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.     

Morphologically cryptic biological species within the liverwort Frullania asagrayana

? Premise of the study: The Frullania tamarisci complex includes eight Holarctic liverwort species. One of these, F. asagrayana, is distributed broadly throughout eastern North America from Canada to the Gulf Coast. Preliminary genetic data suggested that the species includes two groups of populations. This study was designed to test whether the two groups are reproductively isolated biological species. ? Methods: Eighty-eight samples from across the range of F. asagrayana, plus 73 samples from one population, were genotyped for 13 microsatellite loci. Sequences for two plastid loci and nrITS were obtained from 13 accessions. Genetic data were analyzed using coalescent models and Bayesian inference. ? Key results: Frullania asagrayana is sequence-invariant at the two plastid loci and ITS2, but two clear groups were resolved by microsatellites. The two groups are largely reproductively isolated, but there is a low level of gene flow from the southern to the northern group. No gene flow was detected in the other direction. A local population was heterogeneous but displayed strong genetic structure. ? Conclusions: The genetic structure of F. asagrayana in eastern North America reflects morphologically cryptic differentiation between reproductively isolated groups of populations, near-panmixis within groups, and clonal propagation at local scales. Reproductive isolation between groups that are invariant at the level of nucleotide sequences shows that caution must be exercised in making taxonomic and evolutionary inferences from reciprocal monophyly (or lack thereof) between putative species.     

What determines the number of ovarioles in a fly ovary?

The relation between the size of a fly and the number of ovarioles in its ovary was investigated in Phormia regina and Sarcophaga bullata. Small flies of varying size were produced by taking larvae prematurely off the food. The smallest flies thus obtained were derived from larvae only $\text{1}\text{8}$ of the weight of a normal larva. The number of ovarioles in an ovary is directly proportional to the size of the fly and, in the extreme case, is about $\text{1}\text{5}$ the normal number in Sarcophaga and about $\text{1}\text{3}$ in Phormia. Larvae prematurely taken off the food, but fed again after starving for several days, grow to normal or almost normal size and develop ovaries with about the normal number of ovarioles. Small or re-fed Sarcophaga do not show any changes in the anatomy of individual ovarioles but in Phormia disorders in ovariole development and a consequent reduction of fertility are frequent. The number of ovarioles remains identical from the early pupal stage all through the development of the pharate fly and then through ovarian development in the adult fly: it is determined by the size of the larva when it was taken off the food. This shows that it is not lack of space in a small adult fly abdomen which determines the number nor the occurrence of degenerative processes during ovarian development.     

Our experience with surgical treatment of primary cancer of the gallbladder

Witkin 1980-1988, 42 patients (4 males and 38 females) were operated for the gall-bladder cancer; it makes 2.9% of the patients who underwent cholecystectomies. Average age of female patients was 65 and males--71 years. No typical complaints were revealed making possible an early diagnosing of the gall-bladder cancer. The far advanced stages of this cancer were found in 41 cases. In i case no macroscopic features of the cancer were found. Cancer was diagnosed by means of histopathological examination. One patient (woman) survived more than 3 years after operation; 3 women survived more than 1 year. Average survival is 4 months.     

Kinetic constant variability in bacterial oxidation of elemental sulfur

Wide ranges of growth yields on sulfur (from 2.4 x 10(10) to 8.1 x 10(11) cells g(-1)) and maximum sulfur oxidation rates (from 0.068 to 1.30 mmol liter(-1) h(-1)) of an Acidithiobacillus ferrooxidans strain (CCM 4253) were observed in 73 batch cultures. No significant correlation between the constants was observed. Changes of the Michaelis constant for sulfur (from 0.46 to 15.5 mM) in resting cells were also noted.     

Effects of environmental air pollution on endogenous oxidative DNA damage in humans

Epidemiological studies conducted in metropolitan areas have demonstrated that exposure to environmental air pollution is associated with increases in mortality. Carcinogenic polycyclic aromatic hydrocarbons (c-PAHs) are the major source of genotoxic activities of organic mixtures associated with respirable particulate matter, which is a constituent of environmental air pollution. In this study,we wanted to evaluate the relationship between exposure to these genotoxic compounds present in the air and endogenous oxidative DNA damage in three different human populations exposed to varying levels of environmental air pollution. As measures of oxidative DNA damage we have determined 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodG) by liquid chromatography–tandem mass spectrometry (LC–MS/MS) and cyclic pyrimidopurinone N-1,N² malondialdehyde-2′-deoxyguanosine (M₁dG) by the immunoslot blot assay from lymphocyte DNA of participating individuals. The level of endogenous oxidative DNA damage was significantly increased in individuals exposed to environmental air pollution compared to unexposed individuals from Kosice (8-oxodG adducts) and Sofia (M₁dG adducts). However, there was no significant difference in the level of endogenous oxidative DNA and exposure to environmental air pollution in individuals from Prague (8-oxodG and M₁dG adducts) and Kosice (M₁dG adducts). The average level of M₁dG adducts was significantly lower in unexposed and exposed individuals from Kosice compared to those from Prague and Sofia. The average level of 8-oxodG adducts was significantly higher in unexposed and exposed individuals from Kosice compared to those from Prague. A significant increasing trend according to the interaction of c-PAHs exposure and smoking status was observed in levels of 8-oxodG adducts in individuals from Kosice. However, no other relationship was observed for M₁dG and 8-oxodG adduct levels with regard to the smoking status and c-PAH exposure status of the individuals. The conclusion that can be made from this study is that environmental air pollution may alter the endogenous oxidative DNA damage levels in humans but the effect appears to be related to the country where the individuals reside. Genetic polymorphisms of the genes involved in metabolism and detoxification and also differences in the DNA repair capacity and antioxidant status of the individuals could be possible explanations for the variation observed in the level of endogenous oxidative DNA damage for the different populations.     

