In vitro assessment of cytotoxicity of giomer on human gingival fibroblasts

Root coverage on restored root surfaces has been considered as a challenging issue. The evaluation of cytotoxic effects of restorative materials is a fundamental requirement for sustaining the cell attachment and the clinical success of root coverage. The aim of the present study was to compare the human gingival fibroblast cytotoxicity of the recently introduced giomer composite (GC) with resin ionomer (RI) restorative material. Discs (6x2 mm) of GC and RI restorative materials were prepared using sterile Teflon mold. Extracts from the materials were incubated to cell culture medium for 24, 48 and 72 h. Human gingival fibroblasts (HGF) were exposed to the extracts of the materials while the un-incubated media served as the control group. The cytotoxicity of the materials were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. In order to compare the mean values of the measured parameters a Kruskal-Walis test was carried out. MTT assay indicated that human gingival fibroblasts proliferated well in the presence of GC extract. The proliferation rate was higher in cells incubated with GC compared to RI extracts but the differences were not statistically significant (p= 0.09). This in vitro study indicated that GC is a non-toxic material for HGF. However, further studies are needed to assess the other biologic and clinical behavior of this material prior to it being considered as a potentially suitable restorative material to restore the carious root lesions candidated to root coverage procedures

Determination of cephalosporin acylase activity by biological and colorimetric method in bacteria

The effective production of 7-aminocephalosporanic acid (7-ACA) is a matter of concern in the pharmaceutical industry because it is a starting material for the synthesis of semi synthetic cephalosporin. Therefore screening for new source of cephalosporin acylase positive bacteria is veryimportant. The cephalosporin acylase can be found in several Pseudomonas sp. and other bacteria. To facilitate the attempts of obtaining the microorganisms with higher cephalosporin acylase activity from natural environments, development of new and specific methods for screening environmental microorganisms with cephalosporin acylase activity is very important. In this study, a biological and colorimetric method was evaluated for determination of cephalosporin acylase product in bacteria. Samples were cultured in general and selective media, and the routine biochemical laboratory tests were used for diagnosis of Pseudomonas sp. All of the isolated strains were tested for cephalosporinacylase by a biological and colorimetric method. A total of 180 Pseudomonas sp. out of 350 samples were isolated. Two strains capable of producing cephalosporin acylase were identified from 180 candidates. The Pseudomonas bacteria isolated in this study is a source for cloning and cephalosporin acylase enzyme production

Early age onset familial Mediterranean fever associated with compound heterozygote M680I /M694V mutation

Familial Mediterranean fever (FMF) is an autosomal recessive genetic disorder characterized by acute episodes of fever accompanied by severe abdominal pain, pleurisy, arthritis, and skin rash. The clinicalvariability of the disease has been mainly attributed to MEFV gene allelic heterogeneity and partly to the influence of additional genetic and/or environmental factors. We present a 6-month-old boy who suffered from recurrent fever accompanied by abdominal pain and skin rashes. Molecular screening by polymerase chain reaction (PCR) and sequencing for common mutations causing FMF revealed presence of a 694V/680I compound heterozygote mutation in exon 10 of the related gene. This is thefirst report of early onset and severe phenotype FMF case associated with a 694V/680I compound heterozygote mutation

Whole genome amplification: Use of advanced isothermal method

Laboratory method for amplifying genomic deoxyribonucleic acid (DNA) samples aiming to generate more amounts and sufficient quantity DNA for subsequent specific analysis is named whole genome amplification (WGA). This method is only way to increase input material from few cells and limited DNA contents. While PCR-based WGA methods have been under continuous development for over a decade, shortcomings of these methods enforced many researchers to switch to the use of non-PCR-based linear amplification techniques. Moreover, application of high fidelity and high possessive DNA polymerases enabled development of an isothermal WGA technique named multiple displacement amplification (MDA). MDA is not based on PCR and doses not require thermal cycling. It should be noted that, while MDA-based techniques proposed aiming to overcome the drawbacks of PCR-based methods however, MDA is still facing some challenges. It seems that PCR-based WGA methods alsohave some merits. One of the problems which encountered both MDA and PCR-based methods is in the amplification of degraded DNA templates. WGA methods such as T7-based linear amplification of DNA(TLAD), balanced-PCR amplification and restriction and circularization-aided rolling circle amplification (RCA-RCA) have been suggested to aim at amplification of such DNA templates.Keywords: Whole genome amplification, multiple displacement amplification (MDA), non PCR-based method

