Metformin treatment prevents gallstone formation but mimics porcelain gallbladder in C57Bl/6 mice.

Gallstone disease (GD) is highly correlated with metabolic syndrome and its related illnesses including type II diabetes (DMII) and polycystic ovary syndrome (PCOS). While previous studies claimed that metformin decreases the chance of developing GD in PCOS patients, this phenomenon has not been investigated in animal models to date. Here we fed a high fat diet (HFD) containing 2% of cholesterol and 1% of cholic acid to ten-week-old male C57Bl/6 mice for 105 days. The groups were as follows: Low fat diet; HFD; HFD + Ursodeoxycholic acid (UDCA) (day 1-105); HFD + Metformin (day 1-105); HFD + Metformin (Met) (day 64-105). All drugs were administered by oral gavage (Met = 300 mg/kg & UDCA = 750 mg/kg). Serum lipid profile and gross organ examination were performed after euthanasia. A microscopic evaluation of the paraffin-embedded gallbladders was done after hematoxylin & eosin and Von Kossa staining. HFD successfully induces gallstone (4 out of 4 of the HFD members). While both UDCA and metformin (d 1-105) prevented gallstone formation and cholecystitis, Metformin (d 64-105) group had a few small stones. Additionally, metformin induces mucosal calcification in gallbladder (porcelain GB) of more than 80% of the HFD + Met (day 1-105) and HFD + Met (day 64-105) groups, collectively, which can be a potential problem by itself. While metformin shows a noticeable benefit towards GB health by reducing the chance for gallstone formation, if it induces porcelain gallbladder in humans as well, it might inflict patients with preventable medical charges.

Increasing thermal stability and catalytic activity of glutamate decarboxylase in E. coli: An in silico study.

Glutamate decarboxylase (GAD) is an enzyme that converts l-glutamate to gamma amino butyric acid (GABA) that is a widely used drug to treat mental disorders like Alzheimer's disease. In this study for the first time point mutation was performed virtually in the active site of the E. coli GAD in order to increase thermal stability and catalytic activity of the enzyme. Energy minimization and addition of water box were performed using GROMACS 5.4.6 package. PoPMuSiC 2.1 web server was used to predict potential spots for point mutation and Modeller software was used to perform point mutation on three dimensional model. Molegro virtual docker software was used for cavity detection and stimulated docking study. Results indicate that performing mutation separately at positions 164, 302, 304, 393, 396, 398 and 410 increase binding affinity to substrate. The enzyme is predicted to be more thermo- stable in all 7 mutants based on ΔΔG value.

Sulfur Removal from Dibenzothiophene by Newly Isolated Paenibacillus validus Strain PD2 and Process Optimization in Aqueous and Biphasic (Model-Oil) Systems.

Dibenzothiophene (DBT) is an organic sulfur compound which remains in oil after hydrodesulfurization (HDS) process and can be removed by biodesulfurization (BDS). A new strain of Paenibacillus validus (strain PD2) was isolated from oil contaminated soils that is able to desulfurize DBT. HPLC analysis and Gibbs assay showed that this strain was capable to convert DBT to 2-Hydroxybiphenyl (2-HBP) as final product. The presence of dszC gene confirmed that DBT desulfurization occurred through the 4S pathway. Maximum growth and the highest induction in dsz operon obtained in the presence of dimethyl sulfoxide (DMSO) as sole sulfur source. DBT concentration, temperature and pH were optimized statistically for growing and resting cells by using Response Surface Methodology (RSM). All parameters in growing cells had a significant effect on 2-HBP production during BDS of DBT by P. validus PD2, although in resting cells temperature in range of 20-40 degrees C was not a significant factor. Maximum BDS for growing cells was obtained at 0.41 mM DBT concentration, pH 6.92 and temperature 31.23 degrees C. For resting cells, optimum pH, temperature and DBT concentration were 6.62, 27.73 degrees C and 7.86 mM respectively. The results of this study showed that high concentrations of DBT could be desulfurized by P. validus strain PD2 in model-oil. Thus, the isolated strain could be introduced as a proper candidate for biodesulfurization of organic sulfur in the oil industry.

Evaluation of Helicobacter pylori vacA genotypes in Iranian patients with peptic ulcer disease.

Helicobacter pylori is the major cause of active chronic gastritis and peptic ulcers in humans and has been linked to gastric carcinoma and lymphoma. The vacuolating cytotoxin vacA and cag pathogenicity island (cag PAI) are two identified virulence factors that are considered to have an important role in the pathogenesis of H. pylori infection. The aim of this study is to investigate the H. pylori vacA alleles in Iranian patients with peptic ulcer disease. In order to investigate this, biopsy specimens were obtained from 84 patients with gastric ulcer, gastritis, and duodenal ulcer. DNA extraction and PCR were used to detect the presence or absence of glmM, cagA and to assess the polymorphism of vacA. Of the 77 glmM PCR-positive biopsy specimens, 55 (71%) had the vacA signal sequence genotype s1, and 22 (29%) had subtype s2. vacA mid-region analysis revealed that 31 (40%) were vacA m1 and 46 (60%) were m2. The presence of the cagA gene correlated with vacA signal sequence type s1, whereas type s2 was predominantly found in cagA-negative samples (P < 0.001). Thus, the detection of vacA and cagA, virulence markers described in several clinical outcomes may be used to help the treatment and prevention of H. pylori in Iran.