Iodine, Selenium, and Other Trace Elements in Urine of Pregnant Women

The purpose of this work was to determine trace element levels in urine and evaluate possible associations between urinary iodine concentration (UIC), other trace elements (Cr, Cu, Fe, Mn, Na, Se, Zn), toxic elements (Cd, Pb), anthropometrical measures (body weight and height), glycemic indices (serum insulin and glucose), and several parameters related to thyroid function (thyroid stimulating hormone, free thyroxine, antithyroid peroxidase antibodies, thyroid volume, and thyroid echogenicity) in pregnant women. One hundred sixty-nine participants were recruited. The whole study group, originating from Krakow region, comprised three subgroups belonging to three trimesters: I trimester (n?=?28), II trimester (n?=?83), and III trimester (n?=?58). Trace elements were determined using inductively coupled plasma mass/(atomic emission) spectrometry. Partial least square model was used to reveal correlation structure between parameters investigated, as well as a possible causal relationship between dependent parameters and potentially explanatory parameters. Results obtained for trace and toxic elements in urine were comparable with results of other authors, although the study group was not homogenous. We confirmed (1) low iodine excretion in pregnant women, (2) the existence of statistically significant correlation between UIC and urinary selenium, and (3) lack of correlation between latter parameter and typical indices of thyroid function. Urinary selenium correlated with other urinary trace elements, but physiological significance of this finding remains uncertain. The fact that a large number of pregnant women fail to meet dietary recommendations for iodine is the major reason for concern.     

Protective action of melatonin against oxidative DNA damage: chemical inactivation versus base-excision repair

Melatonin is a hormone-like substance that has a variety of beneficial properties as regulator of the circadian rhythm and as anti-inflammatory and anti-cancer agent. The latter activity can be linked with the ability of melatonin to protect DNA against oxidative damage. It may exert such action either by scavenging reactive oxygen species or their primary sources, or by stimulating the repair of oxidative damage in DNA. Since such type of DNA damage is reflected in oxidative base modifications that are primarily repaired by base-excision repair (BER), we tried to investigate in the present work whether melatonin could influence this DNA-repair system. We also investigated the ability of melatonin to inactivate hydrogen peroxide, a potent source of reactive oxygen species. Melatonin at 50 microM and its direct metabolite N(1)-acetyl-N(2)-formyl-5-methoxykynuramine reduced DNA damage induced by hydrogen peroxide at approximately the same ratio. Melatonin stimulated the repair of DNA damage induced by hydrogen peroxide, as assessed by the alkaline comet assay. However, melatonin at 50 microM had no impact on the activity in vitro of three glycosylases playing a pivotal role in BER: Endo III, Fpg and ANPG 80. On the other hand, melatonin chemically inactivated hydrogen peroxide, reducing its potential to damage DNA. And finally, melatonin did not influence the repair of an a-basic (AP) site by cellular extracts, as was evaluated by a functional BER assay in vitro. In conclusion, melatonin can have a protective effect against oxidative DNA damage by chemical inactivation of a DNA-damaging agent as well as by stimulating DNA repair, but key factors in BER, viz. glycosylases and AP-endonucleases, do not seem to be affected by melatonin. Further study with other components of the BER machinery and studies aimed at other DNA-repair systems are needed to clarify the mechanism underlying the stimulation of DNA repair by melatonin.     

Identification of a novel risk locus for progressive supranuclear palsy by a pooled genomewide scan of 500,288 single-nucleotide polymorphisms

To date, only the H1 MAPT haplotype has been consistently associated with risk of developing the neurodegenerative disease progressive supranuclear palsy (PSP). We hypothesized that additional genetic loci may be involved in conferring risk of PSP that could be identified through a pooling-based genomewide association study of >500,000 SNPs. Candidate SNPs with large differences in allelic frequency were identified by ranking all SNPs by their probe-intensity difference between cohorts. The MAPT H1 haplotype was strongly detected by this methodology, as was a second major locus on chromosome 11p12-p11 that showed evidence of association at allelic (P<.001), genotypic (P<.001), and haplotypic (P<.001) levels and was narrowed to a single haplotype block containing the DNA damage-binding protein 2 (DDB2) and lysosomal acid phosphatase 2 (ACP2) genes. Since DNA damage and lysosomal dysfunction have been implicated in aging and neurodegenerative processes, both genes are viable candidates for conferring risk of disease.     

