Lead concentration in the muscles of slaughtered buffalos in northwest regions of Iran

Background: The topic of food safety has become a major public health issue worldwide. Over recent decades, the growing concern for food safety has brought about greater research regarding the risks associated with the consumption of produce that has been contaminated by pesticides, heavy metals and/or toxins. Objective: The study was conducted to determine the concentration of Pb in the muscle of buffalos slaughtered in the northwest regions of Iran (Ardabil, Urmia and Tabriz cities). Methods: The present was a descriptive cross-sectional study in the northwest regions of Iran during 2013 to 2014. A total of 30 muscle samples from individual buffalos were analyzed for Pb concentrations using Atomic Absorption Spectrophotometer (ASS). Statistical analysis was performed using SPSS 17.0. All results were computed as mean standard deviation and subjected to one-way analysis of variance to establish whether the differences in Pb concentrations in meat samples from different cities were significant or not. The Statistical significance was determined at p<0.05. Results: The results showed that the mean concentration of Pb in muscle samples were measured 0.043±0.035 ppm. The highest Pb concentration (0.11 ppm) was detected in the buffalo muscle samples from Urmia city. In total, 25 muscle samples (80.33%) were contaminated with Pb and concentration of Pb in 3.33% of contaminated samples exceeded the permissible limits advised by the European Commission (EC) (0.1 ppm). Conclusion: We recommend identifying Pb sources in order to eliminate or control Pb contamination of food, and monitor environmental exposures and hazards to prevent lead poisoning

Investigating the unofficial factors in Google ranking

This paper evaluates the effectiveness of some “unofficial” factors in Search Engine Optimisation. A summary of official Google guidelines is given followed by a review of “unofficial” ranking factors as reported by a number of experts in the field of Search Engine Optimisation”. These opinions vary and do not always agree. Experiments on keyword density, web page titles and the use of outbound links were conducted to investigate the expert’s hypotheses by analysing Google result pages. The results demonstrate that webmasters should avoid having unnecessary outbound links, while attempting to repeat the important keywords of each page one time in their titles, to increase the pages ranking in the results page

Pulmonary function tests in ulcerative colitis

Background: Pulmonary impairment in patients suffering ulcerative colitis (UC) has been suggested by several investigators using standard pulmonary function tests (PFTs). This changes in pulmonary function associated with minimal respiratory symptoms have been documented, especially in patients with active disease. The aim of this prospective study was to determine airway resistance and lung volumes in patients with UC who have no respiratory symptoms in comparisons to a healthy control group. Materials and Methods: We evaluated a total of 30 patients with UC by means of spirometry, body plethysmography, and impulse oscillometry. The patients were not complaining of any pulmonary symptoms and did not present any history of previous respiratory diseases. As controls we examined 30 healthy subjects matched for gender, age, and smoking status. The relationship between PFT, lung volume, and airway resistance; and the activity, localization, and duration of the UC disease were analyzed. Results: There was a significant difference between airway resistances (kPa/L/s) measured by body plethysmography in patients with UC and those of the controls (R5hz; 0.60 +/- 0.44 vs. 0.39 +/- 0.13; P 0.05). Conclusion: Despite the lack of pulmonary symptoms, increased airway resistance was found in UC patients. We also have not found correlation between PFT, lung volume and airway resistance values and scoring of UC activity

Epidemiological features of irritable bowel syndrome and its subtypes among Iranian adults

Abstract Background The epidemiological features of irritable bowel syndrome (IBS) have not been properly investigated in Iran. Also, worldwide there is limited knowledge about the characteristics of IBS subtypes. The aim of the study was to explore the epidemiological features of IBS and its subtypes among Iranian adults

Role of life events in the presence of colon polyps among African Americans

African Americans have disproportionately higher incidence and death rates of colorectal cancer among all ethnic groups in the United States. Several lifestyle factors (e.g. diet, physical activity and alcohol intake) have been suggested as risk factors for colorectal cancer. Stressful life events have also been identified as risk factors for colorectal cancer. The association between stressful life events and colon polyps, which are precursors of colorectal cancer, has yet to be determined. We aimed to evaluate the relationship between stressful life events and the presence of colon polyps and adenomas in African American men and women. In this cross-sectional study, 110 participants were recruited from a colon cancer screening program at Howard University Hospital. Participants completed an 82-item Life Events Questionnaire (Norbeck 1984), assessing major events that have occurred in the participants’ life within the past 12 months. Participants also reported whether the event had a positive or negative impact. Three scores were derived (total, positive, and negative). Total life events scores were higher (Median [M] = 29 and Interquartile range [IQR] = 18-43) in patients with one or more polyps compared to patients without polyps (M, IQR = 21,13-38; P = 0.029). Total, positive or negative Life Events scores did not differ significantly between normal and adenoma patients. Total, negative and positive Life Events scores did not differ between patients who underwent diagnostic colonoscopy (symptomatic) and patients who underwent colonoscopy for colon cancer screening (asymptomatic) and patients for surveillance colonoscopies due to a personal history of colon polyps. Linear regression analysis indicated that male gender is associated with 9.0 unit lower total Life Events score (P = 0.025). This study suggests that patients who experienced total life events may be at higher risk of having colon polyps and adenomas which indicates an association between stress and the development of colorectal polyps.https://doi.org/10.1186/1471-230X-13-10

