Hepatoprotective role and antioxidant capacity of selenium on arsenic-induced liver injury in rats

The present study was undertaken to evaluate the protective effect of selenium against arsenic-induced oxidative damage in experimental rats. Males were randomly divided into four groups where the first was served as a control, whereas the remaining groups were respectively treated with sodium selenite (3 mg/kg b.w.), sodium arsenite (5.55 mg/kg b.w.) and a combination of sodium arsenite and sodium selenite. Changes in liver enzyme activities, thiobarbituric acid reactive substances (TBARS) level, antioxidants and reduced glutathione (GSH) contents were determined after 3 weeks experimental period.Exposure of rats to As caused a significant increase in liver TBARS compared to control, but the co-administration of Se was effective in reducing its level. The activities of glutathione peroxidase (GPx) and glutathione-S-transferase (GST) of As-treated group were found lower compared to the control and the Se-treated group. The co-administration of Se had an additive protective effect on liver enzyme activities compared to As-treated animals. On the other hand, a significant increase in plasmatic activities of AST, ALT and ALP was observed in As-treated group. The latter was also exhibited a decrease in body weight and an increase in liver weight compared to the control. The co-administration of Se has decreased the activities of AST, AST and ALP and improved the antioxidant status as well. Liver histological studies have confirmed the changes observed in biochemical parameters and proved the beneficial role of Se. To conclude, results suggest that As exposure enhanced an oxidative stress by disturbing the tissue antioxidant defense system, but the Se co-administration protected liver tissues against As intoxication probably owing to its antioxidant properties.     

Bacterial Shedding in Household Contacts of Cholera Patients in Dhaka,Bangladesh

Multiple Vibrio cholerae infections within the same household are common. Household contacts of patients with cholera were observed with daily clinical assessments and collection of rectal swab cultures for nine days after presentation of the index case. During the follow-up period, 71 (24%) of 294 household contacts developed a positive V. cholerae rectal swab, signifying bacterial shedding. The average length of bacterial shedding was 2.0 days (95% confidence interval 1.7–2.4). However, 16 (5%) of 294 contacts shed V. cholerae for ≥ 4 days. In a multivariate analysis, malnutrition was predictive of long-term shedding (odds ratio = 1.4, 95% confidence interval = 1.3–13, P = 0.02). High rates of V. cholerae infection and bacterial shedding among household contacts of cholera patients represent an opportunity for intervention to reduce V. cholerae transmission.     

A highly sensitive and selective spectrofluorimetric method for the determination of cerium at pico-trace levels in some real,environmental, biological,soil, food and bone samples using 2-(α-pyridyl)-thioquinaldinamide

A very simple, ultra-sensitive and highly selective non-extractive new spectrofluorimetric method is presented for the determination of cerium at pico-trace levels using 2-(α-pyridyl)-thioquinaldinamide (PTQA). PTQA has been proposed as a new analytical reagent for the direct non-extractive spectrofluorimetric determination of cerium(iv). This novel fluorimetric reagent, PTQA becomes oxidized in a slightly acidic (0.0005–0.0015 M H₂SO₄) solution with cerium(iv) in absolute ethanol to produce a highly fluorescent oxidized product (λ_ex = 303 nm; λ_em = 370 nm). Constant and maximum fluorescence intensities were observed over a wide range of acidity (0.0005–0.0015 M H₂SO₄) for the period between 5 min and 24 h. Linear calibration graphs were obtained for 0.001–600 μg L⁻¹ of Ce, having a detection limit of 0.1 ng L⁻¹; the quantification limit of the reaction system was found to be 1 ng L⁻¹ and the RSD was 0–2%. A large excess of over 60 cations, anions and complexing agents (like, chloride, phosphate, azide, tartrate, oxalate, SCN⁻etc.) do not interfere in the determination. The developed method was successfully used in the determination of cerium in several certified reference materials (alloys, steels, noodles, ores and sediments) as well as in some environmental waters (potable and polluted), biological fluids (human blood, urine and milk), soil samples, food samples (vegetable, rice, corn and wheat), bone samples (human, cow, bull, fish, hen, goat, sheep), solutions containing both cerium(iii) and cerium(iv) and complex. The results of the proposed method for assessing biological, food and vegetables samples were comparable with ICP-OES and were found to be in excellent agreement.

