Bioavailability and Concentration of Heavy Metals in the Sediments and Leaves of Grey Mangrove, <Emphasis Type="BoldItalic">Avicennia marina</Emphasis> (Forsk.) Vierh,in Sirik Azini Creek,Iran

The concentration and bioavailability of Ni, Cu, Cd, Zn, and Pb in the sediments and leaves of grey mangrove, Avicennia marina, were studied throughout Sirik Azini creek (Iran) with a view to determine heavy metals bioavailability, and two methods were used. Results show that Zn and Ni had the highest concentrations in the sediments, while Cd and Cu were found to have the lowest concentrations in the sediments. Compared to the mean concentrations of heavy metals in sedimentary rock (shales), Zn and Cu showed lower concentration, possibly indicating that the origin of these heavy metals is natural. A geo-accumulation index (I _geo) was used to determine the degree of contamination in the sediments. I _geo values for Zn, Cu, Pb, and Ni showed that there is no pollution from these metals in the study area. As heavy metal concentrations in leaves were higher than the bioavailable fraction of metals in sediments, it follows that bioconcentration factors (leaf/bioavailable sediment) for some metals were higher than 1.     

Comprehensive evaluation of one-carbon metabolism pathway gene variants and renal cell cancer risk

Introduction

Folate and one-carbon metabolism are linked to cancer risk through their integral role in DNA synthesis and methylation. Variation in one-carbon metabolism genes, particularly MTHFR, has been associated with risk of a number of cancers in epidemiologic studies, but little is known regarding renal cancer.

Methods

Tag single nucleotide polymorphisms (SNPs) selected to produce high genomic coverage of 13 gene regions of one-carbon metabolism (ALDH1L1, BHMT, CBS, FOLR1, MTHFR, MTR, MTRR, SHMT1, SLC19A1, TYMS) and the closely associated glutathione synthesis pathway (CTH, GGH, GSS) were genotyped for 777 renal cell carcinoma (RCC) cases and 1,035 controls in the Central and Eastern European Renal Cancer case-control study. Associations of individual SNPs (n = 163) with RCC risk were calculated using unconditional logistic regression adjusted for age, sex and study center. Minimum p-value permutation (Min-P) tests were used to identify gene regions associated with risk, and haplotypes were evaluated within these genes.

Results

The strongest associations with RCC risk were observed for SLC19A1 (P_min-P = 0.03) and MTHFR (P_min-P = 0.13). A haplotype consisting of four SNPs in SLC19A1 (rs12483553, rs2838950, rs2838951, and rs17004785) was associated with a 37% increased risk (p = 0.02), and exploratory stratified analysis suggested the association was only significant among those in the lowest tertile of vegetable intake.

Conclusions

To our knowledge, this is the first study to comprehensively examine variation in one-carbon metabolism genes in relation to RCC risk. We identified a novel association with SLC19A1, which is important for transport of folate into cells. Replication in other populations is required to confirm these findings.     

Results of skin test surveys for systemic Mycoses in Iran

Several investigators had carried out histoplasmin skin test surveys in 3 different areas of Iran before 1960 (5). To detect skin sensitivity to both histoplasmin and coccidioidin a study was carried out by the Institute of Public Health Research in parts of 7 of the country's 13 provinces on both apparently healthy persons and on clinic patients from February 1962–September 1966. These studies uncovered a small focus with a rather high level of positive reaction to histoplasmin (about 17 %). Positive cultures ofHistoplasma capsulatum were not obtained from either sputum of the positive reactors or from collected soils. In spite of a previously reported case of coccidioidomycosis, very low percentages of positive reaction to coccidioidin were noted.These studies were supported in part by the Institute of Public Health Research Teheran University, and funds of the Ministry of Health and Plan Organization for Project No. 631101 and N.I.H. Grant No. TW00170.Paper read at the Eighth International Congresses for Tropical Medicine and Malaria, September 1968, Teheran (Iran).     

The calcium-free form of atorvastatin inhibits amyloid-β(1–42) aggregation in vitro

Alzheimer''s disease is characterized by the presence of extraneuronal amyloid plaques composed of amyloid-beta (Aβ) fibrillar aggregates in the brains of patients. In mouse models, it has previously been shown that atorvastatin (Ator), a cholesterol-lowering drug, has some reducing effect on the production of cerebral Aβ. A meta-analysis on humans showed moderate effects in the short term but no improvement in the Alzheimer''s Disease Assessment Scale—Cognitive Subscale behavioral test. Here, we explore a potential direct effect of Ator on Aβ42 aggregation. Using NMR-based monomer consumption assays and CD spectroscopy, we observed a promoting effect of Ator in its original form (Ator-calcium) on Aβ42 aggregation, as expected because of the presence of calcium ions. The effect was reversed when applying a CaCO₃-based calcium ion scavenging method, which was validated by the aforementioned methods as well as thioflavin-T fluorescence assays and transmission electron microscopy. We found that the aggregation was inhibited significantly when the concentration of calcium-free Ator exceeded that of Aβ by at least a factor of 2. The ¹H–¹⁵N heteronuclear single quantum correlation and saturation-transfer difference NMR data suggest that calcium-free Ator exerts its effect through interaction with the ¹⁶KLVF¹⁹ binding site on the Aβ peptide via its aromatic rings as well as hydroxyl and methyl groups. On the other hand, molecular dynamics simulations confirmed that the increasing concentration of Ator is necessary for the inhibition of the conformational transition of Aβ from an α-helix-dominant to a β-sheet-dominant structure.     

