777 research outputs found
Interleukin-1 polymorphisms associated with increased risk of gastric cancer
Helicobacter pylori infection is associated with a variety of clinical outcomes including gastric cancer and duodenal ulcer disease. The reasons for this variation are not clear, but the gastric physiological response is influenced by the severity and anatomical distribution of gastritis induced by H. pylori. Thus, individuals with gastritis predominantly localized to the antrum retain normal (or even high) acid secretion, whereas individuals with extensive corpus gastritis develop hypochlorhydria and gastric atrophy, which are presumptive precursors of gastric cancer. Here we report that interleukin-1 gene cluster polymorphisms suspected of enhancing production of interleukin-1-beta are associated with an increased risk of both hypochlorhydria induced by H. pylori and gastric cancer. Two of these polymorphism are in near-complete linkage disequilibrium and one is a TATA-box polymorphism that markedly affects DNA-protein interactions in vitro. The association with disease may be explained by the biological properties of interleukin-1-beta, which is an important pro-inflammatory cytokine and a powerful inhibitor of gastric acid secretion. Host genetic factors that affect interleukin-1-beta may determine why some individuals infected with H. pylori develop gastric cancer while others do no
Inter-hemispheric EEG coherence analysis in Parkinson's disease : Assessing brain activity during emotion processing
Parkinson’s disease (PD) is not only characterized by its prominent motor symptoms but also associated with disturbances in cognitive and emotional functioning. The objective of the present study was to investigate the influence of emotion processing on inter-hemispheric electroencephalography (EEG) coherence in PD. Multimodal emotional stimuli (happiness, sadness, fear, anger, surprise, and disgust) were presented to 20 PD patients and 30 age-, education level-, and gender-matched healthy controls (HC) while EEG was recorded. Inter-hemispheric coherence was computed from seven homologous EEG electrode pairs (AF3–AF4, F7–F8, F3–F4, FC5–FC6, T7–T8, P7–P8, and O1–O2) for delta, theta, alpha, beta, and gamma frequency bands. In addition, subjective ratings were obtained for a representative of emotional stimuli. Interhemispherically, PD patients showed significantly lower coherence in theta, alpha, beta, and gamma frequency bands than HC during emotion processing. No significant changes were found in the delta frequency band coherence. We also found that PD patients were more impaired in recognizing negative emotions (sadness, fear, anger, and disgust) than relatively positive emotions (happiness and surprise). Behaviorally, PD patients did not show impairment in emotion recognition as measured by subjective ratings. These findings suggest that PD patients may have an impairment of inter-hemispheric functional connectivity (i.e., a decline in cortical connectivity) during emotion processing. This study may increase the awareness of EEG emotional response studies in clinical practice to uncover potential neurophysiologic abnormalities
Circulating leukocyte telomere length is highly heritable among families of Arab descent
Background
Telomere length, an indicator of ageing and longevity, has been correlated with several biomarkers of cardiometabolic disease in both Arab children and adults. It is not known, however, whether or not telomere length is a highly conserved inheritable trait in this homogeneous cohort, where age-related diseases are highly prevalent. As such, the aim of this study was to address the inheritability of telomere length in Saudi families and the impact of cardiometabolic disease biomarkers on telomere length.
Methods
A total of 119 randomly selected Saudi families (123 adults and 131 children) were included in this cross-sectional study. Anthropometrics were obtained and fasting blood samples were taken for routine analyses of fasting glucose and lipid profile. Leukocyte telomere length was determined using quantitative real time PCR.
Results
Telomere length was highly heritable as assessed by a parent-offspring regression [h2 = 0.64 (p = 0.0006)]. Telomere length was modestly associated with BMI (R2 0.07; p-value 0.0087), total cholesterol (R2 0.08; p-value 0.0033), and LDL-cholesterol (R2 0.15; p-value 3 x 10-5) after adjustments for gender, age and age within generation.