A very simple, ultra-sensitive and highly selective non-extractive new spectrofluorimetric method is presented for the determination of cerium at pico-trace levels using 2-(α-pyridyl)-thioquinaldinamide (PTQA).     

Cancer recurrence after solid organ transplantation: A systematic review and meta-analysis

Solid organ transplant recipients (SOTR) with a pre-transplant malignancy (PTM) have been thought to be at high risk of cancer recurrence. However, recent population-based studies report cancer recurrence rates in SOTR similar to those of non-transplant patients. A systematic search was performed in MEDLINE, EMBASE, and Cochrane Library to identify studies reporting cancer recurrence in SOTR with PTM. Quality assessment was performed using a validated tool for assessing the quality of an observational study with no control group designed by the Institute of Health Economics. Overall and site-specific recurrence rates per person-year were pooled using generalized linear random/mixed-effects meta-analysis models and an exact likelihood approach based on a binomial and Poisson distribution. Meta-regressions, subgroup and sensitivity meta-analyses were used to explore sources of heterogeneity. Fifty-seven eligible studies were identified and 39 were included in the meta-analysis. The pooled recurrence rate was 1.6 (95% CI 1.0–2.6) per 100 person-year for all studies, and 1.1 (95% CI 0.5–2.7) when restricted to population-based studies. The recurrence rate was higher for kidney (2.4 per 100 person-year, 95% CI 1.0–5.6) compared with liver (1.0 per 100 person-year, 95% CI 0.4–2.6), and cardiothoracic recipients (1.3 per 100 person-year, 95% CI 0.6–2.7). Time from cancer diagnosis to transplantation (TCT) ≤ 5 years was associated with greater risk of cancer recurrence compared to TCT > 5 years (risk ratio: 2.80, 95% CI 1.12–7.01). In conclusion, the risk of cancer recurrence in recipients with PTM is considerably lower than historic reports used to establish recommendations for listing patients with PTM. Evidence to support minimum cancer remission times before transplantation is limited.     

Two new alkaloids of the crinane series from Pancratium sickenbergeri

Two new alkaloids; ent-6alpha/6beta-hydroxybuphanisine, (-)-8-demethylmaritidine and seven known alkaloids were isolated from Pancratium sickenbergeri grown in Egypt. Three of the known alkaloids were tested in the NCI cytotoxicity screen, but were found to be inactive.     

Immune responses to cholera in children

Cholera is a severe acute dehydrating diarrheal disease caused by Vibrio cholerae O1 or O139 infection, and is associated with significant mortality and morbidity globally. Although young children bear a high burden of the disease, currently available oral vaccines give a lower efficacy and shorter duration of protection in this group than in adults. According to the studies of natural infection, young children achieve comparable systemic anti-V. cholerae antigen-specific antibody, gut-homing antibody-secreting cell and memory B-cell responses as adults. Studies on innate and cell-mediated immune responses are lacking in children, and may offer important insights into differences in vaccine efficacy. The impact of host factors such as malnutrition, genetics and coinfection with other pathogens also remains to be fully defined.     

Molecular genetic maps in wild emmer wheat, Triticum dicoccoides: genome-wide coverage, massive negative interference, and putative quasi-linkage

The main objectives of the study reported here were to construct a molecular map of wild emmer wheat, Triticum dicoccoides, to characterize the marker-related anatomy of the genome, and to evaluate segregation and recombination patterns upon crossing T. dicoccoides with its domesticated descendant Triticum durum (cultivar Langdon). The total map length exceeded 3000 cM and possibly covered the entire tetraploid genome (AABB). Clusters of molecular markers were observed on most of the 14 chromosomes. AFLP (amplified fragment length polymorphism) markers manifested a random distribution among homologous groups, but not among genomes and chromosomes. Genetic differentiation between T. dicoccoides and T. durum was attributed mainly to the B genome as revealed by AFLP markers. The segregation-distorted markers were mainly clustered on 4A, 5A, and 5B chromosomes. Homeoalleles, differentially conferring the vigor of gametes, might be responsible for the distortion on 5A and 5B chromosomes. Quasilinkage, deviation from free recombination between markers of nonhomologous chromosomes, was discovered. Massive negative interference was observed in most of the chromosomes (an excess of double crossovers in adjacent intervals relative to the expected rates on the assumption of no interference). The general pattern of distribution of islands of negative interference included near-centromeric location, spanning the centromere, and median/subterminal location. [An appendix describing the molecular marker loci is available as an online supplement at http://www.genome.org.]