerobic exercises with treadmill on the severity of symptoms and quality of life among women with mild and moderate IBS.

Release modeling and comparison of nanoarchaeosomal,nanoliposomal and pegylated nanoliposomal carriers for paclitaxel

Breast cancer is the most prevalent cancer among women. Recently, delivering by nanocarriers has resulted in a remarkable evolution in treatment of numerous cancers. Lipid nanocarriers are important ones while liposomes and archaeosomes are common lipid nanocarriers. In this work, paclitaxel was used and characterized in nanoliposomal and nanoarchaeosomal form to improve efficiency. To increase stability, efficiency and solubility, polyethylene glycol 2000 (PEG 2000) was added to some samples. MTT assay confirmed effectiveness of nanocarriers on MCF-7 cell line and size measuring validated nano-scale of particles. Nanoarchaeosomal carriers demonstrated highest encapsulation efficiency and lowest release rate. On the other hand, pegylated nanoliposomal carrier showed higher loading efficiency and less release compared with nanoliposomal carrier which verifies effect of PEG on improvement of stability and efficiency. Additionally, release pattern was modeled using artificial neural network (ANN) and genetic algorithm (GA). Using ANN modeling for release prediction, resulted in R values of 0.976, 0.989 and 0.999 for nanoliposomal, pegylated nanoliposomal and nanoarchaeosomal paclitaxel and GA modeling led to values of 0.954, 0.951 and 0.976, respectively. ANN modeling was more successful in predicting release compared with the GA strategy.