Conclusion
The high heritability of telomere length in Arab families, and the associations of telomere length with various cardiometabolic parameters suggest heritable genetic fetal and/or epigenetic influences on the early predisposition of Arab children to age-related diseases and accelerated ageing
Microalbuminuria and glycated hemoglobin in children with type 1 diabetes mellitus
Diabetic nephropathy (DNP) is a microvascular complication that occurs in 20–40% of patients with type 1 diabetes (T1D). The main modifiable DNP initiation and progression factors in susceptible individuals may be sustained hyperglycemia and hypertension. The aim of the present work was to study glycemic control in children with T1D and the risk of microalbuminuria (MA) expressed as the urinary albumin/creatinine ratio (ACR).Subjects and methods: Forty children with T1D attending the diabetes clinic at the Alexandria University Children’s Hospital with a duration of diabetes of 3 years or more were included in the study and twenty apparently normal children were taken as controls. Clinical examination and blood pressure measurements were performed for all cases. Urine samples were collected within a 3–6 month period. The ACR in 2 of 3 specimens should be >30 mg/g before considering a patient to have microalbuminuria. HbA1c was measured and the mean of the last 4 readings was calculated.Results: 77.5% of patients had ACR >30 mg/g in two different samples. 88.8% of patients with poor glycemic control had MA compared to 53.8% with accepted glycemic control. The difference was more statistically significant among the adolescent age group (P = 0.001). MA was found in 77.2% of children with duration of T1D less than 5 years but the highest proportion was found when the disease duration was more than 10 years. There was no significant difference in systolic and diastolic blood pressure among diabetic children with and without MA (P = 0.556 and 0.781).Conclusion: Microalbuminuria in children with T1 DM is not limited to those with diseaseduration of 5 years or more and it may occur earlier. MA is significantly associated with poor glycemic control especially in adolescents. Other factors that may contribute to MA are not yet fully understood, further research is needed to clarify these factors
Supercritical carbondioxide extraction of cypermethrin in different fresh vegetables using anhydrous sodium sulfate for sample preparation and extraction
Supercritical fluid extraction (SFE) is a promising method of extraction for pesticide residues in fruits and vegetables. A rapid and high percetage of recoveries extraction of cypermethrin insecticides from fresh yardlong bean, carrot and eggplant vegetables matrixs using drying agent and SC-CO2 was developed in this study. In vegetable samples, which typically contain 80 - 95% water, but samples dry with Na2SO4 showed 96 - 105% recoveries in SFE. Moreover, the performance of drying agents (Na2SO4)and their combination such as Na2SO4 –H2O (6.7 + 1), Na2SO4 – H2O (2 + 1) and Na2SO4 – H2O (1 + 1) were evaluated. Na2SO4-H2O (1 + 1) was shown moisture conveyanced by SFE/mg highest (93) performance. Cypermethrin recovered from yardlong bean and carrot with critical pressure, PC at 20 Ibs and critical temperature, TC 40°C. On the other hand, the recovery rate of similar insecticides from egg plant was 96% with PC at 31.5 Ibs and 45°C in TC. The recovery rate in yardlong bean matrices was 100%; 105% was in carrot matrix. The retention time (tR) was 49.6 min of cypermethrin standard and similar tR was found in formulated. The lowest detectable limit (LDL) of cypermethrin insecticides was 0.02 ìg/mL with gas chromatography-electron capture detection (GC-ECD). GC-ECD temperature was of injection port and detector 280 and 300°C, respectively, with split less. However, the method is useful torecover non-polar insecticides from the fresh vegetable; thus, further research could be continued with co-solvents and different drying agents to recover the polar residues from different types of fresh vegetables
Impacts of organic and conventional crop management on diversity and activity of free-living nitrogen fixing bacteria and total bacteria are subsidiary to temporal effects
A three year field study (2007-2009) of the diversity and numbers of the total and metabolically active free-living diazotophic bacteria and total bacterial communities in organic and conventionally managed agricultural soil was conducted at the Nafferton Factorial Systems Comparison (NFSC) study, in northeast England. The result demonstrated that there was no consistent effect of either organic or conventional soil management across the three years on the diversity or quantity of either diazotrophic or total bacterial communities. However, ordination analyses carried out on data from each individual year showed that factors associated with the different fertility management measures including availability of nitrogen species, organic carbon and pH, did exert significant effects on the structure of both diazotrophic and total bacterial communities. It appeared that the dominant drivers of qualitative and quantitative changes in both communities were annual and seasonal effects. Moreover, regression analyses showed activity of both communities was significantly affected by soil temperature and climatic conditions. The diazotrophic community showed no significant change in diversity across the three years, however, the total bacterial community significantly increased in diversity year on year. Diversity was always greatest during March for both diazotrophic and total bacterial communities. Quantitative analyses using qPCR of each community indicated that metabolically active diazotrophs were highest in year 1 but the population significantly declined in year 2 before recovering somewhat in the final year. The total bacterial population in contrast increased significantly each year. Seasonal effects were less consistent in this quantitative study
<em>Enterococcus faecalis</em> Infection Causes Inflammation, Intracellular Oxphos-Independent ROS Production, and DNA Damage in Human Gastric Cancer Cells
