Lanthanide complexes of phthalimide and phthalamate containing ligands: synthesis, photophysical properties and their potential applications

Molecular sensors and switches have made important contributions to biomedical devices and molecular computational operations. There are numerous molecular designs using a fluorophore linked through a spacer group to a receptor(s), with a wide dynamic range, directional precision, target specificity, and molecular logic capability. Tb(IlI) and Eu(IIl) metal ions have natural luminescence lifetimes in the order of milliseconds. As a result they have been used as probes that allow discrimination between probe emission and background fluorescence using timeresolved techniques. Unfortunately the free ions themselves absorb light poorly so cannot provide the sensitivity often required of a probe or a sensor. Their performance however can be improved dramatically by the coordination of the metal ions to organic chelate ligands containing appropriate organic fluorophores. This project is based on the design and synthesis of Tb(lII) and Eu(lll) complexes of phthalimide and phthalamate derivatives as responsive lanthanide complexes

Impact of dietary aflatoxin on immune development in Gambian infants: a cohort study.

BACKGROUND: Chronic aflatoxin (AF) exposure has been shown to occur at high levels in children from sub-Saharan Africa (SSA), and has been associated with growth retardation and immune dysfunction. Our objective was to investigate the impact of AF exposure on immune development in early infancy using thymic size and antibody (Ab) response to vaccination as indicators of immune function. METHODS: A total of 374 infants born between May 2011 and December 2012 were enrolled into the current study. These infants were recruited from a larger, randomised trial examining the impact of nutritional supplementation of mothers and infants on infant immune development (the Early Nutrition and Immune Development Trial). Thymic size (Thymic Index, TI) was measured by sonography at 1 week, 8 weeks, 24 weeks and 52 weeks of infant age. Infants were given the diphtheria-tetanus-pertussis (DTP) vaccine at 8 weeks, 12 weeks and 16 weeks of age, and Ab responses to each vaccine measured at 12 weeks and 24 weeks of age. AF-albumin (AF-alb) adduct levels in infant blood were measured by ELISA as the biomarker of AF exposure. RESULTS: The geometric mean (GM) level of AF-alb increased with age. Only half of infants had detectable AF-alb with a GM of 3.52 pg/mg at 24 weeks, increasing to 25.39 pg/mg at 52 weeks, when 98% of infants had AF-alb >limit of detection. Significant negative association of AF-alb level with TI was seen in infants during the first 24 weeks, especially at 8 weeks of age (p<0.001), which is the time point of fastest thymus growth. There were no associations between AF exposure level and Ab response to pertussis and tetanus, but a significant positive correlation was observed between AF-alb level and Ab titre to diphtheria (p<0.005). CONCLUSIONS: High levels of AF exposure during early infancy may impact on infant immune development. TRIAL REGISTRATION NUMBER: ISRCTN49285450

Comparison of urinary aflatoxin M1 and aflatoxin albumin adducts as biomarkers for assessing aflatoxin exposure in Tanzanian children

Purpose: To determine levels of urinary aflatoxin M1 (AFM1) in children and correlate the concentrations with previously reported aflatoxin albumin adduct (AF-alb) levels in these children. Materials and methods: Matched urine and blood samples were collected from 84 Tanzanian children aged 6–14 months old. From 31 children in one village (Kigwa), samples were collected at three time points six months apart. Samples were collected from 31 and 22 children from two different regions at the second time point only. Urinary AFM1 was measured using a commercial enzyme-linked immunosorbent assay (ELISA) kit with a modified protocol to improve sensitivity. AF-alb was measured using an established ELISA method. Results: The relative ranking of the three villages for exposure to aflatoxin based on either AFM1 or AF-alb biomarker measurements was the same. In Kigwa village, both AFM1 and AF-alb levels were higher at six months post-harvest compared to baseline. However, at the next visit, the AFM1 levels dropped from a GM (interquartile range) of 71.0 (44.7, 112.6) at visit two to 49.3 (31.5, 77.3) pg/ml urine, whereas AF-alb levels increased from 47.3 (29.7, 75.2) to 52.7 (35.4, 78.3) pg/mg albumin between these two visits, reflecting the fact that AFM1 measures short-term exposure, whereas AF-alb measures longer term exposure. There was a correlation between AFB1 intake and AFM1 excretion (r= 0.442, p ≤ 0.001). Conclusions: Urinary AFM1 is a good biomarker for AFB1 exposure in Tanzanian children, reflecting geographical and temporal variations in exposure to this foodborne toxin

Impaired growth in rural Gambian infants exposed to aflatoxin: a prospective cohort study

Background: Exposure to aflatoxin, a mycotoxin produced by fungi that commonly contaminates cereal crops across sub-Saharan Africa, has been associated with impaired child growth. We investigated the impact of aflatoxin exposure on the growth of Gambian infants from birth to two years of age, and the impact on insulin-like growth factor (IGF)-axis proteins. Methods: A subsample (N = 374) of infants from the Early Nutrition and Immune Development (ENID) trial (ISRCTN49285450) were included in this study. Aflatoxin-albumin adducts (AF-alb) were measured in blood collected from infants at 6, 12 and 18 months of age. IGF-1 and IGFBP-3 were measured in blood collected at 12 and 18 months. Anthropometric measurements taken at 6, 12, 18 and 24 months of age were converted to z-scores against the WHO reference. The relationship between aflatoxin exposure and growth was analysed using multi-level modelling. Results: Inverse relationships were observed between lnAF-alb and length-for-age (LAZ), weight-for-age (WAZ), and weight-for-length (WLZ) z-scores from 6 to 18 months of age (β = − 0·04, P = 0·015; β = − 0·05, P = 0.003; β = − 0·06, P = 0·007; respectively). There was an inverse relationship between lnAF-alb at 6 months and change in WLZ between 6 and 12 months (β = − 0·01; P = 0·013). LnAF-alb at 12 months was associated with changes in LAZ and infant length between 12 and 18 months of age (β = − 0·01, P = 0·003; β = − 0·003, P = 0·02; respectively). LnAF-alb at 6 months was associated with IGFBP-3 at 12 months (r = − 0·12; P = 0·043). Conclusions: This study found a small but significant effect of aflatoxin exposure on the growth of Gambian infants. This relationship is not apparently explained by aflatoxin induced changes in the IGF-axis

High-resolution daily precipitation estimation data derived from Wuhan University Satellite and Gauge precipitation Collaborated Correction method (WHU-SGCC) in TIFF format

A daily precipitation estimation derived from WHU-SGCC method blending daily precipitation gauge data, gridded precipitation data and the Climate Hazards Group Infrared Precipitation (CHIRP, daily, 0.05°) satellite-derived precipitation estimates over Jinsha River Basin in summer 2016