Rhodopsin-mediated nutrient uptake by cultivated photoheterotrophic Verrucomicrobiota

Rhodopsin photosystems convert light energy into electrochemical gradients used by the cell to produce ATP, or for other energy-demanding processes. While these photosystems are widespread in the ocean and have been identified in diverse microbial taxonomic groups, their physiological role in vivo has only been studied in few marine bacterial strains. Recent metagenomic studies revealed the presence of rhodopsin genes in the understudied Verrucomicrobiota phylum, yet their distribution within different Verrucomicrobiota lineages, their diversity, and function remain unknown. In this study, we show that more than 7% of Verrucomicrobiota genomes (n = 2916) harbor rhodopsins of different types. Furthermore, we describe the first two cultivated rhodopsin-containing strains, one harboring a proteorhodopsin gene and the other a xanthorhodopsin gene, allowing us to characterize their physiology under laboratory-controlled conditions. The strains were isolated in a previous study from the Eastern Mediterranean Sea and read mapping of 16S rRNA gene amplicons showed the highest abundances of these strains at the deep chlorophyll maximum (source of their inoculum) in winter and spring, with a substantial decrease in summer. Genomic analysis of the isolates suggests that motility and degradation of organic material, both energy demanding functions, may be supported by rhodopsin phototrophy in Verrucomicrobiota. Under culture conditions, we show that rhodopsin phototrophy occurs under carbon starvation, with light-mediated energy generation supporting sugar transport into the cells. Overall, this study suggests that photoheterotrophic Verrucomicrobiota may occupy an ecological niche where energy harvested from light enables bacterial motility toward organic matter and supports nutrient uptake.Funding for this project came from the Milgrom Foundation (to LS and OB) and from the United States National Science Foundation (NSF, OCE1924464 to L.G.-C) and the United States-Israel Binational Science Foundation (BSF, No. 2019612 to LS). We are very thankful to Prof. Aharon Oren for help with nomenclature.Peer reviewe

Widespread use of proton-pumping rhodopsin in Antarctic phytoplankton

Photosynthetic carbon (C) fixation by phytoplankton in the Southern Ocean (SO) plays a critical role in regulating air–sea exchange of carbon dioxide and thus global climate. In the SO, photosynthesis (PS) is often constrained by low iron, low temperatures, and low but highly variable light intensities. Recently, proton-pumping rhodopsins (PPRs) were identified in marine phytoplankton, providing an alternate iron-free, light-driven source of cellular energy. These proteins pump protons across cellular membranes through light absorption by the chromophore retinal, and the resulting pH energy gradient can then be used for active membrane transport or for synthesis of adenosine triphosphate. Here, we show that PPR is pervasive in Antarctic phytoplankton, especially in iron-limited regions. In a model SO diatom, we found that it was localized to the vacuolar membrane, making the vacuole a putative alternative phototrophic organelle for light-driven production of cellular energy. Unlike photosynthetic C fixation, which decreases substantially at colder temperatures, the proton transport activity of PPR was unaffected by decreasing temperature. Cellular PPR levels in cultured SO diatoms increased with decreasing iron concentrations and energy production from PPR photochemistry could substantially augment that of PS, especially under high light intensities, where PS is often photoinhibited. PPR gene expression and high retinal concentrations in phytoplankton in SO waters support its widespread use in polar environments. PPRs are an important adaptation of SO phytoplankton to growth and survival in their cold, iron-limited, and variable light environment.This work was funded by the NSF Grants OPP1745036 (to A.N.S. and A.M.), OPP1744760 (to B.M.H.), and PLR1440435 (to O.S.).Peer reviewe

A Case Based-Shared Teaching Approach in Undergraduate Medical Curriculum: A Way for Integration in Basic and Clinical Sciences

To present a multiple-instructor, active-learning strategy in the undergraduate medical curriculum. This educational research is a descriptive one. Shared teaching sessions, were designed for undergraduate medical students in six organ-system based courses. Sessions that involved in-class discussions of integrated clinical cases were designed implemented and moderated by at least 3 faculties (clinicians and basic scientists). The participants in this study include the basic sciences medical students of The Tehran University of Medical Sciences. Students’ reactions were assessed using an immediate post-session evaluation form on a 5-point Likert scale. Six two-hour sessions for 2 cohorts of students, 2013 and 2014 medical students during their two first years of study were implemented from April 2014 to March 2015. 17 faculty members participated in the program, 21 cases were designed, and participation average was 60 % at 6 sessions. Students were highly appreciative of this strategy. The majority of students in each course strongly agreed that this learning practice positively contributed to their learning (78%) and provided better understanding and application of the material learned in an integrated classroom course (74%). They believed that the sessions affected their view about medicine (73%), and should be continued in future courses (80%). The percentage demonstrates the average of all courses. The program helped the students learn how to apply basic sciences concepts to clinical medicine. Evaluation of the program indicated that students found the sessions beneficial to their learning