Background: Achlorhydria caused by e.g. atrophic gastritis allows for bacterial overgrowth, which induces chronic inflammation and damage to the mucosal cells of infected individuals driving gastric malignancies and cancer. Enterococcus faecalis (E. faecalis) can colonize achlohydric stomachs and we therefore wanted to study the impact of E. faecalis infection on inflammatory response, reactive oxygen species (ROS) formation, mitochondrial respiration, and mitochondrial genetic stability in gastric mucosal cells. Methods: To separate the changes induced by bacteria from those of the inflammatory cells we established an in vitro E. faecalis infection model system using the gastric carcinoma cell line MKN74. Total ROS and superoxide was measured by fluorescence microscopy. Cellular oxygen consumption was characterized non-invasively using XF24 microplate based respirometry. Gene expression was examined by microarray, and response pathways were identified by Gene Set Analysis (GSA). Selected gene transcripts were verified by quantitative real-time polymerase chain reaction (qRT-PCR). Mitochondrial mutations were determined by sequencing. Results: Infection of MKN74 cells with E. faecalis induced intracellular ROS production through a pathway independent of oxidative phosphorylation (oxphos). Furthermore, E. faecalis infection induced mitochondrial DNA instability. Following infection, genes coding for inflammatory response proteins were transcriptionally up-regulated while DNA damage repair and cell cycle control genes were down-regulated. Cell growth slowed down when infected with viable E. faecalis and responded in a dose dependent manner to E. faecalis lysate. Conclusions: Infection by E. faecalis induced an oxphos-independent intracellular ROS response and damaged the mitochondrial genome in gastric cell culture. Finally the bacteria induced an NF-kappa B inflammatory response as well as impaired DNA damage response and cell cycle control gene expression
Effect of vitamin C on N,N′-dimethyl-4,4′-bipyridinium dichloride-induced hepatic and renal toxicity in Swiss albino mice
Purpose: To evaluate the effectiveness of vitamin C on paraquat-induced hepatic and renal toxicity in Swiss albino mice.Methods: Three groups of Swiss albino mice (n = 10), i.e., control, paraquat (15 mg/kg) and paraquat (15 mg/kg) + vitamin C (20 mg/kg) were used in the study. The drugs were administered intraperitoneally for four days. Blood samples were collected on day 5 for determination of serum levels of liver and renal biomarkers. Thereafter, the animals were sacrificed; liver and kidney were excised and preserved in neutral formalin for histopathological analysis.Results: The paraquat-treated animals showed higher levels of aspartate transaminase (AST), alanine transaminase (ALT), serum urea and creatinine, relative to values for control. Histopathological examination of the paraquat-treated animals showed cytoplasmic vacuolar degeneration and congestion of central vein in the liver, and glomerular necrosis in the kidneys. Control and vitamin C-treated mice showed normal architecture of liver and kidney.Conclusion: These results indicate that vitamin C modulated the paraquat-induced liver and renal abnormalities in the experimental animals. Thus vitamin C exerts hepatoprotective and renoprotective effects against paraquat poisoning.Keywords: Paraquat poisoning, Liver, Kidney, Vitamin C, Toxicity, Histopatholog
Antibacterial activity of extracts of marine algae from the Red Sea of Jeddah, Saudi Arabia
In the present study, marine algae were collected from the southern coast of Jeddah, Saudi Arabia during summer and autumn 2009. The antibacterial activities of petroleum ether, diethyl ether, ethyl acetate and methanol extracts of marine algae belonging to the Chlorophyta, Phaeophyta and Rhodophyta were studied. Their crude extracts were tested against different types of Gram-positive bacteria (Bacillus subtilis, Methicillin-Resistant Staphylococcus aureus (MRSA) and Staphylococcus aureu) and Gram-negative bacteria (Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa). All marine algae extracts tested exhibited a broad spectrum of antibacterial activity. The maximum inhibition activities were shown for extracts of Padina pavonica and Turbinaria triquetra. The growth inhibitions of bacteria by Sargassum portieriatum extracts were higher in samples collected during autumn than that investigated in summer. The maximum inhibitory effect of Gracilaria multipartita was observed in the petroleum ether extract against B. subtilis and E. coli. The ethyl acetate and petroleum ether extract of Enteromorpha prolifera and Ulva reticulata showed strong activity against the tested bacteria. The tested microorganisms that were susceptible to the most effective extracts were further tested for the minimum inhibitory concentration (MIC). The MIC of the tested microorganisms was between 0.5 and 1.25 µg/ml. The results of the present study confirmed the potential use of marine algae as a good source of antibacterial agent.Key words: Chlorophyta, Phaeophyta, Rhodphyta, gram-positive bacteria, gram-negative bacteria, solvent extract, minimum inhibitory concentration (MIC)
Plasmonic-enhanced photocatalysis reactions using gold nanostructured films
This work shows the enhancement of the visible photocatalytic activity of TiO2 NPs film using the localized surface plasmonic resonance of Au nanostructures. We adopted a simple yet effective surface treatment to tune the size distribution, and plasmonic resonance spectrum of Au nanostructured films on glass substrates, by hot plate annealing in air at low temperatures. A hybrid photocatalytic film of TiO2:Au is utilized to catalyse a selective photodegradation reaction of Methylene Blue in solution. Irradiation at the plasmonic resonance wavelength of the Au nanostructures provides more effective photodegradation compared to broadband artificial sunlight of significantly higher intensity. This improvement is attributed to the active contribution of the plasmonic hot electrons injected into the TiO2. The broadband source initiates competing photoreactions in the photocatalyst, so that carrier transfer from the catalyst surface to the solution is less efficient. The proposed hybrid photocatalyst can be integrated with a variety of device architectures and designs, which makes it highly attractive for low-cost photocatalysis applications
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