In vitro assessment of cytotoxicity of giomer on human gingival fibroblasts

Root coverage on restored root surfaces has been considered as a challenging issue. The evaluation of cytotoxic effects of restorative materials is a fundamental requirement for sustaining the cellattachment and the clinical success of root coverage. The aim of the present study was to compare the human gingival fibroblast cytotoxicity of the recently introduced giomer composite (GC) with resinionomer (RI) restorative material. Discs (6×2 mm) of GC and RI restorative materials were prepared using sterile Teflon mold. Extracts from the materials were incubated to cell culture medium for 24, 48and 72 h. Human gingival fibroblasts (HGF) were exposed to the extracts of the materials while the unincubated media served as the control group. The cytotoxicity of the materials were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. In order to compare the mean values of the measured parameters a Kruskal-Walis test was carried out. MTT assay indicated that human gingival fibroblasts proliferated well in the presence of GC extract. The proliferation rate washigher in cells incubated with GC compared to RI extracts but the differences were not statistically significant (p= 0.09). This in vitro study indicated that GC is a non-toxic material for HGF. However, further studies are needed to assess the other biologic and clinical behavior of this material prior to it being considered as a potentially suitable restorative material to restore the carious root lesions candidated to root coverage procedures

Molecular Epidemiology of Mycobacterium Tuberculosis Strains in the North‑West and West of Iran

Background: Identifying Mycobacterium tuberculosis (MTB) transmission type is a key step in the control of this disease. Aim: This study aimed to determine the path and transmission type of MTB and the insertion sequence IS6110 band number and verify their relationship to demographic and clinical risk factors. Subjects and Methods: In this cross‑sectional study, 64 MTB patients from three border provinces of Iran were selected after full clinical history and physical evaluation design. The drug susceptibility testing was carried out using the standard proportion technique on sputum samples. Isolates tested with restriction fragment length polymorphism technique used IS6110. Results: Recent transmission of disease was 33/50 (66%) based on clustering rate. The IS6110 band number had a significant relationship with drug resistance detected in proportion method tested by univariate linear regression (P < 0.01). Furthermore, the IS6110 band number had association with Bacillus Calmette–Guérin vaccination history (P = 0.02), sex (P < 0.01), and purified protein derivative (PPD) reaction size (P < 0.01) tested by multiple analysis. The risk of recent transmission inferred from the clustering rate was significantly higher in patients from Western provinces compared to those from the North‑West province (P = 0.048). However, age (P = 0.39), gender (P = 0.16), vaccination history (P = 0.57), drug susceptibility, and PPD (P = 0.6) were independent of clustering. The largest cluster of up to six subjects was found in the Western provinces.Conclusion: Recent MTB transmission was much more common in the West compared to the North‑West of Iran. Large MTB clusters with strong epidemiological links may be reflective of a disease outbreak. Correlation noted between the IS6110 band number and vaccination history; PPD size and female gender necessitates further studies.Keywords: Molecular epidemiology, Mycobacterium tuberculosis, Polymorphism, Restriction fragment lengt

Network Dynamics Mediate Circadian Clock Plasticity

A circadian clock governs most aspects of mammalian behavior. Although its properties are in part genetically determined, altered light-dark environment can change circadian period length through a mechanism requiring de novo DNA methylation. We show here that this mechanism is mediated not via cell-autonomous clock properties, but rather through altered networking within the suprachiasmatic nuclei (SCN), the circadian “master clock,” which is DNA methylated in region-specific manner. DNA methylation is necessary to temporally reorganize circadian phasing among SCN neurons, which in turn changes the period length of the network as a whole. Interruption of neural communication by inhibiting neuronal firing or by physical cutting suppresses both SCN reorganization and period changes. Mathematical modeling suggests, and experiments confirm, that this SCN reorganization depends upon GABAergic signaling. Our results therefore show that basic circadian clock properties are governed by dynamic interactions among SCN neurons, with neuroadaptations in network function driven by the environment