Life-history variations of killifish (Aphanius sophiae) populations in two environmentally different habitats in central Iran

Two populations of Aphanius sophiae from two different habitats (one in a spring with stable environmental conditions and the other in a river with variable conditions) were examined to determine whether these conditions elicit differences in life history traits. Age composition revealed that females from the spring live longer. Von Bertalanffy growth parameters showed that L(∞) in the river population was higher than in the spring population. GSI showed a shorter reproduction period in A. sophiae from the river system. Egg diameter was significantly larger in the spring population. These results confirm the hypothesis of the response of killifish to local selective pressures in different habitats through adaptations via changes in the duration of the reproductive period, egg diameter, size changes, age composition and growth rate.     

Comprehensive analysis of 5-aminolevulinic acid dehydrogenase (ALAD) variants and renal cell carcinoma risk among individuals exposed to lead

Background

Epidemiologic studies are reporting associations between lead exposure and human cancers. A polymorphism in the 5-aminolevulinic acid dehydratase (ALAD) gene affects lead toxicokinetics and may modify the adverse effects of lead.

Methods

The objective of this study was to evaluate single-nucleotide polymorphisms (SNPs) tagging the ALAD region among renal cancer cases and controls to determine whether genetic variation alters the relationship between lead and renal cancer. Occupational exposure to lead and risk of cancer was examined in a case-control study of renal cell carcinoma (RCC). Comprehensive analysis of variation across the ALAD gene was assessed using a tagging SNP approach among 987 cases and 1298 controls. Occupational lead exposure was estimated using questionnaire-based exposure assessment and expert review. Odds ratios (OR) and 95% confidence intervals (CI) were calculated using logistic regression.

Results

The adjusted risk associated with the ALAD variant rs8177796^CT/TT was increased (OR = 1.35, 95%CI = 1.05–1.73, p-value = 0.02) when compared to the major allele, regardless of lead exposure. Joint effects of lead and ALAD rs2761016 suggest an increased RCC risk for the homozygous wild-type and heterozygous alleles (^GGOR = 2.68, 95%CI = 1.17–6.12, p = 0.01; ^GAOR = 1.79, 95%CI = 1.06–3.04 with an interaction approaching significance (p_int = 0.06).. No significant modification in RCC risk was observed for the functional variant rs1800435^(K68N). Haplotype analysis identified a region associated with risk supporting tagging SNP results.

Conclusion

A common genetic variation in ALAD may alter the risk of RCC overall, and among individuals occupationally exposed to lead. Further work in larger exposed populations is warranted to determine if ALAD modifies RCC risk associated with lead exposure.     

Effect of PGF2α and GnRH on the reproductive performance of postpartum dairy cows subjected to synchronization of ovulation and timed artificial insemination during the warm or cold periods of the year

This study was designed to evaluate the reproductive performance of lactating dairy cows (Holstein Friesian) after the injection of PGF_2α analogue on Day 15 postpartum, and GnRH analogue on Day 23 after artificial insemination (AI) with Presynch (two injections of PGF_2α, administered 14 days apart starting at 30–35 days postpartum) + Ovsynch-based (GnRH–7 days–PGF_2α–2 days–GnRH–16–20 hours–timed artificial insemination) treatments, during the warm and cold periods of the year. All the cows (n = 313) were assigned to one of the four groups including: M₁ (n = 72) in which the cows were treated with PGF_2α on Day 15 postpartum + Presynch-Ovsynch + GnRH on Day 23 post-AI; M₂ (n = 41) in which the cows received PGF_2α on Day 15 postpartum + Presynch-Ovsynch; M₃ (n = 100) including the cows that got Presynch-Ovsynch; and control group (n = 100) including the cows that were not treated and were inseminated at natural estrus. Pregnancy diagnosis was performed 28 to 35 days post-insemination by means of ultrasound. The results showed that treatment with PGF_2α on Day 15 postpartum significantly decreased the days to conception and the number of services per conception (P < 0.01) and it also improved the first service conception rate (P < 0.1) only in cows that were treated with M₂ protocol. Whereas, the days to first service was not influenced by the treatment of PGF_2α on Day 15 postpartum (P > 0.05). In contrast, administration of GnRH on Day 23 post-AI increased the days to conception and the number of service per conception (P < 0.01) and tended to decrease the first service conception rate (P < 0.1) in cows that were treated with M₁ compared with M₂ protocol. Therefore, it was concluded that Presynch-Ovsynch protocol could be more reproductive and beneficial when a single treatment with PGF_2α was administered at 15 days postpartum (15 days after the PGF_2α, Presynch-Ovsynch protocol was initiated). Interestingly, the administration of a GnRH agonist on Day 23 post-AI not only did not improve the reproductive performance of the cows receiving first postpartum timed artificial insemination after Presynch-Ovsynch protocol but also reduced that.