Size variation in chewing lice <Emphasis Type="Italic">Docophorulus coarctatus</Emphasis>: how host size and louse population density vary together

Chewing lice of the species Docophorulus coarctatus were extracted from museum specimens of their host, the great grey shrike Lanius excubitor, by combing feathers from 36 freshly shot birds (shot between 1962 and 1974), and samples of ten individual lice (five female, five male) were randomly collected for measurements from each bird. Female lice were bigger than males for all studied measurements (P < 0.001 in all cases), although the size of both sexes obtained from individual hosts was positively correlated. The overall size of lice (derived from a principal components analysis) was positively correlated with the overall size of the avian host, and also with the population density of lice on the individual host. We suggest that variation in louse morphology is due to differences in selection pressure exerted by each host and by intraspecific competition due to conspecifics. This is, to the best of our knowledge, the first evidence that Harrison’s rule (parasites on larger host species are often bigger than those on smaller hosts) not only works in a multispecies comparison but also within a single host–single parasite system as well.     

The influence of bariatric surgery on calcium homeostasis and biochemical markers of bone turnover in patients with morbid obesity

INTRODUCTION: Obese patients may have abnormal calcium homeostasis because of unbalanced diet and decreased sun exposure. Bariatric surgery itself may lead to disturbances in calcium homeostasis (and in consequence changes in bone mass) or increase preexisting metabolic derangements. The aim of the study was: 1. To assess calcium homeostasis and biochemical markers of bone turnover in patients with morbid obesity. 2. To determine the impact of bariatric surgery on parameters mentioned above. 3. To establish recommendations for supplementation with calcium and vitamin D in morbidly obese patients after bariatric surgery. MATERIAL AND METHODS: Serum calcium, parathormone (PTH), vitamin D (25(OH)D), biochemical markers of bone turnover (beta-CrossLaps as a marker of bone resorption and osteocalcin as a marker of bone formation) and urine calcium as well as fat mass, lean mass and bone mineral content (by DXA) were measured before bariatric surgery of the stomach (VBG or GBP) in 57 morbidly obese patients (48 women, 9 men; mean age 35.9 y). The same procedures were repeated six months after operation in 28 of them (24 women, 4 men). Daily calcium intake was also determined based on food questionnaire. RESULTS: Biochemical findings in the group of patients before bariatric surgery were as follows: serum calcium, beta-CrossLaps and urine calcium were within normal range, PTH concentration was increased to 81.0 pg/ml and 25(OH)D as well as osteocalcin concentration decreased (4.9 ng/ml and 13.6 ng/ml, respectively). Six months after bariatric surgery there was no change in serum and urine calcium, PTH concentration decreased to normal level (46.8 pg/ml), 25(OH)D concentration increased to 6.5 ng/ml (not significant) and still remained below normal range. Markers of bone turnover--both resorption and formation--increased (beta-CrossLaps over normal range to 0.594 ng/ml, osteocalcin to normal range 26.8 ng/ml). Daily calcium intake was below RDA before and after bariatric procedure. CONCLUSIONS: 1. Patients with morbid obesity have secondary hyperparathyroidism and deficiency of vitamin D. 2. Abrupt weight loss after bariatric surgery is accompanied by the regression of secondary hyperparathyroidism, decrease of the deficiency of vitamin D and increase in bone turnover. 3. Supplementation with vitamin D and calcium is recommended for patients with morbid obesity after bariatric surgery.     