Sequence and length recognition of the C-terminal turnover element of LpxC, a soluble substrate of the membrane-bound FtsH protease

The membrane-anchored FtsH protease is essential in Escherichia coli as it adjusts the cellular amount of LpxC, the key enzyme in lipopolysaccharide (LPS) biosynthesis. Both accumulation and depletion of LpxC are toxic to E. coli. By continuous proteolysis of LpxC, FtsH maintains a low concentration of LpxC and, hence, the proper equilibrium between LPS and phospholipids. The C terminus of LpxC is required for turnover. By adding this tail to glutathione-S-transferase (GST) we show that it is necessary but not sufficient for FtsH-mediated degradation. A detailed mutational analysis revealed six non-polar residues in the C terminus of LpxC that are critical for degradation. Alteration of the C-terminal AVLA motif towards the SsrA-like sequence ALAA directed LpxC to other cellular proteases reinforcing the importance of the C-terminal tail for targeting to FtsH. Short C-terminal truncations stabilized LpxC. Most mutations in the C terminus of LpxC left its enzymatic activity intact as was shown by growth assays, microscopy and 2-keto-3-deoxyoctonate (KDO) determination. The critical length of the turnover element was defined by internal deletions. A C-terminal tail of about 20 amino acids length is required for proteolysis of LpxC by FtsH.     

Analyses of volatiles produced by the African fruit fly species complex (Diptera,Tephritidae)

Ceratitis fasciventris, Ceratitis anonae and Ceratitis rosa are polyphagous agricultural pests originating from the African continent. The taxonomy of this group (the so-called Ceratitis FAR complex) is unclear. To clarify the taxonomic relationships, male and female-produced volatiles presumably involved in pre-mating communication were studied using comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (GC×GC-TOFMS) followed by multivariate analysis, and gas chromatography combined with electroantennographic detection (GC-EAD). GC×GC-TOFMS analyses revealed sex specific differences in produced volatiles. Male volatiles are complex mixtures that differ both qualitatively and quantitatively but share some common compounds. GC-EAD analyses of male volatiles revealed that the antennal sensitivities of females significantly differ in the studied species. No female volatiles elicited antennal responses in males. The results show clear species-specific differences in volatile production and provide complementary information for the distinct delimitation of the putative species by chemotaxonomic markers.     

Dioecious <Emphasis Type="Italic">Clusia nemorosa</Emphasis> achieves pollination by combining specialized and generalized floral rewards

Plants often combine multiple strategies to achieve pollen transfer. The dioecious Clusia nemorosa (Clusiaceae) produces floral resin, a specialized reward for resin-collecting bees. It also exhibits floral automimicry with female flowers mimicking male flowers in order to attract pollen-collecting insects. We observed the hourly visitation frequency and behaviour of bee visitors on two rock savanna sites in French Guiana. The major strategy in pollen transfer and the variation in visitation rates among visitor species were examined. We hypothesized that the visitation rate will vary between the floral sexes and degree of this variation will differ between the two-reward systems. We found no evidence for visits being exclusively related to resin collection, which we expected to be the principal strategy in pollen transfer. Deceit pollination appeared to have minor importance and seemed to be locally associated with the site, where demand for pollen was greater. Flower visits that probably facilitated most pollen transfer, combined resin and pollen. The pollinators involved in this system collected pollen from male flowers and resin from female flowers. The fruit set was not particularly low (44.19%) so offering different rewards by different flower genders has not constrained reproductive success in this system. Pronounced variation in visitation rates between sexes was not related to the pollination mechanisms but to the demand for the two rewards. Overall demand for pollen was greater than demand for resin. Female flowers were visited much less frequently than male flowers. Peak pollen collection occurred in the morning, i.e., as soon as the resource was available, while resin was collected throughout the day. There was a local variability in demand for the two resources because both the visitation rate and the behaviour of foraging bees varied between the two observation sites.