Phenotypic microarrays suggest Escherichia coli ST131 is not a metabolically distinct lineage of extra-intestinal pathogenic E. coli

Extraintestinal pathogenic E. coli (ExPEC) are the major aetiological agent of urinary tract infections (UTIs) in humans. The emergence of the CTX-M producing clone E. coli ST131 represents a major challenge to public health worldwide. A recent study on the metabolic potential of E. coli isolates demonstrated an association between the E. coli ST131 clone and enhanced utilisation of a panel of metabolic substrates. The studies presented here investigated the metabolic potential of ST131 and other major ExPEC ST isolates using 120 API test reagents and found that ST131 isolates demonstrated a lower metabolic activity for 5 of 120 biochemical tests in comparison to non-ST131 ExPEC isolates. Furthermore, comparative phenotypic microarray analysis showed a lack of specific metabolic profile for ST131 isolates countering the suggestion that these bacteria are metabolically fitter and therefore more successful human pathogens

Alterations in glutamatergic signaling contribute to the decline of circadian photoentrainment in aged mice

Robust physiological circadian rhythms form an integral part of well-being. The aging process has been found to negatively impact systems that drive circadian physiology, typically manifesting as symptoms associated with abnormal/disrupted sleeping patterns. Here, we investigated the age-related decline in light-driven circadian entrainment in male C57BL/6J mice. We compared light-driven resetting of circadian behavioral activity in young (1e2 months) and old (14e18 months) mice and explored alterations in the glutamatergic pathway at the level of the circadian pacemaker, the suprachiasmatic nucleus (SCN). Aged animals showed a significant reduction in sensitivity to behavioral phase resetting by light. We show that this change was through alterations in N-Methyl-D-aspartate (NMDA) signaling at the SCN, where NMDA, a glutamatergic agonist, was less potent in inducing clock resetting. Finally, we show that this shift in NMDA sensitivity was through the reduced SCN expression of this receptor’s NR2B subunit. Only in young animals did an NR2B antagonist attenuate behavioral resetting. These results can help target treatments that aim to improve both physiological and behavioral circadian entrainment in aged populations

Voluntary exercise can strengthen the circadian system in aged mice

Consistent daily rhythms are important to healthy aging according to studies linking disrupted circadian rhythms with negative health impacts. We studied the effects of age and exercise on baseline circadian rhythms and on the circadian system's ability to respond to the perturbation induced by an 8 h advance of the light:dark (LD) cycle as a test of the system's robustness. Mice (male, mPer2luc/C57BL/6) were studied at one of two ages: 3.5 months (n = 39) and >18 months (n = 72). We examined activity records of these mice under entrained and shifted conditions as well as mPER2::LUC measures ex vivo to assess circadian function in the suprachiasmatic nuclei (SCN) and important target organs. Age was associated with reduced running wheel use, fragmentation of activity, and slowed resetting in both behavioral and molecular measures. Furthermore, we observed that for aged mice, the presence of a running wheel altered the amplitude of the spontaneous firing rate rhythm in the SCN in vitro. Following a shift of the LD cycle, both young and aged mice showed a change in rhythmicity properties of the mPER2::LUC oscillation of the SCN in vitro, and aged mice exhibited longer lasting internal desynchrony. Access to a running wheel alleviated some age-related changes in the circadian system. In an additional experiment, we replicated the effect of the running wheel, comparing behavioral and in vitro results from aged mice housed with or without a running wheel (>21 months, n = 8 per group, all examined 4 days after the shift). The impact of voluntary exercise on circadian rhythm properties in an aged animal is a novel finding and has implications for the health of older people living with environmentally induced circadian disruption