Lactones 26 : Stereoselective microbial epoxidation of unsaturated bicyclic γ-lactones with the alkylsubstituted cyclohexane system

The strain Absidia cylindrospora was chosen among eight fungal strains for the biotransformation of unsaturated lactones 1a–c. The processes were carried out by means of shaken cultures. The compounds 1a and 1b were efficiently converted into the corresponding trans-epoxylactones (2a and 2b), whereas the transformation of 1c gave the unsaturated hydroxylactone 3, with the tertiary hydroxy group introduced in the allylic position. The compound 2b was obtained with 100% ee. The structures of compounds 2a and 2b were fully confirmed by the X-ray analysis, which showed the half boat and half chair conformation of cyclohexane ring in these molecules, respectively. All the products were not reported previously in the literature.     

Affinity of dinucleotide cap analogues for human decapping scavenger (hDcpS)

Eukaryotic cells utilize scavenger decapping enzymes to degrade cap structure following 3'-5' mRNA decay. Human DcpS recently has been described as a highly specific hydrolase (a member of the HIT family) that catalyses the cleavage of m(7)GpppG and short capped oligoribonucleotides. We have demonstrated here that cap-1 (m(7)GpppGm) is a preferred substrate among several investigated dinucleotide cap analogues m(7)Gp(n)N (n = 3-5, N is a purine or pyrimidine base) and m(7)GMP is always one of the reaction product. Cap analogues containing pyrimidine base instead of guanine or diphosphate chain are resistant to hydrolysis catalyzed by human scavenger. Contrary to the other enzymes of HIT family, hDcpS activity is not stimulated by Mg(2+).     

A reversible decrease in ribulose 1,5‐bisphosphate carboxylase/oxygenase carboxylation activity caused by the aggregation of the enzyme's large subunit is triggered in response to the exposure of moderate irradiance‐grown plants to low irradiance

Ribulose‐1,5‐bisphosphate carboxylase/oxygenase (Rubisco) is highly regulated in response to fluctuations in the environment, including changes in irradiance. However, no complex data are available on Rubisco regulatory mechanisms triggered in plants which are submitted to moderate–low irradiance shift. Therefore, we investigated in a comprehensive way the changes at the level of amount of Rubisco protein, its structural organization and carboxylase activity of the holoenzyme as triggered by exposure of moderate irradiance‐grown Arabidopsis thaliana plants to low irradiance conditions. An exposure of moderate irradiance‐grown plants to low irradiance for a single photoperiod caused the exclusion of a certain pool of Rubisco under altered conditions owing to oxidative modifications resulting in the formation of protein aggregates involving Rubisco large subunit (LS). As a result, both initial and total Rubisco carboxylase activities were reduced, whereas Rubisco activation state remained largely unchanged. The results of the determination of reactive oxygen species indicated that a moderate/low irradiance transition had stimulated ¹O₂ accumulation and we strongly suggest that Rubisco oxidative modifications leading to formation of aggregates encompassing Rubisco‐LS were triggered by ¹O₂. When moderate irradiance regime was resumed, the majority of Rubisco‐LS containing aggregates tended to be resolubilized, and this allowed Rubisco carboxylation activities to be largely recovered, without changes in the activation state of the enzyme. In the longer term, these results allow us to better understand a complexity of Rubisco regulatory mechanisms activated in response to abiotic stresses and during recovery from the stresses.     

N‐terminal guanidinylation of the cyclic 1,4‐ureido‐deltorphin analogues: the synthesis,receptor binding studies,and resistance to proteolytic digestion

The synthesis of a series of N‐guanidinylated cyclic ureidopeptides, analogues of 1,4‐ureido‐deltorphin/dermorphine tetrapeptide is described. The δ‐ and μ‐opioid receptor affinity of new guanidinylated analogues and their non‐guanidinylated precursors was determined by the displacement radioligand binding experiments. Our results indicate that the guanidinylation of cyclic 1,4‐ureidodeltorphin peptide analogues does not exhibit a uniform influence on the opioid receptor binding properties, similarly as reported earlier for some linear peptides. All analogues were also tested for their in vitro resistance to proteolysis during incubation with large excess of chymotrypsin, pepsin, and papain by means of mass spectroscopy. Guanidinylated ureidopeptides 1G–4G showed mixed μ agonist/δ agonist properties and high enzymatic stability indicating their potential as therapeutic agents for treatment of pain. Copyright © 2015 European Peptide Society and John Wiley & Sons, Ltd.